Conductive structure comprising phosphorus copper alloy and method for preparing the conductive structure

Abstract

The present disclosure provides a multi-layer wiring structure comprising a plurality of dielectric layers and a plurality of conductive wiring layers interlaced with the dielectric layers, wherein the conductive wiring layers comprise a phosphorus copper alloy (eg, Cu 3 P).

Description

Technical Field

[0001] Embodiments of the present invention relate to a conductive structure comprising a phosphorus copper alloy and a method for preparing the conductive structure. Background Art

[0002] The integrated circuit (IC) industry has experienced exponential growth. Technological advances in IC materials and design have produced successive generations of ICs, each with smaller and more complex circuits than the previous one. Over the course of IC evolution, functional density (the number of interconnected components per unit chip area) has generally increased, while geometry (the smallest component or line that can be produced using a single process) has decreased. The advantage of this scaling process is generally improved manufacturing efficiency. However, this scaling process also increases the complexity of IC processing and manufacturing. Furthering these advances requires improvements in IC wiring geometry, materials, processing, and manufacturing. Summary of the Invention

[0003] Certain embodiments of the present disclosure propose a multi-layer wiring structure comprising a plurality of dielectric layers and a plurality of conductive wiring layers interlaced with the dielectric layers, wherein the conductive wiring layers comprise a phosphor-copper alloy. Regarding the wiring geometry, a zigzag design and fabrication method are proposed to reduce the skin depth effect during high-frequency operation, thereby increasing the surface area for current flow and boosting the operating frequency when transmitting high-frequency signals.

[0004] Certain embodiments of the present disclosure provide an interconnect package structure including a substrate and a conductive pad located on the substrate, wherein the conductive pad includes a phosphor-copper alloy.

[0005] Certain embodiments of the present disclosure provide a method for forming a wiring structure, comprising: forming a phosphorus-copper alloy layer on a loading plate by performing an electroplating operation, and forming a dielectric layer on the patterned phosphorus-copper alloy layer, wherein the electroplating solution for forming the patterned phosphorus-copper alloy layer contains a copper source and a phosphorus source. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The various aspects of the present disclosure are best understood when reading the following detailed description and the accompanying drawings. It should be noted that, in accordance with standard manufacturing practices in the art, the various features in the drawings are not drawn to scale. In fact, the dimensions of certain features may be intentionally exaggerated or reduced for clarity of description.

[0007] Figure 1 A schematic diagram illustrating an electroless plating system according to certain embodiments of the present disclosure is provided;

[0008] Figure 2A schematic diagram illustrating an electroplating system according to certain embodiments of the present disclosure is provided;

[0009] Figure 3A A perspective view of a wiring substrate is shown to illustrate certain embodiments of the present disclosure;

[0010] Figure 3B A perspective view of a wiring substrate is shown to illustrate certain embodiments of the present disclosure;

[0011] Figures 4A to 4E A cross-sectional view of a wiring substrate at an intermediate stage of a manufacturing process is shown in accordance with certain embodiments of the present disclosure;

[0012] Figures 5A to 5H A cross-sectional view of an interconnect package structure at an intermediate stage of a manufacturing process is shown in accordance with certain embodiments of the present disclosure;

[0013] Figures 6A to 6C A cross-sectional view of a multi-layer wiring structure at an intermediate stage of a manufacturing process is shown in accordance with certain embodiments of the present disclosure;

[0014] Figure 6D A cross-sectional view of a multi-layer wiring structure at an intermediate stage of a manufacturing process is shown in accordance with certain embodiments of the present disclosure;

[0015] Figure 6D 'Describes some embodiments of the present disclosure, Figure 6D A partially enlarged partial icon of a multi-layer wiring structure;

[0016] Figure 6D Some embodiments of the present disclosure are shown. Figure 6D A partially enlarged partial icon of a multi-layer wiring structure;

[0017] Figures 7A to 7H Certain embodiments of the present invention are disclosed. Figure 6D A cross-sectional view of a multi-layer wiring structure at an intermediate stage of process operation. DETAILED DESCRIPTION

[0018] [Cross-reference to related applications]

[0019] This application claims priority from U.S. non-provisional patent application No. 17 / 697,937, filed on March 18, 2022, entitled “Conductive Structure Including Copper-Phosphorous Alloy and AMethod of Manufacturing Conductive Structure,” the entire contents of which are incorporated herein by reference.

[0020] The following disclosure provides a variety of embodiments or illustrations that can be used to implement different features of the present disclosure. The specific examples of components and configurations described below are intended to simplify the present disclosure. As can be imagined, these descriptions are merely illustrative and are not intended to limit the present disclosure. For example, in the following detailed description, a first feature formed above or on a second feature may include an embodiment in which the first and second features are formed in direct contact, and may also include an embodiment in which an additional feature can be formed between the first and second features so that the first and second features are not in direct contact. In addition, the present disclosure may reuse component symbols and / or labels in multiple embodiments. Such repetition is for the purpose of brevity and clarity and does not in itself represent a relationship between the different embodiments and / or configurations discussed.

[0021] Additionally, spatially relative terms (e.g., "beneath," "below," "lower," "above," "upper," and the like) are used herein to facilitate describing the relative relationship of one component or feature to another component or feature depicted in the figures. These spatially relative terms are intended to encompass orientations of the device in use or operation other than the orientation depicted in the figures. The device may be positioned in other orientations (rotated 90 degrees or at other orientations), and the spatially relative descriptors used herein interpreted accordingly.

[0022] Although the numerical ranges and parameters used to define the broader scope of the present invention are approximate, the numerical values ​​in the specific examples are presented herein as precisely as possible. However, any numerical value inherently and inevitably contains standard deviations due to the individual testing methods. As used herein, the terms "substantially," "approximately," or "about" generally refer to values ​​or ranges that are within the range understood by one of ordinary skill in the art to which the invention pertains. Alternatively, the terms "substantially," "approximately," or "about" mean that the actual value falls within the standard deviation understood by one of ordinary skill in the art to which the invention pertains. As one of ordinary skill in the art will appreciate, acceptable standard deviations vary across different art fields. Except in the operating examples, or unless expressly stated otherwise, all ranges, amounts, values, and percentages used herein (e.g., to describe material amounts, time durations, temperatures, operating conditions, quantitative ratios, and the like) are qualified by the terms "substantially," "approximately," or "about." Therefore, unless otherwise indicated to the contrary, the numerical parameters disclosed in this disclosure and the accompanying claims are approximate and are subject to change as needed. At least these numerical parameters should be understood as the number of significant digits indicated and the values ​​obtained by applying the general numeric system. Herein, the numerical range is expressed from one end point to another end point or between two end points; unless otherwise specified, the numerical ranges described herein include the end points.

[0023] Copper sputtering, a traditional method commonly used to manufacture semiconductor components or printed circuit boards (PCBs), often faces defects in advanced technology nodes. For example, particularly when manufacturing high-aspect-ratio vias, the deposited material can build up and stick to the openings of the grooves, forming voids in the via and leading to reliability issues.

[0024] The present disclosure proposes to use phosphor copper alloys, such as copper (I) phosphide, in semiconductor devices, integrated circuit substrates, and printed circuit boards to address the above issues. The copper (I) phosphide of the present disclosure may include a non-stoichiometric compound Cu 3-x P, where in some embodiments, x may be less than approximately 0.1, resulting in copper-deficient cuprous phosphide. In other words, the phosphorus content of the cuprous phosphide ranges from approximately 13.98% to approximately 14.39%. This disclosure also provides novel semiconductor device and printed circuit board (PCB) structures to enhance device performance, such as reducing impedance and improving reliability. This disclosure also provides processes for fabricating semiconductor devices, integrated circuit substrates, and printed circuit boards (PCBs), wherein the method for forming the phosphorus-copper alloy is well compatible with these processes.

[0025] Compared to the sputtered copper layer in the comparative example, the phosphor-copper alloy layer exhibits superior properties in terms of corrosion resistance, wear resistance, wettability, structural density, strength, toughness, conformality, and processability. In particular, the phosphor-copper alloy exhibits superior strength and toughness, enabling separation of the copper layer from low-k materials or insulators. These properties make the phosphor-copper alloy an excellent candidate for incorporation into damascene, dual-damascene processes, or other operations suitable for forming interconnect structures. Furthermore, the structure and adhesion of the phosphor-copper alloy mitigate issues associated with copper layer delamination during chemical mechanical planarization (CMP) during damascene, dual-damascene processes, or other operations suitable for forming interconnect structures. Furthermore, a phosphor-copper alloy (e.g., Cu3P) can be formed as a capping layer on the planarized copper surface to prevent copper diffusion into the overlying interlayer dielectric layer. In conventional comparative examples, the production of the phosphor-copper alloy requires high-temperature annealing. For example, the copper and phosphorus are heated to a temperature range of approximately 900°C to approximately 1000°C. However, such an operation may be incompatible with the manufacturing operations of ICs, PCBs, and IC carriers, because the performance of some components may be impaired by high-temperature annealing. In contrast, the electroless plating operation or electroplating operation described in the present disclosure can be performed at a lower temperature (e.g., below 60°C), thereby avoiding the problems caused by high-temperature annealing. Phosphorus can be used as a deoxidizer and wetting agent for copper. For example, by forming a thin phosphor-copper alloy (e.g., Cu3P) before electroplating copper, the problem of oxidation of the copper layer on the surface of adjacent components (e.g., printed circuit boards, integrated circuits, integrated circuit carriers, or similar) due to exposure to the environment can be alleviated. In particular, the oxygen in the environment reacts with copper to produce copper oxide, which in turn leads to the problem of increased resistance. Therefore, in the process of forming a sputtered copper layer using conventional technology, nitrogen is required to reduce oxidation, but this may result in higher production costs. Especially in advanced process technology applications (such as 5G and 6G mobile networks, and artificial intelligence), resistance becomes a significant issue due to the skin depth effect, whereby electrons may accumulate on the surface of conductive wiring (especially when transmitting high-frequency signals), increasing resistance and reducing component performance. When copper oxide forms on the wiring surface, component performance can be further reduced. Furthermore, the electrical and thermal conductivity of certain phosphor-copper alloys are comparable to those of sputtered copper, with sputtered copper exhibiting a resistivity of only approximately 1.84 μΩ·cm and a thermal conductivity of approximately 381 W / (m·K). Furthermore, the reliability advantage of phosphor-copper alloys over sputtered copper is particularly evident in extreme environments, such as those exposed to non-oxidizing acids (such as HCl and H2SO4), alkaline solutions, organic acids (such as acetic acid and citric acid), seawater, saline solutions, and in air.

[0026] In addition, phosphor copper alloys (such as Cu3P) can also be used as wetting layers during electroplating or electroless plating of copper layers, which can alleviate void problems and improve the conformality of copper layers in high aspect ratio vias (such as conductive vias, blind vias, buried vias, etc.), especially when forming copper layers during electroplating operations. Therefore, in some applications such as printed circuit boards, integrated circuits, integrated circuit carriers, etc., phosphor copper alloys (such as Cu3P with a thickness of about 1 μm to about 3 μm) can replace sputtered copper wetting layers. In certain embodiments, when the concentration of phosphorus in the solution is higher than a specific amount, phosphorus in the form of needle-shaped crystals can be formed, and is therefore suitable for catalyzing and promoting the formation of copper. In addition, phosphorus-copper alloys (such as Cu3P or alloys containing Cu3P) can also be used as heat dissipation materials. Compared with cobalt (Co) and ruthenium (Ru), the phosphor copper alloys disclosed herein provide better copper compatibility. Specifically, a rough film with low conductivity forms between the sputtered copper and cobalt, another diffusion barrier material. Galvanic corrosion occurs at the interface between the copper and cobalt, resulting in material loss of the cobalt. In the example of ruthenium, another diffusion barrier material, ruthenium lacks conformality and wettability compared to the phosphorus copper alloy discussed in this disclosure.

[0027] The above advantages of phosphor copper alloys (especially Cu3P) provide better overall component performance, and this high compatibility in semiconductor device, IC and PCB manufacturing operations enables more changes to the configuration of the conductive structure, thereby further improving component performance. In some cases, sputtered copper lacks conformality and processability, thereby limiting the potential for improving the aspect ratio of the conductive path and changing the configuration of the conductive component to reduce resistance. The disclosure uses electroplating operations to form wetting materials to enhance conformality and processability and solve problems related to the aspect ratio and resistance of the copper process. For example, phosphor copper alloys (especially Cu3P), or other suitable materials (such as copper), can be formed as wetting materials by electroplating operations or electroless plating. In addition, the present invention provides a method for integrating phosphor copper alloys into the steps of manufacturing semiconductor components, ICs and PCBs, which may include electroless plating operations and / or electroplating operations.

[0028] In some embodiments, a phosphor copper film (which may include Cu3P) or a copper film may be formed using electroless plating or electroplating technology. Electroless plating (also known as chemical plating, or autocatalytic plating) is a technology that forms a metal or metal-containing alloy coating on various materials by autocatalytic chemical reduction of metal cations in a chemical liquid bath. The method is to immerse the workpiece to be plated in a reducing agent. When the reducing agent is catalyzed by certain materials, the metal ions become metal and form a coating on the surface of the workpiece. In general, the advantages of electroless plating technology include compatibility and product quality. In some cases, electroless plating technology can be applied to conductive workpieces and non-conductive workpieces, and can also be applied to workpieces of smaller size or smaller surface area. In addition, compared with electroplating technology, the coating formed by electroless plating technology can exhibit better corrosion resistance and / or higher wear resistance.

[0029] In contrast, electroplating technology uses externally generated electric current to form a metal coating on the surface of various materials. The advantages of electroplating technology include high efficiency and high production volume.

[0030] Reference Figure 1 , Figure 1A schematic diagram illustrates an electroless plating system according to certain embodiments of the present disclosure. Electroless plating system 100 includes a processing chamber 101, a phosphorus-based chemical source 111, and a copper-based chemical source 121. The phosphorus-based chemical source 111 is configured to supply a phosphorus-based chemical to a plating solution in processing chamber 101 via a first conduit 112, while the copper-based chemical source 121 is configured to supply a copper-based chemical to the plating solution in processing chamber 101 via a second conduit 122. In this embodiment, the phosphorus-based chemical and the copper-based chemical may be in liquid or gaseous form. In certain embodiments, the first conduit 112 and the second conduit 122 may be made of a material that is substantially non-reactive with the phosphorus-based chemical or the copper-based chemical, such as polytetrafluoroethylene (PTFE), vinyl polymers, polypropylene (PP), polyvinyl chloride (PVC), polyvinylidene difluoride (PVDF), stainless steel, or other suitable conduit materials. In certain embodiments, during an electroless plating operation, a workpiece to be plated may be placed in a plating solution within a processing chamber 101. In certain embodiments, the chemical reactions occurring within the processing chamber 101 depend on the composition of the plating solution and the operating conditions of the plating solution. In particular, the reaction products of the electroless plating may be related to the concentration of the phosphorus-based chemical in the plating solution. Therefore, in certain embodiments, the electroless plating system 100 further includes a first mass flow controller 113 attached to the first conduit 112 and a second mass flow controller 123 attached to the second conduit 122, thereby respectively adjusting the phosphorus-based chemical and copper-based chemical supplied to the processing chamber 101. In certain embodiments, the electroless plating system 100 further includes a controller 131 for controlling the conditions of the processing chamber 101, such as adjusting the temperature of the plating solution. The controller 131 may include a heater and / or a cooler. In certain embodiments, the controller 131 may further include one or more sensors to detect the state of the plating solution, such as the composition of the plating solution, to further adjust the state of the plating solution.

[0031] In certain embodiments, the phosphorus-based chemical may be one of the following: phosphine (PH3), phosphorus oxychloride (POCl3), or phosphorus trichloride (PCl3). In certain embodiments, the copper-based chemical may be one of the following: copper (II) sulfate (CuSO4), or copper (II) pyrophosphate (Cu2P2O7). In certain embodiments, under certain conditions, PH3 (whether liquid or gaseous) may further migrate to a position adjacent to the bottom of the conductive path and may generate hydrogen ions (H +), which reacts with copper oxide (typically formed on copper surfaces exposed to oxygen) and produces dissipative water vapor. This property can increase the purity of the copper in the conductive path. In some alternative embodiments, copper (II) phosphate (Cu3(PO4)2) can also be used as the copper-based chemical. In some embodiments, the electroplating solution is substantially free of cyanide. In some embodiments, the copper (II) phosphate solution (Cu3(PO4)2) and the copper (II) pyrophosphate solution (Cu2P2O7) can be alkaline solutions, which may have a pH greater than 7. In some cases, the use of alkaline chemicals during manufacturing operations can alleviate material loss issues, especially in barrier layers in the workpiece, such as tantalum nitride layers (TaN) or cobalt layers. For example, when tantalum nitride is oxidized, tantalum oxide is formed, which can further lead to reliability issues.

[0032] The electroplating solution includes metal ions (e.g., Cu 2+ In some embodiments, the electroplating solution further includes a complexing agent that can bind the above metal ions (such as Cu 2+ ), thereby forming a coordination complex. In some embodiments, the electroplating solution further includes a buffer, which can be used to adjust or balance the pH value (i.e., acidity / alkalinity) of the electroplating solution. In some embodiments, the electroplating solution further includes an active agent such as chloride ions (Cl - ), wherein chloride ions can also be used as anode active agents. In some embodiments, the electroplating solution further includes other additives, such as chloride ions (Cl - ) can be used as a brightener, grain refiner, leveler, wetting agent, stress reliever, or inhibitor. For example, polyethylene glycol (PEG) reacts with metal ions (or, in some cases, phosphate ions) to form a coordination complex, thereby adjusting the electroplating reaction rate (e.g., slowing it down). Furthermore, PEG can increase wettability, thereby improving the results of the forming step.

[0033] In some embodiments, the electroplating solution further includes a reducing agent, thereby converting ions in the electroplating solution into a coating material (eg, copper (Cu) or a phosphorus copper alloy, such as Cu 3 P).

[0034] Electroless plating for coating copper on a workpiece may utilize a plating solution comprising a phosphorus-based chemical and a copper-based chemical. The results of the electroless plating operation may depend on operating conditions such as the concentration of the specific chemical and the operating temperature.

[0035] Embodiment 1 of the electroplating solution for electroless plating includes CuSO4·5H2O and PH3, which can be used to form a Cu3P coating (as shown in Table 1-1 and Chemical Reaction Formula 1-1) and a Cu coating (as shown in Table 1-2 and Chemical Reaction Formula 1-2). Electroplating results can vary under different operating conditions and with different plating solution compositions.

[0036] Table 1-1

[0037]

[0038] For example, the electroplating solution used to form a Cu3P coating may include: CuSO4·5H2O at a concentration of 85 g / L, PH3 at a concentration of 6.89 g / L, and chloride ions at a concentration of approximately 55 PPM (which may include the additional additives described above). The pH of the electroplating solution may be approximately 8.7, the temperature of the electroplating solution may be approximately 55° C., and during the electroless plating operation, a copper-based chemical (CuSO4·5H2O) may be provided in the electroplating solution to maintain its concentration.

[0039] Table 1-2

[0040]

[0041] For example, an electroplating solution for forming a Cu coating may include 85 g / L of CuSO4.5H2O, 2.312 g / L of PH3, and approximately 55 PPM of chloride ions (which may include the additional additives described above). The pH of the electroplating solution may be approximately 8.7, and the temperature of the electroplating solution may be approximately 25° C. During the electroless plating operation, a copper-based chemical (CuSO4.5H2O) may be provided in the electroplating solution to maintain its concentration and electrical properties.

[0042] With reference to Tables 1-1 and 1-2, in certain embodiments, the concentration of pH3 in the electroplating solution used to form a Cu3P coating is higher than the concentration of pH3 in the electroplating solution used to form a Cu coating. In certain embodiments, the operating temperature of the electroplating solution used to form a Cu3P coating is higher than the operating temperature of the electroplating solution used to form a Cu coating. Because the temperature and composition of the electroplating solution containing CuSO4·5H2O and pH3 affect the type of reaction that occurs, the temperature and composition of the electroplating solution can be controlled to achieve the desired results.

[0043] For example, in order to form a Cu3P layer (which can be a wetting layer and a deoxidation layer) on a workpiece, the controller 131 (e.g. Figure 1The controller 131 can control the temperature of the electroplating solution to about 50°C to about 60°C, and the first mass flow controller 113 and the second mass flow controller 123 can control the inflow of phosphorus-based chemicals and copper-based chemicals, thereby controlling the concentration of pH3 to about 5.3 g / L to about 10.6 g / L. The first mass flow controller 113 and the second mass flow controller 123 can also control the concentration of CuSO4·5H2O in the electroplating solution. When the Cu layer is to be formed next, the controller 131 can control the temperature of the electroplating solution to about 20°C to about 30°C, and the first mass flow controller 113 and the second mass flow controller 123 can control the concentration of pH3 in the electroplating solution composition to about 1.734 g / L to about 2.89 g / L.

[0044] It will be appreciated that other variables may affect the product outcome of an electroless plating operation, and therefore the above ranges may be adjusted accordingly. Furthermore, the above supply and control mechanisms may also be applied to the following electroplating solution embodiments. For the sake of brevity, repetitive descriptions will not be repeated.

[0045] Embodiment 2 of the electroplating solution for electroless plating includes CuSO4·5H2O and phosphorus oxychloride (POCl3). This electroplating solution can be used to form a Cu3P coating (as shown in Table 2-1 and Chemical Reaction Formula 2-1) and a Cu coating (as shown in Table 2-2 and Chemical Reaction Formula 2-2). In other words, electroplating results can vary under different operating conditions and different electroplating solution compositions.

[0046] Table 2-1

[0047]

[0048]

[0049] For example, the electroplating solution used to form the Cu3P coating may include: CuSO4·5H2O at a concentration of 85 g / L, POCl3 at a concentration of 45.182 g / L, and chloride ions at a concentration of approximately 55 PPM (which may include the additional additives described above). The pH of the electroplating solution may be approximately 8.7, the temperature of the electroplating solution may be approximately 55° C., and during the electroless plating operation, a copper-based chemical (CuSO4·5H2O) may be provided in the electroplating solution to maintain its concentration.

[0050] Table 2-2

[0051]

[0052] For example, an electroplating solution for forming a Cu coating may include 85 g / L of CuSO4.5H2O, 34.755 g / L of POCl3, and approximately 55 PPM of chloride ions (which may include the additional additives described above). The pH of the electroplating solution may be approximately 8.7, the temperature of the electroplating solution may be approximately 25° C., and during the electroless plating operation, a copper-based chemical (CuSO4.5H2O) may be provided in the electroplating solution to maintain its concentration and electrical properties.

[0053] With reference to Tables 2-1 and 2-2, in some embodiments, the POCl3 concentration in the electroplating solution used to form the Cu3P coating is higher than the POCl3 concentration in the electroplating solution used to form the Cu coating. In some embodiments, the operating temperature of the electroplating solution used to form the Cu3P coating is higher than the operating temperature of the electroplating solution used to form the Cu coating. Because the temperature and the composition of the electroplating solution containing CuSO4·5H2O and POCl3 affect the type of reaction that occurs, the temperature and composition of the electroplating solution can be controlled using controller 131 and first mass flow controller 113 / second mass flow controller 123, respectively, to achieve the desired results.

[0054] In certain embodiments, when forming a Cu3P coating using a plating solution comprising CuSO4·5H2O and POCl3 during an electroless plating operation, hydrochloric acid (HCl) may be generated (as shown in Chemical Formula 2-1). Hydrochloric acid (HCl) can act as an activator on the workpiece surface, thereby improving the brightness and reliability of the Cu3P coating.

[0055] In certain embodiments, when a Cu coating is formed using a plating solution comprising CuSO4·5H2O and POCl3 during an electroless plating operation, chlorine (Cl2) may be generated (as shown in Chemical Formula 2-2). Chlorine (Cl2) can act as an activator on the workpiece surface, thereby improving the brightness and reliability of the Cu coating.

[0056] Embodiment 3 of the electroplating solution for electroless plating includes CuSO4·5H2O and phosphorus trichloride (PCl3). This electroplating solution can be used to form a Cu3P coating (as shown in Table 3-1 and Chemical Reaction Formula 3-1) and a Cu coating (as shown in Table 3-2 and Chemical Reaction Formula 3-2). In other words, electroplating results can vary under different operating conditions and different electroplating solution compositions.

[0057] Table 3-1

[0058]

[0059]

[0060] For example, the electroplating solution used to form the Cu3P coating may include: CuSO4·5H2O at a concentration of 85 g / L, PCl3 at a concentration of 60.7 g / L, and chloride ions at a concentration of approximately 55 PPM (which may include the additional additives described above). The pH of the electroplating solution may be approximately 8.7, the temperature of the electroplating solution may be approximately 55° C., and during the electroless plating operation, a copper-based chemical (CuSO4·5H2O) may be provided in the electroplating solution to maintain its concentration.

[0061] Table 3-2

[0062]

[0063] For example, the electroplating solution used to form the Cu coating may include: CuSO4·5H2O at a concentration of 85 g / L, PCl3 at a concentration of 37.354 g / L, and chloride ions at a concentration of approximately 55 PPM (which may include the additional additives described above). The pH of the electroplating solution may be approximately 8.7, and the temperature of the electroplating solution may be approximately 25° C. During the electroless plating operation, a copper-based chemical (CuSO4·5H2O) may be provided in the electroplating solution to maintain its concentration and electrical properties.

[0064] Referring to Tables 3-1 and 3-2, in some embodiments, the PCl3 concentration in the electroplating solution used to form the Cu3P coating is higher than the PCl3 concentration in the electroplating solution used to form the Cu coating. In some embodiments, the operating temperature of the electroplating solution used to form the Cu3P coating is higher than the operating temperature of the electroplating solution used to form the Cu coating. Because the temperature and the composition of the electroplating solution containing CuSO4·5H2O and PCl3 can affect the type of reaction that occurs, the temperature and composition of the electroplating solution can be controlled using controller 131 and first mass flow controller 113 / second mass flow controller 123, respectively, to achieve the desired results.

[0065] In certain embodiments, when a Cu3P coating and a Cu coating are formed using a plating solution comprising CuSO4·5H2O and PCl3 in an electroless plating operation, hydrochloric acid (HCl) and chlorine (Cl2) may be generated (as shown in Chemical Formulas 3-1 and 3-2). In certain embodiments, the chloride ions may act as an anode active agent, thereby improving the brightness and reliability of the Cu3P coating and the Cu coating.

[0066] Embodiment 4 of the electroplating solution for electroless plating includes Cu2P2O7·3H2O and gaseous PH3. This electroplating solution can be used to form a Cu3P coating (as shown in Table 4-1 and Chemical Reaction Formula 4-1) and a Cu coating (as shown in Table 4-2 and Chemical Reaction Formula 4-2). In other words, electroplating results may vary under different operating conditions and different electroplating solution compositions.

[0067] Table 4-1

[0068]

[0069]

[0070] For example, the electroplating solution used to form a Cu3P coating may include: 85 g / L of Cu2P2O7·3H2O, 310 g / L of K4P2O7, 12.48 g / L of PH3, and approximately 3 mL / L of ammonium hydroxide solution (e.g., 28% ammonia solution). The pH of the electroplating solution may be approximately 8.7, and the temperature of the electroplating solution may be approximately 57°C. K4P2O7 provides phosphorus ions in the electroplating solution, which improves loading capacity and buffers variations in the pH of the electroplating solution, thereby stabilizing the pH of the electroplating solution.

[0071] Table 4-2

[0072]

[0073] For example, the electroplating solution used to form the Cu coating may include: 85 g / L of Cu2P2O7·3H2O, 310 g / L of K4P2O7, 5.76 g / L of PH3, and approximately 3 mL / L of ammonium hydroxide solution (e.g., 28% ammonia solution). The pH of the electroplating solution may be approximately 8.7, and the temperature of the electroplating solution may be approximately 27°C. K4P2O7 can provide phosphorus ions in the electroplating solution, which can improve the load capacity and buffer the pH variation of the electroplating solution, thereby stabilizing the pH of the electroplating solution.

[0074] With reference to Tables 4-1 and 4-2, in some embodiments, the concentration of pH3 in the electroplating solution used to form the Cu3P coating is higher than the concentration of pH3 in the electroplating solution used to form the Cu coating. In some embodiments, the operating temperature of the electroplating solution used to form the Cu3P coating is higher than the operating temperature of the electroplating solution used to form the Cu coating. Because the temperature and the composition of the electroplating solution containing Cu2P2O7·3H2O and pH3 affect the type of reaction that occurs, the temperature and composition of the electroplating solution can be controlled using controller 131 and first mass flow controller 113 / second mass flow controller 123, respectively, to achieve the desired results.

[0075] In certain embodiments, when a Cu3P coating and a Cu coating are formed using a plating solution comprising Cu2P2O7·3H2O and PH3 in an electroless plating operation, hydrogen (H2) may be generated (as shown in Chemical Formulas 4-1 and 4-2). In certain embodiments, hydrogen can slow down the oxidation of copper because it reacts with oxygen ions, thereby improving the coating operation and the quality and reliability of the resulting product.

[0076] Embodiment 5 of the electroplating solution for electroless plating includes Cu2P2O7·3H2O and gaseous POCl3. This electroplating solution can be used to form a Cu3P coating (as shown in Table 5-1 and Chemical Reaction Formula 5-1) and a Cu coating (as shown in Table 5-2 and Chemical Reaction Formula 5-2). In other words, electroplating results can vary under different operating conditions and with different electroplating solution compositions.

[0077] Table 5-1

[0078]

[0079]

[0080] For example, the electroplating solution used to form the Cu3P coating may include: 85 g / L of Cu2P2O7·3H2O, 310 g / L of K4P2O7, 131.326 g / L of POCl3, and approximately 3 mL / L of ammonium hydroxide solution (e.g., 28% ammonia solution). The pH of the electroplating solution may be approximately 8.7, and the temperature of the electroplating solution may be approximately 57°C. K4P2O7 can provide phosphorus ions in the electroplating solution, which can improve the loading capacity and buffer the pH variation of the electroplating solution, thereby stabilizing the pH of the electroplating solution.

[0081] Table 5-2

[0082]

[0083] For example, the electroplating solution used to form the Cu coating may include: Cu2P2O7·3H2O at a concentration of 85 g / L, K4P2O7 at a concentration of 310 g / L, POCl3 at a concentration of 37.354 g / L, and an ammonium hydroxide solution (e.g., a 28% ammonia solution) at a concentration of approximately 3 mL / L. The pH of the electroplating solution may be approximately 8.7, and the temperature of the electroplating solution may be approximately 27° C. K4P2O7 can provide phosphorus ions in the electroplating solution, which can improve the load capacity and buffer the pH variation of the electroplating solution, thereby stabilizing the pH of the electroplating solution.

[0084] With reference to Tables 5-1 and 5-2, in some embodiments, the POCl3 concentration in the electroplating solution used to form the Cu3P coating is higher than the POCl3 concentration in the electroplating solution used to form the Cu coating. In some embodiments, the operating temperature of the electroplating solution used to form the Cu3P coating is higher than the operating temperature of the electroplating solution used to form the Cu coating. Because the temperature and the composition of the electroplating solution containing Cu2P2O7·3H2O and POCl3 affect the type of reaction that occurs, the controller 131 and the first mass flow controller 113 / the second mass flow controller 123 can be used to control the temperature and composition of the electroplating solution to achieve the desired results.

[0085] In certain embodiments, when a Cu3P coating is formed in an electroless plating process using a plating solution comprising Cu2P2O7·3H2O and POCl3, hydrochloric acid (HCl) and chlorine (Cl2) may be generated (as shown in Chemical Formula 5-1). Hydrochloric acid (HCl) and chlorine (Cl2) may enhance the brightness and reliability of the Cu3P coating.

[0086] In some embodiments, when forming a Cu coating using a plating solution comprising Cu2P2O7·3H2O and POCl3 in an electroless plating operation, hydrochloric acid (HCl) may be generated (as shown in Chemical Formula 5-2). Hydrochloric acid (HCl) can improve the brightness and reliability of the Cu coating.

[0087] Embodiment 6 of the electroplating solution for electroless plating includes Cu2P2O7·3H2O and gaseous PCl3. This electroplating solution can be used to form a Cu3P coating (as shown in Table 6-1 and Chemical Reaction Formula 6-1) and a Cu coating (as shown in Table 6-2 and Chemical Reaction Formula 6-2). In other words, electroplating results can vary under different operating conditions and with different electroplating solution compositions.

[0088] Table 6-1

[0089]

[0090]

[0091] For example, the electroplating solution used to form the Cu3P coating may include: 85 g / L of Cu2P2O7·3H2O, 310 g / L of K4P2O7, 33.612 g / L of PCl3, and approximately 3 mL / L of ammonium hydroxide solution (e.g., 28% ammonia solution). The pH of the electroplating solution may be approximately 8.7, and the temperature of the electroplating solution may be approximately 57°C. K4P2O7 can provide phosphorus ions in the electroplating solution, which can improve the loading capacity and buffer the pH variation of the electroplating solution, thereby stabilizing the pH of the electroplating solution.

[0092] Table 6-2

[0093]

[0094]

[0095] For example, the electroplating solution used to form the Cu coating may include: Cu2P2O7·3H2O at a concentration of 85 g / L, K4P2O7 at a concentration of 310 g / L, PCl3 at a concentration of 37.354 g / L, and an ammonium hydroxide solution (e.g., a 28% ammonia solution) at a concentration of approximately 3 mL / L. The pH of the electroplating solution may be approximately 8.7, and the temperature of the electroplating solution may be approximately 27°C. K4P2O7 can provide phosphorus ions in the electroplating solution, which can improve the load capacity and buffer the pH changes of the electroplating solution, thereby stabilizing the pH of the electroplating solution.

[0096] With reference to Tables 6-1 and 6-2, in certain embodiments, the PCl3 concentration in the electroplating solution used to form the Cu3P coating is higher than the PCl3 concentration in the electroplating solution used to form the Cu coating. In certain embodiments, the operating temperature of the electroplating solution used to form the Cu3P coating is higher than the operating temperature of the electroplating solution used to form the Cu coating. Because the temperature and composition of the electroplating solution containing Cu2P2O7·3H2O and PCl3 affect the type of reaction that occurs, the temperature and composition of the electroplating solution can be controlled using controller 131 and first mass flow controller 113 / second mass flow controller 123, respectively, to achieve the desired results.

[0097] In certain embodiments, when a Cu3P coating and a Cu coating are formed using a plating solution comprising Cu2P2O7·3H2O and PCl3 during an electroless plating operation, hydrochloric acid (HCl) and chlorine (Cl2) may be generated (as shown in Chemical Formulas 6-1 and 6-2). Hydrochloric acid (HCl) and chlorine (Cl2) may enhance the brightness and reliability of the Cu3P coating and the Cu coating.

[0098] Reference Figure 2 , Figure 2A schematic diagram of an electroplating system according to certain embodiments of the present disclosure is shown. Electroplating system 200 includes an electroplating solution 201, a cathode 202, at least a portion of which is disposed in the electroplating solution, an anode 203, at least a portion of which is disposed in the electroplating solution and separated from cathode 202, and a power supply 204 electrically connected to cathode 202 and anode 203. In certain embodiments, power supply 204 supplies direct current (DC) power (constant or pulsed). In certain embodiments, a workpiece (not shown) may be placed on the side of cathode 202 during an electroplating operation. In certain embodiments, anode 203 may be a copper phosphide anode ball (the phosphorus content may be between approximately 0.03% and approximately 0.08%).

[0099] The electroplating solution 201 includes: metal ions (such as Cu 2+ In some embodiments, the electroplating solution 201 further includes: a complexing agent, which can react with the above metal ions (such as Cu 2+ ) to form a coordination complex. In some embodiments, the electroplating solution 201 further includes a buffer that can be used to adjust or balance the pH value (i.e., acidity / alkalinity) of the electroplating solution 201. In some embodiments, the electroplating solution 201 further includes an active agent such as chloride ions (Cl - ), wherein chloride ions can also be used as an anode active agent. In some embodiments, the electroplating solution 201 further includes: other additives, such as chloride ions (Cl - ) can be used as a brightener, grain refiner, leveler, wetting agent, stress reliever, or inhibitor. For example, polyethylene glycol (PEG) can be attached to the workpiece and react with metal ions (or in some cases, phosphine ions) to form a coordination complex, thereby adjusting the electroplating reaction rate (e.g., slowing the reaction rate).

[0100] In some embodiments, the electroplating solution 201 includes CuSO4·5H2O (e.g., a concentration of about 220 g / L), sulfuric acid (e.g., a concentration of about 40 g / L), and chloride ions (e.g., about 40 ppm) to enhance brightness. In some other examples, the electroplating solution 201 may have alkaline chemicals including Cu 2+ It is also virtually cyanide-free. In some cases, the use of alkaline chemistries during manufacturing operations can mitigate material loss issues, particularly in barrier layers such as tantalum nitride (TaN) or cobalt layers in the workpiece. For example, when tantalum nitride oxidizes, it forms tantalum oxide, which can lead to further reliability issues.

[0101] In some embodiments, the electroplating solution 201 includes a phosphorus-based chemical, such as phosphine (PH3) or / and copper (II) pyrophosphate (Cu2P2O7). When phosphine (PH3) is used as the phosphorus-based chemical, gaseous phosphine (PH3) can be supplied from a chemical source 211 to the electroplating solution 201 via a conduit 212, which can be positioned adjacent to the cathode 202 (or above the workpiece). The conduit 212 can be made of polytetrafluoroethylene (PTFE), vinyl polymer, polypropylene (PP), polyvinyl chloride (PVC), polyvinylidene difluoride (PVDF), stainless steel, or other suitable conduit material. In some embodiments, the electroplating system 200 further includes a mass flow controller 213 attached to the conduit 212 to control the supply of the chemical.

[0102] In certain embodiments, a Cu3P coating is formed on a workpiece under specific conditions by utilizing an electroplating solution 201 comprising CuSO4·5H2O and PH3, which can be supplied from a chemical source 211 through a conduit 212. In certain embodiments, during the electroplating operation, a workpiece (not shown) can be placed at a cathode 202. In certain embodiments, the anode 203 can be a copper phosphide anode ball (the phosphorus content can be between about 0.03% and about 0.08%). The chemical reaction is as follows:

[0103] 3Cu 2+ +PH3+6e - →Cu3P(s)+3 / 2H 2..... (7)

[0104] Specifically, when PH3 is supplied to the electroplating solution 201, phosphorus (eg, white phosphorus or red phosphorus) may be formed:

[0105]

[0106] In this embodiment, the activation energy E(V) of the half-reaction (8) is about 0.063V to about 0.111V, and its threshold is relatively low, so this reaction can be triggered relatively easily. Moreover, it can be understood that the copper phosphide anode ball may have lower requirements for copper purity than conventional electroplating operations using other types of electroplating solutions. In certain embodiments, the oxygen ions in the copper phosphide anode ball can react with H +(which may come from pH3) to produce water, rather than forming copper oxide residues or copper oxides (which may impair the reliability of the electroplating operation). This characteristic therefore helps to reduce the manpower required to maintain the electroplating system. In an alternative embodiment, oxygen gas can be generated and reacted with hydrogen gas as shown in reaction (7), thereby producing water.

[0107] Furthermore, phosphorus can react with CuSO4 to generate Cu3P:

[0108] 11P +15CuSO4+24H2O→5 Cu3P +6H3PO4+15H2SO4 ...... (9)

[0109] From the reaction (9) for forming Cu3P, it can be found that the ratio of phosphorus (P) to CuSO4 in the electroplating solution is about 0.73 (11:15). It can be understood that here, the temperature of the electroplating solution 201 can be increased to about 50°C to about 60°C in order to provide energy and trigger the above-mentioned reaction (9). Moreover, making the phosphorus concentration in the electroplating solution 201 relatively high (as described below) can be used to trigger the reaction (9). When the phosphorus concentration in the electroplating solution 201 is relatively low and the temperature of the electroplating solution 201 is relatively low (e.g., about 20°C to about 30°C), copper is formed instead of Cu3P, as shown in the chemical reaction formula (10):

[0110] 2P+5CuSO4+8H2O→5Cu+2H3PO4+5H2SO4...... (10)

[0111] From the reaction (10) used to form Cu, it can be found that the ratio of phosphorus (P) in the electroplating solution to CuSO4 is approximately 0.4 (2:5). As mentioned above, the ratio of phosphorus (P) in the electroplating solution to CuSO4 in reaction (9) is higher than that in reaction (10).

[0112] In addition, the Cu released by the copper phosphide anode ball 2+ , which can react with electrons to generate Cu + :

[0113] 3Cu 2+ +3e - →3Cu + ...... (11)

[0114] In this embodiment, the activation energy of reaction (11) may be about 0.159V.

[0115] It can be understood that the activation energy of the following reaction (12) can be about 0.520 V, which is higher than the activation energy of reaction (13), as described below. Therefore, under the above reaction conditions, it is less likely to trigger a large-scale reaction (12):

[0116]

[0117] But the Cu in reaction (11) + , which can further react with the electrons generated by reaction (8) and phosphorus to generate Cu3P:

[0118] 3Cu + +P+3e - →Cu3P...... (13)

[0119] The phosphorus in this embodiment can further catalyze reaction (13), thereby increasing the possibility of triggering reaction (13).

[0120] Furthermore, in some embodiments, the Cu3P layer can be used as a wetting layer (and deoxidizer to remove the copper oxide layer) to form an additional Cu layer. Furthermore, phosphorus can act as a deoxidizer and wetting agent for copper, thereby alleviating the problem of oxidation of the copper layer when exposed to the environment. Therefore, the above-described techniques can be used to perform an electroplating operation to form a copper layer on a workpiece having a Cu3P coating. For example, copper can be placed at the anode and the workpiece can be placed at the cathode, and the Cu in the electroplating solution can be used to form a copper layer. 2+ , will move to and deposit on the workpiece. In some alternative embodiments, the Cu3P coating can also be formed on the cathode side. It is understood that other appropriate electroplating techniques can also be used to form the Cu3P coating.

[0121] In certain embodiments, the electroless plating operation ( Figure 1 ) and electroplating operations ( Figure 2 ) can be used for the manufacturing operations described in the following embodiments.

[0122] Reference Figure 3A , Figure 3A FIG2 is a perspective view of a wiring substrate according to certain embodiments of the present disclosure. Figure 3AA first embodiment of a wiring substrate 300 is discussed. The wiring substrate 300 includes a core substrate 301 and laminate layers 302 located on both sides of the core substrate 301. In some embodiments, the core substrate 301 can be made by impregnating a reinforcing material with a resin, wherein glass cloth, aramid fiber fabric, glass fiber fabric, glass fiber resin (e.g., FR4), etc. can be used as the reinforcing material, and the resin can be an epoxy resin, bismaleimide triazine (BT) resin, etc. The laminate layer 302 can be a buildup multilayer structure, for example, including inner layers 302A and 302B respectively attached to the front and rear surfaces of the core substrate 301, and outer layers 302A' and 302B' respectively laminated on the inner layers 302A and 302B. The lamination layer 302 may include an Ajinomoto build-up film (ABF), which includes an epoxy resin, additives, stabilizers, flame retardants, and a polyethylene terephthalate (PET) film. Alternatively, the lamination layer 302 may include other suitable lamination materials, such as epoxy resin materials, resin materials, polymer materials, ceramics, or silicon. In some cases, the ABF can be formed without using a hot compression operation or laser ablation (which may make the edges of the core substrate 301 rough and produce residues), thereby providing better reliability. The ABF can be suitable for advanced processes, such as power semiconductor components, high-frequency components, advanced circuit boards, printed circuit boards, integrated circuit boards, or the like. In some embodiments, some blind conductive paths or buried vias (not shown) can be formed in the lamination layer 302 to connect wiring 303 at different levels.

[0123] The wiring 303 may be formed using patterning techniques. In some embodiments, the wiring 303 may be formed on the core substrate 301 and at a level formed on the laminate layer 302 and then patterned (a subtractive process). In some alternative embodiments, a sacrificial layer on the core substrate 301 is patterned, and then a conductive layer is formed on the sacrificial layer and a selective removal operation is performed (an additive process). In some embodiments, the wiring 303 may include a phosphor copper alloy, such as Cu3P, and may be formed using an electroless plating operation (e.g., Figure 1 ), and / or electroplating operations (such as Figure 2 Phosphor copper alloys (especially Cu3P) can provide better device performance and have high compatibility with complex wiring configurations, and can also have smaller wiring sizes.

[0124] In some alternative embodiments, wiring 303 may comprise copper and may be formed using a multi-step operation. For example, an electroless plating operation (e.g., Figure 1A thin copper film is first deposited, followed by an electroplating operation (such as Figure 2 As described above, a thicker copper film is deposited to form wiring 303. Copper wiring formed by electroless plating has higher reliability, while copper wiring formed by electroplating has higher efficiency.

[0125] In some alternative embodiments, the wiring 303 may include copper and a phosphorus copper alloy (e.g., Cu3P). For example, an electroless plating operation may be used to first deposit a Cu3P film (e.g., Figure 1 Then, a thicker copper film (such as Figure 2 As described above), to form the wiring 303. In this embodiment, the Cu3P film can serve as a wetting layer for the copper film (and the deoxidizer can remove the copper oxide layer).

[0126] In some embodiments, the wiring substrate 300 further includes: a plated through hole (PTH) 305, which can be further electrically connected to the solder of the component, the wiring structure or the terminal. In some embodiments, the wiring substrate 300 further includes: a non-plated through hole (not shown) which can be connected to a fastener.

[0127] Reference Figure 3B , Figure 3B A perspective view of a wiring substrate according to some embodiments of the present disclosure is shown. Figure 3B A second embodiment of a wiring substrate 300' is discussed. The wiring substrate 300' and Figure 3A The wiring substrate 300 shown is similar to the wiring substrate 300, except that the wiring substrate 300' adopts a coreless substrate configuration. In other words, the coreless substrate 301' is replaced by the coreless substrate 301'. Figure 3A The core substrate 301 of the wiring substrate 300 shown in FIG. Figure 3B As shown. Although Figure 3A The appearance of the wiring substrate 300 shown in FIG. Figure 3B The wiring substrate 300 ′ shown has a similar appearance, but has different mechanical properties.

[0128] Specifically, the coreless substrate 301' can be made of a buildup resin, such as an ABF substrate. Furthermore, the laminate layers 302 formed on both sides of the coreless substrate 301' are made of prepreg material, which helps to enhance the structural strength of the wiring substrate 300'.

[0129] In some embodiments, the wiring 303 may be formed on the core substrate 301 and in the laminate layer 302, and then patterned. In some embodiments, the wiring 303 comprises: a phosphor copper alloy (e.g., Cu3P) and copper. Specifically, in some embodiments, an electroless plating operation (e.g., Figure 1 A thin Cu3P film is first deposited, followed by an electroplating operation (such as Figure 2 As described above), a copper film is formed on the thin Cu3P film to form wiring 303. As described above, phosphorus copper alloy has better wettability and a denser structure, so it can be used as a wetting layer for the copper layer (and the deoxidizer can remove the copper oxide layer). In some embodiments, the thickness of the thin Cu3P film can be as small as 1μm, or from 1μm to about 3μm. What's more, when forming a plated through hole (PTH) 305, or a blind conductive path, the conformality of the electroplated copper can be improved, so the above can be used to form a higher aspect ratio path, or a smaller wiring size. In some alternative embodiments, the wiring 303 includes: a first Cu3P layer as a wetting layer, and a second Cu3P layer located on the wetting layer. For example, each Cu3P layer can have a different composition, so that each Cu3P exhibits different properties. For example, the first Cu3P layer and the second Cu3P layer can serve as a wetting layer together. In another example, the first Cu3P layer serves as a wetting layer, while the second Cu3P layer serves as a conductive wiring. In some alternative embodiments, instead of forming a copper layer on the Cu3P layer, an additional conductive layer is formed. In some alternative embodiments, wiring 303 includes: a copper layer serving as a wetting layer, and a Cu3P layer on the wetting layer. These alternative embodiments can be used for specific products with specific requirements.

[0130] Figures 4A to 4E A third embodiment of a wiring substrate 400 is shown in FIG. 4 , which is one embodiment of the present disclosure.

[0131] Reference Figure 4A , Figure 4A A cross-sectional view of a wiring substrate at an intermediate stage of a manufacturing process is shown in accordance with certain embodiments of the present disclosure. A ceramic layer 400a is provided. In certain embodiments, ceramic layer 400a can be formed by mixing ceramic powder and a glass material (approximately 30% to 50%) with an adhesive material to form a slurry. In this embodiment, the ceramic powder can be Al2O3, AlN, BeO, or other suitable materials. The slurry is then dried to form a thin layer. Furthermore, a plurality of vias 401 can be formed by a perforation operation.

[0132] Reference Figure 4B , Figure 4B A cross-sectional view of a wiring substrate at an intermediate stage of a process operation is shown in certain embodiments of the present disclosure. Subsequently, circuits and pads (or conductive pads) may be formed. In certain embodiments, electroless plating 499 (e.g., Figure 1As described above, a phosphor copper alloy (e.g., Cu3P) layer 402 is formed on the front surface and / or the back surface of the ceramic layer 400a. In this embodiment, the phosphor copper alloy has wettability and a relatively dense structure, and thus can serve as a wetting layer for the copper layer (and a deoxidizer can remove the copper oxide layer), as described below. Figure 4C In some embodiments, the thickness of the phosphor-copper alloy layer 402 can be as small as 1 μm, or from 1 μm to about 3 μm. In some embodiments, the phosphor-copper alloy layer 402 is also formed in the vias 401 .

[0133] Reference Figure 4C , Figure 4C A cross-sectional view of a wiring substrate at an intermediate stage of a manufacturing process is shown in certain embodiments of the present disclosure. Figure 4B ) is formed on the copper layer 403. In some embodiments, the thickness of the copper layer 403 may be between about 20 μm and about 100 μm. In some embodiments, the copper layer 403 may be formed on the copper layer 403 ... Figure 2 The electroplating system 200 performs an electroplating operation, wherein the ceramic layer 400a is immersed in the electroplating solution 201 to perform the electroplating operation. In addition, a lithography operation is performed to define the position of the electronic wiring and the conductive pad. In some alternative embodiments, the phosphor copper alloy layer 402 (such as Figure 4B ) is formed on the phosphor-copper alloy layer without forming a copper layer. For example, each phosphor-copper alloy layer can have a different composition, so that each phosphor-copper alloy layer exhibits different properties and functions. In some embodiments, an electroless plating operation or an electroplating operation can be used to form the additional phosphor-copper alloy. In some alternative embodiments, the phosphor-copper alloy layer 402 (such as Figure 4B ), an additional conductive layer is formed on the copper layer without forming a copper layer. In some alternative embodiments, a copper layer is formed to serve as a wetting layer, and a phosphorus copper alloy layer is formed on the copper layer. The above alternative embodiments can be used for specific products with specific requirements.

[0134] Reference Figure 4D , Figure 4D A cross-sectional view of a wiring substrate at an intermediate stage of a manufacturing process is shown in some embodiments of the present disclosure. A plurality of ceramic layers 400a may be stacked and laminated.

[0135] Reference Figure 4E , Figure 4EA cross-sectional view of a wiring substrate at an intermediate stage of a manufacturing process is shown in certain embodiments of the present disclosure. A sintering operation is performed to obtain a wiring substrate 400. The temperature of the sintering operation may be between about 850°C and about 900°C. Furthermore, post-processing may be performed (e.g., forming additional wiring 410 on the outer surface of the wiring substrate 400, separation, additional heating, cutting, testing). As described above, the combination of the phosphor-copper alloy layer and the copper layer helps to form a high aspect ratio via with better reliability and narrower wiring. Furthermore, the phosphor-copper alloy layer can serve as a wetting layer and deoxidizer for the copper layer, thereby improving the conformality and reliability of the copper layer.

[0136] like Figure 1 and Figure 2 The electroless plating and electroplating technology can also be used for interconnect packaging structures, as shown below. Figures 5A to 5H As stated.

[0137] Reference Figure 5A , Figure 5A The present invention illustrates a cross-sectional view of an interconnect package structure at an intermediate stage of a manufacturing process according to certain embodiments of the present invention. Figure 1 and Figure 2 The electroless plating and electroplating technology can be used to interconnect packaging structures, such as packaging structures. Figure 5A In the present invention, a semiconductor substrate 501 (or, in some embodiments, a silicon interposer) is provided, and one or more conductive layers 502 may be formed on the semiconductor substrate 501. In some embodiments, the semiconductor substrate 501 may be a silicon substrate. An insulating layer 503 is formed on the semiconductor substrate 501 and then selectively removed to expose at least a portion of the conductive layer 502. In some embodiments, the insulating layer 503 comprises SiO2. In embodiments where the semiconductor substrate 501 is a silicon interposer, its thickness may be between approximately 20 μm and approximately 50 μm.

[0138] Reference Figure 5B , Figure 5B The cross-sectional view of the interconnect package structure at an intermediate stage of the process operation in certain embodiments of the present disclosure is shown. An under bump metallization (UBM) material layer 504M is formed on the insulating layer 503. The UBM material layer 504M may have a multi-layer structure, for example, including an adhesive layer, a diffusion barrier layer on the adhesive layer (to prevent the solder and copper layer from diffusing into the substrate conductive layer 502), and a phosphorus copper alloy layer (e.g., Cu3P) on the diffusion barrier layer. Figure 1 The Cu3P layer may be formed by the electroless plating technique discussed above. The thickness of the Cu3P layer may be between about 1 μm and about 3 μm.

[0139] In certain embodiments, an adhesion layer is used to mitigate lattice mismatch issues caused by the underlying silicon surface (e.g., through eutectic bonding). The adhesion layer may include at least one of: (a) a metal layer having a lattice constant relatively close to that of silicon (e.g., Ag, Al, Au, etc.), (b) a metal silicide layer (e.g., nickel silicide, cobalt silicide, palladium silicide, etc.), or (c) a wetting layer (e.g., nickel layer), wherein the lattice mismatch between nickel and silicon can be as low as approximately 0.4% and the adhesion between nickel and silicon is sufficient. In some embodiments, the thickness of the adhesion layer may be between approximately 0.5 μm and approximately 2 μm.

[0140] In certain embodiments, the diffusion barrier layer may include at least one of the following: (a) a nickel layer, which may be formed by electroless plating, or (b) a refractory metal layer, metal derivative, or metal alloy (e.g., Ti, W, Mo, Ta, V, titanium tungsten, TiW nitride, W2N, TiN, TaN, etc., which may be formed by physical vapor deposition). In some embodiments, the diffusion barrier layer may have a thickness ranging from approximately 0.1 μm to approximately 0.5 μm. The diffusion barrier layer may be used to mitigate the diffusion of solder and copper layers into the substrate conductive layer 502 and reduce internal stress.

[0141] Reference Figure 5C , Figure 5C A cross-sectional view of an interconnect package structure at an intermediate stage of a manufacturing process is shown in FIG. 1 , wherein a photoresist layer 505 is formed on an under-bump metallurgy (UBM) material layer 504M, and a lithography operation is performed using a mask 591 .

[0142] Reference Figure 5D , Figure 5D A cross-sectional view of an interconnect package structure at an intermediate stage of a fabrication process is shown in some embodiments of the present disclosure. A plurality of recesses R1 are defined in the photoresist layer 505 corresponding to the conductive layer 502 , thereby exposing at least a portion of the UBM material layer 504M from the photoresist layer 505 .

[0143] Reference Figure 5E , Figure 5EA cross-sectional view of an interconnect package structure at an intermediate stage of fabrication operations according to certain embodiments of the present disclosure is shown. A copper layer 506 may be formed in recess R1, where the copper layer 506 may directly contact the UBM material layer 504M (e.g., a phosphorus-copper alloy layer of the UBM material layer 504M). In certain embodiments, the copper layer 506 may be formed using electroplating, which, as described above, has a higher efficiency. In certain embodiments, the thickness of the copper layer 506 may be between approximately 8 μm and approximately 10 μm. An alloy layer 507 (e.g., a solder alloy layer) is then formed on the copper layer 506 and in recess R1. In certain embodiments, the thickness of the copper layer 506 may be between approximately 8 μm and approximately 10 μm. In certain embodiments, the alloy layer 507 may include a Sn-Ag alloy, such as Sn, Ag, Cu, and Sb (e.g., 96.3% Sn, 3% Ag, 0.5% Cu, and 0.2% Sb). In some alternative embodiments, alloy layer 507 may include Sn, Ag, Bi, and Cu (e.g., 93.3% Sn, 3.1% Ag, 3.1% Bi, and 0.5% Cu). In some embodiments, alloy layer 507 may have a thickness ranging from about 10 μm to about 15 μm. In some embodiments, alloy layer 507 may serve as a conductive bump for subsequent bonding operations.

[0144] Reference Figure 5F , Figure 5F A cross-sectional view of an interconnect package structure at an intermediate stage of fabrication, according to certain embodiments of the present disclosure, is shown. Photoresist layer 505 is removed, exposing the sidewalls of copper layer 506 and alloy layer 507. In certain embodiments, photoresist layer 505 can be removed by performing a stripping operation.

[0145] Reference Figure 5G , Figure 5G A cross-sectional view of an interconnect package structure at an intermediate stage of fabrication operations in certain embodiments of the present disclosure is shown. In certain embodiments, portions of the UBM material layer 504M not covered by the copper layer 506 are removed, thereby exposing portions of the underlying insulating layer 503 and forming the UBM layer 504 (which is a patterned UBM material layer 504M). In certain embodiments, the removal operation may include photolithography, etching, or other suitable removal operations. Consequently, the remaining UBM layer 504 and conductive layer 502 may be combined to form a conductive pad 509. Specifically, the conductive pad 509 comprises a phosphor-copper alloy (e.g., Cu3P).

[0146] Reference Figure 5H , Figure 5HThe present disclosure depicts a cross-sectional view of an interconnect package structure at an intermediate stage of a manufacturing process, in accordance with certain embodiments of the present disclosure. A reflow operation may be performed to form a conductive pillar comprising a copper alloy and a Sn-Ag alloy. The semiconductor substrate 501 may be bonded to a carrier 599 (e.g., an IC board or other semiconductor substrate) to produce an interconnect package. In certain embodiments, the conductive pad 509 comprising a phosphorus copper alloy discussed in the present disclosure may be applied to other multi-layer wiring structures, such as a wafer substrate, a PCB, an intermediate layer, a redistribution layer, a core substrate, a coreless substrate, a ceramic substrate, or the like. This configuration may improve the reliability and characteristics of the electrical connection.

[0147] like Figures 1 to 2 The electroless plating and electroplating can also be used for wiring substrates, such as Figures 6A to 6C As described above. Specifically, in applications related to printed circuit boards (PCBs) and integrated circuit (IC) substrates, it is important to alleviate the resistance problem caused by the narrowing of the conductive path size. Especially when transmitting high-frequency signals (such as clock signals), skin effect may occur. That is, electrons may accumulate on the surface of the conductive wiring, thereby increasing resistance and reducing component performance. Traditional methods, such as simply increasing the size of the conductive line in one direction (such as the width direction), may not be able to effectively solve the above problems. In order to completely solve the above problems, it can be applied Figure 1 and Figure 2 The electroplating technology discussed in [1] further improves the design of conductive paths in printed circuit boards (PCBs) and integrated circuit (IC) substrates. For example, it can significantly increase the effective surface area of ​​conductors used to transmit high-frequency signals, effectively addressing the skin effect.

[0148] Reference Figure 6A , Figure 6A The drawing discloses certain embodiments of a multilayer wiring structure at an intermediate stage of a process operation. A phosphor copper alloy layer 602 (e.g., Cu3P) is formed on a portion of a substrate 601, which may be an integrated circuit carrier or a printed circuit board. In certain embodiments, the substrate 601 may also be referred to as an integrated circuit carrier or a printed circuit board at an intermediate stage of a process operation, which may include a portion of a laminate layer formed thereon. In certain embodiments, the process may be performed as follows: Figure 1The electroless plating operation forms a phosphor-copper alloy layer 602. In some embodiments, the thickness of the phosphor-copper alloy layer 602 is between about 1 μm and about 3 μm. A photoresist layer 691 is selectively formed on the phosphor-copper alloy layer 602, and a portion of the phosphor-copper alloy layer 602 is exposed through the patterned photoresist layer 691. In some embodiments, the photoresist layer 691 may include a negative photoresist (e.g., polyisoprene rubber), or a positive photoresist (e.g., Novolac resin, epoxy resin photoresist (e.g., SU-8 photoresist or the like), or a polymer material (e.g., polymethylmethacrylate (PMMA) or the like).

[0149] Reference Figure 6B , Figure 6B A cross-sectional view of a multilayer wiring structure at an intermediate stage of a process operation is shown in certain embodiments of the present disclosure. A copper layer 603 is formed on a photoresist layer 691, and the portion of the upper surface of the phosphor copper alloy layer 602 is exposed from the photoresist layer 691. In certain embodiments, the copper layer 603 is formed on a photoresist layer 691. Figure 2 The electroplating operation described above forms the copper layer 603. In some alternative embodiments, the copper layer 603 may be replaced with an additional phosphorus copper alloy layer (in some examples, this layer may be formed using an electroplating operation).

[0150] Reference Figure 6C , Figure 6C A cross-sectional view of a multilayer wiring structure at an intermediate stage of a manufacturing process according to certain embodiments of the present disclosure is shown. A photoresist stripping operation is performed. It should be noted that the photoresist stripping operation performed here can use a negative photoresist such as polyisoprene rubber, or a positive photoresist such as Novolac resin or its equivalent. Compared to conventional epoxy resin photoresists (such as SU-8, PMMA or the like), the photoresists described here can form a thinner photoresist layer and can be removed by a non-conventional stripping operation: the photoresist layer 691 and a portion of the copper layer 603 directly on the photoresist layer 691. After the photoresist stripping operation, a portion of the copper layer 603 is retained. In certain embodiments, the remaining copper layer 603 may expose a portion of the phosphor-copper alloy layer 602. The phosphor-copper alloy layer 602 and the remaining copper layer 603 may be collectively referred to as a zigzag conductive line 604, wherein at least one upper surface of the zigzag conductive line 604 has a zigzag profile. In other words, the zigzag wire 604 includes: a protrusion 604T protruding in a direction away from the substrate 601. Furthermore, the zigzag wire includes: a phosphor copper alloy layer and a copper layer directly contacting the phosphor copper alloy layer. In some embodiments, the zigzag wire may be repeated. Figure 6B and Figure 6CThe operation is performed to increase the depth T1 of the protrusion 604T, wherein the ratio of the depth T1 of the zigzag conductor 604 to the height T2 is: about 10% to about 90%. In some embodiments (such as, for a wiring structure in a conventional PCB or IC carrier), the thickness T2 may be between: about 20μm and about 60μm. In some embodiments (such as, for a wiring structure in a high-power PCB or a high-power IC carrier), the thickness T2 may be as high as 100μm. By making the depth T1 about 10% to about 90% of the thickness T2, the effective surface area of ​​the zigzag conductor 604 can be increased, thereby solving the resistance problem caused by the skin depth effect. In addition, its reliability can be sufficient. When the multi-layer wiring structure 600 (such as Figure 6D When the heat capacity of the zigzag wire 604 is considered to be a relatively important factor, the above ratio can be closer to 10%. When the heat dissipation surface area of ​​the zigzag wire 604 is considered to be a relatively important factor, the above ratio can be closer to 90%.

[0151] In some alternative embodiments, the copper layer 603 may be replaced by additional phosphorus copper alloy layers. For example, each phosphorus copper alloy layer may have a different composition, so that each phosphorus copper alloy layer exhibits different properties and functions. Figure 2 The electroplating operation, or Figure 1 The electroless plating operation described above forms each phosphor copper alloy layer. In some alternative embodiments, an additional conductive layer is formed on the phosphor copper alloy layer 602 instead of a copper layer. In some alternative embodiments, the phosphor copper alloy layer and the copper layer are formed in the opposite order, that is, the phosphor copper alloy layer on the copper layer has a sawtooth profile. Figures 6A to 6C The above-described operation can adjust and optimize the composition of the electroplating solution so that the photoresist layer 691 can be easily stripped or separated from the copper layer 603 without removing a large amount of copper residue due to the stripping operation. For example, the photoresist layer 691 can be a multi-layer structure including a conventional photoresist layer (e.g., positive photoresist or negative photoresist) and a stripping photoresist layer (e.g., SU-8 or PMMA). Generally, the copper layer 603 can be formed by electron gun evaporation or sputtering to a thickness of up to 40 μm (for conventional PCBs or IC carriers) or up to 1000 μm (for high-power PCBs or high-power IC carriers). Alternatively, the copper layer 603 can be formed by electroplating. For example, by reducing the dosage of the wetting agent in the electroplating solution, the electroplated product (i.e., the copper layer 603) is less likely to adhere to the stripping photoresist layer during the stripping operation, thereby making the corrugated profile of the zigzag conductive line 604 more distinct.

[0152] In another embodiment, the photoresist layer 691 can be a single-layer structure comprising a conventional photoresist layer (e.g., positive or negative photoresist), and an additional patterning operation can be performed to pattern the phosphor-copper alloy layer 602 before forming the copper layer 603. The patterning operation creates grooves in the phosphor-copper alloy layer 602, thereby increasing the extent of the grooves in the sawtooth structure. Subsequently, the copper layer 603 can be formed by electroplating to a thickness of up to 3 μm (e.g., for interconnect structures in conventional IC substrates), up to 30 μm (e.g., for interconnect structures in high-power ICs such as IGBTs or MOSFETs), up to 40 μm (e.g., for wiring structures in conventional PCBs or IC substrates), or up to 100 μm (e.g., for wiring structures in high-power PCBs or high-power IC substrates). For example, the copper layer 603 can be formed by electroplating. For example, by reducing the dosage of the wetting agent in the electroplating solution and increasing the dosage of the leveling agent, the electroplated product (i.e., the copper layer 603) is less likely to adhere to the photoresist layer 691 during the removal operation of the photoresist layer 691, and the corrugated profile of the zigzag conductive line 604 becomes clearer. In addition, although Figure 6C Not shown, an additional phosphorus copper alloy layer 602 may be conformally formed on the copper layer 603 (e.g., by electroless plating) to protect the copper layer 603 below the sawtooth feature from oxidation and to prevent copper atoms from diffusing outward from the copper layer 603.

[0153] Reference Figure 6D and Figure 6D ', Figure 6D depicts a cross-sectional view of a multilayer wiring structure at an intermediate stage of a fabrication process according to certain embodiments of the present disclosure, and Figure 6D 'for Figure 6DAn enlarged fragmentary view of a portion A of the multilayer wiring structure 600 is shown. A laminate layer 611 (e.g., an Ajinomoto laminate film) can be formed to cover the zigzag conductive line 604, such that at least a portion of the zigzag conductive line 604 is embedded in the multilayer wiring structure 600. In some embodiments, the multilayer wiring structure 600 further includes other conductive components including a phosphor-copper alloy layer 602 and a copper layer 603. In some embodiments, the multilayer wiring structure 600 includes a through-via 621 (which can be an electroplated through-via or a non-electroplated through-via), a buried via 622 electrically connected to the zigzag conductive line 604, and a blind via 623 electrically connected to the zigzag conductive line 604. In some embodiments, the phosphor-copper alloy layer can penetrate the through-via 621 (electroplated), the buried via 622, and the blind via 623, such that the phosphor-copper alloy layer 602 at least partially laterally surrounds the copper layer 603. In some embodiments, additional removal operations may be performed to modify the shapes of the vias used to form the through vias 621 (plated), buried vias 622, and blind vias 623. For example, patterning, etching, drilling, or other suitable removal operations may be performed to create a jagged sidewall profile for the through vias 621 (plated), buried vias 622, and blind vias 623, thereby alleviating resistance issues. In some embodiments, the diameter of the (non-plated) through vias 621 of the printed circuit board may be as small as about 5 μm, or from about 5 μm to about 20 μm, and the height may be as high as about 100 μm, or from about 20 μm to about 100 μm. In some embodiments, the diameter of the (non-plated) through vias 621 of the integrated circuit substrate may be as small as about 2 μm, or from about 2 μm to about 20 μm, and the height may be as high as about 100 μm, or from about 20 μm to about 100 μm.

[0154] Reference Figure 6D and Figure 6D , Figure 6D Some embodiments of the present disclosure are shown. Figure 6D An enlarged partial view of a portion A of a multi-layer wiring structure. An alternative embodiment of the zigzag conductor 604 is as follows Figure 6D As shown, Figure 6D 'and Figure 6D The difference of the zigzag wire 604 is that Figure 6D The zigzag conductive line 604 includes zigzag profiles on its upper and lower surfaces. Specifically, the zigzag conductive line 604 includes protrusions 604T and 604B, which extend in opposite directions. The bottom of the zigzag conductive line 604 has a first portion 604BA that directly contacts the phosphor-copper alloy layer 602, and a second portion 604BB that is located above the first portion 604BA and separate from the phosphor-copper alloy layer 602.

[0155] In some embodiments, gaps 605 are provided between the protrusions 604B located on the lower surface of the zigzag conductor 604. In some embodiments, the gaps 605 are filled with a filler, such as a polymer, a photoresist (e.g., SU-8 or PMMA), a dielectric layer, or an appropriate spacer material. In some alternative embodiments, the gaps 605 are empty (e.g., filled with air). Here, the overhang structure not only increases the effective surface area of ​​the conductive wiring, thereby reducing the skin depth effect and lowering the resistance, but also significantly reduces the parasitic capacitance effect (e.g., the relative dielectric constant can be reduced to approximately 1). This can increase the signal transmission speed.

[0156] form Figure 6D The serrated wire 604 further comprises the following steps: 6A to 6D The operation discussed herein selectively forms a filler (e.g., photoresist, polymer, dielectric layer, spacer material, etc.) on the phosphor-copper alloy layer 602, forms a copper layer 603 on the filler, and forms protrusions 604T on the upper surface of the copper layer 603, including a stripping operation for forming a sawtooth profile. In some embodiments, the filler at least partially remains in the gaps 605 between the protrusions 604B after the stripping operation. In some alternative embodiments, the filler is removed from the gaps 605 between the protrusions 604B after the stripping operation. By having a sawtooth profile at the upper and bottom surfaces, Figure 6D The sawtooth profile 604 in the embodiment can further reduce the resistance problem caused by the skin effect. In some embodiments, Figure 6D 'or Figure 6D The zigzag conductor 604 discussed in the previous section is located near the top surface of the multilayer wiring structure 600. In some embodiments, Figure 6D 'or Figure 6D The zigzag conductive line 604 discussed above can be used to transmit high-frequency signals. In some embodiments, a conductive pad comprising a phosphor-copper alloy (e.g., Cu3P) can be formed on the multilayer wiring structure 600 (e.g., by electroless plating, electroplating, patterning, deposition, etc.), thereby further connecting to external conductive features.

[0157] In certain embodiments, the Figures 7A to 7H The operation, preparation Figure 6D The zigzag wire 604 in Figure 7AIn the present invention, a phosphor-copper alloy 701 can be formed on a multi-layer wiring structure (e.g., a wafer, PCB, or interlayer) to serve as a wetting layer, which serves as a base for the subsequent formation of zigzag-shaped conductive lines. In some embodiments, an additional barrier layer, such as a TiN layer (not shown), can be formed before forming the phosphor-copper alloy 701. A conventional photoresist 702 (e.g., which can be positive or negative photoresist) is patterned on the phosphor-copper alloy 701 and the dielectric region 701D surrounding the phosphor-copper alloy 701 to have a plurality of grooves, thereby exposing the phosphor-copper alloy 701 underneath. Figure 7B In the embodiment, a copper layer 703 is plated on the photoresist 702 and fills the groove. In some embodiments, the thickness of the copper layer 703 is less than the thickness of the photoresist 702, so that the upper surface of the photoresist 702 is higher than the upper surface of the copper layer 703 covering the groove. Figure 7C In the embodiment, an etching operation is performed to remove the portion of the copper layer 703 above the photoresist 702. Due to the shielding position of the adjacent higher photoresist 702, the other portion of the copper layer 703 filling the trench can also be consumed to a limited extent. Figure 7D In the embodiment, another portion of the copper layer 703' may be plated to cover the upper surface of the photoresist 702 exposed by the etching operation and the portion of the copper layer 703 filling the trench.

[0158] exist Figure 7E In FIG, a conventional photoresist 702' (eg, a positive photoresist or a negative photoresist) is patterned on the copper layer 703' and the dielectric region 701D surrounding the phosphor copper alloy 701 to have a plurality of grooves, thereby exposing the underlying copper layer 703'. Figure 7F In the embodiment, another copper layer 703" is plated on the photoresist 702' and fills the groove pattern therein. In some embodiments, the thickness of the copper layer 703" is less than the thickness of the photoresist 702', so that the upper surface of the photoresist 702' is higher than the upper surface of the copper layer 703" covering the groove. Figure 7G In a single stripping operation, the photoresist 702 and the photoresist 702' are removed, and the copper layers 703 and 703" are the sawtooth components of the sawtooth conductor 603, as shown in FIG. Figure 6D As shown. Although Figure 7H Although not shown, an additional phosphorus copper alloy layer 704 may be conformally formed on the copper layer 703 (e.g., by using an electroless plating operation) to protect the underlying copper layers 703, 703', 703" having the serrated features from oxidation and to prevent copper atoms from diffusing outward from the copper layers 703, 703', 703".

[0159] Figures 6A to 6D The above-described technology can also be applied to IC substrates and IC interlayers. For example, the wiring of the IC substrate or IC interlayer may include a phosphor copper alloy layer (e.g., cuprous phosphide) and a copper layer in direct contact with the phosphor copper alloy layer. In some embodiments, the wiring of the integrated circuit substrate may have: Figure 6C to Figure 6D" In certain embodiments, the thickness of the phosphor-copper alloy (eg, cuprous phosphide) layer may be between about 2 nm and about 20 nm, and the thickness of the copper layer may be between about 20 nm and about 2,000 nm.

[0160] In some embodiments, the wiring of the middle layer of the integrated circuit may have: Figure 6C to Figure 6D" In certain embodiments, the phosphor-copper alloy (e.g., cuprous phosphide) layer may have a thickness of up to about 200 nm, or from about 20 nm to about 200 nm; and the copper layer may have a thickness of up to about 20 μm, or from about 5 μm to about 20 μm. A through-silicon via formed in an intermediate layer of an integrated circuit may have a width as low as 5 μm, or from about 5 μm to about 20 μm, and a height as high as about 60 μm, or from about 20 μm to about 60 μm.

[0161] Furthermore, a heat sink comprising a phosphorus copper alloy (e.g., cuprous phosphide) layer as described herein can be integrated into the embodiments described herein, including but not limited to a wafer substrate, a PCB, an IC intermediate layer, a redistribution layer, a core substrate, a coreless substrate, a ceramic substrate, or the like. For example, the heat sink may include a nickel (Ni) film (having a thickness ranging from about 0.5 μm to about 2 μm), a phosphorus copper alloy layer on the Ni film (having a thickness ranging from about 2 μm to about 20 μm), and a copper layer on the phosphorus copper alloy layer (having a thickness ranging from about 200 μm to about 2000 μm). The phosphorus copper alloy layer can exhibit good thermal conductivity and the ability to slow down the oxidation of the copper layer. For example, the heat sink may also be further formed on: Figure 3A On the surface of the wiring substrate 300, Figure 3B On the surface of the wiring substrate 300 ′, Figures 4A to 4E On the surface of the wiring substrate 400, Figures 5A to 5H On the surface of the semiconductor substrate 501, or on the surface of the carrier 599, or Figures 6A to 6D on the surface of the multilayer wiring structure.

[0162] This disclosure proposes a method for forming semiconductor devices (e.g., integrated circuit substrates, IC interposers, or the like), integrated circuit carriers, and printed circuit boards (PCBs) using a phosphor-copper alloy (e.g., Cu3P (cuprous phosphide)) to replace conventional copper sputtering operations. Copper sputtering often presents defects at advanced process nodes. For example, particularly when forming high-aspect-ratio vias, the deposited material can become lodged in the openings of the recesses, creating voids in the vias and leading to reliability issues.

[0163] Compared to the sputtered copper used in the comparative example, the phosphor-copper alloy exhibits superior performance in terms of corrosion resistance, wear resistance, wettability, structural density, strength, toughness, conformality, and processability. Furthermore, the electrical and thermal conductivity of the phosphor-copper alloy is comparable to that of sputtered copper. Furthermore, the phosphor-copper alloy acts as a wetting layer for the copper layer, alleviating voiding issues and improving copper conformality in high-aspect-ratio vias.

[0164] Figure 1 Electroless plating operations and implementations of electroless plating systems are discussed in detail. Advantages of electroless plating technology include compatibility and product quality, which can alleviate voiding and reliability issues. Furthermore, electroless plating systems can utilize electroless plating system 100 to control the plating solution under different conditions to form Cu3P coatings and Cu coatings. Figure 1 The electroplating solution further includes chemicals that can further improve product quality.

[0165] Figure 2 The electroplating operation and implementation of the electroplating system are discussed in detail. Advantages of electroplating technology include high reaction rates and high production efficiency. Furthermore, the electroplating system can be used to form a Cu3P coating and a Cu coating from the electroplating solution 201 under different conditions.

[0166] Can be used as Figure 1 The electroless plating operation, or Figure 2 The electroplating operation described above forms a wetting layer that improves the conductive component. Furthermore, the Cu3P layer can serve as a wetting layer (and deoxidation layer) to facilitate the formation of a Cu layer thereon. For example, the Cu3P layer can be in direct contact with the Cu layer. Therefore, it is possible to Figure 1 and Figure 2 The technology described, for example, first uses Figure 1 The electroless plating operation forms a Cu3P layer, which is then used Figure 2 The electroplating operation is performed to form the Cu layer. This technology can optimize the balance between reliability and production efficiency. For example, the structure formed by this technology can be used for: a wiring substrate 300 including a core substrate (such as Figure 3A As described above), including a wiring substrate 300' without a core substrate (such as Figure 3B As described above), and a wiring substrate 400 including a ceramic substrate (such as Figures 4A to 4E Alternatively, use Figure 1 The electroless plating operation, or Figure 2 The copper formed by the electroplating operation can also be used as a wetting layer to improve reliability.

[0167] The above technology can be used to Figures 5A to 5HThe interconnect package structure described above utilizes a phosphor copper alloy layer (e.g., Cu3P) as a UBM layer located on the diffusion barrier layer, and a copper layer located on the UBM layer, thereby forming a conductive pillar. This technology can further improve the reliability of the bonding. In certain embodiments, such as Figure 5G The height of the copper layer 506 is shown to be approximately 60 μm.

[0168] The above technology can be further used to Figures 6A to 6D , in the interconnect packaging structure, the combination of the phosphor-copper alloy layer (such as Cu3P) and the copper layer enables the formation of complex conductive path configurations in the printed circuit board (PCB) and the integrated circuit (IC) carrier, so as to deal with the problems caused by the skin effect. Specifically, by forming a serrated profile on the upper surface and / or lower surface of the serrated wire 604, the problems caused by the skin effect can be alleviated. The serrated profile forms a hanging structure (located on the upper surface or the lower surface, filled with filler or air). This configuration can not only increase the effective surface area of ​​the conductive wiring, thereby alleviating the skin effect: it can reduce resistance, but also can substantially alleviate the parasitic capacitance effect (for example, the relative dielectric constant can be reduced to about 1). Therefore, the signal transmission rate can be improved. As Figure 1 The electroless plating operation, or Figure 2 The electroplating operation may be combined with a stripping operation to form the sawtooth profile.

[0169] Certain embodiments of the present disclosure provide a multi-layer wiring structure comprising a plurality of dielectric layers and a plurality of conductive wiring layers interlaced with the dielectric layers, wherein the conductive wiring layers comprise a phosphor-copper alloy.

[0170] Certain embodiments of the present disclosure provide an interconnect package structure including a substrate and a conductive pad located on the substrate, wherein the conductive pad includes a phosphor-copper alloy.

[0171] Certain embodiments of the present disclosure provide a method for forming a wiring structure, comprising forming a phosphorus-copper alloy layer on a loading plate by performing an electroplating operation, and forming a dielectric layer on the patterned phosphorus-copper alloy layer, wherein forming the patterned phosphorus-copper alloy layer includes providing an electroplating solution having a copper source and a phosphorus source.

[0172] The above description briefly introduces the features of certain embodiments of the present invention, so that those skilled in the art can more fully understand the various aspects of the present disclosure. Those skilled in the art can easily use the present disclosure as a basis to design or modify other operations and structures to achieve the same purposes and / or advantages as the embodiments described herein. Those skilled in the art should understand that these equivalent embodiments still fall within the spirit and scope of the present disclosure, and that various changes, substitutions, and modifications can be made thereto without departing from the spirit and scope of the present disclosure.

[0173] Furthermore, the scope of this disclosure is not intended to be limited to the specific embodiments of the processes, machines, articles, compositions of matter, apparatus, methods, and steps described in the specification. As will be readily apparent to those skilled in the art from the disclosure herein, existing or later developed processes, machines, articles, compositions of matter, apparatus, methods, or steps may be utilized in accordance with this disclosure to perform the same functions or achieve the same results as the corresponding embodiments described herein. Accordingly, the appended claims also encompass such processes, machines, articles, compositions of matter, apparatus, methods, and steps.

[0174]

Explanation of symbols

[0175] 100: Electroless plating system

[0176] 101: Processing Room

[0177] 111: Phosphorus chemical source

[0178] 112: First Catheter

[0179] 113: First mass flow controller

[0180] 121: Copper chemical source

[0181] 122: Second catheter

[0182] 123: Second mass flow controller

[0183] 131: Controller

[0184] 200: Electroplating system

[0185] 201: Electroplating solution

[0186] 202: cathode

[0187] 203: Anode

[0188] 204: Power supply

[0189] 211: Chemical Source

[0190] 212: Catheter

[0191] 300, 300', 400: Wiring substrate

[0192] 301: Core substrate

[0193] 302: Laminated layer

[0194] 302A, 302B: inner layer

[0195] 302A', 302B': outer layer

[0196] 303: Wiring

[0197] 400a: Ceramic layer

[0198] 499: Electroless Plating

[0199] 402, 602, 704: Phosphor copper alloy layer

[0200] 403, 506, 603, 703, 703', 703": copper layer

[0201] 501: Semiconductor substrate

[0202] 502: Conductive layer

[0203] 503: Insulation layer

[0204] 504: UBM layer

[0205] 504M: UBM material layer

[0206] 505, 691: Photoresist layer

[0207] 507: alloy layer

[0208] 509: Conductive pad

[0209] 591: Shield

[0210] 599: Carrier board

[0211] 600: Multi-layer wiring structure

[0212] 601: Substrate

[0213] 604: serrated wire

[0214] 604BA: Part I

[0215] 604BB: Part 2

[0216] 604B, 604T: protrusion

[0217] 605: Gap

[0218] 611: Laminated layer

[0219] 621: Through the passage

[0220] 622: buried via

[0221] 623: Blind hole

[0222] 701: Phosphor copper alloy

[0223] 701D: Dielectric area

[0224] 702, 702': Photoresist

[0225] R1: Groove

[0226] T1: Depth

[0227] T2: Thickness

Claims

1. A multi-layer wiring structure comprising: a plurality of laminate layers; and a plurality of conductive wiring layers interleaved with the plurality of laminate layers, wherein the plurality of conductive wiring layers comprise a phosphorus copper alloy, wherein the phosphorus content of the phosphorus copper alloy is between 13.98% and 14.39%, in, The plurality of conductive wiring layers further include a zigzag conductive line having at least two adjacent protrusions and an air gap between the at least two adjacent protrusions. One of the plurality of conductive wiring layers includes a copper layer and a phosphor-copper alloy layer formed of the phosphor-copper alloy, the phosphor-copper alloy is exposed to the air gap, and the phosphor-copper alloy layer is interposed between the copper layer and the air gap to isolate the copper layer from the air gap.

2. The multilayer wiring structure of claim 1, wherein the plurality of laminate layers comprise polymer material, ceramic or silicon. 3 . The multilayer wiring structure according to claim 1 , wherein the zigzag conductive line has a first plurality of protrusions on an upper surface of the zigzag conductive line.

4. The multilayer wiring structure according to claim 3, wherein the phosphorus copper alloy layer directly contacts the copper layer. 5 . The multi-layer wiring structure according to claim 3 , further comprising a second plurality of protrusions located on a lower surface of the zigzag-shaped conductive line. The multi-layer wiring structure according to claim 3 , wherein the zigzag conductive lines are used to transmit high-frequency signals.

7. The multilayer wiring structure as claimed in claim 3, wherein the zigzag conductive line is disposed adjacent to an upper surface of the multilayer wiring structure.

8. The multi-layer wiring structure according to claim 3, further comprising a conductive path electrically connected to a plurality of the zigzag-shaped conductive lines, wherein the conductive path comprises Cu3P and copper.

9. The multilayer wiring structure according to claim 1, wherein the phosphorus copper alloy comprises Cu3P.

10. The multilayer wiring structure according to claim 1, wherein at least a portion of the phosphorus copper alloy is embedded in the laminate layer.

11. The multilayer wiring structure according to claim 1, wherein the phosphorus copper alloy layer is further interposed between the copper layer and one of the plurality of laminate layers.

12. A multi-layer wiring structure comprising: Circuit board, including: laminated structure; a conductive member comprising a copper layer and a phosphor-copper alloy layer, the conductive member comprising a sawtooth surface profile, wherein the sawtooth surface profile further comprises a plurality of second protrusions; and a gap between two adjacent second protrusions, wherein the phosphor-copper alloy is exposed in the void, wherein the phosphor-copper alloy layer is located between the copper layer and the void and isolates the copper layer from the void, The conductive member further includes a conductive wiring extending along a horizontal direction, wherein the conductive wiring includes a sawtooth surface profile.

13. The multi-layer wiring structure according to claim 12, wherein the conductive wiring is used to transmit high-frequency signals. 14 . The multi-layer wiring structure according to claim 12 , wherein the sawtooth surface profile comprises a plurality of first protrusions extending from a main portion of the conductive wiring and protruding toward a first direction. 15 . The multilayer wiring structure according to claim 14 , wherein the plurality of second protrusions extend along the main portion of the conductive wiring and protrude in a second direction opposite to the first direction. 16 . The multilayer wiring structure according to claim 15 , further comprising a filler interposed between two of the second protrusions, wherein the filler comprises a material different from that of the laminate structure, the material of the filler comprising a polymer.

17. The multilayer wiring structure of claim 12, wherein the phosphorus copper alloy layer is in direct contact with the laminate structure.

18. The multilayer wiring structure according to claim 12, wherein the phosphorus copper alloy layer comprises Cu 3-x P, where x is less than 0.

1.

19. The multi-layer wiring structure according to claim 12, wherein the phosphorus copper alloy layer is located below a projection area of ​​the copper layer.

20. A multi-layer wiring structure comprising: Circuit board, including: a laminate structure laminated on a first plane; and a vertical passage extending through the laminate structure in a direction perpendicular to the first plane; a horizontal conductive line parallel to the first plane connected to the vertical via, wherein the horizontal conductive line is configured to transmit a high-frequency signal, wherein the horizontal conductive line has a sawtooth profile, wherein the sawtooth profile further comprises a plurality of second protrusions; and an air gap between two adjacent second protrusions, The horizontal conductive line includes a first phosphor-copper alloy layer and a first copper layer. The first phosphor-copper alloy layer has a first surface facing the air gap and a second surface covering the first copper layer to isolate the first copper layer from the air gap.

21. The multi-layer wiring structure of claim 20, wherein the vertical via further comprises a second phosphorus-copper alloy layer and a second copper layer, the second copper layer being laterally surrounded by the second phosphorus-copper alloy layer.

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