Process-Induced Defects in InP Caused by Chemical Vapor Deposition of Surface Passivation Dielectrics

Abstract
Near-surface defects of InP produced during three different chemical vapor deposition (CVD) processes were systematically characterized by capacitance-voltage ( C-V ) and deep level transient spectroscopy (DLTS) techniques. Deposition of plasma-enhanced CVD (PECVD) phosphosilicate glass (PSG) and SiO2 films produced the same bulk level, lying at 0.35 eV below the conduction band edge, near the surface region of InP. Such a level was absent in the samples prepared by the photo CVD process. In addition, the photo CVD process gave a lower density of interface states than the PECVD process. The origin of the bulk trap and the energy- and space-distributed nature of interface states are discussed.