All track directed self-assembly of block copolymers: process flow and origin of defects

Abstract

Directed Self-Assembly (DSA) of block copolymers is considered to be a potential lithographic solution to achieve higher feature densities than can be obtained by current lithographic techniques. However, it is still not well-established how amenable DSA of block copolymers is to an industrial fabrication environment in terms of defectivity and processing conditions. Beyond production-related challenges, precise manipulation of the geometrical and chemical properties over the substrate is essential to achieve high pattern fidelity upon the self-assembly process. Using our chemo-epitaxy DSA approach offers control over the surface properties of the slightly preferential brush material as well as those of the guiding structures. This allows for a detailed assessment of the critical material parameters for defect reduction. The precise control of environment afforded by industrial equipment allows for the selective analysis of material and process related boundary conditions and assessment of their effect on defect generation.In this study, the previously reported implementation of our feature multiplication process was used to investigate the origin of defects in terms of the geometry of the initial pre-patterns. Additionally, programmed defects were used to investigate the ability of the BCP to heal defects in the resist patterns and will aid to assess the capture capability of the inspection tool. Finally, the set-up of the infrastructure that will allow the study the generation of defects due to the interaction of the BCP with the boundary conditions has been accomplished at imec.

Photochemical Reactions for Replicating and Aligning Block Copolymer Thin Film Patterns

“…[8,9] They possess 3X density multiplication for 14 nm halfpitch PS-PMMA, meaning the feature density of the PS-PMMA pattern is triple that of the chemical guiding pattern. [10] Lamella-forming PS-PMMA with a microdomain periodicity (i.e.…”

Readying Directed Self-Assembly for Patterning in Semi-Conductor Manufacturing

“…At first, it is determined how process variables impact defect formation in DSA processing. The control that the LiNe flow offers over the geometry as well as the surface properties of the chemical pre-patterns is crucial in this respect [23][24][25][26]. Secondly, we intend to demonstrate that DSA can approach defect densities that are sufficiently low for the purpose of semi-conductor manufacturing.…”

Scale-up of a Chemo-Epitaxy Flow for Feature Multiplication Using Directed Self- Assembly of Block-Copolymers

“…Most of these defects were healed after BCP assembly, as they are capable to correct minor patterning defects by reaching thermodynamic equilibrium states during thermal annealing. [20] The second source of defects was related to particles in the brush material. Finally, SEM inspections of the new locations where a defect could exist after PMMA removal (509/cm 2 ) showed that particles in the BCP material account for about 60% of the adder defects, some dislocations and clusters were related to processing non-uniformities, and at about 30% of the locations, no defects could be found.…”