METHOD OF FORMING ALIGN KEY BY TRENCH ETCH

摘要

PURPOSE: A method for forming a align key is provided to improve decreasing of align reliability and occurring of errors by forming a trench. CONSTITUTION: The method comprises the steps of: forming a silicon oxide film for buffer layer; forming a photoresist film on the silicon oxide film; forming a silicon oxide pattern by photolithography; implanting dopants in a substrate surface including the silicon oxide pattern; and forming a trench used for align key by etching a exposed portion of the substrate.