A Water-repellent Silanization Coating Technique for MEMS

Abstract

A gas-phase water-repellent silanization coating technique, which prevents the microscopic structures used for micro-sensors and micro-electro-mechanical systems (MEMS) from sticking to the silicon substrates and other microscopic structures during operation, have been developed. Use of a water-repellent coating is one method that prevents sticking by reducing the surface energy of the structure. The water-repellency characteristics of three types of organosilicon compounds were evaluated. It was found that a water-repellent silanization coating layer using (tridecafluoro - 1, 1, 2, 2 -tetrahydrooctyl) trichlorosilane (C₈H₄Cl₃F₁₃Si) had most excellent durability. It was confirmed that the water contact angle of C₈H₄Cl₃F₁₃Si coating layer is exceeding 90 degrees at surface of standard semiconductor materials except nickel. In addition, the C₈H₄Cl₃F₁₃Si coating layer can be patterned by ultraviolet irradiation.