a. There are three major steps which are used to explain the flow of carriers through a PN junction diode. Name these steps. b. Why is the current an exponential function of the applied forward bias voltage (as opposed to a linear, quadratic or other types of dependences)? c. We know that there are two types of current flows in the semiconductors, i.e., drift and diffusion current. Which of these carrier flow mechanisms are involved in the forward bias current flow? d. Consider a PN junction with P-type and N-type regions, which are equally doped. What type of carriers (p-type or n-type) are responsible for the flow of current in this system? e. Answer part (d) again, considering when (1) the P-type region has doping much larger than the N-type region and (2) when the N-type region has doping much larger than the P-type region. (Hint: Heavily doped region has small minority carrier concentration, and the first step of current flow is minority carrier injection.)