SEMICONDUCTOR DEVICE WITH ELECTRODE INCLUDING INTERVENTION FILM
In a semiconductor device including a semiconductor substrate, a trench formed on the semiconductor substrate, an insulating film formed on a side wall of the trench, and an electrode formed on the insulating film. The electrode includes a first film made of first metal nitride, an intervention film made of silicon or of second metal silicide, and a second film made of third metal in this order.
1 . A semiconductor device comprising:
a semiconductor substrate;
a trench formed on the semiconductor substrate;
an insulating film formed on a side wall of the trench; and
an electrode formed on the insulating film, the electrode comprising a first film made of a first metal which is nitrided, an intervention film made of a silicon or of a second metal which is silicided, and a second film made of a third metal in this order.
2 . The semiconductor device as claimed in claim 1 , wherein the intervention film has a film thickness between 1 nm and 3 nm, both inclusive.
3 . The semiconductor device as claimed in claim 1 , wherein the first film, the intervention film, and the second film comprise films which are annealed.
4 . The semiconductor device as claimed in claim 1 , wherein the first metal comprises a high-melting metal.
5 . The semiconductor device as claimed in claim 1 , wherein each of the second metal and the third metal comprises a high-melting metal.
6 . The semiconductor device as claimed in claim 4 , wherein the high-melting metal is selected from a group consisting of tungsten, cobalt, titanium, nickel, molybdenum, and tantalum.
7 . The semiconductor device as claimed in claim 5 , wherein the high-melting metal is selected from a group consisting of tungsten, cobalt, titanium, nickel, molybdenum, and tantalum.
8 . The semiconductor device as claimed in claim 1 , wherein further comprises:
a plurality of active regions; and
an element isolation region enclosing the plurality of active regions,
wherein the electrode comprises a wire straddling the element isolation region and at least one of the active regions.
9 . The semiconductor device as claimed in claim 1 , wherein a most upper surface of the electrode is lower than a most upper surface of the semiconductor substrate.
10 . A semiconductor device comprising:
a semiconductor substrate;
first and second trenches which are formed on the semiconductor substrate and which extend in a first direction;
a first film made of a first metal which is nitrided, the first film being formed on side walls of the first and second trenches;
an intervention film which is formed on the side walls of the first and second trenches and which is formed on the first film, the intervention film being made of a silicon or of a second metal which is silicided;
a second film formed on the side walls of the first and second trenches, the second film being made of a third metal different from the first metal; and
a cap insulating film covering the first film, the intervention film, and the second film, the cap insulating film filling in upper portions of the first and second trenches.
11 . The semiconductor device as claimed in claim 10 , further comprising an insulating film between the side walls of the first and second trenches and the first film.
12 . The semiconductor device as claimed in claim 10 , wherein a most upper surface of the second film is lower than a most upper surface of the semiconductor substrate.
13 . The semiconductor device as claimed in claim 10 , wherein further comprises:
a plurality of active regions extending in a second direction different from the first direction; and
an element isolation region enclosing the plurality of active regions,
wherein the first and second trenches simultaneously cross at least one of the active regions.
14 . The semiconductor device as claimed in claim 13 , further comprising a contact plug formed on a most upper surface of the active region sandwiched between the first and second trenches.
15 . The semiconductor device as claimed in claim 10 , wherein the intervention film has a film thickness between 1 nm and 3 nm, both inclusive.
16 . The semiconductor device as claimed in claim 10 , wherein the first film, the intervention film, and the second film comprise films which are annealed.
17 . The semiconductor device as claimed in claim 10 , wherein the first metal comprises a high-melting metal.
18 . The semiconductor device as claimed in claim 10 , wherein each of the second metal and the third metal comprises a high-melting metal.
19 . The semiconductor device as claimed in claim 17 , wherein the high-melting metal is selected from a group consisting of tungsten, cobalt, titanium, nickel, molybdenum, and tantalum.
20 . The semiconductor device as claimed in claim 18 , wherein the high-melting metal is selected from a group consisting of tungsten, cobalt, titanium, nickel, molybdenum, and tantalum.