Fabrication of Homogeneous Nanoporous Structure on 4H‐/6H‐SiC Wafer Surface via Efficient and Eco‐Friendly Electrolytic Plasma‐Assisted Chemical Etching

Abstract

bio-compatibility, and high resistance to mechanical damage and chemical attack. [1,2] The combination of exceptional intrinsic properties with a high specific surface area and low dimensionality (in the case of SiC membranes) make nanoporous SiC excellent candidates for application in optoelectronic nanodevices. Many studies have reported that nanoporous structures can improve the material's optical, [3] electronic, and oxidation properties. [4,5] Various possible application scenarios for nanoporous structures have been reported in fields like microelectromechanical systems (MEMS), [6] membranes for biomedical applications, [7] chemical sensors, [8] supercapacitors, [9] and photoelectrodes. [10] In recent years, there have been extensive studies on constructing nanostructure SiC, employing robust and efficient techniques with improved controllability. However, the nanostructuring of SiC is very challenging owing to its extremely high chemical inertness and mechanical resistance. Although various fabrication methods have been developed, SiC nanofabrication techniques, which must meet the strict requirements of scalability and efficiency for industrial applications, remain very limited.The nanofabrication techniques for SiC can be broadly classified into two principal approaches, that is, top-down and bottom-up. The most explored bottom-up nanofabrication approach is a direct chemical synthesis for the growth of low-dimension SiC (i.e., 1D or 2D), such as chemical vapor deposition for the growth of SiC nanowires. [11] However, to produce nanostructure SiC from a single crystal wafer, for example, nanoporous SiC, the top-down fabrication approach by nanoscale etching is more effective and robust. Compared with the bottom-up approach, the top-down principle enables a well-ordered nanostructure with high homogeneity. Primary top-down nanofabrication methods include nanolithography using high-energy particles (i.e., photon, ion, electron), [12] dry etching, [13] and wet etching, [14] resulting in high-quality nanostructures for application in electronic devices or MEMS. The semiconductor lithography technique using UV or electron beam is mainly used for high-resolution nanostructure Nanoporous single-crystal silicon carbide (SiC) is widely used in various applications such as protein dialysis, as a catalyst support, and in photoanodes for photoelectrochemical water splitting. However, the fabrication of nano-structured SiC is challenging owing to its extreme chemical and mechanical stability. This study demonstrates a highly-efficient, open-circuit electrolytic plasma-assisted chemical etching (EPACE) method without aggressive fluorine-containing reactants. The EPACE method enables the nano-structuring of SiC via a plasma-enveloped microtool traversing over the target material in an electrolyte bath. Through process design, EPACE readily produces a uniform nanoporous layer on a 4H-SiC wafer in KOH aqueous solution, with adjustable pore diameters in the range 40-130 nm. Plasma diagnosis by optical emission spectrometr...

Phosphorus-Based Nanomaterials for Biomedical Applications: A Review

“…Plasma etching, a dry etching technique that utilizes plasma, offers a rapid approach to the fabrication of phosphorus-based nanomaterials through a “top-down” process (Figure e). The etching time can be manipulated to regulate the thickness of pure phosphorus crystals and uphold their high crystallinity. − Plasma etching results in the production of phosphorus-based nanomaterials characterized by high homogeneity. However, this process necessitates extreme synthesis conditions, incurs high costs, and requires sophisticated equipment. , …”

Development of plasma technology for the preparation and modification of energy storage materials

“…Etching is also an important application of plasma technology, which can clean or remove some components from the substrate surface. [51][52][53][54][55][56] The charged or excited particles exhibit high chemical activity and can react with some components of the material surface to form volatile products for removal, achieving the desired etching effect. Compared to traditional wetchemical etching with special reference to corrosive acids or bases, the plasma etching is the most attractive method that can be performed under liquid-free conditions, and relies solely on the reaction between the plasma gas source and the target material, with high repeatability and controllability.…”

Mechanism and regulation strategy of plasma-assisted shaped tube electrochemical machining for micro-hole drilling

“…In recent years, the plasma-assisted electrochemical machining (PA-ECM) method based on micro-rod electrode has gradually emerged, which can realize the microstructure fabrication on metals [22,23] and semiconductor [24] materials surface. In this method, the plasma has the characteristics of simple induction and can signi cantly improve the electrochemical dissolution e ciency.…”