Spacistor

The Spacistor is a transistor version, based similar to the bipolar transistor at a potential effect. It was developed in the 1950s with the aim of improving the electrical properties compared to the point-contact transistor and the former alloy transistors. With the invention and improvement of the diffusion transistors in the late 1950s, this advantage was meaningless.

Design and operation

Spacistor of a semiconductor device with four electrodes. It consists of a pn-junction with a wide space charge region ( depletion layer ). The p-type region of the PN junction is referred to as the base and n-type region as a collector. In the space charge region, two additional contacts are present: the injector ( injector ) and the modulator (modulator ).

Comparing the function of the connections with those of a bipolar transistor ( BJT), the following analogies arise:

The basic idea of ​​Spacistor was to use the strong tension gradient in a blocked pn junction. By the injection of charge carriers in the barrier layer, the transit times of the charge carriers in the transistor should be reduced, thus increasing the switching frequency. The injector current is controlled by the modulator.