Method for monitoring gas in wafer processing system

A wafer processing system, comprising:

• an exhausting conduit configured to guide an exhaust flow, wherein the exhausting conduit has a through hole, and a passage axis passes through the through hole;
• a shelter member positioned in the exhausting conduit and comprising an outer channel extends along the passage axis, wherein the outer channel has an outer opening arranged on the passage axis;
• a sampling tube positioned in the outer channel and comprising an inner channel, wherein the sampling tube has an inner opening arranged on the passage axis, and the outer opening is located farther away from the through hole than the inner opening;
• and
• a gas sensor connected to the sampling tube and configured to monitor gas condition in the exhausting conduit.

A method for monitoring gas in a wafer processing system, comprising;

• producing an exhaust flow in an exhausting conduit from a processing chamber;
• placing a gas sensor in fluid communication with a detection point located in the exhausting conduit via a sampling tube that passes through a through hole formed on the exhausting conduit, wherein the detection point is located away from the through hole;
• detecting a gas condition at the detection point with the gas sensor;
• and
• analyzing the gas condition detected by the gas sensor to determine if the gas condition in the exhausting conduit is in a range of values.