JP2009081410A - Method and device for forecasting and detecting polishing end point, and method and device for monitoring real-time film thickness - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and device for forecasting and detecting a polishing end point, and a method and device for monitoring a real-time film thickness, that suppress Joule heat loss due to an eddy current to the minimum, precisely forecast and detect a polishing end point, precisely calculate a remaining film thickness to be removed, a polishing rate and the like on the spot, and precisely evaluate whether a prescribed conductive film is appropriately removed. <P>SOLUTION: In the forecasting and detecting method, an injector 36 in a high frequency inductor type sensor is arranged adjacently to a prescribed conductive film 28, a magnetic flux change induced in the prescribed conductive film 28 by a magnetic flux formed in the inductor 36 is monitored, and on the basis of a magnetic flux change when a film thickness in polishing becomes a film thickness corresponding to skin depth determined by using a material of the prescribed conductive film 28 as one factor, a magnetic flux change portion for forecasting the polishing end point is detected, the polishing end point is forecasted from the magnetic flux change portion, and further a polishing rate and a remaining film thickness to be removed are calculated on the spot. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to a prediction / detection method at the end of polishing, an apparatus therefor, a real-time film thickness monitoring method, and an apparatus therefor, and in particular, chemical mechanical polishing (CMP).
In addition to minimizing Joule heat loss due to eddy currents in Mechanical Polishing, etc., it is possible to accurately predict and detect the end point of polishing and to accurately evaluate in real time whether a predetermined conductive film has been properly removed. The present invention relates to a polishing end point prediction / detection method and apparatus, and a real-time film thickness monitoring method and apparatus.

  For example, an oxide film is formed on the surface of a semiconductor wafer, and the oxide film is subjected to lithography and etching to form a groove pattern corresponding to the wiring pattern. A process is known in which a film is formed, and unnecessary portions other than the buried portion such as the groove pattern and the through hole portion of the conductive film are removed by chemical mechanical polishing to form a wiring pattern. In the formation of this wiring pattern, it is extremely important to reliably detect the polishing end point when an unnecessary portion of the conductive film has been removed to an appropriate thickness and stop the process. If the polishing of the conductive film is excessive, the resistance of the wiring increases, and if the polishing is insufficient, an insulation failure of the wiring is caused.

  As a conventional technique related to this, for example, the following in-situ monitoring method for a change in film thickness is known. This prior art is a method for in-situ monitoring of a change in thickness of a conductive film in a method of removing the conductive film from a base body (semiconductor wafer) by chemical mechanical polishing, and is directed to an electromagnetic field. A sensor including a series or parallel resonant circuit of an inductor and a capacitor, which is a coil wound around a ferrite pot type core for shaping so as to provide a characteristic, is disposed close to the conductive film, and an excitation signal source A sweep output having a frequency of 20 Hz to 40.1 MHz is applied to the sensor via the operating point setting impedance means. Thus, when the sensor is excited, an oscillating current flows through the coil and generates an alternating electromagnetic field. This alternating electromagnetic field then induces eddy currents in the conductive film. When eddy currents are induced in the conductive film, two effects will occur. First, the conductive film acts as a loss resistance, the effect of which is a resistive load on the sensor circuit, which lowers the amplitude of the resonance signal and lowers the resonance frequency. Second, reducing the thickness of the conductive film has the effect of pulling the metal rod out of the inductor coil, thereby causing an inductance change as well as a frequency shift. In this way, the change in the thickness of the conductive film is continuously detected by monitoring the change in the frequency shift associated with the sensor resonance peak due to the change in the thickness of the conductive film ( For example, see Patent Document 1).

As another conventional technique, for example, the following eddy current sensor is known. In this prior art, a conductive film or a sensor coil (eddy current sensor) disposed in the vicinity of a substrate on which the conductive film is formed, and an AC signal having a constant frequency of about 8 to 32 MHz are supplied to the sensor coil. An AC signal source that forms an eddy current in the conductive film; and a detection circuit that measures a reactance component and a resistance component including the conductive film; and the sensor coil includes an oscillation coil connected to the signal source; A detection coil disposed on the conductive film side of the coil, and a balance coil disposed on the opposite side of the conductive film side of the oscillation coil, the detection coil and the balance coil being in opposite phases to each other Connected to be. A combined impedance is output from the resistance component and reactance component detected by the detection circuit, and a change in the film thickness of the conductive film is detected as a substantially linear relationship over a wide range from the change in the impedance. . (For example, refer to Patent Document 2).

Furthermore, as another conventional technique, for example, the following eddy current sensor is known. Similar to the prior art described above, in this conventional technique, in [0008], the magnetic flux formed by the sensor coil penetrates the conductive film on the substrate disposed on the entire surface of the sensor coil and changes alternately. As a result, an eddy current is generated in the conductive film, and the eddy current flows in the conductive film, resulting in an eddy current loss. In terms of an equivalent circuit, the reactance component of the impedance of the sensor coil is reduced. It is going to be. [0009] In addition, in [0009], by observing a change in the oscillation frequency of the oscillation circuit, as the conductive film becomes gradually thinner as the polishing progresses, the oscillation frequency decreases, and the conductive film is removed by polishing. The self-oscillation frequency of the tank circuit disappears completely, and thereafter, the oscillation frequency becomes substantially constant. Therefore, by detecting this point, the end point by chemical mechanical polishing of the conductive film can be detected. In [0025], as shown in FIG. 2, as the polishing of the conductive film proceeds, the eddy current loss changes accordingly, and the equivalent resistance value of the sensor coil changes. Therefore, since the oscillation frequency of the oscillation circuit changes, the oscillation signal is divided by the frequency divider circuit or subtracted by the subtracter, thereby displaying a signal corresponding to the frequency of the detection width on the monitor. Thereby, the transition of the frequency trajectory as shown in FIG. 2 is obtained (see, for example, Patent Document 3).
Japanese Patent No. 2878178 (pages 2-7, FIGS. 1-15). Japanese Patent No. 3578822 (page 3, FIGS. 1 to 11). Japanese Patent Laid-Open No. 2003-21501

  In the prior art described in Patent Document 1, a series or parallel resonance circuit of an inductor and a capacitor, which is a coil wound around a ferrite pot type core, is provided to provide directivity to an electromagnetic field in a sensor. . Then, a sweep output having a frequency of 20 Hz to 40.1 MHz is applied to the sensor at the initial stage of polishing, and a leakage magnetic flux penetrating the conductive film is generated by an alternating electromagnetic field generated from the coil, thereby generating the conductive current. Large eddy current corresponding to the thickness of the conductive film is induced from the initial stage of polishing. In order to induce a large eddy current corresponding to the thickness of the conductive film, it is necessary to form a large alternating electromagnetic field, that is, a large magnetic flux that penetrates the conductive film, and the thickness of the conductive film changes. This monitoring is performed by using eddy currents induced in the conductive film from the beginning of polishing to the end of polishing. For this reason, it is necessary to penetrate the magnetic flux in the thickness direction of the conductive film while monitoring the change in film thickness. This is also clear from the fact that in the drawing of the publication according to Patent Document 1, magnetic flux lines penetrating through the conductive film are described in all conductive film portions.

  In general, a solid Cu film (conductive film) is the uppermost layer on the surface of the wafer at the initial stage of polishing. In order to induce eddy currents in all of these innocent Cu films, a very large leakage magnetic flux is required. However, the leakage magnetic flux induces eddy currents, which are eventually consumed as Joule heat in the form of eddy current loss. This Joule heat loss has a relatively small volume resistance with respect to the pure Cu film of the outermost layer, so the heat generation is relatively small. Therefore, a large eddy current is induced by the penetrating magnetic flux, resulting in a large Joule heat loss locally. This develops into a problem that part of the wiring sometimes melts and breaks. It becomes a so-called induction heating state, and in particular, it becomes a phenomenon that heat is trapped inside. In particular, in Cu wiring or the like, when Cu is heated, there is a concern that Cu diffuses into a barrier film such as Ta, or in some cases, Cu penetrates the barrier film and diffuses.

In addition, when multiple layers of wiring are applied to the surface of the wafer, not only the surface Cu film is concerned, but the internal wiring that has already been processed is locally warmed to the surroundings. In some cases, the dopant which diffuses or forms p-type and n-type in the semiconductor substrate further diffuses and changes the characteristics of the in-substrate element. Even when no heat is generated, if excessive eddy current flows through the fine wiring, electromigration may occur and disconnection may occur.

  Furthermore, for example, when processing is performed under different polishing conditions when a predetermined residual film amount near the polishing end point is reached, it is difficult to determine whether the amount is a predetermined residual film amount. This is because it can be estimated from the change from the initial film thickness, but when the initial film thickness varies, the estimate of the predetermined remaining film amount varies. Regarding the determination near the end of polishing, if the gap between the sensor and the conductive film changes minutely due to polishing vibration, the stray capacitance of the entire sensor circuit system changes and the entire resonance frequency shifts. Therefore, even if the threshold value is set when the resonance frequency reaches a certain setting and the polishing end point is determined, if the resonance frequency shifts as a whole, the polishing end point by setting the threshold value Judgment becomes difficult. As described above, in the conventional method, even when the threshold value is set to a certain value at the resonance frequency that monotonously and continuously increases or decreases, the gap between the sensor and the conductive film changes slightly, In many cases, the waveform itself translates vertically as a whole due to the presence of any dielectric material, and as a result, the preset threshold value often does not make sense.

  Also in the prior art described in Patent Document 2 using an eddy current sensor, it is described in Patent Document 1 that the change in the film thickness of the conductive film is monitored by the change in eddy current from the initial polishing to the final polishing. This is almost the same as the prior art.

  In addition, in the above-described conventional technique for monitoring the film thickness of the conductive film using eddy current from the initial polishing to the final polishing, a magnetic flux sufficiently strong to penetrate into the film is generated to cause eddy current in the film. The shape of the inductor is three-dimensional in order to give the magnetic flux directivity. For this reason, there are generally the following problems when incorporating a sensor into a polishing apparatus or the like. As the current flowing through the coil increases, the power consumption increases and the power supply device also increases in size. Magnetic flux leaks to the periphery and noise is likely to occur. A process for winding the conductive wire in a coil shape is required, resulting in high costs.

  In the prior art composed of the eddy current sensor described in Patent Document 3, first, regarding the hardware of the sensor unit used in this prior art, first, the configuration assuming that the sensor coil penetrates the conductive film It is. Therefore, with hardware that generates only a magnetic field that does not penetrate the conductive film, an eddy current cannot be formed and the object cannot be achieved. In addition, since the conductive film is reduced by polishing, the region where eddy current is formed monotonously decreases, and therefore, the behavior in which the oscillation frequency monotonously decreases is described, and the oscillation frequency becomes substantially constant. It is assumed that this part is detected by assuming that the end point is the end point. That is, in the software algorithm used in this prior art, the change in the oscillation frequency is a change that becomes substantially constant from the decrease, and the change in the oscillation frequency is, for example, this oscillation frequency has an inflection point. When such changes are made, the algorithm cannot be detected at all. Further, as shown in FIG. 2, the magnetic flux penetrates the conductive film from the initial stage of polishing, and eddy current is always generated. Here, the eddy current sensor generally uses an eddy current sensor as a method of positively generating eddy current from beginning to end and recalculating the eddy current change into a change in film thickness.

Therefore, without exerting a strong magnetic flux to the fine wiring formed in the film, as a result, the generation of eddy currents induced by electromagnetic induction is suppressed, the Joule heat loss due to eddy currents is minimized, and the sensor As a result, the amount of induced eddy current shifts as a whole due to the change in the gap between the conductive film and the normal state of the dielectric material such as slurry, and the setting of the threshold changes drastically, making it difficult to detect. Even a magnetic field that is fine enough not to penetrate the device wafer can be detected with sufficient accuracy, accurately predicting and detecting the polishing end point, and the amount of remaining film to be removed and A technical problem to be solved in order to accurately calculate whether a predetermined conductive film is properly removed by accurately calculating a polishing rate or the like on the spot arises. An object of the present invention is to solve this problem.

The present invention has been proposed in order to achieve the above object, and the invention according to claim 1 is characterized in that the polishing end point when the predetermined conductive film is properly removed by polishing the conductive film is determined. A method for predicting and detecting the end point of polishing for predicting and detecting,
An inductor in a high-frequency inductor type sensor is brought close to the predetermined conductive film, and a change in magnetic flux induced in the predetermined conductive film by a magnetic flux formed by the inductor is monitored. Using the magnetic flux change that appears prominently due to the skin effect determined by the material of the conductive film as a factor, the magnetic flux change portion for detecting the polishing end point is detected during the magnetic flux change process, and polishing is performed from the magnetic flux change portion. Provided is a method for predicting and detecting a polishing end point, wherein the end point is predicted.

  According to this configuration, the inductor is driven at a high frequency, and a magnetic flux that changes in accordance with the cycle of the high frequency is generated from the inductor. Until the predetermined conductive film reaches a film thickness corresponding to the skin depth by polishing, the magnetic flux induced in the predetermined conductive film passes through the region of the skin depth substantially parallel along the film surface. . When polishing progresses and the predetermined conductive film reaches a film thickness that is equal to or near the skin depth, leakage magnetic flux penetrating through the predetermined conductive film begins to be generated. This change in magnetic flux changes the amount of eddy current induced in the predetermined conductive film by electromagnetic induction. As the film thickness decreases, the leakage magnetic flux penetrating through the film increases, so that the eddy current induced gradually increases. Due to the eddy current generated in this wide area, a large mutual inductance is generated in the predetermined conductive film. This mutual inductance acts to reduce the self-inductance of the sensor circuit system in the high-frequency inductor type sensor. Thus, initially, even if the conductive film thickness is decreased, a constant eddy current is formed when the magnetic flux applied to the conductive film film is not penetrated through the wafer. Thereafter, when the film thickness is further decreased to be equal to or less than the film thickness corresponding to the skin depth, a magnetic flux is generated in which a part of the magnetic flux penetrates the conductive film on the wafer and leaks to the back surface of the wafer. At this time, the eddy current induced in the film increases as the leakage magnetic flux increases. Next, although the eddy current formed on the wafer surface increases to a certain thickness, the conductive film itself that generates the eddy current decreases as the conductive film is further removed. The current decreases. As a result, in spite of the monotonous film thickness reduction process, the eddy current increases once as the penetration flux increases, and then the volume itself that generates the eddy current decreases as the film thickness further decreases. Therefore, a maximum point appears in the mutual inductance corresponding to the induced eddy current. Due to the rapid decrease of the eddy current, the mutual inductance also decreases rapidly, and the inductance of the sensor circuit system starts to increase. In this way, eddy current is generated after the predetermined conductive film has reached a film thickness equivalent to or near the skin depth due to the progress of polishing, and then the inductance of the sensor circuit system temporarily decreases due to the rapid decrease thereafter. After that, it starts to increase. Due to this behavior, the change in the waveform of the resonance frequency oscillated from the high-frequency inductor type sensor is noticeable due to the skin effect. Then, during this waveform change process, a waveform change portion for predicting the polishing end point is detected, and the polishing end point is predicted from the waveform change portion.

Since this peak appears at a film thickness corresponding to the skin depth, there is no problem that the threshold setting due to the overall shift of the induced eddy current amount as described above fluctuates. A peak appears at a position corresponding to the film thickness. In particular, when the conductive film is, for example, Cu, a peak appears in the vicinity of 710% of the remaining film of Cu. In the case of the W film, a peak appears at 2500 mm where the remaining film of W is a little thicker. This film thickness is different from the actual skin depth, but is a numerical value corresponding to the skin depth. The skin depth δ indicates that the electromagnetic wave intensity is 1 /
This is an index that conveniently indicates the depth of e, but this peak position is determined by the conductivity, magnetic permeability, frequency to be applied, etc. ing. The present invention is a technique achieved by skillfully utilizing a unique phenomenon that appears due to the skin effect of this material. In particular, since the wiring material has high conductivity in the CMP of the wiring material, the peak position appears as a sharp peak (maximum point) relatively near the end point (710 mm). Therefore, robust end point detection and end point prediction can be performed without being shaken by various disturbances.

  Further, the inductor type sensor does not monitor the film thickness by intentionally positively generating an eddy current in the film. In the conventional known sensor, the sensor coil is formed so as to have directivity so as to give a magnetic field that penetrates the conductive film. However, in the inductor type sensor according to the present invention, a planar inductor is used. Yes. Thus, the inductor is not intended to give directivity to the magnetic field but to appropriately diverge the magnetic field with respect to the conductive film so as not to penetrate deeply into the conductive film. This is because if the magnetic field penetrates deeply, or if a strong magnetic field is applied to deeply penetrate the magnetic field, the internal wiring may be locally overheated by eddy currents, electromigration, etc. This is because the wire breaks. Therefore, the planar inductor has an appropriate magnetic flux distribution that does not penetrate the conductive film as much as possible, in other words, does not generate an eddy current that damages the element. Further, when the conductive film is thinned just before the conductive film is removed, even if a magnetic field that causes a moderate divergence is applied, a magnetic flux that partially penetrates the conductive film appears. The rapid change that appears when the state of the thin conductive film near the end point is reached is monitored. Therefore, the algorithm for detecting the frequency, the inductor, and its signal is configured to maximize the inflection point near the end point.

  According to a second aspect of the present invention, the method for detecting a magnetic flux change portion due to the skin effect detects a peak apex, an inflection point, a rate of change increase, a rise change amount, and a change specific to the skin effect at the rise start point. Provided is a method for predicting and detecting the end of polishing.

  According to this configuration, the magnetic flux change portion due to the skin effect is executed by detecting a peak specific to the magnetic flux change, an inflection point, an increase rate of the change, an increase amount of change, and a change specific to the skin effect at the start of the increase. Is done.

  According to a third aspect of the present invention, there is provided a method for detecting a magnetic flux change portion due to the skin effect, wherein a characteristic change peculiar to the skin effect such as a waveform peak point, an inflection point, a predetermined increase rate point is detected. Provide a prediction / detection method.

  According to this configuration, the magnetic flux change portion due to the skin effect is executed by detecting changes specific to the skin effect such as a waveform peak point, an inflection point, and a predetermined rate of increase.

  According to a fourth aspect of the present invention, there is provided a method for predicting and detecting a polishing end point, wherein the high-frequency inductor type sensor close to the conductive film is a two-dimensional planar inductor.

According to this configuration, in the conventional three-dimensionally formed inductor, the directivity for allowing the magnetic flux to penetrate in the vertical direction with respect to the conductive film is improved, and the magnetic flux enters the inside of the device wafer. In some cases, internal wiring was disconnected due to electromigration. On the other hand, according to the method using the two-dimensional planar inductor, the magnetic flux with respect to the conductive film diverges moderately and does not have directivity, so that the magnetic flux does not actively enter the conductive film. Further, when the applied frequency is higher than 30 MHz, the magnetic flux cannot penetrate further into the conductive film due to the skin effect. Therefore, disconnection due to Joule heat due to generation of eddy current inside the device wafer or electrolysis due to excessive current. It becomes possible to prevent migration. In addition, when the film thickness of the surface conductive film is just being removed, a part of the magnetic flux penetrates the conductive film and forms an eddy current. Since the waveform change corresponding to the remarkably mutual inductance is generated when it becomes, it becomes possible to detect the end point of polishing.

  According to a fifth aspect of the present invention, there is provided a method for predicting and detecting the end of polishing, wherein the high-frequency inductor sensor adjacent to the conductive film is configured by attaching a conductive film to the surface of a substrate formed of an insulator. To do.

  According to this configuration, a sensor can be easily and inexpensively manufactured by depositing or applying a conductive material such as Cu on an insulating substrate such as glass / epoxy or paper / phenol such as a printed circuit board. It becomes possible. Compared to the method using windings, the conductive film is applied and then etched and manufactured, making it possible to manufacture with a very fine line width, and the sensor itself is very small. It becomes possible to become. By miniaturizing the sensor, even smaller magnetic fields can be generated efficiently, and the change behavior near the end point where the film is removed can be detected accurately without penetrating the magnetic field deeply into the conductive material. It becomes possible. In addition, the downsizing of the sensor makes it possible to arrange a large number of sensors corresponding to the position in the wafer surface, so that it is possible to accurately detect the uniformity of polishing in the wafer surface.

  According to a sixth aspect of the present invention, the change in magnetic flux induced based on the skin effect of the predetermined conductive film is measured by measuring eddy current in the predetermined conductive film, Measurement of mutual inductance generated by generating current, measurement of change in inductance of sensor circuit system in the high frequency inductor type sensor due to mutual inductance of the predetermined conductive film, or change of inductance of the sensor circuit system in the high frequency inductor type Provided is a method for predicting and detecting a polishing end point, which is at least one of measurements based on a change in resonance frequency oscillated by a sensor.

  According to this configuration, the monitoring of the change in magnetic flux induced based on the skin effect of the predetermined conductive film is specifically performed by eddy current, mutual inductance, inductance of the sensor circuit system, or By measuring the change in at least one of the resonance frequencies oscillated by the high-frequency inductor sensor, the portion of the waveform change before the polishing end point where the magnetic flux penetrating the predetermined conductive film increases as the polishing progresses. Clearly detected.

  According to the seventh aspect of the present invention, the polishing is completed in which an oscillator for oscillating the high-frequency inductor type sensor and a frequency counter for monitoring a change in the oscillation (resonance) frequency are arranged close to the high-frequency inductor type sensor. Provide a method for predicting and detecting time.

  According to this configuration, a distributed constant circuit is formed with conventional wiring and connection portions to prevent the inductance and capacitance of the circuit from becoming unnecessarily large. For example, a change due to capacitance is predominantly detected. Therefore, it is possible to accurately detect a change in magnetic flux caused near the inductor type sensor. Preferably, the oscillator and the frequency counter are in the same package as the inductor type sensor. In addition, in the normal band of several tens of MHz, a distributed constant circuit is formed, and electrostatic coupling occurs between the path and the sample rather than a change in magnetic flux, and the function as an electrostatic coupling sensor becomes dominant. However, according to this configuration, even if the frequency band is several tens of MHz, since the frequency monitor is arranged in the vicinity, the region to be electrostatically coupled is limited. Therefore, even in the tens of MHz band, rather than a distributed constant circuit, a conductive material that functions as a lumped circuit with a relatively constant capacitance and inductance, and that acts as a reaction due to the magnetic flux that the inductor exerts on the conductive material. It becomes possible to accurately detect a change in mutual inductance given to the inductor.

  According to the eighth aspect of the present invention, the magnetic flux change induced by the skin effect of the predetermined conductive film, the eddy current change, the mutual inductance change and the resonance frequency change are caused by the penetration magnetic flux as the film thickness decreases. A method for predicting and detecting the end point of polishing is provided, which includes a change due to an increase in thickness and a change due to a substantial decrease in the eddy current formation region as the film thickness subsequently decreases.

  According to this configuration, when the predetermined conductive film becomes less than the film thickness corresponding to the skin depth due to the progress of polishing, the eddy current and the mutual inductance increase with the increase of the penetrating magnetic flux, and the mutual inductance increases. As a result, the inductance of the sensor circuit system decreases and the resonance frequency increases. Thereafter, as the film thickness decreases due to further polishing, the eddy current formation region substantially decreases, the eddy current and the mutual inductance each decrease rapidly, and the inductance of the sensor circuit system increases rapidly, and the resonance frequency increases. Decreases rapidly. Due to these behaviors, after the predetermined conductive film has a film thickness corresponding to the skin depth, significant changes appear in the waveforms of eddy current, mutual inductance, and resonance frequency. Using such a waveform change, a waveform change portion for predicting the polishing end point is detected during the waveform change process.

  The invention according to claim 9 is a prediction / detection method of a polishing end point in which the conductive film is polished and a polishing end point is predicted and detected when the predetermined conductive film is properly removed. The inductor in the high-frequency inductor type sensor is brought close to the predetermined conductive film, and the magnetic flux penetrating through the conductive film to be polished increases as the film thickness decreases due to the polishing process. Select the inductor shape and frequency band that increases the inductance, monitor the magnetic flux change induced in the predetermined conductive film by the magnetic flux formed by the inductor, and the film thickness during polishing is noticeable due to the skin effect In the magnetic flux change process, a magnetic flux change portion for predicting the polishing end time is detected during the magnetic flux change process, and the polishing end time is predicted from the magnetic flux change portion. To provide a prediction and detection methods of the time.

  According to this configuration, the skin depth in the predetermined conductive film is determined depending on the material of the predetermined conductive film and the oscillation frequency of the high-frequency inductor type sensor. The oscillation frequency is selected so that the skin depth is smaller than the initial film thickness of the predetermined conductive film and larger than the predetermined film thickness at the end of polishing, and the film thickness is reduced. By forming the inductor shape so that the penetrating magnetic flux increases, the magnetic flux induced in the predetermined conductive film at the initial stage of polishing passes through the region of the skin depth substantially parallel along the film surface, and the polishing is performed. When the predetermined conductive film becomes less than the film thickness corresponding to the skin depth by the progress, a penetrating magnetic flux penetrating the conductive film to be polished is generated, and the eddy current and the mutual inductance increase as the penetrating magnetic flux increases. Thereafter, the eddy current formation region is substantially reduced as the film thickness is reduced by further polishing, and the eddy current and the mutual inductance are rapidly reduced. From these behaviors, after the predetermined conductive film reaches a film thickness corresponding to the skin depth, a magnetic flux change portion for predicting the polishing end point is detected.

  The invention according to claim 10 provides a method for predicting / detecting the end point of polishing in which the selected frequency band is 20 MHz or more when the material of the predetermined conductive film is Cu.

  According to this configuration, the frequency band oscillated from the high frequency inductor type sensor is specifically set to 20 MHz or more in the case of Cu, so that the skin depth is equal to the initial film thickness of the predetermined conductive film. And is set to be smaller than the initial film thickness of the predetermined conductive film and larger than the predetermined conductive film at the end of polishing.

The invention according to claim 11 is a method for predicting and detecting a polishing end time by polishing a conductive film and predicting and detecting a polishing end time when the predetermined conductive film is properly removed. An inductor in a high-frequency inductor type sensor is brought close to the predetermined conductive film, and at least a part of the magnetic flux formed by the inductor in the initial stage of polishing is caused by the skin effect of the predetermined conductive film. A frequency that does not penetrate the conductive film is oscillated from the high-frequency inductor type sensor, and at least once the magnetic flux that penetrates the conductive film increases as the polishing progresses. Changes in leakage magnetic flux penetrating the predetermined conductive film during polishing are monitored during polishing, and the film thickness during polishing is notably represented by the skin effect. The leakage flux change portion for predicting the polishing end point in the leakage flux change process is detected in the leakage flux change process, and the polishing end point is predicted from the leakage flux change portion. A detection method is provided.

  According to this configuration, the skin effect is such that the magnetic flux formed by the inductor hardly penetrates the predetermined conductive film at the initial stage of polishing, and leakage magnetic flux penetrating the predetermined conductive film starts to occur as the polishing proceeds. The frequency oscillated from the high-frequency inductor type sensor is set so as to occur. Then, after the predetermined conductive film has reached a film thickness corresponding to the skin depth due to the progress of polishing, the change in leakage magnetic flux that is noticeable due to the skin effect is utilized, and the polishing is completed during the leakage magnetic flux change process. A leakage magnetic flux change portion for predicting the time point is detected, and the polishing end time is predicted from the leakage magnetic flux change portion.

The invention according to claim 12 is a method for predicting and detecting a polishing end point by polishing a conductive film and predicting and detecting a polishing end point when the predetermined conductive film is properly removed.
An inductor in a high-frequency inductor type sensor is brought close to the predetermined conductive film, and a change in magnetic flux induced in the predetermined conductive film by a magnetic flux formed by the inductor is monitored. Using the magnetic flux change that appears prominently due to the skin effect determined by the material of the conductive film as a factor, the magnetic flux change portion for detecting the polishing end point is detected during the magnetic flux change process, and polishing is performed from the magnetic flux change portion. Provided is a method for predicting and detecting a polishing end point, wherein the end point is predicted.

  According to this configuration, the frequency oscillated from the high-frequency inductor type sensor is set in the same manner as the action of the invention according to the ninth aspect, and from the inductor, depending on the shape, a predetermined conductive film is formed at the initial stage of polishing. Due to the skin effect, a non-directional magnetic field is generated so as not to penetrate the predetermined conductive film. Then, the change in leakage magnetic flux generated as the polishing progresses is monitored as a change in eddy current, and the polishing end point is determined during the eddy current change process in which a predetermined conductive film is remarkably expressed by the skin effect as the polishing progresses. An eddy current change portion for prediction is detected, and the polishing end point is predicted from the eddy current change portion.

  According to a thirteenth aspect of the present invention, with respect to a method for predicting a polishing end point from a waveform change portion due to the skin effect, prediction / detection of a polishing end point at which polishing ends after polishing for a preset polishing time from the waveform change portion. Provide a method.

  According to this configuration, the waveform change portion for predicting the polishing end point is detected during the waveform change process that is noticeable due to the skin effect, and from the polishing rate to be executed after the detection, the waveform change portion is detected. The required polishing time can be set in advance. Therefore, after the waveform change portion is detected, the polishing is completed by polishing for the preset polishing time.

  The invention according to claim 14 is characterized in that the waveform change portion is a peak specific point, an inflection point, an increase rate of change, an increase change amount, and a change specific to the skin effect of the increase start point. Provide a method for predicting and detecting

  According to this configuration, the waveform change portion is detected from the peak peak of the waveform change, the inflection point, the rate of change increase, the amount of increase change, and the start of the increase, and the polishing end point is predicted from the waveform change portion. Is done.

  The invention according to claim 15 relates to a predictive detection method from the waveform change portion due to the skin effect to the end of polishing, from the time when the waveform change portion is reached from the initial stage of polishing and the polishing amount up to the waveform change portion. The remaining polishing time required from the waveform changing portion to the end of polishing is calculated by dividing the film thickness of the waveform changing portion by the polishing rate, and the waveform changing portion calculates the polishing rate. Provided is a method for predicting / detecting a polishing end point as a polishing end point after polishing for a calculated time.

  According to this configuration, the polishing rate between the time when the waveform change portion is detected from the initial stage of polishing and the amount of polishing until the waveform change portion is reached is calculated. Then, the required polishing time after detection of the waveform change portion is calculated by dividing the film thickness corresponding to the waveform change portion by the polishing rate. Therefore, after detecting the waveform change portion, polishing is completed by polishing for the calculated polishing time.

  The invention according to claim 16 is a method for predicting / detecting a polishing end point by polishing a conductive film and predicting and detecting a polishing end point when the predetermined conductive film is properly removed. An inductor in a high-frequency inductor type sensor is brought close to the predetermined conductive film, and at least a part of the magnetic flux formed by the inductor in the initial stage of polishing is caused by the skin effect of the predetermined conductive film. An inductor shape that generates a non-directional magnetic field that does not penetrate the conductive film and a frequency that does not penetrate the conductive film due to the skin effect are oscillated from the high-frequency inductor type sensor, and the at least a part of the at least a part as polishing progresses The magnetic flux penetrating through the conductive film is increased at least once, and the predetermined magnetic flux is formed during the polishing of the magnetic flux formed by the inductor. A change in eddy current caused by a change in leakage magnetic flux penetrating the conductive film is monitored as a change in mutual inductance generated in the inductor by the eddy current, and the film thickness during polishing is equal to the skin depth associated with the skin effect or A method for predicting and detecting a polishing end time by detecting a change portion of a mutual inductance for predicting a polishing end time based on a change in the mutual inductance when the vicinity is reached, and predicting a polishing end time from the changed portion. I will provide a.

  According to this configuration, the frequency oscillated from the high-frequency inductor type sensor is set in the same manner as the action of the invention according to the ninth aspect, and from the inductor, depending on the shape, a predetermined conductive film is formed at the initial stage of polishing. Due to the skin effect, a non-directional magnetic field is generated so as not to penetrate the predetermined conductive film. Then, a change in leakage magnetic flux generated with the progress of polishing is monitored as a change in mutual inductance generated in the inductor, and after the predetermined conductive film has reached a film thickness corresponding to the skin depth by the progress of polishing, A change portion of the mutual inductance for predicting the polishing end time is detected based on the change of the mutual inductance, and the polishing end time is predicted from the change portion of the mutual inductance.

The invention according to claim 17 is a method for predicting / detecting a polishing end point by polishing a conductive film and predicting and detecting a polishing end point when the predetermined conductive film is properly removed. An inductor in a high-frequency inductor type sensor is brought close to the predetermined conductive film, and at least a part of the magnetic flux formed by the inductor in the initial stage of polishing is caused by the skin effect of the predetermined conductive film. An inductor shape that generates a non-directional magnetic field that does not penetrate the conductive film and a frequency that does not penetrate the conductive film due to the skin effect are oscillated from the high-frequency inductor type sensor, and the at least part of the inductor shape as the polishing progresses. The magnetic flux penetrating through the conductive film is increased at least once, and the predetermined magnetic flux is formed during the polishing of the magnetic flux formed by the inductor. The change in inductance of the sensor circuit system in the high-frequency inductor type sensor based on the change in leakage magnetic flux penetrating the conductive film is monitored as the change in resonance frequency determined by the inductance and the specific capacitance of the sensor circuit system. Based on the change in the resonance frequency when the film thickness becomes a film thickness corresponding to the skin effect, the change part of the resonance frequency for predicting the polishing end point is detected, and the polishing is finished from the change part of the resonance frequency. Provided is a method for predicting and detecting a polishing end point for predicting a point in time.

  According to this configuration, the frequency oscillated from the high-frequency inductor type sensor is set in the same manner as the operation of the invention according to the tenth aspect. In addition, due to the shape of the inductor, a magnetic field having no directivity that does not penetrate the predetermined conductive film is generated at the initial stage of polishing due to the skin effect of the predetermined conductive film. A leakage magnetic flux penetrating a predetermined conductive film is generated. Then, the change in inductance of the sensor circuit system in the high-frequency inductor type sensor due to the change in the leakage magnetic flux is monitored as a change in the resonance frequency determined by the inductance and the specific capacitance of the sensor circuit system. A change portion of the resonance frequency is detected based on the change of the resonance frequency after the characteristic film reaches a film thickness corresponding to the skin depth, and a polishing end point is predicted from the change portion of the resonance frequency.

  The invention according to claim 18 is a method for predicting and detecting a polishing end time by polishing a conductive film and predicting and detecting a polishing end time when the predetermined conductive film is properly removed. An inductor in a high-frequency inductor type sensor is brought close to the predetermined conductive film, and at least a part of the magnetic flux formed by the inductor in the initial stage of polishing is caused by the skin effect of the predetermined conductive film. An inductor shape that generates a non-directional magnetic field that does not penetrate the conductive film and a frequency that does not penetrate the conductive film due to the skin effect are oscillated from the high-frequency inductor type sensor, and the at least part of the inductor shape as the polishing progresses. The magnetic flux penetrating through the conductive film is increased at least once, and the predetermined magnetic flux is formed during the polishing of the magnetic flux formed by the inductor. Sensor circuit system in the high-frequency inductor type sensor based on a change in eddy current caused by a change in leakage magnetic flux penetrating the conductive film, a change in mutual inductance generated in the inductor due to the change in eddy current, or a change in mutual inductance Monitoring at least one of the changes in the resonance frequency oscillated from the high-frequency inductor type sensor due to the change in inductance, and when the film thickness during polishing becomes a film thickness corresponding to the skin effect Based on at least one of the changes, a change part of the resonance frequency for predicting the polishing end point is detected, and a polishing end point is predicted and detected by predicting the polishing end point from the change part of the resonance frequency. Provide a method.

  According to this configuration, the frequency oscillated from the high-frequency inductor type sensor is set in the same manner as the operation of the invention according to the tenth aspect. In addition, due to the shape of the inductor, a magnetic field having no directivity that does not penetrate the predetermined conductive film is generated at the initial stage of polishing due to the skin effect of the predetermined conductive film. A leakage magnetic flux penetrating a predetermined conductive film is generated. And at least one of a change in eddy current caused by the change in the leakage magnetic flux, a change in mutual inductance accompanying the change in the eddy current, or a change in resonance frequency oscillated from the high-frequency inductor type sensor based on the change in mutual inductance. Any change is monitored, and the change of the eddy current, the change of mutual inductance, or the change of resonance frequency after the predetermined conductive film becomes a film thickness corresponding to the skin depth by the progress of polishing. A change portion of the resonance frequency is detected based on at least one change, and a polishing end point is predicted from the change portion of the resonance frequency.

  According to the nineteenth aspect of the present invention, during each change in the eddy current, the mutual inductance, or the resonance frequency when the film thickness of the predetermined conductive film being polished reaches a film thickness corresponding to the skin depth. Is caused by two phenomena: an increase in eddy current due to the increase in leakage flux generated at the film thickness corresponding to the skin depth and a decrease in eddy current formation region due to a decrease in film thickness volume due to polishing. Provided is a method for predicting and detecting a polishing end point in which a point (peak) is generated and the above-mentioned changed portion is detected based on the maximum point (peak).

According to this configuration, in addition to the effect of the invention of claim 17, the eddy current, the mutual inductance, or the resonance frequency after the predetermined conductive film becomes a film thickness corresponding to the skin depth by the progress of polishing. A maximum point (peak) occurs during each change. Based on this maximum point (peak), a change portion of the waveform for predicting the polishing end time is detected, and the polishing end time is predicted from the change portion.

  The invention according to claim 20 is a real-time film thickness monitoring method for polishing a conductive film and monitoring a change in film thickness during polishing for evaluating whether or not the predetermined conductive film is properly removed. Then, an inductor in a high-frequency inductor sensor is brought close to the predetermined conductive film, and at least a part of the magnetic flux formed by the inductor in the initial stage of polishing is caused by the skin effect of the predetermined conductive film. Oscillates from the high-frequency inductor type sensor at a frequency that does not penetrate the conductive film, and has a process of increasing the magnetic flux penetrating the at least part of the conductive film at least once during polishing, as the polishing proceeds, Changes in leakage magnetic flux penetrating through the predetermined conductive film during the polishing of the magnetic flux formed by the inductor are monitored. A change part of the leakage magnetic flux for predicting the polishing end point is detected from the change of the leakage magnetic flux when the film thickness corresponds to the effect, and the polishing rate and the remaining to be removed on the spot based on the change part. A real-time film thickness monitoring method for calculating the film thickness amount is provided.

  According to this configuration, the skin effect is such that the magnetic flux formed by the inductor hardly penetrates the predetermined conductive film at the initial stage of polishing, and leakage magnetic flux penetrating the predetermined conductive film starts to occur as the polishing proceeds. The frequency oscillated from the high-frequency inductor type sensor is set so as to occur. Then, a change portion for predicting the polishing end point is detected from the change in the leakage magnetic flux after the predetermined conductive film reaches a film thickness corresponding to the skin depth due to the progress of polishing, and based on the change portion. Each polishing data, such as the polishing rate, is calculated on the spot from the amount of residual film to be removed, which is almost equivalent to the skin depth, and the amount of film already removed by polishing and the required time. It is evaluated whether it has been removed.

  The invention according to claim 21 is a real-time film thickness monitoring method for polishing a conductive film and monitoring a change in film thickness during polishing for evaluating whether or not the predetermined conductive film is properly removed. Then, an inductor in a high-frequency inductor sensor is brought close to the predetermined conductive film, and at least a part of the magnetic flux formed by the inductor in the initial stage of polishing is caused by the skin effect of the predetermined conductive film. Oscillates from the high-frequency inductor type sensor at a frequency that does not penetrate the conductive film, and has a process of increasing the magnetic flux penetrating the at least part of the conductive film at least once during polishing, as the polishing proceeds, Of the magnetic flux formed by the inductor, the change of the leakage flux that penetrates the predetermined conductive film during the progress of polishing And detecting a change portion of the leakage magnetic flux for predicting the end point of polishing from the change of the eddy current when the film thickness during polishing becomes a film thickness corresponding to the skin effect. A real-time film thickness monitoring method for calculating the polishing rate and the remaining film thickness to be removed on the spot is provided.

  According to this configuration, the frequency oscillated from the high-frequency inductor type sensor is set in the same manner as the operation of the above-described invention. Then, the change in leakage magnetic flux is monitored as a change in eddy current, and the change portion is detected from the change in the eddy current after the predetermined conductive film becomes a film thickness corresponding to the skin depth by the progress of polishing, Each polishing data such as the polishing rate is calculated on the spot from the amount of the remaining film to be removed, which is substantially equivalent to the skin depth based on the changed portion, the amount of film thickness already removed by polishing, and the required time. It is evaluated whether the conductive film is properly removed.

The invention according to claim 22 is a real-time film thickness monitoring method for polishing a conductive film and monitoring a change in film thickness during polishing for evaluating whether or not the predetermined conductive film is properly removed. Then, an inductor in a high-frequency inductor sensor is brought close to the predetermined conductive film, and at least a part of the magnetic flux formed by the inductor in the initial stage of polishing is caused by the skin effect of the predetermined conductive film. Oscillates from the high-frequency inductor type sensor at a frequency not penetrating the conductive film, and has a process of increasing the magnetic flux penetrating the at least part of the conductive film as the polishing proceeds, at least once during polishing, Of the magnetic flux formed by the inductor, a change in eddy current caused by a change in leakage magnetic flux penetrating the predetermined conductive film during polishing is converted into the eddy current. The mutual inductance for monitoring the change of the mutual inductance generated in the inductor and predicting the end point of the polishing from the change of the mutual inductance when the film thickness during polishing reaches the film thickness corresponding to the skin effect. Provided is a real-time film thickness monitoring method for detecting a changed portion and calculating a polishing rate and a remaining film thickness to be removed on the spot based on the changed portion.

  According to this configuration, the frequency oscillated from the high-frequency inductor type sensor is set in the same manner as the operation of the above-described invention. Then, a change in leakage magnetic flux is monitored as a change in mutual inductance generated in the inductor, and polishing is completed from a change in the mutual inductance after the predetermined conductive film reaches a film thickness corresponding to the skin depth by the progress of polishing. A change part of mutual inductance for predicting the time point is detected, and based on the change part, polishing is performed based on the remaining film amount to be removed, which is substantially equal to the skin depth, and the film thickness amount already removed by polishing and the required time. Each polishing data such as a rate is calculated on the spot, and it is evaluated whether or not a predetermined conductive film is properly removed.

  The invention according to claim 23 is a real-time film thickness monitoring method for polishing a conductive film and monitoring a change in film thickness during the polishing for evaluating whether or not the predetermined conductive film is properly removed. Then, an inductor in a high-frequency inductor sensor is brought close to the predetermined conductive film, and at least a part of the magnetic flux formed by the inductor in the initial stage of polishing is caused by the skin effect of the predetermined conductive film. Oscillates from the high-frequency inductor type sensor at a frequency not penetrating the conductive film, and has a process of increasing the magnetic flux penetrating the at least part of the conductive film as the polishing proceeds, at least once during polishing, Of the magnetic flux formed by the inductor, the high-frequency inductor type sensor based on a change in leakage magnetic flux that penetrates the predetermined conductive film during polishing. The change in the inductance of the sensor circuit system is monitored as a change in the resonance frequency determined by the inductance and the specific capacitance of the sensor circuit system, and the film thickness during polishing becomes a film thickness corresponding to the skin effect. A real-time film thickness monitor that detects a change portion of the resonance frequency for predicting the polishing end point from the change of the resonance frequency, and calculates the polishing rate and the remaining film thickness to be removed on the spot based on the change portion. Provide a method.

  According to this configuration, the frequency oscillated from the high-frequency inductor type sensor is set in the same manner as the operation of the above-described invention. Then, the change in inductance of the sensor circuit system in the high-frequency inductor type sensor due to the change in the leakage magnetic flux is monitored as a change in resonance frequency determined by the inductance and the specific capacitance of the sensor circuit system. A change portion of the resonance frequency for predicting the end point of polishing is detected from the change of the resonance frequency after the film has reached a film thickness corresponding to the skin depth, and is almost equal to the skin depth based on the change portion. Each polishing data such as the polishing rate is calculated on the spot from the amount of the remaining film to be removed, the film thickness already removed by polishing, and the required time to evaluate whether the predetermined conductive film is properly removed. Is done.

According to a twenty-fourth aspect of the present invention, during each change in the eddy current, the mutual inductance, or the resonance frequency when the film thickness of the predetermined conductive film being polished is equal to or near the skin depth. The skin effect causes a peak due to the action of two phenomena: an increase in eddy current due to the increase in leakage magnetic flux and a decrease in eddy current due to a decrease in film thickness volume due to polishing, and polishing is performed based on the peak. Provided is a real-time film thickness monitoring method in which a change portion for predicting an end point is detected.

  According to this configuration, in addition to the effect of the invention of claim 20, 21 or 22, the eddy current and the mutual inductance after the predetermined conductive film becomes a film thickness corresponding to the skin depth by the progress of polishing. Or peaks during each change in resonant frequency. Based on this peak, a change portion for predicting the polishing end point is detected.

  The invention described in claim 25 has a high-frequency inductor type sensor provided with an oscillation circuit constituting a sensor circuit system composed of a planar inductor and a capacitor, and the conductive film is polished to properly remove the predetermined conductive film. An apparatus for predicting and detecting a polishing end point for predicting and detecting a polishing end point at the time when the polishing is completed, wherein: , 13, 14, 15, 16, 17 or 18 is provided. A polishing end point prediction / detection device for executing the polishing end point prediction / detection method is provided.

  According to this configuration, the prediction / detection device at the end of polishing having a high-frequency inductor type sensor having an oscillation circuit that forms a sensor circuit system including a planar inductor and a capacitor has a skin depth in a predetermined conductive film, The oscillation frequency of the high-frequency inductor sensor is set to be smaller than the initial film thickness of the predetermined conductive film and larger than the film thickness of the predetermined conductive film at the end of polishing. As a result, the magnetic flux induced in the predetermined conductive film by the magnetic flux formed by the planar inductor in the initial stage of polishing passes through the skin depth region almost in parallel along the film surface, and as the polishing progresses. At least a part of the magnetic flux penetrates the predetermined conductive film, and leakage magnetic flux starts to be generated. Then, the change of the leakage magnetic flux during the progress of polishing, the change of the eddy current caused by the change of the leakage magnetic flux, the change of the mutual inductance generated in the planar inductor due to the change of the eddy current, or the change based on the change of the mutual inductance A change in the resonance frequency oscillated from the high-frequency inductor type sensor due to a change in the inductance of the sensor circuit system is monitored, and a predetermined conductive film corresponds to the skin depth as the polishing progresses A change portion before the polishing end point is detected based on at least one of the changes after the thickness is increased, and the polishing end point is predicted from the change portion.

  The invention described in claim 26 has a high-frequency inductor type sensor provided with an oscillation circuit that constitutes a sensor circuit system comprising a planar inductor and a capacitor, and the conductive film is polished to properly remove the predetermined conductive film. 24. A real-time film thickness monitoring device for monitoring a change in film thickness during the progress of polishing for evaluating whether or not the real-time film thickness monitoring method according to claim 19, 20, 21, 22, or 23 is executed. A thickness monitoring device is provided.

According to this configuration, the real-time film thickness monitoring apparatus having a high-frequency inductor type sensor having an oscillation circuit that forms a sensor circuit system including a planar inductor and a capacitor has a skin depth in a predetermined conductive film, The oscillation frequency of the high-frequency inductor sensor is set to be smaller than the initial film thickness of the conductive film and larger than the predetermined film thickness at the end of polishing. As a result, the magnetic flux induced in the predetermined conductive film by the magnetic flux formed by the planar inductor in the initial stage of polishing passes through the region of the skin depth almost in parallel along the film surface, and as the polishing progresses At least a part of the magnetic flux penetrates the predetermined conductive film, and leakage magnetic flux starts to be generated. Then, the change of the leakage magnetic flux during the progress of polishing, the change of the eddy current caused by the change of the leakage magnetic flux, the change of the mutual inductance generated in the planar inductor due to the change of the eddy current, or the change based on the change of the mutual inductance A film in which at least one of changes in the resonance frequency oscillated from the high-frequency inductor type sensor due to a change in inductance of the sensor circuit system is monitored, and a predetermined conductive film corresponds to the skin depth by the progress of polishing. A change portion before the polishing end point is detected from at least one of the changes after the thickness is reached, and a remaining film amount to be removed that is substantially equal to the skin depth based on the change portion; and Each polishing data, such as the polishing rate, is calculated on the spot based on the amount of film already removed by polishing and the required time, and the specified conductive film is removed appropriately. To assess if they were.

  According to the first aspect of the present invention, an inductor in a high-frequency inductor type sensor is brought close to a predetermined conductive film, and a change in magnetic flux induced in the predetermined conductive film by a magnetic flux formed by the inductor is monitored and polished. The magnetic flux change portion for predicting the polishing end time is detected based on the magnetic flux change due to the skin effect determined by the material of the predetermined conductive film as a factor, and the polishing end time is predicted from the changed portion. Therefore, at the initial stage of polishing, the magnetic flux induced in the predetermined conductive film passes through the region of the skin depth substantially in parallel along the film surface. Thereby, strong magnetic flux is not exerted to the fine wiring etc. which are formed in the film, and generation of eddy current is suppressed and Joule heat loss due to the eddy current can be minimized. After the predetermined conductive film reaches a thickness corresponding to the skin depth due to the progress of polishing, a leakage magnetic flux penetrating the predetermined conductive film is generated, and this leakage magnetic flux causes an eddy current in the predetermined conductive film. Is induced. This eddy current gradually increases due to an increase in leakage magnetic flux accompanying a decrease in film thickness, and rapidly decreases because the conductive film itself that generates eddy currents decreases due to a further decrease in film thickness. Due to this increase in eddy current and subsequent rapid decrease, the inductance of the sensor circuit system once decreases and then increases. This behavior causes a peak (inflection point) in the waveform of the resonance frequency oscillated from the high frequency inductor type sensor. The peak (inflection point) constantly appears at a position corresponding to the remaining film thickness without being shaken by various disturbances. For this reason, there exists an advantage that it can detect based on the said peak (inflection point), and can predict and detect a grinding | polishing completion time accurately from the said magnetic flux change part.

  According to the second aspect of the present invention, the method of detecting the magnetic flux change portion due to the skin effect is to detect the peak apex, the inflection point, the rate of change increase, the amount of increase change, and the change specific to the skin effect at the start point of increase. By doing so, prediction / detection at the end of polishing is performed extremely appropriately.

  According to a third aspect of the present invention, in the method for detecting a magnetic flux change portion due to the skin effect, a change peculiar to the skin effect such as a waveform peak point, an inflection point, and a predetermined increase rate point is detected. Prediction / detection is extremely appropriate.

  In the invention according to claim 4, since the high-frequency inductor type sensor close to the conductive film is a two-dimensional planar inductor, the magnetic flux formed by the two-dimensional planar inductor is moderately applied to a predetermined conductive film. Since it diverges and does not have directivity, it does not actively penetrate into the predetermined conductive film until the predetermined conductive film reaches a film thickness corresponding to the skin depth by the progress of polishing. In addition to this, the skin effect prevents magnetic flux from penetrating into the conductive film, so that it is possible to effectively prevent disconnection due to Joule heat due to eddy current generation inside the device wafer and electromigration due to excessive current. There is.

  In the fifth aspect of the invention, the high-frequency inductor type sensor close to the conductive film has a structure in which a conductive film is attached to the surface of a substrate formed of an insulator, so glass, epoxy, paper, phenol, etc. A sensor can be easily and inexpensively manufactured by depositing or applying a conductive material on the insulating substrate. Moreover, by forming a conductive film on an insulating substrate and then manufacturing it by etching or the like, it becomes possible to manufacture with a very fine line width, and the sensor itself can be made very small. . And by miniaturizing the sensor, a minute magnetic field can be generated efficiently, and the change behavior near the end point where the conductive film is removed can be accurately detected without deeply penetrating the magnetic field inside the conductive film. There is an advantage that you can.

According to a sixth aspect of the present invention, the change in magnetic flux induced based on the skin effect of the predetermined conductive film is measured by measuring eddy current in the predetermined conductive film, Measurement of mutual inductance generated by generating current, measurement of change in inductance of sensor circuit system in the high frequency inductor type sensor due to mutual inductance of the predetermined conductive film, or change in inductance of the sensor circuit system as the high frequency inductor type Since at least one of the measurement is performed by changing the resonance frequency at which the sensor oscillates, the change in the magnetic flux induced in the predetermined conductive film according to the first aspect of the invention is specifically monitored by the change in the magnetic flux. Eddy current, mutual inductance, inductance of sensor circuit system, or resonance frequency at which high frequency inductor type sensor oscillates Chino By using at least one of change, there is an advantage that a changing portion of the resonant frequency for predicting polishing end point of the polishing endpoint before it can be more easily detected clearly.

  In the seventh aspect of the invention, an oscillator that oscillates the high-frequency inductor type sensor and a frequency counter for monitoring a change in the oscillation (resonance) frequency are disposed close to the high-frequency inductor type sensor. Conductivity brought about in the vicinity of the high-frequency inductor type sensor by forming a distributed constant circuit at the wiring / connection part between the oscillator that oscillates the high-frequency inductor type sensor and the frequency counter, etc. to prevent the inductance and capacitance from becoming unnecessarily large. There is an advantage that a change in magnetic flux accompanying the progress of film polishing can be accurately detected.

  According to the eighth aspect of the present invention, the magnetic flux change induced by the skin effect of the predetermined conductive film, the eddy current change, the mutual inductance change and the resonance frequency change are caused by the penetration magnetic flux as the film thickness decreases. The change due to the increase in thickness and the change due to the substantial decrease in the eddy current formation region with the subsequent decrease in film thickness are included. When the film thickness is less than or equal to the depth, the eddy current, the mutual inductance, and the resonance frequency increase as the penetrating magnetic flux increases. Thereafter, the eddy current formation region is substantially reduced as the film thickness is reduced by further polishing, and the eddy current, the mutual inductance, and the resonance frequency are rapidly reduced. These behaviors cause peaks (inflection points) in the eddy current, mutual inductance, and resonance frequency waveforms after the predetermined conductive film has reached a thickness corresponding to the skin depth. There is an advantage that the changed portion of the waveform can be clearly detected on the basis of the curved point.

  According to the ninth aspect of the present invention, the inductor in the high-frequency inductor sensor is brought close to a predetermined conductive film, and the magnetic flux penetrating through the conductive film to be polished increases as the film thickness decreases by the polishing process. Select the inductor shape and frequency band so that the mutual inductance induced in the conductive film increases, monitor the change in magnetic flux induced in the predetermined conductive film by the magnetic flux formed by the inductor, Since the magnetic flux change portion for predicting the polishing end point is detected based on the magnetic flux change caused by the skin effect, the polishing end point is predicted from the magnetic flux change portion. The magnetic flux induced in the conductive film passes through the skin depth region almost in parallel along the film surface, and the predetermined conductive film becomes a film thickness corresponding to the skin depth by the progress of polishing. In the following were, a conductive transmembrane flux is generated which penetrates, the eddy current and mutual inductance increases with increasing of the through flux. Thereafter, the eddy current formation region is substantially reduced as the film thickness is reduced by further polishing, and the eddy current and the mutual inductance are rapidly reduced. The magnetic flux change portion is detected from these behaviors, and there is an advantage that the polishing end point can be accurately predicted and detected from the change portion.

  In the invention according to claim 10, since the selected frequency band is set to 20 MHz or more when the material of the predetermined conductive film is Cu, the skin depth is determined when the material of the predetermined conductive film is Cu. Is smaller than the initial film thickness of the predetermined conductive film at the initial stage of polishing, and the conductive film reaches a thickness corresponding to the skin depth after the polishing finishes before the polishing end point. There is an advantage that a leakage magnetic flux penetrating the conductive film can be generated.

  According to an eleventh aspect of the present invention, an inductor in a high-frequency inductor type sensor is brought close to a predetermined conductive film, and at least a part of the magnetic flux formed by the inductor in the initial stage of polishing is generated by the predetermined conductive film. At least once a process in which at least a part of the magnetic flux penetrating through the conductive film is oscillated from the high-frequency inductor type sensor so as not to penetrate the predetermined conductive film due to the skin effect and as the polishing proceeds. And monitoring the change in leakage magnetic flux penetrating through the predetermined conductive film during the polishing of the magnetic flux formed by the inductor, and the film thickness during polishing changes the leakage magnetic flux associated with the skin effect. Based on the change of leakage magnetic flux to predict the end point of polishing based on the detection, and the end point of polishing is predicted from the changed portion. After the predetermined conductive film reaches a film thickness corresponding to the skin depth, a leakage magnetic flux penetrating the predetermined conductive film is generated, and the film thickness before the polishing end point is based on the change in the leakage magnetic flux. A reference point is detected. Therefore, there is an advantage that the polishing end point can be accurately predicted and detected from the changed portion of the leakage magnetic flux.

  According to a twelfth aspect of the present invention, an inductor in a high-frequency inductor type sensor is brought close to a predetermined conductive film, and at least a part of the magnetic flux formed by the inductor at the initial stage of polishing is generated by the predetermined conductive film. An inductor shape that generates a non-directional magnetic field that does not penetrate the predetermined conductive film due to the skin effect and a frequency that does not penetrate the conductive film due to the skin effect are oscillated from the high-frequency inductor type sensor, The magnetic flux penetrating the predetermined conductive film is increased at least once as it progresses, and the leakage magnetic flux penetrating the predetermined conductive film during the polishing is among the magnetic fluxes formed by the inductor. The change is monitored as a change in eddy current generated by the leakage magnetic flux, and the film thickness during polishing is equal to or near the skin depth associated with the skin effect. Since the change part of the leakage magnetic flux for predicting the polishing end time is detected based on the change of the eddy current in the case of becoming, and the polishing end time is predicted from the change part, the shape of the inductor is Thus, at the initial stage of polishing, a non-directional magnetic field that does not penetrate the predetermined conductive film is generated due to the skin effect of the predetermined conductive film, so that even fine wiring formed in the film is strong. Magnetic flux is not exerted, and generation of eddy current is suppressed, so that Joule heat loss due to the eddy current can be minimized. Then, after the predetermined conductive film reaches a film thickness corresponding to the skin depth due to the progress of polishing, a leakage magnetic flux penetrating the predetermined conductive film is generated, and a change in the eddy current accompanying the change of the leakage magnetic flux occurs. Based on the above, the eddy current change portion before the polishing end point is detected. Therefore, there is an advantage that the polishing end point can be accurately predicted and detected from the changed portion.

  The invention according to claim 13 relates to the method of predicting the polishing end point from the waveform change portion due to the skin effect, and the polishing is ended after polishing for a predetermined polishing time from the waveform change portion. The changed portion is detected when the remaining film amount becomes a film thickness corresponding to the skin depth. Therefore, the required polishing time after detecting the waveform change portion can be set in advance from the remaining film amount and the polishing rate to be executed after the waveform change portion is detected. Accordingly, there is an advantage that a predetermined conductive film can be properly polished and removed by polishing after a predetermined polishing time from the detected waveform change portion and finishing the polishing.

  In the invention described in claim 14, since the waveform change portion detects the peak apex, the inflection point, the change increase rate, the increase change amount, and the change effect peculiar to the skin effect of the increase start point, the polishing end point is determined. Predict with high accuracy.

The invention according to claim 15 relates to a predictive detection method from the waveform change portion due to the skin effect to the end of polishing, from the time when the waveform change portion is reached from the initial stage of polishing and the polishing amount up to the waveform change portion. The remaining polishing time required from the waveform changing portion to the end of polishing is calculated by dividing the film thickness of the waveform changing portion by the polishing rate, and the waveform changing portion calculates the polishing rate. After polishing for the calculated time, the end point of polishing is set. Therefore, by detecting the waveform change portion, the polishing rate between the time required for the detection and the polishing amount can be calculated. When performing polishing after detecting the waveform change portion with the polishing rate after detection of the waveform change portion being the same as the polishing rate before detection of the waveform change portion, it corresponds to the skin depth that is the amount of remaining film in the waveform change portion. The required polishing time after detecting the waveform change portion is calculated by dividing the film thickness by the polishing rate. Therefore, there is an advantage that the predetermined conductive film can be properly polished and removed by polishing for the calculated polishing time after detecting the waveform change portion.

  According to a sixteenth aspect of the present invention, an inductor in a high-frequency inductor type sensor is brought close to a predetermined conductive film, and at least a part of the magnetic flux formed by the inductor in the initial stage of polishing is generated by the predetermined conductive film. An inductor shape that generates a non-directional magnetic field that does not penetrate the predetermined conductive film due to the skin effect and a frequency that does not penetrate the conductive film due to the skin effect are oscillated from the high-frequency inductor type sensor, Leakage that penetrates the predetermined conductive film during the polishing process among the magnetic fluxes formed by the inductor at least once as the magnetic flux penetrating the at least part of the conductive film increases with progress. Changes in eddy current caused by changes in magnetic flux are monitored as changes in mutual inductance generated in the inductor by the eddy current. Based on the change of the mutual inductance when the film thickness during polishing is equal to or near the skin depth associated with the skin effect, the change portion of the mutual inductance for predicting the end point of polishing is detected, and the change Since the end point of the polishing is predicted from the portion, the magnetic field having no directivity that does not penetrate the predetermined conductive film due to the skin effect of the predetermined conductive film at the initial stage of polishing is determined from the inductor by the shape of the inductor. As a result of this, strong magnetic flux is not exerted even on fine wiring formed in the film, and generation of eddy current is suppressed, and Joule heat loss due to the eddy current can be minimized. Then, after the predetermined conductive film becomes a film thickness corresponding to the skin depth due to the progress of polishing, a leakage magnetic flux penetrating the predetermined conductive film is generated, and an eddy current associated with the change in the leakage magnetic flux is generated. A mutual inductance for predicting the polishing end point before the polishing end point is detected based on the change of the mutual inductance generated in the inductor due to the change. Therefore, there is an advantage that the polishing end point can be accurately predicted and detected from the changed portion.

  According to a seventeenth aspect of the present invention, an inductor in a high-frequency inductor type sensor is brought close to a predetermined conductive film, and at least a part of the magnetic flux formed by the inductor at the initial stage of polishing is generated by the predetermined conductive film. An inductor shape that generates a non-directional magnetic field that does not penetrate the predetermined conductive film due to the skin effect and a frequency that does not penetrate the conductive film due to the skin effect are oscillated from the high-frequency inductor type sensor, A leakage of penetrating through the predetermined conductive film during the polishing of the magnetic flux formed by the inductor at least once as the magnetic flux penetrating through the at least part of the conductive film increases with progress. The inductance change of the sensor circuit system in the high frequency inductor type sensor based on the change of magnetic flux The change in resonance frequency determined by the specific capacitance of the sensor circuit system is monitored, and the polishing end point is predicted based on the change in resonance frequency when the film thickness during polishing reaches the film thickness corresponding to the skin effect. Since the change portion of the resonance frequency for detecting the current value is detected and the polishing end point is predicted from the change portion, the predetermined value is obtained from the inductor by the shape of the inductor and the skin effect of a predetermined conductive film at the initial stage of polishing. By generating a non-directional magnetic field that does not penetrate through the conductive film, no strong magnetic flux is exerted on the fine wiring formed in the film, and the generation of eddy currents is suppressed. Joule heat loss due to eddy current can be minimized. Then, after the predetermined conductive film reaches a film thickness corresponding to the skin depth due to the progress of polishing, a leakage magnetic flux penetrating the predetermined conductive film is generated, and a sensor circuit system associated with a change in the leakage magnetic flux Based on the change in the resonance frequency oscillated from the high-frequency inductor type sensor due to the change in the inductance, the change portion of the resonance frequency for predicting the polishing end point before the polishing end point is detected. Therefore, there is an advantage that the polishing end point can be accurately predicted and detected from the changed portion.

  According to an eighteenth aspect of the present invention, an inductor in a high-frequency inductor type sensor is brought close to a predetermined conductive film, and at least a part of the magnetic flux formed by the inductor at the initial stage of polishing is generated by the predetermined conductive film. An inductor shape that generates a non-directional magnetic field that does not penetrate the predetermined conductive film due to the skin effect and a frequency that does not penetrate the conductive film due to the skin effect are oscillated from the high-frequency inductor type sensor, A leakage of penetrating through the predetermined conductive film during the polishing of the magnetic flux formed by the inductor at least once as the magnetic flux penetrating through the at least part of the conductive film increases with progress. Change in eddy current caused by change in magnetic flux, change in mutual inductance generated in the inductor due to change in eddy current, or The film thickness during polishing is monitored by monitoring at least one of the changes in the resonant frequency oscillated from the high-frequency inductor type sensor due to the change in inductance of the sensor circuit system in the high-frequency inductor type sensor based on the mutual inductance change. Detects a change portion for predicting the polishing end point based on at least one of the changes when the film thickness corresponds to the skin effect, and determines the polishing end point from the change portion. Since it was predicted, due to the shape of the inductor, a magnetic field with no directivity that does not penetrate the predetermined conductive film due to the skin effect of the predetermined conductive film at the initial stage of polishing is generated. There is no strong magnetic flux to the fine wiring formed in the film, and the generation of eddy currents is suppressed and They are possible to suppress the loss to a minimum. Then, after the predetermined conductive film reaches a thickness corresponding to the skin depth due to the progress of polishing, a leakage magnetic flux penetrating the predetermined conductive film is generated, and an eddy current accompanying the change of the leakage magnetic flux is generated. The change portion before the polishing end point is detected based on at least one of a change, a change in mutual inductance, and a change in the resonance frequency oscillated from the high frequency inductor type sensor. Therefore, there is an advantage that the polishing end point can be accurately predicted and detected from the changed portion.

  According to a nineteenth aspect of the present invention, during each change of the eddy current, the mutual inductance, or the resonance frequency when the film thickness of the predetermined conductive film being polished reaches a film thickness corresponding to the skin depth. Is caused by two phenomena: an increase in eddy current due to the increase in leakage magnetic flux generated at a film thickness corresponding to the skin depth and a decrease in eddy current formation region due to a decrease in film thickness due to polishing. Since a point (peak) is generated, and a change portion for predicting the polishing end point is detected based on the maximum point (peak), in addition to the effect of the invention of claim 17, further polishing is performed. Since a predetermined conductive film becomes a film thickness corresponding to the skin depth due to the progress of eddy current, a remarkable maximum point (peak) occurs during each change in eddy current, mutual inductance, or resonance frequency. Remarkable local maximum ( The change portion for predicting the polishing end point based on chromatography h) can be accurately detected. Therefore, there is an advantage that the polishing end point can be predicted and detected with higher accuracy from the changed portion.

According to a twentieth aspect of the present invention, an inductor in a high-frequency inductor type sensor is brought close to a predetermined conductive film, and at least a part of the magnetic flux formed by the inductor in the initial stage of polishing is generated by the predetermined conductive film. The high frequency inductor type sensor oscillates at a frequency not penetrating the predetermined conductive film due to the skin effect, and at least polishing a process in which the magnetic flux penetrating the at least a part of the conductive film increases as the polishing progresses. Once, the change in leakage magnetic flux penetrating through the predetermined conductive film during the progress of polishing among the magnetic flux formed by the inductor is monitored, and the film thickness during polishing corresponds to the skin effect The change portion of the leakage magnetic flux for predicting the end point of polishing is detected from the change of the leakage magnetic flux when the amount of the magnetic flux becomes, and the polishing rate is detected on the spot based on the change portion. Since the amount of remaining film thickness to be removed is calculated, the leakage through the predetermined conductive film after the predetermined conductive film becomes a film thickness corresponding to the skin depth due to the progress of polishing. A magnetic flux is generated, and the changed portion before the polishing end point is detected from the change in the leakage magnetic flux. Therefore, it is possible to accurately calculate on the spot each amount of polishing data such as the amount of remaining film to be removed and the polishing rate based on the changed portion, and accurately determine whether a predetermined conductive film is properly removed. There is an advantage that the Joule heat loss due to the eddy current generated by the leakage magnetic flux can be minimized while being evaluated.

  According to the invention of claim 21, an inductor in a high-frequency inductor type sensor is brought close to a predetermined conductive film, and at least a part of the magnetic flux formed by the inductor in the initial stage of polishing is generated by the predetermined conductive film. The high frequency inductor type sensor oscillates at a frequency not penetrating the predetermined conductive film due to the skin effect, and at least polishing a process in which the magnetic flux penetrating the at least a part of the conductive film increases as the polishing progresses. Once the magnetic flux formed by the inductor is monitored, a change in leakage magnetic flux penetrating the predetermined conductive film during polishing is monitored as a change in eddy current generated by the leakage magnetic flux, and the film being polished The change portion of the eddy current for predicting the end point of polishing is detected from the change of the eddy current when the thickness becomes a film thickness corresponding to the skin effect, and the change is detected. Since the polishing rate and the remaining amount of film thickness to be removed are calculated on the spot based on the part, after the predetermined conductive film becomes a film thickness corresponding to the skin depth due to the progress of polishing, A leakage magnetic flux penetrating a predetermined conductive film is generated, and the changed portion before the polishing end point is detected from a change in eddy current accompanying a change in the leakage magnetic flux. Therefore, it is possible to accurately calculate on the spot each amount of polishing data such as the amount of remaining film to be removed and the polishing rate based on the changed portion, and accurately determine whether a predetermined conductive film is properly removed. There is an advantage that it can be evaluated.

  According to a twenty-second aspect of the present invention, an inductor in a high-frequency inductor type sensor is brought close to a predetermined conductive film, and at least a part of the magnetic flux formed by the inductor at the initial stage of polishing is generated by the predetermined conductive film. The high frequency inductor type sensor oscillates at a frequency not penetrating the predetermined conductive film due to the skin effect, and at least polishing a process in which the magnetic flux penetrating the at least a part of the conductive film increases as the polishing progresses. Mutual inductance generated once by the eddy current in the inductor due to a change in leakage magnetic flux passing through the predetermined conductive film during the polishing of the magnetic flux formed by the inductor. Of the mutual inductance when the film thickness during polishing reaches a film thickness corresponding to the skin effect. Since the change part of the mutual inductance for predicting the polishing end point from the conversion is detected, the polishing rate and the remaining film thickness to be removed are calculated on the spot based on the change part. After the predetermined conductive film reaches a film thickness corresponding to the skin depth, a leakage magnetic flux penetrating the predetermined conductive film is generated, and is generated in the inductor due to a change in eddy current accompanying a change in the leakage magnetic flux. The change portion before the polishing end point is detected from the change in mutual inductance. Therefore, it is possible to accurately calculate on the spot each amount of polishing data such as the amount of remaining film to be removed and the polishing rate based on the changed portion, and accurately determine whether a predetermined conductive film is properly removed. There is an advantage that it can be evaluated.

According to a twenty-third aspect of the present invention, an inductor in a high-frequency inductor type sensor is brought close to a predetermined conductive film, and at least a part of the magnetic flux formed by the inductor at the initial stage of polishing is generated by the predetermined conductive film. The high frequency inductor type sensor oscillates at a frequency not penetrating the predetermined conductive film due to the skin effect, and at least polishing a process in which the magnetic flux penetrating the at least a part of the conductive film increases as the polishing progresses. A change in inductance of the sensor circuit system in the high-frequency inductor sensor based on a change in leakage magnetic flux penetrating through the predetermined conductive film during polishing in the magnetic flux formed by the inductor. And the change in resonance frequency determined by the specific capacitance of the sensor circuit system. A change portion of the resonance frequency for predicting the polishing end point is detected from the change of the resonance frequency when the film thickness corresponds to the skin effect, and the polishing rate and removal are performed on the spot based on the change portion. Since the amount of remaining film thickness to be calculated is calculated, a leakage magnetic flux penetrating through the predetermined conductive film is generated after the predetermined conductive film reaches a film thickness corresponding to the skin depth due to the progress of polishing. The change portion before the polishing end point is detected based on the change of the resonance frequency oscillated from the high frequency inductor type sensor due to the change of the inductance of the sensor circuit system accompanying the change of the leakage magnetic flux. Therefore, each polishing data such as the amount of remaining film to be removed from the changed portion and the polishing rate can be accurately calculated on the spot, and it is accurately evaluated whether or not the predetermined conductive film is properly removed. There is an advantage that you can.

  According to a twenty-fourth aspect of the present invention, during each change in the eddy current, the mutual inductance, or the resonance frequency when the film thickness of the predetermined conductive film being polished is equal to or near the skin depth. Is caused by the two effects of the skin effect, namely, an increase in eddy current due to the increase in leakage magnetic flux and a decrease in eddy current due to a decrease in film thickness due to polishing. Since the film thickness reference point is detected, in addition to the effect of the invention according to claim 20, 21 or 22, the predetermined conductive film has a film thickness corresponding to the skin depth as the polishing proceeds. Since a significant peak occurs during each change in eddy current, mutual inductance, or resonance frequency after the change, the change part for predicting the end point of polishing is accurately detected based on this significant peak. It can be. Accordingly, the polishing data such as the amount of remaining film to be removed and the polishing rate can be calculated on the spot more accurately on the basis of the changed portion, and it is possible to accurately determine whether or not the predetermined conductive film is properly removed. There is an advantage that can be evaluated.

  The invention described in claim 25 has a high-frequency inductor type sensor provided with an oscillation circuit that constitutes a sensor circuit system comprising a planar inductor and a capacitor, and the conductive film is polished to properly remove the predetermined conductive film. An apparatus for predicting and detecting a polishing end point for predicting and detecting a polishing end point at the time when the polishing is completed, wherein: , 13, 14, 15, 16, 17 or 18, the polishing end point prediction / detection method is executed, so that a high-frequency inductor type having an oscillation circuit constituting a sensor circuit system including a planar inductor and a capacitor is provided. The apparatus for predicting and detecting the end of polishing having a sensor generates a leakage magnetic flux penetrating through the predetermined conductive film after the predetermined conductive film has reached a film thickness corresponding to the skin depth due to the progress of polishing. , Resonance oscillated from a high-frequency inductor type sensor due to a change in leakage flux, a change in eddy current caused by a change in leakage flux, a change in mutual inductance generated in a planar inductor due to the change in eddy current, or a change in inductance of a sensor circuit system A waveform change portion for predicting the polishing end point before the polishing end point is detected based on at least one of the frequency changes. Therefore, there is an advantage that the polishing end point can be accurately predicted and detected from the waveform change portion, and the Joule heat loss due to the eddy current generated by the leakage magnetic flux can be minimized.

  The invention described in claim 26 has a high-frequency inductor type sensor provided with an oscillation circuit constituting a sensor circuit system composed of a planar inductor and a capacitor, and the conductive film is polished to properly remove the predetermined conductive film. 24. A real-time film thickness monitoring device for monitoring a change in film thickness during the progress of polishing for evaluating whether the real-time film thickness monitoring method according to claim 19, 20, 21, 22, or 23 is executed. Therefore, the real-time film thickness monitoring apparatus having a high-frequency inductor type sensor having an oscillation circuit that constitutes a sensor circuit system including a planar inductor and a capacitor is a film in which a predetermined conductive film corresponds to the skin depth as the polishing progresses. After the thickness is increased, a leakage magnetic flux penetrating the predetermined conductive film is generated, and the change of the leakage magnetic flux and the eddy current generated by the change of the leakage magnetic flux are generated. Polishing is completed from at least one of the following: change in mutual inductance generated in the planar inductor due to change in the eddy current, or change in resonance frequency oscillated from the high-frequency inductor type sensor due to change in inductance of the sensor circuit system A waveform change portion for predicting the end point of polishing before doting is detected. Therefore, it is possible to accurately calculate on the spot each polishing data such as the amount of remaining film to be removed and the polishing rate based on the waveform change portion, and to accurately determine whether a predetermined conductive film is properly removed. There is an advantage that Joule heat loss due to eddy current generated by the leakage magnetic flux can be minimized.

  While minimizing Joule heat loss due to eddy current, accurately predicting and detecting the end point of polishing, and accurately calculating the amount of remaining film to be removed, polishing rate, etc. on the spot, a given conductive film In order to achieve the purpose of accurately evaluating whether it is properly removed, the conductive film is polished to predict and detect the end point of polishing when the predetermined conductive film is properly removed A method for predicting and detecting an end point, wherein an inductor in a high-frequency inductor sensor is brought close to the predetermined conductive film, and a change in magnetic flux induced in the predetermined conductive film is monitored by a magnetic flux formed by the inductor And detecting a magnetic flux change portion for predicting the end point of polishing based on the magnetic flux change due to the skin effect in which the film thickness during polishing is determined by the material of the predetermined conductive film as a factor. It was achieved by predicting the polishing end point.

  Hereinafter, the method and apparatus for predicting and detecting the end point of polishing according to Embodiment 1 of the present invention will be described in detail with reference to the drawings. 1 is a perspective view of a chemical mechanical polishing apparatus in which a prediction / detection device at the end of polishing is incorporated, FIG. 2 is an enlarged longitudinal sectional view of a polishing head, and FIG. FIG. 4 is a partially cutaway schematic side view for explaining a state in which the prediction / detection device at the time of completion of polishing is incorporated in the polishing head. It is.

  First, the configuration of the prediction / detection method and apparatus at the end of polishing according to the present embodiment will be described from the configuration of a chemical mechanical polishing apparatus applied thereto. In FIG. 1, the chemical mechanical polishing apparatus 1 mainly includes a platen 2 and a polishing head 3. The platen 2 is formed in a disk shape, and a rotary shaft 4 is connected to the center of the lower surface thereof. The platen 2 rotates in the direction of arrow A when the motor 5 is driven. A polishing pad 6 is attached to the upper surface of the platen 2, and a slurry that is a mixture of an abrasive and a chemical is supplied onto the polishing pad 6 from a nozzle (not shown).

  As shown in FIG. 2, the polishing head 3 is mainly composed of a head body 7, a carrier 8, a retainer ring 9, a retainer ring pressing means 10, an elastic sheet 11, a carrier pressing means 16, and control means such as air. .

  The head body 7 is formed in a disk shape smaller than the platen 2, and a rotating shaft 12 (see FIG. 1) is connected to the center of the upper surface. The head body 7 is attached to the rotary shaft 12 and is driven by a motor (not shown) to rotate in the direction of arrow B in FIG.

  The carrier 8 is formed in a disc shape, and is disposed in the center of the head body 7. A dry plate 13 is provided between the center of the upper surface of the carrier 8 and the lower center of the head body 7, and rotation is transmitted from the head body 7 via the pins 14 and 14.

  An operating transformer main body 15a is fixed between the center lower part of the dry plate 13 and the center upper part of the carrier 8, and a core 15b of the operating transformer 15 is fixed to the center upper part of the carrier 8 and is not shown. A polishing state signal of a conductive film made of Cu or the like connected to the control unit and formed on the wafer W (lower side in FIG. 2) is output to the control unit.

  A carrier pressing member 16 a is provided on the peripheral edge of the upper surface of the carrier 8, and a pressing force is transmitted from the carrier pressing means 16 to the carrier 8 through the carrier pressing member 16 a.

An air outlet 19 for injecting air from the air float line 17 to the elastic sheet 11 is provided on the lower surface of the carrier 8. The air float line 17 is connected to an air supply pump 21 which is an air supply source through an air filter 20 and an automatic opening / closing valve V1. Air is blown out from the air outlet 19 by switching the automatic opening / closing valve V1.

  On the lower surface of the carrier 8, a hole 22 for blowing out vacuum and, if necessary, DIW (pure water) or air is formed. The suction of the air is performed by driving the vacuum pump 23, and an automatic opening / closing valve V2 is provided in the vacuum line 24. By switching the automatic opening / closing valve V2, vacuum and DIW are fed via the vacuum line 24. Is done.

  Air supply from the air float line 17, vacuum action from the vacuum line 24, DIW supply and the like are executed by command signals from the control unit.

  The carrier pressing means 16 is disposed at the peripheral edge of the central portion of the lower surface of the head main body 7 and applies a pressing force to the carrier pressing member 16a, thereby transmitting the pressing force to the carrier 8 coupled thereto. The carrier pressing means 16 is preferably composed of a rubber sheet airbag 25 that expands and contracts by air intake and exhaust. An air supply mechanism (not shown) for supplying air is connected to the airbag 25.

  The retainer ring 9 is formed in a ring shape and disposed on the outer periphery of the carrier 8. The retainer ring 9 is attached to a retainer ring holder 27 provided in the polishing head 3, and the elastic sheet 11 is stretched on the inner peripheral portion thereof.

  The elastic sheet 11 is formed in a circular shape, and a plurality of holes 22 are opened. The elastic sheet 11 is stretched on the inner side of the retainer ring 9 by sandwiching the peripheral edge portion between the retainer ring 9 and the retainer ring holder 27.

  An air chamber 29 is formed between the carrier 8 and the elastic sheet 11 below the carrier 8 on which the elastic sheet 11 is stretched. The wafer W on which the conductive film is formed is pressed against the carrier 8 through the air chamber 29. The retainer ring holder 27 is attached to an attachment member 30 formed in a ring shape via a snap ring 31. A retainer ring pressing member 10 a is connected to the mounting member 30. The retainer ring 9 is transmitted with the pressing force from the retainer ring pressing means 10 via the retainer ring pressing member 10a.

  The retainer ring pressing means 10 is disposed on the outer peripheral portion of the lower surface of the head body 7, and applies a pressing force to the retainer ring pressing member 10 a to press the retainer ring 9 coupled thereto against the polishing pad 6. The retainer ring pressing means 10 is preferably constituted by a rubber sheet airbag 16b, like the carrier pressing means 16. An air supply mechanism (not shown) for supplying air is connected to the airbag 16b.

  Then, as shown in FIG. 3 or FIG. 4, one prediction / detection device 33 at the end of polishing is incorporated in each of the upper part of the platen 2 or the carrier 8 of the polishing head 3 in the chemical mechanical polishing apparatus 1. It is. When the prediction / detection device 33 at the polishing end time is incorporated on the platen 2 side, a detection signal such as a waveform change portion for predicting the polishing end time from the prediction / detection device 33 at the polishing end time is sent to the slip ring 32. Output to the outside.

Note that two or more prediction / detection devices 33 at the end of polishing may be incorporated in the upper portion of the platen 2 or the carrier 8 portion of the polishing head 3. By incorporating two or more prediction / detection devices 33 at the end of polishing and collecting film thickness information in time series from the prediction / detection device 33 at the end of polishing on the front side in the rotation direction, Conductive film 28 in
The distribution information of the film thickness change is obtained.

FIG. 5 is a diagram showing a configuration example of the prediction / detection device 33 at the end of polishing, where (a) is a block diagram, (b) is a diagram showing another configuration example of a planar inductor, and (c) is a diagram ( It is sectional drawing of the planar inductor of b). The oscillation circuit 35 constituting the main body of the high-frequency inductor type sensor 34 in the prediction / detection device 33 at the time of completion of polishing has a lumped constant capacitor 37 having a capacitance C _{0 in addition} to a two-dimensional planar inductor 36 having an inductance L. Are connected in series to form an LC circuit. The planar inductor 36 is formed in a meander shape using a conductive material such as Cu on a rectangular substrate 36a made of an insulator.

  In addition to the spiral shape shown in FIG. 5 (a), the planar inductor 36 may be formed in a meander shape on a rectangular substrate 41a as in the planar inductor 41 shown in FIG. 5 (b). Good. Moreover, it is good also as a round spiral which is not shown in figure. The two-dimensional planar inductors 36 and 41 are formed by forming a conductive film such as Cu on the substrates 36a and 41a made of an insulator such as glass, epoxy, paper, phenol, etc., and then manufacturing them by etching or the like. As shown in FIG. 5C, the overall shape can be reduced to a square shape having a side of about 23 mm. Further, a small magnetic field can be efficiently generated by downsizing the planar inductors 36 and 41, and the vicinity of the end point where the conductive film 28 is removed without penetrating the magnetic field deeply into the conductive film 28. It is possible to accurately detect the change behavior of.

  An output signal from the LC circuit is input to an amplifier 38 composed of an operational amplifier or the like, and an output of the amplifier 38 is input to a feedback network 39 composed of a resistor or the like. The output signal of the feedback network 39 is positively fed back to the planar inductor 36, whereby the oscillation circuit 35 is configured including the planar inductor 36.

The oscillation circuit 35 basically has an oscillation frequency band f having an inductance L of the planar inductor 36 and a lumped constant capacitor 37 as shown in the following equation (1), as shown in the configuration example of FIG. It has an oscillation circuit of the Colpitts like determined by the capacitance C _0.

  A frequency counter 40 is connected to the output terminal of the amplifier 38. From the frequency counter 40, a detection signal indicating a waveform change portion for predicting a polishing end point, which will be described later, is digitally output to the outside. By digitally transmitting the detection signal output, the influence of noise and output attenuation are prevented. In addition, manageability of the film thickness data can be obtained.

  A high-frequency inductor type sensor 34 including the planar inductor 36 and the frequency counter 40 constitute a polishing end prediction / detection device 33. By arranging the oscillation circuit 35 in the high-frequency inductor sensor 34 and the frequency counter 40 for monitoring the change of the oscillation (resonance) frequency in close proximity, wiring / connection between the oscillation circuit 35 and the frequency counter 40 is performed. A distributed constant circuit is formed in the portion to prevent the inductance and capacitance from becoming unnecessarily large, and the change in magnetic flux accompanying the progress of polishing of the conductive film 28 provided in the vicinity of the high-frequency inductor sensor 34 is accurately detected. It becomes possible.

In the prediction / detection device 33 at the end of the polishing, other components or circuits excluding the planar inductor 36 are integrated into an IC (integrated circuit) and incorporated in a package 33a. The planar inductor 36 is covered with a thin insulating film and fixed to the surface of the package 33a. When the packaged polishing end prediction / detection device 33 is incorporated in the chemical mechanical polishing device 1, as shown in FIGS. 3 and 4, the planar inductor 36 is a conductive film on the surface of the wafer W. It is incorporated so as to face 28.

  The capacitance of the lumped constant capacitor 37 constituting the oscillation circuit 35 is variable, and the high frequency inductor sensor 34 can select an oscillation frequency within the range of the oscillation frequency band.

In this embodiment, in order to predict the polishing end point to be described later based on the magnetic flux change when the predetermined conductive film 28 being polished has a film thickness corresponding to the skin depth δ of the predetermined conductive film 28. The waveform change part is detected. The skin depth δ in the predetermined conductive film 28 is determined as shown in Expression (2) depending on the material of the predetermined conductive film 28 and the oscillation frequency f of the high-frequency inductor sensor 34.

  ω: 2πf, μ: permeability, σ: conductivity.

  Then, the high-frequency inductor type is used so that the skin depth δ is smaller than the initial film thickness of the predetermined conductive film 28 and larger than the film thickness of the predetermined conductive film 28 in the portion excluding the buried portion at the end of polishing. The oscillation frequency f of the sensor 34 is selected. When the material of the conductive film 28 to be polished and removed is Cu, the oscillation frequency band is selected to be 20 MHz or higher.

In addition, even when the frequency is selected as a high frequency band and the inductor is a planar inductor, the waveform effect due to the skin effect appears depending on the distance between the inductor and the conductive film and the inductor shape. Sometimes it doesn't come out. For example, a frequency of 40 MHz is used, the same planar inductor is used, and one inductor is 1/1000 the size of a full-size inductor and the distance between the inductor and the conductive film is also 1/1000. Even when the same 40 MHz frequency and planar inductor are used, the change waveform of the resonance frequency with respect to the film thickness is different. One has a peak at 0.1 μm or less, but does not have a peak in an inductor of 1/1000 size and distance, and increases monotonically with the film thickness.
In an actual size inductor, most of the magnetic flux is parallel to the surface of the conductive film and the magnetic flux does not penetrate the film. That is, the magnetic flux does not enter the conductor film due to the skin effect. On the other hand, in the inductor having a size and distance of 1/1000, the magnetic flux penetrates the conductive film. The effect of the skin effect is not working at this inductor size. Therefore, as the film thickness increases, the eddy current increases monotonously, and the mutual inductance and (impedance) only increase accordingly. Therefore, even if the same frequency and the same planar inductor are used, the effect of the skin effect may or may not appear depending on the size and distance. Here, a state in which the influence of the skin effect appears in the film thickness reduction process by polishing is created, and the end point is predicted and detected in that state.
Note that the film thickness range affected by the skin effect in this case does not coincide with the skin depth δ represented by the above formula (2) determined simply by the frequency and the material (conductivity and permeability) of the conductive film. .

This is because the skin effect changes depending on the size and distance of the inductor, and as a result, it is also influenced by the direction (directivity) of the magnetic field. However, as shown in the above equation, the relationship that the distance that the magnetic field can penetrate becomes smaller as the frequency, conductivity, and permeability increase satisfies the relationship of the above equation and corresponds. Therefore, the film thickness range in which the skin effect appears is a value corresponding to the skin depth δ in the above formula.
Therefore, the characteristic waveform based on the skin effect here is not only the frequency, conductivity, permeability, but also the directivity of the magnetic field, so that the magnetic flux hardly penetrates into the conductive film under certain conditions. Another condition is a characteristic waveform change obtained by utilizing a significant change in the state in which the magnetic flux enters the conductive film.

  Here, “the film thickness corresponding to the skin depth” and “the magnetic flux change caused by the skin effect” will be described with reference to FIGS. FIG. 7 is a diagram showing the result of electromagnetic simulation on the direction ((a) to (d) the arrow in the lower part of each figure) in which the magnetic field generated from the coil is arranged on the conductor film. FIG. 4A shows the case where the oscillation frequency from the sensor is 1 MHz and the film thickness of the conductor film is 0.2 μm. FIG. 5B shows the case where the oscillation frequency from the sensor is 1 MHz and the film thickness of the conductor film is 1 μm. FIG. 4C shows the case where the oscillation frequency from the sensor is 40 MHz and the film thickness of the conductor film is 0.2 μm, and FIG. 6D shows the case where the oscillation frequency from the sensor is 40 MHz and the film thickness of the conductor film is 1 μm. .

  In the electromagnetic simulation setting, the inductor that forms the magnetic field is a planar inductor having no directivity. The “film thickness corresponding to the skin depth” means “film thickness at which magnetic flux changes due to the skin effect”. When the oscillation frequency of the sensor is 1 MHz, the magnetic flux on the conductor film existing on the lower side of the coil is directed in the vertical direction. At this frequency, even if the film thickness is 1 μm and 0.2 μm, the magnetic flux penetrates through the conductor film (FIGS. 7A and 7B). When the magnetic flux penetrates through such a conductor film, as shown in the conventional example, the eddy current generated inside the conductor film decreases as the film thickness decreases. Therefore, in the case of 1 MHz, since the film has a monotonous behavior at a film thickness of 1 μm or less, the skin effect does not appear, and the “film thickness corresponding to the skin depth” is also considered to be at least 1 μm thick.

  On the other hand, when the oscillation frequency of the sensor is 40 MHz, the direction of magnetic flux on the conductor surface is clearly horizontal, and when the film thickness is 1 μm, it hardly penetrates into the conductor (FIG. 7D). Obviously, the direction of the magnetic flux entering the conductor film is different from the case where the oscillation frequency is 1 MHz and the film thickness is 1 μm (FIG. 7B).

  However, when the oscillation frequency is 40 MHz and the conductor film is thinned to 0.2 μm (FIG. 7C), only a part of the magnetic flux is directed toward the inside of the conductor film. This indicates that even if the conductor film is Cu, a part of the magnetic flux penetrates the conductor film when the conductor film is thin.

  In the case of this alternating magnetic flux of 40 MHz, the penetration state of the magnetic flux in the conductor film changes corresponding to the skin effect. Due to the effect of gradually increasing the penetrating magnetic flux, the frequency rapidly rises to about 700 mm. When the film thickness is 1 μm or more, the magnetic flux hardly penetrates. Therefore, in this case, the “film thickness corresponding to the skin depth” can be about 1 μm when the film thickness at the boundary of whether or not the magnetic flux penetrates. For this reason, when the oscillation frequency is increased to 40 MHz and a planar inductor is used, almost no magnetic flux enters the 1 μm thick Cu conductor film, which is due to the skin effect.

Further, when the Cu conductor film has an oscillation frequency of 40 MHz and the Cu conductivity is 58 × 10 ⁶ S / m, the skin depth δ is 9.34 μm. In the calculation, if the film thickness is 1 μm, the magnetic flux sufficiently enters the conductor film, but since a planar inductor is used and the magnetic flux has no directivity, the film actually has an oscillation frequency of 40 MHz. Even if the thickness is 1 μm, the magnetic field does not enter the conductor film due to the skin effect. As the conductor film becomes thinner, part of the magnetic flux enters the conductor film and a slight eddy current is generated. From this, instead of actively using eddy currents to measure the film thickness, when a thin film thickness near the end point is reached, a slight leakage / penetration magnetic flux is used due to the skin effect to make the conductor The inflection point (maximum point) of the mutual inductance induced in the film can be used to monitor the film thickness state near the end point of the conductor film.

  Next, the polishing action and the prediction / detection method of the polishing end point of the chemical mechanical polishing apparatus incorporating the polishing end point prediction / detection apparatus configured as described above will be described with reference to FIGS. This will be described with reference to e) and FIGS. 10A to 10E as comparative examples of FIG. FIG. 8 is a diagram for explaining an inductance changing action due to a magnetic field generated by electromagnetic coupling in a high-frequency inductor type sensor, and FIG. 9 predicts an example of changes in magnetic flux and eddy current accompanying polishing removal of a conductive film and a polishing end point. It is a set of diagrams for explaining the detection action of the waveform change portion for performing, (a) ~ (d) is a diagram showing a change example of the magnetic flux and eddy current accompanying the polishing removal of the conductive film, (e) is It is a characteristic view which shows the example of a change of the resonant frequency with respect to the film thickness change of an electroconductive film. In FIGS. 9A to 9D, the planar inductor 36 is displayed in a spiral shape for easy viewing of the drawing.

  First, the standby conductive film 28 is placed on a non-polished wafer W at a predetermined position by a moving mechanism (not shown) in the chemical mechanical polishing apparatus 1. Then, the vacuum line 24 of the polishing head 3 is activated, and the air chamber 29 on the lower surface of the elastic sheet 11 is evacuated through the vacuum port 19a and the hole 22 (vacuum hole), whereby the conductive film 28 is unpolished. The wafer W is sucked and held, and the moving mechanism carries the polishing head 3 on which the conductive film 28 sucked and held the unpolished wafer W onto the platen 2, and the conductive film 28 is polished by the conductive film 28. It is placed on the platen 2 so as to contact the pad 6.

  When the polishing operation of the conductive film 28 on the upper portion of the wafer W is completed, the vacuum line 24 sucks and holds the wafer W by the polishing head 3 again by the operation of the vacuum line 24 and transports it to a cleaning device (not shown). Sometimes used.

  Next, the operation of the vacuum line 24 is released, and air is supplied to the airbag 25 from a pump (not shown) to inflate the airbag 25. At the same time, air is supplied to the air chamber 29 from the air outlet 19 provided in the carrier 8. Thereby, the internal pressure of the air chamber 29 becomes high.

  Due to the expansion of the air bag 25, the conductive film 28 and the retainer ring 9 on the wafer W are pressed against the polishing pad 6 with a predetermined pressure. In this state, the platen 2 is rotated in the direction of arrow A in FIG. 1 and the polishing head 3 is rotated in the direction of arrow B in FIG. 1, and slurry is supplied from a nozzle (not shown) onto the rotating polishing pad 6. The predetermined conductive film 28 is polished.

  Then, as will be described below, a waveform change portion for predicting the end point of polishing by monitoring the change in film thickness of the predetermined conductive film 28 accompanying the polishing by the magnetic flux formed by the planar inductor 36 in the high-frequency inductor sensor 34. Is detected.

  The planar inductor 36 is driven at a high frequency oscillated from the oscillation circuit 35, and a magnetic flux φ that changes with time corresponding to the period of the high frequency is generated from the planar inductor 36. The magnetic flux φ induced in the predetermined conductive film 28 at the initial stage of polishing passes through the region of the film thickness corresponding to the skin depth δ substantially in parallel along the film surface, and the skin in the predetermined conductive film 28 Intrusion of the magnetic flux φ into the region exceeding the film thickness corresponding to the depth δ is avoided (FIG. 9A). Further, the resonance frequency oscillated from the high-frequency inductor sensor 34 is also kept constant regardless of the change in film thickness of the predetermined conductive film 28 (region a in FIG. 9E).

When polishing progresses and the predetermined conductive film 28 has a film thickness equivalent to or near the film thickness corresponding to the skin depth δ, a part of the magnetic flux φ leaks through the predetermined conductive film 28. the magnetic flux φ _L begins to occur. The magnetic flux φ that does not penetrate the predetermined conductive film 28 passes through the film surface almost in parallel. Then, an eddy current Ie is generated in proportion to the number of leakage magnetic fluxes φ _L penetrating into the predetermined conductive film 28 (FIG. 9B).

Moreover the polishing progresses, generated wide region eddy current Ie is increasing leakage flux phi _L is along the film surface of the conductive film 28 (FIG. 9 (c)). As shown in FIG. 8, the eddy current Ie generated in the wide area further creates a magnetic field M, and the magnetic field M acts to cancel the magnetic flux φ _L generated from the original planar inductor 36. As a result, due to the magnetic field M formed by the conductive film 28, the mutual inductance Lm increases, and the apparent inductance L of the original planar inductor 36 decreases. As a result, the oscillation frequency f oscillated from the high-frequency inductor type sensor 34 increases as shown in Expression (3).

  Therefore, due to the mutual inductance, the inductance of the sensor circuit system is equivalently reduced and the resonance frequency oscillated from the high frequency inductor sensor 34 is increased (regions b and c in FIG. 9E).

Furthermore the leakage flux phi _L with the progress of polishing is increased by saturated. However, the eddy current Ie rapidly decreases as the film thickness volume of the predetermined conductive film 28 decreases (FIG. 9D). Due to the rapid decrease of the eddy current Ie, the mutual inductance also decreases rapidly. This rapid decrease in mutual inductance leads to a decrease in inductance Lm in equation (3). As a result, the inductance of the sensor circuit system increases equivalently, and the resonance frequency oscillated from the high-frequency inductor sensor 34 is increased. Decreases rapidly (region d in FIG. 9E).

  Thus, after the predetermined conductive film 28 becomes a film thickness equivalent to or near the film thickness corresponding to the skin depth δ due to the progress of polishing, the eddy current Ie is generated and then rapidly decreased. The inductance of the sensor circuit system once decreases and then increases. Due to this behavior, a peak (inflection point) occurs in the waveform of the resonance frequency oscillated from the high frequency inductor sensor 34. Based on this peak, a waveform change portion P for predicting the polishing end time before the polishing end time is detected, and the polishing end time is predicted from the change portion P. When the predetermined conductive film 28 is Cu, the remaining film amount at the time when the changed portion P is detected is about 1000 mm, and final polishing or the like is performed on the remaining film amount to finish the polishing.

  As the final polishing, for example, the polishing is finished after polishing the film thickness corresponding to the skin depth, which is the amount of remaining film in the waveform changing portion P, for a predetermined polishing time from the waveform changing portion P. And Alternatively, the polishing rate between the time from the beginning of polishing until the waveform change portion P is detected and the amount of polishing until the waveform change portion P is reached, and the remaining film amount in the waveform change portion P is calculated. The required polishing time after detecting the waveform change portion P is calculated by dividing the film thickness corresponding to a certain skin depth by the polishing rate. Then, after the change portion P is detected, the polishing is finished by polishing for the calculated polishing time.

Next, a comparative example of FIGS. 10A to 10E will be described. In the comparative example, a frequency is applied such that the film thickness corresponding to the skin depth δ is larger than the initial film thickness of the conductive film 28. When such a frequency is applied, all the magnetic flux φ induced in the conductive film 28 continuously leaks through the conductive film 28 during monitoring of the film thickness change from the initial polishing to the final polishing. φ _L is generated. Accordingly, during the monitoring of the thickness change, an eddy current Ie is proportional to the leakage magnetic flux phi _L number is generated (in Fig. 10 (a) ~ (d) ). For this reason, a large mutual inductance is generated between the conductive film 28 and the planar inductor due to the eddy current Ie, and the oscillation frequency f oscillated from the sensor by the decrease Lm of the inductance due to the mutual inductance is equal to the initial polishing time. Thus, the above equation (3) is obtained.

  Then, the eddy current Ie sharply decreases as the film thickness decreases due to the progress of polishing (from (b) to (d) in FIG. 10), and the mutual inductance decreases accordingly. The inductance decrease Lm also decreases. As a result, the inductance of the sensor circuit system increases equivalently, and the resonance frequency oscillated from the sensor decreases monotonously ((e) in FIG. 10).

  In this way, in the comparative example, the resonance frequency has a monotonically decreasing curve, so it is possible to estimate the amount of film thickness reduction from the initial stage of polishing, but it is not possible to strictly determine the state at the end of polishing or before the end of polishing. Can not. For example, when the stray capacitance C changes due to delicate settings, the overall resonance frequency in FIG. 10E shifts up and down over the entire waveform. For this reason, even if the polishing end point is set when a certain set frequency is reached, the threshold value cannot be set if the resonance frequency shifts as a whole. Even if the state of the removal amount from the initial film thickness is monitored in real time by eddy current change, if the initial film thickness varies, the film thickness at the polishing end point also varies. Since there is no waveform feature, the threshold cannot be set in this case as well.

  11 (a) to 11 (d) evaluated the peak that becomes the waveform change portion P for two types of wafers Wa and Wb in which the conductive film to be polished is different in terms of material and conductivity. Results are shown. FIG. 4A shows a wafer Wa with a Cu film, FIG. 5B shows a change characteristic of the resonance frequency with respect to the film thickness of the Cu film, FIG. 5C shows a wafer Wb with a tungsten (W) film, and FIG. It is a figure which shows the change characteristic of the resonant frequency with respect to the film thickness of each. The sensor outputs on each vertical axis in FIGS. 11B and 11D correspond to the resonance frequency.

  In both the Cu film and the tungsten (W) film, the resonance frequency once increases with the progress of polishing, and then sharply decreases to generate a peak (inflection point). The waveform change portions P are detected based on these peaks (inflection points). This behavior is clearly more pronounced in the Cu film having a high conductivity shown in FIG. 11B than in the case of the tungsten (W) film shown in FIG.

  12A and 12B are diagrams showing the relationship between the film thickness and the resonance frequency when the conductive film to be polished is a Cu film, and FIG. The figure which shows the relationship with a resonant frequency, (b) is a figure which shows the relationship between the film thickness in a resting state, and the resonant frequency. The count values on each vertical axis in FIGS. 12A and 12B correspond to the resonance frequency.

  In FIG. 12A, the initial film thickness of the Cu film is approximately 1.5 μm (15000 mm). As the polishing progresses, the resonance frequency of the Cu film gradually increases from about 1 μm (10000 mm), and takes the maximum value near 700 mm, and the waveform change portion P is detected. The resonance frequency drops rapidly after taking the maximum value. Thus, the remaining film thickness of the Cu film when the waveform change portion P is detected is detected with high accuracy.

  In FIG. 12 (b), the resonance frequency measured for each film thickness of the Cu film in a stationary state shows a maximum value at a film thickness of 710mm. Therefore, the film thickness of the Cu film that maximizes the resonance frequency in a stationary state and the film thickness of the Cu film that maximizes the resonance frequency during the above-described polishing are substantially the same.

  Next, a method for predicting the polishing end point using the peak of the resonance frequency during the magnetic flux change process as the film thickness reference point will be further described.

  First, FIG. 13 is a diagram showing the relationship between the film thickness and the resonance frequency in correspondence with the film thickness. The most standard predictive detection method at the end of polishing is that the portion corresponding to the peak of the resonance frequency waveform in FIG. 13 is defined as a film thickness reference value, and polishing is performed based on the film thickness reference value. In this case, the end point is calculated. The polishing end point is determined as the end point when the Cu film is removed, that is, when the Cu film reaches 0A.

  As shown in FIG. 13, the film thickness reference value corresponding to the peak of the waveform corresponds to 710A. In this figure, the resonance frequency waveform is monitored, and the point in time when the peak point is reached is detected. As a method for detecting the peak, the waveform always rises as the film thickness decreases, and then follows a behavior that rapidly decreases. Therefore, it is only necessary to determine the peak point when the resonance frequency is lower than before. As another method, the peak position may be a portion where the differential coefficient is 0 or less or negative while obtaining the differential coefficient as needed.

  In the case of FIG. 13, a blanket film having a Cu film of 16000A is prepared here as an initial film, a polishing event at the time when the Cu film is removed is predicted, and an end point is detected. In FIG. 13, the remaining film thickness reference point of 780A is reached at 89s after the start of polishing. That is, the amount removed from the initial stage is about 16000A−780A = 15220A. Assuming that 89290 passes and 15290A is removed, the time required to remove the remaining 780A is about 4.43 s. That is, if the polishing is stopped about 4.5 seconds after the film thickness reference point is detected, the Cu film thickness is almost 0 A, and the polishing can be accurately stopped at the polishing end point. Here, of course, it is assumed that removal is performed at a constant polishing rate during polishing.

  As another method, it is possible to detect even before the resonance frequency peak position. For example, in the present invention, the waveform of the resonance frequency undergoes a process of rapidly increasing before reaching the peak point of the resonance frequency. This increase rate may be set in advance, and when the increase rate is reached, the polishing end point may be predicted. Alternatively, the point in time when the rate of increase is maximized may be monitored in advance, and the point in time when the rate of increase will be maximized may be defined as the film thickness reference point and set from that point. In this way, when the end point is detected by the rate of increase, it is effective to show a waveform obtained by differentiating the waveform of the resonance frequency as needed, as shown in FIG. When predicting when a predetermined rate of increase is reached, set a threshold for the differentiated graph, and back-calculate the polishing time required up to the end point based on the polishing time that reached the threshold. can do.

  Here, as an example, a method of defining the point of time when the maximum increase rate is defined as a film thickness reference point and predicting the polishing end point from that point is shown. FIG. 14 shows that the maximum rate of increase is obtained at 81 s. At this time, the remaining film thickness corresponds to 2149A. Accordingly, if 13851A is polished after 81 s, the time required for polishing the remaining 2149A is 12.56 s. Therefore, when the polishing is finished after 12.5 seconds, the Cu film thickness becomes approximately 0 A, and the polishing can be stopped with high accuracy when the polishing is completed.

  In this manner, it is possible to predict the end point of polishing at various portions. For example, when a graph differentiated twice as shown in FIG. 15 is shown, the inflection point of the resonance frequency, that is, In the graph differentiated twice in FIG. 15, a point that becomes 0 may be defined as a film thickness reference point to predict the polishing end point. Further, the polishing time until the end of the polishing may be estimated using the point where the degree of change in the increase rate of the resonance frequency is a predetermined value as a reference and the point as the film thickness reference point.

As shown above, in the case of obtaining a waveform peculiar to the skin effect that takes a behavior in which the resonance frequency rises once and then sharply decreases as the film thickness decreases by polishing, there are various points before the polishing is completed. A characteristic change can be monitored, and based on the change, it is possible to accurately estimate the polishing time until the polishing end point. This is substantially the prediction of the polishing end point, but in the case of predicting immediately before the polishing end, it has the same meaning as detecting the polishing end point.

Note that this embodiment, in addition to the mutual inductance of the resonant frequency, the eddy current Ie, it is possible to detect the waveform change portion P based on at least one of a change of the change in leakage flux phi _L. The change in the mutual inductance can be obtained from the change in the oscillation frequency of the high-frequency inductor type sensor 34 using the equation (3). Since the eddy current Ie is proportional to the mutual inductance, the change in the eddy current Ie. it is to seek the can be determined using the change in mutual inductance, also the change of the leakage magnetic flux phi _L is the leakage flux phi _L since it is proportional to the eddy current Ie with the change of the eddy current Ie it can.

As described above, in the method and apparatus for predicting / detecting the end point of polishing according to the present embodiment, the predetermined conductive film 28 is equal to or near the skin depth by the progress of polishing, and the film thickness before the end point of polishing. the waveform change portion P by leakage magnetic flux phi _L consisting of the base detection occurs, the Joule heat loss due to the eddy current Ie generated by the leakage magnetic flux phi _L can be suppressed to a minimum from becoming in the.

  It is remarkable during each change of eddy current Ie, mutual inductance, or resonance frequency after the predetermined conductive film 28 becomes a film thickness equivalent to or near the film thickness corresponding to the skin depth δ due to the progress of polishing. Therefore, the waveform change portion P before the polishing end point can be accurately detected based on the remarkable peak. Therefore, the polishing end point can be accurately predicted and detected from the waveform change portion P.

  Since the resonance frequency transmission method from the high frequency inductor sensor 34 is digital output using the frequency counter 40, the influence of noise and attenuation of the resonance frequency output are prevented, and the waveform change portion P is reliably detected. be able to.

  By making the lumped constant capacitor 37 constituting the high-frequency inductor sensor 34 variable in capacitance, the film thickness corresponding to the skin depth δ becomes an appropriate value for the conductive film 28 of different film types. The oscillation frequency can be easily selected.

  The planar inductor 36, which is a main component of the high-frequency inductor sensor 34, hardly generates noise and consumes power, and can be reduced in cost because it is relatively inexpensive.

  Hereinafter, a real-time film thickness monitoring method and apparatus according to Embodiment 2 of the present invention will be described. In this embodiment, the prediction / detection device 33 at the end of polishing shown in FIGS. 5A, 5B, and 5C functions as a real-time film thickness monitoring device. The real-time film thickness monitoring device 33 is incorporated in the platen 2 or the polishing head 3 as shown in FIGS.

A real-time film thickness monitoring method by the real-time film thickness monitoring device 33 will be described. The waveform changing portion P before the polishing end point shown in FIG. 9E is detected by the same method as in the first embodiment. The waveform change portion P output from the frequency counter 40 is input to a CPU or the like (not shown), and based on the change portion P, the remaining film amount to be removed that is substantially equal to the film thickness corresponding to the skin depth δ, and already Each polishing data such as a polishing rate is calculated on the spot from the amount of film thickness removed by polishing and the required time, and it is evaluated in real time whether a predetermined conductive film 28 is properly removed.

As described above, in the real-time film thickness monitoring method and apparatus according to the present embodiment, after detecting the waveform change portion P for predicting the polishing end time before the polishing end time, the waveform change portion P is used as a basis. Each polishing data such as the amount of remaining film to be removed and the polishing rate can be accurately calculated on the spot, and it is possible to accurately evaluate whether or not the predetermined conductive film 28 is properly removed. Also it is possible to suppress the same time be minimized Joule heat loss due to the eddy current Ie generated by leakage magnetic flux phi _L.

  The present invention can be variously modified without departing from the spirit of the present invention, and the present invention naturally extends to the modified ones.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a chemical mechanical polishing apparatus incorporating a prediction / detection device at the end of polishing according to an embodiment of the present invention. FIG. 2 is an enlarged longitudinal sectional view of a polishing head in the chemical mechanical polishing apparatus of FIG. 1. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic side view showing a partially broken view for explaining a state in which a polishing / ending time prediction / detection device according to an embodiment of the present invention is incorporated in a platen. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partially cutaway schematic side view for explaining a state in which a polishing / end prediction / detection device according to an embodiment of the present invention is incorporated in a polishing head. It is a figure which shows the structural example of the prediction and the detection apparatus at the time of completion | finish of grinding | polishing which concerns on the Example of this invention, (a) is a block diagram, (b) is a figure which shows the other structural example of a planar inductor, (c) ) Is a cross-sectional view of the planar inductor of FIG. FIG. 6 is a diagram illustrating a basic configuration example of an oscillation circuit in the prediction / detection device at the time of completion of polishing in FIG. 5, where (a) is a configuration diagram, and (b) is an equivalent circuit of FIG. In the Example of this invention, it is a figure which shows the result of carrying out the electromagnetic simulation about what direction the magnetic field generated from the coil was arranged on the conductor film, (a) is a conductor with the oscillation frequency from a sensor of 1 MHz. When the film thickness is 0.2 μm, (b) is when the oscillation frequency from the sensor is 1 MHz and the conductor film thickness is 1 μm, and (c) is when the oscillation frequency from the sensor is 40 MHz and the film thickness of the conductor film. (D) is when the oscillation frequency from the sensor is 40 MHz and the film thickness of the conductor film is 1 μm. The block diagram for demonstrating the change effect of the inductance by the magnetic field which generate | occur | produces by the electromagnetic coupling in the high frequency inductor type sensor which concerns on the Example of this invention. FIG. 2 is a set of diagrams for explaining a detection example of a waveform change portion for predicting a change example of a magnetic flux or the like accompanying polishing removal of a conductive film by the chemical mechanical polishing apparatus of FIG. 1 and a polishing end point; (D) is a figure which shows the example of a change of the magnetic flux etc. accompanying grinding | polishing deletion of an electroconductive film, (e) is a characteristic figure which shows the example of a change of the resonant frequency with respect to the film thickness change of an electroconductive film. FIG. 10 is a group diagram as a comparative example of FIG. 9, in which (a) to (d) are diagrams showing examples of changes in magnetic flux and eddy current accompanying polishing removal of the conductive film, and (e) is a change in film thickness of the conductive film. The characteristic view which shows the example of a change of the resonant frequency with respect to. In an embodiment of the present invention, a peak serving as a waveform change portion for predicting a polishing end time is evaluated for a Cu film and a tungsten (W) film in which the conductive film to be polished is different in terms of material and conductivity. (A) is a diagram showing a wafer with a Cu film, (b) is a diagram showing an example of a change characteristic of the resonance frequency with respect to the film thickness of the Cu film, and (c) is with a tungsten (W) film. The figure which shows a wafer, (d) is a figure which shows the example of a change characteristic of the resonant frequency with respect to the film thickness of a tungsten (W) film | membrane. In the Example of this invention, it is a figure which shows the relationship between a film thickness and a resonance frequency about the case where the electroconductive film | membrane of grinding | polishing object is Cu film | membrane, (a) is the relationship between the film thickness and resonance frequency accompanying progress of grinding | polishing. The figure which shows an example, (b) is a figure which shows the example of a relationship between the film thickness in a stationary state, and the resonance frequency. The figure which shows the relationship between a film thickness and the resonant frequency in the Example of this invention. The figure which shows a response | compatibility with the film thickness change and the primary differential value of the resonant frequency in the Example of this invention. The figure which shows a response | compatibility with the film thickness change and the secondary differential value of a resonant frequency in the Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Chemical mechanical polishing apparatus 2 Platen 3 Polishing head 4 Rotating shaft 5 Motor 6 Polishing pad 7 Head main body 8 Carrier 9 Retainer ring 10 Retainer ring pressing means 11 Elastic sheet 12 Rotating shaft 13 Dry plate 14 Pin 15 Actuation transformer 16 Carrier pressing means 17 Air Float Line 19 Air Blowout Port 20 Air Filter 21 Air Supply Pump 22 Hole 23 Vacuum Pump 24 Vacuum Line 25 Airbag 27 Retainer Ring Holder 28 Conductive Film 29 Air Chamber 30 Mounting Member 31 Snap Ring 32 Slip Ring 33 Polishing End Point Prediction / detection device (real-time film thickness monitoring device)
34 High Frequency Inductor Type Sensor 35 Oscillation Circuit 36 Planar Inductor 36a Insulating Substrate 37 Lumped Capacitor 38 Amplifier 39 Feedback Network 40 Frequency Counter 41 Planar Inductor 41a Insulating Substrate P Film Thickness Reference Point W Wafer

Claims (26)

A method for predicting and detecting a polishing end time by polishing a conductive film and predicting and detecting a polishing end time when a predetermined conductive film is properly removed,
An inductor in a high-frequency inductor type sensor is brought close to the predetermined conductive film, and a change in magnetic flux induced in the predetermined conductive film by a magnetic flux formed by the inductor is monitored. Using the magnetic flux change that appears prominently by the skin effect determined by the material of the conductive film as a factor, the magnetic flux change portion for detecting the end point of polishing is detected during the magnetic flux change process, and polishing is performed from the magnetic flux change portion. A method for predicting and detecting a polishing end point, wherein the end point is predicted.   The method for detecting a magnetic flux change portion due to the skin effect is characterized by detecting characteristic changes peculiar to the skin effect such as peak apex, inflection point, rate of change increase, amount of increase change, and start point of increase. The method for predicting and detecting the polishing end point according to claim 1.   The method of detecting a magnetic flux change portion due to the skin effect is characterized by detecting a characteristic change peculiar to the skin effect, such as a waveform peak point, an inflection point, and a predetermined rise rate point. Method.   3. The method of predicting and detecting at the end of polishing according to claim 1, wherein the high-frequency inductor type sensor close to the conductive film is a two-dimensional planar inductor.   The high-frequency inductor type sensor close to the conductive film has a configuration in which a conductive film is attached to the surface of a substrate formed of an insulator. Prediction / detection method.   The change in magnetic flux induced based on the skin effect of the predetermined conductive film is measured by measuring eddy currents in the predetermined conductive film, and by generating mutual eddy currents in the predetermined conductive film. Measurement of inductance, measurement of inductance change of the sensor circuit system in the high frequency inductor type sensor due to mutual inductance of the predetermined conductive film, or change of resonance frequency at which the high frequency inductor type sensor oscillates the inductance change of the sensor circuit system 5. The method for predicting and detecting the polishing end point according to claim 1, 2, 3 or 4, characterized in that the measurement is at least one of measurements in step (1).   6. An oscillator for oscillating the high frequency inductor type sensor and a frequency counter for monitoring a change in the oscillation (resonance) frequency thereof are arranged close to the high frequency inductor type sensor. Prediction and detection method at the end of polishing.   Magnetic flux change, eddy current change, mutual inductance change and resonance frequency change induced based on the skin effect of the predetermined conductive film are caused by the increase of the penetrating magnetic flux as the film thickness decreases. The prediction / detection of the polishing end point according to claim 5 or 6, including two changes: an increase change and a change due to a substantial decrease in the eddy current formation region as the film thickness subsequently decreases. Method. A method for predicting and detecting a polishing end time by polishing a conductive film and predicting and detecting a polishing end time when a predetermined conductive film is properly removed,
The inductor in the high-frequency inductor sensor is brought close to the predetermined conductive film, and the magnetic flux penetrating the conductive film to be polished increases as the film thickness decreases due to the polishing process. Select the inductor shape and frequency band that increases the inductance, monitor the magnetic flux change induced in the predetermined conductive film by the magnetic flux formed by the inductor, and the film thickness during polishing is noticeable due to the skin effect And detecting a magnetic flux change portion for predicting a polishing end time during the magnetic flux change process, and predicting a polishing end time from the magnetic flux change portion. Prediction / detection method.   9. The method according to claim 8, wherein the selected frequency band is 20 MHz or higher when the material of the predetermined conductive film is Cu.   A method for predicting / detecting a polishing end point by polishing a conductive film and predicting and detecting a polishing end point when the predetermined conductive film is properly removed, wherein a high frequency is applied to the predetermined conductive film. A frequency at which at least a part of the magnetic flux formed by the inductor in the initial stage of polishing does not penetrate the predetermined conductive film due to a skin effect of the predetermined conductive film in the initial stage of polishing. Is oscillated from the high-frequency inductor type sensor, and at least once the magnetic flux penetrating the conductive film increases as the polishing progresses. The change in leakage magnetic flux penetrating through the predetermined conductive film is monitored, and the change in leakage magnetic flux in which the film thickness during polishing is noticeable due to the skin effect is utilized. A method for predicting and detecting a polishing end time, wherein a leakage flux changing portion for predicting a polishing end time in the leakage flux changing process is detected, and a polishing end time is predicted from the leakage flux changing portion. . A method for predicting and detecting a polishing end time by polishing a conductive film and predicting and detecting a polishing end time when a predetermined conductive film is properly removed,
An inductor in a high-frequency inductor type sensor is brought close to the predetermined conductive film, and at least a part of the magnetic flux formed by the inductor in the initial stage of polishing is caused by the skin effect of the predetermined conductive film. An inductor shape that generates a non-directional magnetic field that does not penetrate the conductive film and a frequency that does not penetrate the conductive film due to the skin effect are oscillated from the high-frequency inductor type sensor, and the predetermined conductivity is increased according to the progress of polishing. The magnetic flux passing through the conductive film has at least one process of increasing the magnetic flux, and the magnetic flux generated by the inductor causes a change in the magnetic flux leaking through the predetermined conductive film during polishing. Monitor the eddy current as a change, and finish polishing during the eddy current change process where the film thickness during polishing is noticeable due to the skin effect. Prediction and detection method of polishing end point, characterized in that to detect the eddy current change portion for predicting a point, to predict the polishing end point from eddy current change portion.   Regarding the method for predicting the polishing end point from the waveform change portion due to the skin effect, polishing is ended after polishing for a preset polishing time from the waveform change portion. The method for predicting and detecting the polishing end point according to 4, 5, 6, 7, 8, 9, 10 or 11.   13. The polishing end point prediction / polishing method according to claim 12, wherein the waveform change portion is a peak apex, an inflection point, a change increase rate, an increase change amount, and a change specific to the skin effect of the increase start point. Detection method.   Regarding the predictive detection method from the waveform change portion due to the skin effect to the end of polishing, the time at which the waveform change portion has been reached from the initial stage of polishing and the amount of polishing up to the waveform change portion, calculate the corresponding polishing rate, By dividing the film thickness calculated from the characteristic waveform change by the polishing rate, the remaining polishing time is calculated from the waveform change portion to the end of polishing, and after polishing for the time calculated from the waveform change point 14. The method for predicting and detecting the end point of polishing according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, or 13, characterized in that the end point of polishing is used. A method for predicting and detecting a polishing end time by polishing a conductive film and predicting and detecting a polishing end time when a predetermined conductive film is properly removed,
An inductor in a high-frequency inductor type sensor is brought close to the predetermined conductive film, and at least a part of the magnetic flux formed by the inductor in the initial stage of polishing is caused by the skin effect of the predetermined conductive film. An inductor shape that generates a non-directional magnetic field that does not penetrate the conductive film and a frequency that does not penetrate the conductive film due to the skin effect are oscillated from the high-frequency inductor type sensor, and the at least part of the inductor shape as the polishing progresses. Eddy current generated by a change in leakage magnetic flux penetrating through the predetermined conductive film during polishing, out of the magnetic flux formed by the inductor, at least once in the process of increasing the magnetic flux penetrating the conductive film. Is monitored as a change in mutual inductance generated in the inductor by the eddy current, and the film thickness during polishing is Based on the change in the mutual inductance when the skin depth is equal to or near the skin depth due to the skin effect, a change portion of the mutual inductance for predicting the polishing end time is detected, and the polishing end time is predicted from the change portion. A method for predicting and detecting a polishing end point, characterized by: A method for predicting and detecting a polishing end time by polishing a conductive film and predicting and detecting a polishing end time when a predetermined conductive film is properly removed,
An inductor in a high-frequency inductor type sensor is brought close to the predetermined conductive film, and at least a part of the magnetic flux formed by the inductor in the initial stage of polishing is caused by the skin effect of the predetermined conductive film. An inductor shape that generates a non-directional magnetic field that does not penetrate the conductive film and a frequency that does not penetrate the conductive film due to the skin effect are oscillated from the high-frequency inductor type sensor, and the at least part of the inductor shape as the polishing progresses. The high frequency based on a change in leakage magnetic flux penetrating through the predetermined conductive film during polishing, out of the magnetic flux formed by the inductor, at least once. Changes in the inductance of the sensor circuit system in the inductor type sensor are determined by fixing the inductance and the sensor circuit system. Change in resonance frequency to monitor the end of polishing based on the change in resonance frequency when the film thickness during polishing reaches the film thickness corresponding to the skin effect. A method for predicting and detecting a polishing end point, wherein a part is detected and a polishing end point is predicted from the changed part. A method for predicting and detecting a polishing end time by polishing a conductive film and predicting and detecting a polishing end time when a predetermined conductive film is properly removed,
An inductor in a high-frequency inductor type sensor is brought close to the predetermined conductive film, and at least a part of the magnetic flux formed by the inductor in the initial stage of polishing is caused by the skin effect of the predetermined conductive film. An inductor shape that generates a non-directional magnetic field that does not penetrate the conductive film and a frequency that does not penetrate the conductive film due to the skin effect are oscillated from the high-frequency inductor type sensor, and the at least part of the inductor shape as the polishing progresses. Eddy current generated by a change in leakage magnetic flux penetrating through the predetermined conductive film during polishing, out of the magnetic flux formed by the inductor, at least once in the process of increasing the magnetic flux penetrating the conductive film. Change of the mutual inductance generated in the inductor due to the change of the eddy current, or Monitoring the change in at least one of the changes in the resonance frequency oscillated from the high-frequency inductor type sensor due to the change in the inductance of the sensor circuit system in the high-frequency inductor type sensor based on the structure. Based on the change in at least one of the above changes when the film thickness corresponds to the effect, a change portion of the resonance frequency for predicting the polishing end time is detected, and the polishing end time is determined from the change portion. A method for predicting and detecting a polishing end point, characterized by predicting. Corresponding to the skin depth during each change of the eddy current, the mutual inductance or the resonance frequency when the film thickness of the predetermined conductive film during polishing becomes a film thickness corresponding to the skin depth. The maximal point (peak) occurs due to the two phenomena of eddy current increase due to the increase in leakage flux caused by the film thickness and the decrease in eddy current formation region due to the decrease in film thickness volume due to polishing,
18. The method for predicting and detecting a polishing end point according to claim 17, wherein the changed portion is detected based on the maximum point (peak). A real-time film thickness monitoring method for polishing a conductive film and monitoring a film thickness change during polishing for evaluating whether a predetermined conductive film is properly removed,
An inductor in a high-frequency inductor type sensor is brought close to the predetermined conductive film, and at least a part of the magnetic flux formed by the inductor in the initial stage of polishing is caused by the skin effect of the predetermined conductive film. A frequency that does not penetrate the conductive film is oscillated from the high-frequency inductor type sensor, and has a process in which the magnetic flux penetrating the at least a part of the conductive film is increased at least once during polishing, as the polishing progresses. The leakage of the magnetic flux formed in the above-described case is monitored by monitoring the change of the leakage magnetic flux penetrating through the predetermined conductive film during polishing, and the film thickness during polishing becomes a film thickness corresponding to the skin effect. The change part of the leakage magnetic flux for predicting the polishing end point is detected from the change of the magnetic flux, and the polishing rate and the remaining part to be removed on the spot are detected based on the change part. Real-time thickness monitoring method and calculates the Atsuryou. A real-time film thickness monitoring method for polishing a conductive film and monitoring a film thickness change during polishing for evaluating whether a predetermined conductive film is properly removed,
An inductor in a high-frequency inductor type sensor is brought close to the predetermined conductive film, and at least a part of the magnetic flux formed by the inductor in the initial stage of polishing is caused by the skin effect of the predetermined conductive film. A frequency that does not penetrate the conductive film is oscillated from the high-frequency inductor type sensor, and has a process in which the magnetic flux penetrating the at least a part of the conductive film is increased at least once during polishing, as the polishing progresses. Changes in leakage flux that penetrates the predetermined conductive film during polishing are monitored as changes in eddy current created by the leakage flux, and the film thickness during polishing corresponds to the skin effect. The change part of the leakage magnetic flux for predicting the end point of polishing is detected from the change in the eddy current when the film thickness reaches the desired film thickness. Real-time thickness monitoring method and calculates the remaining film thickness amount to be polishing rate and removal. A real-time film thickness monitoring method for polishing a conductive film and monitoring a film thickness change during polishing for evaluating whether a predetermined conductive film is properly removed,
An inductor in a high-frequency inductor type sensor is brought close to the predetermined conductive film, and at least a part of the magnetic flux formed by the inductor in the initial stage of polishing is caused by the skin effect of the predetermined conductive film. A frequency that does not penetrate the conductive film is oscillated from the high-frequency inductor type sensor, and has a process in which the magnetic flux penetrating the at least a part of the conductive film is increased at least once during polishing, as the polishing progresses. The change in eddy current caused by the change in leakage magnetic flux penetrating through the predetermined conductive film during polishing is monitored as the change in mutual inductance generated in the inductor by the eddy current during polishing. When the polishing finishes from the change of the mutual inductance when the thickness of the film reaches the thickness corresponding to the skin effect. Real-time film thickness monitor method characterized by detecting the mutual inductance changing portion for predicting, it calculates the remaining film thickness amount to be polishing rate and removed on the fly based on the modified moiety. A real-time film thickness monitoring method for polishing a conductive film and monitoring a film thickness change during polishing for evaluating whether a predetermined conductive film is properly removed,
An inductor in a high-frequency inductor type sensor is brought close to the predetermined conductive film, and at least a part of the magnetic flux formed by the inductor in the initial stage of polishing is caused by the skin effect of the predetermined conductive film. A frequency that does not penetrate the conductive film is oscillated from the high-frequency inductor type sensor, and has a process in which the magnetic flux penetrating the at least a part of the conductive film is increased at least once during polishing, as the polishing progresses. Change of the inductance of the sensor circuit system in the high-frequency inductor type sensor based on the change of the leakage magnetic flux penetrating the predetermined conductive film during the polishing process. Monitors the change in resonance frequency determined by the capacitance, and the film thickness during polishing corresponds to the skin effect. The change part of the resonance frequency for predicting the polishing end point is detected from the change of the resonance frequency when the film thickness reaches a predetermined film thickness, and the polishing rate and the remaining film thickness to be removed on the spot based on the change part A real-time film thickness monitoring method characterized by calculating an amount.   During the change of the eddy current, the mutual inductance, or the resonance frequency when the film thickness of the predetermined conductive film being polished is equal to or close to the skin depth, the leakage is caused by the skin effect. A peak is generated by the action of two phenomena, an increase in eddy current due to an increase in magnetic flux and a decrease in eddy current due to a decrease in film volume due to polishing, and a change for predicting the end point of polishing based on the peak. 23. The real-time film thickness monitoring method according to claim 20, 21 or 22, wherein a portion is detected. A high-frequency inductor type sensor having an oscillation circuit that constitutes a sensor circuit system composed of a planar inductor and a capacitor, and polishing the conductive film, and when the predetermined conductive film is properly removed A prediction / detection device for predicting and detecting the end of polishing,
A prediction / detection method at the end of polishing according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17 or 18 is executed. An apparatus for predicting / detecting the end of polishing. A high-frequency inductor type sensor having an oscillation circuit that constitutes a sensor circuit system composed of a planar inductor and a capacitor, for polishing whether or not a predetermined conductive film is properly removed by polishing the conductive film A real-time film thickness monitoring device that monitors film thickness changes during polishing,
24. A real-time film thickness monitoring apparatus that executes the real-time film thickness monitoring method according to claim 19, 20, 21, 22, or 23.

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