Today we had this problem, so SF issue (suspect substrate issue) follow up passdown are as below:
Need to do surf scan for wafers placed on F3X1 rack at 01:15 AM and share results with XL to compile report.
All result with increasing trend especially for slot 01# but the defects count still within SPEC.Pls continue monitor one more time end of night shift. Tomorrow we will review the result and decide whether still need to monitor or not
As per discussed with Wong we will stop the SS check as defects trend keep increasing after facility resolved ceiling issue. Team will decide whether can release the rack to production or not as dust count still fail verified by EPI PE
Latest SS done @ 18/Jul 01:15 AM For sure the defects average with increasing trend.Final defects count average is 18 from 30/Jun 01:15 pm until 18/Jul 01:15 am totally 420 HRS.
To discuss with team whether acceptable or still need to collect the data further.
