METHOD FOR FORMING METAL LINE CONTACT PLUG OF SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method for forming a metal line contact plug of a semiconductor device is provided to be capable of easily isolating contact plugs and improving process stability by using two-step CMP processing. CONSTITUTION: Bit lines(103) stacked on a mask insulating pattern(105) are formed on a semiconductor substrate(101). After forming an interlayer dielectric on the resultant structure, contact holes are formed by selectively etching the interlayer dielectric. An insulating spacer is formed at both sidewalls of the contact holes and the bit lines. A metal film is then formed on the resultant structure. Contact plugs(113b) are formed by using two-step CMP(Chemical Mechanical Polishing). That is, the first CMP processing is performed using the first slurry, wherein the polishing selectivity of the metal film and the insulating layer is over 10. The second CMP processing is performed using the second slurry, wherein the polishing selectivity of the metal film and the insulating layer is below 3.