| 摘要 |
PURPOSE:To obtain the titled device of high resolving power by a method wherein the distance of reaching diffusion of a charge carrier is selected so as to be short enough with respect to the interval between photosensitive regions, and a region of reverse conductivity type to that of a substrate which region is diffused in the substrate is composed of a region of relatively high impurity concentration and a region of low concentration surrounding it. CONSTITUTION:The substrate 20 is an N type Si substrate containing phosphorus at a concentration of e.g. 1X10<17>atom/cm<3>, with an oxide film 21 adhered to one main surface and windows 21a bored by photoetching. Next, boron is diffused to a depth of 2-3mum at a concentration of e.g. 5X10<17>atom/cm<3> through the windows 21a, resulting in the formation of P-layers 22 as the second regions. It is appropriate that the impurity concentration in the P-layer 22 is in a range of 1X10<17>-1X10<18>atom/cm<3>. Further, boron is diffused to a depth of 1mum at a concentration of e.g. 5X10<15>atom/cm<3>, which is higher impurity concentration as the first region, P<+> layers 23 thus being formed, and finally electrodes 4 are attached by Al evaporation. |
