Dear Dr. Elbright Dillu ,

I suggest you to have a look at the following, interesting paper:

-Towards reliable X-ray photoelectron spectroscopy: Sputter-damage effects in transition metal borides, carbides, nitrides, and oxides

G.Greczynski,. L.Hultman

Applied Surface Science, Vol. 542, 148599 (2021)

Available at: https://www.sciencedirect.com/science/article/pii/S0169433220333572

My best regards, Pierluigi Traverso.

Elbright Dillu it can depend on the film you are trying to analyze and what the etch rate of that film is. One thing that I used to do is a depth profile, this way you can measure carob content as a function of the sputtering time. You can observe the decrease in carbon over time and if you see your substrate you've gone too far!

Alternatively i've used a GCIB (Gas Cluster Ion Beam) to sputter the surface which has a much slower etch rate than typical Ar sputtering.

Good Luck!

Adam

Dear Elbright, if you simply want to remove contaminations from the surface, then I would use a small Ar-ion energy (say about 3 keV or even less) and 30 s should be enough if you have a "normal“ ion gun such as the IQP 10/63 from specs (see specs-group.com) with some few 10 microamp of sputter current. If you want to remove a surface oxidation or similar (due to the contact of a reactive sample with laboratory air etc) then higher energy (typically 3,5 to 4 keV) and a longer time (few minutes) are recommended. Details depend on your actual ion gun, the current (more specifically current density) on the sample as well as on your sample, but the numbers above are a first idea, and I should say that we made good experience with those in the past for different sample systems.

But, as Luigi Traverso has mentioned above, take care of sputter damages. As Adam has mentioned as well, a cluster gun is preferred, but you may not have such a device in your system.

good luck, Dirk