Maskless microetching of transparent conductive oxides (ITO and ZnO) and semiconductors (GaAs) based on reaction-diffusion

A maskless-but-parallel method of etching micropatterns in transport conducting oxides (ITO and ZnO) and semiconductors(GaAs) based on reaction-diffusion was analyzed. Both types of materials are of great importance in modern technology and are used in optoelectronic devices (ITO electrodes), sensors and prototype on chip UV lasers, integrated circuits, high-efficiency solar cells and optical switches. Serial methods based on laser scanning or focused ion beam (FIB) techniques offer direct maskless and resistless patterning, but require expansive equipment and are relatively slow, especially at high resolutions. A combination of reaction and diffusion initiating from hydrogel stamps can circumvent these limitations and allow for direct imprinting of microscopic reliefs into ITO, ZnO and GaAs films. Results show that the easy-to-make hydrogel sponges can personalize microstructuring of solid materials much in the same way that microcontact printing personalized surface patterning.