Decomposition cleaning composition and method for producing the same, and method for cleaning adhesive polymers

Abstract

Provided is a decomposing / cleaning composition having a high etching speed. The decomposing / cleaning composition contains: (A) an N-substituted amide compound, in which 2 alkyl groups are bonded to an amide nitrogen atom, as an aprotic solvent; and (B) a quaternary ammonium alkyl fluoride or a hydrate thereof. The content of an N-substituted amide acid derivative, which is a compound in which 2 hydrogen atoms on a carbon atom at the α-position of the amide nitrogen atom of the N-substituted amide compound (A) are substituted with oxo groups, is 550 ppm by mass or less.

Description

[Technical Field]

[0001] This disclosure relates to a decomposition cleaning composition, a method for manufacturing the same, and a method for cleaning adhesive polymers. In particular, this disclosure relates to a composition that can be used to decompose and clean adhesives containing adhesive polymers used for temporary bonding between a device wafer and a support wafer (carrier wafer) that remain on a device wafer in a semiconductor wafer thinning process, a method for manufacturing the same, and a method for cleaning adhesive polymers using the said composition. [Background technology]

[0002] In three-dimensional packaging technology for increasing semiconductor density, the thickness of each semiconductor wafer is reduced, and multiple semiconductor wafers connected by through-silicon viables (TSVs) are stacked. Specifically, the side (back side) of a device wafer on which a semiconductor device has been formed is thinned by polishing, and then electrodes containing TSVs are formed on that back side.

[0003] In the polishing process of the back surface of the device wafer, a support wafer, also called a carrier wafer, is temporarily bonded to the semiconductor device formation surface of the device wafer using an adhesive in order to impart mechanical strength to the device wafer. For example, a glass wafer or a silicon wafer is used as the support wafer. After the polishing process, if necessary, metal wiring or electrode pads containing Al, Cu, Ni, Au, etc., inorganic films such as oxide films or nitride films, or a resin layer containing polyimide, etc., are formed on the polished surface (back surface) of the device wafer. Then, the back surface of the device wafer is bonded to a tape having an acrylic adhesive layer, which is fixed by a ring frame, thereby fixing the device wafer to the tape. After that, the device wafer is separated from the support wafer (debonding), the adhesive on the device wafer is peeled off, and any adhesive residue on the device wafer is washed away using a cleaning agent.

[0004] For temporary bonding of device wafers, adhesives containing polyorganosiloxane compounds with good heat resistance as adhesive polymers are used. In particular, when the adhesive is a crosslinked polyorganosiloxane compound, the cleaning agent is required to perform two actions: cleaving of Si-O bonds and dissolution of decomposition products by the solvent. Examples of such cleaning agents include fluorine-based compounds such as tetrabutylammonium fluoride (TBAF) dissolved in a polar aprotic solvent. Since the fluoride ions of TBAF are involved in cleaving Si-O bonds via Si-F bond formation, etching properties can be imparted to the cleaning agent. Polar aprotic solvents can dissolve TBAF and do not form solvation with fluoride ions via hydrogen bonding, thereby increasing the reactivity of fluoride ions.

[0005] Non-patent document 1 (Advanced Materials, 11, 6, 492 (1999)) describes the use of a 1.0 M TBAF solution with aprotic THF as the solvent for the decomposition and dissolution of polydimethylsiloxane (PDMS).

[0006] Non-patent document 2 (Advanced Materials, 13, 8, 570 (2001)) uses NMP, DMF, and DMSO, which are aprotic solvents, as solvents for TBAF, similar to THF.

[0007] Non-patent document 3 (Macromolecular Chemistry and Physics, 217, 284-291 (2016)) describes the results of investigating the etching rate of PDMS with TBAF / organic solvents for each solvent. For THF and DMF, which have high etching rates, the document also describes a comparison of the etching rates of TBAF solutions using mixed solvents with varying THF / DMF ratios. [Prior art documents] [Non-patent literature]

[0008] [Non-Patent Document 1] Advanced Materials, 11, 6, 492 (1999) [Non-Patent Document 2] Advanced Materials, 13, 8, 570 (2001) [Non-Patent Document 3] Macromolecular Chemistry and Physics, 217, 284 - 291 (2016) [Summary of the Invention] [Problems to be Solved by the Invention]

[0009] In a decomposition cleaning composition containing a fluorine compound such as TBAF and a solvent, the role of the solvent is considered to be to sufficiently dissolve a highly polar fluorine compound which is a reactive substance, ensure the reactivity of fluoride ions contained in the fluorine compound, and dissolve the decomposition products of the adhesive. An aprotic N-substituted amide compound, for example, N-methylpyrrolidone (NMP), is known to be advantageously used as a solvent for the decomposition cleaning composition because it can dissolve the decomposition products of the adhesive without adversely affecting the reactivity of fluoride ions.

[0010] However, the present inventors have found that when an aprotic N-substituted amide compound is used as a solvent for the decomposition cleaning composition, a sufficient etching rate (ER) may not be obtained.

[0011] The present disclosure aims to provide a decomposition cleaning composition showing a high etching rate. [Means for Solving the Problems]

[0012] The inventors have found that a decomposition cleaning composition containing quaternary alkylammonium fluoride or its hydrate, and an N-substituted amide compound in which two alkyl groups are bonded to an amide nitrogen atom, inevitably contains oxidized derivatives (peroxides, hydroxides, or imide compounds) generated by the oxidation of the N-substituted amide compound, and that a high etching rate can be obtained by keeping the content of such oxidized derivatives below a predetermined value.

[0013] In other words, the present invention encompasses the following [1] to

[16] . [1] A decomposition cleaning composition comprising (A) an N-substituted amide compound in which two alkyl groups are bonded to an amide nitrogen atom, and (B) a quaternary alkylammonium fluoride or its hydrate, wherein the content of an N-substituted amide oxidation derivative, which is a compound in which two hydrogen atoms on the carbon atom at the α position of the amide nitrogen atom of the (A) N-substituted amide compound are substituted with oxo groups, is 550 ppm by mass or less. [2] The decomposition cleaning composition according to [1], wherein the bromide ion concentration is 100 ppm by mass or less. [3] The decomposition cleaning composition according to [1] or [2], further comprising (C) an ether compound as an aprotic solvent. [4] The decomposition cleaning composition according to [3], wherein the total content of the (A) N-substituted amide compound and the (C) ether compound is 70 to 99.99% by mass. [5] The above (A)N-substituted amide compound is of formula (1): [ka] (In equation (1), R 1 (This represents an alkyl group with 1 to 4 carbon atoms.) It is a 2-pyrrolidone derivative compound represented by the following: The N-substituted amide oxide derivative is given by formula (4): [ka] (In formula (4), R 1 represents an alkyl group having 1 to 4 carbon atoms.) The decomposition cleaning composition according to any one of [1] to [4], which is an N-substituted succinimide compound represented by [6] The (A) N-substituted amide compound is a 2-pyrrolidone derivative compound in which R 1 in formula (1) is a methyl group or an ethyl group, the decomposition cleaning composition according to [5]. [7] The (C) ether compound is represented by formula (2): R 2 O(C n H 2n O) x R 3 (2) (In formula (2), R 2 and R 3 each independently represent an alkyl group selected from the group consisting of a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a t-butyl group, n is 2 or 3, and x is an integer of 1 to 4.) The decomposition cleaning composition according to [3] or [4], which contains a dialkyl ether of glycol represented by [8] The dialkyl ether of glycol is dipropylene glycol dimethyl ether, the decomposition cleaning composition according to [7]. [9] The (C) ether compound is represented by formula (3): R 4 OR 5 (3) (In the formula, R 4 and R 5 each independently represent an alkyl group having 4 to 8 carbon atoms.) The decomposition cleaning composition according to any one of [3], [4], [7], and [8], which contains a dialkyl ether represented by

[10] The dialkyl ether is dibutyl ether, the decomposition cleaning composition according to [9].

[11] The above (B) quaternary alkylammonium fluoride is R 6 R 7 R 8 R 9 N + F - It is a tetraalkylammonium fluoride represented by R 6 ~R 9 A decomposition cleaning composition according to any one of [1] to

[10] , wherein each of the alkyl groups is independently selected from the group consisting of a methyl group, an ethyl group, an n-propyl group, an isopropyl group, and an n-butyl group.

[12] The decomposition cleaning composition according to any one of [1] to

[11] , wherein the content of (B) quaternary alkylammonium fluoride is 0.01 to 10% by mass.

[13] A decomposition and cleaning composition for adhesive polymers, as described in any one of [1] to

[12] .

[14] The decomposition cleaning composition according to

[13] , wherein the adhesive polymer is a polyorganosiloxane compound.

[15] A method for cleaning an adhesive polymer on a substrate using a decomposition cleaning composition described in any of [1] to

[14] .

[16] A method for producing a decomposition cleaning composition containing (A) an N-substituted amide compound in which two alkyl groups are bonded to an amide nitrogen atom, and (B) a quaternary alkylammonium fluoride or its hydrate, as an aprotic solvent, A method for producing a decomposition cleaning composition, comprising mixing the (A) N-substituted amide compound and the (B) quaternary alkylammonium fluoride or its hydrate, such that the content of the N-substituted amide oxide derivative, which is a compound in which two hydrogen atoms on the carbon atom at the α position of the amide nitrogen atom of the (A) N-substituted amide compound are substituted with oxo groups, is 550 ppm by mass or less with respect to the decomposition cleaning composition. [Effects of the Invention]

[0014] The decomposition cleaning composition of this disclosure exhibits a high etching rate.

[0015] The foregoing description shall not be deemed to disclose all embodiments of the present invention and all advantages relating to the present invention. [Brief explanation of the drawing]

[0016] [Figure 1] The decomposition cleaning compositions of Example 16 (denoted as N2) and Comparative Example 7 (denoted as Air), as well as the 19F NMR spectra of tetrabutylammonium bifluoride (denoted as TBAHF2), are shown. [Modes for carrying out the invention]

[0017] The present invention will be described in more detail below. However, the present invention is not limited to the embodiments shown below.

[0018] [Decomposition and cleaning composition] One embodiment of the decomposition cleaning composition contains (A) an N-substituted amide compound in which two alkyl groups are bonded to an amide nitrogen atom, and (B) a quaternary alkylammonium fluoride or its hydrate as an aprotic solvent. In this embodiment of the decomposition cleaning composition, the content of an N-substituted amide oxide derivative (hereinafter simply referred to as "N-substituted amide oxide derivative"), which is a compound in which two hydrogen atoms on the carbon atom at the α position of the amide nitrogen atom of the N-substituted amide compound are substituted with oxo groups, is 550 ppm by mass or less.

[0019] The decomposition cleaning composition of this disclosure contains an N-substituted amide compound (hereinafter simply referred to as "N-substituted amide compound") in which two alkyl groups are bonded to an amide nitrogen atom, as an aprotic solvent. N-substituted amide compounds are known to be gradually oxidized upon contact with oxygen to produce oxidized derivatives.

[0020] For example, when N-methylpyrrolidone (NMP) is oxidized by oxygen in the air or dissolved oxygen in a solvent or decomposition cleaning composition, NMP oxidation derivatives are produced by the following mechanism, including the peroxide 5-hydroperoxy-1-methyl-2-pyrrolidinone (NMP-5-OOH), the hydroxide 5-hydroxy-1-methyl-2-pyrrolidinone (NMP-5-OH), and the imide compound N-methylsuccinimide (NMS). NMP-5-OOH and NMP-5-OH are ultimately converted to NMS, which has a chemically stable structure. [ka]

[0021] Therefore, decomposition cleaning compositions containing an N-substituted amide compound as an aprotic solvent inevitably contain, under normal manufacturing and storage conditions, compounds in which two hydrogen atoms on the carbon atom at the α-position of the amide nitrogen atom of the N-substituted amide compound are replaced by oxo groups (=O) as oxidized derivatives of the N-substituted amide compound. Although we do not wish to be bound by any theory, the peroxides and hydroxides that are intermediate products of the oxidation reaction of N-substituted amide compounds are supplied by quaternary alkylammonium fluorides and fluoride ions (F - It has activity against fluoride ions and converts them into bifluoride ions (HF2 - It is converted to ). Bifluoride ions have lower reactive activity, for example, in cleaving Si-O bonds, compared to fluoride ions. Therefore, among decomposition cleaning compositions containing N-substituted amide compounds as aprotic solvents, those containing a large amount of the above-mentioned compound, which is the final oxidation product of the N-substituted amide compound, are thought to exhibit a lower etching rate because the concentration of fluoride ions in the decomposition cleaning composition is reduced.

[0022] In this embodiment of the decomposition cleaning composition, a high etching rate can be obtained because the content of a compound in which two hydrogen atoms on the carbon atom at the α position of the amide nitrogen atom of an N-substituted amide compound are substituted with an oxo group is below a predetermined value.

[0023] <(A) N-substituted amide compounds in which two alkyl groups are bonded to the amide nitrogen atom> N-substituted amide compounds, in which two alkyl groups are bonded to an amide nitrogen atom, are relatively polar aprotic solvents that can uniformly dissolve or disperse quaternary alkylammonium fluorides and their hydrates in a composition. In this disclosure, the two alkyl groups in the N-substituted amide compound may be the same or different. The number of carbon atoms in each alkyl group is preferably 1 to 10, and more preferably 1 to 5. One of the alkyl groups may be involved in the formation of a cyclic amide compound. In this disclosure, "N-substituted amide compound" also includes urea compounds (carbamide compounds) in which two alkyl groups are bonded to an amide nitrogen atom. Various compounds can be used as N-substituted amide compounds without particular limitations. Examples include acyclic N-substituted amides such as N,N-dimethylformamide, N,N-diethylformamide, N,N-dimethylacetamide, N,N-diethylacetamide, N,N-dimethylpropionamide, N,N-diethylpropionamide, and tetramethylurea; cyclic N-substituted amides such as 2-pyrrolidone derivatives, 2-piperidone derivatives, ε-caprolactam derivatives; and 1,3-dimethyl-2-imidazolidinone, 1-methyl-3-ethyl-2-imidazolidinone, 1,3-diethyl-2-imidazolidinone, and 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone (N,N'-dimethylpropyleneurea). Among these, the use of cyclic N-substituted amides is preferred. The N-substituted amide compounds may be one or a combination of two or more.

[0024] In one embodiment, the N-substituted amide compound is given by formula (1): [ka] (In equation (1), R 1 (This represents an alkyl group with 1 to 4 carbon atoms.) It is a 2-pyrrolidone derivative compound represented by. Examples of the alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a t-butyl group, etc. Examples of the 2-pyrrolidone derivative compound represented by the formula (1) include N-methylpyrrolidone (NMP), N-ethylpyrrolidone (NEP), N-propylpyrrolidone, N-butylpyrrolidone, etc.

[0025] Since it has a relatively high polarity, excellent solubility of quaternary alkylammonium fluoride, and is easily available, the N-substituted amide compound is, in formula (1), R 1 is preferably a 2-pyrrolidone derivative compound in which is a methyl group or an ethyl group, and in formula (1), R 1 is more preferably a 2-pyrrolidone derivative compound in which is a methyl group, that is, N-methylpyrrolidone.

[0026] In one embodiment, the content of the N-substituted amide compound in the decomposition cleaning composition is 70 to 99.99% by mass, preferably 80 to 99.95% by mass, and more preferably 90 to 99.9% by mass. When the decomposition cleaning composition contains an ether compound described later, the total content of the N-substituted amide compound and the ether compound in the decomposition cleaning composition is preferably 70 to 99.99% by mass, more preferably 80 to 99.95% by mass, and even more preferably 90 to 99.9% by mass.

[0027] <N-substituted amide oxidation derivative> The content of the N-substituted amide oxidation derivative in the decomposition cleaning composition of one embodiment is 550 ppm by mass or less. The content of the N-substituted amide oxidation derivative is determined by gas chromatography using the conditions described in the examples. The content of the N-substituted amide oxidation derivative in the decomposition cleaning composition is preferably 500 ppm by mass or less, and more preferably 450 ppm by mass or less.

[0028] For example, in an embodiment where the N-substituted amide compound is a 2-pyrrolidone derivative compound represented by formula (1), the N-substituted amide oxidation derivative is formula (4): [ka] (In equation (4), R 1 (This represents an alkyl group with 1 to 4 carbon atoms.) This is an N-substituted succinimide compound represented by [formula].

[0029] <(B) Quaternary alkylammonium fluoride or its hydrate> Quaternary alkylammonium fluorides or their hydrates release fluoride ions that are involved in the cleavage of Si-O bonds. Due to the quaternary alkylammonium moiety, the salts of quaternary alkylammonium fluorides can be dissolved in aprotic solvents. Various compounds can be used as quaternary alkylammonium fluorides without particular limitations. Examples of hydrates of quaternary alkylammonium fluorides include trihydrates, tetrahydrates, and pentahydrates. Quaternary alkylammonium fluorides may be one type or a combination of two or more types. The unhydrated and hydrated forms of quaternary alkylammonium fluorides can be used in any ratio.

[0030] In one embodiment, quaternary alkylammonium fluoride is R 6 R 7 R 8 R 9 N + F - It is a tetraalkylammonium fluoride represented by R 6 ~R 9 Each of these is an alkyl group independently selected from the group consisting of a methyl group, an ethyl group, an n-propyl group, an isopropyl group, and an n-butyl group. From the viewpoint of availability, R 6 ~R 9It is preferable that all alkyl groups are the same. Examples of such quaternary alkylammonium fluorides include tetramethylammonium fluoride, tetraethylammonium fluoride, tetrapropylammonium fluoride, and tetrabutylammonium fluoride. From the viewpoint of decomposition and cleaning performance, availability, and price, the quaternary alkylammonium fluoride is preferably tetrabutylammonium fluoride (TBAF).

[0031] In one embodiment, the content of quaternary alkylammonium fluoride in the decomposition cleaning composition is 0.01 to 10% by mass. Here, "content of quaternary alkylammonium fluoride" is the value calculated as the mass of quaternary alkylammonium fluoride only, excluding the mass of hydrated water, if the composition contains hydrated quaternary alkylammonium fluoride. The content of quaternary alkylammonium fluoride in the decomposition cleaning composition is preferably 0.01 to 5% by mass, more preferably 0.05 to 2% by mass, and even more preferably 0.1 to 1% by mass. In another embodiment, the content of quaternary alkylammonium fluoride in the decomposition cleaning composition is preferably 0.5 to 9% by mass, more preferably 1 to 8% by mass, and even more preferably 2 to 5% by mass or 4 to 8% by mass. By setting the quaternary alkylammonium fluoride content to 0.01% by mass or more, adhesive polymers can be effectively decomposed and cleaned, and by setting it to 10% by mass or less, corrosion of metal parts contained in the device formation surface of the device wafer can be prevented or suppressed.

[0032] When prevention or suppression of corrosion of metal parts, or reduction of costs associated with the use of quaternary alkylammonium fluoride, is particularly required, the content of quaternary alkylammonium fluoride in the decomposition cleaning composition may be 4% by mass or less, or 3% by mass or less. When a higher etching rate is required, the content of quaternary alkylammonium fluoride in the decomposition cleaning composition may be 5% by mass or more, 6% by mass or more, or 7% by mass or more.

[0033] <(C) Ether compounds> The decomposition cleaning composition may further contain an ether compound as an aprotic solvent. By combining the ether compound with an N-substituted amide compound, a mixed solvent system exhibiting high affinity to the adhesive surface can be formed. Compositions using such a mixed solvent system can achieve a high etching rate by effectively utilizing the reaction activity of quaternary alkylammonium fluoride. Various compounds can be used as the ether compound without particular limitations. The ether compound may be one or a combination of two or more. It is preferable that the ether compound does not contain an ester structure or an amide structure.

[0034] In one embodiment, the ether compound is of formula (2): R 2 O(C n H 2n O) x R 3 (2) (In equation (2), R 2 and R 3 Each of these independently represents an alkyl group selected from the group consisting of methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and t-butyl groups, where n is 2 or 3 and x is an integer from 1 to 4. It contains a glycol dialkyl ether represented by [formula].

[0035] Examples of glycol dialkyl ethers represented by formula (2) include ethylene glycol dimethyl ether, propylene glycol dimethyl ether, diethylene glycol dimethyl ether, dipropylene glycol dimethyl ether, tripropylene glycol dimethyl ether, tripropylene glycol diethyl ether, tripropylene glycol di-n-butyl ether, tetraethylene glycol dimethyl ether, and tetrapropylene glycol dimethyl ether. From the viewpoint of decomposition cleaning performance, availability, and price, the glycol dialkyl ether represented by formula (2) is preferably diethylene glycol dimethyl ether or dipropylene glycol dimethyl ether, and more preferably dipropylene glycol dimethyl ether because a high etching rate can be obtained over a wide range of compositions.

[0036] The content of the dialkyl ether of glycol represented by formula (2) is preferably 10 to 80% by mass, more preferably 15 to 70% by mass, and even more preferably 20 to 60% by mass, when the aprotic solvent is considered to be 100% by mass. In another embodiment, the content of the dialkyl ether of glycol represented by formula (2) is preferably 0 to 60% by mass, more preferably 3 to 50% by mass, and even more preferably 5 to 40% by mass, when the aprotic solvent is considered to be 100% by mass.

[0037] In one embodiment, the ether compound is of formula (3): R 4 Ure 5 (3) (In the formula, R 4 and R 5 Each of these independently represents an alkyl group with 4 to 8 carbon atoms. It contains a dialkyl ether represented by [formula].

[0038] The ether compound may include a glycol dialkyl ether represented by formula (2) and a dialkyl ether represented by formula (3). By using a combination of two or more ether compounds with different polarities in this way, the affinity to various adhesive surfaces can be effectively enhanced, and a composition with a wide range of applications can be obtained.

[0039] Examples of dialkyl ethers represented by formula (3) include dibutyl ether, dipentyl ether, dihexyl ether, diheptyl ether, dioctyl ether, butylhexyl ether, and butyloctyl ether. Dibutyl ether is preferred as the dialkyl ether represented by formula (3) from the viewpoint of decomposition cleaning performance, availability, and price.

[0040] The content of the dialkyl ether represented by formula (3) is preferably 0 to 50% by mass, more preferably 1 to 35% by mass, and even more preferably 2 to 30% by mass, when the aprotic solvent is considered to be 100% by mass. By setting the content of the dialkyl ether represented by formula (3) to 0% by mass or more and 50% by mass or less, a higher etching rate can be obtained. In another embodiment, the content of the dialkyl ether represented by formula (3) is preferably 30 to 70% by mass, more preferably 35 to 65% by mass, and even more preferably 40 to 60% by mass, when the aprotic solvent is considered to be 100% by mass.

[0041] In one embodiment, the flash point of the ether compound is 21°C or higher. By using an ether compound with a flash point of 21°C or higher, i.e., one that does not fall under the category of hazardous materials Class 4, Group 1 petroleum, the requirements for equipment, working environment, etc., in the manufacture and use of the composition can be reduced compared to using tetrahydrofuran (THF, flash point -17°C, hazardous materials Class 4, Group 1 petroleum). For example, the flash points of diethylene glycol dimethyl ether, dipropylene glycol dimethyl ether, and dibutyl ether are 51°C, 60°C, and 25°C, respectively. The flash point is measured by the TAG closure method (JIS K 2265-1:2007).

[0042] <Composition ratio of N-substituted amide compound and ether compound> In one embodiment, when the aprotic solvent is 100% by mass, the content of the N-substituted amide compound is 10 to 90% by mass, and the content of the ether compound is 90 to 10% by mass. When the aprotic solvent is 100% by mass, it is preferable that the content of the N-substituted amide compound is 15 to 85% by mass and the content of the ether compound is 85 to 15% by mass, and it is more preferable that the content of the N-substituted amide compound is 25 to 65% by mass and the content of the ether compound is 75 to 35% by mass. In another embodiment, when the aprotic solvent is 100% by mass, it is preferable that the content of the N-substituted amide compound is 40 to 80% by mass and the content of the ether compound is 60 to 20% by mass. By setting the contents of the N-substituted amide compound and the ether compound within the above ranges, the quaternary alkylammonium fluoride and its hydrate can be uniformly dissolved in the composition, and a high etching rate can be obtained for various adhesive surfaces.

[0043] In one embodiment, when the aprotic solvent is 100% by mass, the content of the N-substituted amide compound is 20 to 90% by mass, the content of the dialkyl ether of glycol represented by formula (2) is 10 to 80% by mass, and the content of the dialkyl ether represented by formula (3) is 0 to 30% by mass. Preferably, the content of the N-substituted amide compound is 25 to 80% by mass, the content of the dialkyl ether of glycol represented by formula (2) is 20 to 60% by mass, and the content of the dialkyl ether represented by formula (3) is 0 to 30% by mass. In another embodiment, when the aprotic solvent is 100% by mass, the content of the N-substituted amide compound is 20 to 90% by mass, the content of the dialkyl ether of glycol represented by formula (2) is 0 to 70% by mass, and the content of the dialkyl ether represented by formula (3) is 0 to 30% by mass. Preferably, the content of the N-substituted amide compound is 30 to 85% by mass, the content of the dialkyl ether of glycol represented by formula (2) is 3 to 50% by mass, and the content of the dialkyl ether represented by formula (3) is 0 to 30% by mass. In yet another embodiment, when the aprotic solvent is 100% by mass, the content of the N-substituted amide compound is 20 to 80% by mass, the content of the dialkyl ether of glycol represented by formula (2) is 10 to 50% by mass, and the content of the dialkyl ether represented by formula (3) is 30 to 60% by mass.

[0044] <Additives and other ingredients> The decomposition cleaning composition may contain additives such as antioxidants, surfactants, preservatives, and anti-foaming agents as optional components, to the extent that they do not significantly impair the effects of the present invention.

[0045] In one embodiment, the decomposition cleaning composition is substantially free of or does not contain a protic solvent. For example, the content of the protic solvent in the composition can be 5% by mass or less, 3% by mass or less, or 1% by mass or less. The protic solvent that may be included in the composition may be water derived from quaternary alkylammonium fluoride hydrate.

[0046] In one embodiment, the decomposition cleaning composition is substantially free of or does not contain an aprotic solvent selected from ketones and esters. For example, the content of an aprotic solvent selected from ketones and esters in the composition can be 1% by mass or less, 0.5% by mass or less, or 0.1% by mass or less.

[0047] <Bromide ion concentration> In one embodiment, the bromide ion concentration in the decomposition cleaning composition is 100 ppm by mass or less. The bromide ion concentration is determined by ion chromatography using the conditions described in the example. Preferably, the bromide ion concentration in the decomposition cleaning composition is 90 ppm by mass or less, and more preferably 70 ppm by mass or less. Even when prepared with the same formulation, the decomposition cleaning composition may exhibit color variations. By setting the bromide ion concentration in the decomposition cleaning composition to 100 ppm by mass or less, the color variations of the decomposition cleaning composition can be reduced.

[0048] [Method for manufacturing a decomposition cleaning composition] The method for producing the decomposition cleaning composition is not particularly limited. The decomposition cleaning composition can be prepared by mixing an N-substituted amide compound, a quaternary alkylammonium fluoride or its hydrate, and other optional components.

[0049] The decomposition cleaning composition is preferably prepared by mixing an N-substituted amide compound, a quaternary alkylammonium fluoride or its hydrate, and other optional components under an inert gas atmosphere. For example, one method involves stirring and mixing the N-substituted amide compound, a quaternary alkylammonium fluoride or its hydrate, and other optional components in a glove box filled with an inert gas using a stirrer or the like to dissolve the quaternary alkylammonium fluoride or its hydrate in a solvent. The inert gas is preferably argon gas or nitrogen gas, and more preferably nitrogen gas.

[0050] The peroxide value (POV) of the N-substituted amide compound used in the production of the decomposition cleaning composition is preferably 10 meq / L or less. The peroxide value is determined by iodine titration using the conditions described in the examples. The peroxide value of the N-substituted amide compound is more preferably 7 meq / L or less, and even more preferably 5 meq / L or less. The peroxide value of the N-substituted amide compound serves as an indicator of the degree of oxidation of the N-substituted amide compound. By using an N-substituted amide compound with a peroxide value of 10 meq / L or less, the content of N-substituted amide oxidation derivatives in the decomposition cleaning composition can be reduced, and a decomposition cleaning composition with a high etching rate can be obtained.

[0051] [How to use the decomposition cleaning composition] The decomposition and cleaning compositions of this disclosure can be used as decomposition and cleaning compositions for adhesive polymers contained in various adhesives. The adhesive polymer is not particularly limited as long as it can be cleaned using the decomposition and cleaning compositions of this disclosure. In addition to the adhesive polymer, the adhesive may optionally contain curing agents, curing accelerators, crosslinking agents, surfactants, leveling agents, fillers, and the like.

[0052] <Adhesive polymer> In one embodiment, the adhesive polymer contains Si-O bonds. The adhesive polymer becomes low-molecular-weight or loses its cross-linked structure due to the cleavage of the Si-O bonds by fluoride ions of quaternary alkylammonium fluoride, making it soluble in a solvent, and as a result, the adhesive polymer can be removed from surfaces such as device wafers.

[0053] The adhesive polymer containing Si-O bonds is preferably a polyorganosiloxane compound. Since polyorganosiloxane compounds contain numerous siloxane bonds (Si-O-Si), they can be effectively decomposed and cleaned using decomposition and cleaning compositions. Examples of polyorganosiloxane compounds include silicone elastomers, silicone gels, and silicone resins such as MQ resins, as well as modified versions thereof such as epoxy modified, acrylic modified, methacrylic modified, amino modified, and mercapto modified versions. The polyorganosiloxane compound may also be a silicone modified polymer such as a silicone-modified polyurethane or a silicone-modified acrylic resin.

[0054] In one embodiment, the adhesive polymer is an addition-curing silicone elastomer, silicone gel, or silicone resin. These addition-curing silicones contain an ethylenically unsaturated group-containing polyorganosiloxane, such as vinyl-terminated polydimethylsiloxane or vinyl-terminated MQ resin, and a crosslinking agent such as polyorganohydrogensiloxane, such as polymethylhydrogensiloxane, and are cured using a hydrosilylation catalyst such as a platinum catalyst.

[0055] In another embodiment, the adhesive polymer may include at least one selected from the group consisting of methyl group-containing polyorganosiloxanes, epoxy group-containing polyorganosiloxanes, and phenyl group-containing polyorganosiloxanes. These polyorganosiloxanes are preferably at least one selected from the group consisting of polydimethylsiloxanes, epoxy group-containing polydimethylsiloxanes, and phenyl group-containing polydimethylsiloxanes.

[0056] Addition-curing silicone may be combined with at least one selected from the group consisting of methyl group-containing polyorganosiloxane, epoxy group-containing polyorganosiloxane, and phenyl group-containing polyorganosiloxane.

[0057] [Method for cleaning adhesive polymers] Cleaning of adhesive polymers on substrates such as silicon wafers can be performed using a decomposition cleaning composition in various conventionally known methods. Examples of methods for cleaning adhesive polymers include discharging the decomposition cleaning composition onto the substrate while rotating the substrate at a predetermined speed using a spin coater or the like so as to bring it into contact with the adhesive polymer (spin etching), spraying the decomposition cleaning composition onto the adhesive polymer on the substrate (spraying), and immersing the substrate having the adhesive polymer in a tank containing the decomposition cleaning composition (dipping). The temperature for decomposition cleaning may vary depending on the type and amount of adhesive polymer on the substrate, and is generally 20°C to 90°C, preferably 40°C to 60°C. The time for decomposition cleaning may vary depending on the type and amount of adhesive polymer on the substrate, and is generally 5 seconds to 10 hours, preferably 10 seconds to 2 hours. Ultrasound may be applied to the bath of the decomposition cleaning composition or the substrate during decomposition cleaning.

[0058] After disassembly and cleaning, the substrate may be rinsed with an alcohol such as isopropyl alcohol (IPA) or deionized water (DIW), and the substrate may be dried by spraying with nitrogen gas or air, or by heating under normal pressure or reduced pressure.

[0059] [Method for manufacturing device wafers] In one embodiment, the method for manufacturing a device wafer includes cleaning the adhesive polymer on the device wafer using a decomposition cleaning composition. After cleaning, the device wafer may be rinsed or dried as needed.

[0060] The method for manufacturing a device wafer may further include the following steps: obtaining a device wafer by forming a semiconductor device on a substrate such as a silicon wafer; temporarily bonding the device wafer and the support wafer via an adhesive containing an adhesive polymer, with the semiconductor device formation surface of the device wafer facing the support wafer; thinning the device wafer by polishing the opposite side (back surface) of the device wafer from the device formation surface; and separating the support wafer from the device wafer. The formation of the semiconductor device, the temporary bonding of the device wafer and the support wafer, the polishing of the back surface of the device wafer, and the separation of the device wafer from the support wafer can be carried out by conventionally known methods and are not particularly limited.

[0061] [Method for regenerating support wafers] The decomposition cleaning composition can be used to regenerate support wafers used in the manufacture of device wafers. In one embodiment, the method for regenerating a support wafer includes cleaning the adhesive polymer on the support wafer using the decomposition cleaning composition. After cleaning, the support wafer may be rinsed or dried as needed. [Examples]

[0062] The present invention will be described in more detail below based on examples and comparative examples, but the present invention is not limited to the examples.

[0063] [Preparation of N-methylpyrrolidone (NMP)] Four types of NMP were prepared as raw materials for the decomposition and cleaning composition: unopened NMP (NMP-1) and NMP (NMP-2 to NMP-4) with three different exposure times to air after opening. The peroxide value and N-methylsuccinimide (NMS) concentration of NMP-1 to NMP-4 were measured using the following procedure.

[0064] [Measurement of peroxide value of NMP by iodine titration] A 25 mL mixture of chloroform and acetic acid (chloroform:acetic acid = 2:3 (volume ratio)) was added to a 200 mL conical beaker. Using a volumetric pipette, 10 mL of NMP was added to the mixture and mixed. Furthermore, 1.0 mL of saturated potassium iodide aqueous solution (30 g potassium iodide / 20 mL distilled water) was added to the mixture and mixed, and the resulting solution was allowed to stand in the dark for 10 minutes to allow the peroxides in the NMP to react sufficiently with the iodide ions.

[0065] The mixed solution was removed from the dark, and 30 mL of distilled water and 8 mL of 1% starch aqueous solution were added to the mixed solution to obtain a titration sample. A 0.01 M sodium thiosulfate aqueous solution (Kanto Chemical Co., Ltd.) was added dropwise to the titration sample using a 2 mL microburette until the mixed solution became colorless and transparent. The volume of the added 0.01 M sodium thiosulfate aqueous solution was V (mL), and the peroxide value (POV) was calculated using the following formula. POV(meq / L)=0.01×V / 1000 / 2 / (10 / 1000)×1000 =V / 2

[0066] [Measurement of NMS concentration in NMP by GC analysis] The concentrations of NMS contained in NMP-1 to NMP-4 were measured by gas chromatography under the following conditions. Gas chromatograph: GC-17A (Shimadzu Corporation) Column: Agilent J&W GC Column DB-WAX (Agilent Technologies, Inc.), inner diameter 0.32 mm, length 60 m Column temperature: Hold at 140°C for 13 minutes → Increase temperature at 20°C / min → 250°C Detector: FID

[0067] Table 1 shows the peroxide values ​​and NMS concentrations of NMP-1 to NMP-4.

[0068] [Table 1]

[0069] [Preparing for TBAF] Two types of commercially available 98% pure tetrabutylammonium fluoride trihydrate (TBAF·3H2O) were prepared as raw materials for the decomposition and cleaning composition. The concentration of bromide ions contained in these TBAF·3H2O samples was measured using the following procedure.

[0070] [Measurement of bromide ions contained in TBAF·3H2O] Under a nitrogen gas atmosphere, 20 mg of TBAF·3H2O was weighed out and used as a sample. This sample was placed in a sample combustion apparatus AQF-100 (Nitto Seikou Analytech Co., Ltd.) and burned and decomposed by heating to 900°C under an oxygen stream while passing water vapor through it.

[0071] Bromine contained in the sample was absorbed by bubbling the gas generated by combustion decomposition into 5 mL of absorption solution. The absorption solution was prepared by the following procedure: 10.6 g of sodium carbonate (special grade, Kanto Chemical Co., Ltd.) was dissolved in deionized water. A 1 M Na2CO3 aqueous solution was prepared by adding the resulting solution to a 100 mL volumetric flask and making up the volume. 10 mL of 1 M Na2CO3 aqueous solution, 1.5 mL of hydrogen peroxide solution (for atomic absorption spectrometry, Kanto Chemical Co., Ltd.), and 5 mL of 1000 μg / mL phosphate ion standard solution (Kanto Chemical Co., Ltd.) were added to a 500 mL volumetric flask, and the volume was made up to 500 mL with deionized water to prepare the absorption solution. The concentrations of the components in the absorption solution were as follows. Na2CO3:20mM Hydrogen peroxide solution: 1.5 mL / 500 mL PO4 3- : 10 μg / mL

[0072] The bromide ions contained in the obtained absorption solution were measured by ion chromatography under the following conditions. Ion chromatograph: DIONEX ICS-1600 (Thermo Fisher Scientific Co., Ltd.) Eluent: 2.7mM Na2CO3+0.3mM NaHCO3 Column: DIONEX AG12A / AS12A (Thermo Fisher Scientific Co., Ltd.), inner diameter 4mm Column temperature: 30℃ Flow rate: 1.5mL / min Injection volume: 100μL Detector: Electrical conductivity detector

[0073] The amount of bromide ions in TBAF·3H2O was calculated by dividing the amount of bromide ions in the absorption solution by the amount of TBAF·3H2O. The bromide ion concentrations of two commercially available TBAF·3H2O products were 10 ppm by mass and 1000 ppm by mass, respectively. Hereafter, TBAF·3H2O with a bromide ion concentration of 10 ppm by mass will be referred to as "TBAF-Br10", and TBAF·3H2O with a bromide ion concentration of 1000 ppm by mass will be referred to as "TBAF-Br1000".

[0074] [Preparation of decomposition cleaning composition] Decomposition and cleaning compositions were prepared using NMP-1 to NMP-4, as well as TBAF-Br10 and TBAF-Br1000.

[0075] [Example 1] In a glove box filled with nitrogen gas, 4.748 g of TBAF-Br1000 was added to a 125 mL polyethylene container, followed by 35.157 g of NMP-1, 3.504 g of dipropylene glycol dimethyl ether (DPGDME), and 6.598 g of dibutyl ether (DBE). The mixture was then mixed to dissolve the TBAF-Br1000. In this way, a decomposition washing composition of 7.7 mass% TBAF mixed solvent was prepared, containing 95 mass ppm (calculated value) of bromide ions and having a mass ratio of NMP:DPGDME:DBE of 0.777:0.077:0.146. The decomposition washing composition was transferred to a 50 mL glass colorimetric tube, filled with nitrogen gas, and then the colorimetric tube was sealed with a glass stopper.

[0076] [Example 2] In a glove box filled with nitrogen gas, 3.561 g of TBAF-Br1000 and 1.189 g of TBAF-Br10 were added to a 125 mL polyethylene container. Then, 35.147 g of NMP-1, 3.502 g of DPGDME, and 6.598 g of DBE were added in that order and mixed to dissolve TBAF-Br1000 and TBAF-Br10. In this way, a decomposition washing composition of a 7.7 mass% TBAF mixed solvent containing 71 mass ppm (calculated value) of bromide ions and with a mass ratio of NMP:DPGDME:DBE of 0.777:0.077:0.146 was prepared. The decomposition washing composition was transferred to a 50 mL glass colorimetric tube, filled with nitrogen gas, and then the colorimetric tube was sealed with a glass stopper.

[0077] [Examples 3-15, Comparative Examples 1-6] The decomposition cleaning composition was prepared using the same procedure as in Example 1 or 2, except that the composition was as shown in Table 2.

[0078] [Preparation of silicon wafer test specimens having an adhesive layer containing polyorganosiloxane compounds] An addition-curing silicone resin was applied to a 12-inch (300 mm) silicon wafer (770 μm thick) by spin coating to a dry film thickness of 110 μm. Then, an adhesive layer was formed on the silicon wafer by heating it on a hot plate at 140°C for 15 minutes and then at 190°C for 10 minutes. The silicon wafer with the adhesive layer containing a polyorganosiloxane compound was divided into 1.5 cm × 1.5 cm sections to prepare test specimens.

[0079] [Washing test] A 50cc screw-cap vial was placed on a magnetic stirrer. 15.0 mL of the decomposition and cleaning composition and a stirring bar were added to the vial. One test specimen was immersed in the decomposition and cleaning composition, and the stirring bar was rotated at 900 rpm for 3 minutes at room temperature (25°C). After immersion, the test specimen was removed with tweezers and thoroughly rinsed using an isopropyl alcohol (IPA) wash bottle. After drying the test specimen by blowing nitrogen gas onto it, the thickness of the center of the test specimen was measured using a micrometer. The etching rate (ER) of the decomposition and cleaning composition was calculated by dividing the difference in the thickness of the test specimen before and after immersion by the immersion time in the decomposition and cleaning composition. Etching rate (ER) (μm / min) = [(Thickness of specimen before immersion - Thickness of specimen after immersion, washing, and drying) (μm)] / Immersion time (3 minutes)

[0080] Table 2 shows the compositions and evaluation results of Examples 1-15 and Comparative Examples 1-6.

[0081] [Table 2]

[0082] [Example 16 and Comparative Example 7] A decomposition cleaning composition was prepared using a 5% by mass TBAF mixed solvent with a mass ratio of NMP:DPGDME of 0.764:0.236, following the same procedure as in Example 1. The prepared decomposition cleaning composition was stored in a nitrogen gas atmosphere for 16 months to obtain the decomposition cleaning composition of Example 16, in which the concentration of N-methylsuccinimide (NMS) was 550 ppm or less. Similarly, the decomposition cleaning composition prepared was stored in an air atmosphere for 16 months to obtain the decomposition cleaning composition of Comparative Example 7, in which the concentration of N-methylsuccinimide (NMS) was greater than 550 ppm.

[0083] Regarding the decomposition cleaning compositions of Example 16 and Comparative Example 7, 19 F NMR measurements were performed. Figure 1 shows the decomposition washing compositions of Example 16 (labeled N2) and Comparative Example 7 (labeled Air), as well as tetrabutylammonium bifluoride (labeled TBAHF2, manufactured by Sigma-Aldrich Japan LLC). 19The F NMR spectrum is shown. The high-intensity peak around -115 ppm observed in the decomposition washing composition of Example 16 is due to fluoride ions (F) derived from tetrabutylammonium fluoride. - ) is attributed to ). In the decomposition cleaning composition of Comparative Example 7, the peak around -115 ppm disappeared, and instead, bifluoride ions (HF2) were present. - The area of ​​the peak around -148 to -150 ppm, which is attributed to ), was increased. [Industrial applicability]

[0084] The decomposition cleaning composition of the present invention can be suitably used for decomposing and cleaning residues of adhesives used in semiconductor wafer thinning processes, particularly adhesives containing polyorganosiloxane compounds as adhesive polymers, from device wafers.

Claims

1. A decomposition cleaning composition comprising (A) an N-substituted amide compound in which two alkyl groups are bonded to an amide nitrogen atom, and (B) a quaternary alkylammonium fluoride or its hydrate, wherein the content of an N-substituted amide oxidation derivative, which is a compound in which two hydrogen atoms on the carbon atom at the α position of the amide nitrogen atom of the N-substituted amide compound are substituted with oxo groups, is 450 ppm by mass or less.

2. The decomposition cleaning composition according to claim 1, wherein the bromide ion concentration is 100 ppm by mass or less.

3. The decomposition cleaning composition according to claim 1 or 2, further comprising a (C) ether compound as an aprotic solvent.

4. The decomposition cleaning composition according to claim 3, wherein the total content of the (A) N-substituted amide compound and the (C) ether compound is 70 to 99.99% by mass.

5. The above (A)N-substituted amide compound is of formula (1): 【Chemistry 1】 (In equation (1), R １ (This represents an alkyl group with 1 to 4 carbon atoms.) It is a 2-pyrrolidone derivative compound represented by the following: The N-substituted amide oxide derivative is of formula (4): 【Chemistry 2】 (In equation (4), R １ (This represents an alkyl group with 1 to 4 carbon atoms.) The decomposition cleaning composition according to claim 1 or 2, wherein the N-substituted succinimide compound is represented by [formula].

6. The above (A)N-substituted amide compound is R in formula (1). １ The decomposition cleaning composition according to claim 5, wherein the compound is a 2-pyrrolidone derivative compound in which the compound is a methyl group or an ethyl group.

7. The (C) ether compound is of formula (2): R ２ O(C ｎ H ２ｎ O) ｘ R ３ (2) (In formula (2), R ２ and R ３ each independently represent an alkyl group selected from the group consisting of a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a t-butyl group, n is 2 or 3, and x is an integer from 1 to 4.) The decomposition cleaning composition according to claim 3, comprising a glycol dialkyl ether represented by .

8. The decomposition cleaning composition according to claim 7, wherein the dialkyl ether of the glycol is dipropylene glycol dimethyl ether.

9. The (C) ether compound is of formula (3): R ４ OR ５ (3) (In the formula, R ４ and R ５ Each of these independently represents an alkyl group with 4 to 8 carbon atoms. The decomposition cleaning composition according to claim 3, comprising a dialkyl ether represented by [the specified symbol].

10. The decomposition cleaning composition according to claim 9, wherein the dialkyl ether is dibutyl ether.

11. The above (B) quaternary alkylammonium fluoride is R ６ R ７ R ８ R ９ N ＋ F － This is a tetraalkylammonium fluoride represented by R ６ ~R ９ The decomposition cleaning composition according to claim 1 or 2, wherein each of them is an alkyl group independently selected from the group consisting of a methyl group, an ethyl group, an n-propyl group, an isopropyl group, and an n-butyl group.

12. The decomposition cleaning composition according to claim 1 or 2, wherein the content of (B) quaternary alkylammonium fluoride is 0.01 to 10% by mass.

13. The decomposition and cleaning composition according to claim 1 or 2, which is a decomposition and cleaning composition for adhesive polymers.

14. The decomposition cleaning composition according to claim 13, wherein the adhesive polymer is a polyorganosiloxane compound.

15. A method for cleaning an adhesive polymer on a substrate using the decomposition cleaning composition described in claim 1 or 2.

16. A method for producing a decomposition cleaning composition containing (A) an N-substituted amide compound in which two alkyl groups are bonded to an amide nitrogen atom, and (B) a quaternary alkylammonium fluoride or its hydrate, as an aprotic solvent, A method for producing a decomposition cleaning composition, comprising mixing the (A) N-substituted amide compound and the (B) quaternary alkylammonium fluoride or its hydrate, such that the content of the N-substituted amide oxide derivative, which is a compound in which two hydrogen atoms on the carbon atom at the α position of the amide nitrogen atom of the (A) N-substituted amide compound are substituted with oxo groups, is 450 ppm by mass or less with respect to the decomposition cleaning composition.

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