Semiconductor device and a method of manufacturing the same
In connection with a semiconductor device including a capacitor element there is provided a technique capable of improving the reliability of the capacitor element. A capacitor element is formed in an element isolation region formed over a semiconductor substrate. The capacitor element includes a lower electrode and an upper electrode formed over the lower electrode through a capacitor insulating film. Basically, the lower electrode and the upper electrode are formed from polysilicon films and a cobalt silicide film formed over the surfaces of the polysilicon films. End portions of the cobalt silicide film formed over the upper electrode are spaced apart a distance from end portions of the upper electrode. Besides, end portions of the cobalt silicide film formed over the lower electrode are spaced apart a distance from boundaries between the upper electrode and the lower electrode.
1. A semiconductor device having a capacitor element comprising:
(a) a first electrode of the capacitor element formed over a semiconductor substrate;
(b) a capacitor insulating film of the capacitor element formed over the first electrode,
wherein the capacitor insulating film includes an upper portion, a first middle portion and a first lower portion in a cross section of a first direction along an upper surface of the semiconductor substrate,
wherein the upper portion of the capacitor insulating film is formed over the first electrode and extends along an upper surface of the first electrode,
wherein the first lower portion of the capacitor insulating film is disposed below the upper portion of the capacitor insulating film and extends along the upper surface of the semiconductor substrate, and
wherein the first middle portion of the capacitor insulating film extends along one side surface of the first electrode and connects the upper portion of the capacitor insulating film and the first lower portion of the capacitor insulating film;
(c) a second electrode of the capacitor element formed over the capacitor insulating film so as to cover the upper portion, the first middle portion and the first lower portion of the capacitor insulating film,
wherein an upper surface of the second electrode includes a first part, a second part and a third part in the cross section of the first direction,
wherein the first part of the upper surface of the second electrode is disposed over the upper portion of the capacitor insulating film and overlaps the first electrode in plan view,
wherein the second part of the upper surface of the second electrode is disposed over the first lower portion of the capacitor insulating film in plan view, and
wherein the third part of the upper surface of the second electrode is disposed over the first middle portion of the capacitor insulating film and between the first part and the second part of the upper surface of the second electrode;
(d) a first metal silicide film formed over the first part of the upper surface of the second electrode;
(e) a second metal silicide film formed over the second part of the upper surface of the second electrode; and
(f) a first insulating film formed over the third part of the upper surface of the second electrode so as to separate the first metal silicide film from the second metal silicide film,
wherein the first insulating film extends from a position contacting the second metal silicide film to a position contacting the first metal silicide film, and
wherein, on one side of the first electrode in the cross section of the first direction, one part of the first insulating film is located above the first middle portion of the capacitor insulating film in a second direction perpendicular to the upper surface of the semiconductor substrate.
2. The semiconductor device according to claim 1 ,
wherein the first insulating film includes an upper portion, a middle portion and a lower portion in the first direction,
wherein the upper portion of the first insulating film is formed over the second electrode and extends along a direction parallel to an upper surface of the second electrode, and
wherein the lower portion of the first insulating film is disposed below the upper portion of the first insulating film and extends along a direction parallel to the upper surface of the semiconductor substrate,
wherein the middle portion of the first insulating film extends along a side surface of the second electrode and connect the upper portion of the first insulating film and the lower portion of the first insulating film, and
wherein a length of the upper portion of the first insulating film in the first direction is greater than the lower portion of the first insulating film in the first direction.
3. The semiconductor device according to claim 1 , further comprising:
a second insulating film formed over the semiconductor substrate so as to cover the capacitor element and the first insulating film, and
a first plug formed in the second insulating film so as to be electrically coupled to the second metal silicide film.
4. The semiconductor device according to claim 1 ,
wherein a part of upper surface of the first electrode is exposed from the capacitor insulating film and the second electrode in a cross section of a third direction perpendicular to the first direction and along the upper surface of the semiconductor substrate, and
wherein a third metal silicide film is formed over the part of the upper surface of the first electrode.
5. The semiconductor device according to claim 4 , further comprising:
a second insulating film formed over the semiconductor substrate so as to cover the capacitor element and the first insulating film, and
a second plug formed in the second insulating film so as to be electrically coupled to the third metal silicide film.
6. The semiconductor device according to claim 4 ,
wherein, in the cross section of the third direction, the first insulating film is formed over a part of the second electrode and a side face of the second electrode so as to separate the first metal silicide film from the third metal silicide film.
7. The semiconductor device according to claim 6 ,
wherein the first insulating film surrounds the first silicide film in plan view.
8. The semiconductor device according to claim 7 ,
wherein any plug is not formed in a region surrounded by the first insulating film.
9. The semiconductor device according to claim 1 ,
wherein a thickness of the second electrode is thinner than a thickness of the first electrode.
10. The semiconductor device according to claim 1 , further comprising:
a third insulating film is formed between the third part of the upper surface of the second electrode and the first insulating film,
wherein a length of the first insulating film in the cross section of the first direction is greater than a length of the third insulating film in the cross section of the first direction.
11. The semiconductor device according to claim 1 ,
wherein the capacitor insulating film further includes a second middle portion and a second lower portion in the cross section of the first direction,
wherein the second lower portion of the capacitor insulating film is disposed below the upper portion of the capacitor insulating film and extends along the upper surface of the semiconductor substrate,
wherein the second middle portion of the capacitor insulating film extends along another side surface of the first electrode and connects the upper portion of the capacitor insulating film and the second lower portion of the capacitor insulating film,
wherein the second electrode of the capacitor element is formed over the capacitor insulating film so as to further cover the second middle portion and the second lower portion of the capacitor insulating film,
wherein the upper surface of the second electrode further includes a fourth part and a fifth part in the cross section of the first direction,
wherein the fourth part of the upper surface of the second electrode is disposed over the second lower portion of the capacitor insulating film in plan view,
wherein the fifth part of the upper surface of the second electrode is disposed over the second middle portion of the capacitor insulating film and between the first part and the fourth part of the upper surface of the second electrode,
wherein a fourth metal silicide film is formed over the fourth part of the upper surface of the second electrode,
wherein the first insulating film is further formed over the fifth part of the upper surface of the second electrode so as to separate the first metal silicide film from the fourth metal silicide film,
wherein the first insulating film extends from a position contacting the fourth metal silicide film to the position contacting the first metal silicide film, and
wherein, on the other side of the first electrode in the cross section of the first direction, another part of the first insulating film is located above the second middle portion of the capacitor insulating film in the second direction.