A multi-point test structure (Figure 1 a,b) was fabricated to measure the resistivity of a 400 nm diameter p-type doped silicon nanowire. Current-voltage measurements (Figure 1c) were carried out by applying a current between contacts 2 and 5 and measuring the voltage (DV) between contacts 3 and 4. Assume that the accepters are fully ionized (p=N a ). Also assume the spacing between all contacts is 1.1 um. (a) Calculate the resistivity of the silicon nanowire assuming the current flows through the entire wire diameter (r=rp in Figure 1d). Using the information provided in Appendix 1.1 of Chapter 1 of the textbook (also included below), estimate the acceptor concentration (N a ) in nanowire. (b) To get a more accurate resistivity value, the calculation should account for the depletion region at the nanowire surface that forms due to band bending associated with interface charge at the metal/silicon contact (Figure 1d). This reduces the effective radius (r e ) of the nanowire that carries current so the calculated resistivity must be corrected to account for the depletion region. To maintain charge neutrality, the charge at the nanowire surface due to interface states (N it ) must be equal to the space