Performance of flexible In0.7Ga0.3As MOSFETs by utilizing liquid polyimide (LPI) transfer with effective mobility of 3,667 cm2/V-s

In this paper, long-channel flexible In0.7Ga0.3As Metal-Oxide-Semiconductor Field-Effect-Transistors (MOSFETs) have been fabricated and characterized utilizing liquid polyimide (LPI) transfer. The fabricated In0.7Ga0.3As flexible MOSFETs with Lg = 4 µm shows excellent DC and electrostatic integrity such as threshold voltage (VT) of -0.12 V, maximum transconductance (gm,max) of 265 µS/µm, subthreshold swing (SS) of 112 mV/dec, and drain-induced barrier lowering (DIBL) of 91 mV/V at VDS = 0.5 V, respectively. In addition, we have characterized gate length scaling behavior and our devices show uniform performances of VT = -0.11 to -0.15 V and SS = 108 to 118 mV/decade with various gate lengths ranging from 4 µm to 9 µm. Moreover, the device exhibits excellent effective mobility (μn_eff) = 3,667 cm2/V-s at room temperature. These excellent characteristics of the flexible In0.7Ga0.3As MOSFETs are attributed to optimized process technology for the flexible In0.7Ga0.3As MOSFETs using liquid polyimide (LPI) as well as high-κ dielectrics of Al2O3/HfO2 (0.6/2 nm) for the gate dielectrics.