Si(001) layers doped with B concentrations CB ranging from 5 x 1016 to 2 x 1021 cm-3 were grown on Si(001)-(2 x 1) substrates by gas-source molecular beam epitaxy using Si2H6 and B2H6. B was incorporated into substitutional electrically active sites at concentrations up to 2.5 x 1020 cm-3. With increasing incident flux ratios JB2H6/JSi2H6≥0.01 (corresponding to CB = 2 x 1019 cm-3), film growth rates decreased at Ts≥600°C, but increased at Ts≤550°C. Deuterium temperature-programmed desorption measurements as a function of increasing CB show strong B surface segregation, decreased steady-state H coverages θH, and lower dangling bond densities. The Si:B growth kinetics are well described by a model showing that at low temperatures, where steady-state θH values are high, increased H desorption rates from B-backbonded Si adatoms dominate, leading to an enhancement in RSi, whereas at higher temperatures RSi decreases due to the decreased adsorption-site density.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Surfaces and Interfaces
- Surfaces, Coatings and Films
- Materials Chemistry