Title :
Electrical Performance Enhancement of Al–Zn-Sn–O Thin Film Transistor by Supercritical Fluid Treatment
Author :
Li-Feng Teng ; Po-Tsun Liu ; Wei-Ya Wang
Author_Institution :
Dept. of Photonics, Nat. Chiao Tung Univ., Hsinchu, Taiwan
Abstract :
In this letter, a low-temperature supercritical fluid (SCF) treatment was employed to enhance the electrical and optical properties of amorphous Al-Zn-Sn-O thin film transistors (a-AZTO TFTs) for flat-panel displays. The carrier mobility and threshold voltage of a-AZTO TFT were improved significantly after SCF process because of the reduction of trap density in the a-AZTO active layer. In addition, the SCF-treated a-AZTO TFT exhibited superior electrical reliability and less degradation after negative gate bias illumination stress. X-ray photoelectron spectroscopy analysis confirmed that the proposed SCF treatment could effectively oxidize a-AZTO film and change the oxidation states of Sn, resulting in the improvement of a-AZTO TFT device characteristics.
Keywords :
X-ray photoelectron spectra; aluminium compounds; amorphous semiconductors; carrier mobility; electron traps; flat panel displays; oxidation; semiconductor device reliability; stress effects; thin film transistors; tin compounds; zinc compounds; AlZnSnO; SCF treatment; X-ray photoelectron spectroscopy analysis; a-AZTO TFT device; active layer; amorphous thin film transistors; carrier mobility; electrical performance enhancement; electrical properties; electrical reliability; flat-panel displays; low-temperature supercritical fluid treatment; negative gate bias illumination stress; optical properties; oxidation states; threshold voltage; trap density reduction; Logic gates; Metals; Stress; Thin film transistors; Threshold voltage; Water; Al–Zn-Sn–O thin film transistor (Al–Zn-Sn–O TFT); supercritical fluid (SCF); transparent amorphous oxide semiconductor (TAOS);
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2013.2272117
