Laser annealing device and method for manufacturing electronic device

Abstract

A laser annealing device according to one aspect of the present disclosure is configured to uniformly irradiate a plurality of processed areas arranged along at least a second direction of a first direction and a second direction perpendicular to the first direction within a surface of a workpiece with laser light, and to move the uniformly irradiated area and the workpiece relative to each other in the first direction for scanning. The laser annealing device comprises: an energy density measuring device for measuring the energy density of at least the second end of the uniformly irradiated area in the second direction; an energy density adjusting device for adjusting the energy density of the first end; and a controller for controlling the energy density adjusting device based on the measurement result of the energy density measuring device to adjust the energy density of the first end during the N+1th scan so that the energy density of the first end of the N+1th scanning area adjacent to the second end of the Nth scanning area approaches the energy density of the second end of the Nth scanning area.

Description

Technical Field

[0001] The present disclosure relates to a laser annealing apparatus and a method for manufacturing an electronic device. Background Art

[0002] Thin-film transistors (TFTs) are used as driving elements in flat-panel displays using glass substrates. To achieve high-definition displays, TFTs with high driving power are required. Polycrystalline silicon, IGZO (Indium Gallium Zinc Oxide), and other materials are used as the channel material for TFTs. Compared to amorphous silicon, polycrystalline silicon and IGZO have higher carrier mobility, resulting in excellent on / off characteristics for the transistors.

[0003] Semiconductor thin films are also expected to be used in 3D-ICs, which enable devices with higher functionality. 3D-ICs are achieved by forming active components such as sensors, amplifiers, and CMOS circuits on the top layer of integrated circuit devices. Therefore, technologies for manufacturing higher-quality semiconductor thin films are required.

[0004] Furthermore, with the diversification of information terminals, demand is growing for flexible displays and computers that are compact, lightweight, consume less power, and can be freely bent. Consequently, there is a need to establish technology for forming high-quality semiconductor thin films on plastic substrates such as PET (Polyethylene terephthalate).

[0005] To form high-quality semiconductor thin films on glass substrates, integrated circuits, or plastic substrates, it is necessary to crystallize the semiconductor films without causing thermal damage to the substrates. Glass substrates used in displays require a process temperature of 400°C or less, integrated circuits require a process temperature of 400°C or less, and PET, a plastic substrate, requires a process temperature of 200°C or less.

[0006] Laser annealing is a technique for crystallizing a semiconductor thin film without thermally damaging the underlying substrate. This method uses pulsed ultraviolet laser light that is absorbed by the overlying semiconductor thin film to suppress damage to the substrate due to thermal diffusion.

[0007] When the semiconductor thin film is silicon, a XeF excimer laser with a wavelength of 351 nm, a XeCl excimer laser with a wavelength of 308 nm, or a KrF excimer laser with a wavelength of 248 nm is used. Compared to solid-state lasers, these ultraviolet gas lasers have the following characteristics: low laser interference and excellent energy uniformity in the laser irradiation surface, making it possible to uniformly anneal a wide area at high pulse energy.

[0008] Prior art literature

[0009] Patent Literature

[0010] Patent Document 1: International Publication No. 2008 / 120785

[0011] Patent Document 2: Japanese Patent Application Laid-Open No. 2013-54315

[0012] Patent Document 3: Japanese Patent Application Laid-Open No. 2017-151259 Summary of the Invention

[0013] The laser annealing device of one aspect of the present disclosure comprises: a laser device that outputs laser light; an optical system that uniformly irradiates a plurality of processed areas arranged along a first direction within a surface of a workpiece and at least a second direction perpendicular to the first direction with laser light; a relative moving device that causes the uniform irradiation area and the workpiece to move relative to each other in the first direction and the second direction, the uniform irradiation area having an arrangement of a plurality of irradiation areas of the laser corresponding to the arrangement of the plurality of processed areas to be uniformly irradiated; and a controller that controls the laser device and the relative moving device so that N is set to an integer greater than 1, and during the Nth scan, a scan is performed in the Nth scanning area of ​​the workpiece so that the uniform irradiation area and the workpiece are relatively moved in the first direction, and the processed areas arranged in a grid pattern along the first direction and the second direction in the Nth scanning area are respectively irradiated with laser light, and after the Nth scan, the uniform irradiation area and the workpiece are relatively moved. The workpiece moves relatively in the second direction, and the scanning target area is changed to the N+1th scanning area. During the N+1th scan, scanning is performed in the N+1th scanning area adjacent to the Nth scanning area of ​​the workpiece and not overlapping with the N scanning area. The laser annealing device further includes: an energy density measuring device, which measures the energy density of at least the second end of the two ends of the unified irradiation area in the second direction, namely, the first end and the second end; and an energy density adjusting device, which adjusts the energy density of at least the first end of the first end and the second end of the unified irradiation area. The controller controls the energy density adjusting device according to the measurement result of the energy density measuring device, and adjusts the energy density of the first end when performing the N+1th scan, so that the energy density of the first end in the N+1th scanning area adjacent to the second end in the N scanning area is close to the energy density of the second end in the N scanning area.

[0014] Another aspect of the present disclosure provides a method for manufacturing an electronic device, comprising: using a laser annealing apparatus to perform multiple scans on a workpiece, including an Nth scan and an N+1th scan, and annealing each of the processed areas of the workpiece to manufacture the electronic device, the laser annealing apparatus comprising: a laser apparatus that outputs laser light; an optical system that uniformly irradiates a plurality of processed areas arranged along at least a second direction of a first direction within a surface of the workpiece and a second direction perpendicular to the first direction with laser light; a relative moving apparatus that causes the uniform irradiation area and the workpiece to move relative to each other in the first direction and the second direction, the uniform irradiation area having an arrangement of a plurality of irradiation areas of the laser corresponding to the arrangement of the plurality of processed areas subjected to uniform irradiation; and a controller that controls the laser apparatus and the relative moving apparatus so that N is set to an integer greater than 1, and in the Nth scan, a scan is performed in the Nth scan area of ​​the workpiece, in which the uniform irradiation area and the workpiece are relatively moved in the first direction, and the Nth scan area is subjected to a scan along the first direction. and the processed areas arranged in a grid pattern in the second direction are irradiated with laser light respectively. After the Nth scan, the unified irradiation area and the processed object are moved relative to each other in the second direction, and the scanned object area is changed to the N+1th scanning area. During the N+1th scan, scanning is performed in the N+1th scanning area adjacent to the Nth scanning area of ​​the processed object and not overlapping with the N scanning area. The laser annealing device also has: an energy density measuring device, which measures the energy density of at least the second end of the two ends of the unified irradiation area in the second direction, i.e., the first end and the second end; and an energy density adjusting device, which adjusts the energy density of at least the first end of the first end and the second end of the unified irradiation area. The controller controls the energy density adjusting device according to the measurement result of the energy density measuring device, and adjusts the energy density of the first end when performing the N+1th scan, so that the energy density of the first end in the N+1th scanning area adjacent to the second end in the N scanning area is close to the energy density of the second end in the N scanning area. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Hereinafter, several embodiments of the present disclosure will be described as simple examples with reference to the accompanying drawings.

[0016] Figure 1 The structure of an exemplary laser annealing apparatus is schematically shown.

[0017] Figure 2 Graph showing the energy density distribution on the mask of the pulse laser light illuminating the mask.

[0018] Figure 3 This is an explanatory diagram illustrating problems of a laser annealing apparatus.

[0019] Figure 4The structure of the laser annealing apparatus according to the first embodiment is schematically shown.

[0020] Figure 5 Another embodiment of the energy density meter is shown.

[0021] Figure 6 Graph showing an example of the angular characteristics of the end energy density.

[0022] Figure 7 Examples of energy density distribution of pulsed laser light in each of the case where the mirror angle is θ1 and the case where the mirror angle is θ2 are shown.

[0023] Figure 8 The operation status of the laser annealing device during workpiece processing is shown.

[0024] Figure 9 This is a flowchart showing an example of the operation of the laser annealing apparatus according to the first embodiment.

[0025] Figure 10 This is an explanatory diagram showing the effects of the first embodiment.

[0026] Figure 11 The structure of a laser annealing apparatus according to Modification 1 of Embodiment 1 is schematically shown.

[0027] Figure 12 An example of a method of measuring the energy density on the mask surface is shown.

[0028] Figure 13 An example of a method of measuring the energy density on a workpiece surface is shown.

[0029] Figure 14 This is a graph showing an example of energy density distribution of pulsed laser light on the mask surface achieved by the operation of the laser annealing apparatus according to Modification 1 of Embodiment 1.

[0030] Figure 15 : is a graph showing an example of the relationship between the reflector angle θ and the energy density da at the A end.

[0031] Figure 16 This is a flowchart showing an example of the operation of the laser annealing apparatus according to the first modification of the first embodiment.

[0032] Figure 17 Effects of the laser annealing apparatus according to Modification 1 of Embodiment 1 are shown.

[0033] Figure 18 The structure of a laser annealing apparatus according to a second modification of the first embodiment is schematically shown.

[0034] Figure 19This is a graph showing an example of energy density distribution of pulsed laser light on the mask surface achieved by the operation of the laser annealing apparatus according to the second modification of the first embodiment.

[0035] Figure 20 Graph showing an example of the relationship between the amount of parallel movement in the Y direction of the high reflective mirror achieved by the mirror actuator and the energy density da at the A end.

[0036] Figure 21 The structure of a laser annealing apparatus according to the second embodiment is schematically shown.

[0037] Figure 22 It is a plan view showing a configuration example of a wire filter and a filter actuator.

[0038] Figure 23 This diagram illustrates the relationship between the wire diameter and shielding ratio of a wire filter.

[0039] Figure 24 This is a graph showing an example of energy density distribution of pulsed laser light on the mask surface achieved by the operation of the second embodiment.

[0040] Figure 25 The structure of a laser annealing apparatus according to Modification 1 of Embodiment 2 is schematically shown.

[0041] Figure 26 1 is a plan view showing a configuration example of a second wire filter and a second filter actuator. Figure 25 Some of the multiple wire filters shown.

[0042] Figure 27 The structure of a laser annealing apparatus according to a second modification of the second embodiment is schematically shown.

[0043] Figure 28 is a top view showing an example of a graduated filter.

[0044] Figure 29 The structure of a laser annealing apparatus according to a third modification of the second embodiment is schematically shown.

[0045] Figure 30 1 is a plan view showing an example of a color separation filter.

[0046] Figure 31 This is a graph showing an example of energy density distribution of illumination light on the mask plane in each of the Nth scan and the (N+1)th scan achieved by the operation of the laser annealing apparatus according to the third modification of the second embodiment.

[0047] Figure 32 This is a plan view showing another embodiment of a dichroic filter that can be used in a laser annealing device.

[0048] Figure 33 The structure of a laser annealing apparatus according to a fourth modification of the second embodiment is schematically shown.

[0049] Figure 34 This is a graph showing an example of energy density distribution of illumination light on the mask plane in each of the Nth scan and the (N+1)th scan achieved by the operation of the laser annealing apparatus according to the fourth modification of the second embodiment.

[0050] Figure 35 Another example of a method for measuring energy density is schematically shown. DETAILED DESCRIPTION

[0051] -Table of contents-

[0052] 1. Overall description of laser annealing equipment

[0053] 1.1 Structure

[0054] 1.2 Action

[0055] 2.Topic

[0056] 3. Implementation Method 1

[0057] 3.1 Structure

[0058] 3.2 Action

[0059] 3.3 Function / Effect

[0060] 3.4 Modification 1

[0061] 3.4.1 Structure

[0062] 3.4.2 Action

[0063] 3.4.3 Function / Effect

[0064] 3.5 Modification 2

[0065] 3.5.1 Structure

[0066] 3.5.2 Action

[0067] 3.5.3 Function / Effect

[0068] 4. Implementation Method 2

[0069] 4.1 Structure

[0070] 4.2 Action

[0071] 4.3 Action / Effect

[0072] 4.4 Modification 1

[0073] 4.4.1 Structure

[0074] 4.4.2 Action

[0075] 4.4.3 Function / Effect

[0076] 4.5 Modification 2

[0077] 4.5.1 Structure

[0078] 4.5.2 Action

[0079] 4.5.3 Function / Effect

[0080] 4.6 Variation 3

[0081] 4.6.1 Structure

[0082] 4.6.2 Action

[0083] 4.6.3 Action / Effect

[0084] 4.6.4 Others

[0085] 4.7 Modification 4

[0086] 4.7.1 Structure

[0087] 4.7.2 Action

[0088] 4.7.3 Action / Effect

[0089] 5. Another method for measuring the energy density of pulsed laser

[0090] 6. Configuration of Multiple Irradiation Areas within a Unified Irradiation Area

[0091] 7. Method for manufacturing electronic devices

[0092] 8. Others

[0093] Below, embodiments of the present disclosure are described in detail with reference to the accompanying drawings. The embodiments described below illustrate several examples of the present disclosure and do not limit the content of the present disclosure. In addition, the structures and actions described in each embodiment are not necessarily all required structures and actions of the present disclosure. In addition, the same reference numerals are given to the same structural elements, and repeated descriptions are omitted.

[0094] 1. Overall description of laser annealing equipment

[0095] 1.1 Structure

[0096] Figure 1The structure of an exemplary laser annealing apparatus is schematically shown. Laser annealing apparatus 10 irradiates an amorphous (non-crystalline) silicon film formed on a glass substrate with ultraviolet-wavelength pulsed laser light, such as an excimer laser, to convert it into polycrystalline silicon. By converting amorphous silicon into polycrystalline silicon, for example, TFTs can be formed. TFTs are used in relatively large liquid crystal displays.

[0097] Laser annealing apparatus 10 includes a laser device 20, an illumination optical system 30, a high-reflection mirror 40, a multi-point processing optical system 50, a stage 60, and a controller 70. A substrate 80 placed on stage 60 is the workpiece to be annealed. Substrate 80 is a glass substrate coated with amorphous silicon. Substrate 80 is sometimes referred to as a workpiece.

[0098] The laser device 20 outputs pulsed laser light of an ultraviolet wavelength capable of annealing amorphous silicon. For example, the laser device 20 is a discharge-excitation excimer laser device using F2, ArF, KrF, XeCl, or XeF as a laser medium.

[0099] The illumination optical system 30 shapes the pulsed laser light so as to uniformly illuminate the mask 52 and guides it to the high-reflection mirror 40. The illumination optical system 30 is configured to include, for example, a fly-eye lens (not shown) and a focusing optical system to uniformly illuminate the mask 52. The focusing optical system may be a combination of a convex lens and a concave lens.

[0100] The high reflective mirror 40 is configured to guide the pulsed laser light shaped by the illumination optical system 30 onto the mask 52 .

[0101] The multi-point processing optical system 50 includes a mask 52 and a microlens array 56 for reducing and projecting the mask pattern onto a substrate 80. The role of the microlens array 56 is not limited to reduction projection, but can also be equal-magnification projection.

[0102] Mask 52 has a plurality of mask pattern openings 53, each of which is configured to resemble the shape of an annealing region on substrate 80. The annealing region is a region where amorphous silicon on substrate 80 is converted to polysilicon. Within the surface of substrate 80, a large number of annealing regions are arranged in a grid pattern at regular intervals in the X and Y directions of the figure. The shape, number, and arrangement of the annealing regions can be designed as appropriate.

[0103] The mask pattern openings 53 are portions of the mask 52 that serve as light passage areas. The plurality of mask pattern openings 53 are arranged at equal intervals in the Y direction of the figure, corresponding to the arrangement of the annealing regions on the substrate 80. Regarding the arrangement of the mask pattern openings 53 in the mask 52, the number of mask pattern openings 53 arranged in the Y direction may be just one (one column) or multiple columns. Considering the productivity and feasibility of the laser annealing apparatus 10, the number of columns is generally arranged in the tens to hundreds. The overall arrangement pattern of the plurality of mask pattern openings 53 formed in the mask 52 is referred to as a mask pattern.

[0104] The lenses 57 of the microlens array 56 are arranged corresponding to the positions of the mask pattern openings 53 .

[0105] The stage 60 is a motorized stage capable of moving the substrate 80, which is the object to be annealed, in the X and Y directions in the figure. The stage 60 may also have an adjustment function in the Z direction. The X and Y directions are parallel to the surface of the substrate 80, with the Y direction being perpendicular to the X direction. The Z direction is perpendicular to the surface of the substrate 80.

[0106] Controller 70 is connected to laser device 20 and stage 60 to synchronously control the output of pulsed laser and the driving of stage 60 in the X and Y directions. Controller 70 can also set the repetition frequency of pulsed laser, adjust the energy, and adjust the position of stage 60 in the Z direction.

[0107] 1.2 Action

[0108] The controller 70 sets the repetition frequency and pulse energy of the pulse laser light for the laser device 20. Furthermore, the controller 70 moves the stage 60 to the annealing start position.

[0109] When the controller 70 instructs the laser device 20 to output laser light, the laser device 20 outputs pulsed laser light at the set repetition frequency and pulse energy. The pulsed laser light output from the laser device 20 is shaped by the illumination optical system 30 into a pulsed laser light having a substantially rectangular cross-sectional profile that is long in the Y direction on the mask 52.

[0110] Figure 2 Graph 1 is a graph showing the energy density distribution of the pulse laser light illuminating the mask 52 on the mask 52. Figure 2 As shown, the pulse laser light is homogenized so as to have a substantially uniform energy density distribution within the range where the mask pattern on the mask 52 exists.

[0111] The pulsed laser light shaped and uniformed by the illumination optical system 30 passes through the mask pattern opening 53 of the mask 52. At this time, the pulsed laser light is shaped into a shape similar to the shape of the region of the substrate 80 where the amorphous silicon is to be converted into polysilicon.

[0112] After passing through the mask pattern openings 53 of the mask 52, the pulsed laser light is irradiated onto a predetermined area of ​​the substrate 80 at a predetermined energy density via the microlens array 56, thereby annealing the irradiated area. In the area of ​​the substrate 80 irradiated with the pulsed laser light, the amorphous silicon melts and crystallizes, forming polycrystalline silicon.

[0113] The controller 70 stops the laser output after waiting for the number of laser irradiations or the irradiation time for each annealing region to be sufficiently annealed.

[0114] Then, the controller 70 moves the stage 60 in the −X direction by a predetermined amount to move the stage 60 to the next annealing position, and repeats the same operation as above.

[0115] In this way, annealing is completed on the numerous annealing regions arranged in the strip-shaped region along the X-direction of substrate 80. The process of irradiating the pulsed laser light while moving the irradiation region relative to substrate 80 in the X-direction and annealing the strip-shaped region along the X-direction of substrate 80 is called scanning. The width of the scan depends on the number of mask pattern openings 53 arranged in the Y-direction. The strip-shaped region to be scanned is called a scanning region. The scanning region includes numerous annealing regions arranged in a grid pattern at regular intervals in both the X- and Y-directions.

[0116] When scanning of one scan area is completed, the controller 70 moves the stage 60 in the -Y direction, changes the scanned area, and scans another scan area adjacent to the already processed scan area. In this case, N is an integer greater than 1, and the end of the Nth scan is adjacent to the end on the opposite side of the (N+1)th scan.

[0117] By repeating the above steps and performing multiple scans, including N scans and N+1 scans, the necessary annealing process is completed on the substrate 80. The annealed portion (annealed region) on the substrate 80 becomes polysilicon and functions as part of a TFT. Annealing the substrate 80 is sometimes referred to as "workpiece processing."

[0118] 2.Topic

[0119] Figure 3 It is an explanatory diagram showing a problem of the laser annealing apparatus 10 . Figure 3 The figure above shows an example of the configuration pattern of the annealing area 82 on the substrate 80. Figure 3 The lower graph shows the distribution of energy density of the pulse laser irradiated to each annealing region 82 on the substrate 80 .

[0120] For simplicity, an example is shown here in which the mask 52 has a mask pattern with seven mask pattern openings 53 arranged in the Y direction, and three rows of these seven mask pattern openings 53 arranged in the X direction, for a total of 3 × 7 = 21 mask pattern openings 53. Of course, the present invention is not limited to this example. The number of mask pattern openings 53 arranged in each row along the Y direction can be appropriately selected based on the laser device 20 and annealing conditions. The number of rows in the X direction is designed based on the number of pulses (pulses) of pulsed laser light irradiated onto one annealing region 82. Figure 3 This is an example of the case where one annealing region 82 is irradiated with pulse laser light three times (three pulses).

[0121] The 3×7 annealing regions 82 on the substrate 80 are collectively irradiated with pulse laser light by the multi-point processing optical system 50 . Figure 3 The area enclosed by the dotted line in the above figure is an example of a uniform irradiation area 84. The uniform irradiation area 84 has a pattern of 3×7 irradiation areas, and these 3×7 irradiation areas are based on the beam group of pulsed laser beams corresponding to the arrangement of 3×7 annealing regions 82. In this way, the laser annealing apparatus 10 irradiates the plurality of local areas (plurality of annealing regions 82) discretely arranged within the surface of the substrate 80 with pulsed laser light using the multi-point processing optical system 50.

[0122] The laser annealing apparatus 10 performs scanning by moving the uniform irradiation region 84 relative to the substrate 80 in the X direction. Figure 3 The above figure schematically shows a situation where the scanning of the Nth scan is completed and the scanning of the N+1th scan is started. The scanning area of ​​the N+1th scan, that is, the N+1th scanning area, is an area adjacent to the scanning area of ​​the Nth scan, that is, the Nth scanning area, and does not overlap with the Nth scanning area. That is, the scanning areas of each scan are arranged in the Y direction in a manner that does not overlap with each other. Here, overlap means that the pulse laser having an energy density above the threshold value that causes silicon modification is irradiated to the same area in different scans. The modification of silicon in this case includes melting and / or recrystallization. Therefore, non-overlap also includes the pulse laser having an energy density that is not causing silicon modification being irradiated to the same area in different scans.

[0123] Figure 3 The graph below shows the energy density distribution of the pulsed laser irradiated to the following position: Figure 3 In the arrangement pattern of the annealing regions shown in the upper figure, the positions of the annealing regions along the Y direction are indicated by the two-dot chain line in the second row from the bottom. Figure 3 The horizontal axis of the lower figure shows the Y-direction position on the substrate 80 .

[0124] As described above, the pulsed laser light is shaped by the illumination optical system 30 to have a substantially uniform energy density distribution in the Y direction. However, depending on the adjustment state, a difference in energy density may occur between the two Y-direction ends of the uniform irradiation area 84, namely, end A and end B. Furthermore, this difference may vary over time. For example, the energy density difference between the two ends, for example, end B in the Nth scan and end A in the adjacent (N+1) scan, results in a discontinuous difference ΔEG in the energy density of the pulsed laser light.

[0125] That is, in Figure 3 In the example, a discontinuous difference ΔEG occurs between the energy density of the pulsed laser light irradiated at the right end (end B) of the Nth scan and the energy density of the pulsed laser light irradiated at the left end (end A) of the N+1th scan. Similarly, a discontinuous energy density difference also occurs between the right end of the N+1th scan and the left end of the N+2th scan.

[0126] Depending on the magnitude of this difference ΔEG, when the annealed substrate 80 is operated as an FPD (flat panel display), it may appear as "streaks" or "unevenness." This is believed to be caused by unevenness in the degree of silicon (Si) crystallization due to differences in energy density. This defect is particularly noticeable to the naked eye in display elements used in displays, creating a significant problem. Consequently, it can sometimes contribute to reduced yields.

[0127] Specifically, when annealing substrate 80 by performing multiple scans by dividing the scanning area in the Y direction, the discontinuous energy density difference at the joints between adjacent scanning areas is likely to affect FPD quality. Conventional methods have improved the uniformity of illumination in the Y direction by adjusting the elements of the illumination optical system 30 to achieve uniform illumination at both ends. However, this requires unnecessarily strict uniformity, and it is difficult to maintain illumination uniformity over a long period of time.

[0128] 3. Implementation Method 1

[0129] 3.1 Structure

[0130] Figure 4 The structure of the laser annealing apparatus 11 according to the first embodiment is schematically shown. Figure 4 The structure shown is Figure 1 The differences are explained. Figure 4 In the laser annealing apparatus 11 shown, the illumination optical system 30 is adjusted or configured so that the energy density gradually decreases at the ends in the Y direction of the illumination light illuminating the mask 52. The laser annealing apparatus 11 further includes an energy density meter 62 and a mirror actuator 42.

[0131] The energy density meter 62 measures the energy density of the laser light at the ends of the plurality of annealing regions 82 arranged in the Y direction within one scan. The energy density may be measured only near the two ends of the unified irradiation region 84 (one scan region) in the Y direction. Figure 4 In order to measure the energy density of each end A and end B, an energy density measuring device 62 is arranged at a position corresponding to each end. Figure 4 In the case of a method of measuring only the end of the uniform irradiation area 84 , the energy density measuring device 62 may be configured by combining an energy meter having sensitivity in the wavelength band of the pulsed laser light and an objective optical system, for example.

[0132] Alternatively, the energy density measuring device 62 may be a system that uses a beam profiler or the like to measure the energy density of the entire unified irradiation region 84 .

[0133] Figure 5 Another form of the energy density meter 62 is shown. Figure 4 The structure shown in the figure is adopted Figure 5 The structure shown. Figure 5 As shown, when measuring the energy density of the entire uniform irradiation area 84, the energy density meter 62 may be a combination of a beam analyzer capable of measuring using the wavelength of pulsed laser light and an optical system for dimming and enlarging and reducing the beam size.

[0134] The mirror actuator 42 includes a rotation mechanism that rotates the high-reflection mirror 40. This mechanism is configured to adjust the angle at which the pulsed laser light shaped by the illumination optical system 30 illuminates the mask 52. The mirror actuator 42 can be, for example, a rotary stage operated by a stepping motor or a piezoelectric actuator. By driving the mirror actuator 42, the reflection angle of the high-reflection mirror 40 can be changed. Specifically, driving the mirror actuator 42 causes the energy density distribution of the pulsed laser light on the mask 52 to change.

[0135] The energy density meter 62 and the mirror actuator 42 are each connected to a controller 70. The controller 70 controls the mirror actuator 42 based on the measurement result of the energy density meter 62.

[0136] 3.2 Action

[0137] Before workpiece processing begins, the energy density at both ends of the uniform irradiation area 84 in the Y direction, namely, end A and end B, is measured using the energy density meter 62. The controller 70 rotates the mirror actuator 42 in a predetermined direction to measure the energy density at both ends. The controller 70 sequentially changes the rotation angle of the mirror actuator 42 within a predetermined angular range, repeatedly measuring the energy density at both ends at each rotation angle, thereby obtaining an angular characteristic of the energy density at the ends. The predetermined angular range preferably includes both rotation angles in the +θ direction and the -θ direction, from a reference rotation angle corresponding to the standard position of the high-reflection mirror 40.

[0138] Figure 6 This is a graph showing an example of the angular characteristics of the energy density at the end. The horizontal axis shows the rotation angle of the mirror actuator 42, and the vertical axis shows the energy density of the pulsed laser. Hereinafter, the rotation angle of the mirror actuator 42 will be referred to as the "mirror angle."

[0139] Let the energy densities at ends A and B, respectively, be Ea1 and Eb1 when the reflector angle is θ1, and let the energy densities at ends A and B, respectively, be Ea2 and Eb2 when the reflector angle is θ2. In this example, Eb1 = Et, Et ≒ Ea2, and Ea1 ≒ Eb2 hold.

[0140] On the other hand, in this example, there is a mirror angle θc at which the energy density is equal at both ends A and B. Thus, even when there is a mirror angle θc at which the energy density is equal at both ends A and B, it is possible to perform multiple scans continuously while fixing the mirror angle at θc.

[0141] Figure 7 Examples of energy density distribution of pulsed laser light in each of the case where the mirror angle is θ1 and the case where the mirror angle is θ2 are shown. Figure 7 The horizontal axis shows the position in the Y direction. Figure 7 As shown, the energy density distribution of the pulsed laser light in the irradiation area changes depending on the mirror angle.

[0142] Since the energy density near each of the A end and the B end changes, the energy density at each end can be adjusted by changing the angle of the reflector.

[0143] Then, during workpiece processing, for example, the N-th scan, that is, the N-th scan, is performed with the mirror angle fixed at θ1.

[0144] Then, the mirror angle is set to θ2, and the position of the high reflector 40 is fixed, so that the energy density at the A end in the next scan (N+1 scan) is consistent with the energy density Et at the B end in the N scan. In addition, "consistent" can also include an allowable range that is regarded as substantially consistent.

[0145] Thereafter, similarly, the mirror angle is switched from θ1 to θ2 to θ1 , ... for each scan, and the entire surface of the workpiece is processed.

[0146] Figure 8 The figure shows the operation of the laser annealing apparatus 11 during workpiece processing. The controller 70 controls the mirror actuator 42 so that the rotation angle is switched for each scan. Specifically, the controller 70 controls the mirror actuator 42 so that the mirror angle is θ1 during the Nth scan, the mirror angle is θ2 during the following N+1th scan, the mirror angle is θ1 during the following N+2th scan, and so on.

[0147] Figure 9 This is a flowchart showing an example of the operation of the laser annealing device 11 according to the first embodiment. Figure 5 The example of the energy density measuring device 62 is shown. The mirror actuator 42 is one form of a light distribution adjuster that adjusts the energy density distribution.

[0148] In step S12, the controller 70 changes the parameter xi of the light distribution adjuster and measures the beam profile with the energy density meter 62 to obtain the relationship between the energy density at the end A and the end B and xi (relationship i). The parameter xi in the reflector actuator 42 is the reflector angle θ. By executing step S12, for example, Figure 6 This kind of relationship. Figure 6 The information on the angular characteristics of the end energy density shown is an example of “relationship information” in the present disclosure. The parameter xi and the mirror angle θ are each an example of “adjustment amount” in the present disclosure.

[0149] exist Figure 9 In step S14, the controller 70 sets a target average energy density in the mask surface according to the annealing process.

[0150] In step S16 , the controller 70 carries the substrate 80 , which is a workpiece, onto the stage 60 .

[0151] In step S18 , the controller 70 sets a variable n for counting the number of scans to an initial value of “1”, and starts workpiece processing.

[0152] In step S20 , the controller 70 starts the N-th scanning operation.

[0153] In step S22 , the controller 70 predicts the energy density at the B end according to the relationship i.

[0154] In step S24, the controller 70 determines a parameter xi that makes the energy density at the A end of the N+1th scan equal to the energy density at the B end of the Nth scan based on the relationship i. Determining the parameter xi that makes the energy density at the A end of the N+1th scan equal to the energy density at the B end of the Nth scan is an example of controlling so that the energy density at the A end of the N+1th scan approaches the energy density at the B end of the Nth scan.

[0155] In step S26, after the Nth scan is completed, the controller 70 proceeds to step S28. In step S28, the controller 70 determines whether the variable n has reached a predetermined maximum value nmax. nmax may be, for example, the number of scans required to process the entire workpiece surface.

[0156] If the result of step S28 is "No," the controller 70 proceeds to step S30, increments the variable n, and returns to step S20. The controller 70 repeats steps S20 through S30 until the variable n reaches nmax. If the variable n and nmax are equal, and the result of step S28 is "Yes," the controller 70 proceeds to step S32, terminating workpiece processing.

[0157] Then, in step S34, the controller 70 unloads the processed workpiece from the stage 60. When processing the next workpiece, after step S34, the controller 70 returns to step S12 and repeats the processes of steps S12 to S34.

[0158] After step S34, if there is no need to process the next workpiece, the controller 70 may also end the process. Figure 9 Flowchart of the process.

[0159] in addition, Figure 9 While an example is shown in which the process starts from step S12 for each workpiece, the timing of executing step S12 is not limited to this example. For example, step S12 may be executed only when the laser annealing apparatus 11 is activated, or step S12 may be executed after the number of processed workpieces is counted and a predetermined number of workpieces is reached, or step S12 may be executed periodically according to a predetermined maintenance cycle based on, for example, operating time management.

[0160] Alternatively, step S12 may be performed when inspecting a processed workpiece or the like and obtaining an inspection result that indicates a concern about "streaks" or "unevenness," or step S12 may be performed at an appropriate timing based on an instruction input from the user.

[0161] In addition, Figure 9 After step S34 in the flowchart of FIG. 1 , when a new workpiece is processed, the processing of step S14 may be skipped if the annealing process is not changed.

[0162] 3.3 Function / Effect

[0163] Figure 10 : is an explanatory diagram showing the effect of embodiment 1. Figure 3 As can be seen from the comparison with the following figure, according to Embodiment 1, the difference in energy density between the B end during the N scan and the A end during the adjacent N+1 scan can be reduced. As a result, when the annealed substrate 80 is used as an FPD, for example, visual "streaks" and "unevenness" are less likely to be detected. This can improve the FPD yield.

[0164] End A in Embodiment 1 is an example of the “first end” in the present disclosure, and end B is an example of the “second end” in the present disclosure. Annealing region 82 is an example of the “processed region” in the present disclosure. The direction parallel to the X direction is an example of the “first direction” in the present disclosure, and the direction parallel to the Y direction is an example of the “second direction” in the present disclosure. The high reflective mirror 40 and the multi-point processing optical system 50 are examples of the “optical system” in the present disclosure. The high reflective mirror 40 is an example of the “reflecting mirror” in the present disclosure. The stage 60 is an example of the “relative moving device” in the present disclosure. The energy density meter 62 is an example of the “energy density measuring device” in the present disclosure. Figure 4 Of the two energy density meters 62 shown, the right energy density meter 62 is an example of a "first end meter" in the present disclosure, and the left energy density meter 62 is an example of a "second end meter" in the present disclosure. The mirror actuator 42 is an example of an "energy density adjustment device" in the present disclosure.

[0165] 3.4 Modification 1

[0166] 3.4.1 Structure

[0167] Figure 11 The structure of a laser annealing apparatus 11A according to a first modification of the first embodiment is schematically shown. Figure 11 The structure shown is Figure 4 The differences are explained.

[0168] Figure 11 The laser annealing apparatus 11A shown has an energy density measuring device 63 that can measure energy density even during workpiece processing. The energy density can be measured on either the mask surface or the workpiece surface. Figure 11The energy density meter 63 shown measures the energy density on the mask surface. The energy density meter 63 may be a combination of an energy meter and an objective optical system to measure the energy density at the end of the substantially rectangular illumination area of ​​the pulsed laser light illuminating the mask 52 .

[0169] like Figure 12 As shown, a movable mirror unit 631 can also be used when calculating energy density from an oblique direction. The movable mirror unit 631 is configured to move an inclined movable mirror 633 to a position deviating from the irradiation range and to a position on the mask 52. Only when measuring light intensity distribution, the movable mirror 633 is moved on the mask 52 within the irradiation range, and the light reflected by the movable mirror 633 is guided to the energy density meter 63. The energy density meter 63 can be arranged conjugately with respect to the objective optical system 632 and the mask surface, enabling measurement of the energy density distribution at the irradiation end surface.

[0170] When there is a pattern on the mask surface and the energy density distribution can be measured by detecting the scattered light, it can also be configured such that the movable mirror unit 631 is not involved. Figure 11 In this way, the energy density meter 63 is arranged to detect directly from obliquely above.

[0171] Figure 13 An example of a method for measuring the energy density on the workpiece surface is shown. Figure 11 The structure is adopted Figure 13 The structure shown. Figure 13 The energy density measuring device 63 shown in FIG. 1 may be, for example, a radiation thermometer. Figure 13 Thus, a configuration may be adopted in which the substrate 80 is actually irradiated with pulse laser light to generate heat and increase the temperature of the substrate 80 , and the temperature of the annealing region 82 is measured by a radiation thermometer.

[0172] Figure 14 Graph showing an example of energy density distribution of pulsed laser light on the mask surface achieved by the operation of the laser annealing apparatus 11A. Figure 14 An example of the energy density on the mask surface when the mirror actuator 42 is controlled so that the energy density ED(N, B) at the B end of the Nth scan and the energy density ED(N+1, A) at the A end of the N+1th scan are roughly consistent is shown.

[0173] In order to easily adjust the energy density, in the laser annealing apparatus 11A, as shown in FIG. Figure 14 The illumination optical system 30 is adjusted so that the energy density of the Y-direction end portion of the illumination light on the mask 52 gradually decreases. This distribution can be easily achieved because the end portion enters the boundary region of the end portion of the uniformly illuminated region.

[0174] 3.4.2 Action

[0175] In the Nth scan, the controller 70 obtains and stores the energy density of the pulsed laser light at the B end of the annealing region during the annealing process via the energy density meter 63. That is, the energy density meter 63 performs measurement in the Nth scan operation.

[0176] In the (N+1)th scan, the controller 70 controls the mirror actuator 42 so that the energy density during annealing of the end portion A adjacent to the end portion B in the (N)th scan becomes the energy density measured at the end portion B in the (N)th scan. Furthermore, the energy density at the end portion B in the (N+1)th scan is also measured at this time for use in subsequent adjustments.

[0177] When the mirror actuator 42 is driven, the energy density distribution of the pulsed laser light irradiated onto the mask 52 changes.

[0178] Figure 15 is a graph showing an example of the relationship between the reflector angle θ and the energy density da at the end A. For example, in the case of Figure 15 When the high reflective mirror 40 is rotated in the -θ direction, the energy density at the end A can be increased. Conversely, when the high reflective mirror 40 is rotated in the +θ direction, the energy density at the end A can be reduced.

[0179] The controller 70 stores Figure 15 The controller 70 drives the mirror actuator 42 to realize the energy density at the end B of the Nth scan measured by the energy density meter 63 at the end A of the N+1th scan. Figure 15 Such a relationship between the rotation angle and the energy density can be obtained from data previously measured through experiments, and can be given by an approximate formula, for example. The controller 70 may also include a memory for storing this relationship.

[0180] In addition, although Figure 11 Although not shown, the laser annealing apparatus 11A may also include an energy density meter for measuring the energy density of the A end portion.

[0181] The controller 70 stops the laser output after waiting for the number of laser irradiations or the irradiation time for sufficiently annealing the annealing region.

[0182] Then, the controller 70 moves the stage 60 in the −X direction by a predetermined amount to move the stage 60 to the annealing start position of the next irradiation region, and repeats the same operation as described above.

[0183] After the N+2-th scan, the same operation is repeated, and the annealing process is completed for all the annealing regions 82 in the necessary range on the substrate 80 .

[0184] Figure 16 This is a flowchart showing an example of the operation of the laser annealing apparatus 11A according to the first modification of the first embodiment. Figure 16 Flowchart of Figure 9 The differences are explained. Figure 16 Flowchart instead of Figure 9 The step S22 includes the step S23.

[0185] In step S23, the controller 70 measures the energy density of the B end portion by the energy density measuring device 63 during the workpiece processing. After step S23, the controller 70 proceeds to step S24. Figure 9 The flowchart is the same as

[0186] 3.4.3 Function / Effect

[0187] Figure 17 The following illustrates the effects of the laser annealing apparatus 11A according to Modification 1. According to Modification 1, the controller 70 controls the mirror actuator 42 so that the energy density during annealing of the end portion A of the N+1th scan, which is adjacent to the end portion B of the Nth scan, approaches the energy density measured at the end portion B of the Nth scan. This reduces the difference in energy density between adjacent ends.

[0188] As a result, when the annealed substrate is operated as an FPD, "streaks" and "unevenness" are less likely to be visually recognized, thereby improving the yield of FPDs.

[0189] 3.5 Modification 2

[0190] 3.5.1 Structure

[0191] Figure 18 The structure of a laser annealing apparatus 11B according to a second modification of the first embodiment is schematically shown. Figure 18 The structure shown is Figure 13 The differences are explained. Figure 18 The laser annealing device 11B shown replaces Figure 13 The mirror actuator 42 is replaced with a linear-acting mirror actuator 43. That is, the mirror actuator 43 moves the high-reflection mirror 40 in parallel in the Y direction instead of rotating it.

[0192] The mirror actuator 43 is configured to adjust the position of the mask 52 when the pulsed laser light shaped by the illumination optical system 30 illuminates it. The mirror actuator 43 may be, for example, a linear motion stage driven by a linear motor, a stepping motor, or a piezoelectric actuator, or may include a linear guide, a ball screw, or the like. The mirror actuator 43 is an example of a "mirror moving mechanism" in this disclosure.

[0193] The illumination optical system 30 shapes the pulsed laser light so as to illuminate the mask 52 and guides it to the high-reflection mirror 40. At this time, the energy density at the ends in the Y direction on the mask 52 is adjusted so that the energy density is applied to the ends of the irradiation range and becomes a distribution that shows a decreasing characteristic toward the outside of the irradiation area.

[0194] Figure 19 Graph showing an example of energy density distribution of pulsed laser light on the mask surface achieved by the operation of the laser annealing apparatus 11B. Figure 19 The following shows an example of energy density on the mask surface when the mirror actuator 43 is controlled so that the energy density ED(N, B) at the B end of the Nth scan and the energy density ED(N+1, A) at the A end of the N+1th scan are substantially equal. In the N+1th scan, the mirror actuator 43 is controlled to change the energy density distribution from the dotted line to the solid line. Figure 19 In the figure, the difference in energy density is emphasized for the sake of explanation. In reality, the difference in energy density between the end and the center is set to such a level that even considering the movable range of the high reflective mirror 40, it will not be visually recognized as "uneven" when operating as an FPD.

[0195] replace Figure 18 The energy density meter 63 shown is as follows Figure 11 In that way, a method of measuring the energy density on the mask surface may also be adopted.

[0196] 3.5.2 Action

[0197] When the mirror actuator 43 is driven, the energy density distribution of the pulse laser light irradiated onto the mask 52 changes. Figure 20 is a graph showing an example of the relationship between the parallel movement amount of the high reflective mirror 40 in the Y direction and the energy density da at the end A, which is achieved by the reflective mirror actuator 43. Figure 20 As shown, when the high reflective mirror 40 is parallel moved in the -Y direction, the energy density at the end A can be increased. Conversely, when the high reflective mirror 40 is parallel moved in the +Y direction, the energy density at the end A can be reduced.

[0198] 3.5.3 Function / Effect

[0199] According to the laser annealing device 11B, the Figure 11 The same effect as the laser annealing device 11A. Figure 18 The structure of the laser annealing device 11B shown in FIG. Figures 5 to 10 The control of the mirror actuator 42 is the same as that described in the previous section. In this case, the mirror angles θ1 and θ2 are respectively rewritten as the mirror positions y1 and y2. The mirror positions y1 and y2 are Figure 18 The Y-direction position of the high reflective mirror 40 is shown.

[0200] 4. Implementation Method 2

[0201] 4.1 Structure

[0202] Figure 21 The structure of the laser annealing apparatus 12 according to the second embodiment is schematically shown. Figure 21 The structure shown is Figure 11 The differences are explained. Figure 21 The laser annealing device 12 shown replaces Figure 11 The mirror actuator 42 has a wire filter 90 and a filter actuator 96. Figure 22 1 is a plan view showing a configuration example of the wire filter 90 and the filter actuator 96 .

[0203] The wire filter 90 has a structure in which one or more wires 91 are arranged along the X direction in the optical path on the upstream side of the mask 52. For simplicity, an example of the wire filter 90 is shown here in which a single wire 91 is supported by a filter frame 92. The wire filter 90 blocks a portion of the pulsed laser light incident on the mask 52.

[0204] The material of the electric wire 91 can be metal, fiber, etc. It is preferable that the electric wire 91 is made of a rust-proof material, for example, a stainless steel electric wire.

[0205] The filter actuator 96 is a unit that moves the wire filter 90. The filter actuator 96 includes a Y-direction movement filter actuator 97 that moves the wire filter 90 in the Y direction and a Z-direction movement filter actuator 98 that moves the wire filter 90 in the Z direction.

[0206] The wire filter 90 is supported by a filter actuator 97 and is arranged in the optical path on the upstream side of the mask 52 , for example, in the optical path between the high reflection mirror 40 and the mask 52 .

[0207] Each of the filter actuators 97 and 98 may be a direct-acting stage driven by, for example, a linear motor, a stepping motor, or a piezoelectric actuator, or may include a linear guide, a ball screw, etc. Each of the filter actuators 97 and 98 is connected to the controller 70 .

[0208] Figure 23 This is an explanatory diagram for deriving the relationship between the wire diameter and the shielding ratio of a wire filter. Figure 23 The meanings of the symbols shown are as follows.

[0209] ψ: estimated angle of microlens

[0210] L: distance between microlens and wire

[0211] W: wire diameter

[0212] The shielding ratio Rw of the wires in the image of the microlens array 56 in the case of equal-magnification transfer can be derived from the following formula. As can be seen from the following formula, the shielding ratio Rw of the wires can be adjusted by changing the distance L between the microlenses and the wires. Therefore, the energy density can be adjusted by adjusting the Z-direction position of the wire filter 90.

[0213] Rw=2WLtanψ / {π(Ltanψ) 2}=2W / (πLtanψ)

[0214] 4.2 Action

[0215] The controller 70 uses the energy density measuring device 63 (see Figure 21 ) measures the energy density distribution on the mask surface, and adjusts the Z-direction and Y-direction positions of the wire filter 90 so that the energy densities at the right end (end B) and the left end (end A) of the area used for illumination light illuminating the mask 52 are substantially equal. Adjustment of the Z-direction position can be used to adjust the energy density, and adjustment of the Y-direction position can be used to adjust the position within the illumination light to reduce the energy density.

[0216] The controller 70 can also adjust the position of the wire filter 90 while measuring the energy density through the energy density meter 63 during workpiece processing, and can also pre-store the relationship between the Z-direction position and Y-direction position of the wire filter 90 and the energy density change. After measuring the energy density, the wire filter 90 is positioned at the optimal position through calculation.

[0217] Figure 24 This is a graph showing an example of energy density distribution of pulsed laser light on the mask surface achieved by the operation of the second embodiment. Figure 24 An example of energy density on the mask surface when the wire filter 90 is controlled so that the energy density ED(N, B) at the B end of the Nth scan and the energy density ED(N+1, A) at the A end of the N+1th scan are substantially equal is shown.

[0218] Figure 24The graph represented by the dotted line in the N+1th scan shows the energy density distribution in the mask surface when the wire filter 90 is not used. By using the wire filter 90 in the N+1th scan, Figure 24 The solid line represents the energy density distribution ED(N+1). Figure 24 The “use area” shown is an area where the mask pattern of the mask 52 exists in the illumination range of the illumination light, and is an effective use area used for illumination by the mask 52 .

[0219] In addition, Figures 21 to 24 In the second embodiment shown, the wire filter 90 is arranged only on the A end side ( Figure 21 ), however, a wire filter may be configured on both the B end side (right side) and the A end side (left side) to smoothly connect the energy density distribution at the adjacent A end and B end.

[0220] In addition, Figure 21 In the embodiment, the energy density is measured at the position of the mask surface, but the energy density can also be measured at the position of the workpiece surface. That is, the energy density meter 63 can be replaced or based on this. Figure 4 The energy density measuring device 62 shown measures the energy density distribution on the workpiece surface.

[0221] In the second embodiment, the wire position is adjusted before the workpiece is processed. However, in order to suppress the fluctuation of the energy density distribution during the workpiece processing, the wire position may be adjusted during the workpiece processing.

[0222] 4.3 Action / Effect

[0223] According to the laser annealing apparatus 12 of the second embodiment, the same effects as those of the first embodiment and its first and second modifications can be obtained.

[0224] The filter actuators 97 and 98 in the second embodiment are examples of “actuators for adjusting the position of the filter” in the present disclosure.

[0225] 4.4 Modification 1

[0226] 4.4.1 Structure

[0227] Figure 25 The structure of a laser annealing apparatus 12A according to a first modification of the second embodiment is schematically shown. Figure 25 The structure shown is Figure 21 The differences are explained.

[0228] Figure 25 The laser annealing apparatus 12A shown replaces Figure 21The optical filter 90 and the filter actuator 96 include a first optical filter 90A, a second optical filter 90B, and a third optical filter 90C, and a first filter actuator 96A, a second filter actuator 96B, and a third filter actuator 96C.

[0229] The first wire filter 90A, the second wire filter 90B, and the third wire filter 90C may be configured to shield the center portion and the B end portion of the mask 52, respectively. Figure 25 As shown, the first wire filter 90A covers at least the B end. Alternatively, the first wire filter 90A may cover the center of the mask 52. The second wire filter 90B covers at least the center of the mask 52. The third wire filter 90C covers at least the A end of the mask 52. Alternatively, the third wire filter 90C may cover the center of the mask 52.

[0230] The first electric wire filter 90A is supported by the first filter frame 92A in a state where a plurality of electric wires 91 are arranged parallel to the X direction. The first electric wire filter 90A is supported by the first filter actuator 96A.

[0231] Similarly, the second wire filter 90B and the third wire filter 90C are supported by a second filter frame 92B and a third filter frame 92C, respectively, with a plurality of wires 91 arranged parallel to the X direction. The second wire filter 90B is supported by a second filter actuator 96B, and the third wire filter 90C is supported by a third filter actuator 96C.

[0232] The first filter actuator 96A is a filter actuator that moves the first wire filter 90A in the Y direction. Similarly, the second filter actuator 96B is a filter actuator that moves the second wire filter 90B in the Y direction, and the third filter actuator 96C is a filter actuator that moves the third wire filter 90C in the Y direction.

[0233] Each of the first filter actuator 96A, the second filter actuator 96B, and the third filter actuator 96C may be a linear motion stage driven by, for example, a linear motor, a stepping motor, or a piezoelectric actuator, and may include a linear guide, a ball screw, or the like.

[0234] like Figure 25 As shown, the first filter actuator 96A, the second filter actuator 96B, and the third filter actuator 96C are each connected to the controller 70 .

[0235] The controller 70 controls the output laser energy of the laser device 20 in conjunction with the control of the first filter actuator 96A, the second filter actuator 96B, and the third filter actuator 96C.

[0236] Figure 26 1 is a plan view showing a configuration example of a second wire filter 90B and a second filter actuator 96B. The second wire filter 90B is Figure 25 Some of the multiple wire filters shown. Figure 26 As shown, the plurality of electric wires 91 are arranged in parallel along the X direction.

[0237] 4.4.2 Action

[0238] If the energy density at end A needs to be increased, the controller 70 sends an instruction to increase the output laser energy to the laser device 20. The controller then controls the first filter actuator 96A to insert the first wire filter 90A, which shields the center portion and end B of the mask 52, into the optical path.

[0239] Furthermore, the controller 70 may control at least one of the second filter actuator 96B and the third filter actuator 96C as needed, in addition to controlling the first filter actuator 96A, to insert at least one of the second wire filter 90B and the third wire filter 90C into the optical path.

[0240] 4.4.3 Function / Effect

[0241] According to this modification 1, the degree of freedom in controlling the energy density at the A end portion is improved.

[0242] 4.5 Modification 2

[0243] 4.5.1 Structure

[0244] Figure 27 The structure of a laser annealing apparatus 12B according to a second modification of the second embodiment is schematically shown. Figure 27 The structure shown is Figure 21 The differences are explained. Figure 27 The laser annealing apparatus 12B includes a gradient filter 93 instead of the wire filter 90 .

[0245] Figure 28This is a top view showing an example of a graduated filter 93. Graduated filter 93 is constructed, for example, by coating a portion of a transparent substrate with a material that is opaque to the laser light wavelength or a material that partially transmits the pulsed laser light. Specifically, graduated filter 93 is constructed from a base material that is transparent to the laser wavelength, and coated with a material that is opaque to the laser wavelength or a material that partially transmits the laser light, so as to create a continuous transmittance distribution. Alternatively, graduated filter 93 can be constructed from a material that has a predetermined transmittance per unit length for the laser wavelength, with the thickness of the material varying continuously depending on the location.

[0246] 4.5.2 Action

[0247] The operation of the laser annealing device 12B is similar to Figure 21 The operation of the laser annealing device 12 is the same.

[0248] 4.5.3 Function / Effect

[0249] according to Figure 27 and Figure 28 In the embodiment shown, when the energy density of the end portion of the illumination light is adjusted, the energy density difference between the irradiation areas around the end portion can be alleviated.

[0250] 4.6 Variation 3

[0251] 4.6.1 Structure

[0252] Figure 29 The structure of a laser annealing apparatus 12C according to a third modification of the second embodiment is schematically shown. Figure 29 The structure shown is Figure 21 The differences are explained. Figure 29 The laser annealing apparatus 12C includes a color separation filter 94 instead of the wire filter 90 . Figure 30 1 is a plan view showing an example of the color separation filter 94 .

[0253] The dichroic filter 94 is an optical element coated with a dichroic film. The dichroic filter 94 is arranged on the optical path of the pulsed laser light that has been parallelized by the illumination optical system 30. The dichroic filter 94 has a characteristic in which the transmittance changes depending on the incident angle of the incident laser light.

[0254] The filter actuator 96 includes a rotation mechanism 99 that can adjust the angle of the color separation filter 94 relative to the laser beam path. The rotation mechanism 99 has a rotation axis parallel to the X-axis. The rotation mechanism 99 is connected to the controller 70.

[0255] The filter actuator 96 includes a Y-direction movement filter actuator 97 and a Z-direction movement filter actuator 98, which are capable of adjusting the position of the dichroic filter 94 relative to the laser path. The Y-direction movement filter actuator 97 and the Z-direction movement filter actuator 98 each include a linear motion stage.

[0256] The filter actuator 96 is an example of an “actuator” in the present disclosure that adjusts the position and angle of the filter.

[0257] 4.6.2 Action

[0258] The controller 70 can control the rotation mechanism 99 to adjust the tilt angle of the dichroic filter 94. By tilting the dichroic filter 94 from the horizontal plane, the angle of incidence of the pulsed laser light incident on the dichroic filter 94 can be changed, and the overall amount of laser light passing through the dichroic filter 94 can be changed.

[0259] Figure 31 Graph showing an example of energy density distribution of illumination light on the mask surface in each of the Nth scan and the N+1th scan, which is achieved by the operation of the laser annealing apparatus 12C according to the third modification of the second embodiment. Figure 31 In FIG. 1 , the graph indicated by the dotted line in the (N+1)th scan shows the energy density distribution before the tilt of the dichroic filter 94 is adjusted.

[0260] like Figure 31 As shown, the controller 70 tilts the dichroic filter 94 during the (N+1)th scan to adjust the transmittance characteristics of the illumination light. Specifically, by tilting the dichroic filter 94, the energy density ED(N+1) of the (N+1)th scan is adjusted so that the energy density ED(N+1, A) at the A end of the (N+1)th scan is substantially equal to the energy density ED(N, B) at the B end of the (N)th scan.

[0261] Furthermore, the controller 70 may also expand the angle adjustment range of the rotation mechanism 99 by driving the filter actuator 98 including the linear motion stage in the Z direction.

[0262] 4.6.3 Action / Effect

[0263] According to the laser annealing apparatus 12C of this modification, when the energy density at the end portion A is adjusted, the energy density difference between the irradiation regions around the end portion can be alleviated.

[0264] 4.6.4 Others

[0265] Figure 32 FIG. 1 is a top view showing another embodiment of the color separation filter 94 that can be applied to the laser annealing apparatus 12C. Figure 29 and Figure 30The color separation filter 94 described in Figure 32 As shown, the dichroic filter 94 may cover only a portion of the optical path. Alternatively, a dichroic film may be applied to a portion of the substrate that transmits the laser light.

[0266] By controlling the linear motion stage in each of the Y and Z directions, the same effects as those of the second embodiment can be obtained.

[0267] 4.7 Modification 4

[0268] 4.7.1 Structure

[0269] Figure 33 The structure of a laser annealing apparatus 12D according to a fourth modification of the second embodiment is schematically shown. Figure 33 The structure shown is Figure 29 The differences are explained. Figure 33 The laser annealing device 12D sets the pulse laser incident on the color separation filter 94 as divergent light or convergent light. Figure 29 The illumination optical system 30 in the embodiment has an illumination optical system 31 that emits divergent light or convergent light, and further, a collimating optical system 44 is provided downstream of the dichroic filter 94. Figure 33 , an example of an illumination optical system 31 that emits divergent light is shown.

[0270] The dichroic filter 94 has a characteristic in which the transmittance changes depending on the incident angle of the incident laser light. Therefore, when divergent light or convergent light is incident, the incident angles are different depending on the incident position, and the transmittance also changes.

[0271] The collimating optical system 44 is an optical system that converts incident divergent light or convergent light into parallel light. The collimating optical system 44 may be, for example, a collimating lens.

[0272] 4.7.2 Action

[0273] When the dichroic filter 94 is tilted by the rotating mechanism 99, the incident angle of the divergent light or the convergent light changes according to the incident position of the dichroic filter 94. Therefore, the energy density distribution in the Y direction of the pulsed laser light after passing through the dichroic filter 94 changes. Figure 34 As shown, the controller 70 controls the tilt of the color filter 94 to adjust the energy density at both ends so that the energy density at the B end of the Nth scan and the A end of the N+1th scan are approximately equal. Furthermore, the controller 70 can also drive the Z-direction linear motion stage of the filter actuator 98 to change the overall light intensity of the laser light passing through the color filter 94. Figure 34 In FIG. 1 , the graph indicated by the dotted line in the (N+1)th scan shows the energy density distribution before the tilt of the dichroic filter 94 is adjusted.

[0274] 4.7.3 Action / Effect

[0275] According to this modification 4, the degree of freedom in adjusting the energy density can be increased. For example, the energy density at the A end can be reduced while the energy density at the B end can be increased.

[0276] 5. Another method for measuring the energy density of pulsed laser

[0277] Figure 35 This is a diagram schematically showing the main structure of another example of a method for measuring the energy density of pulsed laser light. Figure 11 and Figure 13 The energy density measuring unit of the energy density measuring device 63 described in the above-mentioned examples may also be used. Figure 35 The structure shown. Figure 35 The structure shown is Figure 11 The differences between the laser annealing apparatus 11A and the laser annealing apparatus 11A will be described.

[0278] Figure 35 The energy density measurement unit shown includes a beam splitter 65 disposed in front of the mask 52, and an energy density meter 66 disposed so that the reflected light from the beam splitter 65 is incident. The beam splitter 65 is disposed on the optical path between the high-reflection mirror 40 and the mask 52. The energy density meter 66 is composed of a combination of an optical system (not shown) and a beam analyzer. The optical system is configured to form an image identical to the mask 52 based on the reflected light from the beam splitter 65.

[0279] A portion of the laser light traveling from the high reflective mirror 40 toward the mask 52 is reflected by the beam splitter 65 and the energy density distribution is measured by a beam profiler via an optical system configured to form an image identical to the mask 52. Furthermore, a gate (not shown) may be provided to protect the beam profiler.

[0280] Furthermore, a light distribution adjuster 95 such as a wire filter, a gradient filter, or a dichroic filter may be disposed on the optical path between the high reflective mirror 40 and the beam splitter 65 .

[0281] Figure 35 The structure shown can be used as Figure 5 The energy density meter 62 in the apparatus is used as a replacement unit. Figure 35 The structure shown can be used as Figure 18 、 Figure 21 、 Figure 25 、 Figure 27 、 Figure 29 and Figure 33 It is adopted as a replacement unit for the energy density meter 63 in.

[0282] 6. Configuration of Multiple Irradiation Areas within a Unified Irradiation Area

[0283] exist Figure 3 In the example of the unified irradiation region 84, a unified irradiation region 84 having an arrangement pattern for uniformly irradiating 3 × 7 annealing regions 82 on the substrate 80 is illustrated. However, in general, the unified irradiation region has an arrangement pattern for uniformly irradiating m1 × m2 processed regions. Here, m1 is an integer greater than 1, and m2 is an integer greater than m1. In other words, the unified irradiation region is composed of an arrangement of m1 × m2 irradiation regions, where each m1 × m2 irradiation region row is composed of m2 irradiation regions arranged in the Y direction and m1 rows are arranged in the X direction.

[0284] The controller 70 controls the energy density adjustment devices such as the reflector actuator 42 and the wire filter 90 so that the energy density of one irradiation area at a position corresponding to the A end among the m2 irradiation areas arranged along the Y direction in the N+1 scanning area is close to the energy density of one irradiation area at a position corresponding to the B end among the m2 irradiation areas arranged along the Y direction in the N scanning area.

[0285] 7. Method for manufacturing electronic devices

[0286] By using any one of the laser annealing devices 11, 11A, 11B, 12, 12A, 12B, 12C, and 12D described as the above-mentioned embodiments 1 and 2 and the modified examples of each embodiment, each annealing region 82 of the substrate 80 is annealed, thereby manufacturing an electronic device including a semiconductor element represented by a TFT.

[0287] 8. Others

[0288] The technical matters described in the above-mentioned embodiments and modifications may be appropriately combined within a possible range.

[0289] The above description is not limiting but merely illustrative. Therefore, those skilled in the art will appreciate that modifications can be made to the embodiments of the present disclosure without departing from the scope of the claims. Furthermore, those skilled in the art will appreciate that combinations of the embodiments of the present disclosure can be used.

[0290] Unless otherwise expressly stated, the terms used in this specification and claims as a whole should be interpreted as “non-limiting” terms. For example, terms such as “including” or “comprising” should be interpreted as “not limited to the parts recorded as included”. Terms such as “having” should be interpreted as “not limited to the parts recorded as having”. In addition, the indefinite article “a” should be interpreted as meaning “at least one” or “one or more”. In addition, terms such as “at least one of A, B and C” should be interpreted as “A”, “B”, “C”, “A+B”, “A+C”, “B+C” or “A+B+C”. Furthermore, it should be interpreted as also including combinations of these and parts other than “A”, “B” and “C”.

Claims

1. A laser annealing device comprising: a laser device that outputs laser light; an optical system for uniformly irradiating a plurality of processing areas arranged along at least a second direction of a first direction in a plane of a processing object and a second direction perpendicular to the first direction with the laser beam; a relative movement device for relatively moving a uniform irradiation area and the workpiece in the first direction and the second direction, the uniform irradiation area having an arrangement of a plurality of irradiation areas of the laser corresponding to the arrangement of the plurality of workpiece areas subjected to the uniform irradiation; as well as a controller that controls the laser device and the relative movement device so that N is set to an integer greater than 1, and during an N-th scan, performs a scan in which the unified irradiation area and the workpiece are relatively moved in the first direction in an N-th scanning area of ​​the workpiece, irradiates the workpiece areas arranged in a grid along the first direction and the second direction in the N-th scanning area with the laser, and after the N-th scan, relatively moves the unified irradiation area and the workpiece in the second direction, changes the scan target area to an N+1-th scanning area, and during the N+1-th scan, performs the scan in the N+1-th scanning area that is adjacent to the N-th scanning area of ​​the workpiece and does not overlap with the N-th scanning area. Wherein, the laser annealing device further comprises: an energy density measuring device for measuring the energy density of the pulsed laser light irradiated on at least the second end portion of the first end portion and the second end portion of the uniform irradiation region in the second direction; as well as an energy density adjusting device for adjusting the energy density of the pulse laser light irradiated on at least the first end portion of the first end portion and the second end portion of the uniform irradiation region; The controller controls the energy density adjustment device according to the measurement results of the energy density measuring device, and adjusts the energy density of the first end when performing the N+1 scan, so that the energy density of the pulsed laser irradiated at the first end in the N+1 scanning area adjacent to the second end in the N scanning area is close to the energy density of the pulsed laser irradiated at the second end in the N scanning area.

2. The laser annealing device according to claim 1, wherein: The controller changes the adjustment amount of the energy density adjustment device before starting to process the workpiece, and measures the energy density of the pulsed laser irradiated on each of the first end and the second end by the energy density measuring device, thereby obtaining relationship information indicating the relationship between the adjustment amount of the energy density adjustment device and the energy density of the pulsed laser irradiated on each of the first end and the second end. In processing the workpiece, the energy density adjusting device is controlled based on the relationship information to adjust the energy density of the pulsed laser light irradiated on the first end portion during the (N+1)th scan.

3. The laser annealing apparatus according to claim 1, wherein: During the execution of the N-th scan, the energy density is measured by the energy density measurement device. The controller adjusts the energy density of the pulsed laser light irradiated to the first end portion during the (N+1)th scan based on a measurement result of the energy density of the pulsed laser light irradiated to the second end portion measured during the execution of the (N)th scan.

4. The laser annealing apparatus according to claim 1, wherein: When m1 is an integer greater than 1 and m2 is an integer greater than m1, The unified irradiation area has an arrangement of m1×m2 irradiation areas, wherein the m1×m2 irradiation areas are arranged in a row of m2 irradiation areas arranged along the second direction and m1 rows arranged in the first direction. The controller controls the energy density adjustment device so that the energy density of the pulsed laser irradiated at one of the m2 irradiation areas arranged along the second direction in the N+1 scanning area and corresponding to the first end is close to the energy density of the pulsed laser irradiated at one of the m2 irradiation areas arranged along the second direction in the N scanning area and corresponding to the second end.

5. The laser annealing apparatus according to claim 1, wherein: The optical system has: a mask having a mask pattern forming the plurality of irradiation areas; and A reflecting mirror reflects the laser light toward the mask.

6. The laser annealing apparatus according to claim 5, wherein: The energy density adjustment device includes a rotation mechanism for adjusting the reflection angle of the reflector.

7. The laser annealing apparatus according to claim 5, wherein: The energy density adjustment device includes a mirror moving mechanism that adjusts the position of the mirror in the second direction.

8. The laser annealing apparatus according to claim 5, wherein: The energy density adjustment device comprises: a filter that shields a portion of the laser light incident on the mask; and An actuator adjusts at least one of a position and an angle of the optical filter.

9. The laser annealing apparatus according to claim 8, wherein: The optical filter is a wire filter formed using one or more electric wires.

10. The laser annealing apparatus according to claim 8, wherein: The optical filter is configured such that a part of a transparent substrate is coated with a material that does not transmit the laser light.

11. The laser annealing apparatus according to claim 10, wherein: The optical filter is a graded filter coated with the material that does not transmit the laser light or the material that partially transmits the laser light to form a continuous transmittance distribution.

12. The laser annealing apparatus according to claim 8, wherein: The optical filter is a graded filter made of a material having a predetermined transmittance per unit length with respect to the wavelength of the laser light, and the thickness of the filter changes continuously depending on the location of the filter.

13. The laser annealing apparatus according to claim 8, wherein: The optical filter is composed of a substrate coated with a dichroic film whose transmittance changes according to the incident angle of the laser light. The actuator adjusts the angle of the filter and adjusts the incident angle of the laser light relative to the filter.

14. The laser annealing apparatus according to claim 5, wherein: The energy density measuring device measures the energy density at a position of the mask.

15. The laser annealing apparatus according to claim 1, wherein: The energy density measuring device measures the energy density at a position of the workpiece.

16. The laser annealing apparatus according to claim 1, wherein: The energy density measurement device includes a first end portion measurement device for measuring the energy density of the pulse laser beam irradiated at the first end portion and a second end portion measurement device for measuring the energy density of the pulse laser beam irradiated at the second end portion.

17. The laser annealing apparatus according to claim 1, wherein: The energy density measurement device includes a beam profiler that measures energy density distribution of the unified irradiation including the first end portion and the second end portion.

18. The laser annealing apparatus according to claim 17, wherein: The optical system has: a mask for forming the plurality of irradiation areas corresponding to the arrangement of the plurality of processed areas; a reflector that reflects the laser light toward the mask; as well as a beam splitter arranged on an optical path between the reflector and the mask, A portion of the laser light enters the energy density measurement device via the beam splitter.

19. A method for manufacturing an electronic device, comprising: Using a laser annealing device, a plurality of scans including an Nth scan and an N+1th scan are performed on a workpiece, and the processed areas of the workpiece are annealed respectively to manufacture an electronic device. The laser annealing device comprises: a laser device that outputs laser light; an optical system for uniformly irradiating the plurality of processed regions arranged along at least a second direction of a first direction within a plane of the workpiece and a second direction perpendicular to the first direction with the laser beam; a relative movement device for relatively moving a uniform irradiation area and the workpiece in the first direction and the second direction, the uniform irradiation area having an arrangement of a plurality of irradiation areas of the laser corresponding to the arrangement of the plurality of workpiece areas subjected to the uniform irradiation; as well as a controller that controls the laser device and the relative movement device so that N is set to an integer greater than 1, and during the N-th scan, performs the scan in which the unified irradiation area and the workpiece are relatively moved in the first direction in the N-th scanning area of ​​the workpiece, irradiates the workpiece areas arranged in a grid along the first direction and the second direction in the N-th scanning area with the laser, and after the N-th scan, relatively moves the unified irradiation area and the workpiece in the second direction, changes the scan target area to the N+1-th scanning area, and during the N+1-th scan, performs the scan in the N+1-th scanning area that is adjacent to the N-th scanning area of ​​the workpiece and does not overlap with the N-th scanning area, The laser annealing device further comprises: an energy density measuring device for measuring the energy density of the pulsed laser light irradiated on at least the second end portion of the first end portion and the second end portion of the uniform irradiation region in the second direction; as well as an energy density adjusting device for adjusting the energy density of the pulse laser light irradiated on at least the first end portion of the first end portion and the second end portion of the uniform irradiation region; The controller controls the energy density adjustment device according to the measurement results of the energy density measuring device, and adjusts the energy density of the first end when performing the N+1 scan, so that the energy density of the pulsed laser irradiated at the first end in the N+1 scanning area adjacent to the second end in the N scanning area is close to the energy density of the pulsed laser irradiated at the second end in the N scanning area.

20. The method for manufacturing an electronic device according to claim 19, wherein: The workpiece is a substrate coated with amorphous silicon, The laser is a pulsed laser with an ultraviolet wavelength.

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