Patent ID: 6340831
Filing Date: 2002-01-22
Classification: H01L

Abstract:
A photodiode module including optical transmission media and a photodiode chip for sensing light having a second wavelength of &lgr;2 longer than a first wavelength of &lgr;1 in an optical communication arrangement using light having wavelengths &lgr;1 and &lgr;2, comprising:a first conductive-type p- or n-type semiconductor substrate; a first conductive-type light receiving layer epitaxially grown on a surface of the semiconductor substrate; a second conductive-type p- or n-type region formed on a part of the light receiving layer by doping a second-conductive type impurity opposed to the first conductive-type semiconductor substrate; a pn-junction formed in the light receiving layer; a second conductive-type electrode formed on the second conductive-type region; a filter layer comprising n- or p-type semiconductor crystal epitaxially grown on the other surface of the substrate having a bandgap lower than &lgr;1 light and higher than &lgr;2 light in energy; and a first conductive-type ring electrode including an opening part and formed on the filter layer; wherein the &lgr;1 light and the &lgr;2 light pass through the opening part of the first conductive-type electrode, the &lgr;1 light is absorbed by the filter layer and the &lgr;2 light reaches the pn-junction of the light receiving layer, the photodiode chip is optically connected to the optical transmission media which are optical fibers, optical waveguides or optical guides via a lens or without a lens, the light emitted from the optical transmission media passes through the opening of the first conductive-type electrode of the photodiode and reaches the pn-junction of the light receiving layer.