Abstract: A method for making a tungsten plug of a semiconductor device is disclosed.The method comprises the steps of: applying an etching process to a predetermined region of an insulating film formed a conductive layer to form a contact hole, said conductive layer being exposed at the predetermined region; adding a reactive gas containing tungsten metal ions into hydrogen radical plasma to form a tungsten thin film over said insulating film and said exposed conductive layer, said tungsten thin film having a good adhesiveness to said insulating film and a very thin thickness; depositing a blanket tungsten thin film in a predetermined thickness on the resulting structure; applying an etching process to said blanket tungsten thin film and subsequently to said tungsten thin film to expose the upper surface of said insulating film.The tungsten plug formed in accordance with the present invention contains no key holes therein since the tungsten thin film is formed in a uniform thickness.