Diffusion and interaction studied nondestructively and in real-time with depth-resolved low energy ion spectroscopy

Self Cite

To enhance the thermal stability, B 4 C diffusion barrier layers are often added to Mo/Si multilayer structures for extreme ultraviolet optics. Knowledge about the chemical interaction between B 4 C and Mo or Si, however is largely lacking. Therefore, the chemical processes during annealing up to 600°C of a Mo/ B 4 C / Si layered structure have been investigated in situ with hard x-ray photoelectron spectroscopy and ex situ with depth profiling x-ray photoelectron spectroscopy. Mo/ B/Si and Mo/C/Si structures have also been analyzed as reference systems. The chemical processes in these systems have been identified, with two stages being distinguished. In the first stage, B and C diffuse and react predominantly with Mo. MoSi x forms in the second stage. If the diffusion barrier consists of C or B 4 C, a compound forms that is stable up to the maximum probed temperature and annealing time. We suggest that the diffusion barrier function of B 4 C interlayers as reported in literature can be caused by the stability of the formed compound, rather than by the stability of B 4 C itself.

Section: Methodsmentioning

confidence: 80%

Chemical interaction of B4C, B, and C with Mo/Si layered structures

Rooij-Lohmann

Veldhuizen

Zoethout

et al. 2010

Self Cite

“…Using a recently proposed procedure, 7 these measurements provided us with the Mo concentration profile. 7. Reference 7 describes the procedure to obtain ͱ Dt from a LEIS spectrum in detail.…”

Section: A Experimental Detailsmentioning

confidence: 99%

Enhanced diffusion upon amorphous-to-nanocrystalline phase transition in Mo/B4C/Si layered systems

Rooij-Lohmann

Yakshin

Kruijs

et al. 2010

Self Cite

“…Due to the low energy applied in LEIS, noble gas ions are neutralized on penetrating the sample 16, 19,21,22 . The formation of a tail will be determined by the finite probability of these scattered neutrals to be reionized upon leaving the sample, namely the reionization probability 16,23,24 .…”

Section: Methodology Of Oxide Thickness Determination By Leis Static mentioning

confidence: 99%

Oxidation of metal thin films by atomic oxygen: A low energy ion scattering study

Boas

Sturm

Bijkerk

2019

Self Cite

In this study, we combine Low Energy Ion Scattering (LEIS) static and sputter depth profiles for characterization of the oxidation kinetics on Zr, Mo, Ru and Ta films of various thicknesses, following exposure to atomic oxygen at room temperature (∼20 • C). A method for non-destructive determination of the oxide growth rate via LEIS static depth profiling (static DP) is presented in detail. This method shows high sensitivity to the oxide thickness formed, and the results are in agreement with those obtained by X-ray reflectometry (XRR) and sputter depth profiling (sputter DP). Sequential exposures of oxygen isotopes in combination with LEIS sputter DP are applied to elucidate the growth mechanism of the oxide films. The results indicate that the oxidation kinetics at the applied experimental conditions is directly influenced by the metal work function, characterizing a Cabrera-Mott growth type. The maximum thickness of the formed oxide and oxide growth rate are in the order: Zr ≈ Ta > Mo > Ru. The combining of analysis by LEIS static DP and isotope tracing sputter DP is decisive in the characterization of oxidation kinetics in the room temperature regime.