| 摘要 |
PURPOSE:To improve the detecting sensitivity by forming an FD layer apart from the end of the field oxide film containing a GR layer in the lower layer thereof, thereby making the junction capacitance small. CONSTITUTION:A transfer gate phi2, an output gate OG and a reset gate phiR are formed on a P-type silicon substrate 1 through a gate oxide film 2, and a P<+> type GR layer 6 and a field oxide film 5 are provided surrounding an active region 7. An FD layer 3 formed simultaneously with a drain region 8 and composed of an N<+> type impurity layer is formed narrowly in the width W'. Capacitance C41 formed by the N<+> type FD layer 3 and the GR layer 6 becomes extremely small, and capacitance C31 formed by the FD layer 3 and the silicon substrate 1 also reduces. Therefore, the total capacity CFD formed by the FD layer 3 becomes extremely small as compared with that of the conventional structure, so that the detecting signal DELTAV becomes greater, and the detecting sensitivity improves.
|
