KR20090024073A - Method and device for forecasting/detecting polishing end point and method and device for monitoring real-time film thickness - Google Patents

Abstract

A method and apparatus for forecasting/detecting the polishing end point are provided to accurately evaluate whether the predetermined conductive film was appropriately removed, or not by calculating the residue amount and the polish rate. The chemical mechanical polishing apparatus(1) is comprised of the platen(2) and the polishing head(3). The axis of rotation(4) is connected to the center of the lower face of platen. The polishing pad(6) is adhered in the upper side of platen. Each forecasting/detecting device(33) of the polishing end point is mounted on the upper part of the platen. The slip ring(32) outputs the detection signal including the waveform change part to outside. The inductor(36) is comprised of the meander type.

Description

Method and device for forecasting / detecting polishing end point and method and device for monitoring real-time film thickness

The present invention relates to a method for predicting and detecting a polishing completion point, a device thereof, a real-time film thickness monitoring method and a device thereof, and particularly, to minimize Joule heat loss due to eddy currents in chemical mechanical polishing (CMP). After suppressing by, the polishing end point can be predicted and detected with high accuracy, and the prediction and detection method and the device and the real time point at the end of polishing can be evaluated in real time to accurately determine whether a predetermined conductive film is properly removed. The present invention relates to a film thickness monitoring method and an apparatus thereof.

An oxide film is formed on the surface of the semiconductor wafer, for example, by lithography and etching to form a groove pattern corresponding to the wiring pattern, and a conductive film made of Cu or the like for filling the groove pattern is formed thereon. A process of forming a wiring pattern by removing unnecessary portions other than the buried portion such as the groove pattern or the through-hole portion of the conductive film by chemical mechanical polishing is known. In the formation of this wiring pattern, it is very important to stop the process by reliably detecting the polishing end point when the conductive film of the unnecessary portion is removed to an appropriate thickness. If the polishing of the conductive film is excessive, the resistance of the wiring increases, and if the polishing is excessive, it leads to insulation failure of the wiring.

As a related art in this regard, the method of monitoring the change of film thickness on the spot as follows is known, for example. This prior art is a method for monitoring the thickness change of the conductive film on the spot in a method of removing the conductive film by chemical mechanical polishing from the base body (semiconductor wafer), and is shaped to bring directivity to the electromagnetic field. A sensor comprising a series or parallel resonant circuit of an inductor and a capacitor composed of a coil wound around a ferrite pot core for the proximity of the conductive film, and having a frequency of 20 Hz to 40.1 MHz from the excitation signal source. A sweep output consisting of frequency is applied to the sensor via impedance means for operating point setting. As a result, when the sensor is excited, an oscillation current flows through the coil to generate an alternating electromagnetic field. This alternating electromagnetic field then induces an eddy current into the conductive film. If eddy currents are induced into the conductive film, two effects are produced. First, firstly, the conductive film acts as a loss resistor, and the effect is a resistive load on the sensor circuit, which lowers the amplitude of the resonance signal and lowers the resonance frequency. Secondly, the reduction in the thickness of the conductive film results in an effect such that the metal rod is pulled out of the coil of the inductor, which causes a change in inductance and a frequency shift. In this way, by monitoring the change in the frequency shift associated with the sensor resonance peak resulting from the change in the thickness of the conductive film, the thickness change of the conductive film is continuously detected (see, for example, Document 1).

In addition, as another conventional technique, the following eddy current sensor is known, for example. In this conventional technique, a conductive film or an eddy current sensor disposed in the vicinity of a substrate on which a conductive film is formed, and an AC signal having a constant frequency of about 8 to 32 MHz are supplied to the sensor coil to form the conductive film. An ac signal source for forming an eddy current, a detection circuit for measuring a reactance component and a resistance component containing the conductive film, wherein the sensor coil includes an oscillation coil connected to the signal source, and the conductive film of the coil. The detection coil arrange | positioned at the side and the balance coil arrange | positioned on the opposite side to the said electroconductive film side of the said oscillation coil are provided, and the said detection coil and a balance coil are connected so that it may mutually reverse phase. The synthesized impedance is output from the resistance component and the reactance component detected by the detection circuit, and the change in the film thickness of the conductive film is detected as a nearly linear relationship in a wide range from the change in the impedance (for example, , Reference 2).

In addition, as another conventional technique, the following eddy current sensor is known, for example. This conventional technique is similar to the conventional technique described above. In the document 3, the magnetic flux formed by the sensor coil passes through the conductive film on the substrate disposed on the entire surface of the sensor coil, and alternately changes this conductivity. An eddy current is generated during film formation, and an eddy current loss occurs because the eddy current flows in the conductive film, and the equivalent circuit reduces the reactance component of the impedance of the sensor coil. In addition, in Document 3, by observing a change in the oscillation frequency of the oscillation circuit, if the conductive film gradually becomes thin as the polishing progresses, the oscillation frequency is lowered accordingly, and the conductive film is completely removed by polishing. Becomes the self oscillation frequency of the tank circuit, after which the oscillation frequency becomes approximately constant. Therefore, by detecting this point, it is said that the end point by chemical mechanical polishing of a conductive film can be detected. In addition, in Document 3, as shown in FIG. 2, when 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 division circuit or subtracted by the subtractor, thereby displaying a signal corresponding to the magnitude of the frequency of the detection width on the monitor. Thereby, the transition of the frequency locus as shown in FIG. 2 mentioned above is obtained (for example, refer document 3).

[Document 1] Japanese Patent No. 2878178 (2-7 pages, Figs. 1-15).

[Document 2] Japanese Patent No. 3587822 (third page, Figs. 1 to 11).

[Document 3] Japanese Unexamined Patent Publication No. 2003-21501

In the prior art described in Document 1, a series or parallel resonant circuit of an inductor and a capacitor composed of a coil wound around a ferrite port type core for bringing directivity to an electromagnetic field in a sensor is provided. Then, at the beginning of polishing, a sweeping output composed of a frequency of 20 Hz to 40.1 MHz is applied to the sensor, and by means of an alternating electromagnetic field generated by the coil, a leakage magnetic flux that penetrates the conductive film is generated, and the film thickness of the conductive film is The corresponding large eddy current is induced from the beginning of polishing. In order to induce a large eddy current corresponding to the film thickness of the conductive film, it is necessary to form a large alternating electromagnetic field, i.e., a large magnetic flux that penetrates the conductive film, and monitoring the thickness change of the conductive film is conducted from the initial polishing to the final polishing. It is performed using the eddy current induced in the film. For this reason, it is necessary to penetrate a magnetic flux toward the thickness direction of a conductive film, while monitoring a change of film thickness. In the drawings of the publication relating to Document 1, this is evident from the fact that magnetic flux lines penetrating the conductive film are described in all the conductive film portions.

It is common that an innocent Cu film (conductive film) is on the top layer on the surface of the wafer in the initial polishing stage. Very large leakage magnetic flux is required to cause eddy currents in all of these innocent Cu films. However, the leakage magnetic flux causes eddy currents, but they are consumed in a row in the form of eddy current loss anyway. This Joule heat loss is relatively small in heat generation because the volume resistance is small with respect to the inexhaustible Cu film of the outermost layer. Eddy currents are induced, resulting in locally large Joule losses. This sometimes leads to a problem that some wirings are melted and disconnected. It becomes what is called an induction heating state, and the phenomenon in which heat | fever becomes full especially inside arises. In particular, in the Cu wiring or the like, when Cu is heated, Cu may diffuse into the barrier film such as Ta, or in some cases, Cu may break through the barrier film and diffuse.

In addition, in the case where a plurality of layers of wiring are provided on the surface of the wafer, not only the surface of the Cu film but also the internal wiring portion that has already been processed is locally warmed and diffused around, or the p-type in the semiconductor substrate, n In some cases, the dopant forming the die is further diffused to change the characteristics of the element in the substrate. In addition, even when heat does not generate | occur | produce, when excess eddy current flows through a fine wiring, electromigration may occur and it may be disconnected.

In addition, for example, when a predetermined | prescribed residual film amount near the completion | finish of grinding | polishing becomes a process and it changes with polishing conditions, it is difficult to confirm whether it is a predetermined residual film amount. It can be estimated from the change from the initial film thickness, but if the initial film thickness is not constant, there is a variation in the estimation of the predetermined residual film amount. Regarding the determination near the polishing end point, if the gap between the sensor and the conductive film is changed slightly by the vibration of polishing, the stray capacitance of the entire sensor circuit system is changed to shift the entire resonance frequency. Therefore, even if the threshold value is set when the set resonance frequency is reached, and the polishing end point is set as a whole, if the resonance frequency is shifted as a whole, the polishing end point by the setting of the threshold value is determined. Judgment becomes difficult. Thus, in the conventional method, even if the threshold value is set at any value at the resonance frequency that is monotonous and continuously increases or decreases, the gap between the sensor and the conductive film is slightly changed, or When some dielectric material is interposed therebetween, the waveform itself often moves up and down in parallel as a whole, and as a result, the preset threshold value often has no meaning.

Also in the prior art described in Document 2 using the eddy current sensor, the monitoring of the change in the film thickness of the conductive film is regarded as the change in the eddy current from the initial polishing to the final polishing, which is almost the same as the prior art described in Document 1.

In addition, in the above-described conventional technique of monitoring the film thickness of the conductive film by using the eddy current from the initial polishing period to the final polishing period, it is necessary to make a magnetic flux strong enough to penetrate into the film to cause the eddy current in the film. The shape of is in three dimensions to direct the magnetic flux. Therefore, there are generally the following problems in attaching the sensor to a polishing apparatus or the like. The current flowing through the coil increases, which increases the power consumption, and the power supply unit also becomes large. Magnetic flux leaks to the surroundings and noise is likely to occur. The process of winding the conducting wire into a coil shape is required, which is expensive.

In the prior art made of the eddy current sensor described in Document 3, first, with respect to the hardware of the sensor unit used in this prior art, first, the sensor coil is configured on the premise that the sensor coil penetrates the conductive film. Therefore, in 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 in which the eddy current is formed is monotonically reduced, and therefore, the behavior in which the oscillation frequency is monotonously reduced is described. This part is supposed to be detected. In other words, in the software algorithm used in the prior art, the change in the oscillation frequency is a change that becomes substantially constant from the decrease as the change in the oscillation frequency. For example, a change in which the oscillation frequency has an inflection point If not, it is not an algorithm that can be detected. In addition, as shown in FIG. 2, the magnetic flux penetrates a conductive film from the beginning of grinding | polishing, and a eddy current is always generated. Here, the eddy current sensor generally uses the eddy current sensor as a method of actively generating an eddy current and calculating it again from the eddy current change to the film thickness change.

Therefore, the fine wiring formed in the film does not have a strong magnetic flux, and as a result, suppresses generation of eddy current caused by electromagnetic induction, minimizes Joule heat loss due to eddy current, and simultaneously gaps between the sensor and the conductive film. The amount of induced eddy current shifts as a whole according to the change of the dielectric material and the interposition state of the dielectric material such as slurry, and the threshold value is greatly changed so that it is difficult to detect and does not penetrate the device wafer. Even a minute magnetic field of the magnetic field can be detected with sufficient precision, and the polishing end point can be accurately predicted and detected, and the remaining film amount and polishing rate to be removed can be precisely calculated on the spot, and a predetermined challenge can be obtained. What needs to be addressed to accurately assess whether the film is properly removed? Technical problems arise, and an object of this invention is to solve this problem.

The present invention has been proposed in order to achieve the above object, and the invention described in claim 1 is a prediction of the polishing end point for polishing the conductive film and predicting and detecting the polishing end point when the predetermined conductive film is properly removed. As a detection method, an inductor in a high frequency inductor type sensor is brought close to the predetermined conductive film, and the magnetic flux change caused by the predetermined conductive film is monitored by the magnetic flux formed by the inductor, and the film thickness during polishing is In the magnetic flux change process, the magnetic flux change portion for predicting the end point of polishing is detected by using the magnetic flux change that is remarkably represented by the skin effect determined by the material of the predetermined conductive film as one factor. Predicting the end point of polishing from the The ball.

According to this configuration, the inductor is driven at a high frequency, and a magnetic flux that changes corresponding to the period 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 advances and the predetermined conductive film reaches a film thickness equal to or close to the skin depth, leakage magnetic flux penetrating through the predetermined conductive film starts to occur. According to the change of the magnetic flux, the amount of eddy current caused by electromagnetic induction in the predetermined conductive film changes. As the eddy current decreases as the film thickness decreases, the leakage magnetic flux that penetrates the membrane increases, so that the eddy current gradually induced increases. Due to the eddy current generated in this wide area, a large mutual inductance is generated in this predetermined conductive film. This mutual inductance acts to reduce the magnetic inductance of the sensor circuit system in the high frequency inductor type sensor. In this way, even if the thickness of the conductive film is initially reduced, a constant eddy current is formed when the magnetic flux introduced to the conductive film thickness does not penetrate the wafer. Thereafter, when the film thickness is further reduced to become the film thickness corresponding to the skin depth or less, a magnetic flux in which some magnetic flux penetrates the conductive film on the wafer and leaks to the back surface of the wafer is generated. At this time, the eddy current caused in the film increases with the increase of the leakage magnetic flux. Next, the eddy current formed on the surface of the wafer up to a certain film thickness increases, but after that, as the conductive film is further removed, the eddy current decreases because the conductive film itself that generates the eddy current is reduced. As a result, despite being a monotonous film thickness reduction process, the eddy current increases with once penetration flux increases, and then as the film thickness decreases further, it rapidly decreases as the volume itself causing the eddy current decreases, The maximum point appears in the mutual inductance corresponding to the eddy current. Due to the rapid decrease of the eddy current, the mutual inductance also rapidly decreases and the inductance of the sensor circuit system changes. In this way, after the predetermined conductive film becomes a film thickness equal to or close to the skin depth in accordance with the progress of polishing, an eddy current is generated, and the inductance of the sensor circuit system decreases once due to the rapid decrease thereafter. Then increase to. Due to this behavior, the waveform of the resonant frequency oscillated from the high frequency inductor sensor is markedly changed by the skin effect. In this waveform change process, the waveform change portion for predicting the polishing termination point is detected, and the polishing termination point is predicted from the waveform change portion.

Since this peak is represented by the film thickness corresponding to the skin depth, there is no problem that the setting of the threshold value changes as the amount of induced eddy current as described above shifts as a whole, and the position corresponding to the remaining film thickness is constantly. Peaks appear. In particular, when the conductive film is, for example, Cu, a peak appears in the vicinity of 710 kPa of the remaining film of Cu. Further, in the case of the W film, a peak appears in the portion 2500 kPa of the slightly thicker W film. Although this film thickness differs from actual skin depth, it is a numerical value corresponding to skin depth. The skin depth δ is an index that conveniently indicates the depth at which the intensity of the electromagnetic wave becomes 1 / e. The peak position is determined by the conductivity, permeability, frequency to be applied, etc. of the material. It is caused by the epidermal effect. The present invention is a technique achieved by utilizing the unusual phenomenon exhibited by the skin effect of this material. In particular, since the wiring material has a high electrical conductivity in the CMP of the wiring material, the peak position appears to be a sharp peak (maximum point) relatively near the end point (710 kPa). For this reason, reliable end point detection and end point prediction are possible without shaking with respect to various disturbances.

In addition, the inductor-type sensor intentionally actively causes eddy currents in the film, and does not monitor the film thickness. In a conventional known sensor, a sensor coil is formed so as to give a directivity to impart a magnetic field that penetrates the conductive film. In the inductor sensor of the present invention, a planar inductor is used. This is an inductor whose purpose is not to impart directivity to the magnetic field, but to divert the magnetic field appropriately so as not to penetrate deeply into the conductive film. This is because when the magnetic field penetrates deeply or when a strong magnetic field is applied to penetrate the magnetic field deeply, the wiring itself is disconnected due to eddy currents, local overheating, electromigration, or the like. . Therefore, a planar inductor is formed that does not infiltrate the magnetic field as much as possible into the conductive film and, in other words, forms an appropriate magnetic flux distribution such that an eddy current that does not cause damage to the device is generated. In addition, when the conductive film becomes thin immediately before the conductive film is removed, a portion of the magnetic flux that penetrates the conductive film appears even if a suitable magnetic field is emitted. The rapid change which appears when it becomes the state of the thin conductive film near this end point is monitored. Therefore, the algorithm for detecting the frequency, the inductor, and the signal thereof is configured to maximize the inflection point near the end point.

In the invention described in claim 2, the method for detecting the magnetic flux change portion due to the skin effect includes polishing for detecting characteristic changes peculiar to the skin effect such as peaks of the peak, inflection points, the rate of change of the change, the amount of change of the change, and the starting point of the rise. Provides a method for predicting and detecting the end point.

According to this structure, the magnetic flux change part by the skin effect is performed by detecting a change peculiar to the skin effect such as the peak of the peak of the magnetic flux change, the inflection point, the rate of change of the change, the amount of change of change, the starting point of the rise, and the like.

In the invention according to claim 3, the method for detecting the magnetic flux change portion due to the skin effect is a prediction and detection method at the end of polishing to detect characteristic changes peculiar to the skin effect such as waveform peak points, inflection points, and predetermined ascending point points. To provide.

According to this structure, the magnetic flux change part by the said skin effect is performed by detecting the change peculiar to skin effect, such as a waveform peak point, an inflection point, and a predetermined ascent rate point.

The invention according to claim 4 provides a method for predicting and detecting the end point of polishing, wherein the high frequency inductor type sensor in proximity to the conductive film is a two-dimensional planar inductor.

According to this configuration, in the conventional three-dimensionally formed inductor, the directivity for the magnetic flux to penetrate in the vertical direction with respect to the conductive film is improved, the magnetic flux enters the inside of the device wafer, and the wiring inside the device is caused by electromigration. There was a case of disconnection. On the other hand, according to the method using this two-dimensional planar inductor, since the magnetic flux to the conductive film is appropriately diverged and has no directivity, the magnetic flux does not actively invade the conductive film. In addition, when the frequency to be applied is set to a frequency greater than 30 MHz, the magnetic flux cannot penetrate further into the conductive film due to the skin effect, so that disconnection or excessive heat due to the generation of eddy currents inside the device wafer is excessive. It is possible to prevent the electromigration caused by the current. In addition, when the thickness of the conductive film on the surface is reliably removed, a part of the magnetic flux penetrates the conductive film to form an eddy current. Therefore, when the thickness is near the end point, the waveform corresponds to a very significant mutual inductance. By generating a change of, the end point of polishing can be detected.

Invention of Claim 5 provides the high frequency inductor type sensor which adjoins the said conductive film provides the prediction and detection method of the completion | finish point of grinding | polishing which consists of attaching a conductive film to the surface of the board | substrate formed with an insulator.

According to this configuration, a sensor can be easily and inexpensively produced by depositing or applying a conductive material such as Cu on an insulator substrate such as glass, epoxy or paper or phenol such as a printed board. In addition, even when compared with the method of using a winding, by applying the conductive film and then etching it to produce it, the line width can be made very fine, and the sensor itself can be made extremely small. By miniaturizing the sensor, a smaller magnetic field can be efficiently generated, and the magnetic field does not penetrate deeply into the conductive material, so that the change behavior near the end point where the film is removed can be detected with high accuracy. In addition, the miniaturization of the sensor enables the placement of a large number of sensors in correspondence with the position in the wafer surface, so that the uniformity of polishing in the wafer surface can be detected with high accuracy.

According to the sixth aspect of the present invention, a monitor of a change in magnetic flux induced on the basis of the skin effect of the predetermined conductive film includes the measurement of the eddy current in the predetermined conductive film and the mutual inductance generated when the predetermined conductive film generates the eddy current. Measurement of the inductance change of the sensor circuit system in the high frequency inductor sensor by the mutual inductance of the predetermined conductive film, or the resonance frequency at which the high frequency inductor sensor oscillates the inductance change of the sensor circuit system. Provided are a prediction and detection method at the end of polishing, which is at least one of the measurements in the change.

According to this configuration, the monitor of the magnetic flux change caused on the basis of the skin effect of the predetermined conductive film, specifically, the eddy current, mutual inductance, inductance of the sensor circuit system, or the high frequency inductor sensor according to the magnetic flux change, respectively. By measuring the change in at least one of the oscillating resonant frequencies, the waveform change portion immediately before the polishing end point at which the magnetic flux passing through the predetermined conductive film increases with the progress of polishing is clearly detected.

The invention according to claim 7 includes the prediction of the polishing end point in which an oscillator for oscillating the high frequency inductor sensor and a frequency counter for monitoring a change in the oscillation (resonance) frequency are arranged in proximity to the high frequency inductor sensor. A detection method is provided.

According to this configuration, a distributed constant circuit is formed in the wiring and connection portions as in the prior art, thereby preventing the inductance and capacitance of the circuit from becoming unnecessarily large. For example, the inductor does not dominantly detect a change due to capacitance. It is possible to accurately detect the change in the magnetic flux caused in the vicinity of the type sensor. Preferably, the oscillator and frequency counter are in the same package as the inductor type sensor. In general, a distributed constant circuit is formed in several + MHz bands, and electrostatic coupling occurs between a path and a sample in the middle rather than a change in magnetic flux, and the function as an electrostatic coupling sensor becomes dominant. However, according to this structure, even if it is several + MHz band, since the frequency monitor is arrange | positioned in the vicinity, the area | region to electrostatically couple is limited. For this reason, even in the case of several + MHz bands, rather than a distributed constant circuit, relatively capacitance and inductance function as a constant lumped circuit, and the magnetic material acting as a reaction by the inductor's magnetic flux on the conductive material acts as a reaction to the inductor. The change in inductance can be detected with high accuracy.

According to the invention of claim 8, the change in the magnetic flux, the eddy current, the change in mutual inductance, and the resonant frequency caused based on the skin effect of the predetermined conductive film are changed as the through magnetic flux increases as the film thickness decreases. And a method of predicting and detecting the end point of polishing including two kinds of changes in which the eddy current forming region is substantially reduced with the subsequent decrease in the film thickness.

According to this configuration, when the predetermined conductive film becomes less than the film thickness corresponding to the skin depth with the progress of polishing, the eddy current and mutual inductance are increased together with the increase of the penetrating magnetic flux. The inductance of the system is reduced and the resonance frequency is increased. Thereafter, as the film thickness decreases as the polishing proceeds further, the eddy current forming region is substantially reduced, the eddy current and mutual inductance are each rapidly decreased, and the inductance of the sensor circuit system is rapidly increased so that the resonance frequency is increased. Decreases rapidly. Due to these behaviors, after the predetermined conductive film becomes a film thickness corresponding to the skin depth, a marked change portion appears in the waveforms of the eddy current, mutual inductance, and resonance frequency. Using the change in the waveform, a portion of the waveform change for predicting the end point of polishing during the waveform change process is detected.

The invention according to claim 9 is a prediction and detection method at the end of polishing for polishing a conductive film and predicting and detecting the end time of polishing when the predetermined conductive film is properly removed. Selecting an inductor shape and a frequency band in which the inductor in the sensor is brought close and the mutual inductance caused by the conductive film increases by increasing the magnetic flux through the conductive film to be polished as the film thickness decreases due to the polishing process. By monitoring the magnetic flux change induced in the predetermined conductive film by the magnetic flux formed by the inductor, and using the magnetic flux change in which the film thickness during polishing is remarkable by the skin effect, the polishing end point in this magnetic flux change process is determined. Detect the change in magnetic flux to predict and finish polishing from this change in magnetic flux Provided are a prediction and detection method at the end of polishing for predicting a viewpoint.

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 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 film thickness of the predetermined conductive film at the time of polishing, and the penetrating magnetic flux increases as the film thickness decreases. By forming the inductor shape, the magnetic flux induced in the predetermined conductive film at the beginning of polishing passes through the area of the skin depth almost in parallel along the film surface, and as the polishing progresses, the predetermined conductive film corresponds to the skin depth. When the thickness is less than or equal, a penetrating magnetic flux penetrating through the conductive film to be polished is generated, and the eddy current and mutual inductance are increased as the penetrating magnetic flux is increased. Thereafter, the eddy current forming region is substantially reduced, and the eddy current and mutual inductance are rapidly reduced as the film thickness decreases as further polishing proceeds. After the predetermined conductive film becomes the film thickness corresponding to the skin depth from these behaviors, the magnetic flux change portion for predicting the end point of polishing is detected.

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

According to this constitution, the frequency band oscillated from the high frequency inductor sensor is set to 20 MHz or more in the case of Cu, whereby the skin depth is an order equal to the initial film thickness of the predetermined conductive film. It is set to be smaller than the initial film thickness of the conductive film, and to be larger than the film thickness of the predetermined conductive film in polishing termination.

The invention as set forth in claim 11 is a prediction and detection method at the end of polishing for polishing a conductive film and predicting and detecting the end time of polishing when the predetermined conductive film is properly removed. The inductor in the sensor is brought close to each other, and at least a portion of the magnetic flux formed by the inductor in the initial polishing stage has a frequency such that it does not penetrate the predetermined conductive film due to the skin effect of the predetermined conductive film. At least one process of oscillating from the sensor and increasing at least a portion of the magnetic flux penetrating the conductive film as the polishing proceeds, and leaking magnetic flux penetrating the predetermined conductive film during the polishing process among the magnetic fluxes formed by the inductor Of the film thickness during polishing is monitored by the skin effect By using the change of the leakage magnetic flux which appears to be easy, the leakage magnetic flux change part for predicting the grinding | polishing end point in this leakage magnetic flux change process is detected, and the prediction of the grinding | polishing end point which predicts grinding | polishing end point from this leakage magnetic flux change part is carried out A detection method is provided.

According to this configuration, the magnetic flux formed from the inductor does not penetrate most of the predetermined conductive film at the beginning of polishing, but from the high frequency inductor type sensor so that a skin effect occurs in which leakage magnetic flux penetrating the predetermined conductive film starts to occur as the polishing proceeds. The frequency of oscillation is set. After the predetermined conductive film becomes a film thickness corresponding to the skin depth with the progress of polishing, polishing is finished in the process of changing the leakage magnetic flux by using the change of the leakage magnetic flux that is markedly caused by the skin effect. The leakage magnetic flux change portion for predicting the viewpoint is detected, and the polishing finish timing is predicted from this leakage magnetic flux change portion.

According to the twelfth aspect of the present invention, a polishing end point prediction and detection method for polishing a conductive film and predicting and detecting a polishing end point when the predetermined conductive film is properly removed is a high frequency inductor type. The inductor in the sensor is brought close to each other, the magnetic flux change induced in the conductive film by the magnetic flux formed by the inductor is monitored, and the skin thickness during polishing determines the material of the predetermined conductive film as a factor. In the process of changing the magnetic flux, the magnetic flux change is remarkably detected, and the magnetic flux change portion for predicting the polishing end point is detected, and the polishing end point is predicted from the polishing change part. Provides a prediction and detection 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 described in claim 9, and from the inductor, by its shape, at the beginning of polishing, the surface effect of the predetermined conductive film is applied. As a result, a magnetic field having no directivity such as not penetrating the predetermined conductive film is generated. Then, the change in the leakage magnetic flux generated by the progress of the polishing is monitored as the change in the eddy current, and the prediction of the end point of the polishing in the course of the change of the eddy current in which the predetermined conductive film is markedly caused by the skin effect with the progress of the polishing is performed. The eddy current change portion is detected, and the polishing end point is predicted from this eddy current change portion.

According to the invention described in claim 13, in the method for predicting the end point of polishing from the waveform change portion due to the skin effect, the polishing end prediction is performed after polishing for a predetermined polishing time from the waveform change portion. A detection method is provided.

According to this configuration, in the process of changing the waveform that is markedly shown by the skin effect, the skin change portion for predicting the end point of polishing is detected, and the required polishing after the detection of the waveform change portion is performed from the polishing rate that should be performed after the detection. It is possible to set the time in advance. Therefore, after this waveform change part is detected, grinding | polishing is complete | finished by grinding | polishing for the said preset grinding | polishing time.

The invention according to claim 14, wherein the waveform change portion is a change peculiar to the skin effect of the peak, inflection point, change rate of change, rise change amount, and rise start point of the peak, and provides a prediction and detection method at the end of polishing. do.

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

The invention according to claim 15 relates to the prediction detection method from the waveform change portion due to the skin effect to the end point of polishing, from the time of reaching the waveform change portion to the waveform change portion and the amount of polishing from the waveform change portion, By calculating the polishing rate as much as that, and dividing the film thickness of the waveform change portion by the polishing rate, the remaining polishing time required from the waveform change portion to the polishing end point is calculated, and the calculated portion is calculated from the waveform change portion. After polishing for a time, a prediction and detection method at the end of polishing as the end point of polishing is provided.

According to this configuration, the polishing rate therebetween is calculated from the time from the initial polishing to the detection of the waveform change portion and the amount of polishing until the waveform change portion is reached. 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 detection of the waveform change portion, polishing is terminated by polishing for the calculated polishing time.

The invention as set forth in claim 16 is a prediction and detection method at the end of polishing for polishing a conductive film and predicting and detecting the end time of polishing when the predetermined conductive film is properly removed. The inductor in the sensor is brought close to each other, and at least a part of the magnetic flux formed by the inductor at the beginning of polishing generates a magnetic field having no directivity such that it does not penetrate the predetermined conductive film due to the skin effect of the predetermined conductive film. At least once, a process of oscillating from the high frequency inductor-type sensor by the inductor shape and the surface that does not penetrate the conductive film due to the skin effect, and increasing the magnetic flux passing through the at least part of the conductive film as the polishing proceeds. And the predetermined part of the magnetic flux formed by the inductor during polishing. The change in the eddy current caused by the change of the leakage magnetic flux through the conductive film is monitored as the change in mutual inductance generated in the inductor by this eddy current, and the film thickness during polishing becomes equal to or close to the skin depth due to the skin effect. A method of predicting and detecting a polishing end point for detecting a change in mutual inductance for predicting a polishing end point on the basis of the change in mutual inductance in a case and predicting the polishing end point from this change portion 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 invention described in claim 9, and from the inductor, by its shape, at the beginning of polishing, the surface effect of the predetermined conductive film is applied. As a result, a magnetic field having no directivity such as not penetrating the predetermined conductive film is generated. Then, the change in the leakage magnetic flux generated by the progress of polishing is monitored as the change in mutual inductance generated in the inductor, and the mutual interaction after the predetermined conductive film becomes the film thickness corresponding to the skin depth with the progress of polishing. Based on the change in inductance, the change portion of mutual inductance for predicting the end point of polishing is detected, and the end point of polishing is predicted from the change portion of the mutual inductance.

The invention as set forth in claim 17 is a prediction and detection method at the end of polishing for polishing a conductive film and predicting and detecting the end time of polishing when the predetermined conductive film is properly removed. The inductor in the sensor is brought close to each other, and at least a part of the magnetic flux formed by the inductor at the beginning of polishing generates a magnetic field having no directivity such that it does not penetrate the predetermined conductive film due to the skin effect of the predetermined conductive film. At least once, a process of oscillating from the high frequency inductor-type sensor by the inductor shape and the surface that does not penetrate the conductive film due to the skin effect, and increasing the magnetic flux passing through the at least part of the conductive film as the polishing proceeds. And the predetermined part of the magnetic flux formed by the inductor during polishing. The change in inductance of the sensor circuit system in the high frequency inductor type sensor based on the change of the leakage magnetic flux passing through the conductive film is monitored as a change in the resonance frequency determined by the inductance and the intrinsic capacitance of the sensor circuit system, On the basis of the change in the resonance frequency when the film thickness becomes the film thickness corresponding to the skin effect, the change portion of the resonance frequency for predicting the polishing termination point is detected, and the polishing termination point is determined from the change portion of the resonance frequency. A prediction and detection method at the end of polishing to be predicted is provided.

According to this configuration, the frequency oscillated from the high frequency inductor sensor is set in the same manner as in the operation of the invention described in claim 10 above. In addition, due to the shape of the inductor, a magnetic field having no directivity such that it does not penetrate the predetermined conductive film is generated due to the skin effect of the predetermined conductive film at the beginning of polishing. There is a leakage flux through the membrane. Then, the change in the sensor circuit system inductance in the high frequency inductor sensor according to the change of the leakage magnetic flux is monitored as a change in the resonance frequency determined by the inductance and the intrinsic capacitance of the sensor circuit system, and is determined as the polishing progresses. The portion of change in the resonance frequency is detected on the basis of the change in the resonance frequency after the conductive film has become the film thickness corresponding to the skin depth, and the polishing end point is predicted from the portion in which the resonance frequency changes.

The invention as set forth in claim 18 is a prediction and detection method at the end of polishing for polishing a conductive film and predicting and detecting the end time of polishing when the predetermined conductive film is properly removed. The inductor in the sensor is brought close to each other, and at least a part of the magnetic flux formed by the inductor at the beginning of polishing generates a magnetic field having no directivity such that it does not penetrate the predetermined conductive film due to the skin effect of the predetermined conductive film. At least once, a process of oscillating from the high frequency inductor-type sensor by the inductor shape and the surface that does not penetrate the conductive film due to the skin effect, and increasing the magnetic flux passing through the at least part of the conductive film as the polishing proceeds. And the predetermined part of the magnetic flux formed by the inductor during polishing. Sensor circuit in the high frequency inductor type sensor based on the change of the eddy current resulting from the change of the leakage magnetic flux which penetrates the whole film, the change of mutual inductance which arises in the said inductor due to the change of this eddy current, or this change of mutual inductance. 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 system, and among the respective changes when the film thickness during polishing becomes the film thickness corresponding to the skin effect. A method for predicting and detecting a polishing end point for detecting a change portion of a resonance frequency for predicting a polishing end point based on at least one change, and for predicting the polishing end point from the change portion of the resonance frequency is provided.

According to this configuration, the frequency oscillated from the high frequency inductor sensor is set in the same manner as in the operation of the invention described in claim 10 above. In addition, due to the shape of the inductor, a magnetic field having no directivity such that it does not penetrate the predetermined conductive film is generated due to the skin effect of the predetermined conductive film at the beginning of polishing. There is a leakage flux through the membrane. And at least any one of a change in the eddy current caused by the change in the leakage magnetic flux, a change in the mutual inductance according to the change in the eddy current, or a change in the resonance frequency oscillated from the high frequency inductor sensor based on the change in the mutual inductance. Is monitored, and based on at least one of the change in the eddy current, the change in mutual inductance, or the change in resonance frequency after the predetermined conductive film becomes the film thickness corresponding to the skin depth as the polishing progresses. The change portion of the furnace resonant frequency is detected, and the polishing end time is predicted from the change portion of the resonant frequency.

Invention of Claim 19 respond | corresponds to the said skin depth during each change of the said eddy current, the said mutual inductance, or the said resonance frequency, when the film thickness of the said predetermined conductive film during grinding | polishing becomes a film thickness corresponding to skin depth. The peaks (peaks) are generated by two phenomena: the increase in the eddy current caused by the increase in the leakage flux caused by the film thickness and the decrease in the eddy current forming area due to the decrease in the film thickness volume by polishing. Provided are a prediction and detection method at the end of polishing in which the change portion is detected as a basis.

According to this configuration, in addition to the effect of the invention described in claim 17, the angle of eddy current, mutual inductance, or resonant frequency after the predetermined conductive film becomes the film thickness corresponding to the skin depth as the polishing proceeds. There is a maximal peak during the change. Based on this maximum point (peak), the change portion of the waveform predicting the end point of polishing is detected, and the end point of polishing is predicted from this change portion.

The invention according to claim 20 is a real-time film thickness monitoring method for polishing a conductive film and monitoring a film thickness change during polishing to evaluate whether or not a predetermined conductive film is properly removed. The inductor in the inductor-type sensor is brought close to each other, and at least a part of the magnetic fluxes formed by the inductor in the initial stage of polishing is such that the high frequency does not penetrate the predetermined conductive film due to the skin effect of the predetermined conductive film. Oscillates from an inductor-type sensor and has at least one process of increasing the magnetic flux penetrating the at least part of the conductive film as polishing progresses, and penetrates the predetermined conductive film during the polishing process among the magnetic fluxes formed by the inductor To monitor the change in leakage magnetic flux From the change of the leakage magnetic flux when the film thickness corresponding to the skin effect is reached, the change portion of the leakage magnetic flux for predicting the end point of polishing is detected, and the remainder to be removed and polished in place on the basis of this change portion A real-time film thickness monitoring method for calculating film thickness is provided.

According to this configuration, the magnetic flux formed from the inductor does not substantially penetrate the predetermined conductive film at the beginning of polishing, but from the high frequency inductor type sensor so that a skin effect occurs in which leakage magnetic flux penetrating the predetermined conductive film starts to develop as polishing progresses. The frequency of oscillation is set. Then, the change portion for predicting the end point of polishing from the change in the leakage magnetic flux after the predetermined conductive film becomes the film thickness corresponding to the skin depth with the progress of polishing is detected, and based on this change portion From the amount of residual film to be removed, which is almost equal to the skin depth, and the amount of film thickness already polished and removed and the time required, each polishing data such as polishing rate is calculated on the spot, and it is evaluated whether the predetermined conductive film is properly removed. do.

The invention according to claim 21 is a real-time film thickness monitoring method for polishing a conductive film and monitoring a film thickness change during polishing to evaluate whether a predetermined conductive film is properly removed. The inductor in the inductor-type sensor is brought close to each other, and at least a part of the magnetic fluxes formed by the inductor in the initial stage of polishing is such that the high frequency does not penetrate the predetermined conductive film due to the skin effect of the predetermined conductive film. Oscillates from an inductor-type sensor and has at least one process of increasing the magnetic flux penetrating through the at least part of the conductive film in accordance with the progress of polishing, and during the polishing of the magnetic flux formed by the inductor, Of the eddy current that this leakage magnetic flux makes changes in the leakage magnetic flux penetrating It monitors as a change, and detects the change part of the leakage magnetic flux for predicting the completion | finish point of grinding | polishing from the said eddy current change when the film thickness in grinding | polishing becomes the film thickness corresponding to the said skin effect, and based on this change part It provides a real-time film thickness monitoring method that calculates the polishing rate in place and the remaining film thickness to be removed.

According to this configuration, the frequency oscillated from the high frequency inductor sensor is set in the same manner as in the operation of the invention described in claim 17 above. Then, the change in the leakage magnetic flux is monitored as the change in the eddy current, and a change portion is detected from the change in the eddy current after the predetermined conductive film becomes the film thickness corresponding to the skin depth as the polishing proceeds. Based on the portion, each polishing data such as the polishing rate to be removed from the amount of the remaining film which is almost equal to the depth of the skin and the amount of the film thickness already polished and the required time is calculated on the spot, and the predetermined conductive film is appropriately removed. Is evaluated.

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 to evaluate whether a predetermined conductive film is properly removed, wherein a high frequency is applied to the predetermined conductive film. The inductor in the inductor-type sensor is brought close to each other, and at least a part of the magnetic fluxes formed by the inductor in the initial stage of polishing is such that the high frequency does not penetrate the predetermined conductive film due to the skin effect of the predetermined conductive film. Oscillates from an inductor-type sensor and has at least one process of increasing the magnetic flux penetrating the at least part of the conductive film as the polishing proceeds, and penetrates the predetermined conductive film during the polishing of the magnetic flux formed by the inductor This eddy current changes due to the change of leakage magnetic flux The change part of mutual inductance for monitoring as a change of mutual inductance which generate | occur | produces in the inductor, and for predicting a grinding | polishing end time from the said change of mutual inductance when the film thickness during grinding | polishing becomes the film thickness corresponding to the said skin effect. Is used to detect the change in the mutual inductance for predicting the end point of polishing from this change portion, and calculate the polishing rate and the remaining amount of film thickness to be removed on the basis of this change portion. Provide a monitoring method.

According to this configuration, the frequency oscillated from the high frequency inductor sensor is set in the same manner as in the operation of the invention described in claim 17 above. Then, the change in the leakage magnetic flux is monitored as a change in mutual inductance generated in the inductor, and polishing is terminated from the change in mutual inductance after the predetermined conductive film becomes a film thickness corresponding to the skin depth as the polishing progresses. A change portion of mutual inductance for predicting the viewpoint is detected, and each polishing such as the amount of residual film to be removed almost equal to the depth of the skin and the amount of film thickness already polished and removed from the time required based on this change portion The data is calculated on the spot, and it is evaluated whether the predetermined conductive film is properly removed.

The invention according to claim 23 is a real-time film thickness monitor method for polishing a conductive film and monitoring a change in film thickness during polishing to evaluate whether a predetermined conductive film has been properly removed, wherein a high frequency is applied to the predetermined conductive film. The inductor in the inductor-type sensor is brought close to each other, and at least a part of the magnetic fluxes formed by the inductor in the initial stage of polishing is such that the high frequency does not penetrate the predetermined conductive film due to the skin effect of the predetermined conductive film. Oscillates from an inductor-type sensor and has at least one process of increasing the magnetic flux penetrating the at least part of the conductive film as polishing progresses, and penetrates the predetermined conductive film during the polishing process among the magnetic fluxes formed by the inductor The high frequency inductor type based on a change in leakage magnetic flux The change in inductance of the sensor circuit system in the sensor is monitored as a change in the resonance frequency determined by the inductance and the intrinsic capacitance of the sensor circuit system, and the film thickness during polishing becomes a film thickness corresponding to the skin effect. Real time film thickness monitoring method which detects the change part of the resonance frequency for predicting the polishing termination point from the change of the resonance frequency, and calculates the polishing rate and the remaining film thickness to be removed on the basis of this change part. To provide.

According to this configuration, the frequency oscillated from the high frequency inductor sensor is set in the same manner as in the operation of the invention described in claim 17 above. The change in inductance of the sensor circuit system in the high frequency inductor type sensor according to the change of the leakage magnetic flux is monitored as the change in the resonance frequency determined by the inductance and the intrinsic capacitance of the sensor circuit system, and as the polishing progresses, From the change in the resonance frequency after the predetermined conductive film becomes the film thickness corresponding to the skin depth, a portion of the resonance frequency for predicting the end point of polishing is detected. Each polishing data such as the remaining film amount to be removed, the film thickness already polished and the required time, and the polishing rate are calculated on the spot, and it is evaluated whether the predetermined conductive film is properly removed.

The invention according to claim 24 is characterized by the skin effect during each change in the eddy current, the mutual inductance, or the resonance frequency when the film thickness of the predetermined conductive film during polishing is equal to or close to the skin depth. There are two phenomena, namely, an increase in the eddy current due to the increase of the leakage magnetic flux and a decrease in the eddy current due to the decrease in the film thickness volume due to the polishing, and a peak is generated. It provides a real-time film thickness monitoring method to be detected.

According to this configuration, in addition to the effect of the invention described in claim 20, 21 or 22, the eddy current, mutual inductance, or the like after the predetermined conductive film becomes a film thickness corresponding to the skin depth as the polishing proceeds. A peak occurs during each change in the resonance frequency. Based on this peak, a change portion for predicting the end point of polishing is detected.

The invention according to claim 25 has a high-frequency inductor type sensor having an oscillation circuit constituting a sensor circuit system consisting of a planar inductor and a capacitor, polishing the conductive film to terminate polishing when the predetermined conductive film is properly removed. Claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, as a prediction / detection device at the end of polishing for predicting and detecting a viewpoint. Another object of the present invention is to provide a prediction / detection apparatus at the polishing completion point for executing the prediction and detection method at the polishing termination point described in 18.

According to this configuration, the prediction / detection device at the end of polishing having a high frequency inductor type sensor having an oscillation circuit constituting a sensor circuit system consisting of a planar inductor and a capacitor has a skin depth in a predetermined conductive film. The oscillation frequency of the high frequency inductor type sensor is set so as to be smaller than the initial film thickness of the predetermined conductive film and larger than the film thickness of the predetermined conductive film in polishing termination. As a result, the magnetic flux induced in the predetermined conductive film by the magnetic flux formed by the planar inductor at the initial stage of polishing passes through the region of the skin depth almost in parallel along the film surface, and at least partially The magnetic flux penetrates through the predetermined conductive film, and leakage magnetic flux starts to occur. And the sensor based on the change of the leakage magnetic flux during the polishing, the change of the eddy current resulting from the change of the leakage magnetic flux, the change of mutual inductance occurring in the planar inductor due to the change of this eddy current, or the change of the mutual inductance. After at least one of the change in the resonant frequency oscillated from the high frequency inductor type sensor due to the change in inductance of the circuit system is monitored, and as the polishing progresses, the predetermined conductive film becomes the film thickness corresponding to the skin depth. The change part immediately before a grinding | polishing end point is detected based on the change of at least any one of said each change in, and the grinding | polishing end timing is predicted from this change part.

The invention as set forth in claim 26 has a high-frequency inductor type sensor having an oscillation circuit constituting a sensor circuit system consisting of a planar inductor and a capacitor, and the conductive film is polished to evaluate whether the predetermined conductive film is properly removed. As a real-time film thickness monitoring apparatus for monitoring a film thickness change during polishing, a real-time film thickness monitoring apparatus for executing the real-time film thickness monitoring method according to claim 19, 20, 21, 22 or 23 is provided.

According to this structure, the real-time film thickness monitor apparatus which has the high frequency inductor type sensor provided with the oscillation circuit which comprises the sensor circuit system which consists of a planar inductor and a capacitor has the predetermined skin depth in a predetermined | prescribed conductive film. The oscillation frequency of the high frequency inductor type sensor is set so as to be smaller than the initial film thickness of the conductive film and larger than the film thickness of the predetermined conductive film in polishing termination. As a result, the magnetic flux induced in the predetermined conductive film by the magnetic flux formed by the planar inductor at the initial stage of polishing passes through the region of the skin depth almost in parallel along the film surface, and at least partially The magnetic flux penetrates through the predetermined conductive film, and leakage magnetic flux starts to occur. And the sensor based on the change of the leakage magnetic flux during the polishing, the change of the eddy current resulting from the change of the leakage magnetic flux, the change of mutual inductance occurring in the planar inductor due to the change of this eddy current, or the change of the mutual inductance. After at least one of the change in the resonant frequency oscillated from the high frequency inductor type sensor due to the change in inductance of the circuit system is monitored, and as the polishing progresses, the predetermined conductive film becomes the film thickness corresponding to the skin depth. A change portion immediately before the polishing end point is detected from at least one of the above-described changes in each of the changes, and based on this change portion, the residual film amount to be substantially equal to the skin depth, and the amount of film thickness already polished and From the time required, each polishing data such as polishing rate is calculated on the spot, To assess whether the deposition is appropriately removed.

Invention of Claim 1 makes the inductor in a high frequency inductor type sensor close to a predetermined | prescribed electroconductive film, and monitors the change of the magnetic flux induced in the said predetermined | prescribed electroconductive film by the magnetic flux formed from this inductor, and the film thickness during grinding | polishing Since the magnetic flux change part for predicting the polishing end point is detected based on the change of the magnetic flux caused by the skin effect, which is determined by using the material of the predetermined conductive film as one factor, the polishing end point is predicted from this change part. In the initial stage of polishing, the magnetic flux induced in a predetermined conductive film passes almost parallel to the surface of the skin depth along the film surface. As a result, generation of an eddy current is suppressed without exerting a strong magnetic flux to fine wirings or the like formed in the film, and the Joule heat loss due to this eddy current can be minimized. After the predetermined conductive film becomes a film thickness corresponding to the skin depth with the progress of polishing, a leakage magnetic flux that penetrates the predetermined conductive film is generated, and an eddy current is caused in the predetermined conductive film by this leakage magnetic flux. This eddy current is gradually increased by the increase of the leakage magnetic flux with the decrease of the film thickness, and is rapidly reduced because the film thickness is further reduced to reduce the conductive film itself which generates the eddy current. Due to this increase in eddy current and subsequent rapid decrease, the inductance of the sensor circuit system is once reduced and then changed to increase. This behavior generates a peak (inflection point) in the waveform of the resonant frequency oscillated from the high frequency inductor sensor. And this peak (inflection point) does not fluctuate with respect to various disturbances, but appears constantly in a position corresponding to the remaining film thickness. For this reason, there exists an advantage that it can detect on the basis of the said peak (inflection point), and can accurately predict and detect the completion | finish of grinding | polishing point from the said flux change.

According to the invention described in claim 2, the method for detecting the magnetic flux change portion due to the skin effect is characterized by detecting characteristic changes peculiar to the skin effect such as the peak of the peak, the inflection point, the rate of change of the change, the amount of change of change, the start of the rise, and the like. Prediction and detection at the end of polishing are performed very appropriately.

According to the invention described in claim 3, the method for detecting the magnetic flux change portion due to the skin effect is very effective in predicting and detecting the end point of polishing by detecting changes in the skin effect such as waveform peak points, inflection points, and predetermined ascending point points. It is done appropriately.

In the invention according to claim 4, since the high-frequency inductor sensor close to the conductive film is a two-dimensional planar inductor, the magnetic flux formed by the two-dimensional planar inductor does not have a directivity due to divergence with respect to a predetermined conductive film. As the polishing progresses, the predetermined conductive film does not actively penetrate into the predetermined conductive film until the predetermined thickness becomes a film thickness corresponding to the skin depth. In addition, due to the skin effect, the magnetic flux cannot enter the inside of the conductive film, and therefore, there is an advantage that it is possible to effectively prevent the disconnection due to the generation of eddy currents in the device wafer and the electromigration due to excessive current. .

The invention according to claim 5 has a structure in which a high frequency inductor type sensor in proximity to the conductive film is formed by attaching a conductive film to the surface of a substrate formed of an insulator. By depositing or applying the material, the sensor can be manufactured easily and inexpensively. In addition, after the conductive film is formed on the substrate of the insulator, the film is formed by etching or the like, whereby the line width can be made extremely small, and the sensor itself can be made extremely small. Further, the miniaturization of the sensor makes it possible to efficiently generate a small magnetic field, and to accurately detect the change behavior near the end point from which the conductive film is removed, without penetrating the magnetic field deeply into the conductive film. have.

According to the sixth aspect of the present invention, a monitor of a change in magnetic flux induced on the basis of the skin effect of the predetermined conductive film includes the measurement of the eddy current in the predetermined conductive film and the mutual inductance generated when the predetermined conductive film generates the eddy current. Measurement of the inductance change of the sensor circuit system in the high frequency inductor sensor by the mutual inductance of the predetermined conductive film, or the resonance frequency at which the high frequency inductor sensor oscillates the inductance change of the sensor circuit system. In order to monitor at least one of the magnetic flux changes caused by the predetermined conductive film in the invention according to claim 1, the eddy current, mutual inductance, and sensor circuit system according to the magnetic flux change are measured. At least one of the inductance of the sensor or the resonant frequency at which the high frequency inductor sensor oscillates By using one change, there is an advantage that the change portion of the resonance frequency for predicting the polishing end point immediately before the polishing end point can be detected more easily and clearly.

The invention according to claim 7 is a high frequency inductor sensor because an oscillator for oscillating the high frequency inductor sensor and a frequency counter for monitoring a change in the oscillation (resonance) frequency are arranged in proximity to the high frequency inductor sensor. The distribution constant circuit is formed in the wiring and connection portion between the oscillator and the frequency counter that oscillates the oscillation, thereby preventing the inductance and the capacitance from becoming unnecessarily large. Can be detected with high accuracy.

According to the invention of claim 8, the change in the magnetic flux, the eddy current, the change in mutual inductance, and the resonant frequency, which are caused based on the skin effect of the predetermined conductive film, are changed as the penetration flux increases due to the decrease in the film thickness. Since the eddy current forming region with the subsequent decrease in the film thickness is included in two, the change is caused by substantially decreasing. When the predetermined conductive film becomes less than the film thickness corresponding to the skin depth as the polishing proceeds, As the magnetic flux increases, the eddy current, mutual inductance and resonance frequency increase. Thereafter, as the film thickness decreases as the polishing proceeds further, the eddy current forming region substantially decreases, so that the eddy current, mutual inductance and resonance frequency decrease rapidly. Due to these behaviors, after a predetermined conductive film becomes a film thickness corresponding to the skin depth, peaks (inflection points) are generated in the waveforms of eddy currents, mutual inductances, and resonance frequencies, and based on these peaks (inflection points) The advantage is that the change part can be clearly detected.

According to the invention of claim 9, the inductor of the high frequency inductor type sensor is brought close to a predetermined conductive film, and the magnetic flux that penetrates the conductive film to be polished increases as the film thickness decreases due to the polishing process. Select an inductor shape and a frequency band in which the inductance rises, monitor the magnetic flux change induced in the predetermined conductive film by the magnetic flux formed by the inductor, and change the magnetic flux change caused by the skin effect of the film thickness during polishing. Since the magnetic flux change portion for predicting the polishing completion point was detected based on the basis, and the polishing termination point was predicted from this magnetic flux change portion, the magnetic flux induced in the predetermined conductive film in the polishing initial stage prevents the surface area of the skin depth. Pass almost parallel to each other, and a predetermined conductive film After the film thickness corresponding to the depth, the penetrating magnetic flux penetrating the conductive film is generated, and the eddy current and the mutual inductance increase with the increase of the penetrating magnetic flux. Thereafter, the eddy current forming region is substantially reduced with the decrease of the film thickness as further polishing proceeds, so that the eddy current and mutual inductance are rapidly reduced. The magnetic flux change portion is detected from these behaviors, and there is an advantage in that the polishing end point can be accurately predicted and detected from this change portion.

In the invention described in claim 10, since the frequency band selected is 20 MHz or more when the material of the predetermined conductive film is Cu, the skin depth is polished when the material of the predetermined conductive film is Cu. Initially, it is smaller than the initial film thickness of the predetermined conductive film, and as the polishing progresses, it is just in front of the polishing end point, and the conductive film becomes a film thickness corresponding to the skin depth and leaks through the predetermined conductive film. There is an advantage that can cause.

According to the invention of claim 11, the inductor of the high frequency inductor type sensor is brought close to a predetermined conductive film, and at least part of the magnetic fluxes formed by the inductor in the initial polishing stage is determined by the skin effect of the predetermined conductive film. At least once, a process of oscillating a frequency that does not penetrate a predetermined conductive film from the high frequency inductor sensor and increasing at least a portion of the magnetic flux penetrating the conductive film as the polishing proceeds, and polishing among the magnetic fluxes formed by the inductor Monitor the change of the leakage magnetic flux that penetrates the predetermined conductive film during the progression, and detect the change portion of the leakage magnetic flux to predict the end point of polishing based on the change of the leakage magnetic flux according to the skin effect during film polishing. Since the polishing end point was predicted from this change part, After the predetermined conductive film becomes the film thickness corresponding to the skin depth, the leakage magnetic flux penetrating the predetermined conductive film is caused to proceed, so that the film thickness reference point immediately before the polishing end point is changed based on the change of the leakage magnetic flux. Is detected. Therefore, there is an advantage that the polishing completion point can be accurately predicted and detected from the change in the leakage magnetic flux.

According to the invention of claim 12, the inductor of the high frequency inductor type sensor is brought close to a predetermined conductive film, and at least part of the magnetic fluxes formed by the inductor in the initial polishing stage is determined by the skin effect of the predetermined conductive film. An inductor shape that generates a magnetic field without directivity that does not penetrate a predetermined conductive film, and a frequency that does not penetrate the conductive film by the skin effect are oscillated from the high frequency inductor type sensor, and the predetermined At least once in a process of increasing the magnetic flux penetrating the conductive film, and monitoring the change in the leakage magnetic flux that penetrates the predetermined conductive film during the polishing of the magnetic flux formed by the inductor as a change in the eddy current generated by the leakage magnetic flux, The film thickness during polishing is equal to the skin depth according to the skin effect Since the portion of the leakage magnetic flux for predicting the end point of polishing to be polished was detected based on the change in the eddy current in the vicinity, and the end point of polishing was predicted from the changed portion, Therefore, in the initial stage of polishing, due to the skin effect of the predetermined conductive film, a magnetic field having no directivity such that it does not penetrate the predetermined conductive film is generated, so that no strong magnetic flux can be applied to the fine wirings formed in the film and the Generation is suppressed, and the Joule heat loss due to this eddy current can be minimized. After the predetermined conductive film becomes a film thickness corresponding to the skin depth as the polishing proceeds, leakage magnetic flux penetrating the predetermined conductive film is generated, and polishing is performed based on the change in the eddy current caused by the change of the leakage magnetic flux. The change portion of the eddy current just before the end point is detected. Therefore, there is an advantage that the polishing completion point can be accurately predicted and detected from this change portion.

In the invention according to claim 13, since the polishing is completed after polishing a predetermined polishing time from the waveform change portion in the method of predicting the polishing end point from the waveform change portion caused by the skin effect, the waveform change portion Silver film amount is detected at the time when the film thickness becomes the film thickness corresponding to the skin depth. For this reason, the required polishing time after detecting the waveform change portion can be set in advance from the residual film amount and the polishing rate to be performed after the waveform change portion detection. Therefore, there is an advantage that the predetermined conductive film can be properly polished and removed by polishing after the polishing time set in advance from the detected waveform change portion is finished.

According to the invention described in claim 14, the waveform change portion detects the peak portion of the peak, the inflection point, the rising rate of change, the rising change amount, and the changing portion peculiar to the skin effect of the rising start point, so that the end point of polishing can be accurately predicted.

The invention according to claim 15 relates to the prediction detection method from the change portion due to the skin effect to the end point of polishing, from the time of reaching the waveform change portion to the waveform change portion and the amount of polishing from the waveform change portion. By calculating the polishing rate of, dividing the film thickness of the waveform change portion by the polishing rate, the remaining polishing time required from the waveform change portion to the polishing end point is calculated, and the calculated time from the waveform change point. Since polishing was made to be the end point of polishing, by detecting this waveform change portion, the polishing rate during the time can be calculated from the required time and polishing amount until the detection. When polishing after the waveform change portion is performed with the polishing rate after the waveform change portion detection being the same as the polishing rate before the waveform change portion detection, the film corresponding to the skin depth which is the residual film amount in this waveform change portion. By dividing the thickness by the polishing rate, there is an advantage that the desired conductive film can be properly polished and removed by polishing by the required polishing time after detecting the waveform change portion.

According to the invention of claim 16, the inductor of the high frequency inductor type sensor is brought close to a predetermined conductive film, and at least part of the magnetic fluxes formed by the inductor in the initial polishing stage is determined by the skin effect of the predetermined conductive film. An inductor shape that generates a magnetic field without directivity that does not penetrate a predetermined 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 at least a portion of the inductor as the polishing progresses. Has at least once a process of increasing the magnetic flux penetrating through the conductive film, and the eddy current is caused by the eddy current to change the eddy current caused by the change of the leakage magnetic flux penetrating the predetermined conductive film during the polishing of the magnetic flux formed by the inductor. Monitoring and polishing as changes in mutual inductance occurring in the The change part of mutual inductance for predicting the completion | finish of grinding | polishing end point based on the said change of mutual inductance when the film thickness in it becomes equal to or close to skin depth by the said skin effect is finished, and polishing completion | finishes from this change part Since the viewpoint was to be predicted, the inductor was formed in the film by the shape of the inductor so that the magnetic field having no directivity such as not penetrating the predetermined conductive film was generated due to the skin effect of the predetermined conductive film at the beginning of polishing. It is possible to suppress generation of eddy currents and to minimize the Joule heat loss caused by the eddy currents without exerting a strong magnetic flux even to minute wirings. Then, as the polishing progresses, after the predetermined conductive film becomes a film thickness corresponding to the skin depth, a leakage magnetic flux that penetrates the predetermined conductive film is caused, and the eddy current changes due to the change of the leakage magnetic flux. Based on the change in the mutual inductance occurring in the inductor, the mutual inductance for detecting the end point of polishing immediately before the end point of polishing is detected. Therefore, there is an advantage that the polishing completion point can be accurately predicted and detected from this change portion.

According to the invention described in claim 17, the inductor in the high frequency inductor type sensor is brought close to a predetermined conductive film, and at least part of the magnetic fluxes formed by the inductor in the initial polishing stage is determined by the skin effect of the predetermined conductive film. An inductor shape that generates a magnetic field without directivity that does not penetrate a predetermined 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 at least a portion of the inductor as the polishing progresses. The sensor in the high frequency inductor type sensor which has at least one process of increasing the magnetic flux penetrating the conductive film of the inductor and is based on the change of the leakage magnetic flux penetrating the predetermined conductive film during the polishing of the magnetic flux formed by the inductor. The inductance of the circuit system changes with this inductance The resonance frequency is monitored as a change in the resonance frequency determined by the intrinsic capacity of the system, and the resonance frequency for predicting the end point of polishing based on the change in the resonance frequency when the film thickness during polishing becomes the film thickness corresponding to the skin effect is obtained. Since the change portion was detected and the polishing end point was predicted from the change portion, the inductor had such a shape that it would not penetrate the predetermined conductive film due to the skin effect of the predetermined conductive film at the beginning of polishing. By generating a magnetic field having no directivity, generation of an eddy current is suppressed without a strong magnetic flux even to fine wirings or the like formed in the film, and the Joule heat loss due to this eddy current can be minimized. Then, as the polishing progresses, after the predetermined conductive film becomes a film thickness corresponding to the skin depth, a leakage magnetic flux that penetrates the predetermined conductive film is caused, and the inductance of the sensor circuit system according to the change of the leakage magnetic flux is caused. The change portion of the resonance frequency for predicting the polishing end point immediately 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. Therefore, there is an advantage that the polishing completion point can be accurately predicted and detected from this change portion.

According to the invention described in claim 18, the inductor of the high frequency inductor type sensor is brought close to a predetermined conductive film, and at least part of the magnetic fluxes formed by the inductor in the initial polishing stage is determined by the skin effect of the predetermined conductive film. An inductor shape that generates a magnetic field without directivity that does not penetrate a predetermined 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 at least a portion of the inductor as the polishing progresses. Has at least once a process of increasing the magnetic flux penetrating the conductive film, and due to the change of the eddy current caused by the change of the leakage magnetic flux penetrating the predetermined conductive film during the polishing of the magnetic flux formed by the inductor, Change in mutual inductance occurring in the inductor, or the mutual The change of the resonant frequency oscillated from this high frequency inductor sensor due to the change in inductance of the sensor circuit system in the high frequency inductor sensor based on the change of inductance is monitored, and the film thickness during polishing is Since a change portion for predicting the polishing end point is detected based on at least one change among the respective changes when the film thickness corresponding to the skin effect is achieved, and the polishing end point is predicted from this change portion. From the inductor, due to its shape, a magnetic field having no directivity such as not penetrating through the predetermined conductive film is generated due to the skin effect of the predetermined conductive film at the initial stage of polishing, thereby increasing the resistance to fine wirings formed in the film. Without the magnetic flux, and the generation of eddy current is suppressed, The heat loss can be minimized. Then, as the polishing progresses, after a predetermined conductive film becomes a film thickness corresponding to the skin depth, a leakage magnetic flux that penetrates the predetermined conductive film is caused, and the eddy current change and mutual inductance caused by the change of the leakage magnetic flux are caused. The change portion immediately before the polishing end point is detected based on a change in at least one of a change in or a change in resonant frequency oscillated from the high frequency inductor type sensor. Therefore, there is an advantage that the polishing completion point can be accurately predicted and detected from this change portion.

Invention of Claim 19 respond | corresponds to the said skin depth during each change of the said eddy current, the said mutual inductance, or the said resonance frequency, when the film thickness of the said predetermined conductive film during grinding | polishing becomes a film thickness corresponding to skin depth. The peaks (peaks) are generated by two phenomena: the increase in the eddy current caused by the increase in the leakage flux caused by the film thickness and the decrease in the eddy current forming area due to the decrease in the film thickness volume by polishing. Since the change portion for predicting the end point of polishing was detected on the basis, in addition to the effect of the invention described in claim 17, as the polishing was further progressed, the predetermined conductive film became a film thickness corresponding to the skin depth. Thereafter, significant peaks (peaks) occur during each change in eddy current, mutual inductance, or resonance frequency. Therefore, based on this remarkable maximum point (peak), it is possible to accurately detect the change portion for predicting the end point of polishing. Therefore, there is an advantage that the polishing completion point can be predicted and detected more accurately from this change portion.

According to the invention of claim 20, the inductor of the high frequency inductor type sensor is brought close to a predetermined conductive film, and at least part of the magnetic fluxes formed by the inductor in the initial polishing stage is determined by the skin effect of the predetermined conductive film. The frequency of not penetrating a predetermined conductive film is oscillated from the high frequency inductor sensor, and at least once during polishing, a process of increasing the magnetic flux penetrating the at least part of the conductive film in accordance with the progress of polishing is formed by the inductor. The change of the leakage magnetic flux which penetrates the said predetermined | prescribed electroconductive film | membrane during the progress of grinding | polishing among the magnetic fluxes which are used, and a grinding | polishing end timing is estimated from the change of the leakage magnetic flux when the film thickness during grinding | polishing becomes the film thickness corresponding to the said skin effect. Detects the change part of the leakage magnetic flux to Since the polishing rate and the remaining film thickness to be removed are calculated at the seat, the leakage magnetic flux that penetrates the predetermined conductive film after the predetermined conductive film becomes a film thickness corresponding to the skin depth with the progress of polishing is obtained. In this case, this change portion immediately before the polishing end point is detected from the change in the leakage magnetic flux. Therefore, the polishing data such as the remaining film amount and the polishing rate to be removed can be accurately calculated on the basis of the change portion, and it is possible to accurately evaluate whether the predetermined conductive film is properly removed and leak at the same time. There is an advantage that the Joule heat loss caused by the eddy current generated by the magnetic flux can be minimized.

According to the invention described in claim 21, the inductor of the high frequency inductor type sensor is brought close to a predetermined conductive film, and at least part of the magnetic fluxes formed by the inductor in the initial polishing stage is determined by the skin effect of the predetermined conductive film. The frequency of not penetrating a predetermined conductive film is oscillated from the high frequency inductor sensor, and at least once during polishing, a process of increasing the magnetic flux penetrating the at least part of the conductive film in accordance with the progress of polishing is formed by the inductor. The change of the leakage magnetic flux which penetrates the said predetermined | prescribed electroconductive film during the progress of polishing among the magnetic fluxes which are used as a change of the eddy current which this leakage magnetic flux produces, and the said eddy current when the film thickness during grinding | polishing becomes the film thickness corresponding to the said skin effect. The change portion of the eddy current to predict the end point of polishing from the change of Since the detection was performed to calculate the polishing rate and the remaining film thickness to be removed on the basis of the changed portion, after the predetermined conductive film became the film thickness corresponding to the skin depth as the polishing proceeded. The leakage magnetic flux that penetrates the predetermined conductive film is caused to be caused, and the change portion immediately before the polishing end point is detected from the change of the eddy current caused by the change of the leakage magnetic flux. Therefore, the polishing data such as the remaining film amount and polishing rate to be removed on the basis of this change portion can be calculated accurately on the spot, and there is an advantage that it is possible to accurately evaluate whether the predetermined conductive film is properly removed. .

According to the invention described in claim 22, the inductor in the high frequency inductor type sensor is brought close to a predetermined conductive film, and at least part of the magnetic fluxes formed by the inductor in the initial polishing stage is caused by the skin effect of the predetermined conductive film. The frequency of not penetrating the predetermined conductive film is oscillated from the high frequency inductor type sensor, and at least once during polishing, the magnetic flux penetrating through the at least part of the conductive film increases as the polishing proceeds. The change of the eddy current caused by the change of the leakage magnetic flux which penetrates the said predetermined | prescribed electroconductive film during grinding | polishing of the magnetic flux formed is monitored as a change of mutual inductance which arises in the said inductor by this eddy current, and the film thickness during grinding | polishing is the said skin effect In the mutual inductance when the film thickness corresponding to Since the variation part of mutual inductance for predicting the completion | finish point of grinding | polishing was detected, and based on this change part, the grinding | polishing rate and the remaining film thickness to be removed were calculated on the spot, and the predetermined | prescribed challenge is performed according to progress of grinding | polishing. After the film formation becomes the film thickness corresponding to the skin depth, the leakage magnetic flux penetrating the predetermined conductive film is caused, and the polishing end point is changed from the change of mutual inductance generated in the inductor due to the change of the eddy current caused by the change of the leakage magnetic flux. The portion of change immediately preceding is detected. Therefore, the polishing data such as the remaining film amount and polishing rate to be removed on the basis of this change portion can be calculated accurately on the spot, and there is an advantage that it is possible to accurately evaluate whether the predetermined conductive film is properly removed. .

According to the invention of claim 23, the inductor of the 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 polishing stage is determined by the skin effect of the predetermined conductive film. At least once during polishing, a frequency of not penetrating a predetermined conductive film is oscillated from the high frequency inductor type sensor, and a magnetic flux penetrating through the at least part of the conductive film increases as polishing progresses. The change in inductance of the sensor circuit system in the high frequency inductor sensor based on the change of the leakage magnetic flux that penetrates the predetermined conductive film during the progress of polishing among the magnetic fluxes formed is defined as the inductance and the intrinsic capacitance of the sensor circuit system. Loss is monitored as a change in resonant frequency, and the film thickness during polishing is From the change in the resonant frequency when the film thickness corresponds to the skin effect, the portion of change in the resonant frequency for predicting the end point of polishing is detected, and on the basis of this change, the polishing rate and the remaining film to be removed. Since the amount of thickness was calculated, the leakage magnetic flux penetrating the predetermined conductive film was caused to occur after the predetermined conductive film became the film thickness corresponding to the skin depth as the polishing progressed, resulting in the change of the leakage magnetic flux. The change portion immediately before the polishing end point is detected based on the change in the resonance frequency oscillated from the high frequency inductor type sensor due to the change in inductance of the sensor circuit system. Therefore, the polishing data such as the remaining film amount and polishing rate to be removed from this change portion can be calculated accurately on the spot, and there is an advantage that it is possible to accurately evaluate whether the predetermined conductive film is properly removed.

The invention according to claim 24 is characterized by the skin effect during each change in the eddy current, the mutual inductance, or the resonance frequency when the film thickness of the predetermined conductive film during polishing is equal to or close to the skin depth. Since two phenomena, namely, an increase in the eddy current due to the increase of the leakage magnetic flux and a decrease in the eddy current due to the decrease in the film thickness volume due to polishing, are caused to have a peak, and the film thickness reference point is detected based on the peak. In addition to the effects of the invention as set forth in claim 20, 21 or 22, as the polishing proceeds further, the angle of the eddy current, mutual inductance, or resonance frequency after the predetermined conductive film becomes a film thickness corresponding to the skin depth. Since a significant peak occurs during the change, the edge for predicting the end point of polishing based on this significant peak is The part of the picture can be detected accurately. Therefore, the polishing data such as the remaining film amount and polishing rate to be removed on the basis of this change portion can be calculated more precisely on the spot, and it is possible to accurately evaluate whether the predetermined conductive film is properly removed. There is this.

The invention according to claim 25 has a high-frequency inductor type sensor having an oscillation circuit constituting a sensor circuit system consisting of a planar inductor and a capacitor, and polishes the conductive film to finish polishing when the predetermined conductive film is properly removed. As a prediction / detection device at the end of polishing for predicting and detecting a, claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17 or Since the prediction / detection method at the polishing end point described in 18 is executed, the prediction / detection device at the polishing end point having a high frequency inductor type sensor having an oscillation circuit constituting a sensor circuit system composed of a planar inductor and a capacitor, As the polishing progresses, after the predetermined conductive film becomes a film thickness corresponding to the skin depth, a leakage magnetic flux that penetrates the predetermined conductive film is caused. At least one of the change in the eddy current caused by the change in speed, the change in mutual inductance generated in the planar inductor due to the change in the eddy current, or the change in the resonance frequency generated from the high frequency inductor type sensor due to the change in inductance of the sensor circuit system. Based on the change, the portion of the waveform change for predicting the end point of polishing immediately before the end point of polishing is detected. Therefore, the polishing end point can be accurately predicted and detected from this waveform change portion, and the joule heat loss caused by the eddy current generated by the leakage magnetic flux can be minimized.

The invention as set forth in claim 26 has a high-frequency inductor type sensor having an oscillation circuit constituting a sensor circuit system consisting of a planar inductor and a capacitor, and the conductive film is polished to evaluate whether the predetermined conductive film is properly removed. A sensor circuit system comprising a planar inductor and a capacitor because a real-time film thickness monitor apparatus for monitoring a film thickness change during polishing is performed by executing the real-time film thickness monitor method according to claim 19, 20, 21, 22, or 23. The real-time film thickness monitor device having a high frequency inductor type sensor having an oscillation circuit constituting the semiconductor device penetrates through the predetermined conductive film after the predetermined conductive film becomes a film thickness corresponding to the skin depth as the polishing proceeds. To cause leakage magnetic flux to be generated, resulting from the change of the leakage magnetic flux and the change of the leakage magnetic flux. Polishing end point from at least one of the change of the eddy current, the change of the mutual inductance which arises in a planar inductor by the change of this eddy current, or the change of the resonance frequency oscillated from a high frequency inductor type sensor by the change of the inductance of a sensor circuit system. The portion of the waveform change for predicting the end point of polishing immediately before is detected. Therefore, the polishing data such as the remaining film amount and the polishing rate to be removed can be accurately calculated on the basis of the waveform change portion, and it is possible to accurately evaluate whether the predetermined conductive film is properly removed. At the same time, there is an advantage that the Joule heat loss caused by the eddy current generated by the leakage magnetic flux can be minimized.

While minimizing Joule heat loss due to eddy currents, it is possible to accurately predict and detect the end point of polishing, and to accurately calculate the remaining film amount and polishing rate to be removed on the spot, and the predetermined conductive film is properly In order to achieve the objective of accurately evaluating whether it has been removed, the conductive film is polished to predict and detect the polishing end point when the predetermined conductive film is properly removed. The inductor of the high-frequency inductor type sensor is brought close to the conductive film of the film, and the change of the magnetic flux caused by the predetermined conductive film is monitored by the magnetic flux formed by the inductor, and the film thickness during polishing is the material of the predetermined conductive film. Predict the end point of polishing based on the change in the magnetic flux due to the skin effect Detecting a magnetic flux change portion for groups, which was achieved by predicting the polishing end point from the change portion.

Example 1

EMBODIMENT OF THE INVENTION Hereinafter, the prediction / detection method and the apparatus of the polishing completion time which concerns on Example 1 of this invention are explained in full detail according to drawing. 1 is a perspective view of a chemical mechanical polishing apparatus equipped with a prediction and detection device at the end of polishing, FIG. 2 is an enlarged longitudinal sectional view of the polishing head, and FIG. 4 is a schematic side view showing a partially broken view for explaining a state in which the predicting / detecting device at the end of polishing is mounted on the polishing head.

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

As shown in FIG. 2, the polishing head 3 mainly includes the head body 7, the carrier 8, the retainer ring 9, the retainer ring pressurizing means 10, the elastic sheet 11, and the carrier pressurizing means. 16, and control means, such as air.

The head body 7 is formed in a disk shape smaller than that of the platen 2, and a rotating shaft 12 (see Fig. 1) is connected to the center of the upper surface thereof. The head main body 7 is pivoted on the rotation 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 disk shape and is disposed at the center of the head body 7. The dry plate 13 is formed between the upper surface center part of this carrier 8 and the center lower part of the head main body 7, and rotation is transmitted from the head main body 7 via the pins 14 and 14. As shown in FIG.

An actuating 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 an actuating transformer 15 is attached to the center upper part of the carrier 8. The core 15b is fixed and connected to a control unit (not shown) and outputs a polishing state signal of a conductive film made of Cu or the like formed on the wafer W (downward side in FIG. 2) to the control unit.

A carrier pressing member 16a is formed at the upper periphery of the carrier 8, and the carrier 8 transmits a pressing force from the carrier pressing means 16 via the carrier pressing member 16a.

On the lower surface of the carrier 8, an air jet port 19 for injecting air to the elastic sheet 11 in the air float line 17 is formed. 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. The blowing of air from the air blowing port 19 is executed by switching of the automatic opening and closing valve V1.

The lower surface of the carrier 8 is formed with a hole 22 for blowing out DIW (pure water) or air if necessary. Suction of this air is performed by the drive of the vacuum pump 23, and the automatic opening / closing valve V2 is formed in the vacuum line 24, and this vacuum line 24 is switched by switching of this automatic opening / closing valve V2. Through this, feeding of vacuum and DIW is performed.

The air supply from the air float line 17, the action of the vacuum from the vacuum line 24, the supply of DIW, and the like are executed by command signals from the controller.

In addition, the carrier pressurizing means 16 is disposed at the periphery 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. This carrier pressurizing means 16 is comprised from the rubber seat airbag 25 which expands and contracts preferably with the intake and exhaust of air. An air supply mechanism (not shown) for supplying air is connected to this air bag 25.

The retainer ring 9 is formed in a ring shape and is disposed on the outer circumference of the carrier 8. The retainer ring 9 is attached to a retainer ring holder 27 formed on the polishing head 3, and the elastic sheet 11 is tensioned in its inner circumference.

The elastic sheet 11 is formed in a circular shape, and a plurality of holes 22 are drilled. The elastic sheet 11 has a peripheral portion sandwiched between the retainer ring 9 and the retainer ring holder 27, and is tensioned inside the retainer ring 9.

An air chamber 29 is formed between the carrier 8 and the elastic sheet 11 at a lower portion of the carrier 8 in which the elastic sheet 11 is provided in tension. The wafer W on which the conductive film is formed is pressed to the carrier 8 through the air chamber 29. The retainer ring holder 27 is attached to the attachment member 30 formed in a ring shape via a snap ring 31. The retainer ring pressing member 10a is connected to this attachment member 30. The pressing force from the retainer ring pressurizing means 10 is transmitted to the retainer ring 9 via this retainer ring pressurizing member 10a.

The retainer ring pressurizing means 10 is disposed on the outer circumferential portion of the lower surface of the head main body 7, and applies a pressing force to the retainer ring pressurizing member 10a, thereby attaching the retainer ring 9 coupled thereto to the polishing pad 6. Pressurize. This retainer ring pressurizing means 10 is also preferably comprised of the rubber sheet airbag 16b similarly to the carrier pressurizing means 16. An air supply mechanism (not shown) for supplying air is connected to this air bag 16b.

3 or 4, the prediction of the end point of polishing is performed on the portion of the upper platen 2 or the portion of the carrier 8 of the polishing head 3 in the chemical mechanical polishing apparatus 1. One detection device 33 is mounted. When the predicting / detecting device 33 at the polishing end point is mounted on the platen 2 side, a detection signal such as a waveform change portion that predicts the polishing ending point from the predicting / detecting device 33 at this polishing end point. Is output to the outside via the slip ring 32.

In addition, you may attach two or more prediction / detection apparatuses 33 at the time of grinding | polishing end to the part of the platen 2 upper part, or the part of the carrier 8 of the polishing head 3, respectively. By mounting two or more prediction / detecting devices 33 at the end of polishing and collecting the film thickness information in time series from the prediction / detecting device 33 at the end of polishing in the rotational direction front side, the wafer W surface Distribution information of the film thickness change of the electroconductive film 28 in the inside, etc. are obtained.

5 is a diagram showing an example of the configuration of the prediction / detecting device 33 at the end of polishing, FIG. 5A is a block diagram, and FIG. (C) is sectional drawing of the planar inductor of FIG. The oscillation circuit 35 constituting the main body of the high frequency inductor type sensor 34 in the predicting / detecting device 33 at the end of polishing is a two-dimensional planar inductor 36 that becomes an inductance L. The lumped constant capacitor 37 which becomes the capacitance Co is connected in series to each other, and the LC circuit is configured. The planar inductor 36 is formed in a meander shape using a conductive material such as Cu on a substrate 36a such as a rectangular shape made of an insulator.

The planar inductor 36 may be formed in a meander shape on the rectangular substrate 41a, like the planar inductor 41 shown in Fig. 5B, in addition to the spiral type shown in Fig. 5A. good. In addition, it is good also as a circular spiral not shown. The two-dimensional planar inductors 36 and 41 form a line width by forming a conductive film such as Cu on the substrates 36a and 41a made of an insulator such as glass, epoxy, paper, or phenol, followed by etching. It can be made very fine and the whole shape can also be miniaturized to a square shape of about 23 mm on one side as shown in Fig. 5C. Further, by miniaturizing the planar inductors 36 and 41, a minute magnetic field can be efficiently generated, and the end point from which the conductive film 28 is removed without penetrating the magnetic field deeply into the conductive film 28. The change behavior in the vicinity can be detected with high accuracy.

The output signal from the LC circuit is input to an amplifier 38 composed of an operational amplifier or the like, and the 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 formed including the planar inductor 36.

As shown in the structural example of FIG. 6, this oscillation circuit 35 basically has the inductance L of the planar inductor 36 as the oscillation frequency band f is shown by following formula (1). And an oscillation circuit such as a Colpitt type determined by the capacitance Co of the lumped constant capacitor 37.

[Equation (1)]

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

A high frequency inductor type sensor 34 including the planar inductor 36 and the frequency counter 40 are included, and the prediction / detecting device 33 at the end of polishing is configured. By arranging the oscillation circuit 35 in the high frequency inductor type sensor 34 and the frequency counter 40 for monitoring the change of the oscillation (resonance) frequency, the oscillation circuit 35 and the frequency counter ( The distribution constant circuit is formed in the wiring / connection part between the parts 40, thereby preventing the inductance and the capacitance from becoming unnecessarily large, and the change of the magnetic flux due to the progress of polishing of the conductive film 28 caused in the vicinity of the high frequency inductor type sensor 34. Can be detected with high accuracy.

In the predicting / detecting device 33 at the end of polishing, other components or circuits except for the planar inductor 36 are integrated into the package 33a by forming an IC (integrated circuit). The planar inductor 36 is covered with a thin insulating film and fixed to the surface of the package 33a. When the predictive / detection apparatus 33 at the end of packaged polishing is mounted on the chemical mechanical polishing apparatus 1, as shown in Figs. 3 and 4, the planar inductor 36 has a wafer W surface. It is mounted so as to be opposed to the negative conductive film 28.

The lumped constant capacitor 37 constituting the oscillation circuit 35 has a variable capacitance, so that the high frequency inductor type sensor 34 can select an oscillation frequency within the oscillation frequency band.

In this embodiment, the polishing end point to be described later is predicted based on the magnetic flux change when the predetermined conductive film 28 during polishing becomes the 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 depends on the material of the predetermined conductive film 28 and the oscillation frequency f of the high frequency inductor type sensor 34 as shown in equation (2). It is decided.

[Equation (2)]

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

Then, the skin depth δ is smaller than the initial film thickness of the predetermined conductive film 28 and is larger than the film thickness of the predetermined conductive film 28 in the portion except the buried portion in the polishing end (high frequency inductor type sensor) The oscillation frequency f of 34 is selected. In the case where 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 more.

In addition, even when the frequency is selected as a high frequency and the inductor is a planar inductor, the characteristics of the waveform due to the skin effect may or may not appear depending on the distance between the inductor and the conductive film and the shape of the inductor. have. For example, using the same planar inductor using a frequency of 40 MHz, one inductor should have a size of 1/1000 for the actual inductor and a distance of 1/1000 for the distance between the inductor and the conductive film, Also, even when the same frequency of 40 MHz and the 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 has no peak at a 1/1000 size, distance inductor, and monotonously increases with respect to the film thickness. In the inductor of the actual size, most of the magnetic flux is parallel to the surface of the conductive film, and the magnetic flux does not pass through the film. That is, under the influence of the epidermal effect, no magnetic flux enters the conductor film. In contrast, in an inductor having a size and distance of 1/1000, magnetic flux penetrates through the conductive film. In this inductor size, the effect of the skin effect does not work. Therefore, as the film thickness increases, the eddy current monotonously increases, and accordingly, the mutual inductance (impedance) also increases. Therefore, even if the same planar inductor is used with the same frequency, the effect of the skin effect may or may not appear depending on its size and distance. Here, a state in which such an effect of the skin effect appears is produced in the film thickness reduction process by polishing, and the end point is predicted and detected in the state. In addition, the film thickness range which the skin effect in this case affects does not correspond with the skin depth (delta) shown by said Formula (2) simply determined by the frequency and the material (conductivity and permeability) of a conductive film.

This is because, as described above, the skin effect is also changed depending on the size and distance of the inductor, and therefore, the effect is also caused by the direction (directivity) of the magnetic field. However, as shown in the above equation, when the frequency, the electrical conductivity, and the permeability increase, the relationship itself that the distance that the magnetic field can penetrate becomes smaller satisfies the relationship of the above equation and corresponds. Therefore, the film thickness range itself in which the skin effect appears is a value corresponding to the skin depth δ of the above formula. Therefore, the characteristic waveform based on the skin effect here means that magnetic flux rarely invades the conductive film under certain conditions, depending on frequency, electrical conductivity, permeability, magnetic field directivity, and the like, and magnetic flux penetrates the conductive film under other conditions. It is a characteristic waveform change obtained by using the remarkable change of state such as.

Here, the "film thickness corresponding to epidermal depth" and the "change in magnetic flux caused by the epidermal effect" will be described with reference to FIGS. 7A to 7D. FIG. 7 is a diagram showing the result of an electronic simulation of the magnetic field generated from the coils arranged in a direction (arrow → in each of Figs. 7A to 7D) on the conductor film. 7 (A) 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, and FIG. 7 (B) shows the case where the oscillation frequency from the sensor is 1 MHz and the film thickness of the conductor film is 1 μm. 7 (C) 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. 7 (D) 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 electronic simulation, the inductor forming the magnetic field was a planar inductor having no directivity. Said "film thickness corresponding to epidermal depth" is "film thickness in which a magnetic flux change arises by an epidermal effect." When the oscillation frequency of the sensor is 1 MHz, the magnetic flux on the conductor film existing under the coil is directed in the longitudinal direction. At this frequency, even if the film thickness is 1 µm and 0.2 µm, the magnetic flux penetrates the inside of the conductor film (Figs. 7 (A) and 7 (B)). In the case where the magnetic flux penetrates the inside of the 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 it is monotonous at the film thickness of 1 micrometer or less, an epidermal effect does not appear and it is thought that "film thickness corresponding to epidermal depth" is also thicker than at least 1 micrometer.

On the other hand, when the oscillation frequency of the sensor was 40 MHz, the magnetic flux direction on the conductor surface was clearly horizontal, and when the film thickness was 1 탆, almost no inside of the conductor was entered (Fig. 7 (D)). Obviously, when the preceding oscillation frequency is 1 MHz and the film thickness is 1 m (Fig. 7 (B)), it can be seen that the directions of the magnetic flux entering the conductor film are different.

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

In the case of this alternating flux of 40 MHz, the penetrating state of the magnetic flux in the conductive film changes in response to the skin effect. Due to the gradual increase in the penetrating magnetic flux, the frequency rapidly rises to about 700 Hz. When the film thickness is 1 µm or more, the magnetic flux hardly penetrates. Therefore, in this case, the "film thickness corresponding to the epidermal depth" can be said to be about 1 µm when the film thickness of the boundary between the magnetic flux penetrates and does not penetrate. Also from this fact, when the oscillation frequency is increased to 40 MHz and a planar inductor is used, the magnetic flux hardly enters the Cu conductor film having a thickness of 1 탆, which is due to the skin effect.

When the Cu conductor film has an oscillation frequency of 40 MHz, the skin depth δ is 9.34 µm when the conductivity of Cu is 58x10 ⁶ S / m. In calculations, when the film thickness is 1 µm, the magnetic flux is sufficiently calculated into the conductor film. However, since a planar inductor is used and the magnetic flux has no directivity, when the oscillation frequency is 40 MHz, the film thickness is 1 µm. Even if the epidermis effect, the magnetic field does not penetrate into the conductor film. As the conductor film becomes thinner, some magnetic flux enters the conductor film and slightly eddy current is generated. From this fact, rather than actively using the eddy current to measure the film thickness, when the film thickness reaches the thin film thickness near the end point, it is mutually induced in the conductor film by using a magnetic flux that slightly leaks and penetrates due to the skin effect. By using the inflection point (maximum point) of the inductance, it is possible to monitor the film thickness state near the end point of the conductor film.

Next, the grinding | polishing effect | action of the chemical mechanical polishing apparatus with which the prediction and detection apparatus of the polishing end time comprised as mentioned above was equipped, and the prediction and detection method of the polishing end time are shown to FIG. 8, FIG. 9 (A)-FIG. 9 ( E) and FIG. 10 (A)-FIG. 10 (E) as a comparative example of this FIG. 9 are demonstrated. 8 is a view for explaining the effect of the magnetic field generated by the electromagnetic coupling in the high-frequency inductor sensor, Figure 9 is a prediction of the change of the magnetic flux and eddy current according to the polishing erase of the conductive film and the polishing end point 9 (A) to 9 (D) are diagrams showing examples of changes in magnetic flux and eddy current due to polishing removal of the conductive film, and FIG. 9 (E). Is a characteristic diagram which shows the example of a change of the resonance frequency with respect to the film thickness change of an electroconductive film. In Figs. 9A to 9D, the planar inductor 36 is shown in a spiral shape in order to make the drawing easier to see.

First, the electrically conductive film 28 waiting in a predetermined position is mounted on the non-abrasive wafer W by the moving mechanism which does not show the polishing head 3 in the chemical mechanical polishing apparatus 1. Then, the vacuum line 24 of the polishing head 3 is operated to vacuum the air chamber 29 on the lower surface of the elastic sheet 11 through the vacuum holes 19a and the holes 22 (vacuum holes). This causes the conductive film 28 to adsorb and hold the non-abrasive wafer W, and the polishing mechanism allows the conductive film 28 to adsorb and hold the non-abrasive wafer W by the moving mechanism. (3) is carried on the platen 2, and the wafer W is mounted on the platen 2 so that the conductive film 28 serves the polishing pad 6.

When the polishing operation of the conductive film 28 on the wafer W is finished, the vacuum line 24 again transfers the wafer W to the polishing head 3 by the operation of the vacuum line 24. It is used also when it carries out adsorption hold | maintain by the and conveys to the washing | cleaning apparatus which is not shown in figure.

Next, the operation of the vacuum line 24 is released to inflate the airbag 25 by supplying air to the airbag 25 from a pump (not shown). At the same time, air is supplied to the air chamber 29 from the air jet port 19 formed in the carrier 8. As a result, the internal pressure of the air chamber 29 is increased.

As the airbag 25 is inflated, the conductive film 28 and the retainer ring 9 on the wafer W are pressed against the polishing pad 6 at a predetermined pressure. In this state, the platen 2 is rotated in the direction of the arrow A of FIG. 1 and the polishing head 3 is rotated in the direction of the arrow B of FIG. 1 to remove the nozzle from the nozzle (not shown) on the rotating polishing pad 6. The slurry is supplied to polish a predetermined conductive film 28 on the wafer W.

Then, the film thickness change of the predetermined conductive film 28 due to polishing is monitored by the magnetic flux formed by the planar inductor 36 in the high frequency inductor type sensor 34 to predict the end point of polishing. The waveform change portion to be detected is detected.

The planar inductor 36 is driven at a high frequency oscillated from the oscillation circuit 35, and from this planar inductor 36, a magnetic flux? That changes in time corresponding to the period of the high frequency is generated. In the initial stage of polishing, the magnetic flux φ induced by the predetermined conductive film 28 passes almost parallel along the film surface only in a region having a film thickness corresponding to the skin depth δ, and the predetermined conductive film 28 Intrusion of the magnetic flux φ into the region exceeding the film thickness corresponding to the epidermal depth δ at is avoided (FIG. 9A). In addition, the resonant frequency oscillated from the high frequency inductor type sensor 34 is also kept constant regardless of the change in the film thickness of the predetermined conductive film 28 (region a in Fig. 9E).

When the polishing proceeds so that the predetermined conductive film 28 is equal to or close to the film thickness corresponding to the skin depth δ, a part of the magnetic flux φ penetrates the predetermined conductive film 28. The leakage magnetic flux φ _L starts to occur. The magnetic flux φ which does not penetrate the predetermined conductive film 28 passes through it almost in parallel with the membrane surface. Then, an eddy current Ie is generated in proportion to the number of leaked magnetic fluxes? _L penetrating into the predetermined conductive film 28 (Fig. 9 (B)).

As the polishing proceeds further, the leakage magnetic flux φ _L increases so that the eddy current Ie occurs in a wide area along the film surface of the conductive film 28 (Fig. 9 (C)). As shown in FIG. 8, the eddy current Ie generated in this wide area further creates a magnetic field M, and the magnetic field M eliminates the magnetic flux φ _L generated from the original planar inductor 36. Works. As a result, mutual inductance Lm increases by the magnetic field M formed by the conductive film 28, 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 is increased as in Equation (3).

[Equation (3)]

Therefore, due to the generation of mutual inductance, the inductance of the sensor circuit system is reduced equivalently, so that the resonance frequency oscillated from the high frequency inductor type sensor 34 rises (areas b and c in Fig. 9E).

As polishing proceeds further, the leakage flux φ _L increases and saturates. However, the eddy current Ie decreases rapidly as the film thickness volume of the predetermined conductive film 28 decreases (Fig. 9 (D)). Due to this rapid decrease in eddy current Ie, the mutual inductance also decreases rapidly. This rapid reduction in mutual inductance leads to a decrease in the reduction Lm of the inductance in Equation (3). As a result, the inductance of the sensor circuit system increases equivalently and oscillates from the high frequency inductor type sensor 34. The resonance frequency to be lowered rapidly (d region in Fig. 9E).

As described above, after the predetermined conductive film 28 becomes equal to or close to the film thickness corresponding to the skin depth δ in accordance with the progress of polishing, the eddy current Ie is generated and rapid after that. Due to the reduction, the inductance of the sensor circuitry once decreases and then changes to increase. This behavior generates a peak (inflection point) in the waveform of the resonance frequency oscillated from the high frequency inductor sensor 34. Based on this peak, the waveform change portion P immediately before the polishing end point is detected, and the polishing end point is predicted from this waveform change portion P. FIG. In the case where the predetermined conductive film 28 is Cu, the remaining film amount at the time when the waveform change portion P is detected is about 1000 GPa, and finish polishing or the like is performed on the remaining film amount to finish polishing.

As this finish polishing, for example, from the waveform change portion P, the film thickness corresponding to the skin depth, which is the remaining film amount in the waveform change portion P, is polished by the polishing time set in advance at the required polishing rate. After that, polishing is finished. Or from the initial grinding | polishing to the time until the said waveform change part P is detected, and the grinding | polishing amount until it reaches this waveform change part P, the polishing rate in between is computed, and the said waveform The required polishing time after detecting the waveform change portion P is calculated by dividing the film thickness corresponding to the skin depth that is the remaining film amount in the change portion P by the polishing rate. After the detection of the change portion P, the polishing is finished by polishing for the calculated polishing time.

Next, the comparative example of FIG. 10 (A)-FIG. 10 (E) is demonstrated. In this comparative example, the frequency at which the film thickness corresponding to the skin depth δ is larger than the initial film thickness of the conductive film 28 is applied. This frequency applied by being while monitoring the film thickness change to the polishing end from, polishing early, that is the magnetic flux (φ) is a constant leakage magnetic flux by both the through the conductive film 28, causing the conductive film 28 (φ _L ) Is occurring. Therefore, while monitoring the film thickness change, the eddy current Ie in proportion to the leakage magnetic flux? _L is generated (Figs. 10 (A) to 10 (D)). For this reason, a large mutual inductance is generated between the conductive film 28 and the planar inductor by this eddy current Ie, and the oscillation frequency f oscillated from the sensor by the reduction Lm of the inductance due to this mutual inductance. ) Becomes like the above formula (3) from the beginning of polishing.

As the film thickness decreases due to the progress of polishing, the eddy current Ie decreases rapidly (Figs. 10 (B) to 10 (D)), and the mutual inductance decreases, thereby reducing the inductance in Equation (3). The decrease Lm also decreases. As a result, the inductance of the sensor circuit system increases equivalently, and the resonance frequency oscillated from the sensor monotonously decreases (Fig. 10 (E)).

As described above, in the comparative example, since the resonance frequency draws a monotonic reduction curve, the amount of reduction in film thickness from the beginning of polishing can be estimated, but it is not possible to strictly determine the state at the end of polishing or immediately before the end of polishing. For example, when the stray capacitance C is changed by a subtle setting, the overall resonance frequency of FIG. 10E shifts up and down over the entire waveform. For this reason, even if the polishing end point is set when a certain frequency is reached, the threshold value cannot be set if the resonance frequency shifts as a whole. Moreover, even if the state of the removal amount from the initial film thickness is monitored in real time by the change in the eddy current, if there is a deviation in the initial film thickness, there is also a deviation in the film thickness in the state of the polishing end point. Since there is no waveform characteristic, in this case as well, the threshold value cannot be set.

11A to 11D show peaks of the waveform change portion P with respect to two kinds of wafers Wa and Wb in which the conductive film to be polished differs in material and conductivity. The added result is shown. Fig. 11A is a wafer Wa with a Cu film, Fig. 11B is a change characteristic of a resonance frequency with respect to the film thickness of a Cu film, Fig. 11C is a wafer Wb with a tungsten W film. 11 (D) is a diagram showing characteristics of change in resonance frequency with respect to the film thickness of the tungsten (W) film. The sensor outputs of the respective vertical axes in Figs. 11B and 11D correspond to resonance frequencies.

At the same time as both the Cu film and the tungsten (W) film advance the polishing, the resonance frequency increases at one end, and then rapidly decreases to generate a peak (inflection point). The waveform change part P is detected based on this peak (inflection point), respectively. This behavior is obvious from the case of the tungsten (W) film shown in FIG. 11 (D), and the Cu film with a large electrical conductivity shown in FIG. 11 (B) is remarkable.

12 (A) and 12 (B) show the relationship between the film thickness and the resonance frequency when the conductive film to be polished is a Cu film, and FIG. 12 (A) shows the film thickness and resonance according to the progress of polishing. 12 (B) is a diagram showing the relationship between the frequency and the film thickness in the stationary state and the resonance frequency. 12 (A) and 12 (B), the count value of each vertical axis corresponds to the resonance frequency.

In Fig. 12A, the initial film thickness of the Cu film is approximately 1.5 mu m (15000 kPa). In the Cu film, as the polishing progresses, the resonant frequency gradually rises from about 1 μm (10000 Hz), and the waveform change portion P is detected by taking a maximum value around 700 Hz. The resonance frequency drops rapidly after taking the maximum value. In this manner, the remaining film thickness of the Cu film when the waveform change portion P is detected is accurately detected.

In Fig. 12B, the resonance frequency measured for each film thickness of the Cu film in the stationary state shows a maximum value at a film thickness of 710 Hz. Therefore, the film thickness of the Cu film whose maximum resonant frequency in the stationary state is the same as that of the Cu film whose maximum resonant frequency is in progress during the above polishing.

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

First, FIG. 13 is a diagram showing the relationship between the film thickness and the resonant frequency in correspondence with the film thickness. As the most standard predictive detection method at the end of polishing, in the resonance frequency waveform of FIG. 13, a portion corresponding to the peak of the waveform is defined as a film thickness reference value, and the polishing end point is determined based on the film thickness reference value. This is the case. The end point of polishing is defined 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 a waveform corresponds to 710A. In Fig. 13, the waveform of the resonant frequency is monitored to detect a time point when the peak time point is reached. As a method for detecting peaks, since the waveform always undergoes a sudden drop after rising as the film thickness decreases, the peak point may be determined when the resonance frequency is lower than before. In addition, as another method, the peak position may be set to a portion where the differential coefficient is changed to 0 or less or negative while obtaining the differential coefficient at any time.

In the case of FIG. 13, as an initial film, the blanket film which has 16000A Cu film is prepared here, the polishing event at the time of removing this Cu film is predicted, and an end point is detected. In FIG. 13, the film thickness reference point of the remaining 780 A is reached at 89 s after the start of polishing. That is, the amount removed from the beginning is about 16000 A-780 A = 15220 A. If 15290 A has been removed after 89 s, the time required to remove the remaining 780 A is about 4.43 s. That is, when polishing is stopped about 4.5 s after the film thickness reference point detection, the Cu film thickness is almost 0 A, and the polishing can be stopped accurately with the polishing end point. Here, naturally, the premise is that it is removed at a constant polishing rate during polishing.

As another method, it is possible to detect even before the peak position of the resonance frequency. For example, in the present invention, the waveform of the resonant frequency is rapidly raised before reaching the peak point of the resonant frequency. The rate of increase may be set in advance, and the end point of polishing may be predicted when the rate of increase reaches. Alternatively, the time at which the rate of increase is maximized may be monitored in advance, and the time at which the maximum rate of increase is reached may be defined as the film thickness reference point and set from that point. As described above, when the end point is detected at the rising rate, it is effective to display a waveform obtained by differentiating the waveform of the resonance frequency from time to time. When predicting at the point of time when the predetermined rate of increase is reached, the threshold value is set for the differential graph, and the polishing time required until the end point is determined as described above based on the polishing time when the threshold value is reached. Can be inverted.

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

It is possible to predict the end point of polishing in various parts as described above. For example, in the case of showing two different derivative graphs as shown in Fig. 15, the inflection point of the resonance frequency, i.e. In the two differentiation graph, the point which becomes 0 may be defined as a film thickness reference point, and the grinding | polishing end time may be predicted. The polishing time until the end of polishing may be estimated based on the portion where the degree of change of the rate of change of the resonance frequency becomes a predetermined value and the point is a film thickness reference point.

As described above, in the case of obtaining a waveform characteristic peculiar to the surface effect having a behavior in which the resonant frequency rises once and then abruptly decreases as the film thickness decreases due to polishing, it is varied at the time point before the polishing finishes. The characteristic change can be monitored, and on the basis of the change, it is possible to accurately estimate the polishing time up to the end point of polishing. This substantially predicts the polishing end point, but in the case of predicting immediately before polishing end, it is almost the same as detecting the polishing end point.

In addition, in the present embodiment, the waveform change portion P may be detected based on at least one change among mutual inductance, eddy current Ie, and leakage magnetic flux φ _{L in} addition to the resonance frequency. The change in the mutual inductance can be obtained from the change in the oscillation frequency of the high frequency inductor sensor 34 using Equation (3), and since the eddy current Ie is in proportion to the mutual inductance, this eddy current Ie Can be obtained using the change in mutual inductance, and since the leakage magnetic flux φ _L is proportional to the eddy current Ie, the change of the leakage magnetic flux φ _L is the eddy current Ie. It can be obtained by using.

As described above, in the method of predicting and detecting the end point of polishing according to the present embodiment and the apparatus thereof, the predetermined conductive film 28 is immediately before the end of polishing at or near the depth of the skin due to the progress of polishing. Since the leakage magnetic flux φ _L , which is the basis for detecting the waveform change portion P, is generated after the film thickness of the film is reduced, the Joule heat loss due to the eddy current Ie generated by the leakage magnetic flux φ _L is minimized. It can be suppressed.

As the polishing progresses, the angle of the eddy current Ie, mutual inductance, or resonance frequency after the predetermined conductive film 28 becomes equal to or close to the film thickness corresponding to the skin depth δ. Since a significant peak occurs during the change, the waveform change portion P immediately before the polishing end point can be accurately detected based on this significant peak. Therefore, the polishing completion point can be accurately predicted and detected from this waveform change portion P. FIG.

By setting the transmission method of the resonant frequency from the high frequency inductor type sensor 34 to the digital output using the frequency counter 40, the influence of noise and attenuation of the resonant frequency output are prevented, so that the waveform change portion P can be reliably detected. can do.

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

The planar inductor 36, which is a main component of the high frequency inductor type sensor 34, generates little noise and consumes little power, and is relatively inexpensive, so that the cost can be reduced.

Example 2

Hereinafter, the real-time film thickness monitoring method and apparatus thereof according to the second embodiment 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 monitor device. And this real-time film thickness monitor apparatus 33 is attached to the platen 2 or the polishing head 3, as shown in FIG. 3 and FIG.

The real-time film thickness monitoring method by this real-time film thickness monitor apparatus 33 is demonstrated. In the same manner as in the first embodiment, the waveform change portion P immediately before the polishing end point shown in Fig. 9E is detected. The output of this waveform change portion P from the frequency counter 40 is input to a CPU (not shown) or the like, and based on this waveform change portion P, it is necessary to remove almost equivalent to the film thickness corresponding to the skin depth δ. The polishing data such as the remaining film amount, the film thickness already polished and the required time, and the polishing rate are calculated on the spot, and it is evaluated in real time whether the 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 immediately before the polishing end point, the waveform change portion P must be removed based on the waveform change portion P. Each polishing data such as the remaining film amount and the polishing rate can be accurately calculated on the spot, and it is possible to accurately evaluate whether the predetermined conductive film 28 is properly removed. In addition, Joule heat loss due to the eddy current Ie generated by the leakage magnetic flux φ _L can be minimized.

In addition, this invention can make various changes as long as it does not deviate from the mind of this invention, and it is natural that this invention also extends to the modified thing.

BRIEF DESCRIPTION OF THE DRAWINGS The perspective view of the chemical mechanical polishing apparatus with which the prediction and detection apparatus of the grinding | polishing end time which concerns on the Example of this invention was attached.

FIG. 2 is an enlarged longitudinal sectional view of the polishing head in the chemical mechanical polishing apparatus of FIG. 1.

Fig. 3 is a schematic side view showing a partially broken view for explaining a state in which the prediction / detection device at the polishing end point according to the embodiment of the present invention is mounted on the platen.

Fig. 4 is a schematic side view showing a partially broken view for explaining a state in which the predicting and detecting device at the polishing end point according to the embodiment of the present invention is attached to the polishing head.

Fig. 5 is a diagram showing a configuration example of a prediction / detection apparatus at the end of polishing time according to the embodiment of the present invention. Fig. 5 (A) is a block diagram and Fig. 5 (B) shows another configuration example of the planar inductor. Fig. 5C is a cross-sectional view of the planar inductor of Fig. 5B.

FIG. 6: is a figure which shows the basic structural example of the oscillation circuit in the prediction and detection apparatus of the grinding | polishing end time of FIG. 5, FIG. 6 (A) is a block diagram and FIG. 6 (B) is equivalent to FIG. 6 (A). Circuit.

FIG. 7 is a diagram showing an electronic simulation result of which direction the magnetic field generated from the coil is arranged on the conductor film in the embodiment of the present invention. FIG. 7 (A) shows that the oscillation frequency from the sensor is 1 MHz. When the film thickness of the conductor film is 0.2 μm, FIG. 7B shows that the oscillation frequency from the sensor is 1 MHz and the film thickness of the conductor film is 1 μm, FIG. 7C shows that the oscillation frequency from the sensor is 40 MHz. In the case where the film thickness of the conductor film is 0.2 µm, Fig. 7D shows a case where the oscillation frequency from the sensor is 40 MHz and the film thickness of the conductor film is 1 µm.

8 is a configuration diagram for explaining the effect of changing the inductance due to the magnetic field generated by the electromagnetic coupling in the high frequency inductor type sensor according to the embodiment of the present invention.

FIG. 9 is an assembly view for explaining an example of a change in magnetic flux or the like caused by polishing and removal of a conductive film by the chemical mechanical polishing apparatus of FIG. 1 and a detection action of a waveform change portion for predicting the end point of polishing. FIG. 9A to 9D show examples of changes in magnetic flux and the like caused by polishing and removal of the conductive film, and FIG. 9E is a characteristic diagram showing changes in resonant frequency with respect to changes in the film thickness of the conductive film.

Fig. 10 is an assembly view as a comparative example of Fig. 9, in which Figs. 10 (A) to 10 (D) show examples of changes in magnetic flux and eddy current according to polishing removal of the conductive film, and Fig. 10 (E) shows It is a characteristic figure which shows the example of a change of the resonance frequency with respect to a film thickness change.

FIG. 11 is a view illustrating evaluation of peaks that become a waveform change portion for predicting the end point of polishing for a Cu film and a tungsten (W) film in which the conductive film to be polished differs in material and conductivity in the embodiment of the present invention. 11A is a diagram showing a wafer with a Cu film, FIG. 11B is a diagram showing an example of a change characteristic of a resonance frequency with respect to the film thickness of a Cu film, and FIG. W) A diagram showing a wafer with a film, and FIG. 11 (D) is a diagram showing an example of a change characteristic of a resonance frequency with respect to the film thickness of a tungsten (W) film.

12 is a diagram showing the relationship between the film thickness and the resonant frequency in the case where the conductive film to be polished is a Cu film in the embodiment of the present invention, and FIG. Fig. 12B is a diagram showing an example of the relationship between the film thickness and the resonant frequency in the stationary state.

13 is a diagram showing a relationship between a film thickness and a resonance frequency in the embodiment of the present invention.

FIG. 14 is a diagram showing the correspondence between the film thickness change and the first derivative of the resonant frequency in the embodiment of the present invention.

FIG. 15 is a diagram showing a correspondence between a film thickness change and a second derivative of a resonance frequency in the embodiment of the present invention. FIG.

<Explanation of symbols for the main parts of the drawings>

1: chemical mechanical polishing device 2: platen

3: polishing head 4: rotating shaft

5: motor 6: polishing pad

7: head body 8: carrier

9: retainer ring 10: retainer ring pressurizing means

11: elastic sheet 12: axis of rotation

13: dry plate 14: pin

15 operation transformer 16 carrier pressurizing means

17: air float line 19: air blowing port

20: air filter 21: air supply pump

22: hole 23: vacuum pump

24: vacuum line 25: air bag

27 retainer ring holder 28 conductive film

29: air chamber 30: attachment member

31: snap ring 32: slip ring

33: Prediction and detection device at the end of polishing (real-time film thickness monitor device)

34: high frequency inductor type sensor 35: oscillation circuit

36: planar shape inductor 36a: insulating substrate

37: concentrated constant capacitor 38: amplifier

39: feedback network 40: frequency counter

41: planar shape inductor 41a: insulating substrate

P: film thickness reference point W: wafer

Claims (26)

As a prediction and detection method at the polishing end point for polishing the conductive film and predicting and detecting the polishing end point 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 change caused by the predetermined conductive film is monitored by the magnetic flux formed by the inductor, and the film thickness during polishing is the predetermined conductive film. By using the magnetic flux change that is markedly caused by the skin effect determined by the material of as a factor, the magnetic flux change part for predicting the polishing end point is detected during this magnetic flux change process, and the polishing end point is started from the magnetic flux change part. Prediction and detection method at the end of polishing, characterized by predicting. The method of claim 1, The method of detecting the magnetic flux change part by the skin effect is characterized by detecting characteristic changes peculiar to the skin effect such as peaks of peaks, inflection points, rising rates of changes, rising amounts of changes, starting points of rise, and the like. Prediction and Detection Method. The method for detecting a portion of the magnetic flux change caused by the skin effect is to detect characteristic changes peculiar to the skin effect such as waveform peak points, inflection points, and predetermined ascending point points. The method according to claim 1 or 2, A high frequency inductor type sensor in close proximity to the conductive film is a two-dimensional planar inductor. The method according to any one of claims 1 to 3, A high frequency inductor type sensor in close proximity to the conductive film has a structure in which a conductive film is attached to the surface of a substrate formed of an insulator, and the prediction and detection method at the end of polishing is performed. The method according to any one of claims 1 to 4, The monitor of the change in magnetic flux caused based on the skin effect of the predetermined conductive film includes the measurement of the eddy current in the predetermined conductive film, the measurement of the mutual inductance caused by the eddy current generated by the predetermined conductive film, and the predetermined conductivity. At least any one of the measurement of the inductance change of the sensor circuit system in the high frequency inductor type sensor by the mutual inductance of the film formation, or the change in the inductance of the sensor circuit system in the change of the resonance frequency at which the high frequency inductor sensor oscillates A prediction and detection method at the end of polishing, characterized by one. 6. An polishing finish according to claim 5, wherein an oscillator for oscillating the high frequency inductor sensor and a frequency counter for monitoring a change in its oscillation frequency are arranged in proximity to the high frequency inductor sensor. Prediction and detection method of viewpoint. The method according to claim 5 or 6, The change in magnetic flux, change in eddy current, change in mutual inductance, and change in resonant frequency caused on the basis of the skin effect of the predetermined conductive film include a change in eddy current as the penetration flux increases as the film thickness decreases. A method for predicting and detecting the end of polishing, comprising two kinds of changes in which the eddy current forming region substantially decreases with the subsequent decrease in film thickness. As a prediction and detection method at the polishing end point for polishing the conductive film and predicting and detecting the polishing end point 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 mutual inductance induced in the conductive film increases by increasing the magnetic flux passing through the conductive film to be polished as the film thickness decreases due to the polishing process. By selecting the shape and the frequency band, by monitoring the magnetic flux change induced in the predetermined conductive film by the magnetic flux formed by the inductor, by using the magnetic flux change in which the film thickness during polishing is marked by the skin effect, A method of predicting and detecting a polishing end point, characterized by detecting a change in magnetic flux for predicting the end point of polishing during the flux change process and predicting the end point of polishing from the change in magnetic flux. The method of claim 8, The said frequency band selected is 20 MHz or more when the material of the said predetermined | prescribed electroconductive film is Cu, The prediction and detection method of the completion | finish time of grinding | polishing characterized by the above-mentioned. A method of predicting and detecting a polishing end point for polishing a conductive film and predicting and detecting a polishing end point when a predetermined conductive film is properly removed, wherein the inductor in the high frequency inductor sensor is close to the predetermined conductive film. In the initial stage of polishing, at least part of the magnetic flux formed by the inductor oscillates from the high frequency inductor type sensor at a frequency that does not penetrate the predetermined conductive film due to the skin effect of the predetermined conductive film. At least once in a process of increasing at least a portion of the magnetic flux penetrating the conductive film in accordance with the progress, the change in the leakage magnetic flux that penetrates the predetermined conductive film during polishing during the polishing of the magnetic flux formed by the inductor, Film thickness of leakage magnetic flux markedly by the skin effect The change is used to detect the leakage magnetic flux change portion for predicting the polishing completion point during the leakage magnetic flux change process, and to predict the polishing completion time from the leakage magnetic flux change portion. Way. As a prediction and detection method at the polishing end point for polishing the conductive film and predicting and detecting the polishing end point when the predetermined conductive film is properly removed, The inductor of the high frequency inductor type sensor is brought close to the predetermined conductive film, and at least part of the magnetic fluxes formed by the inductor in the initial polishing stage do not penetrate the predetermined conductive film due to the skin effect of the predetermined conductive film. An inductor shape that generates a magnetic field with no directivity 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 magnetic flux penetrating the predetermined conductive film as the polishing proceeds. At least once in a process of increasing, the change of the leakage magnetic flux which penetrates the predetermined conductive film during the polishing of the magnetic flux formed by the inductor is monitored as the change of the eddy current which the leakage magnetic flux makes, and the film thickness during polishing is During the process of changing the eddy current, which is marked by the skin effect In detecting the eddy current change portion for predicting the polishing end point, and predicting, detecting method of polishing the end, characterized in that predicting the polishing end point from the change of this eddy current. The method according to any one of claims 1 to 11, Regarding a method for predicting the end point of polishing from the waveform change portion caused by the skin effect, the end of polishing is performed after polishing for a predetermined polishing time from the waveform change portion, and then the prediction and detection of the end point of polishing is performed. Way. The method of claim 12, wherein the waveform change portion is a change peculiar to the skin effect of a peak, an inflection point, an increase rate of change, an increase change amount, and an increase start point of a peak. The method according to any one of claims 1 to 13, Regarding the predictive detection method from the waveform change portion due to the skin effect to the end point of polishing, the polishing rate is calculated from the time of reaching the waveform change portion and the amount of polishing from the waveform change portion to the polishing change amount. By dividing the film thickness calculated from the change in the waveform as the characteristic by the polishing rate, the remaining polishing time required from the waveform change portion to the end of polishing is calculated, and the time polishing calculated from the waveform change point is calculated. After that, it is set as the end point of polishing, The prediction and detection method at the end of polishing. As a prediction and detection method at the polishing end point for polishing the conductive film and predicting and detecting the polishing end point when the predetermined conductive film is properly removed, The inductor of the high frequency inductor type sensor is brought close to the predetermined conductive film, and at least part of the magnetic fluxes formed by the inductor in the initial polishing stage do not penetrate the predetermined conductive film due to the skin effect of the predetermined conductive film. An inductor shape that generates a magnetic field without an undirected degree 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 magnetic flux penetrating the at least part of the conductive film as the polishing proceeds. This increasing process is performed at least once, and the change of the eddy current caused by the change of the leakage magnetic flux that penetrates the predetermined conductive film during the polishing of the magnetic flux formed by the inductor is used for the mutual inductance generated in the inductor by the eddy current. Monitored as a change, the film thickness during polishing is Detecting the change in the mutual inductance for predicting the polishing end point based on the change in the mutual inductance when the skin depth is equal to or near the skin depth according to the skin effect, and predicting the polishing end point from the change portion A method of predicting and detecting a polishing completion point characterized by the above-mentioned. As a prediction and detection method at the polishing end point for polishing the conductive film and predicting and detecting the polishing end point when the predetermined conductive film is properly removed, The inductor of the high frequency inductor type sensor is brought close to the predetermined conductive film, and at least part of the magnetic fluxes formed by the inductor in the initial polishing stage do not penetrate the predetermined conductive film due to the skin effect of the predetermined conductive film. An inductor shape that generates a magnetic field with no directivity 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 magnetic flux penetrating the at least part of the conductive film as the polishing proceeds. Change in inductance of the sensor circuit system in the high frequency inductor type sensor having this increasing process at least once and based on a change in the leakage magnetic flux passing through the predetermined conductive film during the polishing of the magnetic flux formed by the inductor. This inductance and the intrinsic capacitance of the sensor circuit It monitors as a change in the determined resonant frequency, and detects the change portion of the resonant frequency for predicting the end point of polishing based on the change in the resonant frequency when the film thickness during polishing becomes the film thickness corresponding to the skin effect. And predicting the end point of polishing from this change portion. As a prediction and detection method at the polishing end point for polishing the conductive film and predicting and detecting the polishing end point when the predetermined conductive film is properly removed, The inductor of the high frequency inductor type sensor is brought close to the predetermined conductive film, and at least part of the magnetic fluxes formed by the inductor in the initial polishing stage do not penetrate the predetermined conductive film due to the skin effect of the predetermined conductive film. An inductor shape that generates a magnetic field with no directivity 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 magnetic flux penetrating the at least part of the conductive film as the polishing proceeds. At least once of this increasing process, a change in the eddy current caused by a change in the leakage magnetic flux that penetrates the predetermined conductive film during the polishing of the magnetic flux formed by the inductor, and the mutual generated in the inductor due to the change in the eddy current The change in inductance or this mutual inductance change The change of the resonance 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 is monitored, and the film thickness during polishing is applied to the skin effect. A change portion of the resonance frequency for predicting the end point of polishing based on at least one change of each change in the case of a corresponding film thickness is detected, and the end point of polishing polishing is predicted from this change portion. Prediction and detection method at the end of polishing. 18. The film corresponding to the skin depth according to claim 17, wherein 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. There are two phenomena, namely, the increase of the eddy current caused by the increase of the leakage magnetic flux caused by the thickness and the decrease of the eddy current forming region due to the decrease of the film thickness volume caused by polishing, resulting in the maximum point (peak). The said change part is detected by the prediction and detection method of the completion | finish point of grinding | polishing. A real-time film thickness monitoring method for polishing a conductive film and monitoring a film thickness change during polishing to evaluate whether a predetermined conductive film is properly removed, The inductor of the high frequency inductor type sensor is brought close to the predetermined conductive film, and at least part of the magnetic fluxes formed by the inductor in the initial polishing stage do not penetrate the predetermined conductive film due to the skin effect of the predetermined conductive film. At least one of the processes of oscillating the frequency from the high frequency inductor type sensor and increasing the magnetic flux passing through the at least part of the conductive film as the polishing progresses, and the progress of polishing among the magnetic fluxes formed by the inductor The change of the leakage magnetic flux for monitoring the change of the leakage magnetic flux which penetrates the said predetermined conductive film in the middle, and for predicting a grinding | polishing end time from the change of the said leakage magnetic flux when the film thickness during grinding | polishing becomes the film thickness corresponding to the said skin effect. Detect part and polish in place on the basis of this change part And the balance film thickness monitor real-time manner, characterized in that for calculating the amount of the thickness to be removed. A real-time film thickness monitoring method for polishing a conductive film and monitoring a film thickness change during polishing to evaluate whether a predetermined conductive film is properly removed, The inductor of the high frequency inductor type sensor is brought close to the predetermined conductive film, and at least part of the magnetic fluxes formed by the inductor in the initial polishing stage do not penetrate the predetermined conductive film due to the skin effect of the predetermined conductive film. At least one of the processes of oscillating the frequency from the high frequency inductor type sensor and increasing the magnetic flux passing through the at least part of the conductive film as the polishing progresses, and the progress of polishing among the magnetic fluxes formed by the inductor The change of the leakage magnetic flux which penetrates the said predetermined conductive film during this time is monitored as the change of the eddy current which this leakage magnetic flux produces, and the grinding | polishing end time is started from the change of the said eddy current when the film thickness during grinding | polishing becomes the film thickness corresponding to the said skin effect. Detect the change in leakage flux to predict A method for real-time film thickness monitoring, comprising calculating the polishing rate and the remaining amount of film thickness to be removed on the basis of the portion. A real-time film thickness monitoring method for polishing a conductive film and monitoring a film thickness change during polishing to evaluate whether a predetermined conductive film is properly removed, The inductor of the high frequency inductor type sensor is brought close to the predetermined conductive film, and at least part of the magnetic fluxes formed by the inductor in the initial polishing stage do not penetrate the predetermined conductive film due to the skin effect of the predetermined conductive film. At least one of the processes of oscillating the frequency from the high frequency inductor type sensor and increasing the magnetic flux passing through the at least part of the conductive film as the polishing progresses, and the progress of polishing among the magnetic fluxes formed by the inductor The change in the eddy current caused by the change in the leakage magnetic flux that penetrates the predetermined conductive film is monitored as the change in mutual inductance generated in the inductor by this eddy current, and the film thickness during polishing becomes the film thickness corresponding to the skin effect. From the change of mutual inductance in the case Detects the change in the mutual inductance to predict, and detects the change in the mutual inductance to predict the polishing end point from this change, and the polishing rate and the remaining film thickness to be removed on the basis of this change. Real-time film thickness monitoring method characterized by calculating the amount. A real-time film thickness monitoring method for polishing a conductive film and monitoring a film thickness change during polishing to evaluate whether a predetermined conductive film is properly removed, The inductor of the high frequency inductor type sensor is brought close to the predetermined conductive film, and at least part of the magnetic fluxes formed by the inductor in the initial polishing stage do not penetrate the predetermined conductive film due to the skin effect of the predetermined conductive film. At least one of the processes of oscillating the frequency from the high frequency inductor type sensor and increasing the magnetic flux passing through the at least part of the conductive film as the polishing progresses, and the progress of polishing among the magnetic fluxes formed by the inductor The change in inductance of the sensor circuit system in the high frequency inductor type sensor based on the change of the leakage magnetic flux passing through the predetermined conductive film is monitored as the change in the resonance frequency determined by the inductance and the intrinsic capacitance of the sensor circuit system. And the film thickness during polishing corresponds to the skin effect From the change in the resonant frequency when the film thickness is reached, the change portion of the resonant frequency for predicting the end point of polishing is detected, and the polishing rate and the remaining amount of film thickness to be removed are calculated on the basis of the change portion. The real-time film thickness monitoring method characterized by the above-mentioned. The method according to any one of claims 20 to 22, 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 equal to or close to the skin depth, due to the skin effect, The peak occurs due to the action of two phenomena, the increase of the eddy current and the decrease of the eddy current due to the decrease of the film thickness volume by polishing, and based on the peak, a change portion for predicting the end point of polishing is detected. Time film thickness monitor method. Polishing end having a high frequency inductor type sensor having an oscillation circuit constituting a sensor circuit system comprising a planar inductor and a capacitor, and polishing the conductive film to predict and detect the polishing end point when the predetermined conductive film is properly removed. As a prediction and detection device of a viewpoint, A prediction and detection apparatus at the polishing end point is executed, wherein the prediction and detection method at the polishing end point according to any one of claims 1 to 18 is executed. A high frequency inductor type sensor having an oscillation circuit constituting a sensor circuit system consisting of a planar inductor and a capacitor, the conductive film is polished to change the film thickness during polishing to evaluate whether a predetermined conductive film is properly removed. As a real-time film thickness monitor device to monitor, A real-time film thickness monitoring apparatus comprising the real-time film thickness monitoring method according to any one of claims 19 to 23.

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