Dear community,
I performed XRR measurements on thin film AuAgSi alloys deposited on Si substrate, please see attached image. For simulation i included 2 nm of SiO2 on top of the substrate and i added an extra-layer (3-5 nm thick) on top of the film. As i understand, the simulation worked not bad except for the very clear feature at 2-theta of about 1.1 which was not captured. This feature is reproducible and appears in the whole batch. The measured film thickness is 25 nm.
Do you have any idea what can cause such feature in XRR spectra before the first interference fringe? Or it is not important and can be ignored?
Thank you!
Dear Oleksandr Glushko ,
the steepness of the total reflection cut off (around the critical angle of total reflection) is governed by the imaginary part (beta) of the refractive index, and thus of the attenuation. The higher the attenuation is, the more flat the cut-off of the reflection curve will be.
So in your case you have to lower the attenuation a bit in your calculation, in order to get a steeper cut-off of your blue curve there.
Experimental thin films in general are smaller in density compared to known bulk values.
Just play around with the density (and even with the stoichiometry) of your AuAgSi film.
Good luck and best regards
G.M.
Dear Gerhard Martens,
thanks a lot for your answer! The problem is that i was not able to find any value of density which would give a better fit. Now knowing that beta is responsible for the steepness i will give it another try.
Best regards,
Oleksandr
- Badges
- Science topic
- Similar topics
- Physical Sciences
- Materials Science
- Materials
- Inorganic Materials
- Metals
- Alloys