| abstract |
There is described a method of forming a semiconductor device in which a contact plug penetrates through an interlayer insulating film. The method is capable of formation of a multilayer wiring structure of small resistance. Contact holes are formed in an interlayer oxide film laid on a silicon substrate by etching, through use of a CF-based gas plasma. An organic layer deposited at the bottom of the contact holes is removed through cleaning etching through use of a plasma of a mixed gas consisting of CF 4 and O 2 . After removal of the organic layer, a conductive contact plug is formed in each of the contact holes. |