A STUDY OF ELECTRICALLY ACTIVE DEFECTS CREATED IN P-INP BY CH4-H-2 REACTIVE ION ETCHING

The electrical effects of reactive ion etching (RIE) of p-InP by CH4:H -2 are investigated. By using optical deep-level transient spectroscop y, several deep-level defects could be detected. The main defect (E3) is found to be a donor with an energy level at E-c - 0.38 eV. From dep th profiles of both the net acceptor concentration and this defect, it follows that after RIE, the E3 defects are passivated by hydrogen. Si multaneous passivation of both accepters and donors on p-InP is report ed. Subsequent rapid thermal annealing at increasing temperatures show s that the E3 defects are first depassivated and then annealed out. Th e change of the Schottky barrier height with the anneal temperature co uld be explained by Fermi-level pinning due to E3 and depinning either by its passivation for low enough temperatures or by its annealing ou t at higher temperatures. Some possibilities concerning the physical n ature of E3 are discussed. (C) 1997 American Institute of Physics.