Ammonia as a precursor in electron-enhanced nitridation of Si(100)

Electron beam-enhanced nitridation of Si(100) using ammonia as a precursor at 110 K was studied with electron-stimulated desorption, XPS, AES and high -resolution electron energy-loss spectroscopy (HREELS), Hydrogen ion kineti c energy distributions from adsorbed ammonia exhibited a component from NH3 (a) at 7.8 eV, from NH2(a) at 5.4 eV and from H(a) at 4 eV, Formation of th e nitride following electron beam irradiation of adsorbed ammonia was shown by both N Is at 398 eV and Si 2p at 102 eV in XPS spectra, From HREELS spe ctra following electron beam irradiation, we are able to show that the elec tron beam is highly effective in removal of hydrogen from NHx(a) (x = 3,2) and from the silicon surface. Electron-stimulated desorption of adsorbed hy drogen and dissociation of adsorbed NHx (x = 3,2) are believed to be respon sible for enhanced nitridation, Nitride can also form on the surface by irr adiating the surface in an ammonia environment at 110 K, A nitride growth r ate of 1 Angstrom min(-1) was obtained from the bulk Si LVV AES signal inte nsity attenuation. Copyright (C) 2000 John Wiley & Sons, Ltd.