| 摘要 |
PURPOSE: A method for manufacturing a semiconductor device is provided to control a moat by forming a trench-type isolation layer after a gate oxide layer, a polysilicon layer and a nitride layer are formed, and to guarantee a process margin by adding one process to a conventional process for forming the trench-type isolation layer. CONSTITUTION: The gate oxide layer(22), the polysilicon layer(23) and the nitride layer(24) are sequentially formed on a semiconductor substrate(21). A photoresist layer pattern is formed on the nitride layer, and the nitride layer, the polysilicon layer and the gate oxide layer are selectively removed by using the photoresist layer pattern as a mask. A predetermined depth of the semiconductor substrate is etched to form a trench(20). After a sacrificial oxide layer is formed in the trench and removed, a sidewall oxide layer(26) is formed. An oxide layer is formed to fill the trench. The oxide layer is polished, and the exposed nitride layer is eliminated by a polishing process. The oxide layer is etched by a cleaning process, and a conductive layer is formed and patterned on the resultant structure to form a gate.
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