Study of GSZO TFTs for Fabrication on Plastic Substrates.

摘要

Flexible electronics have many developing applications, such as liquid crystal displays (LCDs), organic lightemitting diodes (OLEDs), flex- circuits with connectors and flexible solar cells. Transparent amorphous oxide semiconductors (TAOSs) are the likely candidates to form the active layer of the pixel-driven thin film transistors (TFTs) due to their good uniformity, excellent electrical and optical properties, and compatibility with low temperature deposition. The excellent properties of indium gallium zinc oxide (IGZO) make it the prime candidate; however, the increase in demand of indium has driven up the price. Hence, cheaper substitutes for indium which can produce TAOS TFTs suitable for plastic substrates with comparable characteristics are desired. The focus of this work is on the investigation of the effect of radio frequency (RF) sputtered deposition parameters on the gallium tin zinc oxide (GSZO) based thin film transistor performance and stability. The compositional, optical and morphological properties of the films were examined using x-ray spectroscopy, x-ray reflectivity, Rutherford backscattering and optical absorption techniques. The TFTs were characterized using room temperature current - voltage and capacitance-voltage characteristics and their optical and electrical stability were examined. It was found that that the TFT performance for the GSZO channel deposition and annealing temperature below 140 deg C are sensitive to the deposition parameters.