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US 4,903,090 AGranted
Semiconductor device
AssigneeFujitsu Limited
InventorNaoki Yokoyama
Life of this patent
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Abstract
A permeable base transistor includes a conductive type emitter layer; a conductive type base layer provided on the emitter layer, the emitter layer having a wider energy bandgap than the base layer; a conductive type collector layer; comb-shaped or lattice-shaped base electrodes formed adjacent to a heterojunction surface formed by the emitter layer and the base layer, the electrodes are provided through a Schottky junction or an insulating layer to the surrounding emitter, base, and collector layers.
Claims10
A semiconductor device comprising:
- an emitter layer having a first conductivity type and a first energy band gap and a second energy band gap greater than the first energy band gap;
- a base layer having a predetermined conductivity type, provided on the emitter layer, and having a third energy band gap less than said first band gap of the emitter layer defining a heterojunction surface between the emitter layer and the base layer so that there is a discontinuity between conduction band edges of the emitter layer and the base layer so as to form an energy barrier therebetween so that hot electrons can be injected into said base layer from said emitter layer;
- one of comb-shaped and lattice-shaped base electrodes, formed adjacent to the heterojunction surface;
- and
- a collector layer having the first conductivity type, provided on the base layer.
2 more elements
A semiconductor device comprising:
- a first emitter layer having a first conductivity type and comprising a first compound semiconductor;
- ax second emitter layer having first and second surfaces, the first surface formed on the first emitter layer and having the first conductivity type, the second emitter layer comprising a second compound semiconductor and having a first energy band gap at the first surface and a second energy band gap at the second surface being larger than the first energy band gap;
- a base layer formed on the second surface of said second emitter layer having the first conductivity type, a band gap less than the first band gap so that hot electrons can be injected into said base layer from said second emitter layer and comprising the first compound semiconductor;
- electrodes comprising one of comb-shaped and lattice-shaped electrodes, formed in the base layer;
- and
- a collector layer formed on the base layer, having the first conductivity type and comprising the first compound semiconductor.
3 more elements
Dependencies are inferred from the claim text.