| 摘要 |
PURPOSE:To improve controllability and reliability of element characteristics by implanting oxygen selective with a PEP in a nearby gate electrode and also by carrying out an ion implantation for the purpose of forming source and drain regions after activating added oxygen mentioned above. CONSTITUTION:In addition to the selective formation of a gate electrode 3 through a gate oxide film 2 at an element region of a semiconductor substrate 1, oxygen is added so as to have a peak value in the vicinity of an interface between the semiconductor substrate 1 and the gate oxide film 2 at the nearby gate electrode 3. Added oxygen is activated and the gate oxide film of the nearby gate electrode 3 is thickened. Impurities are implanted through this gate oxide film 5 and then, source 6 and drain 7 regions having a low concentra tion at a place that under the thick gate oxide film 5 situated at the nearby gate electrode 3 are simultaneously formed. Since the same structure as that of an LDD is realized and further its structure eliminates the need for carrying out an etchback process for oxide silicon, there is no possibility that the surface of substrate is etched and, therefore, reliable and excellent controllability of element characteristics of the semiconductor device is obtained. |
