Method for manufacturing semiconductor wafer

Abstract

Provided is a method for manufacturing a semiconductor wafer, the method making it possible to obtain a semiconductor wafer that has no resin residue at a substrate end part or reverse surface.　This method for manufacturing a semiconductor wafer comprises: a step 1 for forming a polyimide-resin-precursor-containing layer or a polyimide-resin-containing layer on a support base material; and a step 2 for cleaning an end part region of the support base material by using a rinse liquid that contains a ketone-based organic solvent (R1) and an alcohol-based organic solvent (R2). Additionally, this semiconductor wafer is manufactured through the aforementioned method.

Description

Semiconductor wafer manufacturing method

[0001] This invention relates to a method for manufacturing semiconductor wafers.

[0002] Resin materials are widely used as surface protective films, insulating films, and planarization films for semiconductor devices. Among these, polyimide resins are being considered for various applications due to their excellent mechanical properties, heat resistance, and insulating properties. A common method for forming the aforementioned resin films used in semiconductor devices is to spin-coat a resin varnish onto a semiconductor device substrate such as a silicon wafer to form a uniform coating film. After that, the substrate is transported to a hot plate or oven to remove the solvent in the varnish. However, during this spin-coating process, the varnish can spread to the edges and back of the substrate, leading to problems such as contamination of the equipment during substrate transport and dust generation due to film defects. To prevent this, edge rinsing and back rinsing processes are performed, in which a rinse liquid, which is a solvent, is discharged to remove the resin from the edges and back of the substrate. For example, Patent Document 1 discloses a resin film formation method that involves repeatedly performing an edge rinsing process, including a spin-drying process in which the discharge of the rinse liquid is stopped and the substrate is rotated, as a method for effectively removing the resin composition from the edges of the substrate.

[0003] Japanese Patent Publication No. 2008-103660

[0004] The resin film formed on a semiconductor device requires a certain thickness to fill in any steps, but if the varnish coating thickness after spin coating becomes too thick, removal by rinsing solution may be insufficient. In particular, resins with low solubility, such as polyimide resins and polyimide resin precursors, are easily affected by the varnish coating thickness, and there has been a need for a method that can effectively remove resin from the edges and back surface of the substrate even when using these polyimide resins. The present invention has been made in view of this situation, and the object of the present invention is to provide a method for manufacturing a semiconductor wafer that can obtain a semiconductor wafer free of resin residue on the edges and back surface of the substrate.

[0005] The present inventors have found that the above problems can be solved by forming a polyimide resin precursor-containing layer or a polyimide resin-containing layer on a support substrate and washing it with a rinsing solution containing two specific organic solvents, and have completed the invention.

[0006] In other words, the present invention relates to the following [1] to [9]. [1] A method for manufacturing a semiconductor wafer, comprising step 1 of forming a polyimide resin precursor-containing layer or a polyimide resin-containing layer on a support substrate, and step 2 of cleaning the edge region of the support substrate with a rinsing solution containing a ketone-based organic solvent (R1) and an alcohol-based organic solvent (R2). [2] The method for manufacturing a semiconductor wafer according to [1], further comprising step 3 of heating and drying after step 2 to convert the polyimide resin-containing layer or polyimide resin precursor-containing layer into a polyimide resin layer, wherein the thickness of the polyimide resin layer is 3 μm or more. [3] The method for manufacturing a semiconductor wafer according to [1] or [2], wherein the ketone-based organic solvent (R1) is at least one selected from the group consisting of acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, and methyl isobutyl ketone, and the alcohol-based organic solvent (R2) is at least one selected from the group consisting of isopropyl alcohol, methanol, ethanol, and 1-methoxy-2-propanol. [4] The method for manufacturing a semiconductor wafer according to any one of [1] to [3], wherein the volume ratio [(R1) / (R2)] of the ketone organic solvent (R1) and the alcohol organic solvent (R2) in the rinse solution is 50 / 50 to 95 / 5. [5] The method for manufacturing a semiconductor wafer according to any one of [1] to [4], wherein the polyimide resin precursor-containing layer contains a polyimide resin precursor, the polyimide resin-containing layer contains a polyimide resin, and the polyimide resin precursor and the polyimide resin have a constituent unit A derived from a tetracarboxylic dianhydride and a constituent unit B derived from a diamine, wherein the constituent unit A includes a constituent unit (A1) which is at least one selected from the group consisting of a constituent unit (A11) derived from a compound represented by the following formula (a11) and a constituent unit (A12) derived from a compound represented by the following formula (a12), and the constituent unit B includes a constituent unit (B1) derived from a compound represented by the following formula (b1). (In formula (a11), X is a single bond, an ether group, a carbonyl group, a sulfone group, an ester group, an amide group, a sulfide group, a phenylene group, an oxyphenyl ether group, a bisphenoxyfluorene group, an isopropylidene group, a hexafluoroisopropylidene group, or a fluorenylidene group. In formula (a12), Y １ and Y ２ Each of these is a single bond, an ether group, a carbonyl group, a sulfone group, an ester group, an amide group, a sulfide group, a phenylene group, an oxyphenyl ether group, a bisphenoxyfluorene group, a hexafluoroisopropylidene group, an isopropylidene group, or a fluorenylidene group. In formula (b1), Z is a single bond, an ether group, a carbonyl group, a sulfone group, an ester group, an amide group, a sulfide group, a phenylene group, an oxyphenyl ether group, a bisphenoxyfluorene group, an isopropylidene group, a hexafluoroisopropylidene group, or a fluorenylidene group.) [6] The method for manufacturing a semiconductor wafer according to [5], wherein the constituent unit (A11) includes a constituent unit (A111) derived from a compound represented by the following formula (a111). [7] The method for manufacturing a semiconductor wafer according to [5] or [6], wherein the constituent unit (B1) includes a constituent unit (B11) derived from a compound represented by the following formula (b11). [8] A method for manufacturing a semiconductor wafer according to any one of [5] to [7], wherein the constituent unit A further comprises at least one selected from the group consisting of a constituent unit (A2) derived from a compound represented by the following formula (a2), a constituent unit (A3) derived from a compound represented by the following formula (a3), and a constituent unit (A4) derived from a compound represented by the following formula (a4). (In formula (a3), n is 1 or 2.) [9] A semiconductor wafer manufactured by any one of the methods described in [1] to [8] above.

[0007] This invention provides a method for manufacturing semiconductor wafers that can produce semiconductor wafers free of resin residue on the substrate edges and back surface. The semiconductor wafer manufacturing method of the present invention is useful as a method for manufacturing semiconductor wafers having a surface protective film, an insulating film, and a planarization film.

[0008] [Method for Manufacturing Semiconductor Wafers] The present invention provides a method for manufacturing semiconductor wafers, comprising: step 1 forming a polyimide resin precursor-containing layer or a polyimide resin-containing layer on a support substrate; and step 2 cleaning the edge regions of the support substrate with a rinsing solution containing a ketone-based organic solvent (R1) and an alcohol-based organic solvent (R2). The manufacturing method of the present invention, having the above configuration, can produce semiconductor wafers free of resin residue on the substrate edges and back surface. The reason for this effect is not entirely clear, but it is thought to be as follows: In the manufacturing method of the present invention, a polyimide resin precursor-containing layer or a polyimide resin-containing layer is formed on a support substrate. It is thought that the amino group structure of the polyimide resin precursor and polyimide resin contained in these layers reacts with the carbonyl group of the ketone-based organic solvent, causing the resin to be altered. It is thought that this altered resin has high solubility in the alcohol-based organic solvent, which allows for particularly effective cleaning of the resin on the substrate edges and back surface. Therefore, it is thought that the manufacturing method of the present invention can produce semiconductor wafers free of resin residue on the substrate edges and back surface.

[0009] [Step 1: Step to form a polyimide resin precursor-containing layer or a polyimide resin-containing layer] Step 1 is the step of forming a polyimide resin precursor-containing layer or a polyimide resin-containing layer on a support substrate.

[0010] <Support Substrate> The support substrate is preferably silicon, silicon carbide, gallium nitride, gallium oxide, aluminum nitride, or diamond, and more preferably silicon. The support substrate being silicon provides excellent film-forming properties and heat resistance. Furthermore, silicon is excellent as a support substrate in the present invention because it offers excellent yield in the crystal formation process and is readily available as a raw material.

[0011] The support substrate may be a substrate on which a silicon oxide layer, a silicon nitride layer, and an interlayer insulating layer (Low-k film) are formed, and if the support substrate is a silicon substrate, it may be a silicon substrate on which an interlayer insulating layer (Low-k film) is formed.

[0012] <Polyimide Resin Precursor-Containing Layer or Polyimide Resin-Containing Layer> The polyimide resin precursor-containing layer or polyimide resin-containing layer formed on the support substrate contains a polyimide resin precursor or polyimide resin, and usually contains a solvent (S3). In other words, the polyimide resin precursor-containing layer or polyimide resin-containing layer preferably contains a polyimide resin precursor or polyimide resin and a solvent (S3). The polyimide resin precursor-containing layer or polyimide resin-containing layer may be formed by any method, but preferably it is obtained by applying a varnish containing a polyimide resin precursor and a solvent, or a varnish containing a polyimide resin and a solvent, onto the support substrate. Therefore, the solvent (S3) is a solvent contained in the varnish. Next, the polyimide resin precursor contained in the polyimide resin precursor-containing layer, the polyimide resin contained in the polyimide resin-containing layer, and the solvent (S3) will be described.

[0013] <Polyimide resin precursor and polyimide resin> The polyimide resin precursor preferably has a polyamic acid structure in which some or all of the imide bonds of the polyimide resin are amide bonds and carboxyl groups, and more preferably is a polyamic acid.

[0014] When a polyimide resin precursor-containing layer is formed on a support substrate, the polyimide resin precursor-containing layer contains a polyimide resin precursor, the polyimide resin precursor preferably has constituent units A derived from a tetracarboxylic dianhydride and constituent units B derived from a diamine, wherein constituent unit A includes constituent unit (A1) which is at least one selected from the group consisting of constituent units (A11) derived from a compound represented by the following formula (a11) and constituent units (A12) derived from a compound represented by the following formula (a12), and constituent unit B includes constituent unit (B1) derived from a compound represented by the following formula (b1). Furthermore, when a polyimide resin-containing layer is formed on a support substrate, the polyimide resin-containing layer contains a polyimide resin, which preferably has constituent units A derived from tetracarboxylic dianhydride and constituent units B derived from diamine, wherein constituent unit A includes a constituent unit (A1) selected from the group consisting of constituent units (A11) derived from a compound represented by the following formula (a11) and constituent units (A12) derived from a compound represented by the following formula (a12), and constituent unit B includes a constituent unit (B1) derived from a compound represented by the following formula (b1).

[0015] Accordingly, the semiconductor wafer manufacturing method of the present invention preferably comprises a polyimide resin precursor-containing layer containing a polyimide resin precursor, a polyimide resin-containing layer containing a polyimide resin, and the polyimide resin precursor and the polyimide resin having a constituent unit A derived from a tetracarboxylic dianhydride and a constituent unit B derived from a diamine, wherein constituent unit A includes a constituent unit (A1) selected from the group consisting of a constituent unit (A11) derived from a compound represented by the following formula (a11) and a constituent unit (A12) derived from a compound represented by the following formula (a12), and constituent unit B includes a constituent unit (B1) derived from a compound represented by the following formula (b1). (In formula (a11), X is a single bond, an ether group, a carbonyl group, a sulfone group, an ester group, an amide group, a sulfide group, a phenylene group, an oxyphenyl ether group, a bisphenoxyfluorene group, an isopropylidene group, a hexafluoroisopropylidene group, or a fluorenylidene group. In formula (a12), Y １ and Y２ Each of these is a single bond, an ether group, a carbonyl group, a sulfone group, an ester group, an amide group, a sulfide group, a phenylene group, an oxyphenyl ether group, a bisphenoxyfluorene group, a hexafluoroisopropylidene group, an isopropylidene group, or a fluorenylidene group. In formula (b1), Z is a single bond, an ether group, a carbonyl group, a sulfone group, an ester group, an amide group, a sulfide group, a phenylene group, an oxyphenyl ether group, a bisphenoxyfluorene group, an isopropylidene group, a hexafluoroisopropylidene group, or a fluorenylidene group.) The structure of the polyimide resin precursor will be described below, but the polyimide resin contained in the polyimide resin-containing layer formed in this process has a similar structure, except that it is an imide structure instead of a polyamic acid structure. Therefore, the polyimide resin precursor will be described below.

[0016] (Polyimide resin precursor) The polyimide resin precursor preferably has a constituent unit A derived from a tetracarboxylic dianhydride and a constituent unit B derived from a diamine, wherein constituent unit A includes a constituent unit (A1) selected from the group consisting of a constituent unit (A11) derived from a compound represented by the following formula (a11) and a constituent unit (A12) derived from a compound represented by the following formula (a12), and constituent unit B includes a constituent unit (B1) derived from a compound represented by the following formula (b1). (In formula (a11), X is a single bond, an ether group, a carbonyl group, a sulfone group, an ester group, an amide group, a sulfide group, a phenylene group, an oxyphenyl ether group, a bisphenoxyfluorene group, an isopropylidene group, a hexafluoroisopropylidene group, or a fluorenylidene group. In formula (a12), Y １ and Y ２Each of these is a single bond, an ether group, a carbonyl group, a sulfone group, an ester group, an amide group, a sulfide group, a phenylene group, an oxyphenyl ether group, a bisphenoxyfluorene group, a hexafluoroisopropylidene group, an isopropylidene group, or a fluorenylidene group. In formula (b1), Z is a single bond, an ether group, a carbonyl group, a sulfone group, an ester group, an amide group, a sulfide group, a phenylene group, an oxyphenyl ether group, a bisphenoxyfluorene group, an isopropylidene group, a hexafluoroisopropylidene group, or a fluorenylidene group.

[0017] (Constituent Unit A) Constituent unit A is a constituent unit derived from tetracarboxylic dianhydride in the polyimide resin precursor. Constituent unit A includes at least one constituent unit (A1) selected from the group consisting of constituent unit (A11) derived from a compound represented by the following formula (a11) and constituent unit (A12) derived from a compound represented by the following formula (a12), and preferably includes constituent unit (A11) derived from a compound represented by the following formula (a11). By including constituent unit (A1) in constituent unit A, the washability with rinsing solution and the heat resistance of the polyimide resin can be improved. (In formula (a11), X is a single bond, an ether group, a carbonyl group, a sulfone group, an ester group, an amide group, a sulfide group, a phenylene group, an oxyphenyl ether group, a bisphenoxyfluorene group, an isopropylidene group, a hexafluoroisopropylidene group, or a fluorenylidene group. In formula (a12), Y １ and Y ２ These are, respectively, a single bond, an ether group, a carbonyl group, a sulfone group, an ester group, an amide group, a sulfide group, a phenylene group, an oxyphenyl ether group, a bisphenoxyfluorene group, a hexafluoroisopropylidene group, an isopropylidene group, or a fluorenylidene group.

[0018] In formula (a11), X is a single bond, an ether group, a carbonyl group, a sulfone group, an ester group, an amide group, a sulfide group, a phenylene group, an oxyphenyl ether group, a bisphenoxyfluorene group, an isopropylidene group, a hexafluoroisopropylidene group, or a fluorenylidene group. Preferably, X is a single bond, an ether group, a carbonyl group, a sulfone group, a sulfide group, a phenylene group, an oxyphenyl ether group, a bisphenoxyfluorene group, or a fluorenylidene group, and more preferably a sulfone group.

[0019] Compounds represented by formula (a11) include 3,3',4,4'-diphenylsulfontetracarboxylic dianhydride (DSDA), 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA), 4,4'-oxydiphthalic anhydride (s-ODPA), 3,4'-oxydiphthalic anhydride (a-ODPA), 3,3',4,4'-biphenyltetracarboxylic dianhydride (s-BPDA), 2,3,3',4'-biphenyltetracarboxylic dianhydride (a-BPDA), 9,9'-bis(3,4-dicarboxyphenyl)fluorene dianhydride (BPAF), and 4,4'-thiodiphthalic acid. Examples include acid anhydrides, 5-[4-(1,3-dioxo-2-benzofuran-5-yl)phenyl]-2-benzofuran-1,3-dione, 5-[3-(1,3-dioxo-2-benzofuran-5-yl)phenyl]-2-benzofuran-1,3-dione, 9,9-bis[4-(3,4-dicarboxyphenoxy)phenyl]fluorendioanhydride (BPF-PA), 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]hexafluoropropane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)-propane dianhydride, hydroquinone diphthalic anhydride (HQDEA), etc. The compound represented by formula (a11) is preferably 3,3',4,4'-diphenylsulfontetracarboxylic dianhydride (DSDA), 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA), 4,4'-oxydiphthalic anhydride (s-ODPA), 3,4'-oxydiphthalic anhydride (a-ODPA), 3,3',4,4'-biphenyltetracarboxylic dianhydride (s-BPDA), 2,3,3',4'-biphenyltetracarboxylic dianhydride (a-BPDA), 9,9' It is at least one selected from the group consisting of -bis(3,4-dicarboxyphenyl)fluorendianhydride (BPAF), 4,4'-thiodiphthalic anhydride, 5-[4-(1,3-dioxo-2-benzofuran-5-yl)phenyl]-2-benzofuran-1,3-dione, 5-[3-(1,3-dioxo-2-benzofuran-5-yl)phenyl]-2-benzofuran-1,3-dione, and 9,9-bis[4-(3,4-dicarboxyphenoxy)phenyl]fluorendiic anhydride (BPF-PA).The constituent units contained in the constituent unit (A11) may be of one kind or two or more kinds.

[0020] Among these, the constituent unit (A11) preferably contains a constituent unit (A111) derived from a compound represented by the following formula (a111), and more preferably is a constituent unit (A111) derived from a compound represented by the following formula (a111). As described above, the constituent unit A preferably contains a constituent unit (A111) derived from a compound represented by the following formula (a111). The compound represented by the formula (a111) is 3,3',4,4'-diphenylsulfone tetracarboxylic dianhydride (DSDA). By the constituent unit A containing the constituent unit (A111), the detergency with the rinse liquid and the heat resistance of the polyimide resin can be further improved.

[0021] In the formula (a12), Y １ is a single bond, an ether group, a carbonyl group, a sulfone group, an ester group, an amide group, a sulfide group, a phenylene group, an oxyphenyl ether group, a bisphenoxyphenylene group, a hexafluoroisopropylidene group, an isopropylidene group, or a fluororenylidene group. In the formula (a12), Y ２ is a single bond, an ether group, a carbonyl group, a sulfone group, an ester group, an amide group, a sulfide group, a phenylene group, an oxyphenyl ether group, a bisphenoxyphenylene group, a hexafluoroisopropylidene group, an isopropylidene group, or a fluororenylidene group. Y １ is preferably an ether group. Y ２ is preferably a hexafluoroisopropylidene group or a fluororenylidene group.

[0022] The compound represented by formula (a12) is preferably at least one selected from the group consisting of 9,9-bis(trifluoromethyl)-9H-xanthene-2,3,6,7-tetracarboxylic dianhydride (6FCDA) and spiro[11H-difluoro[3,4-b:3',4'-i]xanthene-11,9'-[9H]fluorene]-1,3,7,9-tetron (SFDA). The constituent unit (A12) may consist of one or two types of constituent units. By including constituent unit (A12) in constituent unit A, the cleanability with rinsing solution and the heat resistance of the polyimide resin can be further improved.

[0023] The ratio of constituent unit (A1) in constituent unit A is preferably 30 to 100 mol%, more preferably 70 to 100 mol%, even more preferably 90 to 100 mol%, and even more preferably 95 to 100 mol%, and may even be 100 mol%, and constituent unit A may consist only of constituent unit (A1). By having the ratio of constituent unit (A1) within the above range, the cleanability with rinsing solution and the heat resistance of the polyimide resin can be improved.

[0024] Constituent unit A may consist only of constituent unit (A1), or it may include constituent units other than constituent unit (A1). If constituent unit A includes constituent units other than constituent unit (A1), constituent unit A preferably further includes at least one selected from the group consisting of constituent unit (A2) derived from a compound represented by the following formula (a2), constituent unit (A3) derived from a compound represented by the following formula (a3), and constituent unit (A4) derived from a compound represented by the following formula (a4), and more preferably includes constituent unit (A2) derived from a compound represented by the following formula (a2). (In equation (a3), n is either 1 or 2.)

[0025] The compound represented by formula (a2) is pyromellitic anhydride (PMDA). By including constituent unit (A2) in constituent unit A, the heat resistance of the resulting polyimide resin can be particularly enhanced. In formula (a3), n is 1 or 2, but n is preferably 2. Among the compounds represented by formula (a3), the compound where n is 2 is 4,4-bis(1,3-dioxo-1,3-dihydroisobenzofuran-5-ylcarbonyloxy)biphenyl (BP-TME). The compound where n is 1 is p-phenylenebis(trimellitate) dianhydride (TAHQ). By including constituent unit (A3) in constituent unit A, the heat resistance of the resulting polyimide resin can be particularly enhanced. The compound represented by formula (a4) is 2,3,6,7-naphthalenetetracarboxylic acid 2,3:6,7-dianhydride (NTCDA). By including component unit (A4) in component unit A, the heat resistance of the resulting polyimide resin can be particularly enhanced.

[0026] The molar ratio of constituent unit (A1) to the total of constituent units (A2), (A3), and (A4) in constituent unit A [(A1) / ((A2)+(A3)+(A4))] is preferably 30 / 70 to 100 / 0, more preferably 40 / 60 to 100 / 0, even more preferably 50 / 50 to 100 / 0, even more preferably 60 / 40 to 100 / 0, even more preferably 60 / 40 to 90 / 10, and even more preferably 60 / 40 to 80 / 20. When the molar ratio of constituent unit (A1) to the total of constituent units (A2), (A3), and (A4) is 100 / 0, constituent unit A does not contain constituent units (A2), (A3), and (A4).

[0027] The molar ratio [(A1) / (A2)] of constituent units (A1) to constituent units (A2) in constituent unit A is preferably 30 / 70 to 100 / 0, more preferably 40 / 60 to 100 / 0, even more preferably 50 / 50 to 95 / 5, even more preferably 60 / 40 to 90 / 10, even more preferably 65 / 35 to 85 / 15, and even more preferably 70 / 30 to 80 / 20. When the molar ratio of constituent units (A1) to constituent units (A2) is 100 / 0, constituent unit A does not contain constituent unit (A2). By having the constituent units constituting constituent unit A in the above molar ratio, the washability with rinsing solution and the heat resistance of the polyimide resin can be improved, and in particular the heat resistance of the obtained polyimide resin can be enhanced.

[0028] Constituent unit A may include constituent units other than constituent units (A1), (A2), (A3), and (A4). Examples of tetracarboxylic dianhydrides that provide such constituent units are not particularly limited, but include aromatic tetracarboxylic dianhydrides, alicyclic tetracarboxylic dianhydrides, and aliphatic tetracarboxylic dianhydrides, excluding the compound represented by formula (a1), formula (a2), formula (a3), and formula (a4). When constituent unit A includes constituent units other than (A1), (A2), (A3), and (A4), it is preferable that it includes aromatic tetracarboxylic dianhydrides among the tetracarboxylic dianhydrides excluding the compound represented by formula (a1), formula (a2), formula (a3), and formula (a4). Examples of aromatic tetracarboxylic dianhydrides include ethylene glycol bis(trimellitate) dianhydride (TMEG), 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propanoic acid dianhydride (BPADA), 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]hexafluoropropanoic acid dianhydride (6F-BPADA), 2,2-bis(4-hydroxyphenyl)propane-benzoate-3,3',4,4'-tetracarboxylic acid dianhydride (TMBPA), and 2,2',3,3',5,5'-hexamethyl-[1,1'-biphenyl]-4,4'-diylbis(1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylate) (TMBP-TME).Examples of alicyclic tetracarboxylic dianhydrides include cyclohexane-1,2,4,5-tetracarboxylic dianhydride (HPMDA), cyclohexane-1,2,3,4-tetracarboxylic dianhydride, norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5',6,6'-tetracarboxylic dianhydride (CpODA), 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, and 1,2,3,4-cyclop Examples include tetratetracarboxylic acid dianhydride, 1,2,4,5-cyclopentanetetracarboxylic acid dianhydride, 3,3',4,4'-bicyclohexyltetracarboxylic acid dianhydride, 2,2-propyridene-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, oxy-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, bicyclo[2.2.2]octo-7-ene-2,3,5,6-tetracarboxylic acid dianhydride, and bicyclo[4.4.0]decane-2,3,6,7-tetracarboxylic acid dianhydride. Examples of aliphatic tetracarboxylic acid dianhydrides include 1,2,3,4-butanetetracarboxylic acid dianhydride. In this specification, aromatic tetracarboxylic dianhydride means a tetracarboxylic dianhydride containing one or more aromatic rings, alicyclic tetracarboxylic dianhydride means a tetracarboxylic dianhydride containing one or more alicyclic rings but no aromatic rings, and aliphatic tetracarboxylic dianhydride means a tetracarboxylic dianhydride containing neither aromatic nor alicyclic rings. The constituent units optionally included in constituent unit A may be one type or two or more types.

[0029] (Constituent Unit B) Constituent unit B is a constituent unit derived from diamine in the polyimide resin precursor. Constituent unit B preferably includes constituent unit (B1) derived from a compound represented by the following formula (b1). By including constituent unit (B1) in constituent unit B, the washability with rinsing solution and the heat resistance of the polyimide resin can be improved. (In formula (b1), Z is a single bond, an ether group, a carbonyl group, a sulfone group, an ester group, an amide group, a sulfide group, a phenylene group, an oxyphenyl ether group, a bisphenoxyfluorene group, an isopropylidene group, a hexafluoroisopropylidene group, or a fluorenylidene group.)

[0030] In formula (b1), Z is a single bond, an ether group, a carbonyl group, a sulfone group, an ester group, an amide group, a sulfide group, a phenylene group, an oxyphenyl ether group, a bisphenoxyfluorene group, an isopropylidene group, a hexafluoroisopropylidene group, or a fluorenylidene group, preferably an ester group.

[0031] The compounds represented by formula (b1) are preferably 4-aminophenyl-4-aminobenzoate (4-BAAB), 2,2-bis(4-aminophenyl)hexafluoropropane (HFDA), 4,4'-diaminodiphenyl ether (4,4'-ODA), 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone (4,4'-DDS), 3,3'-diaminodiphenyl sulfone (3,3'-DDS), 9,9-bis(4-aminophenyl)fluorene (BAFL), 4,4'-diaminobiphenyl (benzidine), 4,4'-diaminodiphenyl sulfide, and 4,4'-diaminobenzophenone. Examples include 2,2-bis(3-aminophenyl)propane, 2,2-bis(4-aminophenyl)propane, 1,3-bis(3-amino-α,α-dimethylbenzyl)benzene, 1,3-bis(4-amino-α,α-dimethylbenzyl)benzene (BisAM), 1,4-bis(4-amino-α,α-dimethylbenzyl)benzene (BisAP), 1,4-bis(3-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 4,4-diaminobenzanilide, 3,4-diaminobenzanilide, and the like. In particular, the compound represented by formula (b1) is more preferably the compound represented by the following formula (b11), and the constituent unit (B1) more preferably includes a constituent unit (B11) derived from the compound represented by the following formula (b11). The constituent unit (B1) is more preferably a constituent unit (B11) derived from a compound represented by the following formula (b11). As described above, constituent unit B preferably includes a constituent unit (B11) derived from a compound represented by the following formula (b11).

[0032] The compound represented by formula (b11) is 4-aminophenyl-4-aminobenzoate (4-BAAB). By including the constituent unit (B11) in the constituent unit (B11), the cleaning properties with rinsing solution and the heat resistance of the polyimide resin can be further improved.

[0033] The ratio of the structural unit (B1) in the structural unit B is preferably 30 to 100 mol%, more preferably 70 to 100 mol%, still more preferably 90 to 100 mol%, even more preferably 95 to 100 mol%, and may be 100 mol%. The structural unit B may consist only of the structural unit (B1). By the ratio of the structural unit (B1) being within the above range, the detergency with the rinse liquid and the heat resistance of the polyimide resin can be improved.

[0034] Constituent unit B may include constituent units other than constituent unit (B1). Examples of diamines that provide such constituent units are not particularly limited, but include aromatic diamines, alicyclic diamines, and aliphatic diamines, excluding the compound represented by formula (b1). Aromatic diamines include bis(4-aminophenyl) terephthalate (APTP), 1,4-bis(4-aminobenzoyloxy)benzene, 2,2'-bis(trifluoromethyl)-4,4'-diaminodiphenyl ether (6FODA), 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (2,2'-TFMB), 3,3'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, and 2,2'-bis(trifluoromethyl) (L)-5,5'-diaminobiphenyl, 2,2-bis(3-amino-4-methylphenyl)hexafluoropropane, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane (HFBAPP), 4,4'-diaminodiphenylmethane (DDM), 4,4'-diamino-2,2'-dimethylbiphenyl (mTB), 4,4'-diamino-3,3'-dimethylbiphenyl, 5-amino-1,3,3-trimethyl-1-(4-aminophenoxy) (Lu)-Indan(5-TMDM), 6-amino-1,3,3-trimethyl-1-(4-aminophenyl)-Indan(6-TMDM), 4,4'-bis(3-aminophenoxy)biphenyl, 4,4'-bis(4-aminophenoxy)biphenyl (BODA), 1,1-bis[4-(4-aminophenoxy)phenyl]cyclohexane, 2,2-bis[4-(4-aminophenoxy)phenyl]propane (BAPP), bis[4-(3-aminophenoxy) Examples include phenyl ketone, bis[4-(4-aminophenoxy)phenyl]ketone, bis[4-(3-aminophenoxy)phenyl]sulfide, bis[4-(4-aminophenoxy)phenyl]sulfide, bis[4-(3-aminophenoxy)phenyl]ether, bis[4-(4-aminophenoxy)phenyl]ether, bis[4-(3-aminophenoxy)phenyl]sulfone, and bis[4-(4-aminophenoxy)phenyl]sulfone.Examples of alicyclic diamines include 1,3-bis(aminomethyl)cyclohexane (1,3-BAC), 1,4-bis(aminomethyl)cyclohexane, 1,3-cyclohexyldiamine, 1,4-cyclohexyldiamine, isophoronediamine, bis(aminomethyl)norbornane, 4,4'-diaminodicyclohexylmethane, 4,4'-diaminodicyclohexyl ether, and 2,2-bis(4-aminocyclohexyl)propane. Examples of aliphatic diamines include ethylenediamine and hexamethylenediamine. In this specification, aromatic diamine means a diamine containing one or more aromatic rings, alicyclic diamine means a diamine containing one or more alicyclic rings but not aromatic rings, and aliphatic diamine means a diamine that contains neither aromatic nor alicyclic rings. The constituent units other than the constituent unit (B1) optionally included in constituent unit B may be one type or two or more types.

[0035] (Properties of Polyimide Resin Precursor and Polyimide Resin) The number-average molecular weight of the polyimide resin precursor is preferably 5,000 to 500,000 from the viewpoint of the mechanical strength of the resulting polyimide resin. Similarly, the weight-average molecular weight (Mw) of the polyimide resin precursor is preferably 10,000 to 800,000, and more preferably 20,000 to 300,000. The number-average molecular weight of the polyimide resin is preferably 5,000 to 500,000 from the viewpoint of the mechanical strength of the resulting polyimide resin. Similarly, the weight-average molecular weight (Mw) of the polyimide resin is preferably 10,000 to 800,000, and more preferably 20,000 to 300,000. The number-average molecular weight and weight-average molecular weight of the polyimide resin precursor and polyimide resin can be determined from the standard polyethylene glycol (polyethylene oxide) equivalent values ​​obtained by gel filtration chromatography.

[0036] (Method for Producing Polyimide Resin Precursor and Polyimide Resin) The polyimide resin precursor and the polyimide resin may be produced by any method, but it is preferably produced by the following production method. The polyimide resin precursor and the polyimide resin are obtained by reacting a compound (tetracarboxylic acid component) that provides the above-mentioned structural unit A and a compound (diamine component) that provides the above-mentioned structural unit B to obtain a polyimide resin precursor having a polyamic acid structure or a polyimide resin having an imide structure. Preferably, the production method is more specifically a method for obtaining a polyimide resin precursor having a polyamic acid structure by reacting a tetracarboxylic acid component containing a compound that provides the structural unit (A1) (at least one selected from the group consisting of the compound represented by the formula (a11) and the compound represented by the formula (a12)) and a diamine component containing a compound that provides the structural unit (B1) (the compound represented by the formula (b1)).

[0037] The tetracarboxylic acid component used in this production method preferably contains a compound that provides the structural unit (A1), and may contain a tetracarboxylic acid component other than the compound that provides the structural unit (A1) as long as the effects of the present invention are not impaired. The diamine component used in this production method preferably contains a compound that provides the structural unit (B1), and may contain a diamine component other than the compound that provides the structural unit (B1) as long as the effects of the present invention are not impaired. It is preferable that the amount of the diamine component with respect to 1 mol of the tetracarboxylic acid component is 0.9 to 1.1 mol.

[0038] There are no particular restrictions on the method of reacting the tetracarboxylic acid component and the diamine component in this manufacturing method, and known methods can be used. Specific reaction methods include charging the tetracarboxylic acid component, the diamine component, a solvent, and optionally an end-capturing agent into a reactor and stirring at 0 to 120°C, more preferably 5 to 80°C, for 1 to 72 hours. It is more preferable to react at 80°C or below, as this allows for the stable production of a polyimide resin precursor having a polyamic acid structure, since the molecular weight of the polyimide resin precursor does not fluctuate depending on the temperature history during polymerization and the progression of thermal imidation can be suppressed. By the above method, a solution of a polyimide resin precursor having a polyamic acid structure dissolved in a solvent is obtained.

[0039] On the other hand, to obtain polyimide resin and polyimide resin solution, it is preferable to carry out the imidation reaction at a higher temperature, for example, and to remove the water generated during production using a Dean-Stark apparatus or the like. By performing such operations, the degree of polymerization and the imidation rate can be further increased. The temperature of the imidation reaction is preferably 120 to 250°C, and more preferably 160 to 200°C, from the viewpoint of the reaction rate and suppression of gelation, etc. The reaction time is preferably 0.5 to 10 hours after the start of distillation of the generated water.

[0040] The concentration of the polyimide resin precursor or polyimide resin in the resulting solution is preferably 1 to 50% by mass, more preferably 3 to 35% by mass, and even more preferably 5 to 30% by mass. Next, the raw materials used in this manufacturing method will be described.

[0041] (Tetracarboxylic acid component) The tetracarboxylic acid component used as a raw material in this manufacturing method is preferably a tetracarboxylic dianhydride as described in the (Constituent Unit A) section above, and the preferred tetracarboxylic dianhydride is the same as that described in the (Constituent Unit A) section above. The tetracarboxylic dianhydride used as the tetracarboxylic acid component in this manufacturing method may be in any form of dianhydride, tetracarboxylic acid (free acid), or alkyl ester of tetracarboxylic acid, but is preferably a dianhydride. The tetracarboxylic acid component used as a raw material in this manufacturing method preferably includes at least one compound selected from the group consisting of the compound represented by formula (a11) and the compound represented by formula (a12) above (a compound that gives constituent unit (A1)). The total ratio of the compound represented by formula (a11) and the compound represented by formula (a12) in the tetracarboxylic acid component is preferably 30 to 100 mol%, more preferably 70 to 100 mol%, even more preferably 90 to 100 mol%, and even more preferably 95 to 100 mol, and may even be 100 mol%, and the tetracarboxylic acid component may consist only of the compound represented by formula (a11) and the compound represented by formula (a12). By having the total ratio of the compound represented by formula (a11) and the compound represented by formula (a12) within the above range, the washability with rinsing solution and the heat resistance of the polyimide film can be improved.

[0042] The tetracarboxylic acid component may consist only of the compound represented by formula (a11) and the compound represented by formula (a12), or it may include tetracarboxylic acid components other than the compound represented by formula (a11) and the compound represented by formula (a12). Preferably, the tetracarboxylic acid component other than the compound represented by formula (a11) and the compound represented by formula (a12) includes at least one selected from the group consisting of the compound represented by formula (a2), the compound represented by formula (a3), and the compound represented by formula (a4), and more preferably includes the compound represented by formula (a2).

[0043] The molar ratio [((a11) + (a12)) / ((a2) + (a3) ​​+ (a4))] of the total of the compounds represented by formula (a11) and formula (a12) in constituent unit A is preferably 30 / 70 to 100 / 0, more preferably 40 / 60 to 100 / 0, even more preferably 50 / 50 to 100 / 0, even more preferably 60 / 40 to 100 / 0, even more preferably 60 / 40 to 90 / 10, and even more preferably 60 / 40 to 80 / 20. When the molar ratio of the total of the compounds represented by formula (a11) and formula (a12) to the total of the compounds represented by formula (a2), formula (a3), and formula (a4) is 100 / 0, the tetracarboxylic acid component does not contain the compounds represented by formula (a2), formula (a3), and formula (a4).

[0044] The molar ratio [(a11) / (a2)] of the compound represented by formula (a11) to the compound represented by formula (a2) in the tetracarboxylic acid component is preferably 30 / 70 to 100 / 0, more preferably 40 / 60 to 100 / 0, even more preferably 50 / 50 to 95 / 5, even more preferably 60 / 40 to 90 / 10, even more preferably 65 / 35 to 85 / 15, and even more preferably 70 / 30 to 80 / 20. When the molar ratio of the compound represented by formula (a11) to the compound represented by formula (a2) is 100 / 0, the tetracarboxylic acid component does not contain the compound represented by formula (a2). By having each tetracarboxylic acid constituting the tetracarboxylic acid component in the above molar ratio, the heat resistance of the polyimide resin can be improved.

[0045] The tetracarboxylic acid component may include tetracarboxylic acid components other than the compound represented by formula (a11), the compound represented by formula (a12), the compound represented by formula (a2), the compound represented by formula (a3), and the compound represented by formula (a4). Such tetracarboxylic acid components are not particularly limited, but include aromatic tetracarboxylic acid dianhydrides, alicyclic tetracarboxylic acid dianhydrides, and aliphatic tetracarboxylic acid dianhydrides other than the compound represented by formula (a11), the compound represented by formula (a12), the compound represented by formula (a2), the compound represented by formula (a3), and the compound represented by formula (a4). When the tetracarboxylic acid component includes tetracarboxylic acid components other than the compound represented by formula (a11), formula (a12), formula (a2), formula (a3), and formula (a4), it is preferable to include aromatic tetracarboxylic acid dianhydrides among the tetracarboxylic acid dianhydrides excluding the compound represented by formula (a11), formula (a12), formula (a2), formula (a3), and formula (a4). Specific examples of preferred tetracarboxylic acid dianhydrides are the same as those described in the section (Constituent Unit A) above. These tetracarboxylic acid dianhydrides may be used individually or in combination of two or more.

[0046] (Diamine component) The diamine component used as a raw material in this manufacturing method is preferably the diamine described in the (Constituent unit B) section above, and the preferred diamine component is the same as that described in the (Constituent unit (B)) section above. The diamine used as the diamine component in this manufacturing method may be in the form of a diamine or a diisocyanate corresponding to a diamine, but it is preferably a diamine. The diamine component used as a raw material in this manufacturing method includes the compound represented by formula (b1) above (the compound that gives constituent unit (B1)). The ratio of the compound represented by formula (b1) in the diamine component is preferably 30 to 100 mol%, more preferably 70 to 100 mol%, even more preferably 90 to 100 mol%, even more preferably 95 to 100 mol%, and may be 100 mol%, and the diamine component may consist only of the compound represented by formula (b1). By having the ratio of the compound represented by formula (b1) within the above range, the washability with rinsing solution and the heat resistance of the polyimide resin can be improved.

[0047] The diamine component may include diamine components other than the compound represented by formula (b1). Such diamine components are not particularly limited, but include aromatic diamines, alicyclic diamines, and aliphatic diamines other than the compound represented by formula (b1). Specific examples of preferred diamines are the same as those described in the section on (constituent unit B) above. One type of diamine may be used, or two or more types may be used.

[0048] (End-Sealing Agent) In addition to the tetracarboxylic acid component and diamine component mentioned above, an end-sealing agent may also be used in the production of the polyimide resin precursor. Monoamines or dicarboxylic acids are preferred as the end-sealing agent, with monoamines being more preferred. The amount of end-sealing agent to be introduced is preferably 0.0001 to 0.2 moles, more preferably 0.0001 to 0.1 moles, even more preferably 0.001 to 0.06 moles, and even more preferably 0.01 to 0.06 moles per mole of the tetracarboxylic acid component. Examples of monoamine end-captives include methylamine, ethylamine, propylamine, butylamine, benzylamine, 4-methylbenzylamine, 4-ethylbenzylamine, 4-dodecylbenzylamine, 3-methylbenzylamine, 3-ethylbenzylamine, aniline, 3-methylaniline, 4-methylaniline, o-aminophenol (2-aminophenol), m-aminophenol (3-aminophenol), p-aminophenol (4-aminophenol), o-aminobenzoic acid, m-aminobenzoic acid, and p-aminobenzoic acid. Of these, benzylamine, aniline, and p-aminophenol (4-aminophenol) are preferred, and p-aminophenol (4-aminophenol) is more preferred. Dicarboxylic acid end-captives are preferred, and some of them may be ring-closed. Examples include phthalic acid, phthalic anhydride, 4-chlorophthalic acid, tetrafluorophthalic acid, 2,3-benzophenone dicarboxylic acid, 3,4-benzophenone dicarboxylic acid, cyclopentane-1,2-dicarboxylic acid, and 4-cyclohexene-1,2-dicarboxylic acid. Of these, phthalic acid and phthalic anhydride are more preferred.

[0049] (Solvent (Reaction Solvent)) The solvent (reaction solvent) used in the production of the polyimide resin precursor may be any solvent capable of dissolving the resulting polyimide resin precursor, but preferably, the solvent (S3) contained in the varnish described later is used. Using solvent (S3) as the reaction solvent is convenient and preferable because the polyimide resin precursor solution itself after the production of the polyimide resin precursor, or the polyimide resin precursor varnish (polyimide resin varnish when polyimide resin is produced) can be used simply by adding the solvent to adjust the concentration. Therefore, the solvent (reaction solvent) used in this step preferably includes a solvent (S1) with a boiling point of 190 to 250°C and a solvent (S2) with a boiling point of 110 to 160°C in order to better exhibit the effects of the present invention. Note that the boiling point referred to here is the boiling point at 1 atmosphere (0.1 MPa).

[0050] The boiling point of the solvent (S1) is 190 to 250°C, preferably 190 to 240°C, more preferably 200 to 240°C, even more preferably 210 to 235°C, and even more preferably 220 to 230°C.

[0051] The boiling point of solvent (S2) is 110 to 160°C, preferably 110 to 150°C, more preferably 110 to 140°C, even more preferably 110 to 130°C, and even more preferably 115 to 125°C. By having the boiling points of solvent (S1) and solvent (S2) within the above range, the cleaning properties with rinsing solution are improved, and a polyimide resin with superior heat resistance is obtained.

[0052] The solvent (S1) having a boiling point of 190 to 250°C is preferably a solvent that has the aforementioned boiling point and dissolves the polyimide resin precursor. Examples of solvents (S1) include phenolic solvents, etheric solvents, carbonate solvents, amide solvents, lactone solvents, phosphorus-containing amide solvents, sulfur-containing solvents, ketone solvents, and ester solvents, with amide solvents or lactone solvents being preferred, and lactone solvents being more preferred.

[0053] The solvent (S1) is preferably at least one selected from the group consisting of γ-butyrolactone (boiling point 204°C, GBL), 1,3-dimethyl-2-imidazolidinone (boiling point 222°C, DMI), 3-methyl-2-oxazolidone (boiling point 248°C), N-methylpyrrolidone (boiling point 204°C, NMP), γ-valerolactone (boiling point 207°C), and 3-methoxy-N,N-dimethylpropanamide (boiling point 215°C). More preferably, it is at least one selected from the group consisting of γ-butyrolactone, 1,3-dimethyl-2-imidazolidinone, and 3-methyl-2-oxazolidone. Even more preferably, it is at least one selected from the group consisting of γ-butyrolactone and 1,3-dimethyl-2-imidazolidinone, and even more preferably, it is γ-butyrolactone. Furthermore, it is even more preferable to include both γ-butyrolactone and 1,3-dimethyl-2-imidazolidinone.

[0054] The solvent (S2) having a boiling point of 110 to 160°C is preferably a solvent that has the aforementioned boiling point and dissolves the polyimide resin precursor. Examples of solvents (S2) include phenolic solvents, etheric solvents, carbonateic solvents, amide solvents, lactone solvents, phosphorus-containing amide solvents, sulfur-containing solvents, ketone solvents, and ester solvents, with etheric solvents or ketone solvents being preferred, and etheric solvents being more preferred.

[0055] The solvent (S2) is preferably at least one selected from the group consisting of propylene glycol monomethyl ether (boiling point 120°C, PGME), cyclohexanone (boiling point 155.6°C), and cyclopentanone (boiling point 130.6°C), more preferably at least one selected from the group consisting of propylene glycol monomethyl ether, cyclohexanone, and cyclopentanone, and even more preferably propylene glycol monomethyl ether.

[0056] Therefore, preferred combinations of solvent (S1) and solvent (S2) are as follows: Preferably, solvent (S1) is at least one selected from the group consisting of γ-butyrolactone and 1,3-dimethyl-2-imidazolidinone, and solvent (S2) is at least one selected from the group consisting of propylene glycol monomethyl ether, cyclohexanone, and cyclopentanone; more preferably, solvent (S1) is at least one selected from the group consisting of γ-butyrolactone and 1,3-dimethyl-2-imidazolidinone, and solvent (S2) is propylene glycol monomethyl ether. The above combination of solvent (S1) and solvent (S2) results in better cleaning properties with rinsing solution and a polyimide resin with superior heat resistance.

[0057] The solvent (reaction solvent) used in this process may contain solvents other than solvent (S1) and solvent (S2), but it is preferable that it substantially contains no solvents other than solvent (S1) and solvent (S2). The total amount of solvent (S1) and solvent (S2) contained in the solvent (reaction solvent) used in this process is preferably 50% by mass or more, more preferably 70 to 100% by mass, even more preferably 80 to 100% by mass, even more preferably 90 to 100% by mass, even more preferably 95 to 100% by mass, even more preferably 98 to 100% by mass, even more preferably 99 to 100% by mass, and even more preferably 100% by mass, and the solvent (reaction solvent) used in this process may consist only of solvent (S1) and solvent (S2).

[0058] Other solvents besides solvent (S1) and solvent (S2) include phenolic solvents, etheric solvents, carbonateic solvents, amide solvents, lactone solvents, phosphorus-containing amide solvents, sulfur-containing solvents, ketone solvents, and ester solvents, with amide solvents or lactone solvents being preferred, and lactone solvents being more preferred. The above organic solvents may be used individually or in combination of two or more. Solvent (S1) may be used individually or in combination of two or more. Solvent (S2) may be used individually or in combination of two or more.

[0059] <Solvent (S3)> The polyimide resin precursor-containing layer or polyimide resin-containing layer usually contains solvent (S3). The polyimide resin precursor-containing layer or polyimide resin-containing layer is usually subjected to spin-drying after varnish is applied to the support substrate as described below, so the solvent content is less than the solvent content in the varnish, but it contains the solvent that was contained in the varnish. This solvent will be referred to as solvent (S3), and the solvent in the varnish will also be explained in this section. Note that if the varnish contains multiple solvents, it is thought that the solvent content ratio changes after the spin-drying process due to the differences in their boiling points and vapor pressures.

[0060] The solvent (S3) contained in the polyimide resin precursor-containing layer, the polyimide resin-containing layer, and the varnish described later is not limited as long as it can dissolve the resin, resin precursor, and other components contained in the varnish. However, in order to better exhibit the effects of the present invention, the following solvents are preferred. The solvent (S3) preferably includes a solvent (S1) with a boiling point of 190 to 250°C and a solvent (S2) with a boiling point of 110 to 160°C. The boiling point referred to here is the boiling point at 1 atmosphere (0.1 MPa).

[0061] The boiling point of the solvent (S1) is 190 to 250°C, preferably 190 to 240°C, more preferably 200 to 240°C, even more preferably 210 to 235°C, and even more preferably 220 to 230°C.

[0062] The boiling point of solvent (S2) is 110 to 160°C, preferably 110 to 150°C, more preferably 110 to 140°C, even more preferably 110 to 130°C, and even more preferably 115 to 125°C. By having the boiling points of solvent (S1) and solvent (S2) within the above range, a polyimide film with better rinsing properties and superior heat resistance can be obtained.

[0063] The solvent (S1) having a boiling point of 190 to 250°C is preferably a solvent that has the aforementioned boiling point and dissolves the polyimide resin precursor. Examples of solvents (S1) include phenolic solvents, etheric solvents, carbonate solvents, amide solvents, lactone solvents, phosphorus-containing amide solvents, sulfur-containing solvents, ketone solvents, and ester solvents, with amide solvents or lactone solvents being preferred, and lactone solvents being more preferred.

[0064] The solvent (S1) is preferably at least one selected from the group consisting of γ-butyrolactone (boiling point 204°C, GBL), 1,3-dimethyl-2-imidazolidinone (boiling point 222°C, DMI), 3-methyl-2-oxazolidone (boiling point 248°C), N-methylpyrrolidone (boiling point 204°C, NMP), γ-valerolactone (boiling point 207°C), and 3-methoxy-N,N-dimethylpropanamide (boiling point 215°C). More preferably, it is at least one selected from the group consisting of γ-butyrolactone, 1,3-dimethyl-2-imidazolidinone, and 3-methyl-2-oxazolidone. Even more preferably, it is at least one selected from the group consisting of γ-butyrolactone and 1,3-dimethyl-2-imidazolidinone, and even more preferably, it is γ-butyrolactone. Furthermore, it is even more preferable to include both γ-butyrolactone and 1,3-dimethyl-2-imidazolidinone.

[0065] The solvent (S2) having a boiling point of 110 to 160°C is preferably a solvent that has the aforementioned boiling point and dissolves the polyimide resin precursor. Examples of solvents (S2) include phenolic solvents, etheric solvents, carbonateic solvents, amide solvents, lactone solvents, phosphorus-containing amide solvents, sulfur-containing solvents, ketone solvents, and ester solvents, with etheric solvents or ketone solvents being preferred, and etheric solvents being more preferred.

[0066] The solvent (S2) is preferably at least one selected from the group consisting of propylene glycol monomethyl ether (boiling point 120°C, PGME), cyclohexanone (boiling point 155.6°C), and cyclopentanone (boiling point 130.6°C), more preferably at least one selected from the group consisting of propylene glycol monomethyl ether, cyclohexanone, and cyclopentanone, and even more preferably propylene glycol monomethyl ether.

[0067] Therefore, the preferred combinations of solvent (S1) and solvent (S2) are as follows: It is preferable that solvent (S1) is at least one selected from the group consisting of γ-butyrolactone, 1,3-dimethyl-2-imidazolidinone and 3-methyl-2-oxazolidone, and solvent (S2) is at least one selected from the group consisting of propylene glycol monomethyl ether, cyclohexanone and cyclopentanone; it is more preferable that solvent (S1) is at least one selected from the group consisting of γ-butyrolactone and 1,3-dimethyl-2-imidazolidinone, and solvent (S2) is at least one selected from the group consisting of propylene glycol monomethyl ether, cyclohexanone and cyclopentanone; and it is even more preferable that solvent (S1) is at least one selected from the group consisting of γ-butyrolactone and 1,3-dimethyl-2-imidazolidinone (S1), and solvent (S2) is propylene glycol monomethyl ether. The above combination of solvent (S1) and solvent (S2) results in a polyimide resin with better cleaning properties using the rinsing solution and superior heat resistance.

[0068] The mass ratio of the content of solvent (S1) to the content of solvent (S2) in solvent (S3) [(S1) / (S2)] is preferably 30 / 70 to 90 / 10, more preferably 40 / 60 to 80 / 20, even more preferably 50 / 50 to 70 / 30, and even more preferably 50 / 50 to 60 / 40. By having the above mass ratio of the contents of solvent (S1) and solvent (S2), the cleaning properties with rinsing solution are improved, and a polyimide resin with better heat resistance is obtained.

[0069] <Formation of Polyimide Resin Precursor-Containing Layer or Polyimide Resin-Containing Layer> Any method may be used to form the polyimide resin precursor-containing layer or polyimide resin-containing layer on the support substrate, but a method of formation by spin coating is preferred. More specifically, preferably, a uniform coating film of the polyimide resin precursor varnish or polyimide resin varnish described later is formed on the support substrate in a spin coating step, and then the solvent in the varnish is evaporated in a spin drying step to eliminate fluidity and obtain the polyimide resin precursor-containing layer or polyimide resin-containing layer. After the spin drying step, step 2 (rinse cleaning step) described later is performed, but after step 2, the spin coating step and spin drying step may be performed again, and then step 2 may be performed again. In this way, the spin coating step, spin drying step and rinse cleaning step may be repeated two or more times to gradually thicken the polyimide resin precursor-containing layer or polyimide resin-containing layer.

[0070] The rotational speed in the spin coating and spin drying processes may be constant, gradually increased, or decreased. The rotational speed is preferably 200 to 4000 rpm, more preferably 250 to 3000 rpm, and even more preferably 300 to 2000 rpm. The duration of the spin drying process is preferably 1 to 300 seconds, more preferably 5 to 200 seconds, and even more preferably 10 to 100 seconds.

[0071] The conditions for forming the polyimide resin precursor-containing layer or the polyimide resin-containing layer in this process are preferably set considering the final thickness of the polyimide resin layer. In other words, it is preferable to adjust the varnish solid content concentration, varnish viscosity, spin-coating conditions, etc., so that the desired thickness of the polyimide resin layer is achieved. When determining the conditions for this process, the desired thickness of the polyimide resin layer is preferably 3 μm or more, more preferably 5 μm or more, even more preferably 10 μm or more, even more preferably 20 μm or more, and even more preferably 30 μm or more. It is also preferably 250 μm or less, more preferably 200 μm or less, even more preferably 150 μm or less, and even more preferably 100 μm or less. A thickness within the above range allows for practical use as a protective film, insulating film, or planarization film.

[0072] (Polyimide resin precursor varnish and polyimide resin varnish) This step, as described above, preferably involves forming a uniform coating film of polyimide resin precursor varnish or polyimide resin varnish on a support in a spin-coating step, and then evaporating the solvent in the varnish in a spin-drying step to eliminate fluidity and obtain a polyimide resin precursor-containing layer or polyimide resin-containing layer. In this specification, "varnish" means "polyimide resin precursor varnish and / or polyimide resin varnish". The polyimide resin precursor varnish contains the polyimide resin precursor described in the section <Polyimide resin precursor and polyimide resin> and a solvent. The polyimide resin varnish also contains the polyimide resin described in the section <Polyimide resin precursor and polyimide resin> and a solvent. That is, the polyimide resin precursor contained in the polyimide resin precursor varnish used in this step is the same as the polyimide resin precursor described in the section <Polyimide resin precursor and polyimide resin>, and the preferred polyimide resin precursor is also the same. Furthermore, the polyimide resin contained in the polyimide resin varnish used in this process is the same as the polyimide resin described in the section on <Polyimide Resin Precursor and Polyimide Resin>, and the preferred polyimide resin is also the same.

[0073] Specifically, the polyimide resin precursor has a constituent unit A derived from a tetracarboxylic dianhydride and a constituent unit B derived from a diamine, wherein constituent unit A includes a constituent unit (A1) which is at least one selected from the group consisting of a constituent unit (A11) derived from a compound represented by formula (a11) and a constituent unit (A12) derived from a compound represented by formula (a12), and constituent unit B includes a constituent unit (B1) derived from a compound represented by formula (b1). Furthermore, the polyimide resin preferably has a constituent unit A derived from a tetracarboxylic dianhydride and a constituent unit B derived from a diamine, wherein constituent unit A includes a constituent unit (A1) which is at least one selected from the group consisting of a constituent unit (A11) derived from a compound represented by formula (a11) and a constituent unit (A12) derived from a compound represented by formula (a12), and constituent unit B includes a constituent unit (B1) derived from a compound represented by formula (b1).

[0074] Furthermore, the solvent contained in the polyimide resin precursor varnish used in this process is the same as the solvent (S3) described in the section <Solvent (S3)> above, and the preferred solvent is also the same. Specifically, the polyimide resin precursor varnish and the solvent (S3) contained in the polyimide resin varnish are not limited as long as they can dissolve the resin, resin precursor, and other components contained in the varnish, but in order to further exhibit the effects of the present invention, it is preferable to include a solvent (S1) with a boiling point of 190 to 250°C and a solvent (S2) with a boiling point of 110 to 160°C.

[0075] The varnish may contain solvents other than solvent (S1) and solvent (S2), but it is preferable that it substantially contains no solvents other than solvent (S1) and solvent (S2). The total amount of solvent (S1) and solvent (S2) contained in the varnish is preferably 50% by mass or more, more preferably 70 to 100% by mass, even more preferably 80 to 100% by mass, even more preferably 90 to 100% by mass, even more preferably 95 to 100% by mass, even more preferably 98 to 100% by mass, even more preferably 99 to 100% by mass, and even more preferably 100% by mass, and the solvent contained in the varnish may consist only of solvent (S1) and solvent (S2).

[0076] Other solvents besides solvent (S1) and solvent (S2) include phenolic solvents, etheric solvents, carbonateic solvents, amide solvents, lactone solvents, phosphorus-containing amide solvents, sulfur-containing solvents, ketone solvents, and ester solvents, with amide solvents or lactone solvents being preferred, and lactone solvents being more preferred. The above organic solvents may be used individually or in combination of two or more. Solvent (S1) may be used individually or in combination of two or more. Solvent (S2) may be used individually or in combination of two or more.

[0077] The varnish may be the polyimide resin precursor solution or the polyimide resin solution itself after the production of the polyimide resin, or it may be a solution obtained by further mixing a solvent with the polyimide resin precursor solution or polyimide resin solution and diluting it.

[0078] According to the preferred configuration of the varnish, it contains at least two solvents with different boiling points. As a result, the polyimide precursor is dissolved in a stable varnish, and because it contains a solvent with a boiling point of 110 to 160°C, the solvent evaporates during the spin-drying process performed between the spin-coating and rinsing processes, reducing the fluidity of the varnish. This suppresses the varnish from spreading to the edges during the rinsing process, allowing for effective removal. Furthermore, polyimide precursors that generally exhibit high heat resistance do not have good solubility in solvents that are not highly polar. However, if the varnish contains structures derived from specific aromatic tetracarboxylic dianhydrides having a bent structure, a structure with high steric hindrance, or a structure that can freely rotate, and structures derived from specific diamines having an ester skeleton that exhibits high linearity and relatively low water absorption, it is believed that the solubility of the polyimide precursor can be increased, and the resin obtained after thermal imidization will have excellent heat resistance. As described above, according to the preferred configuration of the varnish, a polyimide resin with excellent heat resistance can be obtained, and it is believed that it will have better cleaning properties with the rinsing solution.

[0079] The varnish may be the polyimide resin precursor itself or the polyimide resin precursor solution after the production of the polyimide resin, or the polyimide resin solution itself, or it may be a solution that has been further diluted by mixing in a solvent.

[0080] The varnish may contain other components, to the extent that they do not impair the desired properties of the resulting polyimide resin layer and varnish. Examples of other components include imidation catalysts, dehydration catalysts, inorganic fillers, adhesion promoters, release agents, flame retardants, UV stabilizers, surfactants, leveling agents, defoamers, fluorescent whitening agents, crosslinking agents, polymerization initiators, and photosensitive agents.

[0081] When the varnish is a polyimide resin precursor varnish, the imidation catalyst and dehydration catalyst can be included from the viewpoint of efficiently promoting the imidation of the polyamic acid portion of the polyimide resin precursor. As the imidation catalyst, an imidation catalyst with a boiling point of 40°C or higher is preferred. If the imidation catalyst has a boiling point of 40°C or higher, imidation can proceed sufficiently before volatilization. Examples of imidation catalysts include amine compounds such as pyridine and picoline; imidazole compounds such as imidazole, 1,2-dimethylimidazole, 1-benzylimidazole, 1-benzyl-2-methylimidazole, and benzimidazole; and the like. The above imidation catalysts may be used alone or in combination of two or more. Examples of dehydration catalysts include acid anhydrides such as acetic anhydride, propionic anhydride, n-butyric anhydride, benzoic anhydride, and trifluoroacetic anhydride; and carbodiimide compounds such as dicyclohexylcarbodiimide. These may be used alone or in combination of two or more.

[0082] The varnish preferably contains 3 to 40% by mass of a polyimide resin precursor or polyimide resin, and more preferably 5 to 30% by mass. The viscosity of the varnish is preferably 0.1 to 100 Pa·s, and more preferably 0.1 to 20 Pa·s. The viscosity of the varnish is the value measured at 25°C using an E-type viscometer. The method for producing the varnish is not particularly limited, and known methods can be applied. For example, it can be obtained by adjusting the concentration of a solution of polyimide resin precursor or polyimide resin obtained by the above-described production method by mixing in additional solvents as needed.

[0083] [Step 2: Rinse Cleaning Step] Step 2 is a step of cleaning the end region of the support substrate with a rinse solution containing a ketone-based organic solvent (R1) and an alcohol-based organic solvent (R2). In this specification, this step is also referred to as the "rinse cleaning step".

[0084] <Rinsing Solution> The rinsing solution contains a ketone-based organic solvent (R1) and an alcohol-based organic solvent (R2). The ketone-based organic solvent (R1) is an organic solvent having a carbonyl group as its main functional group, excluding compounds contained in the alcohol-based organic solvent (R2). The ketone-based organic solvent (R1) is preferably a hydrocarbon compound having a carbonyl group and no other functional groups. The alcohol-based organic solvent (R2) is an organic solvent having an alcoholic hydroxyl group as its main functional group, and the alcohol-based organic solvent (R2) is preferably a hydrocarbon compound having an alcoholic hydroxyl group and no other functional groups. By washing with the rinsing solution, a semiconductor wafer free of resin residue on the substrate edges and back surface can be obtained. It is believed that the amino group structure of the polyimide resin precursor and polyimide resin in the resin layer reacts with the carbonyl group of the ketone-based organic solvent, causing the resin to deteriorate. Furthermore, it is believed that the altered resin has high solubility in the aforementioned alcohol-based organic solvent, which allows for effective cleaning of the resin on the edges and back surface of the substrate, thereby enabling the production of semiconductor wafers free of resin residue.

[0085] The ketone organic solvent (R1) is preferably at least one selected from the group consisting of acetone, methyl ethyl ketone, diethyl ketone, methyl propyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, and methyl isobutyl ketone; more preferably at least one selected from the group consisting of acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, and methyl isobutyl ketone; even more preferably at least one selected from the group consisting of acetone and methyl ethyl ketone; and even more preferably acetone. The ketone organic solvent (R1) may consist of one compound or two or more compounds.

[0086] The alcoholic organic solvent (R2) is preferably at least one selected from the group consisting of isopropyl alcohol, methanol, ethanol, 1-propanol, 2-methoxyethanol, 1-methoxy-2-propanol, 1-butanol, 2-butanol, t-butyl alcohol, and ethylene glycol; more preferably at least one selected from the group consisting of isopropyl alcohol, methanol, ethanol, and 1-methoxy-2-propanol; even more preferably at least one selected from the group consisting of isopropyl alcohol, methanol, and ethanol; and even more preferably isopropyl alcohol. The alcoholic organic solvent (R2) may consist of one compound or two or more compounds.

[0087] Therefore, preferred combinations of ketone-based organic solvent (R1) and alcohol-based organic solvent (R2) are as follows: Preferably, the ketone-based organic solvent (R1) is at least one selected from the group consisting of acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, and methyl isobutyl ketone, and the alcohol-based organic solvent (R2) is at least one selected from the group consisting of isopropyl alcohol, methanol, and ethanol. More preferably, the ketone-based organic solvent (R1) is at least one selected from the group consisting of acetone and methyl ethyl ketone, and the alcohol-based organic solvent (R2) is at least one selected from the group consisting of isopropyl alcohol, methanol, and ethanol. Even more preferably, the ketone-based organic solvent (R1) is acetone and the alcohol-based organic solvent (R2) is isopropyl alcohol. The above combination of ketone-based organic solvent (R1) and alcohol-based organic solvent (R2) allows for better removal of the resin at the edges of the substrate.

[0088] The volume ratio [(R1) / (R2)] of the ketone-based organic solvent (R1) to the alcohol-based organic solvent (R2) in the rinse solution is preferably 30 / 70 to 99 / 1, more preferably 40 / 60 to 98 / 2, even more preferably 50 / 50 to 97 / 3, even more preferably 50 / 50 to 95 / 5, and even more preferably 60 / 40 to 95 / 5. By having the above volume ratio of ketone-based organic solvent (R1) to alcohol-based organic solvent (R2), the resin at the edges of the substrate can be removed more effectively.

[0089] The total amount of ketone-based organic solvent (R1) and alcohol-based organic solvent (R2) contained in the rinsing solution used in this process is preferably 50% by mass or more, more preferably 70 to 100% by mass, and even more preferably 100% by mass, relative to the total amount of rinsing solution used in this process. The rinsing solution used in this process may consist only of ketone-based organic solvent (R1) and organic solvent (R2).

[0090] This step is a rinsing step in which the end regions of the support substrate are cleaned with a rinsing solution containing a ketone-based organic solvent (R1) and an alcohol-based organic solvent (R2). In this step, preferably, the end regions of the support substrate, on which a polyimide resin precursor-containing layer or a polyimide resin-containing layer is formed on the surface, are cleaned to remove varnish from the ends and back surface. The rotation speed in the rinsing step may be constant, gradually increased, or decreased. The rotation speed is preferably 200 to 4000 rpm, more preferably 250 to 3000 rpm, and even more preferably 300 to 2000 rpm. The duration of the rinsing step is preferably 1 to 300 seconds, more preferably 5 to 200 seconds, and even more preferably 10 to 100 seconds. The discharge pressure of the rinsing solution is preferably 0.01 to 0.4 MPa, more preferably 0.02 to 0.3 MPa, and even more preferably 0.03 to 0.2 MPa. As described above, step 1 may be performed again after step 2, and then step 2 may be performed again. Steps 1 and 2 may be repeated two or more times in this manner to gradually thicken the polyimide resin precursor-containing layer or the polyimide resin-containing layer. A spin-drying step may be added after step 2 (rinsing step) to remove any remaining rinse liquid from the edges. In this case, the spin-drying time is preferably 0.01 to 10 seconds, more preferably 0.05 to 5 seconds, and even more preferably 0.1 to 3 seconds.

[0091] [Step 3: Polyimide Resin Layer Formation Step] Step 3 is a step in which the polyimide resin-containing layer or polyimide resin precursor-containing layer is converted into a polyimide resin layer by heating and drying after Step 2. In this specification, this step is also referred to as the "polyimide resin layer formation step".

[0092] In this process, after step 2, it is preferable to dry the varnish at 40 to 150°C using a hot plate or the like to remove some of the solvent. After that, it is preferable to completely remove the solvent, and if a polyimide resin precursor-containing layer is formed in step 1, it is preferable to dry the polyimide resin precursor using an oven or the like to imidize it by heating. The heating temperature for completely removing the solvent and imidizing is preferably 250 to 450°C, more preferably 300 to 420°C, and even more preferably 350 to 400°C. The heating time is preferably 1 minute to 6 hours, more preferably 5 minutes to 2 hours, and even more preferably 15 minutes to 1 hour. Heating at such temperatures and times results in good physical properties for the resulting polyimide resin layer. Examples of heating atmospheres include air, nitrogen gas, oxygen gas, hydrogen gas, and nitrogen / hydrogen mixed gas, but in order to suppress discoloration of the resulting polyimide resin, nitrogen gas with an oxygen concentration of 100 ppm or less, and nitrogen / hydrogen mixed gas containing hydrogen at a concentration of 0.5% or less are preferred. Furthermore, the imidation method is not limited to thermal imidation; chemical imidation can also be applied.

[0093] The preferred physical properties of the polyimide resin constituting the polyimide resin layer are as follows. By satisfying the following physical properties, the polyimide resin exhibits excellent heat resistance. The glass transition temperature (Tg) is preferably 300°C or higher, more preferably 330°C or higher, even more preferably 350°C or higher, even more preferably 400°C or higher, even more preferably 420°C or higher, even more preferably 430°C or higher, even more preferably 440°C or higher, and even more preferably 450°C or higher. The glass transition temperature can be specifically measured by the method described in the examples.

[0094] The thickness of the polyimide resin layer is preferably 3 μm or more, more preferably 5 μm or more, even more preferably 10 μm or more, even more preferably 20 μm or more, and even more preferably 30 μm or more. Alternatively, it is preferably 250 μm or less, more preferably 200 μm or less, even more preferably 150 μm or less, and even more preferably 100 μm or less. Having a thickness within the above range allows for practical use as a protective film, insulating film, or planarizing film. The thickness of the polyimide resin layer can be easily controlled by adjusting the solid content concentration and viscosity of the varnish.

[0095] The polyimide resin layer functions as both a planarizing film for flattening the surface and an insulating film. Because semiconductor wafers having the polyimide resin layer possess the above-mentioned excellent properties, they can be used in various applications, but are particularly suitable for use in semiconductor components where the polyimide resin layer is used as a protective film, insulating film, and planarizing film for the semiconductor.

[0096] [Semiconductor Wafer] A semiconductor wafer manufactured by the above manufacturing method is also included in the present invention. The semiconductor wafer of the present invention is a semiconductor wafer manufactured by the above manufacturing method. More specifically, the semiconductor wafer of the present invention is a semiconductor wafer manufactured by a manufacturing method comprising step 1 of forming a polyimide resin precursor-containing layer or a polyimide resin-containing layer on a support substrate, and step 2 of cleaning the edge region of the support substrate with a rinsing solution containing a ketone-based organic solvent (R1) and an alcohol-based organic solvent (R2).

[0097] The semiconductor wafer of the present invention is manufactured by a manufacturing method comprising steps 1 and 2, but preferably by a manufacturing method comprising step 3, in which the polyimide resin-containing layer or polyimide resin precursor-containing layer is heated and dried after step 2 to convert it into a polyimide resin layer. By being manufactured by a manufacturing method comprising step 3, the semiconductor wafer of the present invention can be a semiconductor wafer having a polyimide resin layer on a support substrate. Steps 1, 2 and 3 described above are the same as the steps described in the section on [Method for Manufacturing Semiconductor Wafers], and the preferred conditions are also the same. Since the semiconductor wafer of the present invention is obtained by the above method, there is no resin residue on the substrate edges or back surface. Therefore, the semiconductor wafer of the present invention can be used for various applications, but is particularly suitable for use in semiconductor components where the polyimide resin layer is used as a protective film, insulating film, or planarization film for semiconductors.

[0098] The present invention will be specifically described below with reference to examples. However, the present invention is not limited in any way by these examples.

[0099] [Production of Polyimide Resin Precursor Varnish] Production Example 1 (1) Raw Materials, etc. The tetracarboxylic acid component, diamine component, solvent, and their abbreviations used in the production example are as follows. <Tetracarboxylic acid component> DSDA: 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride (manufactured by ChinaTech Chemical (Tianjin) Co., Ltd., compound represented by formula (a1)) PMDA: Pyromellitic anhydride (manufactured by Tokyo Chemical Industries, Ltd., compound represented by formula (a2)) <Diamine component> 4-BAAB: 4-aminophenyl-4-aminobenzoate (manufactured by Nippon Junryo Pharmaceutical Co., Ltd., compound represented by formula (b11)) <Solvent> DMI: 1,3-dimethyl-2-imidazolidinone (manufactured by Mitsui Chemicals, Inc.) GBL: γ-butyrolactone (manufactured by Mitsubishi Chemical Corporation) PGME: Propylene glycol monomethyl ether (manufactured by Kanto Chemical Co., Ltd., product name: 1-methoxy-2-propanol)

[0100] (2) Preparation of polyimide resin precursor varnish A 500 mL five-necked round-bottom flask equipped with a stainless steel crescent-shaped stirring blade, nitrogen inlet tube, condenser, thermometer, and glass end cap contained 42.175 g (0.185 mol) of 4-BAAB, 166.202 g of PGME, and 183.620 g of GBL. The mixture was stirred at 200 rpm under a nitrogen atmosphere at a system temperature of 50°C to obtain a solution. 48.256 g (0.124 mol) of DSDA, 9.773 g (0.045 mol) of PMDA, and 49.975 g of DMI were added to this solution. The mixture was stirred for 3 hours while maintaining the temperature at 50°C to obtain a polyimide resin precursor (polyamic acid) varnish (PI-1) with a solid content of 20% by mass. The solvent ratios in the varnish were 36.7% by mass for GBL, 33.2% by mass for PGME, and 10.0% by mass for DMI.

[0101] [Glass transition temperature (Tg) of polyimide resin] The glass transition temperature (Tg) of the polyimide resin contained in the semiconductor wafers obtained by the manufacturing methods of the Examples and Comparative Examples was measured by the following method. A polyimide resin precursor varnish (PI-1) was applied to a 4-inch silicon wafer to a thickness (thickness due to solid content) of 30 μm after drying, and held at 80°C for 30 minutes on a hot plate. Then, in a hot air dryer under a nitrogen atmosphere, the temperature was raised to 400°C at a rate of 5°C / min, and heated at 400°C for 60 minutes to evaporate the solvent and thermal imide formation, thereby obtaining a polyimide resin film. Using a thermomechanical analyzer "TMA 7100C" (manufactured by Hitachi High-Tech Science Co., Ltd.), a TMA measurement was performed on a sample size of 4 mm × 20 mm in tensile mode, with a load of 50 mN and a heating rate of 10°C / min, raising the temperature from 40°C to 500°C. The point where the elongation inflection point was observed was extrapolated to determine the glass transition temperature (Tg). The glass transition temperature (Tg) of the polyimide resin was 459°C.

[0102] [Manufacturing of Rinse Solution] Manufacturing Examples 2-8 (1) Raw Materials, etc. The abbreviations of the solvents used in the manufacturing examples are as follows: <Solvents> Acetone: Acetone (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., ketone-based organic solvent (R1)) IPA: Isopropyl alcohol (manufactured by Kanto Chemical Co., Ltd., alcohol-based organic solvent (R2)) Cyclopentanone: Cyclopentanone (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., ketone-based organic solvent (R1)) PGME: Propylene glycol monomethyl ether (manufactured by Kanto Chemical Co., Ltd., product name: 1-methoxy-2-propanol, alcohol-based organic solvent (R2))

[0103] (2) The solvents shown in Table 1 were placed in the container for preparing the rinse solution and mixed to obtain the rinse solution.

[0104] [Evaluation of varnish solubility in each rinse solution] 15 mL of the varnish obtained in Production Example 1 and 85 mL of the rinse solution obtained in Production Example were placed in a 200 mL glass container and shaken at 25°C for 3 minutes. The state of the mixture was visually observed and evaluated every minute. The time it took for the varnish and the polyimide resin precursor contained in the varnish to dissolve, and the state of the mixture were evaluated according to the following criteria. The results are shown in Table 1. (Evaluation criteria) A: Dissolved within 1 minute from the start of shaking, and a uniformly dissolved mixture (solution) was obtained. B: Did not dissolve after 1 minute of shaking, but dissolved within 3 minutes from the start of shaking, and a uniformly dissolved mixture (solution) was obtained. C: Did not dissolve after 3 minutes of shaking, precipitates (polyimide resin precursor) were observed, and the mixture was non-uniform.

[0105]

[0106] [Manufacturing of Semiconductor Wafers] Examples 1-3 and Comparative Examples 1-4 (Manufacturing of Semiconductor Wafers Having a Polyimide Resin Layer) <Step 1: Process for Forming a Polyimide Resin Precursor-Containing Layer> A polyimide resin precursor varnish (PI-1) was spin-coated onto a 4-inch silicon wafer (substrate) using a spin coater (MS-B200, manufactured by Mikasa Corporation) so that the thickness after drying (thickness due to solid content) was 30 μm. <Step 2: Rinse Cleaning Process> Next, the outlet of the rinsing liquid was adjusted so that the silicon wafer was rinsed inwards from the outer edge by a width of 5 mm, and edge rinsing was performed at 250 rpm for 60 seconds using the rinsing liquid shown in Table 2. <Step 3: Polyimide Resin Layer Formation Process> After that, the substrate was dried on an 80°C hot plate until the coated surface was tack-free to obtain a semiconductor wafer.

[0107] [Evaluation of Rinse Cleanability during Semiconductor Wafer Manufacturing] The presence or absence of resin residue on the outer periphery (substrate edge) of the semiconductor wafers obtained in the examples and comparative examples was evaluated visually. The evaluation criteria are as follows. The evaluation results are shown in Table 2. (Evaluation Criteria) A: No resin residue within a 5 mm range from the outer periphery. C: Resin residue is present within a 5 mm range from the outer periphery.

[0108]

[0109] The semiconductor wafer obtained by the method of the example showed no resin residue in the substrate edge region after rinsing (step 2). As described above, it can be seen that, according to the semiconductor wafer manufacturing method of the present invention, even semiconductor wafers having a thick polyimide resin layer can be obtained without resin residue on the substrate edges or back surface. From this, it can be seen that the semiconductor wafer manufacturing method of the present invention is suitable for manufacturing semiconductor wafers having a polyimide resin layer as a protective film, insulating film, or planarization film for semiconductors.

Claims

Step 1: Forming a polyimide resin precursor-containing layer or a polyimide resin-containing layer on a support substrate, A method for manufacturing a semiconductor wafer, comprising step 2 of cleaning the edge region of the support substrate with a rinsing solution containing a ketone-based organic solvent (R1) and an alcohol-based organic solvent (R2). 　 A method for manufacturing a semiconductor wafer according to claim 1, further comprising step 3, which involves heating and drying after step 2 to convert the polyimide resin-containing layer or polyimide resin precursor-containing layer into a polyimide resin layer, wherein the thickness of the polyimide resin layer is 3 μm or more. 　 A method for producing a semiconductor wafer according to claim 1 or 2, wherein the ketone organic solvent (R1) is at least one selected from the group consisting of acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, and methyl isobutyl ketone, and the alcohol organic solvent (R2) is at least one selected from the group consisting of isopropyl alcohol, methanol, ethanol, and 1-methoxy-2-propanol. 　 The method for manufacturing a semiconductor wafer according to claim 1 or 2, wherein the volume ratio [(R1) / (R2)] of the ketone-based organic solvent (R1) and the alcohol-based organic solvent (R2) in the rinse solution is 50 / 50 to 95 / 5. 　 The polyimide resin precursor-containing layer contains a polyimide resin precursor, and the polyimide resin-containing layer contains a polyimide resin. The polyimide resin precursor and the polyimide resin have a constituent unit A derived from tetracarboxylic dianhydride and a constituent unit B derived from diamine. The constituent unit A includes a constituent unit (A1) which is at least one selected from the group consisting of a constituent unit (A11) derived from a compound represented by the following formula (a11) and a constituent unit (A12) derived from a compound represented by the following formula (a12). Constituent unit B includes a constituent unit (B1) derived from a compound represented by the following formula (b1), A method for manufacturing a semiconductor wafer according to claim 1 or 2. (In formula (a11), X is a single bond, an ether group, a carbonyl group, a sulfone group, an ester group, an amide group, a sulfide group, a phenylene group, an oxyphenyl ether group, a bisphenoxyfluorene group, an isopropylidene group, a hexafluoroisopropylidene group, or a fluorenylidene group. In formula (a12), Y １ and Y ２ Each of these is a single bond, an ether group, a carbonyl group, a sulfone group, an ester group, an amide group, a sulfide group, a phenylene group, an oxyphenyl ether group, a bisphenoxyfluorene group, a hexafluoroisopropylidene group, an isopropylidene group, or a fluorenylidene group. In formula (b1), Z is a single bond, an ether group, a carbonyl group, a sulfone group, an ester group, an amide group, a sulfide group, a phenylene group, an oxyphenyl ether group, a bisphenoxyfluorene group, an isopropylidene group, a hexafluoroisopropylidene group, or a fluorenylidene group. 　 A method for manufacturing a semiconductor wafer according to claim 5, wherein the constituent unit (A11) includes a constituent unit (A111) derived from a compound represented by the following formula (a111). A method for manufacturing a semiconductor wafer according to claim 5, wherein the constituent unit (B1) includes a constituent unit (B11) derived from a compound represented by the following formula (b11). The method for manufacturing a semiconductor wafer according to claim 5, wherein the constituent unit A further comprises at least one selected from the group consisting of a constituent unit (A2) derived from a compound represented by the following formula (a2), a constituent unit (A3) derived from a compound represented by the following formula (a3), and a constituent unit (A4) derived from a compound represented by the following formula (a4). (In equation (a3), n is either 1 or 2.) 　 A semiconductor wafer manufactured by the method described in claim 1 or 2.

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