Semiconductor integrated circuit device with capacitor of crown structure and method of manufacturing the same
View Patent ↗A semiconductor integrated circuit device includes a plurality of capacitor elements, which are separated from each other by a first insulating film on a plane. Each of the plurality of capacitor elements has a lower electrode, a dielectric film, and an upper electrode, and the lower electrode has a crown structure. At least one of the lower electrode and the upper electrode has a laminate structure composed of a plurality of conductive films. An outermost film of the laminate structure on a side of the dielectric film is a ruthenium film, and a portion of the laminate structure other than the outermost film has higher selective growth than the first insulating film with respect to the ruthenium film. Here, the first insulating film is desirably a tantalum oxide film.
1. A method of manufacturing a semiconductor integrated circuit device comprising the steps of:
(a) forming a second insulating film on a first insulating film;
(b) removing said second insulating film partially;
(c) forming at least one lower electrode on said first insulating film exposed after said second insulating film is removed partially, said lower electrode having a crown structure and comprising a plurality of conductive films,
wherein an outermost film of said lower electrode is a ruthenium (RU) film, and a portion of said lower electrode other than said outermost film is a central film, and said central film has higher selective growth of said ruthenium film than said ruthenium film formed on said second insulating film;
(d) forming a dielectric film on a surface of said crown structure and on said second insulating film between crown structures of lower electrodes formed in step (c); and
(e) forming an upper electrode on said dielectric film, wherein said step of (b) removing comprises the steps of:
(f) forming a third insulating film on said second insulating film; and
(g) forming a plurality of holes passing through said second insulating film and said third insulating film to said first insulating film, and
said step of (c) forming said lower electrode comprises the steps of:
(h) forming said central film on an inner wall of each of said plurality of holes on said third insulating film;
(i) removing said central film on said third insulating film;
(J) removing said third insulating film; and
(k) forming said ruthenium film on said central film, and wherein said step of (h) forming said central film comprises the steps of:
forming an amorphous silicon film on said inner wall of each of said plurality of holes and on said third insulating film; and
forming a conductive polysilicon film by heat-treating said amorphous silicon film.
2. The method of manufacturing a semiconductor integrated circuit device according to claim 1 , wherein said step of (c) forming said lower electrode further comprises the step of forming suicide on a surface of said conductive polysilicon film.
3. A method of manufacturing a semiconductor integrated circuit device, comprising the steps of:
(a) forming a second insulating film on a first insulating film, at least one of said first and second insulating films including tantalum oxide;
(b) removing said second insulating film partially;
(c) forming at least one lower electrode on said first insulating film exposed after said second insulating film is removed partially, said lower electrode having a crown structure and comprising a plurality of conductive films,
wherein an outermost film of said lower electrode is a ruthenium (RU) film, and a portion of said lower electrode other than said outermost film is a central film, and said central film has higher selective growth of said ruthenium film than said ruthenium film formed on said second insulating film;
(d) forming a dielectric film on a surface of said crown structure and on said second insulating film between crown structures of lower electrodes formed in step (c), said dielectric film being heat-treated in both an oxygen-containing atmosphere and a non-oxidizing atmosphere; and
(e) forming an upper electrode on said dielectric flint, wherein said step of (b) removing comprises the steps of:
(f) forming a third insulating film on said second insulating film; and
(g) fanning a plurality of holes passing through said second insulating film and said third insulating film to said first insulating film, and
said step of (c) forming said lower electrode comprises the steps of:
(h) forming said central film on an inner wall of each of said plurality of holes on said third insulating film;
(i) removing said central film on said third insulating film;
(j) removing said third insulating film; and
(k) forming said ruthenium film on said central film.
4. The method of manufacturing a semiconductor integrated circuit device according to claim 3 , wherein said dielectric film is formed of tantalum oxide.
5. The method of manufacturing a semiconductor integrated circuit device according to claim 3 , wherein said heat-treatment of step (d) is performed at about 700 degrees celsius for about one minute.