Title :
Polycrystalline silicon thin-film transistors fabricated by defect reduction methods
Author :
Watakabe, H. ; Sameshima, T.
Author_Institution :
Dept. of Electr. & Electron. Eng., Tokyo Univ. of Agric. & Technol., Japan
fDate :
12/1/2002 12:00:00 AM
Abstract :
Fabrication of n-channel polycrystalline silicon thin-film transistors (poly-Si TFTs) at a low temperature is reported. 13.56 MHz-oxygen plasma at a 100 W, 130 Pa at 250°C for 5 min, and heat treatment at 260°C with 1.3×106-Pa-H2O vapor for 3 h were applied to reduction of the density of defect states in 25-nm-thick silicon films crystallized by irradiation of a 30 ns-pulsed XeCl excimer laser. Defect reduction was numerically analyzed. Those treatments resulted in a high carrier mobility of 830 cm2/Vs and a low threshold voltage of 1.5 V at a laser crystallization energy density of 285 mJ/cm2.
Keywords :
carrier mobility; crystallisation; defect states; elemental semiconductors; heat treatment; laser materials processing; plasma materials processing; silicon; thin film transistors; 1.3×106 Pa; 100 W; 13.56 MHz; 130 Pa; 250 degC; 260 degC; RF oxygen plasma; Si; carrier mobility; crystallization; defect reduction; defect state density; heat treatment; low temperature fabrication; n-channel polycrystalline silicon thin film transistor; pulsed XeCl excimer laser irradiation; threshold voltage; water vapor; Crystallization; Heat treatment; Liquid crystal displays; Optical device fabrication; Plasma density; Plasma displays; Plasma temperature; Semiconductor films; Silicon; Thin film transistors;
Journal_Title :
Electron Devices, IEEE Transactions on
DOI :
10.1109/TED.2002.805234
