Advanced method for generating electrostatic chuck (ESC) mesa patterns

Abstract

Embodiments disclosed herein include an electrostatic chuck (ESC). In one embodiment, the ESC includes a substrate having a first surface, where the first surface has a first surface roughness. The ESC may further include a plurality of mesas extending upwardly from the first surface. In one embodiment, the plurality of mesas each includes a second surface, where the second surface has a second surface roughness. In one embodiment, the first surface roughness and the second surface roughness each have an average surface roughness Ra of approximately 0.3 [mu] m or less.

Description

Technical Field

[0001] Cross-references to related applications

[0002] This application claims priority to U.S. Patent Application No. 18 / 131,534, filed April 6, 2023, the entire contents of which are incorporated herein by reference.

[0003] The implementation relates to the field of semiconductor manufacturing, and more specifically, to a laser ablation process for manufacturing electrostatic chucks (ESCs) with customizable mesa and gas trench patterns. Background Technology

[0004] In semiconductor processing, chucks (such as electrostatic chucks (ESCs)) are used to hold wafers or other substrates during various processing operations. ESC devices generate an electrostatic clamping force against the ESC to hold the wafer. ESC devices can include Coulomb chucks or Johnsen-Rahbek (JR) chucks. Generally, the dielectric surface (typically ceramic) is the substrate that interfaces with the wafer. As semiconductor processing becomes more complex, so too does the complexity of ESCs. Often, the ceramic surface of the ESC is patterned to form features such as mesas (or protrusions) and trenches or channels for the flow of backside gas.

[0005] Currently, patterning of ceramic substrates is performed using mechanical removal processes. For example, masking, machining, grinding, and abrasive blasting are some of the processing operations required in the manufacture of ESCs. These processes are time-consuming. Furthermore, extensive cleaning is required to remove any residual particles that could cause contamination. Additionally, these processing operations can result in high surface roughness. Dimensional control in this process is also limited. For example, the common tolerance for machined features on ESCs is approximately 125 μm or greater. Existing processing operations also limit the flexibility of process design. Due to the complex nature of manufacturing, design changes (whether small or large-scale) may require entirely new process flows. Summary of the Invention

[0006] The embodiments disclosed herein include an electrostatic chuck (ESC). In one embodiment, the ESC includes a substrate having a first surface having a first surface roughness. The ESC may further include a plurality of mesa extending upward from the first surface. In one embodiment, each of the plurality of mesa includes a second surface having a second surface roughness. In one embodiment, both the first surface roughness and the second surface roughness have an average surface roughness Ra of approximately 0.3 μm or less.

[0007] The embodiments disclosed herein may also include an electrostatic chuck comprising a substrate having a center and an edge. In one embodiment, a first platform is located near the center of the substrate, wherein the first platform has a first shape and a first height. In one embodiment, a second platform is located near the edge of the substrate, wherein the second platform has a second shape and a second height. In one embodiment, the first shape differs from the second shape and / or the first height differs from the second height.

[0008] The embodiments disclosed herein further include a method for forming an electrostatic chuck. In one embodiment, the method includes polishing a first surface of a substrate and forming a plurality of mesa into the first surface of the substrate using a laser ablation process. In one embodiment, the method may further include forming gas trenches into the substrate between the mesa. Attached Figure Description

[0009] Figure 1A This is a plan view illustration of an electrostatic chuck (ESC) with a platform extending upwards from a ceramic substrate.

[0010] Figure 1B It is along line B-B' Figure 1A A cross-sectional diagram of the ESC in the image.

[0011] Figure 1C An enlarged diagram of an ESC with high surface roughness produced using a patterned surface manufactured using a conventional manufacturing process is shown.

[0012] Figure 2 This is a process flow diagram of a process for manufacturing an ESC using a laser ablation process according to one embodiment.

[0013] Figure 3A This is a cross-sectional view of a polished ESC substrate according to one embodiment.

[0014] Figure 3B This is a cross-sectional diagram of an ESC during a laser ablation process for forming a mesa, according to one embodiment.

[0015] Figure 3C This is a cross-sectional diagram of an ESC during a laser ablation process for forming gas trenches, according to one embodiment.

[0016] Figure 4A This is a cross-sectional diagram of an ESC with a uniform mesa according to one embodiment.

[0017] Figure 4B This is a cross-sectional diagram of an ESC with a platform according to one embodiment, the platform being higher at the center of the ESC than at the edges.

[0018] Figure 4CThis is a cross-sectional diagram of an ESC with a platform according to one embodiment, the platform being shorter at the center of the ESC than at the edges.

[0019] Figure 5 This is an enlarged cross-sectional diagram of the uniform surface roughness (ESC) between the top surface of the platform and the recessed surface of the substrate, according to an embodiment.

[0020] Figure 6A This is an enlarged cross-sectional view of an ESC with a platform according to one embodiment, the platform including a dome top surface and vertical sidewalls.

[0021] Figure 6B This is an enlarged cross-sectional diagram of an ESC with a dome-shaped platform according to one embodiment.

[0022] Figure 6C This is an enlarged cross-sectional diagram of an ESC with a platform of different shapes according to one embodiment.

[0023] Figure 6D This is an enlarged cross-sectional diagram of an ESC having a platform and gas channels between the platforms, according to one embodiment.

[0024] Figure 6E This is an enlarged cross-sectional view of an ESC having a platform and gas channels according to one embodiment, wherein the gas channels have rounded corners.

[0025] Figure 7 This is a plan view illustration of an ESC having a platform and gas channels according to one embodiment.

[0026] Figure 8 This is a plan view illustration of an ESC with a countertop according to one embodiment, the countertop having uneven dimensions from the center to the edge.

[0027] Figure 9 A block diagram of an exemplary computer system that can be used in conjunction with a processing tool according to one embodiment is shown. Detailed Implementation

[0028] The system described herein includes a laser ablation process for manufacturing electrostatic chucks (ESCs) with customizable tabletop and gas groove patterns. Several specific details are set forth in the following description to provide a thorough understanding of the embodiments. It will be apparent to those skilled in the art that embodiments can be practiced without such specific details. In other instances, well-known aspects have not been described in detail to avoid unnecessarily obscuring the embodiments. Furthermore, it will be understood that the various embodiments shown in the accompanying drawings are illustrative representations and are not necessarily drawn to scale.

[0029] To provide context for the embodiments disclosed herein, a common electrostatic chuck (ESC) 100 in Figure 1A The diagram shows that the ESC 100 may include a substrate 105 having a plurality of mesa 110. The mesa 110 may extend upward from the substrate 105 (i.e., extend outwards). Figure 1A The mesa 110 is a circular protrusion (of the flat surface). As indicated by uniform shading, the mesa 110 may be made of the same material as the substrate 105. More specifically, the mesa may be a component of the ESC 100. For example, a physical material removal process may be used to recess the top surface of the substrate 105 around the mesa 110.

[0030] As mentioned above, the manufacturing process used to form the mesa 110 on the ESC 100 is a physical material removal process. For example, masking, machining, grinding, and abrasive blasting are some of the processing operations performed to form the mesa 110. This process cannot achieve fine control over feature size or tolerance. For example, the tolerance may be approximately 125 μm or larger. Furthermore, extensive cleaning operations are required to prepare the ESC for use in processing environments (e.g., plasma chambers, rapid thermal processing chambers, or other processing chambers).

[0031] See now Figure 1B The illustration shows Figure 1A The cross-sectional diagram of ESC 100 along line B-B' is shown. As shown, mesa 110 has a uniform shape and size across the surface of substrate 105. That is, mesa 110 near the middle of substrate 105 can be substantially similar to mesa 110 near the edge of substrate 105.

[0032] The shape of the mesa 110 is not limited to structures that are easily machined using physical removal processes (such as those described above). For example, the mesa 110 has a rectangular shape. That is, the top surface 111 is substantially flat and parallel to the flat recessed surface 106 of the substrate 105. In addition, the sidewall surfaces 112 are substantially vertical. This shape can impair some semiconductor processing environments. For example, the sharp corners of the mesa 110 can be stress points or lead to the generation of unwanted particles. Therefore, it may be desirable to have a mesa shape 110 with a more rounded top surface 111.

[0033] Furthermore, the mesa 110 has a uniform width and height across the substrate 105. A uniform mesa 110 may be desirable for processing perfectly flat substrates. However, as layers are added to the substrate during manufacturing, the substrate may warp due to a mismatch in the coefficients of thermal expansion (CTE) between the materials. When using a uniform mesa 110, warped substrates may not be handled well or may result in additional stress. Therefore, in some embodiments, a non-uniform height and / or width of the mesa 110 may be required.

[0034] See now Figure 1C The diagram illustrates an enlarged cross-sectional view of the ESC 100. The enlarged section includes a pair of mesa 110s and a recessed surface 106 of the substrate 105 between the mesa 110s. As shown, the top surface 111 of the mesa 110s and the recessed surface 106 have different roughness levels. This is due to the processing of the ESC 100. For example, the top surface 111 of the mesa 110s may be polished and have a low surface roughness (in... Figure 1C The top surface 111 (which is substantially smooth) and the recessed surface 106 may have a large surface roughness. The low surface roughness of the top surface 111 may have an average roughness Ra of approximately 0.03 µm or less. The high surface roughness of the recessed surface 106 may have an average roughness Ra of approximately 0.3 µm or greater.

[0035] The surface roughness difference between the top surface 111 of the platform 110 and the recessed surface 106 of the substrate 105 can be a result of physical material removal operations. For example, machining, grinding, and / or sandblasting using abrasives can result in a rougher surface. Meanwhile, the top surface 111 can be protected with a masking layer after the substrate 105 has been polished using a polishing process before material removal begins. That is, existing physical material removal processes can lead to differences in surface roughness between different layers.

[0036] Therefore, the embodiments disclosed herein include advanced patterning processes to form mesas on a substrate. In a particular embodiment, the patterning process may include the use of a laser. The laser ablates the substrate material, rather than physically removing portions of the substrate. Generally, physical removal processes require one or more solid materials (e.g., machining tools, abrasives, etc.) to directly contact the substrate in order to remove portions of the substrate. Unlike such physical processes, electromagnetic radiation (i.e., from a laser) is used to directly remove portions of the substrate. In a particular embodiment, the laser is a picolases or has even higher pulse frequencies.

[0037] This implementation offers several advantages compared to existing solutions. One advantage is the controllability of the surface profile. The mesa can have a rounded surface or other uneven surface, not limited to a flat top surface. This can reduce stress points and minimize particle generation. Laser processing can also be used to create non-uniform mesa surfaces. For example, the mesa may be higher near the center of the substrate and shorter near the edge. Of course, the opposite configuration can also be implemented (i.e., shorter near the center and higher near the edge). Using laser processing also allows for easy control of the surface width.

[0038] Furthermore, the flexibility offered by the laser implementation allows for easy modification of the ESC design. Changes (such as laser movement, intensity, and the like) may be necessary to alter the ESC's structure. Such changes can be easily implemented by updating the laser's programming.

[0039] In one embodiment, the speed of manufacturing ESCs can also be increased. Instead of time-consuming physical removal processes (requiring extensive cleaning to remove particles), laser ablation is used to pattern the substrate. The laser can rapidly scan the surface of the substrate to pattern the desired structure. Furthermore, laser ablation does not create as many (or substantially any) particles. This eliminates the time required to clean the substrate after mesa fabrication. Additionally, the laser ablation process used to form mesa can also be used to (sequentially or simultaneously) form gas trenches into the substrate. This also reduces manufacturing time.

[0040] The embodiments disclosed herein also maintain a smooth surface on the patterned surface. For example, the top surface of the mesa may have a surface roughness approximately equal to that of the recessed surface of the substrate. The embodiments disclosed herein may include an average surface roughness Ra of approximately 0.3 µm or less, or approximately 0.03 µm or less.

[0041] See now Figure 2 The diagram illustrates a process flow chart of process 270 for manufacturing an ESC according to one embodiment. Processes 271-273 respectively correspond to... Figures 3A to 3C .

[0042] In one embodiment, process 270 may begin with operation 271, which includes polishing the top surface 321 of the ceramic substrate 305. For example... Figure 3A As shown, the ESC 300 includes a substrate 305. The substrate 305 can be any suitable dielectric ceramic material. For example, the substrate 305 may comprise alumina (Al2O3), or any other suitable dielectric ceramic material used in semiconductor manufacturing processes. The substrate 305 is illustrated as a solid material block. Nevertheless, it will be understood that embodiments may include the substrate 305, which includes electrodes or other components for implementing the ESC 300. In one embodiment, the substrate 305 may be approximately 100 µm thick or more. For example, in some embodiments, the substrate 305 may have a thickness of approximately 5,000 µm or more.

[0043] In one embodiment, the top surface 321 of the polishable substrate 305. For example, in some embodiments, a chemical mechanical polishing (CMP) process may be used. The polished top surface 321 may have an average surface roughness Ra of approximately 5 µm or less, approximately 1 µm or less, approximately 0.3 µm or less, or approximately 0.03 µm or less.

[0044] In one embodiment, process 270 can continue at operation 272, which includes forming a mesa on the top surface of the ceramic substrate using a laser ablation process. Although referred to as "laser ablation," it will be understood that material "evaporation" can also be a result of the laser process. Figure 3B As shown, laser 340 scans across substrate 305. In the illustrated embodiment, mesa 310 is formed in a single pass of laser 340. However, it will be understood that in some embodiments, two or more passes of laser 340 may be used to form mesa 310.

[0045] Laser 340 ablates the ceramic material to form a recessed surface 306. The recessed surface 306 may be provided around the mesa 310. In one embodiment, the mesa 310 may include a sidewall surface 312 and a top surface 311. In one embodiment, the sidewall surface 312 may be substantially vertical (i.e., perpendicular to the recessed surface 306). However, it will be understood that in some embodiments, depending on the laser parameters, the sidewall surface 312 may be inclined. In one embodiment, the top surface 311 may be coplanar with the top surface 321. That is, the top surface 311 may not undergo any laser ablation. However, in other embodiments, the top surface 311 may be the result of some laser ablation and may be below the top surface 321.

[0046] In one embodiment, laser 340 may be a high-pulse-frequency laser. In a particular embodiment, laser 340 has a pulse length in the picosecond range or faster (e.g., the femtosecond range). For example, laser 340 may be referred to as a picosecond laser. In a particular embodiment, a 290 fs laser 340 may be used. Any suitable wavelength of laser may be used. For example, in some embodiments, a 1030 nm laser may be used. The laser power may be set up to approximately 500 W. In a particular embodiment, the laser power may be approximately 100 W. As used herein, “approximately” may refer to a value within ten percent of said value. For example, approximately 100 W may refer to a range between 90 W and 110 W. Although specific ranges are provided herein, it will be understood that any configuration of laser 340 capable of precise photoablation may be used according to the embodiments disclosed herein.

[0047] The laser ablation process described herein provides a significant improvement in the tolerance of the mesa 310. For example, embodiments may include dimensional tolerances of less than 10 µm or less than 1 µm. This is a significant improvement compared to devices manufactured using physical material removal that have tolerances of 125 μm or greater. For example, in some embodiments, the height of the mesa 310 may be approximately 20 μm or less, approximately 15 μm or less, or approximately 10 μm or less. Additionally, although in Figure 3BAll tabletops 310 are illustrated as having the same height. It will be understood that implementations may include tabletops 310 with variable heights, as will be described in more detail below.

[0048] In one embodiment, process 270 can proceed to operation 273, which includes forming gas trenches on the top surface of the ceramic substrate using a laser ablation process. For example... Figure 3C As shown, laser 340 can scan across the substrate to form gas trenches 315 between mesas 310. In the illustrated embodiment, the mesas 310 are completed first, and then the gas trenches 315 are formed into the recessed surface 306. However, in other embodiments, the gas trenches 315 can be formed simultaneously with the formation of the mesas 310. In one embodiment, the same laser 340 can be used to form both the mesas 310 and the gas trenches 315. In other embodiments, different lasers 340 or the same laser with different laser settings can be used to form the mesas 310 and the gas trenches 315.

[0049] In one embodiment, the gas trench 315 may have a depth of approximately 10 μm or less. However, in some embodiments, deeper gas trenches 315 may also be used. In the illustrated embodiment, the gas trench 315 has a substantially flat bottom surface and vertical sidewalls. Nevertheless, other configurations may be used, as will be described in more detail below.

[0050] See now Figures 4A to 4C A series of ESC 400s are shown according to various implementation methods. Figures 4A to 4C Each of the ESC 400s illustrated in the diagram can be formed using processes such as process 270, which is described in more detail above. Additionally, although illustrated without gas channels, it will be understood that similar... Figure 3C As shown, gas trenches can be fabricated in substrate 405.

[0051] See now Figure 4A A cross-sectional view of an ESC 400 is illustrated according to one embodiment. In one embodiment, the ESC 400 includes a substrate 405. The substrate 405 may be a dielectric ceramic substrate. For example, the substrate 405 may contain aluminum and oxygen (e.g., aluminum oxide (Al2O3)). In one embodiment, a plurality of mesa 410 may extend upward from a recessed surface 406 of the substrate 405. The mesa 410 may have substantially similar shapes and dimensions across the substrate 405. For example, all mesa 410 may have a height H. The height H may be approximately 20 µm or less, approximately 15 µm or less, or approximately 5 µm or less.

[0052] In one embodiment, the mesa 410 may have a substantially flat top surface 411. That is, the top surface 411 may be substantially parallel to the recessed surface 406. In some embodiments, the top surface 411 may be connected to the recessed surface 406 by substantially vertical sidewalls. The shape of the mesa 410 may generally be considered rectangular (as viewed in cross-section). When viewed from above, the mesa 410 may be circular (to provide a cylindrical shape to the mesa 410). However, the laser ablation process is flexible, and the mesa 410 may have any three-dimensional shape. As used herein, the “shape” of the mesa 410 may be a reference to the three-dimensional shape of the mesa 410 or the cross-sectional shape of the mesa 410.

[0053] See now Figure 4B According to an additional embodiment, a cross-sectional view of the ESC 400 is illustrated. As shown, the ESC 400 includes a substrate 405 having a recessed surface 406. In one embodiment, a plurality of mesa may have non-uniform dimensions across the substrate 405. For example, a mesa 410 near the center of the substrate 405 may have a first height H1, and a second mesa 410 near the edge of the substrate 405 may have a second height H2. In one embodiment, the first height H1 may be greater than the second height H2. Furthermore, the mesa between the center and the edge may have a height that decreases from H1 to H2. This embodiment is advantageous when the wafer being processed on the ESC 400 has existing warpage.

[0054] See now Figure 4C According to yet another embodiment, a cross-sectional view of the ESC 400 is illustrated. In one embodiment, Figure 4C ESC 400 in the middle is similar to Figure 4B The difference between ESC 400 and ESC 405 lies in the opposite height. That is, the first height H1 near the center of substrate 405 can be smaller than the second height H2 near the edge of substrate 405. Similarly, the height of the platform 410 between the center and the edge can increase as it moves outward from its corresponding position. This embodiment is suitable for processing applications with... Figure 4B The illustrated embodiment shows a wafer with warping in the opposite direction.

[0055] See now Figure 5According to one embodiment, an enlarged cross-sectional view of an ESC 500 is illustrated. The ESC 500 may include a substrate 505. A mesa 510 may extend upward from a recessed surface 506. The top surface 511 of the mesa 510 may be connected to the recessed surface 506 via sidewalls 512. As mentioned above, the laser ablation process results in a substantially smooth surface. Even when the top surface 511 is a polished surface, the recessed surface 506 may maintain a similar surface roughness. That is, the surface roughness of the top surface 511 may be substantially equal to the surface roughness of the recessed surface 506. As used herein, "substantially equal" may refer to two values ​​within ten percent of each other. In a particular embodiment, the average surface roughness Ra of the top surface 511 and the recessed surface 506 may be approximately 5 µm or less, approximately 1 µm or less, approximately 0.3 µm or less, or approximately 0.03 µm or less. It will be understood that this uniformity of surface roughness differs from existing ESCs that use physical patterning processes, which leave recessed surfaces that are substantially rougher than the top surface of the tabletop.

[0056] Furthermore, although illustrated as having substantially equal surface roughness, the average surface roughness Ra of the top surface 511 may differ from the average surface roughness Ra of the recessed surface 506. In one embodiment, both surfaces 511 and 506 may be smoother than those provided by common mechanical removal processes (e.g., approximately 1 μm or less, approximately 0.3 μm or less, or approximately 0.03 μm or less surface roughness), but they are still different from each other. As an example, surface 511 may have a surface roughness of approximately 0.03 μm or less, and surface 506 may have a surface roughness of approximately 0.3 μm or less. Although an example of a smoother top surface 511 compared to a recessed surface 506 is provided, the implementation is not limited to this configuration. In other embodiments, the recessed surface 506 may be smoother than the top surface 511.

[0057] See now Figures 6A to 6E According to various embodiments, a series of cross-sectional diagrams depicting ESC600s with different mesa morphologies are illustrated. Different mesa morphologies are achieved using a laser ablation process. For example, different laser settings can be used to modify the shape of the mesa, and / or allow for different mesa shapes within a single ESC 600.

[0058] See now Figure 6A According to one embodiment, a cross-sectional view of an ESC 600 is illustrated. The ESC 600 may include a substrate 605 having a recessed surface 606. A mesa 610 may extend upward from the recessed surface 606. Figure 6AAs shown, the platform 610 may have an uneven top surface 611. The top surface 611 may be referred to as rounded or domed. In one embodiment, the top surface 611 may be connected to the recessed surface 606 via sidewalls 612 (such as vertical sidewalls 612). More specifically, the domed top surface 611 may be raised upward from the recessed surface 606.

[0059] See now Figure 6B According to another embodiment, a cross-sectional diagram of the ESC 600 is illustrated. Figure 6B In the illustrated embodiment, the top surface 611 is directly connected to the recessed surface 606. That is, the platform 610 can be described as having no sidewalls. Instead, the top surface 611 of the dome lies directly on the recessed surface 606.

[0060] See now Figure 6C According to another embodiment, a cross-sectional diagram of the ESC 600 is illustrated. Figure 6C In the illustrated embodiment, the platform 610 has an uneven shape. For example, the first platform 610A has a domed or curved top surface 611A, and the second platform 610B has a flat top surface 611B. Although in Figure 6C The illustration shows two examples of different platform 610 shapes, and it will be understood that any number of different platform 610 shapes can be formed using laser ablation processes, such as those described in more detail herein.

[0061] See now Figure 6D According to another embodiment, a cross-sectional diagram of the ESC 600 is illustrated. Figure 6D In the illustrated embodiment, the ESC 600 further includes gas channels 615 formed between the platform 610. The gas channels 615 may include a flat bottom surface 616. The bottom surface 616 may be parallel to the recessed surface 606. Furthermore, the gas channels 615 may have substantially vertical sidewalls 617.

[0062] See now Figure 6E According to another embodiment, a cross-sectional view of the ESC 600 is illustrated. Figure 6E As shown, the corners of the structure are rounded. For example, corner 613 (where the top surface 611 and the sidewall surface 612 meet) and corner 618 (where the recessed surface 606 and the bottom surface 616 meet) may be rounded. Furthermore, the bottom surface 616 of the gas groove 615 may also be rounded. It may be desirable to provide rounded corners to reduce high stress concentration and / or reduce particle generation. Such curved surfaces are not easily machined using standard physical machining processes.

[0063] See now Figure 7A plan view of an ESC 700 is illustrated according to one embodiment. In one embodiment, the ESC 700 may include a substrate 705 having a plurality of mezzanines 710 extending upward from the substrate 705. Although one configuration of the mezzanines 710 is shown as an example, it will be understood that the ESC 700 may include any number of mezzanines 710, including hundreds or more mezzanines 710. In one embodiment, the mezzanines 710 may have a uniform shape and size. In other embodiments, non-uniform shapes or sizes may be used, similar to any of the embodiments described in more detail herein.

[0064] In one embodiment, the ESC 700 may also include gas trenches 715. Gas trenches 715 can be used to distribute gas across the back side of a wafer or substrate undergoing forward processing. In one embodiment, gas trenches 715 may be fabricated (e.g., simultaneously or sequentially) with mesa 710 using a laser ablation process (such as those described in more detail herein). The location and number of gas trenches 715 are exemplary, and it will be understood that any configuration of gas trenches 715 can be used.

[0065] See now Figure 8 According to an additional embodiment, a plan view of the ESC 800 is illustrated. Specifically, the ESC 800 has mesa 810s of non-uniform size. For example, mesa 810C near the center of the substrate 805 has a first diameter, and mesa 810E near the edge of the substrate 805 has a different second diameter. Figure 8 In the illustrated embodiment, the first diameter is larger than the second diameter. However, in other embodiments, the first diameter may be smaller than the second diameter. Furthermore, in some embodiments, the spacing between the tabletops 810 may be non-uniform. Additionally, similar to other embodiments described in more detail herein, the tabletops 810 may have non-uniform heights.

[0066] Radial non-uniformity can also be applied to other parameters of the ESC. For example, surface roughness can be modulated across the surface of the ESC. In this embodiment, regions of the ESC at different radial locations can have different surface roughnesses. In one embodiment, the mesa of the ESC (in a first region toward the center of the ESC) can have a first surface roughness. Furthermore, the back-side gas sealing strip (in a second region toward the edge of the ESC) can have a second surface roughness less than the first surface roughness. This embodiment can result in improved sealing for the back-side gas during processing, while also improving desorption performance. A rougher mesa surface may be less sensitive to residual charge. Variable surface roughness can be achieved by modifying the laser parameters used to form various features.

[0067] See now Figure 9A block diagram of an exemplary computer system 900 of a processing tool is shown according to one embodiment. In one embodiment, the computer system 900 is coupled to and controls the processing within the processing tool. The computer system 900 may be connected (e.g., networked) to other machines in a local area network (LAN), an internal network, an external network, or the Internet. The computer system 900 may operate as a server or client machine in a client-server network environment, or as a peer machine in a peer (or distributed) network environment. The computer system 900 may be a personal computer (PC), a tablet PC, a set-top box (STB), a personal digital assistant (PDA), a cellular phone, an Internet access device, a server, a network router, a switch, or a bridge, or any machine capable of executing a set of instructions (continuously or otherwise) that specifies the actions to be taken by that machine. Furthermore, although only a single machine, the computer system 900, is shown, the term "machine" should also be considered to include any collection of machines (e.g., computers) that independently or jointly execute a set of instructions (or multiple sets of instructions) to perform any one or more methodologies described herein.

[0068] Computer system 900 may include a computer program product or software 922 having a non-transitory machine-readable medium on which instructions are stored, which can be used to program computer system 900 (or other electronic device) to perform a process according to an implementation. Machine-readable medium includes any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computer). For example, machine-readable (e.g., computer-readable) media include machine-readable storage media (e.g., read-only memory (“ROM”), random access memory (“RAM”), disk storage media, optical storage media, flash memory devices, etc.), machine-readable transmission media (e.g., electrical, optical, acoustic, or other forms of propagated signals (e.g., infrared signals, digital signals, etc.)), etc.

[0069] In one embodiment, the computer system 900 includes a system processor 902, main memory 904 (e.g., read-only memory (ROM), flash memory, dynamic random access memory (DRAM) such as synchronous DRAM (SDRAM), or Rambus DRAM (RDRAM), etc.), static memory 906 (e.g., flash memory, static random access memory (SRAM), etc.), and auxiliary memory 918 (e.g., data storage device), which communicate with each other via a bus 930.

[0070] System processor 902 represents one or more general-purpose processing devices, such as a microsystem processor, a central processing unit, or the like. More specifically, the system processor may be a Complex Instruction Set Computing (CISC) microsystem processor, a Reduced Instruction Set Computing (RISC) microsystem processor, a Very Long Instruction Word (VLIW) microsystem processor, or a system processor implementing other instruction sets, or a system processor implementing a combination of instruction sets. System processor 902 may also be one or more special-purpose processing devices, such as an Application-Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), a Digital Signal Processor (DSP), a Network System Processor, or the like. System processor 902 is configured to execute processing logic 926 for performing the operations described herein.

[0071] The computer system 900 may further include a system network interface device 908 for communicating with other devices or machines. The computer system 900 may also include a video display unit 910 (e.g., a liquid crystal display (LCD), a light-emitting diode display (LED), or a cathode ray tube (CRT)), an alphanumeric input device 912 (e.g., a keyboard), a cursor control device 914 (e.g., a mouse), and a signal generation device 916 (e.g., a speaker).

[0072] Auxiliary memory 918 may include machine-accessible storage medium 932 (or more specifically, computer-readable storage medium) storing one or more instruction sets (e.g., software 922) embodying any of the methodologies or functions described herein. Software 922 may also reside wholly or at least partially within main memory 904 and / or system processor 902 during its execution via computer system 900, main memory 904, and system processor 902, which also constitute machine-readable storage media. Software 922 may further be transmitted or received on network 960 via system network interface device 908. In one embodiment, network interface device 908 may operate using RF coupling, optical coupling, acoustic coupling, or inductive coupling.

[0073] Although machine-accessible storage medium 932 is shown as a single medium in the exemplary embodiment, the term "machine-readable storage medium" should be considered to include a single medium or multiple media (e.g., a centralized or distributed database, and / or associated caches and servers) that store one or more instruction sets. The term "machine-readable storage medium" should also be considered to include any medium capable of storing or encoding instruction sets for execution by a machine and causing the machine to execute any one or more methodologies. The term "machine-readable storage medium" should therefore be considered to include, but is not limited to, solid-state memory, as well as optical and magnetic media.

[0074] Specific exemplary embodiments have been described in the foregoing specification. It is obvious that various modifications can be made thereto without departing from the scope of the following claims. The specification and drawings are therefore to be considered illustrative rather than restrictive.

Claims

1. An electrostatic chuck (ESC), the ESC comprising: A substrate having a first surface, wherein the first surface has a first surface roughness; and Multiple platforms extending upward from a first surface, each platform including a second surface having a second surface roughness, wherein both the first and second surface roughnesses have an average surface roughness Ra of approximately 0.3 μm or less.

2. The ESC as claimed in claim 1, wherein the plurality of platforms have non-uniform heights.

3. The ESC of claim 2, wherein a first platform facing the center of the substrate has a first height, and wherein a second platform facing the edge of the substrate has a second height different from the first height.

4. The ESC as claimed in claim 3, wherein the first height is greater than the second height.

5. The ESC as claimed in claim 3, wherein the first height is less than the second height.

6. The ESC of claim 1, wherein the second surface is domed.

7. The ESC of claim 6, wherein the second surface is coupled to the first surface via substantially vertical sidewalls.

8. The ESC of claim 1, wherein the ESC further comprises gas trenches in the first surface of the substrate.

9. The ESC of claim 1, wherein the height of each of the plurality of platforms is up to approximately 15 μm.

10. The ESC of claim 1, wherein the first surface roughness is substantially equal to the second surface roughness.

11. The ESC of claim 1, wherein the first surface roughness is different from the second surface roughness.

12. The ESC of claim 1, wherein the ESC further comprises: A sealing strip facing the periphery of the substrate, wherein the sealing strip has a third surface roughness, wherein the third surface roughness is smoother than the second surface roughness line.

13. An electrostatic chuck (ESC), said ESC comprising: A substrate having a center and an edge; A first platform, the first platform being close to the center of the substrate, wherein the first platform has a first shape and a first height; as well as A second platform, the second platform being adjacent to the edge of the substrate, wherein the second platform has a second shape and a second height, and wherein the first shape is different from the second shape and / or the first height is different from the second height.

14. The ESC of claim 13, wherein the first height is greater than the second height.

15. The ESC of claim 13, wherein the first shape has a rectangular cross-section, and wherein the second shape has a dome cross-section.

16. The ESC of claim 13, wherein the dome surface of the second shape is connected to the substrate via substantially vertical sidewalls.

17. The ESC of claim 13, wherein the substrate has a first surface roughness, and the top surfaces of the first mesa and the second mesa have a second surface roughness, and wherein the first surface roughness is substantially equal to the second surface roughness.

18. The ESC of claim 17, wherein the first surface roughness and the second surface roughness have an average roughness Ra of approximately 1 μm or less.

19. A method for forming an electrostatic chuck (ESC), the method comprising: The first surface of the polished substrate; Multiple mesa are formed onto the first surface of the substrate using a laser ablation process; as well as Gas trenches are formed in the substrate between the mesa.

20. The method of claim 19, wherein the laser ablation process is performed using a picosecond pulse frequency laser or a laser with a higher pulse frequency.

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