Improvement of the morphological quality of the Si surface using an optimised in-situ oxide removal procedure prior to MBE growth

In-situ Si beam-assisted thermal desorption of the native SiO2 layer has been used for the cleaning of 100 mm (100) as-received Si substrates in a VG Semicon V80 System. Optimising the Si beam-assisted thermal desorption technique by the help of atomic force measurements (AFM) and mass spectrometer measurements has improved the surface morphology. It has been found that roughening of the substrate surface can be avoided if the Si beam-assisted thermal desorption is stopped immediately after removal of the SiO2 layer. Subsequently, a 500 Angstrom thick Si layer can be grown without surface holes if the substrate temperature is lowered to 500 degrees C.