| 摘要 |
PURPOSE: A method for forming an isolation layer is provided to prevent a bridge caused by a conductive material on an isolation oxide layer and a dislocation in forming the isolation oxide layer made of a spin-on-glass(SOG) layer, by filling a trench of a shallow trench isolation(STI) structure having an aspect ratio of 3.5:1 or greater. CONSTITUTION: The first pad layer is formed on a substrate(31) where an isolation region is defined. The first pad layer and the substrate in the isolation region is selectively etched to form a plurality of the first trenches and a plurality of the second trenches having a narrow width of 50-0.2 micrometer. The second pad layer is formed on the entire surface including the first and second trenches. A predetermined thickness of the isolation layer higher than the surface of the substrate is formed on the second pad layer until before the void closed in the second trench is generated. The isolation layer on an active region in the periphery of the first trench is selectively eliminated. An insulation layer is formed on the isolation layer. The insulation layer is removed by an etch-back process using the first pad layer as an etch end point, and the isolation layer is planarized. The first pad layer is eliminated.
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