Self-Aligned Four-Terminal P-Channel Cu-MIC Poly-Ge1-xSnxThin-Film Transistors on a Glass Substrate

We previously reported the fabrication of self-aligned planar double-gate p-channel (p-ch) polycrystalline germanium-tin (poly-Gel-xSnx) thin-film transistors (TFTs) via copper metal-induced crystallization at 500°C. To improve their performance, it is necessary to evaluate the controllability of the threshold voltages (Vth) for the top gate (TG) and bottom gate (BG), respectively. For this purpose, a four-terminal p-ch poly-Gel-xSnx TFT was fabricated and characterized. Our studies revealed that the values of Ύ, where y= Vth/VCG and VCG is the control gate voltage, for the TG and BG drives were nearly the same, thus, indicating the similar quality of the TG and BG stacks.