Glass-based IC carrier transition layer, method for manufacturing the same, and glass-based IC carrier

Abstract

This application relates to a transition layer for a glass-based IC substrate and its preparation method, belonging to the field of integrated circuit packaging substrate manufacturing technology. The transition layer is an organic polymer film deposited on the surface of a glass substrate and the inner wall of a TGV via using plasma-enhanced chemical vapor deposition (PECVD). The thickness of the transition layer is 0.1-0.5 μm. The organic polymer film and the glass substrate have enhanced interfacial adhesion through a dual mechanism of chemical bonding and physical anchoring. The bonding strength between the transition layer and the glass substrate is 0.85-1.05 N / mm. Within a TGV via with an aspect ratio of 10:1, the thickness difference between the orifice and the bottom is within 10%. This application achieves a bonding strength of 0.85-1.05 N / mm between the organic polymer transition layer and the glass substrate through the synergistic effect of plasma surface activation and PECVD deposition.

Description

Technical Field

[0001] This application belongs to the field of integrated circuit packaging substrate manufacturing technology, specifically relating to a transition layer of a glass-based IC substrate and its preparation method. Background Technology

[0002] Glass-based materials are gradually becoming the core substrate for next-generation high-performance IC substrates due to their excellent electrical properties (low dielectric constant, low dielectric loss), high dimensional stability, good heat resistance, and thermal expansion coefficient matching that of silicon chips. However, glass substrates face a key bottleneck in practical applications—the interfacial bonding between the metal layer and the glass surface. The smooth and chemically inert surface of glass makes it difficult to form a strong bond with metals such as copper, which directly affects circuit reliability, the quality of TGV via metallization, and the lifespan of the package.

[0003] Existing technologies, such as CN118866713A, disclose a system-level carrier packaging process. Although this process uses a glass carrier plate and a transition layer, it suffers from problems in the preparation of the glass substrate transition layer, including insufficient adhesion (generally below 0.6 N / mm), poor deep-hole coverage (lower than 50% coverage of hole bottom in high aspect ratios), complex processes, and environmental unfriendliness. Therefore, there is an urgent need to develop a novel transition layer and its preparation method that combines high adhesion, excellent conformability, simple process, and environmental friendliness. Summary of the Invention

[0004] To solve the above problems, the technical solution adopted in this application is: The first aspect of this application provides a transition layer for a glass-based IC substrate. The transition layer is an organic polymer film deposited on the surface of a glass substrate and the inner wall of a TGV via using plasma chemical vapor deposition. The thickness of the transition layer is 0.1-0.5 μm. The organic polymer film and the glass substrate are bonded together through a dual mechanism of chemical bonding and physical anchoring, which enhances the interfacial adhesion. The bonding strength between the transition layer and the glass substrate is 0.85-1.05 N / mm. The thickness difference between the orifice and the bottom of the TGV via with an aspect ratio of 10:1 is within 10%.

[0005] A second aspect of this application provides a method for preparing a transition layer on a glass-based IC substrate, comprising the following steps: S1: Pretreatment of the glass substrate by cleaning and drying to remove surface contaminants; S2: TGV vias are fabricated on the glass substrate using laser etching, laser-induced denaturation, or photochemical etching methods. S3: Place the glass substrate with completed TGV through-hole processing in a plasma processing chamber and perform surface activation treatment using oxygen, argon, or nitrogen plasma. The processing power is 50-500W, the processing time is 1-10 minutes, the gas flow rate is 10-100sccm, and the chamber pressure is 10-200mTorr, in order to remove residues in the holes, introduce active functional groups, and improve the surface energy of the glass. S4: The glass substrate activated in step S3 is placed in a plasma chemical vapor deposition system. An organic polymer precursor is used to deposit an organic polymer film as a transition layer on the surface of the glass substrate and the inner wall of the TGV via through plasma-assisted polymerization. S5: Anneal the deposited transition layer at a temperature of 100-200℃ for 30-60 minutes to eliminate internal stress and improve film density.

[0006] Preferably, in step S4, the organic polymer is parylene or a derivative thereof, and the deposition process includes: Sublimation stage: The parylene raw material is heated to 130-170℃ in a sublimation furnace, and the pressure is controlled at 0.1-1 Torr, so that it is sublimated into gaseous monomer; Pyrolysis stage: Gaseous monomers are introduced into a pyrolysis furnace and pyrolyzed into active free radical monomers at 650-700℃; Deposition stage: Active monomers are introduced into the deposition chamber, the temperature of the deposition chamber is controlled at 25-40℃, the pressure is controlled at 0.01-0.1 Torr, and the deposition time is 10-20 minutes.

[0007] Preferably, the parylene is selected from one or more combinations of Parylene C, Parylene N, and Parylene D.

[0008] Preferably, in step S3, the plasma surface activation treatment uses oxygen plasma, and after treatment, the contact angle of the glass surface is reduced from the initial 65° to below 12°, and the surface energy is increased from 30-40 mN / m to 60-70 mN / m.

[0009] Preferably, in step S2, the TGV via is fabricated using a combination of laser etching and laser-induced denaturation, with a laser wavelength of 200-1000 nm, a pulse width of 1-100 ns, and a power density of 10. 6 -10 9 W / cm².

[0010] Preferably, in step S4, the organic polymer is polyimide, polybenzoxazole, or benzocyclobutene, and the corresponding precursor gas is used in the deposition process to form a thin film through plasma-enhanced chemical vapor deposition.

[0011] Preferably, the transition layer has a low dielectric constant of 2.6-3.1, low dielectric loss, low internal stress of less than 10 MPa, and good thermal stability, with a thermal decomposition temperature greater than 400°C. It can be removed in one go using the same etching solution as the subsequently deposited copper layer without the need for secondary etching with hydrofluoric acid.

[0012] Preferably, the transition layer forms a continuous and uniform thin film within the TGV via with an aspect ratio of 10:1 or higher, and the thickness difference between the via opening and the bottom is less than 8%. The bonding strength between the transition layer and the glass substrate is 40-70% higher than that of the magnetron sputtered titanium transition layer, and 3-5 times higher than that of direct metallization by chemical copper plating.

[0013] A third aspect of this application provides a glass-based IC substrate comprising the glass-based IC substrate transition layer described above, or the glass-based IC substrate transition layer prepared by the above-described preparation method. The glass substrate is a Corning Eagle XG glass core plate with dimensions of 300mm × 300mm and a thickness of 0.5mm. The TGV vias have a diameter of 30μm, a spacing of 100μm, an aspect ratio of 10:1, and a taper of less than 2°.

[0014] Compared with the prior art, the beneficial effects of this application are as follows: 1. This application achieves a bonding strength of 0.85-1.05 N / mm between the organic polymer transition layer and the glass substrate through the synergistic effect of plasma surface activation and PECVD deposition, which is 40%-5 times higher than the prior art, providing a fundamental guarantee for subsequent fine circuit processing and long-term reliability.

[0015] 2. The conformal properties of the PECVD process in this application enable it to form a continuous and uniform transition layer film in TGV vias with an aspect ratio of 10:1 or higher, with the thickness difference between the via opening and the bottom controlled within 10%, thus solving the industry problem of insufficient coverage in deep holes caused by processes such as magnetron sputtering.

[0016] 3. This application uses a single organic polymer transition layer, which can be etched simultaneously with the copper layer, eliminating the need for secondary etching with hydrofluoric acid and thus eliminating safety hazards; at the same time, it eliminates the need to use toxic and harmful chemicals such as palladium and formaldehyde, significantly reducing the environmental impact. Attached Figure Description

[0017] Figure 1 This is a process flow diagram of the preparation method of this application. Detailed Implementation

[0018] The present application will be further described in detail below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present application. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. All other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present application.

[0019] Example 1 like Figure 1 As shown, this application provides a glass-based IC substrate transition layer and its preparation method, including the following steps: Step S1: Glass substrate pretreatment step Take a glass core plate (Corning Eagle XG) with a size of 300mm×300mm and a thickness of 0.5mm, and ultrasonically clean it in acetone, isopropanol and deionized water for 10 minutes each, then dry it with nitrogen.

[0020] Step S2, TGV through-hole preparation steps TGV through-hole arrays were fabricated using a combination of laser etching and laser-induced denaturation. The laser parameters were: wavelength 532 nm, pulse width 10 ns, and power density 5 × 10⁻⁶. 8 W / cm². The target diameter of the through-holes is 30μm, the spacing is 100μm, and the aspect ratio is 10:1. After fabrication, the taper of the through-holes is <2°, and the hole walls are smooth and crack-free.

[0021] Step S3, Plasma Surface Activation Treatment The glass substrate, after TGV processing, was placed in a plasma treatment chamber for surface treatment using oxygen plasma. The treatment parameters were: RF power 100W, treatment time 5 minutes, oxygen flow rate 80 sccm, and chamber pressure 50 mTorr. After treatment, the contact angle of the glass surface decreased from the initial 65° to 12°, and the surface energy increased from 38 mN / m to 68 mN / m, indicating that active functional groups were successfully introduced into the glass surface, resulting in a significant increase in surface energy.

[0022] Step S4: PECVD deposition of poly(p-xylene) transition layer Deposition of the parylene (P-xylene C) transition layer was performed using a vacuum deposition system. Sublimation stage: The Parylene C dimer raw material is placed in a sublimation furnace, heated to 150°C, and the pressure is controlled at 0.5 Torr, so that it is sublimated into a gaseous monomer; Pyrolysis stage: Gaseous monomers are introduced into a pyrolysis furnace and pyrolyzed into active free radical monomers at 680°C; Deposition stage: Active monomers are introduced into the deposition chamber, the temperature of the deposition chamber is controlled at 30℃, the pressure is controlled at 0.05 Torr, and the deposition time is 14 minutes.

[0023] After deposition, the substrate was allowed to cool naturally to room temperature before being removed. SEM section measurements confirmed a transition layer thickness of 0.23 μm, which was continuous and uniformly distributed on the inner walls and surface of the TGV vias, with a thickness difference of <8% between the via opening and bottom.

[0024] Step S5: Anneal the transition layer. The deposited transition layer is annealed at 100-200℃ for 30-60 minutes to eliminate internal stress and improve film density. Step S6, Metallization and Performance Testing A 0.3 μm copper seed layer was deposited on the transition layer by magnetron sputtering, followed by pattern electroplating to thicken the copper layer to 15 μm, and finally rapid etching to form fine lines.

[0025] The bond strength between the transition layer and the glass substrate was tested using a peel strength tester (ASTM D903 standard), and the result was 0.91 N / mm. This bond strength falls within the range of 0.85-1.05 N / mm defined in this application.

[0026] Example 2 To verify the applicability of different parylene materials, the same process parameters as in Example 1 were used, and Parylene N and Parylene D were deposited as transition layer materials, respectively. The results are as follows: Experimental results show that Parylene C, Parylene N, and Parylene D can all achieve continuous coverage within the TGV pores (>99%), and their peel strength is all greater than 0.78 N / mm. Parylene C exhibits the best bonding strength (0.91 N / mm), followed by Parylene D (0.85 N / mm), with Parylene N being slightly lower (0.78 N / mm). All three materials are parylene materials as defined in this application.

[0027] Example 3 To verify the rationality of the deposition temperature range (25-40℃), the same process as in Example 1 was used to deposit Parylene C transition layers at deposition temperatures of 25℃, 30℃, 40℃, and 50℃. The test results are as follows: Experiments show that when the deposition temperature is within the range of 25-40℃, the film surface is smooth, the internal stress is low (≤12 MPa), and the peel strength is greater than 0.85 N / mm, meeting the adhesion requirements. When the deposition temperature exceeds 40℃, the internal stress of the film increases sharply (reaching 28 MPa at 50℃), the surface exhibits an orange peel effect, and the roughness increases significantly (Ra reaches 12.5 nm at 50℃), resulting in a significant decrease in adhesion to the subsequent copper layer (only 0.62 N / mm at 50℃). Therefore, this application preferably controls the deposition temperature between 25-40℃, as this range can ensure good performance of the transition layer.

[0028] Example 4 To verify the rationality of the deposition pressure range (0.01-0.1 Torr), deposition pressures of 0.01 Torr, 0.05 Torr, 0.10 Torr, and 0.20 Torr were set at a deposition temperature of 30℃, and the results are as follows: Experiments show that when the deposition pressure is in the range of 0.01-0.10 Torr, the TGV pore coverage is good (pore opening to pore bottom thickness ratio ≤ 1.15), and the peel strength is greater than 0.85 N / mm. When the deposition pressure exceeds 0.10 Torr, the mean free path of gas molecules decreases, making it difficult for active free radicals to enter the bottom of the deep pores, resulting in a decrease in pore bottom coverage (pore opening / pore bottom thickness ratio reaches 1.45) and a significant reduction in binding force (only 0.62 N / mm). Therefore, this application preferably controls the deposition pressure between 0.01-0.10 Torr.

[0029] Example 5 To verify the applicability of organic polymer materials (polyimide, polybenzoxazole, and benzocyclobutene), the same process steps as in Example 1 were used, except that the organic polymer precursor in step S4 was replaced with polyimide precursor, polybenzoxazole precursor, and benzocyclobutene precursor, respectively, and a transition layer film was formed by plasma-enhanced chemical vapor deposition.

[0030] Testing showed that the transition layers prepared from the three materials could form a continuous cover within the TGV pores, with peel strengths of 0.72 N / mm, 0.68 N / mm, and 0.75 N / mm, respectively. Although slightly lower than those of parylene, these strengths were still significantly better than the prior art of comparative examples 1-3, and all met the basic requirements for adhesion in subsequent processes. This indicates that the alternative materials can also achieve the technical effects of this application.

[0031] Example 6 Comparative Example 1 A transition layer was prepared on a glass substrate of the same specifications using an existing magnetron sputtering process: first, a titanium layer with a thickness of 0.1 μm was sputtered as a transition layer (DC sputtering, power 1.5 kW, pressure 0.5 Pa); then, a copper seed layer with a thickness of 0.4 μm was sputtered (DC sputtering, power 2.0 kW, pressure 0.5 Pa); the subsequent circuit fabrication steps were the same as in Example 1.

[0032] Test results: Peel strength 0.52 N / mm (below the 0.85-1.05 N / mm range specified in this application); TGV in-hole coverage: complete coverage at the orifice, thickness reduced to 60% of the orifice thickness in the middle, and only 35% of the orifice thickness at the bottom, with multiple discontinuities. This comparative example shows that the magnetron sputtering metal transition layer method cannot achieve high adhesion and uniform in-hole coverage with high aspect ratio.

[0033] Comparative Example 2 A copper layer is directly deposited on a glass substrate of the same specifications using a chemical copper plating process. Pretreatment: hydrofluoric acid roughening (5%, 30 seconds) → sensitization (palladium chloride / stannous chloride, 2 minutes) → activation (hydrochloric acid / palladium chloride, 1 minute); chemical copper deposition: copper sulfate / formaldehyde system, temperature 35℃, time 20 minutes, copper layer thickness approximately 0.5 μm.

[0034] Test results: Peel strength 0.18 N / mm (far below the 0.85-1.05 N / mm range specified in this application); TGV in-hole coverage: uneven deposition, multiple voids, and in-hole coverage <50%. This comparative example shows that the chemical copper plating method has insufficient bonding strength and poor deep-hole coverage.

[0035] Comparative Example 3 A polyimide transition layer was prepared on a glass substrate by spin coating: spin coating parameters: 3000 rpm, 30 seconds; curing process: 150℃ / 30 min + 250℃ / 60 min; deposition thickness approximately 0.3 μm.

[0036] Test results: Peel strength 0.32 N / mm (below the 0.85-1.05 N / mm range specified in this application); TGV orifice coverage: severe buildup at the orifice opening (thickness > 1 μm), no coverage at the orifice bottom. This comparative example demonstrates that organic material coating methods cannot form a continuous and uniform film within high aspect ratio TGV orifices.

[0037] Summary of performance test results in this application embodiment 1) Bonding force analysis The peel strength of each embodiment of this application is 0.78-0.91 N / mm, with the peel strength of Parylene C and Parylene D being 0.91 N / mm and 0.85 N / mm, respectively. This represents a 40-75% improvement compared to Comparative Example 1 (magnetron sputtered titanium transition layer, 0.52 N / mm), a 3-5 times improvement compared to Comparative Example 2 (chemical copper plating direct metallization, 0.18 N / mm), and an approximately 2.8 times improvement compared to Comparative Example 3 (spin-coated polyimide, 0.32 N / mm). This demonstrates the significant improvement in adhesion achieved by this application.

[0038] 2) Deep Hole Covering Capacity Analysis All embodiments of this application achieve full coverage (>99%) within the TGV borehole, with a thickness difference of <8% between the borehole opening and bottom. In contrast, Comparative Example 1 shows a bottom coverage of less than 40% in a high aspect ratio borehole, with a thickness difference of >60% between the borehole opening and bottom; Comparative Example 2 shows a bottom coverage of <60%; and Comparative Example 3 shows no bottom coverage. This demonstrates that this application has a significant advantage in terms of uniform coverage in deep boreholes.

[0039] 3) Process compatibility analysis The transition layers in the embodiments of this application can be removed in one step using a sulfuric acid / hydrogen peroxide etching solution shared with the subsequently deposited copper layer, without the need for secondary etching with hydrofluoric acid. In contrast, Comparative Example 1 requires the use of hydrofluoric acid to etch the titanium layer, which poses a safety hazard.

[0040] 4) Electrical properties and thermal stability analysis The transition layer prepared in Example 1 of this application has a dielectric constant of 2.8, an internal stress of 6 MPa (less than 10 MPa), and a thermal decomposition temperature greater than 400°C, which meets the requirements of each embodiment.

[0041] Of course, the above embodiments are not intended to limit this application, and this application is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of this application should also fall within the protection scope of this application.

Claims

1. A glass-based IC substrate transition layer, characterized in that: The transition layer is an organic polymer film deposited on the surface of the glass substrate and the inner wall of the TGV via using plasma chemical vapor deposition. The thickness of the transition layer is 0.1-0.5 μm. The organic polymer film and the glass substrate are bonded together by a dual mechanism of chemical bonding and physical anchoring, which enhances the interfacial adhesion. The bonding strength between the transition layer and the glass substrate is 0.85-1.05 N / mm. The thickness difference between the orifice and the bottom of the TGV via with an aspect ratio of 10:1 is within 10%.

2. A method for preparing a transition layer on a glass-based IC substrate, characterized in that: Includes the following steps: S1: Pretreatment of the glass substrate by cleaning and drying to remove surface contaminants; S2: TGV vias are fabricated on the glass substrate using laser etching, laser-induced denaturation, or photochemical etching methods. S3: Place the glass substrate with completed TGV through-hole processing in a plasma processing chamber and perform surface activation treatment using oxygen, argon, or nitrogen plasma. The processing power is 50-500W, the processing time is 1-10 minutes, the gas flow rate is 10-100sccm, and the chamber pressure is 10-200mTorr, in order to remove residues in the holes, introduce active functional groups, and improve the surface energy of the glass. S4: The glass substrate activated in step S3 is placed in a plasma chemical vapor deposition system. An organic polymer precursor is used to deposit an organic polymer film as a transition layer on the surface of the glass substrate and the inner wall of the TGV via through plasma-assisted polymerization. S5: Anneal the deposited transition layer at a temperature of 100-200℃ for 30-60 minutes to eliminate internal stress and improve film density.

3. The method for preparing a glass-based IC substrate transition layer according to claim 2, characterized in that: In step S4, the organic polymer is poly(p-xylene) or its derivatives, and the deposition process includes: Sublimation stage: The parylene raw material is heated to 130-170℃ in a sublimation furnace, and the pressure is controlled at 0.1-1 Torr, so that it is sublimated into gaseous monomer; Pyrolysis stage: Gaseous monomers are introduced into a pyrolysis furnace and pyrolyzed into active free radical monomers at 650-700℃; Deposition stage: Active monomers are introduced into the deposition chamber, the temperature of the deposition chamber is controlled at 25-40℃, the pressure is controlled at 0.01-0.1 Torr, and the deposition time is 10-20 minutes.

4. The method for preparing a glass-based IC substrate transition layer according to claim 3, characterized in that: The parylene is selected from one or more combinations of Parylene C, Parylene N, and Parylene D.

5. The method for preparing a glass-based IC substrate transition layer according to claim 2, characterized in that: In step S3, the plasma surface activation treatment uses oxygen plasma. After treatment, the contact angle of the glass surface is reduced from the initial 65° to below 12°, and the surface energy is increased from 30-40 mN / m to 60-70 mN / m.

6. The glass-based IC substrate transition layer according to claim 2, characterized in that: In step S2, TGV vias are fabricated using a combination of laser etching and laser-induced denaturation. The laser wavelength is 200-1000 nm, the pulse width is 1-100 ns, and the power density is 10. 6 -10 9 W / cm².

7. The method for preparing a glass-based IC substrate transition layer according to claim 2, characterized in that: In step S4, the organic polymer is polyimide, polybenzoxazole, or benzocyclobutene, and the corresponding precursor gas is used in the deposition process to form a thin film through plasma-enhanced chemical vapor deposition.

8. A method for preparing a glass-based IC substrate transition layer according to any one of claims 2-7, characterized in that: The transition layer has a low dielectric constant of 2.6-3.1, low dielectric loss, low internal stress of less than 10 MPa, and good thermal stability. Its thermal decomposition temperature is greater than 400℃. It can be removed in one go with the subsequently deposited copper layer using the same etching solution, without the need for secondary etching with hydrofluoric acid.

9. A method for preparing a glass-based IC substrate transition layer according to any one of claims 2-7, characterized in that: The transition layer forms a continuous and uniform thin film within the TGV via with an aspect ratio of 10:1 or higher, with a thickness difference of less than 8% between the via opening and the bottom. The bonding strength between the transition layer and the glass substrate is 40-70% higher than that of the magnetron sputtered titanium transition layer, and 3-5 times higher than that of direct metallization by chemical copper plating.

10. A glass-based IC substrate, characterized in that: The invention comprises a glass substrate IC carrier transition layer as described in claim 1, or a glass substrate IC carrier transition layer prepared by the preparation method described in claim 9, wherein the glass substrate has a size of 300mm × 300mm and a thickness of 0.5mm, the TGV via diameter is 30μm, the spacing is 100μm, the aspect ratio is 10:1, and the via taper is less than 2°.

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