Numerical simulation of sidegating effect in GaAs MESFET's

Two-dimensional simulation of the sidegating effect in GaAs MESFETs has been performed. The result confirms that Schottky contacts on a semi-insulating substrate cause serious high substrate leakage current and drain current reduction in GaAs MESFETs. The threshold behavior in the sidegating effect is found to correlate with the conduction behavior of the Schottky-i-n (sidegate) structure when the sidegate is negatively biased. Shielding and enhancement of the sidegating effect by the Schottky contacts have also been studied, and the results agree with the experimental findings. Besides, the presence of hole traps in the semi-insulating substrate is found to be essential to the sidegating effect.>