METHOD FOR FORMING CONTACT PLUG TO REDUCE DEPTH OF CONTACT HOLE FOR INTERCONNECTING METAL INTERCONNECTION AND CONDUCTIVE LAYER

摘要

PURPOSE: A method for forming a contact plug is provided to reduce the depth of a contact hole for interconnecting a metal interconnection and a conductive layer by previously forming a contact plug in the same level as a capacitor. CONSTITUTION: An oxide layer for a storage node is formed on a substrate having a predetermined underlying structure. The oxide layer is selectively etched to define a capacitor region. The storage node is formed in the capacitor region. A high dielectric layer is formed on the storage node. An upper electrode is formed on the high dielectric layer. The oxide layer is selectively etched to form the first metal contact hole exposing the predetermined underlying structure of the substrate. A barrier metal and a metal plug material are sequentially deposited on the substrate including the upper electrode and the first metal contact hole so as to fill the first metal contact hole. The upper electrode is patterned to be a predetermined pattern while a metal contact plug is formed in the first metal contact hole. An interlayer dielectric is formed on the front surface of the substrate. The interlayer dielectric is selectively etched to form the second metal contact hole in a predetermined region. A barrier metal and a metal plug material are sequentially deposited on the substrate including the second metal contact hole. The metal plug material and the barrier metal are etched back to form a metal plug(20) filled in the second metal contact hole.