Analysis of I-V characteristics on Au/n-type GaAs Schottky structures in wide temperature range

The current-voltage (I-V) characteristics of Au/n-GaAs Schottky barrier diodes (SBD) were determined in the temperature range 80-400 K. SBD parameters such as ideality factor n, series resistance RS and barrier height Φb were extracted from I-V curves using Cheung's method. The barrier height for current transport decreases and the ideality factor increases with the decrease temperatures. Such behavior is attributed to barrier inhomogeneities by assuming a Gaussian distribution of barrier heights at the interface. So that barrier height ΦI-V have been corrected by taking into account quality factors (n) and the electron tunneling factor (αχ1/2δ) in the expression of saturation current (I0) of the Au/n-GaAs Schottky diodes. Thus, a modified ln(I0/T2)−q2σ02/2k2T2 versus 1/T gives Φ¯b0(T=0) and A* as 0.73 eV and 11.08 A/(cm2 K2), respectively, without using the temperature coefficient of the barrier heights. Therefore, it has been concluded that the temperature dependent I-V characteristics of the device can be successfully explained with Gaussian distribution of the BHs.