Lateral Solid Phase Recrystallization from the Crystal Seed in Ge-Ion-Implanted Amorphous Silicon Films by Repetition Rapid Thermal Annealing

Lateral solid-phase recrystallization (LSPR) from the crystal seed selectively formed by excimer laser annealing in Ge-ion-implanted amorphous silicon (a-Si) is performed by rapid thermal annealing (RTA). The process is carried out as a basic research study to grow grains in the current direction along the channel from the drain to the source in poly-Si thin film transistors. In this letter, it is shown that repetition RTA, in which on/off of the setting temperature is periodically repeated with a certain heat pulse width, suppresses the random nucleation in a-Si films and enlarges LSPR grains compared with single RTA, when the heat pulse width is sufficiently shorter than the incubation time which is the time before the onset of nucleation.