Complementary inverter circuits based on p-SnO(2) and n-In(2)O(3) thin film transistors

Abstract

Thin film transistors (TFTs) of indium oxide (In(2)O(3)) and tin oxide (SnO(2)) were fabricated on SiO(2) gate dielectric using reactive evaporation process. Structural investigation of the films revealed that In(2)O(3) films were polycrystalline in nature with preferred (222) orientation and SnO(2) films exhibited amorphous nature. The x-ray photoelectric spectroscopy measurements suggest that SnO(2) films were oxygen rich and presume mixed oxidation states of Sn, namely Sn(2+) and Sn(4+). While the In(2)O(3) based TFTs possess n-type channel conduction, SnO(2) based TFTs exhibited anomalous p-type conductivity. Integration of these n- and p-type devices resulted in complementary inverter with a gain of 11. (C) 2008 American Institute of Physics.