Excimer laser annealing suppresses the bubbles in the recrystallization of argon-implantation induced amorphous germanium

We have investigated the recrystallization behavior of the argon (Ar) bubble-rich amorphous germanium (a-Ge) by utilizing the excimer laser annealing (ELA) in comparison with the conventional furnace annealing (FA). We demonstrate that the ELA can efficiently suppress the Ar bubbles to have good recrystallization of a-Ge in sharp contrast to the conventional FA treatment where the bubble-rich a-Ge can only be getting partial recrystallization with many dislocations and stacking faults. Transmission electron microscopy results exhibit that ELA can transform the Ar implantation-induced damaged layer into a fully crystalline matrix containing no visible defects except isolated bubbles in a low density. We reveal the critical role of the Ar bubbles played in the recrystallization behavior of the a-Ge by comparing the two types of annealing methods. This finding provides a new routine to suppress the implantation-induced noble-gas bubbles in semiconductors to solve the issue of the high-quality regrowth of the noble-gas implanted layer.