Polymer back film layer for alleviating substrate warpage

Abstract

An article includes a substrate, such as a semiconductor wafer, having a back side, and a back side film layer deposited on the back side of the substrate, where the back side film layer includes a polymer. The back side film layers mitigate bending or warping of the substrate, which occurs when one or more front side film layers are deposited on the front side of the substrate. To form the back side film layer, a film composition may be deposited on the back side of the substrate, the film composition comprising a polymer, optionally a wetting agent, and optionally a solvent.

Description

[0001] Claiming priority

[0002] This application claims priority to U.S. Provisional Patent Application Serial No. 63 / 348,824 (Agency File No. 1202206-US-F), filed on June 3, 2022, which is incorporated herein by reference in its entirety. Technical Field

[0003] The present disclosure relates to polymer film layers deposited on the back side of a substrate, such as a semiconductor wafer. More specifically, a polymer backside film layer may be deposited on the back side of a substrate as a means of alleviating bowing or warping that may occur when one or more frontside film layers are deposited on the front side of the substrate, such as during semiconductor device manufacturing operations. Background Art

[0004] Semiconductor device manufacturing involves deposition and etching operations, which are usually performed on the front side of the wafer. As the deposited layers accumulate, they can introduce stress into the wafer, causing the wafer to bow or warp. While traditional backside deposition techniques can deposit materials with desired film stress on the back side of the wafer to counteract wafer bow or warp, traditional backside deposition techniques may require specialized deposition equipment, which can increase cost and / or introduce complexity.

[0005] Therefore, there is a need for new, more cost-effective solutions for providing backside support for substrates such as semiconductor wafers as a means of mitigating bowing or warping during operations such as semiconductor device manufacturing. Summary of the invention

[0006] Embodiments of the present disclosure are directed to articles and methods involving a backside film layer comprising a polymer and deposited on the backside of the substrate.

[0007] According to some embodiments, an article is provided, wherein the article comprises a substrate having a back side, and a back side film layer deposited on the back side of the substrate, wherein the back side film layer comprises a polymer.

[0008] According to other embodiments, a method for processing a substrate is provided. The method comprises the following steps: depositing a film composition on the back side of the substrate to form a back side film layer. The film composition comprises a polymer, an optional wetting agent, and an optional solvent.

[0009] Additional features and advantages of these and other embodiments will be set forth in the Detailed Description which follows, and in part will be apparent to those skilled in the art from the Detailed Description, or may be recognized by practicing the embodiments described herein, including the Detailed Description and the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a schematic diagram of an exemplary article according to one or more embodiments shown and described herein; and

[0011] Figure 2 is a flow chart of an exemplary method for processing a substrate according to one or more embodiments shown and described herein. DETAILED DESCRIPTION

[0012] Various examples of articles and methods are referenced in detail below, including articles and methods involving a backside film layer comprising a polymer and deposited on the backside of a substrate.

[0013] The disclosure should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the subject matter to those skilled in the art.

[0014] definition

[0015] Unless otherwise specifically defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terms used in the disclosure herein are only used to describe specific embodiments and are not intended to be limiting.

[0016] Unless expressly stated otherwise, it is intended that any method disclosed herein be construed as requiring that its steps be performed in a specific order, nor that any apparatus described herein be construed as requiring a specific order or orientation of its components.

[0017] Unless expressly stated otherwise, any composition or mixture disclosed herein can comprise, consist essentially of, or consist of the disclosed components.

[0018] As used herein, the singular form of a term is intended to include the plural form of the term unless the context clearly indicates otherwise.

[0019] As used herein, numerical values ​​are not strictly limited to the exact numerical values ​​described. Instead, unless otherwise expressly stated, each numerical value is intended to represent the exact numerical value and the encompassed "about" numerical value (i.e., the functionally equivalent range around the numerical value), so that any possibility is conceivable as an embodiment disclosed herein.

[0020] As used herein, the terms "backside" and "frontside" refer to different and opposite sides of a substrate. The front side is the first side of the substrate. For example, when the substrate is a semiconductor wafer, the front side is typically subjected to most of the deposition and etching operations during semiconductor manufacturing and is where semiconductor devices are manufactured. The back side is the second and opposite (i.e., opposite to the front side) side of the substrate. For example, when the substrate is a semiconductor wafer, the back side is typically subjected to little or no deposition and etching operations during semiconductor manufacturing.

[0021] As used herein, the terms "bow" and "bowing" refer to the deviation of the center point of the median surface of a free, unclamped wafer from a reference plane, as determined in accordance with ASTM F534-97.

[0022] As used herein, the term "desired film stress" refers to a film stress of the backside film layer that results in a bow of less than about 100 μm in a substrate on which the backside film layer is deposited.

[0023] As used herein, the term "film composition" refers to a substance (e.g., a polymer) or a mixture of two or more substances (e.g., a polymer and at least one of a solvent and a wetting agent, etc.) used to form or grow a back film layer on the back side of the substrate. The film composition may be in the form of a solution, such as a liquid solution.

[0024] As used herein, the term "film stress" refers to the stress in a film layer, which is determined according to ASTM E1426-14 and ASTM E915-16.

[0025] As used herein, the term "glass transition temperature" refers to the temperature at which an amorphous material (or an amorphous region of a semi-crystalline material) undergoes a glass-liquid transition (T g ), which is determined according to ASTM D3418.

[0026] As used herein, the terms "substrate" and "wafer" are interchangeable. One of ordinary skill in the art will appreciate that the embodiments described herein may be used before or during any other processing operations on a semiconductor wafer during any of the multiple stages of semiconductor device and / or integrated circuit fabrication.

[0027] As used herein, the term "tensile modulus" or "Young's modulus" refers to a mechanical property (E) of a material that characterizes its stiffness and is quantified as the ratio of the material's tensile stress (σ) to its tensile strain (ε) when elastically deformed, as measured in accordance with ASTM D882-18.

[0028] As used herein, the terms "warp" or "warpage" refer to the difference between the maximum and minimum distances of the mid-surface of a free, unclamped wafer from a reference plane, as measured according to ASTM F1390.

[0029] utility

[0030] As mentioned above, semiconductor manufacturing operations involve forming a variety of structures, many of which may be two-dimensional. As semiconductor device dimensions shrink and device scales become smaller, feature density on semiconductor substrates increases, resulting in material layers being etched and deposited in various ways, including in three dimensions. For example, 3D-NAND is an increasingly popular technology because it has lower costs, higher memory density, and higher reliability in various applications compared to other technologies such as 2D-NAND.

[0031] In 3D-NAND memory device manufacturing, multiple stacked films with thick and high stress deposition are applied, which can lead to significant wafer warpage, resulting in in-plane-distortion (IPD) and defocus problems in the ArF lithography process. Currently, the only solution is backside deposition by plasma-enhanced chemical vapor deposition (PECVD) method. However, this technology disadvantageously requires specialized deposition equipment, resulting in a greater cost burden for integrated circuit (IC) manufacturing plants.

[0032] The articles and methods disclosed herein alleviate the above-mentioned problems.

[0033] The article disclosed herein comprises a substrate having a back side, and a back side film layer deposited on the back side of the substrate, wherein the back side film layer comprises a polymer. To form the back side film layer, a film composition can be deposited on the back side of the substrate, the film composition comprising the polymer, optionally a wetting agent, and optionally a solvent.

[0034] The method for processing a substrate disclosed herein comprises the following steps: depositing a film composition on the back side of the substrate to form a back side film layer. The film composition comprises a polymer, an optional wetting agent, and an optional solvent.

[0035] The film compositions disclosed herein can be deposited without the need for specialized deposition techniques or equipment while achieving a desired film stress in the resulting backside film layer to mitigate warpage during processes such as semiconductor device and / or integrated circuit manufacturing operations.

[0036] Products

[0037] The article disclosed herein comprises: a substrate having a back side, and a back side film layer deposited on the back side of the substrate, wherein the back side film layer comprises a polymer. To form the back side film layer, a film composition can be deposited on the back side of the substrate, the film composition comprising a polymer, an optional wetting agent, and an optional solvent.

[0038] In embodiments, the article may be a partially or fully fabricated semiconductor device, such as a partially or fully fabricated integrated circuit.

[0039] Substrate

[0040] Reference Figure 1 , the article 100 disclosed herein includes a substrate 102 having a back side 104 and a front side 106 opposite to the back side 104 .

[0041] In an embodiment, the substrate 102 may include a semiconductor material. In an embodiment, the semiconductor material may be selected from any known semiconductor material. In an embodiment, the semiconductor material may be selected from at least one of silicon (Si), silicon carbide (SiC), gallium arsenide (GaAs), gallium nitride (GaN), and germanium (Ge).

[0042] In embodiments, the substrate may be substantially circular and have a diameter of 200 mm, 300 mm, or 450 mm.

[0043] Back film layer

[0044] A backside film layer 108 is deposited on the backside 104 of the substrate 102 to counteract stress and resulting bowing or warping caused by depositing layers on the frontside 106 of the substrate 102 .

[0045] In order to form the back film layer 108, a film composition may be deposited on the back side of the substrate. As described elsewhere herein, the film composition may include, consist essentially of, or consist of a polymer, optionally a wetting agent, and optionally a solvent. In some embodiments, the solvent in the film composition may be removed during processing (e.g., by drying) to promote the formation of the back film layer 108. Therefore, the back film layer 108 may include a polymer, optionally a wetting agent, and optionally a solvent. In an embodiment, after the drying process, there may be no solvent in the back film layer 108, or there may be a solvent in the back film layer 108 that does not exceed the acceptable minimum residual solvent amount. For example, in an embodiment, the acceptable minimum residual solvent amount may be less than or equal to about 0.6% by weight, based on the total weight of the back film layer (i.e., the dried film composition).

[0046] The optimal thickness of the back film layer 108 may depend on the specific formulation of the film composition used to form the back film layer 108, and / or the amount of stress induced by the deposition on the front side 106 of the substrate 102. The back film layer 108 may be deposited to a thickness at which the wafer bow becomes negligible (e.g., less than about 100 μm of bow). The total thickness of the back film layer 108 may be achieved by depositing a single layer (e.g., up to 20 μm) or by depositing multiple laminated layers (e.g., up to 50 μm) to form the back film layer 108.

[0047] For example, in an embodiment, the thickness of the back film layer 108 may be less than or equal to 50 μm, 30 μm, 20 μm, 10 μm, 8 μm, 5 μm, 3 μm, or 1 μm; and greater than or equal to 0.5 μm or 0.7 μm. Therefore, in an embodiment, the thickness of the back film layer 108 may be 0.5μm to 50μm, 0.5μm to 30μm, 0.5μm to 20μm, 0.5μm to 10μm, 0.5μm to 8μm, 0.5μm to 5μm, 0.5μm to 2μm, 0.5μm to 1μm, 0.7μm to 50μm, 0.7μm to 30μm, 0.7μm to 20μm, 0.7μm to 10μm, 0.7μm to 8μm, 0.7μm to 5μm, 0.7μm to 3μm, 0.7μm to 1μm, or any and all sub-ranges formed by any of these endpoints.

[0048] As described herein, the back film layer 108 should have a tensile modulus that counteracts bending or warping caused by depositing layers on the front side 106 of the substrate 102. For example, in embodiments, the tensile modulus of the back film layer 108 may be greater than 1 GPa, 2 GPa, or 3 GPa. In embodiments, the tensile modulus of the back film layer 108 may be from about 1 GPa to about 2.5 GPa, or from about 1 GPa to about 2.4 GPa, or from about 1 to about 2.3 GPa.

[0049] In an embodiment, the back film layer 108 may include a blend of polyamide-imide (PAI) and polyimide (PI) in a weight ratio of about 19:1 to about 4:1 (e.g., about 15:1), and the glass transition temperature of the blend is about 230°C to about 295°C (e.g., about 291°C).

[0050] Film composition

[0051] To form the backside film layer, a film composition may be deposited on the backside of the substrate.

[0052] In an embodiment, the film composition may include a polymer, an optional wetting agent, and an optional solvent. In an embodiment, the film composition may include a polymer, and at least one of a wetting agent and a solvent. In an embodiment, the film composition may include a polymer, a solvent, and an optional wetting agent, and may be used in the form of a solution (such as a liquid solution).

[0053] In an embodiment, the viscosity of the film composition may be about 100 cP to about 27000 cP when measured at 25° C. However, the viscosity may be adjusted so as not to exceed the maximum viscosity at which a conventional spin coating device can operate, which in an embodiment may be about 8000 cP when measured at 25° C. Therefore, in an embodiment, the viscosity of the film composition may be about 100 cP to about 8000 cP when measured at 25° C. With a viscosity in this range, it may be possible to achieve good coating of the film composition onto the back side of the substrate using a conventional spin coating device.

[0054] polymer

[0055] The back film layer 108 comprises a polymer that allows the film composition to be deposited to form the back film layer 108 without the need for specialized deposition equipment while achieving desired film stress. For example, in a photolithography process, a film composition comprising the polymer can be deposited using conventional spin coater equipment and baking equipment. The polymer also allows relatively easy removal of the back film layer 108 after further processing using conventional spin coater equipment and sufficient solvent.

[0056] In some embodiments, the polymer may comprise a single type of polymer. In other embodiments, the polymer may comprise a blend of two or more different types of polymers.

[0057] In an embodiment, the polymer may be selected from at least one of the following: polybenzimidazole (PBI), polyetherimide (PEI), polyamide-imide (PAI), polyimide (PI), polysulfone (PSU), polyphenylsulfone (PPSU), polyethersulfone (PES), and polybenzoxazole (PBO). For example, in some embodiments, particularly suitable polymers include at least one of polyamide-imide (PAI), polyimide (PI), polyphenylsulfone (PPSU), and polyethersulfone (PES).

[0058] In an embodiment, the polymer may include: a blend of polyimide (PI) and polybenzimidazole (PBI); or a blend of polysulfone (PSU) and polybenzoxazole (PBO); or a blend of polysulfone (PSU) and polyimide (PI); or a blend of polyamide-imide (PAI) and polyimide (PI); or a blend of polyimide (PI) with at least one of polyamide-imide (PAI), polyimide (PI), and polyetherimide (PEI); or a blend of polysulfone (PSU) with at least one of polyimide (PI), polyetherimide (PEI), and polyamide-imide (PAI); or a blend of polyimide (PI), polyamide-imide (PAI), and polyetherimide (PEI); or a blend of polyamide-imide (PAI), polyimide (PI), and polyethersulfone (PES). For example, in some embodiments, particularly suitable polymers include binary blends of polyamide-imide (PAI) and polyimide (PI); and ternary blends of polyamide-imide (PAI) and polyimide (PI) and polyethersulfone (PES).

[0059] In embodiments where the polymer comprises two or more different polymers, the polymers may be used as a blend in a suitable weight ratio.

[0060] In embodiments where the polymer comprises a binary blend of a first polymer and a second polymer, the weight ratio of the first polymer to the second polymer may be, for example, 95:5, 85:15, 80:20, 60:40, 50:50, and 40:60.

[0061] For example, in some embodiments where the polymer comprises a binary blend of polyamide-imide (PAI) and polyimide (PI), the weight ratio of PAI to PI can be 499:1 to 1:4, such as 499:1, 249:1, 166:1, 124:1, 99:1, 19:1, 15:1, 17:3, 4:1, 3:2, 1:1, 2:3, or 1:4.

[0062] In embodiments where the polymer comprises a ternary blend of a first polymer, a second polymer, and a third polymer, the weight ratio of the first polymer to the second polymer to the third polymer may be, for example, 60:15:25, 40:10:50, and 20:5:75.

[0063] For example, in some embodiments where the polymer comprises a ternary blend of polyamide-imide (PAI), polyimide (PI), and polyethersulfone (PES), the weight ratio of PAI to PI to PES may be 12:3:5, 4:1:5, or 4:1:15.

[0064] In embodiments where a solvent is included in the film composition, the amount of polymer in the film composition may be greater than or equal to 1 wt%, 2 wt%, 5 wt%, or 10 wt%, based on the total weight of the film composition; and less than or equal to 50 wt%, 45 wt%, or 40 wt%. Thus, in embodiments, the amount of polymer in the film composition may be 1 wt% to 50 wt%, 2 wt% to 50 wt%, 5 wt% to 45 wt%, 10 wt% to 40 wt%, or any and all subranges formed by any of these endpoints, based on the total weight of the film composition.

[0065] In embodiments where no solvent is included in the film composition, the amount of polymer in the film composition can be 99 wt % to 100 wt %, 99.5 wt % to 100 wt %, 99.8 wt % to 100 wt %, or any and all subranges formed by any of these endpoints, based on the total weight of the film composition.

[0066] In an embodiment, the glass transition temperature of the polymer may be greater than or equal to 200° C., 240° C., or 260° C.; and less than or equal to 300° C. or 280° C. Thus, in an embodiment, the glass transition temperature of the polymer may be 200° C. to 300° C., 200° C. to 280° C., 240° C. to 300° C., 240° C. to 280° C., 260° C. to 300° C., 260° C. to 280° C., or any and all subranges formed by any of these endpoints.

[0067] Suitable commercial embodiments of polyamide-imides are available from Solvay under the TORLON brand, e.g., grades 4275 and Al-10; polyimides are available from Huntsman Corporation under the MATRAMID brand, e.g., grade 5318, from Mitsubishi Chemical Advanced Materials under the DURATRON brand, e.g., grade D7000, and from NeXolve Corporation under the NOVACLEAR brand; polyphenylsulfones are available from Solvay under the RADEL brand, e.g., grades R-5000 and R-5900; and polyethersulfones are available from Solvay under the VERADEL brand, e.g., grade A-201NT, and from BASF under the ULTRASON brand, e.g., grade E.

[0068] For example, particularly suitable commercial embodiments of the polymer include MATRAMID 5318 polyimide from Huntsman, TORLON Al-10 polyamide-imide from Solvay, and ULTRASON E polyethersulfone from BASF.

[0069] Solvent

[0070] In an embodiment, the film composition may further include a solvent to dissolve the polymer. Therefore, in an embodiment, when deposited on the back side of the substrate to form the back side film layer 108, the film composition may be used in the form of a solution (such as a liquid solution).

[0071] In an embodiment, the solvent may be selected from at least one of the following: amides, imides, imidazoles, dioxanes, dialkylamino oxopentanoates, valeroacetones, oxopentanoates, dialkylacetamides, and N-alkylpyrrolidones. In an embodiment, the dialkylacetamide may comprise dimethylacetamide (DMAC). In an embodiment, the N-alkylpyrrolidone may comprise N-methylpyrrolidone (NMP). In an embodiment, the dialkylamino oxopentanoate (DAOP) may comprise 5-(dialkylamino)-2-methyl-5-oxopentanoate). Suitable commercial embodiments of the dialkylamino oxopentanoate (DAOP) are available from Solvay under the RHODIASOLV brand, such as POLARCLEAN.

[0072] Particularly suitable embodiments of the solvent include N-alkylpyrrolidones, such as NMP. Advantageously, when NMP is used as a solvent, it helps achieve the desired viscosity of the film composition, which in turn helps achieve good coating of the film composition onto the back side of the substrate using conventional spin coater equipment. As described elsewhere herein, in embodiments, the viscosity of the film composition can be from about 100 cP to about 27000 cP, or from about 100 cP to about 8000 cP when measured at 25°C.

[0073] Conversely, for example, when DMAC is used as a solvent, it can contribute to making the viscosity of the film composition lower than desired. Further, for example, when a DAOP such as POLARCLEAN is used as a solvent, it can contribute to making the viscosity of the film composition higher than desired.

[0074] In an embodiment, the amount of solvent in the film composition may be greater than or equal to 50 wt%, 55 wt%, or 60 wt%, based on the total weight of the film composition; and less than or equal to 99 wt%, 95 wt%, or 90 wt%. Therefore, in an embodiment, based on the total weight of the film composition, the amount of solvent in the film composition may be 50 wt% to 99 wt%, 55 wt% to 95 wt%, 60 wt% to 90 wt%, or any and all subranges formed by any of these endpoints.

[0075] In embodiments, the solvent in the film composition may be removed during processing (eg, by drying) to form the back film layer 108. After drying, any solvent remaining in the back film layer may be referred to as residual solvent.

[0076] For example, in an embodiment, a drying process can be performed, including the following steps: (i) soft baking to achieve slow evaporation of the solvent and promote film formation (e.g., at about 180°C for about 5 minutes); (ii) hard baking at or above the boiling point of the solvent to remove residual solvent in the film (e.g., at about 200°C for about 15 minutes); (iii) curing to achieve a minimum residual solvent amount and a target curing level (e.g., at about 250°C for about 15 minutes).

[0077] In an embodiment, the acceptable minimum residual solvent amount may be less than or equal to about 0.6 wt %, based on the total weight of the back film layer (ie, the film composition after drying).

[0078] Wetting Agents

[0079] In embodiments, the film composition may further comprise a wetting agent for improving the wettability of the film composition for deposition on the back side of the substrate (eg, coating as a liquid solution).

[0080] In an embodiment, the amount of the wetting agent in the film composition may be greater than or equal to 0.1 wt%, 0.15 wt%, or 0.18 wt%, based on the total weight of the film composition; and less than or equal to 1 wt%, 0.5 wt%, or 0.25 wt%. Therefore, in an embodiment, the amount of the solvent in the film composition may be 0.01 wt% to 1 wt%, 0.15 wt% to 0.5 wt%, 0.18 wt% to 0.25 wt%, or any and all sub-ranges formed by any of these endpoints, based on the total weight of the film composition. For example, in an embodiment, the amount of the wetting agent may be 0.2 wt%, based on the total weight of the film composition.

[0081] Suitable wetting agents may include conventional or commercially available wetting agents, which may include dyes having wetting properties, such as anthraquinone dyes.

[0082] For example, a particularly suitable commercial embodiment of a wetting agent includes MACROLEX Green 5B available from Lanxess.

[0083] Non-limiting exemplary embodiments

[0084] In an embodiment, the film composition may include 0.5 wt % to 27 wt % of a polymer selected from polybenzimidazoles, and 73 wt % to 95 wt % of a solvent selected from at least one of dialkylacetamides, N-methylpyrrolidone, and dialkylformaldehydes, based on the total weight of the film composition.

[0085] In an embodiment, the film composition may include 2 wt % to 50 wt % of a polymer comprising a blend of polyimide and other polymers in a weight ratio of 1:1 to 1:10, based on the total weight of the film composition, and the other polymer is selected from at least one of polyamide-imide, polyimide, and polyetherimide.

[0086] In an embodiment, based on the total weight of the film composition, the film composition may include: 2 wt % to 12 wt % of a polymer and 50 wt % to 95 wt % of a solvent, the polymer comprising a blend of polysulfone and other polymers in a weight ratio of 1:3 to 3:1, the other polymer is selected from at least one of polyimide, polyetherimide, and polyamide-imide, and the solvent is selected from at least one of dialkylamino oxopentanoate, valerolactone, oxopentanoate, dialkylacetamide, and N-alkylpyrrolidone.

[0087] In an embodiment, the film composition may comprise, based on the total weight of the film composition, 2 to 30 wt % of a polymer and 70 to 98 wt % of a solvent, the polymer comprising a blend of polysulfone (or a similar polymer) and polyimide (or a similar polymer) in a weight ratio of 3:1 to 1:3, and the solvent is selected from at least one of dialkylamino oxopentanoate, valerolactone, oxopentanoate, dialkylacetamide, and N-alkylpyrrolidone.

[0088] In an embodiment, the film composition may include 5 wt % to 20 wt % of a polymer selected from polysulfone and 80 wt % to 95 wt % of a solvent selected from at least one of dialkylaminooxopentanoate, valerolactone, dialkylacetamide, and N-methylpyrrolidone, based on the total weight of the film composition.

[0089] In an embodiment, the film composition may include 20 wt % to 99.8 wt % of a polymer selected from polyamide-imide and 0.2 to 80 wt % of a polyimide, based on the total weight of the film composition. The film may also contain 0.02 wt % to 0.6 wt % of volatile matter. The volatile matter may include residual solvents, or bound moisture, or volatile organic matter generated during the curing reaction of the polymer.

[0090] In an embodiment, a film composition derived from a 15 to 50 weight / volume percent polymer solution may include a polymer comprising a blend of polyamide-imide and polyimide in a weight ratio of 1:4 to 499:1, based on the total weight of the film composition.

[0091] In an embodiment, the film composition may include 2 wt % to 20 wt % of a polymer selected from at least one of polyimide, polyamide-imide, and polyetherimide, based on the total weight of the film composition.

[0092] Front film

[0093] In embodiments, at least one front side film layer 110 may be deposited on the front side 106 of the substrate 102. For example, in embodiments, the article 100 may be a partially fabricated integrated circuit.

[0094] In an embodiment, the at least one front film layer 110 may include any number of layers and thicknesses. For example, the at least one front film layer 110 may include 32 to 72 layers, and the total thickness may be about 2 μm to about 4 μm. In addition, it should be understood that as advances in the field allow a greater number of layers to be stacked on the substrate 102 as the front film layer 110, the requirements for the back relief process using the back film layer 108 disclosed herein may also increase. In an embodiment, the stress induced in the substrate 102 by the at least one front film layer 110 may be about -500 MPa to about +500 MPa, resulting in a bow that may be between about 200 μm to about 400 μm (for a 300 mm wafer). Those skilled in the art will understand that the number of layers of the at least one front film layer 110 may depend on the application of the 3D-NAND memory device into which the front film layer 110 is incorporated.

[0095] In an embodiment, the at least one front film layer 110 may include silicon oxide, silicon nitride, polysilicon, tungsten, titanium nitride, or a combination thereof. In an embodiment, the at least one front film layer 110 may include alternating oxide layers and nitride layers (e.g., silicon oxide / silicon nitride / silicon oxide / silicon nitride, etc.). In other embodiments, the at least one front film layer 110 may include alternating oxide layers and tungsten layers (e.g., silicon oxide / tungsten / silicon oxide / tungsten, etc.). The at least one front film layer 110 may be deposited by, for example, the following chemical vapor deposition techniques: plasma enhanced chemical vapor deposition (PECVD), low pressure chemical vapor deposition (LPCVD), metal organic chemical vapor deposition (MOCVD), atomic layer deposition (ALD), plasma enhanced atomic layer deposition (PEALD), or by direct metal deposition (DMD).

[0096] Processing methods

[0097] Reference Figure 2 , a method for processing a substrate is shown in 200. View Figure 1 The method includes the following step 202: depositing a film composition on the back side 104 of the substrate 102 to form a back side film layer 108. The film composition may be a film composition according to any embodiment described herein.

[0098] In an embodiment, the deposition of step 202 includes spin coating, such as the spin coating techniques described in US Pat. Nos. 5,238,878; 5,780,105; and 6,436,851; which are incorporated herein by reference in their entirety. For example, conventional equipment can be used, such as spin coating equipment used in conventional processing (such as photolithography processes).

[0099] Figure 2The method 200 optionally includes step 204: drying or curing the film composition. In an embodiment, the drying or curing step may include heating the film composition at a temperature greater than or equal to 90°C, or 120°C, or 150°C, or 180°C; and less than or equal to 250°C, or 200°C, or 170°C, or 140°C; and for a period of greater than or equal to 30 seconds, or 1 minute, or 2 minutes; and less than or equal to 35 minutes, or 20 minutes, or 10 minutes, or 5 minutes, or 180 seconds. For example, in an embodiment, a drying or curing process may be performed, including the following steps: (i) mild baking to achieve slow evaporation of the solvent and promote film formation (e.g., at about 180° C. for about 5 minutes); (ii) strong baking at or above the boiling point of the solvent to remove residual solvent in the film (e.g., baking at about 200° C. for about 15 minutes); and (iii) curing to achieve a minimum residual solvent amount and a target curing level (e.g., at about 250° C. for about 15 minutes). In an embodiment, the drying or curing step may provide sufficient insolubility to the back film layer 108 to prevent the film layer from being removed by the solvent during post-processing.

[0100] Replay Figure 1 , Figure 2 The method 200 optionally further includes step 206: depositing a front film layer 110 on the front side 106 of the substrate 102. The front film layer and its deposition may conform to any embodiment described herein. In an embodiment, step 206 of depositing the front film layer 110 on the front side 106 of the substrate 102 may occur before step 202 of depositing the film composition on the back side 104 of the substrate 102.

[0101] Figure 2 The method 200 optionally further includes step 208: removing the back film layer 108 from the substrate 102. For example, in an embodiment, the back film layer 108 can be removed by a conventional process such as wet chemical etching. Suitable cleaning agents for removing the back film layer 108 from the substrate 102 include N-alkyl pyrrolidones, such as N-methyl pyrrolidone (NMP).

[0102] Unless otherwise indicated, each document cited herein is incorporated herein by reference in its entirety. Citation of any document shall not be construed as an admission that it is prior art with respect to any invention disclosed or claimed herein. If any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall prevail.

[0103] It will be apparent that modifications and changes may be made without departing from the scope of the disclosure as defined in the appended claims.Although some aspects of the present disclosure are identified herein as preferred or particularly advantageous, it is contemplated that the present disclosure is not necessarily limited to these aspects.

Claims

1. Finished products, including: a substrate having a back surface; and A backside film layer is deposited on the backside of the substrate, wherein the backside film layer comprises a polymer.

2. The article of claim 1, wherein the substrate has a front side, and further comprising at least one front side film layer deposited on the front side of the substrate.

3. The article of any of the preceding claims, wherein the substrate is a semiconductor wafer comprising at least one of silicon, silicon carbide, gallium arsenide, gallium nitride, and germanium, and wherein the article is a partially or fully fabricated integrated circuit.

4. The article of any one of the preceding claims, wherein the polymer comprises at least one of polybenzimidazole (PBI), polyetherimide (PEI), polyamide-imide (PAI), polyimide (PI), polysulfone (PSU), polyphenylsulfone (PPSU), polyethersulfone (PES), and polybenzoxazole (PBO).

5. The article of any one of the preceding claims, wherein the polymer comprises at least one of polyamide-imide (PAI), polyimide (PI), polyphenylsulfone (PPSU), and polyethersulfone (PES).

6. The article of any one of the preceding claims, wherein the polymer comprises (i) polyethersulfone (PES); or (ii) a blend of polyamide-imide (PAI) and polyimide (PI); or (iii) a blend of polyamide-imide (PAI) and polyimide (PI) and polyethersulfone (PES).

7. The article of any of the preceding claims, wherein the backside film layer is deposited as a film composition comprising the polymer, optionally a wetting agent, and optionally a solvent comprising at least one of an amide, an imide, an imidazole, a dioxane, a dialkylamino oxopentanoate, a valerolactone, an oxopentanoate, a dialkylacetamide, and an N-alkylpyrrolidone.

8. The article of any of the preceding claims, wherein the backside film layer is deposited as a film composition comprising the polymer, optionally a wetting agent, and a solvent, wherein the solvent comprises an N-alkylpyrrolidone, and the film composition has a viscosity of about 100 cP to about 8000 cP when measured at 25°C.

9. The article of any one of the preceding claims, wherein the backside film layer has a thickness of about 0.5 μm to about 50 μm.

10. The article of any one of the preceding claims, wherein the backside film layer has a tensile modulus of from about 1 GPa to about 2.3 GPa.

11. The article of any one of the preceding claims, wherein the backside film layer comprises a blend of polyamide-imide (PAI) and polyimide (PI) in a weight ratio of about 19:1 to about 4:1, and the blend has a glass transition temperature of about 230°C to about 295°C.

12. A method of processing a substrate, the method comprising: A film composition is deposited on the back side of the substrate, and the film composition is optionally dried and / or cured to form a back side film layer, wherein the film composition comprises a polymer, an optional wetting agent, and an optional solvent.

13. The method of claim 12, wherein the substrate has a front side, and further comprising at least one front side film layer deposited on the front side of the substrate.

14. The method of any one of claims 12 to 13, wherein the substrate is a semiconductor wafer comprising at least one of silicon, silicon carbide, gallium arsenide, gallium nitride, and germanium, and wherein the substrate is processed to provide a partially or fully fabricated integrated circuit.

15. The method of any one of claims 12 to 14, wherein the polymer comprises at least one of polybenzimidazole (PBI), polyetherimide (PEI), polyamide-imide (PAI), polyimide (PI), polysulfone (PSU), polyphenylsulfone (PPSU), polyethersulfone (PES), and polybenzoxazole (PBO).

16. The method of any one of claims 12 to 15, wherein the polymer comprises at least one of polyamide-imide (PAI), polyimide (PI), polyphenylsulfone (PPSU), and polyethersulfone (PES).

17. The method of any one of claims 12 to 16, wherein the polymer comprises (i) polyethersulfone (PES); or (ii) a blend of polyamide-imide (PAI) and polyimide (PI); or (iii) a blend of polyamide-imide (PAI) and polyimide (PI) and polyethersulfone (PES).

18. The method of any one of claims 12 to 17, wherein the solvent comprises at least one of an amide, an imide, an imidazole, a dioxane, a dialkylaminooxopentanoate, a valerolactone, an oxopentanoate, a dialkylacetamide, and an N-alkylpyrrolidone.

19. The method of any one of claims 12 to 18, wherein the solvent comprises an N-alkylpyrrolidone and the film composition has a viscosity of about 100 cP to about 8000 cP when measured at 25°C.

20. The method of any one of claims 12 to 19, wherein the backside film layer has a thickness of about 0.5 μm to about 50 μm.

21. The method of any one of claims 12 to 20, wherein the backside film layer has a tensile modulus of about 1 GPa to about 2.3 GPa.

22. The method of any one of claims 12 to 21, wherein the depositing comprises spin coating.

23. The method according to any one of claims 12 to 22, wherein the method further comprises: drying and / or curing the film composition to form the back film layer.

24. The method of claim 23, wherein the backside film layer comprises less than or equal to about 0.6 weight percent residual solvent, based on the total weight of the backside film layer.

25. The method of any one of claims 12 to 24, wherein the method further comprises: removing the backside film layer from the backside of the substrate, and wherein the removing comprises using a cleaning agent comprising N-methylpyrrolidone (NMP).

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