It is necessary to dope a pure silicon wafer with boron to have a conductivity 1.0 x103 (Ω-m)-1 at a distance 0.1 μm below the surface. The concentration of boron on the silicon surface isheld constant at 1.0 x1025 m-3.
How long does the experiment have to run if the furnace is at 900 °C? The diffusion coefficient for B in Si at 1200 °C is 2.5 x10-12 cm2/s and the activation energy, Qd, is 3.87 eV.