Patent ID: 8062931

Claim:
A method for making a group III-nitride field effect device comprising: placing a substrate in a reaction chamber; depositing a first active layer; depositing a second active layer having a higher bandgap when compared to said first active layer, thereby forming a two-dimensional electron gas layer at or near an interface between said first active layer and said second active layer; depositing on said second active layer a first passivation layer; depositing directly on said first passivation layer a source contact; depositing directly on said first passivation layer a drain contact; performing a first cleaning step on at least a first part of said first passivation layer, said first part of said first passivation layer being a gate cleaning region; forming a gate contact on at least part of said gate cleaning region after the first cleaning step; performing a second cleaning step on at least a second part of said first passivation layer, said at least second part of said first passivation layer being a passivation cleaning region; and depositing a second passivation layer on at least part of said passivation cleaning region after the second cleaning step.