Surface treatment of stainless steel component for semiconductor manufacturing apparatus

摘要

A process for surface treatment which comprises mechanically polishing the surface of a stainless steel component with abrasive grains having particle diameters of 1-10 mu m to such an extent that the surface has a work-strained layer formed therein which is characterized by that X-ray diffraction by the (111) plane of austenitic iron gives the diffraction beams whose half-value width (2 theta ) is greater than 0.5 degree, and subsequently performing heat treatment in an atmosphere in which the partial pressure of oxygen is low, thereby forming an oxide film composed mainly of chromium oxide which has a thickness greater than 200 ANGSTROM and a surface roughness Rmax smaller than 1 mu m. The surface-treated stainless steel exhibits outstanding corrosion resistance to halogen gases such as Cl2, HCl, and F2. It has such a smooth surface that it hardly adsorbs moisture vapor and gases. Therefore, it is suitable for use as components of semiconductor manufacturing apparatus.