Fabrication techniques for surface-acoustic-wave and thin-film optical devices

A review of two-dimensional, or planar, fabrication techniques is presented. The basic principles of the planar fabrication technique include the coating of a substrate surface with a radiation-sensitive polymer film and the exposure of this film to radiation in some desired pattern. A removal of either the exposed or unexposed polymer leaves the pattern in relief on the substrate surface. The substrate itself can then be patterned by etching, doping, or the deposition of another material. Aspects of photolithography are examined, giving attention to projection printing, shadow printing, and holographic recording. Questions of electron lithography are also considered, taking into account the historical background of this field and details of scanning-electron-beam lithography. X-ray lithography is a shadow printing technique, similar in principle to photolithographic shadow printing. Developments in ion-bombardment etching are also explored.