  Fabrication of sub-micron Josephson junctions is demonstrated using standard
processing techniques for high-coherence, superconducting qubits. These
junctions are made in two separate lithography steps with normal-angle
evaporation. Most significantly, this work demonstrates that it is possible to
achieve high coherence with junctions formed on aluminum surfaces cleaned in
situ with Ar milling before the junction oxidation. This method eliminates the
angle-dependent shadow masks typically used for small junctions. Therefore,
this is conducive to the implementation of typical methods for improving
margins and yield using conventional CMOS processing. The current method uses
electron-beam lithography and an additive process to define the top and bottom
electrodes. Extension of this work to optical lithography and subtractive
processes is discussed.
