Improved germanium n+/p junction diodes formed by coimplantation of antimony and phosphorus

Abstract

Obtaining heavily-doped n-type germanium (Ge) is difficult since n-type dopant activation in Ge is limited to less than 5×1019 cm−3 which is far below the solid solubility limit of phosphorus (P) in Ge. Such poor activation has limited the rectifying properties of n+/p Ge diodes. This work is aimed at understanding the challenge of forming highly rectifying n+/p diode as well as enhancing rectification of n+/p diode by using antimony (Sb) and P coimplantation process. Enhanced n+ doping of greater than 1020 cm−3 in Ge obtained by Sb/P codoping results in enhanced rectification in Ge n+/p junction diode.