Publications

Effect of B+ Flux on the electrical activation of ultra-shallow B+ implants in Ge

Yates, B.R.; Darby, B.L.; Petersen, D.H.; Hansen, O.; Lin, R.; Nielsen, P.F.; Doyle, Barney L.; Kontos, A.; Jones, K.S.

The residual implanted dose of ultra-shallow B+ implants in Ge was characterized using elastic recoil detection and was determined to correlate well with simulations with a dose loss of 23% due to ion backscattering for 2 keV implants in Ge. The electrical characterization of ultra-shallow B+ implants at 2 keV to a dose of 5.0×1014 cm-2 at beam currents ranging from 0.4 to 6.4 mA has been studied using micro Hall effect measurements after annealing at 400°C for 60 s. It has been shown that the sheet number increases with beam current across the investigated range with electrical activation being 76% higher at 6.4 mA as compared to 0.4mA. However, at 6.4 mA, the electrically active fraction remained low at 11.4%. Structural characterization revealed that the implanted region remained crystalline and amorphization is not able to explain the increased activation. The results suggest the presence of a stable B:Ge cluster whose formation is altered by point defect recombination during high flux implantation which results in increased B activation. © The Electrochemical Society.