Correlation between optical emission spectroscopy of hydrogen/germane plasma and the Raman crystallinity factor of germanium layers

Optical emission measurements were recorded during microcrystalline germanium layer growth on glass with plasma enhanced chemical vapor deposition. A significant difference for the intensities of SiH and GeH could be identified in the optical emission spectra of hydrogen/silane (H-2/SiH4) and hydrogen/germane (H-2/GeH4) plasma. In H-2/SiH4 plasma, Si and SiH are present, whereas Ge but no GeH could be detected in H-2/GeH4 plasma. The specific Raman crystallinity factor (phi(c)) was evaluated for the layers after deposition. In H-2/GeH4 plasma, the ratio of optical emission intensities of H-alpha (I(H-alpha), lambda = 656.28 nm) and Ge (I(Ge), lambda = 303.90 nm) is proportional to phi(c,Ge). (C) 2013 AIP Publishing LLC [http://dx.doi.org/10.1063/1.4802028]