Patent ID: 7071499
Filing Date: 2006-07-04
Classification: H01L

Abstract:
1. A heterojunction field effect type semiconductor device, comprising: a GaAs substrate; a channel layer formed over said GaAs substrate; a first semiconductor layer including no aluminum formed over said channel layer; a cap layer of a first conductivity type formed on said first semiconductor layer, said cap layer creating a first recess on said first semiconductor layer; first and second ohmic electrodes formed on said cap layer; a second semiconductor layer of a second conductivity type formed on said first semiconductor layer within said first recess, said second semiconductor layer being isolated from said cap layer; a gate electrode formed on said second semiconductor layer; and a third semiconductor layer made of GaAs/AlGaAs interposed between said first semiconductor layer, wherein said third semiconductor layer comprises an GaAs layer formed on an AlGaAs layer, and said cap layer and having a second recess, said second semiconductor layer passing through the second recess of said third semiconductor layer to reach said first semiconductor layer.