High-temperature current conduction through three kinds of Schottky diodes

Fundamentals of the Schottky contacts and thehigh-temperature current conduction through three kinds of Schottkydiodes are studied. N-Si Schottky diodes, GaN Schottky diodes andAlGaN/GaN Schottky diodes are investigated by I--V--Tmeasurements ranging from 300 to 523~K. For these Schottky diodes, arise in temperature is accompanied with an increase in barrierheight and a reduction in ideality factor. Mechanisms aresuggested, including thermionic emission, field emission,trap-assisted tunnelling and so on. The most remarkable finding inthe present paper is that these three kinds of Schottky diodes arerevealed to have different behaviours of high-temperature reversecurrents. For the n-Si Schottky diode, a rise in temperature isaccompanied by an increase in reverse current. The reverse currentof the GaN Schottky diode decreases first and then increases withrising temperature. The AlGaN/GaN Schottky diode has a trendopposite to that of the GaN Schottky diode, and the dominantmechanisms are the effects of the piezoelectric polarization field andvariation of two-dimensional electron gas charge density.