Effects of Plasma Treatments on the Characteristics of Poly-Si Thin-Film Transistors Having Electrical Junctions Induced by a Bottom Sub-Date

摘要

The effects of H_2 and NH_3 plasma on poly-Si thin-film transistors with source/drain extensions induced by a bottom sub-gate were investigated. Significant improvement in device characteristics could be made using the two methods, though the NH_3-plasma-treated devices show better performance than the H_2-plasma-treated counterparts in terms of lower off-state leakage, smaller subthreshold swing, and improved mobility, etc. Moreover, an anomalous subthreshold hump phenomenon observed in short-channel devices is also less significant for the devices treated by NH_3 plasma. Our analysis indicates that the NH_3 plasma is more effective in passivating the traps distributing in both front and back sides of the channel.