Self-aligned double patterning formation method

Abstract

A self-aligned double patterning formation method comprises the steps of providing a material layer to be etched, forming a sacrificial photoresist layer on the material layer to be etched, forming a polymer layer on the surfaces of the top and the side walls of the sacrificial photoresist layer, forming a first mask material layer on the surface of the polymer layer, and back-etching the first mask material layer to enable the first mask material layer on the two sides of the sacrificial photoresist layer to form a first mask pattern. As the polymer layer is formed on the surfaces of the top and the side walls of the sacrificial photoresist layer, and the hardness of the polymer layer is far higher than that of the sacrificial photoresist layer, the shape of the sacrificial photoresist layer does not deform due to stress generated by the first mask material layer. Moreover, the rotation angle of the polymer layer formed by the use of a deposition process and an etching process is a right angle, which enables the sidewall morphology of the final etched pattern to be good.

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 ...

AI Technical Summary

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.

Images