CN108007580B - High-temperature heat flow sensor based on SiC thermoelectric material and preparation method thereof - Google Patents

High-temperature heat flow sensor based on SiC thermoelectric material and preparation method thereof Download PDF

Info

Publication number
CN108007580B
CN108007580B CN201711447533.4A CN201711447533A CN108007580B CN 108007580 B CN108007580 B CN 108007580B CN 201711447533 A CN201711447533 A CN 201711447533A CN 108007580 B CN108007580 B CN 108007580B
Authority
CN
China
Prior art keywords
sic
film
type
heat flow
flow sensor
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201711447533.4A
Other languages
Chinese (zh)
Other versions
CN108007580A (en
Inventor
李铁
田伟
王跃林
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shanghai Institute of Microsystem and Information Technology of CAS
Original Assignee
Shanghai Institute of Microsystem and Information Technology of CAS
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Shanghai Institute of Microsystem and Information Technology of CAS filed Critical Shanghai Institute of Microsystem and Information Technology of CAS
Priority to CN201711447533.4A priority Critical patent/CN108007580B/en
Publication of CN108007580A publication Critical patent/CN108007580A/en
Application granted granted Critical
Publication of CN108007580B publication Critical patent/CN108007580B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J5/00—Radiation pyrometry, e.g. infrared or optical thermometry
    • G01J5/10—Radiation pyrometry, e.g. infrared or optical thermometry using electric radiation detectors
    • G01J5/12—Radiation pyrometry, e.g. infrared or optical thermometry using electric radiation detectors using thermoelectric elements, e.g. thermocouples
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N10/00—Thermoelectric devices comprising a junction of dissimilar materials, i.e. devices exhibiting Seebeck or Peltier effects
    • H10N10/01—Manufacture or treatment
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N10/00—Thermoelectric devices comprising a junction of dissimilar materials, i.e. devices exhibiting Seebeck or Peltier effects
    • H10N10/10—Thermoelectric devices comprising a junction of dissimilar materials, i.e. devices exhibiting Seebeck or Peltier effects operating with only the Peltier or Seebeck effects
    • H10N10/17—Thermoelectric devices comprising a junction of dissimilar materials, i.e. devices exhibiting Seebeck or Peltier effects operating with only the Peltier or Seebeck effects characterised by the structure or configuration of the cell or thermocouple forming the device

Abstract

The invention provides a high-temperature heat flow sensor based on a SiC thermoelectric material and a preparation method thereof, wherein the high-temperature heat flow sensor comprises the following steps: the SiC substrate is provided with a first surface and a second surface, and the first surface is provided with a groove and a platform area formed by the groove in a surrounding mode; the composite dielectric film covers the groove and the platform area; the heat insulation cavity is arranged in the SiC substrate, is inwards recessed from the second surface and is positioned below a part of the composite dielectric film in the platform region; the P-type SiC film resistance block and the N-type SiC film resistance block are positioned on the composite dielectric film of the platform area and are locally positioned above the heat insulation cavity; the insulating medium layer covers the P-type SiC film resistance block, the N-type SiC film resistance block and the composite medium film; and the metal pattern layer is formed on the insulating medium layer, comprises an electrode and a lead, and connects the P-type SiC film resistance block and the N-type SiC film resistance block to form a thermopile. According to the invention, the monocrystal SiC with excellent high-temperature performance is used as the thermoelectric material, so that the heat flux density in a high-temperature severe environment can be rapidly and accurately measured.

Description

High-temperature heat flow sensor based on SiC thermoelectric material and preparation method thereof
Technical Field
The invention belongs to the technical field of heat flow detection, and particularly relates to a high-temperature heat flow sensor based on a SiC thermoelectric material and a preparation method thereof.
Background
In nature and production processes, there are a number of heat transfer problems. With the development of modern science and technology, the temperature is far from enough as the only information of heat transfer. Therefore, heat flow detection theory and technology are increasingly emphasized, and corresponding heat flow sensors are greatly developed and widely applied.
Although the existing heat flow sensor can meet the general measurement requirements of heat flow density in industrial and agricultural production and daily life, the heat-resistant temperature and the measurement range of the existing heat flow sensor are generally low, and the heat-resistant temperature and the measurement range are usually 1000 ℃ and 1MW/m2The size is larger, the response time is longer, and the fastest speed is only in the order of ms. Therefore, in a severe environment with ultrahigh temperature and high heat flow, such as an aviation engine and an aerospace engine, the existing heat flow sensor is difficult to realize quick and accurate measurement.
The thermopile type heat flow device manufactured by adopting the MEMS technology has the advantages of small volume, simple structure, high response speed and the like which are unique, but the thermopile type heat flow device has the difficult problems of ultrahigh working temperature and large heat flow, and the selection of materials is particularly important. SiC is used as a wide band gap semiconductor, has high melting point, high thermal conductivity, high carrier mobility and high breakdown voltage, and is an ideal material of a high-temperature sensing device. High temperature micro-heaters and flow sensors based on SiC have been developed, but high temperature heat flow sensors based on SiC have not been reported.
The 4H-SiC monocrystal film material is a material with higher SiC intermediate melting point and higher thermal conductivity, and the characteristics of good high-temperature stability and high thermal conductivity of a large heat flow device manufactured by adopting the 4H-SiC thermoelectric material can be fully utilized, so that the rapid heating and cooling are realized while the thermal stability is improved, and the application of the large heat flow device in an ultrahigh-temperature environment becomes possible.
Therefore, whether from the industrial production demand or the technology development trend, the development of a high-temperature heat flow sensor based on the SiC thermoelectric material with quick response and stable performance has important significance.
Disclosure of Invention
In view of the above prior art, the present invention aims to provide a high temperature heat flow sensor based on SiC thermoelectric material and a preparation method thereof, which are used for realizing rapid and accurate measurement of heat flow density in high temperature severe environments such as aerospace, metallurgy, and the like.
To achieve the above and other related objects, the present invention provides a high temperature heat flow sensor based on SiC thermoelectric material, comprising:
the SiC substrate is provided with a first surface and a second surface, and a groove and a platform region formed by the groove are arranged on the first surface;
the composite dielectric film is positioned on the first surface of the SiC substrate and covers the surface of the groove and the surface of the platform region;
the heat insulation cavity is arranged in the SiC substrate, is inwards recessed from the second surface of the SiC substrate and is positioned below part of the composite dielectric film in the platform region;
the P-type SiC film resistance block and the N-type SiC film resistance block are positioned on the composite dielectric film at the platform region and are locally positioned above the heat insulation cavity;
the insulating medium layer covers the P-type SiC film resistance block, the N-type SiC film resistance block and the composite medium film;
and the metal pattern layer is formed on the insulating medium layer and comprises an electrode and a lead so as to connect the P-type SiC film resistance block and the N-type SiC film resistance block to form a thermopile.
Optionally, the material of the SiC substrate is selected from one of 4H-SiC, 6H-SiC and 3C-SiC.
Optionally, the depth of the trench is 1-50 μm.
Optionally, the composite dielectric film is formed by compounding a single layer or multiple layers of silicon oxide and silicon nitride, and the thickness of the composite dielectric film is 1-10 μm.
Optionally, the heat insulation cavity penetrates through the SiC substrate to expose a part of the composite dielectric film; the insulating cavity has a rectangular cross-section.
Optionally, the material of the P-type SiC thin film resistor block and the N-type SiC thin film resistor block is selected from one of 4H-SiC, 6H-SiC and 3C-SiC; the thicknesses of the P-type SiC film resistance block and the N-type SiC film resistance block are less than 1 mu m, and the thickness deviation is not more than 3%.
Optionally, the material of the insulating dielectric layer includes one or both of silicon oxide and silicon nitride.
Optionally, the material of the metal pattern layer is selected from one or more of titanium, tungsten and platinum.
In order to achieve the above objects and other related objects, the present invention further provides a method for preparing a high temperature heat flow sensor based on SiC thermoelectric material, comprising the steps of:
1) providing a SiC substrate with a first surface and a second surface, and etching a groove on the first surface to form a platform region surrounded by the groove;
2) forming a composite dielectric film on the first surface, wherein the composite dielectric film covers the surface of the groove and the surface of the platform area;
3) forming a P-type SiC film resistance block and an N-type SiC film resistance block on the surface of the composite dielectric film in the platform region;
4) forming an insulating medium layer on the surfaces of the P-type SiC film resistor block and the N-type SiC film resistor block, and forming a lead hole on the insulating medium layer to expose part of the P-type SiC film resistor block and the N-type SiC film resistor block;
5) forming metal pattern layers comprising electrodes and leads on the surfaces of the insulating medium layer and the lead holes so as to connect the P-type SiC film resistor block and the N-type SiC film resistor block into a thermopile;
6) and etching the second surface of the SiC substrate to form a heat insulation cavity, wherein the heat insulation cavity is positioned below part of the composite medium film in the platform region, and the P-type SiC film resistance block and the N-type SiC film resistance block are partially positioned above the heat insulation cavity.
Optionally, in step 1), the material of the SiC substrate is selected from one of 4H-SiC, 6H-SiC and 3C-SiC.
Optionally, in step 1), forming the trench by photoetching a window by using inductively coupled plasma etching (ICP); the depth of the groove is 1-50 μm.
Optionally, in the step 2), forming the composite dielectric film by one or two methods of thermal oxidation and Low Pressure Chemical Vapor Deposition (LPCVD); the composite dielectric film is formed by compounding single-layer or multi-layer silicon oxide and silicon nitride, and the thickness of the composite dielectric film is 1-10 mu m.
Optionally, in step 3), the method for forming the P-type SiC thin film resistor block and the N-type SiC thin film resistor block includes the following steps:
transferring a SiC film on the surface of the composite dielectric film;
carrying out P-type doping and N-type doping on the SiC film by using photoresist as a mask layer;
patterning the SiC film;
and annealing the graphical SiC film to form a P-type SiC film resistance block and an N-type SiC film resistance block.
Further optionally, transferring the SiC film by using an ion beam stripping and substrate transferring method; the SiC film is made of one material selected from 4H-SiC, 6H-SiC and 3C-SiC; the thickness of the SiC film is less than 1 mu m, and the thickness deviation is not more than 3%.
Further optionally, performing P-type doping and N-type doping on the SiC film by using an ion implantation method; and patterning the SiC film by adopting inductively coupled plasma etching (ICP).
Optionally, in step 4), forming the insulating dielectric layer by using Plasma Enhanced Chemical Vapor Deposition (PECVD); the insulating medium layer comprises one or two of silicon oxide and silicon nitride.
Optionally, in step 5), a lift-off process (lift-of) or an electroplating process is used to form the metal layer; the material of the metal coating is selected from one or more of titanium, tungsten and gold.
Optionally, step 5) connects the P-type SiC thin film resistance block and the N-type SiC thin film resistance block into a thermopile structure formed by connecting 1 thermocouple or a plurality of thermocouples in series.
Optionally, in step 6), forming the heat insulation cavity by using inductively coupled plasma etching (ICP) to expose the composite dielectric film; the insulating cavity has a rectangular cross-section.
As described above, the high-temperature heat flow sensor based on the SiC thermoelectric material and the preparation method thereof of the present invention have the following beneficial effects:
1. the invention adopts MEMS technology to manufacture heat flow devices, has the advantages of small volume, high response speed and the like, is unique, adopts a simple thermopile sensitive structure, has simple preparation process and strong controllability, and has good compatibility with the existing mature semiconductor process;
2. the invention reduces the temperature of the preparation process of the material by the ion beam stripping and transferring technology, is convenient to realize the preparation of the SiC single crystal film, and simultaneously has the following two advantages: 1) the ion implanted lift-off transferred film has the single crystal quality of the SiC bulk material; 2) the SiC monocrystal can be used for circularly stripping the film, so that the material cost is reduced;
3. according to the invention, single crystal SiC with excellent high-temperature performance is used as a thermoelectric material to manufacture the P-SiC/N-SiC thermopile, and a low-stress supporting film is established by utilizing a semiconductor process under the condition of meeting high-temperature stability, so that the heat capacity of a device is reduced, the response time of the device is reduced, and the temperature difference between the hot end and the cold end of the thermopile is increased, thereby being beneficial to realizing the rapid and accurate measurement of the heat flux density in a high-temperature large-heat-flux environment.
Drawings
Fig. 1 shows a schematic cross-sectional structure diagram of a high-temperature heat flow sensor based on a SiC thermoelectric material according to an embodiment of the present invention.
Fig. 2a-2b are schematic perspective views illustrating a high-temperature heat flow sensor based on a SiC thermoelectric material according to an embodiment of the present invention, wherein fig. 2b is a schematic layered view of fig. 2 a.
Fig. 3a-3b are schematic perspective views illustrating another high-temperature heat flow sensor based on SiC thermoelectric material according to an embodiment of the present invention, wherein fig. 3b is a schematic layered view of fig. 3 a.
Fig. 4 shows a flowchart of a method for manufacturing a high-temperature heat flow sensor based on a SiC thermoelectric material according to an embodiment of the present invention.
Fig. 5a to 5f are schematic diagrams illustrating a manufacturing process of a high-temperature heat flow sensor based on a SiC thermoelectric material according to an embodiment of the present invention.
Description of the element reference numerals
10 SiC substrate
101 groove
102 platform area
103 heat insulation cavity
20 composite dielectric film
30 SiC film resistor block
301P type SiC film resistor block
302N type SiC film resistance block
40 insulating dielectric layer
401 lead hole
50 metal pattern layer
S1-S6
Detailed Description
The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention. It is to be noted that the features in the following embodiments and examples may be combined with each other without conflict.
It should be noted that the drawings provided in the following embodiments are only for illustrating the basic idea of the present invention, and the components related to the present invention are only shown in the drawings rather than drawn according to the number, shape and size of the components in actual implementation, and the type, quantity and proportion of the components in actual implementation may be changed freely, and the layout of the components may be more complicated.
Referring to fig. 1, the present embodiment provides a high temperature heat flow sensor based on SiC thermoelectric material, including: the SiC resistance block comprises a SiC substrate 10, a composite dielectric film 20, a heat insulation cavity 103, a SiC film resistance block 30, an insulating dielectric layer 40 and a metal pattern layer 50.
The SiC substrate 10 has a first surface on which a trench 101 and a mesa region 102 formed by the trench 101 are provided, and a second surface; the composite dielectric film 20 is positioned on the first surface of the SiC substrate 10, and covers the surface of the trench 101 and the surface of the mesa region 102; the heat insulation cavity 103 is arranged in the SiC substrate 10, is recessed inwards from the second surface of the SiC substrate 10, and is located below a part of the composite dielectric film 20 of the platform region 102; the SiC thin film resistor block 30 comprises a P-type SiC thin film resistor block 301 and an N-type SiC thin film resistor block 302 which are used as thermopile galvanic couple materials; the SiC film resistor block 30 is located on the composite dielectric film 20 at the platform region 102, and is locally located above the heat insulation cavity 103; the insulating medium layer 40 covers the surfaces of the SiC thin film resistor block 30 and the composite dielectric film 20; the metal pattern layer 50 is formed on the insulating dielectric layer 40, and includes an electrode and a lead wire to connect the P-type SiC thin film resistor block 301 and the N-type SiC thin film resistor block 302 to form a thermopile.
Specifically, the material of the SiC substrate 10 includes but is not limited to one of 4H-SiC, 6H-SiC, and 3C-SiC, and in the present embodiment, the material of the SiC substrate 10 is 4H-SiC.
Specifically, the depth of the trench 101 may be 1-50 μm, and in this embodiment, the depth of the trench 101 is 10 μm.
Specifically, the composite dielectric film 20 may be formed by compounding a single layer or multiple layers of low stress silicon oxide and silicon nitride, and the thickness may be 1-10 μm. In this embodiment, the composite dielectric film 20 is formed by compositing four layers of films, i.e., low-stress silicon oxide/silicon nitride/silicon oxide/silicon nitride, and the thickness is 3.2 μm.
Specifically, the SiC thin film resistor block 30 is made of one of 4H-SiC, 6H-SiC and 3C-SiC, but the thickness of the block is less than 1 μm, and the thickness deviation does not exceed 3%. In this embodiment, the SiC thin film resistor block 30 is made of a 4H — SiC thin film material having a thickness of 0.8 μm.
Specifically, the material of the insulating dielectric layer 40 includes one or two of silicon oxide and silicon nitride. In the present embodiment, the insulating dielectric layer 40 is made of silicon nitride with a thickness of 0.1 μm.
Specifically, the material of the metal layer 50 is selected from metals having good conductivity and a high melting point, including but not limited to one or more of titanium, tungsten, and platinum. In this embodiment, the metal layer 50 is made of titanium tungsten.
As a preferable solution of this embodiment, the thermal insulation cavity 103 may penetrate through the SiC substrate 10 to expose a portion of the composite dielectric film 20, so as to form a suspended film sensitive structure. In particular, the insulating cavity 103 may have a rectangular cross-section. In this embodiment, the insulating cavity 103 is a cylinder.
The P-type SiC thin film resistance block 301 and the N-type SiC thin film resistance block 302 are connected by metal leads to form a P-SiC/N-SiC thermocouple, a plurality of P-SiC/N-SiC thermocouples are connected in series to form a P-SiC/N-SiC thermopile structure, the number of the P-SiC/N-SiC thermocouples is at least 1, and in this embodiment, the number of the P-SiC/N-SiC thermocouples is 2 or 5.
Fig. 2a to 2b and fig. 3a to 3b respectively show the three-dimensional structures of two high-temperature heat flow sensors based on SiC thermoelectric materials, which are provided by the present embodiment and have different numbers of thermocouples.
The high-temperature heat flow sensor based on the SiC thermoelectric material shown in FIGS. 2a-2b comprises a SiC substrate 10, a composite dielectric film 20 on the SiC substrate 10, and two thermocouples formed by connecting 4 SiC thin film resistor blocks 30, wherein the two thermocouples are connected in series to form a thermopile structure. The 4 SiC thin-film resistor blocks 30 are disposed above the mesa region 102 of the SiC substrate 10, are uniformly distributed, and are connected by a lead 501, and the electrode 502 is disposed in the trench 101 (for easy understanding, the insulating dielectric layer is omitted in the drawing). The outer contour of the land area 102 takes a rectangular shape. The heat insulation cavity 103 is a cylinder and is arranged in the center of the platform region 102, so that the SiC thin film resistor block 30 is partially located above the heat insulation cavity 103.
The high-temperature heat flow sensor based on the SiC thermoelectric material shown in FIGS. 3a-3b comprises five thermocouples formed by connecting 10 SiC thin film resistor blocks 30 (i.e. 5P-type SiC thin film resistor blocks 301 and 5N-type SiC thin film resistor blocks 302), and the five thermocouples are connected in series to form a thermopile structure. The 10 SiC thin film resistor blocks 30 are disposed above the mesa region 102 of the SiC substrate 10, are uniformly distributed, and are connected by a lead 501, and the electrode 502 is disposed in the trench 101 (for easy understanding, the insulating dielectric layer is not shown in the figure). The outer contour of the land area 102 takes a circular shape. The heat insulation cavity 103 is a cylinder and is arranged in the center of the platform region 102, so that the SiC thin film resistor block 30 is partially located above the heat insulation cavity 103.
The working principle of the high-temperature heat flow sensor based on the SiC thermoelectric material is as follows: the suspended sensitive surface of the composite dielectric film 20 absorbs heat, and the heat rapidly flows along the radius direction of the composite dielectric film to form a temperature gradient. The center of the suspended sensitive surface is set as the hot pole of the thermopile, and the SiC substrate 10 is regarded as the cold pole of the thermopile, so that the intensity of incident heat flow can be directly measured through the magnitude of the output potential of the thermopile. In order to improve the heat absorption rate of the sensitive surface and ensure the sensitivity of an output signal, a black absorbing material can be coated on the surface of the sensitive surface, and the effects of fully absorbing heat and improving strength can be achieved.
In addition, the embodiment also provides a preparation method of the high-temperature heat flow sensor based on the SiC thermoelectric material, as shown in fig. 4, including the following steps:
s1, providing a SiC substrate with a first surface and a second surface, and etching a groove on the first surface to form a platform region surrounded by the groove;
s2, forming a composite dielectric film on the first surface, wherein the composite dielectric film covers the surface of the groove and the surface of the platform area;
s3, forming a P-type SiC film resistance block and an N-type SiC film resistance block on the surface of the composite dielectric film in the platform region;
s4, forming an insulating medium layer on the surfaces of the P-type SiC thin film resistor block and the N-type SiC thin film resistor block, and forming a lead hole on the insulating medium layer to expose part of the P-type SiC thin film resistor block and the N-type SiC thin film resistor block;
s5, forming metal pattern layers including electrodes and leads on the surfaces of the insulating medium layer and the lead holes so as to connect the P-type SiC film resistor block and the N-type SiC film resistor block into a thermopile;
and S6, etching the second surface of the SiC substrate to form a heat insulation cavity, wherein the heat insulation cavity is positioned below part of the composite dielectric film in the platform area, and the P-type SiC film resistance block and the N-type SiC film resistance block are partially positioned above the heat insulation cavity.
The above preparation method is further described in detail with reference to FIGS. 5a to 5 f.
First, as shown in fig. 5a, step S1 is executed to provide a SiC substrate 10 having a first surface and a second surface (i.e., a front surface and a back surface), form an etching window on the first surface (front surface) of the substrate 10 by using a photolithography process, etch the SiC substrate 10 through the etching window to form a trench 101 with a predetermined depth, and a mesa region 102 surrounded by the trench 101.
Specifically, the material of the SiC substrate 10 includes but is not limited to one of 4H-SiC, 6H-SiC, and 3C-SiC, and in the present embodiment, the material of the SiC substrate 10 is 4H-SiC.
Specifically, the etching window includes, but is not limited to, one of a rectangle and a circle, and the outer contour of the mesa region 102 includes, but is not limited to, one of a rectangle and a circle; in the present embodiment, the outer contour of the resulting land area 102 is rectangular (as shown in FIGS. 2a-2 b) or circular (as shown in FIGS. 3a-3 b).
Specifically, the trench 101 may be formed by using inductively coupled plasma etching (ICP), where the depth of the trench 101 is 1-50 μm, and in this embodiment, the depth of the trench 2 is 10 μm.
Then, as shown in fig. 5b, step S2 is performed to deposit a composite dielectric film 20 on the surface of the SiC substrate 10 where the trench 101 is formed, where the composite dielectric film 20 covers the surface of the trench 101 and the surface of the mesa region 102. The composite dielectric film 20 can be formed by compounding single-layer or multi-layer silicon oxide and silicon nitride, and the thickness is 1-10 μm; in the present embodiment, the composite dielectric film 20 is formed by compositing four layers of low stress silicon oxide/silicon nitride/silicon oxide/silicon nitride, and the thickness is 3.2 μm. The composite dielectric film 20 may be formed by thermal oxidation, Low Pressure Chemical Vapor Deposition (LPCVD), or the like.
Next, as shown in fig. 5c, step S3 is executed to form SiC thin film resistor blocks 30, including P-type SiC thin film resistor block 301 and N-type SiC thin film resistor block 302, as thermopile galvanic material on the surface of the composite dielectric film 20.
As a preferable aspect of this embodiment, the forming of the P-type SiC thin film resistance block 301 and the N-type SiC thin film resistance block 302 may specifically include the following steps:
firstly transferring a SiC film on the surface of the composite dielectric film 20, sequentially forming a first window and a second window on the surface of the SiC film through a photoetching process, doping the SiC film in a P type and an N type by using photoresist as a mask layer, patterning the SiC film, and annealing to form a P type SiC film resistance block 301 and an N type SiC film resistance block 302.
The SiC film can be doped by adopting an ion implantation method; patterning the SiC film by adopting inductively coupled plasma etching (ICP); and transferring the SiC film by adopting an ion beam stripping and substrate transferring method. The SiC film is made of one of 4H-SiC, 6H-SiC and 3C-SiC, the thickness is less than 1 μm, and the thickness deviation is not more than 3%; in this example, 4H-SiC having a thickness of 0.8 μm was used as the SiC thin film.
It should be noted that the physical nature of the ion beam stripping and substrate transfer is to form bubbles and holes rich in implanted ions at a specific depth of the SiC single crystal by light element ion implantation such as H, and to form a stripping defect layer. During the heating, the expansion action of the injected gas separates the surface SiC film from the single crystal substrate, and the detached SiC film is transferred onto the SiC substrate by wafer bonding.
The ion beam stripping and substrate transfer technology can reduce the temperature of the preparation process of the material, so that the preparation of the SiC film is convenient to realize, meanwhile, the film formed by the method has the single crystal quality of the SiC material, and the SiC single crystal can be circularly stripped to reduce the material cost.
Next, as shown in fig. 5d, step S4 is performed to form an insulating dielectric layer 40 on the surface of the SiC thin film resistor block 30, and the insulating dielectric layer 40 is etched by photolithography to expose a portion of the SiC thin film resistor block 30, so as to form a lead hole 401. Specifically, the insulating dielectric layer 40 may be formed by Plasma Enhanced Chemical Vapor Deposition (PECVD), and the insulating dielectric layer 40 includes one or two of silicon oxide and silicon nitride; in the present embodiment, the insulating dielectric layer 40 is made of silicon nitride with a thickness of 0.1 μm.
Then, as shown in fig. 5e, step S5 is performed to deposit and pattern a layer of metal on the surfaces of the insulating dielectric layer 40 and the lead holes 401, so as to form the leads 501 and the electrodes 502 between the SiC thin-film resistor blocks 30, i.e., the metal layer 50. The lead 501 connects the P-type SiC thin film resistance block and the N-type SiC thin film resistance block into 1 thermocouple or a plurality of thermocouples; the thermocouples are connected in series to form a thermopile structure, and in the embodiment, the number of the P-SiC/N-SiC thermocouples is 2 or 5.
Specifically, the metal may be formed and patterned by a lift-off process or an electroplating process, and the metal needs to have both good conductivity and a higher melting point, including but not limited to one or more of titanium, tungsten, and platinum; in this embodiment, the metal is formed and patterned by a lift-off process, and the metal is titanium tungsten.
Specifically, the stripping process comprises the following steps: spraying and photoetching glue to define the patterns of the metal lead 501 and the electrode 502, wherein the thickness of the photoresist is 1-10 mu m; sputtering titanium tungsten with the thickness of 0.2-2 mu m; and ultrasonically removing the photoresist by using acetone.
Finally, as shown in fig. 5f, step S6 is executed, a release window is formed on the back surface of the SiC substrate 10, the SiC substrate 103 is etched from the back surface through the release window, and the thermal insulation cavity 103 is obtained by release, so that the preparation of the SiC high-temperature heat flow sensor is completed.
Specifically, the heat insulation cavity 103 is released by adopting inductively coupled plasma etching (ICP), the heat insulation cavity 103 penetrates through the SiC substrate 10, the composite dielectric film 20 is exposed, and a suspended film sensitive structure is formed and has a rectangular cross section; in this embodiment, the insulating cavity 103 is a cylinder.
In conclusion, the SiC thermoelectric material-based high-temperature heat flow sensor and the preparation method thereof adopt the MEMS technology to manufacture the heat flow device, have the advantages of small volume, high response speed and the like, are unique, adopt a simple thermopile sensitive structure, have simple preparation process and strong controllability, and have good compatibility with the existing mature semiconductor process; the preparation process temperature of the material is reduced by the ion beam stripping and transferring technology, the preparation of the SiC single crystal film is conveniently realized, and meanwhile, the method has the following two advantages: 1) the ion implanted lift-off transferred film has the single crystal quality of the SiC bulk material; 2) the SiC monocrystal can be used for circularly stripping the film, so that the material cost is reduced; according to the invention, single crystal SiC with excellent high-temperature performance is used as a thermoelectric material to manufacture the P-SiC/N-SiC thermopile, and a low-stress supporting film is established by utilizing a semiconductor process under the condition of meeting high-temperature stability, so that the heat capacity of a device is reduced, the response time of the device is reduced, and the temperature difference between the hot end and the cold end of the thermopile is increased, thereby being beneficial to realizing the rapid and accurate measurement of the heat flux density in a high-temperature large-heat-flux environment.
Therefore, the invention effectively overcomes various defects in the prior art and has high industrial utilization value.
The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.

Claims (19)

1. A high temperature heat flow sensor based on SiC thermoelectric materials, comprising:
the SiC substrate is provided with a first surface and a second surface, and a groove and a platform region formed by the groove are arranged on the first surface;
the composite dielectric film is positioned on the first surface of the SiC substrate and covers the surface of the groove and the surface of the platform region;
the heat insulation cavity is arranged in the SiC substrate, is inwards recessed from the second surface of the SiC substrate and is positioned below part of the composite dielectric film in the platform region;
the P-type SiC film resistance block and the N-type SiC film resistance block are positioned on the composite dielectric film at the platform region and are locally positioned above the heat insulation cavity;
the insulating medium layer covers the P-type SiC film resistance block, the N-type SiC film resistance block and the composite medium film;
the lead wire hole is formed in the insulating medium layer so as to expose part of the P-type SiC thin film resistor block and the N-type SiC thin film resistor block;
and the metal pattern layer is formed on the insulating medium layer and on the surface of the lead hole, comprises an electrode and a lead and is used for connecting the P-type SiC film resistor block and the N-type SiC film resistor block to form a thermopile.
2. The SiC thermoelectric material-based high temperature heat flow sensor of claim 1, wherein: the material of the SiC substrate is selected from one of 4H-SiC, 6H-SiC and 3C-SiC.
3. The SiC thermoelectric material-based high temperature heat flow sensor of claim 1, wherein: the depth of the groove is 1-50 μm.
4. The SiC thermoelectric material-based high temperature heat flow sensor of claim 1, wherein: the composite dielectric film is formed by compounding single-layer or multi-layer silicon oxide and silicon nitride, and the thickness of the composite dielectric film is 1-10 mu m.
5. The SiC thermoelectric material-based high temperature heat flow sensor of claim 1, wherein: the heat insulation cavity penetrates through the SiC substrate to expose part of the composite dielectric film; the insulating cavity has a rectangular cross-section.
6. The SiC thermoelectric material-based high temperature heat flow sensor of claim 1, wherein: the material of the P-type SiC film resistor block and the N-type SiC film resistor block is selected from one of 4H-SiC, 6H-SiC and 3C-SiC; the thicknesses of the P-type SiC film resistance block and the N-type SiC film resistance block are less than 1 mu m, and the thickness deviation is not more than 3%.
7. The SiC thermoelectric material-based high temperature heat flow sensor of claim 1, wherein: the material of the insulating medium layer comprises one or two of silicon oxide and silicon nitride.
8. The SiC thermoelectric material-based high temperature heat flow sensor of claim 1, wherein: the material of the metal coating is selected from one or more of titanium, tungsten and platinum.
9. A preparation method of a high-temperature heat flow sensor based on a SiC thermoelectric material is characterized by comprising the following steps:
1) providing a SiC substrate with a first surface and a second surface, and etching a groove on the first surface to form a platform region surrounded by the groove;
2) forming a composite dielectric film on the first surface, wherein the composite dielectric film covers the surface of the groove and the surface of the platform area;
3) forming a P-type SiC film resistance block and an N-type SiC film resistance block on the surface of the composite dielectric film in the platform region;
4) forming an insulating medium layer on the surfaces of the P-type SiC film resistor block and the N-type SiC film resistor block, and forming a lead hole on the insulating medium layer to expose part of the P-type SiC film resistor block and the N-type SiC film resistor block;
5) forming metal pattern layers comprising electrodes and leads on the surfaces of the insulating medium layer and the lead holes so as to connect the P-type SiC film resistor block and the N-type SiC film resistor block into a thermopile;
6) and etching the second surface of the SiC substrate to form a heat insulation cavity, wherein the heat insulation cavity is positioned below part of the composite medium film in the platform region, and the P-type SiC film resistance block and the N-type SiC film resistance block are partially positioned above the heat insulation cavity.
10. The method for preparing a high temperature heat flow sensor based on SiC thermoelectric material as claimed in claim 9, wherein: in the step 1), the material of the SiC substrate is selected from one of 4H-SiC, 6H-SiC and 3C-SiC.
11. The method for preparing a high temperature heat flow sensor based on SiC thermoelectric material as claimed in claim 9, wherein: in the step 1), forming the groove by etching a photoetching window by adopting inductive coupling plasma; the depth of the groove is 1-50 μm.
12. The method for preparing a high temperature heat flow sensor based on SiC thermoelectric material as claimed in claim 9, wherein: in the step 2), forming the composite dielectric film by one or two methods of thermal oxidation and low-pressure chemical vapor deposition; the composite dielectric film is formed by compounding single-layer or multi-layer silicon oxide and silicon nitride, and the thickness of the composite dielectric film is 1-10 mu m.
13. The method for preparing a high temperature heat flow sensor based on SiC thermoelectric material as claimed in claim 9, wherein: in step 3), the method for forming the P-type SiC thin film resistor block and the N-type SiC thin film resistor block includes the following steps:
transferring a SiC film on the surface of the composite dielectric film;
carrying out P-type doping and N-type doping on the SiC film by using photoresist as a mask layer;
patterning the SiC film;
and annealing the graphical SiC film to form a P-type SiC film resistance block and an N-type SiC film resistance block.
14. The method of claim 13, wherein the sensor comprises: transferring the SiC film by adopting an ion beam stripping and substrate transferring method; the SiC film is made of one material selected from 4H-SiC, 6H-SiC and 3C-SiC; the thickness of the SiC film is less than 1 mu m, and the thickness deviation is not more than 3%.
15. The method of claim 13, wherein the sensor comprises: carrying out P-type doping and N-type doping on the SiC film by adopting an ion implantation method; and patterning the SiC film by adopting inductive coupling plasma etching.
16. The method for preparing a high temperature heat flow sensor based on SiC thermoelectric material as claimed in claim 9, wherein: in the step 4), forming the insulating medium layer by adopting plasma enhanced chemical vapor deposition; the insulating medium layer comprises one or two of silicon oxide and silicon nitride.
17. The method for preparing a high temperature heat flow sensor based on SiC thermoelectric material as claimed in claim 9, wherein: in the step 5), a stripping process or an electroplating process is adopted to form the metal layer; the material of the metal coating is selected from one or more of titanium, tungsten and platinum.
18. The method for preparing a high temperature heat flow sensor based on SiC thermoelectric material as claimed in claim 9, wherein: and 5) connecting the P-type SiC film resistance block and the N-type SiC film resistance block into a thermopile structure formed by connecting 1 thermocouple or a plurality of thermocouples in series.
19. The method for preparing a high temperature heat flow sensor based on SiC thermoelectric material as claimed in claim 9, wherein: in the step 6), forming the heat insulation cavity by adopting inductive coupling plasma etching to expose the composite dielectric film; the insulating cavity has a rectangular cross-section.
CN201711447533.4A 2017-12-27 2017-12-27 High-temperature heat flow sensor based on SiC thermoelectric material and preparation method thereof Active CN108007580B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201711447533.4A CN108007580B (en) 2017-12-27 2017-12-27 High-temperature heat flow sensor based on SiC thermoelectric material and preparation method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201711447533.4A CN108007580B (en) 2017-12-27 2017-12-27 High-temperature heat flow sensor based on SiC thermoelectric material and preparation method thereof

Publications (2)

Publication Number Publication Date
CN108007580A CN108007580A (en) 2018-05-08
CN108007580B true CN108007580B (en) 2020-03-31

Family

ID=62061789

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201711447533.4A Active CN108007580B (en) 2017-12-27 2017-12-27 High-temperature heat flow sensor based on SiC thermoelectric material and preparation method thereof

Country Status (1)

Country Link
CN (1) CN108007580B (en)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109141686B (en) * 2018-09-27 2021-04-13 北京遥测技术研究所 Thermal current sensor based on thermopile principle
CN111982323B (en) * 2019-05-24 2021-12-14 中国科学院上海微系统与信息技术研究所 Thermopile type high-temperature heat flow sensor and preparation method thereof
CN111174908A (en) * 2020-02-28 2020-05-19 李德龙 Laser detector and corresponding laser power meter
CN116046089B (en) * 2023-03-23 2023-07-18 东南大学 High-temperature MEMS thermal flow sensor based on silicon carbide pn junction temperature measurement and preparation method thereof

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6914343B2 (en) * 2001-12-12 2005-07-05 Hi-Z Technology, Inc. Thermoelectric power from environmental temperature cycles
CN203643055U (en) * 2013-11-25 2014-06-11 中国电子科技集团公司第四十八研究所 Thin-film heat flow sensor for high-temperature large-heat-flow measurement
CN104501970A (en) * 2014-12-18 2015-04-08 上海新微技术研发中心有限公司 Three-dimensional temperature detector and manufacturing method thereof
CN107123729A (en) * 2016-02-25 2017-09-01 中国科学院上海硅酸盐研究所 A kind of nanometer silicon carbide/P-type silicon germanium alloy base thermoelectrical composite material and preparation method thereof
CN208270086U (en) * 2017-12-27 2018-12-21 中国科学院上海微系统与信息技术研究所 High-temperature heat flux sensor based on SiC thermoelectric material

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101127642B1 (en) * 2009-06-24 2012-03-23 (주)아이뷰테크 Thermoelectric conversion device and method for manufacturing the same
KR101910575B1 (en) * 2013-01-10 2018-10-22 삼성전자주식회사 Infrared detector and infrared image sensor
WO2015006580A1 (en) * 2013-07-11 2015-01-15 North Carolina State University Microfluidic systems and methods for thermal flow cytometry

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6914343B2 (en) * 2001-12-12 2005-07-05 Hi-Z Technology, Inc. Thermoelectric power from environmental temperature cycles
CN203643055U (en) * 2013-11-25 2014-06-11 中国电子科技集团公司第四十八研究所 Thin-film heat flow sensor for high-temperature large-heat-flow measurement
CN104501970A (en) * 2014-12-18 2015-04-08 上海新微技术研发中心有限公司 Three-dimensional temperature detector and manufacturing method thereof
CN107123729A (en) * 2016-02-25 2017-09-01 中国科学院上海硅酸盐研究所 A kind of nanometer silicon carbide/P-type silicon germanium alloy base thermoelectrical composite material and preparation method thereof
CN208270086U (en) * 2017-12-27 2018-12-21 中国科学院上海微系统与信息技术研究所 High-temperature heat flux sensor based on SiC thermoelectric material

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
SILICON CARBIDE HIGH TEMPERATURE;MAN I LEI;《Ohiolink》;20111231;全文 *

Also Published As

Publication number Publication date
CN108007580A (en) 2018-05-08

Similar Documents

Publication Publication Date Title
CN108007580B (en) High-temperature heat flow sensor based on SiC thermoelectric material and preparation method thereof
CN108011030B (en) SiC thermopile type high-temperature heat flow sensor and preparation method thereof
KR100812996B1 (en) Micro gas sensor and method for manufacturing the same
CN101776483B (en) Non-refrigerant thermopile infrared detector and manufacturing method thereof
CN207375750U (en) A kind of MEMS micro-hotplates
TW200413240A (en) Micro-fabricated device with thermoelectric device and method of making
CN107345826B (en) Thermal gas flow sensor and preparation method thereof
CN111707404B (en) High-temperature-resistant silicon carbide pressure sensor and preparation method thereof
CN110745774B (en) SiC temperature sensor with cantilever beam structure and manufacturing method thereof
CN115127630A (en) Preparation method of double-shaft multidirectional MEMS (micro-electromechanical systems) thermal flow sensor
CN208270086U (en) High-temperature heat flux sensor based on SiC thermoelectric material
CN111982323B (en) Thermopile type high-temperature heat flow sensor and preparation method thereof
CN207967050U (en) A kind of SiC thermocouple types high-temperature heat flux sensor
CN114804005A (en) MEMS micro-hotplate based on transverse composite dielectric film and manufacturing method
CN114275731A (en) MEMS-based double-beam type micro-pressure sensing core and preparation process thereof
JP2016011876A (en) Pressure sensor and pressure sensor manufacturing method
JPH11317474A (en) Circuit boar and manufacture thereof
CN112938892B (en) Porous silicon heat insulation supported high-temperature heat flow sensor and preparation method thereof
CN216870437U (en) MEMS gas sensor
US20090212386A1 (en) Mems device and method of making same
CN110862063A (en) Temperature sensor preparation method and temperature sensor
CN113023658A (en) Resonant micro-cantilever chip and preparation method thereof
CN109813490B (en) MEMS capacitive vacuum gauge and manufacturing method thereof
CN102818516A (en) Sensor chip of high-temperature resistant silicone strainometer and manufacturing method of sensor chip
CN112067189A (en) Pressure sensor with peripheral medium isolation cup structure and preparation method thereof

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant