Semiconductor device

1. A semiconductor device comprising an LDMOSFET including a source region, a drain region, and a gate electrode formed at a main surface of a semiconductor substrate comprising silicon, said device comprising:

said semiconductor substrate of a first conductivity type;

said gate electrode comprising silicon and formed via a gate insulating film over said semiconductor substrate;

said source region of a second conductivity type formed at the main surface of said semiconductor substrate; and

said drain region of said second conductivity type formed at the main surface of said semiconductor substrate;

wherein a metal silicide film is formed on said gate electrode and on said source region, and no metal silicide film is formed on said drain region,

wherein a field plate electrode with a side wall spacer shape is formed via a first insulating film on a side surface of said gate electrode located over said drain region,

wherein a second insulating film is formed over said field plate electrode and over said drain region such that a part of said field plate electrode is exposed from said second insulating film,

wherein said metal silicide film is also formed on an exposed surface of said field plate electrode,

wherein an interlayer insulating film is formed over said semiconductor substrate, said gate electrode, said source region, said drain region, said field plate electrode and each of said metal silicide films, and

wherein said metal silicide films are formed from a same silicide formation layer.

2. The semiconductor device according to claim 1 , wherein said field plate electrode comprises a silicon film.

3. The semiconductor device according to claim 1 , wherein said field plate electrode is formed by etch-back processing of a conductor film.

4. The semiconductor device according to claim 1 , wherein said metal silicide film is formed on an upper surface of said gate electrode.

5. The semiconductor device according to claim 1 ,

wherein said drain region contains a low impurity concentration portion and a high impurity concentration portion, said low impurity concentration portion being located nearer to a channel forming region of said LDMOSFET than is said high impurity concentration portion, and

wherein said field plate electrode is disposed vertically above said low impurity concentration portion of said drain region.

6. The semiconductor device according to claim 5 , wherein said field plate electrode comprises a silicon film.

7. The semiconductor device according to claim 5 , wherein said field plate electrode is formed by etch-back processing of a conductor film.

8. The semiconductor device according to claim 5 , wherein said field plate electrode does not extend to an upper surface of said gate electrode.

9. The semiconductor device according to claim 1 , wherein said field plate electrode does not extend to an upper surface of said gate electrode.

10. A semiconductor device comprising an LDMOSFET including a source region, a drain region, and a gate electrode formed at a main surface of a semiconductor body, said device comprising:

said semiconductor body of a first conductivity type;

said gate electrode formed via a gate insulating film on said semiconductor body;

said source region of said second conductivity type formed in said semiconductor body;

said drain region of said second conductivity type formed in said semiconductor body; and

a field plate electrode with a side wall spacer shape formed via a first insulating film on a side surface of said gate electrode located above said drain region,

wherein a second insulating film is formed over said field plate electrode and over said drain region such that a part of said field plate electrode is exposed from said second insulating film,

wherein metal silicide films are respectively formed on said gate electrode, on said source region and on an exposed surface of said field plate electrode,

wherein a metal silicide film is not formed on said drain region,

wherein an interlayer insulating film is formed over said semiconductor substrate, said gate electrode, said source region, said drain region, said field plate electrode and each of said metal silicide films, and

wherein said metal silicide films are formed from a same silicide formation layer.

11. The semiconductor device according to claim 10 , wherein said field plate electrode does not extend to an upper surface of said gate electrode.

12. The semiconductor device according to claim 10 , wherein said field plate electrode comprises a silicon film.

13. The semiconductor device according to claim 10 , wherein said field plate electrode is formed by etch-back processing a conductor film.

14. The semiconductor device according to claim 10 , wherein said semiconductor device is a high-frequency power amplification module.

15. The semiconductor device according to claim 10 ,

wherein said drain region contains a low impurity concentration portion and a high impurity concentration portion, said low impurity concentration portion being located nearer to a channel forming region of said LDMOSFET than is said high impurity concentration portion, and

wherein said field plate electrode is disposed vertically above said low impurity concentration portion of said drain region.

16. The semiconductor device according to claim 15 , wherein said field plate electrode does not extend to an upper surface of said gate electrode.

17. The semiconductor device according to claim 15 , wherein said field plate electrode comprises a silicon film.