阅读说明：本技术 一种固相键合连接方法 (Solid-phase bonding connection method ) 是由 范金虎 徐鹏 姚育成 吕辉 于 2020-12-24 设计创作，主要内容包括：本发明涉及微电子封装技术领域,具体涉及一种固相键合连接方法,对基体待键合表面进行表面处理后沉积一层厚度为5μm～20μm的钝化膜；将两个沉积有钝化膜的基材相向堆叠后加载机械压力,在压力状态下引燃钝化膜,引发钝化膜的自蔓延反应,利用反应的瞬时高温高热加速键合界面扩散在较低温度下实现良好的固相键合。本发明提供的固相键合连接方法,既能实现可靠的低温键合又能在空气中直接键合,既能键合同种材料也适合于异种材料的连接,使得人们在得到可靠的键合的同时,降低生产成本、提高生产效率、简化键合工艺。(The invention relates to the technical field of microelectronic packaging, in particular to a solid-phase bonding connection method, which comprises the steps of depositing a passivation film with the thickness of 5-20 microns after surface treatment is carried out on the surface of a substrate to be bonded; the two base materials deposited with the passivation films are oppositely stacked and then loaded with mechanical pressure, the passivation films are ignited under the pressure state to initiate the self-propagating reaction of the passivation films, and the instant high temperature and high heat of the reaction are utilized to accelerate the diffusion of the bonding interface to realize good solid-phase bonding at lower temperature. The solid-phase bonding connection method provided by the invention can realize reliable low-temperature bonding and direct bonding in the air, can bond the same material and is also suitable for connection of different materials, so that people can reduce the production cost, improve the production efficiency and simplify the bonding process while obtaining reliable bonding.)

1. A solid-phase bonding connection method is characterized by comprising the following steps:

after the surface of the substrate to be bonded is treated, a layer of passive film with the thickness of 5-20 mu m is deposited; and (3) oppositely stacking the two base materials deposited with the passivation films, loading mechanical pressure, igniting the passivation films in a pressure state, initiating a self-propagating reaction of the passivation films, and obtaining the solid-phase bonding matrix after the reaction is finished.

2. The solid-phase bonding connection method according to claim 1, wherein the two passivation film deposited substrates are the same or different and are respectively selected from pure metals, metal compounds or metal silicides.

3. The solid-phase bonding connection method according to claim 1, wherein the passivation film is formed by alternately depositing Al or Si single-layer films and transition metal single-layer films capable of undergoing a self-propagating reaction with Al or Si, and the sum of the single-layer thicknesses of the two single-layer films is 100-500 nm.

4. The solid-phase bonding connection method according to claim 3, wherein the atomic ratio of the Al or Si single-layer film and the transition metal single-layer film capable of undergoing a self-propagating reaction with Al or Si corresponds to the atomic ratio of the reaction product.

5. The solid-phase bonding connection method according to claim 1, wherein the surface treatment is a plasma treatment, a chemical mechanical polishing, or a formic acid treatment.

6. The solid-phase bonding connection method according to claim 1, wherein the ignition mode is rapid heating to a self-propagating reaction temperature, and heat preservation and pressure maintaining; wherein the heating rate is 4-8 ℃/s.

7. The solid-phase bonding connection method according to claim 6, wherein the mechanical pressure is 10MPa to 20MPa, and the holding time is 15min to 30 min.

8. The solid-phase bonding connection method according to claim 1, wherein the surface treatment is deposition of a brazing film on the surface of the substrate to be bonded, and the brazing film is one selected from a Sn film, an Au-Sn film, a SnAgCu film, a Zn-Cu-Sn film and a boric acid glass film.

9. The solid-phase bonding joining method according to claim 8, wherein the brazing film is deposited to a thickness of 3 to 5 μm.

Technical Field

The invention relates to the technical field of electronic packaging, in particular to a solid-phase bonding connection method.

Background

With the increasing requirements for miniaturization of device size and high-density integration of chips, the traditional two-dimensional packaging integration technology is limited by moore's law and approaches to the physical limit, so that the performance and cost problems caused by interconnection delay and power consumption increase cannot be solved.

The three-dimensional stacking integration and packaging technology realizes the interconnection of chips in the vertical direction, has short delay, low power consumption, high efficiency and high integration density, and becomes the only method for continuing the moore's law. The interconnection bonding connection technology is one of the key technologies for realizing three-dimensional integration and packaging technology. The main bonding connection technologies at present include anodic bonding, adhesive bonding, eutectic bonding, direct wafer bonding, bump bonding and the like, wherein the latter two technologies can realize electrical interconnection, reduce the size of a device and reduce the process cost, and are hot spots of the current bonding connection technology research. But the bonding process uses higher process temperature, so that the use of heat sensitive materials is limited and the service life is influenced by heat damage to other components; the compatibility is poor, and the method is not suitable for direct bonding of dissimilar materials with large difference of expansion coefficients; vacuum or inert atmosphere environment is required, the requirement on bonding equipment is high, and the process is complex.

Disclosure of Invention

In order to solve the technical problems, the invention provides a solid-phase bonding connection method, which can realize reliable low-temperature bonding and direct bonding in air, can bond the same material and is also suitable for the connection of different materials, so that people can reduce the production cost, improve the production efficiency and simplify the bonding process while obtaining reliable bonding.

A solid phase bonding attachment method comprising the steps of:

after the surface of the substrate to be bonded is treated, a layer of passive film with the thickness of 5-20 mu m is deposited; two base materials deposited with passivation films (passivation protection, pollution prevention and surface quality deterioration) are oppositely stacked, then mechanical pressure is applied, the passivation films are ignited under the pressure state, the self-propagating reaction of the passivation films is initiated, and the solid-phase bonding matrix is obtained after the reaction is completed.

Further, the two substrates deposited with the passivation films are the same or different and are respectively selected from pure metals, metal compounds or metal silicides;

further wherein the pure metal is selected from Cu, Al, Au, Ag, Si, Ni, Sn or Ti; the metal compound is selected from TiN and SiO₂Or Al₂O₃(ii) a The metal silicide is selected from WSi₂Or TiSi₂。

Further, the passivation film is formed by alternately depositing Al or Si single-layer films and transition metal single-layer films capable of performing self-propagating reaction with Al or Si, and the sum of the single-layer thicknesses of the two single-layer films is 100-500 nm.

Further, the transition metal monolayer metal is selected from Ti, Ni, Pd, Zr or Pt. The monolayer thickness ratio of the two materials is such that the atomic ratio of the two should correspond to the atomic ratio of the reaction product.

Further, the atomic ratio of the Al or Si single layer film and the transition metal single layer film capable of undergoing a self-propagating reaction with Al or Si corresponds to the atomic ratio of the reaction product.

Further, the surface treatment is plasma treatment, chemical mechanical polishing or formic acid treatment to reduce the surface roughness of the substrate a and/or the substrate B and to improve the surface activity.

Further, the ignition mode is that the mixture is rapidly heated to the self-propagating reaction temperature, and the temperature and pressure are kept; wherein the heating rate is 4-8 ℃/s.

Further, the mechanical pressure intensity is 10 MPa-20 MPa, and the heat preservation time is 15 min-30 min.

Further, the surface treatment is to deposit a brazing film on the surface of the base material to be bonded, wherein the brazing film is selected from one of a Sn film, an Au-Sn film, a SnAgCu film, a Zn-Cu-Sn film and a boric acid glass film.

Further, the brazing film is deposited to a thickness of 3 to 5 μm.

Compared with the prior art, the invention has the following beneficial effects:

1) the solid-phase bonding connection method can obviously activate the diffusion bonding of the bonding interface by utilizing the high temperature and high heat generated by the self-propagating passivation layer film at the bonding moment, thereby obviously reducing the dependence of the bonding on high-temperature diffusion and reducing the production energy consumption and thermal budget, so that the bonding temperature is low, the thermal damage and the thermal stress accumulation to the bonding structure or the device are reduced, the solid-phase bonding connection method can be used for the bonding connection of materials or structures with lower thermal budget, and the reliability of the whole bonding structure or device is improved;

2) the solid-phase bonding connection method is suitable for bonding connection of dissimilar materials frequently appearing in the field of IC manufacturing, and can well overcome thermal mismatch caused by large difference of physical properties of the dissimilar materials;

3) the solid-phase bonding connection method of the invention can complete bonding in the air without high vacuum or special atmosphere, has simple and convenient process operation,

4) the solid-phase bonding connection method is suitable for the bonding interconnection requirement of high density and narrow space under the development trend of high integration.

5) Aiming at the defects of high process temperature, high requirements on bonding surface quality and vacuum degree, long bonding time and the like of the traditional hot-pressing bonding process, the invention provides an efficient low-temperature hot-pressing solid-phase bonding connection technology, can realize reliable solid-phase bonding at lower temperature and in air, can be well suitable for bonding connection of dissimilar materials, and solves the requirement of a high-density narrow-gap bonding structure on the solid-phase bonding connection technology while reducing the bonding temperature and improving the efficiency.

Drawings

FIG. 1 is a process flow diagram of example 1 of the present invention.

Detailed Description

Reference will now be made in detail to various exemplary embodiments of the invention, the detailed description should not be construed as limiting the invention but as a more detailed description of certain aspects, features and embodiments of the invention.

It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Further, for numerical ranges in this disclosure, it is understood that each intervening value, between the upper and lower limit of that range, is also specifically disclosed. Every smaller range between any stated value or intervening value in a stated range and any other stated or intervening value in a stated range is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference herein for the purpose of disclosing and describing the methods and/or materials associated with the documents. In case of conflict with any incorporated document, the present specification will control.

It will be apparent to those skilled in the art that various modifications and variations can be made in the specific embodiments of the present disclosure without departing from the scope or spirit of the disclosure. Other embodiments will be apparent to those skilled in the art from consideration of the specification. The specification and examples are exemplary only.

As used herein, the terms "comprising," "including," "having," "containing," and the like are open-ended terms that mean including, but not limited to.

Example 1

(1) Taking Cu as a substrate A and a substrate B, and respectively carrying out chemical mechanical polishing treatment on the surfaces to be bonded of the substrate A and the substrate B; respectively depositing Al single-layer films with the thickness of 60nm on the surfaces of a substrate A and a substrate B which are subjected to chemical mechanical polishing treatment, then depositing Ni single-layer films with the thickness of 40nm, and sequentially and alternately depositing (the single-layer thickness ratio of the Al single-layer films to the Ni single-layer films is 3: 2, and the atomic ratio is 1: 1) by adopting a magnetron sputtering fine coating process until the total deposition thickness of each substrate is 5 mu m to obtain a substrate A and a substrate B on which passive films are deposited.

(2) The passivation films of the base material A and the base material B deposited with the passivation films are oppositely stacked, then mechanical pressure of 10MPa is loaded, the temperature is rapidly raised to 230-plus-one temperature 240 ℃ at the temperature raising rate of 8 ℃/s under the pressure state, the temperature is preserved for 20min, the passivation films are ignited, the Al single-layer film and the Ni single-layer film are subjected to self-propagating reaction to generate a reaction product AlNi film, and the solid-phase bonding base body is obtained after the reaction is finished.

FIG. 1 is a process flow diagram of an embodiment of the present invention.

Example 2

(1) Taking Cu as a matrix A and TiN as a matrix B, and respectively carrying out chemical mechanical polishing treatment on the surfaces to be bonded of the matrix A and the matrix B; respectively depositing 150 nm-thick Al single-layer films on the surfaces of a base A and a base B which are subjected to chemical mechanical polishing treatment, then depositing 100 nm-thick Ni single-layer films, and sequentially and alternately depositing (the single-layer thickness ratio of the Al single-layer film to the Ni single-layer film is 3: 2, so as to maintain the atomic ratio of the Al single-layer film to the Ni single-layer film to be 1: 1) until the total deposition thickness of each base is 10 mu m, thereby obtaining a base material A and a base material B on which passivation films are deposited.

(2) Stacking the two passivation films of the base material A and the base material B deposited with the passivation films oppositely, loading a mechanical pressure of 15MPa, rapidly heating to 250-260 ℃ at a heating rate of 8 ℃/s in a pressure state, keeping the temperature for 20min, igniting the passivation films, carrying out a self-propagating reaction on the Al single-layer film and the Ni single-layer film to generate a reaction product AlNi film, and obtaining a solid-phase bonding matrix after the reaction is finished.

Example 3

(1) With Cu as the substrate A, WSi₂As a substrate B, respectively carrying out chemical mechanical polishing treatment on the surfaces to be bonded of the substrate A and the substrate B; respectively depositing Al single-layer films with the thickness of 240nm on the surfaces of a base A and a base B which are subjected to chemical mechanical polishing treatment, then depositing Ni single-layer films with the thickness of 180nm, and sequentially and alternately depositing (the single-layer thickness ratio of the Al single-layer films to the Ni single-layer films is 3: 2, so as to maintain the atomic ratio of the Al single-layer films to the Ni single-layer films to be 1: 1) until the total deposition thickness of each base is 15 mu m, thereby obtaining a base material A and a base material B on which passivation films are deposited.

(2) The passivation films of the base material A and the base material B deposited with the passivation films are oppositely stacked, then mechanical pressure of 10MPa is loaded, the temperature is rapidly raised to 260-plus-one temperature 270 ℃ at the temperature raising rate of 8 ℃/s in the pressure state, the temperature is preserved for 20min, the passivation films are ignited, the Al single-layer film and the Ni single-layer film are subjected to self-propagating reaction to generate a reaction product AlNi film, and the solid-phase bonding base body is obtained after the reaction is finished.

Example 4

(1) With SiO₂As matrix A, Al₂O₃As a substrate B, carrying out plasma bombardment treatment on the surfaces to be bonded of the substrate A and the substrate B, and depositing an Au-Sn film of about 3 microns or screen-printing a boric acid glass solder film of 5 microns by magnetron sputtering; respectively and sequentially intersecting the surface of the matrix A and the surface of the matrix B after surface treatmentAn Al single-layer film having a thickness of 300nm was substituted, and then a Pt or Pd single-layer film having a thickness of 270nm (Al single-layer film to Pt or Pd) single-layer film having a single-layer thickness ratio of 10: 9 or 2: 1, so as to maintain the atomic ratio of the two at 1: 1) as the passivation layer, the total thickness of the passivation layer was 20 μm, resulting in a substrate a and a substrate B on which the passivation film was deposited.

(2) Stacking the two passivation films of the base material A and the base material B deposited with the passivation films oppositely, loading a mechanical pressure of 20MPa, rapidly heating to 270-280 ℃ at a heating rate of 5 ℃/s in a pressure state, preserving the temperature for 30min, igniting the passivation films, carrying out a self-propagating reaction on the Al single-layer film and the Ni single-layer film to generate a reaction product AlPt/AlPd film, and obtaining a solid-phase bonding base body after the reaction is finished.

Example 5

(1) Using TiN as matrix A, TiSi₂As a substrate B, depositing a Sn film with the thickness of 3 mu m on the surfaces to be bonded of the substrate A and the substrate B by an electroplating coating process; respectively and alternately depositing Al single-layer films with the thickness of 146nm on the surfaces of the substrate A and the substrate B on which the Sn films are deposited, and then depositing Ni single-layer films with the thickness of 100nm (the single-layer thickness ratio of the Ti single-layer film to the Si single-layer film is 1.46: 1, so as to maintain the atomic ratio of the Ti single-layer film to the Si single-layer film to be 5: 3) until the total deposition thickness of the passivation layer is 15 mu m, thereby obtaining a substrate A and a substrate B on which the passivation films are deposited.

(2) Stacking the passivation films of the base material A and the base material B deposited with the passivation films oppositely, loading a mechanical pressure of 10MPa, rapidly heating to 260-270 ℃ at a heating rate of 8 ℃/s in a pressure state, preserving the temperature for 20-25min, igniting the passivation films, carrying out a self-propagating reaction on the Al single-layer film and the Ni single-layer film to generate a reaction product AlNi film, and obtaining a solid-phase bonding matrix after the reaction is finished.

Effect verification

The solid-phase bonded substrates prepared in examples 1-5 were performance verified as follows: the shear strength of the bonding structure is measured to be higher than 60MPa by adopting multifunctional push-pull test equipment of a composite shear strength test standard JEDEC JESD 22-B117A;

the Al series self-propagating passivation layer product provided by the invention is an Al series intermetallic compound, the Si series self-propagating passivation layer product is a metal silicide, and all the products are conductors and follow IPCA 9701A standard, the conductivity of the bonded structures being 10^-6And 10^-4The magnitude is in accordance with the performance requirement of the local conductive interconnection material in the IPC-4951A standard; after the high-temperature aging is accelerated for 400 hours at 150 ℃, the shear strength attenuation is lower than 10 percent, no obvious tissue defect appears, and the performance is far better than the performance specified by IPC-SM-785 standard.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included therein.