Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
  • H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
  • H01L21/68—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for positioning, orientation or alignment
  • H01L21/681—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for positioning, orientation or alignment using optical controlling means
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
  • G01B11/00—Measuring arrangements characterised by the use of optical techniques
  • G01B11/26—Measuring arrangements characterised by the use of optical techniques for measuring angles or tapers; for testing the alignment of axes
  • G01B11/27—Measuring arrangements characterised by the use of optical techniques for measuring angles or tapers; for testing the alignment of axes for testing the alignment of axes
  • G01B11/272—Measuring arrangements characterised by the use of optical techniques for measuring angles or tapers; for testing the alignment of axes for testing the alignment of axes using photoelectric detection means
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F9/00—Registration or positioning of originals, masks, frames, photographic sheets or textured or patterned surfaces, e.g. automatically
  • G03F9/70—Registration or positioning of originals, masks, frames, photographic sheets or textured or patterned surfaces, e.g. automatically for microlithography
  • G03F9/7003—Alignment type or strategy, e.g. leveling, global alignment
  • G03F9/7007—Alignment other than original with workpiece
  • G03F9/7011—Pre-exposure scan; original with original holder alignment; Prealignment, i.e. workpiece with workpiece holder
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
  • H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
  • H01L21/67005—Apparatus not specifically provided for elsewhere
  • H01L21/67011—Apparatus for manufacture or treatment
  • H01L21/67092—Apparatus for mechanical treatment
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
  • H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
  • H01L21/67005—Apparatus not specifically provided for elsewhere
  • H01L21/67242—Apparatus for monitoring, sorting or marking
  • H01L21/67259—Position monitoring, e.g. misposition detection or presence detection
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L23/00—Details of semiconductor or other solid state devices
  • H01L23/544—Marks applied to semiconductor devices or parts, e.g. registration marks, alignment structures, wafer maps
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
  • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
  • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
  • H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
  • H01L21/185—Joining of semiconductor bodies for junction formation
  • H01L21/187—Joining of semiconductor bodies for junction formation by direct bonding
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L2223/00—Details relating to semiconductor or other solid state devices covered by the group H01L23/00
  • H01L2223/544—Marks applied to semiconductor devices or parts
  • H01L2223/54426—Marks applied to semiconductor devices or parts for alignment

Definitions

• the invention relates to a method and a device for aligning substrates according to the independent claims.
• microcontrollers for example, microcontrollers, memory modules, MEMS, all types of sensors or microfluidic components.
• Permanent bonding is understood to mean all processes with the aid of which substrates can be connected to one another in such a way that their separation is only possible through the use of high energy and the associated destruction of the substrates.
• permanent bonding There are different types of permanent bonding which are known to the person skilled in the art.
• Fusion bonding is the process of permanently connecting two substrates through the formation of covalent bonds. Fusion bonds arise primarily on the surfaces of non-metallic-non-organic materials. Fusion bonds can take place in several process steps: the pretreated, cleaned substrates are connected to one another by means of so-called prebonds. In the prebond process, two substrates are bonded to one another solely by van der Waals forces. This bonding process takes place primarily between silicon substrates and / or silicon oxide substrates. The bonding process connects a first to be bonded Substrate surface of a first substrate with a second substrate surface to be bonded of a second substrate.
• the binding energy of the weak link is sufficient to ensure that the substrates are immovably connected to one another.
• the prebond enables a non-destructive, in particular damage-free, separation of the substrates that are joined to one another. Only after a heat treatment is the prebond converted into an inseparable bond between the substrates.
• the substrates aligned with one another can, if necessary, be clamped first or purely mechanically after the prebond.
• the substrates are preferably clamped to one another using a method described in patent specification PCT / EP2013 / 056620.
• Magnetically acting fixing means are used for the quick and easy fixing of the two substrates that are aligned and brought into contact with one another.
• the clamping can also be done in any other way.
• the mutually aligned substrates can be clamped to a sample holder.
• the prior art knows innumerable methods for measuring alignment marks for the correct positioning of the substrates on which the alignment marks are located, as well as for the subsequent bonding step.
• substrates are aligned with one another with the aid of alignment systems, in particular in accordance with US6214692B1, WO2014202106A1 or WO2015082020A1.
• the alignment system of the document US6214692B 1 can be regarded as the closest prior art.
• two groups of optics, each with two optics facing each other are used to create a system with two reference points, the substrates being positioned alternately with respect to the system.
• the reference points are the Points of intersection of the optical axes of two opposing optics.
• an optical system and a rotation system are used for the substrate positioning according to the principle of reversal adjustment, see Hansen, Friedrich: Adjustment, VEB Verlagtechnik, 1964, Paragraph 6.2.4, Umschlagmaschine, in which at least one measurement in a defined position and at least one measurement is carried out in a 180 degree rotated, oppositely oriented, reversed position.
• the measurement result obtained in this way is especially cleared of eccentricity errors.
• a problem with the alignment of at least two substrates is that the movement sequences of the alignment are always faster but also more and more precise, that is to say with less
• Residual position uncertainty should run so that the substrates are connected and connected to one another in the ideal position as far as possible. These movement demands are in opposition to each other.
• Structural additional paths are trajectories of a first substrate to be bonded with a second substrate to be bonded, which are omitted by optimizing the device while maintaining the alignment functionality of the device and in particular by increasing the positioning accuracy.
• the loading and unloading directions are usually identical to the main direction of movement Orientation of the substrates.
• both substrates travel a length corresponding to the entire substrate diameter several times.
• the design of alignment devices is based on the historically developed design of a manual
• the loading and unloading direction is transverse to the main direction of movement for aligning the substrates. Short travels are possible to detect the alignment marks.
• the positioning of the two double microscopes is essentially identical to the structure of conventional alignment devices.
• the PCT7EP2016 / 070289 uses additional alignment features of the substrate holder that are combined with the substrate features and allow for more precise alignment.
• the mechanical structure is designed essentially in accordance with the conventional alignment devices.
• parasitic movements listed are known to those skilled in the field of mechanical engineering and mechatronics.
• parasitic movements affect the alignment success if they represent a systematic error for the alignment.
• the image acquisition elements of the devices of the prior art in particular double microscopes, which can acquire a focal plane in the opposite direction, are located at the end of open ones Consoles.
• the image acquisition is thus attached to machine frames of a so-called open C design.
• Open C designs tend to vibrate, which, especially in the low-frequency range between 0.1 Hz to 1 Hz or between 0.1 Hz to 10 Hz, can only be damped and not eliminated with considerable structural effort.
• a method for aligning substrates whereby alignment marks are detected and the substrates are aligned with one another as a function of the detection of the alignment marks, with at least two alignment marks being arranged in alignment with a linear movement of the substrates.
• the invention also provides a device for aligning substrates and for carrying out the method according to the invention, whereby alignment marks can be detected, and the substrates can be aligned with one another as a function of the detection of the alignment marks, with at least two alignment marks being arranged in alignment with a linear movement of the substrates .
• At least three alignment marks are arranged in alignment with the linear movement of the substrates.
• At least one alignment mark is arranged on and / or on a substrate holder.
• At least two alignment marks are arranged on a substrate and at least one alignment mark is arranged on the substrate holder, the alignment marks being arranged in alignment with the linear movement of the substrates.
• detection units for detecting the alignment marks are arranged in at least one ring-shaped measuring portal, preferably in at least one completely closed ring-shaped measuring portal.
• detection units for detecting the alignment marks are arranged in two ring-shaped measuring portals, preferably in two completely closed ring-shaped measuring portals.
• detection units for detecting the alignment marks are arranged in an annular measuring portal, preferably in a completely closed annular measuring portal, and in a C-shaped column. It is preferably provided that the alignment takes place along a single alignment axis, the alignment axis running parallel to the loading and unloading direction of the substrates.
• At least two alignment marks are arranged in alignment with the linear movement of the substrates.
• These exemplary configurations apply both to the first / upper substrate or the first / upper substrate holder and to the second / lower substrate or the second / lower substrate holder.
• at least two alignment marks are arranged in alignment with the linear movement of the substrates. In this way, a high level of alignment accuracy can be achieved due to the reduction in transverse movements.
• the invention is based, in particular, on the idea of increasing the alignment accuracy by increasing the rigidity of the device with a portal design and / or by detecting at least three alignment marks (hereinafter also referred to as alignment marks) that are aligned with the linear movement of the substrates.
• At least one alignment mark is preferably attached to and / or on a substrate holder.
• the position detection of the substrate holder supplies correction values for the position and the alignment state of the substrates to be aligned.
• At least one substrate holder has a preferably flat receiving surface for a substrate.
• at least one substrate holder can contain, in particular, prismatic bodies connected monolithically to the receiving surface, which, given a known geometry, can be used as reference surfaces for, in particular, optical position measurements.
• These functional surfaces are designed as laser reflectors, so that the precise position of the body in space can be determined through the geometric shape and knowledge of the point of impact of the laser. The position of the functional surfaces can be measured interferometrically and corrected accordingly in a closed control loop.
• a device for aligning at least two substrates has at least one optical system, having two optics or detection units, in particular aligned with one another, whose optical paths preferably meet at a common focal point.
• the common focal point represents a point of an idealized bonding plane of a first and a second substrate. The substrates are bonded to one another in this plane. The exact description and calibration of the focal points is described in detail in the publication W02014202106.
• the optical system or the acquisition units contain beam shaping and / or deflection elements such as mirrors, lenses, prisms, radiation sources, in particular for Koehler illumination, and image acquisition means such as cameras (CMOS sensors, or CCD, or area or line or point acquisition means such as a phototransistor) and movement means for focusing as well as evaluation means for regulating the optical system.
• beam shaping and / or deflection elements such as mirrors, lenses, prisms, radiation sources, in particular for Koehler illumination
• image acquisition means such as cameras (CMOS sensors, or CCD, or area or line or point acquisition means such as a phototransistor) and movement means for focusing as well as evaluation means for regulating the optical system.
• the device according to the invention includes more than two identical optical systems with aligned optics. Furthermore, the device according to the invention contains substrate holders for holding the substrates to be aligned. One embodiment of the device according to the invention contains at least two displaceable substrate holders which can receive and fasten a first substrate to be aligned and a second substrate to be aligned. Movement and positioning systems of the substrate holders are subsumed as movable substrate holders.
• the substrates can have any shape, but are preferably circular. Wafers are always understood as substrates.
• the diameter of the substrates is, in particular, standardized industrially. For wafers, the industry-standard diameters, 1 ", 2", 3 “, 4", 5 “, 6", 8 “, 12", and 18 ", or the corresponding metric conversions apply.
• the device according to the invention can, however, in principle handle any substrate, regardless of its diameter.
• substrate stack consisting of at least two interconnected substrates instead of a substrate and to connect them to a substrate or to another substrate stack.
• substrate stacks can be used and understood as subsumed under substrates.
• Alignment markings can be any objects that can be aligned with one another, such as crosses, squares, or circles, as well as propeller-like structures or grating structures, in particular phase gratings for the spatial frequency range.
• the alignment markings are preferably detected by means of electromagnetic radiation of a specific wavelength or wavelength ranges, in particular infrared radiation, visible light or ultraviolet radiation. However, it is also possible to use radiation of other wavelength ranges.
• the device according to the invention can contain a system for producing pre-bonds.
• the device according to the invention preferably contains movement devices with drive systems, guide systems, fixtures and measuring systems in order to move, position and align the optical systems and the substrate holders and / or substrates with one another.
• the movement devices can carry out a regulated positioning of the substrate holders, which are guided by control and / or regulating units, in particular computers, and / or regulating algorithms.
• the movement devices can generate any movement as a result of individual movements, so that the movement devices can preferably contain fast coarse positioning devices that do not meet the accuracy requirements as well as precisely working fine positioning devices.
• a setpoint value for the position to be approached is an ideal value.
• the movement device approaches the ideal value. Achieving a defined environment around the ideal value can be understood as reaching the target value.
• a positioning device is understood as a coarse positioning device if the approach and / or repeat accuracy of the target value is less than 0.1%, preferably less than 0.05%, particularly preferably less than 0.01%, based on the entire travel path or range of rotation rotatable rotary drives one full turn of 360 degrees, deviates.
• a pre-aligner with a travel distance of over 600 mm results in an approach accuracy of 600 mm * 0.01%, i.e. less than 60 micrometers as residual uncertainty.
• the residual uncertainty of the approach or repeat accuracy is less than 200 micrometers, preferably less than 150 micrometers, particularly preferably less than 50 micrometers.
• the thermal disturbance variables should also be taken into account.
• a coarse positioning device only fulfills the positioning task with sufficient accuracy if the deviation between the actual position actually reached and the nominal value of the position lies in the travel range of an assigned fine positioning device.
• An alternative coarse positioning device only fulfills the positioning task with sufficient accuracy if the deviation between the actual position actually reached and the nominal value of the position is in half the travel range of an assigned fine positioning device.
• a fine positioning device is understood to be a positioning device if the residual uncertainty of the approach and / or repeat accuracy from the setpoint does not exceed less than 500 ppb, preferably less than 100 ppb, ideally 1 ppb based on the entire travel or rotation range.
• a fine positioning device according to the invention will have an absolute positioning error of less than 5 micrometers, preferably less than 1 micrometer, particularly preferably less than 100 nm, very particularly preferably less than 10 nm, ideally less than 5 nm, ideally less than 1 nm.
• the alignment and possible contacting (fusion bonding) takes place by means of fine drives such as piezo drives.
• the device according to the invention and the associated method preferably have at least two positioning devices of the highest accuracy and reproducibility.
• a mutual error correction concept can be used for the quality of the alignment of the substrates.
• a known offset (rotation and / or displacement) of a substrate and the positioning device corresponding thereto can be compensated for with the adjustment and correction of the position of the other positioning device and the other substrate with correction values or correction vectors. It is a question of the size and type of rotation and / or displacement, how the control or regulation uses the coarse and fine positioning or only the coarse or only the fine positioning for error correction.
• positioning devices coarse or fine or composite positioning devices
• alignment means are used as synonyms.
• the substrates can be aligned with one another in all six degrees of freedom of movement: three translations according to the Cartesian coordinate directions x, y and z and three rotations about these coordinate directions.
• the x, y and z directions or x, y and z positions are understood to mean directions or arranged positions in the Cartesian xyz coordinate system.
• the x and y directions correspond in particular to the lateral direction of the substrate.
• Position features are obtained from the position and / or location values of the alignment markings of the substrates as well as from
• the alignment of the substrates includes, in particular, passive or active wedge error compensation, preferably in accordance with the disclosure in document EP2612109B 1.
• the method according to the invention increases the alignment accuracy in particular by means of additional X, Y position and / or location information, which is acquired with additionally attached acquisition units and / or measuring and regulating systems and used to control / regulate the alignment.
• the additionally attached detection units and / or measuring and control systems can be further optics groups each with two optics facing each other.
• an additional (in particular third) alignment marking is attached to the substrate holder.
• This additional position feature is recorded with at least one additional measuring system with a new, additional optical path.
• the alignment marks on the substrate holders are also aligned with the linear movement of the substrates.
• the position detection of the substrate holder supplies correction values for the position and the alignment state of the substrates to be aligned. Due to the additional measured values and correlations with at least one of the measured values of the other acquisition units, the
• Alignment accuracy increased. Correlation of at least one of the measured alignment markings in the bonding interface between the contact surfaces with an alignment mark on the substrate holder, which is also visible during the alignment of the substrates, becomes the direct Observability of an alignment mark and thus real-time measurement and control during alignment enables.
• the additional measuring system is a laser interferometer.
• a laser interferometer allows the linear movement of the substrate holder to be checked by measuring the change in position (measuring the displacement), the change in the tilt angle (measuring the angle), the flatness (measuring the displacement and angle), the orthogonality (measuring the angle) and, if required, the dynamics (measuring the speed ).
• the measurement of the change in the tilt angle allows the tilting of the slide on a linear guide to be detected.
• the measurement of the straightness allows the detection or the exact recording of horizontal or vertical deviations of the slide path on linear guides.
• a real-time correction of the laser wavelength is necessary depending on the medium. For example, pressure, material temperature and / or gas temperature (if available) must be recorded.
• a particularly preferred embodiment has at least one laser interferometer per substrate holder and / or substrate, preferably two laser interferometers per substrate holder and / or substrate, which the XY position and / or alignment position and / or angular position of both substrate holders and / or the substrates in relation to one defined reference, in particular to the frame, recorded.
• the at least one interferometer is preferably fixed to the frame.
• Robots for substrate handling are subsumed under movement devices.
• the restraints can be part-integrated and / or function-integrated in the movement devices.
• devices according to the invention preferably contain control systems and / or evaluation systems, in particular computers, to control the steps described, in particular movement sequences, to carry out corrections, to analyze and store operating states of the respective device according to the invention.
• Processes are preferably created as recipes and executed in machine-readable form. Recipes are optimized collections of values of parameters that are functionally or process-related. The use of recipes makes it possible to guarantee the reproducibility of production processes.
• the device according to the invention includes supply and auxiliary and / or supplementary systems such as compressed air, vacuum, electrical energy, liquids such as hydraulics, coolants, heating means, means and / or devices for temperature stabilization, electromagnetic shields.
• auxiliary and / or supplementary systems such as compressed air, vacuum, electrical energy, liquids such as hydraulics, coolants, heating means, means and / or devices for temperature stabilization, electromagnetic shields.
• the device according to the invention preferably includes frames, cladding, active or passive subsystems that suppress or dampen or eliminate vibration.
• the detection units preferably together with their movement units, can be arranged in at least one ring-shaped measuring portal, particularly preferably in at least one completely closed, ring-shaped measuring portal, in particular fixed to the frame.
• the preferred embodiment of the device with a single portal is referred to below as a monoportal version.
• the monoportal enables the substrate to be passed through, including the substrate holder, so that at least the alignment marks can be detected the substrates is made possible.
• the positions of the substrate holders can also be recorded.
• a key concept of the invention is, in particular, the achievement of a reduction in the alignment to only a single alignment axis while increasing the alignment accuracy for aligning at least two substrates.
• the design of the device in a closed design increases the rigidity of the device, reduces the ability to oscillate and enables detection of at least two, more preferably three alignment marks that are aligned with the linear movement of the substrates.
• the alignment accuracy is additionally improved by the combination and correlation with directly detectable alignment markings on the substrate holder.
• At least two detection units can be arranged in a main longitudinal axis of the device.
• the at least two detection units can be arranged as an upper and a lower detection unit with preferably a common focal point.
• the upper and lower detection units can be connected to independent movement units with a frame or with the portal in such a way that, in particular, focusing and calibration methods can be carried out, with which in particular a common focus point can be readjusted.
• the movement units of the detection units can be moved in a global, in particular frame-fixed, coordinate system in the main coordinate directions x, y, z.
• the travel paths of the movement units of the detection units in the plane of the substrates, that is to say in the x and y directions, are less than 20 mm, preferably less than 10 mm, particularly preferably less than 5 mm.
• the movement units of the detection units can be moved more than 5 mm, preferably more than 10 mm, especially preferably more than 20 mm, in particular in the z-direction, so that focusing of non-standardized substrate stacks can also be made possible.
• the height of the substrates can be compensated for by positioning the substrate holder in such a way that focusing paths of less than 1 mm, preferably less than 0.5 mm, are used.
• the movement units of the detection units can in particular be designed as backlash-free solid body joints or guides.
• further detection means of all kinds in particular fixed to the frame, can be attached in the portal.
• the device according to the invention contains at least one measuring system, preferably with measuring units for each movement axis, which can in particular be implemented as distance measuring systems and / or as angle measuring systems. Both tactile, i.e. tactile, or non-tactile measuring methods can be used.
• the measurement standard, the unit of measurement can be present as a physical-physical object, in particular as a scale, or it can be present implicitly in the measuring method, such as the wavelength of the radiation used.
• At least one measuring system can be selected and used to achieve alignment accuracy.
• Measurement systems implement measurement methods.
• inductive processes and / or capacitive processes and / or resistive processes and / or comparison processes in particular optical image recognition processes and / or incremental or absolute processes (with in particular glass standards as a scale, or interferometers, in particular laser interferometers, or with magnetic standards) and / or time of flight measurements (Doppler method, time of flight method) or other time recording methods and / or triangulation methods, in particular laser triangulation, and / or autofocus methods and / or intensity measurement methods such as fiber optic range finders are used.
• inductive processes and / or capacitive processes and / or resistive processes and / or comparison processes in particular optical image recognition processes and / or incremental or absolute processes (with in particular glass standards as a scale, or interferometers, in particular laser interferometers, or with magnetic standards) and / or time of flight measurements (Doppler method, time of flight method) or other time recording methods and
• a preferred embodiment includes at least one additional measuring system which detects the XY position and / or alignment position and / or angular position of at least one of the substrates and / or one of the substrate holders in relation to a defined reference, in particular to the frame, preferably in accordance with PCT / EP2016 / 070289.
• a particularly preferred embodiment includes additional measuring systems for all substrate holders which detect the XY position and / or alignment position and / or angular position of both substrate holders and / or the substrates in relation to a defined reference, in particular to the frame.
• a frame can be understood to be a part consisting in particular of natural hard stone or mineral cast or nodular cast iron or hydraulically bound concrete, which is particularly actively or passively vibration-damped and / or vibration-isolated and / or set up with vibration damping.
• the frame can contain further holding and / or guiding functionalities.
• lines for compressed air can be received in the interior of the frame in the frame volume.
• electrical lines and connections can be accommodated in the frame volume.
• fastening elements and / or anchorage points for structures in the frame can be connected, in particular in a form-locking and / or material-locking manner.
• the frame can be produced in a primary molding process, in particular pouring a negative mold.
• the frame can contain cores during pouring.
• the frame can contain a flatness standard.
• a flatness normal can be molded so that the flatness normal can be replicated several times.
• measured values can in particular be combined with one another and / or referenced and / or correlated with one another, so that a measurement of an alignment mark can be used to target the Position of the related other alignment mark can be closed.
• measured values can in particular be correlated with one another, so that the relative positions of the alignment marks to one another are present as values that allow a reference to the frame.
• the position of the substrate holder is measured during the passage through the portal along the three coordinate axes, in particular continuously, so that the real guideway of the substrate is recorded.
• the real guideway is taken into account as a correction factor when calculating the alignment position of the substrates with respect to one another.
• the position of a substrate holder is detected at a point (or location or measurement spot or field of view) in relation to the reference, in particular the first alignment mark on the first substrate and / or the second alignment mark on the second substrate.
• the position of a substrate holder is detected at precisely two points in relation to the reference.
• the position of a substrate holder is detected at precisely three points in relation to the reference, and the position and location of the substrate holder are thus determined.
• optical pattern recognition by means of camera systems and on the substrate holder can be preferred attached patterns can be used.
• the patterns are recorded in a real-time system, in particular continuously during the alignment.
• the position of the substrate holder can be determined by means of a laser interferometer.
• Laser interferometry enables extremely precise, non-contact length measurement by means of interference.
• a laser interferometer allows the linear movement of the substrate holder to be controlled by measuring the change in position (measuring the displacement), the change in the tilt angle (measuring the angle), the flatness (measuring the displacement and angle), the orthogonality (measuring the angle) and the dynamics (measuring the speed with more Beam interferometer).
• the measurement of the change in the tilt angle allows the detection of a tilting of the slide on a linear guide.
• the measurement of the straightness allows the detection or the exact recording of horizontal or vertical deviations of the slide path on linear guides.
• the relative movements of the subsystems can thus be determined.
• two-frequency laser methods can be used. Measurement resolutions of up to 5 nm can be achieved, even more preferably of up to 1 nm (through the use of multiple reflections) at a maximum travel speed of up to 1 m / s. Two-frequency lasers are also used to measure angles.
• Another possibility is the use of several single-frequency laser interferometers installed in parallel. Here are the Displacements determined at several points of the substrate holder. Measurement resolutions of up to 0.1 nm can be achieved. The change in angle can be determined from the distance between the measuring beams and the differences in the displacements that occur.
• interferometers with three measuring beams are used (three-beam interferometer)
• the angular position of the substrate holder and its displacement are determined in two axes.
• a three-beam interferometer is used.
• An additional angle measurement for determining the position of the substrate holder can be carried out with an autocollimation telescope if required.
• measured values of an absolute-incremental displacement encoder can be correlated with the measured values of at least one interferometer and used in addition to one another. This can increase the accuracy of an absolute positioning.
• the measurement methods listed can also be used to determine the position.
• a reversal is also conceivable according to the invention, in particular by attaching the detection units to the substrate holder and attaching alignment markings to the frame.
• control unit and / or regulating unit are, in particular, continuous (and / or digitally time-discrete with a sufficiently high clock frequency), supplied with measured values.
• an alignment mark on the substrate can be detected by means of optical image recognition and / or pattern recognition.
• the position and / or the alignment state of the associated substrate holder and all relevant control parameters can be recorded and stored in a matrix and processed further.
• the position of the substrate holder can be measured with at least one interferometer beam, preferably with at least two interferometer beams, in the optimal case with at least three interferometer beams.
• position values of the substrate holder can be measured by the incremental encoder. These are referenced and, starting from a given position, measure the increase in the path. By combining the relative values of the interferometer and the readings of the incremental position encoder, position values up to the frame can be referenced as zero level and / or zero position.
• At least one interferometer with a correspondingly designed, in particular monolithic, reflector for determining the x-y position and / or orientation of the substrate holder can be used in another embodiment according to the invention.
• Three interferometer beams can be used for this.
• the number of interferometer beams can in particular be equal to the number of reflective surfaces of the reflector. According to the invention, however, it is also conceivable that an extensive reflection surface, in particular a monolithic optical mirror of several interferometer beams is used as a reflector.
• the substrate holder in particular formed from a monolithic block, preferably has at least two of the following functions: substrate fastening by means of vacuum (vacuum paths, connections), shape compensation for deforming the substrate by means of mechanical and / or hydraulic and / or piezoelectronic and / or pyroelectric and / or electrothermal actuating elements, preferably according to the embodiments of EP2656378B1, WO2014191033A1, and WO2019057286A1. Position and / or orientation determination (measuring standards,
• Reflection surfaces and / or prisms in particular the reflectors for interferometry, register marks and / or register mark fields, planar measurement standards for planes, volume standards, in particular steps). Movement (guideways).
• Movement devices according to the invention that are not used for fine adjustment are designed in particular as robot systems, preferably with incremental displacement sensors.
• the accuracy of these movement devices for auxiliary movements is decoupled from the accuracy for aligning the substrate stack, so that the auxiliary movements are carried out with a low repetition accuracy of less than 1 mm, preferably less than 500 micrometers, particularly preferably less than 150 micrometers.
• the control and / or regulation of movement devices according to the invention for (lateral) alignment is carried out in particular on the basis of xy positions and / or alignment positions detected with other measuring means.
• the precision this movement device is preferably less than 200 nm, more preferably less than 100 nm, particularly preferably less than 50 nm, very particularly preferably less than 20 nm, more preferably less than 10 nm, ideally less than 1 nm.
• the detection units in particular together with their movement units, are integrated in two, in particular rigidly, torsionally rigidly connected, fully closed portals.
• the embodiment in particular uses a free optical path from the light source to the alignment mark for the detection of the alignment marks, analogous to WO2014202106A1.
• the device has two portals which are rigidly connected to one another at a distance greater than a substrate diameter.
• SVA SmartView Aligner
• at least two opposing optical detection means with a common focal plane are adjustably arranged in the portal.
• a first, closed portal with detection means is positioned at the end of the travel path, which successively detects alignment marks on the edge of the substrates.
• the substrates are rotated by 90 degrees compared to the SVA and loaded onto the substrate holder so that the alignment marks are aligned with the linear movement, one behind the other.
• the upper and lower substrate holders each move from the overlapping position of the substrates to reach the detection means and expose the edge with the alignment marks.
• a second, closed portal enables the respective substrate holder to be traversed such as the loading or unloading movement.
• the substrates are also moved here in the single alignment axis in order to bring the alignment marks into the optical path of the second portal.
• the alignment of the substrates to one another takes place in particular indirectly on the basis of alignment markings which are located on contact surfaces of the substrates.
• the alignment marks on opposite sides of the opposite substrates are in particular complementary to one another.
• the alignment accuracy can be increased in that an additional, in particular third, alignment mark is additionally detected, which is attached either to one of the substrates to be aligned or to the substrate holder.
• the additional alignment mark is preferably attached to the substrate holder.
• the position detection of the substrate holder supplies correction values for the position and the alignment state of the substrates to be aligned.
• the alignment accuracy is increased by the additional measured values and correlations with at least one of the measured values of the other registration units.
• the additional measuring system is a laser interferometer, preferably a three-beam interferometer.
• Another device has a monoportal, as described above, and a column (C construction), which are rigidly connected to one another, in particular at a distance greater than a substrate diameter.
• the registration units are integrated here in the portal and in the column.
• the embodiment uses, in particular, a free optical path from the light source to the alignment mark for the detection of the alignment marks, analogous to WO2014202106A1.
• a column with detection means is preferably positioned at the end of the travel path, which successively detects alignment marks on the edge of the substrates.
• the substrates are rotated by 90 degrees compared to the SVA and loaded onto the substrate holder so that the alignment marks are aligned with the linear movement, one behind the other.
• the upper and lower substrate holders each move from the overlapping position of the substrates to reach the detection means and expose the edge with the alignment marks.
• the monoportal, as described above, enables the respective substrate holder to be traversed such as the loading or unloading movement.
• the substrates are also moved here in the single alignment axis in order to bring the alignment marks into the optical path of the monoportal and the column.
• the alignment of the substrates to one another takes place in particular indirectly on the basis of alignment markings which are located on contact surfaces of the substrates.
• the alignment marks on opposite sides of the opposite substrates are in particular complementary to one another.
• the alignment accuracy can be increased in that an additional, in particular third, alignment mark is additionally detected, which is attached either to one of the substrates to be aligned or to the substrate holder.
• the additional alignment mark is preferably attached to the substrate holder.
• the position detection of the substrate holder supplies correction values for the position and the alignment state of the substrates to be aligned.
• the alignment accuracy is increased by the additional measured values and correlations with at least one of the measured values of the other registration units. Correlating at least one of the measured alignment markings in the bonding interface between the contact surfaces with an alignment mark on the substrate holder that is also visible during the alignment of the substrates enables the direct observability of an alignment mark and thus real-time measurement and control during the alignment.
• the additional measuring system is a laser interferometer, preferably a three-beam interferometer.
• further detection means in particular fixed to the frame, are attached in the monoportal and in the column. What has been said about the device applies to the embodiment.
• An image-to-image alignment is carried out on the basis of the alignment marks of the substrates.
• the alignment accuracy is also checked in that the position of the substrate holder provides information about the position of the substrates through the additional alignment marks and the actual position of the substrate holder is taken into account by means of correction factors.
• a repeated embodiment of the method according to the invention comprises the following, in particular at least partially sequential and / or simultaneous steps, in particular the following sequence:
• the first / lower substrate is loaded onto the first / lower substrate holder with a supporting surface, with alignment marks on the opposite side (contact side) parallel to the straight line ie are arranged in alignment with the linear movement of the substrates.
• the first / lower substrate is moved with the substrate holder into the field of view of a detection position of a first / upper detection unit of the optical system on the monoportal, in particular using movement devices for rough adjustment.
• the first / lower substrate holder is measured during the entire travel path, in particular by means of a three-beam interferometer. Displacement and angle provide information about the position and tilting of the substrate holder on the linear guide, among other things.
• the X-Y position and / or alignment position of the first substrate holder is acquired by an additional measuring system according to the invention (with a third acquisition unit). Displacement and angle provide information about the location (position) and angle (tilting ie pitch and yaw angle) of the substrate holder on the linear guide. ) Detection of the second alignment mark, in particular by means of pattern recognition. ) Simultaneously, in particular through synchronization with the first acquisition unit, an additional measuring system according to the invention, in particular a
• Three-beam interferometer (with third detection unit) that detects the X-Y position as well as pitch and yaw angles and / or the orientation position of the first substrate holder.
• the first / lower substrate holder is moved out of the field of view (beam path for detection) of the optical system.
• the second / upper substrate is loaded onto the second / upper substrate holder. This method step can already be carried out before one of the previous method steps 0)
• the second / upper substrate holder moves with the second / upper substrate to the monoportal into the field of vision of the optical system. 1) In particular, the second / upper substrate holder is measured by means of a three-beam interferometer during the entire travel path.
• Displacement and angle provide information about the position and tilting of the substrate holder on the linear guide, among other things.
• the second / lower detection unit of the optical system searches and detects the alignment mark on the second / upper substrate.
• the optical system is not moved mechanically, but a correction of the focusing is conceivable. Preferably, however, no focusing movement is carried out.
• an additional measuring system Simultaneously, in particular through synchronization with the second acquisition unit, an additional measuring system according to the invention, in particular a
• Three-beam interferometer detects the X-Y position as well as pitch and yaw angles and / or alignment position of the second substrate holder.
• Detection of the second alignment mark in particular by means of pattern recognition.
• an additional measuring system according to the invention, in particular a
• the control and evaluation computer determines the alignment errors, reference being made to the disclosures in documents US6214692B 1 (Smart View) and US9418882B2 (Enhanced Smart View).
• an alignment error vector is created from the alignment error.
• at least one correction vector is then calculated.
• the correction vector can be a vector that is parallel to the alignment error vector and opposite to it, so that the sum of the alignment error vector and the correction vector results in zero. In special cases, further parameters can be taken into account in the calculation of the correction vector so that the result is different from zero.
• Optional process step The substrates are bonded.
• the bonding can also be a pre-bond or temporary bond.
• Pre-bonding refers to bonding connections which, after the pre-bonding step has taken place, allow the substrates, in particular the wafers, to be separated without irreparable damage to the surfaces.
• the loading sequence of the substrates can be arbitrary. Some process steps, such as loading the substrates, can be carried out simultaneously.
• the additional measuring systems can detect the position and / or location of both the upper and the lower substrate holder and / or the upper and the lower substrate.
• the device according to the invention can also be operated in a vacuum. This makes it possible to use the device in a vacuum cluster or high vacuum cluster.
• FIG. 1 shows a schematic cross-sectional illustration of a first
• Fig. 2 is a schematic cross-sectional representation of a second
• FIG. 3a shows a schematic, enlarged cross-sectional illustration of the first embodiment according to FIG. 1 in a first method step
• FIG. 3b shows a schematic, enlarged cross-sectional illustration of the first embodiment according to FIG. 1 in a second method step
• FIG. 4 shows a schematic, perspective view of an exemplary embodiment of the device according to the invention.
• the same components or components with the same function are identified by the same reference symbols.
• Figures 1 and 2 show schematic cross sections of two embodiments of the devices 1, 1 'according to the invention. These have:
• the device 1, 1 'according to FIGS. 1 and 2 is able to interrelate the substrates 14 (first / lower substrate) and 20 (second / upper substrate) and / or substrate stacks (not shown in FIGS. 1 and 2) align and connect with each other.
• This connection can also be a temporary connection (so-called pre-bond).
• Possible movements / degrees of freedom of the functional components described below in FIGS. 1 to 4 are in some cases also represented symbolically as arrows.
• at least one Y translation unit, one X translation unit, one Z translation unit and one phi rotation unit are possible.
• a phi rotation unit allows the charged substrate 14, 20 to be rotated about its surface normal.
• the resolution of the reproducible positioning capability of all rotation units used is in particular better than 1 °, preferably better than 0.1 °, more preferably better than 0.01 °, most preferably better than 0.001 °, most preferably better than 0.0001 °.
• the resolution of the reproducible positioning ability of all translation units used is in particular better than 100 pm, preferably better than 10 pm, more preferably better than 1 pm, most preferably better than 100 nm, most preferably better than 1 nm.
• the first and second detection units 2, 3 are not able to move in all three spatial directions X, Y and Z.
• the registration units 2, 3 are statically installed in the measuring portal 21.
• the first and second detection units 2 ', 3' are able to move in all three spatial directions.
• rotation units can also be installed which allow rotation of the optical axis about three mutually orthogonal axes.
• the first and second acquisition units 2, 2 ', 3, 3' according to FIGS. 1 and 2 can acquire a focal plane 10 in the opposite direction.
• the common focal point 10p according to FIG. 4 represents a point of an idealized bonding plane of a first and a second substrate.
• the device 1, 1 ‘according to Figures 1 and 2 provides means for additional detection of the movement of the substrates, in particular by length measurements, pitch angle measurements and
• Yaw angle measurements and straightness measurements by an additional third measuring device 4 which are related to at least one fixed, in particular stationary, reference point or a reference and thus enable a correction factor to be determined.
• the additional detection of the movement of the substrates 14, 20 is carried out with a three-beam interferometer or a calibration laser interferometer 4.
• the measuring system 4 uses a new, additional optical path.
• an additional (in particular third) alignment marking 12 is preferably applied to the substrate holder 5, 6.
• a simultaneous length measurement and pitch and yaw angle detection 17 are carried out according to FIGS. 3a and 3b.
• the additional third measuring device 4 in particular a laser interferometer, is stationary or fixed to the frame.
• the position of the substrate holder and / or the substrate can be compared with at least one Frame-mounted laser interferometers, preferably with two frame-mounted laser interferometers, are measured.
• the position detection of the substrate holder 5, 6 supplies correction values for the position and the alignment state of the substrates 14, 20 to be aligned.
• the alignment accuracy is increased.
• the direct observability of the alignment mark 12 and thus real-time measurement and control during alignment allows.
• the first / lower substrate holder 6 or the first / lower movement device 8 moves along a straight guide 18b (according to Figure 4) for the first / lower movement device until the left or first alignment mark 15 of the first / lower substrate is located in the field of vision of the upper measuring device 2 or optics.
• the movements of the translation units and rotation units can be recorded and the recording data are transmitted to the central control unit for further processing and control.
• the first / lower substrate holder 6 or the first / lower movement device 8 moves further along the straight guide 18b (see FIG. 4) for the first / lower movement device 8 until the right or second alignment mark 16 is located of the first / lower substrate 14 is located in the field of vision of the upper measuring device 2 ie of the upper optics.
• the second / upper substrate holder 5 or the second / upper movement device 7 moves along a straight guide 18a (according to FIG. 4) for the second / upper movement device 7 until the left or first alignment mark of the second / upper substrate 20 is located in the field of vision of the lower measuring device 3 ie the lower optics.
• the second / upper substrate holder 5 or the second / upper movement device 7 moves further along the straight guide 18a (see FIG. 4) for the second / upper movement device 7 until the right or second alignment mark of the second / upper substrate 20 in the field of view of the lower measuring device 3 ie the lower optics.
• the optics are controlled in particular in such a way that the position of the alignment mark in relation to the optical axis can be recognized, detected and stored by the optics.
• the design of the device in a closed design increases the rigidity of the device 1, 1 'and reduces the ability to oscillate. It is sufficient to align a guide direction for the substrate holders 5, 6 with one another as precisely as possible.
• a three-beam interferometer 4 allows the linear movement of the substrate holder 5, 6 to be checked by measuring the change in position (measurement of the displacement), the change in the tilt angle (angle measurement), the flatness (measurement of the displacement and angle), the orthogonality (angle measurement) and the dynamics ( Measurement of speed).
• the measurement of the change in the tilt angle allows the detection of a tilting of the slide on a linear guide.
• the measurement of the straightness allows the detection or the exact recording of horizontal or vertical deviations of the slide path on linear guides.
• Position features are derived or calculated from the position and / or location values of the alignment marks 15, 16 of the substrates 14, 20 and of alignment marks 12 on the substrate holder 5, 6.
• the correlation of at least one of the measured alignment markings 15, 16 according to FIGS. 3a and 3b in the bonding interface between the contact surfaces with an alignment mark 12 on the substrate holder 5, 6 that is also visible during the alignment of the substrates 14, 20 enables a continuous, direct correlation of the position data and thus the Real-time measurement and control during alignment.
• the position correction increases the accuracy compared to conventional systems.
• the control and / or regulation of the movement devices for (lateral) alignment is carried out in particular on the basis of X-Y positions and / or alignment positions recorded with other measuring means.
• the accuracy of these movement devices is preferably less than 200 nm, preferably less than 100 nm, particularly preferably less than 50 nm, very particularly preferably less than 20 nm, more preferably less than 10 nm, ideally less than 1 nm.
• the two substrates 14, 20 are aligned in a last step.
• the alignment of the substrates 14, 20 to one another takes place in particular indirectly on the basis of alignment markings 15, 16 which are located on contact surfaces of the substrates 14, 20.
• the substrate holders 5, 6 are moved in a position- and, in particular, position-regulated form until the alignment error, which is derived from the position value of the detection units (optics) and the current position and / or location of the substrate holder 5, 6 ( Three-beam interferometer) is calculated, minimized or, ideally, eliminated.
• a termination criterion is defined.
• the two substrates 14, 20 are finally contacted, preferably exclusively by a movement of the Z translation unit (s) of the substrate receptacles 5, 6.
• the device 1, 1 ‘can be located in a special embodiment in a vacuum chamber or a housing.
• FIG. 4 shows a schematic, perspective view of embodiment 4.
• the first / upper detection unit 2 and, if necessary, further upper detection units and / or sensors and / or measuring units 2 w are integrated in a monoportal 21.
• the second / lower registration unit 3 and, if required, further lower registration units and / or sensors and / or measuring units 3w are also integrated in the monoportal 21 or in the frame 11.
• the embodiment according to FIG. 4 also has:
• FIG. 4 shows the straight guide 18a for the second / upper movement device and the straight guide 18b for the first / lower movement device with fixed bearings 22 and guide elements 23.
• the first alignment mark 15 and the second alignment mark 16 of the first / lower substrate 14 are aligned essentially parallel to the main loading direction of the substrates 14, 20. This direction is given by the straight guides 18a and 18b. Fine drives 19 for corrective movements about all three spatial axes are available for the substrates 14, 20.
• SIGNED LIST 1 device, 2 ‘First / upper registration unit w Further upper registration units and / or
• Detection unit 0 Theoretical focal plane 0p Theoretical focal point 1 Frame 2 Third alignment mark 4 First / lower substrate 5 First alignment mark of the first / lower substrate 6 Second alignment mark of the first / lower substrate 7 Simultaneous length measurement and pitch and yaw angle detection by three-beam interferometer 48a Straight guidance for the second / upper Movement device8b Straight guide for the first / lower movement device9 fine drives Second / upper substrate monoportal fixed bearing

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• 2019
  • 2019-12-10 US US17/783,163 patent/US12106993B2/en active Active
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