Method of forming conductive layer including removal of native oxide

A method for forming a gate electrode of a MOS type semiconductor device, comprising the steps of:

• forming a gate oxide film on a surface of a semiconductor substrate;
• forming a polycrystalline silicon layer on said gate oxide film;
• performing dry etching of said surface of said polycrystalline silicon layer in a first chamber maintained in a nonoxidizing atmosphere, using a gas mixture of an N.sub.2 gas and an NF.sub.3 gas, to remove a natural oxide from said surface of said polycrystalline silicon layer;
• transferring said substrate from said first chamber to a second chamber while the nonoxidizing atmosphere is maintained;
• forming a refractory metal layer on said surface of said polycrystalline silicon layer by low-pressure CVD in said second chamber;
• and
• patterning said polycrystalline silicon layer and said refractory metal layer to form a gate electrode consisting essentially of said polycrystalline silicon layer and said refractory metal layer.

A method for forming source and drain electrodes of a MOS type semiconductor device, comprising the steps of:

• forming a gate oxide film and a gate electrode on a surface of a semiconductor substrate;
• forming source and drain regions by doping an impurity in said semiconductor substrate;
• performing dry etching of surfaces of said source and drain regions in a first chamber maintained in a nonoxidizing atmosphere, using a gas mixture of an N.sub.2 gas and an NF.sub.3 gas, to remove a natural oxide from said surfaces of said source and drain regions;
• transferring said substrate from said first chamber to a second chamber while the nonoxidizing atmosphere is maintained;
• and
• depositing a refractory metal on said surfaces of said source and drain regions by low-pressure CVD in said second chamber.