Quantifying low fluence ion implants in diamond-like carbon film by secondary ion mass spectrometry by understanding matrix effects

Abstract

Secondary ion mass spectrometry (SIMS) data from diamond like carbon (DLC) often give inaccurate, imprecise results when methods tailored for silicon are applied. This work is a guide to accurate and precise results from future SIMS analyses of DLC.

Depth profiling and standardization from the back side of a sample for accurate analyses: Emphasis on quantifying low‐fluence, shallow implants in diamond‐like carbon

“…Herein, we correct for these effects using templates and SRIM models. Again, because ions do not appear to move after implantation into DLC, 8,12 SRIM appears to give excellent extrapolations of the SW depth profiles near the sample–epoxy interface. Some depth profiles appeared stretched, probably due to ion mixing or, perhaps, “smearing” (e.g.…”

“…In addition, a corrected back‐side analysis of the reference implant could be used as a template (scaled to match the intensity of the peak and sputtering rate) to accurately correct other depth profiles 12 . In many cases, the magnitude of these corrections was within ca 6% of a straight‐line extrapolation to the surface used as a preliminary estimate 8 …”

“…This difficulty is compounded by a further complication that – upon return to Earth – the solar wind collectors were shattered and their surfaces were exposed to terrestrial contaminants and spacecraft debris due to an unplanned, spectacular hard landing 4–6 . Many of the contaminants and debris could not be removed without risking damage to the precious, near‐surface SW sample 1,6–8 . Flight silicon collectors were easily etched at the nanometer scale by standard semiconductor cleaning techniques and this etching was clearly affected by the radiation damage caused by the SW implantation itself 7,9 .…”

“…Genesis DLC is an inhomogeneous materiala combination of graphite and diamond. In previous work on Mg isotopes in DLC, 8,12 we looked at the yield of ( 24 MgH + 25 Mg)/ 24 Mg versus the yield of 26 Mg/ 24 Mg. From our data we were able to infer that 24 MgH was not correlated with 25 Mg. Rather, its abundance appeared to be a function of the heterogeneous matrix.…”

ToF-SIMS Depth Profiling of Metal, Metal Oxide, and Alloy Multilayers in Atmospheres of H2, C2H2, CO, and O2

“…On the other hand, all of the material sputtered during the etching process is lost . In addition to the deterioration of the depth resolution and ion-bombardment-induced damage, the application of SIMS is also limited by the matrix effect and the nonconstant ionization yields. − The matrix effect is the effect of the substrate on the ionization probability of the particles emitted from the surface, both increasing or decreasing the ionization yield of either positive or negative secondary ions depending on the substrate from which they originate. − The matrix effect is particularly critical for (semi)­quantitative analyses. ,, …”