JP2011252834A - Sensor and method for manufacturing the same - Google Patents

Sensor and method for manufacturing the same Download PDF

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JP2011252834A
JP2011252834A JP2010127899A JP2010127899A JP2011252834A JP 2011252834 A JP2011252834 A JP 2011252834A JP 2010127899 A JP2010127899 A JP 2010127899A JP 2010127899 A JP2010127899 A JP 2010127899A JP 2011252834 A JP2011252834 A JP 2011252834A
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film
sensor
surface
formed
base
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Koichi Igarashi
康一 五十嵐
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Yamatake Corp
株式会社山武
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Abstract

PROBLEM TO BE SOLVED: To provide a sensor capable of covering a surface of a concave portion on a base, and a method for manufacturing the sensor.SOLUTION: A flow sensor of an exemplary sensor according to the present invention is provided with a base 20 having a cavity 25 on one side and a sensor thin film 30 provided on the one side of the base 20. The sensor thin film 30 has a slit 36 opening to the cavity 25. The cross-sectional shape of the cavity 25 is, for example, a boat-like concave shape and a surface A of the cavity 25 is covered with a film X that is formed by an atomic layer deposition method.

Description

  Some embodiments according to the present invention relate to a base (substrate), a sensor provided on one surface of the base, and a manufacturing method thereof.

  In some sensors including a planar detection unit (sensing unit) supported by a base, the surface of the detection unit is coated using a method such as sputtering, CVD, or vapor deposition.

  In addition, there is known one in which the surface of a planar detection unit is covered with a silicon-based resin (for example, see Patent Document 1). Such a silicon-based resin has a better covering property than an inorganic film material formed by a sputtering method or a CVD method, and can cover and protect a three-dimensional structure detection portion having protrusions and steps.

Republished WO01 / 046708

  However, when the sensor is in direct contact with a corrosive sensor, the sensor cannot be applied to a sensor coated with a silicon-based resin because the formed film does not have corrosion resistance. In addition, when the sensor is formed of a film of an inorganic material, the planar detection unit (sensing unit) can be protected by a corrosion-resistant film, but overhangs with respect to a base having a recess such as a cavity. When there is an overhanging shielding object, it is impossible to form a film around the back side of the shielding object, so that there is a problem that it is difficult to protect the bottom surface of the cavity.

  Some aspects of the present invention have been made in view of the above-described problems, and an object thereof is to provide a sensor capable of covering the surface of a recess of a base with a film and a method for manufacturing the same. .

  A sensor according to the present invention includes a base having a recess on one surface and a sensor thin film provided on one surface and having an opening that leads to the recess, and the surface of the recess is formed by an atomic layer deposition method. It is covered with the formed film.

  According to such a configuration, a sensor thin film having an opening leading to the recess is provided on one surface of the base having the recess, and the surface of the recess is covered with a film formed by an atomic layer deposition method. ing. Here, the atomic layer deposition method repeats a cycle of surface adsorption, film formation by reaction, and removal (removal) of excess molecules by purging for each molecule of the raw material compound, so that protrusions (protrusions) and steps are formed. Alternatively, it is possible to form a film by entering into a minute space of a three-dimensional structure such as the back side of the shield. In addition, the atomic layer deposition method has the characteristic of maintaining the same growth rate over the entire range in which the reaction raw material is adsorbed, so that a uniform and thin film can be formed in a relatively large range (large area). is there.

  Preferably, the aforementioned film has corrosion resistance to the fluorine-containing material.

  According to this structure, the film | membrane which coat | covers the surface of a recessed part has corrosion resistance with respect to a fluorine-containing substance. Thereby, in the conventional sensor, the surface of the concave portion is exposed or not sufficiently covered, whereas in the sensor of the present invention, the surface of the concave portion is a film having corrosion resistance against the fluorine-containing substance. Therefore, the sensor of the present invention can be suitably used in an environment where a corrosive gas such as a fluorine-containing gas exists.

  Preferably, the sensor thin film has a circuit unit for detecting a predetermined physical quantity, and at least a part of the circuit unit is covered with the above-described film.

  According to such a configuration, at least a part of the circuit portion of the sensor thin film is also covered with the film formed by the atomic layer deposition method. Thereby, a circuit part, especially a detection part can be protected. In addition, since the atomic layer deposition method enables uniform and thin film formation, the sensitivity and responsiveness reduction and stress of the detection unit, which were conventionally caused by the non-uniform or thick film to be coated, are caused. It is possible to reduce the risk of breakage due to.

  Preferably, the side surface of the base is covered with the aforementioned film.

  According to such a configuration, the side surface of the base is also covered with the film formed by the atomic layer deposition method. Thereby, for example, when the side surface of the base is exposed (exposed) to corrosive gas such as fluorine-containing gas, it can be suitably used.

  Preferably, the aforementioned film is aluminum oxide.

According to such a configuration, the film formed by the atomic layer deposition method is aluminum oxide (alumina, Al 2 O 3 ). Thereby, the film | membrane which has corrosion resistance with respect to a fluorine-containing substance is easily realizable.

  Preferably, the aforementioned film is silicon nitride.

  According to this configuration, the film formed by the atomic layer deposition method is silicon nitride (SiN). Thereby, the film | membrane which has corrosion resistance with respect to a fluorine-containing substance is easily realizable. In addition, for example, when a circuit portion is covered with a silicon nitride insulating film and then formed on the insulating film, the insulating film is formed with a silicon nitride film when a defect (defect) occurs in the insulating film. Can be compensated (filled), and sensor defects can be reduced.

  A method for manufacturing a sensor according to the present invention is a method for manufacturing a sensor comprising a base and a sensor thin film provided on one surface of the base, wherein the sensor thin film is formed with an opening that communicates with one surface. A step of forming a recess on one surface, and a step of covering the surface of the recess with a film formed by an atomic layer deposition method.

  According to such a configuration, the sensor thin film provided on one surface of the base is formed with an opening that communicates with the one surface, the recess is formed on the one surface, and is formed by atomic layer deposition. The surface of the recess is covered with a film. Here, the atomic layer deposition method repeats a cycle of surface adsorption, film formation by reaction, and removal (removal) of excess molecules by purging for each molecule of the raw material compound, so that protrusions (protrusions) and steps are formed. Alternatively, it is possible to form a film by entering into a minute space of a three-dimensional structure such as the back side of the shield. In addition, the atomic layer deposition method has the characteristic of maintaining the same growth rate over the entire range in which the reaction raw material is adsorbed, so that a uniform and thin film can be formed in a relatively large range (large area). is there.

  Preferably, the aforementioned film has corrosion resistance to the fluorine-containing material.

  According to this structure, the film | membrane which coat | covers the surface of a recessed part has corrosion resistance with respect to a fluorine-containing substance. Thereby, in the conventional sensor, the surface of the concave portion is exposed or not sufficiently covered, whereas in the sensor manufactured according to this embodiment, the surface of the concave portion is against the fluorine-containing substance. Since it is covered with a film having corrosion resistance, the sensor of this embodiment can be suitably used in an environment where a corrosive gas such as a fluorine-containing gas exists.

  Preferably, the above-mentioned sensor thin film has a circuit part for detecting a predetermined physical quantity, and the step of covering the recess includes the step of covering at least a part of the circuit part with the above-mentioned film.

  According to such a configuration, at least a part of the circuit portion of the sensor thin film is also covered with the film formed by the atomic layer deposition method. Thereby, a part of circuit part, especially a detection part can be protected. In addition, since the atomic layer deposition method enables uniform and thin film formation, the sensitivity and responsiveness reduction and stress of the detection unit, which were conventionally caused by the non-uniform or thick film to be coated, are caused. It is possible to reduce the risk of breakage due to.

  Preferably, the step of covering the recess includes the step of covering the side surface of the base with the above-described film.

  According to this configuration, the side surface of the base is also covered with the film formed by the atomic layer deposition method. Thereby, for example, when the side surface of the sensor is exposed (exposed) to corrosive gas such as fluorine-containing gas, it can be suitably used.

  Preferably, the aforementioned film is aluminum oxide.

According to such a configuration, the film formed by the atomic layer deposition method is aluminum oxide (alumina, Al 2 O 3 ). Thereby, the film | membrane which has corrosion resistance with respect to a fluorine-containing substance is easily realizable.

  Preferably, the aforementioned film is silicon nitride.

  According to such a configuration, the film formed by the atomic layer deposition method is silicon nitride (SiN). Thereby, the film | membrane which has corrosion resistance with respect to a fluorine-containing substance is easily realizable. In addition, for example, when a circuit portion is covered with a silicon nitride insulating film and then formed on the insulating film, the insulating film is formed with a silicon nitride film when a defect (defect) occurs in the insulating film. Can be compensated (filled), and sensor defects can be reduced.

  According to the present invention, the film is formed by the atomic layer deposition method, so that the sensor thin film extends over the concave portion (shield) around the concave portion. A film can also be formed on the stern part, and the surface of the recess can be uniformly and thinly coated.

It is a perspective view explaining the flow sensor by the example of the sensor which concerns on this invention. It is a VI-VI arrow direction cross section shown in FIG. It is a perspective view explaining the other example of the flow sensor shown in FIG. It is a VII-VII line arrow direction sectional view shown in FIG. It is a principal part expanded side sectional view for demonstrating the film | membrane which coat | covers a circuit part. It is a principal part expanded side sectional view for demonstrating the film | membrane which coat | covers a circuit part. It is a sectional side view explaining the example of installation in the modification of the flow sensor shown in FIG. FIG. 8 is a side sectional view of the flow sensor shown in FIG. 7. It is side sectional drawing explaining an example of the manufacturing method of the sensor which concerns on this invention. It is side sectional drawing explaining an example of the manufacturing method of the sensor which concerns on this invention. It is side sectional drawing explaining an example of the manufacturing method of the sensor which concerns on this invention. It is side sectional drawing explaining an example of the manufacturing method of the sensor which concerns on this invention. It is side sectional drawing explaining an example of the manufacturing method of the sensor which concerns on this invention. It is side sectional drawing explaining an example of the manufacturing method of the sensor which concerns on this invention. It is side sectional drawing explaining an example of the manufacturing method of the sensor which concerns on this invention.

  Embodiments of the present invention will be described below. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, the drawings are schematic. Therefore, specific dimensions and the like should be determined in light of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings. In the following description, the upper side of the drawing is referred to as “upper”, the lower side as “lower”, the left side as “left”, and the right side as “right”.

<Sensor>
1 to 6 show an example of a sensor according to the present invention. FIG. 1 is a perspective view illustrating a flow sensor according to an example of a sensor according to the present invention, and FIG. 2 is a cross-sectional view in the direction of arrows VI-VI shown in FIG. As shown in FIGS. 1 and 2, the flow sensor 10 includes a base 20 having a cavity (recess) 25 on one surface (upper surface in FIGS. 1 and 2), and covers the cavity 25 on the base 20. And the sensor thin film 30 arranged as described above.

  In addition, the flow sensor 10 is provided at the center of the sensor thin film 30, and a heater (resistive element) 31 for heating fluid flowing at a constant speed, and on both sides of the heater 31 with the heater 31 sandwiched between the sensor thin film 30. A pair of resistive elements 32 and 33 provided, an ambient temperature sensor (resistive element) 34 provided on one side of the base 20, and electrodes provided in the vicinity of the corners having a diagonal relationship with the sensor thin film 30 35. The sensor thin film 30 has a plurality of slits (openings) 36 that communicate with the cavity 25 of the base 20.

The heater 31, the resistance elements 32 and 33, the ambient temperature sensor 34, and the electrode 35 of the present embodiment correspond to an example of a “circuit unit” for detecting a predetermined physical quantity in the sensor according to the present invention. The circuit part is preferably provided on the lower insulating film after a lower insulating film (not shown) is formed on the upper surface of the base 20. Thereby, the circuit unit can be electrically insulated from the base 20. Furthermore, it is preferable to form an upper insulating film (not shown) on the upper surface of the circuit portion. Thereby, the electrical insulation of a circuit part is improved. For example, silicon nitride (SiN) or silicon oxide (SiO 2 ) can be used as the material of the lower insulating film and the upper insulating film.

  The flow sensor 10 having such a configuration includes, for example, a resistance element 32, a heater 31, and a resistor along the flow direction of a fluid to be measured, for example, a gas, as indicated by a block arrow in FIGS. The elements 33 are arranged in order. In this case, the resistance element 32 functions as an upstream temperature measurement resistance element (upstream temperature sensor) provided upstream of the heater 31 (left side in FIGS. 1 and 2), and the resistance element 33 is the heater 31. It functions as a downstream side resistance temperature detector (downstream temperature sensor) provided on the downstream side (right side in FIGS. 1 and 2).

  The sensor thin film 30 covering the cavity 25 has a small heat capacity and forms a diaphragm having a heat insulating property with respect to the base 20. The ambient temperature sensor 34 measures the temperature of gas flowing through a pipe line (not shown) where the flow sensor 10 is installed. The heater 31 heats the gas so that it is higher than the temperature of the gas measured by the ambient temperature sensor 34 by a certain temperature (for example, 40 ° C.). The upstream resistance temperature element 32 is used to detect a temperature upstream of the heater 31, and the downstream temperature resistance element 33 is used to detect a temperature downstream of the heater 31.

  Here, when the gas in the pipe line is stationary, the heat applied by the heater 31 diffuses symmetrically in the upstream direction and the downstream direction. Accordingly, the temperatures of the upstream resistance temperature element 32 and the downstream resistance temperature element 33 are equal, and the electrical resistances of the upstream resistance temperature element 32 and the downstream resistance temperature element 33 are equal. On the other hand, when the gas in the pipeline flows from upstream to downstream, the heat applied by the heater 31 is carried in the downstream direction. Therefore, the temperature of the downstream temperature measuring resistance element 33 is higher than the temperature of the upstream temperature measuring resistance element 32.

  Such a temperature difference causes a difference between the electrical resistance of the upstream temperature measuring resistance element 32 and the electrical resistance of the downstream temperature measuring resistance element 33. The difference between the electrical resistance of the downstream resistance temperature element 33 and the electrical resistance of the upstream resistance temperature element 32 has a correlation with the gas velocity and flow rate in the pipe. Therefore, based on the difference between the electrical resistance of the downstream resistance temperature sensor 33 and the electrical resistance of the upstream resistance temperature sensor 32, the speed (flow velocity) and flow rate of the fluid flowing through the pipeline can be calculated. Information on the electrical resistance of the resistance elements 31, 32 and 33 can be extracted as an electrical signal through the electrode 35 shown in FIG.

  The thickness of the base 20 shown in FIGS. 1 and 2 is, for example, 525 μm, and the vertical and horizontal dimensions of the base 20 are each about 2 mm, for example. However, the dimension and shape of the substrate 20 are not limited to these. As a material for the base 20, for example, silicon (Si) or the like can be used.

  The cavity 25 can be formed using anisotropic etching, MEMS (Micro Electro Mechanical Systems) technology, or the like. FIG. 2 illustrates a state in which a cavity 25 having a boat-shaped concave shape is formed as an example.

The thickness of the sensor thin film 30 shown in FIGS. 1 and 2 is, for example, 1 μm, and the vertical and horizontal dimensions of the sensor thin film 30 are, for example, the same as the base 20 (about 2 mm). Examples of the material of the sensor thin film 30 include silicon nitride (SiN) and silicon oxide (SiO 2 ).

Platinum (Pt) or the like can be used as the material of each resistance element 31, 32, 33, 34. Further, a lithography method or the like can be applied to the formation of each of the resistance elements 31, 32, 33, and 34. Each resistance element 31, 32, 33, 34 is electrically insulated from the base 20 by the sensor thin film 30.

  The surface A of the cavity 25 shown in FIG. 2 is covered with a film X formed by an atomic layer deposition (ALD) method. Here, the atomic layer deposition method repeats a cycle of surface adsorption, film formation by reaction, and removal (removal) of excess molecules by purging for each molecule of the raw material compound, so that protrusions (protrusions) and steps are formed. Alternatively, it is possible to form a film by entering into a minute space of a three-dimensional structure such as the back side of the shield. In addition, the atomic layer deposition method has the characteristic of maintaining the same growth rate over the entire range in which the reaction raw material is adsorbed, so that a uniform and thin film can be formed in a relatively large range (large area). is there.

The film X formed by the atomic layer deposition method preferably has corrosion resistance against a corrosive gas such as a fluorine-containing substance such as trifluoromethane (CHF 3 ) gas or sulfur hexafluoride (SF 6 ) gas. . Thereby, in the conventional sensor, the surface of the cavity (concave portion) is exposed or not sufficiently covered, whereas in the flow sensor 10 of the present embodiment, the surface A of the cavity 25 contains fluorine. Since it is covered with the film X having corrosion resistance to the substance, for example, the flow sensor 10 of this embodiment can be suitably used in an environment where corrosive gas such as fluorine-containing gas exists.

  Similarly to the surface A of the cavity 25, the resistive elements 31, 32, 33, and 34 shown in FIGS. 1 and 2, that is, a part of the circuit portion excluding the electrode 35 are also formed by the atomic layer deposition method. It is completely covered with. Thereby, a part of circuit part, especially the resistive elements 31, 32, and 33 can be coat | covered completely. In addition, the atomic layer deposition method enables uniform and thin film formation, so the sensitivity and responsiveness degradation and damage caused by stress, which were conventionally caused by the non-uniform or thick film to be coated, have occurred. The risk of this can be reduced. The electrode 35 is exposed without being covered so as to be electrically connected to an external circuit or the like. Therefore, when the film is formed using the atomic layer deposition method, the electrode 35 is protected in advance with a mask or the like.

  FIG. 3 is a perspective view for explaining another example of the flow sensor shown in FIG. 1, and FIG. 4 is a cross-sectional view taken along the line VII-VII shown in FIG. In FIGS. 1 and 2, a part of the circuit portion is covered, but the present invention is not limited to this. As shown in FIGS. 3 and 4, the electrode 21 may be provided on the lower surface (back surface) of the base 20 instead of the electrode 35. The electrode 21 is electrically connected to the circuit portion of the sensor thin film 30 via the electrode 22 penetrating the base 20, and can be electrically connected to an external circuit or the like from the electrode 21. In this case, each of the resistance elements 31, 32, 33, 34, that is, the entire circuit portion is covered with the film X formed by the atomic layer deposition method.

As a material (raw material) of the film X, for example, aluminum oxide (alumina, Al 2 O 3 ) is preferably used. Thereby, the film | membrane X which has corrosion resistance with respect to a fluorine-containing substance is easily realizable.

  FIG. 5 and FIG. 6 are enlarged cross-sectional side views of the main part for explaining the film covering the circuit part. When the sensor thin film 30 is formed as the lower insulating film 37 and the upper insulating film 38, the film X is uniformly formed below the lower insulating film 37 and on the upper insulating film 38. In this case, as a material (raw material) of the film X, for example, silicon nitride (SiN) is more preferable. Thereby, the film | membrane X which has corrosion resistance with respect to a fluorine-containing substance is easily realizable. As shown in FIG. 5, for example, when a defect (defect) B occurs in the upper insulating film 38 of silicon nitride formed on the resistance element 31, as shown in FIG. Thus, the defect B of the upper insulating film 38 can be compensated (filled), and product defects of the flow sensor 10 can be reduced.

  In this embodiment, although the flow sensor 10 was shown as an example of the sensor according to the present invention, it is not limited to this, and other types of sensors such as a temperature sensor and a pressure sensor may be used.

  As described above, according to the flow sensor 10 of the present embodiment, the sensor thin film 30 having the slit 36 communicating with the cavity 25 is provided on one surface of the base 20 having the cavity 25, and the surface A of the cavity 25 is The film X is formed by an atomic layer deposition method. Here, the atomic layer deposition method repeats a cycle of surface adsorption, film formation by reaction, and removal (removal) of excess molecules by purging for each molecule of the raw material compound, so that protrusions (protrusions) and steps are formed. Alternatively, it is possible to form a film by entering into a minute space of a three-dimensional structure such as the back side of the shield. In addition, the atomic layer deposition method has the characteristic of maintaining the same growth rate over the entire range in which the reaction raw material is adsorbed, so that a uniform and thin film can be formed in a relatively large range (large area). is there. Therefore, by forming the film X by the atomic layer deposition method, the sensor thin film 30 wraps around the cavity 25 over the portion (shield) where the sensor thin film 30 protrudes in an overhang shape. For example, the cross-sectional shape shown in FIG. A film can also be formed on the bow and stern portions of the cavity 25, and the surface A of the cavity 25 can be uniformly and thinly coated with the film X.

  Further, according to the flow sensor 10 in the present embodiment, the film X covering the surface A of the cavity 25 has corrosion resistance against the fluorine-containing substance. Thus, in the conventional sensor, the surface of the cavity is exposed or not sufficiently covered, whereas in the flow sensor 10 of the present embodiment, the surface A of the cavity 25 is against the fluorine-containing substance. In other words, the flow sensor 10 according to the present embodiment can be suitably used in an environment where corrosive gas such as fluorine-containing gas exists.

  Further, according to the flow sensor 10 in the present embodiment, at least a part of the circuit portion of the sensor thin film 30 is covered with the film X formed by the atomic layer deposition method. Thereby, a part of circuit part, especially the resistive elements 31, 32, 33, etc. can be completely covered. In addition, the atomic layer deposition method enables uniform and thin film formation, so the sensitivity and responsiveness degradation and damage caused by stress, which were conventionally caused by the non-uniform or thick film to be coated, have occurred. The risk of this can be reduced.

Moreover, according to the flow sensor 10 in the present embodiment, the film X formed by the atomic layer deposition method is aluminum oxide (alumina, Al 2 O 3 ). Thereby, the film | membrane X which has corrosion resistance with respect to a fluorine-containing substance is easily realizable.

  Moreover, according to the flow sensor 10 in the present embodiment, the film X formed by the atomic layer deposition method is silicon nitride (SiN). Thereby, the film | membrane X which has corrosion resistance with respect to a fluorine-containing substance is easily realizable. Further, as shown in FIG. 5, for example, when a defect (defect) B is generated in the upper insulating film 38 of silicon nitride formed on the resistance element 31, as shown in FIG. The defect B of the upper insulating film 38 can be compensated (filled), and product defects of the flow sensor 10 can be reduced.

(Modification)
7 and 8 are diagrams for illustrating a modification of the flow sensor according to the example of the sensor according to the present invention. Unless otherwise specified, the same components as those in the above-described embodiment are denoted by the same reference numerals, and the description thereof is omitted. Further, components not shown in the figure are the same as those in the above-described embodiment.

  FIG. 7 is a side sectional view for explaining an installation example in a modification of the flow sensor shown in FIG. 1, and FIG. 8 is a side sectional view of the flow sensor shown in FIG. The flow sensor is usually installed on the inner wall of a conduit through which fluid flows. For example, as shown in FIG. 7, the flow sensor 10 </ b> A is provided on the inner wall of the upper portion of the pipe line 7, and the electrode 35 and the electrode 92 shown in FIG. 1 are electrically connected via an electrical wiring such as a bonding wire 93. It is connected. The electrode 92 is electrically connected to, for example, a circuit on the main body side of a flow meter including the flow sensor 10A, and can transmit an electrical signal obtained by the flow sensor 10A. Moreover, the electrode 92 penetrates the opening part (illustration omitted) formed in the pipe line 7, and the opening part is airtightly sealed with sealing members 8, such as a hermetic seal, for example. Thereby, the airtightness of the pipe line 7 is ensured, and the fluid flowing through the pipe line 7 is prevented from leaking.

  As shown in FIG. 8, in the flow sensor 10A, the side surface C of the base 20 is formed by the atomic layer deposition method as well as the surface A of the cavity 25 and a part of the circuit portion shown in FIGS. Covered with membrane X. As a result, as shown in FIG. 7, it can be suitably used when the side surface of the flow sensor 10A is exposed (exposed) to a corrosive fluid such as a fluorine-containing gas.

  Thus, according to the flow sensor 10A in the modification, the side surface C of the base 20 is also covered with the film X formed by the atomic layer deposition method. Thereby, in addition to the same effect as the flow sensor 10 described above, as shown in FIG. 7, for example, when the side surface of the flow sensor 10A is exposed (exposed) to a corrosive fluid such as a fluorine-containing gas. Can be used.

<Sensor manufacturing method>
9 to 15 are for illustrating an example of a method for manufacturing a sensor according to the present invention. 9 to 15 are side sectional views for explaining an example of a method for manufacturing a sensor according to the present invention. First, as shown in FIG. 9, an insulating film 71 such as silicon nitride or silicon oxide is formed over the entire surface on one surface and the other surface (upper surface and lower surface in FIG. 9) of a base 60 such as silicon. Note that a substrate such as glass may be bonded instead of the insulating film 71 formed on the lower surface of the base 60.

  Next, as shown in FIG. 10, a metal or oxide is deposited on the insulating film 71 formed on the upper surface of the base 60 by a method such as a sputtering method, a CVD method, a vacuum evaporation method, etc. The elements 72, 73, 74, and 75 that constitute the circuit portion for detecting the above are formed (patterned).

  Next, as shown in FIG. 11, an insulating film 76 such as silicon nitride or silicon oxide is further formed on each element 72, 73, 74, 75.

  Next, as shown in FIG. 12, a plurality of slits (opening portions) that are etched at predetermined positions in the insulating films 71 and 76 formed on the upper surface of the base 60 using a mask or the like and communicate with the upper surface of the base 60. ) 77, and an opening 75 a is formed by etching the element 75 that serves as an electrode in the insulating film 76 using a mask or the like.

  Next, as shown in FIG. 13, a metal or oxide is attached to the position of the opening 75a in FIG. 12 by a method such as sputtering, CVD, or vacuum deposition, and is electrically connected to an external circuit or the like. An electrode 75b is formed. Thereby, the sensor thin film 70 is provided on the upper surface of the base 60.

  Next, as shown in FIG. 14, anisotropic etching is performed on the upper surface of the base 60 through a plurality of slits 77 to form a cavity (concave portion) 65 having a boat-shaped concave shape, for example.

  Next, as shown in FIG. 15, the surface D of the cavity 65 is covered with a film X formed by an atomic layer deposition method. Thereby, the sensor 50 is manufactured. Here, the atomic layer deposition method repeats a cycle of surface adsorption, film formation by reaction, and removal (removal) of excess molecules by purging for each molecule of the raw material compound, so that protrusions (protrusions) and steps are formed. Alternatively, it is possible to form a film by entering into a minute space of a three-dimensional structure such as the back side of the shield. In addition, the atomic layer deposition method has the characteristic of maintaining the same growth rate over the entire range in which the reaction raw material is adsorbed, so that a uniform and thin film can be formed in a relatively large range (large area). is there.

The film X formed by the atomic layer deposition method preferably has corrosion resistance against a corrosive gas such as a fluorine-containing substance such as trifluoromethane (CHF 3 ) gas or sulfur hexafluoride (SF 6 ) gas. . Thereby, in the conventional sensor, the surface of the cavity is exposed or not sufficiently covered, whereas in the sensor 50 manufactured according to the present embodiment, the surface D of the cavity 65 is a fluorine-containing substance. Therefore, the sensor 50 according to the present embodiment can be suitably used in an environment where corrosive gas such as fluorine-containing gas exists.

  Similarly to the surface D of the cavity 65, each element 72, 73, 74 shown in FIG. 15, that is, a part of the circuit portion excluding the electrode 75b is covered with the film X formed by the atomic layer deposition method. Thereby, a part of circuit part, especially a detection part can be protected. In addition, since the atomic layer deposition method can form a uniform and thin film, the sensitivity and responsiveness of the detection unit, which has conventionally been caused by non-uniform or thick films to be coated, and The risk of damage due to stress can be reduced.

  As in the case shown in FIGS. 3 and 4, when the electrode is provided on the lower surface (back surface) of the base 60, the entire circuit portion may be covered with the film X formed by the atomic layer deposition method. Good.

  Further, the side surface E of the base 60 shown in FIG. 15 is also covered with the film X formed by the atomic layer deposition method. Thereby, similarly to the case shown in FIG. 7, it can be suitably used when the side surface of the sensor 50 is exposed (exposed) to a corrosive gas such as a fluorine-containing gas.

As a material (raw material) of the film X, for example, aluminum oxide (alumina, Al 2 O 3 ) is preferably used. Thereby, the film | membrane X which has corrosion resistance with respect to a fluorine-containing substance is easily realizable.

  Moreover, when forming the insulating films 71 and 76, as a material (raw material) of the film X, for example, silicon nitride (SiN) is more preferable. Thereby, the film which has corrosion resistance with respect to a fluorine-containing substance is easily realizable. Similarly to the case shown in FIG. 5, for example, when a defect (defect) occurs in the silicon nitride insulating film 76 formed on the elements 72, 73, and 74 constituting the circuit portion, FIG. As in the case shown, the defect of the insulating film 76 can be compensated (filled) with the silicon nitride film X, and the defective product of the sensor 50 can be reduced.

  In the present embodiment, as an example of a method for manufacturing a sensor according to the present invention, a method for manufacturing 50 units of sensors is shown, but the present invention is not limited to this. For example, the base 60 is used by being divided (divided) into a plurality of pieces from one wafer (not shown), but a plurality of sensors in the state of the wafer before being divided into the plurality of bases 60. After manufacturing 50, the wafer may be divided into a predetermined size. In this case, since a plurality of sensors 50 can be simultaneously coated with the film X formed by the atomic layer deposition method, the throughput of the process of coating with the film X can be improved.

  Alternatively, as in the flow sensor 10A illustrated in FIG. 9, for example, the seal member 8, the electrode 92, the bonding wire 93, and the like are attached and the sensor 50 is integrated (packaged), and then the integrated sensor 50 is replaced with an atomic layer. You may make it coat | cover with the film | membrane X formed by the deposition method. In this case, since the exposed portion of the integrated sensor 50 can be covered with the film X, for example, the corrosion resistance of the sensor 50 can be further improved.

  Thus, according to the manufacturing method of the sensor 50 in the present embodiment, the sensor thin film 70 provided on the upper surface of the base 60 is formed with the slit (opening) 77 leading to the upper surface, and the upper surface is formed on the upper surface. A cavity (concave portion) 65 is formed, and the surface D of the cavity 65 is covered with a film X formed by an atomic layer deposition method. Here, the atomic layer deposition method repeats a cycle of surface adsorption, film formation by reaction, and removal (removal) of excess molecules by purging for each molecule of the raw material compound, so that protrusions (protrusions) and steps are formed. Alternatively, it is possible to form a film by entering into a minute space of a three-dimensional structure such as the back side of the shield. In addition, the atomic layer deposition method has the characteristic of maintaining the same growth rate over the entire range in which the reaction raw material is adsorbed, so that a uniform and thin film can be formed in a relatively large range (large area). is there. Therefore, by forming the film X by the atomic layer deposition method, the sensor thin film 70 wraps around the cavity 65 over the portion (shield) where the sensor thin film 70 protrudes in an overhang shape. For example, the cross-sectional shape shown in FIG. A film can also be formed on the bow and stern portions of the cavity 65, and the surface D of the cavity 65 can be uniformly and thinly coated with a coating.

  In addition, according to the method for manufacturing the sensor 50 in the present embodiment, the film X that covers the surface D of the cavity 65 has corrosion resistance against the fluorine-containing substance. Thereby, in the conventional sensor, the surface of the cavity is exposed or not sufficiently covered, whereas in the sensor 50 manufactured according to the present embodiment, the surface D of the cavity 65 is a fluorine-containing substance. Therefore, the sensor 50 according to the present embodiment can be suitably used in an environment where corrosive gas such as fluorine-containing gas exists.

  Moreover, according to the manufacturing method of the sensor 50 in this embodiment, at least a part of the circuit portion of the sensor thin film 70 is covered with the film X formed by the atomic layer deposition method. Thereby, a part of circuit part, especially a detection part can be protected. In addition, the atomic layer deposition method enables uniform and thin film formation, so the sensitivity and responsiveness degradation and damage caused by stress, which were conventionally caused by the non-uniform or thick film to be coated, have occurred. The risk of this can be reduced.

  Further, according to the method for manufacturing the sensor 50 in the present embodiment, the side surface E of the base 60 is also covered with the film X formed by the atomic layer deposition method. Thereby, similarly to the case shown in FIG. 7, it can be suitably used when the side surface of the sensor 50 is exposed (exposed) to a corrosive gas such as a fluorine-containing gas.

Further, according to the method for manufacturing the sensor 50 in the present embodiment, the film X formed by the atomic layer deposition method is aluminum oxide (alumina, Al 2 O 3 ). Thereby, the film | membrane X which has corrosion resistance with respect to a fluorine-containing substance is easily realizable.

  Further, according to the method for manufacturing the sensor 50 in the present embodiment, the film X formed by the atomic layer deposition method is silicon nitride (SiN). Thereby, the film | membrane X which has corrosion resistance with respect to a fluorine-containing substance is easily realizable. Similarly to the case shown in FIG. 5, for example, when a defect (defect) occurs in the silicon nitride insulating film 76 formed on the elements 72, 73, and 74 constituting the circuit portion, FIG. Similarly to the case shown, the defect (defect) portion of the insulating film 76 can be compensated (filled) with the silicon nitride film X, and the product defects of the sensor 50 can be reduced.

  Note that the configurations of the above-described embodiments may be combined or a part of the components may be replaced. The configuration of the present invention is not limited to the above-described embodiment, and various modifications may be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 10 ... Flow sensor 20, 60 ... Base 25, 65 ... Cavity 30, 70 ... Sensor thin film 31, 32, 33, 34 ... Resistance element 35 ... Electrode 36 ... Slit 50 ... Sensor 72, 73, 74, 75 ... Element 77 ... Slit X ... Membrane

Claims (12)

  1. A base having a recess on one side;
    A sensor thin film provided on the one surface and having an opening leading to the recess,
    The sensor is characterized in that the surface of the recess is covered with a film formed by an atomic layer deposition method.
  2. The sensor according to claim 1, wherein the film has corrosion resistance against a fluorine-containing substance.
  3. The sensor thin film has a circuit unit for detecting a predetermined physical quantity,
    The sensor according to claim 1, wherein at least a part of the circuit unit is covered with the film.
  4. The sensor according to any one of claims 1 to 3, wherein a side surface of the base is covered with the film.
  5. The sensor according to any one of claims 1 to 4, wherein the film is aluminum oxide.
  6. The sensor according to any one of claims 1 to 4, wherein the film is silicon nitride.
  7. A method of manufacturing a sensor comprising a base and a sensor thin film provided on one surface of the base,
    Forming an opening leading to the one surface in the semiconductor substrate;
    Forming a recess on the one surface;
    And a step of covering the surface of the recess with a film formed by an atomic layer deposition method.
  8. The method of manufacturing a sensor according to claim 7, wherein the film has corrosion resistance against a fluorine-containing substance.
  9. The sensor thin film has a circuit unit for detecting a predetermined physical quantity,
    The method for manufacturing a sensor according to claim 7, wherein the step of covering the concave portion includes a step of covering at least a part of the circuit portion with the film.
  10. The method for manufacturing a sensor according to claim 7, wherein the step of covering the recess includes a step of covering a side surface of the base with a film.
  11. The method of manufacturing a sensor according to any one of claims 7 to 10, wherein the film is aluminum oxide.
  12. The method for manufacturing a sensor according to any one of claims 7 to 10, wherein the film is silicon nitride.
JP2010127899A 2010-06-03 2010-06-03 Sensor and method for manufacturing the same Pending JP2011252834A (en)

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Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102730621A (en) * 2012-06-15 2012-10-17 西安交通大学 Silicon-based micro-heating plate provided with embedded heating wire, and processing method thereof
JP2015194427A (en) * 2014-03-31 2015-11-05 アズビル株式会社 Flow sensor and manufacturing method for flow sensor
DE102014108351A1 (en) * 2014-06-13 2015-12-17 Endress+Hauser Flowtec Ag Measuring arrangement with a carrier element and a micromechanical sensor
US9804009B2 (en) 2012-06-15 2017-10-31 Hitachi Automotive Systems, Ltd. Thermal flow meter with diaphragm forming a reduced pressure sealed space
CN107827078A (en) * 2017-09-20 2018-03-23 上海申矽凌微电子科技有限公司 The manufacture method of sensor and the thus sensor of method manufacture
WO2018123757A1 (en) * 2016-12-26 2018-07-05 株式会社村田製作所 Electronic device and manufacturing method therefor

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102730621A (en) * 2012-06-15 2012-10-17 西安交通大学 Silicon-based micro-heating plate provided with embedded heating wire, and processing method thereof
CN102730621B (en) * 2012-06-15 2015-05-27 西安交通大学 Silicon-based micro-heating plate provided with embedded heating wire, and processing method thereof
US9804009B2 (en) 2012-06-15 2017-10-31 Hitachi Automotive Systems, Ltd. Thermal flow meter with diaphragm forming a reduced pressure sealed space
JP2015194427A (en) * 2014-03-31 2015-11-05 アズビル株式会社 Flow sensor and manufacturing method for flow sensor
DE102014108351A1 (en) * 2014-06-13 2015-12-17 Endress+Hauser Flowtec Ag Measuring arrangement with a carrier element and a micromechanical sensor
WO2018123757A1 (en) * 2016-12-26 2018-07-05 株式会社村田製作所 Electronic device and manufacturing method therefor
CN107827078A (en) * 2017-09-20 2018-03-23 上海申矽凌微电子科技有限公司 The manufacture method of sensor and the thus sensor of method manufacture

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