The disclosure pertains to semiconductor manufacturing, including manufacturing of wafers.
Modern semiconducting devices, such as processing circuits, memory devices, light detectors, solar cells, light-emitting semiconductor devices, and the like, are often manufactured on silicon wafers (or other suitable substrates). Wafers may undergo numerous processing operations, such as physical vapor deposition, chemical vapor deposition, etching, photo-masking, polishing, and/or various other operations. In a continuous effort to reduce the cost of semiconductor devices, multi-layer stacks of dies, insulating films, patterned and/or doped semiconducting films, and/or other features are often deposited on a single wafer, resulting in high aspect ratio devices, which are used, e.g., in 3D flash memory devices and other applications. Deposition, patterning, etching, polishing, etc., of stacks of multi-layered structures often result in significant stresses applied to the underlying wafers. Such stresses lead to both an out-of-plane distortion and an in-plane distortion of features supported by the wafers. These distortions result in misalignment of deposited features and can significantly degrade quality of manufactured devices.
The present disclosure will be understood more fully from the detailed description given below and from the accompanying drawings of various implementations of the disclosure.
In one implementation, disclosed is a method to correct an out-of-plane deformation of a substrate, the method comprising identifying, using optical inspection data, a profile of the out-of-plane deformation of the substrate. The method further includes performing a polynomial decomposition of the identified profile to determine a plurality of polynomial coefficients, each of the plurality of polynomial coefficients characterizing a respective one of a plurality of elemental deformation shapes of the substrate. The method further includes identifying, based on at least a subset of the plurality of polynomial coefficients, one or more characteristics of a stress-compensation layer (SCL) for the substrate. The method further includes causing the SCL to be deposited on the substrate, and performing a plurality of statistical simulations to identify settings for a non-uniform stress-mitigation irradiation of the SCL, wherein performing the plurality of statistical simulations comprises sampling from one or more statistical distributions associated with previously performed stress-mitigation irradiations. The method further includes performing the non-uniform stress-mitigation irradiation of the SCL using the identified settings, wherein the non-uniform stress-mitigation irradiation is performed using at least first settings for a first region of the SCL and second settings for a second region of the SCL.
In another implementation, disclosed is a system that includes a memory and a processing device communicatively coupled to the memory. The processing device is to identify, using optical inspection data, a profile of an out-of-plane deformation of a substrate. The processing device is further to perform a polynomial decomposition of the identified profile to determine a plurality of polynomial coefficients, each of the plurality of polynomial coefficients characterizing a respective one of a plurality of elemental deformation shapes of the substrate. The processing device is further to identify, based on at least a subset of the plurality of polynomial coefficients, one or more characteristics of a stress-compensation layer (SCL) for the substrate. The processing device is further to cause the SCL to be deposited on the substrate. The processing device is further to perform a plurality of statistical simulations to identify settings for a non-uniform stress-mitigation irradiation of the SCL, wherein performing the plurality of statistical simulations comprises sampling from one or more statistical distributions associated with previously performed stress-mitigation irradiations. The processing device is further to perform the non-uniform stress-mitigation irradiation of the SCL using the identified settings, wherein the non-uniform stress-mitigation irradiation is performed using at least first settings for a first region of the SCL and second settings for a second region of the SCL.
In another implementation, disclosed is a semiconductor manufacturing system that includes one or more processing chambers to process a substrate and a computing device. The computing device is to identify, using optical inspection data, a profile of an out-of-plane deformation of a substrate and perform a polynomial decomposition of the identified profile to determine a plurality of polynomial coefficients, each of the plurality of polynomial coefficients characterizing a respective one of a plurality of elemental deformation shapes of the substrate. The computing device is further to identify, based on at least a subset of the plurality of polynomial coefficients, one or more characteristics of a stress-compensation layer (SCL) for the substrate, causing the SCL to be deposited on the substrate. The computing device is further to perform a plurality of statistical simulations to identify settings for a non-uniform stress-mitigation irradiation of the SCL, wherein performing the plurality of statistical simulations comprises sampling from one or more statistical distributions associated with previously performed stress-mitigation irradiations. The computing device is further to perform the non-uniform stress-mitigation irradiation of the SCL using the identified settings, wherein the non-uniform stress-mitigation irradiation is performed using at least first settings for a first region of the SCL and second settings for a second region of the SCL.
In yet another implementation, disclosed is a non-transitory computer-readable memory storing instructions thereon that, when executed by a processing device, cause the processing device to perform operations that include identifying, using optical inspection data, a profile of an out-of-plane deformation of a substrate. The operations further include performing a polynomial decomposition of the identified profile to determine a plurality of polynomial coefficients, each of the plurality of polynomial coefficients characterizing a respective on of a plurality of elemental deformation shapes of the substrate. The operations further include identifying, based on at least a subset of the plurality of polynomial coefficients, one or more characteristics of a stress-compensation layer (SCL) for the substrate. The operations further include causing the SCL to be deposited on the substrate. The operations further include performing a plurality of statistical simulations to identify settings for a non-uniform stress-mitigation irradiation of the SCL, wherein performing the plurality of statistical simulations comprises sampling from one or more statistical distributions associated with previously performed stress-mitigation irradiations. The operations further include performing the non-uniform stress-mitigation irradiation of the SCL using the identified settings, wherein the non-uniform stress-mitigation irradiation is performed using at least first settings for a first region of the SCL and second settings for a second region of the SCL.
Existing technology includes a number of methods to address substrate or wafer deformation. For example, a deformed (warped) substrate, such as silicon wafer, with various films and features deposited on one side (referred to as the front side, top side, or main side herein) can be coated on the other side (referred to as the back side or bottom side herein) with a film that exerts a compression stress or tensile stress on the wafer. Such back side-deposited deformation-correcting film, also referred to as stress-compensation layer herein, usually imparts a uniform (or global) stress to the entire wafer and cannot compensate for local stress modulation and/or anisotropic stress. Additional correction can be achieved by implanting ions into the stress-compensation layer, e.g., using a beam of ions to bombard the stress-compensation layer, to adjust the stress in the stress-compensation layer and, consequently, to further mitigate the deformation of the underlying wafer.
A “wafer,” as used herein, refers to any substrate or material surface formed on a substrate upon which film processing is performed during a fabrication process. For example, a wafer surface on which processing can be performed includes materials such as silicon, silicon oxide, silicon nitride, strained silicon, silicon on insulator, carbon doped silicon oxides, amorphous silicon, doped silicon, germanium, gallium arsenide, glass, sapphire, and any other materials such as metals, metal nitrides, metal alloys, and other conductive materials, depending on the application. In some instances, wafers can include plastic substrates. Wafers include, without limitation, semiconductor wafers. Wafers may be exposed to a pretreatment process to polish, etch, reduce, oxidize, hydroxylate, anneal, UV cure, e-beam cure and/or bake the substrate surface. In addition to film processing directly on the surface of the wafer itself, any of the film processing steps disclosed may also be performed on an underlayer formed on the wafer as disclosed in more detail below, and the term “wafer surface” is intended to include such underlayer as the context indicates. Thus, for example, where a film/layer or partial film/layer has been deposited onto a wafer surface, the exposed surface of the newly deposited film/layer becomes the wafer surface. In some embodiments, wafers have a thickness in the range of 0.25 mm to 1.5 mm, or in the range of 0.5 mm to 1.25 mm, in the range of 0.75 mm to 1.0 mm, or more. In some embodiments, wafers have diameter of about 10 cm, 20 cm, 30 cm, or more.
Deposition of stress-compensation layers with ion implantation can be quite efficient in correcting stresses that are uniform and isotropic, σxx≈σyy. On the other hand, mitigating stresses that vary with location x, y on the wafer, σjk(x, y), stresses that are anisotropic, σxx≠σyy, or both is a much more challenging problem. Certain feature patterns can result in stresses that are compressive along one direction, e.g., σxx>0, and tensile along a perpendicular direction, σyy<0, e.g., as illustrated in
Aspects and implementations of the present disclosure address these and other challenges of the modern semiconductor manufacturing technology by providing for systems and techniques that can mitigate non-uniform and/or anisotropic stresses and deformations of wafers. In one embodiment, a vertical profile of wafer deformation z=h(r, ϕ) may be measured using optical metrology techniques. For example, an interferogram of the profile h(r, ϕ) can be obtained using optical interferometry measurements. The wafer profile h(r, ϕ) can then be represented via a number of parameters that qualitatively and quantitatively characterize geometry of the wafer deformation. In some embodiments, a set of Zernike (or a similar set of) polynomials may be used to represent the wafer profile,
where r is the radial coordinate and ϕ is the polar angle coordinate within the (average) plane of the wafer. Consecutive coefficients A1, A2, A3, A4 . . . represent weights of specific geometric features (elemental deformations) of the wafer described by the corresponding Zernike polynomials Z1(r, ϕ), Z2(r, ϕ), Z3(r, ϕ), Z4(r, ϕ) . . . . The first three coefficients are of less interest as they describe a uniform shift of the wafer (coefficient A1, associated with the Z1(r, ϕ)=1 polynomial), a deformation-free x-tilt that amounts to a rotation around the y-axis (coefficient A2, associated with the Z2(r, ϕ)=2r cos ϕ polynomial), and a deformation-free x-tilt that amounts to a rotation around the x-axis (coefficient A3, associated with the Z3(r, ϕ)=2r sin ϕ polynomial) that can be eliminated by a realignment of the coordinate axis. The fourth coefficient A4 is associated with Z4(r, ϕ)=√{square root over (3)}(2r2−1) and characterizes an isotropic paraboloid deformation (“bow”). The fifth A5 and the sixth A6 coefficients are associated with Z5(r, ϕ)=√{square root over (6)}r2 sin 2ϕ and Z6 (r, ϕ)=√{square root over (6)}r2 cos 2ϕ polynomials, respectively, and characterize a saddle-type deformation. The A5 coefficient characterizes a saddle shape that curves down (A5>0) or up (A5<0) along the diagonal y=x and curves up (A5>0) or down (A5<0) along the diagonal y=−x. The A6 coefficient characterizes a saddle shape that curves up (A6>0) or down (A6<0) along the x-axis and curves down (A6>0) or up (A6<0) along the y-axis. The higher coefficients A7, A8, etc., characterize progressively faster variations of the wafer deformation h(r, ϕ) along the radial direction, along the azimuthal direction, or both and collectively represent a residual deformation, hres(r, ϕ)=h(r, ϕ)−Σj=46AjZj(r, ϕ).
In some embodiments, selection of a thickness d of the deformation-compensating film can be made based on a value of the paraboloid bow coefficient A4.
A material (type) of stress-compensation layer 108 can be selected based on the sign of coefficient A4. For example, for a negative bow, A4<0, and stress-compensation layer 108 may be selected to have a tensile stress (as illustrated in
The overcorrection is chosen in conjunction with the implant species, energy, and dose to ensure maximum entitlement from the stress compensation. The overcorrection makes the combined structure of wafer 102 and stress-compensation layer 108 susceptible to further control of stress (and thus deformation of the wafer hcorr(r, ϕ)). As illustrated in
Although, for the sake of specificity, a stress-mitigation beam that is used to modify the stress in stress-compensation layer 108 is referred to as ion beam (e.g., ion beam 112) throughout this disclosure, the stress-mitigation beam can include other matter particles (e.g., electrons), electromagnetic waves (e.g., UV light, visible light, infrared light, etc.), and/or a suitable combination thereof. The stress-mitigation beam strikes stress-compensation layer 108 and changes the bonding network of stress-compensation layer 108. For example, the stress-mitigation beam of low energy may interact with surface atoms of stress-compensation layer 108, e.g., removing some of the surface atoms, effectively implementing etching of surface regions of stress-compensation layer 108. The effectiveness of such etching may be controlled by a choice of ion species/radicals/ambient gasses. In another example, the stress-mitigation beam of high energy can deposit ions inside stress-compensation layer 108. Ions and/or photons can break bonds of the bonding network (or crystal lattice) of stress-compensation layer 108 forming vacancies therein, and can further cause annealing due to local heating, UV curing, and/or other effects.
In some embodiments, the number of ions ΔNi deposited per small area ΔA=ΔxΔy of the wafer may be determined using simulations (performed as described in more detail below) based on the local value of the corrected deformation hcorr(r, ϕ), which may include a saddle deformation, a residual deformation, and the part of the paraboloid bow deformation Acorr(d)+A4 that has been overcorrected by the deposition of stress-compensation layer 108. The desired local density ΔNi/ΔxΔy of the ions can be delivered by controlling the scanning velocity v of ion beam 112. In some embodiments, ion beam 112 has a profile that can be approximated with a Gaussian function, e.g., the ion flux j(φ=j0 exp(−x2/a2−y2/b2), where x and y are Cartesian coordinates, j0 is the maximum ion flux at the center of the beam, and a and b is are characteristic spreads of the beam along the x-axis and y-axis, respectively. Correspondingly, a point that is located at distance y from the path of the center of the beam receives an ion dose that includes the following number of ions:
Correspondingly, by reducing the scanning velocity v, the number of ions received by various regions of stress-compensation layer 108 can be increased, and vice versa. Additionally, ion beam 112 can perform multiple scans with different offsets y so that various points of stress-compensation layer 108 receive multiple doses of ions with different factors e−y
As illustrated in
The techniques of strain and deformation mitigation illustrated in
This structure of the stress tensor is usually a good approximation since the wafer is typically in a state of pure bending and independent of the shear stresses that are represented by the off-diagonal terms in the stress tensor. Correction of the saddle shape requires special handling in the computation of the dose map and optimization to ensure that additional residual terms are not introduced into the wafer as a result.
At block 610, process 600 includes measuring the shape of a wafer, e.g., a displacement of a surface (e.g., top surface) of a wafer as a function of some in-plane coordinates, e.g., polar coordinates z=h(r, ϕ), Cartesian coordinates, z=h(x, y), or any other suitable coordinates. At block 620, process 600 includes decomposition of the determined shape over a suitable set of polynomials, e.g., Zernike polynomials, and obtaining a set of polynomial expansion coefficients, {Aj}=(A1, A2, A3) A4, A5, A6, A7 . . . , each coefficient in the set characterizing a degree of presence of a particular elemental geometric shape in the wafer's deformation. At a decision-making block 625, process 600 includes determining what type of a deformation-compensating film is to be used with the wafer. In some embodiments, the decision can be made based on a coefficient that determines a degree of parabolicity of the deformation, e.g., coefficient A4. If the wafer is curved downwards (towards the back side of the wafer), process 600 can select, at block 630, a compressive film for back side deposition and stress mitigation in the wafer. If the wafer is curved upward (towards the top side of the wafer), process 600 can select, at block 632, a tensile film for back side deposition and stress mitigation.
At block 640, process 600 can continue with determining a type of material for the deformation-compensating film to be deposited and thickness d of the film. As illustrated with the dashed arrow in
In other words, the target paraboloid deformation Ã4 can be chosen sufficiently large to compensate for the paraboloid deformation (A4), saddle deformation (A5 and A6) and the residual deformation (A7, and higher coefficients). In some embodiments, the target paraboloid deformation Ã4 can be selected with at least an excess magnitude AE over the minimum needed to overcompensate for the wafer deformation, e.g.,
The excess magnitude AE can be empirically selected and can depend on the specific material used for the deformation-compensating film.
Once the target paraboloid deformation Ã4 has been determined, the thickness of the film d can be selected using a calibration data that tabulates or otherwise defines a function d=ƒ(Ã4). In some embodiments, the function ƒ(Ã4) can be a non-linear function. In some embodiments, the function ƒ(Ã4) can be a linear function, d=αÃ4, with a coefficient of proportionality a determined based on mathematical modeling of elastic equations, empirical calibration, or any combination thereof. At block 650, the deformation-compensating film of the selected thickness d is deposited on the back side of the wafer. At block 660, doses for ion implantation are computed. In some embodiments, ion doses are computed based on the expansion coefficients A5, A6 (to compensate for the saddle deformation) and A7, A8 . . . (to compensate for the residual deformation). In some embodiments, ion doses are computed following a new measurement of the deformation of the wafer that is performed after block 650 (not shown in
At block 720, process 700 can include performing Monte Carlo simulations for the wafer and the deposited film. The Monte Carlo simulations can be performed for a film made of the actual material (or a material compound) used in deposition and having a specific thickness d. An initial Monte Carlo simulation can be performed for specific baseline (default) conditions of the ion implantation (e.g., default settings of an ion implantation apparatus). The baseline conditions can include a default type of ions, a default energy of ions, a default dose of ions to be imparted to the film (e.g., a default velocity of scanning and a default scanning pattern), and the like. The Monte Carlo simulations can use measurement data (calibration data) 722 collected for actual ion implantation performed for various ion energies, types of ions, types and materials of deposition films, angles of ion incidence on the films, and/or the like.
Measurement data 722 can include characterization of the number of vacancies created by ions of different types and energies.
As illustrated in
Measurement data 722 can further include characterization of the number of vacancies created by ions incident at different angles.
With a continuing reference to
Performing the Monte Carlo simulation can include sampling from the stored distributions and identifying a likelihood that a target stress mitigation (e.g., determined as described above in conjunction with process 600 illustrated in
At block 755, process 700 can include verifying if the number of expected formed vacancies is sufficient. To verify sufficiency, process 700 can assess stress mitigation caused by formed vacancies. In one embodiment, process 700 can begin at some value of stress in the stress-compensation layer, e.g., −3.0 GPa or some other suitable value (negative sign indicating compressive stress) and use ion implants to mitigate this stress towards a neutral point, 0.0 GPa at various locales of the stress-compensation layer.
If the number of vacancies is insufficient, process 700 can include increasing a dose of ions (at block 760) and repeating Monte Carlo simulations for the increased dose.
At block 765, process 700 can include verifying that the vacancies are going to be placed within a target depth, e.g., the thickness d of the film or a certain fraction of the film, such as 0.8d, 0.7d, 0.5d, or some other value empirically set to prevent ions from penetrating into the wafer and affecting wafer's properties. If the vacancies are formed at depths that exceed the target depth, process 700 can include (at block 770) increasing an angle of incidence (tilt of ion beam implanter 110) dose of ions to keep vacancies (as well as substitution impurities) to a shallower region of the film.
Blocks 725-765 can be repeated multiple times until the Monte Carlo simulations predict that the desired stress mitigation can be achieved, e.g., that the reduction in the tensile stress of the deformation-compensating film is such that the saddle deformation and the residual deformation of the wafer are eliminated or at least reduced to an acceptable tolerance. The final settings for ion implantation (at block 780) determined from the Monte Carlo simulations can then be used for ion implantation (at block 790).
To compensate for the saddle deformation and the residual deformation, the Monte Carlo simulations can be performed separately for different regions of the wafer to ensure that location-dependent local stresses σxx(x, y) and σyy(x, y) are mitigated to the same or approximately the same uniform baseline value σbase. Correspondingly, different regions of the deformation-compensating film can receive different doses of ions. In some instances, different regions of the deformation-compensating film can receive ions with different directions of incidence.
Operations of ion implantation system 1300 can be controlled by a controller 1314, which can include any suitable computing device, microcontroller, or any other processing device having a processor, e.g., a central processing unit (CPU), a field-programmable gate array (FPGA), an application-specific integration circuit (ASIC), and/or the like, and a memory device, e.g., a random-access memory (RAM), read-only memory (ROM), flash memory, and/or the like or any combination thereof. Controller 1314 can control operations of power source 1306, support stage 1312, and/or various other components and modules of ion implantation system 1300. Controller 1314 can include an ion beam simulation module 1316 capable of performing simulations as described above in conjunction with
Example computer system 1400 may include a processing device 1402 (also referred to as a processor or CPU), a main memory 1404 (e.g., read-only memory (ROM), flash memory, dynamic random access memory (DRAM) such as synchronous DRAM (SDRAM), etc.), a static memory 1406 (e.g., flash memory, static random access memory (SRAM), etc.), and a secondary memory (e.g., a data storage device 1418), which may communicate with each other via a bus 1430.
Processing device 1402 represents one or more general-purpose processing devices such as a microprocessor, central processing unit, or the like. Processing device 1402 includes processing logic 1426. Processing device 1402 may be a complex instruction set computing (CISC) microprocessor, reduced instruction set computing (RISC) microprocessor, very long instruction word (VLIW) microprocessor, processor implementing other instruction sets, or processors implementing a combination of instruction sets. Processing device 1402 may also be one or more special-purpose processing devices such as an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a digital signal processor (DSP), network processor, or the like. In accordance with one or more aspects of the present disclosure, processing device 1402 may be configured to execute instructions implementing example process 600 of mitigation of wafer stress and deformation and/or example process 700 of ion implantation performed for mitigation of wafer stress and deformation.
Example computer system 1400 may further comprise a network interface device 1408, which may be communicatively coupled to a network 1420. Example computer system 1400 may further comprise a video display 1410 (e.g., a liquid crystal display (LCD), a touch screen, or a cathode ray tube (CRT)), an alphanumeric input device 1412 (e.g., a keyboard), a cursor control device 1414 (e.g., a mouse), and an acoustic signal generation device 1416 (e.g., a speaker).
Data storage device 1418 may include a computer-readable storage medium (or, more specifically, a non-transitory computer-readable storage medium) 1424 on which is stored one or more sets of executable instructions 1422. In accordance with one or more aspects of the present disclosure, executable instructions 1422 may comprise executable instructions implementing example process 600 of mitigation of wafer stress and deformation and/or example process 700 of ion implantation performed for mitigation of wafer stress and deformation.
Executable instructions 1422 may also reside, completely or at least partially, within main memory 1404 and/or within processing device 1402 during execution thereof by example computer system 1400, main memory 1404 and processing device 1402 also constituting computer-readable storage media. Executable instructions 1422 may further be transmitted or received over a network via network interface device 1408.
While the computer-readable storage medium 1424 is shown in
Some portions of the detailed descriptions above are presented in terms of algorithms and symbolic representations of operations on data bits within a computer memory. These algorithmic descriptions and representations are the means used by those skilled in the data processing arts to most effectively convey the substance of their work to others skilled in the art. An algorithm is here, and generally, conceived to be a self-consistent sequence of steps leading to a desired result. The steps are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. It has proven convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like.
It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise, as apparent from the following discussion, it is appreciated that throughout the description, discussions utilizing terms such as “identifying,” “determining,” “storing,” “adjusting,” “causing,” “returning,” “comparing,” “creating,” “stopping,” “loading,” “copying,” “throwing,” “replacing,” “performing,” or the like, refer to the action and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical (electronic) quantities within the computer system's registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices.
Examples of the present disclosure also relate to an apparatus for performing the methods described herein. This apparatus may be specially constructed for the required purposes, or it may be a general purpose computer system selectively programmed by a computer program stored in the computer system. Such a computer program may be stored in a computer readable storage medium, such as, but not limited to, any type of disk including optical disks, CD-ROMs, and magnetic-optical disks, read-only memories (ROMs), random access memories (RAMs), EPROMs, EEPROMs, magnetic disk storage media, optical storage media, flash memory devices, other type of machine-accessible storage media, or any type of media suitable for storing electronic instructions, each coupled to a computer system bus.
The methods and displays presented herein are not inherently related to any particular computer or other apparatus. Various general purpose systems may be used with programs in accordance with the teachings herein, or it may prove convenient to construct a more specialized apparatus to perform the required method steps. The required structure for a variety of these systems will appear as set forth in the description below. In addition, the scope of the present disclosure is not limited to any particular programming language. It will be appreciated that a variety of programming languages may be used to implement the teachings of the present disclosure.
It is to be understood that the above description is intended to be illustrative, and not restrictive. Many other implementation examples will be apparent to those of skill in the art upon reading and understanding the above description. Although the present disclosure describes specific examples, it will be recognized that the systems and methods of the present disclosure are not limited to the examples described herein, but may be practiced with modifications within the scope of the appended claims. Accordingly, the specification and drawings are to be regarded in an illustrative sense rather than a restrictive sense. The scope of the present disclosure should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.
This application claims the benefit of U.S. Provisional Patent Application No. 63/444,158, filed Feb. 8, 2023, entitled “Mitigation of stress and deformation in wafers”; U.S. Provisional Patent Application No. 63/491,170, filed Mar. 20, 2023, entitled “Optimized film deposition and ion implantation for mitigation of stress and deformation in wafers”; U.S. Provisional Patent Application No. 63/502,447, filed May 16, 2023, entitled “Mitigation of saddle deformation of wafers using film deposition and edge ion implantation”; U.S. Provisional Patent Application No. 63/502,448, filed May 16, 2023, entitled “Influence function-based mitigation of wafer deformation with film deposition and ion implantation”; U.S. Provisional Patent Application No. 63/502,452, filed May 16, 2023, entitled “Cylindric decomposition for efficient mitigation of wafer deformation with film deposition and ion implantation”; and U.S. Provisional Patent Application No. 63/511,414, filed Jun. 30, 2023, entitled “Wafer stress management for precise wafer-to-wafer bonding,” the contents of which are incorporated by reference in their entirety herein.
Number | Date | Country | |
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63444158 | Feb 2023 | US | |
63491170 | Mar 2023 | US | |
63502452 | May 2023 | US | |
63502448 | May 2023 | US | |
63502447 | May 2023 | US | |
63511414 | Jun 2023 | US |