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CN-115485624-B - Composition for forming resist underlayer film

CN115485624BCN 115485624 BCN115485624 BCN 115485624BCN-115485624-B

Abstract

The present invention addresses the problem of providing a composition for forming a silicon-containing resist underlayer film, which can be used for forming a resist underlayer film by a conventional dry etching method, but also by a wet etching method using a chemical solution such as dilute hydrofluoric acid, buffered hydrofluoric acid, or an alkaline chemical solution, and which is excellent in storage stability and is useful for forming a resist underlayer film having little residue in a dry etching step. A composition for forming a resist underlayer film, which comprises a hydrolysis condensate of a hydrolyzable silane mixture containing a hydrolyzable silane represented by formula (1) and an alkyl trialkoxysilane, wherein the content of the alkyl trialkoxysilane in the hydrolyzable silane mixture is 0 mol% or more and less than 40 mol% based on the total mole number of all hydrolyzable silanes contained in the hydrolyzable silane mixture. (in the formula (1), R 1 is a group bonded to a silicon atom, represents an organic group containing at least 1 group or skeleton selected from the group consisting of succinic anhydride skeleton, vinyl group, phenyl group and isocyanuric acid skeleton, R 2 is a group bonded to a silicon atom, each independently represents an alkyl group or the like which may be substituted, R 3 is a group or atom bonded to a silicon atom, each independently represents an alkoxy group, an aralkyloxy group, an acyloxy group or a halogen atom, a represents 1, b represents an integer of 0 to 2, and 4- (a+b) represents an integer of 1 to 3.) R 1 a R 2 b Si(R 3 ) 4‑(a+b) (1).

Inventors

  • SHIGAKI SHUHEI
  • Shi Qiaoqian
  • Chai Shangen

Assignees

  • 日产化学株式会社

Dates

Publication Date
20260505
Application Date
20210430
Priority Date
20200430

Claims (9)

  1. 1. A composition for forming a resist underlayer film, which comprises a hydrolytic condensate of a hydrolyzable silane mixture comprising a hydrolyzable silane represented by formula (1), an alkyl trialkoxysilane and a hydrolyzable silane represented by formula (2), The content of the alkyltrialkoxysilane in the hydrolyzable silane mixture is 0 mol% or more and less than 40 mol% based on the total mole number of all hydrolyzable silanes contained in the hydrolyzable silane mixture, In the formula (1), the amino acid sequence of the formula (1), R 1 is a group bonded to a silicon atom, represents an organic group containing at least 1 group or skeleton selected from the group consisting of succinic anhydride skeleton, alkenyl group, aryl group and group represented by the following formula (1-2), In the formula (1-2), X 101 represents any one of the groups represented by the following formulas (1-3) to (1-5), and the carbon atom of the ketone group in the following formulas (1-4) and (1-5) is bonded to the nitrogen atom to which R 102 in the formula (1-2) is bonded, In the formulae (1-3) to (1-5), R 103 ～R 107 independently of each other represents a hydrogen atom, an alkyl group which may be substituted, an alkenyl group which may be substituted, or an organic group containing an epoxy group or a sulfonyl group; R 101 independently of one another represents a hydrogen atom, an alkyl group which may be substituted, an alkenyl group which may be substituted, or an organic group containing an epoxy group or a sulfonyl group, R 102 , independently of one another, represents alkylene, hydroxyalkylene, a sulphur bond, i.e. -S-, an ether bond, i.e. -O-, or an ester bond, i.e. -C (=O) -O-, or-O-C (=O) -; R 2 is a group bonded to a silicon atom, independently of each other, represents an alkyl group which may be substituted, a haloalkyl group which may be substituted, or an alkoxyalkyl group which may be substituted, or represents an organic group comprising an epoxy group, an acryl group, a methacryl group, a mercapto group, an amino group, an amide group, an alkoxy group, a sulfonyl group, or a cyano group, or a combination thereof, R 3 is a group or atom bonded to a silicon atom, independently of one another, represents an alkoxy group, an aralkyloxy group, an acyloxy group or a halogen atom, A represents 1, b represents an integer of 0 to 2, 4- (a+b) represents an integer of 1 to 3, In the formula (2), the amino acid sequence of the formula (2), R 4 is a group bonded to a silicon atom, independently of each other, represents an alkyl group which may be substituted, a haloalkyl group which may be substituted, or an alkoxyalkyl group which may be substituted, or represents an organic group comprising an epoxy group, an acryl group, a methacryl group, a mercapto group, an amino group, an amide group, an alkoxy group, a sulfonyl group, or a cyano group, or a combination thereof, R 5 is a group or atom bonded to a silicon atom, and independently represents an alkoxy group, an aralkyloxy group, an acyloxy group, or a halogen atom, C represents an integer of 0 to 3.
  2. 2. The composition for forming a resist underlayer film according to claim 1, wherein R 1 is a group bonded to a silicon atom, and represents an organic group containing at least 1 group or skeleton selected from a succinic anhydride skeleton, a vinyl group, a phenyl group, and an isocyanuric acid skeleton.
  3. 3. The resist underlayer film forming composition according to claim 1 or 2, wherein the content of the compound represented by formula (1) in the hydrolyzable silane mixture is 5 mol% or more based on the total mole number of all hydrolyzable silanes contained in the hydrolyzable silane mixture.
  4. 4. The resist underlayer film forming composition according to claim 3, comprising, as the compound represented by formula (1), a compound in which R 1 represents an organic group containing a succinic anhydride skeleton.
  5. 5. The composition for forming a resist underlayer film according to claim 4, where R 1 in the hydrolyzable silane mixture represents an organic group containing a succinic anhydride skeleton, and the content of the compound represented by formula (1) is 1 mol% or more based on the total number of moles of all hydrolyzable silanes contained in the hydrolyzable silane mixture.
  6. 6. The resist underlayer film forming composition according to claim 1 or 2, which is a composition having a pH of 2 to 5.
  7. 7. A pattern forming method comprising the steps of: Forming an organic underlayer film on a semiconductor substrate; A step of forming a silicon-containing resist underlayer film by applying the resist underlayer film forming composition according to any one of claims 1 to 6 to the organic underlayer film and firing the composition; a step of forming a resist film by applying a resist film-forming composition to the silicon-containing resist underlayer film; Exposing and developing the resist film to obtain a resist pattern; etching the silicon-containing resist underlayer film using the resist pattern as a mask; and etching the organic underlayer film using the patterned silicon-containing resist underlayer film as a mask.
  8. 8. The method for forming a pattern according to claim 7, further comprising a step of removing the silicon-containing resist underlayer film by a wet method using a chemical solution after the step of etching the organic underlayer film.
  9. 9. The pattern forming method according to claim 8, wherein the chemical solution is an alkaline chemical solution.

Description

Composition for forming resist underlayer film Technical Field The present invention relates to a composition for forming a resist underlayer film, which can form a pattern with low unevenness in fine pattern formation, can be easily peeled off by a peeling liquid which does not damage a semiconductor substrate, a coating type organic underlayer film required in a pattern forming step, and a CVD film containing carbon as a main component, and can maintain peelability of a silicon-containing film even after dry etching. Background Conventionally, in the manufacture of semiconductor devices, micromachining has been performed by photolithography using a photoresist. The micromachining is a processing method in which a thin film of a photoresist is formed on a semiconductor substrate such as a silicon wafer, active light such as ultraviolet rays is irradiated on the thin film through a mask pattern on which a pattern of a semiconductor device is drawn, the resultant photoresist pattern is developed, and the substrate is etched as a protective film, whereby fine irregularities corresponding to the pattern are formed on the surface of the substrate. In recent years, the integration of semiconductor devices has been advanced, and the active light used has also tended to be shortened from KrF excimer laser (248 nm) to ArF excimer laser (193 nm). As the wavelength of the active light becomes shorter, the influence of reflection of the active light from the semiconductor substrate becomes a great problem, and a method of providing a resist underlayer film called an antireflection film (BottomAnti-ReflectiveCoating, BARC) between the photoresist and the substrate to be processed is widely used. As the underlayer film between the semiconductor substrate and the photoresist, a film known as a hard mask containing a metal element such as silicon or titanium is used. In this case, the resist and the hard mask have a large difference in their constituent components, and therefore their removal rate by dry etching is greatly dependent on the kind of gas used for dry etching. Further, by appropriately selecting the gas type, the hard mask can be removed by dry etching without a significant decrease in the film thickness of the photoresist. In recent years, in order to achieve various effects, such as an anti-reflection effect, a resist underlayer film is disposed between a semiconductor substrate and a photoresist in the manufacture of semiconductor devices. The composition for the resist underlayer film has been studied so far, but development of a new material for the resist underlayer film is desired in view of the diversity of characteristics and the like required therefor. For example, a composition for forming a film of BPSG (borophosphosilicate glass) containing a coating type structure having a specific silicic acid skeleton, which is a problem of film formation capable of wet etching (patent document 1), and a composition for forming a silicon-containing resist underlayer film having a carbonyl structure, which is a problem of removal of a mask residue after photolithography (patent document 2), are disclosed. Prior art literature Patent literature Patent document 1 Japanese patent laid-open publication 2016-74774 Patent document 2 International publication No. 2018/181989 Disclosure of Invention Problems to be solved by the invention In the most advanced semiconductor device, the multi-layer process is widely used by miniaturization of the ion implantation layer (IMPLANT LAYER), and in general, transfer to the lower layer is sometimes performed by the dry etching in the multi-layer process, and the final processing of the substrate and removal of residues of the mask after the substrate processing, such as a resist film and a lower layer film including a resist lower layer film, are also performed by dry etching and ashing. However, the substrate is not damaged little by dry etching and ashing treatment, and improvement thereof is demanded. The present invention has been made in view of the above circumstances, and an object thereof is to provide a composition for forming a silicon-containing resist underlayer film, which can be used for forming a resist underlayer film which is not only formed by a conventional dry etching method but also can be peeled off by a wet etching method using a chemical solution such as dilute hydrofluoric acid, buffered hydrofluoric acid, or an alkaline chemical solution (alkaline chemical solution), in a processing step of a semiconductor substrate or the like, and further to provide a composition for forming a silicon-containing resist underlayer film, which is excellent in storage stability and is used for forming a resist underlayer film having little residue in a dry etching step. Means for solving the problems As a result of intensive studies to solve the above problems, the present inventors have found that a film obtained from a composition containing a hydrolytic condensate (po