Physical/chemical characterization and device applications of transparent zinc-tin-oxide thin films deposited using RF sputtering

초록

Amorphous Zn-Sn-O (zinc-tin-oxide, ZTO) thin films were deposited with a mixed ZnO/SnO2 target through RF sputtering. The deposited Zn-Sn-O thin films were characterized using physical/chemical probing tools, such as optical characterization based on spectroscopic ellipsometry, surface morphology via atomic force microscopy, chemical information determined through X-ray photoelectron spectroscopy, and structural monitoring of crystallinity using X-ray diffraction. The ZTO thin-film transistors were constructed with a bottom-gate structure using thermally grown SiO2 as the gate dielectric. The Zn-Sn-O 11 TFTs were characterized in terms of the channel thickness, dielectric thickness, and annealing temperatures, and degradation tests were performed at higher temperatures than under ambient conditions. The Zn-Sn-O thin film transistors were optimized at a ZTO thickness of 40 am, a SiO2 gate dielectric thickness of 100 nm after annealing at 500 degrees C, and had an on/off ratio of 8.22 x 10(+7), a field-effect mobility of 12.90 cm(2)/V s, a threshold voltage of 4.32 V, and an S-slope of 0.69 V/decade. (C) 2014 Elsevier Ltd and Techna Group S.r.l. All rights reserved.

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