METHOD FOR FORMING STORAGENODE CONTACT PLUG IN SEMICONDUCTOR DEVICE

摘要

A method for forming a storage node contact plug of a semiconductor device is provided to guarantee an overlap margin with a storage node by depositing polysilicon once and performing a blanket etch process. An interlayer dielectric is formed on a semiconductor substrate(21). The interlayer dielectric is partially etched to form a first hole with a wider width. A mask pattern narrower than the first hole is formed on the first hole. The residual interlayer dielectric is etched by using the mask pattern to form a second hole narrower than the first hole. The mask pattern is removed. A spacer is formed on the sidewall of a storage node contact hole composed of the first and second holes. A storage node contact plug is formed in the storage node contact hole. The process for forming the mask pattern can include the following step. A hard mask is formed on the first hole. A photoresist layer pattern is formed on the hard mask by using a photoresist layer, patterned to be narrower than the first hole. The hard mask is etched by using the photoresist layer pattern as an etch barrier.