| 摘要 |
<P>PROBLEM TO BE SOLVED: To realize mixed loading of a photodiode having high-speed/high-optical reception sensitivity with respect to a short wavelength light and a high-speed transistor on the same semiconductor substrate. <P>SOLUTION: This optical semiconductor device is provided with a p-type silicon substrate 1 of a low concentration, an n-type epitaxial layer (second epitaxial layer) 26 of a low-impurity concentration, a p-type anode layer 27 of a low-impurity concentration, an n-type cathode contact layer 9 of a high concentration; a photodiode 2 consisting of the anode layer 27 and the cathode contact layer 9, and an npn transistor 3 formed on the n-type epitaxial layer 26. The peak of the impurity concentration of the anode layer 27 is set near an interface, between the silicon substrate 1 and the n-type epitaxial layer 26, and the anode can thereby be substantially completely depleted. Thus, in addition to the realization of high-speed/high optical sensitivity characteristics, the automatic doping from an embedded layer in the periphery can be suppressed, and a depletion layer can be stably formed on the anode. <P>COPYRIGHT: (C)2008,JPO&INPIT |
