A semiconductor transistor device is described that has a source region, a body region including a vertical channel region, a drain region, a gate region laterally aside the channel region, a body contact region formed by doping, a diffusion barrier layer, and a conductive region formed of a conductive material. The body contact region electrically contacts the body region, the diffusion barrier layer being arranged in between. The doping of the body contact region is of the same conductivity type but of higher concentration than a doping of the body region. The conductive region has a contact area that forms an electrical contact to the body contact region, the contact area of the conductive region being arranged vertically above an upper end of the channel region. A method for manufacturing the semiconductor transistor device is also described.