| 摘要 |
PURPOSE:To improve and stabilize element characteristics, by forming insulating films by combining an amorphous or polycrystalline silicon film and an Si3N4 film or an SiO2 film on the surface of an InP crystal base body, and constituting a P-type crystal layer with the insulating films as masks. CONSTITUTION:On an N-type InP substrate 11, an N-type InP layer 12, an N-type InGaAs absorbing layer 13, an N-type InGaAsP buffer layer 14, and an InP multiplying layer 15 are formed. A circular mesa, which is to become a light receiving part, is provided. An InP guard layer 16 is formed. Thus a base body is constituted. P-type impurity ions such as Mg and Be are selectively implanted in the main surface of the base body 100. A P-type guard ring 171 is provided by heat treatment. Then an amorphous silicon layer 181 and silicon oxide layer 182 are formed so as to cover an exposed P-N junction 172 and to expose the main surface on the light receiving part and made to be the first insulating films. With the layers 181 and 182 as masks, Zn or Cd is selectively diffused and a P-type light receiving surface 173 is formed. Second insulating films 19, 191 and 192 are selectively formed. |
