Abstract: A process for manufacturing a MOS device and the MOS device manufactured thereby are disclosed. The process includes in a semiconductor layer forming a gate structure above the semiconductor layer; forming a first doped region within a first surface portion of the semiconductor layer; and irradiating the first doped region with electromagnetic radiation, to carry out annealing thereof. Prior to the irradiating step, a dielectric mirror is formed above a second surface portion of the semiconductor layer. The dielectric mirror, which may be of the Bragg-reflector type, reflects at least in part the electromagnetic radiation, and protects underlying regions from the electromagnetic radiation.

Abstract: A semiconductor power device has a semiconductor body with a first conductivity type. A trench extends in the semiconductor body and accommodates an insulating structure, which extends along the side walls and bottom of the trench. The insulating structure surrounds a conductive region, arranged on the bottom of the trench, and a gate region, arranged on top of the conductive region, the conductive region and the gate region being electrically insulated by an insulating layer. A body region, with a second conductivity type, extends within the semiconductor body, at the sides of the trench, and a source region, with the first conductivity type, extends within the semiconductor body, at the sides of the trench and within the body region. The conductive region and the gate region are both of polycrystalline silicon but have different conductivities and doping levels so as to have different electrical characteristics such as to improve the static and dynamic behaviour of the device.