Claims
- 1. A field effect transistor comprising:
- a monocrystalline unitary substrate of one conductivity type, said substrate having a surface and uniform dopant concentration;
- a region in said substrate adjacent to said surface and having a conductivity of a second conductivity type;
- a V-shaped recess in said substrate extending from said surface through said region of said second conductivity type, said recess being defined by recess surfaces;
- a second region of said second conductivity type in said unitary substrate, said second region being formed adjacent to said recess surface at least at the tip of the V by implanting ions through an aperture that overlies and is smaller than the top of said V:
- an oxide layer covering the surfaces of the V-shaped recess; and
- a gate electrode material covering at least a portion of said oxide layer in said V-shaped recess.
- 2. A field effect transistor according to claim 1 which further includes:
- a third region in said unitary substrate, portions of said third regions being adjacent to said second region, said third region being of said one conductivity type but with a greater concentration of ions and being formed by implanting ions through an aperture that overlies and is smaller than the top of said V.
- 3. A field effect transistor according to claim 2 wherein:
- said third region is larger than and includes said second region.
- 4. A field effect transistor according to claim 3 wherein:
- said second region is formed by the implantation of phosphorous ions and said third region is formed by implantation of boron ions.
- 5. A field effect transistor comprising:
- a monocrystalline unitary substrate of one conductivity type, said substrate having a surface and uniform dopant concentration;
- a region in said substrate adjacent to said surface and having a conductivity of a second conductivity type;
- a V-shaped recess in said substrate extending from said surface through said region of said second conductivity type, said recess being defined by recess surfaces;
- a second region of said second conductivity type in said unitary substrate, said second region being formed adjacent to said recess surfaces at least at the tip of the V by implanting ions through an aperture that overlies and is smaller than the top of said V;
- a third region of said one conductivity type but with a greater concentration of ions, portions of said third region being formed adjacent to said second region by ion implantation through said aperture;
- an oxide layer covering the surfaces of said V-shaped recess; and
- a gate electrode layer covering at least a portion of said oxide layer in said V-shaped recess.
- 6. A field effect transistor according to claim 5 wherein:
- said third region is provided with a dopant concentration to have a greater conductivity of said one conductivity type than said crystalline substrate and said second region has a dopant concentration to provide a similar dopant concentration of said second conductivity type so as to provide an increased capacitance at the junction between said second and third regions.
- 7. A field effect transistor according to claim 5 wherein:
- the ions in said third region are implanted to a depth of 0.4 to 0.9 microns and the ions in said second region are implanted to a depth of 0.1 to 0.3 microns.
- 8. A field effect transistor according to claim 5 wherein:
- the ions implanted in said second region are phosphorous and the ions implanted in said third region are boron.
RELATED U.S. PATENT APPLICATIONS
This is a continuation of application Ser. No. 864,383, filed Dec. 27, 1977, now abandoned.
U.S. Patent applications directly or indirectly related to the subject application are as follows:
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
4003036 |
Jenne |
Jan 1977 |
|
4119996 |
Jhabuala |
Oct 1978 |
|
Continuations (1)
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Number |
Date |
Country |
Parent |
864383 |
Dec 1977 |
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