Nickel Induced Defects and their Role in Governing Chlorine Chemistry on the Si(100) Surface.
PITTSBURGH UNIV PA SURFACE SCIENCE CENTER
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The effect on chlorine surface chemistry of surface defects split-off dimers induced by controlled nickel contamination of Si100 surfaces has been studied. It is shown that the mechanism of chlorine surface etching changes significantly with the presence of a small amount of split-off dimer defects 0.02 monolayer. A new defect-related low temperature SiCl2 desorption channel is observed at approx. 550K and the kinetics of the major SiCl2 desorption channel at approx. 950K are changed. The presence of the low temperature SiCl2 desorption is attributed to the existence of SiCl2 surface species on the split-off dimer defects. The chlorine saturation coverage increases by up to approx. 10 in the studied range of defect densities. It is estimated that each split-off dimer defect contains 4.3 plus or minus 0.6 extra chlorine atoms compared to the ideal chlorine-saturated Si100 surface. On non-defective Cl-dosed Si100 surfaces, the electron stimulated desorption ion angular distribution ESDIAD images show only four off-normal Cl beams. With increasing defect density a new Cl beam develops in the normal 100 direction. This feature is associated with the Cl bonding on the split-off dimer defects, and is similar to that produced on Si100 surface containing point defects created in other ways.
- Inorganic Chemistry
- Physical Chemistry
- Polymer Chemistry
- Laminates and Composite Materials
- Properties of Metals and Alloys