Profiling Mobility Components Near the Heterointerfaces of Thin Silicon Films

A method for profiling the components of effective carrier mobility μeff determined by scattering at surface phonons and the roughness of thin film/dielectric interfaces is proposed. The method is based on controlled carrier localization relative to the tested heterointerface due to the interrelation of potentials on opposite film sides (the coupling effect). The method makes it possible to independently separate mobility components near different film heterointerfaces. Its use when studying the electron mobility in silicon-on-insulator films makes it possible to acquire information on the interface roughness and structural perfection of an ultrathin (1–3 nm) silicon layer near the buried film/dielectric interface.