SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD THEREOF

摘要

PROBLEM TO BE SOLVED: To provide a semiconductor device which suppresses a leak current between a vertical PN junction and a source layer.SOLUTION: The semiconductor device includes a gate insulation film 80 and a gate electrode 90 which are provided on a semiconductor substrate. A first diffusion layer 50 of a first conductivity type is provided in a part of a surface of the semiconductor substrate below the gate insulation film. A second diffusion layer 60 of a second conductivity type is provided in the semiconductor substrate further below the first diffusion layer and is in contact with a bottom of the first diffusion layer, thereby forming a PN junction with the bottom of the first diffusion layer. A drain layer 30 of the first conductivity type and a source layer 40 of the second conductivity type are provided in the semiconductor substrates at each side of the gate electrode, respectively. A first sidewall insulation film 100S is provided on a side surface of the gate electrode and a top surface of the first diffusion layer. A source silicide layer 120S is provided on the source layer at a position separated from the first sidewall insulation film. A top surface S40 of the semiconductor substrate in a separation region Rsep between the first sidewall insulation film and the source silicide layer is positioned at a level of a bottom S50b of the first diffusion layer or lower.SELECTED DRAWING: Figure 1