Method for forming self-aligned triple pattern

Abstract

Provided is a method for forming a self-aligned triple pattern. The method comprises: providing a layer to be etched, wherein the surface of the layer to be etched is equipped with a discrete first sacrificial layer; forming a second sacrificial film on the surface of the layer to be etched and the sidewall and the top of the first sacrificial layer and forming a first sidewall layer on the surface of the second sacrificial film; planarizing the second sacrificial film and the first sidewall layer until the top surface of the first sacrificial layer is exposed, the first sidewall layer forms a first sidewall, the second sacrificial film forms a second sacrificial layer, and the tops surfaces of the second sacrificial layer and the first sidewall are aligned to the top surface of the first sacrificial layer; removing the first sacrificial layer after a planarization process is executed; forming a second sidewall on the surface of the layer to be etched on the two sides of the second sacrificial layer and the first sidewall; dry etching the second sacrificial layer by using the first sidewall and the second sidewall as a mask until the surface of the layer to be etched is exposed. A formed self-aligned triple pattern has a small size and a simple forming process.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to a method for forming a self-aligned triple pattern. Background technique [0002] With the continuous progress of semiconductor technology, the process nodes of semiconductor devices are continuously reduced. However, due to the limitation of the precision of the existing photolithography process, the mask pattern formed by the existing photolithography process is difficult to meet the demand for continuous reduction of the feature size of semiconductor devices, which hinders the development of semiconductor technology. [0003] In order to further reduce the size of the semiconductor device on the basis of the existing photolithography process, a double patterning process is proposed in the prior art. Among them, the self-aligned double patterning (Self-Aligned Double Patterning, SADP) process is widely used because of its simplicity. [0004] Figure 1 to ...

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Problems solved by technology

[0009] However, the size of the mask formed by the self-aligned double patterning process of the prior art is still limited and cannot be further reduced

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