| 摘要 |
<p>A cavity 44 is provided in a substrate 42 so as to penetrate from a front surface to a back surface of the substrate. A thin-film diaphragm 43 for sensing acoustic vibrations above the substrate 42 is provided over the cavity 44. At least one wall surface of the cavity 44 is configured of a first inclined surface 47a between the front surface of the substrate 42 and a middle portion in the thickness direction, the first inclined surface 47a gradually widening toward the outside of the substrate 42 as the first inclined surface 47a goes from the front surface of the substrate 42 toward the middle portion, and a second inclined surface 47b between the middle portion and the back surface of the substrate 42, the second inclined surface 47b gradually narrowing toward the inside of the substrate 42 as the second inclined surface 47b goes from the middle portion toward the back surface of the substrate 42. The width of the back surface opening of the cavity 44 is smaller than the width of the front surface opening of the cavity 44.</p> |
