# US 5,710,445 A · Gate turn-off thyristor for high blocking voltage and small component thickness

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- Number: US 5,710,445 A
- Document ID: US5710445A
- Status: Granted
- Kind: A
- Application number: 08/495,080
- Filed: 1995-06-27
- Granted: 1998-01-20
- Earliest claimed: 1994-09-02
- Assignees: Asea Brown Boveri AG
- Inventors: Friedhelm Bauer; Simon Eicher
- Web page: https://patentgrep.com/patent/US5710445A

## CPC

- H10D 18/60: Gate-turn-off devices
- H10D 62/142: {Anode regions of thyristors or collector regions of gated bipolar-mode devices}
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES

## Abstract

A GTO is specified which, starting from the anode-side main surface (2), comprises an anode emitter (6), a barrier layer (11), an n-base (7), a p-base (8) and a cathode emitter (9). The anode emitter (6) is designed as a transparent emitter and has anode short-circuits (10). By virtue of the combination of the barrier layer, the transparent anode emitter and the anode short-circuits, a GTO is obtained which can be operated at high switching frequencies, the substrate thickness of which can be reduced and which nevertheless exhibits no increase in the switching losses.

## Claims

### Claim 1

A gate turn-off thyristor, comprising:
a) between a first main surface and a second main surface, a number of differently doped semiconductor layers;
b) on the second main surface, an anode electrode and, on the first main surface, a cathode electrode and a gate electrode;
c) the semiconductor layers comprising, viewed from the second main surface, a p.sup.+ -doped anode emitter, an n-doped n-base and a p-doped p-base, the anode emitter being in electrical contact with the anode electrode and the p-base being in electrical contact with the gate electrode, and n.sup.+ -doped cathode-emitter regions, which are in electrical contact with the cathode electrode, being incorporated in the p-base;
wherein
d) the anode emitter is designed as a transparent emitter;
e) n.sup.+ -doped anode short-circuit regions penetrate through the anode emitter, and
f) an n-doped barrier layer is provided between the n-base and the anode emitter, said barrier layer being epitaxially produced and having at least a two-stage doping profile, including a first stage, further away from the second main surface, being more heavily doped, and a second stage, directly adjoining the second main surface, being more lightly doped relative to the first stage.

### Claim 2 (depends on 1)

The thyristor as claimed in claim 1, wherein the barrier layer is diffused and, in particular, has a depth of approximately 20 .mu.m to 40 .mu.m and an edge concentration of approximately 7*10.sup.14 cm.sup.-3.

### Claim 3 (depends on 2)

The thyristor as claimed in claim 2, wherein the transparent emitter has a depth of approximately 1.2 .mu.m and a doping level of approximately 10.sup.18 cm.sup.-3.

### Claim 4 (depends on 2)

The thyristor as claimed in claim 2, wherein the anode short-circuit regions have a small diameter of, in particular, 5 .mu.m to 10 .mu.m.

### Claim 5 (depends on 1)

The thyristor as claimed in claim 1, wherein the barrier layer is epitaxially produced and, in particular, has a depth of approximately 20 .mu.m to 40 .mu.m.

### Claim 6 (depends on 5)

The thyristor as claimed in claim 5, wherein the said first stage of said barrier layer has a doping level of approximately 10.sup.15 cm.sup.-3 and a depth of approximately 10 .mu.m, and said second stage of said barrier layer has a doping level of less than approximately 10.sup.14 cm.sup.-3 and a depth of approximately 10 .mu.m.

### Claim 7 (depends on 6)

The thyristor as claimed in claim 6, wherein the transparent emitter has a depth of approximately 1.2 .mu.m and a doping level of approximately 10.sup.18 cm.sup.-3.

### Claim 8 (depends on 6)

The thyristor as claimed in claim 6, wherein the anode short-circuit regions have a small diameter of, in particular, 5 .mu.m to 10 .mu.m.

### Claim 9 (depends on 5)

The thyristor as claimed in claim 5, wherein the transparent emitter has a depth of approximately 1.2 .mu.m and a doping level of approximately 10.sup.18 cm.sup.-3.

### Claim 10 (depends on 5)

The thyristor as claimed in claim 5, wherein the anode short-circuit regions have a small diameter of, in particular, 5 .mu.m to 10 .mu.m.

### Claim 11 (depends on 1)

The thyristor as claimed in claim 1, wherein the transparent emitter has a depth of approximately 1.2 .mu.m and a doping level of approximately 10.sup.18 cm.sup.-3.

### Claim 12 (depends on 11)

The thyristor as claimed in claim 11, wherein the anode short-circuit regions have a small diameter of, in particular, 5 .mu.m to 10 .mu.m.

### Claim 13 (depends on 1)

The thyristor as claimed in claim 1, wherein the anode short-circuit regions have a small diameter of, in particular, 5 .mu.m to 10 .mu.m.