Evaluation of stress induced defects due to recessed LOCOS process

Defects induced during recessed LOGOS process for deep submicron isolation were investigated. L/S (Line and Space) patterns, which consisted of variou s SiO2 and Si3N4 widths, were designed to evaluate the defect density. Defe cts were observed as etch pits after Wright etching. Numerical simulation w as utilized for the stress evaluation. We confirmed that the defect density varied with changing recessed depth, Si3N4 width and field SiO2 width. The mechanism of the defect generation in relation to the recessed depth, the Si3N4 width and the field SiO2 width was successfully interpreted utilizing a process simulator.