Characteristics of bottom-gate low temperature nanocrystalline silicon thin film transistor fabricated by hydrogen annealing of gate dielectric layer

摘要

Thin film transistors having nanocrystalline silicon as an active layer were fabricated by catalytic-CVD at a low process temperature (≤200 ℃). The tri-layer of the bottom-gate TFT was deposited continuously inside the Cat-CVD reactor. In order to improve the quality of the gate dielectric layer an in-situ hydrogen annealing step was introduced in between the silicon nitride and the nanocrystalline silicon deposition steps. The in-situ hydrogen annealing was effective in reducing the hysteresis in the C-V characteristics and in enhancing the breakdown voltage by decreasing the defects inside the SiN_x film.