Etch process for reducing directed self assembly pattern defectivity

摘要

Provided is a method for preparing a patterned directed self-assembly layer, comprising: providing a substrate having a block copolymer layer comprising a first phase-separated polymer defining a first pattern in the block copolymer layer and a second phase-separated polymer defining a second pattern in the block copolymer layer; and performing an etching process to selectively remove the second phase-separated polymer while leaving behind the first pattern of the first phase-separated polymer on the surface of the substrate, the etching process being performed at a substrate temperature less than or equal to about 20 degrees C. The method further comprises providing a substrate holder for supporting the substrate, the substrate holder having a first temperature control element for controlling a first temperature at a central region and second temperature control element at an edge region of the substrate and setting a target value for the first and the second temperature.

主权项

1. A method for preparing a patterned directed self-assembly (DSA) layer, comprising:
providing a substrate having a block copolymer layer on a surface thereof, said block copolymer layer comprising a first phase-separated polymer defining a first pattern in said block copolymer layer and a second phase-separated polymer defining a second pattern in said block copolymer layer; selecting defined values of pattern defectivity for preventing pattern collapse for a set of pattern roughness metrics, wherein said set of pattern roughness metrics of said first pattern include a mean value of line width roughness, a line edge roughness for a first edge, and a line edge roughness for a second edge; performing an etching process to selectively remove said second phase-separated polymer while leaving behind said first pattern of said first phase-separated polymer on said surface of said substrate, said etching process being performed at a substrate temperature less than or equal to about 20 degrees C.; and during said performing said etching process, monitoring said set of pattern roughness metrics of said first pattern using metrology measurements, and controlling said substrate temperature to maintain said set of pattern roughness metrics below defined values of pattern defectivity for preventing pattern collapse.