| 摘要 |
<p>PURPOSE:To reduce a fluctuation in an output signal due to the electrostatic coupling between a light-emitting element and a photodetector for an optical- coupling semiconductor device, to reduce a malfunction and to increase the light-receiving current of the photodetector. CONSTITUTION:A p<+> diffused layer 20 and an n<+> diffused layer 19 are formed on the cross-sectional upper layer of a photodiode part for a photodetector, the diffused layers 19, 20 are used as an electromagnetic shield 6, and the electromagnetic shield 6 is connected directly to a ground or a power-supply voltage terminal in a light-receiving circuit. In addition, when a photodiode which is formed newly by adding the diffused layers 19, 20 is connected in parallel as far as possible, the light-receiving current of the photodiode part is increased.</p> |
