CN110970393A

CN110970393A - Diffusion barrier structure, conductive stack and method for making the same

Info

Publication number: CN110970393A
Application number: CN201811140140.3A
Authority: CN
Inventors: 卫子健; 王伟彦
Original assignee: Individual
Current assignee: Individual
Priority date: 2018-09-28
Filing date: 2018-09-28
Publication date: 2020-04-07
Anticipated expiration: 2038-09-28
Also published as: CN110970393B

Abstract

The invention discloses a diffusion barrier structure, a conductive lamination and a manufacturing method thereof. The conductive lamination comprises a substrate, a diffusion barrier structure and a conductive layer, wherein the diffusion barrier structure is formed between the substrate and the conductive layer, the diffusion barrier structure comprises a discontinuous modified layer and a barrier layer, the discontinuous modified layer is arranged on the substrate, and the discontinuous modified layer is made of a polymer with a hydrophilic group; the barrier layer is arranged on the substrate and the discontinuous modified layer, and the material of the barrier layer at least comprises a self-repairing polymer. The diffusion barrier structure can prevent the diffusion of metal atoms, and prevent the characteristics of the conductive lamination from being degraded or damaged due to the temperature rise during the processing and heat treatment of the conductive lamination.

Description

Diffusion barrier structure, conductive stack and method for making the same

[ technical field ] A method for producing a semiconductor device

The present invention relates to a barrier structure, a conductive stack and a method for fabricating the same, and more particularly, to a diffusion barrier structure, a conductive stack and a method for fabricating the same.

[ background of the invention ]

With the advance of technology, Integrated Circuits (ICs) are continuously moving toward the goal of high density and high transmission efficiency. In order to improve the performance of the integrated circuit, efforts to reduce the width of the conductive lines and the spacing between the conductive lines are actively made, but the resistance capacitance delay (RC delay) effect is also increased. Therefore, in order to reduce the rc delay effect, besides using a material with a low dielectric constant as a dielectric layer, copper with low resistivity and high electron migration resistance is mostly selected as a wire material at present to overcome the rc delay effect.

However, copper has a very high diffusion coefficient and readily diffuses into silicon devices during low temperature processing (240 ℃), resulting in device characteristics degradation or destruction. Therefore, a copper diffusion barrier (copper diffusion barrier) is typically disposed between the copper and the dielectric layer to inhibit copper diffusion and maintain electrical reliability of the device. Most conventional copper diffusion barrier layers use a single transition metal nitride as a material, such as tin and tan, and then form a copper diffusion barrier layer on the dielectric layer by a dry process.

However, tin is prone to columnar structures which provide a rapid diffusion path for copper, and the copper diffusion barrier layer formed by dry processing is typically relatively thick (about 10 nm). According to the International Technology Roadmap for Semiconductors (ITRS), when the line width ratio is less than 16 nm, the cu diffusion barrier layer thickness must be less than 2 nm to avoid significant rc delay. Therefore, the copper diffusion barrier layer in the prior art still needs to be improved.

[ summary of the invention ]

The present invention is directed to a diffusion barrier structure, a conductive stack and a method for fabricating the same.

In order to solve the above technical problem, one of the technical solutions adopted by the present invention is to provide a diffusion barrier structure. The diffusion barrier structure is formed between a substrate and a conductive layer, and comprises a discontinuous modified layer and a barrier layer. The discontinuous modified layer is arranged on the substrate, and the material of the discontinuous modified layer is a macromolecule with hydrophilic groups; the barrier layer is arranged on the substrate and the discontinuous modified layer, and the material of the barrier layer at least comprises a self-repairing polymer.

In order to solve the above technical problem, another technical solution adopted by the present invention is to provide a conductive stack. The conductive laminated layer comprises a substrate, a diffusion barrier structure and a conductive layer, wherein the substrate is provided with a surface; the diffusion barrier structure is arranged on the substrate, the diffusion barrier layer comprises a discontinuous modified layer and a barrier layer, the discontinuous modified layer is arranged on the surface of the substrate, and the material of the discontinuous modified layer is a polymer with hydrophilic groups; the barrier layer is formed on the surface of the substrate and the discontinuous modified layer, and the material of the barrier layer at least comprises a self-repairing polymer; the conductive layer is disposed on the substrate, wherein the conductive layer is isolated from the substrate by a diffusion barrier structure.

In order to solve the above technical problem, another technical solution adopted by the present invention is to provide a method for manufacturing a conductive stack. The method for manufacturing the conductive laminate comprises the following steps: providing a substrate, wherein the substrate is provided with a surface; carrying out surface modification treatment on the surface of the substrate to form a discontinuous modified layer on the surface; and forming a barrier layer on the surface and the discontinuous modified layer; the material of the discontinuous modified layer comprises a polymer with hydrophilic groups, and the material of the barrier layer comprises a self-repairing polymer.

The diffusion barrier structure, the conductive lamination and the preparation method thereof have the beneficial effects that the diffusion barrier structure, the conductive lamination and the preparation method thereof can prevent metal atoms in the conductive layer from diffusing into the substrate through the technical scheme of the 'discontinuous modified layer of the polymer with the hydrophilic group' and the 'barrier layer comprising the self-repairing polymer'.

For a better understanding of the features and technical content of the present invention, reference should be made to the following detailed description and accompanying drawings, which are provided for purposes of illustration and description only and are not intended to limit the invention.

[ description of the drawings ]

FIG. 1 is a schematic cross-sectional side view of a conductive stack according to the present invention.

Fig. 2 is a flow chart of the process for preparing the conductive stack of the present invention.

FIG. 3 is a microscope image of a conductive laminate according to the present invention.

Fig. 4 shows the sheet resistance measurements at different rapid thermal annealing temperatures after the conductive layer is disposed on the substrate in different operation modes.

Fig. 5 shows the sheet resistance measurements at different rapid thermal annealing temperatures after the conductive layer is disposed on the substrate in different operation modes.

[ detailed description ] embodiments

The following description is provided by way of specific embodiments of the present disclosure regarding "diffusion barrier structures, conductive stacks and methods for fabricating the same", and those skilled in the art will appreciate advantages and effects of the present disclosure from the disclosure herein. The invention is capable of other and different embodiments and its several details are capable of modification and various other changes, which can be made in various details within the specification and without departing from the spirit and scope of the invention. The drawings of the present invention are for illustrative purposes only and are not intended to be drawn to scale. The following embodiments will further explain the related art of the present invention in detail, but the disclosure is not intended to limit the scope of the present invention.

It will be understood that, although the terms "first," "second," "third," etc. may be used herein to describe various components or signals, these components or signals should not be limited by these terms. These terms are used primarily to distinguish one element from another element or from one signal to another signal. In addition, the term "or" as used herein should be taken to include any one or combination of more of the associated listed items as the case may be.

Referring to fig. 1, the present invention provides a conductive stack 1, which includes: a substrate 10, a diffusion barrier 20 and a conductive layer 30.

The diffusion barrier 20 is disposed between the substrate 10 and the conductive layer 30, and the diffusion barrier 20 can block the metal atoms in the conductive layer 30 from diffusing into the substrate 10 within a certain temperature range. Therefore, the characteristic degradation or damage of the conductive lamination layer 1 caused by the temperature rise during the processing can be avoided.

The material of the substrate 10 may be an inorganic substrate or an organic substrate, but is not limited thereto. In this embodiment, an inorganic substrate is taken as an example, and the material of the substrate 10 is silicon dioxide. In general, in order to improve the conductive efficiency, copper with high conductivity is used as the material of the conductive layer 30, and therefore, in the present embodiment, the material of the conductive layer 30 is copper, and the description is given below.

Specifically, the diffusion barrier structure 20 includes a discontinuous modified layer 21 and a barrier layer 22. The discontinuous modified layer 21 is disposed on the surface 11 of the substrate 10, and after the discontinuous modified layer 21 is disposed on the substrate 10, a micro-rough surface 211 with a slight height difference is formed above the substrate 10 instead of a flat surface.

The micro-rough surface 211 is formed because the surface 11 of the substrate 10 is not completely modified. Specifically, the modified layers (e.g., the unmodified regions 5 and 6) are not formed in the partial regions on the substrate 10, and the island-shaped modified layers (e.g., the modified regions 7 and 8) are formed in the partial regions on the substrate 10. Therefore, the

unmodified regions

5 and 6 in which no modified layer is formed and the modified

regions

7 and 8 in which island-shaped modified layers are formed result in a micro-rough surface 211 having a slight step difference above the surface 11 of the substrate 10.

That is, the surface 11 of the substrate 10 is not completely modified, and the modified layer is adsorbed on the surface 11 of the substrate 10 in island form, instead of completely covering the surface 11 of the substrate 10. Therefore, the modified layer provided in the embodiment is referred to as a discontinuous modified layer 21, and the discontinuous modified layer 21 is advantageous for providing the barrier layer 22.

The material of the discontinuous modified layer 21 includes a polymer having a hydrophilic group, for example, the polymer having a hydrophilic group may be a silane having an amino group, and the number of the amino groups may be one to three. For example, the silane having an amine group may be 3-aminopropyltriethoxysilane (3-aminopropyl) triethoxysilane (APTES), N- (3- (trimethoxysilyl) propyl) ethylenediamine (N- (3- (trimethoxysilyl) ethylene), 3-2- (2-aminoethylamino) ethylaminopropyltrimethoxysilane (3-2- (2-aminoethylaminopropyl) Ethylaminopropyltrimethoxysilane (ETAS), or any combination thereof, but is not limited thereto. In a preferred embodiment, the polymer with hydrophilic group is 3-2- (2-aminoethylamino) ethylaminopropyl trimethoxy silane, i.e. the polymer with hydrophilic group is silane with three amino groups.

The barrier layer 22 is disposed on the surface 11 of the substrate 10 and the discontinuous modified layer 21, and is connected to the micro-rough surface 211 having a height difference with the discontinuous modified layer 21. The barrier layer 22 can block the diffusion of the metal atoms in the conductive layer 30 to the substrate 10 in a certain temperature range.

The material of barrier layer 22 includes a Self-healing polymer (Self-healing polymer). The self-repairing polymer may be selected from the group consisting of Polyvinyl alcohol (PVA), Polyvinylpyrrolidone (PVP), Polyacrylic acid (PAA), Polyethylene glycol (PEG), and any combination thereof. In this embodiment, the self-repairing polymer is polyvinyl alcohol.

In another embodiment, the material of the barrier layer 22 includes a catalyst material in addition to the self-healing polymer. The use of the catalyst material facilitates the formation of the conductive layer 30 on the barrier layer 22. In this embodiment, the catalyst material includes a plurality of nano-metal particles, and the nano-metal particles may be nano-palladium particles.

Generally, the conductive stack 1 is processed by high temperature annealing to release internal stress of metal, and at this time, the metal atoms (usually copper atoms) in the conductive layer 30 are more easily diffused to the substrate 10 due to the increased diffusion rate caused by the high temperature. Once the metal atoms diffuse to the diffusion barrier structure 20, a stimulus is generated to the self-repairing polymer, so as to prompt the self-repairing polymer to block the diffusion path of the metal atoms, thereby achieving the effect of blocking the diffusion of the metal atoms. Thus, the diffusion barrier 20 is configured to resist diffusion of metal atoms over a range of temperatures.

Fig. 2 is a flow chart of the process of manufacturing the conductive laminate 1 of the present invention, please refer to fig. 1 and fig. 2. In step S100, a substrate 10 is provided, the substrate 10 having a surface 11.

In step S110, the surface 11 of the substrate 10 is cleaned. In this embodiment, the surface 11 of the substrate 10 is cleaned and organic substances, oxides and ionic compounds attached to the surface 11 are removed according to a standard wet cleaning method (RCAclean). Then, the surface 11 of the substrate 10 is rinsed with deionized water, and dried to maintain the surface 11 of the substrate 10 in a dry state.

Two reagents were used in the standard wet cleaning method, RCA-1 and RCA-2, respectively, RCA-1 comprising ammonia (NH)₄OH), hydrogen peroxide (H)₂O₂) And deionized water (DI), also known as apm (ammonium hydrogen peroxides), which functions to remove organic particulates from surfaces. RCA-2 comprises hydrochloric acid (HCl), hydrogen Peroxide and deionized water, also known as HPM (hydrochloric acid Peroxide mixtures), and is used for removing metal substances on the surface. In this embodiment, the specific cleaning steps are as follows: soaking the substrate 1 in APM solution at 80 deg.C for 20 min, NH₄OH：H₂O₂: the component ratio of DI is 1: 1: 5. in step S120, the surface 11 of the substrate 10 is pretreated, and the substrate 10 is immersed in a pretreatment solution. In this embodiment, the pretreatment solution is composed of pure isopropyl alcohol, and the substrate 10 is immersed in the pretreatment solution for 5 minutes. In other embodiments, the composition of the pre-treatment solution is not limited to pure isopropanol, but may be toluene, acetone, ethanol, isopropanol, or any combination thereof.

Next, a surface modification treatment is performed on the surface 11 of the substrate 10 to form a discontinuous modified layer 21 on the surface 11, wherein the material of the discontinuous modified layer 21 includes a polymer having a hydrophilic group (step S130).

The polymer having a hydrophilic group may be a silane having an amine group. For example, the silane having an amine group may be selected from the group consisting of 3-aminopropyltriethoxysilane, N- (3- (trimethoxysilyl) propyl) ethylenediamine, 3-2- (2-aminoethylamino) ethylaminopropyltrimethoxysilane, and any combination thereof, but is not limited thereto. In a preferred embodiment, the polymer with hydrophilic group is 3-2- (2-aminoethylamino) ethylaminopropyl trimethoxy silane, i.e. the polymer with hydrophilic group is silane with three amino groups.

In the present embodiment, the surface modification treatment is performed by preparing a modification solution, and then immersing the pretreated substrate 10 in the modification solution, wherein the modification solution includes a polymer having a hydrophilic group (step S131). Therefore, after the surface modification treatment, the material of the discontinuous modified layer 21 includes a polymer having a hydrophilic group.

In the surface modification treatment, the substrate 10 is immersed in the modification solution for a time of 0.5 to 5 minutes. In a preferred embodiment, the substrate 10 is immersed in the modifying solution for 1 minute.

Generally, in the conventional wet process for surface modification, if the soaking time of the substrate 10 in the modifying solution is not long enough, the polymer with hydrophilic groups cannot reach complete monolayer chemisorption, but adheres to the surface 11 of the substrate 10 by physical adsorption, and the adhered polymer with hydrophilic groups is washed away after cleaning, so that a smooth and continuous modified layer cannot be formed on the surface 11 of the substrate 10. Therefore, the conventional technique needs to soak the substrate 10 in the modifying solution for 30 minutes to form a continuous modifying layer with a substantial thickness on the surface 11 of the substrate 10, but has the disadvantage of long operation time.

In contrast, in the present embodiment, a continuous modified layer is not necessarily required, the substrate 10 is only required to be soaked in the modified solution for a short time, and once the island-shaped discontinuous modified layer 21 is generated, the barrier layer 22 can be disposed on the substrate 10, thereby achieving the effect of preventing diffusion of metal atoms. Therefore, the present invention requires a short operation time for performing the surface modification treatment (forming the discontinuous modified layer 21).

In this embodiment, the modifying solution is a silane solution, and the silane content in the silane solution is 0.1 volume percent (vol%) to 5 vol%. In a preferred embodiment, the silane content of the silane solution is 1 vol%.

In a preferred embodiment, one of the components of the pre-treatment solution in step S120 is the same as one of the components of the modification solution in step S131. That is, the modifying solution includes a solvent in which the polymer having the hydrophilic group is dispersed, in addition to the polymer having the hydrophilic group, and the solvent in the modifying solution is the same as that in the pretreatment solution. In this embodiment, the pretreatment solution is isopropanol, and the solvent for dispersing the polymer having a hydrophilic group in the modified solution is also isopropanol. In other words, when the substrate 10 is pretreated in step S120, a small amount of isopropanol is adsorbed on the surface 11 of the substrate 10, so that when the substrate 10 is subjected to the surface modification treatment in step S131, the solvent of the modification solution is also isopropanol, which increases the effect of attaching the polymer having hydrophilic groups to the surface 11 of the substrate 10.

In other embodiments, the solvent in the upgrading solution may be toluene, acetone, ethanol, isopropanol, or any combination thereof. In the present invention, toluene, acetone, ethanol and isopropanol are respectively selected as the solvents of the modifying solution, and after the discontinuous modifying layer 21 is formed, the center line average roughness (Ra.) of the micro-rough surface 211 of the discontinuous modifying layer 21 is observed by an Atomic Force Microscope (AFM), and the experimental results are shown in table 1.

Table 1: the substrate is immersed in the modifying solution with different solvent components to prepare the surface roughness of the discontinuous modifying layer.

In the present invention, the average roughness of the center line of the pure substrate 10 is measured to be 0.106 nm as a comparison standard by observing the substrate 10 without the discontinuous modified layer 21 with an atomic force microscope. As can be seen from the results in table 1, the use of different components as the solvent of the modifying solution has an effect on the structure formed by the discontinuous modified layer 21. After comparing different solvent compositions, it can be found that the discontinuous modified layer 21 formed by using isopropanol as the solvent of the modified solution has smaller roughness, which is more beneficial to form the barrier layer 22 on the discontinuous modified layer 21.

In step S132, the substrate 10 is taken out from the modifying solution, and the substrate 10 is rinsed with a rinsing agent to remove the excess modifying solution. In this embodiment, the components of the rinsing agent are the same as those of the solvent of the reforming solution, i.e., the rinsing agent is pure isopropyl alcohol.

In step S133, the substrate 10 is baked to form covalent bonds between the polymer with hydrophilic groups and the surface 11 of the substrate 10, thereby forming the discontinuous modified layer 21. Thus, the surface 11 of the substrate 10 may be made hydrophilic by the discontinuous modified layer 21. In the present embodiment, the substrate 10 is baked by placing the substrate 10 in an oven at 160 ℃.

Then, a barrier layer 22 is formed on the surface 11 of the substrate 10 and the discontinuous modified layer 21, wherein the material of the barrier layer 22 includes a self-repairing polymer. The self-healing polymer is selected from the group consisting of polyvinyl alcohol, polyvinylpyrrolidone, polyacrylic acid, polyethylene glycol, and any combination thereof (step S140).

In the present embodiment, the barrier layer 22 is formed by preparing a polymer solution, and immersing the modified substrate 10 in the polymer solution, wherein the polymer solution comprises a self-repairing polymer (step S141). In this embodiment, the self-repairing polymer is polyvinyl alcohol, i.e., the polymer solution contains polyvinyl alcohol as a component. And the average grain diameter of the self-repairing polymer in the polymer solution is 5 to 15 nanometers.

In another embodiment, the material of the barrier layer 22 includes a catalyst material in addition to the self-healing polymer. Therefore, in step S141A, the barrier layer 22 is formed by preparing a polymer solution, and immersing the modified substrate in the polymer solution, wherein the polymer solution comprises the self-repairing polymer and the catalyst material. In a preferred embodiment, the catalyst material is nano-metal particles. More preferably, the nano metal particles are nano palladium particles.

When the material of the barrier layer 22 includes nano-metal particles, it is advantageous to form the conductive layer 30 on the barrier layer 22. Specifically, in the case of Electroless plating (electro plating), a catalyst is usually required, so the present invention can add nano-metal particles into the barrier layer 22 to be used as a catalyst for depositing the conductive layer 30.

In one embodiment of the present invention, the polymer solution includes nano-palladium particles (hereinafter, abbreviated as PVA-Pd particles) coated with polyvinyl alcohol. The PVA-Pd particles are prepared in the following specific manner: self-repairing polymers (such as polyvinyl alcohol), reaction precursors (such as palladium nitrate), reducing agents (such as formaldehyde) and alkaline solutions (such as sodium carbonate aqueous solution) are sequentially added into continuously stirred deionized water at room temperature to form polymer nanoparticle clusters. The reducing agent can reduce the reaction precursor into zero-valent nano metal particles in an alkaline environment, the self-repairing polymer can be attached to the periphery of the nano metal particles, and the agglomeration and settlement among the nano metal particles can be prevented through the three-dimensional barrier of the self-repairing polymer.

Wherein, by adjusting the weight of the self-repairing polymer and the reaction precursor, the weight ratio of the polyvinyl alcohol to the nano-palladium particles in the PVA-Pd particles (abbreviated as PVA: Pd weight ratio) can be controlled to be between 0.175: 1 to 2: 1. In this example, PVA: the weight ratio of Pd is 0.175: 1. 0.5: 1. 1: 1 and 2: 1 PVA-Pd particles. In a preferred embodiment, the PVA-Pd particles have a PVA: the weight ratio of Pd is 0.5: 1 to 2: 1.

in this embodiment, the PVA-Pd particles in the polymer solution have an average particle size of 5 nm to 20 nm. In a preferred embodiment, when the PVA-Pd particles have a PVA: the weight ratio of Pd is 0.5: 1 to 2: 1, the PVA-Pd particles in the polymer solution have an average particle diameter of 5 to 10 nm. More preferably, when the PVA-Pd particles contain PVA: the weight ratio of Pd is 1: 1, the average particle diameter of the PVA-Pd particles in the polymer solution is 6 to 9 nm.

In step S142, the substrate 10 soaked with the polymer solution is rinsed with deionized water, and a barrier layer 22 is formed on the surface 11 of the substrate 10 and the discontinuous modified layer 21.

In step S150, a conductive layer 30 is formed on the surface of the diffusion barrier structure 20 opposite to the substrate 10. In the present embodiment, a conductive layer 30 is formed on the diffusion barrier 20 by electroless plating to complete the preparation of the conductive stack 1, as shown in fig. 3.

Fig. 3 is a photomicrograph of the conductive stack 1 taken with a Transmission Electron Microscope (TEM), wherein the diffusion barrier 20 (dark gray portion) is disposed between the substrate 10 (gray portion) and the conductive layer 30 (black portion), and the total thickness of the diffusion barrier 20 of the present invention is significantly less than 5 nm as can be seen from the scale on the photomicrograph. Further, the total thickness of the diffusion barrier structure 20 is less than 2 nm.

In order to confirm that the diffusion barrier structure 20 of the present embodiment can effectively prevent the copper atoms in the conductive layer 30 from diffusing to the substrate 10, the Sheet resistance (Sheet resistance) test was performed on the samples 1 to 9 with a four-point probe, the Sheet resistance of each sample at different environmental temperatures was measured, and the degree of diffusion of the copper atoms in the conductive layer 30 was investigated by the change in Sheet resistance, and the results are shown in fig. 4 and 5. Generally, when copper atoms diffuse into the substrate 10, the electrical properties of the conductive layer stack 1 change, and the sheet resistance of the conductive layer stack 1 increases.

In fig. 4, the conductive layer 30 of sample 1 is directly disposed on the substrate 10, i.e., the diffusion barrier structure 20 is not disposed. The conductive layer 30 of samples 2 and 3 was connected to the substrate 10 with the discontinuous modified layer 21, without the barrier layer 22, and the difference between samples 2 and 3 was: the surface modification treatment was performed for 1 minute (sample 2) and 30 minutes (sample 3), respectively. The conductive layer 30 of

samples

4 and 5 is connected to the substrate 10 with the diffusion barrier 20, and the barrier layer 22 only includes a polymer (polyvinyl alcohol) having a hydrophilic group, and does not have nano-metal particles, and the difference between

samples

4 and 5 is that: the surface modification treatment was performed for 1 minute (sample 4) and 30 minutes (sample 5), respectively.

As can be seen from the results of fig. 4, the discontinuous modified layer 21 or the continuous modified layers (samples 2 and 3) disposed between the substrate 10 and the conductive layer 30 can slightly block the diffusion of copper atoms, and the conductive stack 1 having the continuous modified layer has a better diffusion blocking effect than the conductive stack 1 having the discontinuous modified layer 21. However, the formation time required for the continuous reforming layer is long. In addition to the discontinuous modified layer 21 or the continuous modified layer, if a barrier layer 22 (samples 4 and 5) is further disposed between the substrate 10 and the conductive layer 30, i.e., a diffusion barrier structure 20 is disposed between the substrate 10 and the conductive layer 30, the conductive stack 1 has a better diffusion barrier effect. Moreover, the discontinuous modified layer 21 or the continuous modified layer can have a good effect, and the conductive laminated layer 1 still has a stable sheet resistance even if the ambient temperature reaches 500 ℃.

Therefore, the diffusion barrier structure 20 of the present invention can reliably prevent the diffusion of copper atoms from the conductive layer 30 to the substrate 10. In addition, the present invention can perform the surface modification treatment (forming the discontinuous modified layer 21) in a shorter time, i.e., the diffusion barrier structure 20 or the conductive stack 1 has the advantage of short process time.

In addition, the material of the barrier layer 22 may include self-healing polymers and catalytic materials, so that in order to compare the influence of the composition of the barrier layer 22 in the diffusion barrier structure 20 on the diffusion barrier effect, the sheet resistance test is performed on the conductive stack 1 with different compositions of the barrier layer 22. Referring to fig. 5, the conductive layer stack 1 of samples 6 to 9 has a diffusion barrier structure 20, which is different from that shown in fig. 5: PVA as the material of the barrier layer 22: the weight ratio of Pd is 0.175: 1 (sample 6), 0.5: 1 (sample 7), 1: 1 (sample 8) and 2: 1 (sample 9).

As can be seen from the results of fig. 5, the higher the content ratio of the pva in the material of the barrier layer 22, the better the diffusion of the barrier cu atoms, i.e., the sheet resistance of the conductive stack 1 can maintain a stable value at higher ambient temperature. Specifically, when the PVA-Pd particles contain PVA: the weight ratio of Pd is between 0.175: 1 to 2: 1, the conductive laminate 1 can withstand a processing temperature of 400 c. When the PVA-Pd particles contain PVA: the weight ratio of Pd is between 0.5: 1 to 2: 1, the conductive laminate 1 can withstand processing temperatures of 450 c. When the PVA-Pd particles contain PVA: the weight ratio of Pd is 2: 1, the conductive laminate 1 can withstand processing temperatures of 500 c.

In addition, when the material of the barrier layer 22 includes self-repairing polymer and catalyst material, the diffusion barrier structure 20 of the present invention can not only block the diffusion of copper atoms, but also improve the adhesion of the conductive layer 30 on the substrate 10. Therefore, the conductive layer 30 is disposed on the substrate 10 in various manners and subjected to a rapid thermal annealing treatment at a temperature of 400 ℃, and then, the adhesion of the conductive layer 30 to the substrate 10 is tested in two manners as follows.

First, according to a standard ASTM D3359 established by American Society for Testing and Materials (ASTM), a cross cut test (also called a "hundred grid test") is performed to cut a surface into a lattice shape, and then an adhesion test is performed using a special tape to determine the level of film adhesion, which will be referred to as a tape test hereinafter. In addition, the adhesion of the conductive laminate 1 is measured according to the standards of ASTM D4541 and ASTM D7234, hereinafter referred to as adhesion test. The results of the tape test and the adhesion test are shown in table 2.

Table 2: tape testing and adhesion testing of the conductive laminates under different preparation conditions.

From the results in table 2, it can be seen that the diffusion barrier layer 20 of the present invention has a certain adhesion (2.5MPa to 15MPa) after adding the catalyst material, and the conductive layer 30 can be formed directly on the diffusion barrier layer 20 by electroless plating. The conductive layer 30 can be directly formed on the diffusion barrier layer 20 without forming an additional adhesion layer on the diffusion barrier layer 20. Therefore, the diffusion barrier layer 20 of the present invention can simultaneously block the diffusion of metal atoms and adhere to the conductive layer 30.

Further, when the PVA: the weight ratio of Pd is between 0.5: 1 to 1: 1, the adhesion of the conductive layer 30 is 6 to 15 MPa.

[ advantageous effects of the embodiments ]

One of the benefits of the diffusion barrier structure 20, the conductive stack 1 and the manufacturing method thereof provided by the present invention is that the technical solutions of "providing a discontinuous modified layer" and "providing a barrier layer" can be used to solve the defects of the conventional copper diffusion barrier layer, prevent metal atoms in the conductive layer 30 from diffusing to the substrate 10, further increase the processing temperature that the conductive stack can endure, and maintain the electrical characteristics of the conductive stack 1. In addition, the diffusion barrier layer 20 with a small thickness is prepared by a wet process, so that the surface 11 of the substrate 10 can be modified even if the time for surface modification treatment is shortened.

Furthermore, the barrier layer 22 of the present invention may further include catalyst particles, which help to form a conductive layer on the diffusion barrier layer 20 and have good adhesion. And the adhesion effect of the conductive layer 30 can be further optimized by adjusting and controlling the component ratio of the self-repairing polymer and the catalyst particles in the barrier layer 20.

Furthermore, the solvent in the modifying solution of the present invention may be isopropanol, which can form the discontinuous modifying layer 21 in a short time and has a good structure to ensure the effect of surface modification treatment.

Therefore, the diffusion barrier structure 20, the conductive stack 1 and the manufacturing method thereof provided by the present invention can block metal atoms in the conductive layer 30 from diffusing into the substrate 10 through the technical schemes of the "discontinuous modified layer 21 of polymer with hydrophilic group" and the "barrier layer 22 comprising self-repairing polymer".

The disclosure is only a preferred embodiment of the invention and should not be taken as limiting the scope of the invention, so that the invention is not limited by the disclosure of the specification and drawings. Description of the symbols in the drawings

Conductive laminate 1

Substrate 10

Surface 11

Diffusion barrier structure 20

Discontinuous modified layer 21

Micro-rough surface 211

A barrier layer 22

Conductive layer 30

Unmodified regions

5, 6

Modified regions

7 and 8

Claims

1. A diffusion barrier structure formed between a substrate and a conductive layer, the diffusion barrier structure comprising:

the discontinuous modified layer is arranged on the substrate and is made of a polymer with a hydrophilic group; and

and the barrier layer is arranged on the substrate and the discontinuous modified layer, and the material of the barrier layer at least comprises a self-repairing polymer.

2. The diffusion barrier structure of claim 1, wherein the self-healing polymer is selected from the group consisting of polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylic acid, polyethylene glycol, and any combination thereof.

3. The diffusion barrier structure of claim 1, wherein the polymer having hydrophilic groups is a silane having amine groups.

4. The diffusion barrier structure of claim 3, wherein the silane having an amine group is selected from the group consisting of 3-aminopropyltriethoxysilane, N- (3- (trimethoxysilyl) propyl) ethylenediamine (N-, 3-2- (2-aminoethylamino) ethylaminopropyltrimethoxysilane, and any combination thereof.

5. The diffusion barrier structure of claim 1, wherein the material of the barrier layer further comprises a catalyst material.

6. The diffusion barrier structure of claim 5, wherein the catalyst material is nano-metal particles.

7. The diffusion barrier structure of claim 5, wherein the self-healing polymer and the catalytic material in the barrier layer are present in a weight ratio of 0.175: 1 to 2: 1.

8. the diffusion barrier structure of claim 5, wherein the self-healing polymer in the barrier layer encapsulates the catalytic material.

9. The diffusion barrier structure of claim 1, wherein the total thickness of the diffusion barrier structure is less than 5 nm.

10. A conductive laminate, comprising:

a substrate having a surface;

the diffusion barrier structure is arranged on the substrate, the diffusion barrier layer comprises a discontinuous modified layer and a barrier layer, the discontinuous modified layer is arranged on the surface of the substrate, the material of the discontinuous modified layer is a polymer with hydrophilic groups, the barrier layer is formed on the surface of the substrate and the discontinuous modified layer, and the material of the barrier layer at least comprises a self-repairing polymer; and

a conductive layer disposed on the substrate, wherein the conductive layer is isolated from the substrate by the diffusion barrier structure.

11. The conductive stack of claim 10, wherein the material of the barrier layer further comprises a catalyst material, and the adhesion between the conductive layer and the diffusion barrier structure is between 6mpa and 15 mpa.

12. A method of making a conductive laminate, comprising:

providing a substrate, wherein the substrate is provided with a surface;

performing surface modification treatment on the surface of the substrate to form a discontinuous modified layer on the surface;

forming a barrier layer on the surface and the discontinuous modified layer; and

forming a conductive layer on a surface of the diffusion barrier structure opposite to the substrate;

wherein the material of the discontinuous modified layer comprises a macromolecule with hydrophilic groups,

the material of the barrier layer comprises a self-repairing polymer.

13. The method of claim 12, wherein the self-healing polymer is selected from the group consisting of polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylic acid, polyethylene glycol, and any combination thereof.

14. The method of claim 12, wherein the surface modification treatment comprises immersing the substrate in a modifying solution, wherein the modifying solution comprises the polymer having hydrophilic groups.

15. The method of manufacturing an electrically conductive laminate according to claim 14, wherein the content of the polymer having a hydrophilic group in the modifying solution is 0.1 to 5 volume percent.

16. The method of manufacturing a conductive stack according to claim 14, wherein prior to performing the surface modification treatment, the method further comprises: and pretreating the surface of the substrate, and soaking the substrate in a pretreatment solution, wherein one component of the pretreatment solution is the same as one component of the modification solution.

17. The method of claim 12, wherein the barrier layer is formed by immersing the substrate in a polymer solution, the polymer solution comprising the self-healing polymer.

18. The method of claim 17, wherein the polymer solution further comprises a catalyst material.

19. The method of making a conductive laminate of claim 18, wherein the weight ratio of the self-healing polymer to the catalytic material is 0.175: 1 to 2: 1.