Problem drytek4 SNF 2011-11-07 11:42:18: wafers don't fit into chuck

[ehe at snf.stanford.edu]

My 4" wafers  have not fit into the chuck (they don't lie flat in the wafer cutout) for a couple months.. they have a couple microns of epitaxy on either edge and have edge bead removal around he edges using the coater track. not sure if it's related but i have not been able to repeat results from april and SEMS of structures show the sidewall profile has gone from a neat 5-deg to a real mess (think melting upside-down peanut butter cup) so something has really changed since april. I tried in july and october and can't get good results again so i have to move to another etch tool for that process.