JP3751382B2 - Semiconductor device and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a semiconductor device, and more particularly to a semiconductor device used for infrared detection in an infrared imaging device or the like and a method for manufacturing the same.
[0002]
[Prior art]
Conventionally, as a compound semiconductor crystal material of an infrared photoelectric conversion light receiving element having a wavelength of 2 μm or more, Hg having a narrow energy gap is used. _1-x Cd _x Te (mercury cadmium tellurium) crystals are used.
Hg _1-x Cd _x Since the Te crystal can be grown on the CdZnTe substrate by a liquid phase epitaxy (LPE) method, an infrared photodiode is formed using this crystal.
[0003]
On the other hand, when an array is constituted by such infrared photodiodes, it is preferable to reduce the number of lead-out lines as much as possible. Therefore, a silicon substrate on which a signal processing circuit is formed and a substrate on which an infrared photodiode array is formed. Are bonded together via a metal material (In bump) such as In (indium) to produce a hybrid infrared detector (IRFPA: InfraRed Focal Plane Arrays).
[0004]
An example of the structure is shown in FIG. FIG. 10A is a perspective view schematically showing a conventional semiconductor device, and FIG. 10B is a sectional view thereof.
The CdZnTe substrate 40 includes p-type Hg _1-x Cd _x Te crystal layer 42 is epitaxially grown. p-type Hg _1-x Cd _x In a predetermined region of the Te crystal layer 42, n-type Hg _1-x Cd _x A Te crystal layer 44 is formed. Thus, p-type Hg _1-x Cd _x Te crystal layer 42 and n-type Hg _1-x Cd _x A pn junction type infrared photodiode array constituted by the Te crystal layer 44 is formed. Where p-type Hg _1-x Cd _x The Te crystal layer 42 is formed of n-type Hg by using, for example, mercury vacancies. _1-x Cd _x The Te crystal layer 44 is obtained, for example, by implanting boron (B) ions.
[0005]
The n-type region (n-type Hg) of the photodiode formed in this way _1-x Cd _x The Te crystal layer 44) is coupled via an In bump 46 to a silicon signal processing circuit substrate 48 on which a signal processing circuit is formed. The p-type region of the photodiode array is common in the array and is coupled via an In bump (not shown) similar to the In bump 46 used in the n-type region.
[0006]
In this way, a hybrid type IRFPA was configured.
Further, the conventional semiconductor device shown in FIG. 11 has an Hg film thickness of about 20 μm. _1-x Cd _x A Te crystal layer 54 is formed on the silicon substrate 50 via a CdTe buffer layer 52 having a thickness of about 10 μm. _1-x Cd _x A photodiode array is formed on the Te crystal layer 54.
[0007]
By configuring the semiconductor device in this manner, the difference in thermal expansion coefficient between the substrate on which the photodiode array is formed (silicon substrate 50) and the substrate on which the signal processing circuit is formed (silicon signal processing circuit substrate 48) is reduced. There has been an attempt to construct a large-scale semiconductor device.
[0008]
[Problems to be solved by the invention]
However, in the conventional semiconductor device shown in FIG. 10, when the temperature rise and fall is repeated several hundred times between 77 to 80K, which is the operating temperature of the infrared detecting device, and 280 to 310K, which is the storage temperature of the infrared detecting device (hereinafter referred to as the temperature). Hg on which an infrared photodiode array is formed _1-x Cd _x The Te crystal layer 42 and the signal processing circuit formed on the silicon signal processing circuit substrate 48 may be peeled off from the In bump 46 portion.
[0009]
Specifically, when a two-dimensional array of 256 × 256 pixels is formed with a size of one infrared photodiode of 25 μm square, the size becomes 6.4 mm × 6.4 mm. When a semiconductor device of a larger size is configured, Hg is generated by thermal cycling. _1-x Cd _x Peeling may occur between the Te crystal layer 42 and the silicon signal processing circuit board 48.
[0010]
Further, in the conventional semiconductor device shown in FIG. 11, Hg formed on the silicon substrate 50 by thermal cycling. _1-x Cd _x The Te crystal layer 54 may break, and the size equivalent to that of the conventional semiconductor device shown in FIG.
The object of the present invention is to achieve Hg even after thermal cycling. _1-x Cd _x It is an object of the present invention to provide a semiconductor device having a photodiode array with a large area and a high number of pixels, and a manufacturing method thereof, in which a photodiode array made of Te crystal does not peel off from a signal processing circuit formed on a silicon substrate.
[0011]
[Means for Solving the Problems]
The object is to provide a semiconductor device having a substrate on which a signal processing element is formed and a plurality of photodetecting elements connected to the signal processing element. The photodetecting element is made of a material having a coefficient of thermal expansion different from that of the substrate, A plurality of electrode members that are provided between the substrate and the light detection element and that couple the substrate and the light detection element; and a conductive material that is provided in a gap between the plurality of light detection elements and is plastically deformed. This is achieved by a semiconductor device having a coupling member that couples the plurality of light detection elements to each other. By configuring the semiconductor device in this manner, a volume change due to a difference in thermal expansion coefficient between the substrate and the light detection element due to thermal cycling can be absorbed by the coupling member. Thereby, even when IRFPA having a large area and a large number of pixels is formed, peeling of the electrode member can be prevented.
[0012]
In the above semiconductor device, on the surface of the photodetecting element coupled to the coupling member, Conductive adhesion film It is desirable to have further. If the semiconductor device is configured in this manner, the coupling between the photodetecting elements can be further increased, so that deterioration of the semiconductor device due to thermal cycling can be reduced.
In the semiconductor device described above, it is preferable that the coupling member is a granular member inserted in a gap between the light detection elements.
[0013]
In the semiconductor device, it is preferable that the coupling member further includes a conductive member embedded in a gap between the light detection elements. If the semiconductor device is configured in this manner, the connection resistance between the photodetecting elements can be reduced and the coupling force can be increased.
In the semiconductor device described above, it is preferable that the coupling member is a structure provided so as to protrude on the substrate, and is fitted to at least a part of a gap between the light detection elements.
[0014]
In the semiconductor device described above, the electrode member is preferably made of a conductive material that is plastically deformed. If the semiconductor device is configured in this manner, the stress acting between the substrate and the photodetecting element can be further reduced. Thereby, even when IRFPA having a large area and a large number of pixels is formed, peeling of the electrode member can be prevented.
[0015]
According to another aspect of the present invention, there is provided a semiconductor layer forming step of forming a semiconductor layer having a plurality of light detection elements on a first substrate, and a groove reaching the first substrate is formed in the semiconductor layer. An element dividing step for dividing the layer into predetermined regions, and a first coupling in which a coupling member made of a plastically deformable conductive material is inserted into the groove, and the divided semiconductor layers are coupled to each other by the coupling member Process, The semiconductor layer is made of a material having a different thermal expansion coefficient. A second coupling step of electrically coupling the second substrate on which the signal processing element is formed and the light detection element formed on the first substrate through an electrode member; And a substrate removing step for removing the substrate and leaving the semiconductor layer bonded by the bonding member. By manufacturing the semiconductor device in this way, it is possible to form on the substrate the photodetecting elements that are coupled to each other by the coupling member that is plastically deformed. Thereby, the volume change by the difference in the thermal expansion coefficient of the board | substrate and semiconductor layer by a thermal cycle can be absorbed. Further, it is possible to form an IRFPA having a large area and a high number of pixels in which the electrode member is not peeled off even by a thermal cycle.
[0016]
Further, the object is to form a semiconductor layer forming step of forming a semiconductor layer having a plurality of photodetecting elements on the first substrate, and to form a groove reaching the first substrate in the semiconductor layer. An element dividing step of dividing the layer into predetermined regions; The semiconductor layer is made of a material having a different thermal expansion coefficient. A coupling member forming step of forming a projecting coupling member made of a conductive material that is plastically deformed and fitted into at least a part of the groove on the second substrate on which the signal processing element is formed; And the photodetecting element formed on the first substrate are electrically coupled by an electrode member, and the divided semiconductor layers are coupled to each other by the coupling member inserted in the groove. The present invention is also achieved by a method for manufacturing a semiconductor device, comprising: a bonding step; and a substrate removing step of removing the first substrate and leaving the semiconductor layer bonded by the bonding member. By manufacturing the semiconductor device in this way, it is possible to form the light detecting elements coupled to each other by the plastically deforming coupling member on the substrate. Thereby, the volume change by the difference in the thermal expansion coefficient of the board | substrate and semiconductor layer by a thermal cycle can be absorbed. Further, it is possible to form an IRFPA having a large area and a high number of pixels in which the electrode member is not peeled off even by a thermal cycle.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
[First Embodiment]
The semiconductor device and the manufacturing method thereof according to the first embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a graph showing the temperature change of the linear expansion coefficient in HgCdTe and silicon, FIG. 2 is a schematic sectional view showing the structure of the semiconductor device according to the present embodiment, and FIGS. 3 to 5 show the method for manufacturing the semiconductor device according to the present embodiment. It is process sectional drawing shown.
[0018]
First, in a conventional semiconductor device, a silicon substrate and Hg _1-x Cd _x Consider the mechanism by which peeling occurs between Te crystals.
As shown in FIG. 1, the linear expansion coefficient of HgCdTe is always about twice as large as that of silicon in the temperature range of FIG. Therefore, Hg formed on the silicon substrate by thermal cycling _1-x Cd _x The Te crystal layer peels off or cracks because of the silicon substrate and Hg. _1-x Cd _x It is considered that a phenomenon occurs in which the In bump is deformed and finally peeled when the Te crystal layer undergoes different volume changes according to the respective physical properties due to thermal cycles.
[0019]
The two-dimensional array that can be realized by the conventional technique has a pixel size of 50 μm square, the number of pixels is 64 × 64, and the size is about 3.2 mm × 3.2 mm.
Therefore, when IRFPA of this size is produced, the linear expansion coefficient of silicon and HgCdTe is 5.4 × 10 4 at 300 K to 80 K in a diagonal length of 4.5 mm. ^-Four (Corresponding to an integral value of 80 to 300 K of the linear expansion coefficient difference between silicon and HgCdTe in the graph of the linear expansion diameter in FIG. 1) and the silicon substrate and Hg. _1-x Cd _x This is the difference in length generated between the Te crystal layer. That is, the silicon substrate and Hg _1-x Cd _x A difference in length of about 2.4 μm occurs between the Te crystal layer and the Te crystal layer due to thermal expansion.
[0020]
Since In is a material that has a soft Brinell hardness of 1.2 and causes plastic deformation with a small force, a deformation amount of about 2.4 μm can be relaxed by plastic deformation of In bumps.
However, when an IRFPA having a larger size, for example, a pixel size of 25 μm square and a number of pixels of 256 × 256 is manufactured, the diagonal length becomes 9.1 mm, and when the linear expansion coefficient is multiplied, the length becomes 4.9 μm. There will be a difference. For this reason, the plastic deformation of the In bump alone is not sufficient to absorb the deformation amount. _1-x Cd _x It is thought that peeling occurred between Te crystals.
[0021]
Therefore, to manufacture IRFPA with a large area and a large number of pixels, a silicon substrate and Hg _1-x Cd _x It is important how to absorb the deformation due to the difference in thermal expansion coefficient of the Te crystal layer.
Next, the structure of the semiconductor device according to the present embodiment will be explained with reference to FIG.
From the above consideration results, the semiconductor device according to the present embodiment has a silicon substrate and Hg. _1-x Cd _x The feature is that the photodiodes constituting the array are formed in the element regions divided into islands in order to reduce the deformation amount due to the thermal expansion difference of the Te crystal.
[0022]
That is, the element region 18 is coupled by In bumps 26 and 32 on the silicon signal processing circuit substrate 30 on which the signal processing circuit (not shown) is formed. The In bump 26 is connected to the n-type region 14 of the photodiode, and the n-type region 14 and the signal processing circuit are electrically connected via the In bumps 26 and 32.
[0023]
The plurality of element regions 18 formed in this way are coupled to each other by an In sphere 20 and an In film 22 and are also electrically connected at the same time. The region thus coupled becomes a common p-type region of the photodiode.
As described above, in the semiconductor device according to the present embodiment, the element region 18 in which the photodiode is formed is divided and coupled with In which is easily plastically deformed, and the silicon signal processing circuit board 30 and the element region 18 are plastically deformed. Since it is electrically coupled by easy In, silicon signal processing circuit board 30 and Hg _1-x Cd _x The difference in volume change due to the difference in thermal expansion coefficient from the Te crystal layer 12 can be absorbed by these binders.
[0024]
Next, the method for fabricating the semiconductor device according to the present embodiment will be explained with reference to FIGS.
First, on the CdZnTe substrate 10, Hg having a film thickness of about 15 μm is formed by the LPE method, for example. _1-x Cd _x A Te crystal layer 12 is grown (FIG. 3A). Where Hg _1-x Cd _x The Cd composition x of the Te crystal layer 12 is appropriately adjusted according to the infrared wavelength for measurement purposes. For example, in order to adjust the cutoff wavelength to 10 μm, the Cd composition x is set to 0.225. Hg _1-x Cd _x The electric conductivity type of the Te crystal layer 12 is matched with the target device structure of the photodiode. For example, the p-type carrier concentration due to Hg vacancies is 2 × 10 ¹⁶ cm ^-3 And
[0025]
Then Hg _1-x Cd _x Boron (B: boron) as a donor impurity is ion-implanted into a predetermined region of the Te crystal layer 12 to form an n-type region 14 (FIG. 3B). Thus, the pn junction photodiode array is converted to Hg. _1-x Cd _x It is formed in the Te crystal layer 12.
Next, Hg _1-x Cd _x The Te crystal layer 12 is etched to form a wedge-shaped groove 16 reaching the CdZnTe substrate 10, and the pn junction photodiode array is divided into a plurality of element regions 18 (FIG. 3C). For example, when one photodiode is arranged at an interval of 40 μm, a trench 16 having an upper width of about 15 μm and a lower width of about 5 μm is formed, and a trapezoidal element having an upper surface of about 25 μm square and a lower surface of about 40 μm square. Etching is performed so that each photodiode is located in the region 18. Hg _1-x Cd _x For the etching of the Te crystal layer 12, for example, wet etching using bromomethanol can be used.
[0026]
Thereafter, an In sphere 20 having a diameter of about 10 μm is formed by Hg. _1-x Cd _x It sprays on the surface of the Te crystal layer 12 and is inserted into the groove 16.
Next, the In film 22 is embedded in the groove 16 by using, for example, a lift-off method (FIG. 3D). For example, after forming the resist film 24 only on the upper surface of the element region 18 (FIG. 4A), the In film 22 is deposited on the entire surface by vapor deposition or sputtering (FIG. 4B), and the resist film 24 is formed. By removing only the In film 22 on the resist film 24 at the same time, the In film 22 can be left only in the groove 16. The mask used when forming the groove 16 can be applied to the resist film 24 as it is.
[0027]
The In sphere 20 and the In film 22 formed in this manner have a function of mutually coupling the element regions 18 divided by the grooves 16 and electrically connecting the p-type regions divided by the grooves 16.
Subsequently, an In bump 26 made of a conductive material that causes plastic deformation, for example, In, is formed on the n-type region 14 of the element region 18. Thus, the CdZnTe substrate 10 having the infrared photodiode array is formed (FIG. 5A).
[0028]
On the other hand, a signal processing circuit (not shown) is formed on a separately prepared silicon signal processing circuit substrate 30 by an ordinary semiconductor device manufacturing method. Then, an In bump 32 made of a conductive material that causes plastic deformation, for example, In, is formed on the silicon signal processing circuit substrate 30 on which the signal processing circuit is formed. The In bump 32 is connected to the input terminal of the signal processing circuit. Thus, the silicon signal processing circuit board 30 having the signal processing circuit in which the In bump 32 is connected to the input terminal is formed (FIG. 5B).
[0029]
In this way, after preparing the CdZnTe substrate 10 on which the infrared photodiode array is formed and the silicon signal processing circuit substrate 30 on which the signal processing circuit is formed, these substrates are connected to each other (FIG. 5C). . The substrates are connected by electrically and mechanically coupling the In bumps 26 and the In bumps 32 by overlapping and pressing.
[0030]
Next, the CdZnTe substrate 10 that supports the infrared photodiode array is selectively removed (FIG. 5D). For removing the CdZnTe substrate 10, for example, a chemical mechanical polishing (CMP) method, wet etching with chemicals, dry etching with argon ions, or the like can be used.
[0031]
By manufacturing the semiconductor device in this way, the element regions 18 in which the photodiodes are formed are coupled to each other by an In sphere 20 and an In film 22 that are susceptible to plastic deformation, and a silicon signal processing circuit board. 30 is coupled by In bumps 26 and 32 which are likely to cause plastic deformation.
By dividing the element region 18 in this way, deformation due to thermal expansion of the element region 18 occurs only for each element region 18. When the size of the element region 18 is a trapezoidal shape having an upper surface of about 25 μm square, a lower surface of about 40 μm square, and a thickness of 15 μm, the deformation amount of each element region 18 is 56.6 μm, which is the diagonal of the element region 18. Furthermore, the linear expansion coefficient 5.4 × 10 5 of silicon of 300K to 80K and HgCdTe ^-Four The value multiplied by, that is, about 0.03 μm. This amount of deformation can be sufficiently absorbed by plastic deformation of the In film 22 that couples the element regions 18 to each other, so that deformation due to thermal expansion when a thermal cycle is applied can be absorbed.
[0032]
As described above, according to the present embodiment, the element region 18 in which the light detection element is formed is divided and bonded together by materials that are easily plastically deformed, and the silicon signal processing circuit board 30 and the element region 18 are plastically deformed. Since it is electrically coupled by an easy material, the silicon signal processing circuit board 30 and Hg by thermal cycling _1-x Cd _x Volume changes due to the difference in thermal expansion coefficient from the Te crystal layer 12 can be absorbed by these binders.
[0033]
As a result, even when IRFPA with a large area and a large number of pixels is formed, Hg due to thermal cycling _1-x Cd _x Peeling between the Te crystal layer 12 and the silicon signal processing circuit board 30 can be prevented.
In the above embodiment, the In film 22 is embedded after the In sphere 20 is inserted into the groove 16. The reason why the In sphere 20 is inserted in this way is to make the bonding between the element regions 18 more reliable because it is difficult to form the In film 22 having a good film quality by vapor deposition or the like. Therefore, the insertion of the In sphere 20 is not an essential means for achieving the object of the present invention, and a semiconductor device can be manufactured without providing the In sphere 20. The member to be inserted is not limited to a spherical body, and may be a plate-like body, a granular body, or other shapes.
[0034]
Further, as shown in FIG. 6, before the In sphere 20 is inserted, a material that is easy to plastically embed in the groove 16 and a material having good adhesion, for example, an Au (gold) film 28 is formed on the sidewall of the groove 16. (FIG. 6A), the In film 22 may be connected to the element region 18 through the Au film 28 (FIG. 6B). In this way, the element regions 18 can be more reliably coupled.
[0035]
In the above embodiment, one photodiode is provided in each of the element regions 18 divided by the grooves 16, but two or more photodetecting elements can be formed in one element region. It is desirable that the number of light detection elements provided in one element region is appropriately adjusted in consideration of the size, integration degree, thermal expansion coefficient, and the like of one element. In the above embodiment, In is used as a material that easily undergoes plastic deformation, but other conductive materials may be used. For example, an alloy containing In, Sn (tin), an alloy containing Sn, or an insulating polymer material (eg, epoxy resin) mixed with a conductive powder material (eg, Ag (silver)) can be used.
[0036]
In the above embodiment, Hg _1-x Cd _x Although the photodiode is formed using the Te crystal layer 12, the light detection element may be formed using another crystal layer. For example, Hg _1-x Zn _x Te crystal layer, Hg _1-xy Cd _x Zn _y A Te crystal layer or the like can be applied.
Moreover, in the said embodiment, although the crystal layer which forms a photon detection element was formed on the CdZnTe board | substrate 10, you may use another board | substrate. For example, CdTe, CdTe _1-x Se _x II-VI semiconductor substrates such as GaAs, III-V semiconductor substrates such as GaAs and InP, IV group semiconductor substrates such as Si, and insulating substrates such as sapphire can be applied.
[0037]
In the above embodiment, the CdZnTe substrate 10 is removed. However, when a substrate having a thermal expansion coefficient substantially equal to that of the substrate on which the signal processing circuit is formed is not necessarily removed. For example, if a silicon substrate is used instead of the CdZnTe substrate 10, the semiconductor device can be configured without removing the silicon substrate.
[Second Embodiment]
A semiconductor device and a manufacturing method thereof according to the second embodiment of the present invention will be described with reference to FIGS. The same components as those of the semiconductor device and the manufacturing method thereof according to the first embodiment are denoted by the same reference numerals, and description thereof is omitted or simplified.
[0038]
FIG. 7 is a schematic sectional view showing the structure of the semiconductor device according to the present embodiment. FIG. 8 is a process sectional view showing the method for manufacturing the semiconductor device according to the present embodiment.
In the first embodiment, the element regions 18 are coupled to each other by embedding the In film 22 in the groove 16 that divides the element region 18, but may be realized by other methods.
[0039]
That is, the semiconductor device according to the present embodiment further includes a protruding lateral coupling bump 34 made of In which is easily deformed in composition and fitted into the groove 16 dividing the element region 18 on the silicon signal processing circuit board 30. The lateral coupling bumps 34 serve to couple the element regions 18 to each other and to electrically connect them.
Also by configuring the semiconductor device in this manner, the element region 18 in which the photodiode is formed is coupled to each other by In which is easily compositionally deformed, and the silicon signal processing circuit substrate 30 and the element region 18 are easily plastically deformed. It can be electrically coupled by In.
[0040]
Next, the method for fabricating the semiconductor device according to the present embodiment will be explained with reference to FIGS.
First, for example, in the same manner as the semiconductor device manufacturing method according to the first embodiment shown in FIGS. _1-x Cd _x A CdZnTe substrate 10 on which a photodiode array is formed is formed on the Te crystal layer 12.
Next, an In bump 26 is formed on the n-type region 14 without embedding the In sphere 20 and the In film 22 in the groove 16 (FIG. 8A).
[0041]
On the other hand, a signal processing circuit is formed on a separately prepared silicon signal processing circuit substrate 30 by an ordinary semiconductor device manufacturing method.
Subsequently, an In bump 32 made of In and connected to an input terminal of the signal processing circuit is formed on the silicon signal processing circuit substrate 30. At the same time, a lateral coupling bump 34 made of In and higher than the In bump 32 is formed on the silicon signal processing circuit board 30. When the In bump 32 and the In bump 26 are bonded to each other, the laterally bonded bump 34 is Hg. _1-x Cd _x It arrange | positions so that it may insert in the groove | channel 16 formed in the Te crystal layer 12 (FIG.8 (b)).
[0042]
Thereafter, the silicon signal processing circuit substrate 30 and the CdZnTe substrate 10 face each other and are coupled to each other by In bumps 26 and 32. At this time, the lateral coupling bumps 34 are inserted into the grooves 16, and the element regions 18 are coupled to each other by the lateral coupling bumps 34 (FIG. 8C).
Next, the CdZnTe substrate 10 is selectively removed (FIG. 8D).
[0043]
By manufacturing the semiconductor device in this manner, the element regions 18 in which the photodiodes are formed are coupled to each other by the lateral coupling bumps 34 that are liable to be plastically deformed. Bonded by In bumps 26 and 32 that are liable to cause plastic deformation. Thereby, the thermal expansion at the time of applying a thermal cycle can fully be absorbed by the plastic deformation of the binder.
[0044]
As described above, according to the present embodiment, the element region 18 in which the light detection element is formed is divided and bonded together by materials that are easily plastically deformed, and the silicon signal processing circuit board 30 and the element region 18 are plastically deformed. Since it is electrically coupled by an easy material, the silicon signal processing circuit board 30 and Hg by thermal cycling _1-x Cd _x Volume changes due to the difference in thermal expansion coefficient from the Te crystal layer 12 can be absorbed by these binders.
[0045]
As a result, even when IRFPA having a large area and a large number of pixels is formed, Hg _1-x Cd _x Peeling between the Te crystal layer 12 and the silicon signal processing circuit board 30 can be prevented.
It is desirable that the lateral coupling bumps 34 have a structure that does not completely fill the grooves 16. This is because by leaving a space in a part of the groove 16, it can function as a space that absorbs deformation when the laterally coupled bump 34 undergoes plastic deformation.
[0046]
Therefore, for example, the structure shown in FIG. 9 can be applied as the lateral coupling bump 34. 9A shows a structure in the case where the lateral coupling bumps 34 are located at the intersections of the grooves 16, and FIG. 9B shows a structure in a case where the lateral coupling bumps 34 are located on the sides of the grooves 16.
If the lateral coupling bumps 34a shown in FIG. 9A are used, the deformation is absorbed in the side space of the groove 16, and if the lateral coupling bumps 34b shown in FIG. The deformation can be absorbed.
[0047]
【The invention's effect】
As described above, according to the present invention, in a semiconductor device having a substrate on which a signal processing element is formed and a plurality of photodetecting elements connected to the signal processing element, The light detection element is made of a material having a different thermal expansion coefficient from that of the substrate. A plurality of electrode members that are provided between the substrate and the light detection element, are provided in gaps between the plurality of light detection elements and are plastically deformed, and are formed of a plurality of light members. Since the coupling member that couples the sensing elements to each other is provided, the coupling member can absorb the volume change due to the difference in the thermal expansion coefficient between the substrate and the light sensing element due to the thermal cycle. Thereby, even when IRFPA having a large area and a large number of pixels is formed, peeling of the electrode member can be prevented.
[0048]
Further, in the above semiconductor device, on the surface of the photodetecting element coupled to the coupling member, Conductive adhesion film Since the coupling between the photodetecting elements can be further increased, deterioration of the semiconductor device due to the thermal cycle can be reduced.
In the above semiconductor device, a granular member inserted in the gap between the light detection elements can be applied as the coupling member.
[0049]
In the above semiconductor device, if the coupling member is further provided with a conductive member embedded in the gap between the light detection elements, the connection resistance between the light detection elements can be reduced and the coupling force can be increased. .
In the semiconductor device described above, a structure that protrudes from the substrate and fits into at least a part of the gap between the light detection elements can be applied to the coupling member.
[0050]
In the semiconductor device described above, if the electrode member is made of a conductive material that is plastically deformed, the stress acting between the substrate and the light detection element can be further reduced. Thereby, even when IRFPA having a large area and a large number of pixels is formed, peeling of the electrode member can be prevented.
In addition, a semiconductor layer forming step of forming a semiconductor layer having a plurality of photodetector elements on the first substrate, and a groove reaching the first substrate is formed in the semiconductor layer, and the semiconductor layer is divided into predetermined regions An element dividing step, and a first coupling step in which a coupling member made of a plastically deformable conductive material is inserted into the groove, and the divided semiconductor layers are coupled to each other by the coupling member; The semiconductor layer is made of a material with a different coefficient of thermal expansion. A second coupling step of electrically coupling the second substrate on which the signal processing element is formed and the light detection element formed on the first substrate through the electrode member; and By manufacturing the semiconductor device by the substrate removing step of removing and remaining the semiconductor layer bonded by the bonding member, it is possible to form the light detecting elements bonded to each other by the plastically deformed bonding member on the substrate. Thereby, the volume change by the difference in the thermal expansion coefficient of the board | substrate and semiconductor layer by a thermal cycle can be absorbed. Further, it is possible to form an IRFPA having a large area and a high number of pixels in which the electrode member is not peeled off even by a thermal cycle.
[0051]
In addition, a semiconductor layer forming step of forming a semiconductor layer having a plurality of light detection elements on the first substrate, and a groove reaching the first substrate is formed in the semiconductor layer, and the semiconductor layer is divided into predetermined regions An element splitting process; The semiconductor layer is made of a material with a different coefficient of thermal expansion. A coupling member forming step of forming a projecting coupling member made of a conductive material that is plastically deformed and fitted into at least a part of the groove on the second substrate on which the signal processing element is formed; And a photodetecting element formed on the first substrate are electrically coupled by an electrode member, and a coupling step of coupling the divided semiconductor layers to each other by a coupling member inserted in the groove; Forming a photodetecting element coupled to each other by a plastically deformable coupling member on the substrate also by removing the substrate and manufacturing the semiconductor device by a substrate removal process in which the semiconductor layer coupled by the coupling member remains. Can do. Thereby, the volume change by the difference in the thermal expansion coefficient of the board | substrate and semiconductor layer by a thermal cycle can be absorbed. Further, it is possible to form an IRFPA having a large area and a high number of pixels in which the electrode member is not peeled off even by a thermal cycle.
[Brief description of the drawings]
FIG. 1 is a graph showing a temperature change of a linear expansion coefficient in HgCdTe and silicon.
FIG. 2 is a schematic cross-sectional view showing the structure of the semiconductor device according to the first embodiment of the present invention.
FIG. 3 is a process cross-sectional view (part 1) illustrating the method for manufacturing the semiconductor device according to the first embodiment of the invention;
FIG. 4 is a process cross-sectional view (part 2) illustrating the method for manufacturing the semiconductor device according to the first embodiment of the invention;
FIG. 5 is a process cross-sectional view (part 3) illustrating the method for manufacturing the semiconductor device according to the first embodiment of the invention;
6 is a schematic cross-sectional view showing a structure of a semiconductor device and a manufacturing method according to a modification of the first embodiment. FIG.
FIG. 7 is a schematic cross-sectional view showing the structure of a semiconductor device according to a second embodiment of the present invention.
FIG. 8 is a process sectional view showing a method for producing a semiconductor device according to a second embodiment of the invention.
FIG. 9 is a perspective view showing a structure of a lateral coupling bump in the semiconductor device according to the second embodiment.
10A and 10B are a schematic view and a cross-sectional view showing a structure of a conventional semiconductor device.
FIG. 11 is a schematic cross-sectional view showing the structure of a conventional semiconductor device.
[Explanation of symbols]
10 ... CdZnTe substrate
12 ... Hg _1-x Cd _x Te crystal layer
14 ... n-type region
16 ... groove
18 ... Element region
20 ... In sphere
22 ... In film
24. Resist film
26 ... In bump
28 ... Au film
30 ... Silicon signal processing circuit board
32 ... In bump
34 ... Horizontal coupling bump
40 ... CdZnTe substrate
42 ... Hg _1-x Cd _x Te crystal layer
44 ... n-type region
46 ... In bump
48 ... Silicon signal processing circuit board
50 ... Silicon substrate
52 ... CdTe buffer layer
54 ... Hg _1-x Cd _x Te crystal layer

Claims (8)

In a semiconductor device having a substrate on which a signal processing element is formed and a plurality of light detection elements connected to the signal processing element,
The photodetecting element is made of a material having a coefficient of thermal expansion different from that of the substrate,
A plurality of electrode members provided between the substrate and the photodetecting element, and coupling the substrate and the photodetecting element;
A semiconductor device comprising: a coupling member that is provided in a gap between the plurality of photodetecting elements, is made of a conductive material that is plastically deformed, and that couples the photodetecting elements to each other. The semiconductor device according to claim 1,
A semiconductor device, further comprising a conductive adhesion film on a surface of the photodetecting element coupled to the coupling member. The semiconductor device according to claim 1 or 2,
The coupling device is a granular member inserted in a gap between the light detection elements. The semiconductor device according to claim 3.
The coupling device further includes a conductive member embedded in a gap between the light detection elements. The semiconductor device according to claim 1 or 2,
The semiconductor device according to claim 1, wherein the coupling member is a structure provided so as to protrude on the substrate, and is fitted to at least a part of a gap between the light detection elements. The semiconductor device according to claim 1,
The said electrode member is comprised with the electroconductive material which deforms plastically. The semiconductor device characterized by the above-mentioned. A semiconductor layer forming step of forming a semiconductor layer having a plurality of photodetecting elements on the first substrate;
Forming a groove reaching the first substrate in the semiconductor layer, and dividing the semiconductor layer into predetermined regions;
A first coupling step in which a coupling member made of a conductive material that is plastically deformed is inserted into the groove, and the divided semiconductor layers are coupled to each other by the coupling member;
The second substrate having a signal processing element formed of a material having a thermal expansion coefficient different from that of the semiconductor layer is electrically connected to the photodetecting element formed on the first substrate through an electrode member. A second bonding step for bonding to
And a substrate removing step of removing the first substrate and leaving the semiconductor layer coupled by the coupling member. A semiconductor layer forming step of forming a semiconductor layer having a plurality of photodetecting elements on the first substrate;
Forming a groove reaching the first substrate in the semiconductor layer, and dividing the semiconductor layer into predetermined regions;
The semiconductor layer is made of a material having a different thermal expansion coefficient and formed on a second substrate on which a signal processing element is formed. A coupling member forming step of forming a member;
The second substrate and the photodetecting element formed on the first substrate are electrically coupled by an electrode member, and the divided semiconductor layer is coupled by the coupling member inserted into the groove. A bonding step for bonding to each other;
And a substrate removing step of removing the first substrate and leaving the semiconductor layer coupled by the coupling member.

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