Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1666037 | Thin Solid Films | 2013 | 4 Pages |
The Ni-metal-induced crystallization (MIC) of amorphous Si (α-Si) has been employed to fabricate low-temperature polycrystalline silicon (poly-Si) thin-film transistors (TFTs). Most studies have focused only on reducing Ni contamination because Ni residues cause high leakage current in MIC–TFTs. Also of concern is the source/drain (S/D) series resistance, which degrades the device performance (driving ability) that might vary with the Ni concentration in MIC–TFTs. Improving the driving ability of MIC–TFTs requires a detailed understanding of how Ni residues affect S/D series resistance. This study investigates how Ni concentration affects S/D series resistance by using the transmission line method. The results of this study provide further insight into how Ni concentration and resistance are related. The results show that the S/D series resistance and channel resistance decreased with a reduction in Ni concentration in MIC poly-Si because of better crystalline quality and lower degradation of the donor concentration. This phenomenon was caused by the Ni concentration forming less NiSi2 nucleation sites to generate a large grain size; Ni atoms serve as acceptor-like dopants in silicon, which counteract with the effects of n-type doping, subsequently reducing the donor concentration in the S/D region.
► Channel and source/drain resistance were decreased with reducing Ni concentration. ► Low Ni concentration formed less nucleation site of NiSi2 to cause large grain size. ► Ni serves as acceptor to counteract the effects of n-type doping in source/drain region.