Shaped silicon outer top electrode for plasma processing

Abstract

An outer upper electrode for plasma processing has a shaped bottom surface and a top surface having a radial width, the middle portion of the top surface having an elliptical shape. A cylindrical outer shape traverses the height of the outer upper electrode, and the middle portion of the top surface defines an upper portion of the cylindrical outer shape. An inner diameter surface connects the top surface to the shaped bottom surface, and the inner diameter surface includes a transition edge. The outer diameter surface connects the top surface to the shaped bottom surface. A convex protrusion of the shaped bottom surface protrudes below the transition edge of the inner diameter surface and includes a microprotrusion located in an interior region of the cylindrical outer shape.

Description

[Technical Field]

[0001] The present embodiments relate to semiconductor manufacturing, and more particularly to systems and methods for implementing a shaped outer upper electrode with a specific curvature to modify plasma density and tailor wafer performance. [Background technology]

[0002] Many current semiconductor chip manufacturing processes, such as plasma etching processes, are performed in a plasma processing chamber in which a substrate (e.g., a wafer) is supported on an electrostatic chuck (ESC). In a plasma etching process, the wafer is exposed to a plasma generated in the plasma processing space. The plasma contains various types of radicals, electrons, and positive and negative ions. Chemical reactions of the various radicals, electrons, positive ions, and negative ions are used to etch features, surfaces, and materials on the wafer.

[0003] For example, when a process gas is supplied to a plasma processing chamber, a radio frequency (RF) signal provides power and is applied to at least one of the electrodes of the plasma processing chamber to form an electric field between the electrodes. The RF signal causes the process gas to become a plasma, thereby performing plasma etching on a predetermined layer disposed on a wafer. Unfortunately, during wafer processing, the plasma formation can cause non-uniform features along the edge of the wafer, thereby adversely affecting wafer performance during manufacturing.

[0004] Thus, embodiments of the present disclosure have arisen. Summary of the Invention

[0005] The present embodiment relates to a method and apparatus for a shaped outer upper electrode with a specific curvature to modify plasma density and adjust wafer performance. Several inventive embodiments of the present disclosure are described below.

[0006] An embodiment of the present disclosure provides an outer upper electrode for use in plasma processing. The outer upper electrode includes a shaped bottom surface. The outer upper electrode includes a top surface having a radial width, and an intermediate portion of the top surface has an elliptical shape. The outer upper electrode has a cylindrical outer shape across its height, and the intermediate portion of the top surface defines an upper portion of the cylindrical outer shape. The outer upper electrode includes an inner diameter surface connecting the top surface and the shaped bottom surface, and the inner diameter surface includes a transition edge. The outer upper electrode includes an outer diameter surface connecting the top surface and the shaped bottom surface. The outer upper electrode includes a convex protrusion of the shaped bottom surface that protrudes below the transition edge of the inner diameter surface, and the convex protrusion includes a microprotrusion located in an interior region of the cylindrical outer shape.

[0007] Another embodiment of the present disclosure provides an upper electrode for use in plasma processing. The upper electrode includes an inner upper electrode having a disk shape, including a first top surface and a bottom surface joined by an outer surface. The bottom surface includes a sloped bottom surface extending from a lower end of the outer surface to a central projection. The upper electrode includes an outer upper electrode adjacent to the inner upper electrode. The outer upper electrode includes a shaped bottom surface. The outer upper electrode includes a second top surface having a radial width, and an intermediate portion of the second top surface has an elliptical shape. The outer upper electrode has a cylindrical outer shape across the height of the outer upper electrode, and the intermediate portion of the second top surface defines an upper portion of the cylindrical outer shape. The outer upper electrode includes an inner diameter surface joining the second top surface and the shaped bottom surface, and the inner diameter surface includes a transition edge. The outer upper electrode includes an outer diameter surface joining the second top surface and the shaped bottom surface. The outer upper electrode includes a shaped bottom convex protrusion that protrudes below the transition edge of the inner diameter surface, the convex protrusion including a micro-protrusion located in the interior region of the cylindrical outer shape.

[0008] Yet another embodiment of the present disclosure provides a processing chamber configured for plasma processing. The processing chamber includes a pedestal assembly for supporting a substrate. The processing chamber includes an inner upper electrode, the inner upper electrode having a disk shape including a first top surface and a bottom surface joined by an outer surface, facing the pedestal assembly. The bottom surface includes a sloped bottom surface extending from a lower end of the outer surface to a central protrusion. The processing chamber includes an outer upper electrode adjacent to the inner upper electrode. The outer upper electrode includes a shaped bottom surface. The outer upper electrode includes a second top surface having a radial width, and an intermediate portion of the second top surface has an elliptical shape. The outer upper electrode has a cylindrical outer shape across its height, and the intermediate portion of the second top surface defines an upper portion of the cylindrical shape. The outer upper electrode includes an inner diameter surface connecting the second top surface and the shaped bottom surface, the inner diameter surface including a transition edge. The outer upper electrode includes an outer diameter surface connecting the second top surface and the shaped bottom surface. The outer upper electrode includes a shaped bottom convex protrusion that protrudes below the transition end of the inner diameter surface, and the convex protrusion includes a micro-protrusion located in an inner region of the cylindrical outer shape. The outer upper electrode is an annular ring.

[0009] These and other advantages will be recognized by those of ordinary skill in the art upon reading the entire specification and claims. [Brief explanation of the drawings]

[0010] The embodiments will be better understood with reference to the following description taken in conjunction with the accompanying drawings.

[0011] [Figure 1] 1 illustrates an embodiment of a capacitively coupled plasma (CCP) processing system used for etching operations, according to an embodiment of the present disclosure.

[0012] [Figure 2] 1A-1C illustrate how the shape of the inner and outer top electrodes affects wafer performance during plasma processing, according to an embodiment of the present disclosure.

[0013] [Figure 3A]FIG. 1B is a top view of an outer upper electrode shaped with a specific curvature to modify plasma density to adjust wafer performance during wafer fabrication, according to one embodiment of the present disclosure.

[0014] [Figure 3B] 3B is a cross-sectional view of the outer top electrode shown in FIG. 3A shaped with a specific curvature to modify plasma density and adjust wafer performance during wafer fabrication, according to one embodiment of the present disclosure.

[0015] [Figure 3C] 3B is another cross-sectional view of the outer top electrode shown in FIG. 3A, including various exemplary configurations or modifications of recesses formed in the molded bottom surface, according to an embodiment of the present disclosure.

[0016] [Figure 3D] 3B is another cross-sectional view of the outer top electrode shown in FIG. 3A, illustrating another example configuration or modification of the protrusions formed on the molded bottom surface, according to one embodiment of the present disclosure.

[0017] [Figure 4] 1B is a diagram illustrating the boundary between an inner top electrode with a sloped bottom surface and an outer top electrode with a shaped bottom surface, according to one embodiment of the present disclosure.

[0018] [Figure 5A] 5A-5C illustrate various offsets of an outer top electrode with a shaped bottom surface relative to an inner top electrode with a sloped bottom surface at the boundary shown in FIG. 4 according to one embodiment of the present disclosure. [Figure 5B] 5A-5C illustrate various offsets of an outer top electrode with a shaped bottom surface relative to an inner top electrode with a sloped bottom surface at the boundary shown in FIG. 4 according to one embodiment of the present disclosure. [Figure 5C] 5A-5C illustrate various offsets of an outer top electrode with a shaped bottom surface relative to an inner top electrode with a sloped bottom surface at the boundary shown in FIG. 4 according to one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0019] Although the following detailed description includes some specific details for purposes of explanation, one of ordinary skill in the art will recognize that some variations on the following details are within the scope of the present disclosure. Accordingly, the aspects of the present disclosure described below are set forth without loss of generality to, and without imposing limitations on, the claims that follow.

[0020] In general, various embodiments of the present disclosure describe methods and apparatus for a shaped outer top electrode having a specific curvature to modify plasma density and adjust wafer performance. In particular, the outer top electrode includes one or more curved regions to achieve managed plasma density control over the wafer during processing. That is, the outer top electrode includes a shaped bottom surface with a gradual transition rather than an abrupt transition (e.g., a sharp tip). In some embodiments, the outer top electrode includes a shaped bottom surface that is an extension or continuation of the sloped bottom surface of the inner top electrode.

[0021] Advantages of various embodiments disclosing methods and apparatus for a shaped outer top electrode include managed plasma density control over a portion of a wafer. The ability to tailor plasma density over the wafer provides improved performance at the edge of the substrate. For example, shaping the outer top electrode allows for tailoring of plasma density across the substrate, achieving a uniform etch rate across the diameter of the wafer extending toward the outer edge. This improves the yield of each wafer (i.e., semiconductor chips).

[0022] In conjunction with the above general understanding of various embodiments, illustrative details of the embodiments will now be described with reference to various drawing figures. Elements and / or parts with the same numerals in one or more figures are generally intended to have the same structure and / or function. Moreover, the figures are not drawn to scale, but are intended to illustrate and emphasize novel concepts. It will be apparent that the present embodiments may be practiced without some or all of these specific details. In other instances, well-known process operations have not been described in detail so as not to unnecessarily obscure the present embodiments.

[0023] FIG. 1 illustrates an exemplary embodiment of a plasma processing system 100 for use in operations including film etching and / or deposition, in accordance with one embodiment of the present disclosure. The plasma processing system 100 is configured to process a substrate or wafer 120, for example, by performing plasma processing on the substrate 120. By way of example, the plasma processing system 100 illustrated in FIG. 1 may be used for etching operations and is configured as a capacitively coupled plasma (CCP) processing system. However, in other embodiments, the plasma processing system 100 may be modified to generate plasma by various methods (e.g., inductively coupled plasma (ICP), etc.) depending on the design. That is, embodiments of the present disclosure that include a shaped outer upper electrode with a specific curvature to modify plasma density and tailor wafer performance may be implemented for various plasma processing systems (e.g., CCP, ICP, etc.) and their respective configuration variations.

[0024] FIG. 1 illustrates an exemplary embodiment of a plasma processing system 100 used for etching operations, configured as a CCP processing system and including a CCP plasma processing chamber 102. The plasma processing chamber 102 includes a substrate support or substrate pedestal (e.g., an electrostatic chuck (ESC) 118 or a magnetic chuck). In an embodiment, the ESC may have several circular rings containing different types of materials to achieve a certain capacitive coupling between the ESC and an optional edge ring 126. A bottom electrode 122 may be embedded within the ESC 118. A substrate 120 may be placed on the pedestal for processing and processed to create one or more semiconductor chips. Facing the pedestal is an upper electrode, which may be configured as an inner upper electrode 124 and an outer upper electrode 123. As shown, the inner upper electrode 124 may be grounded. In other embodiments, the inner upper electrode 124 may be connected to an RF power source (e.g., to provide radio frequency power). In some embodiments, the inner top electrode 124 may be shaped to have a sloped bottom surface to tailor the plasma density across the diameter of the substrate 120. The inner top electrode 124 may be configured with an extension (e.g., the outer top electrode 123) that may be shaped as a ring. In some embodiments, the outer top electrode 123 may be grounded. Between the top electrodes (i.e., the inner top electrode 124 and the outer top electrode 123) and the bottom electrode 122, there is a gap that forms a process space in which the plasma 130 may form.

[0025] Specifically, the outer upper electrode 123 surrounds the inner upper electrode 124. Note that the outer upper electrode 123 has an annular body (e.g., a circular body, a ring-shaped body, or a dish-shaped body). In an embodiment, the outer upper electrode 123 is shaped to adjust the plasma density of the plasma 130 across the substrate 120 to achieve a uniform etch rate, particularly toward the outer edge of the substrate 120. For example, an enhanced plasma density may be achieved in a region 131 of the plasma 130. The region 131 may be a ring located below the outer upper electrode 123. Similarly, an enhanced plasma density may be achieved in a region 132 of the plasma 130 due to a protrusion in the central region of the inner upper electrode 124.

[0026] As shown, the plasma processing chamber 102 of FIG. 1 may include a C-shroud 150 extending from the top electrodes (e.g., inner top electrode 124 and outer top electrode 123) to the ESC 118, including the bottom electrode, to provide further plasma containment. The C-shroud may have multiple openings to allow gases and byproducts to flow out of the C-shroud. The C-shroud may be grounded. In other embodiments, the plasma processing chamber may be configured differently, including with confinement rings (not shown) to confine the plasma 130 during etching operations.

[0027] In another embodiment, a gas source 114 is connected to the plasma processing chamber 102 and configured to inject a desired process gas into the plasma processing chamber 102. As an example of plasma formation, after providing one or more RF signals to the ESCs 118 and injecting a process gas into the plasma processing chamber 102, a plasma 130 is formed between the upper electrode 124 and the ESCs 118. The plasma 130 may be used to etch the surface of the wafer 120.

[0028] The source radio frequency (RF) power supply 110 is configured to provide RF power for plasma generation. The RF power supply 110 is connected to an impedance matching network 106, which is further connected to the bottom electrode 122. The impedance matching network matches the impedance between a load (e.g., the plasma chamber 102 and any connecting cables) and a source (e.g., the source RF power supply and any connecting cables). That is, the matching network enables dynamic tuning of the power provided to the bottom electrode 122 by matching the impedance between the load and the source. The source RF power supply 110 is typically used to generate the plasma 130 using a process gas delivered from the gas source 114. For example, the RF power supply 110 may be a high frequency (HF) RF generator configured to generate a high frequency in the range of 13 megahertz (MHz) to 120 MHz, inclusive. For example, the frequency may be 13 MHz to 120 MHz, inclusive. For example, the radio frequency may have a baseline frequency of 13.56 MHz, or 27 MHz, or 40 MHz, or 60 MHz, or 100 MHz. In embodiments, depending on the configuration of plasma processing system 100, various configurations of power delivery may be implemented, including providing RF power using one or more signals at one or more frequencies delivered to the upper electrode and / or the lower electrode, and providing a bias voltage to the lower electrode. The RF power and / or bias power may be pulsed or continuous.

[0029] In embodiments, the system may include a controller 116 that is used to control various components of the plasma processing system 100. In one example, the controller 116 may be connected to the RF power source 110, the gas source 114 connected to the plasma processing chamber 102, and other components. The controller 116 includes a processor, memory, software logic, hardware logic, and input / output subsystems for communicating with, and monitoring and controlling, the plasma processing system 100. In some embodiments, the controller 116 includes one or more recipes including multiple set points and various operating parameters (e.g., voltage, current, frequency, pressure, flow rate, power level, temperature, timing parameters, process gases, mechanical motion of the substrate 120, etc.) for operating the plasma processing system 100. For example, the controller 116 controls the delivery of process gases delivered from the gas source 114 to achieve intended process conditions, such as etching features and / or depositing or forming a film on the substrate 120, depending on the process being performed. The selected gas is then distributed into the spatial volume defined between the upper electrode 124 and the substrate 120 on the ESC 118 .

[0030] FIG. 2 illustrates how the shape of the inner and outer top electrodes affects wafer performance during plasma processing, according to an embodiment of the present disclosure. In particular, three graphs (e.g., 200A, 200B, and 200C) show etch rates across a corresponding substrate (not shown) for various configurations of the inner and / or outer top electrodes. For illustrative purposes only, the substrate may have a diameter of 300 millimeters (mm) and a corresponding radius of 150 mm. It is understood that embodiments of the present disclosure can be implemented for wafers of any size with appropriate modifications to the inner and outer top electrodes (e.g., resizing either or both of the inner and outer top electrodes). An embodiment of the present disclosure includes a shaped outer top electrode configured to modify plasma density (to achieve a uniform etch rate across the surface of the wafer) to tailor wafer performance.

[0031] The three graphs (e.g., 200A, 200B, and 200C) are aligned for comparison purposes and share a centerline 250 (e.g., the center of the substrate), an outer diameter indicated by lines 255A and 255B, and a radial region of the substrate having an inner diameter indicated by lines 257A and 257B. In embodiments, centerline 250 may correspond to the centerline of each of the inner top electrodes (e.g., 124A and 124B) and / or each of the outer top electrodes (e.g., 123A and 123B). The outer radial region may be referred to as the edge of the substrate, and while edges typically have a lower etch rate, implementing the shaped outer top electrodes of this embodiment may exhibit a higher and more uniform etch rate (e.g., when compared to the etch rate of the central region of the substrate). Specifically, the outer radius region may be defined as a ring, shown on the left side of graph 200A between lines 255A and 257A, and on the right side of graph 200A between lines 255B and 257B. For example, the outer radius region may include the outer 20-30 mm of the substrate (e.g., a 300 mm substrate with a 150 mm radius, or a substrate of a different diameter). In embodiments, the inner radius of the shaped upper outer electrode 123B may begin at a small radius that is within the outer radius of the substrate, or may begin at a large radius that exceeds the outer radius of the substrate.

[0032] For example, graph 200A shows the etch rate across the substrate for an unmodified top electrode. That is, inner top electrode 124A is unshaped and has a flat, plasma-facing bottom surface. Outer top electrode 123A is also unshaped and has a similarly flat, plasma-facing bottom surface. In some embodiments, the bottom surfaces of inner top electrode 124A and outer top electrode 123A are coplanar. Vertical line 240A shows the relative etch rate across one or more radii for a corresponding radius (e.g., 0-150 mm for a 300 mm substrate), while horizontal line 245A shows different radii for a corresponding radius of the substrate. In particular, line 210 shows the etch rate across the diameter of the substrate for an unshaped inner top electrode and for an unshaped outer top electrode. The etch rate shown by line 210 is symmetrical about centerline 250, indicating a relatively constant etch rate in the central region of the substrate (e.g., a radius of about 50-65 mm from the center of the substrate). A high etch rate is indicated by humps 211A and 211B (radius range of approximately 65-130 mm). The etch rate indicated by line 210 decreases significantly to zero (0) at the edge (i.e., radius range of approximately 130-150 mm) so that it is extremely low at the outer radius region of the substrate. It is desirable to have a uniform etch rate across the radius of the substrate, which can be achieved in embodiments by shaped inner and outer top electrodes.

[0033] Graph 200B shows the etch rate across the substrate for a partially modified top electrode. That is, the inner top electrode 124B is shaped and includes a shaped, sloped bottom surface facing the plasma. The sloped bottom surface is configured to adjust the plasma density in the central region of the substrate to achieve a uniform etch rate across the substrate (particularly in the central region). In particular, the sloped bottom surface may include a central protrusion that can increase the plasma density above the central region of the substrate. In some embodiments, the thickness of the central protrusion of the inner top electrode 124B along line 250 is greater than the thickness of the central region of the inner top electrode 124A along line 250. For example, the central protrusion of the inner top electrode 124B may intentionally extend toward the substrate to increase the plasma density above the central region of the substrate to a desired level (e.g., increase the etch rate). Meanwhile, the outer top electrode 123A is unshaped and includes a similar flat, plasma-facing bottom surface (i.e., similar to that shown in graph 200A). For illustrative purposes, the central protrusion of the inner top electrode 124B may extend below the bottom surface of the outer top electrode 123A.

[0034] Vertical line 240B shows the relative etch rate across one or more corresponding radial radii (e.g., 0-150 mm for a 300 mm substrate), while horizontal line 245B shows different corresponding radial radii for the substrate. In particular, line 220 shows the etch rate across the diameter of the substrate for a shaped inner top electrode and an unshaped outer top electrode. Graph 200B compares the etch rate between line 220 and line 210. Notably, the etch rate shown by line 220 is symmetrical about centerline 250, indicating a relatively constant etch rate across the majority of the substrate (e.g., between radii of approximately 0 and 120 degrees). That is, the bottom surface of the inner upper electrode is shaped (e.g., a central protrusion) to increase plasma density in the central region of the substrate (e.g., a radius of approximately 50-65 mm from the center of the substrate) and shaped (e.g., sloped at the outer diameter) to reduce plasma density in the region corresponding to humps 211A and 211B in graph 200A (e.g., a radius of approximately 65-130 mm from the substrate). While not wishing to be bound by theory or mechanism of action, the shape and distance of selected regions of the bottom surface of the (inner or outer) upper electrode are believed to affect the plasma density of the plasma formed above the substrate. For example, plasma density will increase as the distance between the bottom surface of the upper electrode and the substrate decreases. Similarly, plasma density will decrease as the distance between the bottom surface of the upper electrode and the substrate increases.

[0035] Thus, comparing graph 200B with graph 200A, the shaped inner top electrode 124B exhibits an increased etch rate in the central region of the substrate and a decreased etch rate at a radius of about 65-130 mm of the substrate (e.g., corresponding to humps 211A and 211B in graph 200A). For example, the etch rate across most of the substrate (e.g., from a radius of about 0-120 degrees) as indicated by line 220 will be higher than the etch rate across the central region of the substrate (e.g., from a radius of about 0 to 50-65 degrees) as indicated by line 210. Also, the etch rate across line 220 from a radius of about 0 to 50-65 degrees (e.g., previously corresponding to humps 211A and 211B with respect to graph 200A) will be lower than the corresponding etch rate indicated by line 210. In this manner, a relatively constant etch rate is achieved between a radius of about 0 and 120 degrees, as indicated by line 220 in graph 200B. Furthermore, because outer top electrode 123A is not shaped, the etch rate shown by line 220 decreases significantly to zero (0) at the edge (i.e., in the 130-150 mm radius range) so that it is extremely low at the outer radius region of the substrate. This etch rate may be similar to the etch rate shown by line 210 in graph 200A. It is desirable to have a uniform etch rate across the radius of the substrate, especially towards the outer region of the substrate, which may be achieved by the shaped inner and outer top electrodes shown in the embodiment and graph 200C.

[0036] Graph 200C shows the etch rate across the substrate for the modified top electrode. In particular, the inner top electrode 124B is shaped and includes a shaped, sloped bottom surface facing the plasma. The sloped bottom surface is configured to adjust the plasma density in the central region of the substrate to achieve a uniform etch rate across the substrate (particularly in the central region). For example, the sloped bottom surface may include a central protrusion that can increase the plasma density of the plasma above the central region of the substrate. The inner top electrode 124B was fully described in connection with graph 200B. The outer top electrode 123B is also shaped and includes a similarly shaped, plasma-facing bottom surface. The shaped bottom surface is configured to adjust (e.g., generally increase) the plasma density in the outer regions (e.g., edges) of the substrate. For example, the shaped bottom surface includes one or more of a convex protrusion, a concave portion adjacent to the convex protrusion, and / or an extension adjacent to the concave portion. For purposes of illustration, in one embodiment, the bottom of the central protrusion of the inner top electrode 124B may be aligned with the bottom of the convex protrusion (e.g., tiny protrusion) of the outer top electrode 123B. A more detailed description of the shaped outer top electrode 123B is provided in Figures 3A-3D and 4.

[0037] Vertical line 240C shows the relative etch rate across one or more radii (e.g., 0-150 mm for a 300 mm substrate) for the corresponding radial distance, while horizontal line 245B shows different radii for the corresponding radial distance of the substrate. In particular, line 230 shows the etch rate across the diameter of the substrate for a shaped inner top electrode and a shaped outer top electrode. Graph 200C compares the etch rate between line 230 and line 210 (of graph 200A, which corresponds to an unshaped top electrode). Notably, the etch rate shown by line 230 is symmetrical about line 250, indicating a relatively constant etch rate across the entire substrate (e.g., between radii of 0 and 140-150 degrees), particularly out to the edge of the substrate. At the outer edge of the substrate (e.g., near 150 mm), there is a significant decrease in etch rate. In particular, as previously described, the bottom surface of inner upper electrode 124B is shaped to increase plasma density in the central region of the substrate (e.g., approximately a 50-65 mm radius from the center of the substrate) and is also shaped (sloped at the outer diameter) to decrease plasma density in the region corresponding to humps 211A and 211B in graph 200A (e.g., approximately a 65-130 mm radius range of the substrate). Additionally, the shaped bottom surface of outer upper electrode 123B is shaped to increase plasma density at the edge toward the outer diameter. As previously described, without wishing to be bound by theory or mechanism of action, it is believed that the shape and distance of selected regions of the bottom surface of the (inner or outer) upper electrode can be designed to adjust the plasma density of the plasma formed above the substrate.

[0038] Thus, comparing graph 200C with graph 200A, as previously discussed when comparing graph 200B with graph 200A over the same region, the shaped inner top electrode 124B increases the etch rate in the central region of the substrate and decreases the etch rate for a radius of the substrate between about 65 and 130 mm (e.g., corresponding to humps 211A and 211B in graph 200A). Additionally, because outer top electrode 12B is shaped (e.g., includes a shaped bottom surface), the etch rate at the edges (e.g., between about 130 and 150 mm) in graph 200C is significantly increased from the etch rate in graph 200A. Thus, as shown by line 230 in graph 200C, a relatively constant etch rate is achieved throughout the substrate (e.g., between a radius of about 0 and 150 mm), with a sharp decrease in etch rate only near the outer edge of the substrate (e.g., near 150 mm). Therefore, the combination of a shaped inner top electrode and a shaped outer top electrode provides a uniform etch rate across the radius of the substrate, particularly towards the outer edge and / or outer diameter of the substrate, as shown in graph 200C.

[0039] 3A-3B illustrate the exemplary shaped outer top electrode 123B shown in FIG. 2, including a shaped bottom surface for modifying and / or controlling plasma density above the substrate to tailor wafer performance during processing. FIG. 3B illustrates a cross-section of the outer top electrode 123B taken along line ZZ shown in FIG. 3A, where the outer top electrode 123B is shaped with a specific curvature to modify plasma density and tailor wafer performance during wafer fabrication, according to one embodiment of the present disclosure. It is contemplated that the dimensions shown in FIGS. 3A-3B can be varied with values ​​selected for the dimensions based on design.

[0040] In particular, the outer upper electrode 123B is configured as an annular ring. The outer upper electrode has an upper surface 305. The upper surface 305 has a radial width defined by a selectable dimension "B." In embodiments, the dimension "B" may have a value between 10 mm and 20 mm, or between 20 mm and 30 mm, or between 30 mm and 40 mm, or between 40 mm and 50 mm, or between 50 mm and 60 mm, or between 60 mm and 70 mm. The upper surface 305 has an intermediate portion 365, which may be elliptical and / or circular, located between the inner and outer radial surfaces 320 and 310 of the outer upper electrode 123B. In embodiments, the radius of the inner radial surface 320 is selectable and may be smaller than, equal to, or larger than the radius of the outer edge of the substrate. In embodiments, the radius of inner diameter surface 320 may have a value between 110 mm and 120 mm (e.g., when used to process a 300 mm wafer), or between 120 mm and 130 mm, or between 130 mm and 140 mm, or between 140 mm and 150 mm, or between 150 mm and 160 mm, or between 160 mm and 170 mm. In embodiments, the radius of outer diameter surface 310 is selectable and may be less than, equal to, or greater than the radius of the outer edge of the substrate. In some embodiments, the radius of the outer diameter surface 310 may be between 140 mm and 160 mm (when used to process 300 mm wafers), or between 150 mm and 180 mm, or between 150 mm and 200 mm, or between 150 mm and 220 mm, or between 150 mm and 240 mm, or between 150 mm and 250 mm. The intermediate portion 365 (e.g., if elliptical) may define a centerline 360 ​​(of corresponding radius) that defines the cylindrical contour of the outer upper electrode. Accordingly, the radius of the centerline 360 ​​may be selected and may be smaller than, equal to, or larger than the radius of the outer edge of the substrate. The cylindrical contour may exceed the height of the outer upper electrode 123B, which may have dimensions "A" plus "G." An intermediate portion 365 of the upper surface 305 defines the upper portion of the cylindrical profile.Specifically, the cylindrical contour includes a plurality of centerlines that intersect portions extending from a central axis 319 of the shaped outer top electrode 123B. Each centerline is parallel to the central axis 319, which is shown in FIG. 3A as going in and out of the plane. Each of the plurality of centerlines intersects perpendicularly with a middle portion 365 of the top surface. The cylindrical contour defined by the lines 360 may have an interior 325.

[0041] As shown, shaped bottom surface 301 is shaped with a specific curvature to provide managed plasma density control over the substrate being processed and to modify the plasma density to adjust wafer performance. The shaped bottom surface is configured to face the plasma generated within the plasma chamber. In particular, inner diameter surface 320 couples top surface 305 to shaped bottom surface 301. Additionally, inner diameter surface 320 includes transition edge 315. The height of inner diameter surface 320 between top surface 305 and transition edge 315, defined by line 371, is indicated by dimension "A." Outer diameter surface 310 similarly couples top surface 305 to shaped bottom surface 301.

[0042] The outer top electrode 123B includes a convex protrusion 330 on the shaped bottom surface 301. The convex protrusion protrudes or extends below the transition edge 315 of the inner diameter surface 320. Specifically, the convex protrusion includes a downwardly sloping surface 331 extending from the transition edge 315 to a micro-protrusion 335, as described above, and an upwardly sloping surface 332 extending from the micro-protrusion 335 toward the cylindrical contour, particularly toward the centerline 360 ​​along a corresponding radial, as shown in FIG. 3B . For example, the convex protrusion 330 has a height defined between the transition edge 315 defined by line 371 and the micro-protrusion 335 defined by line 372, further defined by dimension "G." In one embodiment, the micro-protrusion 335 is located in an interior region 325 of the cylindrical contour defined by the extension of the intermediate portion 365 by the centerline 360 ​​(e.g., taken along a corresponding radial). That is, as shown in Figure 3B, the nanoprotrusion 335 is located to the left of the centerline 360, or toward the center or central axis 319 of the substrate. For example, the nanoprotrusion 335 may be located a distance from the centerline 360 ​​defined by the dimension "C."

[0043] The outer upper electrode 123B includes a recessed portion 340 adjacent to the convex protrusion 330. The recessed portion 340 is formed on a first side with an upwardly inclined surface 340A extending from the infinitesimal protrusion 335 toward the cylindrical contour, specifically toward a centerline 360 ​​defined by the middle portion 365 of the upper surface 305 (along a corresponding radial line as shown in FIG. 3B ). The recessed portion includes a mesa surface 341A that may be located above the transition edge 315 (defined by line 371). The mesa surface 341A may be defined by a dimension “D.” As shown in FIG. 3B , the recessed portion 340 is located from the cylindrical contour and / or centerline 360 ​​toward the outer diameter surface 310. That is, at least a portion of the recessed portion is located to the right of the cylindrical contour and / or centerline 360.

[0044] Additionally, the outer upper electrode may include an extension 350 protruding from the outer diameter surface 310 having a height of dimension "E." For example, the extension may be formed on the downwardly sloping surface 340B on the second side of the recessed portion 340 and extend further below the outer diameter surface (e.g., below dimension "E"). The height of the extension 350 may be defined by dimension "F."

[0045] 3C illustrates another cross section of the outer top electrode 123B shown in FIG. 3A, including various exemplary configurations or modifications of recesses formed in the molded bottom surface, according to one embodiment of the present disclosure. The outer top electrode 123B has been previously described, and like-numbered components of the outer top electrode 123B shown in FIGS. 3A-3C have similar features and configurations. In particular, dimensions "A-F" may be modified to achieve a desired effect.

[0046] In particular, the configuration of recess 340 may be varied to achieve a desired effect (e.g., a desired etch rate at the edge). As shown, mesa surfaces may be varied by varying their width (e.g., defined by dimension "D") and height (e.g., defined by dimension "E"). For example, mesa surface 341A (shown in FIG. 3B) has a minimum height (e.g., closer to the level of transition edge 315 than top surface 305) and a maximum width, mesa surface 341B has an intermediate height, and mesa surface 341C has a maximum height (e.g., closer to the level of top surface 305 than transition edge 315 of inner diameter surface 320) and a minimum length.

[0047] Additionally, the configuration of the convex protrusion 330 may be varied to achieve a desired effect (e.g., a desired etch rate at the edge). For example, the height of the convex protrusion 330 may be varied, with the height being defined by dimension "G." That is, the level of the microprotrusion defined by line 372 may be varied to be further away from or closer to the transition edge 315. The width of the convex protrusion 330 may also be varied. For example, the position of the microprotrusion 335 relative to the cylindrical outline or relative to the corresponding radial centerline 360 ​​defined by dimension "C" may be changed. For example, the microprotrusion may be closer to the cylindrical outline and / or centerline 360 ​​or further away from the cylindrical outline and / or centerline 360. The height and width of the convex protrusion may affect the width of the recess (width defined by dimension "D"), and vice versa.

[0048] 3D illustrates another cross section of the outer top electrode 123B illustrated in FIG. 3A, showing an exemplary configuration or modification of the convex protrusions 330 and concave portions 340 formed in the molded bottom surface 301, according to one embodiment of the present disclosure. The outer top electrode 123B has been previously described, and like-numbered components of the outer top electrode 123B illustrated in FIGS. 3A-3D have similar features and configurations.

[0049] In particular, the configuration of the convex protrusion 330 may be altered to achieve a desired effect (e.g., a desired etch rate at the edge). For example, the height of the convex protrusion 330 may be altered, with the altered height indicated by the dimension "G-1." As shown, the height of the convex protrusion 330 increases between FIG. 3B (e.g., dimension "G") and FIG. 3D (e.g., dimension "G-1"). Additionally, the position of the micro-protrusion 335 may be altered, with the altered position indicated by the dimension "C-1." As shown, the position of the convex protrusion 330 moves closer to the cylindrical outline, specifically, closer to the centerline 360 ​​(e.g., cut along the corresponding radial) between FIG. 3B (e.g., dimension "C") and FIG. 3D (e.g., dimension "C-1").

[0050] The configuration of recess 340 may also be varied to achieve a desired effect (e.g., a desired etch rate at the edge). For example, the shape and height of recess 340 may be varied, with the varied height indicated by dimension "E-1." For example, the height of recess 340 decreases between FIG. 3B (e.g., dimension "E") and FIG. 3D (e.g., dimension "E-1"). Furthermore, the width of recess 340 decreases between FIG. 3B (e.g., dimension "D") and FIG. 3D (e.g., dimension "D-1"). The shape and height of extension 350 may also be varied, with the varied height indicated by dimension "F-1." For example, the height of extension 350 increases between FIG. 3B (e.g., dimension "F") and FIG. 3D (e.g., dimension "F-1").

[0051] 4 is a diagram of the interface between the inner top electrode 124B shown in FIG. 2 having a sloped bottom surface 420 and the outer top electrode 123B shown in FIG. 2 having a shaped bottom surface 301, according to one embodiment of the present disclosure. In particular, the outer top electrode 123B has been previously described, and like-numbered components of the outer top electrode 123B shown in FIGS. 3A-3C and 4 have similar features and configurations.

[0052] In particular, the inner upper electrode 124B may be configured in a disk shape, including a top surface 415 and a bottom surface 401 joined by an outer surface 430. The bottom surface 401 is configured to face the plasma and / or the process space in which the plasma is formed, and the bottom surface is shaped to achieve managed plasma density control, as previously described. For example, the bottom surface 401 may include a sloped bottom surface 420 portion at an outer edge or outer region of the inner upper electrode, including the outer surface 430. As shown, the sloped bottom surface extends from a lower end 431 of the outer surface 430 to a central protrusion (not shown). The central protrusion was previously described in connection with FIG. 2 . Specifically, the lower end 431 may be defined by a line 410. Furthermore, the sloped bottom surface 420 is angled at the lower end 431 relative to the line 410 by an angle theta (θ).

[0053] Additionally, as previously described, the outer upper electrode 123B is located adjacent to the inner upper electrode 124B. For brevity and clarity, the outer upper electrode is configured as an annular ring and includes a shaped bottom surface 301 configured to face the plasma and / or the process space in which the plasma is formed. The outer upper electrode 123B includes a top surface 305. An inner diameter surface 320 couples the top surface 305 to the shaped bottom surface 301, the inner diameter surface including a transition edge 315. The outer diameter surface 310 also couples the top surface 305 to the shaped bottom surface 301. The outer upper electrode 123B includes a shaped bottom convex protrusion 330 that protrudes below the transition edge 315 of the inner diameter surface 320. The convex protrusion 330 includes a miniature protrusion 335 at a level defined by a line 371. As shown, convex protrusion 330 includes a downwardly sloping surface 331 that extends from transition end 315 of inner diameter surface 320 to tiny protrusion 335 .

[0054] In one embodiment, the sloped bottom surface 420 of the inner upper electrode 124B is continued by the downwardly sloping surface 331 of the shaped bottom surface 301 of the outer upper electrode 123B at the boundary between the inner and outer upper electrodes. In particular, the lower end 431 of the outer surface 430 of the inner upper electrode 124B is adjacent to the transition edge 315 of the inner diameter surface 320 of the outer upper electrode 123B at the boundary. Specifically, the downwardly sloping surface 331 of the convex protrusion 330 may be an extension of the sloped bottom surface 420 of the inner upper electrode 124B at the boundary (e.g., the lower end 431 of the inner upper electrode and the transition edge 315 of the outer upper electrode). That is, the downwardly sloping surface 331 of the shaped bottom surface 301 of the outer upper electrode 123B is an extension of the sloped bottom surface 420 of the inner upper electrode 124B. As shown, the sloped bottom surface 420 of the inner top electrode 124B is at an angle defined by angle theta (θ) relative to line 410. Also, the downwardly sloping surface 331 of the outer top electrode 123B is at an angle defined by angle delta (Δ) relative to line 371. In one embodiment, the boundary is such that angle theta (θ) closely matches angle delta (Δ) such that the first slope angle theta (θ) of the sloped bottom surface 420 of the inner top electrode 124B approaches the second slope angle delta (Δ) of the downwardly sloping surface 331 of the outer top electrode 123B.

[0055] 5A-5C illustrate various offsets at the boundary of an outer top electrode 123B having a shaped bottom surface relative to an inner top electrode 124B having a shaped bottom surface, according to one embodiment of the present disclosure. For brevity and clarity, the outer top electrode 123B is shaped and the inner top electrode 124B is shaped, although it is understood that the outer top electrode 123B may be paired with an unshaped inner top electrode.

[0056] In particular, the offset of the outer top electrode 123B from the inner top electrode 124B is shown relative to the boundary between the lower end 431 of the outer surface 430 of the inner top electrode 124B and the transition edge 315 of the inner diameter surface 320 of the outer top electrode 123B. As shown, the lower end 431 of the outer surface 430 of the inner top electrode 124B is defined by line 370. Also, the transition edge 315 of the inner diameter surface 320 of the outer top electrode 123B is defined by line 371. The offset may be defined by the distance of dimension "H" between lines 370 and 371.

[0057] 5A shows that there is little or no offset between the outer upper electrode 123B and the inner upper electrode 124B at the boundary between the lower end 431 of the outer surface 430 of the inner upper electrode 124B and the transition edge 315 of the inner diameter surface 320 of the outer upper electrode 123B. That is, the distance in dimension "H-1" between lines 370 and 371 in FIG. 5A is approximately zero (0).

[0058] 5B shows that the outer top electrode 123B is offset upwardly from the inner top electrode 124B. That is, the transition edge 315 of the inner diameter surface 320 of the outer top electrode 123B is offset from the bottom edge 431 of the outer surface 430 of the inner top electrode 124B by a distance of dimension "H-2" defined between lines 370 and 371. As shown in FIG. 5B, the transition edge 315 is above the bottom edge 431 such that the transition edge 315 is farther from the corresponding substrate than the bottom edge 431.

[0059] 5C further illustrates that the outer top electrode 123B is offset downwardly from the inner top electrode 124B. That is, the transition edge 315 of the inner diameter surface 320 of the outer top electrode 123B is offset from the lower edge 431 of the outer surface 430 of the inner top electrode 124B by a distance of dimension "H-3" defined between lines 370 and 371. As shown in FIG. 5C, the transition edge 315 is below the lower edge 431 such that the transition edge 315 is closer to the corresponding substrate than the lower edge 431.

[0060] Without limitation, example systems for practicing embodiments of the present disclosure may include plasma etch chambers or modules, deposition chambers or modules, spin rinse chambers or modules, metal plating chambers or modules, cleaning chambers or modules, bevel edge etch chambers or modules, physical vapor deposition (PVD) chambers or modules, chemical vapor deposition (CVD) chambers or modules, plasma enhanced chemical vapor deposition (PECVD) chambers or modules, atomic layer deposition (ALD) chambers or modules, atomic layer etch (ALE) chambers or modules, ion implantation chambers or modules, track chambers or modules, and other semiconductor processing systems that may be related to or used in the fabrication and / or manufacturing of semiconductor wafers.

[0061] The foregoing description of the embodiments has been provided for purposes of illustration and description and is not intended to be exhaustive or limiting of the present disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, can be substituted and used in selected embodiments even if not specifically shown or described. They can also be modified in many ways. Such modifications are not considered a departure from the present disclosure, and all such modifications are intended to be within the scope of the present disclosure.

[0062] Although the foregoing embodiments have been described in some detail for purposes of clarity of understanding, it will be apparent that certain changes and modifications may be practiced within the scope of the appended claims. The present embodiments are therefore to be considered illustrative and not restrictive, and are not to be limited to the details set forth herein, but may be modified within the scope of the claims and their equivalents.

Claims

1. An outer upper electrode used for plasma processing, The molded base and An upper surface having a radial width, the middle portion of the upper surface having an elliptical shape, and A cylindrical outer shape that crosses the height of the outer upper electrode, the middle portion of the upper surface defines the upper part of the cylindrical outer shape, An inner diameter surface connecting the upper surface and the molded bottom surface, wherein the inner diameter surface includes a transition end, An outer diameter surface that connects the upper surface and the molded bottom surface, The molded bottom surface comprises a convex projection that protrudes below the transition end of the inner diameter surface, The convex projection includes an outer upper electrode, which is located in the internal region of the cylindrical outer shape, and includes a minute projection.

2. The outer upper electrode according to claim 1, The aforementioned convex projection is, A downward inclined surface extending from the transition end to the minimum protrusion, It includes an upward inclined surface extending from the minute protrusion toward the cylindrical outer shape, The cylindrical outer shape includes multiple centerlines that intersect with multiple radiations extending from the central axis of the outer upper electrode, Each of the aforementioned multiple center lines intersects with the intermediate portion of the upper surface, forming an outer upper electrode.

3. The outer upper electrode according to claim 2, The downward-sloping surface is an extension of the inclined bottom surface at the lower end of the outer surface of the inner upper electrode, which is the outer upper electrode.

4. The outer upper electrode according to claim 1, further, A concave portion formed on the first side having an upwardly inclined surface extending from the minute protrusion toward the cylindrical outer shape, wherein the cylindrical outer shape includes a plurality of center lines that intersect with a plurality of radiations extending from the central axis of the outer upper electrode, and each of the plurality of center lines has a concave portion that intersects with the intermediate portion of the upper surface. The concave portion is an outer upper electrode located toward the outer diameter surface from the cylindrical outer shape.

5. The outer upper electrode according to claim 4, The mesa surface of the concave portion is the outer upper electrode, which is closer to the upper surface than the transition end of the inner diameter surface.

6. The outer upper electrode according to claim 4, further, An outer upper electrode comprising an extended portion protruding from the outer diameter surface, wherein the extended portion is formed on the second side of the concave portion.

7. The outer upper electrode according to claim 1, The aforementioned outer upper electrode is an annular ring.

8. An upper electrode used for plasma processing, An inner upper electrode having a disc shape and including a first upper surface and a bottom surface joined by an outer surface, wherein the bottom surface includes an inclined bottom surface extending from the lower end of the outer surface to a central projection, The outer upper electrode adjacent to the inner upper electrode, The molded base and A second upper surface having a radial width, wherein the intermediate portion of the second upper surface has an elliptical shape, and A cylindrical outer shape that crosses the height of the outer upper electrode, the intermediate portion of the second upper surface defines the upper part of the cylindrical outer shape, An inner diameter surface connecting the second upper surface and the molded bottom surface, the inner diameter surface including the transition end, An outer diameter surface that connects the second upper surface and the molded bottom surface, The convex projection of the molded bottom surface that protrudes below the transition end of the inner diameter surface, It comprises an outer upper electrode including, The convex projection includes a minute projection located in the internal region of the cylindrical outer shape, and is an upper electrode.

9. The outer upper electrode according to claim 8, The aforementioned convex projection is, A downward inclined surface extending from the transition end to the minimum protrusion, It includes an upward inclined surface extending from the minute protrusion toward the cylindrical outer shape, The cylindrical outer shape includes multiple centerlines that intersect with multiple radiations extending from the central axis of the outer upper electrode, Each of the aforementioned plurality of center lines intersects with the intermediate portion of the second upper surface, forming an outer upper electrode.

10. The outer upper electrode according to claim 9, The downward inclined surface is an extension of the inclined bottom surface at the lower end of the outer surface of the inner upper electrode, which is the outer upper electrode.

11. The outer upper electrode according to claim 10, The first inclination of the inclined bottom surface of the inner upper electrode is close to the second inclination of the downward inclined surface of the outer upper electrode.

12. The outer upper electrode according to claim 8, further, It comprises a concave portion formed on the first side having an upwardly inclined surface extending from the minute protrusion toward the cylindrical outer shape, The cylindrical outer shape includes a plurality of centerlines that intersect with a plurality of radiations extending from the central axis of the outer upper electrode, and each of the plurality of centerlines intersects with the intermediate portion of the second upper surface. The concave portion is an outer upper electrode located toward the outer diameter surface from the cylindrical outer shape.

13. The outer upper electrode according to claim 12, The mesa surface of the concave portion is the outer upper electrode, which is closer to the second upper surface than the transition end of the inner diameter surface.

14. The outer upper electrode according to claim 12, further, An outer upper electrode comprising an extended portion protruding from the outer diameter surface, wherein the extended portion is formed on the second side of the concave portion.

15. The outer upper electrode according to claim 8, The aforementioned outer upper electrode is an annular ring.

16. A processing chamber, A base assembly for supporting the circuit board, An inner upper electrode, the inner upper electrode facing the base assembly, having a disc shape, and comprising a first upper surface and a bottom surface joined by an outer surface, the bottom surface including an inclined bottom surface extending from the lower end of the outer surface to a central projection, The outer upper electrode adjacent to the inner upper electrode, The molded base and A second upper surface having a radial width, wherein the intermediate portion of the second upper surface has an elliptical shape, and A cylindrical outer shape that crosses the height of the outer upper electrode, the intermediate portion of the second upper surface defines the upper part of the cylindrical outer shape, An inner diameter surface connecting the second upper surface and the molded bottom surface, the inner diameter surface including the transition end, An outer diameter surface that connects the second upper surface and the molded bottom surface, The convex projection of the molded bottom surface that protrudes below the transition end of the inner diameter surface, It comprises an outer upper electrode including, The convex projection includes a very small projection located in the internal region of the cylindrical outer shape, The processing chamber has an outer upper electrode which is an annular ring.

17. A processing chamber according to claim 16, The aforementioned convex projection is, A downward inclined surface extending from the transition end to the minimum protrusion, It includes an upward inclined surface extending from the minute protrusion toward the cylindrical outer shape, The cylindrical outer shape includes multiple centerlines that intersect with multiple radiations extending from the central axis of the outer upper electrode, Each of the aforementioned plurality of centerlines intersects with the intermediate portion of the second upper surface in the processing chamber.

18. A processing chamber according to claim 17, A processing chamber in which the downward inclined surface is an extension of the inclined bottom surface at the lower end of the outer surface of the inner upper electrode.

19. The processing chamber according to claim 16, further, It comprises a concave portion formed on the first side having an upwardly inclined surface extending from the minute protrusion toward the cylindrical outer shape, The cylindrical outer shape includes a plurality of centerlines that intersect with a plurality of radiations extending from the central axis of the outer upper electrode, and each of the plurality of centerlines intersects with the intermediate portion of the second upper surface. The concave portion is located on the outer diameter surface of the cylindrical outer shape, and is part of the processing chamber.

20. The processing chamber according to claim 19, further, It comprises an extended portion that protrudes from the outer diameter surface, The extended portion is a processing chamber formed on the second side of the concave portion.

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