Characterization of the Si/SiGe heterojunction diode grown by ultrahigh vacuum chemical vapor deposition

摘要

The unipolar Si/SiGe heterojunction diode grown by ultrahigh vacuum chemical vapor deposition at 550thinsp;deg;C is demonstrated. The dark current density measured at 77 K is (2.5plusmn;0.1)times;10minus;7A/cm2for the barrier height of 176plusmn;8 meV, at a reverse bias of 1 V. The barrier heights are measured from the activation analysis of the saturation current and compared to the theoretical values. The barrier height decreases as the thickness of the SiGe strained layer exceeds the critical thickness.