Preparation of atomically clean and flat Si(1 0 0) surfaces by low-energy ion sputtering and low-temperature annealing

Si(1 0 0) surfaces were prepared by wet-chemical etching followed by 0.3–1.5 keV Ar ion sputtering, either at elevated or room temperature (RT). After a brief anneal under ultrahigh vacuum (UHV) conditions, the resulting surfaces were examined by scanning tunneling microscopy. We find that wet-chemical etching alone cannot produce a clean and flat Si(1 0 0) surface. However, subsequent 300 eV Ar ion sputtering at room temperature followed by a 700 °C anneal yields atomically clean and flat Si(1 0 0) surfaces suitable for nanoscale device fabrication.