Wafer-Level Self-Assembly and Interface Passivation Patterning Technology for Nanomaterial-Compatible 3D MEMS Sensing Chips

Wafer-scale fabrication of high-performance micro-electro-mechanical systems (MEMS) bio/chemical sensing chips remains constrained by the absence of reliable methods for integrating high-performance nanomaterials into suspended MEMS architectures. Here, a wafer-level manufacturing strategy is presented that redefines the MEMS process flow as "film first, cantilever later." Through kinetically controlled self-assembly, wet-chemically synthesized Pd/SnO₂ nanospheres are transferred as dense, uniform monolithic films onto 8-inch wafers. An HfO₂ interface passivation patterning technology resolves long-standing incompatibility between functional sensing films and silicon substrates, enabling precise patterning and reliable integration on suspended MEMS cantilevers. The resulting Pd/SnO₂ MEMS H₂ chips are fabricated onto an 8-inch wafer, demonstrating high sensitivity and consistency. This approach overcomes long-standing wafer-level manufacturing challenges in the formation and patterning of high-performance nanomaterials film, establishing a fully integrated wafer-level process that fundamentally redefines the manufacturing route for tetramethylammonium hydroxide-resistant nanomaterial-based MEMS sensing chips.