This morning all three doors on HAM6 were removed.The particle counts during the removal were, with one exception, very good. There was one spike of 0.3µ particles to 8480 counts when opening the east door. The door was open but still on 4 bolts. It looked as if we stirred up a cluster of dust when the door popped open. The air flow was positive, so there should have been little contamination into the chamber.
| Time | 0.3µ | 0.5µ | |
|---|---|---|---|
| Door On | 08:52 | 0 | 0 |
| Door Open | 08:55 | 90 | 70 |
| Cover On | 09:08 | 0 | 0 |
| Inside Chamber - Cover on | 09:18 | 0 | 0 |
| Time | 0.3µ | 0.5µ | |
|---|---|---|---|
| Door On | 09:27 | 60 | 40 |
| Door Open | 09:31 | 8480 | 40 |
| Cover On | 10:10 | 60 | 60 |
| Inside Chamber - Cover on | 10:12 | 20 | 0 |
The North door was removed while I was working on setting up the east side cleanroom so no readings were taken. Checks later and a 48 hours trend (posted below) did not show any serious contamination control issues. The 48 hour trend showed only one spike of 0.5µ particles over 100 counts, recorded while the crew were doing the door removal. The two large spikes on 04/05 were caused by the in first cleaning of the main HAM6 cleanroom. These spikes were expected. In general, the contamination control around HAM6, in the rest of the LVEA and in the VEAs has been excellent. This is mostly due to the efforts of Christina and Karen.
The 4" wafer was removed and will; be sent to CIT for analysis.
