Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
  • G01N21/84—Systems specially adapted for particular applications
  • G01N21/88—Investigating the presence of flaws or contamination
  • G01N21/95—Investigating the presence of flaws or contamination characterised by the material or shape of the object to be examined
  • G01N21/956—Inspecting patterns on the surface of objects
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N23/00—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00
  • G01N23/22—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by measuring secondary emission from the material
  • G01N23/225—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by measuring secondary emission from the material using electron or ion
• • G—PHYSICS
  • G02—OPTICS
  • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
  • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
  • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
  • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
  • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
  • G02F1/136—Liquid crystal cells structurally associated with a semi-conducting layer or substrate, e.g. cells forming part of an integrated circuit
  • G02F1/1362—Active matrix addressed cells
  • G02F1/136254—Checking; Testing
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L22/00—Testing or measuring during manufacture or treatment; Reliability measurements, i.e. testing of parts without further processing to modify the parts as such; Structural arrangements therefor
  • H01L22/30—Structural arrangements specially adapted for testing or measuring during manufacture or treatment, or specially adapted for reliability measurements
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J2237/00—Discharge tubes exposing object to beam, e.g. for analysis treatment, etching, imaging
  • H01J2237/25—Tubes for localised analysis using electron or ion beams
  • H01J2237/2505—Tubes for localised analysis using electron or ion beams characterised by their application
  • H01J2237/2594—Measuring electric fields or potentials

Definitions

• the present invention relates to a TFT array substrate inspection apparatus that inspects an array formed on a substrate such as a TFT (eg, thin film transistor array) substrate.
• a TFT eg, thin film transistor array
• a TFT array substrate inspection device drives a TFT array substrate with a defect detection signal pattern and inspects the defect position, the type of defect, etc. by detecting the driving state at this time. Make a decision.
• the driving state of the TFT array can be detected by various methods such as a method of irradiating an electron beam or light and a method of detecting a signal flowing through the TFT.
• the TFT array substrate inspection device that detects the secondary electron intensity is based on the intensity of the secondary electrons generated by the TFT array substrate, based on the state of the ITO voltage generated by driving the TFT array substrate. Judgment is performed.
• the TFT array substrate inspection device that detects the reflected state of the irradiated light changes the refractive index of the electro-optic element by the electric field generated by the TFT array substrate, and this change in refractive index is reflected in the reflection angle of the irradiated light, etc. Judgment is made by detecting.
• Patent Document 1 Japanese Patent Laid-Open No. 2005-24378
• Patent Document 2 Japanese Patent Laid-Open No. 11-271800
• TFT arrays There are various types of defects in TFT arrays.
• the wiring to be connected There are open defects that become open states and short-circuit defects that cause short-circuits between wires to be insulated.
• defects in the TFT array can be easily determined based on the secondary electron intensity and the reflection angle of the irradiated light. Can be determined.
• the open defect includes not only a state in which the wiring is completely open but also a broken state in addition to a state in which the wiring is completely open.
• Such an incomplete defect has a problem that it is difficult to determine the defect by a conventional inspection method called weak leak.
• an object of the present invention is to provide a TFT array substrate inspection apparatus that can solve the above-described problems and can easily determine a defect called weak leak.
• the present invention provides a drive state detection device that detects a drive state of a transistor on a TFT array substrate, and a transistor property change device that changes the characteristics of the transistors constituting the TFT array substrate.
• the TFT array substrate inspection apparatus includes: an inspection apparatus that inspects the driving state of the TFT array substrate in a state where the characteristics of the transistor are changed from an output of the driving state detection apparatus.
• the TFT array inspection apparatus of the present invention it is possible to easily determine a defect called weak leak.
• FIG. 1 is a diagram for explaining a configuration example of a first embodiment of the present invention.
• FIG. 2 is a diagram for explaining a configuration example of a secondary electron detector of the present invention.
• FIG. 3 is a diagram showing the relationship between the energy of an electron and the distance traveled by the electron in aluminum.
• FIG. 4 shows the transmittance of visible light depending on the film thickness of aluminum.
• FIG. 5 is a diagram for explaining the film thickness of aluminum and the transmission wavelength range of electrons and visible light.
• FIG. 6 is a diagram for explaining a configuration example of a second embodiment of the present invention.
• FIG. 7 is a diagram for explaining a configuration example of a third embodiment of the present invention.
• FIG. 8 is a diagram for explaining a configuration example of a fourth embodiment of the present invention. Explanation of symbols
• Electron beam source 12 Electron beam source
• Electromagnetic wave irradiation device 24...
• Electro-optic element 29 Electro-optic element
• Electro-optic element 39 Electro-optic element
• the first and second embodiments of the TFT array inspection apparatus of the present invention are forms for detecting secondary electrons obtained by irradiating an electron beam.
• the third and fourth embodiments of the TFT array inspection apparatus of the present invention are forms for detecting an optical change of light by an electro-optic element.
• the first and third embodiments are configured to change the transistor characteristics of silicon by irradiating the TFT array substrate 10 with electromagnetic waves such as visible light.
• the transistor characteristics of silicon are changed by heating the TFT array substrate 10 with a heater (heating means).
• a TFT array substrate inspection apparatus 1 includes an electron beam source 2 that irradiates an electron beam 3 toward the TFT array substrate 10 and secondary electrons 8 emitted from the TFT array substrate 10 by the irradiation of the electron beam 3. Detection of TFT array defects based on secondary electron detector (secondary electron detection means) 5 that detects the transistor drive state by detection and secondary electron intensity signal detected by secondary electron detector 5 And an inspection device 6 for performing the above.
• secondary electron detector secondary electron detection means
• the TFT array substrate inspection apparatus 1 further includes a transistor characteristic changing device that changes the transistor characteristics of the TFT array substrate 10 as transistor characteristic changing means.
• a visible light irradiation device (visible light irradiation means) 4 is provided as the transistor characteristic changing means.
• the visible light irradiation device 4 irradiates the visible light 7 toward the electron beam irradiation region where the electron beam 3 irradiates the TFT array substrate 10.
• the inspection device 6 inspects the TFT array substrate 10 for defects or the like in a state where the transistor characteristics are changed by the visible light irradiation device 4 as the transistor characteristic changing device.
• the transistor characteristics of silicon included in the TFT array substrate 10 change depending on the irradiated visible light 7.
• the visible light irradiation device 4 can use a white light in addition to the LED. Since white lamps have a wide wavelength range, a wavelength filter can be used together in consideration of wavelength dependency depending on the type of defect. In the case of a configuration using LEDs, the wavelength can be selected according to the wavelength dependency of the defect.
• the drain current versus gate voltage characteristics (transfer characteristics) of an a-Si (amorphous silicon) TFT have a ratio of on-state current to off-state current of 7 digits or more.
• a-Si has a high photoconductivity, a large optical electric field effect appears when irradiated with light.
• the off-state current increases by two orders of magnitude or more.
• the TFT array substrate inspection apparatus 1 of the present invention enhances the leak by increasing the weak off-current leak caused by the defect due to the optical electric field effect by this light irradiation, and facilitates the defect inspection.
• the TFT array substrate inspection device of the present invention converts the secondary electrons emitted in accordance with the voltage to a secondary electron detector. Detect with 5. The intensity of the detected secondary electrons is emphasized and detected in the defective part and the normal part, so even incomplete defects called weak leaks are well identified for defect inspection. It can be carried out.
• the secondary electron detector 5 is reflected by the secondary electron 8 directly from the visible light irradiation device 4 or by reflection on the TFT array substrate 10 or a wall surface in the inspection device. Visible light 7 may enter.
• a secondary electron detector having a function such as SEM a scintillator that converts an electron into light as a secondary electron detector, and a photoelectric converter such as a photomultiplier tube that converts light into an electric signal ( Since it is a configuration using a photoelectric conversion means), it reacts also with light other than secondary electrons that are detection targets. Therefore, in the TFT array substrate inspection apparatus of the present invention, when light is irradiated to the TFT array substrate 10 to be inspected, this light is mixed as a noise component during secondary electron detection, which hinders normal secondary electron detection. Will occur.
• the surface of the scintillator of the secondary electron detector 5 is coated with aluminum, light is shielded by the aluminum, and only the secondary electrons to be detected are penetrated (transmitted).
• FIG. 2 is a diagram for explaining a configuration example of the secondary electron detector 5.
• the secondary electron detector 5 has a glass substrate 5b on the light incident side of the photomultiplier tube 5a.
• a scintillator material 5c such as Csl is provided on the outer surface of the glass substrate 5b.
• the configuration including the photomultiplier tube 5a, the glass substrate 5b, and the scintillator material 5c is the same as that of a normal secondary electron detector.
• the secondary electron detector 5 has an aluminum thin film 5d deposited on the surface side of the scintillator material 5c by sputtering or the like.
• a semiconductor photoelectric conversion element such as a CCD image sensor or a MOS image sensor may be used in addition to the photomultiplier tube 5a.
• FIGS. Figure 3 This shows the relationship between the energy of electrons and the distance traveled by the electrons in aluminum.
• the energy of the secondary electrons is a force of several eV. Since a positive voltage of several kV to 10 kV is applied to the scintillator, the secondary electrons are accelerated and incident on the scintillator at a high voltage energy. To do.
• the moving distance of electrons having an energy of 10 eV in aluminum is 0.16 mg / cm 2 .
• Fig. 5 shows the relationship between the aluminum film thickness described above
• Fig. 5 (a) shows the boundary between the visible light transmission and non-transmission aluminum film thickness
• Fig. 5 (b) shows the secondary electrons
• Fig. 5 (c) shows the boundary between the transparent and non-transmissive aluminum film thickness.
• Figure 5 (c) shows the range of the aluminum film thickness that allows the passage of secondary electrons without passing visible light, combining Figure 5 (a) and Figure 5 (b). Show. Therefore, by setting the aluminum film thickness in the range of 400A to 6000A, it is possible to shield visible light and allow secondary electrons to pass through the scintillator.
• the TFT array substrate inspection apparatus 11 includes an electron beam source 12 that irradiates the electron beam 13 toward the TFT array substrate 10 and secondary electrons emitted from the TFT array substrate 10 by the irradiation of the electron beam 13.
• the heater (heating device which is a heating means) 14 is provided. The heater 14 heats the TFT array substrate 10 to a predetermined temperature.
• a sheath heater or a lamp can be used for the heater 14.
• the configuration in which the TFT array substrate 10 is heated to a predetermined temperature and the above-described configuration of light irradiation can be used in combination.
• the heating temperature can be set according to the wavelength dependency of the defect.
• the TFT array substrate inspection apparatus 21 includes a light source 22 that emits light 23 toward the TFT array substrate 10, and an electro-optic element 29 that is disposed with a slight gap between the TFT array substrate 10 and And an optical detector 25 for detecting the light 28 reflected by the reflecting surface of the electro-optic element 29.
• the TFT array substrate inspection apparatus 21 includes an inspection apparatus 26 that inspects defects of the TFT array based on the light intensity signal detected by the photodetector 25, and a transistor characteristic change apparatus that is an electromagnetic wave irradiation means.
• an electromagnetic wave irradiation device electromagagnetic wave irradiation means
• the electromagnetic wave irradiation device 24 can be a visible light irradiation device (visible light irradiation means) such as a white light or LED shown in the first embodiment.
• the electromagnetic wave irradiation device 24 irradiates an electromagnetic wave 27 such as visible light toward an irradiation region where the light 23 irradiates the TFT array substrate 10.
• the transistor characteristics of silicon included in the TFT array substrate 10 vary depending on the electromagnetic wave 27 irradiated.
• the voltage distribution on the TFT array substrate 10 changes, and the electric field applied to the electro-optic element 29 also changes.
• the electric field applied to the electro-optic element 29 changes, the refractive index of the electro-optic element 29 changes, and the emission direction of the light 23 reflected by the reflecting surface of the electro-optic element 29 changes. This change in the emission direction of the light 23 is detected as a change in the detection intensity of the light detector 25, and thus a defect inspection can be performed.
• the voltage distribution shift due to the defect is emphasized, and the defect can be easily identified.
• a TFT array substrate inspection apparatus 31 includes a light source 32 that emits light 33 toward the TFT array substrate 10 and an electro-optic element 39 that is disposed with a slight gap between the TFT array substrate 10 and The light detector 35 detects the light 38 reflected by the reflecting surface of the electro-optic element 39.
• the TFT array substrate inspection device 31 is used to detect the intensity of light detected by the photodetector 35.
• the inspection device 36 for inspecting the TFT array for defects and the like, and a heater (heating device as a heating means) 34 as a transistor characteristic changing device are provided.
• the heater 34 heats the TFT array substrate 10 to a predetermined temperature. For this reason, a sheathed heater or a lamp can be used for the heater 34.
• the transistor characteristics of silicon included in the TFT array substrate 10 vary depending on the heating temperature.
• the voltage distribution on the TFT array substrate 10 changes and the electric field applied to the electro-optic element 39 also changes, and the refractive index of the electro-optic element 39 changes due to the electric field,
• the emission direction of the light 38 reflected by the reflecting surface of the electro-optic element 39 changes. This change in the emission direction of the light 38 is detected as a change in the detection intensity of the light detector 35, whereby a defect inspection can be performed.
• the TFT array substrate 10 is heated to a high temperature by the heater 34, the deviation of the voltage distribution due to the defect is emphasized, and the defect can be easily identified.
• the TFT array substrate inspection apparatus is a drive state detection device (for example, the electron beam source 2 and the secondary) that detects the drive state of the transistors of the TFT array substrate 10.
• Means comprising an electron detector 5, or means comprising an electron beam source 12 and a secondary electron detector 15, or means comprising a light source 22 and a light detector 25, or means comprising a light source 32 and a light detector 35).
• the TFT array substrate inspection apparatus includes a transistor characteristic changing device (visible light irradiation device 4, heater 14, electromagnetic wave irradiation device 24, heater 34) that changes the characteristics of the transistors constituting the TFT array substrate 10. Yes.
• the TFT array substrate inspection device includes an inspection device (6, 16, 26, 36) for inspecting the driving state of the TFT array substrate 10 in a state where the characteristics of the transistor have changed from the output of the driving state detection device. ing.
• the drive state detection device of the TFT array substrate inspection device includes a beam irradiation device (electron beam sources 2 and 12) for irradiating the TFT array substrate 10 with an electron beam, The intensity of secondary electrons generated by the electron beam irradiation is detected and the detection is performed.
• a secondary electron detector (5, 15) is input to the dredge device (6, 16).
• the TFT array inspection apparatus having this configuration, it is possible to easily determine a defect called weak leak by detecting the intensity of secondary electrons generated from the TFT array substrate 10 by irradiation of an electron beam. Can do.
• the drive state detection device of the TFT array substrate inspection device includes an electro-optic element (29, 39) disposed above the TFT array substrate 10 with a gap therebetween.
• a light irradiating device (light sources 2 32) for irradiating light onto the electro-optic element (29, 39) from above; and the light reflected by the reflective film of the electro-optic element (29, 39) is a TFT array
• a photodetector 25, 35 for detecting an optical change received by an electric field between the substrate 10 and the electro-optic element (29, 39) and inputting a detection output to the inspection device (26, 36); Yes.
• the TFT array inspection apparatus having this configuration, it is possible to easily determine a defect called weak leak by detecting an optical change of light reflected by the reflection film of the electro-optic element (29, 39). It can be.
• the transistor characteristics of silicon constituting the TFT array substrate 10 are changed from the state when the normal TFT array substrate 10 is driven, and this transistor By inspecting the TFT array substrate 10 with the characteristics changed, it is possible to easily determine a defect called weak leak.
• silicon when silicon is irradiated with electromagnetic waves or heat is applied, the transistor characteristics of silicon change from the normal state.
• silicon has a characteristic that the optical electric field effect is large, and the off-current increases when irradiated with light in the visible light region.
• this property is used to increase off-current by irradiating light in the visible light region with respect to defects that cause weak off-current leakage in a state where light in the visible light region is not irradiated. This enhances the leak. As a result, it is possible to easily detect a defect called a weak leak.
• the TFT array substrate inspection apparatus is a transistor characteristic changing apparatus that changes the transistor characteristics of silicon constituting the TFT array substrate 10 in the TFT array substrate inspection apparatus that inspects the TFT array substrate 10. It is set as the structure provided with.
• This transistor characteristic change device changes the transistor characteristics of the silicon that constitutes the TFT array substrate 10.
• the TFT array substrate 10 in which the transistor characteristics are changed is inspected.
• the first aspect of the TFT array substrate inspection apparatus irradiates the TFT array substrate 10 with an electron beam, and determines the intensity of secondary electrons generated by the electron beam irradiation as a secondary electron detector.
• the TFT array substrate inspection device that inspects the TFT array substrate 10 with this secondary electron intensity is equipped with a transistor characteristic changing device that changes the transistor characteristics of the silicon that constitutes the TFT array substrate 10, and the transistor characteristics are The intensity of the secondary electrons obtained by irradiating the electron beam to the TFT array substrate 10 in the changed state is detected.
• an electromagnetic wave irradiation device that irradiates the TFT array substrate 10 with electromagnetic waves can be used.
• the electromagnetic wave irradiation device changes the transistor characteristics to silicon constituting the TFT array substrate 10 by irradiating the TFT array substrate 10 with electromagnetic waves, and detects the intensity of secondary electrons generated from the TFT array substrate 10 at this time.
• the electromagnetic wave irradiation device is a visible light irradiation device that emits light in the visible light region.
• the off-state current of the silicon constituting the TFT array substrate 10 is increased, and the secondary electron intensity generated from the TFT array substrate 10 is detected.
• the electromagnetic wave to be irradiated infrared light, ultraviolet light, radiation, or the like can be used in addition to light in the visible light region.
• a heater that raises the temperature of the TFT array substrate 10 can be used.
• the heater changes the transistor characteristics to silicon constituting the TFT array substrate 10 by heating the TFT array substrate 10, and detects the secondary electron intensity generated from the TFT array substrate 10 at this time.
• a second aspect of the TFT array substrate inspection apparatus of the present invention is to detect the reflection of the irradiated light beam, and an electro-optic element is disposed above the TFT array substrate 10 with a gap therebetween.
• TFT array substrate by irradiating light from the top of the electro-optic element and detecting the optical change received by the light reflected by the reflective film of the electro-optic element by the electric field between the TFT array substrate 10 and the electro-optic element
• the TFT array substrate inspection device that inspects 10 includes a transistor property change device that changes the transistor characteristics of the silicon that constitutes the TFT array substrate 10, and the TFT array substrate 10 in a state in which the transistor properties have changed and the electric light An optical change of light received by an electric field between the optical elements is detected.
• the first embodiment of the transistor characteristic changing device can be an electromagnetic wave irradiation device that irradiates the TFT array substrate 10 with electromagnetic waves.
• the transistor characteristics are changed to the silicon constituting the TFT array substrate 10 and received by the electric field between the TFT array substrate 10 and the electro-optic element in this state Detect optical changes in light.
• the electromagnetic wave irradiation device can be a visible light irradiation device that irradiates light in the visible light region.
• the optical change of the light received by the electric field between the TFT array substrate 10 irradiated with visible light and the electro-optic element is detected.
• infrared light, ultraviolet light, radiation, or the like can be used as the electromagnetic wave to be irradiated.
• the second embodiment of the transistor characteristic changing device may be a heater that raises the temperature of the TFT array substrate 10.
• the transistor characteristics of the silicon constituting the TFT array substrate 10 are changed, and the optical light received by the electric field between the TFT array substrate 10 and the electro-optic element due to this state is changed. Detect changes.
• the array inspection of the present invention can be applied to inspection of liquid crystal array substrates and organic EL array substrates.

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• 2006
  • 2006-04-20 JP JP2007528192A patent/JPWO2006120861A1/ja active Pending
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  • 2006-04-20 WO PCT/JP2006/308337 patent/WO2006120861A1/ja active Application Filing
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