Gallium nitride electromagnetic pulse arrestor
A GaN diode EMP arrestor exhibits breakdown in <10 ns at reverse-bias voltage >20 kV. Additionally, the arrestor exhibits avalanche ruggedness at 1 kA/cm 2 in a 1 mm 2 device (i.e. 10 A absolute current) over a period of 500 ns following the onset of breakdown. Finally, the specific on-resistance in the forward direction is <20 mΩ cm 2 .
1. An electromagnetic pulse arrestor, 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 thickness of the low-doped n-type gallium nitride drift layer is greater than 100 μm, wherein the low-doped n-type gallium nitride drift layer is grown by metal-organic chemical vapor deposition;
a high-doped p-type gallium nitride layer epitaxially grown on the drift layer, thereby forming a p-n junction with the drift layer;
an edge termination structure laterally surrounding the p-n junction on the drift layer;
an ohmic cathode contact to the high-doped n-type gallium nitride substrate or contact layer;
and an ohmic anode contact to the high-doped p-type gallium nitride layer.
2. The electromagnetic pulse arrestor of claim 1 , wherein the substrate is grown by hydride vapor-phase epitaxy or ammonothermal bulk growth.
3. The electromagnetic pulse arrestor of claim 1 , wherein the low-doped n-type gallium nitride drift layer has a donor density of less than 2×10 15 cm −3 .
4. The electromagnetic pulse arrestor of claim 3 , wherein the donor density of less than 2×10 15 cm −3 is achieved by growth under compensation doping conditions.
5. The electromagnetic pulse arrestor of claim 1 , wherein the high-doped p-type gallium nitride layer has an acceptor density of greater than 10 19 cm −3 .
6. The electromagnetic pulse arrestor of claim 1 , wherein the electromagnetic pulse arrestor has an avalanche breakdown voltage of greater than 20 kV in reverse bias.
7. The electromagnetic pulse arrestor of claim 1 , wherein the electromagnetic pulse arrestor has a response time of less than 10 ns.
8. The electromagnetic pulse arrestor of claim 1 , wherein the electromagnetic pulse arrestor is electrically connected in parallel with a grid equipment to be protected, such that the voltage experienced by the grid equipment during an electromagnetic pulse event is clamped at an avalanche breakdown voltage of the electromagnetic pulse arrestor.