METHOD FOR MANUFACTURING ANALOG SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method for manufacturing an analog semiconductor device is provided to reduce the step difference between a transistor area and a capacitor area by forming a lower electrode of a capacitor in an active area. CONSTITUTION: Oxygen ions are implanted into a lower electrode area of a capacitor(400) formed in a semiconductor substrate(21). A high density impurity ions are implanted into the lower electrode area of the capacitor(400). An oxide layer(23a) is formed by heat-treating the semiconductor substrate(21). At the same time, a lower electrode(24a) of the capacitor(400) consisting of a high density impurity diffusing area is formed on the oxide layer(23a). Then, a transistor area and a capacitor area including the oxide layer(23a) and the lower electrode(24a) are defined in the active area of the semiconductor substrate(21) by forming a field oxide layer(25) on the semiconductor substrate(21). After forming an insulating layer, a gate material layer is formed thereon. Then, a dielectric layer(26b) and an upper electrode(300b) are formed on the lower electrode(24a), thereby forming the capacitor(400).