Fabrication and Characterization of a Double Quantum Dot Structure

Abstract

We report the fabrication and characterization of a new type of double quantum dot (QD) structure. We utilize standard CMOS processing steps without any modification to fabricate the double QD. We form three CMOS poly-Si gates with oxide sidewall spacers in series on a silicon-on-insulator nanowire. The QDs are defined by implanted n+ region between the finger gates, and no negative bias on the finger gates is needed. The sidewall spacers act as implantation masks and the size of the QD is smaller than the lithographic spacing between two finger gates. Characterization results exhibit clear Coulomb oscillations with two peak splitting and saw-tooth shaped Coulomb diamond. The simulation based on the model of single electron tunneling through double QDs reproduces the measured results with reasonable parameters.