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

Volume

49

Issue

12

fYear

2002

fDate

12/1/2002 12:00:00 AM

Firstpage

2217

Lastpage

2221

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;

fLanguage

English

Journal_Title

Electron Devices, IEEE Transactions on

Publisher

ieee

ISSN

0018-9383

Type

jour

DOI

10.1109/TED.2002.805234

Filename

1177987