Reactively ion etched (RIE) n-GaN epitaxial films with different degrees of surface damage are investigated. To realize prominent effects resulting from RIE damage on electrical and optical properties, the samples are processed at various rf power levels and particularly under relatively high dc self-bias. We find that the restoration of crystal damage in optical properties evaluated by photoluminescence (PL) peak enhancements for samples thermally annealed at 750°C for 3 min could achieve up to 60 to 65% of those before RIE processing. Under high dc self-bias, it is evident that higher rf power produces rougher etched surfaces with more severe damage and higher surface resistance, so the damaged crystal is more difficult to recover. A transmission-line model is used to estimate the variation of ohmic contact resistance. Note that KOH surface treatment prior to contact deposition is more effective in lowering contact resistance than that of a damaged surface restored only by rapid thermal annealing (RTA) processing.