JPH09145612A - Method and device for inspecting electric field responsive impurity - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect electric field responsive impurity mixed in an insulation film and a liquid crystal orientation film formed in the middle of manufacturing of a device, by, after time-analyzing the electric signal converted with a photodetecting means, providing a means taking out the integration signal wherein the electric signal is integrated. SOLUTION: Under the condition that a high polymer film and a polyimide film are made to adhere to each other, the pulse signal generated by a pulse generator 1 such as a synthesizer, etc., is applied between an ITO electrode of a sensor head 10 and that on a to-be-inspected material side. Meanwhile, the high polymer film of the sensor head 10 is irradiated with infrared ray from an infrared source 2 through a polarizer 3, and the infrared ray that the high polymer film transmits is converted into an electric signal with an infrared detecting means (photodetecting means) 4 (distributed infrared spectrophotometer and an MCT detector), for detection. The electric signal is amplified with a preamplifier 5 and a main amplifier 6, and inputted into a digital sampling oscilloscope 7 and time-analyzed, for integration. The whole inspection device is controlled with a computer 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and method for inspecting electric field-responsive impurities mixed in a thin film or the like constituting an electronic component.

[0002]

2. Description of the Related Art Thin films for advanced devices, represented by insulating films of semiconductor devices, low dielectric constant films, and liquid crystal alignment films of liquid crystal displays, are impurities that respond to an electric field in order to satisfy required electrical characteristics. I hate to mix in. For example, in a TFT-driven liquid crystal panel, when electric field-responsive impurities are mixed in the liquid crystal layer, defects such as white spot defects may occur.
In order to control the manufacturing process of such a device, it is of course important to prevent impurities from being mixed in during the process work, but it is also demanded to quickly remove defective products containing impurities.

However, conventionally, there is no simple inspection means, and it is difficult to remove defective products containing impurities before reaching the final product. For this reason, in a semiconductor device, after completing a wiring and completing it as a product, the electrical characteristics are measured and the defective element is removed. For liquid crystal displays, an acceleration test is performed after the panel is completed, and the degree of decrease in the voltage holding ratio is checked to determine whether it is good or bad. Therefore, a product determined to be defective is wasteful because it must be discarded even though it has been manufactured through many steps.

An inspection device for detecting ionic impurities in the liquid crystal display by electrical measurement is commercially available (Toyo Technica Co., Ltd.). Specifically, a low-frequency triangular wave is applied to the liquid crystal cell, and the Lissajous waveform of the current / voltage signal is analyzed to obtain the ion density in the liquid crystal cell. However, again, a liquid crystal panel is required for the measurement, and this device
When trying to apply to the inspection of the FT drive type panel,
There is a drawback in that accurate measurement cannot be performed because the FT has an electric capacity.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide an inspection apparatus and an inspection method capable of detecting electric field responsive impurities mixed in an insulating film or a liquid crystal alignment film formed during the manufacture of a device. The purpose is to eliminate the waste of the manufacturing process by removing defective products generated before the product is completed.

[0006]

An inspection apparatus for electric field responsive impurities according to the present invention is an apparatus for inspecting electric field responsive impurities present in an object to be inspected on a conductive substrate, and the conductive substrate Electrodes arranged to face each other, a polymer film containing a uniaxially oriented side chain or low molecular weight compound showing electric field responsiveness, which is adhered between the electrode and an object to be inspected, the electrode and the conductive substrate Means for applying an alternating pulse electric field whose polarity reverses with time, a light source for irradiating the polymer film between the electrode and the inspection object, and the polymer irradiated from the light source. A light detecting means for spectrally converting the light passing through the film and converting it into an electric signal; and a means for taking out an integrated signal obtained by integrating the electric signal converted by the light detecting means with time. It is a feature.

The means for taking out the integrated signal may further include a signal analysis means for calculating the slope of the electric field response curve showing the change with time of the integrated signal. Further, in the inspection apparatus of the present invention, means for driving the electrodes in a direction orthogonal to the surface of the inspection object and means for feeding the polymer film parallel to the surface of the inspection object are provided. The exchange of the polymer membrane may be facilitated.

The inspection method for electric field responsive impurities of the present invention is as follows:
When inspecting electric field responsive impurities existing in an inspection object on a conductive substrate, the inspection object is a polymer film and a electrode containing a uniaxially oriented side chain or low molecular weight compound showing an electric field response. By irradiating light while applying an alternating pulse electric field whose polarity is alternately inverted between the electrode and the conductive substrate by pressing, and measuring the time-resolved light passing through the polymer film. Obtaining an electric field response curve corresponding to the change over time of the light intensity, based on the slope of the electric field response curve within the time of each pulse width of the applied pulse electric field, the electric field responsive impurities in the inspection object. It is characterized by detecting. In the inspection method of the present invention, it is desirable to intervene between the polymer film and the object to be inspected with a non-volatile and electric field non-responsive solvent.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. The object to be inspected in the present invention is generally an insulating film or a liquid crystal alignment film formed on a conductive substrate such as a semiconductor substrate or a transparent substrate of a liquid crystal cell on which a transparent electrode is formed. Impurities having a property of responding to an electric field (electric field-responsive impurities) may be mixed into these films during the process operation. An electric field responsive impurity is a chemical species that has the ability to move within the device or move an electric charge with the application of an electric field, such as a proton, an organic ion, an inorganic ion, a compound having a hydrogen bonding ability, and an electron transfer. Examples thereof include compounds having an ability, compounds having a large dipole moment, compounds having a large polarizability, and the like.

In the present invention, a polymer film in which a functional group having an electric field responsiveness is introduced into a side chain or a low molecular weight compound having an electric field responsiveness is dispersed is uniaxially oriented to an object to be inspected. The electrodes are brought into close contact with each other.

In the present invention, since the polymer film is generally irradiated with light through an electrode to carry out an inspection as described later, an electrode transparent to the detection light is used as the electrode. Usually, such electrodes are formed on a transparent substrate. IT
A glass substrate or a quartz substrate having an O electrode deposited thereon can be preferably used.

In the present invention, the material of the polymer film is not particularly limited as long as it can form a film having a thickness of 10 to 20 μm. However, if the main chain of the polymer has absorption in the wavelength range of the detection light, the intensity of the light passing through the polymer film becomes weak and the S / N ratio between the time-resolved signal and noise deteriorates. It is required that the absorption is small in the wavelength range of. Preferred polymer materials include polyether, polyvinyl chloride, polyethylene, polypropylene, polyacrylic acid ester, polymethacrylic acid ester, polycarbonate, polyimide, polyamide, polyamic acid, polyethylene terephthalate and the like.

The functional group having electric field responsiveness introduced into the side chain of the polymer film or the low molecular compound having electric field responsiveness dispersed in the polymer film has absorption in the wavelength range of detection light. It is not particularly limited as long as it is a compound, but a compound having a skeleton corresponding to the mesogenic skeleton of the liquid crystal compound is preferable. Examples of the mesogen skeleton include phenyl, biphenyl, anthranyl, cyclohexylphenyl, stilbene, azobenzene, and aromatic imine. When a low molecular weight compound is used in the present invention, the molecular weight thereof is preferably 1000 or less in order to promptly induce motion of the low molecular weight compound when an AC pulsed electric field is applied.

In order to uniaxially orient the functional group of the polymer side chain or the low molecular weight compound dispersed in the polymer film, a method of stretching the polymer film, a method of applying an electric field during the production of the polymer film, or A method of applying a magnetic field is used during the production of the polymer film.

In the present invention, the light irradiated to the polymer film for detecting the electric field responsive impurities is not easily absorbed by the polymer main chain, and is in the wavelength range where it is absorbed by the side chain functional group or the low molecular weight compound. There is no particular limitation as long as it is ultraviolet, visible, or infrared. For example, in the case of a polymer film in which a cyanobiphenyl group is introduced into the side chain of polymethylmethacrylate to impart uniaxial orientation, light having a wavelength in the specific absorption region of the cyano group is used. With such detection light,
The S / N ratio between the time-resolved signal and noise can be dramatically improved.

The principle of the present invention will be briefly described below. In the present invention, the object to be inspected formed on the conductive substrate, the polymer film containing a side chain or a low molecular weight compound having uniaxially oriented electric field responsiveness and an electrode are pressed to press the object to be inspected and the polymer. An AC pulse electric field whose polarity is alternately inverted is applied between the electrode and the conductive substrate in the state where the film and the conductive substrate are in close contact with each other. When an AC pulsed electric field is applied to the polymer film in this way, the movement of the side chain functional group or the low molecular weight compound exhibiting the electric field response in the polymer film is induced. In this state, the polymer film is irradiated with light (for example, infrared light) to detect the intensity of transmitted light, and the change is time-resolved and measured. From this result, electric field response curves corresponding to changes in transmitted light intensity with time are obtained for pulsed electric fields having polarities different from each other. The intensity of the reflected light may be detected after entering the polymer film.

At this time, the obtained electric field response curve changes depending on whether or not the object to be inspected contains electric field responsive impurities. That is, when an electric field responsive impurity is mixed in the inspection object and the AC pulsed electric field is applied to the inspection object, the electric field responsive impurities in the inspection object move toward the polymer film, and It is either taken into the molecular film or accumulated at the interface between the object to be inspected and the polymer film to form an electric double layer. Since a part of the applied electric field acts on the electric field responsive impurities, the electric field effectively applied to the side chain or the low molecular weight compound showing the electric field responsiveness in the polymer film is reduced. As a result,
The gradient of the electric field response curve changes variously within the pulse width of the AC pulse electric field applied to the polymer film. The manner in which the slope of the electric field response curve changes depends not only on the amount and type of impurities, but also on the polarity of the applied electric field when the amount of impurities exceeds a certain level. Therefore, by analyzing the slope of the electric field response curve when pulse electric fields having different polarities are applied, it is possible to detect, identify, and quantify the impurities mixed in the inspection object.

In the present invention, in order to facilitate the migration of impurities from the object to be inspected to the polymer film during the above-mentioned measurement, a non-volatile material is provided between the object to be inspected on the conductive substrate and the polymer film. A solvent that is permeable and does not respond to an electric field may be interposed.
The solvent used here is preferably one that does not dissolve or swell the test object, and examples thereof include cyclohexanone, hexane, and acetone.

As the light used in the present invention, infrared light as described above is particularly preferable from the viewpoint of obtaining an electric field response curve with high sensitivity. Further, the waveform of the AC pulse electric field used in the present invention is not particularly limited, and a rectangular wave, a triangular wave, a sine wave, a composite wave thereof, or the like can be used. Here, the pulse width in the present invention means the time T corresponding to 1/2 cycle of the fundamental wave, that is, the AC pulsed electric field, regardless of whether the fundamental wave forming the AC pulsed electric field is a rectangular wave, a triangular wave, or a sine wave. It means the minimum time for which an electric field of one polarity is applied to the object to be inspected for each of the fundamental waves.

Further, the manner of changing the slope of the electric field response curve described above differs depending on the pulse width of the applied AC pulse electric field, and the manner of changing depending on the pulse width is peculiar to each impurity. This will be described more specifically below. When an electric field is applied to the inspection object, the electric field responsive impurities in the inspection object move in response to the electric field. Next, when the polarity of the electric field is reversed, the direction of the force acting on the electric field responsive impurity is reversed, and the impurity moves in the opposite direction. However, when the pulse width becomes smaller, the reversal of the movement of impurities cannot be followed even if the polarity of the electric field is reversed,
It becomes unobservable due to the electric field response curve. Since the pulse width at which the impurity cannot be observed varies depending on the effective mass and electrical properties of the impurity, the pulse width can be associated with the type of the impurity. Therefore, by changing the pulse width of the AC pulsed electric field and observing the electric field response curve, the impurities mixed in the inspection object can be specified.

Further, if a synthetic AC pulse electric field obtained by synthesizing a plurality of pulse trains having different pulse widths is applied and an electric field response curve corresponding to each pulse train constituting the synthetic AC pulse electric field is observed, it is mixed in the object to be inspected. It is also possible to detect a plurality of specified impurities.

As the inspection device of the present invention, specifically,
For example, a state in which an object to be inspected formed on a conductive substrate is held in a spectroscopic device such as an infrared spectroscopic device capable of spectroscopic measurement and time-resolved signal processing, and electrodes are brought into close contact with each other through the polymer film described above. Then, a means provided with a means for applying an AC pulsed electric field whose polarity reverses with time is used between the electrode and the conductive substrate. The infrared spectroscope used here is an infrared light source and infrared detection means (light detection means) for separating infrared light emitted from the infrared light source and passing through the inspection object into electrical signals. And a means for taking out an integrated signal obtained by integrating the electric signal converted by the infrared detecting means with time. Further, at this time, it is preferable to include signal analysis means for calculating the slope of the electric field response curve showing the change with time of the obtained integrated signal.

Specifically, as the infrared detecting means here,
For example, a combination of a highly sensitive MCT (mercury-cadmium-tellurium) detector and the like and an infrared spectrophotometer is used. On the other hand, a boxcar integrator or a digital oscilloscope is used as a means for taking out an integrated signal obtained by integrating the electric signal converted by the infrared detecting means with time. Since the infrared light to be detected is weak, the electric signal converted by the infrared detecting means is generally amplified by an amplifier.

Further, in the present invention, using such an inspection apparatus, in order to identify a plurality of impurities mixed in the object to be inspected as described above, a plurality of pulse trains having different pulse widths are applied by means for applying an AC pulse electric field. Is applied to the composite AC pulse electric field, the electric signal converted by the infrared detecting means by the means for extracting the signal is decomposed into a plurality of electric signals corresponding to each pulse train constituting the composite AC pulse electric field, After the electric signal is time-resolved, an integrated signal obtained by integrating the electric signal may be taken out.

Further, in the inspection apparatus of the present invention, means for driving the electrodes in a direction orthogonal to the surface of the object to be inspected,
A means for feeding the polymer film parallel to the surface of the object to be inspected (for example, supply roller and winding roller) may be provided. If such a means is provided, after the predetermined inspection is completed, the electrode is driven upward to separate from the object to be inspected, the polymer film is wound up, and an amount necessary for a new measurement is fed.
By driving the electrode downward again to bring the polymer film into close contact with the object to be inspected on the conductive substrate and fixing the same, the exchange of the polymer film can be facilitated and continuous inspection can be performed. Similarly, a means for transporting the conductive substrate on which the inspection object is formed may be provided. Further, in the present invention, the object to be inspected does not necessarily have to be formed on the conductive substrate. For example, the object to be inspected is formed on the conductive substrate as a device configuration in which the conductive substrate is attached on the conveying means. After mounting, the electric field responsive impurities in the inspection object may be inspected.

[0026]

Embodiments of the present invention will be described below. Methacrylic acid 8.8g as monomer 150m dry methylene chloride
It was dissolved in cc, 19.4 g of DCC (dicyclohexylcarbodiimide) was added, and the mixture was reacted at 0 ° C. for 20 minutes. To this solution, a solution prepared by dissolving 25.1 g of 4- (4-hydroxybutyl) -4'-cyanobiphenyl, which is a side chain functional group, in 100 cc of dry methylene chloride was slowly added dropwise. After completion of the dropping, the temperature of the solution was slowly raised to room temperature and the reaction was continued for 1 hour. Then, methylene chloride was distilled off from the reaction solution, and the product was separated and purified by a column. The obtained methacrylic acid ester was heated to 100 ° C. in toluene in the presence of a radical polymerization initiator AIBN (2,2′-azobisisobutyronitrile) to polymerize for 1 hour. After slowly cooling to stop the reaction, the mixture was concentrated and reprecipitated with hexane for purification. From the viscosity measurement of the polymer solution thus obtained, it was found that the polymer had a molecular weight of about 150,000. 60 mg of this polymer was dissolved in 4 cc of THF (tetrahydrofuran), cast on a glass plate, and the solvent was evaporated to form a film. This polymer film was peeled off and cut into 2 cm × 3 cm. When the film thickness of this polymer film was measured with a micro gauge, it was about 12 μm. Next, attach a weight of 500g to this polymer film,
It was stretched at 200 kg / cm ² .

Before and after stretching, the dichroic ratio of the infrared absorption at 2230 cm ⁻¹ , which belongs to the cyano group which is a side chain functional group in the polymer film, was measured to determine the degree of orientation of the cyano group. The ratio of the long axis to the short axis of the cyano group was 1: 1 before stretching, whereas
It became 3: 1 after stretching. From this result, it was found that the side chain functional groups were uniaxially oriented in the stretched polymer film.

On the other hand, a glass substrate 1 of 20 mm × 30 mm
An ITO electrode 12 formed on the surface of No. 1 was prepared, washed with a stream of distilled water for 1 hour, ultrasonically washed with methylene chloride for 5 minutes, and steam washed with chlorofluorocarbon.

Next, as shown in FIG. 1, the glass substrate 11 with the ITO electrode 12 is held on the lower surface of the terminal 13 which also functions as a holding member for the polymer film, and the polymer film 14 is brought into close contact with the ITO electrode 12. In this state, the sensor head 10 was manufactured by fixing it to the side surface of the terminal 13 with a stopper 15. In addition, a solvent-soluble polyimide is applied on the ITO electrode 22 formed on the glass substrate 21 so that the polyimide film 2 to be inspected.
0 was deposited. This polyimide film 20 was exposed to ethanol vapor for 3 hours to mix ethanol, which is an ionic impurity, into the polyimide film. With the polymer film 14 of the sensor head 10 thus obtained and the polyimide film 20 which is the object to be inspected in close contact with each other, an inspection was performed by an inspection device as shown in FIG.

FIG. 2 is a block diagram showing an example of an apparatus for inspecting electric field responsive impurities. In FIG. 2, the polymer film 1
With the polyimide film 20 in close contact with the polyimide film 20, a pulse signal generated by a pulse generator 1 such as a synthesizer is applied between the ITO electrode 12 of the sensor head 10 and the ITO electrode 22 of the object side. On the other hand, the infrared light from the infrared light source 2 is passed through the polarizer 3 to the sensor head 1
The infrared light transmitted through the polymer film 14 is converted into an electric signal by the infrared detecting means (light detecting means) 4 (dispersive infrared spectrophotometer and MCT detector). To detect. The electric signal is amplified by the preamplifier 5 and the main amplifier 6, and is input to the digital sampling oscilloscope 7 to be time-resolved and integrated. The entire inspection device is controlled by the computer 8. The polarizer 3 does not have to be installed.

Further, a composite AC pulse electric field is generated by combining a plurality of pulse trains having different pulse widths, and the electric signal converted by the infrared detecting means 4 is converted into a plurality of electric currents corresponding to each pulse train constituting the composite AC pulse electric field. The control by the computer 8 is also performed when the signal is decomposed.

Using the above inspection apparatus, paying attention to the CN triple bond of the cyano group introduced into the side chain of the polymer film 14, 22
The examination was carried out on the basis of the infrared absorption of the triple bond stretching vibration at 30 cm ^-1 . At this time, the polymer film 14 and the polyimide film 20 are brought into close contact with each other, and after 90 seconds, the movement of ethanol to the interface between them and the inside of the polymer film 14 is stabilized, and then the pulse width is 1 ms and the voltage is ± 7 V. An AC pulse voltage was applied and the electric field response curve was examined. However, here, the polymer film 14 and the polyimide film 20 are brought into close contact with each other for 10 seconds, 3 seconds.
The electric field response curves were measured after 0 seconds, 45 seconds, 60 seconds, 75 seconds, and 90 seconds respectively, and the curves after 75 seconds and 90 seconds were in agreement, so the movement of ethanol was stable after 90 seconds had elapsed. I thought it was done. The result is shown in FIG.

As shown in FIG. 3, the slope of the electric field response curve within the pulse width time largely changes before and after the polarity of the electric field is reversed, and depending on whether the polarity of the pulse applied first is positive or negative. Two electric field response curves with different slope changes were observed. That is, when the polarity of the pulse applied first is positive, the slope of the electric field response curve is gentle before the polarity of the electric field is inverted and becomes large after the polarity is inverted, as indicated by a in FIG. On the contrary, when the polarity of the pulse applied first is negative, the slope of the electric field response curve is large before the polarity of the electric field is inverted and is gentle after the inversion, as indicated by b in FIG. .

A large change in the electric field response curve due to the difference in polarity of the applied pulse electric field as shown in FIG.
It is considered that this is caused by ethanol (or water contained in this) mixed in the polyimide film which is the inspection object. That is, it is considered that ethanol (or water contained therein) releases protons and acts as an electric field responsive impurity.

It should be noted that the electric field response curve when various known concentrations of ethanol are mixed in the polyimide film to be inspected in advance, and a calibration curve is prepared based on this curve to prepare an inspected object. The amount of ethanol mixed in can be quantified. When the electric field response curve of FIG. 3 was evaluated by such a method, it was found that the polyimide film as the inspection object contained ethanol at a molar ratio of 1000: 3.5.

Next, the non-polar solvent, cyclohexanone, was interposed between the polymer film 14 and the polyimide film 20, and the two were brought into close contact with each other, and the same inspection as above was performed. In this case, after the polymer film 14 and the polyimide film 20 are brought into close contact with each other, the movement of ethanol from the polyimide film 20 toward the polymer film 14 is stabilized in 45 seconds, and an electric field response curve similar to that in FIG. 3 is obtained. I found out that

Further, an inspection was conducted using a polymer film other than the above as the polymer film of the sensor head. That is, 10 g of polymethylmethacrylate having a molecular weight of 150,000 was dissolved in 150 cc of dry methylene chloride, and 30 g of 4-pentyl-4′-cyanobiphenyl as an electric field responsive low molecular weight compound was slowly added dropwise to this solution. The mixture was stirred as it was for 3 hours to obtain a uniform solution. This solution was concentrated to obtain a polymethylmethacrylate composition. 60 mg of this polymer composition
Was dissolved in 4 cc of THF (tetrahydrofuran), cast on a glass plate, and the solvent was evaporated to form a film. This polymer film was peeled off and cut into 2 cm × 3 cm.
When the film thickness of this polymer film was measured with a micro gauge, it was about 12 μm. A weight of 500 g was attached to the polymer film and stretched at 200 kg / cm ² . Before and after the stretching, the dichroic ratio of infrared absorption at 2230 cm ⁻¹ belonging to the cyano group of the low molecular weight compound dispersed in the polymer film was measured,
The orientation degree of the cyano group was determined. The ratio of the major axis to the minor axis of the cyano group was 1: 1 before stretching, while it was 2.8: 1 after stretching. From this result, it was found that the low molecular weight compound was uniaxially oriented in the stretched polymer film. It was found that an electric field response curve similar to that shown in FIG. 3 can be obtained even when the above-mentioned inspection is performed using such a polymer film.

In the above embodiment, as shown in FIG. 1, the polymer film 1 was previously formed on the ITO electrode 12 on the glass substrate 11.
Although the sensor head 10 with the fixed No. 4 was manufactured, the present invention is not limited to such a method, and various modifications can be considered. For example, the electrodes can be driven in a direction orthogonal to the surface of the object to be inspected, and the polymer film can be fed parallel to the surface of the object to be inspected to facilitate replacement of the polymer film and You may enable it to perform continuous inspection with respect to a to-be-inspected object. A modified example of the electric field responsive impurity inspection device according to the present invention having such a mechanism will be described with reference to FIGS. 4 and 5.

In the inspection apparatus of FIG. 4, the glass substrate 21
The sample on which the ITO electrode 22 and the inspection object 20 are formed is conveyed by the belt conveyor 101 and stopped at the position where the detection optical fiber 102 is installed. Two roller casings 103, 103 are provided above the belt conveyor 101, and a supply roller 104 and a take-up roller 10 are provided in the respective roller casings 103, 103 as means for feeding the polymer film 14.
5 are provided. The polymer film 14 is a supply roller 1.
04 and the take-up roller 105, and is arranged above the object 20 to be inspected in the middle thereof. Further, a hollow arm 106 for vertically driving the glass substrate 11 having the ITO electrode 12 formed above the polymer film 14.
Is provided. A light source side optical fiber 107 is inserted into the inside of the hollow arm 106, and the distal end of the optical fiber 107 is placed in contact with the glass substrate 11.

In the apparatus shown in FIG. 4, every time a predetermined inspection is completed, the substrate 11 on which the electrode 12 is formed is driven upward to separate it from the object 20 to be inspected, and the polymer film 14 is wound up for a new measurement. And the sample on which the object to be measured 20 is formed is conveyed, and then the substrate 11 on which the electrode 12 is formed is driven downward again to form a new polymer film 14 on the next object. The inspection is performed by closely contacting and fixing the inspection object 20. Therefore, the exchange of the polymer film 14 is facilitated, and the substrate 21 on which the inspection object 20 is formed is automatically conveyed, so that continuous inspection can be performed.

The inspection apparatus shown in FIG. 5 has a pair of upper and lower metal holders 201 and 202. Between the metal holders 201 and 202, the I on the glass substrate 21 is
The sample on which the TO electrode 22 and the inspection object 20 are formed is inserted and fixed by the screw 203. Similar to FIG. 4, the upper metal holder 201 is provided with two roller casings 103 and 103, and in each of the roller casings 103 and 103, a supply roller 104 for the polymer film 14 and a winding roller 105 are provided. The
The polymer film 14 is arranged above the object 20 to be inspected in the middle thereof. The ITO electrode 1 is provided above the polymer film 14.
A hollow arm 106 for vertically moving the glass substrate 11 on which 2 is formed is provided. A light source side optical fiber 107 is inserted into the inside of the hollow arm 106, and the distal end of the optical fiber 107 is placed in contact with the glass substrate 11.
In addition, the transparent window 20 is provided at the center of the lower metal holder 202.
4 are provided. And the optical fiber 10 for detection
The tip of 2 is arranged so as to face the transparent window 204.

In this device, the metal holders 201, 20
2, the feeding and winding mechanism of the polymer film 14, and the electrode 12
It is possible to handle the drive mechanism of the substrate 11 on which is formed integrally and portable.

In the above description, the case where the light transmitted through the polymer film 14 is detected has been described. For example, as shown in FIG. 6, the hollow arm 106 holding the substrate 11 on which the electrode 12 is formed serves as a light source. The side optical fiber 107 and the detection optical fiber 102 may be inserted so that the reflected light is detected after entering the polymer film 14.

[0044]

As described in detail above, according to the present invention, there is provided an inspection apparatus and an inspection method capable of detecting electric field responsive impurities mixed in an insulating film or a liquid crystal alignment film formed during the manufacture of a device. It is possible to provide a defective product that has been produced before the completion of the product, thereby eliminating waste of the manufacturing process.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an arrangement of electrodes, a polymer film, and an object to be inspected on a conductive substrate when inspecting an electric field responsive impurity according to the present invention.

FIG. 2 is a block diagram showing an example of an inspection apparatus for an electric field responsive impurity according to the present invention.

FIG. 3 is a characteristic diagram showing an electric field response curve measured using the electric field responsive impurity inspection device of the present invention.

FIG. 4 is a configuration diagram showing a part of an electric field responsive impurity inspection device according to another embodiment of the present invention.

FIG. 5 is a configuration diagram showing a part of an electric field responsive impurity inspection device according to another embodiment of the present invention.

FIG. 6 is a configuration diagram showing a part of an electric field responsive impurity inspection device according to still another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Pulse generator, 2 ... Infrared light source, 3 ... Polarizer, 4 ... Infrared detecting means (dispersive infrared spectrophotometer and M
CT detector), 5 ... preamplifier, 6 ... main amplifier, 7
… Digital sampling oscilloscope, 8… Computer, 10… Sensor head, 11… Glass substrate, 12
... ITO electrode, 13 ... Terminal, 14 ... Polymer film, 15 ... Stopper, 20 ... Polyimide film (inspection object), 21 ... Glass substrate, 22 ... ITO electrode, 101 ... Belt conveyor, 1
02 ... Detection optical fiber, 103 ... Roller casing, 104 ... Supply roller, 105 ... Winding roller, 106 ... Hollow arm, 107 ... Light source side optical fiber, 201, 202 ... Metal holder, 203 ... Screw, 2
04 ... Transparent window.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masayuki Oba 1 Komukai Toshiba-cho, Kouki-ku, Kawasaki-shi, Kanagawa Incorporated Toshiba Research and Development Center

Claims (5)

[Claims] 1. An apparatus for inspecting an electric field responsive impurity existing in an object to be inspected on a conductive substrate, wherein an electrode arranged to face the conductive substrate and uniaxially oriented electric field responsiveness. A polymer film containing a side chain or a low molecular weight compound, which is adhered between the electrode and the object to be inspected, and an alternating pulse electric field whose polarity reverses with time is applied between the electrode and the conductive substrate. Means, a light source for irradiating the polymer film between the electrode and the object to be inspected with light, and a photodetector for spectrally converting the light emitted from the light source and passing through the polymer film into an electric signal. An electric field responsive impurity inspecting device comprising: a means and a means for time-resolving the electric signal converted by the light detecting means and then taking out an integrated signal obtained by integrating the electric signal. 2. The electric field responsive impurity according to claim 1, wherein the means for extracting the integrated signal further comprises signal analysis means for calculating a slope of an electric field response curve showing a change with time of the integrated signal. Inspection device. 3. A means for driving the electrode in a direction perpendicular to the surface of the object to be inspected, and a means for feeding the polymer film parallel to the surface of the object to be inspected. The inspection apparatus for an electric field responsive impurity according to claim 1 or 2. 4. When inspecting an electric field responsive impurity present in an object to be inspected on a conductive substrate, the object to be inspected is
A uniaxially oriented polymer film containing side chains or low molecular weight compounds exhibiting electric field response and an electrode are pressed, and an alternating pulse electric field whose polarity is alternately inverted is applied between the electrode and the conductive substrate. While irradiating light, obtain the electric field response curve corresponding to the temporal change of the light intensity by measuring the light passing through the polymer film by time resolution, and within the time of each pulse width of the applied pulsed electric field. The method for inspecting an electric field responsive impurity in the object to be inspected according to the inclination of the electric field responsive curve according to 1. 5. Between the polymer film and the inspection object,
The method for inspecting electric field-responsive impurities according to claim 3, characterized in that a non-volatile solvent having no electric field response is interposed.