Laser annealing method and photoetching method

Abstract

The invention provides a laser annealing method. Specifically, a second track (stepping track) between adjacent first tracks (adjacent scanning tracks) can be optimized into at least one curve track, and the second track is tangent to the adjacent first tracks, so that the stepping track of the adjacent scanning tracks is optimized into an arc track tangent to the stepping track, and the scanning track is optimized into at least one curve track. According to the invention, the laser can continuously emit light in the step scanning process, the annealing uniformity of the wafer is improved, the scanning time required by the step scanning track is reduced, the total annealing time of the wafer is further reduced, and the yield of the wafer is improved.

Description

Technical Field

[0001] The present invention relates to the field of lithography machines, and particularly to a laser annealing method and a lithography method. Background Art

[0002] During the laser annealing process, an annealing scan path needs to be formed for the object to be annealed first, and then the object to be annealed (such as a wafer) carried by a workpiece table performs a scanning motion along the X direction or the Y direction in cooperation with a laser for emitting a laser beam spot located above the workpiece table.

[0003] Currently, in the annealing scan path formulated by the prior art, the step-by-step scanning process from the previous scan trajectory to the next scan trajectory is usually completed by multiple broken line segments. Therefore, after the workpiece table drives the wafer to complete the scanning motion of the previous scan trajectory, it needs to decelerate to a stop along a straight line, and then step to the next scan trajectory along a straight line through an acceleration and deceleration process, and then start the acceleration process, and then enter the wafer again to start annealing.

[0004] However, repeatedly experiencing the step-by-step motion process of deceleration, stop, and acceleration will inevitably cause the laser annealing equipment to take too long to step from the annealing of the previous scan trajectory to the start of annealing of the next scan trajectory, resulting in low productivity. In addition, due to the existence of the deceleration, stop, and acceleration processes, in order to avoid damage to the chuck caused by the laser spot hitting the same point on the chuck for too long, the energy of the laser is usually reduced, which leads to unstable light output energy when the laser scans the edge of the silicon wafer, and further causes the problem of uneven annealing of the entire wafer. Summary of the Invention

[0005] The purpose of the present invention is to provide a laser annealing method and a lithography method to improve the annealing uniformity of the entire wafer, reduce the step time required for scanning the second trajectory, reduce the total annealing time of the wafer, and improve the product productivity.

[0006] In a first aspect, to solve the above technical problems, the present invention provides a laser annealing method, which may at least include:

[0007] Providing a laser unit;

[0008] Providing a wafer;

[0009] Relatively moving the laser unit and the wafer to complete the annealing of the wafer;

[0010] Wherein, relatively moving the laser unit and the wafer includes irradiating a first trajectory of the wafer and a plurality of second trajectories connecting adjacent first trajectories with the laser emitted by the laser unit, and at least one segment of the second trajectories is a curved trajectory.

[0011] In some alternative examples, the second trajectory connecting the i-th and the (i + 1)-th first trajectories is tangent to the i-th first trajectory at its starting position and tangent to the (i + 1)-th first trajectory at the terminating position of the second trajectory, where i≥1.

[0012] In some alternative examples, the shape of the curved trajectory includes at least one of: an arc shape, an exponential function curve shape, and a trigonometric function curve shape.

[0013] In some alternative examples, the second trajectory is composed of at least one first curved trajectory and at least one straight trajectory tangent thereto.

[0014] In some alternative examples, the second trajectory is composed of at least one second curved trajectory and at least one third curved trajectory tangent thereto.

[0015] In some alternative examples, the second trajectory connecting the i-th and the (i + 1)-th first trajectories is tangent to the i-th first trajectory at its starting position and tangent to the (i + 1)-th first trajectory at the terminating position of the second trajectory, including:

[0016] The terminating position of the i-th first trajectory is on the same horizontal line as the first straight trajectory, the terminating position of the first straight trajectory coincides with the starting position of the first curved trajectory, and the terminating position of the first curved trajectory coincides with the starting position of the (i + 1)-th first trajectory.

[0017] In some alternative examples, the second trajectory connecting the i-th and the (i + 1)-th first trajectories is tangent to the i-th first trajectory at its starting position and tangent to the (i + 1)-th first trajectory at the terminating position of the second trajectory, including:

[0018] The terminating position of the i-th first trajectory coincides with the starting position of the second curved trajectory, the terminating position of the second curved trajectory coincides with the starting position of the third curved trajectory, and the terminating position of the third curved trajectory coincides with the starting position of the (i + 1)-th first trajectory.

[0019] In some alternative examples, the extension line of the line connecting the center of the second curved trajectory to the center of the third curved trajectory passes through the terminating position of the second curved trajectory and the starting position of the third curved trajectory that coincides with the terminating position.

[0020] In some alternative examples, when the laser unit and the wafer are relatively moved, the energy of the laser unit when emitting laser to form the first trajectory is the same as the energy when forming the second trajectory.

[0021] In some of these alternative examples, when the laser unit and the wafer are relatively moved, the scanning speed of the first trajectory and the stepping speed of the second trajectory are the same.

[0022] In some of these alternative examples, when the laser unit and the wafer are relatively moved, both the laser unit and the wafer move at a constant speed.

[0023] In a second aspect, based on the same inventive concept, the present invention further provides a lithography method, and the lithography method at least includes the laser annealing method as described above.

[0024] Compared with the prior art, the technical solution of the present invention has at least one of the following beneficial effects:

[0025] In the laser annealing method provided by the present invention, the second trajectory (stepping trajectory) between adjacent first trajectories (adjacent scanning trajectories) is optimized to at least one curved trajectory, and the second trajectory is tangent to each of the adjacent first trajectories. The unexpected effect obtained is that by optimizing the stepping trajectory between adjacent scanning trajectories to an arc trajectory tangent to each of them, the laser can continuously emit light during the step-and-scan process, solving the problems in the prior art that in order to avoid damage to other components of the workpiece stage during the step-and-scan process, the laser needs to be turned off multiple times, resulting in unstable laser energy and large differences in annealing uniformity between the edge and the middle part of the wafer, that is, improving the annealing uniformity of the wafer.

[0026] Moreover, by optimizing the stepping trajectory between adjacent scanning trajectories to a curved trajectory tangent to each of them, it can further ensure that the step-and-scan process is also a constant-speed motion process, that is, there is no need to experience the step-and-scan process from the previous scanning trajectory to the next scanning trajectory completed by multiple broken lines in the prior art, where the workpiece stage needs to decelerate to a stop along a straight line and then accelerate and decelerate along a straight line to complete the step-and-scan process, reducing the scanning time required for the stepping trajectory, thereby reducing the total annealing time of the wafer and improving the wafer yield. Description of the Drawings

[0027] Figure 1 It is a schematic diagram of a scanning path in a straight-line scanning mode composed of multiple broken lines formulated by the prior art for a wafer;

[0028] Figure 2 It is a schematic diagram of a scanning path in an arc scanning mode composed of multiple broken lines formulated by the prior art for a wafer;

[0029] Figure 3 For Figure 1 The enlarged schematic diagram of the partial scanning path shown;

[0030] Figure 4 Schematic flow diagram of a laser annealing method provided in an embodiment of the present invention;

[0031] Figure 5 Schematic diagram of an annealing scan path formed when a wafer is subjected to a linear scan mode in an embodiment of the present invention;

[0032] Figure 6 For the Figure 5 partial enlarged view;

[0033] Figure 7 Partial enlarged view of another annealing scan path formed when a wafer is subjected to a linear scan mode in an embodiment of the present invention. Detailed implementation manners

[0034] Next, the technical solutions in the present invention will be clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0035] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance. In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0036] According to the prior art, when a laser annealing device performs annealing treatment on a wafer, it is necessary to formulate an annealing scan path for it, and the annealing scan path may specifically include a plurality of scan trajectories, as well as a step trajectory for transitioning from the previous scan trajectory to the next scan trajectory.

[0037] Refer to Figures 1 - 2 , Figure 1 is a schematic diagram of a scan path in a linear scan mode composed of multiple broken lines formulated for a wafer in the prior art, Figure 2 is a schematic diagram of a scan path in an arc scan mode composed of multiple broken lines formulated for a wafer in the prior design.

[0038] Such asFigure 1 As shown, in the prior art, the path of the workpiece table driving the wafer for annealing scanning is specifically as follows: starting from point A, along the Figure 1 arrow direction shown, passing through point B, point C, point D in sequence, and scanning all endpoints of the broken line in sequence until reaching point M. Among them, the multiple line segments passing through the wafer and serving as the scanning trajectory are parallel to each other and have equal spacing. For example, the spacing between line segment DC and line segment EF is d.

[0039] Refer to Figure 3 , Figure 3 To Figure 1 is an enlarged schematic diagram of the local scanning path shown. As Figure 3 shown, the stepping trajectory of the prior art from one scanning trajectory to another scanning trajectory is a linear scanning path with multiple inflection points composed of line segment F’F, line segment FG, and line segment GG’. Among them, the point F’ is the termination position where the previous scanning trajectory leaves the wafer, and the point G’ is the starting position where the next scanning trajectory enters the wafer.

[0040] For the sake of convenience of description, a plurality of auxiliary lines are set in the Figure 3 , such as line segment F’H’, line segment FH. Among them, FH = F’H’ = d. In some examples, FF’ = GG’ = HH’ = 5 mm, and d = 2.5 mm.

[0041] Obviously, in the existing scanning path, when the workpiece table drives the wafer to move from point F’ to point G’, it has to pass through point F and point G in sequence. When passing through point F’, the workpiece table is in a uniform speed state, and then it has to decelerate to reach point F; therefore, during the stepping scanning process from point F to point G, the prior art needs to first perform an acceleration motion, then a uniform speed motion, and then a deceleration motion; and when moving from point G to point G’, it also has to experience a process of first performing an acceleration motion and then a uniform speed motion.

[0042] However, repeatedly experiencing the stepping motion process of deceleration, stop, and acceleration as described above will inevitably cause the problem that the laser annealing equipment takes too long to step to the next scanning trajectory after completing the annealing of the previous scanning trajectory and before starting the annealing, resulting in low productivity.

[0043] Moreover, in the prior art, the stepping scanning process from the previous scanning trajectory to the next scanning trajectory is completed by connecting broken lines. Due to the process of decelerating to stop and then accelerating, in order to avoid the laser spot hitting the same point on other components of the workpiece table (such as the chuck under the wafer) for too long, thereby causing damage to the components, the laser is controlled to stop emitting light, and then emit light after stepping to the next scanning trajectory. This results in an unstable light emission energy when the laser scans the edge of the wafer, while this situation does not exist inside the silicon wafer, thus resulting in the problem of poor annealing uniformity across the entire wafer.

[0044] To solve the above problems, the present invention provides a specific solution for optimizing the laser annealing scanning path, as well as a laser annealing method and a lithography method based on the optimized laser annealing scanning path scheme, so as to improve the annealing uniformity of the entire wafer while reducing the stepping time required for scanning the second track, reducing the total annealing time of the wafer, and improving the product yield.

[0045] Refer to Figure 4 , Figure 4 which is a schematic flow chart of a laser annealing method provided in an embodiment of the present invention. As Figure 4 shown, the laser annealing method may at least include the following steps:

[0046] Step S401: Provide a laser unit;

[0047] Step S402: Provide a wafer;

[0048] Step S403: Relatively move the laser unit and the wafer to complete annealing of the wafer. Wherein, relatively moving the laser unit and the wafer includes using the laser emitted by the laser unit to irradiate a first track of the wafer and multiple second tracks connecting adjacent first tracks, and at least one segment of the second track is a curved track.

[0049] Obviously, in the annealing scanning track provided in the embodiment of the present invention, the optimization scheme in which at least one segment of the second track is optimized to be a curved track includes: the second track is composed of at least one segment of a curved track, the second track is composed of at least one segment of a curved track and at least one segment of a straight track, and the second track is composed of multiple segments of curved tracks.

[0050] For the sake of simplicity of description, hereinafter, only the scheme in which the second track is composed of at least one segment of a curved track and at least one segment of a straight track and the scheme in which the second track is composed of multiple segments of curved tracks are used to introduce the optimized annealing scanning path provided in the embodiment of the present invention.

[0051] It should be noted that the scanning methods based on the laser annealing equipment can be roughly divided into: a linear scanning method and an arc scanning method. Among them, the linear scanning method means that the movement trajectories of multiple light spots forming each scanning track in the annealing scanning path are linear, and the arc scanning method means that the movement trajectories of multiple light spots forming each scanning track in the annealing scanning path are arc-shaped. And regardless of whether it is the linear scanning method or the arc scanning method, the multiple scanning tracks divided by the wafer can be arranged along the X direction or along the Y direction, and the X direction and the Y direction are perpendicular.

[0052] For the sake of simplicity in description, in the following, taking the example of arranging multiple scanning trajectories in sequence along the Y direction and performing step-by-step scanning on the multiple scanning trajectories, while performing left-right movement scanning along the X direction on each of the scanning trajectories, the laser annealing method proposed in the embodiments of the present invention will be described.

[0053] Embodiment 1

[0054] Refer to Figures 5 - 6 , Figure 5 which is a schematic diagram of an annealing scanning path formed when performing a linear scanning method on a wafer provided in an embodiment of the present invention. Figure 6 is the Figure 5 partial enlarged view.

[0055] Specifically, based on the annealing scanning paths as shown in Figure 5 and Figure 6 , the laser annealing method provided in an embodiment of the present invention may specifically include the following steps:

[0056] Step S1: Provide a laser unit, and the laser unit at least includes a laser, and the laser is used to emit laser light that irradiates on the wafer.

[0057] Step S2: Provide a wafer.

[0058] In this step, for the wafer with a circular shape, it can be first divided into multiple first trajectories (multiple scanning trajectories) arranged in sequence along the X direction or the Y direction, and each of the first trajectories includes multiple light spots, that is, each of the first trajectories is a light spot trajectory composed of multiple light spots, simply referred to as the first trajectory, such as Figure 5 the l1, l2, etc. shown, and then for any two adjacent first trajectories, such as the l1 and l2, a curve trajectory is set for both of them, simply referred to as the second trajectory, and the second trajectory can be composed of at least one straight line trajectory and at least one curve trajectory, such as Figure 6 the curve trajectory composed of the straight line segment F’F and the arc segment FG’ shown.

[0059] Among them, if the multiple first trajectories corresponding to the wafer division are the 1st first trajectory, the i-th first trajectory, the (i + 1)-th first trajectory,..., then the second trajectory connecting the i-th first trajectory and the adjacent (i + 1)-th first trajectory is tangent to the i-th first trajectory at the starting position of the second trajectory and tangent to the (i + 1)-th first trajectory at the ending position of the second trajectory, where i≥1.

[0060] In this embodiment, the second trajectory connecting the i-th first trajectory and the (i + 1)-th first trajectory is tangent to the i-th first trajectory at its starting position, which means that the end position of the i-th first trajectory and the first straight-line trajectory forming the second trajectory are on the same horizontal line, and the end position of the first straight-line trajectory coincides with the starting position of the first curved trajectory, and the end position of the first curved trajectory coincides with the starting position of the (i + 1)-th first trajectory.

[0061] As an example, if the second trajectory connecting the first trajectory l1 and the first trajectory l2 is specifically composed of a section of first straight-line trajectory and a section of curved trajectory, that is, as Figure 6 the curved trajectory shown, which may specifically include the straight-line segment F’F and the arc segment FG’, then the first trajectory l1 is connected to the straight-line segment F’F at the position where it leaves the wafer (the end position of the first trajectory l1), that is, the end position of the first trajectory l1 coincides with the starting position F’ of the straight-line segment F’F at their connection, and moreover, the straight-line segment F’F and the first trajectory l1 are on the same horizontal line, and the straight-line segment F’F is tangent to the arc segment FG’ at their coincidence, and the arc segment FG’ is tangent to the first trajectory l2 at their coincidence, thereby forming a continuous scanning curved trajectory starting from the end position of the first trajectory l1 and ending at the starting position of the first trajectory l2.

[0062] Obviously, since in this embodiment, the step-scanning process (the second trajectory) from the previous first trajectory to the next first trajectory is optimized into a curved trajectory, and this curved trajectory is tangent to the two adjacent first trajectories in sequence, so that after the workpiece stage of the laser annealing equipment drives the wafer to perform a scanning motion along the previous first trajectory at a constant speed, it can directly perform a step-scanning motion at a constant speed without changing the speed, that is, the acceleration and deceleration processes are eliminated, the duration required for the step-scanning trajectory (the second trajectory) is reduced, and further the total scanning time of the wafer is reduced.

[0063] Step S3: Relatively move the laser unit and the wafer to complete the annealing of the wafer.

[0064] In this step, the wafer can be loaded onto the workpiece stage by the manipulator of the laser annealing equipment, and then steps such as focusing, leveling, and alignment are completed. After that, the annealing energy of the laser of the laser annealing equipment (such as 3000W) is set, and the moving speed of the workpiece stage (such as 400 mm / s) is set, and then starting from the first trajectory of the 1st annealing scanning trajectory formed in the above step S2, laser scanning is performed.

[0065] Specifically, before the workpiece stage carrying the wafer performs laser scanning of the first first trajectory, it can first perform an acceleration motion, and after reaching a uniform speed, enter the starting position of the first first trajectory, and then start to execute the annealing process in which the energy of the laser is stabilized at 3000W, the emission spot speed remains unchanged, and the movement speed of the workpiece stage also remains unchanged until the termination position of the last first trajectory is scanned.

[0066] As an example, if the first first trajectory is the l1, when starting to scan the first trajectory l1, the laser emits laser at a uniform speed of 400 mm / s, and the workpiece stage scans from the starting position to the termination position of the first trajectory l1 (from left to right), and then scans at a uniform speed to the starting spot position point F' of the upper curve trajectory. At this point, at the position of this point F', the energy of the laser is maintained at the annealing energy of 3000W, and no deceleration action is performed, that is, the uniform movement speed of the workpiece stage is continuously maintained. Subsequently, the speed of the workpiece stage is continuously maintained at 400 mm / s. According to the trajectory planning method, it directly moves from point F' to point F in a curve. During this process, the laser continuously emits light, and the workpiece stage performs uniform circular motion, and its linear speed always remains unchanged. After that, the speed of the workpiece stage is continuously maintained at 400 mm / s. According to the trajectory planning method, it moves from point F to point G' in a curve. During this process, the workpiece stage still performs uniform circular motion, and its linear speed always remains unchanged. And when the workpiece stage moves to point G', it enters the scanning trajectory of the second first trajectory, such as l2, to start the annealing process operation of the second first trajectory. After that, under the condition that the energy of the laser, the light emission speed, and the movement speed of the workpiece stage remain unchanged, the remaining first trajectories and second trajectories are scanned at a uniform speed in turn.

[0067] For better understanding, the trajectory tangency described in the embodiments of the present invention is as follows. Figure 5 The following introduces the corresponding positional relationship when the trajectories are tangent by adding auxiliary lines in

[0068] Refer to Figure 6 , the dotted lines in the figure are auxiliary lines made for help in understanding. Among them, the auxiliary line F'H' is perpendicular to the auxiliary line F'F, the auxiliary line F'H' is perpendicular to the auxiliary line H'G', the auxiliary line FG' is perpendicular to the auxiliary line F'F, and the auxiliary line FG' is perpendicular to the auxiliary line H'G'. That is, F'FG'H' is a rectangle. The straight line segment F'F is an extension of the first trajectory l1 (the first trajectory is a line segment), the line segment H'G' is a part of the first trajectory l2, the auxiliary line l is the perpendicular bisector of the auxiliary line F'H', and at the same time, it is also the perpendicular bisector of the arc segment FG'. At the same time, the arc segment FG' is tangent to the straight line segment F'F and also tangent to the line segment H'G'. The arc segment FG' is a semi-circle, and the arc segment FG' intersects the auxiliary line l at point O. The auxiliary line l' passes through point O and is tangent to the arc segment FG'.

[0069] Obviously, since the step-scanning process (the second trajectory) from the previous first trajectory to the subsequent first trajectory proposed in this embodiment adopts a continuous scanning trajectory, it can be ensured that the workpiece stage can move at a constant speed during the scanning process of the second trajectory. As a result, during the scanning process of the second trajectory, there is no need to control the laser to stop emitting light, as in the prior art, to avoid the laser spot hitting the same point on other components of the workpiece stage (such as the chuck under the wafer) for too long, which may cause damage to the components, and then emit light again after stepping to the next scanning trajectory, thus resulting in poor uniformity of full-wafer annealing of the wafer.

[0070] It should be noted that when each of the second trajectories is composed of at least one straight trajectory and at least one curved trajectory, as Figures 5 - 6 shown, the transition from the straight trajectory to the curved trajectory can be located at their coincidence point, such as point F, or can be located on the left or right side of their coincidence point (such as point F); and the curved trajectory (such as the arc segment FG’) can be an arc, or can be an elliptical arc, hyperbola, quadratic function curve, etc., as long as it is ensured that the trajectories of multiple straight lines and curves are tangent to each other and the scanning trajectory is continuous.

[0071] Moreover, there is at least one point on the straight trajectory and the curved trajectory of the formed continuous scanning trajectory, and the tangent of the connecting trajectory passing through this point is perpendicular to the tangent of the first trajectory (such as l1) at their coincidence point (such as point F’). These points are defined as optimized turning points, and the perpendicular line (such as l) of the tangent of the connecting trajectory passing through each of the optimized turning points is parallel to the multiple first trajectories, and adjacent two first trajectories are symmetrically arranged with respect to the perpendicular line (such as l1 and l2 are symmetric with respect to l).

[0072] Embodiment 2

[0073] Refer to Figure 7 , Figure 7 which is a partial enlarged view of another annealing scanning path formed when performing a linear scanning method on a wafer provided in an embodiment of the present invention.

[0074] Specifically, based on the annealing scanning path as Figure 7 shown, the laser annealing method provided in an embodiment of the present invention may specifically include the following steps:

[0075] Step S1, provide a laser unit, the laser unit at least includes a laser, and the laser is used to emit laser light to the wafer.

[0076] Step S2, provide a wafer.

[0077] In this embodiment, for the wafer with a circular shape, the wafer can be first divided into a plurality of first trajectories (multiple scanning trajectories) arranged in sequence along the X direction or the Y direction, and each of the first trajectories includes a plurality of light spots, such as Figure 7 l1, l2, etc. shown, and then for any two adjacent first trajectories, such as l1 and l2, a curve trajectory, that is, the second trajectory, is set for both of them, and the second trajectory can be composed of at least two curve trajectories, such as Figure 6 The curve trajectory composed of the arc segment AB and the arc end BC shown.

[0078] Among them, if the multiple first trajectories corresponding to the wafer division are the 1st first trajectory, the i-th first trajectory, the (i + 1)-th first trajectory,..., then the second trajectory connecting the i-th first trajectory and the adjacent (i + 1)-th first trajectory is tangent to the i-th first trajectory at the starting position of the second trajectory and tangent to the (i + 1)-th first trajectory at the ending position of the second trajectory, where i ≥ 1.

[0079] In this embodiment, the ending position of the i-th first trajectory (such as point A of l1) coincides with the starting position of the arc segment AB, the ending position of the arc segment AB coincides with the starting position of the arc segment BC, and the ending position of the arc segment BC coincides with the starting position of the (i + 1)-th first trajectory (such as point C of l2).

[0080] As an example, if the second trajectory connecting the first trajectory l1 and the first trajectory l2 is specifically composed of two curve trajectories, that is, as Figure 6 The curve trajectory shown, which specifically includes the arc segment AB and the arc segment BC, then the first trajectory l1 is connected to the arc segment AB at the position where it leaves the wafer (the ending position of the first trajectory l1), that is, the ending position of the first trajectory l1 coincides with the starting position A of the arc segment AB at their connection, and moreover, if the first trajectory l1 is a linear scanning trajectory, the tangent at the starting position of the arc segment AB is on the same horizontal line as the first trajectory l1.

[0081] Furthermore, the arc segment AB is tangent to the arc segment BC at their coincidence, and the arc segment BC is tangent to the first trajectory l2 at their coincidence, thereby forming a continuous scanning curve trajectory starting from the ending position of the first trajectory l1 and ending at the starting position of the first trajectory l2, and if the first trajectory l2 is a linear scanning trajectory, the tangent at the ending position of the arc segment BC is on the same horizontal line as the first trajectory l2.

[0082] For better understanding, the trajectory tangency described in the embodiments of the present invention is as follows. Below, by adding auxiliary lines in Figure 7 the positional relationship corresponding to the trajectory tangency is introduced.

[0083] Referring to Figure 7 , an auxiliary line AH' can be drawn through point A at the termination position of the first trajectory l1, and AH' is perpendicular to the first trajectory l2. At the same time, an auxiliary line O2C can be drawn through point C at the starting position of the first trajectory l2, and O2C is perpendicular to the first trajectory l2. The center O1 is located on the auxiliary line AH'. The center of the arc segment AB is O1, and its central angle ∠AO1B = π / 3. The center O2 is located on the auxiliary line O2C and on the auxiliary line O1B. The center of the arc segment BC is O2. At the same time, the two arc segments are tangent at point B, the arc segment AB is tangent to the first trajectory l1, and the arc segment BC is tangent to the first trajectory l2. An auxiliary line l parallel to the first trajectory l2 is drawn through point O2, and the auxiliary line l intersects the trajectory ABC at point O. An auxiliary line l' tangent to the arc segment BC is drawn through point O.

[0084] Obviously, since in this embodiment, the step-by-step scanning process (the second trajectory) from the previous first trajectory to the next first trajectory is optimized into a curve trajectory, and this curve trajectory is successively tangent to the two adjacent first trajectories, the workpiece stage of the laser annealing equipment can directly perform a step-by-step scanning movement at a constant speed after driving the wafer to perform a scanning movement along the previous first trajectory at a constant speed, without the need for a speed change, that is, the acceleration and deceleration processes are eliminated, the duration required for the step-by-step scanning trajectory (the second trajectory) is reduced, and the total scanning time of the wafer is further reduced.

[0085] Step S3, relatively move the laser unit and the wafer to complete the annealing of the wafer.

[0086] In this step, the wafer can be loaded onto the workpiece stage by the manipulator of the laser annealing equipment, and then steps such as focusing, leveling, and alignment are completed. After that, the annealing energy of the laser of the laser annealing equipment (such as 3000W) is set, and the movement speed of the workpiece stage (such as 400 mm / s) is set, and then starting from the first first trajectory of the annealing scanning trajectory formed in the above step S2, laser scanning is performed.

[0087] Specifically, before performing the laser scanning of the first first trajectory, the workpiece stage carrying the wafer can first perform an acceleration movement, and after reaching a constant speed, enter the starting position of the first first trajectory, and then start to execute the annealing process in which the energy of the laser is stabilized at 3000W, the emission spot speed remains unchanged, and the movement speed of the workpiece stage also remains unchanged until the termination position of the last first trajectory is scanned.

[0088] As an example, if the first first trajectory is the l1, when starting to scan the first trajectory l1, the laser emits laser at a constant speed of 400 mm / s. The workpiece stage scans from the starting position to the ending position of the first trajectory l1 (from left to right), and then scans at a constant speed to the starting position point A of the upper curve trajectory. At this point A, the energy of the laser is maintained at the annealing energy of 3000 W, and no deceleration action is performed, that is, the constant speed of the workpiece stage is continuously maintained. Subsequently, the speed of the workpiece stage remains unchanged at 400 mm / s. According to the trajectory planning method, it directly moves from point A to point B in a curve. During this process, the laser keeps emitting light continuously, while the workpiece stage makes a uniform circular motion with its linear velocity remaining constant all the time. After that, the speed of the workpiece stage remains unchanged at 400 mm / s. According to the trajectory planning method, it moves from point B to point C in a curve. During this process, the workpiece stage still makes a uniform circular motion with its linear velocity remaining constant all the time. And when the workpiece stage moves to point C, it enters the scanning trajectory of the second first trajectory, such as l2, to start the annealing process operation of the second first trajectory. After that, under the condition that the energy of the laser, the light emission speed, and the movement speed of the workpiece stage remain unchanged, the remaining first trajectories and second trajectories are scanned at a constant speed in sequence.

[0089] Obviously, since the step scanning process (second trajectory) from the previous first trajectory to the next first trajectory proposed in this embodiment adopts the continuous scanning trajectory method, it can ensure that the workpiece stage can move at a constant speed during the scanning process of the second trajectory. Furthermore, during the scanning process of the second trajectory, there is no need to control the laser to stop emitting light like in the prior art to avoid the problem of the laser spot hitting the same point on other components of the workpiece stage (such as the chuck under the wafer) for too long time, which may cause damage to the components, and then wait until stepping to the next scanning trajectory to emit light again, resulting in poor uniformity of the full wafer annealing.

[0090] It should be noted that when each of the second trajectories is composed of at least two curve trajectories, as Figure 7 shown, the curve trajectories (such as arc segments AB and BC) can be arcs, or can be elliptical arcs, hyperbolas, quadratic function curves, etc., as long as it is ensured that the trajectories between multiple straight lines and curves are tangent and the scanning trajectories are continuous.

[0091] Moreover, there is at least one point on the two curve trajectories that form the continuous scanning trajectory after connection. The tangent of the connection trajectory passing through this point is perpendicular to the tangent of the first trajectory (such as l1) at their coincidence point (such as point A). These points are defined as optimized turning points. The perpendicular line (such as l) of the tangent of the connection trajectory passing through each of the optimized turning points is parallel to the multiple first trajectories, and two adjacent first trajectories are symmetrically arranged with respect to the perpendicular line (such as l1 and l2 are symmetric with respect to l).

[0092] It is understandable that in the first embodiment and the second embodiment described above, a plurality of the first trajectories all adopt a straight-line scanning method. In other embodiments, a plurality of the first trajectories may also adopt an arc scanning method for scanning. Regardless of the scanning method, the method for regularizing the step scanning trajectory (the second trajectory) between two adjacent first trajectories is the same as that in the first embodiment or the second embodiment, and the present invention will not describe it in detail herein.

[0093] To facilitate an intuitive introduction of the technical effects achievable by the first embodiment and the second embodiment of the present invention, the following compares the total annealing time of the wafers corresponding to the annealing scanning path in the prior art shown in Figure 1 and the optimized annealing scanning path provided in the embodiments of the present invention shown in Figures 5 - 7 through simulation results.

[0094] Combined with Figure 1 , assuming that the wafer has a size of 8 inches and a diameter of 203.2 mm, using the annealing scanning path regularization method shown in Figure 1 , the corresponding total scanning length is L1, the spacing d between two adjacent first trajectories (two adjacent scanning trajectories) is 2.5 mm, and the scanning speed is 400 mm / s. Based on this, through Matlab simulation, it can be obtained that L1 = 14051.17 mm, and the total required time is approximately t1 = 52.27 s.

[0095] Combined with Figure 5 or Figure 6 , assuming that the wafer has a size of 8 inches and a diameter of 203.2 mm, using the optimized annealing scanning path regularization method shown in Figure 4 , the corresponding total scanning length is L1, the spacing d between two adjacent first trajectories (two adjacent scanning trajectories) is 2.5 mm, and the scanning speed is 400 mm / s. Based on this, through Matlab simulation, it can be obtained that L1 = 13565.33 mm, and the total required time is approximately t1 = 34.12 s.

[0096] Combined with Figure 7 , assuming that the wafer has a size of 8 inches and a diameter of 203.2 mm, using the annealing scanning path regularization method shown in Figure 6 , the corresponding total scanning length is L1, the spacing d between two adjacent first trajectories (two adjacent scanning trajectories) is 2.5 mm, and the scanning speed is 400 mm / s. Based on this, through Matlab simulation, it can be obtained that L1 = 13331.75 mm, and the total required time is approximately t1 = 33.52 s.

[0097] Obviously, for the annealing scan using the optimized annealing scan path provided in the embodiments of the present invention, its total scan length is reduced and the total scan time is decreased.

[0098] In addition, based on the laser annealing method described above, an embodiment of the present invention may further provide a photolithography method, which at least includes the steps of the laser annealing method described above, and the present invention will not repeat it here.

[0099] In summary, in the laser annealing method provided by the present invention, the second trajectory (stepping trajectory) between adjacent first trajectories (adjacent scan trajectories) is optimized into at least one curved trajectory, and the second trajectory is tangent to each of the adjacent first trajectories. The unexpected effect is that by optimizing the stepping trajectory between adjacent scan trajectories into an arc trajectory tangent to them, the laser can continuously emit light during the stepping scan process, solving the problems in the prior art that in order to avoid damage to other components of the worktable during the stepping scan process, the laser needs to be turned off multiple times, resulting in unstable laser energy and large differences in annealing uniformity between the edge and the middle part of the wafer, that is, improving the annealing uniformity of the wafer.

[0100] Moreover, by optimizing the stepping trajectory between adjacent scan trajectories into a curved trajectory tangent to them, it can further ensure that the stepping scan process is also a uniform motion process, that is, there is no need to experience the process in the prior art where the worktable needs to decelerate to a stop along a straight line and then accelerate and decelerate along a straight line to complete the stepping scan due to multiple broken lines for the stepping scan from the previous scan trajectory to the next scan trajectory, reducing the scan time required for the stepping trajectory, thereby reducing the total annealing time of the wafer and improving the production rate of the wafer.

[0101] An embodiment of the present invention also provides an electronic device, including a processor, a communication interface, a memory, and a communication bus. Among them, the processor, the communication interface, and the memory complete communication with each other through the communication bus.

[0102] The memory is used to store a computer program.

[0103] The processor is used to implement a laser annealing method or a photolithography method provided by an embodiment of the present invention when executing the program stored in the memory.

[0104] In addition, the implementation steps of the laser annealing method or the photolithography method implemented by the processor when executing the program stored in the memory will not be elaborated here either.

[0105] The communication bus mentioned in the above control terminal may be a Peripheral Component Interconnect (PCI) bus, an Extended Industry Standard Architecture (EISA) bus, or the like. This communication bus can be divided into an address bus, a data bus, a control bus, etc. For the sake of simplicity, only a thick line is used to represent it in the figure, but it does not mean that there is only one bus or one type of bus.

[0106] The communication interface is used for communication between the above electronic device and other devices.

[0107] The memory may include a Random Access Memory (RAM), or may also include a Non-Volatile Memory (NVM), such as at least one disk memory. Optionally, the memory may also be at least one storage device located far from the aforementioned processor.

[0108] The above-mentioned processor may be a general-purpose processor, including a Central Processing Unit (CPU), a Network Processor (NP), etc.; it may also be a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field-Programmable Gate Array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components.

[0109] In another embodiment provided by the present invention, there is also provided a computer-readable storage medium, in which instructions are stored. When it runs on a computer, it causes the computer to execute any one of the laser annealing methods or lithography methods described in the above embodiments.

[0110] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the processes or functions described in the embodiments of the present invention are generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center by wire (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or data center that includes one or more integrated available media. The available medium can be a magnetic medium (such as a floppy disk, hard disk, magnetic tape), an optical medium (such as a DVD), or a semiconductor medium (such as a solid-state drive (SSD)).

[0111] It should be noted that in this document, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including", or any other variation thereof is intended to cover non-exclusive inclusion, such that a process, method, article, or device that includes a series of elements includes not only those elements but also other elements that are not explicitly listed, or also includes elements that are inherent to such process, method, article, or device. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of additional identical elements in the process, method, article, or device that includes the element.

[0112] Each embodiment in this specification is described in a related manner. For the same or similar parts among the embodiments, reference can be made to each other. Each embodiment focuses on the differences from other embodiments. In particular, for the embodiments of the apparatus, electronic device, and computer-readable storage medium, since they are basically similar to the method embodiments, the description is relatively simple, and reference can be made to the corresponding parts of the method embodiments for the relevant content.

[0113] The above are only the preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention are all included within the protection scope of the present invention.

Claims

1. A laser annealing method, characterized in that, Including: Providing a laser unit; Providing a wafer; Relatively moving the laser unit and the wafer to complete annealing of the wafer; Wherein, relatively moving the laser unit and the wafer includes irradiating a first trajectory of the wafer and a plurality of second trajectories connecting adjacent first trajectories with the laser emitted by the laser unit, and at least one section of the second trajectories is a curved trajectory.

2. The laser annealing method according to claim 1, characterized in that, The second trajectory connecting the i-th and the (i + 1)-th first trajectories is tangent to the i-th first trajectory at its starting position and tangent to the (i + 1)-th first trajectory at the terminating position of the second trajectory, where i ≥ 1.

3. The laser annealing method according to claim 2, characterized in that The shape of the curved trajectory includes at least one of: arc-shaped, exponential function curve-shaped, and trigonometric function curve-shaped.

4. The laser annealing method according to claim 3, wherein The second trajectory is composed of at least one first curved trajectory and at least one straight trajectory tangent thereto.

5. The laser annealing method according to claim 3, characterized in that, The second trajectory is composed of at least one second curved trajectory and at least one third curved trajectory tangent thereto.

6. The laser annealing method according to claim 4, wherein, The second trajectory connecting the i-th and the (i + 1)-th first trajectories is tangent to the i-th first trajectory at its starting position and tangent to the (i + 1)-th first trajectory at the terminating position of the second trajectory, including: The terminating position of the i-th first trajectory is on the same horizontal line as the first straight trajectory, the terminating position of the first straight trajectory coincides with the starting position of the first curved trajectory, and the terminating position of the first curved trajectory coincides with the starting position of the (i + 1)-th first trajectory.

7. The laser annealing method according to claim 5, wherein The second trajectory connecting the i-th and the (i + 1)-th first trajectories is tangent to the i-th first trajectory at its starting position and tangent to the (i + 1)-th first trajectory at the terminating position of the second trajectory, including: The terminating position of the i-th first trajectory coincides with the starting position of the second curved trajectory, the terminating position of the second curved trajectory coincides with the starting position of the third curved trajectory, and the terminating position of the third curved trajectory coincides with the starting position of the (i + 1)-th first trajectory.

8. The laser annealing method according to claim 7, characterized in that, The extension line of the line connecting the center of the second curved trajectory to the center of the third curved trajectory passes through the terminating position of the second curved trajectory and the starting position of the third curved trajectory that coincides with the terminating position.

9. The laser annealing method according to claim 1, characterized in that, When relatively moving the laser unit and the wafer, the energy of the laser unit when emitting laser to form the first trajectory is the same as the energy when forming the second trajectory.

10. The laser annealing method according to claim 1, wherein When relatively moving the laser unit and the wafer, the scanning speed of the first trajectory is the same as the stepping speed of the second trajectory.

11. The laser annealing method according to claim 10, wherein, When relatively moving the laser unit and the wafer, the relative movement is a uniform motion.

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