Low-temperature (≤ 350 °C) aluminum-induced layer exchange enables the integration of large-grained polycrystalline silicon–germanium layers into silicon-based optical, electronic, and electromechanical sensors, either in post-processing or at the back-end-of-line of a CMOS flow. We systematically investigate how annealing conditions, metal composition, diffusion control layer, and Al/a-Ge thicknesses influence the crystallization process and the resulting silicon–germanium layer. Our results reveal tunable correlations between process parameters and layer properties, demonstrating that both the crystallinity and the composition of the final layer can be precisely controlled. This work provides practical guidelines for tailoring aluminum-induced layer exchange for silicon–germanium integration across diverse device applications.