An excimer laser annealing device and a method for preparing a polysilicon thin film
By optimizing the laser scanning path through tilted vector direction scanning and slit assembly adjustment, the problem of low substrate utilization was solved, resulting in a larger effective laser scanning area and higher substrate utilization.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- BOE TECHNOLOGY GROUP CO LTD
- Filing Date
- 2024-09-29
- Publication Date
- 2026-06-26
AI Technical Summary
In existing excimer laser annealing processes, the effective area covered by the laser irradiation on the substrate is small, resulting in low substrate utilization.
The laser scanning path is optimized by using a tilted vector direction scanning method, and the blocking range of the laser beam is adjusted by combining a slit component to ensure that the laser beam only illuminates the effective area of the substrate and avoids illuminating the surface of the substrate stage.
It increases the area of the effective laser scanning region, improves substrate utilization, reduces the risk of damage to the substrate stage, and enhances the crystallization effect.
Smart Images
Figure CN119300689B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of display technology, and in particular to an excimer laser annealing apparatus and a method for preparing polycrystalline silicon thin films. Background Technology
[0002] In the backplane technology of OLED (Organic Light Emitting Diode), the polycrystalline silicon layer is mainly fabricated using various methods such as excimer laser annealing (ELA), solid-state crystallization, or metal-induced crystallization.
[0003] Using excimer laser annealing to obtain polycrystalline silicon thin films for the active transistor layer in a backplane is a method that can be mass-produced. Excimer laser annealing is a relatively complex annealing process.
[0004] Excimer laser annealing equipment uses an excimer laser beam to irradiate an amorphous silicon film on a substrate for a short period of time, causing it to recrystallize into a polycrystalline silicon film. In actual processing, it has been found that the excimer laser annealing process suffers from low substrate utilization due to the small effective scanning area of the laser irradiation on the substrate. Summary of the Invention
[0005] This disclosure provides an excimer laser annealing apparatus and a method for preparing polycrystalline silicon thin films, which can improve substrate utilization.
[0006] The technical solutions provided in this disclosure are as follows:
[0007] In a first aspect, embodiments of this disclosure provide an excimer laser annealing apparatus, comprising:
[0008] A substrate stage for holding the substrate to be processed; and
[0009] A laser unit is provided, wherein the laser unit is used to emit a laser beam onto the bearing surface of the substrate stage, and the laser beam has an extension length along a first direction, the first direction being parallel to the substrate to be processed; wherein,
[0010] The substrate to be processed includes a first side and a second side disposed adjacent to each other, and the substrate to be processed is disposed on the substrate stage with the first side inclined relative to a reference direction. The reference direction is perpendicular to the first direction and the plane defined by the first direction is parallel to the substrate to be processed. The substrate stage is capable of moving relative to the laser beam along a second direction, which is a vector direction that is inclined relative to both the first direction and the reference direction.
[0011] For example, the tilt angle of the first side relative to the reference direction is a first angle α, and the tilt angle of the second direction relative to the reference direction is a second angle β, where α≥β≥-α.
[0012] For example, α = β.
[0013] For example, the laser unit includes:
[0014] A laser generator is used to emit a laser beam;
[0015] A beam modulator, disposed on the side of the laser generator near the substrate stage and located in the optical path of the laser beam, is used to modulate the laser beam into a predetermined shape having a predetermined length along the first direction; and
[0016] A slit assembly is disposed in the optical path of the laser beam and located on the side of the beam modulator away from the laser generator. The slit assembly has a slit through which the laser beam can pass, and a first shielding member and a second shielding member that enclose the slit. The slit extends in a direction parallel to the second side, and the width of the slit in a direction perpendicular to its own extension direction is adjustable.
[0017] For example, the slit assembly further includes:
[0018] The first movable member is connected to the first blocking member;
[0019] The second movable member is connected to the second blocking member; wherein...
[0020] The first blocking member and the second blocking member are disposed opposite to each other in the second direction, and the gap between the first blocking member and the second blocking member forms the slit; the first movable member and the second movable member can move towards or away from each other along the reference direction or the second direction to adjust the width of the slit in the direction perpendicular to its extension.
[0021] For example, the slit assembly further includes:
[0022] The first adjusting member is connected between the first movable member and the first blocking member;
[0023] The second adjusting member is connected between the second movable member and the second blocking member; wherein...
[0024] The first adjusting member is movable relative to the first movable member, and causes the tilt angle of the first blocking member relative to the second direction to change; and the second adjusting member is movable relative to the second movable member, and causes the tilt angle of the second blocking member relative to the second direction to change, so that the extension direction of the slit is adjustable.
[0025] For example, the first adjusting member includes a first connecting end connected to the first movable member and a second connecting end connected to the first blocking member, wherein the first connecting end is pivotally connected to the first movable member, and the second connecting end is rotatable about the pivot point to drive the tilt angle of the first blocking member relative to the second direction to change.
[0026] The second adjusting member includes a third connecting end connected to the second movable member and a fourth connecting end connected to the second blocking member, wherein the third connecting end is pivotally connected to the second movable member, and the fourth connecting end is rotatable about the pivot point to drive the second blocking member to change the tilt angle relative to the second direction.
[0027] Secondly, this disclosure also provides a method for preparing a polycrystalline silicon thin film, comprising the following steps:
[0028] An amorphous silicon thin film is formed on the substrate of the substrate to be processed;
[0029] The amorphous silicon thin film of the substrate to be processed is annealed using the excimer laser annealing apparatus described above.
[0030] For example, the annealing of the amorphous silicon thin film of the substrate to be treated using the excimer laser annealing apparatus described above specifically includes:
[0031] The substrate to be processed is placed on the substrate carrier with the first side inclined relative to the reference direction;
[0032] The laser unit emits a laser beam, and the substrate stage is controlled to move relative to the laser beam along a second direction to perform laser scanning on the amorphous silicon thin film on the substrate to be processed.
[0033] For example, in the method, a laser beam is emitted by the laser unit, and the substrate stage is controlled to move relative to the laser beam along a second direction to perform laser scanning on the amorphous silicon thin film on the substrate to be processed, specifically including:
[0034] The slit of the slit assembly is arranged to extend parallel to the second side, and the first shield and the second shield are arranged along the direction from the laser scanning start end to the laser scanning end end.
[0035] At the beginning of the laser scanning phase, the slit is adjusted to a first width, which is configured to allow only a portion of the laser beam to pass through the slit and be directed toward the substrate to be processed, while the other portion of the laser beam is blocked by the first shielding member.
[0036] During the intermediate stage of laser scanning, the slit is adjusted to a second width, which is configured to allow the laser beam to pass entirely through the slit and be directed toward the substrate to be processed.
[0037] During the laser scanning termination phase, the slit is adjusted to a third width, which is configured to allow only a portion of the laser beam to pass through the slit and be directed toward the substrate to be processed, while the other portion of the laser beam is blocked by the second shielding member.
[0038] For example, in the method, a laser beam is emitted by the laser unit, and the substrate stage is controlled to move relative to the laser beam along a second direction to perform laser scanning on the amorphous silicon thin film on the substrate to be processed. Specifically, the method further includes:
[0039] Let the total time of the laser scanning process be T, the moving speed of the substrate to be processed be v, and take the time when the substrate to be processed starts moving as 0 as the reference. Let the duration of the initial stage of the laser scanning be t1, the duration of the middle stage of the laser scanning be t2, and the duration of the final stage of the laser scanning be t3. Let t1 = b*tanα / v, t3 = b*tanα / v, and t2 = T - t1 - t2, where b is the length of the first side and α is the tilt angle of the second side relative to the reference direction.
[0040] The beneficial effects of the embodiments disclosed herein are as follows:
[0041] In the above solution, the laser scanning path of the substrate to be processed is optimized. The scanning is changed from the reference direction that is perpendicular to the extension length of the laser beam in the related technology to a vector direction scanning that is tilted relative to the reference direction (i.e. the aforementioned reference direction). This makes the substrate to be processed not only displaced in the reference direction, but also displaced in the direction parallel to the extension length of the laser beam during the laser scanning process. This can increase the area of the substrate that is laser scanned in the reference direction, thereby effectively increasing the area of the effective laser scanning area and improving the substrate utilization rate. Attached Figure Description
[0042] Figure 1 A schematic diagram illustrating the effective area of laser scanning when the substrate to be processed moves along a reference direction in a related technology;
[0043] Figure 2 This is a schematic diagram showing the effective area of laser scanning when the substrate to be processed moves along the second direction in an embodiment of this disclosure;
[0044] Figure 3 This diagram illustrates the structure of the excimer laser annealing apparatus provided in the embodiments of this disclosure, wherein only the first and second light-shielding components are shown in the slit assembly.
[0045] Figure 4 This is a schematic diagram of the slit assembly in the excimer laser annealing apparatus provided in the embodiments of this disclosure;
[0046] Figure 5 This diagram illustrates the excimer laser annealing apparatus provided in the embodiments of this disclosure during the initial stage of laser scanning.
[0047] Figure 6 This is a schematic diagram illustrating the transition of the excimer laser annealing apparatus provided in the embodiments of this disclosure from the initial stage of laser scanning to the intermediate stage of laser scanning.
[0048] Figure 7 This diagram illustrates the excimer laser annealing apparatus provided in this embodiment during the transition phase of laser scanning.
[0049] Figure 8 One of the schematic diagrams showing the excimer laser annealing apparatus provided in the embodiments of this disclosure during the transition from the intermediate stage of laser scanning to the termination stage of laser scanning;
[0050] Figure 9 This is the second schematic diagram illustrating the transition of the excimer laser annealing apparatus provided in this embodiment from the intermediate stage of laser scanning to the final stage of laser scanning. Detailed Implementation
[0051] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.
[0052] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an,” “a,” or “the,” and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms “including,” “comprising,” or “containing,” and similar terms mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. The terms “connected,” “linked,” or similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms “upper,” “lower,” “left,” and “right,” etc., are used only to indicate relative positional relationships, and these relative positional relationships may change accordingly when the absolute position of the described objects changes.
[0053] The features such as "parallel," "perpendicular," and "identical" used in the embodiments of this disclosure include features in the strict sense of "parallel," "perpendicular," and "identical," as well as cases where "approximately parallel," "approximately perpendicular," and "approximately identical" include certain tolerances. Taking into account the measurement and the tolerances associated with the measurement of a specific quantity (e.g., limitations of the measurement system), they represent the acceptable deviation range for a specific value as determined by a person skilled in the art. For example, "approximately" can mean within one or more standard deviations, or within 3% or 5% of said value.
[0054] Furthermore, throughout this document, unless otherwise defined, the terms “substantially,” “essentially,” “approximately,” and “about” are used to describe and explain small variations. When used with an event or situation, these terms can cover situations where the event or situation occurs precisely or approximately. For example, when used with a numerical value, these terms can include a range of variation of the numerical value less than or equal to 10%, such as less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, or less than or equal to ±0.05%. The term “substantially coplanar” can refer to two surfaces arranged along the same plane within a micrometer range, for example, within 40 μm, 30 μm, 20 μm, 10 μm, or 1 μm.
[0055] It should be understood that, in the exemplary embodiments of this disclosure, when a layer or element is referred to as being on another layer or substrate, it may mean that the layer or element is directly on the other layer or substrate, or that there is an intermediate layer between the layer or element and the other layer or substrate. "A and B are set in the same layer" means that after A and B are formed using the same film deposition process to form a film layer for forming a specific pattern, the layer structure is formed in one patterning process using the same photomask.
[0056] Excimer laser annealing (ELA) is a technique that uses excimer lasers to anneal materials, and it is widely used in semiconductor manufacturing and thin film technology. This technique is primarily used to improve the crystallinity of thin film materials, enhance their electrical properties, and improve their mechanical properties.
[0057] An excimer laser is a short-wavelength laser, typically in the ultraviolet spectral range (e.g., 193 nm or 248 nm). During annealing, the laser pulse irradiates the material surface, instantly heating it to a molten or near-molten state. Due to the extremely short pulse duration (typically on the nanosecond scale), the material cools rapidly after laser irradiation, forming a new crystal structure. This rapid heating and cooling process helps eliminate defects in the material and improves its crystallinity.
[0058] In the manufacturing process of OLED (Organic Light Emitting Diode), the excimer laser annealing (ELA) process is used to irradiate the surface of the substrate to be processed with a laser, causing amorphous silicon (A-Si) to melt and recrystallize into polycrystalline silicon (P-Si).
[0059] However, the excimer laser annealing process in related technologies suffers from the problem that the area covered by the laser irradiation on the substrate is small, resulting in a small crystallization area and low substrate utilization.
[0060] The inventors of this application have discovered through research that one of the reasons for the above-mentioned problems is:
[0061] In related technologies, laser scanning generally employs an oblique scanning method. Specifically, with the laser scanning direction as the reference direction, a substrate stage carries the substrate to be processed, both of which are tilted at a certain angle (e.g., 1°, 3°, 5°, etc.) relative to this reference direction. The laser beam extends a specific width in the perpendicular reference direction, and the substrate stage moves relative to the laser beam along the reference direction so that the laser beam scans the surface of the substrate to be processed. Because the substrate to be processed is tilted at a certain angle relative to the scanning direction, and the laser beam extends a predetermined length in the perpendicular scanning direction, a portion of the substrate to be processed will not be irradiated by the laser.
[0062] To reduce static electricity and impurities, materials such as aluminum are typically used for the substrate stage. If the laser shines on the surface of the substrate stage, it will damage the stage and also affect the crystallization effect. Therefore, during laser scanning, it is best to avoid laser irradiation on the substrate stage surface other than the substrate being processed.
[0063] In related technologies, to minimize the amount of laser light irradiating the substrate stage surface, the laser beam length is shortened during tilt scanning, or the laser scanning start position is moved as far inward as possible (i.e., close to the center of the substrate to be processed). This results in a smaller effective scanning area, fewer crystalline regions, and low substrate utilization.
[0064] To address the aforementioned issues, this disclosure provides an excimer laser annealing apparatus and a method for preparing polycrystalline silicon thin films, which can improve substrate utilization.
[0065] like Figure 2 As shown, this disclosure provides an excimer laser annealing apparatus, comprising:
[0066] Substrate stage 100, used to support substrate 200 to be processed; and
[0067] A laser unit 300 is provided, which emits a laser beam B onto the bearing surface of the substrate stage 100, and the laser beam B has an extension length along a first direction X, which is parallel to the substrate 200 to be processed; wherein,
[0068] The substrate to be processed 200 includes a first side 210 and a second side 220 disposed adjacently, and the substrate to be processed 200 is disposed on the substrate stage 100 with the first side 210 inclined relative to the reference direction Y. The reference direction Y is perpendicular to the first direction X and the plane defined by the first direction X is parallel to the substrate to be processed 200. The substrate stage 100 is movable relative to the laser beam B along a second direction R, and the second direction R is a vector direction that is inclined relative to both the first direction X and the reference direction Y.
[0069] In the above scheme, the extension length direction of the laser beam B (i.e., the first direction X) is taken as the X-axis direction, and the reference direction Y perpendicular to the first direction X is taken as the Y-axis direction. The substrate 200 to be processed moves relative to the laser beam B along the second direction R which is inclined relative to both the X-axis and the Y-axis. This optimizes the laser scanning path of the substrate 200 to be processed, improving the scanning from the reference direction Y perpendicular to the extension length of the laser beam B in related technologies to a vector direction scanning that is inclined relative to the reference direction Y. This allows the substrate 200 to be processed to have displacement not only in the reference direction Y, but also in the direction parallel to the extension length of the laser beam B during the laser scanning process. This increases the area of the substrate that is laser scanned in the Y-axis direction, thereby effectively increasing the area of the effective laser scanning area and improving the substrate utilization rate.
[0070] Specifically, Figure 1 The diagram shows the effective area of laser scanning when the substrate 200 to be processed moves along the reference direction (Y-axis) for laser scanning in the related art; Figure 2 The diagram shows the effective area of laser scanning in the excimer laser annealing apparatus provided in this embodiment of the present disclosure when the substrate 200 to be processed is moved along the second direction R for laser scanning.
[0071] Please see Figure 1 As shown, in related technologies, during laser scanning, the scanning path of the substrate 200 to be processed is along the Y-axis. However, in this embodiment, the scanning path of the substrate 200 to be processed has an inclined angle with the Y-axis. Assuming that the inclination angle of the substrate 200 to be processed relative to the reference direction Y remains unchanged, the scanning path of the substrate 200 to be processed is improved from moving along the reference direction Y to moving along the second direction R. In related technologies, the laser beam B scans the effective laser scanning area C1 on the surface of the substrate 200 to be processed along the reference direction Y, with a size Ly along the reference direction Y, and the laser beam B scans the area Dx on the surface of the substrate 200 to be processed along the first direction X. After optimizing the moving path of the substrate 200 to be processed in this embodiment, as shown... Figure 2 As shown, the effective laser scanning area formed by the laser beam B along the second direction R across the surface of the substrate 200 is C2. The size of the effective laser scanning area C2 along the second direction R is L(x+y), and the size of the laser beam B scanning across the surface of the substrate 200 along the first direction X is D(x+y). Obviously, L(x+y) > Ly, and D(x+y) > Dx. Therefore, after optimizing the movement path of the substrate 200 in this embodiment, the area of the effective laser scanning area is increased.
[0072] As an exemplary embodiment, such as Figure 2As shown, the first side 210 has a first angle α relative to the reference direction Y, and the second direction R has a second angle β relative to the reference direction Y, where α ≥ β ≥ -α.
[0073] Using the above scheme, the tilt angle of the moving direction of the substrate 200 relative to the reference direction Y should be reasonably selected to obtain a larger effective laser scanning area. The inventors of this application have discovered that the moving direction of the substrate 200 is related to the tilt angle of the first side 210 of the substrate 200 relative to the reference direction Y. When α ≥ β ≥ -α, a larger effective laser scanning area can be obtained. For example, α = β, that is, the moving direction of the substrate 200 and the extending direction of the first side 210 of the substrate 200 can be approximately the same.
[0074] As an exemplary embodiment, such as Figure 3 As shown, the laser unit 300 includes: a laser generator (not shown), a beam modulator 320, and a slit assembly 330. The laser generator is used to emit a laser beam B. The beam modulator 320 is disposed on the side of the laser generator 310 near the substrate stage 100 and located in the optical path of the laser beam B, and is used to modulate the laser beam B into a predetermined shape having a predetermined length along the first direction X, for example, Figure 3 As shown, the laser beam B can be modulated by the beam modulator 320 into a linear laser beam with a predetermined length along the first direction X; the slit assembly 330 is disposed in the optical path of the laser beam B and is located on the side of the beam modulator 320 away from the laser generator 310. The slit assembly 330 has a slit 331 through which the laser beam B can pass, and a first shielding member 332 and a second shielding member 333 surrounding the slit 331. The width of the slit 331 in the direction perpendicular to its own extension is adjustable.
[0075] By adopting the above solution, by setting the slit assembly 330, the width of the slit 331 on the slit assembly 330 is set to be adjustable. In this way, the range of the slit 331 blocking the laser beam B can be controlled by adjusting the width of the slit 331 at different scanning stages. This allows for adjustment of the irradiation range of the laser beam B on the substrate 200 to be processed at different scanning stages, thereby increasing the effective area of the laser scanning area and preventing the laser from irradiating the surface of the substrate stage 100.
[0076] It should be noted that, in conjunction with the optimization of the scanning path, the blocking range of the laser beam B by the slit 331 can be controlled by adjusting the width of the slit 331 at different laser scanning stages. For example, the laser scanning process can include a laser scanning start stage, a laser scanning middle stage, and a laser scanning end stage. Excess laser light can be blocked at the laser scanning start stage and the laser scanning end stage, while no blocking is required at the middle stage. It should be understood that the above is only an example and is not a limitation.
[0077] As an exemplary embodiment, such as, 3 and Figure 4 As shown, the slit assembly 330 further includes:
[0078] The first movable member 334 is connected to the first blocking member 332;
[0079] The second movable member 335 is connected to the second blocking member 333; wherein...
[0080] The first blocking member 332 and the second blocking member 333 are disposed opposite to each other in the second direction R, and the gap between the first blocking member 332 and the second blocking member 333 forms the slit 331;
[0081] The first movable member 334 and the second movable member 335 can move towards or away from each other along the reference direction Y or the second direction R to adjust the width of the slit 331 in a direction perpendicular to its extension.
[0082] Using the above scheme, the slit assembly 330 can be formed by two blocking members (first blocking member 332 and second light-shielding member) arranged opposite to each other, and the gap between the two light-shielding members is used to form a slit 331. The two blocking members are respectively connected to a movable member, and the width of the slit 331 can be adjusted by moving the movable member. The structure is simple and the operation is convenient.
[0083] As an exemplary embodiment, the first light-shielding member and the second light-blocking member 333 may be implemented by means of, but not limited to, a light-blocking plate; the first moving member and the second moving member may be implemented by means of, but not limited to, a moving plate.
[0084] Furthermore, as an exemplary embodiment, such as Figure 4 As shown, the slit assembly 330 further includes:
[0085] The first adjusting member 336 is connected between the first movable member 334 and the first blocking member 332;
[0086] The second adjusting member 337 is connected between the second movable member 335 and the second blocking member 333; wherein...
[0087] The first adjusting member 336 is movable relative to the first movable member 334, and causes the tilt angle of the first blocking member 332 relative to the second direction R to change; and the second adjusting member 337 is movable relative to the second movable member 335, and causes the tilt angle of the second blocking member 333 relative to the second direction R to change, so that the extension direction of the slit 331 is adjustable.
[0088] For example, the slit 331 can be adjusted to extend in a direction parallel to the second side 220, see [link to relevant documentation]. Figure 5 As shown, along the direction from the initial end of laser scanning to the final end of laser scanning, the first blocking member 332 and the second blocking member 333 can be sequentially arranged. In the initial stage of laser scanning, the first blocking member 332 can block a portion of the laser beam B, and the edge of the slit 331 formed by the first blocking member 332 is flush with the first side 210 of the substrate 200 to be processed. This can effectively prevent the laser beam B from irradiating the area outside the first side 210 of the substrate 200 to be processed. In the final stage of laser scanning, the second blocking member 333 can block a portion of the laser beam B, and the edge of the slit 331 formed by the second blocking member 333 is flush with the third side of the substrate 200 to be processed. This can effectively prevent the laser beam B from irradiating the area outside the third side of the substrate 200 to be processed.
[0089] For different application scenarios, the tilt angle of the substrate 200 to be processed is different. By adjusting the tilt angle of the first shielding member 332 and the second shielding member 333, the slit 331 can be adjusted to extend in a direction parallel to the second side 220.
[0090] As an exemplary embodiment, such as Figure 4 As shown, the first adjusting member 336 and the first movable member 334 are rotatably connected at the pivot via the first rotating shaft 338, and the second adjusting member 337 and the second movable member 335 are rotatably connected at the pivot via the second rotating shaft 339. The extension direction of the slit 331 can be adjusted by driving the first rotating shaft 338 and the second rotating shaft 339 to rotate via a motor.
[0091] As an exemplary embodiment, such as Figure 4As shown, the first adjusting member 336 includes a first connecting end 3361 connected to the first movable member 334 and a second connecting end 3362 connected to the first blocking member 332. The first connecting end 3361 is pivotally connected to the first movable member 334, and the second connecting end 3362 is rotatable about the pivot point to drive the first blocking member 332 to change the tilt angle relative to the second direction R.
[0092] The second adjusting member 337 includes a third connecting end 3371 connected to the second movable member 335 and a fourth connecting end 3372 connected to the second blocking member 333, wherein the third connecting end is pivotally connected to the second movable member 335 and the fourth connecting end is rotatable about the pivot point to drive the second blocking member 333 to change the tilt angle relative to the second direction R.
[0093] Using the above solution, the tilt angle of the first blocking member 332 can be adjusted by rotating the first adjusting member 336 around its pivot point with the first movable member 334; similarly, the tilt angle of the second blocking member 333 can be adjusted by rotating the second adjusting member 337 around its pivot point with the second movable member 335. In other words, the extension direction of the slit 331 is adjusted. This adjustment method is simple in structure and convenient to operate.
[0094] As an exemplary embodiment, such as Figure 4 As shown, either the first adjusting member 336 or the second adjusting member 337 may include a first rod 33a and a second rod 33b. The first rod 33a and the second rod 33b are cross-connected. The intersection point of the first rod 33a and the second rod 33b in the first adjusting member 336 serves as the first connecting end and is pivotally connected to the first movable member 334. The ends of the first rod 33a and the second rod 33b in the first adjusting member 336 away from the intersection point serve as the second connecting ends and are respectively connected to the first blocking member 332. Similarly, the intersection point of the first rod 33a and the second rod 33b in the second adjusting member 337 serves as the third connecting end and is pivotally connected to the second movable member 335. The ends of the first rod 33a and the second rod 33b in the second adjusting member 337 away from the intersection point serve as the fourth connecting ends and are respectively connected to the second blocking member 333.
[0095] As an exemplary embodiment, such as Figure 4 As shown, the first rod 33a and the second rod 33b are not of equal length. However, in other embodiments not shown, the first rod 33a and the second rod 33b may also be of the same length.
[0096] Furthermore, this disclosure also provides a method for preparing a polycrystalline silicon thin film, comprising the following steps:
[0097] Step S01: Form an amorphous silicon thin film on the substrate of the substrate to be processed 200;
[0098] Step S02: Anneal the amorphous silicon thin film of the substrate 200 to be processed using the excimer laser annealing apparatus provided in this embodiment of the present disclosure. Step S02 specifically includes:
[0099] Step S021: The substrate 200 to be processed is placed on the substrate stage 100 with the first side 210 tilted relative to the reference direction Y.
[0100] Step S022: The laser unit 300 emits a laser beam B and controls the substrate stage 100 to move relative to the laser beam B along the second direction R, so as to perform laser scanning on the amorphous silicon thin film on the substrate 200 to be processed.
[0101] Since the principle behind the polycrystalline silicon thin film preparation method is similar to that of the excimer laser annealing device, it is clear that this method can also bring about the beneficial effects of the excimer laser annealing device, and will not be elaborated further here.
[0102] Furthermore, by way of example, in the method, step S022 specifically includes:
[0103] Step S0221: Arrange the slit 331 of the slit assembly 330 to extend parallel to the second side 220, and arrange the first shielding member 332 and the second shielding member 333 along the direction from the laser scanning start end to the laser scanning end end.
[0104] Step S0222: In the initial stage of laser scanning, the slit 331 is adjusted to a first width. The first width is configured such that only a portion of the laser beam B passes through the slit 331 and is directed toward the substrate 200 to be processed, while the other portion of the laser beam B is blocked by the first blocking member 332.
[0105] Step S0223: In the intermediate stage of laser scanning, the slit 331 is adjusted to a second width, which is configured to allow the laser beam B to pass through the slit 331 and be directed toward the substrate 200 to be processed.
[0106] Step S0224: During the laser scanning termination stage, the slit 331 is adjusted to a third width, which is configured to allow only a portion of the laser beam B to pass through the slit 331 and be directed toward the substrate 200 to be processed, while the other portion of the laser beam B is blocked by the second shielding member 333.
[0107] In the above scheme, the slit 331 can be adjusted to extend along a direction parallel to the second side 220. Along the direction from the initial end of laser scanning to the end of laser scanning, the first shielding member 332 and the second shielding member 333 can be arranged sequentially. At the beginning stage of laser scanning, the first shielding member 332 can block a portion of the laser beam B, and the edge of the slit 331 formed by the first shielding member 332 can be flush with the first side 210 of the substrate 200 to be processed. In this way, the laser beam B can be effectively prevented from irradiating the area outside the first side 210 of the substrate 200 to be processed. At the end stage of laser scanning, the second shielding member 333 can block a portion of the laser beam B, and the edge of the slit 331 formed by the second shielding member 333 can be flush with the third side of the substrate 200 to be processed. In this way, the laser beam B can be effectively prevented from irradiating the area outside the third side of the substrate 200 to be processed.
[0108] It should be noted that during the transition from the initial stage of laser scanning to the intermediate stage of laser scanning, and during the transition from the intermediate stage of laser scanning to the termination stage of laser scanning, the trend of the slit 331 width of the slit assembly 330 is as follows: first, it gradually increases from the first width to the second width, then it keeps the second width unchanged, and finally it gradually decreases from the second width to the third width.
[0109] Specifically, please refer to the attached document. Figures 5 to 9 As shown, during the transition from the initial stage of laser scanning to the intermediate stage, at the start of laser scanning, the slit 331 of the slit assembly 330 extends parallel to the first side 210, and one edge of the first blocking member 332 forming the slit 331 is flush with the first side 210. The width of the slit 331 between the second blocking member 333 and the first blocking member 332 is the first width (…). Figure 5 As shown), the second shielding member 333 in the slit assembly 330 can move with the substrate 200 to be processed, so that the area of the laser beam B irradiating the substrate 200 to be processed gradually increases to the second width (as shown). Figure 6 (As shown); During the intermediate stage of the laser scanning, the width of the slit 331 of the slit assembly 330 remains unchanged at the second width until the position where the transition from the intermediate stage of the laser scanning to the termination stage of the laser scanning is required (as shown); Figure 7 As shown, as the substrate 200 to be processed moves, the slit assembly 330 gradually blocks the laser beam B to keep the laser beam B within the expected irradiation range. Figure 8As shown in the diagram, as the substrate 200 to be processed moves, the slit assembly 330 follows the substrate 200, causing the area of the laser beam B irradiating the substrate 200 to gradually decrease until the laser scan of the entire substrate 200 is completed. Figure 9 (As shown).
[0110] Let T be the total time taken for the entire laser scanning process, v be the moving speed of the substrate 200 to be processed, and t1 be the time when the substrate 200 to be processed starts moving, v be the reference time when the time is 0. Let t2 be the time taken for the initial stage of the laser scanning, t3 be the time taken for the middle stage of the laser scanning, and t3 be the time taken for the final stage of the laser scanning.
[0111] Where t1 = L1 / v, according to geometric principles, L1 is the length of the area outside the substrate 200 that is not irradiated by the laser beam B along the second direction R, that is, the length of the short side a of triangle A in the figure, where a is equal to b*tanα, so t1 = b*tanα / v, b is the length of the second side 220, and α is the tilt angle of the first side 210 relative to the reference direction Y.
[0112] Based on the same principle, t3 = b * tanα / v, t2 = T - t1 - t2.
[0113] It should be understood that the above is only an example, and in practical applications, the width adjustment method of the slit assembly 330 is not limited to this.
[0114] The following points need to be explained:
[0115] (1) The accompanying drawings of the embodiments of this disclosure only involve the structures involved in the embodiments of this disclosure. Other structures can be referred to the general design.
[0116] (2) For clarity, the thickness of layers or regions is enlarged or reduced in the drawings used to describe embodiments of the present disclosure, i.e., these drawings are not drawn to actual scale. It will be understood that when an element such as a layer, film, region or substrate is referred to as being “above” or “below” another element, the element may be “directly” located “above” or “below” the other element or there may be intermediate elements.
[0117] (3) Where there is no conflict, the embodiments of this disclosure and the features in the embodiments can be combined with each other to obtain new embodiments.
[0118] The above are merely specific embodiments of this disclosure, but the scope of protection of this disclosure is not limited thereto. The scope of protection of this disclosure shall be determined by the scope of the claims.
Claims
1. An excimer laser annealing apparatus, characterized in that, include: A substrate stage is used to hold the substrate to be processed. and A laser unit is provided, wherein the laser unit is used to emit a laser beam onto the bearing surface of the substrate stage, and the laser beam has an extension length along a first direction, the first direction being parallel to the substrate to be processed; wherein, The substrate to be processed includes a first side and a second side disposed adjacent to each other, and the substrate to be processed is disposed on the substrate stage with the first side inclined relative to a reference direction. The reference direction is perpendicular to the first direction and the plane defined by the first direction is parallel to the substrate to be processed. The substrate stage is capable of moving relative to the laser beam along a second direction, which is a vector direction that is inclined relative to both the first direction and the reference direction. The laser unit includes: A laser generator is used to emit a laser beam; A beam modulator, disposed on the side of the laser generator near the substrate stage and located in the optical path of the laser beam, is used to modulate the laser beam into a predetermined shape having a predetermined length along the first direction; and A slit assembly is disposed in the optical path of the laser beam and located on the side of the beam modulator away from the laser generator. The slit assembly has a slit through which the laser beam can pass, and a first shielding member and a second shielding member that enclose the slit. The slit extends in a direction parallel to the second side, and the width of the slit in a direction perpendicular to its own extension direction is adjustable.
2. The excimer laser annealing apparatus according to claim 1, characterized in that, The first side has a first angle α relative to the reference direction, and the second direction has a second angle β relative to the reference direction, where α ≥ β ≥ -α.
3. The excimer laser annealing apparatus according to claim 2, characterized in that, α=β。 4. The excimer laser annealing apparatus according to claim 1, characterized in that, The slit assembly also includes: The first movable member is connected to the first blocking member; The second movable member is connected to the second blocking member; wherein... The first blocking member and the second blocking member are disposed opposite to each other in the second direction, and the gap between the first blocking member and the second blocking member forms the slit; the first movable member and the second movable member can move towards or away from each other along the reference direction or the second direction to adjust the width of the slit in the direction perpendicular to its extension.
5. The excimer laser annealing apparatus according to claim 4, characterized in that, The slit assembly also includes: The first adjusting member is connected between the first movable member and the first blocking member; The second adjusting member is connected between the second movable member and the second blocking member; wherein... The first adjusting member is movable relative to the first movable member, and causes the tilt angle of the first blocking member relative to the second direction to change; and the second adjusting member is movable relative to the second movable member, and causes the tilt angle of the second blocking member relative to the second direction to change, so that the extension direction of the slit is adjustable.
6. The excimer laser annealing apparatus according to claim 5, characterized in that, The first adjusting member includes a first connecting end connected to the first movable member and a second connecting end connected to the first blocking member, wherein the first connecting end is pivotally connected to the first movable member, and the second connecting end is rotatable about the pivot point to drive the tilt angle of the first blocking member relative to the second direction to change. The second adjusting member includes a third connecting end connected to the second movable member and a fourth connecting end connected to the second blocking member, wherein the third connecting end is pivotally connected to the second movable member, and the fourth connecting end is rotatable about the pivot point to drive the second blocking member to change the tilt angle relative to the second direction.
7. A method for preparing a polycrystalline silicon thin film, characterized in that, Includes the following steps: An amorphous silicon thin film is formed on the substrate of the substrate to be processed; Annealing an amorphous silicon thin film on a substrate to be treated using the excimer laser annealing apparatus as described in any one of claims 1 to 6, specifically includes: The substrate to be processed is placed on the substrate carrier with the first side inclined relative to the reference direction; The laser unit emits a laser beam, and the substrate stage is controlled to move relative to the laser beam along a second direction to perform laser scanning on the amorphous silicon thin film on the substrate to be processed.
8. The method for preparing polycrystalline silicon thin films according to claim 7, characterized in that, When applied to the excimer laser annealing apparatus as described in claim 4, the method involves emitting a laser beam through the laser unit and controlling the substrate stage to move relative to the laser beam along a second direction to perform laser scanning on the amorphous silicon thin film on the substrate to be processed, specifically including: The slit of the slit assembly is arranged to extend parallel to the second side, and the first shield and the second shield are arranged along the direction from the laser scanning start end to the laser scanning end end. At the beginning of the laser scanning phase, the slit is adjusted to a first width, which is configured to allow only a portion of the laser beam to pass through the slit and be directed toward the substrate to be processed, while the other portion of the laser beam is blocked by the first shielding member. During the intermediate stage of laser scanning, the slit is adjusted to a second width, which is configured to allow the laser beam to pass entirely through the slit and be directed toward the substrate to be processed. During the laser scanning termination phase, the slit is adjusted to a third width, which is configured to allow only a portion of the laser beam to pass through the slit and be directed toward the substrate to be processed, while the other portion of the laser beam is blocked by the second shielding member.
9. The method for preparing polycrystalline silicon thin films according to claim 8, characterized in that, In the method, a laser beam is emitted by the laser unit, and the substrate stage is controlled to move relative to the laser beam along a second direction to perform laser scanning on the amorphous silicon thin film on the substrate to be processed. Specifically, the method further includes: Let the total time of the laser scanning process be T, the moving speed of the substrate to be processed be v, and take the time when the substrate to be processed starts moving as 0 as the reference. Let the duration of the initial stage of the laser scanning be t1, the duration of the middle stage of the laser scanning be t2, and the duration of the final stage of the laser scanning be t3. Let t1 = b * tanα / v, t3 = b * tanα / v, and t2 = T - t1 - t2, where b is the length of the second side and α is the tilt angle of the first side relative to the reference direction.