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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Coming not long ago from an LED manufacturer…<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Mercury “Fluorescent” lamps use mercury excitation with familiar excitation spectrum with peaks at G, H and I lines <a href="http://zeiss-campus.magnet.fsu.edu/articles/lightsources/images/mercurylampsfigure1.jpg">http://zeiss-campus.magnet.fsu.edu/articles/lightsources/images/mercurylampsfigure1.jpg</a>. Phosphors are applied to absorb this light and re-emit at target color spectra and can be rated in color temperature.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>LED lamps use a blue LED, typically with emission spectra in the 430 – 460nm range, with phosphors absorption and re-emission. The phosphor blend and application scheme is designed to meet target fluorescence and cost criteria and also are rated in color temperature: 2700K & 3000K (warm), 4500K, 6500K (cool). The excitation blue light is typically not all absorbed by the phosphors or there would be low efficiency, hence there is a emission spectra local peak at the blue excitation wavelength. The epi design to emit at wavelengths shorter than ~430nm suffers from low efficiency and is economically unviable unless those wavelengths are desired in the product.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>So, if your resist is not sensitive below ~430nm, unwanted exposure/desensitization is unlikely.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Dan Pulver<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>MIT Lincoln Lab<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> labnetwork-bounces@mtl.mit.edu [mailto:labnetwork-bounces@mtl.mit.edu] <b>On Behalf Of </b>Ida Noddeland<br><b>Sent:</b> Wednesday, September 23, 2015 2:49 AM<br><b>To:</b> Noah Clay; Tribble, Thomas A.<br><b>Cc:</b> labnetwork@mtl.mit.edu<br><b>Subject:</b> Re: [labnetwork] Fluorescent Lamp Replacement with LED lamps in the Cleanroom?<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>We do not have LED in our cleanroom, but I have heard that it is difficult to see thickness fringes in this kind of light. Another cleanroom (Electrum in Stockholm) installed LED in their EBL area, but had to reinstall some “normal” light sources after requests from the operators.</span><span lang=NO-BOK><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> </span><span lang=NO-BOK><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Best regards,</span><span lang=NO-BOK><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#17365D'>Ida Noddeland</span><span lang=NO-BOK><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#212121'> </span><span lang=NO-BOK><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:8.0pt;font-family:"Calibri","sans-serif";color:#95B3D7'>Head of Laboratory</span><span lang=NO-BOK><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:8.0pt;font-family:"Calibri","sans-serif";color:#95B3D7'>NTNU NanoLab</span><span lang=NO-BOK><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:8.0pt;font-family:"Calibri","sans-serif";color:#95B3D7'> </span><span lang=NO-BOK><o:p></o:p></span></p><p class=MsoNormal><span lang=NO-BOK style='font-size:8.0pt;font-family:"Calibri","sans-serif";color:#95B3D7'>Sem Sælands vei 14, K1-123</span><span lang=NO-BOK><o:p></o:p></span></p><p class=MsoNormal><span lang=NO-BOK style='font-size:8.0pt;font-family:"Calibri","sans-serif";color:#95B3D7'>7491 Trondheim</span><span lang=NO-BOK><o:p></o:p></span></p><p class=MsoNormal><span lang=NO-BOK style='font-size:8.0pt;font-family:"Calibri","sans-serif";color:#95B3D7'>+47 41288808</span><span lang=NO-BOK><o:p></o:p></span></p><p class=MsoNormal><span lang=NO-BOK style='font-size:8.0pt;font-family:"Calibri","sans-serif";color:#95B3D7'><a href="http://www.ntnu.no/nanolab"><span style='color:#95B3D7'>www.ntnu.no/nanolab</span></a></span><span lang=NO-BOK><o:p></o:p></span></p><p class=MsoNormal><span lang=NO-BOK style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> </span><span lang=NO-BOK><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> </span><span lang=NO-BOK><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> </span><span lang=NO-BOK><o:p></o:p></span></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> <a href="mailto:labnetwork-bounces@mtl.mit.edu">labnetwork-bounces@mtl.mit.edu</a> [<a href="mailto:labnetwork-bounces@mtl.mit.edu">mailto:labnetwork-bounces@mtl.mit.edu</a>] <b>On Behalf Of </b>Noah Clay<br><b>Sent:</b> Tuesday, September 22, 2015 11:52 PM<br><b>To:</b> Tribble, Thomas A.<br><b>Cc:</b> <a href="mailto:labnetwork@mtl.mit.edu">labnetwork@mtl.mit.edu</a><br><b>Subject:</b> Re: [labnetwork] Fluorescent Lamp Replacement with LED lamps in the Cleanroom?</span><span lang=NO-BOK><o:p></o:p></span></p></div></div><p class=MsoNormal><span lang=NO-BOK> <o:p></o:p></span></p><p class=MsoNormal><span lang=NO-BOK>Tom,<o:p></o:p></span></p><div><p class=MsoNormal><span lang=NO-BOK> <o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=NO-BOK>We use LED strip lights (3M, I believe) in our wet benches from Reynolds Tech. As far as I know, they install LED lighting circuits in all of their new bench builds and I recommend speaking with Vince Reynolds for further information. The lighting in our lithography benches have yellow filters on them and have posed no issues with our research community. For the time being, the overhead cleanroom lighting at Penn is fluorescent.<o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=NO-BOK> <o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=NO-BOK>Thanks,<o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=NO-BOK>Noah<o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=NO-BOK> <o:p></o:p></span></p></div><div><p class=MsoNormal><i><span lang=NO-BOK>Quattrone Nanofabrication Facility</span></i><span lang=NO-BOK><o:p></o:p></span></p></div><div><p class=MsoNormal><i><span lang=NO-BOK>University of Pennsylvania</span></i><span lang=NO-BOK><o:p></o:p></span></p></div><div><p class=MsoNormal><i><span lang=NO-BOK>Philadelphia, PA</span></i><span lang=NO-BOK><o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=NO-BOK> <o:p></o:p></span></p><div><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><div><p class=MsoNormal><span lang=NO-BOK>On Sep 22, 2015, at 2:30 PM, Tribble, Thomas A. <<a href="mailto:tribble@fas.harvard.edu">tribble@fas.harvard.edu</a>> wrote:<o:p></o:p></span></p></div><p class=MsoNormal><span lang=NO-BOK> <o:p></o:p></span></p><div><div><p class=MsoNormal><span lang=NO-BOK style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>The replacement of T-8 and T-5 fluorescent lamps outside the cleanroom is becoming an increasingly popular Facilities practice. Has there been any experience with this kind of retrofit inside the cleanroom? Specifically, in Lithography and other UV sensitive areas of the cleanroom, have there been any observed (or anticipated) adverse effects from the use of LED lamps?</span><span lang=NO-BOK><o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=NO-BOK style='font-size:11.0pt;font-family:"Calibri","sans-serif"'> </span><span lang=NO-BOK><o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=NO-BOK style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>Thanks . . . Tom</span><span lang=NO-BOK><o:p></o:p></span></p></div><p class=MsoNormal align=center style='text-align:center'><span lang=NO-BOK style='font-size:11.0pt;font-family:"Calibri","sans-serif"'> </span><span lang=NO-BOK><o:p></o:p></span></p><p class=MsoNormal align=center style='text-align:center'><b><span lang=NO-BOK style='font-size:10.0pt;font-family:"Leelawadee","sans-serif";color:#365F91'>Thomas A Tribble PE, JD | Northwest 102.32 | 52 Oxford Street | Cambridge, MA 02138 | (tel) 617 495 0990 |(cell) 617 780 5685 |</span></b><span lang=NO-BOK><o:p></o:p></span></p><div><p class=MsoNormal><span lang=NO-BOK style='font-size:11.0pt;font-family:"Calibri","sans-serif"'> </span><span lang=NO-BOK><o:p></o:p></span></p></div><p class=MsoNormal><span lang=NO-BOK style='font-size:9.0pt;font-family:"Helvetica","sans-serif"'>_______________________________________________<br>labnetwork mailing list<br></span><span lang=NO-BOK><a href="mailto:labnetwork@mtl.mit.edu"><span style='font-size:9.0pt;font-family:"Helvetica","sans-serif";color:purple'>labnetwork@mtl.mit.edu</span></a></span><span lang=NO-BOK style='font-size:9.0pt;font-family:"Helvetica","sans-serif"'><br></span><span lang=NO-BOK><a href="https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork"><span style='font-size:9.0pt;font-family:"Helvetica","sans-serif";color:purple'>https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork</span></a><o:p></o:p></span></p></div></blockquote></div><p class=MsoNormal><span lang=NO-BOK> <o:p></o:p></span></p></div></div></body></html>