Method and apparatus for detecting foreign material on a chuck
View Patent ↗An apparatus and method for leak detection of coolant gas from a chuck. The apparatus includes a chuck having a top surface and configured to clamp a substrate to the top surface, the chuck having one or more recessed regions in the top surface, the recessed regions configured to allow a cooling gas to contact a backside of the substrate; a cooling gas inlet and a cooling gas outlet connected to the one or more recessed regions; a first measurement device connected to the cooling gas inlet and configured to measure a first amount of cooling gas entering the cooling gas inlet and a second measurement device connected to the cooling gas outlet and configured to measure a second amount of cooling gas exiting from the cooling gas outlet; and a controller configured to determine a difference between the first amount of cooling gas and the second amount of cooling gas.
1. An apparatus comprising:
a chuck having a top surface and configured to clamp a substrate to said top surface, said chuck having one or more recessed regions in said top surface, said recessed regions configured to allow a cooling gas to contact a backside of said substrate;
a cooling gas inlet and a cooling gas outlet connected to said one or more recessed regions;
a first measurement device connected to said cooling gas inlet and configured to measure a first amount of cooling gas entering said cooling gas inlet;
a second measurement device connected to said cooling gas outlet and configured to measure a second amount of cooling gas exiting from said cooling gas outlet; and
a controller configured to determine a difference between said first amount of cooling gas and said second amount of cooling gas,
wherein said cooling gas comprises helium, neon, argon, or nitrogen.
2. The apparatus of claim 1 , wherein said first amount of cooling gas is a first mass of cooling gas and said second amount of cooling gas is a second mass of cooling gas.
3. The apparatus of claim 1 , wherein said first measurement device is a first mass flow meter and said second measurement device is a second mass flow meter.
4. The apparatus of claim 1 , wherein said chuck is an electrostatic chuck.
5. The apparatus of claim 1 , wherein said chuck is configured to clamp a circular semiconductor wafer.
6. The apparatus of claim 1 , wherein said controller is configured to generate an alarm when said difference is greater than a specified value.
7. The apparatus of claim 1 , further including: a vacuum process chamber, said chuck disposed within said vacuum process chamber, wherein said chuck and vacuum process chamber comprise a high pressure plasma deposition tool or a reactive ion etch tool.
8. The apparatus of claim 7 , wherein said controller is configured (i) to prevent deposition of material onto said substrate when said difference is greater than a specified value or (ii) to prevent etching of said substrate when said difference is greater than a specified value.
9. The apparatus of claim 1 , further including a substrate handling system configured to load said substrate onto said chuck and remove said substrate from said chuck.
10. A method comprising:
providing a chuck having a top surface and configured to clamp a substrate to said top surface, said chuck having one or more recessed regions in said top surface, said recessed regions configured to allow a cooling gas to contact a backside of said substrate, said chuck including a cooling gas inlet and a cooling gas outlet connected to said one or more recessed regions;
supplying cooling gas to said cooling gas inlet and exhausting said cooling gas from said cooling gas outlet;
measuring a first amount of cooling gas entering said cooling gas inlet;
measuring a second amount of cooling gas exiting from said cooling gas outlet; and
determining a difference between said first amount of cooling gas and said second amount of cooling gas,
wherein said cooling gas comprises helium, neon, argon, or nitrogen.
11. The method of claim 10 , wherein said first amount of cooling gas is a first mass of cooling gas and said second amount of cooling gas is a second mass of cooling gas.
12. The method of claim 10 , wherein said measuring said first amount of cooling gas is performed using a first mass flow meter and said measuring said second amount of cooling gas is performed using a second mass flow meter.
13. The method of claim 10 , wherein said chuck is an electrostatic chuck.
14. The method of claim 10 , wherein said chuck is configured to clamp a circular semiconductor wafer.
15. The method of claim 10 , wherein said controller generates an alarm when said difference is greater than a specified value.
16. The method of claim 10 , further including: disposing said chuck in a vacuum process chamber, wherein said chuck and vacuum process chamber comprise a high pressure plasma deposition tool or a reactive ion etch tool.
17. The method of claim 16 , wherein said controller generates a signal (i) to prevent deposition of material onto said substrate when said difference is greater than a specified value or (ii) to prevent etching of said substrate when said difference is greater than a specified value.
18. The method of claim 10 , further including providing a substrate handling system to load said substrate onto said chuck and remove said substrate from said chuck.