Title :
A novel germanium doping method for fabrication of high-performance p-channel poly-Si1-xGex TFT by excimer laser crystallization
Author :
Ting-Kuo Chang ; Fang-Tsun Chu ; Ching-Wei Lin ; Chang-Ho Tseng ; Huang-Chung Cheng
Author_Institution :
Dept. of Electron. Eng., Nat. Chiao Tung Univ., Hsinchu, Taiwan
fDate :
4/1/2003 12:00:00 AM
Abstract :
A novel process for fabricating p-channel poly-Si/sub 1-x/Ge/sub x/ thin-film transistors (TFTs) with high-hole mobility was demonstrated. Germanium (Ge) atoms were incorporated into poly-Si by excimer laser irradiation of a-Si/sub 1-x/Ge/sub x//poly-Si double layer. For small size TFTs, especially when channel width/length (W/L) was less than 2 μm/2 μm, the hole mobility of poly-Si/sub 1-x/Ge/sub x/ TFTs was superior to that of poly-Si TFTs. It was inferred that the degree of mobility enhancement by Ge incorporation was beyond that of mobility degradation by defect trap generation when TFT size was shrunk to 2 μm/2 μm. The poly-Si/sub 0.91/Ge/sub 0.09/ TFT exhibited a high-hole mobility of 112 cm2/V-s, while the hole mobility of the poly-Si counterpart was 73 cm2/V-s.
Keywords :
Ge-Si alloys; crystallisation; hole mobility; laser beam annealing; semiconductor doping; semiconductor materials; thin film transistors; SiGe; defect trap; excimer laser crystallization; fabrication process; germanium doping; hole mobility; p-channel poly-Si/sub 1-x/Ge/sub x/ thin film transistor; Atom lasers; Atomic beams; Atomic layer deposition; Crystallization; Displays; Doping; Germanium; Optical device fabrication; Silicon; Thin film transistors;
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/TCSI.2003.811423
