Structural properties of hydrogen-induced platelets in silicon: a Raman scattering study

Different treatments of hydrogenation induce hydrogen containing plate-like defects on {1 1 1} crystallographic planes in silicon. Several structural models of the platelets were proposed of which the most prominent are: (a) A double layer of interstitial hydrogen H-2(*) pairs and (b) hydrogen saturation of the Si-Si bonds at a {1 1 1} plane with H, molecules trapped within the platelet. Raman scattering studies reported that local vibrational modes related to the platelets appear around 2 100 cm(-1), whereas a local mode at 4160 cm(-1) was associated with H-2 trapped within the platelet. From an analysis of the polarized Raman scattering spectra of the 2100- and 4160-cm(-1) bands we identify two different types of {1 1 1}-platelets described above, which exist simultaneously with concentrations depending on plasma conditions. (C) 2001 Elsevier Science B.V. All rights reserved.