| 摘要 |
PURPOSE:To allow the effective utilization of the whole substrate without waste, by forming an electrode reaching the rear surface via the side surface of a compound semiconductor substrate and forming an anodic oxide film on the epitaxial layer of the substrate surface. CONSTITUTION:The epitaxial layer 1 is grown on the surface of the compound semiconductor substrate 2. Besides, the electrode for anodic oxidation 9 which is coupled to the layer 1 and reaches the back surface of the substrate 2 via the side surface of the substrate 2. This electrode 9 is coupled to the positive electrode of source side, and the negative electrode of the power source 4 is coupled to the negative electrode 6 for anodic oxidation. The substrate 2 and the electrode 6 are dipped into the solution for anodic oxidation 7. When positive potentials are impressed on the epitaxial layer 1 via the electrode 9 in this manner, an anodic oxide film 8 is formed over the entire surface of the layer 1. Thus, an anodic oxide film can be easily formed over the entire surface of the epitaxial layer 1 without damaging the surface cleaning effect on the epitaxial layer. |
