JP2015208840A - Polishing device, jig for measuring abrasive pad profile, and method for measuring abrasive pad profile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure a profile of a surface shape of an abrasive pad in a short time and with a good accuracy.SOLUTION: A first polishing device includes: a polishing table 30A to which an abrasive pad 10 for polishing a polishing object is bonded; a drive part for driving rotation of the polishing table 30A; a top ring 31A which holds the polishing object and presses the object onto the abrasive pad 10; and a line laser sensor 300 which is so disposed as to face the abrasive pad 10, irradiates a surface of the abrasive pad 10 with laser beam in a line form and measures a profile of a surface shape of the abrasive pad 10 on the basis of reflection laser beam reflected from the abrasive pad 10.

Description

  The present invention relates to a polishing apparatus, a polishing pad profile measuring jig, and a polishing pad profile measuring method.

  In recent years, a substrate processing apparatus has been used to perform various processes on a substrate such as a semiconductor wafer. As an example of the substrate processing apparatus, there is a CMP (Chemical Mechanical Polishing) apparatus for polishing a substrate.

  The CMP apparatus is a polishing unit for performing a polishing process on a substrate, a cleaning unit for performing a cleaning process and a drying process on a substrate, a substrate that is transferred to the polishing unit and receives a substrate that has been cleaned and dried by the cleaning unit. Equipped with a load / unload unit.

  The polishing unit includes a plurality of polishing apparatuses arranged adjacent to each other. Each polishing apparatus holds a polishing table to which a polishing pad is attached, a driving unit that rotates the polishing table, and a polishing target (for example, a substrate such as a semiconductor wafer or various films formed on the surface of the substrate). And a top ring. The polishing apparatus polishes the polishing object by pressing the polishing object held on the top ring against the polishing pad while rotating the polishing table by the driving unit.

  By the way, a polishing pad for polishing an object to be polished is treated as a consumable item, and the polishing pad is periodically replaced. The polishing pad is replaced by, for example, a worker manually. When the polishing pad is affixed to the polishing table, it is common to manually affix the polishing pad whose back surface is an adhesive surface to the polishing table. Here, when the polishing pad is attached, an air pocket may be generated between the polishing table surface and the polishing pad back surface.

  When the protruding portion is formed on the polishing pad by the air pool, the region polished by the protruding portion is over-polished as compared with other regions, and the flatness of the object to be polished may be impaired. Therefore, after the polishing pad is pasted, it is checked whether or not an air pocket has occurred. However, it is difficult to accurately determine whether the pasted state is good or not by human touch or visual observation. On the other hand, in the prior art, it is known to detect the surface shape of the surface shape of the polishing pad using an optical sensor.

WO2005 / 072910

  The prior art does not consider measuring the profile of the surface shape of the polishing pad with high accuracy in a short time.

That is, in the conventional technique, an optical sensor for measuring the distance to the surface of the polishing pad is attached to the mover, and the distance to the surface of the polishing pad is measured while moving the mover. In the prior art, the surface shape of the polishing pad along a line passing through the vicinity of the center of the polishing pad can be measured by moving the mover.

  According to the prior art, since the distance from the polishing pad surface is measured by the sensor while moving the mover, it takes time to measure, and it may be difficult to accurately measure the profile of the surface shape of the polishing pad. is there.

  Therefore, an object of the present invention is to accurately measure the surface shape profile of the polishing pad in a short time.

  One aspect of the polishing apparatus of the present invention has been made in view of the above problems, and is disposed so as to face a polishing table to which a polishing pad for polishing a polishing object is attached, and to be opposed to the polishing pad. And a line laser sensor for irradiating the surface of the pad with a line of laser light and measuring a profile of the surface shape of the polishing pad based on the reflected laser light reflected from the polishing pad.

  The polishing apparatus may further include a drive unit that rotationally drives the polishing table, and the drive unit rotationally drives the polishing table when measuring a profile of a surface shape of the polishing pad, and the line When measuring the profile of the surface shape of the polishing pad, the laser sensor is arranged stationary on the surface of the polishing pad so as to cross the rotation direction of the polishing table, and is placed stationary against the polishing pad. Can be irradiated with laser light.

  In one embodiment of the polishing apparatus, the apparatus further includes a determination unit that determines the presence or absence of a protrusion on the surface of the polishing pad based on a profile of the surface shape of the polishing pad measured by the line laser sensor. Can do.

  In one embodiment of the polishing apparatus, the determination unit obtains an average height of the surface of the polishing pad based on a profile of a surface shape of the polishing pad, and is set in advance from the profile and the average height. The threshold value set higher by the gap is compared, and as a result of the comparison, a portion exceeding the threshold value can be determined as the protruding portion.

  One embodiment of the polishing pad profile measuring jig of the present invention is a base member that can be installed adjacent to a polishing table to which a polishing pad for polishing a polishing object is attached, and is attached to the base member. An arm member projecting from the base member to a position facing the polishing pad, and a reflected laser beam attached to the arm member and irradiating the surface of the polishing pad with a laser beam in a line and reflected from the polishing pad And a line laser sensor for measuring a profile of the surface shape of the polishing pad based on the above.

  In one embodiment of the polishing pad profile measuring jig, the arm member includes a fixed arm member fixed to the base member, and a movable arm member that can extend from the fixed arm member to a position facing the polishing pad. The line laser sensor may be provided on the movable arm member.

  In one embodiment of the polishing pad profile measuring jig, the caster member for moving the position of the base member, and the caster member is floated when measuring the profile of the surface shape of the polishing pad. And a telescopic fixed leg member for fixing the position of the base member.

  In one embodiment of the polishing pad profile measuring jig, a determination unit that determines the presence or absence of a protrusion on the surface of the polishing pad based on a profile of the surface shape of the polishing pad measured by the line laser sensor Can further be provided.

  In one embodiment of the polishing pad profile measuring jig, the determination unit obtains an average height of the surface of the polishing pad based on a profile of a surface shape of the polishing pad, and calculates the profile and the average height. It is possible to compare a threshold value set higher by a gap set in advance than that, and determine a portion that exceeds the threshold value as the protruding portion as a result of the comparison.

  Further, the polishing pad profile measuring method of the present invention is an irradiation step of irradiating the surface of the polishing pad with laser light in a line form from a line laser sensor disposed at a position facing the polishing pad for polishing a polishing object. And a measuring step of measuring a profile of the surface shape of the polishing pad based on reflected laser light reflected from the polishing pad.

  Moreover, in one form of the polishing pad profile measurement method, the irradiation step and the measurement step may be performed in a state where a polishing table to which the polishing pad is attached is rotated.

  In one embodiment of the polishing pad profile measurement method, an installation step of installing any of the above polishing pad profile measurement jigs adjacent to the polishing table, and a position where the line laser sensor faces the polishing pad A stretching step of stretching the movable arm member so as to be disposed at a position, wherein the irradiation step and the measuring step are disposed at a position where the line laser sensor faces the polishing pad by the stretching step. It may be performed in a state.

  Moreover, in one form of the polishing pad profile measurement method, after performing the installation step, the stretching step, the irradiation step, and the measurement step on the first polishing pad that is a profile measurement target, The same polishing pad profile measuring jig is used for the second polishing pad attached to the second polishing table installed adjacent to the first polishing table to which the polishing pad is attached. The installation step, the stretching step, the irradiation step, and the measurement step can be performed.

  According to this invention of this application, the profile of the surface shape of the polishing pad can be accurately measured in a short time.

FIG. 1 is a plan view showing the overall configuration of the substrate processing apparatus of the present embodiment. FIG. 2 is a perspective view schematically showing the polishing unit. FIG. 3A is a plan view showing the cleaning unit, and FIG. 3B is a side view showing the cleaning unit. FIG. 4 is a diagram showing a line laser sensor for measuring the profile of the surface shape of the polishing pad. FIG. 5 is a diagram schematically showing the protrusions formed on the polishing pad and the profile of the surface shape of the polishing pad. FIG. 6 is a perspective view of the polishing apparatus according to the first embodiment. FIG. 7 is a top view of the polishing apparatus according to the first embodiment. FIG. 8 is a diagram schematically showing the processing contents by the controller. FIG. 9 is a flowchart of a polishing pad profile measurement method for the polishing apparatus according to the first embodiment. FIG. 10 is a diagram illustrating a configuration of a polishing pad profile measuring jig according to the second embodiment. FIG. 11 is a flowchart of a polishing pad profile measurement method for the jig according to the second embodiment.

  Hereinafter, a polishing apparatus, a polishing pad profile measuring jig, and a polishing pad profile measuring method according to an embodiment of the present invention will be described with reference to the drawings. Hereinafter, a CMP apparatus will be described as an example of a substrate processing apparatus including a polishing apparatus, but the present invention is not limited to this. Hereinafter, a substrate processing apparatus including the load / unload unit 2, the polishing unit 3, and the cleaning unit 4 will be described, but the present invention is not limited to this.

  First, the configuration of the CMP apparatus will be described, and then the measurement of the profile of the surface shape of the polishing pad will be described.

<Substrate processing equipment>
FIG. 1 is a plan view showing the overall configuration of a substrate processing apparatus according to an embodiment of the present invention. As shown in FIG. 1, the CMP apparatus includes a substantially rectangular housing 1, and the inside 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. Has been. The load / unload unit 2, the polishing unit 3, and the cleaning unit 4 are assembled independently and exhausted independently. Further, the cleaning unit 4 has a control device 5 that controls the substrate processing operation.

<Load / Unload unit>
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). Here, SMIF and FOUP are sealed containers that can maintain an environment independent of the external space by accommodating a wafer cassette inside and covering with a partition wall.

  The load / unload unit 2 has a traveling mechanism 21 laid along the front load portion 20, and two transfer robots that can move along the arrangement direction of the wafer cassettes on the traveling mechanism 21. (Loader, transport mechanism) 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 up and down. The upper hand is used when returning processed wafers to the wafer cassette. The lower hand is used when a wafer before processing is taken out from the wafer cassette. In this way, the upper and lower hands can be used 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 load / unload unit 2 has a higher pressure inside the CMP apparatus, the polishing unit 3 and the cleaning unit 4 than the CMP apparatus. Always maintained. 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. Clean air from which toxic gases have been removed is constantly blowing out.

<Polishing unit>
The polishing unit 3 is a region where wafer polishing (planarization) is performed, and includes a first polishing apparatus 3A, a second polishing apparatus 3B, a third polishing apparatus 3C, and a fourth polishing apparatus 3D. These first polishing apparatus 3A, second polishing apparatus 3B, third polishing apparatus 3C, and fourth polishing apparatus 3D are arranged adjacent to each other along the longitudinal direction of the substrate processing apparatus, as shown in FIG. Yes.

  As shown in FIG. 1, the first polishing apparatus 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 (holding portion) 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 dressing of the polishing surface of the polishing pad 10 Dresser 33A, and an atomizer 34A for spraying a mixed fluid or liquid (eg, pure water) of a liquid (eg, pure water) or a liquid (eg, pure water) in the form of a mist onto the polishing surface.

  Similarly, the second polishing apparatus 3B includes a polishing table 30B, a top ring 31B, a polishing liquid supply nozzle 32B, a dresser 33B, and an atomizer 34B. The third polishing apparatus 3C includes a polishing table 30C, a top ring 31C, a polishing liquid supply nozzle 32C, a dresser 33C, and an atomizer 34C. The fourth polishing apparatus 3D includes a polishing table 30D, a top ring 31D, a polishing liquid supply nozzle 32D, a dresser 33D, and an atomizer 34D.

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

  FIG. 2 is a perspective view schematically showing the first polishing apparatus 3A. The top ring 31 </ b> A is supported by the top ring shaft 36. 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. The top ring 31 </ b> A and the polishing table 30 </ b> A are configured to rotate around their axes as indicated by arrows by a drive unit (not shown). For this reason, the gas-liquid two-phase flow containing the polishing abrasive liquid supplied to the polishing pad 10 flows outward of the polishing pad 10 by centrifugal force. 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 apparatus 3A and the second polishing apparatus 3B. The first linear transporter 6 has four transfer positions (first transfer position TP1, second transfer position TP2, and third transfer in order from the load / unload unit side) along the direction in which the polishing apparatuses 3A and 3B are arranged. 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 apparatus 3C and the fourth polishing apparatus 3D. The second linear transporter 7 has three transport positions (a fifth transport position TP5, a sixth transport position TP6, and a seventh transport in order from the load / unload unit side) along the direction in which the polishing apparatuses 3C and 3D are arranged. This is a mechanism for transporting the wafer between the positions TP7.

  The wafer is transferred to the polishing apparatuses 3A and 3B by the first linear transporter 6. The top ring 31A of the first polishing apparatus 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 apparatus 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 apparatus 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 apparatus 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 disposed 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 apparatus 3C and / or the fourth polishing apparatus 3D by the second linear transporter 7. Further, the wafer polished by the polishing unit 3 is conveyed to the cleaning unit 4 via the swing transporter 12.

<Washing unit>
FIG. 3A is a plan view showing the cleaning unit 4, and FIG. 3B is a side view showing the cleaning unit 4. 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 the 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. These upper drying module 205A and 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 placement 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 (transfer mechanism) 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.

<Measurement of polishing pad profile>
Next, measurement of the profile of the surface shape of the polishing pad will be described. First, the outline of the line laser sensor used in this embodiment will be described. FIG. 4 is a diagram showing a line laser sensor for measuring the profile of the surface shape of the polishing pad. FIG. 5 is a diagram schematically showing the protrusions formed on the polishing pad and the profile of the surface shape of the polishing pad.

  As shown in FIG. 4, the line laser sensor 300 is disposed to face the polishing pad 10. The line laser sensor 300 irradiates the surface of the polishing pad 10 with laser light 310 in a line shape. For example, the line laser sensor 300 spreads laser light emitted from a laser light source such as a semiconductor laser in a band shape by a lens in the line laser sensor 300 and irradiates the surface of the polishing pad 10 with the laser light 310 spread in the band shape. As a result, an irradiation line 312 is formed on the portion of the polishing pad 10 where the laser beam 310 is irradiated. The line laser sensor 300 measures the profile of the surface shape of the polishing pad 10 based on the reflected laser light 315 reflected from the polishing pad 10. Further, the line laser sensor 300 can measure the profile of the surface shape of the polishing pad 10 as a whole by measuring the profile of the surface shape of the polishing pad 10 while the polishing table is rotationally driven.

Here, the polishing pad 10 is treated as a consumable item, and the polishing pad 10 is periodically replaced. The polishing pad 10 is replaced by, for example, a worker's hand. When the polishing pad 10 is affixed to the polishing table, it is common to manually affix the polishing pad whose back surface is an adhesive surface to the polishing table. When the polishing pad 10 is attached, an air pool may be generated between the front surface of the polishing table 30 </ b> A and the back surface of the polishing pad 10.

  Then, as shown in FIG. 5, an air pool is generated in the polishing pad 10, and a protrusion α is formed in the polishing pad 10 by the air pool. In the profile 314 of the surface shape of the polishing pad 10 in the irradiation line 312, as shown in FIG. 5, the protrusion β appears at a portion corresponding to the protrusion α. In the following description, an example in which the profile of the surface shape is measured in order to determine the presence or absence of the protrusion due to the air accumulation in the polishing pad 10 will be described, but the present invention is not limited to this. That is, the polishing pad 10 is required to have various surface shapes in order to polish the polishing surface of the object to be polished into a desired shape. Therefore, it is possible to determine whether or not the polishing pad 10 has a desired surface shape by using the measurement according to the present embodiment.

<First Embodiment>
Next, the polishing apparatus as the first embodiment will be described. FIG. 6 is a perspective view of the polishing apparatus according to the first embodiment. FIG. 7 is a top view of the polishing apparatus according to the first embodiment. 6 and 7 illustrate the first polishing apparatus 3A as an example, but the second polishing apparatus 3B, the third polishing apparatus 3C, and the fourth polishing apparatus 3D can have the same configuration.

  As shown in FIGS. 6 and 7, the first embodiment is an embodiment in which a line laser sensor 300 is fixedly arranged in the first polishing apparatus 3A. As described above, the first polishing apparatus 3A includes the polishing table 30A to which the polishing pad 10 is attached, the drive unit that rotationally drives the polishing table 30A, and the top ring 31A that holds the object to be polished and presses it against the polishing pad 10. And a line laser sensor 300 disposed to face the polishing pad 10.

  In the present embodiment, the first polishing apparatus 3 </ b> A includes two line laser sensors 300. For example, as shown in FIG. 4, the irradiation line 312 formed by one line laser sensor 300 intersects the rotation direction of the polishing table 30A and extends from the center of the polishing pad 10 in the radial direction. Until it is not stretched. Then, when the profile of the surface shape of the polishing pad 10 is measured while rotating the polishing table 30A, the profile of the outer peripheral region of the polishing pad 10 cannot be obtained.

  Therefore, in the present embodiment, by arranging two line laser sensors 300 side by side, the profile of the surface shape of the entire region of the polishing pad 10 can be measured. Each of the two line laser sensors 300 is fixed to a sensor fixture 320 arranged at the top of the first polishing apparatus 3A. Accordingly, the line laser sensor 300 is disposed so as to be opposed to the polishing pad 10 when measuring the profile of the surface shape of the polishing pad 10. The number of line laser sensors 300 is arbitrary. For example, if the profile of the surface shape of the entire region of the polishing pad 10 can be measured by one line laser sensor 300, one line laser sensor 300 may be provided.

  Further, the first polishing apparatus 3A includes a controller (determination unit) not shown. The controller determines the presence or absence of a protrusion on the surface of the polishing pad 10 based on the profile of the surface shape of the polishing pad 10 measured by the line laser sensor 300. Specifically, the controller obtains the average height of the surface of the polishing pad 10 based on the profile of the surface shape of the polishing pad 10 and exceeds a threshold set higher by a gap set in advance than the average height. A high part is determined as a protrusion.

FIG. 8 is a diagram schematically showing the processing contents by the controller. As shown in FIG. 8, the controller obtains the average height 316 of the entire surface of the polishing pad 10 based on the profile 314 measured by the line laser sensor 300. In addition, the controller compares the profile 314 with a threshold value 318 set higher than the average height 316 by a preset gap γ. For example, the gap γ can be set to about 0.5 mm. As a result of the comparison, the controller determines a portion exceeding the threshold value 318 as a protruding portion. When the controller determines that there is a protruding portion (error), the controller notifies the worker by outputting it to a display interface such as a PC connected to the controller or outputting a warning sound.

  If the controller determines that there is a protrusion (error), the controller can output information specifying which part of the polishing pad 10 is a protrusion to a display interface such as a PC. That is, the controller determines that the protrusion (error) in the profile 314 is based on the profile 314 measured by the line laser sensor 300, the position where measurement of the polishing pad 10 is started, and the rotational speed of the polishing table 30A. It can be determined which of 10 locations corresponds. The controller can output the obtained location information to a display interface such as a PC. This allows the worker to quickly identify where the error occurred.

  Next, a polishing pad profile measurement method for the polishing apparatus according to the first embodiment will be described. FIG. 9 is a flowchart of a polishing pad profile measurement method for the polishing apparatus according to the first embodiment.

  The polishing apparatus 3A of the first embodiment has a line laser sensor 300 built therein. Therefore, in the profile measuring method, first, the polishing table 30A is rotated (step S101). Specifically, in the profile measurement method, the polishing table 30A is rotated by driving the drive unit.

  Subsequently, in the profile measurement method, the surface of the polishing pad 10 is irradiated with laser light in a line form from the line laser sensor 300 disposed at a position facing the polishing pad (step S102, irradiation process).

  Subsequently, in the profile measurement method, the reflected laser beam reflected from the polishing pad 10 is received (step S103), and the profile of the surface shape of the polishing pad 10 is measured based on the received reflected laser beam (step S104, measurement process). ). The irradiation process and the measurement process are performed in a state where the polishing table to which the polishing pad 10 is attached is rotated.

  Subsequently, the profile measuring method determines whether or not the polishing pad 10 has a protruding portion based on the measured profile (step S105). Specifically, in the profile measurement method, the average height of the entire surface of the polishing pad 10 is obtained based on the measured profile, a threshold value is obtained based on the average height, the profile and the threshold value are compared, and the threshold value is obtained. A portion that exceeds the height is determined as a protruding portion.

  When it is determined that the polishing pad 10 has no protrusion (No in step S105), the profile measurement method ends the process. On the other hand, if the profile measurement method determines that the polishing pad 10 has a protruding portion (step S105, Yes), the fact (error) is output to a display interface such as a PC connected to the controller, or Alternatively, a warning sound is output (step S106), and the process ends.

According to this embodiment, the profile of the surface shape of the polishing pad 10 can be accurately measured in a short time. That is, in the conventional technique, an optical sensor that measures the distance to the polishing pad surface is attached to the mover, and the distance from the polishing pad surface is measured while moving the mover, thereby passing near the center of the polishing pad. Measure the surface shape of the polishing pad along the line. According to the prior art, since the distance from the polishing pad surface is measured by the sensor while moving the mover, it takes time to measure, and it may be difficult to accurately measure the profile of the surface shape of the polishing pad. is there.

  On the other hand, in the present embodiment, a line for measuring the profile of the surface shape of the polishing pad 10 based on the reflected laser beam 315 reflected from the polishing pad 10 by irradiating the surface of the polishing pad 10 with the laser beam 310 in a line shape. A laser sensor 300 is used. Further, the line laser sensor 300 can measure the profile of the entire surface shape of the polishing pad 10 while rotating the polishing table 30 </ b> A while standing still facing the polishing pad 10. Therefore, according to the present embodiment, the profile of the surface shape of the polishing pad 10 can be accurately measured in a short time. Even when measuring the surface shape of the polishing pad to dress the surface shape of the polishing pad roughened by polishing, which is the purpose of the prior art, the present invention can grasp the entire surface shape in a very short time, By calculating the difference between each point on the profile of the shape and the threshold value, it is possible to grasp two-dimensionally the place where dressing should be focused.

Second Embodiment
Next, a polishing pad profile measuring jig as a second embodiment will be described. FIG. 10 is a diagram illustrating a configuration of a polishing pad profile measuring jig according to the second embodiment.

  In the first embodiment, the line laser sensor 300 is fixedly disposed inside the polishing apparatus 3A. However, in the second embodiment, the line laser sensor 300 measures the profile of the surface shape of the polishing pad 10. Mounted on the jig 400.

  As shown in FIG. 10, the jig 400 includes a base member 410, a fixed arm member 460 fixed to the base member 410, and a movable arm member 470 that can be extended from the fixed arm member 460 to a position facing the polishing pad 10. And a line laser sensor 300 provided on the movable arm member 470. The fixed arm member 460 and the movable arm member 470 are arm members that protrude from the base member 410 to a position facing the polishing pad 10.

  Similar to the first embodiment, the line laser sensor 300 irradiates the surface of the polishing pad 10 with laser light in a line shape and obtains a profile of the surface shape of the polishing pad 10 based on the reflected laser light reflected from the polishing pad 10. It is a line laser sensor to measure.

  The base member 410 is a member such as a frame rack. The base member 410 includes shelf plates 420 and 430 arranged in two upper and lower stages for mounting various members, and a side plate 425 that covers the side surface of the base member 410. For example, a PC for an operator to perform profile measurement can be installed on the shelf plate 420. Further, the controller 330 described in the first embodiment is disposed on the side plate 425. The controller 330 may be supplied with power from, for example, a CMP apparatus. The controller 330 may use another power source in the facility where the CMP apparatus is installed.

That is, the controller 330 determines the presence or absence of a protrusion on the surface of the polishing pad 10 based on the profile of the surface shape of the polishing pad 10 measured by the line laser sensor 300. Specifically, the controller 330 obtains the average height 316 of the entire surface of the polishing pad 10 based on the profile 314 measured by the line laser sensor 300. In addition, the controller 330 compares the profile 314 with a threshold value 318 set higher than the average height 316 by a preset gap γ. As a result of the comparison, the controller 330 determines a portion that exceeds the threshold 318 as a protruding portion. When the controller 330 determines that there is a protruding portion, the controller 330 notifies the worker by outputting it to the display interface of the PC connected to the controller 330 or outputting a warning sound.

  Further, as shown in FIG. 10, the base member 410 floats the caster member 440 for moving the position of the base member 410 and the caster member 440 when measuring the profile of the surface shape of the polishing pad 10. And a telescopic fixed leg member 450 for fixing the position of the base member 410.

  Due to the presence of the caster member 440, the base member 410 is movable. For this reason, the base member 410 can be installed adjacent to the polishing table 30A (polishing apparatus).

  When measuring the profile of the surface shape of the polishing pad 10 in the polishing apparatus 3A, the jig 400 is moved to a position adjacent to the polishing apparatus 3A using the caster member 440. Subsequently, the caster member 440 is floated by extending the fixed leg member 450, and the position of the jig 400 is fixed. Subsequently, the line laser sensor 300 is disposed at a position facing the polishing pad 10 by opening the door of the polishing apparatus 3 </ b> A and extending the movable arm member 470. Then, the profile of the surface shape of the polishing pad 10 is measured using the line laser sensor 300 while rotating the polishing table 30A.

  Next, a polishing pad profile measuring method for the jig of the second embodiment will be described. FIG. 11 is a flowchart of a polishing pad profile measurement method for the jig according to the second embodiment.

  First, in the profile measurement method, the jig 400 is installed adjacent to a polishing apparatus (for example, the first polishing apparatus 3A) to be profiled (step S201, installation process). Specifically, in the profile measurement method, the jig 400 is moved using the caster member 440 of the jig 400. Thereafter, in the profile measurement method, the caster member 440 is lifted by extending the fixed leg member 450 and the position of the jig 400 is fixed, so that the jig 400 is subjected to a profile measurement target polishing apparatus (for example, the first polishing apparatus 3A). Install next to

  Subsequently, in the profile measuring method, the window of the polishing apparatus is opened and the movable arm member 470 is stretched (step S202, stretching step). Specifically, in the profile measurement method, the movable arm member 470 is extended so that the line laser sensor 300 is disposed at a position facing the polishing pad 10.

  Subsequently, in the profile measurement method, the polishing table 30A is rotated (step S203). Specifically, in the profile measurement method, the polishing table 30A is rotated by driving the drive unit.

  Subsequently, the profile measurement method irradiates the surface of the polishing pad 10 with a laser beam in a line form from the line laser sensor 300 disposed at a position facing the polishing pad 10 (step S204, irradiation process).

  Subsequently, the profile measurement method receives the reflected laser beam reflected from the polishing pad 10 (step S205), and measures the profile of the surface shape of the polishing pad 10 based on the received reflected laser beam (step S206, measurement process). ).

Subsequently, in the profile measuring method, the polishing pad 10 is based on the measured profile.
It is determined whether or not there is a protruding portion (step S207). Specifically, in the profile measurement method, the average height of the entire surface of the polishing pad 10 is obtained based on the measured profile, a threshold value is obtained based on the average height, the profile and the threshold value are compared, and the threshold value is obtained. A portion that exceeds the height is determined as a protruding portion.

  If it is determined that the polishing pad 10 has no protrusion (No in step S207), the profile measurement method proceeds to step S209. On the other hand, if the profile measurement method determines that the polishing pad 10 has a protruding portion (step S207, Yes), the fact (error) is output to a display interface such as a PC connected to the controller, Alternatively, a warning sound is output (step S208), and the process proceeds to step S209.

  Subsequently, in the profile measurement method, it is determined whether or not there is another polishing apparatus as a profile measurement target (step S209). When it is determined that there is another polishing apparatus for profile measurement (step S209, Yes), the profile measurement method returns to step S201 and repeats the process. That is, after the installation process, the stretching process, the irradiation process, and the measurement process are performed on the first polishing pad (for example, the polishing pad 10 of the first polishing apparatus 3A) that is a profile measurement target, the first polishing is performed. A second polishing pad (for example, second polishing pad) attached to a second polishing table (for example, polishing table 30B) installed adjacent to the first polishing table (for example, polishing table 30A) to which the pad is attached. The installation process, the stretching process, the irradiation process, and the measurement process are performed on the polishing pad 10) of the apparatus 3B using the same jig 400. On the other hand, in the profile measurement method, when it is determined that there is no other polishing apparatus as a profile measurement target (No in step S209), the process ends.

  According to the present embodiment, as in the first embodiment, the profile of the surface shape of the polishing pad 10 can be accurately measured in a short time. In addition, in this embodiment, since the jig 400 is used, the line laser sensor 300 does not have to be fixedly arranged inside the polishing apparatus. For this reason, in this embodiment, a large working space for workers inside the polishing apparatus can be secured. Further, according to the present embodiment, the line laser sensor 300 is not fixedly disposed in each polishing apparatus, but a single jig 400 is used and a polishing pad in a plurality of polishing apparatuses is used. Profiles can be measured. As a result, it is not necessary to provide a large number of line laser sensors 300, so that the cost can be reduced.

3A, 3B, 3C, 3D Polishing device 10 Polishing pads 30A, 30B, 30C, 30D Polishing tables 31A, 31B, 31C, 31D Top ring 300 Line laser sensor 310 Laser beam 312 Irradiation line 314 Polishing pad surface shape profile 315 Reflection Laser beam 318 Threshold 320 Sensor fixture 330 Controller 400 Jig 410 Base member 420, 430 Shelf plate 425 Side plate 440 Caster member 450 Fixed leg member 460 Fixed arm member 470 Movable arm member W Wafer α Protruding portion β Protruding portion γ Gap

Claims (13)

A polishing table to which a polishing pad for polishing a polishing object is attached;
A line laser that is disposed opposite to the polishing pad, irradiates the surface of the polishing pad with a laser beam in a line shape, and measures the profile of the surface shape of the polishing pad based on the reflected laser beam reflected from the polishing pad A sensor,
A polishing apparatus comprising: The polishing apparatus according to claim 1, wherein
A drive unit that rotationally drives the polishing table;
The drive unit rotationally drives the polishing table when measuring the profile of the surface shape of the polishing pad,
When measuring the profile of the surface shape of the polishing pad, the line laser sensor is disposed so as to be opposed to the polishing pad and is placed on the surface of the polishing pad so as to intersect the rotation direction of the polishing table. Irradiate laser light in a line shape,
A polishing apparatus characterized by that. The polishing apparatus according to claim 1 or 2,
A determination unit for determining the presence or absence of protrusions on the surface of the polishing pad based on a profile of the surface shape of the polishing pad measured by the line laser sensor;
A polishing apparatus characterized by that. The polishing apparatus according to claim 3, wherein
The determination unit obtains the average height of the surface of the polishing pad based on the profile of the surface shape of the polishing pad, and the profile and a threshold set higher than the average height by a preset gap. , And, as a result of the comparison, a portion that is higher than the threshold is determined as the protruding portion,
A polishing apparatus characterized by that. A base member that can be installed adjacent to a polishing table to which a polishing pad for polishing a polishing object is attached;
An arm member attached to the base member and projecting from the base member to a position facing the polishing pad;
A line laser sensor that is attached to the arm member, irradiates the surface of the polishing pad with laser light in a line shape, and measures a profile of the surface shape of the polishing pad based on reflected laser light reflected from the polishing pad;
A polishing pad profile measuring jig comprising: In the polishing pad profile measuring jig according to claim 5,
The arm member is
A fixed arm member fixed to the base member;
A movable arm member that can be extended from the fixed arm member to a position facing the polishing pad,
The line laser sensor is provided on the movable arm member.
A polishing pad profile measuring jig characterized by the above. In the polishing pad profile measuring jig according to claim 5 or 6,
A caster member for moving the position of the base member;
A stretchable fixing leg member for fixing the position of the base member by floating the caster member when measuring the profile of the surface shape of the polishing pad;
A polishing pad profile measuring jig, further comprising: In the polishing pad profile measuring jig according to any one of claims 5 to 7,
A determination unit for determining the presence or absence of protrusions on the surface of the polishing pad based on a profile of the surface shape of the polishing pad measured by the line laser sensor;
A polishing pad profile measuring jig characterized by the above. The polishing pad profile measuring jig according to claim 8,
The determination unit obtains the average height of the surface of the polishing pad based on the profile of the surface shape of the polishing pad, and the profile and a threshold set higher than the average height by a preset gap. , And, as a result of the comparison, a portion that is higher than the threshold is determined as the protruding portion,
A polishing pad profile measuring jig characterized by the above. An irradiation step of irradiating the surface of the polishing pad with a laser beam in a line form from a line laser sensor disposed at a position facing the polishing pad for polishing a polishing object;
A measuring step of measuring a profile of the surface shape of the polishing pad based on reflected laser light reflected from the polishing pad;
A polishing pad profile measuring method comprising: In the polishing pad profile measuring method of Claim 10,
The irradiation step and the measurement step are performed in a state where a polishing table to which the polishing pad is attached is rotated.
A polishing pad profile measuring method characterized by the above. In the polishing pad profile measuring method of Claim 11,
An installation step of installing the polishing pad profile measuring jig according to any one of claims 6 to 9 adjacent to the polishing table;
An extending step of extending the movable arm member so that the line laser sensor is disposed at a position facing the polishing pad;
Further comprising
The irradiation step and the measurement step are performed in a state where the line laser sensor is disposed at a position facing the polishing pad by the stretching step.
A polishing pad profile measuring method characterized by the above. The polishing pad profile measuring method according to claim 12,
First polishing in which the first polishing pad is attached after the installation step, the stretching step, the irradiation step, and the measurement step are performed on the first polishing pad that is a profile measurement target. Using the same polishing pad profile measuring jig for the second polishing pad attached to the second polishing table installed adjacent to the table, the installation step, the stretching step, and the irradiation step And performing the measurement step,
A polishing pad profile measuring method characterized by the above.

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