Method of peeling resin mask

Abstract

To provide a method of peeling a resin mask, the method enabling suppression of damage to a passivation film of a semiconductor wafer and corrosion of an aluminum electrode, and the method being excellent in resin mask peelability.SOLUTION: A method of peeling a resin mask includes a peeling step of peeling a resin mask from a semiconductor wafer having an aluminum electrode, a passivation film and a resin mask, by using a detergent composition, wherein the detergent composition is a detergent containing an alkanolamine (component A) and a solvent (component B) represented by the following formula (I), the content of the component A in the detergent composition is 65 mass% or more and 75 mass% or less, and the content of the component B in the detergent composition is 15 mass% or more and 35 mass% or less. Formula (I): R-O-(EO)n-H.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present disclosure relates to a method for stripping a resin mask. [Background technology]

[0002] In recent years, the manufacturing process of semiconductor chips mounted on personal computers and various electronic devices has become complicated. Depending on the type of semiconductor, it may be necessary to process the back side of the semiconductor wafer after forming the circuit of the semiconductor element on the front side of the semiconductor wafer, such as polishing the back side of the semiconductor wafer. In this case, since the circuit of the semiconductor element has already been formed on the front side of the semiconductor wafer, the top surface of the front side of the semiconductor wafer is composed of a permanent protective film (referred to as a "passivation film" in this disclosure) that protects the circuit and electrodes for electrical connection with other electronic components, but it is necessary to further temporarily protect the front side of the semiconductor wafer in order to prevent the passivation film and electrodes on the front side of the semiconductor wafer from being destroyed or contaminated by the processing of the back side of the semiconductor wafer.

[0003] As a method for temporarily protecting the front surface of a semiconductor wafer, there is a technique for attaching a tape or sheet-like protective material. For example, Patent Document 1 describes a surface protection method that includes protecting the front surface of a semiconductor wafer with a photoresist film when processing the back surface of the semiconductor wafer. It also describes that the workpiece (semiconductor wafer protected with a photoresist film) after processing of the back surface of the semiconductor wafer is immersed in a resist stripping solution, and ultrasonic vibration is applied to strip the photoresist film from the front surface of the semiconductor wafer. Patent Document 2 describes a manufacturing method for a semiconductor device, the method comprising the steps of (a) attaching a protective sheet to a surface of a wafer having a surface and a back surface opposite to the surface, (b) performing a process on the back surface after the step (a), and (c) peeling the protective sheet from the surface after the step (b), in which the step (c) is a specific step. It also describes that there are steps of forming a wiring layer and a passivation film before the step of attaching the protective sheet.

[0004] On the other hand, various resist strippers have been developed. For example, Patent Document 3 describes a resist stripper composition that has sufficient stripping properties even for resist patterns that have been altered by etching or the like, has low corrosiveness to aluminum or copper substrates during water washing or moisture absorption, does not adversely affect the working environment, and can be rinsed with water for rinsing, and is extremely practical, comprising 20-90% by weight of an organic amine, 0.1-20% by weight of a specific phosphate ester surfactant, 0.1-20% by weight of 2-butyne-1,4-diol, and at least one solvent selected from glycol monoalkyl ethers and aprotic polar solvents. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2001-53041 A [Patent Document 2] JP 2019-197755 A [Patent Document 3] Japanese Patent Application Publication No. 4-124668 Summary of the Invention [Problem to be solved by the invention]

[0006] When the semiconductor element forming surface of the semiconductor wafer is protected with a resin mask or resist in order to treat the back side of the semiconductor wafer on which the circuit of the semiconductor element is formed, a heat treatment process is included in the treatment of the back side of the semiconductor wafer. In this case, the heat is also transferred to the resin mask that temporarily protects the front side, so that a resin mask using a heat-resistant resist tends to be used as the resin mask. In order to completely remove the resin mask that is further exposed to heat after curing with a cleaning agent, the cleaning agent composition is required to have high cleaning properties.

[0007] Resin mask residue can cause poor connections between semiconductor chips and other components and damage to electronic components, resulting in defective products and reduced semiconductor chip yields. For this reason, a cleaning composition is required to have high resin mask stripping properties. In addition, aluminum or aluminum alloy is used as an electrode of a wiring layer for a semiconductor element on a semiconductor wafer, and may have a passivation film for protecting the element. If the passivation film on the front side of a semiconductor wafer on which a circuit of a semiconductor element is formed is damaged, it will cause destruction of electronic components, resulting in defective products and a decrease in the yield of semiconductor chips, so a cleaning agent composition is required to have low damage to the passivation film. Furthermore, aluminum is widely used for electrodes, but aluminum is highly corrosive, and the corrosion of aluminum electrodes can also cause poor connections between semiconductor chips and other components and destruction of electronic components, resulting in defective products and a decrease in the yield of semiconductor chips, so a high corrosion prevention ability is required for aluminum.

[0008] Therefore, in one aspect, the present disclosure provides a resin mask stripping method that can suppress damage to a passivation film of a semiconductor wafer and corrosion of an aluminum electrode, and has excellent resin mask stripping properties. [Means for solving the problem]

[0009] In one aspect, the present disclosure relates to a method for stripping a resin mask (hereinafter also referred to as the "stripping method of the present disclosure"), which includes a stripping step of stripping the resin mask from a semiconductor wafer having an aluminum electrode, a passivation film, and a resin mask by using a cleaning composition, the cleaning composition being a cleaning agent (hereinafter also referred to as the "cleaning composition of the present disclosure") containing an alkanolamine (component A) and a solvent (component B) represented by the following formula (I), and the content of component A in the cleaning composition is 65 mass% or more and 75 mass% or less, and the content of component B in the cleaning composition is 15 mass% or more and 35 mass% or less. RO-(EO)nH (I) In the above formula (I), R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, EO represents an ethyleneoxy group, and n is the number of moles of EO added and is 1 or 2. Effect of the Invention

[0010] According to one aspect of the present disclosure, a method for stripping a resin mask can be provided that can suppress damage to a passivation film of a semiconductor wafer and corrosion of an aluminum electrode, and has excellent resin mask stripping properties. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The present disclosure is based on the discovery that by using a cleaning agent composition containing an alkaline agent and a specific solvent, it is possible to efficiently strip a resin mask while suppressing damage to a passivation film of a semiconductor wafer and corrosion of an aluminum electrode.

[0012] According to the present disclosure, it is possible to provide a method for removing a resin mask, which can suppress damage to a passivation film of a semiconductor wafer and corrosion of an aluminum electrode, and has excellent resin mask peeling properties. Furthermore, by using the method for removing a resin mask of the present disclosure, it is possible to obtain high-quality electronic components with a high yield. In the present disclosure, a semiconductor wafer is a circular plate made of crystals of a semiconductor material (e.g., silicon, etc.) that is a manufacturing material for semiconductor chips. In one or more embodiments, a semiconductor element is formed on the front surface of the semiconductor wafer. In a semiconductor wafer on which a semiconductor element is formed, for example, an aluminum electrode is formed on a part of the semiconductor element formed on the front surface of the semiconductor wafer, a passivation film is formed on a part of the front surface of the semiconductor element to protect the semiconductor element, and a resin mask is formed on the entire surface of the semiconductor element forming surface to temporarily protect the semiconductor element forming surface when processing the back surface of the semiconductor element forming surface.

[0013] Although the details of the mechanism of action by which the effects of the present disclosure are expressed are unclear, it is presumed as follows. Alkanolamine (component A) penetrates the resin mask and acts to remove it, but at the same time penetrates the passivation film and causes damage to the passivation film. On the other hand, the solvent represented by formula (I) (component B) has the effect of protecting the surface of the resin mask and passivation film and suppressing the penetration of component A. The effect of the solvent represented by formula (I) (component B) in suppressing the penetration of component A is greater on the passivation film than on the resin mask. Therefore, it is presumed that by selecting the appropriate contents of components A and B, it is possible to remove the resin mask and suppress damage to the passivation film. However, the present disclosure need not be construed as being limited to this mechanism.

[0014] In the present disclosure, a resin mask is a mask for protecting a material surface from treatments such as etching, plating, and heating, i.e., a mask that functions as a protective film temporarily during the process and does not ultimately remain on the semiconductor product. The resin mask may be any resin mask that can protect the entire front surface of the semiconductor wafer, and in one or more embodiments, examples of the resin mask include a resist layer after heating and exposure processes, a resist layer that has been subjected to at least one of heating and exposure treatments (hereinafter also referred to as "heated and / or exposed"), and a hardened resist layer. In one or a plurality of embodiments, the resin material forming the resin mask may be a film-like negative photosensitive resin, a resist film, or a photoresist. Examples of the resin mask include an acrylic acid-based polymer film and a polyimide-based polymer film. Examples of the polyimide-based polymer film used as the resin mask include a solvent-soluble polyimide film, such as an alkali-soluble polyimide film. The thickness of the resin mask is selected depending on the step due to the unevenness of the top surface of the front side of the semiconductor wafer, but it is sufficient if the front side of the semiconductor wafer can be completely protected. The thickness of the resin mask is, for example, 1 μm or more and 100 μm or less, and from the viewpoint of completely protecting the front side of the semiconductor wafer and the hardening time and removal time of the resist used as the resin mask, it is preferably 3 μm or more and 50 μm or less.

[0015] In the present disclosure, in one or more embodiments, a passivation film is a surface protection film that is not removed during a process for protecting a semiconductor element from external damage. The passivation film may be at least one polymer film selected from polyimide (PI)-based polymers, polybenzoxazole (PBO)-based polymers, and silicone-based polymers. The polyimide-based polymer film used as the passivation film may be a solvent-insoluble polyimide film. The thickness of the passivation film is, for example, from 5 μm to 20 μm, and from the viewpoint of suppressing damage when peeling off the resin mask even if the thickness is thin, it is preferably 12 μm or less, and more preferably 10 μm or less.

[0016] In the present disclosure, the aluminum electrode includes electrodes made of aluminum and aluminum alloys, such as alloys of aluminum and silicon, and alloys of aluminum and copper.

[0017] [Peeling process] The stripping method of the present disclosure includes a step of stripping a resin mask from a semiconductor wafer (object to be cleaned) having an aluminum electrode, a passivation film, and a resin mask, by using the cleaning composition of the present disclosure (hereinafter, also simply referred to as a "stripping step"). In one or a plurality of embodiments, the stripping step includes contacting the cleaning composition of the present disclosure with the semiconductor wafer at a temperature of 70° C. or less.

[0018] Examples of the method for peeling off a resin mask from an object to be cleaned using the cleaning composition of the present disclosure, or the method for contacting the object to be cleaned with the cleaning composition of the present disclosure include a method for contacting the object by immersing the object in a cleaning bath containing the cleaning composition, a method for contacting the object by ejecting the cleaning composition in a spray form (shower method), and an ultrasonic cleaning method for irradiating the object with ultrasonic waves during immersion. The cleaning composition of the present disclosure can be used for cleaning as it is without dilution. Examples of the object to be cleaned include the object to be cleaned described below.

[0019] In one or more embodiments, the stripping method of the present disclosure may include a step of contacting the object to be cleaned with the cleaning composition, rinsing with a volatile organic solvent, and drying. In one or more embodiments, the stripping method of the present disclosure may include a step of contacting the object to be cleaned with the cleaning composition, and rinsing with a volatile organic solvent. Examples of the volatile organic solvent include alcohol-based solvents, fluorine-based solvents, ether-based solvents, and ketone-based solvents.

[0020] In the stripping method of the present disclosure, the temperature of the cleaning composition is preferably 20° C. or higher in order to allow the cleaning power of the cleaning composition of the present disclosure to be easily exerted, and from the viewpoint of suppressing damage to the passivation film and reducing the effect on the semiconductor wafer, the temperature is preferably 70° C. or lower, more preferably 65° C. or lower.

[0021] In the stripping method of the present disclosure, the time for which the cleaning composition is brought into contact with the object to be cleaned is preferably 1 minute or more, and more preferably 2 minutes or more, from the viewpoint of stripping the resin mask, and is preferably 20 minutes or less, more preferably 10 minutes or less, and even more preferably 5 minutes or less, from the viewpoint of shortening the process time.

[0022] [Item to be cleaned] In one or more embodiments, the object to be cleaned may be a semiconductor wafer having an aluminum electrode, a passivation film, and a resin mask. In one or more embodiments, the object to be cleaned may be an object having a surface on which a semiconductor element circuit is formed and protected with a resin mask. In one or more embodiments, the object to be cleaned may be an intermediate product of an electronic component having an aluminum electrode, a passivation film, and a resin mask. Examples of the electronic component include at least one component selected from semiconductor chips such as memory chips, logic semiconductor chips, and power semiconductor chips. The intermediate product is an intermediate product in the manufacturing process of an electronic component, and includes an intermediate product after a resin mask treatment. Examples of objects to be cleaned in which the surface on which a semiconductor element circuit is formed is protected with a resin mask include intermediate products for manufacturing electronic components having electrodes (e.g., aluminum electrodes), resist films (resin masks), and passivation films, which are obtained through an electrode formation process in which electrodes (e.g., aluminum electrodes) are formed on a semiconductor wafer (front side of the semiconductor wafer) on which a semiconductor element is formed, a passivation film formation process in which a passivation film is formed on a semiconductor wafer (front side of the semiconductor wafer) on which an electrode is formed, and a resist film formation process in which a resist is applied to the semiconductor wafer (front side of the semiconductor wafer) on which a passivation film is formed, heated and / or exposed to light, and a resist film (resin mask) is formed.

[0023] The resin mask may be, for example, a thermosetting resin mask, a negative resin mask, or a positive resin mask. In the present disclosure, the thermosetting resin mask is a resin that is cured by applying heat to the applied resist to volatilize the solvent in the resist and cause a polymerization and crosslinking reaction. The negative resin mask is formed using a negative resist, and examples of the mask include a negative resist layer that has been exposed to light and / or developed. In the present disclosure, the positive resin mask is formed using a positive resist, and examples of the mask include a positive resist layer that has been exposed to light and / or developed.

[0024] [Cleaning agent composition] In one or more embodiments, the cleaning composition of the present disclosure is a cleaning agent containing the following component A and the following component B.

[0025] <Component A: Alkanolamine> The cleaning composition of the present disclosure contains an alkanolamine (amino alcohol) (hereinafter, also referred to as "component A"). For example, component A may contain a compound represented by the following formula (II). Component A may be one type or a combination of two or more types. In one or more embodiments, component A is a compound that does not have a branched carbon chain. The content of the compound represented by the following formula (II) in component A is preferably 80 mass% or more, more preferably 90 mass% or more, and even more preferably 100 mass%. [ka]

[0026] In the above formula (II), R 1 represents a linear alkanol group having 2 to 4 carbon atoms, and R 2 represents a linear alkanol group having 2 to 4 carbon atoms, a methyl group, or a hydrogen atom; R 3 represents a methyl group or a hydrogen atom. In the above formula (II), R 1 From the viewpoint of improving the peelability of the resin mask, R is preferably a linear alkanol group having 2 or 3 carbon atoms. 2From the same viewpoint, R is preferably a hydrogen atom. 3 From the same viewpoint, represents a hydrogen atom.

[0027] Examples of component A include at least one selected from monoethanolamine, N-methylmonoethanolamine, N-ethylmonoethanolamine, diethanolamine, N-dimethylmonoethanolamine, N-methyldiethanolamine, N-diethylmonoethanolamine, N-ethyldiethanolamine, N-(β-aminoethyl)ethanolamine, and N-(β-aminoethyl)diethanolamine. Among these, monoethanolamine is preferred from the viewpoint of improving the peelability of the resin mask.

[0028] The content of component A in the cleaning composition of the present disclosure is 65% by mass or more, preferably 68% by mass or more, from the viewpoint of improving the peelability of the resin mask, and 75% by mass or less, preferably 72% by mass or less, from the viewpoint of suppressing damage to the passivation film. More specifically, the content of component A in the cleaning composition of the present disclosure is 65% by mass or more and 75% by mass or less, preferably 68% by mass or more and 72% by mass or less. When component A is a combination of two or more kinds, the content of component A refers to the total content thereof.

[0029] In the present disclosure, "the content of each component in the cleaning composition" refers to the content of each component at the time of cleaning (at the time of use), i.e., at the time when the cleaning composition is started to be used for cleaning. In one or more embodiments, the content of each component in the cleaning composition of the present disclosure can be considered as the blending amount of each component in the cleaning composition of the present disclosure.

[0030] <Component B: Solvent> The cleaning composition of the present disclosure contains a solvent represented by the following formula (I) (hereinafter also referred to as "Component B"). Component B may be one type or a combination of two or more types. RO-(EO)nH (I)

[0031] In the above formula (I), R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, EO represents an ethyleneoxy group, and n is the number of moles of EO added and is 1 or 2.

[0032] Examples of component B include ethylene glycol; monoalkyl ethers having an alkyl group with 1 to 4 carbon atoms, such as ethylene glycol monoalkyl ether, diethylene glycol monoalkyl ether, triethylene glycol monoalkyl ether, and tripropylene glycol monoalkyl ether; and the like. Among these, from the viewpoint of improving the peelability of the resin mask, component B is preferably at least one selected from ethylene glycol and diethylene glycol monoalkyl ether having an alkyl group with 1 to 4 carbon atoms. Examples of component B include at least one selected from ethylene glycol and diethylene glycol monobutyl ether (BDG), and from the viewpoint of improving the peelability of the resin mask, BDG is preferred.

[0033] The content of component B in the cleaning composition of the present disclosure is preferably 15% by mass or more, more preferably 20% by mass or more, and even more preferably 25% by mass or more from the viewpoint of suppressing damage to the passivation film, and is preferably 35% by mass or less from the viewpoint of improving the peelability of the resin mask. More specifically, the content of component B in the cleaning composition of the present disclosure is preferably 15% by mass or more and 35% by mass or less, and more preferably 20% by mass or more and 35% by mass or less. When component B is a combination of two or more kinds, the content of component B refers to the total content thereof.

[0034] The mass ratio A / B of the content of component A to the content of component B is preferably more than 1.5 and more preferably 2 or more from the viewpoint of improving the peelability of the resin mask, and is preferably less than 4 and more preferably 3.5 or less from the viewpoint of suppressing damage to the passivation film. More specifically, the mass ratio A / B is preferably more than 1.5 and less than 4, and more preferably 2 or more and 3.5 or less.

[0035] <Component C: Water> The cleaning agent composition of the present disclosure does not contain water or contains 15 mass % or less of water. In one or more embodiments, examples of water (hereinafter also referred to as "component C") include ion-exchanged water, RO water, distilled water, pure water, and ultrapure water. When the cleaning composition of the present disclosure contains component C, the content of component C in the cleaning composition of the present disclosure can be the remainder excluding component A, component B, and any optional components described later. Specifically, from the viewpoint of inhibiting corrosion of an aluminum electrode, the content of component C in the cleaning composition of the present disclosure is preferably 15% by mass or less, more preferably 10% by mass or less, even more preferably 5% by mass or less, even more preferably 3% by mass or less, even more preferably 1% by mass or less, and even more preferably essentially 0% by mass (i.e., not contained).

[0036] <Other ingredients> The cleaning composition of the present disclosure may further contain water (component C) or other components as necessary, in addition to the components A and B. Examples of other components include components that can be used in ordinary cleaning agents, such as alkaline agents other than component A, amines other than component A, organic solvents other than component B, surfactants, chelating agents, thickeners, dispersants, rust inhibitors, polymeric compounds, solubilizers, antioxidants, preservatives, antifoaming agents, and antibacterial agents.

[0037] In one or more embodiments, the cleaning composition of the present disclosure may not contain at least one of a phosphate ester surfactant and 2-butyne-1,4-diol. For example, the content of the phosphate ester surfactant in the cleaning composition of the present disclosure is preferably less than 0.1% by mass, more preferably 0.01% by mass or less, and even more preferably essentially 0% by mass (i.e., not contained). The content of 2-butyne-1,4-diol in the cleaning composition of the present disclosure is preferably less than 0.1% by mass, more preferably 0.01% by mass or less, and even more preferably essentially 0% by mass (i.e., not contained).

[0038] The cleaning composition of the present disclosure does not contain N-methyl-2-pyrrolidone or the content of N-methyl-2-pyrrolidone is 1 mass% or less. When the cleaning composition of the present disclosure contains N-methyl-2-pyrrolidone, the content of N-methyl-2-pyrrolidone in the cleaning composition of the present disclosure is preferably 1 mass% or less, more preferably 0.5 mass% or less, even more preferably 0.01 mass% or less, and even more preferably essentially 0 mass% (i.e., not contained), from the viewpoints of safety and compliance with various regulations.

[0039] [Method of producing the cleaning composition] In one or more embodiments, the cleaning composition of the present disclosure can be produced by blending Component A, Component B, and, as necessary, the above-mentioned optional components (Component C and other components) by a known method. For example, in one or more embodiments, the cleaning composition of the present disclosure can be produced by blending Component A and Component B. Therefore, the present disclosure relates to a method for producing a cleaning composition, which includes a step of blending at least component A and component B. In the present disclosure, "blending" includes mixing component A, component B, and, as necessary, the above-mentioned optional components (component C and other components) simultaneously or in any order. In the method for producing a cleaning composition of the present disclosure, the preferred blending amount of each component may be the same as the preferred content of each component in the cleaning composition of the present disclosure described above.

[0040] [Electronic component manufacturing method] In one aspect, the present disclosure relates to a method for producing an electronic component (hereinafter also referred to as the "method for producing an electronic component of the present disclosure"), which includes a step (peeling step) of peeling a resin mask from a semiconductor wafer (object to be cleaned) having an aluminum electrode, a passivation film, and a resin mask by using the peeling method of the present disclosure. Examples of the object to be cleaned include the above-mentioned objects to be cleaned. According to the manufacturing method of electronic components of the present disclosure, the resin mask used to protect the intermediate product of the electronic component can be effectively peeled off while suppressing damage to the passivation film and corrosion of the aluminum electrode, so that highly reliable electronic components can be manufactured. Furthermore, by carrying out the cleaning method of the present disclosure, the resin mask used to protect the intermediate product of the electronic component can be easily peeled off, so that the cleaning time can be shortened and the manufacturing efficiency of electronic components can be improved.

[0041] In one or more embodiments, the method for producing an intermediate product of an electronic component according to the present disclosure may include the following steps (1) to (5). (1) A step of forming electrodes (e.g., aluminum electrodes) on a semiconductor wafer on which semiconductor elements are formed (a semiconductor element forming surface, the front side surface of the semiconductor wafer) (electrode forming step). (2) A process for forming a passivation film on the semiconductor wafer (the front side of the semiconductor wafer) on which the electrodes have been formed (passivation film formation process) (3) A process of applying a resist onto the semiconductor wafer on which the passivation film has been formed (the front side of the semiconductor wafer), and then heating and / or exposing the resist to light to form a resist film (resin mask) (resist film formation process). (4) The process of performing various processes such as plating, etching, and polishing on the backside of semiconductor wafers (processing process) (5) A step of stripping a resist film (resin mask) using the cleaning composition of the present disclosure (stripping step).

[0042] [kit] In one aspect, the present disclosure relates to a kit for use in either the stripping method of the present disclosure or the method for producing an electronic component of the present disclosure (hereinafter, also referred to as the "kit of the present disclosure"). In one or more embodiments, the kit of the present disclosure is a kit for producing the cleaning composition of the present disclosure. According to the kit of the present disclosure, it is possible to suppress damage to the passivation film of a semiconductor wafer and corrosion of an aluminum electrode, and to obtain a cleaning composition having excellent resin mask stripping properties.

[0043] In one or more embodiments, the kit of the present disclosure includes a kit (two-liquid cleaning composition) that contains a solution (first liquid) containing component A and a solution (second liquid) containing component B in a mutually unmixed state, and the first liquid and the second liquid are mixed at the time of use. Each of the first liquid and the second liquid may contain the above-mentioned optional components (component C, other components) as necessary. EXAMPLES

[0044] The present disclosure will be specifically described below with reference to examples, but the present disclosure is not limited to these examples in any way.

[0045] 1. Preparation of cleaning compositions of Examples 1 to 4, Comparative Examples 1 to 9, and Reference Examples 1 and 2 The components shown in Tables 1 to 3 were blended in the amounts (mass %, active content) shown in Tables 1 to 3 and mixed by stirring to prepare the cleaning compositions of Examples 1 to 4, Comparative Examples 1 to 9, and Reference Examples 1 and 2.

[0046] The cleaning compositions of Examples 1 to 4, Comparative Examples 1 to 8, and Reference Examples 1 and 2 were prepared using the following materials. (Component A) Monoethanolamine [Nippon Shokubai Co., Ltd.] (Component B) Butyl diglycol (BDG) [Diethylene glycol monobutyl ether, manufactured by Nippon Nyukazai Co., Ltd.] Ethylene glycol [FUJIFILM Wako Pure Chemical Co., Ltd.] (Non-ingredient B) Benzyl alcohol [Dow Chemical] Dimethyl sulfoxide [Toray Fine Chemicals Co., Ltd.] (Component C) Water [Pure water of 1μS / cm or less produced using the Organo Corporation pure water system G-10DSTSET]

[0047] 2. Evaluation of the cleaning compositions of Examples 1 to 3 and Comparative Examples 1 to 8 The prepared cleaning compositions of Examples 1 to 3 and Comparative Examples 1 to 8 were evaluated as follows.

[0048] [Preparation of test pieces with aluminum electrodes, passivation film, and resin mask] A semiconductor wafer having a pattern in which the periphery of the aluminum electrodes is protected by a polyimide passivation film was coated with a 3-micron-thick alkali-soluble polyimide over the entire surface of the pattern, and the hardened resin mask was formed.The semiconductor wafer was then cut into individual pieces to produce test pieces (semiconductor wafers having aluminum electrodes, a passivation film, and a resin mask).

[0049] [Evaluation of resin mask peelability] 50 g of each of the cleaning compositions of Examples 1 to 3 and Comparative Examples 1 to 8 was added to a 100 mL glass beaker, and the test pieces were immersed in the beaker for 3 minutes at room temperature (25°C). The test pieces were then rinsed by immersing them twice for 2 minutes in a rinsing tank containing 50 g of ethanol in a 100 mL glass beaker, and then dried by nitrogen blowing. The appearance of the test pieces was observed at 100x magnification using an optical microscope (Microscope, manufactured by Keyence Corporation) to evaluate the presence or absence of peeled resin mask residue. The results are shown in Table 1.

[0050] [Evaluation of damage to passivation film and corrosion of aluminum electrodes] 50 g of each of the cleaning compositions of Examples 1 to 3 and Comparative Examples 1 to 8 was added to a 100 mL glass beaker, and the test pieces were immersed for 60 minutes in a state where the beaker was heated to 65° C. Then, the test pieces were rinsed by immersing the test pieces twice for 2 minutes in a rinsing tank containing 50 g of ethanol in a 100 mL glass beaker, and then dried by nitrogen blowing. The appearance of the test pieces was observed at 100 times using an optical microscope (Microscope, manufactured by Keyence Corporation) to evaluate the presence or absence of cracks in the passivation film and the presence or absence of discoloration of the aluminum electrode.

[0051] [Table 1]

[0052] As shown in Table 1, the cleaning compositions of Examples 1 to 3 were found to suppress damage to the passivation film and to have excellent resin mask peeling properties, compared with Comparative Examples 1 and 2 in which the content of component A was less than 65 mass% and the content of component B was more than 35 mass%, Comparative Example 3 in which the content of component A was less than 65 mass%, Comparative Example 4 which did not contain component B, Comparative Example 5 in which the content of component B was less than 15 mass%, Comparative Example 6 which did not contain component B, and Comparative Examples 7 and 8 which contained non-component B as a solvent. Furthermore, the cleaning compositions of Examples 1 to 3 were excellent in the corrosion inhibition effect on the aluminum electrode.

[0053] 3. Evaluation of the cleaning compositions of Example 4 and Reference Example 1 The cleaning compositions prepared in Example 4 and Reference Example 1 were evaluated as follows. [Evaluation of resin mask peelability] Except for changing the immersion time of the test piece in the cleaning composition to 90 seconds, the resin mask peeling property of the cleaning compositions of Example 4 and Reference Example 1 was evaluated in the same manner as in the evaluation of the resin mask peeling property of the cleaning compositions of Examples 1 and 2. The results are shown in Table 2.

[0054] [Table 2]

[0055] As shown in Table 2, in Example 4, in which butyl diglycol was used as component B, the resin mask could be completely peeled off even with a short immersion time (10 seconds). On the other hand, in Reference Example 1, in which ethylene glycol was used as component B, the resin mask could not be completely peeled off even with a short immersion time (10 seconds). This shows that butyl diglycol has a better resin mask peeling ability than ethylene glycol.

[0056] 4. Evaluation of the cleaning compositions of Example 1 and Reference Example 2 The cleaning composition of Reference Example 2 thus prepared was subjected to the following evaluations. [Evaluation of resin mask peelability] The resin mask peelability of the cleaning composition of Reference Example 2 was evaluated in the same manner as in the evaluation of the resin mask peelability of the cleaning composition of Example 1, except that the immersion temperature of the test piece in the cleaning composition was changed to 100° C. and the immersion time was changed to 3 minutes. The results are shown in Table 3.

[0057] [Table 3]

[0058] As shown in Table 3, in Reference Example 2 where the immersion temperature was 100°C, cracks occurred in the passivation film even though the immersion time was shorter (3 minutes) than in Example 1. From this, it can be said that the immersion temperature in the cleaning composition is preferably 70°C or lower. [Industrial Applicability]

[0059] According to the present disclosure, it is possible to provide a resin mask peeling method that can suppress damage to the passivation film of the semiconductor wafer and corrosion of the aluminum electrode, and has excellent resin mask peeling properties. By using the peeling method of the present disclosure, it is possible to improve the performance and reliability of electronic components, and to improve the productivity of semiconductor devices.

Claims

1. A stripping method including a stripping step of stripping a resin mask from a semiconductor wafer having an aluminum electrode, a passivation film, and a resin mask using a cleaning composition, wherein the cleaning composition is a cleaning agent containing an alkanolamine (Component A) and a solvent (Component B) represented by the following formula (I), the content of Component A in the cleaning composition is 65% by mass or more and 75% by mass or less, and the content of Component B in the cleaning composition is 15% by mass or more and 35% by mass or less. R−O−(EO)n−H (I) In the above formula (I), R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, EO represents an ethyleneoxy group, and n is the number of moles of EO added and is 1 or 2.

2. The stripping method according to Claim 1, wherein Component B is at least one selected from ethylene glycol and diethylene glycol monoalkyl ether having an alkyl group having 1 to 4 carbon atoms.

3. The stripping method according to Claim 1 or 2, wherein the mass ratio A / B of the content of Component A to the content of Component B is more than 1.5 and less than 4.

4. The cleaning composition does not contain at least one of a phosphate ester surfactant and 2-butyne-1,4-diol. The stripping method according to Claim 1 or 2.

5. The stripping step includes bringing the cleaning composition into contact with the semiconductor wafer at a temperature of 70° C. or lower. The stripping method according to Claim 1 or 2.

6. The cleaning composition does not contain water or has a water content of 15% by mass or less. The stripping method according to Claim 1 or 2.

7. A method for manufacturing an electronic component, including a step of stripping a resin mask from a semiconductor wafer having an aluminum electrode, a passivation film, and a resin mask using the stripping method according to Claim 1 or 2.