| 摘要 |
PROBLEM TO BE SOLVED: To provide an SiGe photodiode which has high photoelectric conversion efficiency and is excellent in operating characteristics at high frequencies.SOLUTION: An SiGe photodiode 100 includes: a p-type semiconductor layer 102 which has a first region 102a and a second region 102b positioned under the first region 102a; an i-type semiconductor layer 103 formed on the first region 102a of the p-type semiconductor layer 102; and an n-type semiconductor layer 104 formed on the i-type semiconductor layer 103. The impurity concentration of the first region 102a is lower than that of the second region 102b. |
