Method of depositing tungsten layer with improved adhesion and filling behavior

Patent metadata

Field	Value
Publication number	US-9589809-B2
Application number	US-201514744835-A
Country	US
Kind code	B2
Filing date	Jun 19, 2015
Priority date	Jan 3, 2014
Publication date	Mar 7, 2017
Grant date	Mar 7, 2017

Abstract

A method of depositing a tungsten (W) layer is disclosed. In one aspect, the method includes depositing a SiH 4 base W film on a surface of a substrate to preprocess the surface. The method includes depositing a B 2 H 6 base W layer on the preprocessed surface. The SiH 4 base W film may be several atom layers thick. The film and base W layer may be deposited in a single ALD process, include reactive gas soak, reactive gas introduction, and main deposition operations. Forming the film may include introducing SiH 4 gas into a reactive cavity during the gas soak operation, and introducing SiH 4 and WF 6 gas into the cavity during the gas introduction operation. The SiH 4 and WF 6 gases may be alternately introduced, for a number of cycles depending on the thickness of the tungsten layer to be deposited.

First claim

What is claimed is:

1. A method of depositing a tungsten (W) layer, comprising:
depositing a SiH 4 base W film on a surface of a substrate to preprocess the surface; and
depositing a B 2 H 6 base W layer on the preprocessed surface, wherein the substrate comprises a gate trench formed by a gate-last process, and wherein the W film and the W layer fill into the gate trench to function as a gate electrode.

2. The method of claim 1 , wherein the SiH 4 base W film is several atom layers thick.

3. The method of claim 1 , further comprising depositing the SiH 4 base W film and the B 2 H 6 base W layer in a single atomic layer deposition (ALD) process.

4. The method of claim 3 , wherein the single atomic layer deposition (ALD) process comprises:
a reactive source gas soak operation;
a reactive source gas introduction operation; and
a main deposition operation.

5. The method of claim 4 , wherein forming the SiH 4 base W film comprises:
introducing SiH 4 gas to a reactive cavity during the reactive source gas soak operation; and
introducing SiH 4 gas and WF 6 gas to the reactive cavity during the reactive source gas introduction operation.

6. The method of claim 5 , wherein the reactive source gas introduction operation comprises alternately introducing SiH 4 gas and WF 6 gas into the reactive cavity for several cycles.

7. The method of claim 6 , wherein the number of cycles is 2-10.

8. The method of claim 4 , wherein depositing the B 2 H 6 base W layer comprises:
alternately introducing B 2 H 6 gas and WF 6 gas into a reactive cavity for a number of cycles during the main deposition operation.

9. The method of claim 8 , wherein the number of the cycles depends on a thickness of the W layer to be deposited.

Assignees

• Inst Of Microelectronics Cas

Inventors

• Xu Qiang
• Zhao Chao
• Luo Jun
• Wang Guilei
• Yang Tao
• Li Junfeng

Classifications

• H10P14/412

  Deposition of metallic or metal-silicide materials · CPC title

• H10D64/01318

  the conductor comprising a layer of alloy material, compound material or organic material contacting the insulator, e.g. TiN (comprising a layer of alloys of Si, Ge or C H10D64/01314) · CPC title

• H10D64/01316

  the conductor comprising a layer of elemental metal contacting the insulator, e.g. Ta, W, Mo or Al · 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