SEMICONDUCTOR DEVICE AND FABRICATION METHOD THEREOF

摘要

A semiconductor device and its fabrication method are provided to buffer and improve a hump characteristic by forming non-uniformity of ions for controlling a threshold voltage. A plurality of wells(13) are formed on an upper surface of a substrate(11). An ion layer for controlling a threshold voltage is formed around surfaces of the wells. An isolation layer(15) is disposed between the wells. An ion compensation layer(19) is formed on an edge surface and a bottom surface of the isolation layer. A gate(17) is formed on each of the wells. The ion compensation layer is formed with the same ions as the ions of the wells. The density of the ions of the wells is higher than the density of the ions of the ion compensation layer.