Fabrication method for semiconductor integrated circuit device

A method for fabricating a semiconductor integrated circuit device comprising the steps of:

• (a) forming a groove in an element isolation region over a main surface of a wafer by etching said element isolation region over the main surface of the wafer by use, as a mask, of an oxidation-resistant insulating film formed over the main surface of said water;
• (b) forming a silicon oxide insulating film over the main surface of said wafer including the inside of the groove;
• and
• (c) subjecting said silicon oxide insulating film to chemical mechanical polishing through said oxidation-resistant insulating film as a stopper for polishing so that said silicon oxide insulating film is selectively left inside the groove thereby forming a polished, planarized insulating film isolation groove in said element isolation region on the main surface of said wafer,
• wherein when said silicon oxide insulating film is subjected to chemical mechanical polishing, a polishing slurry obtained after allowing to stand until a concentration of coagulated particles having a size of 1 μm or over is at 200,000 particles/0.5 cc of the slurry or below is used.

A method for fabricating a semiconductor integrated circuit device comprising the steps of:

• (a) forming a groove in an element isolation region over a main surface of a wafer by etching said element isolation region over the main surface of said wafer by use, as a mask, of an oxidation-resistant insulating film formed over the main surface of said water;
• (b) forming a silicon oxide insulating film over the main surface of said wafer including the inside of said groove;
• and
• (c) subjecting said silicon oxide insulating film to chemical mechanical polishing through said oxidation-resistant insulating film as a stopper for polishing so that said silicon oxide insulating film is selectively left inside the groove thereby forming a polished, planarized insulating film isolation groove in said element isolation region over the main surface of said wafer,
• wherein when the silicon oxide insulating film is subjected to chemical mechanical polishing, a polishing slurry obtained after allowing to stand for 30 days or over is used.