Dome-shaped chamber for generating in-situ cleaning plasma

Abstract

The processing chamber includes a first portion including a dome and a second portion. The dome is made of a ceramic material and has an elliptical shape. A pedestal for processing a substrate is disposed in the second portion. A showerhead is disposed at the bottom of the dome between the first and second portions. An injector made of a ceramic material is mounted on the dome and injects a process gas and a cleaning gas into the dome during substrate processing and cleaning of the processing chamber, respectively. A coil is disposed around a portion of the dome. An RF generator supplies RF power to the coil to generate a plasma in the dome during substrate processing and cleaning. A controller controls the temperatures of the pedestal and the showerhead to respective predetermined temperatures within predetermined ranges during substrate processing and cleaning.

Description

[Technical Field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of U.S. Provisional Application No. 63 / 412,152, filed September 30, 2022, the entire disclosure of which is incorporated herein by reference.

[0002] The present disclosure relates generally to substrate processing systems, and more particularly to a domed chamber for generating in-situ cleaning plasma. [Background technology]

[0003] The background discussion provided herein is intended to present the contents of the present disclosure generally. Work by the currently named inventors within the scope of what is described in this Background section, as well as aspects of the description that may not otherwise be considered prior art at the time of filing, are not admitted, expressly or impliedly, as prior art against the present disclosure.

[0004] A substrate processing system typically includes one or more processing chambers. Each processing chamber encloses a pedestal on which a substrate, such as a semiconductor wafer, is placed during processing. A gas delivery system may be used to introduce a process gas mixture, including one or more precursors, into the processing chamber to deposit a film on or etch the substrate. A plasma may be ignited within the processing chamber.

[0005] Some substrate processing systems use the atomic layer deposition (ALD) process to deposit materials onto substrates. ALD is a thin film deposition method that uses sequential chemical processes to deposit a thin film on the surface of a substrate. ALD uses at least two chemicals, called precursors (reactants), that react sequentially and self-limitingly with the surface of one precursor at a time. Through repeated exposure to the distinct precursors, a thin film is gradually deposited on the surface of the substrate. Summary of the Invention

[0006] The substrate processing system includes a processing chamber, a pedestal, a showerhead, an injector, a coil, a radio frequency (RF) generator, and a controller. The processing chamber includes a first portion and a second portion. The first portion includes a dome. The dome is comprised of a ceramic material and has an elliptical shape. The pedestal is configured to process a substrate disposed in the second portion of the processing chamber. The showerhead is disposed at a base of the dome between the first and second portions of the processing chamber. The injector includes a ceramic material mounted on the dome. The injector is configured to inject a process gas and a cleaning gas into the dome during substrate processing and during cleaning of the processing chamber, respectively. The coil is disposed around a portion of the dome. The RF generator is configured to supply RF power to the coil to generate a plasma in the dome during substrate processing and during cleaning of the processing chamber. The controller is configured to control the temperatures of the pedestal and the showerhead to respective predetermined temperatures within predetermined ranges during substrate processing and during cleaning of the processing chamber.

[0007] In an additional feature, the predetermined range is 0 to 1% of each predetermined temperature.

[0008] In an additional feature, the controller is configured to maintain the temperatures of the pedestal and showerhead unchanged at their respective predetermined temperatures during substrate processing and during cleaning of the processing chamber.

[0009] In an additional feature, the ceramic material is alumina.

[0010] In an additional feature, the interior wall of the dome is coated with a second material that is resistant to heat and corrosion.

[0011] In an additional feature, the second material is yttria.

[0012] In additional features, the substrate processing system further comprises an enclosure disposed around the dome and the coil and attached to the periphery of the showerhead, the enclosure comprising a plurality of fans symmetrically arranged in an azimuth direction along a sidewall of the enclosure.

[0013] In certain additional features, the substrate processing system further comprises a gas delivery system configured to supply a cleaning gas through the injector at a rate that inhibits particles emitted from the pedestal from contaminating the showerhead during cleaning of the processing chamber.

[0014] In certain additional features, the substrate processing system further comprises a gas delivery system configured to supply an inert gas directly to the showerhead to inhibit particles released from the pedestal from contaminating the showerhead during cleaning of the processing chamber.

[0015] In certain additional features, the substrate processing system further comprises a gas delivery system configured to supply an inert gas directly to the showerhead to prevent cleaning gas from stagnating in the showerhead after cleaning the processing chamber.

[0016] In additional features, the substrate processing system further comprises a gas delivery system. The showerhead comprises a first plenum and a second plenum. The first plenum is configured to filter ions from the plasma and pass radicals to a second portion of the processing chamber. The second plenum is configured to (i) receive precursors directly from the gas delivery system and deliver the precursors to the second portion of the processing chamber during substrate processing, and (ii) receive inert gas directly from the gas delivery system during cleaning of the processing chamber.

[0017] In one additional feature, the coil includes multiple turns, the number of turns and the location of the turns around the dome distributing the ion and heat load from the plasma throughout the dome.

[0018] In additional features, the pedestal comprises a heater. The substrate processing system further comprises a fluid delivery system configured to supply a coolant to the pedestal and the showerhead. A controller is configured to control the flow of the heater and the coolant to maintain the temperatures of the showerhead and the pedestal within predetermined ranges of their respective predetermined temperatures during substrate processing and during cleaning of the processing chamber.

[0019] In additional features, the pedestal comprises a heater. The substrate processing system further comprises a fluid delivery system configured to supply coolant to the pedestal and the showerhead. The controller is configured to control the flow of the heater and cooling water to maintain the temperatures of the pedestal and the showerhead unchanged at their respective predetermined temperatures during substrate processing and cleaning of the processing chamber.

[0020] In yet another feature, a method for cleaning a processing chamber having a pedestal and a showerhead configured to process a substrate includes controlling the temperatures of the pedestal and the showerhead within predetermined ranges of respective predetermined temperatures used during substrate processing during cleaning of the processing chamber. The method includes supplying a cleaning gas into an elliptical dome of the processing chamber, the elliptical dome comprising a ceramic material, through an injector mounted on the elliptical dome and comprising a ceramic material. The method includes generating a plasma within the elliptical dome by supplying radio frequency (RF) power to a coil disposed around the elliptical dome. The method includes controlling a flow of the cleaning gas through the injector to suppress contamination of the showerhead by particles emitted from the pedestal.

[0021] In an additional feature, the predetermined range is 0 to 1% of each predetermined temperature.

[0022] In certain additional features, the method further includes maintaining the temperatures of the pedestal and showerhead at their respective predetermined temperatures without change during processing of the substrate and during cleaning of the processing chamber.

[0023] In an additional feature, the method further includes spray coating the interior wall of the elliptical dome with a second material that is resistant to heat and corrosion.

[0024] In an additional feature, the ceramic material is alumina and the second material is yttria.

[0025] In an additional feature, the method includes enclosing the elliptical dome and the coil in an enclosure mounted around the showerhead, and cooling the elliptical dome using a plurality of fans symmetrically positioned azimuthally along a sidewall of the enclosure.

[0026] In an additional feature, the method further includes further inhibiting contamination of the showerhead by particles by supplying an inert gas directly to the showerhead.

[0027] In an additional feature, the method further includes preventing the cleaning gas from stagnating in the showerhead by flowing an inert gas directly into the showerhead.

[0028] In an additional feature, the method further includes distributing ion and heat load from the plasma throughout the elliptical dome by disposing turns of a coil around the periphery of the elliptical dome.

[0029] In additional features, the method further includes, after cleaning the processing chamber, stopping the supply of the cleaning gas and the RF power; controlling the temperatures of the pedestal and the showerhead within predetermined ranges of their respective predetermined temperatures; and processing a second substrate in the processing chamber by supplying a process gas through the injector into the elliptical dome.

[0030] In certain additional features, the method further includes delivering the precursor directly to the showerhead.

[0031] In an additional feature, the method further includes igniting a second plasma within the elliptical dome by supplying RF power to the coil, and filtering ions from the second plasma and passing radicals to the second substrate.

[0032] In certain additional features, the method further includes maintaining temperatures of the showerhead and the pedestal within predetermined ranges of their respective predetermined temperatures by supplying coolant through the pedestal and the showerhead during processing of a second substrate in the processing chamber.

[0033] In certain additional features, the method further includes maintaining the temperatures of the pedestal and the showerhead unchanged at their respective predetermined temperatures by supplying coolant through the pedestal and the showerhead during processing of a second substrate in the processing chamber.

[0034] Further scope of applicability of the present disclosure will become apparent from the detailed description, claims, and drawings. The detailed description and specific examples are for purposes of illustration only and are not intended to limit the scope of the present disclosure. [Brief explanation of the drawings]

[0035] The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:

[0036] [Figure 1] FIG. 1 illustrates an example substrate processing system with a dome-shaped processing chamber utilized to generate in-situ cleaning plasma during substrate processing and chamber cleaning in accordance with the present disclosure.

[0037] [Figure 2] FIG. 2 is a schematic diagram illustrating an example of an enclosure that includes a cooling fan and surrounds the dome of the processing chamber of the substrate processing system of FIG.

[0038] [Figure 3]FIG. 3 illustrates in greater detail an example portion of a gas delivery system used in the substrate processing system of FIG.

[0039] [Figure 4] FIG. 4 shows a flow chart of a method for substrate processing and cleaning the processing chamber of FIG. 1 using an in-situ cleaning plasma while maintaining the pedestal and showerhead temperatures unchanged during substrate processing and cleaning.

[0040] In the drawings, reference numbers may be reused to identify similar and / or identical elements. DETAILED DESCRIPTION OF THE INVENTION

[0041] Some substrate processing systems (also called tools) include up to four processing chambers that are used to deposit materials onto substrates using deposition processes. The processing chambers are periodically cleaned using a cleaning process, during which substrate production is interrupted. That is, the cleaning process is performed separately and distinctly from the deposition process. For example, the cleaning process is typically performed after numerous cycles of the deposition process and during periodic preventative maintenance procedures to clean the processing chamber and its components.

[0042] In a typical cleaning process used to clean processing chambers, a remote plasma source (RPS) located outside the processing chambers is used to generate the cleaning plasma. For example, the RPS is centrally located between the processing chambers, and the cleaning plasma from the RPS is supplied to each processing chamber to clean the processing chamber. However, using an externally generated cleaning plasma to clean multiple processing chambers presents various problems.

[0043] For example, various components of the processing chamber, such as the showerhead and pedestal, need to be set to temperatures for the cleaning process that are different from the deposition process used to process the substrate in the processing chamber. For example, the temperatures of the showerhead and pedestal are typically maintained at 50 degrees Celsius and 550 degrees Celsius, respectively. These temperatures may vary depending on the process (e.g., recipe) used to process the substrate in the processing chamber. The temperatures of the showerhead and pedestal are typically maintained at 150 degrees Celsius and 400 degrees Celsius, respectively, during the cleaning process.

[0044] Typically, before performing the cleaning process, the pedestal temperature is lowered below the temperature used during substrate processing (e.g., 550-400 degrees Celsius) because higher temperatures (e.g., above 450 degrees Celsius) can cause surface particle shedding on the pedestal, which can contaminate the showerhead. Therefore, to minimize particle shedding from the surface of the pedestal that could contaminate the showerhead, the pedestal temperature is typically lowered below the temperature used during substrate processing (e.g., 550-400 degrees Celsius) before performing the cleaning process.

[0045] After the cleaning process, the showerhead temperature is reduced (e.g., from 150 to 50 degrees Celsius) and the pedestal temperature is increased (e.g., from 400 to 550 degrees Celsius). Due to the different temperature settings used during substrate processing and the cleaning process, additional time is required to transition the temperature of the components between the temperatures required for the deposition process and the cleaning process. The additional time required for such temperature transitions reduces the production time of the processing chamber.

[0046] Furthermore, the contamination problem is exacerbated by the fact that the cleaning plasma is delivered to a location in the processing chamber between the showerhead and the pedestal: due to the location of the cleaning plasma delivery and the typical conical shape of the plasma chamber, particles generated from the pedestal surface are carried towards the showerhead, contaminating it.

[0047] Additionally, the movement of the remote cleaning plasma within the processing chamber is such that it does not effectively clean the showerhead (i.e., the etch rate in the showerhead is lower than the etch rate in the pedestal), even though the cleaning process takes a long time to clean the showerhead. Therefore, the cleaning process using the remote cleaning plasma exacerbates particle contamination of the showerhead that occurs during the cleaning process. Therefore, the showerhead must undergo a requalification process before proceeding to the cleaning process, after which the deposition process can resume in the processing chamber. The requalification process, which is performed in all four processing chambers of the tool, further shortens the production time of the processing chambers.

[0048] The present disclosure provides an in-situ plasma-based cleaning process that solves the above-mentioned problems. The disclosed in-situ plasma-based cleaning process is also performed separately and distinctly from processes, such as ALD, that are performed to process substrates in the processing chamber. For example, the cleaning process is typically performed after numerous cycles of processing substrates in the processing chamber and during preventative maintenance procedures that are periodically performed to clean the processing chamber and its components.

[0049] Specifically, in an in-situ plasma-based cleaning process, instead of supplying a remotely generated cleaning plasma to the processing chambers, the cleaning plasma is generated in-situ within each processing chamber. Furthermore, the temperature of components, such as the showerhead and pedestal, is not changed between the cleaning process and the deposition process. During the cleaning process, the components are maintained at the same temperature as during substrate processing. At most, the component temperature may vary within a predetermined range (e.g., a narrow range of 0-1%) between substrate processing and the cleaning process. For practical purposes, the component temperature is considered to be uniform (i.e., substantially equal) during substrate processing and the cleaning process as long as the temperature is maintained within the predetermined range. Throughout this disclosure, uniforming the component temperature during substrate processing and the cleaning process should be understood to mean controlling or maintaining the component temperature at a respective predetermined temperature within a predetermined range, such as 0-1%. The predetermined range is described in more detail below, following the description of FIG. 4 . The cleaning process using in-situ plasma generated in each processing chamber provides the following improvements:

[0050] Cleaning processes using in-situ plasma generated in each processing chamber provide the following improvements: By unifying the temperature of parts for the cleaning and deposition processes, the time required to transition between the different temperature settings typically used in these processes is eliminated. Eliminating the time required for temperature transitions increases the production time of the processing chamber.

[0051] Furthermore, cleaning plasma is generated in each processing chamber using the same equipment used to generate plasma during the deposition process. Specifically, during the deposition process, process gas is supplied through an injector installed at the top of the processing chamber, and plasma is ignited in the processing chamber. During the cleaning process, cleaning gas is supplied through the same injector installed at the top of the processing chamber, and cleaning plasma is ignited in the processing chamber. The cleaning plasma first passes through the showerhead, cleaning the showerhead first, before reaching and cleaning the pedestal. That is, the etch rate at the showerhead is higher than the etch rate at the pedestal. In this way, the in-situ plasma-based cleaning process not only eliminates the need for a remote plasma source, but also provides better showerhead cleaning than a remote cleaning plasma. Because the in-situ cleaning plasma provides better showerhead cleaning than a remote cleaning plasma, the in-situ cleaning plasma-based cleaning process also has a shorter duration than a remote plasma-based cleaning process.

[0052] Furthermore, to ensure uniform component temperatures for the cleaning and deposition processes, the pedestal must be maintained at the same temperature (e.g., 550°C) during the cleaning process as during substrate processing. High pedestal temperatures can generate particles from the pedestal surface that can contaminate the showerhead. In-situ plasma-based cleaning processes mitigate (suppress) showerhead particle contamination by controlling (e.g., increasing) the flow of cleaning gas through the injectors during the cleaning process.

[0053] Furthermore, cleaning gases tend to stagnate within the showerhead, potentially contaminating and damaging it. Cleaning gas stagnation within the showerhead can be prevented (i.e., purging traces of cleaning gas) by flowing an inert gas (called a trickle) directly through the showerhead. Therefore, there is no need to requalify the showerhead after the cleaning process; the deposition process can resume production immediately after the cleaning process. Furthermore, because the showerhead and pedestal temperatures are not changed (i.e., uniform) between the deposition and cleaning processes, the processing chamber is ready for production immediately after the cleaning process. The duration of the in-situ plasma-based cleaning process is further shortened by eliminating the temperature transition time and mitigating particle contamination of the showerhead.

[0054] In this manner, the in-situ plasma-based cleaning process of the present disclosure eliminates a remote plasma source, cleans the showerhead better than a remote plasma-based cleaning process, eliminates particle contamination of the showerhead, and increases the production time of the processing chamber compared to when a remote cleaning process is used.

[0055] In in-situ plasma-based cleaning processes, the geometry and material of the process chamber dome where the plasma is ignited differs from conventional process chambers that use remote plasma for cleaning processes. The different geometry (discussed in detail below) optimizes the plasma movement during deposition and cleaning processes. The different dome material, along with a coating applied to the dome's inner surface, reduces etching and corrosion of the dome's inner surface due to the harsh chemical, thermal, and electrical environments used during deposition and cleaning processes.

[0056] Additionally, the injectors of the processing chamber also comprise a different material than those used in injectors of conventional processing chambers that use remote plasma-based cleaning processes. The different material reduces etching and corrosion of the injectors due to the harsh environments used during deposition and cleaning processes. Additionally, the present disclosure also provides an enclosure that provides improved cooling of the dome and the RF coil disposed around the dome for plasma generation. These and other features of the present disclosure are described in detail below.

[0057] This disclosure is organized as follows: Section 1 illustrates and describes an example substrate processing system 100 with a dome-shaped processing chamber, with reference to FIG. 1. Section 2 details the design of the enclosure with the dome, coil, and fan, with reference to FIGS. 1 and 2. Section 3 describes the controlled delivery of cleaning and inert gases to mitigate showerhead contamination, with reference to FIGS. 1 and 3. Section 4 describes methods for processing substrates and cleaning plasma chambers according to the present disclosure, with reference to FIG. 4. Section 1: Substrate Processing Systems

[0058] 1 illustrates a substrate processing system 100 (also referred to as a tool) according to the present disclosure. The substrate processing system 100 includes a processing chamber 103. The substrate processing system 100 may include multiple (e.g., four) processing chambers (also referred to as stations or process modules) similar to the processing chamber 103 and including components similar to those of the processing chamber 103 described below. Some of the components of the substrate processing system 100 described below may be common to multiple processing chambers of the substrate processing system 100. Examples of components of the substrate processing system 100 that are common to multiple processing chambers include a gas delivery system (elements 10, 170), an RF generation system (element 136), a fluid delivery system (element 180), a temperature controller (182), and a system controller (element 190).

[0059] The processing chamber 103 includes a dome 102, a showerhead 104, and a pedestal 112. The dome 102 will be described in more detail below after the plasma generation discussion. Briefly, the dome 102 is elliptical. Specifically, the shape of the dome 102 is a portion of an ellipse, and has an elliptical profile. The shape of the dome resembles an ellipse with the bottom removed along a horizontal plane. The dome 102 comprises a ceramic material (e.g., alumina). The dome 102 is positioned above and attached to the showerhead 104. The pedestal 112 is positioned below the showerhead 104. The showerhead 104 separates the dome 102 from the pedestal 112.

[0060] The space defined by the inner wall of the dome 102 and the top surface of the showerhead 104 may be referred to as the upper portion (or first portion) of the processing chamber 103. The space defined by the substrate-facing surface below the showerhead 104 and the sidewall 108 and bottom wall 110 of the processing chamber 103 may be referred to as the lower portion (or second portion) of the processing chamber 103. The pedestal 112 is disposed in the lower portion of the processing chamber 103 below the showerhead 104. The showerhead 104 separates the upper and lower portions of the processing chamber 103.

[0061] The showerhead 104 is a dual plenum showerhead. The showerhead 104 comprises a metal (e.g., aluminum) or alloy. The showerhead 104 includes a planar base portion 105 and a cylindrical portion 107 extending vertically downward from the base portion 105. The base portion 105 is horizontal and parallel to the upper surface 116 of the pedestal 112 and the bottom wall 110 of the processing chamber 103. The base portion 105 extends radially outward from the upper portion of the cylindrical portion 107. The base portion 105 extends radially outward from the outer diameter (OD) of the cylindrical portion 107 to form a flange 118. The flange 118 is fastened to a top plate (not shown) of the processing chamber 103. An O-ring (not shown) may be provided between the flange 118 and the top plate to form a seal between the showerhead 104 and the top plate. The cylindrical portion 107 has an outer wall 109-1 and an inner wall 109-2. The inner wall 109-2 of the cylindrical portion 107 defines a bore 106 of the showerhead 104. The diameter of the bore 106 is equal to the diameter of the inner wall 109-2 of the cylindrical portion 107 of the showerhead 104 (i.e., the inner diameter or ID of the cylindrical portion 107).

[0062] The sidewall 108 of the processing chamber 103 is attached to the bottom of the cylindrical portion 107 of the showerhead 104. The sidewall 108 is perpendicular to the base portion 105 of the showerhead 104 and extends vertically downward from the bottom of the outer wall 109-1 of the cylindrical portion 107 of the showerhead 104. The bottom wall 110 of the processing chamber 103 is parallel to the base portion 105 of the showerhead 104, perpendicular to the sidewall 108 of the processing chamber 103, and attached to the sidewall 108 of the processing chamber 103.

[0063] During processing, the substrate 114 is placed on the upper surface 116 of the pedestal 112 during processing. The upper surface 116 of the pedestal 112 is flat and parallel to the base portion 105 of the showerhead 104 and the bottom wall 110 of the processing chamber 103. Therefore, when the substrate 114 is placed on the upper surface 116 of the pedestal 112, the substrate 114 is parallel to the upper surface 116 of the pedestal 112, the base portion 105 of the showerhead 104, and the bottom wall 110 of the processing chamber 103. The ID of the cylindrical portion 107 of the showerhead 104 (i.e., the diameter of the inner wall 109-2 of the showerhead 104) is larger than the OD of the upper surface 116 of the pedestal 112. The ID of the cylindrical portion 107 of the showerhead 104 (i.e., the diameter of the inner wall 109-2 of the showerhead 104) is also larger than the OD of the substrate 114.

[0064] An actuator 120 driven by a motor 122 can move the pedestal 112 vertically up and down relative to the showerhead 104 within the cylindrical portion 107 of the showerhead 104. The dome 102 and showerhead 104 are fixed relative to the pedestal 112. The gap between the bottom of the base portion 105 of the showerhead 104 and the top surface 116 of the pedestal 112 may be adjusted by vertically moving the pedestal 112 within the cylindrical portion 107 of the showerhead 104. For example, during substrate processing, the gap between the bottom of the base portion 105 of the showerhead 104 and the top surface 116 of the pedestal 112 may be approximately 0.2 inches (approximately 5.08 mm), 0.15 inches (approximately 3.81 mm), or 0.11 inches (approximately 2.79 mm). When a cleaning process (described in detail below with reference to FIG. 4 ) is performed to clean the processing chamber 103, the pedestal 112 may be further lowered below the showerhead 104. During the cleaning process, the gap between the bottom of the base portion 105 of the showerhead 104 and the top surface 116 of the pedestal 112 may be much larger than the gap during substrate processing.

[0065] The bottom end of the dome 102 is attached to the periphery of the top end of the showerhead 104 using a cylindrical part 124. Specifically, the bottom end of the dome 102 is attached to the top surface 162 of the base portion 105 of the showerhead 104 using the cylindrical part 124. For example, the cylindrical part 124 comprises a "T" shaped ring and includes a horizontal part 126 and a vertical part 128. The horizontal part 126 has a first end that defines the outer edge of the cylindrical part 124 and a second end that defines the inner edge of the cylindrical part 124. The first end of the horizontal part 126 (i.e., the outer edge of the cylindrical part 124) is attached to the periphery of the top surface 162 of the showerhead 104 using fasteners (not shown). The outer wall of the dome 102 is attached to the vertical part 128 along the inner diameter of the vertical part 128. The inner wall of the dome 102 extends downward beyond the second end of the horizontal part 126. The inner wall of the dome 102 is attached to the top surface 162 of the base portion 105 of the showerhead 104 near the second end of the horizontal portion 126 (ie, near the inner edge of the cylindrical part 124).

[0066] The dome 102 generates a plasma (specifically, an inductively coupled plasma, or ICP) in the upper portion of the processing chamber 103 as follows: The dome 102 receives one or more gases from a gas distribution system 130 via a gas injector 132 mounted on the top of the dome 102. For example, as described in more detail below, the gas injector 132 may inject one or more process gases received from the gas distribution system 130 into the dome 102 during substrate processing. The gas injector 132 may inject one or more cleaning gases received from the gas distribution system 130 into the dome 102 during a cleaning process. The gas injector 132 comprises a ceramic material, such as alumina.

[0067] The gas delivery system 130 includes one or more gas sources 150-1, 150-2, ..., 150-N (collectively, gas sources 150), where N is an integer greater than 1. The gas sources 150 are connected to a manifold 156 by valves 152-1, 152-2, ..., 152-N (collectively, valves 152) and mass flow controllers 154-1, 154-2, ..., 154-N (collectively, mass flow controllers 154). The manifold 156 is connected to a gas injector 132. One or more of the gas sources 150 supply one or more process gases to the dome 102 via the manifold 156 and the gas injector 132 during substrate processing. One or more of the gas sources 150 supply one or more cleaning gases to the dome 102 via the manifold 156 and the gas injector 132 during a cleaning process, as described below.

[0068] A coil 134 is disposed around the dome 102. The coil 134 is described in more detail below. Briefly, the coil 134 may include multiple turns (e.g., three or more). A first end of the coil 134 is grounded. A second end of the coil 134 is connected to an RF generating system 136.

[0069] An RF generation system 136 generates and outputs RF power to the coil 134. By way of example only, the RF generation system 136 includes an RF generator 138 that generates RF power. The RF power is delivered to the coil 134 by a matching network 140. The RF power supplied to the coil 134 ignites a gas or gases injected into the dome 102 by the gas injector 132, generating a plasma 142 within the dome 102 (i.e., in the upper portion of the processing chamber 103). Thus, the processing chamber 103 does not use a remote plasma, which is typically generated by a remote plasma source located outside the processing chamber 103. Instead, the plasma 142 is generated in situ (i.e., within the dome 102 of the processing chamber 103) during both substrate processing and cleaning processes.

[0070] The base portion 105 of the showerhead 104 includes a first set of holes (also referred to as radical holes, as described above) 160-1, 160-2, ..., 160-N (collectively referred to as radical holes 160), where N is an integer greater than 1. The radical holes 160 extend vertically from a top surface 162 of the base portion 105 of the showerhead 104 to a bottom surface 164 (also referred to as a faceplate 164) of the base portion 105 of the showerhead 104 that faces the substrate. The radical holes 160 may be referred to as a first plenum of the showerhead 104.

[0071] The showerhead 104 filters ions from the plasma 142 and passes radicals from the plasma 142 through radical holes 160 into a second portion of the processing chamber 103. The radicals react with precursors in the gap between the showerhead 104 and the pedestal 112 to deposit a thin film on the substrate 114 using a process such as ALD. The open area provided by the radical holes 160 for the radicals to pass through the showerhead 104, as well as the density and pattern of the radical holes 160 and precursor holes 172, results in films deposited using the showerhead 104 having near-zero radial and azimuthal non-uniformity.

[0072] Additionally, the base portion 105 of the showerhead 104 includes a plenum 166 that is separate (discontinuous) from the radical holes 160. The plenum 166 is not in fluid communication with the radical holes 160. The plenum 166 may be referred to as a second plenum of the showerhead 104. The plenum 166 receives one or more precursor gases from a second gas delivery system 170 during substrate processing. The plenum 166 receives an inert gas from the second gas delivery system 170 during a cleaning process. The second gas delivery system 170 will be described in more detail below with reference to FIG. 3 .

[0073] The base portion 105 of the showerhead 104 further comprises a second set of holes (also referred to as precursor holes) 172-1, 172-2, ..., 172-N (collectively, precursor holes 172), where N is an integer greater than 1. The precursor holes 172 extend vertically from the plenum 166 through the base portion 105 and through the faceplate 164 of the showerhead 104. One or more precursor gases are supplied through the precursor holes 172 to a lower portion of the processing chamber during substrate processing. The precursor holes 172 and plenum 166 are not in fluid communication with the radical holes 160.

[0074] The radical holes 160 and the precursor holes 172 are cylindrical. The diameter and length of the radical holes 160 are larger than those of the precursor holes 172. The radical holes 160 are tapered at their upper ends (i.e., the side facing the dome 102). The total cross-sectional area of ​​the radical holes 160 is optimized to filter ions from the plasma 142 and allow only radicals to pass from the plasma 142 through the showerhead 104 and into the lower portion of the processing chamber 103, which comprises the pedestal 112. The adjustable gap between the faceplate 164 of the showerhead 104 and the upper surface 116 of the pedestal 112 allows for precise control of the microvolume in the ALD process. Furthermore, the narrow gap between the faceplate 164 of the showerhead 104 and the upper surface 116 of the pedestal 112 prevents radical depletion in the microvolume within the gap.

[0075] The outer wall 109-1 of the cylindrical portion 107 of the showerhead 104 does not directly contact the top plate of the processing chamber 103. Because of this feature, and because the cylindrical portion 107 of the showerhead 104 extends vertically below the upper surface 116 of the pedestal 112 on which the substrate 114 is disposed, the cylindrical portion 107 of the showerhead 104 provides a symmetrical thermal boundary condition (i.e., a region of constant temperature) around the edge of the upper surface 116 of the pedestal 112. Thus, the pedestal 112 can be moved vertically within the cylindrical portion 107 (i.e., through its height) to adjust the gap between the showerhead 104 and the pedestal 112 without significantly changing the thermal boundary condition surrounding the edge of the upper surface 116 of the pedestal 112, which is advantageous during substrate processing.

[0076] Additionally, the cylindrical portion 107 of the showerhead 104 also provides a constant constriction in the gas flow around the edge of the top surface 116 of the pedestal 112 as the pedestal 112 is moved up and down within the cylindrical portion 107. This simplifies the process of controlling the minute volume of gas in the gap between the showerhead 104 and the pedestal 112 because the cylindrical portion 107 surrounds and is in close proximity to the edge of the top surface 116 of the pedestal 112, keeping the gas flow conditions around the edge of the top surface 116 of the pedestal 112 constant. Thus, the pedestal 112 can be moved vertically within the cylindrical portion 107 (i.e., through the height of the cylindrical portion 107) to adjust the gap between the showerhead 104 and the pedestal 112 without significantly changing the gas flow conditions around the edge of the top surface 116 of the pedestal 112.

[0077] The base portion 105 of the showerhead 104 further comprises a plurality of grooves 168-1, 168-2, ..., 168-N (collectively grooves 168), where N is an integer greater than 1. The grooves 168 form cooling channels (described with reference to FIG. 3) through which a coolant flows. A fluid delivery system 180 supplies the coolant to the grooves 168 through inlets in the base portion 105 of the showerhead 104.

[0078] One or more temperature sensors (not shown) may be provided on the base portion 105 of the showerhead 104. The temperature sensors may be connected to a temperature controller 182. The temperature controller 182 may control the supply of coolant from the fluid delivery system 180 to the grooves 168 to control the temperature of the showerhead 104, which receives heat from the pedestal 112 and the plasma 142. The coolant flows through the grooves 168 and controls the temperature of the showerhead 104. The temperature of the showerhead 104 is lower than the temperature of the pedestal 112 during substrate processing and cleaning processes. The temperature controller 182 maintains the temperature of the showerhead 104 at a first predetermined temperature (e.g., 50 degrees Celsius) lower than the temperature of the pedestal 112 (e.g., 550 degrees Celsius) during substrate processing and cleaning processes.

[0079] Further, the pedestal 112 may include one or more heaters 184, a cooling system that receives coolant from the fluid delivery system 180, and one or more temperature sensors. The temperature controller 182 may be connected to the temperature sensor in the pedestal 112. The temperature controller 182 may control the supply of power to the heater 184. The temperature controller 182 may control the supply of coolant from the fluid delivery system 180 to the cooling system in the pedestal 112 to control the temperature of the pedestal 112. The temperature of the pedestal 112 is higher than the temperature of the showerhead 104 during substrate processing and cleaning processes. The temperature controller 182 maintains the temperature of the pedestal 112 at a second predetermined temperature (e.g., 550 degrees Celsius) higher than the temperature of the showerhead 104 (e.g., 50 degrees Celsius) during substrate processing and cleaning processes.

[0080] The processing chamber 103 further includes a housing 125. The housing 125 is cylindrical. The housing 125 is mounted on top of the showerhead 104. Specifically, the housing 125 is mounted on a vertical portion 128 of the cylindrical part 124. The housing 125 will be described in more detail below with reference to FIG. 2. Briefly, the housing 125 encloses the dome 102 and the coil 134. The housing 125 includes a plurality of fans (schematically shown in FIG. 2). The fans are arranged in an azimuthally symmetric configuration along the sidewalls of the housing 125, as will be described in more detail below with reference to FIG. 2, to provide uniform cooling to the dome 102 and the coil 134.

[0081] A valve 186 and a pump 188 control the pressure within the processing chamber 103. The pump 188 also evacuates reactants from the processing chamber 103 during substrate processing and cleaning processes. A system controller 190 controls the components of the substrate processing system 100 described above and below. Section 2: Dome, Coil, Injector, and Housing

[0082] The dome 102, coil 134, gas injector (hereinafter "injector") 132, and housing 125 will now be described in detail with reference to Figures 1 and 2. As noted above, the dome 102 is elliptical and comprises a ceramic material, such as alumina. The elliptical shape of the dome 102 is not merely a design choice. Rather, the elliptical shape of the dome 102 was selected after extensive experimentation because it significantly reduced plasma-induced thermal stresses on the dome 102 compared to other shapes.

[0083] Additionally, the number of turns in the coil 134 and the positioning of the coil 134 around the dome 102 are not simply design choices. Rather, the number of turns in the coil 134 and the positioning of the coil 134 around the dome 102 are specifically designed to improve the thermal load on the dome 102 and increase the useful life of the dome 102. Furthermore, the elliptical shape of the dome 102, as well as the number of turns and positioning of the coil 134 around the dome 102, are specifically designed to increase the volume of the plasma 142 and increase the surface area of ​​the dome 102 against which ions impinge (thereby reducing damage to the interior walls of the dome 102 compared to other shapes), thereby reducing the thermal stress load on the dome 102.

[0084] Additionally, as noted above, the dome 102 and injector 132 comprise a ceramic material, such as alumina, but this is not a design choice. Other materials, such as quartz, would be etched away by the plasma 142 generated during substrate processing and cleaning processes. Other materials, such as quartz, would be etched away by corrosive cleaning gases (e.g., fluorine) and other harsh process chemicals used during substrate processing and cleaning processes, as well as by ion bombardment from the plasma. Therefore, after extensive experimentation, a ceramic material, such as alumina, which has a low dielectric constant and will not be etched away in harsh environments, was selected to construct the dome 102 and injector 132 instead of quartz. A ceramic material, such as alumina, allows the dome 102 and injector 132 to be used to generate a plasma 142 within the dome 102 by process gases during substrate processing and by cleaning gases during cleaning processes.

[0085] Additionally, the inner wall of dome 102 is coated (e.g., spray coated) with a material (e.g., yttria) that is highly resistant to plasma-induced heat and corrosion. The coating on the inner wall of dome 102 is indicated by 111. Coating 111 (e.g., yttria) not only adheres well to alumina but also increases the alumina's resistance to plasma-induced heat and corrosion. Thus, coating 111 further protects the inner wall of dome 102 from damage due to ion bombardment from plasma 142 and from plasma-induced thermal and chemical stresses.

[0086] Thus, dome 102 and injector 132 comprising a ceramic material such as alumina serve the dual purpose of enabling substrate processing and chamber cleaning using in-situ plasma 142 generated using a wide range of aggressive chemicals, while also lasting longer than if these components were made from other materials such as quartz.

[0087] FIG. 2 shows a schematic of the housing 125. The housing 125 includes fans, generally designated 127-1, 127-2, ..., 127-8 (collectively referred to as fans 127). While eight fans 127 are shown by way of example only, any number of fans may be used. For symmetry, there may be an even number of fans 127. As noted above, the fans 127 are arranged in an azimuthally symmetric configuration along the sidewall of the housing 125. Specifically, the housing 125 is cylindrical. The fans 127 are positioned equidistant from one another on a circle along the sidewall of the housing 125. Furthermore, the fans 127 are positioned at the same distance d from the top and bottom of the housing 125.

[0088] Fans 127 provide cooling to dome 102 and coil 134. The cooling provided by fans symmetrically positioned in enclosure 125 is also not simply a design choice. Rather, the azimuthally symmetrical placement, selected through extensive experimentation, allows fans 127 to distribute heat evenly throughout dome 102, improving thermal uniformity within dome 102. Specifically, the azimuthally symmetrical placement of fans along the sidewalls of enclosure 125 is designed to effectively dissipate heat during low-power substrate processing and high-power cleaning processes. Therefore, in addition to the elliptical shape of dome 102 and the design of coil 134, which reduce thermal stress on dome 102 as described above, the azimuthally symmetrical placement of fans within enclosure 125 further reduces thermal stress on dome 102.

[0089] In some embodiments, although not shown, the fans 127 may be staggered. For example, the staggered fans 127 may be placed on two different circles (e.g., a first circle and a second circle) along the sidewall of the housing 125. The first circle may be the same distance (e.g., a first distance) from the top of the housing 125 as the second circle is from the bottom of the housing 125. The distance between the two circles (e.g., the second distance) may be the same as or different from the first distance. In each circle, the fans 127 may be equidistant from each other, but the positions of the fans 127 in the first circle may be staggered or offset relative to the positions of the fans 127 in the second circle. In other embodiments, the positions of the fans 127 in both circles may be vertically aligned with each other. In some examples, the fans 127 may be arranged in two or more circles using any of the arrangements described above. Any combination of the arrangements described above may be used. Furthermore, in some embodiments, all of the fans 127 in any of the above arrangements and combinations thereof may have the same cooling capacity, while in other embodiments, at least some of the fans 127 may have a different cooling capacity or multiple cooling capacities.

[0090] The design of the enclosure 125, including the dome 102, coil 134, injector 132, and fan 127, provides many of the advantages discussed above. Additionally, as discussed above, conventional substrate processing systems not only use a remote plasma source, which is eliminated in the substrate processing system 100 by using the in-situ plasma 142, but also require changing the temperature of the showerhead and pedestal during the cleaning process relative to the temperature used during substrate processing. Changing the temperature before and after the cleaning process wastes time and reduces the yield of processed substrates.

[0091] In contrast, by using an in-situ plasma 142 generated within the dome 102 (using different gases and chemicals) during both substrate processing and the cleaning process, the temperature of the showerhead 104 and pedestal 112 does not need to be changed between substrate processing and the cleaning process. Instead, the temperature of the showerhead 104 and pedestal 112 is maintained (i.e., the temperature is uniform or not changed) during both substrate processing and the cleaning process. Uniformity of the temperature of the showerhead 104 and pedestal 112 during both substrate processing and the cleaning process allows for a seamless transition between substrate processing and the cleaning process. Uniformity of the temperature eliminates the time and production loss caused by waiting times required by conventional substrate processing systems, which cannot begin the cleaning process until a first temperature required for the cleaning process is reached, and then cannot resume substrate processing until a second temperature required for the cleaning process is reached. Section 3: Mitigating Showerhead Contamination

[0092] Furthermore, as mentioned above, particles ejected (e.g., etched) from the surface (e.g., top surface 116) of the pedestal 112 during the cleaning process tend to contaminate the showerhead 104. Conventional cleaning processes, which introduce a remotely generated cleaning plasma into the processing chamber between the showerhead and the pedestal, require long cleaning times for the reasons discussed above. Nevertheless, some particles may still remain in the showerhead. Therefore, the showerhead must be requalified for use before substrates can be processed.

[0093] In contrast, in the substrate processing system 100, no remote plasma is used. Instead, cleaning gas is supplied into the dome 102 through the injector 132, and a plasma 142 is generated in situ within the dome 102. As such, the plasma 142 first cleans the showerhead 104 and then cleans the pedestal 112. Because the plasma 142 encounters the showerhead 104 first, the plasma 142 cleans the showerhead 104 more effectively than when a remote plasma is introduced between the showerhead and the pedestal in a conventional cleaning process.

[0094] Furthermore, to mitigate particles ejected (e.g., etched) from the surface (e.g., upper surface 116) of the pedestal 112 from contaminating the showerhead 104, the controller 190 controls the flow of cleaning gas through the injector 132. For example, the cleaning gas can be supplied at a high flow rate and / or high pressure. The controlled flow of cleaning gas through the injector 132 pushes particles ejected (e.g., etched) from the surface of the pedestal 112 downward toward the showerhead 104. In this manner, the controlled flow of cleaning gas through the injector 132 mitigates (prevents) particles ejected (e.g., etched) from the surface of the pedestal 112 from contaminating the showerhead 104.

[0095] Furthermore, because the injector 132 comprises a ceramic material such as alumina, the injector 132 can handle (i.e., is not damaged by) the additional corrosive stress imposed on the injector 132 by a high flow rate of cleaning gas. To uniformly maintain the temperatures of the showerhead 104 and the pedestal 112 during substrate processing and the cleaning process, the pedestal 112 must be maintained at the same high temperature during the cleaning process as during substrate processing. A high temperature of the pedestal 112 can cause more particles to be released (e.g., etched) from the surface of the pedestal 112, potentially contaminating the showerhead 104 even without a high flow rate of cleaning gas through the injector 132. Controlling the flow of cleaning gas through the injector 132, as described above, prevents particles released (e.g., etched) from the surface of the pedestal 112 from contaminating the showerhead 104.

[0096] Thus, the ability of the injector 132, constructed using a ceramic material such as alumina, to handle the additional corrosive stress imposed by a high flow rate of cleaning gas allows the temperature of the pedestal 112 to be maintained at the same high temperatures used during substrate processing without contaminating the showerhead 104. Although the high temperature of the pedestal 112 increases the number of particles that are ejected (e.g., etched) from the surface of the pedestal 112, the high flow rate of cleaning gas through the injector 132 prevents particles ejected (e.g., etched) from the surface of the pedestal 112 from contaminating the showerhead 104. In this manner, controlling the flow of cleaning gas through the injector 132 allows for uniform temperatures during substrate processing and the cleaning process.

[0097] Although controlling the flow of cleaning gas through the injector 132 mitigates particle contamination problems, the showerhead 104 may remain contaminated due to residual traces of cleaning gas that may become trapped and remain in the plenum 166 and holes 160, 172 of the showerhead 104. The second gas delivery system 170, as described below with reference to FIG. 3, helps further mitigate particle contamination problems. The second gas delivery system 170 also mitigates contamination of the showerhead 104 from stagnant cleaning gas that may become trapped in the plenum 166 and holes 172 of the showerhead 104, as follows.

[0098] 3 shows the second gas delivery system 170 in more detail. Although shown separately, the second gas delivery system 170 can be part of the second gas delivery system 130. The second gas delivery system 170 can be similar to the second gas delivery system 130. The substrate processing system 100 further includes valves 174, 176 and a manifold 178 connected to the second gas delivery system 170 and the plenum 166 of the showerhead 104, as shown. The second gas delivery system 170 is connected to the plenum 166 of the showerhead 104 via the valves 174, 176 and the manifold 178. The valves 174, 176 are connected to the second gas delivery system 170 and the manifold 178, as shown.

[0099] Valve 174 is connected to one or more gas sources in second gas delivery system 170 that supply one or more precursor gases. Although a single valve 174 is shown, multiple valves may be connected to multiple gas sources in second gas delivery system 170 that supply multiple precursor gases, respectively. The multiple valves may be controlled in a manner similar to valve 174, as will be described below. Valve 176 is connected to a gas source in second gas delivery system 170 that supplies an inert gas. Controller 190 controls valves 174, 176 as follows:

[0100] During substrate processing, the controller 190 opens the valve 174 and closes the valve 176. In response, the second gas delivery system 170 supplies one or more precursor gases to the plenum 166 of the showerhead 104 via the valve 174 and the plenum 178 during substrate processing.

[0101] During the cleaning process, the controller 190 closes valve 174 and opens valve 176. The second gas delivery system 170 supplies inert gas to the plenum 166 of the showerhead 104 via valve 176 and plenum 178 during the cleaning process. The inert gas is supplied at a slow rate as a trickle. The slow flow of inert gas through the showerhead 104 serves two purposes.

[0102] First, the flow of inert gas inhibits backflow (i.e., the flow of material, including particles ejected (e.g., etched) from the surface of the pedestal 112) into the showerhead 104 and dome 102. Essentially, the flow of inert gas inhibits the backflow of material from a lower portion of the processing chamber 103 into an upper portion of the processing chamber 103. Second, the flow of inert gas removes stagnant cleaning gas that may otherwise remain trapped in the plenum 166 and the holes 160, 172 of the showerhead 104.

[0103] In this manner, during the cleaning process, the controlled flow of cleaning gas through the injectors 132 and the slow flow of inert gas through the showerhead 104 significantly reduces and / or eliminates contamination of the showerhead 104 from particles ejected (e.g., etched) from the surface of the pedestal 112 and from stagnant cleaning gas that may otherwise remain trapped in the plenum 166 and holes 160, 172 of the showerhead 104.

[0104] Therefore, the elliptical shape of the dome 102, the ceramic material, and the coating 111 reduce the heat load on the dome 102 and etching of the inner wall of the dome 102. The design of the coil 134 further reduces the heat load on the dome 102 and increases the plasma volume within the dome 102. The injector 132, which includes a ceramic material, maintains a high flow rate of a corrosive cleaning gas that inhibits particle contamination of the showerhead 104. The flow of inert gas through the showerhead 104 further reduces contamination of the showerhead 104 by preventing stagnation of the cleaning gas within the showerhead. The controlled flow of cleaning gas through the injector 132 and the flow of inert gas through the showerhead 104 eliminate contamination of the showerhead 104 by particles released (e.g., etched) from the surface of the pedestal 112 and stagnation of cleaning gas that may otherwise remain trapped within the showerhead 104. The enclosure 125 with the fan 127 improves thermal uniformity across the dome 102.

[0105] The above features allow for the generation of an in-situ cleaning plasma while uniformly temperature-matching the showerhead 104 and pedestal 112, thereby reducing the heat load on the dome 102 during substrate processing and chamber cleaning. In this manner, by using the in-situ cleaning plasma, uniformly temperature-matching the showerhead 104 and pedestal 112, and reducing the heat load on the dome 102 during substrate processing and cleaning processes, the useful life of the dome 102 is extended. By using the in-situ cleaning plasma and uniformly temperature-matching the showerhead 104 and pedestal 112, the cleaning process is improved. Uniformly matching the temperatures of the showerhead 104 and pedestal 112 eliminates delays otherwise required by temperature transitions during substrate processing and cleaning processes, thereby increasing tool productivity. Section 4: Substrate Processing and Chamber Cleaning Methods

[0106] 4 illustrates a method 200 for processing a substrate and cleaning a processing chamber 103 in accordance with the present disclosure. Method 200 is also a method for operating substrate processing system 100. For example, controller 190 implements method 200 and controls elements of substrate processing system 100 in accordance with method 200.

[0107] At 202, method 200 determines whether it is time to process a substrate. For example, method 200 determines whether a substrate 114 is loaded into processing chamber 103 and the gap between the substrate 114 and the showerhead 104 is adjusted as required for the process (e.g., ALD) being used to process the substrate 114. If it is time to process the substrate, at 204, method 200 heats the pedestal 112 and showerhead 104 to a temperature required for the process (e.g., ALD) being performed on the substrate 114. For some processes, the pedestal 112 and showerhead 104 may be preheated to the temperature required for the process. At 206, method 200 supplies one or more process gases to injector 132 and, optionally, one or more precursors to showerhead 104, depending on the process requirements. At 208, method 200 supplies RF power to coil 134 to ignite plasma 142 (if used) within dome 102.

[0108] At 210, the method determines whether it is time to clean the processing chamber 103 (e.g., time to perform regular preventative maintenance on the processing chamber 103). If the processing chamber 103 does not need to be cleaned, then at 212, the method 200 continues processing the substrate (e.g., the same substrate or a new substrate), and the method 200 returns to 206. If the processing chamber 103 is to be cleaned, then at 214, the method 200 maintains the temperature of the pedestal 112 and showerhead 104 at 206 and 208 at the same temperature used in 204 to process the substrate. The method 200 does not change the temperature of the pedestal 112 and showerhead 104. The method 200 removes the substrate 114 from the processing chamber 103 and lowers the pedestal 112 relative to the showerhead 104.

[0109] At 216, the method 200 stops the flow of process and precursor gases to the injector 132 and the showerhead 104, and stops the RF supply, if used, at 208. At 218, the method 200 supplies one or more cleaning gases (e.g., a cleaning gas or a mixture of cleaning gases or other cleaning chemicals) to the injector 132 and supplies an inert gas from the second gas delivery system 120 directly to the showerhead 104. At 220, the method 200 supplies RF power to the coil 134 to ignite an in-situ cleaning plasma within the dome 102. The method 200 also controls the flow of one or more cleaning gases through the injector 132 and the flow of the inert gas through the showerhead 104, as described above.

[0110] At 222, the method determines whether it is time to stop the cleaning process (i.e., whether the chamber cleaning is complete). If it is not time to stop the cleaning process (i.e., if the chamber cleaning is not complete), method 200 returns to 218 and continues the cleaning process at 218 and 220. If it is time to stop the cleaning process, at 224, method 200 stops the flow of one or more cleaning gases to injector 132, stops the flow of inert gas to showerhead 104, and stops the RF supply to coil 134. At 226, method 200 maintains the temperatures of pedestal 112 and showerhead 104 used during the cleaning processes of 218 and 220, which are the same as the temperatures used to process the substrate at 206 and 208. Method 200 does not change the temperatures of pedestal 112 and showerhead 104. Subsequently, at 212, the method 200 continues processing the substrate (e.g., a new substrate) without delay because the pedestal 112 and showerhead 104 have already reached the temperatures used to process the substrate at 206 and 208.

[0111] The above-mentioned predetermined ranges will now be described in more detail. For example, a certain process (e.g., ALD) may require the showerhead 104 and pedestal 112 to have temperatures of 50° C. and 550° C., respectively, for processing a substrate. These temperatures of the showerhead 104 and pedestal 112 at which the substrate is processed by the process may be referred to as the predetermined temperatures of the showerhead 104 and pedestal 112 for the process.

[0112] The temperature controller 182 tightly controls the temperatures of these components, as described above with reference to Figure 1. However, in some instances, early in the cleaning process, these temperatures may fluctuate slightly and may not be exactly the same as the temperatures used during substrate processing. However, the variations are small and tightly controlled within a predetermined range that may be as narrow as 0-1% of the predetermined temperature.

[0113] For example, assume that a process (e.g., ALD) requires the showerhead 104 and pedestal 112 to have temperatures of 50 degrees Celsius and 550 degrees Celsius, respectively, for processing a substrate. Early in the cleaning process, the showerhead 104 temperature may vary by 0-1% from 50 degrees Celsius, and the pedestal 112 temperature may vary by 0-1% from 550 degrees Celsius. The temperature controller 182 can detect the variations using temperature sensors in the showerhead 104 and pedestal 112. Based on the detected variations, the temperature controller 182 can control one or more of the heater 184 in the pedestal 112 and the coolant supplied to the showerhead 104 and pedestal 112 to quickly return these temperatures to their respective predetermined temperatures. A similar procedure can be used after the cleaning process and at the beginning of processing a new substrate using the process (e.g., ALD).

[0114] Thus, for a given process, the temperatures of these components are essentially maintained close to or substantially equal to the process temperatures required, within a narrow predetermined range (e.g., 0-1%), during substrate processing and during the cleaning process. Therefore, after the cleaning process, substrate processing can be resumed quickly without the long delay typically required for the component temperatures to transition from a first set of temperatures used in the cleaning process to a second set of temperatures that are significantly different than those typically used in the substrate processing process. Furthermore, the temperature controller 182 can maintain the same (i.e., not change) the temperatures of the showerhead 104 and the pedestal 112 during substrate processing and the cleaning process. Therefore, after the cleaning process, substrate processing can be resumed immediately without the delay typically required for the component temperatures to transition from a first set of temperatures used in the cleaning process to a second set of temperatures that are significantly different than those typically used in the substrate processing process.

[0115] The foregoing description is merely exemplary in nature and is not intended to limit the disclosure, its application, or uses. The broad teachings of the disclosure can be embodied in a variety of forms. Accordingly, while the disclosure includes specific embodiments, the true scope of the disclosure should not be so limited, as other variations will become apparent from a study of the drawings, the specification, and the following claims.

[0116] It should be understood that one or more steps within a method may be performed in a different order (or simultaneously) without altering the principles of the present disclosure. Furthermore, although each embodiment is described above as having particular features, any one or more of those features described with respect to any embodiment of the present disclosure may be implemented and / or combined with features of any other embodiment, even if that combination is not explicitly stated. In other words, the described embodiments are not mutually exclusive, and permutations of one or more embodiments with each other remain within the scope of the present disclosure.

[0117] Spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers, etc.) are described using various terms such as "connected," "engaged," "coupled," "adjacent," "next to," "on top of," "above," "below," and "provided." Unless expressly described as "direct," when a relationship between first and second elements is described in the above disclosure, the relationship may be a direct relationship where no other intervening elements exist between the first and second elements, or an indirect relationship where one or more intervening elements (spatially or functionally) exist between the first and second elements. As used herein, the phrase "at least one of A, B, and C" should be interpreted to mean the logic (A or B or C) using a non-exclusive logical OR, and not to mean "at least one of A, at least one of B, and at least one of C."

[0118] In some embodiments, the controller is part of a system that may be part of the examples described above. Such a system may include semiconductor processing equipment, such as one or more processing tools, one or more chambers, one or more processing platforms, and / or specific processing components (wafer pedestals, gas flow systems, etc.). These systems may be integrated with electronics for controlling the operation of the system before, during, and after processing of the semiconductor wafer or substrate. This electronics may be referred to as a "controller," which may control various components or subcomponents of the system(s).

[0119] The controller may be programmed to control any of the processes disclosed herein, such as process gas delivery, temperature settings (e.g., heating and / or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow rate settings, fluid delivery settings, position and motion settings, wafer loading and unloading into the tool, and wafer loading and unloading into and out of other transport tools and / or load locks connected or interfaced with the particular system, depending on the processing requirements and / or type of system.

[0120] Broadly speaking, a controller may be defined as an electronic device having various integrated circuits, logic, memory, and / or software that, for example, receives instructions, issues instructions, controls operations, enables cleaning operations, enables endpoint measurements, etc. Integrated circuits may include chips in the form of firmware that store program instructions, digital signal processors (DSPs), chips defined as application specific integrated circuits (ASICs), and / or one or more microprocessors or microcontrollers that execute program instructions (e.g., software).

[0121] Program instructions may be instructions communicated to the controller in the form of various personalizations (or program files) that define operational parameters for performing a particular process on or for a semiconductor wafer or for a system. The operational parameters may, in some embodiments, be part of a recipe defined by a process engineer to accomplish one or more treatment processes in the fabrication of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or wafer types.

[0122] The controller, in some embodiments, may be part of, or coupled to, a computer integrated with, coupled to, or otherwise networked to the system, or a combination thereof. For example, the controller may be all or part of a host computer system in the "cloud" or at a fab that allows remote access to wafer processing. This computer may provide remote access to the system to monitor the current progress of fabrication operations, review the history of past fabrication operations, review trends or performance criteria from multiple fabrication operations, modify parameters of a current process, set up processing steps following a current process, or initiate a new process.

[0123] In some examples, a remote computer (e.g., a server) can provide process recipes to the system over a network, which may include a local network or the Internet. The remote computer may include a user interface that allows for entry or programming of parameters and / or settings, which are then communicated from the remote computer to the system. In some embodiments, the controller receives instructions in the form of data that defines parameters for each processing step that is performed during one or more operations. It should be understood that the parameters may be specific to the type of process being performed or the type of tool that the controller is configured to interface with or control.

[0124] Thus, as discussed above, the controller may be distributed, such as by including one or more separate controllers networked together and working toward a common purpose, such as the processes and controls described herein. An example of a controller distributed for such purposes includes one or more integrated circuits on the chamber that communicate with one or more integrated circuits located remotely (e.g., at the platform level or as part of a remote computer) combined to control the processes on the chamber.

[0125] Without limitation, exemplary systems may include a plasma etch chamber or module, a deposition chamber or module, a spin rinse chamber or module, a metal plating chamber or module, a clean chamber or module, a bevel edge etch chamber or module, a physical vapor deposition (PVD) chamber or module, a chemical vapor deposition (CVD) chamber or module, an atomic layer deposition (ALD) chamber or module, an atomic layer etch (ALE) chamber or module, an ion implantation chamber or module, a track chamber or module, and any other semiconductor processing system associated with or that may be used in the fabrication and / or manufacturing of semiconductor wafers.

[0126] As described above, depending on the process step or steps being performed by the tool, the controller may communicate with one or more of: other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, nearby tools, tools installed throughout the factory, a main computer, other controllers, or tools used in material transport to and from tool locations and / or load ports of wafers within a semiconductor fabrication factory.

Claims

1. 1. A substrate processing system, comprising: a processing chamber comprising a first portion and a second portion, the first portion including a dome, the dome comprising a ceramic material and having an elliptical shape; a pedestal configured to process a substrate disposed in the second portion of the processing chamber; a showerhead disposed at a base of the dome between the first and second portions of the processing chamber; an injector comprising the ceramic material mounted on the dome and configured to inject a process gas and a cleaning gas into the dome during substrate processing and cleaning of the processing chamber, respectively; a coil disposed around a portion of the dome; a radio frequency (RF) generator configured to supply RF power to the coil to generate a plasma within the dome during the substrate processing and during cleaning of the processing chamber; a controller configured to control temperatures of the pedestal and the showerhead to respective predetermined temperatures within predetermined ranges during the substrate processing and during cleaning of the processing chamber.

2. 10. The substrate processing system of claim 1, The substrate processing system, wherein the predetermined range is 0 to 1% of each of the predetermined temperatures.

3. 10. The substrate processing system of claim 1, The substrate processing system, wherein the controller is configured to maintain the temperatures of the pedestal and the showerhead unchanged at the respective predetermined temperatures during the substrate processing and during cleaning of the processing chamber.

4. 10. The substrate processing system of claim 1, The substrate processing system wherein the ceramic material is alumina.

5. 10. The substrate processing system of claim 1, The substrate processing system, wherein the inner wall of the dome is coated with a second material that is resistant to heat and corrosion.

6. 6. The substrate processing system according to claim 5, The substrate processing system wherein the second material is yttria.

7. 10. The substrate processing system of claim 1, a housing disposed around the dome and the coil and attached to an outer periphery of the showerhead; A substrate processing system wherein the enclosure comprises a plurality of fans arranged azimuthally symmetrically along a sidewall of the enclosure.

8. 10. The substrate processing system of claim 1, 10. The substrate processing system, further comprising: a gas delivery system configured to supply the cleaning gas through the injector at a rate that inhibits particles emitted from the pedestal from contaminating the showerhead during cleaning of the processing chamber.

9. 10. The substrate processing system of claim 1, 10. The substrate processing system, further comprising: a gas delivery system configured to supply an inert gas directly to the showerhead to inhibit particles released from the pedestal from contaminating the showerhead during cleaning of the processing chamber.

10. 10. The substrate processing system of claim 1, 10. The substrate processing system, further comprising: a gas delivery system configured to supply an inert gas directly to the showerhead to prevent the cleaning gas from stagnating in the showerhead after cleaning the processing chamber.

11. 10. The substrate processing system of claim 1, further comprising a gas delivery system; The shower head a first plenum configured to filter ions from the plasma and pass radicals to the second portion of the processing chamber; a second plenum configured to (i) receive a precursor directly from the gas delivery system and supply the precursor to the second portion of the processing chamber during substrate processing, and (ii) receive an inert gas directly from the gas delivery system during cleaning of the processing chamber.

12. 10. The substrate processing system of claim 1, the coil comprises multiple turns; A substrate processing system wherein the number of turns and the location of the turns around the dome distributes ion and heat load from the plasma throughout the dome.

13. 10. The substrate processing system of claim 1, the base includes a heater; the substrate processing system further comprising a fluid delivery system configured to supply a coolant to the pedestal and the showerhead; the controller is configured to control the flow of the heater and the coolant to maintain temperatures of the showerhead and the pedestal within the predetermined range of the respective predetermined temperatures during the substrate processing and during cleaning of the processing chamber.

14. 10. The substrate processing system of claim 1, the base includes a heater; the substrate processing system further comprising a fluid delivery system configured to supply a coolant to the pedestal and the showerhead; the controller is configured to control the heater and the coolant flow to maintain the temperatures of the pedestal and the showerhead unchanged at the respective predetermined temperatures during the substrate processing and during cleaning of the processing chamber.

15. 1. A method of cleaning a processing chamber configured for processing a substrate, the processing chamber comprising a pedestal and a showerhead, the method comprising: controlling the temperatures of the pedestal and the showerhead during cleaning of the processing chamber within predetermined ranges of respective predetermined temperatures used during processing of the substrate; supplying a cleaning gas into an elliptical dome of the processing chamber, the elliptical dome including a ceramic material, through an injector mounted on the elliptical dome, the injector including a ceramic material; generating a plasma within the elliptical dome by supplying radio frequency (RF) power to a coil disposed around the elliptical dome; and controlling the flow of the cleaning gas through the injector to inhibit contamination of the showerhead by particles emitted from the pedestal.

16. 16. The method of claim 15, The method wherein said predetermined range is 0-1% of each of said predetermined temperatures.

17. 16. The method of claim 15, The method further comprising maintaining the temperatures of the pedestal and the showerhead unchanged at the respective predetermined temperatures during processing of the substrate and during cleaning of the processing chamber.

18. 16. The method of claim 15, The method further includes spray coating the interior wall of the elliptical dome with a second material that is resistant to heat and corrosion.

19. 20. The method of claim 18, the ceramic material is alumina; The method wherein the second material is yttria.

20. 16. The method of claim 15, enclosing the elliptical dome and the coil within an enclosure mounted around the showerhead; cooling the elliptical dome using a plurality of fans positioned azimuthally symmetrically along a sidewall of the enclosure.

21. 16. The method of claim 15, The method further comprises further inhibiting contamination of the showerhead by the particles by supplying an inert gas directly to the showerhead.

22. 16. The method of claim 15, The method further comprises flowing an inert gas through the showerhead to prevent the cleaning gas from stagnating in the showerhead.

23. 16. The method of claim 15, The method further includes distributing ions and heat load from the plasma throughout the elliptical dome by distributing turns of the coil around the elliptical dome.

24. 16. The method of claim 15, After cleaning the processing chamber, stopping the supply of the cleaning gas and the RF power; controlling the temperatures of the pedestal and the showerhead within the predetermined ranges of the respective predetermined temperatures; The method further includes processing a second substrate in the processing chamber by supplying a process gas through the injector into the elliptical dome.

25. 25. The method of claim 24, The method further comprising delivering a precursor directly to the showerhead.

26. 25. The method of claim 24, igniting a second plasma within the elliptical dome by supplying the RF power to the coil; filtering ions from the second plasma and passing radicals to the second substrate.

27. 25. The method of claim 24, the method further comprising, during processing of the second substrate in the processing chamber, maintaining temperatures of the showerhead and the pedestal within the predetermined range of the respective predetermined temperatures by supplying a coolant through the pedestal and the showerhead.

28. 25. The method of claim 24, The method further includes maintaining the temperatures of the pedestal and the showerhead unchanged at the respective predetermined temperatures by supplying a coolant through the pedestal and the showerhead during processing of the second substrate in the processing chamber.

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