A QUANTITATIVE STUDY OF ELECTRON -STIMULATED- DESORPTION SPECTROSCOPY USING A LIGHT EXCITATION

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The system of time-of-flight type electron-stimulated desorption (TOF-ESD) spectroscopy is very useful to detect hydrogen on solid surfaces in spite of its simple construction. However, a quantitative analysis is still controversial due to high renutralization of desorbedions depending on species and surface conditions. Therefore, in order to establish a quantitative analysis, it is necessary to calibrate for the ESD signal intensity to amounts of adsorbate.Though a post ionization method by for desorbed particles using a laser beam had been planned originally, it was abandoned to set up in this project due to a squeezed budget. Conquering this, we have tried to compare the ESD yield from adsorbates to absorbance of infrared light by vibration intensity of molecules by using a Fuorie-Transform Infrared Spectroscopy (FTIR). An in-situ measurement of ESD and FTIR have been firstly constructed here. An experiment for CO on metals revealed good relationship. However, in the case of H on Si, a signal intensity of a FTIR was too small to calibrate adsorption amounts. We have compromised to calibrate for adsorbed hydrogen on silicon surface by the result of E1astic Recoil Detection Analysis (ERDA) comparing with a TDS result. As applications of TOF-ESD,hydrogen mediated heteroepitaxy and a two dimensional hydrogen analysis have been accomplished.