Photo-induced current transient spectroscopy was used to investigate the defect states and capture kinetics of charge carriers for traps in low-temperature polycrystalline silicon (poly-Si) films. A broad deep trap was found to be located 0.30eV from the conduction band edge of poly-Si with capture cross-section of 1.51 x 10-15cm2. The variation of the trap capture kinetics with filling pulse time showed extended traps and linear arrays of traps, which might be grain boundary defects. Proton implantation and H-plasma treatment were used to improve poly-Si device characteristics, with traps more effectively suppressed by the former treatment. The ionized hydrogen atoms implanted into the poly-Si films were imputed to amorphize the defective poly-Si film with post-annealing enhancing re-crystallization, resulting films with fewer defects.

Analysis of Deep-Level Defects on Proton Implanted Polycrystalline Silicon Thin Films Using Photoinduced Current Transient Spectroscopy. W.S.Kim, D.H.Kim, D.W.Kwak, D.W.Lee, Y.H.Lee, H.Y.Cho: Japanese Journal of Applied Physics, 2010, 49[12], 125802