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US 6,274,893 B1Granted
Compound semiconductor device and method of manufacturing the same
AssigneeFujitsu Quantum Devices Limited
InventorsTsutomu Igarashi, Kenji Arimochi, Teruo Yokoyama, Eizo Mitani, Shigeru Kuroda, Junichiro Nikaido, Yasunori Tateno
Life of this patent
Estimating the term…
Abstract
The impurity concentration contained in a layer on an electron supply layer of a high electron mobility field effect transistor is set in the range of 1×1016 to 1×1017 atoms/cm3, or the bandgap of a Schottky layer is set wider than that of the electron supply layer.
Claims18
A compound semiconductor device comprising:
- a channel layer formed on a compound semiconductor substrate, and formed of material which has a first donor concentration and a first bandgap;
- a carrier supply layer formed on the channel layer, and formed of material which has a second donor concentration being higher than the first donor concentration and a second bandgap being wider than the first bandgap;
- a first compound semiconductor layer formed on the carrier supply layer, and containing donors in at least one of a lower layer portion and an upper layer portion within a range of impurity concentration of 1×1016 to 1×1017 atoms/cm3;
- a gate electrode connected to the first compound semiconductor layer;
- a cap layer formed on the first compound semiconductor layer in a source region and a drain region which are formed on both sides of the gate electrode, and formed of material which has a third donor concentration being higher than the first donor concentration and a third bandgap being narrower than the second bandgap;
- a source electrode at least a part of which is formed on the cap layer in the source region;
- and
- a drain electrode at least a part of which is formed on the cap layer in the drain region.
5 more elements
A compound semiconductor device comprising:
- a channel layer formed on a compound semiconductor substrate, and formed of material which has a first donor concentration and a first bandgap;
- a carrier supply layer formed on the channel layer, and formed of material which has a second donor concentration being higher than the first donor concentration and a second bandgap being wider than the first bandgap;
- a Schottky layer formed on the carrier supply layer, and formed of material which has a third bandgap being wider than the second bandgap;
- a gate electrode connected to the Schottky layer;
- a buried layer having a recess in which a part of the gate electrode is buried;
- a cap layer formed on the Schottky layer in a source region and a drain region which are formed on both sides of the gate electrode, and formed of material which has a third donor concentration being higher than the first donor concentration and a fourth bandgap being narrower than the second bandgap;
- a source electrode at least a part of which is formed on the cap layer in the source region;
- and
- a drain electrode at least a part of which is formed on the cap layer in the drain region.
6 more elements
A compound semiconductor device comprising:
- a channel layer formed on a semiconductor substrate;
- a carrier supply layer formed on the channel layer;
- a Schottky semiconductor layer formed on the carrier supply layer and having a gate connection region;
- a gallium-arsenide buried layer formed on the Schottky semiconductor layer;
- a gallium-arsenide cap layer formed on the gallium-arsenide buried layer;
- a first recess formed in the gallium-arsenide cap layer to expose a pair of the gallium-arsenide buried layer, and having a width which is wider than the gate connection region;
- a second recess formed in the gallium-arsenide buried layer to expose the gate connection region of the Schottky semiconductor layer;
- a silicon nitride film provided in the first recess to extend from an end surface of the second recess onto the gallium-arsenide buried layer and the gallium-arsenide cap layer;
- a gate electrode connected to the Schottky semiconductor layer in the second recess;
- and
- a source electrode and a drain electrode formed on the gallium-arsenide cap layer respectively.
8 more elements
Dependencies are inferred from the claim text.