| 摘要 |
PURPOSE: A method for fabricating an isolation layer of a semiconductor device is provided to improve an electric characteristic, by making a top corner portion of a trench round so that an electric field concentration is prevented. CONSTITUTION: A pad oxide layer(22) and a nitride layer are sequentially formed on a semiconductor substrate(21) where an active region and a field region are defined. The nitride layer and the pad oxide layer are selectively eliminated to expose the field region of the semiconductor substrate. The exposed semiconductor substrate is selectively removed to form a trench. An insulation layer is formed on the entire surface including the trench and is etched back to form an insulation layer sidewall(25) on both side surfaces of the trench. Impurity ions are implanted into the trench. The pad oxide layer is selectively removed from the side surface of the trench to form an empty space between the nitride layer adjacent to the trench and the semiconductor substrate while the top corner portion of the trench is etched and rounded. The isolation layer(28a) is formed inside the trench. The nitride layer is eliminated.
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