CN106252220A

CN106252220A - Spectral signature is followed the trail of for the dynamic of end point determination or adaptability

Info

Publication number: CN106252220A
Application number: CN201610633597.2A
Authority: CN
Inventors: J·D·戴维; H·Q·李; T·C·利姆; G·K·H·拉姆
Original assignee: Applied Materials Inc
Current assignee: Applied Materials Inc
Priority date: 2010-05-05
Filing date: 2011-04-20
Publication date: 2016-12-21
Anticipated expiration: 2031-04-20
Also published as: CN102884613B; KR101774031B1; JP6316794B2; KR20170102068A; CN102884613A; JP2013526080A; WO2011139571A2; WO2011139571A3; TW201205703A; JP2016105486A; TWI467678B; CN106252220B; JP6039545B2; KR101907965B1; KR20130098172A

Abstract

Disclose and follow the trail of spectral signature for the dynamic of end point determination or adaptability.A kind of method controlling to grind comprises the following steps: grinding base plate；And receive the identification of selected spectral signature, have the wave-length coverage of width, and the characteristic of this selected spectral signature is to monitor during grinding.A series of spectrum of the light from this substrate are measured while grinding this substrate.A series of values of this characteristic of this selected spectral signature are produced according to this spectra.For at least some spectrum of this spectra, based on this spectral signature position in the previous wave-length coverage of the previous spectrum in this spectra, produce amendment wave-length coverage, in this amendment wave-length coverage, search this selected spectral signature, and determine the value of the characteristic of this selected spectral signature.

Description

Spectral signature is followed the trail of for the dynamic of end point determination or adaptability

The application is filing date on April 20th, 2011, Application No. " 201180022552.7 ", invention entitled " uses In end point determination dynamically or adaptability follows the trail of spectral signature " the divisional application of application for a patent for invention.

Technical field

This disclosure is about the Optical Monitoring carried out during the cmp of substrate.

Background technology

Generally by deposited in sequential conductive layer, semi-conductive layer or insulating barrier on Silicon Wafer, integrated circuit is formed at On substrate.One manufacturing step relates to deposit filler layer planarize this packing layer on a non-planar surface.Some is applied For, packing layer is planarized till the top surface of patterned layer exposes.For example, can be on patterned insulation layer Deposition conductive filler layer, to fill the groove in insulating barrier or hole.After planarization, between the raised design of insulating barrier Residue Conductive layer portions forms through hole, plug and wiring, and this through hole, plug and wiring provide between the thin flm circuit on substrate Conductive path.For other application (such as, oxide grinds (oxide polishing)), packing layer is planarized Till leaving predetermined thickness on a non-planar surface.It addition, photo-engraving process (photolithography) typically requires Substrate surface is planarized.

Cmp (Chemical mechanical polishing；CMP) it is a kind of acceptable planarization side Method.This flattening method typically requires and is installed on carrier head or grinding head by substrate.The surface that substrate exposes generally against Spin finishing pad and put.Carrier head provides controllable to load on substrate, with by substrate promote and against grinding pad.Generally Surface by abrasiveness slurry supply to grinding pad.

One of CMP have a problem in that determine grinding processing procedure whether complete (that is, substrate layer has been planarized to desired the most Flatness or thickness), or the most removed desired quantity of material.Slurry distribution, grinding pad condition, between grinding pad and substrate Relative velocity and substrate on the change of load, all can cause the change of material removal rate.These change and substrate layers The change of original depth, causes the change reaching the time required for grinding endpoint.Therefore, grinding endpoint can not only be defined as grinding The function of time consuming.

In some systems, (such as) via the in-situ monitoring base optically of the form in grinding pad during grinding Plate.But, existing optical surveillance technology and may be unsatisfactory for the needs of the increase of manufacturers of semiconductor devices.

Summary of the invention

Some optical endpoint detection system follow the trail of selected spectral signature characteristic in spectral measurement, to determine terminal or change Grinding rate.In spectrum, the spectral signature being similar to this selected spectral signature can make this selected spectral signature of tracking become tired Difficult.Identify that the wave-length coverage of this optical endpoint detection system, to search this selected spectral signature, can allow this optical end point to detect System correctly identifies this selected spectral signature, and uses the process resource reduced.

Grind in processing procedures at some, remove the second material (such as, nitride, such as, tantalum nitride or titanium nitride) from substrate The second layer (such as, barrier layer), include different the first material (such as, dielectric material, low dielectric radio materials to expose And/or low dielectric radio cover material) ground floor or Rotating fields.It is frequently desirable to remove this first material, until remaining target thickness Till.Selected spectral signature characteristic is followed the trail of, to determine terminal or to change some optical end points of grinding rate in spectral measurement Detection technique, grinds in processing procedure at this and can have problem, because the original depth of this second material is not known.But, Triggered by another surveillance technology (such as, motor torsional moment, eddy current or optical strength monitor) if spectral signature is followed the trail of, and another monitors Technology can reliably detect removing of this second material and exposing to the open air of lower floor or Rotating fields, then can avoid these problems.Additionally Between each substrate, the thickness of this layer or Rotating fields there may be change.For improving each base of the final thickness of this layer or Rotating fields Uniformity between plate, can measure this original depth of this layer or Rotating fields before the grinding, and can be thick from this original depth and target Degree calculates object feature value.

In an aspect, a kind of method controlling to grind comprises the following steps: grinding base plate；And receive selected spectrum The identification of feature, there is the wave-length coverage of width, and the characteristic of this selected spectral signature is to monitor during grinding.Grinding A series of spectrum of the light from this substrate are measured while grinding this substrate.This selected spectral signature is produced from this spectra A series of values of this characteristic.The step of this generation comprises the following steps: at least some spectrum from this spectra Speech, produces amendment wave-length coverage based on the position in this spectral signature previously wave-length coverage, searches in this amendment wave-length coverage Seeking this selected spectral signature, and determine the value of the characteristic of this selected spectral signature, this previous wave-length coverage is used for this spectra In previous spectrum.Grinding endpoint is determined or at least one in the adjustment of grinding rate based on this series of values.

Embodiment can include one or more following characteristics.This wave-length coverage can have fixed width.Produce this amendment wavelength The step of scope can comprise the steps of centered by this fixed width (centering) in this characteristic at this previous wavelength model On this position enclosed.Produce the step of this amendment wave-length coverage to can comprise the following steps that and determine that this characteristic is at this previous wavelength Position in scope and adjust this wave-length coverage so that in this amendment wave-length coverage, this characteristic is positioned to be closer to this and repaiies Change the center of wave-length coverage.The step producing this amendment wave-length coverage can comprise the following steps that in this spectra At least some spectrum, determines the wavelength value of this selected spectral signature, to produce a series of wavelength value；To this series of wavelengths value matching Function；And the expectancy wave long value of this selected spectral signature for subsequent optical spectrometry is calculated according to this function.This function can be Linear function.The step producing this amendment wave-length coverage can comprise the following steps that this width making this wave-length coverage is centered in On this expectancy wave long value.The method can comprise the following steps that to this series of values fitting function, and determines that grinding is eventually based on this function Put or at least one in the adjustment of grinding rate.Determine that the step of grinding endpoint can comprise the following steps that according to this letter Number calculates the initial values of these characteristics, calculates the currency of this characteristic according to this function, and calculate this initial value and this currency it Between difference, and when this difference reaches goal discrepancy interrupt grind.This function can be linear function.This selected spectral signature can comprise: Spectrum crest, spectrum trough or spectrum zero-crossing.This characteristic comprises the steps that wavelength, width or intensity.This selected spectral signature can be wrapped Containing spectrum crest, and this characteristic can comprise wave peak width.The spectrum of visible ray can be measured, and this wave-length coverage can have between 50 And the width between 200 nanometers.

In another aspect, a kind of method controlling to grind comprises the following steps: receives and selects making of fixed wave length scope User inputs, and this fixed wave length scope is the subset of the wavelength through in-situ monitoring systematic survey；Receive the knowledge of selected spectral signature Not and the characteristic of this selected spectral signature, to monitor during grinding；Grinding base plate；For each in this spectra Spectrum, measures a series of spectrum of the light from this substrate while grinding this substrate；This fixing ripple at this each spectrum Long scope searches this selected spectral signature, and determines the value of the characteristic of this selected spectral signature, to produce a series of value；And At least one in the adjustment of grinding endpoint or grinding rate is determined based on this series of values.

Embodiment can include one or more following characteristics.This in-situ monitoring system can measure the wavelength at least including visible ray Intensity, and this fixed wave length scope can have the width between 50 and 200 nanometers.This selected spectral signature can be spectrum Crest, spectrum trough or spectrum zero-crossing.This characteristic can be wavelength, width or intensity.

In another aspect, a kind of method controlling to grind includes: grinding base plate, this substrate has ground floor；Receive choosing Determine identification and the characteristic of this selected spectral signature of spectral signature, to monitor during grinding；Grinding the same of this substrate Time measure a series of spectrum of light from this substrate；In the time that this ground floor exposes to the open air, determine this feature this characteristic One value；Skew is added to this first value, to produce the second value；And this characteristic of supervision this feature, and determining this feature This characteristic reaches to suspend during this second value to grind.

Embodiment can include one or more following characteristics.This characteristic can be position, width or intensity.Complete at this spectra Under body, this selected feature sustainable differentiation site, width or intensity.This feature can be crest or the trough of this spectrum.This base Plate can include the second layer covering this ground floor, and the step of grinding can comprise the following steps that this second layer of grinding, and available original position Monitoring system detects exposing to the open air of this ground floor.Can be true in the time exposed to the open air of this first in-situ monitoring this ground floor of technology for detection This first value fixed.The step exposed to the open air detecting this ground floor can be the system that the step with this characteristic monitoring this feature is separated Journey.The step exposed to the open air detecting this ground floor can comprise the following steps that the supervision total reflex strength from this substrate.Monitor that this is total The step of reflex strength can comprise the following steps that for each spectrum in this spectra, integrates this light in wave-length coverage Spectrum, to produce this total reflex strength.This in-situ monitoring system can include motor torsional moment or friction monitoring system.Can be at this ground floor Grinding during (such as, start this ground floor grinding after immediately) determine this first value.Can open in the grinding of this substrate This ground floor was exposed to the open air before beginning.Monitor that the step of this characteristic of this feature can comprise the following steps that for from this spectra Each spectrum, determine the value of this characteristic, to produce a series of value.By to this series of values fitting linear function, and can determine This linear function, equal to the terminal time at this second value, determines that this characteristic of this feature reaches this second value.Can be received this Thickness before the grinding of ground floor, and this deviant can be calculated according to thickness before this grinding.The step calculating this offset value delta V can Comprise the following steps: calculate (D₂-d_T)/(dD/dV), wherein d_TFor target thickness, D1 is grinding of the ground floor from installing substrate Thickness before mill, D₂For thickness, and the thickness that dD/dV is the function as this characteristic after the grinding of this ground floor from installing substrate The rate of change of degree.The step calculating this offset value delta V can comprise the following steps that calculating Δ V=Δ V_D+(d₁-D₁)/(dD/dV) +(D₂-d_T)/(dD/dV), wherein d₁For thickness, D before this grinding₁For from installing substrate ground floor grinding before thickness, and ΔV_DFor this value of this characteristic in feature between thickness after thickness and this grinding before this grinding of this ground floor of installing substrate On difference.Thickness d before this grinding can be measured at separating and measuring station₁.The rate of change of this thickness as the function of this characteristic DD/dV, can be the rate of change close to the thickness at this grinding endpoint.This ground floor can include polysilicon and/or dielectric medium material Material, such as, is made up of the purest polysilicon, is made up of dielectric material, or be the combination of polysilicon and dielectric material.

Embodiment can optionally include one or more advantages below.Identify that wave-length coverage is special to search selected spectral signature Property, can allow at detection terminal or determine that grinding rate change can have bigger accuracy, such as, this system is surveyed at follow-up spectrum Incorrect spectral signature is unlikely selected during amount.Rather than spectrally follow the trail of spectral signature whole in wave-length coverage, Allow to identify these spectral signatures easier and faster.The process money identified required for these selected spectral signatures can be reduced Source.

The time that semiconductor maker develops the algorithm of the terminal detecting specific products substrate can be reduced.Can be by spectral signature Follow the trail of and be applied to start from the grinding operation of the grinding in reflecting layer, and thickness evenness (wafer-to-wafer between wafer can be improved thickness uniformity；WTWU).This original depth of this layer can be measured before the grinding, and can be the thickest according to this Degree and this target thickness calculate object feature value, thus provide terminal more accurately to determine.

Illustrate the details of one or more embodiment in the accompanying drawings and the following description.Want according to description and accompanying drawing and according to right Ask, other aspects, feature and advantage be will be more apparent.

Accompanying drawing explanation

Fig. 1 illustrates chemical-mechanical grinding device.

Fig. 2 is the top view of grinding pad, and diagram carries out the site of in site measurement.

Fig. 3 A illustrates the spectrum obtained by site measurement.

Fig. 3 B is shown in the differentiation grinding the spectrum obtained when carrying out by site measurement.

Fig. 4 A diagram is from the example chart of the spectrum of the light of substrate reflection.

Fig. 4 B diagram chart by Fig. 4 A of high pass filter.

Fig. 5 A diagram is from the spectrum of the light of substrate reflection.

The contour map of the spectrum that Fig. 5 B diagram is obtained by the in site measurement of the light reflected from substrate.

The example chart of Fig. 6 A diagram grinding progress, this grinding progress is to measure in the way of characteristic difference is to the time.

The example chart of Fig. 6 B diagram grinding progress, this grinding progress is to measure in the way of characteristic difference is to the time, Wherein measure the characteristic of two different characteristics, to adjust the grinding rate of substrate.

Another spectrum of the light that Fig. 7 A diagram is obtained by site measurement.

Fig. 7 B is shown in the spectrum of the light obtained after the spectrum of Fig. 7 A.

Fig. 7 C is shown in another spectrum of the light obtained after the spectrum of Fig. 7 A.

Fig. 8 illustrates selection crest with the method carrying out monitoring.

Fig. 9 illustrates the method for the target component obtaining selected crest.

The method that Figure 10 diagram determines for terminal.

Figure 11 illustrates the establishing method of end point determination.

The other method that Figure 12 diagram determines for terminal.

Figure 13 be shown in grinding during as the chart of total reflex strength of function of time.

Figure 14 is shown in the chart of the wavelength location of the spectrum crest during grinding as time function.

Each graphic in similar elements symbol and representation represent similar elements.

Detailed description of the invention

A kind of Optical Monitoring technology is to measure the spectrum of light from substrate reflection during grinding, and identify from storehouse Join reference spectra.One potential problems of spectral matching are, for some type of substrate, in lower die feature Difference between middle existence significant substrate, thus cause the change on surface with the spectrum of the substrate reflection of identical outer layer thickness Change.These changes increase the difficulty of suitable Spectral matching, and reduce the reliability of Optical Monitoring.

One technology offsetting this problem is to measure the spectrum of the light from the substrate reflection being ground, and identifies spectral signature The change of characteristic.Follow the trail of the change of the characteristic (such as, the wavelength of spectrum crest) of the feature of spectrum, the substrate in batch can be allowed Between there is more preferably lapping uniformity.By determining the goal discrepancy of spectral signature characteristic, when the value of characteristic has changed aim parameter Time, terminal can be called.

Substrate can be only the single dielectric substance layer disposed on the semiconductor layer, or has the most more complicated layer stack repeatedly.Lift For example, substrate can include ground floor and dispose the second layer on the first layer.Ground floor can be dielectric medium, such as, oxide (such as, silicon dioxide), or low dielectric radio (low-k) material, such as, the silicon dioxide of doping carbon, such as, Black Diamond^TM(from Applied Materials) or Coral^TM(from Novellus Systems Inc.).The second layer can be barrier layer, barrier layer Constituent different from ground floor.For example, barrier layer can be metal or metal nitride, such as, tantalum nitride or titanium nitride. If necessary in disposing one or more additional layer between ground floor and the second layer, such as, low dielectric radio covers material, such as, by four Ethoxysilane (tetraethyl orthosilicate；TEOS) material formed.Ground floor and the second layer are the most semi-transparent Bright.Ground floor provides the layer stack below the second layer repeatedly together with one or more additional layer (if present).But, in some embodiments In, only grind (such as) single layer containing polysilicon and/or dielectric medium (although there may be extra below the layer being ground Layer).

Can use cmp to planarize substrate, till the second layer exposes to the open air.For example, if existing impermeable Bright conductive material, then can grind this opaque conductive material, until till the second layer (such as, barrier layer) exposes to the open air.Hereafter, remove The part of the residue second layer on the first layer, and grinding base plate, until till ground floor (such as, dielectric substance layer) exposes to the open air.Separately Outward, it is sometimes desirable to grind ground floor (such as, dielectric substance layer), until remaining target thickness or till having removed target material amount.

A kind of Ginding process is, grinds conductive layer, expose at least up to the second layer (such as, barrier layer) on the first grinding pad Till dew.It addition, a part of thickness of the second layer can (such as) remove during the first grinding pad is in overpolish step.This After, substrate is transferred to the second grinding pad, wherein the second layer (such as, barrier layer) is completely removed, and lower floor's ground floor (example Such as, low dielectric radio dielectric medium) segment thickness be also removed.It addition, between ground floor and the second layer extra one or many Individual layer (if present) can be removed in the second grinding pad is in identical grinding operation.

But, when substrate is transferred to the second grinding pad, the original depth of the second layer may be not known.As above institute Stating, this situation can be that optical end point detection technique brings problem, and these optical end point detection techniques follow the trail of choosing in spectral measurement Determine spectral signature characteristic, to determine terminal at target thickness.But, if by can reliably detect the second layer remove and under Another surveillance technology exposed to the open air of layer ground floor or Rotating fields is followed the trail of to trigger spectral signature, then can alleviate this problem.It addition, mat By the original depth of measurement ground floor, and calculate object feature value by the original depth according to ground floor and target thickness, just Uniformity between the substrate of the thickness that can improve ground floor.

Spectral signature can include spectrum crest, spectrum trough, spectrum flex point or spectrum zero-crossing.The characteristic of feature can include Wavelength, width or intensity.

Fig. 1 illustrates the operable milling apparatus 20 with grinding base plate 10.Milling apparatus 20 includes rotatable circular disc shape platform 24, grinding pad 30 is positioned on this platform.Platform is operable to rotate around axle 25.For example, motor pivotable drive axle 22 with rotation platform 24.For example, by adhesive layer, grinding pad 30 can be removably fixedly held to platform 24.Grinding pad 30 when abrasion detachably and change.Grinding pad 30 can be the double-deck grinding pad with outer grinding layer 32 and softer backing layer 34.

To include that aperture (that is, run through the hole of pad) or the mode of solid form provide the optical access through grinding pad Point 36.Solid form can be fixedly held to grinding pad, but solid form may be supported on platform 24 in certain embodiments, and protrudes In aperture to grinding pad.Grinding pad 30 is generally placed on platform 24 so that aperture or form cover and be positioned platform On optical head 53 in the groove 26 of 24.Therefore optical head 53 can carry out, via aperture or form, the substrate that optical access is ground.

For example, form can be rigid crystalline or vitreous material (such as, quartz or glass), or relatively soft plastic material (such as, silica resin, polyamine formic acid esters or halogen polymer (such as, fluoropolymer)), or the combination of the material mentioned.Depending on Window can be transparent for white light.If the top surface of solid form is rigid crystalline or vitreous material, then top surface should grind certainly Mill surface is sufficiently recessed, to prevent scraping.If top surface is close and can touch lapped face, then the top surface of form should be relatively Soft plastic material.In certain embodiments, solid form is fixedly arranged in grinding pad, and is polyamine formic acid esters form, or for having The form of the combination of quartz and polyamine formic acid esters.Form can for the monochromatic light (such as, blue light or HONGGUANG) with specific color There is high-transmission rate, such as, approximate 80% absorbance.Form can be seal for grinding pad 30 so that liquid does not passes through Form and the interface of grinding pad 30 and leak.

In one embodiment, form includes rigid crystalline or the nature of glass material being covered with the outer layer of relatively soft plastic material Material.The top surface of softer material can be with lapped face copline.The basal surface of rigid material can be put down altogether with the basal surface of grinding pad Face, or recessed relative to the basal surface of grinding pad.Specifically, if grinding pad includes two layers, then solid form can be integrated into In grinding layer, and bottom can have the aperture being directed at solid form.

The basal surface of form can optionally include one or more groove.Can forming pockets, with accommodate (such as) optical cable end End or the end of vortex induction device.Groove allows to make the end of the end of optical cable or vortex induction device be positioned away from the base being ground Plate surface is less than the distance of the thickness of form.Include that rigid crystalline part or glassy portions and groove are by machinery at form In the case of being processed to form the embodiment in this part, milled grooves, in order to remove the scratch caused by machining.Or Person, can be coated on the surface of groove, to remove the scratch caused by machining by solvent and/or liquid polymers.Generally by Removing of the scratch that machining causes reduces scattering and can improve the light absorbance through form.

The backing layer 34 of grinding pad can be attached to the outer grinding layer 32 of grinding pad, such as, by adhesive agent.Offer optics is deposited The aperture taking a little 36 can be formed in pad 30 (such as, by cutting or by molding pad 30, to include aperture), and form can be inserted Enter in aperture and be fixedly held to pad 30, such as, by adhesive agent.Or, the liquid precursor of form can be distributed to pad 30 In aperture, and this predecessor is made to be cured to form form.Or, can be by (such as, the above-mentioned crystallization or glassy of solid transparent element Part) it is positioned in liquid cushion material, and liquid cushion material can be made to solidify, to form pad 30 around transparent element.Rear two In any one situation of individual situation, one piece of cushion material can be formed, and the layer containing the grinding pad moulding form can be extracted from this block.

Milling apparatus 20 includes combining slurry/rinse arm 39.During grinding, arm 39 operable with distribution containing liquid and The slurry 38 of pH-value (PH) regulator.Or, milling apparatus includes operable with by the slurry in slurry distribution to grinding pad 30 Body port.

Milling apparatus 20 includes operable to hold the substrate 10 carrier head 70 against grinding pad 30.Carrier head 70 self-supporting Structure 72 (such as, rotate bin) is suspended in midair, and is connected to carrier head rotation motor 76 by carrying drive shaft 74 so that carrying Head can rotate around axle 71.It addition, carrier head 70 can in the radial slot in being formed at supporting construction 72 oscillation crosswise.In operation In, platform rotates around Platform center axle 25, and carrier head rotates around carrier head central shaft 71 and at the top surface of grinding pad Upper transverse translation.

Milling apparatus also includes Optical Surveillance System, and this Optical Surveillance System can be used for determining that grinding is eventually as discussed below Point.Optical Surveillance System includes light source 51 and photodetector 52.Light transmits from light source 51, by the optical access in grinding pad 30 Point 36, bumped substrate 10 and be reflected back through optical access point 36 from substrate 10, and march to photodetector 52.

Dichotomous optical cable 54 can be used for transmitting to optical access point 36 light from light source 51, and from optical access point 36 to returning Transmission is to photodetector 52.Dichotomous optical cable 54 can include " main line " 55 and two " branch line " 56 and 58.

As mentioned above, platform 24 includes that groove 26, optical head 53 are positioned in groove 26.Optical head 53 holds bifurcated One end of the main line 55 of formula optical cable 54, dichotomous optical cable 54 is arranged to the substrate surface conduction light being ground and from quilt The substrate surface conduction light ground.Optical head 53 can include covering one or more lens of the end of dichotomous optical cable 54 or regarding Window.Or, optical head 53 can only hold the end of the main line 55 of the solid form being adjacent in grinding pad.Can be as required from recessed Groove 26 removes optical head 53, and (such as) safeguards to realize preventive maintenance or correcting property.

Platform includes removable in-situ monitoring module 50.In-situ monitoring module 50 can include with next or many persons: light source 51, Photodetector 52 and for sending and receive the circuit travelling to and fro between light source 51 with the signal of photodetector 52.For example, detection The output of device 52 can be via the rotary coupler (such as, slip ring) in drive shaft 22, and is transferred to the control of Optical Surveillance System The digital electronic signal of device processed.Similarly, the numeral electricity of module 50 can be transferred to from controller in response to via rotary coupler Control command in subsignal, and it is turned on and off light source.

In-situ monitoring module 50 also can hold each end of the branch portion 56 and 58 of dichotomous optical fiber 54.Light source can be grasped Making to transmit light, this light conducts via branch line 56, and the end conductive of the main line 55 being certainly positioned in optical head 53 is out, and hits Hit on the substrate being ground.Received from the end of the light of substrate reflection main line 55 in being positioned at optical head 53, and warp Conducted to photodetector 52 by branch line 58.

In one embodiment, dichotomous optical cable 54 is a branch of optical fiber.This bundle includes first group of optical fiber and second group of optical fiber. Connect the optical fiber in first group, to conduct the light from light source 51 to the substrate surface being ground.Connect the light in second group Fibre, to be received from the light of the substrate surface reflection being ground, and conducts the light received to photodetector 52.Optical fiber can be arranged, The optical fiber in second group is made to form the X shape shape being centered on the longitudinal axis of dichotomous optical fiber 54 (when at dichotomous optical cable When the cross section of 54 is observed).Or, can be implemented other and arrange.For example, the optical fiber in second group can be formed as each other The V-shape shape of mirror image.It is public that the dichotomous optical fiber being suitable for is purchased from being built in the pause Verity instrument in city of Texas's Caro Department.

At grinding pad form and closest between the end of the main line 55 of the dichotomous optical cable 54 of grinding pad form, generally There is optimum distance.This distance can empirically determine, and by the reflexive of (such as) form, the light beam launched from dichotomous optical cable Shape and the impact of distance away from monitored substrate.In one embodiment, dichotomous optical cable is positioned so that closest to The end of form is as far as possible near the bottom of form, and actually not in contact with this form.In the case of this embodiment, grind Equipment 20 can include mechanism (such as, as the part of optical head 53), and this mechanism is operable to adjust the end of dichotomous optical cable 54 Distance between end and the basal surface of grinding pad form.Or, the immediate end of dichotomous optical cable 54 is embedded in form.

Light source 51 is operable to launch white light.In one embodiment, the white light of transmitting includes having 200-800 nanometer The light of wavelength.Applicable light source is xenon lamp or xenon-mercury lamp.

Photodetector 52 can be spectrometer.Spectrometer is substantially for measuring the character of light on part electromagnetic spectrum The optical instrument of (such as, intensity).The light splitting being suitable for is calculated as grating spectrometer.The typical case of spectrometer is output as the letter as wavelength The intensity of the light of number.

Light source 51 and photodetector 52 are connected to calculate device, and this calculating device is operable to control light source 51 and light detection The operation of device 52, and receive light source 51 and the signal of photodetector 52.Calculate device can include being positioned near milling apparatus Microprocessor, such as, personal computer.About control, calculate device and (such as) startup of light source 51 and the rotation of platform 24 can be made Turn and synchronize.As shown in Figure 2, computer can make light source 51 launch a series of flash of light, and this series of flashes is crossed at substrate 10 just Start before in-situ monitoring module 50, and just terminate after in-situ monitoring module 50 crossed by substrate 10.In some 201-211 Each all represents that the light from in-situ monitoring module 50 strikes against on substrate 10 and from the site of substrate 10 reflection.Or, meter Calculation machine can make light source 51 launch light continuously, and this light started just before in-situ monitoring module 50 crossed by substrate 10, and just exists Substrate 10 terminates after crossing in-situ monitoring module 50.

When grinding is carried out, (such as) induction apparatus in the platform spectrum that scanning obtains continuously on substrate provides one Spectra.In certain embodiments, light source 51 is by the some of the flash light emission of a series of light to substrate 10.Citing and Speech, light source can be by the outer portion of the core of the flash light emission of light to substrate 10 and substrate 10.Can be connect by photodetector 52 Receive the light from substrate 10 reflection, to determine multiple spectra of the some from substrate 10.Each feature all with substrate These features recognizable in the spectrum that one part of 10 is associated.For example, feature can be used for determining for substrate 10 The end-condition ground.In certain embodiments, the supervision of the some of substrate 10 allows one or more of change substrate 10 Grinding rate in part.

About receiving signal, calculating device can receive (such as) and carry the spectrum describing the light received by photodetector 52 The signal of information.The reality of the spectrum that Fig. 3 A diagram measures according to the single flash light emission from light source and the flash ranging from substrate reflection Example.Spectrum 302 is to measure according to the light from the reflection of product substrate.Spectrum 304 is according to from base material silicon substrate (this base material silicon Substrate is the wafer only with silicon layer) light that reflects measures.Spectrum 306 is from there is not the base being positioned on optical head 53 In the case of plate, optical head 53 light received.Under this condition (being referred to as dark condition in this manual), receive Light is usually ambient light.

Calculate device and can process above-mentioned signal or a part for above-mentioned signal, to determine the terminal of grinding steps.Do not limiting In the case of any particular theory, carry out along with grinding from the spectrum of the light of substrate 10 reflection and develop.Fig. 3 B provides spectrum Along with the example grinding of thin film interested carried out and develop.Different spectral line represent the different time ground in processing procedure Point.As can be seen, when the thickness of thin film changes, the character of the spectrum of reflection light changes, and special spectrum is by the spy of thin film Determine thickness to show.When observing crest (that is, local maximum) in the spectrum of reflection light when the grinding of thin film is carried out, The height of crest generally changes, and along with material removes, crest tends to broaden.In addition to broadening, the ripple at specific crest place Length generally carries out along with grinding and increases.In certain embodiments, the wavelength at specific crest place is generally along with grinding is carried out Reduce.For example, crest 310 (1) is shown in the crest in the spectrum of the special time during grinding, and crest 310 (2) figure Show the identical crest of time after a while during grinding.Crest 310 (2) is positioned at longer wavelength, and wider than crest 310 (1).

Can rule of thumb formula, the wavelength of use crest and/or the change relatively of width (such as, fix below crest The width that distance is measured, or at crest and the width measured at intermediate altitude between trough recently), crest absolute Wavelength and/or width or above-mentioned both determine the terminal of grinding.Optimal crest (or the multiple ripple used when determining terminal Peak) depend on that ground material and the pattern of these materials change.

In certain embodiments, the change of peak wavelength may be used to determine terminal.For example, when the start wavelength of crest And when the difference between the current wavelength of crest reaches goal discrepancy, milling apparatus 20 can stop grinding base plate 10.Or, can use and remove Feature beyond crest determines the difference of the wavelength of the light from substrate 10 reflection.For example, can be monitored by photodetector 52 The wavelength of trough, flex point or x-axle or y-y-intercept, and when wavelength changes scheduled volume, milling apparatus 20 can stop grinding base Plate 10.

In certain embodiments, in addition to wavelength, width that the characteristic monitored can be characterized or intensity, also can not supervise Apparent wavelength.Feature can offset about 40nm to 120nm, but other side-play amounts are also possible.For example, the upper limit can big obtain Many, especially under the situation that dielectric medium grinds.

The example of the spectrum 400a that Fig. 4 A offer measures from the flash ranging of substrate 10 reflection.Optical Surveillance System can make spectrum 400a passes through high pass filter, to reduce the global slopes of spectrum, thus produces the spectrum 400b shown in Fig. 4 B.Citing and Say, during the multiple substrates in processing batch, bigger spectral differences can be there is between wafer.High pass filter can be used Normalization spectrum, to reduce the spectrum change on the substrate in same batch.Exemplary high pass filter can have 0.005Hz's Cut-off frequency and filter order (filter order) 4.High pass filter is not only in order to help to leach the spirit to lower floor's change Sensitivity, and also in order to " graduation " legal signal, so that tracking features is easier to.

In order to allow user select by follow the trail of terminal which feature to determine this terminal, can produce contour map and to User shows these high line charts.Fig. 5 B provides the multiple spectral measurements according to the light reflected from substrate 10 during grinding to produce The example of contour map 500b, and Fig. 5 A provides the reality of measure spectrum 500a from the specified moment in contour map 500b Example.Contour map 500b includes feature, such as, the correlation peak 502 on spectrum 500a and trough 504 and the peak regions produced 502 and valley regions 504.Elapsing over time, substrate 10 is ground, and changes, as by contour map from the light of substrate reflection Illustrated in the change of the spectral signature in 500b.

For producing contour map 500b, test substrate can be ground, and can be measured certainly by photodetector 52 during grinding The light of test substrate reflection, to be produced from the spectra of the light of substrate 10 reflection.Spectra can be stored (such as) in meter In calculation machine system, this computer system can be optionally the part of Optical Surveillance System.The grinding of installing substrate can be at time T1 Place starts, and continues to exceed estimation terminal time.

When test substrate grinding complete time, computer (such as) on the computer monitor, to the behaviour of milling apparatus 20 Contour map 500b is presented as member.In certain embodiments, computer color labelling contour map, such as, refer to by by redness Calmly to the higher-strength value in spectrum, the relatively low intensity value that blueness is assigned in spectrum, and by Neutral colour (orange to green) The middle intensity value being assigned in spectrum.In other embodiments, computer produces GTG contour map, by by lead The relatively low intensity value that shade is assigned in spectrum, and the higher-strength value that the brightest gray shade is assigned in spectrum, and will The middle intensity value that middle shade is assigned in spectrum.Or, computer can produce three-dimensional contour map, wherein by maximum z value Represent the higher-strength value in spectrum, and represent the relatively low intensity value in spectrum by minimum z value, represent in spectrum by middle z value Intermediate value.For example, three-dimensional contour map can show in the way of colored, GTG or black and white.In certain embodiments, grind The operator of mill equipment 20 can be interactive, to observe the different characteristic of spectrum with three-dimensional contour map.

For example, during grinding, the contour map 500b monitoring the reflection light produced of self-test substrate can be containing all Such as crest, trough, spectrum zero-crossing point and the spectral signature of flex point.Feature can have such as wavelength, width and/or the spy of intensity Property.As shown by contour map 500b, when grinding pad 30 removes material from the top surface of installing substrate, certainly install substrate The light of reflection can passage in time and change, therefore feature passage in time and change.

Before the grinding of device substrate, the operator observable contour map 500b of milling apparatus 20 also selects feature special Property, to be tracked during the process of a collection of substrate having and install the similar die characteristics of substrate.For example, grinding sets The operator of standby 20 may select the wavelength of crest 506 to be tracked.Contour map 500b (especially colour-coded or three-dimensional etc. High line chart) potential advantage be, this kind of figure shows allows user can be easier to select appropriate feature, due to feature (such as, There is the feature of the characteristic changed linearly over time) it is visually can easily distinguish.

In order to select terminal criterion, can based on test substrate grinding before thickness and grind after thickness, by linear interpolation Method calculates the characteristic of selected feature.For example, thickness D1 and D2 of the layer on test substrate can distinguish (example before the milling As, before grinding the time T1 started, test the thickness of substrate) with after grinding (such as, grind the time T2 that terminates it The thickness of rear test substrate) measure, and the value of characteristic can be measured at the time T' of target thickness D' reaching.T' can be by T '=T1 + (T2-T1) * (D2-D ')/(D2-D1) calculates, and value V' of characteristic can determine according to the spectrum measured at time T'. The goal discrepancy δ V of the characteristic of selected feature (such as, the specific change in the wavelength of crest 506) can be determined according to V '-V1, its Middle V1 is initial characteristic values (at time T1).Therefore, goal discrepancy δ V can be the initial characteristic values before grinding at time T1 V1 is to the change of value V' of the characteristic at the time T' estimate grinding.The operator of milling apparatus 20 can be intended to change In the computer that goal discrepancy 604 (such as, the δ V) input of feature is associated with milling apparatus 20.

In order to determine value V', and correspondingly determine the value of a little 602, sane formula line matching can be used to come to the data measured and intend Zygonema 508.The value of the line 508 at time T' can be deducted the value of line 508 at T1, to determine a little 602.

Can feature based characteristic goal discrepancy and during grinding dependency between the installing quantity of material that removes of substrate, Select the feature of such as spectrum crest 506.The operator of milling apparatus 20 may select different characteristic and/or feature, with Find out and have individual goal discrepancy and the feature of the good correlation between the quantity of material that installing substrate removes.

In other embodiments, terminal determines that logic determines the spectral signature to be followed the trail of and terminal criterion.

Turning now to the grinding of device substrate, Fig. 6 A is the difference of the feature followed the trail of during the grinding of device substrate 10 Example chart 600a of 602a-d.Substrate 10 can be the part in a collection of substrate being ground, the wherein behaviour of milling apparatus 20 Select feature (such as, crest or the wavelength of trough) as member, be tracked with the contour map 500b according to installing substrate.

When grinding base plate 10, the spectrum of the light from substrate 10 reflection measured by photodetector 52.Terminal determines that logic uses The spectrum of light determines the series of values of feature.Along with the surface from substrate 10 removes material, the value of selected feature can Change.The difference between series of values and the initial value V1 of feature of feature is used to determine difference 602a-d.

When grinding base plate 10, terminal determines that logic can determine that the currency of tracked feature.Implement at some In example, when the currency of feature has changed goal discrepancy 604 from initial value, terminal can be called.In certain embodiments, (example As) use sane formula line matching, to difference 602a-d fit line 606.The function of line 606 can be determined based on difference 602a-d, To predict the grinding endpoint time.In certain embodiments, this function is the time linear function to characteristic difference.When calculating new difference Time, the function (such as, slope and intercept) of line 606 can change during the grinding of substrate 10.In certain embodiments, line 606 The time reaching goal discrepancy 604 provides estimation terminal time 608.When the function of line 606 changes to receive new difference, estimate eventually The point time 608 can change.

In certain embodiments, use the function of line 606 to determine the quantity of material removed from substrate 10, and use by this letter The change of the currency that number determines determines when reach goal discrepancy and when need to call terminal.The material removed followed the trail of by line 606 Doses.Or, when removing the material of specific thicknesses from substrate 10, the change of the currency determined by function just can be used to come really Quantity of material that the fixed top surface from substrate 10 removes and when call terminal.For example, goal discrepancy can be set as by operator Wavelength change 50 nanometer of selected feature.For example, the change that can use the wavelength of selected crest determines from substrate 10 Top layer removes how many materials and when calls terminal.

At time T1, before the grinding of substrate 10, the characteristic value difference of selected feature is 0.When grinding pad 30 starts to grind During mill substrate 10, the characteristic value knowing another characteristic can grind away from the top surface of substrate 10 along with material and change.For example, During grinding, the Wavelength variable of selected feature is higher or lower wavelength.Get rid of noise effect, the wavelength of feature The difference of wavelength (and therefore) tends to dull change, and the most linear changes.At time T', terminal determines that logic determines knowledge Another characteristic characteristic has changed goal discrepancy δ V, and can call terminal.For example, goal discrepancy has been changed when the wavelength of feature During 50 nanometer, call terminal and grinding pad 30 stops grinding base plate 10.

When processing a collection of substrate, Optical Surveillance System 50 (such as) can follow the trail of the same spectra feature on all substrates. Spectral signature can be associated with the same die feature on substrate.Lower floor based on substrate changes, the start wavelength of spectral signature Can change between substrate in batch.In certain embodiments, in order to minimize the transmutability on multiple substrate, when selected feature is special Property value or matching to the function of the value of feature when changing terminal tolerance EM (rather than goal discrepancy), terminal determines that logic is adjustable Use terminal.Terminal determines that logic can use the expection initial value EIV determined according to installing substrate.Chased after on the substrate 10 identifying At the time T1 of the feature of track, terminal determines that logic determines the actual initial value AIV of processed substrate.Terminal determines patrols Collect and can use initial value weight IVW, to reduce the impact that terminal is determined by actual initial value, take into account a batch upper substrate simultaneously Change.For example, substrate change can include the thickness of substrate thickness or understructure.Initial value weight can change phase with substrate Close, to increase the uniformity between processing between substrate.For example, can be by initial value weight being multiplied by actual initial value with pre- Difference between initial initial value and plus goal discrepancy, determines that terminal is measured, such as, and EM=IVW* (AIV EIV)+δ V.

In certain embodiments, use that set of weights is incompatible determines terminal.For example, terminal determines that logic can be according to function The initial value of estimated performance, and according to the currency of function estimated performance, and it is poor to calculate first between initial value and currency. Terminal determines that logic can calculate between initial value and desired value second is poor, and produces the weighted array of the first difference and the second difference.

Fig. 6 B is the feature measurement difference obtained at two parts of substrate 10 example chart 600b to the time.Citing For, the traceable marginal portion towards substrate 10 of Optical Surveillance System 50 and a feature positioning and towards in substrate 10 Heart part and another feature of positioning, to determine remove how many materials from substrate 10.When test installing substrate, milling apparatus The operator of 20 (such as) can identify that two features of different piece corresponding to installing substrate are to be tracked.Implement at some In example, spectral signature is corresponding with the die characteristics of the same type on installing substrate.In other embodiments, spectral signature with Different types of die characteristics on installing substrate is associated.When substrate 10 is ground, photodetector 52 can measure from The spectra of the reflection light of two parts of the corresponding substrate 10 of selected feature of installing substrate.Logic can be determined by terminal Determine the series of values that the characteristic with two features is associated.By when milling time is advanced, current properties value can be deducted Initial characteristic values, and calculate a series of first differences 610a-b of the feature in the Part I of substrate 10.Can be similarly A series of second differences 612a-b of the feature in the Part II of calculating substrate 10.

Can be to the first difference 610a-b matching First Line 614, and can be to second difference 612a-b matching the second line 616.Can Determine First Line 614 and the second line 616 with the first function and the second function respectively, with determine estimation the grinding endpoint time 618 or Adjustment to the grinding rate 620 of substrate 10.

During grinding, use the first function of the Part I of substrate 10, and the second of the Part II of use substrate Function, carries out endpoint calculation based on goal discrepancy 622 at time TC.If the Part II of the Part I of substrate and substrate Estimate that terminal time is different (such as, Part I will reach target thickness before Part II), then can be to grinding rate 620 It is adjusted so that the first function and the second function will have the same endpoint time 618.In certain embodiments, substrate is adjusted The grinding rate of Part I and Part II so that at two parts, reach terminal simultaneously.Or, adjustable first Divide or the grinding rate of Part II.

For example, can be by the pressure in the respective regions that carrier head 70 is increased or decreased to adjust grinding rate.Grind Mill speed change can be assumed that for pressure be changing into direct ratio, such as, simple Bu Ruisidun (Prestonian) model.Citing For, when the first area of substrate 10 plans to reach target thickness at time TA, and during the built vertical object time TT of system, time Between carrier head pressure in respective regions before T3 can be multiplied by TT/TA, to provide carrier head pressure after the time t 3.Separately Outward, can be developed for the Controlling model of grinding base plate, this Controlling model takes into account platform or the impact of head rotary speed, different head pressure The second-order effects of power combination, grinding temperature, slurry flow or affect other parameters of grinding rate.After during grinding processing procedure The continuous time, if suitably, then can again adjust speed.

In certain embodiments, calculate device and use wave-length coverage, to easily identify the light from device substrate 10 reflection The measured selected spectral signature in spectrum.Calculate device and in wave-length coverage, search selected spectral signature, to distinguish choosing Determine other of the selected spectral signature that spectral signature and (such as) be similar in the spectrum measured on intensity, width or wavelength Spectral signature.

Fig. 7 A diagram is according to the example of the spectrum 700a of the photo measure received by photodetector 52.Spectrum 700a includes selecting Spectral signature 702, such as, spectrum crest.By terminal, selected spectral signature 702 can determine that logic selects, with at substrate 10 It is tracked during CMP.The characteristic 704 (such as, wavelength) of selected spectral signature 702 can be determined logic identification by terminal.Work as spy When property 704 changes goal discrepancy, terminal determines that logic calls terminal.

In certain embodiments, terminal determines that logic determines wave-length coverage 706, to search selected light in this wave-length coverage Spectrum signature 702.Wave-length coverage 706 can have the width between about 50 and about 200 nanometers.In certain embodiments, wavelength Scope 706 is predetermined, such as, by operator's regulation (such as, the user input by receiving chosen wavelength range), or rule The process parameter being set to a collection of substrate (goes out wavelength model by from the memory search making wave-length coverage be associated with this batch of substrate Enclose).In certain embodiments, wave-length coverage 706 is based on historical data, such as, and even average or maximum between sequence spectral measurement Distance.In certain embodiments, wave-length coverage 706 is based on the information about test substrate, such as, twice goal discrepancy δ V.

Fig. 7 B is the example of the spectrum 700b measured from the flash ranging received by photodetector 52.For example, at platform 24 Rotation during followed by obtain spectrum 700a after, measure spectrum 700b.In certain embodiments, terminal determines that logic determines The previously value (such as, 520nm) of the characteristic 704 in spectrum 700a, and adjust wave-length coverage 706 so that in wave-length coverage 708 The heart positions closer to characteristic 704.

In certain embodiments, terminal determines that logic uses the function of line 606 to determine the expection currency of characteristic 704. For example, terminal determine logic can use current milling time determine expection poor, and by by expection differ from add to characteristic 704 Initial value V1 determine the expection currency of characteristic 704.Terminal determines that wave-length coverage 708 can be centered in characteristic by logic On the expection currency of 704.

Fig. 7 C is another example of the spectrum 700c measured from the flash ranging received by photodetector 52.For example, flat And then after obtaining spectrum 700a during the rotation of platform 24, measure spectrum 700c.In certain embodiments, terminal determines logic The preceding value of characteristic 704 is used for the center of wave-length coverage 710.

For example, terminal determines that logic determines that two company's sequences of the optical head 53 below substrate 10 determine during transmitting Characteristic 704 value between average variance.Terminal determines that the width setup of wave-length coverage 710 can be average variance by logic Twice.In certain embodiments, terminal determines that logic, when determining the width of wave-length coverage 710, uses between the value of characteristic 704 The standard deviation of variance.

In certain embodiments, the width of wave-length coverage 706 is the most identical for all spectral measurements.For example, wavelength The width of scope 706, wave-length coverage 708 and wave-length coverage 710 is identical.In certain embodiments, the width of wave-length coverage is different. For example, when evaluation characteristic 704 is from previously measured change 2 nanometer of characteristic, the width of wave-length coverage 708 is 60 nanometers. When evaluation characteristic 704 is from previously measured change 5 nanometer of characteristic, the width of wave-length coverage 708 is 80 nanometers, the ripple of 80 nanometers Long scope is bigger compared with the wave-length coverage of little characteristic variations than having.

In certain embodiments, wave-length coverage 706 is the most identical for all spectral measurements during the grinding of substrate 10.Lift For example, wave-length coverage 706 is 475 nanometers to 555 nanometers, and all spectrum for carrying out during the grinding of substrate 10 are surveyed Amount, terminal determines searches selected spectral signature 702 in logic wavelength between 475 nanometers and 555 nanometers, but other wavelength Scope is also possible.Wave-length coverage 706 can be chosen as by the full spectral region of in-situ monitoring systematic survey by user input Subset.

In certain embodiments, terminal determines that logic, in the amendment wave-length coverage of some spectral measurements, and is being used for The wave-length coverage of the previous spectrum in the residue person of spectrum is searched selected spectral signature 702.For example, terminal determines logic Measure during the wave-length coverage 706 of the spectrum measured during the first rotation of platform 24, and company's sequence rotation of platform 24 and arrive Spectrum wave-length coverage 708 in search selected spectral signature 702, two of which is measured all to enter in the first area of substrate 10 OK.Continuing this example, terminal determines in the wave-length coverage 710 of two spectrum that logic is measured during same platform rotates, Searching another and select spectral signature, two of which is measured and is carried out being different from the second area of first area of substrate 10.

In certain embodiments, selected spectral signature 702 is spectrum trough or spectrum zero-crossing point.In some embodiments In, characteristic 704 is that crest or the intensity of trough or width (such as, are measured, or at crest at crest fixed distance below And the width measured at the intermediate altitude between nearest trough).

Fig. 8 diagram is used for selecting goal discrepancy δ V, with the method 800 used when determining the terminal grinding processing procedure.Measure tool There is the character (step 802) of substrate with product substrate identical patterns.Measured substrate is referred to as " installing " in this manual Substrate.Installing substrate may simply be the substrate similar or identical with product substrate, or installing substrate can be from a collection of One substrate of product substrate.The character measured can include grinding of the thin film interested at the specific site interested on substrate Thickness before mill.Generally, the thickness of multiple site is measured.It is generally selected site, to measure the pipe of the same type in each site Core feature.Measurement can be performed at measuring station.Before the grinding, Optical Surveillance System can measure the light of the light from substrate reflection in situ Spectrum.

Grind installing substrate according to grinding steps interested, and be collected in the spectrum (step obtained during grinding 804).Can perform to grind and spectral collection at above-mentioned milling apparatus.By in-situ monitoring system to collect spectrum during grinding. Overmastication substrate (that is, grind and exceed estimation terminal) so that the light from substrate reflection when reaching target thickness can be obtained Spectrum.

Measure the character (step 806) of the substrate of overmastication.Character is included in for grinding one or more of pre-test Thickness after the grinding of the thin film interested at specific site.

The spectrum using thickness and the collection measured selects (spectrum collected by inspection), and special characteristic is (such as, Crest or trough), to carry out monitoring (step 808) during grinding.Feature can be selected by the operator of milling apparatus, or The selection of feature can be (such as, to select based on conventional crest seeking (peak-finding) algorithm and experience crest automatically (peak-selection) formula).For example, as above in reference to described by Fig. 5 B, can be to the operator of milling apparatus 20 Present contour map 500b, and operator can select feature to be tracked from contour map 500b.If anticipated special spectrum district Territory containing the feature being hopeful during grinding to carry out to monitor (such as, by past experience, or calculating based on theoretical characteristic behavior Produce), the most only need the feature considered in this region.Being generally selected a feature, this feature shows when grinding base plate Dependency between the quantity of material of the top removal of installing substrate.

Can use measure to grinding before film thickness and grind metacoxal plate thickness to perform linear interpolation, reach to determine Become the approximate time of target film thickness.Can be by this approximate time compared with spectrum contour map, to determine selected feature End point values.Difference between end point values and the initial value of feature can use as goal discrepancy.In certain embodiments, to The value fitting function of feature, with the value of normalization feature.Difference between the initial value of the end point values function of function, Can use as goal discrepancy.Same characteristic features is monitored during the grinding of remaining substrate of this batch of substrate.

Optionally, spectrum is processed to improve accuracy and/or precision.For example, spectrum can be processed, so that spectrum is regular Turn to share reference, with by average for spectrum and/or with from spectral filtering noise.In one embodiment, should by low pass filter For spectrum, so that sudden peaks is reduced or eliminated.

Logic is determined for specific terminal, selects the spectral signature to be monitored the most by rule of thumb so that at computer installation When calling terminal by applying endpoint logic based on special characteristic, reach target thickness.Terminal determines that logic uses feature special Goal discrepancy in property determines when to call terminal.When grinding beginning, can measure relative to the initial characteristic values of feature The change of characteristic.Or, in addition to goal discrepancy δ V, end can be called relative to expection initial value EIV and actual initial value AIV Point.Difference between actual initial value and expection initial value can be multiplied by initial value weight SVW, to compensate between substrate by endpoint logic Lower floor changes.For example, as terminal tolerance EM=SVW* (AIV EIV)+δ V, terminal determines that logic can terminate to grind.

In certain embodiments, use that set of weights is incompatible determines terminal.For example, terminal determines that logic can be according to function The initial value of estimated performance, and according to the currency of function estimated performance, and it is poor to calculate first between initial value and currency. Terminal determines that logic can calculate between initial value and desired value second is poor, and produces the weighted array of the first difference and the second difference. Terminal can be called in the case of weighted value reaches desired value.Terminal determine logic can by the supervision of comparative characteristic difference (or Multiple differences) and goal discrepancy, determine when to call terminal.If the difference monitored is mated with goal discrepancy or exceedes goal discrepancy, then adjust Use terminal.In one embodiment, the difference of supervision must mate or exceed goal discrepancy to reach a certain period (such as, flat with goal discrepancy Platform rotates twice) just call terminal.

Fig. 9 diagram determines what the selected spectral signature of logic was associated for choosing with specific objective thickness and specific terminal The method 901 of the desired value of characteristic.As above described in step 802-806, measure and grind installing substrate (step 903). Specifically, collect spectrum, and store the time measuring each spectrum collected.

Calculate the grinding rate (step 905) of the milling apparatus for specific installing substrate.Front thickness can be ground by using After degree D1 and grinding, thickness D2 and actual milling time PT calculate average abrasive speed PR, such as, PR=(D2-D1)/PT.

Calculate the terminal time (step 907) of specific installing substrate, to provide check point, to determine the characteristic of selected feature Desired value, as discussed below.Can based on calculate grinding rate PR, thin film interested grinding before initial thickness ST and The target thickness TT of thin film interested calculates terminal time.Assuming that grinding rate is constant during whole grinding processing procedure, can Terminal time is calculated as simple linear interpolation, such as, ET=(ST-TT)/PR.

Optionally, can be by another substrate ground in this batch of patterned substrate, stop grinding at the terminal time calculated Grind and measure the thickness of thin film interested, assess the terminal time calculated.If thickness is satisfied with scope at target thickness In, then the terminal time calculated is satisfied.Otherwise, calculated terminal time can be recalculated.

At the terminal time calculated, the target property value of feature selected in the spectrum record collected at from installing substrate (step 909).If parameter interested relates to site or the change of width of selected feature, then can calculate by inspection The spectrum collected during period before terminal time, determines this information.Poor quilt between initial value and the desired value of characteristic It is recorded as the goal discrepancy of feature.In certain embodiments, single goal discrepancy is recorded.

Figure 10 diagram determines logic for use terminal based on crest, the method determining the terminal of grinding steps 1000.Above-mentioned milling apparatus is used to grind another substrate (step 1002) in this batch of patterned substrate.

Receive the selected identification of spectral signature, wave-length coverage and the characteristic (step 1004) of selected spectral signature.Citing and Speech, terminal determines that logic receives from computer and identifies, this computer has the processing parameter for substrate.In some embodiments In, processing parameter is based on the information determined during the process of installing substrate.

Initially grinding base plate, measures from the light of substrate reflection to produce spectrum, and in the wave-length coverage of the spectrum measured Determine the characteristic value of selected spectral signature.During each rotation of platform, perform following steps.

Measure one or more spectrum of light from the substrate surface reflection being ground, with obtain that current platform rotates one or Multiple current light spectrum (step 1006).Optionally process one or more spectrum of the measurement that current platform rotates, to improve accurately Degree and/or precision, above in reference to as described in Fig. 8.If only measuring a spectrum, then this spectrum is used as current light spectrum. If platform wheel measuring to be gone out more than one current light spectrum, then current light spectrum is grouped, is averaging in each group, and meansigma methods table Show current light spectrum.Spectrum can be grouped according to the radial distance at the center away from substrate.

For example, the first current light spectrum can be obtained from Zi the spectrum measured from point 202 and 210 (Fig. 2), can be from from point The spectrum measured at 203 and 209 obtains the second current light spectrum, can obtain the 3rd from Zi the spectrum measured at point 204 and 208 Current light spectrum, etc..Can determine that the characteristic value of the selected spectrum crest of each current light spectrum, and can be in the regional of substrate Monitor grinding respectively.Or, the condition worst of the characteristic of selected spectrum crest can determine according to current light spectrum, and can be by end Point determines that logic uses.

During each rotation of platform, one or more spectrum extra can be added the spectra to front substrate.When grinding When mill is carried out, at least some spectrum in series is different, owing to during grinding, material removes from substrate.

As above in reference to described by 7A-C figure, produce amendment wave-length coverage (step 1008) of current light spectrum.Citing For, endpoint logic determines the amendment wave-length coverage of current light spectrum based on previous characteristic value.During amendment wave-length coverage can be made fixed The heart is on previous characteristic value.In certain embodiments, amendment wave-length coverage, such as, wavelength model are determined based on expection characteristic value The center enclosed overlaps with expection characteristic value.

In certain embodiments, use different methods to determine some wave-length coverages of current light spectrum.For example, by Wave-length coverage is centered in the same edge region of comfortable substrate on the characteristic value of the previous spectrum measured, determines certainly The wave-length coverage of the spectrum that the photo measure of reflection arrives in the marginal area of substrate.Continue this example, by wave-length coverage is fixed Center on the expection characteristic value of central area, determine Zi the photo measure reflected in a central region of the substrate to the ripple of spectrum Long scope.

In certain embodiments, the width of the wave-length coverage of current light spectrum is identical.In certain embodiments, some current light The width of the wave-length coverage of spectrum is different.

Identify that wave-length coverage, to search selected spectral signature characteristic, can allow the detection for terminal or grinding rate change The bigger accuracy of determination, such as, system less can select incorrect spectral signature during subsequent optical spectrometry.At ripple Spectral signature is spectrally followed the trail of, it is allowed to identify spectral signature easier and faster in long scope rather than whole.Can subtract Few process resource identified required for selected spectral signature.

Self-modifying wave-length coverage extracts current properties value (step 1010) of selected crest, and uses above upper at Fig. 8 The terminal being discussed below determines logic, compares current properties value and target property value (step 1012).For example, according to Spectra determines the series of values of current signature characteristic, and to this series of values fitting function.For example, function can be linear letter Number, this linear function can carry out approximate evaluation during grinding from substrate based on the difference between current properties value and initial characteristic values The quantity of material removed.

Meet end-condition (the "No" branch of step 1014) as long as terminal determines logic to determine not yet, just allow grinding to continue Continuous, and repeat in due course step 1006,1008,1010,1012 and 1014.For example, terminal determines that logic is based on function Determine the goal discrepancy not yet reaching feature.

In certain embodiments, when the light time spectrum of the light of the some reflections measured from substrate, terminal determines logic Can determine that the grinding rate needing to adjust one or more part of substrate so that in the identical time or complete many close to the identical time The grinding of individual part.

When terminal determines logic to determine and meets end-condition (branch's "Yes" of step 1014), call terminal, and stop Only grind (step 1016).

Can normalization spectrum, to remove or to reduce the impact of unwanted luminous reflectance.Except the thin film that one or more is interested Luminous reflectance produced by medium in addition, including from grinding pad form and the luminous reflectance of the base material silicon layer from substrate.Can mat By measuring what in-situ monitoring system (that is, when not being seated in in-situ monitoring system by substrate) under dark condition received The spectrum of light, estimates the luminous reflectance from form.Can by measuring the spectrum of light of bare silicon substrate reflection, estimate from The luminous reflectance of silicon layer.Before the beginning of grinding steps, generally obtain these luminous reflectance.The following is the primary light of normalization measurement Spectrum:

Normalization spectrum=(A Dark)/(Si Dark)

Wherein A is original spectrum, and Dark is the spectrum obtained under dark condition, and Si is to obtain from bare silicon substrate Spectrum.

In the described embodiment, the change of the wavelength emission peak in spectrum is used to perform end point determination.Also ripple can be replaced Peak or combine crest and use the change of wavelength trough in spectrum (that is, local minimum).Also can use when detecting terminal The change of multiple crests (or trough).For example, each crest can be monitored individually, and when the change of most of crests meets eventually Terminal can be called during point condition.In other embodiments, the change of flex point or spectrum zero-crossing can be used to determine end point determination.

In certain embodiments, after algorithm installing processing procedure 1100 (Figure 11), use trigger-type tracking features technology The grinding of one or more substrate of 1200 (Figure 12).

Initially, (such as) uses a technology in above-mentioned technology, selects the characteristic of feature of interest in spectrum, with For in the grinding of tracking ground floor (step 1102).For example, feature can be crest or trough, and characteristic can be crest Or the position in the wavelength of trough or frequency or width, or crest or the intensity of trough.If the characteristic of feature interested can be fitted For having the multiple product substrate of different pattern, then can be by the preselected feature of equipment manufacturers and characteristic.

It addition, determine grinding rate dD/dt (step 1104) close to grinding endpoint.For example, can be according to being ready to use in Grinding processing procedure to the grinding of product substrate, but with the different milling times close to expection terminal milling time, grind multiple Installing substrate.Installing substrate can have the pattern identical with product substrate.For each installing substrate, grinding of layer can be measured Thickness before mill and after grinding, and removal quantity can be calculated according to difference, and store the removal quantity of this installing substrate and relevant when grinding Between, to provide data set.Can be to this data set matching as the linear function of the removal quantity of the function of time；This linear function Slope provides grinding rate.

Algorithm installing processing procedure includes original depth D1 (step 1106) measuring the ground floor of installing substrate.Installing substrate can There is the pattern identical with product substrate.Ground floor can be dielectric medium, such as, and low dielectric radio material, such as, the dioxy of doping carbon SiClx, such as, Black Diamond^TM(from Applied Materials) or Coral^TM(from Novellus Systems Inc.).

Optionally, depending on the constituent of the first material, deposition is different from first and second material (example on the first layer As, low dielectric radio covers material, such as, tetraethoxysilane (TEOS)) another material (such as, dielectric material) one or Multiple additional layers (step 1107).There is provided layer stack repeatedly together with one or more additional layer of ground floor and this.

It follows that deposit on ground floor or layer stack change different the second material (such as, nitride, such as, tantalum nitride or Titanium nitride) the second layer (such as, barrier layer) (step 1108).It addition, can on the second layer (and by ground floor pattern provide Groove in) deposition conductive layer, such as, metal level, such as, copper (step 1109).

Can except grind during use Optical Surveillance System in addition to measurement system at perform measurement, such as, embedded or Separating and measuring station, such as, uses contourograph or the optical measurement station of elliptical polarizer.Technology (such as, profile is measured for some Instrument) for, at the original depth of the pre-test ground floor of the deposition second layer, but it is (such as, oval inclined to measure technology for other Light instrument) for, measurement can be performed before or after the deposition second layer.

Hereafter, installing substrate (step 1110) is ground according to grinding processing procedure interested.For example, can grind first The place of station uses the first grinding pad, grinds and remove conductive layer and portion of second layer (step 1110a).Hereafter, can grind second Mill uses the second grinding pad to grind and remove the second layer and segments first layer (step 1110b) at station.However, it should be noted that it is right For some embodiments, there is not conductive layer, such as, the second layer is to grind outermost layer when starting.

At least the second layer remove period, thereby increases and it is possible to during the whole grinding operation at the second grinding stations, use Technology of stating collects spectrum (step 1112).It addition, use separation detection technique to detect the removing of the second layer and the exposure of ground floor Dew (step 1114).For example, ground floor can be detected by motor torsional moment or the sudden change of the overall strength from the light of substrate reflection Expose to the open air.Time T in the removing second layer being detected₁Place, stores value V of the characteristic of the feature interested of spectrum₁.Also may be used Store time T removing being detected₁。

After the detection removed, can suspend at Preset Time and grind (step 1118).Preset Time is sufficiently large so that grind Mill suspends after exposing ground floor to the open air.Select Preset Time so that after grinding, thickness is substantial access to target thickness, thus can be assumed that Grinding rate is linear after grinding between thickness and target thickness.Grinding at the time suspended, can detect and store spectrum Value V of characteristic of feature interested₂, also can store and grind the time T suspended₂。

Such as, use the measurement system identical with in order to measure original depth, measure thickness D after the grinding of ground floor₂ (step 1120).

Goal-selling changes delta V of the value of estimated performance_D(step 1122).It is right that the goal-selling change of this value would be used for In the endpoint detection algorithm of product substrate.Can be according to the value at the time in the removing of the second layer and the time suspended in grinding Difference between the value at place, calculates the change of this goal-selling, that is, Δ V_D=V₁-V₂。

Calculate close at the end of grinding operation, as the rate of change dD/dV of thickness of the function of the characteristic monitored (step 1124).For example, it is assumed that monitoring the wavelength location of crest, then rate of change is represented by for every angstrom of crest Wavelength location skew, angstrom number of removal of material.As another example, it is assumed that monitoring the band width of crest, then Rate of change is represented by the skew of the frequency of the width for every hertz of crest, angstrom number of removal of material.

In one embodiment, can come simple according to the value at the exposure time of the second layer and at the end ground Calculate the rate of change dV/dt of the value of the function as the time, such as, dV/dt=(D₂-D₁)/(T₂-T₁).In another embodiment In, use end (such as, the T from the grinding close to installing substrate₁With T₂Between the time last 25% or shorter) number at place According to, can be to the measured value fit line of the function as the time；The slope of line provides the rate of change of the value of the function as the time dV/dt.In any case, hereafter, by by grinding rate divided by the rate of change of value, calculate as the characteristic monitored The rate of change dD/dV of the thickness of function, that is, dD/dV=(dD/dt)/(dV/dt).Once calculate rate of change dD/ DV, then rate of change should keep constant for product；Like products for different batches will there is no need to recalculate dD/ dV。

The most complete to install processing procedure, just can abrasive product substrate.

Optionally, the original depth d of the ground floor of at least one substrate from a collection of product substrate is measured₁(step 1202).Product substrate has at least identical with installing substrate Rotating fields, and optionally has the figure identical with installing substrate Case.In certain embodiments, and non-measured each product substrate.For example, can measure from an a batch of substrate, and Original depth can be used for the every other substrate from this batch.As another example, a substrate from box can be measured, and Original depth can be used for the every other substrate from this box.In other embodiments, each product substrate is measured.Can be in installing Before or after processing procedure completes, perform the measurement of the thickness of the ground floor to product substrate.

As it has been described above, ground floor can be dielectric medium, such as, low dielectric radio material, such as, and the silicon dioxide of doping carbon, example As, Black Diamond^TM(from Applied Materials) or Coral^TM(from Novellus Systems Inc.).Can be during removing grinding Measurement is performed at the measurement system beyond Optical Surveillance System used, such as, embedded or separating and measuring station, such as, use ellipse The contourograph of rotatory polarization instrument or optical measurement station.

Optionally, depending on the constituent of the first material, on the ground floor on product substrate deposition be different from first and One or more volume of another material of the second material (such as, low dielectric radio covers material, such as, tetraethoxysilane (TEOS)) Outer layer (step 1203).There is provided layer stack repeatedly together with one or more additional layer of ground floor and this.

It follows that deposit on the ground floor of product substrate or layer stack change different second material (such as, nitride, such as, Tantalum nitride or titanium nitride) the second layer, such as, barrier layer (step 1204).It addition, can on the second layer of product substrate (and In the groove provided by the pattern of ground floor) deposition conductive layer, such as, metal level, such as, copper (step 1205).But, should note , for some embodiments, there is not conductive layer in meaning, such as, the second layer is to grind outermost layer when starting.

For measuring technology (such as, contourograph) for some, in the initial thickness of the pre-test ground floor of the deposition second layer Degree, but for technology (such as, elliptical polarizer) is measured for other, survey can be performed before or after the deposition second layer Amount.The second layer and the deposition of conductive layer can be performed before or after installing processing procedure completes.

For the product substrate that each is to be ground, original depth based on ground floor calculates target property difference Δ V (step 1206).But generally, this measure occurred before grinding starts, but calculated likely after grinding starts in startup (in step 1210) is there is in spectral signature before following the trail of.Specifically, for example, host computer receives the product stored The original depth d of substrate₁And target thickness d_T.It addition, initial thickness D can be received₁And terminate thickness D₂, as monitor characteristic The rate of change dD/dV of thickness of function and goal-selling changes delta V of value that determines for installing substrate_D。

In one embodiment, target property difference Δ V calculated as below:

Δ V=Δ V_D+(d₁-D₁)/(dD/dV)+(D₂-d_T)/(dD/dV)

In certain embodiments, front thickness is by unavailable.In this situation, " (d1-D1)/(dD/dV) " will be from top Formula is omitted, that is,

Δ V=Δ V_D+(D₂-d_T)/(dD/dV)

Abrasive product substrate (step 1208).For example, the first grinding pad can be used at the first grinding stations, grind And remove conductive layer and portion of second layer (step 1208a).Hereafter, the second grinding pad can be used at the second grinding stations, grind Grind and remove the second layer and segments first layer (step 1208b).However, it should be noted that for some embodiments, do not exist and lead Electric layer, such as, the second layer is to grind outermost layer when starting.

Use what in-situ monitoring technology detected the removing of the second layer and ground floor to expose (step 1210) to the open air.For example, Ground floor exposing to the open air at time t1 can be detected by motor torsional moment or the sudden change of the overall strength by the light reflected from substrate.Lift For example, Figure 13 is shown in grinding metal layer during exposing lower floor's barrier layer to the open air, as the receiving from substrate of function of time The chart of the overall strength of light.Can according to by spectrum monitoring system by such as measure all wavelengths on or at preset wavelength model Place the spectral signal integrated acquired in spectral intensity, produce this overall strength.Or, it is usable in specific monochromatic wave strong point Intensity, rather than overall strength.As shown in figure 13, when removing layers of copper, overall strength declines, and when barrier layer exposes to the open air completely, the most by force Degree level off.The plateau of intensity can be detected, and the plateau of intensity can be used as triggering and chases after to start spectral signature Track.

At least start from the removing of the second layer detection (and may earlier, such as, from using the second grinding pad abrasive product base When plate starts), use above-mentioned in-situ monitoring technology to obtain spectrum (step 1212) during grinding.Above-mentioned technology is used to analyze Spectrum, to determine the value of the characteristic of tracked feature.For example, as the function of time during Figure 14 is shown in grinding The chart of the wavelength location of spectrum crest.Determine feature tracked in the spectrum at the time t1 of the removing of the detection second layer Value v of characteristic₁。

Now can desired value v of estimated performance_T(step 1214).Can add at the second layer by by target property difference Δ V The time t removed₁Value v of the characteristic at place₁, calculate desired value v_T, that is, v_T=v₁+ΔV。

When the characteristic of the feature followed the trail of reaches desired value, suspend and grind (step 1216).Specifically, each is surveyed For amount spectrum (such as, in each platform rotates), the value of the characteristic of the feature of tracking is determined, to produce series of values.As above Literary composition refers to described by Fig. 6 A, can be to series of values fitting function (such as, the linear function of time).In certain embodiments, may be used Value fitting function in time window.There is provided in the case of function meets desired value and suspend the terminal time ground.Also may be used By the partial fitting function (such as, linear function) of the series of values at time to approach t1, determine at the detection second layer The time t removed₁Value v of the characteristic at place₁。

Although being included the deposition of the second layer by Figure 12 and Figure 13 method illustrated and removing, but for some embodiments For, there is not the second layer, such as, ground floor is to grind outermost layer when starting.For example, first is measured before the grinding The original depth of layer and calculate the process of object feature value according to original depth and target thickness, is being with or without the covering second layer In the case of all can be suitable for；This second layer is optional.Specifically, step and the detection the of the deposition second layer can be omitted The step exposed to the open air of one layer.This ground floor can include polysilicon and/or dielectric material, such as, by the purest polysilicon Composition, is made up of dielectric material, or is the combination of polysilicon and dielectric material.Dielectric material can be oxide (such as, Silicon oxide), or nitride (such as, silicon nitride) or the combination of dielectric material.

For example, the original depth d of the ground floor of at least one substrate from a collection of product substrate is measured₁(such as, As discussed for step 1202).Original depth based on ground floor calculates target property difference Δ V (such as, as step Rapid 1206 are discussed).Start the grinding of the ground floor of product substrate, and use above-mentioned original position to supervise during the grinding of ground floor Spectrum is obtained depending on technology.Can during the grinding of ground floor (such as, start ground floor grinding after at once, or start After the grinding of ground floor soon (such as, after a few seconds)) value v of measurement characteristics₁.Wait several seconds for clock tolerable from supervision The signal stabilization of system so that value v₁Measurement more accurate.Can desired value v of estimated performance_T(such as, as step 1214 institute Discuss).For example, target property difference Δ V can be added to value v of characteristic₁, that is, v_T=v₁+ΔV.As tracked spy When the characteristic levied reaches desired value, suspend and grind (such as, as discussed for step 1216).The method is allowed and is removed to mesh Mark thickness, compensates simultaneously and changes between the substrate in the absolute crest site caused by difference between the substrate in understructure.

There is many technology removing noise from series of values.Although discussed above to series fit line, but also can be to Series fit nonlinear function, low pass median filter maybe can be used to smooth series (in this situation, can be by filtered value Directly compared with desired value, to determine terminal).

As this specification uses, term substrate can include that (such as) product substrate is (such as, including multiple memorizeies or place The product substrate of reason device tube core), test substrate, exposed substrate and light gate substrate.Substrate can be at each of IC manufacturing Different phase, such as, substrate can be exposed wafer, or substrate can include one or more deposition and/or patterned layer.Term base Plate can include circular discs and rectangular tab.

Embodiments of the invention and all functional operation described in this description may be implemented in Fundamental Digital Circuit, or It is implemented in computer software, firmware or hardware (including being disclosed in the structural elements in this description and structural equivalents thereof), Or be implemented in combinations thereof.Embodiments of the invention can be embodied as one or more computer program (that is, visibly It is implemented in information carrier one or more computer journey of (such as, in machine-readable storage device or in transmitting signal) Sequence), to be performed by data handling equipment (such as, programmable processor, computer or multiple processor or computer), or control The operation of data handling equipment (such as, programmable processor, computer or multiple processor or computer).Available any form Programming language (include compiling or interpretative code) write computer program (also known as program, software, software application or Code), and can (include as stand-alone program or as module, assembly, subroutine or be suitable in computing environment in any form Other unit of middle use) carry out this computer program of arrangement.Computer program need not correspond to file.Program can be stored up It is stored in the part of the file depositing other programs or data, is stored in the single file that this program is special or is stored in multiple Coordinate in file (such as, storing the file of one or more module, subprogram or partial code).Can arrangement computer program, with A computer or multiple computer of a position perform, or is scattered in multiple position and mutual by communication network Even.

Process described in this description and logic flow, can be by performing the one or many of one or more computer program Individual programmable processor performs, with by operating and produce output on the input data to perform function.Also can be patrolled by special Collect circuit (such as, field programmable gate array (FPGA) or special IC (ASIC)) to perform to process and logic flow, And equipment also can be embodied as this dedicated logic circuit.

Above-mentioned milling apparatus and method can be applicable in various grinding system.Grinding pad or carrier head or both of which can move Dynamic, to provide the relative motion between lapped face and substrate.For example, platform can be non-rotating around track operation.Grind Pad can be circular (or other shapes a certain) pad being fixedly held to platform.Some aspects of end-point detecting system are applicable to line Type grinding system, such as, wherein grinding pad be linearly moving continuously or reel is to the system of reel belt.Grinding layer can be mark Accurate (such as, being with or without the polyamine formic acid esters of filler) grinding-material, soft material or fixed abrasive materials.Use relative localization Term；Should be understood that can be by lapped face and substrate holder on vertical orientation or other orientations.

Have described that only certain embodiments of the present invention.Other embodiments are in the range of following claims.For example, may be used Perform the action of narration in claim in different order, and still can reach desired result.

Claims

1. a chemical machinery polishing system, including:

Platform, is used for holding grinding pad；

Carrier head, the substrate contacted with described grinding pad for fixing；

Optical Surveillance System in situ, is configured to measure a series of light of the light from described substrate while grinding described substrate Spectrum；And

Controller, is configured that

Receive the selected identification of spectral signature, the wave-length coverage with width and the characteristic of described selected spectral signature, to grind Monitor during mill,

Described a series of spectrum are received from described original position Optical Surveillance System,

For at least some spectrum from described a series of spectrum

Producing amendment wave-length coverage based on the position in described spectral signature previously wave-length coverage, described previous wave-length coverage is used Previous spectrum in described a series of spectrum,

Described spectral signature is searched in the described amendment wave-length coverage of described spectrum, and

Determine the value of characteristic of described selected spectrum to produce a series of values, and

Grinding endpoint is determined or at least one in the adjustment of grinding rate based on described a series of values.

2. grinding system as claimed in claim 1, it is characterised in that described wave-length coverage has fixed width.

3. grinding system as claimed in claim 2, it is characterised in that described controller is configured to pass described fixed width Center produce described amendment wave-length coverage on the described spectral signature described position in described previous wave-length coverage.

4. grinding system as claimed in claim 1, it is characterised in that described controller is configured to pass following steps and produces Described amendment wave-length coverage: determine described spectral signature position in described previous wave-length coverage；And adjust described wavelength Scope so that in described amendment wave-length coverage, described spectral signature is positioned to be closer in described amendment wave-length coverage At the heart.

5. grinding system as claimed in claim 1, it is characterised in that described controller is configured to pass following steps and produces Described amendment wave-length coverage: at least some spectrum in described a series of spectrum, determine the ripple of described selected spectral signature Long value, to produce a series of wavelength value；To described a series of wavelength value fitting functions；And calculate for follow-up according to described function The expectancy wave long value of the described selected spectral signature of spectral measurement.

6. grinding system as claimed in claim 5, it is characterised in that described function is linear function.

7. grinding system as claimed in claim 1, it is characterised in that described in-situ monitoring system is configured to measure and at least includes The spectrum of the wavelength of visible ray, and described wave-length coverage has the width between 50 and 200 nanometers.

8. grinding system as claimed in claim 1, it is characterised in that described selected spectral signature includes spectrum crest, spectrum Trough or spectrum zero-crossing.

9. grinding system as claimed in claim 8, it is characterised in that described characteristic includes wavelength, width or intensity.

10. grinding system as claimed in claim 9, it is characterised in that described selected spectral signature includes spectrum crest, and Described characteristic includes the wavelength of described crest.

11. 1 kinds of chemical machinery polishing systems, including:

Platform, is used for holding grinding pad；

Carrier head, the substrate contacted with described grinding pad for fixing；

Controller, is configured that

Receive identification and the characteristic of described selected spectral signature of selected spectral signature, to monitor during grinding,

Receiving the user input selecting fixed wave length scope, described fixed wave length scope is by the ripple of in-situ monitoring systematic survey Long subset；

A series of spectrum of described light are received from described in-situ monitoring system,

For each spectrum in described a series of spectrum, search described in the range of the described fixed wave length of each spectrum described Selected spectral signature, and determine the value of the characteristic of described selected spectral signature, to produce a series of value；And

12. grinding systems as claimed in claim 11, it is characterised in that described in-situ monitoring system is configured to measure at least wraps Include the spectrum of the wavelength of visible ray, and described wave-length coverage has the width between 50 and 200 nanometers.

13. 1 kinds of chemical machinery polishing systems, including:

Platform, is used for holding grinding pad；

Carrier head, the substrate contacted with described grinding pad for fixing；

Controller, is configured that

A series of spectrum of described light are received from described original position Optical Surveillance System,

The time that ground floor on the substrate exposes to the open air, determine the first value of the described characteristic of described feature；

Skew is added to described first value, to produce the second value；

For each spectrum in described a series of spectrum, it is determined by the value of described characteristic to produce a series of values to monitor State the described characteristic of feature；And

Grind determining to suspend when the value of described characteristic of described feature reaches described second value.

14. grinding systems as claimed in claim 13, it is characterised in that described controller is configured to from described original position A series of spectrum of the described light of Optical Surveillance System detect exposing to the open air of described ground floor.

15. grinding systems as claimed in claim 14, it is characterised in that described controller is configured to pass supervision from described Total reflex strength of substrate detects exposing to the open air of described ground floor.

16. grinding systems as claimed in claim 13, it is characterised in that described grinding system includes another in-situ monitoring system Unite to detect exposing to the open air of described ground floor.

17. grinding systems as claimed in claim 16, it is characterised in that another in-situ monitoring system described includes that motor is turned round Square or friction monitoring system.

18. grinding systems as claimed in claim 13, it is characterised in that described controller is configured to receive described ground floor Thickness before grinding, and deviant described in THICKNESS CALCULATION before described grinding.

19. grinding systems as claimed in claim 18, it is characterised in that described controller is configured to pass calculating (D₂-d_T)/ (dD/dV) described offset value delta V, wherein d are calculated_TFor target thickness, D1 is before the grinding of the ground floor of installing substrate Thickness, D₂For thickness after the grinding of the described ground floor from installing substrate, and dD/dV is the thickness of the function as described characteristic The speed of degree change.

20. grinding systems as claimed in claim 18, it is characterised in that described controller is configured to pass calculating below equation Calculate described offset value delta V:

Δ V=Δ V_D+(d₁-D₁)/(dD/dV)+(D₂-d_T)/(dD/dV)

Wherein d₁For thickness, d before described grinding_TFor target thickness, D1 is thickness before the grinding of the ground floor of installing substrate, D2 is thickness after the grinding of the described ground floor of installing substrate, Δ V_DDescribed grinding for the described ground floor of installing substrate Difference in the described value of the described characteristic of feature between thickness after front thickness and described grinding, and dD/dV is as described spy Property function thickness change speed.

21. grinding systems as claimed in claim 13, it is characterised in that described spectral signature includes the crest in described spectrum Or trough.

22. grinding systems as claimed in claim 21, it is characterised in that described characteristic includes the described crest in described spectrum Or the position of trough, width or intensity.