Chuck device

Abstract

To provide a chuck device that can efficiently form an ultrathin water film for appropriately holding a work-piece, with high accuracy, and easily peel work-pieces joined with the water film.SOLUTION: A chuck table comprises a chuck 10 for holding a work-piece 30 in a substrate shape through a water film 20. The chuck is formed of a porous structure, and a flat surface 13 opposing to the work-piece is formed on a surface 11 for holding the work-piece, of the chuck. This enables the porous structure to absorb excess water supplied to the surface of the chuck, so that a high-precision ultrathin water film that can appropriately hold the work-piece can be formed efficiently. This can apply even loads to a whole surface of the work-piece, while preventing a particulate matter 12 of the porous structure from directly contacting the work-piece, and further enables the work-piece to be peeled therefrom, which can achieve high-accuracy and high-efficiency thinning processing and conveyance with a high yield to a work-piece such as a semiconductor substrate.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a chuck device for holding a substrate such as a semiconductor wafer, and particularly to a chuck device for holding a substrate by a water film.

Background Art

[0002] Generally, in a thinning process of grinding or polishing a substrate such as a semiconductor wafer and a transfer process of transferring the substrate, the substrate to be processed is held by vacuum-sucking it onto a porous chuck.

[0003] However, in a chuck device that holds a substrate by vacuum suction, since the substrate is sucked into the pores of the porous chuck, variations occur in the local thickness of the thinned substrate. In addition, sludge such as grinding chips generated by processing is sucked into the vacuum system such as the porous chuck, and there is a risk that the sludge flows back and contaminates the porous chuck when the substrate is released. Then, in subsequent processing, sludge remains between the porous chuck and the substrate, and dimples are generated on the holding surface of the substrate due to the sludge, which becomes a factor in reducing the processing accuracy. Also, in the transfer hand, the adhesion of sludge as described above becomes a factor in generating cracks in the thinned substrate and reducing the yield. In addition, in order to hold the substrate by vacuum suction, a vacuum device for evacuating the porous chuck is required. Further, a chuck device that holds a substrate by vacuum suction also has a problem that it is difficult to hold a substrate having an excessive warp.

[0004] Therefore, the inventors of the present invention have proposed a method for grinding a semiconductor substrate by bonding a template substrate chuck and a semiconductor substrate with a water film, as disclosed in Patent Document 1. Specifically, Patent Document 1 discloses a semiconductor substrate planarization method comprising the steps of: forming a water film on the surface of a template substrate chuck by spin coating; forming a laminate by bonding the template substrate chuck and a semiconductor substrate with a water film; rotating the laminate to reduce the thickness of the water film; grinding the back surface of the semiconductor substrate of the laminate; and separating the planarized semiconductor substrate from the template substrate chuck.

[0005] Furthermore, the present inventors have proposed a method for easily separating a substrate held in a chuck device by a water film from the chuck after thinning. Specifically, Patent Document 2 discloses a separation device that reduces the holding force of a water film so that a workpiece such as a semiconductor substrate or its support, bonded to a chuck by a water film, can be easily peeled off from the flat surface of the chuck.

[0006] For example, the document discloses, as separation devices, a heating device that heats and evaporates a water film by irradiating it with microwaves, a heating device having an infrared heater that irradiates a water film with infrared rays, and a heating device having a heating element formed by a resistance heating type electric heater, etc. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2015-216281 [Patent Document 2] Japanese Patent Publication No. 2018-183848 [Overview of the project] [Problems that the invention aims to solve]

[0008] However, as disclosed in Patent Documents 1 and 2, chuck devices that hold workpieces such as semiconductor substrates using a water film had areas that needed improvement in order to facilitate the holding and separation of workpieces and increase the productivity of semiconductor substrates and the like.

[0009] Specifically, conventional chuck devices that utilize a water film have difficulty removing the water needed to form an extremely thin water film suitable for holding workpieces, and the process of forming a water film of the appropriate thickness is time-consuming.

[0010] In other words, conventional chuck devices required the chuck to be rotated at high speed to remove excess water after water was supplied to the chuck surface in order to form a water film of a suitable thickness. Furthermore, even after the substrate was placed on the water film, a step of rotating the chuck to remove excess water from the water film was applied in order to form a water film that could hold the substrate with a suitable strength due to surface tension.

[0011] Furthermore, Patent Document 2 discloses a configuration that allows for easy removal of a workpiece fixed to a chuck by a water film. However, in order to implement the separation method disclosed in that document, a separation device equipped with a special heating device or the like that reduces the holding power of the water film is required, as described above. Therefore, there has been a need for a technology that can easily reduce the holding power of the water film and easily separate the thinned workpiece without requiring a special separation device or the like.

[0012] The present invention has been made in view of the above circumstances, and its object is to provide a chuck device that can efficiently and accurately form an extremely thin water film that suitably holds a workpiece, and that can easily peel off the workpiece joined by the water film. [Means for solving the problem]

[0013] The chuck device of the present invention is a chuck that holds a substrate-shaped workpiece via a water film. and a water supply device that supplies water to form the water film to the chuck or the workpiece,The chuck is formed from a porous structure, and the surface of the chuck that holds the workpiece has a flat surface facing the workpiece. The water supply device supplies electrolyzed alkaline ionized water as the water that forms the water film. It is characterized by the following: Furthermore, the chuck device of the present invention comprises a chuck that holds a substrate-shaped workpiece via a water film, and a water supply device that supplies water to form the water film to the chuck or the workpiece, wherein the chuck is formed from a porous structure, a flat surface facing the workpiece is formed on the surface of the chuck that holds the workpiece, and the water supply device supplies fine bubble water as the water that forms the water film. Furthermore, the chuck device of the present invention comprises a chuck that holds a substrate-shaped workpiece via a water film, a pressing device that presses the workpiece toward the chuck, and a vibrating device that vibrates the chuck in a direction along the surface of the chuck that holds the workpiece, wherein the chuck is formed from a porous structure, and a flat surface facing the workpiece is formed on its surface, and after water that forms the water film is supplied to the chuck or the workpiece and the workpiece is placed in the chuck, the pressing device presses the workpiece and the vibrating device vibrates the chuck. [Effects of the Invention]

[0014] The chuck device of the present invention has a chuck that holds a substrate-shaped workpiece via a water film, and the chuck is formed from a porous structure. As a result, excess water supplied to the surface of the chuck is absorbed by the porous structure, so that a highly accurate, ultra-thin water film that can suitably hold the workpiece can be efficiently formed. Furthermore, separation of the workpiece and the chuck is also easy by supplying a fluid such as water or air.

[0015] Furthermore, a flat surface is formed on the surface of the chuck that holds the workpiece, facing the workpiece. This eliminates direct contact between the particulate matter constituting the porous structure of the workpiece, such as a semiconductor substrate that is processed to be extremely thin, and applies a uniform load to the entire surface of the workpiece, allowing the workpiece to be held in a highly accurate, flat position. As a result, high-precision and highly efficient substrate processing and transport with a good yield are realized. In particular, regarding transport, there is an advantage in that the equipment can be made lighter because it does not require a vacuum device or the like to adsorb the workpiece.

[0016] Furthermore, according to the chuck device of the present invention, the porous structure is formed from particulate matter with a particle size of 0.5 to 10 μm, and the flat surface is formed with an area ratio of 20 to 50% of the total surface area. As a result, a water film of a suitable thickness for the flat surface can be efficiently formed on the entire surface, the workpiece can be held appropriately in a short time, and high-precision and highly efficient workpiece processing and transport are possible.

[0017] Furthermore, according to the chuck device of the present invention, the flat surface may have a maximum height roughness (Rz) of 0.1 μm or less. This makes it possible to perform high-precision flattening on a workpiece held by the chuck device.

[0018] Furthermore, according to the chuck device of the present invention, the porous structure has a first porous layer constituting the surface and a second porous layer laminated on the back side of the first porous layer, and the particle size of the first porous layer may be smaller than that of the second porous layer. As a result, the second porous layer, which has a large particle size and low water resistance, can support the first porous layer, which has a small particle size and a highly accurate flat surface, and a water film that is highly flattened and suitable for holding can be formed efficiently in a short time. In addition, when removing a workpiece held by the chuck device from the chuck, water that thickens the water film and reduces the holding force can be efficiently supplied from the back side of the second porous layer. Therefore, the workpiece can be peeled off from the chuck efficiently in a short time, and the productivity of semiconductor substrates and the like can be improved.

[0019] Furthermore, the chuck device of the present invention includes a water supply device that supplies water to form the water film to the chuck or the workpiece, and the water supply device may supply electrolyzed alkaline ionized water as the water to form the water film. This makes it possible to efficiently form an extremely thin, highly flattened water film that exhibits suitable holding power.

[0020] Furthermore, the chuck device of the present invention includes a water supply device that supplies water to form the water film to the chuck or the workpiece, and the water supply device may supply fine bubble water as the water to form the water film. This makes it possible to efficiently form an extremely thin, highly flattened water film that exhibits suitable holding power.

[0021] Further, according to the chuck device of the present invention, a water supply device for supplying water for forming the water film to the chuck or the workpiece is provided, and the water supply device may supply water vapor as the water for forming the water film. Thereby, the supply of excessive water is reduced, and a water film that is extremely thin, flattened with high precision, and exhibits a suitable holding force can be efficiently formed.

[0022] Also, according to the chuck device of the present invention, it has a pressing device for pressing the workpiece toward the chuck and a vibrating device for vibrating the chuck in a direction along the surface, and after water for forming the water film is supplied to the chuck or the workpiece and the workpiece is provided on the chuck, the pressing device may press the workpiece and the vibrating device may vibrate the chuck. Thereby, excessive water can be efficiently sent into the gaps of the chuck, and an extremely thin water film that was difficult in the prior art can be formed. Therefore, a water film that is flattened with high precision and exhibits a suitable holding force can be efficiently formed.

[0023] Also, according to the chuck device of the present invention, after the water for forming the water film is supplied to the chuck or the workpiece, the workpiece is provided on the chuck, the water film is formed to have a thickness of 50 to 500 nm, and the workpiece is held by the chuck with a lateral restraint force of 10 kPa or more. Thereby, a water film that is extremely thin, flattened with high precision, and exhibits a suitable holding force can be efficiently formed. Therefore, workpieces such as semiconductor substrates can be processed and transported with high precision, high yield, and high efficiency, and the productivity of semiconductor substrates and the like can be improved.

Brief Description of the Drawings

[0024] [Figure 1] It is a diagram showing a schematic configuration of a chuck device according to an embodiment of the present invention. [Figure 2] It is a diagram showing the vicinity of the surface of the chuck of the chuck device according to an embodiment of the present invention. [Figure 3] It is a diagram showing an example of water supply of the chuck device according to an embodiment of the present invention. [Figure 4] This figure shows another example of water supply for a chuck device according to an embodiment of the present invention. [Figure 5] This figure shows another example of water supply for a chuck device according to an embodiment of the present invention. [Figure 6] This figure shows a pressing device and a vibrating device for a chuck device according to an embodiment of the present invention. [Figure 7] This figure shows an example of fluid supply for peeling in a chuck device according to an embodiment of the present invention. [Figure 8] This figure shows a schematic configuration of a chuck device according to another embodiment of the present invention. [Modes for carrying out the invention]

[0025] Hereinafter, a chuck device according to an embodiment of the present invention will be described in detail with reference to the drawings. Figure 1 is a diagram showing a schematic configuration of a chuck device 1 according to an embodiment of the present invention. As shown in Figure 1, the chuck device 1 is a device that holds a substrate-shaped workpiece 30 with a water film 20. The chuck device 1 is installed in a grinding device (not shown) for grinding the workpiece 30, a polishing device (not shown) for polishing the workpiece 30, a conveying device (not shown) for transporting the workpiece 30, etc. The chuck device 1 has a chuck 10 that holds the workpiece 30 via the water film 20.

[0026] The chuck 10 is a component that holds the workpiece 30, and has a substantially disc-like shape, formed from a porous structure. Details will be described later. Although not shown in the figures, in order to rotate the workpiece 30 during processing such as grinding, a rotating shaft that supports the chuck 10, a bearing that rotatably supports the rotating shaft, and a motor as a drive source that rotates the chuck 10 via the rotating shaft may be provided on the back side of the chuck 10.

[0027] Furthermore, a plurality of positioning pins, etc. (not shown) may be provided near the outer circumference of the surface 11 of the chuck 10 for positioning the workpiece 30. By providing positioning pins, etc., the workpiece 30 can be held approximately in the center of the surface 11 of the chuck 10.

[0028] The workpiece 30 is a substrate-like object that is subjected to grinding, polishing, and transport, and is, for example, a semiconductor substrate, a support substrate, or other laminate. The semiconductor substrate used as the workpiece 30 may be, for example, a silicon substrate with a diameter of approximately 300 mm. Circuits or the like may also be formed on the main surface of the workpiece 30.

[0029] With the workpiece 30 bonded to the chuck 10 by the water film 20, the surface opposite to the chuck 10, such as the top surface, is ground or polished with a grinding wheel (not shown). As a result, the workpiece 30 is formed to a thickness of, for example, 10 to 20 μm. In this way, the semiconductor substrate or the like, as the workpiece 30, is fixed to the chuck 10 by the water film 20 and processed to be thin and highly flat by grinding or the like.

[0030] Furthermore, if the workpiece 30 is a semiconductor substrate or the like with a device formed on one main surface, the chuck device 1 can hold the back surface of the workpiece 30 where the device is not formed, or it can hold the device surface where the device is formed. Therefore, the chuck device 1 can be used as a device to hold the workpiece 30 in processing steps for both the device surface grinding and the back surface grinding of the workpiece 30.

[0031] Furthermore, the workpiece 30 held by the chuck device 1 may be a laminate. That is, a laminate consisting of a semiconductor substrate and a support for the semiconductor substrate may be fixed to the surface 11 of the chuck 10.

[0032] Specifically, the laminated workpiece 30 comprises a semiconductor substrate or the like that to be subjected to grinding or other processing, and a support substrate that serves as a support for fixing the semiconductor substrate or the like. The semiconductor substrate or the like and the support substrate may be bonded together, for example, with a silicon resin.

[0033] The laminate may be bonded to the chuck 10 by a water film 20 on the side of the support substrate that is opposite to the semiconductor substrate, etc. That is, the semiconductor substrate, etc. may be fixed to the upper surface of the chuck 10 via the support substrate and the water film 20.

[0034] Here, the support substrate is a highly rigid plate-like body formed from, for example, glass, metal, ceramic, or synthetic resin. By bonding the support substrate to the semiconductor substrate, grinding of the semiconductor substrate and transport of the semiconductor substrate after it has been thinned can be easily performed.

[0035] Furthermore, the chuck device 1 may also be used when the support substrate itself is the target of grinding or other machining processes. That is, the workpiece 30 may be a support substrate or the like. Specifically, the support substrate or the like, as the workpiece 30, is fixed to the surface 11 of the chuck 10 by a water film 20, and the machined surface of the support substrate or the like is ground or polished with a grinding wheel or the like (not shown), similar to the machining of semiconductor substrates. In this way, by fixing a support substrate or the like used to support semiconductor substrates to the chuck 10 and performing grinding or other machining on the support substrate or the like, the main surface of the support substrate or the like can be flattened with high precision.

[0036] As described above, in the chuck device 1, a substrate-shaped workpiece 30, such as a semiconductor substrate, support, or a laminate thereof, is bonded to the chuck 10 by a water film 20. This reduces the thickness variation of the workpiece 30 after grinding and allows for high-precision flattening of the workpiece 30.

[0037] Furthermore, since the workpiece 30 is fixed by the water film 20, it does not come into contact with the chuck 10. This prevents damage to the workpiece 30 caused by contact with the chuck 10.

[0038] Furthermore, since the workpiece 30 is held by the water film 20, sludge generated during processing is not sucked into and remains in the chuck 10, unlike in a vacuum suction chuck. Therefore, it is possible to suppress a decrease in processing accuracy and the occurrence of cracks caused by sludge adhesion.

[0039] Figure 2 shows a schematic configuration of the area near the surface 11 of the chuck 10 of the chuck device 1. Referring to Figure 2, the chuck 10 is formed from a porous structure. Specifically, the chuck 10 is formed from a porous material such as silicon or ceramic, which has voids 14 through which water that forms a water film 20 can flow.

[0040] With this configuration, excess water supplied to the surface 11 of the chuck 10 is absorbed by the porous structure of the chuck 10, thereby efficiently forming a highly accurate, ultra-thin water film 20 that can suitably hold the workpiece 30.

[0041] More specifically, the porous structure of the chuck 10 is formed from particulate matter 12 with a particle size of 0.5 to 10 μm, preferably 0.5 to 8 μm, and more preferably 0.5 to 5 μm. In order to increase the area ratio of the flat surface 13, described later, to the entire surface 11 of the chuck 10, it is desirable to reduce the particle size of the particulate matter 12. This allows for the efficient absorption of excess water and the formation of a water film 20 of a suitable thickness that can support the workpiece 30 with a suitable holding force. In other words, a water film 20 of a suitable thickness can be formed in a short time.

[0042] Furthermore, a flat surface 13 is formed on the surface 11 of the chuck 10 that holds the workpiece 30, and is the contact surface in which the workpiece 30 and the particulate material 12 actually come into contact via the water film 20.

[0043] The formation of such a flat surface 13 eliminates direct contact between the particulate matter 12 constituting the porous structure and the workpiece 30, such as a semiconductor substrate, which is processed to be extremely thin. This allows for a uniform load to be applied to the entire surface of the workpiece 30, and the workpiece 30 can be held in a highly precise flat state via the water film 20. As a result, high-precision and highly efficient substrate processing and transport with a good yield can be achieved.

[0044] Specifically, the flat surface 13 is formed with an area ratio of 20 to 50%, more preferably 30 to 40%, of the total area of ​​the surface 11 of the chuck 10. This allows the workpiece 30 to be supported with precise flatness, enabling high-precision flattening and conveying.

[0045] Furthermore, the maximum height roughness (Rz) of the flat surface 13 of the particulate material 12 forming the porous structure must be such that it can form a water film 20 of sufficient thickness to achieve a lateral restraining force of 10 kPa or more. Specifically, the flat surface 13 is formed with a maximum height roughness (Rz) of 0.1 μm or less. This allows for high-precision planarization of the workpiece 30 held by the chuck device 1. The maximum height roughness (Rz) of the entire surface 11 of the chuck 10 is, for example, approximately 1 μm.

[0046] In other words, as described above, since the porous structure is formed from particulate matter 12 of a suitable particle size, and a flat surface 13 with a suitable surface roughness and a suitable surface ratio is formed on the surface 11 of the chuck 10, a water film 20 of a suitable thickness can be efficiently formed on the flat surface 13 across the entire surface 11 of the chuck 10. As a result, the workpiece 30 can be held appropriately in a short time, enabling high-precision and highly efficient processing and transport of the workpiece 30.

[0047] Figure 3 shows an example of water supply for the chuck device 1. In Figure 3, the arrows indicate the approximate direction of water flow. As shown in Figure 3, the chuck device 1 has a water supply device 21 that supplies water to the chuck 10 to form a water film 20.

[0048] The water supply device 21 is a device that supplies water to form a water film 20 on the surface 11 of the chuck 10. That is, according to the chuck device 1, the water that forms the water film 20 is supplied from the water supply device 21 to the surface 11 of the chuck 10. For example, if the chuck 10 is installed approximately horizontally such that the surface 11 that holds the workpiece 30 is facing upwards, water may be dripped onto the surface 11 of the chuck 10 from the water supply device 21 located above.

[0049] Then, after water is supplied to the surface 11 of the chuck 10, the workpiece 30 is placed on the surface 11 of the chuck 10, as shown in Figure 2. That is, for example, if the chuck 10 is installed approximately horizontally with the surface 11 facing upwards, the workpiece 30 or the chuck 10 is moved so that the workpiece 30 is mounted on the surface 11 of the chuck 10 from which water has been dripped.

[0050] When the workpiece 30 is joined to the surface 11 of the chuck 10 to which water has been supplied, as described above, any excess water between the workpiece 30 and the surface 11 of the chuck 10 is absorbed by the chuck 10, and a water film 20 of a suitable thickness is formed.

[0051] As will be explained in more detail later, specifically, by pressing the workpiece 30 and vibrating the chuck 10, excess water is drawn into the chuck 10, and a water film 20 is formed with a thickness of 50 to 500 nm. This allows the workpiece 30 to be held by the chuck 10 with a lateral restraining force of 10 kPa or more. In other words, the workpiece 30 is held on the surface 11 of the chuck 10 with a suitable holding force utilizing the surface tension of the water film 20. The lateral restraining force is the force that restrains the workpiece 30 in the lateral direction, i.e., along the surface 11, relative to the surface 11 of the chuck 10, and is a force that is approximately equivalent to the lateral shear stress between the chuck 10 and the workpiece 30.

[0052] Thus, the chuck device 1 can efficiently form an extremely thin, highly flattened water film 20 that exhibits suitable holding force. Therefore, workpieces 30 such as semiconductor substrates can be processed and transported with high precision, high yield, and high efficiency, thereby improving the productivity of semiconductor substrates and the like.

[0053] Referring to Figure 3, the water supply device 21 may be a device that supplies electrolyzed alkaline ionized water with a pH of 12 or higher as the water that forms the water film 20. This makes it possible to efficiently form an extremely thin, highly flattened water film 20 that exhibits suitable retention force.

[0054] Furthermore, the water supply device 21 may be a device that supplies fine bubble water with a bubble diameter of 100 nm or less as the water that forms the water film 20. This makes it possible to efficiently form an extremely thin, highly flattened water film 20 that exhibits suitable retention force.

[0055] Furthermore, the water supply device 21 may be a device that supplies water vapor as water to form the water film 20. That is, the water supply device 21 has a humidifying function and supplies humidified air containing a large amount of water vapor, i.e., high-humidity air, to the surface 11 of the chuck 10, and supplies a suitable amount of water to the surface 11 of the chuck 10 by condensation of water vapor.

[0056] Various methods can be employed as humidification methods by the water supply device 21, such as a steam method that evaporates water by electric heating, an ultrasonic method that releases fine water particles using ultrasound, a spray method that sprays water by other means, and an vaporization method that vaporizes water using an vaporization filter and a blower fan.

[0057] In this way, by adopting a method of supplying steam as the water supply device 21, excessive water supply is minimized, and a water film 20 that is extremely thin, highly flattened, and exhibits suitable retention force can be efficiently formed.

[0058] Figure 4 shows another example of water supply for the chuck device 1. In Figure 4, the arrows indicate the approximate direction of water flow. As shown in Figure 4, the water supply device 21 may be configured to supply water to the surface 11 of the chuck 10 from below. That is, if the chuck 10 is positioned approximately horizontally such that the surface 11 that holds the workpiece 30 is facing downwards, the water supply device 21 supplies water to the surface 11, which is the bottom surface in Figure 4, from below.

[0059] Specifically, the water supply device 21 may be configured to spray water onto the surface 11 of the chuck 10, or to supply water as steam. With this configuration, even when water is supplied to the surface 11 of the chuck 10 and the workpiece 30 is joined, a water film 20 of a suitable thickness can be efficiently formed.

[0060] Although not shown in the diagram, the water supply device 21 can supply water to the surface 11 of the chuck 10 to form a water film 20 even when the surface 11 is inclined, nearly vertical, etc. Then, when the workpiece 30 is joined after the water has been supplied, the chuck device 1 can easily form a suitable water film 20.

[0061] As mentioned above, the water supply device 21 may be a device that supplies electrolyzed alkaline ionized water as the water to form the water film 20, a device that supplies fine bubble water, or a device that supplies steam. For example, a water supply device 21 that supplies fine bubble water or steam as the water to form the water film 20 can efficiently supply an appropriate amount of water necessary for the formation of the water film 20 even when the surface 11 of the chuck 10 that holds the workpiece 30 is located below or to the side.

[0062] Figure 5 shows another example of water supply for the chuck device 1. In Figure 5, the arrows indicate the approximate direction of water flow. As shown in Figure 5, the water supply device 21 may be configured to supply water to the surface of the workpiece 30 that is held by the chuck 10. With this configuration of supplying water to the workpiece 30, when the workpiece 30 and the chuck 10 are joined after the water has been supplied, excess water is drawn into the chuck 10, and a water film 20 of a thickness suitable for holding the workpiece 30 can be efficiently formed.

[0063] Furthermore, when supplying water to the workpiece 30, the surface to which water is supplied is not limited to the downward horizontal plane as shown in Figure 5, similar to when supplying water to the surface 11 of the chuck 10. Although not shown in the illustration, the workpiece 30 may be positioned so that the surface to which water is supplied is upward, to the side, etc.

[0064] Figure 6 is a schematic diagram of the pressing device 25 and the vibrating device 27 of the chuck device 1. As shown in Figure 6, the chuck device 1 includes a pressing device 25 that presses the workpiece 30 and a vibrating device 27 that vibrates the chuck 10.

[0065] The pressing device 25 is a device that presses the workpiece 30, which is joined to the surface 11 of the chuck 10, toward the chuck 10 as indicated by the approximate direction of the arrow 26. For example, the pressing device 25 may be a device that presses the workpiece 30 using air pressure. Specifically, the pressing device 25 may have a case (not shown) that covers the workpiece 30, a compressor (not shown) that compresses the air supplied to the case to increase its pressure, etc.

[0066] The vibration device 27 is a device that vibrates the chuck 10 on which the workpiece 30 is placed in a lateral vibration, that is, a vibration along the surface 11, as roughly indicated by the arrow 28. The vibration device 27 may be, for example, an ultrasonic vibration device. The pressing device 25 and the vibration device 27 may also be provided in a workpiece transport device (not shown) that transports the workpiece 30 and places it in the chuck 10.

[0067] As described above, when the chuck 10 holds the workpiece 30, first, water is supplied by the water supply device 21 (see Figures 3 to 5) to form a water film 20 on the surface 11 of the chuck 10 or the workpiece 30.

[0068] After water is supplied to form a water film 20, the chuck 10 and the workpiece 30 are joined via the supplied water. Then, the pressing device 25 presses the workpiece 30 against the surface 11 of the chuck 10, and the vibrating device 27 applies lateral vibration to the chuck 10. As a result, the workpiece 30 does not directly contact the surface 11 of the chuck 10, but vibrates in such a way that it is rubbed against the surface 11 with the water in between.

[0069] In this way, the workpiece 30 is pressed and vibration is applied to the chuck 10, allowing the excess supplied water to be efficiently sent into the void 14 of the chuck 10 (see Figure 2). This makes it possible to form an extremely thin water film 20, which was difficult with conventional techniques.

[0070] Specifically, the pressure from the workpiece 30 and the vibration of the chuck 10 efficiently draw excess water between the workpiece 30 and the chuck 10 into the chuck 10. The water film 20 is then uniformly formed to a thickness of 50 to 500 nm, preferably 200 nm or less, and more preferably 100 nm or less.

[0071] As a result, the chuck 10 can hold the workpiece 30 with a lateral restraining force of 10 kPa or more, and if the water film 20 is thinned to 100 nm or less, the workpiece 30 can be held with a lateral restraining force of 50 kPa. In other words, the warping can be corrected by utilizing the meniscus force due to the surface tension of the water film 20, and the workpiece 30 can be held on the surface 11 of the chuck 10 with a suitable holding force that generates a lateral restraining force by the thinned water film 20.

[0072] Figure 7 shows an example of the fluid supply for stripping in the chuck device 1. As shown in Figure 7, the chuck device 1 is equipped with a fluid supply device 23 for stripping, which is used when removing the workpiece 30 from the chuck 10.

[0073] The separation fluid supply device 23 includes a pump (not shown) and, by operating the pump, supplies fluid to the back surface of the chuck 10 for separating the chuck 10 from the workpiece 30. The fluid supplied from the separation fluid supply device 23 is, for example, water or air. In Figure 7, the general direction of fluid flow is indicated by arrows.

[0074] As mentioned above, since the chuck 10 is formed from a porous structure, the fluid supplied to the back surface of the chuck 10 from the peeling fluid supply device 23 passes through the void 14 (see Figure 2) inside the chuck 10 and is supplied between the surface 11 of the chuck 10 and the workpiece 30.

[0075] This increases the thickness of the water film 20 that holds the workpiece 30, widens the distance between the surface 11 of the chuck 10 and the workpiece 30, and reduces the holding force of the water film 20. As a result, the workpiece 30 can be easily removed.

[0076] For example, when air is supplied from the peeling fluid supply device 23, the water film 20 is pushed by the air supplied through the chuck 10 and discharged to the outside from between the workpiece 30 and the chuck 10. This removes the water film 20 that is joining the workpiece 30 and the chuck 10, allowing the workpiece 30 to be easily removed.

[0077] For example, when water is supplied from the peeling fluid supply device 23, the water film 20 thickens. This weakens the adsorption force due to the surface tension of the water film 20, reducing its holding power and allowing the workpiece 30 to be easily removed.

[0078] Furthermore, when separating the workpiece 30, the peeling fluid supply device 23 may sequentially supply a fluid such as water or air from near the outer circumference of the chuck 10 towards the center of the chuck 10. This ensures that outlets for the water from the water film 20 and the fluid supplied from the peeling fluid supply device 23 are secured near the outer circumference of the workpiece 30, while simultaneously supplying fluid from the peeling fluid supply device 23, thereby effectively removing the water film 20. The peeling fluid supply device 23 may also be configured to supply fluid to the entire back surface of the chuck 10 almost simultaneously.

[0079] In this way, the separation fluid supply device 23 can efficiently supply a fluid such as water or air between the workpiece 30 and the chuck 10 by operating a pump or the like. Then, the workpiece 30 can be easily separated from the chuck device 1 without applying excessive force to the workpiece 30, which has been thinned by processing such as grinding.

[0080] Furthermore, the peeling fluid supply device 23 can also be used as a water supply device 21 to supply water that forms a water film 20 to the chuck 10 or workpiece 30. By supplying high-pressure water to the chuck 10 or workpiece 30 using the peeling fluid supply device 23, water that forms a water film 20 can also be sprayed onto the surface 11 of the chuck 10.

[0081] By providing the peeling fluid supply device 23 described above, the chuck device 1 can be used as a device for fixing semiconductor substrates and the like that are to be ultra-thinned with high precision. With the chuck device 1, ultra-thinning and high uniformity of highly integrated semiconductor substrates and the like can be achieved, thereby increasing the speed of the process and the yield of semiconductor substrates and the like, as well as enabling the multilayering of three-dimensional semiconductor substrates and the like.

[0082] Figure 8 shows a schematic configuration of a chuck device 101 according to another embodiment of the present invention. Components that have the same or similar functions and effects as those in the embodiments already described are denoted by the same reference numerals, and their descriptions are omitted.

[0083] As shown in Figure 8, the chuck device 101 has a chuck 110 made of a multilayer porous structure. Specifically, the porous structure constituting the chuck 110 has a first porous layer 15 that constitutes the surface 11 of the chuck 110, and a second porous layer 16 laminated on the back side of the first porous layer 15.

[0084] The first porous layer 15 has substantially the same configuration as the porous structure of the chuck 10 (see Figure 2) described earlier. That is, the first porous layer 15 is formed from a porous material such as silicon or ceramic, and is made of particulate matter 12 with a particle size of 0.5 to 10 μm, preferably 0.5 to 8 μm, and more preferably 0.5 to 5 μm.

[0085] Furthermore, a flat surface 13 with a maximum height roughness (Rz) of 0.1 μm or less facing the workpiece 30 is formed on the surface 11 of the first porous layer 15, with an area ratio of 20 to 50%, more preferably 30 to 40%, of the total area.

[0086] This first porous layer 15 allows the workpiece 30, such as a semiconductor substrate, which is processed to be extremely thin, to be held with precise flatness. This enables high-precision planarization with a good yield.

[0087] The second porous layer 16 is formed from a porous material such as silicon or ceramic, which has a larger particle size than the first porous layer 15. In other words, the first porous layer 15 has a smaller particle size than the second porous layer 16.

[0088] Specifically, the second porous layer 16 is formed from particulate matter 17 with a particle size of 10 to 100 μm. This allows the second porous layer 16, with its large particle size and low water resistance, to efficiently absorb the water forming the water film 20, thereby efficiently forming a water film 20 of a suitable thickness.

[0089] The second porous layer 16 supports the first porous layer 15, which has a small particle size and a highly precise flat surface 13. Therefore, water is efficiently absorbed by the second porous layer 16, allowing a highly precise, flat, and suitable water film 20 to be formed on the surface 11 of the first porous layer 15 in a short time and efficiently.

[0090] Furthermore, since the second porous layer 16 has a larger particle size than the first porous layer 15, it can efficiently handle fluids such as water or air supplied from the peeling fluid supply device 23. Therefore, the chuck device 101 can efficiently remove the workpiece 30 from the chuck 110 in a short amount of time, thereby improving the productivity of semiconductor substrates and the like.

[0091] Although not shown in the diagram, other porous layers may be formed on the back side of the second porous layer 16. That is, the chuck 110 may be formed from a multilayer porous structure having three or more porous layers. This results in a highly accurate chuck device 101 that can perform the adsorption and detachment of the workpiece 30 even more efficiently.

[0092] It should be noted that the present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the invention. [Explanation of Symbols]

[0093] 1.101 Chuck device 10, 110 Chuck 11 Surface 12 Particulate matter 13 Flat surface 14 void 15. The first porous layer 16. The second porous layer 17 Particulate matter 20 water film 21 Water supply equipment 23. Fluid supply device for stripping 25 Pressing device 27 Vibration device 30 Work

Claims

1. A chuck that holds a substrate-shaped workpiece via a water film, The system includes a water supply device that supplies water to form the water film to the chuck or the workpiece, The chuck is formed from a porous structure, The surface of the chuck that holds the workpiece has a flat surface formed on it that faces the workpiece. The water supply device is characterized by supplying electrolyzed alkaline ionized water as the water that forms the water film.

2. A chuck that holds a substrate-shaped workpiece via a water film, The system includes a water supply device that supplies water to form the water film to the chuck or the workpiece, The chuck is formed from a porous structure, The surface of the chuck that holds the workpiece has a flat surface formed on it that faces the workpiece. The water supply device is a chuck device characterized by supplying fine bubble water as the water that forms the water film.

3. A chuck that holds a substrate-shaped workpiece via a water film, A pressing device for pressing the workpiece toward the chuck, The chuck is vibrated in a direction along the surface of the chuck that holds the workpiece, The chuck is formed from a porous structure, The aforementioned surface has a flat surface formed on it that faces the workpiece. A chuck device characterized in that, after water that forms the water film is supplied to the chuck or the workpiece and the workpiece is placed in the chuck, the pressing device presses the workpiece and the vibrating device vibrates the chuck.

4. The system includes a water supply device that supplies water to form the water film to the chuck or the workpiece, The chuck device according to claim 3, characterized in that the water supply device supplies water vapor as the water that forms the water film.

5. The porous structure is formed from particulate matter with a particle size of 0.5 to 10 μm. The chuck device according to any one of claims 1 to 4, characterized in that the flat surface is formed in an area ratio of 20 to 50% of the total surface area.

6. The chuck device according to any one of claims 1 to 4, characterized in that the flat surface has a maximum height roughness (Rz) of 0.1 μm or less.

7. The porous structure comprises a first porous layer constituting the surface and a second porous layer laminated on the back side of the first porous layer. The chuck device according to any one of claims 1 to 4, characterized in that the first porous layer has a smaller particle size than the second porous layer.

8. After the water that forms the water film is supplied to the chuck or the workpiece, the workpiece is placed on the chuck. The aforementioned water film is formed to a thickness of 50 to 500 nm. The chuck device according to any one of claims 1 to 4, characterized in that the workpiece is held in the chuck with a lateral restraining force of 10 kPa or more.

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