Monitoring system for a laser crystallization apparatus

Abstract

A monitoring system of a laser crystallization apparatus according to an embodiment of the present application includes: a stage for supporting a substrate; a laser beam generating section for providing a laser beam to the substrate; a scattered beam detecting section for detecting a scattered beam of the laser beam scattered on the substrate; and a control section for receiving and storing data related to intensity of the scattered beam detected, and correcting intensity of the laser beam of the laser beam generating section based on the data.

Description

TECHNICAL FIELD

[0001] The present invention relates to a monitoring system of a laser crystallization apparatus, and more particularly, to a monitoring system of a laser crystallization apparatus for manufacturing a polysilicon thin film of improved quality. BACKGROUND

[0002] Recently, with the development of technology, there have appeared display products that are small, light, and have superior performance. Among display devices up to now, the existing cathode ray tube (CRT) has many advantages in performance or price and is widely used, but has overcome the disadvantages of the CRT in terms of miniaturization or portability, and display devices such as plasma display devices, liquid crystal display devices, and organic light emitting display devices, which have advantages such as miniaturization, lightness, and low power consumption, have attracted attention.

[0003] The above display device includes a thin film transistor, which is a special kind of field effect transistor made of a semiconductor thin film on an insulating support substrate. The thin film transistor has three terminals of a gate, a drain, and a source, like a field effect transistor, and its main function is switching operation. The thin film transistor can also be used for sensors, storage elements, optical elements, etc., but is mainly used as a pixel switching element or a driving element of the display device.

[0004] As the above display device is becoming larger and higher definition, the elements are also required to have high performance, and thus, a manufacturing technique of a high performance thin film transistor having a higher mobility than that of an amorphous silicon thin film transistor having a mobility of 0.5 to 1 cm 2 Vs is required. A poly-Si TFT has significantly superior performance to that of an existing amorphous silicon thin film transistor. The poly-Si TFT has a mobility of several tens of cm 2 Vs to several hundreds of cm 2 Vs. Thus, a data driving circuit or a peripheral circuit, etc., which require a higher mobility, can be incorporated into a substrate, and the channel of the transistor can be made smaller to increase the aperture ratio of the screen. Also, since the driving circuit is incorporated, there is no limitation on the wiring pitch for connecting the driving circuit as the number of pixels increases, and thus, it has the advantages of enabling high resolution, reducing the driving voltage and power consumption, and having less problems of deterioration of element characteristics.

[0005] In order to produce the above-mentioned polycrystal silicon thin film transistor, an excimer laser (ELC) crystallization technique and the like for crystallizing amorphous silicon to produce polycrystal silicon are being studied. However, the crystallinity of such polycrystal silicon is difficult to be observed with naked eyes, and the allowable error range is limited, and thus various methods and devices for uniformly maintaining the crystallinity of polycrystal silicon are required. SUMMARY

[0006] The technical problem to be solved by the present application is based on the above-mentioned point, and the present application aims to provide a monitoring system for a laser crystallization device for forming a polycrystal silicon thin film with improved quality.

[0007] Another object of the present application is to provide a laser crystallization method using the above-mentioned monitoring system for a laser crystallization device.

[0008] The monitoring system for a laser crystallization device according to an embodiment for achieving the above-mentioned object of the present application includes: a stage for supporting a substrate; a laser beam generating section for providing a laser beam to the substrate; a scattered beam detecting section for detecting a scattered beam of the laser beam scattered on the substrate; and a control section for receiving and storing data related to the intensity of the detected scattered beam, and correcting the intensity of the laser beam provided by the laser beam generating section based on the data.

[0009] In an embodiment of the present application, an amorphous silicon thin film is formed on the substrate, and the amorphous silicon thin film is crystallized by the laser beam to form a polycrystal silicon thin film.

[0010] In an embodiment of the present application, the control section corrects laser energy as the intensity of the laser beam based on the stored data, or generates feedback information for adjusting an optical system for forming the laser beam, and provides the laser beam generating section or the optical system.

[0011] In an embodiment of the present application, the control section determines whether the crystallization degree of the substrate in a job is appropriate based on the stored data, and provides rework information related to whether the substrate is reworked to the stage based on the determination.

[0012] In an embodiment of the present application, the laser beam is incident on the substrate in a form having an incident angle (a1), and emits a reflected beam having a reflection angle (a2) and a scattered beam having a scattering angle (a3). The scattering angle of the scattered beam can be greater than the reflection angle.

[0013] In an embodiment of the present application, the substrate is disposed on a plane constituted by a first direction and a second direction perpendicular to the first direction, the stage moves the substrate in the first direction,

[0014] The laser beam is a long quadrilateral shaped line beam in the second direction.

[0015] In one embodiment of the present application, a plurality of the scattered light beam detecting sections are arranged along the second direction to detect the scattered light beams at a plurality of positions along the second direction, and the control section stores data related to the intensity of the scattered light beams at the plurality of positions along the second direction.

[0016] In one embodiment of the present application, the monitoring system of the laser crystallization apparatus further includes: a chamber, the chamber is formed with an annealing window at a position through which the laser beam passes, the chamber is a sealed box shape; a beam cutting device, arranged in the chamber, cutting the end of the laser beam; a beam collector, arranged in the chamber, absorbing and dissipating the laser beam reflected on the substrate; a mirror, arranged in the chamber, reflecting the scattered light beam scattered on the substrate; and a lens, the scattered light beam reflected from the mirror passes through the lens, and the scattered light beam is guided to the scattered light beam detecting section.

[0017] In one embodiment of the present application, the monitoring system of the laser crystallization apparatus further includes: an alignment laser generating section, arranged in the chamber, generating an alignment laser; an alignment lens, the alignment laser generated by the alignment laser generating section passes through the alignment lens; and an alignment mirror, reflecting the alignment laser passing through the alignment lens, the alignment laser reflected from the alignment mirror is sequentially reflected from the substrate and the mirror, and then passes through the lens to be incident on the scattered light beam detecting section.

[0018] In one embodiment of the present application, the monitoring system of the laser crystallization apparatus further includes a conversion section, the conversion section analogizes or digitizes the intensity of the scattered light beam detected by the scattered light beam detecting section, and the control section receives data related to the intensity of the scattered light beam analogized or digitized from the conversion section.

[0019] A laser crystallization method for achieving the above-mentioned object of the present application includes: an OPED setting and laser alignment step of setting the intensity of a laser generated by a laser generator and aligning the position of a laser beam irradiated on a substrate; a crystallization step of irradiating the laser beam on the substrate on which an amorphous silicon thin film is formed to crystallize the amorphous silicon thin film and form a polycrystalline silicon thin film; a crystallization monitoring step of detecting and monitoring the intensity of a scattered light beam in which the laser beam is scattered on the substrate in the crystallization step; and a real-time feedback step of correcting the laser crystallization conditions based on the intensity of the scattered light beam detected in the crystallization monitoring step.

[0020] In one embodiment of the present application, the laser crystallization method can further include a crystallization normality judging step of judging whether the crystallinity of the polycrystal silicon thin film crystallized in the crystallization step is within an appropriate range. The judging can be performed based on the intensity of the scattered light beam detected in the crystallization monitoring step.

[0021] In one embodiment of the present application, the crystallization normality judging step can judge that the crystallization is normal if the intensity of the scattered light beam is close to a peak value, and judge that the crystallization is abnormal if the intensity of the scattered light beam is outside a predetermined range from the peak value. The peak value can be a peak value of a graph of the intensity of the scattered light beam with respect to the intensity of the laser beam.

[0022] In one embodiment of the present application, the laser crystallization method can further include a laser energy changing step of changing the intensity of the laser beam to an appropriate level based on the intensity of the scattered light beam if the crystallization is judged to be abnormal in the crystallization normality judging step.

[0023] In one embodiment of the present application, the laser crystallization method can further include an optical system changing step of adjusting an optical system that generates the laser beam if the crystallization is judged to be abnormal in the crystallization normality judging step.

[0024] In one embodiment of the present application, the laser crystallization method can further include a rework step of re-crystallizing the substrate on which the crystallization has been performed if the crystallization is judged to be abnormal in the crystallization normality judging step.

[0025] In one embodiment of the present application, the laser crystallization method can further include a real-time data storing step of storing the intensity of the scattered light beam detected and the corrected laser crystallization conditions in a database in real time.

[0026] In one embodiment of the present application, the laser crystallization method can further include a test substrate manufacturing step of calculating an OPED (Optimized Energy Density) value of the laser beam.

[0027] In one embodiment of the present application, the test substrate manufacturing step can further include a laser energy initial value setting step of setting the intensity of the laser beam to an initial value to align the position of the laser beam, a test substrate crystallization step of irradiating the laser beam to a first region of a test substrate on which an amorphous silicon thin film is formed, a laser energy changing step of setting the intensity of the laser beam to a value different from the initial value and irradiating the laser beam to a second region different from the first region to crystallize the amorphous silicon thin film of the second region, a crystallization monitoring step of crystallizing regions different from each other while changing the intensity of the laser beam and measuring the intensity of the scattered light beam in each case, and an OPED calculating step of calculating the OPED using the monitored data.

[0028] A laser crystallization method according to one embodiment for achieving the object of the present application includes a laser irradiation step of irradiating a laser beam to a substrate, a scattered light beam detection step of detecting the intensity of a scattered light beam scattered on the substrate by the laser beam in the laser irradiation step, and a laser energy correction step of correcting the intensity of the laser beam based on the detected intensity of the scattered light beam.

[0029] Inventive Effects

[0030] According to one embodiment of the present application, the monitoring system of the laser crystallization apparatus monitors the intensity data of the scattered light beam detected by the scattered light beam detection section in real time, so there is no detection deviation caused by the user, the control section controls using appropriate feedback information to achieve the optimal crystallinity, so that real-time measurement of the crystallinity according to the crystallization energy change can be performed and the optimal energy can be determined using this, not only can the crystallization defects be detected in advance, but also the decision on whether to rework can be automatically controlled. Furthermore, the alignment laser can be used for pre-alignment, so that the scattered light beam detection section can accurately detect the scattered light beam.

[0031] That is, the monitoring system of the laser crystallization apparatus determines the OPED by finding the peak value of the intensity of the scattered light beam according to the laser energy and other conditions of the laser generation section, so that the optimal laser intensity can be determined, which is monitored and fed back in real time, so that the optimal crystallinity can be maintained according to the process conditions for multiple substrates.

[0032] However, the effects of the present application are not limited to the above effects, and various extensions can be made without departing from the spirit and scope of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 is a schematic diagram showing a monitoring system of a laser crystallization apparatus according to one embodiment of the present application.

[0034] Figure 2 is a schematic view showing a configuration of an alignment section of a monitoring system of a laser crystallization apparatus. Figure 1

[0035] Figure 3 is a scanning electron microscope (SEM) photograph of a surface of a crystallized polysilicon thin film using a monitoring system of a laser crystallization apparatus according to an embodiment of the present application.

[0036] Figure 4 is a graph showing an intensity of a scattered light beam with respect to a digitized laser intensity using a monitoring system of a laser crystallization apparatus according to an embodiment of the present application.

[0037] Figure 5A is an example of a graph showing an intensity of a scattered light beam with respect to a digitized laser intensity using a monitoring system of a laser crystallization apparatus according to an embodiment of the present application.

[0038] Figure 5B is an atomic force microscope (AFM) photograph of a surface of a polysilicon thin film with respect to each laser energy level in the graph of Figure 5A

[0039] Figure 6 is a sequence chart showing a step of manufacturing a test substrate for monitoring a laser crystallization method according to an embodiment of the present application.

[0040] Figure 7 is a sequence chart showing a step of manufacturing a test substrate for monitoring a laser crystallization method according to an embodiment of the present application.

[0041] Figure 8 is a plan view of a substrate irradiated with a laser using a monitoring system of a laser crystallization apparatus according to an embodiment of the present application.

[0042] Reference Signs:

[0043] 10: substrate 100: laser generation section

[0044] 200: chamber 210: annealing window

[0045] 220: beam cutting device 230: beam current collector

[0046] 250: scattered light beam detection section 260: alignment laser generation section

[0047] 300: stage 400: conversion section

[0048] ​​500: Control Unit L: Laser Beam

[0049] MR: Mirror; LN: Lens

[0050] MRa: Alignment Mirror LNa: Alignment Lens

[0051] RW: Return to work information; FB: Feedback information Detailed Implementation

[0052] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0053] Figure 1 This is a schematic diagram illustrating the monitoring system of a laser crystallization apparatus according to an embodiment of the present invention. Figure 2 It is a general overview Figure 1 A schematic diagram of the alignment section of the monitoring system of the laser crystallization device.

[0054] Reference Figure 1 The monitoring system of the aforementioned laser crystallization apparatus includes: a laser generating unit 100, a chamber 200, an annealing window 210, a beam cutter 220, a beam collector 230, a mirror MR, a lens LN, a scattered beam detection unit 250, a worktable 300, a conversion unit 400, and a control unit 500.

[0055] The aforementioned worktable 300 can support the substrate 10 to be irradiated by the laser beam L. The worktable 300 moves in a first direction D1 to the substrate 10, which is disposed on the plane formed by the first direction D1 and the second direction D2 perpendicular to the first direction D1, thereby enabling the laser beam to scan the entire substrate 10.

[0056] An amorphous silicon thin film (not shown) can be formed on the substrate 10. This amorphous silicon thin film can be formed using silicon or a silicon substrate (e.g., SixGe1-x) by existing methods such as sputtering, reduced-pressure CVD, or plasma CVD. By irradiating the amorphous silicon thin film with a laser beam, it is crystallized, forming a polycrystalline silicon (polysilicon) thin film. The crystallization principle of the amorphous silicon thin film involves rapidly raising the temperature of the amorphous silicon by irradiating it with a laser beam for several nanoseconds, followed by cooling, thereby melting and recrystallizing the amorphous silicon. The crystallized polycrystalline silicon thin film has an electric field mobility (μFE) hundreds of times higher than that of amorphous silicon and excellent signal processing capabilities at high frequencies, thus making it suitable for use in display devices such as organic light-emitting display devices.

[0057] The laser beam generating section 100 generates a laser beam, which can be irradiated onto the substrate 10. The laser beam can be formed using laser light generated by a laser oscillator. The laser light can be a gas laser or a solid laser. Examples of the gas laser include argon (Ar) laser, krypton (Kr) laser, and the like. Examples of the solid laser include YAG laser (Yttrium Aluminum Garnet), YVO4 laser (Yttrium Orthovanadate), YLF laser (Yttrium lithium fluoride), YAlO3 laser (Yttrium Aluminate), Y2O3 laser (Yttrium oxide), glass laser, ruby laser, alexandrite laser, Ti-sapphire laser, and the like.

[0058] The laser light emitted from the laser oscillator can have a Gaussian distribution of energy density, and is provided to the substrate 10 in a line beam shape via an optical system (not shown) including a plurality of mirrors and / or lenses (see FIG. 2). Figure 8

[0059] In order to obtain the laser beam having a desired size, the optical system can include a plurality of lenses and reflecting members, and the like. Further, the optical system can guide the laser light generated from the laser oscillator to be irradiated to a desired position. Through the optical system, the laser light forms a line beam in a long quadrilateral shape in the second direction D2 in a plane constituted by the first direction Dl and the second direction D2, and the line beam can be irradiated to the substrate 10 with an incident angle a1 with respect to a third direction D3 perpendicular to the first direction Dl and the second direction D2.

[0060] The chamber 200 can be in a sealed box shape, and the annealing window 210 can be provided at a position through which the laser beam passes. In order to prevent the laser beam from being contaminated and to maintain stability in the chamber 200, the chamber 200 is filled with a non-reactive gas such as nitrogen (N2).

[0061] The beam cutting device 220 can be provided in the chamber 200. The beam cutting device 220 cuts the end of the laser beam to block a peripheral scattered beam at the end of the laser beam, so that the irradiation area of the laser beam to the substrate 10 can be made clear.

[0062] ​The beam dump 230 can be disposed in the chamber 200. The beam dump 230 absorbs and dissipates the laser beam reflected from the substrate 10. The laser beam incident on the substrate 10 at the incident angle a1 is reflected from the surface of the substrate 10, and the reflected laser beam having a reflection angle a2 can be incident on the beam dump 230 and dissipated. The reflection angle a2 can be the same as the incident angle a1.

[0063] The laser beam incident on the substrate 10 at the incident angle a1 is scattered from the surface of the substrate 10 to form a scattered beam, and as the amorphous silicon thin film on the substrate 10 is crystallized, a plurality of protrusions are formed on the polycrystalline silicon layer. Due to the protrusions, the laser beam is scattered and can have a scattering angle a3 different from the reflection angle a2 to be emitted from the substrate 10.

[0064] Further, the scattering angle a3 of the scattered beam can be calculated by the following equation.

[0065] d*(sin(a3)-sin(a1))=mλ

[0066] (here, d is the distance between protrusions, λ is the wavelength of the incident beam, a1 is the incident angle, and a3 is the scattering angle)

[0067] When the protrusions having appropriate sizes and regularity are formed on the polycrystalline silicon thin film, the scattering angle a3 of the scattered beam can be greater than the incident angle a1.

[0068] The mirror MR and the lens LN can be disposed in the chamber 200. The scattered beam is reflected by the mirror MR, passes through the lens LN, and is incident on the scattered beam detector 250, so that the scattered beam detector 250 can detect the intensity of the scattered beam. The scattered beam detector 250 can be a light receiving element such as a photodetector.

[0069] The intensity of the scattered beam detected by the scattered beam detector 250 is input to the conversion unit 400, and is converted into an analog value by being analogized or into a digital value by being digitized.

[0070] The intensity of the scattered beam analogized or digitized is supplied to the control unit 500, the control unit 500 stores the intensity of the scattered beam for each condition in real time, corrects the laser energy as the intensity of the laser beam based on this, or supplies feedback information FB for adjusting the optical system to the laser generator 100 and the optical system. That is, according to the monitoring system of the laser crystallization apparatus, the laser conditions and the crystallinity can be monitored in real time and fed back, and thus the crystallization quality can be improved.

[0071] In addition, based on the stored values, it can be determined whether the crystallization degree of the substrate 10 in operation is appropriate, and the control unit 500 can provide rework information (RW) to the worktable 300 based on this. If the crystallinity of the polycrystalline silicon thin film on the substrate 10 is not appropriate, the polycrystalline silicon thin film is subjected to laser irradiation again (rework) to appropriately compensate for the crystallinity.

[0072] Furthermore, data transmission between the respective components can be wired or wireless. For example, the conversion unit 400 and the control unit 500 can transmit data to each other wirelessly.

[0073] Reference Figure 2 In order to align the scattered light beam detection unit 250, the monitoring system of the laser crystallization apparatus can further include an alignment laser generation unit 260, an alignment lens LNa, and an alignment mirror MRa. Alignment laser generated by the alignment laser generation unit 260 can be reflected by the alignment mirror MRa through the alignment lens LNa. Thereafter, the alignment laser is reflected from the substrate 10 and can be incident on the scattered light beam detection unit 250 through the mirror MR and the lens LN. With the alignment laser, the scattered light beam of the laser beam enters the scattered light beam detection unit 250, thereby pre-aligning the scattered light beam detection unit 250 so that the scattered light beam detection unit 250 can accurately detect the scattered light beam.

[0074] Generally, the detection of the crystallinity of the polycrystalline silicon thin film uses visual detection (manual macro) in which a detector directly detects with the naked eye or an automatic detection device (auto-macro). However, visual detection has a large variation depending on the detector, and in the case of using an automatic detection device, although a mottling defect can be detected, the laser energy required for optimal crystallinity and optical system adjustment information cannot be obtained.

[0075] According to the present embodiment, the monitoring system of the laser crystallization apparatus uses the scattered light beam detection unit and the conversion unit to monitor analog or digital data in real time. Therefore, there is no variation depending on the user, and since the control unit controls using appropriate feedback information to achieve optimal crystallinity, the crystallinity according to the crystallization energy variation can be measured in real time, and this can be used to determine the optimal energy, not only to detect crystallization defects in advance, but also to automatically control the decision on rework. Furthermore, the scattered light beam detection unit can be pre-aligned using the alignment laser so that the scattered light beam detection unit accurately detects the scattered light beam.

[0076] Figure 3 is a scanning electron microscope (SEM) photograph of a surface of a crystallized polysilicon thin film using a monitoring system of a laser crystallization apparatus according to an embodiment of the present application.

[0077] Referring to Figure 3 It can be observed that the protrusions on the crystallized polysilicon thin film crystallized by the laser crystallization are arranged at predetermined intervals to form a pattern.

[0078] Figure 4 is a graph showing the intensity of a scattered light beam with respect to a digitized laser intensity according to a monitoring system of a laser crystallization apparatus according to an embodiment of the present application.

[0079] Referring to Figure 4 By the monitoring system of the laser crystallization apparatus, the intensity of the scattered light beam can be monitored, and the intensity variation of the scattered light beam can be monitored by setting the laser energy (laser intensity) of the laser generation unit to be different.

[0080] In the graph, the x-axis represents the laser beam intensity, i.e., the laser intensity (unit: (mJ / cm 2 ), and the y-axis represents the intensity of the scattered light beam detected by the scattered light beam detection unit (unit: (mJ / cm 2 ). Here, PEAK is the maximum value of the intensity of the detected scattered light beam, and RMS is the root mean square value.

[0081] In the graph, the laser intensity corresponding to the portion (dotted oval portion) where the maximum value of the detected scattered light beam is determined as OPED (Optimized Energy Density (mJ / cm 2 ).

[0082] That is, the monitoring system of the laser crystallization apparatus can monitor the intensity of the scattered light beam of the laser beam in real time according to the laser energy and other conditions of the laser generation unit, find the peak value of the intensity of the scattered light beam, and determine it as OPED. Thus, the optimal laser intensity can be determined, and since this is monitored in real time and fed back, the optimal crystallinity can be maintained according to the process conditions for a plurality of substrates.

[0083] Figure 5A is an example of a graph showing the intensity of a scattered light beam with respect to a digitized laser intensity according to a monitoring system of a laser crystallization apparatus according to an embodiment of the present application. Figure 5B is a graph showing the intensity of a scattered light beam with respect to a digitized laser intensity according to a monitoring system of a laser crystallization apparatus according to an embodiment of the present application.

[0084] Figure 5A Atomic Force Microscope (AFM) photographs of the surface of the polycrystalline silicon thin film for each laser energy level.

[0085] Referring to Figure 5A , the OPED (Optimized Energy Density) value can be determined as the peak value 426 mJ / cm 2 , referring to Atomic Force Microscope (AFM) photographs of the surface of the polycrystalline silicon thin film for each laser energy level Figure 5B , it can be confirmed that the OPED (Optimized Energy Density) value is 421 mJ / cm 2 to 432 mJ / cm 2 , it can be confirmed that 426 mJ / cm 2 is a suitable value.

[0086] Figure 6 is a sequence diagram illustrating a test substrate manufacturing step of monitoring a laser crystallization method according to an embodiment of the present application. Figure 7 is a sequence diagram illustrating a test substrate manufacturing step of monitoring a laser crystallization method according to an embodiment of the present application.

[0087] Referring to Figure 1 and Figure 6 , the test substrate manufacturing step of the laser crystallization method can be performed using the monitoring system of the laser crystallization apparatus illustrated in Figure 1 .

[0088] The test substrate manufacturing step includes a laser energy setting and laser alignment step S110, a test substrate crystallization step S120, a laser energy changing step S130, a crystallization monitoring step S140, an OPED calculating step S150, a position distribution normality judging step S160, an optical system changing step S170, and a test end step S180.

[0089] The test substrate manufacturing step is for testing the difference in crystallinity according to various levels of laser energy, forming an amorphous silicon thin film on a substrate, irradiating a plurality of regions with laser beams set with various levels of laser energy, and thus comparing the crystallinity for each of the regions. Through this method, the crystallinity according to the intensity of laser energy, the intensity of scattered light, and the degree of setting of the optical system can be monitored, and the optimal OPED can be calculated.

[0090] In the laser energy setting and laser alignment step S110, the intensity of the laser beam can be set to an initial value, and the position of the laser beam can be aligned.

[0091] In the crystallization step S120, the laser beam is irradiated to the first region of the test substrate on which the amorphous silicon thin film is formed, thereby crystallizing the amorphous silicon thin film of the first region.

[0092] In the laser energy changing step S130, the intensity of the laser beam is set to a value different from the initial value, and the laser beam is irradiated to a second region different from the first region, thereby crystallizing the amorphous silicon thin film of the second region.

[0093] In the crystallization monitoring step S140, the intensity of the laser beam is changed to crystallize regions different from each other, and the intensity of the scattered light beam in each case is measured and monitored.

[0094] In the OPED calculating step S150, the OPED is calculated using the monitored data. For example, as shown in the graph of FIG. 6, the peak value of the graph can be selected to calculate the OPED value. Figure 4

[0095] In the position-dependent distribution normality judging step S160, the OPED value is used to crystallize the next region, and the position-dependent distribution is calculated by detecting the scattered light beam at a plurality of positions. If the distribution is within a predetermined range, it can be judged to be normal, and if it is outside the predetermined range, it can be judged to be abnormal.

[0096] If it is judged to be abnormal in the position-dependent distribution normality judging step S160, the optical system changing step S170 is performed to correct the alignment of the laser beam. By repeating this process, the optimum laser irradiation conditions can be determined.

[0097] If it is judged to be normal in the position-dependent distribution normality judging step S160, the test end step S180 is performed, and the production of the test substrate is completed, and the laser crystallization process of the processed substrate can be performed.

[0098] Referring to FIGS. 1 to 6, Figure 1 and Figure 7 the laser crystallization method includes an OPED setting and laser alignment step S210, a crystallization step S220, a crystallization monitoring step S230, a crystallization normality judging step S240, a laser energy changing step S250, an optical system changing step S260, a rework step S270, and a process end step S290.

[0099] ​In the OPED setting and laser alignment step S210 described above, the laser energy of the laser beam generating section 100 can be set using the OPED value calculated in the test substrate manufacturing step described above. Also, the laser beam generating section 100 and the optical system can be aligned to align the position of the laser beam on the substrate 10.

[0100] In the crystallization step S220 described above, the amorphous silicon thin film on the substrate 10 is crystallized by irradiating a laser beam, thereby forming a polycrystalline silicon thin film.

[0101] In the crystallization monitoring step S230 described above, the intensity of the scattered light beam scattered from the substrate 10 by the laser beam in the crystallization step S220 is detected, and the intensity of the scattered light beam, the laser energy, the setting information of the optical system, and the like are stored and monitored in real time.

[0102] In the crystallization normality judgment step S240 described above, it can be judged whether the crystallinity of the polycrystalline silicon thin film crystallized in the crystallization step S220 is within an appropriate range. The judgment can be performed based on the intensity of the scattered light beam detected in the crystallization monitoring step S230. For example, if the intensity of the scattered light beam according to the laser energy approaches a peak value, it can be judged to be normal, and if the intensity of the scattered light beam exceeds a predetermined range from the peak value, it can be judged to be abnormal.

[0103] If it is judged to be abnormal in the crystallization normality judgment step S240 described above, real-time feedback to correct the laser crystallization conditions can be constituted based on the intensity of the scattered light beam detected in the crystallization monitoring step S230. The real-time feedback can be a change in the laser energy (see S250), a change in the optical system (see S260), rework (see S270), and the like.

[0104] In the laser energy change step S250 described above, the laser energy of the laser beam generating section 100 can be changed to an appropriate level based on the intensity of the scattered light beam. For example, if the intensity of the scattered light beam moves to the right from the peak value of the graph (see Figure 4 ), the laser energy is reduced by an amount calculated from the graph to adjust the intensity of the scattered light beam to have a peak value again.

[0105] In the optical system change step S260 described above, the optical system can be adjusted to adjust the laser beam. The irradiation conditions of the laser beam are not only related to the laser energy as the intensity of the laser beam, but also related to the alignment and setting of the optical system, and if only the laser energy is adjusted and the desired intensity of the scattered light beam cannot be detected, the optical system needs to be adjusted.

[0106] In the rework step S270, it is determined whether to re-perform the crystallization of the substrate (rework), so that rework can be performed. In a case where the crystallinity does not satisfy an appropriate level, the crystallinity of the crystallized polysilicon thin film, i.e., the uniformity of the formed protrusions, the crystal size, and the like do not satisfy an appropriate level, so that the desired polysilicon characteristics cannot be obtained. Thus, the laser beam is irradiated again to the crystallized polysilicon thin film to perform a melting and recrystallization operation.

[0107] In addition, the crystallinity is generally improved by the laser energy changing step S250, and if the crystallinity is not improved even by the laser energy changing step S250, the crystallinity can be improved by the optical system changing step S260. Further, even if the crystallinity is not improved after the optical system changing step S260, the rework step S270 can be performed. However, the order is not limited to the above, and the control section 500 can directly perform an appropriate step using accumulated data.

[0108] In the real-time data storage step S280, the intensity of the scattered light beam detected in the crystallization monitoring step S230, the crystallization normality determining step S240, the laser energy changing step S250, the optical system changing step S260, the rework step S270, and the like, and the corrected laser crystallization conditions and the like are stored in real time and are databased. Using the database, the control section 500 can generate a desired feedback signal FB or a rework signal RW.

[0109] In a case where it is determined to be normal in the crystallization normality determining step S240, a subsequent process or the process end step S290 in which an end process is performed can be performed.

[0110] Figure 8 is a plan view showing a substrate on which a laser is irradiated using a monitoring system of a laser crystallization apparatus according to an embodiment of the present application.

[0111] Referring to Figure 1 and Figure 8 In order to detect the scattered light beam at a plurality of positions TA1, TA2, TA3 along the second direction D2, the scattered light beam detecting section 250 can be distributed along the second direction D2. Thus, the control section 500 can store data on the intensity of the scattered light beam at a plurality of positions along the second direction D2, and by this, if the laser beam is in a linear beam form, the distribution of the scattered light beam along the length direction of the linear beam can be controlled, and thus the distribution of the crystallinity along the second direction D2 can be controlled.

[0112] According to the embodiment of the present application, the monitoring system of the laser crystallization apparatus monitors the analogized data or the digitized data in real time by using the scattered beam detecting unit and the converting unit, so there is no detection deviation according to the user, the control unit controls by using the appropriate feedback information to achieve the optimal crystallinity, so the real-time measurement of the crystallinity according to the crystallization energy conversion and the determination of the optimal energy by using the same can be achieved, not only the poor crystallization can be detected in advance, but also the decision of whether to rework can be automatically controlled. Moreover, the pre-alignment can be performed by using the alignment laser, so that the scattered beam detecting unit can accurately detect the scattered beam.

[0113] That is, the monitoring system of the laser crystallization apparatus monitors the intensity of the scattered beam of the laser beam in real time according to the laser energy and other conditions of the laser generating unit, finds the peak value of the intensity of the scattered beam and determines it as OPED. Thus, the optimal laser intensity can be determined, which is monitored in real time and fed back, so that the optimal crystallinity for multiple substrates can be maintained according to multiple process conditions.

[0114] Industrial applicability

[0115] The present application can be applied to organic light emitting display devices and various electronic devices including the same. For example, the present application can be applied to mobile phones, smartphones, video phones, smart pads, smart watches, tablet computers, car navigation devices, televisions, computer monitors, notebook computers, head-mounted displays, etc.

[0116] The above has been described with reference to the exemplary embodiments of the present application, but it should be understood by those skilled in the art that various modifications and changes can be made to the present application without departing from the spirit and scope of the present application as recited in the claims.

Claims

1. A monitoring system for a laser crystallization device, wherein, include: The worktable is used to support the substrate. The laser generating unit provides a laser beam to the substrate; A chamber having an annealing window formed at the location where the laser beam passes, the chamber being a sealed box shape; A mirror, disposed within the cavity, reflects the scattered beam of the laser beam scattered on the substrate; A lens is disposed within the cavity, through which the scattered light beam reflected from the mirror passes; A scattered beam detection unit detects the scattered beam passing through the lens; and, The control unit receives and stores data related to the intensity of the detected scattered beam, and corrects the intensity of the laser beam provided by the laser generating unit based on the data. The laser beam is incident on the substrate at an angle of incidence and exits as a reflected beam with a reflection angle and a scattered beam with a scattering angle. The scattering angle of the scattered beam is greater than the reflection angle. The mirror is positioned in the path of the scattered light beam. An amorphous silicon thin film is formed on the substrate. The amorphous silicon thin film is crystallized by the laser beam to form a polycrystalline silicon thin film. The substrate is disposed on a plane formed by a first direction and a second direction perpendicular to the first direction, and the worktable moves the substrate in the first direction. The laser beam is a straight beam with a quadrilateral shape that is longer in the second direction. Multiple scattered beam detection units are arranged along the second direction to detect scattered beams at multiple positions along the second direction. The scattering angle and the incident angle satisfy the following equation: d*(sin(a3)-sin(a1))=mλ Where d is the target distance between the protrusions formed on the polycrystalline silicon thin film, λ is the wavelength of the laser beam, a1 is the incident angle, and a3 is the scattering angle.

2. The monitoring system for the laser crystallization device according to claim 1, wherein, The control unit corrects the laser energy, which is the intensity of the laser beam, based on the stored data, or generates a feedback signal to adjust the optical system used to form the laser beam, and provides it to the laser generating unit or the optical system.

3. The monitoring system for the laser crystallization apparatus according to claim 1, wherein, Based on the stored data, the control unit determines whether the degree of crystallization of the substrate during the operation is appropriate, and provides the workbench with rework information related to whether the substrate needs to be reworked.

4. The monitoring system for the laser crystallization device according to claim 1, wherein, The control unit stores data related to the intensity of the scattered beam at multiple locations along the second direction.

5. The monitoring system for the laser crystallization device according to claim 1, wherein, Also includes: A beam cutting device, disposed within the cavity, cuts off the end of the laser beam; and, A beam collector, disposed within the cavity, absorbs and dissipates the laser beam reflected onto the substrate.

6. The monitoring system for the laser crystallization apparatus according to claim 5, wherein, Also includes: An alignment laser generating unit is disposed within the cavity to generate an alignment laser. Alignment lens, the alignment laser generated by the alignment laser generating unit passes through the alignment lens; and, The alignment mirror reflects the alignment laser light passing through the alignment lens. The alignment laser reflected from the alignment mirror is reflected sequentially from the substrate and the mirror, and then passes through the lens to the scattered beam detection unit.

7. The monitoring system for the laser crystallization apparatus according to claim 1, wherein, It also includes a transformation unit that simulates or digitizes the intensity of the scattered beam detected by the scattered beam detection unit. The control unit receives intensity-related data of the scattered beam, which has been simulated or digitized, from the transformation unit.

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