JP2014063943A - Method for inspecting polycrystalline silicon film and apparatus therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for inspecting a polycrystalline silicon film and an apparatus therefor, in which an optical system is provided which can efficiently detect diffraction light generated by projection of the surface of the polycrystalline silicon film.SOLUTION: A polycrystalline silicon film is irradiated with light at a light irradiation angle within a range of a predetermined light irradiation angle with respect to the normal direction in the annealing direction of the polycrystalline silicon film formed on the surface of a glass substrate, the primary diffraction light generated from the surface of the polycrystalline silicon film irradiated with light is detected at a predetermined light receiving angle, and a state of the polycrystalline silicon film is inspected on the basis of intensity of the primary diffraction light obtained by inspection.

Description

  The present invention relates to a method and an apparatus for inspecting a state of a polycrystalline silicon film crystal obtained by polycrystallizing an amorphous silicon film formed on a substrate by laser annealing.

Thin film transistors (TFTs) used for liquid crystal display elements and organic EL elements are polycrystallized by annealing a part of amorphous silicon formed on a substrate at low temperature with an excimer laser in order to ensure high-speed operation. Formed in the region.

As described above, when a part of amorphous silicon is annealed at a low temperature with an excimer laser to be polycrystallized, it is required to uniformly polycrystallize. In practice, however, the crystal varies due to the influence of the fluctuation of the laser light source. May occur.

Therefore, as a method of monitoring the occurrence state of the variation of the silicon crystal, Patent Document 1 discloses that the semiconductor film is irradiated with a pulse laser to perform laser annealing and the laser irradiation region is irradiated with inspection light, and the irradiated inspection light is irradiated. It is described that the reflected light from the substrate is detected and the state of crystallization of the semiconductor film is confirmed from the intensity change of the reflected light.

Further, Patent Document 2 discloses that a region where amorphous silicon formed on a substrate is changed to polycrystalline silicon by excimer laser annealing is irradiated with visible light from a direction of 10 to 85 degrees with respect to the substrate surface. In addition, it is described that reflected light is detected by a camera that is grounded in the same angle range as that of irradiation, and the arrangement state of protrusions on the crystal surface is inspected from the change of the reflected light.

Further, in Patent Document 3, a polycrystalline silicon film formed by irradiating an excimer laser on an amorphous silicon film is irradiated with inspection light, and diffracted light from the polycrystalline silicon film is monitored by a diffracted light detector. By utilizing the fact that the intensity of diffracted light generated from a region with a regular fine concavo-convex structure with high crystallinity in a crystalline silicon film is higher than the intensity of diffracted / scattered light from a region with low crystallinity, polycrystalline silicon It is described to inspect the condition of the membrane.

JP 2002-305146 A JP 2006-19408 A JP 2001-308209 A

Thin film transistors (TFTs) used for liquid crystal display elements, organic EL elements, and the like are often manufactured by irradiating a part of an amorphous silicon thin film formed on a substrate with an excimer laser and annealing in order to ensure high-speed operation. It is formed in the crystallized region.
It is known that the surface of a polycrystalline silicon film (polysilicon film) formed by irradiating with this excimer laser is annealed with a period having fine irregularities. These fine protrusions reflect the degree of crystallinity of the polycrystalline silicon film, and there are fine irregularities on the surface of the polycrystalline silicon film having a uniform crystal state (with a uniform polycrystalline grain size). It is known that fine irregularities are irregularly formed on the surface of a polycrystalline silicon film which is periodically formed with a certain regularity and whose crystal state uniformity is low (polycrystalline grain size is not uniform). .

  Therefore, there is a need to reliably detect and inspect irregularities of protrusions on the surface of the polycrystalline silicon film, that is, unevenness in the polycrystalline grain size of the polycrystalline silicon film.

  In response to this requirement, Patent Document 1 describes that a laser-annealed region is irradiated with irradiation light, and the state of crystallization of the semiconductor film is confirmed from a change in the intensity of reflected light that reflects the crystal state. ing. However, there is no description about detecting diffracted light in which the crystal state is reflected, and there is no description about how to detect diffracted light with high sensitivity.

  In Patent Document 2, visible light is irradiated from a direction of 10 to 85 degrees with respect to the substrate surface to a region changed to polycrystalline silicon, and reflected light is detected by a camera grounded in the same angle range as the irradiation. The inspection is described. However, as in Patent Document 1, there is no description about detecting diffracted light generated by protrusions on the surface of the polycrystalline silicon film, and there is no description about how to detect the diffracted light with high sensitivity. .

  Further, Patent Document 3 describes detecting diffracted light generated by protrusions on the surface of a polycrystalline silicon film formed by laser annealing. However, the intensity level of the diffracted light detected by the diffracted light detector is monitored to inspect the state of the polycrystalline silicon film, and the optical system describes how to detect the diffracted light with high sensitivity. Nor.

  Accordingly, it is an object of the present invention to provide a polycrystalline silicon film inspection method and an apparatus having an optical system that can efficiently detect first-order diffracted light generated by protrusions on the surface of the polycrystalline silicon film.

In order to achieve the above object, the present invention has at least the following features.
The present invention relates to an inspection stage for holding a formation substrate having a polycrystalline silicon film formed on the surface of a glass substrate, and light within a predetermined light irradiation angle range with respect to the normal direction of the annealing direction of the polycrystalline silicon film. Irradiation means for irradiating light to the polycrystalline silicon film at an irradiation angle, and detecting first-order diffracted light generated from the surface of the polycrystalline silicon film irradiated with the light at a predetermined light receiving angle with respect to the normal direction An inspection optical system, and an inspection unit that inspects the state of the polycrystalline silicon film based on the intensity of the first-order diffracted light obtained by the inspection optical system. .

  The present invention also irradiates the polycrystalline silicon film with light having a light irradiation angle within a predetermined light irradiation angle range with respect to the normal direction of the annealing direction of the polycrystalline silicon film formed on the glass substrate surface. Detecting the first-order diffracted light generated from the surface of the polycrystalline silicon film irradiated with the light at a predetermined light receiving angle, and based on the intensity of the first-order diffracted light obtained by the detection, the polycrystalline silicon It is characterized by inspecting the state of the film.

  Further, the light irradiation angle range may be within ± 30 degrees, and in particular, the light irradiation angle and the light receiving angle may both be zero degrees with respect to the normal direction.

  According to the present invention, the first-order diffracted light generated by the projections on the surface of the polycrystalline silicon film is generated by the optical system that irradiates and receives the light at a predetermined angle with respect to the annealing direction for annealing the polycrystalline silicon film. An inspection method and apparatus for a polycrystalline silicon film that can be detected efficiently can be provided.

It is a graph which shows the relationship between the irradiation energy of an excimer laser, and the crystal grain diameter of a polycrystalline silicon film. It is the top view of the polycrystalline silicon film which showed typically the state of the polycrystalline silicon film formed when the irradiation energy of an excimer laser is small. It is the top view of the polycrystalline silicon film which showed typically the state of the polycrystalline silicon film formed when the irradiation energy of an excimer laser is appropriate. It is the top view of the polycrystalline silicon film which showed typically the state of the polycrystalline silicon film formed when the irradiation energy of an excimer laser was too large. It is a block diagram which shows the schematic structure of the optical system which irradiates illumination light to the board | substrate with which the polycrystalline-silicon film was formed, and detects 1st-order diffracted light. It is the figure which showed the crystal grain boundary by the luminance image of the polycrystalline-silicon film with which the particle size of the crystal | crystallization shown in FIG. 2B was comparatively uniform. 7B is a graph showing the maximum first-order analysis light intensity with respect to the light irradiation angle α of the inspection optical system with respect to the annealing direction shown in FIG. 6 in the same sample having a uniform particle size as shown in FIG. 2B. It is a figure which shows the test | inspection optical system of the test | inspection unit which detects the primary analysis light intensity with respect to the annealing direction by an excimer laser. It is a figure which shows the structure of the whole polycrystalline silicon film test | inspection apparatus of the glass substrate for liquid crystal display panels which is 1st Example of this invention. It is a figure which shows the structure of the test | inspection unit and test | inspection data processing / control unit in the test | inspection part of Example 1. FIG. It is a flowchart which shows the imaging sequence which images a board | substrate in order to test | inspect the state of the crystal | crystallization of a polycrystalline silicon film. It is a figure which shows the image processing sequence which processes the digital image obtained by the imaging sequence. It is a figure which shows the structure of the whole polycrystalline silicon film test | inspection apparatus which is the 2nd Example of this invention. It is a figure which shows the structure of the annealing direction detection means and process turning control part of 2nd Example of this invention. It is a figure which shows the crystalline silicon film formation apparatus which is a 4th Example of this invention which has a polycrystalline silicon film test | inspection apparatus which is the 1st Example of this invention.

As an embodiment of the present invention, an example applied to an apparatus for inspecting a polycrystalline silicon thin film formed on a glass substrate for a liquid crystal display panel will be described.

  A glass substrate for a liquid crystal display panel to be inspected (hereinafter referred to as a substrate) has an amorphous silicon thin film formed on the substrate. By irradiating the excimer laser to a part of the thin film of the amorphous silicon and scanning, the portion of the amorphous silicon irradiated with the excimer laser is heated and melted (annealed), and after the excimer laser is scanned, The molten amorphous silicon is gradually cooled to be polycrystallized, and crystals grow in the state of polycrystalline silicon. A substrate on which an amorphous silicon thin film is formed is referred to as a formation substrate.

  The graph of FIG. 1 shows an approximate relationship between the irradiation energy of the excimer laser when the amorphous silicon is annealed by the excimer laser and the crystal grain size of the polycrystalline silicon. When the excimer laser irradiation energy during annealing is increased, the crystal grain size of polycrystalline silicon also increases.

  When the irradiation energy of the excimer laser at the time of annealing is weak (range A in FIG. 1), as shown in FIG. 2A, the grain size of the crystal 201 of the polycrystalline silicon film is small and the variation is large. . In such a crystalline state, stable characteristics cannot be obtained as a polycrystalline silicon film.

  On the other hand, when the energy of the excimer laser at the time of annealing is set to an appropriate range (range B in FIG. 1), a polycrystalline silicon film having a relatively uniform grain size of crystals 202 is formed as shown in FIG. 2B. The Thus, when the film is obtained in a state where the crystal grain sizes are uniform, stable characteristics as a polycrystalline silicon film can be obtained.

  When the irradiation energy of the excimer laser at the time of annealing is further increased (range C in FIG. 1), the crystal grain size of polycrystalline silicon becomes larger. However, when the irradiation energy is increased, the variation in the growth rate of crystal grains increases, and as shown in FIG. 2C, the crystal 203 has a large variation in grain size, resulting in stable characteristics as a polycrystalline silicon film. Can't get.

  Accordingly, it is important to stably maintain the energy of the excimer laser irradiated to the amorphous silicon within the range of B in FIG.

  On the other hand, as described in Patent Document 3, it is known that a minute projection is formed at a crystal grain boundary in a polycrystalline silicon film formed by annealing amorphous silicon with an excimer laser.

  When the glass substrate 303 on which such a polycrystalline silicon film 301 is formed is irradiated with light from a light source 310 disposed on the back side as shown in FIG. Diffracted light is generated on the surface side of the glass substrate 303 by the scattered light. The position where the diffracted light is generated varies depending on the wavelength of light emitted from the light source 310 and the pitch of the minute protrusions 302 formed at the crystal grain boundaries of the polycrystalline silicon film 301.

In the configuration shown in FIG. 3, the wavelength of the light irradiating the formation substrate 300 is λ, the pitch of the minute protrusions 302 formed at the crystal grain boundaries of the polycrystalline silicon film 301 is P, and the light irradiating the formation substrate 300 is irradiated. Assuming that the angle from the normal direction of the formation substrate 300 is θi and the angle of the first-order diffracted light generated from the formation substrate 300 from the normal direction of the substrate 300 is θo,
sinθi + sinθo = λ / P (Equation 1)
This relationship holds.

  Therefore, it is generated by light having a wavelength λ emitted from the light source 310 and irradiated from the direction of the angle θi in a state where minute protrusions 302 are formed at a predetermined pitch P in the crystal grain boundary of the polycrystalline silicon film 301. By observing the first-order diffracted light with the imaging camera 320 disposed at the angle θo, the first-order diffracted light from the polycrystalline silicon film 301 can be observed.

  On the other hand, the crystal grain size of the polycrystalline silicon film 301 depends on the excimer laser irradiation energy at the time of annealing as shown in FIG. 1, and in the region where the excimer laser irradiation energy of FIG. The crystal grain size increases as the excimer laser irradiation energy increases. Therefore, when the irradiation energy of the excimer laser fluctuates during annealing, the crystal grain size of the polycrystalline silicon film 301 changes and the variation in grain size increases as described with reference to FIGS. 2A to 2C. When light is emitted from the light source 310 to the polycrystalline silicon film 301 in which the crystal grain size has changed and the pitch variation of the minute protrusions 302 has increased, the progression of the first-order diffracted light generated from the polycrystalline silicon film 301 When the direction changes, the intensity mainly decreases, so the luminance of the first-order diffracted light detected by the imaging camera 320 decreases.

  FIG. 4 is a diagram showing a crystal grain boundary based on a luminance image of a polycrystalline silicon film in which the crystal 202 shown in FIG. 2B has a relatively uniform grain size. White circles and broken black dots indicate areas with high luminance, and lines connecting areas with high luminance form crystal grain boundaries. As understood from comparison with FIG. 2B, the crystal grain boundary is formed along the protruding portion 302. P represents the pitch of the particle diameter.

  FIG. 5 is a graph showing the maximum first-order diffracted light intensity with respect to the light irradiation angle α of the inspection optical system with respect to the annealing direction shown in FIG. 6 in the same sample having a uniform particle size as shown in FIG. 2B. FIG. 6 is a diagram showing an inspection optical system of an inspection unit that detects the intensity of the first-order diffraction light in the annealing direction by excimer laser ELA (exicimer laser annealing).

  The inspection optical system 330 has the configuration shown in FIG. 3, and the light source 310 that is an irradiation unit and the imaging camera 320 that is an imaging unit have a light irradiation angle α (degrees) with respect to the normal direction of the annealing direction. Are arranged with a light receiving angle β (degrees).

  In the result shown in FIG. 4, the first-order diffracted light intensity seems to have no apparent relationship with the annealing direction, but as shown in the result of FIG. 5, the light irradiation angle α of the detection optical system 330 with respect to the annealing direction. (See Fig. 6).

  The optimum light irradiation angle α for detecting the first-order analysis light intensity is the normal direction to the annealing direction, that is, 90 degrees. The allowable range (αmin, αmax) of the light irradiation angle α naturally depends on the intensity of the first-order analysis light that can detect the particle size. The primary analysis intensity at which the particle size can be detected is defined as the maximum (or average) primary analysis intensity, and the maximum or average primary analysis intensity depends on the irradiation energy of the excimer laser. Therefore, although the permissible range cannot be generally described, it was possible at (−30 degrees, 30 degrees), for example. In addition, the light irradiation angle α and the detection angle β are not necessarily symmetrical with respect to the normal direction, but the detection angle β is a light beam so that at least a primary diffraction intensity with a predetermined particle diameter can be obtained. It is set according to the irradiation angle α.

  In the present invention, when detecting the primary analysis light intensity, a polycrystal to be inspected by setting the inspection optical system so that the light irradiation angle is within the light irradiation angle range which is the allowable range with respect to the annealing direction. A silicon film inspection method and apparatus are provided. In particular, it is preferable to set the light irradiation angle and the detection angle in the normal direction (90 degrees) with respect to the annealing direction.

  Embodiments of the present invention will be described below with reference to the drawings.

Example 1
FIG. 7 shows the entire configuration of a polycrystalline silicon film inspection apparatus 600 for a glass substrate for a liquid crystal display panel according to the first embodiment of the present invention.

  The polycrystalline silicon film inspection apparatus 600 includes a substrate loading unit 610, an inspection unit 620, a substrate unloading unit 630, an inspection unit data processing / control unit 640, and an overall control unit 650.

  The formation substrate 300 of the glass substrate for a liquid crystal display panel to be inspected is scanned by irradiating a part of the region with an excimer laser beam on the amorphous silicon thin film formed on the glass substrate 303 immediately before the main inspection step. Then, it is heated and annealed. The heated region is annealed and crystallized from an amorphous state, and becomes a polycrystalline silicon film 301 as shown in FIG. The polycrystalline silicon film inspection apparatus 600 images the surface of the formation substrate 300 and examines whether or not the polycrystalline silicon film 301 is normally formed.

  The formation substrate 300 to be inspected is set on the substrate load unit 610 by a conveying means (not shown) so that the annealing direction is a predetermined angle with respect to the detection optical system as shown in FIG. The formation substrate 300 set on the substrate load unit 610 is transported to the inspection unit 620 by a transport unit (not shown) controlled by the overall control unit 650. The inspection unit 620 includes an inspection unit 621 and inspects the state of the polycrystalline silicon film formed on the surface of the formation substrate 300 under the control of the inspection data processing / control unit 640. The data detected by the inspection unit 621 is processed by the inspection data processing / control unit 640, and the state of the polycrystalline silicon film 301 formed on the surface of the formation substrate 300 is evaluated.

  The formed substrate 300 that has been inspected is transported from the inspection unit 620 to the unload unit 630 by a transport unit (not shown) controlled by the overall control unit 650 and taken out from the inspection device 600 by a handling unit (not shown). FIG. 7 shows a configuration in which one inspection unit 621 is provided in the inspection unit 620. However, the size of the formation substrate 300 to be inspected and the area and arrangement of the formed polycrystalline silicon film 301 are shown. Depending on the number, two units or three or more units may be used.

  FIG. 8 is a diagram illustrating the configuration of the inspection unit 621 and the inspection data processing / control unit 640 in the inspection unit 620.

  In this embodiment, the illumination optical system is arranged on the front side of the formation substrate 300, and the detection system is arranged on the back side of the formation substrate, so that the degree of freedom in arrangement of each device is increased.

  The inspection unit 621 includes an inspection optical system 730 including an illumination optical system 710 that is an illumination unit and an imaging camera 720 that is an imaging unit, and an inspection stage unit 740. The inspection optical system 730 is set so that α = 90 degrees in FIG.

  The illumination optical system 710 is a light source 711 that emits light having a wavelength λ, a light that has a wavelength λ emitted from the light source 711, is formed into a linear light, and is held by the inspection stage unit 741. A cylindrical lens 712 for irradiating the substrate 300 is provided.

  The light having the wavelength λ of the inspection light is blue light or green light having a wavelength in the range of 300 nm to 600 nm, and a laser diode or LED (Light Emitting Diode) is used as the light source 711. In this embodiment, an excimer laser ELA is used.

  The cylindrical lens 712 condenses the illumination light beam in one direction so that the light of the wavelength λ emitted from the light source 711 can be efficiently illuminated in accordance with the size of the inspection region on the formation substrate 300 and has a cross-sectional shape. It is formed into a linear shape that is long in one direction. By irradiating the formation substrate 300 with light condensed in one direction by the cylindrical lens 712 from an angle direction θ1 with respect to the normal direction, the amount of illumination light in the inspection region on the formation substrate 300 increases, and the imaging optical system At 720, an image with high contrast can be detected.

  The imaging camera 720 captures an image of first-order diffracted light generated from the formation substrate 300 irradiated with illumination light. The imaging camera 720 is installed in an angle direction inclined by θ2 with respect to the normal direction of the formation substrate 300. In the imaging camera 720, the light having the wavelength λ formed by the cylindrical lens 712 has a pitch P (see FIG. 5) at the crystal grain boundary of the polycrystalline silicon film 301 existing in a long region in one direction of the surface of the illuminated formation substrate 300. 4), an optical image is picked up by the first-order diffracted light from the minute protrusion 302 formed in step 4).

  The imaging camera 720 is a one-dimensional CCD (electrically coupled device) image sensor (not shown) or a two-dimensional CCD image sensor arranged in accordance with an image of a long region illuminated in one direction of the formation substrate 300. (Not shown).

  That is, the inclination angle θ2 of the imaging camera 720 is determined by the pitch P of the microprojections 302 (see FIG. 4) of the crystal grain boundary of the polycrystalline silicon film 301, the wavelength λ of the illumination light, and the illumination light to the formation substrate 300. The incident angle θ1 is determined based on the relationship of Equation 1.

  The inspection stage unit 740 places and holds the formation substrate 300 to be inspected on the upper surface of the inspection stage 741 that can be moved in the XY plane by the driving means 742. As the driving means 742, for example, a servo motor provided with a stepping motor or a rotary encoder may be used.

  On the other hand, the inspection data processing / control unit 640 includes an inspection unit data processing unit 750, an input / output unit 760, and a control unit 770. The control unit 770 is connected to the overall control unit 650 shown in FIG.

  The inspection data processing unit 750 pre-processes the A / D converted digital image signal by converting an analog image signal output from the imaging camera 720 into a digital image signal, and first-order diffracted light. An image processing unit 753 that creates an image of the image, and a processing determination unit 755 that obtains and images the crystal size distribution of the polycrystalline silicon film from the image.

  The input / output unit 760 includes a display unit 761 that displays a result processed by the process determination unit 755. The control unit 770 further includes a power source unit 772 for the light source 711, a driving unit control unit 773 for controlling the driving unit 742 for the inspection stage unit 740, and a control unit for controlling the inspection data processing unit 750, the output unit 760, and the power source unit 772. 771. The control unit 771 is connected to the overall control unit 650.

  With such a configuration, the inspection stage 741 is scanned in the scanning direction at the time of observation shown in FIG. 6, and rectangular scanning that shifts in the annealing direction is performed on a predetermined region or the entire surface of the formation substrate 300. 4 is obtained. Then, the distribution of crystal grain sizes of the polycrystalline silicon film 301 formed on the formation substrate 300 by processing in the inspection data processing 750 is obtained. The scanning of the inspection stage 741 may be rectangular scanning that scans in the annealing direction and shifts in the scanning direction shown in FIG.

  Next, a method for inspecting the state of crystal grain size distribution of the polycrystalline silicon film 301 that has been polycrystallized by annealing with an excimer laser on the formation substrate 300 using the inspection unit 621 having the configuration shown in FIG. explain.

  First, the flow of processing for inspecting the inspection region of the polycrystalline silicon film 301 formed on the formation substrate 300 by annealing of the excimer laser will be described. The inspection process includes an imaging sequence for imaging a predetermined region or the entire surface of the formation substrate 300 and an image processing sequence for processing an image obtained by imaging.

  First, the imaging sequence will be described with reference to FIG.

  First, the drive unit 773 is driven by the drive unit control unit 773 to control the position of the inspection stage 741 so that the inspection start position of the inspection region of the polycrystalline silicon film 301 falls within the field of view of the camera 720 of the inspection optical system 730. Then, the formation substrate 300 is set to the initial position (inspection start position) (S801).

  Next, the light source 711 is controlled by the power control unit 772, and light having a wavelength λ shaped linearly by the cylindrical lens 712 is irradiated to the polycrystalline silicon film 301 on the formation substrate 300 at an incident angle of θ 1 ( S802). The driving unit 773 controls the driving unit 742 so that the imaging region of the imaging camera 720 moves along the inspection region of the polycrystalline silicon film 301 irradiated with light of wavelength λ by the illumination optical system 710. The inspection stage 741 starts to move at a constant speed (S803).

  While moving the inspection stage 741 at a constant speed, the scanning direction of the polycrystalline silicon film 301 that is linearly shaped by the cylindrical lens 712 of the illumination optical system 710 and illuminated by light of wavelength λ incident at an angle θ1 An optical image of the first-order diffracted light generated in the direction θ2 is picked up by the image pickup camera 720 from the fine protrusion 302 of the crystal grain boundary in the very long inspection region (S804).

  The image signal from the imaging camera 720 that captured an optical image of the light of wavelength λ by the first-order diffracted light and the image signal from the transmitted light detection camera 730 that captured the transmitted light of the polycrystalline silicon film 301 are respectively inspected. It is processed by the data processing unit 750 to create a digital image (S805). The above operation is repeatedly executed until the inspection for one line along the X direction or the Y direction is completed (S806).

  Next, it is checked whether or not there is an inspection area adjacent to the inspected area for one line (S807). If there is an adjacent uninspected area, the inspection stage 741 is moved to the adjacent inspection area. (S808), the steps from S803 are repeated. When all the areas to be inspected have been inspected, the movement of the XY table is stopped (S809), the light source 711 is controlled by the power supply control unit 772 to turn off the illumination (S810), and the imaging sequence ends.

  Next, an image processing sequence for processing a digital image obtained by the imaging sequence in S804 will be described with reference to FIG.

  In the digital image creation step (S805) of the imaging sequence, the image signal from the imaging camera 720 is input to the A / D converter 752 and converted into a digital image signal. The A / D converted image signal from the imaging camera 720 is subjected to preprocessing such as shading correction by an image processing unit 753 to generate a digital image as shown in FIG. (S101).

  The processing determination unit 755 processes the predetermined region of the image input in S101, and extracts a boundary line having a particle size as shown in FIG. 2 (S102). Thereafter, for example, the boundary line is approximated to a quadrangle, and the particle size is calculated as an average value of the distance between opposite sides (S103), and a particle size distribution of the obtained particle size is obtained (S904).

  Next, a feature amount of the particle size distribution, for example, an average value and a standard deviation is obtained (S105), and the feature amount is compared with a preset reference value to determine the quality of the product (S106). Finally, the determination result and the particle size distribution are displayed on the display unit 761 of the input / output unit 760 (S107), and the image processing sequence is terminated.

  As described above, when detecting the intensity of the first-order diffracted light, the detection optical system is set so that the light irradiation angle α falls within the predetermined light irradiation angle range with respect to the annealing direction. Strength can be grasped more strongly. In particular, it is preferable to set α = 0 degrees, that is, a normal direction (90 degrees) with respect to the annealing direction. The detection angle is set corresponding to the light irradiation angle.

As a result, the grain size or grain size distribution can be grasped more accurately, and the polycrystalline silicon film can be inspected more accurately. Further, it is resistant to output fluctuations of the light source 711, and the polycrystalline silicon film can be inspected.
(Example 2)
FIG. 11 shows the overall configuration of a polycrystalline silicon film inspection apparatus 600A for a glass substrate for a liquid crystal display panel according to a second embodiment of the present invention. In the second embodiment, the annealing direction is detected before the formation substrate 300 is carried into the inspection unit 620, and the annealing direction falls within a predetermined light irradiation angle range of the light irradiation angle of the inspection optical system 730. Transport.

  In order to realize this, as shown in FIG. 12, the substrate loading unit 610A includes an annealing direction detecting unit 601 for detecting an annealing direction mark indicating the annealing direction, and a turning driving unit 603 for turning the load stage 602. . In the second embodiment, the orientation flat 300a of the formation substrate is used as the annealing direction mark, and the two imaging cameras 601a that image the orientation flat 300a are used as the annealing direction detection means 601. The two orientation flats 300a are provided at one corner of the molded substrate 300. With a large substrate, one imaging camera cannot see the four corners at a time. If one of the two units detects the orientation flat 300a, it is in the A state, and if neither unit is detected, it is determined that it is in the B state rotated 90 degrees with respect to the A state.

  In addition, the polycrystalline silicon film inspection apparatus 600A processes the detection result of the annealing direction detection means 601, and controls the turning drive means 603 to control the turning of the load stage 602 based on the processing result. Is provided.

  Based on the A / D conversion unit 661 that converts the image signal of the imaging camera 6 from analog to digital and the A / D converted digital image signal, the processing turning control unit 660 determines whether the molded substrate 300 is in the A state or B A substrate state determination unit 662 for determining whether or not the state is present. On the other hand, the overall control unit 650 stores whether the annealing direction for the orientation flat 300a is in the A state or the B state for each rod unit of the molded substrate 300 or for each molded substrate unit.

Therefore, the turning determination control unit 663 of the processing turning control unit 660 controls the turning drive unit 603 based on the determination result of the substrate state determination unit 662 and the stored data of the overall control unit 650.
As a result, the molded substrate 300 can be carried into the detection unit 620 with the annealing direction set to a predetermined direction.

  Also in this embodiment, the intensity of the first-order diffracted light can be grasped more strongly, the particle size or particle size distribution can be more accurately grasped, and the polycrystalline silicon film can be inspected more accurately. be able to. In addition, it is resistant to output fluctuations of the light source and can inspect the polycrystalline silicon film.

  In Example 2, the direction of the anilille was detected using the orientation flat 300a as the annealing direction mark and the relationship between the orientation flat position stored in advance and the annealing direction. The annealing direction mark is not limited to the orientation flat, and other features of the substrate and the molded substrate, and artificially provided marks may be used.

(Example 3)
In this embodiment, a dummy formed on the glass substrate 303 or an annealed polycrystalline silicon film actually used is used. Since it is the same in both the dummy case and the actual case, the dummy case will be described as an example. However, in practice, it is not necessary to form a dummy polycrystalline silicon film, which is advantageous in terms of process. On the other hand, in the case of the dummy, since the detection position is fixed, there is an advantage that stable detection is possible.

  For example, the dummy polycrystalline silicon film is formed at specific positions such as the four corners of the glass substrate 303 and annealed by a coating apparatus or an annealing apparatus upstream of the crystalline silicon film inspection apparatus 600 or 600A. Using the same or similar annealing direction detection inspection optical system shown in the first embodiment, the primary diffraction intensity of the polycrystalline silicon film as the annealing direction mark is detected. If the intensity is greater than or equal to a predetermined value, the irradiation direction of the annealing direction detection inspection optical system is the annealing direction and the normal direction, and if the intensity is equal to or less than the predetermined value, the irradiation direction is determined to be parallel to the annealing direction.

  If the annealing direction detection inspection optical system is provided in the substrate load portion 610A as in the second embodiment, the turning of the load stage 602 is controlled using the relationship between the annealing direction detection inspection optical system and the inspection optical system 730. When the inspection optical system 730 is used with the annealing direction detection inspection optical system, the inspection unit 620 is provided with a turning drive means for turning the inspection stage 741 and a processing turning control unit. Control the turn.

  In Example 3, as in Example 2, the intensity of the first-order diffracted light can be captured more strongly, and the particle size or particle size distribution can be more accurately grasped. A polycrystalline silicon film can be inspected. In addition, it is resistant to output fluctuations of the light source and can inspect the polycrystalline silicon film.

Example 4
FIG. 13 shows an embodiment 1000 of a polycrystalline silicon film forming apparatus for forming a polycrystalline silicon film having a polycrystalline silicon film inspection apparatus. The polycrystalline silicon film forming apparatus 1000 includes a coating apparatus 900 for applying amorphous silicon to the glass substrate 303, an annealing apparatus 800 for annealing the applied amorphous silicon film, and an inspection shown in FIG. 7 for inspecting the annealed amorphous silicon film. A device 600 is provided.

  In the fourth embodiment, the light irradiation angle α of the inspection optical system provided in the inspection apparatus 600 is always in the predetermined light irradiation angle range described above with respect to the annealing direction, particularly in the normal direction (90 degrees). An annealing apparatus 800 for annealing is provided in the inspection apparatus 600 in the previous stage.

  In Example 4, when the glass substrate 303 is carried into the coating apparatus 900 in consideration of the annealing direction, it is not necessary to provide the coating apparatus 900 or the annealing apparatus 800 with a turning drive means for turning the glass substrate 303 or the molded substrate 300. Therefore, the polycrystalline silicon film inspection apparatus 1000 can be configured simply.

  Conversely, when the glass substrate 303 is carried into the coating apparatus 900 without considering the annealing direction, for example, the position of the orientation flat 300a shown in the second embodiment is detected by the coating apparatus 900 or the annealing apparatus 800, and depending on the detection result. Further, a turning drive means for turning the glass substrate 303 or the forming substrate 300 is provided.

  According to the polycrystalline silicon film inspection apparatus 1000 of the fourth embodiment, as in the first to third embodiments, the intensity of the first-order diffracted light can be captured more strongly, and the particle size or particle size distribution can be more accurately determined. The polycrystalline silicon film can be inspected more accurately. In addition, it is resistant to fluctuations in the output of the light source and can inspect the polycrystalline silicon film.

300: forming substrate 302: minute projection 303: glass substrate 310: light source 320: imaging camera 600, 600A: crystalline silicon film inspection apparatus 601: annealing direction detecting means 601a: two imaging cameras for orientation flat imaging 602: load stage 603 : Rotation drive means 610, 610A: Substrate load unit 620: Inspection unit 621: Inspection unit 640: Inspection data processing / control unit 650: Overall control unit 660: Processing rotation control unit 662: Substrate state determination unit 663: Turn determination control unit 710: Illumination optical system 720: Imaging camera 730: Inspection optical system 740: Inspection stage section 741: Inspection stage 750: Inspection data processing section 755: Determination processing section 760: Input / output section 800: Annealing apparatus 900: Coating apparatus 1000: Crystalline silicon film forming device P: .

Claims (14)

An inspection stage for holding a formation substrate in which a polycrystalline silicon film is formed on the surface of a glass substrate;
Irradiation means for irradiating light to the polycrystalline silicon film at a light irradiation angle within a predetermined light irradiation angle range with respect to the normal direction of the annealing direction of the polycrystalline silicon film, and the polycrystal irradiated with the light An inspection optical system comprising: first imaging means for detecting first-order diffracted light generated from the surface of the silicon film at a predetermined light receiving angle with respect to the normal direction;
Inspection means for inspecting the state of the polycrystalline silicon film based on the intensity of the first-order diffracted light obtained by the inspection optical system;
A polycrystalline silicon film inspection apparatus.   2. The polycrystalline silicon film inspection apparatus according to claim 1, wherein the light irradiation angle range is within ± 30 degrees.   The polycrystalline silicon film inspection apparatus according to claim 1, wherein the light irradiation angles are mutually targeted with respect to the normal direction.   2. The polycrystalline silicon film inspection apparatus according to claim 1, wherein the light irradiation angle and the light receiving angle are both zero with respect to the normal direction. Annealing direction detecting means for detecting the annealing direction;
Swivel drive means for swiveling the glass substrate;
A process turning control unit for controlling the turning driving means based on the result of the annealing direction detecting means;
The polycrystalline silicon film inspection apparatus according to claim 1, further comprising: The annealing direction detecting means includes second imaging means for detecting an orientation flat position provided on the glass substrate,
The processing turning control unit detects the annealing direction based on the relationship between the orientation flat position stored in advance and the annealing direction,
The polycrystalline silicon film inspection apparatus according to claim 5. The annealing direction detection means includes an annealing direction detection inspection optical system having the same configuration as the inspection optical system that images the dummy polycrystalline silicon film formed on the glass substrate or the actually used polycrystalline silicon film after annealing. With
The processing turning control unit detects the annealing direction based on the intensity of the first-order diffracted light detected by the annealing direction detection inspection optical system.
The polycrystalline silicon film inspection apparatus according to claim 5. The inspection optical system also serves as the annealing direction detection inspection optical system,
The turning drive means turns the inspection stage;
The polycrystalline silicon film inspection apparatus according to claim 7.   2. The polycrystalline silicon film inspection apparatus according to claim 1, further comprising an annealing apparatus for unloading the formation substrate having an annealing direction suitable for the inspection optical system to the polycrystalline silicon film inspection apparatus. Irradiating the polycrystalline silicon film with light having a light irradiation angle within a predetermined light irradiation angle range with respect to the normal direction of the annealing direction of the polycrystalline silicon film formed on the glass substrate surface;
Detecting first-order diffracted light generated from the surface of the polycrystalline silicon film irradiated with the light at a predetermined light receiving angle;
Inspecting the state of the polycrystalline silicon film based on the intensity of the first-order diffracted light obtained by the detection,
A method for inspecting a polycrystalline silicon film.   11. The method for inspecting a polycrystalline silicon film according to claim 10, wherein the light irradiation angle range and the predetermined light receiving angle range are within ± 30 degrees.   11. The method for inspecting a polycrystalline silicon film according to claim 10, wherein the light irradiation angle and the light receiving angle are mutually targeted with respect to the normal direction.   11. The polycrystalline silicon film inspection method according to claim 10, wherein the light irradiation angle and the light receiving angle are both zero with respect to the normal direction.   11. The light according to claim 10, wherein the light irradiation is parallel light in one direction, and the substrate is irradiated with light that is condensed in a direction perpendicular to the one direction and shaped into a long shape. Crystalline silicon film inspection method.

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