Low-Temperature-Processed SiInZnO Thin-Film Transistor Fabricated by Radio Frequency Magnetron Sputtering
High-performance oxide semiconductor thin-film transistors (TFTs) have been fabricated with 1 wt% silicon-doped indium zinc oxide (1SIZO). The channel layer of the 1SIZO TFTs was deposited by radio frequency sputtering at room temperature. To investigate the effect of annealing on the electrical and structural properties of the TFTs, the annealing temperature was varied between 100 and 500 °C. As the annealing temperature increases from 100 to 300 °C, the crystal structure of the 1SIZO film showed an amorphous phase. However, for the 1SIZO film annealed at 500 °C, the structure of 1SIZO clearly showed a transition from amorphous to polycrystalline. The transfer curve was negative shifted as the annealing temperature increased. Further, at the annealing temperature of 400 °C, the 1SIZO TFT became conductive and the off current disappears. This can be attributed to the increase in carrier concentration due to the high annealing temperatures. The electrical properties of optimized 1SIZO TFTs, such as a field-effect mobility (μFE) of 13.05 cm2/V s, an on/off current ratio (ION/OFF) of 4.94 × 108, and a subthreshold swing of 0.37 V/decade have been obtained for high performance at the low annealing temperature of 100 °C.
KeywordsThin-film transistor Annealing temperature Oxide semiconductor SiInZnO X-ray diffraction