| 摘要 |
PURPOSE:To prevent the occurrence the cracks in a water by a method wherein a mesa type triac is provided with a second layer of a second conductive type which is not only in contact with a mesa groove but also formed on a part of the surface of the second conductivity type first layer, where the second layer is smaller than the second conductivity type first layer in thickness and higher than impurity concentration respectively. CONSTITUTION:When a first conductivity type layer and a second conductivity type layer are formed on an N-type and a P-type semiconductor respectively, a mesa type triac is provided with the following; an N-type substrate 11; a mesa groove 15 formed on both the sides of the substrate 11 and coated with a glass passivation 16; a P<+>-gate diffusion layer 12 formed on the surface of the N-type substrate 11 not in contact with the mesa groove 15; N<+>-diffussion layers 14 formed on a part of the surface of the diffusion layer 12; and a P<+>-compensation diffusion layer 13 which is formed on a part of the surface of the P<+>-gate diffusion layer 12 and whose thickness is larger than that of the P<+> gate diffusion layer 12 and impurity concentration is 2-10 times as high as that of the layer 12. Therefore, the thickness of a wafer remaining after a mesa groove is formed can be made large keeping the wafer excellent in breakdown strength without varying it in a current property or the like and the wafer can be protected from cracks. |
