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Sunday, July 12, 2020

#439 Surface aging

Surfaces of semiconductor wafers during handling, storage, shipping, etc., are unavoidably exposed to moisture, oxygen, and volatile organic compounds present in the surrounding ambient air regardless of whether it is an ultra-clean clean-room, plastic shipping container, or storage box.


The process of adsorption on the wafer surface of the air-born species listed above gradually changes chemical composition of such surface and accounts for what’s known as surface” aging”. As a result, in the matter of days regardless of whether initially hydrophobic or hydrophilic, surface is losing its original wetting characteristics reflecting changes in the surface energy. At its early stage the process of surface “aging” can be reversed by means of the discussed in the previous blog lamp cleaning. If allowed to continue for the longer period of time (e.g. prolonged storage of wafers between processes), only conventional wet cleaning is able to return the surface to its original condition.

Posted by Jerzy Ruzyllo at 05:13 PM | Semiconductors | Link is a personal blog of Jerzy Ruzyllo. He is Distinguished Professor Emeritus in the Department of Electrical Engineering at Penn State University. With over forty years' experience in academic research and teaching in semiconductor engineering he has a unique perspective on the developments in this technical domain and enjoys blogging about it.

This book gives a complete account of semiconductor engineering covering semiconductor properties, semiconductor materials, semiconductor devices and their uses, process technology, fabrication processes, and semiconductor materials and process characterization.

With over 2000 terms defined and explained, Semiconductor Glossary is the most complete reference in the field of semiconductors on the market today.


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