| 摘要 |
PURPOSE: A method for manufacturing an STI(Shallow Trench Isolation) structure is provided to reduce the leakage current of the STI structure by inserting a PSG layer into a shallow trench. CONSTITUTION: A TEOS(Tetra Ethyl Ortho Silicate) layer(12) and a nitride layer(14) are sequentially formed on a substrate(10). A photoresist pattern is formed on the resultant structure. The nitride and TEOS layer are selectively removed by carrying out an etching process using the photoresist pattern as an etching mask. The photoresist pattern is removed from the resultant structure. A plurality of shallow trenches are formed by selectively etching the substrate using the etched nitride and TEOS layer as an etching mask. A first and a second liner(18,20), and a PSG layer(22) are sequentially formed along the upper surface of the resultant structure. Then, the trenches are completely filled with a USG layer. A planarization process is carried out on the resultant structure until the nitride layer is exposed.
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