Area-selective aerosol jet fog deposition: Advancing large-area and sustainable fabrication

In this work, we demonstrate controlled area-selective deposition of aluminum oxide phosphate (AlPO) at room temperature and near atmospheric pressure using a potentially zero-waste aerosol jet fog (ajFOG) deposition system. Octyl-trichlorosilane (OTS-8) self-assembled monolayers (SAMs) are coated on SiO2/Si substrates to form a blanket hydrophobic functionalization. Next, ultraviolet/ozone exposure through a shadow mask removes OTS-8 in the exposed regions, creating a pattern of hydrophobic and hydrophilic regions. AlPO is selectively deposited onto the hydrophilic regions from an aqueous aerosol precursor fog of aluminum phosphate inorganic clusters. Smooth films with sharp boundaries are deposited. The AlPO features and defects in the hydrophobic areas are investigated as a function of feature size, SAM type/application method/exposure time, ajFOG process parameters, and underlying substrate.