A New Mechanism for Stacking Fault Generation in Epitaxial Growth of Silicon in Ultra-High Vacuum

The homo-epitaxial growth of thick films of silicon, grown by sublimation in vacuo of about 10-10 torr, has been investigated by means of low-energy electron diffraction (LEED) and transmission electron microscopy. In films grown on (111), stacking faults appear at substrate temperatures below 600°C, and increase in density with further decrease in growth temperature. Their appearance is correlated with the development of a mixed Si(111)-5, Si(111)-7 surface structure in this temperature range. It is proposed that these faults are generated by a new mechanism, whereby their nucleation is attributed to the formation of Si(111)-5 domains on the initial Si(111)-7 substrate surface.