METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method for manufacturing a semiconductor device is provided to optimize a characteristic of a transistor by performing an ion implantation process using an ion energy. CONSTITUTION: An N channel transistor is formed on a cell transistor formation region and a peripheral region of a semiconductor substrate(11). A gate electrode is formed on a buried P-channel transistor formation region. The first n-LDD region(23) is formed by implanting n-dopant ions on the whole surface. A pad oxide layer is formed on the whole structure. A photoresist pattern(27) is formed on an upper portion of the pad oxide layer. The second n-LDD region(28) is formed by implanting n-dopant ions on the first n-LDD region(23). The photoresist pattern(27) is removed. A pad nitride layer is formed on the whole structure.