| abstract |
The ruthenium-containing metal 6 'adhered to the periphery of the device formation region, the end surface and the back surface of the silicon substrate 10 includes (a) a salt including chlorate, perchlorate, iodide, and iodide salt and bromine oxide; At least one compound selected from the group consisting of one salt, a salt containing manganese oxide and a salt containing tetravalent cerium ion, and (b) at least one acid selected from the group consisting of nitric acid, acetic acid, iodic acid and chloric acid It is removed using a first removal liquid containing. After the removal treatment, the substrate is washed with hydrofluoric acid to remove the remaining removal liquid. |