Single ion implantation for solid state quantum computer development

Several solid state quantum computer schemes are based on the manipulation of electron and/or nuclear spins of single 31P atoms in a solid matrix. The fabrication of qubit arrays requires the placement of individual atoms with nanometer precision and high efficiency. We describe the status of our development of a low energy, single ion implantation scheme for 31Pq+ ions. High ion charge states enable registration of single ion impacts with unity efficiency through the detection of secondary electrons. Imaging contrast in secondary electron emission allows alignment of the implantation and integration with consecutive lithography steps. Critical issues of process integration and resolution limiting factors are discussed.