CN112117362B

CN112117362B - Thermopile sensor, manufacturing method thereof and electronic device

Info

Publication number: CN112117362B
Application number: CN202010615301.0A
Authority: CN
Inventors: 黄河
Original assignee: Smic Ningbo Co ltd Shanghai Branch
Current assignee: Smic Ningbo Co ltd Shanghai Branch
Priority date: 2020-06-30
Filing date: 2020-06-30
Publication date: 2023-02-17
Anticipated expiration: 2040-06-30
Also published as: CN112117362A

Abstract

The invention provides a thermopile sensor, a manufacturing method thereof and electronic equipment, wherein the thermopile sensor comprises the following components which are sequentially arranged along the incident radiation direction: the thermal power generation device comprises a thermopile structure plate, a heat radiation induction area and a control unit, wherein the thermopile structure plate is provided with a thermal radiation induction area, and a thermopile structure is arranged in the thermal radiation induction area; a support layer; the circuit substrate, the circuit substrate the thermopile structure board with enclose between the supporting layer and become to have first cavity, just the thermopile structure sets up the top of first cavity, the bottom of first cavity disposes the heat radiation reflecting plate. The thermopile sensor provided by the embodiment of the invention can improve the measurement precision.

Description

Thermopile sensor, manufacturing method thereof and electronic equipment

Technical Field

The invention relates to the technical field of sensor manufacturing, in particular to a thermopile sensor, a manufacturing method thereof and electronic equipment.

Background

The thermopile (thermal-pile) is an element capable of converting temperature difference and electric energy into each other, and is composed of two or more thermocouples connected in series, the thermoelectrical potentials output by the thermocouples are mutually superposed, and when the temperature difference occurs on two sides of the thermopile, current can be generated.

The thermopile sensor can be configured with various lenses and filters, thereby realizing applications in various application scenes such as temperature measurement (forehead temperature gun, ear temperature gun, food temperature detection and the like), qualitative/quantitative analysis of gas components, intelligent household appliances, lamp switches, medical equipment and the like.

However, the device accuracy of the existing thermopile sensor is to be improved.

Disclosure of Invention

The invention aims to provide a thermopile sensor, a manufacturing method thereof and electronic equipment, which can improve the measurement precision and are beneficial to miniaturization.

In order to achieve the above object, the present invention provides a thermopile sensor including, sequentially arranged in an incident radiation direction:

the thermal power generation device comprises a thermopile structure plate, a heat radiation induction area and a control unit, wherein the thermopile structure plate is provided with a thermal radiation induction area, and a thermopile structure is arranged in the thermal radiation induction area;

a support layer;

the circuit board, the thermopile structure board and enclose between the supporting layer and become to have a first cavity, just the thermopile structure sets up the top of first cavity, the bottom of first cavity disposes the heat radiation reflecting plate.

The invention also provides a manufacturing method of the thermopile sensor, which comprises the following steps:

providing a thermopile structure plate having a thermal radiation sensing region in which a thermopile structure is formed;

forming a supporting layer on the thermopile structure plate, wherein the supporting layer is provided with a first groove, and the first groove at least corresponds to the heat radiation sensing area;

providing a circuit substrate on which a heat radiation reflecting plate is formed;

and bonding the circuit substrate and the supporting layer, enabling the first groove to be clamped between the thermopile structure plate and the circuit substrate to form a first cavity, and enabling the heat radiation reflecting plate to be located below the thermopile structure.

The invention also provides an electronic device comprising the thermopile sensor of the invention.

Compared with the prior art, the technical scheme of the invention has the following beneficial effects:

according to the forming method of the thermopile sensor provided by the embodiment of the invention, the etching process is adopted to form the first groove at the part of the supporting layer opposite to the thermal radiation sensing area, and the supporting layer is bonded with the circuit substrate subsequently, so that the first groove is clamped between the thermopile structure plate and the circuit substrate to form the first cavity, the process is simple, the first cavity can be used for thermal insulation, the heat received by the thermopile structure is prevented from being conducted to the circuit substrate below the first cavity, the loss of the sensing information corresponding to the opened first groove is avoided, and the measurement precision of the sensor is improved; and, follow-up back with supporting layer and circuit substrate bonded, the thermal radiation reflecting plate that forms on circuit substrate is located first cavity below, and the thermal radiation reflecting plate is through the residual radiation reflection who will pierce through the thermopile structural slab backheat thermopile structural slab, can further avoid corresponding environmental information's loss, improves the measurement accuracy of sensor.

In the alternative, the thermal radiation isolation plate is formed below the thermal radiation reflection plate, and can isolate the heat generated by the circuit substrate, so that the heat of the circuit substrate is prevented from being transferred to the thermopile structure plate, and the measurement precision of the thermopile sensor is improved; and after the supporting layer is bonded with the circuit substrate subsequently, the first conductive interconnection structure is positioned below the thermopile structure, so that direct absorption of the first conductive interconnection structure on thermal radiation can be avoided, influence on a circuit substrate device is avoided, and the stability of signals is improved.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, it is obvious that the drawings in the following description are only embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

FIGS. 1-11 are schematic structural diagrams corresponding to steps in a method for manufacturing a thermopile sensor according to an embodiment of the present invention;

12-14 are schematic structural diagrams corresponding to steps in a method for manufacturing a thermopile sensor according to another embodiment of the present invention;

fig. 15-17 are schematic structural diagrams corresponding to steps in a method for manufacturing a thermopile sensor according to yet another embodiment of the present invention.

Detailed Description

As is known in the art, the device accuracy of the conventional thermopile sensor needs to be improved.

Through analysis, the traditional thermopile sensor is characterized in that a thermocouple pair is manufactured by depositing polycrystalline silicon/metal on a medium film to sense temperature information, then a heat insulation cavity is formed below the medium film by a back silicon anisotropic wet etching method to increase heat resistance, and the thermocouple pair is electrically connected to a circuit structure formed on the side edge of the thermocouple pair, so that the transmission of sensing signals is realized. However, the device formed by the method has no substrate structure below, and heat in the heat insulation cavity can still be lost in a certain form, so that the measurement accuracy of the thermopile sensor is not high.

In order to solve the technical problem, an embodiment of the present invention provides a thermopile sensor and a manufacturing method thereof, where the method includes: providing a thermopile structure plate having a thermal radiation sensing region in which a thermopile structure is formed; forming a supporting layer on the thermopile structure plate, wherein the supporting layer is provided with a first groove, and the first groove at least corresponds to the thermal radiation induction area; providing a circuit substrate on which a heat radiation reflecting plate is formed; and bonding the circuit substrate and the supporting layer, so that the first groove is clamped between the thermopile structure plate and the circuit substrate to form a first cavity, and the heat radiation reflecting plate is positioned below the thermopile structure.

Therefore, in the embodiment of the invention, the first groove is formed in the part of the supporting layer opposite to the thermal radiation sensing area by adopting an etching process, and after the supporting layer is bonded with the circuit substrate, the first groove is clamped between the thermopile structure plate and the circuit substrate to form the first cavity, so that the process is simple, the first cavity can be used for thermal insulation, the heat received by the thermopile structure is prevented from being conducted into the circuit substrate below the first cavity, the loss of the sensing information corresponding to the open first groove is avoided, and the measurement precision of the sensor is improved; and, follow-up back with supporting layer and circuit substrate bonded, the thermal radiation reflecting plate that forms on circuit substrate is located first cavity below, and the thermal radiation reflecting plate is through the residual radiation reflection who will pierce through the thermopile structural slab backheat thermopile structural slab, can further avoid corresponding environmental information's loss, improves the measurement accuracy of sensor.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are illustrated in detail for convenience of description on a heat radiation reflecting plate and a heat radiation separating plate formed on a circuit substrate.

Please refer to fig. 1 to fig. 11, which are schematic structural diagrams corresponding to steps in a manufacturing method of a sensor according to an embodiment of the present invention.

As shown in fig. 1, a thermopile structure plate 20 is provided, the thermopile structure plate 20 having a heat radiation sensing region 20A, the heat radiation sensing region 20A having a thermopile structure formed therein.

The provided thermopile structure plate 20 may include a first substrate 200 on which the thermopile structure is formed on the first substrate 200. The first base 200 may be any suitable substrate material known to those skilled in the art, such as a bulk semiconductor substrate material of silicon, germanium, silicon germanium, gallium arsenide, indium phosphide, or the like.

In this embodiment, the step of providing the thermopile structure plate includes:

providing a first substrate 200, wherein a semiconductor layer 202 is formed on the surface of the first substrate 200;

and carrying out N-type and/or P-type ion doping on a partial region of the semiconductor layer 202 to form an N-type doped region and/or a P-type doped region as the thermopile structure.

Specifically, a semiconductor layer 202 and a dielectric layer 201 are formed on the first substrate 200, the semiconductor layer 202 is used to form a thermopile structure, the material of the semiconductor layer 202 may be an undoped semiconductor layer (e.g., polysilicon or monocrystalline silicon), or an N-type doped or P-type doped semiconductor layer, and the semiconductor layer 202 may be formed through an epitaxial process or an ion implantation process. The dielectric layer 201 is used for isolating the thermopile structure from the first substrate, and the material of the dielectric layer 201 includes at least one of silicon oxide, silicon nitride, and silicon oxynitride.

In this embodiment, the first base 200, the dielectric layer 201, and the semiconductor layer 202 are formed by a silicon-on-insulator substrate, the first base 200 is bottom-layer monocrystalline silicon of the silicon-on-insulator substrate, the dielectric layer 201 is silicon dioxide in the silicon-on-insulator substrate, and the semiconductor layer 202 is top-layer monocrystalline silicon of the silicon-on-insulator substrate. At least one thermally-induced microstructure is formed as a thermopile structure by implanting N-type and/or P-type ion doping into a portion of the semiconductor layer 202.

Wherein the distribution area of the thermopile structure serves as a heat radiation sensing area 20A, and the area at the periphery of the heat radiation sensing area 20A is used for the subsequent fabrication of a second conductive interconnection structure.

The thermopile structure in this embodiment includes a first thermal sensing microstructure 203a and a second thermal sensing microstructure 203b which are different in material, the first thermal sensing microstructure 203a is N-type doped single crystal silicon, and the second thermal sensing microstructure 203b is P-type doped single crystal silicon. The first thermal-sensing microstructures 203a and the second thermal-sensing microstructures 203b may be linear (e.g., straight line or curved line or broken line), array, or comb. The first thermal sensing microstructure 203a and the second thermal sensing microstructure 203b may have a substantially symmetrical structure, so that a substantially symmetrical thermal sensing effect is generated between the first thermal sensing microstructure 203a and the second thermal sensing microstructure 203b, thereby improving the measurement accuracy of the thermopile sensor.

In addition, the entire distribution area of the first thermal sensing microstructure 203a and the entire distribution area of the second thermal sensing microstructure 203b may be completely side by side in the plane of the thermopile structure plate 20 without overlapping, or may be partially nested to at least partially overlap, and optionally, the entire distribution area of the first thermal sensing microstructure 203a and the entire distribution area of the second thermal sensing microstructure 203b may partially overlap in the plane of the thermopile structure plate 20, for example, the first thermal sensing microstructure 203a and the second thermal sensing microstructure 203b are both comb-shaped structures, and a part of comb teeth of the first thermal sensing microstructure 203a are inserted into corresponding comb tooth gaps of the second thermal sensing microstructure 203b, so that the performance of the thermopile sensor may be further improved without increasing the surface area of the thermopile sensor.

It should be noted that, in this embodiment, the first thermal-sensing microstructure 203a and the second thermal-sensing microstructure 203b are both single-layer structures, but the technical solution of the present invention is not limited thereto, and in other embodiments of the present invention, the first thermal-sensing microstructure 203a and the second thermal-sensing microstructure 203b may also be stacked structures, and at this time, the first thermal-sensing microstructure 203a and the second thermal-sensing microstructure 203b may be formed by performing ion implantation into the semiconductor layer 202 for multiple times, and the concentration or energy or doping type of two adjacent ion implantations is different. In addition, the materials of the first thermal sensing microstructure 203a and the second thermal sensing microstructure 203b are not limited to doped semiconductors, and in other embodiments of the present invention, the corresponding thermal sensing microstructures may be formed on the first substrate 200 by at least one of patterned etching of a metal layer, patterned etching of a semiconductor layer, metal silicidation of a semiconductor layer, and the like, so that the materials of the thermal sensing microstructures may also be at least one of metal, undoped semiconductor, metal silicide, and the like.

Next, referring to fig. 2-3, a supporting layer 601 is formed on the thermopile structure plate 20, the supporting layer 601 is formed with a first groove 600, and the first groove 600 at least corresponds to the thermal radiation sensing region 20A;

in one embodiment, referring to fig. 2, a first conductive interconnection structure electrically connected to the thermopile structure may be formed on the thermopile structure plate before the step of forming the support layer on the thermopile structure plate.

Wherein the first conductive interconnect structure is for subsequent electrical connection with a readout interconnect structure.

A first conductive interconnection structure, which may be a single metal layer, may be formed on the semiconductor layer 202 through a series of processes of metal layer deposition, photolithography, etching, etc., or a metal lift-off (liff-off) process to reduce the integration thickness of the thermopile sensor.

The first conductive interconnect structure may include a first conductive interconnect line 300a electrically connected to the first heat-sensing microstructure 203a, and a second conductive interconnect line 300b electrically connected to the second heat-sensing microstructure 203b.

In an embodiment of the present invention, the material of the first conductive interconnect structure may be one or more of a metal and/or a metal silicide material such as copper, titanium, aluminum, tungsten, and the like.

Referring to fig. 3, a support layer 601 is formed on the first conductive interconnect structure and the thermopile structure plate.

In this embodiment, a support layer 601 is formed on the first conductive interconnection structure and the thermopile structure plate, and the support layer 601 is etched to form a first trench 600 at a portion opposite to the heat radiation sensing region 20A.

The depth of the first grooves 600 of the support layer 601 is less than or equal to the thickness of the support layer 601. A layer of support material (not shown) may be formed by a deposition process, the layer of support material covers the first conductive interconnect 300a and the second conductive interconnect 300b and the thermopile structure, the layer of support material is patterned by a photolithography and etching process to form the first trench 600, and the remaining layer of support material forms the support layer 601. The supporting layer 601 is used to provide a basis for the subsequent formation of the first cavity, and on the other hand, the supporting layer 601 may also cover the first conductive interconnection line 300a and the second conductive interconnection line 300b and the thermopile structure, so as to prevent the corresponding structures from being contaminated or oxidized, and to achieve the necessary insulation isolation between the adjacent conductive interconnection lines in the adjacent first conductive interconnection structures.

The material of the support layer 601 may be one or more of silicon dioxide, silicon nitride, silicon oxynitride, and the like.

It should be noted that, in the embodiment of the present invention, before the supporting layer 601 is formed, the first interconnect structure may be further covered with the first isolation layer 301. The first isolation layer 301 is used to cover the first conductive interconnect 300a and the second conductive interconnect 300b and the thermopile structure to prevent contamination or oxidation of the corresponding structures and to achieve the necessary insulation isolation between adjacent conductive interconnects in adjacent first conductive interconnect structures. Meanwhile, in the process of etching the supporting layer 601 to form the first trench 600, the first isolation layer 301 may also serve as an etching stop layer, so as to avoid an influence on the first conductive interconnection structure in the process of etching the supporting layer 601.

Specifically, the first isolation material layer (not shown) may be formed by a deposition process, and the first isolation layer 301 may be formed by performing a top surface planarization process on the first isolation material layer by a Chemical Mechanical Polishing (CMP) process.

The material of the first isolation layer 301 may be one or more of silicon dioxide, silicon nitride, silicon oxynitride, and the like. When the first spacer layer 301 is used as an etch stop layer for the support layer 601, the material of the first spacer layer is different from the material of the support layer 601. Of course, in other embodiments, the material of the support layer may also be the same as the material of the first release layer.

Of course, in another embodiment, the supporting layer 601 may be directly formed on the first conductive interconnect structure, and the depth of the first trench 600 of the supporting layer 601 is smaller than the thickness of the supporting layer 601, so that the first conductive interconnect structure can also be prevented from being affected during the process of forming the first trench 600 by etching.

In the embodiment of the invention, the first groove 600 is formed in the part of the supporting layer 601 opposite to the thermal radiation sensing area by adopting an etching process, and after the supporting layer 601 is bonded with the circuit substrate, the first groove 600 is clamped between the thermopile structure plate and the circuit substrate to form the first cavity 602, so that the process is simple, the first cavity 602 can be used for thermal insulation, the heat received by the thermopile structure is prevented from being conducted to the circuit substrate below the first cavity 602, the loss of the sensing information corresponding to the open first groove 600 is avoided, and the measurement accuracy of the sensor is improved.

Referring to fig. 4, a circuit substrate 10 is provided, the circuit substrate 10 including a heat radiation corresponding region 20B corresponding to the heat radiation sensing region. In a specific embodiment, the projection of the heat radiation corresponding region 20B on the circuit substrate 10 is the same as the projection of the heat radiation sensitive region 20A on the thermopile structure plate 10;

the provided circuit substrate 10 may be a CMOS substrate that performs FEOL (front end of line) and BEOL (back end of line) processes and wafer probing, and has a circuit structure formed therein to process an electrical signal of the thermopile structure. Wherein the FEOL process and the BEOL process are both conventional process technologies in the CMOS integrated circuit manufacturing in the art, and the wafer probing is a conventional test scheme in the art for testing the performance of the CMOS integrated circuit, which is not described in detail herein.

It should be noted that, in the embodiment of the present invention, the heat radiation corresponding region 20B may be a region corresponding to the distribution of the device structure, and a projection of the heat radiation corresponding region 20B on the circuit substrate is the same as a projection of the heat radiation sensing region 20A on the thermopile structure plate, so that the heat radiation sensing region 20A and the heat radiation corresponding region 20B are overlapped in the subsequent bonding process, thereby achieving alignment between the thermopile substrate and the circuit substrate.

As shown in fig. 4, the circuit substrate 10 may include a second base 100, a device structure formed in the second base 100, and

readout interconnection structures

104a and 104b electrically connected to the device structure, wherein the

readout interconnection structures

104a and 104b are formed on the second base 100.

The second substrate 100 may be any suitable semiconductor substrate material known to those skilled in the art, such as silicon, silicon-on-insulator, germanium, silicon germanium, gallium arsenide, indium phosphide, etc. The second substrate 100 has formed therein corresponding device structures and device isolation structures located between adjacent device structures through a CMOS fabrication process, and the device structures may include at least one of MOS transistors, resistors, diodes, capacitors, memories, and the like.

In the embodiment of the present invention, the device structure is taken as an example of a MOS transistor, wherein the MOS transistor 102 may include a gate 102a, and a source 102b and a drain 102c located at two sides of the gate 102 a. The device isolation structure 101 may be formed by a local field oxidation process or a Shallow Trench Isolation (STI) process. The

read interconnect structures

104a, 104b may be electrically connected by bottom contact plugs that are in direct electrical contact with corresponding terminals of the device structure and a multi-layer metal interconnect structure that is electrically connected to the bottom contact plugs, thereby enabling electrical connection of the read

interconnect structures

104a, 104b to the device structure.

Wherein an interlayer dielectric material layer 103 is further formed on the second substrate 100 so as to isolate adjacent metal interconnection layers. The interlayer dielectric material layer 103 of the circuit substrate 10 also exposes openings of partial surfaces of the

readout interconnection structures

104a and 104b, respectively, to form a first probe point 108a and a second probe point 108b for wafer probe. The material of the interlayer dielectric material layer 103 may include at least one of silicon dioxide, silicon nitride, a low-K dielectric having a dielectric constant K lower than that of silicon dioxide, a high-K dielectric having a K higher than that of silicon dioxide, a metal nitride, and the like.

Next, referring to fig. 5, a heat radiation reflecting plate 702 is formed on the circuit substrate 10.

The thermal radiation reflecting plate 702 is used to reflect infrared radiation transmitted into the first cavity 602 (shown in fig. 7) back into the thermopile structure plate 20 during device operation, thereby improving the accuracy of the thermopile sensor.

In a specific embodiment, a thermal radiation separating plate 701 may be further formed on the circuit substrate 10 such that the thermal radiation separating plate 701 is positioned below the thermal radiation reflecting plate 702.

The thermal radiation isolation plate 701 can isolate heat generated by the circuit substrate, so that the heat of the circuit substrate is prevented from being transferred to the thermopile structure plate, and the measurement precision of the thermopile sensor is improved;

the material of the thermal radiation reflecting plate 702 is a conductive material and/or a photonic crystal material, the conductive material is one or more of a metal material, a metal silicide material, and a semiconductor material, the metal silicide may be titanium silicide (TiSi), tungsten silicide (WSi), or aluminum silicide (AlSi), and the like, and the doped semiconductor may be a polysilicon layer or an amorphous silicon layer or a silicon germanium layer doped with P-type or N-type dopant, for example. The material of the heat radiation spacer 701 may be a metal material.

Specifically, the heat radiation reflecting plate 702 and the heat radiation blocking plate 701 may be formed on the surface of the interlayer dielectric material layer 103 by a series of processes of metal deposition, photolithography, etching, or the like, or a metal lift-off (liff-off) process.

A bottom surface of the heat radiation reflecting plate 702 and a top surface of the heat radiation spacer 701 may be in contact, and a first passivation layer may be formed between the bottom surface of the heat radiation reflecting plate 702 and the top surface of the heat radiation spacer 701.

In an alternative example, the circuit substrate 10 includes a thermal radiation corresponding region 20B corresponding to the thermal radiation sensing region, and the process of forming the thermal radiation spacer 701 and the thermal radiation reflecting plate 702 may include:

forming a layer of isolating material (not shown) overlying the circuit substrate;

forming a layer of reflective material (not shown) overlying the layer of spacer material;

removing the reflective material layer and the isolation material layer outside the thermal radiation corresponding region 20B, and using the remaining reflective material layer as the thermal radiation reflecting plate 702 and the remaining isolation material layer as the thermal radiation isolating plate 701.

Wherein, when the heat radiation separation plate 701 and the heat radiation reflection plate 702 are metal materials, the separation material layer and the reflection material layer may be formed by a deposition process, respectively. When the thermal radiation spacer 701 and the thermal radiation reflecting plate 702 are metal silicides, the step of forming the spacer material layer includes: firstly, forming a silicon layer, and then carrying out metal silicification on the silicon layer; also, the reflective material layer may be formed in this manner. When the thermal radiation spacer 701 and the thermal radiation reflecting plate 702 are doped semiconductors, the forming of the spacer material layer includes: forming a semiconductor layer, and then carrying out N-type and/or P-type doping on the semiconductor layer; also, the reflective material layer may be formed in this manner.

In the embodiment of the present invention, a first passivation layer may be further formed between the heat radiation spacer 701 and the heat radiation reflection plate 702, thereby achieving the isolation of the heat radiation spacer 701 and the heat radiation reflection plate 702. Specifically, the first passivation material layer may be formed to completely cover the reflective material layer after forming the isolation material layer covering the side of the circuit substrate provided with the readout interconnection structure and before forming the reflective material layer covering the isolation material layer. The first passivation material layer may be formed using a deposition process. Of course, the step of removing the reflective material layer and the spacer material layer outside the heat radiation corresponding region 20B further includes: the first passivation layer outside the heat radiation corresponding region 20B is removed to form a first passivation layer.

Of course, for subsequent convenience of bonding the circuit substrate and the supporting layer 601, in an embodiment, after forming the thermal radiation reflecting plate 702 and the thermal radiation isolating plate 701, before bonding the circuit substrate and the supporting layer 601, the method further includes:

a second passivation layer is formed to cover the circuit substrate exposed by the heat radiation reflection plate 702.

The second passivation layer provides a planar basis for subsequent bonding of the support layer to the circuit substrate. The thickness of the second passivation layer is not limited, and the surface of the second passivation layer may be flush with the surface of the thermal radiation reflection plate 702 or the second passivation layer may also cover the thermal radiation reflection plate 702 as long as the surface of the second passivation layer is ensured to be a plane.

The material of the second passivation layer comprises at least one of silicon oxide, silicon nitride, silicon oxynitride, low-K dielectric, high-K dielectric and metal nitride.

Of course, in another embodiment, the second passivation layer may be formed to cover both the exposed circuit substrate of the thermal radiation reflecting plate 702 and the thermal radiation reflecting plate 702, so as to provide a planar base for the subsequent bonding of the supporting layer and the circuit substrate.

It should be noted that the thermal radiation reflecting plate 702 and the thermal radiation spacer 701 cover at least the thermal radiation corresponding region 20B of the circuit substrate, which means that the thermal radiation reflecting plate 702 and the thermal radiation spacer 701 may cover the peripheral region of the thermal radiation corresponding region 20B in addition to the thermal radiation corresponding region 20B of the circuit substrate.

In another alternative example, the process of forming the thermal radiation spacer and the thermal radiation reflecting plate may include: forming a dielectric layer (not shown) on the circuit substrate, the dielectric layer having an opening; filling the opening to form the thermal radiation isolation plate; the thermal radiation reflecting plate 702 is formed on the thermal radiation separating plate, and the thermal radiation reflecting plate covers at least the thermal radiation separating plate. In particular, in the step of filling the opening to form the thermal radiation spacer, the thermal radiation spacer may completely fill or even cover the opening such that the thermal radiation reflecting plate is located above the opening rather than filling into the opening, and in another embodiment, the thermal radiation spacer may also partially fill the opening such that the thermal radiation reflecting plate is partially or completely located within the opening.

In another alternative example, the process of forming the thermal radiation spacer and the thermal radiation reflecting plate may include: forming a dielectric material layer (not shown) covering the circuit substrate; removing the dielectric material layer in the heat radiation corresponding region to form an opening (not shown), and taking the residual dielectric material layer as a dielectric layer; sequentially forming an isolation material layer and a reflection material layer which conformally cover the dielectric layer and the opening, wherein the reflection material layer is positioned above the isolation material layer; and removing the isolating material layer and the reflecting material layer outside the opening, and taking the residual isolating material layer as a thermal radiation isolating plate and the residual reflecting material layer as a thermal radiation reflecting plate. In this step, the opening may be an opening only used for forming the thermal radiation isolation plate and the thermal radiation reflection plate, and the corresponding opening depth is only adapted to the sum of the thicknesses of the thermal radiation isolation plate and the thermal radiation reflection plate, and may also be smaller than the sum of the thicknesses of the thermal radiation isolation plate and the thermal radiation reflection plate. Note that, when the spacer material layer and the reflective material layer outside the opening are removed, a Chemical Mechanical Polishing (CMP) process may be used.

In the embodiment of the present invention, the first passivation layer is further formed after the thermal radiation spacer 701 is formed and before the thermal radiation reflecting plate 702 is formed, thereby achieving the isolation of the thermal radiation spacer 701 and the thermal radiation reflecting plate 702. Specifically, the step of forming the heat radiation reflecting plate 702 and the heat radiation separating plate 701 on the circuit base, 10 includes:

forming an isolation material layer covering the circuit substrate;

forming a first passivation material layer overlying the isolation material layer;

forming a layer of reflective material overlying the layer of spacer material;

and removing the reflecting material layer, the first passivation material layer and the isolation material layer outside the heat radiation corresponding region, wherein the rest of the reflecting material layer is taken as the heat radiation reflecting plate 702, the rest of the first passivation material layer is taken as the first passivation layer, and the rest of the isolation material layer is taken as the heat radiation isolating plate 701.

In another alternative example, the process of forming the thermal radiation spacer and the thermal radiation reflecting plate may include: forming a first dielectric layer (not shown) on the circuit substrate, the first dielectric layer having a first opening; filling the first opening to form the heat radiation isolation plate, wherein the surface of the heat radiation isolation plate is flush with the surface of the first dielectric layer; forming a second dielectric layer, wherein the second dielectric layer covers the first dielectric layer and the heat radiation isolation plate; patterning the second dielectric layer to form a second opening, wherein the depth of the second opening is less than or equal to the thickness of the second dielectric layer; filling the second opening to form the thermal radiation reflecting plate.

Specifically, a first dielectric layer (not shown) may be deposited on the surface of the circuit substrate, and the first dielectric layer further fills the first needle measurement point 108a and the second needle measurement point 108b; photoetching and etching the first dielectric layer to form a first opening in the first dielectric layer, wherein the first opening at least exposes the heat radiation corresponding region 20B; depositing a thermal radiation isolation material to fill the first opening, etching to remove the excess thermal radiation isolation material, and forming the remaining thermal radiation isolation material into a thermal radiation isolation plate 701; forming a second dielectric layer on the thermal radiation isolation plate 701, wherein the second dielectric layer covers the first dielectric layer and the thermal radiation isolation plate 701, and photoetching and etching the second dielectric layer to form a second opening on the second dielectric layer, wherein the second opening at least exposes the thermal radiation corresponding region 20B. The depth of the second opening may be less than or equal to the thickness of the second dielectric layer, and when the depth of the second opening is equal to the thickness of the second dielectric layer, the lower surface of the thermal radiation reflecting plate 702 formed by subsequently filling the second opening is in contact with the upper surface of the thermal radiation insulating plate 701; when the depth of the second opening is less than the thickness of the second dielectric layer, the second dielectric layer may also function to isolate the heat radiation reflecting plate 702 from the heat radiation insulating plate 701, i.e., the second dielectric layer between the heat radiation reflecting plate 702 and the heat radiation insulating plate 701 functions as a first passivation layer in other embodiments.

In the embodiment of the present invention, a third passivation layer having a planar surface is further formed on the heat radiation reflection plate 702, and the third passivation layer covers at least the heat radiation reflection plate 702, and is used to protect the heat radiation reflection plate 702. In other embodiments, the third passivation layer may not be formed.

The material of the third passivation layer comprises at least one of silicon oxide, silicon nitride, silicon oxynitride, low-K dielectric, high-K dielectric and metal nitride.

Specifically, a third passivation layer covering the heat radiation reflecting plate 702 may be formed after the heat radiation separating plate 701 and the heat radiation reflecting plate 702 are formed. Alternatively, a deposition process may be used to deposit a third passivation material layer (not shown), and a Chemical Mechanical Polishing (CMP) process may be used to planarize the top surface of the third passivation material layer to form a planar third passivation layer. Of course, in other embodiments, the top surface of the thermal radiation reflecting plate 702 may not be covered with the third passivation layer, but it is necessary to ensure that the surfaces of the dielectric layers on both sides of the thermal radiation reflecting plate 702 are flush with the surface of the thermal radiation reflecting plate 702 or higher than the thermal radiation reflecting plate 702 to ensure the subsequent bonding process.

In the present embodiment, the first passivation layer, the second passivation layer, and the third passivation layer may constitute a passivation layer 720 (shown in fig. 6).

Referring to fig. 6, the circuit substrate 10 and the supporting layer 601 are bonded, the first trench 600 is sandwiched between the thermopile structure plate 20 and the circuit substrate 10 to form a first cavity 602, the heat radiation sensing region 20A corresponds to the heat radiation corresponding region 20B, and the first conductive interconnection structure, the heat radiation reflection plate 702, and the heat radiation isolation plate 701 are all located below the thermopile structure.

First, the circuit substrate is bonded to the support layer 601 through a suitable bonding process, and after the support layer 601 is bonded to the circuit substrate 10, the first conductive interconnection structure, the heat radiation reflection plate 702, and the heat radiation isolation plate 701 are all located under the thermopile structure. The first electrically conductive interconnect structure is located the below of thermopile structure and can not form the infrared radiation and block, makes the route of infrared radiation transmission to thermopile structure unobstructed, can reduce infrared radiation simultaneously and transmit to keeping apart the cavity, improves thermopile sensor's measurement accuracy, can avoid first electrically conductive interconnect structure to the direct absorption of thermal radiation simultaneously, avoids causing the influence to the circuit substrate device, improves the stability of signal.

In the embodiment of the present invention, the step of bonding the circuit substrate and the supporting layer 601 specifically includes: the thermopile structure plate is fixed upside down on the side of the circuit substrate having the

readout interconnect structures

104a, 104b.

In the embodiment of the present invention, after the thermopile structure plate and the support layer 601 are bonded, the vertical distance between the thermal radiation reflecting plate 702 and the thermopile structure is an odd number multiple of 1/4 of the wavelength of infrared radiation.

Specifically, the vertical distance between the thermal radiation reflecting plate 702 and the thermopile structure may be adjusted by controlling the bonding process, so that the radiation reflecting plate exerts the maximum reflection capability on the residual radiation penetrating through the thermopile structure plate.

In particular, the vertical distance between the thermal radiation reflecting plate 702 and the thermopile structure 203a/203b may be about an odd multiple of 1/4 of the wavelength λ of the incident radiation, e.g., about λ/4, 3 λ/4, 5 λ/4, etc. This enables the maximum reflection capability of the thermal radiation reflection plate 702 for the residual radiation penetrating the thermopile structure plate.

Referring to fig. 7, in the embodiment of the present invention, a side of the thermopile structure plate facing away from the circuit substrate is further thinned, and the first substrate 200 is removed. Therefore, the integration thickness can be reduced, and the manufacturing difficulty of the subsequent second conductive interconnection structure is reduced.

Specifically, the first substrate 200 may be removed by a suitable removal process (e.g., chemical mechanical polishing, etching, or stripping) according to the material of the first substrate 200.

Referring to fig. 8, the method for manufacturing the thermopile sensor of the present embodiment further includes: forming second

conductive interconnect structures

40a, 40b, the second

conductive interconnect structures

40a, 40b electrically connecting the

readout interconnect structures

104a, 104b and the first conductive interconnect structures. The second

conductive interconnect structures

40a, 40b are used to output electrical signals of the first and

readout interconnect structures

104a, 104b. Wherein the second conductive interconnection structures 40A, 40b are formed on the thermopile structure plate 20 at the periphery of the heat radiation sensing region 20A.

In a specific embodiment, the second conductive interconnect structure includes a first plug located within the thermopile structure plate, the first plug connecting the first conductive interconnect structure;

a second plug penetrating through the thermopile structure plate and the support layer and electrically connected with the readout circuit; and a plug interconnect on the thermopile structure plate, the plug interconnect connecting the first plug and the second plug.

Specifically, the step of forming the second

conductive interconnection structures

40a and 40b may include: forming a first interconnect via (not shown) and a second interconnect via (not shown) on a side of the thermopile structure plate facing away from the circuit substrate, the first interconnect via exposing a first electrically conductive interconnect structure of the thermopile structure plate, the second interconnect via exposing a readout interconnect structure in the circuit substrate; forming an insulating medium layer on the side walls of the first interconnection through hole and the second interconnection through hole; forming a first plug in the first interconnect via and a second plug in the second interconnect via; and forming a plug interconnection line on the surface of the thermopile structure plate, wherein the plug interconnection line is connected with the first plug and the second plug.

As an example, the second

conductive interconnection structures

40a, 40b are formed by a re-wiring process, which specifically includes a process of forming the

second plugs

401a, 401b, a process of forming the

first plugs

403a, 403b, and a process of forming the

plug interconnection lines

402a, 402 b. The order of performing the processes for forming the

second plugs

401a and 401b and the processes for forming the

first plugs

403a and 403b is not limited. The second plug 401a, the first plug 403a, and the plug interconnect line 402a constitute a second conductive interconnect structure 40a, and the second plug 401b, the first plug 403b, and the plug interconnect line 402b constitute a second conductive interconnect structure 40b.

The process of forming the first plugs 403a, 403b specifically includes: first, the thermopile structure plate 20, the first isolation layer 301, the support layer 601, the second passivation layer, and a portion of the interlayer dielectric material layer 103 at the periphery of the thermal radiation sensing region 20A are etched to form second contact holes (not shown) respectively exposing a portion of the top surfaces of the readout interconnection structures 104a, 104 b; then, covering an insulating medium layer on the side wall of the second contact hole, wherein the insulating medium layer is used for insulating and isolating the conductive material filled subsequently from the thermopile structure plate 20, the material of the insulating medium layer may include at least one of silicon oxide, silicon nitride, silicon oxynitride, metal nitride, high-K dielectric, low-K dielectric, and the like, and the bottom of the insulating medium layer exposes part of the top surfaces of the corresponding readout interconnection structures 104a and 104 b; next, the second contact hole is filled with a conductive material such as metal (e.g., tungsten, copper), and the excess conductive material covering the surface of the dielectric layer 201 is removed by a chemical mechanical polishing process, so as to form first plugs 403a and 403b with top surfaces flush with the top surface of the dielectric layer 201. In this embodiment, the bottom end of the first plug 403a is electrically connected to the readout interconnect structure 104 a. The bottom end of the first plug 403b is electrically connected to the readout interconnect structure 104b.

The process of forming the

second plugs

401a, 401b specifically includes: first, the thermopile structure plate 20 at the periphery of the thermal radiation sensing region 20A is etched to form a first contact hole (not shown) exposing a part of the surface of the first conductive interconnection structure; then, covering an insulating medium layer on the side wall of the first contact hole, wherein the insulating medium layer is used for insulating and isolating the conductive material filled subsequently from the thermopile structure plate 20, the material of the insulating medium layer may include at least one of silicon oxide, silicon nitride, silicon oxynitride, metal nitride, a high-K medium, a low-K medium, and the like, and the bottom of the insulating medium layer is exposed out of the surface of the corresponding first conductive interconnection structure; next, the first contact hole is filled with a conductive material such as metal (e.g., tungsten, copper), and the excess conductive material covering the surface of the dielectric layer 201 is removed by a chemical mechanical polishing process, so as to form

second plugs

401a and 401b having top surfaces flush with the top surface of the dielectric layer 201. In this embodiment, the bottom end of the second plug 401a is electrically connected to the first conductive interconnection line 300 a. The bottom end of the second plug 401b is electrically connected to the second conductive interconnection 300b.

The process of forming the

plug interconnect lines

402a, 402b specifically includes: depositing a metal layer on the surfaces of the

first plugs

403a and 403b, the

second plugs

401a and 401b and the dielectric layer 201; the metal layer is subjected to photolithography and etching to remove the metal layer in the thermal radiation sensing area 20A, and the remaining metal layer forms plug

interconnect lines

402a, 402b, the plug interconnect line 402a covers the top ends of the first plug 403a and the second plug 401a and electrically connects the top end of the first plug 403a and the top end of the second plug 401a, and the plug interconnect line 402b covers the top ends of the first plug 403b and the second plug 401b and electrically connects the top end of the first plug 403b and the top end of the second plug 401b.

It should be noted that when the thermopile structure plate 20 is formed based on a non-conductive material plate, the insulating medium layer may be omitted on the sidewalls of the conductive material in the

second plugs

401a, 401b and the

first plugs

403a, 403b.

Referring to fig. 12-14, in another embodiment of the present invention, the forming process of the second conductive interconnection structure may further include: first forming a thermopile second sub-plug 406a, 406b on the thermopile structure plate, electrically connected to the first conductive interconnection structure, before bonding the thermopile structure plate and the circuit substrate; forming circuit substrate second sub-plugs 404a, 404b on the circuit substrate, electrically connected to the readout circuit; after the circuit substrate is bonded to the support layer, the second sub-plugs 406a and 406b of the thermopile and the second sub-plugs 404a and 404b of the circuit substrate are electrically connected through a conductive bonding material. After the thermopile structure plate and the circuit substrate are bonded,

first plugs

403a and 403b penetrating through the thermopile structure plate and the support layer and electrically connected with the readout circuit are formed, and the

first plugs

403a and 403b serve as output terminals to output corresponding electrical signals.

Referring to fig. 15-17, in yet another embodiment of the present invention, before bonding the thermopile structure plate and the circuit substrate, first forming a

first thermopile sub-plug

407a, 407b and a second thermopile sub-plug 406a, 406b on the thermopile structure plate, wherein the

first thermopile sub-plug

407a, 407b penetrates through the thermopile structure plate and the support layer, and the second thermopile sub-plug 406a, 406b is electrically connected to the first conductive interconnection structure;

and circuit substrate first sub-plugs 405a, 405b and circuit substrate second sub-plugs 404a, 404b electrically connected with the readout circuitry are formed on the circuit substrate;

after the circuit substrate is bonded to the support layer, the thermopile second sub-plugs 406a and 406b and the circuit substrate second sub-plugs 404a and 404b are electrically connected through a conductive bonding material, and the thermopile first sub-plugs 407a and 407b and the circuit substrate first sub-plugs 405a and 405b are electrically connected through a conductive bonding material.

With continued reference to fig. 9-11, in an embodiment of the present invention, after the second conductive interconnect structures 40A, 40b are formed, a cap 50 is further disposed on the thermopile sensor to protect the thermal radiation sensing region 20A of the thermopile sensor.

Specifically, a cover 50 with a protection slot 503 is provided, a radiation penetrating window (not shown in the figure) is further provided on the cover of the protection slot 503 on the side facing away from the thermopile structure plate, and the radiation penetrating window is at least vertically aligned with the thermopile structure;

the radiation transmission window is used for transmitting infrared rays.

The material of the radiation transmission window comprises one or two of a semiconductor (such as silicon, germanium or silicon-on-insulator, etc.) and an organic filter material (such as polyethylene, polypropylene, etc.).

The shape of the radiation penetrating window can be regular shapes such as rectangle, square or circle, and can also be other irregular shapes.

It should be noted that the manufacturing method may further include: and an infrared antireflection film is arranged above the radiation penetration window.

Then, the cover 50 is bonded to the thermopile structure plate, and the protection slot 503 is sandwiched between the cover 50 and the thermopile structure plate to form a second cavity 502, and the second cavity 502 is aligned with the first cavity 602; and (c) a second step of,

the cap 50 is trimmed to expose at least a portion of the surface of the second conductive interconnect structure.

Wherein, the material of closing cap 50 can be glass, plastics, semiconductor etc. through with 50 bonded closures are arrived thermopile structural slab deviates from circuit substrate's surface, in order to cover the thermal radiation induction zone 20A of thermopile structural slab, and, based on the setting of protection groove makes the thermal radiation induction zone 20A top of thermopile structural slab is the cavity structures, has avoided the contact of relevant material to the thermal radiation induction zone of thermopile structural slab to avoid causing the influence to the thermal radiation induction zone 20A of thermopile structural slab.

As an example, the step of providing the cover 50 with the protection groove 503 is: providing a third substrate 500, depositing a cavity material layer on the third substrate 500, etching the cavity material layer until the surface of the third substrate 500 is exposed to form a protection groove 503 in the cavity material layer, and forming a cavity wall 501 by the remaining cavity material; as another example, the third substrate 500 is provided, and then the third substrate 500 is etched by a partial thickness to form the protection trench 503 in the third substrate 500, where the material of the cavity wall 501 is the same as the material of the third substrate 500;

then, bonding the cover 50 to the dielectric layer 201, and sandwiching the protection slot 503 between the cover 50 and the thermopile structure plate 20 to form a second cavity 502, and aligning with the first cavity 602; the setting of second cavity can the minimize superstructure directly absorb the thermal radiation of incidence, stores the thermal radiation of incidence to a certain extent simultaneously for the thermopile structure furthest receives the radiant heat of incidence, can improve the performance of thermopile sensor from this.

Next, the edges of the third substrate 500 are trimmed by a laser cutting process or the like to expose the surfaces of the

interconnect lines

402a, 402b, thereby making the

interconnect lines

402a, 402b respective externally connected contact pads of the thermopile sensor.

The method for manufacturing the thermopile sensor provided by the embodiment of the invention adopts an etching process to form the first groove on the part of the support layer opposite to the thermal radiation sensing area, and then bonds the support layer with the circuit substrate, so that the first groove is clamped between the thermopile structure plate and the circuit substrate to form the first cavity, the process is simple, the first cavity can be used for thermal insulation, the heat received by the thermopile structure is prevented from being conducted into the circuit substrate below the first cavity, the loss of the sensing information corresponding to the open first groove is avoided, and the measurement accuracy of the sensor is improved; moreover, after the supporting layer is bonded with the circuit substrate subsequently, the thermal radiation reflecting plate formed on the circuit substrate is positioned below the first cavity, and the thermal radiation reflecting plate reflects residual radiation penetrating through the thermopile structure plate back to the thermopile structure plate, so that the loss of corresponding environmental information can be further avoided, and the measurement precision of the sensor is improved; furthermore, a thermal radiation isolation plate is formed below the thermal radiation reflection plate, and the thermal radiation isolation plate can isolate heat generated by the circuit substrate, so that the heat of the circuit substrate is prevented from being transferred to the thermopile structure plate, and the measurement precision of the thermopile sensor is improved; after the supporting layer and the circuit substrate are bonded subsequently, the first conductive interconnection structure is located below the thermopile structure, so that direct absorption of the first conductive interconnection structure on heat radiation can be avoided, influence on a circuit substrate device is avoided, and signal stability is improved.

In order to solve the above problem, embodiments of the present invention further provide a thermopile sensor.

As shown in fig. 11, a thermopile sensor according to an embodiment of the present invention includes, sequentially arranged along the incident radiation direction (i.e., from top to bottom in fig. 11): a thermopile structure plate 20, the thermopile structure plate 20 having a thermal radiation sensing region 20A, the thermal radiation sensing region 20A having a thermopile structure disposed therein; a support layer 601; a first cavity 602 is defined between the circuit substrate 10, the thermopile structure plate 20, and the support layer 601, the thermopile structure is disposed above the first cavity 602, and a thermal radiation reflection plate 702 is disposed at the bottom of the first cavity 602.

The bottom of the first cavity may be provided with a thermal radiation reflecting plate, meaning that an upper surface of the thermal radiation reflecting plate may be exposed to the first cavity, or an insulating layer may be disposed between the thermal radiation reflecting plate and the first cavity.

The thermal radiation reflecting plate 702 is used to reflect infrared radiation transmitted into the first cavity 602 back into the thermopile structure plate during device operation, thereby improving the accuracy of the thermopile sensor.

The material of the thermal radiation reflecting plate 702 is a conductive material and/or a photonic crystal material, the conductive material is one or more of a metal material, a metal silicide material, and a semiconductor material, the metal silicide may be titanium silicide (TiSi), tungsten silicide (WSi), or aluminum silicide (AlSi), and the like, and the doped semiconductor may be a polysilicon layer or an amorphous silicon layer or a silicon germanium layer doped with P-type or N-type dopant, for example.

The thermopile sensor according to the embodiment of the present invention may be thermally insulated by the first cavity 602, so as to prevent heat received by the thermopile structure from being conducted to the circuit substrate 10 below the first cavity 602. The thermal radiation reflecting plate 702 is located below the first cavity 602, and can reflect the residual radiation penetrating through the thermopile structure plate back to the thermopile structure plate, so that the loss of corresponding environmental information can be further avoided, and the measurement accuracy of the sensor is improved.

With continued reference to FIG. 11, in an embodiment of the present invention, the thermopile sensor further comprises: a first conductive interconnect structure electrically connected to the thermopile structure, the first conductive interconnect structure disposed below the thermopile structure; and a thermal radiation isolation plate 701 positioned at the bottom of the first cavity 602 and below the thermal radiation reflection plate 702.

the material of the heat radiation shielding plate 701 is a metal material.

In an embodiment of the present invention, a first passivation layer may be formed between the thermal radiation spacer 701 and the thermal radiation reflecting plate 702, thereby achieving the isolation of the thermal radiation spacer 701 from the thermal radiation reflecting plate 702.

In the embodiment of the present invention, a second passivation layer surrounding the heat radiation reflection plate 702 and the heat radiation separation plate 701 may be further formed, and a surface of the second passivation layer may be flush with a surface of the heat radiation reflection plate 702, or the second passivation layer may cover the heat radiation reflection plate 702.

In an embodiment of the present invention, a third passivation layer may be formed on the thermal radiation reflecting plate 702 to cover at least the thermal radiation reflecting plate 702, and the upper surface of the thermal radiation reflecting plate 702 may be protected by the third passivation layer. In other embodiments, the upper surface of the heat radiation reflecting plate 702 may be exposed by a third passivation layer.

In this embodiment, the first passivation layer, the second passivation layer, and the third passivation layer form the passivation layer 720.

It should be noted that the thermal radiation reflecting plate 702 and the thermal radiation separating plate 701 cover at least the thermal radiation sensing area, that is, the thermal radiation reflecting plate 702 and the thermal radiation separating plate 701 may cover only the thermal radiation sensing area, or may cover both the thermal radiation sensing area and the periphery of the thermal radiation sensing area. Therefore, in an embodiment, when the thermal radiation reflecting plate 702 and the thermal radiation spacer 701 do not completely cover the periphery of the thermal radiation sensing region, the thermal radiation reflecting plate 702 and the thermal radiation spacer 701 are surrounded by the second passivation layer, which provides a planar bonding base for bonding with the support layer 601.

In one embodiment, the vertical distance between the thermal radiation reflecting plate 702 and the thermopile structure of the first thermal sensing microstructure 203a, the second thermal sensing microstructure 203b, etc. is an odd multiple of 1/4 of the wavelength λ of the incident radiation, such as λ/4, 3 λ/4, 5 λ/4, etc., thereby enabling a maximum reflection capability of the thermal radiation reflecting plate 702 for the residual radiation penetrating the thermopile structure plate 20.

The thermopile sensor according to the present embodiment may receive thermal radiation from a side of the thermopile structure plate 20 facing away from the circuit substrate 10, so as to avoid direct absorption of the thermal radiation by the circuit substrate 10 and the first conductive interconnection structure (e.g., metal wires, etc.), and may also perform thermal insulation through the first cavity 602, so as to prevent heat received by the thermopile structure from being conducted into the circuit substrate 10 below the first cavity 602. The thermal radiation reflecting plate 702 is positioned below the first cavity 602, and can reflect residual radiation penetrating through the thermopile structure plate back to the thermopile structure plate, so that loss of corresponding environmental information can be further avoided, and the measurement accuracy of the sensor is improved; further, the thermal radiation isolation plate 701 is located below the thermal radiation reflection plate 702, the thermal radiation isolation plate 701 can isolate heat generated by the circuit substrate, the heat of the circuit substrate is prevented from being transferred to the thermopile structure plate, and the measurement accuracy of the thermopile sensor is improved.

The thermopile structure plate 20 may be selected from any suitable material known to those skilled in the art, such as a semiconductor substrate material, e.g., silicon-on-insulator, germanium, silicon germanium, gallium arsenide, indium phosphide, etc. The thermopile structure in the thermopile structure plate 20 comprises at least one heat-sensing microstructure, which may be formed of any suitable heat-conducting material, for example, the material of the heat-sensing microstructure comprises at least one of a metal, an undoped semiconductor, a doped semiconductor, and a metal silicide, wherein the material of the undoped semiconductor or the doped semiconductor each comprises at least one of silicon, germanium, gallium arsenide, or indium phosphide, and the dopant of the doped semiconductor comprises an N-type (e.g., arsenic, germanium, etc.) or P-type (e.g., boron fluoride, phosphorus, etc.) dopant. Optionally, the thermopile structure plate 20 is a semiconductor substrate, and the thermal sensing microstructure in the thermopile structure includes N-type and/or P-type doped regions formed in the semiconductor substrate, so that the fabrication of the thermopile structure is compatible with a CMOS process, thereby simplifying the process and reducing the cost.

The thermopile structure plate 20 includes a first substrate 200, a dielectric layer 201, and a semiconductor layer 202 stacked in sequence from bottom to top, and the thermopile structure is formed in the semiconductor layer 202. The first base 200 may be any suitable substrate material known to those skilled in the art, such as a bulk semiconductor substrate material of silicon, germanium, silicon germanium, gallium arsenide, indium phosphide, or the like.

The semiconductor layer 202 and the dielectric layer 201 are formed on the first substrate 200, the semiconductor layer 202 is used for forming a thermopile structure, the material of the semiconductor layer 202 may be an undoped semiconductor layer (e.g., polysilicon or monocrystalline silicon), or an N-type doped or P-type doped semiconductor layer, and the semiconductor layer 202 may be formed through an epitaxial process or an ion implantation process. The dielectric layer 201 is used for isolating the thermopile structure from the first substrate, and the material of the dielectric layer 201 includes at least one of silicon oxide, silicon nitride, and silicon oxynitride.

In this embodiment, the first base 200, the dielectric layer 201, and the semiconductor layer 202 are formed by a silicon-on-insulator substrate, the first base 200 is bottom-layer monocrystalline silicon of the silicon-on-insulator substrate, the dielectric layer 201 is silicon dioxide in the silicon-on-insulator substrate, and the semiconductor layer 202 is top-layer monocrystalline silicon of the silicon-on-insulator substrate. At least one thermally-induced microstructure is formed as a thermopile structure by implanting N-type and/or P-type ions into a portion of the semiconductor layer 202.

The thermopile structure in this embodiment includes a first thermal sensing microstructure 203a and a second thermal sensing microstructure 203b, which are made of different materials, where the first thermal sensing microstructure 203a is N-type doped single crystal silicon, and the second thermal sensing microstructure 203b is P-type doped single crystal silicon. The first and second

heat sensing microstructures

203a and 203b may have a substantially symmetrical structure, so that a substantially symmetrical heat sensing effect is generated between the first and second

heat sensing microstructures

203a and 203b, thereby improving the measurement accuracy of the thermopile sensor.

It should be noted that in the embodiment, the first thermal-sensing microstructure 203a and the second thermal-sensing microstructure 203b are both single-layer structures, but the technical solution of the present invention is not limited thereto, and in other embodiments of the present invention, the first thermal-sensing microstructure 203a and the second thermal-sensing microstructure 203b may also be stacked structures respectively.

As an example, the thermopile structure plate 20 includes a dielectric layer 201 and a semiconductor layer 202, the material of the dielectric layer 201 includes at least one of silicon dioxide, silicon nitride, etc., the semiconductor layer 202 may be single crystal silicon or polycrystalline silicon, and the thermopile structure includes at least one heat-induced microstructure formed in the semiconductor layer 202.

The material of the first conductive interconnection structure may include metal such as copper, titanium, aluminum, tungsten, and/or metal silicide. The first conductive interconnect structure includes a first conductive interconnect 300a and a second conductive interconnect 300b, the first conductive interconnect 300a is electrically connected to the first heat-sensing microstructure 203a, and the second conductive interconnect 300b is electrically connected to the second heat-sensing microstructure 203b.

In this embodiment, a first isolation layer 301 is formed on the first conductive interconnection structure, and the first isolation layer 301 covers the first thermal sensing microstructure 203a, the second thermal sensing microstructure 203b, the first conductive interconnection line 300a and the second conductive interconnection line 300b to protect the first thermal sensing microstructure 203a and the second thermal sensing microstructure 203b and to achieve the necessary insulation isolation between adjacent conductive interconnection lines in adjacent first conductive interconnection structures.

In this embodiment, the first conductive interconnection structure is a single-layer structure, and at this time, the first conductive interconnection 300a and the second conductive interconnection 300b are both a metal wire, one end of the first conductive interconnection 300a is electrically connected to the first thermal-sensing microstructure 203a, the other end is electrically connected to the readout interconnection 104a in the readout circuit of the circuit substrate 10 through the second conductive interconnection 40a, one end of the second conductive interconnection 300b is electrically connected to the second thermal-sensing microstructure 203b, and the other end is electrically connected to the readout interconnection 104b in the readout circuit of the circuit substrate 10 through the second conductive interconnection 40b. Therefore, the integration thickness of the thermopile sensor is reduced, and the miniaturization of the device is facilitated. In other embodiments of the present invention, the first conductive interconnection structure may also be a multi-layer metal interconnection structure.

In this embodiment, a support layer 601 is formed on the first conductive interconnect structure. The depth of the first grooves 600 of the support layer 601 may be less than or equal to the thickness of the support layer 601. The supporting layer 601 is used to provide a basis for the subsequent formation of the first cavity 602, and on the other hand, the supporting layer 601 may also cover the first conductive interconnection line 300a and the second conductive interconnection line 300b and the thermopile structure, so as to avoid contamination or oxidation of the corresponding structures and to achieve the necessary insulation isolation between adjacent conductive interconnection lines in adjacent first conductive interconnection structures.

The circuit substrate 10 may include a second base 100 in which the circuit substrate 10 is formed, a device structure and

readout interconnection structures

104a, 104b electrically connected to the device structure, the

readout interconnection structures

104a, 104b being formed on the second base 100.

The second substrate 100 may be any suitable semiconductor substrate material known to those skilled in the art, such as silicon, silicon-on-insulator, germanium, silicon germanium, gallium arsenide, indium phosphide, etc. The second substrate 100 has formed therein corresponding device structures through a CMOS fabrication process and device isolation structures located between adjacent device structures, and the device structures may include at least one of MOS transistors, resistors, diodes, capacitors, memories, and the like.

read interconnect structures

104a, 104b may be electrically connected by bottom contact plugs that are in direct electrical contact with corresponding terminals of the device structure and a multi-layer metal interconnect structure that is electrically connected to the bottom contact plugs, thereby achieving electrical connection of the read interconnect structure to the device structure. Wherein an interlayer dielectric material layer 103 is further formed on the second substrate 100 so as to isolate adjacent metal interconnection layers. The interlayer dielectric material 103 may comprise at least one of silicon dioxide, silicon nitride, a low K dielectric having a dielectric constant K lower than silicon dioxide, a high K dielectric having a K higher than silicon dioxide, a metal nitride, and the like.

In this embodiment, the circuit substrate is configured with a readout circuit, the thermopile sensor further includes a second conductive interconnection structure disposed on the periphery of the thermal radiation sensing region, and the readout circuit is electrically connected to the first conductive interconnection structure through the second conductive interconnection structure. The second conductive interconnection structures 40A and 40b are rewiring structures formed by the same rewiring process and are located on the periphery of the thermal radiation sensing area 20A, so that the direct absorption of the second conductive interconnection structures to thermal radiation can be avoided while the electric connection between the reading circuit in the circuit substrate 10 and the thermopile structure in the thermopile structure plate 20 is realized, the overall vertical thickness of the thermopile sensor can be reduced, the miniaturization of the thermopile sensor is facilitated, and the performance reliability of the device is improved.

The second conductive interconnection structure comprises a first plug positioned in the thermopile structure plate, and the first plug is connected with the first conductive interconnection structure; a second plug penetrating through the thermopile structure plate and electrically connected to the readout circuit; and a plug interconnect on the thermopile structure plate, the plug interconnect connecting the first plug and the second plug.

Specifically, the second conductive interconnection structure 40a includes a second plug 401a, a first plug 403a and a plug interconnection line 402a, the second conductive interconnection structure 40b includes a second plug 401b, a first plug 403b and a plug interconnection line 402b, the

plug interconnection lines

402a, 402b are formed on a side of the thermopile structure plate 20 facing away from the first cavity 602, the

second plugs

401a, 401b are disposed in the thermopile structure plate 20, a bottom end of the second plug 401a is electrically connected to the first conductive interconnection line 300a, a top end is electrically connected to the interconnection line 402a, a bottom end of the second plug 401b is electrically connected to the second conductive interconnection line 300b, and a top end is electrically connected to the interconnection line 402b, the

first plugs

403a, 403b penetrate through the thermopile structure plate 20 and the first interconnection layer 30, a top end of the first plug 403a is electrically connected to the interconnection line 402a, and a bottom end is electrically connected to the readout interconnection structure 104a in the circuit substrate 10; the top end of the first plug 403b is electrically connected to the interconnect line 402b, and the bottom end is electrically connected to the readout interconnect structure 104b in the circuit substrate 10.

In addition, in this embodiment, since the thermopile structure plate 20 is formed on the basis of a semiconductor substrate, in order to avoid leakage between the

second plugs

401a and 401b and the

first plugs

403a and 403b and the thermopile structure plate 20, the sidewalls of the conductive materials in the

second plugs

401a and 401b and the

first plugs

403a and 403b are further surrounded by an insulating medium layer, and the material of the insulating medium layer includes at least one of silicon oxide, silicon nitride, silicon oxynitride, metal nitride, high-K dielectric, and low-K dielectric. In other embodiments of the present invention, when the thermopile structure plate 20 is formed based on a non-conductive material plate, the enclosure of the insulating medium layer may be omitted on the sidewalls of the conductive material in the

second plugs

401a, 401b and the

first plugs

403a, 403b.

In another embodiment of the present invention, as shown in fig. 14, the second conductive interconnection structure may include:

first plugs

403a, 403b, wherein the

first plugs

403a, 403b penetrate through the thermopile structure plate and the support layer, and the bottom ends of the first plugs are electrically connected with the readout circuit;

circuit substrate second sub-plugs 404a, 404b electrically connected to the readout circuitry;

thermopile second sub-plugs 406a, 406b electrically connected to the circuit substrate second sub-plugs 404a, 404b and to the first conductive interconnect structure.

In yet another embodiment of the present invention, as shown in fig. 17, the second conductive interconnection structure may further include:

circuit substrate first sub-plugs 405a, 405b electrically connected to the readout circuitry;

thermopile first sub-plugs 407a, 407b, which extend through the thermopile structure plate and the support layer;

the second thermopile sub-plugs 406a and 406b are electrically connected to the second

circuit substrate sub-plugs

404a and 404b, and the second thermopile sub-plugs 406a and 406b are electrically connected to the first conductive interconnection structure.

Of course, the sidewall of each plug may also be surrounded by an insulating dielectric layer to prevent leakage. For details, please refer to the foregoing description.

With reference to fig. 11, the thermopile sensor of this embodiment further includes a cover 50, the cover 50 is disposed on a side of the thermopile structure plate 20 facing away from the circuit substrate 10, the cover 50 is provided with a protection groove 503, the protection groove 503 of the cover 50 covers the thermal radiation sensing region 20A of the thermopile structure plate 20, and a radiation penetration window (not shown) is further provided on the cover of the side of the protection groove 503 facing away from the thermopile structure plate 20, and the radiation penetration window is at least vertically aligned with the thermopile structure.

The radiation transmission window is used for transmitting infrared rays. In one embodiment, an infrared antireflection film may be further disposed above the radiation transmission window.

The arrangement of the second cavity 502 can reduce the direct absorption of the incident thermal radiation by the upper layer structure as much as possible, and simultaneously store the incident thermal radiation to a certain extent, so that the incident radiation heat can be received by the thermopile structure to the maximum extent, and the performance of the thermopile sensor can be improved.

In an alternative embodiment, the cover 50 may include a third substrate 500 and a cavity wall 501 formed on a side of the third substrate 500 facing the thermopile structure plate 20, the cavity wall 501 and the dielectric layer 201 enclosing a second cavity 502. The material of the third substrate 500 may be any suitable material known to those skilled in the art, such as glass, plastic, semiconductor, etc. The material of the chamber wall 501 may be the same as the third substrate 500, or may be different from the material of the third substrate 500. A radiation penetration window (not shown) is further disposed on the cover 50 of the side of the second cavity 502 facing away from the thermopile structure plate 20, the radiation penetration window is at least vertically aligned with the thermopile structure, and the material of the radiation penetration window includes a semiconductor (e.g., silicon, germanium, silicon-on-insulator, etc.) and/or an organic filter material (e.g., polyethylene, polypropylene, etc.).

The thermopile sensor of this embodiment, set gradually the thermopile structural slab along the incident radiation direction, electrically conductive interconnection structure, supporting layer and circuit substrate, and press from both sides between circuit substrate and thermopile structural slab and establish first cavity, and increase thermal radiation reflecting plate and thermal radiation division board in the bottom of first cavity, moreover, the steam generator is simple in structure, both can receive the thermal radiation from one side of thermopile structural slab dorsad circuit substrate, avoid circuit substrate and first electrically conductive interconnection structure etc. to the direct absorption of thermal radiation, again can carry out thermal insulation through first cavity, prevent that the heat that the thermopile structure received from conducting in the circuit substrate of first cavity below, can also be through the residual radiation reflection backheat thermopile structural slab that the thermal radiation reflecting plate will pierce through the thermopile structural slab, thereby can improve the measurement accuracy of thermopile sensor. The thermal radiation isolation plate is formed below the thermal radiation reflection plate, and can isolate heat generated by the circuit substrate, so that the heat of the circuit substrate is prevented from being transferred to the thermopile structure plate, and the measurement precision of the thermopile sensor is improved; furthermore, as the circuit substrate is directly bonded below the thermopile structure plate, the vertical system integration of the CMOS reading circuit can be realized without increasing the area, which is beneficial to shortening the interconnection length of the sensing signal to the reading circuit, signal loss and noise, the miniaturization of the thermopile sensor and the further extension to the 3D system integration for manufacturing the active thermal imaging sensor array, the CMOS reading pixel array and the peripheral circuit; the loss of corresponding environment information can be further avoided, and the measurement precision of the sensor is improved; after the supporting layer is bonded with the circuit substrate subsequently, the first conductive interconnection structure is located below the thermopile structure, so that direct absorption of the first conductive interconnection structure on thermal radiation can be avoided, influence on a circuit substrate device is avoided, and signal stability is improved.

It should be noted that the thermopile sensor of the present invention is not limited to the specific structure examples in the above embodiments, and in other embodiments of the present invention, modifications and omissions are made to the corresponding structure in the thermopile sensor of the above embodiments on the premise of achieving the same function, and the obtained thermopile sensor also belongs to the protection scope of the technical solution of the present invention. The details of the thermopile sensor and the forming method thereof in this embodiment may be referred to each other, and are not repeated herein.

An embodiment of the present invention also provides an electronic device having the thermopile sensor of the present invention, whose performance is improved. The electronic device also has at least one lens and filter and associated electronic processor components. The electronic equipment can be temperature measuring equipment such as a forehead temperature gun, an ear temperature gun, a food temperature detecting instrument and the like, can also be a qualitative/quantitative analysis instrument of gas components, can also be intelligent household electrical appliance equipment, a lamp switch or medical equipment, and can also be a mobile terminal with a thermopile sensor, such as a mobile phone, a computer, a panel and the like, and has a temperature measuring function; in an embodiment, the electronic device is a thermal imager, and thermopile structures of the thermal imager are arranged in an array so as to realize thermal imaging of an object.

It will be apparent to those skilled in the art that various changes and modifications may be made in the invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims

1. A thermopile sensor, comprising, in order along the direction of incident radiation:

the thermoelectric stack structure plate is provided with a thermal radiation induction area, a thermoelectric stack structure is arranged in the thermal radiation induction area, and the thermoelectric stack structure plate comprises a first substrate, a dielectric layer and a semiconductor layer which are sequentially stacked from bottom to top;

the supporting layer is positioned on one side of the semiconductor layer of the thermopile structure plate;

a first cavity is defined among the circuit substrate, the thermopile structure plate and the supporting layer, the thermopile structure is arranged above the first cavity, and a heat radiation reflecting plate is arranged at the bottom of the first cavity;

the first isolation layer is positioned between the first cavity and the thermopile structure and used for covering the thermopile structure;

the sealing cover is arranged on one side, back to the circuit substrate, of the thermopile structure plate, the sealing cover is provided with a protection groove, and a radiation penetrating window is further arranged on the sealing cover on one side, back to the thermopile structure plate, of the protection groove; the protective groove of the cover covers the thermal radiation sensing area of the thermopile structure plate, and the radiation penetrating window is at least vertically aligned with the thermopile structure; further comprising:

a first conductive interconnect structure electrically connected to the thermopile structure, the first conductive interconnect structure disposed below the thermopile structure;

and the heat radiation isolation plate is positioned at the bottom of the first cavity and below the heat radiation reflection plate.

2. The thermopile sensor of claim 1, wherein the thermopile structure is formed in the semiconductor layer.

3. The thermopile sensor of claim 1, wherein the thermopile structure comprises at least one heat-sensing microstructure whose material comprises at least one of a metal, an undoped semiconductor, a doped semiconductor, and a metal silicide; the undoped semiconductor or the doped semiconductor material comprises at least one of silicon, germanium, gallium arsenide, or indium phosphide, and the doped semiconductor dopant comprises an N-type or P-type dopant.

4. The thermopile sensor of claim 1, wherein an upper surface of the thermal radiation reflecting plate is exposed to the first cavity.

5. The thermopile sensor of claim 1, further comprising:

a first passivation layer between the thermal radiation spacer and the thermal radiation reflecting plate.

6. The thermopile sensor of claim 1, further comprising:

a second passivation layer surrounding the thermal radiation reflecting plate and the thermal radiation spacer.

7. The thermopile sensor of claim 1, further comprising:

a third passivation layer covering at least the thermal radiation reflecting plate.

8. The thermopile sensor of claim 1, wherein a readout circuit is disposed in the circuit substrate, the thermopile sensor further including a second electrically conductive interconnect structure disposed at a periphery of the thermal radiation sensing region, the readout circuit being electrically connected to the first electrically conductive interconnect structure via the second electrically conductive interconnect structure.

9. The thermopile sensor of claim 8, wherein the second conductive interconnect structure includes a first plug located within the thermopile structure plate, the first plug connecting the first conductive interconnect structure;

10. The thermopile sensor of claim 8, wherein the second conductive interconnect structure comprises: the first plug penetrates through the thermopile structure plate and the supporting layer, and the bottom end of the first plug is electrically connected with the readout circuit;

the circuit substrate second sub-plug is electrically connected with the reading circuit;

and the second thermopile sub-plug is electrically connected with the second circuit substrate sub-plug and the first conductive interconnection structure.

11. The thermopile sensor of claim 8, wherein the second conductive interconnect structure includes:

the circuit substrate first sub plug is electrically connected with the reading circuit;

a thermopile first sub-plug extending through the thermopile structure plate and the support layer;

and the second thermopile sub-plug is electrically connected with the second circuit substrate sub-plug, and the second thermopile sub-plug is electrically connected with the first conductive interconnection structure.

12. Thermopile sensor according to any one of claims 1-11, characterized in that the vertical distance between the thermal radiation reflecting plate and the thermopile structure is an odd multiple of 1/4 of the wavelength of the radiation.

13. The thermopile sensor of any one of claims 1-11, wherein the material of the thermal radiation reflecting plate comprises an electrically conductive material comprising at least one of a metal, a metal silicide, an undoped semiconductor and a doped semiconductor, and/or a photonic crystal material.

14. Thermopile sensor according to any one of claims 1-11, in which the material of the thermal radiation isolation plate comprises a metallic material.

15. A method of making a thermopile sensor, comprising:

providing a thermopile structure plate, wherein the thermopile structure plate is provided with a heat radiation induction area, a thermopile structure is formed in the heat radiation induction area, and the thermopile structure plate comprises a first substrate, a dielectric layer and a semiconductor layer which are sequentially stacked from bottom to top;

forming a first isolation layer for covering the thermopile structure;

forming a support layer on one side of a semiconductor layer of the thermopile structure plate;

etching the support layer by taking the first isolation layer as an etching stop layer to form a first groove, wherein the first groove at least corresponds to the heat radiation sensing area;

bonding the circuit substrate and the supporting layer, enabling the first groove to be clamped between the thermopile structure plate and the circuit substrate to form a first cavity, enabling the first isolation layer to be located between the first cavity and the thermopile structure, and enabling the thermal radiation reflection plate to be located below the thermopile structure;

providing a cover having a protective slot;

bonding the cover to the thermopile structure plate, wherein a protection groove of the cover covers a thermal radiation sensing area of the thermopile structure plate, a radiation penetrating window is further arranged on the cover on one side of the protection groove, which faces away from the thermopile structure plate, and the radiation penetrating window is at least vertically aligned with the thermopile structure; a thermal radiation isolation plate is further formed on the circuit substrate and is positioned below the thermal radiation reflection plate;

before the step of forming the support layer on the thermopile structure plate, the method further comprises the following steps:

forming a first electrically conductive interconnect structure on the thermopile structure plate in electrical connection with the thermopile structure;

the step of forming a support layer on the thermopile structure plate includes:

forming a support layer on the first electrically conductive interconnect structure and the thermopile structure plate;

after the circuit substrate is bonded to the supporting layer, the first conductive interconnection structure, the thermal radiation reflection plate, and the thermal radiation isolation plate are all located below the thermopile structure.

16. The method of fabricating a thermopile sensor of claim 15, wherein the bottom surface of the thermal radiation reflecting plate is in contact with the top surface of the thermal radiation isolating plate.

17. The method of manufacturing a thermopile sensor according to claim 16, wherein the circuit substrate includes a heat radiation corresponding region corresponding to the heat radiation sensing region;

the step of forming a thermal radiation reflecting plate and a thermal radiation spacer on the circuit substrate includes:

forming an isolation material layer covering the circuit substrate;

forming a layer of reflective material overlying the layer of spacer material;

and removing the reflecting material layer and the isolating material layer outside the heat radiation corresponding region, taking the residual reflecting material layer as a heat radiation reflecting plate, and taking the residual isolating material layer as a heat radiation isolating plate.

18. The method of manufacturing a thermopile sensor according to claim 16, wherein the circuit substrate includes a heat radiation corresponding region corresponding to the heat radiation sensing region;

forming a dielectric layer on the circuit substrate, wherein the dielectric layer is provided with an opening, and the opening at least exposes the heat radiation corresponding area;

filling the opening to form the thermal radiation isolation plate;

the heat radiation reflecting plate is formed on the heat radiation shielding plate, and the heat radiation reflecting plate covers at least the heat radiation shielding plate.

19. The method of fabricating a thermopile sensor according to claim 15, wherein a first passivation layer is formed between the bottom surface of the thermal radiation reflecting plate and the top surface of the thermal radiation isolating plate.

20. The method for manufacturing a thermopile sensor according to claim 19, wherein the circuit substrate includes a heat radiation corresponding region corresponding to the heat radiation sensing region;

forming an isolation material layer covering the circuit substrate;

forming a layer of reflective material overlying the layer of spacer material;

and removing the reflecting material layer, the first passivation material layer and the isolation material layer outside the heat radiation corresponding region, taking the rest reflecting material layer as a heat radiation reflecting plate, taking the rest first passivation material layer as a first passivation layer and taking the rest isolation material layer as a heat radiation isolating plate.

21. The method for manufacturing a thermopile sensor according to claim 19, wherein the circuit substrate includes a heat radiation corresponding region corresponding to the heat radiation sensing region;

filling the opening to form the thermal radiation isolation plate;

forming a first passivation layer on the heat radiation spacer, the first passivation layer covering at least the heat radiation spacer;

forming the heat radiation reflection plate on the first passivation layer, the heat radiation reflection plate covering at least the heat radiation separation plate.

22. The method of fabricating a thermopile sensor according to claim 15, wherein after the forming of the thermal radiation reflecting plate and the thermal radiation isolating plate and before the bonding of the circuit substrate to the support layer, further comprising:

and forming a second passivation layer covering the circuit substrate exposed by the heat radiation reflection plate.

23. The method of fabricating a thermopile sensor according to claim 15, wherein after forming the thermal radiation reflecting plate and the thermal radiation isolating plate on the circuit substrate and before bonding the circuit substrate to the supporting layer, further comprising:

forming a third passivation layer covering at least the thermal radiation reflecting plate.

24. The method of any of claims 15-23, wherein the thermopile structure comprises at least one heat-sensing microstructure comprising a material comprising at least one of a metal, an undoped semiconductor, a doped semiconductor, and a metal silicide; the undoped semiconductor or the doped semiconductor material comprises at least one of silicon, germanium, gallium arsenide, or indium phosphide, and the doped semiconductor dopant comprises an N-type or P-type dopant.

25. The method of making a thermopile sensor of any one of claims 15-23, wherein the step of providing the thermopile structure plate comprises:

providing a first substrate, wherein a semiconductor layer is formed on the surface of the first substrate;

and carrying out N-type and/or P-type ion doping on partial region of the semiconductor layer to form an N-type doped region and/or a P-type doped region as the thermopile structure.

26. The method of fabricating a thermopile sensor of claim 25, wherein the first base is a silicon-on-insulator substrate and the semiconductor layer is a top layer single crystal silicon of the silicon-on-insulator substrate.

27. The method of fabricating a thermopile sensor of claim 25, further comprising, after bonding the circuit substrate to the support layer: and removing the first substrate.

28. The method of fabricating a thermopile sensor of any one of claims 15-23, wherein the vertical distance between the thermal radiation reflecting plate and the thermopile structure is an odd multiple of 1/4 of the wavelength of infrared radiation.

29. The method of fabricating a thermopile sensor according to any one of claims 15-23, wherein the material of the thermal radiation reflecting plate comprises an electrically conductive material comprising at least one of a metal, a metal silicide, an undoped semiconductor and a doped semiconductor and/or a photonic crystal material.

30. The method of fabricating a thermopile sensor of any one of claims 15-23, wherein the material of the thermal radiation shield includes a metallic material.

31. The method of fabricating a thermopile sensor according to any one of claims 15-23, wherein a readout circuit is formed in the circuit substrate, and wherein the step of forming the thermopile sensor before or after bonding the circuit substrate to the support layer further comprises:

forming a second conductive interconnection on the thermopile structure plate at the periphery of the thermal radiation sensing region, the second conductive interconnection electrically connecting the readout circuitry and the first conductive interconnection.

32. The method of fabricating a thermopile sensor of claim 31, wherein the second conductive interconnect structure comprises:

the first plug penetrates through the thermopile structure plate and the supporting layer, and the bottom end of the first plug is electrically connected with the readout circuit;

a second plug, a bottom end of the second plug being electrically connected to the first conductive interconnect structure;

and the plug interconnection line is positioned on the thermopile structure plate and is electrically connected with the first plug and the second plug.

33. The method of fabricating a thermopile sensor of claim 31, wherein the second conductive interconnect structure comprises:

the circuit substrate second sub plug is electrically connected with the reading circuit;

and the second thermopile sub-plug is electrically connected with the first conductive interconnection structure, and after the circuit substrate is bonded with the supporting layer, the second thermopile sub-plug is electrically connected with the second circuit substrate sub-plug.

34. The method of fabricating a thermopile sensor of claim 31, wherein the second conductive interconnect structure comprises:

a thermopile second sub-plug electrically connected with the first conductive interconnect structure;

and after the circuit substrate is bonded with the supporting layer, the second sub plug of the thermopile is electrically connected with the second sub plug of the circuit substrate, and the first sub plug of the thermopile is electrically connected with the first sub plug of the circuit substrate.

35. The method of fabricating a thermopile sensor of claim 31, further comprising, after forming the second conductive interconnect structure:

the protection groove is clamped between the cover and the thermopile structure plate to form a second cavity, and the second cavity is aligned with the first cavity; and trimming the cover to expose at least a portion of the surface of the second conductive interconnect structure.

36. An electronic device comprising a thermopile sensor of any one of claims 1-14.

37. The electronic device of claim 36, wherein the electronic device is a thermal imager having thermopile junctions arranged in an array.