| 摘要 |
PURPOSE: A method for forming an isolation layer of a semiconductor device is provided to form stably an isolation layer without the generation of moat by etching only a silicon layer without etching a linear nitride layer, a linear oxide layer, and a thermal oxide layer. CONSTITUTION: A pad oxide layer(22), a silicon layer, and a pad nitride layer are formed on a semiconductor substrate(21). The semiconductor substrate of an isolation region is exposed by patterning the pad nitride layer, the silicon layer, and the pad oxide layer. A trench is formed by etching the exposed part of the substrate. A sacrificial oxidation process is performed to remove a sacrificial oxide layer from a surface of the trench and a lateral part of the silicon layer. A thermal oxide layer(26) is formed on the surface of the trench and the lateral part of the silicon layer. A linear nitride layer(27) and a linear oxide layer are formed thereon. A buried oxide layer is formed on the linear oxide layer. A CMP process for the buried oxide layer is performed. The pad nitride layer is removed therefrom. The silicon layer is removed by a wet-etch process using chemicals.
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