CN117711991A - A kind of wafer tank cleaning equipment - Google Patents

Abstract

The invention belongs to the technical field of wafer wet methods, in particular to wafer groove type cleaning equipment, which comprises a cleaning groove body and a vibrator cavity connected with the bottom of the cleaning groove body, wherein a separation plate is arranged in the cleaning groove body and divides the cleaning groove body into a cleaning cavity for storing cleaning liquid and a conducting cavity for storing pure water; the cleaning cavity is positioned above the isolation plate, and the conducting cavity is positioned below the isolation plate; at least 1 sound wave vibrator group is arranged in the vibrator cavity at intervals, the sound wave vibrator group comprises an ultrasonic vibrator and megasonic vibrators, and each sound wave vibrator group is electrically connected with a sound wave controller. The beneficial effects are that: simultaneously, an ultrasonic vibrator and a megasonic vibrator are arranged, and the cleaning efficiency is improved through the generated complex frequency sound wave. The conduction cavity is used for sound wave and heat propagation simultaneously, so that the volume of the equipment can be reduced, and the heating device is arranged in the conduction cavity, so that the service life of the heating device can be prolonged.

Description

A kind of wafer tank cleaning equipment

Technical field

The present invention relates to the technical field of wafer cleaning, and in particular to a wafer tank cleaning equipment.

Background technique

In the semiconductor manufacturing process, wafer cleaning is the most commonly used process step. It mainly uses tank cleaning or single-wafer cleaning to remove electrostatically adsorbed fine particles on the wafer surface and other chemicals remaining in the semiconductor manufacturing process. Tank-type wafer cleaning equipment often needs to heat the cleaning liquid to achieve good cleaning effects when cleaning wafers. In the past, the heating method of tank-type wafer cleaning equipment was to directly extend the heating device into the chemical liquid for heating. This method has The following defects:

1. Uneven heating results in different temperatures of the cleaning fluid near different wafers, affecting the stability of the cleaning effect.

2. The cleaning fluid will corrode the heating device, seriously affecting the service life of the heating device and causing an increase in production costs.

In addition, tank cleaning equipment is often combined with ultrasonic and megasonic generators. The principle is to use the sonic flow and cavitation generated by ultrasonic and megasonic generators. The sonic flow directly resonates with the fine particles on the surface of the wafer, thereby removing the fine particles; the principle of cavitation is that the sonic generator generates small bubbles, which float upward, and these bubbles continue to expand and close under the action of the sound field, thus Impact and vibration are produced on the wafer surface to remove surface contaminants. The frequencies of sound waves generated by ultrasonic generators and megasonic generators are different. When ultrasonic and megasonic generators are used to clean particles on the wafer surface, when the frequency of the sound waves is lower, the bubble size is larger and the density is lower; when the frequency becomes When large, the bubble size decreases and the density increases. The larger the bubble size, the greater the impact force generated when it collapses, and the stronger the ability to remove particles, but at the same time, the greater the damage to the wafer surface.

In the past, tank cleaning machines often only included ultrasonic generators or megasonic generators, and the diameter of particles adsorbed on the wafer surface may be large or small. A single generator cannot effectively remove particles of different diameters, even if the tank cleaning process Ultrasonic cleaning and megasonic cleaning cannot clean particles of all diameters. For this reason, we need to find a method that can achieve continuous sound wave frequency.

In view of this, it is urgent to propose a new wafer tank cleaning equipment to solve the above technical problems.

Contents of the invention

Based on the existing technical problems, the present invention proposes a wafer tank cleaning equipment.

The invention proposes a wafer tank cleaning equipment, which includes a cleaning tank and a vibrator cavity connected to the bottom of the cleaning tank. An isolation plate is provided inside the cleaning tank, and the isolation plate separates the cleaning tank. The body is divided into a cleaning cavity for storing cleaning liquid and a conduction cavity for storing pure water; the cleaning cavity is located above the isolation plate, and the conduction cavity is located below the isolation plate; the vibrator cavity is spaced with at least 1 acoustic wave vibrator group, the acoustic wave vibrator group includes an ultrasonic vibrator and a megasonic vibrator, and each acoustic wave vibrator group is electrically connected to the acoustic wave controller.

Preferably, at least four positioning posts are provided on the isolation plate for positioning the wafer basket.

Preferably, the volume of the cleaning chamber is larger than the volume of the conduction chamber.

Preferably, the wafer tank cleaning equipment further includes:

At least 2 first liquid inlet pipes, the first liquid inlet pipe is connected to the cleaning chamber and used to introduce different cleaning liquids or pure water into the cleaning chamber;

The first liquid outlet is connected to the cleaning chamber and is used to discharge the contaminated mixed cleaning liquid.

Preferably, the wafer tank cleaning equipment also includes:

a second liquid inlet pipe, the second liquid inlet pipe is connected to the conduction cavity and is used to pass pure water into the conduction cavity, and the pure water is used to conduct heat and sound waves at the same time;

A second liquid outlet pipe is connected to the conduction cavity and is used to discharge pure water in the conduction cavity.

Preferably, at least one heating device is provided inside the conduction cavity to heat the pure water in the conduction cavity and maintain the temperature, and the heating device is configured as a heating rod.

Preferably, a mounting plate is provided below the vibrator cavity, a through hole is provided on the bottom wall of the vibrator cavity, a notch is provided at a position of the mounting plate corresponding to the through hole, and the second liquid outlet The tube passes through the vibrator cavity and extends from the via hole.

Preferably, the ultrasonic vibrator and megasonic vibrator pass through the bottom cavity wall of the conduction cavity and protrude into the conduction cavity, and are sealed between the ultrasonic vibrator and megasonic vibrator and the bottom cavity wall of the conduction cavity. ;

The vibrator cavity is also provided with at least one air port for balancing the air pressure inside the vibrator cavity.

Preferably, the sound wave controller is configured as a phase adjuster, and the phase adjuster is used to periodically change the phase of the sound waves emitted by the ultrasonic vibrator and the megasonic vibrator.

Preferably, mounting brackets are provided on both sides of the cleaning tank, and the mounting brackets are used to install the cleaning tank to the main body of the equipment.

The beneficial effects of the present invention are:

1. Set up a vibrator cavity. There are multiple sets of vibrator groups in the vibrator cavity, and the phase of the sound wave is adjusted through the sound wave controller. The sound wave multiplexing can be realized. Through the sound wave flow and cavitation generated by the sound wave, it can achieve single frequency than before. The ultrasonic generator or megasonic generator of the trough cleaning machine has better cleaning effect.

2. Set up a conduction cavity to combine the heating device of the tank cleaning machine and the cavity for sound wave transmission of the megasonic vibrator into one, which greatly saves the size and production cost of the tank cleaning machine.

3. Setting the heating device in the conduction cavity and conducting heat conduction through pure water not only achieves uniform heating heat distribution, but also avoids the problem that the heating device itself is corroded due to direct contact with the cleaning fluid.

Description of the drawings

Figure 1 is a schematic diagram of the main structure of a wafer tank cleaning equipment;

Figure 2 is a front view of a wafer tank cleaning equipment;

Figure 3 is a main cross-sectional view of a wafer tank cleaning equipment;

Figure 4 is a cross-sectional view of the conduction cavity of a wafer tank cleaning equipment;

Figure 5 is a vibrator installation diagram of a wafer tank cleaning equipment;

Figure 6 is a bottom view of a wafer tank cleaning equipment;

In the picture: 1. Cleaning tank; 2. Vibrator cavity; 3. Mounting frame; 4. Mounting plate; 11. Cleaning cavity; 12. Conducting cavity; 13. Isolation plate; 21. Vibrator group; 22. Air port; 23. Through hole; 41, notch; 111, first liquid inlet pipe; 112, first liquid outlet; 121, second liquid inlet pipe; 122, second liquid outlet pipe; 123, heating device; 131, positioning column.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. However, it should be noted that these embodiments do not limit the present invention. Those of ordinary skill in the art can rely on these implementations to Equivalent transformations or substitutions of functions, methods, or structures made in this manner shall all fall within the protection scope of the present invention.

It should be understood that the terms "center", "longitudinal", "lateral", "vertical", "horizontal", "axial", "radial", "above", "below", etc. indicate an orientation or position The relationship is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the present technical solution and simplifying the description. In particular, the term "upper" refers to the direction of the opening of the wafer cleaning tank, and the term "lower" refers to the direction opposite thereto.

Referring to Figures 1 to 6, this embodiment discloses a specific implementation of a wafer tank cleaning equipment, including a cleaning tank 1 and a vibrator cavity 2 connected to the bottom of the cleaning tank 1. The cleaning tank An isolation plate 13 is provided inside the body 1. The isolation plate 13 separates the cleaning tank body 1 into a cleaning cavity 11 for storing cleaning liquid and a conduction cavity 12 for storing pure water; the cleaning cavity 12 is located in the isolation Above the plate 13, the conduction cavity 12 is located below the isolation plate 13; at least one acoustic wave vibrator group 21 is spaced in the vibrator cavity 2, and the acoustic wave vibrator group 21 includes an ultrasonic vibrator and a megasonic vibrator, each The acoustic wave vibrator group 21 is electrically connected to the acoustic wave controller (not shown in the figure).

In the past, tank cleaning machines often only included ultrasonic vibrators or megasonic vibrators. The main reason is that the working environments of ultrasonic vibrators and megasonic vibrators in wafer cleaning equipment are different. The ultrasonic vibrators are directly installed at the bottom or side wall of the cleaning tank, directly work; in order to achieve better cleaning results, wafer tank cleaning equipment using megasonic vibrators is generally equipped with a conduction cavity, which is filled with pure water, and the megasonic vibrator works in the conduction cavity. The operating frequency of the ultrasonic vibrator is generally 15-200kHz. It mainly uses the cavitation effect of the liquid to generate small bubbles. The bubbles float and explode near the wafer surface. The energy generated by the explosion takes away the stains and particles on the wafer surface, which can effectively clean the wafer. Particles with a circular surface diameter greater than 0.4 μm. The working frequency of megasonic vibrators is generally 800-1000kHz. It uses high-frequency acoustic energy to form high-speed micro-water flows in the cleaning solution to continuously impact the wafer surface, which can effectively clean particles with a diameter less than 0.2 μm on the wafer surface. In the actual production process, the diameter of particles adsorbed on the wafer surface may be large or small. Wafer cleaning equipment equipped with a single-frequency acoustic vibrator cannot effectively remove particles of different diameters.

The ultrasonic vibrator and megasonic vibrator pass through the bottom cavity wall of the conduction cavity 2 and protrude into the conduction cavity 2 . Sealing setting: In this embodiment, the selected operating frequency of the ultrasonic vibrator is 40-200kHz, and the selected operating frequency of the megasonic vibrator is 800-1000kHz. Further, each acoustic wave vibrator group 21 is electrically connected to an acoustic wave controller, and the acoustic wave controller is configured as a phase adjuster. The phase adjuster periodically changes the intensity of the ultrasonic wave vibrator and the megasonic wave vibrator. The phase of the sound wave is used to adjust the distribution of the sound wave frequency in the time domain and space. After passing through the conduction cavity 2, it can better produce cavitation and controllable sound wave flow, and better control particles of various diameters on the wafer surface. of cleaning.

Furthermore, the vibrator cavity 2 is also provided with at least one air port 22 for balancing the air pressure inside the vibrator cavity. Since the vibrator generates a large amount of heat when working, it will continue to heat the air inside the vibrator cavity 2. Increasing the air pressure inside the vibrator cavity 2 will cause the heat to be unable to be discharged in time if the air is not circulated. The continuously generated heat and the increased air pressure will affect the working state of the vibrator, which may seriously reduce the life of the vibrator or even damage it. After adding the air port 22, the air pressure inside and outside the vibrator cavity 2 can be kept balanced, and the circulating air can take away heat in time, ensuring the operating stability of the vibrator and effectively extending the working life of the vibrator.

The isolation plate 13 is provided with at least four positioning posts 131. After the external transport device sends the flower basket containing wafers into the cleaning tank 1, it needs to position the flower basket. Providing the positioning posts 131 that match the flower basket helps to assist external handling devices, such as robots, in positioning, making it easier for the external handling devices to pick and place. In addition, it can help maintain the stability of the wafer during the cleaning process.

The wafer tank cleaning equipment also includes at least two first liquid inlet pipes 111 , and the first liquid inlet pipes 111 are connected to the cleaning chamber 11 . In the semiconductor manufacturing process, the formulas of cleaning fluids used in tank cleaning equipment may be different for different processes. For example, when tank cleaning equipment is used after the grinding process, the main contaminants are silicon-containing particles; For tank cleaning equipment in the glue process, the main pollutants are mainly the colloid to be removed, other chemical liquid residues and particulate matter. For different processes, different cleaning solutions are required. In this regard, the wafer tank cleaning equipment provided by the present invention has at least two first liquid inlet pipes 111, which can pass into different chemical liquids and pure water to form Predetermined proportions of cleaning fluids for different cleaning processes. A first liquid outlet 112 is also provided near the bottom wall of the cleaning cavity 11 for discharging the contaminated mixed cleaning liquid.

The wafer tank cleaning equipment also includes a second liquid inlet pipe 121 and a second liquid outlet pipe 122. The second liquid inlet pipe 121 is connected to the conduction chamber 12 and is used to pass pure liquid into the conduction cavity 12. water, the second liquid outlet pipe 122 is connected to the bottom cavity wall of the conduction cavity 12 and is used to discharge pure water in the conduction cavity 12 . At least one heating device 123 is also provided inside the conduction chamber 12. The heating device 123 is configured as a heating rod to heat the pure water in the conduction chamber 12 and maintain the temperature.

In wafer tank cleaning equipment, the cleaning fluid often requires a certain temperature to promote chemical reactions and improve wafer cleaning efficiency. Therefore, during the wafer cleaning process, the chemical liquid needs to be heated and kept warm. The traditional method is to directly extend the heating device into the cleaning liquid for heating and heat preservation. The cleaning liquid is generally corrosive, and it will inevitably cause damage in the long run. Affects the service life of the heating device. Furthermore, this heating method will also lead to uneven temperature distribution in the cleaning tank. Obviously, in this heating method, the heat source is only the heating device, which will cause the temperature of the cleaning liquid close to the heating device to be relatively high, while the temperature of the cleaning liquid far away from the heating device will be relatively high. The temperature of some cleaning fluids in the heating device is relatively low, which will inevitably lead to uneven wafer cleaning results.

In the wafer tank cleaning equipment of the present invention, the pure water in the conduction cavity 12 acts as a heat conduction carrier, and the heating device 123 extends into the conduction cavity 12 to heat the pure water. When the pure water Once the temperature exceeds the temperature of the cleaning fluid, the heat transfer process begins, which has the following advantages:

1. The heating device 123 does not contact the cleaning liquid, but only contacts pure water, and will not be corroded, which can greatly extend the service life of the heating device 123.

2. The heating process is relatively gentle, the uniformity of heat conduction is better, and the uniformity of wafer cleaning effect is better.

It can be seen from the above description that the pure water in the conduction cavity 12 is used to conduct heat and sound waves at the same time, combining the heating component and the sound wave conduction component in the previous wafer tank cleaning equipment into one, and realizing the modular Grouping can greatly reduce the horizontal space occupied by the cleaning tank.

Furthermore, mounting brackets 3 are provided on both sides of the cleaning tank 1 , and a mounting plate 4 is provided below the vibrator cavity 2 . The mounting bracket 3 and the mounting plate 4 are used to attach the cleaning tank 1 And the vibrator cavity 2 is installed on the equipment body. The bottom wall of the vibrator cavity 2 is provided with a through hole 23. The mounting plate 4 is provided with a notch 41 at a position corresponding to the through hole 23. The second liquid outlet pipe 122 passes through the vibrator cavity 2 and is protrude from the via hole 33 .

The process flow of a wafer tank cleaning equipment provided by the invention is:

The first liquid inlet pipe injects different cleaning liquids or pure water into the cleaning cavity according to a preset ratio;

Then, the second liquid inlet injects pure water into the conduction cavity until the conduction cavity is filled;

After the pure water fills the conduction cavity, the heating device heats the pure water and indirectly heats the cleaning liquid in the cleaning cavity to a predetermined temperature through thermal conduction;

After the cleaning fluid is heated to a predetermined temperature, the external handling device places the flower basket containing the group of wafers to be cleaned into the cleaning unit and immerses it in the cleaning fluid;

After the flower basket is positioned, the opening of the cleaning tank 1 is closed, the sonic vibrator group starts to work, and the phase of the sound waves emitted by the ultrasonic vibrator and the megasonic vibrator is periodically adjusted through the sonic controller;

After the cleaning is completed, the external transport device will send out the cleaned wafers for drying process.

To sum up, the present invention provides a wafer tank cleaning equipment, which includes a cleaning tank and a vibrator cavity connected to the bottom of the cleaning tank. An isolation plate is provided inside the cleaning tank, and the isolation plate will The cleaning tank is divided into a cleaning cavity for storing cleaning liquid and a conduction cavity for storing pure water; the cleaning cavity is located above the isolation plate, and the conduction cavity is located below the isolation plate; inside the vibrator cavity At least one acoustic wave vibrator group is provided at intervals. The acoustic wave vibrator group includes an ultrasonic vibrator and a megasonic wave vibrator. Each acoustic wave vibrator group is electrically connected to the acoustic wave controller. The beneficial effect is that the ultrasonic vibrator and the megasonic vibrator are set at the same time to improve the cleaning efficiency through the generated complex frequency sound waves. The conduction cavity is used for both sound wave and heat transmission, which can reduce the volume of the equipment. The heating device is arranged in the conduction cavity, which can extend the service life of the heating device.

The above are only preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person familiar with the technical field can, within the technical scope disclosed in the present invention, use the technical solutions of the present invention and its Equivalent substitutions or changes of the inventive concept shall be included in the protection scope of the present invention.

Claims (8)

1. A wafer tank cleaning equipment, including a cleaning tank and a vibrator cavity connected to the bottom of the cleaning tank. It is characterized in that an isolation plate is provided inside the cleaning tank, and the isolation plate connects the The cleaning tank is divided into a cleaning cavity for storing cleaning liquid and a conduction cavity for storing pure water; the cleaning cavity is located above the isolation plate, and the conduction cavity is located below the isolation plate; the vibrator cavity is spaced apart There is at least one sonic vibrator group, the sonic vibrator group includes an ultrasonic vibrator and a megasonic vibrator, and each sonic vibrator group is electrically connected to the sonic controller; Also includes: At least 2 first liquid inlet pipes, the first liquid inlet pipe is connected to the cleaning chamber and used to introduce different cleaning liquids or pure water into the cleaning chamber; A first liquid outlet, connected to the cleaning chamber, is used to discharge the contaminated mixed cleaning liquid; a second liquid inlet pipe, the second liquid inlet pipe is connected to the conduction cavity and is used to pass pure water into the conduction cavity, and the pure water is used to conduct heat and sound waves at the same time; A second liquid outlet pipe is connected to the conduction cavity and is used to discharge pure water in the conduction cavity. 2. A wafer tank cleaning equipment according to claim 1, characterized in that at least four positioning posts are provided on the isolation plate for positioning the wafer flower basket. 3. The wafer tank cleaning equipment according to claim 1, characterized in that: the volume of the cleaning chamber is larger than the volume of the conduction chamber. 4. A wafer tank cleaning equipment according to claim 1, characterized in that: at least one heating device is provided inside the conduction cavity to heat the pure water in the conduction cavity and maintain the temperature. The heating device is configured as a heating rod. 5. A wafer tank cleaning equipment according to claim 1, characterized in that: a mounting plate is provided below the vibrator cavity, a via hole is provided on the bottom wall of the vibrator cavity, and the mounting plate is connected to A notch is provided at a position corresponding to the via hole, and the second liquid outlet tube passes through the vibrator cavity and extends from the via hole. 6. A wafer tank cleaning equipment according to claim 1, characterized in that: The ultrasonic vibrator and megasonic vibrator pass through the bottom cavity wall of the conduction cavity and protrude into the conduction cavity, and are sealed and arranged between the ultrasonic vibrator and megasonic vibrator and the bottom cavity wall of the conduction cavity; The vibrator cavity is also provided with at least one air port for balancing the air pressure inside the vibrator cavity. 7. A wafer tank cleaning equipment according to claim 1, characterized in that: the acoustic wave controller is configured as a phase adjuster, and the phase adjuster is used to periodically change the ultrasonic vibrator and the The phase of the sound wave emitted by the megasonic oscillator. 8. A wafer tank cleaning equipment according to claim 1, characterized in that: mounting brackets are provided on both sides of the cleaning tank body, and the mounting brackets are used to install the cleaning tank body to the equipment main body. superior.