| 摘要 |
PURPOSE:To reduce smear-blooming by a method wherein an N-layer, a P-layer and an I-layer are formed between an electronic N<+> type accumulating layer formed by photoelectric conversion and a P<+> barrier against electronic current toward deeper layers. CONSTITUTION:An N type Si substrate 1 is implanted with B ion to form a P- layer 2 making thin under sensing element 4 while thick under transmitting region and amplifier. An I buffer layer 3 is epitaxially formed to provide an N<+> layer 4', an N<+> type vertical transmitting resistor 6, a P type reading gate 7 and a P<+> type channel stopper 5 burying a transmitting electrodes 9 in an SiO2 layer 8. In such a constitution, the barrier heights X2-X1 may be increased without decreasing the impurity concentration of barrier wall P-layer 2 due to existence of a buffer layer 10. Therefore a vertical type overflow image sensor with least blooming-smear may be produced since the charge accumulated on the sensing element 4 is reduced after starting overflow without changing the barrier height X2 due to the increase in accumulated charge of sensing element 4. |
