| 摘要 |
PURPOSE:To realize a device easy to manufacture and provided with improved gain and signal/noise features by a method wherein a P-N juction is built in a second semiconductor layer formed on a first semiconductor layer and the second semiconductor layer is surrounded with a guard ring. CONSTITUTION:A recess is provided in a light-receiving section in an N type InP substrate 20 low in impurity concentration, which is followed by the formation of an N type InP buffer layer 21 and N type InGaAs light-absorbing layer 24. A process follows wherein an N type InP layer 25 relatively low in impurity concentration, guard ring 26, P<+> type region 27 to serve as the light-receiving, section, surface protecting film 28, P-side electrode 29 and N-side electrode 30 are formed. In a device designed as such, an avalanche breakdown may be easily triggered off in the light-receiving section when the light-receiving section voltage is adequately lower than that of the guard ring 26. |
