In-situ high-resolution electron microscopy study on a surface reconstruction of Au-deposited Si at very high temperatures

In-situ high-temperature high-resolution electron microscopy was applied to st study of the surface modification of Au-deposited Si. The experiment was carried out above the melting points of small particles of Au (approximately several nanometres in diameter) in a 300 kV high-resolution analytical transmission electron microscope equipped with a direct-heating-type specimen-heating holder in a vacuum of 4-6 x 10(-6) Pa. Facet-unfacet transformation and reconstruction of the Si{111}, {001}, {211} and {311} surfaces induced by wetting of molten Au atoms have been observed at near-atomic resolution. It is concluded that molten Au atoms remove a surface amorphous layer on the Si surface, making the surface clean even in a non ultra-high vacuum.