Si quantum dots with focused ion beam implanted phosphorus donors

Integrating MOS quantum dots with an on-chip ion detector allows for accurate counting of the number of ions implanted into a nanostructure. We present our recent progress in integrating deterministic single ion implantation with Si MOS quantum dot qubits. A MOS quantum dot system is first fabricated with standard e-beam lithography and etching of poly-silicon. Phosphorus ions are implanted into the target zones using a focused ion beam with a beam size of 40 nm at 45 keV in Sandia’s nano-implanter. Two well behaved lithographic MOS quantum dots are formed by electrostatic gating. One quantum dot is used as a charge sensor, while the other can be tuned from the many-electron to the few-electron regime. Donor-like objects that are coupled to the quantum dot are identified and characterized by capacitances measurements. This work was performed, in part, at the Center for Integrated Nanotechnologies, a U.S. DOE, Office of Basic Energy Sciences, user facility. Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA-0003525.