Methods of removing residual polymers formed during a boron-doped amorphous carbon layer etch process

Patent metadata

Field	Value
Publication number	US-9390923-B2
Application number	US-201414324000-A
Country	US
Kind code	B2
Filing date	Jul 3, 2014
Priority date	Jul 3, 2014
Publication date	Jul 12, 2016
Grant date	Jul 12, 2016

Abstract

Methods for removing residual polymers formed during etching of a boron-doped amorphous carbon layer are provided herein. In some embodiments, a method of etching a feature in a substrate includes: exposing a boron doped amorphous carbon layer disposed on the substrate to a first plasma through a patterned mask layer to etch a feature into the boron doped amorphous carbon layer, wherein the first plasma is formed from a first process gas that reacts with the boron doped amorphous carbon layer to form residual polymers proximate a bottom of the feature; and exposing the residual polymers to a second plasma through the patterned mask layer to etch the residual polymers proximate the bottom of the feature, wherein the second plasma is formed from a second process gas comprising nitrogen (N 2 ), oxygen (O 2 ), hydrogen (H 2 ), and methane (CH 4 ).

First claim

The invention claimed is:

1. A method of etching a feature in a substrate, comprising:
exposing a boron doped amorphous carbon layer disposed on the substrate to a first plasma through a patterned mask layer to etch a feature into the boron doped amorphous carbon layer, wherein the first plasma is formed from a first process gas that reacts with the boron doped amorphous carbon layer to form residual polymers proximate a bottom of the feature; and
exposing the residual polymers to a second plasma through the patterned mask layer to etch the residual polymers proximate the bottom of the feature, wherein the second plasma is formed from a second process gas consisting of nitrogen (N 2 ), oxygen (O 2 ), hydrogen (H 2 ), and methane (CH 4 ).

2. The method of claim 1 , wherein the first process gas comprises one of a fluorine-containing gas or a chlorine-containing gas.

3. The method of claim 1 , wherein the second plasma forms hydroxylamine (NH 2 OH) to react with the residual polymers proximate the bottom of the feature.

4. The method of claim 1 , further comprising forming the first plasma by igniting the first process gas using an RF power source.

5. The method of claim 4 , wherein the RF power source provides power at about 100 to about 5,000 watts.

6. The method of claim 1 , wherein the residual polymers comprise a fluorocarbon compound having a formula CF x .

7. The method of claim 1 , further comprising forming the second plasma by igniting the second process gas using an RF power source.

8. The method of claim 7 , wherein the RF power source provides power at about 100 to about 5,000 watts.

9. The method of claim 1 , further comprising applying a first bias power to the substrate while exposing the substrate to the first plasma.

10. The method of claim 9 , wherein the first bias power is about 15 to about 3,000 watts.

11. The method of claim 1 , further comprising applying a second bias power to substrate while exposing the substrate to the second plasma.

12. The method of claim 11 , wherein the second bias power is about 15 to about 3,000 watts.

13. The method of claim 1 , wherein the feature has an aspect ratio of depth to width of greater than about 10:1.

14. A method of processing a substrate, comprising:
depositing a boron doped amorphous carbon layer disposed atop a substrate;
depositing a patterned photoresist layer atop the boron doped amorphous carbon layer;
exposing the boron doped amorphous carbon layer to a first plasma formed from a first process gas comprising one of a fluorine containing gas or a chlorine containing gas to etch a feature into the boron doped amorphous carbon layer, wherein the first process gas reacts with the boron doped amorphous carbon layer to form residual polymers proximate a bottom of the feature; and
exposing the substrate to a second plasma formed from a second process gas comprising nitrogen (N2), oxygen (O2), hydrogen (H2), and methane (CH4) to etch the residual polymers proximate the bottom of the feature without etching the boron doped amorphous carbon layer.

15. The method of claim 14 , further comprising applying a first bias power to the substrate while exposing the substrate to the first plasma; and applying a second bias power to the substrate while exposing the substrate to the second plasma.

16. The method of claim 14 , further comprising forming the first plasma by igniting the first process gas using an RF power source at about 100 to about 5,000 watts.

17. The method of claim 14 , further comprising forming the second plasma by igniting the second process gas using an RF power source at about 100 to about 5,000 watts.

18. A method of etching a feature in a substrate, comprising:
exposing a boron doped amorphous carbon layer disposed on the substrate to a first plasma through a patterned mask layer to etch a feature into the boron doped amorphous carbon layer, wherein the first plasma is formed from a first process gas that reacts with the boron doped amorphous carbon layer to form residual polymers proximate a bottom of the feature; and
exposing the residual polymers through the patterned mask layer to hydroxylamine (NH 2 OH) formed by a second plasma to etch the residual polymers proximate the bottom of the feature.

19. The method of claim 18 , wherein the second plasma is formed from a second process gas consisting of nitrogen (N 2 ), oxygen (O 2 ), hydrogen (H 2 ), and methane (CH 4 ) and, optionally, an inert gas.

20. The method of claim 19 , wherein the second process gas includes the inert gas.

Assignees

• Applied Materials Inc

Inventors

• Yoo Jeong Hyun
• Lee Hoon Sang
• Kong Byungkook

Classifications

• H10P70/23 Primary

  during, before or after processing of insulating materials · CPC title

• H10P50/285

  of materials not containing Si, e.g. PZT or Al2O3 · CPC title

• H10P50/242

  of Group IV materials · CPC title

• H10P50/73

  using masks for insulating materials · CPC title

• H10P14/61

  using masks · CPC title