Polymethyl Methacrylate (PMMA) Pyrolysis Assisted Transfer of 2D Materials for Large-Scale Molybdenum Disulfide Nems Resonator Arrays

We develop a novel fabrication technique for large-scale two-dimensional (2D) molybdenum disulfide (MoS
2
) nanoelectromechanical resonator arrays, based on polymethyl methacrylate (PMMA) pyrolysis. During the transfer process, centimeter-scale monolayer MoS
2
film grown by chemical vapor deposition (CVD) is covered with PMMA film by spin coating, delaminated from the growth substrate in water, and then transferred onto the pre-patterned substrate with surface microtrenches and contact electrodes. The PMMA is then removed by pyrolysis, or thermal decomposition in a furnace in vacuum, leaving behind the suspended array of resonant MoS
2
nanoelectromechanical systems (NEMS). We then experimentally demonstrate a consistent upward frequency tuning up to 160% and downward quality (Q) factor shift as DC gate voltage (V
GS
) increases. The measured resonance frequencies and Q factors among different devices show smaller variations compared with previous reports. The new transfer technique enables consistent and high-quality 2D NEMS resonator arrays, and paves the way towards scalable and low-cost production of 2D NEMS resonators for on-chip sensing, radio-frequency (RF) signal processing, and computing.