Patent US5900653A successfully refreshed from Google Patents.
US5900653A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High electron mobility transistor having thin, low resistance schottky contact layer
Assignee: Honda Motor Co Ltd
•
Filing: 1997-04-15
•
Granted: 1999-05-04
•
Expires: 2017-04-15
Abstract
Abstract A high electron mobility transistor has a double-heterojunction structure including a channel layer for developing therein an electron gas layer having a substantially uniform electron gas density, and upper and lower high-resistance wide-band gap layers disposed respectively over and beneath the channel layer. Each of the upper and lower high-resistance wide-band gap layers has a silicon-doped planar layer disposed therein. The upper high-resistance wide-band gap layer including a low-resistance wide-band gap layer disposed in an upper end region thereof remotely from the channel layer.
Inventors
- 👤 Toshifumi Suzuki
- 👤 Yamato Ishikawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 07:44
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/40; H10D30/47; H10D30/471; H10D30/473; H10D30/4732; H10D30/4738; B; B82; B82Y; B82Y10/00; H10D30/4735
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
121 words
A high electron mobility transistor comprising: a double-heterojunction structure comprising: a channel layer for developing therein an electron gas layer having a substantially uniform electron gas density; and upper and lower high-resistance wide-band gap layers disposed respectively over and beneath said channel layer, each of said upper and lower high-resistance wide-band gap layers having a silicon-doped planar layer disposed therein; said upper high-resistance wide-band gap layer including a low-resistance wide-band gap layer disposed in an upper end region thereof remotely from said channel layer, and wherein said low-resistance wide-band gap layer is doped with an impurity at a concentration ranging from 3×10 17 cm -3 to 1×10 18 cm -3 and has a thickness ranging from 40 Å to 120 Å.
Claim 2
Dependent Claim
121 words
A high electron mobility transistor comprising: a double-heterojunction structure comprising: a channel layer for developing therein an electron gas layer having a substantially uniform electron gas density; and upper and lower high-resistance wide-band gap layers disposed respectively over and beneath said channel layer, each of said upper and lower high-resistance wide-band gap layers having a silicon-doped planar layer disposed therein; said upper high-resistance wide-band gap layer including a low-resistance wide-band gap layer disposed in an upper end region thereof remotely from said channel layer, and wherein said low-resistance wide-band gap layer is doped with an impurity at a concentration ranging from 3×10 17 cm -3 to 1×10 18 cm -3 and has a thickness ranging from 40 Å to 120 Å.
Claim 3
Dependent Claim
23 words
A high electron mobility transistor according to claim 1, wherein said channel layer has a thickness ranging from 50 Å to 150 Å.
Claim 4
Dependent Claim
31 words
A high electron mobility transistor according to claim 1, wherein said upper and lower high-resistance wide-band gap layers are of a symmetrical structure with respect to said channel layer disposed therebetween.
Claim 5
Dependent Claim
22 words
A high electron mobility transistor according to claim 1, wherein said low-resistance-wide band gap layer has a thickness of approximately 80 Å.
Claim 6
Dependent Claim
28 words
A high electron mobility transistor according to claim 2 including a contact layer disposed on said low-resistance wide-band gap layer and has a thickness of approximately 500 Å.
References Cited (Backward Citations)
US33584A
Cited
USRE33584E
Cited
JPS61156542A
Cited
US4943438A
Cited
US5060030A
Cited
US5140386A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-05-03 | 2002-11-02 | 2003-05-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-05-03 | 2006-11-02 | 2007-05-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-05-03 | 2010-11-02 | 2011-05-04 | $7700.00 | Window Closed / Lapsed |