Electrical characteristics of high performance spc and milc p-channel ltps-tft with high- κ gate dielectric

In this article, high performance p-channel, low temperature polysilicon thin-film transistors (LTPS-TFTs) are fabricated by using Hf O₂ gate dielectric and two crystallization methods, solid phase crystallization (SPC) and metal-induced lateral crystallization (MILC) are compared. High field-effect mobility (μ_FE ∼114 and 215 cm₂ /V s), ultralow subthreshold swing (SS ∼145 and 107 mV /decade), and low threshold voltage (V_th ∼-1.05 and -0.75 V) are derived from SPC- and MILC-TFTs with Hf O₂ gate dielectric, respectively. These excellent electrical characteristics are due to low trap states and much higher gate capacitance density with equivalent oxide thickness ∼12.3 nm, resulting in lower operation voltage within 2 V of LTPS-TFT without any passivation method. The comparison of SPC and MILC p-channel LTPS-TFTs with Hf O₂ gate dielectric is demonstrated.