Claims
- 1. A process for producing a semiconductor device, which comprises:forming an underlying film on a semiconductor substrate; forming a first amorphous layer, doped with an impurity selected from group III and group V elements, on the underlying film; forming a second amorphous layer, having a lower concentration of the impurity than the first amorphous layer, on the first amorphous layer; and heat-treating the first and second amorphous layers to form a polycrystalline layer by crystallization.
- 2. A process according to claim 1, wherein the polycrystalline layer has a columnar structure.
- 3. A process according to claim 2, wherein the polycrystalline layer has a columnar structure.
- 4. A process for producing a semiconductor device, which comprises:forming an underlying film on a semiconductor substrate; depositing an amorphous layer on the underlying layer so as to make an impurity concentration higher in a lower portion of the amorphous layer than in an upper portion of the amorphous layer; patterning; and heat-treating the amorphous layer to form a polycrystalline layer by crystallization.
- 5. A process for producing a semiconductor device, which comprises:forming an underlying film on a semiconductor substrate; introducing an impurity gas containing an element selected from group III and group V elements; after said introducing the impurity gas, introducing a gas selected from SiH4 gas or Si2H6 gas together with the impurity gas, forming layers on the semiconductor substrate; and heat-treating thus formed layers.
- 6. A process according to claim 5, wherein the layers as a whole have an impurity concentration higher in a lower portion thereof, closer to the underlying film, than in an upper portion thereof.
Priority Claims (1)
Number |
Date |
Country |
Kind |
6-248310 |
Sep 1994 |
JP |
|
Parent Case Info
This application is a Divisional application of prior application Ser. No. 09/597,985, filed Jun. 19, 2000, now U.S. Pat. No. 6,204,155, which is a Continuation application of application Ser. No. 08/880,445, filed Jun. 24, 1997, now U.S. Pat. No. 6,080,611, which is a Divisional application of application Ser. No. 08/527,942, filed Sep. 14, 1995, now U.S. Pat. No. 5,670,793.
US Referenced Citations (17)
Foreign Referenced Citations (7)
Number |
Date |
Country |
41 38 057 |
May 1992 |
DE |
2254960 |
Oct 1992 |
GB |
62-54423 |
Mar 1987 |
JP |
3-70126 |
Mar 1991 |
JP |
4-137724 |
May 1992 |
JP |
4-151823 |
May 1992 |
JP |
4-196311 |
Jul 1992 |
JP |
Continuations (1)
|
Number |
Date |
Country |
Parent |
08/880445 |
Jun 1997 |
US |
Child |
09/597985 |
|
US |