Claims
- 1. A MESFET structure comprising:
- a semiconductor substrate having a first surface and a second surface and being a first conductivity type;
- a semiconductor layer of the first conductivity type disposed on said first surface of said substrate;
- a drain contact disposed on said second surface of said substrate;
- conductive regions of a second conductivity type disposed in said semiconductor layer and being separated from each other by a distance;
- channel regions of the first conductivity type disposed above said conductive regions;
- source regions of the first conductivity type disposed in said channel regions;
- Schottky gate contacts contacting said channel regions; and
- a shielding region, separate from said gate contacts, contacting said semiconductor layer between said conductive regions.
- 2. The structure of claim 1 wherein the shielding region is disposed in the semiconductor layer and is of the second conductivity type.
- 3. The structure of claim 1 wherein the shielding region comprises a contact disposed on the surface of the semiconductor layer.
- 4. The structure of claim 3 wherein the shielding region further comprises a relatively wide band gap material disposed between the surface of the semiconductor layer and the contact.
- 5. The structure of claim 4 wherein the substrate, the semiconductor layer, the channel regions and the material disposed between the surface of said semiconductor material and the contact all comprise compound semiconductor materials.
- 6. The structure of claim 5 wherein the compound semiconductor material comprises gallium arsenide.
- 7. The structure of claim 6 wherein the doping concentrations are on the order of 10.sup.18 atoms cm.sup.-3 for the substrate, 10.sup.16 atoms cm.sup.-3 for the semiconductor layer, 10.sup.17 atoms cm.sup.-3 for the channel regions and the conductive regions and 10.sup.16 atoms cm.sup.-3 for the material disposed between the surface of said semiconductor material and the contact.
- 8. A MESFET structure comprising:
- a semiconductor substrate having a first surface and a second surface and being of a first conductivity type;
- a semiconductor layer of the first conductivity type disposed on said first surface of said substrate;
- a drain contact disposed on said second surface of said substrate;
- conductive regions of a second conductivity type disposed in said semiconductor layer and being separated from each other by a distance and contacted by at least one conductive region contact;
- channel regions of the first conductivity type disposed above said conductive regions and contacted by at lest one Schottky gate contact;
- source regions of the first conductivity type disposed in said channel regions and contacted by at lest one source contact; and
- a shielding region, separate from said at least one gate contact, contacting said semiconductor layer between said conductive regions.
- 9. A MESFET comprising:
- a gallium arsenide substrate having a first surface and a second surface and being of a first conductivity type;
- a gallium arsenide layer of the first conductivity type disposed on said first surface of said substrate;
- a drain contact disposed on said second surface of said substrate;
- conductive regions of a second conductivity type disposed in said gallium arsenide layer and being separated from each other by a distance;
- gallium arsenide channel regions of the first conductivity type disposed above said conductive regions;
- source regions of the first conductivity type disposed in said channel regions;
- Schottky gate contacts contacting said channel regions; and
- a shielding region, separate from said gate contacts, contacting said gallium arsenide layer between said conductive regions.
- 10. The transistor of claim 9 wherein the shielding region is disposed in the gallium arsenide layer and is of the second conductivity type.
- 11. The transistor of claim 9 wherein the shielding region comprises a contact on the surface of the gallium arsenide layer.
- 12. The transistor of claim 11 wherein the shielding region further comprises a layer of gallium arsenide disposed between the surface of the gallium arsenide layer and the contact.
Parent Case Info
This application is a continuation-in-part of prior application Ser. No. 07/498,123 filed Mar. 23, 1990 now abandoned.
US Referenced Citations (4)
Number |
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Date |
Kind |
4455565 |
Goodman et al. |
Jun 1984 |
|
4805003 |
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Feb 1989 |
|
4896196 |
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Jan 1990 |
|
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Non-Patent Literature Citations (1)
Entry |
Sze, S. M., Semiconductor Devices-Physics and Technology, p. 200, Apr. 30, 1985. |
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
498123 |
Mar 1990 |
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