Sub-100-nm p+-n shallow junctions fabricated by group III dual ion implantation and rapid thermal annealing

Abstract

The fabrication of p+-n junctions with depth less than 100 nm using dual ion implantation of group III species (69Ga, 115In, 11B, 49BF2) in various combinations is reported. We have investigated both the single use of heavy group III (Ga and In) ions for creating shallow junctions and the dual implant approach where Ga or In was first used for preamorphization (and doping) followed by a B or BF2 implant. The optimum cases for sub-100-nm shallow junction formation among the group III combinations evaluated are Ga/B dual ion implantation followed by low-temperature (550–600 °C) rapid thermal annealing (RTA) for 15–30 s and In/B(B or BF2) dual ion implantation with higher temperature (900–1000 °C) RTA for 10 s. Junction depths of 60–100 nm and sheet resistances of 150–300 Ω/⧠ were obtained. Shallow junction diodes fabricated by this dual ion implant technology exhibit low leakage current densities of 8–30 nA/cm2 and good ideality factors of 1.01–1.05.