Claims
- 1. A schottky diode structure comprising:
- a first region of N-conductivity type semiconductor material having an upper boundary;
- an annular region of P-conductivity type semiconductor material disposed in contact with a periphery of the upper boundary;
- a second region of N-conductivity type semiconductor material having a lower boundary disposed in contact with both the first region and the annular region and having an upper surface wherein the annular region is at a depth below the upper surface and not at the upper surface; and
- a metal contact disposed on the upper surface in contact with the second region.
- 2. A structure as in claim 1 wherein the first region has an impurity concentration of no more than 1.times.10.sup.16 atoms per cubic centimeter.
- 3. A structure as in claim 1 wherein the second region has a impurity concentration of no less than 4.times.10.sup.18 atoms per cubic centimeter and no more than 4.times.10.sup.19 atoms per cubic centimeter.
- 4. A structure as in claim 1 wherein the metal contact comprises aluminum and silicon.
- 5. A structure as in claim 1 further comprising a buried layer of N-conductivity type semiconductor material disposed beneath and in contact with the first region.
- 6. A Schottky diode structure comprising:
- a first region of N-conductivity type semiconductor material having an upper surface;
- an annular region of P-conductivity type semiconductor material disposed to surround the first region at a selected depth below the upper surface and not at the upper surface;
- a metal contact disposed on the upper surface in contact with at least the first region; and
- wherein the first region has a surface N-type impurity concentration of more than 2.times.10.sup.18 atoms per cubic centimeter and less than 4.times.10.sup.19 atoms per cubic centimeter.
- 7. A structure as in claim 6 wherein the N-type impurity comprises phosphorus.
- 8. A structure as in claim 6 wherein the N-type impurity comprises arsenic.
- 9. A structure as in claim 8 wherein the N-type impurity concentration is about .times.10.sup.19 atoms per cubic centimeter.
- 10. A static random access memory cell including a first and a second Schottky diode each comprising:
- a first region of N-conductivity type semiconductor material having an upper surface;
- an annular region of P-conductivity type semiconductor material disposed to surround the first region at a selected location wherein the annular region is at a depth below the upper surface and not at the upper surface;
- a metal contact disposed on the upper surface in contact with at least the first region; and
- wherein the first region has a surface N-type impurity concentration of more than 2.times.10.sup.18 atoms per cubic centimeter and less than 4.times.10.sup.19 atoms per cubic centimeter.
- 11. A memory cell as in claim 10 further including:
- a first bipolar transistor having a base connected to a first node, a collector connected to a second node, and an emitter connected to a third node;
- a second bipolar transistor having a base connected to the second node, a collector connected to the first node, and an emitter connected to the third node; and
- wherein the first Schottky diode is connected between a fourth node and the first node and the second Schottky diode is connected between the fourth node and the second node.
- 12. A memory cell as in claim 11 further including first and second resistors connected in parallel with corresponding Schottky diodes.
Parent Case Info
This is a division of application Ser. No. 07/002,828 filed Jan. 13, 1987 and now abandoned.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
3924264 |
Dorler et al. |
Dec 1975 |
|
4538244 |
Sugo et al. |
Aug 1985 |
|
Foreign Referenced Citations (1)
Number |
Date |
Country |
5992575 |
May 1984 |
JPX |
Non-Patent Literature Citations (1)
Entry |
IBM Technical Disclosure Bulletin, Vol. 18 #6, p. 1829, Nov., 1975 by Freed et al. |
Divisions (1)
|
Number |
Date |
Country |
Parent |
2828 |
Jan 1987 |
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