High-performance low-temperature p-channel polycrystalline-germanium thin-film transistors via continuous wave laser crystallization

The continuous wave laser crystallization (CLC) has been considered as a suitable approach to achieve the high-quality Ge films. In order to further overcome the hole concentration of Ge thin films resulting from the acceptor-like defects, the counter-doping (CD) process with a suitable dose of n-type dopants was employed to convert the carrier type in Ge thin films. In this study, the high-performance low-temperature p-channel polycrystalline-germanium thin-film transistors (TFTs) have been demonstrated via continuous wave laser crystallization and counter doping to exhibit the low subthreshold swing of 432 mV/decade, a superior on/off current ratio of 4×103 and a high hole field-effect mobility of 290 cm2/V-s.