A silicon water is etched in a Cl2 plasma. A mass flow controller (used to meter the gas flow fed to the reactor) shows a reading of 100 sccm (sccm=standard cm3 per min; standard conditions are 273 K and 1 atm). The etching reactor operates at 100 mTorr pressure, and the reactor gas temperature is 500 K. (note: 1 atm =760 Torr.)
(a) What is the chlorine flow rate at the reactor pressure and temperature?
(b) If the etching rate of silicon is 0.50 ?/min, and the wafer is 300 mm in diameter, how many moles of silicon are etched per hour?