IMPROVEMENT OF THE MORPHOLOGICAL QUALITY OF THE SI SURFACE USING AN OPTIMIZED IN-SITU OXIDE REMOVAL PROCEDURE PRIOR TO MBE GROWTH

In-situ Si beam-assisted thermal desorption of the native SiO2 layer h as been used for the cleaning of 100 mm (100) as-received Si substrate s in a VG Semicon V80 System. Optimising the Si beam-assisted thermal desorption technique by the help of atomic force measurements (AFM) an d mass spectrometer measurements has improved the surface morphology. It has been found that roughening of the substrate surface can be avoi ded 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.