| 摘要 |
PROBLEM TO BE SOLVED: To provide a device which is lessened in capacitance so as to operate at a high speed and possessed of an active region and a passive region that are small in optical loss and high in coupling coefficiency between them. SOLUTION: A mask of SiO2 film which is wide in an active region, narrow in a passive region, and possessed of a gap constant in width is formed on an N-InP substrate 1. A waveguide structure composed of an N-InGaAsP guide layer 2, an undoped InGaAsP light waveguide layer 3a, and a P-InP clad layer 4 is selectively grown in a waveguide region sandwiched between the masks through an MOVPE method. A mask of SiO2 film is formed on the surface of the P-InP clad layer 4 in the active region, and two masks of SiO2 film are formed so as to sandwich the waveguide structure between them, and a high-resistance InP layer 11a is grown. Furthermore, a P-InP layer 5 and a P-InGaAs contact layer 6 are selectively grown in the active region, an SiO2 film 21 is formed, a window is provided, a P-side electrode 22 is formed, and an N-side electrode 23 is formed on the rear of the substrate. |
