Method of manufacture including polishing pad monitoring method and polishing apparatus including polishing pad monitoring device

In a method of manufacture, a displacement sensor is provided over a conditioner disk. The conditioner disk is rotated to perform a conditioning process on a polishing surface of a polishing pad. A displacement of the rotating conditioner disk is detected using the displacement sensor during the conditioning process. A height of the conditioner disk is calculated from the detected displacement. An end point of the conditioning process is determined on the polishing surface based on the calculated height.

PRIORITY STATEMENT

This application claims priority under 35 U.S.C. § 119 to Korean Patent Application No. 10-2018-0137886, filed on Nov. 12, 2018 in the Korean Intellectual Property Office (KIPO), the contents of which are herein incorporated by reference in their entirety.

BACKGROUND

Example embodiments relate to a polishing pad monitoring method, a polishing pad monitoring apparatus, a polishing apparatus including the pad monitoring apparatus, and a method of manufacturing a semiconductor device using the polishing apparatus. More particularly, example embodiments relate to a polishing pad monitoring method of monitoring a conditioning process on a polishing pad and a polishing pad monitoring apparatus for performing the same.

2. Description of the Related Art

In a chemical mechanical polishing process, a conditioner disk may be rotated to condition a polishing surface of a polishing pad, to thereby maintain a polishing performance. In order to monitor the conditioning process on the polishing pad, it may be beneficial to obtain a profile of the polishing pad (e.g., a cross-sectional profile/shape of the polishing surface). However, because a movement of a conditioner disk is not monitored, a precise profile of the polishing pad may not be obtained, and thus, it may be difficult to precisely analyze the polishing pad conditioning process and to determine whether a polishing pad conditioner is in proper condition.

SUMMARY

Example embodiments provide a polishing pad monitoring method capable of obtaining a precise profile of a polishing pad, precisely analyzing a polishing pad conditioning process and diagnosing a failure in a polishing pad conditioner.

Example embodiments provide a polishing pad monitoring apparatus for performing the polishing pad monitoring method. Example embodiments also provides a method of manufacture semiconductor devices using the monitoring apparatus and/or the monitoring method.

According to example embodiments, in a method of manufacture, a displacement sensor is provided over a conditioner disk. The conditioner disk is rotated to perform a conditioning process on a polishing surface of a polishing pad. A displacement of the rotating conditioner disk is detected using the displacement sensor during the conditioning process. A height of the conditioner disk is calculated from the detected displacement. An end point of the conditioning process is determined on the polishing surface based on the calculated height.

According to example embodiments, in a method of manufacture, a conditioner disk is rotated to perform a conditioning process on a polishing surface of a polishing pad. A displacement of the rotating conditioner disk is detected using a non-contacting displacement sensor which is arranged to face an upper surface of the conditioner disk during the conditioning process. A height of the conditioner disk is calculated from the detected displacement. A height of the polishing pad or a failure of a polishing pad conditioner including the conditioner disk is determined based on the calculated height.

According to example embodiments, a polishing apparatus includes a polishing pad conditioner including a conditioner disk which is rotatable and configured to condition a polishing surface of a polishing pad, a non-contacting displacement sensor arranged to face an upper surface of the conditioner disk and configured to detect a displacement of the conditioner disk while the conditioner disk rotates, and a data processor configured to calculate a height of the conditioner disk from displacement detected by the non-contacting displacement sensor and configured to determine a height of the polishing pad or a failure of the polishing pad conditioner including the conditioner disk.

According to example embodiments, a displacement of a rotating conditioner disk may be detected using an eddy current sensor installed in a disk head, and a height of a polishing pad and a failure and replacement time of parts in a polishing pad conditioner may be determined.

Accordingly, since a precise profile of the polishing pad is obtained while a polishing pad conditioning process is performed, the polishing pad conditioning process may be analyzed precisely, and fault diagnosis for movement balance (sweep, rotation) maintenance of the conditioner disk may be performed easily.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

FIG. 1is a perspective view illustrating a chemical mechanical polishing apparatus in accordance with example embodiments.FIG. 2is a perspective view illustrating a polishing pad of the chemical mechanical polishing apparatus inFIG. 1.FIG. 3is a plan view illustrating a relative position between the polishing pad and a polishing pad conditioner of the chemical mechanical polishing apparatus inFIG. 1.FIG. 4is a block diagram illustrating a monitoring apparatus of the polishing pad inFIG. 2.FIG. 5is a side view illustrating the polishing pad conditioner and an eddy current sensor inFIG. 4.FIG. 6is a perspective view illustrating the polishing pad conditioner and the eddy current sensor inFIG. 4.FIG. 7is a perspective view illustrating the eddy current sensors installed in a disk head of the polishing pad conditioner inFIG. 6.FIGS. 8 to 10are perspective views in which indexing structures are provided in an upper surface of a disk of the polishing pad conditioner in accordance with example embodiments.

Referring toFIGS. 1 to 10, a chemical mechanical polishing (CMP) apparatus10may include a polishing table20having a polishing pad30thereon, a polishing carrier apparatus40having a polishing head42for holding a substrate such as a wafer W, a slurry dispenser50configured to dispense a slurry onto the polishing pad30to be used for a chemical mechanical polishing process, a polishing pad conditioner100configured to condition a polishing surface32of the polishing pad30, and a polishing pad monitoring apparatus/device configured to monitor the polishing pad conditioner100so as to maintain a polishing performance of the polishing pad30.

The wafer may refer to a substrate formed of a semiconductor or non-semiconductor material. The wafer may include one or more layers formed on the substrate. For example, such layers may include, but are not limited to, a resist, a dielectric material or a conductive material. For example, the wafer may include portions to be diced into a plurality of dies, each having a repeatable pattern features.

The polishing table20may be rotatable and may have a disk shape on which the polishing pad30is positioned. The polishing table20may be operable to rotate about its own axis23. The polishing table20may rotate the polishing pad30at a desired speed in order to polish the substrate such as the wafer. For example, the CMP apparatus may include a motor (not illustrated) that may rotate a driving shaft22connected to the polishing table20thereby rotating the polishing table20.

The polishing pad30may include abrasive particles formed thereon to polish the substrate. The polishing pad30may include an elastomeric material having a rough surface such as polyurethane. The polishing pad30may also be rotated by the polishing table20.

The polishing head42may hold the substrate and press the substrate down for a surface of the substrate to be in contact with the polishing pad30and to be polished against the polishing pad30. The polishing head42may be connected to and combined with a drive shaft of the polishing carrier apparatus40to move on the polishing pad30while rotating. The polishing head42may include a retainer ring and may hold the substrate such as the wafer W under a flexible membrane.

The slurry dispenser50may dispense the slurry onto the polishing pad30through a slurry dispensing nozzle. The slurry may be used to perform the chemical mechanical polishing process. The slurry may be used to chemically and/or mechanically planarize the wafer.

The polishing head42and the polishing table20may rotate in respective directions as illustrated by arrows inFIG. 1. In this state, the polishing head42may hold and pressurize the wafer W against the polishing pad30, and the slurry dispenser50may supply the slurry as a polishing material onto the polishing pad30. For example, the slurry may be a watery mixture of an insoluble matter. For example, the slurry may be a mixture of a liquid and a solid power. The wafer W and the polishing pad30may be brought into sliding contact with each other in the presence of the polishing material, whereby a surface of the wafer W is polished. For example, the wafer W and the polishing pad30may contact each other and may slide against each other. The slurry may be sandwiched between the wafer W and the polishing pad30while the wafer W and the polishing pad30slide against each other.

When the polishing pad30is worn by friction between the polishing pad30and the wafer, the polishing pad conditioner100may be provided to reduce the abrasion of the polishing pad30. The pad conditioner100may regenerate the rough surface of the polishing pad30to maintain acceptable and consistent removal rates. A conditioner disk120of the polishing pad conditioner100may be brought into sliding contact with the polishing surface32of the polishing pad30. For example, the conditioner disk120may be in contact with the polishing surface32, and the conditioner disk120may slide against the polishing surface32of the polishing pad30while the pad conditioner100regenerates the rough surface of the polishing pad30. Accordingly, the polishing pad30may be used for an extended time without being replaced.

The CMP apparatus may include elements substantially the same as or similar to a conventional CMP apparatus except for the polishing pad conditioner and the polishing pad monitoring apparatus. Hereinafter, the polishing pad conditioner and the polishing pad monitoring apparatus will be explained in detail.

In example embodiments, the polishing pad conditioner100may perform a conditioning process on the polishing surface32of the polishing pad30, and the polishing pad monitoring apparatus may monitor the polishing pad conditioner100to diagnose an abrasion amount and an abrasion state of the polishing pad30and a failure of the polishing pad conditioner100.

The polishing pad conditioner100may include the conditioner disk120to be brought into sliding contact (e.g., contact and slide) with the polishing surface32of the polishing pad30and a disk head110to rotatably support a disk shaft130connected to the conditioner disk120. For example, the disk head110may be connected on one end of the disk shaft130and the conditioner disk120may be connected to the other end of the disk shaft130. The polishing pad conditioner100may include a conditioner arm support shaft104and a conditioner arm102rotating about the central axis of the conditioner arm support shaft104. The disk head110may be installed in a distal end portion of the conditioner arm102. For example, the conditioner arm support shaft104may be connected on one end of the conditioner arm102and the disk head110may be connected on the other end of the conditioner arm102.

The disk shaft130may be rotated by a motor (not illustrated) installed/disposed in the disk head110or the conditioner arm102. The conditioner disk120secured to the disk shaft130may be rotated by the rotation of the disk shaft130.

The disk head110or the conditioner arm102may include a pneumatic cylinder (not illustrated) for elevating the disk shaft130. The pneumatic cylinder may be an actuator for enabling the conditioner disk120to exert a load on the polishing pad30. The load may be regulated by a pneumatic pressure supplied to the pneumatic cylinder. The pneumatic cylinder may press the conditioner disk120through the disk shaft130against the polishing surface32of the polishing pad30with a predetermined load.

The conditioner disk120may include a disk cover122, a disk body124and a lower disk126. The lower disk126may have a lower surface to which diamond particles are fixed. The disk body124may be connected to the disk shaft130to rotate therewith. The disk cover122may include indexing structures which are arranged at equal angle interval about a disk center, as described later.

The disk head110may have a shape corresponding to the conditioner disk120. A size of the disk head110may be substantially the same as or less than a size of the conditioner disk120. For example, the disk head110may have a diameter the same as or less than the diameter of the conditioner disk120in a plan view. For example, the disk head110may have a diameter of about 50 mm to about 200 mm. The disk head110and the conditioner disk120may include a metal material such as aluminum, stainless steel, etc.

The conditioning process of the polishing surface32of the polishing pad30may be performed as follows. The polishing table20and the polishing pad30may be rotated by the rotation of the driving shaft22. In this state, a dressing liquid may be supplied onto the polishing surface32of the polishing pad30. For example, the dressing liquid may be deionized water or a chemical liquid. The conditioner disk120may rotate about its own axis. The conditioner disk120may be pressed against the polishing surface32by the pneumatic cylinder to bring a lower surface of the conditioner disk120into sliding contact with the polishing surface32. The conditioner arm102may swing over the polishing pad30for the conditioner disk120to move (swing) on the polishing pad30in a substantially radial direction of the polishing pad30. For example, the conditioner disk120may move on the polishing pad30from the center of the polishing pad30toward an edge of the polishing pad30while the polishing pad30is rotating along with the polishing table20. In certain embodiments, the conditioner disk120may also move on the polishing pad30from an edge of the polishing pad30toward the center of the polishing pad30while the polishing pad30is rotating along with the polishing table20. The rotating conditioner disk120may regenerate the polishing surface32of the polishing pad30to provide an even polishing surface. For example, the rotating conditioner disk120may condition the polishing surface32of the polishing pad30to be flat, thereby allowing for the polishing pad30to be reused to polish wafers.

The chemical mechanical polishing apparatus may include a table rotary encoder to detect a rotation angle of the polishing table20and the polishing pad30and a conditioner arm rotary encoder to detect a swing angle of the conditioner arm102. For example, the rotary encoders may be on-axis magnetic encoders, off-axis magnetic encoders or optical encoders.

As illustrated inFIG. 3, x-y coordinate system is a stationary coordinate system defined on a base of the polishing apparatus and X-Y coordinate system is a rotating coordinate system defined on the polishing surface32of the polishing pad30. The polishing pad30may rotate about an origin O of the x-y coordinate system, while the conditioner disk120may swing at a predetermined angle about a predetermined point C on the x-y coordinate system. The position of the point C may correspond to a central axis position of the conditioner arm support shaft104inFIG. 1.

Coordinates of the center of the conditioner disk120on the x-y stationary coordinate system may be determined from coordinates of the point C, a distance R and an angle θ. Coordinates of the center of the condition disk120on the X-Y rotating coordinate system may be determined from the coordinates of the center of the conditioner disk120on the x-y stationary coordinate system and a rotation angle α of the polishing pad30. Conversion of the coordinates on the stationary coordinate system into the coordinates on the rotating coordinate system may be carried out by using known trigonometric functions and four arithmetic operations.

The X-Y rotating coordinate system may be a two-dimensional surface defined on the polishing surface32. For example, the coordinates of the conditioner disk120on the X-Y rotating coordinate system may indicate a relative position of the conditioner disk120with respect to the polishing surface32. In this manner, the position of the conditioner disk120may be expressed as the position on the two-dimensional surface defined on the polishing surface32.

The polishing pad monitoring apparatus may include a non-contacting sensor such as an eddy current sensor200and a data processor300. The non-contact sensor may detect a displacement of the conditioner disk120. The polishing pad monitoring apparatus may further include a controller400for controlling operations of the conditioner disk120according to results calculated in the data processor300.

The non-contacting sensor such as the eddy current sensor200may be installed to face the upper surface of the conditioner disk120, to detect the displacement of the conditioner disk120. For example, the non-contacting sensor may detect a distance of the conditioner disk120from the non-contacting sensor. For example, the non-contacting sensor may detect a deviation from a predetermined position of the conditioner disk120. For example, the non-contacting sensor may include an eddy current sensor200. The eddy current sensor200may detect a height of the upper surface of the conditioner disk120which is rotating while contacting the polishing surface32of the polishing pad30. The eddy current sensor200may transmit an output signal (e.g., the height value of the conditioner disk120) to the data processor300each time the eddy current sensor200detects the height of the upper surface of the conditioner disk120.

As illustrated inFIG. 7, one or more eddy current sensors200may be installed in the disk head110. For example, four eddy current sensors200may be installed at equal angle interval about the center of the disk head110to be spaced apart from each other. The conditioner disk120may have a gimbal structure. When the conditioner disk120having a gimbal structure swings or rotates, a plurality of the eddy current sensors200may be provided to precisely detect position information of the conditioner disk120. For example, the position of the disk may be detected by obtaining the position of lines or a surface from the sensing values of a plurality of the eddy current sensors200. The eddy current sensor200may be installed in a lower surface of the disk head110. The eddy current sensor200may be installed in a seating portion112such as a slot or a recess formed in the lower surface of the disk head110. A cover member114may cover the eddy current sensor200to protect from the surrounding environment. For example, the cover member114may be a cover made of a metal or a ceramic.

Alternatively, when the size of the disk head110is less than the size of the conditioner disk120, the eddy current sensor200may be installed in a lower surface of the conditioner arm102outside the disk head110to face the upper surface of the conditioner disk120.

As illustrated inFIGS. 8 to 10, the conditioner disk120may include the indexing structures121a-121gwhich may be arranged at equal angle interval about a disk center in the upper surface thereof. Indexing structure(s)121may collectively represent indexing structures121athrough121g, or an arbitrary one of the indexing structures121a-121gthroughout the present disclosure including the drawings. As described later, the indexing structures may be used to calculate a rotational speed (rpm) and a rotational angular displacement of the conditioner disk120and to provide singular points for converting into a two-dimensional plane profile having a constant height during a rotation period of the condition disk120. For example, the sensor may be configured to detect distances and/or positions of portions of the conditioner disk120on the basis of the positions of the indexing structures.

The conditioner disk120inFIG. 8may include first, second and third indexing grooves121a,121b, and121c. The first to third indexing grooves121a,121b, and121cmay be arranged at equal angle interval (for example, 120 degrees). The first indexing groove121amay have a first width, the second indexing groove121bmay have a second width greater than the first width, and the third indexing groove121cmay have a third width greater than the second width.

The conditioner disk120inFIG. 9may include first, second and third indexing conductors121d,121e, and121f. The first to third indexing conductors121d,121e, and121fmay include a conductive material such as a metal pattern, bolt, etc. The first indexing conductor121dmay have a first size, the second indexing conductor121emay have a second size greater than the first size, and the third indexing conductor121fmay have a third size greater than the second size.

The conditioner disk120inFIG. 10may include a plurality of indexing magnetic bodies121g. The indexing magnetic bodies may be arranged along a circumferential direction about the center of the conditioner disk120. A distance between the indexing magnetic bodies121gor magnetic forces of the indexing magnetic bodies121gmay be changed to provide singular points according to the angle position.

In example embodiments, as illustrated inFIG. 4, the data processor300may convert an analog output signal from the eddy current sensor200into two-dimensional plane profile on the upper surface of the conditioner disk120and determine a height of the polishing pad20and a failure of the polishing pad conditioner100from the converted two-dimensional plane profile. The data processor300may include a data receiver372, a data converter374, a calculator376and a storage portion378.

The data receiver372may receive the analog output signal from the eddy current sensor200. The data receiver372may receive detection values of the rotation angle α and the swing angle θ from the table rotary encoder and the conditioner arm rotary encoder.

The data converter374may convert the output signal from the eddy current sensor200into two-dimensional plane profile data of a constant height by using a first calibration map. The data converter374may convert (match) the output value (e.g., voltage signal) of the eddy current sensor200into height data of two-dimensional plane by a second calibration map. The storage portion378may store the first and second calibration maps. As described later, the first and second calibration maps may be obtained by using a calibration jig.

The calculator376may calculate the height of the conditioner disk120based on the converted two-dimensional plane data and the height data and determine a height of the polishing pad30. The calculator376may calculate positions of detection points on the polishing pad30to generate a height distribution of the polishing pad30. The calculator376may determine a failure of parts of the polishing pad conditioner100and whether the part should be replaced or not.

The controller400may control to terminate a conditioning operation on the polishing pad30according to the height of the polishing pad30or the failure of the polishing pad conditioner100determined in the data processor300. The data processor300, controller400, data receiver372, data converter374, and calculator376may be implemented with dedicated hardware, software, and circuitry configured to perform the functions described herein. These elements may be physically implemented by electronic (or optical) circuits such as logic circuits, discrete components, microprocessors, hard-wired circuits, memory elements, wiring connections, and the like.

Hereinafter, a method of calibrating the output signal from the eddy current sensor will be explained.

FIG. 11is a perspective view illustrating a calibration jig used for data conversion in a polishing pad monitoring apparatus in accordance with example embodiments.FIG. 12is a graph illustrating a first calibration map for converting analog output data into two-dimensional plane profile data of a constant height by using the calibration jig inFIG. 11.FIG. 13is a second calibration map for converting analog output data into height data of two-dimensional plane by using the calibration jig inFIG. 11.

Referring toFIG. 11, a calibration jig500may include a base502, a column504, a first support510and a second support520. The column504may extend in a vertical direction on the base502. The first support510may extend in a horizontal direction from the column504to face the second support520. The second support520may be disposed on the base502to face the first support510.

The first support510may support fixedly a disk head110on a lower surface thereof. The second support520may support rotatably a conditioner disk120on an upper surface thereof. A relative vertical distance between the first support510and the second support520may be adjusted to be changed. For example, the second support520may be installed on the base502to be movable upwardly and downwardly in the vertical direction. Alternatively, the first support510may be installed to be movable upwardly and downwardly in the vertical direction along the column504.

An eddy current sensor200as a displacement sensor may be installed in a disk head110of a polishing pad conditioner100to detect a displacement of a conditioner disk120. Indexing structures121may be provided in an upper surface of the conditioner disk120. After the disk head110is secured to the lower surface of the first support510and the conditioner disk120is secured to the upper surface of the second support520, while rotating the conditioner disk120and changing a distance between the disk head110and the conditioner disk120, a calibration map for converting analog voltage signal data from the eddy current sensor200may be obtained. For example, the calibration map may represent reference values indicating respective distances of portions of the conditioner disk120with respect to the eddy current sensor200, and the polishing pad30may be examined on the basis of the reference values when the polishing pad conditioner100performs the conditioning process of the polishing pad30.

Referring toFIG. 12, a displacement value detected by the eddy current sensor200may form a waveform P1according to a rotation angle of the conditioner disk120. The upper surface of the conditioner disk120may not be even and there may be a conductor such as a bolt in the upper surface. During one revolution of the conditioner disk120, singular points (e.g., a, b, and c) may be provided by indexing structures121to appear in the waveform. The singular points may provide a rotational speed (rpm) and a rotational angular displacement of the conditioner disk120and a displacement deviation value (e.g., offset value).

Since the eddy current sensor200is influenced by a shape of the conditioner disk120and a magnetic field, a plane profile of waveform (P1) may be offset compensated by reflecting the displacement deviation value of the singular points to obtain a two-dimensional plane profile (P2) of a constant displacement value, e.g., a constant height. A correlation between the plane profile of waveform (P1) and the two-dimensional plane profile (P2) may be stored as the first calibration map in the storage portion378. Accordingly, disturbances due to the surface of the conditioner disk, the shape of the conductor, the magnetic field, etc. may be reduced or removed from the output signal of the eddy current sensor200to obtain a constant displacement value. For example, raw data (as represented by graph P1ofFIG. 12) detected by the eddy current sensor200may be compensated to eliminate influences of singular points and other influences thereby forming the first calibration map so that the first calibration map has a flat plane reference as represented by graph P2ofFIG. 12.

Referring toFIG. 13, while changing a relative distance between the first support510and the second support520, analog output values (e.g., voltage values) of the eddy current sensor200to obtain a correlation between the sensing values (e.g., voltage values) of the eddy current sensor200and the relative distance D. The correlation may be stored as the second calibration map in the storage portion378.

Since the eddy current sensor200is installed in the disk head110that is a conductor, the eddy current sensor200may be interfered by a surrounding conductor material. For example, because the disk head110is a conductor, the disk head110may affect a signal detected by the eddy current sensor200. Graph G1may represent a correlation between the voltage signal outputting from the eddy current sensor200and the relative distance without the surrounding conductor material, and graph G2may represent a correlation (e.g., second calibration map) between the voltage signal outputting from the eddy current sensor200and the relative distance when the detected signal is affected by the surrounding conductor material when the eddy current sensor200is installed in the disk head. Accordingly, the detected voltage value may be matched to a precise distance by reflecting the changes in the voltage signal due to the interference, thereby calculating a precise height of the conditioner disk120. For example, by compensating the influence of the ambient conductive material, more precise distances may be obtained. For example, by producing and applying the second calibration map (e.g., graph G2ofFIG. 13) in measuring a distance, a more precise distance of an object from the eddy current sensor200may be obtained.

Hereinafter, a method of monitoring a polishing pad during a conditioning process performed on a polishing pad using the polishing pad monitoring apparatus will be explained.

FIG. 14is a flow chart illustrating a polishing pad monitoring method in accordance with example embodiments.

Referring toFIGS. 1, 4, 7 and 14, a displacement sensor such as an eddy current sensor200may be positioned over a conditioner disk120(S100).

In example embodiments, the displacement sensor such as the eddy current sensor200may be installed in a disk head100which is configured to rotate a disk shaft130connected to the conditioner disk120.

The displacement sensor is not limited to the eddy current sensor200. For example, the displacement sensor may include a non-contacting sensor or another displacement sensor. The non-contacting sensor is not limited to the eddy current sensor200. For example, the non-contacting sensor may include an eddy current sensor200or another non-contacting sensor. The eddy current sensor200may be installed in a lower surface of the disk head110. A plurality of the eddy current sensors200may be installed at equal angle interval along a circumferential direction of the disk head110to be spaced apart from each other.

The conditioner disk120may include indexing structures121which are arranged at equal angle interval about a disk center in the upper surface of the conditioner disk120.

Then, the conditioner disk120may be rotated to perform a conditioning process on a polishing surface32of a polishing pad30(S110), a displacement of the rotating conditioner disk120may be detected by using the displacement sensor such as the eddy current sensor200during the conditioning process on the polishing surface32(S120), and then a height of the conditioner disk120may be calculated from the detected displacement (S130).

A conditioner arm102may swing to move the conditioner disk120over the polishing pad30, the conditioner disk120may be rotated and the conditioner disk120may be pressed against the polishing surface32of the polishing pad30with a predetermined load. The eddy current sensor200may transmit a voltage signal to a data processor300each time the eddy current sensor200detects a height of the upper surface of the rotating conditioner disk120.

A displacement value detected by the eddy current sensor200may form a waveform with respect to a rotation angle of the conditioner disk120. During one revolution of the conditioner disk120, singular points (a, b, c) may appear in the waveform by indexing structures121.

A data converter374may offset compensate a plane profile of waveform (P1) by reflecting displacement deviation values of the singular points by using a first calibration map (seeFIG. 12) to obtain a two-dimensional plane profile (P2) of a constant displacement value, e.g., a constant height. A calculator376may calculate a height (e.g., displacement) of the conditioner disk120during one revolution of the conditioner disk120based on the two-dimensional plane profile (P2).

A data converter374may convert (e.g., match) the output value (e.g., voltage signal) of the eddy current sensor200into height data of two-dimensional plane by using a second calibration map (seeFIG. 13).

Then, an end point of the conditioning process on the polishing surface32may be determined based on the calculated height (e.g., distance) (S140).

The data processor300may calculate a change in a height of the polishing pad30, a change in a rotational speed (rpm) of the conditioner disk120, a change in a swing speed of the conditioner arm102, a change in a displacement of the conditioner disk120during the swing operation of the conditioner arm102, etc.

The end point of the conditioning process may be determined based on the height of the polishing pad30. A change in a pressure of the conditioner disk120against the polishing pad32may be determined from the change in the height of the polishing pad30. A failure and replacement time of parts in the polishing pad conditioner100may be determined based on the change in the rotational speed (rpm) of the conditioner disk120, the change in the swing speed of the conditioner arm102, the change in the displacement of the conditioner disk120during the swing operation of the conditioner arm102.

A controller400may output analysis result/data to a polishing apparatus10and/or may control operations of the polishing apparatus10.

As mentioned above, in the polishing pad monitoring method, a movement (displacement) of the rotating conditioner disk120may be detected by using the eddy current sensor200installed in the disk head110, and the height of the polishing pad30and the failure and replacement time of the parts in the polishing pad conditioner100may be determined.

Accordingly, since a precise profile of the polishing pad30is obtained during the conditioning process, the polishing pad conditioning process may be analyzed precisely, and fault diagnosis for movement balance (sweep, rotation) maintenance of the conditioner disk120may be performed easily. For example, a problem with the conditioner disk120and/or the polishing pad30may be easily detected by the polishing pad monitoring method so that troubleshooting may be promptly performed.

The above polishing pad monitoring method and apparatus may be applied to a CMP process. Semiconductor devices such as DRAM, VNAND, etc. manufactured by using the CMP process may be used for various systems such as a computing system. The system may be applied to computer, portable computer, laptop computer, PDA, tablet, mobile phone, digital music player, etc. For example, the CMP process may be applied on a substrate such as a semiconductor wafer to form a conductor pattern or an insulator pattern on the substrate. The substrate may be diced into a plurality of chips, and each of the chips may be packaged to form a semiconductor device such as a DRAM, a VNAND, etc.