Active cooling of quartz-enclosed heaters during depressurization

Abstract

A heater assembly is disclosed that is effective in maintaining a heat lamp at an acceptable temperature. The heater assembly utilizes radiative heat transfer to transfer unwanted heat built up within the heat lamp to a cooling base. To facilitate heat transfer, one or more high emissivity films are disposed between the heat lamp and the cooling base. Additionally, a reflective coating is added to a portion of the heat lamp to reflect heat away from the cooling base. The heater assembly can be utilized in high vacuum environments because it does not rely on convection cooling.

Description

[Technical Field]

[0001] This application claims priority to U.S. Patent Application No. 17 / 583,755, filed January 25, 2022, the disclosure of which is incorporated herein by reference in its entirety.

[0002] SUMMARY OF THE INVENTION Embodiments of the present disclosure relate to an active cooling system for an infrared heater located within a vacuum. [Background technology]

[0003] The fabrication of semiconductor devices involves multiple separate and complex processes, and in certain processes it may be advantageous to perform one or more of these processes at elevated temperatures.

[0004] For example, different gases may be best ionized at different temperatures within an ion source. Larger molecules are preferably ionized at lower temperatures to ensure that larger molecular ions are produced. Other species may be best ionized at higher temperatures.

[0005] Additionally, certain implants and other processes are best performed at elevated temperatures.

[0006] These elevated temperatures can be achieved through the use of heaters. In some embodiments, the heaters can be located in a preheat station, which is used to raise the temperature of the workpieces prior to processing. In other embodiments, the heaters can be located in the end station of the beamline implant system.

[0007] Heaters often include components that have temperature thresholds below the target substrate temperature. In non-reduced pressure environments, these components are often kept within acceptable temperature limits by free or forced convection of atmospheric fluids. This method of heat dissipation is not available in reduced pressure environments.

[0008] Exceeding these temperatures can have deleterious effects. Specifically, in commercially available lamps, the halogen cycle typically has an optimal operating temperature range at the bulb surface between 250°C and 600°C; outside of this range, the halogen cycle breaks down and ultimately leads to lamp failure. Quartz glass, commonly used in infrared lamp construction, often has a threshold below 1000°C, which is often the upper glass temperature limit for halogen-free infrared lamps. Glass-to-metal seals for infrared lamps often have an upper allowable temperature limit between 300°C and 600°C.

[0009] Therefore, it would be advantageous to have a cooling system that utilizes other heat dissipation methods to maintain these sensitive heater components within acceptable temperature thresholds while operating at reduced pressure conditions, and it would be beneficial if this cooling system could be utilized in conjunction with existing heat lamps. Summary of the Invention

[0010] A heater assembly is disclosed that is effective for maintaining a heat lamp at an acceptable temperature under reduced pressure conditions. The heater assembly utilizes radiative heat transfer to transfer heat from the heat lamp to a cooling base. To facilitate heat transfer, one or more high-emissivity films are disposed between the heat lamp and the cooling base. Additionally, a reflective coating is added to a portion of the heat lamp to reflect heat away from the cooling base. Because the heater assembly does not rely on convective cooling, it can be used in high-vacuum environments.

[0011] According to one embodiment, a heater assembly is disclosed. The heater assembly includes one or more heat lamps, each having a filament enclosed within a tube, and a cooling base having one or more troughs. Each of the one or more heat lamps is disposed within a corresponding one of the one or more troughs. The area where the heat lamp contacts the corresponding trough is referred to as the contact area. The heater assembly further includes a reflective coating applied to the tube to reflect heat away from the contact area toward a target to be heated, and a high-emissivity film disposed between the one or more heat lamps and the corresponding trough at the contact area to enhance radiative heat transfer. In some embodiments, the high-emissivity film is applied to the cooling base within the one or more troughs, thereby positioning the reflective coating between the filament and the high-emissivity film. In some embodiments, the reflective coating is applied to the inner surface of the tube and the high-emissivity film is applied to the outer surface of the tube. In some embodiments, the reflective coating is applied to the outer surface of the tube and the high-emissivity film is applied over the reflective coating. In some embodiments, the cooling base includes a coolant inlet and a coolant outlet to allow coolant flow through the cooling base. In some embodiments, the cooling base includes an upper lamp housing attached to a lower cooling base. The trough is disposed within the upper lamp housing. In certain embodiments, one or more heat lamps are bonded to the cooling base. In some embodiments, the cooling base is made of quartz. In certain embodiments, no more than 50% of the outer surface of the tube contacts the corresponding trough. In some embodiments, the high-emissivity coating has an emissivity of at least 0.90.

[0012] According to another embodiment, an ion implantation system is disclosed that includes the heater assembly described above, an ion source, a mass analyzer, and an end station, wherein the heater assembly and the workpiece are disposed within the end station.

[0013] According to another embodiment, a heater assembly is disclosed. The heater assembly includes a heat lamp with one or more filaments enclosed within a housing, the housing having a bottom wall, multiple side walls, and a translucent surface; a cooling base having an upper surface, the bottom wall of the heat lamp being disposed above the top surface of the cooling base; a reflective coating applied to the bottom wall to direct heat away from the cooling base and toward the translucent surface and a target to be heated; and a high-emissivity film disposed between the heat lamp and the top surface of the cooling base to enhance radiative heat transfer. In some embodiments, the housing comprises a rectangular parallelepiped, a cylinder, or a tube. In some embodiments, the high-emissivity film is applied to the top surface of the cooling base. In certain embodiments, the reflective coating is applied to the inner surface of the bottom wall, and the high-emissivity film is applied to the outer surface of the bottom wall. In some embodiments, the reflective coating is applied to the outer surface of the bottom wall, and the high-emissivity film is applied over the reflective coating. In certain embodiments, the cooling base includes a coolant inlet and a coolant outlet to allow coolant flow through the cooling base. In some embodiments, the high emissivity coating has an emissivity of at least 0.90.

[0014] According to another embodiment, an ion implantation system is disclosed that includes the heater assembly described above, an ion source, a mass analyzer, and an end station, wherein the heater assembly and the workpiece are disposed within the end station.

[0015] For a better understanding of the present disclosure, reference is made to the accompanying drawings, which are incorporated herein by reference. [Brief explanation of the drawings]

[0016] [Figure 1A] 1A-1B illustrate a heat lamp and cooling system according to one embodiment. [Figure 1B] 1A-1B illustrate a heat lamp and cooling system according to one embodiment. [Figure 2]1 illustrates a heat lamp and cooling system according to another embodiment. [Figure 3A] 3A-3B show a cooling system according to another embodiment. [Figure 3B] 3A-3B show a cooling system according to another embodiment. [Figure 4A] 4A-4B show a cooling system holding multiple heat lamps according to one embodiment. [Figure 4B] 4A-4B show a cooling system holding multiple heat lamps according to one embodiment. [Figure 5A] 5A-5C show a heat lamp according to another embodiment. [Figure 5B] 5A-5C show a heat lamp according to another embodiment. [Figure 5C] 5A-5C show a heat lamp according to another embodiment. [Figure 6] 5C shows a heater assembly using a heat lamp as shown in FIG. 5C. [Figure 7] 1 illustrates an ion implantation system using a heater assembly as described herein. DETAILED DESCRIPTION OF THE INVENTION

[0017] As mentioned above, in certain embodiments, it is beneficial to process semiconductor processes at high temperatures, such as between 700°C and 1000°C or higher. Typically, this can be achieved through the use of heat lamps. These heat lamps emit infrared radiation and may be referred to as infrared heat lamps. These heat lamps may emit energy in specific spectra, such as short wave (SWIR), medium wave (MWIR), and long wave (LWIR). Other wavelengths can also be targeted by the heating system. However, as mentioned above, due to the reduced pressure conditions, it is difficult to cool the heat lamps, resulting in reduced lifetime and throughput. It would be beneficial to be able to effectively cool these heat lamps. This disclosure describes several embodiments of heater assemblies. The heater assemblies utilize radiative heat transfer to transfer heat from the heat lamps to a cooling base.

[0018] Figure 1A shows a heater assembly 10 including a heat lamp 20 and a cooling system 30 according to one embodiment. Figure 1B shows a cross-sectional view of the heater assembly 10.

[0019] Heat lamp 20 may be an infrared lamp having a filament 21 disposed within a tube 22, such as a quartz tube. Filament 21 extends from one end of tube 22 to the other end of tube 22. The diameter of tube 22 is not limited by this disclosure. Alternatively, heat lamp 20 may be a halogen lamp. Tube 22 is made of a transparent or translucent material, thereby allowing a majority of the heat and radiation emitted by the heat lamp to pass through tube 22.

[0020] In this embodiment, the cooling system 30 includes a cooling base 39 having a coolant inlet 35 and a coolant outlet 36. The cooling base 39 may be constructed of any suitable material, such as quartz or metal. Coolant is pumped into the cooling system 30 through the coolant inlet 35, and the warmed coolant exits the cooling system 30 through the coolant outlet 36. As best seen in FIG. 1B , the top surface of the cooling base 39 includes a trough 31. The trough 31 is sized so that the heat lamp 20 can be placed within the trough 31. In other words, the radius of curvature of the trough 31 is approximately equal to the outer diameter of the heat lamp 20. In this disclosure, the term "approximately equal" indicates that the radius of curvature of the trough 31 and the outer diameter of the heat lamp 20 differ by less than 10 thousandths of an inch.

[0021] In this configuration, a portion of the heat lamp 20 is in contact with the cooling base 39. In some embodiments, the trough 31 can be sized so that up to half of the outer surface of the tube 22 is in contact with the trough 31, as shown, for example, in FIG. 1B. Of course, the trough 31 may be configured so that a smaller percentage of the outer surface of the tube 22 is in contact with the trough 31. The area where the heat lamp 20 is in contact with the trough 31 is referred to as the contact area 32.

[0022] In certain embodiments, the heat lamp 20 is bonded directly to the cooling base 39. For example, if the cooling base 39 is quartz, the tube 22 and cooling base 39 may be bonded directly. Other types of glass-to-glass adhesives may also be used. However, in other embodiments, the components are not bonded together.

[0023] As shown in FIG. 1B , a high-emissivity film 33 is disposed between the heat lamp 20 and the trough 31 at the contact area 32. The high-emissivity film 33 may be a black film, black paint, or another suitable material. The high-emissivity film 33 may have an emissivity of at least 0.90 for most wavelengths in the wavelength range of interest. In this manner, the high-emissivity film 33 can achieve an emissivity close to that of a black body and maximize the potential for radiative heat transfer. In some embodiments, the high-emissivity film 33 may be disposed within the trough 31 of the cooling base 39. In some embodiments, the high-emissivity film 33 may be disposed on the outer surface of the tube 22, where it contacts the trough 31. In some embodiments, the high-emissivity film 33 may be disposed on the outer surface of the tube 22 and within the trough 31.

[0024] 1B, a high-emissivity film 33 may be disposed on a portion of the outer surface of the heat lamp 20 within the trough 31 and / or within the contact area 32. The high-emissivity film 33 allows for better cooling via radiative heat transfer between the heat lamp 20 and the cooling base 39.

[0025] The high-emissivity film 33 can be deposited by electroless deposition or various other deposition processes. Alternatively, the high-emissivity film 33 can be applied as an adhesive (sprayed or painted on) and heated to high temperatures until it bonds. In other embodiments, the high-emissivity film 33 can be sintered to the surface.

[0026] A reflective coating 34 is also applied to the heat lamp 20. The reflective coating 34 may have a reflectivity greater than 0.4. In certain embodiments, the reflective coating 34 may have a reflectivity greater than 0.5. In certain embodiments, the reflective coating 34 may have a reflectivity greater than 0.7. In certain embodiments, the reflective coating 34 may have a reflectivity greater than 0.9. The reflective coating 34 may be applied by deposition or some other method. The reflective coating may be gold, aluminum oxide, boron nitride, quartz, fused silica, or other suitable material. The reflective coating 34 is applied to the heat lamp 20 in a location such that the reflective coating 34 is between the filament 21 and the high-emissivity film 33. In one embodiment, the reflective coating 34 may be applied to the inner surface of the tube 22 in a region adjacent to the contact area 32 to reflect light away from the contact area 32 and through the tube toward the target being heated. In another embodiment, the reflective coating 34 may be applied to the outer surface of the tube 22 at the contact area 32.

[0027] The high-emissivity coating 33 is placed only on the surface where heat from the heat lamp is first reflected by the reflective coating 34. In other words, the reflective coating 34 can always be placed between the filament 21 and the high-emissivity coating 33.

[0028] In certain embodiments, a reflective coating 34 may be applied to the exterior surface of the tube 22. After the reflective coating 34 is applied, a high-emissivity film 33 may be applied over the reflective coating 34. In other embodiments, the reflective coating 34 is applied to the interior surface of the tube 22 and the high-emissivity film is disposed on the exterior surface of the tube 22. The reflective coating 34 may have a thickness between 1 and 10 thousandths of an inch depending on the type of material used.

[0029] In this manner, light within the heat lamp 20 first encounters the reflective coating 34, which reflects the light toward the target to be heated and away from the cooled base 39. Heat generated within the heat lamp 20 is transferred to the cooled base 39 via radiative heat transfer enabled by the high-emissivity coating 33. In this manner, the light output of the heat lamp 20 is maximized and heat is drawn away from the heat lamp 20.

[0030] Additionally, a reflective coating 34 may also be disposed on the top surface of the cooling base 39. Heat shields and / or other reflective surfaces may also be disposed to direct energy away from the cooling base 39 and contain only energy intended to be dissipated from the heat lamps 20.

[0031] 1A-1B show the cooling base 39 in the shape of a rectangular parallelepiped with a trough 31 on its upper surface. However, other shapes may also be used. For example, FIG. 2 shows the cooling base 39 as a cylinder with a trough 31 on its upper surface. Of course, the cooling base 39 may have other shapes as well.

[0032] In FIGS. 1A-1B and 2, the heat lamp 20 is in direct contact with the cooling base 39, which is an integral part. However, other embodiments are possible. FIGS. 3A-3B show a heater assembly in which the cooling base 39 comprises multiple components. The multiple components include a lower cooling base 38 and an upper lamp housing 37. FIG. 3B is a cross-sectional view of the heater assembly shown in FIG. 3A. The upper lamp housing 37 may have a trough on its upper surface. The upper lamp housing 37 may be made of a metal, such as aluminum. In other embodiments, the upper lamp housing 37 may be made of a different material. The lower surface of the upper lamp housing 37 may be flat. As described above, the trough may be coated with a high-emissivity film 33 to improve thermal conduction between the heat lamp 20 and the upper lamp housing 37. The lower cooling base 38 may have a flat upper surface that is adapted to contact the lower surface of the upper lamp housing 37.

[0033] In some embodiments, the heat lamps 20 may be bonded directly to the upper lamp housing 37. In other embodiments, the heat lamps are simply placed in a trough. The upper lamp housing 37 may be secured to the lower cooling base 38 using fasteners 50, such as screws. Additionally, vacuum compatible grease may be placed between the underside of the upper lamp housing 37 and the top surface of the lower cooling base 38 to facilitate heat transfer.

[0034] The cooling base 39 described above may dissipate heat by having a flow of coolant, such as a liquid or gas, through the cooling base, as shown in Figures 1A and 2. Alternatively or additionally, the cooling base 39 may include other features for dissipating heat, such as fins.

[0035] Additionally, while a single heat lamp is shown in the previous figures, multiple heat lamps may be utilized with a single cooling base. FIGS. 4A-4B illustrate a heater assembly with multiple heat lamps 20 disposed on a single cooling base 39. FIG. 4A is an exploded view, and FIG. 4B illustrates the heater assembly with the heat lamps 20 installed. In this embodiment, the upper lamp housing 37 has six troughs, which are used to hold the six heat lamps 20, as shown in FIG. 4B. The upper lamp housing 37 is attached to the lower cooling base 38, as described above. Additionally, a coolant inlet 35 and a coolant outlet 36 may be disposed within the lower cooling base 38.

[0036] In another embodiment, an integrated cooling base such as that shown in FIGS. 1A-1B can be expanded to include multiple troughs to support multiple heat lamps 20.

[0037] In each of these embodiments, the heater assembly includes one or more heat lamps 20 and a cooling base 39. The heat lamps may include a filament 21 enclosed within a tube 22, such as a quartz tube. A reflective coating 34 is applied to a portion of the tube 22 corresponding to the contact area 32. In some embodiments, the reflective coating 34 is applied to the inner surface of the tube 22 over a portion corresponding to the contact area 32. In some embodiments, the reflective coating 34 is applied to the outer surface of the tube 22 over a portion corresponding to the contact area 32. Additionally, the reflective coating 34 may be applied to the top surface of the cooling base 39 except within the contact area 32. A high-emissivity coating 33 is disposed between the outer surface of the tube 22 and the trough 31. In certain embodiments, the high-emissivity coating 33 is applied to the top surface of the trough 31. In some embodiments, the high-emissivity coating 33 is applied to the outer surface of the tube 22 at the contact area 32. In certain embodiments, the high-emissivity coating 33 is applied to both surfaces. Additionally, as mentioned above, in some embodiments, a reflective coating 34 is applied to the exterior surface of the tube 22 and a high-emissivity film 33 is disposed over the reflective coating 34 .

[0038] The above description discloses a cooling base 39 for use with one or more heat lamps in the form of a tube 22. However, other embodiments are possible.

[0039] 5A-5B show a heat lamp 60 formed as a housing 27 containing one or more filaments 21. The housing 27 may include a housing 23 and a translucent surface 24. The translucent surface 24 may be made of a transparent or translucent material, such as quartz. In this manner, a majority of the heat and radiation generated by the heat lamp 60 can pass through the translucent surface 24 and toward the target being heated. The housing 23 may be made of any suitable material, including metal. In some embodiments, the housing 23 is constructed of quartz. The housing 23 may include a bottom wall 25 and multiple side walls 26. In some embodiments, the housing 27, including the housing 23 and the translucent surface 24, may be a unitary piece. The housing 27 may be a rectangular parallelepiped, as shown in FIG. 6, or may have another shape. For example, a double-bore tube may be used.

[0040] The end of filament 21 can exit housing 23 through bottom wall 25, as shown in Figures 5A-5B. In other embodiments, the end of filament 21 can exit housing 23 through side wall 26, as shown in Figure 5C. Each end of filament 21 can exit housing 23 separately. In other embodiments, electrical connections to filament 21 can be made within housing 23 to reduce the number of external wires and glass-to-metal penetrations and seals.

[0041] A reflective coating 34 is applied to at least one surface of the housing 23. The reflective coating 34 may be applied to the bottom wall 25 of the housing 23. In some embodiments, the reflective coating 34 is applied to the inner surface of the bottom wall 25 of the housing 23. In other embodiments, if the housing 23 is quartz or another translucent material, the reflective coating is applied to the outer surface of the bottom wall 25 of the housing 23. In some embodiments, the reflective coating 34 may also be applied to one or more inner or outer surfaces of the side walls 26.

[0042] FIG. 6 shows a heater assembly including the heat lamp 60 of FIG. 5C and the cooling base 39. Note that a heater assembly can also be constructed using the heat lamp 60 of FIGS. 5A-5B. In FIG. 6, the cooling base 39 has an upper surface for contacting the lower wall 25 of the housing 27 of the heat lamp 60. If the lower wall 25 of the housing 23 is flat, the upper surface of the cooling base 39 can also be flat. If the outer surface of the lower wall is not planar, the upper surface of the cooling base 39 can have a similar contour for contacting the lower wall 25. In certain embodiments, these surfaces can be fused together. A high-emissivity film 33 can be disposed on the outer surface of the lower wall 25 in the contact area. Alternatively, or in addition, the high-emissivity film 33 can be disposed on the upper surface of the cooling base 39 in the contact area.

[0043] In some embodiments, a reflective coating 34 is applied to the exterior surface of the bottom wall 25. After this application, a high-emissivity film may be applied over the reflective coating 34 on the exterior surface of the bottom wall 25.

[0044] Although not shown, the cooling base 39 of FIG. 6 may have coolant inlets and coolant outlets similar to those shown in FIGS. 1A and 2.

[0045] Thus, in this embodiment, the heater assembly comprises a heat lamp including one or more filaments 21 disposed within a housing 27. The housing 27 may be shaped as a rectangular parallelepiped, a cylinder, or a tube, as is common for both lamps and heat exchangers. The housing 27 is made of a translucent surface 24 and a housing 23. A reflective coating 34 is applied to the surface of the lower wall of the housing 23. A high-emissivity film 33 is applied between the housing 23 and a cooling base 39. As mentioned above, the high-emissivity film 33 may be disposed on the outer surface of the lower wall 25 and / or the upper surface of the cooling base 39 in the contact area. The reflective coating may be applied to the inner or outer surface of the lower wall 25.

[0046] The heater assemblies described herein can be used in many applications. As shown in Figure 7, the heater assembly can be located in the end station of a beam-line implantation system. The beam-line ion implantation system can be used to process workpieces using a ribbon ion beam or a spot ion beam.

[0047] The beamline ion implantation system includes an ion source 100 comprising a plurality of chamber walls defining an ion source chamber. In certain embodiments, the ion source 100 may be an RF ion source. In this embodiment, an RF antenna may be positioned against a dielectric window. The dielectric window may comprise part or all of one of the chamber walls. The RF antenna may comprise a conductive material, such as copper. An RF power source is in electrical communication with the RF antenna. The RF power source may provide an RF voltage to the RF antenna. The power provided by the RF power source may be between 0.1 and 10 kW and any suitable frequency, such as between 1 and 100 MHz. Furthermore, the power provided by the RF power source may be pulsed.

[0048] In another embodiment, a cathode is positioned within the ion source chamber. A filament is positioned behind the cathode and is energized to emit electrons. These electrons are attracted to the cathode, which in turn emits electrons into the ion source chamber. This cathode may be referred to as an indirectly heated cathode (IHC) because it is indirectly heated by the electrons emitted from the filament.

[0049] Other embodiments are possible, for example, the plasma may be generated in different ways, such as by a Bernas ion source, a capacitively coupled plasma (CCP) source, a microwave ion source, or an electron-cyclotron-resonance (ECR) ion source, etc. The manner in which the plasma is generated is not limited by this disclosure.

[0050] One chamber wall, referred to as the extraction plate, includes an extraction aperture. The extraction aperture may be an opening through which ions 1 generated in the ion source chamber are extracted and directed to a workpiece 5. The workpiece 5 may be a silicon wafer or another wafer suitable for semiconductor manufacturing, such as GaAs, GaN, or GaP. The extraction aperture may be any suitable shape. In certain embodiments, the extraction aperture may be oval or rectangular, with one dimension, referred to as the width (x-dimension), being much larger than a second dimension, referred to as the height (y-dimension).

[0051] The extraction optics 110 are positioned outside and near the extraction aperture of the ion source 100. In certain embodiments, the extraction optics 110 include one or more electrodes. Each electrode may be a single conductive component with an aperture disposed therein. Alternatively, each electrode may be composed of two conductive components spaced apart to create an aperture between them. The electrodes may be a metal, such as tungsten, molybdenum, or titanium. One or more of the electrodes may be electrically grounded. In certain embodiments, one or more of the electrodes may be biased using an electrode power supply. The electrode power supply can be used to bias one or more of the electrodes relative to the ion source to attract ions through the extraction aperture. The extraction aperture and the aperture in the extraction optics are aligned so that ions 1 pass through both apertures.

[0052] Located downstream of the extraction optics 110 may be a first quadrupole lens 120. The first quadrupole lens 120 cooperates with other quadrupole lenses in the system to focus the ions 1 into an ion beam.

[0053] Located downstream of the first quadrupole lens 120 is the mass analyzer 130. The mass analyzer 130 uses a magnetic field to guide the path of the extracted ions 1. The magnetic field influences the flight path of the ions according to their mass and charge. A mass resolving device 150 having a resolving aperture 151 is located at the output (i.e., distal) end of the mass analyzer 130. By appropriately selecting the magnetic field, only ions 1 having a selected mass and charge will be guided through the resolving aperture 151. Other ions will collide with the walls of the mass resolving device 150 or the mass analyzer 130 and will be unable to travel further within the system.

[0054] A second quadrupole lens 140 may be positioned between the output of the mass analyzer 130 and the mass resolving device 150 .

[0055] A collimator 180 is positioned downstream from the mass resolving device 150. The collimator 180 accepts ions 1 that have passed through the resolving aperture 151 and produces a ribbon ion beam made up of multiple parallel or nearly parallel beamlets. The output side (i.e., distal end) of the mass analyzer 130 and the input side (i.e., proximal end) of the collimator 180 may be separated by a fixed distance. The mass resolving device 150 is positioned in the space between these two components.

[0056] A third quadrupole lens 160 may be disposed between the mass resolving device 150 and the input side of the collimator 180. A fourth quadrupole lens 170 may also be disposed between the mass resolving device 150 and the input side of the collimator 180.

[0057] In certain embodiments, the quadrupole lenses may be located in other positions, for example, the third quadrupole lens 160 may be located between the second quadrupole lens 140 and the mass resolving device 150. Furthermore, in certain embodiments, one or more of the quadrupole lenses may be omitted.

[0058] Downstream from the collimator 180, an acceleration / deceleration stage 190 may be located. The acceleration / deceleration stage 190 may be referred to as an energy purity module. An energy purity module is a beamline lens component configured to independently control the deflection, deceleration, and focusing of the ion beam. For example, the energy purity module may be a vertical electrostatic energy filter (VEEF) or an electrostatic filter (EF).

[0059] The ions 1 exit the acceleration / deceleration stage 190 as an ion beam 191 and enter the end station 200. The ion beam 191 may be a ribbon ion beam. A workpiece 5 is positioned within the end station 200.

[0060] The beamline ion implantation system therefore comprises several components that terminate in the end station 200. As discussed above, these components include the ion source 100, extraction optics 110, quadrupole lenses 120, 140, 160, 170, mass analyzer 130, mass resolving device 150, collimator 180, and acceleration / deceleration stage 190. It should be noted that one or more of these components may not be included within the beamline ion implantation system.

[0061] Additionally, while the above disclosure describes a ribbon ion beam having a width that is much greater than its height, other embodiments are possible. For example, a scanned spot beam may enter end station 200. A scanned spot beam is typically a circular ion beam that is scanned laterally to create the same effect as a ribbon ion beam.

[0062] Any of the heaters described herein may be disposed within the end station 200. In one embodiment, the heater assembly 10 is disposed in a position to heat the workpiece 5 when the workpiece is outside the path of the ion beam 191. In another embodiment, the heater assembly 10 may be disposed in a position configured to heat the workpiece 5 when the workpiece 5 is being implanted by the ion beam 191.

[0063] The present system has many advantages. The use of a reflective coating and a high-emissivity film allows the heat lamps to be maintained at a lower temperature than would otherwise occur in an isolated, reduced-pressure environment (with limited access to other cooling systems or methods). Specifically, the reflective coating reflects light into the chamber and away from the cooling base. Additionally, the use of a high-emissivity film allows for radiative heat transfer, which helps transfer heat from the heat lamps to the cooling base. The cooling base may be equipped with cooling channels and / or fins to allow heat dissipation.

[0064] The present disclosure is not limited in scope by the specific embodiments described herein. Indeed, various other embodiments and modifications of the present disclosure, in addition to those described herein, will be apparent to those skilled in the art from the foregoing description and accompanying drawings. Accordingly, such other embodiments and modifications are intended to be included within the scope of the present disclosure. Moreover, while the present disclosure has been described herein in the context of particular implementations in particular environments for particular purposes, those skilled in the art will recognize that its utility is not limited thereto, and that the present disclosure may be beneficially implemented in any number of environments for any number of purposes. Accordingly, the claims set forth below should be construed in accordance with the broadest possible scope and spirit of the disclosure as described herein.

Claims

1. one or more heat lamps, each heat lamp having a filament enclosed within a tube; a cooling base having one or more troughs, wherein each of the one or more heat lamps is disposed within a corresponding one of the one or more troughs, and an area where the heat lamp directly contacts the corresponding trough is referred to as a contact area; a reflective coating applied to the tube to reflect heat away from the contact area and toward a target to be heated; and a high-emissivity film positioned in direct contact with the one or more heat lamps and the corresponding troughs at the contact areas between the one or more heat lamps and the corresponding troughs to enhance radiant heat transfer.

2. 2. The heater assembly of claim 1, wherein the high-emissivity film is affixed to the cooling base within the one or more troughs such that the reflective coating is disposed between the filament and the high-emissivity film.

3. 2. The heater assembly of claim 1, wherein the reflective coating is applied to an inner surface of the tube and the high emissivity film is applied to an outer surface of the tube.

4. 2. The heater assembly of claim 1, wherein the reflective coating is applied to an exterior surface of the tube, and the high-emissivity film is applied over the reflective coating.

5. The heater assembly of claim 1 , wherein the cooling base comprises a coolant inlet and a coolant outlet to allow the flow of coolant through the cooling base.

6. 10. The heater assembly of claim 1, wherein the cooling base comprises an upper lamp housing attached to a lower cooling base, the trough being disposed within the upper lamp housing.

7. The heater assembly of claim 1 , wherein the one or more heat lamps are bonded to the cooling base.

8. The heater assembly of claim 7 , wherein the cooling base is made of quartz.

9. 10. The heater assembly of claim 1, wherein no more than 50% of the outer surface of said tube contacts said corresponding trough.

10. 10. The heater assembly of claim 1, wherein the high-emissivity film has an emissivity of at least 0.

90.

11. 10. An ion implantation system comprising the heater assembly of claim 1, an ion source, a mass analyzer, and an end station, wherein the heater assembly and workpiece are disposed within the end station.

12. A heat lamp comprising one or more filaments enclosed within a housing, the housing comprising a bottom wall, a plurality of side walls, and a translucent surface; a cooling base having a top surface, the bottom wall of the heat lamp being disposed on the top surface of the cooling base; a reflective coating applied to the bottom wall to direct heat away from the cooling base and towards the translucent surface and the target to be heated; and A heater assembly comprising a high-emissivity film disposed in a contact area between the heat lamp and the upper surface of the cooling base to enhance radiant heat transfer.

13. The heater assembly of claim 12 , wherein the housing comprises a rectangular parallelepiped, a cylinder, or a tube.

14. The heater assembly of claim 12 , wherein the high-emissivity film is applied to the top surface of the cooling base.

15. 13. The heater assembly of claim 12, wherein the reflective coating is applied to an inner surface of the bottom wall and the high emissivity film is applied to an outer surface of the bottom wall.

16. 13. The heater assembly of claim 12, wherein the reflective coating is applied to an outer surface of the bottom wall, and the high-emissivity film is applied over the reflective coating.

17. The heater assembly of claim 12 , wherein the cooling base comprises a coolant inlet and a coolant outlet to allow the flow of coolant through the cooling base.

18. 13. The heater assembly of claim 12, wherein the high emissivity film has an emissivity of at least 0.

90.

19. 13. An ion implantation system comprising the heater assembly of claim 12, an ion source, a mass analyzer, and an end station, wherein the heater assembly and workpiece are disposed within the end station.

20. A heater assembly as described in claim 1, wherein the high-emissivity film is applied to both the outer surface of the tube and the cooling base in the one or more troughs so that the reflective coating is positioned between the filament and the high-emissivity film.

21. The heater assembly of claim 12, wherein the heat lamp comprises two or more filaments.

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