| 摘要 |
PURPOSE:To reduce the balck level signal at photo emission, by making the impurity concentration for the substrate thinner at the surface and dense at the inside, and reducing the component, among the carrier produced, going to the charge transfer section by light. CONSTITUTION:A high concentration impurity region 13 is located beneath a depletion layer 10. Thus, the trapping center increases much and the diffusion length of carrier is shorter inversely proportional to the concentration of impurity, allowing to avoid the light production carrier from being reached to the depletion layer of the charge transfer section. Accordingly, even if a substrate less in the crystal failure is used, the black level signal the same as at dark can be output. As a method to provide the region 13, a 5 volt of voltage is fed to the gate electrode 9 at the substrate concentration, and the spread of a depletion layer 10 is about 0.1mum from the surface of the substrate, then boron can be ion-injected with 400KeV and about 1X10<12>/cm<2> in dose. This high concentration region need to be provided at a region deeper than 17mum from the surface of the substrate 5 at least. |
