ALUMINUM COATED OR CERAMIC PARTS FOR SUBSTRATE DRIVE
SYSTEM
BACKGROUND OF THE INVENTION Field of the Invention
[0001] Embodiments of the present invention generally relate to apparatus and methods for processing large area substrates. More particularly, embodiments of the present invention relate to apparatus and methods for cleaning substrate carriers and components in a large area substrate processing chamber.
Description of the Related Art
[0002] Fabrication of flat panel displays and solar panels usually includes depositing thin films on large area substrates. Thin films may be deposited by chemical vapor deposition processes, where chemical precursors are introduced to a processing chamber, chemically react to form a predetermined compound or material, and deposit onto a substrate positioned within the processing chamber. Substrate carriers are sometimes used in supporting large area substrates during processing and transferring large area substrates in and out processing chambers. During deposition processes, chemical precursors may react and form the thin films on the substrate carriers and chamber components in addition to the large area substrates. Thin film formation on substrate carriers and chamber components may cause particle contamination. Particle contamination may be reduced by cleaning chamber components with plasma. Traditional substrate carriers for large area substrates and chamber components for supporting and handling large are substrates are usually formed of stainless steel to obtain structural strength for supporting large area substrates. However, stainless steel is not compatible with cleaning plasma. As a result, traditional substrate carriers
and processing chambers for large area substrates may require open chamber manual cleaning, resulting in prolonged system downtime. Therefore, there is a need to clean substrate carrier and chamber components for processing large area substrates.
SUMMARY OF THE INVENTION
[0003] Embodiments of the present invention relate to a vertical processing system having chamber components that are compatible with cleaning plasma. Embodiments of the present invention also relate to a substrate carrier that can be plasma cleaned.
[0004] One embodiment of the present invention provides a substrate carrier. The substrate carrier comprises a frame body configured to receive and support a substrate therein. The frame body comprises a plurality of clamps for securing the substrate to the frame body. The substrate carrier also comprises an upper rail attached to the frame body. The upper rail comprises magnetizeable material, and outer surfaces of the frame body and the upper rail are compatible with cleaning plasma.
[0005] Another embodiment of the present invention provides an apparatus for processing large area substrates. The apparatus comprises a chamber body defining an inner volume, a plasma source disposed near a middle region of the inner volume dividing the inner volume into a first processing region and a second processing region. The apparatus also comprises a first linear roller track disposed in a lower portion of the first processing region for supporting and transporting a substrate carrier in a vertical orientation, a first magnetic rail disposed in an upper portion of the first processing region for guiding the substrate carrier supported on the first linear roller track in a vertical orientation, and a first backing plate movably disposed in the first processing region. The first backing plate is configured to attach to the substrate carrier on the first linear roller track to seal a back side of the substrate carrier. The apparatus also comprises a second linear roller
track disposed in a lower portion of the second processing region for supporting and transporting a substrate carrier in a vertical orientation, a second magnetic rail disposed in an upper portion of the first processing region for guiding the substrate carrier supported on the second linear roller track in a vertical orientation, and a second backing plate movably disposed in the second processing region. The second backing plate is configured to attach to the substrate carrier on the second linear roller track to seal a back side of the substrate carrier.
[0006] Another embodiment of the present invention provides a system layout for processing large area substrates. The system layout comprises an apparatus for processing large area substrates as disclosed in the previous embodiment, a first load lock chamber, a second load chamber, a first load/unload carriage movably attached to the first load lock chamber, and a second load/unload carriage movably attached to the second load chamber. The first load lock chamber is configured to load and unload substrate carriers to the first linear roller track of the apparatus, and the second load lock chamber is configured to load and unload substrate carriers to the second linear roller track of the apparatus.
[0007] Another embodiment of the present invention provides a method for plasma cleaning a carrier. The method comprises receiving a substrate carrier without a substrate in a processing chamber configured to process one or more large area substrates in vertical orientation, and generating a cleaning plasma in the processing chamber to clean the substrate carrier and inner surfaces of the processing chamber. According to one embodiment of the present invention surfaces of a backing plate configured to cover a back side of the substrate during deposition may also be plasma cleaned with the inner surfaces of the processing chamber. The backing plate may be spaced apart from the substrate carrier during plasma cleaning.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, 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 typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
[0009] Figure 1 is a plan view of a system layout according to one embodiment of the present invention.
[0010] Figure 2 is a sectional view of a chemical vapor deposition chamber according to one embodiment of the present invention.
[0011] Figures 3A-3F are schematic views of a substrate carrier according to one embodiment of the present invention.
[0012] 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 disclosed in one embodiment may be beneficially utilized on other embodiments without specific recitation.
DETAILED DESCRIPTION
[0013] Embodiments of the present invention relate to apparatus and methods for cleaning substrate carriers and components in a processing chamber. Particularly, embodiments of the present invention relate to processing chambers having chamber components that are compatible for plasma cleaning. Embodiments of the present invention also relate to substrate carriers that are compatible for plasma cleaning without a substrate.
A processing chamber according to embodiments of the present invention may include components that are encapsulated, coated or made with
materials compatible with cleaning plasma. A substrate carrier according to embodiments of the present invention may be formed by or coated with materials compatible with cleaning plasma. According to the embodiments of the present invention, plasma cleaning may be performed in a processing chamber having one or more substrate carriers without the presence of any substrates to clean the one or more substrate carriers and the chamber components.
[0014] Figure 1 is a plan view of a system layout 100 according to one embodiment of the present invention. The system layout 100 is configured to process large area substrates while positioning large area substrates in a substantially vertical orientation. The system layout 100 may be sized to process substrates having a surface area of greater than about 90,000 mm2.
[0015] The system layout 100 includes two loader/unloader carriages 102A, 102B, two load lock chambers 104A, 104B, and a processing chamber 106. The system layout 100 is configured to perform chemical vapor deposition on large area substrates. The load lock chambers 104A, 104B are used to exchange substrates between a vacuum environment in the processing chamber 106 and the loader/unloader carriages 102A, 102B positioned in the atmospheric environment.
[0016] The processing chamber 106 includes a plasma source 1 12 disposed near a middle of the processing chamber 106 dividing an inner volume of the processing chamber 106 into two symmetrical processing volumes 1 14A, 1 14B. The processing chamber 106 is configured to receive one substrate and process one substrate in each of the processing volumes 1 14A, 1 14B and process the two substrates simultaneously. The load lock chambers 104A, 104B are coupled to the dual processing chamber 106 through slit valve doors 1 1 OA, 1 10B respectively. Each load lock chamber 104A, 104B is configured to load and unload substrates in the corresponding processing volume 1 14A, 1 14B. The loader/unloader carriages 102A, 102B
are movably disposed next to the load lock chambers 104A, 104B on the opposite side of the processing chamber 106.
[0017] The loader/unloader carriages 102A, 102B include linear roller tracks 1 16A, 1 16B for supporting and moving substrates in vertical orientation in and out the lock load chambers 104A, 104B. Each load lock chamber 104A, 104B includes two sets of linear roller tracks 1 18A, 120A, 1 18B, 120B, each configured to support and move one substrate thereon. Two sets of linear roller tracks 1 18A, 1 18B allow the load lock chamber 104A, 104B to accommodate an incoming substrate and an outgoing substrate simultaneously. The processing chamber 106 includes linear roller tracks 122A, 122B in each processing volume 1 14A, 1 14B. The linear roller tracks 122A, 122B along the direction marked by arrows 124A, 124B to adjust the distance between the substrate being processed and the plasma source 1 12 during processing and to align with the linear tracks 1 18A, 120A, 1 18B, 120B during loading and unloading.
[0018] Figure 2 is a sectional view of the processing chamber 106 according to one embodiment of the present invention. The processing chamber 106 is configured to process large area substrates using plasma, such as plasma enhanced chemical vapor deposition.
[0019] The processing chamber 106 includes a chamber top 202, a chamber bottom 204, and chamber sidewalls 206 enclosing the inner volume
1 14. The chamber sidewalls 206 may be removably attached to a frame (not shown) for convenient removal and opening of the processing chamber 106 during chamber maintenance. The chamber top 202, chamber bottom 204 and chamber sidewalls 206 (only one shown) may have inner surfaces compatible with cleaning plasma, such as a NF3 plasma. The chamber top
202, chamber bottom 204 and chamber sidewalls 206 may be formed from aluminum. Alternatively, chamber top 202, chamber bottom 204 and chamber sidewalls 206 having a coating of aluminum, TEFLON®, or ceramics, such as a high purity aluminum oxide, in the inner surfaces. In one embodiment, the
chamber top 202, chamber bottom 204 and chamber sidewalls 206 may be coated by a high purity aluminum with a purity higher than 96%.
[0020] The plasma source 1 12 is coupled to the chamber top 202 and the chamber bottom 204 along a central plane 218 of the processing chamber 106. The plasma source 1 12 includes a plurality of pipes 210 vertically disposed in the inner volume 1 14 through the chamber top 202 and the chamber bottom 204. The plurality of pipes 210 may be formed from solid ceramic with perforations formed therethrough to allow passages of an excitant gas. The plurality of antennas 208 may be parallel to one another and evenly distributed along a length of the central plane 218. An antenna 208 is disposed in an inner volume 21 1 of each porous pipe 210. A plurality of end covers 212 are coupled to the pipes 210 outside the processing chamber 106 to seal the inner volumes 21 1 . A gas source 214 may be connected through the end covers 212 for providing an excitation gas to the inner volume 21 1 . Each antenna 208 may be coupled to a power source 216 for plasma generation. The power source 216 may be a radio frequency (RF) power source, very high frequency (VHF) power source, ultra high frequency (UHF) power source, or a microwave power to the antenna.
[0021] An excitation gas, such as Ar, Xe and/or Kr, may be supplied from the gas source 214 to the inner volume 21 1 , where plasma is generated by the power applied to the antenna 208. The radical species in the plasma then diffuse through the porous pipe 210 into the processing volumes 1 14A, 1 14B for processing.
[0022] A plurality of gas delivery tubes 222 are positioned in the processing volumes 1 14A, 1 14B for delivering one or more processing gases from a process gas source 220. The plurality of gas delivery tubes 222 may be evenly distributed in two planes parallel to the central plane 218 in the processing volumes 1 14A, 1 14B. The process gas source 220 may provide various process gases, such as SiH4, Si2H6 and NH3 for silicon nitride deposition. The process gas source 220 may also provide NF3 for plasma
cleaning. The gas delivery tubes 222 may be formed from aluminum or ceramic with a plurality of holes distributed along a gas distribution length 222A to allow processing gases to enter the processing volumes 1 14A, 1 14B to react with the diffused plasma from the plasma source 1 12. The pipes 210 of the plasma source 1 12 may be longer than the gas distribution length 222A of the gas delivery tubes 222. The gas distribution length 222A is generally longer than a length of the substrate 230. The differences among lengths of the pipes 210, the gas distribution lengths 222A, and the length of the substrate 230 provide improvement in particle performance and also increase efficiency in utilization of gases.
[0023] The processing chamber 106 includes two substrate support assemblies 224 disposed in the processing volumes 1 14A, 1 14B respectively. Each substrate support assembly 224 includes a plurality of rollers 226 disposed in a lower portion of the processing volume 1 14A or 1 14B. The plurality of rollers 226 are linearly arranged to form the linear roller track 122A, 122B. Each substrate support assembly 224 also includes a magnetic rail 232 disposed in an upper portion of the processing volumes 1 14A or 1 14B. The magnetic rail 232 and the plurality of rollers 226 are aligned to support and transfer a substrate carrier 228 in a vertical orientation. The substrate carrier 228 is configured to secure and support a substrate 230.
[0024] Each roller 226 may include a groove 240 for receiving a lower edge 242 of the substrate carrier 228. The lower edge 242 of the substrate carrier 228 contacts the rollers 226. Each roller 226 is coupled to a shaft 246. The shaft 246 extends through the chamber wall 206 and is connected to a drive mechanism 248 disposed outside the chamber wall 206. The drive mechanism 248 is configured to rotate the shafts 246 and the rollers 226 to move the substrate carrier 228 in and out the processing chamber 106. The drive mechanism 248 may also extend the shafts 246 further into the inner volume 1 14 and retract the shafts 246 from the inner volume 1 14 so that the rollers 226 move laterally together. The lateral movement of the rollers 226
may be used to align the rollers with the linear tracks 108A/108B or 1 1 OA/1 1 OB during loading and unloading. The lateral movement of the rollers 226 is also used to adjust the distance between the substrate 230 and the plasma source 1 12 during processing.
[0025] The magnetic rail 232 includes a downward facing trench 238 for receiving an upper rail 244 of the substrate carrier 228. The magnetic rail 232 may be formed by one or more magnets 234 encapsulated in a plasma compatible material 236. The one or more magnets 234 may be permanent magnets. The plasma compatible material 236 can withstand a cleaning plasma such as a NF3 plasma. The plasma compatible material 236 may be selected from different materials depending on the type of plasma. When a NF3 plasma is used, the plasma compatible material 236 may be aluminum, TEFLON®, or ceramics, such as high purity aluminum oxide (for example aluminum oxide having a purity greater than about 96%). The plasma compatible material 236 is shaped to form the trench 238 for receiving the substrate carrier 228. Alternatively, the magnet 234 may form the trench 238 and be coated with a plasma compatible material, such as aluminum, TEFLON®, or ceramics, such as high purity aluminum oxide (for example aluminum oxide having a purity greater than about 96%). The magnetic rail 232 is mounted on one or more shafts 250. The shafts 250 extend through the chamber wall 206 and connect to the drive mechanism 248. The drive mechanism 248 may extend and retract the shafts 250 in synchronization with the shafts 246 so that the magnetic rail 232 and the rollers 226 stay in the same plane. The upper rail 244 of the substrate carrier 228 includes material that can be magnetized so that the upper rail 244 is held within the magnetic rail 232 by repelling forces between the upper rail 244 and the magnets 234 without contacting the magnetic rail 232. The substrate carrier 228 moves relative to the magnetic rail 232 while the upper rail 244 is slides within the trench 238.
[0026] The rollers 226, the shafts 246 and the shafts 250 also have outer surfaces compatible with cleaning plasma, such as a NF3 plasma. The rollers 226, the shafts 246 and the shafts 250 may be formed from aluminum or ceramics. Alternatively, the rollers 226, the shafts 246 and the shafts 250 may include a coating of aluminum, TEFLON®, or ceramics, such as high purity aluminum oxide (for example aluminum oxide having a purity greater than about 96%). For example, the rollers 226, the shafts 246 and the shafts 250 may be formed from stainless steel coated with aluminum, TEFLON®, or ceramics, such as high purity aluminum oxide (for example aluminum oxide having a purity greater than about 96%).
[0027] The processing chamber 106 also includes a backing plate assembly 252 configured to cover a backside 230A of a substrate 230 to prevent unwanted deposition on the backside 230A during processing. The backing plate assembly 252 includes a planar plate 254 coupled to one or more beams 256 that support the planar plate 254 in a substantially vertical position. The planar plate 254 may be slightly larger in size than the substrate 230 being processed to completely cover the backside 230A of the substrate 230. The one or more beams 256 extend through the chamber wall 206 and connect to a driving mechanism 258. The driving mechanism 258 moves the planar plate 254 laterally by extending and retracting the one or more beams 256. The lateral movement allows the planar plate 254 to move up and become attached to the substrate carrier 228 during operation, and move away from the substrate carrier 228 during loading and unloading.
[0028] The planar plate 254 and the one or more beams 256 have outer surfaces compatible with cleaning plasma, such as a NF3 plasma. The planar plate 254 and the one or more beams 256 may be formed from aluminum or ceramics. Alternatively, the planar plate 254 and the one or more beams 256 may include a coating of aluminum, TEFLON®, or ceramics, such as high purity aluminum oxide (for example aluminum oxide having a purity greater than about 96%). For example, the planar plate 254 and the one or more
beams 256 may be formed from stainless steel coated with aluminum, TEFLON®, or ceramics, such as high purity aluminum oxide (for example aluminum oxide having a purity greater than about 96%).
[0029] Figures 3A-3F are schematic views of the substrate carrier 228 according to one embodiment of the present invention. The substrate carrier 228 is configured to transfer and support a large area substrate 230 during processing. The substrate carrier 228 has outer surfaces compatible with cleaning plasma, such as a NF3 plasma, such that the substrate carrier 228 can be cleaned using a plasma even without a substrate being loaded thereon. Plasma cleaning can remove any unwanted deposition formed on the substrate carrier during processing and reduce particle contamination caused by the unwanted deposition. Additionally, because the substrate carrier 228 can be cleaned by a plasma, there is no need to cover the substrate carrier 228 using a shadow frame as practiced in traditional large area substrate processing.
[0030] Figure 3A is a schematic view of the substrate carrier 228 showing a substrate loading side 312 of a frame body 302. During operation, the substrate loading side 312 faces away from processing environment, such as the plasma source and gas delivery pipes. The frame body 302 has four sections framing a rectangular inner opening 304 therein. The frame body 302 has a step 308 formed on the substrate loading side 312. The step 308 extends from the inner opening 304 to vertical walls 306. A plurality of contact pads 336 may be attached to the frame body 302 on the step 308. The contact pads 336 may be formed of TEFLON®. The vertical walls 306 form a rectangular form having a larger size than the substrate and the inner opening 304 is smaller in size that the substrate so that outer edges of the substrate rest on the plurality of contact pads 336 on the step 308. The inner opening 304 provides a window that exposes a processing area of the substrate while the frame body 302 covers the outer edges of the substrate. A plurality of clamps 316 are distributed around the frame body 302 on substrate loading
side 312. The plurality of clamps 316 are configured to bias the substrate against the step 308 to secure the substrate in the substrate carrier 228.
[0031] The upper rail 244 is attached to an upper section 302A of the frame body 302 through a plurality of connectors 314. The upper rail 244 includes materials that may be magnetized so that the substrate carrier 228 can be guided by a magnetic rail.
[0032] The lower edge 242 is coupled to a lower section 302B of the frame body 302. The lower edge 242 is configured to contact drive rollers in the processing chamber 106, the load lock chambers 104A, 104B, and the load/unload carriages 102A, 102B.
[0033] The substrate carrier 228 further includes a seal structure 330 attached to an outer edge of the frame body 302 on the substrate loading side 312. The seal structure 330 surrounds the vertical walls 306. During operation, a backing plate, such as the planar backing plate 254, may be in contact with the seal structure 330 and form a seal on the backside of the substrate secured in the substrate carrier 228 to prevent processing chemicals from contacting the backside of the substrate.
[0034] Figure 3B is a schematic sectional side view of the substrate carrier 228. As shown Figure 3B, the upper rail 244 may include a magnetizeable core 332 encapsulated in a plasma compatible material 334. The plasma compatible material 334 may include aluminum, TEFLON®, or ceramics, such as high purity aluminum oxide (for example aluminum oxide having a purity greater than about 96%). Figure 3C is a schematic view showing a processing side 310 of the frame body 302. The processing side 310 faces the processing environment, such as the plasma source and gas delivery pipes. The processing side 310 frames the substrate to expose only the area within the inner opening 304. The frame body 302 may function as a shadow frame preventing outer edges of the substrate from being processed.
[0035] The frame body 302, the connector 314, and the lower edge 242 have outer surfaces compatible with cleaning plasma, such as NF3 plasma. The frame body 302, the connector 314, and the lower edge 242 may be formed from aluminum or ceramics. Alternatively, the frame body 302, the connector 314, and the lower edge 242 may include a coating of aluminum, TEFLON®, or ceramics, such as high purity aluminum oxide (for example aluminum oxide having a purity greater than about 96%). For example, the frame body 302, the connector 314, and the lower edge 242 may be formed from stainless steel coated with aluminum, TEFLON®, or ceramics, such as high purity aluminum oxide (for example aluminum oxide having a purity greater than about 96%).
[0036] Figure 3D is a partial view of the substrate carrier 228 showing one of the clamps 316. Figure 3E is a partial sectional view of the substrate carrier 228 showing the clamp 316 securing a substrate 230 to a substrate carrier. Each of the plurality of clamps 316 is disposed in a recess 318 formed on the substrate loading side 312 of the frame body 302. The clamp 316 includes a clamp body 320 pivotable against a pivot axis 322. The clamp body 320 has a contacting end 324 and a free end 326 on opposite sides of the pivot axis 322. The clamp 316 also includes springs 328 biasing the contacting end 324 of the clamp body 320 towards the frame body 302. The springs 328 provide pressure on the contacting end 324 to push the substrate 230 against the frame body 302. Contact pads 325 may be attached on the contacting end 324 for contacting the substrate 230. The contact pads 325 may be formed of TEFLON®.
[0037] Figure 3E is a partial sectional view of the substrate carrier 228 showing the clamp 316 in a substrate loading/unloading position. To load or unload a substrate, an external force F may be applied, for example by a push pin, to the free end 326 of the clamp body 320. The clamp body 320 pivots about the pivot axis 322 and the contacting end 324 rotates away from the
substrate 230. The substrate 230 can then be released from the substrate carrier 228 and a new substrate may be loaded.
[0038] The clamp body 320 and the pivot axis 322 may have outer surfaces compatible with cleaning plasma, such as a NF3 plasma. The clamp body 320 and the pivot axis 322 may be formed from aluminum or ceramics. Alternatively, clamp body 320 and the pivot axis 322 may include a coating of aluminum, TEFLON®, or ceramics, such as high purity aluminum oxide (for example aluminum oxide having a purity greater than about 96%). For example, the clamp body 320 and the pivot axis 322 may be formed from stainless steel coated with aluminum, ceramic or TEFLON®.
[0039] The springs 328 are also formed with materials that are compatible with cleaning plasma, such as a NF3 plasma. For example, the springs 328 may be formed from super alloys, such as HASTELLOY®.
[0040] During operation, a substrate 230 to be processed may be loaded into substrate carriers 228 on the linear roller tracks 1 16A, 1 16B of the load/unload carriages 102A, 102B. The substrates 230 may be loaded into the substrate carrier 228 positioned on the steps 308 of the substrate carriers 228 by substrate transfer robots while all the clamps 316 are pushed in the loading/unloading position shown in Figure 3F. The substrates 230 are secured in the substrate carriers 228 when the clamp bodies 320 are released to their native positions.
[0041] The load/unload carriages 102A, 102B then moves to align the linear roller tracks 1 16A, 1 16B with the linear roller tracks 120A, 120B in the load lock chambers 104A, 104B. The linear roller tracks 1 18A, 1 18B are vacant. The substrate carriers 228 are then moved to the load lock chambers 104A, 104B on the linear roller tracks 120A, 120B respectively through the slit valve doors 108A, 108B. The slit valve doors 108A, 108B are then closed, and the load lock chambers 104A, 104B pumped down to the vacuum level of the processing chamber 106.
[0042] The slit valve doors 1 1 OA, 1 1 OB then open. The rollers 226 in the processing chamber are aligned with one of the vacant linear roller tracks 1 18A, 1 18B in the load lock chambers 104A, 104B. The rollers 226 then drive the already processed substrates from the processing chamber 106 to the load lock chambers 104A, 104B.
[0043] The rollers 226 in the processing chamber 106 then are aligned with one of the linear roller tracks 120A, 120B in the load lock chambers 104A, 104B, where each linear roller track 120A, 120B has a substrate 230 secured in a substrate carrier 228. The two substrates 230 secured in the substrate carriers 228 are then driven by the rollers in the load lock chambers 104A, 104B and rollers 226 in the processing chamber 106 and enter the processing volumes 1 14A, 1 14B. The lower edges 242 of the substrate carriers 228 rest on the rollers 226 and the upper rails 244 of the substrate carriers 228 are held in place in the magnetic rails 232. The shafts 246, 250 then move towards the plasma source 1 12 to position the substrates 230 in a processing position. The one or more beams 256 then extend into the through the chamber wall 206 to attach the backing plates 254 to the substrate carriers 228 to cover the backsides 230A of the substrates 230.
[0044] An excitation gas, such as Ar, Xe and/or Kr, are supplied from the gas source 214 to the inner volumes 21 1 of the pipes 210, where a plasma is generated by the power applied to the antenna 208. The radical spices in the plasma then diffuse through the pipes 210 into the processing volumes 1 14A, 1 14B for processing. One or more processing gases, such as SiH4, Si2H6 and NH3 are supplied to processing volumes 1 14A, 1 14B through the gas delivery tubes 222 and react with the plasma to deposit on the substrates 230 a thin film layer, such as a silicon nitride film.
[0045] After processing is completed, the one or more beams 256 retract to detach the backing plates 254 from the substrate carriers 228. The rollers 226 then retract and align the substrate carriers 228 with one of the vacant
linear roller tracks 1 18A, 1 18B in the load lock chambers 104A, 104B for unloading.
[0046] While substrates are processed in the processing chamber 106, the slit valve doors 1 1 OA, 1 1 OB close. The load lock chambers 104A, 104B then pressurize to atmospheric pressure. The slit valve doors 108A, 108B open to unload the substrate carriers 228 with processed substrates to the load/unload carriages 102A, 102B. In the load/unload carriages 102A, 102B, the processed substrates may be removed from the substrate carriers 228 and exit the system layout 100.
[0047] According to embodiments of the present invention, the substrate carriers 228 may then be sent back to the processing chamber 106 through the load lock chambers 104A, 104B without any substrates loaded therein. The empty substrate carriers 228 may be positioned by the rollers 226 in a processing position in the processing chamber 106. An excitation gas, such as Ar, Xe and/or Kr, are supplied from the gas source 214 to the inner volumes 21 1 of the pipes 210, where a plasma is generated by the power applied to the antenna 208. The radical spices in the plasma then diffuse through the pipes 210 into the processing volumes 1 14A, 1 14B for processing. A cleaning agent, such as NF3 is supplied to processing volumes 1 14A, 1 14B through the gas delivery tubes 222 and react with the plasma to clean the exposed surfaces of the processing chamber 106 and the substrate carriers 228.
[0048] In an exemplary cleaning process, substrate carriers 228 are loaded in the processing chamber 106 without any substrates 230 disposed thereon. The substrate carriers 228 may be moved towards the plasma source 1 12 to the processing position. The backing plates 254 may be moved towards the plasma source 1 12 without contacting the substrate carriers 228 such that the backing plates 254 can be exposed to cleaning plasma without blocking back sides of the substrate carriers 228.
[0049] The processing chamber 106 is then purged in preparation for plasma ignition. For example, argon may be flown into the processing volumes 1 14A, 1 14B at about 5SLM for about 5 seconds to achieve purging.
[0050] Plasma is then ignited in the processing chamber 106 using an excitation gas, such as argon. Argon may be flown to the processing chamber 106 from the gas source 214 at a flow rate between about 1 SLM to about 10SLM for at least 8 seconds while microwave power is applied to the antennas 208 to ignite a plasma of argon within the processing volumes 1 14A, 1 14B.
[0051] After the plasma is successfully ignited in the processing volumes 1 14A, 1 14B, a flow of cleaning gas, such as NF3, may be started while the flow of argon is maintained. The flow of NF3 may be gradually ramped up till the flow rate stabilizes.
[0052] Once the flow of NF3 is stabilized, the flow of argon may be ceased to begin full power plasma cleaning. The temperature within the processing volumes 1 14A, 1 14B may be maintained at about 100°C during plasma cleaning. The chamber pressure may be between about 20Torr to about 30 Torr. The flow rate of NF3 may be between about 20 SLM to about 30 SLM. Time duration for plasma cleaning depends on various factors, such as the size of the processing chamber 106, the desired amount to be etched, the flow rate of the cleaning gas, and the chamber pressure.
[0053] While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.