Semiconductor structure and forming method thereof

Abstract

The invention discloses a semiconductor structure and a forming method thereof. The forming method comprises the steps of providing a substrate, a gate structure, a side wall located on the side wall of the gate structure, a source-drain doped region, a bottom dielectric layer and a source-drain contact layer; removing the side wall to form a gap; forming a protective layer covering the bottom and the side wall of the gap in a shape-preserving manner; and forming a top dielectric layer on the bottom dielectric layer, wherein the top dielectric layer seals the gap to form an air gap. According to the embodiment of the invention, after the substrate is provided, the side walls are removed to form the gap, the bottom and the side walls of the gap are covered with the protective layer in a shape-preserving manner, and then the top dielectric layer for sealing the gap is formed, so that the air gap and the protective layer are correspondingly of an integrated structure, and the protection effect of the protective layer on the bottom and the side walls of the gap is improved; the damage probability of the film layer structures (such as the gate structure and the substrate) at the bottom and the side wall of the gap is reduced, the integrity of the film layer structures at the bottom and the side wall of the gap is correspondingly improved, and then the reliability and the production yield of the semiconductor structure are improved.

Description

technical field [0001] Embodiments of the present invention relate to the field of semiconductor manufacturing, and in particular, to a semiconductor structure and a method for forming the same. Background technique [0002] With the continuous development of integrated circuit manufacturing technology, people's requirements for the integration and performance of integrated circuits are becoming higher and higher. In order to improve the integration level and reduce the cost, the critical dimensions of the components are becoming smaller, and the circuit density inside the integrated circuit is increasing. This development makes the wafer surface unable to provide enough area to make the required interconnection lines. [0003] In order to meet the requirements of interconnect lines after the critical dimension has been shrunk, the current conduction between different metal layers or the metal layers and the substrate is achieved through an interconnect structure. The inter...

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Problems solved by technology

[0005] However, the performance of current semiconductor structures still needs to be improved

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