Germanium In Situ Doped Epitaxial Growth on Si for High-Performance $\hbox {n}^{+}/\hbox {p}$ -Junction Diode

We demonstrate an abrupt and box-shaped n⁺/p junction in Ge with a high level of activation of n-type-dopant phosphorus (P) using in situ doping during epitaxial growth. The temperature dependence of dopant activation was investigated associated with the shallower and abrupt junction formation. In addition, we have fabricated high-performance Ge n⁺/p-junction diodes at 400degC-600degC, based on the in situ doping technique. Excellent diode characteristics having a 1.1 times 10⁴ on/off ratio and a high forward current density (120 A/cm² at 1 V) are obtained in an n⁺/p diode at 600-C in situ doping.