METHOD FOR MANUFACTURING CAPACITOR OF ANALOG SEMICONDUCTOR DEVICE USING POLYSILICON-INSULATOR-POLYSILICON STRUCTURE

摘要

PURPOSE: A method for manufacturing a capacitor of an analog semiconductor device is provided to simplify manufacturing process and to reduce manufacturing cost by using PIP(Polysilicon-Insulator-Polysilicon) structure. CONSTITUTION: A first trench is formed by etching a substrate using a mask pattern. A buried oxide layer is filled in the first trench. A second trench is formed by etching partially the buried oxide layer. A polysilicon layer is filled in the second trench. By etching the polysilicon layer and the buried oxide layer to expose the mask pattern, a field oxide layer is formed and a lower electrode is simultaneously formed to fill the field oxide layer. A dielectric film(18) is formed on the lower electrode. The mask pattern is removed. An upper electrode(19) is formed on the dielectric film and a gate is simultaneously formed.