Integration of Benzocyclobutene Poymers and Silicon Micromachned Structures Fabricated with Anisotropic Wet Etching

Title of thesis: INTEGRATION OF BENZOCYCLOBUTENE POYMERS AND SILICON MICROMACHNED STRUCTURES FABRICATED WITH ANISOTROPIC WET ETCHING Nima Ghalichechian, Master of Science, 2005 Thesis directed by: Professor Reza Ghodssi Department of Electrical and Computer Engineering Integration of low dielectric constant Benzocyclobutene (BCB) film with deep etched structures in silicon allows the fabrication of MEMS devices with low parasitic loss. A fabrication process is developed for integration of thin BCB film and deep anisotropically-etched grooves in silicon using potassium hydroxide (KOH). Gold (Au) is used as an etch mask to protect the low-k film during the highlycorrosive, long, and high-temperature KOH etching process. Metal/BCB adhesion is a key parameter in this masking design. Adhesion of the BCB and metal mask was improved by cure management of the BCB before and after metallization, surface treatment of the BCB before metallization, and high-temperature metallization. Test structures were fabricated to demonstrate the feasibility of this fabrication process. Adhesion improvement was successfully verified by studying BCB/metal interface using time-of-flight secondary ion mass spectroscopy and Auger electron spectroscopy. This study enables the development of the next generation micromotors/microgenerators.