We studied I-V curves of Au-TiB x-n-n +-GaAs and Au-TiB x-n-SiC 6Í surface-barrier structures. The structures were exposed to microwave treatments (frequency of 2.45 GHZ, irradiance of 1.5 W/cm 2 , duration of 0500 s). For these structures we measured how the Schottky barrier height and ideality factor depended on microwave treatment duration. It was shown that microwave treatments whose duration are up to 20 s do not impair the main structure parameters, while those with duration of 0.510 s may even improve these parameters.