CN118225307B - Pressure sensor integrated with protective structure and preparation method thereof - Google Patents
Pressure sensor integrated with protective structure and preparation method thereof Download PDFInfo
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- CN118225307B CN118225307B CN202410660127.XA CN202410660127A CN118225307B CN 118225307 B CN118225307 B CN 118225307B CN 202410660127 A CN202410660127 A CN 202410660127A CN 118225307 B CN118225307 B CN 118225307B
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- 238000002360 preparation method Methods 0.000 title abstract description 5
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- 238000000137 annealing Methods 0.000 claims description 29
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Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L19/00—Details of, or accessories for, apparatus for measuring steady or quasi-steady pressure of a fluent medium insofar as such details or accessories are not special to particular types of pressure gauges
- G01L19/06—Means for preventing overload or deleterious influence of the measured medium on the measuring device or vice versa
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L19/00—Details of, or accessories for, apparatus for measuring steady or quasi-steady pressure of a fluent medium insofar as such details or accessories are not special to particular types of pressure gauges
- G01L19/04—Means for compensating for effects of changes of temperature, i.e. other than electric compensation
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L9/00—Measuring steady of quasi-steady pressure of fluid or fluent solid material by electric or magnetic pressure-sensitive elements; Transmitting or indicating the displacement of mechanical pressure-sensitive elements, used to measure the steady or quasi-steady pressure of a fluid or fluent solid material, by electric or magnetic means
- G01L9/12—Measuring steady of quasi-steady pressure of fluid or fluent solid material by electric or magnetic pressure-sensitive elements; Transmitting or indicating the displacement of mechanical pressure-sensitive elements, used to measure the steady or quasi-steady pressure of a fluid or fluent solid material, by electric or magnetic means by making use of variations in capacitance, i.e. electric circuits therefor
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L9/00—Measuring steady of quasi-steady pressure of fluid or fluent solid material by electric or magnetic pressure-sensitive elements; Transmitting or indicating the displacement of mechanical pressure-sensitive elements, used to measure the steady or quasi-steady pressure of a fluid or fluent solid material, by electric or magnetic means
- G01L9/12—Measuring steady of quasi-steady pressure of fluid or fluent solid material by electric or magnetic pressure-sensitive elements; Transmitting or indicating the displacement of mechanical pressure-sensitive elements, used to measure the steady or quasi-steady pressure of a fluid or fluent solid material, by electric or magnetic means by making use of variations in capacitance, i.e. electric circuits therefor
- G01L9/125—Measuring steady of quasi-steady pressure of fluid or fluent solid material by electric or magnetic pressure-sensitive elements; Transmitting or indicating the displacement of mechanical pressure-sensitive elements, used to measure the steady or quasi-steady pressure of a fluid or fluent solid material, by electric or magnetic means by making use of variations in capacitance, i.e. electric circuits therefor with temperature compensating means
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measuring Fluid Pressure (AREA)
- Pressure Sensors (AREA)
Abstract
The invention discloses a pressure sensor integrated with a protective structure and a preparation method thereof, and relates to the technical field of pressure sensors; at least one side edge of at least part of the PN junctions is provided with at least one protection structure, the protection structure surrounds along the diffusion area of the PN junctions and forms a protection part for limiting the outward diffusion of the PN junctions, and the ion concentration of the protection part is gradually reduced from one side close to the PN junctions to the other side; each protection part is grounded through a grounding structure, one side of the protection part with high ion concentration is used for providing strongest electric isolation and protection to prevent carrier uncontrolled migration, the other side of the protection part with low ion concentration is provided with the protection part with low ion concentration, the influence on the whole capacitance of the pressure sensor is reduced, the sensitivity is maintained, the PN junction is effectively isolated, and the edge effect and leakage current are reduced.
Description
Technical Field
The invention relates to the technical field of pressure sensors, in particular to a pressure sensor integrated with a protective structure and a preparation method thereof.
Background
The pressure sensor senses pressure signals through a pressure sensitive unit, can convert the pressure signals into usable output electric signals according to a certain rule, and then is processed into corresponding required analog output or digital output modes by a signal processing unit, and the pressure sensitive unit of the pressure sensor commonly used comprises a ceramic capacitor/ceramic resistor/glass micro-melting/sputtering film/micro-electromechanical system (MEMS).
In the processing technology of the diffusion silicon type pressure sensor, P ions are generally injected into a bare silicon wafer to form a PN junction, redundant holes (positive load bodies) are contained in a P-type semiconductor, electrons (negative load bodies) are contained in an N-type semiconductor, when the P-type semiconductor and the N-type semiconductor are combined through a process processing technology, positive and negative charge carriers in the P-type semiconductor and the N-type semiconductor are combined to form a space domain barrier, so that a built-in electric field is formed, and the built-in electric field is balanced under ideal conditions to prevent the internal diffusion of the PN junction.
However, in the process of processing, especially in the growth process of an insulating layer, metal ion pollution is often caused in or on the insulating layer due to the limitation of the process environment and the process parameters, so that the defects such as surface defects, pollutants, temperature effects and the like are caused on the protective layer, and the sensor generates electric leakage, therefore, the existing diffusion silicon pressure sensor has various influencing factors in the process, so that extra current passes through a PN junction or carrier recombination phenomenon occurs, electrons jump from a P-type region to an N-type region to form leakage current, and the performance of the pressure sensor is unstable.
Disclosure of Invention
Based on the above, the invention aims to provide a pressure sensor with an integrated protection structure and a preparation method thereof, so as to solve the technical problem that in the background art, the existing diffusion silicon pressure sensor has multiple influencing factors in the processing process, so that extra current passes through a PN junction or carrier recombination phenomenon occurs, electrons jump from a P-type region to an N-type region to form leakage current, and the performance of the pressure sensor is unstable.
The invention provides a pressure sensor integrated with a protective structure, which comprises a substrate, a plurality of PN junctions, a plurality of protective structures and a grounding structure, wherein the PN junctions, the protective structures and the grounding structure are arranged on the substrate;
At least one side edge of at least part of the PN junctions is provided with at least one protection structure, the protection structure surrounds along the diffusion area of the PN junctions and forms a protection part for limiting the PN junctions to diffuse outwards, and the ion concentration of the protection part is gradually reduced from one side close to the PN junctions to the other side;
wherein each protection part is grounded through the grounding structure.
Further, the PN junctions and the protective structures are disposed on the same side of the substrate, and each of the PN junctions and each of the protective structures is disposed opposite to each side of the substrate.
Further, the grounding structure comprises a plurality of grounding electrodes and at least one grounding electrode ring;
One end of each grounding electrode is connected with each protection part, the other end of each grounding electrode is connected with the grounding electrode ring, and the grounding electrode ring is used for grounding;
And the substrate is provided with a through hole for connecting each grounding electrode with the grounding electrode ring.
Further, the ground electrode and the ground electrode ring are respectively arranged on two opposite sides of the substrate;
The side edges of the grounding electrode ring are opposite to the side edges of the substrate, and the through holes opposite to each grounding electrode are located in the side edges of the grounding electrode ring.
Further, the pressure sensor further includes a protective layer stacked on the substrate, and the protective layer covers the plurality of ground electrodes, the plurality of PN junctions, and the plurality of protective structures.
Further, the PN junctions and the protective structures are disposed below the surface of the substrate, and the ground electrodes are disposed above the surface of the substrate, so that when the protective layer covers the ground electrodes, a portion of the protective layer extends outward.
Further, each two PN junctions of the plurality of PN junctions are symmetrically arranged, and each PN junction of at least one pair of PN junctions is respectively connected with one grounding electrode.
Further, every two PN junctions in the plurality of PN junctions are symmetrically arranged, and at least two PN junctions in every two pairs of PN junctions are adjacently arranged;
at least two adjacent PN junctions are respectively connected with one grounding electrode.
Further, the ion concentration of the protection part close to the PN junction is 1e 18-1e19, and the ion concentration of the protection part far away from the PN junction is 1e 17-1e18.
Another aspect of the present invention is to provide a method for manufacturing a pressure sensor integrated with a protective structure, the method for manufacturing the pressure sensor integrated with the protective structure, the method comprising:
Providing a substrate;
etching is carried out on the substrate to form a through hole in the grounding structure;
Performing ion implantation on the substrate, and controlling implantation energy, implantation dose, annealing temperature and annealing time of the ions to form a PN junction on the substrate;
Ion doping is carried out for a plurality of times on the adjacent part of the PN junction diffusion region, and the implantation energy, the implantation dosage, the annealing temperature and the annealing time of the ion doping are controlled so as to form a protection part which surrounds the PN junction diffusion region along the PN junction and is used for limiting the PN junction to diffuse outwards on the substrate;
in the ion doping for multiple times, the annealing time of the ion doping for multiple times gradually decreases from large to small, so that the ion concentration of the protection part gradually decreases from one side close to the PN junction to the other side;
The ion concentration of the protection part close to the PN junction is 1e 18-1e19, and the ion concentration of the protection part far away from the PN junction is 1e 17-1e18.
Compared with the prior art, the invention has the beneficial effects that:
In the pressure sensor with the integrated protection structure, the protection structure is arranged on the substrate, the protection structure surrounds along the diffusion area of the PN junction and forms the protection part for limiting the outward diffusion of the PN junction, the ion concentration of the protection part is gradually reduced from one side close to the PN junction to the other side, the protection part with high ion concentration on one side is used for providing the strongest electric isolation and protection to prevent the uncontrolled migration of carriers, and the protection part with low ion concentration on the other side is used for reducing the influence on the whole capacitance of the pressure sensor and maintaining the sensitivity, and by adopting the design method of the protection part with high ion concentration, the potential barrier can be formed through the high doping area in practical situations, the edge effect and the leakage current are effectively isolated, the protection part is ensured to effectively protect the sensitive PN junction on an electric appliance and physically, the mechanical stability of the whole pressure sensor is improved, and the influence caused by external stress and temperature is resisted.
Drawings
FIG. 1 is a side view of a pressure sensor incorporating a guard structure according to an embodiment of the present invention;
FIG. 2 is a top view of a pressure sensor integrated with a protective structure according to an embodiment of the present invention;
Fig. 3 is a bottom view of a pressure sensor integrated with a guard structure according to an embodiment of the present invention.
In the figure: 1. a substrate; 2. a PN junction; 3. a protective part; 4. a grounding structure; 401. a ground electrode; 402. a ground electrode ring; 403. a through hole; 5. a protective layer; 6. and wiring electrodes.
Detailed Description
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.
Furthermore, the term "and/or" as used herein includes any and all combinations of one or more of the associated listed items. In the detailed description and claims, a list of items connected by the term "one of" may mean any of the listed items. For example, if items a and B are listed, the phrase "one of a and B" means either only a or only B. In another example, if items A, B and C are listed, then the phrase "one of A, B and C" means only a; only B; or only C. Item a may comprise a single element or multiple elements. Item B may comprise a single element or multiple elements. Item C may comprise a single element or multiple elements. In the detailed description and claims, a list of items connected by the terms "at least one of," "at least one of," or other similar terms may mean any combination of the listed items. For example, if items a and B are listed, the phrase "at least one of a and B" or "at least one of a or B" means only a; only B; or A and B. In another example, if items A, B and C are listed, the phrase "at least one of A, B and C" or "at least one of A, B or C" means only a; or only B; only C; a and B (excluding C); a and C (excluding B); b and instruction 4C (excluding a); or A, B and C. Item a may comprise a single element or multiple elements. Item B may comprise a single element or multiple elements. Item C may comprise a single element or multiple elements.
First embodiment
Referring to fig. 1 to 3, a pressure sensor with an integrated protection structure according to a first embodiment of the present invention includes a substrate 1, and a plurality of PN junctions 2, a plurality of protection structures, and a grounding structure 4 disposed on the substrate 1;
at least one side edge of at least part of PN junctions 2 in the plurality of PN junctions 2 is provided with at least one protection structure, the protection structure surrounds along the diffusion area of the PN junctions 2 and forms a protection part 3 for limiting outward diffusion of the PN junctions 2, and the ion concentration of the protection part 3 is gradually reduced from one side close to the PN junctions 2 to the other side;
wherein each guard 3 is grounded via a grounding structure 4.
Specifically, in some preferred embodiments, the PN junctions 2 and the protection structures are disposed on the same side of the substrate 1, and each PN junction 2 and each protection structure are disposed opposite to each side of the substrate 1.
Furthermore, the number of the PN junctions 2 disposed on the substrate 1 may be four, and the substrate 1 may have a rectangular structure with four edges, i.e. the four PN junctions 2 are disposed opposite to the four edges, respectively, and it should be noted that the term in this embodiment is not limited to the number of the PN junctions 2 and the edges of the substrate 1, but may also have other numbers of the PN junctions 2 and other numbers of the edges, which is not particularly limited herein.
In order to avoid the technical problem that the pressure sensor has unstable performance due to the fact that extra current passes through the PN junction 2 or carrier recombination phenomenon occurs in the processing process of the pressure sensor and electrons jump from a P-type region to an N-type region to form leakage current, in the embodiment, a protective structure is arranged on a substrate 1 and surrounds and forms a protective part 3 used for limiting the outward diffusion of the PN junction 2 along a diffusion region of the PN junction 2, the ion concentration of the protective part 3 is gradually reduced from one side close to the PN junction 2 to the other side, the protective part 3 with high ion concentration on one side is used for providing strongest electrical isolation and protection, carrier uncontrolled migration is prevented, and the protective part 3 with low ion concentration, the ion concentration of which is gradually reduced, is used for reducing the influence on the integral capacitance of the pressure sensor and maintaining sensitivity, and the protective part 3 with high concentration is designed in practical situations through a high doping region to form a potential barrier, so that the PN junction 2 is effectively isolated, the edge effect and the leakage current are reduced, the protective part 3 and the physical and the electrical appliance are effectively protected from the whole junction 2 is further resistant to the mechanical stress.
Specifically, in some preferred embodiments, the ion concentration of the guard 3 near the PN junction 2 is 1e 18-1e19, and the ion concentration of the guard 3 far from the PN junction 2 is 1e 17-1e18.
In addition, in order to make the protection portion 3 grounded, in this embodiment, the grounding structure 4 includes a plurality of grounding electrodes 401 and at least one grounding electrode ring 402; one end of each of the plurality of ground electrodes 401 is connected to each of the guard portions 3, the other end of each of the plurality of ground electrodes 401 is connected to a ground electrode ring 402, and the ground electrode ring 402 is used for grounding;
Wherein the base 1 is provided with a through hole 403 for each of the ground electrode 401 and the ground electrode ring 402 to be connected to each other.
Specifically, the ground electrode 401 and the ground electrode ring 402 are respectively provided on opposite sides of the substrate 1, and respective sides of the ground electrode ring 402 are provided opposite to respective sides of one side of the substrate 1, such that the through hole 403 opposite to each ground electrode 401 is located within the side of the ground electrode ring 402.
It should be noted that, in the present embodiment, the pressure sensor further includes a protective layer 5, the protective layer 5 is stacked on the substrate 1, the protective layer 5 covers the plurality of grounding electrodes 401, the plurality of PN junctions 2, and the plurality of protective structures, and the plurality of PN junctions 2 and the plurality of protective structures are disposed below the surface of the substrate 1, and the plurality of grounding electrodes 401 are disposed on the surface of the substrate 1, so that when the protective layer 5 covers the grounding electrodes 401, a portion of the protective layer 5 extends outwards.
Through the through hole 403, the impurity charges on the protective layer 5 are grounded, so that accumulation of the surface charges of the protective layer 5 is prevented, a stable reference potential is provided, the potential stability at two sides of the PN junction 2 is maintained, leakage caused by unstable potential is reduced, and the leakage problem of the PN junction 2 can be effectively improved.
It should be noted that, in some practical cases, in order to make the ground electrode ring 402 grounded, the pressure sensor further has a package tube shell, where the ground electrode ring 402 is connected to the package tube shell, and the package tube shell is provided with a ground lead post, so as to finally achieve the purpose of grounding the protection layer 5, and in order to prevent the through hole 403 from affecting the pressure sensor as a whole, the aperture of the through hole 403 is as minimum as possible, for example, the aperture is 20um, and the aspect ratio is 15:1.
In some preferred embodiments, every two PN junctions 2 of the plurality of PN junctions 2 are symmetrically disposed, and each PN junction 2 of at least one pair of PN junctions 2 is connected to a ground electrode 401, that is, when the number of the PN junctions 2 is four, every two PN junctions 2 of the four PN junctions 2 are symmetrical, and two PN junctions 2 of a pair are connected to the ground electrode 401.
In other preferred embodiments, every two PN junctions 2 of the plurality of PN junctions 2 are symmetrically disposed, and at least two PN junctions 2 of every two pairs of PN junctions 2 are disposed adjacently, i.e., one PN junction 2 of one pair is connected to the ground electrode 401, and one PN junction 2 of the other pair is connected to the ground electrode 401, and the two PN junctions 2 are disposed adjacently.
It should be noted that, in this example, the purpose of the through holes 403 is to guide out the metal ions in the protection layer 5 into the ground line, so as to prevent the reverse bias current generated in the protection layer 5 on the surface of the PN junction 2 from causing the surface leakage of the PN junction 2, and the protection layer 5 is an integral body, so that two symmetrical ground through holes 403 are designed to sufficiently guide out the metal charges in the protection layer 5 near the four PN junctions 2 into the ground line, and a small amount of ground electrode 401 is used, so that the production cost and steps can be reduced.
In order to facilitate electrical connection of each PN junction 2, a wiring electrode 6 is also disposed on the substrate 1.
In summary, compared with the traditional pressure sensor, the pressure sensor with the integrated protection structure provided by the invention has at least the following beneficial effects:
1. In the pressure sensor with the integrated protection structure, the protection structure is arranged on the substrate 1, the protection structure surrounds along the diffusion area of the PN junction 2, the protection part 3 for limiting the outward diffusion of the PN junction 2 is formed, the ion concentration of the protection part 3 is gradually reduced from one side close to the PN junction 2 to the other side, the protection part 3 with high ion concentration on one side is used for providing the strongest electric isolation and protection, the uncontrolled migration of carriers is prevented, the protection part 3 with low ion concentration, which is gradually reduced in ion concentration on the other side, is used for reducing the influence on the whole capacitance of the pressure sensor and maintaining the sensitivity, and the high-concentration protection part 3 design method is adopted, so that a potential barrier can be formed in practical situations through a high-doped area, the PN junction 2 is effectively isolated, the edge effect and leakage current are reduced, the protection part 3 is ensured to effectively protect the sensitive PN junction 2 on an electric appliance and physically, the mechanical stability of the whole pressure sensor is improved, and the influence caused by external stress and temperature is resisted.
2. According to the invention, the impurity charges on the protective layer 5 are grounded through the through holes 403, so that the accumulation of the charges on the surface of the protective layer 5 is prevented, a stable reference potential is provided, the potential stability at two sides of the PN junction 2 is maintained, the electric leakage caused by the unstable potential is reduced, and the electric leakage problem of the PN junction 2 can be effectively improved.
3. The protective structure provided by the invention can also effectively improve the service temperature of the pressure sensor.
Second embodiment
A second aspect of the present invention provides a method for manufacturing a pressure sensor integrated with a protective structure, for manufacturing the pressure sensor integrated with a protective structure in the first embodiment, the method comprising:
S01, providing a substrate;
It should be noted that the substrate may be a bare silicon wafer, and the bare silicon wafer is cleaned to clean residual stains on the bare silicon wafer, so as to prevent the subsequent process, such as making the photoresist generate bubbles, from affecting the photolithography result.
S02, etching is conducted on the substrate to form a through hole in the grounding structure;
s03, performing ion implantation on the substrate, and controlling implantation energy, implantation dosage, annealing temperature and annealing time of the ions to form a PN junction on the substrate;
the implantation ions may be boron ions, and the implantation energy may be 70keV; the implantation dose may be 5e15; the annealing temperature may be 1100 ℃; the annealing time may be 120min.
S04, carrying out ion doping for a plurality of times on the adjacent part of the PN junction diffusion region, and controlling the implantation energy, implantation dosage, annealing temperature and annealing time of the ion doping so as to form a protection part which surrounds the PN junction diffusion region along the substrate and is used for limiting the PN junction to diffuse outwards;
In the ion doping for multiple times, the annealing time of the ion doping for multiple times gradually decreases from large to small, so that the ion concentration of the protection part gradually decreases from one side close to the PN junction to the other side;
The ion concentration of the protection part close to the PN junction is 1e 18-1e19, and the ion concentration of the protection part far away from the PN junction is 1e 17-1e18.
It should be noted that the multiple doping is N-type doping, the doping ions may be, but not limited to, phosphorus ions, the doping parameters may be performed with reference to S03, and the implantation energy may be 70keV; the implant dose may be 1e 15-1e16, in some preferred embodiments 5e 15; the annealing temperature can be 900-1100 ℃; the annealing time may be 40min-120min.
It should be noted that, the doping concentration is mainly affected by the annealing temperature and the annealing time, so that among the process parameters of multiple doping, the parameters such as injection energy and measurement are basically the same, only different annealing times are required to be controlled to form the protection parts with different concentrations, the concentration of the protection part of the innermost layer is the highest, the annealing time is the longest, the annealing parameters of 1100 ℃/120min can be used, the annealing time of the protection part of the outermost layer is sequentially reduced, and the annealing time is respectively 90min-60min-40min, and the like, so that the stepped protection ring with the highest doping concentration of the internal protection part and the first reduction outwards can be formed.
The annealing temperature is controlled to 900-1100 ℃, and experiments prove that the same PN junction surface ion concentration can be finally formed, but the ion concentration is lower than the expected concentration ion implantation process and the annealing process are carried out in a vacuum environment at the temperature lower than 900 ℃, and a higher degree of cleanliness is required to prevent other impurity ions from being introduced. After annealing, the ion concentration range of the surface of the protection part of the innermost layer is 1e 18-1e19, the ion concentration of the secondary outer layer is 1e 17-1e18, and the ion concentration of the innermost layer is higher, so that the effect of preventing PN junction leakage is more obvious.
S05: forming a protective layer on the doped substrate;
Specifically, the protective layer is a layer of compact passivation material covered on the surface of the substrate, the passivation material can be PECVD (plasma enhanced chemical vapor deposition) and the like, a high-quality passivation film is formed in a lower-temperature environment by using plasma assistance, the damage to the surface of a silicon wafer caused by the high-temperature environment is prevented, and impurities such as metal ions and the like are prevented from being doped in the passivation layer in the process, wherein the passivation material can be silicon dioxide, silicon nitride, silicon karate and the like;
S06: and carrying out windowing treatment on the passivation layer, sputtering metal ions, and etching to form the connecting metal wire. The wires are divided into a test wire and a TSV grounding wire, and the TSV wires are connected with the through holes to prevent electric leakage on the surface of the PN junction;
s07: and finally, releasing the back pressure cavity to form a complete device structure.
In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
The foregoing examples illustrate only a few embodiments of the invention, which are described in detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.
Claims (7)
1. The pressure sensor integrated with the protective structure is characterized by comprising a substrate, a plurality of PN junctions, a plurality of protective structures and a grounding structure, wherein the PN junctions, the protective structures and the grounding structure are arranged on the substrate;
At least one side edge of at least part of the PN junctions is provided with at least one protection structure, the protection structure surrounds along the diffusion area of the PN junctions and forms a protection part for limiting the PN junctions to diffuse outwards, and the ion concentration of the protection part is gradually reduced from one side close to the PN junctions to the other side;
wherein each protection part is grounded through the grounding structure;
The PN junctions and the protective structures are arranged on the same side of the substrate, and each PN junction and each protective structure are arranged opposite to each side of one side of the substrate;
the grounding structure comprises a plurality of grounding electrodes and at least one grounding electrode ring;
One end of each grounding electrode is connected with each protection part, the other end of each grounding electrode is connected with the grounding electrode ring, and the grounding electrode ring is used for grounding;
Wherein, the substrate is provided with a through hole for connecting each grounding electrode and the grounding electrode ring;
the grounding electrode and the grounding electrode ring are respectively arranged on two opposite sides of the substrate;
The side edges of the grounding electrode ring are opposite to the side edges of the substrate, and the through holes opposite to each grounding electrode are located in the side edges of the grounding electrode ring.
2. The integrated guard structure pressure sensor of claim 1 further comprising a guard layer laminated over the substrate, the guard layer covering the plurality of ground electrodes, the plurality of PN junctions, and the plurality of guard structures.
3. The integrated guard structure pressure sensor of claim 2, wherein a plurality of said PN junctions and a plurality of said guard structures are disposed below the surface of said substrate and a plurality of said ground electrodes are disposed above the surface of said substrate such that a portion of said guard layers extend outwardly when said guard layers are applied to said ground electrodes.
4. The integrated guard structure pressure sensor of claim 1, wherein each two of the plurality of PN junctions are symmetrically disposed with respect to each other, and each of the at least one pair of PN junctions is connected to one of the ground electrodes.
5. The integrated guard structure pressure sensor of claim 1, wherein each two of the plurality of PN junctions are symmetrically disposed with respect to each other, and at least two of each two pairs of PN junctions are disposed adjacent to each other;
at least two adjacent PN junctions are respectively connected with one grounding electrode.
6. The integrated guard structure pressure sensor of claim 1, wherein the guard has an ion concentration of 1e 18-1e19 near the PN junction and 1e 17-1e18 away from the PN junction.
7. A method for manufacturing a pressure sensor integrated with a protective structure, wherein the method is used for manufacturing the pressure sensor integrated with a protective structure according to any one of claims 1 to 6, and the method comprises:
Providing a substrate;
etching is carried out on the substrate to form a through hole in the grounding structure;
Performing ion implantation on the substrate, and controlling implantation energy, implantation dose, annealing temperature and annealing time of the ions to form a PN junction on the substrate;
Ion doping is carried out for a plurality of times on the adjacent part of the PN junction diffusion region, and the implantation energy, the implantation dosage, the annealing temperature and the annealing time of the ion doping are controlled so as to form a protection part which surrounds the PN junction diffusion region along the PN junction and is used for limiting the PN junction to diffuse outwards on the substrate;
In the ion doping for multiple times, the annealing time of the ion doping for multiple times gradually decreases from large to small, so that the ion concentration of the protection part gradually decreases from one side close to the PN junction to the other side;
The ion concentration of the protection part close to the PN junction is 1e 18-1e19, and the ion concentration of the protection part far away from the PN junction is 1e 17-1e18.
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