The present invention provides a semiconductor device manufacturing line for applying a series of processes on a semiconductor substrate, and forming an integrated circuit on the semiconductor substrate by employing a semiconductor wafer having a diameter of 6 inches or less for the semiconductor substrate. The output terminal of the non-linear amplifier is further coupled to the output terminal of the linear amplifier via a series impedance. Two of the exhaust flow passages join in the cylinder head to direct exhaust flow into only one of the inlets of the housing and through the first scroll passage.