Effects of segregation strength and an external field on the thermal line edge and line width roughness spectra of a diblock copolymer resist

Abstract

The author uses computer simulations to measure the spectra of thermal line edge roughness (LER) and line width roughness (LWR) in a two-dimensional, symmetric, lamellar diblock copolymer melt over a range of segregation strengths. These measurements demonstrate that increased segregation strength results in a significant suppression of periodic LER and LWR with a wavelength of order of the pattern pitch. The author also examines the effects of a chemically selective external field on the LER and LWR spectra and finds that not only does the external field suppress long-wavelength and periodic LER and LWR but also it acts to decouple interface-interface fluctuations, as measured by the interface-interface covariance. These results will prove useful for block copolymer (BCP) resist design as they highlight the ability to tune the LER and LWR spectra via manipulating BCP segregation strength and the properties of a chemically selective external field. Furthermore, these simulations will function as an important baseline model for planned diffraction experiments aimed at measuring the BCP thermal LER and LWR spectra.