The Spacistor, A New Class of High-Frequency Semiconductor Devices

New devices are considered in which electrons or holes are injected directly into space-charge regions of reversebiased junctions avoiding the diffusion of carriers through field-free regions. The case considered is one in which the junction is biased at a voltage such that the injected carriers are multiplied by the avalanche process. A device of this type shall be called a spacistor. It is shown that negative resistance devices and amplifying devices may be constructed. The difficulty is the accumulation of the generated carriers in front of the emitting contact. Experimentally, it has been found that this accumulation of carriers results in the spontaneous relaxation-type oscillations of a transistor-like structure operated at collector voltages greater than the punch-through voltage. It is suggested that the accumulation effect may be diminished by the use of small emitters and magnetic fields.