In an embodiment, a semiconductor device includes a semiconductor substrate having a bulk resistivity ρ≥100 Ohm.cm, a front surface and a rear surface, at least one LDMOS transistor in the semiconductor substrate, and a RESURF structure. The RESURF structure includes a doped buried layer arranged in the semiconductor substrate, spaced at a distance from the front surface and the rear surface, and coupled with at least one of a channel region and a body contact region of the LDMOS transistor.