Pattern forming method of a semiconductor structure

Abstract

The invention provides a method for forming a pattern of a semiconductor structure which includes providing a substrate, a target material layer, a first antireflective material layer, a second antireflective material layer and a photoresist layer, all of which are orderly formed. The photoresist layer is patterned to form a preset pattern. A photoresist layer having a preset pattern is taken as amask. A second antireflective material layer is etched by using a first etching gas. A first etch gas includes a photoresist etch mitigation gas, so that the etching selection ratio of the second antireflective material layer to the photoresist layer is greater than 3: 1. The first antireflective material layer is etched by using the second etching gas with the second antireflective layer as a mask, and the target material layer is etched by using the first antireflective layer as a mask to form the target layer with a preset pattern. By adopting the scheme, the semiconductor structure forming method of the invention can reduce the aspect ratio of the photoresist layer, effectively reduces the divergence degree, increases the exposure accuracy, and prevents the pattern damage phenomenon caused by the photoresist residue.

Description

technical field [0001] The invention belongs to the technical field of semiconductor manufacturing, in particular to a pattern forming method of a semiconductor structure. Background technique [0002] In the semiconductor manufacturing process, a photoresist layer (PR) and a middle mask layer are often used to copy the required pattern into the device to form the actual required semiconductor structure. In practice, in order to increase the effectiveness of photolithography, various antireflective coatings are usually coated under the photoresist layer, such as bottom antireflective coating (BARC), and the BARC layer under the photoresist layer (photoresist layer) can be Reduce the reflection of light on the lower surface of the photoresist during the exposure process, so that most of the energy of the exposure is absorbed by the photoresist. For uniform exposure of the photoresist, the more preferred material is an anti-reflection layer based on Si. Or Si-ARC. [0003] A...

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Problems solved by technology

[0005] In view of the above-mentioned shortcomings of the prior art, the object of the present invention is to provide a method for forming a pattern of a semiconductor structure, which is used to solve the photoresist collapse caused by too thick photoresist layer and the accuracy of CD in the prior art. And other issues

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