Fabrication of Au gratings by seedless electroplating for X-ray grating interferometry

Kagias, Matias; Wang, Zhentian; Guzenko, Vitaliy A.; Dávid, Christian; Stampanoni, Marco; Jefimovs, Konstantins

doi:10.1016/j.mssp.2018.04.015

Cited by 37 publications

(50 citation statements)

References 27 publications

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“…In the following section, we address the fabrication of Si templates that can be used directly as phase modulating gratings or be subsequently filled with high X-ray absorbing materials, such as Ir 70 or Au, 71 and used as analyser gratings. Patterned metal layers were produced by following the schematic procedure of Fig.…”

Section: Patterned Structures For X-ray Opticsmentioning

confidence: 99%

“…The pattern was produced by using e-beam lithography in the case of nanostructures and a conventional UV lithography in the case of microstructures. The patterns of X-ray diffractive elements, consisting of linear 72 or circular gratings, 73 were optimized by introducing interconnects between the catalyst lines, which suppress the off-vertical catalyst movement during MacEtch. 29 In detail, bridges were added to a periodic pattern, and some examples of metal patterns before the etching are reported in the ESI † (Fig.…”

Section: Patterned Structures For X-ray Opticsmentioning

confidence: 99%

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Metal assisted chemical etching of silicon in the gas phase: a nanofabrication platform for X-ray optics

et al. 2020

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Section: Patterned Structures For X-ray Opticsmentioning

confidence: 99%

Section: Patterned Structures For X-ray Opticsmentioning

confidence: 99%

Metal assisted chemical etching of silicon in the gas phase: a nanofabrication platform for X-ray optics

et al. 2020

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“…The latter configuration allows using relatively small-area gratings (5 cm × 7 cm) to cover the required FOV ( Fig. 1), which is rather large (26 × 21 cm 2 ) to be spanned with a single grating, considering the corresponding engineering limitations [18]. The GI design parameters (Table 1) were optimized for the differential phase-contrast (DPC) signal following the procedure described in [17], but using a larger inter-grating distance to improve setup sensitivity, which could be achieved by modifying the pre-collimator height.…”

Section: Methodsmentioning

confidence: 99%

Towards clinical grating-interferometry mammography

et al. 2019

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Objectives Grating-interferometry-based mammography (GIM) might facilitate breast cancer detection, as several research works have demonstrated in a pre-clinical setting, since it is able to provide attenuation, differential phase contrast, and scattering images simultaneously. In order to translate this technique to the clinics, it has to be adapted to cover a large field-of-view within a clinically acceptable exposure time and radiation dose. Methods We set up a grating interferometer that fits into a standard mammography system and fulfilled the aforementioned conditions. Here, we present the first mastectomy images acquired with this experimental device. Results and conclusion Our system performs at a mean glandular dose of 1.6 mGy for a 5-cm-thick, 18%-dense breast, and a field-of-view of 26 × 21 cm2. It seems to be well-suited as basis for a clinical-environment device. Further, dark-field signals seem to support an improved lesion visualization. Evidently, the effective impact of such indications must be evaluated and quantified within the context of a proper reader study. Key Points • Grating-interferometry-based mammography (GIM) might facilitate breast cancer detection, since it is sensitive to refraction and scattering and thus provides additional tissue information. • The most straightforward way to do grating-interferometry in the clinics is to modify a standard mammography device. • In a first approximation, the doses given with this technique seem to be similar to those of conventional mammography.

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“…The presence of the metal catalyst layer at the bottom of the etched structures offers the possibility of using the same as a metallization contact for the subsequent Au electroplating step. With respect to other approaches of the damascene process, [36] the seed growth from the bottom [37,38] does not need any additional step of conformal metallization [39] and allows to create a compact Au filling [40] independently of aspect ratio. [41] The Pt catalyst was designed to have a full interconnected pattern that can be used as metallization for seed growth of Au by electroplating (Figure 1h).…”

Section: Seed Gold Electroplatingmentioning

confidence: 99%

“…[41] The Pt catalyst was designed to have a full interconnected pattern that can be used as metallization for seed growth of Au by electroplating (Figure 1h). The Si trenches were oxidized in air so that they became electrically isolated, [38] thus promoting the growth of Au from the bottom of the trench. As the Pt MacEtch grating has a thick conformal porous layer, the growth of native Si oxide (Figure 1g) is enough to avoid the Au growth on the side walls during electroplating.…”

Section: Seed Gold Electroplatingmentioning

confidence: 99%

High‐Aspect‐Ratio Grating Microfabrication by Platinum‐Assisted Chemical Etching and Gold Electroplating

et al. 2020

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Diffractive optics play a key role in hard X‐rays imaging for which many scientific, technological, and biomedical applications exist. Herein, high‐aspect‐ratio microfabrication of gratings for X‐ray interferometry is demonstrated using Pt as a catalyst for the metal assisted chemical etching of Si in a solution of HF and H2O2. The Pt layer is thermally treated to realize a porous catalyst layer that stabilizes the etching of a pattern with a pitch size from 4.8 to 20 μm in the direction perpendicular to the <100> Si substrate and an aspect ratio up to 60:1. The superior etching performance of Pt as a catalyst and its stability in a solution with high HF content are reported in direct comparison with the Au catalyst for the same grating parameters. The Si structure is then used as a template for filling with Au, as a high absorbing X‐ray material. The Pt catalyst layer is used as a conductive seed for Au electroplating. The quality of the overall process is assessed by obtaining a visibility map using 30 μm‐thick Au grating in an X‐ray interferometric setup at 20 keV.

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Fabrication of Au gratings by seedless electroplating for X-ray grating interferometry

Cited by 37 publications

References 27 publications

Metal assisted chemical etching of silicon in the gas phase: a nanofabrication platform for X-ray optics

Metal assisted chemical etching of silicon in the gas phase: a nanofabrication platform for X-ray optics

Towards clinical grating-interferometry mammography

High‐Aspect‐Ratio Grating Microfabrication by Platinum‐Assisted Chemical Etching and Gold Electroplating

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