Claims
- 1. A method of forming a capacitor of semiconductor devices comprising:
- a) forming insulating layers with an oxide film placed on top in sequence on a semiconductor substrate with a pattern formed thereon, and removing a predetermined portion of the insulating layers so as to form a contact hole;
- b) forming a lower electrode material layer of a capacitor on the oxide film over the semiconductor substrate containing the contact hole;
- c) removing the lower electrode material layer so as to expose a certain portion of the oxide film;
- d) undercutting the oxide film exposed by the removing of the lower electrode material layer;
- e) cleaning the surface containing the lower surface of the lower electrode material layer exposed by the undercutting of the oxide film; and
- f) carrying out a hemispherical grain (HSG) process in order to increase a surface area containing the lower surface of the lower electrode material layer exposed by the undercutting of the oxide film.
- 2. The method of claim 1, further comprising forming a side wall spacer on side walls of the insulating layers between the above a) forming of the insulating layers and b) the forming of the lower electrode material layer.
- 3. The method of claim 2, wherein the side wall spacer is formed as a nitride film.
- 4. The method of claim 1, further comprising forming an insulating film over the lower electrode material layer after cleaning the lower electrode material layer with its surface increased by the above HSG process.
- 5. The method of claim 4, wherein the cleaning of the lower electrode material layer with its surface area increased by the HSG process includes using an SC-1 chemical.
- 6. The method of claim 1, wherein films under the oxide film are intermediate insulating layers.
- 7. The method of claim 6, wherein the intermediate insulating layer is a boron phosphorus silicate glass film.
- 8. The method of claim 1, wherein the oxide film is a high temperature oxide.
- 9. The method of claim 1, wherein the forming of the oxide film includes forming a film with a thickness between 1,000 to 2,000 .ANG..
- 10. The method of claim 1, wherein the lower electrode material layer is a polysilicon film.
- 11. The method of claim 10, wherein the polysilicon film is an amorphous polysilicon film.
- 12. The method of claim 10, wherein the polysilicon film is formed with 7,000 to 12,000 .ANG. of thickness.
- 13. The method of claim 1, wherein the undercutting of the oxide film and the cleaning are carried out "in-situ" by using a bath containing different kinds of chemicals from one another.
- 14. The method of claim 13, wherein the undercutting and the cleaning are carried out by performing a first bath process using chemicals having HF and NH.sub.4 F mixed together, a second bath process using SC-1 chemical, and a third bath process using HF chemical in sequence.
- 15. The method of claim 14, wherein the first bath process is carried out at a temperature of 20 to 30.degree. C. for 90 to 120 sec.
- 16. The method of claim 14, wherein the second bath process is carried out at a temperature of 60 to 80.degree. C. for 300 to 600 sec.
- 17. The method of claim 14, wherein the third bath process is carried out at a temperature of 20 to 30.degree. C. for 60 to 180 sec.
- 18. The method of claim 1, wherein the HSG process includes a seeding process and an annealing process carried out in sequence.
- 19. The method of claim 18, wherein the seeding process and the annealing process are carried out "in-situ" inside one processing chamber.
- 20. The method of claim 18, wherein the seeding process is carried out at a temperature of 550 to 570.degree. C. with 10.sup.-2 to 10.sup.-4 Torr of pressure for 45 to 55 min.
- 21. The method of claim 18, wherein the seeding process includes supplying SiH.sub.4 gas to presupplied He (helium) gas at a rate of 80 to 140 cc per min.
- 22. The method of claim 18, wherein the seeding process includes maintaining a mixed ratio of He gas and SiH.sub.4 gas at 1 to 1.5:1.
- 23. The method of claim 18, wherein the annealing process is carried out at a temperature of 550 to 570.degree. C. with 10.sup.-7 to 10.sup.-9 Torr pressure for 50 to 60 min.
- 24. A method of forming a capacitor of semiconductor devices comprising:
- a) forming multi-layers including an intermediate insulating layer and an oxide film in sequence over a semiconductor substrate with a predetermined pattern thereon, and removing a certain portion of the above multi-layers so as to form a contact hole;
- b) forming a side wall spacer with a nitride film on the side walls of the multi-layers including the contact hole;
- c) forming an amorphous polysilicon film, serving as a lower electrode material layer of a capacitor, over a semiconductor substrate having the side wall spacer and the contact hole;
- d) removing a part of the amorphous polysilicon film such that a certain portion of the oxide film is exposed;
- e) undercutting the oxide film exposed by the removing of the amorphous polysilicon film;
- f) cleaning the surface including the lower surface of the amorphous polysilicon film exposed by the undercutting of the oxide film;
- g) carrying out a hemispherical grain (HSG) process such that a surface area including the lower surface of the amorphous polysilicon film exposed by the undercutting of the oxide film is increased;
- h) cleaning the amorphous polysilicon film with its surface area increased by the HSG process; and
- i) forming an insulating film over the amorphous polysilicon film.
- 25. The method of claim 24, wherein the undercutting and the cleaning are carried out by "in situ" performing a first bath process using chemicals having HF and NH.sub.4 F mixed together, a second bath process using SC-1 chemical, and a third bath process using HF chemical.
- 26. The method of claim 25, wherein the first bath process is carried out at a temperature of 20 to 30.degree. C. for 90 to 120 sec, the second bath process is carried out at a temperature of 60 to 80.degree. C. for 300 to 600 sec, and the third bath process is carried out at a temperature of 20 to 30.degree. C. for 60 to 180 sec.
Priority Claims (1)
Number |
Date |
Country |
Kind |
97-66287 |
Dec 1997 |
KRX |
|
Parent Case Info
This application claims priority under 35 U.S.C. .sctn.119 to Korean Patent Application No, 97-66287 filed Dec. 5, 1997, which is hereby incorporated by reference in its entirety.
US Referenced Citations (5)