<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=us-ascii"><meta name=Generator content="Microsoft Word 14 (filtered medium)"><!--[if !mso]><style>v\:* {behavior:url(#default#VML);}
o\:* {behavior:url(#default#VML);}
w\:* {behavior:url(#default#VML);}
.shape {behavior:url(#default#VML);}
</style><![endif]--><style><!--
/* Font Definitions */
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:Tahoma;
panose-1:2 11 6 4 3 5 4 4 2 4;}
@font-face
{font-family:"Trebuchet MS";
panose-1:2 11 6 3 2 2 2 2 2 4;}
@font-face
{font-family:"Minion Pro";}
@font-face
{font-family:"Microsoft Sans Serif";
panose-1:2 11 6 4 2 2 2 2 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri","sans-serif";}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
p.MsoAcetate, li.MsoAcetate, div.MsoAcetate
{mso-style-priority:99;
mso-style-link:"Balloon Text Char";
margin:0in;
margin-bottom:.0001pt;
font-size:8.0pt;
font-family:"Tahoma","sans-serif";}
span.EmailStyle17
{mso-style-type:personal;
font-family:"Calibri","sans-serif";
color:windowtext;}
span.EmailStyle18
{mso-style-type:personal-reply;
font-family:"Trebuchet MS","sans-serif";
color:#1F497D;
font-weight:normal;
font-style:normal;
text-decoration:none none;}
span.BalloonTextChar
{mso-style-name:"Balloon Text Char";
mso-style-priority:99;
mso-style-link:"Balloon Text";
font-family:"Tahoma","sans-serif";}
.MsoChpDefault
{mso-style-type:export-only;
font-size:10.0pt;}
@page WordSection1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.WordSection1
{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Trebuchet MS","sans-serif";color:#1F497D'>Hello Rick,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Trebuchet MS","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Trebuchet MS","sans-serif";color:#1F497D'>Your 45% is the right target. +-3% is the absolute widest you should go. <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Trebuchet MS","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Trebuchet MS","sans-serif";color:#1F497D'>If you can keep within 2%, your tools/processes will be the limiting factor of your sub-micron repeatability. Any wider range than that and your RH variation could start taking away from your repeatability.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Trebuchet MS","sans-serif";color:#1F497D'>For example: Deep sub-micrometer geometries on an automatic developer will be sensitive to even +-2%. With large geometries and developing in a beaker +-3% is fine. <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Trebuchet MS","sans-serif";color:#1F497D'>Here at CNST we shoot for +-2% and achieve better than +-1%. A class 10 clean room will have enough air changes/minute to do very well if the HVAC designer specs the right humidity control hardware.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Trebuchet MS","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Trebuchet MS","sans-serif";color:#1F497D'>Good Luck!<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Trebuchet MS","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Trebuchet MS","sans-serif";color:#1F497D'>Vince<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Trebuchet MS","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-family:"Microsoft Sans Serif","sans-serif";color:#1F497D'>Vincent K. Luciani<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Microsoft Sans Serif","sans-serif";color:#1F497D'>NanoFab Manager<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Microsoft Sans Serif","sans-serif";color:#1F497D'><a href="http://www.cnst.nist.gov/">Center for Nanoscale Science and Technology</a><o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Microsoft Sans Serif","sans-serif";color:#1F497D'>National Institute of Standards and Technology<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Microsoft Sans Serif","sans-serif";color:#1F497D'>100 Bureau Drive, MS 6201<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Microsoft Sans Serif","sans-serif";color:#1F497D'>Gaithersburg, MD 20899-6200 USA<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Microsoft Sans Serif","sans-serif";color:#1F497D'>+1-301-975-2886<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Minion Pro";color:#1F497D'><img border=0 width=194 height=37 id="Picture_x0020_1" src="cid:image001.jpg@01CC520A.D19475E0" alt="Description: CNST Horztl Color logo"></span><span style='color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Trebuchet MS","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Trebuchet MS","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Trebuchet MS","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>Morrison, Richard H., Jr.<br><b>Sent:</b> Tuesday, August 02, 2011 11:49 AM<br><b>To:</b> labnetwork@mtl.mit.edu<br><b>Subject:</b> [labnetwork] RH question<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Hi Everyone,<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Draper Laboratory is in the design phase for a new 6,000 sqft cleanroom. We are lucky enough to have a chance to have a Class 10 photolithography area. My question is what are others using for a humidity spec for the photolithography area, we are thinking 45% +-3%. This is based on research done by Dave Carter here at Draper.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Any thoughts?<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Rick<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Rick Morrison<o:p></o:p></p><p class=MsoNormal>Senior Member Technical Staff <o:p></o:p></p><p class=MsoNormal>Acting Group Leader Mems Fabrication<o:p></o:p></p><p class=MsoNormal>Draper Laboratory<o:p></o:p></p><p class=MsoNormal>555 Technology Square<o:p></o:p></p><p class=MsoNormal>Cambridge, MA 02139<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>617-258-3420<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>