Characterizing the Electrical Properties of a Novel Junctionless Poly-Si Ultrathin-Body Field-Effect Transistor Using a Trench Structure

Ultrathin channel trench junctionless poly-Si field-effect transistor (trench JL-FET) with a 2.4-nm channel thickness is experimentally demonstrated. Dry etching process is used to form trench structures, which define channel thickness (T_CH) and gate length (L_G). These devices (L_G = 0.5 μm) show excellent performance in terms of steep subthreshold swing (100 mV/decade) and high I_ON/I_OFF current ratio (106A/A) and practically negligible drain-induced barrier lowering (~0 mV/V). The I_ON current of the trench JL-FET can be further increased by the quantum confinement effect. Importantly, owing to its excellent device characteristics and simplicity of fabrication, the trench JL-FET has great potential for using in advanced 3-D-stacked IC applications.