| 摘要 |
PURPOSE:To realize high signal-to-noise ratio without using an optical filter and the like, by arranging a capture region to capture electron-hole-pairs generated by an incident light, in the vicinity of the surface of a photo detection semiconductor device in which a second conductivity type semiconductor layer is formed on a first conductivity type semiconductor layer. CONSTITUTION:A capture region 15 to capture electron-hole pairs generated by an incident light is arranged in the vicinity of the surface of a photo detection semiconductor device in which, on a first conductivity type semiconductor layer 10, a second conductivity type, i.e., the inverse conductivity type, semiconductor layer 11 is formed. For example, an n<+> type diffusion layer 18 is formed in the vicinity of the surface of an n<-> type epitaxial growth layer 11 on a P<-> type semiconductor substrate 10, and the capture region is constituted which captures the electro-hole pairs generated by an incident light 12B of short wavelength. Thereby, the sensitivity for a short wavelength light acting as noise can be restricted in a low range, while the sensitivity for a long wavelength light serving as light signal is maintained in a high range. Therefore, high signal-to-noise ratio can be realized without specially arranging an optical filter and the like. |
