CN110780090A - Piezoresistive acceleration sensor based on silicon carbide material and manufacturing method thereof - Google Patents

Abstract

The present disclosure provides a piezoresistive acceleration sensor based on silicon carbide material. Based on the piezoresistive effect, a double cantilever beam design is adopted, and the resistance bars and lines whose resistance changes with stress are designed to form a Wheatons bridge. The substrate of the sensitive element is silicon carbide, the resistance is doped silicon carbide material, and the surface wiring material is gold. And the package design of the whole device is proposed, including the glass top cover and the bottom silicon-based package used as a limiter, and the ceramic package. Using silicon processing technology, the obtained silicon-based inner shell substrate can provide accurate vibration margin and protection limit. Through the gold wire ball bonding process, the input and output signals of the four pads of the sensor chip are led to the four metal pins on the side of the metal tube shell, and the 50-micron gold wire is used for signal transmission to ensure the stability of signal transmission and the chip. high temperature safety. The present disclosure also provides a manufacturing method of a piezoresistive acceleration sensor based on a silicon carbide material.

Description

Piezoresistive acceleration sensor based on silicon carbide material and its manufacturing method

technical field

The present disclosure relates to the technical field of electronic components, and in particular, to a piezoresistive acceleration sensor based on silicon carbide material and a manufacturing method thereof.

Background technique

So far, MEMS accelerometers have occupied a considerable proportion in the market and are widely used. For example, the MEMS acceleration sensor independently developed and manufactured by Qingdao Zhiteng Company in China completes product manufacturing through MEMS process such as etching and packaging, and achieves a bias stability of 0.24 to 6, a working temperature of -40 °C to 125 °C, and a range of ±2 to ±50g, and has been successfully used in aerospace vehicles. At the same time, by using doped silicon carbide material with excellent high temperature performance as the substrate of the sensitive element, a sensor sensitive element with better working performance under high temperature state can be realized.

At present, most of the materials that can be used for MEMS processing will change their properties in a high temperature environment, and even fail and destroy, thus limiting the work of MEMS devices to withstand the ambient temperature. Sensors have extremely high requirements on the performance of their sensitive components, so acceleration detection in high temperature environments has always been a challenging problem in the field of sensors. Furthermore, in the MEMS processing process, the processing of silicon carbide materials is extremely difficult to manufacture. The method is also the main problem that restricts the development of components on silicon carbide substrates.

SUMMARY OF THE INVENTION

In order to solve the technical problems in the prior art, the embodiments of the present disclosure provide a method and device for estimating CNC machining state based on real-time data and STEP-NC data, and the method proposes a MEMS acceleration sensor that can work in a high temperature environment The purpose is to solve the processing difficulties of silicon carbide materials and provide a sensor sensitive element that can work normally under high temperature.

In a first aspect, an embodiment of the present disclosure provides a piezoresistive acceleration sensor based on a silicon carbide material. The piezoresistive acceleration sensor includes: a substrate for a sensitive element, a resistor, and a surface trace material; the substrate for the sensitive element It is silicon carbide, the resistor is a component made of silicon carbide material doped with a predetermined threshold level, and the surface wiring material is gold.

In one embodiment, the piezoresistive acceleration sensor further includes: a glass upper cover, a bottom silicon-based substrate, and a ceramic package.

In one embodiment, the piezoresistive acceleration sensor further includes: a silicon-based inner package substrate, the silicon-based inner package substrate is configured to provide a vibration margin and a protection limit with a preset precision .

In one of the embodiments, the piezoresistive acceleration sensor is based on the piezoresistive effect and is designed with a double cantilever beam.

In a second aspect, an embodiment of the present disclosure provides a method for manufacturing a piezoresistive acceleration sensor based on a silicon carbide material, including the following steps: performing resistive photolithography etching on the epitaxial layer of a SiC wafer by a front-side dry etching machine, and Form a resistance pattern; use SiO ₂ to protect the spacer, and etch the window at a preset position to complete the dielectric hole lithography operation; etch the hollow part of the component to a preset depth by front-side deep groove lithography, and pass the preset Depth control the thickness of the cantilever beam where the resistance strip is located; ohmic contact is formed at the SiO ₂ window position of the resistance strip through a lift-off process; components are made into pads by metal wiring photolithography, and a metal is formed with the ohmic contact interconnection; the metal interconnection parts are sequentially subjected to cleaning operation, front-side glue operation, and front-side bonding operations to complete the backside thinning; Hard film operation, primer film operation, metal corrosion operation, and etching operation complete the back hole lithography operation.

In one of the embodiments, the method further includes: preparing a mask for silicon carbide; the preparing a mask for silicon carbide includes: processing the silicon carbide, and performing an overetching operation on a plurality of masks.

In one of the embodiments, the method further includes: performing the cleaning operation, the front-side glue operation, and the front-side bonding operation in sequence for the metal interconnection part to complete the backside thinning twice.

The invention provides a piezoresistive acceleration sensor based on silicon carbide material and a manufacturing method thereof. The core sensitive element of the piezoresistive acceleration sensor is based on the piezoresistive effect. The layout and location of the strips and lines are designed to form a complete Wheatons bridge. The substrate of the sensitive element is silicon carbide, the resistance is a highly doped silicon carbide material, and the surface wiring material is gold. Further, a package design scheme of the entire device is proposed, including a glass top cover and a bottom silicon-based tube used as a limiter, and a ceramic tube package design. Using silicon processing technology, the obtained high-precision silicon-based inner shell substrate can provide accurate vibration margin and protection limit. Through the gold wire ball bonding process, the input and output signals of the four pads of the sensor chip are led to the four metal pins on the side of the metal tube shell, and the 50-micron gold wire is used for signal transmission to ensure the stability of the signal transmission. High temperature safety of the chip.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present disclosure more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments:

1 is a schematic flow chart of steps of a method for manufacturing a silicon carbide material-based piezoresistive acceleration sensor according to an embodiment of the present invention;

2(a)-(c) are a top view and schematic diagram of circuit design of a silicon carbide acceleration sensitive element in a method for manufacturing a piezoresistive acceleration sensor based on silicon carbide material according to an embodiment of the present invention;

3 is a schematic cross-sectional view of a silicon carbide acceleration sensitive element in a method for manufacturing a piezoresistive acceleration sensor based on silicon carbide material according to an embodiment of the present invention;

4 is a three-dimensional schematic diagram of a bottom silicon-based package in a method for manufacturing a silicon carbide material-based piezoresistive acceleration sensor according to an embodiment of the present invention;

5 is a schematic diagram of a ceramic tube-shell packaging scheme in a method for manufacturing a piezoresistive acceleration sensor based on silicon carbide material according to an embodiment of the present invention;

6 is a schematic diagram of a silicon carbide processing mask in a method for manufacturing a piezoresistive acceleration sensor based on silicon carbide material according to an embodiment of the present invention;

7 is a schematic diagram of a silicon carbide processing mask overlay in a method for manufacturing a piezoresistive acceleration sensor based on silicon carbide material according to an embodiment of the present invention;

8 is a schematic diagram of a silicon carbide processing flow in a method for manufacturing a piezoresistive acceleration sensor based on silicon carbide material according to an embodiment of the present invention;

FIG. 9 is a schematic diagram of a real silicon carbide resistive lithography plate in a method for manufacturing a piezoresistive acceleration sensor based on silicon carbide material according to an embodiment of the present invention;

10 is a schematic diagram of a silicon carbide resistance machining process in a method for manufacturing a piezoresistive acceleration sensor based on silicon carbide materials according to an embodiment of the present invention;

11 is a schematic diagram of a silicon carbide resistive etching pattern observed by SEM in a manufacturing method of a silicon carbide material-based piezoresistive acceleration sensor according to an embodiment of the present invention;

12 is a schematic diagram of an insulating medium hole lithography plate in a method for manufacturing a piezoresistive acceleration sensor based on silicon carbide material according to an embodiment of the present invention;

13 is a schematic diagram of insulating medium hole lithography in a method for manufacturing a piezoresistive acceleration sensor based on silicon carbide material according to an embodiment of the present invention;

14 is a schematic diagram of optical microscope observation after the insulating medium hole is etched in a method for manufacturing a piezoresistive acceleration sensor based on silicon carbide material according to an embodiment of the present invention;

15 is a schematic diagram of a front face deep groove etching lithography plate in a method for manufacturing a piezoresistive acceleration sensor based on silicon carbide material according to an embodiment of the present invention;

16 is a schematic diagram of front-side deep groove etching in a method for manufacturing a piezoresistive acceleration sensor based on silicon carbide material according to an embodiment of the present invention;

17 is a schematic diagram of optical microscope observation after front-side deep groove etching in a method for manufacturing a piezoresistive acceleration sensor based on silicon carbide material according to an embodiment of the present invention;

18 is a schematic diagram of an ohmic contact lithography plate in a method for manufacturing a piezoresistive acceleration sensor based on silicon carbide material according to an embodiment of the present invention;

19 is a schematic diagram of ohmic contact lithography in a method for manufacturing a piezoresistive acceleration sensor based on silicon carbide material according to an embodiment of the present invention;

20 is a schematic diagram of a microscope observation ohmic contact pattern in a method for manufacturing a piezoresistive acceleration sensor based on silicon carbide material according to an embodiment of the present invention;

21 is a schematic diagram of an ohmic contact pattern observed by an optical microscope in a method for manufacturing a piezoresistive acceleration sensor based on silicon carbide material according to an embodiment of the present invention;

22 is a schematic diagram of an ohmic contact pattern observed by SEM in a method for manufacturing a piezoresistive acceleration sensor based on a silicon carbide material according to an embodiment of the present invention;

23 is a schematic diagram of a pattern after optical microscope observation of metal wiring lithography in a method for manufacturing a piezoresistive acceleration sensor based on silicon carbide material according to an embodiment of the present invention;

FIG. 24 is a schematic diagram of the optical microscope observation of a metal wiring stripped off in a manufacturing method of a silicon carbide material-based piezoresistive acceleration sensor according to an embodiment of the present invention;

FIG. 25 is a simplified cross-sectional view of a cantilever beam process in a method for manufacturing a silicon carbide material-based piezoresistive acceleration sensor according to an embodiment of the present invention.

Detailed ways

The present application will be further described in detail below with reference to the accompanying drawings and embodiments.

In the following introduction, the terms "first" and "second" are used for descriptive purposes only, and should not be construed as indicating or implying relative importance. The following introduction provides multiple embodiments of the present disclosure, and the different embodiments may be substituted or combined in combination, so this application should also be considered to include all possible combinations of the same and/or different embodiments described. Thus, if one embodiment includes features A, B, C and another embodiment includes features B, D, the application should also be considered to include all other possible combinations of one or more of A, B, C, D example, although this example may not be explicitly described in the following content.

In order to make the objectives, technical solutions and advantages of the present invention clearer, the following examples and in conjunction with the accompanying drawings, the specific implementation of a silicon carbide material-based piezoresistive acceleration sensor and its manufacturing method will be further detailed. illustrate. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention.

In one embodiment, a piezoresistive acceleration sensor based on silicon carbide material is disclosed. Specifically, the piezoresistive acceleration sensor includes: a substrate of a sensitive element, a resistor and a surface wiring material; the substrate of the sensitive element is silicon carbide, and the resistor is an element composed of a silicon carbide material doped with a preset threshold level device, the surface wiring material is gold. In addition, it should be noted that the piezoresistive acceleration sensor further includes: a glass upper cover, a bottom silicon-based tube case and a ceramic tube case.

Further, in one embodiment, the piezoresistive acceleration sensor further includes: a silicon-based inner package substrate, the silicon-based inner package substrate is configured to provide a vibration margin and a protection limit with a preset precision . Furthermore, in one embodiment, the piezoresistive acceleration sensor is based on the piezoresistive effect and is designed with a double cantilever beam.

As shown in FIG. 1, it is a schematic flowchart of a manufacturing method of a silicon carbide material-based piezoresistive acceleration sensor in one embodiment, which specifically includes the following steps:

In step 101, resist photolithography is performed on the epitaxial layer of the SiC wafer by a front-side dry etching machine, and a resistive pattern is formed.

Step 102 , using SiO ₂ to protect the spacer, and etching a window at a preset position to complete the dielectric hole lithography operation.

Step 103 , etch the hollow part of the component to a preset depth by front-side deep groove lithography, and control the thickness of the cantilever beam where the resistance strip is located by the preset depth.

Step 104, forming an ohmic contact at the position of the SiO ₂ window of the resistance strip through a lift-off process.

In step 105, the component is made into a pad by a metal wiring photolithography method, and a metal interconnection is formed with the ohmic contact.

In step 106 , the metal interconnection portion is sequentially thinned on the back side through a cleaning operation, a front-side gluing operation, and a front-side bonding operation.

Step 107 , the processed metal interconnection portion is then sequentially subjected to sputtering operation, photolithography operation, development operation, film hardening operation, priming film operation, metal corrosion operation, and etching operation to complete the back hole lithography operation.

In addition, in one embodiment, the method further includes: preparing a mask of silicon carbide. The preparation of the mask for silicon carbide includes: processing the silicon carbide, and performing an overlay operation on multiple masks.

In addition, in one embodiment, it should also be noted that the number of times that the metal interconnection portion is sequentially thinned on the back surface through the cleaning operation, the front surface gluing operation, and the front surface bonding operation is twice.

In order to more clearly understand and apply the manufacturing method of the silicon carbide material-based piezoresistive acceleration sensor proposed by the present disclosure, the following example is performed. It should be noted that the scope of protection of the present disclosure is not limited to the following examples.

2-25 , specifically, the core sensitive element of the piezoresistive acceleration sensor designed in the present disclosure is based on the piezoresistive effect, which adopts a double cantilever beam design, as shown in FIG. 2(a)-(c), The resistance strips and lines whose resistance varies with stress are arranged as shown in Figure 2(a)-(c) to form a Wheatons bridge. In addition, as shown in FIG. 3 , the substrate of the sensitive element is silicon carbide, the resistance strip is completed by successively doping silicon carbide with heavy N and low P doping on silicon carbide, and the wire material is gold.

Further, the present disclosure proposes a package design solution for the entire device, including a glass top cover and a bottom silicon-based package used as a limiter, and a ceramic package design, as shown in FIGS. 4 and 5 . Using silicon processing technology, the obtained high-precision silicon-based inner shell substrate can provide accurate vibration margin and protection limit. Through the gold wire ball bonding process, the input and output signals of the four pads of the sensor chip are led to the four metal pins on the side of the metal tube shell, and the 50-micron gold wire is used for signal transmission to ensure the stability of the signal transmission. High temperature safety of the chip.

Further, the present disclosure also discloses a method for manufacturing a core sensitive element of an acceleration sensor based on silicon carbide, including: resistance lithography, dielectric hole lithography, front-side deep groove lithography, ohmic contact lithography, metal wiring photolithography Engraving, backside thinning and back hole lithography, a total of six masks plus one thinning.

First of all, for the pre-pattern preparation and processing preparation of the high temperature resistant silicon carbide acceleration sensor, the mask for preparing the silicon carbide is shown in Figure 6. Again, FIG. 7 is a schematic diagram of six masks after overetching; a schematic diagram of the processing flow of silicon carbide is shown in FIG. 8 . The processing accuracy needs to be further explained: the front overlay accuracy is not less than 2um, the back overlay accuracy is not less than 5um; the graphic line width error is not greater than 2um; the film deposition thickness is based on the ability to output electrical signals, which can be adjusted with the processing side. There is no requirement on the above; the etching depth error is not greater than 2um, and the verticality is not required, as close as possible to 90°. In addition, the requirements for cutting and packaging are: the chip can be packaged independently, and the voltage signal can be output on the chip pins.

Specifically, the main goal of resistance lithography is to etch the epitaxial layer of SiC material on the front side and form a resistance pattern. The lithography and simple flow chart are shown in Figure 9-11. Specifically, a dry etching machine is used to etch the epitaxial layer of the SiC wafer to obtain a pattern whose shape is intact and meets the process requirements, as shown in FIG. 11 .

The main purpose of the process stage of dielectric hole lithography is to use SiO2 to protect the isolation device, and to etch the window at the required position for the subsequent process development. The lithography plate and simple flow chart are shown in Figure 12-Figure 14. Specifically, a method etching machine is used to etch SiO2 to obtain a pattern that meets the process requirements, as shown in FIG. 14 .

The main purpose of the process stage of front-side deep groove lithography is to etch the front side of the hollow part of the device to a certain depth, and at the same time control the thickness of the cantilever beam where the resistance strip is located by this depth. The lithography and simple flow chart are shown in Figure 15-17. In addition, the main purpose of the ohmic contact photolithography process stage is to form ohmic contacts in the lift-off process at the position of the SiO2 window of the resistance strip. The lithography and simple flow chart are shown in Figure 18-22. Further, the main purpose of the gold uncle wiring photolithography process stage is to make pads and form metal interconnections with ohmic contacts. The specific flowchart is shown in Figure 23-24.

Further, the process stages of backside thinning mainly include cleaning, front-side glue coating protection, and front-side bonding. Specifically, regarding the cleaning operation, that is, before the process, the cleanliness of the front and back of the material needs to be ensured. The front-side process of the SiC wafer has been completed, and the contamination of the remaining impurities on the front side will cause damage to the front-side device in the subsequent process, and will directly affect the subsequent backside exposure process; the backside of the wafer needs to be thinned for this process, and larger particles should be avoided. Impurities are stained to prevent the subsequent thinning effect from being affected. After NMP soaking, ethanol washing, and deionized water washing, the SiC was cleaned. The cleanliness of the material is guaranteed.

Regarding the front-side glue protection, that is, before the bonding process, the front-side devices of the SiC wafer need to be glued and protected. When using low-temperature wax (melting point about 85°) for bonding, a photoresist with moderate viscosity can be simply used to spread the protective glue. Prevent contamination of flocs when spin coating on the front side of SiC wafers. After the glue is evened, the glue distribution table should be cleaned in time to prevent contamination. At the same time, the corners of the back of the wafer should be cleaned to ensure the uniformity of the wafer glue. After the glue leveling is completed, the SiC wafer is placed on a hot stage for baking. After cooling, a thickness tester is used to measure the thickness at 5 points in the plane. The next step of the bonding process can be continued if the difference in the thickness measurement of the front 5 points is less than 10um.

Regarding front bonding, that is, selecting a sapphire holder whose uniformity meets the process, and using high-temperature wax to bond the SiC wafer to the sapphire holder. After bonding, use a thickness tester for in-plane 5-point thickness measurement. If the difference in thickness measurement at 5 points on the front is less than 10um, the next step can be continued. Continue to bond the back of the sapphire holder to the special glass holder, and measure the thickness of the front of the wafer after bonding. Generally speaking, this step has little effect on the uniformity of the previous wafer bonding, and the measured value should be the same as the previous one. basically the same.

In addition, it should be noted that a manufacturing method of a piezoresistive acceleration sensor based on silicon carbide material proposed in the present disclosure includes: resistance lithography, dielectric hole lithography, front-side deep groove lithography, ohmic contact lithography, metal wiring Lithography, backside thinning and back hole lithography, a total of six masks plus one thinning. Specifically, the backside thinning is to place the SiC wafer on the fixture with the side to be thinned facing up, and after confirming that the backside glass holder is vacuum-adsorbed, select an appropriate grinding liquid, and use a thinning machine to start wafer thinning. After many tests and adjustments, this process ensures that the backside of the SiC wafer is thinned, the wafer structure is intact, and there are no obvious scratches. It lays a solid foundation for the development of the subsequent back hole etching process.

Furthermore, the back hole photolithography process stages include sputtering, photolithography, development, hardening, priming, metal etching, and etching. Specifically, regarding the sputtering process, that is, through the research on SiC deep groove etching in the front part of this process, the deep groove etching experience is mainly used in the SiC backside etching of this process, and combined with the characteristics of backside etching, Properly adjust the process to achieve the desired effect. In this process, metal is still selected as the mask for SiC etching. According to the SiC/metal etching selection ratio that has been investigated and completed in the previous process, KS-400 is used for sputtering to obtain the mask required for this backside etching.

In addition, regarding the photolithography process, that is, consistent with the front-side deep trench etching process, the metal mask is patterned by a photolithography process. Uniform glue: spin-coat a uniform layer of photoresist on the SiC wafer with metal sputtered. Different from the front etching process, the wafer in this process is a 1/4 size 4-inch wafer, and after bonding, it is thinned After the sputtering process, it is still fixed on the sapphire holder, and its internal stress has changed to a certain extent. During the glue mixing process, special care should be taken, and the center should be strictly and accurately aligned to prevent cracks and chipping during the high-speed rotation of the glue. exception occurs. Pre-baking: Place the SiC wafer with uniform photoresist on a hot plate for baking. Exposure: Use a photolithography machine to expose the SiC wafer. The process parameters are the same as the front face deep groove etching. The contact exposure should reduce the pressure of the photolithography plate on the wafer and prevent the wafer from being crushed. In addition, this process is double-sided exposure, and the alignment mark is placed on the SiC wafer on the back side of the sapphire holder. Through the transparent sapphire holder, the multilayer structure of the high-temperature wax can be observed. This requires the front-end process to ensure sufficient cleaning of the front side of the SiC wafer before bonding. Impurities will obscure the alignment marks, resulting in difficult alignment, skewed exposure and other abnormalities.

Further, regarding the development process, that is, using developer to develop the SiC after exposure, the process parameters are the same as the front face deep groove etching. It should be noted that the thinned SiC wafer is relatively fragile, and care should be taken to prevent debris. Especially when nitrogen is used to purge the wafer, the pressure of the nitrogen gun should be properly controlled. In addition, regarding the hardening process, that is, after the photoresist pattern is transferred, the SiC wafer is placed on the hot plate for hardening, and the process parameters are the same as the front side deep groove etching. Due to the deep groove etching on the front side, the metal mask used in the backside etching is thicker, and the etching time is 1 to 5 times that of the frontside etching. Bake to harden film. In addition, regarding the primer film process, that is, using Trymax, the primer film process is performed on the SiC wafer, and the process parameters are the same as the front side deep groove etching.

Further, regarding the process of etching metal, that is, after the photolithography process is completed, we perform a wet etching process on the metal mask of the SiC wafer, and the process parameters are basically the same as those of the front-side deep groove etching. In addition, regarding the etching process, that is, using the S dry etching machine to etch SiC, the etching menu is the same as the front-side deep groove etching. After many tests, the front side deep groove etching process menu is used to perform the backside etching of this process. Deep slot hole patterns can be obtained stably. The difference from the front-side deep groove etching process is that the backside etching requires more precise judgment and control of the etching end point. The etching process is shown in Figure 25. That is, as shown in Figure 25, after deep groove etching on the front side and hole etching on the back side, the device forms a back-shaped structure, and the middle part is only supported by two cantilever beams. The thickness of the cantilever beam structure is determined by the depth of the front etching and the depth of the back etching. How to control the backside etching depth is very important for this process. The thickness of the cantilever beam can be controlled more precisely when the etching rate is reduced when the etching end point is approached.

To sum up, the manufacturing method of the piezoresistive acceleration sensor based on silicon carbide material proposed in the present disclosure can detect the vibration condition and motion acceleration data of the measured object in real time, and the silicon carbide base sensitive element can withstand extremely high temperature, and the range Larger range. It can realize the complete processing process of silicon carbide substrate materials, and reasonably solve the process difficulties such as etching, ohmic contact and wire bonding in the processing process, and provide accurate and accurate processing and manufacturing of acceleration sensors for piezoresistive silicon carbide-based materials. Process information.

The invention provides a piezoresistive acceleration sensor based on silicon carbide material and a manufacturing method thereof. The core sensitive element of the piezoresistive acceleration sensor is based on the piezoresistive effect. The layout and location of the strips and lines are designed to form a complete Wheatons bridge. The substrate of the sensitive element is silicon carbide, the resistance is doped silicon carbide material, and the surface wiring material is gold. Further, a package design scheme of the entire device is proposed, including a glass top cover and a bottom silicon-based tube used as a limiter, and a ceramic tube package design. Using silicon processing technology, the obtained high-precision silicon-based inner shell substrate can provide accurate vibration margin and protection limit. Through the gold wire ball bonding process, the input and output signals of the four pads of the sensor chip are led to the four metal pins on the side of the metal tube shell, and the 50-micron gold wire is used for signal transmission to ensure the stability of the signal transmission. High temperature safety of the chip.

An embodiment of the present invention further provides a computer-readable storage medium, where a computer program is stored on the computer-readable storage medium, and the program is executed by the processor in FIG. 1 .

Embodiments of the present invention also provide a computer program product including instructions. When the computer program product is run on a computer, the computer is caused to perform the method of FIG. 1 described above.

Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be implemented by instructing relevant hardware through a computer program, and the program can be stored in a computer-readable storage medium. During execution, the processes of the embodiments of the above-mentioned methods may be included. The storage medium may be a magnetic disk, an optical disk, a read-only memory (Read-Only Memory, ROM), or a random access memory (Random Access Memory, RAM) or the like.

The above-mentioned embodiments only represent several embodiments of the present invention, and the descriptions thereof are specific and detailed, but should not be construed as a limitation on the scope of the patent of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can also be made, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

The basic principles of the present disclosure have been described above with reference to specific embodiments. However, it should be pointed out that the advantages, advantages, effects, etc. mentioned in the present disclosure are only examples rather than limitations, and these advantages, advantages, effects, etc. should not be considered to be A must-have for each embodiment of the present disclosure. In addition, the specific details disclosed above are only for the purpose of example and easy understanding, but not for limitation, and the above details do not limit the present disclosure to be implemented by using the above specific details.

The block diagrams of devices, apparatuses, apparatuses, and systems referred to in this disclosure are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will appreciate, these means, apparatuses, apparatuses, systems may be connected, arranged, configured in any manner. Words such as "including", "including", "having" and the like are open-ended words meaning "including but not limited to" and are used interchangeably therewith. As used herein, the words "or" and "and" refer to and are used interchangeably with the word "and/or" unless the context clearly dictates otherwise. As used herein, the word "such as" refers to and is used interchangeably with the phrase "such as but not limited to".

Also, as used herein, the use of "or" in a listing of items beginning with "at least one" indicates a separate listing, eg, a listing of "at least one of A, B, or C" means A or B or C , or AB or AC or BC, or ABC (ie A and B and C). Furthermore, the word "exemplary" does not imply that the described example is preferred or better than other examples.

The foregoing description has been presented for the purposes of illustration and description. Furthermore, this description is not intended to limit embodiments of the present disclosure to the forms disclosed herein. Although a number of example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

Claims (7)

1. A piezoresistive acceleration sensor based on silicon carbide material, characterized in that it comprises: sensitive element substrate, resistor and surface wiring material; the sensitive element substrate is silicon carbide, the resistor is a component formed by silicon carbide materials doped with a preset threshold degree, and the surface wiring material is gold.

2. The silicon carbide material-based piezoresistive acceleration sensor according to claim 1, characterized in that it further comprises: a glass upper cover, a bottom silicon-based substrate and a ceramic tube shell.

3. The silicon carbide material-based piezoresistive acceleration sensor according to claim 1, characterized in that it further comprises: a silicon-based inner package substrate configured to provide a vibration margin of a predetermined precision and a protection limit.

4. The silicon carbide material-based piezoresistive acceleration sensor according to claim 1, characterized in that it is based on piezoresistive effect, done with a double cantilever beam design.

5. A manufacturing method of a piezoresistive acceleration sensor based on silicon carbide materials is characterized by comprising the following steps:

carrying out resistance photoetching on the epitaxial layer of the SiC wafer by using a front dry etching machine, and forming a resistance pattern;

using SiO ₂Protecting the isolation piece, and etching the window at a preset position to finish the medium hole photoetching operation;

etching the front surface of the hollow part of the component by a preset depth in a front surface deep groove photoetching mode, and controlling the position thickness of the cantilever beam where the resistance strip is located by the preset depth;

SiO in the resistor strip ₂Ohmic contact is formed at the position of the window through lift-off technology;

manufacturing the component into pad by a metal wiring photoetching method, and forming metal interconnection with the ohmic contact;

the back thinning of the metal interconnection part is completed through cleaning operation, front glue homogenizing operation and front bonding operation in sequence;

and then sequentially carrying out sputtering operation, photoetching operation, developing operation, film hardening operation, priming film operation, metal corrosion operation and etching operation on the processed metal interconnection part to finish back hole photoetching operation.

6. The method of manufacturing a piezoresistive acceleration sensor based on silicon carbide material according to claim 5, characterized in that it further comprises: and preparing a mask of silicon carbide.

7. The method of manufacturing a piezoresistive acceleration sensor based on silicon carbide material according to claim 5, characterized in that it further comprises: and the number of times of finishing back thinning by sequentially carrying out cleaning operation, front glue homogenizing operation and front bonding operation on the metal interconnection part is twice.

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