MEMS temperature, humidity and pressure three-in-one sensor chip and manufacturing process thereof

Abstract

The invention provides an MEMS temperature, humidity and pressure three-in-one sensor chip and a manufacturing process thereof, the MEMS temperature, humidity and pressure three-in-one sensor chip comprises an SOI wafer, the SOI wafer comprises a bulk silicon layer, a buried oxide layer and a device silicon layer, a layer of metal film grows on the SOI wafer, a temperature measuring resistor and a pressure measuring resistor are constructed on the metal film through patterning, and the temperature measuring resistor and the pressure measuring resistor are arranged on the SOI wafer. A SiO2 layer is further deposited outside the metal thin film to serve as a temperature compensation layer and an inner layer medium, the SiO2 layer is patterned to form a through hole, a conductive metal layer is deposited on the SiO2 layer, and the conductive metal layer is patterned to form a metal bonding pad and a metal connecting wire, so that the piezoresistor is connected into a Wheatstone bridge; an interdigital structure for humidity measurement is also patterned on the conductive metal layer; and a cavity structure is etched on the back of the SOI wafer substrate. The problems that an existing sensor is not beneficial to overall size control of an intelligent product in part of scenes and lacks a convenient design of a composite temperature, humidity and pressure measurement function, and part of the design with the composite measurement function cannot effectively reduce parasitic capacitance and the like are solved. Belongs to the technical field of sensors.

Description

technical field [0001] The invention relates to a MEMS temperature-humidity-pressure three-in-one sensor chip and a manufacturing process thereof, belonging to the technical field of sensors. Background technique [0002] Pressure sensors, temperature sensors, and humidity sensors are used more and more in industrial agriculture, but the packaging applicability of these sensors is currently poor. First of all, the size of these sensors is too large, which is not conducive to the overall size control of smart products in some scenarios; secondly, there is a lack of convenient design for composite temperature, humidity and pressure measurement functions; finally, some designs with composite measurement functions cannot effectively reduce parasitic capacitance, resulting in Device performance degrades. Contents of the invention [0003] The purpose of the present invention is to provide a MEMS temperature, humidity and pressure three-in-one sensor chip and its manufacturing ...

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Problems solved by technology

[0003] The purpose of the present invention is to provide a MEMS temperature, humidity and pressure three-in-one sensor chip and its manufacturing process to solve the problem that the size of the existing sensor is too large, which is not conducive to the overall size control of smart products in some scenarios, and lacks composite temperature, humidity and pressure measurement. The convenient design of functions, and some designs with composite measurement functions cannot effectively reduce parasitic capacitance, leading to problems such as device performance degradation

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