Fabrication issues in micromachined tunable optical filters

Prototypes of micromachined tunable infrared optical filters are being produced. Micromachining silicon for use in these filters requires the integration of multilayer dielectric optical coatings such as ZnSe/ThF4. These coatings are novel materials for integration with microlithographic processing. Devices were engineered and a process flow was developed to avoid contaminating processing tools with the coating. A method for patterning the coating was developed. Low-temperature bonding techniques have been explored and tested. Fabrication issues for these micromachined devices are discussed.