I am using PHI nano TOF II TRIFT SIMS from Physical Electronics, MN, USA. I have grown Phosphorus doped silicon thin film (200nm) on glass using HWCVD. I need to detect P-31 isotope along with the Si-30 matrix element for the ion count to concentration conversion using RSF procedure. But to enhance the P-31 counts, operator avoided the Si-30 isotope. How can I solve this?
Can you specify what you mean by "operator avoided the Si-30 isotope"? Is your ToF-SIMS equiqqed with a massgate that cuts away the substrate mass?
Anyway, you should be measuring against a standard and P-doped Si should be readily available so you can get from relative intensities to absolute concentrations.
Dear Jürgen Weippert,
Thanks for you interest in the topic.
I have measured the silicon matrix element (30Si) of Boron dopped Silicon wafer. Operator just did not measured the 30Si data for the Phosphorus sample saying 'to enhance the 31P counts...'
I have grown phosphorus dopped silicon thin film 1) on glass using HWCVD, and 2) Phosphorus diffused siliicon wafer in a diffusioin furnace. I have used ToF SIMS to detect 31P isotope. But there is no silicon matrix data of 30Si. Without the matrix element I could not convert the Phosphorus counts to concentration using RSF.
The operator used SIMetricSW Software to find the RSF from the peak of counts vs time curve. But this process is useful only for the phosphorus diffused silicon wafer as the matrix element is from Silicon wafer. But, I have silicon thin film on glass. Can I use the same RSF of phosphorus diffused silicon to the silicon film grown on Glass??
More later
Abul
1) Regarding the thin film vs. wafer: that is a crystallinity issue. I would expect that the absolute signal of all components from the wafer is lower than for the film because ablation might cost more energy, but I'm not aware of studies on the changes of relative sensitivities by crystallinity, so the transfer should be possible semi-decently.
2) I just checked some of my spectra (unpublished, not allowed to show) and in my case our operators worked with 28Si (Quad-Sims, not ToF). Do you have data on that? Assuming you have no isotopically enriched material, one isotope should be sufficient.
Dear Jürgen Weippert,
1. Thank you for the comments on the RSF transfer. I will work with the RSF from silicon wafer to interpret phosphorus concentration on glass. Lets see..
2. Regarding the Si-28 isotope as silicon matrix, this can be a solution. I will let the lab to know, if they can detect Si-28 along with P-31 instead of Si-30.
regards
Abul
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