ELE533 Bipolar Devices

Mid Term Exam
October 25, 2005

Figure 3

3. Consider the nn+ junction shown in Figure 3. (This represents the epi-buried layer junction.) The n type epi is doped with N_D = 5 X 10¹⁵ donors/cm³. The doping level in the n+ buried layer is 10¹⁷ donors/cm³.
   What is the equilibrium voltage of the EPI relative to the burried layer?