Field effect transistor
OwnerTomohiro Murata, Hidetoshi Ishidainventors
Life of this patent
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Abstract
A field effect transistor includes a first semiconductor layer made of a first group III-V nitride; a second semiconductor layer formed on the first semiconductor layer, made of a second group III-V nitride and having a gate recess portion for exposing the first semiconductor layer therein; and a gate electrode formed on the first semiconductor layer in the gate recess portion. A product of stress applied by the second semiconductor layer to the first semiconductor layer and the thickness of the second semiconductor layer is 0.1 N/cm or less.
Claims12
A field effect transistor comprising:
- a first semiconductor layer made of a first group III-V nitride;
- a second semiconductor layer formed on said first semiconductor layer, made of a second group III-V nitride and having a gate recess portion;
- a gate electrode formed on said first semiconductor layer in said gate recess portion;
- and
- ohmic electrodes formed on said second semiconductor layer on both sides of said gate electrode,
- wherein a product of stress applied by said second semiconductor layer to said first semiconductor layer and a thickness of said second semiconductor layer is 0.1 N/cm or less at a gate recess side end of said second semiconductor layer.
A field effect transistor comprising:
- a first semiconductor layer made of a first group III-V nitride;
- a second semiconductor layer formed on said first semiconductor layer, made of a second group III-V nitride and having a gate recess portion;
- a gate electrode formed on said first semiconductor layer in said gate recess portion;
- and
- ohmic electrodes formed on said second semiconductor layer on both sides of said gate electrode,
- wherein a thickness of said second semiconductor layer is reduced toward a gate recess side end thereof in such a manner that thickness change becomes smaller toward the gate recess side end.
A field effect transistor comprising:
- a first semiconductor layer made of a first group III-V nitride;
- a second semiconductor layer formed above said first semiconductor layer, made of a second group III-V nitride and having a gate recess portion;
- a third semiconductor layer that is formed between said second semiconductor layer and said first semiconductor layer, is made of a third group III-V nitride and absorbs stress caused between said second semiconductor layer and said first semiconductor layer;
- a gate electrode formed on said first semiconductor layer in said gate recess portion;
- and
- ohmic electrodes formed on said second semiconductor layer on both sides of said gate electrode.
A field effect transistor comprising:
- a first semiconductor layer made of a first group III-V nitride;
- a second semiconductor layer formed on said first semiconductor layer, made of a second group III-V nitride and having a gate recess portion;
- a gate electrode formed on said first semiconductor layer in said gate recess portion;
- ohmic electrodes formed on said second semiconductor layer on both sides of said gate electrode;
- and
- a stress reducing film for covering a bottom and a sidewall of said gate recess portion and causing stress in a direction for cancelling stress applied by said second semiconductor layer to said first semiconductor layer.
Dependencies are inferred from the claim text.