Increasing the adhesion of metal-organic interfaces through silane vapor treatment

Abstract

Methods for improving the adhesion of metal-organic interfaces in electronic devices include: providing a substrate having a metal structure, depositing a monolayer of the selected silane composition on the surface of the metal structure using a vapor of the selected silane composition, and coating the surface with an organic material.

Description

Technical Field

[0001] This disclosure relates to a method for improving the adhesion strength of metal-organic interfaces in electronic devices. Background Technology

[0002] The manufacturing process of electronic (or photonic) devices consists of a series of sequential steps that create circuitry on a wafer or panel (collectively referred to herein as a substrate) of materials such as semiconductor wafers, glass panels, printed circuit boards, organic / ceramic substrates, etc. Defects introduced during the manufacturing process from any source reduce the yield of the resulting devices. One cause of defects is insufficient adhesion at the metal-organic interface of the device. Electronic devices (e.g., packaging substrates, integrated circuit chips, optoelectronic devices, etc.) include numerous metal-organic interfaces. The adhesion between the metal components (e.g., interconnects, drop pads, vias, etc.) and the organic components (e.g., dielectric materials, molding compounds, underfill materials, etc.) at the metal-organic interface can be compromised for a variety of reasons. These include, for example, the quality / structure of the materials at the interface, embedded particles / residues (debris, chemicals, etc.) at the interface, high thermomechanical interfacial forces (e.g., due to CTE mismatch), etc. Poor adhesion between the metal (e.g., copper pads) and the organic (e.g., dielectric) at the interface can introduce defects (e.g., delamination, cracks, etc.) at the interface and lead to reduced device yield and / or reliability. A robust metal-organic interface ensures that downstream processes (e.g., chemicals and / or process conditions used during downstream processes) do not degrade the adhesion strength of the interface. Furthermore, the miniaturization of electronic devices necessitates the miniaturization of integrated circuit (IC) substrates (e.g., printed circuit boards (PCBs)), which consist of organic material layers (often referred to as laminates or dielectric layers, containing, for example, polymers, laminates, such as Ajinomoto laminated films (ABF), etc.) and metal (e.g., copper) interconnect circuit systems (e.g., lines, planes, vias, etc.). To fabricate highly intricate copper circuit systems with small linewidths and space widths for next-generation electronic devices, increased adhesion between the copper and dielectric layers is required.

[0003] Current methods for improving adhesion 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, before depositing the dielectric layer, the surfaces of the metal interconnects are modified by, for example, etching, plasma ablation, etc., to improve the 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, and etching / ablation may require additional cleaning steps and / or cause debris from the roughening process to be redeposited and embedded on the interface. The methods for improving adhesion disclosed herein can mitigate at least some of the aforementioned drawbacks. However, the scope of this disclosure is defined by the claims, and not by the ability to solve any problem. Summary of the Invention

[0004] An embodiment of a method for improving the interfacial strength of a metal-organic interface in an electronic device is disclosed. In some embodiments, the method for improving the adhesion of the metal-organic interface in the electronic device includes providing a substrate having a metallic structure. The method may further include depositing a monolayer of a selected silane composition on the surface of the metallic structure with a vapor of a selected silane composition, and coating the treated surface with an organic material.

[0005] In one embodiment, a method for improving the adhesion of metal-organic interfaces in electronic devices is disclosed. The method may include providing a substrate having a copper interconnect structure, and depositing a monolayer of a silane composition on the surface of the copper interconnect structure by vapor deposition. The silane composition may include (a) at least one primary or secondary amino group and at least one alkoxysilyl group, (b) the alkoxysilyl group may be one of ethoxy, methoxy, butoxy, propoxy, or isopropoxy, (c) the alkoxysilyl group may be attached with one to three alkoxy groups, and (d) a boiling point below about 250°C at a pressure of about 0.1-10 Torr. The method may further include depositing ABF on the surface of the copper interconnect structure after depositing the monolayer of the silane composition.

[0006] In another embodiment, a method for improving the adhesion of metal-organic interfaces in electronic devices is disclosed. The method may include providing a substrate on which a metal structure is formed, and treating the surface of the metal structure with a vapor of a silane composition. The silane composition may include at least one of the following: (i.) N-(2-aminoethyl)-3-aminopropyltrimethoxysilane (AE-APTMS), (ii.) N,N'-bis[(3-trimethoxysilyl)propyl]ethylenediamine (TMSP-ED), (iii.) bis(3-trimethoxysilylpropyl)amine (TMSPA), (iv.) 3-mercaptopropyltrimethoxysilane (MPTMS), (v.) 25% aqueous solution of N-(2-aminoethyl)-3-aminopropylsilane triol (AE-APST), (vi.) 3-thiocyanate (vii.) N-(6-aminohexyl)aminomethyltrimethoxysilane, (viii.) 1,3-bis(3-aminopropyl)tetramethyldisiloxane, (ix.) bis[3-(triethoxysilyl)propyl]disulfide, 90% (TESPDS), (x.) cysteine, (xi.) 3-aminopropanethiol, (xii.) aminoethylaminopropyl / methylsilsesquioxane aqueous solution, (xiii.) aminopropylsilsesquioxane aqueous solution (APS), (xiv.) (2-diethylphosphine) (xv.) (2-Diethylphosphorylethyl)methyldiethoxysilane, (xvi.) N-(2-aminoethyl)-3-aminopropyltriethoxysilane, (xvii.) 3-(m-aminophenoxy)propyltrimethoxysilane, (xviii.) N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, (xix.) N-(2-aminoethyl)-3-aminoisobutylmethyldimethoxysilane, (xx.) N-(2-aminoethyl)-3-aminoisobutyldimethylmethoxysilane, (xxi.) 4-amino Butyltriethoxysilane, (xxii.) (aminoethylaminomethyl)phenethyltrimethoxysilane, (xxiii.) N-(2-aminoethyl)-3-aminopropylmethyldiethoxysilane, (xxiv.) N-(2-aminoethyl)-11-aminoundecyltrimethoxysilane, (xxv.) N-(6-aminohexyl)aminopropyltrimethoxysilane, (xxvi.) N-(6-aminohexyl)aminopropyltrimethoxysilane, (xxvii.) m-aminophenyltrimethoxysilane, or (xxviii.) m-aminophenyltrimethoxysilane. The method may also include coating the treated surface with an organic material after the surface has been treated.

[0007] In yet another embodiment, a method for improving the adhesion of metal-organic interfaces in electronic devices is disclosed. The method may include providing a substrate having a copper interconnect structure and treating the surface of the copper interconnect structure with a vapor of a silane composition. The silane composition may have a boiling point below about 250°C at a pressure of about 0.1-10 Torr and comprises at least one of the following: (i.) N-(2-aminoethyl)-3-aminopropyltrimethoxysilane (AE-APTMS), (ii.) N,N'-bis[(3-trimethoxysilyl)propyl]ethylenediamine (TMSP-ED), (iii.) bis(3-trimethoxysilylpropyl)amine (TMSPA), (iv.) 3-mercaptopropyltrimethoxysilane (MPTMS), (v.) 25% N-(2-aminoethyl)-3-aminopropylsilane triol water. Solutions (AE-APST), (vi.) 3-Thiocyanopropyltriethoxysilane, 92% (TCPTES), (vii.) N-(6-aminohexyl)aminomethyltrimethoxysilane, (viii.) 1,3-bis(3-aminopropyl)tetramethyldisiloxane, (ix.) bis[3-(triethoxysilyl)propyl]disulfide, 90% (TESPDS), (x.) cysteamine, (xi.) 3-aminopropanethiol, (xii.) aminoethylaminopropyl / methylsilsesquioxane aqueous solution, (xiii.) aminopropylsilsesquioxane aqueous solution (APS) , (xiv.) (2-diethylphosphorylethyl)triethoxysilane, (xv.) (2-diethylphosphorylethyl)methyldiethoxysilane, (xvi.) N-(2-aminoethyl)-3-aminopropyltriethoxysilane, (xvii.) 3-(m-aminophenoxy)propyltrimethoxysilane, (xviii.) N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, (xix.) N-(2-aminoethyl)-3-aminoisobutylmethyldimethoxysilane, (xx.) N-(2-aminoethyl)-3-aminoisobutyldimethylmethoxysilane, (xx i.) 4-aminobutyltriethoxysilane, (xxii.) (aminoethylaminomethyl)phenethyltrimethoxysilane, (xxiii.) N-(2-aminoethyl)-3-aminopropylmethyldiethoxysilane, (xxiv.) N-(2-aminoethyl)-11-aminoundecyltrimethoxysilane, (xxv.) N-(6-aminohexyl)aminopropyltrimethoxysilane, (xxvi.) N-(6-aminohexyl)aminopropyltrimethoxysilane, (xxvii.) m-aminophenyltrimethoxysilane, or (xxviii.) m-aminophenyltrimethoxysilane. The method may also include coating the treated surface with ABF after the surface has been treated. Attached Figure Description

[0008] The accompanying drawings, which are incorporated herein and form part of this disclosure, illustrate exemplary embodiments and, together with the specification, serve to explain the principles of the disclosure. In these drawings, where appropriate, reference numerals illustrating the same or similar structures, components, materials, and / or elements in different drawings are similarly labeled. It should be understood that various combinations of structures, components, and / or elements are contemplated and are within the scope of this disclosure, in addition to those specifically shown.

[0009] For simplicity and clarity, the accompanying drawings depict the overall structure of the various embodiments. 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. The dimensions of some features may be exaggerated relative to other features (e.g., see [reference needed]). Figure 3B This is to improve the understanding of exemplary embodiments. Those skilled in the art will understand that features in the drawings are not necessarily drawn to scale and, unless otherwise indicated, should not be construed as representing dimensional or proportional relationships between different features in the drawings. Furthermore, even if not explicitly stated, aspects described with reference to one embodiment or drawing may be applied to other embodiments or drawings and may be used with other embodiments or drawings.

[0010] Figure 1A A simplified schematic illustration of the metal-organic interface in electronic devices;

[0011] Figure 1B For including Figure 1A A schematic cross-sectional view of an exemplary electronic device with an interface;

[0012] Figure 2A To process Figure 1A A flowchart of an exemplary method for a metal surface in a metal-oxide interface;

[0013] Figure 2B To process Figure 1A A flowchart of another exemplary method for a metal surface in a metal-oxide interface;

[0014] Figure 3A The results of experiments performed on samples representing exemplary embodiments of the present disclosure are shown; and

[0015] Figure 3B for Figure 3A A schematic representation of the structure of the sample during the test. Detailed Implementation

[0016] All related terms, such as “about,” “substantially,” “approximately,” etc., indicate a possible deviation of ±10% (unless otherwise stated or specified as another degree of deviation). For example, the thickness of a feature disclosed as about “t” units thick (or length, width, depth, etc.) may vary from (t-0.1t) to (t+0.1t) units. In some cases, the specification also provides context for some related terms used. For example, a structure described as substantially flat (e.g., a coating edge) may deviate from being completely flat by ±10%. Additionally, ranges described as varying from 5 to 10 or between 5 and 10 (5-10) include 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, a composition comprising only A, a composition comprising only B, a composition comprising only C, a composition comprising both A and B, a composition comprising both A and C, a composition comprising A, B, and C, etc.

[0017] Unless otherwise defined, all technical terms, symbols, and other scientific terms or terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. Some components, structures, and / or processes described or referenced herein are well understood by those skilled in the art and are typically employed using conventional methods. These components, structures, and processes will not be described in detail hereafter. All patents, applications, published applications, and other publications referenced herein are incorporated in their entirety. If any definition or description set forth in this disclosure is contrary to or otherwise inconsistent with the definitions and / or descriptions in these references, then the definitions and / or descriptions set forth in this disclosure shall govern the definitions and / or descriptions in the references incorporated by reference. None of the references described or referenced herein are to be acknowledged as prior art relative to this disclosure. It should be noted that in this disclosure, the term "electronic device" is used to cover all components and electronic / photonic components (e.g., packaging substrates, printed circuit boards, inserters, integrated circuit chips, etc.).

[0018] The following discussion describes an exemplary method for improving the interfacial adhesion strength of metal-organic interfaces in electronic devices. Figure 1A for Figure 1B A simplified representation of a metal-organic interface 30 of an exemplary electronic device is illustrated. Interface 30 includes a metal structure 10 (e.g., a line, plane, pad, via wall, etc.) on which an organic layer 20 is formed. The organic layer 20 can be formed on the metal structure 10 by any known method used in the manufacture of electronic devices (e.g., deposition, electroplating, growth, spraying, etc.). In an exemplary embodiment, Figure 1A The metal-organic interface 30 can be represented Figure 1BThe interface of an exemplary packaging substrate 40 for an electronic device. The packaging substrate 40 is an 8-layer high-density interconnect (HDI) substrate with two stacked layers 34 on each side of a core stack 32 having four circuit layers (referred to as a 2+4+2 (2 stacked layers + 4 core layers + 2 stacked layers) stack). The core stack 32 may be made of BT (bismaleimide triazine) epoxy resin, in which embedded glass fibers separate the copper interconnects and plated through-hole (PTH) vias of the core. The stacked layers 34 on either side of the core stack 32 may also comprise an organic dielectric material (such as ABF) that separates the copper interconnect structures (e.g., interconnects, interlayer vias, solder pads, etc.) in these layers. In some embodiments, the BT epoxy core stack 32 may be fabricated first, and then the stacked layers 34 may be formed sequentially (e.g., by deposition, photolithographic patterning, etching, etc.) on the top and bottom. Figure 1A and 1B The dashed circle illustrates that Figure 1A The metal-organic interface 30 can be an interface located anywhere on the package substrate 40. Although, as previously described, interface 30 is part of the package substrate 40, interface 30 can be part of any electronic device, such as on the back-end structure of an IC die.

[0019] exist Figure 1A and 1B In the illustrated embodiments, 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 encapsulation substrate 40. For example, if the interface 30 is an interface in the core stack 32, then the organic layer 20 may be an organic material used in the core (e.g., BT epoxy resin). And if the interface 30 is an interface in the stack 34, then the organic layer 20 may be an organic material used in the stack (e.g., ABF or any other stacking material). These materials are merely exemplary. Typically, the organic layer 20 may comprise any material, such as polymers, dielectrics, epoxy resins (e.g., underfill epoxy resin, overmolded epoxy resin, etc.), or composite materials consisting of two or more of the aforementioned materials. For example, a composite of glass fiber, epoxy resin, and silica-filled material with a copper layer on top is commonly referred to as a copper-clad laminate. Furthermore, the metal structure 10 may comprise any metal or alloy, such as copper, gold, titanium, aluminum, etc. Furthermore, the metal structure 10 of the interface 30 can be any part of the interconnect structure (e.g., interconnect lines, power planes, ground planes, interlayer vias, PTHs, pads, etc.) on the packaging substrate 40.

[0020] refer to Figure 1AIn the method of this disclosure, after the metal structure 10 is formed by any suitable method and before the organic layer 20 is formed on the surface of the metal structure 10 (e.g., by depositing an organic material layer), a thin layer (e.g., a monolayer) of suitable silane is formed (e.g., deposited) on the surface of the metal structure 10 to increase the adhesion of the organic layer 20 to the metal structure 10. The metal structure 10 can be formed by any process (e.g., IC manufacturing process) used to form a metal structure on an underlying substrate. For example, on an underlying substrate (e.g., Figure 1B An exemplary process for forming the metal structure 10 on the core stack 32) may include depositing a metal (e.g., copper) layer on a substrate (e.g., by chemical vapor deposition (CVD), etc.) and patterning the metal layer into a desired circuit pattern using conventional photolithography processes. The organic layer 20 may also be formed on top of the metal structure 10 by any known process (e.g., deposition, electroplating, spraying, etc.) used in the fabrication of the packaging substrate 40. Prior to forming the organic layer 20, a silane monolayer may be formed (e.g., deposited) on the surface of the metal structure, for example, by vapor-phase silane deposition. Typically, the deposited silane monolayer may be about 1-30 angstroms thick. In some embodiments, the thickness of the silane monolayer may be between about 1-10 angstroms. It should be noted that the “thickness” of the monolayer may be the length of a silane molecule. The coverage of the monolayer on the substrate may not be 100%, and if the “thickness” of such a film is measured using a measurement technique such as ellipsometry, the derived thickness, based on the percentage coverage of the monolayer on the substrate, may be between 0-100% of the molecular length.

[0021] Vapor-phase silane deposition is a controlled process that provides a stable environment for forming a uniform, self-assembled monolayer silane coating on the surface of a metal structure 10. Functionalized silane monolayer coatings provide reactivity and functionality to the surface of the metal structure 10 by generating persistent covalent bonds between silane molecules 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 atoms or chemical groups of its outermost layer. As a result, coating the surface of the metal structure 10 with a suitable silane monolayer allows the metal structure 10 to form strong bonds with the molecules of the organic layer 20 to be deposited (or otherwise formed) thereon. Although silane surface modification of metal surfaces is known (see, for example, Sagiv; *Journal of the American Chemical Society*; January 1, 1980; 102; 92-98), no successful silane coupling agents have previously been disclosed for forming hydrolyzed or mechanically unstable surface oxides of metals. No suitable silane coupling agents have previously been disclosed for bonding between the metal surface and the organic layer.

[0022] Suitable silane coupling agents for increasing the adhesion strength of metal-organic interfaces may comprise a class of aminosilanes having at least one primary or secondary amino group and at least one alkoxysilyl group. The alkoxysilyl group may be one of ethoxy, methoxy, butoxy, propoxy, or isopropoxy. Furthermore, the alkoxysilyl group may be attached with one to three alkoxy groups. Suitable silane coupling agents of this disclosure may also comprise a class of thiol-containing silanes comprising at least one thiol (SH) group and at least one alkoxysilyl group. Suitable silane coupling agents of this disclosure may further comprise a class of thiocyanate-containing silanes having at least one thiocyanate (SN) group and at least one alkoxysilyl group. In some embodiments, the selected silane composition may have a boiling point below about 250°C at a pressure of about 0.1-10 Torr.

[0023] Table 1 lists the metal-organic interfaces that can be used ( Figure 1A Some of the silane compositions are effective coupling agents for the interface 30. These compositions are particularly suitable for increasing the adhesion between organic stacking materials (e.g., ABF) and the surface of the metal structure 10 formed by various processes, such as electroless copper plating, physical vapor deposition (PVD) copper, electroplated copper, electroplated gold, PVD gold, etc. It should be noted that the list in Table 1 is not an exhaustive list, and suitable silane compositions of this disclosure may include any composition from the above-described categories of aminosilanes, thiol-containing silanes, or thiocyanate-containing silanes. Furthermore, in some embodiments, the selected silane compositions may have a boiling point below about 250°C at a pressure of about 0.1-10 Torr.

[0024] Table 1

[0025]

[0026] Table 1 - Continued

[0027]

[0028] Table 1 - Continued

[0029]

[0030] Table 1 - Continued

[0031]

[0032] It has been determined that vapor treatment of the surface of the metal structure 10 with at least one of the aforementioned silane chemicals (e.g., by depositing a monolayer of the silane composition by vapor deposition) increases the adhesion strength of the interface 30 before forming the organic layer 20 thereon. In the vapor phase, this process works with individual molecules and forms an ultrathin monolayer coating on the metal structure 10. The aforementioned silane chemicals (including those listed in Table 1) have been selected such that they do not react from start to finish and therefore do not polymerize and form thick layers. For some chemicals, in the liquid phase, the chemicals may have a tendency to aggregate and form non-uniform layers. Vapor deposition has the additional benefit of being able to diffuse through small openings as device feature sizes decrease.

[0033] The chemical properties of the silane composition chosen for any particular application depend on the materials forming the interface, process conditions, etc. For example, the materials constituting the metal structure 10 and the organic layer 20, process conditions, etc. These silane chemicals have been found to effectively improve adhesion to both smooth and rough surfaces and provide good post-deposition film stability. Although the disclosed silane chemicals or compositions are expected to be applicable to a variety of materials used as the metal structure 10 and organic layer 20 in electronic devices, they have been found to be particularly effective in increasing the adhesion between the organic layer 20 containing ABF and silicon nitride and the copper-containing metal structure 10. These silane chemicals are also expected to effectively increase the adhesion strength between any metal and polyamide having unstable oxides. It is believed that the functionalization and reactive groups of the disclosed silane chemicals will allow for a variety of bonding mechanisms between the metal structure 10 and the organic layer 20. The bonds formed are expected to be anchored between the silane groups and the metal surface, as well as in-plane crosslinking that increases monolayer stability. Although all the silane chemicals disclosed above are effective for improving the adhesion between the metal structure 10 and the organic layer 20, for the copper-containing metal structure 10, preferred amines may include (in Table 1) silane compositions numbered 1, 2, 3, 5, 7, 8, 9, 11 and 12, and preferred sulfur-containing compositions may include those compositions numbered 4, 6, 11 and 12 in Table 1.

[0034] In some embodiments, a vapor phase silane deposition process can be used to treat the surface of the metal structure 10 with one or more of the silane chemicals described above. In some embodiments of the exemplary vapor phase silane deposition process, a vapor of the desired silane chemical is introduced into a processing chamber that supports a substrate having the exposed metal structure 10 (e.g., Figure 1BThe packaging substrate 40). A processing chamber of any suitable semiconductor processing equipment can be used for the vapor-phase silane deposition process. For example, a processing chamber of the processing equipment described in any of U.S. Patent 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 can be used. Each of these references is incorporated herein by reference in its entirety. In some embodiments, the temperature and pressure of the vapor in the processing chamber can be adjusted to retain the applied silane chemical in its vapor phase. The exact values ​​(or ranges) of temperature and pressure for retaining the silane in its vapor phase depend on the applied silane chemical and the application (e.g., the materials involved, etc.). Typically, the metal structure 10 can be exposed to silane vapor for any desired duration (e.g., from about 3 minutes to 2 hours). In some embodiments, the metal structure 10 can be exposed to silane vapor for a period or time between about 10-30 minutes or about 15-20 minutes. In some embodiments, a longer duration can be used. A silane monolayer can form during the initial phase of exposure (e.g., the first 10-20 minutes). Increasing the exposure time increases the density of the formed monolayer.

[0035] Figure 2AThis is a flowchart of an exemplary process 100A that can 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 processing chamber. The surfaces of the metal structure 10 and / or the substrate may be prepared for silane processing (step 110). In some embodiments, surface preparation may include wet processes, such as a dilute acid bath or exposing the surface to a dry, active plasma to remove contaminants and native oxides from the surface. The processing chamber may then be purged to remove oxygen and moisture (step 120). In some embodiments, as described more in, for example, U.S. Patent Nos. 7,727,588 and 8,252,375, the processing chamber may be subjected to one or more consecutive vacuum and nitrogen purging cycles to create a relatively oxygen-free and moisture-free environment in the processing chamber. In some embodiments, heated nitrogen may be used. For example, in some embodiments, the processing chamber may be subjected to a vacuum (e.g., about 10 Torr for 2 minutes, etc.) and then to room temperature nitrogen or heated nitrogen (e.g., at 150°C) once or multiple times to remove moisture and oxygen from the chamber. If heated nitrogen is used, the preheated nitrogen can also heat the surface of the substrate. In embodiments where it is not desirable to heat the substrate until the oxygen level is reduced to below acceptable levels (e.g., <100 ppm), room temperature (or cooled) nitrogen can be used. The vapor of the desired silane composition (e.g., compositions listed in Table 1) can then be allowed into the processing chamber (step 130). The chemical vapor injected into the chamber can evaporate from the silane solution and then enter the processing chamber, or it can be delivered via an inert carrier gas (e.g., nitrogen). For example, heated nitrogen can be bubbled through a liquid silane with the desired chemical properties and then allowed into the processing chamber. In some embodiments, the silane vapor of step 130 can evaporate from a pure liquid chemical or from a solid or semi-solid chemical. As previously described, the exposure time of the silane vapor to the substrate can be varied depending on the reaction rate of the substrate to obtain a dense monolayer film. The temperature and pressure of the chamber can also be regulated to keep the silane chemical in the gas phase. After the metal structure 10 has been exposed to silane vapor for a sufficient time, the chamber may be evacuated to remove excess chemical vapor from the chamber (step 140). In some embodiments, similar to step 120, the processing chamber may be subjected to vacuum and nitrogen one or more times to completely remove chemical vapor from the chamber. In some embodiments, the chamber may then be vented to the atmosphere (step 150). After treating the metal structure 10 with silane vapor, an organic layer 20 may be formed on top of the treated metal structure 10 by any suitable process known in the art (e.g., deposition, etc.). In some embodiments, a conformal coating of the organic layer 20 may be deposited on the surface of a substrate having the metal structure 10.

[0036] In some embodiments, Figure 2AThis process can be used in processing apparatuses with preheating chambers. In other embodiments of the processing apparatus, the processing chamber and / or substrate may be heated from room temperature to the processing temperature (step 130) prior to silane treatment, and then cooled to a safe temperature for exposure to atmospheric oxygen (typically <100°C). Such processes can be used to process oxygen-sensitive metals (e.g., copper). Figure 2B A flowchart of another exemplary process that can be used. (Refer to the reference...) Figure 2A The described process steps are similar Figure 2B The process steps are similarly numbered and not described in detail. In Figure 2B In process 100B, as referenced Figure 2A After the purge chamber (step 120), the processing chamber and / or substrate can be heated to the processing temperature (step 125). The processing temperature (e.g., 150°C, 175°C, 200°C, etc.) may depend on the processing equipment used. The metal surface is then treated with a vapor of a selected silane (step 130). The substrate is then cooled to, for example, a safe unloading temperature below about 100°C (step 135). The chamber can then be evacuated (step 140) and ventilated (step 150). It should be noted that... Figure 2A and 2B The described process is merely exemplary, and many modifications are possible. For example, the described steps may be performed in a different order, and some steps may be eliminated. For example, in Figure 2B In process 100B, steps 135 and 140 are interchangeable (e.g., 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 for depositing organic materials on a metal structure.

[0037] When the metal structure 10 is exposed to silane vapor in step 130, the silane chemical substance can bond to the surface of the metal structure 10. Although silanes can be bonded to the metal structure using any mechanism, in some embodiments where the metal structure 10 includes copper, the silane chemical substance can be bonded to the metal structure 10 using one or more mechanisms listed in Table 2 below.

[0038] Table 2

[0039]

[0040] The surface of the copper metallic structure 10 can be filled with Cu atoms or CuO molecules, leading to the different bonding mechanisms described above. A unique characteristic of the selected silane chemicals 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. This "bifunctionality" holds true regardless of whether the selected chemicals are amine or thiol functional. The orientation of the molecules can change from one point on the surface to another, but the molecules will still bond. In some embodiments, each of these selected molecules will utilize all the bonding mechanisms at different locations on the surface.

[0041] Adhesion tests (peel tests) were performed to evaluate the effectiveness of treating the exemplary metal structures with the silane chemicals disclosed in Table 1. Tests were conducted using a TMJ peel tester at a peel angle of 90° and a peel rate of 50 mm / min. Table 3 below lists some details of the tested samples.

[0042] Table 3

[0043]

[0044] Referring to Table 3, in the sample labeled “AEAPTMS175C”, the processing chamber (or substrate) was heated to approximately 175°C in a N2 atmosphere and stabilized for a period of time (typically 2–30 minutes). The chamber was then evacuated to basic pressure, and AE-APTMS silane vapor (silane chemical 1 from Table 1) was introduced into the processing chamber, exposing the substrate to the vapor for approximately 90 minutes. Similarly, for the sample labeled “TMSP-ED 175C”, the processing chamber / substrate was heated to 175°C, and the substrate was treated with vapor from silane chemical 2 from Table 1. For the samples labeled “Hot 175°C” and “Hot 200°C”, the substrate was heated to 175°C and 200°C, respectively, held at these temperatures, and cooled without silane treatment. These samples were used as control samples to separate the effects of heating the substrate on surface properties (e.g., through dehydration) from the effects of silane reaction with the substrate surface. The “reference” sample was not subjected to thermal processing or silane treatment and was used as a control sample. The tests included samples with copper layers formed by CCL (copper clad laminate) and samples with copper layers formed by PVD (physical vapor deposition) to determine the effect of the silane composition on the surface of copper layers formed by different methods (e.g., CCL Cu and PVD Cu).

[0045] Figure 3A The results of the peel test were summarized, and Figure 3B The cross-sectional structure of the test samples is illustrated schematically. In these samples, the interface tested is a copper-ABF interface. Figure 3AAs observed, the peel test data demonstrate successful adhesion enhancement of ABF on CCL Cu and PVDCu surfaces. For example, a comparison of test results for silane-treated samples (e.g., “AEAPTMS175C” and “TMSP-ED175C” samples) with untreated samples (e.g., “Reference” samples) and heat-treated samples (e.g., “Heat 175C” and “Heat 200C” samples) indicates that the adhesion strength at the metal-organic interface is increased due to silane treatment. Failure analysis of the samples after testing confirms the prediction and indicates that the silane-treated samples fail due to cohesive failure in the ABF layer, while the untreated samples experience adhesion failure at the copper-ABF interface, thus confirming the effectiveness of the disclosed silane treatment for improving adhesion. Although this paper describes only the results of samples treated with silane chemicals 1 and 2 (Table 1) on copper surfaces at Cu-ABF interfaces, predictions (e.g., based on the structure and chemical properties of the listed silane compositions, metals, organics, etc.) indicate that all of the above-mentioned silane chemicals are expected to effectively improve the adhesion of copper structures to other organic materials (layers, dielectric layers, etc.) used in electronic devices.

[0046] Treating the surface of the metal structure 10 using the disclosed process can increase the adhesion between the metal structure 10 and the organic layer 20 in the electronic device. This improvement in adhesion can lead to a reduction (or elimination) of post-etching delamination from the top and sidewalls of the metal-organic interface (causing interface failure and reliability issues 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.

[0047] Although the disclosed processes are described with reference to electronic devices, they are merely exemplary. As those skilled in the art will recognize, embodiments of the disclosed methods can also be used in other applications. For example, embodiments of the disclosed methods can also be used to enhance adhesion of metal-organic interfaces in devices used in drug delivery, drug absorption, gas separation, lithium-ion batteries, CO2 capture, medical sensors, biomarkers, wearable devices, etc. The disclosed silane processing methods can be incorporated into any suitable processing equipment (e.g., processing furnaces, vapor deposition systems, coating machines, 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 merely exemplary and that these steps are applicable to all disclosed embodiments. Other embodiments of the disclosed methods will be apparent to those skilled in the art in light of the disclosure herein.

Claims

1. A method for improving the adhesion of metal-organic interfaces in electronic devices, comprising: A substrate is provided on which a metallic structure is formed; The surface of the metal structure is treated with a vapor of a silane composition to deposit a silane monolayer on the metal structure, wherein the silane composition comprises at least one of the following: (i.)N-(2-aminoethyl)-3-aminopropyltrimethoxysilane (AE-APTMS), (ii.)N,N'-bis[(3-trimethoxysilyl)propyl]ethylenediamine (TMSP-ED), (iii.) Bis(3-trimethoxysilylpropyl)amine (TMSPA), (iv.) 3-Mercaptopropyltrimethoxysilane (MPTMS), (v.) 25% aqueous solution of N-(2-aminoethyl)-3-aminopropylsilane triol (AE-APST), (vi.) 3-Thiocyanopropyltriethoxysilane, 92% (TCPTES), (vii.)N-(6-aminohexyl)aminomethyltrimethoxysilane, (viii.) 1,3-bis(3-aminopropyl)tetramethyldisiloxane, (ix.) Bis[3-(triethoxysilyl)propyl]disulfide, 90% (TESPDS) (xii.) Aqueous solution of aminoethylaminopropyl / methylsilsesquioxane (xiii.) Aqueous solution of aminopropyl silsesquioxane (APS), (xiv.)(2-diethylphosphorylethyl)triethoxysilane, (xv.)(2-diethylphosphorylethyl)methyldiethoxysilane, (xvi.)N-(2-aminoethyl)-3-aminopropyltriethoxysilane, (xvii.)3-(m-aminophenoxy)propyltrimethoxysilane, (xviii.)N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, (xix.)N-(2-aminoethyl)-3-aminoisobutylmethyldimethoxysilane, (xx.)N-(2-aminoethyl)-3-aminoisobutyldimethylmethoxysilane, (xxi.)4-Aminobutyltriethoxysilane, (xxii.)(aminoethylaminomethyl)phenethyltrimethoxysilane (xxiii.)N-(2-aminoethyl)-3-aminopropylmethyldiethoxysilane, (xxiv.)N-(2-aminoethyl)-11-aminoundecyltrimethoxysilane, (xxv.)N-(6-aminohexyl)aminopropyltrimethoxysilane, or (xxvii.) m-aminophenyltrimethoxysilane, The treatment of the surface of the metal structure includes depositing a monolayer of the silane composition on the treated surface; and After treating the surface of the metal structure, the treated surface is coated 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.

2. The method according to claim 1, wherein the silane composition comprises at least one of the following: (ii.)N,N'-bis[(3-trimethoxysilyl)propyl]ethylenediamine (TMSP-ED), (iii.) Bis(3-trimethoxysilylpropyl)amine (TMSPA), (v.) 25% aqueous solution of N-(2-aminoethyl)-3-aminopropylsilane triol (AE-APST), (vii.)N-(6-aminohexyl)aminomethyltrimethoxysilane, (xxv.)N-(6-aminohexyl)aminopropyltrimethoxysilane, or (viii.) 1,3-bis(3-aminopropyl)tetramethyldisiloxane.

3. The method of claim 1, wherein the monolayer is 1 to 10 angstroms thick.

4. The method according to claim 1, wherein the silane composition has a boiling point below 250°C at a pressure of 0.1-10 Torr.

5. The method of claim 1, wherein providing the substrate comprises providing the substrate in a processing chamber, and the method further comprises purging the processing chamber of oxygen or moisture prior to treating the surface with the vapor of the silane composition.

6. The method of claim 5, further comprising purging the vapor of the silane composition from the processing chamber after treating the surface with the vapor of the silane composition.

7. The method of claim 1, wherein the metal structure comprises copper.

8. The method of claim 7, wherein the organic material comprises ABF.

9. The method of claim 1, wherein the substrate is part of a packaging substrate.

10. The method according to claim 1, wherein the metal structure is the interconnect structure of the electronic device.

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

12. A method for improving the adhesion of metal-organic interfaces in electronic devices, comprising: Provide a substrate with a copper interconnect structure; The surface of the copper interconnect structure is treated with vapor of a silane composition with a boiling point below 250°C at a pressure of 0.1-10 Torr to deposit a silane monolayer on the copper interconnect structure, wherein the silane composition comprises at least one of the following: (ii.)N,N'-bis[(3-trimethoxysilyl)propyl]ethylenediamine (TMSP-ED), (iii.) Bis(3-trimethoxysilylpropyl)amine (TMSPA), (v.) 25% aqueous solution of N-(2-aminoethyl)-3-aminopropylsilane triol (AE-APST), (vi.) 3-Thiocyanopropyltriethoxysilane, 92% (TCPTES), (vii.)N-(6-aminohexyl)aminomethyltrimethoxysilane, (viii.) 1,3-bis(3-aminopropyl)tetramethyldisiloxane, (ix.) Bis[3-(triethoxysilyl)propyl]disulfide, 90% (TESPDS) (xii.) Aqueous solution of aminoethylaminopropyl / methylsilsesquioxane (xiii.) Aqueous solution of aminopropyl silsesquioxane (APS), (xiv.)(2-diethylphosphorylethyl)triethoxysilane, (xv.)(2-diethylphosphorylethyl)methyldiethoxysilane, (xvii.)3-(m-aminophenoxy)propyltrimethoxysilane, (xix.)N-(2-aminoethyl)-3-aminoisobutylmethyldimethoxysilane, (xx.)N-(2-aminoethyl)-3-aminoisobutyldimethylmethoxysilane, (xxi.)4-Aminobutyltriethoxysilane, (xxii.)(aminoethylaminomethyl)phenethyltrimethoxysilane (xxiv.)N-(2-aminoethyl)-11-aminoundecyltrimethoxysilane, or (xxvi.)N-(6-aminohexyl)aminopropyltrimethoxysilane; and After treating the surface of the copper interconnect structure, the treated surface is coated with an organic material, wherein the metal-organic interface between the treated surface of the copper interconnect structure and the coated organic material has improved adhesion.

13. The method of claim 12, wherein coating the treated surface with the organic material comprises depositing the organic material on the treated surface.

14. The method of claim 12, wherein the substrate is part of a package substrate, and the copper interconnect structure is one of an interconnect, a power plane, a ground plane, a via, or a plated through-hole.

15. The method of claim 12, wherein the silane composition comprises at least one of the following: (ii.)N,N'-bis[(3-trimethoxysilyl)propyl]ethylenediamine (TMSP-ED).

16. A method for improving the adhesion of a metal-organic interface in an electronic device, comprising: Provide a substrate with a copper interconnect structure; A monolayer of a silane composition is deposited on the surface of the copper interconnect structure by vapor deposition, wherein the silane composition comprises (a) at least one primary or secondary amino group and at least one alkoxysilyl group, (b) the alkoxysilyl group is one of ethoxy, methoxy, butoxy, propoxy, or isopropoxy, (c) the alkoxysilyl group is attached with one to three alkoxy groups, and (d) a boiling point below 250°C at a pressure of 0.1-10 Torr; and After depositing the monolayer of the silane composition, an organic material is deposited on the surface of the copper interconnect structure, wherein the metal-organic interface between the copper interconnect structure and the deposited organic material has improved adhesion.

17. The method of claim 16, wherein the silane composition comprises at least one of the following: (ii.)N,N'-bis[(3-trimethoxysilyl)propyl]ethylenediamine (TMSP-ED), (iii.) Bis(3-trimethoxysilylpropyl)amine (TMSPA), (v.) 25% aqueous solution of N-(2-aminoethyl)-3-aminopropylsilane triol (AE-APST), (vi.) 3-Thiocyanopropyltriethoxysilane, 92% (TCPTES), (vii.)N-(6-aminohexyl)aminomethyltrimethoxysilane, (viii.) 1,3-bis(3-aminopropyl)tetramethyldisiloxane, (ix.) Bis[3-(triethoxysilyl)propyl]disulfide, 90% (TESPDS) (xii.) Aqueous solution of aminoethylaminopropyl / methylsilsesquioxane (xiii.) Aqueous solution of aminopropyl silsesquioxane (APS), (xiv.)(2-diethylphosphorylethyl)triethoxysilane, (xv.)(2-diethylphosphorylethyl)methyldiethoxysilane, (xvii.)3-(m-aminophenoxy)propyltrimethoxysilane, (xviii.)N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, (xix.)N-(2-aminoethyl)-3-aminoisobutylmethyldimethoxysilane, (xx.)N-(2-aminoethyl)-3-aminoisobutyldimethylmethoxysilane, (xxi.)4-Aminobutyltriethoxysilane, (xxii.)(aminoethylaminomethyl)phenethyltrimethoxysilane (xxiv.)N-(2-aminoethyl)-11-aminoundecyltrimethoxysilane, or (xxvi.)N-(6-aminohexyl)aminopropyltrimethoxysilane.

18. The method of claim 17, wherein the silane composition comprises at least one of the following: (ii.)N,N'-bis[(3-trimethoxysilyl)propyl]ethylenediamine (TMSP-ED).

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