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US 5,670,804 AGranted
PN-junction gate FET
AssigneeHitachi, Ltd.
InventorsToshiyuki Usagawa, Akemi Sawada, Kenichi Tominaga
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AssigneeHitachi, Ltd.
InventorsToshiyuki Usagawa, Akemi Sawada, Kenichi Tominaga
Estimating the term…
A semiconductor device is diclosed which has a PN-junction gate field effect transistor constituting a PN-junction gate with a semiconductor layer of opposite conductivity, an undoped semiconductor layer, and an active layer by depositing sources and drains made of semiconductor layers on the active layer of uniconductivity, depositing an undoped semiconductor layer whose band gap is greater than that of the active layer on the active layer between the opposing end surfaces of the sources and drains, and depositing a semiconductor layer of opposite conductivity on the undoped semiconductor layer away from the sources and drains. In particular, the present invention is effective for an enhancement type PN-junction power FET using compound semiconductors such as GaAs and capable of running with a single power supply and for a semi-conductor device integrating the enhancement type PN-junction power FET and a high-frequency low noise amplifier mono-lithically.
A semiconductor device having an active layer of a first conductivity type, a source and a drain of a field effect transistor made of semiconductor layers formed directly on said active layer, an undoped semiconductor layer whose band gap is greater than that of said active layer which is formed on the active layer between opposing end surfaces of said source and said drain, and a semiconductor layer of conductivity opposite to the first conductivity type which is formed on said undoped semiconductor layer apart from said source and said drain, wherein said opposite-conductivity semiconductor layer, said undoped semiconductor layer, and said active layer constitute a PN-junction gate of said field effect transistor, and the semiconductor device has source, drain, and gate electrodes which are respectively electrically connected to said source, said drain, and said gate.
A semiconductor device having an active layer of a first conductivity type, a source and a drain of a field effect transistor made of semiconductor layers formed directly on said active layer, an undoped semiconductor layer whose band gap is greater than that of said active layer which is formed on the active layer between opposing end surfaces of said source and said drain, and a semiconductor layer of conductivity opposite to the first conductivity type which is formed on said undoped semiconductor layer apart from said source and said drain, wherein said opposite-conductivity semiconductor layer, said undoped semiconductor layer, and said active layer constitute a PN-junction gate of said field effect transistor, said source and drain are made of a same material as that of said active layer, and the semiconductor device has source, drain, and gate electrodes which are respectively electrically connected to said source, said drain, and said gate.
Dependencies are inferred from the claim text.