| 摘要 |
PURPOSE:To reduce a smear by making the junction depth of a drain section shorter than a photodiode section and forming a layer having concentration higher than a substrate to a section just under the drain section. CONSTITUTION:A drain 3 is formed through B implantation and As implantation, and a photodiode region 1 is shaped by P, thus shortening the N<+> type diffusion depth of a drain 3 section by a difference between diffusion coefficients and the effect of a B layer. A barrier by a P<+> type layer 4 having concentration higher than a P type substrate 5 is formed just under the drain 3. Accordingly, the quantity of electrons diffused from the lateral direction to the drain 3 section is reduced, thus minimizing the quantity of a smear. |
