Enhancing the uniformity and stability of graphene-based devices via Si3N4 film-assisted patterning

Owing to its remarkable physical attributes and substantial potential for use in electronic devices, graphene has garnered significant interest. However, conventional photolithography involving photoresist masks often results in organic residues on the graphene surface. Moreover, exposed graphene is highly vulnerable to doping by environmental factors such as H₂O, O₂, and impurities, which can severely degrade device performance. In this paper, an innovative process is proposed to deposit a silicon nitride (Si₃N₄) film on the graphene surface for patterning, while retaining the film as a protective layer. Scanning electron microscopy (SEM), atomic force microscopy (AFM) and Raman spectroscopy tests show that the process effectively avoids photoresist residues and there is almost no damage to graphene compared to bare graphene. Electrical tests show that the Si₃N₄ film-assisted patterning process significantly improves the device resistance consistency (29.36 % reduction in standard deviation) and stability due to the isolation of external impurities. High-temperature electrical tests show that the resistance consistency and stability of graphene temperature sensors processed by the Si₃N₄ film-assisted patterning process are still outstanding at high temperatures. This study not only opens up a new path for the preparation of graphene electronic devices, but also provides a solid technical support for the realization of high-performance and high-stability graphene electronic devices.