METHOD FOR FABRICATING SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method for fabricating a semiconductor device is provided to increase a contact area between an upper plug and a lower plug by making the upper portion of the lower plug have a round type, and to improve reliability of an interconnection by reducing a stack error and a void. CONSTITUTION: The first interlayer dielectric(22) is formed on a semiconductor substrate(21). The first interlayer dielectric is selectively removed to expose a predetermined region of the semiconductor substrate so that the first contact hole is formed. The first contact hole is filled with a conductive material to form the first plug(23). The second interlayer dielectric(24) is deposited on the semiconductor substrate. The second interlayer dielectric is selectively eliminated to expose the first plug so that the second contact hole is formed. The upper portion of the exposed first plug is rounded. The second contact hole is filled with a conductive material to form the second plug(27).