Solid phase amorphization in multilayer structures consisting of alternating layers of crystalline Rh and amorphous Si thin films and in a bilayer structure consisting of a crystalline Rh thin film deposited on a  oriented single crystal Si wafer have been studied by in situ resistivity measurement and cross-sectional transmission electron microscopy. In both of the structures, amorphous alloys of Rh and Si form upon heating from 120 to 250 °C. The metastability of the amorphous alloy as measured by the crystallization temperature depends on the alloy composition and the initial layer thickness of Rh and Si. The amorphous alloy that has a composition close to that of RhSi is quite stable and has a crystallization temperature of around 450 °C. Its kinetics of solid state amorphization and crystallization have been measured and are discussed.