Self-aligned double patterning formation method

Abstract

Provided is a self-aligned double patterning formation method. The method comprises the following steps: a material layer to be etched is provided; a bottom part antireflective layer and a photo-resist layer which are soluble in a developing solvent are formed on the surface of the material layer to be etched; exposure and developing are synchronously performed on the bottom part antireflective layer and the photo-resist layer so that a patterned sacrificial bottom part antireflective layer and a sacrificial photo-resist layer are formed; first covering film material layers are formed on the surface of the material layer to be etched, the side wall surfaces of the sacrificial bottom part antireflective layer and the sacrificial photo-resist layer and the surface of the sacrificial photo-resist layer; the first covering film material layers are back-etched so that first covering film patterns are formed; and the sacrificial bottom part antireflective layer and the sacrificial photo-resist layer are removed. The bottom part antireflective layer and the photo-resist layer after exposure are synchronously soluble in the developing solvent so that the sacrificial photo-resist layer does not need to be utilized as a covering film to etch the bottom part antireflective layer, and one step in etching technology is saved. Besides, side wall appearance of a first covering film pattern is great so that the side wall appearance of the finally formed etching pattern is great.

Description

technical field [0001] The invention relates to semiconductor technology, in particular to a method for forming a self-aligned double pattern. Background technique [0002] In the field of semiconductor manufacturing, photoresist materials are used to transfer mask images to one or more material layers, for example, transfer mask images to metal layers, dielectric layers or semiconductor substrates. However, as the feature size of the semiconductor process continues to shrink, it becomes more and more difficult to form a mask pattern with a small feature size in the material layer by using a photolithography process. [0003] In order to improve the integration level of semiconductor devices, various double patterning processes have been proposed in the industry, among which the self-aligned double patterning (Self-Aligned Double Patterning, SADP) process is one of them. Figure 1 to Figure 6 A method for etching a semiconductor structure using a self-aligned double pattern ...

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Problems solved by technology

[0011] However, the inventors have found that the sidewall morphology of the etched pattern formed by etching the material layer to be etched using the above method is relatively poor, and the process is cumbersome.

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