Formation of Sn nanocrystals in thin SiO2 film using low-energy ion implantation

This letter reports on a simple technique for fabricating Sn nanocrystals in thin SiO2 film using low-energy ion implantation followed by thermal annealing. These Sn nanocrystals have excellent size uniformity and position controllability. Their average diameter is 4.8 nm with a standard deviation of 1.0 nm. Most of the Sn nanocrystals reside at the same depth. The lateral edge-to-edge spacing between neighboring Sn nanocrystals is fairly constant: about 3 nm. A narrow as-implanted ion distribution profile and the effect of the SiO2–Si interface are considered to contribute to the size uniformity and position controllability. The features of these nanocrystals will open up new possibilities for novel devices.