METHOD FOR MANUFACTURING BURIED GATE IN SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method for manufacturing a buried gate of a semiconductor device is provided to prevent a pinhole of a pad poly silicon layer by forming a hard mask layer through the laminate of a low pressure nitrification layer and a plasma nitrification layer. CONSTITUTION: A pad oxide film(22) and a pad poly silicon film(23) are formed on a substrate(21). A trench(24) is formed by etching the substrate using the pad poly silicon film as an etch barrier. A first hard mask layer and a second hard mask layer are successively formed on the front of the substrate. A buried gate trench(29) is formed by etching the substrate with a preset depth. A gate insulation layer(30) is formed on the surface of the buried gate trench.