Semiconductor device and method of manufacturing the same

Abstract

A barrier metal film such as a TiN film is formed in a contact hole or a via hole. Then, a W nucleation film is formed on the barrier metal film by CVD that reduces WF6 gas with B2H6 gas. Subsequently, a W plug is formed as a contact plug or a via plug on the W nucleation film by CVD.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 to 5 illustrate sectional views of a process of a method of manufacturing a semiconductor device according to a first preferred embodiment of this invention;

FIG. 6 illustrates a sectional view of the semiconductor device according to the first preferred embodiment;

FIG. 7 illustrates a semiconductor device manufactured by a conventional method of manufacturing a semiconductor device;

FIG. 8 illustrates the semiconductor device manufactured by the method of manufacturing a semiconductor device according to the first preferred embodiment;

FIG. 9 is a graph demonstrating the effect of the semiconductor device and the method of manufacturing the same according to the first preferred embodiment;

FIG. 10 is a graph demonstrating the relationship between a barrier metal film thickness and resistivity of the semiconductor device according to the first preferred embodiment;

FIGS. 11 to 15 illustrate sectional views of a process of a method of manufacturing a semiconductor device according to a second preferred embodiment of this invention;

FIG. 16 illustrates a sectional view of the semiconductor device according to the second preferred embodiment;

FIG. 17 illustrates another sectional view of the semiconductor device according to the second preferred embodiment; and

FIG. 18 is a graph demonstrating the effect of the semiconductor device and the method of manufacturing the same according to the second preferred embodiment.

Claims

1. A method of manufacturing a semiconductor device, comprising the steps of: (a) forming a MISFET (Metal Insulator Semiconductor Field Effect Transistor) on a surface of a semiconductor substrate, said MISFET including a source and drain region, a gate insulating film, and a gate electrode;(b) forming an insulating film to cover said surface of said semiconductor substrate and said MISFET;(c) forming a contact hole in said insulating film such that at least part of said source and drain region and at least part of a side surface of said gate electrode are exposed in said contact hole;(d) forming a barrier metal film in said contact hole;(e) forming a W (tungsten) nucleation film on said barrier metal film by CVD (Chemical Vapor Deposition) that reduces WF6 (tungsten hexafluoride) gas with B2H6 (diborane) gas; and(f) forming a W (tungsten) plug on said W nucleation film by CVD with WF6 gas, to bury said W plug in said contact hole.

2. The method of manufacturing a semiconductor device according to claim 1, wherein said barrier metal film is formed from one of a TiN (titanium nitride) film, a WN (tungsten nitride) film, a laminated film of a TiN film and a Ti (titanium) film, and a laminated film of a WN film and a W (tungsten) film, andsaid TiN film and said WN film are formed by MOCVD (Metal Organic Chemical Vapor Deposition).

3. The method of manufacturing a semiconductor device according to claim 1, wherein said W nucleation film is formed by ALD (Atomic Layer Deposition).

4. The method of manufacturing a semiconductor device according to claim 1, wherein said W plug is also formed by CVD that reduces WF6 gas with B2H6 gas.

5. A method of manufacturing a semiconductor device, comprising the steps of: (a) forming a wiring layer above a semiconductor substrate;(b) forming a barrier film on said wiring layer;(c) forming an insulating film to cover said wiring layer and said barrier film;(d) forming a via hole in said insulating film such that at least part of said barrier film is exposed in said via hole, said via hole being formed such that at least part of a side surface of said wiring layer is also exposed in said via hole;(e) forming a barrier metal film in said via hole;(f) forming a W (tungsten) nucleation film on said barrier metal film by CVD (Chemical Vapor Deposition) that reduces WF6 (tungsten hexafluoride) gas with B2H6 (diborane) gas; and(g) forming a W (tungsten) plug on said W nucleation film by CVD with WF6 gas, to bury said W plug in said via hole.

6. The method of manufacturing a semiconductor device according to claim 5, wherein said barrier metal film is formed from one of a TiN (titanium nitride) film, a WN (tungsten nitride) film, a laminated film of a TiN film and a Ti (titanium) film, and a laminated film of a WN film and a W (tungsten) film, andsaid TiN film and said WN film are formed by MOCVD (Metal Organic Chemical Vapor Deposition).

7. The method of manufacturing a semiconductor device according to claim 5, wherein said W nucleation film is formed by ALD (Atomic Layer Deposition).

8. The method of manufacturing a semiconductor device according to claim 5, wherein said W plug is also formed by CVD that reduces WF6 gas with B2H6 gas.

9. A semiconductor device manufactured by the method of manufacturing a semiconductor device according to claim 1.

10. A semiconductor device manufactured by the method of manufacturing a semiconductor device according to claim 5.