I am not sure when the last wet clean was performed. Today I worked with renshen. I ran an endpointed 50 sec etch that looked about right. There was some poly left on the outside edge. He followed with a 300sec seasoning run. The wafer did not have the black ring around the outside edge as he earlier reported, but it was hazy and mircoscope inspection revealed something on the surface. He tried an gasonics strip to determine whether the surface had polymer. The surface did n ot clean up.
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