ELECTROPLATING FIXTURES FOR LAMP HOUSING

BACKGROUND

Field

[0001]Embodiments of the present disclosure generally relate to an apparatus used in semiconductor processing. More specifically, embodiments disclosed herein relate to electroplating apparatuses used for components in semiconductor processing chambers.

Description of the Related Art

[0002]Rapid thermal processing (RTP) of semiconductor substrates provides a capability for better substrate-to-substrate process repeatability in a single-substrate lamp-heated thermal processing reactor. In semiconductor manufacturing, it is desirable to obtain temperature uniformity over the surface of each substrate during temperature cycling of substrates. Surface temperature uniformity provides uniform process variables (e.g., layer thickness, resistivity and etch depth) for various temperature-activated operations such as film deposition, oxide growth, and annealing. In addition, temperature uniformity is beneficial to prevent thermal stress-induced damage such as warpage, defect generation, and slip.

[0003]Radiant heating sources, such as lamps, are used to heat a substrate in the RTP chamber. Lamps are positioned in reflector housings in the RTP chamber. These housings include parts that are coated in metal to increase reflectivity.

[0004]Accordingly, there is a need for an improved methods and devices for coating parts in metal to increase reflectivity.

SUMMARY

[0005]In one embodiment, an electroplating device is provided. The electroplating device includes a housing including a first surface and a second surface and a plurality of holes disposed in the housing. The plurality of holes extend from the first surface to the second surface, and are configured to hold a component to be electroplated. The electroplating device further includes a gas inlet connected to an air bladder. The air bladder is disposed between the plurality of holes. The air bladder is configured to cover an outer surface of the component to be electroplated. The electroplating device further includes a cathode connector disposed below the first surface, and a cathode insert connected to the cathode connector. The cathode insert is connected to the plurality of holes and is configured to electrically charge the component.

[0006]In another embodiment, an electroplating device is provided. The electroplating device includes a housing comprising a first surface and a second surface and a plurality of holes disposed in the housing. The plurality of holes extend from the first surface to the second surface. The plurality of holes is configured to hold a component to be electroplated. The electroplating device further includes a plurality of O-rings disposed in the plurality of holes. The O-rings are configured to cover an outer surface of the component. The electroplating device further includes a cathode connector disposed below the first surface, and a cathode insert connected to the cathode connector. The cathode insert is connected to the plurality of holes and is configured to electrically charge the component.

[0007]In another embodiment, a method of electroplating a component. The method includes positioning a plurality of components in a plurality of holes of an electroplating device. The plurality of components include an outer surface, an inner surface opposite the outer surface, a top surface, and a bottom surface opposite the top surface. The method further includes sealing the plurality of components in the electroplating device. The outer surface, the top surface, and the bottom surface are covered by the electroplating device. The method further includes submerging the electroplating device in an electrolyte solution, electrically charging the electrolyte solution via a cathode and an anode disposed in the electroplating device, and electroplating the inner surface of the plurality of components.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008]So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only exemplary embodiments and are therefore not to be considered limiting of its scope, may admit to other equally effective embodiments.

[0009]FIG. 1A is a cross-sectional view of a reflector housing, according to embodiments.

[0010]FIG. 1B is an isometric view of a reflector housing, according to embodiments.

[0011]FIG. 2A is an isometric cross-sectional view of a masking fixture with a bladder, according to embodiments.

[0012]FIG. 2B is a cross-sectional view of the masking fixture with a reflector housing positioned inside, according to embodiments.

[0013]FIG. 3A is an isometric view of a masking fixture with an O-ring, according to embodiments.

[0014]FIG. 3B is a cross-sectional view of the masking fixture with a reflector housing positioned inside, according to embodiments.

[0015]FIG. 4 is a flow diagram of a method for electroplating a reflector housing, according to embodiments.

[0016]To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.

DETAILED DESCRIPTION

[0017]Embodiments of the present disclosure generally relate to an apparatus used in semiconductor processing. More specifically, embodiments disclosed herein relate to electroplating apparatuses used for components in semiconductor processing chambers.

[0018]FIG. 1A is a cross-sectional view of a reflector housing 100 (e.g. component). FIG. 1B is an isometric view of the reflector housing 100. The reflector housing 100 contains a first surface 101, a second surface 103, an inner surface 105, and an outer surface 107 forming a cylindrical body. The first surface 101 is opposite the second surface 103. The first surface 101 and the second surface 103 are flat disks. The inner surface 105 is opposite the outer surface 107. The inner surface 105 and outer surface 107 are cylindrical. The inner surface 105 has a first portion 109 and a second portion 111. The second portion 111 is angled.

[0019]The reflector housing 100 is configured to be positioned in a lamp housing. The reflector housing 100 may be part of a sleeve disposed within a lamp housing. Alternatively, reflector housing 100 may be an integral part of the lamp housing. The reflector housing reflects light from the lamps towards the processing volume in a processing chamber. The reflector housing 100 may be constructed from suitable materials with reflective surfaces, such as aluminum or a similar materials. In some embodiments, the aluminum is polished or machined to reduce a surface roughness of the aluminum. The reflector housing 100 may be plated with nickel on all surfaces. The nickel layer provides corrosion protection and structural rigidity to the reflector housing 100. The nickel layer has a thickness of about 10 microns to about 40 microns, such as about 20 microns to about 30 microns. After the nickel is coated on the reflector housing 100, in some embodiments, the nickel in the inner surface 105 is polished to remove surface scratches. The nickel is plated on the reflector housing 100 by an electroless or electrolytic process.

[0020]As the reflectivity of the surface of reflector housing 100 is increased, more energy is reflected from the lamps and towards a substrate in the processing chamber. To increase the reflectivity, the reflector housing 100 is coated with a reflective coating. The reflective coating may be gold, silver, nickel, aluminum or a similar material. The reflective coating prevents the reflector housing 100 from oxidizing and maintains a high level of reflectivity for the reflector housing 100. In various embodiments, the reflective coating is applied to the reflector housing via an electroplating process. The nickel layer described above is an under layer to the reflective coating. In embodiments having a gold reflective coating, the nickel layer provides beneficial properties to the reflective coating. In some embodiments, the inner surface 105 of the reflector housing 100 is additionally coated with a silicon oxide or ultraviolet (UV) enhanced coating. These coatings increase the damage resistance of the reflective coatings containing silver or aluminum.

[0021]One potential technique for electroplating the reflector housing 100 may include coating the first surface 101, the second surface 103, the inner surface 105, and the outer surface 107 of the reflector housing 100 with reflective material. However, due to the costs associated with coating surfaces of the reflector housing 100 with reflective materials (e.g., gold or silver), in various embodiments, only the inner surface 105 of the reflector housing 100 is coated with the reflective material. In such embodiments, the first surface 101, the second surface 103, and/or the outer surface 107 are not coated with the reflective material due to these surfaces being non-functional for reflecting, reducing material costs while still maintaining proper function in the reflector housing 100.

[0022]In various embodiments, in order to coat the inner surface 105 with the reflective material (while avoiding coating one or more other surfaces with the reflective material), the other surfaces of the reflector housing 100 may be masked. However, current masking techniques may not be beneficial due to throughput concerns and cost. For example, one masking technique includes taping the other surfaces of the reflector housing 100 or using liquid masking material commercially available for such purposes. Taping or using liquid masking has the downsides of each reflector housing 100 needing to be individually taped or masked (throughput concerns) and needing to tape or mask each uncoated surface (cost). To avoid these concerns, devices for masking need to be reusable and be able to electroplate multiple reflector housings 100 (e.g. components) at once. The disclosure provides for masking fixtures (e.g. electroplating devices) allowing for masking of several reflector housings at the same time. As described in further detail below, the masking fixtures allow for high throughput and cost-effective masking of the reflector housings. By not coating the other surfaces, the masking fixtures greatly reduces the amount of coating material (e.g. gold or silver) used in the electroplating process reducing the cost.

[0023]FIG. 2A is an isometric cross-sectional view of a masking fixture 200 (e.g. electroplating device). The masking fixture 200 contains a first fixture surface 201 and a second fixture surface 203. The second fixture surface 203 is opposite the first fixture surface 201. Sidewalls 205 connect the first fixture surface 201 to the second fixture surface 203. A plurality of holes 207 extend from the first fixture surface 201 to the second fixture surface 203. The holes 207 extend through an internal volume 208 defined by the first fixture surface 201, the second fixture surface 203, and the sidewalls 205. The holes 207 are configured to hold the reflector housings 100. A cathode connector 209 extends out of the sidewall 205 to connect to a power supply (e.g., a rectifier). The cathode connector 209 connects to each hole 207. An air bladder 211 is disposed in the internal volume 208. The air bladder 211 surrounds each of the holes 207. The air bladder 211 is fluidly connected to an air bladder inlet 213. The air bladder inlet 213 extends from the internal volume 208 through the sidewall 205. The air bladder is configured to be filled with a gas (e.g., compressed air).

[0024]The materials of parts of the masking fixture 200 vary. The first fixture surface 201, the second fixture surface 203, and the sidewalls 205 may include an insulator material such as plastics, elastomers, and ceramics. Plastics in the fluorocarbon family may be chosen due to cost and ease of manufacturing concerns. These plastics include Polytetrafluoroethylene (PTFE), Polyvinylidene fluoride (PVDF), Ethylene Tetrafluoroethylene (ETFE), ethylene-chlorotrifluoroethylene (ECTFE), Polychlorotrifluoroethylene (PCTFE), fluorinated ethylene propylene (FEP), and perfluoroalkoxy (PFA). Other plastics that may be used include Polyetherketoneketone (PEKK), polyaryletherketone (PAEK), Polyether ether ketone (PEEK), polyethylene terephthalate (PET), and Polypropylene (PP) or similar materials. Whereas, the cathode connector 209 may include a metal or metal alloy, such as titanium or copper. The cathode connector 209 is configured to provide electrons to the reflector housing 100 when the reflector housing 100 is electroplated and the material is selected to enhance electron transfer. In the internal volume 208, the air bladder 211 may include a molded elastomer or rubber. The air bladder 211 is configured to expand against the holes 207, securing the reflector housing 100 in the masking fixture 200. The air bladder inlet 213 expands the air bladder 211 by filling the air bladder 211 with a gas, such as compressed air.

[0025]FIG. 2B is a cross-sectional view of the masking fixture 200 with the reflector housing 100 positioned in the hole 207. The reflector housing 100 is electrically connected to the cathode connector 209 by a cathode insert 215. The cathode insert 215 supplies the reflector housing 100 with electrons that allow the reflector housing 100 to be electroplated. The cathode connector 209 is connected to the power supply to supply electrons to the cathode insert 215. The cathode insert 215 includes a metal or metal alloy, such as titanium or copper. The reflector housings 100 are inserted into the holes 207. The air bladder 211 is filled with air to secure the reflector housings 100 in the masking fixture 200. The air bladder 211 seals the outer surface 107. The cathode insert 215 seals the second surface 103. The first surface 101 is sealed by a plurality of cover rings 217 disposed in the plurality of holes 207 on the first surface 101 of the reflector housings 100.

[0026]An anode (not shown) may be inserted into an electrolyte solution with the masking fixture 200. The anode is an inert counter electrode to the cathode. The anode closes an electrical circuit in the electroplating process. The anode includes metals and metal alloys, such as titanium. The anode may be the anode described in FIG. 3A. In some embodiments, the anode is an external anode (e.g. a side wall of a bath used to hold an electrolyte solution for the electroplating process). During the electroplating process, the reflector housing 100 is secured in the masking fixture 200. The first surface 101, the second surface 103, and the outer surface are sealed off to prevent electroplating on these surfaces. The masking fixture 200 is disposed in the electrolyte solution. The electrolyte solution contains cations with the electroplating material. In some embodiments, the electroplating material is gold. When the electroplating material is gold, the electrolyte solution is selected to allow the gold electroplated layer to have the correct properties. The purity contributes to the reflectivity of the electroplated layer. The hardness contributes to the resistance to scratching of the electroplated layer. If the electroplated layer is intended to have different properties, then an electrolyte solution that provides a material other than gold may be selected to achieve those properties. The electrolyte solution includes ions of the material of the electroplate layer (e.g., gold ions). These ions are supplied to the electrolyte solution by dissolving salts into the electrolyte solution (e.g., gold salts).

[0027]As described above, the cathode connector 209 is connected to the power supply. The anode is also connected to the power supply. The power supply moves electrons from the anode to the cathode connector 209. From the cathode connector 209, the electrons are supplied to the reflector housing 100. The exposed surface of the reflector housing 100 (inner surface 105) with the additional electrons interacts with the electrolyte solution. The cations in the electrolyte solution are reduced by the electrons, forming a material layer e.g. electroplating the inner surface 105. In some embodiments, the inner surface 105 is electroplated with gold.

[0028]In some embodiments, the masking fixture 200 is used to electroplate other components besides the reflector housings 100. The other components may include brass or aluminum. When the other components are used, the other components include the nickel under layer and the reflective coating as described above for the reflector housing 100. The reflective coating includes the materials described above for the reflector housing 100. The other components may vary size. To fit the other components into the holes 207, the holes 207 of the masking fixture 200 are modified. Some components may be large enough for the masking fixture 200 to have only one hole 207 to cover the outer surface of one component. In some embodiments, the non-functional surfaces vary.

[0029]FIG. 3A is an isometric view of a masking fixture 300 (e.g. electroplating device). The masking fixture 300 is similar to the masking fixture 200 shown in FIGS. 2A and 2B. The masking fixture 300 contains a first fixture surface 301 and a second fixture surface 303. The second fixture surface 303 is opposite the first fixture surface 301. Sidewalls 305 connect the first fixture surface 301 to the second fixture surface 303. A plurality of holes 307 extend from the first fixture surface 301 to the second fixture surface 303. The holes 307 extend through an internal volume 308 defined by the first fixture surface 301, the second fixture surface 303, and the sidewalls 305. The holes 307 are configured to hold the reflector housings 100. The first fixture surface 301, the second fixture surface 303, and the sidewalls 305 may include an insulator material such as plastics, elastomers, and ceramics. Plastics in the fluorocarbon family may be chosen due to cost and ease of manufacturing concerns. These plastics include Polytetrafluoroethylene (PTFE), Polyvinylidene fluoride (PVDF), Ethylene Tetrafluoroethylene (ETFE), ethylene-chlorotrifluoroethylene (ECTFE), Polychlorotrifluoroethylene (PCTFE), fluorinated ethylene propylene (FEP), and perfluoroalkoxy (PFA). Other plastics that could be used include Polyetherketoneketone (PEKK), polyaryletherketone (PAEK), Polyether ether ketone (PEEK), polyethylene terephthalate (PET), and Polypropylene (PP) or similar materials. The holes 307 are defined by the internal volume 308. A sidewall of each hole 307 is formed from the non-reactive material of the internal volume 308. The non-reactive material may include polytetrafluoroethylene or a similar material. A cathode connector (not shown) extends out of the sidewall 305 to connect to a power supply. In some embodiments, the cathode connector is the cathode connector 209 shown in FIG. 2A. In other embodiments, a different cathode connector is used. The cathode connector connects to each hole 307.

[0030]During electroplating, an anode 309 will be inserted into an electrolyte solution with the masking fixture 300. The anode 309 connects to a power supply. As described in FIG. 2B, the anode 309 includes metals and metal alloys, such as titanium. The anode 309 is secured to the masking fixture 300 and branches out. The anode 309 extends into each hole 307 of the masking fixture 300. In some embodiments, a different anode is used with the masking fixture 300. For example, the anode may be an external anode (e.g., a side wall of a bath used to hold an electrolyte solution for the electroplating process).

[0031]FIG. 3B is a cross-sectional view of the masking fixture 300 with the reflector housing 100 positioned inside. The masking fixture 300 further includes a plurality of cathode inserts 315 and a plurality of O-rings 311 disposed in each hole 307. The O-rings include a fluorocarbon elastomer or a similar material. Fluorocarbon elastomers may include Fluorine Kautschuk Material (FKM) and perfluoroelastomer (FFKM). Each reflector housing 100 is electrically connected to the cathode connector 209 by a cathode insert 315. The cathode insert 315 supplies the reflector housing 100 with electrons that allow the reflector housing 100 to be electroplated. The cathode connector is connected to the power supply to supply electrons to the cathode insert 315. The cathode inserts 315 are positioned in the holes 307 above the second fixture surface 303. The reflector housings 100 are inserted into the holes 207. An O-ring of the plurality of O-rings 311 secures the reflector housing 100 in the masking fixture 300. The O-rings 311 are positioned substantially level with the first fixture surface 301 in each hole 307. The non-reactive material of the internal volume seals the outer surface 107. The cathode insert 315 seals the first surface 101. The second surface 103 is sealed by the O-ring 311. The O-rings 311 block the electrolyte solution from contacting the outer surface 107 of the plurality of reflector housings 100.

[0032]In some embodiments, the masking fixture 300 is used to electroplate other components besides the reflector housings 100. These other components may include brass or aluminum. The other components may include a nickel underlayer and the reflective coating as described above for the reflector housing 100. The reflective coating includes the materials described above for the reflector housing 100. The other components may vary size. To fit the other components into the holes 307, the holes 307 of the masking fixture 300 are modified. Some components may be large enough for the masking fixture 300 to have only one hole 307 to cover the outer surface of one component. In some embodiments, the non-functional surfaces vary.

[0033]FIG. 4 is a flow diagram of a method 400 for electroplating the reflector housing 100 using a masking fixture. In various embodiments, the masking fixture may be the masking fixture 200 or the masking fixture 300. Unless specified, the method 400 is described in conjunction with masking fixture 200 for illustration purposes.

[0034]At operation 401, a plurality of the reflector housings 100 are positioned in the masking fixture 200. An example of a reflector housing 100 is described in conjunction with FIGS. 1A and 1B. Each hole 207 is filled with the masking fixture 200.

[0035]At operation 403, the plurality of the reflector housings 100 are sealed in the masking fixture 200. In various embodiments, the masking fixture 200 can seal the first surface 101, the second surface 103, and the outer surface 107. In embodiments that implement the masking fixture 200, the reflector housing 100 is sealed by inflating the air bladder 211. The air bladder 211 covers the entire outer surface 107, preventing the metal containing electrolyte solution from contacting the outer surface 107. The first surface 101 is covered by the cover ring 217. The second surface 103 is covered by the cathode insert 215.

[0036]In embodiments that implement the masking fixture 300, the reflector housing 100 is sealed by the O-ring 311. The O-ring 311 prevents the metal containing electrolyte solution from contacting the outer surface 107. The outer surface 107 is covered by the non-reactive material of the internal volume 308. The first surface 101 is covered by the cathode insert 315. The cathode insert 315 seals the first surface 101. The second surface 103 is covered by the O-ring 311. The O-ring 311 seals the second surface 103.

[0037]At operation 405, the masking fixture 200 is submerged in the electrolyte solution. In various embodiments, the outer surface 107, first surface 101, and second surface 103 do not contact the electrolyte solution. While the outer surface 107, first surface 101, and second surface 103 are not contacted, the electrolyte solution covers the inner surface 105 of the reflector housing 100. The electrolyte solution contacts the inner surface 105 by filling the holes 207 of the masking fixture 200.

[0038]At operation 407, the electrolyte solution is electrically charged. The cathode connector 209 and the anode are connected to opposite sides of the power supply. The power supply transfers electrons from the anode to the cathode connector 209. The cathode connector 209 transports the electrons to the reflector housing 100, charging the inner surface 105.

[0039]At operation 409, the inner surface 105 of the reflector housing 100 is electroplated. The extra electrons in the reflector housing 100 attract cations from the electrolyte solution. The cations attach to the exposed inner surface 105. The cations then combine with the electrons, forming an electroplate layer (e.g., a reflective coating) on the inner surface 105. The cations in the electrolyte solution are replaced by adding metal salts (e.g., gold salts when forming the gold electroplate layer) to the electrolyte solution. In some embodiments, the electroplate layer is gold. In other embodiments, the electroplate layer is nickel, silver, or a similar material. The electroplate layer has a thickness of about 50 micro inches to about 500 micro inches, such as about 100 micro inches to 300 micro inches. Once the selected thickness of the electroplate layer is achieved, the cathode connector 209 and the anode are disconnected from the power supply, and the masking fixture 200 is removed from the electrolyte solution. Finally, the reflector housing 100 is removed from the masking fixture 200 with the inner surface 105 electroplated. In some embodiments, the inner surface 105 of the reflector housing 100 is additionally coated with a silicon oxide or UV enhanced coating. These coatings increase the damage resistance of the reflective coatings when the reflective coatings are silver or aluminum.

[0040]In summation, embodiments of the present disclosure generally relate to an apparatus used in semiconductor processing. More specifically, embodiments disclosed herein relate to electroplating apparatuses used in semiconductor processing chamber, such as reflector housings that are electroplated with a reflective material such as gold. While, conventionally, all surfaces of the reflective housings are coated, in various embodiments, only the inner surface may need to be coated. The reflective materials (e.g. gold) are expensive, so coating only the inner surface is beneficial. The outer surface, top surface, and bottom surface are covered by the masking fixture to prevent electroplating saving on cost of reflective material. The masking fixtures have the benefit of high throughput being a cost-effective masking technique. For example, the masking fixtures provided allow for masking of several reflector housings at the same time increasing the throughput. With regards to the cost, the masking fixture greatly reduces the amount of gold (or other reflective material) used in the electroplating process reducing the cost.

[0041]While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.