Improved Electrical Performance of NILC Poly-Si TFTs Manufactured Using H2SO4 and HCl Solution

Low-temperature polycrystalline silicon (poly-Si) thin-film transistors (TFTs) have attracted considerable interest for their application in active-matrix liquid crystal displays (AMLCDs) (1,2). Intensive studies on reducing the crystallization time and temperature of amorphous silicon (α-Si) have been carried out. Nickel-induced lateral crystallization (NILC) is one of these efforts (3,4). Unfortunately, poly-Si/oxide interfaces and grain boundaries trap Ni and NiSi2 (Ni-related defects), which degrades its electric performance (5,6). Several metal gettering methods have been employed to reduce the amount of undesired metallic impurities in Si. However these gettering methods are complicated and require high process temperatures. In this study, we used a simple and low thermal budget chemical treatment to reduce Ni residuals.