| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical sensor which offers a high S/N ratio by effectively utilizing the light to be detected.SOLUTION: The optical sensor comprises a substrate 1 and a semiconductor laminate section including a PN or PIN junction photodiode structure composed of a first mesa section 21 including a first conductive semiconductor layer 2 formed on a first surface 41 of the substrate 1 and a second mesa section 22 having at least a second conductive semiconductor layer 4 formed on the first mesa section 21, so that when light is incident upon the photodiode structure, the optical sensor generates a photoelectromotive force. A first mean square degree of roughness in a region of the surface 41 of the substrate abutting on the first mesa section 21 is smaller than a second mean square degree of roughness in a region not abutting on the first mesa section 21. Light enters from a second surface 42 of the substrate which faces the first surface 41. |
