  Intrinsic Josephson junction (IJJ) stacks of cuprate superconductors have
potential to be implemented as intrinsic phase qubits working at relatively
high temperatures. We report success in fabricating submicron
La$_{2-x}$Sr$_{x}$CuO$_{4}$ (LSCO) IJJ stacks carved out of single crystals. We
also show a new fabrication method in which argon ion etching is performed
after focused ion beam etching. As a result, we obtained an LSCO IJJ stack in
which resistive multi-branches appeared. It may be possible to control the
number of stacked IJJs with an accuracy of a single IJJ by developing this
method.
