| 摘要 |
PURPOSE:To reduce the capacitance at an electrode part including a wiring and connecting region, to increase the output electric power of a signal and to reduce the lowest level of reception by a method wherein an InP layer and a mixed-crystal semiconductor light.absorbing layer are constructed to be a planar structure which is buried into a semi-insulating InP layer at the outside of a light-receiving region. CONSTITUTION:After an i(nu)-type InGaAs layer 2 and an n-type InP layer 3 have been grown epitaxially on an n<+> type InP substrate 1, this assembly is etched by installing a circular mask so that a mesa-shaped light-receiving region can be formed. Then, InP buried layers 4 which are doped with, e.g., iron (Fe) at a concentration of about 1X10<15>cm<-3> are grown epitaxially at etched regions outside this mask. This Fe forms a deep acceptor-level, and the InP buried layers 4 become semi-insulating layers. Then, a p-type region 5 is formed in such a way that it reaches the InGaAs layer 2; an antireflection film 7 is then formed so that the regions near the outer circumference of openings at stabilizing insulating films 6 can become contact holes of p-side electrodes 8. The p-side electrodes 8 are formed on the contact holes; a bonding pad part 8' is formed on the semi-insulating InP buried layer 4; an n-side electrode 9 is formed on the reverse side of the substrate 1. |
