News and features in device applications, processes, and materials, being applied in today's microelectronics industry

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 193 KB
• Volume: 28
• Category: Article
• ISSN: 0026-2692
• DOI: 10.1016/s0026-2692(97)84513-2

✦ Synopsis

With the sub-micron geometries of today, standards call for a level of cleanliness ten thousand times stricter than that permitted in an operating room (Clean Room Class 1). One cubic foot of air -about 28 litres -may contain at most three particles measuring 0.3 ~tm diameter. To remove even the most stubborn dust particles, millions of cubic metres of air are pumped through a typical modem clean room each and every hour. Employees are covered from head to foot with special protective clothing. The next step 'would appear to be "Clean Rooms Class 0.1" -production areas with fewer than three 0.1 ~tm particles per cubic foot of air. Workers in this type of clean room will have to wear spacesuits equipped with independent air supplies. The alternative is the ,;eparation of "wafers and workers," and this is already taking place as the wafers are transported in SMIF boxes (Standard Mechanical Interface) that carry the ultraclean air with them. The hermetically sealed boxes are only opened at the airlocks at each processing station -by robots. Since workers never come into contact with the sensitive chip structures, the dust-free atmosphere is only necessary in the immediate vicinity of the wafer. This new concept is implemented on a large scale at the Siemens North Tyneside chip factory near Newcastle, in England,

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