Patent US4752818A successfully refreshed from Google Patents.
US4752818A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Semiconductor device with multiple recombination center layers
Assignee: Toyota Central R&D Labs Inc
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Filing: 1986-09-26
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Granted: 1988-06-21
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Expires: 2006-09-26
Abstract
Abstract A semiconductor device comprises two main electrode regions, i.e., cathode and anode regions consisting of high impurity concentration regions of opposite conductivity types, a low impurity concentration region locally formed between the two main electrode regions, a gate region, formed near the cathode region, for controlling a main current, a first local region which has a relatively low carrier lifetime and is formed in a region of the low impurity concentration region near at least one of the gate and cathode regions, and a second local region which has a relatively low carrier lifetime and is formed in a region of the low impurity concentration region which is depleted at the end of the main current turn-off process or which is not depleted to the end, thus satisfying three conditions, i.e., high-speed switching, low forward voltage drop, and high blocking voltage between the main electrodes at the same time.
Inventors
- 👤 Tomoyoshi Kushida
- 👤 Hiroshi Tadano
- 👤 Yoshio Nakamura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:09
CPC Classifications
H; H10; H10P; H10P34/00; H10P34/40; H10D; H10D12/00; H10D12/211; H10D12/212; H10D18/00; H10D18/60; H10D18/65; H10D18/655; H10D62/00; H10D62/50; H10D62/53
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
166 words
A static induction thyristor comprising: a cathode region consisting of a high impurity concentration region; an anode region consisting of a high impurity concentration region of an opposite conductivity type than that of said cathode region; said anode and cathode regions being spaced from one another; a low impurity concentration region locally formed between said cathode and anode regions; a gate region, formed near said cathode region, for controlling flow of a main current; a first local region having a relatively low carrier lifetime and formed in said low impurity concentration region near at least one of said gate and cathode regions, said first local region being formed as a layer extending substantially perpendicular to the flow of the main current; and a second local region having a relatively low carrier lifetime and formed in a region of said low impurity concentration region near said anode region, said second local region being formed as a layer extending substantially perpendicular to the flow of the main current.
Claim 2
Dependent Claim
166 words
A static induction thyristor comprising: a cathode region consisting of a high impurity concentration region; an anode region consisting of a high impurity concentration region of an opposite conductivity type than that of said cathode region; said anode and cathode regions being spaced from one another; a low impurity concentration region locally formed between said cathode and anode regions; a gate region, formed near said cathode region, for controlling flow of a main current; a first local region having a relatively low carrier lifetime and formed in said low impurity concentration region near at least one of said gate and cathode regions, said first local region being formed as a layer extending substantially perpendicular to the flow of the main current; and a second local region having a relatively low carrier lifetime and formed in a region of said low impurity concentration region near said anode region, said second local region being formed as a layer extending substantially perpendicular to the flow of the main current.
Claim 3
Dependent Claim
39 words
A static induction thyristor according to claim 1, comprising a region of the same conductivity type as that of said cathode region locally formed in said anode region and at the same potential as that of said anode region.
Claim 4
Dependent Claim
54 words
A static induction thyristor according to claim 1, comprising a third local region formed between said first and second local regions so that the distance between said local regions of relativley low carrier lifetime does not exceed the distance of diffusion in said low impurity concentration region of carriers injected by said cathode region.
Claim 5
Dependent Claim
24 words
A static induction thyristor according to claim 3, comprising a second gate region formed near said anode region for controlling the flow of current.
Claim 6
Dependent Claim
39 words
A static induction thyristor according to claim 3, comprising a region of the same conductivity type as that of said cathode region locally formed in said anode region and at the same potential as that of said anode region.
Claim 7
Dependent Claim
181 words
A static induction thyristor comprising: a cathode region consisting of a high impurity concentration region; an anode region consisting of a high impurity concentration region of an opposite conductivity type to that of said cathode region, said anode region having a front surface facing said cathode region; a thin layer region formed on said front surface of said anode region and having a relatively impurity concentration; a low impurity concentration region locally formed between said cathode region and said thin layer region; a gate region, formed near said cathode region, for controlling flow of a main current; a first local region having a relatively low carrier lifetime and formed in said low impurity concentration region near at least one of said gate and cathode regions, said first local region being formed as a layer extending substantially perpendicular to the flow of the main current; and a second local region having a relatively low carrier lifetime and formed in said thin layer region, said second local region being formed as a layer extending substantially perpendicular to the flow of the main current.
Claim 8
Dependent Claim
181 words
A static induction thyristor comprising: a cathode region consisting of a high impurity concentration region; an anode region consisting of a high impurity concentration region of an opposite conductivity type to that of said cathode region, said anode region having a front surface facing said cathode region; a thin layer region formed on said front surface of said anode region and having a relatively impurity concentration; a low impurity concentration region locally formed between said cathode region and said thin layer region; a gate region, formed near said cathode region, for controlling flow of a main current; a first local region having a relatively low carrier lifetime and formed in said low impurity concentration region near at least one of said gate and cathode regions, said first local region being formed as a layer extending substantially perpendicular to the flow of the main current; and a second local region having a relatively low carrier lifetime and formed in said thin layer region, said second local region being formed as a layer extending substantially perpendicular to the flow of the main current.
Claim 9
Dependent Claim
54 words
A static induction thyristor according to claim 6, comprising a third local region formed between said first and second local regions so that the distance between said local regions of relatively low carrier lifetime does not exceed the distance of diffusion in said low impurity concentration region of carriers injected by said cathode region.
Claim 10
Dependent Claim
39 words
A static induction thyristor according to claim 7, comprising a region of the same conductivity type as that of said cathode region locally formed in said anode region and at the same potential as that of said anode region.
Claim 11
Dependent Claim
25 words
A static induction thyristor according to claim 7, comprising a second gate region formed near said anode region for controlling the flow of main current.
Claim 12
Dependent Claim
39 words
A static induction thyristor according to claim 6, comprising a region of the same conductivity type as that of said cathode region locally formed in said anode region and at the same potential as that of said anode region.
Claim 13
Dependent Claim
25 words
A static induction thyristor according to claim 6, comprising a second gate region formed near said anode region for controlling the flow of main current.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-06-21 | 1991-12-21 | 1992-06-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-06-21 | 1995-12-21 | 1996-06-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-06-21 | 1999-12-21 | 2000-06-21 | $7700.00 | Window Closed / Lapsed |