ULTRASHALLOW JUNCTIONS FOR ULSI USING AS-2+ IMPLANTATION AND RAPID THERMAL ANNEAL

Using As2+ ion implantation and rapid thermal anneal, 40-nm n+-p junctions are realized. The junction formed with p- substrate shows very low leakage current (< 0.5 nA/cm2) up to 2-V reverse bias. The introduction of a heavily doped (10(18) cm-3 level) p region generates a significantly higher leakage current due to the onset of band-to-band tunneling. Using varied geometry devices with a given area, the major tunneling current is shown to be confined in the perimeter of the device, and a method to suppress this leakage is suggested.