Termination and contact structures for a high voltage GaN-based heterojunction transistor
View Patent ↗A semiconductor device is provided that includes a substrate, a first active layer disposed over the substrate, and a second active layer disposed on the first active layer. The second active layer has a higher bandgap than the first active layer such that a two-dimensional electron gas layer arises between the first active layer and the second active layer. A termination layer, which is disposed on the second active layer, includes InGaN. Source, gate and drain contacts are disposed on the termination layer.
1. A semiconductor device, comprising:
a substrate;
a first active layer disposed over the substrate;
a second active layer disposed on the first active layer, the second active layer having a higher bandgap than the first active layer such that a two-dimensional electron gas layer arises between the first active layer and the second active layer, wherein the second active layer includes first and second recesses formed therein;
a source and drain contact disposed in the first and second recesses, respectively;
a gate electrode disposed over the second active layer; and
a termination layer disposed over the second active layer and wherein the source and drain contacts extend through the termination layer.
2. The semiconductor device according to claim 1 wherein the termination layer comprises InGaN.
3. The semiconductor device according to claim 1 wherein the termination layer is selected from the group consisting of Fe-doped GaN, Si-doped GaN, FeN and SiN.
4. The semiconductor device according to claim 1 , wherein the first active layer comprises a group III nitride semiconductor material.
5. The semiconductor device according claim 4 , wherein the first active layer comprises GaN.
6. The semiconductor device according to claim 1 , wherein the termination layer comprises a flash layer.
7. The semiconductor device according to claim 6 , wherein the flash layer comprises Al.
8. The semiconductor device according to claim 6 , wherein the flash layer comprises Ga.
9. The semiconductor device according to claim 6 , wherein the flash layer comprises In.