Wafer cleaning method and cleaning device

Abstract

To provide a cleaning method that can achieve highly reproducible cleaning efficiency by forcibly controlling the shape of a wafer using a roll cleaning element.SOLUTION: A scrubbing cleaning operation of a wafer W includes a standard cleaning operation in which the wafer W is scrubbed with a first roll cleaning member 7 and a second roll cleaning member 8 located at the standard cleaning position, a first offset cleaning operation in which the wafer W is scrubbed with the first roll cleaning member 7 and the second roll cleaning member 8 located at a first offset cleaning position shifted from the standard cleaning position in the direction toward the first roll cleaning member 7, and a second offset cleaning operation in which the wafer W is scrubbed with the first roll cleaning member 7 and the second roll cleaning member 8 located at a second offset cleaning position shifted from the standard cleaning position in the direction toward the second roll cleaning member 8.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a wafer cleaning method and cleaning apparatus, and more particularly to a cleaning method and cleaning apparatus for scrubbing both surfaces of a wafer having a laminated wiring structure. [Background technology]

[0002] In recent years, as semiconductor devices have become more highly integrated, circuit wiring has become finer and the distance between wiring has become narrower. In the manufacture of semiconductor devices, many types of materials are repeatedly deposited in film form on silicon wafers to form a layered structure. In order to form this layered structure, technology for flattening the wafer surface is important. As one method for flattening such wafer surfaces, polishing equipment (also known as chemical mechanical polishing equipment) that performs chemical mechanical polishing (CMP) is widely used.

[0003] This chemical mechanical polishing (CMP) apparatus generally includes a polishing table with a polishing pad attached, a polishing head that holds the wafer, and a nozzle that supplies a polishing liquid (slurry) onto the polishing pad. While the polishing liquid is being supplied onto the polishing pad from the nozzle, the polishing head presses the wafer against the polishing pad, and the polishing head and polishing table are moved relative to each other to polish the wafer.

[0004] After CMP, polishing fluid and polishing products remain on the front, back, and side (bevel) of the wafer. In the semiconductor wafer manufacturing process, the cleanliness of the device-forming surface is important. Therefore, polished wafers are transported from the polishing device to a cleaning device, where they are cleaned. The cleaning device supplies cleaning fluid to both sides of the wafer while scrubbing both sides of the wafer with a roll cleaning member. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2023-45821 Summary of the Invention [Problem to be solved by the invention]

[0006] In recent years, with the advancement of multilayer and three-dimensional wafers, the phenomenon of wafer warping has been reported. When a wafer is warped, the roll cleaning element cannot properly contact the wafer surface, resulting in the inability to efficiently remove deposits from the wafer. Depending on the type of wafer and the wafer manufacturing process, wafers can be warped in either a convex or concave shape. Current cleaning equipment cleans wafers with different warpage shapes according to the same cleaning recipe, making it difficult to ensure cleaning efficiency for all wafers with different degrees of warpage.

[0007] An object of the present invention is to provide a cleaning method and cleaning apparatus that can achieve highly reproducible cleaning efficiency by forcibly controlling the shape of a wafer using a roll cleaning member, regardless of the shape of the wafer. [Means for solving the problem]

[0008] In one aspect, a cleaning method for cleaning a wafer is provided, which includes performing a scrubbing cleaning operation to scrub a first side and a second side of the wafer with a first roll cleaning member and a second roll cleaning member while rotating the wafer around a central axis using a plurality of holding rollers that contact a peripheral portion of the wafer, the scrubbing cleaning operation including: a reference cleaning operation to scrub the first side and the second side of the wafer with the first roll cleaning member and the second roll cleaning member at a reference cleaning position; a first offset cleaning operation to scrub the first side and the second side of the wafer with the first roll cleaning member and the second roll cleaning member at a first offset cleaning position that is shifted from the reference cleaning position in a direction toward the first roll cleaning member; and a second offset cleaning operation to scrub the first side and the second side of the wafer with the first roll cleaning member and the second roll cleaning member at a second offset cleaning position that is shifted from the reference cleaning position in a direction toward the second roll cleaning member.

[0009] In one embodiment, the reference cleaning operation, the first offset cleaning operation, and the second offset cleaning operation are performed in a predetermined order. In one embodiment, the scrubbing operation further includes a first intermediate offset cleaning operation in which the first and second roll cleaning members are scrubbed at a first intermediate offset position, the first intermediate offset position being between the reference cleaning position and the first offset cleaning position. In one embodiment, the scrubbing operation further includes a second intermediate offset cleaning operation in which the first and second roll cleaning members are positioned at a second intermediate offset position to scrub the first and second sides of the wafer, the second intermediate offset position being between the reference cleaning position and the second offset cleaning position.

[0010] In one aspect, a cleaning apparatus for cleaning a wafer includes a plurality of rotatable holding rollers that contact a peripheral portion of the wafer and rotate the wafer about a central axis, a first roll cleaning member and a second roll cleaning member that scrub a first side and a second side of the wafer, a first actuator connected to the first roll cleaning member and moving the first roll cleaning member, a second actuator connected to the second roll cleaning member and moving the second roll cleaning member, and an operation controller that controls operation of the first actuator and the second actuator, wherein the operation controller issues commands to the first actuator and the second actuator to move the first roll cleaning member and the second roll cleaning member to a reference cleaning position, a first offset cleaning position, and a second offset cleaning position. the cleaning apparatus is configured to perform scrub cleaning operations including a combination of a reference cleaning operation in which the first and second sides of the wafer are scrubbed with the first and second roll cleaning members at the reference cleaning position, a first offset cleaning operation in which the first and second sides of the wafer are scrubbed with the first and second roll cleaning members at the first offset cleaning position shifted from the reference cleaning position in a direction toward the first roll cleaning member, and a second offset cleaning operation in which the first and second sides of the wafer are scrubbed with the first and second roll cleaning members at the second offset cleaning position shifted from the reference cleaning position in a direction toward the second roll cleaning member.

[0011] In one embodiment, the operation control unit is configured to issue commands to the first actuator and the second actuator to move the first roll cleaning member and the second roll cleaning member to the reference cleaning position, the first offset cleaning position, and the second offset cleaning position in a predetermined order. In one aspect, the operation control unit is configured to issue a command to the first actuator and the second actuator to move the first roll cleaning member and the second roll cleaning member to a first intermediate offset position that is between the reference cleaning position and the first offset cleaning position, and the cleaning device is further configured to perform a first intermediate offset cleaning operation that scrubs the first surface and the second surface of the wafer with the first roll cleaning member and the second roll cleaning member that are at the first intermediate offset position. In one aspect, the operation control unit is configured to issue a command to the first actuator and the second actuator to move the first roll cleaning member and the second roll cleaning member to a second intermediate offset position between the reference cleaning position and the second offset cleaning position, and the cleaning device is configured to further perform a second intermediate offset cleaning operation to scrub the first surface and the second surface of the wafer with the first roll cleaning member and the second roll cleaning member at the second intermediate offset position. [Effects of the Invention]

[0012] The first and second roll cleaning members move between the reference cleaning position, the first offset cleaning position, and the second offset cleaning position to forcibly deform the wafer in a first direction and a second direction symmetrical with respect to the reference cleaning position during wafer cleaning. The pressure distribution applied to the wafer by the first and second roll cleaning members changes during wafer cleaning. As a result, wafers of any shape can be cleaned with the same cleaning efficiency. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a perspective view illustrating an embodiment of a cleaning apparatus for cleaning wafers. [Figure 2] 2 is a diagram showing an embodiment of a detailed configuration of the cleaning device shown in FIG. 1. FIG. [Figure 3] 10A to 10C are diagrams illustrating an operation of cleaning a wafer. [Figure 4] 10A and 10B are diagrams illustrating the reference cleaning positions of the first roll cleaning member and the second roll cleaning member. [Figure 5] 10A and 10B are diagrams illustrating first offset cleaning positions of the first roll cleaning member and the second roll cleaning member. [Figure 6] 10A and 10B are diagrams illustrating second offset cleaning positions of the first roll cleaning member and the second roll cleaning member. [Figure 7] 1A and 1B are schematic diagrams illustrating an embodiment of a scrubbing operation for cleaning a flat wafer. [Figure 8] 10A and 10B are schematic diagrams illustrating an embodiment of a scrubbing operation for cleaning a wafer having a convex first surface. [Figure 9] 1A and 1B are schematic diagrams illustrating an embodiment of a scrubbing operation for cleaning a wafer having a concave first surface. [Figure 10] 10 is a diagram showing the distribution of pressure applied to a wafer from a first roll cleaning member and a second roll cleaning member during a first offset cleaning operation. FIG. [Figure 11] 10 is a diagram showing the distribution of pressure applied to a wafer from a first roll cleaning member and a second roll cleaning member during a second offset cleaning operation. FIG. [Figure 12] FIG. 10 illustrates one embodiment of a first intermediate offset position between the reference cleaning position and the first offset cleaning position. [Figure 13] FIG. 10 illustrates one embodiment of a second intermediate offset position between the reference cleaning position and the second offset cleaning position. [Figure 14] FIG. 10 is a perspective view showing another embodiment of the cleaning device. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Fig. 1 is a perspective view showing one embodiment of a cleaning apparatus for cleaning wafers. As shown in Fig. 1, the cleaning apparatus includes a plurality of rotatable holding rollers 5 that contact the peripheral portion of the wafer W and rotate the wafer W about a central axis CL, and a first roll cleaning member 7 and a second roll cleaning member 8 that scrub the first surface 1a and the second surface 1b of the wafer W.

[0015] The first surface 1a and the second surface 1b of the wafer W are circular surfaces. The first surface 1a of the wafer W is, for example, a device surface on which devices are formed or will be formed. The second surface 1b of the wafer W is, for example, a non-device surface on which devices are not formed or will not be formed. The second surface 1b is located on the opposite side to the first surface 1a.

[0016] The multiple holding rollers 5 are arranged around the central axis CL. When holding a wafer W, the multiple holding rollers 5 are all the same distance from the central axis CL. The center of the wafer W held by the multiple holding rollers 5 is on the central axis CL. In this embodiment, four holding rollers 5 are arranged, but five or more holding rollers 5 may be arranged. The multiple holding rollers 5 are connected to a roller rotation device (not shown) and, as shown in FIG. 1, are rotated in the same direction at the same rotational speed by the roller rotation device. Each holding roller 5 has a wafer holding groove 5a formed on its outer circumferential surface. The wafer holding groove 5a is an annular groove extending circumferentially on the outer circumferential surface of each holding roller 5. The width of the wafer holding groove 5a is greater than the thickness of the wafer W, and the peripheral edge of the wafer W contacts the multiple wafer holding grooves 5a of the multiple holding rollers 5. These wafer holding grooves 5a stabilize the posture of the rotating wafer W.

[0017] The first roll cleaning member 7 and the second roll cleaning member 8 each have a cylindrical shape. The first roll cleaning member 7 and the second roll cleaning member 8 are connected to a first rotation device and a second rotation device, respectively, which rotate the first roll cleaning member 7 and the second roll cleaning member 8 around their own axes. The first roll cleaning member 7 and the second roll cleaning member 8 are each made of an elastic material such as a sponge. The first roll cleaning member 7 and the second roll cleaning member 8 come into sliding contact with the first surface 1a and the second surface 1b of the wafer W while rotating, thereby scrubbing and cleaning the first surface 1a and the second surface 1b.

[0018] During cleaning of the wafer W, the first roll cleaning member 7 contacts the center of the first surface 1a of the wafer W, and the second roll cleaning member 8 contacts the center of the second surface 1b of the wafer W. In one embodiment, the central axis R1 of the first roll cleaning member 7 passes through the central axis line CL, and the central axis R2 of the second roll cleaning member 8 also passes through the central axis line CL. The axial lengths of the first roll cleaning member 7 and the second roll cleaning member 8 are equal to or greater than the diameter of the wafer W. In one embodiment, as shown in FIG. 1 , both ends of the first roll cleaning member 7 and the second roll cleaning member 8 extend beyond the wafer W. The first roll cleaning member 7 and the second roll cleaning member 8 can contact the entire first surface 1a and the entire second surface 1b of the wafer W.

[0019] The cleaning device includes a first cleaning liquid nozzle 11 adjacent to the first roll cleaning member 7 and a second cleaning liquid nozzle 12 adjacent to the second roll cleaning member 8. The first cleaning liquid nozzle 11 supplies cleaning liquid to a first surface 1a of the wafer W held and rotated by a plurality of holding rollers 5, and the second cleaning liquid nozzle 12 supplies cleaning liquid to a second surface 1b of the wafer W held and rotated by a plurality of holding rollers 5. The first roll cleaning member 7 and the second roll cleaning member 8 scrub and clean the first surface 1a and the second surface 1b of the wafer W in the presence of the cleaning liquid. Examples of cleaning liquids include chemical solutions, pure water, and combinations thereof.

[0020] Figure 2 is a diagram showing one embodiment of the detailed configuration of the cleaning device shown in Figure 1. As shown in Figure 2, the cleaning device includes a first rotation device 15 that rotates the first roll cleaning member 7 about its axis, a second rotation device 16 that rotates the second roll cleaning member 8 about its axis, a first actuator 21 that moves the first roll cleaning member 7, a second actuator 22 that moves the second roll cleaning member 8, a first support base 25 that rotatably supports the first roll cleaning member 7, and a second support base 26 that rotatably supports the second roll cleaning member 8.

[0021] The first rotation device 15 is fixed to a first support table 25, and the second rotation device 16 is fixed to a second support table 26. The first rotation device 15 is connected to the first roll cleaning member 7 via a first rotation shaft 31, and the second rotation device 16 is connected to the second roll cleaning member 8 via a second rotation shaft 32. The specific configurations of the first rotation device 15 and the second rotation device 16 are not particularly limited, but examples include an electric motor or a combination of an electric motor and a torque transmission mechanism (e.g., a belt or gears).

[0022] The first actuator 21 is connected to the first roll cleaning member 7 via a first support base 25, and the second actuator 22 is connected to the second roll cleaning member 8 via a second support base 26. More specifically, the first actuator 21 is connected to the first support base 25 that rotatably supports the first roll cleaning member 7, and the second actuator 22 is connected to the second support base 26 that rotatably supports the second roll cleaning member 8.

[0023] 2, the first actuator 21 moves the first roll cleaning member 7, the first support base 25, and the first rotation device 15 together in a direction toward and away from the first surface 1a of the wafer W. The second actuator 22 moves the second roll cleaning member 8, the second support base 26, and the second rotation device 16 together in a direction toward and away from the second surface 1b of the wafer W.

[0024] The specific configuration of the first actuator 21 and the second actuator 22 is not particularly limited, but examples thereof include a combination of an air cylinder and a pressure regulator, and a combination of a ball screw mechanism and a servo motor.

[0025] The cleaning device includes an operation control unit 40 that controls the operations of the roller rotation device (not shown), first rotation device 15, second rotation device 16, first actuator 21, and second actuator 22. The roller rotation device (not shown), first rotation device 15, second rotation device 16, first actuator 21, and second actuator 22 are electrically connected to the operation control unit 40.

[0026] The operation control unit 40 includes a storage device 40a that stores a program, and an arithmetic unit 40b that executes calculations according to instructions included in the program. The operation control unit 40 is composed of at least one computer. The storage device 40a includes a main storage device such as a random access memory (RAM), and an auxiliary storage device such as a hard disk drive (HDD) or a solid state drive (SSD). Examples of the arithmetic unit 40b include a CPU (central processing unit) and a GPU (graphics processing unit). However, the specific configuration of the operation control unit 40 is not limited to these examples.

[0027] The wafer W is cleaned as follows. The wafer W is held by a plurality of holding rollers 5. Then, while a cleaning liquid is supplied from a first cleaning liquid nozzle 11 and a second cleaning liquid nozzle 12 to the first surface 1a and the second surface 1b of the wafer W, the wafer W is rotated by the plurality of holding rollers 5, and the first rotation device 15 and the second rotation device 16 rotate the first roll cleaning member 7 and the second roll cleaning member 8. When the rotation speed of the wafer W reaches a predetermined rotation speed, the first actuator 21 and the second actuator 22 bring the first roll cleaning member 7 and the second roll cleaning member 8 into contact with the first surface 1a and the second surface 1b of the rotating wafer W, as shown in FIG. 3 . The rotating first roll cleaning member 7 and the second roll cleaning member 8 come into sliding contact with the first surface 1a and the second surface 1b of the wafer W in the presence of the cleaning liquid, thereby scrubbing and cleaning the first surface 1a and the second surface 1b.

[0028] The operation control unit 40 is configured to issue commands to the first actuator 21 and the second actuator 22 to move the first roll cleaning member 7 and the second roll cleaning member 8 to the reference cleaning position, the first offset cleaning position, and the second offset cleaning position in a predetermined order while cleaning the wafer W.

[0029] FIG. 4 is a diagram illustrating the reference cleaning position of the first roll cleaning member 7 and the second roll cleaning member 8. The reference cleaning position is a position where the center point CP of the wafer W is located within a plane (an imaginary plane) ST that passes through the multiple wafer holding grooves 5a of the multiple holding rollers 5. When the wafer W is sandwiched between the first roll cleaning member 7 and the second roll cleaning member 8 at the reference cleaning position, the wafer W is held in a flat shape, as shown in FIG. 4. In this specification, scrubbing the wafer W with the first roll cleaning member 7 and the second roll cleaning member 8 at the reference cleaning position is defined as the reference cleaning operation.

[0030] FIG. 5 illustrates the first offset cleaning position of the first roll cleaning member 7 and the second roll cleaning member 8. The first offset cleaning position is a position shifted from the reference cleaning position shown in FIG. 4 toward the first roll cleaning member 7. The center point CP of the wafer W is away from the plane ST and is located between the first roll cleaning member 7 and the plane ST. When the wafer W is sandwiched between the first roll cleaning member 7 and the second roll cleaning member 8 at the first offset cleaning position, as shown in FIG. 5, the first surface 1a of the wafer W is held in a convex shape, and the second surface 1b of the wafer W is held in a concave shape. In this specification, scrubbing of the wafer W by the first roll cleaning member 7 and the second roll cleaning member 8 at the first offset cleaning position is defined as the first offset cleaning operation.

[0031] FIG. 6 illustrates the second offset cleaning position of the first roll cleaning member 7 and the second roll cleaning member 8. The second offset cleaning position is a position shifted from the reference cleaning position shown in FIG. 4 toward the second roll cleaning member 8. The center point CP of the wafer W is away from the plane ST and is located between the second roll cleaning member 8 and the plane ST. When the wafer W is sandwiched between the first roll cleaning member 7 and the second roll cleaning member 8 at the second offset cleaning position, as shown in FIG. 6, the first surface 1a of the wafer W is held in a concave shape, and the second surface 1b of the wafer W is held in a convex shape. In this specification, scrubbing of the wafer W by the first roll cleaning member 7 and the second roll cleaning member 8 at the second offset cleaning position is defined as the second offset cleaning operation.

[0032] The cleaning apparatus is configured to perform a scrubbing cleaning operation that includes a combination of a reference cleaning operation, a first offset cleaning operation, and a second offset cleaning operation.

[0033] An embodiment of the scrub cleaning operation of the cleaning apparatus will be described in detail below. Fig. 7 is a schematic diagram showing an embodiment of the scrub cleaning operation for cleaning a flat wafer W. In this embodiment, the scrub cleaning operation of the wafer W is performed in the order of a first offset cleaning operation, a reference cleaning operation, and a second offset cleaning operation. In this embodiment, the first offset cleaning operation, the reference cleaning operation, and the second offset cleaning operation are performed for the same period of time.

[0034] 8 is a schematic diagram showing one embodiment of a scrub cleaning operation for cleaning a wafer W whose first surface 1a is convex, and FIG. 9 is a schematic diagram showing one embodiment of a scrub cleaning operation for cleaning a wafer W whose first surface 1a is concave. In these embodiments, the scrub cleaning operation of the wafer W is performed in the order of a first offset cleaning operation, a reference cleaning operation, and a second offset cleaning operation. In one embodiment, the first offset cleaning operation, the reference cleaning operation, and the second offset cleaning operation are performed for the same amount of time.

[0035] 10 is a diagram showing the distribution of pressures applied to the wafer W from the first roll cleaning member 7 and the second roll cleaning member 8 during the first offset cleaning operation. As shown in Fig. 10, the pressure PC1 applied from the first roll cleaning member 7 to the center of the first surface 1a of the wafer W is greater than the pressure PE1 applied from the first roll cleaning member 7 to the edge portion of the first surface 1a of the wafer W. On the other hand, the pressure PC2 applied from the second roll cleaning member 8 to the center of the second surface 1b of the wafer W is smaller than the pressure PE2 applied from the second roll cleaning member 8 to the edge portion of the second surface 1b of the wafer W.

[0036] 11 is a diagram showing the distribution of pressures applied to the wafer W from the first roll cleaning member 7 and the second roll cleaning member 8 during the second offset cleaning operation. As shown in Fig. 11, the pressure PC1 applied from the first roll cleaning member 7 to the center of the first surface 1a of the wafer W is smaller than the pressure PE1 applied from the first roll cleaning member 7 to the edge portion of the first surface 1a of the wafer W. On the other hand, the pressure PC2 applied from the second roll cleaning member 8 to the center of the second surface 1b of the wafer W is larger than the pressure PE2 applied from the second roll cleaning member 8 to the edge portion of the second surface 1b of the wafer W.

[0037] As can be seen from FIGS. 10 and 11 , the pressure distributions applied to the wafer W from the first roll cleaning member 7 and the second roll cleaning member 8 differ between the first offset cleaning operation and the second offset cleaning operation. Such differences in pressure distributions also occur for wafers W with different shapes, as shown in FIGS. 7 to 9 . By generating such differences in pressure distributions during the scrubbing cleaning operation of the wafer W, the cleaning apparatus can clean wafers W of any shape with the same cleaning efficiency (improving cleaning reproducibility). That is, whether the first surface 1 a of the wafer W is convex, the second surface 1 b of the wafer W is convex, or the wafer W has a wavy shape, the cleaning apparatus can clean the wafer W with different pressure distributions as shown in FIGS. 10 and 11 . As a result, non-uniform cleaning due to the shape of the wafer W can be reduced.

[0038] The order of the first offset cleaning operation, the reference cleaning operation, and the second offset cleaning operation is not limited to the above-described embodiment. Examples of the order of the first offset cleaning operation, the reference cleaning operation, and the second offset cleaning operation include the following. First offset cleaning operation → Standard cleaning operation → Second offset cleaning operation Second offset cleaning operation → Standard cleaning operation → First offset cleaning operation Standard cleaning operation → 1st offset cleaning operation → 2nd offset cleaning operation Standard cleaning operation → Second offset cleaning operation → First offset cleaning operation First offset cleaning operation → Second offset cleaning operation → Standard cleaning operation Second offset cleaning operation → First offset cleaning operation → Standard cleaning operation

[0039] 12 , the operation control unit 40 is configured to issue a command to the first actuator 21 and the second actuator 22 to move the first roll cleaning member 7 and the second roll cleaning member 8 to a first intermediate offset position between the reference cleaning position and the first offset cleaning position. The cleaning apparatus is further configured to perform a first intermediate offset cleaning operation in which the first surface 1 a and the second surface 1 b of the wafer W are scrubbed with the first roll cleaning member 7 and the second roll cleaning member 8 at the first intermediate offset position. In this specification, the scrubbing of the wafer W with the first roll cleaning member 7 and the second roll cleaning member 8 at the first intermediate offset cleaning position is defined as the first intermediate offset cleaning operation.

[0040] In one embodiment, the first intermediate offset cleaning operation is performed for the same time as the reference cleaning operation, the first offset cleaning operation, and the second offset cleaning operation. The first intermediate offset cleaning operation can create a pressure distribution different from that of the first offset cleaning operation. In particular, the first intermediate offset cleaning operation can increase the pressure in the intermediate portion between the center and edge of the first surface 1 a of the wafer W. As a result, the cleaning apparatus can clean wafers W of various shapes with the same cleaning efficiency.

[0041] The order of the reference cleaning operation, the first offset cleaning operation, the first intermediate offset cleaning operation, and the second offset cleaning operation is not particularly limited. For example, the first intermediate offset cleaning operation may be performed before the first offset cleaning operation or after the first offset cleaning operation.

[0042] 13 , the operation control unit 40 is configured to issue a command to the first actuator 21 and the second actuator 22 to move the first roll cleaning member 7 and the second roll cleaning member 8 to a second intermediate offset position between the reference cleaning position and the second offset cleaning position. The cleaning apparatus is further configured to perform a second intermediate offset cleaning operation in which the first roll cleaning member 7 and the second roll cleaning member 8 at the second intermediate offset position scrub the first surface 1 a and the second surface 1 b of the wafer W. In this specification, the scrubbing of the wafer W at the first roll cleaning member 7 and the second roll cleaning member 8 at the second intermediate offset cleaning position is defined as the second intermediate offset cleaning operation.

[0043] In one embodiment, the second intermediate offset cleaning operation is performed for the same time as the reference cleaning operation, the first offset cleaning operation, and the second offset cleaning operation. The second intermediate offset cleaning operation can create a pressure distribution different from that of the second offset cleaning operation. In particular, the second intermediate offset cleaning operation can increase the pressure in the middle portion between the center and edge portions of the second surface 1b of the wafer W. As a result, the cleaning apparatus can clean wafers W of various shapes with the same cleaning efficiency.

[0044] The order of the reference cleaning operation, the first offset cleaning operation, the second intermediate offset cleaning operation, and the second offset cleaning operation is not particularly limited. For example, the second intermediate offset cleaning operation may be performed before the second offset cleaning operation or after the second offset cleaning operation.

[0045] In one embodiment, the cleaning apparatus is configured to perform a scrub cleaning operation including a combination of a reference cleaning operation, a first offset cleaning operation, a first intermediate offset cleaning operation, a second offset cleaning operation, and a second intermediate offset cleaning operation. The order of the reference cleaning operation, the first offset cleaning operation, the first intermediate offset cleaning operation, the second offset cleaning operation, and the second intermediate offset cleaning operation is not particularly limited. An example of the order is described below, but the order of the scrub cleaning operation is not limited to the example. First offset cleaning operation → First intermediate offset cleaning operation → Standard cleaning operation → Second intermediate offset cleaning operation → Second offset cleaning operation Second offset cleaning operation → Second intermediate offset cleaning operation → Standard cleaning operation → First intermediate offset cleaning operation → First offset cleaning operation Standard cleaning operation → 1st offset cleaning operation → 1st intermediate offset cleaning operation → 2nd intermediate offset cleaning operation → 2nd offset cleaning operation Standard cleaning operation → Second offset cleaning operation → Second intermediate offset cleaning operation → First intermediate offset cleaning operation → First offset cleaning operation First intermediate offset cleaning operation → First offset cleaning operation → Second offset cleaning operation → Second intermediate offset cleaning operation → Standard cleaning operation Second intermediate offset cleaning operation → Second offset cleaning operation → First offset cleaning operation → First intermediate offset cleaning operation → Standard cleaning operation

[0046] 1 to 13, the wafer W is cleaned in a horizontal position. In one embodiment, the cleaning apparatus may be configured to clean the wafer W in a vertical position, as shown in Fig. 14. In another embodiment, although not shown, the wafer W may be cleaned in an oblique position.

[0047] The above-described embodiments have been described for the purpose of enabling a person of ordinary skill in the art to practice the present invention. Various modifications of the above-described embodiments would be obvious to a person skilled in the art, and the technical concept of the present invention may be applied to other embodiments. Therefore, the present invention is not limited to the described embodiments, but is to be interpreted in the broadest scope in accordance with the technical concept defined by the claims. [Explanation of symbols]

[0048] W wafer 1a 1st page 1b 2nd side 5 Retaining Roller 7 First roll cleaning member 8 Second roll cleaning member 11 First cleaning solution nozzle 12 Second cleaning solution nozzle 15 First Rotating Device 16 Second Rotating Device 21 First actuator 22 Second actuator 25 1st support stand 26 Second support stand 31 First rotation axis 32 Second rotation axis 40 Motion control section

Claims

1. A cleaning method for cleaning a wafer, comprising: performing a scrubbing cleaning operation in which the first surface and the second surface of the wafer are scrubbed with a first roll cleaning member and a second roll cleaning member while rotating the wafer about a central axis line by a plurality of holding rollers that contact a peripheral edge portion of the wafer; The scrubbing action includes: a reference cleaning operation in which the first surface and the second surface of the wafer are scrubbed with the first roll cleaning member and the second roll cleaning member located at a reference cleaning position; a first offset cleaning operation in which the first surface and the second surface of the wafer are scrubbed with the first roll cleaning member and the second roll cleaning member located at a first offset cleaning position shifted from the reference cleaning position in a direction toward the first roll cleaning member; a second offset cleaning operation in which the first and second surfaces of the wafer are scrubbed with the first and second roll cleaning members located at a second offset cleaning position that is shifted from the reference cleaning position in a direction toward the second roll cleaning member.

2. The cleaning method according to claim 1 , wherein the reference cleaning operation, the first offset cleaning operation, and the second offset cleaning operation are performed in a predetermined order.

3. the scrubbing operation further includes a first intermediate offset cleaning operation in which the first and second roll cleaning members are positioned at a first intermediate offset position to scrub the first and second surfaces of the wafer; The cleaning method of claim 1 , wherein the first intermediate offset position is between the reference cleaning position and the first offset cleaning position.

4. the scrubbing operation further includes a second intermediate offset cleaning operation in which the first and second roll cleaning members are positioned at a second intermediate offset position to scrub the first and second surfaces of the wafer; The cleaning method of claim 1 , wherein the second intermediate offset position is between the reference cleaning position and the second offset cleaning position.

5. A cleaning apparatus for cleaning wafers, a plurality of rotatable holding rollers that contact the peripheral edge of the wafer and rotate the wafer about a central axis; a first roll cleaning member and a second roll cleaning member for scrubbing the first and second surfaces of the wafer; a first actuator connected to the first roll cleaning member and configured to move the first roll cleaning member; a second actuator connected to the second roll cleaning member and configured to move the second roll cleaning member; an operation control unit that controls operations of the first actuator and the second actuator; the operation control unit is configured to issue commands to the first actuator and the second actuator to move the first roll cleaning member and the second roll cleaning member to a reference cleaning position, a first offset cleaning position, and a second offset cleaning position, The cleaning device is a reference cleaning operation in which the first surface and the second surface of the wafer are scrubbed with the first roll cleaning member and the second roll cleaning member located at the reference cleaning position; a first offset cleaning operation in which the first surface and the second surface of the wafer are scrubbed with the first roll cleaning member and the second roll cleaning member located at the first offset cleaning position shifted from the reference cleaning position in a direction toward the first roll cleaning member; a cleaning apparatus configured to perform a scrub cleaning operation including a combination of a second offset cleaning operation in which the first and second surfaces of the wafer are scrubbed with the first roll cleaning member and the second roll cleaning member located at the second offset cleaning position shifted from the reference cleaning position in a direction toward the second roll cleaning member.

6. 6. The cleaning device according to claim 5, wherein the operation control unit is configured to issue commands to the first actuator and the second actuator to move the first roll cleaning member and the second roll cleaning member to the reference cleaning position, the first offset cleaning position, and the second offset cleaning position in a predetermined order.

7. the operation control unit is configured to issue a command to the first actuator and the second actuator to move the first roll cleaning member and the second roll cleaning member to a first intermediate offset position between the reference cleaning position and the first offset cleaning position, 6. The cleaning apparatus of claim 5, further configured to perform a first intermediate offset cleaning operation in which the first and second roll cleaning members are positioned at the first intermediate offset position to scrub the first and second surfaces of the wafer.

8. the operation control unit is configured to issue a command to the first actuator and the second actuator to move the first roll cleaning member and the second roll cleaning member to a second intermediate offset position between the reference cleaning position and the second offset cleaning position, 6. The cleaning apparatus of claim 5, further comprising a second intermediate offset cleaning operation for scrubbing the first and second surfaces of the wafer with the first and second roll cleaning members at the second intermediate offset position.

Images