Field enhancement effect in reactive ion etching – a novel mechanism for plasma processing and plasma diagnostics
Field enhancement effect (FEE) is a physical phenomenon widely investigated in the context of field emitters and nanophotonic devices, where electromagnetic fields can be enhanced significantly at geometrically sharp boundaries. Here, we propose and report the FEE in the plasma sheath when geometric...
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| Format: | Article |
| Language: | English |
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Elsevier
2025-06-01
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| Series: | Materials & Design |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S0264127525005647 |
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| author | Bingdong Chang Gwendoline A.E. Anand Xiyuan Liu Henri Jansen Lucia Romano Anpan Han |
| author_facet | Bingdong Chang Gwendoline A.E. Anand Xiyuan Liu Henri Jansen Lucia Romano Anpan Han |
| author_sort | Bingdong Chang |
| collection | DOAJ |
| description | Field enhancement effect (FEE) is a physical phenomenon widely investigated in the context of field emitters and nanophotonic devices, where electromagnetic fields can be enhanced significantly at geometrically sharp boundaries. Here, we propose and report the FEE in the plasma sheath when geometrically sharp silicon microstructures are plasma processed by reactive ion etch (RIE). When a thin film covers the silicon structures, argon ions preferentially etch the thin films at sharp geometries due to FEE. The FEE “hotspots” are clearly visualized by adding a subsequent isotropic RIE process using SF6 chemistry. We correlated the dimensions of the hotspot profiles to the field enhancement factor (FEF). Finite element methods investigated the dependence of tip aspect ratio, the FEF, and the dimensions of hotspot profiles for hemisphere-on-cone and elliptic geometries. The critical FEF was determined to be 1000 to 2500 with Si substrate and a specified plasma condition. The knowledge gained from this study predicts FEE in plasma processing, and we apply it to fabricate nanocavities and large- area mapping electric fields for plasma diagnostics. Our study provides new insights into the plasma processing of sharp geometries, which are essential for robust chip fabrication, as the device size shrinks due to Moore’s Law and FEE in device fabrication becomes ubiquitous. |
| format | Article |
| id | doaj-art-c5ba2c8b986641778abda8eaa2d4a1ab |
| institution | OA Journals |
| issn | 0264-1275 |
| language | English |
| publishDate | 2025-06-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Materials & Design |
| spelling | doaj-art-c5ba2c8b986641778abda8eaa2d4a1ab2025-08-20T02:09:11ZengElsevierMaterials & Design0264-12752025-06-0125411414410.1016/j.matdes.2025.114144Field enhancement effect in reactive ion etching – a novel mechanism for plasma processing and plasma diagnosticsBingdong Chang0Gwendoline A.E. Anand1Xiyuan Liu2Henri Jansen3Lucia Romano4Anpan Han5DTU Construct, Technical University of Denmark, 2800 Kongens Lyngby, Denmark; Corresponding authors.DTU Construct, Technical University of Denmark, 2800 Kongens Lyngby, DenmarkDTU Construct, Technical University of Denmark, 2800 Kongens Lyngby, DenmarkDTU Nanolab, Technical University of Denmark, 2800 Kongens Lyngby, DenmarkInstitute for Biomedical Engineering, ETH Zurich, Zurich 8092, Switzerland; Center for Photonic Science, Paul Scherrer Institute, Villigen 5232, SwitzerlandDTU Construct, Technical University of Denmark, 2800 Kongens Lyngby, Denmark; Corresponding authors.Field enhancement effect (FEE) is a physical phenomenon widely investigated in the context of field emitters and nanophotonic devices, where electromagnetic fields can be enhanced significantly at geometrically sharp boundaries. Here, we propose and report the FEE in the plasma sheath when geometrically sharp silicon microstructures are plasma processed by reactive ion etch (RIE). When a thin film covers the silicon structures, argon ions preferentially etch the thin films at sharp geometries due to FEE. The FEE “hotspots” are clearly visualized by adding a subsequent isotropic RIE process using SF6 chemistry. We correlated the dimensions of the hotspot profiles to the field enhancement factor (FEF). Finite element methods investigated the dependence of tip aspect ratio, the FEF, and the dimensions of hotspot profiles for hemisphere-on-cone and elliptic geometries. The critical FEF was determined to be 1000 to 2500 with Si substrate and a specified plasma condition. The knowledge gained from this study predicts FEE in plasma processing, and we apply it to fabricate nanocavities and large- area mapping electric fields for plasma diagnostics. Our study provides new insights into the plasma processing of sharp geometries, which are essential for robust chip fabrication, as the device size shrinks due to Moore’s Law and FEE in device fabrication becomes ubiquitous.http://www.sciencedirect.com/science/article/pii/S0264127525005647Field enhancement effect (FEE)Plasma processingReactive ion etchingSilicon microstructuresPlasma sheath |
| spellingShingle | Bingdong Chang Gwendoline A.E. Anand Xiyuan Liu Henri Jansen Lucia Romano Anpan Han Field enhancement effect in reactive ion etching – a novel mechanism for plasma processing and plasma diagnostics Materials & Design Field enhancement effect (FEE) Plasma processing Reactive ion etching Silicon microstructures Plasma sheath |
| title | Field enhancement effect in reactive ion etching – a novel mechanism for plasma processing and plasma diagnostics |
| title_full | Field enhancement effect in reactive ion etching – a novel mechanism for plasma processing and plasma diagnostics |
| title_fullStr | Field enhancement effect in reactive ion etching – a novel mechanism for plasma processing and plasma diagnostics |
| title_full_unstemmed | Field enhancement effect in reactive ion etching – a novel mechanism for plasma processing and plasma diagnostics |
| title_short | Field enhancement effect in reactive ion etching – a novel mechanism for plasma processing and plasma diagnostics |
| title_sort | field enhancement effect in reactive ion etching a novel mechanism for plasma processing and plasma diagnostics |
| topic | Field enhancement effect (FEE) Plasma processing Reactive ion etching Silicon microstructures Plasma sheath |
| url | http://www.sciencedirect.com/science/article/pii/S0264127525005647 |
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