| 摘要 |
PURPOSE:To prevent a laser chip and a heat sink from exfoliating without leakage current flowing even if a pinhole is generated in an SiO2 film, by forming a p-n reverse junction with the first and second buried layers on the upper portion of an external waveguide layer. CONSTITUTION:After an etching protective film is formed on the right half of the upper surface of a layer D, it is removed to the upper surface of a clad layer 22 by selectively etching. Then, a diffraction grating 25 is formed by etching on the upper surface of the exposed layer 22, and an external waveguide layer 14 and a clad layer 28 are sequentially liquid-phase grown thereon. Then, a strip SiO2 film E is formed on the upper surface, selectively etched to the upper surface of the layer 22 to form a stripe structure ST. Then, the oblique part of the structure ST and the SiO2 film of the upper portion of the layer 24 are removed, and the film E remains only on the active waveguide. Then, p-InP first buried layer 29, then n-InP second buried layer 30 are liquid-phase grown. In this case, the upper surface of the layer 30 is formed substantially on the same plane as upper surface of the layer 27. |
