The effect of low-energy ion-implantation on the electrical transport properties of Si-SiO2 MOSFETs

. Using silicon MOSFETs with thin (5nm) thermally grown SiO 2 gate dielectrics, we characterize the density of electrically active traps at low- temperature after 16keV phosphorus ion-implantation through the oxide. We find that, after rapid thermal annealing at 1000oC for 5 seconds, each implanted P ion contributes an additional 0 . 08 ± 0 . 03 electrically active traps, whilst no increase in the number of traps is seen for comparable silicon implants. This result shows that the additional traps are ionized P donors, and not damage due to the implantation process. We also find, using the room temperature threshold voltage shift, that the electrical activation of donors at an implant density of 2 × 10 12 cm − 2 is ∼ 100%.