Airgap structure and method of manufacturing thereof

摘要

A process for fabricating a gate structure, the gate structure having a plurality of gates defined by a network of spaces. The word line (WL) spaces within a dense WL region having airgaps and those spaces outside of the dense WL being substantially free of airgaps. A gate structure having a silicide layer dispose across the plurality of gates is also provided.

主权项

1. A method of fabricating a gate structure comprising:
providing a gate structure assembly having a plurality of gates disposed across a substrate defined by a network of spaces, the gate structure assembly defined by a dense word line (WL) region; applying a deposition layer to form void spaces in any space of the dense WL region; forming a first interlayer dielectric across the gate structure; removing a cap layer disposed on the gate structure to form openings in the void spaces; constructing a silicide layer on the plurality of gates; and forming a second interlayer dielectric across the plurality of gates, wherein the second interlayer dielectric comprises a buffer oxide layer, silicon nitride film, and at least one of a silicon oxide layer and an undoped silicon glass layer.