Consider a 2-mm-thick silicon wafer to be doped (infused with impurities) using antimony. Assume that the dopant source (gas mixture of antimony chloride and other gases) provides a constant concentration of 1022 atoms/m3. We need a dopant profile such that the concentration of Sb at a depth of 1 micrometer is 5 × 1021 atoms/m3. What will be the time for the diffusion heat treatment? Assume that initially the silicon water contains no impurities or dopants. Assume that the activation energy for diffusion of Sb in silicon is 380 kJ/mol and D0 for Sb diffusion in Si is 1.3 × 10-3 m2/s. Assume T = 1250 °C?