On the improvement of heterodyne displacement interferometry: Enhancing measurement linearity and system modularity

Lithographic exposure equipment for integrated circuit manufacturing requires ever more accurate position measurement systems, which is currently led by the advent of Extreme UltraViolet (EUV)-lithography machines. This PhD-research describes an interferometric displacement measurement system that possess the potential to foresee in the need for...

UV and electron-assisted oxidation of Al and Ru

To ensure a continuing miniaturization in the semiconductor industry, new technologies need to be developed to define ever smaller patterns on the silicon substrates. One of these emerging technologies is extreme ultraviolet (EUV) lithography. Unfortunately, EUV light causes oxidation of the optical components inside the lithography machine that...

The network structure of the merit function space of EUV mirror systems

The merit function space of mirror systems for EUV lithography is studied. Local minima situated in a multidimensional merit function space are connected via links that contain saddle points and form a network. In this work we present the first networks for EUV lithographic objectives and discuss how these networks change when control parameters...

CMOS integrator based lock-in pixel for heterodyne interferometry

This article presents a prototype of a CMOS phase sensor for high accuracy (1 Angstrom) heterodyne interferometry. Switched integrators realization of a lock-in pixel for 4-bucket phase detection algorithm is described and illustrated by experimental results. Factors that limit the accuracy of this implementation and possible ways for its...

Avoiding unstable regions in the design space of EUV mirror systems comprising high-order aspheric surfaces

When Extreme Ultraviolet mirror systems having several high-order aspheric surfaces are optimized, the configurations often enter into highly unstable regions of the parameter space. Small changes of system parameters lead then to large changes in ray paths, and therefore optimization algorithms crash because certain sssumptions upon which they...