<div dir="ltr">Hi,<div>You are probably using a Fabmate/graphite crucible. The black film you see is carbon contamination. </div><div>It's mainly coming from the crucible but also from the chamber itself.</div><div>This definitely influences the deposition and the solution we found was:</div><div>1. using a Tungsten crucible. I can share more details about this and our experience so far.</div><div>2. thoroughly cleaning the chamber </div><div><br></div><div>Thank you,</div><div>Youry</div></div><br><div class="gmail_quote gmail_quote_container"><div dir="ltr" class="gmail_attr">On Thu, Sep 17, 2026 at 7:43 AM Chandan H B <<a href="mailto:chandanachar95@gmail.com">chandanachar95@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div class="msg-3029761554683093583">
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Dear LabNetwork Community, We would like to seek inputs from cleanroom/fab facility managers and process owners regarding an issue observed during Au deposition in our E-Beam Evaporators. We have observed the formation of black/dark layer on</div>
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<div dir="ltr"><p>Dear LabNetwork Community,</p><p>We would like to seek inputs from cleanroom/fab facility managers and process owners regarding an issue observed during <strong>Au deposition in our E-Beam Evaporators</strong>.</p><p>We have observed the formation of <strong>black/dark layer on the Au charge after a few melt cycles</strong>. The observation occurs during repeated melting of Au in a tungsten liner/crucible. We are currently investigating whether this could be related to <strong>material surface contamination, crucible/liner condition, outgassing, chamber history, or the Au pre-cleaning/conditioning procedure</strong>.</p><p>We would appreciate your experience on the following:</p><ul><li>Have you observed <strong>black/dark spots or a black layer forming on Au during repeated E-beam melting/evaporation</strong>?</li><li>What <strong>Au purity and material form</strong> do you use?</li><li>Do you perform any <strong>cleaning/degreasing of the Au charge before loading</strong>? If yes, what procedure?</li><li>Do you follow a specific <strong>crucible/liner cleaning or replacement procedure</strong>?</li><li><span style="background-color:transparent">If you have identified a </span><strong style="background-color:transparent">root cause or corrective action</strong><span style="background-color:transparent"> for a similar observation, any details would be highly appreciated.</span></li></ul><p>Our objective is to compare practices across facilities and determine whether this is a <strong>material-handling, source/liner, chamber-condition, or process-related phenomenon</strong>.</p><div>Any suggestions/inputs are highly appreciated.</div><div>Thanks in advance!</div><div><br></div><div>Regards,</div><div>CHANDAN H B</div><div>THIN FILMS ENGINEER</div></div>
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