TW202003428A - Resist composition and patterning process - Google Patents

Abstract

A resist composition comprising a base polymer and an onium salt of N-carbonylsulfonamide having iodized benzene ring offers a high sensitivity, minimal LWR and improved CDU, independent of whether it is of positive or negative tone.

Description

Photoresist material and pattern forming method

The invention relates to a photoresist material and a pattern forming method.

With the expansion of the IoT market, LSIs are increasingly required to be highly integrated, speedy, and low in power consumption, and the pattern rules have been refined rapidly. In particular, logic devices are leading to miniaturization. As the most advanced miniaturization technology, mass production of 10nm node devices using double patterning, triple patterning, and quadruple patterning infiltrating ArF lithography has been carried out, and extreme ultraviolet light with a wavelength of 13.5nm (EUV) The research of 7nm node device which is made by lithography.

In EUV lithography, the line pattern can be formed with a line width of less than 20nm, and chemically amplified photoresist materials can be used. However, the effect of blurring of the image due to acid diffusion becomes greater, so it is more necessary to control acid diffusion than the photoresist for ArF lithography.

For chemically amplified positive photoresist materials that add acid generators and generate acid by light or electron beam (EB) irradiation and cause deprotection reactions, and chemically amplified negative photoresist materials that use acid to cause crosslinking reactions In order to control the diffusion of acid to the unexposed part and improve the contrast, the addition of quencher is very effective. Therefore, many amine quenchers have been proposed (Patent Documents 1 to 3).

As the miniaturization progresses and approaches the diffraction limit of light, the contrast of light decreases. As the contrast of light decreases, the resolution and focus tolerance of the hole pattern and the trench pattern will decrease in the positive photoresist film. In order to prevent the influence of the decrease in the resolution of the photoresist pattern due to the decrease in the contrast of light, attempts have been made to improve the dissolution contrast of the photoresist film.

It has been proposed to use a chemically amplified photoresist material using an acid proliferation mechanism that generates acid due to acid. Generally, as the exposure amount increases, the acid concentration increases linearly, but in the case of acid proliferation, the acid concentration increases nonlinearly and sharply with respect to the increase in exposure amount. The acid proliferation system has the advantage of enhancing the advantages of high contrast and high sensitivity of the chemically amplified photoresist film, but the environmental resistance is deteriorated due to amine pollution, and the limit resolution is reduced due to the increase of the acid diffusion distance. The shortcomings of the chemically amplified photoresist film will be further deteriorated, and it is a very difficult mechanism to control when it is used for practical purposes.

In order to make the contrast better, there is a method of decreasing the concentration of the amine as the exposure amount increases. It is considered that a compound that loses its role as a quencher due to light can be used.

The acid-labile group used in the (meth)acrylate polymer used for the ArF photoresist material will cause the deprotection reaction to proceed due to the use of a photoacid generator that generates a sulfonic acid substituted with fluorine in the α position, but the α position is generated. The acid generators of sulfonic acid and carboxylic acid that are not substituted with fluorine do not undergo deprotection reaction. If the saccharinium salt and the tungsten salt of the sulfonic acid substituted with fluorine in the α position are mixed with the sacium salt and the tungsten salt in which the sulfonic acid which has not been substituted with fluorine in the α position is mixed, the saccharinated sulfonate of the sulfonic acid which has not been substituted in the α position is produced Salts and iodide salts will undergo ion exchange with sulfonic acid substituted with fluorine at the α position. The sulfonic acid substituted with fluorine in the α position due to light will be restored to the osmium salt and the iodonium salt by ion exchange. Therefore, the sulfonic acid not substituted with the fluorine in the α position, the osmium salt of the carboxylic acid and the iodonium salt are used as quenchers. effect.

In addition, the osmium salt and the gallium salt of the sulfonic acid that has not been substituted with fluorine at the α position lose their ability to act as a quencher due to photolysis, so they also function as photodegradable quenchers. The structural formula is unknown, but it is shown that the addition of the photodecomposable quencher increases the tolerance of the trench pattern (Non-Patent Document 1). However, the impact on the performance improvement is minimal, and it is hoped that a quencher will be developed to make the contrast better.

Patent Document 4 proposes that a carboxylic acid having an amine group is generated due to light, and it generates an internal amide due to an acid, resulting in an onium salt-type quencher with reduced basicity. Due to the mechanism of decreasing the alkalinity due to acid, the diffusion of acid is controlled in the unexposed part where the amount of acid generation is small, and the overexposure part where the amount of acid generation is overexposed is due to the quencher. The alkalinity decreases and the acid diffusion increases. By this, the difference between the acid amount of the exposed part and the unexposed part can be increased, and the contrast can be improved. But in this case, there is the benefit of improved contrast but the effect of acid diffusion control is reduced.

With the miniaturization of patterns, the edge roughness (LWR) of line patterns and the uniformity of size (CDU) of hole patterns are considered as problems. The nonuniformity of the base polymer and the acid generator, the influence of aggregation, and the influence of acid diffusion have been criticized. Furthermore, as the photoresist film becomes thinner, LWR tends to increase, and as the film becomes thinner, the deterioration of LWR becomes a serious problem.

EUV photoresist materials need to achieve high sensitivity, high resolution, low LWR, and low CDU at the same time. If the acid diffusion distance is short, the LWR decreases but the sensitivity is low. For example, by reducing the post-exposure baking (PEB) temperature, the LWR decreases, but the sensitivity is low. When the amount of quencher added increases, LWR decreases, but the sensitivity is low. It is necessary to break the trade-off relationship between sensitivity and LWR and CDU. In addition, EB and EUV are also high-energy rays, and there is also a relationship between sensitivity and LWR and CDU.

The energy of EUV is much higher than that of ArF excimer laser. The number of photons in EUV exposure is 1/14 of that in ArF exposure. And the size of the pattern formed by EUV exposure is less than half of ArF exposure. Therefore, EUV exposure is susceptible to variations in the number of photons. In the very short-wavelength emission region, the variation in the number of photons is shot noise of a physical phenomenon, and its influence cannot be eliminated.

Stochastics are gradually being promoted. Although the impact of shot noise cannot be eliminated, some people discuss how to reduce its impact. The impact of shot noise will not only increase CDU and LWR, but will also observe the phenomenon of hole clogging with a probability of one millionth. If the hole is clogged, the electrical conduction is poor, and the transistor does not operate, so it will adversely affect the performance of the entire device. As for the method of reducing the impact of shot noise on the photoresist side, it has been proposed to increase the absorption of the photoresist and absorb more photons. Since the polymer photoresist material will cause variation, a single-component low molecular light is developed Resistance (Non-Patent Document 2).

As an acid generator that increases the absorption of the photoresist, there has been proposed a photoresist material to which an acid generator having an onium side with an onium salt of iodine is added (Patent Documents 5 and 6). With this, the sensitivity and LWR or CDU can be better. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2001-194776 [Patent Document 2] Japanese Unexamined Patent Publication No. 2002-226470 [Patent Document 3] Japanese Patent Application Publication No. 2002-363148 [Patent Document 4] Japanese Patent Laid-Open No. 2015-90382 [Patent Document 5] Japanese Patent Application Publication No. 2018-5224 [Patent Document 6] Japanese Patent Laid-Open No. 2015-25789 [Non-patent literature]

[Non-Patent Document 1] SPIE Vol. 7639 p76390W (2010) [Non-Patent Document 2] SPIE Vol. 9776 p97760V-1 (2016)

(Problem to be solved by invention)

In the case of chemically amplified photoresist materials using acid as a catalyst, it is hoped to develop a high-sensitivity photoresist material that can reduce LWR and CDU quenchers and acid generators, and can contribute to the reduction of shot noise.

In view of the foregoing circumstances, the present invention aims to provide positive resist materials and negative resist materials that are both high-sensitivity photoresist materials with low LWR and CDU, and a pattern forming method using the photoresist materials. (How to solve the problem)

The inventors of the present case worked hard to achieve the aforementioned objectives, and found that by using the onium salt of N-carbonylsulfonamide with an iodinated benzene ring as a quencher or acid generator, high sensitivity and LWR can be obtained The invention is completed with small CDU, high contrast and excellent resolution, and processing photoresist materials with wide latitude.

式中，R¹ 為氫原子、羥基、碳數1～6之烷基、碳數1～6之烷氧基、碳數2～7之醯氧基、碳數2～7之烷氧基羰基、碳數1～4之烷基磺醯氧基、氟原子、氯原子、溴原子、胺基、硝基、氰基、-NR^1A -C(＝O)-R^1B 、或-NR^1A -C(＝O)-O-R^1B ；該烷基、烷氧基、醯氧基、烷氧基羰基及烷基磺醯氧基之氫原子之一部分或全部也可取代為鹵素原子；R^1A 為氫原子、或碳數1～6之烷基；R^1B 為碳數1～6之烷基、或碳數2～8之烯基； R² 為碳數1～10之烷基、或碳數6～10之芳基，其氫原子之一部分或全部也可以取代為胺基、硝基、氰基、碳數1～12之烷基、碳數1～12之烷氧基、碳數2～12之烷氧基羰基、碳數2～12之醯基、碳數2～12之烷基羰氧基、羥基、或鹵素原子； X¹ 為單鍵、或碳數1～20之2價連結基，也可以含有醚鍵、羰基、酯鍵、醯胺鍵、磺內酯環、內醯胺環、碳酸酯鍵、鹵素原子、羥基或羧基； m及n為符合1≦m≦5、0≦n≦4、及1≦m＋n≦5之整數； M⁺ 為下式(Aa)表示之鋶陽離子、下式(Ab)表示之錪陽離子或下式(Ac)表示之銨陽離子； [化2]

式中，R^a1 ～R^a3 各自獨立地為鹵素原子、或也可以含有雜原子之碳數1～20之1價烴基；又，也可R^a1 、R^a2 及R^a3 中之任二者互相鍵結並和它們所鍵結之硫原子一起形成環； R^a4 及R^a5 各自獨立地為鹵素原子、或也可以含有雜原子之碳數1～20之1價烴基； R^a6 ～R^a9 各自獨立地為氫原子、或碳數1～24之1價烴基，也可含有鹵素原子、羥基、羧基、醚鍵、酯鍵、硫醇基、硫酯鍵、硫羰酯鍵、雙硫酯鍵、胺基、硝基、碸基或二茂鐵基；R^a6 與R^a7 亦可互相鍵結並和它們所鍵結之氮原子一起形成環，R^a6 與R^a7 及R^a8 與R^a9 ，也可各自互相鍵結並和它們所鍵結之氮原子一起形成螺環，也可R^a8 與R^a9 合併而形成＝C(R^a10 )(R^a11 )；R^a10 及R^a11 各自獨立地為氫原子、或碳數1～16之1價烴基；又，R^a10 與R^a11 亦可互相鍵結並和它們所鍵結之碳原子及氮原子一起形成環，該環之中也可以含有雙鍵、氧原子、硫原子或氮原子。 2. 如1.之光阻材料，其中，m為符合2≦m≦4之整數。 3. 如1.或2.之光阻材料，更含有產生磺酸、醯亞胺酸或甲基化酸之酸產生劑。 4. 如1.至3.中任一項之光阻材料，更含有有機溶劑。 5. 如1.至4.中任一項之光阻材料，其中，該基礎聚合物含有下式(a1)表示之重複單元、或下式(a2)表示之重複單元； [化3]

式中，R^A 各自獨立地為氫原子或甲基；Y¹ 為單鍵、伸苯基或伸萘基、或含有酯鍵或內酯環之碳數1～12之連結基；Y² 為單鍵或酯鍵；R¹¹ 及R¹² 為酸不安定基。 6. 如5.之光阻材料，係化學增幅正型光阻材料。 7. 如1.至4.中任一項之光阻材料，其中，該基礎聚合物不含酸不安定基。 8. 如7.之光阻材料，更含有交聯劑。 9. 如7.或8.之光阻材料，係化學增幅負型光阻材料。 10. 如1.至9.中任一項之光阻材料，其中，該基礎聚合物更含有選自下式(f1)～(f3)表示之重複單元中之至少1種； [化4]

式中，R^A 各自獨立地為氫原子或甲基； Z¹ 為單鍵、伸苯基、-O-Z¹¹ -、-C(＝O)-O-Z¹¹ -或-C(＝O)-NH-Z¹¹ -，Z¹¹ 為碳數1～6之烷二基、碳數2～6之烯二基、或伸苯基，也可以含有羰基、酯鍵、醚鍵或羥基； Z² 為單鍵、-Z²¹ -C(＝O)-O-、-Z²¹ -O-或-Z²¹ -O-C(＝O)-，Z²¹ 為碳數1～12之烷二基，也可以含有羰基、酯鍵或醚鍵； Z³ 為單鍵、亞甲基、伸乙基、伸苯基、氟化伸苯基、-C(＝O)-O-Z³¹ -或-C(＝O)-NH-Z³¹ -，Z³¹ 為碳數1～6之烷二基、伸苯基、氟化伸苯基、經三氟甲基取代之伸苯基、或碳數2～6之烯二基，也可以含有羰基、酯鍵、醚鍵或羥基； A為氫原子或三氟甲基； R²¹ ～R²⁸ 各自獨立地為也可以含有雜原子之碳數1～20之1價烴基；又，R²³ 、R²⁴ 及R²⁵ 中之任二者、或R²⁶ 、R²⁷ 及R²⁸ 中之任二者，也可互相鍵結並和它們所鍵結之硫原子一起形成環； M^- 為非親核性相對離子。 11. 如1.至10.中任一項之光阻材料，更含有界面活性劑。 12. 一種圖案形成方法，包括下列步驟： 將如1.至11.中任一項之光阻材料塗佈在基板上，進行加熱處理而形成光阻膜； 將該光阻膜以高能射線曝光；及 使用顯影液將已曝光之光阻膜進行顯影。 13. 如12.之圖案形成方法，其中，該高能射線係波長193nm之ArF準分子雷射或波長248nm之KrF準分子雷射。 14. 如12.之圖案形成方法，其中，該高能射線係電子束或波長3～15nm之極紫外線。 15. 一種下式(B)表示之鋶鹽； [化5]

式中，R¹ 、R² 、X¹ 、m、n及R^a1 ～R^a3 同前述。 (發明之效果)That is, the present invention provides the following photoresist materials and pattern forming methods. 1. A photoresist material, including a base polymer and an onium salt represented by the following formula (A); [化1]

In the formula, R ¹ is a hydrogen atom, a hydroxyl group, a C 1-6 alkyl group, a C 1 to 6 alkoxy group, a C 2 to 7 alkoxy group, a C 2 to 7 alkoxycarbonyl group , Alkyl sulfonyloxy group having 1 to 4 carbon atoms, fluorine atom, chlorine atom, bromine atom, amine group, nitro group, cyano group, -NR ^1A -C(=O)-R ^1B , or -NR ^1A- C(=O)-OR ^1B ; part or all of the hydrogen atoms of the alkyl, alkoxy, alkoxy, alkoxycarbonyl and alkylsulfonyloxy groups can also be replaced by halogen atoms; R ^1A is hydrogen Atom, or C 1-6 alkyl; R ^1B is C 1-6 alkyl, or C 2-8 alkenyl; R ² is C 1-10 alkyl, or C 6 Aryl group of ~10, part or all of its hydrogen atoms may be substituted with amine group, nitro group, cyano group, alkyl group with carbon number 1-12, alkoxy group with carbon number 1-12, carbon number with 2-12 Alkoxycarbonyl group, C2-C12 acetyl group, C2-C12 alkylcarbonyloxy group, hydroxyl group, or halogen atom; X ¹ is a single bond, or a C1-C20 divalent linking group , May also contain ether bond, carbonyl group, ester bond, amide bond, sultone ring, lactam ring, carbonate bond, halogen atom, hydroxyl group or carboxyl group; m and n are in accordance with 1≦m≦5, 0≦ n≦4, and an integer of 1≦m+n≦5; M ⁺ is a cation represented by the following formula (Aa), a cation represented by the following formula (Ab) or an ammonium cation represented by the following formula (Ac); [Chem 2]

In the formula, R ^a1 to R ^a3 are each independently a halogen atom, or a C 1-20 monovalent hydrocarbon group which may also contain a heteroatom; and any one of R ^a1 , R ^a2 and R ^a3 may be mutually Bond and form a ring together with the sulfur atom to which they are bonded; R ^a4 and R ^a5 are each independently a halogen atom, or a monovalent hydrocarbon group of 1 to 20 carbon atoms which may also contain a heteroatom; R ^a6 to R ^a9 each It is independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 24 carbon atoms, and may also contain a halogen atom, a hydroxyl group, a carboxyl group, an ether bond, an ester bond, a thiol group, a thioester bond, a thiocarbonyl ester bond, and a dithioester bond , amino, nitro, sulfone or ferrocenyl group; R ^a6 and R ^a7 may be bonded to each other and the nitrogen atom to which they are bonded together form a ring of, R ^a6, and R ^a7 and R ^a8 and R ^a9, may each mutually bonded and the nitrogen atom to which they are bonded's together form a spiro ring, may also be R ^{a8 a9} combined with R to form ^{= C (R a10) (R} a11); R a10 and R ^A11 each independently A hydrogen atom or a monovalent hydrocarbon group having 1 to 16 carbon atoms; in addition, R ^a10 and R ^a11 may also be bonded to each other and form a ring together with the carbon atom and nitrogen atom to which they are bonded, and the ring may also contain a double Bond, oxygen atom, sulfur atom or nitrogen atom. 2. The photoresist material as 1. where m is an integer that meets 2≦m≦4. 3. The photoresist materials such as 1. or 2. further contain acid generators that generate sulfonic acid, imidic acid or methylated acid. 4. The photoresist material according to any one of 1. to 3. further contains an organic solvent. 5. The photoresist material according to any one of 1. to 4., wherein the base polymer contains a repeating unit represented by the following formula (a1), or a repeating unit represented by the following formula (a2); [Chem. 3]

In the formula, R ^{A is} each independently a hydrogen atom or a methyl group; Y ¹ is a single bond, a phenyl group or a naphthyl group, or a linking group having 1 to 12 carbon atoms containing an ester bond or a lactone ring; Y ² is Single bond or ester bond; R ¹¹ and R ¹² are acid labile groups. 6. The photoresist material such as 5. is a chemically amplified positive photoresist material. 7. The photoresist material according to any one of 1. to 4., wherein the base polymer does not contain acid labile groups. 8. The photoresist material as in 7. further contains a cross-linking agent. 9. The photoresist materials such as 7. or 8. are chemically amplified negative photoresist materials. 10. The photoresist material according to any one of 1. to 9., wherein the base polymer further contains at least one selected from repeating units represented by the following formulas (f1) to (f3);

In the formula, R ^{A is} each independently a hydrogen atom or a methyl group; Z ¹ is a single bond, phenylene, -OZ ¹¹ -, -C(=O)-OZ ¹¹ -or -C(=O)-NH- Z ¹¹ -, Z ¹¹ is an alkanediyl group having 1 to 6 carbon atoms, an alkanediyl group having 2 to 6 carbon atoms, or a phenylene group, and may also contain a carbonyl group, an ester bond, an ether bond, or a hydroxyl group; Z ² is a single bond , -Z ²¹ -C(=O)-O-, -Z ²¹ -O- or -Z ²¹ -OC(=O)-, Z ²¹ is an alkanediyl group having 1 to 12 carbon atoms, and may also contain a carbonyl group, Ester bond or ether bond; Z ³ is a single bond, methylene, ethylidene, phenylene, fluorinated phenylene, -C(=O)-OZ ³¹ -or -C(=O)-NH- Z ³¹ -, Z ³¹ is an alkanediyl group having 1 to 6 carbon atoms, a phenylene group, a fluorinated phenylene group, a phenylene group substituted with a trifluoromethyl group, or an alkaneyl group having 2 to 6 carbon atoms, also May contain a carbonyl group, an ester bond, an ether bond, or a hydroxyl group; A is a hydrogen atom or a trifluoromethyl group; R ²¹ to R ²⁸ are each independently a monovalent hydrocarbon group of 1 to 20 carbon atoms which may also contain a heteroatom; and, R Any one of ²³ , R ²⁴ and R ²⁵ , or any two of R ²⁶ , R ²⁷ and R ²⁸ may also be bonded to each other and form a ring together with the sulfur atom to which they are bonded; M ^-is non Nucleophilic relative ion. 11. The photoresist material according to any one of 1. to 10. further contains a surfactant. 12. A pattern forming method, comprising the following steps: applying a photoresist material as described in any one of 1. to 11. on a substrate, and performing a heat treatment to form a photoresist film; exposing the photoresist film to high-energy rays ; And use the developer to develop the exposed photoresist film. 13. The pattern forming method according to 12., wherein the high-energy ray is an ArF excimer laser with a wavelength of 193 nm or a KrF excimer laser with a wavelength of 248 nm. 14. The pattern forming method according to 12., wherein the high-energy rays are electron beams or extreme ultraviolet rays with a wavelength of 3 to 15 nm. 15. A samara salt represented by the following formula (B); [化5]

In the formula, R ¹ , R ² , X ¹ , m, n, and R ^a1 to R ^{a3 are the} same as described above. (Effect of invention)

The photoresist film containing the onium salt of N-carbonylsulfonamide with iodinated benzene ring has a large absorption of EB and EUV due to the sulfonamide with iodinated benzene ring. Electronics can make the sensitivity better. The anion of the above-mentioned onium salt is sterically hindered by the substituents attached to both sides of the amide bond, and the bonding distance with the onium cation is long. Compared with the quencher of the onium salt of carboxylic acid, it is easy to ion exchange with sulfonic acid. That is, the ability as a quencher is high, whereby high contrast can be obtained. In addition, when the sulfonamide group has a fluorinated alkyl group or aryl group, the generated acid has high strength, so it acts as an acid generator. In this case, it acts as an acid generator with little acid diffusion.

[Photoresist] The photoresist material of the present invention contains a base polymer and an onium salt of N-carbonylsulfonamide (hereinafter also referred to as sulfonamide containing iodinated benzene ring) having an iodinated benzene ring. When the above-mentioned onium salt is a manganese salt or a tungsten salt, they are acid generators that generate sulfonamides containing a iodinated benzene ring due to light irradiation, but because of the form of a strong alkaline tungsten salt or a tungsten salt, they are also used as The role of quencher. The aforementioned sulfonamides containing benzene ring iodide generate strong acids when bonded to alkyl and aryl groups substituted with fluorine, and therefore act as acid generators. On the other hand, when there is no fluorine atom, there is no degree of acidity that causes deprotection reaction of acid labile groups. Therefore, as will be described later, in order to cause deprotection reaction of acid labile groups, a sulfonic acid that produces a strong acid is added , Acid generators of imidic acid or methylated acid are effective. In addition, the acid generator that generates sulfonic acid, imidic acid, or methylated acid may be an additive type or a bonding type bonded to the base polymer.

If the aforementioned acid generator of sulfonamide containing iodine benzene ring or sulfonium salt and perfluoroalkyl sulfonic acid generating super strong acid are irradiated in a mixed state, sulfonamide containing iodine benzene ring and Perfluoroalkyl sulfonic acid. The acid generator does not decompose completely, so there is an undecomposed acid generator nearby. Here, if the sulfonamide salt or sulfonium salt containing iodinated benzene ring coexists with perfluoroalkylsulfonic acid, the initial perfluoroalkylsulfonic acid will be the sulfonamide salt containing sulfonamide containing iodinated benzene ring. Or iodide salt ion exchange and generate perfluoroalkyl sulfonium sulfonium salt, release sulfonamide containing iodinated benzene ring. The reason for this is that the perfluoroalkyl sulfonate with high strength in terms of acid is relatively stable. On the other hand, even if the perfluoroalkylsulfonium sulfonium salt or the iodonium salt and the sulfonamide containing the iodinated benzene ring exist, there will be no ion exchange. Not only perfluoroalkylsulfonic acid, the acid strength is higher than arylsulfonic acid, alkylsulfonic acid, imidic acid, methylated acid, etc. containing sulfonamide containing iodinated benzene ring. .

Sulfonamide salts, iodide salts or ammonium salts containing iodinated benzene rings not only inhibit acid diffusion, but also have high EUV absorption, thereby generating secondary electrons, which can increase the sensitivity of the photoresist and reduce shot noise. . Sulfonamide salts, sulfonium salts or ammonium salts containing benzene iodide ring are not only used as acid generators or quenchers for acid diffusion control, but also as sensitizers.

The photoresist material of the present invention needs to contain the sulfonamide salt, iodide salt or ammonium salt of sulfonamide containing benzene iodide ring, but other ramium salt or iodonium salt can also be added as a quenching agent. At this time, the ramium salt and the gallium salt added as the quenching agent are preferably a ramium salt or a gallium salt such as carboxylic acid, sulfonic acid, imidic acid, and saccharin. The carboxylic acid at this time may or may not be fluorinated at the α position.

The photoresist material of the present invention may also include an acid generator composed of a sulfonamide salt or a sulfonium salt of fluorosulfonamide bonded to a fluorine-substituted alkyl group or an aryl group, and an alkyl group bonded to a fluorine atom-free alkyl group 3. The quencher composed of aryl sulfonamide sulfonamide salt is combined.

In order to make LWR better, as described above, it is effective to inhibit the aggregation of polymers and acid generators. In order to suppress the aggregation of the polymer, it is effective to reduce the difference between the hydrophobicity and the hydrophilicity, and lower the glass transition point (Tg). Specifically, it is effective to reduce the difference in polarity between a hydrophobic acid-labile group and a hydrophilic adhesive group, and use a tight adhesive group such as a monocyclic lactone to reduce Tg. In order to suppress the aggregation of the acid generator, it is effective to introduce a substituent or the like into the cation portion of triphenylcarbamate. Especially for the methacrylate polymer for ArF formed with the alicyclic protective group and the adhesive group of the lactone, the triphenyl alkane heterostructure formed only with the aromatic group has a low compatibility. As a substituent introduced into triphenyl alkene, it is considered to be the same alicyclic group or lactone as the base polymer user. The saline salt is hydrophilic, so when the lactone is introduced, the hydrophilicity becomes too high, and the compatibility with the polymer decreases, causing agglomeration of the saline salt. Introducing hydrophobic alkyl group can make the osmium salt evenly dispersed in the photoresist film. International Publication No. 2011/048919 proposes a method for making LWR better by introducing an alkyl group to a sulfonamide salt fluorinated at the α position to produce an alkyl group.

In order to improve LWR, the more attention should be paid to the dispersibility of the quencher. Even if the dispersibility in the photoresist film of the acid generator is improved, if the quencher is unevenly present, it may cause a decrease in LWR. In the quenching agent of the salt type, it is also effective to improve the LWR if the cationic part of the triphenyl alkane is introduced with a substituent such as an alkyl group. In addition, if halogen atoms are introduced into the samium-type quencher, the hydrophobicity can be improved with good efficiency and the dispersibility can be improved. The introduction of large-volume halogen atoms such as iodine is effective not only for the cationic part but also for the anion part of the salt. The aforementioned sulfonamide sulfonate salt containing benzene ring iodide, by introducing iodine atoms into the anion portion, will increase the dispersibility of the quencher in the photoresist film and reduce the LWR.

The aforementioned LWR reduction effect of the sulfonamide sulfonamide-containing sulfonamide salt, iodide salt or ammonium salt containing the iodine benzene ring is effective for the formation of positive patterns, negative patterns, and organic solvents by alkaline development.

[Onium salt of sulfonamide containing benzene iodide ring] The onium salt of sulfonamide containing benzene iodide ring contained in the photoresist of the present invention is represented by the following formula (A). [化6]

In formula (A), R ¹ is a hydrogen atom, a hydroxyl group, a C 1-6 alkyl group, a C 1-6 alkoxy group, a C 2-7 alkoxy group, and a C 2-7 alkyl group Oxycarbonyl, C1-C4 alkylsulfonyloxy, fluorine, chlorine, bromine, amine, nitro, cyano, -NR ^1A -C(=O)-R ^1B , or- NR ^1A -C(=O)-OR ^1B . Part or all of the hydrogen atoms of the aforementioned alkyl, alkoxy, acetyloxy, alkoxycarbonyl and alkylsulfonyloxy groups may also be substituted with halogen atoms. R ^1A is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. R ^1B is an alkyl group having 1 to 6 carbon atoms or an alkenyl group having 2 to 8 carbon atoms.

The alkyl group having 1 to 6 carbon atoms may be linear, branched, or cyclic, and specific examples thereof include methyl, ethyl, n-propyl, isopropyl, cyclopropyl, and n- Butyl, isobutyl, second butyl, third butyl, cyclobutyl, n-pentyl, cyclopentyl, n-hexyl, cyclohexyl, etc. In addition, the alkyl portion of the alkoxy group having 1 to 6 carbon atoms, the alkoxy group having 2 to 7 carbon atoms, and the alkoxycarbonyl group having 2 to 7 carbon atoms may be the same as the specific examples of the aforementioned alkyl group. Examples of the alkyl part of the alkylsulfonyloxy group of 1 to 4 include those having 1 to 4 carbon atoms in the specific examples of the aforementioned alkyl group. The alkenyl group having 2 to 8 carbon atoms may be linear, branched, or cyclic. Specific examples thereof include vinyl, 1-propenyl, and 2-propenyl. Examples of the aralkyl group include benzyl and phenethyl. Among these, R ^{1 is} preferably a fluorine atom, a chlorine atom, a bromine atom, a hydroxyl group, an amine group, an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, and an oxygen group having 2 to 4 carbon atoms. Radical, -NR ^1A -C(=O)-R ^1B , or -NR ^1A -C(=O)-OR ^1B, etc. are preferred.

In formula (A), R ² is an alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 10 carbon atoms, and part or all of its hydrogen atoms may be substituted with an amine group, a nitro group, a cyano group, and a carbon number 1-12 alkyl groups, C 1-12 alkoxy groups, C 2-12 alkoxycarbonyl groups, C 2-12 acetyl groups, C 2-12 alkyl carbonyloxy groups, hydroxyl groups , Or a halogen atom.

The alkyl group having 1 to 10 carbon atoms may be linear, branched, or cyclic. Specific examples of the alkyl group having 1 to 6 carbon atoms include n-heptyl and n-octyl groups. , N-nonyl, n-decyl, adamantyl, etc.

Examples of the aryl group having 6 to 10 carbon atoms include phenyl and naphthyl.

In formula (A), X ¹ is a single bond, or a divalent linking group having 1 to 20 carbon atoms, and may contain an ether bond, a carbonyl group, an ester bond, an amide bond, a sultone ring, a lactam ring, and carbonic acid Ester bond, halogen atom, hydroxyl group or carboxyl group. Among these, as for X ¹ , a single bond is preferred.

In formula (A), m and n are integers that satisfy 1≦m≦5, 0≦n≦4, and 1≦m+n≦5. m is an integer that satisfies 2≦m≦4, and n is preferably 0 or 1.

Examples of the anion of the onium salt represented by formula (A) include the following but are not limited thereto. [化7]

[Chem 8]

[化9]

[化10]

[Chem 11]

[化12]

[Chem 13]

In formula (A), M ⁺ is a cation represented by the following formula (Aa), a cation represented by the following formula (Ab), or an ammonium cation represented by the following formula (Ac). [化14]

式中，R¹ 、R² 、X¹ 、m、n及R^a1 ～R^a3 同前述。For example, when M ⁺ is a cerium cation represented by formula (Aa), the onium salt represented by formula (A) is a cerium salt represented by formula (B) below. [化15]

In the formula, R ¹ , R ² , X ¹ , m, n, and R ^a1 to R ^{a3 are the} same as described above.

In formulas (Aa) and (Ab), R ^a1 to R ^a3 are each independently a halogen atom or a C 1-20 monovalent hydrocarbon group that may contain a hetero atom. Also, any two of ^Ra1 , ^Ra2 and ^Ra3 may be bonded to each other and form a ring together with the sulfur atom to which they are bonded. R ^a4 and R ^a5 are each independently a halogen atom, or a C 1-20 monovalent hydrocarbon group which may contain a hetero atom.

The monovalent hydrocarbon group may be linear, branched, or cyclic. Specific examples thereof include an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, and 2 carbon atoms. ~12 alkynyl, C6-20 aryl, C7-12 aralkyl, C7-12 aryloxyalkyl, etc. In addition, some or all of the hydrogen atoms of these groups may also be substituted with hydroxyl, carboxyl, halogen, pendant, cyano, amide bond, nitro, sultone, sulfonyl, or sulfonate-containing groups Part of the carbon atoms of these groups can also be replaced by ether bonds, ester bonds, carbonyl groups, carbonate bonds or sulfonate bonds.

In formula (Ac), R ^a6 to R ^a9 are each independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 24 carbon atoms, and may also contain a halogen atom, a hydroxyl group, a carboxyl group, an ether bond, an ester bond, a thiol group, and sulfur Ester bond, thiocarbonyl ester bond, dithioester bond, amine group, nitro group, sulfonyl group or ferrocene group. R ^a6 and R ^a7 can also be bonded to each other and form a ring with the nitrogen atom to which they are bonded, R ^a6 and R ^a7 and R ^a8 and R ^a9 can also be bonded to each other and the nitrogen atom to which they are bonded Together, they form a spiro ring, or R ^a8 and R ^a9 may be combined to form =C(R ^a10 )(R ^a11 ). R ^a10 and R ^a11 are each independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 16 carbon atoms. R ^a10 and R ^a11 may be bonded to each other and form a ring together with the carbon atom and nitrogen atom to which they are bonded. The ring may also contain a double bond, an oxygen atom, a sulfur atom or a nitrogen atom.

The monovalent hydrocarbon group having 1 to 24 carbon atoms may be linear, branched, or cyclic. Specific examples thereof include alkyl groups having 1 to 24 carbon atoms, alkenyl groups having 2 to 24 carbon atoms, and carbon atoms. An alkynyl group having 2 to 24 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, a group obtained by combining these, and the like.

The cations represented by the formula (Aa) can be exemplified below but not limited thereto. [Chem 16]

[化17]

[Chemical 18]

[Chem 19]

[化20]

[化21]

[化22]

[化23]

[化24]

[化25]

The antimony cation represented by the formula (Ab) may be exemplified below but not limited thereto. [化26]

The ammonium cation represented by the formula (Ac) can be exemplified below but not limited thereto. [化27]

[Chem 28]

[Chem 29]

[化30]

[化31]

[化32]

[化33]

[化34]

[化35]

[化36]

[化37]

[化38]

[化39]

[化40]

[化41]

[化42]

[化43]

[化44]

[化45]

[化46]

As a method for synthesizing the onium salt represented by the formula (A), a method of performing ion exchange with an onium salt of a weaker acid than sulfonamide containing a iodinated benzene ring can be cited. Examples of the acid that is weaker than sulfonamide containing a iodinated benzene ring include hydrochloric acid, carbonic acid, carboxylic acid, and sulfonic acid that does not contain a fluorine atom. Also, the sodium salt of sulfonamide containing iodinated benzene ring and the like can be synthesized by ion exchange with the onium chloride salt.

In the photoresist material of the present invention, the content of the onium salt represented by the formula (A) is preferably 0.001 to 50 parts by mass with respect to 100 parts by mass of the base polymer described later in consideration of sensitivity and acid diffusion suppression effect, and 0.01 to 20 Quality is more ideal.

[Base polymer] When the base polymer contained in the photoresist material of the present invention is a positive photoresist material, it contains a repeating unit containing an acid labile group. As the repeating unit containing an acid labile group, a repeating unit represented by the following formula (a1) (hereinafter also referred to as repeating unit a1) or a repeating unit represented by the formula (a2) (hereinafter also referred to as repeating unit a2) is preferred good. [化47]

In the formula, R ^{A is} each independently a hydrogen atom or a methyl group. Y ¹ is a single bond, a phenylene or naphthylene group, or a linking group having 1 to 12 carbon atoms containing an ester bond or a lactone ring. Y ² is a single bond or an ester bond. R ¹¹ and R ¹² are acid labile groups. In addition, when the above-mentioned base polymer contains both the repeating unit a1 and the repeating unit a2, R ¹¹ and R ¹² may be the same group or different groups.

Examples of the monomer that gives the repeating unit a1 include the following but are not limited thereto. In the following formula, R ^A and R ^{11 are the} same as described above. [Chemical 48]

Examples of the monomer that gives the repeating unit a2 include the following but are not limited thereto. In the following formula, R ^A and R ^{12 are the} same as described above. [Chem 49]

The acid labile groups represented by R ¹¹ and R ¹² in the repeating units a1 and a2 are, for example, those described in JP-A-2013-80033 and JP-A-2013-83821.

Typically, examples of the acid labile group include those represented by the following formulae (AL-1) to (AL-3). [化50]

In formulas (AL-1) and (AL-2), R ^L1 and R ^L2 are monovalent hydrocarbon groups having 1 to 40 carbon atoms, and may contain hetero atoms such as oxygen atom, sulfur atom, nitrogen atom, and fluorine atom. The monovalent hydrocarbon group may be linear, branched, or cyclic. An alkyl group having 1 to 40 carbon atoms is preferred, and an alkyl group having 1 to 20 carbon atoms is more preferred. In formula (AL-1), a is an integer of 0-10, preferably an integer of 1-5.

In formula (AL-2), R ^L3 and R ^L4 are each independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 20 carbon atoms, and may contain hetero atoms such as an oxygen atom, a sulfur atom, a nitrogen atom, and a fluorine atom. The aforementioned monovalent hydrocarbon group may be any of linear, branched, and cyclic, and it is preferably an alkyl group having 1 to 20 carbon atoms. In addition, any two of R ^L2 , R ^L3 and R ^L4 may be bonded to each other and form a ring with a carbon number of 3 to 20 together with the carbon atom or carbon atom and oxygen atom to which they are bonded. The aforementioned ring is preferably a ring having 4 to 16 carbon atoms, particularly preferably an alicyclic ring.

In the formula (AL-3), R ^L5 , R ^L6 and R ^L7 are each independently a monovalent hydrocarbon group having 1 to 20 carbon atoms, and may contain hetero atoms such as oxygen atom, sulfur atom, nitrogen atom and fluorine atom. The aforementioned monovalent hydrocarbon group may be any of linear, branched, or cyclic, and alkyl groups having 1 to 20 carbon atoms are preferred. In addition, any two of R ^L5 , R ^L6 and R ^L7 may be bonded to each other and form a ring having 3 to 20 carbon atoms together with the carbon atoms to which they are bonded. The aforementioned ring is preferably a ring having 4 to 16 carbon atoms, particularly preferably an alicyclic ring.

The aforementioned base polymer may further contain a repeating unit b containing a phenolic hydroxyl group as an adhesive group. Examples of the monomer to be given to the repeating unit b include the following but are not limited thereto. In the following formula, R ^{A is the} same as described above. [化51]

The aforementioned base polymer may further contain a repeating unit c having a hydroxyl group other than a phenolic hydroxyl group, a carboxyl group, a lactone ring, an ether bond, an ester bond, a carbonyl group, or a cyano group as other adhesive groups. Examples of the monomer that gives the repeating unit c include the following but are not limited thereto. In the following formula, R ^{A is the} same as described above.

[化52]

[化53]

[化54]

[化55]

[化56]

[化57]

[化58]

[化59]

The aforementioned basic polymer may further contain a repeating unit d derived from indene, benzofuran, benzothiophene, vinyl naphthalene, chromone, coumarin, norbornadiene, or these derivatives. Examples of the monomer for giving the repeating unit d include the following but are not limited thereto.

[化60]

The aforementioned base polymer may further contain a repeating unit e derived from styrene, vinyl naphthalene, vinyl anthracene, vinyl pyrene, methylene indane, vinyl pyridine or vinyl carbazole.

The aforementioned base polymer may further contain a repeating unit f derived from an onium salt containing a polymerizable unsaturated bond. Japanese Unexamined Patent Publication No. 2005-84365 contains a sulfonium salt and a gallium salt that generate a polymerizable unsaturated bond of a specific sulfonic acid. Japanese Patent Laid-Open No. 2006-178317 proposes that the sulfonic acid is directly bonded to the salt of the main chain.

Examples of the ideal repeating unit f include a repeating unit represented by the following formula (f1) (hereinafter also referred to as a repeating unit f1), a repeating unit represented by the following formula (f2) (hereinafter also referred to as a repeating unit f2), and the following The repeating unit represented by formula (f3) (hereinafter also referred to as repeating unit f3.). In addition, the repeating units f1 to f3 may be used alone or in combination of two or more. [化61]

In formulas (f1) to (f3), R ^{A is the} same as described above. Z ¹ is a single bond, phenylene, -OZ ¹¹ -, -C(=O)-OZ ¹¹ -or -C(=O)-NH-Z ¹¹ -, Z ¹¹ is an alkane with 1 to 6 carbon atoms It may contain a carbonyl group, an ester bond, an ether bond, or a hydroxyl group, a C2-C6 alkenyl diyl group, or a phenylene group. Z ² is a single ^{bond, -Z 21 -C (= O)} -O -, - Z 21 -O- or ^{-Z 21 -OC (= O) -} , Z 21 alkanediyl group having a carbon number of 1 to 12, It may also contain a carbonyl group, an ester bond or an ether bond. Z ³ is a single bond, methylene, ethylidene, phenylene, fluorinated phenylene, -C(=O)-OZ ³¹ -or -C(=O)-NH-Z ³¹ -, Z ³¹ It is a C1-C6 alkanediyl group, phenylene group, fluorinated phenylene group, trifluoromethyl-substituted phenylene group, or a C2-C6 alkenyl group, and may also contain a carbonyl group, an ester bond , Ether bond or hydroxyl. A is a hydrogen atom or trifluoromethyl.

In formulas (f1) to (f3), R ²¹ to R ²⁸ are each independently a C 1-20 monovalent hydrocarbon group which may also contain a hetero atom. In addition, any two of R ²³ , R ²⁴ and R ²⁵ , or any two of R ²⁶ , R ²⁷ and R ²⁸ may be bonded to each other and form a ring together with the sulfur atom to which they are bonded.

The monovalent hydrocarbon group may be any of linear, branched, and cyclic. Specific examples thereof include the same as those described above for R ^a1 to R ^a3 in formula (Aa). Examples of the cations in the formulas (f2) and (f3) include the same as the aforementioned cations represented by the formula (Aa).

In formula (f1), M ^{-is a} non-nucleophilic relative ion. Examples of the non-nucleophilic relative ion include halide ions such as chloride ions and bromide ions, trifluoromethanesulfonate ions, 1,1,1-trifluoroethanesulfonate ions, and nonafluorobutane sulfonate ions. Fluoroalkylsulfonate ion, tosylate ion, benzenesulfonate ion, 4-fluorobenzenesulfonate ion, 1,2,3,4,5-pentafluorobenzenesulfonate ion, etc. Sulfonate ions, butanesulfonate ions and other alkylsulfonate ions, bis(trifluoromethylsulfonyl) amide imide ion, bis(perfluoroethylsulfonyl amide) amide imide ion, bis(perfluoro Butylsulfonyl) amide imide ions and other imidate ions, ginseng (trifluoromethyl sulfonyl) methide ions, ginseng (perfluoroethyl sulfonyl) methide ions and other methylate ions .

Examples of the aforementioned non-nucleophilic relative ion include sulfonic acid ions substituted with a fluorine atom at the α position represented by the following formula (K-1), and sulfonic acid substituted with a fluorine atom at the α and β positions represented by the following formula (K-2) Ions etc. [化62]

In formula (K-1), R ⁵¹ is a hydrogen atom, a C 1-20 alkyl group, a C 2-20 alkenyl group, or a C 6-20 aryl group, and may also contain an ether bond or an ester bond , Carbonyl, lactone ring or fluorine atom. The aforementioned alkyl group and alkenyl group may be any of linear, branched, and cyclic.

In the formula (K-2), R ⁵² is a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, an acetyl group, an alkenyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aryloxy group, or May contain ether bonds, ester bonds, carbonyl groups or lactone rings. The aforementioned alkyl group and alkenyl group may be any of linear, branched, and cyclic.

Examples of the monomer that gives the repeating unit f1 include the following but are not limited thereto. In the following formula, R ^A and M ^{-are the} same as described above. [化63]

Examples of the monomer that gives the repeating unit f2 include the following but are not limited thereto. In the following formula, R ^{A is the} same as described above. [化64]

[化65]

[化66]

[化67]

[化68]

Examples of the monomer that gives the repeating unit f3 include the following but are not limited thereto. In the following formula, R ^{A is the} same as described above. [化69]

[化70]

By bonding the acid generator to the polymer main chain, the acid diffusion can be reduced and the resolution can be prevented from decreasing due to the blurring of the acid diffusion. In addition, by uniformly dispersing the acid generator, the edge roughness can be improved. In addition, when the base polymer containing the repeating unit f is used, the blending of the acid generator described later can be omitted.

For the basic polymer used for the positive photoresist material, a repeating unit a1 or a2 containing an acid labile group is required. In this case, the content ratio of the repeating units a1, a2, b, c, d, e, and f is 0≦a1<1.0, 0≦a2<1.0, 0<a1+a2<1.0, 0≦b≦0.9, 0≦c ≦0.9, 0≦d≦0.8, 0≦e≦0.8, and 0≦f≦0.5 are ideal, 0≦a1≦0.9, 0≦a2≦0.9, 0.1≦a1+a2≦0.9, 0≦b≦0.8, 0≦ c≦0.8, 0≦d≦0.7, 0≦e≦0.7, and 0≦f≦0.4, 0≦a1≦0.8, 0≦a2≦0.8, 0.1≦a1+a2≦0.8, 0≦b≦0.75, 0 ≦c≦0.75, 0≦d≦0.6, 0≦e≦0.6, and 0≦f≦0.3 are more ideal. In addition, when the repeating unit f is at least one selected from the repeating units f1 to f3, f = f1 + f2 + f3. In addition, a1+a2+b+c+d+e+f=1.0.

On the other hand, the base polymer used for negative photoresist materials does not necessarily have to have acid-labile groups. Examples of such a base polymer include a repeating unit b and optionally, repeating units c, d, e, and/or f. The content ratio of the repeating units is 0<b≦1.0, 0≦c≦0.9, 0≦d≦0.8, 0≦e≦0.8, and 0≦f≦0.5, 0.2≦b≦1.0, 0≦c ≦0.8, 0≦d≦0.7, 0≦e≦0.7, and 0≦f≦0.4, 0.3≦b≦1.0, 0≦c≦0.75, 0≦d≦0.6, 0≦e≦0.6, and 0 ≦f≦0.3 is more ideal. In addition, when the repeating unit f is at least one selected from the repeating units f1 to f3, f = f1 + f2 + f3. In addition, b + c + d + e + f = 1.0.

In order to synthesize the aforementioned base polymer, for example, the monomer given to the aforementioned repeating unit may be added to an organic solvent, a radical polymerization initiator is added, and heat polymerization is performed.

Examples of organic solvents used in the polymerization include toluene, benzene, tetrahydrofuran, diethyl ether, and dioxane. Examples of the polymerization initiator include 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis(2,4-dimethylvaleronitrile), and 2,2-azobis( 2-methylpropionic acid) dimethyl, benzoyl peroxide, laurel peroxide, etc. The temperature during the polymerization is preferably 50 to 80°C. The reaction time is preferably 2 to 100 hours, and more preferably 5 to 20 hours.

When copolymerizing a monomer containing a hydroxyl group, the hydroxyl group can be replaced with an acetal group such as an ethoxyethoxy group easily deprotected by an acid during the polymerization, and after the polymerization is deprotected with a weak acid and water, or It is first substituted with acetyl, methyl acetyl, trimethyl acetyl, etc., and then undergoes alkaline hydrolysis after polymerization.

When copolymerizing hydroxystyrene and hydroxyvinylnaphthalene, instead of using hydroxystyrene or hydroxyvinylnaphthalene, it is possible to use acetoxystyrene and ethoxyvinylnaphthalene. Acetyloxy is deprotected and becomes hydroxystyrene and hydroxyvinylnaphthalene.

Ammonia water, triethylamine, etc. can be used as the alkali during alkali hydrolysis. The reaction temperature is preferably -20 to 100°C, and more preferably 0 to 60°C. The reaction time is preferably 0.2 to 100 hours, and more preferably 0.5 to 20 hours.

When the aforementioned base polymer is gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent, the polystyrene-equivalent weight average molecular weight (Mw) is preferably 1,000 to 500,000, and more preferably 2,000 to 30,000. If the Mw is too small, the heat resistance of the photoresist material will deteriorate, and if it is too large, the alkali solubility will decrease, and it is easy to cause the tailing phenomenon after pattern formation.

In addition, when the molecular weight distribution (Mw/Mn) of the base polymer is wide, there is a possibility that foreign substances may appear on the pattern or the shape of the pattern may deteriorate after exposure due to the presence of low molecular weight and high molecular weight polymers. As the pattern pattern becomes finer, the influence of Mw and Mw/Mn tends to increase. Therefore, in order to obtain a photoresist material suitable for fine pattern size, the Mw/Mn of the aforementioned base polymer is 1.0 to 2.0, especially 1.0 to 1.5. Narrow dispersion is better.

The aforementioned base polymer may contain two or more kinds of polymers having different composition ratios, Mw, and Mw/Mn. In addition, as long as the effect of the present invention is not impaired, the aforementioned base polymer may contain a polymer different from the aforementioned polymer, but it is preferably not included.

[Acid generator] The photoresist of the present invention may further contain an acid generator (hereinafter also referred to as an additive acid generator) in order to function as a chemically amplified positive photoresist or a chemically amplified negative photoresist. As a result, it will become a higher-resistance photoresist material, and each characteristic will be more excellent, making it extremely useful. In addition, when the base polymer contains the repeating unit f, that is, when the base polymer contains the acid generator, the additive acid generator may not be included.

The aforementioned additive acid generator is, for example, a compound (photoacid generator) that generates an acid by sensing active light or radiation. The photo-acid generator may be any compound that generates an acid by irradiation with high-energy rays, and is preferably a sulfonic acid, imidate, or methylated acid. The ideal photo-acid generators include ramium salts, iodonium salts, sulfonyl diazomethane, N-sulfonyloxyimide, and oxime-O-sulfonate acid generators. Specific examples of the photoacid generator include those described in paragraphs [0122] to [0142] of Japanese Patent Laid-Open No. 2008-111103.

In addition, the photoacid generator is preferably represented by the following formula (1). [化71]

In formula (1), R ¹⁰¹ , R ¹⁰² and R ¹⁰³ are each independently a C 1-20 monovalent hydrocarbon group which may also contain a hetero atom. In addition, any two of R ¹⁰¹ , R ¹⁰² and R ¹⁰³ may be bonded to each other and form a ring together with the sulfur atom to which they are bonded. The aforementioned monovalent hydrocarbon group may be any of linear, branched, and cyclic, and specific examples thereof may be the same as those described in the description of R ^a1 to R ^a3 in formula (Aa).

As the cation of the manganese salt represented by the formula (1), there can be mentioned the same as the manganese cation represented by the formula (Aa) and the foregoing.

Formula (1), X ^- ~ in the (1D) an anion selected from the following formulas (1A). [化72]

In formula (1A), R ^fa is a fluorine atom, or a C1-C40 monovalent hydrocarbon group which may contain a hetero atom. The aforementioned monovalent hydrocarbon group may be any of linear, branched, and cyclic, and specific examples thereof may be the same as those described in the description of R ¹⁰⁵ described later.

The anion represented by formula (1A) is preferably represented by the following formula (1A'). [化73]

In formula (1A'), R ¹⁰⁴ is a hydrogen atom or a trifluoromethyl group, preferably a trifluoromethyl group. R ¹⁰⁵ is a monovalent hydrocarbon group having 1 to 38 carbon atoms which may contain a hetero atom. The aforementioned hetero atom is preferably an oxygen atom, a nitrogen atom, a sulfur atom, a halogen atom, etc., and an oxygen atom is more ideal. In terms of the aforementioned monovalent hydrocarbon group, in view of obtaining a high resolution in the formation of a fine pattern, a carbon number of 6 to 30 is particularly preferable. The aforementioned monovalent hydrocarbon group may be any of linear, branched, and cyclic, and specific examples thereof include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, and second butyl. , Tert-butyl, pentyl, neopentyl, cyclopentyl, hexyl, heptyl, 2-ethylhexyl, nonyl, undecyl, tridecyl, fifteen, seventeen, icosyl Equivalent linear or branched alkyl groups; cyclohexyl, 1-adamantyl, 2-adamantyl, 1-adamantylmethyl, norbornyl, norbornylmethyl, tricyclodecyl, tetra Monovalent saturated cyclic aliphatic hydrocarbon groups such as cyclododecyl, tetracyclododecylmethyl, and dicyclohexylmethyl; monovalent unsaturated aliphatic hydrocarbon groups such as allyl and 3-cyclohexenyl; benzyl, Aralkyl groups such as diphenylmethyl. In addition, examples of the monovalent hydrocarbon group containing a hetero atom include tetrahydrofuranyl, methoxymethyl, ethoxymethyl, methylthiomethyl, acetamidomethyl, trifluoroethyl, (2- (Methoxyethoxy) methyl, acetoxymethyl, 2-carboxy-1-cyclohexyl, 2-oxopropyl, 4-oxo-1-adamantyl, 3-oxo Base cyclohexyl and so on. In addition, a part of the hydrogen atoms of these groups may also be substituted with heteroatoms containing oxygen atoms, sulfur atoms, nitrogen atoms, halogen atoms, or a part of the carbon atoms of these groups may also be replaced with oxygen atoms, sulfur Groups of heteroatoms such as atoms and nitrogen atoms, as a result, they may also contain hydroxyl groups, cyano groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sultone rings, carboxylic anhydrides, Haloalkyl, etc.

For the synthesis of samium salts containing anions represented by formula (1A'), see Japanese Patent Laid-Open No. 2007-145797, Japanese Patent Laid-Open No. 2008-106045, Japanese Patent Laid-Open No. 2009-7327, Japanese Patent Laid-Open No. 2009- Bulletin No. 258695, etc. In addition, JP-A No. 2010-215608, JP-A No. 2012-41320, JP-A No. 2012-106986, and JP-A No. 2012-153644 are also suitable for use.

Examples of the anions represented by formula (1A) include the following but are not limited thereto. In the following formula, Ac is acetyl. [化74]

[化75]

[化76]

[化77]

In formula (1B), R ^fb1 and R ^fb2 are each independently a fluorine atom or a C 1-40 monovalent hydrocarbon group which may contain a hetero atom. The aforementioned monovalent hydrocarbon group may be any of linear, branched, and cyclic, and specific examples thereof may be the same as those described in the description of R ¹⁰⁵ above. R ^fb1 and R ^{fb2 are} preferably a fluorine atom or a linear fluorinated alkyl group having 1 to 4 carbon atoms. In addition, R ^fb1 and R ^fb2 can also be bonded to each other and form a ring together with the group to which they are bonded (-CF ₂ -SO ₂ -N ^-- SO ₂ -CF ₂ -). In this case, R ^fb1 and R The groups obtained by ^{fb2 being} bonded to each other are preferably fluorinated ethyl or propyl fluoride.

In formula (1C), R ^fc1 , R ^fc2 and R ^fc3 are each independently a fluorine atom or a C 1-40 monovalent hydrocarbon group which may contain a hetero atom. The aforementioned monovalent hydrocarbon group may be any of linear, branched, and cyclic, and specific examples thereof may be the same as those described in the description of R ¹⁰⁵ above. R ^fc1 , R ^fc2 and R ^{fc3 are} preferably a fluorine atom or a linear fluorinated alkyl group having 1 to 4 carbon atoms. In addition, R ^fc1 and R ^fc2 can also be bonded to each other and form a ring together with the group to which they are bonded (-CF ₂ -SO ₂ -C ^-- SO ₂ -CF ₂ -). In this case, R ^fc1 and R The group obtained by ^fc2 bonding to each other is preferably fluorinated ethyl or propyl fluoride.

In formula (1D), R ^fd is a C1- ^C40 monovalent hydrocarbon group which may also contain a hetero atom. The aforementioned monovalent hydrocarbon group may be any of linear, branched, and cyclic, and specific examples thereof may be the same as those described in the description of R ¹⁰⁵ above.

Regarding the synthesis of the monium salt containing the anion represented by the formula (1D), see Japanese Patent Laid-Open No. 2010-215608 and Japanese Patent Laid-Open No. 2014-133723 for details.

The anions represented by the formula (1D) may be exemplified below but not limited thereto. [Chemical 78]

In addition, the photoacid generator containing the anion represented by the formula (1D) has no fluorine at the α position of the sulfo group, but there are two trifluoromethyl groups at the β position, so it has the purpose of cutting off acid instability in the photoresist polymer. The full acidity of the base. Therefore, it can be used as a photoacid generator.

In addition, the photoacid generator is preferably represented by the following formula (2). [化79]

In formula (2), R ²⁰¹ and R ²⁰² are each independently a C 1-30 monovalent hydrocarbon group which may also contain a hetero atom. R ²⁰³ is a divalent hydrocarbon group having 1 to 30 carbon atoms which may also contain heteroatoms. In addition, any two of R ²⁰¹ , R ²⁰² and R ²⁰³ may be bonded to each other and form a ring together with the sulfur atom to which they are bonded. L ^A is a single bond, an ether bond, or a C1-C20 divalent hydrocarbon group which may contain a hetero atom. X ^A , X ^B , X ^C and X ^D are each independently a hydrogen atom, a fluorine atom or a trifluoromethyl group. However, at least one of X ^A , X ^B , X ^C and X ^D is a fluorine atom or a trifluoromethyl group. k is an integer from 0 to 3.

The aforementioned monovalent hydrocarbon group may be any of linear, branched, and cyclic, and specific examples thereof include methyl, ethyl, propyl, isopropyl, n-butyl, second butyl, and third Straight-chain or branched alkyl groups such as butyl, n-pentyl, third-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, 2-ethylhexyl; cyclopentyl, cyclohexyl, Cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornyl, oxanorcinyl, tricyclo[5.2.1.0 ^{2 , 6} ] Decyl, adamantyl and other monovalent saturated cyclic hydrocarbon groups; phenyl, naphthyl, anthracenyl and other aryl groups. In addition, part of the hydrogen atoms of these groups may also be replaced with hetero atoms such as oxygen atom, sulfur atom, nitrogen atom, halogen atom, etc., and part of the carbon atoms of these groups may also be replaced with oxygen atom, sulfur atom, nitrogen atom As a result, it may contain hydroxyl, cyano, carbonyl, ether bond, ester bond, sulfonate bond, carbonate bond, lactone ring, sultone ring, carboxylic anhydride, haloalkyl group, etc. .

The aforementioned divalent hydrocarbon group may be any of linear, branched, and cyclic, and specific examples thereof include methylene, ethylidene, propane-1,3-diyl, butane-1,4- Diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, nonane-1,9- Diyl, decane-1,10-diyl, undecane-1,11-diyl, dodecane-1,12-diyl, tridecane-1,13-diyl, tetradecane- 1,14-diyl, pentadecane-1,15-diyl, hexadecane-1,16-diyl, heptadecane-1,17-diyl and other straight-chain or branched alkanediyl groups ; Divalent saturated cyclic hydrocarbon groups such as cyclopentanediyl, cyclohexanediyl, norbornanediyl, adamantanediyl; unsaturated cyclic divalent hydrocarbon groups such as phenylene and naphthyl. In addition, part of the hydrogen atoms of these groups may also be substituted with alkyl groups such as methyl, ethyl, propyl, n-butyl, and tert-butyl groups, and part of the hydrogen atoms of these groups may also be substituted with oxygen atoms , Heteroatoms such as sulfur atoms, nitrogen atoms, halogen atoms, or a part of the carbon atoms of these groups can also be replaced with heteroatoms containing oxygen atoms, sulfur atoms, nitrogen atoms, etc., as a result, they can also contain hydroxyl groups, Cyano, carbonyl, ether bond, ester bond, sulfonate bond, carbonate bond, lactone ring, sultone ring, carboxylic anhydride, haloalkyl group, etc. The aforementioned hetero atom is preferably an oxygen atom.

The photoacid generator represented by the formula (2) is preferably represented by the following formula (2'). [Chem 80]

In formula (2'), L ^{A is the} same as described above. R is a hydrogen atom or a trifluoromethyl group, preferably a trifluoromethyl group. R ³⁰¹ , R ³⁰² and R ³⁰³ are each independently a hydrogen atom or a C 1-20 monovalent hydrocarbon group which may contain a hetero atom. The aforementioned monovalent hydrocarbon group may be any of linear, branched, and cyclic, and specific examples thereof may be the same as those described in the description of R ¹⁰⁵ above. x and y are each independently an integer of 0 to 5, and z is an integer of 0 to 4.

The photoacid generator represented by the formula (2) may be exemplified below but not limited thereto. In the following formula, R is the same as described above, and Me is methyl. [化81]

[化82]

[Chemical 83]

Among the aforementioned photo-acid generators, those containing anions represented by formula (1A') or (1D) have a small acid diffusion and excellent solubility in photoresist solvents, which is particularly desirable. In addition, those containing the anion represented by formula (2') have very little acid diffusion and are particularly desirable.

In addition, as for the aforementioned photoacid generator, a samium salt or a gallium salt having an anion containing an iodine atom can also be used. Examples of such a salt include amide salts and iodonium salts of fluorinated sulfonic acid containing benzyloxy iodide represented by the following formula (3-1) or (3-2). [化84]

In formulas (3-1) and (3-2), R ⁴⁰¹ is a hydrogen atom, a hydroxyl group, a carboxyl group, a nitro group, a cyano group, a fluorine atom, a chlorine atom, a bromine atom, an amine group, or may contain a fluorine atom, chlorine Atom, bromine atom, hydroxyl, amine or alkoxy, C 1-20 alkyl, C 1-20 alkoxy, C 2-20 alkoxycarbonyl, C 2-20 Acyloxy or alkylsulfonyloxy having 1 to 4 carbon atoms, or -NR ⁴⁰⁷ -C(=O)-R ⁴⁰⁸ or -NR ⁴⁰⁷ -C(=O)-OR ⁴⁰⁸ , R ⁴⁰⁷ is a hydrogen atom, Or it may also contain a halogen atom, a hydroxyl group, an alkoxy group, an acetyl group, or an alkoxy group, a C 1-6 alkyl group, R ⁴⁰⁸ is a C 1-16 alkyl group, a C 2-16 alkenyl group, Or an aryl group having 6 to 12 carbon atoms may also contain a halogen atom, a hydroxyl group, an alkoxy group, an acyl group or an acyloxy group.

X ¹¹ , when r is 1, it is a single bond or a C 1-20 divalent linking group, when r is 2 or 3, it is a C 1-20 trivalent or tetravalent linking group, the linking group may also be Contains oxygen, sulfur or nitrogen atoms.

Rf ¹¹ to Rf ¹⁴ are each independently a hydrogen atom, a fluorine atom or a trifluoromethyl group, but at least one of these is a fluorine atom or a trifluoromethyl group. In addition, Rf ¹¹ and Rf ¹² may be combined to form a carbonyl group.

R ⁴⁰² , R ⁴⁰³ , R ⁴⁰⁴ , R ⁴⁰⁵ and R ⁴⁰⁶ are each independently a C 1-20 monovalent hydrocarbon group which may also contain a hetero atom. Also, any two of R ⁴⁰² , R ⁴⁰³ and R ⁴⁰⁴ may be bonded to each other and form a ring together with the sulfur atom to which they are bonded. The aforementioned monovalent hydrocarbon group may be any of linear, branched, or cyclic, and specific examples thereof may be the same as the description of R ^a1 to R ^a3 in formula (Aa), and the aforementioned ones are the same.

r is an integer from 1 to 3. s is an integer from 1 to 5. t is an integer from 0 to 3.

In addition, the alkyl group, alkoxy group, alkoxycarbonyl group, acetyloxy group, alkylsulfonyloxy group, alkenyl group, and acetyl group may be any of linear, branched, and cyclic.

In addition, as for the osmium salt or the epimium salt having an anion containing an iodine atom, the osmium salt or the epimium salt of a fluorinated sulfonic acid containing an iodinated benzene ring represented by the following formula (3-3) or (3-4) can also be cited . [化85]

In formulas (3-3) and (3-4), R ^{411 is} each independently a hydroxyl group, an alkyl group or an alkoxy group having 1 to 20 carbon atoms, an acyl group or an alkoxy group having 2 to 20 carbon atoms, or a fluorine atom , Chlorine atom, bromine atom, amine group, or alkoxycarbonyl substituted amine group.

R ^{412 is} each independently a single bond or an alkylene group having 1 to 4 carbon atoms. R ⁴¹³ , when u is 1, it is a single bond or a C 1-20 divalent linking group, when u is 2 or 3, it is a C 1-20 trivalent or tetravalent linking group, the linking group may also be Contains oxygen, sulfur or nitrogen atoms.

Rf ²¹ to Rf ²⁴ are each independently a hydrogen atom, a fluorine atom or a trifluoromethyl group, but at least one of them is a fluorine atom or a trifluoromethyl group. In addition, Rf ²¹ and Rf ²² may be combined to form a carbonyl group.

R ⁴¹⁴ , R ⁴¹⁵ , R ⁴¹⁶ , R ⁴¹⁷ and R ⁴¹⁸ are each independently a C 1-20 monovalent hydrocarbon group which may also contain a hetero atom. In addition, any two of R ⁴¹⁴ , R ⁴¹⁵ and R ⁴¹⁶ may be bonded to each other and form a ring together with the sulfur atom to which they are bonded. The aforementioned monovalent hydrocarbon group may be any of linear, branched, or cyclic, and specific examples thereof may be the same as the description of R ^a1 to R ^a3 in formula (Aa), and the aforementioned ones are the same.

u is an integer from 1 to 3. v is an integer from 1 to 5. w is an integer from 0 to 3.

The alkyl group, alkoxy group, acetyl group, acetyl group, and alkenyl group may be any of linear, branched, and cyclic.

Examples of the cations of the samarium salt represented by the formulas (3-1) and (3-3) include the same as those of the samarium cation represented by the formula (Aa). In addition, as the cation of the antimony salt represented by the formulas (3-2) and (3-4), the cation of the antimony salt represented by the formula (Ab) can be exemplified, and the same as the foregoing.

Examples of the anion part of the onium salt represented by formulas (3-1) to (3-4) include the following but are not limited thereto. [化86]

[化87]

[化88]

[化89]

[化90]

[化91]

[化92]

[化93]

[化94]

[化95]

[化96]

[化97]

[化98]

[Chem 99]

[化100]

[化101]

[化102]

[化103]

[化104]

[化105]

[化106]

[化107]

In addition, as for the aforementioned photoacid generator, a monium salt or a gallium salt having an anion containing a bromine atom can also be used. Examples of the anion containing a bromine atom include those in formulas (3-1) to (3-4) in which iodine atoms are replaced with bromine atoms. In addition, specific examples thereof include those in which the iodine atom in the iodine atom-containing anion is replaced with a bromine atom.

When the photoresist material of the present invention contains the aforementioned additive acid generator, its content is preferably 0.1 to 50 parts by mass relative to 100 parts by mass of the base polymer, and more preferably 1 to 40 parts by mass.

[Other ingredients] In addition to the aforementioned components, by combining and blending organic solvents, surfactants, dissolution inhibitors, cross-linking agents, etc. according to the purpose, a positive photoresist material and a negative photoresist material are formed. The substance accelerates the dissolution rate of the developer due to the catalyst reaction, so it can become a very high-sensitivity positive photoresist material and negative photoresist material. In this case, the photoresist film has high dissolution contrast and resolution, has exposure margin, excellent handling adaptability, and the pattern shape after exposure is good, and in particular, it can suppress acid diffusion, so the difference in density and density is small, so it is practical High, very effective as a photoresist for ultra-LSI.

Examples of the aforementioned organic solvents include ketones such as cyclohexanone, cyclopentanone, and methyl-2-n-pentyl ketone described in paragraphs [0144] to [0145] of JP-A-2008-111103. 3 -Methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, diacetone alcohol and other alcohols, propylene glycol Monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, diethylene glycol dimethyl ether and other ethers, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate Ester, ethyl lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, third butyl acetate, third butyl propionate, propylene glycol mono Esters such as tertiary butyl ether acetate, lactones such as γ-butyrolactone, and mixed solvents thereof. These solvents can be used alone or in combination of two or more.

In the photoresist material of the present invention, the content of the organic solvent is preferably 100 to 10,000 parts by mass relative to 100 parts by mass of the base polymer, and more preferably 200 to 8,000 parts by mass.

Examples of the aforementioned surfactants include those described in paragraphs [0165] to [0166] of Japanese Patent Laid-Open No. 2008-111103. By adding a surfactant, the coatability of the photoresist material can be further improved or controlled. The surfactant can be used alone or in combination of two or more. In the photoresist material of the present invention, the content of the surfactant is preferably 0.0001 to 10 parts by mass relative to 100 parts by mass of the base polymer.

In the case of a positive photoresist material, by blending a dissolution inhibitor, the difference between the dissolution rate of the exposed part and the unexposed part can be increased, and the resolution can be improved. On the other hand, in the case of a negative-type photoresist, a negative pattern can be obtained by adding a cross-linking agent to reduce the dissolution rate of the exposed portion.

Examples of the dissolution inhibitor include a molecular weight of preferably 100 to 1,000, more preferably 150 to 800, and a compound containing two or more phenolic hydroxyl groups in the molecule. In general, the hydrogen atom of the carboxyl group of a compound substituted with an acid labile group or a compound containing a carboxyl group in the ratio of 0 to 100 mol% is replaced with an acid at an average ratio of 50 to 100 mol% as a whole Unstable compounds. Specific examples include compounds in which bisphenol A, phenol, phenol phenolphthalein, cresol novolac, naphthalene carboxylic acid, adamantane carboxylic acid, hydroxyl group of cholic acid, and hydrogen atom of carboxyl group are replaced with acid labile groups, for example : It is described in paragraphs [0155] to [0178] of Japanese Patent Laid-Open No. 2008-122932.

When the photoresist material of the present invention is a positive type photoresist material, the content of the dissolution inhibitor is preferably 0-50 parts by mass relative to 100 parts by mass of the base polymer, and more preferably 5-40 parts by mass. The aforementioned dissolution inhibitor may be used alone or in combination of two or more.

Examples of the aforementioned crosslinking agent include epoxy compounds substituted with at least one group selected from the group consisting of methylol, alkoxymethyl, and acetylmethyl, melamine compounds, guanamine compounds, and glycoluril compounds. Or urea compounds, isocyanate compounds, azide compounds, compounds containing double bonds such as allyl ether groups, etc. They can be used as additives, or they can be introduced into the polymer side chain as a suspension group. In addition, hydroxyl-containing compounds can also be used as crosslinking agents. The crosslinking agent may be used alone or in combination of two or more.

Examples of the aforementioned epoxy compounds include ginseng (2,3-epoxypropyl) isocyanurate, trimethylolmethane triglycidyl ether, trimethylolpropane triglycidyl ether, and Hydroxyethylethane triglycidyl ether, etc.

Examples of the aforementioned melamine compounds include compounds obtained by methoxymethylation of 1-6 methylol groups of hexamethylol melamine, hexamethoxymethyl melamine, and hexamethylol melamine, or mixtures thereof. Compounds or mixtures of 1 to 6 hydroxymethyl groups of hexamethoxyethyl melamine, hexaacetoxymethyl melamine, and hexamethylol melamine by acyloxymethylation.

Examples of guanamine compounds include compounds obtained by methoxymethylation of 1 to 4 hydroxymethyl groups of tetramethylolguanamine, tetramethoxymethylguanamine, and tetramethylolguanidine. Or a mixture thereof, a compound obtained by methoxymethylation of 1 to 4 hydroxymethyl groups of tetramethoxyethylguanamine, tetraoxymethylguanamine, tetramethylolguanidine, or a mixture thereof.

Examples of the glycoluril compound include 1 to 4 hydroxymethyl methoxy groups of tetramethylol glycoluril, tetramethoxy glycoluril, tetramethoxymethyl glycoluril, and tetramethylol glycoluril. Compounds obtained by methylation or mixtures thereof, compounds obtained by methylation of 1 to 4 hydroxymethyl groups of tetramethylol glycoluril by acyloxymethylation or mixtures thereof, etc. Examples of urea compounds include compounds obtained by methoxymethylation of 1 to 4 methylol groups of tetramethylol urea, tetramethoxymethyl urea, and tetramethylol urea, or mixtures thereof. Tetramethoxyethyl urea, etc.

Examples of isocyanate compounds include tolyl diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, and cyclohexane diisocyanate.

Examples of the azide compound include 1,1'-biphenyl-4,4'-bisazide, 4,4'-matte methylbisazide, and 4,4'-oxybisazide Nitrides, etc.

Examples of the compound containing an allyl ether group include ethylene glycol divinyl ether, triethylene glycol divinyl ether, 1,2-propylene glycol divinyl ether, 1,4-butanediol divinyl ether, and tetramethylene divinyl ether. Alcohol divinyl ether, neopentyl glycol divinyl ether, trimethylolpropane trivinyl ether, hexanediol divinyl ether, 1,4-cyclohexanediol divinyl ether, neopentyl tetravinyl ether , Neopentaerythritol tetraethylene ether, sorbitol tetraethylene ether, sorbitol pentaethylene ether, trimethylolpropane triethylene ether, etc.

When the photoresist material of the present invention is a negative photoresist material, the content of the crosslinking agent is preferably 0.1 to 50 parts by mass relative to 100 parts by mass of the base polymer, and more preferably 1 to 40 parts by mass.

The photoresist of the present invention may be blended with a quencher other than the sulfonamide salt containing sulfonamide containing benzene ring iodide (hereinafter referred to as other quenchers). The aforementioned quencher may be a conventional basic compound. Examples of the conventional basic compounds include 1st, 2nd, and 3rd aliphatic amines, mixed amines, aromatic amines, heterocyclic amines, nitrogen-containing compounds with carboxyl groups, and sulfonamides. Nitrogen-containing compounds, hydroxyl-containing nitrogen-containing compounds, hydroxyl-containing nitrogen-containing compounds, alcoholic nitrogen-containing compounds, amides, amides, carbamates, etc. In particular, the first, second, and third amine compounds described in paragraphs [0146] to [0164] of Japanese Patent Laid-Open No. 2008-111103, especially have a hydroxyl group, an ether bond, an ester bond, a lactone ring, a cyano group, and a sulfonic acid Compounds with an ester bond or compounds having a urethane group described in Japanese Patent No. 3790649 are preferred. By adding such an alkaline compound, for example, the diffusion rate of acid in the photoresist film can be more suppressed, or the shape can be corrected.

In addition, as other quenching agents, onium salts such as osmium salts, iodonium salts, and ammonium salts of sulfonic acids and carboxylic acids that are not fluorinated at the α position described in Japanese Patent Laid-Open No. 2008-158339 can be cited. The fluorinated α-position sulfonic acid, imidic acid or methylated acid is necessary for deprotecting the acid-labile group of the carboxylic acid ester. By salt exchange with the non-fluorinated α-position onium salt, it will be released Unfluorinated sulfonic acid or carboxylic acid in the α position. Sulfonic acids and carboxylic acids that are not fluorinated at the alpha position will not play a deprotection reaction, so they act as quenchers.

Examples of other quenchers include the polymer-type quenchers described in Japanese Patent Laid-Open No. 2008-239918. It improves the rectangularity of the patterned photoresist by aligning the photoresist surface after coating. The polymer type quencher has the effect of preventing the film loss of the pattern and the rounding of the top of the pattern when the protective film for infiltration exposure is used.

In the photoresist material of the present invention, the content of other quenching agents is preferably 0 to 5 parts by mass relative to 100 parts by mass of the base polymer, and more preferably 0 to 4 parts by mass. The quencher can be used alone or in combination of two or more.

The photoresist material of the present invention may also be blended with a water repellent enhancer to make the water repellent surface of the photoresist surface after spin coating better. As the aforementioned water repellent enhancer, wetting lithography without top coating can be used. The aforementioned water repellent enhancer is preferably a polymer compound containing a fluorinated alkyl group, a polymer compound containing a specific structure of 1,1,1,3,3,3-hexafluoro-2-propanol residue, etc., Illustrators of Japanese Patent Laid-Open No. 2007-297590 and Japanese Patent Laid-Open No. 2008-111103 are more preferable. The aforementioned water repellent enhancer needs to be dissolved in an organic solvent developer. The aforementioned specificity is that the water repellent enhancer with 1,1,1,3,3,3-hexafluoro-2-propanol residue has good solubility in the developer. As for the water repellent enhancer, the polymer compound containing a repeating unit containing an amine group and an amine salt has a high effect of preventing the acid from evaporating in the PEB and preventing the poor opening of the hole pattern after development. The water repellent enhancer may be used alone or in combination of two or more. In the photoresist material of the present invention, the content of the water repellent enhancer is preferably 0-20 parts by mass relative to 100 parts by mass of the base polymer, and more preferably 0.5-10 parts by mass.

The photoresist material of the present invention may also be blended with acetylene alcohols. Examples of the acetylene alcohols include those described in paragraphs [0179] to [0182] of JP-A-2008-122932. In the photoresist material of the present invention, the content of acetylene alcohols is preferably 0 to 5 parts by mass relative to 100 parts by mass of the base polymer.

[Pattern Forming Method] When the photoresist material of the present invention is used in the manufacture of various integrated circuits, the well-known lithography technology can be used.

For example, the photoresist material of the present invention is applied to a substrate (Si, SiO ₂ , SiN, SiN, SiO ₂ , SiN, etc.) by an appropriate coating method such as spin coating, roll coating, flow coating, dip coating, spray coating, blade coating, etc. SiON, TiN, WSi, BPSG, SOG, organic anti-reflective film, etc.) or substrates for the manufacture of mask circuits (Cr, CrO, CrON, MoSi ₂ , SiO ₂ etc.), the coating thickness shall be 0.01～2.0μm . This is preferably pre-baked on a hot plate under conditions of 60 to 150° C. for 10 seconds to 30 minutes, and more preferably under conditions of 80 to 120° C. for 30 seconds to 20 minutes. Secondly, high-energy rays such as ultraviolet, far ultraviolet, EB, EUV, X-ray, soft X-ray, excimer laser, γ-ray, synchrotron radiation, etc. pass through a predetermined mask or a pattern for direct exposure purposes. It is preferable that the exposure amount is about 1 to 200 mJ/cm ² , especially about 10 to 100 mJ/cm ² , or about 0.1 to 100 μC/cm ² , especially about 0.5 to 50 μC/cm ² . Then, PEB is preferably performed on the hot plate at 60 to 150° C. for 10 seconds to 30 minutes, more preferably at 80 to 120° C. for 30 seconds to 20 minutes.

PEB may or may not be performed. In particular, in the case where the anion containing the repeating unit f2 or f3 is bound to the PAG polymer, sulfonic acid is generated due to exposure, and the alkali solubility is improved. Therefore, even if PEB is not performed, the exposed portion will still be dissolved in alkali. If PEB is not performed, blurring of the image due to acid diffusion will be eliminated, and a finer pattern formation can be expected than when PEB is performed.

When PEB is not carried out, no deprotection reaction due to acid occurs, so the photoresist material of the present invention functions as a non-chemically amplified photoresist material. In this case, the dissolution contrast is low, so that after development, film loss of the pattern and residual film at the pitch portion will occur. For non-chemically amplified photoresist materials, how to make the dissolution contrast better becomes the key point.

When the anion containing the aforementioned repeating unit f2 or f3 binds to the PAG polymer, α-fluorosulfonic acid is generated due to exposure, so the solubility in the alkaline developer solution is improved, but by adding an onium salt that is not fluorinated at the α position, and It undergoes salt exchange, thereby inhibiting the production of α-fluorosulfonic acid. In addition, when the exposure amount is increased, the onium salt of sulfonic acid or carboxylic acid that is not fluorinated at the α position is decomposed, so that alkali solubility is improved. That is, the dissolution inhibiting property is improved in the region with a small exposure amount, and the dissolution promoting property is improved in the region with a large exposure amount, thereby improving the contrast. The ion exchange reaction is fast, and it is performed at room temperature, so PEB is not necessary. The onium salt represented by formula (A) is also a weaker acid salt than α-fluorosulfonic acid, and undergoes the same ion exchange, so the contrast is higher than when PEB is not performed.

Furthermore, by using 0.1 to 10% by mass, preferably 2 to 5% by mass, tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide (TEAH), tetrapropylammonium hydroxide (TPAH) , Tetrabutylammonium hydroxide (TBAH) and other alkaline aqueous solution developer, 3 seconds to 3 minutes, preferably 5 seconds to 2 minutes under the conditions of dip (dip) method, soak (puddle) method, spray ( Spray) method and other common methods of development will dissolve the irradiated part in the developing solution, and the unexposed part will not dissolve, forming the intended positive pattern on the substrate. The negative-type photoresist is opposite to the positive-type photoresist, that is, the light-exposed part is not soluble in the developing solution, and the unexposed part is dissolved. In addition, the photoresist material of the present invention is particularly suitable for fine patterning of KrF excimer laser, ArF excimer laser, EB, EUV, X-ray, soft X-ray, γ-ray, synchrotron radiation in high-energy rays .

It is also possible to use a positive photoresist material containing a base polymer containing an acid-labile group to perform negative development using organic solvent development to obtain a negative pattern. Examples of the developer used at this time include 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutyl ketone, methyl alcohol Cyclohexanone, acetophenone, methyl acetophenone, propyl acetate, butyl acetate, isobutyl acetate, pentyl acetate, butenyl acetate, isoamyl acetate, propyl formate, butyl formate, Isobutyl formate, amyl formate, isoamyl formate, methyl valerate, methyl pentenoate, methyl crotonate, ethyl crotonate, methyl propionate, ethyl propionate, 3-ethoxy Ethyl propionate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isobutyl lactate, amyl lactate, isoamyl lactate, methyl 2-hydroxyisobutyrate, 2-hydroxyisobutyric acid Ethyl ester, methyl benzoate, ethyl benzoate, phenyl acetate, benzyl acetate, phenyl methyl acetate, benzyl formate, phenyl ethyl formate, 3-phenyl methyl propionate, benzyl propionate , Ethyl phenylacetate, 2-phenylethyl acetate, etc. These organic solvents can be used alone or in combination of two or more.

Rinse at the end of development. The eluent is preferably a solvent that is miscible with the developer and does not dissolve the photoresist film. As for such a solvent, it is preferable to use an alcohol having 3 to 10 carbon atoms, an ether compound having 8 to 12 carbon atoms, an alkane, alkene, alkyne, or aromatic solvent having 6 to 12 carbon atoms.

Specifically, the alcohol having 3 to 10 carbon atoms includes n-propanol, isopropanol, 1-butanol, 2-butanol, isobutanol, third butanol, 1-pentanol, and 2 -Pentanol, 3-pentanol, tert-pentanol, neopentanol, 2-methyl-1-butanol, 3-methyl-1-butanol, 3-methyl-3-pentanol, cyclopentanol Alcohol, 1-hexanol, 2-hexanol, 3-hexanol, 2,3-dimethyl-2-butanol, 3,3-dimethyl-1-butanol, 3,3-dimethyl -2-butanol, 2-ethyl-1-butanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2-methyl-3-pentanol, 3-methyl -1-pentanol, 3-methyl-2-pentanol, 3-methyl-3-pentanol, 4-methyl-1-pentanol, 4-methyl-2-pentanol, 4-methyl -3-pentanol, cyclohexanol, 1-octanol, etc.

Examples of ether compounds having 8 to 12 carbon atoms include di-n-butyl ether, di-isobutyl ether, di-second butyl ether, di-n-pentyl ether, di-isoamyl ether, di-second amyl ether, and di-third amyl ether. Ether, di-n-hexyl ether, etc.

Examples of the C 6-12 alkane include hexane, heptane, octane, nonane, decane, undecane, dodecane, methylcyclopentane, dimethylcyclopentane, and cyclohexane. Hexane, methylcyclohexane, dimethylcyclohexane, cycloheptane, cyclooctane, cyclononane, etc. Examples of the C6-C12 olefins include hexene, heptene, octene, cyclohexene, methylcyclohexene, dimethylcyclohexene, cycloheptene, cyclooctene and the like. Examples of the alkyne having 6 to 12 carbon atoms include hexyne, heptyne, and octyne.

Examples of the aromatic solvents include toluene, xylene, ethylbenzene, cumene, tert-butylbenzene, mesitylene and the like.

By rinsing, the collapse of the photoresist pattern and the occurrence of defects can be reduced. Also, rinsing is not necessary, and the amount of solvent used can be reduced by not rinsing.

The developed hole pattern and trench pattern can also be shrunk by heat flow, RELACS technology or DSA technology. The shrinking agent is coated on the hole pattern and diffuses from the photoresist layer during baking through an acid catalyst, and crosslinking of the shrinking agent occurs on the surface of the photoresist, so that the shrinking agent adheres to the side wall of the hole pattern. The baking temperature is preferably 70 to 180°C, more preferably 80 to 170°C, and the time is preferably 10 to 300 seconds to remove excess shrinking agent and shrink the hole pattern. [Example]

The following describes the synthesis examples, examples, and comparative examples to explain the present invention in detail, but the present invention is not limited to the following examples.

[Synthesis Example 1-1] Synthesis of N-[(trifluoromethyl)sulfonyl]-2,3,5-triiodobenzylamine triphenylammonium (ammonium salt 1) [Chem 108]

After heating a mixed liquid of 100 g of 2,3,5-triiodobenzoic acid, 0.73 g of dimethylformamide and 700 g of chloroform to 60°C, 47.6 g of thiosulfonyl chloride was added dropwise. After stirring at 60°C for 21 hours, it was concentrated under reduced pressure to remove chloroform and unreacted sulfenyl chloride. 500 g of hexane was added to the concentrated solution and stirred for 1 hour to precipitate a solid. The obtained solid was filtered separately and washed once with hexane to obtain 97 g of 2,3,5-triiodobenzoyl chloride solid. To a mixture of 2.24 g of trifluoromethanesulfonyl amide, 3.73 g of potassium carbonate and 40 g of acetonitrile was added 10.1 g of the aforementioned 2,3,5-triiodobenzyl chloride, and the mixture was stirred at room temperature for 15 hours. After 120 g of pure water was added dropwise to quench the reaction, 6.74 g of triphenyl alkane methyl sulfate and 80 g of dichloromethane were added and stirred. After removing insoluble components by filtration, the organic layer was separated. The obtained organic layer was washed with 40 g of pure water, 40 g of 2.5% by mass hydrochloric acid, 40 g of pure water, 60 g of sodium bicarbonate aqueous solution, and 40 g of pure water in this order. The washed organic layer was concentrated under reduced pressure, 60 g of third butyl methyl ether was added to the obtained solution and stirred, and the supernatant was removed. The residue was concentrated under reduced pressure to obtain 10.5 g of N-[(trifluoromethyl)sulfonyl]-2,3,5-triiodobenzamide triphenylammonium (ammonium salt 1) as the target product. (Yield 78%).

The IR spectrum data of Ka salt 1 is shown below. The results of nuclear magnetic resonance spectroscopy ( ¹ H-NMR and ¹⁹ F-NMR/DMSO-d ₆ ) are shown in FIGS. 1 and 2 respectively. In addition, traces of residual solvent (third butyl methyl ether and water) were observed by ¹ H-NMR. IR(D-ATR): ν=3520, 3061, 2972, 1628, 1518, 1476, 1447, 1387, 1363, 1304, 1238, 1196, 1117, 1078, 1021, 998, 925, 865, 821, 748, 711 , 684, 614, 581, 502cm ^-1

[Synthesis Example 1-2～1-24] Synthesis of 鋶盐 2～15, 錪顊1-3～and Ammonium Salt 1-6 The structures of the sulfonamide-containing sulfonamide salt containing iodinated benzene ring 1-15, the iodide salt 1-3 and the ammonium salt 1-6 used in the photoresist material of the present invention are organized as follows. Bammonium salt 2 to 15 and tungsten salt 1 to 3 are the same as in Synthesis Example 1-1, by giving the following anions of sulfonamide containing benzene iodide ring, and methanesulfonate methanesulfonate with the following cation, chloride It is synthesized by ion exchange of carbamide or epichloride. Ammonium salts 1 and 2 are synthesized by the neutralization reaction of sulfonamide containing iodinated benzene ring and grade 4 ammonium hydroxide given to the following anions, ammonium salt 3 ～6 is synthesized by neutralizing the sulfonamide containing benzene iodide ring with tertiary amine compound to give the following anions.

[化109]

[化110]

[化111]

[化112]

[化113]

[Synthesis Examples 2-1 to 2-5] Synthesis of base polymer (Polymers 1 to 5) The monomers were combined and copolymerized in a THF solvent, precipitated in methanol, and washed repeatedly with hexane After isolation and drying, a base polymer (polymers 1 to 5) having the composition shown below was obtained. The composition of the obtained base polymer was confirmed by ¹ H-NMR, and Mw and Mw/Mn were confirmed by GPC (solvent: THF, standard: polystyrene).

[化114]

[化115]

[Examples 1 to 30, Comparative Examples 1 to 7] In a solvent in which 100 ppm of FC-4430 manufactured by 3M Company as a surfactant was dissolved, each component was dissolved into a solution according to the composition shown in Tables 1 to 3, and filtered with a 0.2 μm size filter to prepare a photoresist material.

In Tables 1-3, each component is as follows. Organic solvent: PGMEA (propylene glycol monomethyl ether acetate) GBL (γ-butyrolactone) CyH (cyclohexanone) PGME (Propylene Glycol Monomethyl Ether) DAA (diacetone alcohol)

Acid generator: PAG1～PAG7 (refer to the following structural formula) [Chem 116]

[化117]

Comparative quenching agent 1～6 (refer to the following structural formula) [Chem 118]

[EB exposure evaluation] Spin-coat the photoresist materials shown in Tables 1 to 3 on a Si substrate with an anti-reflective film DUV-62 made by Nissan Chemical Industry Co., Ltd. at a thickness of 60 nm, and pre-bake at 105°C for 60 seconds using a hot plate To produce a photoresist film with a thickness of 50 nm. It was exposed using an EB drawing device (ELS-F125, accelerating voltage 125 kV) manufactured by Elionix, subjected to PEB on the hot plate at the temperatures described in Tables 1 to 3 for 60 seconds, and developed with 2.38% by mass TMAH aqueous solution for 30 seconds. A positive photoresist pattern (a hole pattern with a size of 24 nm) was formed in Examples 1 to 13, 15 to 30, and Comparative Examples 1 to 6, and a negative photoresist pattern (a dot pattern with a size of 24 nm) was formed in Examples 14 and Comparative Example 7. ). Using the length measuring SEM (CG5000) made by Hitachi Advanced Technologies Co., Ltd., the exposure amount when the hole or dot is formed at 24 nm is defined as the sensitivity, and the diameter of the hole or dot is measured at 50 points at this time to find the size variation 3σ, as CDU. The results are shown in Tables 1 to 3.

[Table 1]

[Table 2]

[table 3]

From the results shown in Tables 1 to 3, it can be seen that the photoresist material of the present invention containing the onium salt represented by formula (A) has high sensitivity and low CDU.

[Fig. 1] ¹ H-NMR spectrum of kan salt 1 obtained in Synthesis Example 1-1. [Fig. 2] ¹⁹ F-NMR spectrum of the manganese salt 1 obtained in Synthesis Example 1-1.

Claims (15)

A photoresist material comprising a basic polymer and an onium salt represented by the following formula (A);

In the formula, R ¹ is a hydrogen atom, a hydroxyl group, a C 1-6 alkyl group, a C 1-6 alkoxy group, a C 2-7 alkoxy group, a C 2-7 alkoxycarbonyl group , Alkyl sulfonyloxy group having 1 to 4 carbon atoms, fluorine atom, chlorine atom, bromine atom, amine group, nitro group, cyano group, -NR ^1A -C(=O)-R ^1B , or -NR ^1A- C(=O)-OR ^1B ; part or all of the hydrogen atoms of the alkyl, alkoxy, alkoxy, alkoxycarbonyl and alkylsulfonyloxy groups can also be replaced by halogen atoms; R ^1A is hydrogen Atom, or C 1-6 alkyl; R ^1B is C 1-6 alkyl, or C 2-8 alkenyl; R ² is C 1-10 alkyl, or C 6 Aryl group of ～10, part or all of its hydrogen atoms may be substituted with amine group, nitro group, cyano group, alkyl group with carbon number 1-12, alkoxy group with carbon number 1-12, carbon number 2-12 Alkoxycarbonyl group, C2-C12 acetyl group, C2-C12 alkylcarbonyloxy group, hydroxyl group, or halogen atom; X ¹ is a single bond, or a C1-C20 divalent linking group , May also contain an ether bond, a carbonyl group, an ester bond, an amide bond, a sultone ring, a lactam ring, a carbonate bond, a halogen atom, a hydroxyl group or a carboxyl group; m and n are in accordance with 1≦m≦5, 0≦ n≦4, and an integer of 1≦m+n≦5; M ⁺ is a cation represented by the following formula (Aa), a cation represented by the following formula (Ab) or an ammonium cation represented by the following formula (Ac);

In the formula, R ^a1 to R ^a3 are each independently a halogen atom, or a C 1-20 monovalent hydrocarbon group which may also contain a heteroatom; and any one of R ^a1 , R ^a2 and R ^a3 may be mutually Bond and form a ring together with the sulfur atom to which they are bonded; R ^a4 and R ^a5 are each independently a halogen atom, or a monovalent hydrocarbon group of 1 to 20 carbon atoms which may also contain a heteroatom; R ^a6 to R ^a9 each It is independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 24 carbon atoms, and may also contain a halogen atom, a hydroxyl group, a carboxyl group, an ether bond, an ester bond, a thiol group, a thioester bond, a thiocarbonyl ester bond, and a dithioester bond , amino, nitro, sulfone or ferrocenyl group; R ^a6 and R ^a7 may be bonded to each other and the nitrogen atom to which they are bonded together form a ring of, R ^a6, and R ^a7 and R ^a8 and R ^a9, may each mutually bonded and the nitrogen atom to which they are bonded's together form a spiro ring, may also be R ^{a8 a9} combined with R to form ^{= C (R a10) (R} a11); R a10 and R ^A11 each independently A hydrogen atom or a monovalent hydrocarbon group having 1 to 16 carbon atoms; in addition, R ^a10 and R ^a11 may also be bonded to each other and form a ring together with the carbon atom and nitrogen atom to which they are bonded, and the ring may also contain a double Bond, oxygen atom, sulfur atom or nitrogen atom. For example, the photoresist material in the first item of patent scope, where m is an integer that meets 2≦m≦4. For example, the photoresist material in item 1 or 2 of the patent application scope further contains an acid generator that generates sulfonic acid, imidic acid or methylated acid. For example, the photoresist material in item 1 or 2 of the patent scope further contains organic solvents. For example, the photoresist material of the first or second patent application scope, wherein the base polymer contains a repeating unit represented by the following formula (a1) or a repeating unit represented by the following formula (a2);

In the formula, R ^{A is} each independently a hydrogen atom or a methyl group; Y ¹ is a single bond, a phenyl group or a naphthyl group, or a linking group having 1 to 12 carbon atoms containing an ester bond or a lactone ring; Y ² is Single bond or ester bond; R ¹¹ and R ¹² are acid labile groups. For example, the photoresist material in item 5 of the patent scope is a chemically amplified positive photoresist material. For example, the photoresist material according to item 1 or 2 of the patent application scope, in which the base polymer does not contain acid labile groups. For example, the photoresist material in item 7 of the patent application scope further contains a crosslinking agent. For example, the photoresist material in item 7 of the patent application scope is a chemically amplified negative photoresist material. For example, the photoresist material according to item 1 or 2 of the patent application, wherein the base polymer further contains at least one selected from repeating units represented by the following formulas (f1) to (f3);

In the formula, R ^{A is} each independently a hydrogen atom or a methyl group; Z ¹ is a single bond, phenylene, -OZ ¹¹ -, -C(=O)-OZ ¹¹ -or -C(=O)-NH- Z ¹¹ -, Z ¹¹ is an alkanediyl group having 1 to 6 carbon atoms, an alkanediyl group having 2 to 6 carbon atoms, or a phenylene group, and may also contain a carbonyl group, an ester bond, an ether bond, or a hydroxyl group; Z ² is a single bond , -Z ²¹ -C(=O)-O-, -Z ²¹ -O- or -Z ²¹ -OC(=O)-, Z ²¹ is an alkanediyl group having 1 to 12 carbon atoms, and may also contain a carbonyl group, Ester bond or ether bond; Z ³ is a single bond, methylene, ethylidene, phenylene, fluorinated phenylene, -C(=O)-OZ ³¹ -or -C(=O)-NH- Z ³¹ -, Z ³¹ is an alkanediyl group having 1 to 6 carbon atoms, a phenylene group, a fluorinated phenylene group, a phenylene group substituted with a trifluoromethyl group, or an alkaneyl group having 2 to 6 carbon atoms, also May contain a carbonyl group, an ester bond, an ether bond, or a hydroxyl group; A is a hydrogen atom or a trifluoromethyl group; R ²¹ to R ²⁸ are each independently a monovalent hydrocarbon group of 1 to 20 carbon atoms which may also contain a heteroatom; and, R Any one of ²³ , R ²⁴ and R ²⁵ , or any two of R ²⁶ , R ²⁷ and R ²⁸ may also be bonded to each other and form a ring together with the sulfur atom to which they are bonded; M ^-is non Nucleophilic relative ion. For example, the photoresist material in item 1 or 2 of the patent application scope further contains a surfactant. A pattern forming method includes the following steps: Applying the photoresist material according to any one of patent application items 1 to 11 on the substrate, and performing heat treatment to form a photoresist film; Expose the photoresist film with high-energy rays; and The developer is used to develop the exposed photoresist film. For example, in the pattern forming method of claim 12, the high energy ray is an ArF excimer laser with a wavelength of 193 nm or a KrF excimer laser with a wavelength of 248 nm. For example, in the pattern forming method of claim 12, the high-energy rays are electron beams or extreme ultraviolet rays with a wavelength of 3 to 15 nm. One kind of salt represented by the following formula (B);

In the formula, R ¹ is a hydrogen atom, a hydroxyl group, a C 1-6 alkyl group, a C 1 to 6 alkoxy group, a C 2 to 7 alkoxy group, a C 2 to 7 alkoxycarbonyl group , Alkyl sulfonyloxy group having 1 to 4 carbon atoms, fluorine atom, chlorine atom, bromine atom, amine group, nitro group, cyano group, -NR ^1A -C(=O)-R ^1B , or -NR ^1A- C(=O)-OR ^1B ; part or all of the hydrogen atoms of the alkyl, alkoxy, alkoxy, alkoxycarbonyl and alkylsulfonyloxy groups can also be replaced by halogen atoms; R ^1A is hydrogen Atom, or C 1-6 alkyl; R ^1B is C 1-6 alkyl, or C 2-8 alkenyl; R ² is C 1-10 alkyl, or C 6 Aryl group of ~10, part or all of its hydrogen atoms may be substituted with amine group, nitro group, cyano group, alkyl group with carbon number 1-12, alkoxy group with carbon number 1-12, carbon number with 2-12 Alkoxycarbonyl group, C2-C12 acetyl group, C2-C12 alkylcarbonyloxy group, hydroxyl group, or halogen atom; X ¹ is a single bond, or a C1-C20 divalent linking group , May also contain ether bond, carbonyl group, ester bond, amide bond, sultone ring, lactam ring, carbonate bond, halogen atom, hydroxyl group or carboxyl group; m and n are in accordance with 1≦m≦5, 0≦ n≦4, and an integer of 1≦m+n≦5; R ^a1 to R ^a3 are each independently a halogen atom, or a monovalent hydrocarbon group of 1 to 20 carbon atoms which may also contain a heteroatom; and R ^a1 , R ^a2 and Any two of R ^a3 may also be bonded to each other and form a ring together with the sulfur atom to which they are bonded.

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