Analysis of InP Schottky/tunnel metal-insulator-semiconductor diode characteristics with a conductance technique

The current-voltage characteristics (I-V) of Au-n-type InP Schottky diodes and MIS Schottky diodes fabricated by multipolar plasma oxidation are measured at various temperatures in order to investigate the applicability of a newly proposed conductance technique. Experimental data are analysed on the basis of this technique relating the series resistance R s and the ideality factor n to the conductance G=dI/dV, and leading also to the determination of the saturation current I s . The values obtained for the temperature coefficient of the Schottky barrier height alpha were -1.3*10 -4 eV K -1 and 4.1*10 -4 eV K -1 , depending on the substrate, and the ideality factors were around 1.07. The Richardson plot ln(I s /T 2 ) against (1/T) is well fitted to a straight line (T is the temperature). It is shown that, when some conditions discussed in the paper are fulfilled; the method can be applied to MIS Schottky diodes. In this case the apparent barrier height phi Bh increases linearly with increasing temperature and the electron tunnelling factor is estimated to be 16.