Figure 40.2: Schematic drawing of a photolithographic process sequences.

2. Lithography techniques:

• Lithography:

Lithography is the process of transferring a pattern into a reactive polymer film, termed as resist, which will be subsequently used to replicate that pattern into an underlying thin film or substrate [6,7]. Many techniques of lithography have been developed in the last half a century with various lens systems and exposure radiation sources including photons, X-rays, electrons, ions and neutral atoms. In spite of different exposure radiation sources used in various lithographic methods and instrumental details, they all share the same general technical approaches and are based on similar fundamentals. Here, we shall cover photolithography, electronbeam lithography, focused ion-beam lithography and X-ray lithography techniques.