JP6419851B2 - Interposer substrate laminate and manufacturing method thereof - Google Patents

Description

  The present invention relates to a substrate laminate including a second substrate on a first substrate, and an interposer substrate laminate including another substrate via a metal layer on an interposer substrate including a plurality of through holes. And a manufacturing method thereof.

  In a semiconductor device, for example, a semiconductor chip such as an IC chip or an LSI chip is mounted on a wiring board (also called a mounting board) such as a multilayer circuit board. Examples of the mounting technique for electrically connecting the wiring board and the semiconductor chip include a wire bonding (WB) method and a flip chip (FC) method.

  The WB method is a method of electrically connecting a wiring board and an electrode on a semiconductor chip using a bonding wire having a diameter of several tens to several hundreds of micrometers. When joining by the WB method, the mechanical strength of the bonding wire used as a connection means may be weak. In addition, since a wide wiring space is required, it may not be possible to sufficiently meet demands for high-density wiring and miniaturization and thinning of devices.

  On the other hand, the FC method is a method in which protruding terminals called bumps arranged in an array are arranged on a wiring board, and a semiconductor chip is mounted via the bumps to electrically connect them. In the FC method, as a method of forming solder bumps on the semiconductor chip, for example, a method of forming solder on the aluminum electrode on the circuit forming surface of the semiconductor chip and further heating the solder to form hemispherical bumps, For example, a method of forming a small spherical bump by bonding a gold wire to an aluminum electrode. Further, in order to increase the mechanical strength of the electrical connection portion or to improve the water resistance, in the subsequent process, for example, the whole or a part of the semiconductor device in the WB method, for example, between the wiring board and the semiconductor chip in the FC method. Is generally sealed with an insulating sealing resin such as an epoxy resin (also called an underfill material in the FC method). When bonding by the FC method, the wiring board and the semiconductor chip are only bonded by bumps. Therefore, even if the semiconductor device is stressed from below or from the side, even if it is resin-sealed, the wiring board In some cases, the semiconductor chip may come off. Also, since the wiring board, semiconductor chip, and underfill material have different linear expansion coefficients, the wiring board and the semiconductor chip are greatly warped due to the difference in the linear expansion coefficient between the joined materials, and the chip is damaged or detached. In addition, abnormal operation may occur. Although it may be possible to prevent the problem of warping by configuring the wiring board with a harder material, the recent trend is that the semiconductor chip board is still made of a thin and brittle material, so it is still easily damaged. It was not possible to solve all the problems by improving only.

In order to solve these problems, for example, a method of constructing a semiconductor device by interposing an interposer substrate between a wiring substrate and a semiconductor chip has been proposed, and its practical application has been studied.
The interposer substrate has a structure in which through holes having a diameter of several tens of μm to several hundreds of μm are periodically provided in a silicon or glass substrate, and the through holes are filled with a highly conductive material. The mounting form using the interposer substrate is described in, for example, Patent Document 1 and Patent Document 2. Furthermore, rather than mounting a semiconductor chip on a wiring board by using the WB method or the FC method, it is possible to use an interposer substrate to bond the entire surface of the wafer, for example, at the wafer level where the semiconductor device is formed. It is desired from the point of lowering.

  In recent years, the density of semiconductor chips has been increased, and in addition to electrical connection, heat dissipation from semiconductor devices has been required. In general, Cu (thermal conductivity up to 400 W / m · K) is used as the filler for the interposer substrate, but a filler with higher thermal conductivity is desired in order to further improve heat dissipation. It is rare. Examples of the material having high thermal conductivity include carbon nanotubes (Patent Document 3, Non-Patent Documents 1 and 2). According to Kim et al., Carbon nanotubes have a thermal conductivity of 3000 W / K · m or more, and due to their conductivity, studies have been made on using carbon nanotubes as a filler (Non-patent Document 1). Patent Document 3 describes that carbon nanotubes can be grown in the vertical direction on a substrate by applying the catalyst on the substrate and growing the catalyst as a starting point.

JP-A-11-288978 JP 2000-31345 A JP 2003-183012 A

P. Kim et al., Physical Review Letters 87 (21), 215502-1 to -4 (2001). A. Kawabata et al., Japan Journal of Applied Physics 52, 110117-1 to -4 (2013)

When the carbon nanotubes are grown and filled in the through-holes of the interposer substrate, there are the following problems when applied to applications that increase electrical connection and heat dissipation.
First, in order to establish an electrical connection, for example, it is necessary to grow carbon nanotubes longer than the same length as the thickness of the interposer substrate. When an interposer substrate with carbon nanotubes grown out of a through-hole is bonded to a substrate on which a semiconductor chip or device structure is formed at the wafer level, for example, the entire surface of the substrate is bonded by plasma bonding or direct bonding. When joining, the surface to be joined has unevenness due to the carbon nanotubes, so that it was not possible to join well. On the other hand, if the carbon nanotubes are grown shorter than the thickness of the interposer substrate, that is, if they are grown shallower than the height of the substrate surface around the through-hole, the problem of flatness at the time of bonding is eliminated, but electrical connection is obtained. There wasn't. In order to obtain smoothness suitable for electrical connectivity and bonding, the carbon nanotubes fall off from the through holes when the interposer substrate on which the carbon nanotubes have grown out of the through holes is washed and polished. There was a problem. For this reason, an SOG (Silicon on Glass) film is formed on the surface of an interposer substrate on which carbon nanotubes are grown so as to protrude from the through holes, and chemical mechanical polishing (CMP) is also being studied. However, since the SOG film is an insulator and the thermal conductivity is about SiO ₂ (about 1.5 W / m · K), there is a problem that heat dissipation is deteriorated.

  Next, regarding heat dissipation, as described above, high thermal conductivity of carbon nanotubes alone has been reported, but the density per unit area of carbon nanotubes grown on a substrate is low. When grown into a through-hole, the void ratio in the through-hole is increased, so that sufficient heat dissipation may not be obtained. Non-Patent Document 2 has been studied to increase the density per unit area of the carbon nanotube, and reports that heat dissipation is improved by increasing the area density. However, the heat dissipation of carbon nanotubes in this report does not reach the heat dissipation when filled with Cu, which is an existing filler, and further improvement in density is desired.

  In addition to the study of filling the through-holes with only carbon nanotubes, the present inventors have combined and filled the carbon nanotubes and Cu, and filled the voids between the through-holes and the carbon nanotubes with Cu, so that only Cu is obtained. We also considered increasing heat dissipation rather than filling with. However, when the carbon nanotubes are filled in a form protruding from the through hole in order to obtain electrical connection of the through hole, the surface has to be smoothed by CMP before bonding to the semiconductor chip. In addition, when CMP is performed on the surface on which Cu is formed, dents are generated due to erosion, dishing, or the like, and when the surface in this state is bonded to another substrate, voids may be generated on the bonding surface. .

  As described above, when carbon nanotubes are used as fillers for the through holes of the interposer substrate, they are bonded to the surface filled with the conductive material protruding into the through holes, that is, to other substrates such as semiconductor chips. There is a problem in that the surface cannot be joined well with other substrates because of the difference in level. Even when graphene, which is theoretically said to have higher thermal conductivity than carbon nanotubes, is applied, it fills in a form that protrudes from the through-hole, thus causing the above-mentioned problems and finding a suitable joining method. There was a need.

  In view of the above problems, an object of the present invention is, for example, a carbon nanotube having a through hole and a trench for wiring (trench), and having a high thermal conductivity useful for increasing the heat dissipation of the semiconductor device from the through hole and the trench. Alternatively, a substrate laminate capable of firmly bonding a substrate such as an interposer filled with graphene and a metal material so as to protrude from another substrate such as a semiconductor chip at the wafer level, that is, the entire wafer surface, and a manufacturing method thereof It is to provide.

According to one aspect of the present invention, a plurality of through holes or grooves and a surface filled with the through holes or grooves and having the through holes or grooves have a height of more than 0 μm and less than 10 μm from the surface to be joined. A pressurizing step in which a surface of an interposer substrate provided with a conductive material protruding to the surface and a surface on which a metal layer of another substrate is formed are opposed to each other by pressurizing at a pressure of 5 kgf / cm ² or more. A method for producing an interposer substrate laminate including at least a pressing step in which the conductive material is composed of a metal material and a carbon material can be provided.
In addition, according to another aspect of the present invention, a plurality of through holes or grooves, and the through holes or grooves filled with the through holes or grooves have a surface exceeding 0 μm from the surface to be joined. An interposer substrate provided with a conductive material protruding to a height of 10 μm or less, a metal layer provided on a surface of the interposer substrate on which a through hole or a groove is to be joined, and the metal An interposer substrate laminate including at least another substrate provided on the layer can be provided.

  According to the present invention, for example, a carbon material having a high thermal conductivity such as carbon nanotube or graphene and a metal material such as Cu are protruded from the through-hole or groove, and the position is higher by a predetermined range than the surface of the substrate. Even when a substrate such as an interposer filled up to is used and bonded to another substrate such as a semiconductor chip over the entire surface of the substrate, a substrate laminate having few voids over the entire bonding interface can be obtained. The obtained interposer substrate laminate has good bonding properties at the bonding interface between the interposer substrate and other substrates, and can obtain excellent heat dissipation.

It is a schematic diagram of the manufacturing method of the interposer board | substrate laminated body of one Embodiment of this invention. It is a schematic diagram of the manufacturing method of the interposer board | substrate laminated body of another one Embodiment of this invention.

  Hereinafter, an embodiment for carrying out the present invention will be described in detail, but the scope of the present invention is not limited to this embodiment.

According to one embodiment of the present invention, it is possible to provide a method for manufacturing an interposer substrate laminate including another substrate via a metal layer on an interposer substrate.
Examples of the material for the interposer substrate include a substrate made of an organic material such as silicon, glass, and polyimide. In particular, silicon is preferable because it is easy to process in forming a through hole or a groove. The thickness of the interposer substrate is not particularly limited, but may be 30 to 500 μm.

The interposer substrate includes a plurality of through holes. The through hole penetrates in the thickness direction of the interposer substrate. The shape of the through hole is not particularly limited, but may be a circle, an ellipse, a square, a rectangle, or the like. When the shape of the through hole is circular, the diameter is not particularly limited, but may be 10 to 500 μm. Although it does not specifically limit about another shape, 78.5-196250micrometer ² may be sufficient as a cross-sectional area. The interposer substrate includes a plurality of through holes, and includes at least two or more through holes that can form a pitch width. The interposer substrate may have, for example, 2500 through holes per 1 cm ² . The plurality of through holes may have the same shape or different shapes, and may have the same cross-sectional area or different cross-sectional areas. The through holes may be provided periodically or randomly depending on the application. For example, when a circular through-hole having the same diameter is provided, the through-holes are periodically provided at regular intervals such that the center of each through-hole, that is, the circular central portion is arranged in a grid pattern. In this state, a through hole is provided. For example, when the interposer substrate has three circular through holes with the same diameter, they may be arranged in a line at equal intervals, and arranged so that the distances between the centers of the three through holes are the same. May be. The pitch width between the through holes is not particularly limited, but may be equal intervals, different intervals, or 10 to 500 μm.

  The interposer substrate may further include a groove (trench). In some cases, the interposer substrate may include a plurality of grooves instead of the through holes. Unlike the through hole, the groove portion is a groove that does not penetrate the substrate and has a depth from the surface of the interposer substrate in the thickness direction of the substrate. Although the deepest part of a groove part is not specifically limited, 10-50% of depth with respect to the thickness of an interposer board | substrate may be sufficient. The cross-sectional shape of the groove when viewed from the cross-section of the interposer substrate is not particularly limited, but may be a shape in which a semicircular and semi-elliptical arc portion faces downward, or a rectangle or a square. The width of the groove formed on the surface of the interposer substrate is not particularly limited, but may be 10 to 500 μm. The shape of the opening of the groove formed on the surface of the interposer substrate may be, for example, a circle, an ellipse, a square, a rectangle, or the like, similar to the above-described through hole. Depending on the use of the interposer, the length and number of the grooves can be set. For example, a plurality of grooves, for example, two or more, may be provided, and each may have the same shape or different shapes. Further, it may be provided periodically or randomly. When the interposer substrate does not have a through hole and is provided with a groove on one side, before or after the conductive material is provided on the groove, from the surface opposite to the surface provided with the groove to the thickness at which the groove becomes a through hole. Alternatively, grinding, polishing, gas phase or liquid phase etching, or an etching process combining them may be performed to form a substrate having through holes. Alternatively, after the pressurizing step, an etching process may be performed from the surface of the interposer substrate that is not bonded to another substrate of the interposer substrate laminate to a thickness at which the groove portion becomes a through hole.

The interposer substrate includes a plurality of through-holes or grooves, and a conductive material that fills the through-holes or grooves and protrudes from the surface to be joined having the through-holes or grooves to a height of more than 0 μm to 10 μm or less With.
The conductive material used for filling the through hole or the groove is composed of a metal material and a carbon material, and it is preferable to use at least one of each material. Examples of the metal material include Cu, Ta, W, Al, Au, Ag, Pt, and Ti, and at least one material is used. In particular, Cu is preferable because of its high electrical conductivity and practical use as a wiring material. The carbon material is not particularly limited, graphene, carbon materials are mentioned nanosized sp ² bond, such as carbon nanotubes, at least one material is used. Graphene is basically a sheet-like substance made of sp ² bonded carbon having a thickness of 1 atom. The sheet shape of the graphene in the present invention may be two-dimensional, for example, one spread handkerchief, or three-dimensional, for example, a single handkerchief rounded, and all are the same. Different shapes may be included even if it is a shape. The graphene sheets may be used in an isolated state or in a state where a plurality of sheets are overlapped. The carbon nanotube basically has a structure in which a sheet of graphene is rolled into a cylindrical shape, and may be a single-walled structure having one cylindrical structure. It may be a two-layer structure in which two carbon nanotubes are coaxially stacked, or may be a multilayer structure in which a plurality of carbon nanotubes having different diameters in a cylindrical structure are coaxially stacked. The diameter of the outermost layer of the carbon nanotube may be 0.4 to 100 nm. The length of the carbon nanotube is not particularly limited, but may be a length depending on the thickness of the interposer substrate, and is long enough to protrude from the surface of the interposer substrate to a height of 0 μm to 10 μm. It may be good. In particular, it is preferable to use carbon nanotubes from the viewpoint of high thermal conductivity and flexibility.

  When filling the through hole or groove of the interposer substrate with at least two kinds of conductive materials, for example, a metal material and a carbon material may be filled simultaneously or alternately, or one of the materials may be filled first. After that, the other material may be filled. For example, when the metal material is Cu and the carbon material is carbon nanotubes, the through holes or grooves are filled with carbon nanotubes first, and then Cu is filled between the inner walls of the through holes or grooves and the carbon nanotubes. The gap may be filled.

  Examples of the filling method of the metal material include a plating method, a chemical vapor deposition (CVD) method, a physical vapor deposition (PVD) method, and the like, and one of these methods may be used. Two methods may be used. The carbon material may be used in the shape of the carbon material described above before filling the through hole or groove portion, or may be formed in the shape of the carbon material described above when filling the through hole or groove portion. Good. For example, before filling the through hole or groove, carbon nanotubes are prepared in advance, mixed with a paste-like or solution-like metal material, and the carbon material is simultaneously inserted into the through-hole or groove using a plating method or the like. May be filled. When carbon nanotubes are formed when filling the through holes or grooves, they can be grown in the through holes or grooves using general carbon nanotube production methods such as arc, laser ablation, and CVD. Good. In any of the filling methods, for example, a shielding (masking) tape or the like may be used so that these conductive materials are not deposited on the surface of the interposer substrate other than the through hole or the groove. Also, for example, by using an acidic aqueous solution such as hydrochloric acid or sulfuric acid, the surface of the interposer substrate other than the through-hole or the groove is formed by immersing the substrate, applying it on the substrate surface, or performing spin etching. You may remove the adhering filler.

The through-hole or groove portion of the interposer substrate is formed from the surface of the interposer substrate, that is, the surface to be joined to another substrate in a later step, for example, using the filling method described above. It may be filled in a protruding form to a height exceeding 0 μm, preferably 10 μm or less, more preferably 5 μm or less, and even more preferably 1 μm or less. When the conductive material is filled in such a way that it protrudes from the surface of the interposer substrate to a height of more than 0 μm and not more than 10 μm, it exists between the interposer substrate and the other substrate when bonding the other substrates. The conductive material is easily bent and deformed. When the conductive material is filled in a form protruding from the surface of the interposer substrate to a height exceeding 10 μm, the conductive material present between the interposer substrate and the other substrate when bonding the other substrate, For example, the deformation deformation of the carbon nanotube becomes insufficient, the bonding strength of the entire surface is weak, and the carbon nanotube is easily peeled off. When the conductive material is filled at a height lower than 0 μm so as not to protrude from the surface of the interposer substrate, it is difficult to obtain an electrical connection when this surface is joined to another substrate. When the interposer substrate has a through hole, the conductive material is filled in a form that protrudes from the surface of the opening at one or both ends of the through hole of the interposer substrate to a height of 10 μm or less exceeding 0 μm. It may be. When the interposer substrate includes a groove portion, for example, a catalyst such as Al, Fe, or a metal composite that combines these is placed on the groove portion of the interposer substrate, and 1.0 to 1.0 × 10 ⁴ Pa After growing carbon nanotubes from 0 μm to, for example, 1 μm from the surface to be bonded to another substrate by CVD using acetylene gas or the like at 200 to 800 ° C. in a reduced pressure atmosphere, plating method It is good also as filling of the predetermined protruding form by filling Cu with. In addition, after filling the groove portion with a conductive material, before or after the pressurizing step for bonding to another substrate, grinding and polishing from the surface opposite to the surface including the groove portion to a thickness at which the groove portion becomes a through hole Further, there may be included a step of penetrating the groove by performing vapor phase or liquid phase etching, or an etching process combining them. Even when the groove portion is penetrated after filling with the conductive material in this way, the conductive material in the through hole has the same filling state as the interposer substrate provided with the through hole from the beginning.

Examples of the other substrate include an SOI (Silicon On Insulator) substrate and the like in addition to a silicon substrate and a glass substrate. The other substrate may be an interposer substrate or an existing semiconductor chip. The SOI substrate is a substrate including a silicon thin film layer that can form a device layer on an insulator substrate, and an SOS (Silicon on Sapphire) substrate having an sapphire, quartz, glass substrate, or the like as an insulator substrate, an SOQ ( (Silicon on Quartz) substrate, SOG substrate, and the like may be used, and depending on applications, a semiconductor substrate may be used instead of an insulator substrate, and a bonded substrate may be bonded to a silicon substrate.
A commercially available SOI substrate may be used or manufactured. As a manufacturing method, for example, a silicon substrate in which hydrogen ions are implanted on the bonding surface side and an insulator substrate are bonded together, and then a heat treatment of approximately 500 ° C. or more is performed to thermally peel the ion-implanted layer. A SmartCut method obtained by transferring a silicon thin film onto a substrate, and a silicon substrate implanted with hydrogen ions on the bonding surface side and an insulator substrate are bonded together, and the ion-implanted layer is mechanically peeled off at room temperature to provide an insulator. Examples thereof include a SiGen method obtained by transferring a silicon thin film onto a substrate, but are not particularly limited thereto, and these steps may be combined. For example, the silicon substrate and the insulator substrate may be bonded together with an adhesive or the like, and the surface opposite to the bonding surface of the silicon substrate may be thinned by polishing or the like. In the SOI substrate, the insulator substrate and the silicon substrate are bonded to each other after the pressurizing step for bonding to the interposer substrate from the viewpoint of obtaining good heat dissipation performance when the interposer substrate laminate is formed. It is desirable that they are bonded to such an extent that they can be removed. Alternatively, an SOI substrate having a buried oxide film may be formed by bonding an oxide film on a surface to which at least one of a silicon substrate and an insulator substrate is bonded. The thickness of the silicon thin film can be selected according to the application, but is preferably 5 to 500 nm, for example, and can be adjusted by polishing or etching.

  In some cases, after the other substrate is bonded to the interposer substrate, for example, only the silicon thin film layer is provided on the interposer substrate, so that the silicon substrate and the insulating substrate are bonded in advance with an adhesive having low adhesive strength. Alternatively, an SOI substrate in which a surface opposite to the bonding surface of the silicon substrate is thinned by grinding, polishing, vapor phase or liquid phase etching, or a combination thereof may be used. In this case, the surface of the silicon thin film layer of the SOI substrate and the interposer substrate are joined via a metal layer to form a substrate laminate, that is, after the pressurizing step, between the silicon thin film layer and the insulator substrate. By removing the adhesive layer mechanically or chemically, an interposer substrate having only a silicon thin film layer can be produced. As a method of removing the insulator substrate from the interposer substrate laminate, for example, by applying a mechanical impact to the adhesive layer or bonding surface between the silicon layer and the insulator substrate using a sharp peeling tool such as a wedge, The insulator substrate can be mechanically separated. Further, for example, by immersing a portion from an end surface on the side of the insulator substrate of the interposer substrate laminate to an adhesive layer or a bonding surface with the silicon layer in, for example, alkali or acid, for example, by dissolving the adhesive layer, the insulator substrate Can be chemically separated.

The other substrate is formed with a metal layer on the surface of the other substrate, preferably by vapor deposition, before joining with the interposer substrate, that is, before the pressing step.
The metal material forming the metal layer is preferably at least one selected from the group consisting of Au, Cu, Hf, Ta, and W. The metal layer is formed on the surface of another substrate facing the interposer substrate. Au or Cu is more preferable because it is desirable that the metal layer be easily deformed by the malleability of the metal material when bonded to the interposer substrate. In some cases, when the metal component of the metal layer diffuses and affects the device or the like after forming the substrate laminate, it is preferable to use a refractory metal such as Hf, Ta, or W that does not easily diffuse into the device. In particular, the surface of a metal layer formed of Au is difficult to be oxidized under atmospheric pressure, and can be bonded under atmospheric pressure during bonding. The surface of the metal layer formed of Cu, Hf, Ta or W is easily oxidized under atmospheric pressure. The metal layer desirably has no oxide film formed from the viewpoint of maintaining electrical conductivity and maintaining thermal conductivity. For this reason, before bonding, that is, before the pressurizing step, the metal layer is subjected to a vacuum condition (1.0 × 10 ^{−4 to} 1.0 × 10 ⁻⁸ Pa), and the oxide film on the surface thereof is Ar ion It is preferable to bond under the same vacuum condition after removing the surface by sputtering or the like to activate the surface. Examples of the method for forming the metal layer include a vapor deposition method, and are not particularly limited, but vacuum deposition, sputtering, and the like are used. The thickness of the metal layer may be such that the metal layer does not peel from the substrate, and is preferably in the range of 0.5 nm to 1 μm, more preferably 0.5 to 100 nm. If it is less than 0.5 nm, voids are likely to be formed on the bonding surface, and the bonding force after bonding becomes insufficient. When the thickness is 1 μm or more, the metal layer may be peeled off from the substrate when the metal layer is formed.

In some cases, the surface of the interposer substrate filled with the conductive material protruding from its surface to a height of more than 0 μm and not more than 10 μm may be provided with a metal layer, preferably by vapor phase epitaxy. That is, before the pressurizing step, a metal layer may be formed by vapor phase growth on the surface of the interposer substrate that is brought into contact with another substrate. In this case, a metal layer having the same thickness may be formed on the surface of the interposer substrate by using the same metal material and method as the metal layers formed on the other substrates. Further, when the metal material filled in the through-holes of the interposer substrate is Cu, an oxide film may be formed on the surface of the metal material, so that the vacuum condition (1.0 × 10 ^{−4 to} 1.0 × It is preferable to form the metal layer after removing the oxide film by sputtering using Ar ions and the like at 10 ⁻⁸ Pa). By providing the interposer substrate also with the metal layer, it is possible to increase the bonding strength when the substrate laminate is formed.

A conductive material that protrudes from the surface of the other substrate on which the metal layer thus obtained is formed and the surface to be joined having a through hole or a groove to a height of more than 0 μm and not more than 10 μm is provided. The surfaces of the interposer substrate are opposed to each other, and bonding is performed by pressing at a pressure of 5 kgf / cm ² or more. That is, the surface of the interposer substrate from which the conductive material protrudes from the through hole or the groove and the surface of the other substrate on which the metal layer is formed are brought into contact with each other and pressed by pressing at 5 kgf / cm ² or more. Then, a substrate laminate is obtained.
When bonding, it is desirable that the surface of the interposer substrate to be bonded and the surface of the other substrate are not formed with an oxide film and the surfaces are activated. For this reason, before the pressurizing step, surface activation treatment may be performed on the surface of the interposer facing the other substrate and / or the surface on which the metal layer of the other substrate is formed. For example, in the case where an oxide film is formed on the surfaces to be bonded, or when the adhesive strength at the bonding interface is improved, as described above, under vacuum conditions (1.0 × 10 ^{−4 to} 1.0 × 10 ⁻ It is preferable to bond under the same vacuum condition after removing the oxide film and / or activating the surface of the substrate surface by sputtering using Ar ions at ⁸ Pa).
The pressure at the time of pressurization is preferably 5 kgf / cm ² or more, more preferably 50 kgf / cm ² or more. If it is less than 5 kgf / cm ² , when an interposer substrate filled with a conductive material protruding from the surface to a height of 10 μm or less exceeding 0 μm is used, deformation of the filling becomes insufficient, and bonding is performed. A void is generated at the interface, and it is easy to peel off. The holding time at the time of pressurization is not particularly limited, but is preferably 10 seconds to 1 hour, more preferably 30 seconds to 30 minutes, and further preferably 1 minute to 10 minutes. If it is less than 10 seconds, bonding may be partially insufficient. Moreover, even if it exceeds 1 hour, joining strength does not change. Joining may be performed under atmospheric pressure, and may be performed under vacuum pressure (1.0 × 10 ^{−4 to} 1.0 × 10 ⁻⁸ Pa) in some cases. For example, when the surface to which the interposer substrate and the other substrate are bonded is not covered with Au that is not easily oxidized, the vacuum condition (1.0 × 10 ^{−4 is maintained} after the surface activation treatment described above is performed. It is preferable to join at ~ 1.0 × 10 ⁻⁸ Pa).

  By the above manufacturing method, an interposer substrate laminate including another substrate via a metal layer on the interposer substrate can be obtained. That is, a plurality of through-holes or groove portions and a conductive material filled in the through-holes or groove portions and protruding from the surface to be joined having the through-holes or groove portions to a height of more than 0 μm and 10 μm or less are provided. Interposer substrate comprising at least an interposer substrate, a metal layer provided on a surface to be joined having a through hole or a groove of the interposer substrate, and another substrate provided on the metal layer A laminate can be obtained. According to the present invention, since the interposer substrate and another substrate are pressure-bonded via the metal layer made of malleable metal material, the conductive material such as carbon nanotube exceeds 0 μm from the surface. In the case of using an interposer substrate that is filled in a form that protrudes to a height of 10 μm or less, the carbon nanotube is bent and deformed at the bonding interface, and the interposer substrate that is generated by the carbon nanotube that protrudes from the through hole or groove and other Since the gap between the substrate and the metal layer is filled with metal, the substrate laminate is excellent in electrical connection at the bonding interface, excellent in heat dissipation, and excellent in bonding properties, without generating a gap in the bonding interface. . Since the filling material of the interposer substrate laminate is excellent in electrical connectivity, the resistivity of the filling material is small, and thus the current capacity of the interposer substrate laminate can be increased. As a method for evaluating electrical connectivity, for example, electrodes are formed on both end faces of a through hole filled with a filler, and the resistivity is measured. In addition, since the interposer substrate laminate has good heat dissipation, when the heat generated in the device is dissipated by the filler formed in the interposer, the temperature rise of the device can be suppressed more than before. As a heat dissipation evaluation method, for example, a device temperature is confirmed by thermography. Furthermore, the interposer substrate laminate has good bondability, there are few voids on the bonding surface between the interposer substrate and another substrate, and the bonding strength is suitable for use in subsequent processes. For example, even when a part of the other substrate side is ground after the interposer substrate laminate is formed, the possibility of peeling at the joint surface between the interposer substrate and the other substrate is low. As a method for evaluating bondability, for example, there is a method for confirming whether or not peeling occurs even when a blade is inserted into the bonding interface.

Although the manufacturing process of the interposer board | substrate laminated body concerning this invention is not specifically limited, The one aspect | mode is shown in FIG. According to this, the plurality of through-holes 11 and the conductive material 12 that fills the through-holes 11 and protrudes from the surface to be joined having the through-holes 11 to a height of more than 0 μm and 10 μm or less. Metal layers 14a and 14b are formed on the surface of the interposer substrate 10 provided and the surface of the other substrate 13 (step A). The surface of the interposer substrate 10 on which the metal layer 14a is formed and the surface of the other substrate 13 on which the metal layer 14b is formed are opposed to each other by being pressed at a pressure of 5 kgf / cm ² or more. In addition, an interposer substrate laminate 16 including another substrate 13 can be obtained via the metal layer 14 (consisting of 14a and 14b) (step B).

Moreover, the manufacturing process of the interposer board | substrate laminated body of another one aspect | mode concerning this invention is shown in FIG. According to this, the plurality of groove portions 21a and the conductive material 22 that fills the groove portions 21a and protrudes from the surface on the side to be joined to another substrate 23 in a later step to a height of more than 0 μm and 10 μm or less. The metal layers 24a and 24b are formed on the surface of the interposer substrate 20 and the surface of the other substrate 23 (step A). The surface of the interposer substrate 20 on which the metal layer 24a is formed and the surface of another substrate 23 on which the metal layer 24b is formed are opposed to each other and bonded by pressing at 5 kgf / cm ² or more to obtain a bonded body 25. (Process B). Etching is performed on the surface opposite to the bonding surface on the interposer substrate 20 side of the obtained bonded body 25 to form the through hole 21 from the groove 21a, and the metal layer 24 (24a and 24a and 24) is formed on the interposer substrate 20. 24b), an interposer substrate laminate 26 provided with another substrate 23 can be obtained (step C).

  The interposer substrate laminate may further include a metal layer on the surface opposite to the surface on which the other substrate of the interposer substrate is bonded, in order to bond the wiring substrate and the like. In this case, the conductive material filled in the through holes protrudes from the surface to a height of 10 μm or less exceeding 0 μm on the surface bonded to the wiring board or the like as well as the surface bonded to the other substrate. May be. In other words, on both sides of the interposer substrate, when the conductive material filling the through-holes protrudes from the surface to a height of more than 0 μm and not more than 10 μm, after each side is provided with a metal layer, By bonding to the substrate and the wiring substrate, it is possible to obtain an interposer substrate laminate provided on the wiring substrate via a metal layer.

<Example 1>
A silicon substrate having an outer diameter of 150 mm and a thickness of 625 μm was used as the interposer substrate. On the silicon substrate, 2500 grooves with a diameter of 100 μm per cm ^{2 and} a depth of 100 μm in the thickness direction of the substrate were formed with a pitch width of 200 μm on the silicon substrate. A Fe / Al catalyst, which is a catalyst, is placed on the bottom of the groove formed in the silicon substrate, and carbon nanotubes are formed on the silicon substrate under a reduced pressure atmosphere of 1.0 × 10 ³ Pa and 600 ° C. by CVD using acetylene gas. It was grown until it protruded about 2 μm from the surface. Thereafter, the substrate is immersed in a 12 wt% CuSO ₄ solution, filled with Cu by an electrolytic plating method using a galvanostat (current density 1 mA / cm ² ), and the gap between the inner wall of the groove and the carbon nanotube is filled. A Poser substrate was obtained. When the cross-section of the interposer substrate was observed with an electron microscope (SEM) (not shown), the composite of carbon nanotubes and Cu was filled into the through holes, and further filled to a height that protruded 2 μm from the surface of the silicon substrate. It was.
As another substrate, a silicon substrate having an outer diameter of 150 mm and a thickness of 625 μm was used. An Au layer having a thickness of 30 nm was formed on the surface of another substrate by sputtering using CFS-4ES manufactured by Shibaura Mechatronics. Furthermore, a room temperature bonding apparatus made by Musashino Engineering was used on the surface of the interposer substrate having a filling up to a height of 2 μm from the surface under vacuum conditions (1.0 × 10 ^{−4 to} 1.0 × 10 ⁻⁸ Pa). Then, a sputtering method using Ar ions was performed for 1 minute to remove the Cu surface oxide film, and then an Au layer was formed to a thickness of 30 nm by the same sputtering method as for other substrates.
Next, the surface of the interposer substrate on which the Au metal layer is formed and the surface of the other substrate are brought into contact with each other under atmospheric pressure and room temperature (25 ° C.), and then hot press bonding made by Tester Sangyo. Using an apparatus, bonding was performed by applying a load of 60 kgf / cm ² and holding for 1 minute to obtain a bonded body. Using a CMP (Chemical Mechanical Polishing) polishing apparatus on the surface opposite to the surface bonded to the other substrate on the interposer substrate side of the obtained bonded body, the thickness on the interposer substrate side becomes 100 μm. The interposer substrate laminate provided with another substrate on the interposer substrate through the metal layer was obtained by forming the through hole from the groove.
The obtained interposer substrate laminate maintained a bonded state without peeling even when a blade was inserted into the bonded interface. When the cross section of the interposer substrate laminate was observed with an SEM (not shown), the carbon nanotubes and Cu filled in the through holes were bent and deformed at the bonding interface, and the interposer substrate and the other substrates were bonded at the bonding interface. It was confirmed that bonding was made without forming voids. In addition, in order to evaluate the thermal diffusivity of the interposer substrate laminate, it was heated to 100 ° C. for 60 minutes from the other substrate side which is one end surface using a hot plate, The surface temperature on the interposer substrate side which is the end face was measured by thermography using an infrared camera. As a result, the surface temperature on the interposer substrate side was 95 ° C, indicating almost the same temperature as the temperature of the heat source applied from the other substrate side, confirming that the interposer substrate laminate has high heat dissipation did it.

<Example 2>
In the same manner as in Example 1, an interposer substrate having a groove filled with carbon nanotubes and Cu was obtained to a height that protruded 1 μm from the surface of the silicon substrate.
As another substrate, a silicon substrate having an outer diameter of 150 mm and a thickness of 625 μm was used. An Au layer having a thickness of 30 nm was formed on the surface of another substrate by sputtering using CFS-4ES manufactured by Shibaura Mechatronics.
Next, a vacuum condition of 1.0 × 10 ⁻⁶ Pa and a room temperature (on the surface of the interposer substrate having a filling up to a height of 1 μm from the surface and the surface of another substrate on which the Au metal layer is formed) 25 ° C.), a sputtering method using Ar ions was performed for 1 minute using a room temperature bonding apparatus manufactured by Musashino Engineering, and the surface oxide film of Cu on the interposer substrate was removed and surface activation was performed. Thereafter, the surface of the interposer substrate subjected to the surface activation treatment and the surface of another substrate are brought into contact with each other under a vacuum condition of 1.0 × 10 ⁻⁶ Pa and room temperature (25 ° C.), and then the same vacuum. Under the conditions and room temperature, using a normal temperature bonding apparatus manufactured by Musashino Engineering, the same procedure as in Example 1 was performed except that bonding was performed by applying a load of 60 kgf / cm ² and holding for 1 minute. Got the body.
The obtained interposer substrate laminate maintained a bonded state without peeling even when a blade was inserted into the bonded interface. When the cross section of the interposer substrate laminate was observed with an SEM (not shown), the carbon nanotubes and Cu filled in the through holes were bent and deformed at the bonding interface, and the interposer substrate and the other substrates were bonded at the bonding interface. It was confirmed that bonding was made without forming voids. Further, as a result of evaluating the thermal diffusibility of the interposer substrate laminate in the same manner as in Example 1, the surface temperature of the interposer substrate laminate on the side of the interposer substrate is 90 ° C., and the interposer substrate laminate is It was confirmed that it has high heat dissipation.

<Example 3>
An interposer substrate laminate was obtained in the same manner as in Example 1 except that bonding was performed by applying a load of 30 kgf / cm ² and holding for 1 minute.
The obtained interposer substrate laminate maintained a bonded state without peeling even when a blade was inserted into the bonded interface. When a cross section of the interposer substrate laminate was observed with an SEM (not shown), the carbon nanotubes and Cu filled in the through holes were bent and deformed at the bonding interface, and the load during pressurization compared to Example 1 was increased. It was confirmed that the interposer substrate and the other substrate were bonded without forming a void at the bonding interface even when the size was reduced. Further, as a result of evaluating the thermal diffusibility of the interposer substrate laminate in the same manner as in Example 1, the surface temperature of the interposer substrate laminate on the side of the interposer substrate was 93 ° C., and the interposer substrate laminate was It was confirmed that it has high heat dissipation.

<Example 4>
In the same manner as in Example 1, Musashino was used on the surface of an interposer substrate on which a metal layer of Au was formed and the surface of another substrate under vacuum conditions of 1.0 × 10 ⁻⁶ Pa and room temperature (25 ° C.). Surface activation was performed by applying a sputtering method using Ar ions for 1 minute using an engineering room temperature bonding apparatus. Thereafter, the surface of the interposer substrate subjected to the surface activation treatment and the surface of another substrate were brought into contact with each other under a vacuum condition of 1.0 × 10 ⁻⁶ Pa and at room temperature (25 ° C.), and then Musashino Engineering. An interposer substrate laminate was obtained in the same manner as in Example 1 except that bonding was performed by applying a load of 30 kgf / cm ² and holding for 1 minute using a room temperature bonding apparatus.
The obtained interposer substrate laminate maintained a bonded state without peeling even when a blade was inserted into the bonded interface. When a cross section of the interposer substrate laminate was observed with an SEM (not shown), the carbon nanotubes and Cu filled in the through holes were bent and deformed at the bonding interface, and the load during pressurization compared to Example 1 was increased. It was confirmed that the interposer substrate and the other substrate were bonded without forming a void at the bonding interface even when the size was reduced. Further, as a result of evaluating the thermal diffusibility of the interposer substrate laminate in the same manner as in Example 1, the surface temperature of the interposer substrate laminate on the side of the interposer substrate was 93 ° C., and the interposer substrate laminate was It was confirmed that it has high heat dissipation.

<Example 5>
An interposer substrate laminate was obtained in the same manner as in Example 1 except that bonding was performed by applying a load of 6 kgf / cm ² and holding for 1 minute.
The obtained interposer substrate laminate maintained a bonded state without peeling even when a blade was inserted into the bonded interface. When the cross-section of the interposer substrate laminate was observed with an SEM (not shown), the carbon nanotubes and Cu filled in the through holes were bent and deformed at the bonding interface, and compared with Examples 1 and 3 when pressurized. It was confirmed that the interposer substrate and the other substrate were bonded without forming a void at the bonding interface even when the load of the substrate was reduced. Further, as a result of evaluating the thermal diffusibility of the interposer substrate laminate in the same manner as in Example 1, the surface temperature of the interposer substrate laminate on the side of the interposer substrate was 91 ° C., and the interposer substrate laminate was It was confirmed that it has high heat dissipation.

<Comparative Example 1>
An interposer substrate laminate was obtained in the same manner as in Example 1 except that bonding was performed by applying a load of 1 kgf / cm ² and holding for 1 minute. When the obtained interposer substrate laminate was released from the apparatus by releasing the pressure, it was peeled off at the bonding interface, and the bonded state could not be maintained. If the load at the time of bonding is insufficient, the carbon nanotubes and Cu filled in the through-holes cannot be bent and deformed at the bonding interface, and voids are generated at the bonding interface, so that it is considered that the bonding was not performed.

<Comparative example 2>
An interposer substrate laminate was obtained in the same manner as in Example 2 except that bonding was performed by applying a load of 1 kgf / cm ² and holding for 1 minute. When the obtained interposer substrate laminate was released from the apparatus by releasing the pressure, it was peeled off at the bonding interface, and the bonded state could not be maintained. Compared to Comparative Example 1, surface activation by sputtering using Ar ions was added, but bonding was not possible. If the load at the time of bonding is insufficient, the carbon nanotubes and Cu filled in the through-holes cannot be bent and deformed at the bonding interface, and voids are generated at the bonding interface, so that it is considered that the bonding was not performed.

<Comparative Example 3>
Using the same method as in Example 1, except that an interposer substrate in which carbon nanotubes and Cu were filled to a height that protruded 20 μm from the surface of the silicon substrate into the groove portion was produced, the same procedure as in Example 1 was performed. Got. When the obtained substrate laminate was released from the apparatus by releasing the pressure, it was peeled off at the bonding interface, and the bonded state could not be maintained. Although the bonding conditions were the same as in Example 1, the interposer substrate in Comparative Example 3 was too high in height from the carbon nanotubes filled in the through holes and Cu to the substrate surface. It seems that it became insufficient.

  In the embodiment described above, the interposer substrate is formed using the silicon substrate having the groove portion in order to confirm the bondability of the interposer substrate. However, the present invention is not limited to this, and other interposer substrates are used. The same effect can be obtained even if

10, 20: Interposer substrate 11, 21: Through hole of interposer substrate 21a: Groove portion of interposer substrate 12, 22: Conductive material 13, 23: Other substrates 14, 14a, 14b, 24, 24a, 24b: Metal layer 25: bonded body 16, 26: interposer substrate laminate

Claims (10)

A plurality of through-holes or grooves, and a conductive material that fills the through-holes or grooves and protrudes from the surface to be joined having the through-holes or grooves to a height of more than 0 μm to 10 μm or less. A pressing step in which the surface of the interposer substrate and the surface of the other substrate on which the metal layer is formed are opposed to each other by pressing at a pressure of 5 kgf / cm ² or more, wherein the conductive material is a metal material and carbon made of a material, at least seen including a pressurizing step, the metal layer of the other substrate, Au, Cu, Hf, at least one metal selected from the group consisting of Ta and W, of the other substrate The manufacturing method of an interposer board | substrate laminated body whose thickness of a metal layer is 0.5-100 nm .   The manufacturing method of the interposer board | substrate laminated body of Claim 1 whose said metal material is Cu.   The manufacturing method of the interposer board | substrate laminated body of Claim 1 or 2 whose said carbon material is a carbon nanotube or graphene. The interposer according to any one of claims 1 to 3 , wherein the interposer substrate is a silicon substrate, a glass substrate, or a polyimide substrate, and the other substrate is a silicon substrate, a glass substrate, or an SOI substrate. A method for manufacturing a substrate laminate. The method for manufacturing an interposer substrate laminate according to any one of claims 1 to 4 , wherein the interposer substrate includes a metal layer formed on a surface from which the conductive material protrudes. The method for producing an interposer substrate laminate according to claim 5 , wherein the metal layer provided on the interposer substrate is at least one metal selected from the group consisting of Au, Cu, Hf, Ta, and W. The manufacturing method of the interposer board | substrate laminated body of Claim 5 or 6 whose thickness of the metal layer with which the said interposer board | substrate was equipped is 0.5-100 nm. The interposer substrate laminate according to any one of claims 1 to 7 , wherein the pressurizing step is performed under a vacuum condition of 1.0 x ^10-4 Pa to 1.0 x ^10-8 Pa. Production method. The method further includes a step of performing a surface activation process on the surface of the interposer substrate to be bonded and / or the surface of the metal layer to be bonded of the other substrate before the pressurizing step. method of manufacturing an interposer substrate laminate according to any one of 1-8. A plurality of through-holes or grooves, and a conductive material that fills the through-holes or grooves and protrudes from the surface to be joined having the through-holes or grooves to a height of more than 0 μm to 10 μm or less. An interposer board,
A metal layer provided on a surface of the interposer substrate on the side to be joined having the through hole or the groove , wherein the metal layer is selected from the group consisting of Au, Cu, Hf, Ta, and W At least one metal, wherein the metal layer has a thickness of 0.5 to 100 nm ,
An interposer substrate laminate comprising at least another substrate provided on the metal layer.

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