Optimization of TiN/TiO_xN_y Laminated Electrode Films for High-Performance Gene Sequencing Chip

Abstract With continuous advancement of the fourth generation nanopore gene sequencing technology, the requirements for performance of the electrode films in gene sequencing chips are increasing. This study utilized the high vacuum reactive magnetron sputtering method to examine the impact of working pressure on the electrical, electrochemical, crystal structure, chemical composition, and surface morphology of TiOxNy thin films in detail. The findings revealed that the TiN thin film deposited at 0.4 Pa exhibited the lowest resistivity of 391.9 μΩ·cm. Additionally, the TiOxNy thin film deposited at 1.6 Pa demonstrated the highest volumetric specific capacitance of 35.37 mF·cm-2·μm-1 at 5 mV·s-1. Utilizing the optimal parameters, TiN/TiOxNy laminated electrode thin films were in-situ grown. Through measurements and analysis, it was found that the TiN/TiOxNy electrode thin film effectively achieves a 29.35% improvement in specific capacitance compared to the single layer TiOxNy electrode thin film. The integration of a TiN current collector with low resistivity effectively reduced the internal resistance of the electrode system and decreased the response time to 0.038 s. The features of low impedance and high specific capacitance of TiN/TiOxNy laminated thin films offer promising prospects for the preparation of gene sequencing chip with high throughput.