Electrical Characteristics of Stacked Titanium Oxide/Aluminum Oxide by Atomic Layer Deposition on (NH₄)₂ S-Treated Gaas

The (NH 4 ) 2 S treatment was used for the reduction of native oxides and passivation on GaAs. Atomic layer deposited Al 2 O 3 can further remove the residue native oxides and lower the leakage current on (NH4)2S treated GaAs from self-cleaning and high bandgap. For further stacked with high dielectric constant TiO 2 also prepared by atomic layer deposition on Al2O3/(NH4)2S treated p-type GaAs MOS capacitor, the leakage currents can reach 1.9 × 10 -8 and 3.1 × 10 -6 A/cm2 at ± 2 MV/cm. The dielectric constant is 25.