A light spot appearance measuring device, measuring method and laser annealing apparatus

Abstract

The embodiment of the present application discloses a kind of light spot topography measuring device, measuring method and laser annealing equipment.Therein including: workpiece table and light spot topography measuring unit;Light spot topography measuring unit is used to divide the light spot on silicon wafer into multiple energy distribution zones in first direction, wherein, first direction is any direction in the plane where silicon wafer is located;It is also used to sequentially collect radiant energy in different energy distribution zones with different acquisition times according to the position of energy distribution zone in light spot, wherein, the acquisition time corresponding to the energy distribution zone closer to the edge of light spot is longer;It is also used to form the energy distribution diagram of light spot according to the radiant energy in different energy distribution zones, and obtain the topography of light spot.The embodiment of the present application can solve the problem that the measurement of light spot edge area is easy to be distorted in the existing laser light spot measurement technology, ensure the accuracy of laser light spot acquisition, improve the detection precision of light spot topography, avoid the occurrence of distortion.

Description

Technical Field

[0001] This invention relates to the field of laser equipment technology, and in particular to a spot morphology measuring device, measuring method, and laser annealing equipment. Background Technology

[0002] Existing laser spot contour measurement methods are separated from the actual laser annealing process. During laser spot focal plane detection, because the workpiece is not positioned at the camera's focal plane, the optimal focal plane of the laser during measurement cannot be transferred to the actual annealed silicon wafer surface. This leads to a deviation between the spot morphology obtained during the actual annealing process and the measured spot morphology, reducing detection accuracy. Simultaneously, because the CO2 laser spot is a Gaussian spot, the light intensity varies at different locations within its entire static spot range. Therefore, when the same energy is applied to the silicon wafer, the thermal radiation energy is not uniformly distributed; the radiation energy at the spot edges is lower, causing distortion in the acquired spot shape and similarly reducing the detection accuracy. Summary of the Invention

[0003] This invention provides a spot morphology measurement device, measurement method, and laser annealing equipment to calibrate the positions of the camera and the workpiece, while improving the accuracy of spot morphology detection by utilizing spot zonal detection.

[0004] In a first aspect, embodiments of the present invention provide a light spot morphology measuring device, comprising:

[0005] A workpiece stage is used to hold a silicon wafer on which light spots can be formed by illumination.

[0006] A light spot morphology measurement unit is used to divide the light spot on the silicon wafer into multiple energy distribution regions in a first direction, wherein the first direction is any direction in the plane where the silicon wafer is located; it is also used to collect the radiation energy in different energy distribution regions at different collection times according to the position of the energy distribution regions in the light spot, wherein the collection time corresponding to the energy distribution region closer to the edge of the light spot is longer; it is also used to stitch together the radiation energy in different energy distribution regions to form an energy distribution map of the light spot, thereby obtaining the morphology of the light spot.

[0007] Optionally, the spot morphology measurement unit includes a time-delay integration camera, which includes multiple exposure levels; the time-delay integration camera is used to collect radiation energy in different energy distribution areas according to the position of the energy distribution area in the spot, with different exposure levels corresponding to the energy distribution area closer to the edge of the spot.

[0008] Optionally, the spot morphology measurement unit further includes a linear array imaging linear scanning lens; the linear array imaging linear scanning lens is used to scan along the first direction to sequentially image different positions of the spot onto multiple linear arrays arranged along the first direction by the time-delay integration camera.

[0009] Optionally, the linear array imaging line scan lens is further configured to calculate the scanning speed corresponding to the current energy distribution area based on the length of the light spot in the first direction, the length of the linear array in the time-delay integration camera, and the exposure level corresponding to the current energy distribution area, and to expose and collect radiation energy in the current energy distribution area at the scanning speed.

[0010] Optionally, the spot morphology measurement unit further includes an illumination source for illuminating the silicon wafer; the time-delay integration camera is used to acquire images of the silicon wafer at different heights before sequentially acquiring radiation energy in different energy distribution areas at different acquisition times according to the positions of the energy distribution areas in the spot, so as to determine the location of the silicon wafer at the focal plane of the linear array imaging lens by the alignment marks on the silicon wafer.

[0011] Optionally, the spot morphology measurement unit further includes a semi-transparent mirror, a first reflecting mirror, a second reflecting mirror, and a measurement stage;

[0012] The time-delay integration camera, the linear array imaging lens, the semi-transparent mirror, the first mirror, and the second mirror are all mounted on the measuring platform, which can move in a direction perpendicular to the workpiece stage.

[0013] The first reflector, the semi-transparent mirror, and the linear array imaging camera are sequentially located on the outgoing light path of the illumination source, while the linear array imaging camera, the semi-transparent mirror, the second reflector, and the time-delay integration camera are sequentially located on the reflected light path of the silicon wafer.

[0014] Optionally, the exposure levels of the energy distribution area follow a geometric or arithmetic progression from the center to the edge of the light spot.

[0015] Optionally, the light spot is oval in shape, and the first direction is a direction perpendicular to the extension of the oval shape;

[0016] The spot morphology measurement unit is used to divide the spot on the silicon wafer into multiple energy distribution regions in a first direction, and the multiple energy distribution regions are symmetrically distributed relative to the center line of the oval shape.

[0017] Along the direction from the center line to the edge, the exposure levels corresponding to the multiple energy distribution zones are in a geometric sequence.

[0018] Optionally, it also includes a crossbeam and a vertical measurement unit; the spot morphology measurement unit is disposed on the crossbeam and can move along a direction perpendicular to the first direction; the vertical measurement unit is used to measure the height between the measurement stage and the silicon wafer.

[0019] Optionally, the workpiece stage includes a motion stage and a suction cup fixed on the motion stage; the motion stage can move in a horizontal direction, and the suction cup is used to adsorb and fix the silicon wafer.

[0020] Secondly, embodiments of the present invention also provide a laser annealing apparatus, including a spot morphology measuring device as described in any of the first aspects.

[0021] Thirdly, embodiments of the present invention also provide a method for measuring light spot morphology, including:

[0022] The light spot on the silicon wafer is divided into multiple energy distribution regions in a first direction, wherein the first direction is any direction in the plane where the silicon wafer is located;

[0023] According to the position of the energy distribution area in the light spot, the radiation energy in different energy distribution areas is collected sequentially at different collection times, wherein the collection time is longer for the energy distribution area that is closer to the edge of the light spot;

[0024] The energy distribution map of the light spot is formed by splicing together the radiation energy in different energy distribution areas to obtain the morphology of the light spot.

[0025] Optionally, according to the position of the energy distribution area in the light spot, the radiant energy in different energy distribution areas is collected sequentially at different collection times, including:

[0026] Using a time-delay integration camera, the radiation energy in different energy distribution areas is collected sequentially at different exposure levels according to the position of the energy distribution area in the light spot. The energy distribution area closer to the edge of the light spot corresponds to more exposure levels.

[0027] Optionally, the exposure levels of the energy distribution area follow a geometric or arithmetic progression from the center to the edge of the light spot.

[0028] Optionally, a time-delay integration camera is used to sequentially collect radiant energy in different energy distribution areas at different exposure levels according to the position of the energy distribution area in the light spot, including:

[0029] Based on the length of the light spot in the first direction, the length of the linear array in the time-delay integration camera, the length of the current energy distribution area in the first direction, and the exposure level corresponding to the current energy distribution area, the scanning speed corresponding to the current energy distribution area is calculated sequentially.

[0030] A linear array imaging line scan lens is used to scan the current energy distribution area along the first direction at the scanning speed, so that the time-delay integration camera can sequentially expose and collect radiation energy from different energy distribution areas.

[0031] Optionally, before sequentially acquiring radiant energy in different energy distribution regions at different acquisition times according to their positions within the light spot, the method further includes:

[0032] The silicon wafer is illuminated at different heights and images of the silicon wafer are acquired to determine the location of the silicon wafer at the focal plane of the linear array imaging lens by means of alignment marks on the silicon wafer.

[0033] In this embodiment of the invention, a workpiece stage and a spot morphology measurement unit are set in the spot morphology measurement device. The workpiece stage is used to support a silicon wafer, on which a spot can be irradiated to form a laser beam. The spot morphology measurement unit divides the spot on the silicon wafer into multiple energy distribution regions in a first direction. According to the position of the energy distribution region in the spot, the radiation energy in different energy distribution regions is collected sequentially at different collection times. The collection time corresponding to the energy distribution region closer to the edge of the spot is longer. Based on the radiation energy in different energy distribution regions, an energy distribution map of the spot is formed to obtain the morphology of the spot. This realizes the direct measurement of the laser spot of the silicon wafer during annealing on the workpiece stage. Moreover, the method of regional measurement can collect energy according to the energy level of different energy distribution regions. This invention addresses the problem that existing laser spot measurement techniques cannot convert the focal plane during measurement to the actual surface of the annealed silicon wafer. It also solves the problem of measurement distortion in the edge region of the laser spot. This ensures that the laser spot used during measurement is actually applied to the laser annealing process, preventing deviations between the actual annealing spot morphology and the measured spot morphology. Furthermore, it employs a more accurate acquisition method for the energy levels at different locations of the laser spot, precisely obtaining the energy distribution at these locations, ensuring the accuracy of laser spot acquisition, improving the detection precision of the spot morphology, and avoiding distortion. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the structure of a spot morphology measuring device provided in an embodiment of the present invention;

[0035] Figure 2yes Figure 1 A schematic diagram of the morphology and partitioning of the light spot in the light spot morphology measurement device shown;

[0036] Figure 3 This is a flowchart of a spot morphology measurement method provided in an embodiment of the present invention;

[0037] Figure 4 This is a schematic diagram of another spot morphology measuring device provided in an embodiment of the present invention;

[0038] Figure 5 yes Figure 4 A schematic diagram of the spot morphology measurement unit in the spot morphology measurement device shown;

[0039] Figure 6 This is a schematic diagram of the structure of a time-delay integration camera provided in an embodiment of the present invention;

[0040] Figure 7 This is a schematic diagram of the exposure levels of a light spot energy distribution area provided in an embodiment of the present invention. Detailed Implementation

[0041] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0042] Figure 1 This is a schematic diagram of the structure of a spot morphology measuring device provided in an embodiment of the present invention. Figure 2 yes Figure 1 The diagram shows the morphology and partitioning of the light spot in the light spot morphology measurement device. (Refer to...) Figure 1 and Figure 2 The light spot morphology measuring device includes: a workpiece stage 10 for supporting a silicon wafer 100, on which a light spot 11 can be formed by irradiation; a light spot morphology measuring unit 20 for dividing the light spot 11 on the silicon wafer 100 into multiple energy distribution regions 110 in a first direction 1, wherein the first direction 1 is any direction in the plane where the silicon wafer 100 is located; it is also used to collect the radiation energy in different energy distribution regions 110 sequentially at different collection times according to the position of the energy distribution regions 110 in the light spot 11, wherein the collection time corresponding to the energy distribution region 110 closer to the edge of the light spot 11 is longer; and it is also used to stitch together the radiation energy in different energy distribution regions 110 to form an energy distribution map of the light spot 11, thereby obtaining the morphology of the light spot 11.

[0043] The workpiece stage 10 is a platform used for laser annealing of the silicon wafer 100. In this embodiment, the silicon wafer 100 is placed on the workpiece stage 10 to perform morphological detection of the laser spot used in the actual annealing process. The laser spot morphology measurement unit 20 is responsible for measuring the morphology of the laser spot formed on the silicon wafer 100 by irradiation. It can be understood that in this embodiment, the thermal radiation generated by the laser spot 11 on the silicon wafer 100 is actually utilized. The laser spot morphology measurement unit 20 performs thermal radiation image acquisition and determines the laser spot morphology features, including the contour, based on the thermal radiation energy distribution of the laser spot 11.

[0044] The measurement process of the spot morphology measurement unit in this spot morphology measurement device is described below. First, Figure 3 This is a flowchart of a spot morphology measurement method provided in an embodiment of the present invention. This spot morphology measurement method is executed by the aforementioned spot morphology measurement unit. Specifically, refer to... Figures 1-3 The method for measuring the morphology of the light spot may include:

[0045] S110. Divide the light spot on the silicon wafer into multiple energy distribution regions in a first direction, wherein the first direction is any direction in the plane where the silicon wafer is located.

[0046] In this step, the spot morphology measurement unit 20 can determine the spot location by analyzing the energy distribution in the initially acquired silicon wafer image. Image processing can then divide the spot 11 into multiple energy distribution regions 110. It should be noted that this step does not involve dividing the spot in the initially acquired image into regions, but rather dividing the region on the silicon wafer 100 where the spot is located. This region division is actually to provide a basis for subsequent zonal energy acquisition. It can be understood that this division process is merely a virtual data processing procedure used to guide subsequent acquisition processes according to regions.

[0047] S120. According to the position of the energy distribution area in the light spot, the radiation energy in different energy distribution areas is collected in sequence at different collection times. The collection time is longer for the energy distribution area that is closer to the edge of the light spot.

[0048] This step is the main step in the morphology measurement of the laser spot morphology unit 20. Based on the partitioning of the laser spot, adaptive image acquisition is performed on the energy distribution areas 110 at different locations. For example, by changing the acquisition time, accurate energy values ​​can be obtained based on the magnitude of the radiation energy in different energy distribution areas 110. It can be understood that the laser spot is usually a Gaussian spot, that is, the energy distribution in the middle area is higher and the energy value is higher, while the energy distribution in the edge area is lower and the energy value is lower. Setting the energy distribution area 110 closer to the edge of the laser spot to use a relatively longer acquisition time for energy acquisition can ensure that the energy distribution area 110 at the edge has more acquisition samples, improve the accuracy of energy acquisition, avoid the influence of noise, and prevent random errors. At the same time, it can also ensure that the energy distribution area 110 in the middle of the laser spot can have its energy acquisition process appropriately reduced, so as to avoid the energy in the middle energy distribution area 110 being too high, which would affect the sensor acquisition quality and also help improve the accuracy of energy acquisition.

[0049] S130. Based on the radiation energy in different energy distribution areas, splice together the energy distribution map of the light spot to obtain the morphology of the light spot.

[0050] This step requires normalizing the radiant energy in each energy distribution region 110. By using the relative energy distributions in each region 110, a light spot is formed by piecing them together, thus obtaining the morphology of the light spot. This normalization process can be understood as the ratio of the radiant energy in each energy distribution region 110 to the radiant energy in the intermediate region or the region corresponding to the maximum energy value, and this ratio is used as the relative energy value of each energy distribution region 110. It is understood that the absolute energy of the laser spot depends on the emission power of the laser beam. In this embodiment, the morphology of the light spot 11 is characterized by the relative energy in each energy distribution region 110, which is applicable to laser annealing at various power levels.

[0051] In this embodiment of the invention, a workpiece stage and a spot morphology measurement unit are set in the spot morphology measurement device. The workpiece stage is used to support a silicon wafer, on which a spot can be irradiated to form a laser beam. The spot morphology measurement unit divides the spot on the silicon wafer into multiple energy distribution regions in a first direction. According to the position of the energy distribution region in the spot, the radiation energy in different energy distribution regions is collected sequentially at different collection times. The collection time corresponding to the energy distribution region closer to the edge of the spot is longer. Based on the radiation energy in different energy distribution regions, an energy distribution map of the spot is formed to obtain the morphology of the spot. This realizes the direct measurement of the laser spot of the silicon wafer during annealing on the workpiece stage. Moreover, the method of regional measurement can collect energy according to the energy level of different energy distribution regions. This invention addresses the problem that existing laser spot measurement techniques cannot convert the focal plane during measurement to the actual surface of the annealed silicon wafer. It also solves the problem of measurement distortion in the edge region of the laser spot. This ensures that the laser spot used during measurement is actually applied to the laser annealing process, preventing deviations between the actual annealing spot morphology and the measured spot morphology. Furthermore, it employs a more accurate acquisition method for the energy levels at different locations of the laser spot, precisely obtaining the energy distribution at these locations, ensuring the accuracy of laser spot acquisition, improving the detection precision of the spot morphology, and avoiding distortion.

[0052] Figure 4 This is a schematic diagram of another spot morphology measuring device provided in an embodiment of the present invention, for reference. Figure 4 In one specific embodiment, the workpiece stage 10 includes a motion stage 101 and a suction cup 102 fixed on the motion stage 101. The motion stage 101 can move horizontally, and the suction cup 102 is used to adsorb and fix the silicon wafer 100. The motion stage 101 has two motion components in the X and Y directions on the horizontal plane, which intersect but can be designed to be perpendicular to each other. Thus, by moving the motion stage 101 in the X and Y directions, the silicon wafer 100 adsorbed and fixed on it by the suction cup 102 can be adjusted to any position on the horizontal plane.

[0053] Figure 5 yes Figure 4 The schematic diagram of the spot morphology measurement unit in the spot morphology measurement device shown is for reference. Figure 4 and Figure 5In one specific embodiment, the spot morphology measurement unit 20 may include a time-delay integration camera 21, a linear array imaging lens 22, and an illumination source 23. The time-delay integration camera 21 may have multiple stages. Furthermore, it may include a semi-transparent mirror 24, a first reflector 251, a second reflector 252, and a measurement stage 26. The time-delay integration camera 21, the linear array imaging lens 22, the semi-transparent mirror 24, the first reflector 251, and the second reflector 252 are all mounted on the measurement stage 26, which can move along a direction perpendicular to the workpiece stage 10. The first reflector 251, the semi-transparent mirror 24, and the linear array imaging lens 22 are sequentially located on the output light path of the illumination source 23, and the linear array imaging lens 22, the semi-transparent mirror 24, the second reflector 252, and the time-delay integration camera 21 are sequentially located on the reflected light path of the silicon wafer 100.

[0054] In one specific embodiment, the spot morphology measuring device further includes a crossbeam 30 and a vertical measuring unit 40; the spot morphology measuring unit 20 is disposed on the crossbeam 30 and can move along the vertical first direction 1; the vertical measuring unit 40 is used to measure the height between the measuring stage 26 and the silicon wafer 100.

[0055] The direction perpendicular to the workpiece stage 10 is the z-axis direction, and the crossbeam 30 can be set to extend along the X-axis. In this case, the spot morphology measurement unit 20 mounted on the crossbeam 30 can be adjusted in the X-axis position by moving the crossbeam 30 laterally, or the spot morphology measurement unit 20 can be fixedly mounted on the crossbeam 30. By moving the motion stage 101 on the horizontal plane, the silicon wafer 100 and the spot 11 formed on it can be adjusted to be within the field of view of the spot morphology measurement unit 20. The vertical measurement unit 40 can be used to detect the relative distance between the spot morphology measurement unit 20 and the workpiece stage 10 in the Z-axis, calibrate the optimal focal plane position of the spot morphology measurement unit 20 during the measurement process, and then apply this optimal focal plane position to the subsequent annealing process.

[0056] Regarding the working principle of the internal components of the spot morphology measurement unit 20, firstly, the illumination source 23 is used to illuminate the workpiece stage 10. The illumination beam emitted from the illumination source 23 passes through the first reflecting mirror 251, the semi-transparent mirror 24, and the linear array imaging scanning lens 22. The silicon wafer 100 reflects the illumination beam, which then passes through the linear array imaging scanning lens 22 and the second reflecting mirror 252 and is incident on the time-delay integration camera 21. The time-delay integration camera 21 can then acquire an image of the silicon wafer 100. This illumination stage is mainly used to determine the field of view and is a preliminary acquisition stage. In this stage, the relative positions of the spot morphology measurement unit 20 and the silicon wafer 100 or the spot 11 can be adjusted so that the silicon wafer 100 or the spot 11 is located within the field of view of the spot morphology measurement unit 20. During the partitioned image acquisition stage, the linear array imaging lens 22 is used to adjust the imaging position of the light spot 11. Specifically, the light spot 11 is imaged on different positions of the same energy distribution area 110 on the time-delay integration camera 21. In other words, by deflecting the linear array imaging lens 22, the same energy distribution area 110 can be scanned at different positions of the time-delay integration camera 21. At this time, the linear array on the time-delay integration camera 21, arranged according to the scanning direction, can sequentially acquire the radiation energy of the energy distribution area 110, thereby realizing the image acquisition of the energy distribution area 110.

[0057] The functions of the above structures and their corresponding steps in the measurement method are described in detail below. First, the time-delay integration camera 21 is used to collect the radiation energy in different energy distribution areas 110 according to their positions in the light spot 11, with different exposure levels. The closer the energy distribution area 110 is to the edge of the light spot 11, the more exposure levels it corresponds to.

[0058] Figure 6 This is a schematic diagram of the structure of a time-delay integration camera provided in an embodiment of the present invention, with reference to... Figure 6Specifically, the time-delay integration camera 21 is a camera with an area array structure and linear array output. It includes multiple levels, meaning it has multiple sequentially arranged linear arrays. A certain number of these linear arrays can be selected to acquire images of the same energy distribution area 110, thus realizing the time-delay integration function. This allows the image acquisition time of different energy distribution areas 110 to vary depending on the number of linear arrays acquired. It can be understood that the multi-level exposure of the time-delay integration camera requires the cooperation of the aforementioned linear array imaging line scan lens 22. The exposure process is the process by which the linear array imaging line scan lens 22 images the energy distribution area 110 onto a certain linear array of the time-delay integration camera. Multi-level exposure means that the linear array imaging line scan lens 22 sequentially images the same energy distribution area 110 onto multiple linear arrays through scanning. The time-delay integration camera 21 accumulates the signal. As the number of exposure levels increases, the signal increases linearly with the number of exposure levels (N), while the noise increases square root-likely with the number of exposure levels. This increases the signal-to-noise ratio (SNR) of the time-delay integration camera by a factor of N, thereby achieving high sensitivity and SNR. Furthermore, as mentioned above, the multi-level exposure of the time-delay integration camera requires the cooperation of the aforementioned linear array imaging lens. Therefore, specifically, the linear array imaging lens 22 is used to scan along the first direction 1 to sequentially image different positions of the light spot 11 onto multiple linear arrays arranged along the first direction 1 in the time-delay integration camera 21.

[0059] In the above-mentioned spot morphology measurement method, step S120, according to the position of the energy distribution area in the spot, sequentially collects the radiation energy in different energy distribution areas at different collection times, may include: S121, using a time-delay integration camera, sequentially collecting the radiation energy in different energy distribution areas at different exposure levels according to the position of the energy distribution area in the spot, wherein the energy distribution area closer to the edge of the spot corresponds to more exposure levels.

[0060] This step determines the exposure levels of the time-delay integration camera based on the position of the energy distribution area 110 within the light spot 11, essentially designing it according to the energy distribution characteristics of the light spot 11. Specifically, the energy distribution area 110 at the edge has less energy, and the closer to the edge, the less energy there is. When acquiring energy in this area, signal interference and other issues can easily lead to measurement errors. Therefore, setting more exposure levels for the energy distribution area 110 closer to the edge can appropriately increase the energy acquisition time in the edge region. Using the time-delay integration camera can reduce the signal-to-noise ratio and obtain accurate energy distribution data.

[0061] In an optional embodiment, the exposure levels of the energy distribution area 110 can be set to follow a geometric or arithmetic sequence from the center to the edge of the light spot 11. It is understood that the energy distribution of the light spot 11 generally decreases exponentially from the center to the edge. By using a geometric or arithmetic sequence to set the exposure levels of different energy distribution areas 110, energy harvesting can be adapted to each energy distribution area.

[0062] In addition, continue to refer to Figure 1 and Figure 2 In one specific embodiment, the light spot 11 can be set in the shape of an oval, and the first direction 1 is the direction perpendicular to the extension of the oval; the light spot morphology measurement unit 20 is used to divide the light spot 11 on the silicon wafer 100 into multiple energy distribution regions 110 in the first direction 1, and the multiple energy distribution regions 110 are symmetrically distributed relative to the center line of the oval; along the direction from the center line to the edge, the exposure levels corresponding to the multiple energy distribution regions 110 are in a geometric sequence.

[0063] Figure 7 This is a schematic diagram of the exposure levels of a light spot energy distribution area provided in an embodiment of the present invention, for reference. Figure 2 and Figure 7 The following is a specific example, in which the light spot 11 on the silicon wafer 100 can be divided into eight energy distribution areas 110 in the first direction 1. The eight energy distribution areas 110 are symmetrically distributed relative to the center line of the oval shape. Along the direction from the center line to the edge, the exposure levels corresponding to the four energy distribution areas 110 are 32, 64, 128 and 256 levels, respectively.

[0064] During the scanning imaging process of the linear array imaging line scan lens and the time-delay integration camera, since different energy distribution areas correspond to different exposure levels of the time-delay integration camera, the scanning speed of the linear array imaging line scan lens needs to be predetermined when switching to acquire different energy distribution areas. Therefore, the linear array imaging line scan lens 22 is also used to calculate the scanning speed v of the linear array imaging line scan lens 22 based on the length L2 of the linear array 210 in the time-delay integration camera 21, the sampling frequency F of the time-delay integration camera 21, and the highest exposure level N, i.e., v = L2 * F / N, and to expose and acquire radiation energy of the current energy distribution area 110 at this scanning speed v. Specifically, the scanning speed of the linear array imaging line scan lens 22 is fixed when acquiring each energy distribution area 110, and different contrasts are obtained by targeting the exposure level (N, N / 2, N / 4…) corresponding to the current energy distribution area 110.

[0065] Specifically, in the above-mentioned spot morphology measurement method, S121, using a time-delay integration camera, according to the position of the energy distribution area in the spot, sequentially collects the radiation energy in different energy distribution areas at different exposure levels, which may include:

[0066] S1211. Calculate the scanning speed of the linear array imaging lens based on the length of the linear array in the time-delay integration camera, the sampling frequency of the time-delay integration camera, and the highest exposure level.

[0067] S1212: A linear array imaging scanning lens is used to scan the current energy distribution area along the first direction at a scanning speed, so as to expose and collect radiation energy in different energy distribution areas in sequence through a time-delay integration camera.

[0068] Based on the length L2 of the linear array and the maximum exposure level N of the time-delay integration camera, the scanning length of the linear array imaging line scan lens can be determined. Given the sampling frequency of the time-delay integration camera, the scanning speed v of the linear array imaging line scan lens can be determined. Thus, according to the exposure level corresponding to the currently acquired energy distribution area, the multi-level exposure process of the time-delay integration camera can be matched to obtain different contrasts.

[0069] Continuing, as described above, the illumination source 23 is used to illuminate the silicon wafer 100. Meanwhile, the time-delay integration camera 21 is used to acquire images of the silicon wafer 100 at different heights before acquiring the radiation energy in different energy distribution areas 110 at different acquisition times according to the position of the energy distribution area 110 in the light spot 11, so as to determine that the silicon wafer 100 is located at the focal plane of the linear array imaging linear scanning lens 22 by the alignment marks on the silicon wafer 100.

[0070] Correspondingly, in the above-described spot measurement method, before S120, when the radiation energy in different energy distribution areas is collected sequentially at different collection times according to the position of the energy distribution area in the spot, the method further includes:

[0071] S1201. Illuminate the silicon wafer at different heights and acquire images of the silicon wafer to determine the location of the silicon wafer on the focal plane of the linear array imaging lens through alignment marks on the silicon wafer.

[0072] Here, different heights refer to different positions in the z-direction. When the distance between the time-delay integration camera 21 and the silicon wafer 100 is inappropriate, the image formed by the linear array imaging lens 22 may not be focused. By adjusting the position of the spot morphology measurement unit 20 and using the real-time imaging of the time-delay integration camera 21 for feedback adjustment, the optimal distance between the spot morphology measurement unit 20 and the silicon wafer 100 can be determined, so that the silicon wafer 100 is located at the focal plane of the linear array imaging lens 22, ensuring clear imaging in the time-delay integration camera 21.

[0073] Based on the same inventive concept, this invention also provides a laser annealing apparatus, which includes any of the spot morphology measuring devices provided in the above embodiments. Because this laser annealing apparatus employs any of the aforementioned spot morphology measuring devices, it possesses the same or similar beneficial effects as those devices.

[0074] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, combinations, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A device for measuring the morphology of a light spot, characterized in that, include: A workpiece stage is used to hold a silicon wafer on which light spots can be formed by illumination. A light spot morphology measurement unit is used to divide the light spot on the silicon wafer into multiple energy distribution regions in a first direction, wherein the first direction is any direction in the plane where the silicon wafer is located; it is also used to collect the radiation energy in different energy distribution regions at different collection times according to the position of the energy distribution regions in the light spot, wherein the collection time corresponding to the energy distribution region closer to the edge of the light spot is longer; it is also used to stitch together the radiation energy in different energy distribution regions to form an energy distribution map of the light spot, thereby obtaining the morphology of the light spot; The spot morphology measurement unit includes a time-delay integration camera, which includes multiple exposure levels. The time-delay integration camera is used to collect radiation energy in different energy distribution areas according to the position of the energy distribution area in the spot, with different exposure levels. The energy distribution area closer to the edge of the spot corresponds to more exposure levels. The spot morphology measurement unit further includes a linear array imaging linear scanning lens; the linear array imaging linear scanning lens is used to scan along the first direction so as to sequentially image different positions of the spot onto multiple linear arrays arranged along the first direction by the time-delay integration camera; The linear array imaging line scan lens is also used to calculate the scanning speed of the linear array imaging line scan lens based on the length of the linear array in the time-delay integration camera, the sampling frequency of the time-delay integration camera, and the highest exposure level, and to expose and collect radiation energy in the current energy distribution area at the scanning speed.

2. The spot morphology measuring device according to claim 1, characterized in that, The spot morphology measurement unit further includes an illumination source for illuminating the silicon wafer; the time-delay integration camera is used to acquire images of the silicon wafer at different heights before acquiring radiation energy in different energy distribution areas at different acquisition times according to the positions of the energy distribution areas in the spot, so as to determine the location of the silicon wafer at the focal plane of the linear array imaging lens by the alignment marks on the silicon wafer.

3. The spot morphology measuring device according to claim 2, characterized in that, The spot morphology measurement unit also includes a semi-transparent mirror, a first reflecting mirror, a second reflecting mirror, and a measurement stage; The time-delay integration camera, the linear array imaging lens, the semi-transparent mirror, the first mirror, and the second mirror are all mounted on the measuring platform, which can move in a direction perpendicular to the workpiece stage. The first reflector, the semi-transparent mirror, and the linear array imaging camera are sequentially located on the outgoing light path of the illumination source, while the linear array imaging camera, the semi-transparent mirror, the second reflector, and the time-delay integration camera are sequentially located on the reflected light path of the silicon wafer.

4. The spot morphology measuring device according to claim 1, characterized in that, From the center of the light spot to its edge, the exposure levels of the energy distribution area follow a geometric or arithmetic progression.

5. The spot morphology measuring device according to claim 4, characterized in that, The light spot is oval in shape, and the first direction is a direction perpendicular to the extension of the oval shape; The spot morphology measurement unit is used to divide the spot on the silicon wafer into multiple energy distribution regions in a first direction, and the multiple energy distribution regions are symmetrically distributed relative to the center line of the oval shape. Along the direction from the center line to the edge, the exposure levels corresponding to the multiple energy distribution zones are in a geometric sequence.

6. The spot morphology measuring device according to claim 3, characterized in that, It also includes a crossbeam and a vertical measurement unit; the spot morphology measurement unit is disposed on the crossbeam and can move along a direction perpendicular to the first direction; the vertical measurement unit is used to measure the height between the measurement stage and the silicon wafer.

7. The spot morphology measuring device according to claim 1, characterized in that, The workpiece stage includes a motion stage and a suction cup fixed on the motion stage; the motion stage can move in a horizontal direction, and the suction cup is used to adsorb and fix the silicon wafer.

8. A laser annealing apparatus, characterized in that, Includes the light spot morphology measuring device as described in any one of claims 1-7.

9. A method for measuring the morphology of a light spot, characterized in that, include: The light spot on the silicon wafer is divided into multiple energy distribution regions in a first direction, wherein the first direction is any direction in the plane where the silicon wafer is located; According to the position of the energy distribution area in the light spot, the radiation energy in different energy distribution areas is collected sequentially at different collection times, wherein the collection time is longer for the energy distribution area that is closer to the edge of the light spot; Based on the radiant energy in different energy distribution regions, an energy distribution map of the light spot is formed by splicing the data to obtain the morphology of the light spot; According to the location of the energy distribution area in the light spot, the radiant energy in different energy distribution areas is collected sequentially at different collection times, including: Using a time-delay integration camera, the radiation energy in different energy distribution areas is collected sequentially at different exposure levels according to the position of the energy distribution area in the light spot. The energy distribution area that is closer to the edge of the light spot corresponds to more exposure levels. Using a time-delay integration camera, according to the position of the energy distribution area in the light spot, the radiant energy in different energy distribution areas is collected sequentially at different exposure levels, including: The scanning speed of the linear array imaging lens is calculated based on the length of the linear array in the time-delay integration camera, the sampling frequency of the time-delay integration camera, and the highest exposure level. A linear array imaging line scan lens is used to scan the current energy distribution area along the first direction at the scanning speed, so that the time-delay integration camera can sequentially expose and collect radiation energy from different energy distribution areas.

10. The method for measuring spot morphology according to claim 9, characterized in that, From the center of the light spot to its edge, the exposure levels of the energy distribution area follow a geometric or arithmetic progression.

11. The method for measuring the morphology of a light spot according to claim 9, characterized in that, Before sequentially collecting radiant energy from different energy distribution regions at different collection times according to their positions within the light spot, the process further includes: The silicon wafer is illuminated at different heights and images of the silicon wafer are acquired to determine the location of the silicon wafer at the focal plane of the linear array imaging lens by means of alignment marks on the silicon wafer.

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