Hydrogen effect on solid phase epitaxy of Si on Si (0 0 1) surface

Solid phase epitaxy (SPE) of amorphous Si layers of several tens of monolayers on hydrogen-adsorbed Si (0 0 1) substrates was studied in situ by low-energy time-of-flight (TOF) Rutherford Backscattering (RBS)-channeling spectrometry using 25 keV hydrogen ions, and by reflection high energy electron diffraction (RHEED). The SPE has not occurred at all for heating to 600°C even in the case of less than 1 ML adsorption of hydrogen on the Si (0 0 1) surface. Although the SPE has occurred for heating to 700°C, polycrystalline, or {1 1 1} faceted surface were formed. We did not obtain pronounced differences between the effects of the hydrogen adsorption of more or of less than 1 ML on the SPE of Si on Si (0 0 1). In the case of high density hydrogen-containing amorphous Si on a Si (0 0 1) clean surface the SPE has occurred at 600°C, and a {1 1 1} faceted surface was observed. Hydrogen adsorption obstructs the SPE of Si on Si (0 0 1) even if the coverage is less than 1 ML. The rise of the SPE temperature of amorphous Si on a hydrogen-adsorbed Si (0 0 1) surface is attributed to the hydrogen adsorption on the surface.