  The versatility of properties displayed by two-dimensional electron gases
(2DEGs) at oxide interfaces has fostered intense research in hope of achieving
exotic electromagnetic effects in confined systems. Of particular interest is
the recently discovered superconducting state appearing in (111)-oriented
KTaO$_3$ interfaces, with a critical temperature $T_c \approx 2$ K, almost ten
times higher than that of SrTiO$_3$-based 2DEGs. Just as in SrTiO$_3$-based
2DEGs, fabricating devices in this new system is a technical challenge due to
the fragility of the 2DEG and the propensity of bulk KTaO$_3$ to become
conducting outside the devices upon adventitious oxygen vacancy doping. Here,
we present three different techniques for patterning Hall bars in
AlO$_x$/KTaO$_3$~(111) heterostructures. The devices show superconducting
transitions ranging from 1.3 K to 1.78 K, with limited degradation from the
unpatterned thin film, and enable an efficient tuning of the carrier density by
electric field effect. The array of techniques allows for the definition of
channels with a large range of dimensions for the design of various kinds of
devices to explore the properties of this system down to the nanoscale.
