| 摘要 |
PURPOSE: A cmos image sensor with floating base read concept is provided to reduce an emitter leakage current by comprising a current sensing CDS circuit(Correlated Double Sampling Circuit) connected to an interface of a horizontal readout circuit. CONSTITUTION: A p type silicon board(201) is arranged on a p+ substrate(214). The p type silicon substrate includes a STI(Shallow Trench Isolation) domain(202) filled with a silicon dioxide(203). A P+ doped region(204) expands to the lower part of a floating base region(213) and offers a collector region(204A). A collector region, a emitter region(206) and the floating base region form a vertical type floating base bipolar transistor. Photo-charges are collected in a n-type doped region(205) of a pinned photodiode. An electric charge from the n-type doped region is transmitted to a full bridge region by instantaneously turning a gate(207) on.
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