Title :
Self-Aligned Coplanar a-IGZO TFTs and Application to High-Speed Circuits
Author :
Dong Han Kang ; In Kang ; Sang Hyun Ryu ; Jin Jang
Author_Institution :
Dept. of Inf. Display, Kyung Hee Univ., Seoul, South Korea
Abstract :
We report a self-aligned coplanar amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistor (TFT) using an a-IGZO/SiO2 stack layer. From the channel-length dependence of the total resistance for the TFTs, the channel and parasitic resistances were found to be 8.4 kΩ/μm and 9.7 kΩ/sq, respectively. The fabricated a-IGZO TFT exhibits field-effect mobility of 23.3 cm2/V ·s, threshold voltage of 3.6 V, and gate voltage swing of 203 mV/dec. A 23-stage ring oscillator made of the self-aligned TFTs exhibits a propagation delay time of 17 ns/stage at a supply voltage of 22 V.
Keywords :
gallium compounds; high-speed integrated circuits; indium compounds; oscillators; semiconductor device manufacture; thin film transistors; zinc compounds; high-speed circuits; ring oscillator; self-aligned coplanar TFT; thin-film transistor; voltage 22 V; voltage 3.6 V; Logic gates; Resistance; Solids; Thin film transistors; Threshold voltage; Amorphous indium–gallium–zinc–oxide (a-IGZO); coplanar; ring oscillator (RO); self-aligned process; thin-film transistor (TFT);
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2011.2161568
