1. Photo lithography

2. Why? Add a photo sensitive layer ontop of a material. After treating with UV light, remove the affected areas. After processing (e.g. etching) remove remaining layer. Transfer a pattern onto a material How

3. Pattern transfer in four steps 1.Exposure 2.Development 3.Processing; e.g. etching 4.Stripping

4. 1 Exposure Material to be patterned Fotomask Fotoresist Light source

5. Material to be patterned Fotoresist 2 Developement Developer (solution)

6. Compare photo mask and resulting resist Fotomask Patterned photoresist Material Resulting structure

7. Etchant solution Patterned photoresist Material 3 Processing, e.g etching

8. Patterned photoresist Patterned Material Resulting structure

9. 4 Stripping Stripping solution Patterned photoresist Patterned Material

10. Resulting structure Patterned Material Compare photo mask and resulting resist Fotomask

11. Reflections Why/when is fotolithography needed? How is a mask created? Why do mask and resulting structure differ? Which parameters influence the result?