Effects of Thermal Annealing on In Situ Phosphorus-Doped Germanium $\hbox{n}^{+}/\hbox{p}$ Junction

In this letter, we investigate the electrical behavior of vacancy
$V_{\rm Ge}$
defects in Ge at various thermal annealing conditions through electrochemical capacitance–voltage analysis. Then, the effects of the annealing process on Ge
$\hbox{n}^{+}/\hbox{p}$
junction diodes were also studied with
$J{-}V$
, transmission electron microscopy, and secondary ion mass spectroscopy measurements in the aspects of point-defect healing and dopant diffusion/loss phenomena. The
$V_{ \rm Ge}$
defects tend to heal by recombining with Ge interstitial atoms as the annealing process temperature increases. However, the diffusion/loss problems of P atoms in Ge become severe at above 500
$^{\circ}\hbox{C}$
. Therefore, an optimal postfabrication annealing process at 600
$^{\circ}\hbox{C}$
is proposed in terms of point-defect healing and dopant diffusion/loss reduction.