Detachable showerhead faceplate for semiconductor processing tools

Abstract

A showerhead for semiconductor processing operations is disclosed having a removable faceplate and various features that provide additional advantages in the context of a removable faceplate.

Description

[Background technology]

[0001] Related Applications A PCT Request Form is being filed contemporaneously herewith as part of this application. Each application to which this application claims benefit or priority as identified in the contemporaneously filed PCT Request Form is incorporated herein by reference in its entirety for all purposes.

[0002] Semiconductor processing tools commonly use a "showerhead" to distribute semiconductor process gases across a substrate or wafer supported in a semiconductor processing chamber by a pedestal or chuck. Showerheads typically feature multiple gas distribution ports distributed across the underside of the showerhead, through which process gases flow during semiconductor processing operations. Two common types of showerheads are used in semiconductor processing tools: "chandelier-type" showerheads and "recessed-type" showerheads. Chandelier-type showerheads typically include a disk-shaped structure housing the gas distribution ports, one or more internal plenums for distributing process gases to the gas distribution ports, and a stem that connects to or extends from the top of the disk-shaped structure to or through the ceiling of the processing chamber in which the chandelier-type showerhead is located. The stem functions to support the disk-shaped structure within the processing chamber and to deliver process gases to the plenums within the disk-shaped structure. A recessed showerhead does not have a stem or equivalent structure, but instead simply attaches to the wall of the semiconductor processing chamber and often essentially functions as a lid for the semiconductor processing chamber.

[0003] A detachable faceplate design for a semiconductor processing showerhead is presented herein. Summary of the Invention

[0004] The details of one or more embodiments of the subject matter described herein are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages will become apparent from the description, drawings, and claims.

[0005] The present inventors have devised a semiconductor processing showerhead featuring a detachable showerhead faceplate. A typical semiconductor processing showerhead deteriorates over time due to exposure to the harsh environment found within the semiconductor processing chamber in which it is installed. Such deterioration can, in some cases, be remedied with a cleaning process; for example, showerheads used in deposition environments can suffer from deterioration in the form of deposition on the surface of the showerhead, which can cause narrowing of the gas distribution ports or changes in the profile of the underside of the showerhead facing the wafer, which can affect wafer processing uniformity. In such cases, the problematic showerhead can be removed and cleaned / repaired to remove such undesired deposits, and then reinstalled in the semiconductor processing tool (or another similar tool). However, in other cases, deterioration can be due to corrosion of the faceplate (e.g., as may be experienced in an etching process). In such cases, the showerhead may simply need to be removed and replaced.

[0006] In either case, replacement typically requires removing the entire showerhead from the processing chamber in which it is housed, a time-consuming process during which the chamber is unavailable for revenue-generating operations. Furthermore, such replacement can be extremely costly; a new showerhead is a high-cost component, and even if the showerhead is simply refurbished or cleaned, such refurbishment or cleaning can also be quite costly. To reduce equipment downtime and the cost of operating semiconductor processing equipment with a showerhead, the inventors have devised an easily installable detachable showerhead faceplate that can be configured to provide good thermal performance, resistance to deflection, and / or low gas leakage rates at the interface between the detachable showerhead faceplate and the portion of the showerhead to which it is attached.

[0007] In particular, the inventors conceived the showerhead faceplates discussed herein while designing showerheads for use in relatively high operating temperatures (e.g., in the range of 250° C. to 350° C.). Thus, various features described below may provide particular utility for showerheads used in high temperature environments, but may also be useful for showerheads in higher or lower temperature extremes.

[0008] In some embodiments, an apparatus can be provided that includes or is a showerhead faceplate. The showerhead faceplate can be configured to removably engage with a showerhead backplate and can have a plate region with a plurality of gas distribution ports disposed therein. Each gas distribution port can extend through the showerhead faceplate, and the showerhead faceplate can include one or more first planar thermal contact surfaces, each configured to contact a corresponding second planar thermal contact surface on the showerhead backplate when the showerhead faceplate is engaged with the showerhead backplate. The one or more first flat thermal contact surfaces may comprise an annular flat thermal contact surface having an outer diameter between 30.5 cm and 45.7 cm (12 inches and 18 inches) and surrounding the plate area when viewed along a first axis perpendicular to the annular flat thermal contact surface, the annular flat thermal contact surface having a flatness of not more than a value between 20.3 μm and 30.5 μm (800 μin and 1200 μin) and a surface roughness Ra of not more than a value between 0.61 μm and 1.02 μm (24 μin and 40 μin).

[0009] In some embodiments, the device may further include a plurality of posts disposed within and extending from the plate region, and the one or more first flat thermal contact surfaces may include, for each of the posts, an end post thermal contact surface parallel to the annular flat thermal contact surface.

[0010] In some such embodiments, the first flat thermal contact surface may have a flatness of 25.4 μm (1000 μin) or less and an average surface roughness Ra of 0.61 μm (24 μin) or more. In some other such embodiments, the first flat thermal contact surface may have a flatness of 25.4 μm (1000 μin) or less and an average surface roughness Ra of 0.76 μm (30 μin) or more, and in still other such embodiments, the first flat thermal contact surface may have a flatness of 25.4 μm (1000 μin) or less and an average surface roughness Ra of 1.02 μm (40 μin) or more.

[0011] In some embodiments of the device, the showerhead faceplate may be formed from an aluminum alloy.

[0012] In some embodiments of the apparatus, the showerhead faceplate may include a plurality of first screw holes distributed about the plate area and arranged within the annular flat thermal contact surface, and in some such embodiments, the first screw holes may be arranged in a circular array with an angular spacing of 20° or less between adjacent first screw holes.

[0013] In some embodiments of the apparatus, the showerhead faceplate may further include a first thermal interference fit feature configured to mate with a second thermal interference fit feature on the showerhead backplate when the showerhead faceplate is engaged with the showerhead backplate, the first thermal interference fit feature may include a radially outwardly facing first axisymmetric surface disposed between the plate region and the first screw hole, the first axisymmetric surface may have a first cross-sectional profile dimensioned to be within 0.01" to 0.014" of a corresponding second cross-sectional profile of the second thermal interference fit feature on the showerhead backplate when the showerhead faceplate is engaged with the showerhead backplate so that the showerhead faceplate is centered with respect to the showerhead backplate and when both the showerhead faceplate and the showerhead backplate are at 20°C.

[0014] In some such embodiments of the device, the first thermal interference fit feature can be a first cylindrical surface having a first diameter, and a second thermal interference fit feature on the showerhead backplate that the first thermal interference fit feature is configured to mate with when the showerhead faceplate is attached to the showerhead backplate can be a second cylindrical surface having a second diameter, and the first diameter can be smaller than the second diameter and within 0.02" of the second diameter when the showerhead faceplate and the showerhead backplate are both at 20°C.

[0015] In some further such embodiments of the apparatus, the showerhead faceplate may include an inner wall extending around the plate area and sandwiched between the first screw hole and the plate area, the inner wall may extend from the annular flat thermal contact surface, and the first thermal interference fit feature may be provided by an outwardly facing surface of the inner wall.

[0016] In some embodiments of the apparatus, the apparatus may further include a plurality of first threaded fasteners, the number of first threaded holes being equal to the number of first threaded holes, a plurality of washers, the number of first threaded holes being at least equal to the number of first threaded holes, and a plurality of Belleville washers, the number of first threaded holes being at least equal to the number of first threaded holes. In such embodiments, the apparatus may be a kit configured to facilitate replacement of an expired showerhead faceplate attached to a showerhead backplate of a semiconductor processing tool.

[0017] In some such embodiments, the showerhead faceplate can be formed of a first material, the first threaded fastener can be formed of a second material, the Belleville washer can be formed of a first alloy, and the washer can be formed of a second alloy. The first and second materials can each be an aluminum alloy, a 6061-T6 aluminum alloy, or alumina, and the first and second alloys can each be a nickel alloy, an aluminum alloy, or a 6061-T6 aluminum alloy. The second material can be the same or different from the first material, and the second alloy can be the same or different from the first alloy.

[0018] In some embodiments, the apparatus may further include a showerhead backplate having a plurality of through holes equal in number to the first screw holes, a plurality of first threaded fasteners equal in number to the first screw holes, a plurality of washers at least equal in number to the first screw holes, and a plurality of Belleville washers at least equal in number to the first screw holes. Each first threaded fastener of the plurality of first threaded fasteners may be inserted through at least one of the washers, one of the Belleville washers, and one of the through holes and threaded into a corresponding one of the first screw holes, and at least one washer may be inserted between each of the Belleville washers and the showerhead backplate.

[0019] In some such embodiments, one or more of the through holes in the showerhead backplate may be threaded holes having a threaded inner diameter large enough to allow a first threaded fastener to be inserted therein without engagement of the threads of the first threaded fastener with the threads of the threaded hole.

[0020] In some embodiments of the apparatus, the showerhead faceplate may be formed of a first material, the showerhead backplate may be formed of a second material, the first threaded fastener may be formed of a third material, the Belleville washer may be formed of a first alloy, and the washer may be formed of a second alloy. In such embodiments, the first, second, and third materials may each be an aluminum alloy, a 6061-T6 aluminum alloy, or alumina, and the first and second alloys may each be a nickel alloy, an aluminum alloy, or a 6061-T6 aluminum alloy. Each of the first, second, and third materials may be the same material, different materials, or a mixture of the same and different materials. Similarly, the first and second alloys may be the same or different from one another.

[0021] In some embodiments, each first Screw type The fasteners may be tightened to a torque between 0.68 Nm and 0.9 NM (6 inch-pounds and 8 inch-pounds). [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a cross-sectional view of one half of an example showerhead for use in a semiconductor processing system (the example showerhead is generally symmetrical about a central axis).

[0023] [Figure 1A] FIG. 1 is a plan view of a region of a showerhead faceplate showing the pattern of gas distribution holes and posts.

[0024] [Figure 1B] Detail view showing the interface of an alternative showerhead backplate / showerhead faceplate edge.

[0025] [Figure 2] 2 is a cross-sectional view of one half of an example showerhead faceplate similar to that shown in FIG. 1.

[0026] [Figure 2A] Detail view showing another showerhead faceplate having different thermal interference fit features.

[0027] [Figure 3] 2 is a cross-sectional view of one half of an example showerhead backplate and stem similar to that shown in FIG. 1.

[0028] [Figure 3A] Detail view showing another showerhead backplate having different thermal interference fit features.

[0029] [Figure 4] FIG. 2 shows the example showerhead of FIG. 1 along with a thermal displacement map illustrating the thermal displacement effects at high processing temperatures.

[0030] [Figure 5] Exploded view of the showerhead example in Figure 1.

[0031] [Figure 6]1 illustrates a semiconductor processing system according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0032] As mentioned above, the detachable showerhead faceplate systems discussed herein may be particularly useful in high temperature semiconductor processing applications (e.g., applications in which the showerhead faceplate may reach temperatures of 250°C to 350°C), although it should be understood that such systems may be utilized in other semiconductor processing contexts, including higher and lower temperature contexts, with appropriate modifications.

[0033] FIG. 1 is a cross-sectional view of one half of an example showerhead for use in a semiconductor processing system, where the example showerhead is generally symmetrical about a central axis. In FIG. 1, the showerhead 102 features a stem 104 connected at one end to a showerhead backplate 108; the other end (not shown) of the stem 104 may be coupled to the ceiling or lid of a semiconductor processing chamber. As shown, the stem 104 and the showerhead backplate 108 are provided by a single component; however, it is understood that such features may be provided by two or more components assembled into an assembly. Generally speaking, the stem may have a diameter or width that is much smaller than the outer diameter or width of the showerhead backplate 108. In this example, the stem 104 includes a central passageway centered about a first axis 114 through which process gases may be delivered to the showerhead 102. The first axis 114 may be generally perpendicular to the underside of the showerhead faceplate 106 and / or a first thermal contact surface (described below). 1 are generally intended to be permanently mounted within a semiconductor processing chamber (or at least to remain within the semiconductor processing chamber for a period spanning multiple showerhead faceplate changes). While the present example is directed to a chandelier-style showerhead with a removable faceplate, it is understood that recessed showerheads may be designed according to similar principles, may include similar features, and are also considered within the scope of the present disclosure.

[0034] The showerhead 102 may further include a removable showerhead faceplate 106, which in the illustrated example features a plurality of gas distribution ports 110 extending therethrough. The showerhead faceplate 106 may be clamped to the showerhead backplate 108 with a clamping force provided by a plurality of fasteners, such as a first threaded fastener 144 and a second threaded fastener 146 (e.g., socket head cap screws). In the illustrated example, each threaded fastener 144 or 146 is paired with a corresponding Belleville washer 148 and washer 150, although the size of each Belleville washer 148 and 150 may be selected differently depending on the desired clamping force. Each first threaded fastener 144 may be inserted through a corresponding hole in the showerhead backplate 108 and threaded into a first threaded hole 140 in the showerhead faceplate 106. Similarly, a second threaded fastener 146 may be inserted through a corresponding hole in the showerhead backplate 108 and threaded into the second threaded hole 142 .

[0035] In the illustrated example showerhead 102, each second screw hole 142 is located at the end of a corresponding post 116 that projects upward from the surface of the showerhead faceplate 106 toward the showerhead backplate 108. In some embodiments (such as the illustrated embodiment), the posts 116 (if utilized) may be tapered or otherwise shaped such that the cross-sectional area of ​​each post 116 in a plane perpendicular to the first axis 114 decreases before reaching the surface of the showerhead faceplate 106 from which it extends. In such an embodiment, this may allow the spacing between gas distribution ports 110 to be smaller than the diameter or cross-sectional width of the posts 116 where they join the showerhead backplate 108, thereby allowing for increased thermal contact between the posts 116 and the showerhead backplate 108 and an increase in material in that region, which may strengthen the threaded joint in the region of the second threaded hole 142 without substantially affecting the spacing of the gas distribution ports 110. (For example, the increased diameter of the post 116 may be used to accommodate a threaded insert (as shown in the figure, no threaded insert is shown, but it is understood that a threaded insert such as a helical insert (e.g., Helicoil™) may be used in such a threaded hole), which may provide a stronger threaded joint than could be achieved using the post material alone.) Note that in FIG. 1 , the cut plane is through the center of the right-most post 116 and the center of the showerhead 102, and the gas distribution ports 110 are shown in a position that may not actually be representative of their spacing in this plane. 1A , each post 116 may be centered over a group of three adjacent gas distribution ports 110′ such that an outer edge 116′ of the post 116 where the post 116 meets the surface of the showerhead faceplate 106 approximately abuts each of the three gas distribution ports 110′. In such a scenario, no cutting plane passes through the center of the post 116 and two or more of the three adjacent gas distribution ports 110′.In contrast, there are two gas distribution ports 110 shown immediately adjacent to the right-most post 116 in Figure 1. Such a configuration is not possible with gas distribution ports 110 arranged in a triangular pattern as described above with respect to Figure 1A (although such a cross-sectional view may exist for a square pattern of gas distribution ports 110, which is also considered within the scope of the present disclosure). Thus, it should be understood that the arrangement of gas distribution ports 110 in the figure is merely to provide an understanding of the gas distribution ports 110 generally distributed across the underside of the showerhead 102, and is not representative of an actual cross-section of such a showerhead faceplate.

[0036] 1 is the inclusion of an inner wall 152 that projects from the surface of the showerhead faceplate 106 into a receiving groove in the showerhead backplate 108. As can be seen, a small gap 154 ​​exists between the outward facing surface of the inner wall 152 and the inward facing surface of the groove in the showerhead backplate 108 that receives the inner wall 152.

[0037] Another configuration is shown in FIG. 1B, in which an inner wall 152′ is disposed on the showerhead backplate 108′ and projects into a corresponding groove on the showerhead faceplate 106′, with a gap 154′ formed between the inward-facing surface of the inner wall 152′ and the outward-facing surface of the groove that receives the inner wall 152′.

[0038] The showerhead faceplate 106 can be easily removed from the showerhead backplate 108 by simply removing the first threaded fastener 144 and the second threaded fastener 146 from the showerhead backplate, and then allowing the showerhead faceplate 106 to fall off the showerhead backplate 108 and be moved from under the showerhead backplate 108 when the threaded fasteners are removed. A new showerhead faceplate 106 can then be installed. The various radial interfaces between the showerhead faceplate 106 and the showerhead backplate 108 (e.g., the holes in the showerhead backplate 108 for receiving the posts 116 and the grooves in the showerhead backplate 108 for receiving the interior walls 152) can be sized to be a clearance fit at room temperature, thereby allowing the showerhead faceplate 106 to fall freely off the showerhead backplate 108 (at room temperature) when the support provided by the threaded fasteners 144 and 146 is removed.

[0039] During semiconductor processing operations, the showerhead 102 can absorb a significant amount of heat resulting from the semiconductor fabrication process. For example, a large amount of heat can be radiatively transferred to the showerhead 102 from a heated pedestal or chuck used to support a wafer during semiconductor processing operations. Additional heat can be transferred between the showerhead 102 and the wafer being processed, for example. withsome of the heat transferred to the showerhead 102 may be conducted to the showerhead backplate 108 through the plenum space (and the gas therein), but more of the heat transferred to the showerhead 102 may be conducted to the showerhead backplate 108 by conductive heat transfer through the posts 116 and around the periphery of the showerhead faceplate 106 where the first screw holes 140 are located. The heat may then flow up the stem 104 and generally inward through the showerhead backplate 108 before being transferred to the ambient environment (or the chamber housing and / or cooling system).

[0040] In conventional showerheads with permanently attached showerhead faceplates (e.g., showerhead faceplates welded or brazed in place), there is little or no loss in heat transfer efficiency across the area where the showerhead faceplate contacts the showerhead backplate. However, the inventors have recognized that showerheads with removable faceplates, such as the one shown in FIG. 1, can present particular challenges with regard to heat transfer. In particular, if there is poor heat transfer across the interface between the showerhead faceplate 106 and the showerhead backplate 108, this can prevent heat from flowing out of the showerhead faceplate 106 at a rate sufficient to maintain the desired operating temperature of the showerhead faceplate. For example, it may be desirable to maintain a showerhead faceplate temperature between 200°C and 250°C with a temperature variation of 15°C or less across the showerhead faceplate; if the heat flow from the showerhead faceplate to the showerhead backplate is insufficient to prevent an undesirable amount of heat buildup in the showerhead faceplate 106, the temperature of the showerhead faceplate 106 may exceed the temperature desired for the particular semiconductor process being performed, which in turn may increase potential outgassing from the metal of the showerhead faceplate 106 that could contaminate wafers being processed. Furthermore, higher temperatures at the showerhead faceplate may result in a larger temperature difference between the showerhead faceplate 106 and the showerhead backplate 108, which in turn may result in larger thermal expansion of the showerhead faceplate 106 compared to the showerhead backplate 108, which may lead to undesirable deformation of the showerhead faceplate 106.

[0041] To provide more effective heat transfer between the showerhead faceplate 106 and the showerhead backplate 108, the removable showerhead faceplate (such as that shown in FIG. 1) may feature various flat thermal contact surfaces configured to contact corresponding flat thermal contact surfaces disposed on the showerhead backplate when the showerhead faceplate 106 is installed in the showerhead 102.

[0042] FIG. 2 is a cross-sectional view of one half of an example showerhead faceplate similar to that shown in FIG. 1 . In FIG. 2 , the showerhead faceplate 106 is shown detached from the showerhead backplate 108. The showerhead faceplate 106 may have a plurality of first thermal contact surfaces 118, which may include, for example, end post thermal contact surfaces 124 and annular thermal contact surface 122. The first thermal contact surfaces 118 may all be generally parallel to one another, although, as can be seen, some of the first thermal contact surfaces 118 may be at different heights relative to one another. For ease of reference, the first thermal contact surfaces 118 are shown with dashed lines that are vertically offset somewhat upward from the actual first thermal contact surfaces 118. The end post thermal contact surfaces 124 may be located, for example, at the ends of the posts 116 where the posts 116 are intended to contact the showerhead backplate 108 (e.g., at the top ends of the posts 116). The posts 116 may be arranged in one or more generally circular patterns disposed about the first axis 114 and may provide a heat transfer path from the showerhead faceplate 106 to the showerhead backplate 108 and structural support for the central portion of the showerhead faceplate 106, for example, to prevent the central portion of the showerhead faceplate from sagging.

[0043] An additional or alternative heat transfer path may be provided by an annular thermal contact surface 122, which may, for example, surround the plate region 112 of the showerhead faceplate 106 when viewed along the first axis 114. The plate region 112 of the showerhead faceplate 106 may generally refer to the region of the showerhead faceplate 106 where the gas distribution ports 110 are located, and may, for example, extend from the center of the showerhead faceplate 106 to an inward-facing surface of the showerhead faceplate 106 defined by the wall or annular raised region of the showerhead faceplate 106 (or a similar surface on a showerhead backplate). The annular thermal contact surface 122 may, for example, be the top surface of the wall or annular raised region of the showerhead faceplate.

[0044] Some such flat thermal contact surfaces may have very low flatness specifications for features of such size. For example, the showerhead faceplate 106 may have a nominal diameter of about 15 inches (e.g., between 12 inches and 18 inches), and the annular thermal contact surface 122 of the showerhead faceplate 106 (which may have a similar outer diameter) may have a flatness maintained across the entire annular thermal contact surface 122 to a value between 800 μin and 1200 μin (or less) (e.g., 1000 μin). Similarly, the surface roughness of the thermal interface may be maintained at a value of, for example, Ra between 0.61 μm and 0.76 μm (24 μin and 30 μin) or Ra between 0.61 μm and 1.02 μm (24 μin and 40 μin) (or less). It is understood that such flatness tolerances are not typical for features of such size, especially features intended to be clamped together.

[0045] In some embodiments, the showerhead faceplate 106 may include a first thermal interference fit feature 126 in addition to including features for providing good thermal contact between the showerhead faceplate 106 and the showerhead backplate 108. The first thermal interference fit feature 126 may be provided by a first axisymmetric surface 130 defined by a first cross-sectional profile 132. For example, the first axisymmetric surface 130 may have a first diameter 136 and may be an outwardly facing conical or cylindrical surface provided, for example, by an interior wall 152. As can be seen in FIG. 1B , other embodiments may provide the first axisymmetric surface 130 by an outwardly facing surface of a groove that can receive an interior wall feature disposed on the showerhead backplate 108.

[0046] FIG. 3 is a cross-sectional view of one half of an example showerhead backplate and stem similar to that shown in FIG. 1. As seen in FIG. 3, the showerhead backplate 108 can include a second planar thermal contact surface 120, which can correspond in position to the first thermal contact surface 118 on the showerhead faceplate 106. The showerhead backplate 108 can also include a second thermal interference fit feature 128, which can have a second cross-sectional profile 134, which can define, for example, a second axisymmetric plane. FIG. 3A is a detailed view illustrating an alternative showerhead backplate design similar to that shown in FIG. 1B, in which the showerhead backplate 108′ can have an inner wall 152′ providing an inwardly facing second thermal interference fit feature 128, which can have a second cross-sectional profile 134′.

[0047] The dimensions of the showerhead faceplate 106 and the showerhead backplate 108 may be controlled so that a gap 154 ​​exists (and defines a clearance fit or other fit that allows for easy removal of the showerhead faceplate 106) when the showerhead faceplate 106 and the showerhead backplate 108 are both at nominal room temperature (e.g., 20° C.), but the gap decreases to approach an intermediate or gentle interference fit when the showerhead 102 reaches a steady-state operating condition. This serves to center the showerhead faceplate 106 relative to the showerhead backplate 108 while also establishing a substantially airtight seal between the showerhead backplate 108 and the showerhead faceplate 106 when the showerhead backplate 108 and the showerhead faceplate 106 are at a steady-state operating condition. For example, at room temperature, a gap of about 0.030 cm (about 0.012 inches) (e.g., 0.009 inches to 0.015 inches or 0.010 inches to 0.014 inches) may be provided, which may disappear entirely when the showerhead faceplate 106 reaches a steady-state operating temperature. For example, the gap may be reduced to zero or may change to a compressive interface, e.g., the gap may allow compressive deformation of up to a few parts per thousand (e.g., between about 0.005 inches and 0.010 inches) between the showerhead faceplate 106 and the showerhead backplate 108.

[0048] To better illustrate how such a sealing effect is provided, reference is made to FIG. 4, which illustrates the example showerhead of FIG. 1 along with a thermal displacement map illustrating the effects of thermal displacement at elevated processing temperatures. As can be seen in FIG. 4, the outer periphery of the showerhead faceplate 106, compared to the showerhead backplate 108, experiences a greater radial thermal displacement due to increased temperature in the showerhead faceplate 106 than a corresponding location on the showerhead backplate 108. Thus, the inner wall 152 and the first axisymmetric surface 130 generally experience a greater radial outward thermal displacement than a second axisymmetric surface of the groove in the showerhead backplate 108 that faces the first axisymmetric surface 130, which may thereby close the gap 154. In this manner, a temperature mismatch between the showerhead backplate 108 and the showerhead faceplate 106 creates a thermal expansion mismatch that allows the gap 154 ​​between the showerhead faceplate 106 and the showerhead backplate 108 to be closed, creating an interference or transition fit 156, even if the showerhead faceplate 106 and the showerhead backplate 108 are formed from materials with similar thermal expansion properties. For example, for a showerhead backplate 108 and a showerhead faceplate 106 that are both formed from an aluminum alloy (e.g., 6061-T6 aluminum), the gap 154 ​​between the first plane of axisymmetry 130 and the second plane of axisymmetry can be on the order of 0.025 cm (0.01 inch) when the showerhead 102 is at room temperature. In other words, the difference between first diameter 136 and second diameter 138 may be on the order of 0.02 inches when the showerhead is at room temperature, but may approach 0 inches when heated to a temperature between 280°C and 320°C.

[0049] Detachable showerhead faceplates (such as those discussed herein) may also include features designed to address potential problems that may arise during use. For example, showerhead faceplates and backplates formed from aluminum alloys may experience various issues that may prevent the use of fastener systems that may be used to attach the showerhead faceplate to the showerhead backplate. For example, if a different material (e.g., stainless steel or Inconel) is used for the fasteners than the showerhead backplate 108 and showerhead faceplate 106, this may cause the threaded connections to loosen during temperature cycling. For example, if stainless steel threaded fasteners are used, the stainless steel fasteners may expand to a much lesser extent than the aluminum components as a result of the different thermal expansion characteristics of the stainless steel of the fasteners and the aluminum alloy of the showerhead components. This may increase the preload in such fasteners when heated to operating conditions, which may in turn cause permanent localized deformation in the aluminum components, such that the stainless steel fasteners may have a much lower preload than required when the showerhead cools down again. In some cases, the preload can almost completely disappear, leading to a loose connection that can generate particles and affect wafer processing uniformity.

[0050] Another problem that can occur with some fasteners (especially those with higher torque requirements) is that the showerhead faceplate can diffusion bond to the showerhead backplate at one or more locations of the flat thermal contact surface when held at high temperatures and under a sufficiently high clamping load, as can occur during steady-state operating conditions in a semiconductor processing chamber, for example. Such a diffusion bond can effectively permanently or semi-permanently secure the showerhead faceplate to the showerhead backplate, even when the threaded fasteners that clamped the showerhead faceplate to the showerhead backplate are removed. This can prevent the showerhead faceplate from being removed, or, if the showerhead faceplate is still removable, can cause damage to the flat thermal contact interface, essentially pulling the bonded portions of the showerhead faceplate and / or showerhead backplate away from one or the other of those components.

[0051] Because the operating temperature of such detachable showerhead faceplates is not easily altered (determined by the requirements of the semiconductor process in which the showerhead is utilized), the primary mechanism for reducing the likelihood of such diffusion bonding is to reduce the clamping force applied across the showerhead faceplate / showerhead backplate interface. However, reducing the preload on the threaded fasteners to the extent necessary to prevent diffusion bonding at the clamped location (to reduce the clamping force) often results in a drastic reduction in preload after temperature cycling, which loosens the bolted joint, reduces thermal transmittance across the bolted joint, and potentially leads to gas leakage through the bolted joint. For example, tests were performed using various 6-32 socket head bolts (SHCS) to clamp the showerhead faceplate and showerhead backplate. Both the showerhead faceplate and showerhead backplate were formed from an aluminum alloy (e.g., 6061-T6), and the threaded holes in the showerhead faceplate that receive the SHCS were equipped with high-nickel alloy threaded inserts (e.g., helical inserts). For example, different configurations of threaded fasteners were used in different locations, including both aluminum alloy (6061-T6) SHCSs and high-nickel alloy SHCSs. Additionally, different load distribution mechanisms were tested with each SHCS, such as no such load distribution mechanism (SHCS in direct contact with the showerhead backplate), the use of a single flat washer between the SHCS and the showerhead backplate, the use of a single Belleville washer between the SHCS and the showerhead backplate, the use of a single Belleville washer and a single flat washer between the SHCS and the showerhead backplate, the use of two Belleville washers and a single flat washer in both series and parallel between the SHCS and the showerhead backplate, and the use of three Belleville washers and a single flat washer in series between the SHCS and the showerhead backplate.

[0052] Belleville washers (e.g., Belleville washers) are machined to have upper and lower surfaces that are nested truncated cones. In a Belleville washer, for example, the outer and inner edges of the washer may be a) on opposite sides of the washer, b) farther apart than the distance between the other inner and outer edges of the washer, and c) farther apart than the vertical distance between the top and bottom surfaces of the washer. In such cases, when a compressive load is applied to the inner and outer edges along the centerline of the washer, the compressive load may begin to elastically deform and flatten the washer from a conical shape to the shape of a plain washer. Belleville washers provide a relatively stiff spring with a short travel distance.

[0053] It was also discovered that using high-nickel alloy SHCSs tightened to a torque of 5 in-lb and employing the load distribution mechanism described above prevented diffusion bonding from occurring, but most experienced significant preload loss (e.g., greater than 50%) after reaching the desired operating temperature between 250°C and 350°C. For clarity, a high-nickel alloy is an alloy in which nickel is the most abundant element in the alloy's composition. Tightening high-nickel alloy SHCSs to a torque greater than 5 in-lb (e.g., 6.5 in-lb) was found to mitigate preload loss under temperature cycling, but the diffusion bonding issue reoccurred as a result. Utilizing more complex Belleville spring washer configurations (e.g., multiple Belleville spring washers in series) was also found to mitigate preload loss, but required additional components and increased the potential for incorrect assembly due to the possibility of additional Belleville spring washers being omitted or incorrectly oriented. For clarity, parallel Belleville spring washers are stacked so that the conical faces of the Belleville spring washers are nested and point in the same direction. The Belleville washers in a series are stacked (appearing "pleated" from the side) so that every other washer on one side faces one way and the other faces the other way.

[0054] More satisfactory results were observed when using aluminum alloy SHCSs tightened to a torque value of approximately 4 in-lb, and it was found that using a single Belleville washer and a single flat washer with such SHCSs resulted in over 80% of the preload being retained even after multiple temperature cycles. While more complex Belleville washer embodiments were not tested against aluminum alloy SHCSs, a range of Belleville washer embodiments may similarly provide acceptable preload performance with such SHCSs. Similar results were observed when performing similar tests with a 10-24 SHCS, used in one embodiment as the first threaded fastener and tightened to a torque value between 6 and 8 in-lb, e.g., 7 in-lb, to achieve the desired degree of preload.

[0055] The flat and disc spring washers used were made of a high-nickel alloy (e.g., Inconel), with the high-nickel alloy being used due to its high strength and chemical resistance. The use of flat washers in such joints can help distribute the end load of the disc spring washer sandwiched between the flat washer and the SHCS (which prevents the end of the disc spring washer from directly contacting the showerhead backplate material). For showerhead backplates made of aluminum alloys, this can reduce the chance of the disc spring washer abrading or gouging the showerhead backplate material (which can lead to undesirable particle generation) when it is compressed and radially expanded by the tightening of the SCHS.

[0056] The use of Belleville spring washers allows the preload applied to the joint to be governed primarily by the deformation of the Belleville spring washers, rather than primarily by the stretching of the SHCS (which, due to its much higher spring constant, requires little displacement to transition between an unpreloaded and a significantly preloaded state). The Belleville spring washers have a wider range of travel, allowing the preload to be maintained below a desired minimum over a wider range of potential displacement due to thermal expansion, thereby avoiding the possibility of loosening of the showerhead faceplate / showerhead backplate bond during temperature cycling and the possibility of undesirable diffusion bonding of the showerhead faceplate and showerhead backplate, while allowing an adequate clamping force to be maintained to promote good thermal contact between the showerhead faceplate and the showerhead backplate.

[0057] Figure 5 shows an exploded view of the example showerhead of Figure 1. As can be seen, each first threaded fastener 144 and second threaded fastener 146 is inserted through a corresponding hole in the showerhead backplate 108 and threaded first through a Belleville washer 148 and then a flat washer 150 (or simply "washer") before being threaded into the first threaded hole 140 and second threaded hole 142, respectively.

[0058] Furthermore, it is understood that the number of first threaded fasteners used can be much greater than is typically required for structural support of the showerhead faceplate 106. For example, six or eight threaded fasteners arranged around the periphery of the showerhead 102 are typically considered sufficient to structurally support the showerhead faceplate 106. However, in some embodiments of a removable showerhead faceplate, many more such fasteners may be used. For example, it has been found that increasing the number of threaded fasteners around the periphery of the showerhead 102 more evenly distributes the load and, therefore, the thermal contact path for heat flow from the showerhead faceplate. In particular, it has been found that the performance benefits significantly outweigh the additional cost of, for example, 18, 20, 22, 24, or more threaded fasteners arranged around the periphery of the showerhead 102 to secure the showerhead faceplate to the showerhead backplate. Accordingly, in such embodiments, the angular spacing between the threaded holes in the showerhead faceplate around the central axis of the showerhead may be 20° or less.

[0059] In some embodiments, some of the through-holes in the showerhead backplate #HH08 into which threaded fasteners can be inserted before threading into the showerhead faceplate #HH06 can be specially configured to function as faceplate removal features. For example, such through-holes can be threaded holes with a larger thread diameter than the largest diameter of the screws or their shanks of the threaded fasteners inserted therethrough and threaded into the threaded holes in the showerhead faceplate. This allows such holes to be utilized in the same way as other holes to provide a clamping connection between the showerhead faceplate and the showerhead backplate using threaded fasteners. However, if the showerhead faceplate and the showerhead backplate are later found to be difficult to separate after removal of their threaded fasteners, a larger-sized threaded fastener with a thread size that matches the threads provided in the threaded holes in the showerhead backplate can be threaded through such threaded holes until it hits the bottom of the showerhead faceplate. Additional torque applied to such larger size fasteners can then cause the larger size fasteners to push against the showerhead faceplate, causing the showerhead faceplate to separate from the showerhead backplate.

[0060] The various structures discussed herein (e.g., detachable showerhead faceplate, showerhead backplate, first threaded fastener, second threaded fastener, etc.) may be formed from a variety of different materials suitable for use within the harsh environment of a semiconductor processing chamber during semiconductor processing operations. For example, as described above, an aluminum alloy such as 6061-T6 may be used for the showerhead faceplate, showerhead backplate, and first and second threaded fasteners. Using similar materials for such components can reduce the amount of thermal expansion mismatch that can occur between such components, thereby avoiding scenarios in which components are subject to high stresses and potentially fail or behave in undesirable ways. However, some showerheads may use different materials for some or all of these components. For example, high-nickel alloy threaded fasteners may be used in some embodiments featuring aluminum alloy showerhead faceplates and showerhead backplates. Other materials that can be used to provide the showerhead faceplate and showerhead backplate include ceramic, aluminum oxide, and other aluminum alloys.

[0061] The threaded fasteners, Belleville washers, and flat washers described above may be formed from various alloys, such as high-nickel alloys such as Inconel, aluminum alloys such as 6061-T6, or other alloys. It may be advantageous to use multiple materials in areas experiencing high stress (e.g., the threaded joint interface and the washer-load / fastener-load area) to avoid diffusion bonding across those interfaces. Thus, for example, the washers (both flat and Belleville washers) may be formed from a high-nickel alloy in some embodiments, while the faceplate and backplate of the showerhead may be formed from an aluminum alloy.

[0062] It is understood that the showerheads discussed herein may be used in a semiconductor processing tool (e.g., an apparatus configured to include one or more semiconductor processing chambers configured to receive semiconductor wafers or other substrates and perform one or more semiconductor processing operations thereon). FIG. 6 illustrates an example of a semiconductor processing system according to the present disclosure. In FIG. 6, a semiconductor processing chamber 101 is shown including a wafer support 103 configured to support a wafer 105 therein during processing operations. The processing chamber 101 may further include a showerhead 102, as discussed herein, which may be fluidly connected to one or more process gas sources 111. In some embodiments, the showerhead 102 may be configured to function as an electrode used to ignite and / or sustain a plasma 107 that may be generated above the wafer 105. In such embodiments, the showerhead 102 may be electrically connected to, for example, a radio frequency generator 109.

[0063] It should be understood that, when used herein, phrases such as "for each <item> of one or more <items>," "for each <item> of one or more <items>," and the like, include both single-item groups and multiple-item groups; i.e., the phrase "for each" is used in the sense used in programming languages ​​to refer to each item in any collection of items. For example, if the collection of items referred to is a single item, then "each" refers only to that single item and does not imply that there must be at least two of those items (even though dictionary definitions of "each" often define the term to refer to "every one of two or more"). Similarly, the terms "set" or "subset" should not, in and of themselves, be considered to necessarily include multiple items; it is understood that a set or subset may include only one member or multiple members (unless the context suggests otherwise).

[0064] The use of ordinal numbers (e.g., (a), (b), (c), etc., or the like) in this disclosure and claims should not be understood to imply any particular order or sequence unless such order or sequence is explicitly indicated. For example, where there are three steps labeled (i), (ii), and (iii), these steps may be performed in any order (or simultaneously, if not otherwise appropriate) unless otherwise indicated. For example, if step (ii) involves manipulation of an element produced in step (i), step (ii) may be considered to be performed at some time after step (i). Similarly, if step (i) involves manipulation of an element produced in step (ii), it should be understood that the opposite is true.

[0065] Terms such as "about," "approximately," "substantially," "nominal," and the like, when used in reference to a quantity or similar quantifiable characteristic, should be understood to include values ​​within ±10% of the specified value or relationship (as well as including the actual value or relationship specified), unless otherwise indicated.

[0066] It is to be understood that all combinations of the above concepts (provided such concepts are not mutually inconsistent) are contemplated as part of the inventive subject matter disclosed herein. In particular, all combinations of the subject matter of the claims appearing at the end of this disclosure are contemplated as part of the inventive subject matter disclosed herein. It is also to be understood that terms explicitly used herein, which may also appear in any disclosure incorporated by reference, are to be given the meaning most consistent with the particular concepts disclosed herein.

[0067] Furthermore, while the above disclosure focuses on one or more particular embodiments, it should be understood that it is not limited to only the above-described examples, but is also applicable to similar modifications and mechanisms, and such similar modifications and mechanisms are also considered to be within the scope of the present disclosure. The present invention can be realized, for example, in the following manner. Application example 1: 1. An apparatus comprising: Equipped with a shower head faceplate, the showerhead faceplate is configured to removably engage with a showerhead backplate; the showerhead faceplate has a plate region in which a plurality of gas distribution ports are disposed; each gas distribution port extends through the showerhead faceplate; the showerhead faceplate comprises one or more first planar thermal contact surfaces, each configured to contact a corresponding second planar thermal contact surface on the showerhead backplate when the showerhead faceplate is engaged with the showerhead backplate; the one or more first flat thermal contact surfaces comprise an annular flat thermal contact surface having an outer diameter between 12 inches and 18 inches (30.5 cm and 38.1 cm) and surrounding the plate area when viewed along a first axis perpendicular to the annular flat thermal contact surface; The annular flat thermal contact surface has a flatness of not more than a value between 20.3 μm and 30.5 μm (800 μin and 1200 μin) and a surface roughness Ra of not more than a value between 0.61 μm and 1.02 μm (24 μin and 40 μin). Application example 2: An apparatus as described in Application Example 1, further comprising a plurality of posts disposed within and extending from the plate region, wherein the one or more first flat thermal contact surfaces include, for each of the posts, an end post thermal contact surface parallel to the annular flat thermal contact surface. Application example 3: The apparatus according to Application Example 2, wherein the first flat thermal contact surface has a flatness of 25.4 μm (1000 μin) or less and an average surface roughness Ra of 1.02 μm (24 μin) or more. Application example 4: An apparatus according to Application Example 2, wherein the first flat thermal contact surface has a flatness of 25.4 μm (1000 μin) or less and an average surface roughness Ra of 0.76 μm (30 μin) or more. Application example 5: The apparatus according to Application Example 2, wherein the first flat thermal contact surface has a flatness of 25.4 μm (1000 μin) or less and an average surface roughness Ra of 1.02 μm (40 μin) or more. Application example 6: The apparatus according to Application Example 1, wherein the showerhead faceplate is made of an aluminum alloy. Application example 7: The device according to Application Example (Error: No Reference) 1, the showerhead faceplate includes a plurality of first screw holes distributed around the plate area and disposed within the annular flat thermal contact surface. Application example 8: The device according to Application Example 7, The first screw holes are arranged in a circular array with an angular spacing between adjacent first screw holes of 20 degrees or less. Application example 9: The device according to Application Example 7, the showerhead faceplate further comprising a first thermal interference fit feature configured to mate with a second thermal interference fit feature on the showerhead backplate when the showerhead faceplate is engaged with the showerhead backplate; the first thermal interference fit feature comprises a first axisymmetric surface facing radially outwardly and disposed between the plate region and the first screw hole; the first axisymmetric plane has a first cross-sectional profile dimensioned to be within 0.01 inches to 0.014 inches of a corresponding second cross-sectional profile of the second thermal interference fit feature on the showerhead backplate when the showerhead faceplate is engaged to the showerhead backplate so that the showerhead faceplate is centered with respect to the showerhead backplate and when the showerhead faceplate and the showerhead backplate are both at 20°C. Application example 10: The device according to Application Example 9, the first thermal interference fit feature is a first cylindrical surface having a first diameter; the second thermal interference fit feature on the showerhead backplate that the first thermal interference fit feature is configured to mate with when the showerhead faceplate is attached to the showerhead backplate is a second cylindrical surface having a second diameter; the first diameter is smaller than the second diameter and is within 0.02" of the second diameter when the showerhead faceplate and the showerhead backplate are both at 20°C. Application example 11: The device according to Application Example 10, the showerhead faceplate includes an inner wall extending around the plate area and sandwiched between the first screw hole and the plate area; the inner wall extends from the annular flat thermal contact surface; The apparatus, wherein the first thermal interference fit feature is provided by an outwardly facing surface of the inner wall. Application example 12: The device according to Application Example 9, further comprising: a plurality of first threaded fasteners, the number of which is equal to the number of the first screw holes; a plurality of washers, the number of which is at least equal to the number of the first screw holes; a plurality of disc spring washers at least equal in number to the number of the first screw holes; Equipped with The apparatus is a kit configured to facilitate replacement of an expired showerhead faceplate attached to the showerhead backplate of a semiconductor processing tool. Application example 13: The device according to Application Example 12, the showerhead faceplate is formed of a first material; the first threaded fastener is formed from a second material; the disc spring washer is formed of a first alloy; the washer is formed from a second alloy; the first material and the second material are each selected from the group consisting of an aluminum alloy, a 6061-T6 aluminum alloy, and alumina; the first alloy and the second alloy are each selected from the group consisting of a nickel alloy, an aluminum alloy, and a 6061-T6 aluminum alloy; the second material is selected from the group consisting of the first material and a material other than the first material; The apparatus, wherein the second alloy is selected from the group consisting of the first alloy and an alloy other than the first alloy. Application 14: The device according to Application Example 9, further comprising: the showerhead backplate having a plurality of through holes equal in number to the first screw holes; a plurality of first threaded fasteners, the number of which is equal to the number of the first screw holes; a plurality of washers, the number of which is at least equal to the number of the first screw holes; a plurality of disc spring washers at least equal in number to the number of the first screw holes; Equipped with each first threaded fastener of the plurality of first threaded fasteners is inserted through at least one of the washers, one of the Belleville spring washers, and one of the through holes and threaded into a corresponding one of the first screw holes; At least one washer is interposed between each of the Belleville spring washers and the showerhead backplate. Example 15: The device according to Application Example 14, one or more of the through holes in the showerhead backplate are threaded holes having a threaded inner diameter large enough for the first threaded fastener to be inserted therethrough without engagement of threads of the first threaded fastener with threads of the threaded hole. Application 16: The device according to Application Example 14, the showerhead faceplate is formed of a first material; the showerhead backplate is formed of a second material; the threaded fastener is formed from a third material; the disc spring washer is formed of a first alloy; the washer is formed from a second alloy; the first material, the second material, and the third material are each selected from the group consisting of an aluminum alloy, a 6061-T6 aluminum alloy, and alumina; the first alloy and the second alloy are each selected from the group consisting of a nickel alloy, an aluminum alloy, and a 6061-T6 aluminum alloy; the second material is selected from the group consisting of the first material, the third material, and a material other than the first material and the third material; the third material is selected from the group consisting of the first material, the second material, and a material other than the first material and the second material; The apparatus, wherein the second alloy is selected from the group consisting of the first alloy and an alloy other than the first alloy. Application 17: The apparatus of Application Example 14, wherein each first fastener is tightened to a torque between 0.68 Nm and 0.9 Nm (6 inch-pounds and 8 inch-pounds).

Claims

1. 1. An apparatus comprising: Equipped with a shower head faceplate, the showerhead faceplate is configured to removably engage with a showerhead backplate; the showerhead faceplate has a plate region in which a plurality of gas distribution ports are disposed; each gas distribution port extends through the showerhead faceplate; the showerhead faceplate comprises one or more first planar thermal contact surfaces, each configured to contact a corresponding second planar thermal contact surface on the showerhead backplate when the showerhead faceplate is engaged with the showerhead backplate; the one or more first flat thermal contact surfaces comprise an annular flat thermal contact surface having an outer diameter between 12 inches and 18 inches (30.5 cm and 45.7 cm) and surrounding the plate area when viewed along a first axis perpendicular to the annular flat thermal contact surface; The annular flat thermal contact surface has a flatness of 30.5 μm (1200 μin) or less and a surface roughness Ra of 1.02 μm (40 μin) or less.

2. 10. The apparatus of claim 1, further comprising a plurality of posts disposed within and extending from the plate region, wherein the one or more first flat thermal contact surfaces include, for each of the posts, an end post thermal contact surface parallel to the annular flat thermal contact surface.

3. 3. The apparatus of claim 2, wherein the first flat thermal contact surface has a flatness of 25.4 microns (1000 microns) or less and an average surface roughness Ra of 0.61 microns (24 microns) or more.

4. 3. The apparatus of claim 2, wherein the first flat thermal contact surface has a flatness of 25.4 microns (1000 microns) or less and an average surface roughness Ra of 0.76 microns (30 microns) or more.

5. 3. The apparatus of claim 2, wherein the first flat thermal contact surface has a flatness of 25.4 μm (1000 μin) or less and an average surface roughness Ra of 1.02 μm (40 μin) or more.

6. 10. The apparatus of claim 1, wherein the showerhead faceplate is formed from an aluminum alloy.

7. 10. The apparatus of claim 1, the showerhead faceplate includes a plurality of first screw holes distributed around the plate area and disposed within the annular flat thermal contact surface.

8. 8. The apparatus of claim 7, The first screw holes are arranged in a circular array with an angular spacing between adjacent first screw holes of 20 degrees or less.

9. 8. The apparatus of claim 7, the showerhead faceplate further comprising a first thermal interference fit feature configured to mate with a second thermal interference fit feature on the showerhead backplate when the showerhead faceplate is engaged with the showerhead backplate; the first thermal interference fit feature comprises a first axisymmetric surface facing radially outwardly and disposed between the plate region and the first screw hole; the first axisymmetric plane has a first cross-sectional profile dimensioned such that when the showerhead faceplate is engaged with the showerhead backplate so that the showerhead faceplate is centered with respect to the showerhead backplate and when the showerhead faceplate and the showerhead backplate are both at 20° C., a clearance of 0.01" to 0.014" exists between the first axisymmetric plane and a corresponding second axisymmetric plane of the second thermal interference fit feature on the showerhead backplate.

10. 10. The apparatus of claim 9, the first thermal interference fit feature is a first cylindrical surface having a first diameter; the second thermal interference fit feature on the showerhead backplate that the first thermal interference fit feature is configured to mate with when the showerhead faceplate is attached to the showerhead backplate is a second cylindrical surface having a second diameter; the first diameter is smaller than the second diameter and is within 0.02" of the second diameter when the showerhead faceplate and the showerhead backplate are both at 20°C.

11. 11. The apparatus of claim 10, the showerhead faceplate includes an inner wall extending around the plate area and sandwiched between the first screw hole and the plate area; the inner wall extends from the annular flat thermal contact surface; The apparatus, wherein the first thermal interference fit feature is provided by an outwardly facing surface of the inner wall.

12. 10. The apparatus of claim 9, further comprising: a plurality of first threaded fasteners, the number of which is equal to the number of the first screw holes; a plurality of washers, the number of which is at least equal to the number of the first screw holes; a plurality of disc spring washers at least equal in number to the number of the first screw holes; Equipped with The apparatus is a kit configured to facilitate replacement of an expired showerhead faceplate attached to the showerhead backplate of a semiconductor processing tool.

13. 13. The apparatus of claim 12, the showerhead faceplate is formed of a first material; the first threaded fastener is formed from a second material; the disc spring washer is formed from a first alloy; the washer is formed from a second alloy; the first material and the second material are each selected from the group consisting of an aluminum alloy, a 6061-T6 aluminum alloy, and alumina; the first alloy and the second alloy are each selected from the group consisting of a nickel alloy, an aluminum alloy, and a 6061-T6 aluminum alloy; the second material is selected from the group consisting of the first material and a material other than the first material; the second alloy is selected from the group consisting of the first alloy and an alloy other than the first alloy.

14. 10. The apparatus of claim 9, further comprising: the showerhead backplate having a plurality of through holes equal in number to the first screw holes; a plurality of first threaded fasteners, the number of which is equal to the number of the first screw holes; a plurality of washers, the number of which is at least equal to the number of the first screw holes; a plurality of disc spring washers at least equal in number to the number of the first screw holes; Equipped with each first threaded fastener of the plurality of first threaded fasteners is inserted through at least one of the washers, one of the Belleville spring washers, and one of the through holes and threaded into a corresponding one of the first screw holes; At least one washer is interposed between each of the Belleville spring washers and the showerhead backplate.

15. 15. The apparatus of claim 14, one or more of the through holes in the showerhead backplate are threaded holes having a threaded inner diameter large enough for the first threaded fastener to be inserted therethrough without engagement of threads of the first threaded fastener with threads of the threaded hole.

16. 15. The apparatus of claim 14, the showerhead faceplate is formed of a first material; the showerhead backplate is formed of a second material; the first threaded fastener is formed from a third material; the disc spring washer is formed from a first alloy; the washer is formed from a second alloy; the first material, the second material, and the third material are each selected from the group consisting of an aluminum alloy, a 6061-T6 aluminum alloy, and alumina; the first alloy and the second alloy are each selected from the group consisting of a nickel alloy, an aluminum alloy, and a 6061-T6 aluminum alloy; the second material is selected from the group consisting of the first material, the third material, and a material other than the first material and the third material; the third material is selected from the group consisting of the first material, the second material, and a material other than the first material and the second material; the second alloy is selected from the group consisting of the first alloy and an alloy other than the first alloy.

17. 15. The apparatus of claim 14, wherein each first threaded fastener is tightened to a torque between 0.68 Nm and 0.9 Nm (6 inch-pounds and 8 inch-pounds).

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