Low Temperature Modeling of Ni/β-Ga₂O₃ Schottky Barrier Diode Interface

Abstract

Schottky barrier diodes (SBD) are usually qualified by their figures of merit. Evolution of these figures of merit with temperature is an indication of the different conduction mechanisms involved in SBD. Figures of merit extraction at different temperatures is therefore of great importance. Thermionic emission conduction modeling of I–V characteristics is usually considered when extracting these figures of merit. However, high-ideality factor values are obtained at low temperatures because of other conduction mechanisms involved. In this work, TCAD simulation is used to model measured Ni/β-Ga2 O3 SBDs at a temperature range of 100–300 K. This modeling separates tunneling current from thermionic emission current; hence, a reasonable ideality factor of 6.04 was obtained from the total current. An ideality factor of about 1.04 was extracted from the thermionic current component only. Evolution with temperature of this combination of tunneling and thermionic emission is examined. It is concluded that, with increasing temperature, tunneling is reduced while thermionic emission is increased; thus, an ideality factor is almost independent of temperature and close to unity is obtained.