Impact of Lateral SnO<sub>2</sub> Nanofilm Channel Geometry on a 1024 Crossbar Chemical Sensor Array
Haruka Honda, Tsunaki Takahashi, Yohsuke Shiiki, Hao Zeng, Kentaro Nakamura, Shintaro Nagata, Takuro Hosomi, Wataru Tanaka, Guozhu Zhang, Masaki Kanai, Kazuki Nagashima, Hiroki Ishikuro, Takeshi Yanagida
Abstract
We propose a rational strategy to fabricate thermally robust, highly integrated molecular and gas sensors utilizing a lateral SnO2 nanofilm channel geometry on a 1024 crossbar sensor array. The proposed lateral channel geometry substantially suppresses the detrimental effects of parasitic interconnect wire resistances compared with those of a conventional vertical sandwich-type crossbar array because of its excellent resistance controllability. A conductive oxide top-contact electrode on the lateral SnO2 nanofilm channel enhances the thermal stability at temperatures of up to 500 °C in ambient air. Integrating this lateral SnO2 nanofilm geometry with analog circuits enables the operation of a 1024 crossbar sensor array without selector devices to avoid sneak currents. The developed 1024 crossbar sensor array system detects the local spatial distribution of the molecular gas concentration. The spatial data of molecular concentrations include molecule-specific data to distinguish various volatile molecules based on their vapor pressures. Thus, this integrated crossbar sensor array system using lateral nanofilm geometry offers a platform for robust, reliable, highly integrated molecular and gas sensors.