Pad Conditioner Cleaning System

Abstract

This provides a method for cleaning the conditioner head. [Solution] The pad conditioner head cleaning tool includes a first clamp configured to removably engage a first portion of a sponge with respect to the outer surface of a disc-shaped pad conditioner head at a first position, a second clamp configured to removably engage a second portion of the sponge with respect to the outer surface of a disc-shaped pad conditioner head at a second position, and an arm connecting the first clamp to the second clamp. The arm is flexible enough to separate the first and second clamps and fit them around the disc-shaped pad conditioner head, and has sufficient tension to bias the first and second clamps inward, pressing the sponge against the outer surface of the pad conditioner head.

Description

Technical Field

[0001] The present disclosure relates to chemical mechanical polishing, and more particularly to cleaning of a pad conditioner.

Background Art

[0002] Integrated circuits are typically formed on a substrate by sequentially depositing conductive, semiconductive, or insulating layers on a silicon wafer. One manufacturing step includes depositing a fill layer on a non-planar surface and planarizing the fill layer. In some applications, the conductive fill layer is planarized until the top surface of the patterned layer is exposed. In other applications, such as oxide polishing, the fill layer is planarized until a predetermined thickness remains on the non-planar surface. Further, planarization of the substrate surface is typically also required in photolithography.

[0003] Chemical mechanical polishing (CMP) is an accepted planarization method. In this planarization method, it is usually necessary to mount the substrate on a carrier head or a polishing head. Typically, the exposed surface of the substrate is applied to a rotating polishing pad. The carrier head presses the substrate against the polishing pad by applying a controllable load to the substrate. Typically, a polishing liquid is supplied to the surface of the polishing pad.

[0004] A polishing system typically includes a conditioner system having a conditioner head holding a conditioner disk having an abrasive lower surface for conditioning the polishing pad. Conditioning of the polishing pad maintains the polishing surface at a consistent roughness to ensure uniform polishing conditions between wafers.

Summary of the Invention

[0005] In one embodiment, a pad conditioner head cleaning tool comprises a first clamp, a second clamp, and an arm coupling. The first clamp is configured to removably engage a first portion of a sponge with respect to the outer surface of a disc-shaped pad conditioner head at a first position. The second clamp is configured to removably engage a second portion of the sponge with respect to the outer surface of the disc-shaped pad conditioner head at a second position. An arm connects the first clamp to the second clamp. The arm is flexible enough to allow the first and second clamps to be pulled apart and fitted around the disc-shaped pad conditioner head, and has sufficient tension to bias the first and second clamps inward, pressing the sponge against the outer surface of the pad conditioner head.

[0006] The embodiment may include one or more of the following features:

[0007] The first clamp and the second clamp can be arc-shaped. The arm can be arc-shaped. When the pad conditioner head cleaning tool is fixed to the pad conditioner head, the center of the arc of the arc-shaped first and second clamps can be the center of the conditioner head. The first clamp can be a unitary piece, and the second clamp can be a unitary piece. Each of the first and second clamps may have an upper flange and a lower flange configured to accommodate the conditioner head. The outer surfaces of each of the first and second clamps may be recessed. The first clamp, the second clamp, and the arm can be a unitary arcuate body with a gap between the first and second clamps. This gap is configured to receive a sponge.

[0008] This tool can contain a sponge. This sponge can be a dry sponge. This sponge can be a wet sponge. This sponge can be disc-shaped.

[0009] In another embodiment, a method for cleaning a pad conditioner head includes moving two clamping arms of a cleaning tool inward toward a disc-shaped pad conditioner head to press a sponge against the outer surface of the disc-shaped pad conditioner head, and creating relative motion between the cleaning tool and the pad conditioner head to wipe the pad conditioner head with the sponge.

[0010] The embodiments may include, but are not limited to, one or more of the following advantages: The quality of polishing may be improved, for example, by fewer scratches and defects caused by dry abrasive particles derived from polishing slurry deposits separated from the pad conditioner during the polishing process. Furthermore, the amount of wafers discarded due to defects can be reduced. The downtime of the polishing system due to maintenance can be significantly reduced. This improves the productivity of the polishing system and reduces operator time because less time is spent on the pad conditioner cleaning process. Switching between different cleaning modes (i.e., dry cleaning and wet cleaning) becomes easier. The cleaning process can be quickly changed by adjusting the pressure engagement of the tool with the pad conditioner. Furthermore, the cleaning process can be quickly changed by changing the sponge type and / or adding cleaning fluid.

[0011] Details of one or more embodiments are shown in the accompanying drawings and the following description. Other embodiments, features, and advantages will become apparent from this description and drawings, as well as from the claims. [Brief explanation of the drawing]

[0012] [Figure 1A]This is a schematic cross-sectional view of a pad conditioner system, showing the conditioner head engaged with the polishing pad of a chemical mechanical polishing system. [Figure 1B] Figure 1A is a schematic cross-sectional view of the pad conditioner cleaning system of the chemical mechanical polishing system, with the pad conditioner head in the cleaning position. [Figure 2] Figure 1B is a schematic cross-sectional view of the pad conditioner cleaning system. [Figure 3] Figure 1B is a front perspective view of the pad conditioner cleaning system. [Figure 4] This is a front perspective view of the pad conditioner cleaning system installed on the pad conditioner system, which is separated from the chemical mechanical polishing system shown in Figure 1. [Figure 5A] Figure 1B is a front view of the first sponge. [Figure 5B] Figure 1B is a front view of the second sponge. [Figure 6] This diagram shows how to clean the pad conditioner. [Modes for carrying out the invention]

[0013] The same reference numerals and symbols used in various drawings refer to the same element.

[0014] During chemical mechanical polishing, a polishing fluid, such as an abrasive polishing slurry, is supplied to the surface of the polishing pad. The polishing system typically includes a conditioning system having a conditioner head and a conditioner disc having an abrasive underside for performing the conditioning of the polishing pad.

[0015] As the platen and polishing pad rotate, the polishing fluid can move centrifugalally from the polishing pad. Some of the polishing fluid can flow off the polishing pad and collect in the basin, but some of it can splash and adhere to the conditioner head. When this happens, the polishing fluid can form larger particles on the conditioner head, for example, by agglomeration or simply by drying. The accumulation of dried or agglomerated polishing fluid on the polishing pad over time has many detrimental effects. For example, these larger particles can detach and return to the polished surface, thus creating a risk of scratch formation and defects. A considerable amount of unproductive time is required to clean the conditioner head and conditioner disc to prevent the accumulation of dried polishing fluid.

[0016] A conditioner head cleaning tool that can be easily attached to the conditioner head without requiring disassembly of the equipment can mitigate these harmful effects.

[0017] Figure 1A shows a polishing system 20 that is operable to polish a substrate 10. The polishing system 20 includes a rotatable platen 24 on which a polishing pad 30 is positioned. The polishing system 20 may further include a platen shield 26 surrounding the platen 24, separated from the rotatable platen 24 by an annular gap 22. The rotatable platen 24 is operable to rotate around an axis 28. For example, a motor 30 can rotate a drive shaft 32 to rotate the rotatable platen 24.

[0018] The polishing system 20 includes a carrier head 70 that is operable to hold the substrate 10 relative to the polishing pad 30. The carrier head 70 is suspended from a support structure 72, such as a carousel or track, and is connected by a carrier drive shaft 74 to a carrier head rotary motor 76 so that the carrier head can rotate around an axis 71. Furthermore, the carrier head 70 can reciprocate laterally across the polishing pad 30, for example by moving in the radial grooves of the carousel 72 when driven by an actuator, or by the rotation of the carousel when driven by a motor, or by moving back and forth along a track when driven by an actuator. During operation, the platen 24 rotates around its central axis 25, and the carrier head 70 rotates around its central axis 71 and translates laterally across the upper surface of the polishing pad 30.

[0019] The polishing system 20 may include a polishing fluid delivery arm 34. During polishing, the arm 34 is operable to distribute the polishing fluid 36. The polishing fluid 36 may be a slurry containing abrasive particles. The polishing fluid 36 may be called by many names, for example, abrasive polishing slurry, abrasive polishing liquid, or polishing slurry.

[0020] The polishing system 20 can further include a conditioner system 40 having a rotatable conditioner head 42, and the rotatable conditioner head 42 can include an abrasive lower surface for conditioning the polishing surface 38 of the main polishing pad 30, for example, on a removable conditioning disk. The conditioner system 40 can further include a motor 44 for driving the conditioner head 42 and a drive shaft 46 connecting the motor 44 to the conditioner head 42. The conditioner system 40 can further include an actuator configured to move the conditioner head 40 laterally across the polishing pad 30. The conditioner system 40 can further include an arm 88 for rotating the pad conditioner head 42 and moving the pad conditioner head 42 laterally to place it on or remove it from the polishing pad 30. A notch or cutout 22 can be formed in the platen shield 26 to allow the conditioner head 40 to move laterally and disengage from the polishing pad 30 as shown in FIG. 4.

[0021] A portion of the polishing liquid 36 can flow off the polishing pad 30 and can be collected below the polishing system 20, but a portion of the polishing liquid 36 on the polishing pad 30 can adhere to the conditioner head 42. Further, conditioning of the polishing pad 30 can remove polishing debris from the polishing pad 30, and this debris can also adhere to the conditioner head 42. In either case, the polishing liquid 36 on the carrier head 70 can dry and further accumulate on the conditioning pad head 42.

[0022] FIG. 1B shows a conditioner pad head cleaning tool 50 installed on a conditioner head 42 of a polishing system 20. The conditioner pad head cleaning tool 50 includes a sponge holder 52 and a sponge 54. As shown in FIG. 2, the sponge holder 52 biases the sponge 54 against one or more surfaces of the pad conditioner head 42, such as the upper surface 48a or the side surface 48b, for cleaning the pad conditioner head 42.

[0023] Referring to FIGS. 5A and 5B, the sponge 54 can be disk-shaped. The sponge 54 can have an opening 90 disposed at the center 96 of the sponge and extending through the body of the sponge. The opening 90 is sized to accommodate the diameter of a drive shaft 46 that connects a motor 44 to the conditioner head 42. Slots 92 extend from the periphery 94 of the sponge 54 to this void. The slots 92 enable the sponge 54 to be placed around the pad conditioner head 42.

[0024] The sponge 54 is made of a soft, porous, and absorbent material. The sponge 54 can be made of a natural material or a synthetic material. For example, the sponge 54 can be formed from natural materials such as vegetable cellulose, animal sponge, hemp, or wood fiber. Alternatively, the sponge 54 can also be formed from synthetic materials such as polyester or polyurethane.

[0025] The sponge 54 can be a dry sponge or a wet sponge. A dry sponge does not contain any fluid chemicals added to the sponge. A dry sponge can be used for scraping. Referring to Figure 5A, a dry sponge can have a waffle-like surface texture, which can enhance scraping. A wet sponge contains fluids added to the sponge. As shown in Figure 5B, a wet sponge can be used to scrape off deposits of dry abrasive 36, to soften and loosen deposits of dry abrasive 36, or to apply chemicals to the pad conditioning head 42. For example, deionized water, isopropyl alcohol, or potassium hydroxide can be applied to the sponge.

[0026] Referring to Figures 2-4, the sponge holder 52 includes two clamps 56a and 56b. Each clamp 56 has an upper jaw 58 and a lower jaw 60. A frame 62 connects the upper jaw 58 and the lower jaw 60. The first clamp 56a has an upper jaw 58a and a lower jaw 60a connected by a frame 62a, configured to engage a first portion 64 of the sponge 54 with the conditioner head 42. The second clamp 56b has an upper jaw 58b and a lower jaw 60b connected by a frame 62b, configured to engage a second portion 66 of the sponge 54 with the conditioner head 42. The upper jaw 56 and the lower jaw 58 are connected to move, for example, they can be spread apart, so that they can be attached to the conditioner head 42.

[0027] The two clamps 56a and 56b are arc-shaped, i.e., arc-shaped when viewed from above. The outer surfaces of the upper jaw 58 and lower jaw 60 may have recesses 78 formed in the upper surface 80. The first clamp 56a has an upper surface 80 with a recess 78a. The second clamp 56b has an upper surface 80 with a recess 78b. The recesses 78a and 78b are configured to reinforce the operator's grip on the clamps 56a and 56b. The bottom surfaces 82 of the clamps 56a and 56b may also have recesses 78.

[0028] The inner surfaces of the upper jaw 58 and lower jaw 60 can be flat, as shown in Figure 2, for example, or convex, as shown in Figure 3, for example.

[0029] The clamps 56a and 56b are connected by an arm coupling 68, as shown in Figure 3. The coupling arm can be arc-shaped. The arm coupling 68 is flexible enough to allow the first clamp 56a and the second clamp 56b to spread apart and fit around the pad conditioner head 42, and has enough tension to bias the first clamp 56a and the second clamp 56b inward and engage with the outer surface 48 of the pad conditioner head 42. When the sponge is spread along the outer surface 48, the first clamp 56a and the second clamp 56b can press the sponge 54 inward against the outer surface 48 of the conditioner head 48. The first clamp 56 and the second clamp 56b are positioned by the arm coupling 68 such that the centers of the arcs of the first clamp and the second clamp are centered on the conditioner head 42 when the pad conditioner head cleaning tool 50 is fixed to the pad conditioner head 42. The first clamp 56b, the second clamp 56b and the arm coupling 68 can be a single piece. Each clamp has an upper flange and a lower flange configured to accommodate the conditioner head.

[0030] The sponge 54 is held by the sponge holder 52 such that its outer surface 84 is pressed against at least one surface 48 of the pad conditioner head 42. During operation, for example, an operator can rotate the sponge holder 52 and the sponge 54 around the axis 86. Meanwhile, the pad conditioner head 42 remains stationary. In some embodiments, the sponge holder 52 and the sponge 54 are rotated alternately clockwise and counterclockwise. Alternatively, the pad conditioner head 42 can be rotated around the axis 86 by, for example, rotating the drive shaft. Meanwhile, the operator holds the sponge holder 52 and the sponge 54 stationary. In either case, the sponge holder 52 holds the sponge 54 in contact with the pad conditioner head 42, and this relative motion wipes or rubs off any buildup of abrasive fluid 36.

[0031] The sponge holder can be made of elastic plastic. For example, the sponge holder can be made of steel, aluminum, high-density polyethylene, or a composite material.

[0032] Figure 6 shows a method 600 for cleaning a pad conditioning head using a pad conditioner head cleaning tool. In 602, a sponge is placed in the gap of the pad conditioner head cleaning tool. Alternatively, the sponge can be placed directly on the pad conditioner head. In 604, the cleaning tool is placed on the conditioner head. Placing the pad conditioner head cleaning tool may include spreading the first and second clamps, moving the cleaning tool to surround the conditioner head (and sponge), and releasing the first clamp to hold the sponge against the conditioner head. For example, pressure applied by the operator to the outside of the clamps can bring the sponge into further contact with the pad conditioner head. In 606, the sponge rubs against the pad conditioner head. The sponge is in contact with the pad conditioner head. Rubbing the pad conditioner head may include rotating the pad conditioner head and / or rotating the pad conditioner head tool. In some embodiments, rubbing involves alternating directions of clockwise and counterclockwise motion. The pad conditioner head can be rubbed with a dry sponge. A damp sponge can be moistened with a cleaning solution. The pad conditioner head can then be rubbed with the damp sponge. In 608, the pad conditioner head cleaning tool is removed from the pad conditioner head.

[0033] Several embodiments have been described. Nevertheless, it is understood that various modifications can be made. Therefore, other embodiments are included in the claims below.

Claims

1. A first clamp is configured to removably engage a first portion of a sponge with respect to the outer surface of a disc-shaped pad conditioner head at a first position, A second clamp is configured to removably engage the second portion of the sponge with respect to the outer surface of the disc-shaped pad conditioner head at a second position, An arm connecting the first clamp to the second clamp, having sufficient flexibility to separate the first clamp and the second clamp and fit them around the disc-shaped pad conditioner head, and having sufficient tension to bias the first clamp and the second clamp inward and press the sponge against the outer surface of the pad conditioner head, and A pad conditioner head cleaning tool equipped with [features / equipment].

2. The tool according to claim 1, wherein the arm is arc-shaped.

3. The tool according to claim 1, wherein the first clamp and the second clamp are arc-shaped.

4. The tool according to claim 3, wherein when the pad conditioner head cleaning tool is fixed to the pad conditioner head, the centers of the arcs of the first clamp and the second clamp are the centers of the conditioner head.

5. The tool according to claim 1, wherein the first clamp is a single piece and the second clamp is a single piece.

6. The tool according to claim 5, wherein each of the first clamp and the second clamp has an upper flange and a lower flange configured to accommodate the conditioner head.

7. The tool according to claim 5, wherein portions of the outer surfaces of the first clamp and the second clamp are recessed.

8. The tool according to claim 1, wherein the first clamp, the second clamp, and the arm are an integral arc-shaped body with a gap between the first clamp and the second clamp, and the gap is configured to receive the sponge.

9. The tool according to claim 1, further comprising a sponge.

10. The tool according to claim 9, wherein the sponge is a dry sponge.

11. The tool according to claim 9, wherein the sponge is a moist sponge.

12. The tool according to claim 9, wherein the sponge is disc-shaped.

13. A method for cleaning a pad conditioner head, Insert a sponge into the gap of the pad conditioner head cleaning tool. The pad conditioner head cleaning tool includes, A first clamp is configured to removably engage a first portion of a sponge with respect to the outer surface of a disc-shaped pad conditioner head at a first position, A second clamp is configured to removably engage the second portion of the sponge with respect to the outer surface of the disc-shaped pad conditioner head at a second position, An arm connecting the first clamp to the second clamp, having sufficient flexibility to separate the first clamp and the second clamp and fit them around the disc-shaped pad conditioner head, and having sufficient tension to bias the first clamp and the second clamp inward and press the sponge against the outer surface of the pad conditioner head, and The method further comprises, The sponge is brought into contact with the pad conditioner head, and The pad conditioner head is rubbed with the aforementioned sponge. A method for cleaning a pad conditioner head, including the following.

14. The sponge is placed in the gap of the pad conditioner head cleaning tool. Extend the first clamp to move the sponge into the gap, The first portion of the sponge is placed in the gap and inside the first clamp. To release the first clamp and hold the first portion of the sponge, Extend the second clamp to move the sponge into the gap, The second portion of the sponge is placed in the gap and inside the second clamp, and To release the second clamp and hold the second portion of the sponge. The method according to claim 13, further comprising:

15. The method according to claim 13, further comprising removing the pad conditioner head cleaning tool from the pad conditioner head.

16. A method for cleaning a conditioner head, Move the two clamp arms of the cleaning tool inward toward the disc-shaped pad conditioner head, pressing the sponge against the outer surface of the disc-shaped pad conditioner head, and To create relative motion between the cleaning tool and the pad conditioner head, the sponge is used to wipe the pad conditioner head. A method that includes this.

17. The method according to claim 16, wherein generating relative motion includes rotating the pad conditioner head.

18. The method according to claim 17, wherein generating relative motion includes rotating the pad conditioner head tool in alternating clockwise and counterclockwise directions.

19. The method according to claim 16, wherein the sponge is a dry sponge.

20. To provide a moist sponge by wetting the aforementioned sponge with a cleaning solution, and Wipe the pad conditioner head with the aforementioned damp sponge. The method according to claim 16, further comprising:

Images