| 摘要 |
PURPOSE: A method for eliminating a particle source in a shallow trench isolation(STI) process is provided to prevent a product defect, by eliminating a device defect material generated in a region having a small pattern in an etch process for planarization. CONSTITUTION: A silicon oxide layer(112) is formed on a semiconductor substrate(110). A silicon nitride layer(114) is deposited on the silicon oxide layer. An anti-reflecting coating(ARC) layer is applied on the silicon nitride layer. The ARC layer, the silicon nitride layer, the silicon oxide layer and the semiconductor substrate are etched to form a trench(119) in the semiconductor substrate by a photolithography process. An insulating layer is deposited on the entire surface of the semiconductor substrate to fill the trench. The insulating layer is etched for planarization by a chemical mechanical polishing(CMP) process until the silicon nitride layer is exposed, to form a trench isolation layer(120a). The trench isolation layer is further etched so that the height of the trench isolation layer is lower than the upper surface of the semiconductor substrate. The silicon nitride layer and the silicon oxide layer are eliminated.
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