Electric-field-dependent spectroscopy of charge motion using a single-electron transistor

摘要

We present observations of background charge fluctuators near an Al-AlO_x-Alsingle-electron transistor on an oxidized Si substrate. The transistor designincorporates a heavily doped substrate and top gate, which allow forindependent control of the substrate and transistor island potentials. Throughcontrolled charging of the Si/SiO_2 interface we show that the fluctuatorscannot reside in the Si layer or in the tunnel barriers. Combined with thelarge measured signal amplitude, this implies that the defects must be locatedvery near the oxide surface.