Nanofabrication Engineering For Molecule Sensing Beyond Single Solid-State Nanopore Measurements

Nanopore-based DNA sequencing provides several advantages over alternative conventional methods, e.g., single-molecule detection, long reading lengths, chemical label-free samples, reduced contamination during the sample preparation process. While protein nanopores sequencing has advanced into the stage of commercialization over the past few decades, solid-state nanopores still hold promises regarding high-throughput reading, high signal-to-noise (SNR) ratio detection, and long-term stability and operating lifetime under extreme environments.In this dissertation, we first qualitatively investigate the stability of silicon nitride (SiN) nanopores by storing devices in various electrolyte solutions and measuring open- pore conductance over a period of months. A series of corresponding pore diameter etch rates is reported. And we further utilize a conformal 1-nm-thick hafnium oxide (HfO2) layer to prolong the nanopore devices' lifetime effectively. Next, we demonstrate biomolecules translocations measurements with traditional single solid-state nanopore devices, using silicon nitride and tungsten disulfide (WS2) nanopores, respectively. To further explore possibilities beyond single nanopore sensors, we showcase an in-plane parallel two-pore device. We can analyze and categorize event detections from each nanopore using a conventional two-terminal measurements setup. This outcome can be achieved due to the high sensitivity in detection current signals regarding the nanopore geometry design, i.e., pore diameters and thicknesses. Additionally, we propose and demonstrate an advanced two-layer device. We combine the well-developed fabrication technique for SiN, and the optimized spatial resolution of a one-atomic-layer thin molybdenum disulfide (MoS2) nanopore. We introduce a guiding and reusable (GURU) platform, where we position a 2D monolayer above the silicon nitride (GURU) layer. Aiding with simulation results from COMSOL, we provide a detailed look into this coupled two- layer nanopore system.