Manufacturing method of semiconductor device and semiconductor device

Abstract

In a manufacturing process of a semiconductor device having a CMISFET, first, a silicon film and a first metal film made of a first metal are reacted with each other through heat treatment, thereby forming a gate electrode of a p-channel type MISFET and a dummy gate electrode of an n-channel type MISFET, which are formed of metal silicide. Subsequently, an insulating film is formed so as to cover the gate electrode but expose the dummy electrode, and then, a metal film formed of a second metal having a work function lower than that of the first metal. The metal film contacts with the dummy gate but not with the gate electrode due to the insulating film interposing therebetween. Thereafter, through heat treatment, the dummy gate electrode and the metal film are reacted with each other to form a gate electrode of the n-channel type MISFET.

Description

BRIEF DESCRIPTIONS OF THE DRAWINGS

FIG. 1 is a cross-sectional view showing main parts of a semiconductor device in a manufacturing process according to one embodiment of the present invention;

FIG. 2 is a cross-sectional view showing main parts of the semiconductor device in a manufacturing process continued from FIG. 1;

FIG. 3 is a cross-sectional view showing main parts of the semiconductor device in a manufacturing process continued from FIG. 2;

FIG. 4 is a cross-sectional view showing main parts of the semiconductor device in a manufacturing process continued from FIG. 3;

FIG. 5 is a cross-sectional view showing main parts of the semiconductor device in a manufacturing process continued from FIG. 4;

FIG. 6 is a cross-sectional view showing main parts of the semiconductor device in a manufacturing process continued from FIG. 5;

FIG. 7 is a cross-sectional view showing main parts of the semiconductor device in a manufacturing process continued from FIG. 6;

FIG. 8 is a cross-sectional view showing main parts of the semiconductor device in a manufacturing process continued from FIG. 7;

FIG. 9 is a cross-sectional view showing main parts of the semiconductor device in a manufacturing process continued from FIG. 8;

FIG. 10 is a cross-sectional view showing main parts of the semiconductor device in a manufacturing process continued from FIG. 9;

FIG. 11 is a cross-sectional view showing main parts of the semiconductor device in a manufacturing process continued from FIG. 10;

FIG. 12 is a cross-sectional view showing main parts of the semiconductor device in a manufacturing process continued from FIG. 11;

FIG. 13 is a cross-sectional view showing main parts of the semiconductor device in a manufacturing process continued from FIG. 12;

FIG. 14 is a graph showing C-V characteristics of MOS capacitors;

FIG. 15 is a cross-sectional view showing main parts of a semiconductor device in a manufacturing process according to another embodiment of the present invention;

FIG. 16 is a cross-sectional view showing main parts of the semiconductor device in a manufacturing process continued from FIG. 15;

FIG. 17 is a cross-sectional view showing main parts of the semiconductor device in a manufacturing process continued from FIG. 16; and

FIG. 18 is a cross-sectional view showing main parts of the semiconductor device in a manufacturing process continued from FIG. 17.

Claims

1. A manufacturing method of a semiconductor device including a first MISFET of p-channel type and a second MISFET of n-channel type, comprising the steps of: (a) preparing a semiconductor substrate;(b) forming a first gate electrode of the first MISFET and a dummy gate electrode of the second MISFET, which are formed of a metal silicide containing a first metal as its constituent element, on the semiconductor substrate;(c) forming a metal film formed of a second metal having a work function lower than that of the first metal so that the metal film contacts with the dummy gate electrode but not with the first gate electrode; and(d) performing a heat treatment to react the dummy gate electrode with the metal film, thereby forming a second gate electrode formed of a conductive film containing Si, the first metal, and the second metal as its constituent elements.

2. The manufacturing method of a semiconductor device according to claim 1, wherein, in the step (d), the first gate electrode is not reacted with the metal film.

3. The manufacturing method of a semiconductor device according to claim 1, wherein the heat treatment of the step (d) is a heat treatment performed at 600° C. or lower.

4. The manufacturing method of a semiconductor device according to claim 1, wherein the step (b) comprises the steps of:(b1) forming a gate insulator on the semiconductor substrate;(b2) forming a first dummy electrode of the first MISFET made of silicon and a second dummy electrode of the second MISFET made of silicon on the gate insulator;(b3) forming a first metal film formed of the first metal on the first dummy electrode and the second dummy electrode; and(b4) performing a heat treatment to react the first dummy electrode with the first metal film, thereby forming the first gate electrode, and react the second dummy electrode with the first metal film, thereby forming the dummy gate electrode.

5. The manufacturing method of a semiconductor device according to claim 4, wherein the heat treatment of the step (d) and the heat treatment of the step (b4) are a heat treatment performed at 300° C. or higher, respectively.

6. The manufacturing method of a semiconductor device according to claim 1, wherein the first metal is at least one of those selected from a group of: Ni, Pt, Ru, Ir, Pd, and Co.

7. The manufacturing method of a semiconductor device according to claim 1, wherein the first metal is Ni.

8. The manufacturing method of a semiconductor device according to claim 1, wherein the second metal is at least one of those selected from a group of: Al, Hf, Ti, Zr, and Ta.

9. The manufacturing method of a semiconductor device according to claim 1, wherein the second metal is Al.

10. The manufacturing method of a semiconductor device according to claim 1, wherein the step (c) comprises the steps of:(c1) forming a first material film to cover the first gate electrode and expose the dummy gate electrode; and(c2) after the step (c1), forming the metal film on the first gate electrode and the dummy gate electrode, andthe metal film formed in the step (c2) contacts with the dummy gate electrode but not with the first gate electrode due to the first material film interposed therebetween.

11. The manufacturing method of a semiconductor device according to claim 10, wherein, in the step (c1), after the first material film is formed on the semiconductor substrate so as to cover the first gate electrode and the dummy gate electrode,the first material film is patterned, thereby forming the first material film which covers the first gate electrode and exposes the dummy gate electrode.

12. The manufacturing method of a semiconductor device according to claim 11, wherein, in the heat treatment of the step (d), the first material film is not reacted with the first gate electrode and the metal film.

13. The manufacturing method of a semiconductor device according to claim 1, wherein, in the step (c), after the metal film is formed on the semiconductor substrate so as to cover the first gate electrode and the dummy gate electrode, the metal film is patterned to remove the metal film on the first gate electrode and leave the metal film on the dummy gate electrode, thereby forming the metal film which contacts with the dummy gate electrode but not with the first gate electrode.

14. A manufacturing method of a semiconductor device having a first MISFET of p-channel type and a second MISFET of n-channel type, comprising the steps of: (a) preparing a semiconductor substrate;(b) forming a gate insulator on the semiconductor substrate;(c) forming a first dummy electrode formed of silicon for the first MISFET and a second dummy electrode formed of silicon for the second MISFET on the gate insulator;(d) forming a first metal film formed of a first metal on the first dummy electrode and the second dummy electrode;(e) performing a heat treatment to react the first dummy gate electrode with the first metal film, thereby forming a first gate electrode of the first MISFET made of metal silicide containing the first metal as its constituent element, and react the second dummy electrode with the first metal film, thereby forming a dummy gate electrode of the second MISFET made of metal silicide containing the first metal as its constituent element;(f) forming a second metal film formed of a second metal having a work function lower than that of the first metal so as to contact with the dummy gate electrode but not with the first gate electrode; and(g) performing a thermal treatment to react the dummy gate electrode with the second metal film, thereby forming a second gate electrode of the second MISFET.

15. The manufacturing method of a semiconductor device according to claim 14, wherein the second metal is Al.

16. The manufacturing method of a semiconductor device according to claim 14, wherein the step (f) comprises the steps of:(f1) forming a first material film so as to cover the first gate electrode and expose the dummy gate electrode; and(f2) after the step (f2), forming the second metal film on the first gate electrode and the dummy gate electrode, andthe second metal film formed in the step (f2) contacts with the dummy gate electrode but not with the first gate electrode due to the first material film interposed therebetween.

17. The manufacturing method of a semiconductor device according to claim 14, wherein, in the step (f), after the second metal film is formed on the semiconductor substrate so as to cover the first gate electrode and the dummy gate electrode, the second metal film is patterned to remove the second metal film on the first gate electrode and leave the second metal film on the dummy gate electrode, thereby forming the second metal film which contacts with the dummy gate electrode but not with the first gate electrode.

18. A semiconductor device comprising: a first MISFET of p-channel type; anda second MISFET of n-channel type,wherein a first gate electrode of the first MISFET is formed of a metal silicide film containing Si and a first metal as its constituent elements, anda second gate electrode of the second MISFET is formed of a conductive film containing Si, the first metal, and a second metal having a work function lower than that of the first metal.

19. The semiconductor device according to claim 18, wherein the first metal is Ni, andthe second metal is Al.

20. The semiconductor device according to claim 19, wherein the first gate electrode is made of nickel silicide, andthe second gate electrode is formed of the conductive film made of nickel silicide to which Al is introduced.