Laser annealing system

Abstract

The laser annealing system includes: a laser system; and a laser annealing device, which irradiates a first pulse laser and a second pulse laser to an irradiated object, the laser annealing device includes: an irradiation optical system, which guides the first pulse laser and the second pulse laser to the irradiated object; a moving mechanism, which causes the irradiation positions of the first pulse laser and the second pulse laser to move relative to the irradiation position of the irradiated object; and a control unit, which controls the laser system so that the irradiated object is irradiated with the first pulse laser, and after the irradiation with the first pulse laser, the area of ​​the irradiated object irradiated with the first pulse laser is irradiated with the second pulse laser, the laser system includes: a laser oscillator, which outputs a pulse laser; an optical pulse stretcher, which stretches the pulse laser output from the laser oscillator; and a gate, which is arranged on a delay optical path of the optical pulse stretcher, and the control unit controls the output of the first pulse laser and the second pulse laser by controlling the opening and closing of the gate.

Description

Technical Field

[0001] The present disclosure relates to laser annealing systems. Background Art

[0002] Thin film transistors (TFTs) are used as driving elements for flat panel displays using glass substrates. In order to realize high-definition displays, it is necessary to produce TFTs with high driving force. Polycrystalline silicon, IGZO (Indium gallium zinc oxide), etc. are used as the channel material of TFT, i.e., semiconductor thin film. Compared with amorphous silicon, polycrystalline silicon and IGZO have high carrier mobility and excellent on / off characteristics of transistors.

[0003] In addition, semiconductor thin films are expected to be applied to 3D-ICs that realize devices with higher functions. 3D-ICs are realized by forming active elements such as sensors, amplifier circuits, and CMOS circuits on the top layer of integrated circuit devices. Therefore, technology for manufacturing semiconductor thin films with higher quality is required.

[0004] Furthermore, as information terminal devices become more diverse, demands for flexible displays and computers that are small, lightweight, consume less power, and can be bent freely are increasing. Therefore, it is required to establish a technology for forming high-quality semiconductor thin films on plastic substrates such as PET (Polyethyleneterephthalate).

[0005] In order to form a high-quality semiconductor thin film on a glass substrate, an integrated circuit, or a plastic substrate, it is necessary to crystallize the semiconductor thin film in a manner that does not cause thermal damage to these substrates. The process temperature is required to be below 400°C for glass substrates used in displays, below 400°C for integrated circuits, and below 200°C for PET as a plastic substrate.

[0006] Laser annealing is a technique for crystallizing a semiconductor thin film without causing thermal damage to the underlying substrate. In this method, pulsed ultraviolet laser light absorbed by the upper semiconductor thin film is used 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, a KrF excimer laser with a wavelength of 248 nm, etc. are used. Compared with solid lasers, these gas lasers in the ultraviolet region have the following characteristics: the interference of the laser is low, the energy uniformity in the laser irradiation surface is excellent, and a wide area can be annealed uniformly with high pulse energy.

[0008] Prior art literature

[0009] Patent Literature

[0010] Patent Document 1: U.S. Patent Application Publication No. 2005 / 0211987

[0011] Patent Document 2: Japanese Patent Application Publication No. 2007-287866

[0012] Patent Document 3: U.S. Patent No. 6117752

[0013] Patent Document 4: U.S. Patent Application Publication No. 2018 / 0040718

[0014] Patent Document 5: International Publication No. 2018 / 047220 Summary of the invention

[0015] A method for manufacturing a semiconductor crystal film according to one aspect of the present disclosure includes the following steps: polycrystallizing an amorphous semiconductor by irradiating the amorphous semiconductor with a first pulse laser having a first pulse time width; and reducing the height of a ridge of the semiconductor crystal by irradiating a region of the semiconductor crystal polycrystallized by irradiating the first pulse laser with a second pulse time width shorter than the first pulse time width.

[0016] A laser annealing system according to another aspect of the present disclosure includes: a laser system that outputs a first pulse laser with a first pulse time width and a second pulse laser with a second pulse time width shorter than the first pulse time width; and a laser annealing device that irradiates an object with the first pulse laser and the second pulse laser, the laser annealing device including: an irradiation optical system that guides the first pulse laser and the second pulse laser to the object; a moving mechanism that relatively moves the irradiation positions of the first pulse laser and the second pulse laser with respect to the object; and a control unit that controls the laser system so that the object is irradiated with the first pulse laser, and after the first pulse laser is irradiated, the second pulse laser is irradiated to a region of the object irradiated with the first pulse laser. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Hereinafter, several embodiments of the present disclosure will be described as simple examples with reference to the accompanying drawings.

[0018] Figure 1 This is a diagram for explaining the pulse time width of laser light.

[0019] Figure 2 The structure of an exemplary laser annealing system is schematically shown.

[0020] Figure 3 It is a plan view showing an example of the relationship between the pattern of the mask and the line beam that illuminates the mask.

[0021] Figure 4 It is a top view showing an example of scanning irradiation of an object with a line beam.

[0022] Figure 5 Is Figure 4 An enlarged view of the portion enclosed by the dotted circle.

[0023] Figure 6 This is a flowchart showing an example of the operation in the laser annealing system.

[0024] Figure 7 It is shown that it is applied to Figure 6 This is a flowchart of an example of a subroutine of step S12.

[0025] Figure 8 It is shown that it is applied to Figure 6 This is a flowchart of an example of a subroutine of step S14.

[0026] Fig. 9 is shown to be applied to Figure 6 A flowchart of an example of a subroutine of step S20 is shown in FIG.

[0027] Fig.10 is shown to be applied to Figure 6 This is a flowchart of an example of a subroutine of step S22.

[0028] Fig.11 Schematic diagram of the fabrication process of semiconductor crystal thin films based on laser annealing.

[0029] Fig.12 1 is a schematic diagram illustrating a process of manufacturing a semiconductor crystal thin film according to Embodiment 1.

[0030] Fig.13 This is a graph showing the laser irradiation conditions used in the test.

[0031] Fig.14 It is a graph showing an example of a pulse waveform of a laser beam.

[0032] Fig.15 A configuration example of an optical pulse stretcher system is shown.

[0033] Fig.16 Examples of mask patterns and crystal growth are shown.

[0034] Fig.17 The configuration of the laser annealing system according to the first embodiment is schematically shown.

[0035] Fig.18 This is a plan view showing an example of beam scanning irradiation during ridge flattening in the first embodiment.

[0036] Fig.19 This is a flowchart showing an example of the operation in the laser annealing system according to the first embodiment.

[0037] Fig. 20 is shown to be applied to Fig.19 This is a flowchart of an example of a subroutine of step S13.

[0038] Fig.21 is shown to be applied to Fig.19 This is a flowchart of an example of a subroutine of step S21.

[0039] Fig. 22 is shown to be applied to Fig.19 This is a flowchart of an example of a subroutine of step S24.

[0040] Fig.23 is shown to be applied to Fig.19 This is a flowchart of an example of a subroutine of step S26.

[0041] Fig.24 is shown to be applied to Fig.19 This is a flowchart of an example of a subroutine of step S28.

[0042] Fig.25 The structure of the laser annealing system according to the second embodiment is schematically shown.

[0043] Fig.26 The structure of the laser annealing system according to the third embodiment is schematically shown.

[0044] Fig. 27 It is a plan view showing an example of the relationship between the pattern of the mask and the line beam that illuminates the mask.

[0045] Fig.28 It is a top view showing an example of scanning irradiation of an object with a line beam.

[0046] Fig.29 The structure of the laser annealing system according to the fourth embodiment is schematically shown.

[0047] Fig.30 The structure of the laser annealing system according to the fifth embodiment is schematically shown.

[0048] Fig.31 The structure of the laser annealing system according to the sixth embodiment is schematically shown.

[0049] Fig.32 An example of a mask and an irradiation area of ​​the mask with a beam is shown.

[0050] Fig.33 This is an enlarged view showing an example of a fine pattern formed in the pattern region of the mask.

[0051] Fig.34 It is an explanatory diagram of the operation of the laser annealing system according to the sixth embodiment.

[0052] Fig.35 The structure of the laser annealing system according to the seventh embodiment is schematically shown.

[0053] Fig.36 The structure of the laser annealing system according to the eighth embodiment is schematically shown. DETAILED DESCRIPTION

[0054] -Table of contents-

[0055] 1. Explanation of terms

[0056] 2. Overall description of laser annealing system

[0057] 2.1 Structure

[0058] 2.2 Action

[0059] 2.3 Action Examples

[0060] 2.4 Others

[0061] 3.Topics

[0062] 4. Implementation Method 1

[0063] 4.1 Overview of the method for manufacturing semiconductor crystal thin films

[0064] 4.2 Examples related to irradiation conditions

[0065] 4.3 Mask Patterning and Crystal Growth Examples

[0066] 4.4 Structure of laser annealing system

[0067] 4.5 Action

[0068] 4.6 Action Examples

[0069] 4.7 Effects

[0070] 4.8 Variations

[0071] 5. Implementation Method 2

[0072] 5.1 Structure

[0073] 5.2 Action

[0074] 5.3 Effects

[0075] 6. Implementation Method 3

[0076] 6.1 Structure

[0077] 6.2 Action

[0078] 6.3 Effects

[0079] 7. Implementation Method 4

[0080] 7.1 Structure

[0081] 7.2 Action

[0082] 7.3 Effects

[0083] 7.4 Variations

[0084] 8. Implementation Method 5

[0085] 8.1 Structure

[0086] 8.2 Action

[0087] 8.3 Action / Effect

[0088] 8.4 Variations

[0089] 9. Implementation Method 6

[0090] 9.1 Structure

[0091] 9.2 Action

[0092] 9.3 Effects

[0093] 9.4 Variations

[0094] 10. Implementation Method 7

[0095] 10.1 Structure

[0096] 10.2 Actions

[0097] 10.3 Effects

[0098] 10.4 Variations

[0099] 11. Implementation Method 8

[0100] 11.1 Structure

[0101] 11.2 Actions

[0102] 11.3 Effects

[0103] 11.4 Variations

[0104] 12. Others

[0105] Below, the embodiments of the present disclosure are described in detail with reference to the accompanying drawings. The embodiments described below show 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 necessary for the structures and actions of the present disclosure. In addition, the same reference numerals are marked on the same structural elements and repeated descriptions are omitted.

[0106] 1. Explanation of terms

[0107] Figure 1 This is a diagram for explaining the pulse time width of laser light. Figure 1 The vertical axis is the light intensity I [au], and the horizontal axis is the time t [ns]. The light intensity I [au] is a value normalized by setting the peak value (maximum light intensity value) of the light intensity waveform to 1. As an indicator of the pulse time width of the laser, the pulse time width ΔT can be used. 50％ .like Figure 1 As shown, the pulse time width ΔT 50％ It refers to the full width of the time when the light intensity is 50% of the maximum value.

[0108] In addition, as another indicator of the laser pulse time width, the TIS pulse time width ΔT can be used. TIS .

[0109] TIS pulse time width ΔT TIS It is defined by the following formula (1).

[0110] [Formula 1]

[0111]

[0112] Here, t is time. I(t) is the light intensity at time t.

[0113] 2. Overall description of laser annealing system

[0114] 2.1 Structure

[0115] Figure 2 The structure of the laser annealing system is schematically shown. The laser annealing system 10 includes a laser device 20, an optical path pipe 25, and a laser annealing device 100. The optical path pipe 25 is arranged on the optical path of the laser light between the laser light output port of the laser device 20 and the laser light input port of the laser annealing device 100.

[0116] The laser device 20 is a laser device that outputs ultraviolet pulsed laser. For example, the laser device 20 may be a laser device that outputs ultraviolet pulsed laser. 2The laser device 20 includes a master oscillator (MO) 30, an optical pulse stretcher (OPS) system 32, a monitor module 34, a gate 36, and a laser control unit 38.

[0117] The master oscillator 30 includes a cavity 40 , an optical resonator 42 , a charger 44 , and a pulse power module (PPM) 46 .

[0118] An excimer laser gas containing a laser medium is sealed in the cavity 40. The excimer laser gas may contain a rare gas such as Ar, Kr, or Xe, F 2 or Cl 2 A mixed gas of halogen gas such as argon and buffer gas such as He or Ne.

[0119] The cavity 40 includes a pair of electrodes 48a and 48b and windows 50 and 52. The pair of electrodes 48a and 48b are arranged in the cavity 40. The electrode 48a is supported by an insulating member 54. The electrode 48a is connected to the PPM 46 via a conductive portion 56 embedded in a feedthrough hole of the insulating member 54. The electrode 48b is supported by a return plate (not shown), and the return plate is connected to the inner surface of the cavity 40 using a wiring (not shown).

[0120] The PPM 46 includes a switch 47, a boost transformer and a magnetic compression circuit, both of which are not shown. The PPM 46 is connected to a charger 44. The charger 44 is a DC power supply device that charges a charging capacitor (not shown) in the PPM 46 at a predetermined voltage.

[0121] The optical resonator 42 includes a rear mirror 60 and an output coupling mirror 62. The rear mirror 60 is a planar substrate coated with a high reflection film. The output coupling mirror 62 is a planar substrate coated with a partial reflection film. The cavity 40 is arranged on the optical path of the optical resonator 42.

[0122] The OPS system 32 is disposed on an optical path between the master oscillator 30 and the monitor module 34. The OPS system 32 includes an optical pulse stretcher (OPS) 33 that delays a portion of incident light and stretches the temporal width of pulsed laser light.

[0123] The OPS 33 includes a beam splitter 70 and concave mirrors 71 to 74. The beam splitter 70 is disposed on an optical path between the master oscillator 30 and the monitor module 34. The beam splitter 70 is coated with a film that partially reflects a portion of the incident pulse laser light.

[0124] The concave mirrors 71 to 74 are arranged such that their respective focal lengths are the same, and the beam of pulsed laser reflected from the beam splitter 70 is highly reflected by the four concave mirrors 71 to 74, and the beam is transferred at the position where it re-enters the beam splitter 70.

[0125] The monitor module 34 includes a beam splitter 76 and a light sensor 77.

[0126] The shutter 36 is arranged on the optical path of the pulsed laser output from the monitor module 34.

[0127] The optical path of the pulsed laser can also be sealed by a housing and an optical path tube 25 (not shown) and purged with N 2 gas or the like.

[0128] The laser annealing apparatus 100 includes an irradiation optical system 110, a frame 170, an XYZ stage 172, a stage 174, and a laser annealing control unit 180. An object 190 to be irradiated is fixed on the stage 174.

[0129] The irradiation optical system 110 includes high reflection mirrors 121 to 123, an attenuator 130, an illumination optical system 140, a mask 148, a projection optical system 150, a window 160, and a housing 164.

[0130] The high reflection mirror 121 is arranged such that the laser passing through the optical path tube 25 enters the high reflection mirror 122 through the attenuator 130.

[0131] The attenuator 130 is arranged on the optical path between the high reflection mirror 121 and the high reflection mirror 122. The attenuator 130 includes two partial reflection mirrors 131 and 132, and rotating stages 135 and 136 that can vary the incident angles of the respective partial reflection mirrors 131 and 132.

[0132] The high reflection mirror 122 is arranged such that the laser passing through the attenuator 130 enters the high reflection mirror 123. The high reflection mirror 123 is arranged such that the incident pulsed laser enters the fly-eye lens 145 of the illumination optical system 140.

[0133] The illumination optical system 140 includes a fly-eye lens 145 and a condenser lens 146. The illumination optical system 140 is an optical system for uniformly illuminating a specified illumination area on the mask 148, and is arranged to perform Kohler illumination on the mask 148 using a rectangular beam. Let the beam width in the X-axis direction of the rectangular beam irradiated on the mask 148 be Bmx, and the beam width in the Y-axis direction be Bmy. Here, a rectangle satisfying Bmx < Bmy, that is, a rectangle with the Y-axis direction as the major axis direction, is used. In this specification, the rectangular beam is referred to as a "line beam".

[0134] For example, the fly-eye lens 145 is arranged so that the focal plane of the fly-eye lens 145 coincides with the front focal plane of the condenser lens 146 , and the condenser lens 146 is arranged so that the rear focal plane of the condenser lens 146 coincides with the position of the mask 148 .

[0135] The mask 148 is, for example, a mask on which a metal or dielectric multilayer film pattern is formed on a synthetic quartz substrate that transmits ultraviolet light. The mask 148 is formed with, for example, a line and space pattern (see Figure 3 ).

[0136] The projection optical system 150 is arranged so that an image of the mask 148 is formed on the surface of the irradiated object 190 through the window 160. The projection optical system 150 may be a combination of a plurality of lenses 152, or may be a reduction projection optical system.

[0137] The window 160 is disposed on the optical path between the projection optical system 150 and the irradiated object 190. The window 160 is disposed in a hole provided in the housing 164 via an O-ring or the like (not shown). The window 160 may be a CaF 2 The crystal or synthetic quartz substrate may be coated with a reflection-reducing film on both surfaces.

[0138] Nitrogen (N 2 ) gas inlet 166 and outlet 168. The housing 164 may be sealed by an O-ring (not shown) or the like to prevent external gas from entering the housing 164. 2 The gas inlet 166 is connected to the N 2 Gas supply connection.

[0139] The irradiation optical system 110 and the XYZ axis stage 172 are fixed to the frame 170. The XYZ axis stage 172 is an electric stage for relatively moving the irradiation position of the pulse laser with respect to the irradiation object 190. The stage 174 is fixed to the XYZ axis stage 172. The irradiation object 190 is fixed to the stage 174.

[0140] The irradiated object 190 is, for example, a glass substrate on which amorphous silicon is coated. Here, a silicon thin film is used as an example for explanation, but the semiconductor thin film may be at least one of Si, Ge, SiGe, and GeSn.

[0141] Figure 3It is a top view showing an example of the relationship between the pattern of mask 148 and the line beam LBm that illuminates mask 148. The pattern of mask 148 is, for example, a line-and-space pattern in which line portions 148L as light-shielding portions and space portions 148S as light-passing portions (non-light-shielding portions) are alternately arranged. The short-axis direction (X-axis direction) of the line beam LBm that uniformly illuminates mask 148 is parallel to the line direction of line portions 148L, and multiple line portions 148L are arranged at a prescribed interval in the long-axis direction (Y-axis direction) of line beam LBm.

[0142] The laser irradiated onto the irradiated object 190 via mask 148 is a beam group including a pattern corresponding to the image of the pattern of mask 148. Regarding the pattern of the laser irradiated onto the irradiated object 190 via mask 148, the overall shape based on the light-shielding portion of mask 148 is substantially rectangular, and thus, the laser irradiated onto the irradiated object 190 is also referred to as a "line beam".

[0143] When the beam width of the line beam in the X-axis direction on the irradiated object 190 is set to Bx and the beam width in the Y-axis direction is set to By, here it is a line beam that satisfies Bx < By (refer to Figure 4 ).

[0144] 2.2 Operations

[0145] The laser annealing control unit 180 reads the irradiation condition parameters during laser annealing. Specifically, it reads each data of the fluence Fa, the number of irradiation pulses Na, and the repetition frequency fa on the irradiated object 190 during laser annealing.

[0146] Various data and signals such as the target pulse energy Et are transmitted and received between the laser annealing control unit 180 and the laser control unit 38. The laser annealing control unit 180 causes the laser device 20 to perform adjustment oscillation. The laser control unit 38 receives the data of the target pulse energy Et from the laser annealing control unit 180.

[0147] When the laser control unit 38 receives the data of the target pulse energy Et, it closes the shutter 36 and controls the charger 44 to achieve the target pulse energy Et.

[0148] The laser control unit 38 generates an internal trigger signal through an internal trigger generation unit (not shown) and inputs the internal trigger signal to the switch 47 of the PPM 46. As a result, the master oscillator 30 performs natural oscillation.

[0149] Regarding the pulsed laser output from the master oscillator 30, the time width of the pulsed laser is broadened by the OPS system 32. The pulsed laser emitted from the OPS system 32 is sampled by the beam splitter 76 of the monitor module 34, and the pulse energy E is measured.

[0150] The laser control unit 38 controls the charging voltage of the charger 44 so that the difference ΔE between the pulse energy E and the target pulse energy Et approaches zero.

[0151] When ΔE falls within the permissible range, the laser control unit 38 sends an external trigger OK signal to the laser annealing control unit 180 to open the gate 36 .

[0152] The laser annealing control section 180 receives an external trigger OK signal from the laser control section 38 .

[0153] Then, the laser annealing control unit 180 controls the X-axis and the Y-axis of the XYZ-axis stage 172 so that the position where the image of the mask 148 is transferred by the projection optical system 150 becomes the initial position.

[0154] Next, the laser annealing control unit 180 controls the Z axis of the XYZ axis stage 172 so that the image of the mask 148 is formed at a position on the surface of the irradiated object 190 .

[0155] The laser annealing control unit 180 calculates the transmittance T of the attenuator 130 so that the fluence at the surface position of the irradiated object 190 (that is, the position of the image of the mask 148 ) becomes the target fluence Fa.

[0156] Next, the laser annealing control unit 180 controls the incident angles of the two partial reflection mirrors 131 and 132 via the respective rotating stages 135 and 136 so that the transmittance of the attenuator 130 becomes T.

[0157] Next, the laser annealing control unit 180 calculates the moving speed Vx of the XYZ-axis stage 172 so that the number of irradiation pulses when the repetition frequency is fa and the line beam width Bx on the irradiated object 190 becomes Na.

[0158] The laser annealing control unit 180 controls the XYZ stage 172 to move the stage 174 in a uniform linear motion at a speed Vx in the X-axis direction. As a result, the line beam moves uniformly at a speed Vx on the surface of the irradiated object 190 in a direction opposite to the moving direction of the stage 174.

[0159] During this period, the laser annealing control unit 180 sends a light emission trigger signal Tr of a repetition frequency fa to the laser control unit 38. As a result, pulsed laser light is outputted from the master oscillator 30 in synchronization with the light emission trigger signal Tr, and the pulsed laser light transmitted through the beam splitter 76 of the monitor module 34 enters the laser annealing device 100 via the optical path tube 25.

[0160] The pulse laser incident on the laser annealing apparatus 100 is reflected by the high reflection mirror 121 , attenuated by the attenuator 130 , and reflected by the high reflection mirror 122 .

[0161] The pulse laser light highly reflected by the high reflection mirrors 122 and 123 is spatially uniformized in light intensity by the illumination optical system 140 and is incident on the mask 148 as a line beam LBm.

[0162] The pulsed laser light transmitted through the mask 148 is projected onto the surface of the irradiated object 190 through the projection optical system 150. Thus, the pulsed laser light is irradiated onto the irradiated object 190 in the area where the image is transferred through the projection optical system 150. As a result, the portion of the surface of the irradiated object 190 irradiated with the pulsed laser light is laser annealed.

[0163] Figure 4 It is a top view showing an example of scanning irradiation of an object with a line beam. Figure 5 Is Figure 4 An enlarged view of the portion enclosed by the dotted circle.

[0164] The line beam LBa irradiated onto the surface of the irradiated object 190 is Figure 3 The line and space image pattern of the mask 148 illustrated in FIG. Figure 4 As shown in FIG. 1 , the beam width of the line beam LBa irradiated to the surface of the irradiated object 190 in the X-axis direction is Bx, and the beam width in the Y-axis direction is By. By moving the XYZ-axis stage 172, the line beam LBa moves relative to the irradiated object 190. By moving the XYZ-axis stage 172 in the positive direction of the X-axis, the line beam LBa moves in the negative direction of the X-axis ( Figure 4 left direction) in the middle.

[0165] exist Figure 4 , a scanning irradiation state of irradiating the surface of the irradiated object 190 with laser light is shown by moving the line beam LBa from the scanning irradiation initial position Spaini to the scanning irradiation end position Spaend relative to the irradiated object 190. The moving direction of the line beam LBa from the scanning irradiation initial position Spaini toward the scanning irradiation end position Spaend is referred to as the "scanning irradiation direction" during laser annealing.

[0166] exist Figure 4 In the embodiment, the area on the surface of the irradiated object 190 through which the line beam LBa passes, that is, the area subjected to scanning irradiation, becomes a crystallized area 190p where the amorphous silicon melts and the silicon is polycrystallized by crystal growth. The crystallized area 190p becomes a polycrystalline silicon film. The area on the surface of the irradiated object 190 through which the line beam LBa does not pass, that is, the area not subjected to scanning irradiation, is an amorphous area 190a which has not been irradiated with laser light and is still in an amorphous (non-crystalline) state.

[0167] exist Figure 5 Shown in Figure 4The enlarged view of the portion surrounded by the dotted circle in FIG. The line portion MLI of the imaging pattern of the mask 148 irradiated with the line beam LBa to the irradiated object 190 has a lower injection amount than the spacer portion MSI. Therefore, the morphology of the crystal after laser annealing is as follows: Figure 5 As shown, crystal nuclei are generated at positions corresponding to the line portions MLI on the surface of the irradiated object 190 , and large grain boundaries 192 are generated substantially in the center of the space portions MSI between the line portions MLI in the Y-axis direction.

[0168] The line beam LBa performs scanning irradiation while moving in the negative direction of the X axis, and the position of the line beam LBa relative to the irradiated object 190 reaches the scanning irradiation end position SpAend (see Figure 4 ) after which the movement of the XYZ axis stage 172 is stopped.

[0169] 2.3 Action Examples

[0170] Figure 6 : is a flowchart showing an example of the operation in the laser annealing system 10 . Figure 6 The processing and operation shown in the flowchart are realized by, for example, a processor functioning as the laser annealing control unit 180 executing a program.

[0171] In step S10, the irradiated object 190 is placed on the stage 174 of the XYZ-axis stage 172. The irradiated object 190 may be placed on the stage 174 by a workpiece conveying robot (not shown) or other automatic conveying devices.

[0172] In step S12, the laser annealing control unit 180 reads laser irradiation condition parameters during laser annealing (1). The laser irradiation condition parameters during laser annealing are referred to as "parameters of laser annealing conditions."

[0173] In step S14, the laser annealing control unit 180 controls the laser device 20 to perform regulated oscillation. The laser annealing control unit 180 controls the laser device 20 to perform regulated oscillation at a repetition frequency fa so as to achieve a target pulse energy Et.

[0174] In step S16 , the laser annealing control unit 180 controls the XYZ-axis stage 172 in the X-axis direction and the Y-axis direction so that the position of the line beam LBa on the irradiated object 190 becomes the initial position.

[0175] In step S18 , the laser annealing control unit 180 controls the XYZ-axis stage 172 in the Z-axis direction so that the image of the mask 148 is formed on the surface of the irradiated object 190 .

[0176] In step S20, the laser annealing control unit 180 calculates and sets the control parameters for laser annealing (1). Specifically, the laser annealing control unit 180 calculates and sets the transmittance Ta of the attenuator 130 so that the beam width Bx in the short axis direction is the fluence Fa. In addition, the laser annealing control unit 180 calculates the moving speed Vx of the XYZ axis stage 172 and sets the moving speed Vx so that the number of irradiation pulses Na is obtained in the case of the beam width Bx in the short axis direction.

[0177] In step S22, the laser annealing control unit 180 performs beam scanning irradiation during laser annealing according to the control parameter setting in step S20. During the beam scanning irradiation, the object 190 is irradiated with pulsed laser light under the conditions of the set repetition frequency fa, fluence Fa, and irradiation pulse number Na.

[0178] After step S22, the laser annealing control unit 180 ends Figure 6 Flowchart of the process.

[0179] Figure 7 is shown to be applied to Figure 6 Flowchart of an example of a subroutine of step S12. That is, Figure 7 An example of the processing contents performed in the step (1) of reading the laser irradiation condition parameters during laser annealing is shown.

[0180] exist Figure 7 In step S31, the laser annealing control unit 180 reads the parameters of the laser annealing conditions. For example, the laser annealing control unit 180 reads the data of the fluence Fa, the number of irradiation pulses Na, and the repetition frequency fa on the irradiated object 190 during the laser annealing process. Here, the number of irradiation pulses Na is set to an integer greater than 2. After step S31, the laser annealing control unit 180 returns to Figure 6 Flowchart of the process.

[0181] Figure 8 is shown to be applied to Figure 6 This is a flowchart of an example of a subroutine of step S14. That is, Figure 8 An example of the processing content performed in the step of adjusting the oscillation of the laser device is shown.

[0182] exist Figure 8In step S40, the laser annealing control unit 180 sends the data of the target pulse energy Et and the repetition frequency fa to the laser control unit 38. Preferably, the target pulse energy Et and the repetition frequency fa in this case are rated data at which the laser device 20 can operate stably. For example, the target pulse energy Et can be a value in the range of 30mJ to 1000mJ. In addition, the repetition frequency fa can be a value in the range of 600Hz to 6000Hz. In addition, the laser annealing control unit 180 can also pre-store the rated pulse energy of the laser device 20 as the target pulse energy Et and use this value.

[0183] In step S42, the laser annealing control unit 180 determines whether a pulse energy OK signal is received from the laser control unit 38. The determination process in step S42 corresponds to, for example, determining whether the difference between the pulse energy E of the pulse laser output from the laser device 20 and the target pulse energy Et is within the allowable range.

[0184] The laser annealing control unit 180 repeatedly performs step S42 until the determination result of step S42 becomes a "yes" determination. If the determination result of step S42 becomes a "yes" determination, the laser annealing control unit 180 exits the Figure 8 The subroutine returns Figure 6 Flowchart of the process.

[0185] Fig. 9 is shown to be applied to Figure 6 Flowchart of an example of a subroutine of step S20. That is, Fig. 9 An example of the processing contents performed in the step (1) of calculating and setting the control parameters during laser annealing is shown.

[0186] exist Fig. 9 In step S50 , the laser annealing control unit 180 calculates the transmittance Ta of the attenuator 130 at the fluence Fa which becomes the laser annealing condition.

[0187] The fluence on the surface of the irradiated object 190 is expressed by the following equation (2).

[0188] F=M -2 (T·Tp·Et) / (Bx·By) (2)

[0189] M in the formula represents the magnification of the projection optical system 150. M may be a value in the range of 1 to 1 / 5, for example.

[0190] Tp in the formula represents the transmittance of the optical system from the pulse laser light output from the laser device 20 to the irradiated object 190 when the attenuator 130 has the maximum transmittance.

[0191] Based on equation (2), the following equation (3) is obtained as a calculation equation for the transmittance Ta of the attenuator 130.

[0192] Ta=(M 2 / Tp) (Fa / Et) (Bx·By) (3)

[0193] The laser annealing control unit 180 calculates the transmittance Ta of the attenuator 130 according to equation (3).

[0194] In step S52, the laser annealing control unit 180 sets the transmittance T of the attenuator 130 to Ta. That is, the laser annealing control unit 180 controls the angles of the partial reflection mirrors 131 and 132 so that the transmittance T of the attenuator 130 becomes Ta.

[0195] Next, in step S54, the laser annealing control unit 180 calculates the absolute value Vxa of the moving speed in the X-axis direction of the XYZ-axis stage 172 during laser annealing. Vxa can be calculated using the following equation (4).

[0196] Vxa=fa·Bx / Na (4)

[0197] The derivation of formula (4) is as follows.

[0198] When the absolute value of the moving speed of the X-axis direction of the XYZ-axis stage 172 is Vxa, the number of irradiation pulses Na during laser annealing is expressed by the following equation (5).

[0199] Na=fa·Bx / Vxa (5)

[0200] Here, Na is the number of pulses of the pulsed laser irradiated at the same position (Na ≥ 2).

[0201] Therefore, the absolute value Vxa of the moving speed can be obtained from the equation (4) obtained by transforming the equation (5).

[0202] After step S54, the laser annealing control unit 180 ends Fig. 9 Flowchart of Figure 6 Flowchart of the process.

[0203] Fig.10 is shown to be applied to Figure 6 Flowchart of an example of a subroutine of step S22. That is, Fig.10 An example of the processing contents performed in the step of beam scanning irradiation during laser annealing is shown.

[0204] exist Fig.10In step S60, the laser annealing control unit 180 sets the value of parameter Xa to "Xa=1", which specifies the moving direction of the XYZ axis stage 172 with respect to the X axis. "Xa=1" means moving the XYZ axis stage 172 in the "positive direction" of the X axis.

[0205] In step S62, the laser annealing control unit 180 calculates the moving speed Vx in the X-axis direction of the XYZ-axis stage 172. Vx is determined according to the following equation (6).

[0206] Vx=Xa·Vxa (6)

[0207] In step S64, the laser annealing control unit 180 sets the parameter Vx of the moving speed in the X-axis direction of the XYZ-axis stage 172 according to the calculation result of step S62. In addition, in practice, the parameters are set corresponding to the moving distance of the beam scanning so that acceleration, uniform linear motion and deceleration are performed in a predetermined time. Here, for the sake of simplicity of description, the case where the absolute value of the speed during uniform linear motion is Vxa is exemplified.

[0208] When Vx determined by equation (6) is positive, the XYZ stage 172 is moved in the positive direction of the X axis. As a result, on the surface of the irradiated object 190 , the line beam LBa moves relative to the irradiated object 190 in the negative direction of the X axis.

[0209] In step S66, the laser annealing control unit 180 transmits a movement start signal to the XYZ axis stage 172. The movement start signal is a control signal for instructing the start of movement of the XYZ axis stage 172. In accordance with the movement start signal transmitted from the laser annealing control unit 180, the XYZ axis stage 172 starts moving.

[0210] In step S68 , the laser annealing control unit 180 outputs a light emission trigger signal at a repetition frequency fa.

[0211] In step S70, the laser annealing control unit 180 determines whether the movement of the XYZ axis stage 172 in the X-axis direction has been completed. For example, the laser annealing control unit 180 determines whether the movement has reached Figure 4 The scanning irradiation end position Spaend described in the above description. If the judgment result of step S70 is "No", the laser annealing control unit 180 returns to step S68. Steps S68 to S70 are repeated until the movement of the XYZ axis stage 172 in the X-axis direction is completed. During the period from the start of the beam scanning to the stop, during the uniform linear motion in the X-axis direction of the XYZ axis stage 172, the laser annealing control unit 180 outputs a light emission trigger signal to the laser control unit 38 at a repetition frequency fa. As a result, the pulsed laser is irradiated to the scanning irradiation area of ​​the irradiated object 190 at a repetition frequency fa.

[0212] If the result of step S70 is “yes”, that is, after the beam scanning irradiation for one scanning irradiation area is completed and the movement of the XYZ axis stage 172 in the X-axis direction is completed, the laser annealing control unit 180 proceeds to step S72 to stop outputting the light emission trigger signal. Thus, the output of the pulsed laser from the laser device 20 is stopped.

[0213] After step S72, the laser annealing control unit 180 ends Fig.10 Flowchart of Figure 6 Flowchart of the process.

[0214] 2.4 Others

[0215] In use Figure 2 to Figure 10 In the example described, the following method is shown: the imaging pattern of the mask 148 is guided to the irradiated object 190, and the imaging pattern of the mask 148 is scanned and irradiated on the surface of the irradiated object 190, thereby performing laser annealing. However, the irradiation method of the laser when performing laser annealing is not limited to this example. For example, instead of the scanning irradiation method, the following step-and-repeat method may be used: the XYZ axis stage 172 is fixed, and after reaching the irradiation pulse number Na, the XYZ axis stage 172 is moved and positioned at the next position, and the pulsed laser is irradiated.

[0216] 3.Topics

[0217] Fig.11 Schematic diagram of a method for manufacturing a semiconductor crystal thin film based on laser annealing. Here, an example of an irradiated object 190 is shown in which an amorphous silicon film 202 is arranged on a glass substrate 200. When the amorphous silicon film 202 is irradiated with a pulsed laser and laser annealing is performed, a polycrystalline silicon film 204 as a semiconductor crystal thin film is obtained by melting and polycrystallization of silicon.

[0218] However, on the surface of the crystal generated by laser annealing, in the process of melting and polycrystallizing silicon, a protrusion (raised portion) of about 50 nm called a ridge 205 is generated on the surface. For example, on the surface of a polycrystalline silicon film 204 formed by laser annealing an amorphous silicon film 202 having a film thickness of 50 nm, a ridge with a height of 50 nm to 70 nm is sometimes generated.

[0219] The ridge 205 has a significant influence on the characteristics of the semiconductor element formed using the polysilicon film 204, so it is preferable to suppress the height of the ridge 205. The problem of the ridge 205 is also described in paragraph 0052 of Japanese Patent Application Laid-Open No. 2007-287866. For example, the threshold voltage of the thin film transistor formed using the polysilicon film 204 is deviated due to the influence of the ridge 205, and it may be difficult to reduce the power supply voltage. When such a thin film transistor is applied to a liquid crystal display element, for example, it is difficult to reduce power consumption.

[0220] 4. Embodiment 1

[0221] 4.1 Outline of the method for manufacturing a semiconductor crystal thin film

[0222] Fig.12 FIG. is a schematic diagram exemplarily showing the method for manufacturing a semiconductor crystal thin film according to Embodiment 1. The method for manufacturing a semiconductor crystal thin film according to Embodiment 1 includes: irradiating an amorphous silicon film 202 with a first pulsed laser to polycrystallize the amorphous silicon (Step 1); and irradiating a ridge 205 of a polycrystalline silicon film 204 formed by irradiating the first pulsed laser with a second pulsed laser to flatten the ridge (Step 2). "Flattening the ridge" means reducing the height of the ridge.

[0223] Step 1 is a process of melting and polycrystallization based on laser annealing. Step 2 is a process of flattening the ridge of the polycrystals generated in Step 1 by laser irradiation. Here, for ease of explanation, the operation of Step 1 is referred to as "laser annealing", and the operation of Step 2 is referred to as "ridge flattening".

[0224] The irradiation conditions of the laser during laser annealing include fluence Fa, pulse time width ΔTa, and number of irradiation pulses Na.

[0225] The irradiation conditions of the laser during ridge flattening include fluence Fr, pulse time width ΔTr, and number of irradiation pulses Nr.

[0226] As the relationship between the irradiation conditions during laser annealing and the irradiation conditions during ridge flattening, it is assumed that the pulse time width ΔTr of the second pulsed laser is shorter than the pulse time width ΔTa of the first pulsed laser. That is, ΔTr < ΔTa.

[0227] When irradiating a polycrystalline Si thin film with a ridge with a pulsed laser at an appropriate pulse width and fluence, due to the electric field concentration caused by the shape effect of the ridge, the pulsed laser energy imparted to the ridge is larger than that of other regions. As a result, without melting and solidifying the entire film, by melting the ridge and its surrounding parts, it is considered that the crystalline state of the ridge is improved and the height can be controlled.

[0228] As an additional condition, it is preferably assumed that the fluence Fr of the second pulsed laser is smaller than the fluence Fa of the first pulsed laser. That is, preferably Fr < Fa. As a further additional condition, it is assumed that the number of irradiation pulses Nr of the second pulsed laser is less than the number of irradiation pulses Na of the first pulsed laser. That is, preferably Nr < Na.

[0229] That is, the laser irradiation conditions for laser annealing in step 1 are set to completely melt the amorphous silicon, and the laser irradiation conditions for ridge flattening in step 2 are set to reduce the ridge portion of the polycrystalline silicon generated by polycrystallization by laser annealing. By performing the laser irradiation in step 2, the height of the ridge 205 generated by the polycrystallization in step 1 can be reduced to a height of less than 10 nm.

[0230] 4.2 Examples related to irradiation conditions

[0231] Fig.13 This is a graph showing an example of irradiation conditions used in experiments to generate semiconductor crystal thin films. Fig.13 The combination of the irradiation conditions shown above yields a semiconductor crystal thin film in which the ridge height is suppressed to less than 10 nm. Fig.13 The pulse time width ΔTr of the full width at half maximum of the pulse laser used for ridge flattening is shown in FIG. 50％ = 14ns, which is the pulse time width ΔTa of the half-value full width of the pulse laser used for laser annealing 50％ = 35.8% of the time width of 39 ns. It is preferable that the pulse time width of the full width at half maximum of the pulse laser for ridge flattening is 40% or less of the pulse time width of the pulse laser for laser annealing.

[0232] also, Fig.13 The pulse duration ΔTr of the pulsed laser TIS used for ridge flattening is shown. TIS = 47ns becomes the pulse time width ΔTa of the TIS of the pulsed laser used for laser annealing TIS = 54.0% of the time width of 87 ns. It is preferable that the pulse time width of the TIS of the pulse laser for ridge flattening is 60% or less of the pulse time width of the TIS of the pulse laser for laser annealing.

[0233] In addition, although Fig.13 Although not shown in FIG. 1 , preferred examples of the combination of the irradiation conditions Fa and the number of irradiation pulses Na for ridge flattening include (Fa, Na) = (50, 20), (100, 10), (150, 10), (200, 1), etc. Fig.13 Similarly, the unit of the fluence Fa is millijoules per square centimeter [mJ / cm 2 ].

[0234] Fig.14 Graph showing an example of the pulse waveform of the laser used in the experiment. Fig.14 As shown in FIG. 1 , the pulse waveform during ridge flattening has a shorter pulse time width than the pulse waveform during laser annealing. Fig.14In order to compare the pulse time width, the beginnings of the two pulses are aligned for display. In fact, the second pulse laser is irradiated after the first pulse laser is irradiated to the same position (irradiation area) of the irradiated object 190. Therefore, as the timing of the irradiation of the first pulse laser and the second pulse laser to the same position of the irradiated object 190, there is a time difference between the two pulses.

[0235] That is, after the silicon film is polycrystallized by irradiation with the first pulse laser, that is, after the ridge 205 is formed, the second pulse laser is irradiated to the same area. The time for melting and polycrystallization based on the irradiation with the first pulse laser is about 200ns. Therefore, for example, after 200ns or more from the irradiation timing of the first pulse laser as the laser annealing pulse (that is, after crystallization), the second pulse laser as the ridge flattening pulse can be irradiated to the same area (place) as the irradiation area of ​​the first pulse laser. In this way, the ridge 205 formed by polycrystallization is partially melted, and the ridge 205 can be flattened.

[0236] Fig.15 A configuration example of an optical pulse stretcher (OPS) system for adjusting the pulse time width is shown. Fig.14 The pulse waveform shown in the laser annealing can be used Fig.15 The OPS system 220 is implemented. In addition, Fig.14 The pulse waveform shown in the ridge flattening can be Fig.15 The OPS system 220 is implemented by shielding a portion of the delayed optical path.

[0237] Fig.15 The OPS system 220 shown includes a first OPS 221 and a second OPS 222. The first OPS 221 and the second OPS 222 can each be Figure 2 The first OPS 221 has the same structure as the OPS system 32 described in . The first OPS 221 includes a beam splitter 230 and concave mirrors 231 to 234. The delay optical path length L(1) by the first OPS 221 is, for example, L(1) = 3 m (meter).

[0238] The second OPS 222 includes a beam splitter 240 and concave mirrors 241 to 244. The delay optical path length L(2) of the second OPS 222 is, for example, L(2)=7 m. The second OPS 222 is configured so that the laser beam transmitted through the beam splitter 230 of the first OPS 221 enters the beam splitter 240 of the second OPS 222.

[0239] The OPS system 220 is disposed on the optical path between the excimer laser device 210 and the laser annealing device 100. The excimer laser device 210 may be, for example, Figure 2 The master oscillator 30 described in FIG.

[0240] 4.3 Mask Patterning and Crystal Growth Examples

[0241] Fig.16 Examples of mask patterns and crystal growth are shown. Fig.16 An example of an image of a mask pattern and a state of a crystal after laser annealing is shown. Here, the state of a crystal after laser annealing is shown when the image of the mask pattern irradiated to the irradiated object 190 has a line width L=0.15 μm and a space width S=1 μm.

[0242] Fig.16 The left figure shows the image of the mask pattern projected onto the surface of the irradiated object 190. Fig.16 The right figure shows the state of the crystal after laser annealing at the position corresponding to the image of the mask pattern. Fig.16 The right figure is an example of an image obtained by etching away the ridge portion (grain boundary) using a scanning electron microscope (SEM) to observe a sample obtained by etching away the ridge portion. Fig.16 The lines that look like "cracks" in the right picture are grain boundaries. Fig.16 As shown, a relatively coarse grain boundary is generated approximately in the middle of the space between the mask pattern images.

[0243] After irradiating the pulse for laser annealing, for example, 200 ns or more, a pulse for ridge flattening is irradiated. As a result, the ridge is partially melted and flattened. "Flattening" means that the ridge is suppressed to a height within an allowable range (for example, less than 10 nm), that is, the flatness is improved.

[0244] 4.4 Structure of laser annealing system

[0245] Fig.17 The structure of the laser annealing system 11 according to the first embodiment is schematically shown. Fig.17 The structure shown is Figure 2 The differences are explained. Fig.17 The laser annealing system 11 shown is Figure 2 The structure of the OPS system 32 is different in that it has an optical element switching unit 82 that can replace the beam splitter 70 of the OPS system 32 with a window 80.

[0246] 4.5 Action

[0247] Action and function of laser annealing Figure 2 In the case of ridge flattening, the irradiation conditions are changed to those in the case of ridge flattening, and scanning irradiation is performed by moving in the negative direction along the X-axis of the XYZ-axis stage 172. However, when the pulse waveform is changed during laser annealing and ridge flattening, the optical element switching unit 82 of the OPS system 32 is controlled.

[0248] That is, the laser annealing control unit 180 controls the optical element switching unit 82 via the laser control unit 38 so that the beam splitter 70 is disposed on the optical path during laser annealing, and the window 80 is disposed on the optical path instead of the beam splitter 70 during ridge flattening.

[0249] Fig.18 1 is a plan view showing an example of beam scanning irradiation during ridge flattening in Embodiment 1. The line beam LBr irradiated onto the surface of the irradiated object 190 during ridge flattening includes Figure 3 An image of the line and space pattern of the mask 148 illustrated in FIG. Fig.18 As shown in FIG. 1 , the beam width of the line beam LBr irradiated to the surface of the irradiated object 190 in the X-axis direction is Bx, and the beam width in the Y-axis direction is By. By moving the XYZ-axis stage 172, the line beam LBr moves relative to the irradiated object 190. Here, by moving the XYZ-axis stage 172 in the negative direction of the X-axis, the line beam LBr moves in the positive direction of the X-axis ( Fig.18 right direction).

[0250] exist Fig.18 FIG. 1 shows a scanning irradiation state in which the line beam LBr moves from the scanning irradiation initial position SPrni to the scanning irradiation end position SPrend relative to the irradiated object 190 to irradiate the surface of the irradiated object 190 with laser light. The moving direction of the line beam LBr from the scanning irradiation initial position SPrni toward the scanning irradiation end position SPrend is referred to as the "scanning irradiation direction during ridge flattening". The scanning irradiation initial position SPrni during ridge flattening can be Figure 4 The scanning irradiation end position SpAend during the laser annealing described in the above. Fig.18 The scanning irradiation end position SPrend during ridge flattening shown in the figure can be Figure 4 The scanning irradiation initial position SPaini during the laser annealing described in .

[0251] exist Fig.18 In the embodiment, the area on the surface of the irradiated object 190 through which the line beam LBr passes, that is, the area subjected to scanning irradiation for ridge flattening, becomes a ridge flattening area 190r in which the ridge is flattened. The area not subjected to the line beam LBr, that is, the area not subjected to scanning irradiation for ridge flattening, is a crystallized area 190p containing a relatively high ridge.

[0252] By Fig.18 By further moving the line beam LBr to the scanning irradiation end position SPrend from the state shown, the entire crystallized region 190p can be converted into the ridge flattened region 190r.

[0253] 4.6 Action Examples

[0254] Fig.19 : is a flowchart showing an example of the operation of the laser annealing system 11 according to the first embodiment. Fig.19 , for Figure 6 The differences are explained. Fig.19 The flowchart shown is replaced by Figure 6 The method includes step S13 and step S21 instead of step S12 and step S20, and further, step S24, step S26 and step S28 are added after step S22.

[0255] In step S13, the laser annealing control unit 180 reads the laser irradiation condition parameters during laser annealing (2). Steps S14 to S18 after step S13 are the same as Figure 6 same.

[0256] After step S18, in step S21, the laser annealing control unit 180 calculates and sets the control parameters for laser annealing (2). Figure 6 same.

[0257] After step S22 , in step S24 , the laser annealing control unit 180 reads laser irradiation condition parameters for ridge flattening ( 1 ).

[0258] In step S26 , the laser annealing control unit 180 calculates and sets control parameters for ridge flattening ( 1 ).

[0259] In step S28, the laser annealing control unit 180 performs beam scanning irradiation for ridge flattening according to the control parameter setting in step S26. In this beam scanning irradiation, the object 190 is irradiated with pulse laser light under the conditions of the set repetition frequency fr, fluence Fr, and irradiation pulse number Nr.

[0260] After step S28, the laser annealing control unit 180 ends Fig.19 Flowchart of the process.

[0261] Fig. 20 is shown to be applied to Fig.19 This is a flowchart of an example of a subroutine of step S13. That is, Fig. 20 An example of the processing contents performed in the step (2) of reading the laser irradiation condition parameters during laser annealing is shown.

[0262] exist Fig. 20In step S32, the laser annealing control unit 180 reads the parameters of the laser annealing conditions. For example, the laser annealing control unit 180 reads the data of the fluence Fa, the number of irradiation pulses Na, the repetition frequency fa, and the pulse time width ΔTa on the irradiated object 190 during the laser annealing process. The number of irradiation pulses Na is set to an integer greater than 2. After step S32, the laser annealing control unit 180 returns to Fig.19 Flowchart of the process.

[0263] Fig.21 is shown to be applied to Fig.19 Flowchart of an example of a subroutine of step S21. That is, Fig.21 An example of the processing contents performed in the step (2) of calculating and setting the control parameters during laser annealing is shown. Fig.21 , for Fig. 9 The differences are explained. Fig.21 The flowchart shown in Fig. 9 Step S56 is further added to steps S50 to S54.

[0264] In step S56, the laser annealing control unit 180 controls the OPS system 32 according to the pulse time width ΔTa during laser annealing. The laser annealing control unit 180 controls the OPS system 32 so that the pulse time width of the pulse laser emitted from the OPS system 32 is close to the pulse time width ΔTa required as a condition during laser annealing. Fig.17 In the case of the illustrated structure, the laser annealing control section 180 controls the optical element switching unit 82 so as to arrange the beam splitter 70 on the optical path.

[0265] After step S56, the laser annealing control unit 180 ends Fig.21 Flowchart of Fig.19 Flowchart of the process.

[0266] Fig. 22 is shown to be applied to Fig.19 Flowchart of an example of a subroutine of step S24. That is, Fig. 22 An example of the processing content performed in the step (1) of reading the laser irradiation condition parameters for ridge flattening is shown. The laser irradiation condition parameters for ridge flattening are referred to as "ridge flattening condition parameters".

[0267] exist Fig. 22In step S80, the laser annealing control unit 180 reads the parameters of the ridge flattening conditions. For example, the laser annealing control unit 180 reads the data of the fluence Fr, the number of irradiation pulses Nr, the repetition frequency fr, and the pulse time width ΔTr on the irradiated object 190 during the ridge flattening process. Here, the number of irradiation pulses Nr is set to an integer greater than 1. After step S80, the laser annealing control unit 180 returns to Fig.19 Flowchart of the process.

[0268] Fig.23 is shown to be applied to Fig.19 Flowchart of an example of a subroutine of step S26. That is, Fig.23 An example of the processing contents performed in step (1) of calculating and setting the control parameters for ridge flattening is shown. Fig.23 In step S90 , the laser annealing control unit 180 calculates the transmittance Tr of the attenuator 130 at the fluence Fr that becomes the ridge flattening condition.

[0269] The transmittance Tr of the attenuator 130 can be obtained by the following equation (2) to equation (7).

[0270] Tr=(M 2 / Tp) (Fr / Et) (Bx·By) (7)

[0271] In step S92, the laser annealing control unit 180 sets the transmittance T of the attenuator 130 to Tr. That is, the laser annealing control unit 180 controls the angles of the partial reflection mirrors 131 and 132 so that the transmittance T of the attenuator 130 becomes Tr.

[0272] In step S94, the laser annealing control unit 180 calculates the absolute value Vxr of the speed at which the line beam LBr moves on the surface of the irradiated object 190 during ridge flattening. That is, the laser annealing control unit 180 calculates the absolute value Vxr of the moving speed in the X-axis direction of the XYZ-axis stage 172 during ridge flattening. Vxr can be calculated according to the following formula (8).

[0273] Vxr=fr·Bx / Nr (8)

[0274] In step S96, the laser annealing control unit 180 controls the OPS system 32 according to the pulse time width ΔTr during ridge flattening. The laser annealing control unit 180 controls the OPS system 32 so that the pulse time width of the pulse laser emitted from the OPS system 32 is close to the pulse time width ΔTr required as a condition for ridge flattening. Fig.17 In the case of the illustrated structure, the laser annealing control unit 180 controls the optical element switching unit 82 to arrange the window 80 on the optical path.

[0275] After step S96, the laser annealing control unit 180 ends Fig.23 Flowchart of Fig.19 Flowchart of the process.

[0276] Fig.24 is shown to be applied to Fig.19 This is a flowchart of an example of a subroutine of step S28. That is, Fig.24 An example of the processing contents performed in beam scanning irradiation during ridge flattening is shown. Fig.24 In step S100, the laser annealing control unit 180 sets the value of the parameter Xr to "Xr = -1", which specifies the moving direction of the XYZ axis stage 172 with respect to the X axis. "Xr = -1" means moving the XYZ axis stage 172 in the "negative direction" of the X axis.

[0277] In step S102, the laser annealing control unit 180 calculates the moving speed Vx in the X-axis direction of the XYZ-axis stage 172. Vx is determined according to the following equation (9).

[0278] Vx=Xr·Vxr (9)

[0279] In step S104, the laser annealing control unit 180 sets the parameter Vx of the moving speed in the X-axis direction of the XYZ axis stage 172 according to the calculation result of step S102. In addition, in practice, the parameters are set corresponding to the moving distance of the beam scanning so that acceleration, uniform linear motion and deceleration are performed in a predetermined time. Here, for the sake of simplicity of description, the case where the absolute value of the speed during uniform linear motion is Vxr is exemplified.

[0280] In step S106, the laser annealing control unit 180 sends a movement start signal to the XYZ axis stage 172. When Vx determined by equation (9) is negative, the XYZ axis stage 172 is moved in the negative direction of the X axis. As a result, on the surface of the irradiated object 190, the line beam LBr moves relative to the irradiated object 190 in the positive direction of the X axis.

[0281] exist Fig.24 In step S108, the laser annealing control unit 180 outputs a light emission trigger signal at a repetition frequency fr.

[0282] In step S110, the laser annealing control unit 180 determines whether the movement of the XYZ axis stage 172 in the X-axis direction has been completed. The laser annealing control unit 180 determines whether the movement of the XYZ axis stage 172 in the X-axis direction has been completed. Fig.18The scanning irradiation end position SPrend shown in FIG. 1 is a scanning irradiation end position SPrend. If the judgment result of step S110 is "No", the laser annealing control unit 180 returns to step S108. Steps S108 to S110 are repeated until the movement of the XYZ axis stage 172 in the X-axis direction is completed. During the uniform linear motion of the XYZ axis stage 172 in the X-axis direction, the laser annealing control unit 180 outputs a light emission trigger signal to the laser control unit 38 at a repetition frequency fr. As a result, the pulsed laser is irradiated to the scanning irradiation area of ​​the irradiated object 190 at a repetition frequency fr.

[0283] If the result of step S110 is “yes”, that is, after the beam scanning irradiation for one scanning irradiation area is completed and the movement of the XYZ axis stage 172 in the X-axis direction is completed, the laser annealing control unit 180 proceeds to step S112 to stop outputting the emission trigger signal. Thus, the output of the pulsed laser from the laser device 20 is stopped.

[0284] After step S112, the laser annealing control unit 180 ends Fig.24 Flowchart of Fig.19 Flowchart of the process.

[0285] 4.7 Effects

[0286] According to the laser annealing system 11 of the first embodiment, by controlling the OPS system 32, one laser device can output two types of pulse lasers having different pulse time widths, and laser annealing and ridge flattening can be performed using the two types of pulse lasers.

[0287] The laser device 20 in Embodiment 1 is an example of a “laser system” in the present disclosure. The master oscillator 30 is an example of a “laser oscillator” in the present disclosure. The XYZ axis stage 172 is an example of a “moving mechanism” in the present disclosure. The laser annealing control unit 180 is an example of a “control unit” in the present disclosure. The optical system including the illumination optical system 140 of the irradiation optical system 110 and the projection optical system 150 is an example of an “irradiation optical system” in the present disclosure. The beam splitter 70 and the window 80 of the optical element switching unit 82 are examples of “optical elements” in the present disclosure, respectively. The projection optical system 150 is an example of a “transfer optical system” in the present disclosure. The amorphous silicon film 202 is an example of an “amorphous semiconductor” in the present disclosure. The region that is irradiated with the line beam LBa for laser annealing and polycrystallized is an example of a “semiconductor crystal region” in the present disclosure. The polycrystalline silicon film 204 is an example of a “semiconductor crystal” and a “semiconductor crystal thin film” in the present disclosure. The line beam LBa irradiated to the irradiated object 190 is an example of the “illumination pattern of the first pulse laser” in the present disclosure, and the line beam LBr irradiated to the irradiated object 190 is an example of the “illumination pattern of the second pulse laser” in the present disclosure. The pulse time width ΔTa of the pulse laser used for laser annealing is an example of the “first pulse time width” in the present disclosure. The pulse time width ΔTr of the pulse laser used for ridge flattening is an example of the “second pulse time width” in the present disclosure.

[0288] 4.8 Variations

[0289] (1) In the first embodiment, the case where only one OPS 33 is used in the OPS system 32 is shown. However, Fig.15 In this case, the OPS system may be configured to include a plurality of optical pulse stretchers. In this case, an optical element switching unit similar to the optical element switching unit 82 may be provided for each of the plurality of optical pulse stretchers provided in the OPS system to control switching of the optical elements.

[0290] (2) In the first embodiment, an example is shown in which the OPS system 32 is arranged in the laser device 20 . However, the OPS system 32 may be arranged on the optical path between the laser annealing apparatus 100 and the laser device 20 .

[0291] (3) In Embodiment 1, a method of performing laser annealing and ridge flattening by performing beam scanning irradiation in which the imaging pattern of the mask 148 is moved on the irradiated object 190 is shown, but the present invention is not limited to this example. For example, in laser annealing, laser irradiation may be performed by a step-and-repeat method under the irradiation conditions in laser annealing, and then in ridge flattening, laser irradiation may be performed by a step-and-repeat method under the irradiation conditions in ridge flattening.

[0292] 5. Implementation Method 2

[0293] 5.1 Structure

[0294] Fig.25 The structure of the laser annealing system 12 according to the second embodiment is schematically shown. Fig.25 The structure shown is Fig.17 The differences are explained. Fig.25 The laser annealing system 12 shown is Fig.17 The structure differs in that instead of Fig.17 The optical element switching unit 82 is provided, and a gate 84 for opening and closing the delay optical path is arranged on the delay optical path of OPS33. Fig.17 The laser annealing control unit 180 controls the opening and closing operation of the gate 84 via the laser control unit 38 .

[0295] The reflectivity of the beam splitter 70 of the OPS 33 is preferably 55% to 65%, and more preferably 60%.

[0296] 5.2 Action

[0297] The laser annealing control unit 180 outputs a delay optical path opening and closing control signal for operating the shutter 84. The delay optical path opening and closing control signal sent from the laser annealing control unit 180 is sent to a driving unit of the shutter 84 via the laser control unit 38.

[0298] During laser annealing, a control signal for opening the gate 84 is sent from the laser annealing control unit 180. After the gate 84 is opened, the pulse laser after pulse stretching by the OPS 33 is irradiated to the irradiated object 190. The pulse laser after pulse stretching by the OPS 33 is an example of the "first pulse laser" in the present disclosure.

[0299] During ridge flattening, a control signal for closing the gate 84 is sent from the laser annealing control unit 180. After the gate 84 is closed, the delay optical path of the OPS 33 is shielded, and thus the pulse laser light that is not pulse stretched by the OPS 33 is irradiated to the irradiated object 190. The pulse laser light that is not pulse stretched by the OPS 33, that is, the pulse laser light that is transmitted through the beam splitter 70 when the gate 84 is in the closed state, is an example of the "second pulse laser light" in the present disclosure.

[0300] 5.3 Effects

[0301] According to the laser annealing system 12 of the second embodiment, it is possible to switch between irradiation with the pulsed laser for laser annealing and the pulsed laser for ridge flattening simply by controlling the opening and closing operation of the gate 84 .

[0302] In addition, the fluence Fr during ridge flattening is smaller than the fluence Fa during laser annealing (Fr < Fa). Therefore, even when the shutter 84 is closed, irradiation can be performed with the desired fluence Fr during ridge flattening.

[0303] 6. Embodiment 3

[0304] 6.1 Structure

[0305] Fig.26 The structure of the laser annealing system 13 according to Embodiment 3 is schematically shown. Regarding Fig.26 the structure shown, the differences from Fig.17 will be described. The laser annealing system 13 according to Embodiment 3 includes a first laser device 21 that outputs a first pulsed laser for laser annealing, a second laser device 22 that outputs a second pulsed laser for ridge flattening, a first optical path tube 26, and a second optical path tube 27. The first laser device 21 and the first optical path tube 26 may have the same structure as the laser device 20 and the optical path tube 25 described in Fig.17 . The first optical path tube 26 is disposed on the optical path of the laser between the laser output port of the first laser device 21 and the first laser input port of the laser annealing device 100.

[0306] The second laser device 22 outputs a second pulsed laser having a pulse time width shorter than the pulse time width of the first pulsed laser output from the first laser device 21. The second laser device 22 may also be a laser device having a structure obtained by deleting the OPS system 32 from the structure of the first laser device 21.

[0307] The second optical path tube 27 is disposed on the optical path of the laser between the laser output port of the second laser device 22 and the second laser input port of the laser annealing device 100.

[0308] The irradiation optical system 113 of the laser annealing system 13, based on the structure of the irradiation optical system 110 described in Fig.17 , is supplemented with high - reflection mirrors 321 to 323, an attenuator 330, and an illumination optical system 340 to irradiate the object 190 with the second pulsed laser for ridge flattening.

[0309] The high - reflection mirror 321 is configured such that the laser passing through the second optical path tube 27 enters the high - reflection mirror 322 through the attenuator 330.

[0310] The attenuator 330 is disposed on the optical path between the high - reflection mirror 321 and the high - reflection mirror 322. The attenuator 330 includes two partial - reflection mirrors 331 and 332, and rotating tables 335 and 336 that can vary the incident angles of the respective partial - reflection mirrors 331 and 332.

[0311] The high reflection mirror 322 is arranged so that the laser light after passing through the attenuator 330 is incident on the high reflection mirror 323. The high reflection mirror 323 is arranged so that the incident pulse laser light is incident on the fly-eye lens 345 of the illumination optical system 340.

[0312] The illumination optical system 340 includes a fly-eye lens 345 and a condenser lens 346. The illumination optical system 340 is an optical system for uniformly illuminating a predetermined illumination region on the mask 148, and is configured to perform Kohler illumination on the mask 148 using a rectangular beam.

[0313] For example, the fly-eye lens 345 is arranged so that the focal plane of the fly-eye lens 345 coincides with the front focal plane of the condenser lens 346 , and the condenser lens 346 is arranged so that the rear focal plane of the condenser lens 346 coincides with the position of the mask 148 .

[0314] The line beam LBa for laser annealing irradiated to the surface of the irradiated object 190 via the illumination optical system 140 and the projection optical system 150 is set to have a beam width of Bya in the Y-axis direction and a beam width of Bxa in the X-axis direction on the surface of the irradiated object 190. In addition, the line beam LBr for ridge flattening irradiated to the surface of the irradiated object 190 via the illumination optical system 340 and the projection optical system 150 is set to have a beam width of Byr in the Y-axis direction and a beam width of Bxr in the X-axis direction on the surface of the irradiated object 190. Furthermore, the number of irradiation pulses during laser annealing is set to Na, and the number of irradiation pulses during ridge flattening is set to Nr. In the case of the third embodiment, the illumination optical system 140 and the illumination optical system 340 are configured so that Bya and Byr are the same (Bya=Byr), and Bxa and Bxr are the ratio of Na to Nr (Bxa:Bxr=Na:Nr).

[0315] For example, the fly-eye lenses 145 of the illumination optical system 140 and the fly-eye lenses 345 of the illumination optical system 340 may have the same pitch interval in the Y-axis direction, and the ratio of the pitch interval in the X-axis direction may be the same as the ratio of Na to Nr. Furthermore, the focal lengths of the condenser lenses 146 and 346 of the illumination optical system 140 and the illumination optical system 340 may be the same.

[0316] 6.2 Action

[0317] The operation of laser annealing by irradiating the object 190 with the pulsed laser output from the first laser device 21 is similar to the operation of Figure 2The laser annealing control unit 180 transmits and receives various data and signals such as target pulse energy with a laser control unit (not shown) of the second laser device 22. The laser annealing control unit 180 transmits a light emission trigger signal Tr2 to the second laser device 22 in synchronization with the light emission trigger signal Tr1 of the first laser device 21.

[0318] The pulse laser light output from the second laser device 22 passes through the second optical path tube 27 , is reflected by the high reflection mirror 321 , and enters the attenuator 330 .

[0319] The pulse laser light transmitted through the attenuator 330 enters the illumination optical system 340 via the high reflection mirrors 322 and 323 .

[0320] The pulse laser light transmitted through the illumination optical system 340 has a rectangular beam shape, is shaped into a line beam with uniform light intensity, and is irradiated onto the mask 148 .

[0321] Fig. 27 1 is a top view showing an example of the relationship between the pattern of the mask 148 and the line beams LBam and LBrm for illuminating the mask 148. Fig. 27 As shown, the line beam LBam for laser annealing and the line beam LBrm for ridge planarization are irradiated onto the mask 148, respectively.

[0322] The laser annealing control unit 180 controls the transmittance of the attenuator 130 so that the fluence of the line beam LBa for laser annealing on the surface of the irradiated object 190 becomes Fa. In addition, the laser annealing control unit 180 controls the transmittance of the attenuator 330 so that the fluence of the line beam LBr for ridge flattening on the surface of the irradiated object 190 becomes Fr.

[0323] The moving speed Vxa of the XYZ-axis stage 172 in the X-axis direction during laser annealing is calculated using the following equation (10).

[0324] Vxa=fa·Bxa / Na (10)

[0325] The moving speed Vxr of the XYZ-axis stage 172 in the X-axis direction during ridge flattening is expressed by the following equation (11).

[0326] Vxr=fr·Bxr / Nr (11)

[0327] Here, by setting the repetition frequency fa=fr and R=Bxa / Bxr=Na / Nr, Vxa=Vxr is achieved.

[0328] Fig.28 1 is a top view showing an example of scanning irradiation of the object 190 with a line beam. Fig.28As shown, by scanning and irradiating the object 190 with two line beams, namely, the line beam LBa for laser annealing and the line beam LBr for ridge flattening, laser annealing and ridge flattening can be performed.

[0329] The line beam LBa for laser annealing irradiated to the surface of the irradiated object 190 is Fig. 27 The imaging pattern of lines and spaces of the mask 148 illustrated in FIG. Fig.28 As shown, the beam width of the line beam LBa for laser annealing irradiated to the surface of the irradiated object 190 in the X-axis direction is Bxa, and the beam width in the Y-axis direction is Bya. The beam width of the line beam LBr for ridge flattening irradiated to the surface of the irradiated object 190 in the X-axis direction is Bxr, and the beam width in the Y-axis direction is Byr. Here, Bya=Byr.

[0330] By moving the XYZ-axis stage 172, the two line beams LBa and LBr move relative to the irradiated object 190. By moving the XYZ-axis stage 172 in the positive direction of the X-axis, the line beams LBa and LBr move in the negative direction of the X-axis ( Fig.28 The line beam LBa for laser annealing moves from the scanning irradiation initial position SPaini to the scanning irradiation end position SPaend relative to the irradiated object 190. The line beam LBr for ridge flattening follows the movement of the line beam LBa for laser annealing and moves from the scanning irradiation initial position SPrini to the scanning irradiation end position SPrend relative to the irradiated object 190.

[0331] exist Fig.28 In the above, the area on the surface of the irradiated object 190 where the line beam LBa does not pass, that is, the area where the scanning irradiation is not performed, is an amorphous area 190a that has not been irradiated with laser light and is still in an amorphous (non-crystalline) state. The area on the surface of the irradiated object 190 where the line beam LBa passes becomes a crystallized area 190p obtained by polycrystallizing silicon through crystal growth. The area on the surface of the irradiated object 190 where the line beam LBr for ridge flattening passes becomes a ridge flattened area 190r where the ridge is flattened. The area on the surface of the irradiated object 190 where the line beam LBa for laser annealing passes and the line beam LBr for ridge flattening does not pass is a crystallized area 190p that still contains a ridge.

[0332] When the position of the line beam LBr for ridge flattening relative to the irradiated object 190 reaches the scanning irradiation end position SPrend (refer to Fig.28 ) after which the movement of the XYZ axis stage 172 is stopped.

[0333] 6.3 Effects

[0334] The laser annealing system 13 of the third embodiment has the following effects as compared to the laser annealing system 11 of the first embodiment.

[0335] [1] By shaping the two line beams for laser annealing and ridge flattening respectively by the illumination optical systems 140 and 340 to set R=Bxa / Bxr=Na / Nr, the attenuation amount of the attenuator 330 during ridge flattening can be reduced. This improves the utilization efficiency of the pulsed laser.

[0336] [2] With respect to the X-axis direction of the XYZ-axis stage 172 , laser annealing and ridge flattening can be performed by only one scanning irradiation operation, thereby improving throughput.

[0337] The combination of the first laser device 21 and the second laser device 22 in the third embodiment is an example of a “laser system” in the present disclosure.

[0338] 7. Implementation Method 4

[0339] 7.1 Structure

[0340] Fig.29 The structure of the laser annealing system 14 according to the fourth embodiment is schematically shown. Fig.29 The structure shown is Fig.26 The differences are explained. Fig.29 The laser annealing system 14 shown replaces Fig.26 The first laser device 21 and the second laser device 22 include a laser device 23 and a branch system 250.

[0341] The laser device 23 is an excimer laser device that does not include an OPS system. The laser device 23 may be, for example, Figure 2 The laser device 20 described above has a structure in which the OPS system 32 is removed, and includes a master oscillator 30 , a monitor module 34 , and a laser control unit 38 .

[0342] The third optical path tube 28, the branch system 250, the first optical path tube 26 and the second optical path tube 27 are arranged on the optical path between the laser device 23 and the laser annealing device 100. The third optical path tube 28 is arranged on the optical path of the laser light between the laser output port of the laser device 23 and the laser input port of the branch system 250.

[0343] The branching system 250 includes a beam splitter 254 , an OPS system 32 , and a high-reflection mirror 257 .

[0344] The beam splitter 254 is arranged on the optical path of the laser light between the laser device 23 and the OPS system 32. The beam splitter 254 is coated with a partial reflection film. The reflected light reflected by the beam splitter 245 is arranged to be incident on the high reflection mirror 321 of the laser annealing device 100 via the high reflection mirror 257 and the second optical path tube 27.

[0345] The reflectivity R4 of the beam splitter 254 is a value close to the reflectivity calculated by the following equation (12).

[0346] R4=By·Bxa·Fa / (By·Bxr·Fr)

[0347] =(Bxa·Fa) / (Bxr·Fr) (12)

[0348] The OPS system 32 is disposed between the high reflection mirror 121 of the laser annealing apparatus 100 and the beam splitter 254 on the optical path of the light transmitted through the beam splitter 254 .

[0349] 7.2 Action

[0350] The laser annealing control unit 180 transmits a light emission trigger signal Tr3 to the laser device 23. The pulse laser light output from the laser device 23 enters the branch system 250.

[0351] The pulse laser light reflected by the beam splitter 254 is not pulse-stretched, but enters the high reflection mirror 321 through the high reflection mirror 257 and the second optical path tube 27. The pulse laser light highly reflected by the high reflection mirror 321 enters the attenuator 330.

[0352] The pulse laser light transmitted through the attenuator 330 enters the illumination optical system 340 via the high reflection mirrors 322 and 323 .

[0353] The pulsed laser beam after passing through the illumination optical system 340 has a rectangular beam shape, is shaped into a line beam whose light intensity is uniform in space, and is irradiated onto the mask 148 as the line beam LBrm for ridge flattening. The relationship between the line beam LBrm and the pattern of the mask 148 is as follows: Fig. 27 same.

[0354] On the other hand, the pulse laser light transmitted through the beam splitter 254 of the branching system 250 is pulse-stretched by the OPS system 32 , and enters the illumination optical system 140 via the high reflection mirror 121 , the attenuator 130 , and the high reflection mirrors 122 and 123 .

[0355] The pulsed laser beam after passing through the illumination optical system 140 has a rectangular beam shape, is shaped into a line beam whose light intensity is spatially uniform, and is irradiated onto the mask 148 as the line beam LBam for laser annealing. The relationship between the line beam LBam and the pattern of the mask 148 is as follows: Fig. 27 same.

[0356] Operation and reference of scanning irradiation for laser annealing and ridge flattening of the irradiated object 190 in the laser annealing system 14 Fig.28 The scanning irradiation operation of the third embodiment described above is the same.

[0357] 7.3 Effects

[0358] The laser annealing system 14 of the fourth embodiment and Fig.26 Compared with the structure of the third embodiment, laser annealing and ridge flattening can be performed using one laser device 23.

[0359] In addition, the laser annealing system 14 of the fourth embodiment is different from the first embodiment ( Fig.17 ) and implementation mode 2 ( Fig.25 ) compared to the above, by setting the reflectivity R4 of the beam splitter 254 to a reflectivity close to the value of equation (12), the utilization efficiency of the pulsed laser is improved.

[0360] The laser device 23 in the fourth embodiment is an example of the "third laser device" in the present disclosure. The combination of the laser device 23 and the branch system 250 is an example of the "laser system" in the present disclosure.

[0361] 7.4 Variations

[0362] (1) Fig.29 In the fourth embodiment shown, the branch system 250 is disposed between the laser annealing apparatus 100 and the laser apparatus 23 . However, the present invention is not limited to this example. For example, the branch system 250 may be disposed in the laser apparatus 23 or in the laser annealing apparatus 100 .

[0363] (2) As long as the pulse energy of the pulse laser of the laser device 23 is within the control range, the attenuator 330 may not be provided.

[0364] 8. Implementation Method 5

[0365] 8.1 Structure

[0366] Fig.30 The structure of the laser annealing system 15 according to the fifth embodiment is schematically shown. Fig.30 The structure shown is Fig.29 The differences are explained. Fig.30 The laser annealing system 15 shown replaces Fig.29 The laser device 23 and the branching system 250 include the laser device 24 and the polarization branching system 251.

[0367] The laser device 24 is an excimer laser device that does not include an OPS system, and is a laser device that outputs linearly polarized pulse laser light perpendicular to the XZ plane.

[0368] Two windows (not shown) in the optical resonator of the laser device 24 may be arranged at the Brewster angle so that polarized light perpendicular to the XZ plane becomes P polarized light.

[0369] A polarization branching system 251 is arranged on the optical path between the laser device 24 and the laser annealing device 100. Fig.30 In the laser annealing system 15 shown, Fig.29 The second optical path tube 27 shown is deleted.

[0370] The polarization branching system 251 includes a retarder 255 and the OPS system 32. The retarder 255 is arranged on the optical path between the OPS system 32 and the laser device 24.

[0371] The retarder 255 is a λ / 2 plate. The material of the retarder 255 is, for example, crystal, MgF 2 The retarder 255 further includes a rotating stage 256 for rotating an angle θ between the optical axis of the retarder 255 and the polarization plane of the pulsed laser light incident on the retarder 255 .

[0372] The OPS system 32 is arranged on the optical path of the laser light between the laser device 24 and the laser annealing device 100. The beam splitter 70p arranged in the OPS system 32 is coated with a film that partially reflects the S polarization component and highly transmits the P polarization component, and is arranged so that the polarization component perpendicular to the XZ plane becomes S polarization light.

[0373] Illumination optical system 114 is deleted Fig.29 Instead of the high reflection mirrors 121 and 321, a polarization beam splitter 324 and a high reflection mirror 325 are added.

[0374] Polarization beam splitter 324 is arranged to convert pulsed laser light having a polarization plane perpendicular to the XZ plane into S-polarized light, which is incident on attenuator 130. Polarization beam splitter 324 is coated with a film that highly reflects S-polarized light and highly transmits P-polarized light.

[0375] The high reflective mirror 325 is arranged to reflect the light transmitted through the polarization beam splitter 324 , and the reflected light is incident on the attenuator 330 .

[0376] 8.2 Action

[0377] The pulse laser light having a polarization plane perpendicular to the XZ plane is output from the laser device 24 . The pulse laser light output from the laser device 24 is incident on the delay device 255 .

[0378] The polarization plane of the pulse laser light is rotated by 2θ by the delay device 255. The pulse laser light after the polarization plane rotation enters the beam splitter 70p.

[0379] A portion of the pulse laser light having a polarization component perpendicular to the XZ plane is reflected by the beam splitter 70 p of the OPS system 32 , and the other portion is transmitted through the beam splitter 70 p , and thus is pulse-stretched by the OPS system 32 .

[0380] On the other hand, the pulse laser light including the polarization component in the XZ plane is highly transmitted through the beam splitter 70 p and is not pulse-broadened.

[0381] The pulsed laser light after passing through the OPS system 32 enters the polarization beam splitter 324 of the irradiation optical system 114. The polarization component perpendicular to the XZ plane after pulse expansion by the OPS system 32 is highly reflected by the polarization beam splitter 324 and enters the illumination optical system 140 via the attenuator 130 and the high reflection mirrors 122 and 123.

[0382] The pulsed laser light transmitted through the illumination optical system 140 is shaped into a rectangular line beam with a uniform intensity distribution, and is irradiated onto a mask 148 for laser annealing.

[0383] On the other hand, the polarization component including the XZ plane that is not pulse-broadened by the OPS system 32 is highly transmitted through the polarization beam splitter 324 , and enters the illumination optical system 340 via the high reflection mirror 325 , the attenuator 330 , and the high reflection mirrors 322 and 323 .

[0384] The pulsed laser light transmitted through the illumination optical system 340 is shaped into a rectangular line beam with uniform intensity distribution, and is irradiated onto the mask 148 for ridge flattening.

[0385] The operation of irradiating the pulsed laser light for laser annealing and the pulsed laser light for ridge flattening, which have passed through the mask 148 , onto the irradiated object 190 via the projection optical system 150 is the same as that of the fourth embodiment.

[0386] The laser annealing control unit 180 rotates the delay device 255 so that the ratio Rab of the pulse energy Ea of the pulse laser with a polarization component perpendicular to the XZ plane after passing through the delay device 255 and the pulse energy Eb of the pulse laser including the polarization component of the XZ plane becomes the relationship expressed by the following equation (13).

[0387] Rab=Ea / Eb=By·Bxa·Fa / (By·Bxr·Fr)

[0388] =(Bxa·Fa) / (Bxr·Fr) (13)

[0389] 8.3 Action / Effect

[0390] Fig.30 Embodiment 5 shown and Fig.26 Compared with embodiment 3, laser annealing and ridge flattening can be performed using one laser device.

[0391] Fig.30 Embodiment 5 shown and Fig.26 Compared with the third embodiment, the optical axis of the delay device 255 is rotated to adjust the ratio of the pulse laser for laser annealing and the pulse laser for ridge flattening, thereby improving the utilization efficiency of the pulse laser.

[0392] Furthermore, when the irradiation conditions during laser annealing and ridge flattening are changed, the utilization efficiency of the pulsed laser light can be optimized by adjusting the ratio between the pulsed laser light for laser annealing and the pulsed laser light for ridge flattening.

[0393] The combination of the laser device 24 and the polarization branching system 251 in Embodiment 5 is an example of a “laser system” in the present disclosure. The laser device 24 is an example of a “fourth laser device” in the present disclosure. The polarization component perpendicular to the XZ plane is an example of a “first polarization component” in the present disclosure. The polarization component including the XZ plane is an example of a “second polarization component” in the present disclosure.

[0394] 8.4 Variations

[0395] [1] In Embodiment 5, the polarization branching system 251 is disposed between the laser annealing apparatus 100 and the laser apparatus 24. However, the present invention is not limited to this example. For example, the polarization branching system 251 may be disposed in the laser apparatus 24 or in the laser annealing apparatus 100.

[0396] [2] As long as the pulse energy of the pulse laser of the laser device 24 is within the control range, the attenuator 330 may not be provided.

[0397] [3] By adjusting the rotation angle of the delay device 255, the ratio Rab of the pulse energy Ea of the pulse laser with a polarization component perpendicular to the XZ plane to the pulse energy Eb of the pulse laser with a polarization component including the XZ plane can be adjusted. Therefore, it is also possible to configure the attenuator 130, 330 to be omitted.

[0398] 9. Implementation Method 6

[0399] 9.1 Structure

[0400] Fig.31 The structure of the laser annealing system 16 according to the sixth embodiment is schematically shown. In the sixth embodiment, an example is shown in which laser annealing is performed locally on a region where a TFT is to be formed on an object 190 to be irradiated using the projection optical system 151. Fig.31 The structure shown is Fig.26 The differences are explained.

[0401] Fig.31 The irradiation optical system 115 of the laser annealing system 16 shown replaces Fig.26 The illumination optical system 140, 340 includes the illumination optical system 141, 341. In addition, the laser annealing system 16 replaces Fig.26 The mask 148 and the projection optical system 150 include a mask 149 and a projection optical system 151.

[0402] The first pulse laser light for laser annealing outputted from the first laser device 21 enters the illumination optical system 141 via the high reflection mirror 121 , the attenuator 130 , and the high reflection mirrors 122 and 123 .

[0403] The second pulse laser light for ridge flattening outputted from the second laser device 22 enters the illumination optical system 341 via the high reflection mirror 321 , the attenuator 330 , and the high reflection mirrors 322 and 323 .

[0404] The illumination optical systems 141 and 341 are respectively optical systems for uniformly illuminating a predetermined illumination area on the mask 149 , and are arranged so as to perform Kohler illumination on the mask 149 with a rectangular beam.

[0405] Fig.32 2 shows an example of a mask 149 and an irradiation area of ​​the beam directed to the mask 149. Fig.32 As shown, the mask 149 includes a plurality of pattern regions 149pa and a shielding region 149sh for forming a plurality of TFTs. The plurality of pattern regions 149pa are respectively formed with the same fine pattern for promoting crystal growth (see Fig.33 ).

[0406] exist Fig.32 2 shows a uniform illumination area LB1m by the illumination optical system 141 and a uniform illumination area LB2m by the illumination optical system 341. The uniform illumination area LB1m is an illumination area of ​​a uniform beam for laser annealing, and the uniform illumination area LB2m is an illumination area of ​​a uniform beam for ridge flattening.

[0407] The number of pattern regions 149pa in the X-axis direction within the uniform illumination area LB1m by the illumination optical system 141 corresponds to the number of irradiation pulses Na during laser annealing. The number of pattern regions 149pa in the X-axis direction within the uniform illumination area LB2m by the illumination optical system 341 corresponds to the number of irradiation pulses Nr during ridge flattening.

[0408] exist Fig.32For simplicity, an example of the case where Na=4 and Nr=3 is shown. In addition, for example, when Na=20 and Nr=10, the number of pattern regions 149pa arranged in the X-axis direction of the mask 149 is set to 30, the number of pattern regions 149pa in the X-axis direction within the uniform illumination area LB1m based on the illumination optical system 141 is set to 20, and the number of pattern regions 149pa in the X-axis direction within the uniform illumination area LB2m based on the illumination optical system 341 is set to 10.

[0409] In addition, the number of pattern regions 149pa in the Y-axis direction in each of the uniform illumination region LB1m by the illumination optical system 141 and the uniform illumination region LB2m by the illumination optical system 341 is the same. Fig.32 , the number of pattern regions 149 pa in the Y-axis direction is five, but the present invention is not limited to this example, and any number may be used as long as the beam injection during laser annealing can be maintained.

[0410] Fig.33 is an enlarged view showing an example of a fine pattern formed in the pattern area 149pa. The fine pattern may be Fig.33 The line portions 149L and the space portions 149S are shown in a line and space pattern in which the line portions 149L and the space portions 149S are alternately arranged.

[0411] The fine pattern formed in the pattern area 149pa can be any fine pattern formed by forming a crystal nucleus corresponding to the fine pattern by laser annealing and growing a crystal, for example, a fine pattern formed by forming dots arranged at the same pitch in the X-axis direction and the Y-axis direction.

[0412] Fig.31 The projection optical system 150 shown is arranged to image the fine pattern of each pattern region 149pa of the mask 149 on the TFT formation region on the amorphous silicon on the irradiated object 190. In this case, the fine pattern of the pattern region 149pa is projected onto the irradiated object 190.

[0413] 9.2 Action

[0414] The laser annealing control unit 180 controls the first laser device 21 and the attenuator 130 so that the fluence of the pulsed laser for laser annealing becomes Fa. The laser annealing control unit 180 controls the second laser device 22 and the attenuator 330 so that the fluence of the pulsed laser for ridge flattening becomes Fr.

[0415] The laser annealing control unit 180 calculates the velocity Vx of the X-axis direction of the XYZ-axis stage 172 so that the following equation (14) holds true.

[0416] Vx=p·f (14)

[0417] Here, p is the spacing in the X-axis direction of the TFT formation regions on the irradiated object 190 (see Fig.34 ). f is the repetition frequency of the first laser device 21 and the second laser device 22. Here, the repetition frequencies of the first laser device 21 and the second laser device 22 are set to be the same f.

[0418] The laser annealing control unit 180 sets the speed of the X-axis direction of the XYZ-axis stage 172 so that the XYZ-axis stage 172 performs a uniform linear motion at a speed Vx.

[0419] Fig.34 This is an explanatory diagram of the operation of the laser annealing system 16 according to Embodiment 6. The laser annealing control unit 180 synchronously sends emission trigger signals Tr1 and Tr2 to the first laser device 21 and the second laser device 22, respectively, so that when each pattern transfer image reaches the TFT formation area on the surface of the irradiated object 190, the object is irradiated with laser light.

[0420] The pulsed laser light for laser annealing outputted from the first laser device 21 and having pulses stretched therein is irradiated to each TFT formation region on the surface of the irradiated object 190 under the irradiation conditions of the fluence Fa, the number of irradiation pulses Na and the repetition frequency f. As a result, the amorphous silicon in the TFT formation region is annealed by the laser, and crystals grow to form ridges.

[0421] Then, the TFT formation area of ​​each crystallized polysilicon is irradiated with pulsed laser for ridge flattening (pulsed laser without pulse broadening) output from the second laser device 22 under the irradiation conditions of injection amount Fr, number of irradiation pulses Nr and repetition frequency f, and the ridge is flattened.

[0422] exist Fig.34 In FIG. 1 , 50 quadrilateral regions arranged in 5 rows and 10 columns represent TFT formation regions where TFTs are formed. Fig.34 The right side of the left side is irradiated with a beam of a transfer pattern image for laser annealing and a beam of a transfer pattern image for ridge flattening.

[0423] Fig.34The 5×4=20 quadrilateral regions in the 4 columns from the left represent the pulse irradiation parts for laser annealing. The pulse irradiation parts for laser annealing are irradiated with the pulse laser for laser annealing, and the amorphous silicon undergoes crystal growth to form ridges. The quadrilateral regions in the first column from the left represent TFT formation regions obtained by only one pulse irradiation for laser annealing. The quadrilateral regions in the second column from the left represent TFT formation regions obtained by two pulse irradiations for laser annealing. The third column represents the TFT formation region obtained by three pulse irradiations, and the fourth column represents the TFT formation region obtained by four pulse irradiations.

[0424] When the number of irradiation pulses Na during laser annealing is set to Na=4, pulse irradiation of the pulsed laser light for laser annealing is performed four times on one (same) TFT formation region.

[0425] Fig.34 The 5×3=15 quadrilateral regions in the 5th, 6th, and 7th columns from the left in the figure represent the ridge flattening pulse irradiation portions. The ridge flattening pulse irradiation portions are regions that have been crystallized by the previous laser annealing pulse irradiation (irradiation pulse number Na), and are irradiated with the ridge flattening pulse laser, so that the ridge portion is melted and the ridge is flattened.

[0426] The TFT formation region in the fifth column is a region where the number of pulse irradiation of the pulse laser for ridge flattening is the first time. The TFT formation region in the sixth column is a TFT formation region obtained by performing pulse irradiation for ridge flattening twice. The TFT formation region in the seventh column is a TFT formation region obtained by performing pulse irradiation for ridge flattening three times. When the number of irradiation pulses Nr during ridge flattening is Nr=3, pulse irradiation of the pulse laser for ridge flattening is performed three times on one (same) TFT formation region.

[0427] Fig.34 5×3=15 TFT formation regions in three columns from the right in show TFT formation regions after Na times of pulse irradiation for laser annealing and Nr times of pulse irradiation for ridge flattening.

[0428] In addition, Fig.34 In the figure, the region other than the TFT formation region is an amorphous portion that is not irradiated with laser light.

[0429] 9.3 Effects

[0430] Implementation 6 and Fig.17Compared with the first embodiment described in the embodiment 1, the present invention has the following effects: That is, the mask pattern is reduced by the projection optical system 151 and transferred to the TFT formation area on the irradiated object 190 for imaging, and the pulsed laser for laser annealing and the pulsed laser for ridge flattening can be irradiated, so the utilization efficiency of the pulsed laser is improved.

[0431] 9.4 Variations

[0432] [1] In Embodiment 6, a structure using two laser devices, namely, a first laser device 21 and a second laser device 22, is shown. The first laser device 21 outputs a pulse laser with a relatively long pulse time width for laser annealing, and the second laser device 22 outputs a pulse laser with a relatively short pulse time width for ridge flattening. However, the present invention is not limited to this example. For example, it is also possible to replace Fig.31 The first laser device 21 and the second laser device 22 are configured Fig.29 The structure of the laser device 23 and the branch system 250, or Fig.30 The laser device 24 and the polarization splitting system 251 are configured in this way, and pulse laser light for laser annealing and pulse laser light for ridge flattening are irradiated separately.

[0433] [2] In Embodiment 6, the projection optical system 151 as the mask 149 is used to transfer and image the plurality of pattern regions 149pa to the TFT formation region using one projection optical system 151, but the present invention is not limited to this example. For example, the projection optical system may include a plurality of projection optical systems, and may transfer and image one image to one pattern region, or may include a projection optical system for laser annealing and a projection optical system for ridge flattening.

[0434] 10. Implementation Method 7

[0435] 10.1 Structure

[0436] Fig.35 The structure of the laser annealing system 17 according to the seventh embodiment is schematically shown. Fig.35 structure, for Fig.26 The differences are explained. Fig.35 The laser annealing system 17 shown is Fig.26 The difference between the method and the method is that the projection optical system 150 is not provided. In addition, the irradiation optical system 116 of the laser annealing system 17 is replaced by Fig.26 The illumination optical system 140 and the illumination optical system 340 include the illumination optical system 142 and the illumination optical system 342. Fig.35 The mask 148 shown is arranged close to the surface of the irradiated object 190. The distance between the mask 148 and the irradiated object 190 may be, for example, in the range of 0.2 mm to 0.5 mm.

[0437] The illumination optical system 142 uniformly illuminates the surface of the irradiated object 190 with a line beam via the mask 148. The line beam irradiated to the irradiated object 190 by the illumination optical system 142 is used for laser annealing.

[0438] The illumination optical system 342 uniformly illuminates the surface of the object 190 with a line beam via the mask 148. The line beam irradiated onto the object 190 by the illumination optical system 342 is used for ridge flattening.

[0439] 10.2 Actions

[0440] The pulse laser light for laser annealing and the pulse laser light for ridge flattening pass through the mask 148 disposed close to the irradiated object 190 , and the irradiated object 190 is irradiated with the pulse laser light having a pattern close to the mask pattern.

[0441] 10.3 Effects

[0442] According to the seventh embodiment, the projection optical system can be omitted, and the system configuration can be simplified compared to the third embodiment.

[0443] 10.4 Variations

[0444] [1] In Embodiment 7, a structure using two laser devices, namely, a first laser device 21 and a second laser device 22, is shown. The first laser device 21 outputs a pulse laser with a relatively long pulse time width for laser annealing, and the second laser device 22 outputs a pulse laser with a relatively short pulse time width for ridge flattening. However, the present invention is not limited to this example. For example, it is also possible to replace Fig.35 The first laser device 21 and the second laser device 22 are configured Fig.29 The structure of the laser device 23 and the branch system 250, or Fig.30 The laser device 24 and the polarization splitting system 251 are configured in this way, and pulse laser light for laser annealing and pulse laser light for ridge flattening are irradiated separately.

[0445] 11. Implementation Method 8

[0446] 11.1 Structure

[0447] Fig.36 The structure of the laser annealing system 18 according to the eighth embodiment is schematically shown. Fig.36 The structure shown is Fig.26 The differences are explained.

[0448] Fig.36 The laser annealing system 18 shown replaces Fig.26The irradiation optical system 113 is replaced by the irradiation optical system 117. The irradiation optical system 117 is deleted. Fig.26 The high reflective mirrors 123 and 323, and the illumination optical systems 140 and 340 are replaced by a system 360 including an illumination optical system.

[0449] The illumination optical system 360 includes fly-eye lenses 361 and 362 , high reflection mirrors 365 and 366 , and a condenser lens 368 .

[0450] The fly-eye lens 361 and the high reflection mirror 365 are arranged on the optical path of the pulse laser light for laser annealing. The fly-eye lens 361 is arranged so that the pulse laser light for laser annealing emitted from the high reflection mirror 122 enters the fly-eye lens 361 .

[0451] The fly-eye lens 362 and the high-reflection mirror 366 are arranged on the optical path of the pulsed laser for ridge flattening. The fly-eye lens 362 is arranged so that the pulsed laser for ridge flattening emitted from the high-reflection mirror 322 is incident on the fly-eye lens 362. The high-reflection mirror 366 is arranged so that the central axis of the pulsed laser after passing through the fly-eye lens 362 is vertically incident on the focusing lens 368 as shown in the figure.

[0452] On the other hand, the high reflection mirror 365 disposed on the optical path of the pulse laser for laser annealing is disposed so that the central axis of the pulse laser after passing through the fly-eye lens 361 is incident on the condenser lens 368 at an angle as shown in the figure.

[0453] 11.2 Actions

[0454] By adjusting the reflection angle of the high reflection mirror 365, the position of the line beam LBa for laser annealing irradiated on the surface of the irradiated object 190 can be adjusted. That is, by adjusting the reflection angle of the high reflection mirror 365, the relative positional relationship between the line beam LBa for laser annealing and the line beam LBr for ridge flattening on the surface of the irradiated object 190 can be adjusted.

[0455] The reflection angle of the high reflection mirror 365 is adjusted so that the ridge flattening line beam LBr is arranged near the laser annealing line beam LBa on the surface of the irradiated object 190 .

[0456] 11.3 Effects

[0457] The ridge flattening line beam can be arranged close to the laser annealing line beam by adjusting the angle of the high reflection mirror 365. As a result, the moving distance in the X-axis direction can be shortened, and the productivity is improved.

[0458] 11.4 Variations

[0459] [1] Instead of adjusting the angle of the high reflective mirror 365 , or in addition to adjusting the angle of the high reflective mirror 366 , the arrangement position of the line beam for ridge flattening on the surface of the irradiated object 190 can also be adjusted.

[0460] [2] A tilting rotating stage that tilts and rotates about the Y axis may be installed on the high reflection mirror 365 so that the position of the line beam for laser annealing can be controlled according to the movement direction of the XYZ axis stage 172 in the X axis direction.

[0461] [3] You can also Fig.29 and Fig.30 In this way, a laser device and a branching system or a polarization branching system are configured to irradiate pulsed laser light for laser annealing and for ridge flattening.

[0462] 12. Others

[0463] The technical matters described in the above-mentioned embodiments and modifications may be appropriately combined within a possible range.

[0464] An electronic device including a semiconductor element represented by a TFT can be manufactured using the semiconductor thin film manufactured by the method for manufacturing a semiconductor crystal thin film of the present disclosure.

[0465] The above description is not limiting but simply illustrative. Therefore, those skilled in the art will appreciate that changes can be made to the embodiments of the present disclosure without departing from the claims. In addition, those skilled in the art will appreciate that the embodiments of the present disclosure can be used in combination.

[0466] Unless explicitly stated otherwise, 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 "one" 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 them and parts other than "A", "B" and "C".

Claims

1. A laser annealing system, comprising: a laser system that outputs a first pulse laser having a first pulse time width and a second pulse laser having a second pulse time width that is shorter than the first pulse time width; and A laser annealing device irradiates an object with the first pulse laser and the second pulse laser, The laser annealing device comprises: an irradiation optical system that guides the first pulse laser and the second pulse laser to the irradiated object; a moving mechanism that relatively moves irradiation positions of the first pulse laser and the second pulse laser on the irradiated object; and a control unit that controls the laser system so that the object to be irradiated is irradiated with the first pulse laser, and after the object to be irradiated with the first pulse laser, the region of the object to be irradiated with the first pulse laser is irradiated with the second pulse laser, The laser system comprises: a laser oscillator which outputs a pulsed laser; an optical pulse stretcher for stretching the pulse laser output from the laser oscillator; and a gate, which is arranged on a delayed optical path of the optical pulse stretcher, The control unit controls the output of the first pulse laser and the second pulse laser by controlling the opening and closing of the shutter.

2. The laser annealing system according to claim 1, in, The object to be irradiated with the first pulse laser is an amorphous semiconductor, The control unit controls the laser system and the moving mechanism so that the amorphous semiconductor is polycrystallized by irradiating the amorphous semiconductor with the first pulse laser, and the height of the ridge of the semiconductor crystal is reduced by irradiating the polycrystallized semiconductor crystal region with the second pulse laser.

3. The laser annealing system according to claim 2, in, The first pulse laser beam flux and the first pulse time width are set to conditions that completely melt the amorphous semiconductor. The fluence of the second pulse laser and the second pulse time width are set to conditions under which the ridge portion of the semiconductor crystal generated by the polycrystallization is lowered.

4. A laser annealing system, comprising: a laser system that outputs a first pulse laser having a first pulse time width and a second pulse laser having a second pulse time width that is shorter than the first pulse time width; and A laser annealing device irradiates an object with the first pulse laser and the second pulse laser, The laser annealing device comprises: an irradiation optical system that guides the first pulse laser and the second pulse laser to the irradiated object; a moving mechanism that relatively moves irradiation positions of the first pulse laser and the second pulse laser on the irradiated object; and a control unit that controls the laser system so that the object to be irradiated is irradiated with the first pulse laser, and after the object to be irradiated with the first pulse laser, the region of the object to be irradiated with the first pulse laser is irradiated with the second pulse laser, The laser system comprises: a third laser device that outputs pulsed laser light; an optical pulse stretcher for stretching the pulse laser light output from the third laser device; and a beam splitter arranged on an optical path between the third laser device and the optical pulse stretcher, The laser system outputs the first pulse laser as laser light subjected to pulse stretching by the optical pulse stretcher. The laser system outputs the second pulse laser light as the laser light branched by the beam splitter.

5. The laser annealing system according to claim 4, in, The object to be irradiated with the first pulse laser is an amorphous semiconductor, The control unit controls the laser system and the moving mechanism so that the amorphous semiconductor is polycrystallized by irradiating the amorphous semiconductor with the first pulse laser, and the height of the ridge of the semiconductor crystal is reduced by irradiating the polycrystallized semiconductor crystal region with the second pulse laser.

6. The laser annealing system according to claim 5, in, The first pulse laser beam flux and the first pulse time width are set to conditions that completely melt the amorphous semiconductor. The fluence of the second pulse laser and the second pulse time width are set to conditions under which the ridge portion of the semiconductor crystal generated by the polycrystallization is lowered.

7. The laser annealing system according to claim 4, in, The irradiation optical system includes a mask having a predetermined mask pattern. The object to be irradiated is irradiated with the illumination patterns of the first pulse laser light and the second pulse laser light corresponding to the mask pattern.

8. The laser annealing system according to claim 7, in, The irradiation optical system includes a transfer optical system that transfers the mask pattern of the mask onto the irradiated object as an image.

9. The laser annealing system according to claim 8, in, The transfer optical system is a projection optical system that images the mask pattern on a plurality of regions on the irradiated object where thin film transistors are formed.

10. A laser annealing system, comprising: a laser system that outputs a first pulse laser having a first pulse time width and a second pulse laser having a second pulse time width that is shorter than the first pulse time width; and A laser annealing device irradiates an object with the first pulse laser and the second pulse laser, The laser annealing device comprises: an irradiation optical system that guides the first pulse laser and the second pulse laser to the irradiated object; a moving mechanism that relatively moves irradiation positions of the first pulse laser and the second pulse laser on the irradiated object; and a control unit that controls the laser system so that the object to be irradiated is irradiated with the first pulse laser, and after the object to be irradiated with the first pulse laser, the region of the object to be irradiated with the first pulse laser is irradiated with the second pulse laser, The laser system comprises: a fourth laser device that outputs pulsed laser light; an optical pulse stretcher for stretching the pulse laser light output from the fourth laser device; and a delay device, which is arranged on the optical path between the fourth laser device and the optical pulse stretcher, The laser system outputs the first pulse laser light as laser light of a first polarization component after pulse stretching by the optical pulse stretcher. The laser system outputs the second pulse laser light as laser light of a second polarization component that is not pulse stretched by the optical pulse stretcher.

11. The laser annealing system according to claim 10, in, The object to be irradiated with the first pulse laser is an amorphous semiconductor, The control unit controls the laser system and the moving mechanism so that the amorphous semiconductor is polycrystallized by irradiating the amorphous semiconductor with the first pulse laser, and the height of the ridge of the semiconductor crystal is reduced by irradiating the polycrystallized semiconductor crystal region with the second pulse laser.

12. The laser annealing system according to claim 11, in, The first pulse laser beam flux and the first pulse time width are set to conditions that completely melt the amorphous semiconductor. The fluence of the second pulse laser and the second pulse time width are set to conditions under which the ridge portion of the semiconductor crystal generated by the polycrystallization is lowered.

13. The laser annealing system according to claim 10, in, The irradiation optical system includes a mask having a predetermined mask pattern. The object to be irradiated is irradiated with the illumination patterns of the first pulse laser light and the second pulse laser light corresponding to the mask pattern.

14. The laser annealing system according to claim 13, in, The irradiation optical system includes a transfer optical system that transfers the mask pattern of the mask onto the irradiated object as an image.

15. The laser annealing system according to claim 14, in, The transfer optical system is a projection optical system that images the mask pattern on a plurality of regions on the irradiated object where thin film transistors are formed.

Images