摘要 |
A third semiconductor layer 14 is formed on a light receiving surface 13a of a second semiconductor layer 13 so as to cover the light receiving surface 13a of the second semiconductor layer 13 at least partially in a plan view. A first semiconductor layer 10 is formed on an opposite surface of the light receiving surface 13a of the second semiconductor layer 13 so as to overlap the light receiving surface 13a and the third semiconductor layer 14 at least partially in a plan view. In the second semiconductor layer 13, the relative light receiving sensitivity to respective wavelengths of light has the highest value at a wavelength in an infrared region. Thus, even if the intensity of light of the infrared region that is emitted to an object of detection is not increased when sensing by a photodiode is performed using light of the infrared range, it is possible to achieve a photodiode that has a high S/N ratio, which is a ratio of data of received light with respect to noise, and that has high detection accuracy.
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