High-Performance Self-Aligned Top-Gate Amorphous InGaZnO TFTs With 4 nm-Thick Atomic-Layer-Deposited AlOx Insulator

Electrical characteristics of self-aligned top-gate (SATG) amorphous InGaZnO (a-IGZO) thin-film transistors (TFTs) with 4 nm-thick atomic-layer-deposited (ALD) AlOx gate insulator (GI) are investigated. It is demonstrated that the SATG a-IGZO TFTs present high-performance metrics including a near-ideal subthreshold swing (SS) of 60.9 mV/dec, a low off-state current below 10(-12) A, a positive V-th of 0.1 V, and a decent mobility of 14.1 cm(2)/V . s. In addition, the TFTs exhibit negligible V-th shifts less than 0.02 V against electrical bias stresses. Both high performance and excellent stability are thus simultaneously achieved for the ultrathin GI of amorphous oxide semiconductor (AOS) TFTs.

Automated summary

Investigation of the electrical characteristics of self-aligned top-gate amorphous InGaZnO thin-film transistors reveals high-performance metrics and excellent stability. The transistors exhibit near-ideal subthreshold swing, low off-state current, positive threshold voltage, and decent mobility.