Title :
High field-effect-mobility a-Si:H TFT based on high deposition-rate PECVD materials
Author :
Chen, Chun-ying ; Kanicki, Jerzy
Author_Institution :
Dept. of Electr. Eng. & Comput. Sci., Michigan Univ., Ann Arbor, MI, USA
Abstract :
The hydrogenated amorphous silicon (a-Si:H) thin-film transistors (TFT´s) having a field-effect mobility of 1.45 /spl plusmn/0.05 cm/sup 2//V/spl middot/s and threshold voltage of 2.0/spl plusmn/0.2 V have been fabricated from the high deposition-rate plasma-enhanced chemical vapor deposited (PECVD) materials. For this TFT, the deposition rates of a-Si:H and N-rich hydrogenated amorphous silicon nitride (a-SiN/sub 1.5/:H) are about 50 and 190 nm/min, respectively. The TFT has a very high ON/OFF-current ratio (of more than 10/sup 7/), sharp subthreshold slope (0.3/spl plusmn/0.03 V/decade), and very low source-drain current activation energy (50/spl plusmn/5 meV). All these parameters are consistent with a high mobility value obtained for our a-Si:H TFT structures. To our best knowledge, this is the highest field-effect mobility ever reported for an a-Si:H TFT fabricated from high deposition-rate PECVD materials.
Keywords :
amorphous semiconductors; carrier mobility; elemental semiconductors; hydrogen; plasma CVD; semiconductor growth; semiconductor thin films; silicon; thin film transistors; 1.8 to 2.2 V; ON/OFF-current ratio; PECVD materials; Si:H; TFT; deposition rates; field-effect-mobility; source-drain current activation energy; subthreshold slope; threshold voltage; Amorphous silicon; Etching; Frequency; Hydrogen; Optical films; Photonic band gap; Plasma chemistry; Plasma materials processing; Thin film transistors; Throughput;
Journal_Title :
Electron Device Letters, IEEE
