Boron doped tungsten carbide for hardmask applications

Patent metadata

Field	Value
Publication number	US-2018218902-A1
Application number	US-201815882204-A
Country	US
Kind code	A1
Filing date	Jan 29, 2018
Priority date	Feb 1, 2017
Publication date	Aug 2, 2018
Grant date	—

Abstract

Implementations of the present disclosure generally relate to the fabrication of integrated circuits. More particularly, the implementations described herein provide techniques for deposition of hardmask films on a substrate. In one implementation, a method of forming a hardmask layer on a substrate is provided. The method comprises forming a seed layer on a substrate by supplying a seed layer gas mixture in a processing chamber. The method further includes forming a transition layer comprising tungsten, boron and carbon on the seed layer by supplying a transition layer gas mixture in the processing chamber. The method further includes forming a bulk hardmask layer comprising tungsten, boron and carbon on the transition layer by supplying a main deposition gas mixture in the processing chamber.

First claim

1 . A method of forming a hardmask layer on a substrate comprising:
forming a seed layer on a substrate by supplying a seed layer gas mixture in a processing chamber; forming a transition layer comprising tungsten, boron and carbon on the seed layer by supplying a transition layer gas mixture in the processing chamber; and forming a bulk hardmask layer comprising tungsten, boron and carbon on the transition layer by supplying a main deposition gas mixture in the processing chamber.

2 . The method of claim 1 , wherein the transition layer gas mixture comprises at least a boron-based precursor gas, a carbon-based precursor gas and a tungsten-based precursor gas.

3 . The method of claim 2 , wherein the main deposition gas mixture comprises the boron-based precursor gas, the carbon-based precursor gas and the tungsten-based precursor gas.

4 . The method of claim 3 , wherein the seed layer gas mixture comprises at least the boron-based precursor gas and the carbon-based precursor gas.

5 . The method of claim 3 , wherein the boron-based precursor gas is B 2 H 6 , the carbon-based precursor gas is C 3 H 6 , and the tungsten-based precursor gas is WF 6 .

6 . The method of claim 2 , wherein the transition layer gas mixture is supplied to the processing chamber by reducing a gas flow rate of the carbon-based precursor gas while maintaining a steady gas flow rate of the boron-based precursor gas.

7 . The method of claim 6 , wherein the transition layer gas mixture is supplied to the processing chamber by ramping up a gas flow rate of the tungsten-based precursor.

8 . The method of claim 7 , wherein the main deposition gas mixture is supplied to the processing chamber by steadily supplying the boron-based precursor gas, the carbon-based precursor gas, and the tungsten-based precursor gas.

9 . The method of claim 8 , further comprising supplying a hydrogen-based precursor gas into the processing chamber while forming the seed layer, forming the transition layer, and forming the bulk hardmask layer.

10 . The method of claim 9 , wherein supplying the hydrogen-based precursor gas into the processing chamber comprises steadily supplying the hydrogen-based precursor gas into the processing chamber.

11 . The method of claim 1 , further comprising:
ramping a high frequency RF power while forming the seed layer and forming the transition layer; and steadily supplying the high frequency RF power while forming the bulk hardmask layer.

12 . The method of claim 1 , further comprising supplying a low frequency RF power while forming the transition layer and forming the bulk hardmask layer.

13 . The method of claim 12 , further comprising applying a bias to the substrate while supplying the low frequency RF power.

14 . The method of claim 1 , wherein the seed layer is selected from a boron carbide (BC) seed layer, a boron nitride (BN) seed layer, a boron carbon nitride (BCN) seed layer, a carbon nitride (CN) seed layer, a silicon carbide (SiC) seed layer, a silicon nitride (SiN) seed layer, a boron-based seed layers, a carbon seed layer, a titanium nitride (TiN) seed layer, or a tungsten silicide (WSi) seed layer.

15 . A method of forming a hardmask layer comprising:
supplying a gas mixture including at least a boron-based precursor gas and a carbon-based precursor gas onto a surface of a substrate disposed in a processing chamber to form a seed layer on the substrate; ramping down the carbon-based precursor gas and ramping up a tungsten-based precursor gas supplied in the gas mixture while maintaining a steady flow of the boron-based precursor gas into the processing chamber to form a transition layer on the seed layer; and continuously supplying the tungsten-based precursor gas in the gas mixture until the tungsten-based precursor gas reaches to a predetermined flow rate and maintaining the tungsten-based precursor gas at a steady predetermined flow rate to form a bulk hardmask layer.

16 . The method of claim 15 , wherein the seed layer is a boron carbide layer, the transition layer is a tungsten boron carbide layer, and the bulk hardmask layer is a tungsten boron carbide layer.

17 . A hardmask layer, comprising:
a hardmask layer comprising a seed layer, a transition layer and a bulk hardmask layer disposed on the transition layer.

18 . The hardmask layer of claim 17 , wherein the seed layer is a boron carbide layer, the transition layer is a tungsten boron carbide layer and the bulk hardmask layer is a tungsten boron carbide layer.

19 . The hardmask layer of claim 18 , wherein the hardmask layer comprises from about 50 to about 70 atomic percentage of tungsten, from about 10 to about 30 atomic percentage of carbon, and from about 10 to about 20 atomic percentage of boron.

20 . The hardmask layer of claim 18 , wherein the hardmask layer has a gradient film structure.

Assignees

• Applied Materials Inc

Inventors

• Venkatasubramanian Eswaranand
• Mallick Abhijit Basu
• Roy Susmit Singha
• Koshizawa Takehito

Classifications

• H10P50/285

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

• H10P50/283

  by chemical means · CPC title

• H10P50/73

  using masks for insulating materials · CPC title

• H10P14/6939

  characterised by the metal · CPC title

• H10P14/6506

  Formation of intermediate materials · CPC title