Well-behaved Ge n⁺/p shallow junction achieved by plasma immersion ion implantation

Ge n⁺/p junctions fabricated by conventional ion implantation (CII) and plasma immersion ion implantation (PIII) are compared in this work. To achieve low junction leakage current, PIII-implanted Ge n⁺/p junctions require higher annealing temperature to eliminate the Shockley-Read-Hall generation current, which may be contributed to the residual hydrogen and hydrogen-related defects. It is demonstrated that with 500 °C annealing, well-behaved Ge n⁺/p junction with ultra-shallow junction depth (<50 nm) can be achieved by PIII. With 600 °C annealing, best Ge n⁺/p junction performance with current on/off ratio ~9 × 10⁵ and ideality factor ~1.07 is achieved by PIII.