Defect analysis and alignment quantification of line arrays prepared by directed self-assembly of a block copolymer

Abstract

Different linear patterns obtained from the directed self-assembly of the block copolymer (BCP) polystyrene-b-polyethylene oxide (PS-b-PEO) were analysed and compared. The hexagonal phase PS-b-PEO in a thin film exhibits linear pattern morphology, by conventional solvent annealing in an atmosphere saturated in chloroform. The surface energy of the silicon substrates was varied using surface functionalization of a self-assembly monolayer (SAM) and a polymer brush, chosen to investigate the influence of the surface energy on the self-assembly of the BCP. The linear patterns formed were analyzed with innovative image analysis software specifically developed in our laboratory to identify elements and defects of line arrays from block copolymer self-assembly. The technique starts by performing dimensional metrology to calculate the pitch size and estimate the linewidth of the lines. Secondly, the methodology allows identification and quantification of typical defects observable in BCP systems, such as turning points, disclination or branching points, break or lone points and end points. The defect density and the quantification of the alignment were estimated using our technique. The methodology presented here represents a step forward in dimensional metrology and defect analysis of BCP DSA systems and can be readily used to analyze other lithographic or non-lithographic patterns.

Study of the Kinetics and Mechanism of Rapid Self-Assembly in Block Copolymer Thin Films during Solvo-Microwave Annealing

“…The defect analysis obtained from the method described earlier enabled us to estimate the defect density, making it possible to statistically quantify the order of the line patterns within the experimental error on the basis of the density of turn points in the line array. Figure summarizes the statistics for the samples studied here.…”

“…To estimate the defect density in the images, we have used our recently developed defect analysis software . The code has been developed to identify lines and defects specifically from block copolymer self-assembly.…”

“…The defect density is then estimated as follows: The collected statistics concerning the identification and quantification of the defects is summarized in Figure . More details about the software and defect types can be found in ref .…”

“…We have modified the system to carefully monitor temperature and extended the substrate range to amplify our model, and this is reported here. Our results are quantified through defect analysis software that we have developed for BCP thin film metrology …”

Nanoscale silicon substrate patterns from self-assembly of cylinder forming poly(styrene)-block-poly(dimethylsiloxane) block copolymer on silane functionalized surfaces

“…In "top-down" methodologies for example, further progress is critically related to several issues including source design, material interactions and thermal management [9], [10]. On the other hand, it is highly challenging to achieve long-range translational order and robustness of systems fabricated with "bottom-up" approaches [11], [12], [13], [14].…”