| 摘要 |
PURPOSE:To facilitate manufacture, and to stabilize bidirectional characteristics by forming two different P-N junctions in the forward direction and the reverse direction to one surface of one semiconductor element and interposing a polycrystalline silicon layer in an electrode on one surface side. CONSTITUTION:A plurality of N type regions 18 are formed collectively on the surface side of one P type semiconductor wafer 25. A P type impurity is pushed in and diffused selectively from the surface of the semiconductor wafer 25 to collectively form a plurality of P type guard ring regions 19', 20', and P type regions 19, 20 are shaped collectively in each guard ring region 19', 20' under the same conditions. A back electrode 24 is formed on the whole region of the back of the semiconductor wafer 25, polycrystalline silicon layers 22 are attached onto P type region 19 exposed surfaces of the surface and insulating protective films 21 in the surroundings of the exposed surfaces, an impurity is doped so that the characteristics of first and second P-N junctions J1, J2 are made the same, and resistance value is set. Bump electrodes 23 are each formed collectively on the P type regions 19, and the semiconductor wafer 25 is divided finely at every semiconductor element 17 from the arrows of broken lines. |
