JP5218892B2 - Consumable evaluation method - Google Patents

Description

  The present invention relates to a method for evaluating a consumable material used in a polishing apparatus for flattening a substrate surface such as a semiconductor wafer.

  A CMP apparatus is exemplified as a polishing apparatus for polishing the substrate surface. A CMP apparatus is widely used for polishing a substrate such as a silicon substrate, a glass substrate, or a semiconductor wafer as a technique for polishing a substrate surface with high precision by chemical mechanical polishing (CMP). In such a polishing apparatus, the substrate held by the chuck and the polishing pad mounted on the polishing head are relatively rotated and pressed, and a slurry (Slurry) corresponding to the polishing content is brought into contact with the substrate and the polishing pad. Is supplied to cause a chemical / mechanical polishing action, and the substrate surface is polished flat (see, for example, Patent Document 1).

In such a CMP apparatus, a large number of consumables such as a polishing pad, a retainer ring of a polishing head, a backing film for holding a wafer, and a slurry are used. The consumption of these members has a great influence on the polishing quality such as the flatness and uniformity of the substrate, and therefore has been replaced regularly or irregularly.
JP 2006-319249 A

  In the conventional CMP apparatus, after the consumables are replaced as described above, the conditions of the polishing recipe (combination of processing conditions such as the rotation speed of the substrate, the rotation speed of the polishing pad, and the relative rocking speed of the polishing pad with respect to the substrate) are satisfied. After performing the unloading work, the polishing of the substrate was resumed. However, after resuming the polishing process, if the desired flatness / uniformity cannot be obtained on the surface to be polished of the substrate, whether it is derived from the replaced consumable material or the polishing recipe, the cause It was difficult to identify and repeated trial and error.

  Further, even if it can be identified that there is a cause in the polishing recipe, it is difficult to determine how much the conditions of the recipe should be changed. For this reason, if the desired polishing quality cannot be obtained, it is necessary to repeat the test processing using the monitor wafer while changing each condition value of the polishing recipe and reset the polishing recipe. This was a factor that hindered productivity in terms of cost. For this reason, there has been a strong demand for polishing without changing the proven polishing recipe as much as possible.

  The present invention has been made in view of such problems, and it is possible to improve productivity by accurately evaluating the consumable material after replacement using an existing polishing recipe. It aims at providing the evaluation method of material.

  In order to achieve such an object, the present invention provides a holding mechanism for holding a substrate, a polishing pad capable of polishing the substrate, and holding the polishing pad so as to face the substrate held by the holding mechanism. And moving the polishing surface of the polishing pad held by the polishing head in contact with the surface to be polished of the substrate held by the holding mechanism. A method for evaluating a consumable material in a polishing apparatus that performs polishing processing, and when a polishing processing condition is input, a circle of a polishing amount on the surface to be polished after polishing based on the input processing condition The processing conditions are corrected so that the theoretical variation in the circumferential direction is equal to or less than a predetermined reference value, and one of the consumables constituting the polishing apparatus is replaced with a consumable for evaluation, and the corrected processing The substrate is polished based on the condition, the actual variation in the circumferential direction of the polishing amount on the surface to be polished of the substrate is calculated, and based on the calculated actual variation, the replaced consumable material Evaluate.

  According to the present invention, when trouble occurs after replacement of consumables constituting the polishing apparatus, it is possible to easily identify the cause, and a new polishing recipe after replacement of consumables, which has been essential in the past. Therefore, time and cost can be reduced because it is not necessary to perform a complicated operation of determining the conditions.

  Therefore, according to the present invention, it is possible to provide a consumable material evaluation method capable of improving productivity by accurately evaluating a consumable material after replacement using an existing polishing recipe. it can.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. A CMP apparatus (chemical mechanical polishing apparatus), which is a representative example of the polishing apparatus according to the present invention, is shown in FIG. 1, and first, an outline of the overall configuration of the polishing apparatus PM will be described with reference to this drawing. The polishing apparatus PM is roughly divided into a cassette index unit 1 that carries in and out a substrate such as a silicon substrate, a glass substrate, and a semiconductor wafer (hereinafter referred to as wafer W), a polishing processing unit 2 that performs polishing, The substrate cleaning unit 3 that cleans the wafer W after the polishing process and the transfer device 4 (the first transfer robot 41 and the second transfer robot 42) that transfer the wafer W in the polishing apparatus PM are included. Each of them is partitioned by an automatic open / close shutter to form a clean chamber. The operation of the polishing apparatus PM is controlled by a control apparatus 400 (see FIG. 2) described later.

The cassette index unit 1 is provided with a wafer mounting table 12 on which cassettes (also referred to as carriers) C _{1 to} C ₄ each holding a plurality of wafers W are mounted, and in front of the wafer mounting table 12. A first transfer robot 41 is provided. The first transfer robot 41 is an articulated arm type robot, and a swivel that can be swung horizontally and moved up and down is provided on an upper part of a base that can move along a linear guide provided on the floor. The articulated arm attached to the arm can be extended and contracted, and the outer peripheral edge of the wafer W can be gripped by the wafer chuck at the tip of the arm. The unprocessed unprocessed wafer W taken out from the send cassettes C ₁ and C ₂ by the first transfer robot 41 is polished in a path for transferring the unprocessed wafer W provided in the substrate cleaning unit 3. Passed to the second transfer robot 42 of the section 2.

The polishing unit 2 is divided into four areas around a circular index table 20 that is rotated and fed every 90 degrees, and a transfer stage S that carries in the unprocessed wafer W and unloads the processed wafer W. ₀ , a first polishing stage S ₁ for polishing the wafer surface, a second polishing stage S ₂ , and a third polishing stage S ₃ . The index table 20 is divided into four corresponding to these four stages.

The transfer stage S _0, the second transfer robot 42 is provided. Wafer W carried into the polishing unit 2 by the second transfer robot 42 is conveyed by the second transfer robot 42 is placed on a wafer chuck 200 which is positioned in the conveying stage S ₀ adsorbent is held.

In the first polishing stage S ₁ , the second polishing stage S ₂ , and the third polishing stage S ₃ , a polishing mechanism 22 (pad rotating mechanism) that polishes the surface of the wafer W attracted and held by the wafer chuck 200 and a polishing are respectively provided. A dressing mechanism 23 (tool rotation mechanism) for dressing the polishing surface 220s of the pad 220 is provided.

  As shown in FIG. 2, the polishing mechanism 22 has a polishing pad 220, a polishing head 222 that holds and rotates the polishing surface 220s of the polishing pad in a downward horizontal posture, and horizontally swings and lifts the polishing head. The wafer surface includes a polishing arm 223 and the wafer chuck 200 that rotates the wafer surface in an upward horizontal posture. The wafer surface is polished under processing conditions corresponding to the process contents performed on each stage. The diameter of the polishing pad 220 is set smaller than the diameter of the wafer W to be polished.

  The wafer surface is polished by the polishing mechanism 22 while the polishing arm 223 is horizontally swung and the polishing head 222 is positioned above the wafer chuck. The polishing surface 220 s of the polishing pad 220 is pressed against the surface of the wafer W held and rotated (surface to be polished Ws) with a predetermined pressure, and the polishing arm 223 is swung while supplying slurry from the center of the polishing head. The entire surface of the wafer W is polished flatly.

  The polishing pad 220 used in each polishing mechanism 22 includes a processing process such as interlayer insulating film CMP and metal CMP, circuit pattern fineness, primary polishing (rough polishing) to third polishing (finish polishing), and the like. An appropriate pad is selected and mounted according to the processing stage. The polishing head 222 is provided with a slurry supply structure that passes through the center and supplies the slurry to the center of the annular polishing pad 220. During the polishing process, slurry corresponding to the processing purpose is supplied from the slurry supply device. It comes to be supplied. Further, an end point detector for optically detecting the polishing state of the wafer being polished is attached to the tip of the polishing arm 223 so that a decrease in film thickness during the polishing process is detected in real time, and the end point of the polishing process is detected. The feedback control is possible.

  The dressing mechanism 23 is configured to include a dressing tool 230 and a rotating structure that rotates the dressing tool 230 in an upward horizontal posture, and swings the polishing arm 223 to move the polishing head 222 onto the dressing tool 230. The polishing pad 220 is lowered while rotating to bring the polishing surface 220s into contact with the relatively rotating dressing surface 230s, and pure water is supplied from a nozzle (not shown in detail) to the dressing processing portion to wash away grinding debris and the like. Configured to dress.

As shown in FIG. 1, the index table 20 is rotated 90 degrees when the polishing process in the _first to third polishing stages S ₁ , S ₂ , S ₃ is completed, and is held by the wafer chuck 200 by suction. Are sequentially transferred from the transfer stage S ₀ to the first polishing stage S ₁ → the second polishing stage S ₂ → the third polishing stage S ₃ and subjected to CMP processing at each polishing stage, and polishing processing at the third polishing stage S _3. but finished wafer W is fed to the transfer stage S _0. The processed wafer W that has been sent to the transfer stage S ₀ and released from the suction and holding is transferred from the polishing unit 2 to the substrate cleaning unit 3 by the second transfer robot 42.

  The substrate cleaning unit 3 is composed of four chambers, a first cleaning chamber 31, a second cleaning chamber 32, a third cleaning chamber 33, and a drying chamber 34. The polishing process on both the front and back surfaces is completed, and the substrate is transferred by the second transfer robot 42. The processed wafer W is sequentially sent to the first cleaning chamber 31-> second cleaning chamber 32-> third cleaning chamber 33-> drying chamber 34 to remove and wash the slurry and abrasive wear powder adhering to the polishing processing section 2. Is done. There are various examples of cleaning methods in each cleaning chamber. For example, in the first cleaning chamber 31, double-sided cleaning with a rotating brush, in the second cleaning chamber 32, surface pencil cleaning under ultrasonic vibration, the third cleaning chamber In 33, spinner cleaning with pure water is performed, and in the drying chamber 34, a drying process is performed in a nitrogen atmosphere. A passage for transferring the unprocessed wafer W is provided below the first cleaning chamber 31.

The processed wafers W cleaned by the substrate cleaning unit 3 are taken out from the substrate cleaning unit 3 by the first transfer robot 41 and placed in predetermined slots of the receive cassettes C ₃ and C ₄ mounted on the wafer mounting table 12, Alternatively, it is accommodated in the empty slots of the send cassettes C ₁ and C ₂ .

  As shown in FIG. 2, the control device 400 outputs control signals to the polishing mechanism 22 and the dressing mechanism 23 of the polishing processing unit 2, the cassette index unit 1, the substrate cleaning unit 3, the transfer device 4, and the like, Configured to control the operation of. Further, the control device 400 is electrically connected to an input unit 410 for inputting various commands and data, and a condition setting unit 420 for setting and changing polishing and dressing conditions.

Next, the action of the polishing apparatus PM when the surface of the semiconductor wafer W is polished using the polishing apparatus PM will be described with reference to FIG. Here, FIG. 3 shows that the unprocessed wafers W accommodated in the send cassette C ₁ of the cassette index unit 1 are sequentially polished by the polishing unit 2 and cleaned by the substrate cleaning unit 3. the flow of the wafer W to be housed in the receive cassette C ₄ illustrates denoted by the dotted arrow. The operation of the polishing apparatus PM is controlled by a control device 400 (see FIG. 2), and the control device 400 controls the operation of each unit based on a preset control program.

When the polishing processing program is started in the polishing apparatus PM, the first transfer robot 41 moves to the position of the send cassette C ₁ , horizontally swings and lifts the swivel, and expands the articulated arm to move the wafer chuck. The unprocessed wafer W in the slot is taken out, and the swivel base is turned 180 degrees to go to a passage installed below the first cleaning chamber 31, and the second transfer robot 42 on the polishing processing unit 2 side in this passage. Deliver raw wafers to

The second transfer robot 42 that has received the unprocessed wafer W from the first transfer robot 41 carries the unprocessed wafer into the polishing unit 2. The raw wafer W is transferred to the polishing mechanism 22 by the second transfer robot 42, it is placed on the wafer chuck 200 of the conveying stage S ₀ positioned stopped index table 20. When the wafer W is placed, the wafer chuck 200 holds the back surface of the wafer by vacuum suction, and the second transfer robot 42 retreats.

Polishing is started in the first polishing stage S ₁ to the third polishing stage S ₃ of the polishing mechanism 22. Since polishing of the wafer surface performed in such three stages of polishing stages S _{1 to} S ₃ is already known (for example, Japanese Patent Application Laid-Open No. 2002-93759 by the present applicant), in this specification, Detailed description will be omitted, and a brief description will be given below.

When the second transfer robot 42 is retracted, the index table 20 is positioned suction-held wafer W is in a first polishing stage S ₁ the wafer chuck 200 is rotated 90 degrees clockwise, the polishing arm 223 simultaneously swing Then, the polishing head 222 moves on the wafer W. Then, the polishing head 222 and the wafer chuck 200 start to rotate in opposite directions and the polishing head 222 descends to press the polishing pad 220 (polishing surface) against the wafer surface (surface to be polished) to perform the primary polishing process. . During the polishing process, the polishing arm 223 is swung so that the polishing pad 220 reciprocates between the rotation center and the outer peripheral end of the wafer W while supplying the slurry from the axis of the polishing head 222, and the wafer surface. Is uniformly flat polished.

When the first polishing process is completed, the controller 400 further rotates the index table 20 by 90 degrees clockwise, and the wafer after the first polishing process is transferred to the second polishing stage S ₂ and the transfer stage S _0. The wafer waiting in step ₁ is positioned on the first polishing stage S1. Then, the polishing head 222 is lowered at the first and second polishing stages, respectively, and the first polishing process and the second polishing process are simultaneously performed in parallel.

When the second polishing process is finished, the control device 400 checks whether or not the first polishing process is finished. If the first polishing process is finished, the control device 400 further rotates the index table 20 clockwise. The wafer that has been rotated 90 degrees and has finished the second polishing process is placed on the third polishing stage S ₃ , and the wafer that has finished the first polishing process is placed on the second polishing stage S ₂ on the transfer stage. was positioned at the first polishing stage S _1, lowers the polishing head 222, respectively, first, second, to take such a third-order polished simultaneously.

When the third polishing process is finished, the control device 400 checks whether or not the first polishing process and the second polishing process are finished, and when all the polishing processes are finished, the index table 20 Is rotated 90 degrees clockwise to position the wafer W, which has been subjected to the third polishing process, to the transfer stage S _{0 and} to move the wafers W positioned on the other stages one by one as described above. .

When the index table 20 is stopped and the wafer W, whose surface polishing is completed through the _first to third polishing stages S _{1 to} S ₃ , is positioned on the transfer stage S ₀ , the second transfer robot 42 is placed on the wafer chuck 200. Then, the outer peripheral edge of the processed wafer W from which the vacuum suction is released is gripped and lifted and swiveled, moved horizontally along the linear guide, and transferred to the substrate cleaning unit 3. Further, after the processed wafer W is transferred, the unprocessed wafer W is received from the first transfer robot 41 and carried into the polishing processing unit 2.

In the substrate cleaning unit 3, double-sided cleaning with a rotating brush in the first cleaning chamber 31, surface pencil cleaning under ultrasonic vibration in the second cleaning chamber 32, spinner cleaning with pure water in the third cleaning chamber 33, and the drying chamber 34. The drying process is performed in a nitrogen atmosphere. The finished product wafer that has been cleaned in this way is removed from the substrate cleaning unit 3 by the first transfer robot 41 of the cassette index portion 1 is accommodated in the specified slot from the receive cassette C _4.

The above operations are sequentially repeated, and after the polishing of the first wafer is completed, the wafer W whose front and back surfaces are polished flat is stored in the cassette C ₄ at every rotation interval of the index table 20. The The rotation interval of the index table 20 is defined by the polishing time divided into three stages. For example, the finished wafer W is continuously produced at every time interval of the first polishing process. In addition, dressing by the dressing mechanism 23 is performed each time before each polishing process is performed in each polishing stage, and the clogging of the polishing pad surface (polishing surface 220s) is corrected to ensure flatness.

  It should be noted that polishing conditions (parameters) such as the rotation speed of the wafer chuck 200, the rotation speed and movement speed of the polishing head 222, the polishing pressure, the polishing time for the wafer W, the type and supply amount of the slurry, etc. are input in advance by the input unit 410. Then, it is set and stored as a recipe file in the internal memory of the control device 400, and the control device 400 controls the operation of each device based on the data of this recipe file.

  In this embodiment, the evaluation of the replaced consumables (for example, the wafer chuck 200, the polishing pad 220, the slurry, and the dressing tool 230 for holding the wafer W) is corrected in advance to suppress asymmetry. The polishing process is performed on the wafer W using the polishing recipe, and the actual variation in the circumferential direction of the polishing amount on the surface to be polished of the wafer W after the actual polishing process is calculated. It has become.

  Below, the evaluation method of the consumable material in this embodiment is demonstrated, referring the flowchart shown in FIG. First, in step S1, when a polishing recipe (processing conditions) for polishing is input from the input unit 410, the control device 400, based on the input polishing recipe, the surface to be polished of the wafer W after polishing. The theoretical variation in the circumferential direction of the polishing amount at is calculated.

  Here, a calculation method of the theoretical variation in the circumferential direction of the polishing amount on the surface to be polished of the wafer W in step S1 will be described. First, the rotational speed of the polishing pad 220, the rotational speed of the wafer W, the swing start point and the swing stroke of the polishing pad 220 with respect to the wafer W, which are parameters that define the travel locus of the polishing pad 230 from the input polishing recipe. Then, the rocking speed of the polishing pad 220 is acquired, and the traveling locus of each part of the polishing pad 220 on the surface to be polished of the wafer W is calculated based on these condition values. Since the traveling locus formed on the surface to be polished of the wafer W is a polishing locus that is polished by an arbitrary point on the polishing pad 220, the higher the amount of traveling locus, the higher the polishing amount, and the traveling locus density becomes higher. The lower the value, the lower the polishing amount.

Next, the control device 400 accumulates the travel locus for each part of the polishing surface of the polishing pad 220 by the polishing processing time, and calculates the density distribution of the travel locus formed on the surface to be polished of the wafer W. For example, any point P of the polishing pad 230, the circumferential direction in 5 degree pitch, set in the radial direction as a number of travel point P ₁ to P _n of 5mm pitch, running locus L of each point of P ₁ to P _n by integrating the ₁ ~L _n for polishing time period, we calculate the density distribution of the traveling locus of the polishing surface on the polished surface.

  Subsequently, from the surface distribution of the polishing amount calculated based on the calculated density distribution of the running trajectory, the polishing amount variation (theoretical variation) in the circumferential direction on the same radius, that is, the distribution of polar polishing amount (Polar Removal) Is calculated.

  In the present embodiment, the variation in the polishing amount in the circumferential direction on the same radius of the wafer W is a polar range (Polar Range = (maximum polishing), which is one of the indexes representing the non-uniformity of the polishing amount distribution. Amount Max-minimum polishing amount Min) / average polishing amount Average).

  A large value of the polar range means that the polishing amount on the same radius is not uniform, that is, an asymmetry occurs in the surface distribution of the polishing amount. Therefore, in step S2, the control device 400 determines whether or not the theoretical variation in the circumferential direction of the polishing amount on the surface to be polished of the wafer W is equal to or less than a predetermined reference value, in other words, the maximum of the calculated polar range. Determine whether the value (Max Polar Range) exceeds a predetermined reference value. If the determination is Yes, the process proceeds to step S4. If the determination is No, the process proceeds to step S3 so that the theoretical variation in the circumferential direction of the polishing amount on the surface to be polished of the wafer W is not more than a predetermined reference value, that is, the maximum polar range is not more than the predetermined reference value. After the polishing recipe is corrected so that the asymmetry of the surface distribution of the polishing amount of the recipe is improved, the process proceeds to step S4.

  The predetermined reference value can be set as appropriate according to the object to be polished and the production process. For example, in a polishing line for semiconductor wafers, a typical actual polishing tolerance is about 10% in the polar range. In the embodiment, the polar range is set to 3% or less as a predetermined reference value for the simulation calculation.

  Next, in step S4, one of the consumable materials constituting the polishing apparatus PM is replaced with a consumable material for evaluation.

  Subsequently, in step S5, the control device 400 polishes the wafer W based on the polishing recipe that has been corrected to suppress asymmetry.

  In step S6, the shape of the wafer W that has been subjected to actual polishing is measured, and the actual variation in the circumferential direction of the polishing amount on the surface to be polished of the wafer W is calculated.

  Subsequently, in step S7, the control device 400 evaluates the replaced consumable material based on the actual variation calculated in step S6. Specifically, the maximum value of the polar range is a predetermined reference. It is determined whether or not the value is exceeded. Here, the surface distribution of the polishing amount after actual polishing is asymmetrical despite the use of a corrected polishing recipe in which the maximum value of the polar range exceeds the predetermined reference value, that is, the asymmetry is suppressed. In the present embodiment, an alarm is activated because there is a high possibility that the replaced evaluation consumable material has a problem. The alarm activation is a visual alarm such as displaying letters or pictures on the display device or turning on the LED that the polishing amount distribution is likely to cause asymmetry, and an auditory alarm by voice or buzzer. It means operation including. With such a configuration, the operator, for example, reads the occurrence position of the consumable material defect from the data result, and repairs or re-replaces the corresponding part mainly by reworking or re-polishing. This makes it possible to respond quickly and easily and improve productivity.

  Here, the case where the consumable material wafer chuck A is evaluated using the above method will be described.

As the corrected polishing recipe X, the rotation speed V _p = 110 [rpm] of the polishing pad 230, the rotation speed V _w = −108 [rpm] of the wafer W, and the oscillation start point of the polishing pad 230 relative to the wafer W is the wafer center. To 32 [mm], swing stroke 95 [mm], swing speed V _s = 63 [mm / sec], and polishing time 30 [sec] are set. In this polishing recipe, the distribution of the polishing amount is the wafer W as shown in the calculated distribution data (Simulation Date) of the polishing amount shown in FIG. 5 and the calculated polar range shown in the dark bar graph of FIG. It is a recipe that is almost axisymmetric with respect to the central axis, in other words, a recipe with reduced asymmetry (Polish Recipe without Asymmetry). In the present embodiment, the maximum value of the polar range (Max Polar Range) is 1.4% (the allowable value for the simulation calculation is 3% or less).

On the other hand, the rotational speed V _p = 110 [rpm] of the polishing pad 230, the rotational speed V _w of the wafer W = −111 [rpm], and the swing start point of the polishing pad 230 relative to the wafer W is 32 [mm] from the wafer center. When setting a polishing recipe (Polish Recipe with Asymmetry) Y with an oscillation stroke of 95 [mm], an oscillation speed V _s = 60 [mm / sec], and a polishing time of 30 [sec]. The calculated polar range is indicated by a light bar graph in FIG. The maximum value of the polar range of this polishing recipe Y was 9.6%. As shown in FIG. 6, when the asymmetry is generated in the polishing recipe as in the polishing recipe Y, the maximum value of the polar range generally tends to be larger than in the case where there is no asymmetry as in the polishing recipe X. It can be seen that the distribution is non-uniform.

  Subsequently, after replacing the consumable material wafer chuck A, the actual polishing of the wafer W was performed using the corrected polishing recipe X described above, and the data shown in FIGS. 7 to 9 were obtained.

  FIG. 7 shows measurement data of the surface distribution of the polishing amount obtained by measuring the shape of the wafer W that has been subjected to actual polishing processing by applying the corrected polishing recipe X. As can be seen from FIGS. 5 and 7, the surface distribution of the polishing amount obtained by calculating the corrected polishing recipe X, and the surface distribution of the polishing amount obtained by measuring the wafer W after the actual polishing process, It can be seen that there is a very high correlation between the two.

  FIG. 8 shows measurement data (Polish Raw Data) in which the distribution of the polishing amount of the actual polished wafer W shown in FIG. 7 is graphed. The horizontal axis in the figure is the radial position of the wafer W (the left end is the wafer). The center to the right end are the wafer outer periphery), and the vertical axis is the polishing amount. The data plotted in large numbers at the same radius position is the actual variation of the polishing amount in the circumferential direction at an angle of 0 to 360 degrees located on the circumference of the same radius, that is, the distribution of polar polishing amount (Polar Removal). . FIG. 9 further shows the variation (actual variation) of the polishing amount in the circumferential direction on the same radius (actual variation) in the wafer W after the actual polishing processing in the polar range (Polish Raw Data) from the data of FIG. . From FIG. 9, the variation in the amount of polishing in the circumferential direction on the same radius was almost uniform, and the maximum value of the polar range (Max Polar Range) was 9.0% (the allowable value for actual polishing was 10%). Below).

  As apparent from FIGS. 7 to 9, the replaced consumable wafer chuck A almost coincides with the calculated result in the corrected polishing recipe X, and has a large asymmetry in the surface distribution of the actual polishing amount. It can be seen that is not occurring. With regard to the replaced wafer chuck A, the maximum value of the actual polishing polar range is within the allowable value and there is no particular problem, but it can also be seen that there is room for further improvement of the entire surface of the wafer chuck A.

  For comparison, FIG. 10 shows a polar range in the case where actual polishing is performed using the corrected polishing recipe X after the consumable material wafer chuck B is replaced. From this figure, it can be seen that the variation in the circumferential direction on the same radius is small near the center of the wafer W and largely uneven near the outer periphery, and the maximum polar range is 10.3. It can be seen that the predetermined reference value was exceeded. Therefore, in exchanging the consumable material wafer chuck B, a relatively large asymmetry is generated in the surface distribution of the polishing amount on the outer periphery of the wafer chuck despite the use of the corrected polishing recipe X. It can be seen that there may be a problem.

  As described above, in the present embodiment, when a problem occurs after replacement of the consumables constituting the polishing apparatus PM, it can be easily identified that the cause of the problem is the replaced consumable material. In this case, it is not necessary to perform a complicated operation of setting conditions for a new polishing recipe after replacement of consumables, and the time and cost for the operation can be reduced. Therefore, productivity can be improved by accurately evaluating the consumable material after replacement using an existing polishing recipe.

  In addition, in order to make the invention which concerns on this embodiment easy to understand, although it attached and demonstrated the component requirement of the said embodiment, it cannot be overemphasized that this invention is not limited to this.

It is a top view of the example of whole composition of the polish device concerning this embodiment. It is a schematic block diagram which shows a grinding | polishing mechanism and a dressing mechanism typically. It is explanatory drawing which shows the flow of the wafer in the said grinding | polishing apparatus. It is a flowchart which shows the evaluation method of a consumable material. It is the simulation data calculated based on the density distribution of the running locus in the polishing recipe in which the asymmetry of the polishing amount surface distribution is suppressed. It is a polar range calculated based on the polishing recipe X in which the asymmetry of the polishing amount surface distribution shown in FIG. 5 is suppressed. It is the measurement data of the surface distribution of the polishing amount of the wafer that has actually been polished in the polishing recipe X. It is the measurement data which graphed distribution of the polish amount of the actual processing wafer in the above-mentioned polish recipe X. Graph showing the variation of the polishing amount in the circumferential direction on the same radius in the wafer W after the actual polishing process using the Polar Range when the polishing recipe X is used after replacing the wafer chuck A It is. Graph showing the variation in the polishing amount in the circumferential direction on the same radius in the wafer W after the actual polishing process using the Polar Range when the polishing recipe X is used after replacing the wafer chuck B It is.

Explanation of symbols

PM polisher W Wafer (substrate)
22 Polishing mechanism (holding mechanism)
23 Dressing mechanism 200 Wafer chuck (consumable)
220 polishing pad 400 control device

Claims (2)

A holding mechanism that holds the substrate; a polishing pad that can polish the substrate; and a polishing head that holds the polishing pad so as to face the substrate held by the holding mechanism;
In a polishing apparatus for polishing a substrate by relatively moving a polishing surface of the polishing pad held by the polishing head in contact with a surface to be polished of the substrate held by the holding mechanism A method for evaluating consumables,
When the processing conditions for polishing are input, based on the input processing conditions, the theoretical variation in the circumferential direction of the polishing amount on the polished surface after polishing is less than or equal to a predetermined reference value. Correct the machining conditions,
Replacing one of the consumables constituting the polishing apparatus with a consumable for evaluation,
Polishing the substrate based on the corrected processing conditions,
Calculate the actual variation in the circumferential direction of the polishing amount on the surface to be polished of the substrate,
A method for evaluating a consumable material, comprising evaluating the replaced consumable material based on the calculated actual variation. The consumable material evaluation method according to claim 1, wherein the consumable material includes a chuck for holding the substrate, the polishing pad, a slurry, and a dresser.

Images