| 摘要 |
A method for preventing a dimple in a shallow trench isolation process is provided to form a wet type profile having a round shape by performing a wet-etch process using CHF3 in a silicon nitride layer etch process. An oxide layer(12) and a silicon nitride layer(13) are sequentially stacked on a silicon substrate(11). A photoresist(14) is coated on an upper surface of the silicon nitride layer except for an STI(Shallow Trench Isolation) region. An STI pattern liner is formed in a narrow width on a center part of the STI region of the upper surface of the silicon nitride layer. The silicon nitride layer is etched by using the photoresist and the STI pattern liner as etch masks. An oxygen ashing process is performed to remove the STI pattern liner. An additional SiN etch process is performed to form residues by removing a part of a SiN liner as the residual silicon nitride in a lower side of the removed STI pattern liner. A trench having a protrusion is formed in the STI region by etching the oxide layer and the silicon substrate.
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