Question

The concentration of impurities in a semiconductor used in the production of microprocessors for computer is a normally distributed random variable with mean 127 ppm and standard deviation 22 ppm a semiconductor is acceptable only if concentration of impurities in below 150 ppm what is the proportion of the semiconductor that are acceptable for use

Answer 1

The process of adding controlled impurities to a semiconductor is known as doping. The amount of impurity, or dopant, added to an intrinsic (pure) semiconductor varies its level of conductivity. Doped semiconductors are often referred to as extrinsic.