B DOPING EFFECT ON REFLECTION HIGH-ENERGY ELECTRON-DIFFRACTION INTENSITY OSCILLATION DURING GAS SOURCE SILICON MOLECULAR-BEAM EPITAXIAL-GROWTH

B doping effect on reflection high-energy electron diffraction (RHEED) intensity oscillation was studied during gas source Si molecular beam epitaxial growth. During high doping of B above 1020 cm-3, no RHEED oscillation was observed on Si (100) surfaces. This is caused by surface B atoms which disturb surface migration of disilane (Si2H6) molecules. On the other hand, RHEED oscillation was observed on Si (111) √3×√3 B surfaces. At √3×√3 B surfaces, B exists in a subsurface substitutional site, directly underneath a Si adatom. This is the reason why surface migration was not disturbed by surface B atoms on Si (111) √3×√3 B surfaces.