JP2002001652A - Polishing pad and apparatus, and manufacturing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polishing pad capable of improving the S/N ratio of reflected signal light, a polishing apparatus comprising the polishing pad, and a method for manufacturing a semiconductor device comprising a step of polishing with the polishing apparatus, in order to improve the accuracy of optical measurement of a polishing condition which is carried out at the polishing of a substrate by applying a load in a state with a polishing agent interposed between the load and the substrate and relatively moving the substrate. SOLUTION: The polishing pad comprises one light transmitting window or more for transmitting light for optically measuring the polishing condition, window groove parts close to the light transmitting window having a function for preventing the polishing agent from reaching upper surface of the light transmitting window, or a function for promoting discharge of the polishing agent on the upper surface of the light transmitting window, and grooves in all or a part of the region of the surface of the polishing pad except the region of the light transmitting window and the window groove parts.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a substrate, for example, a UL
Polishing pad suitably used for planarization polishing (CMP) of a semiconductor device substrate performed in a process of manufacturing a semiconductor device such as SI, a polishing apparatus having the main polishing pad, and a semiconductor device using the main polishing apparatus. The present invention relates to a device manufacturing method.

[0002]

2. Description of the Related Art As the density of semiconductor devices increases,
The importance of the technology of multilayer wiring and the accompanying formation of interlayer insulating films and the formation of electrodes such as plugs and damascenes is increasing.
Accordingly, the importance of the planarization process of the interlayer insulating film and the metal film of the electrode is increasing, and a polishing process called CMP is an efficient technique for the planarization process.

[0003] CMP (Chemical Mechanical Polishing or Planarization) has a chemical action (
This is a step of removing irregularities of the thin film on the wafer surface by using in combination with (dissolution by an abrasive solution). By uniformizing the pressure and the relative movement speed over the entire surface of the wafer, the inside of the wafer is uniformly polished.

Here, in order to correctly embed a plug, a damascene or the like, the importance of accurate detection of the polishing end point is increasing, and for this detection, an optical measuring method is required due to its high accuracy. Has been noted. For example, JP-A-11-3
According to the technology disclosed in Japanese Patent No. 3901, not only a blank film but also a wafer having a device pattern (base pattern) and a wafer having a two-dimensionally non-uniform pattern, The film thickness or polishing end point can be measured on the spot.

FIG. 5 shows a polishing apparatus for explaining a conventional optical measuring method. In FIG. 5, 101 is a polishing head, 102 is a wafer to be polished, 103 is a polishing pad, 104 is a surface plate, 105 is a light transmitting window, and a transparent member is fitted into the polishing pad 103. 106 is a light source and light detection unit, 107 is a signal processing unit, 108 is a display unit,
09 is an abrasive supply device, 110 is an abrasive, and 115 is a hole formed in the surface plate. As the polishing pad 103, there are one using a foamed resin and one using a non-foamed resin. In order to supply an abrasive to the entire processing surface and further discharge polishing scum generated by polishing out of the polishing pad, Has a groove. Attach the wafer 102 to the polishing head 101,
The surface to be polished of the wafer 102 is pressed against the processing surface of the polishing pad 103 while rotating (W _H ). At the same time, the surface plate 10
The polishing pad 103 fixed to 4 is rotated (W _T ),
Polishing is performed by supplying a relative motion between the wafer 102 and the polishing agent 110 in this state by supplying the polishing agent 110 from the polishing agent supply mechanism 109 between the surface to be polished and the processing surface.

During this time, in order to measure a polishing state, light 116 emitted from a light source and a light detecting unit 106 is irradiated on a surface to be polished of the wafer 102 through a hole 115 and a light transmitting window 105.
The reflected light therefrom is again received by the light source and the light detection unit 106 through the light transmitting window 105 and the hole 115. Based on the change in the received light signal, the polishing state such as the polishing end point or the remaining film thickness is measured.

[0007]

However, in the conventional end point measurement, the measurement accuracy of the polished state may be low. The present inventors have investigated the cause and found that the cause is that the received optical signal may be unstable. That is, the magnitude or shape of the optical signal may change independently of the progress of polishing. Since this change acts as noise especially on the optical signal,
The measurement accuracy was deteriorated.

The present inventors have investigated the causes of the above instability and found that the main cause is that light penetrates through a layer of abrasive having a non-negligible layer thickness. As shown in FIG. 6 which is an enlarged cross-sectional view near the light transmitting window 105 in FIG. 5, the transparent member 105 fitted as the light transmitting window 105 is provided.
Between the upper surface of the wafer and the surface to be polished of the wafer 102
05 and the space surrounded by the wafer (hereinafter simply called space)
There are 111. Irradiation light to wafer 102 and wafer 102
Is transmitted through the space 111. Space 11
1 is filled with a slurry 110 to form a slurry layer, and the thickness of the slurry layer depends on the size of the interval 112 of the space 111. In order to prevent the surface of the polished surface of the wafer or the upper surface of the transparent member 105 from being damaged by the contact of the wafer 102 with the transparent member 105, the distance 112 is kept to a required value or more. However, the space 111 is filled with the slurry 110 depending on the gap 112, and the layer of the slurry not only absorbs light (irradiation light or reflected light) but also scatters. The larger the thickness of the slurry layer, the larger the amount of absorbed light and the amount of scattered light, and the amount of reflected signal light decreases. Further, the scattered light affects the reflected signal light as noise light. As described above, as the slurry layer becomes thicker, noise light increases and signal light decreases, so that the S / N ratio of reflected signal light generally decreases.

Further, the thickness of the slurry layer fluctuates with fluctuations in centrifugal force due to fluctuations in the rotational speed W _T of the polishing pad, fluctuations in the amount of slurry supplied, and the like. Further, as the polishing proceeds, the components of the slurry fluctuate due to the dissolution of the film and the like, and the optical characteristics and the like of the slurry fluctuate. Furthermore, the gap 112 between the transparent member and the wafer fluctuates due to the elastic vibration of the polishing pad or the wafer, the wear of the polishing pad, or the like, and the layer thickness of the slurry fluctuates accordingly. Due to the above fluctuations,
The S / N ratio of the reflected signal light fluctuates, and the fluctuation width of the S / N ratio increases as the thickness of the slurry layer increases. The change in the S / N ratio eventually lowers the S / N ratio of the reflected signal light.

The decrease in the S / N ratio due to the solid slurry layer described above lowers the measurement accuracy of the polishing end point. From the above discussion, it can be seen that the greater the thickness of the slurry layer, the greater the degree of deterioration of the measurement accuracy.

Therefore, in order to measure the polishing end point with high accuracy, it is understood that it is preferable to minimize the thickness of the slurry layer in a portion where the irradiation light and the reflected light of the light transmitting window are transmitted.

As described above, an object of the present invention is to make it possible to extremely reduce the thickness of a slurry layer in a portion where irradiation light and reflected signal light of a light transmitting window are transmitted, and as a result, a polishing end point can be measured with high accuracy. Polishing pad, and a polishing apparatus comprising the polishing pad, capable of polishing the polishing state with high precision, and a step of polishing a semiconductor device wafer surface with the polishing apparatus. It is an object to provide a manufacturing method.

[0013]

In order to solve the above-mentioned problems, in the present invention, first, a load is applied in a state where an abrasive is interposed between the substrate and the substrate, and the substrate is relatively moved. A polishing pad for polishing a substrate, wherein the polishing pad has at least one light-transmitting window for transmitting light for optically measuring a polishing state, and a window near the light-transmitting window. A groove, and a groove in the whole or a part of a region excluding a region of the light transmitting window and the window groove from a region of the polishing pad surface, and the light transmitting window, the window groove and the groove are polished. A polishing pad is provided which has a function of preventing an agent from reaching the upper surface of the light transmitting window or a function of promoting discharge of the abrasive from the upper surface of the light transmitting window.

The light transmitting window, the window groove and the groove of the polishing pad of the present invention work together to prevent the abrasive from reaching the light transmitting window (first function) or the light transmitting window. It is configured to have a function (second function) to promote the discharge of the above abrasive, so that the average layer thickness of the abrasive on the light-transmitting window becomes thin, so that the polishing end point can be measured with high accuracy. Can be.

[0015] Secondly, the polishing pad according to claim 1, wherein the window groove portion is formed close to the periphery of the light transmitting window. Since the window groove portion of the present invention is formed close to the light transmitting window, the first function works as follows. That is, the abrasive flowing toward the light-transmitting window through one groove flows into the window groove, flows through the window groove, and then flows out to the other groove of the window groove. As the abrasive flows as described above, the amount of the abrasive flowing on the window decreases, and the amount of the abrasive existing on the window decreases. The second function works as follows. That is, even if the abrasive flows into the upper surface of the light-transmitting window, since the gap between the upper surface of the light-transmitting window and the lower surface of the substrate (processed surface of the polishing pad) is appropriately maintained, the abrasive is Due to the centrifugal force and other forces acting on the
It falls into the window groove, flows out of the window groove and is discharged, and the upper surface of the light transmitting window does not flood.

The first and second functions enable the thickness of the abrasive layer on the light transmitting window to be extremely reduced. The light-transmitting window refers to a portion provided on a polishing pad or a surface plate, which transmits irradiation light and reflected light. As an example, when the light transmitting window is configured as a transparent member fitted into a polishing pad, the light transmitting window corresponds to the transparent member.

Thirdly, the gap a between the upper surface of the light-transmitting window and the processing surface of the polishing pad removes the abrasive on the surface of the light-transmitting window by centrifugal force caused by rotation of the polishing pad during polishing. The polishing pad according to any one of claims 1 and 2, wherein the polishing pad is sized.

A fourth aspect of the present invention is to provide the polishing pad according to the third aspect, wherein a depth b of the bottom surface of the groove from the processing surface of the polishing pad satisfies b ≧ a. Fifth, the polishing pad according to any one of claims 2 to 4, wherein the shape of the light-transmitting window is streamlined in a direction opposite to a direction in which the centrifugal force acts. I will provide a.

Sixth, the polishing pad according to any one of claims 1 to 5 and a measuring device for optically measuring a polishing state are provided, and an abrasive is interposed between the polishing pad and the substrate. In the state, the substrate is polished by applying a load between the substrate and the polishing pad, and relatively moving the substrate and the polishing pad, and irradiating the substrate with light, The present invention provides a polishing apparatus characterized by optically measuring a polishing state of the polishing apparatus.

A seventh aspect of the present invention provides a method for manufacturing an element, comprising a step of polishing a surface using a polishing apparatus according to claim 6.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [Embodiment 1] FIG. 3 is a schematic view of a polishing apparatus for explaining the present embodiment, and FIGS. 1 and 2 are enlarged schematic views in the vicinity of a light transmitting window 5 in FIG. is there. FIG. 1 is a plan view, and FIG. 2 is a cross-sectional view taken along AA ′ of FIG. 1 and 2, 2 is a wafer, 3 is a polishing pad, 19 is a groove formed on a processing surface of the polishing pad 3, 4 is a platen, 5 is a transparent member as a light transmitting window, and 15 is a platen. It is a hole drilled in. Here, the translucent window 5 includes a composite structure and a movable window. In addition, as the polishing pad, not only a structure in which the light-transmitting window and the remaining portion of the polishing pad are integrated in a single state not attached to the polishing device, but also a state in which the polishing window is attached to the polishing device. Including those that are integrated for the first time. As the groove 19, a lattice groove having a V-shaped or trapezoidal cross section is formed. A window groove 14 is provided around the transparent member 5. The groove of the window groove 14 is made wider or deeper as the supply amount of the slurry is larger in order to prevent the slurry from overflowing from the window groove.
Further, the planar shape of the window groove portion 14 is such that the slurry easily flows from the groove portion 19 into the window groove portion 14 by centrifugal force.
Or, it is preferable that the slurry is formed so that the slurry easily flows through the window groove portion 14 or that the slurry easily flows out from the window groove portion 14 into the groove portion 19. For this reason, it is particularly preferable that the shape of the window groove or the light transmitting window be streamlined in the direction opposite to the direction in which the centrifugal force acts. One example of this streamline type is shown by a shape example of FIG. In this case, since the window groove 14 is preferably provided close to the light-transmitting window, the shape of the window groove is also preferably streamlined. In this figure, the window groove portion 14 is provided on the entire circumference of the light transmitting window 5, but may be provided on a partial circumference instead of the entire circumference as necessary, and further provided at a position crossing the light transmitting window 5. The arrangement method of the window groove is not particularly limited as long as it is in the vicinity of the light transmitting window. In FIG. 2, the thickness of the light-transmitting window 5 is equal to the thickness of the polishing pad. However, the light-transmitting window may have a structure extending to a portion corresponding to the hole of the surface plate. Disappears. Further, as the polishing pad, a single-layer structure or a multi-layer structure, or foamable or non-foamable, or soft or hard, or those having the first platen at the bottom or those without, Alternatively, there are various forms such as a combination thereof. In both cases, polishing is performed in a state in which the substrate is fixed to a second surface plate (hereinafter, simply referred to as a surface plate). 10 is the slurry existing in the window groove 14 while flowing, 17 is the slurry flow in the window groove, 20 is the slurry flow in the groove, 18 is the rotation axis of the polishing pad, and 31 is the centrifugal force acting on the slurry. Is the working direction. Reference numeral 12 denotes a distance a between the upper surface of the light transmitting window 5 and the processing surface of the polishing pad 3, and reference numeral 13 denotes a depth b of the bottom surface of the groove of the polishing pad 3 from the processing surface of the polishing pad 3.

The operation will be described below. In the polishing apparatus shown in FIG. 3, the wafer 2 is mounted on the polishing head 1 and rotated (W).
_H ) While polishing, the surface to be polished of the wafer 2 is pressed against the processing surface of the polishing pad 3. At the same time, the polishing pad 3 fixed to the surface plate 4 is rotated (W _T ) to give a relative movement between the polishing pad 3 and the wafer 2. Polishing is performed by supplying between the surface.

In the meantime, in order to measure the polishing end point, the light 16 emitted from the light source and the light detecting unit 6 is transmitted through the hole 15 and the light transmitting window 5.
Then, the light is radiated to the surface to be polished of the wafer 2, and the reflected light therefrom is again received by the light source and the light detector 6 through the light transmitting window 5 and the hole 15. The polishing end point or the remaining film thickness is measured based on the change in the received light signal.

The operation around this is the same as that of the conventional polishing apparatus, so that detailed description is omitted to avoid redundancy.
The present invention is characterized by the structure near the light transmitting window. When the polishing apparatus of FIG. 3 starts operation, the slurry 10 supplied from the polishing agent supply mechanism 9 of FIG. 3 is supplied by the relative motion between the wafer 2 and the polishing pad 3 or by the rotation (W _T ) of the polishing pad 3. Polishing pad 3 by centrifugal force acting on 10
Over the entire groove formed on the entire machined surface of. A part of the slurry 10 flowing through the groove 19 is directed to the light transmitting window 5. 1 and 2, the slurry 20 flowing toward the light transmitting window 5 through the groove 19 due to the relative movement of the polishing pad or the centrifugal force 31 flows from the groove 19 into the window groove 14 at the inflow point 21. The flowing slurry flows along the window groove 14 in the direction indicated by the arrow 17 by the action of the centrifugal force 31, and finally flows out of the window groove 14 into the groove 19 at the outflow point 22. Here, in order to prevent or prevent the upper surface of the light transmitting window 5 from being flooded by the slurry, or to easily discharge the slurry reaching the upper surface of the light transmitting window 5 to the groove 19. Preferably, the depth b of the bottom surface of the polishing pad groove from the polishing pad processing surface is equal to or larger than the distance a between the upper surface of the light transmitting window 5 and the polishing pad processing surface, that is, b ≧ a. In this way, before the slurry is filled up to the upper surface of the light transmitting window 5, the slurry is discharged by this groove portion, and it is possible to prevent water from entering by the slurry on the upper surface of the light transmitting window 5. Further, in order to prevent the slurry from overflowing from the inside of the window groove 14 toward the light transmitting window 5 or to prevent the slurry from overflowing, the width of the window groove 14 is determined according to the rotation speed of the polishing pad and the amount of slurry supplied. Alternatively, the depth is preferably adjusted. In this way, the amount of slurry reaching the light transmitting window 5 is reduced.

Further, the distance between the upper surface of the light transmitting window and the polishing pad processing surface (ie, the surface to be polished of the wafer) is determined by the centrifugal force 31 acting on the slurry on the light transmitting window 5 and the upper surface of the light transmitting window and the wafer surface. It is kept wide enough to overcome the forces of interaction with the polished surface. In order to further reduce the force of this interaction,
Make the translucent window 14 water-repellent or use a water-repellent film
It is also preferable to form it. By doing as described above, even if the slurry reaches the translucent window 5, the slurry can smoothly move toward the outside of the translucent window, and as a result, the slurry returns to the window groove 14 again. Depression, window groove 14
Flows under the force of centrifugal force 31, etc.
Is discharged from

As described above, the amount of slurry reaching the upper surface of the light-transmitting window 5 can be reduced, and when the slurry reaches the upper surface of the light-transmitting window 5, it is smoothly removed outward. Therefore, the amount of slurry existing on the upper surface of the light transmitting window 5 can be greatly reduced, and as a result, the thickness of the slurry layer on the upper surface of the light transmitting window 5 can be greatly reduced.

As described above, the thickness of the slurry layer on the upper surface of the light transmitting window is extremely thinner than that of the conventional example. As a result, when the wafer 16 is irradiated with the light 16 for measurement by the polishing apparatus of FIG.
The amount of light scattered and the amount of light scattered when transmitted through the slurry layer twice, once when reflected from the wafer 2 once, can be greatly reduced. As a result, noise light is greatly reduced and the size of the reflected signal light is increased, so that the S / N ratio of the reflected signal light can be improved. In addition, as the thickness of the slurry layer becomes thinner, the effect of fluctuations in the optical properties of the slurry due to fluctuations in the slurry components due to the melting of the film due to the progress of polishing reduces the magnitude of the effect on the reflected signal light. Accordingly, the S / N ratio of the reflected signal light is improved.

According to the present invention, the reflected signal light whose S / N ratio has been improved as described above is received by the light detecting section 6, and a minute change in the reflected signal light is detected with high accuracy and reliability by the signal processing section 7. Therefore, when polishing a thin film on a wafer, the polishing end point or the remaining film thickness can be measured with high accuracy. [Embodiment 2] This embodiment relates to a method for manufacturing a semiconductor device using the polishing apparatus of the present invention.

FIG. 4 is a flowchart showing a semiconductor device manufacturing process. After the semiconductor device manufacturing process is started, first, in step S200, an appropriate processing step is selected from the following steps S201 to S204. Steps S201 to S204 according to the selection
Proceed to one of

Step S201 is an oxidation step for oxidizing the surface of the silicon wafer. Step S202 is CV
D to form an insulating film on the silicon wafer surface
This is a VD process. Step S203 is an electrode film forming step of forming an electrode film on a silicon wafer by a process such as vapor deposition. Step S204 is an ion implantation step of implanting ions into the silicon wafer.

After the CVD process or the electrode film forming process, the process proceeds to step S209, and it is determined whether a CMP process is performed. If not, the process proceeds to step S206; otherwise, the process proceeds to step S205. Step S2
Reference numeral 05 denotes a CMP step, in which a polishing apparatus of the present invention is used to planarize an interlayer insulating film and to form a damascene by polishing a metal film on the surface of a semiconductor device.

After the CMP step or the oxidation step, the process proceeds to step S206. Step S206 is a photolithography step. In the photolithography process, a resist is applied to a silicon wafer, a circuit pattern is printed on the silicon wafer by exposure using an exposure device, and the exposed silicon wafer is developed. Further, in the next step S207, portions other than the developed resist image are removed by etching.
Thereafter, the resist is stripped, and the etching step is performed to remove the unnecessary resist after the etching.

Next, in step S208, it is determined whether all necessary processes have been completed. If not, step S20
Returning to 0, the described steps are repeated to form a circuit pattern on the silicon wafer. Step S208
If it is determined that all the steps have been completed, the process ends.

In the semiconductor device manufacturing method according to the present invention, since the polishing apparatus according to the present invention is used in the CMP step, the accuracy of detecting the polishing end point in the CMP step is improved, and the yield in the CMP step is reduced. improves.
As a result, there is an effect that a semiconductor device can be manufactured at a lower cost than a conventional semiconductor device manufacturing method.

The CMP process using the polishing apparatus of the present invention can be used for other semiconductor device manufacturing processes other than the semiconductor device manufacturing process shown in FIG.
Alternatively, it can be used for a manufacturing process of another element.

The semiconductor device according to the present invention is manufactured by the semiconductor device manufacturing method according to the present invention. As a result, a semiconductor device can be manufactured with higher quality and at lower cost than the conventional semiconductor device manufacturing method, and the manufacturing cost of the semiconductor device can be reduced.

As described above, the embodiments 1 and 2 have been described with reference to the drawings. However, the scope of the present invention is not limited to the ranges shown in these drawings, and the present invention is not limited to the above description. It is not limited to.

[0038]

According to the present invention, the light transmitting window, the window groove and the groove cooperate to prevent the abrasive from reaching the upper surface of the light transmitting window or the polishing on the upper surface of the light transmitting window. Since it is configured to have a function to promote the discharge of the polishing agent, the signal layer is scattered by the slurry layer during optical measurement during polishing of the wafer because the average layer thickness of the polishing agent on the light transmitting window is reduced. Alternatively, since absorption or fluctuation is reduced, the S / S
The N ratio is increased, and the polishing state and the like can be optically measured with high precision. [Claim 2] In the present invention, in addition to the effect of claim 1, since the window groove is formed close to the light-transmitting window,
Since the slurry on the upper surface of the light transmitting window is easily discharged, optical measurement can be performed with higher accuracy. [Claim 3] In the present invention, in addition to the effects of claims 1 and 2,
Since the gap a between the upper surface of the light-transmitting window and the processing surface of the polishing pad is so large that the abrasive on the surface of the light-transmitting window can be removed by centrifugal force due to rotation during polishing of the polishing pad, the slurry a Since the working centrifugal force overcomes the interaction between the slurry and the surface and the slurry is removed smoothly, it is possible to perform optical measurement with higher precision. [Claim 4] In the present invention, in addition to the effects of Claims 1, 2 and 3, if the depth of the bottom surface of the groove from the processing surface of the polishing pad is b, b ≧ a is satisfied. Since the slurry on the upper surface of the light window is easily discharged into the groove and the upper surface of the light transmitting window can be prevented from being immersed, the optical measurement can be performed with higher precision. [Claim 5] In the present invention, since the shape of the light-transmitting window is streamlined in the direction opposite to the direction in which the centrifugal force acts, the slurry smoothly moves in the centrifugal force direction along the window groove. Since the slurry flows, the slurry can be efficiently discharged toward the groove, and the optical measurement can be performed with higher accuracy. [6] In the present invention, a polishing pad according to any one of [1] to [5] and a measurement for optically measuring a polishing state such as a polishing end point or a remaining film thickness from signal light passing through the polishing pad. Since the apparatus is provided with the apparatus, the polishing state such as the polishing end point is optically measured with high precision during the polishing of the substrate. [Claim 7] According to the present invention, since a surface is polished by using the polishing apparatus according to claim 6, elements such as semiconductor devices can be manufactured with high quality and high yield.

[Brief description of the drawings]

FIG. 1 is a plan view near a light-transmitting window of the present invention.

FIG. 2 is a cross-sectional view of the vicinity of a light transmitting window of the present invention.

FIG. 3 shows a polishing apparatus according to the present invention.

FIG. 4 is a flowchart of an example of a semiconductor device manufacturing process.

FIG. 5 is a conventional polishing apparatus.

FIG. 6 is a cross-sectional view near a light-transmitting window of a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1, 101 Polishing head 2, 102 Substrate (wafer) 3, 103 Polishing pad 4, 104 Surface plate 5, 105 Translucent window (transparent member) 6, 106 Light source and light detection part 7, 107 Signal processing part 8, 108 Display Unit 9, 109 Abrasive supply device 10, 110 Abrasive (slurry) 12 Interval a between upper surface of light-transmitting window and polishing pad processing surface a 13 Depth b of polishing pad groove bottom surface from polishing pad processing surface b 14 Window groove 15, 115 Holes 16, 116 Irradiation light and reflected light 17 Flow of abrasive (slurry) in window groove 18 Rotation axis of polishing pad 19 Groove 20 Flow of abrasive (slurry) in groove 21 Inflow point 22 Outflow point 31 Centrifugal shows the rotation of the spacing W _T polishing pad of the force and the space 112 transparent member top and the polished surface of the wafer enclosed in the working direction 111 polished surface of the transparent member top surface and the wafer with it Shows the rotation of _H polishing head

Claims (7)

[Claims] 1. A polishing pad for polishing a substrate by applying a load with a polishing agent interposed between the substrate and the substrate by relatively moving the substrate, wherein the polishing pad is in a polishing state. One or more light-transmitting windows for transmitting light for optically measuring, a window groove near the light-transmitting window, and the light-transmitting window and the window groove from a region of the polishing pad surface. A groove portion in the whole or a part of the region excluding the region, wherein the light-transmitting window, the window groove portion, and the groove portion function to prevent an abrasive from reaching the upper surface of the light-transmitting window or the light-transmitting portion. A polishing pad characterized by having a function of promoting discharge of an abrasive on a window upper surface. 2. The polishing pad according to claim 1, wherein said window groove is formed close to said light transmitting window. 3. A gap a between an upper surface of the light-transmitting window and a processing surface of the polishing pad is large enough to remove an abrasive on the surface of the light-transmitting window by centrifugal force caused by rotation of the polishing pad during polishing. The polishing pad according to any one of claims 1 and 2, characterized in that: 4. The polishing pad according to claim 3, wherein b ≧ a, where b is the depth of the bottom surface of the groove from the processing surface of the polishing pad. 5. The polishing pad according to claim 2, wherein the shape of the light transmitting window is streamlined in a direction opposite to a direction in which the centrifugal force acts. . 6. A polishing pad comprising a polishing pad according to claim 1 and a measuring device for optically measuring a polishing state, wherein a polishing agent is interposed between said polishing pad and a substrate. ,
A load is applied between the substrate and the polishing pad, and the substrate is polished by relatively moving the substrate and the polishing pad, and the substrate is polished by irradiating the substrate with light. A polishing apparatus characterized by performing optical measurement. 7. A method for manufacturing an element, comprising a step of polishing a surface by using the polishing apparatus according to claim 6.