A novel, low temperature process for the formation of Si-BC8 phase is obtained while growing Silicon nanowires. The nanowires growth is performed in a CVD reactor under exposure of the substrate to microwaves, employing Sn nanospheres as catalyst and a flux of SiH₄ as precursor, respectively. Microwaves allow for selective heating of the metal catalyst while keeping the substrate at low temperature. At the end of the process, silicon nanowires with the metal sphere on top are obtained, together with the (unexpected) transition of a portion of silicon substrate from the diamond to the Si-BC8 crystallographic phase. Silicon atoms in Si-BC8 phase are arranged in body-centered-cubic unit cells resulting into a different energy-wavevector diagram compared to the silicon diamond cubic phase. Indeed, Si-BC8 possesses a direct band gap as low as 30 meV at room temperature. These features may be employed in a large variety of applications, requiring CMOS-compatible manufacturing.

Systematic structural analysis and a phenomenological model for Si-BC8 phase formation are discussed.

在生长硅纳米线的同时，获得了一种用于形成 Si-BC8 相的新型低温工艺。纳米线生长在 CVD 反应器中进行，基板暴露于微波，采用 Sn 纳米球作为催化剂和 SiH ₄通量分别作为前驱。微波允许选择性加热金属催化剂，同时将基材保持在低温。在该过程结束时，获得顶部带有金属球的硅纳米线，以及一部分硅衬底从金刚石到 Si-BC8 晶相的（意外）转变。与硅金刚石立方相相比，Si-BC8 相中的硅原子排列在体心立方晶胞中，从而形成不同的能量波矢量图。事实上，Si-BC8 在室温下具有低至 30 meV 的直接带隙。这些功能可用于需要与 CMOS 兼容的制造的多种应用。

讨论了 Si-BC8 相形成的系统结构分析和现象学模型。