Microstructure and electrical properties of Sn nanocrystals in thin, thermally grown SiO2 layers formed via low energy ion implantation

We have developed a simple technique for fabricating Sn nanocrystals in thin thermally grown SiO2 layers using low energy ion implantation followed by thermal annealing. The formed Sn nanocrystals have excellent size and depth uniformity. Their average diameter is 4.2 nm with a standard deviation of 1.0 nm. Our experimental results clearly reveal that a stable depth of Sn exists in the SiO2 layer at about 2 nm from the SiQ(2)/Si interface. Most of the Sn nanocrystals reside near this stable depth. The I-V characteristics, of the diode structure show a clear Coulomb blockade region of 0.12 V and a Coulomb staircase at 4.2 K. A Coulomb blockade region around 0 V was observed until reaching a temperature of 77 K. The features of these nanocrystals will open up new possibilities for the creation of novel devices. (C) 1998 American Institute of Physics.