US 2016/0111489 A1 · SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE

Abstract

A p anode layer is formed on one main surface of an n− drift layer. N+ cathode layer having an impurity concentration more than that of the n− drift layer is formed on the other main surface. An anode electrode is formed on the surface of the p anode layer. A cathode electrode is formed on the surface of the n+ cathode layer. N-type broad buffer region having a net doping concentration more than the bulk impurity concentration of a wafer and less than the n+ cathode layer and p anode layer is formed in the n− drift layer. Resistivity ρ0 of the n− drift layer satisfies 0.12V0≦ρ0≦0.25V0 with respect to rated voltage V0. Total amount of net doping concentration of the broad buffer region is equal to or more than 4.8×1011 atoms/cm2 and equal to or less than 1.0×1012 atoms/cm2.

Claims32

Dependent claims

1-15. (canceled)

A semiconductor device comprising:

a drift layer of a first-conductivity-type;
an anode layer of second-conductivity-type that is provided on a first main surface of the first semiconductor layer and has an impurity concentration more than that of the first semiconductor layer;
a cathode layer of the first-conductivity-type that is provided on a second main surface of the first semiconductor layer and has an impurity concentration more than that of the first semiconductor layer;
and
a plurality of broad buffer layers of the first conductivity-type that are provided in the first semiconductor layer and each of the broad buffer layers has an impurity concentration more than that of the first semiconductor layer, and has a mountain-shaped impurity concentration distribution in which a local maximum value is less than the impurity concentration of the second semiconductor layer and the cathode semiconductor layer, the mountain-shaped impurity concentration distribution having a peak at the local maximum value and differences of elevation in a depth direction,
wherein the plurality of broad buffer layers are disposed at different depths from the other main surface, respectively, and the number of broad buffer layers close to the second main surface from the intermediate position of the drift layer is more than the number of broad buffer layers close to the first main surface from the intermediate position of the drift layer.

3 more elements

A semiconductor device comprising:

a drift layer of a first conductivity-type;
a base layer of a second conductivity-type that is provided on a first main surface of the drift layer and has an impurity concentration more than that of the drift layer;
an emitter layer of the first-conductivity-type that is provided the first main surface of the drift layer in contact with the base layer and has an impurity concentration more than that of the base layer;
an insulation layer that is provided in contact with the drift layer, the base layer and the emitter layer;
a gate electrode that is adjacent to the drift layer, the base layer and the emitter layer through the insulation layer;
a collector layer of the second conductivity-type that is provided on a second main surface of the drift layer and has an impurity concentration more than that of the drift layer;
and
a plurality of broad buffer layers of the first conductivity-type that are provided in the drift layer and have an impurity concentration more than that of the drift layer, and have a mountain-shaped impurity concentration distribution in which a local maximum value is less than the impurity concentration of the base layer and the collector layer, the mountain-shaped impurity concentration distribution having a peak at the local maximum value and differences of elevation in a depth direction,
wherein the plurality of broad buffer layers are disposed at different depths from the other main surface, respectively, and the number of broad buffer layers close to the second main surface from the intermediate position of the drift layer is more than the number of broad buffer layers close to the first main surface from the intermediate position of the drift layer.

6 more elements

A semiconductor device comprising:

a drift layer of a first-conductivity-type;
an anode layer of second-conductivity-type that is provided on a first main surface of the first semiconductor layer and has an impurity concentration more than that of the first semiconductor layer;
a cathode layer of the first-conductivity-type that is provided on a second main surface of the first semiconductor layer and has an impurity concentration more than that of the first semiconductor layer;
and
a plurality of broad buffer layers of the first conductivity-type that are provided in the first semiconductor layer and each of the broad buffer layers has an impurity concentration more than that of the first semiconductor layer, and has a mountain-shaped impurity concentration distribution in which a local maximum value is less than the impurity concentration of the second semiconductor layer and the cathode semiconductor layer, the mountain-shaped impurity concentration distribution having a peak at the local maximum value and differences of elevation in a depth direction,
wherein the plurality of broad buffer layers are disposed at different depths from the other main surface, respectively, and the sum of the integrated concentrations of the plurality of broad buffer layers is equal to or more than 4.8×1011 atoms/cm2.

3 more elements

A semiconductor device comprising:

a drift layer of a first conductivity-type;
a base layer of a second conductivity-type that is provided on a first main surface of the drift layer and has an impurity concentration more than that of the drift layer;
an emitter layer of the first-conductivity-type that is provided the first main surface of the drift layer in contact with the base layer and has an impurity concentration more than that of the base layer;
an insulation layer that is provided in contact with the drift layer, the base layer and the emitter layer;
a gate electrode that is adjacent to the drift layer, the base layer and the emitter layer through the insulation layer;
a collector layer of the second conductivity-type that is provided on a second main surface of the drift layer and has an impurity concentration more than that of the drift layer;
and
a plurality of broad buffer layers of the first conductivity-type that are provided in the drift layer and have an impurity concentration more than that of the drift layer, and have a mountain-shaped impurity concentration distribution in which a local maximum value is less than the impurity concentration of the base layer and the collector layer, the mountain-shaped impurity concentration distribution having a peak at the local maximum value and differences of elevation in a depth direction,
wherein the plurality of broad buffer layers are disposed at different depths from the other main surface, respectively, and the sum of the integrated concentrations of the plurality of broad buffer layers is equal to or more than 4.8×1011 atoms/cm2.

6 more elements

Dependencies are inferred from the claim text.

Facts

Application

14/980,433Filed 28 Dec 2015

Priority

JP 2009-2519442 Nov 2009

Published

21 Apr 2016

Term ends

Not estimatedThe source records don’t support an estimate.

Classification21 codes

H10D 62/103
Constructional design considerations for preventing surface leakage or controlling electric field concentration: for increasing or controlling the…
H10D 8/00
Diodes
H10D 8/50
Diodes: pIN diodes
H10D 8/75
Tunnel-effect diodes: tunnel-effect PN diodes, e.g. Esaki diodes

Family

Application13/505,294Continuation · filed 9 Jul 2012

Application14/283,578Continuation · filed 21 May 2014

Application14/730,940Continuation · filed 4 Jun 2015

Application14/980,433Continuation

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