Damage-Free Cleaning of 2D van der Waals Heterostructures with Nano-Spherical AFM Probes

Two-dimensional materials have exceptional properties and gained significant attention from researchers. However, the fabricating process can introduce impurities that impact devices performance. Mechanical removal of interlayer impurities with AFM probe contact mode is a promising solution that avoids chemical impurities. However, sharp pyramidal probes used in this process can scratch fragile 2D material surfaces. To address this issue, our research team used nano-spherical probes to remove interlayer bubbles and contaminants in MoS
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heterostructures and improve surface quality. Results showed that nano-spherical probes were more effective than pyramid probes. In addition, nano-spherical probes also can improve material quality and surface consistency. Therefore, nano-spherical probes has promising potential to address the problem of cleaning interlayer bubbles and trapped contaminants and enhance the performance of heterostructure devices.