JP2008292310A - Sensor device and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sensor device of which the manufacturing yield can be improved, and to provide a method for manufacturing the sensor device by using at least a sensor substrate so constituted that a thermal infrared radiation detection section is formed on a semiconductor substrate at a main surface side and a package substrate placed on the sensor substrate at the main surface side. <P>SOLUTION: In the sensor substrate 1, a portion formed at a bonding region E3 in multi-layer insulation film configured of an insulation film 11 formed on a first semiconductor substrate 10 at a main surface side and an insulation film (porous film constituted of porous silica) as a base of a heat insulation section 14, is etched back, and a first metallic layer 18 for sealing and a second metallic layer 19 for electric connection are then formed on the insulation film 11. The sensor substrate 1 and the package substrate 2 are bonded in room temperature such that the metallic layers 18, 28 for sealing are bonded with each other in the room temperature, and the metallic layers 19, 29 for electric connection are bonded with each other in the room temperature. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a sensor device including an infrared sensor and a manufacturing method thereof.

  Conventionally, as shown in FIG. 14, a sensor substrate 1 ′ in which a circuit element 130 ′ including a thermal infrared detector 13 ′ and a switching transistor is formed on the main surface side of a semiconductor substrate 10 ′ such as a silicon substrate, A sensor device comprising a package substrate 2 ′ sealed on the main surface side of the sensor substrate 1 ′ and joining the sensor substrate 1 ′ and the package substrate 2 ′ using a room temperature bonding method has been proposed. (For example, Patent Document 1).

Here, the sensor device having the configuration shown in FIG. 14 includes an interlayer insulating film (first insulating film) 116 ′ made of a silicon oxide film formed on the main surface side of the semiconductor substrate 10 ′ in the sensor substrate 1 ′, and the relevant A sealing metal layer 118 ′ is provided on a multilayer insulating film formed of a laminated film with a passivation film (second insulating film) 117 ′ formed on the interlayer insulating film 116 ′, and one of the package substrates 2 ′ is provided. A sealing metal layer 128 ′ is provided on the front surface side, and the sealing metal layers 118 ′ and 128 ′ of the sensor substrate 1 ′ and the package substrate 2 ′ are directly bonded to each other by a room temperature bonding method.
Japanese Patent No. 3519720

  However, as in the sensor device having the configuration shown in FIG. 14, a plurality of insulating films (in the example of FIG. 14, the interlayer insulating film 116 ′ and the insulating film formed on the main surface side of the semiconductor substrate 10 ′ in the sensor substrate 1 ′. Bonding in which a sealing metal layer 118 ′ provided on a multilayer insulating film made of a laminated film of a passivation film 117 ′) and a sealing metal layer 128 ′ provided on a package substrate 2 ′ are directly bonded by a room temperature bonding method. In the sensor device manufactured using the process, there is a problem that the yield of the bonding process is low at the time of manufacturing. In this type of sensor device, a through-hole wiring is formed on the package substrate and an electrical connection metal layer is provided, while an electrical connection metal layer is provided on the multilayer insulating film of the sensor substrate, and sealing is performed. A sensor device in which metal layers and metal layers for electrical connection are directly bonded by a room temperature bonding method is also conceivable. However, even in such a sensor device, there is a problem that the yield of the bonding process is low.

  The present invention has been made in view of the above-mentioned reasons, and its object is to provide at least a sensor substrate having a thermal infrared detector formed on the main surface side of a semiconductor substrate and the main surface side of the sensor substrate. Another object of the present invention is to provide a sensor device capable of improving the manufacturing yield of the sensor device manufactured using the package substrate and the manufacturing method thereof.

  The invention according to claim 1 includes at least a sensor substrate having a thermal infrared detecting portion formed on a main surface side of a semiconductor substrate, and a package substrate sealed on the main surface side of the sensor substrate. Sensor device in which activated sealing metal layers of a semiconductor substrate and a package substrate are bonded at room temperature, and the sensor substrate comprises a laminated film of a plurality of insulating films formed on the main surface side of the semiconductor substrate A step is formed between the region where the thermal infrared detector is formed in the multilayer insulating film and the bonding region where the sealing metal layer is formed, and a part of the multilayer insulating film is etched back. A sealing metal layer is formed on the surface of the bonding region flattened by the above.

  According to the present invention, the sensor substrate is formed on the surface of the bonding region portion flattened by etching back a part of the multilayer insulating film composed of a laminated film of a plurality of insulating films on the main surface side of the semiconductor substrate. Since the sealing metal layer is formed, it becomes possible to improve the flatness of the surface of the sealing metal layer, and the yield of the bonding process for bonding the sealing metal layers of the sensor substrate and the package substrate to each other at room temperature. It is possible to improve the manufacturing yield by increasing the manufacturing yield.

  According to a second aspect of the present invention, in the first aspect of the present invention, the sensor substrate is a first electrical connection metal layer electrically connected to the thermal infrared detection unit on the surface of the bonding region. The package substrate is formed with a second electrical connection metal layer joined to the first electrical connection metal layer and electrically connected to the second electrical connection metal layer. The sensor substrate and the package substrate are formed by bonding the activated electrical connection metal layers to each other at room temperature.

  According to the present invention, the sensor substrate includes the sealing metal layer and the first electrical connection on the surface of the joining region portion flattened by etching back a part of the multilayer insulating film. Since the metal layer for forming is formed, it is possible to form the metal layer for sealing and the first metal layer for electrical connection with the same thickness on the same level surface, and the metal layer for sealing It is possible to improve the flatness of the surfaces of the sensor substrate and the first electrical connection metal layer, and the sealing metal layers and the electrical connection metal layers of the sensor substrate and the package substrate are joined at room temperature. It is possible to increase the yield of the bonding process and improve the manufacturing yield.

  According to a third aspect of the present invention, in the second aspect of the present invention, the sensor substrate includes an IC portion that cooperates with the thermal infrared detection portion on the main surface side of the semiconductor substrate. The infrared detecting unit is electrically connected to the first metal layer for electrical connection through the IC unit.

  According to the present invention, the wiring length between the thermal infrared detection unit and the IC unit can be shortened.

  According to a fourth aspect of the present invention, there is provided a sensor device using at least a sensor substrate having a thermal infrared detecting portion formed on a main surface side of a semiconductor substrate and a package substrate sealed on the main surface side of the sensor substrate. A method for etching a portion of a sensor substrate that is formed in a bonding region with a package substrate, out of a multilayer insulating film formed of a plurality of insulating films formed on a main surface side of a semiconductor substrate. A flattening step of flattening the surface of the bonding region portion by backing, a metal layer forming step of forming a sealing metal layer on the surface of the bonding region portion after the flattening step, and a sensor substrate, A bonding step of bonding the activated sealing metal layers to the package substrate at room temperature.

  According to the present invention, a portion of the multi-layered insulating film formed of a laminated film of a plurality of insulating films on the main surface side of a semiconductor substrate is etched back by etching back a portion formed in a bonding region with the package substrate. Since the sealing metal layer is formed on the surface of the bonding region after the surface of the region is flattened, the flatness of the surface of the sealing metal layer can be improved. Since the yield of the joining process for room temperature joining of the metal layers for sealing with the package substrate can be increased, the production yield can be improved.

  According to a fifth aspect of the present invention, in the invention of the fourth aspect, a wafer level including a plurality of the sensor devices by performing all the steps until the bonding step is completed at the wafer level for each of the sensor substrate and the package substrate. A package structure is formed, and a dividing step of dividing the wafer level package structure into the sensor device is provided.

  According to this invention, mass productivity can be improved.

  According to the first aspect of the present invention, there is an effect that it is possible to improve the manufacturing yield by increasing the yield of the joining process of joining the sealing metal layers of the sensor substrate and the package substrate at room temperature.

  According to a fourth aspect of the present invention, a sensor device is manufactured by using a sensor substrate having a thermal infrared detector formed on the main surface side of a semiconductor substrate and a package substrate disposed on the main surface side of the sensor substrate. There is an effect that the yield can be improved.

(Embodiment 1)
Hereinafter, after describing the sensor device of the present embodiment with reference to FIGS. 1 and 2, a characteristic manufacturing method will be described with reference to FIGS. 3 and 4. Note that FIG. 1 corresponds to a schematic cross-sectional view of FIG. 2 taken along a line AA ′ and viewed from the direction of the arrows.

  The sensor device according to the present embodiment is an infrared sensor, and includes a sensor substrate 1 in which a thermal infrared detector 13 thermally insulated from the surroundings is formed on the main surface side of the first semiconductor substrate 10, and a second semiconductor substrate 20. For the package which is formed on the main surface side of the sensor substrate 1 and encloses the thermal infrared detector 13 and is sealed to the main surface side of the sensor substrate 1 so as to form a cavity 30 with the sensor substrate 1. And a substrate 2. Here, the outer peripheral shapes of the sensor substrate 1 and the package substrate 2 are rectangular, and the package substrate 2 is formed to have the same outer dimensions as the sensor substrate 1. In the present embodiment, a silicon substrate is used for each of the semiconductor substrates 10 and 20.

  The sensor substrate 1 includes a base substrate portion 12 composed of a first semiconductor substrate 10 and an insulating film 11 made of a silicon nitride film formed on the main surface of the first semiconductor substrate 10, and the above-described thermal type. An infrared detection unit 13 and a heat insulation unit 14 that thermally insulates the thermal infrared detection unit 13 and the base substrate unit 12 are provided. In addition, the heat insulation part 14 in this embodiment is supporting the thermal type infrared detection part 13 so that the thermal type infrared detection part 13 may be spaced apart from one surface of the base substrate part 12.

  The heat insulating part 14 includes a holding part 14 a that holds the thermal infrared detection part 13, and two leg parts 14 b and 14 b that connect the holding part 14 a and the base substrate part 12. In addition, the heat insulation part 14 is mentioned later.

  The thermal infrared detector 13 is a bolometer-type sensing element whose electric resistance value changes according to temperature, and includes a sensor layer including a Ti film on the holding unit 14a side and a TiN film on the Ti film. Yes. Here, the TiN film is provided as an antioxidant film for the Ti film. The material of the sensor layer is not limited to Ti, and for example, amorphous Si, VOx, or the like may be employed. The thermal infrared detector 13 is not limited to a sensing element whose electrical resistance value changes according to temperature, but a sensing element whose dielectric constant changes according to temperature, a thermopile type sensing element, and a pyroelectric type sensing element. Even if any sensing element is employed, it can be formed using a general thin film forming technique by appropriately selecting the material. Here, for example, PZT, BST, or the like may be employed as the material of the sensing element whose dielectric constant changes depending on the temperature.

  The thermal infrared detector 13 is formed in a meandering shape (here, a folded shape), and a wiring layer whose both ends are extended along the leg portions 14 b and 14 b of the heat insulating portion 14. 15 and 15 and the first electrical connection on the insulating film 11 in the bonding region E3 in the peripheral portion of the base substrate portion 12 through the lead wirings 16 and 16 electrically connected to the wiring layers 15 and 15 The metal layers 19 and 19 are electrically connected. Here, in the sensor substrate 1 in the present embodiment, one end portion of the lead-out wiring 16 is formed on the wiring layer 15 and the other end portion is formed on the insulating film 11 in the first electrical connection metal layer 19. Formed on top. In short, in the sensor substrate 1 in the present embodiment, a step is formed between the surface of the heat insulating portion 14 on which the thermal infrared detecting portion 13 and the wiring layers 15 and 15 are formed and the bonding region portion E3, and the lead wiring 16 Is formed along the surface of the heat insulating portion 14. In the present embodiment, as the material of the wiring layers 15 and 15, the same material as that of the sensor layer constituting the thermal infrared detector 13 is employed (here, a laminated film of a Ti film and a TiN film), and the wiring layer. 15, 15 and the thermal infrared detector 13 are formed at the same time. In the present embodiment, a part of each of the first electrical connection metal layers 19, 19 constitutes a pad on the sensor substrate 1, and the thermal type is passed through the pair of first electrical connection metal layers 19, 19. The output of the infrared detector 13 can be taken out to the outside. In the present embodiment, since the film thickness of the lead wires 16 and 16 is set to be larger than the film thickness of the first electrical connection metal layer 19, disconnection of the lead wires 16 and 16 can be prevented. .

The leg portions 14b and 14b in the heat insulating portion 14 are held by the support post portions 14b ₂ and 14b ₂ erected on the one surface side of the base substrate portion 12 and the upper end portions of the support post portions 14b ₂ and 14b _2. The beam portions 14b ₁ and 14b ₁ are connected to the portion 14a, and a gap 17 is formed between the holding portion 14a and the base substrate portion 12. Here, the outer peripheral shape of the holding portion 14a is a rectangular shape, and each beam portion 14b ₁ , 14b ₁ extends from one end portion in the longitudinal direction of one side edge of the holding portion 14a in a direction orthogonal to the one side edge. Further, it is formed in a planar shape extending along the direction from the one end to the other end of the one side edge, and has rotational symmetry with respect to the central axis along the thickness direction of the holding portion 14a. Are arranged as follows. The line widths of the wiring layers 15 and 15 are set to be sufficiently smaller than the width dimensions of the beam portions 14b ₁ and 14b ₁ in order to suppress heat transfer through the wiring layers 15 and 15. Further, the support post portions 14 b ₂ and 14 b ₂ are reinforced by lead wires 16 and 16.

  Further, the leg portions 14b and 14b and the holding portion 14a of the heat insulating portion 14 are formed of a porous material having electrical insulation. Here, porous silica, which is a kind of porous silicon oxide, is adopted as the porous material of the legs 14b, 14b and the holding part 14a of the heat insulating part 14, but it is a kind of porous silicon oxide organic polymer. Methyl-containing polysiloxane, Si-H-containing polysiloxane which is a kind of porous silicon oxide-based inorganic polymer, silica aerogel, etc. may be employed. As the porous material, porous silicon oxide, If a material selected from the group consisting of a silicon oxide organic polymer and a porous silicon oxide inorganic polymer is employed, a sol-gel solution is spin-coated on the one surface side of the base substrate portion 12 in forming the heat insulating portion 14. Then, a drying process can be employed, and the heat insulating portion 14 can be easily formed.

  Here, the heat insulating portion 14 in the present embodiment is constituted by a porous silica film (porous silicon oxide film) having a porosity of 60%. However, if the porosity is too small, a sufficient heat insulating effect cannot be obtained and the porous section is porous. If the degree is too large, the mechanical strength becomes weak and it becomes difficult to form a structure. Therefore, the porosity of the porous silica film may be set as appropriate within a range of, for example, about 10% to 80%.

In the sensor substrate 1 described above, since the holding portion 14a in the heat insulating portion 14 is formed of a porous material, compared to a case where the holding portion 14a is formed of a non-porous material such as SiO ₂ or Si ₃ N _4. Thus, the heat capacity of the holding portion 14a can be reduced, and the response speed can be further increased. Furthermore, in the sensor substrate 1 according to the present embodiment, the leg portion 14b of the heat insulating portion 14 is also formed of a porous material, so the leg portion 14b is formed of a non-porous material such as SiO ₂ or Si ₃ N _4. Compared with the case where the thermal conductivity of the leg portion 14b is reduced, the sensitivity can be increased and the heat capacity of the leg portion 14b can be decreased and the response speed can be increased, so that the performance can be improved.

  Meanwhile, in the bonding region E3 of the sensor substrate 1, a frame-shaped (rectangular frame-shaped) first sealing metal layer 18 is formed on the above-described insulating film 11, and the plurality of first layers described above. The electrical connection metal layer 19 is formed on the insulating film 11 inside the first sealing metal layer 18. In short, in the sensor substrate 1, the first sealing metal layer 18 and each of the electrical connection metal layers 19 are formed on the same level surface with the insulating film 11 as a base layer with the same thickness.

  In the first sealing metal layer 18 and the first electrical connection metal layer 19, an adhesion improving Ti film is interposed between the bonding Au film and the insulating film 11. In other words, the first sealing metal layer 18 and the first electrical connection metal layer 19 are formed by a laminated film of a Ti film formed on the insulating film 11 and an Au film formed on the Ti film. It is configured. In short, since the first electrical connection metal layer 19 and the first sealing metal layer 18 are formed of the same metal material, the first electrical connection metal layer 19 and the first sealing metal layer 19 are formed. The metal layer 18 can be formed at the same time, and the first electrical connection metal layer 19 and the first sealing metal layer 18 can be formed to have substantially the same thickness. Note that the first sealing metal layer 18 and the first electrical connection metal layer 19 have a Ti film thickness of 15 to 50 nm and an Au film thickness of 500 nm. Is an example and is not particularly limited. Here, the material of each Au film is not limited to pure gold, and may be added with impurities. Further, in this embodiment, a Ti film is interposed as an adhesion improving adhesive layer between each Au film and the insulating film 11, but the material of the adhesion layer is not limited to Ti, and for example, Cr, Nb Zr, TiN, TaN, etc. may be used.

  On the other hand, the package substrate 2 is provided with a thermal insulation recess 21 that thermally insulates the thermal infrared detector 13 on one surface that is the surface on the sensor substrate 1 side. The package substrate 2 has a plurality of (two in this embodiment) through-holes 22 penetrating in the thickness direction in the peripheral portion of the thermal insulation recess 21, and the one surface and the other surface An insulating film 23 made of a thermal oxide film (silicon oxide film) is formed across the inner surface of each through hole 22, and between the through hole wiring 24 formed inside the through hole 22 and the inner surface of the through hole 22. A part of the insulating film 23 is interposed. Here, the package substrate 2 has a large opening area of the thermal insulation recess 21 so that the thermal infrared detection part 13 and the heat insulation part 14 of the sensor substrate 1 are within the projected region of the opening surface of the thermal insulation recess 21. It is. In addition, although Cu is employ | adopted as a material of the through-hole wiring 24, not only Cu but Ni etc. may be employ | adopted, for example. Further, the insulating film 23 in the package substrate 2 is not formed in the projection region of the opening surface of the thermal insulating recess 21.

  The package substrate 2 has a plurality of second electrical connection metal layers 29 electrically connected to the respective through-hole wirings 24 on the periphery of the thermal insulation recess 21 on the surface on the sensor substrate 1 side. Is formed. The package substrate 2 has a frame-shaped (rectangular frame-shaped) second sealing metal layer 28 formed over the entire circumference of the peripheral portion of the surface on the sensor substrate 1 side. The second electrical connection metal layer 29 is disposed inside the second sealing metal layer 28 (where the second sealing metal layer 28 and each electrical connection metal layer 29 are It is formed with the same thickness on the same level surface of the insulating film 23). Here, the outer peripheral shape of the second electrical connection metal layer 29 is rectangular, one end portion in the longitudinal direction is joined to the through-hole wiring 24, and the other end side portion is the first portion of the sensor substrate 1. The electrical connection metal layer 19 is joined and electrically connected. In short, the positions of the through-hole wiring 24 and the first electrical connection metal layer 19 corresponding to the through-hole wiring 24 are shifted, and the second electrical connection metal layer 29 is connected to the through-hole wiring 24 and the first electrical connection metal layer 19. It arrange | positions in the form straddling the metal layer 19 for electrical connection.

  In addition, the second sealing metal layer 28 and the second electrical connection metal layer 29 have an adhesion improving Ti film interposed between the bonding Au film and the insulating film 23. In other words, the second sealing metal layer 28 and the second electrical connection metal layer 29 are formed of a laminated film of a Ti film formed on the insulating film 23 and an Au film formed on the Ti film. It is configured. In short, since the second electrical connection metal layer 29 and the second sealing metal layer 28 are formed of the same metal material, the second electrical connection metal layer 29 and the second sealing metal layer 28 are formed. The metal layer 28 can be formed at the same time, and the second electrical connection metal layer 29 and the second sealing metal layer 28 can be formed to have substantially the same thickness. The second sealing metal layer 28 and the second electrical connection metal layer 29 have a Ti film thickness of 15 to 50 nm and an Au film thickness of 500 nm. Is an example and is not particularly limited. Here, the material of each Au film is not limited to pure gold, and may be added with impurities. In the present embodiment, a Ti film is interposed as an adhesion improving adhesive layer between each Au film and the insulating film 23. However, the material of the adhesion layer is not limited to Ti, and, for example, Cr, Nb Zr, TiN, TaN, etc. may be used.

  A plurality of external connection electrodes 25 electrically connected to the respective through-hole wirings 24 are formed on the surface of the package substrate 2 opposite to the sensor substrate 1 side. The outer peripheral shape of each external connection electrode 25 is rectangular.

  By the way, the sensor substrate 1 and the package substrate 2 are bonded to the first sealing metal layer 18 and the second sealing metal layer 28, and the first electrical connection metal layer 19. And the second metal layer 29 for electrical connection are joined. In manufacturing the infrared sensor of the present embodiment, a sensor wafer in which a plurality of sensor substrates 1 are formed on a first silicon wafer that is the basis of the first semiconductor substrate 10 described above, and a foundation of the second semiconductor substrate 20 described above. A dividing process (dicing process) in which a wafer level package structure is formed by bonding a package wafer formed with a plurality of package substrates 2 to a second silicon wafer to be room temperature bonded at a wafer level and then divided into individual infrared sensors. ) Are divided into individual infrared sensors. Therefore, the package substrate 2 and the sensor substrate 1 have the same outer size, so that a small chip size package can be realized and manufacture is facilitated. Here, in the infrared sensor of the present embodiment, the space surrounded by the sensor substrate 1 and the package substrate 2 is a vacuum atmosphere. In the present embodiment, as a method for bonding the sensor substrate 1 and the package substrate 2, a room temperature bonding method capable of bonding at a lower temperature is employed to reduce the residual stress (thermal stress) of the sensor substrate 1. Yes.

  Hereinafter, a method for manufacturing the sensor substrate 1 will be described with reference to FIG. Note that FIG. 3 shows a cross section of a portion corresponding to the cross section when FIG. 2 is cut in a step shape along A-A ′ and viewed from the direction of the arrow.

  First, by performing an insulating film forming step of forming an insulating film 11 made of a silicon nitride film on the main surface side of the first semiconductor substrate 10 by, for example, LPCVD, the structure shown in FIG.

  Thereafter, a sacrificial layer 31 made of polyimide is formed to form the heat insulating portion 14 on one surface side (the upper surface side in FIG. 3A) of the base substrate portion 12 made of the first semiconductor substrate 10 and the insulating film 11. By performing the sacrificial layer forming step, the structure shown in FIG. 3B is obtained.

  Subsequently, a porous film is formed by forming a porous film 140 made of a porous material (for example, porous silica, silica airgel, etc.) that is a material of the heat insulating part 14 on the entire surface of the base substrate part 12 on the one surface side. By performing the process, the structure shown in FIG. Here, when forming the porous film 140, when the porous material is porous silica, a process of spin-coating a sol-gel solution on the one surface side of the base substrate portion 12 and then drying by heat treatment is adopted. In the case where the porous material is silica aerogel, a process in which a sol-gel solution is spin-coated on the one surface side of the base substrate portion 12 and then dried by supercritical drying. Can be easily formed. In the present embodiment, the insulating film 11 and the porous film 140 that is an insulating film on the surface side of the insulating film 11 constitute a multilayer insulating film.

  After the porous film forming step described above, the entire surface on the one surface side of the base substrate portion 12 is composed of a laminated film of a Ti film and a TiN film that is the basis of the thermal infrared detector 13 and the wiring layers 15 and 15. The sensor material layer is formed by sputtering or the like, and then the sensor material layer is patterned by using a photolithography technique and an etching technique to form a part of the sensor material layer. The structure shown in FIG. 3D is obtained by performing a patterning process for forming the thermal infrared detector 13 and the wiring layers 15 and 15.

  Next, the porous film 140 is subjected to a porous film patterning process in which portions other than the portion formed in the portion corresponding to the heat insulating portion 14 are removed by etching using photolithography technology and etching technology. The structure shown in 3 (e) is obtained. In this embodiment, the porous film patterning step planarizes the surface of the bonding region E3 by etching back the portion of the multilayer insulating film formed in the bonding region E3. The insulating film 11 made of a silicon nitride film is used as an etching stopper layer in the etch back of the planarization process.

  Thereafter, by performing a first metal layer forming step of forming the first sealing metal layer 18 and the first electrical connection metal layer 19 on the surface of the insulating film 11 in the bonding region E3, FIG. The structure shown in 3 (f) is obtained. Therefore, in the multilayer insulating film formed on the main surface side of the first semiconductor substrate 10, the region where the thermal infrared detector 13 is formed, the first metal layer 18 for sealing, and the first metal layer for electrical connection. A step is formed with the bonding region E3 in which 19 is formed. Here, in the first metal layer forming step, a first sealing metal layer 18 and a first electrical connection metal layer 19 are formed on the main surface side of the first semiconductor substrate 10 by thin film formation such as sputtering. It is formed using technology, lithography technology, etching technology, and the like.

  After the first metal layer forming step, the lead wire forming step for forming the lead wire 16 on the main surface side of the first semiconductor substrate 10 is performed to obtain the structure shown in FIG. . Here, in the lead wiring formation step, the lead wiring 16 is formed on the main surface side of the first semiconductor substrate 10 by using a thin film forming technique such as a sputtering method, a lithography technique, an etching technique, and the like. Note that the order of the first metal layer forming step and the lead wiring forming step may be reversed.

  Thereafter, the gap 17 is formed by selectively removing the sacrificial layer 31 on the main surface side of the first semiconductor substrate 10 to obtain the sensor substrate 1 having the structure shown in FIG.

  Hereinafter, a method for manufacturing the package substrate 2 will be described with reference to FIG. 4 shows a cross section of a portion corresponding to the cross section A-A ′ of FIG. 2.

  First, after performing a thermal insulation recess formation process in which a thermal insulation recess 21 is formed on one surface of the second semiconductor substrate 20 by using a lithography technique, an etching technique, or the like, the second semiconductor substrate 20 is penetrated. A through-hole forming step of forming the holes 22 using lithography technology and etching technology is performed, and then the one surface side and the other surface side in the thickness direction of the second semiconductor substrate 20 and the inner peripheral surface of each through-hole 22 Then, a thermal oxidation process is performed to form an insulating film 23 made of a thermal oxide film (silicon oxide film) by a thermal oxidation method, and then a through-hole wiring 24 is formed using an electroplating technique and a CMP technique. The structure shown in FIG. 4A is obtained by performing the external connection electrode forming step of forming the external connection electrode 25 on the other surface side of the second semiconductor substrate 20 after performing the formation process. Get.

  Thereafter, by performing a second metal layer forming step of forming the second sealing metal layer 28 and the second electrical connection metal layer 29 on the one surface side of the second semiconductor substrate 20, FIG. The structure shown in (b) is obtained. Here, in the second metal layer forming step, a second sealing metal layer 28 and a second electrical connection metal layer 29 are formed on the one surface side of the second semiconductor substrate 20 by a sputtering method or the like. It is formed using a forming technique, a lithography technique, an etching technique, and the like.

  Thereafter, the insulating film 23 formed on the second semiconductor substrate 20 is formed in the projected region of the opening surface of the thermal insulation recess 21 among the portions formed on the one surface side and the other surface side. The package substrate 2 having the structure shown in FIG. 4C is obtained by etching away the existing portion.

  After forming the sensor substrate 1 and the package substrate 2 described above, the bonding metal layers 18 and 28 and the electrical connection metal layers 19 and 29 of the sensor substrate 1 and the package substrate 2 are directly bonded to each other. By performing the process, an infrared sensor having the structure shown in FIG. 1 is obtained. In short, in the bonding step, the metal layers 18 and 28 for sealing and the metal layers 19 and 29 for electrical connection between the sensor substrate 1 and the package substrate 2 are metal-metal (here, Au—Au) room temperature bonding. It is joined by. In the normal temperature bonding method, the bonding surfaces are contacted with each other after the bonding surfaces are cleaned and activated by irradiating the bonding surfaces with argon plasma, ion beam or atomic beam in vacuum before bonding. And bond directly at room temperature. Here, in the bonding step, the first sealing metal layer 18 and the second sealing metal layer 28 are directly bonded by applying an appropriate load at room temperature by the above-described room temperature bonding method. At the same time, the first electrical connection metal layer 19 and the second electrical connection metal layer 29 are directly joined.

  By the way, in the manufacturing method of the infrared sensor of this embodiment, the wafer level package provided with two or more infrared sensors by performing all processes until the above-mentioned joining process is completed for each of the sensor substrate 1 and the package substrate 2 at the wafer level. A structure is formed, and a dividing step (dicing step) for dividing the wafer level package structure into individual infrared sensors is performed. Therefore, the outer size (planar size) of the package substrate 2 can be matched with the outer size (planar size) of the sensor substrate 1, and the mass productivity can be improved.

  According to the manufacturing method of the infrared sensor of the present embodiment described above, the region for bonding with the package substrate 2 in the sensor substrate 1 in the multilayer insulating film formed on the main surface side of the first semiconductor substrate 10. After the surface of the bonding region E3 is flattened by etching back the portion formed in E3, the first sealing metal layer 18 and the first electric layer 18 are formed on the surface of the bonding region E3. Since the connecting metal layer 19 is formed, the first sealing metal layer 18 and the first electrical connecting metal layer 19 can be formed on the same level surface with the same thickness, and the first The flatness of the surface of the sealing metal layer 18 and the surface of the first electrical connection metal layer 19 can be improved, and the sealing metal layers 18 and 28 of the sensor substrate 1 and the package substrate 2 can be Metal layers for electrical connection 19, 29 It can enhance the yield of the bonding step of bonding directly, thereby improving the manufacturing yield. In the case where an insulating film made of, for example, a silicon oxide film is formed on the main surface side of the sensor substrate 1 as a protective film for protecting the thermal infrared detector 13, the first after the thermal infrared detector 13 is formed. A protective film is formed on the main surface side of the semiconductor substrate 10, and then a portion of the multilayer insulating film formed of the laminated film of the insulating film 11 and the protective film is etched back. Thus, the surface of the bonding region E3 is flattened, and then the first sealing metal layer 18 and the first electrical connection metal layer 19 are formed on the surface of the bonding region E3. Good.

  In the infrared sensor manufacturing method of this embodiment, the metal layers 18 and 28 for sealing and the metal layers 19 and 29 for electrical connection between the sensor substrate 1 and the package substrate 2 are bonded by metal-metal room temperature bonding. Since the bonded metal-metal combination is an Au-Au combination that is a chemically stable material, the manufacturing yield can be improved and the bonding stability can be improved. Here, the metal-metal combination is not limited to Au-Au, and may be, for example, a Cu-Cu combination or an Al-Al combination. In the case of a Cu-Cu combination, each metal layer for electrical connection 19 and 29 can be reduced in resistance, and in the case of an Al—Al combination, the material cost can be reduced compared to the case of adopting an Au—Au combination.

  Further, in the infrared sensor of the present embodiment, the second electrical connection is made at the joint portion of the second electrical connection metal layer 29 of the package substrate 2 with the first electrical connection metal layer 19 of the sensor substrate 1. Since the metal layer 29 is shifted from the connection site with the through-hole wiring 24, the surface smoothness of the second electrical connection metal layer 29 before joining the junction site with the first electrical connection metal layer 19 is as follows. (The smoothness of the surface when the second electrical connection metal layer 29 is formed can be improved), and the first electrical connection metal layer 19 and the second electrical connection metal layer 29 can be improved. As described above, it is possible to improve the bonding reliability in the case of direct bonding by the room temperature bonding method.

(Embodiment 2)
The basic configuration of the infrared sensor of the present embodiment is substantially the same as that of the first embodiment. As shown in FIGS. 5 and 6, the first metal layer 19 for electrical connection in the sensor substrate 1 is used for the first sealing. A difference is that a cutout portion 26 is formed on the outside of the metal layer 18 and exposes the first electrical connection metal layer 19 in the package substrate 2. In addition, the same code | symbol is attached | subjected to the component similar to Embodiment 1, and description is abbreviate | omitted. FIG. 5 corresponds to a schematic cross-sectional view of FIG. 6 taken along the line AA ′ and viewed from the direction of the arrow.

  In the present embodiment, the sensor substrate 1 includes a first oxide substrate 11 made of a thermal oxide film (silicon oxide film) formed on the main surface of the first semiconductor substrate 10 with the insulating film 11 on the main surface side of the first semiconductor substrate 10. The insulating film 11a and the second insulating film 11b made of a silicon nitride film on the first insulating film 11a are formed on the heat insulating part 14 made of a part of the insulating film 11, and the thermal infrared detecting part. 13 and wiring layers 15 and 15 are formed. Here, in the sensor substrate 1, the thermal-type infrared detector 13 and the first semiconductor substrate 10 are thermally insulated by the heat insulating portion 14 and the recess 10 a formed in the main surface of the first semiconductor substrate 10. In the present embodiment, a silicon substrate having an n-type conductivity and a main surface of (100) is used as the first semiconductor substrate 10, and the recess 10a has an alkaline solution (for example, a TMAH aqueous solution). It is formed by anisotropic etching using.

  Further, in the present embodiment, the lead-out wiring 16 that electrically connects the wiring layer 15 and the first electrical connection metal layer 19 is formed by the diffusion layer wiring formed on the main surface side of the first semiconductor substrate 10. The wiring layer 15 is electrically connected to the lead-out wiring 16 through the first contact hole CH1 (see FIG. 7C) opened in the insulating film 11, and becomes a pad for external connection. A second contact hole in which a first metal layer 19 for electrical connection is formed in a laminated film of an insulating film 11 and a protective film (third insulating film) 11c made of a silicon oxide film on the insulating film 11 The lead wire 16 is electrically connected through CH2 (see FIG. 7F). In the present embodiment, the first semiconductor substrate 10 is an n-type silicon substrate as described above, and the diffusion layer wiring constituting the lead-out wiring 16 is the main semiconductor substrate 10. It is formed by doping a p-type impurity such as boron in an appropriate part on the surface side. The first electrical connection metal layer 19 includes a contact portion 19a made of a laminated film of a Ti film formed on the lead wiring 16 and an Au film on the Ti film, and a Ti film on the contact portion 19a. The pad portion 19b is formed of a laminated film with the Au film on the Ti film. Here, in the pad portion 19b, the thickness of each of the Ti film and the Au film is set to be the same as the thickness of each of the Ti film and the Au film of the first sealing metal layer 18, and the first sealing is performed. The metal layer 18 is formed at the same time.

  On the other hand, in the package substrate 2, the insulating film 23 is formed on the peripheral portion of the thermal insulating recess 21 provided on one surface of the second semiconductor substrate 20, and the second sealing metal layer is formed on the insulating film 23. 28 is formed.

  Hereinafter, a method for manufacturing the sensor substrate 1 will be described with reference to FIGS. 7 and 8 show a cross section of a portion corresponding to a schematic cross section when FIG. 6 is stepped along A-A ′ and viewed from the direction of the arrow.

  First, by performing a lead wiring forming step of forming a lead wiring 16 made of a diffusion layer wiring on the main surface side of the first semiconductor substrate 10 by an ion implantation method, a thermal diffusion method, or the like, the structure shown in FIG. Get.

  Subsequently, a first insulating film forming step of forming a first insulating film 11a made of a thermal oxide film (silicon oxide film) on the main surface side of the first semiconductor substrate 10 by a thermal oxidation method is performed, By performing a second insulating film forming step for forming the second insulating film 11b made of a silicon nitride film by, for example, LPCVD, the structure shown in FIG. 7B is obtained.

  Thereafter, a first contact hole CH1 is formed in the insulating film 11 composed of the first insulating film 11a and the second insulating film 11b on the main surface side of the first semiconductor substrate 10 by using a lithography technique and an etching technique. By performing the first contact hole forming step, the structure shown in FIG. 7C is obtained.

  Subsequently, a sensor material layer composed of a laminated film of a Ti film and a TiN film serving as a basis for the thermal infrared detector 13 and the wiring layers 15 and 15 is formed on the entire main surface side of the first semiconductor substrate 10 by sputtering or the like. The sensor material layer is formed by the following steps, followed by patterning the sensor material layer using a photolithography technique and an etching technique, thereby forming the thermal infrared detector 13 and a part of the sensor material layer respectively. By performing a patterning process for forming the wirings 15, the structure shown in FIG. 7D is obtained.

  Thereafter, a protective film forming step of forming a protective film 11c made of a silicon oxide film on the entire main surface side of the first semiconductor substrate 10 by a plasma CVD method or the like is performed, thereby obtaining the structure shown in FIG. .

  Subsequently, a second contact for forming a second contact hole CH2 in the multilayer insulating film composed of the insulating film 11 and the protective film 11c on the main surface side of the first semiconductor substrate 10 by using a lithography technique and an etching technique. By performing the hole forming step, the structure shown in FIG.

  Thereafter, a laminated film of a Ti film and an Au film serving as the basis of the contact portion 19a is formed on the entire surface of the first semiconductor substrate 10 on the main surface side. Subsequently, the laminated film is subjected to a photolithography technique and an etching technique. A structure shown in FIG. 8A is obtained by performing a contact portion forming step of forming the contact portion 19a by patterning using it.

  Thereafter, the portion formed in the bonding region E3 is etched in the multilayer insulating film formed of the laminated film of the insulating film 11 on the main surface side of the first semiconductor substrate 10 and the protective film 11c on the insulating film 11. A structure shown in FIG. 8B is obtained by performing a flattening step of flattening the surface of the bonding region E3 by backing. Here, in the etch back in the planarization step, the second insulating film 11b made of a silicon nitride film is used as an etching stopper layer.

  Thereafter, by performing a first metal layer forming step of forming the first sealing metal layer 18 on the surface of the bonding region E3 and forming the pad portion 19b on the contact portion 19a, FIG. The structure shown in c) is obtained. Therefore, in the multilayer insulating film formed on the main surface side of the first semiconductor substrate 10, the region where the thermal infrared detector 13 is formed and the bonding region E3 where the first sealing metal layer 18 is formed. A step is formed between the two. Here, in the first metal layer formation step, the first sealing metal layer 18 and the pad portion 19b are formed on the main surface side of the first semiconductor substrate 10 by a thin film formation technique such as sputtering, lithography technique, and etching. It is formed using technology.

  After the first metal layer forming step described above, the recess 10a is formed on the main surface of the first semiconductor substrate 10 using an anisotropic etching technique using an alkaline solution (for example, a TMAH aqueous solution). By performing the recess forming step, the sensor substrate 1 having the structure shown in FIG. 8D is obtained.

  Next, a method for manufacturing the package substrate 2 will be described with reference to FIG. 9 shows a cross section of a portion corresponding to the A-A ′ cross section of FIG. 6.

  First, after the insulating film 23 is formed on the one surface side of the second semiconductor substrate 20, a portion corresponding to the region where the thermal insulating recess 21 is to be formed is patterned using the lithography technique and the etching technique in the insulating film 23. Then, by performing a thermal insulation recess forming step for forming a thermal insulation recess 21 on one surface of the second semiconductor substrate 20 using the patterned insulating film 23 as a mask, FIG. 9A shows. Get the structure.

  Subsequently, a structure shown in FIG. 9B is obtained by performing a notch forming process in which the above-described notch 26 is formed in the second semiconductor substrate 20 by using a lithography technique and an etching technique.

  Thereafter, by performing a second metal layer forming step of forming the second sealing metal layer 28 on the one surface side of the second semiconductor substrate 20, the package substrate having the structure shown in FIG. Get 2. Here, in the second metal layer forming step, the second sealing metal layer 28 is applied to the one surface side of the second semiconductor substrate 20 by a thin film forming technique such as a sputtering method, a lithography technique and an etching technique. It is formed using.

  After forming each of the sensor substrate 1 and the package substrate 2 described above, a bonding step of directly bonding the sealing metal layers 18 and 28 between the sensor substrate 1 and the package substrate 2 is performed, as shown in FIG. An infrared sensor having a structure is obtained. In short, in the bonding step, the sealing metal layers 18 and 28 of the sensor substrate 1 and the package substrate 2 are bonded to each other by metal-metal (here, Au—Au) normal temperature bonding. In the normal temperature bonding method, the bonding surfaces are contacted with each other after the bonding surfaces are cleaned and activated by irradiating the bonding surfaces with argon plasma, ion beam or atomic beam in vacuum before bonding. And bond directly at room temperature. Here, in the bonding step, the first sealing metal layer 18 and the second sealing metal layer 28 are directly bonded by applying an appropriate load at room temperature by the above-described room temperature bonding method. Yes.

  By the way, in the manufacturing method of the infrared sensor of this embodiment, the wafer level package provided with two or more infrared sensors by performing all processes until the above-mentioned joining process is completed for each of the sensor substrate 1 and the package substrate 2 at the wafer level. Since the structure is formed and the dividing process (dicing process) for dividing the wafer level package structure into the individual infrared sensors is performed, mass productivity can be improved.

  In the infrared sensor of the present embodiment, the sensor substrate 1 and the package substrate 2 can be joined only by room-temperature joining between the sealing metal layers 18 and 28, so that the sealing metal layer 18, as in the first embodiment, Compared with a configuration in which room-temperature bonding between 28 and the metal layers 19 and 29 for electrical connection is also necessary, the bonding reliability can be improved.

  In the infrared sensor of this embodiment, since the first electrical connection metal layer 19 is exposed, the back surface of the sensor substrate 1 is mounted on the circuit board side when mounted on a circuit board or the like. The first metal layer 19 for electrical connection and the conductor pattern of the circuit board can be electrically connected via the bonding wire.

(Embodiment 3)
The basic configuration of the infrared sensor of the present embodiment is substantially the same as that of the first embodiment. As shown in FIG. 10, an IC portion E <b> 2 is formed on the main surface side of the first semiconductor substrate 10 in the sensor substrate 1. The difference is that the lead wiring 16 electrically connected to the thermal infrared detector 13 is electrically connected to the first electrical connection metal layer 19 via the IC part E2. In addition, the same code | symbol is attached | subjected to the component similar to Embodiment 1, and description is abbreviate | omitted.

  The IC unit E2 integrates an output circuit of the thermal infrared detector 13 with an amplifier circuit, a window comparator at the subsequent stage of the amplifier circuit, and the like.

  Thus, in the infrared sensor of the present embodiment, the wiring length between the thermal infrared detector 13 and the IC part E2 can be shortened, and noise entering from the wiring connecting the two can be prevented, and the sensitivity is increased. Can be planned.

  In the infrared sensor according to the present embodiment as well, as in the first embodiment, the second electrical connection metal layer 29 of the package substrate 2 is joined to the first electrical connection metal layer 19 of the sensor substrate 1. Is shifted from the connection portion with the through-hole wiring 24 in the second electrical connection metal layer 29, the second electrical connection metal layer 29 is joined to the first electrical connection metal layer 19. The smoothness of the surface before joining the parts can be increased (the smoothness of the surface when the second electrical connection metal layer 29 is formed can be increased), and the first electrical connection metal layer 19 and As described above, it is possible to increase the bonding reliability when the second electric connection metal layer 29 is directly bonded by the room temperature bonding method as described above.

(Embodiment 4)
The basic configuration of the infrared sensor of the present embodiment is substantially the same as that of the first embodiment, and as shown in FIG. 11, the base substrate portion 12 in the sensor substrate 1 includes the first semiconductor substrate 10 and the first semiconductor substrate 10. An insulating film 11 made of a silicon nitride film formed on the main surface side and an insulating film 10d made of a silicon nitride film formed on the back surface side, and an opening portion 12a penetrating in the thickness direction in the base substrate portion 12 is formed. The difference is that the hole portion 12 a is formed and closed by the heat insulating portion 14 on the main surface side of the first semiconductor substrate 10. Here, the sensor substrate 1 has a heat insulating portion 14 formed in a diaphragm shape. In this embodiment as well, as in the first embodiment, the region where the thermal infrared detector 13 is formed in the multilayer insulating film formed on the main surface side of the first semiconductor substrate 10 and the first sealing A step is formed between the bonding region E3 where the metal layer 18 is formed. Since other configurations are the same as those of the first embodiment, description thereof is omitted.

(Embodiment 5)
The basic configuration of the infrared sensor of the present embodiment is substantially the same as that of the first embodiment, and as shown in FIG. 12, a through-hole electrically connected to the sensor substrate 1 to the first metal layer 19 for electrical connection. The wiring 124 is formed, and the external connection electrode 125 electrically connected to the through-hole wiring 124 is formed on the back surface of the sensor substrate 1. In addition, the same code | symbol is attached | subjected to the component similar to Embodiment 1, and description is abbreviate | omitted.

  In the sensor substrate 1 according to the present embodiment, a plurality of (two in the present embodiment) through-holes 122 penetrating in the thickness direction are formed in the first semiconductor substrate 10, and the main substrate of the first semiconductor substrate 10 is formed. An insulating film 11 a made of a thermal oxide film (silicon oxide film) is formed across the front surface, the back surface, and the inner surface of each through hole 122, and the through hole wiring 124 formed inside the through hole 122 and the inner surface of the through hole 122 A part of the insulating film 11a is interposed between the two. The material of the through-hole wiring 124 is Cu, but is not limited to Cu. For example, Ni may be used.

  In the infrared sensor of the present embodiment, the sensor substrate 1 and the package substrate 2 can be joined only by room-temperature joining between the sealing metal layers 18 and 28, so that the sealing metal layer 18, as in the first embodiment, Compared with a configuration in which room-temperature bonding between 28 and the metal layers 19 and 29 for electrical connection is also necessary, the bonding reliability can be improved.

  Further, in the infrared sensor of the present embodiment, the external connection electrode 125 is formed on the back surface side of the sensor substrate 1, and therefore, when mounted on a circuit board or the like, the mounting area can be reduced. There is.

(Embodiment 6)
The basic configuration of the infrared sensor of this embodiment is substantially the same as that of the first embodiment, and the structure of the sensor substrate 1 is different as shown in FIG. In addition, the same code | symbol is attached | subjected to the component similar to Embodiment 1, and description is abbreviate | omitted.

  In the sensor substrate 1 according to the present embodiment, the insulating film 11 on the main surface side of the first semiconductor substrate 10 is formed of a thermal oxide film (silicon oxide film) on the main surface side of the first semiconductor substrate 10. The film 11a and the second insulating film 11b made of a silicon nitride film on the first insulating film 11a are formed on the heat insulating part 14 made of a part of the insulating film 11 and the thermal infrared detecting part 13 and Wiring layers 15 and 15 are formed. Here, in the sensor substrate 1, the thermal-type infrared detecting unit 13 and the base substrate unit 12 are thermally insulated by a heat insulating unit 14 and a recess 10 a formed in the main surface of the first semiconductor substrate 10. In the present embodiment, a silicon substrate having an n-type conductivity and a main surface of (100) is used as the first semiconductor substrate 10, and the recess 10 a has an alkaline solution (for example, a TMAH aqueous solution). Etc.).

  In addition, a protective layer (third insulating film) 11c made of a silicon oxide film that protects the thermal infrared detector 13 and the wiring layers 15 and 15 is formed on the main surface side of the first semiconductor substrate 10. On the surface of the bonding region portion E3 flattened by etching back the portion corresponding to the bonding region portion E3 of the multilayer insulating film formed of the insulating film 11 and the protective layer 11c, the first seal is formed. A stop metal layer 18 and a first electrical connection metal layer 19 are formed. The lead-out wiring 16 is electrically connected to the wiring layer 15 through a contact hole formed in the protective layer 11c.

  Thus, in the infrared sensor of the present embodiment, the thermal infrared detector 13 and the wiring layers 15 and 15 are protected by the protective layer 11c, so that moisture and the like are adsorbed to the thermal infrared detector 13 and the wiring layer 15. Can be suppressed.

  In the infrared sensor according to the present embodiment as well, as in the first embodiment, the second electrical connection metal layer 29 of the package substrate 2 is joined to the first electrical connection metal layer 19 of the sensor substrate 1. Is shifted from the connection portion with the through-hole wiring 24 in the second electrical connection metal layer 29, the second electrical connection metal layer 29 is joined to the first electrical connection metal layer 19. The smoothness of the surface before joining the parts can be increased (the smoothness of the surface when the second electrical connection metal layer 29 is formed can be increased), and the first electrical connection metal layer 19 and As described above, it is possible to increase the bonding reliability when the second electric connection metal layer 29 is directly bonded by the room temperature bonding method as described above.

  By the way, although the infrared sensor demonstrated by each above-mentioned embodiment is comprised by the substrate 2 for packages sealed on the main surface side of the sensor substrate 1 and the sensor substrate 1, depending on the structure of the sensor substrate 1, Of course, a package substrate may be separately sealed on the back side of the sensor substrate 1.

  The infrared sensor described in each of the above-described embodiments is an infrared sensor provided with only one thermal infrared detector 13, but the thermal infrared detector 13 is two-dimensionally arranged on the main surface side of the sensor substrate 1. It may be an infrared image sensor arranged in an array (matrix) so that each thermal infrared detector 13 constitutes a pixel.

It is a schematic sectional drawing of the infrared sensor of Embodiment 1. It is a schematic perspective view of the sensor board | substrate in the same as the above. It is principal process sectional drawing for demonstrating the manufacturing method of the sensor substrate in the same as the above. It is principal process sectional drawing for demonstrating the manufacturing method of the board | substrate for packages in the same as the above. It is a schematic sectional drawing of the infrared sensor of Embodiment 2. It is a schematic perspective view of the sensor board | substrate in the same as the above. It is principal process sectional drawing for demonstrating the manufacturing method of the sensor substrate in the same as the above. It is principal process sectional drawing for demonstrating the manufacturing method of the sensor substrate in the same as the above. It is principal process sectional drawing for demonstrating the manufacturing method of the board | substrate for packages in the same as the above. It is a schematic sectional drawing of the infrared sensor of Embodiment 3. It is a schematic sectional drawing of the infrared sensor of Embodiment 4. It is a schematic sectional drawing of the infrared sensor of Embodiment 5. It is a schematic sectional drawing of the infrared sensor of Embodiment 6. It is a schematic sectional drawing which shows a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sensor substrate 2 Package substrate 10 1st semiconductor substrate 13 Thermal infrared detection part 14 Heat insulation part 15 Wiring layer 16 Lead-out wiring 17 Gap | interval 18 1st metal layer for sealing 19 1st metal layer for electrical connection 20 1st 2 semiconductor substrate 28 second metal layer for sealing 29 second metal layer for electrical connection E3 bonding region

Claims (5)

  The sensor substrate includes at least a sensor substrate having a thermal infrared detector formed on the main surface side of the semiconductor substrate and a package substrate sealed on the main surface side of the sensor substrate. Sensor device in which the formed metal layers for sealing are bonded at room temperature, and the sensor substrate is a thermal infrared ray in a multilayer insulating film formed of a laminated film of a plurality of insulating films formed on the main surface side of the semiconductor substrate A step is formed between the region where the detecting portion is formed and the bonding region where the sealing metal layer is formed, and the bonding is flattened by etching back a part of the multilayer insulating film. A sensor device comprising a sealing metal layer formed on a surface of a region portion.   In the sensor substrate, a first electric connection metal layer electrically connected to the thermal infrared detection unit is formed on the surface of the bonding region portion, and the package substrate includes a first electric connection. A second electrical connection metal layer bonded to the connection metal layer is formed, and a through-hole wiring electrically connected to the second electrical connection metal layer is formed, and the sensor substrate and The sensor device according to claim 1, wherein the package substrate is formed by joining activated metal layers for electrical connection at room temperature.   The sensor substrate is formed with an IC unit that cooperates with the thermal infrared detector on the main surface side of the semiconductor substrate, and the thermal infrared detector is connected to the first through the IC unit. The sensor device according to claim 2, wherein the sensor device is electrically connected to the metal layer for electrical connection.   A method of manufacturing a sensor device using at least a sensor substrate having a thermal infrared detector formed on a main surface side of a semiconductor substrate and a package substrate sealed on the main surface side of the sensor substrate, A bonding region by etching back a portion formed in a bonding region portion with a package substrate in a multilayer insulating film composed of a plurality of insulating films formed on the main surface side of the semiconductor substrate on the substrate A flattening step of flattening the surface of the portion, a metal layer forming step of forming a sealing metal layer on the surface of the bonding region portion after the flattening step, and activation of the sensor substrate and the package substrate And a bonding step of bonding the sealed metal layers at room temperature to each other.   A wafer level package structure including a plurality of the sensor devices is formed by performing all the processes until the bonding process is completed at the wafer level for each of the sensor substrate and the package substrate. The method for manufacturing a sensor device according to claim 4, further comprising a dividing step of dividing a body into the sensor device.

Images