JP2008003081A - Infrared sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an infrared sensor in which a detection element is supported stably at a prescribed height position over a substrate, while improving the thermal insulation performance of an infrared detection element. <P>SOLUTION: The infrared detection element 30 is held on a sensor seating 40 made of a porous material, and leads 32 extending from the detection element 30 are supported at the upper ends of anchor protrusions 52, protruding from terminal lands 50 in the upper surface of a substrate 10. The leads 32 are formed in beams 42, extending from the sensor seating 40, and one ends of the beams 42 are connected to the upper ends of the anchor protrusions 52. The anchor protrusions support the detection element 30, in a form of being separated from the upper surface of the substrate 10 via the leads 32 and support the sensor seating 40 at the substrate 10 via the beams 42. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an infrared sensor in which a thermal infrared detection element is arranged on a substrate.

  Patent document 1 is disclosing the infrared sensor comprised with a thermal type infrared detection element and a semiconductor device, and these are arrange | positioned side by side on the upper surface of a semiconductor base material. The thermal infrared sensing element is held by a sensor pedestal formed on the upper surface of the semiconductor substrate and supported by a beam extending from the sensor pedestal to the rest of the substrate. The sensor pedestal and the beam are constituted by a part of the upper surface of the base material, and are transformed into a porous structure to thermally insulate the infrared detection element from the rest of the base material. That is, the sensor base and the beam are formed in the porous body by anodizing the upper part of the doped region formed on the upper surface of the semiconductor substrate. Thus, the prior art makes good use of the semiconductor substrate to realize a sensor pedestal in the upper surface of the substrate. However, since the sensor pedestal is limited within the upper surface of the substrate, it is virtually impossible to form a semiconductor device in the semiconductor substrate directly below the sensor pedestal or sensing element. In particular, since the porous beam extends only within the upper surface of the semiconductor substrate, the sensor base cannot be lifted upward from the upper surface of the substrate.

Patent Document 2 discloses another prior art, in which the sensor pedestal is supported separately from the base material, and the detection element is sufficiently thermally insulated from the base material by mounting the infrared detection element. In this case, the sensor pedestal is supported by a beam extending obliquely outward and downward from the sensor pedestal and reaching the substrate. The beam and the sensor pedestal are formed of silicon oxide or silicon nitride, and are considered to have sufficient strength to indicate the sensor pedestal and the sensing element in a state of being separated from the upper surface of the substrate. It will be appreciated that the above support structure using an angled beam while relaxing is not suitable for accurately holding the infrared sensing element at a predetermined height. Accurate positioning with respect to the height position is particularly important when a plurality of sensing elements are arranged in a two-dimensional array. As can be seen in Document 1, when a high thermal insulation is performed using a beam or sensor base as a porous material, it is difficult to stably support the detection element with a support structure using an oblique beam. A unique design that cannot be derived from 2 is required.
US Pat. No. 6,359,276 JP 2000-97765 A

  The present invention has been made in view of the above-described problems. In order to hold the infrared detection element on the upper surface of the base material in a separated manner, it is possible to use a porous material. An infrared sensor having a useful structure that can be held accurately and stably at a predetermined height is realized.

  An infrared sensor according to the invention of claim 1 includes a base material and a sensor unit held on the base material. The sensor unit includes a thermal infrared detection element, a sensor pedestal on which the detection element is mounted, a pair of beams that extend integrally from the sensor pedestal to the base material and support the sensor pedestal upward from the upper surface of the base material, And terminal lands formed on the upper surface of the substrate. The sensor pedestal and beam are formed of a porous material to sufficiently insulate the thermal infrared sensing element from the substrate. The sensing element has a pair of leads, each lead supported on a corresponding beam, extending along the beam and electrically connected to a corresponding terminal land.

  The lead is held by a beam extending in a state of being separated from the upper surface of the substrate in the same plane as the sensor base. The sensor unit further includes an anchor projection protruding upward from each terminal land, and each anchor projection is coupled at its upper end to the tip of each corresponding lead in the sensing element. For this reason, the sensing element is supported on the base material by the anchor protrusion together with the sensor base, and is held in a separated form on the base material. In this state, the sensing element is electrically connected to the terminal land on the base material via the anchor protrusion. Connected. Because of this configuration, the anchor projection will support the lead and thus the sensing element, and will hold the sensing element at a constant height above the substrate. Furthermore, the upper end of each anchor projection is embedded in the corresponding beam and surrounded by the beam. For this reason, the beam of porous material is securely coupled to the corresponding anchor projection, and the sensor pedestal is coupled to the anchor projection to back up the sensing element. Therefore, the infrared detection element can be accurately maintained at a predetermined height with the infrared detection element being reliably backed up by the sensor base or beam of the porous material, and between the upper surface of the substrate. High thermal insulation performance can be obtained.

  In the invention of claim 2, each lead is formed on each corresponding beam by vapor deposition. In this case, the upper end of each anchor projection is received in a hole formed at the end of the corresponding beam, and a flange formed at the upper end of each anchor projection overlaps with the beam around the hole and is coupled to the corresponding lead. This flange provides a large contact area between the anchor projection and the beam, thereby increasing the intermolecular bonding force between the beam of porous material and the anchor projection, so that the beam and the sensor pedestal have a certain height above the upper surface of the substrate. Can be held in.

  According to the third aspect of the present invention, each lead and the corresponding anchor protrusion are formed of a common electrically conductive material and are continuous with each other, and the lead and the anchor protrusion can be formed in a single process. .

  In the invention of claim 4 or 5, the lead and the anchor protrusion are formed in separate steps, and a part of the flange of each anchor protrusion overlaps with the corresponding lead and is joined here. In this case, the anchor protrusion preferably has a uniform thickness larger than that of the lead. According to this configuration, the anchor protrusion is given sufficient mechanical strength to support the infrared detection element and the sensor base, while the lead can be thinned to increase the sensitivity of the infrared detection element.

  In the invention according to claims 6 and 7, the anchor protrusion is surrounded by a sleeve made of a porous material along its vertical length, so that thermal insulation can be performed around the anchor protrusion. This sleeve also serves to support one end of the beam. In this case, it is preferable for manufacturing that the sleeve is integrally formed as a part of the beam.

  In the invention of claim 8, the sensor pedestal is formed of a porous material selected from the group consisting of silicon oxide, silicon oxide organic polymer, and silicon oxide type inorganic polymer, and can effectively insulate the thermal infrared detecting element. .

  In the invention of claim 9, an array of a plurality of sensor units is arranged on a common substrate. In this case, the detection element of each unit is maintained at a certain height from the upper surface of the base material, and a uniform and uniform output can be taken out from each sensor unit.

  According to a tenth aspect of the present invention, a sealing cap is provided that is coupled to a base material to form an airtight space therebetween, and the sensor unit is accommodated in the airtight space. A window is provided that allows infrared to pass through the thermal infrared sensing element.

In the invention of claim 11, the hermetic space is decompressed to enhance the thermal insulation between the infrared detecting element and the substrate.
In the invention of claim 12 or 13, a lens array in which a plurality of optical lenses are arranged is provided in the window, and the incident infrared rays are converged on any thermal infrared detection element of the sensor unit, and each sensor unit Infrared rays can be collected effectively from a wide range. In this case, it is preferable that the lens array is molded integrally with the sealing cap to form a part of the sealing cap in order to reduce the number of components.
In the invention of claim 14, the lens array is laminated on the window on the surface of the sealing cap facing the sensor unit, and the refractive index of the lens array is made smaller than the refractive index of the window. Therefore, since the incident infrared rays travel through the medium whose refractive index decreases toward the sensing element, they are generated at the interface between the window and the external atmosphere, the interface between the window and the lens, and the interface with the medium in the airtight space of the lens. The overall loss of reflection can be reduced and the sensitivity can be increased by increasing the amount of infrared light received by the infrared sensing element.

  With the infrared sensing element securely backed up by the porous material sensor pedestal and beam, the infrared sensing element can be accurately maintained at a predetermined height, and high heat between the top surface of the substrate Insulation performance can be obtained.

  An infrared sensor according to a first embodiment of the present invention is shown in FIGS. As shown in FIGS. 4 to 6, the infrared sensor of the present invention includes a plurality of sensor units 100 and the sensor units are arranged in a two-dimensional array to constitute a thermal image sensor. It is not limited. The sensor unit 100 is formed in common on a single semiconductor substrate 10 and is accommodated in an airtight space formed between the substrate 10 and the sealing cap 200 coupled thereto. This hermetic space is depressurized and thermally isolated from the surroundings. The sealing cap 200 is formed of silicon and has a window 202 that transmits infrared rays, and guides the infrared rays to the sensor unit 100. A lens array including a plurality of convex lenses 204 is integrally formed on the window 202, and each convex lens 204 collects infrared rays corresponding to each sensor unit 100.

  As shown in FIG. 1 and FIG. 2, each sensor unit 100 includes a semiconductor device 20 formed in the upper surface of the semiconductor substrate 10, and a thermal infrared that is supported by the substrate 10 in a form separated from the semiconductor device 20. A sensing element 30. The semiconductor device 20 is electrically connected to the infrared detection element 30 to provide a sensor output to an external processing circuit, where the sensor output is the infrared detection element for temperature measurement and determination of the presence of an object that emits infrared rays. The amount of infrared light received at 30 is analyzed.

The semiconductor device 20 is, for example, a MOSFET transistor, and gives a sensor output by turning on and off in response to a trigger signal. This transistor is formed in the upper surface of the substrate 10 by a known technique, and includes a doped region 21 having a drain 22 and a source 23, a gate 24, a drain electrode 25, a source electrode 26, and a gate electrode 28. These electrodes are electrically connected to terminal pads exposed on the upper surface of the substrate 10. Hereinafter, the phrase “transistor” will be used to indicate the semiconductor device 20, but the present invention is not limited to using a single transistor as shown. An insulating layer 12 of, for example, SiO ₂ or SiN is formed over substantially the entire top surface of the base material 10 to cover the transistor 20 on the back side. When the transistor 20 is connected to the electrode on the upper surface of the substrate, the insulating layer 12 is formed so as to cover the entire surface of the upper surface of the substrate except for the electrode.

As shown in FIG. 1 and FIG. 2, each sensor unit 100 is integrally extended from the opposite sides of the sensor pedestal 40 and the sensor pedestal 40 holding the detection element 30 in the same plane as the sensor pedestal. A pair of horizontal beams 42 to be supported and a pair of terminal lands 50 formed on the upper surface of the substrate 10 are provided. The thermal infrared sensing element 30 is formed in a patterned strip of metal such as titanium deposited on the sensor pedestal 40 and provides an electrical resistance value that varies in proportion to the amount or intensity of incident infrared radiation. A pair of conductors, that is, leads 32, extending along the top of 40 and electrically connected to each terminal land 50 are provided. Sensor base 40 and beam 42 are formed of a porous material to effectively thermally isolate infrared sensing element 30 from substrate 10 and transistor 20. The porous material used in the present embodiment is porous silica (SiO ₂ ), but a silicon oxide organic polymer or a silicon oxide inorganic polymer may be used.

  An anchor protrusion 52 is formed on each terminal land 50, and the anchor protrusion protrudes upward to hold the tip of the corresponding beam 42 so that the sensor pedestal 40 is disposed at a height position above the upper surface of the substrate 10. Thus, the sensing element is maintained in a separated state above the upper surface of the substrate 10 and directly above the transistor 20. The anchor protrusion 52 is formed of the same material as the sensing element 30 and is coupled to the lead 32 at the upper end thereof. As shown in FIGS. 7 and 8, the anchor protrusion 52 has a hollow cylindrical shape, and its upper end is accommodated in a hole 44 formed at the end of the corresponding beam 42. A flange 54 formed at the upper end of the anchor projection 42 overlaps the beam 42 around the hole 44, and one peripheral portion is connected to the end of the lead 32 running on the beam 42. Since the lead 32 is integrated with the vertical anchor protrusion 52 on the base material 10, the infrared detecting element 30 is supported on the base material 10 by the lead 32 and the anchor protrusion 52, and corresponds to the length of the anchor protrusion 52 accurately. Is maintained at a position separated from the upper surface of the substrate 10 at a height to be adjusted. As described below, sensing element 30 and lead 32 are deposited on sensor pedestal 40 and beam 42, respectively, to create an intermolecular bonding force, thereby securing sensor pedestal 40 and beam 42 to sensing element 30 and lead 32, respectively. To do. As a result, the sensor pedestal 40 and the beam 42 are held by the lead 32 coupled to the sensing element 30 and the anchor protrusion 52, and are thus supported on the substrate 10 by the anchor protrusion 52. Since the anchor protrusion 52 fits in the hole 44 at the end of the beam 42, the end of the beam 42 surrounds the entire upper periphery of the anchor protrusion 52, and as a result, the anchor due to the intermolecular bonding force around the hole 44 Coupled to the upper end of the protrusion, it securely supports the beam 42 and sensor pedestal 40 and the anchor protrusion 52 or substrate 10. Furthermore, since the flange 54 provides a large bonding area over the entire circumference of the hole 44 with the beam 42, the intermolecular bonding force here is added to stably support the beam 42 to the anchor protrusion 52.

  As shown in FIG. 3, the terminal land 50 is provided with pads 55 and 57 connected to the reference voltage source Vref and the source electrode 26 of the transistor 20. A gate electrode (not shown in FIG. 2) is connected to a terminal pad 28 via a buried line 27 and is connected to an external circuit that controls on / off of the transistor 20. The drain electrode 25 is connected to the terminal pad 16 through a buried line 29, and provides a sensor output to an external circuit for detecting infrared rays from the target object.

  An infrared reflector 17 made of a metal such as aluminum is formed on the insulating upper layer 12 to reflect the infrared rays passing through the infrared detecting element 30 so as to return here, thereby increasing the sensitivity. The distance between the infrared detecting element 30 and the reflector 17 is d = λ / 4 (λ is the wavelength of infrared rays from the target object). When this infrared sensor is used for human body detection, since the wavelength (λ) of infrared light from the human body is 10 μm, this distance is set to 2.5 μm.

  The porosity of the porous material is preferably 40% to 80%, and provides sufficient mechanical strength and good thermal insulation effect.

Porous silica (SiO ₂ ) has an excellent thermal insulation effect and minimizes the thermal conductance from the beam 42 to the substrate, while minimizing the heat capacity of the sensor base 40 and improving the sensitivity of the infrared sensor. .

The sensor unit having the above-described configuration is manufactured through the processes shown in FIGS. After forming the transistor 20 on the upper surface of the semiconductor substrate 10, an insulating upper layer 12 of SiO ₂ is formed by thermal oxidation to cover the entire upper surface of the semiconductor substrate 10 as shown in FIG. Alternatively, the SiN insulating upper layer 12 is formed by a CVD method. Next, after the aluminum layer is formed on the insulating upper layer 12 by sputtering, this is selectively removed by etching, so that the terminal land 50 and the infrared reflector 17 are formed on the insulating upper layer 12 as shown in FIG. Form. Thereafter, as shown in FIG. 9C, a sacrificial layer 60 of an appropriate resist material is applied on the insulating upper layer 12 by spin coating. In addition to this, the sacrificial layer 60 may be formed of polyimide by spin coating, metal deposition, or polysilicon by CVD. Next, as shown in FIG. 9D, a porous silica (SiO ₂ ) solution is applied onto the sacrificial layer 60 by spin coating to form a porous layer 70. Thereafter, the porous layer 70 is masked with an appropriate resist and selectively removed by etching, thereby forming the sensor pedestal 40 and the beam 42 as shown in FIG. A through-hole 72 that passes through the layer 60 and reaches the terminal land 50 is formed. The through holes 72 are formed by lithography, dry etching, or wet etching. Next, after the titanium electric conductor layer 80 is deposited on the sensor base 40, the beam 42, and the through hole 72 by sputtering as shown in FIG. 9F, a protective layer made of titanium nitride is coated by sputtering. . Thereafter, the conductor layer 80 and the protective layer are selectively etched away to form a patterned strip of the infrared sensing element 30 on the sensor pedestal 40, the lead 32 on the beam 42, and the through holes 72. The anchor projection 52 is formed together with the flange 54 to complete the electrical connection between the sensing element 30 and the terminal land 50 as shown in FIG. In this way, the anchor protrusion 52 is continuous with the lead 32 and the sensing element 30, and these members are combined into a single structure. Finally, the sacrificial layer 60 is removed by etching to obtain a sensor unit as shown in FIG.

  Titanium or chromium is used as a conductive material for forming the sensing element 30, the lead 32, and the anchor protrusion 52, and is covered with titanium nitride or gold. The sensing element 30, the lead 32, and the anchor protrusion 52, which are a single structure, desirably have a uniform thickness of about 0.05 μm to 0.5 μm.

  FIGS. 10 and 11 show a modification of the above-described embodiment, which is the same as the above-described embodiment except that the anchor protrusion 52 is formed separately from the lead 32 and coupled thereto. This change mode is useful for increasing the sensitivity to incident infrared rays by reducing the thickness of the lead 32 and the detection element 30 while stably supporting the detection element 30 and the sensor base 40 to the anchor protrusion 52. For example, the thickness of the sensing element 30 and the lead 32 is 0.2 μm, and the anchor protrusion 52 is 0.2 μm or more. In this modification, the end of the lead 32 is coupled to a part of the flange 54 in an overlapping manner, so that the sensing element 30 is supported by the anchor protrusion 52.

12 (A) to 12 (H) show a process of manufacturing the sensor unit of this modified mode. As shown in FIG. 12A, after the terminal land 50 and the infrared reflector 17 are formed on the insulating upper layer 12 of the equipment 0 having the transistor 20 formed in the upper surface, as shown in FIG. Further, a sacrificial layer 60 of an appropriate resist material is applied to the entire upper surface of the insulating upper layer 12 by spin coating. Next, as shown in FIG. 12C, a porous silica (SiO ₂ ) solution is applied onto the sacrificial layer 60 by spin coating to form a porous layer 70. Thereafter, the porous layer 70 is masked with an appropriate resist and selectively removed by etching to form the sensor pedestal 40 and the beam 42 as shown in FIG. A through-hole 72 that passes through the layer 60 and reaches the terminal land 50 is formed. Next, as shown in FIG. 12E, after the titanium or chromium electric conductor layer 80 is deposited on the sensor base 40 or the beam 42 by sputtering, a titanium nitride or gold protective film is coated by sputtering. The After that, as shown in FIG. 12 (F), the conductor layer 80 and the protective film are selectively etched away, and the patterned strip of the infrared detecting element 30 is placed on the beam 42 on the sensor base 40. Lead 32 is formed. A titanium or chromium electrically conductive material is partially deposited on the end of the through hole 72 and the lead 32 by sputtering to a thickness larger than that of the sensing element 30 and the lead 32, and then this material is selectively etched away. As shown in FIG. 12G, the anchor protrusion 52 is formed. In this process, the anchor protrusion 52 is coupled to the lead 32 at the flange 54 portion, whereby the sensing element 30, the lead 32, the sensor base 40, and the beam 42 are supported by the anchor protrusion 52. Finally, the sacrificial layer 60 is removed by etching to obtain a sensor unit as shown in FIG.

  13 to 15 show a sensor unit according to the second embodiment of the present invention, which is the same as the first embodiment except for the structure of the thermal infrared detection element 30A. About the same member, "A" is attached | subjected to the end of the same number, and the overlapping description is omitted.

The thermal infrared detecting element 30A is configured by disposing an amorphous silicon resistance layer 130 between a lower electrode 131 and an upper electrode 132, and the electrodes are connected to the terminal land 50A via leads 32A, respectively. The resistance layer 130 exhibits a resistance that changes according to a change in the amount of incident infrared rays between the upper and lower electrodes. The infrared detection element 30A is placed on the sensor base 40A and supported by the anchor protrusion 52A together with the sensor base 40A. The anchor protrusion 52A is deposited on the terminal land 50A and protrudes upward from the terminal land 50A. A flange 54A formed at the upper end of the anchor protrusion 52A is integrally coupled with the lead 32A extending from the upper and lower electrodes 131 and 132, respectively. Therefore, the entire sensing element 30A including the lead 32A is integrated with the anchor protrusion 52A and is supported on the base material 10A in a separated manner. The pair of beams 42A extend integrally from the sensor base 40 made of a porous material and hold the leads 32A thereon, whereby the detection elements 30A and the leads 32A are thermally insulated from the base material. Each anchor protrusion 52A is surrounded by a sleeve 46 integral with the beam 42A, as shown in FIG. The beam 42A and the sleeve 46 are bonded to the lead 32A and the anchor protrusion 52A by intermolecular force, respectively, and are supported to the base material 10A via the anchor protrusion 52A. An infrared absorber 134 is deposited on the upper electrode 132 to efficiently collect infrared rays. The infrared absorber 134 is formed of SiON, Si ₃ N ₄ , SiO ₂ or gold black.

A process of manufacturing the sensor unit will be described with reference to FIGS. 16 (A) to 16 (K). After the transistor 20A is formed on the single crystal silicon semiconductor substrate 10A, as shown in FIG. 16A, the entire upper surface of the semiconductor substrate 10A is covered with a SiO ₂ insulating upper layer 12A formed by thermal oxidation. Next, the aluminum layer is coated on the insulating upper layer 12A by sputtering, and this is selectively etched away. As shown in FIG. 16B, the terminal land 50A and the infrared reflector 17A are formed on the insulating upper layer 12A. Leave. Thereafter, as shown in FIG. 16C, a sacrificial layer 60A of an appropriate resist material is applied to the entire surface of the insulating upper layer 12A by spin coating, and a part of the sacrificial layer 60A is removed by etching. As shown in (D), a through-hole 62A that exposes each terminal land 50A is formed. Next, porous silica (SiO ₂ ) is applied to the entire upper surface of the sacrificial layer 60A by spin coating to form the porous layer 70A extending from the top of the sacrificial layer into the through-hole 62A, and then FIG. As shown in FIG. 4, a part of the porous material in one through hole 62A is partially removed by etching to form a through hole 72A reaching the terminal land 50A.

  Next, after vapor-depositing chromium on the porous layer 70A and in the through holes 72A by sputtering, a part thereof is removed by etching, and as shown in FIG. 16 (F), on the porous layer 70A, At the same time as forming the lower electrode 131 and the corresponding lead 32A, the anchor protrusion 52A surrounded by the sleeve 45 of the porous material is formed. Thereafter, amorphous silicon is deposited on the porous layer 70A through the lower electrode 131 by the CVD method, and this is selectively removed by etching. As shown in FIG. Layer 130 is formed. Thereafter, the porous layer 70A extending into the remaining through-holes 62A is selectively removed by etching, and as shown in FIG. 16 (H), another through-hole 72A exposes the corresponding terminal land 50A. Thus formed. Next, after chromium is deposited on the porous layer 70A and the resistance layer 130, a part thereof is selectively removed by etching, and as shown in FIG. 16 (I), the upper electrode 132 and the upper electrode are removed. An extending lead 32A is formed. In this process, chromium is deposited in the through holes 72A to form anchor protrusions 52A, which anchor leads 32A are connected to corresponding terminal lands 50A. In this way, the lead 32A of the detection element 30A is integrated with the anchor protrusion 52A, and the detection element 30A is supported on the base material 10A by the anchor protrusion 52A. Next, after depositing a SiON layer on the porous layer 70A via the upper electrode 132 and the corresponding lead 32A, the SiON layer is removed by etching, and as shown in FIG. Absorber 134 is formed. The porous base layer 70A is masked with an appropriate resist and selectively removed by etching to form the sensor base 40A and the beam 42A, and then the sacrificial layer 60A is removed by etching to obtain a sensor unit shown in FIG. Is obtained.

  In the above-described embodiment, the porous layer and the corresponding member are formed of porous silica, but the present invention can use other porous materials, such as methyl-containing polysiloxane. Siloxane-based organic polymers, siloxane-based inorganic polymers such as SiH-containing siloxane, and silica airgel can be used.

Further, the porous material may be a porous matrix composition comprising hollow fine particles and a matrix forming material. The hollow fine particles are particles having a hollow portion surrounded by an outer shell, and a metal oxide or silica is preferable as the outer shell. The hollow fine particles are selected from those disclosed in Japanese Patent Publication No. 2001-233611 or commercially available. In particular, as the outer shell, SiO ₂ , SiO _x , TiO ₂ , TiO _x , SnO ₂ , CeO ₂ , Sb ₂ O ₅ , ITO, ATO, Al ₂ O ₃ , or any combination of these materials Selected from a mixture of The porous matrix composition forms a porous layer having a low thermal conductivity and a low specific heat after being coated on a substrate and dried. In the porous layer, the hollow fine particles are dispersed as a filler and are trapped in the matrix. The matrix-forming material includes a first type silicon compound having a siloxane bond, or a second type silicon compound that provides a siloxane bond when forming a film or layer. The second type silicon compound may have a siloxane bond. Examples of the first-type and second-type silicon compounds include organic silicon compounds, silicon halide compounds (for example, silicon chloride and silicon fluoride), and organic silicon halide compounds containing an organic group and halogen.

  17 to 19 show various configurations for the lens array used in the present invention. Each sensor unit 100 is arranged in a unit square constituting one pixel of the infrared sensor. Correspondingly, each lens 204 of the lens array is a circular convex lens having a diameter shorter than one side in a unit square as shown in FIG. 17, or a circular convex lens equal to this one side as shown in FIG. Alternatively, as shown in FIG. 19, a convex lens having a square shape in plan view covering the entire unit square can be obtained.

FIG. 20 shows a modification of the above-described embodiment. An array of separate convex lenses 204 is added to the window 202 of the sealing cap 200 on the surface facing the sensor unit 100. These lenses are shown in FIG. Is made smaller than the refractive index of the window 202, that is, the sealing cap 200. For example, the sealing cap 200 is made of Si having a refractive index of 3.4, and the lens 204 is made of SiO ₂ having a refractive index of 1.5. Such a configuration reduces the total amount of each reflection that occurs at the individual interfaces between the different media while the infrared light travels through the window and lens to the sensing element 30 and transmits infrared light through the sealing cap 200. It is effective in improving the rate. The sealing cap 200 can be formed of other materials, such as Ge, InP, ZnSe, ZnS, Al ₂ O ₃ , CdSe, and the lens has an appropriate material having a smaller refractive index than the sealing cap. Can be teased. Further, the window 202 can be covered with a transmission film having a refractive index smaller than that of the sealing cap on the outer surface opposite to the lens, so that the infrared transmittance can be further increased.

In the above-described embodiment, an example is shown in which an infrared sensor showing an electrical resistance value that changes in accordance with the amount and rate of change of incident infrared rays is shown. However, the dielectric constant changes in accordance with changes in the amount of incident infrared rays. A thermopile type that generates a thermoelectromotive force or a pyroelectric type that generates a voltage difference can be used. Further, in the above embodiment, the infrared sensor of the present invention uses a plurality of sensor units. However, the present invention is not limited to this particular configuration and includes the use of a single sensor unit. In the illustrated embodiment, it is shown that the substrate is provided with the semiconductor device. However, the present invention should be construed to include other modified embodiments not including the semiconductor device.

The perspective view of the sensor unit used for the infrared sensor which concerns on the 1st Embodiment of this invention. 2-2 sectional drawing in FIG. The circuit diagram of a sensor unit same as the above. The perspective view of an infrared sensor same as the above. Sectional drawing of an infrared sensor same as the above. The exploded perspective view of an infrared sensor same as the above. The expansion perspective view of a part of sensor unit same as the above. FIG. 8 is a cross-sectional view taken along line 8-8 in FIG. 7. Sectional drawing which shows the manufacturing process of a sensor unit same as the above in (A)-(H). The fragmentary perspective view which shows a part of change aspect of a sensor unit same as the above. FIG. 11 is a sectional view taken along line 11-11 in FIG. 10; Sectional drawing which shows the manufacture process of the change aspect of a sensor unit same as the above in (A)-(H). The expansion perspective view of the sensor unit concerning a 2nd embodiment of the present invention. 14 is a sectional view taken along line 14-14 in FIG. Sectional drawing which shows a part of sensor unit same as the above. Sectional drawing which shows the manufacturing process of the sensor unit of FIG. 13 by (A)-(K) of FIG. 16A thru | or FIG. 16B. Sectional drawing which shows the manufacturing process of the sensor unit of FIG. 13 by (A)-(K) of FIG. 16A thru | or FIG. 16B. The perspective view which shows the change aspect of an infrared sensor same as the above. The perspective view which shows the change aspect of an infrared sensor same as the above. The perspective view which shows the change aspect of an infrared sensor same as the above. Sectional drawing which shows another modification of an infrared sensor same as the above.

Explanation of symbols

10, 10A Base material 20, 20A Semiconductor device 30, 30A Infrared sensing element 32, 32A Lead 40, 40A Sensor base 42, 42A Beam 44 Hole 50, 50A Terminal land 52, 52A Anchor protrusion 54, 54A Flange 100, 100A Sensor unit 200 Sealing cap 202 Window 204 Lens

Claims (14)

An infrared sensor including a base material and a sensor unit,
The sensor unit
Thermal infrared sensing element,
A sensor base formed of a porous material for holding the infrared sensor;
A pair of beams formed of the porous material and integrally extending from the sensor pedestal toward the base material, and supporting the sensor pedestal upwardly spaced from the upper surface of the base material;
It is composed of terminal lands formed on the upper surface of the base material,
The thermal infrared detecting element includes a pair of leads, each lead is supported on the upper surface of the beam and extends along the beam and is electrically connected to the corresponding terminal land.
The beam extends in a form spaced apart from the upper surface of the substrate in the same plane as the sensor pedestal, and holds the leads.
The sensor unit is provided with an anchor protrusion protruding upward from each of the terminal lands, and each anchor protrusion is coupled to the tip of the corresponding lead at the upper end thereof so that the detection element is combined with the sensor base. , Supported on the base material in a form spaced from the upper surface of the base material, and the sensing element is electrically connected to the terminal land through the anchor protrusion,
An infrared sensor, wherein an upper end of each anchor protrusion is embedded in a corresponding beam and surrounded by the beam. Each of the above leads is formed on each corresponding beam by vapor deposition,
The upper end of each anchor projection is received in a hole 44 formed at the tip of each beam,
2. The infrared sensor according to claim 1, wherein a flange formed at an upper end of each anchor protrusion is engaged with each beam by being locked around the hole of each beam. The infrared sensor according to claim 2, wherein each of the leads and the corresponding anchor protrusion corresponding to the leads are formed of a common electrically conductive material and are continuous with each other. The infrared sensor according to claim 2, wherein a part of the flange of each anchor protrusion overlaps with an end of each lead and is joined to each other. 5. The infrared sensor according to claim 4, wherein each of the anchor protrusions has a hollow cylindrical shape, and a thickness thereof is larger than a thickness of each of the leads. 2. The infrared sensor according to claim 1, wherein each of the anchor protrusions is surrounded by a sleeve made of a porous material along a vertical length thereof. The infrared sensor according to claim 6, wherein the sleeve is integrally formed as a part of the beam. 2. The infrared sensor according to claim 1, wherein the sensor base is formed of a porous material selected from the group consisting of silicon oxide, silicon oxide organic polymer, and silicon oxide-type inorganic polymer. The infrared sensor according to claim 1, wherein an array of the plurality of sensor units is arranged in common on the base material. A sealing cap that is coupled to the base material to form an airtight space therebetween is provided, and the sensor unit is accommodated in the airtight space, and the incident infrared rays are transmitted to the thermal infrared ray in the sealing cap. The parasitic infrared sensor according to claim 1, further comprising a window through which the detection element passes. The infrared sensor according to claim 10, wherein the airtight space is decompressed. 11. The infrared sensor according to claim 10, wherein a lens array in which a plurality of optical lenses are arranged is provided in the window, and the incident infrared rays are converged on any thermal infrared detection element of the sensor unit. The infrared sensor according to claim 11, wherein the lens array is molded integrally with the sealing cap to constitute a part of the sealing cap. 12. The lens array according to claim 11, wherein the lens array is stacked on the window on a surface of a sealing cap facing the sensor unit, and the refractive index of the lens array is smaller than the refractive index of the window. Infrared sensor.

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