TWI712580B - 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 present invention relates to photoresist materials and pattern forming methods.

With the expansion of the IoT market, high integration, high speed, and low power consumption of LSI are further required, and the miniaturization of pattern rules is progressing rapidly. Especially logic devices are leading the miniaturization. As the most advanced miniaturization technology, mass production of 10nm node devices using double patterning, triple patterning, and quadruple patterning using immersion ArF lithography has been carried out, and the next-generation extreme ultraviolet light with a wavelength of 13.5nm has also been used. (EUV) Research on 7nm node devices by lithography.

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

For chemically amplified positive photoresist materials that add acid generators and use light or electron beam (EB) irradiation to generate acid and cause deprotection reactions, and chemically amplified negative photoresist materials that use acids 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 of the hole pattern, trench pattern, and focus latitude decrease in the positive photoresist film. In order to prevent 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.

Someone proposes to use the chemically amplified photoresist material of the acid multiplication mechanism that produces acid due to acid. Generally, as the exposure amount increases, the acid concentration gradually increases linearly, but in the case of acid proliferation, the acid concentration increases nonlinearly with respect to the increase in the exposure amount. The acid proliferation system has the advantage of further promoting the high contrast and high sensitivity of the chemically amplified photoresist film, but the environmental resistance deteriorates due to amine pollution, and the limit resolution decreases due to the increase of the acid diffusion distance. The shortcomings of chemically amplified photoresist film will be more degraded, when it is put into practical use, it is a very difficult mechanism to control.

In order to make the contrast better, there is another method to decrease the concentration of amine as the exposure amount increases. It is thought that compounds that lose their function as quenchers due to light can be used.

The acid labile group used in the (meth)acrylate polymer used in ArF photoresist materials will cause the deprotection reaction to proceed due to the use of a photoacid generator that produces a fluorine-substituted sulfonic acid at the α-position, but the α-position Non-fluorine-substituted sulfonic acid and carboxylic acid generators do not undergo deprotection reaction. If the sulfonic acid salt and iodonium salt of sulfonic acid substituted by fluorine in the α position are mixed with the sulfonic acid salt and iodonium salt of the sulfonic acid not substituted by fluorine in the α position, the sulfonic acid which is not substituted by fluorine in the α position will be produced. Salt and iodonium salt will exchange ion with the sulfonic acid substituted by fluorine at the α position. The sulfonic acid substituted by fluorine at the α position generated by light will return to sulfonic acid and iodonium salt due to ion exchange. Therefore, the sulfonic acid, sulfonic acid, sulfonic acid salt and iodonium salt without fluorine substitution at the α position are used as quenchers. effect.

In addition, sulfonic acid salts and iodonium salts that produce sulfonic acids that are not substituted by fluorine at the α position lose their ability as quenchers due to photolysis, and therefore also function as photodegradable quenchers. The structural formula is unknown, but it shows that the latitude of the trench pattern is enlarged due to the addition of the photodegradable quencher (Non-Patent Document 1). However, the effect on performance improvement is small, and it is hoped to develop a quencher with better contrast.

Patent Document 4 proposes an onium salt-type quencher that generates carboxylic acid having an amino group due to light, and generates lactamine due to the acid, resulting in a decrease in basicity. Due to the mechanism of reducing alkalinity due to acid, the diffusion of acid is controlled in the unexposed part where the amount of acid is less generated due to high alkalinity, and the overexposed part where the amount of acid is generated is controlled by the quencher The alkalinity decreases and the diffusion of acid increases. Thereby, the gap between the amount of acid in the exposed part and the unexposed part can be enlarged, and the contrast can be improved. However, in this case, there is an advantage of improved contrast, but the control effect of acid diffusion decreases.

With the miniaturization of patterns, the edge roughness (LWR) of the line pattern and the size uniformity (CDU) of the hole pattern are regarded as problems. The inhomogeneity of the base polymer and the acid generator, the influence of aggregation, and the influence of acid diffusion have been criticized. Furthermore, with the thinning of the photoresist film, the LWR tends to increase, and the thinning with the progress of the miniaturization causes the deterioration of the LWR to become 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 lowering the post-exposure bake (PEB) temperature, the LWR is reduced, but the sensitivity is low. The addition of quencher increases LWR, but the sensitivity is low. The trade-off relationship between sensitivity, LWR and CDU must be broken. In addition, EB and EUV are both high-energy rays, and there is a trade-off relationship between sensitivity, LWR and CDU.

The energy of EUV is much higher than that of ArF excimer laser, and the number of photons in EUV exposure is 14 times that of 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 region of extremely short wavelength radiation, the variation of the number of photons is a physical phenomenon of shot noise, which cannot be eliminated.

Stochastics is gradually being promoted. Although the impact of shot noise cannot be eliminated, there are discussions on how to reduce its impact. The impact of shot noise will not only increase the CDU and LWR, but also observe the phenomenon of clogging with a probability of one in a million. If the hole is blocked, the current will be poor and the transistor will not operate, which will adversely affect the performance of the entire device. As far as the method of reducing the impact of shot noise on the photoresist side is concerned, it has been proposed to increase the absorption of the photoresist to absorb more photons. Because the polymer-based photoresist material will cause variation, the development of single-component low-molecular-weight light Resistance (Non-Patent Document 2).

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

[Patent Document 1] Japanese Patent Application Publication No. 2001-194776 [Patent Document 2] JP 2002-226470 A [Patent Document 3] Japanese Patent Laid-Open No. 2002-363148 [Patent Document 4] JP 2015-90382 A [Patent Document 5] Japanese Patent Application Publication No. 2018-5224 [Patent Document 6] Japanese Patent Application Publication 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)

(Problems to be solved by the invention)

For chemically amplified photoresist materials that use acid as a catalyst, it is hoped to develop photoresist materials that have high sensitivity and can reduce LWR and CDU quenchers and acid generators, and can contribute to the reduction of shot noise.

In view of the foregoing, the present invention aims to provide a photoresist material with high sensitivity and low LWR and CDU, and a pattern forming method using the photoresist material. (The way to solve the problem)

The inventors of the present case made diligent studies to achieve the foregoing objective and found that by using an onium salt of N-carbonylsulfonamide with an iodinated benzene ring as a quencher or acid generator, high sensitivity and LWR can be obtained. , The CDU is small, the contrast is high, the resolution is excellent, and the photoresist material with wide processing latitude is processed, which is the completion of the present invention.

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 comprising 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, an alkyl group with 1 to 6 carbons, an alkoxy group with 1 to 6 carbons, an acyloxy group with 2 to 7 carbons, and an alkoxycarbonyl group with 2 to 7 carbons. , Alkylsulfonyl group with 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 group, alkoxy group, acyloxy group, alkoxycarbonyl group and alkylsulfonyloxy group may be substituted with halogen atoms; R ^1A is hydrogen Atom, or alkyl with 1 to 6 carbons; R ^1B is alkyl with 1 to 6 carbons, or alkenyl with 2 to 8 carbons; R ² is alkyl with 1 to 10 carbons, or 6 ～10 aryl groups, part or all of the hydrogen atoms can be substituted with amine, nitro, cyano, C1-C12 alkyl, C1-C12 alkoxy, C2-C12 Alkoxycarbonyl group, acyl group with 2-12 carbons, alkylcarbonyloxy group with 2-12 carbons, hydroxyl group, or halogen atom; X ¹ is a single bond or a divalent linking group with 1-20 carbons , Can 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), an iodonium cation represented by the following formula (Ab) or an ammonium cation represented by the following formula (Ac); [化2]

In the formula, R ^a1 to R ^a3 are each independently a halogen atom, or a monovalent hydrocarbon group with 1 to 20 carbon atoms that may contain a hetero atom; and any two 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 with 1 to 20 carbon atoms that may also contain a heteroatom; R ^a6 to R ^a9 each Independently a hydrogen atom or a monovalent hydrocarbon group with 1 to 24 carbon atoms, and may also contain halogen atoms, hydroxyl groups, carboxyl groups, ether bonds, ester bonds, thiol groups, thioester bonds, thiocarbonyl ester bonds, and dithioester bonds , Amine, nitro, sulfonyl or ferrocene; R ^a6 and R ^a7 can also bond with 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 , They can also be bonded to each other and form a spiro ring together with the nitrogen atom to which they are bonded, or R ^a8 and R ^a9 can 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 with 1 to 16 carbon atoms; R ^a10 and R ^a11 may also be bonded to each other and form a ring with the carbon atom and nitrogen atom to which they are bonded. The ring may also contain double Bond, oxygen atom, sulfur atom or nitrogen atom. 2. The photoresist material as in 1., where m is an integer conforming to 2≦m≦4. 3. Photoresist materials such as 1. or 2. contain acid generators that produce sulfonic acid, imidic acid or methylated acid. 4. Photoresist materials such as any one of 1. to 3. contain organic solvents. 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); [化3]

In the formula, R ^{A is} each independently a hydrogen atom or a methyl group; Y ¹ is a single bond, a phenylene group or a naphthylene group, or a linking group with 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 as in 5. is a chemically amplified positive photoresist material. 7. The photoresist material of any one of 1. to 4., wherein the base polymer does not contain acid labile groups. 8. The photoresist material as in 7. contains cross-linking agent. 9. 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 repeating unit selected from the following formulas (f1) to (f3); [化4]

In the formula, R ^{A is} each independently a hydrogen atom or a methyl group; Z ¹ is a single bond, a phenylene group, -OZ ¹¹ -, -C(=O)-OZ ¹¹ -or -C(=O)-NH- Z ¹¹ -, Z ¹¹ is alkanediyl with 1 to 6 carbons, alkene with 2 to 6 carbons, or phenylene, 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 with 1 to 12 carbons, and may also contain a carbonyl group, Ester bond or ether bond; Z ³ is a single bond, methylene, ethylene, phenylene, fluorinated phenylene, -C(=O)-OZ ³¹ -or -C(=O)-NH- Z ³¹ -, Z ³¹ is an alkanediyl group with 1 to 6 carbons, a phenylene group, a fluorinated phenylene group, a phenylene group substituted with a trifluoromethyl group, or an alkenediyl group with a carbon number of 2-6. It 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 with 1 to 20 carbon atoms and may also contain a hetero atom; and R Any two 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 not Nucleophilic relative ion. 11. The photoresist material of any one of 1. to 10. further contains a surfactant. 12. A pattern forming method, comprising the following steps: coating the photoresist material of any one of 1. to 11. on a substrate, and performing heat treatment to form a photoresist film; exposing the photoresist film to high-energy rays ; And use a developer to develop the exposed photoresist film. 13. The pattern forming method of 12., wherein the high-energy ray is an ArF excimer laser with a wavelength of 193nm or a KrF excimer laser with a wavelength of 248nm. 14. The pattern forming method according to 12., wherein the high-energy rays are electron beams or extreme ultraviolet rays with a wavelength of 3-15 nm. 15. A kind of salt represented by the following formula (B); [化5]

In the formula, R ¹ , R ² , X ¹ , m, n, and ^Ra1 to ^{Ra3 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, and there will be many secondary Electronics can make the sensitivity better. The anion of the aforementioned onium salt has a long binding distance with the onium cation due to the steric barriers attached to both sides of the amide bond. Compared with the quencher of the onium carboxylate, it is easier to ion exchange with the sulfonic acid. That is, the ability to act as a quencher is high, thereby obtaining high contrast. In addition, when the sulfonamide group has a fluorinated alkyl group or an aryl group, the strength of the acid generated is high, so it acts as an acid generator. In this case, it acts as an acid generator with little acid diffusion.

[Photoresist material] The photoresist material of the present invention contains a base polymer and an onium salt of N-carbonylsulfonamide with iodinated benzene ring (hereinafter also referred to as sulfonamide containing iodinated benzene ring). When the aforementioned onium salt is a sulfonium salt or an iodonium salt, they are acid generators that produce sulfonamides containing an iodinated benzene ring due to light irradiation, but they are also used as a strong alkaline sulfonium salt or iodonium salt because of the form Quencher effect. The aforementioned sulfonamides containing iodinated benzene rings generate strong acids when bonded with fluorine-substituted alkyl and aryl groups, so they function as acid generators. On the other hand, when there is no fluorine atom, there is no acidity that causes the deprotection reaction of the acid labile group. Therefore, as described later, in order to cause the deprotection reaction of the acid labile group additionally, a sulfonic acid that generates a strong acid is added , Imidic acid or methylated acid acid generator is 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 a base polymer.

If the aforesaid sulfonamide salt or iodonium salt containing iodinated benzene ring and the acid generator of perfluoroalkyl sulfonic acid that generate super acid are irradiated in a mixed state, it will produce sulfonamide containing iodinated benzene ring and Perfluoroalkyl sulfonic acid. The acid generator will not completely decompose, so there will be undecomposed acid generator nearby. Here, if the sulfonamide salt or sulfonamide containing iodinated benzene ring coexists with perfluoroalkyl sulfonic acid, the perfluoroalkyl sulfonic acid will initially interact with the sulfonamide containing iodinated benzene ring. Or iodine salt exchanges ion and generates perfluoroalkane sulfonate salt, releasing sulfonamide containing iodinated benzene ring. The reason is that perfluoroalkane sulfonate, which is strong in terms of acid, is relatively stable. On the other hand, even if the perfluoroalkyl sulfonate or iodonium salt and the sulfonamide containing iodide benzene ring exist, there will be no ion exchange. Not only perfluoroalkane sulfonic acid, but aryl sulfonic acid, alkyl sulfonic acid, imidic acid, methylated acid, etc. whose acid strength is higher than that of sulfonamide containing iodinated benzene ring will also perform the same ion exchange .

The sulfonamide salt, iodonium salt or ammonium salt containing iodinated benzene ring not only inhibits acid diffusion, but also has high EUV absorption, which generates secondary electrons, which can increase the sensitivity of the photoresist and reduce shot noise . The sulfonamide salt, iodonium salt or ammonium salt containing iodinated benzene ring is not only used as an acid generator or quencher for acid diffusion control, but also as a sensitizer.

The photoresist material of the present invention needs to contain a sulfonamide salt, an iodonium salt or an ammonium salt containing an iodinated benzene ring, but other sulfonium salts or iodonium salts can also be added as a quencher. In this case, the sulfonium salt and the sulfonium salt added as the quenching agent are preferably sulfonium salts or sulfonium salts such as carboxylic acid, sulfonic acid, imidic acid, and saccharin. The carboxylic acid at this time may be fluorinated or unfluorinated at the α position.

The photoresist material of the present invention can also be an acid generator composed of a sulfonamide salt or an iodonium salt bonded to a fluorine-substituted alkyl group or an aryl group, and an acid generator bonded to an alkyl group without a fluorine atom The quencher composed of the sulfonamide salt of the aryl group is combined.

In order to make LWR better, as mentioned above, it is effective to suppress aggregation of polymers and acid generators. In order to inhibit the aggregation of polymers, it is effective to reduce the gap between hydrophobicity and hydrophilicity and lower the glass transition point (Tg). Specifically, it is effective to reduce the polarity difference between the hydrophobic acid labile group and the hydrophilic adhesive group, and use a tight adhesive group such as a monocyclic lactone to reduce Tg. In order to inhibit the aggregation of the acid generator, it is effective to introduce a substituent group into the cation part of triphenylaluminium. Especially for the methacrylate polymer for ArF formed by the alicyclic protecting group and the adhesion group of the lactone, the heterostructure of the triphenylaluminum series formed only by the aromatic group has low compatibility. As the substituent introduced into the triphenyl sulfonium, it is considered that it may be the same alicyclic group or lactone as the base polymer user. The sulfonium salt is hydrophilic, so when the lactone is introduced, the hydrophilicity will become too high, and the compatibility with the polymer will decrease, causing the agglomeration of the sulfonium salt. The introduction of hydrophobic alkyl groups can make the sulfonium salt evenly dispersed in the photoresist film. In International Publication No. 2011/048919, a method of introducing an alkyl group into a sulfonium salt that produces a fluorinated sulfimidic acid at the α position is proposed to make LWR better.

For the improvement of LWR, 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 not uniformly present, it may cause the decrease in LWR. In the sulfonium salt type quencher, if the cation moiety of triphenylsulfonium is introduced into a substituent such as an alkyl group, it is effective for improving LWR. Furthermore, if halogen atoms are introduced into the quencher of the sulfonium salt type, the hydrophobicity can be improved efficiently and the dispersibility can be better. The introduction of bulky halogen atoms such as iodine is effective not only for the cation part of the alium salt, but also for the anion part. The aforementioned sulfonamide salt containing iodinated benzene ring, by introducing iodine atoms into the anion part, will increase the dispersibility of the quencher in the photoresist film and reduce LWR.

The aforementioned LWR reduction effect of the sulfonamide salt, iodonium salt or ammonium salt containing the iodinated benzene ring is effective in the positive pattern formation, the negative pattern formation, and the negative pattern formation in the organic solvent development by alkali development.

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

In the formula (A), R ¹ is a hydrogen atom, a hydroxyl group, an alkyl group with 1 to 6 carbons, an alkoxy group with 1 to 6 carbons, an acyloxy group with 2 to 7 carbons, and an alkane with 2 to 7 carbons. Oxycarbonyl group, alkylsulfonyloxy group with 1 to 4 carbon atoms, fluorine atom, chlorine atom, bromine atom, amino 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 aforementioned alkyl group, alkoxy group, acyloxy group, alkoxycarbonyl group and alkylsulfonyloxy group may 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 carbons or an alkenyl group having 2 to 8 carbons.

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

In the formula (A), R ² is an alkyl group with 1 to 10 carbons or an aryl group with 6 to 10 carbons, and part or all of its hydrogen atoms may be substituted with amino, nitro, cyano, carbon 1-12 alkyl group, carbon number 1-12 alkoxy group, carbon number 2-12 alkoxycarbonyl group, carbon number 2-12 acyl group, carbon number 2-12 alkylcarbonyloxy group, hydroxyl group , Or halogen atom.

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

The aryl group having 6 to 10 carbon atoms includes phenyl and naphthyl.

In formula (A), X ¹ is a single bond, or a divalent linking group with 1 to 20 carbons, and may also contain ether bond, carbonyl group, ester bond, amide bond, sultone ring, lactam ring, carbonic acid Ester bond, halogen atom, hydroxyl or carboxyl group. Among them, X ¹ is preferably a single bond.

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

As for the anion of the onium salt represented by the formula (A), the following but not limited to these can be mentioned. [化7]

[化8]

[化9]

[化10]

[化11]

[化12]

[化13]

In the formula (A), M ⁺ is a cation represented by the following formula (Aa), an iodonium 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 cation represented by the formula (Aa), the onium salt represented by the formula (A) is a sulfonium salt represented by the following formula (B). [化15]

In the formula, R ¹ , R ² , X ¹ , m, n, and ^Ra1 to ^{Ra3 are the} same as described above.

In formulas (Aa) and (Ab), ^Ra1 to ^Ra3 are each independently a halogen atom, or a monovalent hydrocarbon group with 1 to 20 carbon atoms that may contain a hetero atom. ^Furthermore , any two of R ^a1 , R ^a2 and R ^a3 may be bonded to each other and form a ring 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 having 1 to 20 carbon atoms which may contain a hetero atom.

The aforementioned monovalent hydrocarbon group may be linear, branched, or cyclic. Specific examples include alkyl groups having 1 to 20 carbon atoms, alkenyl groups having 2 to 12 carbon atoms, and 2 carbon atoms. -12 alkynyl groups, aryl groups with 6 to 20 carbons, aralkyl groups with 7 to 12 carbons, aryloxyalkyl groups with 7 to 12 carbons, etc. In addition, part or all of the hydrogen atoms of these groups may be substituted with hydroxyl groups, carboxyl groups, halogen atoms, pendant oxy groups, cyano groups, amide bonds, nitro groups, sultone groups, sulfonium groups, or sulfonate-containing groups A part of the carbon atoms of these groups can also be substituted with ether bonds, ester bonds, carbonyl groups, carbonate bonds or sulfonate bonds.

In the formula (Ac), ^Ra6 to ^Ra9 are each independently a hydrogen atom or a monovalent hydrocarbon group with 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 a sulfur group. 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 to the nitrogen atom to which they are bonded. Together to form a spiro ring, ^Ra8 and ^Ra9 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 aforementioned 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 Alkynyl groups having 2-24, aryl groups having 6-20 carbons, aralkyl groups having 7-20 carbons, groups obtained by combining them, and the like.

The alium cation represented by the formula (Aa) can be listed as follows but not limited to these. [化16]

[化17]

[化18]

[化19]

[化20]

[化21]

[化22]

[化23]

[化24]

[化25]

The iodo cation represented by the formula (Ab) can be listed as follows but not limited to these. [化26]

The ammonium cation represented by the formula (Ac) can be listed as follows but not limited to them. [化27]

[化28]

[化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 of synthesizing the onium salt represented by the formula (A), an ion exchange method with an onium salt of a weaker acid than the sulfonamide containing an iodinated benzene ring can be cited. Examples of acids weaker than sulfonamides containing iodinated benzene rings include hydrochloric acid, carbonic acid, carboxylic acid, and sulfonic acid containing no fluorine atom. In addition, the sodium salt of sulfonamide containing iodinated benzene ring may be synthesized by ion exchange with onium chloride salt.

In the photoresist material of the present invention, the content of the onium salt represented by formula (A) relative to 100 parts by mass of the base polymer described later, considering the sensitivity and acid diffusion inhibitory effect, is preferably 0.001-50 parts by mass, 0.01-20 The mass portion is more ideal.

[Base polymer] The base polymer contained in the photoresist material of the present invention contains a repeating unit containing an acid labile group when it is a positive photoresist material. The repeating unit containing an acid labile group is preferably a repeating unit represented by the following formula (a1) (hereinafter also referred to as repeating unit a1) or a repeating unit represented by formula (a2) (hereinafter also referred to as repeating unit a2). 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 group or a 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 aforementioned 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 monomers giving the repeating unit a1 include the following but are not limited to these. In addition, in the following formula, R ^A and R ^{11 are the} same as described above. [化48]

Examples of the monomers giving the repeating unit a2 include the following but are not limited to these. In addition, in the following formula, R ^A and R ^{12 are the} same as described above. [化49]

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

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

In the formulas (AL-1) and (AL-2), R ^L1 and R ^L2 are monovalent hydrocarbon groups having 1 to 40 carbon atoms, and may contain heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and fluorine atoms. The aforementioned 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 the 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 heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and fluorine atoms. The aforementioned monovalent hydrocarbon group may be any of linear, branched, and cyclic, and is preferably an alkyl group having 1 to 20 carbon atoms. Moreover, any two of R ^L2 , R ^L3 and R ^L4 may be bonded to each other and form a carbon 3-20 ring 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, and an alicyclic ring is particularly preferred.

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

The aforementioned base polymer may further contain a repeating unit b containing a phenolic hydroxyl group as an adhesive group. Examples of the monomers giving the repeating unit b include the following but not limited to these. Also, in the following formula, R ^{A is the} same as described above. [化51]

The aforementioned base polymer may further contain 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 the repeating unit c of other adhesive groups. Examples of the monomers giving the repeating unit c include the following but not limited to these. Also, 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 base polymer may further contain repeating units d derived from indene, benzofuran, benzothiophene, vinyl naphthalene, chromone, coumarin, norbornadiene or these derivatives. Examples of the monomers that give the repeating unit d include but are not limited to the following.

[化60]

The aforementioned base polymer may further contain repeating units e derived from styrene, vinyl naphthalene, vinyl anthracene, vinyl pyrene, methylene dihydroindene, 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 Patent Application Laid-Open No. 2005-84365 proposes a salt and an iodonium salt containing polymerizable unsaturated bonds that generate specific sulfonic acids. Japanese Patent Laid-Open No. 2006-178317 proposes a sulfonic acid salt in which sulfonic acid is directly bonded to the main chain.

As an ideal repeating unit f, the repeating unit represented by the following formula (f1) (hereinafter also referred to as repeating unit f1), the repeating unit represented by the following formula (f2) (hereinafter also referred to as repeating unit f2.), and the following The repeating unit represented by the 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 kinds. [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 alkane with 1 to 6 carbon atoms A group, a C2-C6 alkenediyl group, or a phenylene group 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 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, ethylene, phenylene, fluorinated phenylene, -C(=O)-OZ ³¹ -or -C(=O)-NH-Z ³¹ -, Z ³¹ Alkylene diyl group with 1 to 6 carbons, phenylene group, fluorinated phenylene group, phenylene group substituted by trifluoromethyl group, or alkenediyl group with carbon number 2 to 6, may also contain carbonyl group and ester bond , Ether bond or hydroxyl. A is a hydrogen atom or a trifluoromethyl group.

In the formulas (f1) to (f3), R ²¹ to R ²⁸ are each independently a monovalent hydrocarbon group with 1 to 20 carbon atoms that may 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 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 include the same as those described above for R ^a1 to R ^a3 in formula (Aa). The alium cation in the formulas (f2) and (f3) may be the same as the alium cation represented by the formula (Aa) in the foregoing.

In formula (f1), M ^{-is a} non-nucleophilic relative ion. The aforementioned non-nucleophilic relative ions include halide ions such as chloride ion and bromide ion, trifluoromethanesulfonate ion, 1,1,1-trifluoroethanesulfonate ion, nonafluorobutanesulfonate ion, etc. Fluoroalkylsulfonate ion, tosylate ion, benzenesulfonate ion, 4-fluorobenzenesulfonate ion, 1,2,3,4,5-pentafluorobenzenesulfonate ion, etc. Alkylsulfonate ions such as sulfonate ion and butanesulfonate ion, bis(trifluoromethylsulfonyl) iminium ion, bis(perfluoroethylsulfonyl) iminium ion, bis(perfluoromethylsulfonyl) Butylsulfonyl) iminium ion and other iminium ions, ginseng (trifluoromethyl sulfonyl) methide ion, ginseng (perfluoroethyl sulfonyl) methide ion and other methide ions .

The aforementioned non-nucleophilic relative ions can further include sulfonic acid ions represented by the following formula (K-1) substituted by fluorine atoms at the α position, and sulfonic acid ions represented by the following formula (K-2) substituted by fluorine atoms at the α and β positions Ions etc. [化62]

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

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

Examples of the monomers giving the repeating unit f1 include the following but are not limited to these. In addition, in the following formula, R ^A and M ^{-are the} same as above. [化63]

Examples of the monomers giving the repeating unit f2 include the following but are not limited to these. Also, 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 monomers giving the repeating unit f3 include the following but are not limited to these. Also, in the following formula, R ^{A is the} same as described above. [化69]

[化70]

By bonding the acid generator to the polymer backbone, the acid diffusion can be reduced, and the degradation of the resolution due to the blur of the acid diffusion can be prevented. 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 base polymer used in the positive photoresist material, the 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 are more preferable, 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 desirable. In addition, when the repeating unit f is at least one selected from the repeating units f1 to f3, f=f1+f2+f3. Also, a1+a2+b+c+d+e+f=1.0.

On the other hand, the base polymer used in the negative photoresist does not necessarily have an acid labile group. Examples of such a base polymer include those containing repeating units b, and further including repeating units c, d, e, and/or f as necessary. The content ratio of these repeating units is preferably 0<b≦1.0, 0≦c≦0.9, 0≦d≦0.8, 0≦e≦0.8, and 0≦f≦0.5, preferably 0.2≦b≦1.0, 0≦c ≦0.8, 0≦d≦0.7, 0≦e≦0.7, and 0≦f≦0.4 are more preferable, 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. Also, b+c+d+e+f=1.0.

In order to synthesize the aforementioned base polymer, for example, the monomer given the aforementioned repeating unit can be added to an organic solvent, and a radical polymerization initiator can be added, followed by heating polymerization.

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

When copolymerizing monomers containing hydroxyl groups, the hydroxyl groups can be pre-substituted with acetal groups such as ethoxyethoxy groups, which are easily deprotected by acid, and deprotected with weak acid and water after polymerization. It is first substituted with acetyl, methyl acetyl, trimethyl acetyl, etc., and then undergoes alkaline hydrolysis after polymerization.

When hydroxystyrene and hydroxyvinylnaphthalene are copolymerized, hydroxystyrene and hydroxyvinylnaphthalene can be used instead of acetoxystyrene and acetoxyvinylnaphthalene. After polymerization, the alkali hydrolysis is carried out to make The acetoxy group is deprotected and becomes hydroxystyrene and hydroxyvinylnaphthalene.

Ammonia water, triethylamine, etc. can be used as the base for alkaline hydrolysis. In addition, the reaction temperature is preferably -20 to 100°C, more preferably 0 to 60°C. The reaction time is preferably 0.2 to 100 hours, more preferably 0.5 to 20 hours.

In the case of gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent for the aforementioned base polymer, the polystyrene conversion weight average molecular weight (Mw) is preferably 1,000 to 500,000, 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 tailing is likely to occur after pattern formation.

In addition, when the molecular weight distribution (Mw/Mn) of the aforementioned base polymer is wide, because of the presence of low-molecular-weight and high-molecular-weight polymers, foreign matter may appear on the pattern after exposure, or the shape of the pattern may deteriorate. As the pattern rule 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 1.0-2.0, especially 1.0-1.5. Narrow dispersion is better.

The aforementioned base polymer may also contain two or more polymers having different composition ratios, Mw, and Mw/Mn. In addition, within a range that does not impair the effect of the present invention, the aforementioned base polymer may contain a polymer other than the aforementioned polymer, but it is preferably not contained.

[Acid Generator] The photoresist material 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 material or a chemically amplified negative photoresist material. Thereby, it becomes a photoresist material with higher sensitivity, and each characteristic is better, and it becomes extremely useful. In addition, when the base polymer contains the repeating unit f, that is, when the base polymer contains an acid generator, the additive type acid generator may not be included.

The aforementioned additive acid generators are, for example, compounds that generate acid in response to active light or radiation (photoacid generators). The photoacid generator may be any compound that generates acid due to high-energy ray irradiation, and is preferably one that generates sulfonic acid, imidic acid or methylated acid. Ideal photoacid generators include sulfonium salt, iodonium salt, sulfodiazomethane, N-sulfonyloxyimide, oxime-O-sulfonate type acid generator and the like. Specific examples of the photoacid generator include those described in paragraphs [0122] to [0142] of JP 2008-111103 A.

Moreover, it is also suitable to use the photoacid generator represented by the following formula (1). [化71]

In formula (1), R ¹⁰¹ , R ^102, and R ¹⁰³ are each independently a monovalent hydrocarbon group having 1 to 20 carbon atoms that may contain a hetero atom. Furthermore, 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 monovalent hydrocarbon group may be linear, branched, or cyclic any one of the described R ^a3 and the specific examples thereof include in the formula (Aa) in the R ^a1 ~ are the same as those in the foregoing.

As the cation of the alumium salt represented by the formula (1), the same as the alumnium cation represented by the formula (Aa) can be mentioned.

In formula (1), X ^- is an anion selected from the following formulas (1A) to (1D). [化72]

In the formula (1A), R ^fa is a fluorine atom or a monovalent hydrocarbon group with 1 to 40 carbon atoms 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 the formula (1A'), R ¹⁰⁴ is a hydrogen atom or a trifluoromethyl group, preferably a trifluoromethyl group. R ¹⁰⁵ is a monovalent hydrocarbon group with 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., more preferably, an oxygen atom. Regarding the aforementioned monovalent hydrocarbon group, considering the viewpoint of obtaining high resolution in the formation of fine patterns, those with 6 to 30 carbon atoms are particularly preferred. 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 sec-butyl. , Tert-butyl, pentyl, neopentyl, cyclopentyl, hexyl, heptyl, 2-ethylhexyl, nonyl, undecyl, tridecyl, pentadecyl, heptadecyl, icosyl Straight-chain or branched alkyl groups; cyclohexyl, 1-adamantyl, 2-adamantyl, 1-adamantylmethyl, norbornyl, norbornylmethyl, tricyclodecyl, four 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, etc. Moreover, as for the monovalent hydrocarbon group containing heteroatoms, tetrahydrofuranyl, methoxymethyl, ethoxymethyl, methylthiomethyl, acetamidomethyl, trifluoroethyl, (2- Methoxyethoxy) methyl, acetoxymethyl, 2-carboxy-1-cyclohexyl, 2-oxopropyl, 4-oxo-1-adamantyl, 3-oxo Cyclohexyl, etc. In addition, part of the hydrogen atoms of these groups may be substituted with heteroatom-containing groups such as oxygen atoms, sulfur atoms, nitrogen atoms, halogen atoms, or part of the carbon atoms of these groups may be substituted with oxygen atoms, sulfur Atom, nitrogen atom and other heteroatom groups, as a result, may also contain hydroxyl, cyano, carbonyl, ether bond, ester bond, sulfonate bond, carbonate bond, lactone ring, sultone ring, carboxylic anhydride, Haloalkyl, etc.

For the synthesis of a salt containing the anion represented by the formula (1A'), see Japanese Patent Application Publication No. 2007-145797, Japanese Patent Application Publication No. 2008-106045, Japanese Patent Application Publication No. 2009-7327, and Japanese Patent Application Publication 2009- for details. Bulletin No. 258695, etc. In addition, the aqua salt described in Japanese Patent Application Publication No. 2010-215608, Japanese Patent Application Publication No. 2012-41320, Japanese Patent Application Publication No. 2012-106986, Japanese Patent Application Publication No. 2012-153644, etc. are also suitable for use.

As for the anion represented by the formula (1A), the following can be listed but not limited thereto. Also, 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 monovalent hydrocarbon group having 1 to 40 carbon atoms that may contain a hetero atom. The aforementioned monovalent hydrocarbon group may be any of linear, branched, and cyclic, and specific examples thereof can be the same as those described in the description of R ¹⁰⁵ . R ^fb1 and R ^{fb2 are} preferably a fluorine atom or a linear fluorinated alkyl group having 1 to 4 carbon atoms. Moreover, 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 group obtained by bonding ^{fb2 to} each other is preferably fluorinated ethylene or fluorinated propylene.

In formula (1C), R ^fc1 , R ^fc2 and R ^fc3 are each independently a fluorine atom, or a monovalent hydrocarbon group with 1 to 40 carbon atoms that may contain a hetero atom. The aforementioned monovalent hydrocarbon group may be any of linear, branched, and cyclic, and specific examples thereof can be the same as those described in the description of R ¹⁰⁵ . R ^fc1 , R ^fc2 and R ^{fc3 are} preferably a fluorine atom or a linear fluorinated alkyl group having 1 to 4 carbon atoms. Moreover, 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 bonding ^{fc2 to} each other is preferably fluorinated ethylene or fluorinated propylene.

In the formula (1D), R ^fd is a monovalent hydrocarbon group with 1 to 40 carbon atoms that may contain a hetero atom. The aforementioned monovalent hydrocarbon group may be any of linear, branched, and cyclic, and specific examples thereof can be the same as those described in the description of R ¹⁰⁵ .

For the synthesis of a salt containing the anion represented by formula (1D), see Japanese Patent Application Publication No. 2010-215608 and Japanese Patent Application Publication No. 2014-133723 for details.

The anions represented by the formula (1D) can be exemplified as follows but are not limited to these. [化78]

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

In addition, it is also preferable to use the photoacid generator represented by the following formula (2). [化79]

In the formula (2), R ²⁰¹ and R ²⁰² are each independently a monovalent hydrocarbon group with 1 to 30 carbon atoms which may contain a hetero atom. R ²⁰³ is a divalent hydrocarbon group with 1 to 30 carbon atoms which may contain a hetero atom. ^Furthermore , any two of R ²⁰¹ , R ²⁰² and R ²⁰³ may also be bonded to each other and form a ring with the sulfur atom to which they are bonded. L ^A is a single bond, an ether bond, or may contain a carbon number of 1 to 20 hetero atoms of the divalent hydrocarbon group. 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 of 0-3.

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

The aforementioned divalent hydrocarbon group may be any of linear, branched, and cyclic, and specific examples thereof include methylene, ethylene, 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 linear or branched alkanediyl groups ; Divalent saturated cyclic hydrocarbon groups such as cyclopentanediyl, cyclohexanediyl, norbornanediyl, adamantanediyl; unsaturated cyclic divalent hydrocarbon groups such as phenylene and naphthylene, etc. In addition, part of the hydrogen atoms of these groups may be substituted with alkyl groups such as methyl, ethyl, propyl, n-butyl and tertiary butyl, and part of the hydrogen atoms of these groups may be substituted with oxygen-containing atoms , Sulfur atoms, nitrogen atoms, halogen atoms and other heteroatom groups, or a part of the carbon atoms of these groups can also be substituted with oxygen atoms, sulfur atoms, nitrogen atoms and other heteroatom groups, the result can also contain hydroxyl, Cyano groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sultone rings, carboxylic anhydrides, haloalkyl groups, etc. The aforementioned hetero atom is preferably an oxygen atom.

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

In the formula (2 '), L ^A as previously described. 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 monovalent hydrocarbon group with 1 to 20 carbon atoms that may contain a hetero atom. The aforementioned monovalent hydrocarbon group may be any of linear, branched, and cyclic, and specific examples thereof can be the same as those described in the description of R ¹⁰⁵ . x and y are each independently an integer of 0-5, and z is an integer of 0-4.

The photoacid generator represented by the formula (2) can be exemplified as follows but not limited to these. Also, in the following formula, R is the same as described above, and Me is methyl. [化81]

[化82]

[化83]

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

Moreover, as for the aforementioned photoacid generator, a sulphur salt or an iodonium salt having an anion containing an iodine atom can also be used. Examples of such salts include sulfonic acid salts and iodonium salts of iodinated benzyloxy-containing fluorinated sulfonic acids 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 amino group, or may also contain a fluorine atom, chlorine Atom, bromine atom, hydroxyl, amino or alkoxy alkyl group with 1 to 20 carbons, alkoxy with 1 to 20 carbons, alkoxycarbonyl with 2 to 20 carbons, and with 2 to 20 carbons An oxy group or an alkylsulfonyloxy group with 1 to 4 carbon atoms, or -NR ⁴⁰⁷ -C(=O)-R ⁴⁰⁸ or -NR ⁴⁰⁷ -C(=O)-OR ⁴⁰⁸ , where R ⁴⁰⁷ is a hydrogen atom, Or it may contain a halogen atom, a hydroxyl group, an alkoxy group, an acyl group or an acyloxy group with a carbon number of 1 to 6; R ⁴⁰⁸ is an alkyl group with 1 to 16 carbons, an alkenyl group with 2 to 16 carbons, Or the aryl group having 6 to 12 carbons 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 divalent linking group with 1 to 20 carbons, and when r is 2 or 3, it is a trivalent or tetravalent linking group with 1 to 20 carbons. The linking group may also Contains oxygen atom, sulfur atom or nitrogen atom.

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 monovalent hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom. ^Furthermore , 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 monovalent hydrocarbon group may be linear, branched, or cyclic of any one, and specific examples thereof include in the formula (Aa) in the R ^a1 ~ R ^a3 and the description of those for the same person.

r is an integer of 1-3. s is an integer of 1-5. t is an integer of 0-3.

In addition, the aforementioned alkyl group, alkoxy group, alkoxycarbonyl group, acyloxy group, alkylsulfonyloxy group, alkenyl group and acyl group may be any of linear, branched, and cyclic.

In addition, as for the sulfonium salt or the sulfonium salt with an anion containing an iodine atom, the sulfonium salt or the sulfonium salt of a fluorinated sulfonic acid containing an iodinated benzene ring represented by the following formula (3-3) or (3-4) . [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 carbons, an acyl group or an oxy group having 2 to 20 carbons, and a fluorine atom , A chlorine atom, a bromine atom, an amino group, or an alkoxycarbonyl group substituted for the amino group.

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

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 monovalent hydrocarbon group of 1 to 20 carbons which may 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 monovalent hydrocarbon group may be linear, branched, or cyclic of any one, and specific examples thereof include in the formula (Aa) in the R ^a1 ~ R ^a3 and the description of those for the same person.

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

In addition, the aforementioned alkyl group, alkoxy group, acyl group, acyloxy group, and alkenyl group may be any of linear, branched, and cyclic.

As the cation of the alumium salt represented by the formulas (3-1) and (3-3), the same as the alumium cation represented by the formula (Aa) as described above can be mentioned. In addition, as the cation of the iodonium salt represented by the formulas (3-2) and (3-4), the same as the iodonium cation represented by the formula (Ab) can be mentioned.

Examples of the anion portion of the onium salt represented by the formulas (3-1) to (3-4) include the following, but are not limited to them. [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]

[化99]

[化100]

[化101]

[化102]

[化103]

[化104]

[化105]

[化106]

[化107]

Moreover, as for the aforementioned photoacid generator, a sulphur salt or an iodonium salt having an anion containing a bromine atom can also be used. Examples of the bromine atom-containing anion include those in which the iodine atom is substituted with a bromine atom in the formulas (3-1) to (3-4). In addition, as a specific example, an iodine atom in the anion containing an iodine atom may be substituted with a bromine atom.

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

[Other ingredients] In addition to the aforementioned components, organic solvents, surfactants, dissolution inhibitors, cross-linking agents, etc. are appropriately combined and blended according to the purpose to form a positive photoresist material and a negative photoresist material. In the exposed part, the aforementioned basic polymer The substance accelerates the dissolution rate of the developer due to the catalyst reaction, so it can become a positive photoresist material and a negative photoresist material with extremely high sensitivity. In this case, the dissolution contrast and resolution of the photoresist film are high, there is an exposure margin, and the processing adaptability is excellent. The pattern shape after exposure is good, and it can especially inhibit acid diffusion, so the density difference is small, so it is practical High, very effective as a photoresist material for ultra LSI.

As for the aforementioned organic solvents, ketones such as cyclohexanone, cyclopentanone, methyl-2-n-pentyl ketone and the like described in paragraphs [0144] to [0145] of JP 2008-111103 A, 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 acetic acid Ester, ethyl lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, t-butyl acetate, t-butyl propionate, propylene glycol mono Tertiary butyl ether acetate and other esters, γ-butyrolactone and other lactones, and mixed solvents of these. These solvents can be used individually by 1 type or in mixture of 2 or more types.

In the photoresist material of the present invention, the content of the aforementioned 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 JP 2008-111103 A. By adding a surfactant, the coating properties of the photoresist material can be improved or controlled. Surfactant can be used individually by 1 type or in combination of 2 or more types. In the photoresist material of the present invention, the content of the aforementioned surfactant is preferably 0.0001 to 10 parts by mass relative to 100 parts by mass of the base polymer.

In the case of positive photoresist materials, by blending a dissolution inhibitor, the difference in dissolution speed between the exposed part and the unexposed part can be increased, and the resolution can be better. On the other hand, in the case of a negative photoresist, a negative pattern can be obtained by adding a crosslinking agent to reduce the dissolution rate of the exposed part.

As for the aforementioned dissolution inhibitor, the molecular weight is preferably 100 to 1,000, more preferably 150 to 800, and the hydrogen atom of the phenolic hydroxyl group is a compound containing two or more phenolic hydroxyl groups in the molecule. In terms of the ratio of 0-100 mol%, the compound is substituted into an acid-labile group, or the hydrogen atom of the carboxyl group of the compound containing a carboxyl group in the molecule is substituted into an acid at an average ratio of 50-100 mol% on the whole Unstable compound. Specifically, bisphenol A, ginseng phenol, phenol phenolphthalein, cresol novolac, naphthalene carboxylic acid, adamantane carboxylic acid, hydroxy group of cholic acid, and carboxyl group hydrogen atoms are substituted into acid labile compounds, for example, : Recorded in paragraphs [0155] ~ [0178] of JP 2008-122932 A.

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

The aforementioned crosslinking agent includes epoxy compounds, melamine compounds, guanamine compounds, and glycoluril compounds substituted with at least one group selected from methylol, alkoxymethyl and oxymethyl Or urea compounds, isocyanate compounds, azide compounds, compounds containing double bonds such as alkenyl ether groups, etc. They can be used as additives, and can also be introduced into polymer side chains as pendant groups. In addition, hydroxyl-containing compounds can also be used as crosslinking agents. A crosslinking agent can be used individually by 1 type or in combination of 2 or more types.

Regarding the aforementioned epoxy compounds, ginseng (2,3-epoxypropyl) isocyanurate, trimethylolmethane triglycidyl ether, trimethylolpropane triglycidyl ether, triglycidyl Hydroxyethyl ethane triglycidyl ether and so on.

As for the aforementioned melamine compounds, hexamethylol melamine, hexamethoxymethyl melamine, and hexamethylol melamine are compounds obtained by methoxymethylation of 1 to 6 methylol groups or mixtures thereof, Hexamethoxyethyl melamine, hexamethyloloxymethyl melamine, hexamethylol melamine, a compound obtained by methylation of 1 to 6 methylol groups of hexamethylol melamine, or a mixture thereof.

Regarding guanamine compounds, tetramethylolguanamine, tetramethoxymethylguanamine, and tetramethylolguanamine are methoxymethylated compounds of 1 to 4 methylol groups. Or mixtures thereof, tetramethoxyethylguanamine, tetrahydroxyguanamine, tetramethylolguanamine, a compound obtained by methylation of 1 to 4 hydroxymethyl groups of tetramethylolguanamine with hydroxymethyl, or a mixture thereof.

As far as glycoluril compounds are concerned, tetramethylol glycoluril, tetramethoxy glycoluril, tetramethoxymethyl glycoluril, and tetramethylol glycoluril of 1 to 4 methylol groups can be listed. Compounds or mixtures obtained by methylation, compounds or mixtures obtained by methylation of 1 to 4 methylol groups of tetramethylol glycoluril with oxo groups, etc. As far as urea compounds are concerned, tetramethylolurea, tetramethoxymethylurea, and tetramethylolurea are compounds obtained by methoxymethylation of 1 to 4 methylol groups or mixtures thereof, Tetramethoxyethyl urea and so on.

The isocyanate compound includes tolylylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, cyclohexane diisocyanate, and the like.

As for the azide compound, 1,1'-biphenyl-4,4'-bisazide, 4,4'-dumb methyl bisazide, 4,4'-oxybisazide Nitride, etc.

Examples of compounds containing alkenyl ether groups 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 glycol trivinyl ether , Neopentyl erythritol tetravinyl ether, sorbitol tetravinyl ether, sorbitol pentavinyl ether, trimethylolpropane trivinyl ether, etc.

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

The photoresist material of the present invention can also be blended with quenchers other than the aforementioned sulfonamide containing iodinated benzene ring (hereinafter referred to as other quenchers). The aforementioned quencher can include conventional basic compounds. As far as conventional basic compounds are concerned, there can be listed 1, 2, 3 aliphatic amines, mixed amines, aromatic amines, heterocyclic amines, nitrogen-containing compounds with carboxyl groups, and sulfonated amines. Nitrogen-containing compounds with hydroxyl groups, nitrogen-containing compounds with hydroxyl groups, nitrogen-containing compounds with hydroxyphenyl groups, alcoholic nitrogen-containing compounds, amides, imines, urethanes, etc. In particular, the first, second, and third amine compounds described in paragraphs [0146] to [0164] of JP 2008-111103 A, especially having a hydroxyl group, ether bond, ester bond, lactone ring, cyano group, sulfonic acid An ester bond compound or a compound having a urethane group described in Japanese Patent No. 3790649 is preferable. By adding such a basic compound, for example, the diffusion rate of the acid in the photoresist film can be more suppressed, or the shape can be corrected.

In addition, other quenchers include onium salts such as α-position unfluorinated sulfonic acids and carboxylic acid salts, iodonium salts, and ammonium salts, which are described in JP 2008-158339 A. Alpha-fluorinated sulfonic acid, imidic acid or methylated acid is necessary to deprotect the acid-labile group of carboxylic acid esters. By exchanging the salt with the non-fluorinated onium salt at the alpha position, it will release Sulfonic acid or carboxylic acid that is not fluorinated at the α position. The unfluorinated sulfonic acid and carboxylic acid at the α position will not cause deprotection reaction, so they act as quenchers.

Other quenchers include polymer quenchers described in JP 2008-239918 A. It improves the rectangularity of the photoresist after patterning by aligning the surface of the photoresist after coating. The polymer 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 soak exposure is used.

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

The photoresist material of the present invention can also be blended with a water repellency enhancer for improving the water repellency of the photoresist surface after spin coating. The aforementioned water repellency enhancer can be used without the top coat. The aforementioned water repellency enhancer is preferably a polymer compound containing a fluorinated alkyl group, a polymer compound containing a 1,1,1,3,3,3-hexafluoro-2-propanol residue with a specific structure, etc. Examples such as Japanese Patent Application Publication No. 2007-297590 and Japanese Patent Application Publication No. 2008-111103 are more desirable. The aforementioned water repellency enhancer needs to be dissolved in an organic solvent developer. The aforementioned specific water repellency enhancer with 1,1,1,3,3,3-hexafluoro-2-propanol residues has good solubility in the developer. As far as the water repellency enhancer is concerned, a polymer compound containing repeating units containing amine groups and amine salts has a high effect on preventing acid from evaporating in PEB and preventing poor openings of the hole pattern after development. The water repellency enhancer can be used singly or in combination of two or more. In the photoresist material of the present invention, the content of the water repellency 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.

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

[Pattern Formation 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 coated on the substrates (Si, SiO ₂ , SiN, On SiON, TiN, WSi, BPSG, SOG, organic anti-reflective film, etc.) or mask circuit manufacturing substrates (Cr, CrO, CrON, MoSi ₂ , SiO ₂ etc.), the coating film thickness is 0.01～2.0μm . It is preferably pre-baked on a hot plate under the conditions of 60 to 150°C for 10 seconds to 30 minutes, and more preferably under the conditions of 80 to 120°C for 30 seconds to 20 minutes. Secondly, use high-energy rays such as ultraviolet, extreme ultraviolet, EB, EUV, X-rays, soft X-rays, excimer lasers, γ-rays, synchrotron radiation, etc., through a predetermined mask or directly expose the target pattern. The exposure is preferably 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 performed on the hot plate at 60-150°C for 10 seconds to 30 minutes, and more preferably at 80-120°C for 30 seconds to 20 minutes.

PEB can be done or not. Especially in the case of the anion-bound PAG polymer containing the aforementioned repeating unit f2 or f3, sulfonic acid is generated due to exposure, and alkali solubility is improved. Therefore, even if PEB is not performed, the exposed part will still be dissolved in alkali. If PEB is not performed, the blur of the image due to acid diffusion will be eliminated, and finer pattern formation can be expected than when PEB is performed.

Without PEB, the deprotection reaction caused by acid will not occur, so the photoresist material of the present invention functions as a non-chemically amplified photoresist material. In this case, the dissolution contrast is low, and thus the film loss of the pattern and the residual film in the pitch portion will occur after development. In the case of non-chemically amplified photoresist materials, how to make the dissolved contrast better becomes the key point.

When an anion-bound PAG polymer containing the aforementioned repeating unit f2 or f3 produces α-fluorosulfonic acid due to exposure, the solubility to alkaline developers is improved, but by adding an onium salt that is not fluorinated at the α position, and It occurs salt exchange, thus inhibiting the production of α-fluorosulfonic acid. In addition, if the exposure dose is increased, the onium salt of the sulfonic acid or carboxylic acid that is not fluorinated at the α position is decomposed, and the alkali solubility is improved. That is, the dissolution inhibitory property is improved in the area with a small exposure amount, and the dissolution promotion property is improved in the area with a large exposure amount, and thus the contrast is improved. The ion exchange reaction is fast and proceeds at room temperature, so PEB is not required. The onium salt represented by the formula (A) is also a salt with a weaker acid than α-fluorosulfonic acid and undergoes the same ion exchange, so the contrast is higher than when PEB is not performed.

Furthermore, by using 0.1-10 mass%, preferably 2-5 mass% of tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide (TEAH), tetrapropylammonium hydroxide (TPAH) , Tetrabutylammonium hydroxide (TBAH) and other alkaline aqueous solution developer, in 3 seconds to 3 minutes, preferably 5 seconds to 2 minutes, dip method, immersion (puddle) method, spray ( The development of conventional methods such as spray) method will dissolve the illuminated part in the developing solution, and the unexposed part will not dissolve, forming the target positive pattern on the substrate. The negative type photoresist is the opposite of the positive type photoresist, that is, the illuminated part is insoluble in the developer, and the unexposed part is dissolved. In addition, the photoresist material of the present invention is particularly suitable for the fine patterning of KrF excimer lasers, ArF excimer lasers, EB, EUV, X-rays, soft X-rays, gamma rays, and 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 implement negative development using organic solvent development to obtain a negative pattern. The developer used at this time can include 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutyl ketone, methyl Cyclohexanone, acetophenone, methylacetophenone, propyl acetate, butyl acetate, isobutyl acetate, pentyl acetate, butenyl acetate, isoamyl acetate, propyl formate, butyl formate, Isobutyl formate, pentyl 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, pentyl lactate, isoamyl lactate, methyl 2-hydroxyisobutyrate, 2-hydroxyisobutyrate Ethyl, methyl benzoate, ethyl benzoate, phenyl acetate, benzyl acetate, methyl phenyl acetate, benzyl formate, phenyl ethyl formate, methyl 3-phenylpropionate, benzyl propionate , Ethyl phenylacetate, 2-phenylethyl acetate, etc. These organic solvents can be used individually by 1 type or in mixture of 2 or more types.

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. For such solvents, it is preferable to use alcohols with 3 to 10 carbons, ether compounds with 8 to 12 carbons, alkanes, alkenes, alkynes, and aromatic solvents with 6 to 12 carbons.

Specifically, for alcohols with 3 to 10 carbon atoms, n-propanol, isopropanol, 1-butanol, 2-butanol, isobutanol, tert-butanol, 1-pentanol, 2 -Pentanol, 3-pentanol, tertiary 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.

For ether compounds with 8 to 12 carbon atoms, di-n-butyl ether, diisobutyl ether, di-second butyl ether, di-n-pentyl ether, di-isoamyl ether, di-n-pentyl ether, and di-third pentyl ether Ether, di-n-hexyl ether, etc.

For alkanes with 6 to 12 carbons, hexane, heptane, octane, nonane, decane, undecane, dodecane, methylcyclopentane, dimethylcyclopentane, cyclopentane Hexane, methylcyclohexane, dimethylcyclohexane, cycloheptane, cyclooctane, cyclononane, etc. Examples of olefins having 6 to 12 carbon atoms include hexene, heptene, octene, cyclohexene, methylcyclohexene, dimethylcyclohexene, cycloheptene, and cyclooctene. Examples of alkynes having 6 to 12 carbon atoms include hexyne, heptyne, and octyne.

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

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

The developed hole pattern and trench pattern can also be shrunk by heat flow, RELACS technology or DSA technology. A shrinking agent is coated on the hole pattern, and the acid catalyst is diffused from the photoresist layer during baking, and crosslinking of the shrinking agent occurs on the surface of the photoresist, so that the shrinking agent is attached to the sidewall 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 reduce the hole pattern. [Example]

The synthesis examples, examples and comparative examples are given below to illustrate 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-triiodobenzamide triphenylsulfonium (aluminium salt 1) [Chemical 108]

After heating a mixed solution 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 sulfite chloride was added dropwise. After stirring at 60°C for 21 hours, it was concentrated under reduced pressure to remove chloroform and unreacted thiol chloride. 500 g of hexane was added to the concentrated liquid and stirred for 1 hour to precipitate a solid. The obtained solid was separated by filtration and washed with hexane once to obtain 97 g of 2,3,5-triiodobenzyl chloride solid. To a mixture of 2.24 g of trifluoromethanesulfonamide, 3.73 g of potassium carbonate, and 40 g of acetonitrile, 10.1 g of the aforementioned 2,3,5-triiodobenzyl chloride was added, and the mixture was stirred at room temperature for 15 hours. After adding 120 g of pure water dropwise to quench the reaction, 6.74 g of triphenyl sulfonic acid 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 tert-butyl methyl ether was added to the obtained solution and stirred, and then the supernatant was removed. The residue was concentrated under reduced pressure to obtain 10.5 g of the target N-[(trifluoromethyl)sulfonyl]-2,3,5-triiodobenzamide triphenylsulfonate (salt 1) oil Material (yield 78%).

The IR spectrum data of sulfonium 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 Figure 1 and Figure 2 respectively. In addition, a trace amount of residual solvent (tert-butyl methyl ether and water) was observed in 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 examples 1-2～1-24] Synthesis of sulphur salt 2～15, iodonium salt 1～3 and ammonium salt 1～6 The structures of the sulfonamide salts 1-15, the iodonium salts 1-3 and the ammonium salts 1-6 containing the iodinated benzene ring used in the photoresist material of the present invention are arranged as follows. The sulfonium salt 2-15 and the sulfonium salt 1 to 3 are the same as in Synthesis Example 1-1. The sulfonamide containing the iodinated benzene ring is given the following anions, and the sulfonium methanesulfonate salt and chlorine are given the following cations. Synthesized by ion exchange of sulfide or iodonium chloride. Ammonium salt 1 and 2 are synthesized by neutralizing reaction of sulfonamide containing iodinated benzene ring and 4 grade ammonium hydroxide given the following anions. Ammonium salt 3 ~6 is synthesized by neutralizing the sulfonamide containing iodinated benzene ring with the tertiary amine compound given 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 THF solvent, precipitated out of methanol, and then washed repeatedly with hexane After separation and drying, the base polymer (polymer 1 to 5) of the following composition 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 1-30, Comparative Examples 1-7] Dissolve 100 ppm of FC-4430 produced by 3M as a surfactant in a solvent, dissolve each component into a solution according to the composition shown in Tables 1 to 3, and filter with a 0.2μm size filter to prepare a photoresist material.

In Tables 1 to 3, the components are 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) [Chemical 116]

[化117]

Comparison quencher 1～6 (refer to the following structural formula) [化118]

[EB Exposure Evaluation] The photoresist materials shown in Tables 1 to 3 were spin-coated on the Si substrate with the anti-reflective film DUV-62 manufactured by Nissan Chemical Industry Co., Ltd. with a film thickness of 60nm, and pre-baked at 105°C for 60 seconds using a hot plate , Make a photoresist film with a thickness of 50nm. It was exposed using an EB drawing device (ELS-F125, acceleration voltage 125kV) manufactured by Elionix, PEB was performed on a hot plate at the temperature described in Tables 1 to 3 for 60 seconds, and developed with a 2.38% by mass TMAH aqueous solution for 30 seconds. In Examples 1-13, 15-30 and Comparative Examples 1 to 6, a positive photoresist pattern (hole pattern with a size of 24nm) was formed, and a negative photoresist pattern (dot pattern with a size of 24nm) was formed in Example 14 and Comparative Example 7. ). Using Hitachi Advanced Technology Co., Ltd.'s length measuring SEM (CG5000), measure the exposure when the hole or dot is formed at 24nm, and define it as sensitivity. Also, measure the diameter of the hole or dot at this time at 50 dots 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.

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

Claims (15)

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

In the formula, R ¹ is a hydrogen atom, a hydroxyl group, an alkyl group with 1 to 6 carbons, an alkoxy group with 1 to 6 carbons, an acyloxy group with 2 to 7 carbons, and an alkoxycarbonyl group with 2 to 7 carbons. , Alkylsulfonyloxy group with 1 to 4 carbon atoms, fluorine atom, chlorine atom, bromine atom, amino 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 group, alkoxy group, acyloxy group, alkoxycarbonyl group and alkylsulfonyloxy group may be substituted with halogen atoms; R ^1A is hydrogen Atom, or an alkyl group with 1 to 6 carbons; R ^1B is an alkyl group with 1 to 6 carbons, or an alkenyl group with 2 to 8 carbons; R ² is an alkyl group with 1 to 10 carbons, or 6 ~10 aryl, part or all of its hydrogen atoms can also be substituted with amine, nitro, cyano, alkyl with 1 to 12 carbons, alkoxy with 1 to 12 carbons, and 2 to 12 carbons The alkoxycarbonyl group, the acyl group with 2 to 12 carbons, the alkylcarbonyloxy group with 2 to 12 carbons, the hydroxyl group, or the halogen atom; X ¹ is a single bond or a divalent linking group with 1 to 20 carbons , May also contain ether bond, carbonyl group, ester bond, amide bond, or sultone ring; m and n are integers conforming to 1≦m≦5, 0≦n≦4, and 1≦m+n≦5; M ⁺ is a cation represented by the following formula (Aa), an iodonium 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 monovalent hydrocarbon group with 1 to 20 carbon atoms that may also contain heteroatoms; in addition, any two 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 with 1 to 20 carbon atoms that may also contain heteroatoms; R ^a6 ~R ^a9 each It is independently a hydrogen atom or a monovalent hydrocarbon group with 1 to 24 carbon atoms, and may also contain halogen atoms, hydroxyl groups, carboxyl groups, ether bonds, ester bonds, thiol groups, thioester bonds, thiocarbonyl ester bonds, and dithioester bonds , Amine, nitro, sulfonyl or ferrocene; R ^a6 and R ^a7 can also bond with 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 , They can also be bonded to each other and form a spiro ring together with the nitrogen atom to which they are bonded, or R ^a8 and R ^a9 can 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 with 1 to 16 carbon atoms; R ^a10 and R ^a11 may also be bonded to each other and form a ring with the carbon atom and nitrogen atom to which they are bonded. The ring may also contain double Bond, oxygen atom, sulfur atom or nitrogen atom. For example, the photoresist material of item 1 in the scope of patent application, where m is an integer conforming to 2≦m≦4. For example, the photoresist material of item 1 or 2 of the scope of patent application further contains acid generators that generate sulfonic acid, imine acid or methylated acid. For example, the photoresist material of item 1 or 2 of the scope of patent application contains organic solvent. For example, the photoresist material of item 1 or 2 in the scope of patent application, wherein the base polymer contains the repeating unit represented by the following formula (a1) or the 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 phenylene group or a naphthylene group, or a linking group with 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 of item 5 in the scope of patent application is a chemically amplified positive photoresist material. For example, the photoresist material of item 1 or 2 in the scope of patent application, wherein the base polymer does not contain acid labile groups. For example, the photoresist material of item 7 in the scope of patent application contains a crosslinking agent. For example, the photoresist material of item 7 in the scope of patent application is a chemically amplified negative photoresist material. For example, the photoresist material of item 1 or 2 in the scope of patent application, wherein the base polymer further contains at least one of the repeating units represented by the following formulas (f1)~(f3);

In the formula, R ^{A is} each independently a hydrogen atom or a methyl group; Z ¹ is a single bond, a phenylene group, -OZ ¹¹ -, -C(=O)-OZ ¹¹ -or -C(=O)-NH- Z ¹¹ -, Z ¹¹ is alkanediyl with 1 to 6 carbons, alkene with 2 to 6 carbons, or phenylene, and may also contain carbonyl, ester bond, ether bond or hydroxyl; 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 with 1 to 12 carbons, and may also contain a carbonyl group, Ester bond or ether bond; Z ³ is a single bond, methylene, ethylene, phenylene, fluorinated phenylene, -C(=O)-OZ ³¹ -or -C(=O)-NH- Z ³¹ -, Z ³¹ is alkanediyl group with 1 to 6 carbon atoms, phenylene group, fluorinated phenylene group, phenylene group substituted by trifluoromethyl, or alkenediyl group with carbon number 2-6 It 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 with 1 to 20 carbon atoms and may also contain a hetero atom; and R Any two 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 not Nucleophilic relative ion. For example, the photoresist material of item 1 or 2 in the scope of patent application further contains surfactant. A pattern forming method includes the following steps: Coating the photoresist material according to any one of items 1 to 11 in the scope of the patent application on the substrate, performing heat treatment to form a photoresist film; exposing the photoresist film to high-energy rays; and using a developer to expose the already exposed The photoresist film is developed. For example, the pattern forming method of item 12 in the scope of the patent application, wherein the high-energy ray is an ArF excimer laser with a wavelength of 193nm or a KrF excimer laser with a wavelength of 248nm. For example, the pattern forming method of item 12 in the scope of patent application, wherein the high-energy rays are electron beams or extreme ultraviolet rays with a wavelength of 3-15 nm. A kind of salt represented by the following formula (B);

In the formula, R ¹ is a hydrogen atom, a hydroxyl group, an alkyl group with 1 to 6 carbons, an alkoxy group with 1 to 6 carbons, an acyloxy group with 2 to 7 carbons, and an alkoxycarbonyl group with 2 to 7 carbons. , Alkylsulfonyloxy group with 1 to 4 carbon atoms, fluorine atom, chlorine atom, bromine atom, amino 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 group, alkoxy group, acyloxy group, alkoxycarbonyl group and alkylsulfonyloxy group may be substituted with halogen atoms; R ^1A is hydrogen Atom, or an alkyl group with 1 to 6 carbons; R ^1B is an alkyl group with 1 to 6 carbons, or an alkenyl group with 2 to 8 carbons; R ² is an alkyl group with 1 to 10 carbons, or 6 ~10 aryl, part or all of its hydrogen atoms can also be substituted with amine, nitro, cyano, alkyl with 1 to 12 carbons, alkoxy with 1 to 12 carbons, and 2 to 12 carbons The alkoxycarbonyl group, the acyl group with 2 to 12 carbons, the alkylcarbonyloxy group with 2 to 12 carbons, the hydroxyl group, or the halogen atom; X ¹ is a single bond or a divalent linking group with 1 to 20 carbons , May also contain ether bond, carbonyl group, ester bond, amide bond, or sultone ring; m and n are integers conforming to 1≦m≦5, 0≦n≦4, and 1≦m+n≦5; R ^a1 to R ^a3 are each independently a halogen atom, or a monovalent hydrocarbon group with 1 to 20 carbon atoms that may also contain heteroatoms; in addition, any two of R ^a1 , R ^a2 and R ^a3 may be bonded to each other They form a ring with the sulfur atom to which they are bonded.

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