Observation of two-dimensional electron gas in a Si quantum well with mobility of 1.6×106 cm2/Vs

We report the observation of a two-dimensional electron gas (2DEG) in a Si quantum well with mobility 1.6×106 cm2/Vs at carrier densities n≥1.5×1011/cm2. The 2DEG, which resides in an undoped Si/SiGe heterostructure, is capacitively induced using an insulated-gate field-effect transistor (IGFET) device structure; its mobility is determined from transport and quantum Hall effect measurements at 0.3 K. Our IGFET device makes it now possible to access by transport experiments the low electron density regime down to n∼1×1010/cm2.