Method of fabricating a reverse mesa ridge waveguide type laser diode

摘要

The present invention provide a reverse mesa ridge waveguide type laser diode and a method of fabricating the same. A laser diode according to the present invention includes: a compound semiconductor substrate of a first conductivity type having an upper surface and a lower surface opposite the upper surface; a buffer layer of the first conductivity type, an active layer and a waveguide layer of a second conductivity type which are sequentially formed on the upper surface of the substrate; a waveguide control layer of the second conductivity type formed on the waveguide layer and having a predetermined width; a clad layer of the second conductivity type and a contact layer of the second conductivity type sequentially formed on the waveguide control layer and having a shape of a reverse mesa ridge whose lower portion has wider width than width of the waveguide control layer; a protection layer formed on the upper surface of the substrate, exposing the contact layer in an upper portion of reverse mesa ridge and protecting the reverse mesa ridge; a polyimide layer formed on the protection layer and filling both side portions of the reverse mesa ridge; an ohmic metal layer of the second conductivity type formed on the substrate and contacted with the exposed portion of the contact layer; and an ohmic metal layer of the first conductivity type formed on the lower surface of the substrate.