Electrical modifications of InP samples induced by reactive ion etching (RIE) with CH4/H-2 have been studied using (a) electrochemical capacitance-voltage measurements, (b) current-voltage characteristics of Schottky diode structures, and jc) transient reflected microwave conductivity measurements. From the capacitance-voltage measurements we confirm a depletion of holes near the surface of the dry-etched p-InP sample and an accumulation of electrons near the surface of the dry-etched n-InP sample. The hole concentration in p-InP sample can be recovered after a 400 degreesC, 1 min heat treatment in an Ar ambient. From the transient reflected microwave conductivity measurements we reveal new information on the modification of charge carrier mobilities and kinetics caused by dry etching and subsequent annealing procedures on p-InP, n-InP, and semi-insulating (Fe-doped) InP samples. The n-InP sample shows a loss in electron mobility after RIE and annealing; the p-InP sample shows a weakly n-type behavior after RIE and recovers the p-type behavior after annealing.