One method of introducing dopant impurities into silicon (so as to control the electronic properties) is to depos a in layer on the surface and allow the impurity to diffuse in at a high temperature. suppose we vapor deposit a thin layer of boron that has 2 x 1015 atoms/cm2 on the surface of a pure silicon wafer, and anneal the wafer for three hours at 1200 c. to about what depth will the boron concentration be greater than 1018 atoms/cm3? to what depth greater than 1016 atoms/cm3? about what will be the concentration of boron at the surface of the silicon? the diffusion coefficient for boron in silicon is given by: q = 3.69 ev: do=14 cm2 /sec.