Intrinsic microcrystalline silicon by plasma-enhanced chemical vapor deposition from dichlorosilane

Microcrystalline silicon $\mathrm{(\mu c-}\mathrm{Si:H})$ of truly intrinsic character can be deposited by plasma-enhanced chemical vapor deposition (PECVD) when dichlorosilane $({\mathrm{SiH}}_{\mathrm{2}}{\mathrm{Cl}}_{\mathrm{2}})$ is added. A dark conductivity of ${\text{1.6×10}}^{\text{−8}}$ S/cm and an activation energy of 0.62 eV are obtained. No special gas purification or microdoping is required. ${\mathrm{SiH}}_{\mathrm{2}}{\mathrm{Cl}}_{\mathrm{2}}$ in small amounts has the additional effect of enhancing the crystallinity and reducing the oxygen incorporation by over a factor of 2. Sub-band-gap absorption spectroscopy indicates a low defect density.