Mounting of baffle for improving uniformity of bottom part purge gas flow

Abstract

To provide a processing chamber for improving a uniformity of an azimuthal angle of a pressure profile of a processing gas in a substrate processing device.SOLUTION: A processing chamber 100 contains: a chamber lid assembly 108 that defines a processing capacity 116; a side wall 104; and a substrate support body 111. A bottom bowl 166, a chamber base 106, and a side wall define a purge capacity 118. The purge capacity is positioned to a lower side of the processing capacity. The bottom bowl contains a first front surface 112 having a first equalizer hole penetrating therethrough. A passage 120 positioned onto the first equalizer hole is coupled to the purge capacity of the processing capacity via the first equalizer hole and an inlet port 121. The chamber base includes a purge port 144 so as to be coupled to a purge line 148 for supplying purge gas 119 to the purge capacity, and a baffle arranged in the purge capacity at a predetermined height onto the purge port makes a locus of the purge gas deviated, and makes the speed of a purge gas jet reduced.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] TECHNICAL FIELD The examples described herein relate generally to substrate processing apparatus, and more particularly to an apparatus for improving processing uniformity of substrates in a substrate processing apparatus. [Background technology]

[0002] Deposition processes, such as chemical vapor deposition (CVD) and plasma enhanced chemical vapor deposition (PECVD) processes, are commonly used in the manufacture of semiconductor devices. During the manufacture of semiconductor devices, materials are deposited in layers on a substrate surface by reacting one or more gaseous precursors in a processing volume of a processing chamber to form a layer of material on the substrate surface. The gaseous precursors can include one or both of gas phase precursors and vapor phase precursors.

[0003] Residual materials, such as gaseous precursors and their reaction by-products, can undesirably deposit material on one or more interior surfaces within the processing volume of the processing chamber. The thickness of the deposit can increase with every substrate processed. As the thickness of the deposit of residual material increases, the deposits eventually flake off the surfaces of the processing chamber, leading to undesirable particulate contamination within the processing volume. Particulate contamination can adversely affect the quality of the material layer deposited on the substrate. Thus, CVD and PECVD processing chambers must be periodically cleaned to remove residual materials therefrom. Cleaning the process chamber includes periodic cleaning cycles between substrate processing operations and / or opening the chamber for cleaning and routine maintenance. Such cleaning and maintenance results in reduced substrate throughput and increased chamber downtime. Thus, this cleaning and maintenance can result in lost production capacity of the processing chamber.

[0004] Therefore, there is a need in the art for an apparatus for preventing undesired deposition on interior surfaces of the processing volume of a processing chamber. Summary of the Invention

[0005] A baffle for a purge gas volume of a plasma processing chamber is disclosed herein. The processing chamber includes a lid, a sidewall, and a substrate support that collectively define a processing volume. A bottom bowl, a chamber base, and a wall coupled to the chamber base and the bottom bowl collectively define a purge volume. The purge volume is positioned below the processing volume. The bottom bowl includes a first surface having a first equalizer hole disposed therethrough. A passageway couples the processing volume to the purge volume via the first equalizer hole and an inlet. The passageway is positioned above the first equalizer hole. The chamber base has a purge port that is coupleable to a purge gas line for supplying purge gas to the purge volume via the purge port. A baffle is positioned within the purge volume at a height above the purge port. The baffle is configured to deflect a trajectory of purge gas entering the purge volume.

[0006] In another example, a processing chamber includes a lid, a sidewall, and a substrate support that collectively define a processing volume. A bottom bowl, a chamber base, and a wall coupled to the chamber base and the bottom bowl collectively define a purge volume. The purge volume is positioned below the processing volume. The bottom bowl includes a first surface having a first equalizer hole disposed therethrough. A passageway couples the processing volume to the purge volume via the first equalizer hole and the inlet. The passageway is positioned above the first equalizer hole. The chamber base has a first purge port that is coupleable to a first purge gas line for supplying purge gas to the purge volume via the purge port. The chamber base has a second purge port that is coupleable to a second purge gas line for supplying purge gas to the purge volume via the second purge port. A baffle is positioned within the purge volume at a height above the first purge port and the second purge port.

[0007] In yet another example, a processing chamber includes a lid, a sidewall, and a substrate support that collectively define a processing volume. A bottom bowl, a chamber base, and a wall coupled to the chamber base and the bottom bowl collectively define a purge volume. The purge volume is positioned below the processing volume. The bottom bowl includes a first surface having a first equalizer hole disposed therethrough. A passageway couples the processing volume to the purge volume via the first equalizer hole and an inlet. The passageway is positioned above the first equalizer hole. The chamber base has a purge port that is coupleable to a purge gas line for supplying purge gas to the purge volume via the purge port. A baffle is positioned within the purge volume at a height above the purge port. The baffle is configured to deflect a trajectory of purge gas entering the purge volume. The baffle is configured to reduce the velocity of the purge gas at the first equalizer hole to less than 20 percent of the velocity of the purge gas jet at the purge port.

[0008] In order that the above-mentioned features of the present disclosure may be understood in detail, a more detailed description of the present disclosure, briefly summarized above, may be obtained by referring to examples of the present specification, some of which are illustrated in the accompanying drawings. It should be noted, however, that the accompanying drawings are merely examples and therefore should not be considered as limiting the scope of the present disclosure. The accompanying drawings are therefore intended to admit other equally effective examples. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic cross-sectional view of an exemplary processing chamber 100, according to one example. [Diagram 2] FIG. 2 is a cross-sectional plan view of an example baffle disposed within the purge volume of the processing chamber of FIG. [Diagram 3] FIG. 2 is a cross-sectional plan view illustrating another example of a baffle disposed within the purge volume of the processing chamber of FIG. [Figure 4] FIG. 2 is a cross-sectional plan view illustrating yet another example of a baffle disposed within the purge volume of the processing chamber of FIG. [Diagram 5] FIG. 2 is a cross-sectional plan view illustrating yet another example of a baffle disposed within the purge volume of the processing chamber of FIG. [Figure 6] 2 is a cross-sectional plan view of an alternative configuration of the purge volume of the processing chamber 100 shown in FIG. [Figure 7] FIG. 2 is a schematic top plan view of the processing chamber of FIG. 1 showing the location of multiple purge lines and baffles; [Figure 8] Graph of mass flow uniformity shown across multiple equalizer holes [Figure 9] FIG. 2 is a cross-sectional plan view illustrating another example of a baffle disposed within the purge volume of the processing chamber of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] For ease of understanding, wherever possible, identical reference numerals are used to designate identical elements common to the figures, and it is contemplated that elements and features of one example may be beneficially incorporated in other examples without further recitation.

[0011] Examples disclosed herein generally relate to a flow deflector device that blocks a jet of purge gas in a purge gas volume. Advantageously, blocking the jet of purge gas affects the average mass flow rate of purge gas at the equalizer hole(s). The equalizer hole couples the purge gas volume to the process volume through a passage. The mass flow rate of purge gas at the equalizer hole corresponds to the mass flow rate of process gas entering the process volume at the inlet. In other words, the mass flow rate of purge gas in the purge gas volume is proportional to the mass flow rate at the inlet, i.e., the mass flow rate of purge gas at the region where the process volume couples to the purge gas volume. The velocity of the process gas at the inlet of the passage affects the azimuthal pressure profile and mass flow rate uniformity of the plasma across the substrate in the process volume. Similarly, the momentum of the process gas at the inlet of the passage affects the azimuthal pressure profile and mass flow rate uniformity of the plasma across the substrate in the process volume.

[0012] The uniformity of deposition on the substrate corresponds to the mass flow uniformity and pressure profile around the substrate. The uniformity of the flow and pressure profile correlates with the individual uniformity levels of the process gas and the mass flow uniformity of the purge gas(es). Advantageously, placing a baffle in the purge volume significantly improves the uniformity of the mass flow of the purge gas when it interacts with the process gas at the inlet that connects the purge volume to the process volume. Thus, a highly uniform pressure and flow profile is provided around the substrate. Increasing the uniformity of the flow rate in the purge volume thus reduces unwanted deposition of material on the inner walls of the process chamber, thereby reducing the frequency of cleaning of the process chamber and reducing downtime of the process chamber.

[0013] The examples herein are illustratively described below with respect to use in a system configured to etch a substrate. However, it should be noted that the disclosed subject matter is useful in other system configurations, such as chemical vapor deposition systems, physical vapor deposition systems, and other systems in which a purge gas is introduced into the interior volume of a plasma processing chamber. It should also be understood that the examples disclosed herein can be adapted for implementation in other process chambers configured to process substrates of various dimensions.

[0014] 1 is a schematic cross-sectional view of an exemplary processing chamber 100, according to one example. The processing chamber 100 includes a chamber body 102 having one or more sidewalls 104, a chamber base 106, and a chamber lid assembly 108. An interior volume 103 is defined by the chamber body 102, the sidewalls 104, the chamber base 106, and the chamber lid assembly 108. A substrate support 111 is disposed within the interior volume 103. The interior volume 103 includes a processing volume 116 and a purge volume 118. The processing volume 116 is defined by an inner surface of the sidewalls 104, an inner surface of the chamber lid assembly 108, and a first surface 112 of the substrate support 111. The purge volume 118 is defined by the sidewalls 104, the chamber base 106, the bellows 130, and a bottom bowl 166.

[0015] Herein, the chamber lid assembly 108 is electrically isolated from the sidewall 104. The showerhead 109 is disposed within and coupled to the chamber lid assembly 108. The showerhead 109 has a plurality of openings 110 disposed therethrough. The plurality of openings 110 uniformly distribute one or more process gases 117 from a process gas source 150 into the process volume 116. Herein, the showerhead 109 is formed of a conductive material. The showerhead 109 is also coupled to a first power source 132, such as an RF power source. The first power source 132 provides power to ignite and maintain a plasma of the process gases through capacitive coupling therewith.

[0016] The substrate support 111 is positioned within the interior volume 103. The support shaft 126 is coupled to a lift actuator 128 that raises and lowers the support shaft 126. The substrate support 111 is coupled to the support shaft 126. The lift actuator 128 is configured to move the substrate support 111 between a lowered position and a raised position. The raised or lowered position may facilitate transfer of the substrate 114 into and out of the interior volume 103. The height of the substrate support 111 is determined in relation to the vertical position of the support shaft 126.

[0017] Bellows 130 also surrounds support shaft 126. Bellows 130 may also be coupled to lift actuator 128 to provide a flexible seal therebetween. Bellows 130 maintains the vacuum integrity of interior volume 103.

[0018] The substrate support 111 is also positioned partially within the process volume 116. The substrate support 111 is positioned above the purge volume 118. The substrate support 111 includes a first surface 112 facing the chamber lid assembly 108 for receiving the substrate 114. A second surface 113 is opposite the first surface 112 and faces the chamber base 106. During substrate processing, the substrate 114 is secured to the first surface 112 of the substrate support 111 by an electrostatic chuck (ESC). The substrate support 111 may include one or more heaters. The substrate support 111 may also include one or more cooling channels (not shown). The substrate support 111 allows for control of the temperature of the substrate 114 disposed thereon.

[0019] During substrate processing, process gas 117 is provided to the interior volume 103 by the showerhead 109. The process gas 117 is also drawn radially outward into the process volume 116 from a region above the center of a substrate 114 disposed on the substrate support 111. The process gas 117 may be drawn downward over a circumferential edge of a first surface 112 of the substrate support 111. In such a case, the process gas 117 is drawn through a first inlet 121 of a first passage 120 into the exhaust liner assembly 134.

[0020] The exhaust liner assembly 134 is disposed in the internal volume 103. The exhaust liner assembly 134 may include a circumferential C-channel shaped section. The exhaust liner assembly 134 is configured to reduce deposition of undesired residual materials on the inner walls of the chamber body 102. The exhaust liner assembly 134 facilitates removal of the process gas 117 from the process volume 116. The exhaust liner assembly 134 helps prevent the process gas 117 in the process volume 116 from flowing into the purge volume 118. The exhaust liner assembly 134 also prevents the purge gas 119 from flowing from the purge volume 118 into the process volume 116. The exhaust liner assembly 134 is also configured to reduce deposition of residual materials on surfaces of chamber components disposed in the purge volume 118.

[0021] The exhaust liner assembly 134 includes a liner 136. The liner 136 has an interior space 138. As used herein, the liner 136 may be made from a ceramic material, such as aluminum oxide. The liner 136 may also be made from NF 3 The liner 136 may be made from other materials that are suitably resistant to heat and corrosion from halogen-containing cleaning plasmas, such as halogen-based plasmas. The liner 136 can be removed from the processing chamber 100 for periodic cleaning or replacement.

[0022] The purge gas 119 is supplied by a purge gas source 146 in fluid communication with the purge port 144. A purge line 148 couples the purge gas source 146 to the purge port 144. As used herein, the purge gas 119 can be supplied to the purge volume 118 during substrate processing or during a chamber cleaning operation. The purge gas 119 flows through the purge port 144 into the purge volume 118. The purge port 144 is disposed through the chamber base 106. The purge port 144 can have a symmetrical cross-sectional shape, such as a circular cross-sectional shape. In other examples, the purge port 144 can have an asymmetrical cross-sectional shape.

[0023] A purge gas source 146 provides a purge gas 119 within the purge volume 118. The purge gas 119 is also drawn into the interior space 138 of the liner 136 through an exhaust conduit 123 that is fluidly coupled to the first passageway 120. The interior space 138 is coupled to an exhaust channel 140. The exhaust channel 140 is coupled to an exhaust port 142. Both the process gas 117 and the purge gas 119 are then drawn from the interior space 138 of the liner 136 through the exhaust channel 140 and exhausted through the exhaust port 142.

[0024] 2 is a cross-sectional plan view of an example baffle 200 disposed within the purge volume 118 of the processing chamber 100 of FIG. 1. The purge volume 118 is defined by a bellows 130, a chamber base 106, a bottom bowl 204, and a sidewall 104. The bellows 130 is coupled to the chamber base 106. The bellows 130 is also coupled to the bottom bowl 204. A purge port 208 is disposed in the chamber base 106. A purge gas source 146 supplies a purge gas 119 to the purge volume 118 through the purge port 208. A purge line 148 couples the purge gas source 146 to the purge volume 118 through the purge port 208.

[0025] The baffle 200 is positioned above the purge port 208. The baffle 200 can be made of ceramic, metal, or any other material suitable for an inert gas environment that can be securely attached to the inner surface 248 of the purge volume 118. For example, the baffle 200 can be made of an aluminum-containing material, such as aluminum nitride. The baffle 200 can have any geometric shape. A non-limiting example of one geometric shape for the baffle 200 is a quadrilateral shape with a length of 30 mm, a width of 28 mm, and a thickness of 5 mm. The baffle 200 is positioned at a height 228 above the purge port 208. The height 228 of the baffle 200 can be 5 mm to 13 mm above the purge port 208. However, these dimensions can be smaller or larger, as long as the baffle 200 is configured to modify the trajectory 244 of the jet 212 of the purge gas 119. A vertical distance 240 between the bottom bowl 204 and a bottom surface 232 of the baffle 200 may vary as the bottom bowl 204 moves vertically. The height 228 and vertical distance 240 are substantially similar to a vertical length 250 between the purge port 208 and the equalizer hole(s) 216. The bottom surface 232 of the baffle 200 is substantially parallel to an inner surface 248 of the chamber base 106.

[0026] An equalizer hole 216 is disposed in the bottom bowl 204. The equalizer hole 216 couples the purge volume 118 to the first passage 120. Although a single equalizer hole 216 is shown, a series of equalizer holes 216 are disposed radially along the bottom bowl 204. The series of equalizer holes 216 are positioned equidistantly along the bottom bowl 204. As the purge gas 119 enters the purge volume 118, a jet 212 of the purge gas 119 is generated at the purge port 208. The velocity of the jet 212 of the purge gas 119 at the purge port 208 can exceed 50 m / sec. The baffle 200 restricts the flow of the jet 212 of the purge gas 119 moving into the purge volume 118. The velocity of the jet 212 is significantly reduced near the top of the purge port 208 by the baffle 200.

[0027] Thus, the velocity of the purge gas 119 is dissipated by the time it enters the equalizer holes 216 in the bottom bowl 204. Therefore, the velocity and energy of the purge gas 119 in the area near the equalizer holes 216 is substantially less than the velocity and energy of the purge gas 119 at the purge port 208. Dissipation of energy occurs when the ability of a fluid with its initial form and initial energy to perform mechanical work is less than the ability of the fluid in its final form to perform mechanical work. The jet 212 contacts the bottom surface 232 of the baffle 200. The trajectory 244 of the jet 212 is modified by the baffle 200. The momentum of the jet 212 is reduced when the purge gas 119 contacts the baffle 200, which modifies the trajectory 244 of the jet 212. Correspondingly, the kinetic energy of the purge gas 119 is also reduced. The velocity of the purge gas 119 also decreases because the momentum of the purge gas 119 decreases when the gas contacts the baffle 200. In such a case, the purge gas 119 has less momentum as it passes through the first passage 120.

[0028] 1 and 2, when the purge gas 119 traveling through the first passage 120 reaches the first inlet 121, the purge gas 119 creates a back pressure with the process gas 117 in the process volume 116. Thus, the process gas 117 is pressurized in the process volume 116. Thus, the pressure of the purge gas 119 at the first inlet 121 affects the azimuthal pressure profile of the process gas 117 across the substrate 114. Thus, the azimuthal uniformity of the pressure profile of the process gas 117 is improved by the baffle 200.

[0029] Advantageously, when the baffle 200 is positioned over the purge port 208, the velocity of the purge gas 219 at the equalizer holes 216 is reduced. In this manner, the purge gas 119 in the first passage 120 is thus prevented from entering the process volume 116. The reduced velocity of the purge gas 119 can therefore be used to control the azimuthal plasma profile of the process gas 117 across the substrate 114. When the baffle 200 is positioned to reduce the velocity jet 212 at the purge port 208, the azimuthal uniformity of the pressure profile of the process gas 117 over the substrate 114 is significantly improved within the process volume 116.

[0030] 3 is a cross-sectional plan view illustrating yet another example of a baffle 300 disposed within the purge volume 118 of the processing chamber 100 of FIG. 1. The baffle 300 may be supported by legs 304. The legs 304 may extend from a bottom surface 312 of the baffle 300 to the chamber base 106. The legs 304 may be configured to prevent rotation of the baffle 300 or a portion thereof. A plurality of fasteners 302 are configured to secure the baffle 300 within the purge volume 118 at a predetermined height 228. The fasteners 302 may be bolts, pins, welded rods, or any other suitable connection device. The fasteners 302 may pass through a top surface 308 of the baffle 300. Alternatively, the fasteners 302 may be attached to or threaded into the baffle 300. The fasteners 302 are secured to an inner surface 248 of the chamber base 106. For example, the fasteners 302 may be attached to the chamber base 106 by welding, screwing, pinning, or other suitable techniques. Securing the baffle 300 within the purge volume 118 prevents the baffle 300 from becoming dislodged from the chamber base 106. Securing the baffle 300 also helps prevent undesired rotation or tilting of the baffle 300 due to the force of the purge gas jets 212.

[0031] The baffle 300 is positioned over the purge port 208 such that a length 324 of the baffle 300 is bisected by a centerline 328 of the purge port 208. The first width 316 and the second width 320 together may be substantially equal to the length 324 of the baffle 300. Thus, the first width 316 of the baffle 300 is substantially the same as the second width 320 of the baffle 300. The lower surface 312 of the baffle 300 is substantially parallel to the inner surface 248 of the chamber base 106.

[0032] The vertical distance 332 between the equalizer holes 216 and the lower surface 312 of the baffle 300 changes as the position of the bottom bowl 204 moves vertically when the substrate support 111 is raised or lowered by the lift actuator 128 (shown in FIG. 1 ). In this example, the lower surface 312 of the baffle 300 is positioned below the equalizer holes 216 at a vertical distance 332. The vertical distance 332 can be between 5 mm and 13 mm.

[0033] 4 is a cross-sectional plan view of yet another example of a baffle 400 disposed within the purge volume 118 of the processing chamber 100 of FIG. 1. The baffle 400 is also supported by legs 304. The baffle 400 may also be secured to the chamber base 106 by a number of fasteners 302. The baffle 400 discussed herein may have substantially similar dimensions as the baffle discussed above with respect to baffle 300. The baffle 400 has a first width 404 and a second width 408. The first width 404 and the second width 408 together may be substantially equal to the length 420 of the baffle 400. The first width 404 and the second width 408 are different widths, i.e., unequal in at least one dimension. In this example, the length 420 of the baffle 400 is not bisected by the centerline 328 of the purge port 208. Baffle 400, similar to baffle 200 above, is positioned at a height 228 above purge port 208.

[0034] A vertical distance 416 between the equalizer holes 216 and the lower surface 412 of the baffle 400 may vary as the substrate support 111 (shown in FIG. 1 ) moves vertically with the raising and lowering of the substrate support 111. The lower surface 412 of the baffle 400 is positioned at a vertical distance 416 above the equalizer holes 216. The vertical distance 416 may be between 5 mm and 13 mm. The lower surface 412 of the baffle 400 is substantially parallel to the inner surface 248 of the chamber base 106.

[0035] Advantageously, the baffle 400 has an increased surface area, which can further reduce the momentum of the jet 212. The reduction in momentum or velocity of the jet 212 improves the azimuthal pressure profile of the plasma across a substrate in the process volume 116 (shown in FIG. 1 ).

[0036] FIG. 5 is a cross-sectional plan view illustrating yet another example of a baffle 500 disposed within the purge volume 118 of the processing chamber 100 of FIG. 1. In this example, the baffle 500 is attached to a portion of the bellows 130. The bottom surface 512 of the baffle 500 is substantially parallel to the inner surface 248 of the chamber base 106. The baffle 500 can be attached to the portion of the bellows 130 using fasteners 302 or legs 304, or a combination of both (not shown in FIG. 5). The baffle 500 can be attached to the bellows using any suitable arrangement that ensures that the baffle 500 remains substantially parallel to the inner surface 248 of the chamber base 106. In this example, the baffle 500 can move vertically in a manner that changes the height 504 of the bottom surface 512 relative to the inner surface 248 of the chamber base 106 as the substrate support 111 (shown in FIG. 1) moves up and down. As the bottom bowl 204 moves vertically, the bellows 130 also moves. Thus, the baffle 500 attached to the bellows 130 also moves. Thus, the vertical distance 508 between the bottom surface 512 of the baffle 500 and the equalizer holes 216 changes with the movement of the substrate support 111. Stated another way, the height 504 of the baffle 500 is configured to change based on the height of the substrate support 111. As discussed above, changing the height 504 or vertical distance 508 affects the average mass flow rate of the purge gas 119 near the equalizer holes 216 by reducing the velocity and changing the direction that the purge gas enters the purge volume 118.

[0037] FIG. 6 is a cross-sectional plan view of another configuration of the purge volume 118 of the processing chamber 100 shown in FIG. 1. The baffle 600 shown in FIG. 6 includes a first leg 604 and a second leg 608. The second leg 608 is coupled to the first leg 604. For example, the first leg 604 can be welded, screwed, bolted, brazed, or glued to the second leg 608. The first leg 604 and the second leg 608 can also be uniformly manufactured from a single block of material. The surface of the first leg 604 is substantially parallel to the first inner surface 624. For example, the first inner surface 624 is parallel to a surface of the purge volume 118, such as the inner surface 248 of the chamber base 106. The second leg 608 is substantially parallel to the sidewall 616 of the chamber base 106. An angle 620 is formed between the first leg 604 and the second leg 608. In this example, the angle 620 can range between about 60 degrees and about 120 degrees, such as about 90 degrees.

[0038] The baffle 600 may be attached to the second inner surface 628. For example, the baffle 600 may be attached to a sidewall of the purge volume 118, such as the chamber base 106. The baffle 600 is attached to the chamber base 106 using any suitable arrangement that ensures that the first leg 604 remains substantially parallel to the first inner surface 624 of the chamber base 106. In this example, the baffle 600 is also attached using any suitable arrangement that ensures that the second leg 608 remains substantially parallel to the second inner surface 628 of the chamber base 106.

[0039] The baffle 600 is positioned within the purge volume 118 such that there is a gap 632 between the first inner surface 624 of the chamber base 106 and a portion of the baffle 600. The purge line 612 supplies the purge gas 119 to the purge volume 118 via a purge port 636. A jet 212 of the purge gas 119 enters the purge volume 118 through the purge port 636 in the sidewall 616 of the chamber base 106. Stated another way, the purge gas enters from the purge port 636 in the side of the purge volume 118 perpendicularly from the first inner surface 624 in the bottom of the purge volume 118. The trajectory 244 of the purge gas 119 is altered by contact with the baffle 600. Thus, the average mass flow rate of the purge gas 119 at the equalizer holes 216 is reduced relative to the mass flow rate of the jet 212 at the purge port 636.

[0040] 7 is a schematic top plan view illustrating a plurality of purge lines 714 and a baffle position 700 of the processing chamber 100 of FIG. 1. The baffle position 700 includes a plurality of baffles 732. Each baffle 732 is disposed adjacent to a purge port 712. Thus, there may be more than one purge port 712, and each purge port 712 is connected to a purge line 714. Each baffle 732 is configured to disrupt the jet 212 of purge gas 119 as it enters the purge volume 118. Each baffle 732 is positioned at the same distance 716 from the central axis 704 of the internal volume 103. The angle 728 between one baffle 732 and an adjacent baffle 732 may be the same angle. The angle 728 may also be different. In the example shown, there are four baffle positions, and each baffle position 700 has a baffle 732. In the example shown, the angle 728 between each baffle 732 is about 90 degrees. In another non-limiting example, the angle between each baffle position 700 can be any angle between about 60 degrees and about 180 degrees, and there are multiple baffles 732. In a similar manner to the other examples, the baffles 732 can be made of a metal or ceramic material.

[0041] Additionally, an alternative circular baffle 800, represented by dashed lines, is shown in FIG. 7. Circular baffle 800 may be utilized in place of baffle 732. In this example, circular baffle 800 has a continuous section 808 that extends through purge volume 118. Continuous section 808 has an annular or toroidal shape. Continuous section 808 is disposed within purge volume 118 adjacent each purge port 712.

[0042] Although baffle 732 and circular baffle 800 are shown in the same figure, baffle 732 and circular baffle 800 are not disposed in purge volume 118 at the same time. Circular baffle 800 may have a width 804 between about 5 mm and about 13 mm. Circular baffle 800 may have a thickness of about 5 mm, consistent with baffles 200, 300, 400, 500 described above. Similar to the description of baffle 300 in FIG. 3, circular baffle 800 may be supported on legs 304, secured to the bottom surface of chamber base 106 with fasteners 302, or a combination of both.

[0043] The cross-sectional shape of the circular baffle 800 is taken along line AA in FIG. 7. The circular baffle 800 can have the same cross-sectional shape as the baffle 300 or the baffle 400. As discussed with respect to the baffle 500 shown in FIG. 5, the circular baffle 800 can be attached to the bellows 130 in an alternating manner. The circular baffle 800 can have the same cross-sectional shape as the baffle 500. As shown in FIG. 6, the circular baffle 800 can also be attached to the second inner surface 628 of the chamber base 106. The circular baffle 800 can have the same cross-sectional shape as the baffle 600. The circular baffle 800 can have a first leg 604 and a second leg 608 that support the circular baffle 800. In a manner similar to the other examples, the circular baffle 800 can be made of a metal or ceramic material.

[0044] 8 is a graph of mass flow uniformity shown across multiple equalizer holes. The average mass flow across each equalizer hole 216 was observed. In the example shown herein, there are over 70 equalizer holes 216. In this example, the variable x shown in the identifiers along the x-axis is a multiplier of the number of holes in the graph and can be greater than 4 and less than 10. For example, if x=4, then the identifiers on the x-axis would be 4, 8, 12, 16, etc.

[0045] In conventional systems where no baffle 200 is located in the purge volume 118, the average mass flow rate at an equalizer hole 216 deviates by as much as ±3% relative to the average mass flow rate taken at other equalizer holes 216. For example, an equalizer hole 999 located between positions 8x and 10x, which has a standard deviation of about -3%, would be located closest to the purge port 208 if the baffle 200 was not present. Because a given equalizer hole 216 is located radially away from the purge port 208, the standard deviation of the mass flow rate varies widely. For an equalizer hole 998 that is not near the purge port 208 (e.g., between positions x and 4x), the mass flow rate may deviate by as much as ±2%. This variation in mass flow rate at the multiple equalizer holes 216 affects the momentum of the purge gas 119 at the first inlet 121 of the process volume 116. Variations in mass flow rate affect the momentum and therefore the velocity of the purge gas 119 as it enters the process volume 116. The resulting velocity variations at the first inlet 121 further perturb the azimuthal uniformity of the pressure profile of the process gas 117 over the substrate 114.

[0046] Advantageously, when a baffle such as baffle 200 is positioned over purge port 208, the standard deviation of the mass flow rate across each of equalizer holes 216 is significantly reduced. When baffle 200 is located in purge volume 118, the standard deviation of the mass flow rate across each of the plurality of equalizer holes 816 is less than ±1%. Thus, the first average mass flow rate of purge gas at the first equalizer hole is within one standard deviation of the average mass flow rate at the second equalizer hole, the first equalizer hole being directly adjacent to the second equalizer hole. This is an improvement over conventional systems, with the standard deviation of the mass flow rate being reduced by approximately 60%. The reduced average mass flow rate at equalizer holes 216 substantially reduces the purge gas 119 entering process volume 116 compared to conventional systems in which no baffle is present. Thus, the reduction in the velocity of the purge gas 119 entering the first passageway 120 contributes to the azimuthal uniformity of the pressure profile of the process gas 117 over the substrate 114 .

[0047] FIG. 9 is a cross-sectional plan view illustrating another example of a baffle disposed in the purge volume 118 of the processing chamber 100 of FIG. 1. The baffle 900 may be supported by legs 304. The legs 304 extend from a bottom surface 920 of the baffle 900 to an inner surface 916 of the bottom bowl 204. The legs 304 may be configured to prevent rotation of the baffle 900, or a portion thereof. A plurality of fasteners 302 (shown in FIG. 3) are configured to secure the baffle 900 in the purge volume 118 at a height 912 above the inner surface 248 of the chamber base 106. The baffle 900 is also positioned at substantially the same height 912 above the purge port 208. The height 912 between the inner surface 248 of the chamber base 106 and the upper surface 904 of the baffle 900 may change as the position of the bottom bowl 204 moves vertically when the substrate support 111 is raised or lowered by the lift actuator 128 (shown in FIG. 1). The legs 304 may be secured with fasteners 302, which may be bolts, pins, welded rods, or any other suitable connection device. The fasteners 302 may pass through a top surface 904 of the baffle 900. Alternatively, the fasteners 302 may be attached to a bottom surface 920 of the baffle 900 or threaded into the baffle 900. The fasteners 302 are secured to an inner surface 916 of the bottom bowl 204. As with the examples discussed above, the fasteners 302 may be attached to the bottom bowl 204 by welding, screwing, pinning, or other suitable techniques.

[0048] The vertical distance 908 between the equalizer holes 216 and the top surface 904 of the baffle 900 does not change as the bottom bowl 204 moves vertically. The top surface 904 of the baffle 900 is positioned a vertical distance 908 below the equalizer holes 216. The vertical distance 908 can be adjusted such that the height 912 is between about 5 mm and about 13 mm. The top surface 904 of the baffle 900 is substantially parallel to the inner surface 248 of the chamber base 106.

[0049] While the above is directed to particular examples, other examples can be devised without departing from the basic scope thereof, which scope is determined by the claims that follow.

Claims

1. A processing chamber comprising: a lid, a sidewall, and a substrate support that collectively define a processing volume; a bottom bowl, a chamber base, and walls coupled to the chamber base and bottom bowl, collectively defining a purge volume, the purge volume being positioned below the process volume, the bottom bowl including a first surface having a first equalizer hole disposed therethrough, a passageway coupling the process volume to the purge volume via the first equalizer hole and an inlet, and the passageway being positioned above the first equalizer hole, the chamber base having a purge port coupleable to a purge gas line for supplying a purge gas to the purge volume via the purge port; and a baffle disposed within the purge volume at a height above the purge port, the baffle configured to deflect a trajectory of the purge gas entering the purge volume. a processing chamber comprising:

2. 10. The processing chamber of claim 1, wherein the baffle is disposed above the purge port at a height equal to between 1 and 3 times a thickness of the baffle.

3. 3. The processing chamber of claim 2, wherein the baffle is configured to reduce the velocity of the purge gas at the first equalizer hole to between less than 10 percent and less than 20 percent of the velocity of the purge gas at the purge port.

4. The processing chamber of claim 1 , wherein the baffle height is configured to vary based on the height of the substrate support.

5. 2. The processing chamber of claim 1, wherein the baffle is positioned such that a horizontal position of the baffle is substantially bisected in width by a vertical line extending from a center of the purge port, the width being bisected by the vertical line into two sides of approximately equal length.

6. 2. The processing chamber of claim 1, wherein the baffle is positioned such that a horizontal position of the baffle is disposed such that a width of the baffle is divided by a vertical line extending from a center of the purge port, the width being divided by the vertical line into two sides having different lengths.

7. The baffle is a first leg positioned substantially parallel to a direction of the purge gas jet; a second leg positioned orthogonal to the first leg, the second leg configured to reduce the velocity of the purge gas jet; The processing chamber of claim 1 , comprising:

8. 2. The processing chamber of claim 1, wherein a first average mass flow rate of the purge gas at the first equalizer holes is within one standard deviation of a second average mass flow rate at a second equalizer hole disposed in the bottom bowl, the first equalizer hole being immediately adjacent to the second equalizer hole.

9. a third average mass flow rate of the purge gas through a third equalizer hole disposed in the bottom bowl is within one standard deviation of the second average mass flow rate through the second equalizer hole and is within one standard deviation of the first average mass flow rate through the first equalizer hole, the first equalizer hole being directly adjacent to the second equalizer hole, and the second equalizer hole being directly adjacent to the third equalizer hole.

9. The processing chamber of claim 8.

10. A processing chamber comprising: a lid, a sidewall, and a substrate support that collectively define a processing volume; a bottom bowl, a chamber base, and a wall coupled to the chamber base and the bottom bowl, collectively defining a purge volume, the purge volume being positioned below the process volume, the bottom bowl including a first surface having a first equalizer hole disposed therethrough; where a passageway couples the process volume to the purge volume through the first equalizer hole and an inlet, and the passageway is positioned above the first equalizer hole, the chamber base has a first purge port connectable to a first purge gas line for supplying a purge gas to the purge volume through the first purge port, and the chamber base has a second purge port connectable to a second purge gas line for supplying the purge gas to the purge volume through the second purge port; a baffle disposed within the purge volume at a height above the first purge port and the second purge port. The processing chamber further comprises:

11. 11. The processing chamber of claim 10, wherein the baffle is disposed above the first purge port or the second purge port at a height equal to between 1 and 3 times a thickness of the baffle.

12. 12. The processing chamber of claim 11, wherein the baffle is configured to reduce a velocity of the purge gas at the first equalizer hole to between less than 10 percent and less than 20 percent of a velocity of the purge gas at the first purge port or the second purge port.

13. The processing chamber of claim 10 , wherein the baffle height is configured to vary based on the height of the substrate support configured to support a substrate.

14. 11. The processing chamber of claim 10, wherein the baffle comprises a plurality of sections, each section of the plurality of sections being positioned over one of the first purge port or the second purge port, and each section being further positioned equidistant from a central axis of the processing volume.

15. 11. The processing chamber of claim 10, wherein the baffle includes a continuous section, the continuous section disposed above the first purge port and the second purge port, the continuous section disposed equidistant from a central axis of the processing volume.

16. The baffle is a first leg positioned substantially parallel to a direction of the purge gas jet; a second leg positioned orthogonal to the first leg, the second leg configured to reduce the velocity of the purge gas jet; The processing chamber of claim 10 .

17. 11. The processing chamber of claim 10, wherein the baffle is configured to reduce a velocity of the purge gas at the first equalizer hole to less than 20 percent of a velocity of a purge gas jet at the first purge port or the second purge port.

18. 11. The processing chamber of claim 10, wherein a first average mass flow rate of the purge gas at the first equalizer holes is within one standard deviation of a second average mass flow rate at a second equalizer hole disposed in the bottom bowl, the first equalizer hole being immediately adjacent to the second equalizer hole.

19. 20. The processing chamber of claim 18, wherein a third average mass flow rate of the purge gas at a third equalizer hole disposed in the bottom bowl is within one standard deviation of the second average mass flow rate at the second equalizer hole and is within one standard deviation of the first average mass flow rate at the first equalizer hole, the first equalizer hole being directly adjacent to the second equalizer hole, and the second equalizer hole being directly adjacent to the third equalizer hole.

20. A processing chamber comprising: a lid, a sidewall, and a substrate support that collectively define a processing volume; a bottom bowl, a chamber base, and a wall coupled to the chamber base and the bottom bowl, collectively defining a purge volume, the purge volume being positioned below the process volume; where the bottom bowl includes a first surface having a first equalizer hole disposed therethrough, a passageway connecting the process volume to the purge volume via the first equalizer hole and an inlet, the passageway being positioned above the first equalizer hole, the chamber base having a purge port connectable to a purge gas line for supplying a purge gas to the purge volume via the purge port; a baffle disposed within the purge volume at a height above the purge port, the baffle configured to deflect a trajectory of the purge gas entering the purge volume and configured to reduce a velocity of the purge gas at the first equalizer hole to less than 20 percent of a velocity of a purge gas jet at the purge port. The processing chamber further comprises:

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