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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link="#0563C1" vlink="#954F72"><div class=WordSection1><p class=MsoNormal>Hi All,<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>We have recently had requests to etch GaAs in our Cl-based RIE systems and As2S3 in our F- and Cl-based RIE systems. We have done minimal work with GaAs in the past, but we have no experience with As2S3. As you can imagine, I am mainly concerned about safety measures in working with these materials. However, I would also like to know about potential contamination of other processes (contamination of Al, AlN, and Cr etch processes in Cl system and SiO2 and SiN etch processes in F system). <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Our Cl-based RIE is load-locked and the exhaust runs through a scrubber that utilizes a combination thermal oxidation chamber and wet scrubbing process. Despite the fact that GaAs and As2S3 form volatile byproducts, I worry about As containing residue in the chamber and the exhaust lines. I would appreciate any comments you have on how to address some of these concerns and how to handle chamber cleans when As residue may be present.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Our F-based RIE systems are not connected to any abatement systems (just lab exhaust), so I have serious reservations about etching any As containing materials in these systems. <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Thanks in advance for any helpful comments you might be able to offer.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Best Regards,<o:p></o:p></p><p class=MsoNormal><br>Matt<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>-- <br><b>Matthew T. Moneck, Ph.D.</b><br>Executive Manager, Carnegie Mellon Nanofabrication Facility<br>Electrical and Computer Engineering | Carnegie Mellon University<br>5000 Forbes Ave., Pittsburgh, PA 15213-3890<br>T: 412.268.5430<br>F: 412.268.3497<br><a href="http://www.ece.cmu.edu"><span style='color:blue'>www.ece.cmu.edu</span></a><br>nanofab.ece.cmu.edu<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>