Semiconductor device manufacturing method

Abstract

A semiconductor device manufacturing method forms precision device isolation areas of a desirable minimum feature size in a semiconductor device having trench isolation areas. Steps include: (a) forming a polishing stopper layer 140 having a specific pattern on a semiconductor substrate 10; (b) forming trenches 16 in the semiconductor substrate 10 by etching using at least the polishing stopper layer 140 as a mask; (c) forming a protective layer 18 on the trench 16 surfaces; (d) causing the position of an edge part of the polishing stopper layer 14 to recede from the position of the trench 16 sidewalls; (e) forming an insulation layer 21 on the semiconductor substrate 10 so as to fill the trenches 16; and (f) forming trench isolation areas 30 by polishing the insulation layer 21 using the polishing stopper layer 14 as a stopper.

Dependencies are inferred from the claim text.