The present application claims the benefit of priority to Chinese Patent Application No. CN 202110721421.3, entitled “Adapter Board for Packaging and Method Manufacturing the Same, and Semiconductor Packaging Structure”, filed with CNIPA on Jun. 28, 2021, and Chinese Patent Application No. CN 202121445637.3, entitled “Adapter Board for Packaging and Semiconductor Packaging Structure”, filed with CNIPA on Jun. 28, 2021, the contents of which are incorporated herein by reference in their entireties.
The present disclosure relates to the technical field of semiconductor packaging, in particular, to an adapter board for packaging and a method manufacturing the same, and a semiconductor packaging structure.
With the development of electronic products towards miniaturization, high performance and high reliability, and the system integration level has been increasing. In this case, the way to improve the performance of electronic products by further reducing the feature size of integrated circuits and the line width of interconnect lines have become limited by the physical characteristics of materials and equipment processes, thus the traditional Moore's law is difficult to continue to be developed. Currently, advanced packaging methods include: Wafer Level Chip Scale Packaging (WLCSP), Fan-Out Wafer Level Package (FOWLP), Flip Chip, Package on Package (POP), etc. The 2.5D/3D integration technology with Through-Silicon Vias (TSVs) as the core has been widely regarded as the leading technology in the field of high-density packaging in the future and an effective way to break Moore's law.
Traditional 2.5D/3D packaging structure generally includes a silicon adapter board with TSVs, and copper conductive pillars are formed in the TSVs to interconnect chips with a substrates. The process of exposing the copper conductive pillars in the backsides of the TSVs is called Backside Via Reveal (BVR). The process generally includes: grinding a back surface of a silicon substrate which contains TSVs, chemical mechanical polishing (CMP) the silicon substrate back surface, and etching that back surface of the silicon substrate. These steps may lead to diffusion of copper from the TSVs into the silicon substrate and eventually lead to the degradation of the performance of the entire package structure.
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Generally, the silicon substrate 103 is thick and the TSV 104 cannot penetrate the silicon substrate 103, so the silicon substrate 103 needs to be thinned, as shown in
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The present disclosure provides an adapter board for packaging and a method manufacturing the same, and a semiconductor packaging structure, so the copper in the TSVs is not easy to diffuse into the silicon substrate during the preparation of the silicon adapter board of the 2.5D/3D packaging structure, which eventually improve the performance of the entire packaging structure.
The method for manufacturing the adapter board for packaging includes: providing a stacked structure, the stacked structure includes a support substrate, a separation layer disposed on the support substrate, and a silicon substrate disposed on the separation layer, a Through-Silicon Via (TSV) extending vertically is formed in the silicon substrate, the TSV is filled with a copper conductive pillar, a diffusion barrier is formed between the copper conductive pillar and a side walls of the TSV; grinding a top surface of the silicon substrate until the TSV is exposed; polishing a top surface of the stacked structure using a chemical mechanical polishing process; etching the copper conductive pillar to a predetermined depth using a wet etching process to form an etching groove, and removing copper ground into a surface of the silicon substrate using a wet etching solution; filling the groove with a protective layer; etching the top surface of the silicon substrate to expose the copper conductive pillar; forming an insulating layer on the top surface of the silicon substrate using a chemical vapor deposition process.
Optionally, the wet etching solution is a copper etching solution and includes phosphoric acid and hydrogen peroxide.
Optionally, forming the stacked structure includes: providing the silicon substrate; forming the TSV in the silicon substrate; forming the diffusion barrier layer on the side walls of the TSV; filling the TSV with copper material to form the copper conductive pillar; and providing the support substrate and the separation layer, and bonding the support substrate to a side of the silicon substrate having the TSV through the separation layer to form the stacked structure.
Optionally, forming the protective layer includes: depositing a protective layer material on the top surface of the stacked structure using a chemical vapor deposition process until filling the etching groove; and polishing the top surface of the stacked structure to the top surface of the silicon substrate using a chemical mechanical polishing process to form the protective layer covering a top surface of the copper conductive pillar.
Optionally, forming the insulating layer includes: depositing an insulating layer material on the top surface of the stacked structure using a chemical vapor deposition process; and polishing the insulating layer material and the protective layer using a chemical mechanical polishing process to expose the copper conductive pillar to form the insulating layer covering the silicon substrate.
Optionally, a depth of the groove is between 1% and 2% of the length of the copper conductive pillar, and the material of the protective layer includes silicon oxide.
The present disclosure further provides an adapter board for packaging. The adapter board for packaging includes a separation layer, a support substrate, a silicon substrate, a TSV penetrating part of the silicon substrate, a copper conductive pillar, a diffusion barrier, and an insulating layer. The support substrate and the silicon substrate diffusion barrier, and an insulating layer. The support substrate and the silicon substrate are respectively bonded to a top surface and a bottom surface of the separation layer. The copper conductive pillar fills the TSV and protrudes from the TSV, copper particles in the copper conductive pillar do not diffuse into a surface of the silicon substrate. The diffusion barrier is formed between the copper conductive pillar and a side walls of the TSV and extends flush with the copper conductive pillar. The insulating layer is formed on the surface of the silicon substrate and covers a circumference of the copper conductive pillar.
Optionally, the support substrate includes one of a glass substrate, a metal substrate, a semiconductor substrate, a polymer substrate, and a ceramic substrate; the separation layer includes a polymer layer or an adhesive layer.
Optionally, the diffusion barrier layer includes one or a stack of at least two of a tantalum nitride layer, a titanium nitride layer, a silicon nitride layer, and a silicon oxide layer.
Optionally, the insulating layer includes one or a stack of two of a silicon nitride layer and a silicon oxide layer.
The present disclosure further provides a semiconductor packaging structure, including the adapter board for packaging as described in any one of the above.
As mentioned above, the present disclosure provides an adapter board for packaging and a method for manufacturing the same, and a semiconductor packaging structure. By forming the groove using a wet etching process, copper particles diffused into the surface of the silicon substrate in the previous process can be removed, and the groove can be used for the subsequent deposition of protective layer on the surface of the copper conductive pillar. In addition, the groove combined with the protective layer that fills the groove in the subsequent process can effectively prevent copper particles from diffusing into the silicon substrate during the etching of the silicon substrate. This avoids the possibility of diffusion of all copper conductive pillars into the silicon substrate during the entire manufacturing process of tin, e adapter board, effectively improving the performance of the packaging structure.
The embodiments of the present disclosure will be described below through specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present disclosure according to contents disclosed by the specification. The present disclosure can also be implemented or applied through other different specific implementation modes. Various modifications or changes can also be made to all details in the specification based on different points of view and applications without departing from the spirit of the present disclosure.
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The present disclosure provides a method for manufacturing an adapter board for packaging, to prevent copper particles diffusing from copper conductive pillars to a silicon substrate. The method is described as follows.
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By way of example, the support substrate 201 includes one of a glass substrate, a metal substrate, a semiconductor substrate, a polymer substrate, and a ceramic substrate. In this embodiment, the support substrate 201 is a glass substrate, the glass substrate has low costs, it is easy to form a separation layer 202 on the surface of the glass substrate, and the difficulty of the subsequent peeling process can be reduced.
The separation layer 202 is disposed between the silicon substrate 203 and the support substrate 201, and is preferably made of an adhesive material with a smooth surface such that the separation layer 202 has a seamless bonding contact with the silicon substrate 203 to ensure that the silicon substrate 203 in the subsequent processes will not shift, and the separation layer 202 also has a strong bonding force with the support substrate 201. Generally, the bonding force between the separation layer 202 and the support substrate 201 needs to be greater than the bonding force between the separation layer 202 and the silicon substrate 203. As an example, the separation layer 202 includes a polymer layer or adhesive layer, and the polymer layer or adhesive layer is first applied to a surface of the support substrate 201 by a spin-coating process and then cured by a UV-curing or heat-curing process.
In this embodiment, the polymer layer includes an LTHC photothermal conversion layer, and the LTHC photothermal conversion layer can be subsequently heated using a laser when peeling the support substrate 201 to separate the silicon substrate 203 and the support substrate 201 from each other at the LTHC photothermal conversion layer.
As an example, the diffusion barrier 206 includes one or a stack of at least two of a tantalum nitride layer, a titanium nitride layer, a silicon nitride layer and a silicon oxide layer.
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The groove 207 is formed using the wet etching process, first, copper particles diffused into the surface of the silicon substrate 203 in the previous process can be removed; further, the groove 207 provides a recessed place for the subsequent deposition of a protective layer on the surface of the copper conductive pillar 205. As an example, the etching solution used in the wet etching process can be any existing copper etching solution suitable for etching copper particles, the preferred wet etching solution in this embodiment includes phosphoric acid and hydrogen peroxide, hydrogen peroxide can oxidize copper to copper oxide, while phosphoric acid can etch off copper oxide, so as to achieve the etching of the copper conductive pillar 105. As an example, the depth D of the groove 207 is between 1% and 2% of the height of the copper conductive pillar 205, for example, when the height of the copper conductive pillar is 100 μm, the depth D of the groove generally ranges from 1 μm to 2 μm.
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As an example, the material of the protective layer 209 may include silicon etching protection materials which have a good etching selection ratio versus silicon. Preferably, the material of the protection layer in this embodiment is silicon oxide.
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As an example, the insulating layer 211 may be a single layer or a stacked layer, for example, the insulating layer 211 may be a single layer structure of silicon nitride or silicon oxide or a stacked layer structure of silicon oxide and silicon nitride.
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In this embodiment, by forming the groove 207 using a wet etching process, copper particles diffused into the surface of the silicon substrate 203 in the previous process can be removed, and the groove 207 can provide a space for the subsequent deposition of a protective layer on the outer surface of the copper conductive pillar 205. In addition, the groove 207 combined with the protective layer 209 that fills the groove 207 in the subsequent process can effectively prevent copper particles from diffusing into the silicon substrate 203 during the etching of the silicon substrate 203. This avoids the possibility of diffusion of all copper conductive pillars into the silicon substrate during the entire manufacturing process of the adapter board, effectively improving the performance of the packaging structure.
This embodiment provides an adapter board for packaging, the adapter board is manufactured using the method in Embodiment 1, the beneficial effects can be seen in Embodiment 1 and will not be repeated in the following.
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As an example, the support substrate 201 includes one of a glass substrate, a metal substrate, a semiconductor substrate, a polymer substrate, and a ceramic substrate; the separation layer 202 includes a polymer layer or an adhesive layer.
As an example, the diffusion barrier 206 includes one or a stack of at least two of a tantalum nitride layer, a titanium nitride layer, a silicon nitride layer and a silicon oxide layer.
As an example, the insulating layer 211 includes one or a stack of two of a silicon nitride layer and a silicon oxide layer.
This embodiment further provides a semiconductor packaging structure, and the semiconductor packaging structure includes the adapter board for packaging as described above.
In summary, the present disclosure proposes an adapter board for packaging and a method for manufacturing the same, and a semiconductor packaging structure. By forming the groove using a wet etching process, copper particles diffused into the surface of the silicon substrate in the previous process can be removed, and the groove can be used for the subsequent deposition of protective layer on the surface of the copper conductive pillar. In addition, the groove combined with the protective layer that fills the groove in the subsequent process can effectively prevent copper particles from diffusing into the silicon substrate during the etching of the silicon substrate. This avoids the possibility of diffusion of all copper conductive pillars into the silicon substrate during the entire manufacturing process of the adapter board, effectively improving the performance of the packaging structure. Therefore, the present disclosure effectively overcomes the shortcomings of the prior art and has a high industrial use value.
While particular elements, embodiments, and applications of the present invention have been shown and described, it is understood that the invention is not limited thereto because modifications may be made by those skilled in the art, particularly in light of the foregoing teaching. It is therefore contemplated by the appended claims to cover such modifications and incorporate those features which come within the spirit and scope of the invention.
Number | Date | Country | Kind |
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202121445637.3 | Jun 2021 | CN | national |
CN 202110721421.3 | Jun 2021 | CN | national |