Improved adhesion strength of metal-organic interfaces in electronic devices

Abstract

A method for improving the adhesion of metal-organic interfaces in electronic devices includes providing a substrate having a metal structure, treating the surface of the metal structure to form a single-layer coating of a selected chemical composition on the surface, and covering the treated surface with an organic material.

Description

[Technical Field]

[0001]

[0001] Cross-Reference to Related Applications This application is a divisional continuation-in-part of U.S. Patent Application No. 18 / 137,876 filed on April 21, 2023, the entire content of which is incorporated herein by reference.

[0002]

[0002] The present disclosure relates to improving the adhesive strength of metal-organic interfaces in electronic devices. [Background Art]

[0003]

[0003] The manufacturing process of electronic (or photonic) devices consists of many consecutive steps for fabricating circuits on a wafer or panel (collectively referred to herein as a substrate) of material (e.g., semiconductor wafers, glass panels, printed circuit boards, organic / ceramic substrates, etc.). Any source of defect introduced during the manufacturing process reduces the yield of the resulting device. One cause of defect is insufficient adhesion at the metal-organic interface of the device. Electronic devices (e.g., package substrates, integrated circuit chips, optoelectronic devices, etc.) contain numerous metal-organic interfaces. The adhesion between the metallic component (e.g., interconnects, landing pads, vias, etc.) and the organic component (e.g., dielectric material, molding compound, underfill material, etc.) at the metal-organic interface can be impaired for many reasons. For example, the quality / structure of the material at the interface, particles / residues embedded in the interface (debris, chemicals, etc.), high thermomechanical interfacial forces (e.g., due to a mismatch in CTE), etc. Poor adhesion between metal (e.g., copper pads) and organic (e.g., dielectric) at the interface can introduce defects at the interface (e.g., delamination, cracks, etc.), leading to reduced device yield and / or reliability. A strong metal-organic interface ensures that downstream processes (e.g., chemicals used during downstream processes and / or process conditions) do not degrade the adhesion strength of the interface. Furthermore, miniaturization of electronic devices requires miniaturization of integrated circuit (IC) substrates (e.g., printed circuit boards (PCBs)) consisting of layers of organic material (generally referred to as build-up layers, or dielectric layers including polymers, build-up layers, etc.) and layers of metal (e.g., copper, aluminum, gold, etc.) (e.g., coatings, wires, planes, vias, etc.). To manufacture fine copper circuits with small line widths and space widths for next-generation electronic devices, it is necessary to improve the adhesion between copper and organic layers.

[0004]

[0004] Current adhesion improvement methods rely on surface roughening of the metal surface to allow overlapping dielectric layers to mechanically interlock with the metal surface and improve adhesion. For example, the surface of a metal interconnect is modified by etching, plasma ablation, etc., before depositing the dielectric layer to improve adhesion between the metal and the dielectric. However, such surface roughening can adversely affect the electrical performance of electronic devices and / or lead to reliability problems. For example, high-frequency applications may require low surface roughness, etching / ablation may require an additional cleaning step and / or may cause debris from the roughening process to redeposit and embed in the interface. The adhesion improvement systems and methods of this disclosure can mitigate at least some of the above drawbacks. However, the scope of this disclosure is defined by the claims and not by the ability to solve any problems. [Overview of the project]

[0005]

[0005] Electronic devices with improved interfacial adhesion strength at metal-organic interfaces, and methods for improving interfacial adhesion strength are disclosed.

[0006]

[0006] In one embodiment, a method for improving the adhesion of a metal-organic interface in an electronic device is disclosed. The method comprises providing a substrate on which a metal structure is formed, and treating the surface of the metal structure with a vapor of a chemical composition to form a single layer coating of the chemical composition on the surface of the metal structure, wherein the chemical composition comprises at least one of (i) 2-hydroxyethyl methacrylate phosphate, (ii) vinylphosphonic acid, (iii) N-[3-(dimethylamino)propyl]methacrylamide, (iv) 2-(diethylamino)ethyl methacrylate, (v) 2-(dimethylamino)ethyl methacrylate, (vi) 2-aminoethyl methacrylate hydrochloride, or (vii) 2,3-epoxypropyl methacrylate. After treating the surface of the metal structure, the treated surface is coated with an organic material. Herein, the metal-organic interface between the treated surface of the metal structure and the coated organic layer has improved adhesion.

[0007]

[0007] In another embodiment, a method for improving the adhesion of a metal-organic interface in an electronic device is disclosed. The method comprises providing a substrate having a copper interconnect structure and treating the surface of the copper interconnect structure with a vapor of a chemical composition to form a single layer coating of the chemical composition on the surface of the copper interconnect structure, wherein the chemical composition comprises at least one of (i) 2-hydroxyethyl methacrylate phosphate, (ii) vinylphosphonic acid, (iii) N-[3-(dimethylamino)propyl]methacrylamide, (iv) 2-(diethylamino)ethyl methacrylate, (v) 2-(dimethylamino)ethyl methacrylate, (vi) 2-aminoethyl methacrylate hydrochloride, or (vii) 2,3-epoxypropyl methacrylate. The method may also comprise coating the treated surface of the copper interconnect structure with parylene after treatment, wherein the metal-organic interface between the treated surface of the copper interconnect structure and the coated parylene has improved adhesion.

[0008]

[0008] In yet another embodiment, an electronic device having a metal-organic interface is disclosed. The device may comprise a substrate having a metallic structure and a single-layer coating of a chemical composition formed on the surface of the metallic structure. The chemical composition may comprise at least one of (i) 2-hydroxyethyl methacrylate phosphate, (ii) vinylphosphonic acid, (iii) N-[3-(dimethylamino)propyl]methacrylamide, (iv) 2-(diethylamino)ethyl methacrylate, (v) 2-(dimethylamino)ethyl methacrylate, (vi) 2-aminoethyl methacrylate hydrochloride, or (vii) 2,3-epoxypropyl methacrylate. The device may also comprise an organic material layer disposed on the single-layer coating of the chemical composition.

[0009]

[0009] The accompanying drawings incorporated herein and constituting part of the disclosure illustrate exemplary embodiments and are used together with this specification to illustrate the principles disclosed. In these drawings, where appropriate, reference numbers indicating the same or similar structures, components, materials, and / or elements in different figures are similarly labeled. Various combinations of structures, components, and / or elements other than those specifically shown are contemplated and are understood to be within the scope of this disclosure.

[0010]

[0010] For simplicity and clarity of explanation, the drawings illustrate the general structure of various embodiments described. Details of well-known components or features may be omitted to avoid obscuring other features, as these omitted features are well-known to those skilled in the art. Furthermore, features in the drawings are not necessarily drawn to scale. Dimensions of some features may be exaggerated relative to other features (see, for example, Figure 3B) to improve understanding of the exemplary embodiments. Those skilled in the art will understand that features in the drawings are not necessarily drawn to scale and should not be considered to represent dimensions or proportional relationships between different features in the drawings unless otherwise indicated. In addition, even if not explicitly mentioned, aspects described with reference to one embodiment or drawing may be applicable to other embodiments or drawings and may be used together with other embodiments or drawings. [Brief explanation of the drawing]

[0011] [Figure 1A] Figure 1A is a simplified schematic diagram of a metal-organic interface in an electronic device. [Figure 1B] Figure 1B is a schematic cross-sectional view of an exemplary electronic device including the interface of Figure 1A. [Figure 2A] Figure 2A is a flowchart illustrating an exemplary method for treating the metal surface at the metal-oxide interface shown in Figure 1A. [Figure 2B] Figure 2B is a flowchart of another exemplary method for treating a metal surface at the metal-oxide interface shown in Figure 1A. [Modes for carrying out the invention]

[0012]

[0015] All relative terms such as “about,” “substantially,” and “approximately” indicate a possible variation of ±10% (unless otherwise specified or a different degree of variation is designated). For example, a feature disclosed as having a thickness (or length, width, depth, etc.) of about “t” units may have a thickness that varies from (t-0.1t) units to (t+0.1t) units. In some cases, this specification also provides context for some of the relative terms used. For example, a structure described as substantially flat (e.g., a coating edge) may deviate by ±10% from perfectly flat. Furthermore, a range described as varying from 5 to 10 (5-10) or varying between 5 to 10 (5-10) includes the endpoints (i.e., 5 and 10). Furthermore, as used herein, a composition comprising at least one of A, B, or C is used to refer to a composition comprising one or more of A, B, or C. For example, compositions containing only A, compositions containing only B, compositions containing only C, compositions containing both A and B, compositions containing both A and C, compositions containing A, B, and C, and so on.

[0013]

[0016] Unless otherwise defined, all technical terms, notations, and other scientific or specialized terms used herein have the same meaning as those commonly understood by those skilled in the art to which this disclosure belongs. Some components, structures, and / or processes described or referenced herein are well understood and commonly used by those skilled in the art using conventional methodologies. These components, structures, and processes are not described in detail. All patents, applications, published applications, and other publications that are mentioned as being incorporated herein by reference are incorporated in their entirety by reference. If any definition or description in this disclosure contradicts or otherwise contradicts the definitions and / or descriptions in those references, the definitions and / or descriptions in this disclosure shall prevail over those in the references incorporated by reference. None of the references described or referenced herein are considered prior art to this disclosure. Note that in this disclosure, the term “electronic device” is used to encompass all components and electronic / photonic assemblies (e.g., package substrates, printed circuit boards, interposers, integrated circuit chips, etc.).

[0014]

[0017] The following discussion describes exemplary methods for improving the interfacial adhesion strength of a metal-organic interface in an electronic device, and the electronic device resulting from the improved interfacial adhesion strength. Figure 1A is a simplified diagram of the metal-organic interface 30 of an exemplary electronic device shown in Figure 1B. The interface 30 includes a metal structure 10 (e.g., a coating, wire, plane, pad, via wall, etc.) on which an organic layer 20 is formed on one of its surfaces. In the electronic device of this disclosure, a single-layer coating 15 of a chemical composition formed at the interface between the metal structure 10 and the organic layer 20 improves the adhesion strength of the metal-organic interface. The organic layer 20 can be formed on the metal structure 10 by any known method used in the manufacture of the electronic device (e.g., deposition, plating, growth, spraying, etc.). In exemplary embodiments, the metal-organic interface 30 in Figure 1A may be the interface of an exemplary package substrate 40 representing the electronic device in Figure 1B. The package substrate 40 is an 8-layer high-density interconnect (HDI) substrate having two build-up layers 34 on either side of a core stack 32 having four circuit layers (referred to as a 2+4+2 (2 build-up + 4 core layers + 2 build-up layers) stack). The core stack 32 may be made of BT (bismaleimide triazine) epoxy with embedded glass fibers separating the copper interconnect wires from the plated through-hole (PTH) vias of the core. The build-up layers 34 on either side of the core stack 32 may also contain an organic dielectric material (such as parylene) to separate the copper interconnect structures within these layers (e.g., interconnect wires, interlayer vias, bond pads, etc.). In some embodiments, the BT epoxy core stack 32 may be fabricated first, and then the build-up layers 34 may be formed sequentially (e.g., by deposition, photolithography patterning, etching, etc.) on the top and bottom. As shown by the dashed circle in Figures 1A and 1B, the metal-organic interface 30 in Figure 1A may be located anywhere on the package substrate 40. Although the interface 30 is described as being part of the package substrate 40, as previously explained, the interface 30 can be part of any electronic device, such as the back-end structure of an IC die.

[0015]

[0018] In the embodiments shown in Figures 1A and 1B, the material of the metal structure 10 is a conductive interconnect material (e.g., copper). The material of the organic layer 20 depends on the location of the interface 30 within the package substrate 40. For example, if the interface 30 is an interface within the core stack 32, the organic layer 20 may be the organic material used for the core (e.g., BT epoxy). Alternatively, if the interface 30 is an interface within the build-up layer 34, the organic layer 20 may be the organic material used for the build-up layer (e.g., parylene, ABF, or any other suitable organic material). For brevity, improvements in the adhesive strength of the copper-parylene interface are described herein. In other words, in the following discussion, the metal structure 10 is made of (or contains) copper, and the organic layer 20 is made of (or contains) parylene. Parylene is a collective term for a set of polymers having the chemical formula (C8H8)n, where n represents the number of repeating monomer units. Note that these materials (e.g., copper and parylene) are illustrative examples only. Generally, the organic layer 20 may include any material such as polymers, dielectrics, epoxy (e.g., underfill epoxy, overmolded epoxy, etc.), or composite materials consisting of two or more of the above materials. For example, it is a composite material of glass fiber, epoxy resin, and silica filler material having a layer of copper on top, commonly called a copper-clad laminate. The metal structure 10 may include any metal or alloy such as copper, gold, titanium, or aluminum. Furthermore, the metal structure 10 of the interface 30 may be any part of the interconnection structure on the package substrate 40 (e.g., interconnection lines, power planes, ground planes, interlayer vias, PTHs, bond pads, etc.).

[0016]

[0019] Referring to Figure 1A, in the method of the present disclosure, after the metal structure 10 has been formed by any suitable method, the surface of the metal layer is treated with a chemical composition before forming the organic layer 20 on the surface of the metal structure 10 (e.g., by depositing a layer of organic material). The chemical composition reacts with the metal to form a single layer coating 15 of the chemical composition (e.g., a thin layer of the reactant compound) on the surface of the metal structure 10. This single layer coating 15 of the chemical composition enhances the adhesion of the organic layer 20 that is subsequently formed (e.g., deposited) on the metal structure 10 on the single layer coating 15. It should be noted that when the metal surface is treated with the chemical composition, in some cases the chemical composition itself may not deposit on the surface to form a single layer coating. Instead, the chemical composition may react with the metal surface to form a single layer coating, where the functional portion of the chemical composition forms the single layer coating or is contained within the single layer coating. Furthermore, as those skilled in the art will recognize, the coating material may react with the substrate material (e.g., the substrate metal) and its composition may change over time. It should be noted that, as used herein, the term “single-layer coating of a chemical composition” is used to refer to all of the above scenarios. In other words, the term “single-layer coating of a chemical composition” broadly refers to a single-layer coating having (a) a composition substantially made from the chemical composition (on which the substrate is treated), (b) a composition containing a functional part of the chemical composition, and (c) a composition that is a product of a chemical reaction between the chemical composition and the substrate material. In some embodiments, the composition of the single-layer coating 15 can be determined using energy dispersive spectroscopy (EDS) or other known techniques. A “single-layer coating” refers to a single layer of molecules or atoms deposited on a surface to form a uniform, thin coating. This type of coating is typically very thin on a nanometer scale and consists of a densely packed, self-assembled layer of molecules or atoms. When a metal surface is treated with a chemical composition, the molecules or atoms can be organized into a uniform layer due to intermolecular forces.

[0017]

[0020] The metal structure 10 can be formed by any process used to form a metal structure on an underlying substrate (e.g., an IC manufacturing process). For example, one exemplary process for forming the metal structure 10 on an underlying substrate (e.g., the core stack 32 in Figure 1B) may include depositing a layer of metal (e.g., copper) onto the substrate (e.g., by chemical vapor deposition: CVD, etc.) and patterning the metal layer into a desired circuit pattern using a conventional photolithography process. The organic layer 20 can also be formed on the metal structure 10 by any known process used to manufacture the package substrate 40 (e.g., deposition, plating, spraying, etc.). Before forming the organic layer 20, a single-layer coating 15 of a chemical composition is formed or deposited on the surface of the metal structure, for example, by vapor deposition. Generally, the single-layer coating 15 can be about 1 to 30 angstroms thick. In some embodiments, the single-layer coating 15 can be between about 1 and 10 angstroms thick. Note that the "thickness" of the single layer can be the length of the molecules of the chemical composition. It should be noted that the single-layer coating 15 does not have to completely cover the treated metal surface. Instead, there may be areas on the metal surface that do not have a single-layer coating (or have minimal coating). In other words, the coverage of the single-layer coating on the substrate does not have to be 100%. When measuring the "thickness" of the single-layer coating using measurement techniques such as ellipsometry, the resulting thickness may be between 0 and 100% of the molecular length, depending on the coverage of the single-layer coating on the substrate.

[0018]

[0021] Vapor deposition is a controlled process that can provide a stable environment for forming a uniform, self-assembled monolayer coating 15 of a chemical composition on the surface of a metal structure 10. The monolayer coating 15 can provide reactivity and functionality to the surface of the metal structure 10 by forming durable covalent bonds between the functionalized portions of the chemical composition and the underlying metal structure 10. As is known to those skilled in the art, the physical and chemical properties of a solid surface are primarily determined by the outermost layer of atoms or chemical groups. As a result, by coating the surface of the metal structure 10 with a monolayer coating 15 of a chemical composition, the metal structure 10 can form strong bonds with the molecules of an organic layer 20 deposited (or otherwise formed) on it. Surface modification of metal surfaces is known (see, e.g., Sagiv; J.Am.Chem.Soc.; January 1, 1980; 102; pp. 92-98), but no successful coupling agents for metals that form hydrolytically or mechanically unstable surface oxides have been previously disclosed. No chemical compositions suitable for bonding between a metal surface and an organic layer have been previously disclosed either.

[0019]

[0022] The chemical compositions used in this disclosure for treating metal surfaces are coupling agents suitable for enhancing the adhesion of organic materials to mechanically unstable metal surfaces at the metal-organic interface (e.g., electroless copper, physically vapor-deposited (PVD) copper, electroplated copper, electroplated gold, PVD gold, etc.). The disclosed chemicals are based on the chemical properties of the substrate. The chemical compositions enable the coating of numerous metal substrates on both smooth and rough surfaces, providing excellent post-deposit film stability. The functional and reactive groups of the selected chemical compositions enable various bonding mechanisms for the metal and organic materials to bond. The disclosed chemical compositions increase the bonding strength between parylene structures and copper structures on the substrate. These bonds are expected to fix the functional groups of the chemical composition between the metal surface and form in-plane crosslinks, increasing the stability of the single-layer stability.

[0020]

[0023] Table 1 lists some of the chemical compositions that can be used as effective coupling agents for metal-organic interfaces (interface 30 in FIG. 1A). These compositions may be particularly suitable for increasing the adhesion of organic materials (such as parylene) to the surface of copper metal structures 10 formed by different processes such as electroless copper, physical vapor deposition (PVD) copper, and electroplated copper, for example. It should be noted that the list in Table 1 is not an exhaustive list, and suitable chemical compositions for the present disclosure may include other similar compositions. In general, the selected chemical composition may have a boiling point below about 250°C at a pressure between about 0.1 to 10 Torr. [Table 1]

[0021]

[0024] It has been determined that treating the surface of metal structure 10 by vapor phase deposition using vapor of at least one of the above chemical compositions forms a single-layer coating 15 of the chemical composition on the treated metal surface that increases the adhesive strength of interface 30 when organic material 20 is deposited on the treated surface. In the vapor phase, the process functions with individual molecules to form an ultra-thin single-layer coating 15 of the chemical composition on the metal structure 10. The above chemical compositions are selected such that they do not undergo head-to-tail reaction, and therefore do not polymerize to form a thick layer. For some chemicals, in the liquid phase, these chemicals may tend to aggregate and form a non-uniform layer. Vapor deposition has the additional advantage that it can diffuse through small openings as the size of device features decreases.

[0022]

[0025] The specific chemical composition selected for any given application depends on the materials forming the interface, process conditions, etc., such as the materials and process conditions constituting the metal structure 10 and the organic layer 20. The chemical compositions disclosed above have been determined to be effective in improving adhesion to both smooth and rough surfaces and providing good post-deposition film stability. While the disclosed chemical compositions are expected to be suitable for a wide variety of materials used as metal structures 10 and organic layers 20 in electronic devices, they have been determined to be particularly effective in enhancing adhesion between parylene-containing organic layers 20 and copper-containing metal structures 10. These chemical compositions are also expected to be effective in increasing the adhesive strength between any metal, including unstable oxides, and polyamides. The functional and reactive groups of the disclosed chemical compositions are thought to enable various bonding mechanisms between the metal structure 10 and the organic layer 20. The formed bonds are expected to facilitate in-plane crosslinking, fixing the functional groups of the chemical composition between the metal surface and increasing monolayer stability.

[0023]

[0026] In some embodiments, the surface of the metal structure 10 may be treated with one or more of the above chemical compositions using a vapor deposition process. In some embodiments of an exemplary vapor deposition process, vapor of a desired chemical composition is introduced into a process chamber that supports therein a substrate having the exposed metal structure 10 (e.g., the package substrate 40 of FIG. 1B). A process chamber of any suitable semiconductor processing apparatus may be used for the vapor phase silane deposition process. For example, the process chamber of the processing apparatus described in any one of U.S. Pat. Nos. 7,727,588; 8,252,375; 8,361,548; 10,147,617; 10,319,612; 10,490,431; 11,367,640; 11,444,053; 11,335,662; 11,296,049; 11,456,274; and 11,465,225 may be used. Each of these references is incorporated herein in its entirety. In some embodiments, the temperature and pressure of the vapor within the process chamber may be adjusted to maintain the applied chemical composition in its vapor phase. The exact values (or ranges) of temperature and pressure for maintaining the chemical composition in its vapor phase depend on the composition being applied and the application (e.g., the materials involved, etc.). In general, the metal structure 10 may be exposed to the vapor for any desired period of time (e.g., from about 3 minutes to about 2 hours). In some embodiments, the metal structure 10 may be exposed to the vapor of the chemical composition for a period or duration of between about 10 to 30 minutes, or between about 15 to 20 minutes. In some embodiments, longer periods of time may be used. A monolayer coating 15 of the chemical composition may be formed during the initial stage of exposure (e.g., the first 10 to 20 minutes). Increasing the exposure time can increase the density of the formed monolayer coating 15.

[0024]

[0027] Figure 2A is a flowchart of an exemplary process 100A that may be used to process a substrate on which a metal structure 10 is formed. One or more substrates having the metal structure 10 may be placed in a process chamber. The surface of the metal structure 10 and / or the substrate may be prepared for vapor treatment (step 110). In some embodiments, surface preparation may include, for example, a wet process such as a dilute acid bath, or exposure of the surface to a dry active plasma to remove contaminants and native oxides from the surface. The process chamber may then be purged to remove oxygen and moisture (step 120). In some embodiments, as described in detail, for example, U.S. Patent Nos. 7,727,588 and 8,252,375, the process chamber may undergo one or more consecutive vacuum and nitrogen purge cycles to create a relatively oxygen- and moisture-free environment within the process chamber. In some embodiments, heated nitrogen gas may be used. For example, in some embodiments, the process chamber may be exposed to a vacuum (e.g., about 10 Torr for 2 minutes) and then to room temperature nitrogen gas or heated nitrogen gas (e.g., at 150°C) once or multiple times to remove moisture and oxygen from the chamber. If heated nitrogen gas is used, the preheated nitrogen gas can also heat the surface of the substrate. In embodiments where it is desirable not to heat the substrate before the oxygen level is reduced to below an acceptable level (e.g., <100 ppm), room temperature (or cooled) nitrogen gas may be used. Next, a vapor of the desired chemical composition (e.g., compositions listed in Table 1) may be introduced into the process chamber (step 130). The chemical vapor injected into the chamber may be vaporized from the chemical composition liquid and then introduced into the process chamber, or it may be transported via an inert carrier gas (e.g., nitrogen). For example, heated nitrogen gas may be bubbled through the chemical composition liquid and then introduced into the process chamber. In some embodiments, the chemical composition vapor of step 130 may be vaporized from a pure liquid chemical, or from a solid or semi-solid chemical.As previously described, the exposure time of the substrate to the chemical composition vapor can be varied according to the reaction rate of the substrate to achieve a dense monolayer film. The temperature and pressure of the chamber can also be adjusted to keep the chemical composition in the gas phase. After the metal structure 10 has been exposed to the chemical composition vapor for a sufficient amount of time, the chamber can be evacuated to remove excess chemical vapor from the chamber (step 140). In some embodiments, as in step 120, the process chamber may be alternately exposed to vacuum and nitrogen gas once or more times to completely remove the chemical vapor from the chamber. In some embodiments, the chamber can then be ventilated to the atmosphere (step 150). After the metal structure 10 has been treated with the chemical composition vapor, the organic layer 20 can be formed on the metal structure 10 treated by any suitable process known in the art (e.g., deposition). In some embodiments, the conformal coating of the organic layer 20 can be deposited on the substrate surface having the metal structure 10. By treating the surface of the metal structure with the chemical composition vapor in step 130, a monolayer coating 15 of the chemical composition is formed on its surface, which enhances the adhesion of the organic layer to the metal surface.

[0025]

[0028] In some embodiments, the process in Figure 2A can be used in a process apparatus having a preheated chamber. In other embodiments of the process apparatus, the process chamber and / or substrate may be heated from room temperature to the process temperature before exposure to the chemical composition vapor (step 130), and then cooled to a temperature safe for exposure to atmospheric oxygen (typically <100°C). Such a process may be used to process oxygen-sensitive metals (e.g., copper). Figure 2B is a flowchart of another exemplary process that may be used. The process steps in Figure 2B, which are similar to those described with reference to Figure 2A, are similarly numbered and not described in detail. In process 100B of Figure 2B, after purging the chamber as described with reference to Figure 2A (step 120), the process chamber and / or substrate may be heated to the process temperature (step 125). The process temperature (e.g., 150°C, 175°C, 200°C, etc.) may depend on the process apparatus used. The metal surface is then treated with the vapor of the selected chemical composition (step 130). Next, the substrate is cooled to a safe unloading temperature, for example, below approximately 100°C (step 135). The chamber may then be evacuated (step 140) and ventilated (step 150). Note that the processes shown in Figures 2A and 2B are illustrative and many modifications are possible. For example, the steps described may be performed in a different order, and some steps may be omitted. For example, in process 100B in Figure 2B, steps 135 and 140 may be interchangeable (for example, step 140 may be performed before step 135). In some embodiments, processes 100A and 100B may be part of a larger process. For example, in some embodiments, process 100A or 100B may be incorporated into a process used to deposit organic material onto a metallic structure.

[0026]

[0029] When the metal structure 10 is exposed to the chemical composition vapor in step 130, a single-layer coating 15 of the chemical composition may be formed (or deposited) on the surface of the metal structure 10. The single-layer coating 15 may bond to the metal structure using any mechanism, but in some embodiments in which the metal structure 10 contains copper, the single-layer coating may bond to the metal structure 10 using one or more of the mechanisms listed in Table 2 below. [Table 2]

[0027]

[0030] On the surface of the copper metal structure 10, Cu atoms or CuO molecules can be arranged, resulting in different bonding mechanisms as outlined above. A unique feature of the selected chemical compositions is that they can form covalent bonds in oxidized regions, or chelate bonds in regions where the native oxide has been removed and only copper remains. The orientation of the molecules can change from one point to another on the surface, but the molecules still bond. In some embodiments, each of these selected molecules utilizes all of the bonding mechanisms at various locations on the surface.

[0028]

[0031] By treating the surface of the metal structure 10 using the disclosed process, the adhesion between the metal structure 10 and the organic layer 20 in the electronic device can be improved. In particular, a single-layer coating 15 of the chemical composition formed between the metal surface and the organic layer can improve the interfacial adhesion of the metal-organic interface. This improvement in adhesion can lead to a reduction (or elimination) of delamination after etching from the top and sidewalls of the metal-organic interface, which causes interfacial fracture and reliability problems in the electronic device. Since the increase in adhesion is achieved without increasing the surface roughness of the metal structure 10, signal loss can also be eliminated.

[0029]

[0032] Although the disclosed process is described with reference to an electronic device, this is for illustrative purposes only. As will be recognized by those skilled in the art, embodiments of the disclosed method may also be used for other applications. For example, embodiments of the disclosed method may also be used to promote adhesion of metal-organic interfaces in devices used in drug delivery, drug absorption, gas separation, lithium-ion batteries, CO2 capture, medical sensors, biological markers, wearable devices, and the like. The disclosed processing method may be incorporated into any suitable process apparatus (e.g., process oven, deposition system, coating machine, etc.). Furthermore, although some process steps have been disclosed in the above description with reference to specific embodiments, those skilled in the art will recognize that these are for illustrative purposes only and that these steps are applicable to all disclosed embodiments. Other embodiments of the disclosed method will be apparent to those skilled in the art in consideration of the disclosure herein.

Claims

1. A method for improving the adhesion of metal-organic interfaces in electronic devices, To provide a substrate on which a metal structure is formed, To form a single layer coating of a chemical composition on the surface of the metal structure, the surface of the metal structure is treated with the vapor of the chemical composition, wherein the chemical composition is (i.) 2-hydroxyethyl methacrylate phosphate, (ii.) Vinylphosphonic acid, (iii.) N-[3-(dimethylamino)propyl]methacrylamide, (iv.) 2-(diethylamino)ethyl methacrylate, (v.) 2-(dimethylamino)ethyl methacrylate, (vi.) 2-aminoethyl methacrylate hydrochloride, or (vii.) 2,3-Epoxypropyl methacrylate Processing that includes at least one of the following, The process involves treating the surface of the metal structure and then coating the treated surface with an organic material, wherein the metal-organic interface between the treated surface of the metal structure and the coated organic layer has improved adhesion. Methods that include...

2. The method according to claim 1, wherein the single-layer coating of the chemical composition is about 1 to 10 angstroms thick.

3. The method according to claim 1, wherein the chemical composition has a boiling point below about 250°C at a pressure between about 0.1 and 10 Torr.

4. The method according to claim 1, wherein providing the substrate comprises providing the substrate in a process chamber, and the method further comprises purging oxygen or moisture from the process chamber before treating the surface of the metal structure with the vapor of the chemical composition.

5. The method according to claim 4, further comprising treating the surface of the metal structure with the vapor of the chemical composition, and then purging the vapor of the chemical composition from the process chamber.

6. The method according to claim 1, wherein the metal structure includes copper.

7. The method according to claim 6, wherein the organic material comprises parylene.

8. The method according to claim 1, wherein the substrate is part of a package substrate.

9. The method according to claim 1, wherein the metal structure is an interconnection structure for the electronic device.

10. The method according to claim 9, wherein the interconnection structure is one of an interconnection line, a power plane, a ground plane, a via, or a plated through-hole.

11. A method for improving the adhesion of metal-organic interfaces in electronic devices, To provide a substrate having a copper interconnection structure, To form a single-layer coating of a chemical composition on the surface of the copper interconnect structure, the surface of the copper interconnect structure is treated with the vapor of the chemical composition, wherein the chemical composition is (i.) 2-hydroxyethyl methacrylate phosphate, (ii.) Vinylphosphonic acid, (iii.) N-[3-(dimethylamino)propyl]methacrylamide, (iv.) 2-(diethylamino)ethyl methacrylate, (v.) 2-(dimethylamino)ethyl methacrylate, (vi.) 2-aminoethyl methacrylate hydrochloride, or (vii.) 2,3-Epoxypropyl methacrylate Processing that includes at least one of the following, The process involves treating the surface of the copper interconnect structure and then coating the treated surface with parylene, wherein the metal-organic interface between the treated surface of the copper interconnect structure and the coated parylene has improved adhesion. Methods that include...

12. The method according to claim 11, wherein coating the treated surface with parylene includes depositing the parylene on the coated surface.

13. The method according to claim 11, wherein the substrate is part of a package substrate, and the copper interconnect structure is one of interconnect lines, power planes, ground planes, vias, or plated through-holes.

14. The method according to claim 11, wherein providing the substrate comprises providing the substrate in a process chamber, and the method further comprises purging oxygen or moisture from the process chamber before treating the surface of the copper interconnect structure with the vapor of the chemical composition.

15. The method according to claim 14, further comprising treating the surface of the copper interconnect structure with the vapor of the chemical composition, and then purging the vapor of the chemical composition from the process chamber.

16. An electronic device having a metal-organic interface, A substrate having a metallic structure, A single-layer coating of a chemical composition formed on the surface of the metal structure, wherein the chemical composition is (i.) 2-hydroxyethyl methacrylate phosphate, (ii.) Vinylphosphonic acid, (iii.) N-[3-(dimethylamino)propyl]methacrylamide, (iv.) 2-(diethylamino)ethyl methacrylate, (v.) 2-(dimethylamino)ethyl methacrylate, (vi.) 2-aminoethyl methacrylate hydrochloride, or (vii.) 2,3-Epoxypropyl methacrylate A single-layer coating comprising at least one of the following, An organic material layer disposed on the single-layer coating of the chemical composition and An electronic device equipped with the following features.

17. The device according to claim 16, wherein the single-layer coating of the chemical composition is about 1 to 10 angstroms thick.

18. The device according to claim 16, wherein the single-layer coating of the chemical composition between the metal structure and the organic material layer improves the adhesion of the metal-organic interface.

19. The device according to claim 16, wherein the metal structure contains copper and the organic material contains parylene.

20. The device according to claim 16, wherein the metal structure is one of an interconnection line, a power plane, a ground plane, a via, or a plated through-hole.

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