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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal>Colleagues<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I have a cross contamination question on our Cambridge ALD tool. A user requests to do Al2O3 on Bi2Se3 and Nb structures on sapphire (and prefers to use only acetone and IPA pre-clean). Does anyone know:<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='mso-list:Ignore'>1.<span style='font:7.0pt "Times New Roman"'> </span></span><![endif]>If there is cross-contamination issue for MOS users?<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='mso-list:Ignore'>2.<span style='font:7.0pt "Times New Roman"'> </span></span><![endif]>Any procedure to minimize the contamination (Additional pre-clean or post-clean? Certain deposition to “bury” the contamination etc.)?<o:p></o:p></p><p class=MsoNormal>Several things to note are:<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l1 level1 lfo2'><![if !supportLists]><span style='mso-list:Ignore'>a.<span style='font:7.0pt "Times New Roman"'> </span></span><![endif]>The exposed areas are <span style='color:#1F497D'>sapphire, </span>Bi2Se3 and Nb<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l1 level1 lfo2'><![if !supportLists]><span style='mso-list:Ignore'>b.<span style='font:7.0pt "Times New Roman"'> </span></span><![endif]>The device is made by MBE and ion-milling, so the device (and exposed area of Bi2Se3 and Nb) is quite small<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l1 level1 lfo2'><![if !supportLists]><span style='mso-list:Ignore'>c.<span style='font:7.0pt "Times New Roman"'> </span></span><![endif]>Because of MBE, the Bi2Se3 is quality grade and “clean”<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l1 level1 lfo2'><![if !supportLists]><span style='mso-list:Ignore'>d.<span style='font:7.0pt "Times New Roman"'> </span></span><![endif]>They prefer pre-clean with only acetone and IPA (based on some limited experience of acid damage to the device)<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Your advice will be most appreciated.<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><o:p> </o:p></p><p class=MsoNormal>Warren Lai, Ph.D.<o:p></o:p></p><p class=MsoNormal>Associate Director<o:p></o:p></p><p class=MsoNormal>Micro Electronics Research Laboratory (MERL)<o:p></o:p></p><p class=MsoNormal>Electrical and Computer Engineering Department<o:p></o:p></p><p class=MsoNormal>Rutgers, The State University of New Jersey<o:p></o:p></p><p class=MsoNormal>Room EE-115<o:p></o:p></p><p class=MsoNormal>94 Brett Road, Piscataway, NJ 08854<o:p></o:p></p><p class=MsoNormal>732-445-0680<o:p></o:p></p><p class=MsoNormal><a href="mailto:warren.lai@rutgers.edu">warren.lai@rutgers.edu</a><o:p></o:p></p><p class=MsoNormal><a href="http://www.merl.rutgers.edu">www.merl.rutgers.edu</a><o:p></o:p></p><p class=MsoNormal><a href="http://www.ece.rutgers.edu">www.ece.rutgers.edu</a><o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>