An observation of 650 °C deformation of Si surface under ultra high vacuum

Significant deformation of a grooved Si surface is discovered during low temperature processing (650–900 °C) in a ultra high vacuum. The lowest temperature at which deformation results is determined to be 650 °C for a (111)Si substrate. In addition, clear facets are formed after high temperature processing (850–900 °C). These new findings are tentatively considered to originate from the surface migration of Si atoms on atomically clean surfaces.