METHOD FOR FABRICATING SURFACE ACOUSTIC WAVE FILTER USING DIAMOND THIN FILM

摘要

PURPOSE: A method for fabricating a SAW(Surface Acoustic Wave) filter using a diamond thin film is provided, which can obtain a considerable surface roughness without performing a polishing process directly on the diamond thin film. CONSTITUTION: A trench is formed on a unit element region on a substrate(10). And a diamond thin film(30) is formed only in the above trench. The first and the second metallic thin film pattern of an IDT(Inter Digital Transducer) are formed on the top of the diamond thin film. And a piezoelectric thin film is formed on the top of the diamond thin film, and is located above or below the first and the second metallic thin film pattern. A surface roughness of the diamond thin film where the first and the second metallic thin film are formed is in the range of 2-10nm.