SEMICONDUCTOR DEVICE HAVING STRESSOR AND METHOD OF FORMING THE SAME

The present invention relates to a semiconductor element having a stressor. An element separation film, defining an active area, is formed on a substrate. A gate electrode is formed in the active area. A trench, which is formed in the active area abutted on the gate electrode, and has first and second side walls, is arranged. A stressor is formed in the trench. The first side wall in the trench is close to the gate electrode, and relatively far from the element separation film. The second side wall of the trench is close to the element separation film, and relatively far from the gate electrode. The second side wall in the trench has a step shape.