High quality shallow p+-n junction formation by employing BF2/low energy 11B mixed ion implant process

BF₂/low energy ¹¹B mixed ion implantation has been investigated as a new method of forming high quality shallow p ⁺-n junctions and compared with other methods such as conventional BF₂ ion implantation and ⁷³Ge pre amorphization prior to ¹¹B or BF₂ implantation. The mixed ion implantation produced significantly lower junction leakage current than the conventional BF₂ ion implantation and the ⁷³Ge preamorphization process, which is attributed to reduction of implantation-induced damage while maintaining the advantage of BF₂ ion implantation. In addition, the sheet resistance of p⁺-n junction and saturation current of a short channel PMOSFET were improved without causing any other deteriorative effect on transistor performance