Position and size controlled fabrication of nano-metals and -semiconductors with fine focused electron beam

Nanofabrication with tine focused electron beam was reviewed, and position and size controlled fabrication of nano-metals and -semiconductors are demonstrated. The nanowire of GaAs was shown to have an about 3 nm in diameter. We have discovered that Si nanocrystals with 2 to 3 nm can be formed in SiO₂ thin film under irradiation of an electron beam 4.10⁸ C/m² at 850K. An array of the Si nanocrystal dots was also fabricated using this method. Similarly, when decomposable gases such as W(CO)₆ were introduced at the beam irradiated areas, nano-metal islands are formed depending upon the beam diameter and the exposure time. The diameter of the dots was reduced to about 3.5 nm with the FE-STEM, while those were limited to about 15 nm in diameter with the FE-SEM. Self-standing structures were successfully fabricated.