Time evolution of donor activation at low temperatures with co-implantation of phosphorus and hydrogen in silicon

We report on the study of the donor activation behavior at low temperatures using subamorphizing implantation of phosphorus and hydrogen to develop three-dimensional integrated circuits. We show that the activation ef-ficiency of phosphorus 0 degrees implantation angle is superior to that at 7 degrees due to the broad defect and donor profiles. At 370 degrees C, the carrier concentration was enhanced by hydrogen co-implantation at a dose of 1015 cm-2. How-ever, the enhancement quickly decayed, and the carrier concentration at 400 degrees C was lower than that in the sample without hydrogen. The change in the activation behavior suggests that the enhancement in the carrier concentration was due to the defect complexes generated by hydrogen implantation. By eliminating defect complexes, the passivation of phosphorus by hydrogen atoms became evident. At 500 degrees C, hydrogen caused phosphorus deactivation at the beginning of the annealing process. The carrier concentration then recovered, indicating dehydrogenation during further annealing.

Automated summary

In this study, subamorphizing implantation of phosphorus and hydrogen was used to investigate the donor activation behavior at low temperatures for the development of three-dimensional integrated circuits. It was found that the activation efficiency of phosphorus at 0 degrees implantation angle was higher than that at 7 degrees due to the broader defect and donor profiles. Hydrogen co-implantation at a dose of 1015 cm-2 enhanced the carrier concentration at 370 degrees C, but the enhancement decayed quickly and the carrier concentration at 400 degrees C was lower than that without hydrogen. The change in activation behavior suggested that the enhancement in carrier concentration was due to defect complexes generated by hydrogen implantation.