Thermal and radiation effects on Si-Si, Ge-Ge and Si-Ge bonds

Alberto Florentino Aguilera Alvarado, University of Texas at El Paso

Abstract

The Si-Si, Ge-Ge, Si-Ge, Si-H, and Ge-H bonds are analyzed through $\rm Si\sb2H\sb6$ and $\rm Ge\sb2H\sb6$ exposure onto a Si(100) surface at ultra-high vacuum conditions, and low temperature, 90 K. The tools used to interpret the results were: Temperature Programmed Desorption (TPD), Electron Stimulated Desorption (ESD), and Reaction Kinetic Modeling (RKM). A description of the adsorption mechanism for the two precursors is given. Interpretation of hydrogen desorption during TPDs and ESD experiments becomes the medium to explain the formation and scission of (Ge-, Si-, H-) bonds. Digermane-covered Si(100) surfaces exposed to electron-irradiation resulted in enhanced Ge deposition produced from molecularly-adsorbed $\rm Ge\sb2H\sb6$ dissociation. The total removal cross-section for digermane adsorbed on Si(100) by ESD experiments was obtained, with and without physically adsorbed digermane. The order of reactions for H$\sb2$ desorption from silicon and germanium hydride phases on the Si(100) surface were investigated, proving to be different than those obtained from H$\sb2$ on Si(100). A new mechanistic H$\sb2$ desorption channel from a $\rm Ge\sb2H\sb6$-exposed Si(100) surface is proposed, disclosed by (RKM). A successful thermal procedure has been implemented to desorb Ge adatoms from the Si surface. ^

Subject Area

Physics, Condensed Matter|Chemistry, Radiation|Engineering, Materials Science

Recommended Citation

Aguilera Alvarado, Alberto Florentino, "Thermal and radiation effects on Si-Si, Ge-Ge and Si-Ge bonds" (1997). ETD Collection for University of Texas, El Paso. AAI9819582.
http://digitalcommons.utep.edu/dissertations/AAI9819582

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