One-step lithography for mass production of multilevel diffractive optical elements using high-energy beam sensitive (HEBS) gray-level mask

Micro-optics such as diffractive optics and computer generated holograms are essential components for modern optical design. To reduce their unit fabrication cost we describe a method of reproducing micro-optics in quantities. A true gray-level mask was fabricated in High Energy Beam Sensitive (HEBS)-Glass by means of a single e-beam direct write step. This gray-level mask was used in a optical contact aligner to print a multilevel Diffractive Optical Element (DOE) in a single optical exposure. A chemically assisted ion beam etching process has been used to transfer the DOE structure from the resist into the substrate.