Shield for plasma chambers

Abstract

A shield for a processing chamber includes a body. The body includes a sidewall, a first end, and a second end. The sidewall surrounds a processing volume in the processing chamber. The first end and the second end are attached to respective components of the processing chamber. The shield includes a first set of curved regions at the first end. At least one curved region in the first set of curved regions has an opposite curvature than rest of the curved regions in the first set of curved regions.

Description

SHIELD FOR PLASMA CHAMBERSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 606,925 filed on December 6, 2023. The entire disclosure of the application referenced above is incorporated herein by reference.FIELD

[0002] The present disclosure relates generally to substrate processing systems and more particularly to a shield for plasma chambers used in substrate processing systems.BACKGROUND

[0003] The background description provided here is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.

[0004] A substrate processing system typically includes a plurality of processing chambers (also called process modules) to perform deposition, etching, and other treatments of substrates such as semiconductor wafers. Examples of processes that may be performed on a substrate include, but are not limited to, plasma enhanced chemical vapor deposition (PECVD), chemically enhanced plasma vapor deposition (CEPVD), sputtering physical vapor deposition (PVD), atomic layer deposition (ALD), and plasma enhanced ALD (PEALD). Additional examples of processes that may be performed on a substrate include, but are not limited to, etching (e.g., chemical etching, plasma etching, reactive ion etching, etc.) and cleaning processes.

[0005] During processing, a substrate is arranged on a substrate support assembly such as a pedestal or an electrostatic chuck (ESC) arranged in a processing chamber of the substrate processing system. A computer-controlled robot typically transfers substrates from one processing chamber to another in a sequence in which the substrates are to be processed. During deposition, gas mixtures including one or more precursors are introduced into the processing chamber, and plasma is struck to activatechemical reactions. During etching, gas mixtures including etch gases are introduced into the processing chamber, and plasma is struck to activate chemical reactions. The processing chambers are periodically cleaned by supplying a cleaning gas into the processing chamber and striking plasma.SUMMARY

[0006] A shield for a processing chamber comprises a body. The body comprises a sidewall, a first end, and a second end. The sidewall surrounds a processing volume in the processing chamber. The first end and the second end are attached to respective components of the processing chamber. The shield comprises a first set of curved regions at the first end. At least one curved region in the first set of curved regions has an opposite curvature than rest of the curved regions in the first set of curved regions.

[0007] In additional features, the shield further comprises a second set of curved regions at the second end. At least one curved region in the second set of curved regions has an opposite curvature than rest of the curved regions in the second set of curved regions.

[0008] In additional features, the first set of curved regions comprises convex and concave regions.

[0009] In additional features, the second set of curved regions comprises convex and concave regions.

[0010] In additional features, at least one curved region in the first set of curved regions has a different radius than rest of the curved regions in the first set of curved regions.

[0011] In additional features, at least one curved region in the second set of curved regions has a different radius than rest of the curved regions in the first set of curved regions.

[0012] In additional features, the first set of curved regions is located at a radially inner portion of the first end.

[0013] In additional features, the second set of curved regions is located at a radially inner portion of the second end.

[0014] In additional features, the body comprises a metallic material and a coating. The coating comprises an anodization layer of a first material deposited on the metallic material and plasma spray coating of a second material deposited on the first material.

[0015] In additional features, the body is coated with a coating material. The first set of curved regions induce compressive stresses in the coating material.

[0016] In additional features, the body is coated with a coating material. The second set of curved regions induce compressive stresses in the coating material.

[0017] In additional features, the body comprises a base material coated with a coating material. The first set of curved regions compensates for mismatch between coefficients of thermal expansion (CTEs) of the base material and the coating material.

[0018] In additional features, the body comprises a base material coated with a coating material. The second set of curved regions compensates for mismatch between coefficients of thermal expansion (CTEs) of the base material and the coating material.

[0019] In additional features, the body is coated with a coating material that withstands chemical, thermal, and mechanical stresses in the processing chamber due to tensile residual or tensile stresses induced in the coating material by the first set of curved regions.

[0020] In additional features, the body is coated with a coating material that withstands chemical, thermal, and mechanical stresses in the processing chamber due to tensile residual or tensile stresses induced in the coating material by the second set of curved regions.

[0021] In still other features, a shield for a processing chamber comprises a body comprising a sidewall, a first end, and a second end. The sidewall surrounds a processing volume in the processing chamber. The first end and the second end are attached to respective components of the processing chamber. The shield comprises a first set of curved regions at the first end, and a second set of curved regions at the second end. The first set of curved regions comprises convex and concave regions. The second set of curved regions comprises convex and concave regions.

[0022] In additional features, the first set of curved regions is located at a radially inner portion of the first end. The second set of curved regions is located at a radially inner portion of the second end.

[0023] In additional features, at least one curved region in the first set of curved regions has a different radius than rest of the curved regions in the first set of curved regions. At least one curved region in the second set of curved regions has a different radius than rest of the curved regions in the first set of curved regions.

[0024] 19. The shield of claim 16 wherein the body comprises a metallic material and a coating and wherein the coating comprises an anodization layer of a first material deposited on the metallic material and plasma spray coating of a second material deposited on the first material.

[0025] In additional features, the body is coated with a coating material. The first and second sets of curved regions induce thermal residual stresses in the coating material.

[0026] In additional features, the body comprises a base material coated with a coating material. The first and second sets of curved regions compensate for mismatch between coefficients of thermal expansion (CTEs) of the base material and the coating material.

[0027] In additional features, the body is coated with a ceramic or metal oxide coating material that withstands chemical, thermal, and mechanical stresses in the processing chamber due to tensile residual or tensile stresses induced in the coating material by the first and second sets of curved regions.

[0028] Further areas of applicability of the present disclosure will become apparent from the detailed description, the claims and the drawings. The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the disclosure.BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:

[0030] FIG. 1 shows an example of a substrate processing system comprising a processing chamber that can utilize a shield according to the present disclosure;

[0031] FIG. 2 shows an example of the processing chamber of FIG. 1 comprising the shield according to the present disclosure;

[0032] FIG. 3 shows a perspective view of an example of the shield shown in FIG. 2 according to the present disclosure;

[0033] FIG. 4 shows a top view of the shield shown in FIGS. 2 and 3 according to the present disclosure;

[0034] FIG. 5 shows a bottom view of the shield shown in FIGS. 2 and 3 according to the present disclosure;

[0035] FIG. 6 shows a side view of the shield shown in FIGS. 2 and 3 according to the present disclosure;

[0036] FIG. 7 shows a cross-sectional view of the shield shown in FIGS. 2 and 3 according to the present disclosure;

[0037] FIG. 8 shows a portion of the cross-section of the shield shown in FIG. 7;

[0038] FIG. 9 shows an example of geometric features at a first (top) end of the of the shield shown in FIG. 8; and

[0039] FIG. 10 shows an example of geometric features at a second (bottom) end of the of the shield shown in FIG. 8.

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

[0041] Ion and radical bombardment from plasma can damage inner walls and other components of processing chambers used to process substrates. Additionally, during deposition processes, materials can get deposited on the inner walls and the other components of the processing chambers. During etching processes, materials of the inner walls and other components of the processing chamber can get partially etched, which can erode the inner walls and the other components of the processing chambers.

[0042] To protect the inner walls and other components of a processing chamber from the ion and radical bombardment and from undesirable deposition and etching of materials, a shield can be disposed along the inner walls of the processing chamber. The shield may extend from a top end of the processing chamber to a midpoint of the processing chamber. For example, the midpoint of the processing chamber may be a top end of a well in the processing chamber in which a pedestal is disposed. The shield encompasses (surrounds) a processing volume of the processing chamber in which plasma is generated to process a substrate or to clean the processing chamber.

[0043] The shield is generally cylindrical but can be of any other suitable shape. The shield comprises a base material that is coated with a coating. The base material comprises a metallic material. For example, the metallic material can comprise a metal or an alloy comprising a metal. The coating can comprise an anodization layer of a first material deposited on the base material and a plasma spray coating of a second material deposited on the first material. The coating protects the shield from harsh operating conditions in the processing chamber and increases the life and mean time between failures (MTBF) of the shield. For example, the harsh operating conditions include harsh chemistries (e.g., halogens), ions and radicals of the plasma, harsh thermal environment (e.g., wide ranging temperatures such as 20 C to 300 C), and thermally induced mechanical stresses (e.g., tensile and / or compressive stresses). These harsh operating conditions are collectively called chemical, thermal, and mechanical harshness and generate chemical, thermal, and mechanical stresses.

[0044] The coating can prematurely fail (e.g., crack, flake, develop voids and / or interfacial cracks, delaminate, cause spallation, etc.) in some regions of the shield due to many reasons, which can cause particle contamination in the processing chamber. For example, the coating can fail due to a mismatch between coefficients of thermal expansion (CTEs) of the base material of the shield and materials of the coating. The mismatch in the CTEs causes thermal stresses at the interfaces between the base material and the coating materials of the shield. The coating can also fail in some regions of the shield due to the type of geometric configuration (shape) of the regions. The thermally induced mechanical stresses depend on geometric features such as curvature of surfaces of the shield.

[0045] The stresses induce coating failure at various locations, for example, near top and bottom ends of the shield, where shapes of surface of the shield vary. Variations in geometric configuration (shape) influences the integrity and lifetime of the coating. For example, the coating can fail near top and bottom ends of the shield due to the typical convex shape of surfaces near the top and bottom ends of the shield. The convex shape of surfaces near the top and bottom ends of the shield is needed to couple the shield to the processing chamber. The integrity of the coating is high (i.e., failure rate is low) in the region between the top and bottom ends of the shield, which is typically vertical (i.e., straight, without shape variation).

[0046] The present disclosure prevents the failure of the coating by employing a combination of convex and concave surfaces near the top and bottom ends of the shield as described below in detail. Briefly, to improve the lifetime of the coating, geometries of the shield surfaces are optimized. The optimized surface profile of the shield at particular locations (e.g., near the top and bottom ends of the shield) enhances the structural integrity of the coating and prevents failure of the coating at these locations. Preventing failure of the coating at these locations in turn reduces or eliminates particle contamination and particle generation, improves MTBFs, increases component lifetime, etc. in the processing chamber.

[0047] Modifying the geometry of shield surfaces at the particular locations reduces the tensile residual or tensile stresses in the coating at the particular locations. Modifying the geometry of shield surfaces at the particular locations also induces compressive stresses at the particular locations. The compressive stresses reduce crack generation and propagation in the coating. Specifically, the geometric modifications comprise combining concave and convex surfaces near the top and bottom ends of the shield. Adopting the concave-convex surface combination near the top and bottom ends of the shield reduces the stresses on the coating. The combination of concave and convex surfaces lowers strain energy accumulation in the coating. Reduced strain energy accumulation in the coating improves the structural integrity of the coating. The combination of concave and convex surfaces compensates for mismatch between coefficients of thermal expansion (CTEs) of the base material of the shield and materials of the coating. These and other features of the present disclosure are described below in detail.

[0048] The present disclosure is organized as follows. An example of a substrate processing system in which the shield according to the present disclosure can be used is shown and described with reference to FIG. 1. An example of a processing chamber of the substrate processing system of FIG. 1 comprising the shield according to the present disclosure is shown and described with reference to FIG. 2. Various views of the shield are shown and described with reference to FIGS. 3-7. Examples of geometries of the shield according to the present disclosure are shown and described with reference to FIGS. 8-10.EXAMPLE OF SUBSTRATE PROCESSING SYSTEM

[0049] FIG. 1 shows an example of a substrate processing system (hereinafter “the system”) 10 comprising a processing chamber that can utilize a shield according to the present disclosure. The shield is not shown in FIG. 1 but the processing chamber of FIG. 1 with the shield according to the present disclosure is shown in FIG. 2. The system 10 uses inductively coupled plasma to etch substrates. While only one processing chamber is shown, the system 10 may comprise additional processing chambers. The additional processing chambers may perform deposition processes on substrates. The additional processing chambers may also comprise a chamber that performs metrological measurements of the substrates processed in these processing chambers. While the example shows a processing chamber for an etch process, the shield can also be used in a processing chamber in which a deposition process is performed.

[0050] The system 10 includes a coil driving circuit 11. The coil driving circuit 11 includes a radio frequency (RF) source 12, a pulsing circuit 14, and a tuning circuit (i.e., matching circuit) 13. The RF source 12 generates an RF signal. The pulsing circuit 14 controls a transformer coupled plasma (TCP) envelope of the RF signal and varies a duty cycle of TCP envelope (e.g., between 1% and 99%) during operation. The pulsing circuit 14 and the RF source 12 can be combined or separate. The tuning circuit 13 may be directly connected to an inductive coil 16. While a single coil is shown for example, the system 10 may use a plurality of coils (e.g., inner and outer coils). The tuning circuit 13 tunes an output of the RF source 12 to a desired frequency and / or a desired phase, and matches an impedance of the inductive coil 16.

[0051] A dielectric window 24 is arranged along a top end of a processing chamber 28. The processing chamber 28 comprises a substrate support (or pedestal) 30 to support a substrate 34. The substrate support 30 may include an electrostatic chuck (ESC), a substrate support that uses vacuum clamping, mechanical clamping, or other type of substrate support. The substrate support 30 comprises a baseplate 32. The baseplate 32 is made of a metallic material (e.g., aluminum or an alloy). A ceramic plate 33 is arranged on a top surface of the baseplate 32. A thermal resistance layer 36 made of an electrically and thermally insulating material is disposed between the ceramic plate 33 and the baseplate 32. The substrate 34 is arranged on the ceramic plate 33 during processing. A plurality of heaters 35 is arranged in the ceramic plate 33to heat the substrate 34 during processing. For example, the heaters 35 may comprise printed conductive traces embedded in the ceramic plate 33.

[0052] The baseplate 32 further comprises a cooling system 38 to cool the substrate support 30. The cooling system 38 uses a fluid supplied by a fluid delivery system 39 to cool the substrate support 30. In addition, the fluid delivery system 39 can supply the fluid to manifolds (not shown) arranged on the dielectric window 24 to cool portions of the dielectric window 24.

[0053] A gas delivery system 56 is used to supply a process gas mixture to the processing chamber 28. The gas delivery system 56 may include process and inert gas sources 57, a gas metering system 58 including valves and mass flow controllers (MFCs), and a manifold 59. A gas injector 63 may be arranged at a center of the dielectric window 24 and is used to inject gas mixtures from the gas delivery system 56 into the processing chamber 28. Additionally or alternatively, the gas mixtures may be injected from the side of the processing chamber 28.

[0054] When a process gas is supplied to the processing chamber 28, a plasma 40 is generated inside of the processing chamber 28 by supplying RF power from the coil driving circuit 11 to the inductive coil 16. The plasma 40 etches an exposed surface of the substrate 34. A shield 100 according to the present disclosure is arranged within the processing chamber 28 as shown in FIG. 2. The shield 100 contains the plasma 40 and prevents the inner walls and other components in the processing chamber 28 from being damaged by the plasma 40. The shield 100 is shown and described below in detail with reference to FIGS. 2-10. An RF source 50, a pulsing circuit 51 , and a bias matching circuit 52 may be used to bias the substrate support 30 during processing to control ion energy.

[0055] A temperature controller 64 is connected to the heaters 35 and controls the heaters 35 to control a temperature of the substrate support 30 and the substrate 34. The substrate support 30 and the dielectric window 24 include temperature sensors 31 , 25 to sense temperatures of substrate support 30 and the dielectric window 24. The temperature controller 64 communicates with the fluid delivery system 39 to control fluid flow through the cooling system 38 to cool the substrate support 30 based on feedback from the temperature sensor 31. The temperature controller 64 also controls fluid flow though the manifold arranged over the dielectric window 24 to cool the dielectric window 24 based on feedback from the temperature sensor 25.

[0056] An exhaust system 65 includes a valve 66 and pump 67 to control pressure in the processing chamber 28 and / or to remove reactants from the processing chamber 28 by purging or evacuation. A controller 70 (also called system controller) controls the etching process. The controller 70 controls the components of the substrate processing system 10. For example, the controller 70 monitors system parameters and controls delivery of the gas mixture from the gas delivery system 56; striking, maintaining, and extinguishing the plasma 40; removal of reactants from the processing chamber 28; supply of fluid from the fluid delivery system 39; and so on. Additionally, the controller 70 controls various aspects of the coil driving circuit 11 , the RF source 50, the pulsing circuit 51 , and the bias matching circuit 52, and so on.EXAMPLE OF PROCESSING CHAMBER WITH SHIELD

[0057] FIG. 2 shows the processing chamber 28 comprising the shield 100 according to the present disclosure. Elements identified by the same reference numerals that are shown and described with reference to FIG. 1 are not described again for brevity. The processing chamber 28 comprises a sidewall 29. The processing chamber 28 comprises a well 41 disposed within the sidewall 29. For example, the well 41 may be frustoconical as shown or may be cylindrical. The well 41 extends from a top end of the sidewall 29 towards a bottom of the processing chamber 28. For example, a bottom portion of the well 41 extends below a top portion of the substrate support 30 on which the substrate 34 is arranged. The well 41 and the shield 100 enclose a processing volume of the processing chamber 28 in which the substrate 34 is processed.

[0058] The shield 100 is interposed between the dielectric window 24 and a top end of the well 41. Accordingly, the shield 100 extends between the dielectric window 24 and the well 41. For example, the shield 100 extends from the top end of the processing chamber 28 (e.g., from the dielectric window 24) to a midpoint of the processing chamber 28. For example, the midpoint of the processing chamber 28 may be the top end of the well 41 (i.e., the top end of the sidewall 29 of the processing chamber 28) in which the substrate support 30 is disposed in the processing chamber 28. A top end 104 of the shield 100 is attached to the dielectric window 24. A bottom end 106 of the shield 100 is attached to the top end of the well 41. Accordingly, the shield 100 encompasses (surrounds) the processing volume of the processing chamber 28 above the well 41 in which the plasma 40 is generated. The shield 100 contains the plasma 40 used to process the substrate 34 in the processing chamber 28.

[0059] The shield 100 is shown and described below in further detail with reference to FIGS. 3-10. Briefly, the shield 100 is generally cylindrical although the shield 100 can be of any polygonal shape. The shield 100 comprises a body having a sidewall 102, the top end 104, and the bottom end 106. The shield 100 (i.e., the body) comprises a base material that is coated with a coating. The base material comprises a metallic material. For example, the metallic material comprises a metal or an alloy comprising a metal. The coating comprises an anodization layer of a first material deposited on the base material and a plasma spray coating of a second material deposited on the first material. The coating protects the shield 100 from harsh operating conditions in the processing chamber 28 and increases the life and mean time between failures (MTBF) of the shield 100. For example, the harsh operating conditions include harsh chemistries (e.g., halogens), ions and radicals of the plasma 40, harsh thermal environment (e.g., wide ranging temperatures such as 20 C to 300 C) in the processing chamber 28, and thermally induced mechanical stresses (e.g., tensile and / or compressive stresses) in the shield 100. These harsh operating conditions in the processing chamber 28 are collectively called chemical, thermal, and mechanical harshness and generate chemical, thermal, and mechanical stresses on the surface of the coating.

[0060] As shown and described below with reference to FIG. 3 onwards, the shield 100 is annular (i.e., ring shaped). The shield 100 comprises curved portions at the top and bottom ends of the shield 100, which are shown and described below in further detail with reference to FIGS. 8-10. The remainder (i.e., middle portion or sidewall 102) of the shield 100 between the top and bottom ends 104, 106 of the shield 100 is relatively free of curvature (i.e., is relatively straight).

[0061] In other shield designs, the coatings can fail at different locations, particularly near the top and bottom ends 104, 106 of the shield, which comprise curved surfaces. The geometric features at these locations (e.g., the curved surfaces near the top and bottom ends 104, 106 of the shield 100) can greatly influence integrity the coatings.

[0062] As described below in detail, the geometries of the upper and lower portions 104, 106 of shield 100 are designed to improve the coating life by combining convex and concave shapes that induce compressive stresses and reduce coating failures. Specifically, due to the combination of convex and concave shapes at the upper and lower portions 104, 106 of the shield 100, the coating on the shield 100 experienceslower stresses at these regions than in other designs, where the coatings are typically more prone to failure.

[0063] In the shield 100, the stress field gets distributed due to the combination of concave-concave surfaces, which reduces the probability of coating failure in the upper and lower portions 104, 106 of shield 100. Due to the combination of convex and concave shapes at the upper and lower portions of shield 100, lesser strain energy due to the deformation in the coating is stored in the coating in the upper and lower portions 104, 106 of shield 100. Reduced strain energy accumulation in the coating improves the structural integrity of the coating in the upper and lower portions 104, 106 of shield 100.VIEWS OF SHIELD

[0064] FIGS. 3-7 show various views of the shield 100. FIG. 3 shows a perspective view of the shield 100. FIG. 4 shows a top view of the shield 100. FIG. 5 shows a bottom view of the shield 100. FIG. 6 shows a side view of the shield 100. The inner features of the shield 100 are not visible in the side view and are therefore not identified in FIG. 6. FIG. 7 shows a cross-sectional view of the shield 100. The cross-sectional view of the shield 100 shown in FIG. 7 is taken along line A-A is shown in FIG. 5. The shield 100 is described below with reference to FIGS. 3-7.

[0065] In FIGS. 3-7, the shield 100 has a generally cylindrical body comprising the sidewall 102, the first end 104, and the second end 106. The sidewall 102 is cylindrical (i.e., annular or ring-shaped) and has the first end 104 at one rim (e.g., an upper rim or top rim) of the sidewall 102 and the second end 106 at another rim (e.g., a lower rim or bottom rim) of the sidewall 102. As seen in FIG. 2, the sidewall 102 extends vertically parallel to the sidewall 29 of the processing chamber 28. The sidewall 102 of the shield 100 and the sidewall 29 of the processing chamber 28 are parallel to a vertical axis of the processing chamber 28, which is perpendicular to a plane in which the substrate 34 lies on the substrate support 30. Accordingly, the sidewall 102 of the shield 100 is perpendicular to the plane in which the substrate 34 lies on the substrate support 30. Throughout the present disclosure, the first end 104 of the shield 100 is also called the first portion 104, the top end 104, the top portion 104, the upper end 104, or the upper portion 104 of the shield 100. The second end 106 of the shield 100 is also called the second portion 106, the bottom end 106, the bottom portion 106, the lower end 106, or the lower portion 106 of the shield 100.

[0066] The shield 100 is enclosed within the processing chamber 28. For example, the shield 100 is disposed between the dielectric window 24 and the well 41 in the processing chamber 28. The first end 104 of the shield 100 is attached to the dielectric window 24. The second end 106 of the shield 100 is attached to the well 41 . The shield 100 encloses the processing volume in the processing chamber 28 in which the plasma 40 is generated to process the substrate 34 arranged on the substrate support 30. The sidewall 102, the first end 104, and the second end 106 of the shield 100 comprise the base material and the coatings, which are described above. Therefore, the description of the base material and the coatings is not repeated for brevity.

[0067] The first end 104 extends radially outwardly from the sidewall 102. The second end 106 also extends radially outwardly from the sidewall 102. The first end 104 and the second end 106 comprise curved regions that comprise combinations of convex and concave surfaces, which are designed according to the present disclosure to prevent failure of the coating. These curved regions are located in radially inner regions (see FIGS. 8-10) of the first end 104 and the second end 106 where the first end 104 and the second end 106 extend radially outwardly from the sidewall 102. As seen in FIG. 2, these curved features are located in radially inner regions of the first end 104 and the second end 106 near areas of the first end 104 and the second end 106 that contact the dielectric window 24 and the well 41 , respectively. These curved regions located in radially inner regions of the first end 104 and the second end 106 are shown and described below in further detail with reference to FIGS. 8-10.

[0068] The sidewall 102, the first end 104, and the second end 106 also comprise various mounting features (e.g., handles, alignment features, holes that may be threaded or unthreaded, slots for sealing members such as O-rings, etc.) that facilitate or that are used to the attach or mount the shield 100 to the dielectric window 24, the well 41 , and the inner walls of the processing chamber 28. These mounting features can vary depending on the type and design of processing chamber, which determines how and to which components of the processing chamber the shield 100 is to be attached. Further, the coating on these mounting features is less exposed to the harsh environment within the processing chamber 28 and is therefore less prone to failure than the coating on the curved portions of the first end 104 and the second end 106 of the shield 100. Since the mounting features can vary and are less prone to coating failure, the mounting features are not described.GEOMETRY OF SHIELD

[0069] FIGS. 8-10 show examples of the geometrical features of the curved portions of the first end 104 and the second end 106 of the shield 100 that are designed according to the present disclosure. FIG. 8 shows a portion of the cross-section of the shield 100, which is identified in the cross-sectional view of the shield 100 shown in FIG. 7, in further detail. FIGS. 9 and 10 show examples of the geometric features of the first end 104 and the second end 106 of the shield 100 that are designed according to the present disclosure in further detail.

[0070] In FIG. 8, examples of the first end 104 and the second end 106 of the shield 100 that are designed according to the present disclosure are shown in further detail. The radially inner portions of the first end 104 and the second end 106 of the shield 100 comprise combinations of convex and concave surfaces designed according to the present disclosure. These combinations of convex and concave surfaces prevent coating failures in these radially inner portions of the first end 104 and the second end 106 of the shield 100. Examples of the convex and concave surfaces of the radially inner portions of the first end 104 and the second end 106 of the shield 100 are shown and described below in detail with reference to FIGS. 9 and 10.

[0071] FIG. 9 shows an example of the radially inner region of the first end 104 of the shield 100 designed according to the present disclosure. For example, the radially inner region of the first end 104 of the shield 100 comprises a plurality of curved regions (also called a first set of subregions or segments). For example, the first set of subregions of the radially inner region of the first end 104 comprises three curved regions 110, 112, 114. The starting point and the end point of each of the subregions 110, 112, 114 are shown by horizontal dashed lines L1 , L2, L3, L4. The lines L1 , L2, L3, L4 are parallel to the plane of the substrate 34, perpendicular to the sidewall 102 of the shield 100, and perpendicular to the vertical axis of the processing chamber 28. The first subregion 110 lies between lines L1 and L2. The second subregion 112 lies between lines L2 and L3. The third subregion 114 lies between lines L3 and L4.

[0072] In the example shown, the first subregion 110 is convex, the second subregion 112 is concave, and the third subregion 114 is convex. Each of the subregions 110, 112, 114 has a different radius. Since the curvatures convex and concave may depend on viewpoint, a convex curvature is opposite to a concave curvature and vice versa. Accordingly, the first set of subregions of the first end 104 of the shield 100 comprisesat least one subregion having an opposite type of curvature than the rest of the subregions. In addition, while not shown, the first set of subregions of the first end 104 may comprise one or more straight (uncurved) subregions. The straight (uncurved) subregions may be located between two curved regions, at one end of the first set of subregions, at both ends of the first set of subregions, or in any combination thereof.

[0073] While the example shows that the first set of subregions comprises three subregions 110, 112, 114, the first set of subregions can comprise any number of subregions that comprise a combination of convex and concave curved regions. In general, N subregions in the first set of subregions of the first end 104 are defined by and lie between N+1 lines that are parallel to the plane of the substrate 34, perpendicular to the sidewall 102 of the shield 100, and perpendicular to the vertical axis of the processing chamber 28, where N is an integer greater than 1 . In the first set of subregions, the number of subregions, the convex / concave shape of the subregions, and the radii of the subregions can be selected based on the type and design of the processing chamber, which determines how and to which components of the processing chamber the shield 100 is to be attached.

[0074] FIG. 10 shows an example of the radially inner region of the second end 106 of the shield 100 designed according to the present disclosure. For example, the radially inner region of the second end 106 of the shield 100 comprises a plurality of curved regions (also called a second set of subregions or segments). For example, the second set of subregions of the radially inner region of the second end 106 comprises four curved regions 120, 122, 124, 126. The starting point and the end point of each of the subregions 120, 122, 124, 126 are shown by vertical dashed lines L1 , L2, L3, L4, L5. The lines L1 , L2, L3, L4, L5 are perpendicular to the plane of the substrate 34, parallel to the sidewall 102 of the shield 100, and parallel to the vertical axis of the processing chamber 28. The first subregion 120 lies between lines L1 and L2. The second subregion 122 lies between lines L2 and L3. The third subregion 124 lies between lines L3 and L4. The fourth subregion 126 lies between lines L4 and L5.

[0075] In the example shown, the first, second, and third subregions 120, 122, 124 are convex, and the fourth subregion 126 is concave. Each of the subregions 120, 122, 124, 126 has a different radius. Again, since the curvatures convex and concave may depend on viewpoint, a convex curvature is opposite to a concave curvature and vice versa. Accordingly, the second set of subregions of the second end 106 of the shield100 comprises at least one subregion having an opposite type of curvature than the rest of the subregions. In addition, while not shown, the second set of subregions of the second end 106 may comprise one or more straight (uncurved) subregions. The straight (uncurved) subregions may be located between two curved regions, at one end of the first set of subregions, at both ends of the first set of subregions, or in any combination thereof.

[0076] While the example shows that the second set of subregions comprises three subregions 120, 122, 124, 126, the second set of subregions can comprise any number of subregions that comprise a combination of convex and concave curved regions. In general, M subregions in the second set of subregions of the second end 106 are defined by and lie between M+1 lines that are perpendicular to the plane of the substrate 34, parallel to the sidewall 102 of the shield 100, and parallel to the vertical axis of the processing chamber 28, where M is an integer greater than 1 , and where M may be equal to or different than N. In the second set of subregions, the number of subregions, the convex / concave shape of the subregions, and the radii of the subregions can be selected based on the type and design of the processing chamber, which determines how and to which components of the processing chamber the shield 100 is to be attached.

[0077] Employing a combination of convex and concave surfaces near the top and bottom ends 104, 106 of the shield 100 as described above prevents the failure of the coating near the top and bottom ends 104, 106 of the shield 100. The combination of convex and concave surfaces near the top and bottom ends 104, 106 of the shield 100 enhances the structural integrity of the coating and prevents failure of the coating at these locations. Preventing failure of the coating at these locations in turn reduces or eliminates particle contamination of the processing chamber.

[0078] Modifying the geometry of the surfaces of the shield 100 at the particular locations of the shield 100 as described above reduces the stresses in the coating at the particular locations of the shield 100 (e.g., near the top and bottom ends 104, 106 of the shield 100). Modifying the geometry of the surfaces of the shield 100 at the particular locations of the shield 100 also induces compressive stresses at the particular locations of the shield 100 (e.g., near the top and bottom ends 104, 106 of the shield 100). The compressive stresses reduce crack generation and crack propagation in the coating at the particular locations of the shield 100 (e.g., near the top and bottomends 104, 106 of the shield 100). Adopting the concave-convex surface combination near the top and bottom ends 104, 106 of the shield 100 reduces the thermal and mechanical stresses on the coating at the particular locations of the shield 100 (e.g., near the top and bottom ends 104, 106 of the shield 100). The combination of concave and convex surfaces lowers strain energy accumulation in the coating near the top and bottom ends 104, 106 of the shield 100. Reduced strain energy accumulation in the coating improves the structural integrity of the coating at the particular locations of the shield 100 (e.g., near the top and bottom ends 104, 106 of the shield 100). The combination of concave and convex surfaces near the top and bottom ends 104, 106 of the shield 100 compensates for mismatch between coefficients of thermal expansion (CTEs) of the base material of the shield 100 and materials of the coating.

[0079] Thus, the design of the shield 100 described above improves life of the coating on the shield 100, improves mean time between failures (MTBF) of the shield 100, reduces particle contamination in the processing chamber, increases operating duty cycles for the components of the processing chamber, reduces system downtime, and improves yield.

[0080] The foregoing description is merely illustrative in nature and is not intended to limit the disclosure, its application, or uses. The broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent upon a study of the drawings, the specification, and the following claims.

[0081] It should be understood that one or more steps within a method may be executed in different order (or concurrently) without altering the principles of the present disclosure. Further, although each of the examples is described above as having certain features, any one or more of those features described with respect to any one of the examples of the disclosure can be implemented in and / or combined with features of any of the other examples, even if that combination is not explicitly described. In other words, the described examples are not mutually exclusive, and permutations of one or more examples with one another remain within the scope of this disclosure.

[0082] Spatial and functional relationships between elements (for example, between modules, circuit elements, semiconductor layers, etc.) are described using various terms, including “connected,” “engaged,” “coupled,” “adjacent,” “next to,” “on top of,”“above,” “below,” and “disposed.” Unless explicitly described as being “direct,” when a relationship between first and second elements is described in the above disclosure, that relationship can be a direct relationship where no other intervening elements are present between the first and second elements, but can also be an indirect relationship where one or more intervening elements are present (either spatially or functionally) between the first and second elements. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A OR B OR C), using a non-exclusive logical OR, and should not be construed to mean “at least one of A, at least one of B, and at least one of C.”

[0083] In some implementations, a controller is part of a system, which may be part of the above-described examples. Such systems can comprise semiconductor processing equipment, including a processing tool or tools, chamber or chambers, a platform or platforms for processing, and / or specific processing components (a substrate support, a gas flow system, etc.). These systems may be integrated with electronics for controlling their operation before, during, and after processing of a semiconductor wafer or substrate.

[0084] The electronics may be referred to as the “controller,” which may control various components or subparts of the system or systems. The controller, depending on the processing requirements and / or the type of system, may be programmed to control any of the processes disclosed herein, including the delivery of processing gases, temperature settings (e.g., heating and / or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow rate settings, fluid delivery settings, positional and operation settings, wafer transfers into and out of a tool and other transfer tools and / or load locks connected to or interfaced with a specific system.

[0085] Broadly speaking, the controller may be defined as electronics having various integrated circuits, logic, memory, and / or software that receive instructions, issue instructions, control operation, enable cleaning operations, enable endpoint measurements, and the like. The integrated circuits may include chips in the form of firmware that store program instructions, digital signal processors (DSPs), chips defined as application specific integrated circuits (ASICs), and / or one or more microprocessors, or microcontrollers that execute program instructions (e.g., software).

[0086] Program instructions may be instructions communicated to the controller in the form of various individual settings (or program files), defining operational parameters for carrying out a particular process on or for a semiconductor wafer or to a system. The operational parameters may, in some examples, be part of a recipe defined by process engineers to accomplish one or more processing steps during the fabrication of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or dies of a wafer.

[0087] The controller, in some implementations, may be a part of or coupled to a computer that is integrated with the system, coupled to the system, otherwise networked to the system, or a combination thereof. For example, the controller may be in the “cloud” or all or a part of a fab host computer system, which can allow for remote access of the wafer processing. The computer may enable remote access to the system to monitor current progress of fabrication operations, examine a history of past fabrication operations, examine trends or performance metrics from a plurality of fabrication operations, to change parameters of current processing, to set processing steps to follow a current processing, or to start a new process.

[0088] In some examples, a remote computer (e.g., a server) can provide process recipes to a system over a network, which may include a local network or the Internet. The remote computer may include a user interface that enables entry or programming of parameters and / or settings, which are then communicated to the system from the remote computer. In some examples, the controller receives instructions in the form of data, which specify parameters for each of the processing steps to be performed during one or more operations. It should be understood that the parameters may be specific to the type of process to be performed and the type of tool that the controller is configured to interface with or control.

[0089] Thus, as described above, the controller may be distributed, such as by comprising one or more discrete controllers that are networked together and working towards a common purpose, such as the processes and controls described herein. An example of a distributed controller for such purposes would be one or more integrated circuits on a chamber in communication with one or more integrated circuits located remotely (such as at the platform level or as part of a remote computer) that combine to control a process on the chamber.

[0090] Without limitation, example systems may include a plasma etch chamber or module, a deposition chamber or module, a spin-rinse chamber or module, a metal plating chamber or module, a clean chamber or module, a bevel edge etch chamber or module, a physical vapor deposition (PVD) chamber or module, a chemical vapor deposition (CVD) chamber or module, an atomic layer deposition (ALD) chamber or module, an atomic layer etch (ALE) chamber or module, an ion implantation chamber or module, a track chamber or module, and any other semiconductor processing systems that may be associated or used in the fabrication and / or manufacturing of semiconductor wafers.

[0091] As noted above, depending on the process step or steps to be performed by the tool, the controller might communicate with one or more of other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, neighboring tools, tools located throughout a factory, a main computer, another controller, or tools used in material transport that bring containers of wafers to and from tool locations and / or load ports in a semiconductor manufacturing factory.

Claims

CLAIMSWhat is claimed is:1 . A shield for a processing chamber comprising: a body comprising a sidewall, a first end, and a second end, wherein the sidewall surrounds a processing volume in the processing chamber, and wherein the first end and the second end are attached to respective components of the processing chamber; and a first set of curved regions at the first end, wherein at least one curved region in the first set of curved regions has an opposite curvature than rest of the curved regions in the first set of curved regions.

2. The shield of claim 1 further comprising a second set of curved regions at the second end, wherein at least one curved region in the second set of curved regions has an opposite curvature than rest of the curved regions in the second set of curved regions.

3. The shield of claim 1 wherein the first set of curved regions comprises convex and concave regions.

4. The shield of claim 2 wherein the second set of curved regions comprises convex and concave regions.

5. The shield of claim 1 wherein at least one curved region in the first set of curved regions has a different radius than rest of the curved regions in the first set of curved regions.

6. The shield of claim 2 wherein at least one curved region in the second set of curved regions has a different radius than rest of the curved regions in the first set of curved regions.

7. The shield of claim 1 wherein the first set of curved regions is located at a radially inner portion of the first end.

8. The shield of claim 2 wherein the second set of curved regions is located at a radially inner portion of the second end.

9. The shield of claim 1 wherein the body comprises a metallic material and a coating and wherein the coating comprises an anodization layer of a first material deposited on the metallic material and plasma spray coating of a second material deposited on the first material.

10. The shield of claim 1 wherein the body is coated with a coating material and wherein the first set of curved regions induce compressive stresses in the coating material.11 . The shield of claim 2 wherein the body is coated with a coating material and wherein the second set of curved regions induce compressive stresses in the coating material.

12. The shield of claim 1 wherein the body comprises a base material coated with a coating material and wherein the first set of curved regions compensates for mismatch between coefficients of thermal expansion (CTEs) of the base material and the coating material.

13. The shield of claim 2 wherein the body comprises a base material coated with a coating material and wherein the second set of curved regions compensates for mismatch between coefficients of thermal expansion (CTEs) of the base material and the coating material.

14. The shield of claim 1 wherein the body is coated with a coating material that withstands chemical, thermal, and mechanical stresses in the processing chamber due to tensile residual or tensile stresses induced in the coating material by the first set of curved regions.

15. The shield of claim 2 wherein the body is coated with a coating material that withstands chemical, thermal, and mechanical stresses in the processing chamber due to tensile residual or tensile stresses induced in the coating material by the second set of curved regions.

16. A shield for a processing chamber comprising: a body comprising a sidewall, a first end, and a second end, wherein the sidewall surrounds a processing volume in the processing chamber, and wherein the first end and the second end are attached to respective components of the processing chamber; a first set of curved regions at the first end, wherein the first set of curved regions comprises convex and concave regions; and a second set of curved regions at the second end, wherein the second set of curved regions comprises convex and concave regions.

17. The shield of claim 16 wherein the first set of curved regions is located at a radially inner portion of the first end, and wherein the second set of curved regions is located at a radially inner portion of the second end.

18. The shield of claim 16 wherein at least one curved region in the first set of curved regions has a different radius than rest of the curved regions in the first set of curved regions and wherein at least one curved region in the second set of curved regions has a different radius than rest of the curved regions in the first set of curved regions.

19. The shield of claim 16 wherein the body comprises a metallic material and a coating and wherein the coating comprises an anodization layer of a first material deposited on the metallic material and plasma spray coating of a second material deposited on the first material.

20. The shield of claim 16 wherein the body is coated with a coating material and wherein the first and second sets of curved regions induce thermal residual stresses in the coating material.21 . The shield of claim 16 wherein the body comprises a base material coated with a coating material and wherein the first and second sets of curved regions compensate for mismatch between coefficients of thermal expansion (CTEs) of the base material and the coating material.

22. The shield of claim 16 wherein the body is coated with a ceramic or metal oxide coating material that withstands chemical, thermal, and mechanical stresses in the processing chamber due to tensile residual or tensile stresses induced in the coating material by the first and second sets of curved regions.

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