OBSERVATION OF ELECTROMIGRATION EFFECT UPON SI-MBE GROWTH ON SI(001) SURFACE

Si(001) surface topography changes during annealing, and Si molecular beam epitaxial (MBE) growth is observed by reflection electron microscopy using microprobe reflection high-energy electron diffraction. When the sample is heated above 600°C, one of the monoatomic steps to which the 2 × 1 dimer axis is normal or parallel becomes less stable than the other, depending on the direction of the sample electric current used for heating. Si atoms are detached from the unstable steps and captured by the stable steps. This causes selective growth of one of the two 2 × 1 domains on the surface and biatomic step growth during Si MBE at high substrate temperature (∼900°C). © 1990.