Comment epi2 SNF 2012-11-11 20:10:05: LLA cassette dirty

The black particle on the wafer after epi seems to originate from the black cassette. Looking into the edges of the cassette the burnt mark is clearly visible. I think some users got the wafer into LLA before cooling it. Would it be possible to replace the cassette? I've blown the dust away the particle with N2 gun for now but worried that this would get worse.