SEMICONDUCTOR LIGHT RECEIVING DEVICE, AND MANUFACTURE THEREOF

摘要

PROBLEM TO BE SOLVED: To provide a semiconductor light receiving device which can reduce trailing phenomena of a current. SOLUTION: A light absorbing layer 3 is arranged on the surface of a substrate 1. A cap layer 4 is arranged on the surface of the light absorbing layer 3. First conductivity impurities are added in advance to the cap layer 4. Second conductivity impurities are added in advance to the light absorbing layer 3 and the cap layer 4 under the first region within the surface of the cap layer 4, thereby making it into a second conductivity. The difference between the concentration of the second conductivity impurities within the cap layer 4 and the concentration of the first conductivity impurities is higher than the concentration of the of the second conductivity impurities in one part at least on board 1 side within the light absorbing layer 3. The light absorbing layer and the cap layer 4 under the second region surrounding the first region are of the first conductivity. The light absorbing layer 3 and the cap layer 4 under the third region surrounding the second region are of the second conductivity, and the distribution of the impurity concentration in its thickness direction is roughly equal to that under the first region.