Image transfer process employing a hard mask layer

Abstract

At least one mask layer formed over a substrate includes at least one of a dielectric material and a metallic material. By forming a first pattern in one of the at least one mask layer, a patterned mask layer including said first pattern is formed. An overlying structure including a second pattern that includes at least one blocking area is formed over said patterned mask layer. Portions of said patterned mask layer that do not underlie said blocking area are removed. The remaining portions of the patterned mask layer include a composite pattern that is an intersection of the first pattern and the second pattern. The patterned mask layer includes a dielectric material or a metallic material, and thus, enables high fidelity pattern transfer into an underlying material layer.

Description

BACKGROUND[0001]The present disclosure generally relates to a process for manufacturing semiconductor structures, and particularly to an image transfer process employing a hard mask layer to memorize a composite pattern, and structures for effecting the same.[0002]A trilayer lithography process as known in the art employs an organic material layer such as an amorphous carbon layer in order to transfer a composite image of two independent images. The sidewalls of the organic material layer are formed with a significant level of line edge roughness and line width roughness during a pattern transfer etch that forms a pattern in the organic material layer employing an overlying layer as a patterned mask because the organic material layer is prone to lateral etching. The line edge roughness and the line width roughness of the organic material layer are further increased during a subsequent pattern transfer etch that transfers the pattern in the organic material layer into an underlying l...

AI Technical Summary

Benefits of technology

The patent describes a method for creating a highly precise pattern in a material layer. A mask layer is formed over a substrate, which can be made of either a dielectric material or metal. The mask layer is then patterned using a first pattern, which forms a patterned mask layer. An overlying structure made of a second pattern is then formed over the patterned mask layer. Only the portions of the mask layer that don't fall within the borders of the second pattern are removed, leaving behind a composite pattern that is a combination of the first and second patterns. This patterned mask layer can serve as a high-fidelity pattern transfer tool for creating precise patterns in an underlying material layer.

Problems solved by technology

Thus, the fidelity of pattern transfer is degraded due to the lateral etching of the organic material layer in the material stack employed for the trilayer lithography process.

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