SUBSTRATE PROCESSING METHOD AND SUBSTRATE PROCESSING APPARATUS

• US 20080003836A1
• Filed: 06/27/2007
• Published: 01/03/2008
• Est. Priority Date: 06/29/2006
• Status: Active Grant

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: YATSUDA, Koichi, NISHIMURA, Eiichi
• Granted Patent: US 8,114,781 B2
• Time in Patent Office: Days
• US Class Current: 438/710
• CPC Class Codes: H01L 21/31116 by dry-etching
• CPC Class Codes: H01L 21/67207 comprising a chamber adapted to a particular process

Abstract

A substrate processing method capable of selectively removing a nitride film. Oxygen plasma containing plasmarized oxygen gas is made to be in contact with a silicon nitride film, which is made of SiN, of a wafer to thereby cause the silicon nitride film to be changed to a silicon monoxide film. The silicon monoxide film is selectively etched by hydrofluoric acid generated from HF gas supplied toward the silicon monoxide film.

Claims

1. A substrate processing method for processing a substrate having a thermally-oxidized film formed by thermal oxidation processing and a nitride film, comprising:

an oxygen-containing plasma contact step of causing oxygen-containing plasma to be in contact with the substrate; and

an HF gas supply step of supplying HF gas toward the substrate with which the oxygen-containing plasma has been in contact.

2. The substrate processing method according to claim 1, wherein the substrate has a protruding conductive portion thereof protruding from the thermally-oxidized film,

wherein the nitride film covers side surfaces and a top surface of the conductive portion, and

wherein in said oxygen-containing plasma contact step, active species in the oxygen-containing plasma move substantially parallel to the side surfaces of the conductive portion and are in contact with the nitride film.

3. The substrate processing method according to claim 2, wherein the active species include at least cations.

4. The substrate processing method according to claim 2, further including:

a selective oxidation step of selectively oxidizing a flat portion of the nitride film.

5. The substrate processing method according to claim 1, wherein the substrate comprises a protruding conductive portion on the thermally-oxidized film, the protruding conductive portion perpendicularly protruding from a surface of the substrate,

wherein the nitride film covers side surfaces and a top surface of the conductive portion, and

wherein in said oxygen-containing plasma contact step, active species in the oxygen-containing plasma move in a direction approximately perpendicular to the surface of the substrate, whereby the active species are in contact with the nitride film.

6. The substrate processing method according to claim 5, further including:

a selective oxidation step of selectively oxidizing a flat portion of the nitride film.

7. A substrate processing apparatus for processing a substrate having a thermally-oxidized film formed by thermal oxidation processing and a nitride film, comprising:

an oxygen-plasma contact unit adapted to cause oxygen-containing plasma to be in contact with the substrate; and

an HF gas supply unit adapted to supply HF gas toward the substrate with which the oxygen-containing plasma has been in contact.