) A silicon wafer (Si: n = 100cm 3 and ε = 11) is used to make a PN junction over a circular area with a diameter r=1 mm. Aluminum is used as a p-type dopant with density of 101cm), and Arsenic as an n-type dopant with density of 10’5cm3. (a) (4) Find the Fermi energies and E, in the n-type and p-type regions far from the junction with respect to the intrinsic Fermi energy Efi, and find the built-in voltage V.. (b) (3) Draw the band diagram when a reverse voltage Ve =-1 V is applied. (c) (4) Find the depletion width W , the maximum electric field E, and junction capacitance at this bias. (d) (3) What are the two main mechanisms of breakdown in PN junction? Explain the differences. Which one happens in highly doped junctions?