Patent ID: 8422834

Claim:
A semiconductor integrated circuit comprising: a semiconductor pattern disposed on a substrate and including an optical waveguide part and a pair of recessed portions, the optical waveguide part having the thickness ranging from about 0.05 μm to about 0.5 μm, the recessed portions disposed on both sides of the optical waveguide part having the thinner thickness than the optical waveguide part; a first doped region formed in an upper portion of the waveguide part and doped with a first conductive type dopant; second and third doped regions formed in the recessed portion, respectively, and doped with a second conductive type dopant; and an intrinsic region formed in the semiconductor pattern between the first, second, and third doped regions to contact the first, second, and third doped regions, wherein each of the recessed portions includes a first portion having a first thickness and a second portion having a second thickness, the first portion being disposed between the optical waveguide part and the second portion, the first thickness being less than the second thickness, and wherein the second and third doped regions are formed in the second portions of the recessed portions, respectively.