Patent ID: 7253067

Claim:
A method of manufacturing a semiconductor device having a semiconductor substrate that includes an active region for forming transistor elements, which includes a gate, and element isolation regions for isolating the transistor elements separately each other, which have a STI structure, the method comprising; a first ion implanting step of implanting first ions onto the surface of the semiconductor substrate in a region other than stress regions in the active region, which are located at junctions of the active region and the element isolation regions on both sides of the gate, wherein, in the stress region, a potential stress is generated by forming the element isolation regions and/or the difference between a material of the element isolation regions and a material of the semiconductor substrate, so that a first impurity region for a source and/or a drain is formed in the active region in which the gate is not formed; and a second ion implanting step of implanting second ions each of which mass is smaller than that of each of the first ions so that a second ion impurity region is formed in the stress region, wherein after the second ion implanting step, source and drain regions include the second impurity regions.