GAP FILL FOR UNDERLAPPED DUAL STRESS LINERS

摘要

A gap fill nitride is formed in an underlapping region between a first semiconductor area with a first stress liner and a second semiconductor area with a second stress liner without plugging other tightly spaced structures. This is achieved by filling the tightly spaced structures with middle-of-line dielectric material such as silicon oxide in both the first and the second semiconductor areas prior to the formation of the gap fill nitride. The combination of the first and second stress liners and the gap fill nitride provides a continuous mobile ion diffusion barrier across the entire surface of a CMOS semiconductor structure.