  We have looked into cobalt disilicide (CoSi$_2$) as a potential building
block for superconducting quantum circuits. In order to achieve this, we
annealed a thin layer of Co to create 10-105 nm thick microwave cavities from
CoSi$_2$ embedded in the silicon substrate. The cavity properties were measured
as a function of temperature and power. In films measuring 10 and 25 nm, we
find a significant kinetic inductance $L_\mathrm{K}$ with a non-BCS power-law
variation $\delta L_\mathrm{K} \propto T^{4.3 \pm 0.2}$ at low temperatures.
The quality factor of the studied microwave resonances increased almost
linearly with thickness, with two-level systems having very little effect. The
power dependence of kinetic inductance was analyzed in terms of heat flow due
to electron-phonon coupling, which was found stronger than estimated for heat
relaxation by regular quasiparticles.
