  Motivated by potential transformative applications of nanoelectronic circuits
that incorporate superconducting elements, and by the advantages of integrating
these elements in a silicon materials platform, we investigate the properties
of the superconductivity of silicon ion-implanted with gallium. Here we measure
40 different samples and explore both a variety of preparation methods
(yielding both superconducting and non-superconducting samples), and the
reproducibility of one of the preparation methods yielding superconducting
samples. While we find agreement with the existing literature that
superconducting effects are visible in this system, we also find that this
superconductivity is not influenced by voltages applied to a top gate. The
superconductivity in this materials system is not gateable for applied electric
fields as large as 8 MV/cm. We also present results of scanning transmission
electron microscopy imaging of some of the same samples for which we report
electronic characterization. In agreement with the existing literature, we find
that the presence of Ga precipitates is essential to the presence of a
superconducting transition in these samples. However, we also find evidence for
large inhomogeneities in this system, which we discuss in connection with the
lack of gateability we report here.
