Depth profiling of Irganox‐3114 nanoscale delta layers in a matrix of Irganox‐1010 using conventional Cs⁺ and O₂⁺ ion beams

Abstract

a Depth profiling of an organic reference sample consisting of Irganox 3114 layers of 3 nm thickness at depths of 51.5, 104.5, 207.6 and 310.7 nm inside a 412 nm thick Irganox 1010 matrix evaporated on a Si substrate has been studied using the conventional Cs + and O 2 + as sputter ion beams and Bi + as the primary ion for analysis in a dual beam time-of-flight secondary ion mass spectrometer. The work is an extension of the Versailles Project on Advanced Materials and Standards project on depth profiling of organic multilayer materials. Cs + ions were used at energies of 500 eV, 1.0 keV and 2.0 keV and the O 2 + ions were used at energies of 500 eV and 1.0 keV. All four Irganox 3114 layers were identified clearly in the depth profile using low mass secondary ions. The depth profile data were fitted to the empirical expression of Dowsett function and these fits are reported along with the full width at half maxima to represent the useful resolution for all the four delta layers detected. The data show that, of the conditions used in these experiments, an energy of 500 eV for both Cs + beam and O 2 + beam provides the most useful depth profiles. The sputter yield volume per ion calculated from the slope of depth versus ion dose matches well with earlier reported data.

Effect of magnetic fullerene on magnetization reversal created at the Fe/C60 interface

“…The depth profile data clearly shows the multilayer structure of MgO (001)/Fe(15 nm)/C 60 (40 nm)/Ta(3 nm) (Sample B) accordingly as per the proper growth structure. The high resolution TOF-SIMS 28 , 29 clearly ressolves the individual layers of the sample. The profile starts with high intensity of Ta (Green) along with O (Red) represents the top most layer and it starts decreasing when the intensity of C 60 (Blue) rises up.…”

Depth resolution in sputter profiling revisited

“…Thin layers (delta layers) have become rather popular to test the depth resolution in SIMS, which is frequently given as FWHM of the measured layer profile . The ‘true’ FWHM of the resolution function, Δ z (FWHM), is given for a delta layer which is mathematically defined for thickness d → 0.…”

“…The best experimental approximation to a delta layer is an atomic monolayer, for which the deviation from the delta layer profile usually is below 1% and therefore can be ignored . Sometimes, layers with thickness of nanometer dimensions are termed (and treated) not quite correctly as ‘delta layers’ if they are sandwiched between thicker layers of different composition . For example, this situation is encountered in the organic standard multilayer material Irganox used for calibrations of cluster ion sputtering, where the single layer thickness is 8.5 nm, a typical case for the application of Eqns or .…”

“…Sometimes, layers with thickness of nanometer dimensions are termed (and treated) not quite correctly as ‘delta layers’ if they are sandwiched between thicker layers of different composition . For example, this situation is encountered in the organic standard multilayer material Irganox used for calibrations of cluster ion sputtering, where the single layer thickness is 8.5 nm, a typical case for the application of Eqns or . For the practical analyst, the implicit Eqns or for Δ z (FWHM) can be replaced by an approximate, direct solution which treats the layer thickness d as a distortion of the true Δ z (FWHM) for d ➔ 0.…”

“…In an earlier publication, Zalm has proposed an adding up of the contributions with an exponent of 4: …”