| 摘要 |
PURPOSE: A method for forming an isolation layer of a semiconductor device is provided to improve an electrical characteristic and enhance the reliability by burying fully the trench after a process for forming the trench. CONSTITUTION: A pad oxide layer and a first nitride layer are formed on a semiconductor substrate(21). A trench is formed by performing a photo etch process using an isolation mask. A second oxide layer(33), a second nitride layer(31), and a third oxide layer(35) are deposited on the entire surface of the semiconductor substrate including the trench. A spacer is formed on a sidewall of the trench by etching the third oxide layer, the second nitride layer, and the second oxide layer. An epitaxial layer(37) is formed on the exposed semiconductor substrate between the spacers in order to bury a bottom side of the trench. The fourth oxide layer(39) and the third nitride layer(41) are formed on a surface of the epitaxial layer. A trench type isolation layer is formed by depositing a fifth oxide layer(43) on a top side of the trench. The junction capacitance is reduced by implanting high-density ions into the epitaxial layer.
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