Transformation of Cl Bonding Structures on Si(100)-(2x1)
Abstract
The digital electron stimulated desorption ion angular distribution (ESDIAD) method has been used to observe the existence and the irreversible thermal transformation between different bonding structures for Cl on the Si(100)(2xl) surface. The ESDIAD pattern produced from dissociative chemisorption of Cl2 at 120 K shows intense normal emission of Cl+, plus lower intensity of Cl+ emission focused along the 011 and (011) axes (the axes Of Si2 dimer orientations in two domains). Upon annealing to higher temperatures (T less than or equal to 673 K), the CL+-ESDIAD pattern is irreversibly transformed into a four-beam pattern with a two-fold azimuthal symmetry in the plane of each dimer axis, indicative of Si-Cl bonds inclined 25 deg + or - 4 deg from the surface normal. This irreversible thermal behavior indicates that the four-beam ESDIAD pattern represents the lower-energy bonding configuration for Cl on the si(100)-(2x1) surface. The broad temperature range (AT approx. 300 K) associated with the complete transformation suggests that a kinetic process, involving a constant activation energy and preexponential factor, is not appropriate for describing the structural conversion process.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 22, 1992
- Accession Number
- ADA253739
Entities
People
- C. C. Cheng
- J. T. Yates Jr.
- Qing Gao
- Wolfgang J. Wolfgang J. Choyke
Organizations
- University of Pittsburgh