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

Abstract

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 (H2/SiH4) and hydrogen/germane (H2/GeH4) plasma. In H2/SiH4 plasma, Si and SiH are present, whereas Ge but no GeH could be detected in H2/GeH4 plasma. The specific Raman crystallinity factor (ϕc) was evaluated for the layers after deposition. In H2/GeH4 plasma, the ratio of optical emission intensities of Hα (I(Hα), λ = 656.28 nm) and Ge (I(Ge), λ = 303.90 nm) is proportional to ϕc,Ge.