Effects of hydrogen atoms on postannealing of phosphorus-ion implanted silicon

The ion implantation process used in silicon device processing needs a postannealing at as high as 1000 °C to recover the damages induced by high-energy ion bombardment and to electrically activate implanted impurities. We developed a postannealing treatment using remote-hydrogen plasma to reduce the annealing temperature. We found that our postannealing treatment more greatly reduced the resistivity of the surface region, which was very high just after implantation. The dependence of resistivity-reduction rate on annealing temperature was weaker for the annealing with hydrogen plasma than for the normal annealing. Therefore the enhancing effect by hydrogen was remarkable at lower temperature in the range of 250–350 °C. The less the dose quantity was, the stronger the enhancing effect was observed. The postannealing using hydrogen plasma with the power of 50 W at 300 °C for 2 h showed almost the same performance as the usual rapid thermal annealing process at 1000 °C for 30 s.