High Voltage Gallium Nitride Vertical PN Diode

Patent metadata

Field	Value
Publication number	US-2022165888-A1
Application number	US-202217572360-A
Country	US
Kind code	A1
Filing date	Jan 10, 2022
Priority date	Oct 9, 2018
Publication date	May 26, 2022
Grant date	—

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.

First claim

We 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 2×10 15 /cm 3 ; 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 to the high-doped n-type gallium nitride substrate or contact layer; an ohmic anode contact to the p-type region; and a step-etched multi-zone junction termination extension structure laterally surrounding the anode contact in the p-type region.

2 . 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.

3 . 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.

4 . The high voltage gallium nitride vertical PN diode of claim 1 , wherein the area of the anode contract is greater than 0.01 mm 2 .

5 . The high voltage gallium nitride vertical PN diode of claim 1 , wherein the area of the anode contract is greater than 0.1 mm 2 .

6 . 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.

7 . 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 10 19 cm −3 .

8 . 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 10 19 cm −3 .

9 . 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.

10 . 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.

Assignees

• Nat Tech & Eng Solutions Sandia Llc

Inventors

• Yates Luke
• Gunning Brendan P
• Crawford Mary H
• Steinfeldt Jeffrey
• Smith Michael L
• Abate Vincent M
• Dickerson Jeramy R
• Armstrong Andrew M
• Binder Andrew
• Allerman Andrew A
• Kaplar Robert J
• Flicker Jack David
• Pickrell Gregory W

Classifications

• H10P14/24

  using chemical vapour deposition [CVD] · CPC title

• H10P14/3444

  P-type · CPC title

• H10P14/3416

  Nitrides · CPC title

• H10P14/3248

  consisting of two layers · CPC title

• H10P14/3216

  Nitrides · CPC title