US5360983A
Expired / Lapsed
US
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Insulated gate bipolar transistor having a specific buffer layer resistance
Assignee: Fuji Electric Co Ltd
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Filing: 1993-04-16
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Granted: 1994-11-01
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Expires: 2013-04-16
Abstract
Abstract An n + buffer layer, that is located between an n - base layer and a p + substrate, has a resistivity in the range of 0.005-0.03 Ωcm and a thickness not more than 10μm. Further, the base layer has an impurity concentration not more than (0.3×I 1 )/(S×1.6×10 -19 ×6.0×10 6 ), where I 1 is a rated current in ampere and S is an effective are in cm 2 .
Inventors
- 👤 Noriyuki Iwamuro
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 16:15
CPC Classifications
H; H10; H10D; H10D62/00; H10D62/10; H10D62/13; H10D62/141; H10D62/142; H10D12/00; H10D12/411; H10D12/441
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
180 words
An insulated gate bipolar transistor comprising in a semiconductor base: a first region of a first conduction type; a second region of a second conduction type formed on the first region; a third region of the second conduction type formed on the second region and having a low impurity concentration; a fourth region of the first conduction type selectively formed in a surface layer of the third region; and a fifth region of the second conduction type selectively formed in a surface layer of the fourth region and having a high impurity concentration; said insulated gate bipolar transistor further comprising: a gate electrode formed, via a gate insulating film, on a surface portion of the fourth region which portion is interposed between the third and fifth regions and serves as a channel region; a source electrode being commonly in contact with the fourth and fifth regions; and a drain electrode being in contact with the first region; wherein the second region has a resistivity in a range of 0.005 to 0.03 Ωcm and a thickness not more than 10 μm.
Claim 2
Dependent Claim
180 words
An insulated gate bipolar transistor comprising in a semiconductor base: a first region of a first conduction type; a second region of a second conduction type formed on the first region; a third region of the second conduction type formed on the second region and having a low impurity concentration; a fourth region of the first conduction type selectively formed in a surface layer of the third region; and a fifth region of the second conduction type selectively formed in a surface layer of the fourth region and having a high impurity concentration; said insulated gate bipolar transistor further comprising: a gate electrode formed, via a gate insulating film, on a surface portion of the fourth region which portion is interposed between the third and fifth regions and serves as a channel region; a source electrode being commonly in contact with the fourth and fifth regions; and a drain electrode being in contact with the first region; wherein the second region has a resistivity in a range of 0.005 to 0.03 Ωcm and a thickness not more than 10 μm.
Claim 3
Dependent Claim
39 words
The insulated gate bipolar transistor of claim 1, wherein the impurity concentration of the third region is not more than 30% of a concentration of minority carriers flowing through a depletion layer of the third region at a turn-off.
Claim 4
Dependent Claim
49 words
The insulated gate bipolar transistor of claim 2, wherein the impurity concentration of the third region is not more than (0.3×I 1 )/(S×1.6×10 -19 ×6.0×10 6 ), where I 1 is a rated current in ampere and S is an effective area in cm 2 of the semiconductor base.
References Cited (Backward Citations)
US5124772A
Cited
US5237183A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-10-31 | 1998-05-02 | 1998-11-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-10-31 | 2002-05-02 | 2002-11-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-10-31 | 2006-05-02 | 2006-11-01 | $7700.00 | Window Closed / Lapsed |