“…After RTA processes above 500 C, the samples underwent a severe morphological degradation without maintaining film continuity known as agglomeration. In other word, with increasing RTA temperature above 500 C, in order to minimize the total energy of the system [26,27], the groove in the interface between Cu 3 Ge and Ge substrate as indicated by an arrow in Fig. 3(c) grew through the entire Cu 3 Ge layer, leading to the physical separation of Cu 3 Ge grains from each other.…”