SEMICONDUCTOR DEVICE AND METHOD OF MANUFACTURING THEREOF
Disclosed is a semiconductor device including: a titanium nitride film formed over a semiconductor substrate and a tungsten film formed over the titanium nitride film. The titanium nitride film contains carbon and the tungsten film contains boron. A tungsten hexafluoride gas and a diborane gas are used in formation of the tungsten film.
1 . A semiconductor device, comprising:
a titanium nitride film comprising carbon, the titanium nitride film being formed over a semiconductor substrate; and
a tungsten film comprising boron, the tungsten film being formed over the titanium nitride film.
2 . A semiconductor device according to claim 1 , wherein the titanium nitride film is amorphous.
3 . A semiconductor device according to claim 1 , wherein the titanium nitride film has a carbon concentration of 3×10 20 atoms/cm 3 or more and 7×10 20 atoms/cm 3 or less.
4 . A semiconductor device according to claim 1 , wherein the titanium nitride film has a thickness of 3 nm or more and 5 nm or less.
5 . A semiconductor device according to claim 1 , wherein the tungsten film has a grain size of 80 nm or more and 120 nm or less.
6 . A semiconductor device according to claim 1 , further comprising an insulating film provided between the semiconductor substrate and the titanium nitride film.
7 . A semiconductor device, comprising:
a gate groove provided in a semiconductor substrate;
an insulating film provided so as to cover a surface of the gate groove;
a titanium nitride film comprising carbon, the titanium nitride film being provided over the insulating film; and
a tungsten film provided over the titanium nitride film.
8 . A semiconductor device according to claim 7 , wherein the titanium nitride film is amorphous.
9 . A semiconductor device according to claim 7 , wherein the titanium nitride film has a carbon concentration of 3×10 20 atoms/cm 3 or more and 7×10 20 atoms/cm 3 or less.
10 . A semiconductor device according to claim 9 , wherein the titanium nitride film has a thickness of 3 nm or more and 5 nm or less.
11 . A semiconductor device according to claim 7 , wherein the tungsten film comprises boron.
12 . A semiconductor device according to claim 11 , wherein the tungsten film has a grain size of 80 nm or more and 120 nm or less.
13 . A semiconductor device according to claim 7 , wherein the insulating film comprises a gate insulating film comprising a silicon oxide film.
14 . A semiconductor device according to claim 13 , wherein the titanium nitride film and the tungsten film form a word line.
15 . A semiconductor device according to claim 14 , further comprising diffusion layers provided in portions of the semiconductor substrate on both sides of the gate groove.
16 . A semiconductor device, comprising:
an element isolation region provided in a semiconductor substrate and defining an active region;
a groove provided in a surface layer of the semiconductor substrate, the groove extending in a first direction intersecting with the element isolation region and the active region;
a gate insulating film covering a surface of the groove for a gate electrode;
a buried gate electrode formed so as to be buried at a bottom portion of the groove, the buried gate electrode being formed as a word line; and
a pair of diffusion layers that is provided on an upper surface of the semiconductor substrate, and is located on both sides of the groove for a gate electrode in the active region,
wherein the buried gate electrode comprises a titanium nitride film and a tungsten film, the titanium nitride film being provided on the gate insulating film and comprising carbon, the tungsten film being provided on the titanium nitride film.
17 . A semiconductor device according to claim 16 , wherein the titanium nitride film is amorphous, and has a carbon concentration of 3×10 20 atoms/cm 3 or more and 7×10 20 atoms/cm 3 or less.
18 . A semiconductor device according to claim 16 , wherein the tungsten film comprises boron.
19 . A semiconductor device according to claim 16 , further comprising a bit line electrically connected to one diffusion layer of the pair of diffusion layers and extending in a second direction intersecting with the first direction.
20 . A semiconductor device according to claim 19 , further comprising:
an interlayer insulating film provided so as to cover the bit line;
a contact plug electrically connected to another diffusion layer of the pair of diffusion layers and provided in the interlayer insulating film; and
a capacitor electrically connected to the contact plug.