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Abstract: The intensities of the optical spectral lines emitted from a Ge(100) surface under Ar+ ion bombardment are studied as a function of the ion kinetic energy (1–5keV) and the partial pressure (5×10−6–5×10−4 Torr) of either germane or silane. For germane exposures, the Ge (GeI, 265nm and 304nm), H Balmer beta (486nm) and H Balmer gamma (434nm) optical lines are observed. For silane, additional peaks due to excited neutral Si (SiI, 288nm) and molecular SiH (A2Δ–X2Π, 414nm) are visible. The ion kinetic energy dependence of the GeI photon yields (265nm and 304nm) is analyzed in terms of the electron exchange mechanism. The similarity between the measured de-excitation parameters for germane and silane pressure between 5×10−6 and 5×10−4 Torr implies that the de-excitation mechanism does not change significantly. For both germane and silane exposures, the intensities of excited neutral Ge, H beta and H gamma optical lines increase with either larger partial pressures or ion kinetic energy. A similar trend is found for neutral SiI and molecular SiH emission during silane exposures. In contrast, the intensity of the H Balmer alpha transition (656nm) decreases with increasing incident ion kinetic energy at all measured partial pressures. Both trends are similar to that observed for either silane or germane exposed Si(100) surfaces under ion bombardment. [Copyright &y& Elsevier]

Abstract: The intensities of the optical spectral lines emitted from a Si(100) surface under Ar+ ion bombardment are studied as a function of the ion kinetic energy (1–5keV) and the partial pressure of germane. In these experiments, the ion flux is held constant while either the bombardment energy or the partial pressure of germane is varied. The excited neutral Si (SiI, 288nm), neutral Ge (GeI, 265nm and 304nm), H Balmer beta (486nm) and H Balmer gamma (434nm) optical lines are observed. With increasing germane partial pressure, a broad emission feature develops between 330 and 365nm and is assigned to excited GeH2 and/or GeH3 species. The emission intensities of the excited neutral Si, neutral Ge, Hβ and Hγ optical lines from the bombarded Si(100) surface increase with greater germane partial pressures and ion kinetic energy in a manner similar to that previously observed for silane exposures. In contrast to the monotonic increase of the above emission lines with higher germane partial pressures and greater incident kinetic energies, the H Balmer alpha (656nm) optical line exhibits unique behavior. Paralleling the behavior observed for silane exposed surfaces, the intensity of the Balmer alpha transition decreases with increasing incident ion kinetic energy at all measured partial pressures of germane. [Copyright &y& Elsevier]