Residue free oxide etch

Patent metadata

Field	Value
Publication number	US-9595452-B2
Application number	US-201514723348-A
Country	US
Kind code	B2
Filing date	May 27, 2015
Priority date	May 27, 2015
Publication date	Mar 14, 2017
Grant date	Mar 14, 2017

Abstract

A method for selectively etching silicon oxide is provided. A surface reaction phase is provided comprising flowing a surface reaction gas comprising hydrogen, nitrogen and fluorine containing components to form silicon oxide into a compound comprising silicon, hydrogen, nitrogen, and fluorine, forming the surface reaction gas into a plasma, and stopping the flow of the surface reaction gas. The surface is wet treated to remove the compound.

First claim

What is claimed is:

1. A method for selectively etching silicon oxide, comprising:
providing a surface reaction phase, comprising:
flowing a surface reaction gas comprising hydrogen, nitrogen and fluorine containing components;
forming the surface reaction gas into a plasma to form silicon oxide into a compound layer comprising silicon, hydrogen, nitrogen, and fluorine;
heating the plasma by,
flowing a heating gas, wherein the heating gas comprises H 2 or N 2 or NH 3 , and wherein the heating gas is NF 3 and HF free;
forming the heating gas into a plasma; and
stopping the flow of the heating gas;

stopping the flow of the surface reaction gas; and
wet treating the surface to remove the compound layer;
wherein the surface reaction gas comprises: NF 3 or HF; and H 2 or N 2 or NH 3 ; and the compound is an amine containing salt.

2. The method, as recited in claim 1 , wherein the surface reaction gas comprises NF 3 and NH 3 and wherein the heating gas comprises NH 3 and is free of NF 3 .

3. The method, as recited in claim 2 , wherein the providing the surface reaction phase and providing the plasma heating phase make up a dry treatment, wherein the dry treatment is repeated cyclically a plurality of times.

4. The method, as recited in claim 3 , wherein the dry treatment is performed at a pressure of at least 5 mTorr.

5. The method, as recited in claim 4 , wherein the surface reaction gas and the heating gas both further comprise flowing a noble gas.

6. The method, as recited in claim 5 , wherein a continuous plasma is maintained during the cyclically repeated dry treatment.

7. The method, as recited in claim 1 , wherein providing the surface reaction and wet treating the surface are cyclically repeated a plurality of times.

8. The method, as recited in claim 7 , wherein the wet treating uses a hydrophobic solvent that is able to dissolve the compound layer without oxidizing silicon.

9. The method, as recited in claim 1 , wherein the wet treating uses a solvent that is able to dissolve the compound layer without oxidizing silicon.

Assignees

• Lam Res Corp

Inventors

• Hsu Chih-Hsun
• Shen Meihua
• Lill Thorsten

Classifications

• H10P70/23 Primary

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

• H10P50/283

  by chemical means · CPC title

• H10P95/70

  Chemical treatments · CPC title

• H10P52/00

  Grinding, lapping or polishing of wafers, substrates or parts of devices · CPC title

• H10P50/20 Primary

  Dry etching; Plasma etching; Reactive-ion etching · CPC title