Method for forming mandrel pattern

Abstract

The invention provides a mandrel pattern forming method, and the methodcomprises the following steps: providing a substrate, and sequentially forming a mandrel pattern layer, a transition layer and apatterned spin-coating dielectric layer above the substrate, wherein the hardness of the transition layer is greater than that of the spin-coating dielectric layer; etching the transition layer by taking the graphical spin-coating dielectric layer as a mask to form a graphical transition layer; removing the patterned spin-coating dielectric layer, and etching the mandrel pattern layer by taking the patterned transition layer as a mask to form a mandrel pattern. By adding the transition layer between the mandrel pattern layer and the patterned spin-coating dielectric layer, the film layer structure in the mandrel pattern etching process is changed, the thickness of an organic dielectric layer in the patterned spin-coating dielectric layer can be reduced, and meanwhile, the problem that thethickness of a mask layer is insufficient in the etching process of the mandrel pattern layer is solved.

Description

technical field [0001] The invention relates to the field of semiconductors, in particular to a method for forming mandrel patterns. Background technique [0002] As device dimensions decrease, critical dimensions in semiconductor manufacturing continue to decrease, even beyond the limits of lithography processes. Under such conditions, in order to obtain a structure that can meet the requirements of critical dimensions, it is necessary to use self-aligned double patterning (Self-aligned Double Patterning, SADP). This process first forms a core (Core) figure, by forming side walls on both sides of the core figure, and then defining the size of subsequent figures through the size of the side walls. [0003] In the mandrel pattern etching process, a spin-on dielectric layer is widely used, and the spin-on dielectric layer includes an organic dielectric layer (ODL) and a silicon-containing anti-reflection layer (Si-ARC). However, since the material of the organic dielectric l...

AI Technical Summary

Problems solved by technology

However, this solution will reduce the process window and cause the problem that the organic dielectric layer does not protect the lower film layer enough.

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