4.2 Three questions regarding high-resistivity Si in thermal equilibrium at room temperature:
a. Calculate the conductivity of intrinsic Si.
b. Calculate the sheet resistance of a 600-ĆĀ¼m thick intrinsic Si wafer.
c. Does intrinsic Si exhibit the lowest conductivity that Si can attain at room temperature? If not, describe the situation that leads to the lowest possible conductivity, derive an expression for it, and calculate its value.