(a) If SF6 flow in a single wafer RIE etch reactor is 50cm3/min, under standard temperature and pressure, what is the theoretical maximum etch rate of 100mm diameter silicon wafer? You can calculate this via number of atoms (1mole=61023 atoms) and silicon density (2300kg/m3). (b) List at least two reason why we can never reach the maximum etch rate in the real world