Analytical and Bioanalytical Chemistry

, Volume 396, Issue 8, pp 2881–2887

Direct chemical in-depth profile analysis and thickness quantification of nanometer multilayers using pulsed-rf-GD-TOFMS

Original Paper

DOI: 10.1007/s00216-009-3382-8

Cite this article as:
Valledor, R., Pisonero, J., Bordel, N. et al. Anal Bioanal Chem (2010) 396: 2881. doi:10.1007/s00216-009-3382-8

Abstract

Nanometer depth resolution is investigated using an innovative pulsed-radiofrequency glow discharge time-of-flight mass spectrometer (pulsed-rf-GD-TOFMS). A series of ultra-thin (in nanometers approximately) Al/Nb bilayers, deposited on Si wafers by dc-magnetron sputtering, is analyzed. An Al layer is first deposited on the Si substrate with controlled and different values of the layer thickness, tAl. Samples with tAl = 50, 20, 5, 2, and 1 nm have been prepared. Then, a Nb layer is deposited on top of the Al one, with a thickness tNb = 50 nm that is kept constant along the whole series. Qualitative depth profiles of those layered sandwich-type samples are determined using our pulsed-rf-GD-TOFMS set-up, which demonstrated to be able to detect and measure ultra-thin layers (even of 1 nm). Moreover, Gaussian fitting of the internal Al layer depth profile is used here to obtain a calibration curve, allowing thickness estimation of such nanometer layers. In addition, the useful yield (estimation of the number of detected ions per sputtered atom) of the employed pulsed-rf-GD-TOFMS system is evaluated for Al at the selected operating conditions, which are optimized for the in-depth profile analysis with high depth resolution.

Keywords

Glow discharge Mass spectrometry Depth profile analysis Nanometer layers Useful yield 

Supplementary material

216_2009_3382_MOESM1_ESM.pdf (480 kb)
ESM 1(PDF 479 kb)

Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  1. 1.Department of PhysicsUniversity of OviedoMieresSpain
  2. 2.Department of PhysicsUniversity of Oviedo, CINNOviedoSpain
  3. 3.Horiba Jobin YvonLongjumeauFrance
  4. 4.Department of Physical and Analytical ChemistryUniversity of OviedoOviedoSpain

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