Laser cutting system for filamentation and singulation optical devices

Abstract

A method of manufacturing an optical device is provided that includes transferring a first substrate including one or more devices to a laser cutting tool that includes a filamentation platform and a dicing platform. In the filamentation platform, one or more device profiles are created on the first substrate. In the dicing platform, the optical devices are separated from the first substrate along the one or more device profiles. The devices are transferred to storage or for further back-end processing.

Description

Technical Field

[0001] Embodiments of the present disclosure generally relate to a laser dicing system for an optical device. Background Art

[0002] In the manufacture of optical devices such as those for virtual reality or augmented reality, one or more devices having structures with sub-micron critical dimensions are disposed on a substrate for processing, e.g., on the front side of the substrate. To fabricate the optical device, the surface of the substrate on which one or more devices are disposed must be held on a substrate support assembly without contacting the one or more devices, and multiple substrates must be processed at multiple processing stations throughout the manufacturing process. Due to the number of processing stations for processing substrates and due to the maintenance of the substrates for processing, current systems for processing substrates have limitations in throughput. Once fabricated, separating the optical device from the substrate without deforming the optical device can be challenging.

[0003] Accordingly, what is needed in the art is a method for processing substrates without deforming the optical device, and a processing system for processing substrates with high throughput and without deforming the substrates. Summary of the Invention

[0004] In one embodiment, a method of manufacturing an optical device is provided. The method includes transferring a first substrate including one or more devices onto a laser dicing tool that includes a filamentation stage and a singulation stage. In the filamentation stage, one or more device contours are scribed on the first substrate. In the singulation stage, the first substrate is cut along the one or more device contours, and the devices are transferred for further processing.

[0005] In another embodiment, a system for manufacturing a device is provided. The system includes a plurality of platforms, each platform disposed under a respective optical head of a plurality of movable optical heads, and each optical head corresponding to a laser. A conveyor system is coupled to the plurality of platforms, and a sorting system includes a robot that is capable of moving devices from the conveyor system.

[0006] In yet another embodiment, a system for manufacturing a device is provided, the system including a first platform disposed below a first optical head. The first optical head is operable to direct a first laser beam from a first laser source towards the first platform. A second platform is disposed below a second optical head. The second optical head is operable to direct a second laser beam from a second laser source towards the second platform. The first platform and the second platform are operable simultaneously relative to each other. A forward conveyor system is coupled to the plurality of platforms. A vision component includes a camera disposed above the conveyor system, and a sorting system includes a robot capable of moving a device from the conveyor system. The robot is communicatively coupled to the vision component. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] In order to understand the manner in which the above-recited features of the present disclosure can be obtained in more detail, a more particular description of the disclosure briefly summarized above may be had by reference to the embodiments, some of which are illustrated in the drawings. It should be noted, however, that the drawings illustrate only exemplary embodiments and are therefore not to be considered limiting of the scope of the disclosure, and allow for other equivalent embodiments.

[0008] Figure 1 is a schematic top view of a first surface of a substrate according to one embodiment.

[0009] Figure 2 is a schematic cross-sectional view of a system including a substrate support assembly according to one embodiment.

[0010] Figure 3A and 3B are schematic top views of a substrate carrier according to some embodiments.

[0011] Figure 4 is a flow chart of a system for processing a substrate according to one embodiment.

[0012] Figure 5 is a plan view of a system for processing a substrate according to one embodiment.

[0013] Figure 6 is a schematic top view of a laser cutting assembly according to one embodiment.

[0014] For ease of understanding, where possible, the same reference numerals have been used to denote the same elements common to the figures. It is contemplated that elements and features of one embodiment may be advantageously incorporated into other embodiments without further recitation. DETAILED DESCRIPTION

[0015] Embodiments of the present disclosure generally relate to a laser cutting system for an optical device, and a method for processing an optical device. The system includes several processing stations that can operate simultaneously relative to each other. A two-part laser cutting system is included that subjects a substrate to a first laser and a second laser. The systems provided herein are capable of simultaneously processing a first substrate with a second laser while processing a second substrate with the second laser. The system is fully automated and uses a substrate carrier to easily transfer substrates from station to station. In this way, throughput and automation are increased.

[0016] Figure 1 is a perspective top view of a first surface 102 (i.e., the top surface) of substrate 100. Substrate 100 includes a second surface 104 (i.e., Figure 2 as shown) opposite the first surface 102 (i.e., Figure 2 the bottom surface visible in). Substrate 100 can be glass, plastic, silicon carbide, polycarbonate, or any other suitable material. In one embodiment, which can be combined with other embodiments described herein, substrate 100 is transparent, such as transparent glass. These materials can have rollable and flexible properties. In one embodiment, which can be combined with other embodiments described herein, substrate 100 has a thickness 116 (as Figure 2 shown) of less than about 1 millimeter (mm). In some embodiments, the thickness is less than 0.5 mm. Substrate 100 includes one or more optical devices 106 disposed on the first surface 102 and / or the second surface 104 of the substrate. The one or more optical devices 106 can include structures 114 (i.e., fins) having sub-micron critical dimensions such as critical dimensions on the order of nanometers.

[0017] Embodiments of the substrate support assembly 200 ( Figure 2 as shown) described herein are operable to hold substrate 100 having one or more optical devices 106 without contacting the structures 114 and without deforming substrate 100. Figure 2 is a schematic cross-sectional view of a system 201 including substrate support assembly 200. Substrate support assembly 200 is capable of supporting substrates 100 having different thicknesses, shapes, and sizes for laser processing.

[0018] System 201 includes one or more optical heads 205, such as a first swappable optical head. The first optical head 205 is configured to receive energy from one or more laser sources, such as a first laser from a first laser source 213. The one or more laser sources direct one or more laser beams, such as a first laser beam 209, to a second surface 104 of the substrate 100. A first surface having the optical device 106 faces away from the first laser beam 209. It has been found that facing the optical device 106 away from the first laser beam 209 can protect the structure 114 on the optical device 106 from device defects. The first laser beam 209 can be operated to heat the edge of the optical device 106 on the substrate 100 and provide an outline of the optical device. In some embodiments that can be combined with other embodiments described herein, the one or more laser sources include an infrared laser and a CO2 laser source. The laser source can be any suitable electromagnetic energy of various wavelengths, such as ultraviolet, infrared, and similar laser sources.

[0019] The substrate 100 is held on a support surface 204 of a substrate support assembly 200. In one embodiment that can be combined with other embodiments described herein, a body 202 of the substrate support assembly 200 is coupled to an actuator 211. The body 202 of the substrate support assembly 200 can be made of any suitable material, such as aluminum. The actuator 211 moves the body 202 in the x-direction, y-direction, and / or z-direction during operation. In some embodiments that can be combined with other embodiments described herein, one or more actuators 211 can be coupled to one or more platforms to move the substrate 100 disposed on the platforms. The substrate support assembly 200 includes a controller 206 that is operable to communicate with a system controller (not shown) and is operable to control various aspects of the substrate support assembly 200 during processing.

[0020] The body 202 of the substrate support assembly 200 includes a plurality of protrusions 208. In one embodiment that can be combined with other embodiments described herein, the body 202 and the protrusions 208 include a material containing stainless steel and / or aluminum. In another embodiment that can be combined with other embodiments described in this case, the body 202 and the protrusions 208 include a material containing ceramic.

[0021] A first surface 102 (i.e., the top surface) of the substrate 100 can be fixed to the support surface 204 of the plurality of protrusions 208, while one or more optical devices 106 do not contact the support surface 204. Adjacent protrusions among the plurality of protrusions 208 form pockets 214. The pockets 214 have a width 120 and a length 122 corresponding to one or more optical devices 106, as Figure 1The width 216, length, and height 222 as shown). The plurality of protrusions 208 correspond to a plurality of portions 124 of one of the first surface 102 and the second surface 104, on which one of the optical devices 106 is not provided. The recess 214 may further include one or more posts 240 that support the optical device 106 at a portion 126 of the optical device where the structure 114 is not provided. When the substrate 100 is fixed to the support surface 204 of the substrate support assembly 200, a region 220 is formed in each recess 214 between the body 202 of the substrate support assembly 200 and the optical device 106 fixed to one of the first surface 102 and the second surface 104 of the support surface 204.

[0022] Each recess 214 can be operated to be coupled to a recess conduit 224, and the recess conduit 224 is in fluid communication with a vacuum source 228 via a vacuum flow controller 226 such as an MFC. The vacuum source 228 can be operated to provide a vacuum pressure to the corresponding recess 214 through the corresponding recess conduit 224 to hold those portions of the support surface 204 of the substrate 100 corresponding to the protrusions 208 by maintaining the vacuum pressure in the corresponding region 220. In one embodiment that can be combined with other embodiments described herein, the vacuum pressure is from about 380 Torr to about 760 Torr. According to the embodiments described herein, the controller 206 can be operated to operate each vacuum flow controller 226.

[0023] Figure 3A and 3BSchematic top views of substrate carriers 302A, 302B according to some embodiments. In some embodiments, which may be combined with other embodiments described herein, substrate 100 is held on a substrate carrier, such as substrate carriers 302A, 302B. In some embodiments, which may be combined with other embodiments described herein, substrate support assembly 200 is capable of receiving a substrate held on substrate carriers 302A, 302B (such as substrate carriers 302A, 302B). Substrate carriers 302A, 302B include a base plate 304. Base plate 304 is made of a lightweight material such as a material including carbon fiber. It has been found that the lightweight material of base plate 304 enables the carrier to be easily transferred between processing stations, such as by using a pick and place robot to transfer carriers 302A, 302B. In some embodiments, which may be combined with other embodiments described herein, the base plate is about 2 kg or lighter, such as about 1.5 kg or lighter, such as about 1 kg to about 1.4 kg. Conventional base plates are greater than about 2 kg, such as greater than about 3 kg. Base plate 304 is capable of holding substrates of different shapes and sizes. Substrate carriers 302A, 302B include vacuum diaphragms 306A, 306B that approximate the shape and size of the substrate to be held. Figure 3A The vacuum diaphragm 306A shown accommodates a circular substrate having a first diameter, while Figure 3B the vacuum diaphragm 306B shown accommodates a circular substrate having a second diameter. Figure 3A The first diameter shown is less than Figure 3B the second diameter shown. Holding rings 308A, 308B, such as clamp rings, are used to hold the substrate on substrate carriers 302A, 302B. Holding rings 308A, 308B are located above substrate 100 and are capable of fixing substrate 100 using magnets disposed below substrate 100. Substrate 100 is assembled on substrate carriers 302A, 302B to provide a stack in a build station, as shown in build station 402 as shown in Figure 4 . In some embodiments, which may be combined with other embodiments described herein, the substrate carrier is capable of holding substrates having a diameter of about 100 mm to about 350 mm, such as about 150 mm, about 200 mm, or about 300 mm.

[0024] Figure 4 Is a flowchart 400 of a system for processing a substrate according to one embodiment, Figure 5 Is a plan view of a system 500 for processing a substrate according to one embodiment. Reference will be made herein to Figure 5The system shown depicts a flowchart of the system. System 500 includes a plurality of load ports 502A, 502B, 502C, 502D, such as front-opening unified pods (“FOUPs”). Substrate 100 and substrate carriers 302A, 302B are stored in separate ports until substrate 100 is ready for processing. Each load port includes a plurality of substrates 100 or a plurality of substrate carriers 302A, 302B. In some embodiments, which can be combined with other embodiments described herein, ports 502A and 502D contain substrates 100, while ports 502B and 502C contain substrate carriers 302A, 302B.

[0025] Substrate 100 and substrate carriers 302A, 302B are transferred to build station 402 for assembly. For example, the substrate from port 502A and the substrate carrier from port 502B are transferred to build station 402A. Similarly, the substrate from port 502D and the carrier from port 502C are transferred to build station 402B. In operation 410, substrate 100 is assembled onto substrate carriers 302A, 302B in build station 402. Each substrate 100 and substrate carrier 302A, 302B together form a stack. The stack is transferred from build station 402 to laser cutting assembly 404. In operation 412, the stack is aligned in preparation for cutting. This alignment operation includes: placing the stack on a platform for laser cutting. Fiducials disposed around the substrate are used as references for determining alignment. As used herein, the term “fiducial” refers to a mark disposed on the substrate that is readable to determine the alignment of the substrate. Each stack is retrieved from the build station by a robot and aligned with the Figure 2 substrate support assembly 200 as shown. The substrate 100 or stack is secured by the robot to body 202 of substrate support assembly 200 of the laser cutting tool. When laser cutting assembly 404 is in operation, robot 508 can move substrate 100 to the laser cutting tool. This synchronized operation enables high substrate throughput and efficiency.

[0026] In operation 414, the substrate 100 is patterned using a laser cutting process, which outlines the optical devices in the substrate. In operation 416, the substrate 100 is heated through these outlines while being supported by the substrate carriers 302A, 302B, thereby singulating these optical devices. Heating these outlines separates these devices from the substrate using thermal expansion. The power density of the power beam used is proportional to the size of the laser spot. The processed substrate is transferred to the back-end packaging station 406. The processed substrate is transferred using one or more forward conveyors 507. The back-end packaging station 406 includes a vision station 506 for inspecting the optical devices and a sorting station. The sorting station includes a pick-and-place robot 508 for sorting the optical devices (e.g., operation 418). The vision station 506 includes one or more cameras disposed above the processed substrate 100. The alignment is determined by capturing an image of the substrate through the one or more cameras, and the presence of defective optical devices is identified. In some embodiments, which may be combined with other embodiments described herein, the substrate is illuminated by side LED light to illuminate the edges of the optical devices for imaging. In this way, the cameras of the vision station 506 can determine the position and orientation of each optical device. The vision station 506 is communicatively coupled to the robot 508 such that the robot 508 can transfer the substrate carriers 302A, 302B without contacting the optical devices and transfer the optical devices from the substrate. The back-end packaging station 406 includes one or more forward conveyors 507, such as conveyor belts. These stacks are transferred by the forward conveyors 507 to one or more robots 508. The robot 508 is configured to remove the optical devices 106 from the stacks.

[0027] Discard defective optical devices (e.g., operation 430), and transfer non-defective optical devices to back-end packaging (e.g., operation 422). The packaged optical devices are further processed at the back-end processor, e.g., processed in an edge blackening station (e.g., operation 428). Separate the substrate 100 from which the optical device has been removed from the substrate carriers 302A, 302B (e.g., operation 420), and separate the damaged substrate 100 from the carrier (e.g., operation 432). Perform a laser cutting process on the stack described herein, which enables the substrate carriers within the stack to collect debris generated by the cutting. Remove these carriers and the debris from the substrate. The resulting optical devices with a structure facing away from the laser will be free of defects and contaminants such as particles in the debris left by the laser cutting. Multiple back-end storage ports or trays 514A, 514B, 514C, 514D are used to store the separated and sorted components, such as defective optical devices, non-defective optical devices, and different types of optical devices.

[0028] Use a vacuum module to clean the carrier at the cleaning station 510 (e.g., operation 424), and reuse the cleaned carrier for further processing (e.g., operation 426). Carriers with debris can be cleaned in-situ and collected for future use. In some embodiments that can be combined with other embodiments described herein, during a continuous loop process, place the cleaned carrier on the return conveyor 512 and return it to the loading port or build station. In some embodiments that can be combined with other embodiments described herein, the return conveyor includes a cross conveyor portion and a return portion. The return portion of the conveyor is substantially parallel to the forward conveyor. During a continuous process of multiple substrates, perform one or more of operations 410 to 432 simultaneously with each other. In some embodiments that can be combined with other embodiments described herein, process one substrate in one operation and another substrate in another operation.

[0029] Figure 6 is a schematic top view of a laser cutting assembly 404 according to one embodiment. The laser cutting assembly 404 includes two or more platforms 620, 630. The platforms 620, 630 are each capable of moving in each direction (X, Y, Z axes) and rotating about the Z axis (by, e.g., θ). Each platform includes a reference Figure 2The substrate support described above. Each platform (e.g., the first platform 620, the second platform 630) corresponds to a laser source (e.g., the first laser source 602, the second laser source 632). The first laser source 602 emits a first laser along a first beam path 604. Using one or more turning mirrors or steerers 606, 608 of the first group and one or more beam expanders 610 of the first group, the first beam path is directed to a first optical head 612. The first optical head 612 is movable along a line parallel to the X-axis and guides the first laser beam towards a first substrate disposed on the first platform for processing the first substrate. The first laser beam is from an infrared laser source or any laser capable of filamentation or cutting in the substrate. The filamentation process includes: exposing the stack to the first laser beam to heat and outline (e.g., "scribe") those edges of the optical device on the stack. The first optical head 612 is located above the second platform 630 for processing a second substrate disposed on the second platform.

[0030] Similarly, the second laser source 632 emits a second laser along a second beam path 634. Although Figure 6It is shown that the first optical head 612 and the second optical head 642 are disposed at different positions along the Y-axis and at the same position along the Z-axis. However, it is also conceivable to dispose the first optical head 612 and the second optical head 642 at the same position along the Y-axis and at different positions along the Z-axis. Optionally, the optical heads 612, 642 are located at different positions along the Z-axis and the Y-axis. It is understood that placing the optical heads 612, 642 at different positions along the z-axis enables the use of a relatively small space to process substrates simultaneously. The second laser beam is from a CO2 laser source or any laser capable of singulating an optical device from a substrate. The singulation process releases the optical device at the scratch profile created by filamentation. The first and second laser beams are selected based on the composition of the substrate, such as a glass substrate or a silicon carbide substrate. In some embodiments that can be combined with other embodiments described herein, the substrate is a silicon carbide substrate and the first laser beam source comprises a nanosecond (ns) UV laser. Each of the first laser beam and the second laser beam is selected from the group consisting of UV, green light, and IR. In particular, UV, green light, and IR lasers can be used for filamentation and / or singulation of silicon carbide or glass substrates. Additionally, CO2 lasers can be used for singulation of glass substrates. The laser source comprises a picosecond, femtosecond, or nanosecond laser source. Using one or more steering mirrors and deflectors 636, 638 of the second group and one or more beam expanders 640 of the second group, the second beam path 634 is directed to the second optical head 642. The second optical head 642 is movable along a line parallel to the X-axis and directs the second laser beam towards a first substrate disposed on the first platform 620. The second optical head 642 is located above a second substrate disposed on the second platform 630. The system enables the use of dedicated optical heads disposed above the platforms to process different substrates simultaneously relative to each other. Each optical head comprises a focusing element, a plurality of optical lenses. Although IR and CO2 lasers are described and depicted herein, any suitable laser or available cutting technique can be used to perform the filamentation and singulation processes. It has been found that filamentation and singulation reduce chipping, microcracks, delamination, and other damage that may occur in the manufacture of optical devices. The system described herein is capable of running both filamentation and singulation simultaneously, as well as utilizing other tools and operations for processing substrates, thereby allowing for high throughput.

[0031] In one embodiment that can be combined with other embodiments of the present disclosure, the first stack can be processed on the first platform 620 during the filamentation process, followed by the singulation process. When the first stack is processed during the singulation process, the second stack can be processed during the filamentation process. The first laser source 602 can transmit infrared (“IR”) energy to the first optical head 612, and the first optical head 612 can direct this energy to the stacks disposed on the second platform 630. In some embodiments that can be combined with other embodiments described herein, the first optical head is movable in a first plane, while the second optical head is movable in a second plane. The first plane and the second plane are the same or different with respect to the Z-axis.

[0032] In summary, the present disclosure generally relates to a laser cutting system for an optical device, a substrate support assembly for holding the surface of a substrate on which one or more optical devices are disposed without contacting the one or more optical devices so as to deform the substrate, and a method for processing an optical device.

[0033] Although the foregoing is directed to examples of the present disclosure, other and further examples of the present disclosure can be designed without departing from the basic scope of the present disclosure, and the scope of the present disclosure is determined by the appended claims.

Claims

1. A method of manufacturing an optical device, comprising: transferring a first substrate including a plurality of optical devices to a laser cutting tool, each of the plurality of optical devices having a contour surrounding region of a device structure, the laser cutting tool including a filamentation platform and a singulation platform; cutting the plurality of optical devices, each optical device being cut along the contour surrounding region of the device structure, the first substrate being disposed in the filamentation platform, and a protrusion of the filamentation platform contacting a portion of the plurality of optical devices between the regions of the device structure; separating the plurality of optical devices, each optical device being separated along the surrounding region of the device structure, the first substrate being disposed in the singulation platform, and a protrusion of the singulation platform contacting a portion of the plurality of optical devices between the regions of the device structure; and transferring the devices to a backend storage port or to a backend processor.

2. The method according to claim 1, further comprising: Before transferring the first substrate to the laser cutting tool, fixing the first substrate to a substrate carrier.

3. The method according to claim 2, further comprising: separating the first substrate from the substrate carrier; cleaning the substrate carrier; transferring the substrate carrier to a load port or to a build station for fixing a second substrate to the carrier; and transferring the second substrate together with the carrier to the laser cutting tool.

4. The method according to claim 1, further comprising: Inspecting the devices on the first substrate.

5. The method according to claim 4, wherein inspecting the device comprises: Taking a top view image of the first substrate.

6. The method according to claim 5, further comprising: Separating defective devices from good devices.

7. The method according to claim 1, further comprising: Cutting a third substrate on the filamentation platform, wherein while cutting the third substrate, cutting the first substrate on the singulation platform.

8. A system for manufacturing a device, comprising: a plurality of platforms, each platform being disposed below a corresponding optical head of a plurality of movable optical heads, each optical head corresponding to a laser source, each optical head including an interchangeable optical head, the interchangeable optical heads being staggeredly placed relative to each other such that laser beam paths of each optical head from each corresponding laser source do not intersect each other; a conveyor system coupled to the plurality of platforms; and a sorting system including a robot capable of moving devices from the conveyor system to at least one backend storage port or to a backend processor, wherein the plurality of platforms include a first platform and a second platform, the first platform and the second platform including a plurality of protrusions, and the plurality of protrusions are configured to fix a substrate including the plurality of optical devices by contacting a portion of the plurality of optical devices between regions of a device structure, each optical device having a contour surrounding region of the device structure.

9. The system according to claim 8, wherein the first platform is disposed below a first optical head, the first optical head being operable to direct a first laser beam from a first laser source towards the first platform; and the second platform is disposed below a second optical head, the second optical head being operable to direct a second laser beam from a second laser source towards the second platform, wherein the first platform and the second platform are operable relative to each other simultaneously.

10. The system according to claim 9, wherein the first optical head is movable in a first plane, and the second optical head is movable in a second plane, and the first plane is different from the second plane.

11. The system according to claim 10, wherein the first laser source is an infrared laser, and the second laser source is a carbon dioxide laser.

12. The system according to claim 9, further comprising at least one build station, the at least one build station being upstream of and adjacent to the first platform and the second platform; and a return conveyor system extending from a downstream end of the system to an upstream end of the system.

13. The system according to claim 12, further comprising a plurality of loading ports arranged adjacent to the at least one build station, wherein the at least one build station includes a carrier support, a substrate support, and a vacuum generator.

14. A system for manufacturing a device, comprising: a first platform disposed below a first optical head, the first optical head being operable to direct a first laser beam from a first laser source towards the first platform, the first platform including a first protrusion configured to secure a first substrate by contacting a first plurality of optical devices between first regions of a device structure, the first substrate including the first plurality of optical devices, each of the first plurality of optical devices having a first profile surrounding region of a first device structure; a second platform disposed below a second optical head, the second optical head being operable to direct a second laser beam from a second laser source towards the second platform, the second platform including a second protrusion configured to secure a second substrate by contacting a second plurality of optical devices between second regions of a device structure, the second substrate including the second plurality of optical devices, each of the second plurality of optical devices having a second profile surrounding region of a second device structure, wherein the first platform and the second platform are operable simultaneously relative to each other; a forward conveyor system coupled to the first platform and the second platform; a vision assembly including a camera disposed above the forward conveyor system; and a sorting system including a robot capable of moving devices from the conveyor system to at least one backend storage port or to a backend processor, wherein the robot is communicatively coupled to the vision assembly.

15. The system according to claim 14, further comprising a cleaning station for cleaning substrates separated from the device, for cleaning substrate carriers separated from the substrates, or a combination of the above.

16. The system according to claim 15, further comprising a cross conveyor system disposed between the cleaning station and the return conveyor system, wherein the return conveyor system is substantially parallel to the forward conveyor system.

17. The system according to claim 14, further comprising a building station disposed upstream of the first platform and the second platform, wherein the building station is configured to assemble each substrate onto each corresponding substrate carrier.

18. The system according to claim 14, wherein the first platform and the second platform are each movable along the XYZ directions and along a rotation angle (θ) about the Z direction.

19. The system according to claim 14, wherein each of the first optical head and the second optical head includes a plurality of optical lenses.

20. The system according to claim 14, wherein the system has a width of 3 meters to 6 meters and a length of 4 meters to 7 meters.

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