Method for manufacturing wafer with functional film

Abstract

The present invention provides a practically effective method for manufacturing a chip with a functional film, the peripheral portion of the chip surface of which is exposed in a ring shape. In the method for manufacturing a chip with a functional film, even if a high-viscosity coating material is used as a coating material containing functional film constituent components, the functional film on the peripheral portion of the chip surface is cleanly removed, and the end face of the removed functional film has a good shape, so that a flat functional film can be formed, and there is no dirt caused by coating residue on the inclined portion and back side of the chip. A method for manufacturing a chip with a functional film, wherein the outer peripheral portion of the surface of the chip is exposed in a ring shape, and the manufacturing method comprises: step (A), spin coating a high-viscosity coating material containing components of the functional film on the surface of the chip to form a coating film; step (B-1), after step (A), while rotating the chip, supplying a cleaning liquid to the outer peripheral portion of the surface of the chip on which the coating film is formed, to remove the coating film on the outer peripheral portion of the surface of the chip; step (C), after step (B-1), heating the coating film on the chip to form a fluidity suppressing film that suppresses the fluidity of the coating film; step (D-1), after step (C), while rotating the chip, supplying a cleaning liquid to the outer peripheral portion of the surface of the chip on which the fluidity suppressing film is formed, to remove the fluidity suppressing film on the surface of the chip; and step (E), after step (D-1), heating the fluidity suppressing film on the chip to allow the components of the functional film to function and form a functional film.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a wafer with a functional film whose outer peripheral portion of the surface of the wafer is exposed in a ring shape. Background Art

[0002] In the semiconductor integration technology that has been actively developed in recent years, from the perspective of seeking further integration, the circuit substrate plane is integrated (stacked) in a three-dimensional direction, and integrated into multiple layers while connecting wires through silicon through electrodes. During this integration, the surface of each wafer used for integration on the opposite side (i.e., the back side) to the formed circuit surface is thinned by grinding. Then, integration is performed by stacking the thinned wafers.

[0003] Usually, the wafer before thinning is bonded to a support body for grinding by a grinding device, but this bonding must be easy to peel off after grinding, so the wafer is temporarily bonded to the support body. For such temporary bonding, if a large force is required to remove it, it will damage the thinned wafer, so it is important to easily remove it from the support body. However, on the other hand, it is not preferable that the wafer is detached or shifted due to grinding stress when grinding the back side of the wafer.

[0004] Therefore, the performance sought for temporary bonding is to withstand the stress during grinding and be easy to remove after grinding.

[0005] As such a temporary bonding material, for example, a silicone material is known (see, for example, Patent Document 1).

[0006] When the coating material for temporary bonding is applied to the surface of a wafer, a wafer with a coating film can be obtained. When the wafer with the coating film is heated, the coating film becomes a functional film that exerts an adhesive function and has adhesive properties. As a result, a wafer with a functional film can be obtained.

[0007] Furthermore, it is desirable that the functional film formed on the end (peripheral portion) of the wafer is completely removed from the end of the wafer in the manufacture of semiconductor elements. If the functional film is not removed and remains on the end of the wafer, or the end surface of the functional film after the functional film is removed does not have a good shape, when the wafer with the functional film is used in the process after the functional film is formed, the end of the functional film is rubbed and dust is generated, and the wafer conveying arm is contaminated.

[0008] Therefore, a method for manufacturing a wafer with a functional film in which the outer peripheral portion of the surface of the wafer is exposed in a good ring shape and the end surface of the removed functional film has a good shape is desired.

[0009] As a method for manufacturing a wafer with a coating, in which a coating formed on the surface of the wafer is removed from the outer periphery of the wafer so that the outer periphery of the surface of the wafer is exposed in a ring shape, there is known a method for manufacturing a wafer with a coating in which the coating is a resist film (for example, refer to patent document 2).

[0010] Prior art literature

[0011] Patent Literature

[0012] Patent Document 1: International Publication No. 2017 / 221772

[0013] Patent Document 2: International Publication No. 2015 / 121947 Summary of the invention

[0014] Problems to be solved by the invention

[0015] Patent Document 2, in which the coating film is a resist film, states that after heating (baking and drying), edge rinsing liquid and back rinsing liquid are sprayed to remove the coating film (see claim 1, paragraph

[0016] , etc.). In addition, Patent Document 2 states that after removing the coating film on the outer periphery of the surface of the wafer, the wafer with the coating film is transported to an exposure device and provided for a photolithography process (see paragraph

[0023] ). That is, it is recorded that the coating film removal is completed by the rinsing process, and then the next process is entered.

[0016] As described in Patent Document 2, when the coating film is a resist film, when manufacturing a wafer with a resist film in which the outer periphery of the surface of the wafer is exposed in a ring shape, a rinsing process can be performed after heating. Patent Document 2 records that if the rinsing process is performed after heating (baking and drying), a wafer with a resist film formed by removing the resist film on the outer periphery of the surface of the wafer can be formed.

[0017] On the other hand, the functional film as the object of the present invention is a film that exerts functionality by heating. Therefore, in the present invention, if a wafer with a functional film is to be obtained, a heating process for forming the functional film is required. For example, in the case of a functional film having the above-mentioned temporary bonding material as the object, it is necessary to apply a coating material for temporary bonding on the surface of the wafer to obtain a wafer with a coating film, and then, the coating film is heated to obtain a wafer with a functional film that exerts a bonding function.

[0018] However, when a coating film including a coating material for temporary bonding is heated to solidify the constituent components of the film and form a functional film having bonding properties, it is difficult to dissolve the functional film using a rinse solution because the functional film is being solidified. Therefore, even if a rinse solution is sprayed to remove the functional film after the functional film is formed, the functional film cannot be fully removed.

[0019] Therefore, in order to remove the functional film on the outer periphery of the wafer surface and obtain a wafer with the functional film in which the outer periphery of the wafer surface is exposed in a ring shape, it is necessary to perform a rinsing step before heating to cure the coating film.

[0020] Therefore, the present invention is not a method that does not require heat treatment after the rinsing process as in the case where the coating film is a resist film, but a method for manufacturing a chip unique to a functional film whose steps are different from those of the method for the resist film, and is targeted at a method for manufacturing a chip that includes a heat treatment as a necessary step for obtaining a functional film after the rinsing process.

[0021] In addition, among the coating materials containing components constituting the functional film, there are many high-viscosity coating materials as shown in the above-mentioned temporary bonding materials. Even when such high-viscosity coating materials are used to manufacture a wafer with a functional film, it is also desired to manufacture a wafer with a functional film in which the functional film on the peripheral portion of the surface of the wafer is completely removed and the peripheral portion of the surface of the wafer is exposed in a good ring shape.

[0022] However, the present inventors have found out that when a high-viscosity coating material is used as the coating material, it is difficult to completely remove the functional film on the outer periphery of the surface of the wafer and leave the functional film with a good end face shape.

[0023] Furthermore, it was found that when a coating film is formed on the surface of a wafer by spin coating using a high-viscosity coating material, contamination of the back surface of the wafer due to splashing of the liquid becomes a major problem.

[0024] Therefore, an object of the present invention is to provide a practically effective method for manufacturing a chip with a functional film, in which the peripheral portion of the chip surface is exposed in a ring shape. In the method for manufacturing a chip with a functional film, even if a high-viscosity coating material is used as a coating material containing functional film constituent components, the functional film on the peripheral portion of the chip surface is cleanly removed, and the end face of the removed functional film has a good shape, so that a flat functional film can be formed, and there is no dirt caused by coating residue on the inclined portion and back side of the chip.

[0025] Solutions for solving problems

[0026] In order to solve the above-mentioned problems, the inventors of the present invention have repeatedly conducted in-depth studies on the method for manufacturing a chip with a functional film using a high-viscosity coating material containing components constituting a functional film. As a result, the present invention was completed by discovering the following fact, namely, in addition to heating for forming the functional film, heating for suppressing the fluidity of the coating is also provided, and these two heating steps are required steps, and a cleaning (rinsing) step is performed before and after the initial heating step, respectively. This allows the manufacture of a practically effective chip with a functional film in which the functional film on the outer peripheral portion of the surface of the chip is completely removed and there is no dirt caused by residual coating on the bevel and back side of the chip.

[0027] That is, the present invention includes the following aspects.

[0028] [1] A method for manufacturing a chip with a functional film, wherein the outer peripheral portion of the surface of the chip is exposed in a ring shape, the manufacturing method comprising: step (A), spin coating a high-viscosity coating material containing components of the functional film on the surface of the chip to form a coating film; step (B-1), after the above step (A), supplying a cleaning liquid to the outer peripheral portion of the surface of the chip on which the coating film is formed while rotating the chip to remove the coating film on the outer peripheral portion of the surface of the chip; step (C), after the above step (B-1), heating the coating film on the chip to form a fluidity suppressing film that suppresses the fluidity of the coating film; step (D-1), after the above step (C), supplying a cleaning liquid to the outer peripheral portion of the surface of the chip on which the fluidity suppressing film is formed while rotating the chip to remove the fluidity suppressing film on the surface of the chip; and step (E), after the above step (D-1), heating the fluidity suppressing film on the chip to allow the components of the functional film to function and form a functional film.

[0029] [2] The method for manufacturing a wafer with a functional film according to [1], wherein the viscosity of the high-viscosity coating material is 1000 mPa·s to 15000 mPa·s.

[0030] [3] The method for manufacturing a wafer with a functional film according to [1] or [2], wherein the functional film constituent component includes a polymer.

[0031] [4] The method for producing a wafer with a functional film according to [3], wherein the polymer includes polysiloxane.

[0032] [5] A method for manufacturing a chip with a functional film according to any one of [1] to [4], wherein, in the step (D-1) of removing the above-mentioned fluidity suppressing film on the surface of the above-mentioned chip, the following steps (D-1-1) and (D-1-2) are performed while the above-mentioned chip is rotated: 1) in the step (D-1-1), a cleaning liquid is supplied to the peripheral portion of the surface of the above-mentioned chip on which the above-mentioned fluidity suppressing film is formed, thereby removing the above-mentioned fluidity suppressing film on the surface of the above-mentioned chip; 2) in the step (D-1-2), a supply position is moved from the supply position of the cleaning liquid in the above-mentioned step (D-1-1) to a position outside the center of the above-mentioned chip, and at the supply position after the movement, a cleaning liquid is supplied to the peripheral portion of the surface of the above-mentioned chip on which the above-mentioned fluidity suppressing film is formed, thereby removing the above-mentioned fluidity suppressing film on the surface of the above-mentioned chip.

[0033] [6] A method for manufacturing a chip with a functional film according to any one of [1] to [5], comprising a step (B-2) of supplying a cleaning liquid to the back side of the chip to clean the back side of the chip after the step (A) and before the step (C).

[0034] [7] A method for manufacturing a chip with a functional film according to any one of [1] to [6], comprising a step (D-2) of supplying a cleaning liquid to the back side of the chip to clean the back side of the chip after the step (C) and before the step (E).

[0035] [8] The method for producing a wafer with a functional film according to any one of [1] to [7], wherein the cleaning liquid is a hydrocarbon-based cleaning liquid.

[0036] Effects of the Invention

[0037] According to the present invention, a practically effective method for manufacturing a chip with a functional film in which the peripheral portion of the chip surface is exposed in a ring shape can be provided. In the method for manufacturing a chip with a functional film, even if a high-viscosity coating material is used as a coating material containing functional film constituent components, the functional film on the peripheral portion of the chip surface is cleanly removed, and the end face of the removed functional film has a good shape, so a flat functional film can be formed, and there is no dirt caused by coating residue on the inclined portion and back side of the chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a diagram showing the measurement results of the change in the film thickness of the functional film near the outer periphery of the silicon wafer with the functional film in Example 1 and Comparative Example 1.

[0039] Figure 2 This is a graph showing changes in viscosity of the dry film obtained in Reference Example 1 with respect to temperature. DETAILED DESCRIPTION

[0040] Hereinafter, the method for manufacturing a wafer with a functional film of the present invention will be described in detail. However, the description of the components described below is an example of one embodiment of the present invention and is not limited to these contents.

[0041] (Method for manufacturing wafer with functional film)

[0042] The method for producing a wafer with a functional film of the present invention produces a wafer with a functional film in which the outer peripheral portion of the surface of the wafer is exposed in a ring shape.

[0043] The method for manufacturing a chip with a functional film of the present invention includes: (I) step (A), spin coating a high-viscosity coating material containing components of the functional film on the surface of the chip to form a coating film; (II) step (B-1), after step (A), while rotating the chip, supplying a cleaning liquid to the peripheral portion of the surface of the chip with the coating film formed, thereby removing the coating film on the peripheral portion of the surface of the chip; (III) step (C), after step (B-1), heating the coating film on the chip to form a fluidity suppressing film that suppresses the fluidity of the coating film; (IV) step (D-1), after step (C), while rotating the chip, supplying a cleaning liquid to the peripheral portion of the surface of the chip with the fluidity suppressing film formed, thereby removing the fluidity suppressing film on the surface of the chip; and (V) step (E), after step (D-1), heating the fluidity suppressing film on the chip to allow the components of the functional film to function and form a functional film.

[0044] The method for manufacturing a chip with a functional film of the present invention, which includes all of the above-mentioned steps (I) to (V), can also be shown in the following embodiment to manufacture a practically effective chip with a functional film, wherein the above-mentioned chip with a functional film is a chip with a functional film in which the functional film on the outer peripheral portion of the surface of the chip is cleanly removed, and the outer peripheral portion of the surface of the chip is exposed in a good annular shape, and there is no dirt caused by residual coating on the inclined portion and the back side of the chip.

[0045] All the steps (I) to (V) above interact with each other to achieve the excellent effects of the present invention. For example, no matter which of the steps (B-1) of removing the coating film using a cleaning solution in the above (II) or the step (D-1) of removing the fluidity suppressing film using a cleaning solution in the above (IV) is removed, a wafer with a functional film that can be effectively used in practice as required by the present invention cannot be obtained.

[0046] It should be noted that in the present invention, the peripheral portion of the chip refers to the end of the chip. For example, when the chip is circular, when the center of the circle is set to 0 and the periphery is set to 100, it refers to an annular area of ​​50 to 100, preferably 70 to 100, more preferably 90 to 100, and particularly preferably 95 to 100.

[0047] In addition, as preferred embodiments of the method for manufacturing a chip with a functional film of the present invention, there can be listed: a method for manufacturing a chip with a functional film which also includes (II-1) a step (B-2) of supplying a cleaning liquid to the back side of the chip to clean the back side of the chip after the above-mentioned step (A) and before the above-mentioned step (C); and a method for manufacturing a chip with a functional film which also includes (IV-1) a step (D-2) of supplying a cleaning liquid to the back side of the chip to clean the back side of the chip after the above-mentioned step (C) and before the above-mentioned step (E).

[0048] Hereinafter, each process will be described in detail.

[0049] <(I) Process (A)>

[0050] In step (A), a coating film composed of a high-viscosity coating material is formed on the surface of the wafer.

[0051] The coating film was formed by spin coating.

[0052] The high-viscosity coating material contains functional film-constituting components.

[0053] In the present invention, when applying the coating material on the surface of the wafer, a spin coating method is used from the viewpoint of obtaining a uniform film easily and with good reproducibility.

[0054] The spin coating method is a method of supplying a coating material to the surface of a rotating wafer, spreading the coating material by centrifugal force, and coating the coating material on the entire surface of the wafer.

[0055] <<Whip>>

[0056] The shape of the wafer is not particularly limited, for example, it can be a circle, or a shape other than a circle such as a polygon. In addition, in the case of a circle, it can be a true circle or an ellipse. Usually, a circle is used more.

[0057] The wafer may have a notch portion in which a portion is notched. The notch portion may be, for example, a notch (a groove in a U-shape, a V-shape, etc.) or a straight portion extending in a straight line (a so-called orientation flat).

[0058] The wafer may be various substrates such as a semiconductor substrate, a glass substrate, a mask substrate, or an FPD (Flat Panel Display) substrate.

[0059] When the wafer is circular, the diameter is preferably about 200 mm to 450 mm. When the wafer is a shape other than circular, the size is preferably a size of a circle with a diameter of about 200 mm to 450 mm.

[0060] The thickness of the wafer is preferably about 400 μm to 1200 μm.

[0061] As a typical example of the wafer, a semiconductor substrate can be cited, for example, a silicon wafer having a diameter of about 300 mm and a thickness of about 770 μm can be cited, but the present invention is not limited thereto.

[0062] <<High viscosity coating material>>

[0063] The high-viscosity coating material contains functional film-constituting components.

[0064] The high-viscosity coating material may contain a solvent when necessary, for example, when the material does not have a viscosity sufficient to be applied without the solvent.

[0065] The functional film constituent is a component that functions by heating at a predetermined temperature or above and can form a functional film. More specifically, for example, it refers to a component that can form a functional film having adhesive properties by curing by heating, such as the above-mentioned temporary adhesive constituent.

[0066] Examples of the functional film constituent components include various material components such as a conductive material component, an insulating material component, an adhesive component, and a protective material component.

[0067] The functional film constituent component preferably contains a polymer.

[0068] Specific examples of the functional film constituent components include, for example, adhesive compositions containing adhesive components. Examples of such adhesive components include, but are not limited to, polysiloxane adhesives, acrylic resin adhesives, epoxy resin adhesives, polyamide adhesives, polystyrene adhesives, polyimide adhesives, and phenolic resin adhesives.

[0069] Among them, as the functional film constituent component, a thermosetting resin component containing a polysiloxane resin is preferred.

[0070] The viscosity of the high viscosity coating material used in the present invention refers to a viscosity of 1000 mPa·s or more measured by an E-type viscometer. It should be noted that from the viewpoint of forming a coating film by spin coating, the viscosity of the high viscosity coating material is preferably 15000 mPa·s or less.

[0071] From the viewpoint of appropriately exposing the outer peripheral portion of the surface of the chip in a ring shape and forming a functional film with excellent flatness on the chip with good reproducibility, the viscosity of the high-viscosity coating material used in the present invention is preferably 1000mPa·s to 12000mPa·s, more preferably 1000mPa·s to 10000mPa·s, and further preferably 1500mPa·s to 10000mPa·s.

[0072] The concentration of the functional film constituent components in the high viscosity coating material is preferably about 40% to 100% by mass in the high viscosity coating material. Here, the functional film constituent components refer to components other than the solvent contained in the high viscosity coating material.

[0073] It should be noted that, when the high-viscosity coating material does not contain a solvent, sometimes a certain component of the functional film constituent components plays a role in finally constituting the functional film and plays the same role as the solvent in the high-viscosity coating material. In such a case, by including such a component, i.e., a component showing viscosity adjustment ability, the viscosity of the high-viscosity coating material is within the above-mentioned range although there is no solvent, and a part of the component is evaporated by heating to reduce fluidity, thereby realizing a fluidity-suppressed film, and the remainder remains in the film, thereby finally constituting a functional film.

[0074] <<Solvent>>

[0075] In the case where the high-viscosity coating material contains a solvent, the type of the solvent is not particularly limited and can be appropriately selected according to the purpose, but for example, it is preferably free of an organic solvent having a boiling point higher than the temperature required for curing the functional film constituent components. The reason is that, in the case of containing an organic solvent having a boiling point higher than the temperature required for curing the functional film constituent components, depending on the thickness of the coating film and the amount of the solvent used, it is sometimes impossible to remove the solvent in the coating film by heating to a degree that can fully reduce the fluidity. Considering such a situation, the amount of the organic solvent having a boiling point higher than the temperature required for curing the functional film constituent components is 50% by mass or less in the contained solvent, preferably 30% by mass or less, more preferably 20% by mass or less, and further preferably 10% by mass or less.

[0076] The solvent can be appropriately selected in consideration of the solubility of the functional film constituent components, the relationship between the boiling point and the temperature required for curing of the functional film constituent components, the desired film thickness, and the like.

[0077] The solvents may be used alone or in combination of two or more.

[0078] When the high-viscosity coating material contains a solvent, specific examples of the solvent used include: linear or branched aliphatic hydrocarbons such as hexane, heptane, octane, nonane, decane, undecane, dodecane, isododecane, etc.; cyclic aliphatic saturated hydrocarbons such as cyclohexane, cycloheptane, cyclooctane, isopropylcyclohexane, p-menthane, etc.; cyclic aliphatic hydrocarbons such as cyclic aliphatic unsaturated hydrocarbons such as limonene; aromatic hydrocarbons such as benzene, toluene, o-xylene, m-xylene, p-xylene, mesitylene, 1,2,4-trimethylbenzene, isopropylbenzene, 1,4-diisopropylbenzene, p-isopropyltoluene, etc.; MIBK (methyl isobutyl ketone), ethyl methyl ketone, acetone, diisobutyl ketone, 2-octanone, 2-nonanone, 5-nonanone aliphatic saturated hydrocarbon ketones such as dialkyl ketones such as ketone, cycloalkyl ketones such as cyclohexanone; aliphatic unsaturated hydrocarbon ketones such as alkenyl ketones such as isophorone; dialkyl ethers such as diethyl ether, di(n-propyl) ether, di(n-butyl) ether, di(n-pentyl) ether; ethers such as cyclic alkyl ethers such as tetrahydrofuran and dioxane; sulfides such as dialkyl sulfides such as diethyl sulfide, di(n-propyl) sulfide, di(n-butyl) sulfide; amides such as N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethylisobutyramide, N-methylpyrrolidone, 1,3-dimethyl-2-imidazolidinone; nitriles such as acetonitrile and 3-methoxypropionitrile; polyols such as ethylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, 1,3-butanediol, 2,3-butanediol; propylene glycol monomethyl ether, ... Glycol monoalkyl ethers such as glycol monoethyl ether, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, and dipropylene glycol monomethyl ether; glycol monohydrocarbon ethers such as glycol monoaryl ethers such as diethylene glycol monophenyl ether; linear or branched alkyl monoalcohols such as methanol, ethanol, and propanol; alkyl alcohols such as cyclic alkyl alcohols such as cyclohexanol; monoalcohols other than alkyl alcohols such as diacetone alcohol, benzyl alcohol, 2-phenoxyethanol, 2-benzyloxyethanol, 3-phenoxybenzyl alcohol, and tetrahydrofurfuryl alcohol; glycols such as ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, tripropylene glycol, hexanediol, triethylene glycol, 1,2-butanediol, 2,3-butanediol, 1,3-butanediol, 1,4-butanediol, and 1,5-pentanediol; ethylene glycol monohexyl ether, propylene glycol monobutyl ether, diethylene glycol monoethyl ether, dipropylene glycol monobutyl ethers such as ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, diethylene glycol monoisobutyl ether, dipropylene glycol monomethyl ether, diethylene glycol monopropyl ether (propyl carbitol), diethylene glycol monohexyl ether, 2-ethylhexyl carbitol, dipropylene glycol monopropyl ether, tripropylene glycol monomethyl ether, diethylene glycol monomethyl ether, tripropylene glycol monobutyl ether, etc.; glycol monoethers such as 2-phenoxyethanol and other glycol monoaryl ethers; glycol diethers such as ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol dibutyl ether, dipropylene glycol methyl n-propyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, dipropylene glycol dibutyl ether, triethylene glycol dimethyl ether, triethylene glycol butyl methyl ether, tetraethylene glycol dimethyl ether, etc.Glycol ether acetates such as dipropylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate and other glycol monoalkyl ether acetates; cyclic carbonates such as ethylene carbonate, propylene carbonate, vinylene carbonate; esters such as ethyl acetate, butyl acetate, and amyl acetate, etc.;

[0079] In step (A), a high-viscosity coating material is applied to the surface of the wafer by spin coating to form a coating film.

[0080] The coating film refers to a film obtained by applying a coating material, and is a film to which heat is not intentionally applied.

[0081] The coating film can be obtained by supplying a coating material to the surface of the wafer while rotating it. More specifically, for example, a coating film can be formed on the surface of the wafer by supplying a high-viscosity coating material to the rotating wafer using a material supply nozzle disposed above the wafer.

[0082] The thickness of the coating film can be adjusted by adjusting the solid content concentration and viscosity of the coating material and the rotation speed when the wafer is rotated.

[0083] The rotation speed of the wafer can be a commonly used speed, for example, about 500 rpm to 4000 rpm.

[0084] The supply amount of the coating material is appropriately determined in consideration of the surface area of ​​the wafer so that a coating film can be formed on the entire surface of the wafer.

[0085] <(II) Step (B-1)>

[0086] In the step (B-1), a part of the coating film formed in the step (A) is removed.

[0087] Specifically, while the wafer is rotated, a cleaning liquid (rinsing liquid) is supplied to the outer peripheral portion of the surface of the wafer on which the coating film is formed, thereby removing the coating film from the outer peripheral portion of the surface of the wafer.

[0088] More specifically, for example, by discharging and supplying a cleaning liquid to a rotating wafer using a cleaning liquid supply nozzle provided above the wafer, a coating film formed on the surface of the wafer can be dissolved and removed.

[0089] As a method of discharging and supplying the cleaning liquid, for example, a general method known as edge cleaning (EBR: Edge Bead Removal) can be used. The edge cleaning cleans a coating film on the peripheral edge of the surface of a wafer using a rinse liquid or the like.

[0090] By performing the step (B-1), the product quality of the fluidity suppressing film on the outer peripheral portion of the surface of the wafer can be improved in the step (D-1) described later.

[0091] Furthermore, by performing the step (B-1), generation of contamination due to the coating film residue on the bevel portion and the back surface of the wafer can be effectively prevented.

[0092] The bevel portion of the wafer refers to the inclined surface (side surface) of the wafer.

[0093] <<Cleaning fluid>>

[0094] The cleaning liquid (rinsing liquid) is not particularly limited as long as it does not damage the wafer and can dissolve and remove the coating film well, and can be appropriately selected. It is better to appropriately determine it by considering the type of functional film constituent components contained in the high-viscosity coating material used, their concentration, and the film thickness of the coating film.

[0095] The cleaning liquid may contain components other than the solvent, such as salts, but is usually preferably composed only of a solvent from the viewpoint of avoiding or suppressing unnecessary contamination of the substrate with the functional film, deterioration of the functional film, and the like.

[0096] From the viewpoint of being easily dried and removed by heating, the solvent contained in the cleaning liquid preferably does not contain an organic solvent having a boiling point higher than the temperature required to solidify the functional film constituent components. In addition, a solvent with high volatility and excellent drying properties is preferred.

[0097] Specific examples of the solvent contained in the cleaning liquid include the same specific examples of the solvent as those listed above when the high-viscosity coating material contains a solvent.

[0098] The solvents may be used alone or in combination of two or more.

[0099] The cleaning liquid that can be used is a commercially available cleaning liquid. Specific examples thereof include hydrocarbon-based cleaning liquids (cleaning agents) such as Shellsol MC311 (main component: isoparaffin), MC421 (main component: isoparaffin), MC531 (main component: isoparaffin), MC611 (main component: paraffin), MC721 (main component: normal paraffin), and MC811 (main component: mixture (paraffin / cycloparaffin / aromatic hydrocarbon)) manufactured by TOBU CHEMICAL Co., Ltd., but the present invention is not limited to these.

[0100] Among them, as a more preferred cleaning liquid, a hydrocarbon-based cleaning liquid containing aliphatic hydrocarbons that can remove a wide range of functional film constituent components is preferred.

[0101] The supply position of the cleaning liquid in step (B-1) is not particularly limited as long as the coating film on the outer periphery of the wafer can be removed. For example, in the case of a circular wafer, the supply position can be determined in consideration of the width to be finally exposed, the removal power of the coating film of the cleaning liquid, the wetting and spreading property on the wafer, etc. For example, when the center of the circle is set to 0 and the periphery is set to 100, the cleaning liquid can be supplied from the upper side of the surface of the wafer to an annular area of ​​70 to 100.

[0102] The shape of the cleaning liquid supply nozzle is not particularly limited and can be appropriately selected. However, in order to efficiently dissolve the coating film, the cleaning liquid supply nozzle is preferably an injection type nozzle. When the cleaning liquid is sprayed, the cleaning liquid is preferably discharged onto the wafer in a rod shape.

[0103] It should be noted that the supply position of the cleaning liquid supply nozzle does not necessarily need to be above the chip. For example, when the cleaning liquid is supplied with the surface of the chip facing downward, the cleaning liquid supply nozzle can also be arranged below the surface of the chip to supply the cleaning liquid from below the surface of the chip.

[0104] <(II-1) Step (B-2)>

[0105] The present invention may include a step (B-2) of supplying a cleaning liquid to the back surface of the wafer to clean the back surface of the wafer after the step (A) and before the step (C).

[0106] In the above step (B-1), when the coating film is removed, a step (B-2) of supplying the cleaning liquid not only from the front side of the wafer but also from the back side of the wafer may be performed.

[0107] More specifically, for example, the cleaning liquid can be discharged / supplied to the rotating wafer using a cleaning liquid supply nozzle provided on the back side (lower side) of the wafer.

[0108] As a method of discharging and supplying the cleaning liquid, for example, a general method known as backside cleaning (BSR) in which the backside of a wafer is cleaned using a rinse liquid or the like can be used.

[0109] By performing steps (B-1) and (B-2), even if the high-viscosity coating material goes around the back side of the wafer and the material is attached to the back side of the wafer, the attached material can be removed and the clean back side can be maintained. As a result, even if the back side of the wafer contacts the surface of another object, contamination of the other object caused by the contact can be avoided.

[0110] When the cleaning liquid is supplied to the back side of the wafer, the supply area may be the entire back side of the wafer or a portion of the back side of the wafer. When the cleaning liquid is supplied to a portion of the back side of the wafer, for example, when the wafer is circular, the cleaning liquid may be supplied to the periphery thereof or to the annular area described above.

[0111] By performing step (B-1) and step (B-2), generation of contamination due to coating film residue on the bevel and back surface of the wafer can be more effectively prevented. Therefore, in the present invention, it is more preferable to perform step (B-2) in addition to step (B-1).

[0112] <(III) Step (C)>

[0113] In the step (C), the coating film on the wafer is heated to form a fluidity suppressing film that suppresses fluidity of the coating film.

[0114] In the present invention, in addition to the heating step of step (E) for forming the functional film, step (C) is also required as a heating step for suppressing the fluidity of the coating film. By including the two heating steps of step (C) and step (E), a wafer with a functional film which is practically effective as the purpose of the present invention can be obtained.

[0115] The heating in step (C) is provided to lose the fluidity of the coating film provided before step (C). For example, when a coating film having high fluidity is heated in step (C), a fluidity-reduced film having lost its fluidity can be obtained.

[0116] The fluidity-suppressed film is a film obtained by intentionally applying heat to a coating film, and refers to a film in which the fluidity is reduced or lost as compared with the coating film before heating due to heating of the coating film.

[0117] As a specific example of a fluidity-reducing film that has lost fluidity, for example, a dry film can be cited. When the coating material contains a solvent, a dry film formed by evaporating part or all of the solvent in the coating film (or a solid film formed by evaporating the solvent in the coating film and solidifying it) can be obtained by heating in step (C).

[0118] The viscosity of the fluidity-inhibiting film obtained by process (C) as measured by a rheometer at a temperature of 25°C is generally around 30,000 mPa·s to 1,000,000 mPa·s. However, from the viewpoint of obtaining a chip with a functional film with the outer peripheral portion of the surface of the chip appropriately exposed in a ring shape with good reproducibility, the lower limit value is preferably 40,000 mPa·s, more preferably 50,000 mPa·s, and the upper limit value is 800,000 mPa·s in one embodiment and 500,000 mPa·s in another embodiment.

[0119] When a high-viscosity coating material is applied to a wafer by spin coating, the coating film has high viscosity, so the fluidity of the coating film will not be lost by just spinning and the coating film will remain as it is. In particular, when the high-viscosity coating material contains a solvent, the solvent contained in the coating film is not fully dried by just spinning, and the fluidity of the coating film will not be lost and the coating film will remain as it is. Even if you want to remove the end of such a high-fluidity coating film on the wafer with a cleaning liquid, due to the centrifugal force of the rotation of the wafer, a new coating film will be supplied from the inside just after the coating film at the end is removed, and the coating film cannot be completely removed.

[0120] However, by performing heating in step (C) to form a fluidity suppressing film that has lost its fluidity (for example, a dry film (solid film)), there will be no situation in which a new film is supplied from the inside just after the film at the end is removed due to the centrifugal force of the rotation of the chip. Therefore, if the end is removed using a cleaning liquid, the fluidity suppressing film on the outer peripheral portion of the surface of the chip can be completely removed, leaving a fluidity suppressing film with a good end face shape.

[0121] It should be noted that the fluidity suppression film obtained in step (C) has not yet progressed to solidification of the functional film constituent components, and has not yet achieved the function of the functional film constituent components. Since the functional film constituent components have not fully solidified, they exhibit sufficient solubility in the cleaning solution.

[0122] The heating temperature in step (C) varies depending on the temperature required for curing the functional film constituent components contained in the high-viscosity coating material, the film thickness, etc., and therefore cannot be generally specified, but is generally lower than 150° C., preferably lower than 130° C. In addition, the heating time varies depending on the heating temperature, and therefore cannot be generally specified, but is generally 10 seconds to 10 minutes.

[0123] Heating can be performed using, for example, an oven or a hot plate.

[0124] <(IV) Step (D-1)>

[0125] In the step (D-1), a part of the fluidity suppressing film obtained in the step (C) is removed.

[0126] Specifically, while the wafer is rotated, a cleaning liquid (rinsing liquid) is supplied to the outer peripheral portion of the surface of the wafer on which the fluidity suppressing film is formed, thereby removing the fluidity suppressing film from the outer peripheral portion of the surface of the wafer.

[0127] More specifically, for example, by discharging and supplying the cleaning liquid to the rotating wafer using a cleaning liquid supply nozzle provided above the wafer, the fluidity suppressing film formed on the surface of the wafer can be dissolved and removed.

[0128] As a method for discharging / supplying the cleaning liquid, for example, a common method known as EBR can be used as described in the above-mentioned <(II) Step (B-1)>.

[0129] In process (D-1), the end of the fluidity suppressing film (for example, a dry film (solid film)) that has lost its fluidity in process (C) is removed using a cleaning liquid. Therefore, through process (D-1), the fluidity suppressing film on the peripheral portion of the surface of the chip can be completely removed, leaving a fluidity suppressing film with a good end face shape.

[0130] The cleaning liquid used in step (D-1) may be the same as or different from the cleaning liquid used in step (B-1), but both cleaning liquids are preferably the same from the viewpoint of simplifying the process conditions.

[0131] As a preferred embodiment of the step (D-1) of removing the fluidity suppressing film on the surface of the wafer, there is mentioned an embodiment of performing the following step (D-1-1) of 1) and the following step (D-1-2) of 2).

[0132] That is, it is more preferred that in process (D-1), the following processes (D-1-1) and (D-1-2) are performed while the chip is rotated: 1) in process (D-1-1), a cleaning liquid is supplied to the peripheral portion of the surface of the chip on which a fluidity suppressing film is formed, thereby removing the fluidity suppressing film on the surface of the chip; and 2) in process (D-1-2), a supply position is moved from the supply position of the cleaning liquid in the above-mentioned process (D-1-1) to a position outside the center of the chip, and at the moved supply position, a cleaning liquid is supplied to the peripheral portion of the surface of the chip on which a fluidity suppressing film is formed, thereby removing the fluidity suppressing film on the surface of the chip.

[0133] In step (D-1), from the viewpoint of more cleanly removing the fluidity suppressing film on the outer peripheral portion of the surface of the wafer, it is more preferable to change the supply position of the cleaning liquid and supply the cleaning liquid at different supply positions to remove the fluidity suppressing film.

[0134] In step (D-1-2), the supply position of the cleaning liquid is shifted to the outer side compared to the case of step (D-1-1). The reason for wanting to supply the cleaning liquid to the fluidity suppression membrane again to remove the fluidity suppression membrane is that, for example, in step (D-1-1), when the membrane is wetted due to partial contact between the cleaning liquid and the fluidity suppression membrane and liquid seeps out of the membrane, the seeped membrane portion can be reliably removed.

[0135] Therefore, by performing the steps (D-1-1) and (D-1-2), the fluidity suppressing film on the outer peripheral portion of the surface of the wafer can be more reliably removed, and the fluidity suppressing film having a good end face shape can be left.

[0136] It should be noted that, in the above-mentioned steps (D-1-1) and (D-1-2), changing the supply position of the cleaning liquid and supplying the cleaning liquid at different supply positions is described by taking two different supply positions as an example, but the number of different supply positions is not limited to two, and even if it is three or more, for example, further steps (D-1-3), (D-1-4)... may be set.

[0137] <(IV-1) Step (D-2)>

[0138] The present invention may further include a step (D-2) of supplying a cleaning liquid to the back surface of the wafer to clean the back surface of the wafer after the step (C) and before the step (E).

[0139] In the above step (D-1), when the fluidity suppressing film is removed, a step (D-2) of supplying the cleaning liquid not only from the front side of the wafer but also from the back side of the wafer may be performed.

[0140] More specifically, for example, the cleaning liquid can be discharged / supplied to the rotating wafer using a cleaning liquid supply nozzle provided on the back side (lower side) of the wafer.

[0141] As a method for discharging / supplying the cleaning liquid, for example, a common method known as BSR can be used as described in the above-mentioned <(II-1) Step (B-2)>.

[0142] By performing steps (D-1) and (D-2), when the high-viscosity coating material goes around the back side of the wafer and the material is attached to the back side of the wafer, when the above-mentioned step (B-2) is not performed or when the step (B-2) is performed but the attached material is not completely removed, the material attached to the back side can be removed and the clean back side can be maintained. As a result, even when the back side of the wafer contacts the surface of another object, contamination of the other object caused by the contact can be avoided, and in addition, the undesirable situation caused by the attachment of unnecessary materials to the back side of the wafer with a functional film finally obtained can be avoided.

[0143] When the cleaning liquid is supplied to the back side of the wafer, the supply area may be the entire back side of the wafer or a portion of the back side of the wafer. When the cleaning liquid is supplied to a portion of the back side of the wafer, for example, when the wafer is circular, the cleaning liquid may be supplied to the periphery thereof or to the annular area described above.

[0144] By performing steps (D-1) and (D-2), generation of contamination due to the fluidity suppressing film residue on the bevel and back surface of the wafer can be more effectively prevented. Therefore, in the present invention, it is more preferable to perform step (D-2) in addition to step (D-1).

[0145] <(V) Step (E)>

[0146] In step (E), the fluidity suppressing film on the wafer is heated to exert the functions of the components constituting the functional film, thereby obtaining a functional film.

[0147] For example, the functional film constituent components are cured to form the functional film. More specifically, for example, when the functional film is an adhesive film, constituent components having an adhesive component are cured to exhibit adhesive properties to form the functional film (adhesive film).

[0148] The functional film is a film obtained by purposely applying heat to the fluidity suppressing film, and refers to a film in a state where the functions of the components constituting the functional film are exerted by heating.

[0149] For example, the functional film is a film that does not show sufficient solubility in the cleaning solution because the components constituting the functional film are sufficiently cured by heating.

[0150] The heating temperature in step (E) varies depending on the temperature required for curing the functional film constituent components contained in the high-viscosity coating material, the film thickness, etc., and therefore cannot be generally specified, but is generally 150° C. or higher, preferably 180° C. or higher. In addition, the heating time varies depending on the heating temperature, and therefore cannot be generally specified, but is generally 1 minute to 30 minutes.

[0151] Heating can be performed using, for example, an oven or a hot plate.

[0152] As an example of the functional film of the present invention, a functional film having a thickness of 10 μm or more after heating in step (E) is targeted, and as a film formed on the surface of a semiconductor wafer, a relatively thick film is targeted.

[0153] The thickness of the functional film is preferably 20 μm or more, more preferably 30 μm or more, and further preferably 40 μm. On the other hand, considering practical convenience, the thickness of the functional film is 500 μm or less, preferably 300 μm or less, more preferably 200 μm or less, further preferably 100 μm or less, and particularly preferably 70 μm or less.

[0154] By going through process (E), a practically effective chip with a functional film can be obtained, wherein the functional film on the peripheral portion of the surface of the chip is completely removed, the peripheral portion of the surface of the chip is exposed in a good annular shape, and the end face of the removed functional film has a good shape, and there is no dirt caused by residual coating on the inclined portion and the back side of the chip.

[0155] According to the present invention, for example, in the case where the wafer is circular, a wafer with a functional film can be manufactured in which the outer peripheral portion of the surface of the wafer is exposed in a ring shape (doughnut shape). It should be noted that the exposed area formed at this time can be generally set to a ring area of ​​50 to 100 when the center of the circle is set to 0 and the outer periphery is set to 100, and can be set to a ring area of ​​70 to 100 in one embodiment, a ring area of ​​90 to 100 in another embodiment, and a ring area of ​​95 to 100 in another embodiment.

[0156] The viscosity of the functional film obtained by the step (E) measured by a rheometer under the heating temperature conditions of the step is usually more than 1,000,000 mPa·s. From the viewpoint of suppressing deformation of the functional film, displacement of the wafer and the substrate when the wafer with the functional film obtained by the manufacturing method of the present invention is laminated to a substrate in a manner sandwiching the functional film, etc., the viscosity is preferably 2,000,000 mPa·s or more, more preferably 4,000,000 mPa·s or more, further preferably 6,000,000 mPa·s or more, and further preferably 800,000 mPa·s or more. 0000mPa·s or more, and further, the chip and the supporting substrate are bonded together in a manner of sandwiching the functional film to form a stacked body. For example, from the viewpoint of not causing the chip to shift when the stacked body is rotated and the chip is ground for thinning, the pressure is preferably 10000000mPa·s or more, more preferably 20000000mPa·s or more, further preferably 40000000mPa·s or more, further preferably 80000000mPa·s or more, and further preferably 100000000mPa·s or more.

[0157] It should be noted that the viscosity measured by a rheometer under the heating temperature conditions of step (E) of the functional film can be obtained, for example, by the following method: an appropriate amount of dry film is put into a metal cup with a diameter of 65 mm, a metal plate with a diameter of 25 mm is placed on the top to prepare a measurement sample, and the measurement sample is placed in a Twin Drive Rheometer MCR302 manufactured by Anton Paar, and the temperature is raised at 5°C per minute.

[0158] Furthermore, when the functional film of the present invention is, for example, an adhesive film for temporary bonding, the functional film is used to bond the device wafer having the circuit formed thereon to the supporting wafer (supporting substrate) as a supporting body in order to thin the wafer as described above. The device wafer and the supporting wafer, and other films as needed, are bonded together using the functional film, the supporting wafer side is supported, and the device wafer is polished.

[0159] As an example of the case where the wafer with the functional film of the present invention is used in this scheme, a wafer with the fluidity suppressing film obtained through the above step (D-1) and / or the above step (D-1) and the above step (D-2) is used, and the wafer with the fluidity suppressing film is arranged opposite to a supporting wafer as a supporting body in a manner of sandwiching the fluidity suppressing film, and heating in step (E) is performed in this state to form a functional film, and the device wafer and the supporting wafer are bonded. At this time, if necessary, pressure is applied in the vertical direction of the wafer.

[0160] The functional film on the outer periphery of the surface of the device wafer bonded to the supporting wafer is cleanly removed, and the outer periphery of the surface of the wafer is exposed as a wafer with the functional film in a good ring shape. Therefore, in subsequent operation steps such as grinding of the device wafer, there is no need to worry about problems such as dust caused by friction at the end of the functional film or contamination of the wafer conveying arm, and good operation can be carried out.

[0161] Thus, according to the method for manufacturing a chip with a functional film of the present invention, in a post-process using a chip with a circuit substrate after an electronic circuit is formed on the surface of a semiconductor chip, operations can be performed without causing the film formed on the chip with the circuit substrate to be not completely removed from the outer periphery of the chip.

[0162] [Example]

[0163] The present invention will be described in further detail below with reference to examples, but the scope of the present invention is not limited to these examples.

[0164] It should be noted that the devices used in the examples are as follows.

[0165] (1) Coating device: Litho Spin Cup 200C manufactured by Litho Tech Japan.

[0166] (2) Film thickness measurement: Filmetrics Co., Ltd. optical interferometer film thickness meter F50.

[0167] (3) Observation of membrane changes (membrane shape): Probing system DektakXT-A manufactured by BRUKER.

[0168] (4) Film viscosity (dry film viscosity) measurement: Twin Drive Rheometer MCR302 manufactured by Anton Paar.

[0169] (5) Measurement of viscosity of coating material (coating composition): E-type viscometer TVE-22H and TVE-35H manufactured by Toki Sangyo Co., Ltd.

[0170] (Example 1)

[0171] A coating composition was prepared which contained a thermosetting resin component including a polysiloxane resin, and a solvent of p-menthane and n-decane, and had a viscosity of 2500 mPa·s as measured by an E-type viscometer.

[0172] The coating composition was spin-coated (800 rpm, 30 seconds) on the surface of an 8-inch silicon wafer to form a coating film.

[0173] While rotating the silicon wafer with the coating (800 rpm, 10 seconds), a hydrocarbon cleaning liquid (Shellsol MC421 manufactured by TOBU CHEMICAL Co., Ltd., the same below) was continuously discharged and supplied in a rod shape from an injection-type nozzle to the outer periphery of the surface and the outer periphery of the back side of the wafer to remove the coating on the outer periphery of the surface of the wafer and clean the outer periphery of the back side.

[0174] Thereafter, the silicon wafer with the coating film was rotated (800 rpm, 30 seconds) to be spin-dried, and then heated at 120° C. for 90 seconds to obtain a silicon wafer with a fluidity suppressing film (also referred to as a silicon wafer with a dried film).

[0175] While rotating the silicon wafer with the dry film (800 rpm, 60 seconds), the hydrocarbon cleaning liquid is continuously discharged and supplied in a rod shape from the injection nozzle to the outer periphery of the wafer surface and the outer periphery of the back side, thereby removing the dry film on the outer periphery of the wafer surface and cleaning the outer periphery of the back side. Next, while continuing to rotate the silicon wafer, the discharge of the cleaning liquid is temporarily stopped, and the discharge position of the cleaning liquid discharge nozzle that discharges the cleaning liquid to the wafer surface is moved outward by 1.5 mm. Then, the cleaning is restarted, and while rotating the silicon wafer with the dry film (800 rpm, 60 seconds), the hydrocarbon cleaning liquid is continuously discharged and supplied in a rod shape from the injection nozzle to the outer periphery of the wafer surface and the outer periphery of the back side, thereby removing the dry film on the outer periphery of the wafer surface and cleaning the outer periphery of the back side.

[0176] Thereafter, the silicon wafer with the dried film was rotated (1500 rpm, 30 seconds) to be spin-dried, and then heated at 200° C. for 10 minutes to obtain a silicon wafer with a functional film.

[0177] (Comparative Example 1)

[0178] The steps from preparation of the coating composition to heating at 120° C. for 90 seconds in Example 1 were repeated to obtain a silicon wafer with a dried film. The silicon wafer with a dried film was then heated at 200° C. for 10 minutes to obtain a silicon wafer with a functional film.

[0179] (Film Thickness Evaluation of Silicon Wafers with Functional Films)

[0180] The film thickness of the functional film at 17 locations on the silicon wafer with the functional film obtained in Example 1 and Comparative Example 1 was measured. The difference between the average film thickness, the maximum film thickness and the minimum film thickness is shown in Table 1. From the results, it can be confirmed that the two functional films obtained in Example 1 and Comparative Example 1 have the same film thickness.

[0181] The silicon wafer with a functional film of Example 1 was able to form a flat functional film as shown in Table 1 below.

[0182] [Table 1]

[0183]

[0184] (Evaluation of the Functional Film Shape on the Peripheral Part of the Silicon Wafer with Functional Film and the Wafer Backside)

[0185] The change in film thickness of the functional film from the vicinity of the periphery toward the center of each silicon wafer with a functional film obtained in Example 1 and Comparative Example 1 was observed. The results are shown in FIG. Figure 1 .

[0186] like Figure 1 As shown, in Example 1, the change in the thickness of the functional film is almost not observed until the region where the distance from the measurement start point in the end face of the wafer is about 2 mm, and then a sharp change in the film thickness of about 40 μm is confirmed. This means that the functional film is not formed until the region where the distance from the measurement start point is about 2 mm, that is, the silicon wafer is exposed. And it means that the functional film with the expected film thickness (about 40 μm) is formed from the region near 2 mm to the center.

[0187] On the other hand, in Comparative Example 1, a film thickness change equivalent to the expected film thickness (approximately 40 μm) as observed in Example 1 was not confirmed until a film thickness reduction of approximately 25 μm was confirmed in an area near the measurement starting point on the end face of the chip at a distance of 2 mm, after which no substantial change in film thickness was confirmed.

[0188] This means that, considering that the thicknesses of the functional films of Example 1 and Comparative Example 1 are the same, the thickness of the functional film on the periphery of the wafer of Comparative Example 1 is thicker than the expected thickness (about 40 μm).

[0189] In the silicon wafer with a functional film of Example 1, the end surface of the removed functional film has a good shape, and the functional film is completely removed from the outer peripheral portion of the surface of the wafer.

[0190] Furthermore, the back surface of the silicon wafer with a functional film of Example 1 was visually observed, and contamination such as adhesion of the material was not confirmed.

[0191] The silicon wafer with a functional film of Example 1 was a good silicon wafer with a functional film having no dirt on the back surface.

[0192] (Reference Example 1)

[0193] The dry film was peeled off from the silicon wafer with dry film obtained in Example 1, and put into a metal cup with a diameter of 65 mm, and a metal plate with a diameter of 25 mm was placed on the top to prepare a measurement sample. The measurement sample was placed in a Twin Drive Rheometer MCR302 manufactured by Anton Paar, and the viscosity of the dry film was measured under the condition of a temperature increase rate of 5°C per minute.

[0194] The change in viscosity of the dry film with respect to temperature is shown in Figure 2 .like Figure 2 As shown in FIG. 1 , it was confirmed that the viscosity of the dry film increased sharply at 120° C. or higher.

[0195] It should be noted that when the dry film is heated as in this measurement, it is assumed that the viscosity decreases due to the phenomenon (A) that the polymer constituting the dry film softens due to heating, and the viscosity increases due to the phenomenon (B) that the polymer as the main component of the dry film cross-links due to heating. On the other hand, when the coating film is heated at a temperature lower than the temperature at which the above cross-linking occurs, it is assumed that the viscosity decreases due to the above phenomenon (A), and the viscosity increases due to the phenomenon (C) that the solvent evaporates due to heating. In this way, Figure 2 In the measurement results of the viscosity of the dry film shown, in the region below 120°C, the decrease caused by the above phenomenon (A) is dominant, so the viscosity at 120°C is lower than the viscosity at a temperature below 120°C. When the actual coating film is heated, the viscosity increase caused by the above phenomenon (C) is dominant, so the viscosity at 120°C is higher than the viscosity at a temperature below 120°C.

[0196] Furthermore, in the case where the functional film of the present invention is, for example, an adhesive film for temporary bonding, as described above, in order to thin the wafer, the functional film is used to bond the device wafer formed with the circuit to the supporting wafer as a supporting body. The device wafer and the supporting wafer are bonded together using the functional film, the supporting wafer side is supported, and the device wafer is polished. At this time, if the viscosity of the functional film is low, the wafer will shift when the device wafer is polished, and the function cannot be realized. Therefore, in order to realize the function, heating at 150°C or above is usually required. On the other hand, if the viscosity of the functional film becomes high, cross-linking proceeds, and it becomes impossible to dissolve and remove the film using a cleaning solution.

[0197] It can be seen that the functional film of the present invention shows Figure 2In order to manufacture a chip with a functional film whose outer peripheral portion of the chip surface is exposed in a ring shape, a first heating step (equivalent to the above-mentioned step (C)) for producing a dry film soluble in a cleaning solution and a second heating step (equivalent to the above-mentioned step (E)) for producing the functional film are required.

[0198] Next, by comparing the following reference example 2 with the following comparative reference example 1, it is shown that by performing process (B-1) and process (B-2) between process (A) and process (C), a high-quality chip with a functional film without dirt on the bevel and back of the chip can be obtained.

[0199] (Reference Example 2)

[0200] A coating composition was prepared which contained a thermosetting resin component including a polysiloxane resin, and a solvent of p-menthane and n-decane, and had a viscosity of 2500 mPa·s as measured by an E-type viscometer.

[0201] This coating composition was spin-coated (1050 rpm, 20 seconds) on the surface of a 12-inch silicon wafer to form a coating film.

[0202] While rotating the coated silicon wafer (700 rpm, 60 seconds), n-decane is continuously discharged and supplied in a rod shape from an injection-type nozzle toward the periphery of the wafer surface and the periphery of the back side, thereby removing the coating on the periphery of the wafer surface and cleaning the periphery of the back side.

[0203] Thereafter, the silicon wafer with the coating film was rotated (700 rpm, 60 seconds) to be spin-dried, and then heated at 120° C. for 90 seconds to obtain a silicon wafer with a dried film.

[0204] The silicon wafer with the dried film was heated at 200° C. for 10 minutes to obtain a silicon wafer with a functional film.

[0205] (Comparative Reference Example 1)

[0206] The operations from preparation of the coating composition of Reference Example 2 to formation of a coating film by spin coating (1050 rpm, 20 seconds) were repeated to obtain a silicon wafer with a coating film.

[0207] Then, the silicon wafer with the coating film was spin-dried and then heated at 120° C. for 90 seconds to obtain a silicon wafer with a dried film.

[0208] The silicon wafer with the dried film was heated at 200° C. for 10 minutes to obtain a silicon wafer with a functional film.

[0209] (Evaluation of the Wafer Bevel (Side) and Backside of Silicon Wafer with Functional Film)

[0210] Visual observation was made on the wafer periphery (including the side surface) and back surface of each silicon wafer with a functional film obtained in Reference Example 2 and Comparative Reference Example 1. It was confirmed that white precipitates were generated from the wafer periphery to the side surface of the wafer in the silicon wafer with a functional film of Comparative Reference Example 1. This white precipitate may contaminate the conveying arm and the heating plate of the device in the process of making a dry film, so it is not desirable.

[0211] On the other hand, in the silicon wafer with a functional film of Reference Example 2, no white precipitate was observed on the side surface and the back surface of the wafer.

[0212] It can be seen from this that in order to manufacture a practical and effective chip with a functional film that is free of dirt caused by coating residue on the periphery and back of the chip and can prevent contamination of the device, it is necessary to perform a step (B-1) of cleaning the periphery of the chip surface between the step (A) of spin coating to form the coating and the step (C) of heating to produce a dry film, and it is preferred to perform a step (B-2) of cleaning the back of the chip together with this step.

[0213] (Reference Example 3)

[0214] A coating composition was prepared which contained a thermosetting resin component including a polysiloxane resin, and a solvent of p-menthane and n-decane, and had a viscosity of 3000 mPa·s as measured by an E-type viscometer.

[0215] This coating composition was spin-coated (1050 rpm, 20 seconds) on the surface of a 12-inch silicon wafer to form a coating film.

[0216] While rotating the silicon wafer with the coating (700 rpm, 60 seconds), n-decane was continuously discharged and supplied to the periphery of the wafer surface and the periphery of the back side to remove the coating on the periphery of the wafer surface and clean the periphery of the back side.

[0217] Thereafter, the silicon wafer with the coating film was rotated (700 rpm, 60 seconds) to be spin-dried, and then heated at 120° C. for 90 seconds to obtain a silicon wafer with a dried film.

[0218] The dry film was peeled off from the obtained silicon wafer with the dry film, and the dry film was put into a metal cup with a diameter of 65 mm, and a metal plate with a diameter of 25 mm was placed on the top to prepare a measurement sample. The measurement sample was placed in a Twin Drive Rheometer MCR302 manufactured by Anton Paar, and the viscosity of the dry film was measured at 25°C.

[0219] (Reference Example 4)

[0220] A coating composition was prepared which contained a thermosetting resin component including a polysiloxane resin, and a solvent of p-menthane and n-decane, and had a viscosity of 3000 mPa·s as measured by an E-type viscometer.

[0221] The coating composition was placed in a metal cup with a diameter of 65 mm, and a metal plate with a diameter of 25 mm was placed on top to prepare a measurement sample. The measurement sample was placed in a Twin Drive Rheometer MCR302 manufactured by Anton Paar, and the viscosity of the coating composition was measured at 25°C.

[0222] (Evaluation of viscosity of dried film and coating composition)

[0223] The viscosities of Reference Examples 3 and 4 measured by a rheometer at 25° C. are shown in Table 2 below.

[0224] From these results, it can be seen that the viscosity is greatly increased by performing the first heating step for preparing the dry film, and the fluidity of the coating film can be suppressed. In this way, by suppressing the fluidity of the coating film, a new film is not supplied from the inside just after the film at the end is removed due to the centrifugal force of the wafer rotation. Therefore, if the end is removed by a cleaning liquid, the fluidity suppressing film at the peripheral portion of the surface of the wafer can be completely removed, and the fluidity suppressing film with a good end face shape can be left.

[0225] It should be noted that, if the influence of spin coating on drying is considered, the fluidity of the film is different from the fluidity of the coating composition. However, if in the silicon wafer with functional film of Comparative Example 1, the peripheral portion of the wafer is not removed cleanly, and the result of Reference Example 2 and Comparative Reference Example 1 is also considered, it can be considered that the fluidity of the film is as high as the side and back side of the wafer, on the other hand, from the aspect that the peripheral portion of the wafer is removed cleanly in the silicon wafer with functional film of Example 1, it can be considered that the fluidity of the dry film is fully suppressed, and in addition, it is assumed that the viscosity change when the film is obtained by the coating composition is compared, and the viscosity increase when the dry film is made by heating is more significant. Therefore, based on this experiment, it can be confirmed that the fluidity of the film can be fully suppressed by the first heating process.

[0226] [Table 2]

[0227]

[0228] It can be seen from the above embodiments that the method for manufacturing a chip with a functional film of the present invention can manufacture a practically effective chip with a functional film, wherein the chip with a functional film is a chip with a functional film in which the functional film on the outer periphery of the surface of the chip is cleanly removed, and the outer periphery of the surface of the chip is exposed in a good annular shape, and there is no dirt caused by coating residue on the inclined portion and the back side of the chip.

Claims

1. A method for manufacturing a wafer with a functional film, wherein the outer peripheral portion of the surface of the wafer is exposed in a ring shape, the manufacturing method comprising: Step A, spin coating a high-viscosity coating material containing components constituting a functional film on the surface of a wafer to form a coating film; Step B-1, after the step A, supplying a cleaning liquid to the peripheral portion of the surface of the wafer on which the coating film is formed while rotating the wafer, thereby removing the coating film from the peripheral portion of the surface of the wafer; Step C, after the step B-1, heating the coating film on the wafer to form a fluidity suppressing film that suppresses fluidity of the coating film; Step D-1, after the step C, supplying a cleaning liquid to the outer peripheral portion of the surface of the wafer on which the fluidity suppressing film is formed while rotating the wafer, thereby removing the fluidity suppressing film on the surface of the wafer; as well as Step E, after the step D-1, heating the fluidity suppressing film on the wafer to allow the functional film constituent components to function, thereby forming a functional film, The functional film constituent component includes a polymer, and the polymer includes polysiloxane. The heating conditions in the step C and the step E are different, including the heating temperature and the heating time. The heating in step E is set to a heating condition such that the curing of the components constituting the film is accelerated compared to the heating in step C. The heating conditions of the heating in the step C and the heating in the step E are set so that the solubility of the functional film formed in the step E in the cleaning solution is lower than the solubility of the fluidity suppressing film formed in the step C in the cleaning solution. In the step E, the polysiloxane is cured by heating to form an adhesive film having an adhesive function. The step of supplying the cleaning liquid is performed before the heating in the step E, and is not performed after the adhesive film is formed.

2. The method for manufacturing a wafer with a functional film according to claim 1, wherein: The viscosity of the high-viscosity coating material is 1000 mPa·s to 15000 mPa·s.

3. The method for manufacturing a wafer with a functional film according to claim 1 or 2, wherein: In step D-1 of removing the fluidity suppressing film on the surface of the wafer, the following steps D-1-1 and D-1-2 are performed while rotating the wafer. 1) Step D-1-1, supplying a cleaning liquid to the outer peripheral portion of the surface of the wafer on which the fluidity suppressing film is formed, thereby removing the fluidity suppressing film on the surface of the wafer, 2) In step D-1-2, the supply position is moved from the supply position of the cleaning liquid in step D-1-1 to a position outside the center of the chip, and at the moved supply position, the cleaning liquid is supplied to the peripheral portion of the surface of the chip on which the fluidity suppressing film is formed, thereby removing the fluidity suppressing film on the surface of the chip.

4. The method for manufacturing a wafer with a functional film according to claim 1 or 2, wherein: The method includes a step B-2 of supplying a cleaning liquid to the back surface of the wafer to clean the back surface of the wafer after the step A and before the step C.

5. The method for manufacturing a wafer with a functional film according to claim 1 or 2, wherein: The method includes a step D-2 of supplying a cleaning liquid to the back surface of the wafer to clean the back surface of the wafer after the step C and before the step E.

6. The method for manufacturing a wafer with a functional film according to claim 1 or 2, wherein: The cleaning fluid is a hydrocarbon-based cleaning fluid.

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