Surface Reactions in the Decomposition of Zinc Alkyls on Si(100)-2×1 Surfaces

1990 ◽  
Vol 204 ◽  
Author(s):  
M.A. Rueter ◽  
J.M. Vohs
Keyword(s):  
High Resolution ◽  
Surface Reactions ◽  
Temperature Programmed Desorption ◽  
Silicon Surfaces ◽  
Methyl Groups ◽  
Methyl Radicals ◽  
Resolution Electron ◽  
Temperature Programmed ◽  
Electron Energy Loss ◽  
Insight Into

ABSTRACTThe adsorption and reaction of dimethylzinc and diethylzinc on Si(100)-2×l surfaces was studied using temperature programmed desorption and high resolution electron energy loss spectroscopy. These zinc alkyls were found to dissociate at temperatures less than 300 K to produce adsorbed alkyl species and deposit zinc on the surface. During temperature programmed desorption zinc metal desorbed at 530 K leaving only alkyl species on the surface at higher temperatures. Surface methyl groups were found to decompose to carbon and hydrogen or desorb as methyl radicals, while surface ethyl groups underwent a series of surface reactions which resulted in three separate ethylene desorption peaks. The results of this study provide new insight into the reactions of group II metal alkyls on silicon surfaces.

Xps, Ups, and Hreels Studies of Excimer-Laser-Induced Dissociation of Al2(Ch3) Adsorbed on Si(100) Surfaces

1987 ◽  
Vol 101 ◽  
Author(s):  
D. Lubben ◽  
T. Motooka ◽  
J.E. Greene ◽  
J.F. Wendelken ◽  
J.-E. Sundgren ◽  
...  
Keyword(s):  
High Resolution ◽  
Energy Loss ◽  
Fermi Level ◽  
Laser Irradiation ◽  
Methyl Groups ◽  
Molecular Orbital Calculations ◽  
X Ray ◽  
Resolution Electron ◽  
193 Nm ◽  
Electron Energy Loss

ABSTRACTArF (193 nm) and KrF (248 nm) laser-induced dissociation of Al2(CH3)6 (TMA) adsorbed on Si(100) surfaces have been investigated using x-ray photo-electron, ultraviolet photoelectron, and high-resolution electron energy loss spectroscopies (XPS, UPS, and HREELS). UPS and XPS valence spectra from the adlayer contained three broad peaks near 4.5, 7.5, and 14.5 eV below the Fermi level whose positions were in agreement, based upon molecular orbital calculations, with those expected for TMA dimers. Angle-resolved XPS measurements indicated a splitting in both the Al 2p and Si 2p levels which was interpreted as evidence for TMA dimer molecules being adsorbed with the long (i.e. Al-Al) axis perpendicular to the surface. The HREELS adlayer spectrum consisted of three clusters of peaks located near 86 meV (methyl rocking and Al-C stretch), 170 meV (methyl deformation), and 362 meV (C-H stretch). Changes in the XPS, UPS, and HREELS spectra were monitored as a function of ArF and KrF laser irradiation. No-changes were observed for KrF irradiation with intensities up to 200 mJ-cm . However, ArF laser irradiation resulted in changes in both the XPS and HREELS spectra which indicated TMA dissociation and the desorption of methyl groups. Nevertheless, even after 104 20 mJ-cm-2 ArF pulses most of the carbon-containing species remained. Higher intensities, up to 200 mJ-cm-2, resulted in the formation of compounds which were stable on the surface.

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