Method of reducing stress in metal film and metal film forming method

Patent metadata

Field	Value
Publication number	US-2016351402-A1
Application number	US-201615165524-A
Country	US
Kind code	A1
Filing date	May 26, 2016
Priority date	May 28, 2015
Publication date	Dec 1, 2016
Grant date	—

Abstract

There is provided a method of reducing stress in a metal film that is highly stressed, the method including: processing the metal film by supplying a metal chloride gas containing a metal of the metal film and a reduction gas for reducing the metal chloride gas onto the metal film; and forming a process film on the metal film to reduce stress in the metal film.

First claim

What is claimed is:

1 . A method of reducing stress in a metal film that is highly stressed, the method comprising:
processing the metal film by supplying a metal chloride gas containing a metal of the metal film and a reduction gas for reducing the metal chloride gas onto the metal film; and forming a process film on the metal film to reduce stress in the metal film.

2 . The method of claim 1 , wherein the processing the metal film is performed by loading a target substrate having the metal film formed thereon into a chamber maintained under a depressurized atmosphere; and sequentially or simultaneously supplying the metal chloride gas and the reduction gas into the chamber such that the process film is formed on the metal film.

3 . The method of claim 1 , wherein the processing the metal film includes etching the metal film by HCl generated from a reaction between the metal chloride gas and the reduction gas.

4 . The method of claim 1 , wherein the stress in the metal film is controlled by adjusting a process condition and a thickness of the process film in the processing the metal film.

5 . The method of claim 1 , wherein the metal film is a tungsten film, and the metal chloride gas used in the processing the metal film is a tungsten chloride gas.

6 . The method of claim 5 , wherein the processing the metal film is performed under a condition that a partial pressure of the tungsten chloride gas ranges from 0.5 to 10 Torr.

7 . The method of claim 5 , wherein the tungsten film as the metal film is formed by loading the target substrate into the chamber maintained under the depressurized atmosphere and sequentially supplying the tungsten chloride gas and the reduction gas into the chamber,
wherein a flow rate of the tungsten chloride gas when forming the metal film is lower than that of the tungsten chloride gas in the processing the metal film.

8 . The method of claim 7 , wherein a partial pressure of the tungsten chloride gas when forming the tungsten film as the metal film is 1 Torr or less.

9 . The method of claim 5 , wherein the tungsten film as the metal film is formed by loading the target substrate into the chamber maintained under the depressurized atmosphere and supplying a WF 6 gas and the reduction gas into the chamber.

10 . The method of claim 5 , wherein the tungsten chloride is one of WCl 6 , WCl 5 , and WCl 4 .

11 . The method of claim 1 , wherein the reduction gas is at least one of an H 2 gas, an SiH 4 gas, a B 2 H 6 gas and an NH 3 gas.

12 . The method of claim 1 , wherein the stress in the metal film is 1,000 Pa or more.

13 . A method of forming a metal film, comprising:
forming a metal film on a target substrate; processing the metal film by supplying a metal chloride gas containing a metal of the metal film and a reduction gas for reducing the metal chloride gas; and forming a process film on the metal film to reduce stress in the metal film.

14 . The method of claim 13 , wherein the process film is formed by loading the target substrate with the metal film formed thereon into a chamber maintained under a depressurized atmosphere and sequentially or simultaneously supplying the metal chloride gas and the reduction gas into the chamber.

15 . The method of claim 13 , wherein the forming a process film includes etching the metal film by HCl generated from a reaction between the metal chloride gas and the reduction gas.

16 . The method of claim 13 , wherein the stress in the metal film is controlled by adjusting a process condition and a thickness of the process film in the forming a process film.

17 . The method of claim 13 , wherein the stress in the metal film is 1,000 Pa or more.

18 . A method of forming a metal film, comprising:
forming a first tungsten film as the metal film by sequentially supplying a tungsten chloride gas and a reduction gas for reducing the tungsten chloride gas onto a target substrate; and forming a second tungsten film as a process film on the first tungsten film by sequentially or simultaneously supplying the tungsten chloride gas and the reduction gas for reducing the tungsten chloride gas onto the target substrate with the first tungsten film formed thereon so as to reduce stress in the first tungsten film, wherein a flow rate of the tungsten chloride gas in the forming a first tungsten film is lower than that of the tungsten chloride gas in the forming the second tungsten film.

19 . The method of claim 18 , wherein a partial pressure of the tungsten chloride gas in the forming a first tungsten film is 1 Torr or less, and a partial pressure of the tungsten chloride gas in the forming a second tungsten film ranges from 0.5 to 10 Torr.

20 . The method of claim 18 , wherein, in the forming a first tungsten film and le forming a second tungsten film, a temperature of the target substrate is 300 degrees C. or more and a pressure is 5 Torr or more.

21 . A method of forming a metal film, comprising:
forming a first tungsten film as the metal film by supplying a WF 6 gas and a reduction gas for reducing the WF 6 gas onto a target substrate; and forming a second tungsten film by sequentially or simultaneously supplying a tungsten chloride gas and a reduction gas for reducing the tungsten chloride gas onto the target substrate with the first tungsten film formed thereon.

22 . The method of claim 21 , wherein the stress in the first tungsten film is reduced by forming the second tungsten film.

23 . The method of claim 21 , wherein, in the forming a second tungsten film, a temperature of the target substrate is 300 degrees C. or more and a pressure is 5 Torr or more.

24 . The method of claim 18 , wherein the first tungsten film and le second tungsten film are formed in-situ.

25 . The method of claim 18 , wherein the tungsten chloride is one of WCl 6 , WCl 5 , and WCl 4 .

26 . The method of claim 18 , wherein the reduction gas is at least one of an H 2 gas, an SiH 4 gas, a B 2 H 6 gas and an NH 3 gas.

27 . The method of claim 18 , wherein the stress in the metal film is 1,000 Pa or more.

28 . A non-transitory storage medium storing a program that operates on a computer and controls a film forming apparatus,
wherein the program, when executed, causes the computer to control the film forming apparatus so as to perform the method of claim 18 .

Assignees

• Tokyo Electron Ltd

Inventors

• Suzuki Kenji
• Hotta Takanobu
• Maekawa Koji
• Aiba Yasushi

Classifications

• H10P95/00

  Generic processes or apparatus for manufacture or treatments not covered by the other groups of this subclass · CPC title

• H10P14/432 Primary

  using selective deposition · CPC title

• H10P14/412

  Deposition of metallic or metal-silicide materials · CPC title

• H10W20/056

  by filling conductive material into holes, grooves or trenches · CPC title

• H10W20/045

  for deposition from the gaseous phase, e.g. for chemical vapour deposition [CVD] · CPC title