Electrical Characteristics of Liquid-Phase-Deposited Titanium Oxide Films on (NH[sub 4])[sub 2]S[sub x]-Treated InP Substrate

Abstract

The electrical characteristics of liquid-phase-deposited titanium oxide films on ammonium-sulfide-treated p-type InP(100) substrate were investigated. The aqueous solutions of hexafluorotitanic acid and boric acid were used as the starting materials. For InP substrate without ammonium sulfide treatment, the electrical characteristics of titanium oxide films are poor. For InP substrate with ammonium sulfide treatment, the electrical characteristics are much improved. The leakage currents can reach 2× 10-7 and 7× 10-7 A cm2 under positive and negative electric fields at 0.5 MVcm. The dielectric constant and the effective oxide charges are 40 and -2× 1011 C cm2, respectively. The interface state density is 8× 1011 cm-2 eV-1 at the energy of 0.78 eV from the edge of valence band.