| abstract |
(57) Abstract: A method for removing metal impurities present on a surface of a Si substrate covered with a SiO 2 film, and in particular, to remove metal contamination such as Pt, Ir, and Ru that hardly melts with a conventional cleaning solution. It is intended to be removed. With A HF or washing solution containing NH 4 F, by Si substrate or the underlying device region of the substrate to etch the SiO 2 film on the surface of the substrate so as not to expose the metal is removed with SiO 2 film And prevents redeposition of metal from the cleaning solution. |