| 摘要 |
PURPOSE: A method for forming a device isolation layer of a semiconductor device is provided to use a nitride spacer in order to cause selective epitaxial growth. CONSTITUTION: A method for forming a device isolation layer of a semiconductor device according to the present invention includes following steps. At the first step, a pad oxide layer(20), a first nitride layer(30), and an oxide layer(50) are vaporized on a semiconductor substrate(10). At the second step, a trench(40) is formed by etching the portion on which a device isolation layer(65) is to be formed by using a field mask. At the third step, a spacer(75) is formed in the trench by vaporizing a second nitride layer(70) on the trench and etching the second nitride layer. At the fourth step, a gap fill oxide(60) is vaporized on the surface of the trench, and the result is flattened so as to expose the first nitride layer. At the fifth step, the first nitride and the pad oxide are removed. At the sixth step, an epitaxial silicon layer is formed by selectively growing the pad oxide to the depth of the gap fill oxide.
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