In situ x-ray diffraction study of metal induced crystallization of amorphous germanium

Abstract

Metal induced crystallization (MIC) is a technique that lowers the crystallization temperature of amorphous semiconductors. The process has mainly been used to influence the crystallization of amorphous silicon (a-Si) and multiple studies on this subject have already been performed. The research of the MIC of amorphous Ge (a-Ge) has been mostly limited to the use of a Ni or Al film. This paper focuses on the characterization of the crystallization behavior of a-Ge films in the presence of 20 transition metals (Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Re, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, and Al). The kinetics of the crystallization process are also systematically studied for the seven metals that lower the initial crystallization temperature the most. In addition, the influence of the thickness of the metal film was determined for the case of a Au and Al film. A comparison of the influence of the various metals on a-Ge and a-Si is made and the similarities and differences are discussed using existing models for the MIC process.