Method of dry etching, dry etching gas and process for producing perfluoro-2-pentyne

• US 20050247670A1
• Filed: 07/16/2003
• Published: 11/10/2005
• Est. Priority Date: 07/17/2002
• Status: Abandoned Application

• Current Assignee: ZEON Corporation
• Original Assignee: ZEON Corporation
• Inventors: Sugimoto, Tatsuya, Yamada, Toshiro
• Application Number:
  US10/520,272
• Publication Number:
  US 20050247670A1
• Time in Patent Office: Days
• US Class Current: 216/67
• CPC Class Codes: C07C 17/25 by splitting-off hydrogen halides from halogenated hydrocarbons
• CPC Class Codes: C07C 17/2637 between a compound containing only oxygen and possibly halogen as hetero-atoms and a halogenated hydrocarbon
• CPC Class Codes: C07C 21/18 containing fluorine
• CPC Class Codes: C07C 21/22 containing carbon-to-carbon triple bonds
• CPC Class Codes: H01L 21/31116 by dry-etching
• CPC Class Codes: H01L 21/32136 using plasmas

Abstract

A dry etching method wherein a resist film is irradiated with radiation having a wavelength of not more than 195 nm to form a resist pattern having a minimum line width of not more than 200 nm, and the substrate having the resist pattern formed thereon is subjected to dry etching using a fluorine-containing compound having 4 to 6 carbon atoms and at least one unsaturated bond as an etching gas. As the fluorine-containing compound, perfuloro-2-pentyne, perfuloro-2-butyne, nonafluoro-2-pentene and perfluoro-2-pentene are preferably used. Perfuloro-2-pentyne is produced by a process wherein a 1,1,1-trihalo-2,2,2-trifluoroethane is allowed to react with pentafluoropropionaldehyde to give a 2-halo-1,1,1,4,4,5,5,5-octafluoro-2-pentene, and the thus-produced halo-octafluoro-2-pentene is dehydrohalogenated.

Claims

1. A dry etching method characterized in that a resist film formed on a substrate is irradiated with radiation having a wavelength of not more than 195 nm to form a resist pattern having a minimum line width of not more than 200 nm, and the substrate having the resist pattern formed thereon is subjected to dry etching using a fluorine-containing compound having 4 to 6 carbon atoms and at least one unsaturated bond as an etching gas.

2. The dry etching method according to claim 1, wherein the resist film is formed from a high molecular weight compound containing 0% to 10% by weight of repeating units having an aromatic ring structure.

3. The dry etching method according to claim 1, wherein the fluorine-containing compound having 4 to 6 carbon atoms and at least one unsaturated bond is selected from perfuloro-2-butyne and perfuloro-2-pentyne.

4. The dry etching method according to claim 1, wherein the fluorine-containing compound having 4 to 6 carbon atoms is perfuloro-2-pentyne.

5. The dry etching method according to claim 1, wherein the fluorine-containing compound having 4 to 6 carbon atoms and at least one unsaturated bond is at least one kind of flouropentene selected from 1,1,1,2,4,4,5,5,5-nonafluoro-2-pentene, 1,1,1,3,4,4,5-nonafluoro-2-pentene and perfluoro-2-pentene.

6. The dry etching method according to claim 1, wherein the dry etching is carried out under irradiation with plasma having a plasma density of at least 10¹⁰ ions/cm³.

7. A dry etching gas comprised of a fluorine-containing compound having 4 to 6 carbon atoms and at least one unsaturated bond, and used for dry etching for a resist film forming a resist pattern having a minimum line width of not more than 200 nm at irradiation with radiation having a wavelength of not more than 195 nm.

8. The dry etching gas according to claim 7, wherein the fluorine-containing compound having 4 to 6 carbon atoms and at least one unsaturated bond is selected from perfuloro-2-butyne and perfuloro-2-pentyne.

9. The dry etching gas according to claim 7, wherein the fluorine-containing compound having 4 to 6 carbon atoms and at least one unsaturated bond is perfuloro-2-pentyne.

10. The dry etching gas according to claim 7, wherein the flourine-containing compound having 4 to 6 carbon atoms and at least one unsaturated bond is at least one kind of fluoropentene selected from 1,1,1,2,4,4,5,5,5-nonafluoro-2-pentene, 1,1,1,3,4,4,5-nonafluoro-2-pentene and perfluoro-2-pentene.

11. A process for producing perfluoro-2-pentyne characterized in that a 1,1,1-trihalo-2,2,2-trifluoroethane is allowed to react with pentafluoropropionaldehyde to give a 2-halo-1,1,1,4,4,5,5,5-octafluoro-2-pentene, and the thus-produced 2-halo-1,1,1,4,4,5,5,5-octafluoro-2-pentene is dehyrohalogenated.

12. The process for producing perfluoro-2-pentyne according to claim 11, wherein the 1,1,1-trihalo-2,2,2-trifluoroethane is 1,1,1-trichloro-2-2-2-trifluoroethane.