Liquid supplementing device and copper electroplating equipment

Abstract

The utility model provides a liquid supplementing device and copper electroplating equipment. The liquid supplementing device comprises a liquid supplementing tank, a stored liquid detection unit and a liquid taking tank which are connected in sequence, a first concentration sensor and a floating ball are arranged in the stored liquid detection unit, and when the floating ball floats upwards, a pipeline between the stored liquid detection unit and the liquid taking tank is blocked; a second concentration sensor is arranged in the liquid taking tank. According to the liquid supplementing device, whether additives added into the liquid supplementing tank are correct or not can be judged according to the solution concentration of the stored liquid detection unit and the solution concentration of the liquid taking tank, and wrong additives are prevented from entering the liquid taking tank communicated with the electroplating liquid tank, so that the copper plating quality of the copper plating equipment is improved, the yield of processed wafers is improved, and the production cost is reduced. The cost of the semiconductor device is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductor processing, in particular to a liquid replenishing device and copper electroplating equipment. Background Art

[0002] Electroplating is the main process to complete copper filling. The copper electroplating solution is usually composed of light blue copper sulfate, sulfuric acid, water and organic additives. When power is applied between the silicon wafer (cathode) and copper (anode), a current is generated in the electroplating solution and an electric field is formed. Then, the copper at the anode reacts and transforms into copper ions and electrons, while the cathode reacts, and the copper ions combine with electrons to form copper plated on the surface of the silicon wafer. The main purpose of copper electroplating is to deposit a uniformly distributed, dense, hole-free, gap-free and other defect-free copper film on the silicon wafer.

[0003] Three organic additives are commonly used in electroplated copper interconnects: accelerators, suppressors, and levelers. In trench filling, the accelerator couples with the suppressor on the surface and mainly gathers at the bottom of the trench, reducing the adsorption and desorption thermodynamic constant, reducing the surface area of ​​the reaction electrode, and promoting copper deposition from the bottom up in the trench, thereby achieving hole-free filling. The suppressor adsorbs on the active points of grain growth, increases the electrochemical reaction resistance, and enhances the electrochemical polarization, thereby achieving the effect of grain refinement. The leveler is mainly a sticky macromolecule that is easier to adsorb on flat and protruding surfaces, and achieves the purpose of leveling by suppressing the grain growth of these parts; the leveler can also prevent the inhibitor from being adsorbed at the bottom of the trench. These three additives have different roles in copper electroplating and affect each other. The amount of additives used is relatively large, and the electroplating solution needs to be circulated continuously for 24 hours to ensure the concentration and freshness of the electroplating solution. However, the existing three additives are packaged in three bottles, each bottle is about 5 liters, and it will be used up in about 2 to 3 days. Then the equipment operator manually replenishes the three additives. Since organic additives are not supplied by the factory, the possibility of adding the wrong additives cannot be ruled out. The ECI concentration analyzer in the equipment generally takes three hours to feedback a set of data on the concentration of additives. Therefore, it is difficult to determine whether the wrong additives have been added. When the wrong additives are added, the wafer will not be filled well and there will be voids in the plated copper layer. The copper plating process in the semiconductor manufacturing process (FAB) cannot be reworked, and the wafer can only be scrapped. In addition, the poor flatness of the copper film will affect the grinding rate of the subsequent chemical mechanical polishing (CMP) and the flatness of the obtained product. Therefore, it is urgent to develop a device to prevent the wrong addition of additives.

[0004] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present invention, and therefore may include information that does not constitute prior art known to those skilled in the art. Utility Model Content

[0005] In response to the problems in the prior art, the purpose of the utility model is to provide a liquid replenishing device and a copper electroplating equipment. The liquid replenishing device can prevent erroneous additives from entering a liquid extraction tank connected to the electroplating liquid tank, thereby improving the quality of copper plating of the copper electroplating equipment, improving the yield of processed wafers, and reducing the cost of semiconductor devices.

[0006] A first aspect of the utility model provides a fluid replenishment device, comprising a fluid replenishment tank, a fluid storage detection unit and a fluid extraction tank connected in sequence;

[0007] The liquid storage detection unit is provided with a first concentration sensor and a float, and when the float floats up, the pipeline between the liquid storage detection unit and the liquid collection tank is blocked;

[0008] A second concentration sensor is arranged in the liquid taking tank.

[0009] According to a first aspect of the present utility model, the first concentration sensor is arranged at the bottom of the liquid storage detection unit; and / or

[0010] The second concentration sensor is arranged at the bottom of the liquid collection tank.

[0011] According to a first aspect of the utility model, the first concentration sensor is connected to a first display unit, and the first display unit is used to display first concentration information detected by the first concentration sensor;

[0012] The second concentration sensor is connected to a second display unit, and the second display unit is used to display second concentration information detected by the second concentration sensor.

[0013] According to the first aspect of the utility model, the fluid replenishing device also includes a pull rope connected to the float. When the float floats up to block the pipeline between the liquid storage detection unit and the liquid collection tank, pulling the pull rope can open the pipeline between the liquid storage detection unit and the liquid collection tank.

[0014] According to the first aspect of the utility model, the fluid infusion tank is funnel-shaped.

[0015] According to the first aspect of the utility model, the ratio of the volume of the liquid storage detection unit to the volume of the liquid extraction tank is 0.1 to 0.2.

[0016] A second aspect of the utility model provides a copper electroplating device, comprising a plurality of the liquid replenishing devices.

[0017] According to a second aspect of the utility model, the copper electroplating equipment further comprises an electrolyte tank connected to the plurality of liquid replenishing devices, and the electrolyte tank is configured to store the electrolyte plating solution.

[0018] According to the second aspect of the utility model, the copper electroplating equipment also includes an organic additive analyzer connected to the electrolyte tank, a portion of the electrolyte plating solution flow sample passes through the organic additive analyzer, and the organic additive analyzer is configured to determine the concentration of different substances in the passing electrolyte plating solution sample.

[0019] According to a second aspect of the utility model, the liquid replenishing device further comprises a pull rope connected to the float, and when the float floats up to block the pipeline between the liquid storage detection unit and the liquid collection tank, the pull rope can be pulled to open the pipeline between the liquid storage detection unit and the liquid collection tank;

[0020] The copper electroplating equipment further includes a controller and a pulling component for pulling the pull rope, wherein the controller is electrically connected to the pulling component and controls the pulling of the pull rope.

[0021] The liquid replenishing device of the utility model can judge whether the additive added to the liquid replenishing tank is correct through the solution concentration of the liquid storage detection unit and the liquid taking tank, thereby preventing the wrong additive from entering the liquid taking tank connected to the electroplating liquid tank, thereby improving the copper plating quality of the copper electroplating equipment, improving the yield of the wafer after processing, and reducing the cost of semiconductor devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Other features, objectives and advantages of the present invention will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings.

[0023] Figure 1 A schematic diagram of the structure of a fluid replenishing device according to an embodiment of the present invention; and

[0024] Figure 2 It is a schematic diagram of the partial structure of a copper electroplating device according to an embodiment of the utility model. DETAILED DESCRIPTION

[0025] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the embodiments set forth herein. On the contrary, these embodiments are provided so that the utility model will be comprehensive and complete, and the concept of the example embodiments will be fully conveyed to those skilled in the art. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the utility model, and should not be construed as limitations on the utility model. The same reference numerals in the figures represent the same or similar structures, and thus their repeated description will be omitted.

[0026] In the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0027] In the description of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or can communicate with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0028] The disclosure below provides many different embodiments or examples for realizing different structures of the utility model. In order to simplify the disclosure of the utility model, the components and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the utility model. In addition, the utility model can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplicity and clarity, and does not indicate the relationship between the various embodiments and / or settings discussed in itself. In addition, the utility model provides various specific examples of processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0029] In view of the existing technical problems, the utility model provides a liquid replenishing device and copper electroplating equipment, wherein the liquid replenishing device comprises a liquid replenishing tank, a liquid storage detection unit and a liquid collection tank connected in sequence; a first concentration sensor and a float are arranged in the liquid storage detection unit, and the float blocks the pipeline between the liquid storage detection unit and the liquid collection tank when floating; a second concentration sensor is arranged in the liquid collection tank. The liquid replenishing device of the utility model can judge whether the additive added to the liquid replenishing tank is correct through the solution concentration of the liquid storage detection unit and the liquid collection tank, and prevent the wrong additive from entering the liquid collection tank connected to the electroplating liquid tank, thereby improving the quality of copper plating of the copper electroplating equipment, improving the yield of the wafer after processing, and reducing the cost of semiconductor devices.

[0030] The structures of the liquid replenishing device and the copper electroplating equipment of the present invention are further described below in conjunction with the accompanying drawings and specific embodiments. It can be understood that the various specific embodiments are not intended to limit the protection scope of the present invention.

[0031] Figure 1 This is a schematic diagram of the structure of a fluid replenishment device according to an embodiment of the utility model. Specifically, the fluid replenishment device includes a fluid replenishment tank 1, a fluid storage detection unit 2, and a fluid collection tank 3 connected in sequence. The fluid replenishment tank 1 is connected to the fluid storage detection unit 2 through a pipeline A, and the fluid storage detection unit 2 is connected to the fluid collection tank 3 through a pipeline B. In actual use, the fluid collection tank 3 is connected to the electrolyte tank for replenishing the electrolyte plating solution in the electrolyte tank. A first concentration sensor 21 and a float 22 are provided in the fluid storage detection unit 2. The first concentration sensor 21 can be provided at the bottom of the fluid storage detection unit 2. When the float 22 floats up, it blocks the pipeline B between the fluid storage detection unit 2 and the fluid collection tank 3. A second concentration sensor 31 is provided in the fluid collection tank. The second concentration sensor 31 can be provided at the bottom of the fluid collection tank 3.

[0032] When a solution, such as an accelerator, inhibitor or leveler, needs to be added to the electrolyte tank through a liquid replenishing device, the liquid replenishing tank 1 can be funnel-shaped for the convenience of adding the solution, and the diameter of the upper port of the funnel-shaped liquid replenishing tank 1 can be greater than or equal to 10 cm. The density of the float 22 should be less than the solution replenished by the liquid replenishing tank 1, and the floating of the float 22 can be achieved by adding a solution to the liquid storage detection unit 2. Preferably, the ratio of the volume of the liquid storage detection unit 2 to the volume of the liquid extraction tank 3 is 0.1 to 0.2, so that when the liquid storage detection unit 2 is added with a solution, the float 22 floats to the opening of the pipeline B at the end of the liquid storage detection unit 2.

[0033] In actual use, the first concentration sensor 21 can be connected to the first display unit, and the first display unit is used to display the first concentration information detected by the first concentration sensor. Similarly, the second concentration sensor 31 can be connected to the second display unit, and the second display unit is used to display the second concentration information detected by the second concentration sensor. When the first concentration information is the same as the second concentration information, it can be considered that the solution flowing into the liquid storage detection unit 2 through the liquid replenishment tank 1 is the correct reaction solution. At this time, the float can be controlled so that it no longer blocks the pipeline B between the liquid storage detection unit 2 and the liquid collection tank 3. In one embodiment, the liquid replenishment device can also include a pull rope (not shown in the figure) connected to the float 22. After the solution float floats up to block the pipeline B between the liquid storage detection unit and the liquid collection tank, if the first concentration information is the same as the second concentration information, the pull rope can be pulled to open the pipeline B between the liquid storage detection unit and the liquid collection tank.

[0034] The utility model also provides a copper electroplating device comprising a plurality of the liquid replenishing devices. Figure 2The schematic diagram of the partial structure of the copper electroplating equipment of one embodiment of the utility model, wherein the copper electroplating equipment includes three refilling devices. The copper electroplating equipment also includes an electrolyte tank 9, and the electrolyte tank 9 is connected to each of the refilling devices. Of course, the electrolyte tank 9 and each of the refilling devices can be respectively provided with valve switches to control the components of the electrolyte plating solution stored in the electrolyte tank.

[0035] The replenishment device a is composed of a replenishment tank 1a, a liquid storage detection unit 2a provided with a first concentration sensor 21a and a float 22a, and a liquid collection tank 3a provided with a second concentration sensor 31a; the replenishment device b is composed of a replenishment tank 1b, a liquid storage detection unit 2b provided with a first concentration sensor 21b and a float 22b, and a liquid collection tank 3b provided with a second concentration sensor 31b; the replenishment device c is composed of a replenishment tank 1c, a liquid storage detection unit 2c provided with a first concentration sensor 21c and a float 22c, and a liquid collection tank 3c provided with a second concentration sensor 31c. The three replenishment devices can be used to replenish accelerators, inhibitors and levelers, respectively. The accelerator can be a sulfur compound, such as bis(3-sulfopropyl) disulfide, 3-mercapto-1-propyl sulfonic acid or its derivatives. The inhibitor can include polyethylene glycol, polypropylene glycol, polyoxyethylene-polyoxypropylene copolymer or derivatives of the above substances. The leveling agent may be an alkyl polyimine compound or an organic sulfonate compound, such as 1-(2-hydroxyethyl)-2-imidazolidinone, 4-mercaptopyridine, 2-mercaptothiazoline, ethylenethiourea, thiourea or derivatives thereof. According to the replenished solution, the volume of each liquid storage detection unit / liquid collection tank, etc., each liquid replenishing device may select different types of first concentration sensors, second concentration sensors and floats.

[0036] The concentration of various additives in the electrolyte plating solution can be adjusted by controlling the amount of solution entering the electrolyte tank 9 from the liquid taking tanks of each liquid replenishing device. For example, the concentration of the accelerator in the electrolyte plating solution can be controlled to 3 ml / L, the concentration of the inhibitor can be controlled to 10 ml / L, and the concentration of the leveler can be controlled to 5 ml / L. The copper electroplating equipment can also include an organic additive analyzer 8 connected to the electrolyte tank 9, and a portion of the electrolyte plating solution flow sample passes through the organic additive analyzer 8, and the organic additive analyzer 8 is configured to determine the concentration of different substances in the electrolyte plating solution sample passing through. The organic additive analyzer 8 can be a commercial electroplating additive analyzer.

[0037] In actual use, the liquid replenishing device also includes a pull rope connected to the float. When the float floats up and blocks the pipeline between the liquid storage detection unit and the liquid collection tank, the pull rope can be pulled to open the pipeline between the liquid storage detection unit and the liquid collection tank. The pull rope can be manually controlled. For ease of use, the copper electroplating equipment can also include a controller and a pulling component for pulling the pull rope. The controller is electrically connected to the pulling component and controls the pulling of the pull rope. The controller can be electrically connected to the first concentration sensor and the second concentration sensor of each liquid replenishing device. When it is determined that the liquid concentration detected by the first concentration sensor of a certain liquid replenishing device is the same as the liquid concentration detected by the second concentration sensor, and the electrolyte tank needs to be supplemented with the solution of the liquid replenishing device, the controller controls the pulling component to pull the pull rope, and the float no longer blocks the pipeline between the liquid storage detection unit and the liquid collection tank of the liquid replenishing device, thereby realizing the addition of the solution.

[0038] Of course, the copper electroplating equipment may also include a warning module, etc. The warning module may be connected to the controller, and the controller may be electrically connected to the first concentration sensor and the second concentration sensor of each liquid replenishing device. When the concentration detected by the first concentration sensor of a liquid replenishing device is different from the concentration detected by the first concentration sensor, the controller sends an instruction to the warning module to send a warning signal. At this time, the operator can disassemble the liquid replenishing tank and the liquid storage detection unit of the liquid replenishing device, clean them and reuse them.

[0039] It should be pointed out that in the technical solutions of the liquid replenishing device and the copper electroplating equipment of the utility model, the various functional modules and module units included therein, such as the controller, etc., can correspond to the specific hardware circuits in the integrated circuit structure. Therefore, it only involves the improvement of the specific hardware circuits. The hardware part is not just a carrier for executing control software or computer programs. Therefore, solving the corresponding technical problems and obtaining the corresponding technical effects do not involve the application of any control software or computer programs. In other words, the utility model only utilizes the improvements in the hardware circuit structure involved in these modules and units to solve the technical problems to be solved and obtain the corresponding technical effects, and does not need to be assisted by specific control software or computer programs to achieve the corresponding functions.

[0040] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations of the present invention. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present invention.

[0041] The above contents are further detailed descriptions of the present invention in combination with specific preferred implementations, and the specific implementation of the present invention cannot be considered to be limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. A fluid replenishing device, characterized in that: It includes a liquid replenishing tank, a liquid storage detection unit and a liquid extraction tank which are connected in sequence; The liquid storage detection unit is provided with a first concentration sensor and a float, and when the float floats up, the pipeline between the liquid storage detection unit and the liquid collection tank is blocked; A second concentration sensor is arranged in the liquid taking tank.

2. The fluid replenishing device according to claim 1, characterized in that: The first concentration sensor is disposed at the bottom of the liquid storage detection unit; and / or The second concentration sensor is arranged at the bottom of the liquid collection tank.

3. The fluid replenishing device according to claim 1, characterized in that: The first concentration sensor is connected to a first display unit, and the first display unit is used to display first concentration information detected by the first concentration sensor; The second concentration sensor is connected to a second display unit, and the second display unit is used to display second concentration information detected by the second concentration sensor.

4. The fluid replenishing device according to claim 1, characterized in that: The liquid replenishing device also includes a pull rope connected to the float. When the float floats up to block the pipeline between the liquid storage detection unit and the liquid collection tank, the pull rope can be pulled to open the pipeline between the liquid storage detection unit and the liquid collection tank.

5. The fluid replenishing device according to claim 1, characterized in that: The fluid infusion tank is funnel-shaped.

6. The fluid replenishing device according to claim 1, characterized in that: The ratio of the volume of the liquid storage detection unit to the volume of the liquid collection tank is 0.1 to 0.

2.

7. A copper electroplating device, characterized in that: The invention comprises a plurality of fluid infusion devices according to any one of claims 1 to 6.

8. The copper electroplating equipment according to claim 7, characterized in that: It also includes an electrolyte tank connected to the plurality of liquid replenishing devices, wherein the electrolyte tank is configured to store an electrolyte plating solution.

9. The copper electroplating equipment according to claim 8, characterized in that: Also included is an organic additive analyzer connected to the electrolyte tank, through which a portion of the electrolyte plating solution flow sample passes, and the organic additive analyzer is configured to determine the concentration of different substances in the electrolyte plating solution sample passing through.

10. The copper electroplating equipment according to claim 7, characterized in that: The liquid replenishing device further comprises a pull rope connected to the float, and when the float floats up to block the pipeline between the liquid storage detection unit and the liquid collection tank, the pull rope can be pulled to open the pipeline between the liquid storage detection unit and the liquid collection tank; The copper electroplating equipment further includes a controller and a pulling component for pulling the pull rope, wherein the controller is electrically connected to the pulling component and controls the pulling of the pull rope.

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