Ultrasonic cleaning device

Abstract

The utility model discloses an ultrasonic cleaning device which comprises a rotating table used for rotating after a wafer is loaded, and a fixing plate is arranged above the rotating table in a lifting mode. The conduction part is arranged below the fixing plate, a containing cavity is formed between the fixing plate and the conduction part, and the lower surface of the conduction part is located above the wafer and covers the wafer; the conducting liquid circulating assembly is arranged on the fixing plate and is connected with the accommodating cavity; the cleaning liquid input pipe is arranged in the fixing plate and the conduction part in a penetrating manner and is used for conveying the cleaning liquid to the wafer and then forming a water film on the upper surface of the wafer; the ultrasonic generating part is arranged in the accommodating cavity; the ultrasonic wave generated by the ultrasonic wave generating part is conducted to the water film formed on the wafer through the conducting liquid and the conducting part, and finally is transmitted to the whole upper surface of the wafer through the water film, so that the whole surface of the wafer is synchronously subjected to ultrasonic cleaning, the cleaning frequencies of all parts of the wafer are consistent during cleaning, the cleaning effect and efficiency are good, and the service life of the wafer is prolonged. The structure is simple and practical.

Description

Technical Field

[0001] The utility model relates to the technical field of wafer processing, in particular to an ultrasonic cleaning device for wafer cleaning. Background Art

[0002] A wafer refers to a silicon wafer used for fabricating silicon semiconductor circuits, and its raw material is silicon. High-purity polysilicon is dissolved and doped with a silicon crystal seed, and then slowly pulled out to form a cylindrical single-crystal silicon. The cleaning of the wafer surface in the semiconductor industry is to remove particulate contaminants, organic contaminants, and metal contaminants on the wafer surface to make its cleanliness meet the material processing standards.

[0003] In the existing process, when cleaning wafers, whether it is a multi-wafer cleaning or a single-wafer cleaning device, ultrasonic cleaning is used to remove the particulate matter that is difficult to clean between the wafer components. Different acoustic frequencies correspond to different particle sizes and removal effects. The ultrasonic nozzle is widely used in wafer cleaning. According to different usage scenarios, the nozzle styles are also diverse. The common ones are the single-point non-contact nozzle plus swing-arm rotation cleaning or the local medium contact plus swing-arm rotation method.

[0004] However, it is found in actual use that when cleaning by the single-point non-contact or local contact cleaning method, the cleaning efficiency of both is poor, and the cleaning frequencies of each part are inconsistent, and the cleaning effect cannot meet the requirements. At the same time, the ultrasonic nozzle needs to be moved for cleaning through a swing arm, the cleaning speed is poor, and the structure of the whole device is relatively complex and cannot meet the existing requirements. Summary of the Utility Model

[0005] The purpose of the utility model is to provide an ultrasonic cleaning device to overcome the deficiencies of the prior art, with consistent cleaning frequencies for each part of the wafer, good cleaning effect, and simple and practical structure.

[0006] 2]To achieve the above object, the technical solution adopted by the utility model is: an ultrasonic cleaning device, comprising:

[0007] A rotating table for loading the wafer and rotating;

[0008] A fixing plate which is arranged above the rotating table and can be lifted and lowered;

[0009] A conduction component which is arranged below the fixing plate, and an accommodation cavity is formed between the fixing plate and the conduction component. The lower surface of the conduction component is located above the wafer and covers the wafer; [[ID=]33]

[0010] A conduction liquid circulation component which is arranged on the fixing plate and is connected to the accommodation cavity to realize the circulation of the conduction liquid;

[0011] The cleaning liquid input pipe is disposed through the fixed plate and the conduction component to send the cleaning liquid onto the wafer to form a water film on the upper surface of the wafer.

[0012] The ultrasonic generating unit is disposed in the accommodation cavity to conduct ultrasonic waves to the wafer through the conduction liquid and the conduction component via the water film.

[0013] Furthermore, the ultrasonic generating unit includes an oscillator mounted on the lower surface of the fixed plate; the oscillator wire on the oscillator leads out from the oscillator wire outlet; the oscillator wire outlet is disposed on the fixed plate.

[0014] Furthermore, the conduction component is a high-purity quartz plate.

[0015] Furthermore, a groove is provided on the upper surface of the conduction component; after the fixed plate is connected to the conduction component through a plurality of locking members, the lower surface of the fixed plate and the groove form the accommodation cavity; a sealing ring is further provided between the fixed plate and the conduction component.

[0016] Furthermore, the conduction liquid circulation assembly includes a conduction liquid inlet and a conduction liquid outlet disposed on the fixed plate, and the conduction liquid inlet and the conduction liquid outlet communicate with the accommodation cavity respectively.

[0017] Furthermore, the gap between the lower surface of the conduction component and the wafer is 1 - 3 mm.

[0018] Furthermore, both the conduction component and the oscillator are circular.

[0019] Furthermore, the conduction liquid is ultrapure water.

[0020] Due to the application of the above technical solution, the present utility model has the following advantages compared with the prior art:

[0021] For the ultrasonic cleaning device of the present utility model, the ultrasonic waves emitted by the ultrasonic generating unit with a set frequency are conducted to the bottom surface of the conduction component through the conduction liquid and the conduction component, and the conduction component transmits the ultrasonic waves to the entire surface of the wafer through the water film formed on the wafer, realizing synchronous ultrasonic cleaning of the entire surface of the wafer. The rotating table drives the wafer to rotate to throw out the cleaning liquid and take away the removed particulate matters. In this cleaning method, the cleaning frequencies of all parts of the wafer are the same, and the cleaning effect and efficiency are good. At the same time, the use of the swing arm is avoided, and the structure is simple.

[0022] Secondly, the conduction liquid can also cool the ultrasonic generating unit to prevent the ultrasonic generating unit from overheating and reducing its service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The technical solution of the present utility model will be further described below with reference to the accompanying drawings:

[0024] Figure 1 Schematic three-dimensional structure diagram of an embodiment of the present utility model;

[0025] Figure 2 is Figure 1 exploded schematic three-dimensional structure diagram;

[0026] Figure 3 Front view of the present utility model;

[0027] Figure 4 is Figure 3 internal cross-sectional view;

[0028] Figure 5 is Figure 4 partial schematic diagram;

[0029] Wherein: rotating table 1, wafer 2, fixing plate 3, conduction component 4, cleaning liquid input pipe 5, conduction liquid circulation assembly 7, groove 40, locking piece 41, sealing ring 42, vibrator 60, vibrator lead outlet 61, conduction liquid inlet 70, conduction liquid outlet 71. Specific implementation manners

[0030] In order to enable those skilled in the art to better understand the solution of this application, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of this application.

[0031] The present utility model provides an ultrasonic cleaning device to solve the problems in the prior art that the ultrasonic cleaning of wafers adopts a single-point non-contact or local contact cleaning method, resulting in poor cleaning efficiency, inconsistent cleaning frequencies of different parts of the wafer, the cleaning effect not meeting the requirements, and at the same time, the need to move the nozzle through a swing arm for cleaning, with poor cleaning rate and complex structure.

[0032] For the sake of easy understanding, the specific process in the embodiments of this application will be described below. Please refer to Figures 1 to 3, an ultrasonic cleaning device in an embodiment of the present application includes a rotating table 1, a fixing plate 3, a conduction component 4, a cleaning liquid input pipe 5, and an ultrasonic generating part; a plurality of positioning PINs for positioning and clamping wafers are arranged on the rotating table 1, and the rotating table 1 drives the wafer 2 to rotate; the fixing plate 3 is arranged above the rotating table 1 in a liftable manner; the conduction component 4 is arranged below the fixing plate 3, and a receiving cavity is formed between the fixing plate 3 and the conduction component 4. The lower surface of the conduction component 4 is located above the wafer 2 and covers the wafer 2; a conduction liquid circulation assembly 7 is arranged on the fixing plate 3, and the conduction liquid circulation assembly 7 is connected to the receiving cavity to realize the circulation of the conduction liquid; the cleaning liquid input pipe 5 penetrates through the fixing plate 3 and the conduction component 4 to send the cleaning liquid onto the wafer 2 to form a water film on the upper surface of the wafer; the ultrasonic generating part is arranged in the receiving cavity to transmit ultrasonic waves to the wafer through the conduction liquid and the conduction component 4 through the water film.

[0033] For the ultrasonic cleaning device of the present utility model, the ultrasonic waves emitted by the ultrasonic generating part with a set frequency are conducted to the bottom surface of the conduction component 4 through the conduction liquid and the conduction component 4. The conduction component 4 transmits the ultrasonic waves to the entire surface of the wafer through the water film formed on the wafer 2, realizing ultrasonic cleaning of the entire surface of the wafer 2 synchronously. The rotating table 1 drives the wafer 2 to rotate to throw out the cleaning liquid and take away the removed particulate matter. In such a cleaning method, the cleaning frequency of each part of the wafer is the same, and the cleaning effect and efficiency are good. At the same time, the use of a swing arm is avoided, and the structure is simple.

[0034] Based on Figure 2 and Figure 5 , further, the ultrasonic generating part includes a disk-shaped oscillator 60, and the oscillator 60 is installed on the lower surface of the fixing plate 3; the oscillator wire on the oscillator 60 is led out from the oscillator wire outlet 61; the oscillator wire outlet 60 is arranged on the fixing plate 3. During operation, after the oscillator wire is connected to an external power supply and started, the oscillator 60 is driven to generate ultrasonic waves, and the ultrasonic waves are transmitted downward through the conduction liquid to the transmission component 4.

[0035] Further, the conduction component 4 is a high-purity quartz plate. The high-purity quartz plate has good efficiency in transmitting ultrasonic waves, and the thickness of the conduction component 4 is relatively thin, further improving the conduction efficiency; in this embodiment, the conduction component 4 is disk-shaped, and the conduction component 4 can completely cover the upper surface of the wafer, so that the transmitted ultrasonic waves can be transmitted to the water film on the upper surface of the wafer 2 over the entire surface, realizing ultrasonic cleaning of the entire surface of the wafer. The cleaning frequency of each part of the wafer is the same, and the cleaning effect is good.

[0036] Further, a groove 40 is provided on the upper surface of the conduction component 4. After the fixing plate 3 is connected to the conduction component 4 through a plurality of locking pieces 41, a receiving cavity is formed between the lower surface of the fixing plate 3 and the groove 40, and the receiving cavity is used for placing the oscillator 60 and circulating the conduction liquid.

[0037] In addition, a sealing ring 42 is further provided between the fixing plate 3 and the conduction component 4 to increase the sealing performance between the fixing plate 3 and the conduction component 4.

[0038] The conduction liquid circulation assembly 7 includes a conduction liquid inlet 70 and a conduction liquid outlet 71. The conduction liquid inlet 70 and the conduction liquid outlet 71 are arranged on the upper surface of the fixing plate 3, and the conduction liquid inlet 70 and the conduction liquid outlet 71 communicate with the receiving cavity respectively, thus forming a circulation channel for the conduction liquid.

[0039] Secondly, the conduction liquid is high-purity water. When the conduction liquid circulates, in addition to conducting sound waves, it can also cool down the oscillator 60, avoid the heating problem caused by the repeated work of the oscillator 60, and can greatly extend the service life of the oscillator 60.

[0040] Further, in order to ensure the conduction efficiency of the conduction component 4 for ultrasonic waves, the gap between the conduction component 4 and the wafer 2 set in this embodiment is 1 - 3 mm to ensure that the ultrasonic waves can be effectively conducted to the water film on the wafer.

[0041] During actual operation, based on Figure 5 , first, the fixing plate 3 is moved downward as a whole through an external lifting mechanism, so that the gap between the lower surface of the conduction component 4 and the wafer 2 is 3 mm.

[0042] At this time, the conduction liquid flows in from the conduction liquid inlet 70 as shown in the figure and then flows out from the conduction liquid outlet 71. The conduction liquid can conduct the ultrasonic waves generated by the oscillator 60 and cool and protect the oscillator 60 at the same time.

[0043] The cleaning liquid continuously flows downward from the cleaning liquid input pipe 5 to the surface of the wafer 2 located on the rotating table 1, thereby forming a water film with a thickness of 3 mm on the surface of the wafer 2. Then the oscillator 60 starts to work to generate ultrasonic waves. The ultrasonic waves are transmitted downward through the conduction liquid and the conduction component 4 to the water film formed on the wafer. Since the ultrasonic waves are conducted through the conduction component 4 for whole-surface conduction, the ultrasonic waves are also conducted to the upper surface of the wafer through the whole surface of the water film, realizing the whole-surface synchronous cleaning of the wafer, and the cleaning frequencies of all parts of the wafer are the same.

[0044] After cleaning for a period of time, the rotating table 1 drives the wafer 2 to rotate, driving the cleaning liquid to be thrown to the outer circle of the wafer 2. Due to the action of centrifugal force, the cleaning liquid with removed particles is thrown out, thus effectively realizing the whole-surface ultrasonic cleaning of the wafer.

[0045] In summary, the ultrasonic cleaning device of the present utility model can achieve synchronous cleaning of the entire surface of the wafer. The cleaning frequencies of all parts of the wafer are consistent, there is no need for a swing arm for transfer, the cleaning efficiency is high, and the cleaning effect is good.

[0046] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present application.

Claims

1. An ultrasonic cleaning device, characterized in that, Comprising: A rotating table for loading a wafer and then rotating it; A fixed plate which is arranged above the rotating table and can be lifted and lowered; A conduction component which is arranged below the fixed plate, and an accommodation cavity is formed between the fixed plate and the conduction component, and the lower surface of the conduction component is located above the wafer and covers the wafer; A conduction liquid circulation assembly which is arranged on the fixed plate and is connected to the accommodation cavity for realizing the circulation of the conduction liquid; A cleaning liquid input pipe which penetrates through the fixed plate and the conduction component for sending the cleaning liquid onto the wafer to form a water film on the upper surface of the wafer; An ultrasonic generating part which is arranged in the accommodation cavity for conducting ultrasonic waves to the wafer through the conduction liquid and the conduction component via the water film.

2. The ultrasonic cleaning device according to claim 1, characterized in that: The ultrasonic generating part includes an oscillator, and the oscillator is installed on the lower surface of the fixed plate; the oscillator wire on the oscillator leads out from the oscillator wire outlet; the oscillator wire outlet is arranged on the fixed plate.

3. The ultrasonic cleaning device according to claim 1, characterized in that: The conduction component is a high-purity quartz plate.

4. The ultrasonic cleaning device according to claim 1, wherein: A groove is arranged on the upper surface of the conduction component; after the fixed plate is connected to the conduction component through a plurality of locking pieces, the lower surface of the fixed plate and the groove form the accommodation cavity; a sealing ring is further arranged between the fixed plate and the conduction component.

5. The ultrasonic cleaning device according to claim 1, characterized in that: The conduction liquid circulation assembly includes a conduction liquid inlet and a conduction liquid outlet which are arranged on the fixed plate, and the conduction liquid inlet and the conduction liquid outlet are respectively communicated with the accommodation cavity.

6. The ultrasonic cleaning device according to claim 1, wherein: The gap between the lower surface of the conduction component and the wafer is 1-3 mm.

7. The ultrasonic cleaning device according to claim 2, wherein: Both the conduction component and the oscillator are circular.

8. The ultrasonic cleaning device according to claim 1, characterized in that: The conduction liquid is ultrapure water.

Images