Overcoming challenges in fabrication of beam shaping meta-optics using sensitive mr-EBL resist

Abstract

Shaping light to meet the needs of diverse optical applications is of utmost importance. Beam shaping allows one to alter the properties of light, enabling more complex behavior not possible with standard beams, such as Gaussian beams. Such beams have been generated using diffractive optics and more recently, metaoptics. For the latter, standard fabrication processes using electron beam lithography with the popular polymethyl methacrylate resist exist. However, there are several challenges due to the sub-wavelength features. We propose an alternate fabrication approach using a highly sensitive resist called mr-EBL resist. We show how the use of this resist reduces the patterning time, as well as the number of process steps. The process is explained with a case study on the fabrication of a meta-optical element that generates a modified Bessel beam with special properties.