EP0103138A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Semiconductor rectifier diode
Assignee: Hitachi Ltd
•
Filing: 1983-08-03
•
Granted: —
•
Expires: 2003-08-03
Abstract
Abstract in accordance with the present invention, there is provided a semiconductor rectifier diode which has low loss, quick response and soft reverse recovery properties and is composed of three consecutive layers, i.e., a p-type emitter layer (3), an n-type base layer (4) and an n-type emitter layer (5), the p-type emitter layer being composed of a first portion (31) and second portions (32) which surround said first portion, have a higher impurity concentration as compared with said first portion, and extend beyond said first portion toward said n-type base layer, and said base layer being composed of a first layer portion (41) which is adjacent to said n-type emitter layer and a second layer portion (42) which is located near a p-n junction (J,) side and has a lower impurity concentration as compared with said first layer portion.
Inventors
- 👤 Masayoshi Naito
- 👤 Yoshiteru Shimizu
- 👤 Yoshio Terasawa
- 👤 Susumu Murakami
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 16:26
CPC Classifications
H; H10; H10D; H10D8/00; H10D62/00; H10D62/10; H10D62/124; H10D62/125; H10D62/60
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
292 words
A semiconductor rectifier diode composed of a semiconductor substrate (100) having a pair of main surfaces (101, 102) thereon and a pair of main electrodes (1,2) provided on both of said main surfaces of said semiconductor substrate, said semiconductor rectifier diode comprising: said semiconductor substrate including a first emitter layer (3) of a first conductivity type which is adjacent to one (101) of said main surfaces and in contact with one (1) of said main electrodes, a base layer (4) of a second conductivity type being adjacent to said first emitter layer and forming a p-n junction (J 1 ) between said first emitter layer and said base layer, and a second emitter (5) of the second conductivity type being adjacent to said base layer and to the other one (102) of said main surface and being in contact with the other one (2) of said main electrodes; and said first emitter layer including a first portion (31) and second portions (32) which together surround said first portion on said one main surface, extend further than said first portion in a direction perpendicular to said one main surface, and have a higher impurity concentration as compared with said first portion, a width (W ch ) of said first portion of said first emitter layer, when viewed in a direction parallel to said main surfaces, having a sufficient value so that said base layer are pinched off at a portion thereof lying under said first portion and between said second portions of said first emitter layer by a depletion layer produced when the p-n junction is reverse-biased with the rated voltage of said diode, and the impurity concentration in said base layer being increased with increase in the distance from said p-n junction.
Claim 2
Dependent Claim
292 words
A semiconductor rectifier diode composed of a semiconductor substrate (100) having a pair of main surfaces (101, 102) thereon and a pair of main electrodes (1,2) provided on both of said main surfaces of said semiconductor substrate, said semiconductor rectifier diode comprising: said semiconductor substrate including a first emitter layer (3) of a first conductivity type which is adjacent to one (101) of said main surfaces and in contact with one (1) of said main electrodes, a base layer (4) of a second conductivity type being adjacent to said first emitter layer and forming a p-n junction (J 1 ) between said first emitter layer and said base layer, and a second emitter (5) of the second conductivity type being adjacent to said base layer and to the other one (102) of said main surface and being in contact with the other one (2) of said main electrodes; and said first emitter layer including a first portion (31) and second portions (32) which together surround said first portion on said one main surface, extend further than said first portion in a direction perpendicular to said one main surface, and have a higher impurity concentration as compared with said first portion, a width (W ch ) of said first portion of said first emitter layer, when viewed in a direction parallel to said main surfaces, having a sufficient value so that said base layer are pinched off at a portion thereof lying under said first portion and between said second portions of said first emitter layer by a depletion layer produced when the p-n junction is reverse-biased with the rated voltage of said diode, and the impurity concentration in said base layer being increased with increase in the distance from said p-n junction.
Claim 3
Dependent Claim
52 words
A semiconductor rectifier diode according to Claim 1, wherein said base layer comprises a first layer portion (41) which is adjacent to said second emitter layer and a second layer portion (42) which is adjacent to said p-n junction and has a lower impurity concentration as compared with said first layer portion.
Claim 4
Dependent Claim
55 words
A semiconductor rectifier diode according to Claim 2, wherein the impurity concentration in said first layer portion of said base layer is lower than the carrier concentration in the forward conductive state of the device and is sufficient to prevent the depletion layer from widening beyond said first layer portion under the reverse blocking state.
Claim 5
Dependent Claim
29 words
A semiconductor rectifier diode according to Claim 2, wherein said first portion of said first emitter layer is composed of a plurality of regions formed in a stripe form.
Claim 6
Dependent Claim
35 words
A semiconductor rectifier diode according to Claim 1, wherein said base layer is composed of a single region in which the impurity concentration is continuously increased with increase in the distance from said p-n junction.
Claim 7
Dependent Claim
59 words
A semiconductor rectifier diode according to Claim 5, wherein the impurity concentration in a portion of said base layer which is located near said second emitter layer is lower than the carrier concentration in the forward conductive state of the device and is sufficient to prevent said depletion layer from widening beyond said portion under the reverse blocking state.
Claim 8
Dependent Claim
29 words
A semiconductor rectifier diode according to Claim 5, wherein said first portion of said first emitter layer is composed of a plurality of regions arranged in a stripe form.
Claim 9
Dependent Claim
53 words
A semiconductor rectifier diode according to Claim 2, wherein a third layer portion (43) of the other conductivity type having an impurity concentration which is lower than that in said first layer portion of said base layer is put between said first layer portion of said base layer and said second emitter layer.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.