Thermal desorption of surface phosphorus on Si(100) surfaces

Thermal desorption of phosphorus on Si(100) surfaces has been investigated by varying the phosphorus coverage from zero to one monolayer (ML). The rea ction path of phosphorus desorption is complicated and strongly dependent u pon the phosphorus coverage. In the thermal description spectra, there are three apparent desorption peaks at similar to 750, similar to 850 and simil ar to 1000 degrees C. The entire phosphorus atoms on the surface desorb as P-3 through recombinative reactions irrespective of the desorption temperat ure and the coverage. In the lower coverages below 0.2 ML, the thermal deso rption spectra are characterized by a single peak at similar to 900 degrees C which is considered to be the desorption from Si-P heterodimers. At high er coverages exceeding 0.2 ML, it is considered that three desorption schem es from P-P, Si-P dimers and defects coexist in the reaction stage. (C) 199 9 Elsevier Science B.V. All rights reserved.