Method of manufacturing a semiconductor device

Abstract

A method may include forming a first gate structure on a first region of a substrate, forming a bit line structure on the first gate structure, forming a preliminary contact plug layer including amorphous silicon on the substrate, forming a reflective layer structure on the preliminary contact plug layer, forming a contact plug layer from the preliminary contact plug layer, and forming a capacitor on the contact plug layer. The reflective layer structure may include first and second reflective layers. A refractive index of the second reflective layer may be being greater than that of the first reflective layer. Portions of the second reflective layer may have different thicknesses on first and second regions of the substrate. The forming the contact plug layer may include performing a melting laser annealing (MLA) process on the reflective layer structure to convert the amorphous silicon of the preliminary contact plug layer into polysilicon.