| 摘要 |
PROBLEM TO BE SOLVED: To solve a problem that it is difficult to simultaneously improve the characteristics of a vertical PNP transistor and a photodiode incorporated in an optical semiconductor integrated circuit device, because these two elements have different characteristics on the same substrate. SOLUTION: In the optical semiconductor integrated circuit device incorporating the vertical PNP transistor 21 and photodiode 22, first and second epitaxial layers 24 and 25 are laminated upon another in a non-doped state. Consequently, a depletion layer forming area can be increased remarkably in the photodiode 22 and the response speed of the photodiode 22 can be increased. In the vertical PNP transistor 21, on the other hand, the forming area of the transistor 21 is surrounded by an N<SP>+</SP>-type diffusion region 38. Consequently, the withstand voltage characteristic of the transistor 21 can be improved significantly. COPYRIGHT: (C)2003,JPO
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