Crystallization of Semiconductor Thin Films by Flash Lamp Annealing

Flash lamp annealing (FLA) is a thermal treatment on the millisecond time scale which is used to crystallize semiconductor materials, especially if diffusion or segregation are unwanted processes. Crystallization is often needed after thin‐film deposition, after ion implantation, or to form compound materials for contacts. However, crystallization is a complex process that depends on the temperature profile during FLA, the availability and structure of seeds, and many other material properties. In this contribution, we discuss and compare different examples of thin‐film crystallization during FLA exposure. In the case of thin amorphous Ge layers on Ge fabricated by ion implantation, the mode of crystallization and thus the final result depends on the timing between incubation or seed formation and crystal growth. The formation of NiGe is a good example for a diffusion‐controlled crystallization in which intermediated NiGe x phases occur before the final, thermodynamically favored phase will be formed. Finally, different cases are discussed, in which different atomic species delay or promote crystallization and Sn segregation in Si–Ge–Sn alloys.