Ash ratio recovery method in a plasma chamber

Abstract

A method of restoring an ash ratio in a plasma processing chamber includes positioning a substrate in a processing volume of the processing chamber, wherein the substrate has a silicon chlorides residue formed on the substrate. The method further includes evaporating the silicon chlorides residue from the substrate. The method further includes depositing the evaporated silicon chlorides on one or more interior surfaces in the processing volume. The method further includes exposing the deposited silicon chlorides to an oxidizing environment to convert the deposited silicon chlorides to a silicon oxide passivation layer. The oxidizing environment can include an oxygen-containing plasma, oxygen radicals, or a combination of the foregoing.

Description

Technical Field

[0001] The present invention relates generally to a method implemented in a semiconductor processing system, and more specifically to a method for increasing the service area of ​​a plasma processing chamber. Background Technology

[0002] The formation of integrated circuits involves the sequential formation or deposition of multiple conductive and insulating layers in or on a substrate. Etching processes can be used to form geometric patterns in the layers or vias for electrical contacts between layers. Typical etching processes include wet etching and dry etching (such as plasma etching), in which one or more chemical reagents come into direct contact with the substrate.

[0003] Various types of plasma etching processes include plasma etching, reactive ion etching, and reactive ion beam etching. In many of these processes, gas is first introduced into the reaction chamber through a gas distribution plate (GDP), and then plasma is generated from the gas. Ions, radicals, and electrons in the plasma chemically react with the layer material on the substrate to form residual products that remain on the substrate surface, thus etching material from the substrate. The gas distributed by the GDP not only provides a source of radicals and ions but can also be used to influence the lateral etching rate.

[0004] Before etching, the substrate is typically coated with a resist layer (e.g., photoresist), which is patterned, and this pattern is transferred to the underlying layer by etching—using the patterned resist layer as an etching mask. Many of these etching processes leave resist and etch residue on the substrate, which must be removed or stripped before the next processing step. One technique that has been used for photoresist stripping is plasma ashing.

[0005] During plasma ashing, plasma can be formed remotely or in situ. In remote or downstream plasma ashing, plasma is formed remotely, and gaseous radicals are delivered into the processing zone of the plasma chamber via a gas distribution plate. In in-situ plasma ashing, the processing gas enters the processing zone via a gas distribution plate, where plasma is then generated. The gas distribution plate in the plasma chamber can become gradually contaminated. For example, volatile reaction products and byproducts (e.g., refractory metals) coated on the gas distribution plate can create openings that obstruct gas flow. This leads to process drift and poor substrate repeatability. Furthermore, the volatiles and byproducts coated on the gas distribution plate promote oxygen recombination during the ashing process. As the contamination level of the gas distribution plate increases, the ash rate deteriorates accordingly. This deterioration can be as high as 90% and is often a limiting factor for the number of substrates that can be processed between cleanings of the gas distribution plate. Therefore, the reduced time between cleanings impacts yield and increases holding costs.

[0006] Cleaning gas distribution plates typically involve ramping up the chamber and removing the gas distribution plate for cleaning. However, this method is often very time-consuming because it involves breaking the vacuum, replacing the gas distribution plate, and ramping up the processing capacity to continue processing. One method to extend the time between cleanings is to supply cleaning gas through the gas distribution plate during a specific cleaning operation after one or more substrates have been processed. However, performing cleaning operations is time-consuming, during which substrates cannot be processed, and expensive, corrosive gases also attack and degrade chamber components. Therefore, the use of cleaning gas limits yield and processing output.

[0007] Therefore, there is a need to reduce contamination of chamber components (e.g., gas distribution plates). Summary of the Invention

[0008] This disclosure relates generally to a method implemented in a semiconductor processing system, and more specifically to a method for increasing the service area of ​​a plasma processing chamber.

[0009] In one aspect, a method is provided. The method includes positioning a substrate in a processing volume of a processing chamber, wherein the substrate has silicon chloride residue formed thereon. The method further includes evaporating the silicon chloride residue from the substrate. The method further includes depositing the evaporated silicon chloride on one or more internal surfaces of the processing volume. The method further includes exposing the deposited silicon chloride to an oxidizing environment to convert the deposited silicon chloride into a silicon oxide passivation layer.

[0010] The implementation may include one or more of the following: Evaporating silicon chloride residue from the substrate includes heating the substrate to a temperature of at least 200°C. The oxidizing environment includes oxidizing plasma, oxidizing reactants, or a combination of the foregoing. The oxidizing environment includes oxygen-containing plasma, oxygen radicals, or a combination of the foregoing. Oxygen radicals are formed by exciting a gas mixture including an oxygen-containing gas in a remote plasma chamber. The oxygen-containing gas includes an oxidant selected from oxygen, water vapor, ozone, nitrous oxide, or a combination of the foregoing. The gas mixture further includes an additive selected from nitrogen, argon, helium, or a combination of the foregoing. Evaporating silicon chloride residue from the substrate includes heating the substrate in a gas mixture of oxygen and nitrogen. Exposing the deposited silicon chloride to the oxidizing environment further includes maintaining the substrate at a temperature of at least 200°C. The oxygen to nitrogen flow ratio is about 10:1. At least a portion of one or more chamber surfaces has a refractory metal deposited thereon, and a silicon oxide passivation layer is formed over the refractory metal. The refractory metal is selected from tungsten and titanium. At least one of the one or more chamber surfaces is formed of aluminum, stainless steel, or a combination of the foregoing. One or more chamber surfaces include the surface of a gas distribution plate.

[0011] In another aspect, a method is provided. This method includes exposing a substrate having an exposed silicon-containing surface to an etching gas mixture including a chlorine-containing gas to form a silicon chloride residue on the exposed silicon-containing surface. The method further includes positioning the substrate within a processing volume of a plasma processing chamber. The method further includes heating the substrate to evaporate the silicon chloride residue from the exposed silicon-containing surface and depositing the silicon chloride residue on one or more inner chamber surfaces within the processing volume. The method further includes exposing the silicon chloride to an oxidizing environment to convert the silicon chloride residue, thereby forming a silicon oxide passivation layer above one or more inner surfaces within the processing volume of the plasma processing chamber.

[0012] The implementation may include one or more of the following: Evaporating silicon chloride residue from the substrate includes heating the substrate to a temperature of at least 200°C. The oxidizing environment includes oxidizing plasma, oxidizing reactants, or a combination of the foregoing. The oxidizing environment includes oxygen-containing plasma, oxygen radicals, or a combination of the foregoing. Oxygen radicals are formed by exciting a gas mixture including an oxygen-containing gas in a remote plasma chamber. The oxygen-containing gas includes an oxidant selected from oxygen, water vapor, ozone, nitrous oxide, or a combination of the foregoing. The gas mixture further includes an additive selected from nitrogen, argon, helium, or a combination of the foregoing. Evaporating silicon chloride residue from the substrate includes heating the substrate in a gas mixture of oxygen and nitrogen. Exposing the deposited silicon chloride to the oxidizing environment further includes maintaining the substrate at a temperature of at least 200°C. The oxygen to nitrogen flow ratio is about 10:1. At least a portion of one or more chamber surfaces has a refractory metal deposited thereon, and a silicon oxide passivation layer is formed over the refractory metal. The refractory metal is selected from tungsten and titanium. At least one of one or more chamber surfaces is formed of aluminum, stainless steel, or a combination of the foregoing. One or more chamber surfaces include the surface of a gas distribution plate.

[0013] In another aspect, a method is provided. This method includes positioning a substrate having an exposed silicon-containing surface in a first processing volume of a plasma processing chamber. The method further includes exposing the substrate to an etching gas mixture including a chlorine-containing gas to form silicon chloride residue on the exposed silicon-containing surface. The method further includes transferring the substrate to a second processing volume of a remote plasma processing chamber. The method further includes heating the substrate to evaporate the silicon chloride residue from the exposed silicon-containing surface onto a gas distribution plate positioned in the second processing volume. The method further includes exposing the silicon chloride residue on the gas distribution plate to an oxidizing environment to convert the silicon chloride residue, thereby forming a silicon oxide passivation layer over the gas distribution plate.

[0014] The implementation may include one or more of the following: Evaporating silicon chloride residue from the substrate includes heating the substrate to a temperature of at least 200°C. The oxidizing environment includes oxidizing plasma, oxidizing reactants, or a combination of the foregoing. The oxidizing environment includes oxygen-containing plasma, oxygen radicals, or a combination of the foregoing. Oxygen radicals are formed by exciting a gas mixture containing oxygen gas in a remote plasma chamber. The oxygen-containing gas includes an oxidant selected from oxygen, water vapor, ozone, nitrous oxide, or a combination of the foregoing. The gas mixture further includes an additive selected from nitrogen, argon, helium, or a combination of the foregoing. Evaporating silicon chloride residue from the substrate includes heating the substrate in a gas mixture of oxygen and nitrogen. Exposing the deposited silicon chloride to the oxidizing environment further includes maintaining the substrate at a temperature of at least 200°C. The oxygen to nitrogen flow ratio is about 10:1. At least a portion of one or more chamber surfaces has a refractory metal deposited thereon, and a silicon oxide passivation layer is formed over the refractory metal. The refractory metal is selected from tungsten and titanium. At least one of one or more chamber surfaces is formed of aluminum, stainless steel, or a combination of the foregoing. One or more chamber surfaces include the surface of a gas distribution plate.

[0015] In another aspect, a non-transient computer-readable medium has instructions stored thereon that, when executed by a processor, cause processing to perform the operations of the aforementioned devices and / or methods. Attached Figure Description

[0016] A more detailed description of the implementations briefly summarized above can be obtained by referring to some of the implementations illustrated in the accompanying drawings, thereby enabling a detailed understanding of the above-described features of the invention. However, it will be noted that the accompanying drawings illustrate only typical implementations of this disclosure and are therefore not intended to limit the scope of this disclosure, as other equivalent implementations are permissible.

[0017] Figure 1 A flowchart depicting a method for improving the ash ratio in a plasma processing chamber according to one or more implementations of this disclosure.

[0018] Figures 2A-2E A series of schematic cross-sectional views depicting an ash ratio recovery process according to one or more implementations of the present invention.

[0019] Figure 3 A schematic diagram depicting examples of plasma processing chambers that can be used in performing the methods described herein, according to one or more implementations of this disclosure.

[0020] Figure 4 A schematic plan view depicting an integrated processing system that can be used to perform the methods described herein, according to one or more implementations of the present invention.

[0021] Figure 5AIt is a drawing depicting the ash ratio behavior of the clean gas distribution plate versus the polluted gas distribution plate.

[0022] Figure 5B It is a plot depicting the ash ratio behavior of the polluted gas distribution plate on the gas distribution plate after treatment according to the method described herein.

[0023] For ease of understanding, the same reference numerals have been used as much as possible to refer to common components in the figures. Components and features of one implementation are conceived to be advantageously incorporated into other implementations without further explanation. Detailed Implementation

[0024] The instruction manual below describes a method for restoring the ash content in the plasma processing chamber. Some details are in the instruction manual below and... Figures 1-5B The description is provided to give a complete understanding of the various implementations of the invention. Further details of the well-known structures and systems typically associated with plasma ashing and plasma etching processes are not set forth in the description below to avoid unnecessarily obscuring the description of the various implementations.

[0025] The numerous details, dimensions, angles, and other features shown in the accompanying drawings are merely illustrative of a particular implementation. Therefore, other implementations may have different details, components, dimensions, angles, and features without departing from the spirit or scope of this disclosure. Furthermore, further implementations of the invention may be practiced without some of the features described below.

[0026] While no specific device is limited to which the implementation described herein can be performed, devices sold through Applied Materials Inc. in Santa Clara, California are permitted. ETCH system ETCH system, or Implementing this method in an AP system is particularly beneficial. Furthermore, other available etching systems can also benefit from the implementation described herein. The above list of semiconductor equipment is illustrative only, and other etching reactors and non-etching equipment (such as CVD reactors or other semiconductor processing equipment) can be appropriately modified in accordance with this teaching.

[0027] In some metal etching applications, metal stacks with photoresist and / or carbon masks formed thereon are etched in capacitively coupled or inductively coupled plasma chambers. The wafer then moves to a downstream plasma chamber where the photoresist and / or carbon mask are ashed by oxygen radicals. However, the gas distribution plate of the downstream plasma chamber often becomes contaminated with residual metal byproducts present on the wafer.

[0028] Currently, maintaining ashing performance in downstream plasma chambers is limited by wafer-free cleaning and the practical need to open the chamber to exchange contaminated parts. However, wafer-free cleaning using O2 / N2 / Ar gases often fails to remove accumulated metal byproducts, and exchanging chamber parts requires chamber downtime and lost throughput, for example, lasting 12 hours or longer in some cases.

[0029] In some implementations of this disclosure, a chlorine-based gas-based process is first used to etch a bare silicon wafer. This chlorine-based process causes the formation of silicon chloride (e.g., SiClx, where x = 1 to 4) byproduct fumes on the silicon wafer. The silicon wafer is then moved to a downstream plasma chamber where a high substrate temperature evaporates the SiClx byproduct fumes from the wafer surface and deposits the SiClx byproducts on a metal-contaminated surface of the chamber components (e.g., the surface of a gas distribution plate). The oxidizing environment in the downstream plasma chamber converts the silicon chloride byproducts into a silicon oxide (e.g., SiOx, where x = 1 to 2) layer, which forms above the metal-contaminated surface. After an ashing recovery process, the oxygen recombination rate becomes more similar to that of a clean gas distribution plate, and thus the ash content is restored. In some instances, by cycling 500 bare wafers through the ashing recovery process described herein, 90% of the original ash content can be restored compared to a clean gas distribution plate. Advantageously, the ashing recovery process of this disclosure restores the ash ratio by forming an in-situ silicon oxide layer above the contaminated chamber surface of a carrier wafer containing silicon chloride byproducts formed on the carrier wafer, which eliminates the need to open the chamber to exchange contaminated chamber parts.

[0030] Figure 1 A flowchart depicts a method 100 for improving the ash ratio in a plasma processing chamber according to one or more implementations of this disclosure. Figures 2A-2E A series of schematic cross-sectional views depicting one or more implementations of method 100 according to this disclosure. Although method 100 is related to... Figures 2A-2E In the context of forming a silicon oxide passivation layer over a contaminant (e.g., a metallic contaminant) formed on a gas distribution plate in a plasma processing chamber, it should be understood that method 100 can be used to form a silicon oxide passivation layer over other types of chamber components and in other types of processing chambers.

[0031] Method 100 begins operation 110 by positioning the substrate 210 within a first processing volume 212 defined by the first plasma processing chamber 214, as... Figure 2AAs shown. Substrate 210 has an exposed silicon-containing surface 216. Substrate 210 can be a semiconductor wafer. Substrate 210 can be a silicon wafer, for example, a 200-mm wafer, a 300-mm wafer, or a 450-mm wafer. The silicon-containing surface 216 can include materials such as bare silicon, silicon, strained silicon, amorphous silicon, doped silicon, doped amorphous silicon, polycrystalline silicon, or doped polycrystalline silicon. The first plasma processing chamber 214 can form at least one of inductively coupled plasma, capacitively coupled plasma, and remote plasma. In one example, the first plasma processing chamber 214 is available from Applied Materials, Inc., Santa Clara, California. Etching chamber. It is conceivable that other processing chambers, including those from other manufacturers, could also be adapted to implement the present disclosure.

[0032] Method 100 continues in operation 120, wherein substrate 210 is exposed to a chlorine-containing gas to form silicon chloride (SiClx) byproducts (e.g., silicon chloride residue) on the exposed silicon-containing surface 216, such as... Figure 2B As shown. The chlorine-containing gas can be chlorine (Cl2), boron trichloride (BCl3), a combination of the foregoing, etc. In one implementation, operation 120 provides chlorine at a rate from about 20 sccm to about 1,000 sccm (e.g., from about 40 sccm to about 200 sccm), optionally provides nitrogen (N2) at a rate from 0 sccm to 200 sccm, and optionally provides CF4 at a rate from about 0 sccm to about 100 sccm. Furthermore, operation 120 applies a plasma power from about 300 W to about 3,000 W (e.g., from about 400 W to about 1,000 W) and a bias power from about 0 W to about 500 W (e.g., from about 50 W to about 300 W), and maintains the substrate temperature from about 0 °C to about 200 °C and from about 20 °C to about 100 °C, and maintains the pressure in the reaction chamber from about 2 mTorr to about 300 mTorr (e.g., from about 10 mTorr to about 100 mTorr). In one example, Cl2 is provided at a rate of 100 sccm, N2 at a rate of 100 sccm, CF4 at a rate of 35 sccm, a plasma power of 700 W, a bias power of 100 W, a substrate temperature of 50 °C, and a pressure of 40 mTorr.

[0033] Method 100 continues in operation 130, wherein a substrate 210 having silicon chloride (SiClx) byproducts on an exposed silicon-containing surface 216 is transferred under vacuum to a second processing volume 222 defined by a second plasma processing chamber 224, as follows. Figure 2C As shown. In one example, a robot using an integrated processing platform (e.g., robot 430 of integrated processing system 400, such as...) is used in a vacuum. Figure 4 (As shown) Transfer substrate 210.

[0034] The second plasma processing chamber 224 may be configured to form at least one of inductively coupled plasma, capacitively coupled plasma, and remote plasma. The second plasma processing chamber 224 includes one or more internal surfaces, such as a gas distribution plate 226 positioned within the second processing volume 222. The one or more chamber surfaces may be formed of aluminum, stainless steel, quartz, or a combination of the foregoing. At least a portion of the one or more chamber surfaces has contaminants formed thereon. For example, the gas distribution plate 226 has a contaminant layer 228 formed thereon. In one example, the contaminant is a refractory metal selected from tungsten and titanium.

[0035] In one example, the second plasma processing chamber 224 is a remote plasma chamber, such as, for example, A chamber. A remote plasma reactor can be a plasma reactor in which radio frequency plasma is confined, allowing only reactive neutral particles to enter the processing volume of the processing chamber. This confinement scheme eliminates plasma-related damage to the substrate or circuitry formed on the substrate. Within the chamber, the back side of the substrate can be radiated by a quartz halogen lamp, resistively heated, or cooled by heat transfer (e.g., by circulating coolant through the wafer support), thereby maintaining the substrate temperature between 20°C and 450°C. Key features of the reactor are described below. Figure 3 Let me briefly describe it.

[0036] Method 100 continues in operation 140, wherein silicon chloride (SiClx) byproducts are evaporated from the exposed silicon-containing surface 216 of the substrate 210, as... Figure 2D As shown. In some implementations, evaporating the silicon chloride byproduct from substrate 210 includes heating substrate 210 to a temperature of at least 200°C. In one example, substrate 210 is heated to a temperature from about 200°C to about 300°C, for example, about 250°C. The evaporated silicon chloride (SiClx) byproduct is deposited above the surface of one or more chambers in the second processing volume 222. For example, as Figure 2D As shown, evaporated SiClx byproducts form above contaminant layer 228. In some implementations, operation 140 is performed in an oxygen-containing environment (e.g., a mixture of oxygen and nitrogen gases).

[0037] In some implementations, the substrate 210 is heated to approximately 250°C in a gas mixture containing oxygen (e.g., oxygen, ozone, water vapor, nitrous oxide (N₂O), nitrogen oxides (NO), nitrogen dioxide (NO₂), etc.) and optional additives (e.g., nitrogen, argon, helium, and the like). In one example, the gas mixture comprises oxygen and nitrogen. Oxygen and nitrogen can be supplied at a flow ratio from approximately 8:1 to approximately 12:1 (e.g., approximately 10:1). In one example, oxygen and nitrogen are supplied to the chamber at flow rates of approximately 5,000 sccm and approximately 500 sccm, respectively (e.g., at an O₂:N₂ flow ratio of approximately 10:1). Oxygen and nitrogen can be supplied at a pressure greater than 1 Torr for a duration of approximately 10-20 seconds.

[0038] Method 100 continues with operation 150, wherein the deposited silicon chloride is exposed to an oxidizing environment to convert the deposited silicon chloride into a silicon oxide passivation layer, such as Figure 2E As shown. The oxidizing environment may include, for example, oxidizing plasma, oxidizing reactants, or a combination of the foregoing. The oxidizing plasma may include oxygen-containing plasma. Oxidizing plasma can be formed "in situ" by exciting oxygen-containing gas within the processing volume. Oxidizing reactants may include, for example, oxygen radicals and / or oxygen ions. Oxidizing reactants may be part of a remote plasma. Oxidizing reactants may be formed from the source gas of the plasma source of a remote plasma reactor.

[0039] In some implementations, during operation 150, silicon chloride byproducts are exposed to an oxidation reaction product formed by a source gas from a plasma source of a remote plasma reactor (e.g., remote plasma source 306 of remote plasma processing system 300). A remotely generated oxidation plasma can be formed by supplying oxygen to the remote plasma source 306 via a mass flow controller, the remote plasma source 306 exciting oxygen into plasma. In some implementations, the remote plasma source 306 includes an ion filter that removes substances such as O2 from the plasma as it diffuses toward a gas mixing volume 322 defined by a gas distribution plate 320. + Oxygen ions. Therefore, primarily, neutral oxygen free radicals O * The activated oxidizing agent is delivered into the processing volume 324 of the processing chamber 302. Alternative neutral oxygen free radicals include O2. * The excited atomic states. Remote plasma sources may not be entirely efficient, so some neutral, unexcited O2 molecules may also reach the processing volume of 324. In other implementations, the oxidizing plasma includes both oxygen radicals and oxygen ions.

[0040] In one example, operation 150 provides a source gas comprising oxygen supplied at a flow rate of about 1,000 to about 9,000 sccm and nitrogen supplied at a flow rate of about 100 sccm to about 900 sccm, for example, an O2:N2 flow ratio of about 10:1. Further, operation 150 applies a power of about 3,000 W to about 5,000 W at a flow rate of about 200 kHz to about 600 kHz to form a remote plasma, while maintaining a substrate temperature of about 150°C to about 400°C and maintaining a gas pressure in the processing chamber of about 0.5 Torr to about 2 Torr. The duration of operation 150 may be generally about 15 seconds to 60 seconds.

[0041] In another example, operation 150 provides approximately 3,500 sccm of O2 and approximately 350 sccm of N2 (i.e., an O2:N2 flow ratio of approximately 10:1), approximately 5,000 W of plasma power, approximately 250 °C of substrate temperature, approximately 0.7 Torr of gas pressure, and a duration of, for example, 20 seconds.

[0042] In some implementations, the deposited passivation layer 230 is silicon dioxide (or a silicon dioxide-containing material). The oxidation plasma can be maintained until the passivation layer 230 is deposited to the target thickness, for example, from approximately... to approximately For example, from about to approximately

[0043] Method 100 can be performed periodically or at any desired interval, such as every 25 to 250 substrates (or 1 to 10 RF hours) during batch ashing, to improve consistency between operations without significantly impacting overall yield. The periodic performance of Method 100 has also been found to extend the yield limit of the ashing process to at least approximately 2,000 to 6,000 substrates continuously before a standard full chamber cleaning process is required.

[0044] Figure 3 A schematic diagram depicting an example of a remote plasma processing system 300 that can be used in a portion of performing method 100. For example, operations 140 and 150 can be performed in the remote plasma processing system 300. The remote plasma processing system 300 may be... The system is available from Applied Materials, Inc., Santa Clara, California. A specific implementation of the remote plasma processing system 300 is provided to illustrate this disclosure and should not be construed as limiting the scope of this disclosure. The remote plasma processing system 300 includes a processing chamber 302, a remote plasma source 306, and a system controller 308.

[0045] The processing chamber 302 is generally a vacuum container, comprising a first portion 310 and a second portion 312. In one implementation, the first portion 310 includes a substrate base 304, sidewalls 316, and a vacuum pump 314. The second portion 312 includes a cover 318 and a gas distribution plate (spray head) 320 defining a gas mixing volume 322 and a processing volume 324. The cover 318 and sidewalls 316 are generally formed of metal (e.g., aluminum (Al), stainless steel, etc.) and are electrically coupled to a ground reference 360.

[0046] A substrate base 304 supports a substrate (wafer) 326 within a processing volume 324. The substrate 326 may be a substrate 210 having silicon chloride residue formed on a substrate 210, as described herein. In one implementation, the substrate base 304 includes a radiant heat source (such as a gas-filled lamp 328) and an embedded resistive heater 330 with a conduit 332. The conduit 332 supplies cooling water from a source 334 to the back side of the substrate base 304. The substrate 326 rests on a surface 327 of the substrate base 304. Gas conduction transfers heat from the substrate base 304 to the substrate 326. The temperature of the substrate 326 can be controlled between approximately 20°C and 400°C.

[0047] Vacuum pump 314 is coupled to exhaust port 336 formed in the sidewall 316 or bottom wall 317 of processing chamber 302. Vacuum pump 314 is used to maintain the desired gas pressure in processing chamber 302 and to exhaust processed gases and other volatile compounds from processing chamber 302. In one implementation, vacuum pump 314 includes a throttle valve 338 to control the gas pressure in processing chamber 302.

[0048] The processing chamber 302 also includes conventional systems for holding and releasing the substrate 326, detecting the endpoint of the processing, internal diagnostics, etc. Such systems are depicted in a holistic manner. Figure 3 The 340 is used as a support system.

[0049] The remote plasma source 306 includes a power source 346, a gas panel 344, and a remote plasma chamber 342. In one implementation, the power source 346 includes a radio frequency (RF) generator 348, a tuning assembly 350, and an applicator 352. The RF generator 348 is capable of generating approximately 200 W to 6,000 W at frequencies from approximately 200 kHz to 600 kHz. The applicator 352 is inductively coupled to the remote plasma chamber 342 to inductively couple the RF power to a process gas (or gas mixture) 364 to form plasma 362 within the chamber. In this implementation, the remote plasma chamber 342 has a toroidal geometry that confines the plasma and promotes efficient generation of free radical matter and reduces the electron temperature of the plasma. In other implementations, the remote plasma source 306 may be a microwave plasma source.

[0050] Gas panel 344 uses conduit 366 to deliver process gas 364 to remote plasma chamber 342. Gas panel 344 (or conduit 366) may include a mass flow controller and shut-off valves to control the gas pressure and flow rate of the individual gases supplied to remote plasma chamber 342. In plasma 362, process gas 364 is ionized and dissociated to form reactants.

[0051] The reactants are guided into the gas mixing volume 322 through the inlet port 368 in the cover 318. In order to minimize charging plasma damage to the devices on the substrate 326, the ionic substances of the process gas 364 are substantially neutralized in the gas mixing volume 322 before the gas reaches the process volume 324 through the multiple openings 370 in the gas distribution plate 320.

[0052] System controller 308 includes a central processing unit (CPU) 354, memory 356, and support circuitry 358. CPU 354 can be any type of general-purpose computer processor used in industrial settings. Software programs can be stored in memory 356, such as random access memory, read-only memory, floppy disk or hard disk, or other forms of digital storage. Support circuitry 358 is conventionally coupled to CPU 354 and may include cache, clock circuitry, input / output subsystems, power supply, etc.

[0053] When executed by CPU 354, the software program transforms the CPU into a specific target computer (controller) 308, which controls the remote plasma processing system 300, causing the processing to be performed according to this disclosure. The software program may also be stored and / or executed by a remote second controller (not shown) located in the remote plasma processing system 300.

[0054] In operation, substrate 326 is positioned on substrate base 304 within processing volume 324 of processing chamber 302. Substrate 326 has silicon chloride (SiClx) residue formed thereon. Substrate 326 is heated using resistance heater 330 to evaporate the silicon chloride residue from substrate 326. The evaporated silicon chloride is deposited on gas distribution plate 320 within processing volume 324. Oxidation plasma is formed in remote plasma source 306, and oxidation reactants (e.g., oxygen radicals and / or oxygen ions) formed in remote plasma source 306 are delivered to processing volume 324 via gas distribution plate 320. The silicon chloride residue deposited on gas distribution plate 320 is exposed to an oxidizing environment to convert the deposited silicon chloride residue into a silicon oxide passivation layer formed on gas distribution plate 320.

[0055] Figure 4The image depicts a top plan view of an integrated processing system 400 that can be used in a portion of performing method 100. The integrated processing system 400 may be available from Applied Materials, Inc., Santa Clara, California. Integrated processing system. Specific implementations of the integrated processing system 400 are provided to illustrate this disclosure and should not be used to limit the scope of this disclosure.

[0056] The integrated processing system 400 generally includes a loading and locking chamber 422A, a loading and locking chamber 422B (collectively referred to as loading and locking chamber 422), a processing chamber 410, a processing chamber 412, a processing chamber 414, a processing chamber 416, a processing chamber 420, and a robot 430. The loading and locking chamber 422 protects the vacuum transfer chamber 428 of the integrated processing system 400 from atmospheric contaminants. The robot 430 uses blades 434 to transfer substrates between the loading and locking chamber 422 and the processing chambers. At least one of the processing chambers is a plasma etching chamber described above with respect to operations 110 and 120. Additionally, one or more processing chambers may be those described above with respect to operations 130-150 and... Figure 3 The described remote plasma chamber. Optionally, at least one of the processing chambers may be an annealing chamber or other heat treatment chamber. The integrated processing system 400 may also include other types of processing chambers and / or interfaces to the processing system. Furthermore, the integrated processing system 400 may include one or more external measurement chambers 418, which are connected to the integrated processing system 400 using, for example, a terminal 426 of a factory interface 424. The factory interface 424 is an atmospheric pressure interface used for transferring boxes containing pre-processed and post-processed wafers between various processing chambers and manufacturing areas in semiconductor manufacturing processes.

[0057] System controller 436 is coupled to and controls the modules of integrated processing system 400. Generally, system controller 436 controls all aspects of the operation of integrated processing system 400 using direct control of the modules and devices of integrated processing system 400, or by controlling the computers associated with these modules and devices. During operation, system controller 436 utilizes feedback from individual modules and devices to optimize substrate yield.

[0058] System controller 436 includes a central processing unit (CPU) 438, memory 440, and support circuitry 442. CPU 438 can be one of any type of general-purpose computer processor that can be used in an industrial setting. Support circuitry 442 is conventionally coupled to CPU 438 and may include cache, clock circuitry, input / output subsystems, power supply, etc. When executed by CPU 438, a software program transforms the CPU into a dedicated computer controller. The software program can also be stored and / or executed by a remote second controller (not shown) located in integrated processing system 400.

[0059] An example of a possible configuration of the integrated processing system 400 for removing halogen-containing residues according to this disclosure includes two loading locking chambers (chamber 422), PRECLEAN II TM Chamber (Cavity 410) Chamber (chamber 414), three The chambers (chambers 412, 416 and 420) and the measuring chamber (chamber 418).

[0060] Figure 5A This is a graph 510 depicting the ash ratio behavior of the clean gas distribution plate versus the contaminated gas distribution plate. As depicted in graph 510, the ash ratio of the contaminated gas distribution plate decreases significantly due to titanium contamination after 100 RF hours of production.

[0061] Figure 5B This is a graph 520 depicting the ash ratio behavior of a contaminated gas distribution plate relative to a gas distribution plate treated according to the method described herein. As depicted in graph 520, after exposing the contaminated gas distribution plate to the recovery method described herein for 3 RF hours, compared to Figure 5A The clean gas distribution plate shown is a restored gas distribution plate that has recovered almost 90% of its original ash content.

[0062] Implementations of this disclosure may include one or more of the following advantages. The ashing recovery process of this disclosure restores the ash ratio by forming an in-situ silicon oxide layer above the contaminated chamber surface on a carrier wafer containing silicon chloride byproducts or residues formed on the carrier wafer, eliminating the need to open the chamber to exchange contaminated chamber parts. This reduces chamber downtime and lost throughput, increasing the service range of the chamber.

[0063] The implementations and all functional operations described herein can be implemented in digital electronic circuits, or in computer software, firmware, or hardware, including the structural means and their equivalents disclosed herein, or combinations thereof. The implementations described herein can be implemented as one or more non-transitory computer program products (i.e., one or more computer programs tangibly embedded in a machine-readable storage device) for execution by a data processing device, or for controlling the operation of a data processing device such as a programmable processor, a computer, or multiple processors or computers.

[0064] The processing and logic flow described in this specification can be executed by one or more programmable processors, which implement one or more computer programs to perform functions by manipulating input data and producing outputs. This processing and logic flow can also be executed by dedicated logic circuitry, such as an FPGA (Field-Programmable Gate Array) or an ASIC (Application-Specific Integrated Circuit), and the device can also be implemented as dedicated logic circuitry, such as an FPGA or an ASIC.

[0065] The term "data processing device" encompasses all devices, apparatuses, and machines used for processing data, including, as examples, programmable processors, computers, or multiple processors or computers. In addition to hardware, this device may include code that creates the execution environment for the computer program in question, such as code that builds processor firmware, protocol stacks, database management systems, operating systems, or combinations of one or more of the foregoing. Processors suitable for executing computer programs include, as examples, both general-purpose microprocessors and special-purpose microprocessors, as well as any type of digital computer and one or more processors.

[0066] Computer-readable media suitable for storing computer program instructions and data include all forms of non-volatile memory, media, and memory devices, including, for example, semiconductor memory devices such as EPROM, EEPROM, and flash memory devices; magnetic disks, such as internal hard disks or removable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks. This processor and memory may be supplemented by or incorporated into dedicated logic circuitry.

[0067] When referring to a component of this disclosure or an example aspect or its implementation, the articles “a,” “an,” “the,” and “said” are intended to indicate the presence of one or more of this component.

[0068] The terms “contains,” “includes,” and “have” are intended to be inclusive and mean that additional components may exist in addition to the listed components.

[0069] While the foregoing relates to implementations of this disclosure, other and further implementations of this disclosure may be contemplated without departing from the basic scope of this disclosure, and the scope of this disclosure is defined by the following claims.

Claims

1. A method for processing a substrate, the method comprising: A passivation substrate is positioned in the processing volume of a processing chamber, wherein the passivation substrate has silicon chloride residue formed on the substrate; The silicon chloride residue is evaporated from the passivated substrate; Evaporated silicon chloride is deposited on one or more internal surfaces of the processing volume; The deposited silicon chloride is exposed to an oxidizing environment to convert the deposited silicon chloride into a silicon oxide passivation layer; as well as The production substrate having the silicon oxide passivation layer on one or more internal surfaces in the processing volume of the processing chamber is ashed.

2. The method of claim 1, wherein evaporating the silicon chloride residue from the passivated substrate comprises heating the passivated substrate to a temperature of at least 200°C.

3. The method of claim 1, wherein the oxidizing environment comprises an oxygen-containing plasma, oxygen free radicals, or a combination thereof.

4. The method of claim 3, further comprising: forming the oxygen radicals by exciting a gas mixture containing oxygen-containing gas in a remote plasma chamber.

5. The method of claim 4, wherein the oxygen-containing gas comprises an oxidant selected from oxygen, water vapor, ozone, nitrous oxide, or a combination thereof.

6. The method of claim 5, wherein the gas mixture further comprises an additive selected from nitrogen, argon, helium, or a combination thereof.

7. The method of claim 1, wherein evaporating the silicon chloride residue from the passivated substrate comprises: heating the passivated substrate in a mixture of oxygen and nitrogen gases.

8. The method of claim 7, wherein exposing the deposited silicon chloride to the oxidizing environment further comprises: maintaining the passivated substrate at a temperature of at least 200°C.

9. The method of claim 7, wherein the oxygen to nitrogen flow ratio is about 10:

1.

10. The method of claim 1, wherein at least a portion of the surface of the one or more chambers has a refractory metal deposited on the portion, and the silicon oxide passivation layer is formed over the refractory metal.

11. The method of claim 1, wherein at least one of the one or more chamber surfaces is formed of aluminum, stainless steel, or a combination of the foregoing.

12. The method of claim 1, wherein the one or more chamber surfaces comprise the surface of a gas distribution plate.

13. A method for processing a substrate, the method comprising the following steps: A passivated substrate with an exposed silicon-containing surface is exposed to an etching gas mixture containing chlorine gas to form silicon chloride residue on the exposed silicon-containing surface. The passivated substrate is positioned within the processing volume of the plasma processing chamber; The passivated substrate is heated to evaporate the silicon chloride residue from the exposed silicon-containing surface and to deposit the silicon chloride residue on the surface of one or more internal chambers within the processing volume; The silicon chloride is exposed to an oxidizing environment to convert the silicon chloride residue, thereby forming a silicon oxide passivation layer above one or more internal surfaces in the processing volume of the plasma processing chamber. as well as The production substrate having the silicon oxide passivation layer on the surface of one or more internal chambers in the processing volume from the processing chamber is ashed.

14. The method of claim 13, wherein evaporating the silicon chloride residue from the passivated substrate comprises heating the passivated substrate to a temperature of at least 200°C.

15. The method of claim 13, wherein the oxidizing environment comprises oxygen radicals, and the oxygen radicals are formed by exciting a gas mixture containing oxygen-containing gas in a remote plasma chamber.

16. The method of claim 15, wherein the oxygen-containing gas comprises an oxidant selected from oxygen, water vapor, ozone, nitrous oxide, or a combination thereof.

17. A method for processing a substrate, the method comprising: A passivated substrate with an exposed silicon-containing surface is positioned in the first processing volume of a plasma processing chamber; The passivated substrate is exposed to an etching gas mixture containing chlorine gas to form silicon chloride residue on the exposed silicon-containing surface; The passivated substrate is transferred to the second processing volume of the processing chamber; The passivated substrate is heated to evaporate the silicon chloride residue from the exposed silicon-containing surface onto a gas distribution plate positioned in the second processing volume; The silicon chloride residue on the gas distribution plate is exposed to an oxidizing environment to convert the silicon chloride residue, thereby forming a silicon oxide passivation layer above the gas distribution plate; as well as The production substrate layer having the silicon oxide passivation layer on the gas distribution plate in the second processing volume from the processing chamber is ashed.

18. The method of claim 17, wherein the oxidizing environment comprises an oxygen-containing plasma, an oxygen radical, or a combination thereof.

19. The method of claim 17, wherein at least a portion of the gas distribution plate has a refractory metal deposited on the portion, and the silicon oxide passivation layer is formed over the refractory metal.

20. The method of claim 17, wherein evaporating the silicon chloride residue from the passivated substrate comprises: heating the passivated substrate in a mixture of oxygen and nitrogen gases.

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