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.