Heterogeneous electroplating method, electroplating device and wafer processing equipment

Abstract

The invention provides a heterogeneous electroplating method, an electroplating device and wafer processing equipment, relates to the field of semiconductor processing, and solves the technical problem that a heterogeneous electroplating film is easy to fall off. The heterogeneous electroplating method comprises the following steps: providing a wafer of which at least one part of the surface is provided with an exposed target metal-containing layer; the wafer is placed in the first electroplating liquid, the adhesion layer with a certain thickness is formed on the target metal layer in an electroplating mode through the first electroplating technology, and due to the fact that the adhesion layer has good adhesiveness, the adhesion layer can be tightly attached to the target metal layer and is not prone to falling off from the target metal layer; then the wafer is placed in a second electroplating solution, a second electroplating process is used for electroplating on the adhesion layer to form the main body electroplating layer, and the adhesion layer has good adhesiveness and can be tightly attached to the main body electroplating layer, so that the main body electroplating layer and the adhesion layer form an integral layer during electroplating and after electroplating; and the main body electroplated layer is not easy to fall off from the adhesive layer.

Description

Technical Field

[0001] The present application relates to the field of semiconductor processing, and in particular to a heterogeneous electroplating method, an electroplating device, and a wafer processing equipment. Background Art

[0002] Gold has good electrical and thermal conductivity. Since gold has better corrosion resistance than copper and silver, despite its high price, it still has unique applications in semiconductors. For example, gold bumps are used in display panel driver chips, and gold is used as a protective layer in advanced packaging fields.

[0003] In the field of semiconductor processing, electroplating is generally used to plate gold on semiconductors. Based on the usage scenario, a heterogeneous gold plating process is usually used, that is, the seed layer of the semiconductor is usually a metal other than gold, because mechanical properties and barrier layers need to be considered. Common seed layers include nickel (Ni) layer and cobalt (Co) layer. Due to the differences in chemical properties and electrochemical characteristics, it is difficult for gold to form heterogeneous nuclei on nickel and other materials. The gold plating directly electroplated on the nickel layer often has insufficient adhesion and is easily peeled off. Summary of the invention

[0004] In order to solve the above technical problems, the present application is proposed. The embodiments of the present application provide a heterogeneous electroplating method, an electroplating device and a wafer processing device.

[0005] In a first aspect, an embodiment of the present application provides a heterogeneous electroplating method, comprising: providing a wafer having an exposed target metal layer on at least a portion of its surface; placing the wafer in a first electroplating solution, and using a first electroplating process to electroplate an adhesion layer having a certain thickness on the target metal layer, wherein the target metal layer and the adhesion layer are heterogeneous metal layers, and the adhesion layer can be tightly bonded to the target metal layer; placing the wafer in a second electroplating solution, and using a second electroplating process to electroplate a main electroplating layer on the adhesion layer; wherein the main electroplating layer and the adhesion layer are the same metal layer, and the adhesion layer enables the main electroplating layer and the adhesion layer to form an integral layer during and after electroplating.

[0006] In some embodiments, a first electroplating process is used to electroplate an adhesion layer having a certain thickness on a target metal layer, comprising: applying a preset first process current to the surface of the target metal layer of a wafer under a first process parameter of a preset first electroplating process; electroplating for a first preset time under the first process parameter and the first process current to form an adhesion layer having a certain thickness on the surface of the target metal layer of the wafer; wherein the first process parameter comprises at least one of a flow rate of a first electroplating solution, a temperature of the first electroplating solution, a rotation speed of the wafer, and a distance between a cathode and an anode.

[0007] In some embodiments, the first process current is a pulse current, and a period of a pulse wave in the pulse current ranges from 100 milliseconds to 200 milliseconds.

[0008] In some embodiments, the pulse current is a rectangular pulse wave, and the ratio of the time when the current density is greater than 0 to the time when the current density is equal to 0 in one cycle of the rectangular pulse wave is greater than or equal to 1:10 and less than or equal to 1:2. Preferably, the ratio is 1:7 or 1:8 or 1:9.

[0009] In some embodiments, the flow rate of the first electroplating solution is 8-50 liters / minute; and / or the duty cycle of the load in the pulse current ranges from 60% to 90%; and / or the current density of the peak value of the pulse current ranges from 4 amperes / square decimeter to 12 amperes / square decimeter; and / or the first preset time is 3 seconds to 6 seconds.

[0010] In some embodiments, a second electroplating process is used to electroplate a main electroplating layer on the adhesion layer, comprising: electroplating the adhesion layer for a second preset time using a continuous direct current under second process parameters of the preset second electroplating process to form the main electroplating layer on the adhesion layer; wherein the second process parameters include at least one of the flow rate of the second electroplating solution, the temperature of the second electroplating solution, the rotation speed of the wafer, and the distance between the cathode and the anode.

[0011] In some embodiments, the flow rate of the second plating solution is 8-50 L / min; and / or the current density of the direct current is in a range of 0.6 A / dm2 to 1.2 A / dm2.

[0012] In some embodiments, the first plating solution is the same as or different from the second plating solution.

[0013] In some embodiments, the thickness of the adhesion layer is much smaller than the thickness of the main electroplating layer, and the thickness of the adhesion layer ranges from 2 nanometers to 10 nanometers.

[0014] In a second aspect, an embodiment of the present application provides an electroplating device, which is configured to electroplate a wafer having an exposed target metal layer on at least a portion of its surface, and includes: an electroplating chamber, the electroplating chamber having a plating tank, the plating tank containing a plating solution; a fixture, configured to fix and adjust the posture of the wafer, and drive the wafer to be immersed in the plating solution or to be separated from the plating solution; an anode, at least partially immersed in the plating solution; a DC power supply, the positive electrode of the DC power supply is electrically connected to the anode, the negative electrode of the DC power supply is electrically connected to the wafer, and the DC power supply is used to output a DC current; and a controller, The DC power supply communication connection is configured to control the DC power supply to output a pulse current of a first preset time so that an adhesion layer with a certain thickness is formed on the surface of the target metal layer, wherein the target metal layer and the adhesion layer are heterogeneous metal layers, and the adhesion layer can be tightly attached to the target metal layer, and to control the DC power supply to output a continuous DC current of a second preset time so that a main electroplating layer is formed on the surface of the adhesion layer, wherein the main electroplating layer and the adhesion layer are the same metal layer, and the adhesion layer enables the main electroplating layer and the adhesion layer to form an integral layer during and after electroplating.

[0015] In the third aspect, an embodiment of the present application provides a wafer processing equipment, including: a deposition device, configured to deposit a target metal layer on at least a portion of the wafer surface to obtain a deposited wafer; a first transportation device, configured to transport the deposited wafer; the electroplating device in the above-mentioned second aspect, configured to receive the deposited wafer transported by the first transportation device, and electroplate the deposited wafer to obtain a plated wafer; a cleaning device, configured to receive the electroplated wafer from the electroplating device, and clean the electroplated wafer to obtain a cleaned wafer; a second transportation device, configured to receive the cleaned wafer from the cleaning device, and transport the cleaned wafer to the next process link.

[0016] The heterogeneous electroplating method, electroplating device and wafer processing equipment proposed in the embodiments of the present application are as follows: before preparing the main electroplating layer, an adhesion layer is first prepared on the target metal layer. Since the adhesion layer has good adhesion, the adhesion layer can be tightly attached to the target metal layer and is not easy to fall off from the target metal layer. Then, the main electroplating layer is prepared on the adhesion layer. Since the adhesion layer has good adhesion and the adhesion layer and the main electroplating layer are the same metal layer, the adhesion layer can be tightly attached to the main electroplating layer, so that the main electroplating layer is not easy to fall off from the adhesion layer, and the two form a complete electroplating layer, thereby improving the process quality and yield rate of wafer electroplating. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] By describing the embodiments of the present application in more detail in conjunction with the accompanying drawings, the above and other purposes, features and advantages of the present application will become more apparent. The accompanying drawings are used to provide a further understanding of the embodiments of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the present application and do not constitute a limitation of the present application. In the accompanying drawings, the same reference numerals generally represent the same components or steps.

[0018] Figure 1 Shown is a schematic flow chart of a heterogeneous electroplating method provided by an exemplary embodiment of the present application.

[0019] Figure 2 Shown is a schematic diagram of current waveforms of a first electroplating process and a second electroplating process provided by an exemplary embodiment of the present application.

[0020] Figure 3 Shown is a schematic structural diagram of a wafer after electroplating provided by an exemplary embodiment of the present application.

[0021] Figure 4 Shown is a schematic diagram of a process for preparing an adhesion layer provided by an exemplary embodiment of the present application.

[0022] Figure 5 Shown is a schematic diagram of a process for preparing a main electroplating layer provided by an exemplary embodiment of the present application.

[0023] Figure 6 Shown is a schematic structural diagram of an electroplating device provided by an exemplary embodiment of the present application.

[0024] Figure 7 Shown is a schematic structural diagram of a wafer processing device provided by an exemplary embodiment of the present application.

[0025] Reference numerals:

[0026] 200, wafer after electroplating; 201, substrate; 202, target metal layer; 203, adhesion layer; 204, main electroplating layer; 500, electroplating device; 501, electroplating chamber; 502, fixture; 503, anode; 504, DC power supply; 505, controller; 600, wafer processing equipment; 601, deposition device; 602, first transport device; 603, cleaning device; 604, second transport device. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0028] Exemplary Methods

[0029] Figure 1 FIG. 1 is a schematic flow chart of a heterogeneous electroplating method provided by an exemplary embodiment of the present application. Figure 2 FIG. 1 is a schematic diagram showing waveforms of currents of a first electroplating process and a second electroplating process provided by an exemplary embodiment of the present application. Figure 2 Where J1 represents the current density of the first process current, J2 represents the current density of the second process current, t1 represents the electroplating completion time of the first electroplating process, and t2 represents the electroplating completion time of the second electroplating process. Figure 3 Shown is a schematic structural diagram of a wafer after electroplating provided by an exemplary embodiment of the present application.

[0030] like Figure 1 and Figure 2 As shown, an embodiment of the present application provides a heterogeneous electroplating method, and the execution body of the heterogeneous electroplating method is exemplarily an electroplating device 500, and the heterogeneous electroplating method includes the following steps 101 to 103.

[0031] Step 101 : providing a wafer having a target metal layer exposed on at least a portion of its surface.

[0032] Among them, at least a portion of the surface of the wafer having an exposed target metal layer includes a target metal layer 202 and a substrate 201. The target metal layer 202 can be a seed layer, or a thin film metal layer deposited in a previous process. The target metal layer 202 is a conductive layer used for nucleation and coating in subsequent processes. The material of the seed layer is usually metal, such as the material of the seed layer may include nickel (Ni) and / or cobalt (Co). Exemplarily, the thickness of the seed layer can be a thin 100 nanometer level, and the thickness of the thin film metal layer can be a thick micrometer level.

[0033] Specifically, when the target metal layer 202 is deposited on the surface of the substrate 201, the target metal layer 202 can be deposited on the surface of the substrate 201 by the deposition device 601, that is, the target metal layer 202 can be deposited on the surface of the substrate 201 by a physical vapor deposition (PVD) process or a chemical vapor deposition (CVD) process. The target metal layer 202 can also be a Ni or Co barrier layer obtained by electroplating on a PVD or CVD seed layer.

[0034] Step 102, placing the wafer in a first electroplating solution, and using a first electroplating process to electroplate an adhesion layer with a certain thickness on the target metal layer, wherein the target metal layer and the adhesion layer are heterogeneous metal layers, and the adhesion layer can be tightly bonded to the target metal layer.

[0035] The first electroplating solution exemplarily includes gold (Au) ions. The target metal layer 202 and the adhesion layer 203 are heterogeneous metal layers, which means that the material of the target metal layer 202 and the material of the adhesion layer 203 are both metals, and the material of the target metal layer 202 is different from the material of the adhesion layer 203, such as the material of the adhesion layer 203 is gold, and the material of the target metal layer 202 is nickel.

[0036] Specifically, when placing the wafer in the first electroplating solution, the wafer having at least a portion of the surface with the target metal layer 202 exposed can be first transported from the deposition device 601 to the clamp 502 of the electroplating device 500 by the first transport device 602 (such as a robot). The clamp 502 can fix and adjust the posture of the wafer, and then the wafer is immersed in the first electroplating solution in the electroplating device 500 by controlling the clamp 502.

[0037] Step 103, placing the wafer in a second electroplating solution, and using a second electroplating process to electroplate on the adhesion layer to form a main electroplating layer; wherein the main electroplating layer and the adhesion layer are the same metal layer, and the adhesion layer allows the main electroplating layer and the adhesion layer to form an integral layer during and after electroplating.

[0038] The wafer in step 103 refers to the wafer with the adhesion layer 203 after being processed in step 102. The second electroplating solution illustratively includes gold (Aurum, Au) ions. The main electroplating layer 204 and the adhesion layer 203 are the same metal layer, which means that the material of the main electroplating layer 204 and the material of the adhesion layer 203 are both metal, and the material of the main electroplating layer 204 and the material of the adhesion layer 203 are the same, such as the material of the main electroplating layer 204 and the material of the adhesion layer 203 are both gold. The first electroplating process and the second electroplating process have different process parameters, current parameters and electroplating time. Specifically, the process parameters may include at least one of the following: flow rate of the electroplating solution, temperature of the electroplating solution, distance between the cathode and the anode, fixture rotation speed, etc. The current parameters may include at least one of the following: current type (such as the current type may include: continuous direct current, pulse current, etc.), current density, etc. The current parameters of the pulse current may also include: the period of a pulse wave in the pulse current, the duty cycle of the load in the pulse current, the current density of the peak value of the pulse current, etc. Since the first electroplating process and the second electroplating process have different process parameters, current parameters and electroplating time, the main electroplating layer and the adhesion layer may have different properties although they are the same metal layer, such as making the adhesion layer have better adhesion and making the main electroplating layer have better corrosion resistance.

[0039] In the above embodiment, before preparing the main electroplating layer 204, an adhesion layer 203 is first prepared on the target metal layer 202. Since the adhesion layer 203 has good adhesion, the adhesion layer 203 can be tightly attached to the target metal layer 202 and is not easy to fall off from the target metal layer 202. Then, the main electroplating layer 204 is prepared on the adhesion layer 203. Since the adhesion layer 203 has good adhesion and the adhesion layer 203 and the main electroplating layer 204 are the same metal layer, the adhesion layer 203 can be tightly attached to the main electroplating layer 204, so that the main electroplating layer 204 is not easy to fall off from the adhesion layer 203, and the two form a complete electroplating layer, thereby improving the process quality and yield rate of wafer electroplating.

[0040] In some embodiments, after the second electroplating process is used to electroplate the main electroplated layer 204 on the adhesion layer 203, the electroplated wafer 200 may be cleaned. Specifically, the fixture 502 may be controlled to rise and separate from the second electroplating solution, and then the cleaning device 603 may be used to clean the electroplated wafer 200.

[0041] In some embodiments, the first plating solution is the same as or different from the second plating solution.

[0042] Exemplarily, the first electroplating solution and the second electroplating solution are the same solution containing gold ions.

[0043] In this embodiment, the following steps 1 to 4 may be used to plate gold on the wafer.

[0044] Step 1: Place the wafer in the fixture of the base plating chamber and immerse the wafer in the base plating solution (i.e. a special gold solution) for base electroplating to obtain a very thin layer (about 10nm to 100nm, depending on the specific process) with good adhesion.

[0045] Step 2: Take the wafer out of the base plating solution and clean it.

[0046] Step 3: Transfer the wafer by a robot, place the wafer in the fixture of the main plating cavity, and immerse the wafer in the main plating solution (i.e., another gold solution different from the base plating solution) for main electroplating to obtain a main layer of about 1um to 10um.

[0047] Step 4: Remove the wafer from the main plating solution, clean it, and then transfer the wafer to the next process link.

[0048] Although the above electroplating method can achieve the same effect, including good adhesion of the base layer, and the main layer is not easy to peel off from the base layer, etc., if this electroplating method is adopted, it has the following defects.

[0049] First, two types of electroplating solutions need to be purchased (i.e., base plating solution and main plating solution). Usually, the cost of base plating solution is much higher than that of main plating solution, which greatly increases the cost of electroplating. Since the electroplating solution needs to be frequently replenished in actual production, cost is an important consideration in the electroplating process.

[0050] Second, the need to store and manage two electroplating solutions increases the difficulty of management and control and the storage space.

[0051] Third, since the wafer needs to be transferred between two electroplating solutions and needs to be cleaned between the base plating and the main body plating, the production time is long and the production efficiency is low. In addition, due to the large number of process steps, the probability of production accidents is high, such as easy occurrence of breakage and wafer humidity control deviation, which affects the yield rate of wafer processing.

[0052] Therefore, based on the above factors, in the embodiment of the present application, it is preferred to make the first electroplating liquid the same as the second electroplating liquid. Then, during the process, only one electroplating liquid needs to be used, and the electroplating liquid is the above-mentioned main plating liquid, which reduces the cost of the electroplating liquid, reduces the difficulty of controlling the electroplating liquid and the storage space; and during the first electroplating process and the second electroplating process, the wafer can always be placed in the electroplating liquid, and there is no need to transfer the wafer or clean the wafer between the first electroplating process and the second electroplating process. When switching between the first electroplating process and the second electroplating process, it is only necessary to switch the process parameters, current parameters and electroplating time through the control system of the electroplating device 500, so as to quickly switch from the first electroplating process to the second electroplating process, thereby simplifying the process flow, greatly improving production efficiency, and reducing the probability of production accidents.

[0053] In addition, in the embodiment of the present application, when the first electroplating solution and the second electroplating solution are the same, a commonly used characterization method for semiconductor integration is adopted, including cross-sectional scanning electron microscope (SEM) inspection and tape stripping test. The verification results show that the adhesion layer and the main electroplating layer prepared by the method described in the embodiment of the present application, and the primer layer and the main layer prepared by the method in the related art, are basically consistent in the bonding force between the films, the degree of almost no gaps between the film interfaces, and the uniformity. Moreover, since the method in the embodiment of the present application uses a single electroplating solution, the interface changes between the adhesion layer and the main electroplating layer are more subtle, so that the adhesion layer and the main electroplating layer can form an integral layer.

[0054] Figure 4 Shown is a schematic diagram of a process for preparing an adhesion layer provided by an exemplary embodiment of the present application.

[0055] In some embodiments, Figure 2 and Figure 4 As shown, when the first electroplating process is used to electroplatingly form an adhesion layer having a certain thickness on the target metal layer, the following steps 301 to 302 may be performed.

[0056] Step 301 : applying a preset first process current to the surface of a target metal layer of a wafer under a preset first process parameter of a first electroplating process.

[0057] Step 302 , electroplating for a first preset time under first process parameters and a first process current to form an adhesion layer of a certain thickness on the surface of the target metal layer of the wafer.

[0058] Among them, the first process parameter includes at least one of the flow rate of the first electroplating solution, the temperature of the first electroplating solution, the rotation speed of the wafer, and the distance between the cathode and the anode. During the electroplating process, the flow rate, temperature, etc. will affect the electroplating effect. During the electroplating process, the fixture will synchronously drive the wafer to rotate to ensure a good electroplating effect, especially the uniformity of electroplating. The distance between the anode and cathode is also one of the parameters affecting the electroplating effect. It should be noted that the process parameters listed above are only part of the parameters, and may also include the concentration of inhibitors, the concentration of metal ions in the electroplating solution, etc. This embodiment does not list them one by one here, but they are all within the protection scope of this embodiment.

[0059] By controlling the first process parameters, the current parameters of the first process current, and the first preset time, an adhesion layer 203 of a certain thickness can be formed on the surface of the target metal layer 202 of the wafer. In actual testing, the first process parameters, the current parameters of the first process current, and the first preset time can be changed for many times, and the shape of the prepared adhesion layer 203 can be observed, so that the adhesion layer 203 has a strong adhesion, a smooth surface, a uniform film layer, and a thin thickness, and the best first process parameters, current parameters of the first process current, and the first preset time can be determined. When determining the best first process parameters, current parameters of the first process current, and the first preset time, the relevant parameters of the first electroplating solution, the pattern size and the aperture ratio of the wafer can also be used for optimization.

[0060] The first process parameters of the first electroplating process, the current parameters of the first process current, and the first preset time are described in detail below.

[0061] In some embodiments, the first process current is a pulse current, and a period of a pulse wave in the pulse current ranges from 100 milliseconds to 200 milliseconds.

[0062] Exemplarily, the period of one pulse wave is 150 milliseconds.

[0063] In some embodiments, the pulse current is a rectangular pulse wave, and the ratio of the time when the current density is greater than 0 to the time when the current density is equal to 0 in one cycle of the rectangular pulse wave is greater than or equal to 1:10 and less than or equal to 1:2. Preferably, the ratio is 1:7 or 1:8 or 1:9.

[0064] For example, if the period of a pulse wave is 100 milliseconds, the time during which the current density is greater than 0 in one period is 20 milliseconds, and the time during which the current density is equal to 0 in one period is 80 milliseconds.

[0065] In some embodiments, the flow rate of the first plating solution is 8-50 liters / minute.

[0066] Exemplarily, the flow rate of the first plating solution is 30 liters / minute.

[0067] In some embodiments, the duty cycle of the load in the pulse current ranges from 60% to 90%.

[0068] For example, the duty cycle of the load in the pulse current ranges from 75%

[0069] In some embodiments, the peak current density of the pulse current ranges from 4 A / dm2 to 12 A / dm2.

[0070] Exemplarily, the current density of the peak value of the pulse current is 8 amperes per square decimeter.

[0071] In some embodiments, the first preset time is 3 seconds to 6 seconds.

[0072] Exemplarily, the first preset time is 5 seconds.

[0073] By electroplating the adhesion layer 203 using at least one of the above parameters, the adhesion layer 203 can have good adhesion and uniformity, and the surface of the adhesion layer 203 can be smoother and the thickness can be thinner.

[0074] Figure 5 It is a schematic diagram of the process of preparing the main electroplating layer 204 provided by an exemplary embodiment of the present application.

[0075] In some embodiments, Figure 2 and Figure 5 As shown, when the main electroplating layer 204 is formed on the adhesion layer 203 by electroplating using the second electroplating process, the following steps 401 may be performed.

[0076] Step 401 : Under the second process parameters of the preset second electroplating process, use a continuous direct current to electroplate the adhesion layer for a second preset time to form a main electroplating layer on the adhesion layer.

[0077] The second process parameter includes at least one of a flow rate of the second electroplating solution, a temperature of the second electroplating solution, a rotation speed of the wafer, and a distance between the cathode and the anode.

[0078] By controlling the second process parameter, the current parameter of the second process current (i.e. the continuous DC current) and the second preset time, the main electroplating layer 204 can be formed on the surface of the adhesion layer 203. The second preset time can be set according to the required thickness of the main electroplating layer 204.

[0079] The second process parameters of the second electroplating process, the current parameters of the second process current, and the second preset time are described in detail below.

[0080] In some embodiments, the flow rate of the second plating solution is 8-50 liters / minute.

[0081] Exemplarily, the flow rate of the second plating solution is 40 liters / minute.

[0082] In some embodiments, the current density of the DC current ranges from 0.6 A / dm2 to 1.2 A / dm2.

[0083] Exemplarily, the current density of the direct current is 1 ampere / square decimeter.

[0084] By electroplating the main electroplating layer 204 using at least one of the above parameters, the main electroplating layer 204 can have good corrosion resistance.

[0085] In some embodiments, the thickness of the adhesion layer 203 is much smaller than the thickness of the main electroplating layer 204. For example, the thickness of the adhesion layer 203 is smaller than the thickness of the main electroplating layer 204. In some embodiments, the thickness of the adhesive layer 203 ranges from 2 nanometers to 10 nanometers. In some embodiments, the thickness of the adhesive layer 203 may exceed 10 nanometers. In some embodiments, the thickness of the adhesive layer 203 may exceed 15 nanometers.

[0086] In some embodiments, the thickness of the main electroplating layer 204 may be 1 to 10 microns, in some embodiments, the thickness of the main electroplating layer 204 may exceed 10 microns, and in some embodiments, the thickness of the main electroplating layer 204 may reach 20 microns. This mainly depends on the characteristics of the wafer surface electroplating.

[0087] Exemplarily, the thickness of the adhesion layer 203 is 5 nanometers, and the thickness of the main electroplating layer 204 is 5 micrometers.

[0088] By electroplating a thinner adhesion layer 203 , the electroplating time of the adhesion layer 203 (ie, the electroplating time of the first electroplating process) can be shortened, thereby improving production efficiency.

[0089] Exemplary Devices

[0090] Combination of the above Figures 1 to 5 , describes the method embodiment of the present application in detail, and the following is combined with Figure 6 , describes the device embodiment of the present application in detail. It should be understood that the description of the method embodiment corresponds to the description of the device embodiment, so the parts not described in detail can refer to the previous method embodiment.

[0091] Figure 6 FIG. 5 is a schematic diagram of the structure of an electroplating device 500 provided by an exemplary embodiment of the present application. Figure 6As shown, the electroplating device 500 provided in the embodiment of the present application is configured to electroplate a wafer having an exposed target metal layer 202 on at least a portion of the surface, and includes: an electroplating chamber 501, a fixture 502, an anode 503, a DC power supply 504 and a controller 505. The electroplating chamber 501 has an electroplating tank, and the electroplating tank contains an electroplating solution. The fixture 502 is configured to fix and adjust the posture of the wafer, and drive the wafer to be immersed in the electroplating solution or to be separated from the electroplating solution. During the electroplating process, the fixture 502 will drive the wafer to rotate synchronously so that the wafer can better complete the electroplating process. At least part of the anode 503 is immersed in the electroplating solution. The positive pole of the DC power supply 504 is electrically connected to the anode 503, and the negative pole of the DC power supply 504 is electrically connected to the wafer, and the DC power supply 504 is used to output a DC current. The controller 505 is communicatively connected to the DC power supply 504, and is configured to control the DC power supply 504 to output a pulse current of a first preset time (i.e., the above-mentioned first process current) so that an adhesion layer 203 with a certain thickness is formed on the surface of the target metal layer 202, wherein the target metal layer 202 and the adhesion layer 203 are heterogeneous metal layers, and the adhesion layer 203 can be tightly attached to the target metal layer 202, and to control the DC power supply 504 to output a continuous DC current of a second preset time (i.e., the above-mentioned second process current) so that a main electroplating layer 204 is formed on the surface of the adhesion layer 203, wherein the main electroplating layer 204 and the adhesion layer 203 are the same metal layers, and the adhesion layer 203 enables the main electroplating layer 204 and the adhesion layer 203 to form an integral layer during and after electroplating.

[0092] Through this structure, the adhesion layer 203 and the main electroplating layer 204 can be electroplated on the target metal layer 202 in sequence, so that the target metal layer 202 and the adhesion layer 203 are closely attached, and the adhesion layer 203 and the main electroplating layer 204 are closely attached, thereby improving the process quality and yield rate of wafer electroplating. In addition, this structure only requires one electroplating chamber 201 and one electroplating solution, which reduces the electroplating cost, reduces the difficulty of control and storage space of the electroplating solution; and between the electroplated adhesion layer 203 and the main electroplating layer 204, the wafer can always be placed in the electroplating solution, and there is no need to transfer the wafer or clean the wafer. Only by switching the process parameters through the controller 505, the process of electroplating the adhesion layer 203 can be quickly switched to the process of electroplating the main electroplating layer 204, which simplifies the process flow, greatly improves production efficiency, and reduces the probability of production accidents.

[0093] The embodiment of the present application also provides a wafer processing device 600 . Figure 7 FIG. 1 is a schematic diagram of the structure of a wafer processing device provided by an exemplary embodiment of the present application. Figure 7As shown, the wafer processing equipment 600 includes: a deposition device 601, a first transport device 602, the electroplating device 500 in the above embodiment, a cleaning device 603 and a second transport device 604. The deposition device 601 is configured to deposit the target metal layer 202 on at least a portion of the wafer surface (or substrate 201) to obtain a deposited wafer. The first transport device 602 is configured to transport the deposited wafer. The electroplating device 500 is configured to receive the deposited wafer transported by the first transport device 602, and electroplate the deposited wafer to obtain the electroplated wafer 200. The cleaning device 603 is configured to receive the electroplated wafer 200 from the electroplating device 500, and clean the electroplated wafer 200 to obtain a cleaned wafer. The second transport device 604 is configured to receive the cleaned wafer from the cleaning device 603, and transport the cleaned wafer to the next process link.

[0094] The deposition device 601 is exemplarily a CVD device or a PVD device. The first transport device 602 is exemplarily a robot. The cleaning device 603 exemplarily uses a water washing method to clean the electroplated wafer 200. The second transport device 604 is exemplarily a robot.

[0095] The basic principles of the present application are described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, effects, etc. mentioned in the present application are only examples and not limitations, and it cannot be considered that these advantages, strengths, effects, etc. are required by each embodiment of the present application. In addition, the specific details disclosed above are only for the purpose of illustration and ease of understanding, not for limitation, and the above details do not limit the present application to being implemented by adopting the above specific details.

[0096] The block diagrams of the devices, apparatuses, equipment, and systems involved in this application are only illustrative examples and are not intended to require or imply that they must be connected, arranged, and configured in the manner shown in the block diagram. As will be appreciated by those skilled in the art, these devices, apparatuses, equipment, and systems can be connected, arranged, and configured in any manner. Words such as "including", "comprising", "having", etc. are open words, referring to "including but not limited to", and can be used interchangeably with them. The words "or" and "and" used here refer to the words "and / or" and can be used interchangeably with them, unless the context clearly indicates otherwise. The words "such as" used here refer to the phrase "such as but not limited to", and can be used interchangeably with them.

[0097] It should also be noted that in the apparatus, device and method of the present application, each component or each step can be decomposed and / or recombined. Such decomposition and / or recombination should be regarded as equivalent solutions of the present application.

[0098] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of the present application. Therefore, the present application is not intended to be limited to the aspects shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

[0099] The above description has been given for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present application to the forms disclosed herein. Although multiple example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

Claims

1. A heterogeneous electroplating method, characterized in that: include: providing a wafer having an exposed target metal-containing layer on at least a portion of a surface; Placing the wafer in a first electroplating solution, and using a first electroplating process to electroplate an adhesion layer having a certain thickness on the target metal layer, wherein the target metal layer and the adhesion layer are heterogeneous metal layers, and the adhesion layer can be tightly attached to the target metal layer; The wafer is placed in a second electroplating solution, and a second electroplating process is used to electroplate the adhesion layer to form a main electroplating layer; wherein the main electroplating layer and the adhesion layer are the same metal layer, and the adhesion layer allows the main electroplating layer and the adhesion layer to form an integral layer during and after electroplating.

2. The heterogeneous electroplating method according to claim 1, characterized in that: The method of electroplating the target metal layer to form an adhesion layer having a certain thickness using a first electroplating process comprises: Under a preset first process parameter of the first electroplating process, applying a preset first process current to the surface of the target metal layer of the wafer; Under the first process parameters and the first process current, electroplating for a first preset time to form the adhesion layer of a certain thickness on the surface of the target metal layer of the wafer; The first process parameter includes at least one of a flow rate of the first electroplating solution, a temperature of the first electroplating solution, a rotation speed of the wafer, and a distance between a cathode and an anode.

3. The heterogeneous electroplating method according to claim 2, characterized in that: The first process current is a pulse current, and a period of a pulse wave in the pulse current ranges from 100 milliseconds to 200 milliseconds.

4. The heterogeneous electroplating method according to claim 3, characterized in that: The pulse current is a rectangular pulse wave, and the ratio of the time when the current density is greater than 0 to the time when the current density is equal to 0 in one cycle of the rectangular pulse wave is greater than or equal to 1:10 and less than or equal to 1:

2. Preferably, the ratio is 1:7 or 1:8 or 1:

9.

5. The heterogeneous electroplating method according to claim 3 or 4, characterized in that: The flow rate of the first electroplating solution is 8-50 liters / minute; and / or, the duty cycle of the load in the pulse current ranges from 60% to 90%; And / or, the current density of the peak value of the pulse current ranges from 4 amperes / square decimeter to 12 amperes / square decimeter; And / or, the first preset time is 3 seconds to 6 seconds.

6. The heterogeneous electroplating method according to any one of claims 1 to 4, characterized in that: The method of forming a main electroplating layer by electroplating on the adhesion layer using a second electroplating process comprises: Under the second process parameters of the second electroplating process, the adhesion layer is electroplated for a second preset time using a continuous direct current to form the main electroplating layer on the adhesion layer; The second process parameter includes at least one of a flow rate of the second electroplating solution, a temperature of the second electroplating solution, a rotation speed of the wafer, and a distance between a cathode and an anode.

7. The heterogeneous electroplating method according to claim 6, characterized in that: The flow rate of the second electroplating solution is 8-50 liters / minute; And / or, the current density of the direct current ranges from 0.6 A / dm2 to 1.2 A / dm2.

8. The heterogeneous electroplating method according to any one of claims 1 to 3, characterized in that: The first electroplating solution is the same as or different from the second electroplating solution.

9. The heterogeneous electroplating method according to any one of claims 1 to 3, characterized in that: The thickness of the adhesion layer is much smaller than the thickness of the main electroplating layer, and the thickness of the adhesion layer ranges from 2 nanometers to 10 nanometers.

10. An electroplating device, characterized in that: A method for electroplating a wafer having an exposed target metal-containing layer on at least a portion of a surface thereof, comprising: An electroplating chamber, wherein the electroplating chamber has an electroplating tank containing an electroplating solution; A fixture, configured to fix and adjust the posture of the wafer, and drive the wafer to be immersed in the plating solution or to be separated from the plating solution; an anode at least partially immersed in the electroplating solution; A direct current power supply, wherein the positive electrode of the direct current power supply is electrically connected to the anode, the negative electrode of the direct current power supply is electrically connected to the wafer, and the direct current power supply is used to output a linear current; A controller is communicatively connected to the DC power supply and is configured to control the DC power supply to output a pulse current of a first preset time so that an adhesion layer with a certain thickness is formed on the surface of the target metal layer, wherein the target metal layer and the adhesion layer are heterogeneous metal layers, and the adhesion layer can be tightly attached to the target metal layer, and to control the DC power supply to output a continuous DC current of a second preset time so that a main electroplating layer is formed on the surface of the adhesion layer, wherein the main electroplating layer and the adhesion layer are the same metal layer, and the adhesion layer allows the main electroplating layer and the adhesion layer to form an integral layer during and after electroplating.

11. A wafer processing device, characterized in that: include: A deposition device, configured to deposit a target metal layer on at least a portion of a surface of a wafer to obtain the wafer after deposition; A first transport device, configured to transport the wafer after deposition; The electroplating device of claim 10 is configured to receive the deposited wafer transported by the first transport device, and electroplate the deposited wafer to obtain the electroplated wafer; A cleaning device, configured to receive the electroplated wafer from the electroplating device, and clean the electroplated wafer to obtain the cleaned wafer; The second transport device is configured to receive the cleaned wafer from the cleaning device and transport the cleaned wafer to the next process link.

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