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Detection of surface impurities on Si wafers using total reflection x‐ray photoelectron spectroscopy
Author(s) -
Iijima Yoshitoki,
Miyoshi Kousuke,
Saito Shuichi
Publication year - 1999
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/(sici)1096-9918(199901)27:1<35::aid-sia461>3.0.co;2-#
Subject(s) - x ray photoelectron spectroscopy , wafer , analytical chemistry (journal) , detection limit , impurity , spectrometer , materials science , x ray , reflection (computer programming) , total internal reflection , optics , chemistry , optoelectronics , physics , nuclear magnetic resonance , chromatography , computer science , programming language , organic chemistry
Total reflection x‐ray photoelectron spectroscopy(TRXPS) has been applied to measure contamination elementson Si wafers using an x‐ray photoelectron spectrometer. Theradiated x‐rays are limited by a slit placed in front of theAl anode, and the grazing angle is made shallow by using a crystal tomake it possible for parallel x‐rays to radiate the samplesurface. In this experiment, the grazing angle of x‐rays(Al Kα) was 1.1°, which satisfies the totalreflection condition. The samples used are Si wafers contaminatedwith Fe and Cu. It is observed that the background intensity ofphotoelectron spectrum decreases with the penetration depth ofx‐rays, but the photoelectron peak intensity does not decreaseremarkably. The detection limit of TRXPS was found to be 9×10 10 atoms cm ‐2 for Fe and Cu contaminationon Si wafers. As a result, the detection limit of TRXPS has beenimproved to more than 100 times in comparison with that ofnormal‐type XPS. Accordingly, it can be said that TRXPS is avery effective method for the contamination analysis of Si wafers.© 1999 John Wiley & Sons, Ltd.