METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE

摘要

A method for fabricating a semiconductor device is provided to prevent process uniformity in a subsequent etch(patterning) process from being decreased by a step between a field region and an active region in a gate electrode formation process using a STAR(step gated asymmetric recess), by forming a STAR mask while a pad nitride layer is left under an isolation layer, by etching the pad nitride layer while using the STAR mask and by forming a protrusion in the center of a substrate while using the etched pad nitride layer as a hard mask. A pad oxide layer(111) is formed on a substrate(110) having a field region and an active region. A pad nitride layer(112) is formed on the pad oxide layer. The pad nitride layer and the substrate in the field region are etched to form a trench. An isolation layer(113) is formed to fill the trench. An etch mask is formed to expose a part of the pad nitride layer in the active region. An etch process using the etch mask is performed to etch the exposed pad nitride layer. After the etch mask is eliminated, an etch process using the etched pad nitride layer as a hard mask is performed to recess a predetermined depth of the exposed substrate. The pad nitride layer is removed by using H3PO4 to form a protrusion in the center of the substrate.