Si(001):B gas-source molecular-beam epitaxy: Boron surface segregation and its effect on film growth kinetics

H. Kim, G. Glass, T. Spila, N. Taylor, S. Y. Park, John R Abelson, J. E. Greene

Research output: Contribution to journalArticle

Abstract

B-doped Si(001) films, with concentrations C B up to 1.7 × 10 22 cm -3 , were grown by gas-source molecular-beam epitaxy from Si 2 H 6 and B 2 H 6 at T s = 500-800°C. D 2 temperature-programed desorption (TPD) spectra were then used to determine B coverages θ B as a function of C B and T s . In these measurements, as-deposited films were flash heated to desorb surface hydrogen, cooled, and exposed to atomic deuterium until saturation coverage. Strong B surface segregation was observed with surface-to-bulk B concentration ratios ranging up to 1200. TPD spectra exhibited β 2 and β 1 peaks associated with dideuteride and monodeuteride desorption as well as lower-temperature B-induced peaks β* 2 and β* 1 . Increasing θ B increased the area under β* 2 and β* 1 at the expense of β 2 and β 1 and decreased the total D coverage θ D . The TPD results were used to determine the B segregation enthalpy, -0.53 eV, and to explain and model the effects of high B coverages on Si(001) growth kinetics. Film deposition rates R increase by ≥50% with increasing C B ≳1 × 10 19 cm -3 at T s ≤550°C, due primarily to increased H desorption rates from B-backbonded Si adatoms, and decrease by corresponding amounts at T s ≥600°C due to decreased adsorption site densities. At T s ≥700°C, high B coverages also induce {113} facetting.

Original languageEnglish (US)
Pages (from-to)2288-2297
Number of pages10
JournalJournal of Applied Physics
Volume82
Issue number5
DOIs
StatePublished - Sep 1 1997

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Fingerprint Dive into the research topics of 'Si(001):B gas-source molecular-beam epitaxy: Boron surface segregation and its effect on film growth kinetics'. Together they form a unique fingerprint.

  • Cite this