Background technique
Wafer bonding techniques be by two panels surface cleaning, the homogeneity of atomic roughness or dissimilar materials through surface clean andAfter activation processing, any adhesive substance is not used, is directly fitted under certain condition integrally, two panels crystal passes through Van der WaalsPower, molecular force or even atomic force combine.This wafer bonding techniques utilize bonding structure realization, bonding structureIt can be understood as a kind of connecting element.
Wafer bonding techniques have great superiority, have secured, smooth, optical lens by the interface that this technology obtainsBright advantage, this interface have very important significance for the innovation of optical device.
In the prior art, as shown in Figure 1, general bonding structure includes bonded layer 1 and carrier layer 2, and bonded layer 1 only bySingle bond wire is made, and the crystal grain of this bond wire is larger.
Those skilled in the art it is known that, the size of crystal grain has a great impact to the performance of metal material, belowInfluence according to the size of crystal grain to metal material carries out detailed analysis: " boundary " between crystal grain is known as crystal boundary, and " brilliant" crackle " in boundary " and similar material, then " crackle " in the more big then material of crystal grain is also bigger；Secondly, intra-dieAtomic arrangement is more regular, is easy to produce " sliding ", and the atomic arrangement on crystal boundary is more in disorder, exist many " dislocation " and" between splitting " so that not easy glide and deformation between atomic plane, then when crystal grain is tiny, in sliding deformation it is just smaller and can quiltCrystal boundary effectively inhibits；Third, crystal grain, crystal boundary are all more tiny, and external total heavy burden and deformation will be distributed on more crystal grain,A possibility that just reducing the material breakage in this way.
In addition, according to Hall-Patch formula: σy=σ0+ kd-1/2, σ in formulayFor the yield strength of material, σ0For monocrystallineThe yield strength of body, d are crystallite dimension, and k is constant, and k and Taylor factor M2(k ∝ M directly proportional with shear stress τ2τ).Above formulaShow that crystal grain is thinner, interdendritic is away from smaller, and yield strength is higher, while hardness is better.The theoretical origin explains principle as positionWrong strengthening mechanism and crack propagation mechanism.
By analysis it is found that the crystal grain of metal material is smaller, intensity, plasticity, the toughness of metal will be higher.
However, the crystal grain of the bond wire of bonded layer 1 in the prior art is larger, " crackle " between crystal grain is also got overGreatly, this makes the mechanical strength of bonded layer 1 poor, is easy to happen sliding and change between the atomic plane of the intra-die of bond wireShape is easy to appear the problem of bonded layer is loosened, fallen off so as to cause the bonding structure.
Summary of the invention
The application is intended to provide a kind of bonding structure and forming method thereof, to solve the bonding of bonding structure in the prior artThe poor problem of the mechanical strength of layer.
To achieve the goals above, the one aspect of the application provides a kind of bonding structure, comprising: bonded layer, bondingLayer includes bond wire and Grain refiner material, and Grain refiner material is used to refine the crystal grain of bond wire.
Further, bond wire is metallic aluminium.
Further, Grain refiner material is rare metal.
Further, Grain refiner material is Titanium.
Further, bonding structure further include: carrier layer, bonded layer are arranged on a carrier layer.
Further, carrier layer includes: adhesion layer and dielectric layer, and adhesion layer is arranged on dielectric layer, and bonded layer is arrangedOn adhesion layer.
Further, dislodger is provided on adhesion layer, and bonded layer is arranged in dislodger.
Further, bonded layer is arranged by bond wire and Grain refiner material layering, and bonding structure includes moreLayer bonded layer.
Further, bonding structure includes 2 to 10 layers of bonded layer.
Further, adhesion layer is formed by plasma enhanced oxide.
Further, dielectric layer is formed by silicon nitride.
Further, bonded layer is mixed by bond wire and Grain refiner material.
Further aspect of the application provides a kind of method for forming bonding structure, comprising: by bond wire and be used forThe Grain refiner material for refining the crystal grain of bond wire, which combines, forms bonded layer.
Further, the method for forming bonded layer includes: one layer of bond wire of deposition；A layer crystal is deposited on bond wireGrain refiner material.
Further, method further include: repeat alternately to deposit bond wire and Grain refiner material.
Further, the deposition thickness of Grain refiner material is 0.1 to 10nm.
Further, the depositing temperature of Grain refiner material is 5 to 300 degrees Celsius.
Using the technical solution of the application, which includes: bonded layer, and bonded layer includes that bond wire and crystal grain are thinChange material, Grain refiner material is used to refine the crystal grain of bond wire.The application is in order to solve bonded layer in the prior artThe poor problem of mechanical strength makes bonded layer include bond wire and the Grain refiner material for refining bond wire crystal grain,In this way, can so that bond wire crystal grain refinement, and then the mechanical strength of bonded layer can be improved, so that the structure of bonded layerMore firm, the bonded layer for efficiently avoiding occurring bonding structure is easy the problem of loosening, falling off.
Specific embodiment
It should be noted that in the absence of conflict, the features in the embodiments and the embodiments of the present application can phaseMutually combination.The application is described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.
It should be noted that term used herein above is merely to describe specific embodiment, and be not intended to restricted rootAccording to the illustrative embodiments of the application.As used herein, unless the context clearly indicates otherwise, otherwise singularAlso be intended to include plural form, additionally, it should be understood that, when in the present specification using belong to "comprising" and/or " packetInclude " when, indicate existing characteristics, step, operation, device, component and/or their combination.
For ease of description, spatially relative term can be used herein, as " ... on ", " ... top "," ... upper surface ", " above " etc., for describing such as a device shown in the figure or feature and other devices or spyThe spatial relation of sign.It should be understood that spatially relative term is intended to comprising the orientation in addition to device described in figureExcept different direction in use or operation.For example, being described as if the device in attached drawing is squeezed " in other devicesIt will be positioned as " under other devices or construction after part or construction top " or the device of " on other devices or construction "Side " or " under other devices or construction ".Thus, exemplary term " ... top " may include " ... top " and" in ... lower section " two kinds of orientation.The device can also be positioned with other different modes and (is rotated by 90 ° or in other orientation), andAnd respective explanations are made to the opposite description in space used herein above.
As described in background technique, as shown in Figure 1, bonding structure in the prior art includes bonded layer 1 and carriesBody layer 2, which is arranged in carrier layer 2, and bonded layer 1 is only made of single bond wire, and this bond wire existsThe crystal grain generated during crystallization is larger, and the crystal boundary between crystal grain is also larger, i.e., " crackle " in bond wire material is bigger,It is easy to happen sliding and deformation between atomic plane between intra-die, there are keys so as to cause bonding structure in the prior artThe mechanical strength for closing layer is poor, is easy to appear bonded layer loosens, the defect that falls off, present inventor regarding to the issue above intoRow research, proposes a kind of bonding structure and forming method thereof.
The bonding structure that a kind of preferred embodiment of the application provides is as shown in Fig. 2, the bonding structure includes: bonded layer10, bonded layer 10 includes bond wire 11 and Grain refiner material 12, and Grain refiner material 12 is for refining bond wire 11Crystal grain.
The application is poor for the mechanical strength for solving the problems, such as bonded layer in the prior art, and making bonded layer 10 includes keyAlloy belongs to 11 and the Grain refiner material 12 for refining 11 crystal grain of bond wire, in this way, can so that bond wire 11 crystalline substanceGrain refinement, and then the mechanical strength of bonded layer can be improved, so that the structure of bonded layer is more firm, efficiently avoid occurringThe bonded layer of bonding structure is easy the problem of loosening, falling off.
As a kind of preferred embodiment of the application, bond wire 11 is metallic aluminium.It, can also according to practical situationTo select metallic copper as the bond wire 11 in the application.
Grain refiner material 12 can react after contacting with bond wire 11 and generate compound, the compound and liquidThe contact surface of bond wire 11 is effective forming core basal plane when bond wire 11 solidifies, and therefore, Grain refiner material 12 can increaseAdd the nucleation rate of bond wire 11, and then refine the crystal grain of bond wire 11, so that increase bonded layer 10 draws high intensity, mentionsThe mechanical performances such as the high toughness of bonded layer 10.In this application, Grain refiner material 12 is rare metal.According to practical feelingsCondition can also select titanium boron fining agent and al-ti-b refiner as Grain refiner material 12.
Preferably, which is Titanium.According to the actual situation, staff can choose tantalum, niobium,The rare metals such as zirconium, molybdenum, tungsten, vanadium, titanium are as Grain refiner material 12.When depositing bond wire 11, staff can lead toIt crosses and above-mentioned Grain refiner material 12 is added, to realize the refinement of crystal grain.The refining effect of above-mentioned Grain refiner material 12 is mainBe: bond wire 11 and above-mentioned Grain refiner material 12 react and generate dystectic compound, when the bonding of liquidWhen metal 11 solidifies, those high melting compounds can play the role of increasing the nuclei of crystallization, to guarantee that the bond wire 11 obtainsThinner crystal grain；In addition, these compounds all play the role of mechanical obstruction simultaneously again, the fine grain formed can be made to be not easyIt grows up, has further achieved the effect that refine crystal grain.
It is metallic aluminium below with reference to bond wire 11, Grain refiner material 12 is the embodiment of Titanium, analysis bonding goldBelong to the process of 11 crystal grain refinement: peritectic reaction can occur after Titanium and Al Contact and generate Titanium Trialuminum, Titanium TrialuminumEffective forming core basal plane when contact surface with the metallic aluminium of liquid is solidified aluminum, in this way, the nucleation rate of metallic aluminium is substantially increased, fromAnd the crystalline structure of metallic aluminium is refined.
In this application, bonding structure further include: carrier layer 20, bonded layer 10 are arranged in carrier layer 20.Preferably, it carriesBody layer 20 includes: adhesion layer 21 and dielectric layer 22, and adhesion layer 21 is arranged on dielectric layer 22, and bonded layer 10 is arranged in adhesion layerOn 21.
Preferably, dislodger 23 is provided on adhesion layer 21, and bonded layer 10 is arranged in dislodger 23.The application passes throughThe position for bonded layer to be arranged is limited, can purposefully arrange and shapes the bonding structure, preciousness can be saved in this wayNoble metal.In addition, the application can increase bond wire 11 and adhesion layer by being arranged bonded layer 10 in dislodger 23Contact area between 21, and then the bonding force between bond wire 11 and adhesion layer 21 can be increased.
In an embodiment in this application, bonded layer 10 is set by bond wire 11 and the layering of Grain refiner material 12It sets, and bonding structure includes multilayer bonded layer 10.Firstly, staff can first deposit one layer of bond wire 11, thenOne layer of Grain refiner material 12 is deposited on this layer of bond wire 11, can form first layer bonded layer 10 in this way；Then, work peopleMember can refer to above-mentioned step and deposit the second layer on first layer bonded layer 10 layer by layer to n-th layer bonded layer 10.Preferably, keyClosing structure includes 2 to 10 layers of bonded layer 10.This layering setting method can be such that bond wire 11 and Grain refiner material 12 dividesCloth it is relatively uniform.This deposition method make the thickness degree of bond wire 11 and Grain refiner material 12 in bonded layer 10 compared withIt is thin, so that the structure of bonded layer 10 is more uniform, be conducive to generate lesser crystal grain.
In this application, adhesion layer 21 is formed by plasma enhanced oxide.Preferably, adhesion layer 21 is enhanced by plasmaSilica is formed.After being provided with adhesion layer 21 in the application, the contact force between carrier layer 20 and bonded layer 10 can be enhanced, haveIt avoids to effect and occurs between bonded layer 10 and carrier layer 20 that there is a situation where be detached from.
In this application, dielectric layer 22 is formed by silicon nitride.
In another embodiment in this application, bonded layer 10 is mixed by bond wire 11 and Grain refiner material 12It forms.The forming method of this bonded layer 10 are as follows: during depositing bond wire 11, while it being passed through Grain refiner material,So that bond wire 11 and the reaction of Grain refiner material 12 form the bonded layer 10.According to the actual situation, staff can beSame position deposits bond wire 11 and Grain refiner material 12 simultaneously, and the two is made to be mixed to form the bonded layer 10.It is thisDeposition method can make bond wire 11 come into full contact with Grain refiner material 12, and then improve the forming core of bond wire 11Rate.
In addition, present invention also provides a kind of methods for forming bonding structure, comprising: by bond wire and be used to refine keyThe Grain refiner material for the crystal grain that alloy belongs to combines and forms bonded layer.The bonded layer formed in this way has preferable machineTool intensity.
As one of the application preferred embodiment, the method for forming bonded layer includes: one layer of bonding gold of depositionBelong to；One layer of Grain refiner material is deposited on bond wire.The deposition of above-mentioned bond wire and Grain refiner material can useThe method of chemical vapor deposition or physical vapour deposition (PVD) etc. is implemented.
Road as is known in the art, chemical vapour deposition technique is traditional technology for preparing film,Principle is using gaseous pioneer's reactant, by atom, intermolecular chemical reaction, so that certain ingredients in gaseous precursorIt decomposes, and forms film on matrix.Chemical vapor deposition includes that aumospheric pressure cvd, plasma auxiliary chemical are heavyProduct, Laser-assisted chemical deposition, metallo-organic compound deposition etc..Such as the bond wire can be deposited using the method for sputteringAnd Grain refiner material, it is possible thereby to generate relatively thin and uniform thickness degree.Sputtering is a kind of physical gas phase deposition technology, it isDescribe that the atom in solid target is left the physical process that solid enters gas by high energy ion shock, and in sputtering processIon is usually from plasma.The advantages of sputtering is the film that can prepare materials with high melting point at a lower temperature, is being preparedKeep former composition constant during alloy and compound film, so having obtained in semiconductor devices and IC manufacturingIt is widely applied.
According to practical situation, which can also be deposited using the deposition method of electrochemistry, pass through electrochemistryThe bond wire of deposition method deposition has more smooth, uniform thickness degree.Such as this can be deposited by electric plating methodBond wire and Grain refiner material, electroplating technology are also known as electro-deposition, are the main sides for obtaining the coat of metal on the surface of the materialOne of method, principle are to constitute circuit under the action of DC electric field by anode and cathode in electrolyte solution (plating solution), makeThe process on metal ion deposition to cathode plating piece surface in solution.
In this application, this method further include: repeat alternately to deposit bond wire and Grain refiner material.In this way, justThe bonded layer that bond wire and Grain refiner material are layered on top of each other can be formed.
Preferably, the deposition thickness of Grain refiner material is 0.1 to 10nm.The bonded layer can be with preset thickness (exampleThickness such as between 1nm and 10000nm, the thickness especially between 10nm and 1000nm) it deposits.By this defaultThickness degree can limit bonded layer inside particle size.In the case where lesser particle, a kind of material can be oppositeThere is improved material property in average state, such as improve tensile strength and/or bigger hardness.Lesser particle is being bondedA large amount of nucleus are provided in the process, are increased for the crystal beyond interface.
Preferably, the depositing temperature of Grain refiner material is 5 to 300 degrees Celsius.
As another preferred embodiment in the application, the method for forming bonded layer includes: in deposition bonding goldDuring category, while it being passed through Grain refiner material, so that bond wire and Grain refiner material react to form bonded layer.
It can be seen from the above description that the application the above embodiments realize following technical effect:
The crystal grain of bond wire is refined, and then the machinery for improving bonded layer is slight, so as to avoid bonding structureThe problem of bonded layer is easy to appear loosening, falls off.
The foregoing is merely preferred embodiment of the present application, are not intended to limit this application, for the skill of this fieldFor art personnel, various changes and changes are possible in this application.Within the spirit and principles of this application, made any to repairChange, equivalent replacement, improvement etc., should be included within the scope of protection of this application.