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US 4,814,292 AGranted
Process of fabricating a semiconductor device involving densification and recrystallization of amorphous silicon
AssigneeOki Electric Industry Co., Ltd.
InventorsMasayoshi Sasaki, Teruo Katoh
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Abstract
In a process of fabricating a semiconductor device, an amorphous semiconductor layer is formed on a substrate, densified by heat-treatment, and is subjected to further heat-treatment to be changed into a polycrystalline semiconductor layer. A MOS transistor can be formed using the polycrystalline semiconductor layer.
Claims8
A process of fabricating a semiconductor device comprising the steps of:
- (a) forming an amorphous silicon layer on a substrate by vacuum vapor deposition in a vacuum of not higher than about 10.sup.-5 Pa, at a substrate temperature of not more than about 200.degree. C., and at a deposition rate of not lower than about 50 nm/minute;
- (b) heat-treating the amorphous silicon layer in the same vacuum maintained from step (a) at a substrate temperature of about 300.degree. to 450.degree. C. for about 10 minutes to 1 hour to provide a densified amorphous silicon layer;
- (c) heat-treating the densified amorphous silicon layer at a temperature of about 550.degree. to 650.degree. C. for about 3 to 25 hours to change the densified amorphous silicon layer into a polycrystalline silicon layer;
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- (d) forming an MOS transistor by a process including photoetching the polycrystalline silicon layer to produce a desired pattern in the polycrystalline silicon layer, and doping the polycrystalline silicon layer with an impurity.
2 more elements
A process of fabricating a polycrystalline silicon layer comprising the steps of:
- (a) forming an amorphous silicon layer on a substrate by vacuum vapor deposition in a vacuum of not higher than about 10.sup.-5 Pa, at a substrate temperature of not more than about 200.degree. C., and at a deposition rate of not lower than about 50 nm/minute;
- (b) heat-treating the amorphous silicon layer in the same vacuum maintained from step (a) at a substrate temperature of about 300.degree. to 450.degree. C. for about 10 minutes to 1 hour to provide a densified amorphous silicon layer;
- and
- (c) heat-treating the densified amorphous silicon layer at a temperature of about 550.degree. to 650.degree. C. for about 3 to 25 hours to change the densified amorphous silicon layer into a polycrystalline silicon layer.
1 more element
Dependencies are inferred from the claim text.