Issue 9, 2023

Doping density, not valency, influences catalytic metal-assisted plasma etching of silicon

Abstract

Metal-assisted plasma etching (MAPE) of silicon (Si) is an etching technique driven by the catalytic activity of metals such as gold in fluorine-based plasma environments. In this work, the role of the Si substrate was investigated by examining the effects of the dopant concentration in both n- and p-type Si and the dopant atom type in n-type Si in SF6/O2 mixed gas plasma. At the highest dopant concentrations, both n- and p-type Si initially exhibit inhibition of the MAPE-enhanced etching. As the etch progresses, MAPE initiates, resulting in catalytic etching of the underlying Si at the metal–Si interface. Interestingly, MAPE-enhanced etching increases with decreasing doping concentrations for both n- and p-type Si substrates, distinct from results for the similar but divergent, metal-assisted chemical etching of silicon in liquid. Our findings show that the metal–Si interface remains essential to MAPE, and surface enrichment of the dopant atoms or other surface chemistries and the size of metal nanoparticles play roles in modulating catalytic activity.

Graphical abstract: Doping density, not valency, influences catalytic metal-assisted plasma etching of silicon

Supplementary files

Article information

Article type
Communication
Submitted
28 apr 2023
Accepted
16 iyn 2023
First published
19 iyn 2023
This article is Open Access
Creative Commons BY license

Mater. Horiz., 2023,10, 3393-3403

Doping density, not valency, influences catalytic metal-assisted plasma etching of silicon

J. B. Sun, N. Peimyoo, J. O. Douglas and B. D. Almquist, Mater. Horiz., 2023, 10, 3393 DOI: 10.1039/D3MH00649B

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