Patent attributes
A device isolation film is formed in a semiconductor substrate at a border portion between a first region and a second region for defining a first active region in the first region and a second active region in the second region. A gate insulating film and a gate electrode is formed over the semiconductor substrate in the first region. A first photoresist film covering the second region and having an opening exposing the first active region and having an edge on the border portion of the opening positioned nearer the second active region than a middle of the device isolation film is formed over the semiconductor substrate with the gate electrode. Impurity ions are implanted from a direction tilted from a normal direction of the semiconductor substrate with the first photoresist film and the gate electrode as a mask to form pocket regions in the semiconductor substrate on both sides of the gate electrodes.