[6] An arsenic (As) dose of 1x1012/cm2 is implanted through a 50-nm layer of silicon dioxide with the peak of the
distribution at the Si-SiO2 interface. A silicon nitride film on top of the silicon dioxide is to be used as a barrier
material in the regions where arsenic (As) is not desired. The background concentration of the substrate is
1x1015/cm3. The projected range (Rp) and straggle (ΔRp) of As implantation at 80 keV are 0.05 µm and 0.017 µm.
(a) What’s the peak concentration at the interface?
(b) How thick should the nitride layer be?
Fig. 1. Room-temperature resistivity in n- and p-type silicon as a function of impurity concentration.