TEM sample preparation of lithographically patterned permalloy nanostructures on silicon nitride membranes

• Joshua Williams,
• Michael I. Faley,
• Joseph Vimal Vas,
• Peng-Han Lu and
• Rafal E. Dunin-Borkowski

Beilstein J. Nanotechnol. 2024, 15, 1–12, doi:10.3762/bjnano.15.1

• resist, and the remaining SiN layer served as a hard mask for the wet etching of the substrate’s back side in 20% KOH solution. The KOH solution was heated to 60 °C to accelerate the process to an etching rate of approximately 9 μm/h in the direction perpendicular to the substrate surface. Using a warmer

Spatial mapping of photovoltage and light-induced displacement of on-chip coupled piezo/photodiodes by Kelvin probe force microscopy under modulated illumination

• Zeinab Eftekhari,
• Nasim Rezaei,
• Hidde Stokkel,
• Jian-Yao Zheng,
• Andrea Cerreta,
• Ilka Hermes,
• Minh Nguyen,
• Guus Rijnders and
• Rebecca Saive

Beilstein J. Nanotechnol. 2023, 14, 1059–1067, doi:10.3762/bjnano.14.87

• (PBZT) and a 150 nm LNO as the top electrode were deposited. The wafer was patterned by a standard photolithographic process, starting with the application and patterning of the photoresist mask for defining the device areas. Subsequently, the excess PBZT and LNO were removed by a wet etching process

Combining physical vapor deposition structuration with dealloying for the creation of a highly efficient SERS platform

• Adrien Chauvin,
• Walter Puglisi,
• Damien Thiry,
• Cristina Satriano,
• Rony Snyders and
• Carla Bittencourt

Beilstein J. Nanotechnol. 2023, 14, 83–94, doi:10.3762/bjnano.14.10

• on a metal surface induces hydrophobicity which can also affect the bonding with RhB molecules [30]. The carbon observed on the surface of the different samples is the result of the contamination of the substrate during wet etching and by the environment during storage [46]. Overall, the good

Gap-directed chemical lift-off lithographic nanoarchitectonics for arbitrary sub-micrometer patterning

• Chang-Ming Wang,
• Hong-Sheng Chan,
• Chia-Li Liao,
• Che-Wei Chang and
• Wei-Ssu Liao

Beilstein J. Nanotechnol. 2023, 14, 34–44, doi:10.3762/bjnano.14.4

• ) Schematic illustration of the post lift-off wet etching process. (B) Bright field optical microscope and atomic force microscope topography images (inset) of Au structures fabricated by gap-directed CLL using collapse-free (left) and self-collapsing (middle and right) stamps rendering triangular pillars

• followed by wet etching. Uneven regions are due to the reduced wet etching time used in order to preserve the tiny gold structures. Stamp heights are 2.25 μm (left), 2.00 μm (middle), and 1.50 μm (right). Scale bars are 100 μm. Gap-directed CLL operated with microscale parallel line shape features (W = 6

Double-layer symmetric gratings with bound states in the continuum for dual-band high-Q optical sensing

• Chaoying Shi,
• Jinhua Hu,
• Xiuhong Liu,
• Junfang Liang,
• Jijun Zhao,
• Haiyan Han and
• Qiaofen Zhu

Beilstein J. Nanotechnol. 2022, 13, 1408–1417, doi:10.3762/bjnano.13.116

• polishing and deep RIE, followed by removal of the BOX layer of the donor substrate by wet etching using hydrofluoric acid. Finally, the gratings are fabricated on the top layer with EBL and RIE, while the silicon handle and BOX layer on top are removed in the same way. It should be pointed out that the

Roll-to-roll fabrication of superhydrophobic pads covered with nanofur for the efficient clean-up of oil spills

• Patrick Weiser,
• Robin Kietz,
• Marc Schneider,
• Matthias Worgull and
• Hendrik Hölscher

Beilstein J. Nanotechnol. 2022, 13, 1228–1239, doi:10.3762/bjnano.13.102

• using various dry/wet etching techniques including electrochemical HF etching, stain etching, metal-assisted etching, and reactive ion etching [9][11]. So-called “nanograss” or “black silicon” is a surface modification of silicon where the surface is covered with millions of tiny needle-like structures

Microneedle-based ocular drug delivery systems – recent advances and challenges

• Piotr Gadziński,
• Anna Froelich,
• Monika Wojtyłko,
• Antoni Białek,
• Julia Krysztofiak and
• Tomasz Osmałek

Beilstein J. Nanotechnol. 2022, 13, 1167–1184, doi:10.3762/bjnano.13.98

• photoresistant layer. The wafer is then etched. A distinction can be made between wet and dry etching. The wet etching process uses a potassium hydroxide solution, while dry etching includes the physical methods ion milling and sputtering and the chemical method high-pressure plasma [156]. Lithographic

Optimizing PMMA solutions to suppress contamination in the transfer of CVD graphene for batch production

• Chun-Da Liao,
• Andrea Capasso,
• Tiago Queirós,
• Telma Domingues,
• Fatima Cerqueira,
• Nicoleta Nicoara,
• Jérôme Borme,
• Paulo Freitas and
• Pedro Alpuim

Beilstein J. Nanotechnol. 2022, 13, 796–806, doi:10.3762/bjnano.13.70

• as a supporting layer to (i) retain the integrity of graphene during the wet-etching bath required to dissolve the metallic substrate and (ii) provide mechanical stability when transferring graphene to the target substrates. During this process, two primary external sources of contamination need to

• /TiWN/AlSiCu/TiWN) was patterned by lift-off, followed by the CVD growth of a multi-stack layer of SiO2 and Si3N4 to passivate the current lines. After this, a thin Al2O3 layer was deposited by sputtering and patterned by wet etching to protect the gate during the graphene etch. The C4 PMMA/graphene

• films were then transferred onto the patterned wafer until all device areas were covered. After removing the PMMA, graphene was patterned using optical lithography and oxygen plasma etching. Finally, the sacrificial layer was removed by wet etching. Wafer 2: An additional layer of Al2O3 was deposited on

Electrostatic pull-in application in flexible devices: A review

• Teng Cai,
• Yuming Fang,
• Yingli Fang,
• Ruozhou Li,
• Ying Yu and
• Mingyang Huang

Beilstein J. Nanotechnol. 2022, 13, 390–403, doi:10.3762/bjnano.13.32

• performance of the switches can also be affected by the surrounding environment. Capillary forces are occurring due to the humid environment during wet etching [24]. In addition, the design of NEM switches needs to consider the unique characteristics of the materials. For example, the shape of CNTs not only

An overview of microneedle applications, materials, and fabrication methods

• Zahra Faraji Rad,
• Philip D. Prewett and
• Graham J. Davies

Beilstein J. Nanotechnol. 2021, 12, 1034–1046, doi:10.3762/bjnano.12.77

• complex multistep processes and expensive tools developed for the microelectronics industry [74][85], as introduced already. Subtractive technologies, in the form of wet and dry etching, are most frequently used. In wet etching, a single crystal silicon wafer is immersed in baths of various chemical

• symmetry to be formed. On the other hand, wet etching has lower tool costs and facilitates mass production due to simultaneous parallel fabrication using several silicon wafers at once; however, it is limited to low aspect ratio structures. Fabrication of silicon microneedle profiles generally involves

• 1 μm formed by isotropic etching with static and dynamic etching steps [88]. Bolton et al. produced tall hollow silicon microneedles by three-step DRIE process [89]. Hamzah et el. fabricated sharp solid silicon microneedles, via wet etching with HNA, with approximately 160 μm height and a base

A review of defect engineering, ion implantation, and nanofabrication using the helium ion microscope

• Frances I. Allen

Beilstein J. Nanotechnol. 2021, 12, 633–664, doi:10.3762/bjnano.12.52

• –1016 ions/cm2, the rate of subsequent wet-etching of the irradiated regions with hydrofluoric acid was found to increase by up to a factor of three (for Si3N4) and five (for SiO2). The change was attributed to ion-induced defects and demonstrates another potential form of HIM-enabled nanofabrication

Impact of GaAs(100) surface preparation on EQE of AZO/Al₂O₃/p-GaAs photovoltaic structures

• Piotr Caban,
• Rafał Pietruszka,
• Jarosław Kaszewski,
• Monika Ożga,
• Bartłomiej S. Witkowski,
• Krzysztof Kopalko,
• Piotr Kuźmiuk,
• Katarzyna Gwóźdź,
• Ewa Płaczek-Popko,
• Krystyna Lawniczak-Jablonska and
• Marek Godlewski

Beilstein J. Nanotechnol. 2021, 12, 578–592, doi:10.3762/bjnano.12.48

• deposition method is ALD [14][15]. Removal of native oxide layer and protection of such an obtained surface can be done in many ways. In the case of wet-etching techniques, the most popular GaAs native oxide etchants are based on acidic and basic solutions. In order to etch the oxide, one can treat the

Piezotronic effect in AlGaN/AlN/GaN heterojunction nanowires used as a flexible strain sensor

• Jianqi Dong,
• Liang Chen,
• Yuqing Yang and
• Xingfu Wang

Beilstein J. Nanotechnol. 2020, 11, 1847–1853, doi:10.3762/bjnano.11.166

• (EC) wet etching, to prepare AlGaN/AlN/GaN heterojunction NWs with a controllable size. After the lift-off, a single NW is transferred to a flexible poly(ethylene terephthalate) (PET) substrate and is fixed by indium tin oxide (ITO) electrodes to form an ohmic contact for the strain sensor. Under

• specific top-down two-step preparation process of freestanding AlGaN/AlN/GaN heterojunction NWs, including isotropic ICP dry etching and selective EC wet etching [25][26], is shown in Figure 2. First, a layer of photoresist was spin coated on the surface of the wafer from MOCVD, and advanced stepper

• lithography was used to form a striped pattern, which was used as a mask for ICP dry etching. The depth of the ICP dry etching needs to be greater than 1 µm (the thickness of the AlGaN/AlN/GaN heterojunction is 931.5 nm). The purpose is to expose the sacrificial layer for the subsequent EC wet etching. Then

Fabrication of nano/microstructures for SERS substrates using an electrochemical method

• Jingran Zhang,
• Tianqi Jia,
• Xiaoping Li,
• Junjie Yang,
• Zhengkai Li,
• Guangfeng Shi,
• Xinming Zhang and
• Zuobin Wang

Beilstein J. Nanotechnol. 2020, 11, 1568–1576, doi:10.3762/bjnano.11.139

• machined by using lithography-based method [15][16][17][18][19][20]. Additionally, nanostructures are also fabricated by hybrid lithography [21][22][23][24][25][26] methods combined with dry etching or wet etching. For example, the commercial Klarite substrate [21][22][23] machined by electron beam

• lithography (EBL) and wet etching consists of 1 μm deep square-based pyramidal pits in the silicon surface. A rhodamine solution (10−4 mol·L−1) is then detected using the Klarite substrate. Candeloro et al. [24] employed EBL and reactive ion etching to machine nanoholes of 400 nm diameter and 50 nm depth

Wafer-level integration of self-aligned high aspect ratio silicon 3D structures using the MACE method with Au, Pd, Pt, Cu, and Ir

• Mathias Franz,
• Romy Junghans,
• Paul Schmitt,
• Adriana Szeghalmi and
• Stefan E. Schulz

Beilstein J. Nanotechnol. 2020, 11, 1439–1449, doi:10.3762/bjnano.11.128

• nanoparticles were used to locally etch the silicon substrate. This work demonstrates a bottom-up self-assembly approach for noble metal nanoparticle formation and the subsequent silicon wet etching. The macroscopic wafer patterning has been done by using a poly(methyl methacrylate) masking layer. Different

• layer for the wet etching of silicon. The MACE process has been extensively studied over the last decade [13][14][15][16]. In theory, the process works with a wide range of noble metals. The main focus in research has been set on the noble metals gold (Au) and silver (Ag) [2][17][18][19]. Other studies

• The fabrication of the wafer-level integrated nanostructure templates is divided into two main parts, i.e., the formation of the noble metal nanoparticles, and the subsequent silicon wet etching process. The subsidiary process steps are standard semiconductor processes and therefore not analysed and

Influence of the epitaxial composition on N-face GaN KOH etch kinetics determined by ICP-OES

• Markus Tautz,
• Maren T. Kuchenbrod,
• Joachim Hertkorn,
• Robert Weinberger,
• Martin Welzel,
• Arno Pfitzner and
• David Díaz Díaz

Beilstein J. Nanotechnol. 2020, 11, 41–50, doi:10.3762/bjnano.11.4

• , surface roughening is an integral part of flip-chip processing. The two approaches towards surface roughening are wet- and dry-chemical etching [11][12]. During wet etching, aqueous KOH and other alkaline or acidic solutions are commonly used to remove GaN from the N-polar surface in an anisotropic manner

The importance of design in nanoarchitectonics: multifractality in MACE silicon nanowires

• Stefania Carapezzi and
• Anna Cavallini

Beilstein J. Nanotechnol. 2019, 10, 2094–2102, doi:10.3762/bjnano.10.204

• in the industry. The top-down methods involve the use of both dry [9][10] and wet etching [11] to carve nanostructures from a substrate. Metal-assisted chemical etching (MACE) [12][13][14][15] has gained particular attention in this regard, because it is simple, of low cost and versatile. MACE is an

• anisotropic wet etching technique where the sculpting of the nanostructures is catalyzed by a discontinuous thin film of noble metal deposited on a substrate. The metal works as a local cathode where the reduction of oxidants occurs. The underneath semiconductor is the local anode where a charge-mediated

Fabrication of phase masks from amorphous carbon thin films for electron-beam shaping

• Lukas Grünewald,
• Dagmar Gerthsen and
• Simon Hettler

Beilstein J. Nanotechnol. 2019, 10, 1290–1302, doi:10.3762/bjnano.10.128

• ). Pyramid-shaped trenches are generated beneath the thin films by anisotropic wet-etching of Si in a heated KOH solution (KOH + H2O in a ratio of 2:3, 80 °C, Figure 1a,c). The lithography mask was designed such that a 3 × 3 array of square-shaped SixNy thin films was produced on a single wafer (Figure 1b,c

• is not to scale as the SixNy windows and the Si wafer have a thickness of 120 nm and 200 µm, respectively. SEM images of the (b) top and (c) bottom surface reveal the 3 × 3 array of SixNy membranes and the pyramid-shaped trenches caused by anisotropic wet-etching of Si. The fabrication steps to

Bidirectional biomimetic flow sensing with antiparallel and curved artificial hair sensors

• Claudio Abels,
• Antonio Qualtieri,
• Toni Lober,
• Alessandro Mariotti,
• Lily D. Chambers,
• Massimo De Vittorio,
• William M. Megill and
• Francesco Rizzi

Beilstein J. Nanotechnol. 2019, 10, 32–46, doi:10.3762/bjnano.10.4

• the cantilever beams (300 nm etching depth). Subsequently, anisotropic back side wet etching with a potassium hydroxide (KOH) 28% solution at 85 °C creates two cavities underneath the cantilever beams (400 μm etching depth). The SiO2 insulating layer acts as an etching barrier. Next, a hydrofluoric

• acid (HF) back side wet etching step removes the SiO2 layer (2 μm etching depth). By performing a last KOH top side wet etching, the exposed (U-shaped) silicon device layer around the cantilevers is removed (2 μm etching depth). Due to the residual stress in the material, the released SiN/Si bilayer

Performance analysis of rigorous coupled-wave analysis and its integration in a coupled modeling approach for optical simulation of complete heterojunction silicon solar cells

• Ziga Lokar,
• Benjamin Lipovsek,
• Marko Topic and
• Janez Krc

Beilstein J. Nanotechnol. 2018, 9, 2315–2329, doi:10.3762/bjnano.9.216

• textures that are commonly applied in HJ Si solar cells. The first one can be experimentally realized on the nanometer scale by UV nanoimprint lithography (NIL) in combination with dry and wet etching of the wafer [6]. The second, the random pyramid texture, is typically used as a microtexture in c-Si

• solar cells and can be obtained by wet etching with KOH [36]. In Figure 4 simulated top views and cross-sectional profiles of the two textures are presented, in this case applied to the front part of the analyzed solar cell. The corresponding front thin layers are indicated by different colors. In

The nanofluidic confinement apparatus: studying confinement-dependent nanoparticle behavior and diffusion

• Stefan Fringes,
• Felix Holzner and
• Armin W. Knoll

Beilstein J. Nanotechnol. 2018, 9, 301–310, doi:10.3762/bjnano.9.30

• photolithography. Third, the masking layer was removed by wet etching (TechniEtch ACI2, MicroChemicals and TechniStrip Cr01, MicroChemicals) of the unprotected areas, leaving behind a central metal-resist stack defining the position of the mesa. The area around the stack was etched for 75 s by concentrated

Review: Electrostatically actuated nanobeam-based nanoelectromechanical switches – materials solutions and operational conditions

• Liga Jasulaneca,
• Jelena Kosmaca,
• Raimonds Meija,
• Jana Andzane and
• Donats Erts

Beilstein J. Nanotechnol. 2018, 9, 271–300, doi:10.3762/bjnano.9.29

Patterning of supported gold monolayers via chemical lift-off lithography

• Liane S. Slaughter,
• Kevin M. Cheung,
• Sami Kaappa,
• Huan H. Cao,
• Qing Yang,
• Thomas D. Young,
• Andrew C. Serino,
• Sami Malola,
• Jana M. Olson,
• Stephan Link,
• Hannu Häkkinen,
• Anne M. Andrews and
• Paul S. Weiss

Beilstein J. Nanotechnol. 2017, 8, 2648–2661, doi:10.3762/bjnano.8.265

• patterned Au substrates prior to lift-off (e.g., selective wet etching), or by patterning alkanethiols on Au substrates to be reactive in selected regions but not others (controlled reactivity). In all cases, the regions containing Au–alkanethiolate layers have a sub-nanometer apparent height, which was

• first round of CLL. Here, topographically patterned PDMS stamps were used to lift-off hydroxyl-terminated self-assembled alkanethiols (Figure S1, Supporting Information File 1) [1][9]. Following this CLL step, Au in the lifted-off (exposed) regions was removed by wet etching to form Au features in the

Fabrication of gold-coated PDMS surfaces with arrayed triangular micro/nanopyramids for use as SERS substrates

• Jingran Zhang,
• Yongda Yan,
• Peng Miao and
• Jianxiong Cai

Beilstein J. Nanotechnol. 2017, 8, 2271–2282, doi:10.3762/bjnano.8.227

• ] were also produced by a lithography-based method and reproducible plastic substrates were machined using different nanoimprinting methods [26]. For example, Courvoisier et al. [4] designed and fabricated an accurate inverted array of squares as a template on a silicon wafer via EBL and wet etching

Angstrom-scale flatness using selective nanoscale etching

• Takashi Yatsui,
• Hiroshi Saito and
• Katsuyuki Nobusada

Beilstein J. Nanotechnol. 2017, 8, 2181–2185, doi:10.3762/bjnano.8.217

• ; optical near-field; wet etching; Introduction The use of optical near-fields (ONFs) has contributed to the progress of nanoscale optical measurements [1], nanoscale fabrication [2], and photonic devices [3] below the diffraction limit of light. Recent ONF studies have exploited non-uniformity to realize

• organic materials [10]. Atomically flat surfaces both on the flat regions and on three-dimensional structures has been achieved. In this study, we compared near-field etching using a solution (wet etching) as well as dry etching. To evaluate the ONF effect with respect to wet or dry etching, we examined

• the etching characteristics using a two-dimensional Fourier analysis. Experimental Nanoscale etching For dry etching, we used Cl2 gas at a pressure of 200 Pa. 25 wt % calcium hypochlorous acid (Ca(ClO)2) was used as the source ion for wet etching. To dissociate the Cl2 or hypochlorous acid, we used a