Patent Application
20240165759
The present invention relates to a workpiece processing apparatus and a workpiece processing method for processing a workpiece, such as a wafer, a substrate, or a panel.
Devices, such as a memory circuit, a logic circuit, and an image sensor (e.g., a CMOS sensor) are becoming more highly integrated these days. In a process of forming such devices, foreign matter, such as fine particles or dust, may adhere to the devices. Foreign matter adhering to a device can cause a short-circuit between interconnects or can cause a circuit defect. Therefore, in order to enhance a reliability of the device, it is necessary to clean a workpiece on which the device is formed to remove the foreign matter on the workpiece.
Foreign matter, such as fine particles or dust, as described above may also adhere to a back surface (or a non-device surface) of the workpiece. If such foreign matter adheres to the back surface of the workpiece, the workpiece can separate from a stage reference plane of an exposure apparatus, or a surface of the workpiece can incline with respect to the stage reference plane. As a result, patterning shift or focal distance shift can occur. In order to prevent such problems, it is necessary to prevent the foreign matter from adhering to the back surface of the workpiece.
Conventionally, a Bernoulli chuck has been used as a mechanism for supporting a workpiece, such as a wafer, a substrate, or a panel. The Bernoulli chuck is configured to generate a suction force by emitting fluid using Bernoulli's theorem, and support the workpiece in a non-contact manner via the fluid.
It is therefore an object of the present invention to provide a workpiece processing apparatus capable of removing static electricity generated in a Bernoulli chuck during processing of a workpiece while the workpiece is supported by the Bernoulli chuck.
In an embodiment, there is provided a workpiece processing apparatus for processing a surface of a workpiece, comprising: a workpiece supporting device configured to support the workpiece; and a processing head configured to process the surface of the workpiece, wherein the workpiece supporting device has a fluid supply line for passing fluid therethrough, and a Bernoulli chuck coupled to the fluid supply line, the Bernoulli chuck is configured to attract the surface of the workpiece by emitting the fluid, and at least part of the Bernoulli chuck is made of a conductive material and is grounded.
In an embodiment, the fluid comprises gas, and the workpiece supporting device further has an ionizer configured to ionize the gas flowing through the fluid supply line.
In an embodiment, the fluid comprises carbonated water, the workpiece supporting device further has a carbonated-water supply source, and the fluid supply line is coupled to the carbonated-water supply source.
In an embodiment, the workpiece supporting device further has rollers configured to contact an edge portion of the workpiece, and at least part of each roller is made of a conductive material and is grounded.
In an embodiment, the conductive material comprises a conductive resin or a conductive ceramic.
In an embodiment, there is provided a workpiece processing apparatus for processing a surface of a workpiece, comprising: a workpiece supporting device configured to support the workpiece; and a processing head configured to process the surface of the workpiece, wherein the workpiece supporting device includes: a fluid supply line for passing gas therethrough; an ionizer configured to ionize the gas flowing through the fluid supply line; a Bernoulli chuck coupled to the fluid supply line and configured to attract the surface of the workpiece by emitting the ionized gas; a liquid ejecting member surrounding the Bernoulli chuck and configured to emit carbonated water around the Bernoulli chuck; and a carbonated-water supply source for supplying the carbonated water to the liquid ejecting member.
In an embodiment, at least a part of the Bernoulli chuck and/or at least a part of the liquid ejecting member is made of a conductive material and is grounded.
In an embodiment, the workpiece supporting device further has rollers configured to contact an edge portion of the workpiece, and at least part of each roller is made of a conductive material and is grounded.
In an embodiment, the conductive material comprises a conductive resin or a conductive ceramic.
In an embodiment, there is provided a workpiece processing method of processing a surface of a workpiece, comprising: attracting the surface of the workpiece by a Bernoulli chuck by emitting fluid from the Bernoulli chuck; and processing the surface of the workpiece by a processing head while the workpiece is attracted by the Bernoulli chuck, wherein at least part of the Bernoulli chuck is made of a conductive material and is grounded.
In an embodiment, the fluid emitted from the Bernoulli chuck comprises an ionized gas.
In an embodiment, the fluid emitted from the Bernoulli chuck comprises carbonated water.
In an embodiment, the workpiece processing method further comprises bringing rollers into contact with an edge portion of the workpiece to support the workpiece, wherein at least part of each roller is made of a conductive material and is grounded.
In an embodiment, there is provided a workpiece processing method of processing a surface of a workpiece, comprising: emitting carbonated water to the surface of the workpiece from a liquid ejecting member surrounding a Bernoulli chuck, while attracting the surface of the workpiece by the Bernoulli chuck by emitting an ionized gas from the Bernoulli chuck; and processing the surface of the workpiece by a processing head while the workpiece is attracted by the Bernoulli chuck.
In an embodiment, at least a part of the Bernoulli chuck and/or at least a part of the liquid ejecting member is made of a conductive material and is grounded.
In an embodiment, the workpiece processing method further comprises bringing rollers into contact with an edge portion of the workpiece to support the workpiece, wherein at least part of each roller is made of a conductive material and is grounded.
According to the present invention, at least part of the Bernoulli chuck is made of the conductive material and is grounded, so that static electricity generated in the Bernoulli chuck can be removed.
Further, according to the present invention, static electricity generated in the Bernoulli chuck can be removed by passing the ionized gas and/or the carbonated water through the Bernoulli chuck.
Furthermore, according to the present invention, at least part of the roller is made of the conductive material and is grounded, so that static electricity generated in the workpiece can be removed.
Hereinafter, embodiments of the present invention will be described with reference to the drawings. Identical or corresponding elements are denoted by the same reference numerals, and their repetitive explanations will be omitted.
The workpiece supporting device 10 includes a plurality of rollers 11 which can contact a periphery of the workpiece W, and a plurality of Bernoulli chucks 12 configured to support the first surface (or a lower surface) 2a of the workpiece W with fluid. The workpiece supporting device 10 includes a roller rotating mechanism (not shown) configured to rotate each roller 11 about the central axis of the roller 11. The Bernoulli chucks 12 are configured to attract the first surface 2a of the workpiece W via flows of the fluid, and support the workpiece W in a non-contact manner. In this specification, each Bernoulli chuck 12 is defined as a chuck configured to emit fluid to generate a suction force utilizing Bernoulli's theorem.
In this embodiment, the first surface 2a of the workpiece W is a back surface of the workpiece W on which no device is formed or device is not to be formed, i.e., a non-device surface. A second surface 2b of the workpiece W, which is opposite the first surface 2a, is a surface on which devices are formed or devices are to be formed, i.e., a device surface. In this embodiment, the workpiece W is horizontally supported by the workpiece supporting device 10 with the first surface 2a facing downward.
The polishing heads 20 are disposed at a lower side of the workpiece W supported by the workpiece supporting device 10. Each polishing head 20 includes a pressing member 21 configured to press the polishing tape 3 against the first surface 2a of the workpiece W, and a pressing mechanism 22 configured to push the pressing member 21 upward. The pressing mechanism 22 pushes the pressing member 21 upward to cause the pressing member 21 to bring the polishing tape 3 into sliding contact with the first surface 2a of the workpiece W from a back side of the polishing tape 3 to thereby polish the first surface 2a of the workpiece W with the polishing tape 3.
The polishing-tape feeding mechanism 30 includes a tape feeding reel 31 configured to feed the polishing tape 3, and a tape take-up reel 32 configured to collect the polishing tape 3. The tape feeding reel 31 and the tape take-up reel 32 are coupled to tension motors 31a and 32a, respectively. The tension motors 31a and 32a are fixed to a reel base 33. The polishing tape 3 is advanced or fed from the tape feeding reel 31 to the tape take-up reel 32 via the polishing heads 20 in a direction indicated by arrows by rotating the tape take-up reel 32 in a direction indicated by an arrow. A plurality of guide rollers 34 are arranged to guide the polishing tape 3 such that the polishing tape 3 advances in a direction parallel to the first surface 2a of the workpiece W. The plurality of guide rollers 34 are fixed to a not-shown holding member.
The tension motor 31a can apply tension to the polishing tape 3 by applying a predetermined torque to the tape feeding reel 31. The tension motor 32a is controlled so as to advance the polishing tape 3 at a constant speed. An advancing speed of the polishing tape 3 can be changed by changing a rotating speed of the tape take-up reel 32. In one embodiment, the advancing direction of the polishing tape 3 may be opposite to the direction indicated by the arrows in
The polishing apparatus 1 may further include a rinsing-liquid supply nozzle (not shown) and a protective-liquid supply nozzle (not shown). The rinsing-liquid supply nozzle is arranged below the workpiece W to supply a rinsing liquid (e.g., pure water or an alkaline chemical liquid) onto the first surface 2a of the workpiece W. The rinsing liquid supplied to a processing point of the first surface 2a can remove polishing debris from the first surface 2a of the workpiece W. In addition, the rinsing liquid supplied to area(s) other than the processing point can prevent the workpiece W from drying. The protective-liquid supply nozzle is arranged above the workpiece W to supply a protective liquid (e.g., pure water) onto the second surface 2b of the workpiece W. The protection liquid spreads over the second surface 2b of the workpiece W by centrifugal force to prevent the rinsing liquid containing polishing debris or foreign matter generated in the polishing of the workpiece W from contacting the second surface 2b of the workpiece W.
Operations of the polishing apparatus 1 are controlled by an operation controller 50. The operation controller 50 is electrically connected to the rollers 11 of the workpiece supporting device 10, the polishing heads 20, and the polishing-tape feeding mechanism 30. Operations of the rollers 11 of the workpiece supporting device 10, the polishing heads 20, and the polishing-tape feeding mechanism 30 are controlled by the operation controller 50. The operation controller 50 is composed of at least one computer.
The workpiece W is further supported by the plurality of Bernoulli chucks 12. These Bernoulli chucks 12 are arranged at both sides of the polishing tape 3 and the pressing members 21. Three Bernoulli chucks 12 are located at one side of the polishing tape 3 supported by the pressing members 21 and are aligned along the polishing tape 3. Similarly, three Bernoulli chucks 12 are located at the other side of the polishing tape 3 supported by the pressing members 21 and are aligned along the polishing tape 3. Each of the six Bernoulli chucks 12 is located away from the polishing tape 3 and the pressing members 21, but is adjacent to the polishing tape 3 and the pressing members 21. In this embodiment, the six workpiece supporting devices 12 are provided, while the number and positions of Bernoulli chucks 12 are not limited to this embodiment. For example, only one Bernoulli chuck 12 may be provided.
When the operation controller 50 opens the fluid supply valve 16, the fluid is supplied to the Bernoulli chuck 12 through the fluid supply line 15. The fluid supplied to the Bernoulli chuck 12 flows through the fluid flow passage 12c and is emitted from the fluid ejecting ports 12b toward an outside of the Bernoulli chuck 12. A flow of the fluid spreading outward from the attracting surface 12a generates a negative pressure in a space between a central portion of the attracting surface 12a and the first surface 2a of the workpiece W. As a result, the Bernoulli chuck 12 generates a suction force at the central portion of the attracting surface 12a to attract the workpiece W. A flow of the fluid is formed in a space between a peripheral portion of the Bernoulli chuck 12 and the first surface 2a of the workpiece W, so that the first surface 2a of the workpiece W is supported by this flow of the fluid. In this way, the Bernoulli chucks 12 can support the workpiece W in a non-contact manner while attracting the workpiece W. Therefore, the rollers 11 can rotate the workpiece W while the Bernoulli chucks 12 support the workpiece W.
Each Bernoulli chuck 12 of this embodiment is configured to radially emit the fluid from the fluid ejecting ports 12b toward the outside of the Bernoulli chuck 12. The Bernoulli chuck 12 is not limited to this embodiment as long as the Bernoulli chuck 12 can attract the first surface 2a of the workpiece W by the flow of the fluid and can support the workpiece W in a non-contact manner. For example, a cyclone-type Bernoulli chuck may be applied. The cyclone-type Bernoulli chuck is configured to attract the first surface 2a of the workpiece W and support the workpiece W in a non-contact manner by forming a swirling flow of the fluid to cause the fluid to flow toward the outside of the Bernoulli chuck 12.
At least part of each Bernoulli chuck 12 is made of a conductive material and is grounded. In particular, a portion of the Bernoulli chuck 12, which faces the first surface 2a of workpiece W and includes the attracting surface 12a and the fluid ejecting port 12b, is made of a conductive material and is grounded. Similarly, at least part of each roller 11 is made of a conductive material and is grounded. In particular, a portion of the roller 11 which is in contact with the workpiece W is made of a conductive material and is grounded. Examples of the conductive material forming the Bernoulli chuck 12 and the roller 11 include a conductive resin, a conductive ceramic, etc. The conductive resin may contain a resin, such as PEEK (polyetheretherketone), PPS (polyphenylene sulfide), or PVC (polyvinyl chloride), mixed with a conductive filler.
Thus, each Bernoulli chuck 12 of this embodiment is made of the conductive material and is grounded. Static electricity generated in portions of the Bernoulli chuck 12 which are indicated by S1 can be removed from the Bernoulli chuck 12 as indicated by dashed arrows. Furthermore, each roller 11 of this embodiment is made of the conductive material and is grounded. Static electricity generated in portions of the workpiece W which are indicated by S2 and S3 can be removed from the workpiece W via the roller 11 as indicated by dashed arrows.
The workpiece supporting device 10 includes an ionizer 40 configured to ionize the gas flowing through the fluid supply line 15. The ionizer 40 is provided downstream of the fluid supply valve 16 in a flow direction of the gas flowing through the fluid supply line 15. In one embodiment, the ionizer 40 may be provided upstream of the fluid supply valve 16 in the flow direction of the gas flowing through the fluid supply line 15. An ionized gas contains positively charged ions and negatively charged ions. A pipe of the fluid supply line 15 is made of a conductive material, such as a conductive resin, in order to retain the ions in the gas flowing through the fluid supply line 15.
The ionized gas flows into the Bernoulli chuck 12, flows through the Bernoulli chuck 12, and is emitted from the Bernoulli chuck 12. The ionized gas emitted from the Bernoulli chuck 12 spreads along the first surface 2a of the workpiece W. In
The carbonated water flows into the Bernoulli chuck 12, flows through the Bernoulli chuck 12, and is emitted from the Bernoulli chuck 12. The carbonated water emitted from the Bernoulli chuck 12 spreads along the first surface 2a of the workpiece W. In
The workpiece supporting device 10 of this embodiment includes a liquid ejecting member 13 located so as to surround the Bernoulli chuck 12. The liquid ejecting member 13 is coupled to a carbonated-water supply line 17, and carbonated water is supplied to the liquid ejecting member 13 from the carbonated-water supply line 17. The workpiece supporting device 10 has a carbonated-water supply source 41. The carbonated-water supply line 17 is coupled to the carbonated-water supply source 41. In
The liquid ejecting member 13 has a plurality of liquid ejecting ports 13a, a plurality of liquid flow passages 13b, a side wall 13c surrounding the Bernoulli chuck 12, and a bottom 13d coupled to the side wall 13c. An inner diameter of the side wall 13c is larger than an outer diameter of the Bernoulli chuck 12, and the Bernoulli chuck 12 is located inside the liquid ejecting member 13.
The liquid ejecting ports 13a are a plurality of holes formed in an upper surface of the liquid ejecting member 13. These liquid ejecting ports 13a are located on the same circumference at equal intervals when viewed from above the liquid ejecting member 13. The liquid ejecting ports 13a are formed in an upper surface of the side wall 13c, and are located so as to surround the Bernoulli chuck 12.
The liquid flow passages 13b extend in the side wall 13c downward from the liquid ejecting ports 13a toward the bottom 13d, further extend in the bottom 13d, and join together at a central portion of the bottom 13d. The liquid flow passages 13b communicate with the carbonated-water supply line 17 configured to supply the carbonated water to the liquid ejecting member 13. A carbonated-water supply valve 18 is attached to the carbonated-water supply line 17, and the carbonated-water supply valve 18 is electrically connected to the operation controller 50. Operations of the carbonated-water supply valve 18 are controlled by the operation controller 50. Examples of the carbonated-water supply valve 18 include an actuator-driven valve, such as a motor-driven valve and an electromagnetic valve.
As shown in
The Bernoulli chuck 12 of this embodiment is configured to radially emit the ionized gas from the fluid ejecting port 12b toward the outside of the Bernoulli chuck 12. The Bernoulli chuck 12 is not limited to this embodiment as long as the Bernoulli chuck 12 can attract the first surface 2a of the workpiece W and can support the workpiece W in a non-contact manner by the flow of the ionized gas. For example, a cyclone-type Bernoulli chuck may be applied. The cyclone-type Bernoulli chuck is configured to attract the first surface 2a of the workpiece W and support the workpiece W in a non-contact manner by forming a swirling flow of the ionized gas to cause the ionized gas to flow toward the outside of the Bernoulli chuck 12.
The liquid ejecting member 13 of this embodiment has the side wall 13c surrounding the Bernoulli chuck 12, while the liquid ejecting member 13 is not limited to this embodiment as long as the liquid ejecting member 13 is configured to emit the carbonated water around the Bernoulli chuck 12. For example, the liquid ejecting port 13a of the liquid ejecting member 13 may have an annular shape along a circumference of the bottom 13d when viewed from above the liquid ejecting member 13. Alternatively, the liquid ejecting member 13 may not have the side wall 13c, and may instead include a plurality of liquid nozzles configured to emit the carbonated water around the Bernoulli chuck 12.
When the operation controller 50 opens the fluid supply valve 16 and the carbonated-water supply valve 18, the ionized gas is supplied to the Bernoulli chuck 12 and the carbonated water is supplied to the liquid ejecting member 13. The ionized gas supplied to the Bernoulli chuck 12 flows through the fluid flow passage 12c, and is radially emitted from the plurality of fluid ejecting ports 12b toward the outside of the Bernoulli chuck 12. The carbonated water supplied to the liquid ejecting member 13 flows through the liquid flow passages 13b, and is emitted from the plurality of liquid ejecting ports 13a toward an outside of the liquid ejecting member 13. Dashed arrows in
At least a part of the Bernoulli chuck 12 and/or at least a part of the liquid ejecting member 13 of the embodiment shown in
The previous description of embodiments is provided to enable a person skilled in the art to make and use the present invention. Moreover, various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles and specific examples defined herein may be applied to other embodiments. Therefore, the present invention is not intended to be limited to the embodiments described herein but is to be accorded the widest scope as defined by limitation of the claims.
The present invention is applicable to a workpiece processing apparatus and a workpiece processing method for processing a workpiece, such as a wafer, a substrate, or a panel.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2021-035047 | Mar 2021 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2022/005070 | 2/9/2022 | WO |
