Method for manufacturing semiconductor substrate

Abstract

To provide a method for manufacturing a semiconductor substrate capable of suppressing generation of a stain on a substrate surface after drying in one embodiment.SOLUTION: In one aspect, the present disclosure relates to a method for producing a semiconductor substrate, the method including the following step 1, step 2, and step 3, the method further including, before the step 1, a step of peeling the semiconductor substrate to which the temporary fixing agent is bonded to remove the temporary fixing agent. Step 1: a step of cleaning the semiconductor substrate to which the temporary fixing agent residue is attached after the peeling treatment with a cleaning agent Step 2: a step of rinsing the semiconductor substrate after Step 1 with a solvent having affinity for both a hydrophobic solvent and water Step 3: a step of drying the semiconductor substrate after Step 2 using a spin processor SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to a method for manufacturing a semiconductor substrate. [Background technology]

[0002] In recent years, the high integration of semiconductor devices has progressed dramatically, and three-dimensional integrated circuit (3DIC) technology has attracted attention. 3DIC technology is a technology for stacking substrates in multiple layers while connecting them using through-silicon vias (TSVs) and other methods. When stacking substrates in multiple layers, it is necessary to thin the backside of the substrate on which the circuit is formed (the side on which the circuit is not formed) by polishing, and then form electrodes on the backside. Before being thinned, a substrate is temporarily fixed (temporarily bonded) to a fixing member (support) with a temporary fixing agent (adhesive), and after undergoing processing such as polishing and electrode formation, the substrate is separated from the fixing member. The temporary fixing agent (adhesive) often remains on the substrate after it has been separated from the fixing member, which can cause problems in subsequent processes. Therefore, a cleaning process is performed to remove the temporary fixing agent (adhesive) remaining on the substrate, and various cleaning compositions for use in the cleaning process have been developed.

[0003] For example, Patent Document 1 proposes a sheet peeling method in which an adhesive sheet is peeled off from an adherend by relative movement between an adherend having an adhesive sheet attached to its surface and a peeling tape attached to the adhesive sheet. Furthermore, Patent Document 2 proposes a cleaning composition for adhesives for removing adhesives remaining on wafers, which contains a glycol ether, a hydrocarbon, and an alkanolamine with a straight-chain alkanol group, and which is water-free or contains 10 mass% or less of water, and has a mass ratio of the glycol ether content to the hydrocarbon content (glycol ether / hydrocarbon) of 1.7 or less. Patent Document 3 proposes a substrate processing method including a wet processing step of supplying a processing liquid to a substrate to perform a predetermined wet processing; a rinse liquid generating step of generating a rinse liquid; and a rinsing step of, after the wet processing step, feeding the rinse liquid into a nozzle along a supply path having one end connected to a nozzle, supplying the rinse liquid from the nozzle to the substrate, and rinsing the substrate with the rinse liquid, wherein the rinse liquid generating step is a step of generating the rinse liquid having a pH of 5 or less by mixing dilute hydrochloric acid or dilute hydrofluoric acid with pure water fed from the other end of the supply path. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-28063 [Patent Document 2] Japanese Patent Application Publication No. 2023-184484 [Patent Document 3] Japanese Patent Application Laid-Open No. 2006-73945 Summary of the Invention [Problem to be solved by the invention]

[0005] In the manufacturing process of three-dimensional integrated circuits (3DIC), processing such as electrode formation after polishing a substrate that has been temporarily fixed (temporarily adhered) to a fixing member (support) with a temporary fixative (adhesive) may be carried out at high temperatures of 150°C or higher.If the temporary fixative (adhesive) is altered by heating, it becomes difficult to remove the temporary fixative residue (adhesive residue) that remains on the semiconductor substrate after the fixing member is separated. When a film-like temporary fixing agent (adhesive sheet) is used as the temporary fixing agent, the film-like temporary fixing agent (adhesive sheet) remaining after separation of the fixing member is usually peeled off as proposed in Patent Document 1. Here, peeling of a film-like temporary fixing agent means peeling off the film (temporary fixing agent) while holding the edge of the film of the temporary fixing agent. In recent years, the above processing has been carried out under higher temperature conditions than before, and heat-resistant temporary fixing agents (adhesives) have begun to be used. When these new temporary fixing agents (adhesives) are used, small pieces of temporary fixing agent residue (adhesive residue) tend to remain on the substrate after peeling. Such small pieces of temporary fixing agent residue (adhesive residue) are more difficult to remove and can cause stains on the substrate surface after drying.

[0006] Therefore, the present disclosure provides a method for manufacturing a semiconductor substrate that can suppress the occurrence of stains on the substrate surface after drying. [Means for solving the problem]

[0007] In one aspect, the present disclosure relates to a method for manufacturing a semiconductor substrate, including the following steps 1, 2, and 3, further including, before step 1, a step of subjecting the semiconductor substrate to which a temporary fixing agent has been adhered to a peeling treatment to remove the temporary fixing agent. Step 1: A step of cleaning the semiconductor substrate with residual temporary fixing agent after peeling with a cleaning agent. Step 2: A step of rinsing the semiconductor substrate after step 1, which includes rinsing with a solvent that has an affinity for both a hydrophobic solvent and water. Step 3: Drying the semiconductor substrate after step 2 using a spin processor. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to provide a method for manufacturing a semiconductor substrate that can suppress the occurrence of stains on the surface of the substrate after drying. DETAILED DESCRIPTION OF THE INVENTION

[0009] The present disclosure is based on the finding that the occurrence of stains on the surface of the substrate after drying can be suppressed by removing the temporary fixing agent (adhesive) residue remaining on the substrate after peeling treatment with a cleaning agent, followed by a rinsing treatment with a specific solvent and a drying treatment using a spin processor.

[0010] In one aspect, the present disclosure relates to a method for manufacturing a semiconductor substrate, including the following steps 1, 2, and 3, which further includes, before step 1, a step of subjecting the semiconductor substrate to which a temporary fixing agent has been adhered to a peeling treatment to remove the temporary fixing agent (hereinafter also referred to as the "semiconductor substrate manufacturing method of the present disclosure"). Step 1: A step of cleaning the semiconductor substrate with residual temporary fixing agent after peeling with a cleaning agent. Step 2: A step of rinsing the semiconductor substrate after step 1, which includes rinsing with a solvent that has an affinity for both a hydrophobic solvent and water. Step 3: Drying the semiconductor substrate after step 2 using a spin processor.

[0011] According to the present disclosure, it is possible to provide a method for manufacturing a semiconductor substrate that can suppress the occurrence of stains on the substrate surface after drying, and to obtain high-quality semiconductor substrates with a high yield.

[0012] Although the details of the mechanism of action by which the effects of the present disclosure are manifested are still unclear, it is presumed as follows. On the surface of a substrate coated with a temporary fixative and then peeled off by a peeling process, not only temporary fixative residue of a size that can be seen with the naked eye but also temporary fixative residue of a size that cannot be seen with the naked eye may be present. While temporary fixative residue of a size that can be seen with the naked eye can be removed using a cleaning agent, tiny temporary fixative residue that cannot be seen with the naked eye may change the hydrophilicity of the surface, causing water or alcohol used in rinsing to remain, which may cause stains after drying. Therefore, in the present disclosure, it is believed that the occurrence of stains on the substrate after drying can be prevented by cleaning a substrate with temporary fixative residue attached, followed by a rinsing process that includes a treatment with a specific solvent and a drying process using a spin processor. However, the present disclosure need not be construed as being limited to this mechanism.

[0013] Examples of the semiconductor substrate include a silicon substrate (wafer), a silicon carbide substrate (wafer), a germanium substrate (wafer), a gallium nitride substrate (wafer), a gallium arsenide substrate (wafer), a gallium phosphide substrate (wafer), a gallium arsenide-aluminum substrate (wafer), etc. In one or more embodiments, the semiconductor substrate may be a substrate (wafer) having pads and / or lands that are sites for bonding and mounting.

[0014] Examples of temporary fixing agents (adhesives) include those that can bond (temporarily fix, adhere) a semiconductor substrate to a fixing member, have durability that can withstand polishing and processing, and allow the semiconductor substrate to be easily separated from the fixing member. Examples of temporary fixing agents (adhesives) include polyimide-based, polysiloxane-based, acrylic-based, and methacrylic-based temporary fixing agents (adhesives). The temporary fixing agent (adhesive) may be in the form of, for example, a film, and examples of the film-shaped temporary fixing agent include an adhesive sheet, an adhesive film, and an adhesive tape. The thickness of the temporary fixing agent (adhesive) is, for example, 5 μm or more and 500 μm or less, and preferably 10 μm or more and 100 μm or less. In the present disclosure, temporary fixing agent residue (adhesive residue) refers to residue derived from the temporary fixing agent (adhesive) remaining on a semiconductor substrate after a semiconductor substrate to which a temporary fixing agent (adhesive) has been adhered is subjected to a peeling process; more specifically, it refers to residue derived from the temporary fixing agent (adhesive) remaining on the semiconductor substrate after a semiconductor substrate adhered to a fixing member using the temporary fixing agent (adhesive) is separated from the fixing member and subjected to a peeling process.

[0015] [Peeling process] The semiconductor substrate manufacturing method of the present disclosure includes a step (hereinafter also referred to as a "peeling treatment step") of peeling the semiconductor substrate to which the temporary fixing agent has been adhered to remove the temporary fixing agent, prior to the following cleaning step (step 1). Examples of peeling methods include laser peeling and mechanical peeling. In one or more embodiments, the peeling treatment step is a step of peeling a semiconductor substrate to which a film-like temporary fixing agent is adhered, thereby peeling off the film-like temporary fixing agent. Here, in one or more embodiments, peeling of a film-like temporary fixing agent refers to peeling off the film (temporary fixing agent) while holding the edge of the film that is the temporary fixing agent.

[0016] [Step 1: Cleaning] Step 1 in the semiconductor substrate manufacturing method of the present disclosure is a step (hereinafter also referred to as a "cleaning step") in which the semiconductor substrate (hereinafter also referred to as an "object to be cleaned") having temporary fixing agent residue attached thereto after the peeling process is cleaned with a cleaning agent. In one or more embodiments, the cleaning step is a step of removing, with a cleaning agent, a temporary fixing agent residue remaining on a semiconductor substrate after a peeling treatment. In one or more embodiments, the object to be cleaned in step 1 is a semiconductor substrate to which a temporary fixing agent has been attached, after the semiconductor substrate has been subjected to a peeling treatment. In step 1, the temporary fixing agent residue adhering to the semiconductor substrate is a residue derived from the temporary fixing agent remaining on the semiconductor substrate after the peeling treatment.

[0017] The cleaning method in step 1 (method for removing temporary fixing agent residue) can be, for example, immersion cleaning. The immersion conditions for immersion cleaning are, for example, preferably a cleaning agent temperature of 40°C or higher and 70°C or lower, and a immersion time of 1 minute or higher and 60 minutes or lower. Ultrasonic vibrations may be applied to the cleaning agent, and examples of ultrasonic conditions include 25 to 50 kHz or 35 to 45 kHz. Spin cleaning can also be used.

[0018] (cleaning agent) The cleaning agent used in step 1 may be a conventionally known cleaning agent. For example, the cleaning agent may include a cleaning agent containing at least one selected from an organic solvent and an amine. In one or more embodiments, the cleaning agent used in step 1 contains an organic solvent, and in one or more embodiments, the cleaning agent contains an amine. Examples of the organic solvent include glycol ethers and hydrocarbons. In one or more embodiments, the cleaning agent used in step 1 contains a glycol ether, a hydrocarbon, and an amine.

[0019] <Glycol ether> The glycol ether may contain, for example, a compound represented by the following formula (I): The glycol ether may be one type or a combination of two or more types. The content of the compound represented by the following formula (I) in the glycol ether is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 100% by mass. RO-(AO) n -H (I) In the above formula (I), R represents a hydrocarbon group having 1 to 6 carbon atoms, AO represents an ethyleneoxy group (EO) or a propyleneoxy group (PO), and n is the number of moles of AO added, which is a number of 1 to 3. In the above formula (I), from the viewpoint of improving the removability of the adhesive, R is preferably a phenyl group or an alkyl group having 1 to 6 carbon atoms, more preferably an alkyl group having 1 to 6 carbon atoms, and even more preferably an alkyl group having 1 to 4 carbon atoms. From the same viewpoint, AO is preferably an ethyleneoxy group (EO). From the same viewpoint, n is preferably 1 to 3. Examples of the compound represented by formula (I) include monophenyl ethers such as ethylene glycol monophenyl ether, diethylene glycol monophenyl ether, and triethylene glycol monophenyl ether; and monoalkyl ethers having an alkyl group of 1 to 6 carbon atoms, such as ethylene glycol monoalkyl ether, diethylene glycol monoalkyl ether, triethylene glycol monoalkyl ether, and tripropylene glycol monoalkyl ether. Among these, from the viewpoint of improving the removability of the adhesive, the compound represented by formula (I) is more preferably at least one selected from ethylene glycol monoalkyl ether, diethylene glycol monoalkyl ether, triethylene glycol monoalkyl ether, and tripropylene glycol monoalkyl ether, each having an alkyl group of 1 to 6 carbon atoms, and even more preferably at least one selected from ethylene glycol monobutyl ether, diethylene glycol monobutyl ether (BDG), and propylene glycol monomethyl ether (PGME). In one or more embodiments, the glycol ether has a solubility in water at 20°C of more than 10% by mass. As the glycol ether, from the viewpoint of improving the removability of the adhesive, a diethylene glycol monoalkyl ether having an alkyl group having 1 to 6 carbon atoms is preferred, and diethylene glycol monobutyl ether (BDG) is more preferred. When the cleaning agent contains glycol ether, the content of glycol ether in the cleaning agent is preferably 10% by mass or more, more preferably 15% by mass or more, from the viewpoints of improving adhesive removability and compatibility, and is preferably 65% ​​by mass or less, more preferably 60% by mass or less, from the viewpoint of improving adhesive removability. More specifically, the content of glycol ether in the cleaning agent is, for example, 10% by mass or more and 65% by mass or less, or 15% by mass or more and 60% by mass or less. When two or more glycol ethers are used in combination, the content of glycol ether refers to the total content of the glycol ethers.

[0020] <Hydrocarbons> In one or more embodiments, the hydrocarbon is a hydrocarbon-based organic solvent. From the viewpoint of improving adhesive removability, hydrocarbons having a cyclic structure are preferred, and organic solvents such as alicyclic hydrocarbons and aromatic hydrocarbons are more preferred. Examples of alicyclic hydrocarbons include cycloalkanes such as cyclohexane. Examples of aromatic hydrocarbons include toluene, ethylbenzene, xylene, and mesitylene (1,3,5-trimethylbenzene). The hydrocarbon may be one type or a combination of two or more types. The total content of alicyclic hydrocarbons and aromatic hydrocarbons in the hydrocarbon is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 100% by mass. From the viewpoint of improving the removability of the adhesive, the number of carbon atoms in the hydrocarbon is preferably 5 or more, more preferably 6 or more, and from the same viewpoint, it is preferably 14 or less, more preferably 12 or less, even more preferably 10 or less, and even more preferably 9 or less. When the hydrocarbon is an alicyclic hydrocarbon, the number of carbon atoms in the alicyclic hydrocarbon is preferably 5 or more, and preferably 14 or less, more preferably 10 or less, and even more preferably 8 or less, from the same viewpoint. When the hydrocarbon is an aromatic hydrocarbon, the number of carbon atoms in the aromatic hydrocarbon is, from the same viewpoint, preferably 5 or more, more preferably 6 or more, even more preferably 7 or more, and preferably 14 or less, more preferably 12 or less, even more preferably 10 or less, and even more preferably 9 or less. Examples of hydrocarbons include at least one selected from ethylbenzene, xylene, mesitylene, and cyclohexane, and from the viewpoints of improving adhesive removability, storage stability, availability, and chemical substance regulations, ethylbenzene or xylene is preferred. Examples of hydrocarbons include at least one selected from alicyclic hydrocarbons and aromatic hydrocarbons. From the viewpoint of improving the removability of the adhesive, aromatic hydrocarbons are preferred, aromatic hydrocarbons having 5 to 14 carbon atoms are more preferred, aromatic hydrocarbons having 6 to 12 carbon atoms are even more preferred, aromatic hydrocarbons having 7 to 10 carbon atoms are even more preferred, aromatic hydrocarbons having 7 to 9 carbon atoms are even more preferred, at least one selected from ethylenebenzene, xylene, and methylenebenzene is even more preferred, and ethylbenzene is even more preferred. The hydrocarbon content in the cleaning agent is preferably 10% by mass or more, more preferably 15% by mass or more, and 25% by mass or more from the viewpoint of improving adhesive removability, and is preferably 90% by mass or less, more preferably 80% by mass or less, and even more preferably 75% by mass or less from the viewpoint of compatibility. More specifically, the hydrocarbon content in the cleaning agent is preferably, for example, 10% by mass or more and 80% by mass or less, or 10% by mass or more and 90% by mass or less, or 15% by mass or more and 90% by mass or less, or 25% by mass or more and 80% by mass or less, or 25% by mass or more and 75% by mass or less. When two or more hydrocarbons are used in combination, the hydrocarbon content refers to the total content of those hydrocarbons.

[0021] <amine> Examples of the amine include alkanolamines (amino alcohols). Examples of the alkanolamines (amino alcohols) include those containing a compound represented by the following formula (II). The amine may be one type or a combination of two or more types. In one or more embodiments, the alkanolamine is a compound that does not have a branched carbon chain. The content of the compound represented by the following formula (II) in the alkanolamine is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 100% by mass. [ka] In the above formula (II), R 1 represents a linear alkanol group having 2 to 4 carbon atoms, and R 2represents 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 removability of the adhesive, R is preferably a linear alkanol group having 2 or 3 carbon atoms. 2 From the same viewpoint, R is preferably a hydrogen atom. 3 From the same viewpoint, is preferably a hydrogen atom. Examples of amines 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, from the viewpoint of improving adhesive removability, alkylmonoalkanolamines or monoalkanolamines are preferred, and monoethanolamine is more preferred. The amine content in the cleaning agent is preferably 3% by mass or more, more preferably 5% by mass or more, and even more preferably 8% by mass or more from the viewpoint of improving adhesive removability, reducing component damage, and reducing nitrogen content, and is preferably 50% by mass or less, more preferably 45% by mass or less, and even more preferably 40% by mass or less. More specifically, the amine content in the cleaning agent is preferably, for example, 3% by mass or more and 50% by mass or less, or 5% by mass or more and 45% by mass or less, or 8% by mass or more and 40% by mass or less. When two or more amines are used in combination, the amine content refers to the total content of those amines.

[0022] <Mass ratio (amine / glycol ether)> The mass ratio of amine to glycol ether (amine / glycol ether) in the cleaner is preferably 0.01 or more, more preferably 0.05 or more, and even more preferably 0.1 or more, from the viewpoint of improving adhesive removability, and from the same viewpoint, is preferably 10 or less, more preferably 5 or less, and even more preferably 2 or less. <Mass ratio (amine / hydrocarbon)> The mass ratio of amine to hydrocarbon (amine / hydrocarbon) in the precleaning agent is preferably 0.01 or more, more preferably 0.05 or more, and even more preferably 0.1 or more, from the viewpoint of improving adhesive removability, and from the same viewpoint, is preferably 10 or less, more preferably 5 or less, and even more preferably 1 or less. <Mass ratio (glycol ether / hydrocarbon)> The mass ratio of glycol ether to hydrocarbon (glycol ether / hydrocarbon) in the pre-cleaning agent is preferably 0.01 or more, more preferably 0.1 or more, and even more preferably 0.2 or more, from the viewpoint of improving adhesive removability, and from the same viewpoint, is preferably 10 or less, more preferably 5 or less, and even more preferably 1 or less.

[0023] <Other ingredients> In one or more embodiments, the cleaning agent may further contain water and other components as needed. Examples of the other components include components that can be used in ordinary cleaning agents, such as solvents other than organic solvents, alkali agents other than amines, surfactants, chelating agents, thickeners, dispersants, rust inhibitors, polymeric compounds, solubilizers, antioxidants, preservatives, antifoaming agents, and antibacterial agents.

[0024] In the present disclosure, the "content of each component in the detergent" refers to the content of each component at the time of cleaning, i.e., at the time when the detergent begins to be used for cleaning. In one or more embodiments, the cleaning agent can be produced by blending an organic solvent and / or an amine, and, if necessary, the above-mentioned optional components (water and other components) using a known method.

[0025] [Step 2: Rinse] Step 2 in the semiconductor substrate manufacturing method of the present disclosure is a step of rinsing the semiconductor substrate after step 1 (hereinafter also referred to as the "rinsing step"), which includes rinsing with a solvent (rinse liquid) that has affinity for both a hydrophobic solvent and water.

[0026] In one or more embodiments, the solvent having affinity for both the hydrophobic solvent and water used in step 2 is an alcohol, and preferred examples thereof include isopropyl alcohol (IPA) and ethanol. The temperature of the solvent having affinity for both the hydrophobic solvent and water used in step 2 is preferably 10°C or higher, more preferably 15°C or higher, and even more preferably 20°C or higher from the viewpoint of suppressing stain formation, and is preferably 60°C or lower, more preferably 45°C or lower, and even more preferably 30°C or lower from the viewpoint of safety. The time (rinsing time) for the rinsing treatment with the solvent having affinity for both the hydrophobic solvent and water used in step 2 is preferably 5 seconds or more, more preferably 10 seconds or more, and even more preferably 15 seconds or more from the viewpoint of suppressing the occurrence of stains, and is preferably 300 seconds or less, more preferably 120 seconds or less, and even more preferably 60 seconds or less from the viewpoint of productivity. Here, the rinsing time refers to the time during which the rinse liquid is supplied.

[0027] In one or more embodiments, step 2 can further include rinsing the semiconductor substrate with water (rinse liquid) after the rinsing process with the solvent having affinity for both the hydrophobic solvent and water (water rinse). The temperature of the water used for the water rinse is preferably 10°C or higher, more preferably 15°C or higher, and even more preferably 20°C or higher from the viewpoint of preventing stains, and is preferably 60°C or lower, more preferably 45°C or lower, and even more preferably 30°C or lower from the viewpoint of safety. The rinsing time with water is preferably 1 minute or longer, more preferably 2 minutes or longer, and even more preferably 3 minutes or longer from the viewpoint of suppressing stain formation, and is preferably 6 minutes or shorter, more preferably 5 minutes or shorter, and even more preferably 4 minutes or shorter from the viewpoint of productivity.

[0028] The method of rinsing in step 2 is not particularly limited, and can be a method generally used for cleaning substrates in the manufacturing process of semiconductor substrates, such as a method of immersing the substrate in a rinse solution, a method of pouring a rinse solution over the substrate, a method of supplying a rinse solution to the substrate while spinning the substrate, etc. Among these, a method of supplying a rinse solution to the substrate while spinning is preferred. An example of a method of supplying a rinse solution to the substrate while spinning is the use of a spin processor. When the rinsing treatment in step 2 includes a rinsing treatment with a solvent and a rinsing treatment with water, it is preferable that at least one of the rinsing treatments is carried out in a spin processor. Therefore, in one or more embodiments, in step 2, the rinsing treatment with a solvent having an affinity for both the hydrophobic solvent and water is performed using a spin processor. In one or more other embodiments, in step 2, the rinsing treatment with water is performed using a spin processor. The rotation speed of the spin processor used in step 2 is preferably 50 rpm or more, more preferably 75 rpm or more, and even more preferably 100 rpm or more from the viewpoint of suppressing the occurrence of stains, and is preferably 3000 rpm or less, more preferably 2500 rpm or less, and even more preferably 2000 rpm or less from the viewpoint of safety. More specifically, the rotation speed of the spin processor used in step 2 is preferably 50 rpm or more and 3000 rpm or less, more preferably 75 rpm or more and 2500 rpm or less, and even more preferably 100 rpm or more and 2000 rpm or less.

[0029] [Step 3: Drying] Step 3 in the semiconductor substrate manufacturing method of the present disclosure is a step of drying the semiconductor substrate after step 2 using a spin processor (hereinafter also referred to as a "drying step").

[0030] The drying time in step 3 is preferably 1 minute or more, more preferably 2 minutes or more, and even more preferably 3 minutes or more from the viewpoint of suppressing stain formation, and is preferably 10 minutes or less, more preferably 8 minutes or less, and even more preferably 6 minutes or less from the viewpoint of productivity. The drying temperature in step 3 is preferably 10°C or higher, more preferably 15°C or higher, and even more preferably 20°C or higher from the viewpoint of productivity, and is preferably 100°C or lower, more preferably 80°C or lower, and even more preferably 60°C or lower from the viewpoint of safety. The drying method in step 3 is spin drying using a spin processor, and a preferred example is spin drying under an inert gas (such as nitrogen gas) blow.

[0031] The rotation speed of the spin processor used in step 3 is preferably 300 rpm or more, more preferably 600 rpm or more, and even more preferably 1000 rpm or more from the viewpoint of suppressing staining, and is preferably 3000 rpm or less, more preferably 2500 rpm or less, and even more preferably 2000 rpm or less from the viewpoint of safety. More specifically, the rotation speed of the spin processor used in step 3 is preferably 300 rpm or more and 3000 rpm or less, more preferably 600 rpm or more and 2500 rpm or less, and even more preferably 1000 rpm or more and 2000 rpm or less.

[0032] In one or more embodiments, the rotation speed of the spin processor used in step 3 (hereinafter also referred to as "the rotation speed of step 3") is equal to or greater than the rotation speed of the spin processor used in step 2 (hereinafter also referred to as "the rotation speed of step 2"). The spin ratio between the rotation speed of the spin processor used in step 3 and the rotation speed of the spin processor used in step 2 [rotation speed in step 3 / rotation speed in step 2] is preferably 1 or more, more preferably 2 or more, and even more preferably 3 or more from the viewpoint of suppressing the occurrence of stains, and is preferably 10 or less, more preferably 9 or less, and even more preferably 8 or less from the viewpoint of safety. More specifically, the spin ratio [rotation speed in step 3 / rotation speed in step 2] is preferably 1 or more and 10 or less, more preferably 2 or more and 9 or less, and even more preferably 3 or more and 8 or less.

[0033] In one or more embodiments, the semiconductor substrate manufacturing method of the present disclosure may further include, before the peeling treatment step, a bonding step (a), a polishing step (b), a processing step (c), and a separation step (d). (a) A bonding process in which the substrate is bonded to the fixing member using a temporary fixing agent (adhesive). (b) A polishing step for polishing the backside of the substrate that is bonded to the fixing member. (c) A processing step for processing the polished surface of the substrate. (d) A separation step of separating the processed substrate from the fixing member. Each of the above steps will be explained below.

[0034] <Process (a): Adhesion process> Step (a) is a step (adhesion step) of adhering a substrate to a fixing member with a temporary fixing agent (adhesive). In one or more embodiments, step (a) includes step (a1) of applying a temporary fixing agent (adhesive) to the surface of the substrate or the fixing member to form a temporary fixing agent layer (adhesive layer), and step (a2) of bonding the substrate and the fixing member together via the temporary fixing agent layer (adhesive layer) and performing a heat treatment to bond them.

[0035] The substrate used in step (a) may be, for example, a silicon substrate (wafer) or a glass substrate (wafer) having a diameter of 100 to 500 mm and a thickness of 500 to 2000 μm. The fixing member used in step (a) is not particularly limited, but examples thereof include substrates such as silicon substrates (wafers) and glass plates having a diameter of 100 to 500 mm and a thickness of 500 to 20,000 μm.

[0036] The temporary fixing agent (adhesive) used in step (a) is not particularly limited as long as it can bond the substrate to the fixing member, has durability sufficient to withstand the polishing step and the processing step, and allows the substrate to be easily separated from the fixing member in the separation step. For example, the temporary fixing agent (adhesive) used in the manufacturing process of 3DIC can be mentioned. Examples of the temporary fixing agent (adhesive) used in the manufacturing process of 3DIC include polyimide-based, polysiloxane-based, acrylic-based, or methacrylic-based adhesives (adhesive compositions). Specifically, the adhesive composition described in JP 2021-161196 A can be mentioned. In one or more embodiments, the temporary fixing agent (adhesive) used in step (a) may contain polysiloxane, an acrylic acid ester, or a methacrylic acid ester as an adhesive component, and may further contain a platinum group metal catalyst, a release agent component, a solvent, etc. The viscosity of the temporary fixing agent (adhesive) used in step (a) can be adjusted by appropriately changing the concentration of the components contained therein depending on the application method, film thickness, and the like.

[0037] In the step (a1), the method for applying the temporary fixing agent (adhesive) is not particularly limited, but examples thereof include spin coating. The film thickness of the coating layer (temporary fixing agent layer, adhesive layer) of the temporary fixing agent (adhesive) is, for example, 5 to 500 μm.

[0038] In step (a2), the temperature for the heat treatment is, for example, 80° C. or higher, and is preferably 150° C. or lower in order to prevent the adhesive from being excessively hardened. The heat treatment time is, for example, 30 seconds or more, and is preferably 10 minutes or less from the viewpoint of suppressing deterioration of the temporary fixing agent layer (adhesive layer) and other members. Heating can be carried out using a hot plate, an oven, or the like. The film thickness of the temporary fixing agent layer (adhesive layer) after the heat treatment is, for example, 5 μm or more and 500 μm or less.

[0039] <Process (b): Polishing process> Step (b) is a step (polishing step) of polishing the back surface (surface opposite to the adhesive surface) of the substrate that is bonded to the fixing member. Examples of the polishing method include mechanical polishing using abrasive grains and chemical mechanical polishing. In step (b), the thickness of the substrate (thinned substrate) after polishing is preferably 200 μm or less, for example, 50 μm to 200 μm.

[0040] <Process (c): Processing process> Step (c) is a step (processing step) of processing the polished surface of the substrate (the back surface of the thinned substrate). In one or more embodiments, step (c) may be an electrode formation step, a metal wiring formation step, a protective film formation step, etc. Examples of such steps include conventionally known processing steps such as metal sputtering for forming electrodes, wet etching, resist application, pattern formation, resist stripping, dry etching, metal plating, silicon etching for forming through-silicon vias (TSVs), and oxide film formation on silicon surfaces. In one or more embodiments, the processing in step (c) is carried out at a high temperature of 150° C. or higher. When forming electrodes such as TSVs, a heat treatment may be carried out at, for example, 250° C. or higher and 350° C. or lower. The film thickness of the film-like temporary fixing agent (adhesive sheet) after the heat treatment at high temperature may be, for example, 5 μm or higher and 500 μm or lower.

[0041] <Step (d): Separation step> Step (d) is a step (separation step) of separating the processed substrate from the fixing member. Examples of the separation method include solvent peeling, laser peeling, and mechanical peeling. In one or more embodiments, a film-like temporary fixing agent (adhesive) is adhered (attached) to the substrate after the fixing member is separated.

[0042] [Items to be cleaned] An example of the object to be cleaned is a semiconductor substrate to which residual temporary fixing agent (adhesive) remains have been attached after peeling. Examples of the semiconductor substrate include silicon substrates (wafers), silicon carbide substrates (wafers), germanium substrates (wafers), gallium nitride substrates (wafers), gallium arsenide substrates (wafers), gallium phosphide substrates (wafers), and gallium arsenide aluminum substrates (wafers). In one or more embodiments, the substrate (wafer) may include a substrate (wafer) having pads and / or lands that serve as bonding and mounting sites. Examples of materials for the pads and lands include metals such as gold and copper. In one or more embodiments, examples of the semiconductor substrate having a temporary fixing agent (adhesive) residue attached thereto after the peeling treatment include a substrate obtained by subjecting a semiconductor substrate having a temporary fixing agent (adhesive) adhered thereto to a peeling treatment, a substrate obtained by subjecting a substrate temporarily fixed (adhered) to a fixing member with a temporary fixing agent (adhesive) to a peeling treatment after being separated from the fixing member, etc. In one or more embodiments, examples of the substrate obtained by subjecting the substrate to a peeling treatment after being separated from the fixing member include a substrate (wafer) having metal pads to which a temporary fixing agent (adhesive) residue has adhered. In one or more embodiments, the semiconductor substrate having residual temporary fixing agents (adhesives) attached thereto after peeling treatment may be a semiconductor substrate having residual temporary fixing agents (adhesives) attached thereto after peeling treatment, which is used in the manufacturing process of three-dimensional integrated circuits (3DIC). In one or more embodiments, the semiconductor substrate having the residual temporary fixing agent (adhesive) attached thereto after the peeling treatment has been subjected to a heat treatment at a temperature of 230° C. or higher. In one or more embodiments, the heat treatment may be the heat treatment in the processing step described above.

[0043] [Finishing method] In one aspect, the present disclosure relates to a finishing treatment method (hereinafter also referred to as the "finishing treatment method of the present disclosure") in which a semiconductor substrate bonded to a fixing member with a temporary fixing agent is separated from the fixing member, and the semiconductor substrate (object to be cleaned) having temporary fixing agent residue attached thereto is subjected to a peeling treatment and then cleaned with a cleaning agent, followed by a finishing treatment. Examples of objects to be cleaned in the finishing treatment method of the present disclosure include the objects described above. Examples of cleaning agents in the finishing treatment method of the present disclosure include the cleaning agent used in step 1 of the semiconductor substrate manufacturing method of the present disclosure described above. In one or more embodiments, the finishing method of the present disclosure includes a step of rinsing the semiconductor substrate after the cleaning process, which includes rinsing with a solvent that has affinity for both a hydrophobic solvent and water (rinsing step), and a step of drying the semiconductor substrate after the rinsing process using a spin processor (drying step). In one or more embodiments, the rinsing treatment in the rinsing step of the finishing treatment method of the present disclosure may be the same as the rinsing treatment in step 2 of the semiconductor substrate manufacturing method of the present disclosure described above. The drying method in the drying step of the finishing method of the present disclosure may be the same as the drying method in step 3 of the semiconductor substrate manufacturing method of the present disclosure described above. Examples of the temporary fixing agent include the temporary fixing agent in the semiconductor substrate manufacturing method of the present disclosure described above. [Example]

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

[0045] 1. Preparation of Cleaning Agent The components shown in Table 1 were blended in the amounts (% by mass, active ingredient) shown in Table 1, and the blended mixture was stirred and mixed to prepare a cleaning agent.

[0046] The following was used to prepare the detergent: MEA: Monoethanolamine [manufactured by Nippon Shokubai Co., Ltd.] BDG: Butyl diglycol [Nihon Nyukazai Co., Ltd., diethylene glycol monobutyl ether] Ethylbenzene [Fujifilm Wako Pure Chemical Industries, Ltd.]

[0047] [Table 1]

[0048] 2. Evaluation of Finishing Treatment (Example 1, Comparative Examples 1 and 2) The test pieces described below were subjected to the cleaning treatment and finishing treatment (rinsing and drying) described below, and the appearance was evaluated. [Test piece] The test piece was 200 mm x 200 mm in size and consisted of a silicon wafer (725 μm thick) with temporary fixative residue present on the entire surface of the test piece. The test piece was prepared by coating a silicon wafer with a temporary fixative (80 μm thick, film-like) and then removing the temporary fixative by a peeling process (mechanical peeling). The peeling process was performed by pinching the edge of the film-like temporary fixative with tweezers and peeling it off. An acrylic temporary fixing agent was used as the temporary fixing agent. 1 to 50 μm on the silicon wafer after peeling 2 Scanning electron microscopy (SEM) revealed the presence of a large amount of temporary fixative residue, approximately the size of a small particle. [Cleaning process] 20 L of the cleaning agent was added to a stainless steel beaker and heated to 60° C. The test piece was immersed in the cleaning agent at 60° C. for 10 minutes. [Finishing process (rinsing, drying)] Example 1 Rinse treatment: The test piece was removed from the cleaner and rinsed with isopropyl alcohol (IPA, Fujifilm Wako Pure Chemical Industries, Ltd., 25°C) for 20 seconds, followed by a rinse with water (25°C) for 3 minutes at 300 rpm using a spin processor (Kanamex Corporation). Drying treatment: After rinsing, the test piece was dried (25° C.) for 5 minutes using a spin processor (manufactured by Kanamex Corporation) at a rotation speed of 1500 rpm. (Comparative Examples 1 and 2) Rinse treatment: The test piece was removed from the cleaner and rinsed by pouring water (25°C, Comparative Example 1) or IPA (25°C, Comparative Example 2) over it for 20 seconds. Drying treatment: After rinsing, the test piece was left to dry (25°C). [evaluation] The appearance of the test piece after the finishing treatment was visually observed under a microscope, and the appearance was evaluated based on the following criteria. <Appearance criteria> A: No stains are visible on the surface of the test piece even at 1000x magnification. B: At a magnification of 500x or more but less than 1000x, stains are visible on the surface of the test piece. C: At magnifications of 100x or more but less than 500x, stains are visible on the surface of the test piece. D: Even at magnifications of less than 100x, stains are visible on the surface of the test piece.

[0049] [Table 2]

[0050] As shown in Table 2, in Example 1, in which spin drying was performed after rinsing with IPA and water, no stains were observed on the dried wafer surface, whereas in Comparative Examples 1 and 2, in which the wafer was left to dry after rinsing with water or IPA, stains were observed on the dried wafer surface. Therefore, it was found that by performing a specific finishing process (rinsing process and spin drying) after the cleaning process of a semiconductor substrate having temporary fixing agent residue attached thereto, it is possible to prevent stains from occurring on the dried substrate surface. [Industrial Applicability]

[0051] According to the present disclosure, it is possible to provide a method for manufacturing a semiconductor substrate that can suppress the occurrence of stains on the substrate surface after drying, thereby improving the productivity of semiconductor substrates.

Claims

1. A method for manufacturing a semiconductor substrate, comprising the following steps 1, 2, and 3: The method for manufacturing a semiconductor substrate further includes, before step 1, a step of subjecting the semiconductor substrate to a peeling treatment to remove the temporary fixing agent. Step 1: A step of cleaning the semiconductor substrate having the temporary fixing agent residue attached thereto after the peeling treatment with a cleaning agent. Step 2: A step of rinsing the semiconductor substrate after step 1, which includes rinsing with a solvent that has an affinity for both a hydrophobic solvent and water. Step 3: Drying the semiconductor substrate after step 2 using a spin processor.

2. The method according to claim 1, wherein the solvent having an affinity for both the hydrophobic solvent and water used in step 2 is an alcohol.

3. 2. The method according to claim 1, wherein the rotation speed of the spin processor used in step 3 is 300 rpm or more and 3,000 rpm or less.

4. The manufacturing method according to claim 1 , wherein the temporary fixing agent is in the form of a film.

5. The manufacturing method according to claim 1, wherein the thickness of the temporary fixing agent is 5 μm or more and 500 μm or less.

6. The manufacturing method according to claim 1 , wherein the thickness of the temporary fixing agent is 10 μm or more and 100 μm or less.

7. The method according to claim 1 , wherein the cleaning agent used in step 1 contains an organic solvent.

8. The method of claim 1 , wherein the cleaning agent used in step 1 contains an amine.

9. The manufacturing method according to claim 1 , wherein in step 2, the rinsing treatment with the solvent having an affinity for both the hydrophobic solvent and water is carried out using a spin processor.

10. The manufacturing method according to claim 1 , wherein step 2 further comprises rinsing the semiconductor substrate with water after the rinsing treatment with the solvent having an affinity for both the hydrophobic solvent and water.

11. The manufacturing method according to claim 10 , wherein in step 2, the rinsing treatment with water is performed using a spin processor.

12. The method according to claim 9 or 11, wherein the rotation speed of the spin processor used in step 2 is 50 rpm or more and 3000 rpm or less.

13. 12. The method according to claim 9, wherein the rotation speed of the spin processor used in step 3 is equal to or greater than the rotation speed of the spin processor used in step 2.

14. 12. The method according to claim 9, wherein the spin ratio between the rotation speed of the spin processor used in step 3 and the rotation speed of the spin processor used in step 2 [rotation speed in step 3 / rotation speed in step 2] is 1 or more and 10 or less.

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