HORIBA Scientific pulsed RF GDOES instruments have unique features supported by multiple patents that make them the ideal companion characterization tools to material research and elaboration.
The patented High Dynamic range Detectors (HDD) used in all HORIBA Scientific GD instruments allow real time, automatic optimization of the sensitivity permitting to analyze elements at trace levels in one layer and as major in a second layer without compromise or need of pre-adjustment.
Thickness Measurement using Depth Interferometry. The use of Differential Interferometry allows for continuous direct erosion rate and crater depth measurement along with the elemental depth profile analysis. This technique developed and patented by HORIBA Scientific is a major breakthrough for GD-OES as all the information, elemental composition and depth is now delivered in the same single experiment.
The analytical GD plasma is a dense plasma - about 1014 (charged particles / cm3) – but incident ions bombarding the surface have a low energy – about 50 eV and due to multiple collisions they are not unidirectional. These are the reasons for fast sputtering and excellent depth resolution as well as for low surface damage compared higher energy sputtering ion beams.
In average operating conditions, metals are sputtered at a rate of 1-5 µm / minute. A 100 nm layer could be sputtered in 3s. A thermal treatment on steel in which elements diffuse down to 50 µm could be checked in 10 min.
Most instruments feature a polychromator with Paschen Runge mounting for simultaneous measurement of the elements. This is mandatory when depth profile is central as in most Pulsed RF GD OES applications: the sputtering rate being extremely fast, the optical signals change rapidly with time and ultra fast detection is required.
Our optical spectrometers include a new generation of HORIBA Scientific holographic gratings with enhanced light efficiency, notably in the VUV range for H, O, Cl etc and patended HDD detectors.
Combined optics can also be found with monochromators added in complement to the polychromators. Being flexible, the monochromators could be tuned to any line and offer the possibility to measure extra elements with high resolution and sensitivity.
CCD systems are also available from HORIBA Scientific but limited to bulk applications or thick layers as they do not have the speed required for thin films characterisation.
The use of Differential Interferometry allows for continuous direct erosion rate and crater depth measurement along with the elemental depth profile analysis. This technique developed and patented by HORIBA Scientific is a major breakthrough for GD-OES as all the information, elemental composition and depth is now delivered in the same single experiment.
The erosion rates in GDOES are material dependent, and when multi-layers are measured, they change with depth. Previously, the estimation of these erosion rates was the result of calculations (based on recorded values for bulk materials and not well adapted to layers with varying densities) or external measurements potentially tedious.
DIP is crucially important when the investigated materials are non transparent as, in this case, Ellipsometry cannot be used.
