A device includes a semiconductor substrate, a body region in the semiconductor substrate having a first conductivity type and in which a channel is formed during operation, source and drain regions in the semiconductor substrate and having a second conductivity type, the source region being disposed on the body region, and a composite drift region in the semiconductor substrate, having the second conductivity type, and through which charge carriers from the source region drift to reach the drain region after passing through the channel. The composite drift region includes a first section adjacent the channel, a second section adjacent the drain region, and a third section disposed between the first and second sections. The first and second sections have a lower effective dopant concentration level than the third section.