METHOD FOR FORMING A RECESS GATE ELECTRODE

摘要

A method for forming a recess gate electrode is provided to simplify the process by using a photo resist pattern as an etch mask. A pad oxide film is formed on a substrate(100) having a doping region to prevent an out diffusion of impurities. A photo resist pattern is formed on the pad oxide film. The pad oxide film and the substrate are etched by using the photo resist pattern as an etch mask to form a gate trench(118). The gate trench is filled to form a gate electrode, which protrudes on the substrate. A mask pattern is formed on the substrate to expose a field region. The exposed substrate is etched by using the mask pattern as an etch mask to form a shallow trench isolation layer. An insulation film for device isolation is formed on the shallow trench isolation layer and the mask pattern to fill the shallow trench isolation layer. The insulation film is pattern to expose an upper portion of the mask pattern. The mask pattern is removed. An ion implantation process is performed to form a doping region.