Improved Electrical Performance and Reliability of Poly-Si TFTs Fabricated by Drive-In Nickel-Induced Crystallization with Chemical Oxide Layer

Abstract

Ni-metal-induced crystallization (MIC) of amorphous Si (alpha-Si) has been employed to fabricate low-temperature polycrystalline silicon thin-film transistors (TFTs). However, the Ni residues degrade the device performance. In this study, a new method for manufacturing MIC-TFTs using drive-in Ni-induced crystallization with a chemical oxide layer (DICC) is proposed. Compared with that of MIC-TFTs, the on/off current ratio (I (on)/I (off)) of DICC-TFTs was increased by a factor of 9.7 from 9.21 x 10(4) to 8.94 x 10(5). The leakage current (I (off)) of DICC-TFTs was 4.06 pA/mu m, which was much lower than that of the MIC-TFTs (19.20 pA/mu m). DICC-TFTs also possess high immunity against hot-carrier stress and thereby exhibit good reliability.