Self-aligned silicide process for forming silicide layer over word lines in dram and transistors in logic circuit region

Abstract

A self-aligned process for forming a silicide layer over word lines in DRAM and a silicide layer over transistors in a logic device region. A substrate that includes a memory cell region and a logic circuit region is provided. A first transistor and a second transistor are formed over the substrate. The first transistor is formed in the logic circuit region and includes a first gate conductive layer and a first source/drain region. The second transistor is formed in the memory cell region and includes a second gate conductive layer and a second source/drain region. A blocking layer is formed over both the first transistor and the second transistor. A portion of the blocking layer is removed to expose the first gate conductive layer, the first source/drain region and the second gate conductive layer. The remaining blocking layer still covers the second source/drain region. A metal silicide layer is formed over the first gate conductive layer, the first source/drain region and the second gate conductive layer.