| 摘要 |
PURPOSE:To enable to effectively generate a breakdown at the light-receiving part of the titled element by a method wherein, pertaining to the channel stopper structure of an avalanche photo diode, the substrate surface outside a guard ring is covered by a channel stopper, and the surface leak current of the element is reduced by forming the difference in the density of the stopper. CONSTITUTION:An N type impurity layer 2 is formed on the prescribed region located on the surface of an N type Ga 1 by performing an As ion implantation. A P type impurity injection layer 3 is formed by ion-implantation of an In. Subsequently, in order to form a guard ring region, a P type impurity injection layer 4 is formed on the circumferential region of the layer 3 by implanting an As ion. Then, in the first region 5, the quantity of As ion implantation is set at 10<12>cm or 10<13>cm<-2>, as As ion of 1X10<14>cm<-2> or thereabout is used in the second region 6, and the ion is diffused by performing a heat treatment, thereby enabling to form a P<+> layer 7, a P layer 8, an N layer 9 and an N<+> layer 10. The distribution of the impurity density in the horizontal junction is formed in an inclined type, and this enables to give a higher withstand voltage by the junction of the P layer 8 and the N layer 9. |
