Method for forming self-alignment duplex pattern

Abstract

The invention provides a method for forming self-alignment duplex pattern. The method comprises the following steps: providing a material layer to be etched, forming a sacrificial photoresist layer on the material layer to be etched, curing the sacrificial photoresist layer, forming a first mask pattern on the side wall surface of the sacrificial photoresist layer, and removing the sacrificial photoresist layer. As the sacrificial photoresist layer is cured, the hardness of the sacrificial photoresist layer is increased, and during the process of forming the first mask pattern, the sacrificial photoresist layer does not deform under the stress generated by the first mask material layer, so that the side wall of the sacrificial photoresist layer is still perpendicular to the surface of the material layer to be etched, and finally, the side wall of the etched pattern which is formed by etching the material layer to be etched has a better profile.

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.

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