Electron tunneling in a strained n-type Si_(1-x)Ge_x/Si/Si_(1-x)Ge_x double-barrier structure

摘要

We report electrical measurements on an n-type Si_(1-x)Ge_x/Si/Si_(1-x)Ge_x double-barrier structure grown on a partially relaxed Si_(1-y)Ge_y buffer layer. Resonance tunneling of △_4 band electrons is demonstrated. This is attributed to the strain splitting in the SiGe buffer layer where the △_4 band is lowest in energy at the electrode. Since the △_4 band electrons have a much lighter effective mass along the direction of tunneling current in comparison with that of the △_2 band electrons, this work presents an advantage over those SiGe resonant-tunneling diodes in which tunneling of △_2 band electrons is employed.