| he reaction mechanisms of nitrogen containing compounds on semiconductor surfaces and the structure of nitrogen containing insulating compounds have been characterized. The reactions of ammonia and hydrazine with silicon and gallium arsenide surfaces have been studied. Amorphous silicon nitride was grown through cyclic dosing and thermal decomposition of ammonia or hydrazine on the Si(100)-(2x1) surface. Hydrazine was found to nitride the surface more efficiently than ammonia. On the GaAs(100)-c(8x2) surface, the adsorption process and decomposition mechanism for ammonia and hydrazine adsorption were studied using temperature programmed desorption (TPD), x-ray photoelectron spectroscopy (XPS), and high resolution electron energy loss spectroscopy (HREELS). For ammonia adsorption on the GaAs(100)-c(8x2) surface, decomposition to NH;Nitrogen containing insulating materials have been characterized by ultra-soft x-ray absorption spectroscopy (USXAS). The core level spectra for imidazole (IM), 4,5-dicyanoimidazole (DCIM), s-triazine (TZ), and hexacarbonitrile-triimidazo-triazine (HTT) above the carbon and nitrogen K edges are reported. The spectra show sensitivity to core level shifts, especially for IM at the nitrogen edge. Substitution of electron withdrawing groups, such as cyano groups, results in a loss of sensitivity to these core level shifts. Complex spectra, such as HTT, are interpreted using the spectra of smaller model compounds (IM, DCIM, TZ). Linear combinations of the model compound spectra can be used to simulate the spectra for HTT and make accurate structural predictions. The limitations of this "building block" approach to spectral modeling of large molecules with extended... |
