Deep Sub-Micron Self-Aligned Bottom-Gate Amorphous InGaZnO Thin-Film Transistors With Low-Resistance Source/Drain

A deep sub-micron self-aligned bottom-gate (SABG) amorphous InGaZnO (a-IGZO) thin-film transistor (TFT) technology was developed. The implementation of a backside exposure technique enables the realization of a self-aligned structure, while an argon (Ar) plasma treatment minimizes the source/drain resistance ( R SD ). High-performance metrics were well maintained on the fabricated SABG a-IGZO TFT with a channel length of 302 nm (effective channel length of 208 nm), including a low off-state current around 10 -14 A/μm, a subthreshold swing of 103.8 mV/dec, a decent mobility of 7.48 cm 2 /V∙s, a minor drain-induced barrier lowering (DIBL) of 41.5 mV/V, a negligible channel length shrinking (Δ L ) of 47 nm and a record-low R SD of 0.86 Ω∙cm among self-aligned (SA) transistors. Such remarkable scalability and manufacturing capability pave a new cost-effective way for high integration-density oxide electronics.