Functional integrated optical elements for beam shaping with coherence scrambling property, realized by interference lithography

Abstract

Many applications, such as semiconductor lithography and material processing, require the shaping of laser beams to provide a homogenous field illumination. We present the conception, implementation, and experimental verification of a combined single-element homogenizer. Additionally, for excimer laser applications, the concept is associated with a coherence scrambling capability. We used the technique of holographic interference lithography to integrate the multifunctional properties in a diffractive optical element. The wavelength difference between the recording process (457.9 nm) and the application (193 nm) results in a change of the imaging properties and requires a geometrical adaptation of the optical setup. The coherence scrambling effect of the setup is based on an off-axis design, including the beam shaping diffractive structure.