| 摘要 |
PURPOSE:To materialize a photodetector having a small electric capacity by forming a first conductivity type semiconductor layer on an insulating substrate, and providing a second conductivity type semiconductor layer in the semiconductor layer to make a depletion layer arrive at the substrate. CONSTITUTION:An N-type semiconductor layer 2 is formed on an insulating substrate 8, and a P-type semiconductor layer 3 is formed in the layer 2. With this construction, since a depletion layer 4 arrives at the substrate 8, the surface area of the depletion layer which contributes to an electric capacity is effectively reduced. As a result, the electric capacity can be reduced. |
