Title :
Surface treatment effect on the poly-Si TFTs fabricated by electric field enhanced crystallization of Ni/a-Si:H films
Author :
Kim, Binn ; Kim, Hae-Yeol ; Seo, Hyun-Sik ; Kim, Sung Ki ; Kim, Chang-Dong
Author_Institution :
LCD Res. & Dev. Center, LG Philips, Kyunggi-Do, South Korea
Abstract :
Self-aligned, p-channel polycrystalline silicon thin-film transistors (TFTs) were fabricated by electric field enhanced crystallization of a-Si:H in contact with the Ni catalyst, where a chemical solution of 97.5% H/sub 2/O:1% HF:1.5% H/sub 2/O/sub 2/ was used for a surface treatment on polycrystalline silicon films. The wet surface treatment was found to remarkably improve the electrical properties of TFTs, especially the leakage current and subthreshold slope. The enhanced performance was confirmed to be from the removal of the Ni impurity remaining as defect states at the surface and also from the ameliorated surface roughness of the polycrystalline silicon films.
Keywords :
X-ray fluorescence analysis; atomic force microscopy; crystallisation; crystallites; defect states; elemental semiconductors; leakage currents; semiconductor thin films; silicon; surface cleaning; surface roughness; thin film transistors; AFM; Ni impurity removal; Si; ameliorated surface roughness; electric field enhanced crystallization; energy dispersive X-ray fluorescence; leakage current; needle-like crystallites; polycrystalline silicon films; polysilicon TFT; self-aligned p-channel TFT; subthreshold slope; surface defect states; surface treatment effect; wet surface treatment; Chemicals; Crystallization; Impurities; Leakage current; Rough surfaces; Semiconductor films; Silicon; Surface roughness; Surface treatment; Thin film transistors;
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2003.820626
