Embodiments disclosed in this application relate to the field of semiconductor technologies, and more specifically, to a semiconductor apparatus and an electronic device that includes the semiconductor apparatus.
In a packaging process of an integrated circuit, a semiconductor die may be bonded to another component such as an interconnection layer or a package substrate, and a formed package structure is referred to as a three-dimensional integrated circuit (3D IC). Heat dissipation is a challenge in the 3D IC.
In a typical 3D IC (for example, a chip-on-wafer-on-substrate (CoWoS) package), heat may accumulate in an inner region at a bottom of a die stack, resulting in a significant local temperature peak (which is also referred to as a hot spot). In addition, a hot spot caused due to heat generated by a high power consumption die may cause a thermal crosstalk problem to a surrounding die, and consequently adverse impact is exerted on performance of the surrounding die and reliability of the entire 3D IC package. This local hot spot problem described by using the 3D IC as an example also widely exists in other semiconductor die package structures (for example, a 2.5D IC package).
This application provides a semiconductor apparatus, to resolve a local hot spot problem in the semiconductor apparatus to some extent. In addition, this application further provides an electronic device. The electronic device includes the semiconductor apparatus.
According to a first aspect disclosed in this application, a semiconductor apparatus is provided. The semiconductor apparatus includes: a first semiconductor layer; a second die; a thermally conductive layer, where the thermally conductive layer is stacked with the first semiconductor layer and the second die, is located between the first semiconductor layer and the second die, and is configured to conduct heat from the first semiconductor layer and/or heat from the second die at the thermally conductive layer, and a coefficient of thermal conductivity of the thermally conductive layer in a horizontal direction is greater than or equal to a coefficient of thermal conductivity in a vertical direction; and a first conductive pillar, where the first conductive pillar penetrates through the thermally conductive layer, so that the first semiconductor layer and the second die are electrically interconnected by using the first conductive pillar, the first conductive pillar is electrically insulated from the thermally conductive layer, an extension direction of the first conductive pillar is the vertical direction, and the coefficient of thermal conductivity of the thermally conductive layer in the horizontal direction is greater than a coefficient of thermal conductivity of the first semiconductor layer.
The first semiconductor layer and/or the second die may generate heat in a working process, and the heat may be unevenly distributed in the horizontal direction. The thermally conductive layer is stacked with the first semiconductor layer and the second die, and the coefficient of thermal conductivity of the thermally conductive layer in the horizontal direction is greater than or equal to the coefficient of thermal conductivity in the vertical direction. Therefore, the heat can be spread in the horizontal direction, to achieve a heat spreading effect in the horizontal direction, so as to alleviate or eliminate a local hot spot effect. In addition, the first conductive pillar is disposed at the thermally conductive layer, to electrically interconnect the first semiconductor layer and the second die. The thermally conductive layer is usually a conductive material. Therefore, when the thermally conductive layer is electrically insulated from the first conductive pillar, an electrical function of the first conductive pillar is not affected, to ensure that the semiconductor apparatus can work normally.
In some embodiments, there are a plurality of vias at the thermally conductive layer, and one or more first conductive pillars penetrate through one of the vias.
A quantity of vias and a quantity of conductive pillars may be determined based on a specific requirement of a die. Dies are usually interconnected by using a plurality of vias. A size of the conductive pillar is usually determined based on a semiconductor manufacturing process, a size and performance of the die, and the like. It is easier to manufacture a via with a large aperture at lower costs. Therefore, to reduce manufacturing costs of the thermally conductive layer, a via in which a plurality of conductive pillars can be accommodated may be used. In some cases, to improve heat spreading performance, a relatively small via may be manufactured, to retain the thermally conductive layer as much as possible. In other words, only one conductive pillar is accommodated in one via.
In some embodiments, there is a bonding-based connection between the thermally conductive layer and the first semiconductor layer.
The bonding-based connection is a connection that is implemented without using adhesive or a welding layer and that can significantly reduce thermal resistance between the thermally conductive layer and the first semiconductor layer. Therefore, the heat can be quickly spread in the horizontal direction through the thermally conductive layer, to improve the heat spreading effect.
In some embodiments, the semiconductor apparatus further includes an insulating material, the insulating material covers a surface of the thermally conductive layer, and the first conductive pillar further penetrates through the insulating material.
The insulating material covers the surface of the thermally conductive layer, and therefore a conductive path between the thermally conductive layer and another element is cut off, and accordingly an electrical operation of the semiconductor apparatus is not affected.
In some embodiments, the semiconductor apparatus further includes an insulation layer that is disposed to at least partially surround the first conductive pillar and extend along the first conductive pillar and that is configured to isolate the first conductive pillar from the thermally conductive layer to implement electrical insulation.
The insulation layer is disposed to surround the first conductive pillar, so that the first conductive pillar can be electrically insulated from the thermally conductive layer.
In some embodiments, the semiconductor apparatus further includes a filler material that is disposed at the thermally conductive layer and that is located between the thermally conductive layer and the insulation layer.
In a process of drilling the thermally conductive layer, to reduce costs, vias with relatively large apertures may be manufactured. Therefore, the filler material is required to fill these vias, to reduce difficulty of forming the conductive pillar.
In some embodiments, the filler material is compatible with a through silicon via (TSV) process, and a through silicon via refers to an electrical interconnection implemented by filling a via of a silicon wafer with a conductive material.
The filler material is compatible with the TSV process. Therefore, a process of punching the filler material may be implemented by using a known semiconductor manufacturing process, to implement good process compatibility.
In some embodiments, the first semiconductor layer is a first die or a first interconnection layer.
In some embodiments, when the first semiconductor layer is a first die, the first conductive pillar further penetrates through the first die.
In some embodiments, the semiconductor apparatus further includes a third semiconductor layer that is disposed on a side that is of the first semiconductor layer and that is far away from the thermally conductive layer, and the third semiconductor layer is electrically coupled to the conductive pillar.
In some embodiments, the thermally conductive layer includes a carbon-based material, a metal material, or a combination thereof.
In some embodiments, the carbon-based material includes a graphene film.
In some embodiments, a thickness of the thermally conductive layer is at least 5 μm.
According to a second aspect, an electronic device is provided, and includes the semiconductor apparatus according to the first aspect.
In some embodiments, the electronic device includes a switch, a router, a mobile phone, a personal digital assistant (PDA), a navigation device, a set-top box, a music player, or a video player.
According to a third aspect, a heat spreader is provided, and includes: a carbon-based material layer, where a coefficient of thermal conductivity of the carbon-based material layer in a horizontal direction is greater than or equal to a coefficient of thermal conductivity in a vertical direction; and a first non-metal pillar that penetrates through the carbon-based material layer, where an extension direction of the first non-metal pillar is the vertical direction, the first non-metal pillar is made of an insulating material or a semiconductor material, and a part that is of the first non-metal pillar and that is in contact with the carbon-based material layer is an insulating material.
The heat spreader may be used in a semiconductor package structure, and is configured to spread heat for a die in the semiconductor package structure. An electrical interconnection structure is allowed to be manufactured in the first non-metal pillar. Therefore, an electrical property of the semiconductor die is not affected while heat is spread for the semiconductor die. The part that is of the first non-metal pillar and that is in contact with the carbon-based material layer is an insulating material. Therefore, if a conductive pillar is formed in the first non-metal pillar, the insulating material may electrically insulate the conductive pillar.
In some embodiments, surface roughness of a thermally conductive layer is less than or equal to 1 nm.
In some embodiments, a diameter of the first non-metal pillar is between 10 μm and 40 μm.
The summary is provided to describe selection of concepts in a simplified form, and the concepts are further described in the following specific embodiments. The summary is not intended to identify key features or main features disclosed in this application, and is not intended to limit the scope disclosed in this application.
The foregoing and other objectives, features, and advantages disclosed in this application become more apparent by describing, with reference to the accompanying drawings, in more detail the example embodiments disclosed in this application. In the example embodiments disclosed in this application, same reference numerals usually represent same components.
The various feature parts shown in the accompanying drawings may not be drawn to scale in accordance with common practice. Therefore, for clarity, sizes of the various feature parts may be randomly extended or reduced. In addition, all components of a given system, method, or device may not be depicted in some accompanying drawings. Finally, in the entire specification and the accompanying drawings, similar reference numerals may be used to represent similar feature parts.
The embodiments in this application are described below in more detail with reference to the accompanying drawings. The term “include” and a variant thereof used in this specification represent non-exclusive inclusion, in other words, represent “including but not limited to”. Unless specifically stated, the term “or” means “and/or”. The term “and/or” in this specification describes only an association relationship for describing associated objects and represents that three relationships may exist. For example, A and/or B may represent the following three cases: Only A exists, both A and B exist, and only B exists. The term “based on” means “at least partially based on”. The terms “an example embodiment” and “an embodiment” mean “at least one example embodiment”. The term “another embodiment” means “at least one another embodiment”. The terms “first”, “second”, and the like may refer to different objects or a same object. Other explicit and implied definitions may be further included below.
Any reference to a direction or an orientation is intended only for ease of description, and is not intended to limit the scope of the present disclosure in any manner. For example, related terms such as “lower”, “upper”, “horizontal”, “vertical”, “above”, “below”, “upward”, “downward”, “top”, “bottom”, and derivatives (for example, “horizontally”, “up”, and “down”) thereof are used in the description to refer to orientations described below or shown in the accompanying drawings. These related terms are intended only for ease of description, and do not require an apparatus to be constructed or operated in a particular orientation.
A semiconductor apparatus for alleviating or eliminating a local hot spot problem and a method for manufacturing a semiconductor apparatus are provided according to various example embodiments. Herein, an intermediate stage of forming the semiconductor apparatus is shown, and a plurality of embodiments and variants thereof are described. In various views and example embodiments, similar reference numerals are used to represent similar elements.
For example, a second die may be disposed above the thermally conductive layer 102, the first semiconductor layer 114 may include the first die, a third semiconductor layer may be disposed below the first semiconductor layer 114, and the third semiconductor layer may include a third die. Therefore, there may be heat sources above and below the thermally conductive layer 102. A coefficient of thermal conductivity of the thermally conductive layer 102 in a horizontal direction may be greater than or equal to a coefficient of thermal conductivity in a vertical direction, to facilitate heat conduction in the horizontal direction. In addition, the coefficient of thermal conductivity of the thermally conductive layer 102 in the horizontal direction is greater than a coefficient of thermal conductivity of the first semiconductor layer 114. The heat from the part above and/or the heat from the part below the thermally conductive layer 102 may be distributed as evenly as possible on an entire plane of the thermally conductive layer 102 by using the thermally conductive layer 102. In this way, a local hot spot problem in the semiconductor apparatus can be alleviated or eliminated.
There may be a bonding-based connection between the thermally conductive layer 102 and the first semiconductor layer 114, for example, there is a bonding-based connection implemented without using adhesive or a welding layer or bonding-based fastening implemented by using a wafer bonding process or a surface activated bonding (SAB) process. In this way, thermal resistance between the thermally conductive layer 102 and the first semiconductor layer 114 can be significantly reduced, and therefore a hot spot at the first semiconductor layer 114 can be quickly spread through the thermally conductive layer 102.
A conductive pillar 130 penetrates through the thermally conductive layer 102, so that the second die above the thermally conductive layer 102 is electrically interconnected with the first semiconductor layer 114. In an example, an electrical contact of the first semiconductor layer 114 may be disposed on an upper surface, to form a conductive interconnection with the conductive pillar 130. In another example, an electrical contact of the first semiconductor die 114 may be disposed on a lower surface of the first semiconductor layer 114, and the conductive pillar 130 may penetrate through the first semiconductor layer 114 and the thermally conductive layer 102, to electrically interconnect the second die above the thermally conductive layer 102 and the first semiconductor layer 114. In still another example, when the third semiconductor layer is disposed below the first semiconductor layer 114, the conductive pillar 130 may also penetrate through the first semiconductor layer 114 and the thermally conductive layer 102, to vertically interconnect the second die above the thermally conductive layer 102 and the third semiconductor layer below the first semiconductor layer 114.
The conductive pillar 130 is electrically insulated from the thermally conductive layer 102, to implement insulation isolation. For example, electrical insulation may be implemented by disposing one or more dielectric layers between the conductive pillar 130 and the thermally conductive layer 102. This depends on a specific process. A thickness of the dielectric layer may be tens of nanometers. In some examples, to reduce difficulty of punching the thermally conductive layer 102, holes with relatively large apertures are manufactured at the thermally conductive layer 102. In this case, these holes may be filled with a filler material compatible with a through silicon via (TSV) process, for example, silicon or silicon dioxide. A through silicon via refers to an electrical interconnection implemented by filling a via of a silicon wafer with a conductive material. This structure is compatible with a 3D or 2.5D IC package or the like, and therefore is very convenient for application to a related field. The conductive pillar 130 may include a barrier layer, a seed layer, and a through conductor (for example, copper). This may be implemented by using the TSV process. It should be understood that the term “conductive pillar” does not mean that a cross section is in a round shape. For example, the cross section may alternatively be in various suitable shapes such as an elliptic shape and a polygonal shape. In addition, the term “conductive pillar” does not mean that there is a same cross-sectional shape or size in a length direction of the entire conductive pillar. For example, different cross sections of the conductive pillar in an extension direction (for example, the vertical direction in
For example, a shape of the conductive pillar is associated with a shape of the hole, and the shape of the hole is affected by different punching processes. For example, in a laser punching process, the shape of the hole is usually a structure in which there is a relatively large size at an upper part and a relatively small size at a lower part. In a TSV Bosch process, the hole is generally in a cylindrical shape. During structuring of the conductive pillar, there may further be a hole in the conductive pillar due to a process limitation.
The thermally conductive layer 102 may be made of various thermally conductive materials, for example, a carbon-based material, a metal material, or a combination thereof, especially a graphene film. A thickness of the thermally conductive layer 102 may be at least 5 μm, for example, is between 5 μm and 1000 μm; for another example, is between 10 μm and 300 μm; or for still another example, is between 20 μm and 100 μm, and especially, is between 30 μm and 60 μm. In a conventional semiconductor manufacturing process, a functional layer of the semiconductor apparatus is usually manufactured by using a thin film deposition process such as chemical vapor deposition (CVD) or a thin film synthesis process, and a thicknesses of a thin film formed by using these semiconductor processes is usually at a nanometer level. The thermally conductive layer 102 with a relatively large thickness is used. Therefore, in this embodiment disclosed in this application, a good heat spreading effect can be achieved, and a local hot spot effect can be better eliminated. An in-plane coefficient of thermal conductivity of the thermally conductive layer 102 may be greater than 600 W/mK. When the graphene film is used, the in-plane coefficient of thermal conductivity may be greater than 1000 W/mK or even greater than 1200 W/mK.
The graphene film is formed by spirally stacking a plurality of graphene layers. Unlike graphite, graphene is formed through regular AB stacking (half of carbon atoms at a graphene layer are located on another atom of a lower graphene layer, and the other half of the carbon atoms are located in a center of a hexagon that includes carbon atoms at the lower graphene layer). For example, the graphene film may be made of a graphene nano sheet, for example, may be made of a graphene nano sheet that has a thickness less than 5 nm and a plane size that is between 1 micron and 100 microns. The graphene film may further be combined with other materials, for example, combined with materials such as Cu, SiC, Si, SiO2, and Al2O3, to implement higher strength while maintaining a high in-plane coefficient of thermal conductivity, and match a process of manufacturing a via at the thermally conductive layer 102. For example, a combination process may be to deposit reinforced materials such as a metal, non-metal, or metal/non-metal oxide, a nitride, a carbide, and a fluoride on a surface of and inside the graphene film through CVD. Alternatively, a combination process may be to infiltrate metal such as Al and Cu on a surface of and inside the graphene film under a high temperature and high pressure. It should be understood by a person skilled in the art that the graphene film may be combined with other materials by using another suitable process.
The graphene film has excellent in-plane thermal conductivity. For example, an in-plane coefficient of thermal conductivity of the graphene film may be between 1500 W/mK and 1700 W/mK. Therefore, heat can be effectively conducted on a plane of the graphene film. However, the material of the thermally conductive layer 102 is not limited to the graphene film, and may alternatively be a graphene-based composite film such as a graphite/metal composite film, or may be a graphite film, a graphite/metal composite film, a metal/carbon composite film, even a copper alloy film, or the like. In these materials, the graphene film has a higher in-plane coefficient of thermal conductivity, and therefore is more suitable for conducting heat on the plane of the thermally conductive layer 102, to alleviate or eliminate a local hot spot problem.
Most of thermally conductive materials are also conductive materials. Therefore, the semiconductor apparatus 100 may further include an insulating material that covers a surface of the thermally conductive layer 102, to implement insulation isolation. The surface of the thermally conductive layer 102 not only includes an upper surface and a lower surface, but also includes a side surface in the via. The insulating material may include different structures based on different manufacturing processes. For example, in the example shown in
In addition, as shown in
In some embodiments, the semiconductor apparatus 100 may further include a second via 104. The second via 104 penetrates through at least the thermally conductive layer 102, and an aperture size of the second via 104 is greater than an aperture size of the first via 126, to surround the first via 126. The second via 104 may lower a process requirement for manufacturing the semiconductor apparatus 100. For example, the second via 104 with a relatively large size lowers an alignment requirement that exists when the first via 126 is formed, to help increase a yield and reduce manufacturing costs.
In one embodiment, the semiconductor apparatus 100 may further include a filler material 112, and the filler material 112 is disposed between the thermally conductive layer 102 and the insulation layer 128. The second via 104 may not be fully filled in a process of forming the insulation layer through deposition or the like. Therefore, the filler material 112 may be formed to fill the second via 104. The filler material 112 may be an insulating material (for example, silicon oxide), a semiconductor material (for example, silicon), or a combination thereof. The filler material 112 is usually compatible with the through silicon via (TSV) process, and therefore it is convenient to manufacture the first via 126. A through silicon via refers to an electrical interconnection implemented by filling a via of a silicon wafer with a conductive material. In one embodiment, the semiconductor apparatus 100 may further include an insulation layer 124. The insulation layer 124 may implement a passivation or protection function in a manufacturing process.
As described above, the semiconductor apparatus 100 may be compatible with various packaging processes. For example, the semiconductor apparatus 100 may be applied to a 3D or 2.5D IC package. For example, the first semiconductor layer 114 may be a first die, a second die may be disposed above the semiconductor apparatus 100, and the second die may be electrically coupled to the conductive pillar 130. In this way, the first die and the second die may be vertically interconnected by using a TSV. For example, the first die may have a thickness of 55 μm, may be made of a silicon-based material, and may have a coefficient of thermal conductivity that approximates to 90 W/mK. It should be understood that the foregoing parameters are provided only as examples, and may be adaptively modified based on a specific application.
In addition, the third semiconductor layer may be disposed below the first semiconductor layer 114, and the third semiconductor layer may be a third die or an interconnection layer. For example, the third semiconductor die may be electrically coupled to the conductive pillar 130 by using a bump or a solder ball, so as to be interconnected with the second die or another die above the second die. In a specific example, a high bandwidth memory (HBM) die stack includes a stack of a bottom-layer die and a plurality of core dies above the bottom-layer die. The bottom-layer die may be implemented as the first semiconductor layer 114 shown in
It should be understood that the semiconductor apparatus 100 is not limited to being implemented in an application in which there is an interconnection layer. Therefore, the semiconductor apparatus 100 may also be applied to a 2.5D IC package or a 3D IC package in which there is no interconnection layer, for example, applied to improving in-plane heat spreading capabilities of a plurality of layers of dies in an integrated fan-out (INFO) package.
The semiconductor apparatus 100 may be applied to various electronic devices, especially communications devices, for example, a switch, a router, a mobile phone, a personal digital assistant (PDA), a navigation device, a set-top box, a music player, and a video player. In addition, the semiconductor apparatus 100 may be compatible with various different package types, for example, a CoWoS package and an INFO package. Applications of the semiconductor apparatus 100 according to some embodiments disclosed in this application are described below with reference to a specific application.
The controller 202 and the bottom-layer die 206 are disposed side by side at an interconnection layer 208, and the interconnection layer 208 is disposed on a package substrate 210. A packaging material 212 packages these components, and forms an external contact on the package substrate 210, to form a die package. A physical layer (PHY) interface may be disposed on the controller 202 and the bottom-layer die 206, to allow data communication between dies.
As described above, there is a local hot spot problem in a 3D IC (for example, an HBM die), and die overheating or overtemperature may become one of key problems in subsequent heat dissipation of a 3D IC die. For example, a junction temperature specification of an HBM die that uses a DRAM process is only 95 degrees, which is significantly less than a junction temperature specification 105 degrees of a surrounding CMOS die. After a plurality of layers of HBM dies are stacked, heat of a bottom-layer die cannot be effectively conducted, and the bottom-layer die becomes a bottleneck in heat dissipation of the die.
A main reason for overheating of the HBM die is that a heat spreading capability of a silicon-based die is not high enough. A four-layer second-generation high bandwidth memory (HBM2) die stack is used as an example. In this case, a difference between a highest temperature and a lowest temperature of a local hot spot in a bottom die may be 24° C.
Existing mainstream measures for cooling the HBM die in the industry include disposing more dummy thermally conductive solder balls, using a hybrid bonding process with higher interconnection density, and the like. In these solutions, a thermal conductivity area between stacked HBM dies is increased to improve interlayer thermal resistance. In this way, impact of heat accumulation on temperature rise of the bottom die can be alleviated. However, a case in which a local hot spot problem in the HBM die is resolved by improving in-plane spreading thermal resistance of the die cannot be implemented. An in-plane heat spreading capability of the die needs to be improved, to quickly spread heat of the local hot spot in the die in a plane direction, so as to reduce the in-plane thermal resistance of the die.
Additionally or alternatively, in the semiconductor apparatus 300 shown in
In a conventional technology, when four layers of HBM2 dies are in a 2.0 Gbps working mode, a temperature of a highest temperature point in the bottom-layer die is 24° C. higher than a lowest temperature. A simulation model is constructed for the scenario in which there are four layers of HBM2 dies, and a scenario in which the temperature of the highest temperature point in the bottom-layer die is 24° C. higher than the lowest temperature is reconstructed. On this basis, a set of simulation conditions is added, and a thermally conductive material that has a thickness of 50 μm and an in-plane coefficient of thermal conductivity of 1500 W/mK is added to the bottom-layer die.
A size of the HBM die stack 404 is 11 mm×8 mm, power of the bottom-layer die is 4 W, and power of each DRAM HBM die is 0.75 W (4 W in total). In a simulation process, a temperature of the EMC 402 is fixed at a room temperature 25 degrees. A surface temperature of the bottom-layer die in the conventional technology is between 63° C. and 87° C. (ΔT=24° C.). According to this embodiment disclosed in this application, a surface temperature of the bottom-layer die is between 65° C. and 75° C. (ΔT=12° C.). A thermal simulation result shows that an in-plane temperature difference of the bottom-layer die may be reduced from 24° C. to 12° C., in other words, an in-plane heat spreading capability of the silicon-based bottom-layer die is doubled. This is equivalent to that a temperature specification of a die in a memory die module in a 3D IC die package is increased by 12° C.
As described above, in addition to a graphene film, another thermally conductive material such as a graphene-based composite film, a graphite film, a graphite/metal composite film, a metal/carbon composite film, or even a copper alloy film may be used.
When these non-graphene film materials are used, it is difficult to obtain an in-plane coefficient of thermal conductivity that is greater than 1500 W/mK, but it is easy to obtain an in-plane coefficient of thermal conductivity that is greater than 400 W/mK. Based on the simulation model shown in
The example embodiments disclosed in this application are described below with reference to a specific environment, for example, a die-on-wafer-on-substrate (CoWoS) package. More specifically, the CoWoS package includes a multi-layer memory die stack. The stack includes a bottom-layer die and one or more layers of core dies disposed above the bottom-layer die. However, the example embodiments disclosed in this application are also applicable to another package type and another die structure, including another three-dimensional integrated circuit (3D IC) package, another 2.5D IC package, and the like.
A via 504 may be formed in the graphene film 502 based on a predefined position.
To lower a requirement for high-precision alignment in a backend process, a diameter size of the via 504 may be greater than an aperture of a through silicon via (TSV) of the bottom-layer die and the core die in the HBM stack. For example, in an example of a four-layer second-generation high bandwidth memory (HBM2) die stack, there are 5024 I/Os, a corresponding area is approximately 1 mm×6 mm, via density may be approximately 170 per square millimeter, a typical via diameter is approximately between 10 μm and 40 μm, and a maximum via diameter is approximately 76 μm. It should be understood that these values are provided only as examples, and are not intended to limit the scope of the present disclosure.
The via 504 may be manufactured by using various punching processes, including laser punching, drill drilling, and the like. Before the via 504 is manufactured, a mask may be manufactured based on a preset position requirement, to determine a punching position, so as to facilitate manufacturing of the via 504. It should be understood that the via 504 may be manufactured by using any other suitable technology.
Then, the graphene film 502 may be bonded to a first carrier wafer 508, to facilitate subsequent processing. For example, as shown in
The first carrier wafer 508 may be made of a material such as glass or silicon. A size of the first carrier wafer 508 may be consistent with a size of the graphene film 502, for example, 4 inches, 6 inches, 8 inches, or 12 inches. In some cases, the size and a shape of the graphene film 502 may be inconsistent with those of the first carrier wafer 508. Therefore, the graphene film 502 may be cut into a round size, and then the graphene film 502 may be attached to a surface of the first carrier wafer 508 by using the bonding material 506.
As shown in
As shown in
Based on a specific process method and a requirement, the insulating material 510 may include a plurality of material layers, for example, a passivation layer, a barrier layer, and a dielectric layer. For example, the insulating material 510 may be deposited by using various methods, for example, physical deposition or chemical deposition.
The via 504 in the graphene film 502 has a relatively large size, and therefore may be difficult to be evenly filled by using a film deposition process. In this case, after insulation isolation is implemented on the sidewall of the via 504 by using the insulating material 510, a filler material 512, for example, an insulating material (for example, silicon oxide) and/or a semiconductor material (for example, silicon), compatible with a semiconductor TSV process may be formed in the via 504.
After the filler material 512 is formed in the via 504, surface leveling may be implemented by using various suitable polishing processes. For example, surface roughness that is less than or equal to 1 nm (for example, less than 0.5 nanometers) may be implemented, to facilitate subsequent bonding to the bottom-layer die.
In some embodiments, the first carrier wafer 508 may be removed by virtue of a peelable property of the bonding material 506, to form a heat spreader. The heat spreader includes a carbon-based material layer (for example, the graphene film 502), and a coefficient of thermal conductivity of the carbon-based material layer in a horizontal direction is greater than or equal to a coefficient of thermal conductivity in a vertical direction. In addition, the heat spreader further includes a first non-metal pillar. The first non-metal pillar penetrates through the carbon-based material layer (for example, the graphene film 502), and the first non-metal pillar is made of an insulating material or a semiconductor material, for example, silicon or silicon oxide. In an example shown in
In
During bonding of the graphene film 502 and the first semiconductor layer 514, the via 504 in the graphene film 502 and a position at which a TSV via needs to be manufactured and that is at the first semiconductor layer 514 may be preliminarily aligned as required.
In
In
In addition, an insulating material 516 is formed on an exposed surface of the graphene film 502. For example, the insulating material 516 may be formed by using a deposition method, for example, physical deposition or chemical deposition. Before the insulating material 516 is formed, surface treatment such as grinding/cleaning may be performed on a surface of the graphene film 502, to improve surface flatness.
In some examples, the insulating material 516 may be a low-dielectric material that has a property such as temperature resistance that can meet a subsequent semiconductor manufacturing process, for example, silicon oxide. Other optional materials include at least one of silicon nitride, silicon carbide, silicon oxide, silicon oxycarbide, fluorinated silicon glass, carbon-doped silicon oxide, and polymer. For example, a thickness of the insulating material 516 may be approximately 100 nm. It should be understood that this value is provided only as an example, and is not intended to limit the scope of the present disclosure.
As shown in
In
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As shown in
In
After the via 526 is filled, unnecessary copper and an unnecessary barrier layer material on an upper surface may be removed through chemical mechanical grinding or the like, to form a structure shown in
Then, as shown in
In an example, the pad 532 on a side close to the graphene film 502 may be first manufactured, and after manufacturing is completed, the first semiconductor layer 514 is separated from the second carrier wafer 520. For example, the second carrier wafer 520 may be peeled off from the first semiconductor layer 514 based on a peelable property of the bonding material 518. Then, the pad 534 is manufactured at a bottom of the first semiconductor layer 514, and then an array of solder balls 536, for example, a micro boss copper pillar, is manufactured. In another example, the first semiconductor layer 514 may be first separated from the second carrier wafer 520, and then the pads 532 and 534 may be respectively formed at two ends of the via 526.
As shown in
As shown in
According to the first embodiment, a graphene film is integrated on one side of the bottom-layer die, and a TSV that penetrates through the graphene film is used as a vertical interconnection between the bottom-layer die and the core die. For the graphene film, a relatively large via is manufactured and a surface isolation measure is taken in advance, so that three-dimensional dies can be vertically interconnected after a highly thermally conductive and electrically conductive graphene film is integrated. In addition, the relatively large via manufactured in the graphene film in advance is filled with a material compatible with the TSV process, to significantly reduce difficulty of the TSV process in backend three-dimensional die integration.
A manufacturing method according to the first embodiment disclosed in this application is described above with reference to
A difference between the second embodiment and the first embodiment lies in a procedure of manufacturing a via in the graphene film 502. In the first embodiment, a plurality of vias 504 are manufactured in the graphene film 502 in the process procedures in
In
After a process procedure shown in
The third embodiment is similar to the first embodiment, and an in-plane temperature difference of a bottom-layer die can also be significantly reduced, to improve an in-plane heat-conducting capability of the bottom-layer die. In comparison with the first embodiment, an actual area of the graphene film 502 in the third embodiment is reduced, and performance of improving the in-plane temperature difference of the bottom-layer die may be slightly reduced. This specifically depends on the size of the via 504. However, the size of the via 504 is significantly increased, and therefore technical difficulty of manufacturing a via in the graphene film 502 can be significantly reduced in the third embodiment. In addition, in the third embodiment, the via 504 may be filled by using a process such as coating. In this way, costs can be significantly reduced in comparison with a deposition process.
In
In
In
As shown in
In
According to the fourth embodiment, a problem that there is in increase in process difficulty, complexity, and costs because of an excessively high TSV aperture ratio that is caused due to the fact that a TSV is manufactured in both a graphene film and a die wafer can be avoided.
In
In
In
In
In
In
In
In comparison with the first embodiment, in the fifth embodiment, punching is performed on a die side, which is compatible with the TSV process and ensures high precision of positioning a via. Then, punching is performed on a graphene side, and punching may be implemented by using a non-etching solution (for example, laser punching), to implement higher punching efficiency.
In the embodiments described above with reference to
In a block 1204, a first semiconductor layer stacked with the thermally conductive layer is formed. For example, the first semiconductor layer may be the first semiconductor layer 114 or the first semiconductor layer 514.
In a block 1206, a conductive pillar that penetrates through the first semiconductor layer is formed. The conductive pillar is electrically insulated from the thermally conductive layer. The conductive pillar may be the conductive pillar 130, 134, 530, or 550.
In some embodiments, the method 1200 may further include: forming a first insulation layer on a first surface of the thermally conductive layer. For example, as shown in
In some embodiments, the method 1200 may further include: forming a second insulation layer (for example, the insulating material 516) on a second surface of the thermally conductive layer (for example, the graphene film 502). The second surface is opposite to the first surface, as shown in
In some embodiments, the forming a first insulation layer (for example, the insulating material 510) includes: forming a second via (for example, the via 504) at the thermally conductive layer (for example, the graphene film 502), as shown in
In some embodiments, the bonding the first semiconductor layer (for example, the first semiconductor layer 514) to the first insulation layer (for example, the insulating material 510) includes: filling the second via (for example, the via 504) with a filler material (for example, the filler material 512), as shown in
In some embodiments, the forming a second insulation layer (for example, the insulating material 516) includes: forming the second insulation layer (for example, the insulating material 516) in the second via (for example, the via 504) and on the second surface of the thermally conductive layer (for example, the graphene film 502); and filling the second via (for example, the via 504) with the filler material (for example, the filler material 512), as shown in
In some embodiments, the forming a first via (for example, the via 526) includes: forming a third via (for example, the via 522) that penetrates through the second insulation layer (for example, the insulating material 516) and the filler material (for example, the filler material 512), as shown in
In some embodiments, the forming a first via (for example, the via 526) includes: forming the first via (for example, the via 526) that penetrates through the second insulation layer (for example, the insulating material 516), the filler material (for example, the filler material 512), and the first semiconductor layer (for example, the first semiconductor layer 514), as shown in
In some embodiments, the forming a first via (for example, the via 526) includes: forming a fifth via (for example, the via 522) and a sixth via (for example, the via 538) that penetrate through the second insulation layer (for example, the insulating material 516) and the filler material (for example, the filler material 512), as shown in
In some embodiments, the forming a conductive pillar (for example, the conductive pillar 530) includes: forming a fifth insulation layer (for example, the insulation layer 528) on a sidewall of the first via (for example, the via 526), as shown in
In some embodiments, a first end of the conductive pillar (for example, the conductive pillar 530) is interconnected with a contact of a first die (for example, the second die 540); and a second end of the conductive pillar (for example, the conductive pillar 530) is interconnected with a contact of a third semiconductor layer (for example, the third semiconductor layer 542).
In some embodiments, the forming a first via (for example, the via 526) includes: forming a tenth via (for example, the via 522) that penetrates through the second insulation layer (for example, the insulating material 516), the thermally conductive layer (for example, the graphene film 502), and the first insulation layer (for example, the insulating material 510), as shown in
In some embodiments, the thermally conductive layer includes a first conductive pillar (for example, the conductive pillar 530 shown in
In some embodiments, the forming a first via (for example, the via 526) includes: forming a twelfth via (for example, the via 558) at the first semiconductor layer (for example, the first semiconductor layer 514), as shown in
Although the embodiments of the present disclosure and the advantages of the embodiments are described in detail, it should be understood that various modifications, replacements, and variations may be made to the present disclosure without departing from the spirit and scope of the present disclosure defined by the appended claims. In addition, the scope of this application is not intended to be limited to the specific embodiments of the processes, machine apparatuses, manufacturing, material composition, tools, methods, and operations in this specification. It is easily understood by a person skilled in the art from the present disclosure that according to the present disclosure, processes, machine apparatuses, manufacturing, material composition, tools, methods, or operations that are existing or to be developed in the future and that perform basically the same functions or achieve basically the same results as the corresponding embodiments of the present disclosure may be used. Therefore, the appended claims are intended to include the processes, machine apparatuses, manufacturing, material composition, tools, methods, or operations in the protection scope of the claims. In addition, each claim forms a separate embodiment, and combinations of the claims and the embodiments fall within the scope of the present disclosure.
Number | Date | Country | Kind |
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202010531248.6 | Jun 2020 | CN | national |
This application is a continuation of International Application No. PCT/CN2021/099498, filed on Jun. 10, 2021, which claims priority to Chinese Patent Application No. 202010531248.6, filed on Jun. 11, 2020. The disclosures of the aforementioned applications are hereby incorporated by reference in their entireties.
Number | Date | Country | |
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Parent | PCT/CN2021/099498 | Jun 2021 | US |
Child | 18063529 | US |