# US 12,218,255 B2 · High voltage gallium nitride vertical PN diode

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 12,218,255 B2
- Document ID: US12218255B2
- Status: Granted
- Kind: B2
- Application number: 17/572,360
- Filed: 2022-01-10
- Published: 2022-05-26
- Granted: 2025-02-04
- Earliest claimed: 2018-10-09
- Assignees: National Technology & Engineering Solutions of Sandia, LLC
- Applicants: National Technology & Engineering Solutions of Sandia, LLC
- Inventors: Luke Yates; Brendan P. Gunning; Mary H. Crawford; Jeffrey Steinfeldt; Michael L. Smith; Vincent M. Abate; Jeramy R. Dickerson; Andrew M. Armstrong; Andrew Binder; Andrew A. Allerman; Robert J. Kaplar; Jack David Flicker; Gregory W. Pickrell
- Web page: https://patentgrep.com/patent/US12218255B2

## CPC

- H10D 8/411: {PN diodes having planar bodies}
- H10D 8/045: {of PN junction diodes}
- H10D 8/422: {PN diodes having the PN junctions in mesas}
- H10D 62/104: {having particular shapes of the bodies at or near reverse-biased junctions, e.g. having bevels or moats}
- H10D 62/85: being Group III-V materials, e.g. GaAs
- H10D 62/8503: {Nitride Group III-V materials, e.g. AlN or GaN}
- H10D 64/62: Electrodes ohmically coupled to a semiconductor
- H10D 62/126: {Top-view geometrical layouts of the regions or the junctions}
- H10P 14/24: using chemical vapour deposition [CVD]
- H10P 14/2908: {Nitrides}
- H10P 14/3216: {Nitrides}
- H10P 14/3248: {consisting of two layers}
- H10P 14/3416: {Nitrides}
- H10P 14/3444: {P-type}
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10

## Abstract

A vertical gallium nitride (GaN) PN diode uses epitaxial growth of a thick drift region with a very low carrier concentration and a carefully designed multi-zone junction termination extension to achieve high voltage blocking and high-power efficiency. An exemplary large area (1 mm2) diode had a forward pulsed current of 3.5 A, an 8.3 mΩ-cm2 specific on-resistance, and a 5.3 kV reverse breakdown. A smaller area diode (0.063 mm2) was capable of 6.4 kV breakdown with a specific on-resistance of 10.2 mΩ-cm2, when accounting for current spreading through the drift region at a 45° angle.

## Claims

### Claim 1

A high voltage gallium nitride vertical PN diode, comprising:
a high-doped n-type gallium nitride substrate or contact layer;
a low-doped n-type gallium nitride drift layer epitaxially grown on the gallium nitride substrate, wherein the drift layer is greater than 10 microns in thickness and has a donor concentration of less than 2×1015/cm3;
a p-type region comprising one or more p-type layers epitaxially grown on the drift layer, thereby forming a PN junction with the drift layer;
an ohmic cathode contact deposited on the high-doped n-type gallium nitride substrate or contact layer;
an ohmic anode contact deposited on the p-type region; and
a step-etched multi-zone junction termination extension structure laterally surrounding the anode contact in the p-type region.

### Claim 2 (depends on 1)

The high voltage gallium nitride vertical PN diode of claim 1, wherein the low-doped n-type gallium nitride drift layer is grown by metal-organic chemical vapor deposition under compensation doping conditions.

### Claim 3 (depends on 1)

The high voltage gallium nitride vertical PN diode of claim 1, wherein the drift layer is equal to or greater than 50 microns in thickness.

### Claim 4 (depends on 1)

The high voltage gallium nitride vertical PN diode of claim 1, wherein the area of the anode contact is greater than 0.01 mm2.

### Claim 5 (depends on 4)

The high voltage gallium nitride vertical PN diode of claim 4, wherein the area of the anode contact is greater than 0.1 mm2.

### Claim 6 (depends on 1)

The high voltage gallium nitride vertical PN diode of claim 1, wherein the p-type region comprises a moderately doped p-type gallium nitride layer epitaxially grown on the drift layer and a high-doped p-type gallium nitride layer epitaxially grown on the moderately doped p-type gallium nitride layer.

### Claim 7 (depends on 6)

The high voltage gallium nitride vertical PN diode of claim 6, wherein the moderately doped p-type gallium nitride layer has an acceptor concentration of less than 1019 cm−3.

### Claim 8 (depends on 6)

The high voltage gallium nitride vertical PN diode of claim 6, wherein the high-doped p-type gallium nitride layer has an acceptor concentration of greater than 1019 cm−3.

### Claim 9 (depends on 1)

The high voltage gallium nitride vertical PN diode of claim 1, wherein the step-etched multi-zone junction termination extension structure comprises two or more zones.

### Claim 10 (depends on 1)

The high voltage gallium nitride vertical PN diode of claim 1, wherein the PN diode has an avalanche breakdown voltage of greater than 5 kV in reverse bias.