Studies of Semiconductor Surfaces: Vibrational Spectroscopy of Adsorbates
This chapter gives a self-contained but small overview of some of the vibrational spectroscopy performed on silicon surfaces to highlight the method used and the information content extracted with multiple internal reflection spectroscopy. Infrared spectroscopy is often referred to as a “fingerprint” technique because measured vibrational lines can be compared to well-catalogued standards and thus assigned. The assignment of vibrational modes at surfaces is more difficult because adsorbates bound to surfaces display substantial frequency shifts in their vibrational modes. Standards are therefore scarce and less reliable. On the other hand, adsorbates on well-ordered single crystal surfaces are oriented with respect to the surface and characterized by relatively narrow lines.