Baffles for providing uniform process gas flow over the substrate and around the pedestal

Abstract

The substrate processing chamber includes a pedestal and a baffle. The pedestal is disposed in the substrate processing chamber. The pedestal includes a base portion and a stem portion. The base portion has a larger diameter than the stem portion. The baffle is disposed around the pedestal to direct the flow of gas supplied to the substrate processing chamber around the pedestal from the periphery of the base portion of the pedestal, toward the stem portion of the pedestal, and toward one or more exhaust ports of the substrate processing chamber.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Application No. 63 / 415,792, filed October 13, 2022. The entire disclosures of the above-referenced applications are incorporated herein by reference.

[0002] FIELD OF THE DISCLOSURE The present disclosure relates generally to substrate processing systems, and more particularly to a baffle for providing uniform process gas flow over a substrate and around a pedestal in a substrate processing system. [Background technology]

[0003] The background art description provided herein is intended to generally present the context for the present disclosure. The work of the presently named inventors, to the extent that that work is described in this background art 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 to the present disclosure.

[0004] Atomic layer deposition (ALD) is a thin film deposition method that uses a sequence of gas chemical processes to deposit a thin film on the surface of a material (e.g., the surface of a substrate, such as a semiconductor wafer). Most ALD processes use at least two chemicals, called precursors (reactants), which react with the surface of the material, one precursor at a time, in a sequential, self-limiting manner. For example, a typical ALD process includes a series of dose and purge steps that are performed sequentially and repeatedly. By repeated exposure to distinct precursors, a thin film is gradually deposited on the surface of the material.

[0005] Thermal ALD (T-ALD) processes are generally performed in a heated processing chamber. The processing chamber is maintained at subatmospheric pressure using a vacuum pump and a controlled flow of inert gas. The substrate to be coated with the film is placed in the processing chamber and allowed to equilibrate to the temperature of the processing chamber before starting the ALD process. Plasma-enhanced ALD (PEALD) processes use a plasma during the dosing step. The plasma can be generated in situ in the processing chamber. Alternatively, the plasma can be generated remotely from the processing chamber and delivered to the processing chamber. Summary of the Invention

[0006] The substrate processing chamber includes a pedestal and a baffle. The pedestal is disposed in the substrate processing chamber. The pedestal includes a base portion and a stem portion. The base portion has a larger diameter than the stem portion. The baffle is disposed around the pedestal to direct a flow of gas supplied to the substrate processing chamber around the pedestal from the periphery of the base portion of the pedestal, toward the stem portion of the pedestal, and toward one or more exhaust ports of the substrate processing chamber.

[0007] In an additional feature, the baffle is annular and bowl-shaped.

[0008] In an additional feature, the flow of gas around the pedestal is uniform regardless of the location of the exhaust port in the substrate processing chamber.

[0009] In additional features, the substrate processing chamber further comprises a substrate disposed on a pedestal, wherein the flow of gas is uniform over the substrate regardless of the location of the exhaust port in the substrate processing chamber.

[0010] In an additional feature, the baffle is attached to a lower portion of the substrate processing chamber.

[0011] In an additional feature, the baffle comprises a plurality of legs attached to a bottom of the substrate processing chamber.

[0012] In additional features, the baffle comprises a plurality of legs attached to a lower portion of the substrate processing chamber, wherein gas flows through gaps between the legs and the lower portion of the substrate processing chamber toward an exhaust port of the substrate processing chamber.

[0013] In additional features, an outer edge of the baffle contacts a sidewall of the substrate processing chamber, and an inner portion of the baffle is separated from the pedestal.

[0014] In an additional feature, a lower portion of the pedestal base portion tapers radially inward, and an inner portion of the baffle extends radially inward toward the lower portion of the pedestal base portion and toward the pedestal stem portion.

[0015] In additional features, the baffle includes a rim and a base portion, the rim extending radially outward from a lower portion of the base portion of the baffle, and the base portion of the baffle extending radially inward toward a stem portion of the pedestal.

[0016] In an additional feature, an upper portion of the base portion of the baffle extends radially inwardly farther than the base portion of the baffle toward the stem portion of the pedestal.

[0017] In an additional feature, the baffle is monolithic.

[0018] In an additional feature, the baffle further comprises a plurality of legs attached to a bottom of the substrate processing chamber, the baffle and the legs being monolithic.

[0019] In an additional feature, an upper portion of the base portion of the baffle extends radially inward further toward the stem portion of the pedestal than the base portion of the baffle. The baffle further comprises a plurality of legs attached to a lower portion of the substrate processing chamber. The baffle and the legs are monolithic.

[0020] In additional features, the baffle comprises a plurality of legs attached to the bottom of the substrate processing chamber. The substrate processing chamber further comprises an annular plate disposed on the bottom of the substrate processing chamber and around a stem portion of the pedestal to support a plurality of lift pins for lifting a substrate disposed on the pedestal. The inner diameter of the base portion of the baffle is smaller than the outer diameter of the base portion of the pedestal and larger than the outer diameters of the stem portion and the annular plate. The height of the legs is greater than or equal to the thickness of the annular plate. Gas flows around the outer diameter of the annular plate and through gaps between the legs and the bottom of the substrate processing chamber toward an exhaust port of the substrate processing chamber.

[0021] In additional features, the outer diameter of the rim contacts a sidewall of the substrate processing chamber, the inner diameter of the rim is less than or equal to the outer diameter of the base portion of the pedestal, and the inner diameter of the base portion of the baffle is less than the inner diameter of the rim, less than the outer diameter of the base portion of the pedestal, and greater than the outer diameter of the stem portion.

[0022] In additional features, the upper portion of the base portion of the baffle extends radially inward further than the base portion of the baffle toward the stem portion of the pedestal. The outer diameter of the rim contacts a sidewall of the substrate processing chamber. The inner diameter of the rim is less than or equal to the outer diameter of the base portion of the pedestal. The inner diameters of the base portion and the upper portion of the base portion of the baffle are less than the inner diameter of the rim, less than the outer diameter of the base portion of the pedestal, and greater than the outer diameter of the stem portion.

[0023] In additional features, the substrate processing chamber further includes an annular plate disposed on a lower portion of the substrate processing chamber and around a stem portion of the pedestal to support a plurality of lift pins for lifting a substrate disposed on the pedestal. The outer diameter of the rim contacts a sidewall of the substrate processing chamber. The inner diameter of the rim is less than or equal to the outer diameter of the base portion of the pedestal. The inner diameter of the base portion of the baffle is less than the inner diameter of the rim, less than the outer diameter of the base portion of the pedestal, and greater than the outer diameter of the stem portion and the outer diameter of the annular plate.

[0024] In additional features, the substrate processing chamber further includes an annular plate disposed on a lower portion of the substrate processing chamber and around a stem portion of the pedestal to support a plurality of lift pins for lifting a substrate disposed on the pedestal. An upper portion of the base portion of the baffle extends radially inward farther than the base portion of the baffle and toward the stem portion of the pedestal. An outer diameter of the rim contacts a sidewall of the substrate processing chamber. An inner diameter of the rim is less than or equal to the outer diameter of the base portion of the pedestal. The inner diameters of the base portion and the upper portion of the base portion of the baffle are less than the inner diameter of the rim, less than the outer diameter of the base portion of the pedestal, and greater than the outer diameter of the stem portion and the outer diameter of the annular plate.

[0025] In an additional feature, the baffle comprises a plurality of legs, the legs comprising through holes for receiving fasteners for attaching the baffle to the bottom of the substrate processing chamber.

[0026] In additional features, the substrate processing chamber further comprises a showerhead disposed above the pedestal for supplying gases to the substrate processing chamber during processing of a substrate disposed on the pedestal and during cleaning of the substrate processing chamber, and a vacuum pump coupled to the exhaust port for pumping gases from the substrate processing chamber during processing and cleaning.

[0027] Further areas of applicability of the present disclosure will become apparent from the detailed description, the claims, and the drawings. The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

[0028] The present disclosure will become more fully understood from the detailed description and accompanying drawings. [Brief explanation of the drawings]

[0029] [Figure 1] FIG. 1 illustrates an example of a substrate processing system having a processing chamber with a baffle according to the present disclosure.

[0030] [Figure 2] FIG. 2 is a diagram illustrating a processing chamber with a baffle and the uniform gas flow provided by the baffle in the processing chamber.

[0031] [Figure 3] FIG. 3 is a cross-sectional view of the baffle.

[0032] [Figure 4] FIG. 4 is a top perspective view of the baffle showing the design, shape, and geometry of the baffle.

[0033] [Figure 5] FIG. 5 is a bottom perspective view of the baffle showing the design, shape, and geometry of the baffle.

[0034] [Figure 6] FIG. 6 is a top view of the baffle showing the design, shape, and geometry of the baffle.

[0035] [Figure 7] FIG. 7 is a bottom view of the baffle showing the design, shape, and geometry of the baffle. DETAILED DESCRIPTION OF THE INVENTION

[0036] In the drawings, reference numbers may be reused to identify similar and / or equivalent elements.

[0037] In most substrate processing systems (also called tools), a processing chamber includes one or more exhaust ports through which process gases supplied to the processing chamber are pumped out using a pump. Generally, the exhaust ports are not uniformly (symmetrically) positioned in the processing chamber. Depending on the placement (e.g., location) of the exhaust ports in the processing chamber, the flow of process gas around the pedestal in the processing chamber may be non-uniform. The non-uniform flow of process gas around the pedestal affects the distribution of process gas over the surface of a substrate placed on the pedestal and the distribution of process gas over the edge of the pedestal during substrate processing.

[0038] The present disclosure provides a baffle disposed around a pedestal to achieve uniform process gas flow over the substrate surface and around the pedestal. The baffle is designed (shaped) to allow uniform flow of process gas around the pedestal in a processing chamber even when exhaust ports are unevenly (asymmetrically) positioned in the processing chamber. The baffle is designed (shaped) to limit the risk of deposition on the baffle during substrate processing, which can potentially cause changes in process performance.

[0039] Without the baffle, flow uniformity around the pedestal, and therefore around the substrate, may not be sufficiently uniform, especially when exhaust ports are unevenly (asymmetrically) positioned in the processing chamber. Flow non-uniformity causes uneven deposition on the substrate. The baffle according to the present disclosure has a bowl-shaped geometry. This geometry restricts the flow of process gas between the baffle and the interior wall of the processing chamber. Due to the restriction provided by the baffle, uniform pumping of the process gas is achieved in conjunction with uneven placement of exhaust ports. The baffle does not use restrictive flow paths (e.g., holes) within the baffle. Therefore, the baffle eliminates the risk of deposition buildup, which can potentially cause changes in process performance over time. The baffle design is symmetric and does not have the risk of improper installation, as described below, which can potentially cause poor performance.

[0040] The baffle according to the present disclosure redirects the flow of process gas from the edge of the pedestal toward the center of the pedestal stem, and then collectively toward the exhaust port without providing holes in the baffle as restrictive flow paths. The absence of holes in the baffle not only eliminates the risk of deposition buildup, but also eliminates cavities that are potentially difficult to clean to achieve particle reduction. The baffle includes fixturing features (e.g., legs with through holes) to secure the baffle to the processing chamber. The fixturing features ensure static positioning of the baffle and reduce the risk of metal-to-metal rubbing, which can potentially cause particle contamination and migration of metal components to the surface of the substrate. The baffle has a simple and symmetrical geometry. The symmetrical design of the baffle prevents imprecise placement of the baffle in the processing chamber, which can potentially cause performance issues. These and other features of the baffle are described in detail below.

[0041] This disclosure is organized as follows: An example of a substrate processing system including a processing chamber is shown and described with reference to Figure 1. A baffle in the processing chamber is shown generally in Figure 1. The processing chamber including the baffle is shown and described in further detail with reference to Figure 2. The baffle design and uniform gas flow around the pedestal is shown and described with reference to Figure 2. The baffle geometry is shown and described in detail with reference to Figures 2-7.

[0042] 1 illustrates an example of a substrate processing system 100. The substrate processing system 100 includes a processing chamber 102. The processing chamber 102 includes a pedestal 104 and a showerhead 106. A substrate 108 is placed on the pedestal 104 during processing. The showerhead 106 delivers one or more process gases to the processing chamber 102 during substrate processing.

[0043] The pedestal 104 comprises a base portion 110 and a stem portion 112. The base portion 110 is generally cylindrical and has a diameter larger than that of the substrate 108. The stem portion 112 may be cylindrical or may be in the shape of the letter "Y," with the flared or forked end of the "Y" attached to the base portion 110. The other end of the stem portion 112 is attached to the bottom of the processing chamber 102. The stem portion 112 has a smaller diameter than the base portion 110. A pedestal lift assembly 113 is coupled to the stem portion 112 for moving the pedestal 104 relative to the showerhead 106.

[0044] The base portion 110 includes a heater 114 for heating the substrate 108. The base portion 110 also includes cooling channels (not shown) for circulating a coolant supplied by a coolant supply source 116 to regulate the temperature of the pedestal 104. The base portion 110 includes a temperature sensor 118 for detecting the temperature of the pedestal 104. The temperature sensor 118 is connected to a temperature controller 119. Based on the temperature detected by the temperature sensor 118, the temperature controller 119 controls the heater 114 and the flow of coolant from the coolant supply source 116 to the cooling channels in the base portion 110 to regulate the temperature of the pedestal 104.

[0045] The showerhead 106 comprises a base portion 120 and a stem portion 122. The base portion 120 is cylindrical and extends radially across the substrate 108. The base portion 120 has a diameter larger than the substrate 108. On the surface facing the substrate, the base portion 120 comprises a faceplate with a plurality of holes (not shown) through which one or more process gases are supplied to the processing chamber 102 during substrate processing. The stem portion 122 is also generally cylindrical and of a smaller diameter than the base portion 120. A first end of the stem portion 122 is connected to a central portion of the base portion 120. A second end of the stem portion 122 is connected to a top plate of the processing chamber 102.

[0046] Although not shown, the base portion 120 may include a heater for heating process gases. The base portion 120 may also include cooling channels for circulating coolant supplied by the coolant source 116 to regulate the temperature of the showerhead 106. The base portion 120 includes a temperature sensor 124 for detecting the temperature of the showerhead 106. The temperature sensor 124 is connected to a temperature controller 119. Based on the temperature detected by the temperature sensor 124, the temperature controller 119 controls the heater and the flow of coolant from the coolant source 116 to the cooling channels in the base portion 120 to regulate the temperature of the showerhead 106.

[0047] A gas delivery system 130 supplies one or more gases to the processing chamber 102. The gas delivery system 130 includes multiple gas sources 132-1, 132-2, ..., 132-N (collectively, gas sources 132), where N is a positive integer. The gas sources 132 supply various gases, including process gases, purge gases, precursors, cleaning gases, etc. The gas delivery system 130 includes multiple valves 134-1, 134-2, ..., 134-N (collectively, valves 134). The valves 134 are connected to the gas sources 132 and control the flow of gases supplied by the gas sources 132.

[0048] Gas delivery system 130 includes a plurality of mass flow controllers (MFCs) 136-1, 136-2, ..., 136-N (collectively MFCs 136). MFCs 136 are connected to valves 134 and control the mass flow rate of gas supplied by gas source 132 through valves 134. Gas delivery system 130 includes a manifold 138. Manifold 138 is connected to MFCs 136 and to showerhead 106. Manifold 138 supplies gas to showerhead 106.

[0049] Some processes may use one or more vaporized precursors during substrate processing. Accordingly, although not shown, the substrate processing system 100 may further include a vaporized precursor supply to supply one or more vaporized precursors. The vaporized precursor supply may also be connected to the manifold 138. When used, the manifold 138 may deliver the one or more vaporized precursors provided by the vaporized precursor supply to the showerhead 106.

[0050] In some processes, plasma may be used during substrate processing. Although not shown, the substrate processing system 100 may further include a radio frequency (RF) power supply for supplying RF power to generate plasma. For example, the RF power supply may supply RF power to the showerhead 106, and the pedestal 104 may be grounded or floating. Alternatively, the RF power supply may supply RF power to the pedestal 104, and the showerhead may be grounded or floating. In either case, when one or more process gases are supplied to the processing chamber 102 through the showerhead 106, the RF power supplied by the RF power supply activates the process gases in the processing chamber 102 to generate plasma between the showerhead and the substrate 108. In some processes, instead of generating plasma in the processing chamber 102, plasma may be generated remotely from (outside of) the processing chamber 102 and supplied to the processing chamber 102.

[0051] The processing chamber 102 includes a plurality of exhaust ports disposed around the lower periphery of the sidewall of the processing chamber 102 (e.g., exhaust port 103 is shown in FIG. 2 ). The exhaust ports are coupled to a foreline 144 connected to the processing chamber 102. The substrate processing system 100 further includes a vacuum pump 140 coupled to the processing chamber 102 via the foreline 144 through a valve 142. The vacuum pump 140 maintains a pressure (e.g., a vacuum) in the processing chamber 102 during substrate processing. The vacuum pump 140 also evacuates process gases and reaction by-products from the processing chamber 102 during substrate processing and during cleaning of the processing chamber 102.

[0052] The vacuum pump 140 also provides vacuum clamping when vacuum clamping is used to clamp the substrate 108 to the pedestal 104. Although not shown, the substrate may be clamped to the pedestal 104 using other clamping methods (e.g., electrostatic clamping provided by electrodes disposed in the base portion 110 of the pedestal 104, mechanical clamping, etc.). The processing chamber 102 further includes a controller 150. The controller 150 controls all of the elements of the substrate processing system 100 described above.

[0053] The processing chamber 102 further includes a baffle 160. The baffle 160 is only shown schematically in FIG. 1. The baffle 160 is shown and described in further detail with reference to FIGS. 2-7. Generally, exhaust ports are not uniformly (symmetrically) disposed in the processing chamber 102. Depending on the arrangement (e.g., location) of the exhaust ports in the processing chamber 102, the flow of process gas around the pedestal 104 may be non-uniform. The non-uniform flow of process gas around the pedestal 104 affects the distribution of process gas over the surface of the substrate 108 and over the edge of the pedestal 104 during substrate processing.

[0054] Thus, the baffle 160 is positioned around the pedestal 104 to achieve uniform gas flow over the substrate 108 and around the pedestal 104. As shown and described in further detail with reference to FIGS. 2-5 , the baffle 160 is designed (shaped) to achieve uniform gas flow over the substrate 108 and around the pedestal 104. The baffle 160 is designed (shaped) so that the gas flow around the pedestal 104 can be uniform regardless of the placement (location) of the exhaust ports. Furthermore, the baffle 160 is designed (shaped) to limit the risk of deposition on the baffle 160 during substrate processing, which could potentially cause changes in process performance.

[0055] Without the baffle 160, flow uniformity around the pedestal 104, and therefore around the substrate 108, may not be sufficiently uniform. Flow non-uniformity causes non-uniform deposition on the substrate 108. As described in detail below, the baffle 160 has a bowl-shaped geometry that restricts the flow of process gases and reaction by-products between the baffle 160 and the interior walls of the processing chamber 102. Due to the restriction provided by the baffle 160, uniform pumping of the process gases is achieved, along with the non-uniform placement of exhaust ports. The baffle 160 does not use restrictive flow paths (e.g., holes) within the baffle 160. Therefore, the baffle 160 eliminates the risk of deposition buildup, which can potentially cause changes in process performance over time. The design of the baffle 160 is symmetrical and does not have the risk of improper installation, as described below, which can potentially cause poor performance.

[0056] In particular, as described in detail below, the baffle 160 redirects the flow of process gas from the edge of the pedestal 104 toward the center of the stem portion 112 of the pedestal 104, and then redirects it collectively toward the exhaust port without providing holes or other flow-restricting features (e.g., perforations) in the baffle 160. The absence of holes in the baffle 160 not only eliminates the risk of deposit buildup, but also eliminates cavities that are potentially difficult to clean to achieve particle reduction. As shown in FIGS. 2-7, the baffle 160 includes fastening features (legs with through-holes) for securing the baffle 160 to the processing chamber 102. The fastening features of the baffle 160 ensure static positioning of the baffle 160 in the processing chamber 102. Although the baffle 160 and the walls of the processing chamber 102 are made from metallic materials, the adhesive features of the baffle 160 also reduce the risk of metal-on-metal rubbing due to friction between the baffle 160 and the walls of the processing chamber 102, which can potentially result in particle contamination and transfer of metal components to the surface of the substrate 108. The symmetrical design of the baffle 160 prevents imprecise placement of the baffle 160, which can potentially cause performance issues. These and other features of the baffle are described in more detail below with reference to FIGS. 2-7.

[0057] 2 shows in more detail the processing chamber 102 with the baffle 160, along with the design of the baffle 160 and the uniform gas flow around the pedestal 104. Elements in FIG. 2 already shown in FIG. 1 will not be described again for brevity. Additional elements shown in FIG. 2 are described below.

[0058] In addition to the baffle 160, Figure 2 shows two additional elements not shown in Figure 1. First, the processing chamber 102 includes a cylindrical block 170 that surrounds the stem portion 112 of the pedestal 104. The cylindrical block 170 interfaces with the stem portion 112 of the pedestal 104 and provides a seal for the processing chamber 102 when the pedestal 104 is moved up and down by the pedestal lift assembly 113.

[0059] Second, the processing chamber 102 includes a lift pin assembly. The lift pin assembly includes a lift pin mounting plate 180 and a plurality of lift pins disposed on the lift pin mounting plate 180. For example, three lift pins 182-1, 182-2, and 182-3 (a third lift pin 182-3 is not visible in the depicted view and therefore not shown, but is present) may be used. Lift pins 182-1, 182-2, and 182-3 are collectively referred to as lift pins 182.

[0060] Lift pin mounting plate 180 is an annular plate that surrounds cylindrical block 170. Lift pin mounting plate 180, together with baffle 160, directs gas flow toward the exhaust port, as described in further detail below. Lift pins 182 pass through base portion 110 of pedestal 104. Lift pins 182 lower and raise substrate 108 relative to pedestal 104 as pedestal 104 is moved up and down by pedestal lift assembly 113 as follows:

[0061] When a substrate 108 is to be loaded into the processing chamber 102, the pedestal 104 is lowered so that the tips of the lift pins 182 protrude above the base portion 110 of the pedestal 104. A computer-controlled robot arm (not shown) loads the substrate 108 into the processing chamber 102, with the substrate 108 resting on the tips of the lift pins 182. After the robot arm retracts, the pedestal 104 is moved upward until the tips of the lift pins 182 retract below the upper surface of the base portion 110 of the pedestal 104, with the substrate 108 resting on the upper surface of the base portion 110 of the pedestal 104.

[0062] After processing, when the substrate 108 is to be removed from the processing chamber 102, the pedestal 104 is lowered so that the tips of the lift pins 182 protrude above the base portion 110 of the pedestal, and the substrate 108 rests on the tips of the lift pins 182. A robot arm is inserted into the gap between the substrate 108 and the upper surface of the base portion 110 of the pedestal 104, and the substrate 108 is removed from the processing chamber 102.

[0063] Before describing the baffle 160 in detail, an example geometry of the base portion 110 of the pedestal 104 will be described in detail. For example, the base portion 110 of the pedestal 104 comprises an upper portion 111 and a lower portion 115. The upper portion 111 of the base portion 110 is cylindrical. The substrate 108 rests on the upper portion 111 of the base portion 110 during processing. The lower portion 115 of the base portion 110 extends downward from the bottom of the upper portion 111 toward the bottom of the processing chamber 102 as follows:

[0064] For example, the lower portion 115 of the base portion 110 has a trapezoidal cross-section. In particular, in the example shown, the lower portion 115 of the base portion 110 tapers radially inward from the bottom of the upper portion 111 toward the stem portion 112 of the pedestal 104 over a first distance. The lower portion 115 of the base portion 110 tapers downward toward the bottom of the processing chamber 102 over the first distance. After the first distance, the lower portion 115 of the base portion 110 extends radially inward parallel to the upper portion 111. After the first distance, the lower portion 115 of the base portion 110 extends toward and to the stem portion 112 of the pedestal 104. Thus, the upper end of the lower portion 115 has the same outer diameter (OD) as the upper portion 111, but the lower end of the lower portion 115 has a smaller diameter than the upper end of the lower portion 115.

[0065] The geometry of baffle 160 will now be described in detail with reference to FIGS. 2-7. FIGS. 2 and 3 show cross-sectional views of baffle 160. FIGS. 4 and 5 show top and bottom perspective views of baffle 160, respectively. FIGS. 6 and 7 show top and bottom views of baffle 160, respectively. Different elements of baffle 160 are visible in different views of FIGS. 2-7. FIGS. 3-7 collectively show all of the elements or features of baffle 160 described below. Not all elements or features of baffle 160 are visible in each of FIGS. 3-7. Only elements or features of baffle 160 that are visible in FIGS. 3-7 are labeled in FIGS. 3-7. Accordingly, FIGS. 3-7 will be referenced in the following discussion but will not be separately described for brevity.

[0066] The geometry of the baffle 160 described below can be the same if the base portion of the pedestal 104 is perfectly cylindrical (i.e., if both the upper portion 111 and the lower portion 115 of the base portion 110 are cylindrical). The baffle 160 can direct the flow of gas as described below even if the base portion of the pedestal 104 is perfectly cylindrical.

[0067] The baffle 160 is generally annular and bowl-shaped. In particular, the baffle 160 comprises a rim 200 (also referred to as the annular portion) and a base portion 202. The baffle 160 is monolithic. The baffle 160 is manufactured as a single piece comprising the rim 200 and the base portion 202. The rim 200 extends radially outward from the base portion 202, forming a flange-like structure. The base portion 202 is annular. The base portion 202 extends downward and radially inward from the base of the rim 200, as will be described in more detail below.

[0068] The OD of the rim 200 is larger than the OD of the base portion 110 of the pedestal 104 (i.e., the OD of the upper portion 111 of the base portion 110 of the pedestal 104). The rim 200 contacts the sidewall of the processing chamber 102. The inner diameter (ID) of the rim 200 matches the OD of the upper portion 111 of the base portion 110 of the pedestal 104. In some examples, although not shown, the baffle 160 is positioned below the upper portion 111 and abuts the tapered lower portion 115 of the base portion 110, so the ID of the rim 200 can be smaller than the OD of the upper portion 111. The rim 200 may be rounded at the ID as shown, but need not be rounded.

[0069] The base portion 202 extends radially inward from the base of the rim 200 a second distance toward the stem portion 112 of the pedestal 104. In the example shown, an upper portion 204 of the base portion 202 of the baffle 160 extends radially inward from the ID of the base portion 202 toward the stem portion 112 of the pedestal 104. The upper portion 204 of the base portion 202 of the baffle 160 extends radially inward farther toward the stem portion 112 of the pedestal 104 than the remainder of the base portion 202, forming a flange-like structure. The upper portion 204 of the base portion 202 extends a third distance from the base portion 202 toward the stem portion 112 of the pedestal 104. The third distance is less than the second distance.

[0070] In some implementations, the upper portion 204 of the base portion 202 of the baffle 160 may be omitted, and the baffle 160 may still direct the flow of gas as described below. In some implementations, the lower portion 115 of the base portion 110 of the pedestal 104 may be cylindrical instead of tapered, and further, the upper portion 204 of the base portion 202 of the baffle 160 may be omitted, and the baffle 160 may still direct the flow of gas as described below.

[0071] The upper portion 204 of the base portion 202 of the baffle 160 is parallel to the upper portion 111 of the base portion 110 of the pedestal 104. The upper portion 204 of the base portion 202 is also parallel to the upper surface of the rim 200. The upper surface of the base portion 202 is also parallel to the upper surface of the rim 200. The OD of the base portion 202 can be smaller than the OD of the rim 200, but it does not have to be smaller. In some examples, not shown, the OD of the base portion 202 can be the same as the OD of the rim 200.

[0072] The ID of the base portion 202 of the baffle 160 and the ID of the upper portion 204 of the base portion 202 of the baffle 160 are smaller than the ID of the rim 200. The ID of the base portion 202 and the ID of the upper portion 204 of the base portion 202 of the baffle 160 are smaller than the OD of the upper portion 111 of the base portion 110 of the pedestal 104. The ID of the base portion 202 and the ID of the upper portion 204 of the base portion 202 of the baffle 160 are larger than the OD of the stem portion 112 of the pedestal 104. The ID of the base portion 202 and the ID of the upper portion 204 of the base portion 202 of the baffle 160 are also larger than the OD of the lift pin mounting plate 180.

[0073] In some implementations, although not shown, to further facilitate and enhance gas flow as described below, the upper portion 204 of the base portion 202 of the baffle 160 may taper radially inward and downward toward a lower portion of the processing chamber 102. Additionally, although not shown, the upper surface of the base portion 202 may taper radially inward and downward toward a lower portion of the processing chamber 102. In some examples, although not shown, one or both of the upper portion 204 and the upper surface of the base portion 202 may taper radially inward and downward toward a lower portion of the processing chamber 102 at the same or different angles (i.e., with the same or different slopes).

[0074] The rim 200 and the base portion 202 can have different thicknesses (heights). For example, the rim 200 can be thicker (of greater height) than the base portion 202 as shown. In some examples, not shown, the rim 200 and the base portion 202 can have the same thickness (height). Thus, due to the geometry of the rim 200 and the base portion 202 as described above, the baffle 160 is generally annular and bowl-shaped.

[0075] Baffle 160 further includes a plurality of legs. For example, baffle 160 can include four legs, although any number of legs greater than or equal to two can be used. In the cross-sectional view of baffle 160 shown in FIG. 2 and in the perspective view of the baffle shown in FIG. 4, only two legs 210-1 and 210-2 are visible. Third leg 210-3 and fourth leg 210-4 are not visible (overlapping one another) in FIGS. 2 and 4, but are visible in the cross-sectional view of baffle 160 shown in FIG. 3 and individually visible in the perspective view of baffle 160 shown in FIG. 5. All four legs 210-1, 210-2, 210-3, and 210-4 are visible in FIG. 7. Legs 210-1, 210-2, 210-3, and 210-4 (and any additional legs that may be used but are not shown) are collectively referred to as legs 210. Legs 210 may also be monolithic with baffle 160.

[0076] The legs 210 extend from the lower portion of the base portion 202 of the baffle 160. The legs 210 extend downward toward the lower portion of the processing chamber 102. The legs 210 may extend vertically from the base portion 202, as shown. In some examples, not shown, the legs 210 may be sloped and extend radially outward from the base portion 202 downward toward the lower portion of the processing chamber 102 to further facilitate and enhance gas flow, as described below. Whether the legs 210 are vertical or sloped, the height of the legs 210 is greater than or equal to the thickness (height) of the lift pin mounting plate 180.

[0077] Through-holes are drilled through base portion 202 and each leg 210. Examples of through-holes are shown at 212-1 and 212-2 in Figures 2 and 3. Leg 210-2 is visible in Figure 4, but through-hole 212-2 for leg 210-2 is not visible in Figure 4. Leg 210-3 is not visible in Figure 4, but through-hole 212-3 for leg 210-3 is visible in Figure 4. Third through-hole 212-3 and fourth through-hole 212-4 for third leg 210-3 and fourth leg 210-4 are visible (overlapping with each other) in the cross-sectional view of baffle 160 shown in Figure 3 and individually visible in the perspective view of baffle 160 shown in Figure 5. All four through-holes 212-1, 212-2, 212-3, and 212-4 are visible in Figure 6. Through-holes 212-1, 212-2, 212-3, and 212-4 (and any additional through-holes for any additional legs that may be used but are not shown) are collectively referred to as through-holes 212.

[0078] Fasteners (not shown) can be inserted into the through-holes 212 to secure (fasten) the baffle 160 to the bottom of the processing chamber 102. The fasteners can be inserted and secured from the bottom of the processing chamber 102 or from the top of the base portion 202 of the baffle 160. As explained above, due to the symmetrical design of the baffle 160, the legs 210 of the baffle 160 can be secured anywhere in the bottom of the processing chamber 102, regardless of (i.e., regardless of) the location of the exhaust portion in the processing chamber 102.

[0079] When installed, the top surface of the rim 200 of the baffle 160 is at a level below the base of the upper portion 111 of the base portion 110 of the pedestal 104. The ID of the rim 200 surrounds the lower portion 115 of the base portion 110 of the pedestal 104. The ID of the rim 200 does not contact the lower portion 115 of the base portion 110 of the pedestal 104. Instead, a gap exists between the ID of the rim 200 and the periphery of the lower portion 115 of the base portion 110 of the pedestal 104. The gap separates the ID of the rim 200 from the lower portion 115 of the base portion 110 of the pedestal 104.

[0080] Furthermore, the upper surface of the base portion 202 and the upper portion 204 of the base portion 202 of the baffle 160 also do not contact the lower portion 115 of the base portion 110 of the pedestal 104. Instead, a gap exists between the lower portion 115 of the base portion 110 of the pedestal 104 and each of the upper surface of the base portion 202 and the upper portion 204 of the base portion 202 of the baffle 160. The gap separates the lower portion 115 of the base portion 110 of the pedestal 104 from each of the upper surface of the base portion 202 and the upper portion 204 of the base portion 202 of the baffle 160.

[0081] 2, gaps exist between the bottom of the base portion 202 of the baffle 160 and the bottom of the processing chamber 102 due to the legs 210. These gaps and the other gaps described above, along with the geometry of the baffle 160 described above, promote and enhance gas flow, as described below. Gas flow is further promoted and enhanced by the lift pin mounting plate 180, as described below.

[0082] 2. In particular, the showerhead 106 delivers process gases to the processing chamber 102. The vacuum pump 140 (shown in FIG. 1) evacuates the processing chamber 102 from the process gases and reaction by-products produced by reactions between the process gases and the substrate 108. The process gases and reaction by-products flow over the substrate 108, around the pedestal 104 and baffle 160, and out of the exhaust port of the processing chamber 102 as follows:

[0083] Process gases delivered by the showerhead 106 flow uniformly in the direction indicated by arrows 220-1 and 220-2 over the substrate 108. Process gases and reaction by-products flow uniformly between the showerhead 106 and the substrate 108 toward the sidewalls of the processing chamber 102 in the direction indicated by arrows 220-1 and 220-2.

[0084] The process gases and reaction by-products then flow downward around the upper portion 111 of the base portion 110 of the pedestal 104 toward the bottom of the processing chamber 102 in the direction indicated by arrows 220-3 and 220-4. The process gases and reaction by-products flow through the gap between the sidewall of the processing chamber and the OD of the upper portion 111 of the base portion 110 of the pedestal 104 in the direction indicated by arrows 220-3 and 220-4.

[0085] The process gases and reaction by-products then flow through the gap between the ID of the rim 200 of the baffle 160 and the periphery of the tapered lower portion 115 of the base portion 110 of the pedestal 104. The process gases and reaction by-products flow downward toward the bottom of the processing chamber 102 in the direction indicated by arrows 220-5 and 220-6.

[0086] The process gases and reaction by-products then flow through the gap between the upper portion 204 of the base portion 202 of the baffle 160 and the lower periphery of the tapered lower portion 115 of the base portion 110 of the pedestal 104. In particular, the process gases and reaction by-products flow downward around the upper portion 204 of the base portion 202 of the baffle 160 toward the lower portion of the processing chamber 102 in the direction indicated by arrows 220-7 and 220-8. Furthermore, the lift pin mounting plate 180 directs the process gases and reaction by-products flowing around the upper portion 204 of the base portion 202 of the baffle 160 toward the legs 210 of the baffle 160 in the direction indicated by arrows 220-9 and 220-10.

[0087] The process gases and reaction by-products then flow through the gap provided by legs 210 between the bottom of base portion 202 of baffle 160 and the bottom of processing chamber 102 toward an exhaust port, such as exhaust port 103 and any other exhaust port in the processing chamber. Thus, regardless of the location of legs 210 of baffle 160 and regardless of the location of the exhaust port in processing chamber 102, the process gases and reaction by-products flow uniformly over substrate 108, around pedestal 104, and ultimately exit processing chamber 102 through the exhaust port more effectively than when baffle 160 is not used.

[0088] Thus, the bowl-shaped geometry of baffle 160 restricts the flow of process gases and reaction by-products between baffle 160 and the interior walls of processing chamber 102. In particular, baffle 160 redirects the flow of process gases and reaction by-products from the outer edge of pedestal 104 toward the center of stem portion 112 of pedestal 104, as shown by the arrows and described above, and then collectively toward the exhaust port. The restriction provided by baffle 160 achieves uniform pumping of process gases and reaction by-products regardless of whether exhaust ports are unevenly (asymmetrically) positioned throughout processing chamber 102.

[0089] Additionally, because baffle 160 does not utilize restrictive flow paths (e.g., holes) within baffle 160, baffle 160 eliminates the risk of deposit buildup that can potentially cause changes in process performance over time and alter flow conductance. The absence of holes in baffle 160 also eliminates cavities that are potentially difficult to clean to achieve particle reduction.

[0090] Additionally, the symmetrical design (geometry) of the baffle 160 eliminates the risk of improper placement of the baffle in the processing chamber 102, which can potentially result in poor performance. In particular, the legs 210 of the baffle 160 ensure static positioning of the baffle 160 and also reduce the risk of metal-on-metal rubbing, which can potentially result in particle contamination and migration of metal components to the surface of the substrate 108.

[0091] The baffle 160 is useful for directing the flow of gases and reaction byproducts not only during substrate processing but also during cleaning of the processing chamber 102. For example, during cleaning of the processing chamber 102, no substrate 108 is used. In some cleaning processes, a dummy substrate may be used. One or more cleaning gases are supplied to the processing chamber 102 through the showerhead 106. The cleaning gases react with residues deposited throughout the processing chamber 102 during substrate processing. The vacuum pump 140 removes the cleaning gases, residues released from components of the processing chamber 102, and any reaction byproducts formed by reactions between the cleaning gases and the residues. The vacuum pump 140 removes these materials from the processing chamber 102 through an exhaust port of the processing chamber 102. The baffle 160 directs the flow of these materials during the cleaning process, as described above.

[0092] 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 may be implemented in a variety of forms. Thus, while the disclosure includes specific examples, the true scope of the disclosure should not be so limited, as other modifications will become apparent upon review of the drawings, the specification, and the following claims.

[0093] It should be understood that one or more steps within a method may be performed in a different order (or in parallel) without altering the principles of the present disclosure. Furthermore, although each of the embodiments has been described above as having certain features, any one or more of the features described with respect to any embodiment of the present disclosure may be implemented in and / or combined with any feature of any other embodiment, even if the combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and substituting one or more embodiments with each other remains within the scope of the present disclosure.

[0094] Spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers, etc.) are described using a variety of terms, including "connected," "engaged," "coupled," "adjacent," "next to," "on top of," "above," "below," and "disposed." Unless explicitly described as being "direct," when a relationship between a first element and a second element is described in the above disclosure, the relationship may be a direct relationship, where no other intervening elements exist between the first element and the second element, but may also be an indirect relationship, where one or more intervening elements exist (either spatially or functionally) between the first element and the second element. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical non-exclusive OR (A OR B OR C), and not to mean "at least one of A, at least one of B, and at least one of C."

[0095] In some implementations, the controller is part of a system, which may be part of the examples described above. Such a system may comprise semiconductor processing equipment, including one or more processing tools, one or more chambers, one or more platforms, and / or specific processing components (such as a wafer pedestal, a gas flow system, etc.) for processing. These systems may be integrated with electronics for controlling their operation before, during, and after processing of semiconductor wafers or substrates. The electronics may be referred to as a “controller,” which may control various components or subportions of one or more systems.

[0096] The controller may be programmed to control any of the processes disclosed herein, including 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 operation settings, wafer transfers in and out of tools and other transfer tools and / or load locks connected to or interfaced with the particular system, depending on the processing requirements and / or type of system.

[0097] Generally, a controller may be defined as an electronic device having various integrated circuits, logic, memory, and / or software that receives instructions, issues instructions, controls operations, enables cleaning operations, enables endpoint measurements, etc. Integrated circuits may include firmware that stores program instructions, digital signal processors (DSPs), chips defined as application specific integrated circuits (ASICs), and / or chips in the form of one or more microprocessors or microcontrollers that execute program instructions (e.g., software).

[0098] The program instructions may be instructions communicated to the controller in the form of various individual settings (or program files) that define operational parameters for performing a particular process on or for a semiconductor wafer or for the system. The operational parameters, in some embodiments, may be part of a recipe defined by a process engineer to accomplish one or more processing steps during the fabrication of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or dies of the wafer.

[0099] The controller, in some implementations, may be part of, coupled to, or a combination of a computer that is integrated with, coupled to, or otherwise networked to the system. For example, the controller may be in the "cloud" or in all or part of a fab host computer system that can enable remote access of wafer processing. The computer may enable remote access to the system to monitor the current progress of a fabrication operation, examine the history of past fabrication operations, and examine trends or performance metrics from multiple fabrication operations in order to change parameters of a current process, set up processing steps following a current process, or initiate a new process.

[0100] In some examples, a remote computer (e.g., a server) can provide the process recipe to the system over a network, which may include a local network or the Internet. The remote computer can include a user interface that allows entry or programming of parameters and / or settings, which are then communicated from the remote computer to the system. In some examples, the controller receives instructions in the form of data that specify parameters for each of the processing steps to be performed during one or more operations. It should be understood that the parameters can be specific to the type of process to be performed and the type of tool the controller is configured to interface with or control.

[0101] Thus, as described above, the controller may be distributed, such as by having one or more individual controllers networked together and working toward a common purpose, such as the processes and controls described herein. An example of a distributed controller for such purposes would be one or more integrated circuits on the chamber in communication with one or more remotely located integrated circuits (such as at the platform level or as part of a remote computer) that are combined to control the process on the chamber.

[0102] 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 cleaning 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 that may be associated with or used in the fabrication and / or manufacturing of semiconductor wafers.

[0103] As described above, depending on the process step or steps to be 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 located throughout the factory, a main computer, another controller, or tools used in material transport carrying containers of wafers to and from tool locations and / or load ports in a semiconductor fabrication factory.

Claims

1. 1. A substrate processing chamber comprising: a pedestal disposed in the substrate processing chamber, the pedestal having a base portion and a stem portion, the base portion having a larger diameter than the stem portion; a baffle disposed about the pedestal to direct a flow of gas supplied to the substrate processing chamber around the pedestal from the periphery of the base portion of the pedestal, toward the stem portion of the pedestal, and toward one or more exhaust ports of the substrate processing chamber; 1. A substrate processing chamber comprising:

2. 10. The substrate processing chamber of claim 1, wherein the baffle is annular and bowl-shaped.

3. 10. The substrate processing chamber of claim 1, wherein the flow of gas around the pedestal is uniform regardless of the location of the exhaust port in the substrate processing chamber.

4. 10. The substrate processing chamber of claim 1, further comprising a substrate disposed on the pedestal, wherein the flow of gas is uniform over the substrate regardless of the location of the exhaust port in the substrate processing chamber.

5. 10. The substrate processing chamber of claim 1, wherein the baffle is attached to a lower portion of the substrate processing chamber.

6. 10. The substrate processing chamber of claim 1, wherein the baffle comprises a plurality of legs attached to a bottom of the substrate processing chamber.

7. 10. The substrate processing chamber of claim 1, wherein the baffle comprises a plurality of legs attached to a lower portion of the substrate processing chamber, and the gas flows through gaps between the legs and the lower portion of the substrate processing chamber toward the exhaust port of the substrate processing chamber.

8. 10. The substrate processing chamber of claim 1, wherein an outer edge of the baffle contacts a sidewall of the substrate processing chamber and an inner portion of the baffle is separated from the pedestal.

9. 2. The substrate processing chamber of claim 1, wherein a lower portion of the base portion of the pedestal tapers radially inward, and an inner portion of the baffle extends radially inward toward the lower portion of the base portion of the pedestal and toward the stem portion of the pedestal.

10. 10. The substrate processing chamber of claim 1, wherein the baffle has a rim and a base portion, the rim extending radially outward from a lower portion of the base portion of the baffle, and the base portion of the baffle extending radially inward toward the stem portion of the pedestal.

11. 11. The substrate processing chamber of claim 10, wherein an upper portion of the base portion of the baffle extends radially inwardly further toward the stem portion of the pedestal than the base portion of the baffle.

12. 11. The substrate processing chamber of claim 10, wherein the baffle is monolithic.

13. 11. The substrate processing chamber of claim 10, wherein the baffle further comprises a plurality of legs attached to a bottom of the substrate processing chamber, and wherein the baffle and the legs are monolithic.

14. 11. The substrate processing chamber of claim 10, wherein an upper portion of the base portion of the baffle extends radially inward further than the base portion of the baffle toward the stem portion of the pedestal, the baffle further comprising a plurality of legs attached to a lower portion of the substrate processing chamber, and the baffle and the legs are monolithic.

15. 10. The substrate processing chamber of claim 1, wherein the baffle has a plurality of legs attached to a bottom of the substrate processing chamber, the substrate processing chamber comprising: an annular plate disposed on the bottom of the substrate processing chamber and around the stem portion of the pedestal for supporting a plurality of lift pins for lifting a substrate disposed on the pedestal; Furthermore, an inner diameter of the base portion of the baffle that is smaller than an outer diameter of the base portion of the pedestal and larger than an outer diameter of the stem portion and an outer diameter of the annular plate; the height of the legs is greater than or equal to the thickness of the annular plate; the gas flows around the outer diameter of the annular plate and through a gap between the leg and the bottom of the substrate processing chamber toward the exhaust port of the substrate processing chamber. Substrate processing chamber.

16. 11. The substrate processing chamber of claim 10, an outer diameter of the rim contacting a sidewall of the substrate processing chamber; an inner diameter of the rim is less than or equal to an outer diameter of the base portion of the pedestal; an inner diameter of the base portion of the baffle is smaller than the inner diameter of the rim, smaller than the outer diameter of the base portion of the pedestal, and larger than the outer diameter of the stem portion; Substrate processing chamber.

17. 11. The substrate processing chamber of claim 10, an upper portion of the base portion of the baffle extends radially inwardly farther than the base portion of the baffle toward the stem portion of the pedestal; an outer diameter of the rim contacting a sidewall of the substrate processing chamber; an inner diameter of the rim is less than or equal to an outer diameter of the base portion of the pedestal; an inner diameter of the base portion and an inner diameter of the upper portion of the base portion of the baffle are smaller than the inner diameter of the rim, smaller than the outer diameter of the base portion of the pedestal, and larger than the outer diameter of the stem portion; Substrate processing chamber.

18. 11. The substrate processing chamber of claim 10, further comprising an annular plate disposed on a bottom of the substrate processing chamber and around the stem portion of the pedestal to support a plurality of lift pins for lifting a substrate disposed on the pedestal; an outer diameter of the rim contacting a sidewall of the substrate processing chamber; an inner diameter of the rim is less than or equal to an outer diameter of the base portion of the pedestal; an inner diameter of the base portion of the baffle is smaller than the inner diameter of the rim, smaller than the outer diameter of the base portion of the pedestal, and larger than the outer diameter of the stem portion and the outer diameter of the annular plate; Substrate processing chamber.

19. 11. The substrate processing chamber of claim 10, further comprising an annular plate disposed on a bottom of the substrate processing chamber and around the stem portion of the pedestal to support a plurality of lift pins for lifting a substrate disposed on the pedestal; an upper portion of the base portion of the baffle extends radially inwardly farther than the base portion of the baffle toward the stem portion of the pedestal; an outer diameter of the rim contacting a sidewall of the substrate processing chamber; an inner diameter of the rim is less than or equal to an outer diameter of the base portion of the pedestal; an inner diameter of the base portion and an inner diameter of the upper portion of the base portion of the baffle are smaller than the inner diameter of the rim, smaller than the outer diameter of the base portion of the pedestal, and larger than the outer diameter of the stem portion and the outer diameter of the annular plate; Substrate processing chamber.

20. 10. The substrate processing chamber of claim 1, wherein the baffle comprises a plurality of legs, the legs comprising through holes for inserting fasteners to attach the baffle to a bottom of the substrate processing chamber.

21. 10. The substrate processing chamber of claim 1, a showerhead disposed above the pedestal for supplying the gases to the substrate processing chamber during processing of a substrate disposed on the pedestal and during cleaning of the substrate processing chamber; a vacuum pump coupled to the exhaust port for pumping the gases out of the substrate processing chamber during the processing and the cleaning; a substrate processing chamber further comprising:

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