Kinetics and thermodynamics constraints in Pt gettering by P diffusion in Si

We have explored the mechanisms underlying the gettering of Pt atoms dissolved in crystalline Si. By using Pt implantation at different fluences followed by a thermal process at 970 °C for 5 h we were able to prepare crystalline silicon wafers containing a uniform Pt concentration in the range 2×1012–2×1014 atoms/cm3. Subsequently, a heavily doped n‐type region was produced on one side of the wafer by P diffusion at 900 °C. Following this deposition process we have studied the kinetics of Pt gettering to the P‐doped region in the temperature range 700–970 °C and for annealing times ranging from 30 min to 48 h. Lifetime measurements by means of a contactless technique were used to detect the depletion of Pt in the bulk of the wafer due to the gettering process. The large range of initial Pt concentrations that we have explored allowed us to identify and separate the kinetics and thermodynamics constraints that determine the gettering efficiency and to propose a phenomenological model for the gettering of P...