Single photomask, multilevel kinoforms in quartz and photoresist: manufacture and evaluation

Abstract

Kinoforms manufactured in photoresist by photolithographic techniques using a single, ten-level, grey scale photomask, exposed in a specially designed laser exposure system, are described. Kinoforms designed for uniform as well as for partial Gaussian beam illumination are discussed. The highest measured diffraction efficiency was 55%. Photoresist kinoforms were transferred into quartz substrates by reactive ion etching. The highest measured diffraction efficiency for the resulting all-quartz kinoforms was 53%.

Nd:YAG laser machining with multilevel resist kinoforms

“…Hence, in these laboratory experiments the laser beam power was used inefficiently. In a practical laser machining situation the kinoform should be made larger than the laser beam, and thus designed for partial illumination [6].…”

Specifying and Testing Digital Optics

“…Digital optics are not ICs, and therefore there are different criteria to be taken into consideration during fabrication [20,21]. One of these is the etch depth, and the other is the surface roughness.…”

“…When a field is misaligned to a previously transferred field on the wafer, high-frequency artifacts appear on the structures [20][21][22]. These artifacts can be much smaller than the resolution of the lithographic tool.…”

<title>Photolithography for the static compensation of human eye aberrations</title>

“…Although initially developed to satisfy the needs of the microelectronics industry (and thus having a highly nonlinear ___________________________________ response, well-suited to obtain sharp relief transitions) they can be exposed silve-halide gray-tone masks [24][25][26]. This procedure has also been applied to the fabrication of medium-sized refractive elements [23] compensating preparing the photoresist layer (cleaning substrates, spin-coating photoresist, soft baking for hardening); (v) exposing the photoresist layer to UV radiation through the gray-tone mask (either by contact or projection); (vi) developing photoresist and (vii) checking the optical quality of the elements thus fabricated (phase transmittance function and surface roughness) by interferometry (or wavefront sensing) and profilometry (or alternative surface inspection techniques).…”