Abstract: A silicon controlled rectifier structure is provided in a substrate having a first conductive type. A well region formed within the substrate has a second conductive type. A first dopant region formed within the substrate and the well region has the first conductive type. A second dopant region formed within the substrate and a portion of the well region has the second conductive type. A third dopant region formed under the second dopant region has the first conductive type, in which the second and the third regions form a vertical Zener diode. A fourth dopant region formed within the substrate and separated from the second dopant region by a separation structure has the second conductive type. A fifth dopant region is formed within the substrate in a manner that the fourth dopant region is between the isolation structure and the fifth dopant region, and has the first conductive type.

Abstract: A silicon controlled rectifier structure is provided in a substrate having a first conductive type. A well region formed within the substrate has a second conductive type. A first dopant region formed within the substrate and the well region has the first conductive type. A second dopant region formed within the substrate and a portion of the well region has the second conductive type. A third dopant region formed under the second dopant region has the first conductive type, in which the second and the third regions form a vertical Zener diode. A fourth dopant region formed within the substrate and separated from the second dopant region by a separation structure has the second conductive type. A fifth dopant region is formed within the substrate in a manner that the fourth dopant region is between the isolation structure and the fifth dopant region, and has the first conductive type.