Manufacturing method of polymetal gate electrode
When an oxidation treatment for regenerating a gate insulating film 6 is performed after forming gate electrodes 7 A of a polymetal structure in which a WN x film and a W film are stacked on a polysilicon film, a wafer 1 is heated and cooled under conditions for reducing a W oxide 27 on the sidewall of each gate electrode 7 A. As a result, the amount of the W oxide 27 to be deposited on the surface of the wafer 1 is reduced.
1. A method for manufacturing a semiconductor integrated circuit device, comprising the steps of:
(a) forming a refractory metal film over a first principal surface of a wafer;
(b) heating the first principal surface of the wafer having the refractory metal film up to a first temperature of 600 degrees centigrade or more under conditions for reducing an oxide of the refractory metal;
(c) subjecting a portion of or over the first principal surface of the wafer containing silicon as a main component to an oxidation treatment at the first temperature in a mixed gas atmosphere containing hydrogen, and moisture catalytically synthesized from oxygen and hydrogen without oxidizing the refractory metal film; and
(d) washing the first principal surface of the wafer by a neutral or weakly alkaline water or chemical solution, substantially not containing hydrogen peroxide, after the step (c).
2. The method for manufacturing a semiconductor integrated circuit device according to claim 1 , further comprising the step of:
cooling the first principal surface of the wafer down to a second temperature of less than 500 degrees centigrade under reducing conditions for the refractory metal after the step (c).
3. The method for manufacturing a semiconductor integrated circuit device according to claim 2 , wherein the second temperature is 400 degrees centigrade.
4. The method for manufacturing a semiconductor integrated circuit device according to claim 3 , wherein the second temperature is 300 degrees centigrade.
5. The method for manufacturing a semiconductor integrated circuit device according to claim 4 , wherein the second temperature is 200 degrees centigrade.
6. The method for manufacturing a semiconductor integrated circuit device according to claim 5 , wherein the second temperature is 100 degrees centigrade.
7. The method for manufacturing a semiconductor integrated circuit device according to claim 6 , wherein the second temperature falls within a range of from 70 degrees centigrade to 20 degrees centigrade.
8. The method for manufacturing a semiconductor integrated circuit device according to claim 1 , wherein the portion containing silicon as a main component includes a silicon base surface region containing silicon as a main component, which constitutes at least a part of the first principal surface of the wafer, and a silicon base film region containing silicon as a main component over the first principal surface of the wafer.
9. The method for manufacturing a semiconductor integrated circuit device according to claim 8 , wherein the pressure of the mixed gas atmosphere is an atmospheric pressure or falls in a subatmospheric region.
10. The method for manufacturing a semiconductor integrated circuit device according to claim 9 , wherein the mixed gas contains a nitrogen gas, an argon gas, or a helium gas.
11. The method for manufacturing a semiconductor integrated circuit device according to claim 1 , wherein the refractory metal film contains molybdenum or tungsten as a main component.
12. A method for manufacturing a semiconductor integrated circuit device, comprising the steps of:
(a) forming a refractory metal film over a first principal surface of a wafer;
(b) heating the first principal surface of the wafer having the refractory metal film up to a first temperature of 600 degrees centigrade or more by lamp heating under conditions for reducing an oxide of the refractory metal film;
(c) subjecting a portion of or over the first principal surface of the wafer containing silicon as a main component to an oxidation treatment at the first temperature in a mixed gas atmosphere containing hydrogen and moisture without oxidizing the refractory metal film; and
(d) washing the first principal surface of the wafer by a neutral or weakly alkaline water or chemical solution substantially not containing hydrogen peroxide, after the step (c).
13. The method for manufacturing a semiconductor integrated circuit device according to claim 12 , further comprising the step of:
cooling the first principal surface of the wafer down to a second temperature of less than 500 degrees centigrade under reducing conditions for the refractory metal film after the step (c).
14. The method for manufacturing a semiconductor integrated circuit device according to claim 13 , wherein the second temperature is 400 degrees centigrade.
15. The method for manufacturing a semiconductor integrated circuit device according to claim 14 , wherein the second temperature is 300 degrees centigrade.
16. The method for manufacturing a semiconductor integrated circuit device according to claim 15 , wherein the second temperature is 200 degrees centigrade.
17. The method for manufacturing a semiconductor integrated circuit device according to claim 16 , wherein the second temperature is 100 degrees centigrade.
18. The method for manufacturing a semiconductor integrated circuit device according to claim 17 , wherein the second temperature falls within a range of from 70 degrees centigrade to 20 degrees centigrade.
19. The method for manufacturing a semiconductor integrated circuit device according to claim 12 , wherein the portion containing silicon as a main component includes a silicon base surface region containing silicon as a main component, which constitutes at least a part of the first principal surface of the wafer, and a silicon base film region containing silicon as a main component over the first principal surface of the wafer.
20. A method for manufacturing a semiconductor integrated circuit device, comprising the steps of:
(a) forming a film pattern including a refractory metal film over a first principal surface of a wafer;
(b) heating the first principal surface of the wafer including the film pattern up to a first temperature of 600 degrees centigrade or more under conditions for reducing an oxide of the refractory metal film;
(c) forming an insulating film over the first principal surface of the wafer including the film pattern at the first temperature by chemical vapor deposition; and
(d) cooling the first principal surface of the wafer over which the insulating film has been formed by the chemical vapor deposition down to a second temperature of less than 500 degrees centigrade under conditions for reducing an oxide of the refractory metal film.
21. The method for manufacturing a semiconductor integrated circuit device according to claim 20 , wherein the insulating film is a silicon nitride film.
22. The method for manufacturing a semiconductor integrated circuit device according to claim 20 , wherein the heating step is performed in a gas atmosphere containing an ammonia gas.
23. A method for manufacturing a semiconductor integrated circuit device, comprising the steps of:
(a) forming a silicon-base film including germanium over a gate insulating film over a silicon-base surface portion of a first major surface of wafer;
(b) forming a barrier metal film over the silicon-base film;
(c) forming a refractory metal film over the barrier metal film;
(d) forming a first silicon nitride film by plasma CVD over the refractory metal film;
(e) performing heat treatment to the first silicon nitride film by lamp annealing;
(f) forming a second silicon nitride film by low pressure CVD over the first silicon nitride film; and
(g) patterning a gate electrode by dry etching the refractory metal film, the barrier metal film, the silicon-base film, the first silicon nitride film, and the second silicon nitride film.
24. A method for manufacturing a semiconductor integrated circuit device according to claim 23 , wherein the composition of germanium in the silicon-base film is 5% to about 50%.
25. A method for manufacturing a semiconductor integrated circuit device according to claim 23 , wherein the film forming temperature of the first silicon nitride film is about 480 degrees centigrade.
26. A method for manufacturing a semiconductor integrated circuit device according to claim 23 , wherein the film forming temperature of the second silicon nitride film is about 780 degrees centigrade.
27. A method for manufacturing a semiconductor integrated circuit device according to claim 23 , wherein the lamp annealing temperature of the first silicon nitride film is about 950 degrees centigrade.