Common gate and salicide word line process for low cost embedded dram devices

Abstract

A process for forming logic devices with salicide shapes on gate structures, as well as on heavily doped source/drain regions, while simultaneously forming embedded DRAM devices with salicide shapes only on gate structures, has been developed. The process features silicon oxide blocking shapes, formed in the spaces between gate structures, in the embedded DRAM device region. The silicon oxide blocking shapes are formed using a high density plasma deposition procedure which deposits a thick silicon oxide layer in the narrow spaces between gate structures in the embedded DRAM device region, and a thin silicon oxide layer in the wider spaces between gate structures in the logic device region, and on the top surface of all gate structures. A blanket, dry etch procedure is then employed to remove the thin silicon oxide layers from the top surface of all gate structures, as well as from the spaces between gate structures in the logic device region, while forming the desired silicon oxide blocking shapes between gate structures in the embedded DRAM device region, therefore allowing subsequent salicide shapes to be formed only on the top surface of gate structures, and on heavily doped source/drain regions in the logic device region.