Metal-oxide gas sensor based on MEMS (Micro-Electro-Mechanic System) and preparation technology thereof

Abstract

The invention discloses a metal-oxide gas sensor based on MEMS (Micro-Electro-Mechanic System) and a preparation technology thereof. The gas sensor is characterized by comprising an Si substrate, an insulating layer, two thin-film resistor heating elements, a rectangular micro array, a pair of sensitive electrodes and a metallic oxide three-dimensional multi-level nano-structure produced on the rectangular micro array, wherein partial Si at the lower part of the Si base is removed in an anisotropic manner through wet etching; at the front of the gas sensor, the heating elements and the sensitive electrodes are arranged in a central symmetry and spiral manner, the rectangular micro array is arranged in the center, and the heating elements, the sensitive electrodes and the rectangular micro array are positioned on the same layer; the heating elements can also serve as temperature detecting elements. According to the invention, the nano-structure synthetized by adopting a hydrothermal method can realize the bridge type electrical connection through the mutually crossed dendritic structures, and is finally connected with the sensitive electrodes; the arrangement manner of the rectangular micro array is changed, and nano-materials of different types are replaced, so that the metal-oxide nano gas sensor based on different measuring circuits and sensitive materials of different types can be processed.

Description

technical field [0001] The invention relates to a metal oxide gas sensor structure and a preparation method based on MEMS (Micro-Electro-Mechanic System) technology. Background technique [0002] For public safety and health, it is very important to efficiently detect industrial toxic gases, flammable and explosive gases, components in chemical weapons, and chemical components related to diseases. And the research and development of chemical sensors with high sensitivity, high selectivity, fast response rate, short recovery time, and long-term stable work (the so-called 4S indicators, Sensitivity, Selectivity, Speed, Stability) have always been researchers. the goal that is pursued. [0003] In 1952, Brattain and Bardeen first discovered the gas-sensing properties of semiconductor germanium (Ge), which was subsequently discovered by Seiyama in metal oxides. Since then, semiconductor gas sensors based on metal oxides have been developed. It should be pointed out that metal...

AI Technical Summary

Problems solved by technology

[0010] The technical problem to be solved by the present invention is to overcome the difficulties in picking up, transferring, regular arrangement, mechanical adhesion, electrical connection and process compatibility of the nanostructures described in the background technology, and to realize nanostructures with top-down processing paths using MEMS technology Precise positioning of metal oxides, using a simple and cheap hydrothermal method to achieve in-situ growth of three-dimensional multi-level nanostructures of metal oxides with a bottom-up processing path

Images