A semiconductor device and a method of fabricating same are provided. According to an embodiment, a gate insulating layer and a gate are sequentially formed on a substrate, and a pocket ion implant region is formed at sides and below a portion of the gate at a predetermined depth in the substrate. An LDD ion implant region can be formed between the pocket ion implant region and the surface of the substrate. A spacer is formed on sides of the gate, and a deep source/drain region is formed by ion-implanting BF2 within the substrate at sides of the spacer.