GD-OES: Multilayer elemental depth profile
Most materials today are multilayered (automotive bodies, LED, photovoltaic thin films, hard disks, electrodes for Li batteries, coated glasses, etc.) or they feature surface treatments and coatings in order to enhance performance, to improve mechanical properties or to strengthen corrosion resistance (nitrides, biocompatible surfaces, advanced oxides, etc.)
In this context, pulsed RF GD-OES is the ideal analytical technique for studying layered materials as well as their process control. It offers ultrafast elemental depth profile analysis of thin and thick layers, conducting or isolating, with high sensitivity to all elements.
With a typical erosion rate of µm/min (2-10 nm/s), pulsed RF GD-OES is ultra fast. Researchers and users are therefore encouraged to run multiple samples or do multiple measurements on any specimen. The immediate feedback allows them to check for material homogeneity, to optimize and control each stage of their evaporation, deposition or annealing processes and to quickly react to any observed variation. Even polymeric layers are sputtered ultra fast without damage, due to HORIBA’s patented “UFS” system.
Nanometric depth resolution
Pulsed RF GD-OES offers superb depth resolution, down to the nanometre scale or below, made possible by the unique characteristics of the advanced pulsed RF GD source and the patented High Dynamic Detection capability of the optical system.
Optimum spectral coverage
High Dynamic and Ultra-Fast Optical Detection allows simultaneous measurement of all elements of interest in the depth profiles from ppm levels to 100%. The proprietary HORIBA diffraction gratings allow optimum measurements of emission lines ranging from the VUV (120 nm for H and its isotope D, 130 nm for O, etc.), to the IR for Li (670 nm) and K (766 nm).
Qualitative and quantitative depth profiles of thin and thick films
Surface sensitive techniques (XPS or SIMS) are slow and fail to measure layers of more than 1 micrometre. For thicker layers, SEM EDX on cross sections can be used, but require tedious preparation and cannot measure light elements.
Pulsed RF GD-OES, on the other hand, rapidly sputters tens of micrometres of conductive and non-conductive materials, measures all elements and is therefore ideal both for thin and thick layers.
Within the pulsed RF GD source, erosion and emission are spatially separated. Erosion is material dependent and measured with DiP. Excitation takes place in the gas phase only and uniquely relates to the plasma conditions and emission lines intensities are directly proportional to the concentrations in the plasma. Conversion from measured signals (intensities vs time) to quantitative results (concentrations vs depth) is therefore straightforward.