JP6373796B2 - Substrate polishing equipment - Google Patents

Description

  The present invention relates to a substrate polishing apparatus for polishing a substrate, and more particularly to a substrate polishing apparatus suitable for the case where harmful gas is generated.

  Conventionally, a dangerous chemical solution may be used in polishing a compound semiconductor substrate (wafer). For example, HF may be used for a SiC substrate. In addition, in the GaAs substrate, harmful arsenic may be mixed in the polishing waste liquid. Therefore, in the conventional substrate polishing apparatus, the polishing atmosphere is locally isolated and exhausted by downflow to prevent leakage of harmful substances to the outside (see Patent Document 1).

JP 2008-166709 A

  However, in the conventional substrate polishing apparatus, it is necessary to improve the sealing performance of each part of the apparatus and to increase the displacement, which requires a significant design change. Therefore, there has been a demand for the development of an apparatus that can efficiently prevent the diffusion of harmful gases without requiring a large-scale design change.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a substrate polishing apparatus that can efficiently prevent the diffusion of harmful gases.

  The substrate polishing apparatus of the present invention includes a rotating polishing table, a substrate holding unit that holds the substrate and presses the substrate against the polishing table for polishing, a local exhaust mechanism in which an intake head is disposed in the vicinity of the substrate holding unit, The suction head is disposed downstream of the substrate holding portion in the rotation direction of the polishing table.

  According to this configuration, even when harmful gas is generated during polishing of the substrate, the gas can be efficiently sucked by the intake head disposed in the vicinity of the substrate holding portion. In this case, since the intake head is disposed on the downstream side in the rotation direction of the polishing table, the gas flowing by the air flow (swirl flow) generated by the rotation of the polishing table can be efficiently sucked. In this way, with a relatively simple configuration of an intake head, gas diffusion can be efficiently prevented in the vicinity of a place where harmful gas is generated, and no large-scale design change is required.

  In the substrate polishing apparatus of the present invention, the intake speed of the intake head may be set higher than the rotational speed of the polishing table.

  The speed at which the gas is caused to flow by the airflow (swirl flow) generated by the rotation of the polishing table is considered to be approximately the same as (or less than) the rotation speed of the polishing table. In this case, since the suction speed of the suction head is set higher than the rotation speed of the polishing table, the gas flowing by the air flow (swirl flow) generated by the rotation of the polishing table is suitable according to the flow speed of the gas. Can be aspirated.

  In the substrate polishing apparatus of the present invention, the intake head includes a plurality of intake ports arranged in the radial direction of the polishing table, and the intake speed of the intake port outside in the radial direction is the radial direction among the plurality of intake ports. It may be set higher than the intake speed of the intake port inside.

  According to this configuration, harmful gas generated during polishing of the substrate can be sucked by the plurality of suction ports of the suction head. Since the rotation speed of the polishing table is higher on the outside than the inside in the radial direction, the speed at which the gas is caused to flow by the airflow (swirl flow) generated by the rotation of the polishing table is higher on the outside than in the radial direction (in the radial direction). There is a difference). In this case, the plurality of air inlets are aligned in the radial direction of the polishing table, and the intake speed of the radially outer intake port is set higher than the intake speed of the radially inner intake port. The gas flowing by the air flow (swirl flow) generated by the rotation can be preferably sucked according to the difference in the flow velocity of the gas (difference in the radial direction).

  According to the present invention, even when harmful gas is generated during polishing of the substrate, gas diffusion can be efficiently prevented in the vicinity of the place where the harmful gas is generated.

It is a top view which shows the whole structure of the substrate processing apparatus in 1st Embodiment. It is a perspective view which shows the structure of the grinding | polishing unit in 1st Embodiment. (A) It is a top view which shows the washing | cleaning part in 1st Embodiment. (B) It is a side view which shows the washing | cleaning part in 1st Embodiment. It is explanatory drawing which shows schematic structure of the substrate polishing apparatus in 1st Embodiment. It is a top view which shows the main structures of the substrate polishing apparatus in 1st Embodiment. It is a side view which shows the main structures of the substrate polishing apparatus in 1st Embodiment. It is explanatory drawing which shows schematic structure of the modification of 1st Embodiment. It is a top view which shows the main structures of the substrate polishing apparatus in 2nd Embodiment. It is a side view which shows the main structures of the substrate polishing apparatus in 2nd Embodiment. It is a top view which shows the main structures of the modification of 2nd Embodiment.

  Hereinafter, a substrate polishing apparatus according to an embodiment of the present invention will be described with reference to the drawings. In this embodiment, the case of a substrate processing apparatus that polishes a substrate by chemical mechanical polishing (CMP) is illustrated.

(First embodiment)
FIG. 1 is a plan view showing the overall configuration of the substrate processing apparatus according to the first embodiment. As shown in FIG. 1, the substrate processing apparatus includes a substantially rectangular housing 1, and the interior of the housing 1 is divided into a load / unload unit 2, a polishing unit 3 and a cleaning unit 4 by partition walls 1a and 1b. It is partitioned. The load / unload unit 2, the polishing unit 3, and the cleaning unit 4 are assembled independently. The substrate processing apparatus has a control unit 5 that controls the substrate processing operation.

The load / unload unit 2 includes two or more (four in this embodiment) front load units 20 on which wafer cassettes for stocking a large number of wafers (substrates) are placed. These front load portions 20 are arranged adjacent to the housing 1 and are arranged along the width direction (direction perpendicular to the longitudinal direction) of the substrate processing apparatus. The front load unit 20 can be equipped with an open cassette, a SMIF (Standard Manufacturing Interface) pod, or a FOUP (Front Opening Unified Pod). Where SMIF
The FOUP is a sealed container that can maintain an environment independent of the external space by accommodating a wafer cassette inside and covering with a partition wall.

  In addition, a traveling mechanism 21 is laid along the front load unit 20 in the load / unload unit 2, and two transfer robots that can move along the arrangement direction of the wafer cassettes on the traveling mechanism 21. A (loader) 22 is installed. The transfer robot 22 can access the wafer cassette mounted on the front load unit 20 by moving on the traveling mechanism 21. Each transfer robot 22 has two hands on the upper and lower sides. The upper hand is used to return the processed wafer to the wafer cassette, and the lower hand is used to take out the wafer before processing from the wafer cassette. Then, you can use the upper and lower hands properly. Furthermore, the lower hand of the transfer robot 22 is configured to be able to reverse the wafer by rotating around its axis.

  Since the load / unload unit 2 is an area where it is necessary to maintain the cleanest state, the inside of the load / unload unit 2 is higher than the outside of the substrate processing apparatus, the polishing unit 3, and the cleaning unit 4. Always maintained at pressure. The polishing unit 3 is the most dirty region because slurry is used as the polishing liquid. Therefore, a negative pressure is formed inside the polishing unit 3, and the pressure is maintained lower than the internal pressure of the cleaning unit 4. The load / unload unit 2 is provided with a filter fan unit (not shown) having a clean air filter such as a HEPA filter, a ULPA filter, or a chemical filter. From the filter fan unit, particles, toxic vapor, Clean air from which toxic gases have been removed is constantly blowing out.

  The polishing unit 3 is a region where the wafer is polished (flattened), and includes a first polishing unit 3A, a second polishing unit 3B, a third polishing unit 3C, and a fourth polishing unit 3D. The first polishing unit 3A, the second polishing unit 3B, the third polishing unit 3C, and the fourth polishing unit 3D are arranged along the longitudinal direction of the substrate processing apparatus as shown in FIG. The polishing unit 3 performs processing for polishing the surface (surface to be polished) of the wafer and removing the metal film formed on the surface to be polished.

  As shown in FIG. 1, the first polishing unit 3A includes a polishing table 30A to which a polishing pad 10 having a polishing surface is attached, and polishing while holding the wafer and pressing the wafer against the polishing pad 10 on the polishing table 30A. A top ring 31A for polishing, a polishing liquid supply nozzle 32A for supplying a polishing liquid or a dressing liquid (for example, pure water) to the polishing pad 10, and a dresser 33A for dressing the polishing surface of the polishing pad 10. And an atomizer 34A for spraying a mixed fluid of liquid (for example, pure water) and gas (for example, nitrogen gas) or a liquid (for example, pure water) to the polishing surface in the form of a mist.

  Similarly, the second polishing unit 3B includes a polishing table 30B to which the polishing pad 10 is attached, a top ring 31B, a polishing liquid supply nozzle 32B, a dresser 33B, and an atomizer 34B. The third polishing unit 3C includes a polishing table 30C to which the polishing pad 10 is attached, a top ring 31C, a polishing liquid supply nozzle 32C, a dresser 33C, and an atomizer 34C. The fourth polishing unit 3D includes a polishing table 30D to which the polishing pad 10 is attached, a top ring 31D, a polishing liquid supply nozzle 32D, a dresser 33D, and an atomizer 34D.

First polishing unit 3A, second polishing unit 3B, third polishing unit 3C, and fourth
Since the polishing units 3D have the same configuration, the first polishing unit 31A will be described below.

FIG. 2 is a perspective view schematically showing the first polishing unit 3A. The top ring 31A is supported by the top ring shaft. A polishing pad 10 is affixed to the upper surface of the polishing table 30A, and the upper surface of the polishing pad 10 constitutes a polishing surface for polishing the wafer W. Note that fixed abrasive grains may be used in place of the polishing pad 10. The top ring 31 </ b> A and the polishing table 30 </ b> A are configured to rotate around their axial centers as indicated by arrows. The wafer W is held on the lower surface of the top ring 31A by vacuum suction. At the time of polishing, the polishing liquid is supplied from the polishing liquid supply nozzle 32A to the polishing surface of the polishing pad 10, and the wafer W to be polished is pressed against the polishing surface by the top ring 31A and polished.

  Next, a transport mechanism for transporting the wafer will be described. As shown in FIG. 1, a first linear transporter 6 is disposed adjacent to the first polishing unit 3A and the second polishing unit 3B. The first linear transporter 6 has four transfer positions along the direction in which the polishing units 3A and 3B are arranged (first transfer position TP1, second transfer position TP2, and third transfer in order from the load / unload unit side). This is a mechanism for transferring the wafer between the position TP3 and the fourth transfer position TP4.

  Further, the second linear transporter 7 is disposed adjacent to the third polishing unit 3C and the fourth polishing unit 3D. The second linear transporter 7 has three transfer positions (a fifth transfer position TP5, a sixth transfer position TP6, and a seventh transfer in order from the load / unload unit side) along the direction in which the polishing units 3C and 3D are arranged. This is a mechanism for transporting the wafer between the positions TP7.

  The wafer is transferred to the polishing units 3A and 3B by the first linear transporter 6. As described above, the top ring 31A of the first polishing unit 3A moves between the polishing position and the second transport position TP2 by the swing operation of the top ring head. Therefore, the wafer is transferred to the top ring 31A at the second transfer position TP2. Similarly, the top ring 31B of the second polishing unit 3B moves between the polishing position and the third transfer position TP3, and the delivery of the wafer to the top ring 31B is performed at the third transfer position TP3. The top ring 31C of the third polishing unit 3C moves between the polishing position and the sixth transfer position TP6, and the delivery of the wafer to the top ring 31C is performed at the sixth transfer position TP6. The top ring 31D of the fourth polishing unit 3D moves between the polishing position and the seventh transfer position TP7, and the delivery of the wafer to the top ring 31D is performed at the seventh transfer position TP7.

  A lifter 11 for receiving a wafer from the transfer robot 22 is disposed at the first transfer position TP1. The wafer is transferred from the transfer robot 22 to the first linear transporter 6 through the lifter 11. A shutter (not shown) is provided between the lifter 11 and the transfer robot 22 in the partition wall 1a. When the wafer is transferred, the shutter is opened so that the wafer is transferred from the transfer robot 22 to the lifter 11. It has become. A swing transporter 12 is arranged between the first linear transporter 6, the second linear transporter 7, and the cleaning unit 4. The swing transporter 12 has a hand that can move between the fourth transfer position TP4 and the fifth transfer position TP5, and transfers the wafer from the first linear transporter 6 to the second linear transporter 7. Is performed by the swing transporter 12. The wafer is transferred to the third polishing unit 3C and / or the fourth polishing unit 3D by the second linear transporter 7. The wafer polished by the polishing unit 3 is transferred to the cleaning unit 4 via the swing transporter 12.

  FIG. 3A is a plan view showing the cleaning unit 4, and FIG. 3B is a side view showing the cleaning unit 4. In the cleaning unit 4, a process for cleaning and drying the wafer W polished by the polishing unit 3 is performed. As shown in FIGS. 3A and 3B, the cleaning unit 4 includes a first cleaning chamber 190, a first transfer chamber 191, a second cleaning chamber 192, a second transfer chamber 193, and a drying unit. It is partitioned into a chamber 194. In the first cleaning chamber 190, an upper primary cleaning module 201A and a lower primary cleaning module 201B arranged in the vertical direction are arranged. The upper primary cleaning module 201A is disposed above the lower primary cleaning module 201B. Similarly, in the second cleaning chamber 192, an upper secondary cleaning module 202A and a lower secondary cleaning module 202B arranged in the vertical direction are arranged. The upper secondary cleaning module 202A is disposed above the lower secondary cleaning module 202B. The primary and secondary cleaning modules 201A, 201B, 202A, and 202B are cleaning machines that clean a wafer using a cleaning liquid. Since these primary and secondary cleaning modules 201A, 201B, 202A, 202B are arranged along the vertical direction, there is an advantage that the footprint area is small.

  A temporary wafer placement table 203 is provided between the upper secondary cleaning module 202A and the lower secondary cleaning module 202B. In the drying chamber 194, an upper drying module 205A and a lower drying module 205B arranged in the vertical direction are arranged. The upper drying module 205A and the lower drying module 205B are isolated from each other. Filter fan units 207 and 207 for supplying clean air into the drying modules 205A and 205B are provided above the upper drying module 205A and the lower drying module 205B, respectively. The upper primary cleaning module 201A, the lower primary cleaning module 201B, the upper secondary cleaning module 202A, the lower secondary cleaning module 202B, the temporary placing table 203, the upper drying module 205A, and the lower drying module 205B are arranged on a frame (not shown). It is fixed via bolts.

  A first transfer robot 209 that can move up and down is arranged in the first transfer chamber 191, and a second transfer robot 210 that can move up and down is arranged in the second transfer chamber 193. The first transfer robot 209 and the second transfer robot 210 are movably supported by support shafts 211 and 212 extending in the vertical direction. The first transfer robot 209 and the second transfer robot 210 have a drive mechanism such as a motor inside thereof, and are movable up and down along the support shafts 211 and 212. The first transfer robot 209 has two upper and lower hands like the transfer robot 22. As shown by the dotted line in FIG. 3A, the first transfer robot 209 is disposed at a position where the lower hand can access the temporary table 180 described above. When the lower hand of the first transfer robot 209 accesses the temporary table 180, a shutter (not shown) provided on the partition wall 1b is opened.

  The first transfer robot 209 transfers the wafer W between the temporary placing table 180, the upper primary cleaning module 201A, the lower primary cleaning module 201B, the temporary placing table 203, the upper secondary cleaning module 202A, and the lower secondary cleaning module 202B. Operates to carry. The first transfer robot 209 uses the lower hand when transferring the wafer before cleaning (the wafer to which the slurry is attached), and uses the upper hand when transferring the cleaned wafer. The second transfer robot 210 operates to transfer the wafer W between the upper secondary cleaning module 202A, the lower secondary cleaning module 202B, the temporary placement table 203, the upper drying module 205A, and the lower drying module 205B. Since the second transfer robot 210 transfers only the cleaned wafer, it has only one hand. The transfer robot 22 shown in FIG. 1 takes out the wafer from the upper drying module 205A or the lower drying module 205B using the upper hand, and returns the wafer to the wafer cassette. When the upper hand of the transfer robot 22 accesses the drying modules 205A and 205B, a shutter (not shown) provided on the partition wall 1a is opened.

  Next, a characteristic configuration of the substrate polishing apparatus of the present embodiment will be described with reference to the drawings. FIG. 4 is an explanatory diagram showing a schematic configuration of the substrate polishing apparatus of the present embodiment, and FIGS. 5 and 6 are explanatory diagrams showing a main configuration of the substrate polishing apparatus of the present embodiment.

  As shown in FIGS. 4 to 6, the substrate polishing apparatus of the present embodiment includes a polishing table 30 having a polishing surface 10 on an upper surface, a top ring 31 that holds a wafer W having a surface to be polished on a lower surface, and a top A local exhaust mechanism 35 is provided in the vicinity of the ring 31. The polishing surface 10 is composed of, for example, a polishing pad. The polishing table 30 rotates in a predetermined rotation direction (clockwise in FIG. 5), and the top ring 31 polishes the surface to be polished (the lower surface in FIGS. 4 and 6) of the held wafer W by the polishing table 30. The surface to be polished of the wafer W is polished by pressing against the surface 10. The substrate polishing apparatus may include a table cover that covers the outside of the polishing table 30 and a top ring cover that covers the outside of the top ring 31.

  As shown in FIG. 5, the local exhaust mechanism 35 includes an intake head 36 disposed in the vicinity of the top ring 31. The intake head 36 is disposed on the downstream side (rotational direction side) in the rotational direction of the polishing table 30 with respect to the top ring 31. The intake head 36 includes a plurality of intake ports 37 aligned in the radial direction of the polishing table 30.

  As shown in FIG. 6, the intake port 37 of the intake head 36 is connected to an ejector 38, and intake air from the intake port 37 is performed by flowing compressed air through the ejector 38. The ejector 38 is configured to be able to adjust the intake speed of the intake port 37 by adjusting the flow rate of the compressed air. In this case, among the plurality of intake ports 37, the intake speed of the radially outer intake port 37 is set higher than the intake speed of the radially inner intake port 37 (see FIG. 5). The suction means from the suction port 37 is not limited to the ejector 38, and for example, a vacuum pump or the like may be used.

  The intake speed of the intake head 36 is preferably set higher than the rotational speed of the polishing table 30. In other words, the intake speed of the intake head 36 is set to be 1 or more times the rotational speed of the polishing table 30 (for example, 1 to 2 m / s). For example, the intake speed of the intake head 36 is set to 1.2 to 2 times the rotational speed of the polishing table 30. The suction speed of the suction head 36 can be set based on the rotational speed of the polishing table and the reference area. The reference area is calculated from the product of the diameter of the wafer W and the reference height. The reference height may be set based on the distance between the top ring 31 and the intake head 36. For example, the reference height is set to 0.3 to 3 times the distance between the top ring 31 and the intake head 36. Further, the reference height may be set based on the height from the polishing surface 10 to the upper end of the opening of the top ring 31 (the upper end of the retainer ring gap). For example, the reference height is set to 1 to 3 times the height from the polishing surface 10 to the upper end of the opening of the top ring 31 (the upper end of the gap of the retainer ring).

  As shown in FIG. 4, the local exhaust mechanism 35 is provided with an exhaust pipe 40 connected to the exhaust mechanism 39. The exhaust pipe 40 may be connected to a duct having an exhaust function, and a blower that is operated by an electric motor or the like may be attached to the exhaust pipe 40. The exhaust pipe 40 is provided with a gas-liquid separation mechanism 41. In this case, since the gas-liquid separation mechanism 41 is provided in the exhaust pipe 40, the gas and liquid separation mechanism 41 separates the gas and the liquid even when the liquid is mixed when the gas is sucked. The aspirated gas can be properly evacuated (separated from the liquid). A damper may be provided between the gas-liquid separation mechanism 41 and the exhaust mechanism 39.

  According to such a substrate polishing apparatus of the embodiment of the present invention, even when harmful gas is generated during polishing of the wafer W, gas diffusion is efficiently prevented in the vicinity of the place where the harmful gas is generated. Can do.

  That is, in the present embodiment, even when harmful gas is generated during polishing of the wafer W, the gas can be efficiently sucked by the intake head 36 disposed in the vicinity of the top ring 31. In this case, since the suction head 36 is disposed downstream (rotational direction side) in the rotation direction of the polishing table 30, the gas flowing by the air flow (swirl flow) generated by the rotation of the polishing table 30 is efficiently sucked. can do. Thus, with a relatively simple configuration of the intake head 36, gas diffusion can be efficiently prevented in the vicinity of the place where harmful gas is generated, and no large-scale design change is required.

  It is considered that the speed at which the gas is caused to flow by the airflow (swirl flow) generated by the rotation of the polishing table 30 is approximately the same as (or less than) the rotation speed of the polishing table 30. In this case, since the suction speed of the suction head 36 is set to be higher than the rotation speed of the polishing table 30, the gas flowing by the air flow (swirl flow) generated by the rotation of the polishing table 30 is changed to the speed at which the gas flows. Accordingly, suction can be suitably performed.

  In the present embodiment, harmful gas generated during polishing of the wafer W can be sucked by the plurality of air inlets 37 of the air intake head 36. Since the rotational speed of the polishing table 30 is higher on the outer side than the inner side in the radial direction, the speed at which the gas is caused to flow by the air flow (swirl flow) generated by the rotation of the polishing table 30 is higher on the outer side than the inner side in the radial direction (diameter). There is a difference in direction). In this case, the plurality of air inlets 37 are arranged in the radial direction of the polishing table 30, and the air intake speed of the air outlet 37 on the outer side in the radial direction is set higher than the air intake speed of the air inlet 37 on the inner side in the radial direction. The gas flowing by the air flow (swirl flow) generated by the rotation of the polishing table 30 can be suitably sucked according to the difference in the gas flow speed (the difference in the radial direction).

  Conventionally, the exhaust speed around the polishing table is set to a speed (for example, about 0.3 m / s) at which the gas can be smoothly exhausted without being rolled up by the airflow generated by the rotation of the polishing table. It was. On the other hand, the rotational speed (circumferential speed) of the polishing table is usually about 1 to 2 m / s. With such a conventional exhaust speed, if harmful gas is generated during polishing, the gas may spread on the polishing table at the rotation speed of the polishing table (a speed faster than the exhaust speed), and may easily evaporate and diffuse from the surface of the polishing table. there were. Further, in the conventional substrate polishing apparatus, for example, a cover is provided around the polishing table and exhaust is performed from the periphery of the polishing table through a normal exhaust line. There is a risk that exhausting cannot be performed when the engine stops. On the other hand, in the present embodiment, the ejector 38 is employed as the local exhaust mechanism 35, and a higher suction function than in the conventional case (when exhausting through a normal exhaust line) can be realized. Further, in the present embodiment, if the compressed air is supplied to the ejector 38, local exhaust on the polishing table is possible even when the function of the normal exhaust line is stopped. Safety can be ensured. As shown in FIG. 7, the ejector 35 may be provided at a position away from the intake head 36.

  The embodiments of the present invention have been described above by way of example, but the scope of the present invention is not limited to these embodiments, and can be changed or modified according to the purpose within the scope of the claims. is there.

  For example, in the above description, the example in which the intake speed of the intake head 36 is set higher than the rotational speed of the polishing table 30 has been described, but the intake speed of the intake head 36 is set slightly lower than the rotational speed of the polishing table 30. May be. That is, the intake speed of the intake head 36 may be set to be equal to or less than one time the rotational speed of the polishing table 30. For example, the intake speed of the intake head 36 may be set to 0.8 times the rotational speed of the polishing table 30.

(Second Embodiment)
The present embodiment relates to the exhaust amount of the wafer polishing chamber of the CMP apparatus and the polishing pad temperature. The temperature of the polishing pad surface and the polishing liquid (hereinafter referred to as “slurry”) spreading on the pad surface rises as heat energy is input by the polishing load. The present embodiment relates to a mechanism / device that lowers, manages, or controls the temperature.

  Conventionally, in order to remove heat from the pad surface and slurry and lower the temperature, for example, (1) a mechanism / device for removing heat by placing a cooling plate over the pad surface, or (2) spraying dry gas on the pad surface Mechanisms and devices that remove heat by latent heat of vaporization have been adopted.

  In order to increase the polishing rate, methods such as increasing the polishing surface pressure or increasing the relative speed of the polishing surface are conceivable. However, this increases the energy loss due to friction on the polishing surface, and the energy enters the polishing pad, the slurry, the wafer of the product to be polished, and the top ring that holds the wafer, causing each temperature to rise.

  As for the slurry, an increase in the polishing rate due to polishing (etching) due to the chemical performance of the slurry can be expected due to temperature rise. However, even if the temperature rises too much, the performance of the slurry may deteriorate and the original polishing performance may not be exhibited. Also with respect to the pad, when the temperature rises, the hardness and Young's modulus of the pad decrease, which may cause deterioration of the flatness of the polished surface of the wafer of the product to be polished. As for the top ring for holding the wafer, if the temperature rise is large, the mechanism for pressing the wafer against the pad is affected. Therefore, it is anxious to be able to manage and control the temperature rise due to polishing.

  Therefore, the contact heat conduction method (1) and the vaporization latent heat method (2) by dry gas blowing have been developed.

  However, in the conventional cooling plate method (1), the cooling plate comes into contact with a pad or slurry that contacts the wafer to be polished. For this reason, there is a concern about contamination (ions, particles) from the cooling plate, and a coating or cleaning device for the contact portion is required. In addition, there is a concern about a scratch problem on the wafer surface due to the fall of slurry adhering to the cooling plate, and a cleaning device for the entire cooling plate is required. As a result, the device itself becomes large. In addition, because the heat is removed by contact heat conduction, the method is proportional to the contact area and the temperature difference, so a large area and a large temperature difference are required. However, the polishing pad surface is equipped with a dresser that sharpens the top ring pad that holds the wafer, a slurry nozzle that supplies slurry, and an atomizer nozzle (high-pressure pure water shower nozzle) that cleans the pad surface. The area cannot be secured as expected.

Accordingly, a method (2) in which dry gas (air or N ₂ ) is blown onto a wet pad surface and the heat is removed by vaporization latent heat has been adopted in part. However, the sprayed dry gas may cause the slurry to scatter and reduce the slurry component effective for polishing. In addition, the scattered slurry may adhere to the periphery, and the attached slurry may drop and cause a scratch problem on the wafer surface. Thus, the conventional method (2) has high hurdles to be solved and poor versatility, and therefore has a narrow application range.

  The substrate polishing apparatus according to the present embodiment holds a substrate and presses the substrate against a polishing table for polishing, a pad cooling nozzle for cooling the polishing pad for polishing the substrate, and the vicinity of the pad cooling nozzle A local exhaust mechanism in which the intake head is disposed, and the intake head is disposed downstream of the pad cooling nozzle in the rotational direction of the polishing table.

  With this configuration, there is provided a substrate polishing apparatus (CMP apparatus) that can simultaneously collect and remove harmful gases and defect sources generated on the polishing table while simultaneously cooling the polishing pad by the pad cooling nozzle. In this case, the jet gas from the pad cooling nozzle can be locally exhausted by the local exhaust mechanism.

  In addition, the substrate polishing apparatus of the present embodiment includes a second local exhaust mechanism in which the second intake head is disposed in the vicinity of the substrate holding unit, and the second intake head polishes the substrate holding unit. You may arrange | position in the downstream of the rotation direction of a table.

  With this configuration, it is possible to exhaust harmful gases and defect sources generated in the vicinity of the substrate holding portion by the second local exhaust mechanism.

  According to the present embodiment, the problem of the conventional dry gas spraying method (2) can be solved, and the latent heat of vaporization phenomenon can be utilized. From the top ring holding the slurry / wafer spreading on the polishing pad / polishing pad surface Heat can be removed, and the temperature rise can be managed and controlled. Therefore, a good flatness of the polished surface can be obtained, and a polishing process in a temperature region that can bring out the performance of the slurry can be realized. Thereby, the productivity of the CMP apparatus can be improved.

  Next, a characteristic configuration of the substrate polishing apparatus according to the second embodiment will be described with reference to the drawings. 8 and 9 are explanatory views showing the main configuration of the substrate polishing apparatus of the present embodiment.

  As shown in FIGS. 8 and 9, the substrate polishing apparatus according to the present embodiment includes a polishing table 30 having a polishing surface 10 on an upper surface, a top ring 31 for holding a wafer W having a surface to be polished on a lower surface, and a top A local exhaust mechanism 135 is provided in the vicinity of the ring 31. The polishing surface 10 is composed of, for example, a polishing pad. The polishing table 30 is rotated in a predetermined rotation direction (clockwise in FIG. 8), and the top ring 31 has the polished surface (lower surface in FIG. 9) of the held wafer W as the polishing surface 10 of the polishing table 30. The surface to be polished of the wafer W is polished by pressing. The substrate polishing apparatus may include a table cover that covers the outside of the polishing table 30 and a top ring cover that covers the outside of the top ring 31.

  As shown in FIG. 8, a pad cooling nozzle 142 for cooling the polishing pad (polishing surface 10) is provided on the downstream side of the top ring 31. The polishing surface 10 is cooled by the injection gas (cooling gas) injected from the pad cooling nozzle 142. A local exhaust mechanism 135 is provided on the downstream side of the pad cooling nozzle 142. By this local exhaust mechanism 135, the injection gas from the pad cooling nozzle 142 can be locally exhausted.

  The intake head 136 of the local exhaust mechanism 135 is disposed on the downstream side (rotational direction side) of the polishing table 30 with respect to the pad cooling nozzle 142 (and the top ring 31). The intake head 136 includes a plurality of intake ports 137 arranged in the radial direction of the polishing table 30.

  As shown in FIG. 9, the intake port 137 of the intake head 136 is connected to the ejector 138, and intake air from the intake port 137 is performed by flowing compressed air through the ejector 138. The ejector 138 is configured to adjust the intake speed of the intake port 137 by adjusting the flow rate of the compressed air. In this case, among the plurality of intake ports 137, the intake velocity of the radially outer intake port 137 is set higher than the intake velocity of the radially inner intake port 137 (see FIG. 8). Note that the suction means from the suction port 137 is not limited to the ejector 138, and for example, a vacuum pump or the like may be used.

  The intake speed of the intake head 136 is preferably set higher than the rotational speed of the polishing table 30. In other words, the intake speed of the intake head 136 is set to 1 or more times the rotational speed of the polishing table 30 (for example, 1 to 2 m / s). For example, the intake speed of the intake head 136 is set to 1.2 to 2 times the rotational speed of the polishing table 30. The intake speed of the intake head 136 can be set based on the rotational speed of the polishing table and the reference area. The reference area is calculated from the product of the diameter of the wafer W and the reference height. The reference height may be set based on the distance between the top ring 31 and the intake head 136. For example, the reference height is set to 0.3 to 3 times the distance between the top ring 31 and the intake head 136. Further, the reference height may be set based on the height from the polishing surface 10 to the upper end of the opening of the top ring 31 (the upper end of the retainer ring gap). For example, the reference height is set to 1 to 3 times the height from the polishing surface 10 to the upper end of the opening of the top ring 31 (the upper end of the gap of the retainer ring).

  As shown in FIG. 10, the local exhaust mechanism 135 may be disposed not only on the downstream side of the top ring 31 but also in the vicinity of the top ring 31. That is, two local exhaust mechanisms 135 (a local exhaust mechanism 135 on the downstream side of the top ring 31 and a local exhaust mechanism 135 in the vicinity of the top ring 31) may be provided. In this case, the jet gas from the pad cooling nozzle 142 can be locally exhausted by the local exhaust mechanism 135 on the downstream side of the top ring 31, and the material to be polished and the slurry can be exhausted by the local exhaust mechanism 135 in the vicinity of the top ring 31. The reaction gas can be exhausted.

  The embodiments of the present invention have been described above by way of example, but the scope of the present invention is not limited to these embodiments, and can be changed or modified according to the purpose within the scope of the claims. is there.

  As described above, the substrate polishing apparatus according to the present invention has an effect that gas diffusion can be efficiently prevented in the vicinity of a place where harmful gas is generated, and is used as a chemical mechanical polishing (CMP) apparatus or the like. Useful.

DESCRIPTION OF SYMBOLS 1 Housing 2 Load / unload part 3 Polishing part 3A 1st grinding | polishing unit 3B 2nd grinding | polishing unit 3C 3rd grinding | polishing unit 3D 4th grinding | polishing unit 4 Cleaning part 5 Control part 6 1st linear transporter 7 2nd linear transporter 8 Sensor 9 Sensor 10 Polishing pad (Polished surface)
DESCRIPTION OF SYMBOLS 11 Lifter 12 Swing transporter 20 Front load part 21 Traveling mechanism 22 Transfer robot (loader)
30 (30A-30D) Polishing table 31 (31A-31D) Top ring (substrate holder)
32A to 32D Polishing liquid supply nozzle 33A to 33D Dresser 34A to 34D Atomizer 35 Local exhaust mechanism 36 Intake head 37 Intake port 38 Ejector 39 Exhaust mechanism 40 Piping 41 Gas-liquid separation mechanism TP1 First transport position TP2 Second transport position TP3 Third Transfer position TP4 Fourth transfer position TP5 Fifth transfer position TP6 Sixth transfer position TP7 Seventh transfer position 180 Temporary table 190 First cleaning chamber 191 Second cleaning chamber 192 Third cleaning chamber 193 Fourth cleaning chamber W Wafer (Substrate) )

Claims (5)

A rotating polishing table;
A substrate holding unit that holds the substrate and presses the substrate against the polishing table for polishing;
A local exhaust mechanism in which an intake head is disposed in the vicinity of the substrate holder;
With
The substrate polishing apparatus, wherein the suction head is disposed downstream of the substrate holding portion in the rotation direction of the polishing table.   The substrate polishing apparatus according to claim 1, wherein an intake speed of the intake head is set higher than a rotational speed of the polishing table. The intake head includes a plurality of intake ports arranged in the radial direction of the polishing table,
The substrate polishing apparatus according to claim 2, wherein among the plurality of intake ports, an intake speed of a radially outer intake port is set to be higher than that of a radially inner intake port. A substrate holding unit for holding the substrate and pressing the substrate against a polishing table for polishing;
A pad cooling nozzle for cooling a polishing pad for polishing the substrate;
A local exhaust mechanism in which an intake head is disposed in the vicinity of the pad cooling nozzle;
With
The substrate polishing apparatus, wherein the suction head is disposed downstream of the pad cooling nozzle in the rotation direction of the polishing table. A second local exhaust mechanism in which a second intake head is disposed in the vicinity of the substrate holder;
5. The substrate polishing apparatus according to claim 4, wherein the second intake head is disposed downstream of the substrate holding portion in the rotation direction of the polishing table.

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