Deep-Submicron Channel Length Oxide Semiconductor Thin-Film Transistors Enabled by Self-Aligned Nanogap Lithography

This study presents the fabrication of oxide semiconductor thin-film transistors (TFTs) with a channel length of 60 nm, which is made possible through self-aligned nanogap lithography. The TFTs feature a 6-nm-thick Al-doped InZnSnO semiconductor layer and a 10-nm-thick Al ₂ O ₃ gate dielectric, arranged in a bottom gate top contact configuration. Key performance metrics include a subthreshold swing of 92 mV/dec, an on/off current ratio exceeding 10 ¹⁰ , and a turn-on voltage of -0.91 V. The driving current at a gate bias of 2 V and a drain bias of 1.5 V reached 290 μA/μm. Additionally, the study observed a drain-induced barrier lowering of approximately 250 mV/V for the TFTs examined in this research.