| AVS 65th International Symposium & Exhibition | |
| Vacuum Technology Division | Tuesday Sessions |
| Session VT-TuP |
| Session: | Vacuum Technology Division - Poster Session |
| Presenter: | Andras Vladar, National Institute of Standards and Technology (NIST) |
| Authors: | A.E. Vladar, National Institute of Standards and Technology (NIST) K. Purushotham, National Institute of Standards and Technology (NIST) |
| Correspondent: | Click to Email |
Electron and ion beam-induced contamination could be a severe problem of scanning electron microscopes. The carbonaceous material deposited in a dynamic process of adsorption and desorption at the irradiated area can easily disturb imaging and lead to erroneous measurement results. The sources of contamination are usually both the SEM and the sample. Cleaning of the SEM can be carried out with a low-energy (oxygen) plasma cleaning process using commercial devices [1], but without a for-sure-clean sample, it is not possible to determine whether potentially time-consuming cleaning of the SEM is indeed necessary. The RGM 10100 sample with its associated cleaning and evaluation procedures, combined with appropriate cleaning processes offer an effective solution for this problem.
Figure 1 in the supplement shows three levels of SEM cleanliness. The energetic primary electrons can “purge” the center of the sample from carbonaceous contaminant molecules. The center brightening is due to slight oxidation caused by electron irradiation at 40 times the typical dose. With a clean RGM 10100 in a SEM there is no perceivable carbonaceous contamination even after many hours of continuous electron bombardment.
RGM 10100 can be cleaned with acidic piranha solution and can stay clean for months in a semiconductor grade plastic container. The necessary SEM cleaning time, depending on the cleanliness of the SEM, varies from 10 minutes to a couple of days. It is common that the contamination “comes back” after some time. As the SEM gradually becomes free of the source molecules of contamination, the time between needed cleanings could increase to months. RGM 10100 is available from the NIST Office of Reference Materials.
[1] http://evactron.com [http://evactron.com/], http://ibssgroup.com [http://ibssgroup.com/], http://www.piescientific.com [http://www.piescientific.com/]
+Author for correspondence: andras@nist.gov [mailto:andras@nist.gov]