Array-type megasonic cleaning apparatus for cleaning wafers

Abstract

To provide a cleaning device in which a plurality of wafers can be placed and cleaned simultaneously, the area occupied by a cleaning tank being minimized, and consistency in the effect of wafer cleaning is ensured. [Solution] An array-type megasonic cleaning apparatus for cleaning wafers includes a cleaning tank, and first and second drive shafts, each 60 mm to 350 mm long, arranged parallel to each other within the cleaning tank and rotatable around its own centerline by a drive unit. At least two first locking grooves are formed along the length of the first drive shaft, and at least two second locking grooves are formed along the length of the second drive shaft, each corresponding to the first locking grooves. Multiple wafers can be placed on the first and second locking grooves by engaging with the first and second locking grooves. The first and second drive shafts are configured to be located on either side of the wafer's center axis and rotate in the same direction, frictionally driving and cleaning multiple wafers simultaneously.

Description

[Technical Field]

[0001] The present invention relates to the field of semiconductor integrated circuit chip manufacturing, and more particularly to an array type megasonic cleaning apparatus for cleaning wafers. [Background technology]

[0002] The cleaning function of each process unit is to remove polishing liquid residue and dirt particles from the wafer. There are three process units: a megasonic cleaning unit, a brushing cleaning unit, and a drying unit. The principle of megasonic cleaning is that a high-frequency oscillating current is generated from a high-frequency AC power source, which is converted into a mechanical vibration wave through a converter and transmitted to the cleaning medium, causing two phenomena in the liquid: cavitation and acoustic flow. The combined force of these two phenomena removes particles adhering to the wafer surface. Megasonic cleaning causes minimal damage to the surface and can remove particles smaller than 0.2 μm.

[0003] In a conventional method (CN206966220U), wafers are placed in a cleaning tank, separated by partitions, and cleaned using megasonics. In this method, the wafers are stationary in the cleaning tank, resulting in poor cleaning uniformity and consistency.

[0004] The requirement for throughput per unit time for chemical mechanical planarization (CMP) equipment is currently becoming increasingly higher, and the working efficiency of the traditional single-groove monolithic megasonic cleaning mode does not meet the cleaning requirements. If multiple monolithic megasonic cleaning tanks are installed to increase throughput, the megasonic cleaning space will become too large, the transport distance will be long, and the transport efficiency will decrease, which will not meet the production requirements. Summary of the Invention

[0005] The present invention has been made to solve the problems of the prior art described above, and its purpose is to provide an array-type megasonic cleaning apparatus for cleaning wafers that can clean multiple wafers simultaneously, satisfy high throughput, and ensure uniformity and consistency of cleaning.

[0006] The technical means adopted by the present invention to solve the technical problems are as follows: 1. An array type megasonic cleaning apparatus for cleaning wafers, comprising: a cleaning tank having a cleaning solution and a megasonic generator therein; The cleaning tank includes a first main drive shaft and a second main drive shaft that are arranged parallel to each other within the cleaning tank and are rotatable around their own centerlines in the circumferential direction by the drive unit.

[0007] The first and second drive shafts have lengths of 60 mm to 350 mm.

[0008] The first drive shaft has at least two first locking grooves along its length, and the second drive shaft has at least two second locking grooves along its length, the second locking grooves being arranged to correspond to the first locking grooves.

[0009] A plurality of wafers can be placed on the wafer holder by linking the first and second locking grooves, and the first and second drive shafts are configured to be located on either side of the central axis of the wafer.

[0010] The first and second drive shafts rotate in the same direction, and multiple wafers can be rotated by friction drive simultaneously to achieve cleaning.

[0011] The driven shaft further includes at least two positioning grooves, the positioning grooves and the first and second locking grooves being located in the same vertical plane, and the edge of the wafer falls into the positioning grooves.

[0012] The cleaning tank of this invention can accommodate multiple wafers for simultaneous cleaning, minimizing the cleaning tank's footprint and ensuring consistent wafer cleaning results while maintaining consistent cleaning efficiency. When cleaning multiple wafers, the amount of cleaning solution used in the cleaning tank can be reduced, reducing costs. Wafer transfer is more convenient, as a single robot arm can support multiple wafers for simultaneous loading and unloading.

[0013] Furthermore, the driven shaft is configured to be positioned below the wafer and offset from the central axis of the wafer, so that the distance between the megasonic cleaning device and the wafer 5 is relatively short, resulting in a higher cleaning effect.

[0014] Furthermore, a gap is formed between the inner wall of the positioning groove and the wafer, which reduces frictional resistance to rotation of the wafer and enables the positioning groove to restrict excessive fluttering of the wafer.

[0015] Furthermore, the side surface of the positioning groove contacts the wafer to rotate the driven shaft, and the driven shaft is circumscribed by a rotation speed detection unit to monitor the rotation speed of the wafer, and there is a gap between the bottom surface of the positioning groove and the wafer. The wafer rotates the driven shaft synchronously through the positioning groove to facilitate monitoring of the rotation speed of the wafer. Since the bottom surface of the positioning groove does not contact the wafer, processing accuracy decreases, making processing easier.

[0016] Furthermore, the first and second drive shafts have the same rotation speed.

[0017] Furthermore, one end of the first drive shaft and / or the second drive shaft is connected to the side wall of the cleaning tank, and the other end is connected to the drive unit, or one end of the first drive shaft and / or the second drive shaft is suspended in the cleaning tank, and the other end is connected to the drive unit.

[0018] Furthermore, the driven shaft includes a first shaft body and a second shaft body, which are arranged coaxially, and one end of each of the first shaft body and the second shaft body is arranged in a suspended state.

[0019] Furthermore, the first and / or second drive shafts include a left shaft and a right shaft that are coaxially arranged and rotated by a drive unit, respectively. The left shaft of the first drive shaft and the left shaft of the second drive shaft are linked together to be used for rotary cleaning of one batch of wafers, and the left shaft of the second drive shaft and the right shaft of the second drive shaft are linked together to be used for rotary cleaning of another batch of wafers. The rotation of the two batches of wafers is relatively independent and can be made to have different rotation speeds, thereby achieving the purpose of realizing two different cleaning rhythms in one cleaning tank, further diversifying cleaning methods, and increasing usage flexibility.

[0020] Furthermore, the left and right shafts rotate at different speeds.

[0021] The beneficial effects of this invention are that multiple wafers can be placed in the cleaning tank and cleaned simultaneously, while maintaining the same cleaning efficiency. This minimizes the cleaning tank's footprint and ensures consistent wafer cleaning results, meeting the demand for higher throughput. Rotating wafers in the cleaning tank solves the problem of poor cleaning uniformity and consistency. When cleaning multiple wafers, the amount of cleaning solution used in the cleaning tank can be reduced, reducing costs. For wafer transfer, a single robot arm can be used to support multiple wafers for simultaneous loading and unloading, making transfer more convenient. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a perspective view of an array type megasonic cleaning device according to embodiment 1 of the present invention; [Figure 2] 1 is a plan view of an array type megasonic cleaning device according to embodiment 1 of the present invention; FIG. [Figure 3] 1 is a cross-sectional view of an array type megasonic cleaning device according to embodiment 1 of the present invention; [Figure 4]1 is a longitudinal sectional view of an array type megasonic cleaning device according to embodiment 1 of the present invention; FIG. [Figure 5] 1 is a perspective view of an array type megasonic cleaning device according to a first embodiment of the present invention, excluding the cleaning tank; [Figure 6] 1 is a plan view of an array type megasonic cleaning device according to embodiment 2 of the present invention; [Figure 7] 1 is a cross-sectional view of an array type megasonic cleaning device according to embodiment 2 of the present invention; [Figure 8] 1 is a perspective view of an array type megasonic cleaning device according to a second embodiment of the present invention, excluding the cleaning tank; DETAILED DESCRIPTION OF THE INVENTION

[0023] In order to allow those skilled in the art to better understand the method of the present invention, the following clearly and completely describes the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and are not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without any creative efforts should fall within the scope of the claims of the present invention.

[0024] Embodiment 1 1. An array type megasonic cleaning apparatus for cleaning wafers, comprising: a cleaning tank 3 containing a cleaning liquid therein and having a megasonic generator 31 at the bottom; a first drive shaft 1 that is provided in the cleaning tank 3 and that can rotate around its own center line in a circumferential direction by being driven by a drive unit 4, and has an axial length of 60 mm to 350 mm; and a second main drive shaft 2 having an axial length of 60 mm to 350 mm, which is provided in the cleaning tank 3 parallel to the first main drive shaft 1 and can be rotated circumferentially around its center line by a drive unit. Here, the drive unit may be the same as or different from the drive unit of the first main drive shaft 1.

[0025] The first drive shaft 1 is provided with at least two first locking grooves 11 along its length.

[0026] The second drive shaft 2 is provided with at least two second locking grooves 21 along its length, and the second locking grooves 21 are provided to correspond to the first locking grooves 11. Here, correspondence means that the number and positions of the first locking grooves 11 and the second locking grooves 21 correspond to each other. Specifically, this means that the projection of the first locking grooves 11 onto the side wall of the cleaning tank 3 and the projection of the second locking grooves 21 onto the side wall of the cleaning tank 3 overlap, or at least partially overlap.

[0027] As a result, two or more wafers 5 can be placed by linking the first locking groove 11 and the second locking groove 21, and the first drive shaft 1 and the second drive shaft 2 are configured to be located on both sides of the central axis of the wafer 5. That is, each wafer 5 is placed in a corresponding pair of the first locking groove 11 and the second locking groove 21, and the side walls of the wafer 5 come into contact with the bottom walls of the first locking groove 11 and the second locking groove 21.

[0028] The first drive shaft 1 and the second drive shaft 2 rotate in the same direction, and can simultaneously drive and rotate the wafer 5 by frictional force, thereby realizing rotational cleaning of the wafer 5.

[0029] Of course, it is also possible to provide a driven shaft 6 provided with at least two positioning grooves 63 located in the same vertical plane as the first locking groove 11 and the second locking groove 21. More specifically, the positioning grooves 63 correspond in number to the first locking groove 11 and the second locking groove 21, and also in position to the first locking groove 11 and the second locking groove 21. The edge portion of the wafer 5 falls into the positioning groove 63.

[0030] The driven shaft 6 is configured to be positioned below the wafer 5 and offset from the central axis of the wafer 5. Therefore, the distance between the megasonic cleaning device 31 and the wafer 5 is relatively short, resulting in a higher cleaning effect.

[0031] A gap is formed between the inner wall of the positioning groove 63 and the wafer 5. At this time, there is a gap between the bottom wall of the positioning groove 63 and the side wall of the wafer 5, and there is also a gap between the side wall of the positioning groove 63 and the surface of the wafer 5.

[0032] Of course, in other embodiments, the side surface of the positioning groove 63 comes into contact with the surface of the wafer 5, causing the driven shaft 6 to rotate by friction, but there is a gap between the bottom surface of the positioning groove 63 and the wafer 5. In this case, the driven shaft 6 is circumscribed by the rotation speed detection unit 64, and the driven shaft 6 rotates in synchronization with the wafer 5. Therefore, by monitoring the rotation speed of the driven shaft 6, the rotation speed of the wafer 5 can be indirectly monitored.

[0033] 1 to 5, in this embodiment, the first main drive shaft 1 and the second main drive shaft 2 are supplied with power from the same drive unit 4, in other words, the first main drive shaft 1 and the second main drive shaft 2 have the same rotation speed. The connection method between the first main drive shaft 1 and the second main drive shaft 2 and the drive unit 4 is not particularly limited and may be a direct motor drive, a belt transmission, or the like.

[0034] One end of the first driving shaft 1 is rotatably connected to the side wall of the cleaning tank 3, and the other end is connected to the drive unit 4. The second driving shaft 2 is arranged parallel to the first driving shaft 1, and one end of the second driving shaft 2 is rotatably connected to the side wall of the cleaning tank 3, and the other end is connected to the drive unit 4. The driven shaft 6 has both ends connected to the side wall of the cleaning tank 3.

[0035] In other embodiments, the above configuration may be replaced by one end of the first drive shaft 1 being connected to the drive unit 4 and the other end not being rotatably connected to the side wall of the cleaning tank 3 but being suspended in the air within the cleaning tank 3, one end of the second drive shaft 2 being connected to the drive unit 4 and the other end not being rotatably connected to the side wall of the cleaning tank 3 but being suspended in the air within the cleaning tank 3, and one end of the driven shaft 6 being connected to the side wall of the cleaning tank 3 and the other end being suspended in the air within the cleaning tank 3.

[0036] Of course, combinations are also possible, i.e., within the same cleaning tank 3, one end of the first driving shaft 1 is connected to the drive unit 4 and the other end is suspended in the cleaning tank 3; one end of the first driving shaft 1 is connected to the drive unit 4 and the other end is connected to the side wall of the cleaning tank 3; one end of the second driving shaft 2 is connected to the drive unit 4 and the other end is rotatably connected to the side wall of the cleaning tank 3; one end of the second driving shaft 2 is connected to the drive unit 4 and the other end is suspended in the cleaning tank 3; one end of the driven shaft 6 is connected to the side wall of the cleaning tank 3 and the other end is suspended in the cleaning tank 3; both ends of the driven shaft 6 are connected to the side wall of the cleaning tank 3; the first driving shaft 1 and the second driving shaft 2 are driven by the same drive unit 4; the first driving shaft 1 and the second driving shaft 2 are driven by different drive units 4; no driven shaft 6 is installed; and these nine features can be combined as desired and are not limited. The three wafers 5 are respectively engaged between the three first engagement grooves 11 on the first drive shaft 1 and the three second engagement grooves 21 on the second drive shaft 2. When the first drive shaft 1 and the second drive shaft 2 rotate in the same direction, the three wafers 5 rotate simultaneously and are cleaned simultaneously with the rotation.

[0037] 4, the driven shaft 6 is located below the wafer 5, between the first drive shaft 1 and the second drive shaft 2, and is offset from the central axis of the wafer 5. Therefore, with the driven shaft 6 located on the central axis of the wafer 5, the distance between the first drive shaft and the second drive shaft is maximized, ensuring the stability of the wafer 5, while the distance between the megasonic cleaning device 31 at the bottom of the cleaning tank 3 and the wafer 5 can be relatively minimized, resulting in better cleaning results.

[0038] To ensure consistent wafer cleaning results, complex closed-loop flow control is required for each chemical in the cleaning solution in each cleaning tank 3 to precisely control the cleaning solution blend ratio. Cleaning multiple wafers 5 in the same cleaning tank 3 ensures that each wafer 5 is exposed to the same cleaning solution blend ratio, ensuring cleaning consistency and reducing liquid blending costs. Furthermore, accommodating multiple wafers 5 and multiple cleaning tanks in one cleaning tank 3 reduces the total volume of cleaning solution compared to accommodating a single wafer in one tank. Multiple wafers 5 are placed in one cleaning tank 3 with close spacing between each wafer 5, allowing a single robot arm to support and simultaneously load and unload multiple wafers 5.

[0039] Embodiment 2 As shown in Figures 6 to 8, the difference between this embodiment and embodiment 1 is that the first drive shaft 1 includes a left shaft body 12 and a right shaft body 13 arranged coaxially, with one adjacent end of each being suspended in air; the second drive shaft 2 includes a left shaft body 22 and a right shaft body 23 arranged coaxially, with one adjacent end of each being suspended in air; the left shaft body 12 of the first drive shaft 1 and the left shaft body 22 of the second drive shaft 2 are driven in synchronous rotation by the same drive unit 4; and the right shaft body 13 of the first drive shaft 1 and the right shaft body 23 of the second drive shaft 2 are driven in synchronous rotation by another drive unit 4.

[0040] Therefore, the rotation speeds of the left and right shafts 12 and 13 of the first drive shaft 1 do not have to be the same, and the rotation speeds of the left and right shafts 22 and 23 of the second drive shaft 2 do not have to be the same.

[0041] The driven shaft 6 is made up of a first shaft body 61 and a second shaft body 62 that are arranged coaxially, and adjacent ends of the first shaft body 61 and the second shaft body 62 are provided in a state of being suspended in the air.

[0042] One lot of wafers 5 is placed between the first locking groove 11 of the left shaft body 12 of the first drive shaft 1 and the second locking groove 21 of the left shaft body 22 of the second drive shaft 2, and at the same time, is rotated and cleaned in conjunction with the positioning groove 63 on the first shaft body 61.

[0043] Wafers 5 from another lot are placed between the first locking groove 11 of the right shaft body 13 of the first drive shaft 1 and the second locking groove 21 of the right shaft body 23 of the second drive shaft 2, and simultaneously rotated and cleaned in conjunction with the positioning groove 63 on the second shaft body 62.

[0044] Therefore, the two lots of wafers 5 are rotated and driven by different driving units 4 to be cleaned, and the rotation cleaning speeds may be different, forming relatively independent cleaning rhythms and meeting different cleaning requirements.

[0045] Of course, the first drive shaft 1 is divided into a left shaft 12 and a right shaft 13, the second drive shaft 2 is divided into a left shaft 22 and a right shaft 23, and the driven shaft 6 is divided into a first shaft 61 and a second shaft 62, but these three features can be arbitrarily combined with the nine features in embodiment 1 and are not limited thereto.

[0046] The above specific embodiments are intended to explain and explain the present invention, but are not intended to limit the present invention. Any modifications or changes made to the present invention within the spirit and scope of the claims are also included in the scope of the present invention.

Claims

1. An array type megasonic cleaning apparatus for cleaning wafers, comprising: a cleaning tank (3) having a cleaning liquid and a megasonic generator (31) therein; and a first main drive shaft (1) and a second main drive shaft (2) arranged parallel to each other within the cleaning tank (3) and rotatable around their own centerlines by being driven by a drive unit (4). The first main drive shaft (1) and the second main drive shaft (2) have a length of 60 mm to 350 mm, The first drive shaft (1) is provided with at least two first locking grooves (11) along its length, and the second drive shaft (2) is provided with at least two second locking grooves (21) along its length, the second locking grooves (21) being provided corresponding to the first locking grooves (11); A plurality of wafers (5) can be placed by the cooperation of the first locking groove (11) and the second locking groove (21), and the first drive shaft (1) and the second drive shaft (2) are configured to be located on both sides of the central axis of the wafers (5), respectively; The first drive shaft (1) and the second drive shaft (2) rotate in the same direction, and can simultaneously rotate and frictionally drive a plurality of wafers (5) to achieve cleaning.

1. An array type megasonic cleaning apparatus for cleaning wafers, comprising:

2. The wafer further includes a driven shaft (6) having at least two positioning grooves (63), the positioning grooves (63), the first locking grooves (11), and the second locking grooves (21) being located in the same vertical plane, and the edge of the wafer (5) falls into the positioning grooves (63).

2. The array type megasonic cleaning apparatus for cleaning wafers according to claim 1.

3. The driven shaft (6) is configured to be located below the wafer (5) and to be offset from the central axis of the wafer (5).

3. The array type megasonic cleaning apparatus for cleaning wafers according to claim 2.

4. A gap is formed between the inner wall of the positioning groove (63) and the wafer (5).

3. The array type megasonic cleaning apparatus for cleaning wafers according to claim 2.

5. The side surface of the positioning groove (63) contacts the wafer (5) to rotate the driven shaft (6), the driven shaft (6) is circumferentially in contact with a rotation speed detection unit (64) to monitor the rotation speed of the wafer (5), and there is a gap between the bottom surface of the positioning groove (63) and the wafer (5).

3. The array type megasonic cleaning apparatus for cleaning wafers according to claim 2.

6. The rotation speeds of the first main driving shaft (1) and the second main driving shaft (2) are the same.

2. The array type megasonic cleaning apparatus for cleaning wafers according to claim 1.

7. One end of the first drive shaft (1) and / or the second drive shaft (2) is connected to the side wall of the cleaning tank (3), and the other end is connected to the drive unit (4), or one end of the first drive shaft (1) and / or the second drive shaft (2) is provided in a suspended state within the cleaning tank (3), and the other end is connected to the drive unit (4).

2. The array type megasonic cleaning apparatus for cleaning wafers according to claim 1.

8. The driven shaft (6) includes a first shaft body (61) and a second shaft body (62), the first shaft body (61) and the second shaft body (62) are provided coaxially, and adjacent ends of the first shaft body (61) and the second shaft body (62) are provided in a suspended state.

3. The array type megasonic cleaning apparatus for cleaning wafers according to claim 2.

9. The first drive shaft (1) and / or the second drive shaft (2) include a left shaft body and a right shaft body that are coaxially arranged and rotated and driven by the drive unit (4), respectively.

2. The array type megasonic cleaning apparatus for cleaning wafers according to claim 1.

10. The left and right shafts have different rotation speeds.

10. The array megasonic cleaning apparatus for cleaning wafers according to claim 9.

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