| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce transmission loss by applying thin coating material onto diamond surface, exposing inspection light thereon, reflecting the inspection light on coating material surface and the boundary between the coating material and the diamond, measuring the scattered inspection light by surface defect and keeping the obtained surface discontinuity density to a specific value or below. SOLUTION: A diamond film having >=1μm thickness, >=19 cm<2> area, <=1.5×10<8> Pa and <=±40μm warping is formed on an Si substrate having 0-2,000μm thickness. Then, the diamond film is polished and made flat by electrodepositing grinding stone so as to have <=10 nm surface roughness Rc and a metal material having high reflectivity, e.g. Al is subjected to vapor deposition to form a film having <=100 nm thickness and the film is inspected by a laser scanning type surface discontinuity inspecting apparatus to provide a diamond film having <=300 numbers/cm<2> surface discontinuity density. Piezoelectric thin film of ZnO or the like is subjected to vapor deposition onto the passed substrate and comb-shaped electrode is further formed thereon to provide the objective surface acoustic wave element.</p> |
