| 摘要 |
PURPOSE:To acquire a high breakdown strength and to realize a large diameter of a substrate by making a P-N junction side on a first semiconductor substrate flat at a peripheral section thereof forming a mesa structure with a specified incline and by coating the incline with an insulator layer which consists of a thermal oxidation film. CONSTITUTION:At first, a mirror surface 1a of a first semiconductor substrate 1 of high resistance N<->-type is provided with a mesa groove 3 which is formed crosswise having an incline 3a and opens to a substrate edge. The semiconductor substrate and a low resistance second semiconductor substrate 2 of N<+>-type are fully cleaned to remove a spontaneous oxide film thereon. Then, an amount of water on the surface is controlled, and mirrors 1a, 2a are tightly bonded each other and dried. The substrates 1, 2 are directly bonded at a bonding side through heat treatment to acquire a completely integrated substrate 5. The substrate 5 is thermally treated to protect the incline 3a of the mesa groove 3 by an oxide film 6. The substrate surface 1b is lap-polished, a P-N junction surface 7 and a P-layer are formed, a mask is applied, an N<+>-layer is formed, and an aluminum wiring is applied to a specified position of the element surface. Dicing is carried out at a position of the mesa groove 3. |
