Precision Deep Reactive Ion Etching of Monocrystalline 4H-SiCOI for Bulk Acoustic Wave Resonators with Ultra-Low Dissipation

Hamelin, Benoit; Yang, Jeremy; Ayazi, Farrokh

doi:10.1149/1945-7111/abdcc6

Cited by 10 publications

(5 citation statements)

References 24 publications

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“…Most of the defects may happen in the mesa etching process. Here, some strategies have been proposed for suppressing nonradiative recombination to increase the EQE of μLEDs, including (i) thermal annealing to avoid sidewall defects, (ii) passivation layer deposition by either PECVD or ALD, (iii) chemical treatments to eliminate surface imperfections, and (iv) restricting the current spreading length to stay away surface defects. ,− …”

Section: Technological Challenges Of μLedsmentioning

confidence: 99%

Technology and Applications of Micro-LEDs: Their Characteristics, Fabrication, Advancement, and Challenges

Lee

Chen

et al. 2022

ACS Photonics

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Micro-light-emitting diodes (μLEDs) are getting much attention in display industry because of their outstanding optical and electrical characteristics. μLEDs have several advantages over liquid crystal displays (LCDs) and organic lightemitting diodes (OLEDs). μLEDs are showing long lifetimes, high reliability, high power efficiencies, high brightness, and fast response times with tiny pixels. However, for commercial usage, the high production cost and low external quantum efficiency (EQE) are the major hurdles. In this review, we briefly discuss the breakthroughs in μLED technology, fabrication methods, optical/ electrical characteristics, and challenges for display applications. In addition, the development of monolithic μLEDs and general device characteristics combined with various quantum dot patterning processes are systematically discussed. Potential solutions to address these challenges are also presented case by case.

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Section: Technological Challenges Of μLedsmentioning

confidence: 99%

Technology and Applications of Micro-LEDs: Their Characteristics, Fabrication, Advancement, and Challenges

Lee

Chen

et al. 2022

ACS Photonics

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“…Dry etching is a well-established, mature technology that has been widely used in the silicone industry for more than four decades [21]. Dry etching has, as a result, become one of the central processing steps in the fabrication of many SiC nanostructures on SiC wafers [22][23][24][25]. In the present work, vertically oriented SiC nanoarrays have been successfully synthesized under controlled pressure, etching gas ratio, and etching time in a commercially available reactive ion etching system.…”

Section: Introductionmentioning

confidence: 98%

Stable Field Emission from Vertically Oriented SiC Nanoarrays

et al. 2021

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Silicon carbide (SiC) nanostructure is a type of promising field emitter due to high breakdown field strength, high thermal conductivity, low electron affinity, and high electron mobility. However, the fabrication of the SiC nanotips array is difficult due to its chemical inertness. Here we report a simple, industry-familiar reactive ion etching to fabricate well-aligned, vertically orientated SiC nanoarrays on 4H-SiC wafers. The as-synthesized nanoarrays had tapered base angles >60°, and were vertically oriented with a high packing density >107 mm−2 and high-aspect ratios of approximately 35. As a result of its high geometry uniformity—5% length variation and 10% diameter variation, the field emitter array showed typical turn-on fields of 4.3 V μm−1 and a high field-enhancement factor of ~1260. The 8 h current emission stability displayed a mean current fluctuation of 1.9 ± 1%, revealing excellent current emission stability. The as-synthesized emitters demonstrate competitive emission performance that highlights their potential in a variety of vacuum electronics applications. This study provides a new route to realizing scalable field electron emitter production.

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“…Electropolishing is a non-contact electrochemical process that effectively removes burrs [ 19 ], asperities [ 20 ], and other impurities from metal surfaces [ 21 ]. Unlike other microfabrication techniques such as metal-assisted chemical etching [ 22 ], laser polishing [ 23 ], and deep reactive ion etching [ 24 ], electropolishing stands out because it removes material based on current density distribution [ 25 ], while other processes are limited by their anisotropic nature. As a result, electropolished metal surfaces become level and bright and have low surface roughness, while metals with micro features develop rounded edges, thinner features, and changes in draft angles.…”

Section: Introductionmentioning

confidence: 99%

Optimization of forward pulsed currents for combining the precision shaping and polishing of nickel micro mould tools to reduce demoulding defects

Zaki,

Zhang,

Gilchrist

2024

Int J Adv Manuf Technol

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Precise tooling is vital for defect-free production of micro injection moulded (μ-IM) or hot-embossed products. The demoulding stage of such moulding and forming processes poses a serious challenge to the integrity of thin miniature features because of friction, adhesion, and thermal stresses. Typically, micro moulds involve geometrically textured patterns or features such as linear ridges, pillars, channels, and holes, the characteristic dimensions of which range from 10 to 300 μm. Realistically complex mould designs, containing precision micro features (enhanced fillet radius and positive draft angle) and high surface quality, are presented in this work. Electropolishing based on forward pulse currents (PC) has been used to shape and polish Ni micro moulds that contain sets of micron-scaled linear ridges and star patterns in order to ease the separation of moulded polymeric parts from the metallic mould during ejection and demoulding. The use of forward pulsed currents improved the mould design by increasing the fillet radii and draft angle while keeping the surface roughness low and maintaining a good surface shine. An optimization study of forward PC using a green solution of nickel sulfamate varied EP times (0–70 min) and duty cycles (40, 50, 60, and 70%) at a process conditions of 2.8 V, 50 °C, and 250 rpm. The best topographical and morphological changes were observed for a typical microfluidic channel (w × h, 100 × 110 μm) with an EP time of 70 min and 50% duty cycle: fillet radius increased by 3.8 μm, draft angle by 3.3°, and the channel width reduced by 11.4% while surface roughness changed by 8.6% and surface shine improved by 48.9%. Experimental validation was performed using hot embossing wherein the electropolished Ni mould replicated the micro channels and star patterns in PMMA chips with notably fewer burrs, material pile up, and no feature distortion. Moreover, there was a reduction in the side wall roughness of micro channels in PDMS casting with electropolished Ni mould by 16%. Hence, this work presents a significant scientific contribution to improving the efficiency of micro mould tools and reduces the defects caused by friction and adhesion in replicated polymeric parts.

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Precision Deep Reactive Ion Etching of Monocrystalline 4H-SiCOI for Bulk Acoustic Wave Resonators with Ultra-Low Dissipation

Cited by 10 publications

References 24 publications

Technology and Applications of Micro-LEDs: Their Characteristics, Fabrication, Advancement, and Challenges

Technology and Applications of Micro-LEDs: Their Characteristics, Fabrication, Advancement, and Challenges

Stable Field Emission from Vertically Oriented SiC Nanoarrays

Optimization of forward pulsed currents for combining the precision shaping and polishing of nickel micro mould tools to reduce demoulding defects

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