Optimization of nanofountain probe microfabrication enables large-scale nanopatterning

A technological gap in nanomanufacturing has prevented the translation of many nanomaterial discoveries into real-world commercialized products. Bridging this gap requires a paradigm shift in methods for fabricating nanoscale devices in a reliable and repeatable fashion. Here we present the optimized fabrication of a robust and scalable nanoscale delivery platform, the nanofountain probe (NFP), for parallel direct-write of functional materials. Microfabrication of a new generation of NFP was realized with the aim of increasing the uniformity of the device structure. Optimized probe geometry was integrated into the design and fabrication process by modifying the precursor mask dimensions and by using an isotropic selective dry etching of the outer shell that defines the protrusion area. Probes with well-conserved sharp tips and controlled protrusion lengths were obtained. Sealing effectiveness of the channels was optimized. A conformal tetraethyl orthosilicate based oxide layer increased the sealing efficacy while minimizing the required thickness. A compensation scheme based on the residual stresses in each layer was implemented to minimize bending of the cantilever after releasing the device. The device was tested by patterning ferritin catalyst arrays on silicon dioxide with sub-100 nm resolution. The optimized probes increased the control over the parallel patterning resolution which enables manufacturing of ordered arrays of nanomaterials.