Cylindrical decomposition for efficient mitigation of substrate deformation due to film deposition and ion implantation

Abstract

The disclosed system and technique are intended to correct out-of-plane deformation (OPD) of a substrate. The technique includes using optical inspection data to obtain an OPD profile of the substrate, obtaining a polynomial representation of the OPD profile, and determining a plurality of polynomial coefficients that characterize each fundamental deformation shape of the substrate. The technique further includes identifying one or more cylindrical decompositions of a parabolic portion of the OPD profile, and calculating one or more characteristics of a stress compensation layer (SCL) for the substrate using a selected one of the one or more cylindrical decompositions. The technique further includes depositing the SCL on the substrate and exposing the SCL to a stress relaxation beam.

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE This disclosure relates to semiconductor manufacturing, including wafer manufacturing. [Background technology]

[0002] Modern semiconductor devices, such as processing circuits, memory devices, photodetectors, solar cells, and light-emitting semiconductor devices, are often fabricated on silicon wafers (or other suitable substrates). The wafers may undergo numerous processing steps, such as physical vapor deposition, chemical vapor deposition, etching, photomasking, polishing, and / or various other processes. In a continuing effort to reduce the cost of semiconductor devices, multilayer stacks of die, insulating films, patterned and / or doped semiconductor films, and / or other features are often deposited on a single wafer, resulting in high-aspect-ratio devices used, for example, in 3D flash memory devices and other applications. The deposition, patterning, etching, polishing, etc. of the multilayer stacks often imposes significant stresses on the underlying wafer. Such stresses result in both out-of-plane and in-plane distortion of features supported by the wafer. These distortions can lead to misalignment of the deposited features, significantly reducing the quality of the fabricated devices. [Brief explanation of the drawings]

[0003] The present disclosure will become more fully understood from the following detailed description and accompanying drawings of various embodiments of the disclosure. [Figure 1] 1A-E illustrate a schematic process for stress compensating a backside deposited film using additional ion implantation, according to at least one embodiment. [Figure 2] FIG. 2 shows an example of a Zernike polynomial decomposition, in arbitrary units, of the actual deformation of one of the wafers (top left) into a parabolic curvature deformation (top right), a saddle deformation (bottom left), and a residual deformation (bottom right), according to at least one embodiment. [Figure 3]FIG. 3 illustrates stress and strain relief in one exemplary wafer using the process disclosed in connection with FIGS. 1A-E, according to at least one embodiment. [Figure 4] FIG. 4 illustrates one exemplary profile of a Gaussian ion beam that may be used to relieve stress and deformation in a wafer, according to at least one embodiment. [Figure 5] FIG. 5 illustrates an exemplary silicon wafer having a silicon nitride film deposited thereon having a saddle-shaped deformation, according to at least one embodiment. [Figure 6A] FIG. 6A illustrates an exemplary positive cylindrical decomposition of the quadratic portion of the wafer deformation, according to at least one embodiment. [Figure 6B] FIG. 6B illustrates an exemplary negative cylindrical decomposition of the quadratic portion of the wafer deformation, according to at least one embodiment. [Figure 7] FIG. 7 is a flow diagram illustrating an exemplary process for mitigating wafer deformation using cylindrical decomposition, according to at least one embodiment. [Figure 8] 8A is a schematic diagram of an ion implantation system capable of performing ion implantation into a stress compensation layer, according to at least one embodiment, and FIG. 8B illustrates the delivery of ions to a wafer at an arbitrary angle of incidence by the ion implantation system of FIG. 8A, according to at least one embodiment. [Figure 9] FIG. 9 illustrates a block diagram of an exemplary computer system capable of supporting the processes of the present disclosure, in accordance with at least one embodiment. Summary of the Invention

[0004] In one embodiment, a method for correcting out-of-plane deformation of a substrate is disclosed, including obtaining an OPD profile of the substrate using optical inspection data. The method further includes performing a polynomial representation of the OPD profile to determine a plurality of polynomial coefficients, each of the plurality of polynomial coefficients characterizing a respective one of a plurality of elementary deformation shapes of the substrate. The method further includes identifying one or more cylindrical decompositions of a quadratic portion of the OPD profile based on at least a subset of the plurality of polynomial coefficients, each of the one or more cylindrical decompositions including decomposing the OPD profile into at least a parabolic deformation of the substrate and a cylindrical deformation of the substrate. The method further includes calculating one or more characteristics of a stress compensation layer (SCL) for the substrate using a selected one of the one or more cylindrical decompositions. The method further includes depositing the SCL on the substrate and exposing the SCL to a stress relaxation beam.

[0005] In another embodiment, a system is disclosed that includes a memory and a processing device communicatively coupled to the memory, the processing device configured to use optical inspection data to obtain an out-of-plane deformation profile (OPD profile) of the substrate. The processing device is further configured to implement a polynomial representation of the OPD profile to determine a plurality of polynomial coefficients, each of the plurality of polynomial coefficients characterizing a respective one of a plurality of elementary deformation shapes of the substrate. The processing device is further configured to identify one or more cylindrical decompositions of a quadratic portion of the OPD profile based on at least a subset of the plurality of polynomial coefficients, each of the one or more cylindrical decompositions decomposing the OPD profile into at least a parabolic deformation of the substrate and a cylindrical deformation of the substrate. The processing device is further configured to calculate one or more characteristics of a stress compensation layer (SCL) for the substrate using a selected one of the one or more cylindrical decompositions. The processing device is further configured to deposit the SCL on the substrate and expose the SCL to a stress relaxation beam.

[0006] In another embodiment, a semiconductor manufacturing system is disclosed that includes one or more processing chambers for processing a substrate and a computing device. The computing device is configured to: acquire an OPD profile of the substrate using optical inspection data; acquire a polynomial representation of the OPD profile to determine a plurality of polynomial coefficients, each of the plurality of polynomial coefficients characterizing a respective one of a plurality of elementary deformation shapes of the substrate; identify one or more cylindrical decompositions of a quadratic portion of the OPD profile based on at least a subset of the plurality of polynomial coefficients, each of the one or more cylindrical decompositions decomposing the OPD profile into at least a parabolic deformation of the substrate and a cylindrical deformation of the substrate; and calculate one or more properties of a stress compensation layer (SCL) for the substrate using a selected one of the one or more cylindrical decompositions, depositing the SCL on the substrate and exposing the SCL to a stress relaxation beam.

[0007] In yet another embodiment, a non-transitory computer-readable memory is disclosed that stores instructions that, when executed by a processing device, cause the processing device to perform processes including obtaining an out-of-plane deformation profile (OPD profile) of a substrate using optical inspection data. The processes further include performing a polynomial representation of the OPD profile to determine a plurality of polynomial coefficients, each of the plurality of polynomial coefficients characterizing a respective one of a plurality of elementary deformation shapes of the substrate. The processes further include identifying one or more cylindrical decompositions of a quadratic portion of the OPD profile based on at least a subset of the plurality of polynomial coefficients, each of the one or more cylindrical decompositions including decomposing the OPD profile into at least a parabolic deformation of the substrate and a cylindrical deformation of the substrate. The processes further include calculating one or more characteristics of a stress compensation layer (SCL) for the substrate using a selected one of the one or more cylindrical decompositions. The processes further include depositing the SCL on the substrate and exposing the SCL to a stress relaxation beam. DETAILED DESCRIPTION OF THE INVENTION

[0008] Existing technologies include many methods for addressing wafer deformation. For example, a deformed (warped) wafer with various films and features deposited on one side (referred to herein as the front, top, or main side) can be coated on the other side (referred to herein as the back or bottom side) with a film that imposes compressive or tensile stress on the wafer. Such backside-deposited deformation-compensating films, also referred to herein as stress-compensating layers or films, typically impart a uniform (or global) stress across the wafer and are unable to compensate for local stress adjustment and / or anisotropic stress. Additional compensation can be achieved by implanting ions into the stress-compensating layer, e.g., using an ion beam bombarding the stress-compensating layer, to adjust the stress of the stress-compensating layer, thereby further mitigating the deformation of the underlying wafer.

[0009] As used herein, "wafer" refers to any substrate or any material surface formed on a substrate on which film processing is performed during a manufacturing process. For example, wafer surfaces on which processing can be performed include materials such as silicon, silicon oxide, silicon nitride, strained silicon, silicon-on-insulator, carbon-doped silicon oxide, 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. Wafers include, but are not limited to, semiconductor wafers. In some cases, wafers can include plastic substrates. Wafers may be exposed to pre-treatment processes to polish, etch, reduce, oxidize, hydroxylate, anneal, UV cure, electron beam (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 disclosed film processing steps may also be performed on underlying layers formed on the wafer, as disclosed in more detail below. The term "wafer surface" is intended to include such underlying layers as the context indicates. Thus, for example, if a film / layer or partial film / layer is being deposited on a wafer surface, the exposed surface of the newly deposited film / layer becomes the wafer surface. In some embodiments, the wafer has 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, or in the range of 0.75 mm to 1.0 mm, or greater. In some embodiments, the wafer has a diameter of about 10 cm, 20 cm, 30 cm, or greater.

[0010] Deposition of the stress compensation layer in combination with ion implantation provides a uniform and isotropic It can be very efficient to correct TIFF2026506869000002.tif6170. Relieving stresses that vary in one direction, e.g., This can cause tensile stress along the wafer, resulting in the formation of a saddle-shaped wafer, such as that shown in FIG. 5. Such saddle-shaped features can arise, for example, in stacks of materials with directional patterning, such as the patterning of word lines in flash memory devices. Correcting such anisotropic saddle-shaped deformation in wafers remains a challenging task.

[0011] Aspects and embodiments of the present disclosure address these and other challenges in current semiconductor manufacturing technology by providing systems and techniques that can efficiently mitigate non-uniform and / or anisotropic stress and deformation in wafers. The quadratic deformation can be expressed as a combination of the parabolic (paraboloidal) part with perfect axisymmetrical TIFF2026506869000006.tif6170180 A saddle-shaped section with discrete symmetries including rotational symmetry and mirror symmetry for reflections in two perpendicular planes It can contain TIFF2026506869000007.tif6170. TIFF2026506869000008.tif6170 Homogeneous (position-independent) axisymmetric strain tensor TIFF2026506869000009.tif11170, where TIFF2026506869000010.tif5170 is the vertical coordinate of the location within the wafer where stress is identified. On the unpatterned backside of the wafer, TIFF2026506869000011.tif5170 here TIFF2026506869000012.tif5170 is the thickness of the wafer. The corresponding strain tensor for parabolic deformation is similarly given by Hooke's law: According to TIFF2026506869000013.tif11170, where TIFF2026506869000014.tif5170 are the Young's modulus and Poisson's ratio of the wafer material, respectively. The uniform strain associated with the parabolic deformation creates a uniform stress on the backside of the membrane that is equal to and opposite to the parabolic stress of the wafer. This can be compensated for by depositing a stress compensation film. TIFF2026506869000016.tif5170 can be calculated (or empirically determined) so that the film applies a desired target stress to the backside of the wafer. For example, TIFF2026506869000017.tif5170 The parabolic curvature of the wafer bends upward, resulting in compression of the top side of the wafer and expansion of the back side of the wafer. Correspondingly, a film that applies a compressive stress to the wafer can be deposited on the back side of the wafer to reduce (or eliminate) the expansion of the back side of the wafer. Conversely, TIFF2026506869000018.tif5170 Backside stretching can be reduced (or eliminated) using a membrane that compresses the backside of the wafer and applies a tensile stress to the backside of the wafer.

[0012] The saddle deformation and stress are non-uniform, e.g., change sign four times around the circumference of the wafer, e.g., Therefore, the parabolic curvature cannot be eliminated by depositing only a stress-compensating film. In some embodiments, the stress-compensating film can be of a thickness and material that not only eliminates the parabolic curvature but also transforms the saddle-shaped deformation into a cylindrical deformation with a consistent sign across the entire area of ​​the wafer. The constant-sign cylindrical deformation (as well as higher-order non-quadratic residual deformations) can then be alleviated by ion implantation into the film. As provided in this disclosure, decomposing the quadratic deformation into parabolic and cylindrical components allows for the identification of an appropriate stress-compensating film. As disclosed in more detail below, such a decomposition is not unique, as the resulting cylindrical deformation can be selected to be positive (upward) or negative (downward). Identifying both of these decompositions allows for the selection of a more effective decomposition for subsequent film deposition and ion implantation.

[0013] In one embodiment, TIFF2026506869000020.tif6170 can be measured using optical metrology techniques. For example, TIFF2026506869000021.tif6170 Optical interferometry measurements can then be obtained through several parameters that qualitatively and quantitatively characterize the geometry of the wafer deformation. TIFF2026506869000022.tif6170. In some embodiments, a set of Zernike (or a similar set) polynomials may be used to represent the wafer profile. TIFF2026506869000023.tif13170 where, TIFF2026506869000024.tif5170 is the radial coordinate in the (mean) plane of the wafer, TIFF2026506869000025.tif5170 Polar coordinates. TIFF2026506869000026.tif6170 compatible The first three coefficients represent the weights of specific geometric features (element deformations) of the wafer described by TIFF2026506869000027.tif6170. No deformation equivalent to a rotation around TIFF2026506869000028.tif6170 This can be eliminated by realigning the coordinate axes and TIFF2026506869000029.tif6170. TIFF2026506869000030.tif5170 without deformation equivalent to rotation around This is of less importance as it explains TIFF2026506869000031.tif6170 (where the Noll notation for Zernike polynomials is used). Associated with TIFF2026506869000032.tif6170, characterizes isotropic parabolic deformations ("curvature"). The coefficients of TIFF2026506869000033.tif5170 are Associated with TIFF2026506869000034.tif6170 and characterizes saddle-shaped deformation. TIFF2026506869000035.tif6170 curved, TIFF2026506869000036.tif6170 characterizes the curved saddle-shaped shape. TIFF2026506869000037.tif6170 curved, TIFF2026506869000038.tif6170 characterizes the curved saddle-shaped shape. TIFF2026506869000039.tif6170 of the wafer along the radial, azimuthal, or both directions. TIFF2026506869000040.tif6170 characterizes the progressively faster fluctuations, collectively 2 represents one actual example of a wafer according to at least one embodiment. TIFF2026506869000042.tif6170 in any unit, An example of Zernike polynomial decomposition 200 is shown in TIFF2026506869000043.tif11170.

[0014] In some embodiments, the stress compensation film 1A-E illustrate a schematic representation of a backside deposited film stress compensation process using additional ion implantation, according to at least one embodiment. FIG. 1A depicts a wafer 102 having deformations, including a parabolic curvature deformation. TIFF2026506869000045.tif6170 and other deformations, such as saddle-shaped deformations and residual deformations (neither of which are shown in FIGS. 1A-1E for brevity and clarity). Wafer 102 has a front side 104 and a back side 106. Front side 104 may have any number of features (e.g., deposition and / or etch patterns), dies, photomasks, and / or any other structures deposited or etched thereon. In some embodiments, back side 106 may be free of deposited / etched features / structures. In some embodiments, back side 106 may also have one or more deposited / etched features / structures. FIG. 1B illustrates a schematic deposition of a stress compensation layer on the back side of wafer 102. In some embodiments, stress compensation layer 108 may include one or more films of different materials. The individual films may have thicknesses ranging from 10 nm to 200 nm, or from 20 nm to 180 nm, or from 30 nm to 160 nm, or from 40 nm to 140 nm, or greater. The total thickness of the stress compensation layer may be up to several microns or greater. In some embodiments, the stress compensation layer 108 is deposited at a temperature ranging from 100° C. to 500° C. or higher.

[0015] The material (type) of the stress compensation layer 108 is You can select based on the code of TIFF2026506869000046.tif6170. For example, The stress compensation layer 108 may be selected to have a tensile stress (as illustrated in FIGS. 1A-E). In the case of a silicon wafer, such a film may be a silicon nitride (Si3N4) film. Conversely, The stress-compensating layer 108 may be selected to have a tensile stress (not shown in FIGS. 1A-E). The stress-compensating layer 108 may be deposited using any suitable deposition technique, including physical vapor deposition (e.g., sputtering), chemical vapor deposition (e.g., plasma-assisted deposition), epitaxy, and / or exfoliation. Deposition may be performed at room temperature or at a temperature different from room temperature (e.g., elevated temperature). In some embodiments, the stress-compensating layer 108 may be deposited using any suitable deposition technique, including physical vapor deposition (e.g., sputtering), chemical vapor deposition (e.g., plasma-assisted deposition), epitaxy, and / or exfoliation. For example, one can choose to overcorrect the deformation to some extent, as shown in Figure 1C, where negative parabolic curvature becomes positive parabolic curvature. TIFF2026506869000050.tif6170 changes to: TIFF2026506869000051.tif5170

[0016] The overcompensation is selected in conjunction with the implant species, energy, and dose to ensure maximum compensation from the stress compensation. The overcompensation allows the combined structure of the wafer 102 and the stress compensation layer 108 to further control the stress (and thus the wafer's TIFF2026506869000052.tif6170). As shown in FIG. 1D, an ion beam implanter 110 can generate an ion beam 112 that bombards the stress-compensating layer 108 and deposits ions therein. The ion beam 112 can carry silicon ions, phosphorus ions, argon ions, neon ions, xenon ions, and / or krypton ions, among others. In some embodiments, the energy and type of ions in the ion beam 112 can be selected to confine the implanted ions to the volume of the stress-compensating layer 108 without allowing the ions to reach the wafer 102. Ions present in the stress-compensating layer 108 create substitutional defects therein. Additionally, the ions leave a trail of vacancy defects along their propagation paths within the stress-compensating layer 108. The substitutional defects and / or vacancies can modify (e.g., reduce) the stress in the stress-compensating layer 108 and reduce the degree of stress overcompensation caused by film deposition. This planarizes the combination of wafer 102 and stress compensation layer 108.

[0017] Specifically, although the stress-relief beam used to modify the stress in the stress-compensating layer 108 is referred to throughout this disclosure as an ion beam (e.g., ion beam 112), the stress-relief beam can include other material particles (e.g., electrons), electromagnetic waves (e.g., UV light, visible light, infrared light, etc.), and / or suitable combinations thereof. The stress-relief beam impinges on the stress-compensating layer 108 and alters the bond network of the stress-compensating layer 108. For example, a low-energy stress-relief beam can interact with surface atoms of the stress-compensating layer 108, e.g., remove some of the surface atoms, effectively etching the surface region of the stress-compensating layer 108. The effectiveness of such etching can be controlled by the selection of ion species / radicals / ambient gas. In another example, a high-energy stress-relief beam can deposit ions within the stress-compensating layer 108. The ions and / or photons can break bonds in the bond network (or crystal lattice) of the stress-compensating layer 108, forming vacancies therein, which can further cause annealing through localized heating, UV curing, and / or other effects.

[0018] In some embodiments, TIFF2026506869000053.tif6170 Saddle deformation, residual deformation, and overcompensation by deposition of stress compensation layer 108 Corrected file that may contain part of TIFF2026506869000054.tif6170 The desired ion distribution can be determined using simulations based on the local values ​​of TIFF2026506869000055.tif6170 (performed as described in more detail below). TIFF2026506869000056.tif6170 Ion beam 112 In some embodiments, the ion beam 112 has a profile that can be approximated by a Gaussian function, for example: TIFF2026506869000058.tif6170. TIFF2026506869000059.tif5170 is in Cartesian coordinates, TIFF2026506869000060.tif5170 is the maximum ion flux at the center of the beam, TIFF2026506869000061.tif5170 respectively, TIFF2026506869000062.tif6170. Correspondingly, from the center path of the beam, The point located at TIFF2026506869000063.tif6170 receives an ion dose containing the following number of ions: TIFF2026506869000064.tif15170 Correspondingly, By lowering the ion beam size, various areas of the stress compensation layer 108 can receive more ions, and vice versa. In addition, the ion beam 112 can be adjusted so that various points of the stress compensation layer 108 can be averaged to the target dose. TIFF2026506869000066.tif6170 to receive multiple ion doses TIFF2026506869000067.tif6170, each from the center of the ion beam 112. TIFF2026506869000068.tif6170Ion beam implantation device 110 After n passes in TIFF2026506869000069.tif6170, the total ion dose received by this area is: As shown in FIG. 1E, implanted layer 114 formed as part of stress compensation layer 108 provides significant mitigation of deformation of wafer 102, particularly its saddle-shaped and residual portions.

[0019] 3 illustrates stress and strain relief 300 in an exemplary wafer using the process disclosed in connection with FIGS. 1A-E, according to at least one embodiment. As shown in FIG. A 30 cm silicon wafer 102 having a TIFF2026506869000071.tif6170 was first prepared using a silicon nitride tensile stress compensation layer 108. The stress in the stress compensation layer 108 is then reduced by forming an implanted layer 114 using an ion beam, and the final maximum deformation is TIFF2026506869000073.tif5170 Figure 4 shows one example profile 400 of a Gaussian ion beam 112 that may be used to relieve stress and deformation in a wafer, according to at least one embodiment.

[0020] The techniques for mitigating distortion and deformation shown in Figures 1 to 3 are: The present invention can also be applied to wafers with complex deformations, such as wafers with different signs, causing the wafer to have a saddle-shaped deformation. Figure 5 shows an example wafer 500 with a saddle-shaped deformation (e.g., a silicon wafer with a silicon nitride film deposited thereon), according to at least one embodiment. TIFF2026506869000075.tif6170 may be lower on the wafer (top layer) than on the film deposited on the backside of the wafer (bottom layer). TIFF2026506869000076.tif6170 may be higher within the wafer than within the film. In some embodiments, the stress state within the wafer can be represented by a position-dependent stress tensor, which can be approximated by the following equation: This structure of the stress tensor is usually a good approximation because the wafer is typically in pure bending and is independent of the shear stresses represented by the off-diagonal terms of the stress tensor. Correction for the saddle shape requires special treatment in the dose map calculation and optimization to ensure that no additional residual terms are introduced into the wafer as a result.

[0021] 6A illustrates an exemplary positive cylindrical decomposition 600 of the quadratic portion of wafer deformation, according to at least one embodiment. As discussed above, wafer deformation can be expressed as, for example, TIFF2026506869000078.tif6170 can be decomposed by Zernike polynomials: TIFF2026506869000079.tif12170 where, TIFF2026506869000080.tif6170, omitted hereafter for brevity and clarity. In equivalent form, the deformation of the wafer is TIFF2026506869000081.tif11170, where The file is TIFF2026506869000082.tif6170. TIFF2026506869000083.tif6170 This is the azimuth angle of the steepest ascent or descent direction of the saddle-shaped portion of TIFF2026506869000084.tif5170. It can be between TIFF2026506869000085.tif6170.

[0022] Cylindrical deformation shapes are characterized by the following deformations: TIFF2026506869000086.tif6170 where, TIFF2026506869000087.tif6170 Cylinder TIFF2026506869000088.tif6170 TIFF2026506869000089.tif6170 Determine the radius of curvature of the cylinder TIFF2026506869000090.tif6170 shows the direction of wafer curvature. Determine TIFF2026506869000091.tif6170; this direction is perpendicular to the axis of the cylinder TIFF2026506869000092.tif6170 Correspondingly, TIFF2026506869000093.tif11170 can be decomposed into variants and combinations: TIFF2026506869000094.tif6170 coefficients This is determined by matching with the Zernike decomposition of TIFF2026506869000095.tif6170. TIFF2026506869000096.tif21170 coefficients Depending on the sign and magnitude of TIFF2026506869000097.tif6170 it can be either positive or negative.

[0023] For simplicity and clarity, the example 600 in FIG. 6A is TIFF2026506869000098.tif6170 shows a wafer deformation 602. Also shown in FIG. 6A is a three-dimensional (3D) view 612 of the deformation 602. As discussed above, the deformation 602 can be decomposed into a negative parabolic deformation 604 (3D view 614) and a positive cylindrical deformation 606 (3D view 616). The positive cylindrical deformation 606 is TIFF2026506869000099.tif6170 has a minimum along the line.

[0024] Alternatively, the same TIFF2026506869000100.tif6170 Parabolic curvature and TIFF2026506869000101.tif6170 can be decomposed into a combination of: TIFF2026506869000102.tif6170Next, TIFF2026506869000103.tif6170 or less is required. Depending on the sign and magnitude of TIFF2026506869000104.tif30170TIFF2026506869000105.tif6170 it can be positive or negative.

[0025] 6B shows an exemplary negative cylindrical decomposition 601 of the quadratic portion of the wafer deformation, according to at least one embodiment. The decomposition 601 in FIG. 6B represents the deformation 602 as the sum of a positive parabolic deformation 605 (3D view 615) and a negative cylindrical deformation 607 (3D view 617). The absolute value of the negative cylindrical deformation 607 is TIFF2026506869000106.tif has a maximum value along 5170.

[0026] For wafers with arbitrary parabolic curvature and arbitrary saddle-shaped orientation, the positive cylindrical decomposition TIFF2026506869000107.tif6170 and negative cylindrical decomposition TIFF2026506869000108.tif6170 can be evaluated, allowing the more optimal decomposition to be selected. TIFF2026506869000109.tif6170 selection smaller For example, the smaller resolution may include identifying a resolution with a value of TIFF2026506869000110.tif6170. Once the decomposition with TIFF2026506869000111.tif6170 is selected, TIFF2026506869000112.tif5170 can be evaluated. TIFF2026506869000113.tif5170A tensile stress compensation film that compresses the backside of the wafer can be selected. TIFF2026506869000114.tif5170 A compressive stress compensation film can be selected that tensions the backside of the wafer. In some embodiments, certain types of films may be preferred, e.g., a tensile film may be preferred over a compressive film (or vice versa). In such cases, the corresponding sign TIFF2026506869000115.tif5170 Such a code TIFF2026506869000116.tif5170 decomposition can be selected. (If both TIFF2026506869000117.tif5170 have the same sign, the decomposition with the smaller value may be preferred).

[0027] In some embodiments, the strength of the stress compensation film is For the reasons mentioned above, it may be advantageous to ensure that the signs of the film-corrected deformations of the wafer are the same. For example, a particular type and The film in TIFF2026506869000119.tif5170 prevents wafer deformation. When corrected by TIFF2026506869000120.tif6170, the total corrected deformation of the wafer after film deposition can be: TIFF2026506869000121.tif6170In one example, the wafer TIFF2026506869000122.tif6170 and the film is determined to be of a type that causes stretching of the backside of the wafer. TIFF2026506869000123.tif6170 The film thickness can be chosen so that the following holds: TIFF2026506869000124.tif5170This resulted in film correction for the entire backside area of ​​the wafer. TIFF2026506869000125.tif6170 is definitely done. In particular, If the film is selected to be TIFF2026506869000126.tif5170, the deformation of the wafer will be TIFF2026506869000127.tif6170 Along other lines Overcorrected by TIFF2026506869000128.tif6170, The overcompensation is then addressed by targeted ion implantation to relax the strain in the stress compensation film, e.g., the maximum implantation of ions is The minimum ion injection point is near TIFF2026506869000130.tif6170. This occurs near TIFF2026506869000131.tif5170, where TIFF2026506869000132.tif5170 is the radius of the wafer.

[0028] In some embodiments, the quadratic deformation of the wafer can be quantitatively characterized by the degree to which parabolic and cylindrical deformations coexist. In one non-limiting embodiment, a "cylindrical" polynomial can be introduced (with the same normalization as the Zernike polynomials): TIFF2026506869000133.tif7170The quadratic deformation can be expressed as follows: TIFF2026506869000134.tif12170 Correspondingly, the value TIFF2026506869000135.tif22170 can be called the parabolicity of the wafer, while the value TIFF2026506869000136.tif22170 can be referred to as the cylindrical nature of the wafer. In some embodiments, the type and thickness of the stress compensation film can be determined by: TIFF2026506869000137.tif5170 can be determined directly.

[0029] FIG. 7 is a flow diagram illustrating an exemplary process 700 for mitigating wafer deformation using cylindrical decomposition, according to at least one embodiment. Process 700 can be performed using a semiconductor manufacturing system including one or more processing chambers, such as one or more deposition chambers, one or more plasma chambers, one or more etching chambers, one or more polishing chambers, one or more film removal chambers, one or more beam irradiation chambers, and / or one or more optical inspection chambers. The processing chambers can be connected to one or more transfer chambers, which can include one or more robots for handling wafers, e.g., transferring wafers into and out of the processing chambers. The transfer chambers can further be connected to a load lock chamber (front-end interface), which can couple to one or more Front Opening Unified Pod (FOUP) carriers that hold bare wafers, processed wafers, and / or partially processed wafers. The operations performed by the semiconductor manufacturing system, including any, some, or all of the steps of process 700, can be performed in response to instructions issued by a suitable computing device having a memory for storing processing logic and instructions.

[0030] In block 710, the process 700 calculates the shape of the wafer, e.g., the displacement of the surface (e.g., the top surface) of the wafer, in any suitable in-plane coordinate, e.g., TIFF2026506869000138.tif6170 or some other coordinate function. At block 720, process 700 expresses the determined shape via a suitable set of polynomials, e.g., Zernike polynomials, TIFF2026506869000139.tif6170, where each coefficient in the set characterizes the abundance of a particular element's geometry in the wafer deformation.

[0031] In block 730, for example, these Using TIFF2026506869000140.tif6170, a decomposition of the wafer deformation can be obtained as the sum of at least parabolic and cylindrical deformations. The resulting cylindrical decomposition can include a positive cylindrical decomposition and a negative cylindrical decomposition. In block 740, the resulting cylindrical decompositions can be evaluated, and a preferred cylindrical decomposition can be selected for implementation via film deposition. The preferred cylindrical decomposition can be selected based on various metrics. For example, a cylindrical decomposition requiring the least corrective parabolic curvature (still maintaining the same sign of stress across the entire area of ​​the wafer) can be selected; a cylindrical decomposition requiring a particular type of film (e.g., tensile or compressive film) can be selected; and / or a cylindrical decomposition that is most aligned (or misaligned) with a particular feature patterned on the top side of the wafer can be selected.

[0032] At block 750, the process 700 may proceed to identify characteristics (e.g., material type, thickness, etc.) of a target stress compensation layer (film) to be deposited on the wafer. At block 760, the process 700 may include depositing a film on the wafer made from a selected material and having a selected thickness. The deposited film may induce a stress tensor in the new wafer plus film structure of a particular sign (positive or negative). This is advantageous because subsequent ion implantation can reduce the amount of stress in the film, whereas it may be more difficult to reverse the sign of the stress in the film with ion implantation (e.g., turning a tensile film into a compressive film).

[0033] At block 780, the process 700 can proceed to determining an appropriate dose for ion (electron, photon, etc.) implantation. In some embodiments, the ion implantation dose can be determined, for example, based on the selected and applied cylindrical decomposition dose. TIFF2026506869000141.tif6170 and / or an appropriate combination of Zernike coefficients The ion implantation dose can be determined based on the saddle-shaped component (and / or remaining parabolic component) of wafer deformation that has not been eliminated by film deposition, such as given by TIFF2026506869000142.tif11170. In some embodiments, the ion implantation dose can be further selected to eliminate (or reduce) higher order residual deformation.

[0034] In some embodiments, the steps of block 780 can be performed based on wafer deformation data acquired in block 710 prior to film deposition. In some embodiments, the steps of block 780 can be performed based on new data acquired after film deposition by re-measuring the corrected (film-induced) deformation of the wafer (block 770). In block 790, ion implantation is performed, for example, by exposing the film to a stress relief beam (e.g., an ion beam), as disclosed in conjunction with FIGS. 8A-B below. As indicated by the dashed arrows in FIG. 7, blocks 770-790 of process 700 can be repeated iteratively until the stress or deformation of the wafer is reduced below the target tolerance.

[0035] FIG. 8A schematically illustrates an ion implantation system 800 capable of performing ion implantation into a stress-compensating layer, according to at least one embodiment. The ion implantation system 800 may be or may include the ion beam implanter 110 of FIG. 1. Specifically, although the stress-relief beam used to modify the stress in the stress-compensating layer 108 is referred to in some embodiments as an ion beam (e.g., ion beam 112), the stress-relief beam may include other material particles (e.g., electrons), electromagnetic waves (e.g., UV light, visible light, infrared light, etc.), and / or suitable combinations thereof. The ion implantation system 800 may include an ion source 802 for generating an ion beam 804. The ion source 802 may include a chamber (e.g., a plasma chamber) for generating ions. The ion source 802 may be powered by a power supply 806 and may include an extraction electrode assembly (not shown). The ion implantation system 800 may include a mass analyzer 808 and a collimating and focusing column 810. The collimating and focusing column 810 can direct the ion beam 112 toward the wafer 102. The wafer 102 can be supported by a support stage 812. In some embodiments, the support stage 812 and wafer 102 can remain stationary while the ion beam 112 scans the wafer 102, but components of the ion implantation system 800 can be repositioned relative to the wafer 102. In some embodiments, the ion implantation system 800 can be stationary, but the support stage 812 can reposition the wafer 102. The scanning by the ion beam 112 can be along multiple directions according to any suitable predetermined pattern, for example, TIFF2026506869000143.tif6170 For example, TIFF2026506869000144.tif5170 and spiral patterns, etc. In various embodiments, the ion beam 112 can be scanned at a frequency of a few Hz, tens of Hz, hundreds of Hz, thousands of Hz, or greater.

[0036] Operation of the ion implantation system 800 can be controlled by a controller 814, which can include any suitable computing device having a processor, such as a central processing unit (CPU), field programmable gate array (FPGA), and / or application specific integrated circuit (ASIC), microcontroller, or other processing device, and memory devices, such as random access memory (RAM), read-only memory (ROM), and / or flash memory, or any combination thereof. The controller 814 can control the operation of the power supply 806, the support stage 812, and / or various other components and modules of the ion implantation system 800. The controller 814 can include an ion beam simulation module 816 that can perform simulations to determine target intensities of the ion beam 112 used to mitigate various wafer deformations. In some embodiments, the support stage 812 can be tilted, for example, in one or two spatial directions relative to the wafer 102 to vary the angle of incidence of the ion beam 112 with respect to the wafer 102. In some embodiments, instead of tilting the wafer 102, the controller 814 can tilt the ion implantation system 800 relative to the wafer 102. In some embodiments, for example, as shown in FIG. 8B , the support stage 812 can impart tilt in one or two spatial directions relative to the wafer 102, for example, to change the angle of incidence of the ion beam 112 relative to the wafer 102. In some embodiments, instead of tilting the wafer 102, the controller 814 can tilt the ion implantation system 800 relative to the wafer 102.

[0037] FIG. 9 illustrates a block diagram of an exemplary computer system 900 capable of supporting operations of the present disclosure, according to at least one embodiment. In various examples, the exemplary computer system 900 may be the controller 814 of FIG. 8 or may include the controller 1114. The computer system 900 may be connected to other computer systems in a local area network (LAN), an intranet, an extranet, and / or the Internet. The computer system 900 may operate in a server capacity in a client-server network environment. The computer system 900 may be a personal computer (PC), a set-top box (STB), a server, a network router, switch, or bridge, or any device capable of executing a set of instructions (sequential or otherwise) that specify operations to be performed by the device. Furthermore, while only a single exemplary computer system is shown, the term “computer” should also be understood to include any collection of computers that, individually or collectively, execute an instruction set (or sets of instructions) to perform any method or methods described herein.

[0038] The exemplary computer system 900 may include a processing device 902 (also referred to as a processor or CPU), which may include processing logic 926, a main memory 904 (e.g., read-only memory (ROM), flash memory, dynamic random access memory (DRAM), such as synchronous DRAM (SDRAM), etc.), a static memory 906 (e.g., flash memory, static random access memory (SRAM), etc.), and a secondary memory (e.g., data storage device 918), which may communicate with each other via a bus 930.

[0039] Processing device 902 represents one or more general-purpose processing devices, such as a microprocessor or central processing unit. Specifically, processing device 902 may be a complex instruction set computing (CISC) microprocessor, a reduced instruction set computing (RISC) microprocessor, a very long instruction word (VLIW) microprocessor, a processor implementing other instruction sets, or a processor implementing a combination of instruction sets. Processing device 902 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), or a network processor. According to one or more aspects of the present disclosure, processing device 902 may be configured to execute instructions implementing an example process 700 for mitigating wafer deformation using cylindrical decomposition.

[0040] The exemplary computer system 900 may further include a network interface device 908 that may be communicatively coupled to a network 920. The exemplary computer system 900 may further include a video display 910 (e.g., a liquid crystal display (LCD), touch screen, or cathode ray tube (CRT)), an alphanumeric input device 912 (e.g., a keyboard), a cursor control device 914 (e.g., a mouse), and an audio signal generating device 916 (e.g., a speaker).

[0041] The data storage device 918 may include a computer-readable storage medium (or more specifically, a non-transitory computer-readable storage medium) 924 having stored thereon one or more sets of executable instructions 922. According to one or more aspects of the present disclosure, the executable instructions 922 may include executable instructions that implement the example process 700 for mitigating wafer deformation using cylindrical decomposition.

[0042] The executable instructions 922 may also reside, completely or at least partially, within main memory 904 and / or processing device 902 during execution by exemplary computer system 900, with main memory 904 and processing device 902 also constituting computer-readable storage media. The executable instructions 922 may also be transmitted or received over a network via network interface device 908.

[0043] While computer-readable storage medium 924 is shown in Figure 9 as a single medium, the term "computer-readable storage medium" should be interpreted to include a single medium or multiple media (e.g., a centralized or distributed database, and / or associated caches and servers) that store one or more sets of operating instructions. The term "computer-readable storage medium" should also be interpreted to include any medium that can store or encode a set of instructions that are executed by a machine, causing the machine to perform any one or more of the methodologies described herein. Accordingly, the term "computer-readable storage medium" should be interpreted to include, but is not limited to, solid-state memory and optical and magnetic media.

[0044] Some portions of the foregoing detailed descriptions 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 invention 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. These steps are steps 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.

[0045] It should be noted, however, that all of these and similar terms should be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. As will become apparent from the following description, unless otherwise specified, throughout this description, descriptions utilizing terms such as "identifying," "determining," "storing," "adjusting," "causing," "returning," "comparing," "creating," "stopping," "loading," "copying," "throwing," "replacing," or "performing" should be understood to refer to the operations and processes of a computer system or similar electronic computing device. Such a computer system or similar electronic computing device manipulates and converts data represented as physical (electronic) quantities in the computer system's registers and memory into other data represented as physical (electrical) quantities in the computer system's memory or registers or such other information storage, transmission, or display device.

[0046]

[0010] Embodiments of the present disclosure also relate to 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 on a computer-readable storage medium, such as any type of disk including, but not limited to, optical disks, CD-ROMs, and magneto-optical disks, read-only memory (ROM), random-access memory (RAM), EPROM, EEPROM, magnetic disk storage media, optical storage media, flash memory devices, other types of machine-accessible storage media, or any type of medium suitable for storing electronic instructions, each coupled to a computer system bus.

[0047] 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 more specialized apparatus to perform the required method steps. The required structure for a variety of such systems will be apparent as set forth in the description below. Additionally, the scope of the present disclosure is not limited to any particular programming language. It will be understood that a variety of programming languages ​​can be used to implement the teachings of the present disclosure.

[0048] It should be understood that the above description is intended to be illustrative, not limiting. Many other exemplary embodiments will be apparent to those skilled in the art upon reading and understanding the above description. While particular examples have been described in the present disclosure, it will be recognized that the systems and methods of the present disclosure are not limited to the examples described herein, but can be practiced with modification within the scope of the claims. Accordingly, the specification and drawings are to be regarded in an illustrative, rather than limiting 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.

Claims

1. 1. A method for correcting out-of-plane deformation (OPD) of a substrate, comprising: obtaining an OPD profile of the substrate using the optical inspection data; obtaining a polynomial representation of the OPD profile to determine a plurality of polynomial coefficients, each of the plurality of polynomial coefficients characterizing a respective one of a plurality of elementary deformation shapes of the substrate; determining one or more cylindrical decompositions of a quadratic portion of the OPD profile based on at least a subset of the plurality of polynomial coefficients, wherein each of the one or more cylindrical decompositions includes decomposing the OPD profile into at least a parabolic deformation of the substrate and a cylindrical deformation of the substrate; calculating one or more characteristics of a stress compensation layer (SCL) for the substrate using a selected one of the one or more cylindrical decompositions; depositing the SCL onto the substrate; exposing the SCL to a stress relaxation beam; A method comprising:

2. The method of claim 1 , wherein the polynomial representation of the OPD profile comprises an expansion of the OPD profile in terms of Zernike polynomials.

3. the one or more cylindrical decompositions a first cylindrical decomposition including an upward cylindrical component relative to the OPD of the substrate; and a second cylindrical decomposition including a downward cylindrical component relative to the OPD of the substrate; The method of claim 1 , comprising:

4. 4. The method of claim 3, wherein the selected cylindrical decomposition comprises a parabolic component for the OPD of the substrate having a smaller magnitude among the parabolic components for the OPD of the one or more cylindrical decompositions.

5. The method of claim 3 , wherein the selected cylindrical decomposition is related to a direction of patterning of the substrate.

6. The method of claim 1 , wherein the one or more characteristics of the SCL are calculated such that stress in the substrate has the same sign throughout an area of ​​the substrate.

7. The one or more features of the SCL are: the material of the SCL, or The thickness of the SCL The method of claim 1 , comprising one or more of:

8. The stress relaxation beam is configured as follows: the type of particles in the stress relaxation beam; the energy of the particles of the relaxation beam, or the angle of incidence of the particles of the stress relaxation beam on the SCL; The system of claim 1 , comprising one or more of:

9. obtaining an updated OPD profile of the substrate in response to exposing the SCL to the stress relaxation beam; Mapping residual stress in the substrate based on the updated OPD profile; and identifying additional stress relief beam settings based on the mapped residual stresses; and exposing one or more regions of the SCL to the additional stress relief beam; The method of claim 1 further comprising:

10. The method of claim 1 , wherein the substrate includes a front side and a back side, the front side including one or more fabricated features, and the SCL is deposited on the back side of the substrate.

11. Memory and a processing device communicatively coupled to the memory; a processing device for processing a signal from the processing device; obtaining an OPD profile of the substrate using the optical inspection data; obtaining a polynomial representation of the OPD profile to determine a plurality of polynomial coefficients, each of the plurality of polynomial coefficients characterizing a respective one of a plurality of elementary deformation shapes of the substrate; determining one or more cylindrical decompositions of a quadratic portion of the OPD profile based on at least a subset of the plurality of polynomial coefficients, wherein each of the one or more cylindrical decompositions includes decomposing the OPD profile into at least a parabolic deformation of the substrate and a cylindrical deformation of the substrate; calculating one or more characteristics of a stress compensation layer (SCL) for the substrate using a selected one of the one or more cylindrical decompositions; depositing the SCL onto the substrate; exposing the SCL to a stress relaxation beam; A system that performs the following:

12. The system of claim 11 , wherein the polynomial representation of the OPD profile comprises an expansion of the OPD profile in terms of Zernike polynomials.

13. the one or more cylindrical decompositions a first cylindrical decomposition including an upward cylindrical component relative to the OPD of the substrate; and a second cylindrical decomposition including a downward cylindrical component relative to the OPD of the substrate; The system of claim 11 , comprising:

14. 14. The system of claim 13, wherein the selected cylindrical decomposition includes a parabolic component for the OPD of the substrate having a smaller magnitude among the parabolic components for the OPD of the one or more cylindrical decompositions.

15. The system of claim 13 , wherein the selected cylindrical decomposition is associated with a direction of patterning of the substrate.

16. The system of claim 11 , wherein the one or more characteristics of the SCL are calculated such that stress in the substrate has the same sign throughout an area of ​​the substrate.

17. The one or more features of the SCL are: the material of the SCL, or The thickness of the SCL [0033] The stress relaxation beam is configured as follows: the type of particles in the stress relaxation beam; the energy of the particles of the relaxation beam, or the angle of incidence of the particles of the stress relaxation beam on the SCL; The system of claim 11 , comprising one or more of:

18. the processing device further comprising: obtaining an updated OPD profile of the substrate in response to exposing the SCL to the stress relaxation beam; Mapping residual stress in the substrate based on the updated OPD profile; and identifying additional stress relief beam settings based on the mapped residual stresses; and exposing one or more regions of the SCL to the additional stress relief beam; The system of claim 11 , wherein the system performs the following:

19. 12. The system of claim 11, wherein the substrate includes a front side and a back side, the front side including one or more fabricated features, and the SCL is deposited on the back side of the substrate.

20. 1. A semiconductor manufacturing system, comprising: one or more processing chambers for processing substrates; 1. A computing device, comprising: obtaining an OPD profile of the substrate using the optical inspection data; obtaining a polynomial representation of the OPD profile to determine a plurality of polynomial coefficients, each of the plurality of polynomial coefficients characterizing a respective one of a plurality of elementary deformation shapes of the substrate; determining one or more cylindrical decompositions of a quadratic portion of the OPD profile based on at least a subset of the plurality of polynomial coefficients, wherein each of the one or more cylindrical decompositions includes decomposing the OPD profile into at least a parabolic deformation of the substrate and a cylindrical deformation of the substrate; calculating one or more characteristics of a stress compensation layer (SCL) for the substrate using a selected one of the one or more cylindrical decompositions; depositing the SCL onto the substrate; exposing the SCL to a stress relaxation beam; A computing device that performs the following: A semiconductor manufacturing system comprising:

Images