Method for manufacturing semiconductor device

Abstract

A method for manufacturing a semiconductor device includes the steps of preparing a semiconductor substrate provided with a cell area and a peripheral area, forming gate structures, forming a first side wall spacer on a side of each gate structure, growing up a single crystal silicon layer formed on an exposed portion of the semiconductor substrate by using a selective epitaxial growth method, forming a second and a third patterned insulating layers in the cell area and forming a second and a third side wall spacers in the peripheral area, carrying out an ion implantation to semiconductor substrate in the peripheral area, removing the third patterned insulating layer and the third side wall spacer, forming an interlayer insulating layer on the semiconductor substrate and the gate structures, patterning the interlayer insulating layer into a second predetermined configuration, whereby the interlayer insulating layer does not remain in the cell area and the second patterned insulating layer is patterned into a side wall pattern, forming a conductive layer on the cell area and the peripheral area, and planarizing a surface of the conductive layer, thereby obtaining a contact plug in the cell area.