Heterojunction field effect type semiconductor device having high gate turn-on voltage and low on-resistance and its manufacturing method
AssigneeNEC Electronics Corporation
InventorYasunori Bito
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Abstract
In a heterojunction field effect type semiconductor device, a channel layer is formed over a GaAs substrate, and a first semiconductor layer including no aluminum is formed over the channel layer. First and second cap layers of a first conductivity type are formed on the first semiconductor layer, to create a recess on the first semiconductor layer. First and second ohmic electrodes are formed on the first and second cap layers, respectively. A second semiconductor layer of a second conductivity type is formed on the first semiconductor layer within the recess, and the semiconductor layer is isolated from the first and second cap layers. A gate electrode is formed on the second semiconductor layer.
Claims16
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.
Dependencies are inferred from the claim text.