Patent ID: 7797984

Claim:
A particle monitoring method of a vacuum apparatus having a vessel defining a predetermined space, the vessel including a chamber wall defining a space necessary for performing a manufacturing processing and a wafer stage installed on a bottom surface of the vessel, comprising the steps of: (a) exhausting a purge gas from the vessel via a purge gas exhaust line; (b) monitoring particles within the purge gas exhaust line; (c) controlling a flow rate of the purge gas exhausted from the vessel; (d) supplying the purge gas into the vessel via a gas supply line; (e) controlling a flow rate of the purge gas supplied into the vessel so that a physical vibration due to a shock wave caused by a rapid inflow of the purge gas and transferred to the chamber wall and the wafer stage detaches the particles from the chamber wall and the wafer stage; (f) supplying a corrosive processing gas into the vessel; and (g) exhausting the processing gas from the vessel through a processing gas exhaust line, wherein, a supply of the purge gas is started when exhaust of the purge gas is permitted through the purge gas exhaust line but not permitted through the processing gas exhaust line, and wherein the monitored particles include particles detached from the vessel due to the supply of the purge gas.