Pattern placement accuracy in block copolymer directed self-assembly based on chemical epitaxy.

Area of Science:

• Materials Science
• Nanotechnology
• Polymer Chemistry

Background:

• Block copolymer directed self-assembly (DSA) offers a route to dense circuit patterns.
• Precise registration of self-assembled features to guiding templates is crucial for viable circuit designs.
• Understanding DSA placement error is essential for advanced microelectronics fabrication.

Purpose of the Study:

• To quantitatively measure directed self-assembly (DSA) placement error.
• To investigate the relationship between DSA placement error and chemical prepattern characteristics.
• To establish a basis for optimizing prepattern designs for improved DSA registration.

Main Methods:

• Utilized an inorganic, domain-selective prepattern material for imaging after polymer removal.
• Employed a prepattern design with an in situ registration mark identifiable by pattern symmetry.
• Measured DSA placement error for lamellar block copolymer domains indexed to specific prepattern lines for spatial frequency tripling and quadrupling.

Main Results:

• DSA placement error was found to be correlated with the average prepattern line width.
• Prepattern pitch uniformity was also identified as a factor influencing DSA placement error.
• The study provides an estimation of DSA placement error for uniform, optimized prepatterns.

Conclusions:

• Accurate characterization of DSA placement error is achievable using advanced imaging and registration techniques.
• Prepattern design parameters, specifically line width and pitch uniformity, significantly impact DSA registration accuracy.
• These findings are critical for the successful implementation of DSA in high-resolution lithography for next-generation electronics.