Radiation induced interface states in metal-aluminosilicate (Al2O3⋅SiO2) insulator-Si capacitors

Abstract

Aluminosilicate (Al2O3⋅SiO2) thin films were prepared on a (100) Si wafer by pyrolysis of Al(CH3)3, SiH4, and N2O gases at the deposition temperature of 850 °C. From the high-frequency and the quasi-static capacitance-voltage measurements, the initial interface state densities of capacitors with Al2O3⋅SiO2 gate insulators were 1.3–2.2×1011 cm−2 eV−1, and hysteresis characteristics were not present. Distribution of interface states of Al2O3⋅SiO2/Si was different from that of SiO2/Si. Even after exposure to 1×105 rads (Si) of Co60 γ-ray irradiation, the interface states were not affected. The interface state density showed a slight increase after exposure to 1×106 rads.