Endpoint detection of deposition cleaning in a pumping line and a processing chamber
A method is provided for cleaning of a processing system comprising a wafer processing chamber and a pumping line in fluid connection with the wafer processing chamber. The method includes initiating cleaning of the wafer processing chamber by activating a chamber cleaning source and initiating cleaning of at least a portion of the pumping line by activating a foreline cleaning source coupled to the pumping line. The method also includes monitoring, at a downstream endpoint detector coupled to the pumping line, a level of a signature substance. The method further includes determining, by the downstream endpoint detector, at least one of a first endpoint of the cleaning of the wafer processing chamber or a second endpoint of the cleaning of the pumping line based on the monitoring.
1. A method for cleaning of a processing system comprising a wafer processing chamber and a pumping line in fluid connection with the wafer processing chamber and located downstream from the wafer processing chamber, the method comprising:
initiating cleaning of the wafer processing chamber by activating a chamber cleaning source;
initiating cleaning of at least a portion of the pumping line by activating a foreline cleaning source coupled to the pumping line, the foreline cleaning source located downstream from the wafer processing chamber, wherein at least a portion of a duration of the cleaning of the pumping line overlaps in time with at least a portion of a duration of the cleaning of the wafer processing chamber;
monitoring, at a downstream endpoint detector coupled to the pumping line, a level of a signature substance that is a byproduct from the cleaning of at least one of the chamber or the pumping line, wherein a location of the downstream endpoint detector is downstream from both the wafer processing chamber and the foreline cleaning source;
monitoring, at an intermediate endpoint detector coupled to the pumping line, a second level of the signature substance; and
determining at least one of a first endpoint of the cleaning of the wafer processing chamber or a second endpoint of the cleaning of the pumping line based on at least one of the level of the byproduct signature substance monitored by the downstream endpoint detector or the second level of the signature substance monitored by the intermediate endpoint detector.
2. The method of claim 1 , wherein a location of the intermediate endpoint detector is downstream from the wafer processing chamber while upstream from the foreline cleaning source and the downstream endpoint detector.
3. The method of claim 2 , wherein the intermediate endpoint detector is adapted to detect the first endpoint of the wafer processing chamber cleaning based on the second level of the signature substance monitored.
4. The method of claim 3 , wherein a difference between the level of the signature substance monitored by the downstream endpoint detector and the second level of the signature substance monitored by the intermediate endpoint detector is used to detect the second endpoint of the pumping line cleaning.
5. The method of claim 1 , wherein the location of the intermediate endpoint detector is downstream from the wafer processing chamber and the foreline cleaning source, while upstream from the downstream endpoint detector.
6. The method of claim 5 , further comprising deactivating the foreline cleaning source prior to monitoring by the intermediate endpoint detector to detect the first endpoint of the wafer processing chamber cleaning.
7. The method of claim 6 , wherein the level of the signature substance monitored by the downstream endpoint detector is used to detect the second endpoint of the pumping line cleaning.
8. A method for cleaning of a processing system comprising a wafer processing chamber and a pumping line in fluid connection with the wafer processing chamber and located downstream from the wafer processing chamber, the method comprising:
initiating cleaning of the wafer processing chamber by activating a chamber cleaning source;
initiating cleaning of at least a portion of the pumping line by activating a foreline cleaning source coupled to the pumping line, the foreline cleaning source located downstream from the wafer processing chamber, wherein at least a portion of a duration of the cleaning of the pumping line overlaps in time with at least a portion of a duration of the cleaning of the wafer processing chamber;
monitoring, at an intermediate endpoint detector coupled to the pumping line, a first level of a signature substance to determine a first endpoint of the cleaning of the wafer processing chamber, wherein a location of the intermediate endpoint is downstream from the wafer processing chamber; and
monitoring, at a downstream endpoint detector coupled to the pumping line, a second level of the signature substance to determine a second endpoint of the cleaning of the pumping line, wherein a location of the downstream endpoint detector is downstream from the wafer processing chamber, the foreline cleaning source and the intermediate endpoint detector.