| 摘要 |
A narrow mesa region of ?tripe geometry is formed on a GaAs cyrstal substrate. A crystal layer of higher resistivity than the substrate is located around the mesa region, the top faces of these regions being flush with each other. On these top faces there is thus formed a lightemitting assembly consisting of several epitaxial growth regions of semiconductor crystal, including an active region for lasing. Subsequently there is formed a contact isolation region having an opening with the ?ame stripe geometry as the mean region. Finally, on the contact isolation region there is formed a metal electrode contacting the uppermost layer of the epitaxial growth regions through the stripe-geometry opening. Current flows from the stripe-shaped portion of the upper electrode to the similar stripe-shaped narrow mesa region in a narrow concentrated path. As a result the effective lasing region is sufficiently concentrated to enable lasing with a low threshold current. Furthermore, since insulation films, such as SiO2 films, are not used for contact isolation, and the regions around the active region have sufficiently large area ail the way across the substrate, almost no strain is set up in the semiconductor crystal around the active region thereby assuring long life with stable ?unction. |
