Vacuum degree sensor and manufacturing method thereof

Abstract

The invention discloses a vacuum degree sensor and a manufacturing method thereof, relates to the technical field of vacuum pressure measurement, and aims to solve the problem that an existing Pirani vacuum sensor is small in measurement range. The vacuum degree sensor comprises a substrate, a first supporting layer, a thermistor and a passivation layer. The substrate has an insulating cavity, and the first support layer is formed on a first side of the substrate. The thermistor is formed on the surface of the first support layer away from the substrate. The passivation layer covers the first support layer and the thermistor. Wherein a laminated structure formed by the first supporting layer and the passivation layer comprises a connecting structure corresponding to the substrate, a heat exchange structure provided with a thermistor and a cantilever beam used for connecting the heat exchange structure and the connecting structure; the cantilever beam and the heat exchange structure are both located above the heat insulation cavity. At least one through hole is formed in the cantilever beam in the direction from the first supporting layer to the passivation layer, the through hole penetrates through the cantilever beam, and the through hole communicates with the heat insulation cavity.

Description

Technical Field

[0001] The present invention relates to the technical field of vacuum pressure measurement, and in particular to a vacuum degree sensor and a manufacturing method thereof. Background Art

[0002] Pirani vacuum sensor is a type of thermal conduction vacuum sensor. Its working principle is: the heat conducted by the surrounding gas to the heated object included in the Pirani vacuum sensor changes with the air pressure. Based on this, through the principle of thermoelectric coupling, the relationship between electrical response and vacuum degree is established, thereby realizing the pressure monitoring of the vacuum environment. Pirani vacuum sensor has the advantages of small size, low cost, low energy consumption and fast response, and is widely used in vacuum degree monitoring of various sizes of vacuum packages and micro cavities.

[0003] However, the existing Pirani vacuum sensor has a small measuring range. Summary of the invention

[0004] The object of the present invention is to provide a vacuum sensor and a manufacturing method thereof, so as to expand the measuring range of the vacuum sensor.

[0005] In order to achieve the above-mentioned purpose, in the first aspect, the present invention provides a vacuum sensor. The vacuum sensor includes a substrate, a first supporting layer, a thermistor and a passivation layer. The substrate has an insulating cavity, the substrate has a first surface and a second surface opposite to each other, and the first supporting layer is formed on the first surface of the substrate. The thermistor is formed on a surface of the first supporting layer away from the substrate, and the passivation layer covers the first supporting layer and the thermistor. Among them, the stacked structure formed by the first supporting layer and the passivation layer includes a connecting structure corresponding to the substrate, a heat exchange structure provided with a thermistor, and a cantilever beam for connecting the heat exchange structure and the connecting structure; the cantilever beam and the heat exchange structure are both located above the insulating cavity. Along the direction from the first supporting layer to the passivation layer, at least one through hole is opened on the cantilever beam, the through hole passes through the cantilever beam, and the through hole is connected to the insulating cavity.

[0006] Compared with the prior art, in the vacuum sensor provided by the present invention, at least one through hole is provided on the cantilever beam along the direction from the first supporting layer to the passivation layer, the through hole penetrates the cantilever beam, and the through hole is connected to the heat-insulating cavity. In actual operation, heat can be conducted out through the cantilever beam and the heat exchange structure, but the heat cannot be directly dissipated through the through hole. At the position where the through hole is provided, the heat can only be conducted out along the side wall of the through hole (i.e., the cantilever beam), and the heat transmission path is extended at this time. Based on this, the through hole provided on the cantilever beam increases the thermal resistance of the cantilever beam while ensuring the strength of the cantilever beam, effectively reducing the heat conduction of the cantilever beam, thereby expanding the measurement range of the vacuum sensor, especially expanding the measurement range of the vacuum sensor in the high vacuum direction, and also improving the measurement sensitivity of the vacuum sensor, and improving the accuracy of the measurement results.

[0007] In one implementation, the cross-sectional shape of the through hole is an ellipse or a circle or a closed figure formed by an arc and a line segment.

[0008] In one implementation, the first supporting layer has at least one protrusion and / or at least one recess; the passivation layer is conformally formed on the first supporting layer and the thermistor.

[0009] In one implementation, along the direction from the first supporting layer to the passivation layer, the cross-sectional shape of the raised portion is a closed figure consisting of a triangle, a trapezoid, a rectangle, or an arc and a line segment; the cross-sectional shape of the recessed portion is a closed figure consisting of a triangle, a trapezoid, a rectangle, or an arc and a line segment.

[0010] In one implementation, the base is a substrate; along the height direction of the substrate, the thermal insulation cavity penetrates the substrate;

[0011] Alternatively, the base includes a substrate and a second supporting layer disposed on the substrate; the thermal insulation cavity penetrates the second supporting layer along a direction from the second supporting layer to the substrate; and the first supporting layer is formed on the second supporting layer.

[0012] In one implementation, the material of the first support layer includes one or more of silicon oxide, silicon nitride, and silicon oxynitride;

[0013] The material of the passivation layer includes one or more of silicon oxide, silicon nitride, and silicon oxynitride;

[0014] The material of the thermistor includes one or more of metal alloy, nickel, tungsten, platinum, titanium, and cobalt; or, the material of the thermistor includes polysilicon, vanadium oxide, or ceramic.

[0015] In a second aspect, the present invention further provides a method for manufacturing a vacuum sensor. The method for manufacturing the vacuum sensor comprises:

[0016] Providing a substrate; the substrate has a first surface and a second surface opposite to each other;

[0017] forming a first supporting layer on the first surface of the substrate;

[0018] forming a thermistor on a surface of the first supporting layer away from the substrate;

[0019] forming a passivation layer on the first support layer and the thermistor;

[0020] At least one through hole is opened on the first supporting layer and the passivation layer along the direction from the first supporting layer to the passivation layer; the through hole penetrates the first supporting layer and the passivation layer at the same time;

[0021] Processing the substrate along the height direction of the substrate so that the substrate has a thermally insulating cavity;

[0022] Among them, the stacked structure formed by the first supporting layer and the passivation layer includes a connecting structure corresponding to the substrate, a heat exchange structure provided with a thermistor, and a cantilever beam for connecting the heat exchange structure and the connecting structure; the cantilever beam and the heat exchange structure are both located above the insulating cavity; the through holes are both located on the cantilever beam, and the through holes are connected to the insulating cavity.

[0023] Compared with the prior art, the beneficial effects of the manufacturing method of the vacuum sensor provided by the present invention are the same as the beneficial effects of the vacuum sensor described in the above technical solution, which will not be described in detail here.

[0024] In one implementation, before forming the first supporting layer on the first surface of the substrate, the method for manufacturing the vacuum sensor further includes:

[0025] Etching the first surface of the substrate so that the substrate has a plurality of grooves distributed at intervals;

[0026] And / or, a protrusion structure material layer is deposited on the first surface of the substrate to form a plurality of protrusion structures distributed at intervals on the first surface of the substrate.

[0027] In one implementation, a first supporting layer is conformally formed on the first surface of the substrate; and the passivation layer is conformally formed on the first supporting layer and the thermistor.

[0028] In one implementation, when the base is a substrate, processing the base along the height direction of the base so that the base has a thermal insulation cavity comprises: etching the substrate along the height direction of the substrate so that the substrate has a thermal insulation cavity, wherein the thermal insulation cavity penetrates the substrate;

[0029] When the base includes a substrate and a second supporting layer arranged on the substrate, the first supporting layer is formed on a surface of the second supporting layer away from the substrate; along the height direction of the substrate, processing the substrate so that the substrate has an insulating cavity includes: etching the second supporting layer along the direction from the second supporting layer to the substrate so that the second supporting layer has an insulating cavity, and the insulating cavity penetrates the second supporting layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0031] Figure 1 is a cross-sectional view of a first vacuum degree sensor according to an embodiment of the present invention;

[0032] Figure 2 is a cross-sectional view of a second vacuum sensor according to an embodiment of the present invention;

[0033] Figure 3 A top view of a partial structure of the first or second vacuum degree sensor in an embodiment of the present invention;

[0034] Figure 4 A cross-sectional view of the first vacuum sensor manufactured in an embodiment of the present invention Figure 1 ;

[0035] Figure 5 A cross-sectional view of the first vacuum sensor manufactured in an embodiment of the present invention Figure 2 ;

[0036] Figure 6 A cross-sectional view of the first vacuum sensor manufactured in an embodiment of the present invention Figure 3 ;

[0037] Figure 7 A cross-sectional view of the first vacuum sensor manufactured in an embodiment of the present invention Figure 4 ;

[0038] Figure 8 A cross-sectional view of the first vacuum sensor manufactured in an embodiment of the present invention Figure 5 ;

[0039] Fig. 9 A cross-sectional view of the first vacuum sensor manufactured in an embodiment of the present invention Figure 6 ;

[0040] Fig.10 A cross-sectional view of the first vacuum sensor manufactured in an embodiment of the present invention Figure 7 ;

[0041] Fig.11 A cross-sectional view of the second vacuum sensor manufactured in the embodiment of the present invention Figure 1 ;

[0042] Fig.12 A cross-sectional view of the second vacuum sensor manufactured in the embodiment of the present invention Figure 2 ;

[0043] Fig.13 A cross-sectional view of the second vacuum sensor manufactured in the embodiment of the present invention Figure 3 ;

[0044] Fig.14 A cross-sectional view of the second vacuum sensor manufactured in the embodiment of the present invention Figure 4 ;

[0045] Fig.15A cross-sectional view of the second vacuum sensor manufactured in the embodiment of the present invention Figure 5 ;

[0046] Fig.16 A cross-sectional view of the second vacuum sensor manufactured in the embodiment of the present invention Figure 6 .

[0047] Reference numerals:

[0048] 1-base, 10-substrate, 11-second supporting layer, 12-insulating cavity; 2-first supporting layer, 20-first recess; 3-thermistor, 4-passivation layer, 40-second recess; 5-connecting structure, 6-heat exchange structure, 7-cantilever beam, 70-through hole; 8-frame, 9-groove. DETAILED DESCRIPTION

[0049] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0050] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0051] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined. The meaning of "several" is one or more, unless otherwise clearly and specifically defined.

[0052] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by the terms "up", "down", "front", "back", "left", "right", etc. are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0053] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0054] Vacuum detection is widely used in aerospace, industrial production, consumer electronics, food production, advanced material processing, semiconductors and other fields. Vacuum sensors, as the core components of vacuum detection, have great application potential.

[0055] A vacuum sensor is a sensor used to measure gas below one atmosphere. It usually uses the change of certain physical effects of gas under different air pressures to measure air pressure, and is widely used in scientific research and industrial production. Specifically, vacuum sensors are divided into capacitive film vacuum sensors, resonant vacuum sensors, thermal conduction vacuum sensors, ionization vacuum sensors, etc.

[0056] Among them, the Pirani vacuum sensor is a type of thermal conductivity vacuum sensor. When the Pirani vacuum sensor is in working state, the heating resistor can heat the suspension structure so that the temperature of the suspension structure is higher than the ambient temperature. At this time, the heat consumption of the suspension structure includes gas thermal conductivity heat dissipation, radiation heat dissipation and solid heat dissipation. Based on this, because the thermal conductivity of the gas changes with the change of pressure, the above-mentioned gas thermal conductivity heat dissipation is related to the vacuum degree of the vacuum environment. Through the principle of thermoelectric coupling, the relationship between electrical response and vacuum degree is established, thereby realizing pressure monitoring of the vacuum environment. Pirani vacuum sensors have the advantages of small size, low cost, low energy consumption and fast response, and are widely used in vacuum degree monitoring of vacuum packages of various sizes and micro cavities.

[0057] In the prior art, the following scheme is generally used for detection from atmospheric pressure to high vacuum.

[0058] The first method is to use a single MEMS (Micro-Electro-Mechanical System) Pirani vacuum sensor. However, the existing MEMS Pirani vacuum sensor has a small measurement range, which causes the Pirani vacuum sensor to have a sensitivity attenuation problem when it is close to the end of the range on the atmospheric pressure side and the high vacuum side, making it impossible to achieve a range from atmospheric pressure to high vacuum (10 -2 Pa to 10 -4 The accuracy of the measurement results decreases if the vacuum degree is lower than 200 Pa.

[0059] The second method: using MEMS Pirani vacuum sensor, or thin film capacitive vacuum sensitive structure and MEMS absolute pressure sensor for composite measurement. Using MEMS absolute pressure sensor to measure atmospheric pressure section, the detection accuracy can be within 2%. Using MEMS Pirani vacuum sensor or thin film capacitive vacuum sensitive structure to detect rough vacuum to high vacuum section, the accuracy can be within 2%. However, MEMS Pirani vacuum sensor or thin film capacitive vacuum sensitive structure has low detection accuracy for high vacuum section, and can only detect 10 -2 Pa level, and the detection accuracy is generally only greater than 15%, and the thin film capacitive sensitive structure has a small range. -2 Pa to 10 -4 The detection accuracy in the high vacuum range of Pa is lower and cannot meet the needs of actual applications.

[0060] The third method is to use ionized vacuum silicon. Although ionized vacuum silicon can detect 10 -9 The vacuum degree is above Pa and the sensitivity is high, but its large size and high power consumption limit its application in many application scenarios.

[0061] In order to solve at least part of the above technical problems, in a first aspect, an embodiment of the present invention provides a vacuum sensor. For example, the vacuum sensor may be a Pirani vacuum sensor.

[0062] See also Figures 1 to 3 The vacuum sensor comprises a substrate 1, a first support layer 2, a thermistor 3 and a passivation layer 4. The substrate 1 has an insulating cavity 12, the substrate 1 has a first surface and a second surface opposite to each other, and the first support layer 2 is formed on the first surface of the substrate 1. The thermistor 3 is formed on the surface of the first support layer 2 away from the substrate 1, and the passivation layer 4 covers the first support layer 2 and the thermistor 3. Among them, the stacked structure formed by the first support layer 2 and the passivation layer 4 includes a connection structure 5 corresponding to the substrate 1, a heat exchange structure 6 provided with the thermistor 3, and a cantilever beam 7 for connecting the heat exchange structure 6 and the connection structure 5, and the cantilever beam 7 and the heat exchange structure 6 are both located above the insulating cavity 12. Along the direction from the first support layer 2 to the passivation layer 4, at least one through hole 70 is opened on the cantilever beam 7, and the through hole 70 passes through the cantilever beam 7, and the through hole 70 is connected to the insulating cavity 12. It should be noted that the above-mentioned insulating cavity 12 may pass through the substrate 1, or may not pass through the substrate 1.

[0063] See also Figures 1 to 3In the vacuum sensor provided by the embodiment of the present invention, at least one through hole 70 is provided on the cantilever beam 7 along the direction from the first support layer 2 to the passivation layer 4, and the through hole 70 penetrates the cantilever beam 7, and the through hole 70 is connected to the heat-insulating cavity 12. In actual operation, the heat can be conducted out through the cantilever beam 7 and the heat exchange structure 6, but the heat cannot be directly dissipated through the through hole 70. At the position where the through hole 70 is provided, the heat can only be conducted out along the side wall of the through hole 70 (i.e., the cantilever beam 7), and the heat transmission path is extended at this time. Based on this, the through hole 70 provided on the cantilever beam 7 increases the thermal resistance of the cantilever beam 7 while ensuring the strength of the cantilever beam 7, effectively reducing the heat conduction of the cantilever beam 7, and thus can expand the measurement range of the vacuum sensor, especially expand the measurement range of the vacuum sensor in the high vacuum direction, and also improve the measurement sensitivity of the vacuum sensor, and improve the accuracy of the measurement result.

[0064] In actual application, the embodiment of the present invention does not specifically limit the structure and material of the above-mentioned substrate, as long as it can be applied to the vacuum sensor provided by the embodiment of the present invention.

[0065] As a possible implementation, see Figure 1 , the base 1 is a substrate 10. Along the height direction of the substrate 10, the heat-insulating cavity 12 penetrates the substrate 10. Exemplarily, the material of the substrate can be a semiconductor material or a non-semiconductor material. For example, the substrate can be a glass substrate, a silicon substrate, a sapphire substrate or a polymer substrate.

[0066] As another possible implementation, see Figure 2 The base 1 includes a substrate 10 and a second support layer 11 disposed on the substrate 10. Along the direction from the second support layer 11 to the substrate 10, the heat-insulating cavity 12 penetrates the second support layer 11, and the first support layer 2 is formed on the second support layer 11.

[0067] Exemplarily, the material of the substrate may be a semiconductor material or a non-semiconductor material. For example, the substrate may be a glass substrate, a silicon substrate, a sapphire substrate, or a polymer substrate.

[0068] The material of the second support layer may be an inorganic material or an organic material. For example, the second support layer may be a silicon second support layer, a silicon oxide second support layer, a polysilicon second support layer, an amorphous silicon second support layer or a polyimide second support layer. The thickness of the second support layer may be greater than or equal to 2 μm and less than or equal to 50 μm. For example, the thickness of the second support layer may be 2 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm or 50 μm.

[0069] As a possible implementation, see Figures 1 to 3 The vacuum sensor comprises four cantilever beams 7 and a heat exchange structure 6. The four cantilever beams 7 are respectively located at the four corners of the heat exchange structure 6. The base 1 and the connecting structure 5 located above the base 1 together form a frame 8. The heat exchange structure 6 is connected to the frame 8 through the cantilever beams 7. It should be noted that Figure 3 Only the first supporting layer 2 in the heat exchange structure 6 is shown.

[0070] The cross-sectional shape of the through hole can be an ellipse, a circle, a triangle, a rectangle, a square, a closed figure composed of an arc and a line segment, etc. In the embodiment of the present invention, see Figure 3 The cross-sectional shape of the through hole 70 is an ellipse or a circle or a closed figure formed by an arc and a line segment. Compared with the through hole 70 with a sharp corner (such as a rectangle or a square) in the cross-sectional shape, the through hole 70 in the embodiment of the present invention can make the mechanical strength of the cantilever beam 7 better, reduce stress concentration, and thus ensure the service life of the vacuum sensor.

[0071] As a possible implementation, see Figure 1 and Figure 2 , the heat exchange structure 6 has at least one protrusion and / or at least one recess. For example, see Figure 6 The first supporting layer 2 has at least one protrusion and / or at least one recess (defined as “first recess 20 ” here for the sake of distinction).

[0072] See also Figure 8 In the actual manufacturing process, the passivation layer 4 is conformally formed on the first supporting layer 2 and the thermistor 3. At this time, the passivation layer 4 also has at least one protrusion and / or at least one recess (defined as "second recess 40" here for the convenience of distinction). It should be noted that the height of the above-mentioned protrusion and the depth of the recess are not specifically limited here and can be set according to actual conditions. Furthermore, when the heat exchange structure 6 has multiple protrusions, the multiple protrusions are distributed at intervals. When the heat exchange structure 6 has multiple recesses, the multiple recesses are distributed at intervals. When the heat exchange structure 6 has multiple protrusions and recesses at the same time, the protrusions and recesses are distributed at intervals. In an embodiment of the present invention, relative to the first supporting layer 2 in the connecting structure 5, the first supporting layer 2 in the heat exchange structure 6 has multiple recesses distributed at intervals. Relative to the passivation layer 4 in the connecting structure 5, the passivation layer 4 in the heat exchange structure 6 has multiple recesses distributed at intervals.

[0073] When the above technical solution is adopted, the protrusions and / or depressions formed on the heat exchange structure can effectively increase the specific surface area of ​​the heat exchange structure, thereby improving the heat exchange capacity of the heat exchange structure under high vacuum. Combined with the above description, the through hole opened on the cantilever beam can effectively reduce the heat conduction of the cantilever beam. Based on this, the measurement range of the vacuum sensor can be expanded to achieve from atmospheric pressure to high vacuum (10 -2 Pa to 10- 4 The vacuum degree sensor provided by the embodiment of the present invention can measure the vacuum degree from atmospheric pressure to high vacuum (10 -2 Pa to 10- 4 The vacuum degree measurement of Pa) does not need to adopt multiple types of vacuum degree sensors for composite measurement, and the circuit is also simplified.

[0074] In an alternative approach, see Figure 1 and Figure 2 , along the direction from the first supporting layer 2 to the passivation layer 4, the cross-sectional shape of the protrusion is a closed figure consisting of a triangle, a trapezoid, a rectangle, or an arc and a line segment; the cross-sectional shape of the recess is a closed figure consisting of a triangle, a trapezoid, a rectangle, or an arc and a line segment. In the embodiment of the present invention, the cross-sectional shape of the recess is a trapezoid.

[0075] As a possible implementation, the material of the first support layer includes one or more of silicon oxide, silicon nitride, and silicon oxynitride. The material of the passivation layer includes one or more of silicon oxide, silicon nitride, and silicon oxynitride. It should be noted that the material of the first support layer and the material of the passivation layer may be the same or different. Furthermore, the first support layer (or passivation layer) may be a single film layer structure or a multi-film layer structure, which is not specifically limited here.

[0076] Thermistors can be used for heating and temperature measurement, and the signals of the thermistors are led out through the cantilever beam, for example, the thermistors are routed through the cantilever beam. As for the specific arrangement and connection relationship between the thermistors and the cantilever beam, no specific limitation is made here.

[0077] The material of the thermistor includes one or more of metal alloy, nickel, tungsten, platinum, titanium, and cobalt; or, the material of the thermistor includes polysilicon, vanadium oxide, or ceramic. Among them, the metal alloy can be understood as a material formed by mixing at least two different materials in different proportions. Exemplarily, the above-mentioned thermistor may include a layer of metal alloy, a layer of nickel, and a layer of tungsten. Alternatively, the thermistor may include only a layer of metal alloy. Alternatively, the thermistor may include a layer of nickel and a layer of tungsten.

[0078] It should be noted that the vacuum sensor also includes a pad, and the specific position of the pad, the material, the connection relationship between the pad and other structures, and the relative position relationship are not specifically limited here, and can be set according to actual conditions. For example, the material of the pad can be Au, TiN, Ti, or AL, etc.

[0079] In summary, the vacuum degree sensor provided by the embodiment of the present invention has a simple structure, low power consumption, and small size, and its application range can be expanded. It should be noted that Figure 1 and Figure 2 The cross-sectional view shown can be understood as a Figure 3 Schematic diagram after AA' section.

[0080] In a second aspect, an embodiment of the present invention further provides a method for manufacturing a vacuum sensor. Based on the different structural compositions of the substrate, the specific steps of the method for manufacturing the vacuum sensor are different. The following description is given by taking two cases as examples. It should be understood that the following description is only for understanding and is not intended to be a specific limitation.

[0081] See also Figures 4 to 10 , a first method for manufacturing a vacuum sensor includes:

[0082] First, see Figure 4 , providing a substrate 1; the substrate 1 has a first surface and a second surface opposite to each other;

[0083] The base 1 is the substrate 10. For the description of the substrate 10, please refer to the first aspect and will not be repeated here. Because the base 1 only includes the structure of the substrate 10 and does not include other film layers, the subsequent description uniformly uses "base 1".

[0084] Next, the first surface of the substrate 1 is etched to provide the substrate 1 with a plurality of grooves 9 distributed at intervals; and / or a convex structure material layer is deposited on the first surface of the substrate 1 to form a plurality of convex structures distributed at intervals on the first surface of the substrate 1 .

[0085] For example, after providing the substrate 1, wet chemical etching, plasma etching, laser etching or ultrasonic drilling can be used to selectively etch the substrate 1 to form a plurality of spaced grooves 9. Alternatively, a convex structure material layer is deposited on the first surface of the substrate 1 by a deposition process to form a plurality of spaced convex structures on the first surface of the substrate 1.

[0086] In the embodiments of the present invention, see Figure 5 The first surface of the substrate 1 is etched by an etching process so that the substrate 1 has a plurality of grooves 9 distributed at intervals. The depth of the grooves is not specifically limited herein.

[0087] Next, see Figure 6, forming a first supporting layer 2 on a first surface of the substrate 1;

[0088] Exemplarily, the first supporting layer 2 is conformally formed on the first surface of the substrate 1. When a groove or protrusion structure is formed on the substrate 1, the first supporting layer 2 conformally formed on the first surface of the substrate 1 also has a concave portion or a convex portion corresponding to the groove or protrusion structure of the substrate 1.

[0089] In the embodiments of the present invention, see Figure 5 and Figure 6 The first support layer 2 is conformally formed on the substrate 1 having a plurality of spaced grooves 9. In this case, the first support layer 2 has a plurality of spaced recesses corresponding to the grooves 9 on the substrate 1 (i.e., the recesses are arranged at intervals). Figure 6 The first recessed portion 20 in the embodiment of the present invention.

[0090] Next, see Figure 7 , forming a thermistor 3 on a surface of the first supporting layer 2 away from the substrate 1;

[0091] Exemplarily, a thermistor material layer can be formed as a whole layer on the side of the first support layer away from the substrate, and then the thermistor material layer can be patterned to form a thermistor. As for the specific processing process, please refer to the prior art and will not be described in detail here. The above-mentioned thermistor is formed in a non-depressed portion. Furthermore, the above-mentioned thermistor can be located above the insulating cavity formed later. For example, the thermistor is formed in a raised area relative to the depressed portion. It should be noted that the "raised area relative to the depressed portion" may be flush with the first support layer formed on the substrate (i.e., flush with the first support layer in the connection structure), or it may be raised relative to the first support layer formed on the substrate (i.e., raised relative to the first support layer in the connection structure). For other descriptions of the thermistor, please refer to the description of the first aspect, which is not specifically limited here.

[0092] Next, see Figure 8 , forming a passivation layer 4 on the first supporting layer 2 and the thermistor 3;

[0093] Exemplarily, the passivation layer is conformally formed on the first supporting layer and the thermistor. When the first supporting layer has a concave portion or a convex portion corresponding to the groove or convex structure of the substrate, the passivation layer conformally formed on the first supporting layer and the thermistor also has a concave portion or a convex portion corresponding to the first supporting layer.

[0094] In the embodiments of the present invention, see Figures 6 to 8 The passivation layer 4 is conformally formed on the thermistor 3 and the first support layer 2 having a plurality of recessed portions spaced apart. In this case, the passivation layer 4 has a shape similar to the recessed portions on the first support layer 2 (i.e., the recessed portions attached to the thermistor 3). Figure 6 The first recessed portion 20 in the middle corresponds to a plurality of recessed portions (i.e., the first recessed portion 20 in the middle) distributed at intervals. Figure 8 The second recessed portion 40 in the embodiment of the present invention.

[0095] Next, see Fig. 9 , along the direction from the first supporting layer 2 to the passivation layer 4, at least one through hole 70 is opened on the first supporting layer 2 and the passivation layer 4; the through hole 70 penetrates the first supporting layer 2 and the passivation layer 4 at the same time; before or after this step or synchronously with this step, a pad required later is formed. As for the specific formation process of the pad, please refer to the prior art and will not be described in detail here. For example, see Figure 3 In the embodiment of the present invention, for the four cantilever beams, each cantilever beam is provided with 5 through holes distributed at intervals.

[0096] Next, see Fig.10 , processing the substrate 1 along the height direction of the substrate 1 so that the substrate 1 has a heat-insulating cavity 12;

[0097] Exemplarily, along the height direction of the substrate, the substrate is etched so that the substrate has an insulating cavity, and the insulating cavity runs through the substrate. Specifically, the substrate 1 (i.e., the substrate 10 described above) can be processed by anisotropic wet etching or deep silicon etching, so that the substrate 1 (i.e., the substrate 10 described above) has an insulating cavity 12 running through the substrate 1 (i.e., the substrate 10 described above).

[0098] Among them, see Figure 1 The laminated structure formed by the first supporting layer 2 and the passivation layer 4 includes a connection structure 5 corresponding to the substrate 1, a heat exchange structure 6 provided with a thermistor 3, and a cantilever beam 7 for connecting the heat exchange structure 6 and the connection structure 5, and the cantilever beam 7 and the heat exchange structure 6 are both located above the heat insulating cavity 12. The through holes 70 are all located on the cantilever beam 7, and the through holes 70 are connected to the heat insulating cavity 12.

[0099] See also Figures 4 to 10In the vacuum sensor provided by the embodiment of the present invention, at least one through hole 70 is provided on the first support layer 2 and the passivation layer 4, and the through hole 70 penetrates the first support layer 2 and the passivation layer 4 at the same time, and the through hole 70 is located on the cantilever beam 7, and the through hole 70 is connected with the heat-insulating cavity 12. In actual operation, the heat can be conducted out through the cantilever beam 7 and the heat exchange structure 6, but the heat cannot be directly dissipated through the through hole 70. At the position where the through hole 70 is provided, the heat can only be conducted out along the side wall of the through hole 70 (i.e., the cantilever beam 7), and the heat transmission path is extended at this time. Based on this, the through hole 70 provided on the cantilever beam 7 increases the thermal resistance of the cantilever beam 7 while ensuring the strength of the cantilever beam 7, effectively reducing the heat conduction of the cantilever beam 7, and thus can expand the measurement range of the vacuum sensor, especially expand the measurement range of the vacuum sensor in the high vacuum direction, and also improve the measurement sensitivity of the vacuum sensor, and improve the accuracy of the measurement result. Furthermore, the protrusions and / or depressions formed on the first support layer 2 and the passivation layer 4 (i.e., the heat exchange structure 6) can effectively increase the specific surface area of ​​the heat exchange structure 6, thereby improving the heat exchange capacity of the heat exchange structure under high vacuum. In summary, the measurement range of the vacuum sensor can be expanded to achieve a range from atmospheric pressure to high vacuum (10 -2 Pa to 10- 4 The invention can measure the vacuum degree of 1000 Pa and improve the accuracy of the measurement result, thereby expanding the measurement lower limit of the vacuum degree sensor compared with the prior art.

[0100] See also Figures 11 to 16 , the second method for manufacturing a vacuum degree sensor includes:

[0101] First, see Fig.11 , providing a substrate 1; the substrate 1 has a first surface and a second surface opposite to each other;

[0102] Exemplarily, the base 1 includes a substrate 10 and a second support layer 11 disposed on the substrate 10. Specifically, a substrate 10 is provided, and then the second support layer 11 is deposited on the substrate 10. The material of the substrate may be a semiconductor material or a non-semiconductor material. For example, the substrate may be a glass substrate, a silicon substrate, a sapphire substrate or a polymer substrate. The material of the second support layer may be an inorganic material or an organic material. For example, the second support layer may be a silicon second support layer, a silicon oxide second support layer, a polycrystalline silicon second support layer, an amorphous silicon second support layer or a polyimide second support layer. The thickness of the second support layer is greater than or equal to 2 μm and less than or equal to 50 μm. For example, the thickness of the second support layer may be 2 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm or 50 μm.

[0103] Next, see Fig.12, etching the first surface of the substrate 1 so that the substrate 1 has a plurality of spaced grooves; and / or, depositing a protrusion structure material layer on the first surface of the substrate 1 to form a plurality of spaced protrusion structures on the first surface of the substrate 1.

[0104] For example, see Fig.12 After providing the substrate 1, the second support layer 11 can be selectively etched by wet chemical etching, plasma etching, laser etching or ultrasonic drilling to form a plurality of spaced grooves 9. Alternatively, a protruding structure material layer is deposited on a surface of the second support layer 11 away from the substrate 10 by a deposition process to form a plurality of spaced protruding structures on a surface of the second support layer 11 away from the substrate 10.

[0105] In the embodiments of the present invention, see Fig.12 The second supporting layer 11 is etched by an etching process so that the second supporting layer 11 has a plurality of grooves 9 distributed at intervals. The depth of the grooves is not specifically limited herein.

[0106] Next, see Fig.13 , forming a first supporting layer 2 on a first surface of the substrate 1;

[0107] Exemplarily, the first supporting layer 2 is conformally formed on a side of the second supporting layer 11 away from the substrate 10. When a groove 9 or a protruding structure is formed on the second supporting layer 11, the first supporting layer 2 conformally formed on the second supporting layer 11 also has a concave portion or a convex portion corresponding to the groove or protruding structure of the second supporting layer 11.

[0108] In the embodiments of the present invention, see Fig.12 and Fig.13 The first support layer 2 is conformally formed on the second support layer 11 having a plurality of spaced grooves 9. At this time, the first support layer 2 has a plurality of spaced recessed portions corresponding to the grooves 9 on the second support layer 11 (i.e., the recessed portions are spaced apart). Fig.13 The first recessed portion 20 in the embodiment of the present invention.

[0109] Next, see Fig.14 , forming a thermistor 3 on a surface of the first supporting layer 2 away from the substrate 1;

[0110] Exemplarily, a thermistor material layer can be formed as a whole layer on the side of the first support layer away from the substrate, and then the thermistor material layer can be patterned to form a thermistor. As for the specific processing process, please refer to the prior art and will not be described in detail here. The above-mentioned thermistor is formed in a non-depressed portion. Furthermore, the above-mentioned thermistor can be located above the insulating cavity formed later. For example, the thermistor is formed in a protruding place relative to the depressed portion. It should be noted that the "protruding place relative to the depressed portion" may be flush with the first support layer formed on the second support layer (that is, flush with the first support layer in the connection structure), or it may be protruding relative to the first support layer formed on the second support layer (that is, protruding with the first support layer in the connection structure). For other descriptions of the thermistor, please refer to the description of the first aspect, and no specific limitation is made here.

[0111] Next, see Fig.14 , forming a passivation layer 4 on the first supporting layer 2 and the thermistor 3;

[0112] Exemplarily, the passivation layer is conformally formed on the first supporting layer and the thermistor. When the first supporting layer has a concave portion or a convex portion corresponding to the groove or convex structure of the second supporting layer, the passivation layer conformally formed on the first supporting layer and the thermistor also has a concave portion or a convex portion corresponding to the first supporting layer.

[0113] In the embodiments of the present invention, see Fig.14 The passivation layer 4 is conformally formed on the thermistor 3 and the first support layer 2 having a plurality of recessed portions spaced apart. In this case, the passivation layer 4 has a shape similar to the recessed portions on the first support layer 2 (i.e., the recessed portions attached to the thermistor 3). Fig.13 The first recessed portion 20 in the middle corresponds to a plurality of recessed portions (i.e., the first recessed portion 20 in the middle) distributed at intervals. Fig.14 The second recessed portion 40 in the embodiment of the present invention.

[0114] Next, see Fig.15 , along the direction from the first supporting layer 2 to the passivation layer 4, at least one through hole 70 is opened on the first supporting layer 2 and the passivation layer 4; the through hole 70 penetrates the first supporting layer 2 and the passivation layer 4 at the same time; before or after this step or synchronously with this step, a pad required later is formed. As for the specific formation process of the pad, please refer to the prior art and will not be described in detail here.

[0115] Next, see Fig.16 , processing the substrate 1 along the height direction of the substrate 1 so that the substrate 1 has a heat-insulating cavity 12;

[0116] Specifically, along the direction from the second supporting layer 11 to the substrate 10, the second supporting layer 11 is etched so that the second supporting layer 11 has an insulating cavity 12, and the insulating cavity 12 runs through the second supporting layer 11. As for the specific method of etching the second supporting layer 11, reference can be made to the prior art, and no specific limitation is made here. It should be noted that the insulating cavity 12 does not run through the substrate 10.

[0117] Among them, see Figure 2 and Fig.16 The laminated structure formed by the first supporting layer 2 and the passivation layer 4 includes a connection structure 5 corresponding to the substrate 1, a heat exchange structure 6 provided with a thermistor 3, and a cantilever beam 7 for connecting the heat exchange structure 6 and the connection structure 5, and the cantilever beam 7 and the heat exchange structure 6 are both located above the heat insulating cavity 12. The through holes 70 are all located on the cantilever beam 7, and the through holes 70 are connected to the heat insulating cavity 12.

[0118] In summary, the vacuum sensor manufacturing method provided by the embodiment of the present invention has the advantages of simple process, high yield, good consistency and low cost for manufacturing the vacuum sensor.

[0119] In the description of the above embodiments, specific features, structures, materials or characteristics may be combined in a suitable manner in any one or more embodiments or examples.

[0120] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A vacuum sensor, characterized in that: include: a substrate having a thermally insulating cavity; The substrate has a first side and a second side that are opposite; A first supporting layer formed on a first surface of the substrate; a thermistor formed on a surface of the first supporting layer away from the substrate; a passivation layer, covering the first supporting layer and the thermistor; Among them, the stacked structure formed by the first supporting layer and the passivation layer includes a connecting structure corresponding to the substrate, a heat exchange structure provided with the thermistor, and a cantilever beam used to connect the heat exchange structure and the connecting structure; the cantilever beam and the heat exchange structure are both located above the insulating cavity; along the direction from the first supporting layer to the passivation layer, at least one through hole is opened on the cantilever beam, the through hole passes through the cantilever beam, and the through hole is connected to the insulating cavity.

2. The vacuum sensor according to claim 1, characterized in that: The cross-sectional shape of the through hole is an ellipse or a circle or a closed figure formed by an arc and a line segment.

3. The vacuum sensor according to claim 1, characterized in that: The first supporting layer has at least one protrusion and / or at least one recess; the passivation layer is conformally formed on the first supporting layer and the thermistor.

4. The vacuum sensor according to claim 3, characterized in that: Along the direction from the first supporting layer to the passivation layer, the cross-sectional shape of the protrusion is a closed figure composed of a triangle, a trapezoid, a rectangle, or an arc and a line segment; the cross-sectional shape of the recessed portion is a closed figure composed of a triangle, a trapezoid, a rectangle, or an arc and a line segment.

5. The vacuum sensor according to claim 1, characterized in that: The base is a substrate; along the height direction of the substrate, the thermal insulation cavity penetrates the substrate; Alternatively, the base includes a substrate and a second supporting layer disposed on the substrate; the thermal insulation cavity penetrates the second supporting layer along a direction from the second supporting layer to the substrate; and the first supporting layer is formed on the second supporting layer.

6. The vacuum sensor according to claim 1, characterized in that: The material of the first supporting layer includes one or more of silicon oxide, silicon nitride, and silicon oxynitride; The material of the passivation layer includes one or more of silicon oxide, silicon nitride, and silicon oxynitride; The material of the thermistor includes one or more of metal alloy, nickel, tungsten, platinum, titanium, and cobalt; or, the material of the thermistor includes polysilicon, vanadium oxide, or ceramic.

7. A method for manufacturing a vacuum sensor, characterized in that: include: providing a substrate; The substrate has a first side and a second side that are opposite; forming a first supporting layer on the first surface of the substrate; forming a thermistor on a surface of the first supporting layer away from the substrate; forming a passivation layer on the first supporting layer and the thermistor; At least one through hole is opened on the first supporting layer and the passivation layer along the direction from the first supporting layer to the passivation layer; the through hole penetrates the first supporting layer and the passivation layer at the same time; Processing the substrate along the height direction of the substrate so that the substrate has a thermal insulation cavity; Among them, the stacked structure formed by the first supporting layer and the passivation layer includes a connecting structure corresponding to the substrate, a heat exchange structure provided with the thermistor, and a cantilever beam for connecting the heat exchange structure and the connecting structure; the cantilever beam and the heat exchange structure are both located above the insulating cavity; and the through holes are both located on the cantilever beam.

8. The method for manufacturing a vacuum degree sensor according to claim 7, characterized in that: Before forming the first supporting layer on the first surface of the substrate, the method for manufacturing the vacuum sensor further includes: Etching the first surface of the substrate so that the substrate has a plurality of grooves distributed at intervals; And / or, a protrusion structure material layer is deposited on the first surface of the substrate to form a plurality of protrusion structures distributed at intervals on the first surface of the substrate.

9. The method for manufacturing a vacuum degree sensor according to claim 8, characterized in that: The first supporting layer is conformally formed on the first surface of the substrate; The passivation layer is conformally formed on the first support layer and the thermistor.

10. The method for manufacturing a vacuum degree sensor according to claim 7, characterized in that: When the base is a substrate, processing the base along the height direction of the base so that the base has a thermal insulation cavity comprises: etching the substrate along the height direction of the substrate so that the substrate has a thermal insulation cavity, wherein the thermal insulation cavity penetrates the substrate; When the base includes a substrate and a second supporting layer arranged on the substrate, the first supporting layer is formed on a surface of the second supporting layer away from the substrate; along the height direction of the substrate, processing the substrate so that the substrate has an insulating cavity includes: etching the second supporting layer along the direction from the second supporting layer to the substrate so that the second supporting layer has an insulating cavity, and the insulating cavity penetrates the second supporting layer.

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