| 摘要 |
PURPOSE: A method for forming a contact of a semiconductor device is provided to reduce an undesirable oxide erosion during a chemical mechanical polishing process. CONSTITUTION: First, an interlayer dielectric is formed on a semiconductor substrate and an anti reflection coating(ARC) layer of SiON is then deposited thereon. Second, a trench and a contact are formed into a predetermined pattern in the interlayer dielectric by photolithography. Then, a barrier metal and desired metal layers are deposited over a top surface. Next, a chemical mechanical polishing(CMP) is performed to remove the metal layer up to the ARC layer, and the substrate is then cleaned. In particular, since the ARC layer has a high selectivity to the metal layer, the ARC layer acts as effectual polishing stopper while reducing oxide erosion. Furthermore, it is desirable that the ARC layer is deposited thickly within a tolerance limit of an exposure step. Preferably, the ARC layer has a thickness of 700 to 100 angstroms.
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