MEMS semiconductor type gas sensor based on glass substrate and manufacturing method of MEMS semiconductor type gas sensor

Abstract

The invention discloses an MEMS semiconductor type gas sensor based on a glass substrate and a manufacturing method of the MEMS semiconductor type gas sensor. The MEMS semiconductor type gas sensor comprises a sensitivity testing structure and a packaging structure, wherein the packaging structure comprises a ventilation cover plate, wherein the ventilation cover plate and the sensitivity testingstructure are combined in a sealed mode to form a gas cavity; the sensitivity testing structure comprises a glass substrate, a heating layer, an insulating layer and a gas sensitive material layer; the heating layer, the insulating layer and the gas sensitive material layer are sequentially arranged on the first surface of the glass substrate in a stacked mode; and the gas sensitive material layeris further electrically connected with a testing layer arranged on the insulating layer. According to the MEMS semiconductor type gas sensor based on the glass substrate provided by the embodiment ofthe invention, the processing technology is simple and reliable, and the whole sensor has good thermal insulation performance; and the sensor has a firmer structure, so that the sensor can be used inan impacted and vibrated environment.

Description

Technical field [0001] The invention relates to a gas sensor, in particular to a MEMS semiconductor gas sensor based on a glass substrate and a manufacturing method thereof, and belongs to the technical field of electronic devices. Background technique [0002] Gas sensors are widely used in the detection of flammable gases, toxic gases and atmospheric components. The micro-hot plate gas sensor based on MEMS technology has become the current research hotspot in the field of gas sensors due to its low power consumption, small size and easy integration. Most of the MEMS gas sensors use platinum as the heating wire, and use the back body silicon processing technology to realize the suspension of the micro hot plate. [0003] The structure of commonly used MEMS gas sensors is as Figure 1a , Figure 1b As shown, it is mainly based on a silicon substrate. An insulating layer, a heating layer, and a test layer are formed on the silicon substrate. The structure is relatively complicated. T...

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Problems solved by technology

[0003] The structure of the commonly used MEMS gas sensor is as follows: Figure 1a , Figure 1b As shown, it is mainly based on a silicon substrate, and an insulating layer, a heating layer, and a test layer are formed on the silicon substrate, and the structure is relatively complicated. Layer deposition, pad preparation and multiple photolithography and other process technologies; in order to improve heating efficiency, a cantilever beam heating structure is usually used. However, the current silicon-based MEMS gas sensors still have low yield, poor performance, and easy damage to the device. Disadvantages such as

[0004] In order to solve the problems existing in the above-mentioned MEMS gas sensor: the existing silicon-based MEMS gas sensor is mainly combined with the MEMS micromachining process, and uses the thin film deposition process to prepare the deposition of the insulating layer, the barrier layer and the seed layer, and then deposits the metal heating layer and the test layer respectively. Layer, and the main structure of the sensor is formed by wet or dry etching process, and then the sensitive material is deposited by sputtering, spraying, printing, etc., and the overall structure of the MEMS gas sensor is completed after the aging test; however, This kind of MEMS gas sensor has the following problems: on the one hand, depositing multi-layer films on silicon-based materials, especially the multi-layer composite of metal films and films such as silicon oxide and silicon nitride, can easily form high stress and cause device failure; The second is that the current MEMS gas sensor needs to work at a certain temperature. The superposition of multiple materials can easily cause the thermal expansion coefficient mismatch between the materials and cause damage to the device; the third is to print the sensitive sensor after etching the back cavity. The material will also cause damage to the suspended structure

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