1-7. (canceled)
8. A method for culturing mesenchymal stem cells, which comprises growing said cells in a serum-free composition comprising FGF-2, LIF, SCF, pantotenate, biotin and selenium.
9. The method according to claim 8, wherein the serum-free composition further comprises EGF, PDGFbb, IGF-1, ascorbic acid, cholesterol, albumin, \u03b2-mercaptoethanol, dexamethasone and transferrin.
10. The method according to claim 8, wherein the serum-free composition further comprises a minimum essential medium.
11. The method according to claim 9, wherein the serum-free composition further comprises a minimum essential medium.
12. A serum-free culture medium for mesenchymal stem cells comprising FGF-2, LIF, SCF, pantotenate, biotin and selenium.
13. The serum-free culture medium according to claim 12, further comprising EGF, PDGFbb, IGF-1, ascorbic acid, cholesterol, albumin, \u03b2-mercaptoethanol, dexamethasone and transferrin.
14. The serum-free culture medium according to claim 12 further comprising a minimum essential medium.
15. The serum-free culture medium according to claim 12 further comprising a minimum essential medium.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method for fabricating a semiconductor device comprising the steps of:
forming a first conducting film over a semiconductor substrate having a first region and a second region;
patterning the first conducting film in the first region to form a first gate electrode in the first region;
forming by thermal oxidation an oxide film on the surface of the semiconductor substrate and a side wall of the first gate electrode;
forming a first sidewall spacer of a first insulating film on the side wall of the first gate electrode with the oxide film formed on;
removing the oxide film formed on the surface of the semiconductor substrate with the first sidewall spacer as a mask; and
forming a second sidewall spacer of a second insulating film on the side wall of the first gate electrode with the oxide film and the first sidewall spacer formed on.
2. A method for fabricating a semiconductor device according to claim 1,
further comprising, after the step of removing the oxide film and before the step of forming the second sidewall spacer, the step of: patterning the first conducting film in the second region to form a second gate electrode in the second region,
in the step of forming a second sidewall spacer, the second sidewall spacer being also formed on a side wall of the second gate electrode.
3. A method for fabricating a semiconductor device according to claim 1, further comprising:
before the step of forming the first conducting film, the step of forming a second conducting film in the first region, and
after the step of forming the first gate electrode, the step of pattering the second conducting film with the first gate electrode as a mask to form a floating gate of the second conducting film.
4. A method for fabricating a semiconductor device according to claim 1, wherein
in the step of removing the oxide film, the oxide film is removed so that a residual film thickness of the oxide film on a surface of the semiconductor substrate after the oxide film has been etched is thinner than a film thickness of a gate insulating film of a transistor to be formed in the second region.
5. A method for fabricating a semiconductor device according to any one of claim 1,
further comprising: after the step of forming the first conducting film and before the step of forming the first gate electrode, the step of forming a third insulating film on the first conducting film,
in the step of forming the oxide film, with the third insulating film as a mask, the semiconductor substrate and the first conducting film are oxidized.
6. A method for fabricating a semiconductor device according to claim 5, wherein
in the step forming the first gate electrode and the step of forming the second gate electrode, the third insulating film is used as an anti-reflection film for lithography.
7. A method for fabricating a semiconductor device according to claim 5, wherein
the third insulating film is removed when the second sidewall spacer is formed.
8. A method for fabricating a semiconductor device according to claim 1,
further comprising, after the step of forming the second sidewall spacer, the step of forming a silicide film selectively on the semiconductor substrate and the first gate electrode.
9. A method for fabricating a semiconductor device according to claim 1, wherein
in the step of removing the oxide film, the oxide film is etched by wet etching.
10. A method for fabricating a semiconductor device according to claim 1, wherein
the first insulating film is a silicon nitride film, and the second insulating film is a silicon oxide film.