Nec Corporation

Nippon Electric Co., Ltd.

Jun'ichi Sone

Tooru Kimura

Shuichi Tahara

Masafumi Kawanaka

A heterostructure bipolar transistor is formed by a process of steps of holding an N-type gallium arsenide body using as an emitter region in a high vacuum of 10.sup.-9 torr to 10.sup.-13 torr at a first temperature of 400.degree. C. to 1,000.degree. C. where arsenic on a surface of the gallium arsenide body drifts away, lowering the first temperature to a second temperature of 300.degree. C. to 400.degree. C. to start a molecular beam epitaxial growth of a germanium, and forming an N-type germanium layer using as a collector region.

Method for manufacturing a heterostructure transistor having a germanium

The heterojunction bipolar transistor has a structure of wide band-gap transistor and comprises a collector region having an N-type GaAs layer, a base region having a P-type germanium layer formed on the N-type GaAs layer, and an emitter region having an N-type semiconductor layer of mixed crystal of silicon and germanium formed on the P-type germanium layer. The mixed crystal of the N-type semiconductor layer may have a uniform distribution of silicon or a graded distribution of silicon in which a content of silicon is zero at the surface facing the P-type germanium layer and is continuously increased with distance from the surface facing the P-type germanium layer.

Heterojunction bipolar transistor having a base region of germanium

A Josephson pulse generator of the current injection type is composed of a first group of N (N.gtoreq.2) resistors, one end of each being connected together, the other ends of two of the N resistors being connected to first and second nodes. A second group of serially connected N-1 resistors is connected between the first and second nodes and to the other ends of the N-2 resistors in the first group not connected to the first and second nodes. N Josephson junctions are each connected between a reference potential and the other end of a different one of the N resistors. Two additional Josephson junctions, each having one end thereof connected, respectively, to the first node and the second node is provided along with an additional resistor connected between the other end of the Josephson junction connected to the first node and the reference potential.

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Tokyo, Japan

Jun'ichi Sone