Title :
High-performance RSD poly-Si TFTs with a new ONO gate dielectric
Author :
Chang, Kow-Ming ; Yang, Wen-Chih ; Hung, Bing-Fang
Author_Institution :
Dept. of Electron. Eng., Nat. Chiao-Tung Univ., Hsinchu, Taiwan
fDate :
6/1/2004 12:00:00 AM
Abstract :
This paper developed a novel polycrystalline silicon (poly-Si) thin-film transistor (TFT) structure with the following special features: 1) a new oxide-nitride-oxynitride (ONO) multilayer gate dielectric to reduce leakage current, improved breakdown characteristics, and enhanced reliability; and 2) raised source/drain (RSD) structure to reduce series resistance. These features were used to fabricate high-performance RSD-TFTs with ONO gate dielectric. The ONO gate dielectric on poly-Si films shows a very high breakdown field of 9.4 MV/cm, a longer time dependent dielectric breakdown, larger QBD, and a lower charge-trapping rate than single-layer plasma-enhanced chemical vapor deposition tetraethooxysilane oxide or nitride. The fabricated RSD-TFTs with ONO gate dielectric exhibited excellent transfer characteristics, high field-effect mobility of 320 cm2/V·s, and an on/off current ratio exceeding 108.
Keywords :
chemical vapour deposition; dielectric materials; dielectric thin films; elemental semiconductors; leakage currents; silicon; thin film transistors; N2 O-plasma oxynitride; ONO gate dielectric; ONO multilayer gate dielectric; RSD structure; TFT structure; breakdown characteristics; charge-trapping rate; field-effect mobility; high-performance RSD poly-Si TFT; leakage current reduction; nitride; on/off current ratio; oxide-nitride-oxynitride; poly-Si films; polycrystalline silicon; raised source/drain structure; reliability; series resistance; single-layer plasma-enhanced chemical vapor deposition; tetraethooxysilane oxide; thin-film transistor; time dependent dielectric breakdown; transfer characteristics; Chemical vapor deposition; Dielectric breakdown; Dielectric substrates; Dielectrics and electrical insulation; Electric breakdown; Glass; Leakage current; Nonhomogeneous media; Silicon; Thin film transistors; $hbox N_2hbox O$ -plasma oxynitride; Gate dielectric; ONO; RSD; TFTs; oxide–nitride–oxide; raised source/drain; thin-film transistors;
Journal_Title :
Electron Devices, IEEE Transactions on
DOI :
10.1109/TED.2004.827382
