Peltier cooling for the reduction of carbon contamination in scanning electron microscopy

Mia San Gabriel; Dian Yu; Iliya Mekuz; Boran Kumral; Ehsan Nikbin; Tobin Filleter; Jane Y Howe

doi:10.1016/j.micron.2023.103499

Peltier cooling for the reduction of carbon contamination in scanning electron microscopy

Micron. 2023 Sep:172:103499. doi: 10.1016/j.micron.2023.103499. Epub 2023 Jun 7.

Authors

Mia San Gabriel¹, Dian Yu², Iliya Mekuz³, Boran Kumral⁴, Ehsan Nikbin², Tobin Filleter⁴, Jane Y Howe⁵

Affiliations

¹ Department of Materials Science and Engineering, University of Toronto, 184 College St, Toronto, ON, Canada. Electronic address: mia.sangabriel@mail.utoronto.ca.
² Department of Materials Science and Engineering, University of Toronto, 184 College St, Toronto, ON, Canada.
³ Hitachi High-Tech Canada Inc., Toronto, Canada.
⁴ Department of Mechanical & Industrial Engineering, University of Toronto, 5 King's College Road, Toronto, ON, Canada.
⁵ Department of Materials Science and Engineering, University of Toronto, 184 College St, Toronto, ON, Canada; Department of Chemical Engineering, University of Toronto, 200 College St, Toronto, ON, Canada. Electronic address: jane.howe@utoronto.ca.

PMID: 37343389
DOI: 10.1016/j.micron.2023.103499

Abstract

We used a novel Peltier anticontamination device (PAC) to reduce carbon contamination upon electron beam irradiation in scanning electron microscopy through a reduction of hydrocarbon molecules in the specimen chamber. Unlike liquid-nitrogen based cold traps, the PAC operates free of user maintenance and is suitable for lengthy imaging sessions without degradation of the anticontamination performance. Its performance as an alternative cold trap method provides considerable reduction of electron beam-assisted carbon build-up. We compared the thickness of carbon contamination deposited upon prolonged electron beam scans with the PAC system on and off. Topographical structures of the carbon build-up were characterized using atomic force microscopy. We report that under identical beam parameters, thickness of the carbon contamination was reduced by over 79 % for area scans (1.2 × 1.2 µm²), and by two orders of magnitude for stationary point scans when the PAC cooling mode is engaged.

Keywords: Anticontamination device; Hydrocarbon contamination; Peltier cooling; Scanning electron microscopy.