Passivation of group III-nitride heterojunction devices
Passivation of group III-nitride heterojunction devices is described herein. The passivation facilitates simultaneous realization of effective/high current collapse suppression and low leakage current without the use of a sophisticated multiple-field plate technique. The passivation can be achieved by growing a charge-polarized AlN thin film on the surface of a group III-nitride based heterojunction device by plasma-enhanced atomic layer deposition such that positive polarization charges are induced at the interface to compensate for a majority of negative charges at the interface.
1. An apparatus, comprising:
a group III-nitride heterojunction device; and
a charge-polarized aluminum nitride (AlN) film on the surface of the group III-nitride heterojunction device,
wherein the interface between the group III-nitride heterojunction device and the charge-polarized AlN film comprises a density of positive polarization charges on an order of at least about 10 13 cm −2 .
2. The apparatus of claim 1 , wherein the charge-polarized AlN film has a thickness of about 10 nm or less.
3. The apparatus of claim 1 , wherein the charge-polarized AlN film comprises a single-crystalline arrangement or a polycrystalline atomic arrangement.
4. The apparatus of claim 1 , wherein the density of positive polarization charges is greater than the density of negative charges at the interface from the group III-nitride heterojunction device.
5. The apparatus of claim 1 , further comprising a stacked passivation structure comprising the AlN film and a second dielectric material.