Metal-induced crystallization of amorphous zinc tin oxide semiconductors for high mobility thin-film transistors

Abstract

Transition tantalum induced crystallization of amorphous zinc tin oxide (a-ZTO) was observed at low temperature annealing of 300 degrees C. Thin-film transistors (TFTs) with an a-ZTO channel layer exhibited a reasonable field-effect mobility of 12.4 cm(2)/Vs, subthreshold swing (SS) of 0.39V/decade, threshold voltage (V-TH) of 1.5 V, and I-ON/OFF ratio of similar to 10(7). A significant improvement in the field-effect mobility (up to similar to 33.5 cm(2)/V s) was achieved for crystallized ZTO TFTs: this improvement was accomplished without compromising the SS, V-TH, or I-ON/OFF ratio due to the presence of a highly ordered microstructure.