MANUFACTURING METHOD OF SEMICONDUCTOR DEVICE

摘要

A method for fabricating a semiconductor device is provided to guarantee the margin of a CMP process by forming a planarization stop layer using a silicon nitride layer in a trench oxide layer region with a step in an STI process using reverse patterning. An oxide layer(202) and a plurality of first photoresist patterns separated from each other by a predetermined interval are formed on a semiconductor substrate(201). The oxide layer and the substrate are selectively etched to form a plurality of trenches by using the first photoresist pattern as an etch mask. A trench oxide layer(205) is filled in the trench. A planarization stop layer is formed on the trench oxide layer. A second photoresist pattern is formed on the planarization stop layer. The planarization stop layer is selectively etched by using the second photoresist pattern as an etch mask. The trench oxide layer is planarized by an etch-back process or a CMP process while the selectively etched planarization stop layer is removed. An ARC(anti-reflective coating) is formed on the planarized trench oxide layer. A plurality of third photoresist patterns are formed on the ARC. The ARC and the trench oxide layer are selectively etched to form an STI by using the third photoresist pattern as an etch mask.