| 摘要 |
PURPOSE:To eliminate the variance of the maximum stored charge quantity, by forming a semiconductor layer of the same conduction type as a semiconductor substrate on said substrate, and forming a well region of the conduction type different from the semiconductor layer also on the semiconductor layer. CONSTITUTION:An n type semiconductor layer 13 is formed on an n type semiconductor substrate 1 by an epitaxial growing process, and a p well 2 is formed on the layer 13. An image pickup device is formed on the well 2. The thickness of the layer 13 is set larger than a depletion layer extending toward the side of the layer 13 of a p-n junction between the well 2 and the layer 13. In general, a semiconductor layer obtained by the epitaxial growing process has uniform density of impurity. As a result, the variance is eliminated for the potential barrier, and the variance of the maximum stored charge quantity is also eliminated for the signal charge of the storing region 3. Thus a reproduced picture with high quality is obtained. |
