Two-stage etching process

• US 20030173333A1
• Filed: 02/03/2003
• Published: 09/18/2003
• Est. Priority Date: 03/27/2000
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Wang, Xikun, Williams, Scott, Pan, Shaoher X.
• Granted Patent: US 6,787,054 B2
• Time in Patent Office: Days
• US Class Current: 216/67
• CPC Class Codes: H01J 37/321 the radio frequency energy being inductively coupled to the plasma
• CPC Class Codes: H01L 21/3065 Plasma etching; Reactive-ion etching
• CPC Class Codes: H01L 21/3081 characterised by their composition, e.g. multilayer masks, materials
• CPC Class Codes: H01L 21/31116 by dry-etching
• CPC Class Codes: H01L 21/32137 of silicon-containing layers
• CPC Class Codes: Y10S 134/902 Semiconductor wafer
• CPC Class Codes: Y10S 438/905 Cleaning of reaction chamber
• CPC Class Codes: Y10S 438/906 Cleaning of wafer as interim step

Abstract

A process for etching a substrate and removing etch residue deposited on the surfaces in the etching chamber has two stages. In the first stage, an energized first process gas is provided in the chamber, and in the second stage, an energized second process gas is provided in the chamber. The energized first process gas comprises SF₆ and Ar, the volumetric flow ratio of SF₆ to other components of the first process gas being from about 5:1 to about 1:10. The energized second process gas comprises CF₄ and Ar, the volumetric flow ratio of CF₄ to other components of the second process gas being from about 1:0 to about 1:10.

Claims

1. A substrate etching method comprising:

placing a substrate in the chamber;

in a first stage, providing in the chamber, an energized first process gas comprising SF₆ and Ar, the volumetric flow ratio of SF₆ to other components of the first process gas being from about 5;

1 to about 1;

10; and

in a second stage, providing in the chamber, an energized second process gas comprising CF₄ and Ar, the volumetric flow ratio of CF₄ to other components of the second process gas being from about 1;

0 to about 1;

10.

2. A method according to claim 1 wherein at least one of the first and second process gases comprise HBr.

3. A method according to claim 1 wherein substrate comprises a first silicon-containing layer overlying a second silicon-containing layer, and wherein the first process gas comprises a composition to etch the first silicon-containing layer and the second process gas comprises a composition to etch the second silicon-containing layer.

4. A method according to claim 3 wherein the first silicon-containing layer comprises silicon nitride or metal silicide.