Ultrasonic cleaning device for wafer cleaning

[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

[0022] See Figure 1-4 , An ultrasonic cleaning device for wafer cleaning, including a cleaning chamber 1, a driving structure 2, a moving arm 3. The output end of the driving structure 2 penetrates the cleaning chamber 1 and is fixedly connected to a rotating arm 8, and the rotating arm 8 is eccentrically arranged The moving table 4, during cleaning, the moving table 4 fixes the wafer 9 with a suction cup, and the rotating arm 8 drives the wafer 9 to rotate eccentrically. The rotation track of the wafer 9 is as follows figure 2 As shown, a position sensor 7 is fixedly installed on one side of the rotating arm 8. Due to the eccentric rotation of the wafer 9, the wafer 9 intermittently passes over the position sensor 7. The position sensor 7 transmits the passing information of the wafer 9 to the control On the host, the rotation state of the wafer 9 is recognized. The moving arm 3 is equipped with a horizontally moving servo structure 5. The speed of the servo structure 5 increases at a uniform speed as it approaches the center of the moving table 4, which is adapted to the decrease of the point speed on the wafer 9 To ensure that the sound wave energy received by each point on the wafer 9 is consistent, the lower end of the servo structure 5 is equipped with an ultrasonic generating structure 6 that irradiates the sound wave energy linearly to ensure that the irradiation completely covers the surface of the wafer 9.

[0023] Among them, the moving table 4 is movably connected to the rotating arm 8. The rotating arm 8 is provided with a sliding rail for the moving table 4 to move. The starting point of the sliding rail of the rotating arm 8 is the center of the rotating arm 8, and the end and starting point of the sliding rail of the rotating arm 8 It is equipped with an electromagnetically controlled locking structure. The locking structure is an existing mature technology, so it will not be described. When the moving table 4 is at the starting position of the slide rail, the moving table 4 and the rotating arm 8 are coaxial, and the wafer 9 rotates at a uniform speed. When 4 is at the end position of the slide rail, wafer 9 rotates eccentrically.

[0024] Wherein, the mobile arm 3 is provided with at least two position marking structures of the servo structure 5, the moving end of the servo structure 5 is collinear with the mobile station 4, and the marking structure can be pressure sensors arranged at the starting and ending points of the servo structure 5, and the proximity Switch or photoelectric sensor, this embodiment only has photoelectric sensor. The photoelectric sensor transmits information with the control host, and calculates the movement state of the servo structure 5 through the servo structure 5 moving to the end position and the starting position, and then the servo structure 5 The movement parameters are detected and corrected.

[0025] Among them, the ultrasonic generating structure 6 is three side-by-side beak-shaped ultrasonic nozzles, and the middle nozzles are kept vertical, and the lower ends of the nozzles on both sides are inclined over the middle. The energy intensity of the middle ultrasonic nozzles of the ultrasonic generating structure 6 is less than the intensity on both sides. Finally, the irradiation energy of the three nozzles is the same, and the final ultrasonic effect on wafer 9 is as follows image 3 As shown, compared with the modification of the nozzles, this method has a lower cost, and while obliquely extending the irradiation length, the installation spacing of the three nozzles themselves is larger, and the design and installation are more flexible.

[0026] Among them, when the servo structure 5 moves to the end position, the most edge of the irradiation line segment of the ultrasonic generating structure 6 just reaches the center of the mobile station 4, and at this time, only the nozzle closest to the center is turned on, and the other nozzles are turned on after the steering is completed. The irradiation area of ​​the nozzle close to the center is scanned by only one nozzle, and the received energy is small, while the servo structure 5 requires a certain time for steering acceleration. Set the steering acceleration time reasonably to make up for the irradiation time here.

[0027] Among them, when the servo structure 5 moves to the starting position, the ultrasonic generating structure 6 is turned off. When the gap between the edges of the wafer 9 is the largest, the servo structure 5 starts to turn and turns on the ultrasonic generating structure 6 to ensure the uniform cleaning intensity at the edge. The position of the second sweep is the same to ensure the uniformity and identity of the cleaning.

[0028] The working principle of the present invention:

[0029] Install the wafer 9 on the mobile station 4 to ensure the centering of the mobile station 4 and the wafer 9, move the mobile station 4 to the eccentric position, set the parameters through the control host, start the position sensor 7, servo structure 5, servo The structure 5 detects the time when the edge gap of the wafer 9 passes, the control host calculates the operating state of the wafer 9, and when the edge space of the wafer 9 is maximized, the control servo structure 5 starts to move, and the ultrasonic generating structure 6 is turned on at the same time, the servo structure The moving speed of 5 is matched with the rotating speed of wafer 9 so that it can completely cover the entire surface of wafer 9 at one time and clean the surface of wafer 9. When it moves to the center of moving table 4, ultrasonic generating structure 6 is closed Two ultrasonic nozzles far away from the center, at the same time the servo structure 5 starts to turn and accelerate. After the servo structure 5 turns on, all the ultrasonic nozzles start to move from the center to the edge. Repeat for many times to complete the cleaning process.

[0030] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply one of these entities or operations. There is any such actual relationship or order between. Moreover, the terms "include", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes those that are not explicitly listed Other elements of, or also include elements inherent to this process, method, article or equipment.

[0031] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, and substitutions can be made to these embodiments without departing from the principle and spirit of the present invention. And variations, the scope of the present invention is defined by the appended claims and their equivalents.