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

Patent metadata

Field	Value
Publication number	US-2016005602-A1
Application number	US-201414324000-A
Country	US
Kind code	A1
Filing date	Jul 3, 2014
Priority date	Jul 3, 2014
Publication date	Jan 7, 2016
Grant date	—

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

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 comprising 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, oxygen, hydrogen, and carbon 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