Method and apparatus for high temperature cleaning and maintenance of chambers and chamber components

Abstract

Examples disclosed herein relate to a method and apparatus for cleaning and repairing a substrate support having a heater disposed therein. The method includes (a) cleaning a surface of a substrate support having a bulk layer, the substrate support being disposed in a processing environment configured to process a substrate. The cleaning process includes forming a plasma from a cleaning gas mixture having a fluorine-containing gas and oxygen at an elevated temperature. The method includes (b) removing oxygen radicals from the processing environment with a processing plasma formed from the processing gas mixture. The processing gas mixture includes a fluorine-containing gas. The method further includes (c) repairing an interface between the substrate support and the bulk layer with a post-treatment plasma. The post-treatment plasma is formed from a post-treatment gas mixture including a nitrogen-containing gas. The elevated temperature is about 500 degrees Celsius or greater.

Description

[Technical Field]

[0001] Examples of the present disclosure generally relate to apparatus and methods for cleaning and maintaining a process chamber or components within the chamber, such as a heater located within a substrate support. [Background technology]

[0002] High device yields, along with a continuing increase in mean wafer-between-clean (MWBC) and a decrease in cost of ownership (CoO), are key requirements for high-volume manufacturing (HVM) of advanced semiconductors. Therefore, semiconductor processing tools require tighter control over particle defects and process stability or variability, as well as the useful life of chamber hardware. During chemical vapor deposition (CVD) processes, reactant gases can produce compositions that deposit on the interior surfaces of the chamber. As these deposits accumulate, these residues can flake off and contaminate future processing steps. Such residual deposits can further adversely affect other processing conditions, such as deposition uniformity, deposition rate, film stress, particle performance, and the like.

[0003] Therefore, processing chambers are periodically cleaned to remove residual materials. This cleaning process involves plasma-enhanced dry cleaning techniques. Etching agents, typically halogen- or oxygen-containing gases such as fluorine- or oxygen-containing gases, can react with the surfaces of chamber components, such as the substrate support, to form fluorides or oxides. In some applications, the substrate support is maintained at elevated temperatures, such as temperatures greater than 500 degrees Celsius. However, at these elevated temperatures, fluorides sublimate and condense on chamber components, such as the showerhead, that are at a lower temperature than the substrate support. This condensation can cause contamination of the substrate during the CVD process and can lead to changes in CVD process conditions, such as variations in deposition rate and uniformity.

[0004] Because fluorine (F) radicals from RPS or RF plasma attack conventional heater surfaces, such as AlN or Al2O3, conventional cleaning processes have temperature limits below approximately 500°C for carbon-based films and below approximately 570°C for Si-based films. F radicals can react with substrate supports, such as heater surfaces, sublimating at temperatures above approximately 500°C and then condensing or redepositing on cooler surfaces, such as faceplates and chamber walls. This results in process variations, particle problems, and therefore a significant reduction in MWBC and an increase in CoO. The substrate support can be coated with a thin ceramic coating that provides some resistance to cleaning gases. However, this coating can wear away when the substrate is placed on and removed from the substrate support. Furthermore, this coating can be susceptible to oxidation or can be degraded by radicals formed when the plasma deassociates the cleaning gas. Furthermore, the size and complexity of the substrate support and the edge ring, which may be attached to the substrate support, add time and cost to maintaining the ceramic coating on chamber components. Summary of the Invention [Problem to be solved by the invention]

[0005] Therefore, there is a need for improved methods and apparatus for performing high temperature cleaning of chambers and chamber parts and for protecting coatings on chamber parts. [Means for solving the problem]

[0006] Disclosed herein are methods and apparatus for cleaning chambers and chamber components, such as a substrate support. In one example, the method includes (a) cleaning a surface of a substrate support having a bulk layer disposed thereon. The substrate support is disposed in a processing environment configured to process a substrate. The cleaning process includes forming a plasma from a cleaning gas mixture at an elevated temperature, which may be the same as a film deposition temperature. The cleaning gas mixture includes a fluorine-containing gas and oxygen. The method includes (b) removing oxygen radicals from the processing environment using a processing plasma formed from the processing gas mixture at the elevated temperature. The processing gas mixture includes a fluorine-containing gas. The method further includes (c) maintaining, repairing, or restoring an interface between the substrate support and the bulk layer using a pre-treatment or post-treatment plasma at the elevated temperature. The pre-treatment or post-treatment plasma is formed from a nitrogen-containing gas mixture including a nitrogen-containing gas. The elevated temperature is about 500 degrees Celsius or greater.

[0007] In another example, a method for cleaning a substrate support includes (a) cleaning a surface of the substrate support having a bulk layer disposed thereon. The substrate support is disposed in a processing environment configured to process semiconductor substrates. The cleaning process includes forming a plasma from a cleaning gas mixture at an elevated temperature. The cleaning gas mixture includes NF3 and O2. The method further includes (b) removing oxygen radicals from the processing environment using a processing plasma formed from a processing gas mixture at the elevated temperature. The processing gas mixture includes NF3. The method then continues with (c) maintaining, repairing, or restoring an interface between the substrate support and the bulk layer using a pre- or post-treatment plasma at the elevated temperature. The pre- or post-treatment plasma is formed from a post-treatment nitrogen-containing gas mixture including N2. The elevated temperature is about 500 degrees Celsius or greater.

[0008] In yet another example, a semiconductor processing system includes a semiconductor processing chamber. The semiconductor processing system includes a non-transitory computer-readable medium having instructions stored thereon. When executed by a processor, the instructions cause a cleaning method to be performed within the semiconductor processing chamber. The method includes (a) cleaning a surface of the chamber and chamber components, such as a surface of a substrate support having a bulk layer disposed thereon. The substrate support is disposed within a processing environment configured to process semiconductor substrates. The cleaning process includes forming a plasma from a cleaning gas mixture at an elevated temperature. The cleaning gas mixture includes a fluorine-containing gas or an oxygen-containing gas, or any fluorine-containing and oxygen-containing gases mixed within the chamber. The method further includes (b) removing oxygen radicals from the processing environment using a processing plasma formed from the processing gas mixture at the elevated temperature. The processing gas mixture includes a fluorine-containing gas. The method further includes (c) maintaining, repairing, or restoring an interface between the substrate support and the bulk layer using a pre-treatment or post-treatment plasma at the elevated temperature. The pre-treatment or post-treatment plasma is formed from a post-treatment gas mixture including a nitrogen-containing gas. The elevated temperature is about 500 degrees Celsius or greater.

[0009] So that the above-listed features of the present disclosure can be understood in detail, the disclosure briefly outlined above may be more particularly described by reference to examples, some of which are illustrated in the accompanying drawings. It should be noted, however, that the accompanying drawings show only illustrative examples and therefore should not be considered as limiting the scope of the present disclosure, which may embrace other embodiments that are equally valid. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic cross-sectional side view of a processing chamber. [Figure 2A] 1 is a schematic side view of a substrate support having a bulk layer disposed thereon. [Figure 2B] 1 is a schematic side view of a substrate support having a bulk layer disposed thereon. [Figure 3A] 1A-1C are side views of the base and bulk layers of a substrate support during different stages of a cleaning method. [Figure 3B] 1A-1C are side views of the base and bulk layers of a substrate support during different stages of a cleaning method. [Figure 3C] 1A-1C are side views of the base and bulk layers of a substrate support during different stages of a cleaning method. [Figure 3D] 1A-1C are side views of the base and bulk layers of a substrate support during different stages of a cleaning method. [Figure 3E] 1A-1C are side views of the base and bulk layers of a substrate support during different stages of a cleaning method. [Figure 4] 4 is a flow chart illustrating a cleaning method relating to the steps shown in FIGS. 3A-E. DETAILED DESCRIPTION OF THE INVENTION

[0011] For ease of understanding, where possible, identical reference numerals have been used to designate identical elements common to the figures. It is contemplated that elements and features of one example may be beneficially incorporated into other examples unless specifically stated otherwise.

[0012] Examples of the present disclosure generally relate to methods and apparatus for cleaning chambers and chamber components, such as a substrate support. The substrate support may have a heater disposed therein. The substrate support is disposed in a processing chamber configured to process semiconductor substrates. In one example, the substrate support includes a heater coated with a bulk layer comprising a fluoride. Advantageously, the bulk layer does not react with cleaning species. Thus, the bulk layer protects the substrate support from reaction with the cleaning species, which reduces condensation formed on chamber components. As a result, the bulk layer reduces contamination of the substrate in subsequent processes and prevents changes or fluctuations in processing conditions.

[0013] Conventional cleaning methods and apparatus often result in the development of micro-voids and micro-fossires that develop into cracks that can damage the surface of the substrate support and propagate to the heater. Over multiple cleaning cycles, the cracks continue to grow within the heater, eventually connecting with each other and thus weakening the adhesion between the bulk layer and the heater near the crack. This localized loss of adhesion in conventional cleaning methods results in delamination of the bulk layer from the heater. Beneficially, the disclosed method reduces the formation of micro-fissures and voids that lead to cracks, thereby extending the life of the heater or other chamber components coated with a bulk layer. Other chamber components that can be adapted to benefit from the present disclosure include, among others, cover wafers or rings in process kits, such as edge rings.

[0014] In conventional cleaning processes using oxygen- or fluorine-based etchants, fluorine and oxygen radicals can damage aluminum-based heaters located within the substrate support. These fluorine and oxygen radicals can convert aluminum within the heater to AlF, which sublimes into the processing environment and redeposits on chamber components. Traditionally, processing environments for cleaning carbon-based residues have temperatures below 500°C, and for silicon-based films, temperatures below 570°C. Conventional cleaning processes and gases do not use high temperatures because they etch the heater and other chamber components. Left untreated, damage to the heater can cause changes in the impedance or capacitance of the substrate support, resulting in process variations or undesirable changes in the plasma profile across the substrate support, or can generate particles that reduce yield.

[0015] In one example of the present disclosure, the high-temperature method and apparatus are adapted to clean a substrate support having a carbon-based film or residue thereon. Fluorine-containing cleaning gases can be used for silicon-based residues, and oxygen-containing cleaning gases can be used to clean carbon-based residues. Advantageously, the method and apparatus herein enable operating temperatures greater than 500 degrees Celsius for carbon-based films and greater than about 570 degrees Celsius for silicon-based films, such as temperatures between about 600 degrees Celsius and about 1000 degrees Celsius and temperatures greater than 1000°C.

[0016] Fluorine or oxygen radicals generated in RF or RPS plasmas, or generated by thermal or laser energy, can diffuse through a bulk layer disposed on the heater. The bulk layer may be a MgF2 layer, such as an MgF2 layer. x The fluorine radicals react with aluminum-containing materials such as AlN in the heater. When reacted with fluorine, the aluminum in the heater becomes AlF x This AlF x The oxygen radicals diffuse through the bulk layer and sublimate into the processing environment of the processing chamber. The methods disclosed herein reduce or eliminate the reaction of fluorine radicals on the bulk layer covering the heater. The oxygen radicals react with MgF x Fluorine radicals can induce oxidation of the layer, thus forming MgO. x and AlN interface, and AlF x and nitric oxide (NO x ) can be formed. x and NO x When MgF diffuses out of the substrate support 104, xMicrovoids or fissures may appear at the interface between the bulk layer and the heater. Advantageously, this method reduces the "eat off" of AlN at the interface between the bulk layer and the heater, reducing the formation of microvoids and microfissures at this interface. The methods disclosed herein may also reduce cracks that form in the bulk layer. Cracks in the bulk layer may result from oxygen radicals interacting with fluorine-containing materials in the bulk layer. For example, oxygen radicals may interact with MgF x Therefore, after the cleaning process described above, a plasma formed from a nitrogen trifluoride (NF3) gas mixture treats the bulk layer. The treatment process and pre-treatment or post-treatment process can include etching, deposition, passivation, or any combination of these techniques to maintain, restore, or repair weak or deteriorated or damaged areas.

[0017] FIG. 1 is a schematic cross-sectional view of a processing chamber 100 according to one example described herein. The processing chamber 100 can be a plasma-enhanced CVD (PECVD) chamber or other plasma-enhanced processing chamber. An exemplary process chamber that can benefit from the examples described herein is the PRODUCER® series of PECVD-enabled chambers sold by Applied Materials, Inc. of Santa Clara, California. It is expected that other similarly equipped process chambers from other manufacturers can also benefit from the examples described herein. The processing chamber 100 includes a chamber body 102, a substrate support 104 disposed inside the chamber body 102, and a lid assembly 106 coupled to the chamber body 102 to enclose the substrate support 104 within a processing environment 120. The lid assembly 106 includes a gas distributor, such as a showerhead 112. A substrate 154 is provided to the processing environment 120 through an opening 126 formed in the chamber body 102. Although the disclosure herein is directed to discussing the substrate support 104, it is understood that the methods and apparatus may be applied to any chamber component having a bulk layer, as disclosed in detail below.

[0018] An isolator 110, which may be a dielectric material such as a ceramic or a metal oxide, for example, aluminum oxide and / or aluminum nitride, separates the showerhead 112 from the chamber body 102. The showerhead 112 includes openings 118 for admitting process or cleaning gases to the processing environment 120. These gases may be supplied to the process chamber 100 via conduits 114, where they may enter the gas mixing region 116 and then flow through the openings 118. An exhaust pipe 152 is formed in the chamber body 102 below the substrate support 104. The exhaust pipe 152 may be connected to a vacuum pump (not shown) to remove unreacted species and by-products from the processing chamber 100.

[0019] The showerhead 112 can be coupled to a power source 141, such as an RF generator or a DC power source. The DC power source can provide continuous and / or pulsed DC power to the showerhead 112. The RF generator can provide continuous and / or pulsed RF power to the showerhead 112. Additionally, as shown, a remote plasma source 174 can be coupled to the top, bottom, or side of the processing chamber 100. During operation, the power source 141 is turned on to provide power to the showerhead 112 to facilitate the formation of a plasma 160 within the processing environment 120. When exposed to the plasma 160, components from the processing gas, including ions, neutrons, protons, and radicals, are generated as the processing gas deassociates with the application of the RF generator or DC power source.

[0020] The substrate support 104 includes a surface 142 and a side 144 for supporting a substrate 154. In one example, the side 144 is substantially perpendicular to the surface 142. The substrate 154 has a dimension D1 (e.g., diameter), and the substrate support 104 has a dimension D2 (e.g., diameter) that is greater than the dimension D1. The substrate support 104 may be formed from a ceramic material, such as a metal oxide or nitride or oxide / nitride mixture, such as aluminum, aluminum oxide, aluminum nitride, or an aluminum oxide / aluminum nitride mixture. The substrate support 104 is supported by a shaft 143. The substrate support 104 may be grounded. A heating element 128 is embedded in the substrate support 104. The heating element 128 may be a plate, a perforated plate, a mesh, a wire screen, or any other distributed device. The heating element 128 is coupled to a power source 132 via a connection 130. The heating element 128 may heat the substrate support to an elevated temperature, such as a temperature greater than 500 degrees Celsius. No substrate 154 is present within processing environment 120 during application of the methods and apparatus disclosed herein.

[0021] 1 is shown in a lower position with a substrate 154 supported by a plurality of lift pins 140 extending through the substrate support 104. The substrate 154 can be placed on or removed from the lift pins 140 through the openings 126 by a robot (not shown). During operation, the substrate support 104 is raised to a higher position with the substrate 154 positioned on the surface 142.

[0022] During the cleaning process, the cleaning gas, e.g., a fluorine-containing gas or an oxygen-containing gas, may react with the substrate support 104 to form fluorides or oxides on the substrate support 104. The substrate support 104 is maintained at a temperature greater than 500 degrees Celsius. At these elevated temperatures, the fluorides or oxides sublimate and condense on cooler chamber parts, such as the showerhead 112. Oxides have high sublimation temperatures; for example, alumina (Al2O3) sublimes at temperatures between about 1150 degrees Celsius and about 1200 degrees Celsius. AlF x can be sublimated at temperatures above about 500 degrees Celsius. Condensation of material on the showerhead 112 can cause contamination of the substrate during subsequent processing. Therefore, a bulk layer 200 is utilized during application of the disclosed method and apparatus.

[0023] A purge gas source 170 is coupled to the chamber through one or more purge gas lines 172. As shown, the purge gas line 172 can extend through the chamber body 102 and can supply purge gas to the surface 142 of the substrate support 104. The purge gas line 172 can also extend through the shaft 143 and the substrate support 104. As such, the purge gas line 172 can supply purge gas to the surface 142 through the center of the substrate support 104 and / or through the edge of the substrate support 104 near the side cover 161.

[0024] At least one controller 162 is coupled to the processing chamber 100. The controller 162 includes a processor 164, a memory 166, and support circuits 168 coupled together. The processor 164 may be any form of general-purpose microprocessor or general-purpose central processing unit (CPU), such as a programmable logic controller (PLC), a supervisory control and data acquisition (SCADA) system, or other suitable industrial controller, each of which may be used in industrial equipment. The memory 166 is non-transitory and may be one or more of a readily available memory, local or remote, such as a random access memory (RAM), a read-only memory (ROM), or any other form of digital storage. The memory 166 includes instructions that, when executed by the processor 164, facilitate the execution of a method 400 (described below). The instructions in the memory 166 take the form of a program product, such as a program that implements the methods of the present disclosure. The program code of the program product may conform to any one of several different programming languages. Exemplary computer-readable storage media include, but are not limited to, (i) non-writable storage media having information permanently stored thereon (e.g., a read-only memory device within a computer such as a CD-ROM disk readable by a CD-ROM drive, flash memory, a ROM chip, or any type of solid-state non-volatile semiconductor memory), and (ii) writable storage media having changeable information stored thereon (e.g., a floppy disk or hard disk drive within a diskette drive, or any type of solid-state random access semiconductor memory). Such computer-readable storage media, when carrying computer-readable instructions that direct the functions of the methods described herein, are examples of the present disclosure.

[0025] 2A-2B are schematic side views of a substrate support 104 having a bulk layer 200 disposed thereon. The bulk layer 200 is disposed on a base 202 of the substrate support 104. The bulk layer 200 is a coating on the substrate support 104. As shown in FIG. 2A, the bulk layer 200 has a dimension D3, e.g., a diameter, that is the same as the dimension D2 of the substrate support 104. Thus, the bulk layer 200 covers the entire surface 142 of the substrate support 104. In some examples, the bulk layer 200 has a dimension, e.g., a diameter, that is smaller than the dimension D2 of the substrate support 104. For example, the dimension D2 can be the same as the dimension D1 of the substrate 154. In some examples, a portion of the surface 142 of the substrate support 104 may be exposed during the cleaning process.

[0026] The base 202 includes a first surface 206 in contact with the bulk layer 200, a second surface 208 opposite the first surface 206, and a third surface 210 connecting the first surface 206 and the second surface 208. The second surface 208 contacts the surface 142 of the substrate support 104 during the cleaning process. The first surface 206 of the base 202 may be smooth. The bulk layer 200 covers the first surface 206, the second surface 208, and the third surface 210 of the base 202. As mentioned above, in one example, the base 202 is a heating element 128 embedded in the substrate support 104.

[0027] 2B illustrates an alternative example of the substrate support 104 having a cover plate 212 and a bulk layer 200 disposed thereon. In some examples, the substrate support 104 includes a cover plate 212 and a side cover 161. In one example, all sides of the cover plate 212 are covered with the bulk layer 200. In another example, the cover plate 212 is made of the same material as the bulk layer 200, such that the cover plate 212 can be composed of one or more stacked bulk layers 200. The cover plate 212 covers a central portion of the surface 142, and the side cover 161 covers an edge portion and side 144 of the surface 142. Additionally, each surface of the side cover 161 can be covered with a bulk layer 200. As will be described in more detail below, the side cover 161 can remain in the processing chamber 100 during cleaning. Each of the cover plate 212 and / or the side cover 161 may be made from the same material as the bulk layer 200, or alternatively, may be made from the same material as the substrate support 104.

[0028] The bulk layer 200 can include a fluoride material such as magnesium fluoride (MgF) or a rare earth fluoride, such as yttrium fluoride (YF) or lanthanum fluoride (LaF). In one example, the bulk substrate support, including the heater, cover plate 212, and side cover 161, can be entirely made of a fluoride material having a thickness between about 500 μm and about 1500 μm. The fluoride material of the bulk layer 200 is exposed to the processing environment 120. In some examples, the fluorides are doped with dopants such as boron and / or carbon. The dopant concentration ranges from about 0 percent to about 50 percent, such as from about 10 percent to about 30 percent. In one example, the fluoride is LaF doped with boron and carbon (LaF(B,C)). The fluoride is substantially non-reactive with cleaning gases. Furthermore, the fluoride in the bulk layer 200 does not sublime at elevated temperatures, such as temperatures above 500° C. or above 1000° C., so that elemental fluorine does not significantly leave the bulk layer 200 and enter the surrounding environment during high-temperature cleaning. In one example, cleaning temperatures between about 500° C. and about 750° C., such as between about 500° C. and about 650° C., can be utilized, while these cleaning temperatures do not result in significant amounts of elemental fluorine leaving the bulk layer 200. In one example, the bulk layer 200 is MgF2, or a rare earth fluoride such as YF3, LaF3, or LaF3(B,C), having a thickness ranging from about 100 μm to about 3000 μm, such as from about 500 μm to about 1500 μm.

[0029] The base 202 may be fabricated from silicon (Si), silicon dioxide (SiO2), aluminum nitride (AlN), aluminum oxide (AlO), quartz, or other suitable materials. The base 202 may be fabricated by any suitable method, such as sintering. The base 202 has a thickness ranging from about 100 μm to about 3000 μm, such as from about 500 μm to about 1500 μm. The bulk layer 200 may be fabricated using any suitable method, such as CVD, crystal growth, or sintering. The bulk layer 200 may be fabricated by PVD, PECVD, ALD, ion-assisted deposition (IAD), plasma spraying, wet coating, implantation, or plasma or laser-based surface fluorination, boronization, and / or carbidization. The bulk layer 200 has a thickness ranging from about 1000 Å to about 10 μm, such as from about 5000 Å to about 1 μm. The bulk layer 200 is exposed to a processing environment 120 (shown in FIG. 1).

[0030] 3A illustrates a substrate support 104 disposed within a processing environment 120. The substrate support 104 is exposed to a cleaning plasma, such as plasma 160, generated from a cleaning gas mixture 301. As described above, the plasma 160 can be generated by an RF source (e.g., power source 141) or an RPS source 174. In one example, the bulk layer 200 includes a fluoride material, such as magnesium fluoride (MgF). The cleaning gas mixture 301 includes a fluorine-containing gas 304. In one example, the fluorine-containing gas 304 in the cleaning gas mixture 301 is NF3, which includes nitrogen atoms 306 and fluorine atoms 308 that diffuse into the bulk layer 200, through several micro-fisher holes 313, and into the heater 302. In the illustrated example, the heater 302 is made of an aluminum-containing material, such as aluminum nitride (AlN). The aluminum atoms 312 in the AlN react with the fluorine atoms 308 that diffuse through the microfissures 313 in the MgF2 bulk layer 200 to form aluminum fluoride (AlF x )310 or AlF x A gas phase 314 may form. AlFx The gas phase 314 diffuses out from the heater 302 and bulk layer 200 of the substrate support 104. x The gas phase 314 may be pumped out of the processing environment 120 or a portion may condense on cooler surfaces of the processing environment 120 .

[0031] In one example, when a carbon-based film or residue is present on the substrate support 104, the cleaning gas mixture 301 can be a combination of oxygen (O) and NF. In the presence of carbon, the cleaning gas mixture 301 can also be NF and N2O or N2. When the cleaning gas mixture 301 is being used to clean a carbon-based film or residue, oxygen radicals are controlled to a concentration that does not cause damaging oxidation on or attack the chamber parts. In another example, when a silicon-based film or residue is being deposited on the substrate support 104, the cleaning gas mixture 301 can include NF. The cleaning gas mixture 301 can also include N2, N2O, NH3, or Ar. The fluorine-containing gas 304 can include NF3, F2, SF6, and the like. Alternatively, the cleaning gas mixture 301 can include an oxygen-containing gas 320, such as oxygen, N2O, or CO2. In one example, if a silicon-based film or residue is present on the substrate support 104 and the heater 302 is made of AlN, the cleaning gas mixture 301 can include NF, N, or NH. In yet another example, if the heater 302 is made of AlO, the cleaning gas mixture 301 can include NF, N, O, or O.

[0032] As shown in FIG. 3B, a second cleaning gas mixture 303 containing oxygen (O) 320 is introduced into the processing environment 120. The substrate support 104 is exposed to a cleaning plasma, such as plasma 160, formed from the second cleaning gas mixture 303. Oxygen atoms 322 diffuse from the second cleaning gas mixture 303 into the bulk layer 200, forming a magnesium oxide (MgO) layer 316. A portion of the magnesium fluoride (MgF) in the bulk layer 200 is converted to magnesium oxide (MgO). As shown, the bulk layer 200 is left with an oxidized magnesium oxide (MgO x ) layer 316 and cleaning protection layer 318.

[0033] Alternatively, the oxygen in the second cleaning gas mixture 303 can include a nitrogen-containing gas 328. For example, in the presence of carbon-based films or residues, N2O or CO2 can be used instead of oxygen. Residual O2 radicals are reduced in the processing environment 120 during application of the second cleaning gas mixture 303. For an O2 cleaning process, AlN in the heater 302 converts to AlO. As AlO increases and AlN decreases, the thermal conductivity of the heater 302 decreases. AlO and AlN convert to AlF, and AlF x The gas phase 314 can be pumped out of the processing environment 120. Advantageously, the introduction of NF can remove oxygen radicals from the plasma, thereby reducing the amount of MgF x From MO x By reducing the conversion to magnesium fluoride (MgF x ) 321. Therefore, NF3 can reduce damage to the fluoromagnesium layer (MgF x ) 321. In another example, fluorine radicals are removed from the processing environment 120 when the second cleaning gas mixture 303 is applied to the processing environment 120 to clean silicon-based films or residues from the substrate support 104. In an example where the heater 302 is made of AlO, N or NH can be supplied to the second cleaning gas mixture 303.

[0034] FIG. 3C illustrates exposing the substrate support 104 to a post-treatment plasma (i.e., plasma 160) formed from a post-treatment gas mixture 305 that includes a fluorine-containing gas 304. In one example, the fluorine-containing gas 304 is NF3. Nitrogen atoms 306 and fluorine atoms 308 diffuse into the substrate support 104. The nitrogen atoms 306 and fluorine atoms 308 penetrate the magnesium oxide (MgO) layer 316 (shown in FIG. 3B) and the cleaning protective layer 318. The magnesium oxide (MgO) is then oxidized by the fluoromagnesium layer (MgF x ) 321, where x is an integer between 1 and 6. Aluminum oxide (AlO) 336 and aluminum nitride (AlN) 324 in the heater 302 are converted to aluminum monofluoride (AlF) 310. AlF x The gas phase 314 diffuses out from the heater 302 and exits the substrate support 104. In some instances, this gas phase may contain nitric oxide (NO ), for example, when cleaning a carbon-based film using an oxygen-containing gas. x ) may include a heater 302 and a fluoromagnesium layer (MgF x Porous grains 311 are formed at the interface between the heater 302 and the bulk layer 200, such as at the interface with porous fluoromagnesium (MgF x ) grains are connected to the heater 302 and the fluoromagnesium layer (MgF x 3C, the bulk layer 200 is covered with the cleaning protection layer and the fluoromagnesium layer (MgF x )321.

[0035] FIG. 3D illustrates a modification to the processing operation illustrated in FIG. 3B. In FIG. 3D, an enhanced process gas mixture 307 is provided to the processing environment 120. The substrate support 104 is exposed to an enhanced process plasma formed when the plasma 160 is exposed to the enhanced process gas mixture 307. The substrate support 104 is exposed to the process plasma formed from the enhanced process gas mixture 307. The enhanced process gas mixture 307 can include an oxygen-containing gas 320, a nitrous oxide-containing gas 326, or a nitrogen-containing gas 328, or any combination thereof. For example, the enhanced process gas mixture 307 can include only one of the oxygen-containing gas 320, the nitrous oxide-containing gas 326, or the nitrogen-containing gas 328. Alternatively, the enhanced process gas mixture 307 can include the oxygen-containing gas 320 and the nitrogen-containing gas 328. In another example, the enhanced process gas mixture 307 can include nitrous oxide. In yet another example, the enhanced process gas mixture 307 can be a nitrogen-containing gas 328. The nitrogen-containing gas 328 can actively suppress the effects of radicals formed by the RF or RP source. Exemplary plasma radicals include those formed when oxygen (O2) 320 or fluorine-containing gas 304 (e.g., NF3) disassociate in the plasma. The nitrogen-containing gas 328 protects the substrate support 104 and other components coated with the bulk layer 200. In some examples, the enhanced process gas mixture 307 is combined with the second cleaning gas mixture 303.

[0036] As mentioned above, a nitrous oxide-containing gas 326 can be used in place of the oxygen-containing gas 320 shown in FIG. 3B. In one example, the nitrous oxide-containing gas 326 is N2O, which reduces oxidation of the substrate support 104. Alternatively, nitrogen (N2) 328 and the oxygen-containing gas 320 can be added to the processing environment 120 to reduce surface oxidation of the substrate support 104. Advantageously, the presence of either nitrogen-containing gas, i.e., nitrogen (N2) 328 or the nitrous oxide-containing gas 326, increases the etch cleaning rate of the substrate support 104 and any surfaces covered by the bulk layer 200. Additionally, N2 or NH3 scavenges residual fluorine radicals, repairs aluminum dangling bonds, and promotes AlF x This reduces the conversion of AlN to AlN, thus protecting the interface between the heater 302 and the bulk layer 200 .

[0037] 3E illustrates a modification to the post-treatment operation illustrated in FIG. 3C. An enhanced post-treatment gas mixture 309 is provided to the processing environment 120, forming an enhanced post-treatment plasma 160. The substrate support 104 is exposed to the processing plasma formed from the enhanced post-treatment gas mixture 309. The enhanced post-treatment gas mixture 309 can include a fluorine-containing gas 304, a nitrogen-containing gas 328, an argon-containing gas 330, a hydrogen-containing gas 332, or any combination of two or more of these gases.

[0038] For example, the enhanced post-treatment gas mixture 309 can include a nitrogen-containing gas 328 and an argon-containing gas 330. The nitrogen-containing gas 328 can form a barrier layer 334 that inhibits oxidation of the heater 302. The barrier layer 334 further includes a passivated barrier layer formed on the internal microcrack surfaces and localized porous grains 311. During the treatment process shown in FIG. 3B or 3D, the argon-containing gas 330 can repair and substantially eliminate weak grain boundaries within the heater 302. In another example, the enhanced post-treatment gas mixture 309 can include a nitrogen-containing gas, a hydrogen-containing gas, or Ar gas to eliminate weak sites (i.e., grain boundaries) before the barrier layer 334 or passivated barrier layer is formed. For example, an NH3 or H2 plasma treatment can remove the oxidized layer through an oxidation-reduction reaction. The argon and additional gases in the enhanced post-treatment gas mixture 309 can treat the barrier layer 334, thereby increasing its resistance to oxygen and fluorine radicals.

[0039] In yet another example, the enhanced post-treatment gas mixture 309 includes a nitrogen-containing gas 328, an argon-containing gas 330, and a hydrogen-containing gas 332. In one example, the hydrogen-containing gas 332 is ammonium (NH). The enhanced post-treatment gas mixture 309 can enhance adhesion between the bulk layer 200 and the heater 302. The heater 302 (i.e., base) is disposed within the substrate support 104 with the bulk layer 200 disposed on top of and in contact with the heater 302. The protective layer 200 can include a cleaning protective layer 318, a fluoromagnesium layer (MgF x ) 321 and barrier layer 334. Alternatively, when nitrogen-containing gas 328 is added to the enhanced post-treatment gas mixture 309, cleaning protective layer 318, fluoromagnesium layer (MgF x ) 321 and barrier layer 334 may form bulk layer 200 .

[0040] FIG. 4 is a flow chart illustrating a method 400 for cleaning a chamber component. The chamber component may have a bulk layer 200 disposed thereon. The method 400 begins in operation 402 by performing a cleaning process in a processing chamber. The cleaning process may include flowing a cleaning gas, such as a fluorine-containing gas or an oxygen-containing gas, into the processing chamber. In some examples, the cleaning gas is first flowed into a remote plasma source (RPS) disposed above the processing chamber to form cleaning species, such as radicals, in the remote plasma source. The cleaning species are then flowed into the processing chamber to perform the cleaning process. The chamber component may be maintained at an elevated temperature, for example, between about 500 degrees Celsius and about 1000 degrees Celsius. Alternatively, the chamber component may be maintained at an elevated temperature between about 550 degrees Celsius and about 850 degrees Celsius, such as between about 650 degrees Celsius and about 700 degrees Celsius. Optionally, a purge process using argon or a nitrogen-containing gas, such as N2 or NH3, may be performed.

[0041] The cleaning gas or species removes residual materials accumulated on chamber components, such as the substrate support, showerhead, edge or shadow ring (not shown), and / or the chamber body. For example, the cleaning species can remove residual materials from the substrate support 104 and side cover 161, as shown in FIG. 1. The cleaning gas or species does not substantially react with the bulk layer, which protects the substrate support from the cleaning gas or species. In one example, as shown in FIG. 3A, the cleaning gas is a fluorine-containing gas 304. The cleaning gas can further include nitrogen (N2) 328 or a nitrous oxide-containing gas 326, as shown in FIG. 3D. In one example, nitrogen or argon can be introduced into the processing environment as a purge gas from a purge gas source 170. The introduction of nitrogen reduces surface oxidation of the substrate support by oxygen radicals. The nitrogen (N2) purge can actively suppress the effects of fluorine or oxygen radicals formed in the plasma. The N2 purge can suppress the negative effects of fluorine or oxygen radicals, especially when silicon-based and carbon-based films or residues are present on the substrate support 104. The N2 purge can be performed near the edge of the heater 302, at the center of the heater 302, or through the heater 302, and can be used to remove the fluoromagnesium layer (MgF x ) 321 from the processing environment 120. The Ar purge reduces the presence of fluorine radicals in the processing environment 120 when carbon-based films or residues are being deposited on the substrate support 104. When silicon-based films or residues are present on chamber components such as the substrate support 104, the Ar purge removes nitrogen, oxygen, or fluorine radicals from the processing environment 120. In yet another example, the Ar purge removes nitrogen oxides (NO x ) radicals are removed.

[0042] Method 400 includes several optional operations. At operation 404, an optional pretreatment process can be performed to substantially remove or eliminate the weak features and form a passivation barrier layer. At operation 406, an additional high-temperature plasma cleaning process can optionally be performed. For example, operation 402 can be repeated. The method can proceed to operation 408, where a second pretreatment process can optionally be performed to remove the weak features and form a passivation barrier layer.

[0043] In operation 410, the method 400 proceeds by performing a treatment process to remove oxygen radicals from the processing environment. This treatment process can be performed at an elevated temperature, such as the temperatures described above. As shown in FIGS. 3C and 3D, the substrate support 104 is exposed to a plasma formed from the post-treatment gas mixture 305 or the enhanced processing gas mixture 307. During operation 410, the processing gases diffusing from the post-treatment gas mixture 305 or the enhanced processing gas mixture 307 into the heater 302 reduce oxidation of the substrate support 104. A remote plasma source (RPS) can provide NF or O, individually or in combination, to a processing environment, such as processing environment 120. The location of the RPS can be coupled to the processing chamber at any location, such as the top, bottom, or center of the processing chamber 100.

[0044] In operation 412, an optional post-treatment process is performed. This post-treatment process is performed to restore or repair one or more damaged surfaces of one or more cleaned chamber components. The chamber components may be damaged by oxidation of the surfaces by radicals in the plasma. This post-treatment process is performed at an elevated temperature, such as the temperatures described above. A plasma is formed in the processing environment 120 by deassociating the post-treatment gas mixture 305 or the enhanced post-treatment gas mixture 309. As described above, the cleaning protective layer 318 and the fluoromagnesium layer (MgF) are formed when the post-treatment gas mixture 305 is provided to the processing environment 120. x) 321 forms the bulk layer 200. Alternatively, when an enhanced post-treatment gas mixture 309 is provided, a fluoromagnesium layer (MgF x ) 321 on which a fluoromagnesium layer (MgF x The barrier layer 334 may be formed in contact with the fluorine-containing layer 321. Therefore, the bulk layer 200 may be formed of the barrier layer 334, the magnesium fluoride layer (MgF x ) 321 and a cleaning protective layer 318. The enhanced post-treatment gas mixture 309 should reduce or eliminate the formation of localized porous grains 311. In one example, a fluoromagnesium layer (MgF x ) are formed in the bulk layer 200. In operation 410, the method 400 can be repeated until a desired level of deoxidation is reached in the heater 302 or in the porous grains 311 to be minimized or eliminated.

[0045] Disclosed herein are methods and apparatus for cleaning and optionally repairing or restoring process chamber components, such as a substrate support having a heater disposed therein. Advantageously, a bulk layer 200 fabricated from a fluoride material is utilized to protect the substrate support during the cleaning process. The fluoride-based bulk layer 200 does not substantially react with cleaning gases or species, and does not form products that can sublimate when the substrate support is maintained at elevated temperatures, which can be between about 500 degrees Celsius and about 1000 degrees Celsius. The foregoing is directed to examples of the present disclosure; however, other and additional examples of the present disclosure may be devised without departing from the basic scope thereof.

Claims

1. (a) cleaning a surface of a substrate support having a bulk layer disposed thereon, the substrate support being disposed in a processing environment configured to process a substrate, and the cleaning comprising forming a plasma from a cleaning gas mixture at an elevated temperature, the cleaning gas mixture comprising a fluorine-containing gas and oxygen; (b) removing oxygen radicals from the processing environment at the elevated temperature using a processing plasma formed from a processing gas mixture, the processing gas mixture including the fluorine-containing gas; and (c) repairing the interface between the substrate support and the bulk layer using a post-treatment plasma at the elevated temperature, wherein the post-treatment plasma is formed from a post-treatment gas mixture that includes a nitrogen-containing gas, and the elevated temperature is greater than or equal to about 500 degrees Celsius. Including, The method wherein the bulk layer comprises a fluoride material.

2. The method of claim 1 , wherein the bulk layer comprises magnesium fluoride or a rare earth fluoride.

3. The method of claim 1 , wherein the bulk layer comprises yttrium fluoride or lanthanum fluoride.

4. The fluorine-containing gas is NF 3 and the nitrogen-containing gas is N 2 The method of claim 1, wherein

5. (d) purging the processing environment with the nitrogen-containing gas or argon to reduce surface oxidation by the oxygen radicals, wherein the nitrogen-containing gas is N 2 or NH 3 That is, purging The method of claim 1 further comprising:

6. (d) adding NF to the processing environment along with the post-treatment gas mixture to enhance adhesion between the bulk layer and a base disposed with the substrate support. 3 , Ar or NH 3 To introduce The method of claim 1 further comprising:

7. (e) introducing an argon-containing gas into the processing environment along with the post-processing gas mixture; The method of claim 6 further comprising:

8. the substrate support Further comprising a base, wherein the base comprises silicon, silicon dioxide, aluminum nitride, aluminum oxide, or quartz; The method of claim 1.

9. 3. The method of claim 2, wherein the rare earth fluoride comprises yttrium fluoride or lanthanum fluoride, the lanthanum fluoride being doped with boron and / or carbon, and the base is a heater.

10. (a) cleaning a surface of a substrate support having a bulk layer disposed thereon, the substrate support being disposed in a processing environment configured to process a semiconductor substrate, the cleaning comprising forming a plasma from a cleaning gas mixture at an elevated temperature, the cleaning gas mixture comprising NF 3 and O 2 washing, including (b) removing oxygen radicals from the processing environment at the elevated temperature using a processing plasma formed from a processing gas mixture, the processing gas mixture being NF 3 including, removing, and (c) repairing the interface between the substrate support and the bulk layer at the elevated temperature using a post-treatment plasma, the post-treatment plasma comprising N 2 and the high temperature is greater than or equal to about 500 degrees Celsius. Including, The method wherein the bulk layer comprises a fluoride material.

11. The method of claim 10 , wherein the bulk layer comprises magnesium fluoride or a rare earth fluoride.

12. The method of claim 10 , wherein the bulk layer comprises yttrium fluoride or lanthanum fluoride.

13. further comprising a heater comprising aluminum, the heater contacting the bulk layer at the interface between the substrate support and the bulk layer. The method of claim 10.

14. (d) purging the processing environment with argon or a nitrogen-containing gas to reduce surface oxidation by the oxygen radicals, wherein the nitrogen-containing gas is N 2 Or NO 2 , N.H. 3 That is, purging The method of claim 10 further comprising:

15. (d) adding NF to the processing environment along with the post-treatment gas mixture to enhance adhesion between the bulk layer and a base disposed with the substrate support. 3 , Ar or NH 3 To introduce 15. The method of claim 14, further comprising:

16. (e) introducing an argon-containing gas into the processing environment along with the post-processing gas mixture; 16. The method of claim 15, further comprising:

17. a semiconductor processing chamber; a non-transitory computer readable medium having instructions stored thereon, the instructions, when executed by a processor, causing an etching method to be performed in the semiconductor processing chamber; and wherein the method comprises: (a) cleaning a surface of a substrate support having a bulk layer disposed thereon, the substrate support being disposed in a processing environment configured to process a semiconductor substrate, the cleaning comprising forming a plasma from a cleaning gas mixture at an elevated temperature, the cleaning gas mixture comprising a fluorine-containing gas and oxygen; (b) removing oxygen radicals from the processing environment at the elevated temperature using a processing plasma formed from a processing gas mixture, the processing gas mixture including the fluorine-containing gas; and (c) repairing the interface between the substrate support and the bulk layer using a post-treatment plasma at the elevated temperature, wherein the post-treatment plasma is formed from a post-treatment gas mixture that includes a nitrogen-containing gas, and the elevated temperature is greater than or equal to about 500 degrees Celsius. Including, The semiconductor processing system, wherein the bulk layer comprises a fluoride material.

18. (d) purging the processing environment with the nitrogen-containing gas to reduce surface oxidation by the oxygen radicals, the nitrogen-containing gas being N 2 or NH 3 That is, purging 20. The semiconductor processing system of claim 17, further comprising:

19. (d) adding NF to the processing environment along with the post-treatment gas mixture to enhance adhesion between the bulk layer and a base disposed with the substrate support. 3 , Ar or NH 3 and (e) introducing an argon-containing gas into the processing environment along with the post-processing gas mixture; 20. The semiconductor processing system of claim 17, further comprising:

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