Kamal Mundoli

Time-of-Flight Elastic Recoil Detection Analysis (ToF-ERDA) measurement for determining the elemental concentrations of thin films. ToF-ERDA is capable of identifying all elements, including various hydrogen isotopes. It provides elemental depth profiles by determining the concentration of each element at different depths within a sample. Typically, the method achieves detection limits ranging from 0.1 to 0.5 atomic percent and depth resolution between 5 and 20 nm. It is suitable for analyzing films with thicknesses between 20 and 500 nm. For accurate measurements, the sample surface should be smooth, with a roughness of less than 10 nm. The method is inherently quantitative when analyzing thin films on typical substrates, such as silicon (Si), gallium nitride (GaN), silicon carbide (SiC), gallium arsenide (GaAs), or indium phosphide (InP). So, reference samples are not needed to obtain quantitative results. The technique is particularly useful when analyzing light elements due to its good detection limits. In addition to typical ToF-ERDA measurements, we also offer LI-ERDA (also referred to as Foil ERDA) for more precise determination of hydrogen isotopes. The detection limits with LI-ERDA are typically around 0.01 atomic percent, and depth resolutions of ~1nm can be achieved. LI-ERDA only allows detection of hydrogen isotopes.

X-Ray Reflectometry (XRR) analysis is used to measure the density (g/cm3), thickness (nm), and roughness (nm) of thin films. The method is applicable to the characterization of single- or multilayered thin films, as it provides information on the thickness and density of individual layers of the sample material as well as the roughness of the interphases. Greatest accuracy for XRR thickness measurements is generally achieved for samples containing 1-150 nm thick surface layers with under 5 nm RMS roughness. Thicker films and coatings with rougher surfaces can also be characterized, but the accuracy of thickness determination decreases as the thickness and roughness of the film or film stack increase. >150 mm wafers are typically cut to fit the sample holder. Please let us know if you need testing for larger wafers that cannot be cut into pieces. The available temperature range for XRR measurements is 25-1100 °C, and crystallinity can be studied as a function of temperature. The measurements can be performed under a normal atmosphere, inert gas, or vacuum. Measurements are typically performed using one of the following instruments: Rigaku SmartLab, Panalytical X'Pert Pro MRD, Bruker D8 Discover. Please let us know if you have a preference for a specific instrument.

In this analysis, the surface roughness value (RMS) of the sample is determined with atomic force microscopy (AFM), typically with the Bruker Dimension Icon as the instrument. Three measurement points from the sample are included in a typical analysis. The measurement area is 5 x 5 micrometers, if not otherwise agreed. In addition to the RMS value, a 2D image, a 3D image, and raw data will be included in the test report.

The combination of grazing incidence X-ray diffraction (GI-XRD) and X-ray reflectometry (XRR) analysis is used to determine the following properties of thin film samples: XRR density (g/cm3), thickness (nm),, roughness (nm). GI-XRD XRD spectrum and identification of the phase(s), Crystallinity, crystallite size, lattice parameters, and strain of the phase. NOTE: These parameters are determined if samples are highly crystalline. Determination may not succeed if crystallinity is insufficient.. Notes about suitable samples XRR - The method is applicable to the characterization of single- or multilayered thin films, as it provides information on the thickness and density of individual layers of the sample material as well as the roughness of the interphases. The greatest accuracy for XRR thickness measurements is generally achieved for samples containing 1-150 nm thick surface layers with under 5 nm RMS roughness. Thicker films and coatings with rougher surfaces can also be characterized but, the accuracy of thickness determination decreases as the thickness and roughness of the film or film stack increases. GI-XRD - the method is generally applicable for samples that are suitable for XRR. The only special criterion is crystallinity - the investigated phases must be crystalline to produce XRD data. Available conditions By default, the GI-XRD and XRR measurements are performed under ambient conditions, but temperatures from 25 to 1,100 °C can be used, and the properties studied as a function of temperature. Measurements can also be done under inert gas or vacuum if needed. Please contact our experts if you need XRR and/or GI-XRD measurements or if you need more information on the analysis or suitable samples.