Solid State Electronic Devices, 7th Edition

Problems

1. 7.1 Given the data of Prob. 5.2 , plot the doping profiles N_a(x) and N_d(x) for the following double-diffused transistor: The starting wafer is n-type Si with N_d = 10¹⁶ cm⁻³; N_s = 5 × 10¹³ cm⁻² boron atoms are deposited on the surface, and these atoms are diffused into the wafer at 1100°C for 1 hr (D = 3 × 10⁻¹³cm²/s for B in Si at 1100°C); then the wafer is placed in a phosphorus diffusion furnace at 1000°C for 15 min (D = 3 × 10⁻¹⁴ cm²/s for P in Si at 1000°C). During the emitter diffusion, the surface concentration is held constant at 5 × 10²⁰ cm⁻³. You may assume that the base doping profile does not change appreciably during the emitter diffusion, which takes place at a lower temperature and for a shorter time. Find the width ...