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US 5,635,735 AGranted
Field effect transistor with an improved Schottky gate structure
AssigneeNEC Corporation
InventorsHironobu Miyamoto, Kazuhiko Onda
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Abstract
The invention provides a Schottky barrier structure comprising a Schottky gate electrode, a first layer in contact with said Schottky gate electrode and said first layer being made of a first compound semiconductor and a second layer in contact with said first layer and said second layer being made of a second compound semiconductor having a higher conduction band edge than a conduction band edge of said first compound semiconductor.
Claims48
A Schottky barrier structure comprising:
- a Schottky gate electrode;
- a first layer in contact with said Schottky gate electrode, said first layer being made of a first compound semiconductor which is undoped, and said first layer having a thickness in the range of 5-10 nanometers;
- a second layer in contact with said first layer, said second layer being made of a second compound semiconductor which is undoped and which has a higher conduction band edge than a conduction band edge of said first compound semiconductor;
- a third layer in contact with said second layer, said third layer being made of a third compound semiconductor which is undoped and which has a smaller conduction band edge than a conduction band edge of said second compound semiconductor, said third layer having a thickness of not less than 20 nanometers;
- and
- a fourth layer in contact with said third layer, said fourth layer being made of a fourth compound semiconductor which is doped with an impurity.
3 more elements
A Schottky gate field effect transistor comprising:
- a semiconductor substrate;
- a first layer formed on said semiconductor substrate and said first layer being made of a first compound semiconductor;
- a second layer formed on said first layer and said second layer being made of a second compound semiconductor having a higher conduction band edge than a conduction band edge of said first compound semiconductor, said second layer being undoped and having a thickness of not less than 20 nanometers;
- a third layer formed on said second layer and said third layer including at least one electron barrier layer made of a third compound semiconductor having a higher conduction band edge than said conduction band edge of said second compound semiconductor, said third layer being undoped and having a thickness in the range of 5-10 nanometers;
- a fourth layer formed on said third layer and said fourth layer being made of a fourth compound semiconductor having a lower conduction band edge than said conduction band edge of said third compound semiconductor;
- source and drain regions separated through a recess portion from one another and formed on said fourth layer and said source and drain regions being made of a fifth compound semiconductor having a lower conduction band edge than said conduction band edge of said fourth compound semiconductor;
- source and drain electrodes provided on said source and drain regions;
- and
- a Schottky gate electrode provided on an exposed surface of said fourth layer in said recess portion.
6 more elements
Dependencies are inferred from the claim text.