Electrodes, workpiece holders, and semiconductor processing systems for ion implantation systems

Abstract

The present invention discloses thermal isolation tethering features disposed in various components of an ion implantation system. Specifically, an electrode, a workpiece holder, and a semiconductor processing system for an ion implantation system are disclosed. Electrodes such as a repeller electrode and a side electrode can be configured to have a tethering feature that serves as an electrode stem. Due to a gap disposed in the inner cavity of an expansion head that holds the electrode stem, the electrode stem makes minimal physical contact with the electrode block. In this way, the temperature of the electrode block can be maintained higher than otherwise possible when conduction is reduced. Additionally, this concept can be applied to a workpiece holder. For example, a ceramic platen is manufactured to have one or more tethering fasteners for attaching the platen to a base. This can minimize heat conduction between the platen and the base while providing an improved mechanical connection.

Description

Technical Field

[0001] Embodiments of the present disclosure relate to thermally isolated captive features, and more particularly, captive features for use in high temperature applications using ion implantation systems. Background Art

[0002] Various types of ion sources can be used to generate ions used in semiconductor processing equipment. For example, the Freeman ion source operates by supplying current to a filament that leads from one end of a chamber to an opposite end. The Bernas ion source and the Calutron ion source operate by supplying current to a filament that is disposed near one end of the chamber. In each of these ion sources, the filament emits thermal electrons that are emitted into the chamber. These electrons collide with a feed gas to generate a plasma.

[0003] Another type of ion source is an indirectly heated cathode (IHC) ion source. The IHC ion source operates by supplying an electric current to a filament disposed behind the cathode. The filament emits thermal electrons that accelerate toward the cathode and heat the cathode, which in turn causes the cathode to emit electrons into the chamber of the ion source. Since the filament is protected by the cathode, the life of the filament can be extended relative to the Berners ion source. The cathode is disposed at one end of the chamber. The repeller is typically disposed on the end of the chamber opposite to the cathode. The cathode and repeller can be biased to repel electrons, thereby directing the electrons back to the center of the chamber. In some embodiments, a magnetic field is used to further confine the electrons within the chamber.

[0004] In certain embodiments of these ion sources, side electrodes are also disposed on one or more walls of the chamber. These side electrodes can be biased positively or negatively to control the position of ions and electrons, thereby increasing the ion density near the center of the chamber. An extraction orifice is disposed along the other side near the center of the chamber, through which ions can be extracted.

[0005] When generating ions, the species of the desired ions can affect the optimal temperature. For example, for certain species, it may be preferable to maintain the ion source at a relatively low temperature. In other embodiments, such as ionizing carbon-based species, higher temperatures may be required to minimize deposition within the chamber.

[0006] Maintaining high temperatures within the chamber can be a problem. While the temperature of the components within the arc chamber is generally controlled by the amount of power dissipated by the filaments, the temperature of each component is limited by the amount of thermal radiation emitted and the amount of conduction that draws heat away from these components through mating components. For example, the repeller and electrodes may be physically attached to holders located outside the ion source that hold them in place. These holders may be constructed of metal and may be attached to a cooler assembly, such as the arc chamber base. This thermal path creates heat drawn away from the repeller and electrodes, which causes them to operate at a lower temperature than desired.

[0007] Additionally, the workpiece being processed may rest on a platen. In certain embodiments, it may be beneficial to maintain the platen at an elevated temperature. However, the platen is typically in communication with a larger base that is typically cooled and draws heat away from the platen. Additionally, locations where hot components meet cold components may experience high stress concentrations that may cause failures.

[0008] Therefore, a system that minimizes heat conduction between components within an ion implantation system may be beneficial. This can reduce the power required to maintain the components at high temperatures and reduce temperature gradients, which allows for a more robust design. In addition, it would be advantageous if the system also allowed for mechanical connections between these components. In this way, the components can be mechanically attached with reduced heat conduction. Summary of the invention

[0009] Thermally isolated tethered features disposed in various components of an ion implantation system are disclosed. Electrodes such as repellers and side electrodes may be configured with tethered features that act as electrode rods. Due to the gap disposed in the inner cavity of the expansion head that holds the electrode rods, the electrode rods are in minimal physical contact with the electrode block. In this way, the temperature of the electrode block can be maintained higher than would otherwise be possible when conduction is reduced. In addition, this concept can be applied to workpiece holders. For example, a ceramic platen is manufactured with one or more tethered fasteners for attaching the platen to a base. This can minimize thermal conduction between the platen and the base while providing an improved mechanical connection. In both cases, the tethered features are under high vacuum, which means that there is no gas in the gap between the connected objects. The lack of gas between the two components eliminates heat transfer by convection.

[0010] According to one embodiment, an electrode for an ion source is disclosed. The electrode includes: an electrode block suitable for being placed in an ion source, the electrode block having an inner cavity connected to the outside of the electrode block through an opening; and an electrode rod having a column and a flared head, wherein the flared head is placed in the inner cavity and the size of the flared head is such that it cannot pass through the opening. In some embodiments, the electrode includes a repeller. In some embodiments, the flared head includes a disk. In some embodiments, the flared head includes a plurality of spokes. In some embodiments, the flared head includes a dome, an inverted dome, a sphere, a cone, or a square. In some embodiments, the cross-sectional area of ​​the electrode rod decreases along its length. In some embodiments, the electrode includes a keying feature so that the electrode rod and the electrode block cannot rotate relative to each other.

[0011] According to another embodiment, a workpiece holder for use in an ion implantation system is disclosed. The workpiece holder includes: a pressure plate having an inner cavity connected to the outside of the pressure plate through an opening; and a tethered fastener having a shaft and a flaring head, wherein the flaring head is disposed in the inner cavity and the size of the flaring head is such that it cannot pass through the opening. In some embodiments, a protruding ring is disposed on the shaft to set the spacing between the pressure plate and the base. In some embodiments, the pressure plate and the tethered fastener are composed of ceramic. In some embodiments, the tethered fastener leaves the inner cavity perpendicular to the surface of the pressure plate. In some embodiments, the workpiece holder includes a base having a through hole through which the shaft of the tethered fastener passes, and further includes a retaining nut to attach the shaft to the base. In some embodiments, the workpiece holder includes a spacer around the tethered fastener to maintain separation between the pressure plate and the base. In some embodiments, the tethered fastener leaves the inner cavity at an angle relative to the surface of the pressure plate, wherein the angle is not vertical. In some embodiments, the flaring head includes a cylinder.

[0012] According to another embodiment, a semiconductor processing system is disclosed. The semiconductor processing system includes: an ion source; and an assembly, wherein the assembly includes: a body having an inner cavity connected to the outside of the body through an opening; and a captive fastener having an expansion head, wherein the expansion head is disposed in the inner cavity and the size of the expansion head is such that it cannot pass through the opening. In some embodiments, the assembly includes a mounting wall or a chamber wall. In some other embodiments, the semiconductor processing system includes a liner and a mating fastener, wherein the liner is held near the mounting wall or the chamber wall by attaching the mating fastener to the captive fastener. In another embodiment, the assembly includes a liner. In some other embodiments, the semiconductor processing system includes a wall having a threaded hole, wherein the liner is held near the wall by screwing the captive fastener into the threaded hole. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] For a better understanding of the present disclosure, reference is made to the accompanying drawings, which are incorporated herein by reference, and in which:

[0014] Figure 1 is an ion source according to one embodiment that may utilize the repeller and electrode designs described herein.

[0015] Figure 2 yes Figure 1 Cross-sectional view of the ion source.

[0016] Figure 3 is a cross-sectional view of a repeller according to an embodiment.

[0017] Figure 4A is a perspective view of a rod according to one embodiment.

[0018] Figure 4B is a perspective view of a rod according to another embodiment.

[0019] Figure 4C are cross-sectional and perspective views of a rod according to another embodiment.

[0020] FIG. 5A to FIG. 5E Various configurations of electrodes are shown.

[0021] Figure 6 Keying features are shown.

[0022] FIG. 7A to FIG. 7B Two configurations of electrodes are shown.

[0023] FIG. 8A to FIG. 8B Two configurations of electrodes are shown.

[0024] FIG. 9A to FIG. 9B A workpiece holder according to one embodiment is shown.

[0025] Fig.10 A workpiece holder with thermal spacers is shown.

[0026] FIG. 11A to FIG. 11D A workpiece holder according to another embodiment is shown.

[0027] FIG. 12A to FIG. 12C Chamber walls and linings are shown according to various embodiments. DETAILED DESCRIPTION

[0028] As described above, in certain situations, it may be beneficial to operate an ion source, such as an indirectly heated cathode (IHC) ion source, at high temperatures. However, repellers and electrodes conduct a large amount of heat away from the chamber. The present disclosure describes a new repeller and electrode design that minimizes this heat loss.

[0029] Figure 1 An ion source 10 is shown that includes a repeller 120 and side electrodes 130a, 130b that overcome these problems. Figure 2 Show Figure 1 1 is a cross-section of an ion source. The ion source 10 may be an indirect heated cathode (IHC) ion source. The ion source 10 includes a chamber 100, which includes two opposite ends and walls 101 connected to these ends. These walls 101 include side walls 104, an extraction plate 102, and a bottom wall 103 opposite to the extraction plate 102. The walls 101 of the chamber 100 may be made of a conductive material and may be electrically connected to each other. The cathode 110 is arranged in the chamber 100 at the first end 105 of the chamber 100. The filament 160 is arranged behind the cathode 110. The filament 160 is connected to a filament power supply 165. The filament power supply 165 is configured to pass an electric current through the filament 160 so that the filament 160 emits thermal electrons. The filament bias power supply 115 negatively biases the filament 160 relative to the cathode 110 so that these hot electrons are accelerated from the filament 160 toward the cathode 110 and heat the cathode 110 when they strike the rear surface of the cathode 110. The filament bias power supply 115 may bias the filament 160 so that it has a voltage that is more negative than the voltage of the cathode 110, for example, between 200 volts and 1500 volts. The cathode 110 then emits the hot electrons on its front surface into the chamber 100.

[0030] Thus, the filament power supply 165 supplies current to the filament 160. The filament bias power supply 115 biases the filament 160 so that the filament 160 is more negative than the cathode 110 so that electrons are attracted from the filament 160 toward the cathode 110. In some embodiments, the cathode 110 is also in communication with the cathode bias power supply 125. In other embodiments, the cathode 110 can be grounded. In some embodiments, the chamber 100 is connected to an electrical ground. In some embodiments, the wall 101 provides a ground reference for other power supplies.

[0031] In this embodiment, repeller 120 is disposed in chamber 100 in a second end 106 of chamber 100 opposite cathode 110. As the name implies, repeller 120 is used to repel electrons emitted from cathode 110 back toward the center of chamber 100. For example, in some embodiments, repeller 120 may be in communication with a power source. In other embodiments, repeller 120 may float relative to chamber 100. In other words, when floating, repeller 120 is not electrically connected to the power source or chamber 100. In this embodiment, the voltage of repeller 120 tends to drift to a voltage close to the voltage of cathode 110.

[0032] In certain embodiments, a magnetic field 190 is generated in the chamber 100. This magnetic field is intended to confine electrons along one direction. The magnetic field 190 generally extends parallel to the sidewalls 104 from the first end 105 to the second end 106. For example, the electrons may be confined in a column parallel to the direction from the cathode 110 to the repeller 120 (i.e., the y-direction). Thus, the electrons do not experience any electromagnetic force to move in the y-direction. However, the movement of electrons in other directions may experience electromagnetic forces.

[0033] exist Figure 1 In the embodiment shown in FIG. 1 , the first side electrode 130a and the second side electrode 130b may be disposed on the sidewall 104 of the chamber 100 such that the side electrodes are located within the chamber 100. The side electrodes may each be floating or in communication with a power source. Figure 2 Show Figure 1 1. A cross-sectional view of an ion source 10 of FIG. 1. In this figure, cathode 110 is shown against first end 105 of ion source 10. First side electrode 130a and second side electrode 130b are shown on opposite walls 101 of chamber 100. Magnetic field 190 is shown directed out of the page in the Y direction. In some embodiments, the electrodes can be separated from wall 101 of chamber 100 by using an insulator.

[0034] Each of the cathode 110 , the repeller 120 , the first side electrode 130 a , and the second side electrode 130 b is made of a conductive material such as metal. Each of these components may be physically separated from the wall 101 .

[0035] Disposed on the extraction plate 102 may be an extraction orifice 140. Figure 1 In FIG. 1 , the extraction orifice 140 is disposed on a side parallel to the XY plane (parallel to the page). In addition, although not shown, the ion source 10 further includes a gas inlet through which a gas to be ionized is introduced into the chamber 100 .

[0036] The controller 180 may be in communication with one or more of the power supplies so that the voltage or current supplied by these power supplies can be modified. The controller 180 may include a processing unit 181, such as a microcontroller, a personal computer, a dedicated controller, or another suitable processing unit. The controller 180 may also include a non-transitory storage element, such as a semiconductor memory, a magnetic storage, or another suitable memory. This non-transitory storage element may contain instructions and other data that allow the controller 180 to perform the functions described herein.

[0037] In operation, electrons are emitted by cathode 110. These electrons may be constrained by magnetic and electric fields within chamber 100 to collide with a feed gas to produce plasma 150. Electrodes external to chamber 100 may be used to extract ions from plasma 150 through extraction orifice 140.

[0038] As described above, in certain embodiments, it is advantageous to operate the ion source at high temperatures. These high temperatures can help prevent material from being deposited on components within the chamber 100. For example, when ionizing carbon-based species, carbon tends to accumulate on internal surfaces, repeller 120, and side electrodes 130a, 130b. One way to minimize this deposition is to increase the temperature within the chamber 100, and more specifically, the temperature of the repeller 120 and side electrodes 130a, 130b.

[0039] As described above, the repeller 120 and the side electrodes 130a, 130b may be attached to an external holder 195 supported by the chamber base 198 (see Figure 2 ), the outer holder 195 may be at a lower temperature, such as less than 400° C. However, it may be desirable to maintain the repeller 120 and the side electrodes 130a, 130b at a temperature closer to the temperature within the chamber 100, which may be 600° C. or greater.

[0040] The repeller 120 and / or the side electrodes 130a, 130b may be formed with thermally isolated tethering features. Figure 3 An embodiment of an electrode utilizing a thermal isolation tethering feature is shown.The term "electrode" is used to encompass both the repeller 120 and the side electrodes 130a, 130b.

[0041] The electrode 250 may include an electrode block 200 and an electrode rod 210. The electrode block 200 may be disc-shaped, rectangular or any other suitable shape. An inner cavity 201 is disposed in the electrode block 200. The inner cavity 201 communicates with the outside of the electrode block 200 via an opening 202.

[0042] The electrode rod 210 may have a post 211 and a flared end 212. The post 211 may be a straight cylindrical rod. The flared end 212 is disposed within the inner cavity 201 of the electrode block 200. The electrode rod 210 is sized so that the cross-sectional area of ​​the post 211 is smaller than the cross-sectional area of ​​the opening 202. In addition, the flared end 212 is sized so that the cross-sectional area of ​​the flared end 212 is larger than the cross-sectional area of ​​the opening 202. In this way, the electrode rod 210 is captively held by the electrode block 200. In some embodiments, the gap between the flared end 212 and the inner cavity 201 may be .001", but may be larger or smaller than this value.

[0043] In addition, in some embodiments, the volume of the inner cavity 201 is larger than the volume of the expansion head 212 so that there is a gap between the expansion head 212 and the electrode block 200 at most positions. As long as the opening 202 prevents the electrode rod 210 from detaching from the electrode block 200, the internal geometry of the inner cavity 201 can be any shape.

[0044] In some embodiments, the electrode 250 can be produced by using additive manufacturing technology. Additive manufacturing technology allows components to be manufactured in different ways. Additive manufacturing technology produces components in a layer-by-layer manner instead of removing material as traditionally done. One such additive manufacturing technology, called Direct Metal Laser Sintering (DMLS), uses a powder bed and a laser. A thin layer of powder is applied to the workpiece space. The laser is used to sinter the powder only in the area where the component is to be formed. The remaining portion of the metal powder remains and forms a powder bed. After the laser process is completed, another thin layer of metal powder is applied on top of the existing powder bed. The laser is used again to sinter specific locations. This process can be repeated any number of times.

[0045] While DMLS is one technology, there are many others. For example, metal binder jetting is similar to DMLS, except that instead of using a laser to sinter the powder, a liquid binder is applied to the areas where the component is to be formed. Another example of additive manufacturing is electron beam printing. In this embodiment, a metal filament is extruded from a nozzle, and a laser or electron beam is used to melt the metal as it is extruded. In this embodiment, the metal is applied only to those areas that are to become part of the component. Of course, other types of additive manufacturing can also be used, such as fused filament directed energy deposition, laminate lamination, powder bed fusion, material extrusion, and Vat Photopolymerization.

[0046] Using additive manufacturing, the electrode 250 can be printed / grown in one go so that the electrode rod 210 is truly tethered inside the electrode block 200 and does not require any components. Depending on the manufacturing process, the electrode 250 can be cleaned to remove powder trapped in the small gap between the electrode block 200 and the electrode rod 210.

[0047] Figure 4A 2 shows a perspective view of an electrode rod 210 according to one embodiment. In this embodiment, the expanded head 212 is in the shape of a disk 213. The outer diameter of this disk 213 is larger than the diameter of the opening 202 that holds the electrode rod 210 tethered. In certain embodiments, the disk 213 may also be concave, wherein the disk 213 extends outwardly and away from the electrode rod 210. In other embodiments, the disk 213 may be planar so that it only extends outwardly from the electrode rod 210. Furthermore, in certain embodiments, the disk 213 may have an enlarged rim 214 on its outer circumference.

[0048] Figure 4B FIG. 2 shows a perspective view of an electrode rod 210 according to a second embodiment. In this embodiment, the expanded head 212 includes a plurality of spokes 215. Figure 4BFour spokes 215 are shown, but the number of spokes 215 is not limited by the present disclosure. In some embodiments, the spokes 215 extend outward and away from the electrode rod 210. In other embodiments, the spokes may be planar and extend only outward from the electrode rod 210. Each spoke may have a width of 0.1 inches, but other sizes are possible.

[0049] FIG. 5A to FIG. 5E Other configurations are shown where the electrode shaft 210 has a flared head 212 to remain tethered to the lumen 201 of the electrode block 200 .

[0050] Figure 5A The electrode rod 210 is shown with the expansion head 212 being dome-shaped.

[0051] Figure 5B The electrode rod 210 is shown with the expanded head 212 being in the shape of an inverted dome.

[0052] Figure 5C The electrode rod 210 is shown with the expansion head 212 gradually narrowing in a conical shape.

[0053] Figure 5D The electrode shaft 210 is shown with the expanded head 212 being a ball.

[0054] Figure 5E The electrode rod 210 is shown with the expansion head 212 being a square block. This has the benefit that the electrode block 200 and the electrode rod 210 cannot rotate relative to each other.

[0055] However, other embodiments may be modified to inhibit relative rotation between the electrode shaft 210 and the electrode block 200. For example, a keying feature 216 may be added to the lumen 201 and / or the expanded head 212. Figure 6 A partially truncated embodiment of the lumen 201 is shown. The expansion head 212 will be similarly truncated so that these components cannot rotate relative to each other.

[0056] In all of these embodiments, when assembled in the chamber 100 under vacuum conditions, the electrode rod 210 makes minimal physical contact with the electrode block 200. For example, the physical contact may be limited to locations along only a portion of the outer edge of the expansion head 212, where gravity forces the electrode block 200 downward. For this reason, there is minimal heat conduction between the electrode block 200 and the electrode rod 210. Therefore, there may be a large temperature difference between the electrode block 200 and the electrode rod 210.

[0057] The heat conduction of the electrode rod 210 can be further reduced by reducing the cross-sectional area of ​​the electrode rod 210. For example, Figure 4C As shown in Figure 4AIn one embodiment, the electrode rod 210 is similar to the electrode rod in FIG. However, in this embodiment, a portion of the electrode rod 210 may be hollow. In other embodiments, the cross-sectional area of ​​the electrode rod 210 may be reduced in one or more directions.

[0058] It should be noted that Figures 3 to 6 Describe the electrode block 200 and the tethered electrode rod 210. This structure can be applied to the repeller 120 and the side electrodes 130a, 130b. In these embodiments, the shape of the side electrode block can be different from the shape of the repeller block. However, the structure and function of the inner cavity 201, the opening 202 and the expansion head 212 are as explained above.

[0059] In some embodiments, the electrode rod 210 is tethered using a different mechanism. Fig. 7A As shown in FIG. 3 , the electrode block 300 has a flared protrusion 301. In this embodiment, the electrode rod 310 has an inner cavity 311 to keep the flared protrusion 301 captive. In this embodiment, the flared protrusion 301 can be any desired shape, such as FIG. 4A to FIG. 4B and FIG. 5A to FIG. 5E The shapes shown in .

[0060] Figure 7B An embodiment is shown in which the electrode block 320 has an inner cavity 321 with a flared protrusion 322 disposed in the inner cavity 321. The electrode rod 330 has an inner cavity 331 in which the flared protrusion 322 is held captive, and also has a flared head 332 held captive in the inner cavity 321.

[0061] In some embodiments, the entire electrode rod is not tethered. Fig. 8A As shown in FIG, the electrode block 340 has an inner cavity 341 similar to the inner cavity described above. However, the nut 350 is held captive in the inner cavity 341 instead of holding the entire electrode rod captive. The electrode rod 360 having a threaded end is then screwed into the nut 350. This embodiment can simplify the design of the electrode block 340.

[0062] Figure 8B Another embodiment is shown where the entire electrode rod is not held captive. The electrode block 370 has an inner cavity 371 similar to the inner cavity described above. However, instead of holding the entire electrode rod captive, a threaded bolt 380 is held captive in the inner cavity 371. The electrode rod 390 having a threaded opening is then screwed into the threaded bolt 380.

[0063] Therefore, in some embodiments, the electrode block is made with a tethered feature. A tethered feature is a feature that cannot be detached from the electrode block because the expanded head cannot pass through the opening. However, the tethered feature is separated from the electrode block so that heat conduction is reduced or eliminated. In many embodiments (e.g. FIG. 4A to FIG. 4C, FIG. 5A to FIG. 5E as well as Figures 6 to 7B In some embodiments (such as those shown in FIG), the tethered feature is the entire electrode rod. FIG. 8A to FIG. 8B In those embodiments shown in ), the tethered feature is a component to which the electrode rod can be attached.

[0064] In many applications, the electrodes are used in a high vacuum environment. In this environment, there is no convection between the electrode block and the electrode rod. Therefore, any heat transfer is the result of radiation and conduction only.

[0065] The concept of thermally isolated tethered features can be used in other areas within an ion implantation system. For example, Fig. 9A A workpiece holder is shown that includes a platen 400 disposed on a base 410. The platen 400 may be separated from the base 410 by a predetermined spacing "d". In certain embodiments, it may be advantageous to maintain the platen 400 at an elevated temperature. However, the base 410 is typically made of metal (e.g., aluminum) and thus acts as a heat sink. However, a mechanical attachment mechanism is used to attach the platen 400 to the base 410. This mechanical attachment mechanism may be a source of heat conduction between the platen 400 and the base 410.

[0066] In this embodiment, the mechanical attachment mechanism is a captive fastener 450 that is thermally isolated from the platen 400. Fig. 9B As best seen in FIG. 4 , captive fastener 450 may be disposed within inner cavity 401 of platen 400. Inner cavity 401 communicates with the exterior of platen 400 via opening 402. Captive fastener 450 and opening 402 are sized such that captive fastener 450 cannot be separated from platen 400. In certain embodiments, the gap between captive fastener 450 and inner cavity 401 may be in the range of 0.001 inches, although this gap may be larger or smaller depending on the embodiment. Platen 400 may be constructed of a ceramic material.

[0067] Since the retention fastener 450 cannot be separated from the press plate 400, the press plate 400 and the retention fastener 450 are manufactured as one component. Specifically, additive manufacturing is used to deposit a mixture of ceramic powder and binder. In most areas, a single ceramic press plate is produced after sintering due to this mixture. In those areas where gaps or empty spaces are to be left (such as the empty part of the inner cavity 401), only one of the ceramic powder and the binder is deposited. The deposition of the material is used to maintain the integrity of the press plate 400 during the additive manufacturing process. However, since only one of the ceramic powder and the binder is deposited, this area will not harden after sintering. In this way, the retention fastener 450 can be accommodated in the inner cavity 401 of the press plate 400 without being physically attached thereto. The deposition process is repeated for each layer until the entire press plate 400 and the retention fastener 450 have been printed. After all the materials required to form the press plate 400 and the retention fastener 450 have been deposited, the assembly is placed in a furnace for sintering the assembly. After sintering, the press plate 400 and the captive fastener 450 have become hardened ceramic. However, the void area is not hardened. In an embodiment where the ceramic powder is deposited only in the void area, the ceramic powder may remain in powder form after sintering. In this embodiment, it may be necessary to clean the inner cavity 401. This can be achieved by introducing pressurized air or another fluid into the inner cavity 401. In another embodiment, a vacuum may be applied to the inner cavity 401 to suck the powder. In an embodiment where the binder is deposited only in the void area, the binder may evaporate during the sintering process, leaving air gaps in the press plate 400. In this embodiment, the cleaning process may not be performed.

[0068] Binder jetting is only one method of producing ceramics. However, other methods are possible. Material jetting or stereolithography are also methods used to make additively manufactured ceramic parts. In these cases, the photosensitive resin is cured by UV light. The gap is still maintained between the parts but will be filled with uncured resin (SLA) or support material (material jetting). In these cases, support / uncured material removal will be performed.

[0069] The captive fastener 450 may include a shaft 460 that is threaded along at least a portion of its length. The shaft 460 terminates in a flared head 470. The flared head may be configured to FIG. 4A to FIG. 4B or FIG. 5A to FIG. 5E The expansion head 470 is similar to those shown in FIG. The expansion head 470 is disposed in the inner cavity 401 of the pressure plate 400. The retention fastener 450 is made of the same material as the pressure plate 400. The protruding ring 461 can be disposed along the shaft 460. The orientation of the protruding ring 461 is used to create a predetermined spacing "d" between the pressure plate 400 and the base 410.

[0070] Captive fastener 450 may be inserted into opening 411 in base 410. In one embodiment, opening 411 may be a through hole and retaining nut 420 may be used to attach captive fastener 450 to base 410.

[0071] Although Fig. 9A Two captive fasteners 450 are shown, but the number of captive fasteners 450 is not limited by the present disclosure.

[0072] In addition, if Fig.10 In other embodiments, as shown in FIG. 4 , a thermal spacer 462 may be disposed around the captive fastener 450 to maintain the desired separation between the platen 400 and the base 410 rather than having a protruding ring 461 . The thermal spacer 462 may be a washer around the captive fastener 450 .

[0073] In addition, although FIG. 9A to FIG. 9B and Fig.10 Captive fasteners 450 are shown oriented perpendicular to the surface of base 410, but other embodiments are possible.

[0074] FIG. 11A to FIG. 11D Another embodiment of attaching the platen 500 to the base 510 using a captive fastener 550 is shown. In this embodiment, the captive fastener 550 may include a shaft 560 that is threaded along at least a portion of its length. The shaft terminates in a flaring head 570. In this embodiment, the flaring head 570 is cylindrical, but may be used, for example Figures 3 to 6 As previously described, the pressure plate 500 has an inner cavity 501 that communicates with the exterior through an opening 502. The flared head 570 and the opening 502 are sized so that the captive fastener 550 cannot be separated from the pressure plate 500. In this embodiment, the opening 502 is elongated to allow the captive fastener 550 to rotate within the pressure plate 500. Likewise, the opening 511 in the base 510 is also elongated.

[0075] like Fig. 11B As shown in FIG. 5 , captive fastener 550 is inserted into corresponding opening 511 in base 510. This can be performed by aligning platen 500 and base 510 so that captive fastener 550 extends from opening 502 perpendicular to the surface of base 510. Captive fastener 550 is then passed through opening 511 in base 510.

[0076] Once the captive fastener 550 is inserted into the opening 511 in the base 510, the captive fastener 550 can be rotated at an angle relative to the surface of the pressure plate 500, such as Fig. 11C. This angle is different from vertical and can be between 25 and 65 degrees, but other angles are possible. This angle allows the pressure plate 500 to be secured to the base 510 in two directions, which can create a more stable connection. The captive fastener 550 can be attached to the base 510 using a retaining nut 515, such as Fig.11D In addition, the protruding ring 553 can be used to limit the movement of the captive fastener 550.

[0077] Thus, the present disclosure describes a body, such as an electrode block or a pressure plate, that includes a captive fastener, wherein the physical contact between the captive fastener and the body is minimized. This allows the block to remain at its desired temperature and limits the amount of heat conduction between the body and the captive fastener. While the above disclosure describes this with respect to electrodes and pressure plates, other components within a semiconductor processing system may benefit from this arrangement. These components include a liner disposed in an ion source. Captive fasteners may be used to hold the liner in place while minimizing heat conduction between the liner and the ion source chamber wall.

[0078] FIG. 12A to FIG. 12C Various embodiments are shown that can be used to attach the liner to a wall, such as a chamber wall or a mounting wall. The wall can be the inner wall of an ion source chamber, the inner wall of a mass analyzer, the interior surface of a scanner, the interior surface of a collimator magnet, or another suitable location.

[0079] exist FIG. 12A to FIG. 12B In the embodiment of the present invention, the wall 1200 includes a captive fastener 1210. The wall 1200 can be a conductive material, such as a metal or another suitable material. In these embodiments, a liner 1230 is disposed adjacent to the wall 1200 to protect the wall 1200 from ion impact. However, it may be beneficial to have limited thermal conductivity between the wall 1200 and the liner 1230. As described above, the wall 1200 includes an inner cavity 1201 that holds the captive fastener, wherein the inner cavity 1201 communicates with the exterior of the wall through an opening 1202. The captive fastener has a flared end that is sized so that the flared end cannot be withdrawn through the opening 1202.

[0080] The mating fastener 1220 is disposed on a side of the liner 1230 opposite the wall 1200. In certain embodiments, the liner 1230 includes a through-hole 1231. The captive fastener 1210 or the mating fastener 1220 passes through the through-hole 1231. When the captive fastener 1210 and the mating fastener 1220 are attached, a gap remains between the wall 1200 and the liner 1230. In addition, as described above, there is minimal thermal conductivity between the wall 1200 and the captive fastener 1210.

[0081] exist Fig. 12A In the embodiment, the captive fastener 1210 is a nut and the mating fastener 1220 is a screw or a threaded bolt. Fig. 12BIn the embodiment, the captive fastener 1210 is a screw or a threaded bolt, and the mating fastener 1220 is a nut.

[0082] exist FIG. 12A to FIG. 12B In some embodiments, the captive fasteners may have spacer features to ensure that the wall 1200 and the liner 1230 do not come into physical contact.

[0083] Fig. 12C Another embodiment is shown. In this embodiment, the liner 1330 includes a captive fastener 1320 retained in the inner cavity 1331. In this embodiment, the inner cavity is connected to the outside of the liner 1330 via openings 1332 and 1333 on both sides of the liner 1330. The captive fastener 1320 includes a screw with an expanded head and a threaded shaft 1321. The expanded head cannot pass through any opening. The threaded shaft 1321 passes through the opening 1332. The wall 1300 includes a threaded hole 1310. The captive fastener 1320 can be screwed into the threaded hole 1310. In some embodiments, the opening 1333 allows a tool (such as a screwdriver) to be inserted into the inner cavity 1331 to assemble the liner 1330 and the wall 1300. The length of the threaded shaft 1321 is such that when fully inserted into the threaded hole 1310, the liner 1330 remains separated from the wall 1300.

[0084] Of course, other components within the semiconductor processing system may also be produced with captive fasteners. These components include electrodes in the acceleration / deceleration stages, extraction optics, or other suitable locations.

[0085] The above-described embodiments in the present application may have many advantages. With respect to the electrode design, there is very limited heat conduction due to the limited physical contact between the electrode rod and the electrode block. In practice, most of the heat transfer will occur via radiation, which is typically very low due to the fact that the electrodes typically operate under vacuum conditions. As a result, the electrode block can be maintained at a much higher temperature than that achieved with conventional electrodes. This may be beneficial for processes involving carbon, which tends to deposit on any component in the arc chamber that has a temperature less than about 800°C. In addition, other methods traditionally used to add heat to the arc chamber (e.g., by resistive heaters, radiation shields, etc.) may be eliminated because the electrodes disclosed herein still achieve the desired high temperatures.

[0086] Furthermore, the assembly of this electrode may be simpler than other solutions. For example, in some conventional systems, a two-part repeller may be used, where the rod is made of a less conductive material than the repeller disk. However, these repellers must be assembled. There is no assembly of the electrode described herein.

[0087] With respect to the workpiece holders, the workpiece holders described herein are easier to assemble than conventional systems utilizing springs, thermal insulators, movable bolts, and loose mounting points.

[0088] In addition, the use of tethered features allows thermal expansion to occur with limited stress. In other words, because there is a gap in the inner cavity around the tethered feature, the tethered feature can expand without contacting the inner cavity. This reduces the thermal stress that normally occurs when hot components are connected together.

[0089] The present disclosure is not limited in scope by the specific embodiments described herein. In fact, in addition to those described herein, various other embodiments and modifications of the present disclosure will be apparent to those of ordinary skill in the art based on the foregoing description and the accompanying drawings. Therefore, such other embodiments and modifications are intended to fall within the scope of the present disclosure. In addition, although the present disclosure has been described in the context of a specific implementation in a specific environment for a specific purpose, it will be appreciated by those of ordinary skill in the art that the usefulness of the present disclosure is not limited thereto, and the present disclosure can be beneficially implemented in any number of environments for any number of purposes. Therefore, the claims set forth above should be interpreted in view of the full breadth and spirit of the present disclosure as described herein.

Claims

1. An electrode for an ion source, include: an electrode block adapted for placement within the ion source, the electrode block having a closed interior cavity communicating with an exterior of the electrode block through only one opening, wherein the opening does not extend through the electrode block; as well as An electrode rod has a post and a flared head, wherein the flared head is disposed in the closed inner cavity and is sized so that it cannot pass through the opening, and the flared head remains captive in the closed inner cavity of the electrode block.

2. The electrode for an ion source according to claim 1, wherein the electrode comprises a repeller. The electrode for an ion source according to claim 1 , wherein the expansion head comprises a disk. The electrode for an ion source according to claim 1 , wherein the expansion head comprises a plurality of spokes. 5 . The electrode for an ion source according to claim 1 , wherein the expansion head comprises a dome shape, a reverse dome shape, a sphere, a cone, or a square.

6. The electrode for an ion source according to claim 1, wherein the cross-sectional area of ​​the electrode rod decreases along its length.

7. The electrode for an ion source of claim 1, further comprising a keying feature such that the electrode rod and the electrode block cannot rotate relative to each other.

8. A workpiece holder for use in an ion implantation system, include: a platen having an enclosed interior cavity communicating with an exterior of the platen through only one opening, wherein the opening does not extend through the platen; as well as A captive fastener has a shaft and a flared head, wherein the flared head is disposed in the closed interior cavity and the flared head is sized so that it cannot pass through the opening, and the flared head remains captive in the closed interior cavity of the platen.

9. The workpiece holder for use in an ion implantation system of claim 8, wherein a protruding ring is disposed on the shaft to set the spacing between the pressure plate and the base.

10. The workpiece holder for use in an ion implantation system of claim 8, wherein the pressure plate and the captive fastener are comprised of ceramic.

11. The workpiece holder for use in an ion implantation system of claim 8, wherein the captive fastener exits the enclosed interior cavity perpendicular to a surface of the platen.

12. The workpiece holder for use in an ion implantation system of claim 8, further comprising a base having a through hole through which the shaft of the captive fastener passes, and further comprising a retaining nut to attach the shaft to the base.

13. The workpiece holder for use in an ion implantation system of claim 12, further comprising a spacer surrounding the captive fastener to maintain separation between the pressure plate and the base.

14. The workpiece holder for use in an ion implantation system of claim 8, wherein the captive fastener exits the enclosed interior cavity at an angle relative to a surface of the platen, wherein the angle is non-vertical.

15. The workpiece holder for use in an ion implantation system of claim 8, wherein the expansion head comprises a cylinder.

16. A semiconductor processing system, include: Ion source; as well as A component, wherein the component comprises: a body having an enclosed interior cavity in communication with an exterior of the body through only one opening, wherein the opening does not extend through the body; as well as A captive fastener having an expanded head, wherein the expanded head is disposed in the closed interior cavity and the expanded head is sized so that it cannot pass through the opening, and the expanded head remains captive in the closed interior cavity of the body.

17. The semiconductor processing system of claim 16, wherein the component comprises a mounting wall or a chamber wall.

18. The semiconductor processing system of claim 17, further comprising a liner and a mating fastener, wherein the liner is retained adjacent the mounting wall or the chamber wall by attaching the mating fastener to the captive fastener.

19. The semiconductor processing system of claim 16, wherein the component comprises a liner.

20. The semiconductor processing system of claim 19, further comprising a wall having a threaded hole, wherein the liner is held adjacent the wall by threading the captive fastener into the threaded hole.

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