<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body dir="auto">
<div><span></span></div>
<div>
<div><span></span></div>
<div>
<p class="MsoNormal" style="margin: 0cm 0cm 0.0001pt;"><span style="background-color: rgba(255, 255, 255, 0);">Dear Labnetwork Members,</span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0.0001pt;"><span lang="EN-GB" style="background-color: rgba(255, 255, 255, 0);"> </span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0.0001pt;"><span lang="EN-GB" style="background-color: rgba(255, 255, 255, 0);">I’ve just recently started as process group leader here at NTNU NanoLab in Trondheim, Norway, but have been following the discussions
on the mailing list with interest.<o:p></o:p></span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0.0001pt;"><span lang="EN-GB" style="background-color: rgba(255, 255, 255, 0);"> </span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0.0001pt;"><span lang="EN-GB" style="background-color: rgba(255, 255, 255, 0);">I now have a question of my own and would very much appreciate any thoughts or advice you may be able to share.<o:p></o:p></span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0.0001pt;"><span lang="EN-GB" style="background-color: rgba(255, 255, 255, 0);"> </span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0.0001pt;"><span lang="EN-GB" style="background-color: rgba(255, 255, 255, 0);">We are currently having preventive maintenance of our ICP-RIE systems carried out by the manufacturer.<o:p></o:p></span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0.0001pt;"><span lang="EN-GB" style="background-color: rgba(255, 255, 255, 0);">Unfortunately one of their engineers mixed up the helium backing line with the coolant line from the chiller unit. When the chiller was
switched on, it pumped ca. 1-2 litres of a water and Hexid heat transfer fluid into the main chamber and loadlock. The system was not under vacuum at the time. The RIE section was completely filled with water and the main chamber also had water in it. The
lifting pins assembly including bellows, the CM gauge the pirani gauge as well as the He line were completely submerged.<o:p></o:p></span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0.0001pt;"><span lang="EN-GB" style="background-color: rgba(255, 255, 255, 0);">The engineers realised what was going on after the chiller gave a low level alarm and they saw the coolant level continue to drop. They
stopped the chiller, opened the chamber, and mopped up the liquid with PIG pads and cleanroom cloths where accessible. They then switched on both the roughing and loadlock pump.<o:p></o:p></span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0.0001pt;"><span lang="EN-GB" style="background-color: rgba(255, 255, 255, 0);">When the loadlock pump was switched on it died immediately. They realised that water vapour shouldn’t enter the scrubber and removed
the exhaust line from the scrubber, but it is likely that some water vapour ++ entered the scrubber as steam was coming out of the exhaust. This means the entire system has been exposed to water/coolant mix, possibly with exception of the turbo pump, although
there may have been some backstreaming from the main roughing pump.<o:p></o:p></span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0.0001pt;"><span lang="EN-GB" style="background-color: rgba(255, 255, 255, 0);"> </span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0.0001pt;"><span lang="EN-GB" style="background-color: rgba(255, 255, 255, 0);">Pumping the chamber <a dir="ltr" href="x-apple-data-detectors://1" x-apple-data-detectors="true" x-apple-data-detectors-type="calendar-event" x-apple-data-detectors-result="1">from
Thursday</a> to the following Tuesday improved the vacuum from 1x10e-2 Torr with a leakup rate of 20 mTorr/min to 5x10e-5 Torr with a leakup rate of 5 mTorr/min. Specification is less than 1 mTorr/min.<o:p></o:p></span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0.0001pt;"><span lang="EN-GB" style="background-color: rgba(255, 255, 255, 0);"> </span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0.0001pt;"><span lang="EN-GB" style="background-color: rgba(255, 255, 255, 0);">Needless to say this causes a number of issues, some of which we may not even have thought to consider.<o:p></o:p></span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0.0001pt;"><span lang="EN-GB" style="background-color: rgba(255, 255, 255, 0);"> </span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0.0001pt;"><span lang="EN-GB" style="background-color: rgba(255, 255, 255, 0);">In our view, the issues can be divided into immediate Health and Safety concerns, and more long term concerns regarding the performance
of an ICP RIE unit that has been flooded<o:p></o:p></span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0.0001pt;"><span lang="EN-GB" style="background-color: rgba(255, 255, 255, 0);"> </span></p>
<p class="MsoListParagraph" style="text-indent: 0px; margin: 0cm 0cm 0.0001pt 36pt;">
<span style="background-color: rgba(255, 255, 255, 0);"><span lang="EN-GB">1.</span><span lang="EN-GB"> </span><span lang="EN-GB">Regarding H&S issues we’re concerned about are the mixing of SF6, CHF3,</span><span lang="EN-GB"> Cl2 and BCl3 with water
in the scrubber.<o:p></o:p></span></span></p>
<p class="MsoListParagraph" style="margin: 0cm 0cm 0.0001pt 36pt;"><span style="background-color: rgba(255, 255, 255, 0);"><span lang="EN-GB">We will send the scrubber for a refill and check. </span><span lang="EN-GB">We have contacted the vendor of the scrubber,
his main concern is clogging of the granulate. Is there anything else we should pay attention to?</span><span lang="EN-GB"><o:p></o:p></span></span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0.0001pt;"><span lang="EN-GB" style="background-color: rgba(255, 255, 255, 0);"> </span></p>
<p class="MsoListParagraph" style="text-indent: 0px; margin: 0cm 0cm 0.0001pt 36pt;">
<span style="background-color: rgba(255, 255, 255, 0);"><span lang="EN-GB">2.</span><span lang="EN-GB"> </span><span lang="EN-GB">Can a chamber be sufficiently reconditioned by in situ by cleaning, baking and running plasmas or will the coolant inside
necessitate a more complete disassembly and clean?<o:p></o:p></span></span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0.0001pt 35.4pt;"><span lang="EN-GB" style="background-color: rgba(255, 255, 255, 0);">Has anyone had a similar problem and how did you proceed? How would you suggest we ask the manufacturer to verify that there are
no long-term detrimental effects on the instrument, the pumps or the processes run on the instrument?<o:p></o:p></span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0.0001pt;"><span lang="EN-GB" style="background-color: rgba(255, 255, 255, 0);"> </span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0.0001pt;"><span lang="EN-GB" style="background-color: rgba(255, 255, 255, 0);"> </span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0.0001pt;">I'd appreciate any thoughts you may have surrounding this issue. </p>
<p class="MsoNormal" style="margin: 0cm 0cm 0.0001pt;"><span lang="EN-GB" style="background-color: rgba(255, 255, 255, 0);"><br>
</span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0.0001pt;"><span lang="DE" style="background-color: rgba(255, 255, 255, 0);">Kind regards,<o:p></o:p></span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0.0001pt;"><span lang="DE" style="background-color: rgba(255, 255, 255, 0);"> </span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0.0001pt;"><span lang="DE" style="background-color: rgba(255, 255, 255, 0);">Peter</span></p>
<div>
<div>
<div style="orphans: 2; widows: 2;">
<div style="orphans: auto; widows: auto;"><span style="background-color: rgba(255, 255, 255, 0);"><br>
</span></div>
</div>
<div style="orphans: auto; widows: auto;"><span style="background-color: rgba(255, 255, 255, 0);"><br>
</span></div>
<div style="orphans: auto; widows: auto;"><span style="background-color: rgba(255, 255, 255, 0);"><br>
</span></div>
<div style="orphans: auto; widows: auto;"><span style="background-color: rgba(255, 255, 255, 0);">––––––––––––––––––––––––––––––––––––––––––––––</span></div>
<div style="orphans: auto; widows: auto;"><span style="background-color: rgba(255, 255, 255, 0);"><br>
</span></div>
<div style="orphans: auto; widows: auto;"><span style="background-color: rgba(255, 255, 255, 0);">Dr. Peter A. Köllensperger</span></div>
</div>
<div>NTNU NanoLab</div>
<div style="orphans: auto; widows: auto;">Sem Sælandsvei 14</div>
<div style="orphans: auto; widows: auto;"><span style="background-color: rgba(255, 255, 255, 0);">Norwegian University of Science and Technology (NTNU)</span></div>
<div style="orphans: auto; widows: auto;"><span style="background-color: rgba(255, 255, 255, 0);">7491 Trondheim</span></div>
<div><span style="background-color: rgba(255, 255, 255, 0);"><br>
</span><br>
</div>
</div>
</div>
<div><br>
<br>
<div><br>
</div>
<div>
<div>
<div>
<div style="orphans: 2; widows: 2;">
<div style="orphans: auto; widows: auto;"><span style="background-color: rgba(255, 255, 255, 0);"><br>
</span></div>
<div style="orphans: auto; widows: auto;"><span style="background-color: rgba(255, 255, 255, 0);"><br>
</span></div>
</div>
<div style="orphans: auto; widows: auto;"><span style="background-color: rgba(255, 255, 255, 0);"><br>
</span></div>
<div style="orphans: auto; widows: auto;"><br>
</div>
</div>
</div>
</div>
</div>
</div>
</body>
</html>