PLASMA ETCHING METHOD AND PLASMA ETCHING APPARATUS

• US 20140134848A1
• Filed: 11/07/2013
• Published: 05/15/2014
• Est. Priority Date: 11/09/2012
• Status: Active Grant

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: HONDA, Masanobu, HISAMATSU, Toru, KIHARA, Yoshihide
• Granted Patent: US 9,330,935 B2
• Time in Patent Office: Days
• US Class Current: 438/725
• CPC Class Codes: H01J 2237/334 Etching
• CPC Class Codes: H01L 21/0273 characterised by the treatment of photoresist layers
• CPC Class Codes: H01L 21/31138 by dry-etching
• CPC Class Codes: H01L 21/31144 using masks

Abstract

Disclosed is a plasma etching method which suppresses the narrowing of the line-width of the line formed by etching and maintain the height of a remaining photoresist. The plasma etching method includes a modification process and an etching process. The modification process modifies a photoresist having a predetermined pattern by plasma of HBr/Ar gas while applying a negative DC voltage to an upper electrode containing silicon disposed to face a target object in which an organic film and the photoresist are sequentially laminated. The etching process etches the organic film by plasma of a processing gas which contains a CF-based gas and a CHF-based gas.

Claims

1. A plasma etching method comprising:

modifying a photoresist having a predetermined pattern by plasma of HBr/Ar gas while applying a negative DC voltage to an upper electrode containing silicon disposed to face a target object in which an organic film and the photoresist are sequentially laminated; and

using the photoresist modified at the modifying, etching the organic film by plasma of a processing gas which contains a CF-based gas and a CHF-based gas.

2. The plasma etching method according to claim 1, wherein the photoresist is an ArF resist formed by using an ArF excimer laser.

3. The plasma etching method according to claim 1, wherein the photoresist is an Extreme Ultra-Violet (EUV) resist formed by using EUV light.

4. The plasma etching method according to claim 1, wherein the CF-based gas is a CF4 gas and the CHF-based gas is a CHF3 gas.

5. The plasma etching method according to claim 1, wherein the organic film is a Si-ARC film.

6. A plasma etching apparatus comprising:

a processing chamber configured to perform a plasma etching process on a target object in which an organic film and a photoresist having a predetermined pattern are sequentially laminated;

a depressurizing unit configured to reduce an internal pressure of the processing chamber;

a gas supply unit configured to supply a processing gas into the processing chamber;

an upper electrode containing silicon disposed to face the target object; and

a control unit configured to execute a modification process which modifies the photoresist by plasma of HBr/Ar gas while applying a negative DC voltage to the upper electrode containing silicon, and an etching process which etches the organic film by the plasma of the processing gas which contains a CF-based gas and a CHF-based gas using the modified photoresist as a mask.