| 摘要 |
PURPOSE:To eliminate the variance of sensitivity at a photodeecting part, by applying the backward bias to a P-N junction formed between an impurity region and a semiconductor substrate and preventing the minor carrier caused at the peripheral part of the P-N junction from entering the photodetecting part. CONSTITUTION:An impurity region 5 having a conduction type opposite to a semiconductor substrate is formed on the 1st main surface between a photodetecting part 3 and a peripheral part 2, and the backward bias is applied to a P-N junction formed by the region 5 and the semiconductor substrate. First the semiconductor substrate is formed P type, and as a result the region 5 is N type. Therefore the positive voltage is applied to the region 5 to the semiconductor substrate. Then the electrons produced at a peripheral part 2 are almost absorbed while they pass under the region 5 and before they enter the part 3 since the region 5 has the lower potential than the semiconductor substrate to the electron. Thus the electrons produced at the part 2 never enter the part 3. At the same time, the apparent variance of sensitivity can be eliminated for the part 3. |
