CN116553471A - Pressure sensor chip and manufacturing method - Google Patents
Pressure sensor chip and manufacturing method Download PDFInfo
- Publication number
- CN116553471A CN116553471A CN202310630028.2A CN202310630028A CN116553471A CN 116553471 A CN116553471 A CN 116553471A CN 202310630028 A CN202310630028 A CN 202310630028A CN 116553471 A CN116553471 A CN 116553471A
- Authority
- CN
- China
- Prior art keywords
- silicon
- substrate
- pressure sensor
- silicon carbide
- type
- 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.)
- Pending
Links
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 34
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims abstract description 69
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 claims abstract description 67
- 229910010271 silicon carbide Inorganic materials 0.000 claims abstract description 67
- 239000000758 substrate Substances 0.000 claims abstract description 58
- 239000002184 metal Substances 0.000 claims abstract description 54
- 229910052751 metal Inorganic materials 0.000 claims abstract description 54
- 229910021421 monocrystalline silicon Inorganic materials 0.000 claims abstract description 34
- 235000012239 silicon dioxide Nutrition 0.000 claims abstract description 34
- 239000000377 silicon dioxide Substances 0.000 claims abstract description 33
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 35
- 229910052710 silicon Inorganic materials 0.000 claims description 35
- 239000010703 silicon Substances 0.000 claims description 35
- 238000005530 etching Methods 0.000 claims description 19
- 238000002161 passivation Methods 0.000 claims description 17
- 229910052581 Si3N4 Inorganic materials 0.000 claims description 15
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 claims description 15
- 239000012528 membrane Substances 0.000 claims description 10
- 238000000151 deposition Methods 0.000 claims description 7
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 5
- 239000012300 argon atmosphere Substances 0.000 claims description 3
- 239000011248 coating agent Substances 0.000 claims description 3
- 238000000576 coating method Methods 0.000 claims description 3
- 230000008020 evaporation Effects 0.000 claims description 3
- 238000001704 evaporation Methods 0.000 claims description 3
- 239000010931 gold Substances 0.000 claims description 3
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims description 2
- 238000000137 annealing Methods 0.000 claims description 2
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 claims description 2
- 229910052737 gold Inorganic materials 0.000 claims description 2
- 229910052759 nickel Inorganic materials 0.000 claims description 2
- 230000001590 oxidative effect Effects 0.000 claims description 2
- 229910052814 silicon oxide Inorganic materials 0.000 claims description 2
- 239000010936 titanium Substances 0.000 claims description 2
- 229910052719 titanium Inorganic materials 0.000 claims description 2
- 238000005516 engineering process Methods 0.000 abstract description 7
- 230000003647 oxidation Effects 0.000 abstract description 7
- 238000007254 oxidation reaction Methods 0.000 abstract description 7
- 238000000034 method Methods 0.000 description 16
- 235000012431 wafers Nutrition 0.000 description 11
- 238000010586 diagram Methods 0.000 description 8
- 230000008569 process Effects 0.000 description 8
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 4
- 230000008901 benefit Effects 0.000 description 4
- 239000010408 film Substances 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 238000000623 plasma-assisted chemical vapour deposition Methods 0.000 description 4
- 230000035945 sensitivity Effects 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- 230000005855 radiation Effects 0.000 description 3
- 239000004065 semiconductor Substances 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 239000007853 buffer solution Substances 0.000 description 2
- 238000004140 cleaning Methods 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 238000009616 inductively coupled plasma Methods 0.000 description 2
- 238000004806 packaging method and process Methods 0.000 description 2
- 238000000206 photolithography Methods 0.000 description 2
- WGTYBPLFGIVFAS-UHFFFAOYSA-M tetramethylammonium hydroxide Chemical compound [OH-].C[N+](C)(C)C WGTYBPLFGIVFAS-UHFFFAOYSA-M 0.000 description 2
- 241000252506 Characiformes Species 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- FFBHFFJDDLITSX-UHFFFAOYSA-N benzyl N-[2-hydroxy-4-(3-oxomorpholin-4-yl)phenyl]carbamate Chemical compound OC1=C(NC(=O)OCC2=CC=CC=C2)C=CC(=C1)N1CCOCC1=O FFBHFFJDDLITSX-UHFFFAOYSA-N 0.000 description 1
- 239000000872 buffer Substances 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 230000008094 contradictory effect Effects 0.000 description 1
- 230000007123 defense Effects 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 238000001459 lithography Methods 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 239000010453 quartz Substances 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- 238000001039 wet etching Methods 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B81—MICROSTRUCTURAL TECHNOLOGY
- B81B—MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES
- B81B7/00—Microstructural systems; Auxiliary parts of microstructural devices or systems
- B81B7/0009—Structural features, others than packages, for protecting a device against environmental influences
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B81—MICROSTRUCTURAL TECHNOLOGY
- B81B—MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES
- B81B7/00—Microstructural systems; Auxiliary parts of microstructural devices or systems
- B81B7/02—Microstructural systems; Auxiliary parts of microstructural devices or systems containing distinct electrical or optical devices of particular relevance for their function, e.g. microelectro-mechanical systems [MEMS]
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B81—MICROSTRUCTURAL TECHNOLOGY
- B81C—PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS
- B81C1/00—Manufacture or treatment of devices or systems in or on a substrate
- B81C1/00015—Manufacture or treatment of devices or systems in or on a substrate for manufacturing microsystems
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L1/00—Measuring force or stress, in general
- G01L1/18—Measuring force or stress, in general using properties of piezo-resistive materials, i.e. materials of which the ohmic resistance varies according to changes in magnitude or direction of force applied to the material
-
- 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
- G01L9/02—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 ohmic resistance, e.g. of potentiometers, electric circuits therefor, e.g. bridges, amplifiers or signal conditioning
- G01L9/06—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 ohmic resistance, e.g. of potentiometers, electric circuits therefor, e.g. bridges, amplifiers or signal conditioning of piezo-resistive devices
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B81—MICROSTRUCTURAL TECHNOLOGY
- B81B—MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES
- B81B2201/00—Specific applications of microelectromechanical systems
- B81B2201/02—Sensors
- B81B2201/0264—Pressure sensors
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
Landscapes
- Engineering & Computer Science (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Computer Hardware Design (AREA)
- Manufacturing & Machinery (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- General Health & Medical Sciences (AREA)
- Toxicology (AREA)
- Measuring Fluid Pressure (AREA)
Abstract
The application belongs to the technical field of pressure sensors, and particularly relates to a pressure sensor chip which mainly comprises an n-type monocrystalline silicon substrate, a silicon dioxide oxide layer, an n-type silicon carbide sensitive resistor, a metal electrode and a metal wire. The silicon dioxide oxidation layer is positioned on the front side of the substrate, the n-type silicon carbide sensitive resistor is positioned on the front side of the silicon dioxide oxidation layer, the metal electrode and the metal wire are both positioned on the front side of the silicon dioxide oxidation layer, and the metal wire is electrically connected with the n-type silicon carbide sensitive resistor and the metal electrode. According to the pressure sensor chip, the silicon carbide is used as a sensitive resistor, and the pressure sensor chip can stably operate in a high-temperature and high-radiation environment by utilizing the excellent performance of silicon carbide piezoresistance; meanwhile, the monocrystalline silicon substrate is combined, the processing technology of the monocrystalline silicon substrate is more mature and simple, the cost is low, the monocrystalline silicon substrate is suitable for mass production, and the problem of high manufacturing cost of the conventional silicon carbide pressure sensor chip is solved.
Description
Technical Field
The application belongs to the technical field of pressure sensors, and particularly relates to a pressure sensor chip and a manufacturing method thereof.
Background
Microelectromechanical Systems (MEMS) are novel sensor technologies developed based on semiconductor manufacturing technology, and MEMS have the advantages of miniaturization, integration, intelligence, low cost, high performance, mass production and the like. As a first type of MEMS sensor for mass production, silicon piezoresistive pressure sensors have been widely used in various fields such as consumer electronics, biomedical, aerospace, and defense and military. Compared with other MEMS sensing principles, such as piezoelectric type, capacitive type and resonant type, the piezoresistive pressure sensor has the characteristics of simple and reliable structure, high precision, quick response, strong electromagnetic interference resistance and the like.
At present, the MEMS piezoresistive pressure sensor in the market is mainly made of silicon, and the silicon is used as the most commonly used semiconductor material, so that the processing technology is mature and efficient. However, silicon piezoresistance is limited by material properties, the forbidden band of silicon is narrow, PN junction leakage current can be aggravated at high temperature, and performance at high temperature is affected; the silicon has poor heat conduction performance, and the piezoresistance temperature can be increased after long-time operation; the piezoresistive coefficient of silicon is greatly affected by temperature, and the sensitivity is greatly reduced at high temperature. The main structure of the piezoresistive pressure sensor is divided into two parts: the pressure-sensitive diaphragm and the piezoresistor (piezoresistor for short) on the diaphragm bear the pressure, when the pressure acts on the sensitive diaphragm, the diaphragm deforms and applies stress to the piezoresistor, and the pressure is obtained by measuring the change of the piezoresistor through the bridge circuit.
Silicon carbide is used as a third-generation semiconductor material, has the excellent characteristics of stable chemical property, high heat conductivity coefficient, small thermal expansion coefficient, wide forbidden band, high electron mobility, irradiation resistance and the like, and is an ideal material for manufacturing piezoresistive pressure sensors. However, silicon carbide is much more difficult to process than silicon, whether it is silicon carbide wafer fabrication or etching, and therefore results in high cost pressure sensor chips fabricated using silicon carbide.
Disclosure of Invention
The application provides a pressure sensor chip and a manufacturing method thereof, which are used for solving the problem of high manufacturing cost of the existing silicon carbide pressure sensor chip.
The application provides a pressure sensor chip, comprising:
a substrate which is an n-type monocrystalline silicon substrate;
the silicon dioxide oxide layer is positioned on the front surface of the substrate;
the n-type silicon carbide sensitive resistor is positioned on the front surface of the silicon dioxide oxide layer;
the metal electrode is positioned on the front surface of the silicon dioxide oxide layer;
and the metal wire is positioned on the front surface of the silicon dioxide oxide layer and is electrically connected with the n-type silicon carbide sensitive resistor and the metal electrode.
According to the pressure sensor chip, the silicon carbide is used as the sensitive resistor, and the silicon carbide piezoresistor has the excellent performances of high temperature resistance and high radiation resistance, so that the manufactured pressure sensor chip can stably operate in a high-temperature and high-radiation environment; meanwhile, the monocrystalline silicon substrate is combined, the processing technology of the monocrystalline silicon substrate is more mature and simple, the cost is low, the monocrystalline silicon substrate is suitable for mass production, and the problem of high manufacturing cost of the conventional silicon carbide pressure sensor chip is solved.
In an embodiment, the pressure sensor chip further includes a silicon nitride passivation layer, where the silicon nitride passivation layer is located on the front surface of the silicon oxide layer and the n-type silicon carbide sensitive resistor; the silicon nitride passivation layer is provided with a contact window on the front surface of the n-type silicon carbide sensitive resistor, and the metal wire is electrically connected with the n-type silicon carbide sensitive resistor through the contact window.
In the technical scheme of an embodiment, a groove is formed in the back surface of the substrate, a raised silicon island is arranged in the center of the groove, and the substrate corresponding to the annular cavity formed by the silicon island and the groove is a sensitive membrane.
In the technical scheme of one embodiment, the substrate is square, and the groove is positioned at the center of the substrate; the groove bottom and the groove opening of the groove are square, the square area of the groove opening is larger than that of the groove bottom, and the orthographic projection of the square of the groove bottom on the square of the groove opening and the square of the groove opening are used for sharing the circle center of an inscribed circle; the bottom surface and the top surface of the silicon island are square, the area of the bottom surface square is larger than that of the top surface square, and the orthographic projection of the top surface square on the bottom surface square and the bottom surface square are inscribed in the circle center.
In an embodiment, the front surface and the back surface of the substrate are both provided with a silicon dioxide oxide layer.
In the technical scheme of one embodiment, the pressure sensor chip comprises four n-type silicon carbide sensitive resistors and four metal electrodes, and the four n-type silicon carbide sensitive resistors and the four metal electrodes are connected in a cross manner through metal wires to form a closed circuit; four n-type silicon carbide sensitive resistors are distributed at the sensitive membrane, and four metal electrodes are respectively positioned at four corners of the substrate.
A method of manufacturing a pressure sensor chip, comprising the steps of:
preparing an n-type monocrystalline silicon substrate;
oxidizing the surface of the n-type monocrystalline silicon substrate to generate a silicon dioxide oxide layer;
depositing an n-type silicon carbide layer on the silicon dioxide oxide layer on the front surface of the n-type monocrystalline silicon substrate;
etching an n-type silicon carbide sensitive resistor on the n-type silicon carbide layer;
etching a groove and a silicon island at the back of an n-type monocrystalline silicon substrate;
and sequentially depositing nickel, titanium and gold on the silicon dioxide oxide layer on the front surface of the n-type monocrystalline silicon substrate through evaporation coating to form a metal layer, and stripping and forming a metal electrode and a metal wire.
In one embodiment, after the metal electrode and the metal wire are stripped, the metal electrode and the metal wire are subjected to thermal annealing treatment in an argon atmosphere at 1000 ℃ for 20 minutes.
In the technical scheme of one embodiment, after etching an n-type silicon carbide sensitive resistor, depositing a silicon nitride passivation layer on a silicon dioxide oxide layer on the front surface of an n-type monocrystalline silicon substrate and the n-type silicon carbide sensitive resistor; and etching the silicon nitride passivation layer on the front surface of the n-type silicon carbide sensitive resistor to release the contact window.
Drawings
The drawings in the present application are intended to illustrate preferred embodiments and to facilitate a clear understanding of various other advantages and benefits by those of ordinary skill in the art and are not to be considered limiting of the present application. Also, like reference numerals are used to designate like parts throughout the accompanying drawings.
Fig. 1 is a schematic perspective view of a pressure sensor chip according to an embodiment of the present application.
Fig. 2 is a schematic cross-sectional view of a pressure sensor chip in an embodiment of the present application.
Fig. 3 is a schematic diagram of a process 1 of a method for manufacturing a pressure sensor chip according to an embodiment of the present application.
Fig. 4 is a schematic diagram of a process 3 of a method for manufacturing a pressure sensor chip according to an embodiment of the present application.
Fig. 5 is a schematic diagram of a process 4 of a method for manufacturing a pressure sensor chip according to an embodiment of the present application.
Fig. 6 is a schematic diagram of a process 5 of a method for manufacturing a pressure sensor chip according to an embodiment of the present application.
Fig. 7 is a schematic diagram of a process 6 of a method for manufacturing a pressure sensor chip according to an embodiment of the present application.
Fig. 8 is a schematic diagram of a process 7 of a method for manufacturing a pressure sensor chip according to an embodiment of the present application.
Fig. 9 is a schematic diagram of a process 8 of a method for manufacturing a pressure sensor chip according to an embodiment of the present application.
Fig. 10 is a schematic diagram of a process 9 of a method for manufacturing a pressure sensor chip according to an embodiment of the present application.
Reference numerals illustrate:
1. a substrate; 2. a silicon dioxide oxide layer; 3. an n-type silicon carbide sensitive resistor; 4. a metal electrode; 5. a metal wire; 6. a silicon nitride passivation layer; 7. a groove; 8. a silicon island; 9. a sensitive membrane; 10. and a contact window.
Detailed Description
The technical solutions in the embodiments of the present application will be clearly and completely described below in connection with specific embodiments. It will be apparent that the described embodiments are only some, but not all, of the embodiments of the present application. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present disclosure.
Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of skill in the art will explicitly and implicitly appreciate that the embodiments described herein may be combined with other embodiments.
In the description of the embodiments of the present application, the orientation or positional relationship indicated by the technical terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are based on the orientation or positional relationship shown in the drawings, and are merely for convenience of describing the embodiments of the present application and for simplifying the description, rather than indicating or implying that the apparatus or element referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the embodiments of the present application.
In the description of the embodiments of the present application, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured" and the like are to be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally formed; or may be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the embodiments of the present application will be understood by those of ordinary skill in the art according to the specific circumstances.
Referring to fig. 1-10, embodiments of the present application provide a pressure sensor chip for use in a pressure sensor. The pressure sensor chip comprises a substrate 1, a silicon dioxide oxide layer 2, an n-type silicon carbide sensitive resistor 3, a metal electrode 4 and a metal wire 5. The substrate 1 is an n-type monocrystalline silicon substrate, the silicon dioxide oxide layer 2 is positioned on the front side of the substrate 1, the n-type silicon carbide sensitive resistor 3 is positioned on the front side of the silicon dioxide oxide layer 2, the metal electrode 4 and the metal wire 5 are both positioned on the front side of the silicon dioxide oxide layer 2, and the metal wire 5 is electrically connected with the n-type silicon carbide sensitive resistor 3 and the metal electrode 4. According to the pressure sensor chip, silicon carbide is used as a sensitive resistor, and the silicon carbide piezoresistor has the excellent performances of high temperature resistance and high radiation resistance, so that the manufactured pressure sensor chip can stably operate in a high-temperature and high-radiation environment; meanwhile, the monocrystalline silicon substrate is combined, the processing technology of the monocrystalline silicon substrate is more mature and simple, the cost is low, the monocrystalline silicon substrate is suitable for mass production, and the problem of high manufacturing cost of the conventional silicon carbide pressure sensor chip is solved.
Referring to fig. 7-9, in some embodiments, a silicon nitride passivation layer 6 is deposited on the front sides of the silicon dioxide oxide layer 2 and the n-type silicon carbide sensing resistor 3, the silicon nitride passivation layer 6 is provided with a contact window 10 on the front side of the n-type silicon carbide sensing resistor 3, and the metal wire 5 is electrically connected with the n-type silicon carbide sensing resistor 3 through the contact window 10. By providing the silicon nitride passivation layer 6, oxidation of the pressure sensor chip can be prevented, delaying the lifetime.
Referring to fig. 2, in some embodiments, a groove 7 is formed on the back of the substrate 1, a raised silicon island 8 is arranged in the center of the groove, the substrate 1 corresponding to the annular cavity formed by the silicon island 8 and the groove 7 is a sensitive membrane 9, and the n-type silicon carbide sensitive resistor 3 is located at the sensitive membrane 9. By arranging the silicon islands 8 in the grooves 7, the area of the sensitive membrane 9 is reduced, so that stress distribution is more concentrated, and the sensitivity and linearity of the sensor are enhanced.
In particular, in the embodiment shown in fig. 2, the substrate 1 is square and the recess 7 is located in the center of the substrate 1. The groove bottom and the groove opening of the groove 7 are square, the square area of the groove opening is larger than the square area of the groove bottom, and the orthographic projection of the square of the groove bottom on the square of the groove opening and the square of the groove opening are used for inscribing the circle center; the bottom surface and the top surface of the silicon island 8 are square, the area of the bottom surface square is larger than that of the top surface square, and the orthographic projection of the top surface square on the bottom surface square and the bottom surface square are in common inscription with the circle center.
In the embodiment shown in fig. 1, the pressure sensor chip specifically comprises four n-type silicon carbide sensitive resistors 3 and four metal electrodes 4, and the four n-type silicon carbide sensitive resistors 3 and the four metal electrodes 4 are connected in a cross manner through metal wires 5 to form a closed circuit; four n-type silicon carbide sensitive resistors 3 are distributed at the sensitive membrane 9, and four metal electrodes 4 are respectively positioned at four corners of the substrate 1.
Referring to fig. 3-10, in some embodiments, a pressure sensor chip manufacturing method includes the steps of:
step 1: spare sheet
Preparing silicon wafers: the n-type monocrystalline silicon wafer is used as an n-type monocrystalline silicon substrate, the thickness of the n-type monocrystalline silicon substrate is 350 mu m, the thickness of the silicon wafer is measured, and the quality problem of the silicon wafer is checked.
Step 2: cleaning
The n-type monocrystalline silicon wafer is immersed in Piranha solution at 120 ℃ for 20 minutes, and organic matters and metals are removed. Standard RCA cleaning is then performed to further remove particulate, organic and metal contamination.
And step 3: thermal oxidation (Thermal Oxidation)
And using a quartz boat to drive the n-type monocrystalline silicon wafer into an oxidation diffusion furnace, and generating a silicon dioxide oxide layer 2 with the thickness of about 0.4 mu m on the surface of the n-type monocrystalline silicon wafer at 1150 ℃, wherein the silicon dioxide oxide layer 2 on the top layer is used as a buffer insulating layer, and the silicon dioxide oxide layer 2 on the bottom layer can be used as a mask for back etching.
And 4, step 4: depositing device layers
An n-type silicon carbide layer having a thickness of about 1.2 μm was deposited on the top silicon dioxide oxide layer 2 using a PECVD apparatus (Plasma Enhanced Chemical Vapor Deposition, plasma-enhanced chemical vapor deposition). The nitrogen doping concentration of the n-type silicon carbide layer is about 5 x 1018cm-3.
And step 5: photolithography and etching
And after the n-type silicon carbide layer is coated with the adhesive, aligning and exposing by using a designed mask plate (designed according to the shape of the sensitive resistor), and finally developing to obtain the mask layer. And etching the n-type silicon carbide layer by using ICP equipment (Inductively Coupled Plasma ), wherein the etching depth is 1200nm, the etching rate is 220nm/min, and the n-type silicon carbide sensitive resistor 3 with a designed shape is formed on the n-type silicon carbide layer, as shown in figure 1.
And step 6: depositing a passivation layer
A PECVD apparatus is used to deposit 400nm thick silicon nitride as passivation layer, i.e. silicon nitride passivation layer 6, on top of the wafer.
Step 7: backside lithography and etching
And etching a silicon dioxide layer on the back of the silicon wafer by using a hydrofluoric acid buffer solution according to the shapes of the grooves 7 and the silicon islands 8, and etching the back grooves 7 and the silicon islands 8 by using tetramethyl ammonium hydroxide.
Step 8: photolithography and etching
And etching the passivation layer at the corresponding position of the n-type silicon carbide sensitive resistor 3 by using a hydrofluoric acid buffer solution to release the ohmic contact window 10.
Step 9: guide way
Ni (150 nm thick), ti (100 nm thick) and Au (50 nm thick) metal layers are sequentially deposited on the top layer through evaporation coating, and the metal electrode 4 and the metal wire 5 shown in FIG. 1 are formed through stripping, so that the pressure sensor chip is manufactured. In order to obtain good ohmic contact, a rapid thermal anneal may also be performed in an argon atmosphere at 1000 c for 20 minutes.
According to the manufacturing process of the pressure sensor chip, silicon carbide is selected as a sensitive resistor, and the silicon carbide piezoresistor has the excellent performances of high temperature resistance and high radiation resistance, so that the manufactured pressure sensor chip can stably operate in a high-temperature and high-radiation environment; meanwhile, the monocrystalline silicon substrate is combined, the processing technology of the monocrystalline silicon substrate is more mature and simple, the cost is low, the monocrystalline silicon substrate is suitable for mass production, and the problem of high manufacturing cost of the conventional silicon carbide pressure sensor chip is solved.
Step 10: packaging
And bonding the pressure sensor chip on a glass substrate, forming a back hole on the glass substrate, communicating with the groove 7, and finally packaging and connecting the bridge circuit integrally to finish the manufacturing of the pressure sensor.
In summary, the advantages of easy processing of the silicon diaphragm and strong piezoresistance stability of the silicon carbide are mainly combined, and the high-performance piezoresistance type pressure sensor for high temperature, which can be easily processed, is beneficial to mass production and improves sensitivity and nonlinearity.
In summary, the recess 7 is formed by wet etching, in order to thin a thick silicon wafer into a thin film (sensitive membrane 9) with higher sensitivity. The addition of the silicon islands 8 improves the local rigidity of the diaphragm (sensitive diaphragm 9) and changes the position of the stress concentration region compared with the common film without the silicon islands, so that the flexibility of the sensitive diaphragm 9 and the measured pressure are easier to keep a linear relation (the flexibility of the film with high rigidity is smaller under the same pressure, and the film is in a linear deformation region as known by a small flexibility theory small deflection theory). In addition, the piezoresistors are separated in stress concentration areas on two sides of the silicon island 8 (the silicon island changes stress distribution, so that the layout of the piezoresistors is different from that of a common film without the silicon island), the influence of processing errors is smaller, and therefore, the silicon island 8 greatly improves the linear output of the sensor.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present application, and are not limited thereto. Although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the embodiments, and are intended to be included within the scope of the claims and description. In particular, the technical features mentioned in the respective embodiments may be combined in any manner as long as there is no contradictory conflict. The present application is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions falling within the scope of the claims.
Claims (9)
1. A pressure sensor chip, comprising:
a substrate which is an n-type monocrystalline silicon substrate;
the silicon dioxide oxide layer is positioned on the front surface of the substrate;
the n-type silicon carbide sensitive resistor is positioned on the front surface of the silicon dioxide oxide layer;
the metal electrode is positioned on the front surface of the silicon dioxide oxide layer;
and the metal wire is positioned on the front surface of the silicon dioxide oxide layer and is electrically connected with the n-type silicon carbide sensitive resistor and the metal electrode.
2. The pressure sensor chip of claim 1, further comprising a silicon nitride passivation layer on the silicon dioxide oxide layer and n-type silicon carbide sense resistor front side; the silicon nitride passivation layer is provided with a contact window on the front surface of the n-type silicon carbide sensitive resistor, and the metal wire is electrically connected with the n-type silicon carbide sensitive resistor through the contact window.
3. The pressure sensor chip of claim 1, wherein a groove is formed in the back surface of the substrate, a raised silicon island is arranged in the center of the groove, and the substrate corresponding to the annular cavity formed by the silicon island and the groove is a sensitive membrane.
4. A pressure sensor chip according to claim 3, wherein the substrate is square and the recess is located at a central position of the substrate; the groove bottom and the groove opening of the groove are square, the square area of the groove opening is larger than that of the groove bottom, and the orthographic projection of the square of the groove bottom on the square of the groove opening and the square of the groove opening are used for sharing the circle center of an inscribed circle; the bottom surface and the top surface of the silicon island are square, the area of the bottom surface square is larger than that of the top surface square, and the orthographic projection of the top surface square on the bottom surface square and the bottom surface square are inscribed in the circle center.
5. The pressure sensor chip of claim 1, wherein the front and back surfaces of the substrate each have a silicon dioxide oxide layer.
6. The pressure sensor chip of claim 1, wherein the pressure sensor chip comprises four of the n-type silicon carbide sensing resistors and four of the metal electrodes, and the four of the n-type silicon carbide sensing resistors and the four of the metal electrodes are cross-connected into a closed circuit through metal wires; four n-type silicon carbide sensitive resistors are distributed at the sensitive membrane, and four metal electrodes are respectively positioned at four corners of the substrate.
7. A method of manufacturing a pressure sensor chip, comprising:
preparing an n-type monocrystalline silicon substrate;
oxidizing the surface of the n-type monocrystalline silicon substrate to generate a silicon dioxide oxide layer;
depositing an n-type silicon carbide layer on the silicon dioxide oxide layer on the front surface of the n-type monocrystalline silicon substrate;
etching an n-type silicon carbide sensitive resistor on the n-type silicon carbide layer;
etching a groove and a silicon island at the back of an n-type monocrystalline silicon substrate;
and sequentially depositing nickel, titanium and gold on the silicon dioxide oxide layer on the front surface of the n-type monocrystalline silicon substrate through evaporation coating to form a metal layer, and stripping and forming a metal electrode and a metal wire.
8. The method of manufacturing a pressure sensor chip according to claim 7, wherein after the metal electrode and the metal wire are peeled off, the metal electrode and the metal wire are subjected to a thermal annealing treatment in an argon atmosphere at 1000 ℃ for 20 minutes.
9. The method of manufacturing a pressure sensor chip according to claim 7, wherein after etching the n-type silicon carbide sensing resistor, a silicon nitride passivation layer is deposited on the silicon oxide layer on the front surface of the n-type single crystal silicon substrate and the n-type silicon carbide sensing resistor; and etching the silicon nitride passivation layer on the front surface of the n-type silicon carbide sensitive resistor to release the contact window.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310630028.2A CN116553471A (en) | 2023-05-30 | 2023-05-30 | Pressure sensor chip and manufacturing method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310630028.2A CN116553471A (en) | 2023-05-30 | 2023-05-30 | Pressure sensor chip and manufacturing method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116553471A true CN116553471A (en) | 2023-08-08 |
Family
ID=87501764
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310630028.2A Pending CN116553471A (en) | 2023-05-30 | 2023-05-30 | Pressure sensor chip and manufacturing method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116553471A (en) |
-
2023
- 2023-05-30 CN CN202310630028.2A patent/CN116553471A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5165283A (en) | High temperature transducers and methods of fabricating the same employing silicon carbide | |
| JP3114570B2 (en) | Capacitive pressure sensor | |
| KR100812996B1 (en) | Micro gas sensor and method for manufacturing the same | |
| US6948374B2 (en) | Capacitive pressure sensor and its manufacturing method | |
| WO2017028466A1 (en) | Mems strain gauge chip and manufacturing process therefor | |
| US20100140725A1 (en) | Pressure sensor | |
| JPS6313356B2 (en) | ||
| JP2560140B2 (en) | Semiconductor device | |
| CN114275731A (en) | MEMS-based double-beam type micro-pressure sensing core and preparation process thereof | |
| US11401156B2 (en) | Micro-electro-mechanical system silicon on insulator pressure sensor and method for preparing same | |
| CN115127630B (en) | Preparation method of double-shaft multidirectional MEMS thermal flow sensor | |
| CN103364120A (en) | Silver-tin eutectic vacuum bonding metal variant-type MEMS pressure transistor and manufacturing method thereof | |
| CN219823665U (en) | Pressure sensor chip | |
| JP3191770B2 (en) | Semiconductor acceleration sensor and method of manufacturing the same | |
| CN112284605A (en) | Cross island beam membrane high-temperature micro-pressure sensor chip and preparation method thereof | |
| CN116553471A (en) | Pressure sensor chip and manufacturing method | |
| CN216559443U (en) | MEMS substrate and MEMS pressure sensor | |
| CN115285929A (en) | Micro-differential pressure type MEMS pressure sensor pressure-sensitive chip and preparation method thereof | |
| JPH0554708B2 (en) | ||
| JP2007033304A (en) | Production method of pressure sensor | |
| JPS59169184A (en) | Manufacture of pressure sensor | |
| CN215217879U (en) | MEMS piezoresistive pressure sensor | |
| CN112284606B (en) | T-shaped cross beam cross island membrane pressure sensor chip and preparation method thereof | |
| JPH07318445A (en) | Capacitance type pressure sensor and manufacture thereof | |
| JPH03208375A (en) | Semiconductor pressure sensor |
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 |