THERMAL-DESORPTION FROM SI(111) SURFACES WITH NATIVE OXIDES FORMED DURING CHEMICAL TREATMENTS

The thermal desorption process during thermal cleaning of Si(111) surfaces with native oxides formed by various chemical treatments is studied using TDS (thermal desorption spectroscopy) under UHV. The reaction product of the process is identified to be SiO. The surface cleanliness after the cleaning is virtually independent of the oxide formation method. However, the desorption temperature of SiO strongly depends on the method. This dependence cannot be explained purely by SiO diffusion in the oxide film. It suggests that the interface structure between an oxide layer and a Si substrate significantly affects the desorption temperature of native oxides. A scheme for removing oxide film is proposed. © 1990 The Japan Society of Applied Physics.