Abstract: A tunneling transistor comprising an emitter layer, a barrier layer having a conduction band higher in energy than a conduction band of said emitter layer and a valence band lower in energy than a valence band of said emitter layer, and further having a thickness with which electrons can substantially tunnel the barrier layer, a collector layer having a conduction band lower in energy than the valence band of said emitter layer and a conductivity type opposite to said emitter layer, and further having a thickness with which quantum levels are substantially formed, a gate layer having a conduction band higher in energy than the conduction band of said layer and a valence band of said emitter layer, and further having a thickness with which the probability of electron tunneling is substantially greatly reduced, said layers been laminated in this order, and electrodes which form ohmic junctions on said emitter layer and said collector layer and an electrode which forms a Schottky junction on said gate layer.

Abstract: There is disclosed a heterojunction bipolar transistor (HBT) which operates as either the emitter top mode performance or the collector top mode performance and also operates for low power dissipation due to lower ON voltages. A high gain, ultra-high speed semiconductor device is also disposed which includes a collector top type pnp HBT as a switching transistor and a lateral npn bipolar transistor as a current injection source, together with an integration method thereof which meets high density requirement with simple processes. The HBT is implemented with an InP substrate and a collector or emitter layer of p type In.sub.x Al.sub.1-x As lattice matched at least to the InP substrate, a base layer of n type In.sub.x Ga.sub.1-x As, a first spacer layer interposed between the base and collector and a second spacer layer between the base and emitter, both the spacer layers being made of p type In.sub.x Ga.sub.

Abstract: The disclosed heterojunction bipolar transistor, to be referred to as the "coherent" transistor (CT), is capable of providing gain above the conventionally defined cut-off frequencies f.sub.T and f.sub.max. Substantially, mono-energetic (average energy .DELTA.) carriers are injected in beam-like fashion into the base, with kT<.DELTA.<hv.sub.opt, where k, T and h have their conventional meaning, and v.sub.opt is the frequency of the lowest relevant optical phonon in the base of width W.sub.B. Exemplarily, W.sub.B is about 100 nm, .DELTA. is about 20 meV, the CT comprises Si.sub.1-x Ge.sub.x or III/V material, with the base being doped n-type. The CT utilizes substantially collisionless minority carrier transport through the base, and is designed such that, at an operating temperature which typically is .ltorsim.77K, the variance of the average base transit time (.DELTA..tau..sub.B) is much less than the base transit time .tau..sub.B, typically less than 0.5 .tau..sub.B, preferably about .tau..sub.

Abstract: This invention relates to a semiconductor sensor for detecting external physical forces, such as acceleration, contact pressures, air pressures, mechanical vibrations, etc. The semiconductor sensor according to this invention is characterized by the use of compound semiconductors of high piezoelectricity, such as GaAs, etc. Conventionally sensors of the cantilever type, diaphragm type, etc. are made of silicon. These prior art sensors have low detection sensitivity, and their characteristics tend to deteriorate. The sensor according to this invention is made of GaAs, which has high piezoelectricity and can retain good characteristics of the semiconductor even at high temperatures and includes a field-effect transistor formed on the GaAs for sensing a stress. The FET is driven by a constant current or a constant voltage so as to detect a change of an electrical characteristic (e.g., threshold characteristic) due to a stress.

Abstract: A high-speed semiconductor device which comprises an emitter layer, a base layer, a collector layer, a potential barrier layer disposed between the emitter layer and the base layer, and a superlattice disposed between the base layer and the collector layer. The superlattice provides a multitude of quantum-mechanical transmission coefficients which can be applied to linear analog circuits and high frequency circuit. In addition, the high speed semiconductor device may act as a frequency multiplier, providing an output signal having 2n times as many frequencies as an input signal when n is the number of energy pass bands in said superlattice below a predetermined applied voltage.

Abstract: A transferred electron effect device has a semiconductor body with an active region (2) of n conductivity type formed of a semiconductor material having a relatively low mass, high mobility conduction band main minimum and at least one relatively high mass, low mobility conduction band satellite minimum, and an injection zone (3) adjoining the active region (2) for causing electrons to be emitted, under the influence of an applied electric field, from the injection zone (3) into the active region (2) with an energy comparable to that of the relatively high mass, low mobility, conduction band satellite minima of the active region.

Abstract: A solid state, quantum mechanical electron/hole wave device in the form of a switch or multiplexor includes a layer of semiconductor material supporting substantially ballistic electron/hole transport and a periodic grating structure formed in the layer of semiconductor material, with the grating structure comprising a modulation in electron/hole potential energy and/or effective mass. Preferably, means are provided for applying and varying the grating modulation. By constructing the device to divide the input substantially completely into two output beams (to operate in the Bragg regime), a useful switch is provided. Likewise, by constructing the device to divide the input into a selected number of three or more output beams (to operate in the Raman-Nath regime), a useful multiplexor is provided.

Abstract: A three-terminal hot-electron device, in particular a two dimensional electron gas base transistor which can be fabricated by molecular beam epitaxy (MBE). The two-dimensional electron gas is induced in an undoped GaAs quantum well by a modulation doping is used as the base of the transistor and permits a common-base current gain .alpha. to be achieved as high as 0.96 under a collector bias of 2.5 V and an emitter current of 3 mA.