Semiconductor device with tapered contact hole and wire groove

A method of manufacturing a semiconductor device, comprising the steps of:

• forming a transistor provided with a gate electrode on a semiconductor substrate, and a source/region region in the semiconductor substrate, adjacent to the gate electrode;
• depositing a first insulation film over the transistor;
• depositing a second insulation film on the first insulation film;
• forming an opening portion in the second insulation film;
• depositing a third interlayer insulation film on the second interlayer insulation film and a portion of the first insulation film exposed by the opening hole;
• and
• etching the third insulation film and the first insulation film to form a wire groove on the third insulation film while the second insulation film is hardly etched, and to form in the first insulation film a contact hole leading to the gate electrode or the source/drain region of the transistor with a substantial taper angle at a portion of a side wall of the contact hole while an edge portion of the opening portion exposed during the etching process is gradually removed, using an anisotropic selective etching technique having a slightly lower etching selectivity.

A method of manufacturing a semiconductor device comprising the steps of:

• forming an opening hole in an insulation film;
• depositing a first refractory metal film in the opening hole;
• nitrifying a surface of the first refractory metal film;
• depositing a second refractory metal film on a nitrified surface of the first refractory metal film;
• and
• changing the second refractory metal film to a nitride film by a thermal treatment.

A method of manufacturing a semiconductor device comprising the steps of:

• forming an opening hole in an insulating film;
• depositing a first refractory metal film in the opening hole;
• depositing a refractory metal nitride film on a surface of the first refractory metal film;
• depositing a second refractory metal film on a surface of the refractory metal nitride film;
• and
• changing the second refractory metal film to a nitride film by heat treatment.