Thermomechanical Nanocutting of 2D Materials

Abstract

Atomically thin materials, such as graphene and transition metal dichalcogenides, are promising candidates for future applications in micro/nanodevices and systems. For most applications, functional nanostructures have to be patterned by lithography. Developing lithography techniques for 2D materials is essential for system integration and wafer‐scale manufacturing. Here, a thermomechanical indentation technique is demonstrated, which allows for the direct cutting of 2D materials using a heated scanning nanotip. Arbitrarily shaped cuts with a resolution of 20 nm are obtained in monolayer 2D materials, i.e., molybdenum ditelluride (MoTe2), molybdenum disulfide (MoS2), and molybdenum diselenide (MoSe2), by thermomechanically cleaving the chemical bonds and by rapid sublimation of the polymer layer underneath the 2D material layer. Several micro/nanoribbon structures are fabricated and electrically characterized to demonstrate the process for device fabrication. The proposed direct nanocutting technique allows for precisely tailoring nanostructures of 2D materials with foreseen applications in the fabrication of electronic and photonic nanodevices.

Scanning Probe Lithography: State-of-the-Art and Future Perspectives

“…The t-SPL and tc-SPL targets are used to machine a wide range of materials, such as molecular glass resist [75], biomaterials, organisms [76], 2D materials [77,78], metals, carbon nano-tubes [79], nanoparticles, and polymers, including supramolecular polymer [80], polycarbonate [69,81], polystyrene [82], block copolymers [83], and polyethylene [84]. Representative work of the t-SPL was carried out in the early 1990s, and it was first extended to the area for data storage purposes.…”

Universal Patterning for 2D Van der Waals Materials via Direct Optical Lithography

“…[12,13] Nano-mechanical patterning methods show low throughput and local scale due to their bottom-up nature. [14,15] The patterning method customized for vdW materials with large-scale, highthroughput, and high-resolution has yet to be reported.…”

“…The photo source in this work has a relatively high power density (5.29-58.19 MW cm −2 ) in short pulse (25 ns) compared to other photo sources. [12,14] The simulation was carried out in the system where light was blocked in the region covered by circular Al pattern with radius of 5 µm in the sapphire mask (remarked as the black-dotted line circle in Figure 6a) and light reached ML MoS 2 in the rest of regions. In the P 0 /20 case, it took 95 µs to reach the temperature, 1579 K, where ML MoS 2 was entirely etched in the P 0 case (Figure S13, Supporting Information).…”

Self-Triggered Thermomechanical Metamaterials with Asymmetric Structures for Programmable Response under Thermal Excitations

“…Studies have been conducted to investigate the material properties of thermomechanical materials. Experimental fabrication and characterization were carried out on the microstructures of the thermomechanical materials, e.g., cellular materials [ 26 ], 2D materials [ 27 ], and vacuum-infused thermoplastic- and thermoset-based composites [ 28 ]. Besides the experimental characterization, constitutive models have been developed to predict the thermomechanical response [ 29 , 30 ].…”