Session: 14-04-01: Micro/Nano Devices and Medical Systems

Paper Number: 164213

Sub-5 μM Patterning and Large-Area Transfer Technology for Two-Dimensional Materials 

Two-dimensional (2D) materials, with their atomic-scale thickness and unique structures, demonstrate broad application potential in electronics, optoelectronics, and energy fields. The advancement of microelectronic integrated devices critically depends on high-precision and low-cost fabrication of 2D material micro-patterns, as well as the transfer techniques onto arbitrary substrates. However, existing micro-patterning techniques struggle to simultaneously meet high-precision and low-cost requirements. Micro-patterns are typically transferred to target substrates using stamps, with the removal of intermediate stamps often causing damage to 2D materials.

Here, we propose a vacuum-assisted filtration method integrated with mask-guided patterning for 2D materials, and a capillary force-driven transfer technique without intermediate stamps, enabling the fabrication of micro-pattern arrays and their large-area damage-free transfer onto arbitrary substrates. During filtration, the filter membrane serves as the growth substrate, while the mask confines the flow of the 2D material dispersion, directing nanosheet deposition within predefined channels to form designed micro-patterns. After the fabrication of micro-patterns, the wet filter membrane with the 2D materials is adhered to the target substrate. To ensure conformal contact between the 2D material micro-patterns and the substrate, a shape-memory elastomer sphere is used to apply controlled pressure on the filter. After peeling off the filter membrane, the 2D materials pattern array is transferred to the target substrate because the capillary force between the semi-wet 2D materials and the target substrate interface is larger than that of the 2D material-filter interface. This process enables the transfer of centimeter-scale films of various 2D materials (Ti₃C₂T_x, Ti₂CT_x, and graphene oxide) as well as one-dimensional materials (carbon nanotubes). We also develop a theoretical model for the transfer process to investigate the interfacial interactions of 2D materials with both the filter and target substrate during the process.

We use Ti₃C₂T_x MXene as the representative material for our experiment. After transferring, significant reductions in both surface roughness (from 69.8 nm to 5.3 nm) and interlayer spacing (from 1.692 nm to 1.446 nm) are observed in transferred 500 nm-thick Ti₃C₂T_x MXene films. As a result, the electrical conductivity is enhanced from 0.187 S to 0.341 S. Hydrophilic treatment of the target substrate helps the successful transfer onto rigid substrates (glass, copper, silicon wafers) and flexible substrates (polyimide, polydimethylsiloxane, liquid crystal elastomer). For sub-10 µm micro-patterns, the lateral dimensions of 2D material flakes critically govern patterning fidelity. By controlling the size of the flakes using ultrasonic oscillation, high-quality printing of patterns below 4 µm can be achieved. The process ultimately enables the fabrication and transfer of line arrays with a minimum width of 3.77 µm, as well as dot arrays with a diameter of 7 µm and a minimum spacing of 2.56 µm.

In addition, the successful transfer of chemical vapor deposition (CVD)-grown monolayer graphene onto Ti₃C₂T_x electrodes fabricated via our process, and its demonstration as a functional microelectronic device, highlights the application potential of this methodology.

Presenting Author: Han Yu Zhejiang University

Presenting Author Biography: I am currently a Ph.D. candidate at the College of Mechanical Engineering, Zhejiang University, under the supervision of Professors Yang Li and Deqing Mei. My primary research focuses on the fabrication of micro-nano patterns of two-dimensional materials and their transfer onto various substrates. I am passionate about exploring innovative techniques to enhance the performance and applicability of two-dimensional materials in advanced engineering applications.

Authors:

Han Yu Zhejiang University
Yang Li Zhejiang University
Deqing Mei Zhejiang Unversity