Abstract: The present invention relates to a method for manufacturing a semiconductor device, comprising: forming a metal interconnect on a substrate; forming a refractory metal layer containing titanium (Ti) or tantalum (Ta) on a surface of the metal interconnect; forming an insulating interlayer so as to cover the refractory metal layer; selectively etching the insulating interlayer with an etchant gas containing an organic fluoride to form a hole, in which the refractory metal layer is exposed; treating an interior of the hole with an organic chemical solution to remove fluorinated compounds of Ti or Ta while leaving fluorocarbons on the surface of the refractory metal layer, the fluorinated compounds of Ti or Ta and the fluorocarbons being created during the etching step and present in the interior of the hole; and performing plasma-treatment for the interior of said hole to remove the fluorocarbon.