Surface cleanness of substrate transported by XHV integrated process

The extreme high vacuum integrated process has been developed in order to transfer substrates among vacuum chambers without any contamination on the ultra clean surface. The integrated process has ®ve main line chambers, six sidetrack chambers, connector chambers and six vacuum instrument chambers for surface analyses and ®lm preparation. Magnetic levitation transports are installed into the line chambers because they have no sliding part to generate dust particles as well as outgassing which may much damage the ultra clean substrate surfaces and environment. The levitation transports can transfer a substrate among connected six chambers in the pressure change of less than 10ÿ10 Pa. Auger analysis shows that surface of a Cu coated steel substrate prepared in the ®lm preparation chamber can be kept clean without oxygen nor carbonate during the transportation from the ®lm preparation chamber to the auger analysis chamber. # 2001 Elsevier Science B.V. All rights reserved.