Title :
Novel Symmetric Vertical-Channel Ni-Salicided Poly-Si Thin-Film Transistors With High on/off-Current Ratio
Author :
Wu, Yi-Hong ; Kuo, Po-Yi ; Lu, Yi-Hsien ; Chen, Yi-Hsuan ; Chao, Tien-Sheng
Author_Institution :
Dept. of Electrophys., Nat. Chiao Tung Univ., Hsinchu, Taiwan
Abstract :
We have successfully fabricated the symmetric vertical-channel Ni-salicided polycrystalline silicon thin-film transistors (VSA-TFTs) for the first time. The transfer characteristics of VSA-TFTs show a sharp turning between subthreshold and on state. The off -state currents can be improved by a modified overetching of oxide, equivalent dual-gate structure, and n+ floating-region length. The on-state currents can be enhanced by Ni-salicidation. The VSA-TFTs display a good subthreshold swing of 220 mV/dec, steep mobility increase (field-effect mobility of 76 cm2/V·s), and large on/off-current ratio of more than 109 (IOFF = 4 × 10-14, ION = 7 × 10-5, and Wmask/Lmask = 10 μm/3 μm).
Keywords :
elemental semiconductors; etching; silicon; thin film transistors; VSA-TFT; equivalent dual-gate structure; field-effect mobility; floating-region length; off -state current; on-state current; overetching; steep mobility; subthreshold swing; symmetric vertical-channel Ni-salicided polycrystalline silicon thin-film transistor; transfer characteristics; Leakage current; Logic gates; Resistance; Silicon; Thin film transistors; Ni-salicided; polycrystalline silicon thin-film transistors (poly-Si TFTs); symmetric S/D; vertical channel;
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2010.2061215
