Performance Enhancement and Mechanism Analysis of IGZO Thin-Film Transistors Utilizing Interdigital Structure

This study investigates the issue of leakage current reduction in oxide semiconductor thin-film transistors (TFTs) with interdigital structures. Electrical measurements clearly demonstrate that the leakage current of interdigitated IGZO devices decreases as the on/off ratio increases. To explore the reasons behind the reduction in leakage current, we conducted two-dimensional device simulations. The results confirm that the use of interdigital structures can influence the electric field distribution within the device channel, introducing shielding electric fields. As the number of interlayer structures between the source and drain increases, the shielding electric fields proportionally increase. Additionally, interdigitated IGZO devices exhibit a large on/off ratio exceeding 2.7×10 10 , an ultra-low leakage current of less than 3×10 -16 A/μm, and a high saturation mobility of 9.4 cm 2 /Vs. These findings provide valuable insights for designing low-power, high-performance devices based on IGZO.