An analysis of majority-carrier three-layer bulk semiconductor unipolar diodes

Abstract

Bulk unipolar diodes are majority-carrier three-layer (n-p-n) semiconductor diodes in which the current flows due to the thermionic emission of majority carriers over a barrier formed in the bulk of the material. Expressions for the barrier height of two typical bulk unipolar diodes, namely a bulk barrier diode (n++p+n) and a p-plane barrier diode (n+p++n), are derived. The functional dependence of the barrier height on various technological parameters is discussed. The two diodes are quite similar in their structure and characteristics. However, the p-plane barrier diode is more suitable as a majority-carrier diode. The variation of ideality factor and the saturation current of these diodes is shown to be very similar to the metal semiconductor diode.