Aligned Ion Implantation Using Scanning Probes

A new technique for precise ion implantation has been§developed using a scanning probe that has been§equipped with a small aperture and incorporated into§an ion beamline. Ions are passed through the aperture§and implanted into a sample. By using a scanning§probe the target can be imaged in a non-destructive§way prior to implantation. The probe can be placed at§the desired location with nanometer precision.§§§With this approach a final placement accuracy of§about 10 nm is envisioned, limited by straggling and§the aperture size. In this work a feature size down§to 120 nm has been demonstrated.§§§This research is part of a program for the§development of test structures for a quantum§computer. For this application the placement accuracy§needs to be increased and a detector for single ion§detection has to be integrated into the setup. Both§these issues are discussed.§§§To achieve single ion detection highly charged ions§are used, since the additional potential energy§released by these ions on impact should lead to an§easier detection of each ion. The highly charged ions§were produced using a specialized ion source and§their creation and interactions with solids are§described in detail.