KR-102964179-B1 - RESIST COMPOSITION AND PATTERN FORMING PROCESS

Abstract

[Problem] In photolithography using high energy rays, a resist composition having excellent sensitivity, resolution, and LWR, and a method for forming a pattern using the resist composition are provided. [Solution] A resist composition comprising a tin compound represented by the following formula (1) and an organic solvent. (In the formula, R₁A – R₁OA and R₁B – R₁OB are each independently a hydrocarbyl group having 1–20 carbon atoms. R₁1 – R₁4 are each independently a hydrogen atom or a hydrocarbyl group having 1–20 carbon atoms. L₀a1 and L₀a2 are each independently a linker.)

Inventors

• 오하시 마사키
• 다치바나 세이이치로
• 기쿠치 šœ
• 한다 류노스케

Assignees

• 신에쓰 가가꾸 고교 가부시끼가이샤

Dates

Publication Date

20260512

Application Date

20240509

Priority Date

20230512

Claims (7)

1. A resist composition comprising a tin compound represented by the following formula (1) (except for the following formula (M-1)) and an organic solvent. (In the formula, R 1A to R 10A and R 1B to R 10B are each independently hydrocarbyl groups having 1 to 20 carbon atoms. R 11 to R 14 are each independently a hydrogen atom or a hydrocarbyl group having 1 to 20 carbon atoms. L a1 and L a2 are each independently connectors.) (In the formula, Bn is a benzyl group.)
2. A resist composition according to claim 1, wherein L a1 and L a2 are each independently represented by any one of the following formulas (2a) to (2d). (In the equation, dashed lines represent bond losses with Sn.)
3. A resist composition according to claim 1, wherein R 1A to R 10A and R 1B to R 10B are isopropyl groups, n-butyl groups, tert-butyl groups, or benzyl groups.
4. A resist composition comprising a surfactant further comprising, in claim 1.
5. In claim 1, the solvent is cyclohexanone, methyl-2-n-pentyl ketone, 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, diacetone alcohol, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, diethylene glycol dimethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, tert-butyl acetate, cyclohexyl acetate, tert-butyl propionate, propylene glycol monotert-butyl ether acetate, A resist composition comprising γ-butyrolactone, acetic acid, propionic acid, toluene, xylene, cresol, anisole, benzotrifluoride, or a mixture thereof.
6. A pattern forming method comprising: a process of forming a resist film on a substrate using a resist composition described in any one of claims 1 to 5; a process of exposing the resist film to high-energy rays; and a process of developing the exposed resist film using a developer.
7. A pattern forming method according to claim 6, wherein the high-energy line is an electron beam or an extreme ultraviolet beam.

Description

Resist Composition and Pattern Forming Process The present invention relates to a resist composition and a pattern forming method. With the expansion of the IoT market, there is an increasing demand for higher integration, higher speed, and lower power consumption of LSIs, leading to rapid miniaturization of pattern rules. In particular, logic devices are driving this miniaturization. As a cutting-edge miniaturization technology, 10 nm node devices are being mass-produced using double patterning, triple patterning, and quadruple patterning of ArF immersion lithography, and 7 nm node devices are being explored using next-generation extreme ultraviolet (EUV) lithography with a wavelength of 13.5 nm. With the progress of miniaturization, image blurring caused by acid diffusion is becoming a problem (Non-patent Literature 1). It has been suggested that in order to secure resolution in fine patterns after the processing dimension 45 nm generation, control of acid diffusion is important in addition to the improvement of dissolution contrast proposed in the past (Non-patent Literature 2). However, since chemical amplification resist compositions increase sensitivity and contrast through acid diffusion, if one attempts to suppress acid diffusion to the extreme by lowering the post-exposure bake (PEB) temperature or shortening the time, the sensitivity and contrast are significantly reduced. It is effective to suppress acid diffusion by adding an acid-generating agent that generates bulky acid. Therefore, copolymerizing an acid-generating agent of an onium salt having a polymerizable olefin in a polymer has been proposed. However, in the patterning of resist films with processing dimensions of 16 nm or more, it is thought that patterns cannot be formed with chemically amplified resist materials from the perspective of acid diffusion, so the development of non-chemically amplified resist compositions is required. Polymethyl methacrylate (PMMA) can be cited as a material for non-chemical amplification resist compositions. PMMA is a positive type resist material in which the main chain is cut by irradiation with electron beam (EB) or EUV and the molecular weight is reduced, thereby improving solubility in organic solvent developers; however, it has the disadvantage of having low etching resistance and a large amount of outgassing during exposure because it does not have a ring structure. Hydrogensilsesquioxane (HSQ) is a negative-type resist material that becomes insoluble in alkaline developers due to crosslinking through the condensation reaction of silanols generated by EB or EUV irradiation. Additionally, chlorine-substituted calixarene also functions as a negative-type resist material. Since these negative-type resist materials have small molecular sizes prior to crosslinking and thus do not experience blurring due to acid diffusion, they exhibit low edge roughness and very high resolution; consequently, they are utilized as pattern transfer materials to indicate the resolution limit of an exposure device. However, these materials have insufficient sensitivity, requiring further improvement. One factor that makes the development of materials for EUV lithography difficult is the low number of photons in EUV exposure. The energy of EUV is much higher than that of ArF excimer laser light, and the number of photons in EUV exposure is one-fourteenth that of ArF exposure. Furthermore, the dimensions of patterns formed by EUV exposure are less than half those of ArF exposure. For this reason, EUV exposure is susceptible to the effects of photon number non-uniformity. Photon number non-uniformity in the extreme wavelength synchrotron region is a physical phenomenon known as shot noise, and this effect cannot be eliminated. For this reason, so-called stochastics is receiving attention. Although the effects of shot noise cannot be eliminated, discussions are underway on how to reduce them. Due to the effects of shot noise, not only are dimensional uniformity (CDU) and line width roughness (LWR) increased, but a phenomenon in which holes become occluded with a probability of one in a million is also observed. If a hole is blocked, it results in a power failure and the transistor does not operate, which negatively affects the overall performance of the device. As a method to reduce the impact of shot noise on the resist side, an inorganic resist composition with an element that absorbs EUV as a nucleus has been proposed (Patent Document 1). However, although the inorganic resist composition is relatively sensitive, it is not yet sufficient and also has many challenges such as insufficient solubility in solvents for resist, storage stability, and defects. Non-patent document 3 proposes a negative-type resist composition using a tin compound. This is a non-chemically amplified resist with a tin element having high EUV light absorption as the main component. Although it has improved the probability and achieved a certain level o