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.