An Iterative Algorithm for Lithography on Three-Dimensional Surfaces

Abstract

Photolithography is an optical and chemical process for the patterning of commonly at substrates with shapes which are useful for electronics and a number of other applications. Holography, in its most general sense, is the manipulation of the coherent properties of an optical wave-front to produce two or three dimensional light patterns. A combination of holography and photolithography therefore allows for the patterning of three dimensional substrates by exploiting the coherence of an optical source. The work in this thesis approaches an optical optimisation methodology centered around the iterative algorithms derived from the Gerchberg-Saxton algorithm. This allows the design of holograms which, in turn, allows the patterning of three dimensional surfaces. The system parameters for the design of two and three dimensional light patterns in this methodology are examined. Simulations and practical optical examples are provided throughout with some application-focused demonstrations. The result is an understanding of an iterative optimisation approach within the context of lithography, and an implementation and methodology for achieving three dimensional patterns.