학술논문

Enrichment of daughter nuclides of natural alpha-decay series in high purity aluminum for LSI fabrication.
Document Type
Article
Source
Journal of Radioanalytical & Nuclear Chemistry. Jan2003, Vol. 255 Issue 1, p201-205. 5p.
Subject
*RADIOISOTOPES
*ALPHA decay
*RADIOACTIVE decay
*URANIUM isotopes
*THORIUM isotopes
*NUCLEAR chemistry
*RADIOCHEMISTRY
Language
ISSN
0236-5731
Abstract
Uranium and thorium isotopes were determined in highly pure aluminum for LSI fabrication by alpha-spectrometry utilizing natural 147Sm as an inner standard. Daughter nuclides in natural decay series are found in an enrichment state from radioactive equilibrium. Unexpected contamination that had a ground water origin was supposed to explain the enrichment. This finding suggests strongly that alpha-spectrometry is still quite an important technique to evaluate soft-error probability for modern memory device materials since highly sensitive instrumental analysis such as ICP-MS is not sensitive enough to short-lived alpha-emitters. [ABSTRACT FROM AUTHOR]