| 摘要 |
PURPOSE: A method for manufacturing semiconductor device having buried bit line structures is provided to improve a refresh characteristic by increasing capacitance by using a bit line formed in trenches. CONSTITUTION: A first trench is formed by sequentially forming an oxide layer, a nitride layer on a semiconductor substrate(100) and then selectively removing the nitride layer, oxide layer and the semiconductor substrate. A conductive layer(110a) is formed in the first trench, and an upper portion of the conductive layer is removed. A planarized dielectric layer(112) is formed in the first trench, and an upper portion of the nitride layer is exposed by polishing the planarized dielectric layer. The second trench is formed on the substrate and an isolation layer is formed in the second trench. The nitride layer is exposed and removed. A gate line and a hard mask layer(126) are sequentially formed on an active region on the insulating layer(118a). A source/drain region(127) is formed in the substrate. A conductive layer for plug is formed in a contact hole exposing the source/drain region and the conductive layer. A lower electrode layer, a dielectric layer, and an upper electrode layer are formed to complete a capacitor.
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