Raster-Atomic Force Nanolithography: New Insights Towards the Fabrication of 3d Nanostructures on Pmma and Silicon Nitride

The rapid advancement of nanoscience has driven significant interest in manipulating materials at the nanoscale, a capability critical to diverse High-tech fields. Achievements in nanoscale analysis and nanofabrication have facilitated practical applications across a range of fields, including  nanoelectronics, nanofluidics, drug delivery, optical and plasmonic devices, and biosensing. However, traditional top-down fabrication techniques, such as Electron Beam Lithography, Focused Ion Beam lithography, Two-Photon Lithography, and Nanoimprint Lithography, are often limited by cost, scalability, and manufacturing complexity. Scanning Probe-based Lithography (SPL) has recently emerged as a promising alternative, offering precise nanostructure fabrication and immediate characterization in ambient conditions. This paper focuses on Raster-Atomic Force Microscopy (R-AFM) nanolithography, highlighting its capability for fabricating 3D nanostructures on Polymethyl methacrylate (PMMA) with minimal process steps. By coupling this technique with a simple wet etching process using Methyl Isobutyl Ketone (MIBK) and 2-propanol (IPA), we achieve enhanced resolution and nanostructure quality is achieved. Furthermore, the nanostructures are successfully transferred to a Silicon Nitride (SixNy) substrate via plasma etching, demonstrating the versatility of the approach. This combination of AFM-based lithography, wet etching, and plasma transfer represents an innovative and efficient method for creating nanopatterned surfaces on both soft and hard substrates, addressing key limitations of conventional nanofabrication techniques.