METHOD OF FORMING CONTACT PLUG AND PLANARIZATION OF INSULATOR LAYER OF SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method of forming a contact plug and a method of planarizing an insulating layer are to effect only one time CMP(chemical mechanical polishing) against an insulating layer and a conductive layer. CONSTITUTION: An insulating layer(16) is formed on the semiconductor substrate(10). The insulating layer comprises a cell area and a space area. The first interlayer dielectric(18) is formed on the insulating layer. By etching the first interlayer dielectric, the second interlayer dielectric(20) is formed on the semiconductor substrate. The second interlayer dielectric comprises a planarized upper surface. The second interlayer dielectric is etched to form a contact hole. By overfilling the contact hole, a conductive layer is formed on the semiconductor substrate. The conductive layer and the second interlayer dielectric are planarized to form a contact plug(26). The second interlayer dielectric is a doped glass layer.