| 摘要 |
PURPOSE:To provide high degree of freedom on design and manufacture and keep the noise and dark current low by a method wherein a PN-junction for multiplication is formed near a boundary of a surface layer and a multiplication layer or in the multiplication layer. CONSTITUTION:An n-type activated layer 9 of InGaAsP, an n-type multiplication layer 10 of InP and a n-type surface layer 11 of InP are formed successively on a n-type substrate 8 of InP. Then a PN-junction 13 for multiplication is formed near the boundary of the layer 10 and the layer 11 in the photodetector region or at the position deeper than the boundary. With above process, no intermediate layer exists and the position of the PN-junction can be determined considerably freely. Practically the parameter is only one, which is the carrier density of the multiplication layer, so that significantly high degree of freedom can be obtained. |
