| 摘要 |
PROBLEM TO BE SOLVED: To accurately measure crystal resonator width without providing a complicated process by providing an opening part in a protective film and using an observing means such as an infrared microscope when etching is performed form the opening part. SOLUTION: A protective film 200 composed of amorphous silicon is formed around a crystal substrate 100 (a). Next, an opening part 300 is formed in the film 200 (b). Since etching fluid comes into contact with the substrate 100 from the part 300, etching is available from the part of the opening part 300. As etching advances, the under part of the film 200 is etched and the protective film becomes the eaves of the roof of a house (c). The etching ridge line 110 of the substrate 100 can be observed through the film 200 by using an infrared microscope using wavelength in an infrared region, it is possible to measure the dimension of crystal resonator width in the middle of etching. Finally, a crystal resonator piece 400 is formed (d) by peeling off the film 200. |
