US 5,345,100 AGranted

Semiconductor rectifier having high breakdown voltage and high speed operation

AssigneeShindengen Electric Manufacturing Co., Ltd.

InventorsTakashi Kan, Masaru Wakatabe, Mitsugu Tanaka, Shinji Kunori, Akira Sugiyama

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Abstract

A semiconductor rectifier having a high breakdown voltage and a high speed operation is provided, which comprises a semiconductor substrate including a first semiconductor layer of one conductivity type and a second semiconductor layer of one conductivity type provided on the first semiconductor layer, a third semiconductor layer of an opposite conductivity type having a depth D and formed in the second semiconductor layer to provide a pn junction therebetween, the third semiconductor layer defining a plurality of exposed regions of the second semiconductor layer, each of the plurality of exposed regions of the second semiconductor layer having a width W, a relation between the depth D and the width W being given by D.gtoreq.0.5W, and a metal electrode provided on the substrate surface.

Claims19

Dependent claims

A semiconductor rectifier comprising:

a first semiconductor layer of a first conductivity type having a main surface;
a second semiconductor layer of a second conductivity type formed in said first semiconductor layer to define a plurality of portions of said first semiconductor layer exposed to said main surface, each of said plurality of portions of said first semiconductor layer being surrounded by opposed portions of said second semiconductor layer and forming a p-n junction with each of said opposed portions of said second semiconductor layer below said main surface;
a metal electrode provided over a surface of said second semiconductor layer including said plurality of portions of said first semiconductor layer, said metal electrode forming a contact surface with each of said plurality of portions of said first semiconductor layer;
and
a relation between a depth D and a width W being given by D>0.5W where said depth D is a distance between said contact surface and a bottom of said second semiconductor layer, and said width W being a shortest distance between said opposed portions of said second semiconductor layer below said contact surface.

2 more elements

A semiconductor rectifier comprising:

a first semiconductor layer of a first conductivity type;
a plurality of grooves formed in said first semiconductor layer to provide projected portions;
a second semiconductor layer of a second conductivity type formed in said first semiconductor layer, except for an exposed surface of each of said projected portions, to define opposed portions of said second semiconductor layer on opposing sides of each of said projected portions, each of said opposed portions of said second semiconductor layer forming a p-n junction with said first semiconductor layer, wherein a depth D of said second semiconductor layer is a distance between said exposed surface of each of said projected portions and a bottom of said p-n junction, and a distance W is a shortest distance between said opposed portions of said second semiconductor layer below said exposed surface of each of said projected portions;
a relation between said depth D and said distance W being given by D>0.5W;
an angle .theta. being given by 60.degree.<.theta.<90 .degree., where said angle .theta. is an angle between said exposed surface of each of said projected portions and a tangent line passing through a point f on said p-n junction, said point f being at an intersection of said p-n junction and a straight line passing through a top of a built-in depletion layer and extending in parallel with said exposed surface of each of said projected portions;
and
a metal electrode provided over a surface of said second semiconductor layer including said exposed surface of said projected portions.

4 more elements

Dependencies are inferred from the claim text.