Growth temperature influence on nanocrystalline ZnO thin film FET performance

Abstract

Nanocrystalline ZnO (nc-ZnO) thin film transistors (TFT) are being developed for applications that require much higher performance than TFTs available from other all thin film technologies. Because of their unique closely packed nanocolumnar structures, uniform quality nc-ZnO films can be fabricated over large non-conformal surfaces. Excellent performance characteristics were demonstrated with devices fabricated on GaAs1 and Si2 substrates. Devices with 2µm gate lengths had field effect mobilities in excess of 100 cm2/V.s, drain current on/off ratios of better than 1012, transconductance of 80mS/mm and current densities higher than 400mA/mm. High frequency cut-off frequency values of fT=2.45GHz and fmax=7.45GHz were demonstrated with 1.2µm gate length devices.