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Quantitative analysis of impurities in HgCdTe using secondary ion mass spectrometry
Author(s) -
Lapides L. E.
Publication year - 1985
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/sia.740070503
Subject(s) - impurity , secondary ion mass spectrometry , analytical chemistry (journal) , ion , chemistry , mass spectrometry , epitaxy , materials science , layer (electronics) , chromatography , organic chemistry
SIMS has been used to analyze impurities in epitaxial layers of HgCdTe because of its sensitivity to trace impurities and because it makes it possible to obtain impurity concentration profiles through the thickness of the epitaxial layer. The impurity profiles are quantified using relative sensitivity factors calculated from ion implantation profiles obtained on standard reference samples. Unintentional impurities, such as Cu, and low‐level deliberately added impurities, such as As, In, and Ag, have been analyzed. Specialized techniques such as molecular ion spectrometry (As analysis with TeAs − ) and secondary ion acceleration voltage offset (Ag analysis) have been applied to improve sensitivity and decrease background signals. The use of these techniques has allowed the establishment of detection limits of less than 0.1 parts per billion atomic (3 × 10 15 cm −3 ). The error in the analyses is, in general, estimated to be less than ±50%. Results from relative sensitivity factor measurements and impurity profiles are presented, and detection limits and accuracy of impurity analysis in HgCdTe using SIMS are discussed.