Shape-Controlled, Single-Crystal Gold Surface Nanostructures

10.26434/chemrxiv.9956450 ◽

2019 ◽

Author(s):

Sasan V. Grayli ◽

Xin Zhang ◽

Dmitry Star ◽

Gary Leach

Keyword(s):

Single Crystal ◽

Electroless Deposition ◽

Near Field ◽

Critical Role ◽

Deposition Process ◽

Local Fields ◽

Metal Nanostructures ◽

Large Area ◽

Device Applications ◽

Shape Controlled

Size, shape and crystallinity play a critical role in the wavelength-dependent optical responses and plasmonic local near-field distributions of metallic nanostructures. While their enhanced local fields can drive new and useful chemical and physical processes, the ability to fabricate shape-controlled single-crystal metal nanostructures and position them precisely on substrates for device applications represents a significant barrier to harnessing their greater potential. Here, we describe a novel electroless deposition process in the presence of anionic additives that yields additive-specific, shape-controlled, single-crystal plasmonic Au nanostructures on Ag(100) and Au(100) substrates. Deposition of Au in the presence of SO42- ions results in the formation of smooth Au(111)-faceted square pyramids that show large surface enhanced Raman responses. The use of halide additives such as Cl- and Br- that interact strongly with (100) facets produces highly textured hillock-type structures characterized by edge and screw-type dislocations (Cl-), or flat platelet-like features characterized by large area Au(100) terraces with (110) step edges (Br-). Use of additive combinations provides structures that comprise characteristics derived from each additive including new square pyramidal structures with dominant Au(110) facets (SO42-and Br-). Finally we demonstrate that this bottom-up electroless deposition process, when combined with top-down lithographic patterning methods, can be used to position shape-controlled, single-crystal Au nanostructures with precise location and orientation on surfaces. We anticipate that this approach will be employed as a powerful new tool to tune the plasmonic characteristics of nanostructures and facilitate their broader integration into device applications.

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Power Feeding in Large Area PECVD of Amorphous Silicon

MRS Proceedings ◽

10.1557/proc-377-27 ◽

1995 ◽

Vol 377 ◽

Cited By ~ 26

Author(s):

J. Kuske ◽

U. Stephan ◽

O. Steinke ◽

S. Röhlecke

Keyword(s):

Amorphous Silicon ◽

Silicon Layer ◽

Deposition Process ◽

Small Scale ◽

Voltage Distribution ◽

Large Area ◽

Electrode Area ◽

Electrical Devices ◽

Device Applications ◽

Design Power

ABSTRACTPlasma processes are usually worked out in a small-scale environment (electrode area maximum 121 cm2, rf- and VHF- excitation frequencies). In order to meet the requirements of large area device applications they have to be upscaled. The investigations of glow discharge systems for different PECVD reactors (parallel plate- and coaxial electrodes) have shown, that the reactor design (power supply, line connection) sharply influences the large area deposition process. The voltage distribution on the driven electrode especially determines the uniformity of the deposited layer thickness. Possibilities which influence the voltage distribution on large areas will be discussed. The results of large area electrode description as an electrical line will be discussed in comparison with different reactor configurations and the optimization of the behavior of the deposition process. The experimental results of a coaxial reactor (electrode area 5000 cm2, substrate length 120 cm) show that a homogenous deposition of amorphous silicon (layer uniformity of thickness over the length better ± 7 %) by connecting the driven electrode with additional electrical devices is possible.

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Development of Epitaxial, Tiling, and Cutting Processes for a Diamond Single Crystal Wafer Technology

MRS Proceedings ◽

10.1557/proc-416-45 ◽

1995 ◽

Vol 416 ◽

Cited By ~ 1

Author(s):

J. B. Posthill ◽

D. P. Malta ◽

T. P. Humphreys ◽

G. C. Hudson ◽

R. E. Thomas ◽

...

Keyword(s):

Single Crystal ◽

Electrochemical Etching ◽

Deposition Process ◽

Diamond Growth ◽

Diamond Single Crystal ◽

Large Area ◽

Free Standing ◽

Specific Sequence ◽

Single Crystal Diamond ◽

Close Proximity

ABSTRACTDevelopment of a diamond homoepitaxial deposition process that utilizes water and-ethanol at a growth temperature of ∼600°C is described. Topographies are excellent, and etch-pit densities (EPD) are in the 106 cm-2 range when growth is done on type Ia C(100) substrates.-This process has been used to epitaxially join diamond single crystals that were bonded in close-proximity to each other. This process of “tiling” single crystal diamonds in close proximity in-order to manufacture a large-area diamond single crystal template is also described. Specially-prepared diamonds that have had their faces and edges oriented to { 100} were coated with-heteroepitaxial Ni, then pressed onto a Si wafer while being heated in an inert gas atmosphere.-The resulting bond is excellent; thereby permitting our 600°C diamond deposition process to-epitaxially join the diamonds. A diamond wafer cutting technology has been addressed using a-specific sequence consisting of: ion implantation, homoepitaxial diamond growth, annealing, and-contactless electrochemical etching. This “lift-off” method of cutting has thus far resulted in a 2mm×O.5mm×17.5μm transparent, synthetic, free-standing, single crystal diamond plate being-fabricated. Raman spectroscopy and EPD show the plate to be comparable to our best-homoepitaxial diamond.

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High-Performance, Single-Crystal Gold Bowtie Nano-Antennas via Epitaxial Electroless Deposition

10.33774/chemrxiv-2021-lj2bz ◽

2021 ◽

Author(s):

Sasan V. Grayli ◽

Saeid Kamal ◽

Gary Leach

Keyword(s):

Single Crystal ◽

Noble Metal ◽

Optical Sensors ◽

Physical Vapor Deposition ◽

High Performance ◽

Electroless Deposition ◽

Mechanical Stability ◽

Ion Beam ◽

Critical Role ◽

Nano Antennas

Material quality can play a critical role in the performance of nanometer-scale plasmonic structures. Here, we highlight a novel deposition strategy for single-crystal noble metal deposition and provide a direct and quantitative comparison between the fabrication yield, durability, and efficiency of bowtie nano-antennas fabricated from monocrystalline and polycrystalline gold films using subtractive nanofabrication. Focused ion beam milling of monocrystalline Au(100) films deposited through epitaxial electroless deposition to form bowtie nano-antennas produces devices that demonstrate key performance enhancements over devices patterned identically from polycrystalline Au films deposited via physical vapor deposition. Single-crystal bowties reveal significant improvements in pattern transfer fidelity and device yield, the ability to tailor and model local plasmonic field enhancements and marked improvement in their thermal and mechanical stability over those fabricated from polycrystalline Au films. This work underscores the performance advantages of single-crystal nanoscale plasmonic materials and describes a straightforward, solution-phase deposition pathway to achieve them. We anticipate that this approach will be broadly useful in applications where local near-fields can enhance light−matter interactions, including for the fabrication of optical sensors, photocatalytic structures, hot carrier-based devices, and nanostructured noble metal architectures targeting nano-attophysics.

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Formation of Surface-Wrinkled Metal Nanosheets via Thermally Assisted Nanotransfer Printing

Korean Journal of Metals and Materials ◽

10.3365/kjmm.2021.59.12.880 ◽

2021 ◽

Vol 59 (12) ◽

pp. 880-885

Author(s):

Tae Wan Park ◽

Woon Ik Park

Keyword(s):

High Performance ◽

Low Cost ◽

High Surface ◽

High Surface Area ◽

Three Dimensional ◽

Deposition Process ◽

Large Area ◽

Wavy Structure ◽

Generate Surface ◽

Device Applications

Nanopatterning methods for pattern formation of high-resolution nanostructures are essential for the fabrication of various electronic devices, including wearable displays, high-performance semiconductor devices, and smart biosensor systems. Among advanced nanopatterning methods, nanotransfer printing (nTP) has attracted considerable attention due to its process simplicity, low cost, and great pattern resolution. However, to diversify the pattern geometries for wide device applications, more effective and useful nTP based patterning methods must be developed. Here, we introduce a facile and practical nanofabrication method to obtain various three-dimensional (3D) ultra-thin metallic films via thermally assisted nTP (T-nTP). We show how to generate surface-wrinkled 3D nanostructures, such as angular line, concave-valley, and convex-hill structures. We also demonstrate the principle for effectively forming 3D nanosheets by T-nTP, using Si master molds with a low aspect ratio (A/R ≤ 1). In addition, we explain how to obtain a 3D wavy structure when using a mold with high A/R (≥ 3), based on the isotropic deposition process. We also produced a highly ordered 3D Au nanosheet on flexible PET over a large area (> 15 µm). We expect that this T-nTP approach using various Si mold shapes will be applied for the useful fabrication of various metal/oxide nanostructured devices with high surface area.

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Observations on the growth of barium bismuth oxide thin films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100120783 ◽

1992 ◽

Vol 50 (1) ◽

pp. 76-77

Author(s):

M G. Norton ◽

E.S. Hellman ◽

E.H. Hartford ◽

C.B. Carter

Keyword(s):

Substrate Temperature ◽

Deposition Process ◽

Nucleation Layer ◽

Second Stage ◽

Device Applications ◽

High Transition ◽

Substrate Temperatures ◽

Oriented Material ◽

Barium Bismuth ◽

Superconductor Device

The bismuthates (for example, Ba1-xKxBiO3) represent a class of high transition temperature superconductors. The lack of anisotropy and the long coherence length of the bismuthates makes them technologically interesting for superconductor device applications. To obtain (100) oriented Ba1-xKxBiO3 films on (100) oriented MgO, a two-stage deposition process is utilized. In the first stage the films are nucleated at higher substrate temperatures, without the potassium. This process appears to facilitate the formation of the perovskite (100) orientation on (100) MgO. This nucleation layer is typically between 10 and 50 nm thick. In the second stage, the substrate temperature is reduced and the Ba1-xKxBiO3 is grown. Continued growth of (100) oriented material is possible at the lower substrate temperature.

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Computer simulation study about the dependence of amorphous silicon photonic waveguides efficiency on the material quality

The European Physical Journal Applied Physics ◽

10.1051/epjap/2020190250 ◽

2020 ◽

Vol 90 (3) ◽

pp. 30502

Author(s):

Alessandro Fantoni ◽

João Costa ◽

Paulo Lourenço ◽

Manuela Vieira

Keyword(s):

Amorphous Silicon ◽

High Throughput Screening ◽

Simulation Analysis ◽

Low Cost ◽

Deposition Process ◽

Large Area ◽

Sidewall Roughness ◽

Sensing Applications ◽

Fabrication Defects ◽

The Impact

Amorphous silicon PECVD photonic integrated devices are promising candidates for low cost sensing applications. This manuscript reports a simulation analysis about the impact on the overall efficiency caused by the lithography imperfections in the deposition process. The tolerance to the fabrication defects of a photonic sensor based on surface plasmonic resonance is analysed. The simulations are performed with FDTD and BPM algorithms. The device is a plasmonic interferometer composed by an a-Si:H waveguide covered by a thin gold layer. The sensing analysis is performed by equally splitting the input light into two arms, allowing the sensor to be calibrated by its reference arm. Two different 1 × 2 power splitter configurations are presented: a directional coupler and a multimode interference splitter. The waveguide sidewall roughness is considered as the major negative effect caused by deposition imperfections. The simulation results show that plasmonic effects can be excited in the interferometric waveguide structure, allowing a sensing device with enough sensitivity to support the functioning of a bio sensor for high throughput screening. In addition, the good tolerance to the waveguide wall roughness, points out the PECVD deposition technique as reliable method for the overall sensor system to be produced in a low-cost system. The large area deposition of photonics structures, allowed by the PECVD method, can be explored to design a multiplexed system for analysis of multiple biomarkers to further increase the tolerance to fabrication defects.

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