Semiconductor structure and formation method thereof

Abstract

The invention relates to a semiconductor structure and a formation method thereof. The formation method comprises the steps of providing a material layer to be etched; forming patterned core layers onthe material layer to be etched; forming a side wall film on the top and side walls of the core layers and on the material layer to be etched; performing at least one time of top treatment on the side wall film to remove the side wall film higher than the top of the core layers, reserving the side wall film on the side walls of the core layers to serve as a first portion of a side wall layer, reserving the side wall film on the material layer to be etched to serve as a second portion of the side wall layer, wherein the top treatment comprises the steps of forming a sacrificial layer coveringthe surface of the side wall film on the side walls and the top of the core layers on the side wall film, removing the sacrificial layer higher than the top of the core layers and part or all thickness of the side wall film and removing the remaining sacrificial layer; removing the core layers; and removing the second portion of the side wall layer after the core layers are removed. The first portion of the side wall layer is symmetrical in shape, and a target pattern with the shape being good can be obtained by etching the material layer to be etched by taking the first portion of the side wall layer as a mask.

Description

technical field

[0001] The present invention relates to the field of semiconductors, and in particular, to a semiconductor structure and a method for forming the same. Background technique

[0002] Semiconductor technology continues to move toward smaller process nodes, driven by Moore's Law. With the continuous advancement of semiconductor technology, the functions of devices are constantly becoming stronger, but the difficulty of semiconductor manufacturing is also increasing day by day. Lithography is the most critical production technology in the semiconductor manufacturing process. With the continuous reduction of semiconductor process nodes, the existing light source lithography technology has been unable to meet the needs of semiconductor manufacturing. Extreme ultraviolet lithography technology (EUV), many Beamless mask technology and nanoimprint technology have become research hotspots for next-generation lithography candidates. However, the above-mentioned next-g...

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