| 摘要 |
PURPOSE:To increase a charge amount detecting range by forming the same impurity layer as a potential barrier region on a charge transfer region under an output gate electrode. CONSTITUTION:An N-type charge transfer region 5 is formed on a P-type semiconductor substrate 1, and a P-type barrier region 6 is formed in the region 5. A P-type impurity region 11 having the same impurity concentration as that of the barrier region is formed on the region 5 under an output gate electrode 7. Further, an N-type floating diffused layer 8, an electrode 8 made of a polycrystalline silicon, an output transistor 10, and an N-type impurity layer 18 are formed. When a potential formed on a semiconductor surface by a voltage V2 applied to the electrode 7 is V2, the maximum charge amount Qmax allowable for the layer 8 of a capacity C is represented by Qmax=C(V1-V2). Thus, since the V2 is reduced by enhancing the impurity concentration of the region 11, the Qmax is increased.
|
