METHOD OF MANUFACTURING SEMICONDUCTOR DEVICE HAVING MULTIPLE CHANNELS MOS TRANSISTOR

摘要

A method for fabricating a semiconductor device including a multiple channel MOS transistor is provided to simplify an ion implantation process of a source/drain layer by forming a planarized source/drain layer on the upper surface of a semiconductor device without a facet. A preliminary active pattern(40) is formed on a semiconductor substrate(10) wherein a plurality of gate formation layers and a plurality of single crystal silicon layers are repeatedly stacked in the preliminary active pattern. A hard mask is formed on the preliminary active pattern. By using the hard mask, the preliminary active pattern is etched to the surface of the substrate to form an active channel pattern. A source/drain layer having a flat upper surface is formed in a portion removed in forming the active channel pattern. The plurality of gate formation layers are selectively etched to form a plurality of tunnels. A gate(50) fills the plurality of tunnels, surrounding the active channel pattern and protruding to the upper portion of the active channel pattern. The gate formation layer can be made of germanium or silicon germanium having etch selectivity with respect to the single crystal silicon layer.