Method and system for detecting a coolant leak in a dry process chamber wafer chuck
Device and method of configuring a device to process a wafer is disclosed. The device includes a wafer chuck configured to mount the wafer, a dry wafer processing chamber configured to enclose the wafer chuck, a humidity sensor configured to measure relative humidity (RH) at an outlet of the dry wafer processing chamber, a humidity controller coupled to the humidity sensor, the humidity controller being configured to detect a change in RH above a threshold, and a process chamber controller coupled to the humidity controller. The change is triggered by a leakage in deionized water used as a coolant for cooling the wafer chuck and the wafer during the processing. The process chamber controller is configured to trigger a shutdown of the processing of the wafer in response to the leakage.
1. A method comprising:
configuring a dry wafer processing chamber to process a wafer, wherein the dry wafer processing chamber comprises a wafer chuck with a flat mounting surface for mounting the wafer for processing, the wafer chuck is further configured to include a coolant loop within the wafer chuck, and the coolant loop is disposed under the wafer for transferring heat and cooling the wafer chuck by a coolant during a cooling phase of the processing;
measuring relative humidity (RH) of the dry wafer processing chamber;
detecting a change in the RH greater than a threshold value, the change being caused by a leak in the coolant; and
triggering a shutdown of the processing in response to the change.
2. The method of claim 1 , further comprising:
flowing the coolant through the coolant loop during the cooling phase of the processing to cool the wafer chuck,
wherein the coolant comprises deionized water.
3. The method of claim 1 , wherein the RH is measured at an outlet of the dry wafer processing chamber.
4. The method of claim 1 , wherein the shutdown occurs during the cooling phase.
5. The method of claim 3 , wherein the RH is measured by a humidity sensor, and the humidity sensor is bypassed during a wafer transfer phase of the processing.
6. The method of claim 5 , wherein the humidity sensor is disposed within a configurable distance of the outlet, and the configurable distance is selected in dependence of an operating temperature range of the humidity sensor.
7. The method of claim 2 , wherein the deionized water is used to cool the wafer chuck to a configurable idle temperature.
8. The method of claim 1 , wherein the threshold value of the RH is at least 10%.
9. A method comprising:
configuring a dry wafer processing chamber to process a wafer, wherein the dry wafer processing chamber is configured to accommodate a wafer chuck, the wafer chuck is configured to mount the wafer for processing, the wafer chuck is further configured to include a coolant loop within the wafer chuck, and the wafer chuck is further configured to be cooled by deionized water during a cooling phase;
baking the wafer at a configurable baking temperature by using an ultraviolet (UV) energy source;
cooling the wafer chuck during the cooling phase of the processing;
purging compressed dry air (CDA) through the coolant loop to purge the deionized water in response to a completion of the cooling phase;
measuring relative humidity (RH) of the dry wafer processing chamber;
detecting a change in the RH greater than a threshold value, the change being caused by a leak in the deionized water; and
triggering a shutdown of the processing in response to the change.
10. A method comprising:
configuring a dry wafer processing chamber to process a wafer, wherein the dry wafer processing chamber comprises a wafer chuck with a flat mounting surface for mounting the wafer for processing, the wafer chuck is further configured to include a coolant loop within the wafer chuck, the coolant loop is disposed under the wafer for transferring heat and cooling the wafer chuck by a coolant during a cooling phase of the processing, and the coolant comprises deionized water;
measuring relative humidity (RH) of the dry wafer processing chamber;
detecting a change in the RH greater than a threshold value, the change being caused by a leak in the coolant; and
triggering a shutdown of the dry wafer processing in response to the change.
11. The method of claim 10 , wherein the coolant flows through the coolant loop during the cooling phase of the dry wafer processing.
12. The method of claim 10 , wherein the RH is measured at an outlet of the dry wafer processing chamber.
13. The method of claim 12 , wherein the RH is measured by a humidity sensor, and the humidity sensor is bypassed during a wafer transfer phase of the processing.
14. The method of claim 13 , wherein the humidity sensor is disposed within a configurable distance of the outlet, and the configurable distance is selected in dependence of an operating temperature range of the humidity sensor.
15. The method of claim 10 , wherein the dry wafer processing further comprising:
baking the wafer at a configurable baking temperature by using an ultraviolet (UV) energy source;
cooling the wafer chuck during the cooling phase of the dry wafer processing; and
purging compressed dry air (CDA) through the coolant loop to purge the coolant in response to a completion of the cooling phase.
16. The method of claim 15 , wherein the UV energy is deactivated during the cooling phase of the dry wafer processing.
17. The method of claim 10 , wherein the shutdown occurs during the cooling phase.
18. The method of claim 10 , wherein the coolant is used to cool the wafer chuck to a configurable idle temperature.
19. The method of claim 10 , wherein the threshold value of the RH is at least 10%.
20. The method of claim 10 , wherein the dry wafer processing chamber is sealed from the atmosphere.