A hard mask process and alignment device aims to achieve high consistency and mass-scale production of gas sensors based on spraying hydrothermal gas sensing material

Abstract

The material synthesized through the hydrothermal method has received extensive and in-depth study in recent years, with a large number of literature reporting their excellent performance in the fields of catalysis or gas sensitivity. In order to combine the hydrothermal material with micro-electro-mechanical system processes to achieve large-scale manufacturing of hydrothermal synthesized materials at the wafer-level, this paper proposes a series of processes for hard mask patterned electro-atomization spraying of hydrothermal materials and designs and manufactures an alignment device that achieves the alignment of silicon hard mask and electrode wafers based on the vacuum clamping principle. Through experiments, it has been verified that this device can achieve micrometer-level alignment between the hard mask and the electrode wafer. By conducting electro-atomization spraying, hard mask patterning, optical microscopy, and confocal laser scanning microscope measurements, as well as gas sensitivity testing on a CeO2/TiO2 hydrothermal composite material published in our previous research, it was further verified that this process has good film formation consistency (Sa and Sq are both less than 3 μm and the average film thickness deviation is less than 5 μm), excellent and consistent gas sensitivity performance, and good long-term working stability. This article provides a promising process method for the large-scale production of hydrothermal synthesis materials at the wafer-level.