JPH08240413A - Film thickness measuring device and polishing device - Google Patents

Abstract

PURPOSE: To measure the film thickness formed on a substrate by means of on-machine on a polishing device with high accuracy, to accurately control the film thickness by means of polishing working for enhancing the throughput of the polishing device, and to eliminate the cost loss due to waste wafers. CONSTITUTION: A measuring body terminal 31 is arranged above a semiconductor wafer 1, and white light is thrown on the semiconductor wafer 1 through projecting/receiving optical systems 34, 35 in the measuring body terminal 31, and the interference fringes produced by the reflected light from the semiconductor wafer 1 are detected for measuring the film thickness of the insulation film of the semiconductor wafer 1 by means of an interference spectral film- thickness measuring device 325, and the hours of polishing working are controlled on the basis of this measured value of the film thickness.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film thickness measuring device for measuring the film thickness of an insulating film formed by flattening on the surface of a semiconductor wafer, and an optimum film thickness by managing the measured value of this film thickness. The present invention relates to a polishing device for polishing.

[0002]

2. Description of the Related Art Semiconductor manufacturing processes include a flattening process for flattening unevenness of a thin film on the surface of a silicon substrate.
A polishing device is used for this flattening. FIG.
8 is a process diagram of such a flattening process. In the semiconductor wafer 1, a metal pattern 3 made of an insulating film 4'and Al is formed on a silicon substrate 2 as shown in FIG.

Next, SiO 2 is formed on the silicon substrate 2.
An insulating film 4 such as ₂ is formed. This insulating film 4 is
As shown in (b), the surface is formed to be uneven by film formation.

Next, the insulating film 4 is subjected to polishing processing, whereby the surface of the insulating film 4 is flattened and formed into a predetermined film thickness as shown in FIG. .
Here, the polishing apparatus applied to the polishing process is provided with a lower rotary table 5 as shown in FIG. 19, and a cloth 6 is provided on the table.

An upper rotary table 7 is provided facing the lower rotary table 5. The upper rotary table 7 vacuum-sucks the semiconductor wafer 1 on the lower part thereof and presses it against the cloth 6 on the lower rotary table 5.

Further, an abrasive nozzle 8 is arranged above the lower rotary table 5. With such a configuration, the semiconductor wafer 1 is vacuum-sucked to the lower portion of the upper rotary table 7 and pressed against the cloth 6 on the lower rotary table 5.

In this state, the lower rotary table 5 and the upper rotary table 7 are opposite to each other, that is, the lower rotary table 5 rotates in the arrow A direction and the upper rotary table 7 rotates in the arrow B direction.

At the same time, the abrasive S is supplied from the abrasive nozzle 8 onto the cloth 6. In this way, the insulating film 4 of the semiconductor wafer 1 is rotated by the rotation of the rotary tables 5 and 7,
It is gradually thinned.

As the semiconductor wafer 1, as shown in FIG. 20, an insulating film 4'and a SiO ₂ film are formed on a silicon substrate _2.
There is one in which an insulating film pattern 4a of Al, etc. is formed and a metal film 3a of Al or the like is formed on the insulating film pattern 4a, and for such a semiconductor wafer 1, the metal film 3a is subjected to polishing processing.

By the way, such polishing processing is
Prior to the original polishing process, a test semiconductor wafer (test wafer) is flown, the test wafer is polished, the test wafer is taken out from the polishing device, and the film thickness is measured by batch processing to obtain a predetermined film thickness. The processing time for polishing is set by confirming that

Thereafter, by operating the polishing apparatus according to the set polishing time, the insulating film 4 of the semiconductor wafer 1 is flattened to a predetermined thickness as shown in FIG. 18 (c), for example. The insulating film 4 is flattened to the same thickness as the metal pattern 3 as shown in FIG. 21, for example. Further, in the semiconductor wafer 1 shown in FIG. 20, the metal film 3a is flattened to a predetermined thickness.

[0012]

However, since the polishing process is ended by the time management of the polishing process time set by the test, if the polishing speed fluctuates due to the deterioration of the quality of the cloth 6 or the life of the cloth 6, the flattening process becomes excessive or insufficient. Occurs, and the insulating film 4 cannot be formed to have a predetermined film thickness.

Further, due to the excess or deficiency of the flattening process, a defect occurs due to the depression of the metal pattern 3, the remaining metal pattern 3 on the insulating film 4, and the like. Further, since it is necessary to flow the test wafer, the cost loss due to the test wafer is great.

Moreover, since it is necessary to perform a batch process in which a step for measuring the film thickness is newly provided, the throughput of the polishing apparatus is lowered. Therefore, an object of the present invention is to provide a film thickness measuring device capable of accurately measuring the film thickness formed on a substrate.

Another object of the present invention is to provide a film thickness measuring device capable of accurately measuring the film thickness formed on a substrate on-machine on a polishing device. The present invention also provides
Polishing that can measure the film thickness formed on the substrate with high accuracy on-machine on the polishing device and control the film thickness by polishing process with high accuracy to improve the throughput of the polishing device and eliminate the cost loss due to the test wafer. The purpose is to provide a device.

Another object of the present invention is to provide a polishing apparatus capable of accurately determining that a film having a predetermined thickness is formed when polishing the film. or,
An object of the present invention is to provide a polishing apparatus capable of accurately determining the processing end point when polishing processing is performed on a film and forming the film to a predetermined film thickness.

[0017]

According to a first aspect of the present invention, a substrate having a light-transmitting film formed on its surface is irradiated with light.
In the film thickness measuring device that measures the film thickness by detecting the interference fringes generated by the reflected light from the substrate, at least the light projecting / receiving optical system that irradiates the substrate from above and receives the reflected light from the substrate is incorporated. The film thickness measuring device is provided with a measuring main body terminal provided in the.

In such a film thickness measuring apparatus, the measuring main body terminal is arranged above the substrate, light is irradiated onto the substrate through the light projecting / receiving optical system in the measuring main body terminal, and the interference caused by the reflected light from the substrate is caused. Detect stripes. Then, the film thickness is measured based on the interference fringes.

According to a second aspect of the present invention, in the polishing apparatus according to the first aspect, the measurement main body terminal includes a light projecting / receiving optical system for irradiating the substrate with light and receiving reflected light from the substrate. A positioning table for moving the light projecting / receiving optical system in the XYθ directions and an image pickup device for picking up an image reflected through the light projecting / receiving optical system were provided, and an observation window was provided in a container facing the light projecting / receiving optical system.

In such a film thickness measuring device, an image taken through the light projecting / receiving optical system is imaged by the imaging device in the measuring main body terminal, and the image is observed and the projecting / receiving optical system is moved in the XYθ directions by the positioning table. Position with respect to the substrate. Then, at this position, the light is projected onto the substrate through the observation window through the projection / reception optical system,
The interference fringes generated by the reflected light from this substrate are detected.

According to a third aspect of the present invention, there is provided a measuring main body terminal for detecting an interference fringe generated by reflected light from a substrate having a light-transmitting film formed on its surface when the substrate is irradiated with light at least from above. The measuring main body terminal is provided with a measuring means for obtaining the film thickness based on the interference fringes detected by the measuring main body terminal, and the measuring main body terminal irradiates the substrate with light and receives the reflected light from the substrate. System, a positioning table for moving the projection / reception optical system in the XYθ directions, and an image pickup device for picking up an image projected through the projection / reception optical system,
In addition, an observation window is provided in the container at the portion facing by the light projecting and receiving optical system, the measuring means obtains a difference from the reference coordinates of the substrate based on the image data of the substrate imaged by the image pickup device, and the positioning table is determined based on this difference. A film thickness measuring device having a driving positioning means and a film thickness meter for obtaining a film thickness from an interference fringe detected by a measuring main body terminal.

In such a film thickness measuring apparatus, the measuring main body terminal is arranged above the substrate, an image projected through the light projecting and receiving optical system in the measuring main body terminal is imaged by the image pickup device, and the substrate is measured based on the image data. The difference with respect to the reference coordinates is obtained, and based on this difference, the projection / reception optical system is moved in the XYθ directions by the positioning table to perform positioning with respect to the substrate. Then, at this position, the light is projected onto the substrate through the observation window through the observation window, the interference fringes generated by the reflected light from the substrate are detected, and the film thickness is obtained by the film thickness meter.

According to a fourth aspect, in the film thickness measuring apparatus according to the second or third aspect, the measurement main body terminal is hermetically sealed. In such a film thickness measuring device, the measuring main body terminal is hermetically sealed and provided with a light emitting / receiving optical system and the like inside thereof.

According to a fifth aspect, in the film thickness measuring apparatus according to the second or third aspect, the observation window is provided so as to be inclined with respect to the optical axis of the irradiation light from the light projecting and receiving optical system. In such a film thickness measuring device, the observation window can be provided so as to be inclined with respect to the optical axis of the irradiation light from the light projecting and receiving optical system, and flare (stray light) can be prevented.

According to the sixth aspect of the present invention, the translucent film formed on the substrate is subjected to polishing processing to flatten the film, after which the substrate is irradiated with light and reflected from the substrate. In a polishing device for measuring interference fringes caused by light to measure a film thickness, it is configured by a container having a light projecting / receiving optical system inside which irradiates at least light onto a substrate from above and receives reflected light from the substrate. The polishing apparatus includes a measurement main body terminal and polishing control means for controlling the polishing processing time based on the measured value of the film thickness.

In such a polishing apparatus, the measurement main body terminal is arranged above the substrate, light is irradiated onto the substrate through the light projecting and receiving optical system in the measurement main body terminal, and the interference fringes generated by the reflected light from the substrate are generated. The film thickness is detected and the film thickness is measured, and the polishing time is controlled based on the measured value of the film thickness.

According to the present invention, the light-transmitting film formed on the substrate is polished to flatten the film, and then the substrate is irradiated with light and reflected from the substrate. In a polishing device for measuring interference fringes generated by light to measure a film thickness, a measurement main body terminal for detecting interference fringes generated by reflected light from at least a substrate when light is irradiated onto the substrate from above, and a measurement main body. The measuring main body terminal is provided with a measuring means for obtaining the film thickness based on the interference fringes detected by the terminal, and the measuring main body terminal irradiates light onto the substrate and receives the reflected light from the substrate, A positioning table for moving the light emitting / receiving optical system in the XYθ directions, and an image pickup device for picking up an image reflected through the light emitting / receiving optical system are provided, and an observation window is provided in a container at a portion facing the light emitting / receiving optical system for measurement The stage obtains a difference from the reference coordinates of the substrate on the basis of the image data of the substrate taken by the image pickup device, and based on this difference, the positioning means for driving the positioning table and the film from the interference fringes detected by the measuring main body terminal. A polishing apparatus having a film thickness meter for obtaining a thickness and a polishing control means for controlling a polishing processing time based on a measured value of the film thickness obtained by the film thickness meter.

In such a polishing apparatus, the measurement main body terminal is arranged above the substrate, and the image projected through the projection / reception optical system of the measurement main body terminal is imaged by the image pickup device,
The difference from the reference coordinates of the substrate is obtained based on the image data, and based on this difference, the projection / reception optical system is moved in the XYθ directions by the positioning table to position the substrate. Then, at this position, the light is projected onto the substrate through the observation window through the observation window, the interference fringes generated by the reflected light from the substrate are detected, and the film thickness is obtained by the film thickness meter. The polishing processing time is controlled based on the measured value.

According to the eighth aspect, the substrate on which the film is formed is sandwiched between the first rotary table and the second rotary table, and at least one of the first rotary table and the second rotary table is rotated. In a polishing device for polishing a film with a film, an electrode provided on the lower rotary table side of the first or second rotary table and in contact with the film, and a capacitance formed between the electrode and the film are detected. And a polishing control means for controlling the polishing processing time for the film based on the change in the electrostatic capacitance detected by the electrostatic capacitance detection means.

In such a polishing apparatus, the electrostatic capacitance formed between the electrode and the film provided on either the first or second rotary table is detected, and the change in the electrostatic capacitance is detected. Based on this, the polishing time for the film is controlled.

According to a ninth aspect, in the polishing apparatus according to the eighth aspect, the electrode is provided between the metal plate embedded in either one of the first and second rotary tables and the metal plate and the film. Is located in.

In such a polishing apparatus, the capacitance between the films is detected from the metal plate through the dielectric, and the time for polishing the film is controlled based on the change in the capacitance.

According to a tenth aspect, in the polishing apparatus according to the eighth aspect, the polishing control means polishes the film when the electrostatic capacitance formed between the electrode and the film suddenly changes from a predetermined range. Determined as the end point of machining.

In such a polishing apparatus, the electrostatic capacitance formed between the electrode and the film provided on either the first or second rotary table is detected during the polishing process for the film, The sudden change in the capacitance is determined as the end point of the polishing process for the film, and the polishing process is completed.

According to the eleventh aspect, the substrate on which the film is formed is sandwiched between the first rotary table and the second rotary table, and at least one of the first rotary table and the second rotary table is rotated. In a polishing apparatus for polishing a film, a sound detecting unit which is provided on either one of the first and second rotary tables and detects a sound generated during the polishing process on the film, and a sound detecting unit which detects the sound. And a polishing control means for controlling a polishing processing time for the film based on a change in sound.

In such a polishing apparatus, the sound generated during the polishing process for the film is detected, and the polishing process time for the film is controlled based on the change in the sound.

According to a twelfth aspect, in the polishing apparatus according to the eleventh aspect, the sound detecting means is generated during the polishing process when the film crosses in synchronization with the rotation of the first or second rotary table. Capture the sound you make.

In such a polishing apparatus, the sound generated during the polishing process for the film is taken in when the film crosses and the S / N is improved. According to the thirteenth aspect, in the polishing apparatus according to the eleventh aspect, the polishing control means determines as the end point of the polishing process for the film when the change in the sound generated during the polishing process becomes constant.

In such a polishing apparatus, the sound generated during the polishing process for the film is detected during the polishing process for the film, and when the rate of change of the sound becomes constant, it is determined as the end point of the polishing process for the film. Then, the polishing process is completed.

[0040]

BEST MODE FOR CARRYING OUT THE INVENTION

(1) Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. The same parts as those in FIGS. 18 and 19 are designated by the same reference numerals. FIG. 1 is an overall configuration diagram of a polishing device to which a film thickness measuring device is applied.

This polishing apparatus is roughly divided into a polishing main body apparatus 10, a wafer transfer apparatus 20, and a thin film measuring apparatus 30. Polishing main unit 1
In No. 0, the lower rotary table (first rotary table) 5 is provided with a cross 6, and the upper rotary table (second rotary table) 7 is provided so as to face the lower rotary table 5.

The upper rotary table 7 vacuum-sucks the semiconductor wafer 1 on its lower portion and presses it against the cloth 6 on the lower rotary table 5. Also, the lower rotary table 5
A polishing agent nozzle 8 is disposed above.

Drive sources 11 and 12 are connected to the lower rotary table 5 and the upper rotary table 7, respectively, and the drive sources 11 and 12 are drive-controlled by a polishing controller 13.

The wafer transfer device 20 has a function of receiving the semiconductor wafer 1 from the polishing main body device 10, mounting the semiconductor wafer 10 on the stage 21, transporting it to the thin film measuring device 30, delivering it, and setting it at a predetermined position. Have

The thin film measuring device 30 irradiates the semiconductor wafer 1 with light, for example, white light, detects interference fringes generated by the reflected light from the semiconductor wafer 1, and detects the insulating film formed on the semiconductor wafer 1. 4 has a function of measuring the film thickness, and is composed of a measurement main body terminal 31 and an electrical equipment section 32.

FIG. 2 is a concrete configuration diagram of the measuring main body terminal 31 and the measuring section 32. The measurement main body terminal 31 has a sealed container, that is, a box 33, and a positioning table 34, left and right projection / reception optical systems 35 and 36, and television cameras (hereinafter referred to as image pickup devices) in the box 33. , And TV cameras), and an observation window 39 is provided in a portion of the box 33 desired by each of the left and right projection / reception optical systems 35 and 36.

The observation window 39 is made of a translucent material, and the left and right projection / reception optical systems 35, 36 are provided.
Are provided so as to be inclined with respect to the optical axis of each light emitted from the.

FIG. 3 schematically shows the internal structure of the measuring main body terminal 31. The positioning table 34 is integrally provided in the order of the θ table 300, the X table 301, and the Y table 302 from above.

The left and right projection / reception optical systems 35 and 36 are provided on the lower surface of the Y table 302.
The left projection / reception optical system 35 is provided with the TV camera 37 at the end side of the lens barrel 303, and the first beam splitter 304, the lens 305, the second beam splitter 306, and the lens 307 from the end side in the lens barrel 303. , And the mirror 30
8 are arranged.

Further, a light receiving fiber 309 is connected in the branch direction of the first beam splitter 304 in the lens barrel 303, and a projecting optical fiber 310 is connected in the branch direction of the second beam splitter 306. A lens 311 is arranged in the projection optical fiber 310.

In the right side projection / reception optical system 36, the TV camera 38 is provided at the end side of the lens barrel 312, and the lens 313 and the third beam splitter 31 are arranged from the end side in the lens barrel 312.
4, a lens 315, and a mirror 316 are arranged.

A projection optical fiber 317 is connected to the lens barrel 312 in the direction of branching of the third beam splitter 314. A lens 318 is arranged in the projection optical fiber 317.

On the other hand, the measuring section 32 is provided with an XYθ table driver 320 and first and second camera control units 321 and 322. The first and second camera control units 321 and 322 control the operations of the TV cameras 37 and 38 of the light projecting and receiving optical systems 34 and 35, respectively, and perform image positioning of the image signals output from the TV cameras 37 and 38. It has a function of sending to the device 323.

This image positioning device 323 is shown in FIG.
As shown in (b), the reference pattern formed on the semiconductor wafer 1, for example, the values at which the center positions of the cross mark P1 and the square mark P2 come to the center position of the screen are stored in advance as the coordinates of the reference position.

The image positioning device 323 obtains the coordinates of the reference pattern in the image signals from the TV cameras 37 and 38 by a pattern matching method, and eliminates the difference between the coordinates and the coordinates of the reference position stored in advance. Is sent to the XYθ table driver 320.

The XYθ table driver 320 has a function of driving the X table 300, the Y table 301 and the θ table 302 in accordance with a control signal from the image positioning device 323.

As the light source 324, for example, a halogen lamp is used, and the light projecting optical fibers 310 and 317 of the left and right light projecting / receiving optical systems 35 and 36 are connected to the light source 324.

The interference spectroscopic film thickness meter 325 is connected to the light receiving fiber 309, detects the peak position of the interference fringes received through the light receiving fiber 309, and calculates the following equation based on these peak intervals to calculate the insulating film 4 It has a function of obtaining the film thickness d.

[0059]

[Equation 1]

Here, λ _m is the wavelength that gives one maximum (or minimum) reflectance in the waveform of the interference light, and λ _ml
Is a wavelength that gives the l-th reflectance maximum (or minimum) in the increasing wavelength direction. Further, n is the refractive index of the insulating film 4, and φ is the incident angle of white light.

The arithmetic and control unit 326 is the interference spectroscopic film thickness meter 3
25, the measured value of the film thickness obtained by 25 is set, the polishing time is set based on the difference between the measured value of the film thickness and the designed value of the film thickness, and the control signal corresponding to this polishing time is sent to the polishing main body device 10. It has a function of sending to the policing control unit 13.

The arithmetic and control unit 326 also controls the XYθ table driver 320 via the image positioning unit 323.
And has a function of positioning at a film thickness measurement point on the semiconductor wafer 1.

Next, the operation of the apparatus configured as described above will be described. The polishing main body device 10 polishes the semiconductor wafer 1 to flatten the insulating film 4.

After that, the wafer transfer device 20 receives the semiconductor wafer 1 from the polishing main body device 10, mounts the semiconductor wafer 10 on the stage 21, and then the thin film measuring device 3
It is conveyed to 0 and set at a predetermined position of the thin film measurement device 30, that is, below the measurement main body terminal 31. In this case, the semiconductor wafer 1 is set with the insulating film 4 facing upward.

When the light source 324 of the thin film measuring apparatus 30 is turned on, the white light emitted from the light source 324 is sent to the left and right light projecting / receiving optical systems 35, 36 through the respective projecting optical fibers 310, 317.

Of these, in the left projection / reception optical system 35,
The white light is transmitted through the lens 311 and the second beam splitter 30.
6, emitted through the lens 307 and the mirror 308,
Further, the surface of the semiconductor wafer 1 is irradiated through the observation window 39.

The reflected light from the surface of the semiconductor wafer 1 passes through the observation window 39, and further the mirror 308 and the lens 3
07, the second beam splitter 306, the lens 305,
The TV camera 37 through the first beam splitter 304.
Incident on.

The TV camera 37 captures the incident surface image of the semiconductor wafer 1 and outputs the image signal.
Further, in the right side light projecting / receiving optical system 36, the white light is reflected by the lens 318, the second beam splitter 314, the lens 315.
And the observation window 39.
The surface of the semiconductor wafer 1 is irradiated therethrough.

The reflected light from the surface of the semiconductor wafer 1 passes through the observation window 39, and further the mirror 316 and the lens 3.
The light enters the TV camera 38 through 15, the second beam splitter 314, and the lens 313.

The TV camera 38 picks up the incident surface image of the semiconductor wafer 1 and outputs the image signal. The image signals output from the TV cameras 37 and 38 are sent to the image positioning device 323 through the camera control units 321 and 322.

Here, in the image data picked up by the left TV camera 37, the cross mark P1 is located at the upper right of the screen center, as shown in FIG. 5 (a). In the image data taken by the TV camera 38 on the right side, a square mark P2 is located on the upper right side from the center of the screen as shown in FIG.

The image positioning device 323 obtains the position coordinates of the cross mark P1 and the square mark P2 imaged by the TV cameras 37 and 38 by pattern matching, and stores them in advance as the position coordinates of the cross mark P1 and the square mark P2. The coordinates of the reference positions of the cross mark P1 and the square mark P2 are compared, and a control signal for eliminating the difference between these coordinates is sent to the XYθ table driver 320.

The XYθ table driver 320 drives the X table 300, the Y table 301, and the θ table 302 respectively in accordance with the control signal from the image positioning device 323, so that the cross mark P1 and the square mark P2 coincide with the reference position. Let

After that, the arithmetic and control unit 326 causes the XYθ table driver 320 via the image positioning unit 323.
Is controlled to position at the film thickness measurement point on the semiconductor wafer 1.

As a result, the white light emitted from the light source 324 is transmitted to the lens 311 in the left projection / reception optical system 35.
The light is emitted through the second beam splitter 306, the lens 307, and the mirror 308, and is further irradiated through the observation window 39 to the film thickness measurement point on the surface of the semiconductor wafer 1.

The white light applied to the surface of the semiconductor wafer 1 is reflected by the surface of the insulating film 4 and the interface between the insulating film 4 and the metal pattern 3 as shown in FIG. Causes interference. This interference light exhibits an interference spectrum as shown in FIG.

The interference light passes through the observation window 39, and further, the mirror 308, the lens 307, and the lens 307 of the left projection / reception optical system 35.
The light receiving fiber 309 passes through the second beam splitter 306, the lens 305, and the first beam splitter 304.
To the interference spectroscopic film thickness meter 325.

The interference spectral film thickness meter 325 detects the peak position of the interference fringes and calculates the above equation (1) to obtain the film thickness d of the insulating film 4. Next, the arithmetic and control unit 326 controls the XYθ table driver 320 via the image positioning unit 323 to position at the next film thickness measurement point. As a result, the white light emitted from the light source 324 is applied to the next film thickness measurement point through the left light projecting / receiving optical system 35,
The interference light at this film thickness measurement point enters the interference spectral film thickness meter 325.

The interference spectroscopic film thickness meter 325 detects the peak positions of the interference fringes in the same manner as above, and obtains the film thickness d of the insulating film 4 from the interval between these peak positions. Thereafter, the film thickness measurement at each predetermined film thickness measurement point is repeated.

The arithmetic and control unit 326 is the interference spectroscopic film thickness meter 3
25, each measured value of the film thickness obtained by 25 is set, the polishing time is set based on the difference between the measured value of the film thickness and the design value of the film thickness, and the control signal corresponding to this polishing time is used as the polishing main body device 10. Is sent to the policing controller 13.

The polishing controller 13 drives the drive sources 11 and 12 of the lower rotary table 5 and the upper rotary table 7 in accordance with the changed and set polishing time to perform the polishing process on the semiconductor wafer 1.

As described above, in the first embodiment, each of the light projecting / receiving optical systems 35 and 3 in the measurement main body terminal 31 is used.
Since the semiconductor wafer 1 is irradiated with white light through 6 and the interference fringes generated by the reflected light from the semiconductor wafer 1 are detected to measure the film thickness d, the on-machine of the polishing apparatus can accurately measure the insulating film 4. The film thickness d can be measured.

In addition, the measurement main body terminal 31 is a box 3
Since the light emitting / receiving optical systems 35, 36, etc. are provided in 3,
The on-machine of the polishing device can easily detect the interference fringes and send them to the measurement unit 32 without taking up space.

Further, since the measuring main body terminal 31 positions each of the light projecting / receiving optical systems 35 and 36 by the positioning table 34, even if the reference position of the semiconductor wafer 1 is deviated, the position is easily corrected, and then each film is moved. Can be positioned at the thickness measurement point.

Further, since the measuring main body terminal 31 uses the sealed and sealed box 33, it is possible to detect not only in the air but also in the water, for example. Further, since the measurement main body terminal uses the sealed and sealed box 33,
The semiconductor wafer 1 is not contaminated without generating dust inside the box 33.

Further, the observation window 39 of the measurement main body terminal 31 is
Since it is provided so as to be inclined with respect to the optical axis of the white light emitted from each of the light projecting / receiving optical systems 35 and 36, flare (stray light) can be prevented.

Furthermore, since the polishing process time is controlled based on the measured value of the film thickness d of the insulating film 4, the film thickness of the insulating film 4 can be controlled with high accuracy while the polishing process is online. Throughput can be improved and cost loss of the test wafer can be eliminated.

The first embodiment may be modified as follows. For example, the film thickness meter is not limited to the interference spectral film thickness meter, and may be a film thickness meter such as an ellipsometer.

The image positioning device 323 is not limited to the pattern matching method, and may be adjusted to the reference coordinates by using another method such as a gravity center calculation for obtaining the reference position of the pattern. The film thickness d is calculated by curve fitting or FFT (Fast Fourier Tracing) for obtaining the film thickness d by comparing the theoretical waveform due to interference and the measured waveform, regardless of the peak interval of the interference fringes.
nsform) and the like, for example, a method of separating the high frequency region and the low frequency region of the measurement waveform.

The positioning table 33 may be a biaxial table. Also, the light projecting / receiving optical system 36 may be omitted,
The positioning table 34 may be a biaxial XY table.
In this case, the reference position of the pattern of the specific reference coordinate position on the wafer 1 is obtained, the differences X1 and Y1 from the reference coordinates are calculated, and the projection / reception optical system 35 is moved to the second position on the wafer 1 by the positioning table 34. Position at a specific reference coordinate position,
The reference position of the pattern is calculated, and the difference from the reference coordinates x2, y2
Is calculated. Based on these values of X1, Y1, x2, and y2, the positioning position for each film thickness measurement point is calculated and corrected.

Here, the projection / reception optical system 36 may be omitted, and a method of correcting the position when the semiconductor wafer 1 is displaced from the reference position in this case will be described. As shown in FIG. 8, when the origin O (0,0) is deviated to the point O ′ (a, b) because the semiconductor wafer 1 is tilted by the angle θ and deviated from the reference position, on the semiconductor wafer 1 Each film thickness measurement point is also erroneously recognized by the measurement main body terminal 31.

In order to solve such a problem, conversion from the xy coordinate axes before the positional displacement to the XY coordinate axes after the positional displacement is performed. Here, the alignment to the point A, which is the first reference position, is performed on the assumption that the semiconductor wafer 1 is not displaced. Therefore, the point A is (X
_1, Y ₁₎ and becomes, (X _1, Y ₁₎ reference position points in the xy coordinate axes before positional deviation because only recognize not performed in the xy coordinate axis when attempting aligned A'(x _11, y
₁₁ ) will be aligned.

Positioning to the point B which is the second reference position is also performed. In this case as well, the point B is (X ₂ , Y ₂ ) on the XY coordinate axes, but is similarly aligned with the point B '(x ₂₁ , y ₂₁ ) on the xy coordinate axes.

As numerical values, X ₁ = x ₁₁ , Y ₁ =
y ₁₁ , X ₂ = x ₂₂ , and Y ₂ = y ₂₂ . here,
Position of the reference pattern formed on the semiconductor wafer 1 (X
T for the positions (x ₁₂ , y ₁₂ ) and (x ₂₂ , y ₂₂ ) on the xy coordinate axes corresponding to ₁ , Y ₁ ) and (X ₂ , Y ₂ ).
The image is obtained by the V camera 37 and obtained.

Therefore, (X ₁ , Y ₁ ) and (x ₁₂ ,
By substituting y ₁₂ ), (X ₂ , Y ₂ ) and (x ₂₂ , y ₂₂ ) into the following equation, unknown values a, b and θ can be obtained. This equation is considered to be a ternary linear equation. x = (X + a) cos θ− (Y + b) sin θ (2) y = (X + a) sin θ + (Y + b) cos θ (3) The semiconductor wafer 1 is inclined by using the equations (2) and (3) in which these unknowns are obtained. Even by measuring the values of x and y, it is possible to convert these equations (2) and (3) into XY coordinate axes, and as a result of misregistration correction, accurately position each film thickness point on the semiconductor wafer 1. be able to.

In the polishing main unit 10, the upper rotary table 7 may not rotate, and the lower rotary table 5 and the upper rotary table 7 may rotate in the same direction. (2) Next, a second embodiment of the present invention will be described.
The same parts as those in FIG. 1 are designated by the same reference numerals.

FIG. 9 is a block diagram of the polishing apparatus. As shown in FIG. 20, this polishing apparatus has an insulating film 4 ′ and an insulating film pattern 4 such as SiO ₂ on a silicon substrate 2.
a is formed, and a polishing process is performed on the semiconductor wafer 1 on which the metal film 3a such as Al is formed.
It has a function of discriminating as an end point of the polishing process for the insulating film 4 on the semiconductor wafer 1.

The radius of the lower rotary table 5 is formed larger than the diameter of the semiconductor wafer 1, and the semiconductor wafer 1 is arranged outside the center of the lower rotary table 5, as described above.

The diameter of the upper turntable 7 is set to be slightly larger than the diameter of the semiconductor wafer 1 as in the above. A disc-shaped plate electrode 40 is embedded in the lower rotary table 5. As shown in FIG. 10, the embedding position of the plate electrode 40 is provided outside the center of the lower rotary table 5, that is, so that the center of rotation of the upper rotary table 7 and the center of the plate electrode coincide with each other.

The flat plate electrode 40 is formed to have a diameter substantially the same as the diameter of the semiconductor wafer 1. The disk-shaped metal plate 41 embedded in the lower rotary table 5 and the surface of the metal plate 41. It is formed of a disk-shaped dielectric 42 provided above.

Of these, the dielectric 42 is formed to have a dielectric constant e and a thickness d, and is provided so that the surface thereof coincides with the surface of the cloth 6. The abrasive nozzle 8 is
The abrasive S is supplied onto the cloth 6, and the dielectric constant of the abrasive S is e ₁ .

On the other hand, the capacitance detection circuit 43 is electrically connected to the lower rotary table 5. The electrostatic capacitance detection circuit 43 has a function of detecting the electrostatic capacitance C formed between the plate electrode 40 and the metal film 3a on the semiconductor wafer 1 and outputting the electrostatic capacitance detection signal c. ing.

The output terminal of the electrostatic capacitance detection circuit 43 is connected to the arithmetic processing circuit 45 via the interface (I / F) 44. An encoder 46 is connected to the drive source 11 of the lower rotary table 5.
The encoder 46 has a function of outputting a pulse signal according to the rotation speed of the lower rotary table 5. The output terminal of the encoder 46 is connected to the arithmetic processing circuit 45 via the interface 47.

The arithmetic processing circuit 45 includes an encoder 46.
The position of the flat plate electrode 10 on the rotating lower rotary table 5 is detected by inputting the pulse signal output from the flat plate electrode 10, and the flat plate electrode 10 is positioned below the semiconductor wafer 1 attracted to the upper rotary table 7. At a timing, the electrostatic capacitance detection signal c output from the electrostatic capacitance detection circuit 43 is fetched, and the flat plate electrode 10 and the metal film 3a on the semiconductor wafer 1 are taken.
It has a function as a polishing control means for controlling the polishing processing time for the metal film 3a based on the change of the electrostatic capacitance C formed between and.

Specifically, the arithmetic processing circuit 45 operates when the capacitance C formed between the metal plate 41 of the plate electrode 40 and the metal film 3a changes more rapidly than a predetermined range. Is determined as the end point of the polishing processing for the polishing processing, and the polishing processing end point signal g is determined by, for example, the polishing control unit 1.
3 has the function of sending the data.

The predetermined range here means a range of capacitance that can be set between the metal plate 41 and the metal film 3a. Next, the operation of the apparatus configured as described above will be described with reference to the flowchart of the polishing processing end point shown in FIG.

The polishing main unit 10 carries out step # 1.
At, the polishing process is performed on the semiconductor wafer 1. That is, the semiconductor wafer 1 is vacuum-sucked on the lower portion of the upper rotary table 7 and pressed against the cloth 6 on the lower rotary table 5.

In this case, the semiconductor wafer 1 has the insulating film 4'and the insulating film pattern 4a such as SiO ₂ formed on the silicon substrate 2 as shown in FIG. 3a is formed, the silicon substrate 2 side is adsorbed on the upper rotary table 7, and the metal film 3 is formed.
The a side is in contact with the lower rotary table 5.

In this state, the lower rotary table 5 and the upper rotary table 7 are opposite to each other, that is, the lower rotary table 5 rotates in the arrow A direction and the upper rotary table 7 rotates in the arrow B direction.

At the same time, the abrasive S is supplied from the abrasive nozzle 8 onto the cloth 6. In this way, the semiconductor wafer 1 is contacted and pressed against the cloth 6, and the metal film 3a of the semiconductor wafer 1 is gradually thinned as the upper and lower rotary tables 5 and 7 rotate with each other. .

When the lower rotary table 5 is thus rotated and the semiconductor wafer 1 is placed right above the flat plate metal 40, as shown in FIG. 12, the dielectric 42 of the flat plate electrode 40 and the metal film 3a are formed. The concave and convex voids are filled with the abrasive S.

The average value of the voids between the dielectric 42 and the metal film 3a is equal to the three-dimensional center line depth d ₁ of the unevenness of the metal film 3a as shown in FIG. Therefore, the plate electrode 40 and the metal film 3a form a parallel plate capacitor having the dielectric 42 having the thickness d and the dielectric constant e, and the dielectric having the thickness d ₁ and the dielectric constant e ₁ .

The capacitance C of this parallel plate capacitor is represented by C = k · Sa / {(d / e) + (d ₁ / e ₁ )} (4). Here, Sa is the area of the plate electrode 40,
k is a constant.

When this equation (4) is modified, d ₁ = e ₁ / C {k · Sa−C · d / e} (5)

Therefore, by measuring the electrostatic capacitance C of the parallel plate capacitor, the center line depth d _{1 of} the metal film 3a can be obtained. The center line depth d ₁ of the metal film 3a is flattened and gradually becomes smaller as the metal film 3a of the semiconductor wafer 1 is polished.

However, when the metal film 3a is being polished, the electrostatic capacitance detection circuit 43 detects the electrostatic capacitance C formed between the plate electrode 40 and the metal film 4a, and the electrostatic capacitance C is detected. The capacitance detection signal c is output.

On the other hand, the encoder 46 outputs a pulse signal according to the rotation angle of the lower rotary table 5. The arithmetic processing circuit 45 receives the pulse signal output from the encoder 46 and detects the position of the plate electrode 10 on the rotating lower rotary table 5, and the center position of the plate electrode 40 passes the center position of the semiconductor wafer 1. The electrostatic capacitance detection signal c output from the electrostatic capacitance detection circuit 43 is fetched at the timing.

Next, when the arithmetic processing circuit 45 takes in the electrostatic capacitance detection signal c from the electrostatic capacitance detection circuit 43,
The above equation (5) is calculated to obtain the center line depth d ₁ of the metal film 3a. By obtaining the center line depth d ₁ of the metal film 3a, the flatness of the metal film 3a can be known.

Polishing of the metal film 3a proceeds,
As shown in FIG. 14, when the metal film 3a is removed and the insulating film pattern 4a is exposed, the area of the lower counter electrode on the metal film 3a side of the parallel plate capacitor including the flat plate electrode 40 and the metal film 3a changes abruptly. Therefore, the values of the capacitance C and the center line depth d ₁ of the metal film 3a, which are obtained in the arithmetic processing circuit 45, change abruptly.

Therefore, the arithmetic processing circuit 45 includes the metal film 3a.
The time when the calculated value of the center line depth d ₁ of the above changes abruptly is detected, and it is detected that the insulating film pattern 4a is exposed at this time.

Here, when the insulating film pattern 4a is exposed and the metal film 3a has a predetermined flatness, the arithmetic processing circuit 45 determines as the end point of the polishing process for the insulating film 4, and the polishing process end point. The signal g is sent to the policing controller 13, for example.

That is, the arithmetic processing circuit 45, in step # 2, changes Δ in the center line depth d ₁ of the metal film 3a.
It is determined whether d ₁ is larger than a judgment value Δl for detecting the exposure of the insulating film. If the change amount Δd ₁ is smaller than the judgment value Δl, it is judged that the metal film 3a remains, and the change amount Δd _{If 1} is larger than the judgment value Δl, insulating film pattern 4
It is determined that a is exposed.

Next, in step # 3, the arithmetic processing circuit 45 determines that the center line depth d ₁ of the metal film 3a is equal to the center line depth d ₁ for determining whether the metal film 3a has good flatness. It is determined whether or not the size is less than or equal to the determination value L. As a result of this determination, if the center line depth d _{1 of} the metal film 3a is less than or equal to the determination value L, the flatness is good and the center line depth of the metal film 3a is good. If the depth d ₁ is greater than or equal to the determination value L, it is determined that the flatness is poor, and step # 4
Then, the polishing process is continued for a fixed time T.

As described above, in the second embodiment, the electrostatic capacitance C formed between the flat plate electrode 40 provided on the lower rotary table 5 and the metal film 3a is detected, and the electrostatic capacitance C is detected. Since the change in C, that is, the sudden change in the capacitance C is determined as the end point of the polishing process for the metal film 3a, when the insulating film pattern 4a is exposed during the polishing process for the metal film 3a. By judging that the flatness of the metal film 3a is optimum, the end point of the polishing process for the metal film 3a can be detected with high accuracy, and the polishing process for the metal film 3a can be completed.

Therefore, by adding the second embodiment to the polishing main body device 10, the wafer transfer device 20, and the thin film measuring device 30 in the first embodiment, the polishing machine can be on-machine. The film thickness of the metal film 3a can be measured with high accuracy, and the end point of the polishing process for the metal film 3a can be detected with high accuracy.

The second embodiment may be modified as follows. For example, the upper rotary table 7 does not have to rotate, and the lower rotary table 5 and the upper rotary table 7 may rotate in the same direction.

To detect the measurement position of the capacitance C, a photo sensor may be attached to the upper rotary table 7 to detect the position of the plate electrode 40. Also, the plate electrode 40
Since it suffices to cover the entire surface of the semiconductor wafer 1,
The shape is not limited to the disk shape, and may be another shape. (3) Next, a third embodiment of the present invention will be described.
The same parts as those in FIG. 1 are designated by the same reference numerals.

FIG. 15 is a block diagram of the polishing apparatus.
As shown in FIG. 18, this polishing apparatus includes an insulating film 4 ′ and a metal pattern 3 such as SiO ₂ on a silicon substrate 2.
Is formed, and polishing processing is performed on the semiconductor wafer 1 on which the insulating film 4 such as Al is formed. The polishing processing has a function of determining the end point of the polishing processing on the insulating film 4 on the semiconductor wafer 1.

The radius of the lower rotary table 5 is formed larger than the diameter of the semiconductor wafer 1, and the semiconductor wafer 1 is arranged outside the center of the lower rotary table 5, as described above.

The diameter of the upper rotary table 7 is set to be slightly larger than the diameter of the semiconductor wafer 1 as in the above. An AE (Acoustic Emission: Ultrasonic Output) sensor 50 is attached to the lower rotary table 5 immediately below the cross 6 and is attracted to the upper rotary table 7 by rotating the lower rotary table 6 in the direction A as shown in FIG. The semiconductor wafer 1 is provided at a position passing through the center of the semiconductor wafer 1.

The AE sensor 50 has a function of detecting an ultrasonic wave generated when polishing the insulating film 4 of the semiconductor wafer 1 and outputting a sound detection signal a thereof. The preamplifier 5 is connected to the output terminal of the AE sensor 50.
1. A counter 53 is connected via the discriminator 52.

The counter 53 has a function of taking in the sound detection signal a output from the AE sensor 50 through the preamplifier 51 and the discriminator 52 and counting it.

The encoder 54 is connected to the drive source 11 of the lower rotary table 5. The encoder 54 has a function of outputting a pulse signal according to the rotation speed of the lower rotary table 5. This encoder 54
The output terminal of is connected to the arithmetic processing circuit 56 via the interface 55.

The arithmetic processing circuit 56 includes an encoder 54
The position of the AE sensor 50 on the lower rotary table 5 which rotates by inputting the pulse signal output from
At the timing when the E sensor 50 passes under the semiconductor wafer 1, the count value of the sound detection signal a output from the AE sensor 50 is counted by the counter 53 via the interface 57.
It has a function as a polishing control unit that controls the time of the polishing process for the insulating film 4 based on the change of the ultrasonic wave that is taken in from the AE sensor 50 and generated by the AE sensor 50 during the polishing process.

Specifically, the arithmetic processing circuit 56 determines as the end point of the polishing process for the insulating film 4 when the change of the ultrasonic waves generated during the polishing process becomes constant, and the polishing process end signal g. Is sent to the policing control unit 13, for example.

Next, the operation of the apparatus configured as described above will be described. The polishing main body device 10 performs a polishing process on the semiconductor wafer 1. That is, the semiconductor wafer 1 is vacuum-sucked on the lower portion of the upper rotary table 7 and pressed against the cloth 6 on the lower rotary table 5.

In this case, in the semiconductor wafer 1, the silicon substrate 2 side is adsorbed on the upper rotary table 7 and the insulating film 4 is formed.
The side is in contact with the lower rotary table 5. In this state,
The lower rotary table 5 and the upper rotary table 7 are opposite to each other, that is, the lower rotary table 5 rotates in the arrow A direction and the upper rotary table 7 rotates in the arrow B direction.

At the same time, the abrasive S is supplied from the abrasive nozzle 8 onto the cloth 6. In this way, the semiconductor wafer 1 is contacted and pressed against the cloth 6, and the insulating film 4 of the semiconductor wafer 1 is gradually thinned by the mutual rotation of the upper and lower rotary tables 5, 7. .

As described above, when the insulating film 4 is rubbed and worn, ultrasonic waves are generated. The AE sensor 50 detects an ultrasonic wave generated during the polishing process on the insulating film 4 and outputs a sound detection signal a thereof.

This sound detection signal a is input to the counter 53 through the preamplifier 51 and the discriminator 52,
Counted here. On the other hand, the encoder 54 outputs a pulse signal according to the rotation angle of the lower rotary table 5.

The arithmetic processing circuit 56 receives the pulse signal output from the encoder 54 and detects the position of the AE sensor 50 on the lower rotary table 5 which rotates, and the AE sensor 50 crosses below the semiconductor wafer 1. At a timing, the count value of the sound detection signal a output from the AE sensor 50 is fetched from the counter 53.

Next, the arithmetic processing circuit 56 takes in the count value of the sound detection signal a and calculates and obtains the AE count rate per unit time. Here, as for the relationship between the AE count rate and the polishing time, as shown in FIG. 17, the AE count rate decreases as the polishing progresses and the insulating film 4 becomes flat, and becomes a constant value when the insulating film 4 becomes flat. . The end of the polishing time is when the AE count rate becomes a constant value.

Therefore, the arithmetic processing circuit 56 detects, for example, when the change of the AE count rate becomes constant by differentiating,
When the AE count rate becomes constant, it is determined as the end point of the polishing process for the insulating film 4, and the polishing process end signal g is sent to the polishing controller 13, for example.

As described above, in the third embodiment, the ultrasonic wave generated during the polishing process on the insulating film 4 is detected, and the insulating film is detected when the AE count rate based on the ultrasonic wave becomes constant. Since the end point of the polishing process for the insulating film 4 is determined, the end point of the polishing process for the insulating film 4 is accurately determined by determining that the flatness of the insulating film 4 is optimum during the polishing process for the insulating film 4. It can be detected, and the polishing process for the insulating film 4 can be completed.

Further, since the sound detection signal a from the AE sensor 50 is counted at the timing when the AE sensor 50 crosses the lower side of the semiconductor wafer 1, it is possible to detect the ultrasonic waves generated when the insulating film 4 is polished. The S / N can be improved.

Further, by adding the third embodiment to the polishing main body device 10, the wafer transfer device 20, and the thin film measuring device 30 in the first embodiment, the polishing machine can be on-machine. Insulation film 4 with high accuracy
The film thickness can be measured and the end point of the polishing process for the insulating film 4 can be detected with high accuracy.

The third embodiment may be modified as follows. For example, in the above third embodiment,
Although the case of applying it to the polishing process for the insulating film 4 has been described, it may be applied to the polishing process for the metal film 3a in the semiconductor wafer 1 shown in FIG. 20 or may be applied to a general polishing process.

Further, the upper rotary table 7 may not rotate, and the lower rotary table 5 and the upper rotary table 7 may rotate in the same direction. To detect the semiconductor wafer 1, a photosensor may be attached to the upper rotary table 7 to detect the end surface of the semiconductor wafer 1.

Further, the sound detection signal a from the AE sensor 50 may be continuously taken in during the rotation of the lower turntable 5. Then, the AE sensor 50 may be attached to the upper rotary table 7.

Further, the AE sensor 50 is the semiconductor wafer 1
S / N can be improved by capturing the output of the AE sensor 50 when the AE sensor 50 does not cross below the semiconductor wafer 1 as noise and subtracting the noise component from the sound detection signal a when the AE sensor 50 crosses below the semiconductor wafer 1.

[0151]

As described above in detail, according to the present invention, it is possible to provide a film thickness measuring device capable of accurately measuring the film thickness formed on a substrate. Further, according to the present invention, it is possible to provide a film thickness measuring device capable of accurately measuring the film thickness formed on the substrate on-machine on the polishing device.

Further, according to the present invention, the film thickness formed on the substrate is accurately measured by the on-machine on the polishing device,
It is possible to provide a polishing apparatus that can control the film thickness by the polishing process with high accuracy to improve the throughput of the polishing apparatus and eliminate the cost loss due to the test wafer.

Further, according to the present invention, it is possible to provide a polishing apparatus capable of accurately determining that a film having a predetermined thickness is formed when polishing the film. Further, according to the present invention, it is possible to provide a polishing apparatus capable of accurately determining the processing end point when forming a film on a film and forming the film to a predetermined film thickness.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing a first embodiment of a polishing device to which a film thickness measuring device according to the present invention is applied.

FIG. 2 is a specific configuration diagram of a measurement main body terminal and an electrical component section of the film thickness measurement device.

FIG. 3 is a specific configuration diagram of a measurement main body terminal.

FIG. 4 is a diagram showing reference positions of cross marks and square marks that are reference patterns.

FIG. 5 is a diagram showing the positions of imaged cross marks and square marks.

FIG. 6 is a diagram showing interference of a thin film.

FIG. 7 is a diagram showing an interference spectrum.

FIG. 8 is a diagram for explaining a method of correcting a position when a semiconductor wafer is displaced from a reference position.

FIG. 9 is a configuration diagram showing a second embodiment of a polishing apparatus according to the present invention.

FIG. 10 is a diagram showing the positions of flat plate electrodes on a lower rotary table.

FIG. 11 is a flowchart of a polishing processing end point.

FIG. 12 is a layout drawing when the center of the semiconductor wafer is aligned with the center of the plate electrode.

FIG. 13 is a diagram showing a center line depth of a metal film.

FIG. 14 is a view showing an end point of polishing processing.

FIG. 15 is a configuration diagram showing a third embodiment of a polishing apparatus according to the present invention.

FIG. 16 is a diagram showing an arrangement position of an AE sensor.

FIG. 17 is a diagram showing an end point of polishing processing by an AE count rate.

FIG. 18 is a configuration diagram of a polishing device.

FIG. 19 is a diagram showing a planarization process of a semiconductor manufacturing process.

FIG. 20 is a structural diagram of another semiconductor wafer.

FIG. 21 is a diagram showing an end point of flattening by polishing.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Semiconductor wafer, 4 ... Insulating film, 10 ... Polishing main body apparatus, 20 ... Wafer transfer apparatus, 30 ... Thin film measuring apparatus, 3
1 ... Measuring main body terminal, 32 ... Measuring unit, 33 ... Box, 3
4 ... Positioning table, 35 ... Left side projection / reception optical system, 36
... Right side projection / reception optical system, 37, 38 ... TV camera, 39 ...
Observation window, 320 ... XYθ table driver, 321, 3
22 ... Camera control unit, 323 ... Image positioning device, 324 ... Light source, 325 ... Interferometric film thickness meter, 3
26 ... Arithmetic control device, 40 ... Flat plate electrode, 41 ... Metal plate,
42 ... Dielectric material, 43 ... Capacitance detection circuit, 45 ... Arithmetic processing circuit, 46 ... Encoder, 50 ... AE sensor (acoustic emission sensor), 53 ... Counter, 54 ... Encoder, 56 ... Arithmetic processing circuit.

Claims (13)

[Claims] 1. A film thickness measuring device for measuring the film thickness by irradiating a substrate having a light-transmitting film formed on its surface with light and detecting interference fringes generated by reflected light from the substrate. A film thickness measuring apparatus, comprising: a measuring main body terminal internally provided with a light projecting and receiving optical system for irradiating the substrate with at least the light from above and receiving reflected light from the substrate. 2. The measurement main body terminal includes a light projecting / receiving optical system for irradiating light onto a substrate and receiving reflected light from the substrate, and a positioning table for moving the light projecting / receiving optical system in the XYθ directions. 2. An apparatus for measuring film thickness according to claim 1, further comprising: an image pickup device for picking up an image projected through the light projecting and receiving optical system, and an observation window is provided in the container at a portion facing the light projecting and receiving optical system. . 3. A measuring main body terminal for detecting an interference fringe generated by reflected light from a substrate having a light-transmitting film formed on its surface when the substrate is irradiated with light from at least above, and the measuring main body terminal. And a measuring means for determining the film thickness based on the interference fringes detected by, the measurement main body terminal, in the container, projecting and receiving optical system for irradiating light onto the substrate and receiving reflected light from the substrate, A positioning table for moving the projection / reception optical system in the XYθ directions; and an image pickup device for picking up an image projected through the projection / reception optical system, and an observation window is provided in the container at a portion exposed by the projection / reception optical system, The measuring means obtains a difference with respect to the reference coordinates of the substrate based on the image data of the substrate taken by the image pickup device, and the position for driving the positioning table based on the difference. Because means and said and a film thickness meter to determine the thickness from the detected interference fringe by measuring body terminal, the film thickness measuring apparatus according to claim. 4. The film thickness measuring device according to claim 2, wherein the measurement main body terminal is hermetically sealed. 5. The film thickness measuring device according to claim 2, wherein the observation window is provided so as to be inclined with respect to the optical axis of the irradiation light from the light projecting and receiving optical system. 6. A light-transmitting film formed on a substrate is subjected to a polishing process to flatten the film, after which the substrate is irradiated with light, and is generated by reflected light from the substrate. In a polishing apparatus for measuring the film thickness by detecting interference fringes, at least the light is radiated onto the substrate from above, and a projection / reception optical system for receiving reflected light from the substrate is provided inside the container. And a polishing control means for controlling the time of the polishing process based on the measured value of the film thickness. 7. A light-transmitting film formed on a substrate is subjected to a polishing process to flatten the film, after which the substrate is irradiated with light and reflected light from the substrate produces light. In a polishing apparatus for detecting interference fringes to measure the film thickness, at least a measuring main body terminal for detecting interference fringes generated by reflected light from the substrate when the substrate is irradiated with light from above, and a measuring main body. A measuring means for determining the film thickness based on interference fringes detected by a terminal, wherein the measuring main body terminal irradiates light onto a substrate and receives light reflected from the substrate in the container. A positioning table for moving the projection / reception optical system in the XYθ directions, and an image pickup device for picking up an image projected through the projection / reception optical system, An observation window is provided in the container, the measuring means obtains a difference with respect to the reference coordinates of the substrate based on the image data of the substrate imaged by the image pickup device, and a positioning means for driving the positioning table based on the difference. A film thickness meter for obtaining a film thickness from interference fringes detected by the measurement main body terminal, and a polishing control means for controlling the time of the polishing process based on the measured value of the film thickness obtained by the film thickness meter. And a polishing apparatus. 8. A substrate on which a film is formed is sandwiched between a first rotary table and a second rotary table, and at least one of the first and second rotary tables is rotated to polish the film. In a polishing device for processing, an electrode provided on the lower rotary table side of the first or second rotary table and in contact with the film, and a capacitance formed between the electrode and the film are detected. And a polishing control means for controlling a polishing processing time for the film based on a change in the capacitance detected by the capacitance detection means. apparatus. 9. The electrode is composed of a metal plate embedded in one of the first and second turntables and a dielectric material disposed between the metal plate and the film. 9. The polishing apparatus according to claim 8, wherein the polishing apparatus is a polishing apparatus. 10. The polishing control means has a function of determining when the capacitance formed between an electrode and the film suddenly changes from a predetermined range as an end point of the polishing process for the film. The polishing apparatus according to claim 8, wherein the polishing apparatus is a polishing apparatus. 11. A substrate on which a film is formed is sandwiched between a first rotary table and a second rotary table, and at least one of the first and second rotary tables is rotated to polish the film. In the polishing apparatus, the sound detection means is provided on either the first or the second rotary table and detects a sound generated during the polishing process on the film, and the sound detection means detects the sound. A polishing control means for controlling a polishing processing time for the film based on a change in sound. 12. The sound detecting means has a function of capturing a sound generated during polishing when the film crosses in synchronization with the rotation of the first or second rotary table. The polishing apparatus according to claim 11. 13. The polishing control means has a function of determining an end point of polishing processing for the film when a rate of change of sound generated during polishing processing becomes constant. The polishing device described.