A review of laser–microchemical processing

Microfabrication processes based on focused laser-beam activation of surface chemistry are reviewed with an emphasis on the classification of the diverse chemical processes used. Surface reactions are divided according to their method of activation and the material phase most important in the chemical kinetics. Examples of reaction mechanisms and means of confining reaction dimensions are given. New results demonstrating that linewidths for deposition and etching of Si can be <0.4 μm are described. The ultimate limits to spatial resolution are explored in terms of an effective contrast (γ*) for laser–microchemical processes. Enhanced diffusive transport, characteristic of laser microreactions, and its effect on ultimate reaction rates are also analyzed.