Infrared detector with multi-layer structure based on CMOS process

An infrared detector with a multi-layer structure based on a CMOS process, comprising:

• a CMOS measuring circuit system and a CMOS infrared sensing structure, wherein both the CMOS measuring circuit system and the CMOS infrared sensing structure are fabricated by using CMOS technology, and wherein the CMOS infrared sensing structure is directly fabricated on the CMOS measuring circuit system;
• the CMOS infrared sensing structure includes at least one sealed release isolation layer arranged above the CMOS measuring circuit system, wherein the sealed release isolation layer is configured to protect the CMOS measuring circuit system from process influence in a release etching course of manufacturing the CMOS infrared sensing structure;
• the CMOS infrared sensing structure comprises at least three metal interconnection layers, at least three dielectric layers and a plurality of interconnection through holes, wherein the metal interconnection layer comprises at least a reflecting layer and two electrode layers, and the dielectric layer comprises at least two sacrificial layers and a heat-sensitive dielectric layer;
• wherein the heat-sensitive dielectric layer is configured to convert a temperature change into a resistance change, and then convert an infrared target signal into an electrical signal which is electrically readable through the CMOS measuring circuit system, wherein the temperature change corresponds to infrared radiation absorbed by the heat-sensitive dielectric layer, the infrared target signal corresponds to the resistance change;
• wherein the CMOS infrared sensing structure comprises a resonant cavity and a suspended micro-bridge structure for controlling heat transfer, wherein the resonant cavity is composed of the reflecting layer and the heat-sensitive dielectric layer and the suspended micro-bridge structure comprises at least one layer of beam structure and at least one layer of absorption plate, the beam structure is located at one side of the absorption plate close to or away from the CMOS measuring circuit system, a first columnar structure is provided between the reflecting layer and the beam structure, and the first columnar structure is directly electrically connected to a support base in the reflecting layer and the beam structure, the beam structure is electrically connected to the CMOS measuring circuit system through the first columnar structure and the support base;
• a second columnar structure is provided between the absorption plate and the beam structure, and the second columnar structure is directly electrically connected to the absorption plate and the beam structure, and the absorption plate is configured to convert the infrared target signal into the electrical signal and electrically connect to the first columnar structure through the second columnar structure and the beam structure;
• wherein the first columnar structure comprises at least one layer of solid columnar structure and/or at least one layer of hollow columnar structure, and the second columnar structure comprises at least one or a layer of solid columnar structure or a layer of hollow columnar structure.