<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)"><style><!--
/* Font Definitions */
@font-face
{font-family:SimSun;
panose-1:2 1 6 0 3 1 1 1 1 1;}
@font-face
{font-family:SimSun;
panose-1:2 1 6 0 3 1 1 1 1 1;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:SimSun;
panose-1:2 1 6 0 3 1 1 1 1 1;}
/* 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;}
span.EmailStyle17
{mso-style-type:personal-compose;
font-family:"Calibri","sans-serif";
color:windowtext;}
.MsoChpDefault
{mso-style-type:export-only;
font-family:"Calibri","sans-serif";}
@page WordSection1
{size:8.5in 11.0in;
margin:1.0in 1.25in 1.0in 1.25in;}
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-family:"Times New Roman","serif"'>Dear All,<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Times New Roman","serif"'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-family:"Times New Roman","serif"'>Sorry to bother you. I come from NFF in the Hong Kong University of Science and Technology. It is nice to join in this group.<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Times New Roman","serif"'>I have some questions about the material contamination in clean room.<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Times New Roman","serif"'>We have most of the research projects from department of ECE, ME, Physics, Chemical, such as, CMOS, TFT, Solar cell, SOI MEMS, LED and HENMT, micro-fluid, and so on. Right now the cleanliness level is basically defined based on the materials. <o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Times New Roman","serif"'>Highest level, Clean: Si, SiO2, Nitride, amorphous silicon, polycrystalline silicon, <o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Times New Roman","serif"'>Second, Semi-clean: Al, Ni, Ti, Mo, ITO<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Times New Roman","serif"'>Lowest level: Non-standard: others (IGZO, GaN, GaAs, Al2O3, Cu, TiW, Au, Ag, Hf, Pt and so on)<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Times New Roman","serif"'>What kind of cleanliness levels are you using? And how to define the contamination of these materials? Is it possible to promote GaN-based process to semi-clean?<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Times New Roman","serif"'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-family:"Times New Roman","serif"'>Thank you very much for your advise.<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Times New Roman","serif"'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-family:"Times New Roman","serif"'>Have a good day!<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Times New Roman","serif"'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-family:"Times New Roman","serif"'>Best,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'>Shuyun Zhao<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'>Scientific officer<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'>Nanoelectronics Fabrication Facility<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'>The Hong Kong University of Science & Technology<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'>Clear Water Bay, Kowloon, Hong Kong<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'>Tel: (852) 2358 7212/7896<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'>Fax: (852) 2358 1372<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'>Email: <i><u><span style='color:blue'><a href="mailto:nfshuyun@ust.hk"><span style='color:blue'>nfshuyun@ust.hk</span></a></span></u></i><o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>