JP2014239147A - Infrared sensor and method of manufacturing the infrared sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simply keep an interval between a first semiconductor substrate and a second semiconductor substrate substantially fixed when the first semiconductor substrate and the second semiconductor substrate are joined together in a hybrid manner.SOLUTION: A first semiconductor substrate 2 and a second semiconductor substrate 3 are jointed together in a hybrid manner. The first semiconductor substrate 2 has a photodetector array 21 on a first main surface 2d. A plurality of photodetectors 2b of the photodetector array 21 are arranged in a lattice shape on the first main surface 2d. The photodetector array 21 and a plurality of height adjustment members are provided between the first main surface 2d and a second main surface 3a of the second semiconductor substrate 3. The plurality of height adjustment members are arranged in a density of one piece or more per unit area of 1 mmin an array area 21a where the photodetector array 21 out of the first main surface 2d is provided.

Description

The present invention relates to an infrared sensor and a method for manufacturing the infrared sensor.

Patent Document 1 discloses a solid-state imaging device and a method for manufacturing the solid-state imaging device. The solid-state image sensor of Patent Document 1 includes a first semiconductor substrate and a second semiconductor substrate. The first semiconductor substrate includes a photoelectric conversion unit. The photoelectric conversion unit arranges photodiodes one-dimensionally or two-dimensionally and photoelectrically converts incident light. The second semiconductor substrate includes a signal processing unit. The signal processing unit arranges the input diodes one-dimensionally or two-dimensionally and reads the signal converted by the photoelectric conversion unit. The solid-state imaging device of Patent Document 1 is a hybrid solid-state imaging device that is electrically connected and integrated by a bump provided for each input diode. A concave portion or a convex portion is provided in a region other than the region where the photoelectric conversion portion of the first semiconductor substrate is formed. Protrusions or recesses that fit into the recesses or protrusions are provided in regions other than the region where the signal processing unit 5 of the second semiconductor substrate is formed. In the invention of Patent Document 1, concave-convex fitting is used in order to prevent lateral displacement at the time of joining the first semiconductor substrate and the second semiconductor substrate.

Patent Document 2 discloses a bonding method. In the bonding method of Patent Document 2, when the first semiconductor substrate and the second semiconductor substrate are opposed to each other and the element region and the connection region facing each other are connected by the connection conductor, the connection conductor is melted. A force is applied in a direction in which the distance between the first semiconductor substrate and the second semiconductor substrate is increased. The element region of the first semiconductor substrate is two-dimensionally arranged. The second semiconductor substrate has connection regions arranged two-dimensionally at the same pitch as the element region. In the invention of Patent Document 2, an interval adjusting member is used in order to prevent a vertical bonding failure when bonding the first semiconductor substrate and the second semiconductor substrate.

Patent Document 3 discloses a semiconductor device and a method for manufacturing the semiconductor device. In the semiconductor device of Patent Document 3, an insulating member is inserted between the first semiconductor chip and the second semiconductor chip. A large number of bumps of the first semiconductor chip 1 and a large number of bumps of the second semiconductor chip are joined. The first semiconductor chip forms an HgCdTe diode array. The second semiconductor chip forms a Si-CCD. The insulating member is not fixed to either the first semiconductor chip 2 or the second semiconductor chip 2, separating all two adjacent bonded bodies of the plurality of bumps. In the invention of Patent Document 3, it is intended that the short circuit in the lateral direction is prevented by separating the joints for each pixel with polyimide.

JP-A-7-38076 JP 2002-299650 A JP-A-7-153905

In Patent Document 1, an etching (dry etching) process for forming irregularities is required, and the number of steps is large, so that the manufacturing cost increases. In Patent Document 2, since the inter-chip gap at the time of In bump bonding cannot be fixed, bonding unevenness may occur in the initial bonding state, thus reducing the bonding yield. In Patent Document 3, even if a short circuit in the lateral direction can be prevented, it is difficult to suppress unevenness in joining in the height direction, as in Patent Document 2, so that the joint yield decreases. Furthermore, in the techniques of Patent Documents 1 to 3, since there is no protection on the sensor incident surface at the time of bonding, the appearance yield of the sensor light receiving surface is reduced.

An object of the present invention is to reduce pixel defects by simply maintaining a substantially constant distance between a first semiconductor substrate and a second semiconductor substrate when a first semiconductor substrate and a second semiconductor substrate are hybrid-bonded. It is to realize an infrared sensor.

An infrared sensor according to the present invention includes a first semiconductor substrate, a second semiconductor substrate, and a plurality of height adjusting members, and the first semiconductor substrate and the second semiconductor substrate are hybrid bonded. The first semiconductor substrate includes a light receiving element array, the light receiving element array is provided on a first main surface of the first semiconductor substrate, and includes a plurality of light receiving elements; The plurality of light receiving elements are arranged in a lattice pattern on the first main surface, and the plurality of height adjusting members are arranged in an array region of the first main surface where the light receiving element array is provided. The first semiconductor substrate is arranged at a density of 1 or more per unit area of 1 mm ² , and the second semiconductor substrate is electrically output from each of the plurality of light receiving elements via the second main surface of the second semiconductor substrate. A simple optical signal And is electrically connected to each of the plurality of light receiving elements via the second main surface, and the light receiving element array and the plurality of height adjusting members are The first main surface and the second main surface are provided between the first main surface and the second main surface.

The plurality of height adjusting members are uniformly dispersed at a density of one or more per unit area of 1 mm ^{2 in} the array region, so that they are used as products from the time of joining the first semiconductor substrate and the second semiconductor substrate. Thus, the distance between the first semiconductor substrate and the second semiconductor substrate can be kept uniform (regardless of the location on the first main surface) and constant. Since the distance between the first semiconductor substrate and the second semiconductor substrate is kept uniform and constant, the deflection of the first semiconductor substrate is reduced, so that the back surface of the first semiconductor substrate exposed to the outside of the infrared sensor ( The deflection of the light receiving surface) of the infrared sensor is also reduced, and thus the appearance abnormality of the infrared sensor can be reduced. Furthermore, since an unexpected electrical short circuit between the first semiconductor substrate and the second semiconductor substrate due to the bending of the first semiconductor substrate can be reduced, dot dropping can be reduced in the light receiving element array.

In the infrared sensor according to the present invention, the first semiconductor substrate or the second semiconductor substrate includes a groove portion, and the groove portion is formed when the groove portion is provided on the first semiconductor substrate. A grid shape that is provided on one main surface, or on the second main surface when the groove is provided on the second semiconductor substrate, and that matches the grid-like arrangement of the plurality of light receiving elements. The injection port is an opening for introducing the height adjustment member into the groove portion, and the plurality of height adjustment members are arranged in the array region, In terms of density, it is preferably distributed in the array region along the groove. The plurality of height adjusting members are uniformly distributed inside the array region by the lattice-shaped grooves.

In the infrared sensor according to the present invention, in a state where the height adjusting member is disposed in the groove portion provided with the first semiconductor substrate, the height from the first main surface is the height adjusting member. Is preferably higher than the light receiving element. Therefore, the height adjusting member reliably contacts the first semiconductor substrate and the second semiconductor substrate, so that the distance between the first semiconductor substrate and the second semiconductor substrate can be reliably maintained constant.

In the infrared sensor according to the present invention, it is preferable that a shape of the height adjusting member is a sphere. Since the shape of the height adjustment member is a sphere, the movement of the height adjustment member in the groove portion is facilitated. Therefore, each of the plurality of height adjustment members can be arranged uniformly without being biased over the entire groove portion. It becomes.

In the infrared sensor according to the present invention, it is preferable that a material of the height adjusting member is quartz. Since the height adjusting member is quartz having a relatively high hardness, deformation due to stress received from the first semiconductor substrate and the second semiconductor substrate is avoided.

The infrared sensor according to the present invention includes a reinforcing member, the reinforcing member is filled between the first main surface and the second main surface, and a material of the reinforcing member is a resin. Is preferred. When the reinforcing member is used together with the plurality of height adjusting members, the distance between the first semiconductor substrate and the second semiconductor substrate is more uniform from the time when the first semiconductor substrate and the second semiconductor substrate are joined to the time when they are used as products. (Regardless of the location on the first main surface) and more constant. Furthermore, the arrangement of the height adjusting member can be more reliably fixed by the reinforcing member.

An infrared sensor manufacturing method according to the present invention includes a step of preparing a first semiconductor substrate and a second semiconductor substrate, and a step of hybrid-bonding the first semiconductor substrate and the second semiconductor substrate, The first semiconductor substrate includes a light receiving element array, and the light receiving element array is provided on a first main surface of the first semiconductor substrate, includes a plurality of light receiving elements, and the plurality of light receiving elements. Are arranged in a lattice pattern on the first main surface, and the second semiconductor substrate is electrically output from each of the plurality of light receiving elements via the second main surface of the second semiconductor substrate. When the first semiconductor substrate or the second semiconductor substrate is provided with a groove portion, and the groove portion is provided in the first semiconductor substrate. In the first main surface, Is provided on the second main surface when the groove is provided on the second semiconductor substrate, and has a lattice shape that matches the lattice arrangement of the plurality of light receiving elements. And an injection port, and the injection port is an opening for introducing a height adjusting member disposed between the first semiconductor substrate and the second semiconductor substrate into the groove portion, and the first semiconductor The step of preparing the substrate and the second semiconductor substrate includes the step of injecting the plurality of height adjusting members contained in a volatile solvent together with the volatile solvent into the groove portion through the injection port. And a step of dispersing the plurality of height adjusting members in the array region in which the light receiving element array is provided in the first main surface. member in the array area, 1 mm ² They are arranged in one or more of a density per unit area, characterized in that.

The plurality of height adjusting members are injected into the groove together with the volatile solvent, and are uniformly dispersed at a density of one or more per unit area of 1 mm ^{2 in} the array region. Therefore, the first semiconductor substrate and the second semiconductor The interval between the first semiconductor substrate and the second semiconductor substrate can be kept uniform (regardless of the location on the first main surface) and constant from when the substrate is bonded to when it is used as a product. It becomes possible. The plurality of height adjusting members are uniformly distributed inside the array region by the lattice-shaped grooves. Since the distance between the first semiconductor substrate and the second semiconductor substrate is kept uniform and constant, the deflection of the first semiconductor substrate is reduced, so that the back surface of the first semiconductor substrate exposed to the outside of the infrared sensor ( The deflection of the light receiving surface) of the infrared sensor is also reduced, and thus the appearance abnormality of the infrared sensor can be reduced. Furthermore, since an unexpected electrical short circuit between the first semiconductor substrate and the second semiconductor substrate due to the bending of the first semiconductor substrate can be reduced, dot dropping can be reduced in the light receiving element array.

In the infrared sensor manufacturing method according to the present invention, the first semiconductor substrate includes a light receiving surface, the light receiving surface is on the opposite side of the first main surface, and the first semiconductor substrate and the second semiconductor substrate are provided. The step of preparing the semiconductor substrate includes a step of providing a protective sheet covering the light receiving surface on the light receiving surface, and the step of providing the protective sheet is performed before the step of injecting and dispersing the plurality of height adjusting members. Preferably, in the step of hybrid bonding the first semiconductor substrate and the second semiconductor substrate, the first semiconductor substrate and the second semiconductor substrate are preferably hybrid bonded using the protective sheet. By covering the light receiving surface with the protective sheet, the light receiving surface can be protected from scratches and foreign matters.

In the infrared sensor manufacturing method according to the present invention, it is preferable that the groove portion is formed by a space between the plurality of light receiving elements arranged in a lattice shape. Therefore, the process cost is reduced as compared with the case where grooves are actually provided on the first main surface of the first semiconductor substrate.

In the infrared sensor manufacturing method according to the present invention, the material of the height adjusting member is preferably quartz. Since the height adjusting member is quartz having a relatively high hardness, deformation due to stress received from the first semiconductor substrate and the second semiconductor substrate is avoided.

In the infrared sensor manufacturing method according to the present invention, the volatile solvent is preferably an alcohol solvent. Therefore, the volatile solvent can be volatilized efficiently.

In the infrared sensor manufacturing method according to the present invention, in the state in which the height adjusting member is disposed in the groove provided in the first semiconductor substrate, the height from the first main surface is the height. It is preferable that the height adjusting member is higher than the light receiving element. Therefore, the height adjusting member reliably contacts the first semiconductor substrate and the second semiconductor substrate, so that the distance between the first semiconductor substrate and the second semiconductor substrate can be reliably maintained constant.

According to the present invention, when the first semiconductor substrate and the second semiconductor substrate are hybrid-bonded, the distance between the first semiconductor substrate and the second semiconductor substrate can be easily kept substantially constant.

Drawing 1 is a figure for explaining the internal structure of the infrared sensor concerning an embodiment. FIG. 2 is a view for explaining the configuration of the first semiconductor substrate of the infrared sensor according to the embodiment. FIG. 3 is a view for explaining the configuration of the groove of the first semiconductor substrate according to the embodiment. FIG. 4 is a flowchart showing a plurality of main steps in the method of manufacturing the infrared sensor according to the embodiment. FIG. 5 is a diagram for explaining a method of manufacturing the infrared sensor according to the embodiment. FIG. 6 is a diagram for explaining a method of manufacturing the infrared sensor according to the embodiment. FIG. 7 is a diagram for explaining a method of manufacturing the infrared sensor according to the embodiment. FIG. 8 is a diagram illustrating another configuration of the first semiconductor substrate of the infrared sensor according to the embodiment. FIG. 9 is a diagram illustrating another configuration of the first semiconductor substrate of the infrared sensor according to the embodiment.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the description of the drawings, if possible, the same elements are denoted by the same reference numerals, and redundant description is omitted.

With reference to FIGS. 1-3, the structure of the infrared sensor 1 which concerns on embodiment is demonstrated. FIG. 1 is a diagram for explaining the internal structure of the infrared sensor 1. FIG. 1 is a view of the internal structure of the infrared sensor 1 as seen from the plane along the stacking direction of the first semiconductor substrate 2 and the second semiconductor substrate 3. FIG. 2 is a diagram for explaining the configuration of the first semiconductor substrate 2 of the infrared sensor 1. FIG. 2 is a view of the first semiconductor substrate 2 as viewed obliquely from above the first main surface 2d of the first semiconductor substrate 2. FIG. 3 is a diagram for explaining the configuration of the groove 2 c of the first semiconductor substrate 2. FIG. 3 is a diagram showing a configuration in the region R1 shown in FIG. The region R1 is a region of the first main surface 2d of the first semiconductor substrate 2. The configuration included in the region R1 illustrated in FIG. 2 is the same as the configuration provided in another region of the first main surface 2d.

The infrared sensor 1 includes a first semiconductor substrate 2, a second semiconductor substrate 3, and a plurality of height adjusting members 4. The first semiconductor substrate 2 and the second semiconductor substrate 3 are hybrid bonded. The plurality of height adjusting members 4 are disposed between the first semiconductor substrate 2 and the second semiconductor substrate 3. The hybrid joining means that a plurality of parts having different functions are joined electrically or physically. In the case of this embodiment, the first semiconductor substrate 2 performs photoelectric conversion, and the second semiconductor substrate 3 performs signal readout for each pixel. These substrates have In solder bumps. The medium is bonded by a heat melting process (flip chip bonding).

The first semiconductor substrate 2 includes a semiconductor stack 2a, a light receiving element 2b, a groove 2c, a first main surface 2d, and a light receiving surface 2e. The semiconductor laminate 2a includes a low reflection coating film 2a1, a support base 2a2, and an n-type layer 2a3. A support base 2a2 is provided on the low reflection coating film 2a1, an n-type layer 2a3 is provided on the support base 2a2, and a plurality of light receiving elements 2b are provided on the n-type layer 2a3.

The first semiconductor substrate 2 includes a groove 2c. The groove 2c is provided on the first main surface 2d. The groove 2c has a lattice shape that matches the lattice arrangement of the plurality of light receiving elements 2b. The groove 2c is provided with an inlet 2c1. The inlet 2c1 is an opening for introducing the height adjusting member 4 into the groove.

The first semiconductor substrate 2 includes a light receiving element array 21. The light receiving element array 21 is provided on the first main surface 2 d of the first semiconductor substrate 2. The light receiving element array 21 includes a plurality of light receiving elements 2b. The light receiving element 2b has a mesa shape on the first main surface 2d. The light receiving element 2b is a photodiode. The light receiving element 2b includes a p-side electrode provided at the end of the mesa of the light receiving element 2b. The shape of the groove 2c is defined by the mesa shape of the light receiving element 2b. That is, the groove 2c is formed by a space between the plurality of light receiving elements 2b arranged in a lattice shape. In this case, a region surrounding the array region 21a protrudes from the first main surface 2d, and the injection port 2c1 is embedded in this region. In addition, the groove part 2c may be comprised by actually providing a groove | channel in the exposed 1st main surface 2d between the some light receiving elements 2b.

As shown in FIG. 2, the plurality of light receiving elements 2b are arranged in a lattice pattern on the first main surface 2d. The distance between two adjacent light receiving elements 2b corresponds to the pixel interval and is, for example, about 8 μm. As shown in FIG. 2, the plurality of height adjusting members 4 are arranged at a density of one or more per unit area of 1 mm ² in the array region 21 a where the light receiving element array 21 is provided on the first main surface 2 d. ing. The plurality of height adjusting members 4 are dispersed in the array region 21a at the above density along the groove 2c in the array region 21a. The material of the height adjusting member 4 is a high hardness material, for example, quartz. The height adjusting member 4 is a sphere. In a state where the height adjusting member 4 is disposed in the groove 2c provided with the first semiconductor substrate 2, the height from the first main surface 2d is higher in the height adjusting member 4 than in the light receiving element 2b. high. The height of the light receiving element 2b from the first main surface 2d is, for example, about 5 μm, and the diameter of the height adjusting member 4 is, for example, about 10 μm.

Material of the low-reflective coating film 2a1 is, for example, SiON, SiN, a dielectric such as SiO _2. The material of the support base 2a2 is, for example, InP. The material of the n-type layer 2a3 is, for example, n-type Si or n-type InP.

The first semiconductor substrate 2 includes a light receiving surface 2e. The light receiving surface 2e is on the opposite side of the first main surface 2d. The light receiving surface 2e corresponds to the surface of the low reflection coating film 2a1.

The second semiconductor substrate 3 is a circuit board for reading out an electrical optical signal output from each of the plurality of light receiving elements 2b of the first semiconductor substrate 2 via the second main surface 3a of the second semiconductor substrate 3. It is. The second semiconductor substrate 3 is a multiplexer using CMOS (Complementary Metal Oxide Semiconductor) or the like. The circuit board related to the second semiconductor substrate 3 is electrically connected to each of the plurality of light receiving elements 2b of the first semiconductor substrate 2 via the second main surface 3a. The light receiving element array 21 and the plurality of height adjusting members 4 are provided between the first main surface 2 d of the first semiconductor substrate 2 and the second main surface 3 a of the second semiconductor substrate 3.

The infrared sensor 1 can further include a reinforcing member 5 as necessary. The reinforcing member 5 is uniformly filled between the first main surface 2 d of the semiconductor stack 2 a of the first semiconductor substrate 2 and the second main surface 3 a of the second semiconductor substrate 3. The material of the reinforcing member 5 is a resin, for example, an epoxy resin.

Since the plurality of height adjusting members 4 as described above are uniformly dispersed at a relatively high density (1 piece / 1 mm ² or more) as described above in the array region 21a, the first semiconductor substrate 2 and The space between the first semiconductor substrate 2 and the second semiconductor substrate 3 is uniform (regardless of the location on the first main surface 2d) from when the second semiconductor substrate 3 is bonded to when it is used as a product. And it becomes possible to keep constant. The plurality of height adjusting members 4 are uniformly distributed inside the array region 21a by the lattice-shaped grooves 2c. Since the distance between the first semiconductor substrate 2 and the second semiconductor substrate 3 is kept uniform and constant, the deflection of the first semiconductor substrate 2 is reduced, so that the light receiving surface 2e exposed to the outside of the infrared sensor 1 is reduced. Therefore, the appearance abnormality of the infrared sensor 1 can also be reduced. Furthermore, since the distance between the first semiconductor substrate 2 and the second semiconductor substrate 3 is kept uniform and constant, the bending of the first semiconductor substrate 2 is reduced, so the first due to the bending of the first semiconductor substrate 2. Since an unexpected electrical short circuit between the semiconductor substrate 2 and the second semiconductor substrate 3 can also be reduced, dot drop in the light receiving element array 21 can be reduced. Furthermore, since the height adjusting member 4 is made of quartz having a relatively high hardness, deformation due to stress received from the first semiconductor substrate 2 and the second semiconductor substrate 3 is avoided. Furthermore, since the height adjustment member 4 is higher than the light receiving element 2b in height from the first main surface 2d, the height adjustment member 4 is reliably attached to the first semiconductor substrate 2 and the second semiconductor substrate 3. Therefore, the distance between the first semiconductor substrate 2 and the second semiconductor substrate 3 can be reliably maintained constant. Furthermore, if the reinforcing member 5 is used together with the plurality of height adjusting members 4, the first semiconductor substrate 2 and the second semiconductor substrate are used from the time when the first semiconductor substrate 2 and the second semiconductor substrate 3 are joined until they are used as products. 3 can be kept more uniform (regardless of the location on the first main surface 2d) and more constant. Furthermore, the arrangement of the height adjusting member 4 can be more reliably fixed by the reinforcing member 5.

When the density of the plurality of height adjusting members 4 is less than one per unit area of 1 mm ² , the deflection of the first semiconductor substrate 2 increases with the decrease in density, and the first semiconductor substrate 2 and the second semiconductor substrate 2 The space between the semiconductor substrate 3 and the semiconductor substrate 3 is partially narrowed, which may cause an unexpected electrical short circuit between the first semiconductor substrate 2 and the second semiconductor substrate 3.

Next, a method for manufacturing the infrared sensor according to the embodiment will be described. FIG. 4 is a flowchart showing a plurality of main steps in the method for manufacturing the infrared sensor 1 according to the embodiment. 5-7 is a figure for demonstrating the manufacturing method of the infrared sensor 1 which all concern on embodiment. First, in step S1, a first semiconductor substrate 2 and a second semiconductor substrate 3 are prepared (step S1). The 1st semiconductor substrate 2 prepared in process S1 is shown to the (A) part of FIG.

The step S1 further includes a step S1a and a step S1b. Step S1a is a step of providing the protective sheet 6 on the light receiving surface 2e. The protective sheet 6 covers the light receiving surface 2e and protects the light receiving surface 2e from scratches and foreign matters.

After step S1a, step S1b is performed. Step S1b is a step of injecting the plurality of height adjusting members 4 included in the volatile solvent F1 from the injection jig 8 into the groove portion 2c through the injection port 2c1 together with the volatile solvent F1. FIG. 7 shows the state of step S1b. Part (A) of FIG. 7 shows the state of step S1b, in which the height adjusting member 4 is introduced from the injection jig 8 into the injection port 2c1 together with the volatile solvent F1. In part (B) of FIG. 7, the state of the process S1b is shown, and the height adjusting member 4 introduced into the injection port 2c1 together with the volatile solvent F1 is inserted into the array region 21a via the groove 2c together with the volatile solvent F1. It is shown that they are distributed. The volatile solvent F1 is an alcohol solvent. The groove 2c travels in the groove 2c together with the volatile solvent F1 by capillary action. By the step S1b, the plurality of height adjusting members 4 are arranged at a density of one or more per unit area of 1 mm ² in the array region 21a.

Step S2 is performed after step S1. Step S2 is a step in which the first semiconductor substrate 2 and the second semiconductor substrate 3 after Step S1b are performed are hybrid-bonded using the protective sheet 6. In step S2, as shown in FIG. 6, a bonding tool 7a is provided on the surface of the protective sheet 6, and further, a bonding tool 7b is provided on the surface of the second semiconductor substrate 3 (the surface opposite to the second main surface 3a). After that, the first semiconductor substrate 2 and the second semiconductor substrate 3 are hybrid-bonded by operating the bonding tool 7a and the bonding tool 7b. FIG. 6 shows a state in which the first semiconductor substrate 2 and the second semiconductor substrate 3 are hybrid-bonded using the bonding tool 7a and the bonding tool 7b. The volatile solvent F1 is generally removed from between the first semiconductor substrate 2 and the second semiconductor substrate 3 (particularly, the groove 2c) by volatilization or the like at the end of step S2 at the latest.

Since the volatile solvent F1 is an alcohol solvent, it can be volatilized efficiently. Further, since the groove 2c is formed by a space between the plurality of light receiving elements 2b arranged in a lattice shape, the process cost is compared with the case where the groove is actually provided on the first main surface 2d of the first semiconductor substrate 2. Is reduced.

Note that the first semiconductor substrate 20a shown in FIG. 8 may be used instead of the first semiconductor substrate 2. The first semiconductor substrate 20a is provided with a groove 2ca instead of the groove 2c. The groove 2ca is provided along the outer periphery of the first main surface 2d. In the case shown in FIG. 8, the groove 2ca is provided at two ends of the first main surface 2d. In addition, the first semiconductor substrate 20b shown in FIG. 9 may be used instead of the first semiconductor substrate 2. The first semiconductor substrate 20b includes four inlets 2c1 instead of the groove 2c. Each of the four injection ports 2c1 is arranged at four corners of the first main surface 2d.

While the principles of the invention have been illustrated and described in the preferred embodiments, it will be appreciated by those skilled in the art that the invention can be modified in arrangement and detail without departing from such principles. The present invention is not limited to the specific configuration disclosed in the present embodiment. We therefore claim all modifications and changes that come within the scope and spirit of the following claims.

DESCRIPTION OF SYMBOLS 1 ... Infrared sensor, 2, 20a, 20b ... 1st semiconductor substrate, 21 ... Light receiving element array, 21a ... Array area | region, 2a ... Semiconductor lamination, 2a1 ... Low reflection coating film, 2a2 ... Supporting base, 2a3 ... N-type layer, 2b ... light receiving element, 2c, 2ca ... groove, 2c1 ... injection port, 2d ... first main surface, 2e ... light receiving surface, 3 ... second semiconductor substrate, 3a ... second main surface, 4 ... height adjusting member, 5 ... reinforcing member, 6 ... protective sheet, 7a, 7b ... bonding tool, F1 ... volatile solvent, R1 ... region.

Claims (12)

A first semiconductor substrate, a second semiconductor substrate, and a plurality of height adjustment members,
The first semiconductor substrate and the second semiconductor substrate are hybrid-bonded,
The first semiconductor substrate includes a light receiving element array;
The light receiving element array is provided on a first main surface of the first semiconductor substrate, and includes a plurality of light receiving elements,
The plurality of light receiving elements are arranged in a lattice shape on the first main surface,
The plurality of height adjusting members are arranged at a density of one or more per unit area of 1 mm ^{2 in} the array region in which the light receiving element array is provided in the first main surface.
The second semiconductor substrate is a circuit board for reading an electrical optical signal output from each of the plurality of light receiving elements through the second main surface of the second semiconductor substrate, and the second main surface Are electrically connected to each of the plurality of light receiving elements via
The light receiving element array and the plurality of height adjusting members are provided between the first main surface and the second main surface.
An infrared sensor characterized by that. The first semiconductor substrate or the second semiconductor substrate includes a groove,
The groove is formed on the first main surface when the groove is provided on the first semiconductor substrate, or on the second main when the groove is provided on the second semiconductor substrate. Is provided on the surface, has a lattice shape according to the lattice arrangement of the plurality of light receiving elements, and has an injection port,
The inlet is an opening for introducing the height adjusting member into the groove,
The plurality of height adjusting members are distributed in the array region along the groove portion at the density in the array region.
The infrared sensor according to claim 1. In the state where the height adjusting member is disposed in the groove portion provided with the first semiconductor substrate, the height from the first main surface is higher in the height adjusting member than in the light receiving element. high,
The infrared sensor according to claim 2. The shape of the height adjusting member is a sphere,
The infrared sensor as described in any one of Claims 1-3 characterized by the above-mentioned. The material of the height adjusting member is quartz.
The infrared sensor as described in any one of Claims 1-4 characterized by the above-mentioned. A reinforcing member,
The reinforcing member is filled between the first main surface and the second main surface,
The material of the reinforcing member is resin,
The infrared sensor according to any one of claims 1 to 5, wherein: Preparing a first semiconductor substrate and a second semiconductor substrate;
Hybrid bonding the first semiconductor substrate and the second semiconductor substrate;
With
The first semiconductor substrate includes a light receiving element array;
The light receiving element array is provided on a first main surface of the first semiconductor substrate, and includes a plurality of light receiving elements,
The plurality of light receiving elements are arranged in a lattice shape on the first main surface,
The second semiconductor substrate is a circuit board for reading an electrical optical signal output from each of the plurality of light receiving elements via a second main surface of the second semiconductor substrate;
The first semiconductor substrate or the second semiconductor substrate includes a groove,
The groove is formed on the first main surface when the groove is provided on the first semiconductor substrate, or on the second main when the groove is provided on the second semiconductor substrate. Is provided on the surface, has a lattice shape according to the lattice arrangement of the plurality of light receiving elements, and has an injection port,
The injection port is an opening for introducing a height adjusting member disposed between the first semiconductor substrate and the second semiconductor substrate into the groove portion,
The step of preparing the first semiconductor substrate and the second semiconductor substrate includes injecting the plurality of height adjusting members contained in a volatile solvent into the groove portion together with the volatile solvent through the injection port. And a step of dispersing along the groove portion in an array region of the first main surface where the light receiving element array is provided,
In the step of injecting and dispersing the plurality of height adjusting members, the plurality of height adjusting members are arranged at a density of one or more per unit area of 1 mm ^{2 in} the array region.
An infrared sensor manufacturing method characterized by the above. The first semiconductor substrate includes a light receiving surface;
The light receiving surface is on the opposite side of the first main surface;
The step of preparing the first semiconductor substrate and the second semiconductor substrate includes a step of providing a protective sheet covering the light receiving surface on the light receiving surface,
The step of providing the protective sheet is performed before the step of injecting and dispersing the plurality of height adjusting members,
In the step of hybrid-bonding the first semiconductor substrate and the second semiconductor substrate, using the protective sheet, the first semiconductor substrate and the second semiconductor substrate are hybrid-bonded.
The manufacturing method of the infrared sensor of Claim 7 characterized by the above-mentioned. The groove portion is formed by a space between the plurality of light receiving elements arranged in a lattice pattern.
The method for manufacturing an infrared sensor according to claim 7 or 8, wherein: The material of the height adjusting member is quartz.
The method for manufacturing an infrared sensor according to any one of claims 7 to 9, wherein: The volatile solvent is an alcohol solvent,
The manufacturing method of the infrared sensor as described in any one of Claims 7-10 characterized by the above-mentioned. In the state where the height adjusting member is disposed in the groove portion provided with the first semiconductor substrate, the height from the first main surface is higher in the height adjusting member than in the light receiving element. high,
The manufacturing method of the infrared sensor as described in any one of Claims 7-11 characterized by the above-mentioned.

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