Removal of Fe and Al on a Silicon Surface Using UV-Excited Dry Cleaning

Rinshi SUGINO
Yoshiko OKUI
Masaki OKUNO
Mayumi SHIGENO
Yasuhisa SATO
Akira OHSAWA
Takashi ITO

Publication
IEICE TRANSACTIONS on Electronics   Vol.E75-C    No.7    pp.829-833
Publication Date: 1992/07/25
Online ISSN: 
DOI: 
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Issue on Ultra Clean Technology)
Category: 
Keyword: 
dry cleaning,  iron and aluminum,  silicon surface,  chlorine radical,  atomic absorption spectrophotometry,  

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Summary: 
The mechanism of UV-excited dry cleaning using photoexcited chlorine radicals has been investigated for removing iron and aluminum contamination on a silicon surface. The iron and aluminum contaminants with a surface concentration of 1013 atoms/cm2 were intentionally introduced via an ammonium-hydrogenperoxide solution. The silicon etching rates from the Uv-excited dry cleaning differ depending on the contaminants. Fe and Al can be removed in the same manner. The removal of Fe and Al is highly temperature dependent, and is little affected by the silicon etching depth. Both Fe and Al on the silicon surface were completely removed by UV-excited dry cleaning at a cleaning temperature of 170, and were decreased by two orders of magnitude from the initial level when the surface was etched only 2 nm deep.