Hi, I would like to know the chemical composition of a thin film on a Si wafer.
I think MEIS and AES analysis are usually taken to know chemical composition.
As I know, MEIS is one of the most accountable ways to confirm chemical composition with depth profiling.
AES results are not corrected, so these need to be revised.(e.g. according to MEIS results)
Then, is it okay not to analyze AES? Please could anyone explain what the differences are between those two? Thank you.
If you are only interested in the stoichiometry of the layer then MEIS is the better choice. It does not need reference spectra or relative sensitivity factors (RSF) for quantification. It is also independent of inelastic mean free path lenghts of the Auger electrons and therefore it is in this respect matrix insensitive. Also the detection limit of MEIS is better than the one of Auger.
AES has much better lateral resolution than MEIS and you can measure the lateral homogeneity of your layer. With Auger you have also chemical information and you can see if your layer is oxidic or metallic or sometimes you can distinguish different alloys. You can also see peak shifts in semiconducts due to doping.
in addition to what Martin Arndt already reported, keep in mind that you are unable to detect elements that are lighter than you projectile ion, i.e. by using Ne-ions you won't be able e.g. to detect oxygen, carbon or nitrogen, and the situation gets even worse for Ar as the probe ion. Using noble gas ions you'll only get information about the outermost layer of your sample, and thus, you may need some sputter removal (e.g. for removal of contaminations) prior to any MEIS analysis. For a sputter depth profiling, you need to take preferential sputtering etc. into account.
So I feel a combination of both techniques, eventually in combination with SIMS may be required depending on the sample you are interested in! Good luck, Dirk
I think an appropriate method depends on the problem you have: the elements analyzed, the thickness of the film, etc. As it was mentioned above by Dirk, you cannot analyze with MEIS some elements lighter than primary ion. You cannot analyze H with AES, and so on. If you interesting in chemical analysis, you need XPS method. If your film is quite thick (more than 400nm), EDX for volume analysis and RBS method for in depth analysis will be a better chose. SIMS can be applied as well (for H analysis just without alternative).
- Badges
- Science topic
- Similar topics
- Chemistry
- Nanotechnology
- Nanostructures
- Thin Films