Schottky contact effects in the sidegating effect of GaAs devices

The sidegating effect measurements on ungated FETs verify that the Schottky contact on undoped substrates causes serious current reduction in GaAs devices and high leakage current in the semi-insulating GaAs. By realizing the fact that current in Schottky-i-n structures can be high and taking this effect into account, the observed abrupt changes and S-shaped characteristics of the drain and sidegate currents can be explained to be the consequence of the transition of the substrate current from the n-i-n current to the Schottky-i-n current.>