UNDERLAYER FILM-FORMING COMPOSITION AND PATTERN FORMING PROCESS

• US 20140363955A1
• Filed: 06/04/2014
• Published: 12/11/2014
• Est. Priority Date: 06/11/2013
• Status: Active Grant

• Current Assignee: Shin-Etsu Chemical Company Limited
• Original Assignee: Shin-Etsu Chemical Company Limited
• Inventors: Hatakeyama, Jun, Kori, Daisuke, Ogihara, Tsutomu
• Granted Patent: US 10,228,621 B2
• Time in Patent Office: Days
• US Class Current: 438/514
• CPC Class Codes: C08G 8/04 of aldehydes
• CPC Class Codes: C08G 8/08 of formaldehyde, e.g. of formaldehyde formed in situ
• CPC Class Codes: G03F 7/0752 in non photosensitive layers or as additives, e.g. for dry lithography
• CPC Class Codes: G03F 7/09 characterised by structural details, e.g. supports, auxiliary layers supports for printing plates in general B41N
• CPC Class Codes: G03F 7/091 characterised by antireflection means or light filtering or absorbing means, e.g. anti-halation, contrast enhancement
• CPC Class Codes: G03F 7/094 Multilayer resist systems, e.g. planarising layers
• CPC Class Codes: G03F 7/11 having cover layers or intermediate layers, e.g. subbing layers G03F7/091 - G03F7/093, B41N3/03 take precedence
• CPC Class Codes: G03F 7/40 Treatment after imagewise removal, e.g. baking
• CPC Class Codes: H01L 21/0276 using an anti-reflective coating anti-reflective coating for lithography in general G03F7/09
• CPC Class Codes: H01L 21/265 producing ion implantation
• CPC Class Codes: H01L 21/266 using masks H01L21/26586 takes precedence

Abstract

In lithography, a composition comprising a novolak resin comprising recurring units derived from a phenolphthalein, Phenol Red, Cresolphthalein, Cresol Red, or Thymolphthalein is used to form a photoresist underlayer film. The underlayer film is strippable in alkaline water, without causing damage to ion-implanted Si substrates or SiO₂ substrates.

Claims

1. A photoresist underlayer film-forming composition for use in lithography, comprising a novolak resin comprising recurring units of at least one type selected from the group consisting of a substituted or unsubstituted phenolphthalein, Phenol Red, Cresolphthalein, Cresol Red, and Thymolphthalein.

2. The underlayer film-forming composition of claim 1 wherein the recurring units have the general formula (1):

3. The underlayer film-forming composition of claim 1, further comprising an organic solvent.

4. The underlayer film-forming composition of claim 3, further comprising an acid generator and/or crosslinker.

5. A process for forming a pattern in a substrate by lithography, comprising the steps of

applying the underlayer film-forming composition of claim 1 onto a substrate to form an underlayer film,

forming a photoresist film on the underlayer film,

forming a photoresist pattern via exposure and development, and

processing the underlayer film and the substrate with the photoresist pattern serving as mask.

6. A process for forming a pattern in a substrate by lithography, comprising the steps of

applying the underlayer film-forming composition of claim 1 onto a substrate to form an underlayer film,

forming a photoresist film on the underlayer film,

forming a photoresist pattern via exposure and development,

processing the underlayer film with the photoresist pattern serving as mask, and

implanting ions into the substrate.

7. A process for forming a pattern in a substrate by lithography, comprising the steps of

applying the underlayer film-forming composition of claim 1 onto a substrate to form an underlayer film,

forming a silicon-containing intermediate film on the underlayer film,

forming a photoresist film on the intermediate film,

forming a photoresist pattern via exposure and development,

processing the intermediate film with the photoresist pattern serving as mask,

processing the underlayer film with the intermediate film serving as mask, and

processing the substrate with the underlayer film serving as mask.

8. A process for forming a pattern in a substrate by lithography, comprising the steps of

applying the underlayer film-forming composition of claim 1 onto a substrate to form an underlayer film,

forming a silicon-containing intermediate film on the underlayer film,

forming a photoresist film on the intermediate film,

forming a photoresist pattern via exposure and development,

processing the intermediate film with the photoresist pattern serving as mask,

processing the underlayer film with the intermediate film serving as mask, and

implanting ions into the substrate with the underlayer film serving as mask.

9. The pattern forming process of claim 5, further comprising the step of stripping the underlayer film in alkaline water before or after the step of processing the substrate.

10. The pattern forming process of claim 6, further comprising the step of stripping the underlayer film in alkaline water after the ion implantation step.

11. The pattern forming process of claim 6, further comprising the step of stripping the underlayer film in alkaline water at pH 9 or higher after the ion implantation step.

12. The pattern forming process of claim 9 wherein the alkaline water contains 1 to 99% by weight of at least one member selected from the group consisting of ammonia, ammonia hydrogen peroxide water, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, choline hydroxide, benzyltrimethylammonium hydroxide, benzyltriethylammonium hydroxide, DBU, DBN, hydroxylamine, 1-butyl-1-methylpyrrolidinium hydroxide, 1-propyl-1-methylpyrrolidinium hydroxide, 1-butyl-1-methylpiperidinium hydroxide, 1-propyl-1-methylpiperidinium hydroxide, mepiquathydroxide, trimethylsulfonium hydroxide, hydrazines, ethylenediamines, and guanidines.