| 摘要 |
PROBLEM TO BE SOLVED: To reduce the resistances of metal electrodes through the reduction of surface barriers by reducing the surface levels of GaN contact layers by interposing thickness-controlled high-purity surface oxide films between the GaN contact layers and metal electrodes. SOLUTION: A GaN semiconductor layer provided with an ohmic electrode is constituted of an InGaN multi-quantum well active layer 6, light guide layers 5 and 7 which are respectively formed below and on the active layer 6, clad layers 4 and 8 which are respectively formed below and on the light guide layers 5 and 7, and contact layers 2 and 9 which are respectively formed below and on the clad layers 4 and 8. The semiconductor layers composed of a multilayered structure of GaN crystals is formed on a sapphire substrate 1, but current electrodes 3 and 11 are led out from one side of the laser, because the substrate 1 is made of an insulator. Current electrode structures containing interpose oxide films are respectively applied to the layers between the upper p-type GaN contact layer 9 and a Pt/Au electrode 11 and between the lower n-type GaN contact layer 2 and an Al/Pt/Au electrode 3. Therefore, a highly efficient GaN semiconductor laser having a long service life can be realized, because the operating voltage of the laser can be lowered. |
