Method for manufacturing semiconductor substrate

Abstract

The purpose of the present invention according to one embodiment is to provide a method for manufacturing a semiconductor substrate capable of suppressing the incidence of staining on the surface of a dried substrate.　The present disclosure according to one embodiment relates to a method for manufacturing a semiconductor substrate comprising steps 1, 2, and 3 below, the method further comprising, prior to step 1, a step for subjecting the semiconductor substrate to which a temporary fixing agent has been bonded to a peeling process so as to remove the temporary fixing agent. Step 1) A step for cleaning, using a cleaning agent, the semiconductor substrate to which temporary fixing agent residue has adhered after the peeling treatment; step 2) a step for rinsing the semiconductor substrate obtained after step 1, the step further comprising rinsing the semiconductor substrate using a solvent having affinity for both the hydrophobic solvent and water; and step 3) a step for drying the semiconductor substrate obtained after step 2 using a spin processor

Description

Semiconductor substrate manufacturing method

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

[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) or the like. When stacking substrates in multiple layers, it is necessary to thin the back surface (the surface on which no circuit is formed) of the substrate on which a circuit is formed by polishing, and then to form electrodes on the back surface. Before thinning, the substrate is temporarily fixed (temporarily bonded) to a fixing member (support) with a temporary fixing agent (adhesive). After polishing, electrode formation, and other processing, the substrate is separated from the fixing member. The temporary fixing agent (adhesive) often remains on the substrate 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, Japanese Patent Laid-Open No. 2010-28063 (Patent Document 1) proposes a sheet peeling method in which an adhesive sheet is peeled from an adherend by relative movement between an adherend having an adhesive sheet attached to its surface and a release tape attached to the adhesive sheet. Also, Japanese Patent Laid-Open No. 2023-184484 (Patent Document 2) proposes a cleaning composition for removing adhesive remaining on a wafer, which contains a glycol ether, a hydrocarbon, and an alkanolamine having a linear alkanol group, and which is water-free or contains 10 mass% or less of water, and in which the mass ratio of the glycol ether content to the hydrocarbon content (glycol ether / hydrocarbon) is 1.7 or less. Japanese Patent Laid-Open No. 2006-73945 (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 the 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.

[0004] 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 peeling the semiconductor substrate to which a temporary fixing agent is adhered, to remove the temporary fixing agent. Step 1: A step of cleaning the semiconductor substrate, to which the temporary fixing agent residue adheres after the peeling process, with a cleaning agent. Step 2: A step of rinsing the semiconductor substrate after step 1, which includes a rinsing process with a solvent that has affinity for both a hydrophobic solvent and water. Step 3: A step of drying the semiconductor substrate after step 2 using a spin processor.

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

[0007] 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.

[0008] The present disclosure is based on the finding that removing residual temporary fixing agent (adhesive) remaining on a substrate after a peeling process with a cleaning agent, followed by a rinsing process with a specific solvent and a drying process using a spin processor, can prevent stains from forming on the surface of the substrate after drying.

[0009] 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 peeling the semiconductor substrate to which a temporary fixing agent is adhered, 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, to which the temporary fixing agent residue adheres after the peeling process, with a cleaning agent. Step 2: A step of rinsing the semiconductor substrate after step 1, which includes a rinsing process with a solvent that has affinity for both a hydrophobic solvent and water. Step 3: A step of drying the semiconductor substrate after step 2 using a spin processor.

[0010] 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.

[0011] Although the details of the mechanism of action by which the effects of the present disclosure are realized are 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 is thought to 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 thought that the occurrence of stains on the substrate after drying can be prevented by cleaning a substrate to which temporary fixative residue has adhered, 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 interpreted as being limited to this mechanism.

[0012] 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-arsenic substrate (wafer), a gallium-phosphorus substrate (wafer), a gallium-arsenic-aluminum substrate (wafer), etc. In one or more embodiments, the semiconductor substrate may be a substrate (wafer) having pads and / or lands that are portions for bonding and mounting.

[0013] 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). Examples of the shape of the temporary fixing agent (adhesive) include a film. Examples of film-shaped temporary fixing agents include an adhesive sheet, an adhesive film, and an adhesive tape. Examples of the thickness of the temporary fixing agent (adhesive) include 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 a 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, and more specifically, refers to a residue derived from the temporary fixing agent (adhesive) remaining on a 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.

[0014] [Peeling Treatment Step] The semiconductor substrate manufacturing method of the present disclosure includes a step (hereinafter also referred to as a "peeling treatment step") of peeling a semiconductor substrate to which a temporary fixing agent has been adhered, to remove the temporary fixing agent, prior to the cleaning step (step 1) described below. Examples of peeling treatment 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 has been adhered, to remove 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.

[0015] [Step 1: Cleaning] Step 1 in the semiconductor substrate manufacturing method of the present disclosure is a step of cleaning a semiconductor substrate (hereinafter also referred to as a "cleaning step") to which a temporary fixing agent residue adheres after a peeling treatment (hereinafter also referred to as a "cleaning object") with a cleaning agent. In one or more embodiments, the cleaning step is a step of removing the temporary fixing agent residue remaining on the semiconductor substrate after the peeling treatment with a cleaning agent. 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 adhered after 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.

[0016] 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, a cleaning agent temperature of preferably 40°C or higher and 70°C or lower, and a immersion time of preferably 1 minute or higher and 60 minutes or lower. Ultrasonic vibrations may be applied to the cleaning agent, and examples of ultrasonic vibration conditions include 25 to 50 kHz or 35 to 45 kHz. Spin cleaning can also be used.

[0017] (Cleaning Agent) Examples of the cleaning agent used in step 1 include conventionally known cleaning agents. For example, cleaning agents containing at least one selected from an organic solvent and an amine are included. In one or more embodiments, the cleaning agent used in step 1 contains an organic solvent, and in one or more embodiments, it contains an amine. Examples of organic solvents 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.

[0018] <Glycol Ether> Examples of glycol ethers include those containing 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. R-O-(AO) ｎ-H (I) In the above formula (I), R represents a hydrocarbon group having from 1 to 6 carbon atoms, AO represents an ethyleneoxy group (EO) or a propyleneoxy group (PO), and n represents the number of moles of AO added, which is a number of from 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 from 1 to 6 carbon atoms, more preferably an alkyl group having from 1 to 6 carbon atoms, and even more preferably an alkyl group having from 1 to 4 carbon atoms. From the same viewpoint, AO is preferably an ethyleneoxy group (EO). From the same viewpoint, n is preferably from 1 to 3. Examples of the compound represented by the above formula (I) include monophenyl ethers such as ethylene glycol monophenyl ether, diethylene glycol monophenyl ether, and triethylene glycol monophenyl ether; monoalkyl ethers having an alkyl group having from 1 to 6 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 adhesive removability, the compound represented by formula (I) is 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 having from 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 greater than 10% by mass. From the viewpoint of improving adhesive removability, the glycol ether is preferably a diethylene glycol monoalkyl ether having an alkyl group having from 1 to 6 carbon atoms, and more preferably diethylene glycol monobutyl ether (BDG).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.

[0019] <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 a single 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 adhesive removability, the number of carbon atoms in the hydrocarbon is preferably 5 or more, more preferably 6 or more, and from the same viewpoint, 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, from the same viewpoint, 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. When the hydrocarbon is an aromatic hydrocarbon, from the same viewpoint, the number of carbon atoms in the aromatic hydrocarbon is preferably 5 or more, more preferably 6 or more, and even more preferably 7 or more, and preferably 14 or less, more preferably 12 or less, 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 content of hydrocarbons 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 content of hydrocarbons in the cleaning agent is preferably 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 content of hydrocarbons refers to the total content of those hydrocarbons.

[0020] <Amine> Examples of amines include alkanolamines (amino alcohols). Examples of 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. 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. 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. ３is preferably a hydrogen atom from the same viewpoint. 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. From the viewpoint of improving adhesive removability, the content of the amine 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 viewpoints of improving adhesive removability, preventing damage to components, and reducing the nitrogen content, the content 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 to 50% by mass, 5% by mass to 45% by mass, or 8% by mass to 40% by mass. When two or more amines are used in combination, the amine content refers to the total content of the amines.

[0021] <Mass Ratio (Amine / Glycol Ether)> From the viewpoint of improving adhesive removability, the mass ratio of amine to glycol ether (amine / glycol ether) in the cleaning agent is preferably 0.01 or more, more preferably 0.05 or more, even more preferably 0.1 or more, and from the same viewpoint, it is preferably 10 or less, more preferably 5 or less, and even more preferably 2 or less. <Mass Ratio (Amine / Hydrocarbon)> From the viewpoint of improving adhesive removability, the mass ratio of amine to hydrocarbon (amine / hydrocarbon) in the pre-cleaning agent is preferably 0.01 or more, more preferably 0.05 or more, and even more preferably 0.1 or more, and from the same viewpoint, it is preferably 10 or less, more preferably 5 or less, and even more preferably 1 or less. <Mass Ratio (Glycol Ether / Hydrocarbon)> From the viewpoint of improving adhesive removability, 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, and from the same viewpoint, it is preferably 10 or less, more preferably 5 or less, and even more preferably 1 or less.

[0022] <Other Components> In one or more embodiments, the cleaning agent may further contain water and other components as needed. Examples of 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, polymer compounds, solubilizers, antioxidants, preservatives, antifoaming agents, and antibacterial agents.

[0023] In the present disclosure, the "content of each component in the cleaning agent" refers to the content of each component at the time of cleaning, i.e., at the time when the cleaning agent starts 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, as needed, the above-mentioned optional components (water and other components) using a known method.

[0024] [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 a "rinse step"), and includes rinsing with a solvent (rinse liquid) that has affinity for both a hydrophobic solvent and water.

[0025] 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 (rinse 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 higher, more preferably 10 seconds or higher, and even more preferably 15 seconds or higher from the viewpoint of suppressing stain formation, and is preferably 300 seconds or lower, more preferably 120 seconds or lower, and even more preferably 60 seconds or lower from the viewpoint of productivity. Here, the rinse time refers to the time during which the rinse liquid is supplied.

[0026] In one or more embodiments, step 2 may further include rinsing the semiconductor substrate with water (rinse liquid) after the rinsing treatment 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 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 water rinse time 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.

[0027] The method of the rinsing treatment in step 2 is not particularly limited, and can be a method commonly used for cleaning substrates in semiconductor substrate manufacturing processes. Examples include a method of immersing the substrate in a rinsing solution, a method of pouring the rinsing solution over the substrate, and a method of supplying the rinsing solution to the substrate while spinning the substrate. Among these, a method of supplying the rinsing solution while spinning the substrate is preferred. An example of a method of supplying the rinsing solution while spinning the substrate is to use 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 to perform at least one of the rinsing treatments using a spin processor. Therefore, in one or more embodiments of step 2, the rinsing treatment with a solvent that has affinity for both the hydrophobic solvent and water is performed using a spin processor. In one or more other embodiments of 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 stain formation, 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.

[0028] [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 the "drying step").

[0029] 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 the occurrence of stains, 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 more, more preferably 15°C or more, and even more preferably 20°C or more from the viewpoint of productivity, and is preferably 100°C or less, more preferably 80°C or less, and even more preferably 60°C or less from the viewpoint of safety. The drying method in step 3 is spin drying using a spin processor, and preferred examples include spin drying under blowing of an inert gas (such as nitrogen gas).

[0030] 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 stain formation, 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.

[0031] 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 [the rotation speed of step 3 / the rotation speed of step 2] is preferably 1 or greater, more preferably 2 or greater, and even more preferably 3 or greater, 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 [the rotation speed of step 3 / the rotation speed of step 2] is preferably 1 or greater and 10 or less, more preferably 2 or greater and 9 or less, and even more preferably 3 or greater and 8 or less.

[0032] 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 step of bonding the substrate to a fixing member with a temporary fixing agent (adhesive), (b) a polishing step of polishing the backside of the bonding surface of the substrate to the fixing member, (c) a processing step of processing the polished surface of the substrate, and (d) a separation step of separating the processed substrate from the fixing member. Each of the above steps is described below.

[0033] <Step (a): Adhesion Step> 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 a step (a1) of applying the temporary fixing agent (adhesive) to the surface of the substrate or the fixing member to form a temporary fixing agent layer (adhesive layer), and a 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.

[0034] Examples of the substrate used in step (a) include 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. Examples of the fixing member used in step (a) include, but are not limited to, a silicon substrate (wafer) or a glass plate having a diameter of 100 to 500 mm and a thickness of 500 to 20000 μm.

[0035] 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 and processing steps, and allows the substrate to be easily separated from the fixing member in the separation step. Examples of such temporary fixing agents (adhesives) include those used in the manufacturing process of 3DICs. Examples of temporary fixing agents (adhesives) used in the manufacturing process of 3DICs include polyimide-based, polysiloxane-based, acrylic-based, or methacrylic-based adhesives (adhesive compositions). Specifically, examples include the adhesive compositions described in JP 2021-161196 A. In one or more embodiments, the temporary fixing agent (adhesive) used in step (a) may include those containing polysiloxane, acrylic ester, or methacrylic 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, etc.

[0036] In the step (a1), the method for applying the temporary fixing agent (adhesive) is not particularly limited, but examples thereof include spin coating, etc. The film thickness of the applied layer of the temporary fixing agent (adhesive) (temporary fixing agent layer, adhesive layer) is, for example, 5 to 500 μm.

[0037] In step (a2), the temperature of the heat treatment is, for example, 80°C or higher, and is preferably 150°C or lower from the viewpoint of preventing excessive curing of the adhesive. The time of the heat treatment is, for example, 30 seconds or longer, and is preferably 10 minutes or shorter from the viewpoint of preventing deterioration of the temporary fixing agent layer (adhesive layer) and other members. Heating can be performed using a hot plate, an oven, or the like. The film thickness of the temporary fixing agent layer (adhesive layer) after the heat treatment can be, for example, 5 μm or more and 500 μm or less.

[0038] <Step (b): Polishing Step> Step (b) is a polishing step in which the back surface of the substrate opposite to the adhesive surface to be bonded to the fixing member (the surface opposite to the adhesive surface) is polished. 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, and examples thereof include 50 μm to 200 μm.

[0039] <Step (c): Processing Step> 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, examples of step (c) include an electrode formation step, a metal wiring formation step, a protective film formation step, and the like. Examples 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 performed at a high temperature of 150°C or higher. When forming electrodes such as TSVs, a heat treatment at, for example, 250°C to 350°C may be performed. 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 to 500 μm.

[0040] <Step (d): Separation Step> Step (d) is a step (separation step) of separating the processed substrate and 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 has been separated.

[0041] [Item to be Cleaned] Examples of items to be cleaned include semiconductor substrates to which temporary fixing agent (adhesive) residues have adhered after peeling. Examples of semiconductor substrates include substrates (wafers) such as silicon substrates (wafers), silicon carbide substrates (wafers), germanium substrates (wafers), gallium nitride substrates (wafers), gallium-arsenic substrates (wafers), gallium-phosphorus substrates (wafers), and gallium-arsenic-aluminum substrates (wafers). In one or more embodiments, examples of the substrate (wafer) include substrates (wafers) 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 semiconductor substrates to which temporary fixing agent (adhesive) residues have adhered after peeling include a substrate to which a temporary fixing agent (adhesive) has been adhered and then subjected to peeling, a substrate to which a substrate temporarily fixed (adhered) to a fixing member with a temporary fixing agent (adhesive) has been separated from the fixing member and then subjected to peeling, and the like. In one or more embodiments, the substrate after separation from the fixing member and peeling treatment may be a substrate (wafer) having metal pads to which temporary fixing agent (adhesive) residues have adhered. In one or more embodiments, the semiconductor substrate after peeling treatment may be a semiconductor substrate used in the manufacturing process of three-dimensional integrated circuits (3DIC) to which temporary fixing agent (adhesive) residues have adhered after peeling treatment. In one or more embodiments, the semiconductor substrate after peeling treatment to which temporary fixing agent (adhesive) residues have adhered has undergone 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.

[0042] [Finishing Treatment 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) to which temporary fixing agent residue has adhered after a peeling treatment is cleaned with a cleaning agent, and then finished. Examples of objects to be cleaned in the finishing treatment method of the present disclosure include the objects to be cleaned 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 treatment method of the present disclosure includes a step of rinsing the semiconductor substrate after the cleaning treatment, which includes a step (rinsing step) of rinsing with a solvent that has affinity for both a hydrophobic solvent and water, and a step (drying step) of drying the semiconductor substrate after the rinsing treatment using a spin processor. In one or more embodiments, the rinsing treatment in the rinsing step of the finishing treatment method of the present disclosure can 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 treatment method of the present disclosure may be the same as the drying method in step 3 of the semiconductor substrate production method of the present disclosure described above. The temporary fixing agent may be the temporary fixing agent in the semiconductor substrate production method of the present disclosure described above.

[0043] The present disclosure further relates to one or more of the following embodiments: <1> A method for manufacturing a semiconductor substrate, including the following steps 1, 2, and 3, further including, before step 1, a step of peeling the semiconductor substrate to which a temporary fixing agent is adhered, to remove the temporary fixing agent. Step 1: A step of cleaning the semiconductor substrate, to which a 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, which includes a rinsing treatment with a solvent having an affinity for both a hydrophobic solvent and water. Step 3: A step of drying the semiconductor substrate after step 2, using a spin processor. <2> The manufacturing method according to <1>, wherein the solvent having an affinity for both a hydrophobic solvent and water, used in step 2, is alcohol. <3> The manufacturing method according to <1> or <2>, wherein the rotation speed of the spin processor used in step 3 is 300 rpm or more and 3000 rpm or less, or 600 rpm or more and 2500 rpm or less, or 1000 rpm or more and 2000 rpm or less. <4> The manufacturing method according to any of <1> to <3>, wherein the temporary fixing agent is in a film form. <5> The manufacturing method according to any of <1> to <4>, wherein the thickness of the temporary fixing agent is 5 μm or more and 500 μm or less. <6> The manufacturing method according to any of <1> to <5>, wherein the thickness of the temporary fixing agent is 10 μm or more and 100 μm or less. <7> The manufacturing method according to any of <1> to <6>, wherein the cleaning agent used in step 1 contains an organic solvent. <8> The manufacturing method according to any of <1> to <7>, wherein the cleaning agent used in step 1 contains a glycol ether. <9> The production method according to <8>, wherein the content of glycol ether in the cleaning agent used in step 1 is 10% by mass or more and 65% by mass or less, or 15% by mass or more and 60% by mass or less. <10> The production method according to any one of <1> to <9>, wherein the cleaning agent used in step 1 contains a hydrocarbon. <11> The production method according to <10>, wherein the hydrocarbon is at least one selected from toluene, ethylbenzene, xylene, and mesitylene. <12> The production method according to <10> or <11>, wherein the hydrocarbon has 5 or more or 6 or more carbon atoms and 14 or less, 12 or less, 10 or less, or 9 or less carbon atoms.<13> The production method according to any one of <10> to <12>, wherein the content of hydrocarbons in the cleaning agent used in step 1 is 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. <14> The production method according to any one of <1> to <13>, wherein the cleaning agent used in step 1 contains an amine. <15> The production method according to any one of <1> to <14>, wherein the cleaning agent used in step 1 contains a compound represented by the following formula (II): 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 ３represents a methyl group or a hydrogen atom. <16> The production method according to <14> or <15>, wherein the content of amine in the cleaning agent used in step 1 is 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. <17> The production method according to any of <14> to <16>, wherein the mass ratio of amine to glycol ether (amine / glycol ether) in the cleaning agent used in step 1 is 0.01 or more, or 0.05 or more, or 0.1 or more, and 10 or less, or 5 or less, or 2 or less. <18> The production method according to any of <14> to <17>, wherein the mass ratio of amine to hydrocarbon (amine / hydrocarbon) in the cleaning agent used in step 1 is 0.01 or more, or 0.05 or more, or 0.1 or more, and 10 or less, or 5 or less, or 1 or less. <19> The manufacturing method according to any one of <7> to <18>, wherein the mass ratio of glycol ether to hydrocarbon (glycol ether / hydrocarbon) in the pre-cleaning agent used in step 1 is 0.01 or more, or 0.1 or more, or 0.2 or more, and 10 or less, or 5 or less, or 1 or less. <20> The manufacturing method according to any one of <1> to <19>, wherein in step 2, the rinsing treatment with the solvent having an affinity for both the hydrophobic solvent and water is performed using a spin processor. <21> The manufacturing method according to any one of <1> to <20>, wherein in step 2, the semiconductor substrate after the rinsing treatment with the solvent having an affinity for both the hydrophobic solvent and water is performed with water. <22> The manufacturing method according to any one of <1> to <21>, wherein in step 2, the rinsing treatment with water is performed using a spin processor. <23> The manufacturing method according to any one of <1> to <22>, wherein the rotation speed of the spin processor used in step 2 is 50 rpm or more and 3000 rpm or less, or 75 rpm or more and 2500 rpm or less, or 100 rpm or more and 2000 rpm or less. <24> The manufacturing method according to any one of <1> to <23>, wherein the rotation speed of the spin processor used in step 3 is equal to or higher than the rotation speed of the spin processor used in step 2.<25> The manufacturing method according to any one of <1> to <24>, 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, or 2 or more and 9 or less, or 3 or more and 8 or less.

[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 Detergents The components shown in Table 1 were blended in the amounts (% by mass, active ingredient) shown in Table 1, and the mixture was stirred and mixed to prepare detergents.

[0046] The following substances were used to prepare the cleaning agent: MEA: monoethanolamine [manufactured by Nippon Shokubai Co., Ltd.] BDG: butyl diglycol [manufactured by Nippon Nyukazai Co., Ltd., diethylene glycol monobutyl ether] Ethylbenzene [manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.]

[0047]

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

[0049]

[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.

[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, further comprising, 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 a rinsing treatment with a solvent having an affinity for both a hydrophobic solvent and water. Step 3: A step of 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. The manufacturing method according to claim 1 or 2, wherein the rotation speed of the spin processor used in step 3 is 300 rpm or more and 3000 rpm or less.

4. A manufacturing method according to any one of claims 1 to 3, wherein the temporary fixing agent is in the form of a film.

5. A manufacturing method according to any one of claims 1 to 4, wherein the thickness of the temporary fixing agent is 5 μm or more and 500 μm or less.

6. A manufacturing method according to any one of claims 1 to 5, wherein the thickness of the temporary fixing agent is 10 μm or more and 100 μm or less.

7. The manufacturing method according to any one of claims 1 to 6, wherein the cleaning agent used in step 1 contains an organic solvent.

8. The method of any one of claims 1 to 7, wherein the cleaning agent used in step 1 contains an amine.

9. A manufacturing method according to any one of claims 1 to 8, wherein in step 2, a rinsing treatment with a solvent having an affinity for both the hydrophobic solvent and water is carried out using a spin processor.

10. A manufacturing method according to any one of claims 1 to 9, wherein step 2 further comprises rinsing the semiconductor substrate with water after rinsing 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 carried out using a spin processor.

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

13. The manufacturing method according to any one of claims 9 to 12, 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. A manufacturing method according to any one of claims 9 to 13, wherein the spin ratio between the rotational speed of the spin processor used in step 3 and the rotational speed of the spin processor used in step 2 [rotational speed in step 3 / rotational speed in step 2] is 1 or more and 10 or less.

Images