Continuous green laser annealing equipment and annealing method

Abstract

The present invention relates to the field of semiconductor manufacturing technology, and in particular to a continuous green laser annealing device and an annealing method. The continuous green laser annealing device provided in the present application comprises a laser emitting device, a beam expansion device, a focusing spherical mirror, a focusing cylindrical mirror and a moving stage. The distance between the beam expansion device, the focusing spherical mirror and the focusing cylindrical mirror and the focal length of the focusing spherical mirror and the focusing cylindrical mirror are adjusted to adjust the size of the narrow direction of the strip flat-top beam; the annealing time of the laser is controlled by the moving speed of the moving stage and the size of the narrow direction of the strip flat-top beam. The continuous laser annealing time of the continuous green laser annealing device provided in the embodiment of the present application can reach the micron level, and the laser interacts with the amorphous silicon layer to form a polycrystalline silicon layer with large-sized grains, thereby improving the carrier migration rate of the thin film transistor. The annealing method provided by the present invention is based on the above-mentioned continuous green laser annealing device, and therefore also has the above-mentioned technical effects.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor manufacturing technology, and in particular to a continuous green laser annealing device and an annealing method. Background Art

[0002] With the continuous development of semiconductor technology, the high voltage resistance of high-voltage integrated circuits is gradually improving, and at the same time, the requirements for device integration and liquid crystal display technology are getting higher and higher. Low-temperature polysilicon thin-film transistor preparation technology is increasingly used in high-performance active matrix liquid crystal displays and three-dimensional integrated circuits. Annealing is a key step in the transistor manufacturing process. Common annealing methods include furnace annealing, rapid annealing (RTA), laser annealing, etc.

[0003] Since laser annealing heating is limited to the surface layer, it can avoid affecting the front side of the device when high temperature annealing is performed on the back side. The heating during laser annealing is very rapid, and a shorter time will reduce the diffusion effect of the metal, making the alloy surface have lower roughness and higher uniformity. In order to improve the carrier mobility of thin film transistors, various grain enhancement technologies, including solid phase crystallization (SPC), metal induced crystallization (MIC), excimer laser crystallization (ELC), and continuous wave (CW) laser crystallization technology are used in the manufacture of thin film transistors.

[0004] The above-mentioned annealing process has problems such as high operating temperature, metal contamination, small grain size and poor grain uniformity. The continuous wave green laser crystallization technology provided in this application can achieve larger polysilicon grains and a wider laser process window. Summary of the invention

[0005] The present invention provides a continuous green laser annealing device and an annealing method, which can effectively solve the above or other potential technical problems.

[0006] The first aspect of the present invention is to provide a continuous green laser annealing device, including a laser emitting device, a beam expansion device, a focusing spherical mirror, a focusing cylindrical mirror and a moving stage. The laser emitting device is used to emit a continuously adjustable laser; the beam expansion device is used to increase or decrease the beam diameter; the focusing spherical mirror and the focusing cylindrical mirror are used to converge the beam to obtain a rectangular uniform strip flat-top beam with Gaussian characteristics in a narrow direction; the moving stage is used to carry a wafer; the distance between the beam expansion device, the focusing spherical mirror and the focusing cylindrical mirror and the focal length of the focusing spherical mirror and the focusing cylindrical mirror are adjusted to adjust the size of the strip flat-top beam in the narrow direction; the laser annealing time is controlled by the moving speed of the moving stage and the size of the strip flat-top beam in the narrow direction.

[0007] The continuous green laser annealing equipment provided by the present application includes a laser emitting device, a beam expanding device, a focusing spherical mirror, a focusing cylindrical mirror and a movable stage. The laser emitting device is used to emit a continuously adjustable laser; the beam expanding device is used to increase or decrease the diameter of the beam; the focusing spherical mirror and the focusing cylindrical mirror are used to converge the beam to obtain a rectangular uniform strip flat-top beam with Gaussian characteristics in a narrow direction; the movable stage is used to carry a wafer. During use, the distance between the beam expanding device, the focusing spherical mirror and the focusing cylindrical mirror, and the focal length of the focusing spherical mirror and the focusing cylindrical mirror are adjusted to adjust the size of the strip flat-top beam in the narrow direction; the annealing time of the laser is controlled by the moving speed of the movable stage and the size of the strip flat-top beam in the narrow direction. The continuous laser annealing time of the continuous green light laser annealing equipment provided in the embodiment of the present application can reach the micron level. The laser interacts with the amorphous silicon layer, and the resulting temperature rise can make the amorphous silicon layer on the surface of the wafer reach the melting temperature and realize recrystallization during the cooling process, forming a polycrystalline silicon layer with large-sized grains, thereby ultimately improving the carrier migration rate of the thin film transistor.

[0008] In an optional embodiment according to the first aspect, the relationship between the moving speed of the movable stage, the size of the strip flat top beam in the narrow direction and the annealing time satisfies: T=X / V; wherein T is the annealing time; X is the size of the strip flat top beam in the narrow direction; and V is the moving speed of the movable stage.

[0009] In an optional embodiment according to the first aspect, the dimension X of the narrow direction of the strip flat-top beam is 0.03 mm; the moving speed V of the moving stage is 5 mm / s-900 mm / s; and the annealing time T is 30 us-6000 us.

[0010] In an optional embodiment according to the first aspect, the continuous green light laser annealing equipment also includes a laser energy control mirror group; the laser energy control mirror group is arranged close to the beam expander so that the light beam adjusted by the beam expander enters the laser energy control mirror group; the laser energy control mirror group includes a half-wave plate, a polarizer and a rotating mirror frame, and the half-wave plate and the polarizer are both connected to the rotating mirror frame; the half-wave plate is used to rotate the polarization direction of light, and the polarizer is used to select the polarization direction of light transmission, and the rotation angle of the half-wave plate is controlled to make its optical axis deviate from the optical axis of the polarizer to achieve continuous adjustment of light energy.

[0011] In an optional embodiment according to the first aspect, the continuous green light laser annealing equipment also includes a beam propagation device, which includes a first reflector, a second reflector and a third reflector; the first reflector is arranged between the laser emitting device and the beam expanding device, and is used to reflect the horizontal laser emitted by the laser emitting device through the first reflector and enter the beam expanding device in a vertical direction; the second reflector is arranged on a side of the laser energy control mirror group away from the beam expanding device, and is used to reflect the vertical laser emitted by the laser energy control mirror group through the second reflector and emit it in a horizontal direction; the mirror surface of the third reflector is arranged opposite to and parallel to the mirror surface of the second reflector, and is used to reflect the horizontal laser emitted by the second reflector through the third reflector and emit it in a vertical direction, and the light beam passes through the focusing spherical mirror and the focusing cylindrical mirror in sequence, so that the focal position of the light beam is converged on the wafer of the movable stage.

[0012] In an optional embodiment according to the first aspect, the continuous green light laser annealing equipment further includes a light gate; the light gate is disposed between the second reflector and the third reflector, and the light gate is used to control the opening time of the light beam.

[0013] In an optional embodiment according to the first aspect, the first reflector, the second reflector and the third reflector are respectively connected to an angle adjustment frame; the angle adjustment frame is used to adjust the angle of the reflector.

[0014] In an optional embodiment according to the first aspect, the continuous green light laser annealing equipment also includes a DOE shaping lens; the DOE shaping lens is arranged between the focusing spherical mirror and the third reflector; the DOE shaping lens includes a convex and concave unit structure to shape the light beam, and the shaped light beam converges the light beam through the focusing spherical mirror and the focusing cylindrical mirror.

[0015] In an optional embodiment according to the first aspect, the continuous green light laser annealing equipment further includes an aperture and a two-dimensional adjustment frame, wherein the aperture is used for edge filtering of the light beam, and the aperture and the DOE shaping lens are both mounted on the two-dimensional adjustment frame.

[0016] The second aspect of the present invention further provides an annealing method, based on the above-mentioned continuous green laser annealing device, comprising:

[0017] Controlling the laser emitting device to emit a laser beam with a preset energy, and irradiating the laser beam onto the amorphous silicon layer on the movable stage through transmission and shaping;

[0018] The movable stage is controlled to run at a preset speed, the laser beam is irradiated on the amorphous silicon layer, and the amorphous silicon layer is formed into a polycrystalline silicon layer.

[0019] The continuous green light laser annealing equipment and annealing method provided by the present invention are based on the above-mentioned continuous green light laser annealing equipment, and therefore also have the above-mentioned continuous laser annealing time that can reach the micron level. The laser interacts with the amorphous silicon layer, and the resulting temperature rise can make the amorphous silicon layer on the surface of the wafer reach the melting temperature and realize recrystallization during the cooling process, which can form a polycrystalline silicon layer with large-sized grains, and ultimately improve the carrier migration rate of the thin film transistor.

[0020] Advantages of additional aspects of the present invention will be given in part in the following description, and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The above and other objects, features and advantages of the embodiments of the present invention will become more easily understood through the following detailed description with reference to the accompanying drawings, in which several embodiments of the present invention will be described by way of example and not limitation, wherein:

[0022] Figure 1 A schematic diagram of the structure of a laser emitting device, a beam expanding device, a laser energy control mirror group, a beam propagation device and an optical gate of a continuous green laser annealing device provided in an embodiment of the present invention;

[0023] Figure 2 A schematic diagram of the structure of a focusing spherical mirror, a focusing cylindrical mirror, a moving stage, a DOE shaping lens and an aperture of a continuous green laser annealing device provided in an embodiment of the present invention;

[0024] Figure 3 A schematic diagram of the annealing process of a laser on a wafer using a continuous green laser annealing device provided in an embodiment of the present invention;

[0025] Figure 4 A schematic diagram of the working of the focusing spherical mirror and the focusing cylindrical mirror of the continuous green light laser annealing equipment provided in an embodiment of the present invention.

[0026] Description of reference numerals:

[0027] 100. Continuous green laser annealing equipment; 11. Laser emitting device; 12. Beam expanding device; 13. Focusing spherical mirror; 14. Focusing cylindrical mirror; 15. Moving stage; 16. Laser energy control mirror group; 161. Half-wave plate; 162. Polarizer; 163. Rotating mirror frame; 17. Beam propagation device; 171. First reflector; 172. Second reflector; 173. Third reflector; 18. Optical shutter; 19. DOE shaping lens; 20. Aperture; 21. Wafer; 22. Strip flat-top beam. DETAILED DESCRIPTION

[0028] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0029] It should be understood that the following embodiments do not limit the execution order of the steps in the method protected by the present invention. The steps of the method of the present invention can be executed in any possible order and in a cyclic manner without being contradictory.

[0030] In the description of the present invention, it is necessary to understand that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0031] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0032] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0034] With the continuous development of semiconductor technology, the high voltage resistance of high-voltage integrated circuits is gradually improving, and the requirements for device integration and liquid crystal display technology are getting higher and higher. Low-temperature polysilicon thin-film transistor preparation technology is increasingly used in high-performance active matrix liquid crystal displays and three-dimensional integrated circuits. Annealing is a key step in the transistor manufacturing process. Common annealing methods include furnace annealing, rapid annealing (RTA), laser annealing, etc. Since laser annealing heating is limited to the surface layer, it can avoid the impact on the front of the device when high-temperature annealing is performed on the back. The heating during laser annealing is very rapid, and a shorter time will reduce the diffusion effect of the metal, making the alloy surface have lower roughness and higher uniformity. In order to improve the carrier mobility of thin-film transistors, various grain enhancement technologies, including solid phase crystallization (SPC), metal induced crystallization (MIC), excimer laser crystallization (ELC), and continuous wave (CW) laser crystallization technology are used in the manufacture of thin-film transistors. The above-mentioned annealing process has problems such as high operating temperature, metal contamination, small grain size and poor grain uniformity. The continuous wave green laser crystallization technology provided in this application can achieve larger polysilicon grains and a wider laser process window.

[0035] In view of this, the continuous green laser annealing equipment provided by the present application includes a laser emitting device, a beam expanding device, a focusing spherical mirror, a focusing cylindrical mirror and a movable stage. The laser emitting device is used to emit a continuously adjustable laser; the beam expanding device is used to increase or decrease the diameter of the beam; the focusing spherical mirror and the focusing cylindrical mirror are used to converge the beam to obtain a rectangular uniform strip flat-top beam with Gaussian characteristics in a narrow direction; the movable stage is used to carry the wafer. During use, the distance between the beam expanding device, the focusing spherical mirror and the focusing cylindrical mirror, and the focal length of the focusing spherical mirror and the focusing cylindrical mirror are adjusted to adjust the size of the strip flat-top beam in the narrow direction; the annealing time of the laser is controlled by the moving speed of the movable stage and the size of the strip flat-top beam in the narrow direction. The continuous laser annealing time of the continuous green light laser annealing equipment provided in the embodiment of the present application can reach the micron level. The laser interacts with the amorphous silicon layer, and the resulting temperature rise can make the amorphous silicon layer on the surface of the wafer reach the melting temperature and realize recrystallization during the cooling process, forming a polycrystalline silicon layer with large-sized grains, thereby ultimately improving the carrier migration rate of the thin film transistor.

[0036] Please refer to Figures 1 to 4 The continuous green laser annealing device 100 provided in the embodiment of the present invention comprises a laser emitting device 11, a beam expanding device 12, a focusing spherical mirror 13, a focusing cylindrical mirror 14 and a moving stage 15. The laser emitting device 11 is used to emit a continuously adjustable laser; the beam expanding device 12 is used to increase or decrease the beam diameter; the focusing spherical mirror 13 and the focusing cylindrical mirror 14 are used to converge the beam to obtain a rectangular uniform strip flat top beam 22 with Gaussian characteristics in a narrow direction; the moving stage 15 is used to carry a wafer 21; the distance between the beam expanding device 12, the focusing spherical mirror 13 and the focusing cylindrical mirror 14 and the focal length of the focusing spherical mirror 13 and the focusing cylindrical mirror 14 are adjusted to adjust the size of the strip flat top beam 22 in the narrow direction; the laser annealing time is controlled by the moving speed of the moving stage 15 and the size of the strip flat top beam 22 in the narrow direction.

[0037] The continuous laser annealing time of the continuous green light laser annealing device 100 provided in the embodiment of the present application can reach the micron level. The laser interacts with the amorphous silicon layer, and the resulting temperature rise can make the amorphous silicon layer on the surface of the wafer 21 reach the melting temperature and realize recrystallization during the cooling process, thereby forming a polycrystalline silicon layer with large-sized grains, and ultimately improving the carrier migration rate of the thin film transistor.

[0038] In an optional exemplary embodiment, the relationship between the moving speed of the movable stage 15, the size of the strip flat top beam 22 in the narrow direction and the annealing time satisfies: T=X / V; wherein T is the annealing time; X is the size of the strip flat top beam 22 in the narrow direction; and V is the moving speed of the movable stage 15.

[0039] It should be noted that, specifically, in the present embodiment, by controlling the size of the narrow direction of the strip flat-top beam 22 and the moving speed of the movable stage 15, the annealing time of the laser can be controlled so that the annealing time can reach the micron level. The laser interacts with the amorphous silicon layer, and the resulting temperature rise can make the amorphous silicon layer on the surface of the wafer 21 reach the melting temperature and realize recrystallization during the cooling process, thereby forming a polycrystalline silicon layer with large-sized grains, thereby ultimately improving the carrier migration rate of the thin film transistor.

[0040] Exemplarily, in this embodiment, the dimension X of the narrow direction of the strip flat-top beam 22 is 0.03 mm; the moving speed V of the moving stage 15 is 5 mm / s-900 mm / s; and the annealing time T is 30 us-6000 us.

[0041] It should be noted that, by using the above data, the annealing time T can be 30us-6000us. That is, it can reach the micron level, so that the laser interacts with the amorphous silicon layer, and the resulting temperature rise can make the amorphous silicon layer on the surface of the wafer 21 reach the melting temperature and realize recrystallization during the cooling process, forming a polycrystalline silicon layer with large-sized grains, and finally improving the carrier migration rate of the thin film transistor.

[0042] In an optional exemplary embodiment, the continuous green light laser annealing equipment 100 also includes a laser energy control mirror group 16; the laser energy control mirror group 16 is arranged close to the beam expander 12 so that the light beam adjusted by the beam expander 12 enters the laser energy control mirror group 16; the laser energy control mirror group 16 includes a half-wave plate 161, a polarizer 162 and a rotating mirror frame 163, and the half-wave plate 161 and the polarizer 162 are both connected to the rotating mirror frame 163; the half-wave plate 161 is used to rotate the polarization direction of the light, and the polarizer 162 is used to select the polarization direction of the light transmission, and the rotation angle of the half-wave plate 161 is controlled to make its optical axis deviate from the optical axis of the polarizer 162 so as to continuously adjust the light energy.

[0043] It should be noted that, specifically, in this embodiment, a laser energy control mirror group 16 is provided so that the light beam adjusted by the beam expansion device 12 enters the laser energy control mirror group 16. Specifically, the laser energy control mirror group 16 includes a half-wave plate 161, a polarizing plate 162, and a rotating mirror frame 163, and the half-wave plate 161 and the polarizing plate 162 are both connected to the rotating mirror frame 163; the half-wave plate 161 is used to rotate the polarization direction of the light, and the polarizing plate 162 is used to select the polarization direction of the light transmission, and the rotation angle of the half-wave plate 161 is controlled to make the optical axis deviate from the optical axis of the polarizing plate 162 so as to continuously adjust the light energy.

[0044] Exemplarily, the rotating mirror frame 163 is an electric knob frame to assist in achieving energy control of the laser.

[0045] Exemplarily, in this embodiment, the rotation angle period of the half-wave plate 161 is 45°.

[0046] In an optional exemplary embodiment, the continuous green laser annealing device 100 further includes a beam propagation device 17, which includes a first reflector 171, a second reflector 172, and a third reflector 173. The first reflector 171 is disposed between the laser emitting device 11 and the beam expanding device 12, and is used to reflect the horizontal laser emitted by the laser emitting device 11 through the first reflector 171 and enter the beam expanding device 12 in a vertical direction. The second reflector 172 is disposed on a side of the laser energy control mirror group 16 away from the beam expanding device 12, and is used to reflect the vertical laser emitted by the laser energy control mirror group 16 through the second reflector 172 and emit it in a horizontal direction. The mirror surface of the third reflector 173 is arranged opposite to and parallel to the mirror surface of the second reflector 172, and is used to reflect the horizontal laser emitted by the second reflector 172 through the third reflector 173 and then emit it in a vertical direction. The light beam passes through the focusing spherical mirror 13 and the focusing cylindrical mirror 14 in sequence, so that the focal position of the light beam is converged on the wafer 21 of the movable stage 15.

[0047] It should be noted that, specifically, in this embodiment, three reflectors are provided to change the propagation direction of the laser, so that the laser emitted by the laser emitting device 11 can converge the focal position of the light beam onto the wafer 21 on the movable stage 15 .

[0048] Exemplarily, in this embodiment, the first reflector 171, the second reflector 172 and the third reflector 173 are all configured as 45° fully reflective mirrors to change the beam path and reduce the space occupied by the device.

[0049] In an optional exemplary embodiment, the continuous green laser annealing device 100 further includes a shutter 18 ; the shutter 18 is disposed between the second reflector 172 and the third reflector 173 , and the shutter 18 is used to control the opening time of the light beam.

[0050] It should be noted that, specifically, in this embodiment, the continuous green laser annealing equipment 100 further includes an optical shutter 18; the optical shutter 18 is used to control the opening time of the light beam.

[0051] For example, the shutter 18 is mounted on a rotating drive motor, and a total reflection lens is mounted on the shutter 18, and the laser passing through the total reflection mirror is collected into the light trap. The opening time of the shutter 18 and a certain time switch delay are controlled by the drive motor to coordinate the laser beam irradiating the surface of the wafer 21, and the laser annealing of different areas is realized in combination with the movable stage.

[0052] Specifically, the system annealing software of the equipment controls the parameters of the laser light emission to achieve different output powers. At the same time, the control software controls the movement trajectory of the mobile stage 15 in the X and Y axis directions and the switching time of the light gate 18 to realize the annealing process of the wafer 21. The annealing temperature of the surface of the wafer 21 is mainly determined by the power density of the irradiated laser and the annealing time. The continuous laser annealing time is mainly determined by the movement speed of the mobile stage 15 and the size of the narrow direction of the light spot.

[0053] In an optional exemplary embodiment, the first reflector 171, the second reflector 172 and the third reflector 173 are each connected to an angle adjustment frame; the angle adjustment frame is used to adjust the angle of the reflector.

[0054] It should be noted that, specifically, in this embodiment, the first reflector 171, the second reflector 172 and the third reflector 173 are respectively connected to an angle adjustment frame; the angle adjustment frame is used to adjust the angle of the reflector, and then adjust it to a preset angle, so that the laser emitted by the laser emitting device 11 can converge the focal position of the light beam on the wafer 21 of the movable carrier 15.

[0055] Exemplarily, the angle adjustment frame is installed on a planar two-dimensional adjustment table, and then cooperates with the angle adjustment frame to achieve different transmission paths of the laser by changing the emission angle of the incident laser.

[0056] In an optional exemplary embodiment, the continuous green light laser annealing equipment 100 also includes a DOE shaping lens 19; the DOE shaping lens 19 is arranged between the focusing spherical mirror 13 and the third reflector 173; the DOE shaping lens 19 includes a convex and concave unit structure to shape the light beam, and the shaped light beam converges the light beam through the focusing spherical mirror 13 and the focusing cylindrical mirror 14.

[0057] It should be noted that, specifically, in this embodiment, DOE (Diffractive Optical Elements). The DOE shaping lens 19 is arranged between the focusing spherical mirror 13 and the third reflector 173 to shape the light beam. The shaped light beam converges the light beam through the focusing spherical mirror 13 and the focusing cylindrical mirror 14. Due to the different designs and Wiener etching processes, the DOE shaping lens 19 has different raised and recessed unit structures. After the light passes through the unit structure, a phase difference will occur due to the distance and the refractive index of the material. At the same time, the light passing through will be diffracted and will interfere at a specific distance position to form a specific light intensity distribution, thereby realizing beam shaping. The DOE shaping lens 19 is a stepped one-dimensional diffraction shaping lens, which homogenizes the internal energy of the passing Gaussian beam to form an internally homogenized flat-top beam consistent with the step pattern of the DOE shaping lens 19, and the edge of the light spot still has Gaussian characteristics. Specifically, the light beam after DOE shaping needs to be converged using a focusing spherical mirror 13 and the focusing cylindrical mirror 14 to obtain a rectangular uniform strip flat-top light beam 22 that maintains Gaussian characteristics in a narrow direction.

[0058] In an optional exemplary embodiment, the continuous green laser annealing device 100 further includes an aperture 20 and a two-dimensional adjustment frame, wherein the aperture 20 is used for edge filtering of the light beam, and the aperture 20 and the DOE shaping lens 19 are both mounted on the two-dimensional adjustment frame.

[0059] It should be noted that, specifically, in this embodiment, the aperture 20 is used to implement edge filtering of the light beam. The aperture 20 and the DOE shaping lens 19 are both mounted on the two-dimensional adjustment frame, which is used to adjust the aperture 20 and the DOE shaping lens 19 to move up and down along the vertical direction, thereby moving away from or close to the wafer 21 of the movable stage 15.

[0060] The present invention also provides an annealing method, based on the above-mentioned continuous green laser annealing device 100, comprising:

[0061] Controlling the laser emitting device 11 to emit a laser beam with a preset energy, and irradiating the laser beam onto the amorphous silicon layer on the movable stage 15 through transmission and shaping;

[0062] The movable stage is controlled to run at a preset speed, the laser beam is irradiated on the amorphous silicon layer, and the amorphous silicon layer is formed into a polycrystalline silicon layer.

[0063] The annealing method provided by the present invention is based on the above-mentioned continuous green light laser annealing device 100, and therefore also has the above-mentioned continuous laser annealing time that can reach the micron level. The laser interacts with the amorphous silicon layer, and the resulting temperature rise can make the amorphous silicon layer on the surface of the wafer 21 reach the melting temperature and realize recrystallization during the cooling process, and a polycrystalline silicon layer with large-sized grains can be formed, ultimately improving the technical effect of the carrier migration rate of the thin film transistor.

[0064] Finally, it should be noted that the above implementation modes are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned implementation modes, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned implementation modes, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the implementation modes of the present invention.

[0065] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

Claims

1. A continuous green laser annealing device, characterized in that: It includes a laser emitting device, a beam expanding device, a focusing spherical mirror, a focusing cylindrical mirror and a moving stage; The laser emitting device is used to emit continuously adjustable laser; The beam expansion device is used to increase or decrease the diameter of the beam; The focusing spherical mirror and the focusing cylindrical mirror are used to converge the light beam to obtain a strip-shaped flat-top light beam that is rectangular and uniform and maintains Gaussian characteristics in a narrow direction; The movable stage is used for carrying the wafer; Adjusting the distance between the beam expander, the focusing spherical mirror and the focusing cylindrical mirror, and the focal lengths of the focusing spherical mirror and the focusing cylindrical mirror to adjust the size of the strip-shaped flat-top beam in the narrow direction; The laser annealing time is controlled by the moving speed of the moving stage and the size of the strip flat top beam in the narrow direction.

2. The continuous green laser annealing equipment according to claim 1, characterized in that: The relationship between the moving speed of the movable stage, the narrow dimension of the strip flat top beam and the annealing time satisfies: T=X / V; wherein T is the annealing time; X is the narrow dimension of the strip flat top beam; and V is the moving speed of the movable stage.

3. The continuous green laser annealing equipment according to claim 2, characterized in that: The dimension X of the narrow direction of the strip flat-top beam is 0.03 mm; the moving speed V of the moving stage is 5 mm / s-900 mm / s; and the annealing time T is 30 us-6000 us.

4. The continuous green laser annealing device according to claim 1, characterized in that: It also includes a laser energy control mirror group; the laser energy control mirror group is arranged close to the beam expander so that the light beam adjusted by the beam expander enters the laser energy control mirror group; The laser energy control mirror group includes a half-wave plate, a polarizing plate and a rotating mirror frame, and the half-wave plate and the polarizing plate are both connected to the rotating mirror frame; The half-wave plate is used to rotate the polarization direction of light, and the polarizer is used to select the polarization direction of light transmission. By controlling the rotation angle of the half-wave plate, its optical axis deviates from the optical axis of the polarizer so as to continuously adjust the light energy.

5. The continuous green laser annealing equipment according to claim 4, characterized in that: Also included is a beam propagation device, the beam propagation device comprising a first reflector, a second reflector, and a third reflector; The first reflector is disposed between the laser emitting device and the beam expander, and is used to reflect the horizontal laser emitted by the laser emitting device through the first reflector and enter the beam expander in a vertical direction; The second reflector is disposed on a side of the laser energy control mirror group away from the beam expansion device, and is used to reflect the vertical laser emitted by the laser energy control mirror group through the second reflector and then emit it in a horizontal direction; The mirror surface of the third reflector is arranged opposite to and parallel to the mirror surface of the second reflector, and is used to reflect the horizontal laser emitted by the second reflector through the third reflector and then emit it in a vertical direction. The light beam passes through the focusing spherical mirror and the focusing cylindrical mirror in sequence, so that the focal position of the light beam is converged on the wafer on the movable stage.

6. The continuous green laser annealing device according to claim 5, characterized in that: It also includes a light gate; the light gate is arranged between the second reflector and the third reflector, and the light gate is used to control the opening time of the light beam.

7. The continuous green laser annealing device according to claim 5, characterized in that: The first reflector, the second reflector and the third reflector are respectively connected to an angle adjustment frame; the angle adjustment frame is used to adjust the angle of the reflector.

8. The continuous green laser annealing device according to claim 5, characterized in that: It also includes a DOE shaping lens; the DOE shaping lens is arranged between the focusing spherical mirror and the third reflecting mirror; the DOE shaping lens includes a convex and concave unit structure to shape the light beam, and the shaped light beam is converged by the focusing spherical mirror and the focusing cylindrical mirror.

9. The continuous green laser annealing device according to claim 8, characterized in that: It also includes an aperture and a two-dimensional adjustment frame. The aperture is used for edge filtering of the light beam. The aperture and the DOE shaping lens are both installed on the two-dimensional adjustment frame.

10. An annealing method, characterized in that: The continuous green laser annealing device according to any one of claims 1 to 9 comprises: Controlling the laser emitting device to emit a laser beam with a preset energy, and irradiating the laser beam onto the amorphous silicon layer on the movable stage through transmission and shaping; The movable stage is controlled to run at a preset speed, the laser beam is irradiated on the amorphous silicon layer, and the amorphous silicon layer is formed into a polycrystalline silicon layer.

Images