CN223240165U

CN223240165U - Palladium plating device for wafer

Info

Publication number: CN223240165U
Application number: CN202422509710.9U
Authority: CN
Inventors: 卢思源; 梁加虎
Original assignee: Xinlian Integrated Circuit Manufacturing Co ltd
Current assignee: Xinlian Integrated Circuit Manufacturing Co ltd
Priority date: 2024-10-16
Filing date: 2024-10-16
Publication date: 2025-08-19
Anticipated expiration: 2034-10-16

Abstract

The utility model provides a wafer palladium plating device, comprising a first tank, a second tank, a circulation pipeline, and a gas-liquid mixing device. The first tank is used to contain a palladium solution for palladium plating wafers; the second tank is used to receive the palladium solution overflowing from the first tank; the circulation pipeline includes a liquid inlet and a liquid outlet, the liquid inlet connecting to the second tank and the liquid outlet connecting to the first tank, and the circulation pipeline is used to return the palladium solution in the second tank to the first tank; the gas-liquid mixing device is provided on the circulation pipeline and is used to mix the palladium solution from the second tank with gas. This wafer palladium plating device can improve the uniformity of the flow field within the tank, thereby improving the palladium plating effect, and can also reduce palladium precipitation within the tank, thereby increasing the service life of the device and reducing production costs.

Description

Palladium plating device for wafer

Technical Field

The utility model relates to the technical field of semiconductors, in particular to a wafer palladium plating device.

Background

In the semiconductor field, the chemical palladium (Pd) plating process is widely applied to protecting metal layers on semiconductor wafers, and particularly under the condition that electrode materials on the semiconductor wafers are mostly aluminum alloy, palladium plating can effectively protect difficult-to-plate substrates, prolong the service life of the wafers and improve the reliability and stability of products.

When the wafer is placed in the tank body to deposit the palladium coating, the thickness deviation of the palladium coating in the chip is overlarge due to uneven flow field in the tank body, and the poor quality is caused. Since palladium is extremely unstable in solution, no element capable of stabilizing its solution has been found at present. In addition, the solution in the tank body is accompanied with an autocatalytic reaction, namely, the palladium element always undergoes an autoxidation-reduction reaction, and free palladium ions are deposited on the circulating pipeline and the tank body, so that the service life of the tank body is influenced.

In order to improve the uniformity of the palladium plating layer, one way is to increase the uniformity of the flow field in the tank body through an N ₂ bubbling device. However, the N ₂ bubbler and the holder provided inside the tank accelerate precipitation of the tank, further deteriorating the yield. The bath is required to be rebuilt after the tank body is separated out, so that the production cost and the personnel burden are increased.

Disclosure of utility model

In the summary, a series of concepts in a simplified form are introduced, which will be further described in detail in the detailed description. The summary of the utility model is not intended to define the key features and essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

Aiming at the existing problems, the utility model provides a wafer palladium plating device which comprises a first tank body, a second tank body, a circulating pipeline and a gas-liquid mixing device, wherein,

The first groove body is used for containing palladium solution to plate palladium on the wafer;

The second tank body is used for receiving the palladium solution overflowed from the first tank body;

The circulating pipeline comprises a liquid inlet end and a liquid outlet end, the liquid inlet end is communicated with the second tank body, the liquid outlet end is communicated with the first tank body, and the circulating pipeline is used for refluxing palladium solution in the second tank body to the first tank body;

the gas-liquid mixing device is arranged on the circulating pipeline and used for mixing the palladium solution from the second tank body with gas.

The gas-liquid mixing device comprises a gas-liquid mixing cavity and a gas blowing structure arranged in the gas-liquid mixing cavity, wherein,

The gas-liquid mixing cavity comprises a liquid inlet and a liquid outlet, the circulating pipeline comprises a first section of circulating pipeline and a second section of circulating pipeline, the first section of circulating pipeline is communicated with the liquid inlet and the second tank body and is used for conveying palladium solution from the second tank body into the gas-liquid mixing cavity, and the second section of circulating pipeline is communicated with the liquid outlet and the first tank body and is used for conveying palladium solution mixed with gas into the first tank body;

The air blowing structure is communicated with the air pipeline, the air pipeline is used for conveying air to the air blowing structure, the air blowing structure is provided with at least one air blowing opening, and the air blowing opening is used for blowing air into the air-liquid mixing cavity.

Illustratively, the gas line is provided with a gas flow controller for controlling the flow of gas delivered to the gas-liquid mixing device.

Illustratively, the gas flow controller comprises a gas mass flow controller.

Illustratively, a time relay is also included that is coupled to the gas flow controller, and the time relay is closed when receiving a signal of ending the previous working procedure so as to trigger the gas flow controller to convey gas to the gas-liquid mixing device, and is opened after closing preset time so as to trigger the gas flow controller to stop conveying gas to the gas-liquid mixing device.

The first switching element is connected with the time relay, and the first switching element is closed when a wafer palladium plating signal is received, so that the time relay can receive a signal of ending the previous process, and is opened when the wafer palladium plating signal is not received, and the time relay cannot receive the signal of ending the previous process.

The second switching element is connected with a power supply of the gas flow controller, and is closed when the wafer palladium plating signal is received, so that the gas flow controller is powered up, and is opened when the wafer palladium plating signal is not received, and the gas flow controller is powered down.

Illustratively, there is a height difference between the top of the first tank and the top of the second tank such that palladium solution overflows from the top of the first tank to the second tank.

The circulation pipeline is also provided with a circulation pump, a heater and a filter

According to the wafer palladium plating device provided by the embodiment of the application, the uniformity of the flow field in the tank body can be improved, so that the palladium plating effect is improved, the palladium precipitation in the tank body can be reduced, the service life of the device is prolonged, and the production cost is reduced.

Drawings

The following drawings are included to provide an understanding of the utility model and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the utility model and their description to explain the principles of the utility model.

FIG. 1 shows a schematic diagram of a palladium plating device for a wafer according to one embodiment of the present utility model;

FIG. 2 shows a schematic view of a gas-liquid mixing apparatus according to an embodiment of the present utility model;

FIG. 3 illustrates a control schematic of a gas flow controller according to one embodiment of the present utility model;

fig. 4 shows a control circuit diagram of a gas flow controller according to an embodiment of the present utility model.

Detailed Description

In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present utility model. It will be apparent, however, to one skilled in the art that the utility model may be practiced without one or more of these details. In other instances, well-known features have not been described in detail in order to avoid obscuring the utility model.

It should be understood that the present utility model may be embodied in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the utility model to those skilled in the art. In the drawings, the size of layers and regions, as well as the relative sizes, may be exaggerated for clarity. Like numbers refer to like elements throughout.

It will be understood that when an element or layer is referred to as being "on," "adjacent," "connected to," or "coupled to" another element or layer, it can be directly on, adjacent, connected, or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" another element or layer, there are no intervening elements or layers present. It will be understood that, although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present utility model.

Spatially relative terms, such as "under," "below," "beneath," "under," "above," "over," and the like, may be used herein for ease of description to describe one element or feature's relationship to another element or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use and operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements or features described as "under" or "beneath" other elements would then be oriented "on" the other elements or features. Thus, the exemplary terms "below" and "under" may include both an upper and a lower orientation. The device may be otherwise oriented (rotated 90 degrees or other orientations) and the spatially relative descriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the utility model. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term "and/or" includes any and all combinations of the associated listed items.

In the following description, for a thorough understanding of the present utility model, detailed steps and structures will be presented in order to illustrate the technical solution presented by the present utility model. Preferred embodiments of the present utility model are described in detail below, however, the present utility model may have other embodiments in addition to these detailed descriptions.

A palladium plating wafer apparatus 100 according to an embodiment of the present application is described below with reference to fig. 1 to 4.

As shown in fig. 1, the palladium plating device for a wafer according to an embodiment of the present utility model includes a first tank 101, a second tank 102, a circulation line 103, and a gas-liquid mixing device 104. The first tank body 101 is used for containing palladium solution to plate palladium on a wafer, the second tank body 102 is used for receiving palladium solution overflowed from the first tank body 101, the circulating pipeline 103 is communicated with the first tank body 101 and the second tank body 102 and used for enabling the palladium solution in the second tank body 102 to flow back to the first tank body 102, and the gas-liquid mixing device 104 is arranged on the circulating pipeline 103 and used for mixing the palladium solution in the circulating pipeline 103 with gas. Among them, the gas to be mixed with the palladium solution is usually an inert gas, preferably nitrogen gas having high cleanliness.

Illustratively, the first tank 101 has a larger volume than the second tank 102, and the wafer may be placed in the palladium solution of the first tank 101 for palladium plating. By providing the second tank 102, the palladium solution can circulate between the first tank 101 and the second tank 102.

Illustratively, the first slot 101 is disposed adjacent to the second slot 102, and the second slot 102 may be disposed annularly around the first slot 101 or adjacent to one side of the first slot 101. When the volume of the palladium solution in the first tank body 101 is larger than the volume of the first tank body 101, the palladium solution in the first tank body 101 overflows into the second tank body 102 and flows back into the first tank body 101 through a circulating pipeline 103 connecting the first tank body 101 and the second tank body 102, so that the palladium solution is circulated between the first tank body 101 and the second tank body 102, and the palladium solution in the first tank body 101 is always kept at a set liquid level.

The circulation pipeline 103 is further provided with a gas-liquid mixing device 104 for mixing the palladium solution in the circulation pipeline 103 with the gas, so as to improve the flow field in the first tank 101 and improve the uniformity of the palladium plating layer of the wafer. Since the palladium solution and the gas are mixed between entering the first tank body 101, a bubbling pipe is not required to be arranged in the first tank body 101, the palladium can be prevented from being precipitated on the surface of the bubbling pipe, the service life of the first tank body 101 is prolonged, and the production cost is reduced. Illustratively, the gas-liquid mixing device 104 is disposed proximate to the first tank 101 to enhance the improving effect on the flow field within the first tank 101.

Illustratively, as shown in fig. 2, the gas-liquid mixing device 104 includes a gas-liquid mixing chamber 1041, and a liquid inlet 1042 and a liquid outlet 1043 are disposed on the gas-liquid mixing chamber 1041, and the liquid inlet 1042 and the liquid outlet 1043 are respectively communicated with the circulation pipeline 103. Specifically, the circulation line 103 includes a first circulation line and a second circulation line, the first circulation line is connected to the liquid inlet 1042 and the second tank 102, and is used for delivering the palladium solution from the second tank 102 to the gas-liquid mixing chamber 1041, and the second circulation line is connected to the liquid outlet 1043 and the first tank 101, and is used for delivering the palladium solution mixed with the gas to the first tank 101.

The gas-liquid mixing chamber 1041 is provided with a gas-blowing structure 1044, the gas-blowing structure 1044 is communicated with a gas pipeline 1046, and the gas pipeline 1046 is used for conveying gas to the gas-blowing structure 1044. The air-blowing structure 1044 is provided with at least one air-blowing port 1045, and the air-blowing port 1045 is used for blowing air into the air-liquid mixing cavity 1041, so that the air and the palladium solution are fully mixed before entering the first tank body 101, the flow field in the tank is improved, and the uniformity of the palladium plating layer on the surface of the wafer is improved. Wherein the gas mixed with the palladium solution includes, but is not limited to, nitrogen.

In the example of fig. 2, the gas-liquid mixing chamber 1041 is in the shape of a cube, the liquid inlet 1042 and the liquid outlet 1043 are disposed on opposite first and second surfaces of the cube, the gas inlet is disposed on a third surface perpendicular to the first and second surfaces, and the gas pipe 1046 penetrates the gas inlet and communicates with the gas blowing structure 1044. The air-blowing structure 1044 is a rectangular air-blowing pipe, and a plurality of air-blowing ports 1045 are uniformly distributed on the air-blowing structure 1044 so as to uniformly mix the air and the palladium solution. It should be noted that the gas-liquid mixing device shown in fig. 2 is only an example, the gas-liquid mixing chamber 1041 and the air-blowing structure 1044 may be configured in any other suitable shape, and the positions of the liquid inlet 1042, the liquid outlet 1043 and the air inlet may be set according to actual needs.

Further, a gas flow controller 105 is provided in the gas line 1046 for controlling the flow rate of the gas fed into the gas-liquid mixing device 104. Illustratively, the gas flow controller 105 is a gas Mass Flow Controller (MFC). The gas mass flow controller comprises a circuit board, a sensor, an air inlet and outlet pipeline joint, a diverter channel, a regulating valve and the like. After the gas enters the MFC, the majority of the flow flows through the diverter channel and a small portion enters the capillary tube inside the sensor. The structure of the diverter channel can realize the proportional management of the two gas flows. The sensor is preheated and heated, and the temperature inside the sensor is higher than the temperature of the entering air flow, and the mass flow of the small part of air is measured through capillary steel tube heat transfer and temperature difference calorimetric principles. The gas flow measured in this way has negligible effect on temperature and pressure. And inputting the flow detection signal detected by the sensor into a circuit board, amplifying and outputting the flow detection signal to finish the measurement of the gas mass flow. And a PID closed-loop automatic control function is added in the circuit board, the flow detection signal detected by the sensor is compared with the set signal, and the regulating valve is controlled based on the flow detection signal and the set signal, so that the flow detection signal is equal to the set signal, and the accurate control of the gas mass flow can be completed.

Automatic control of gas-liquid mixing can be achieved based on MFC. Specifically, as shown in fig. 3, when the previous process (for example, QDR (Quick Dump Rinse, rapid dumping and rinsing) process) of the wafer is finished, if the palladium plating process is to be performed on the wafer, the MFC is controlled to be opened in advance. After the palladium plating process is finished, the MFC is controlled to be closed in time, so that palladium precipitation in the first tank body 101 caused by cold gas introduced into the gas-liquid mixing device during idle is avoided.

Fig. 4 shows a control circuit diagram of the gas flow controller 105. The gas flow controller is connected with a time relay 401, and the time relay 401 is closed when receiving a signal of ending a previous process, so as to trigger the gas flow controller 105 to deliver gas to the gas-liquid mixing device, and is opened after closing for a preset time, so as to trigger the gas flow controller 105 to stop delivering gas to the gas-liquid mixing device.

Further, the palladium plating device for wafer further includes a first switching element 402 connected to the time relay 401, wherein the first switching element 402 is closed when the palladium plating signal for wafer is received, so that the time relay 401 can receive the signal of ending the previous process, and is opened when the palladium plating signal for wafer is not received, so that the time relay 401 cannot receive the signal of ending the previous process. Thus, the control scheme shown in fig. 3 can be realized, that is, the gas supply is automatically started when the wafer palladium plating signal is received and the signal of ending the previous process is received, the gas supply is automatically stopped after the timing is ended, and the gas supply is not performed if the wafer palladium plating signal is not received.

In some embodiments, the palladium plating device further includes a second switching element 403 connected to the power supply of the gas flow controller 105, where the second switching element 403 is closed when receiving the palladium plating signal of the wafer to supply power to the gas flow controller 105, and then starts to supply gas when the trigger signal is sent by the gas flow controller 105. The second switching element 403 is turned off when the palladium plating signal is not received, so that the gas flow controller 105 is powered off, and at this time, the gas flow controller 105 cannot supply gas.

Illustratively, the circulation line 103 is further provided with a pump 106, a heater 107, and a filter 108. Wherein the pump 106 is used for providing circulating power from the second tank 102 to the first tank 101, the heater 107 is used for heating the palladium solution to a set temperature, and the filter 108 is used for removing solid impurities in the palladium solution and preventing the solid impurities from adhering to the surface of the wafer, thereby improving the palladium plating effect.

In summary, the palladium plating device for wafers according to the embodiment of the utility model has the following advantages:

The novel pipeline structural design is adopted, so that the first tank body is free from physical contact, the flow field in the first tank body is effectively improved, precipitate aggregation in the tank can be avoided, the service life of the wafer palladium plating device is prolonged, and the production cost is reduced;

The gas-liquid real-time monitoring and mixing are realized through circuit design, and palladium precipitation in the first tank body caused by cold gas introduction during idle is avoided.

Although the illustrative embodiments have been described herein with reference to the accompanying drawings, it is to be understood that the above illustrative embodiments are merely illustrative and are not intended to limit the scope of the present application thereto. Various changes and modifications may be made therein by one of ordinary skill in the art without departing from the scope and spirit of the application. All such changes and modifications are intended to be included within the scope of the present application as set forth in the appended claims.

Similarly, it should be appreciated that in order to streamline the application and aid in understanding one or more of the various application aspects, various features of the application are sometimes grouped together in a single embodiment, figure, or description thereof in the description of exemplary embodiments of the application. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed application requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this application.

Furthermore, those skilled in the art will appreciate that while some embodiments described herein include some features but not others included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the application and form different embodiments. For example, in the claims, any of the claimed embodiments may be used in any combination.

It should be noted that the above-mentioned embodiments illustrate rather than limit the application, and that those skilled in the art will be able to design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The use of the words first, second, third, etc. do not denote any order. These words may be interpreted as names.

Claims

1. The wafer palladium plating device is characterized by comprising a first tank body, a second tank body, a circulating pipeline and a gas-liquid mixing device, wherein,

The second tank body is used for receiving palladium solution overflowed from the first tank body;

2. The apparatus of claim 1, wherein the gas-liquid mixing device comprises a gas-liquid mixing chamber and a gas-blowing structure disposed in the gas-liquid mixing chamber, wherein,

3. The palladium plating on wafer apparatus according to claim 2, wherein a gas flow controller is provided on the gas line for controlling a flow rate of the gas fed into the gas-liquid mixing device.

4. The palladium on wafer apparatus of claim 3, wherein the gas flow controller comprises a gas mass flow controller.

5. The palladium plating device of claim 3 or 4, further comprising a time relay connected to the gas flow controller, the time relay being closed to trigger the gas flow controller to deliver gas to the gas-liquid mixing device when receiving a signal of the end of a previous process, and being opened to trigger the gas flow controller to stop delivering gas to the gas-liquid mixing device after closing for a preset time.

6. The palladium on wafer apparatus of claim 5, further comprising a first switching element coupled to the time relay, the first switching element being closed upon receipt of a palladium on wafer signal to enable the time relay to receive a signal of the end of the previous process and being opened upon receipt of no palladium on wafer signal to disable the time relay from receiving the signal of the end of the previous process.

7. The palladium on wafer apparatus of claim 3 or 4, further comprising a second switching element connected to a power supply of the gas flow controller, the second switching element being closed when a palladium on wafer signal is received, powering the gas flow controller, and being open when a palladium on wafer signal is not received, powering the gas flow controller down.

8. The palladium plating device according to claim 1, wherein the first tank body is disposed adjacent to the second tank body, and the palladium solution overflows from the top of the first tank body to the second tank body.

9. The palladium plating on wafer apparatus according to claim 1, wherein the circulation line is further provided with a circulation pump, a heater and a filter.