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 comprising:
(a) a semiconductor device;
(b) an element isolation region formed over the semiconductor substrate; and
(c) a first capacitor element and a second capacitor element disposed spacedly from each other over the element isolation region,
the first capacitor element including:
(c1) a first lower electrode formed over the element isolation region;
(c2) a capacitor insulating film formed over the first lower electrode; and
(c3) an upper electrode formed over the capacitor insulating film,
the second capacitor element including:
(c4) a second lower electrode formed over the element isolation region;
(c5) the capacitor insulating film formed over the second lower electrode; and
(c6) the upper electrode formed over the capacitor insulating film,
wherein the first capacitor element and the second capacitor element have the capacitor insulating film and the upper electrode in common,
wherein the length of the upper electrode in a first direction is larger than the sum of the length of the first lower electrode in the first direction and the length of the second lower electrode in the first direction, the length of the upper electrode in a second direction intersecting the first direction is smaller than each of the length of the first lower electrode in the second direction and the length of the second lower electrode in the second direction,
wherein the first capacitor element is formed in a region where the upper electrode and the first lower electrode overlap each other planarly, the second capacitor element is formed in a region where the upper electrode and the second lower electrode overlap each other planarly,
wherein over a surface of the upper electrode, there exist a region where a metal silicide film is formed and a region where the metal silicide film is not formed, and
wherein the metal silicide film-formed region comprises a region spaced apart from an end region of the upper electrode in the second direction and a region spaced apart from a stepped region of the upper electrode in the first direction.
2. A semiconductor device according to claim 1 ,
wherein over a surface of the first lower electrode, there exist a region where the metal silicide film is formed and a region where the metal silicide film is not formed, the metal silicide film-formed region being a region spaced apart from a boundary region between the upper electrode and the first lower electrode in the second direction,
wherein over a surface of the second lower electrode, there exist a region where the metal silicide film is formed and a region where the metal silicide film is not formed,
wherein the metal silicide film-formed region is a region spaced apart from a boundary region between the upper electrode and the second lower electrode.
3. A semiconductor device according to claim 1 ,
wherein a first plug coupled electrically to the upper electrode is formed in a region of the upper electrode not overlapping with the first lower electrode planarly and also in a region of the upper electrode not overlapping with the second lower electrode planarly,
wherein a second plug coupled electrically to the first lower electrode is formed in a region of the first lower electrode not overlapping with the upper electrode planarly, and
wherein a third plug coupled electrically to the second lower electrode is formed in a region of the second lower electrode not overlapping with the upper electrode planarly.
4. A semiconductor device according to claim 3 , wherein the first capacitor element and the second capacitor element are coupled in parallel with each other.