Low Interface State Density of Liquid-Phase-Deposited SiO[sub 2] Films on (NH[sub 4])[sub 2]S[sub x]-Treated InP

Abstract

The electrical characteristics, including current-voltage, capacitance-voltage, hysteresis loops, and interface state density, of liquid-phase-deposited (LPD)-SiO2grown on p-type (100) indium phosphide substrates with and without(NH4)2Sxtreatments were investigated. The aqueous solution of hydrofluosilicic acid and boric acid were used as the growth solution for silicon dioxide films. The indium phosphide with ammonium sulfide treatment improves the electrical characteristics. The electrical characteristics depend on the boric acid concentration in the growth solution. The leakage currents can reach 6.24 and8.14×10−8A∕cm2under positive and negative electric fields at0.5MV∕cm. The effective oxide charges are−5.33×1010C∕cm2. The interface state density is9.65×1010cm−2eV−1at the energy of0.67eVfrom the valance band.