Stranded wafers in ASML Stepper

Gary J Sosa gsosa at
Wed Nov 28 10:54:23 PST 2012

Hello ASML Stepper Users.. 

Below are the Coral details of the most recent incident of wafers getting stuck in the stepper: 

Removed users stranded wafers. Wafer 1 failed at E-chuck because of a vacuum error. Visual inspection of the back of the wafer showed a small black artifact that has some height above the wafer surface. The wafer also did not float on the granite. Once again::: USERS- You are responsible for inspecting the backs of your wafers prior to processing them through the stepper. Especially small lots. This was a 2 wafer lot. It would not have taken that much time to inspect and test the wafers. Because of this, the tool was down for 16 hours and many users inconvenienced. PLEASE INSPECT YOUR WAFERS 

Also, if you think your wafers are high risk( bowed or warped), you can make arrangements with staff to test or process them during normal staff hours when resources are available. 

Thanks... Gary 

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