Shaped silicon external top electrode for plasma processing

Abstract

An external top electrode for plasma processing. A bottom surface and a top surface having a radial width are shaped, wherein a middle portion of the top surface has an elliptical shape. The cylindrical profile spans a height of the outer upper electrode, wherein a middle portion of the top surface defines a top of the cylindrical profile. An inner diameter surface connects the top surface and the shaped bottom surface, wherein the inner diameter surface includes a transition edge. An outer diameter surface connects the top surface and the shaped bottom surface. A convex projection forming the bottom surface projects below the transition edge of the inner diameter surface, wherein the convex projection includes a projection lowest point located in an inner region of the cylindrical profile.

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 for adjusting plasma density to tune wafer performance. Background Art

[0002] Many modern semiconductor chip manufacturing processes (e.g., 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 within a plasma processing volume. The plasma contains various types of free radicals, electrons, and positive and negative ions. Chemical reactions of various free radicals, electrons, positive and negative ions are used to etch features, surfaces, and materials of the wafer.

[0003] For example, when a process gas is supplied into 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 process gas is turned into plasma by the RF signal, thereby plasma etching a predetermined layer disposed on a wafer. Unfortunately, during wafer processing, plasma formation may cause non-uniform features along the extreme edges of the wafer, thereby adversely affecting wafer performance during manufacturing.

[0004] It is against this background that embodiments of the present disclosure arise. Summary of the invention

[0005] The present embodiments relate to methods and apparatus for shaping an outer upper electrode with a specific curvature for adjusting plasma density to tune wafer performance. Several inventive embodiments of the present disclosure are described below.

[0006] An embodiment of the present disclosure provides an external upper electrode for plasma processing. The external upper electrode includes a shaped bottom surface. The external upper electrode includes a top surface having a radial width, wherein a middle portion of the top surface has an elliptical shape. The external upper electrode includes a cylindrical profile spanning the height of the external upper electrode, wherein the middle portion of the top surface defines the top of the cylindrical profile. The external upper electrode includes an inner diameter surface connecting the top surface and the shaped bottom surface, wherein the inner diameter surface includes a transition edge. The external upper electrode includes an outer diameter surface connecting the top surface and the shaped bottom surface. The external upper electrode includes a convex protrusion of the shaped bottom surface, which protrudes below the transition edge of the inner diameter surface, wherein the convex protrusion includes a protrusion lowest point located in an inner region of the cylindrical profile.

[0007] Other embodiments of the present disclosure provide an upper electrode for plasma processing. The upper electrode includes an inner upper electrode having a disk-shaped profile, which includes a first top surface and a bottom surface connected by an outer surface. The bottom surface includes an inclined bottom surface extending from a lower edge of the outer surface to a central protrusion. 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, wherein a middle portion of the second top surface has an elliptical shape. The outer upper electrode includes a cylindrical profile spanning the height of the outer upper electrode, wherein the middle portion of the second top surface defines the top of the cylindrical profile. The outer upper electrode includes an inner diameter surface connecting the second top surface and the shaped bottom surface, wherein the inner diameter surface includes 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 convex protrusion of the shaped bottom surface, which protrudes below the transition edge of the inner diameter surface, wherein the convex protrusion includes a protrusion lowest point located in the inner area of ​​the cylindrical profile.

[0008] Still other embodiments of the present disclosure provide a processing chamber configured for plasma processing. The processing chamber includes a susceptor assembly for supporting a substrate. The processing chamber includes an inner upper electrode having a disk-shaped profile facing the susceptor assembly, the inner upper electrode including a first top surface and a bottom surface connected by an outer surface. The bottom surface includes an inclined bottom surface extending from the lower edge 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, wherein a middle portion of the second top surface has an elliptical shape. The outer upper electrode includes a cylindrical profile spanning the height of the outer upper electrode, wherein the middle portion of the second top surface defines the top of the cylindrical profile. The outer upper electrode includes an inner diameter surface connecting the second top surface and the shaped bottom surface, wherein the inner diameter surface includes 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 convex protrusion of the shaped bottom surface that protrudes below the transition edge of the inner diameter surface, wherein the convex protrusion includes a protrusion lowest point located at the inner region of the cylindrical profile. The outer upper electrode is an annular ring.

[0009] Those skilled in the art will recognize these and other advantages after reading the entire specification and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The embodiments may be best understood by referring to the following description taken in conjunction with the accompanying drawings.

[0011] Figure 1 Embodiments of a capacitively coupled plasma (CCP) processing system for etching operations are shown according to embodiments of the present disclosure.

[0012] Figure 2 Embodiments according to the present disclosure show how the shapes of the inner and outer upper electrodes affect wafer performance during plasma processing.

[0013] Figure 3A A top surface of an outer upper electrode is shown according to an embodiment of the present disclosure, the outer upper electrode being shaped to have a specific curvature for adjusting plasma density to tune wafer performance during wafer manufacturing.

[0014] Figure 3B According to one embodiment of the present disclosure, Figure 3A , which is shaped to have a specific curvature for adjusting plasma density to adjust wafer performance during wafer manufacturing.

[0015] Figure 3C According to one embodiment of the present disclosure, Figure 3A Another cross-section of an outer upper electrode shown in , which includes various exemplary configurations or modifications of a concave portion formed in the shaped bottom surface.

[0016] Figure 3D According to one embodiment of the present disclosure, Figure 3A , which illustrates another exemplary configuration or modification of the convex portion formed in the shaped bottom surface.

[0017] Figure 4 is an interface between an inner upper electrode having an inclined bottom surface and an outer upper electrode having a shaped bottom surface according to an embodiment of the present disclosure.

[0018] Figure 5A-5C According to one embodiment of the present disclosure, an outer upper electrode having a shaped bottom surface is provided relative to an inner upper electrode having an inclined bottom surface. Figure 4 Various offsets at the interface introduced in . DETAILED DESCRIPTION

[0019] Although the following detailed description contains many specific details for illustrative purposes, it will be appreciated by those skilled in the art that many changes and modifications to the following details are within the scope of the present disclosure. Therefore, the aspects of the present disclosure described below are set forth without loss of generality and without imposing limitations on the claims following this specification.

[0020] In general, various embodiments of the present disclosure describe methods and apparatus for forming an outer upper electrode having a specific curvature for adjusting plasma density to adjust wafer performance. Specifically, the outer upper electrode includes one or more curved regions to achieve directional plasma density control of the wafer during processing. That is, the outer upper electrode includes a shaped bottom surface with a curved transition rather than a sharp transition (e.g., a sharp edge). In some embodiments, the outer upper electrode includes a shaped bottom surface that is an extension or continuation of the inclined bottom surface of the inner upper electrode.

[0021] Advantages of various embodiments of methods and apparatus for forming an outer upper electrode are disclosed including directional plasma density control over portions of a wafer. The ability to adjust the plasma density across the wafer provides improved performance at the edge of the substrate. For example, by forming the outer upper electrode, the plasma density across the substrate can be tuned to achieve etch rate uniformity across the diameter of the wafer that continues to the outer edge. This results in increased yield per wafer (i.e., yield of semiconductor chips).

[0022] Based on the above general understanding of various embodiments, exemplary details of the embodiments will now be described with reference to various drawings. Similar numbered elements and / or components in one or more figures are meant to generally have the same configuration and / or function. In addition, the figures may not be drawn to scale, but are intended to illustrate and emphasize novel concepts. Obviously, the present embodiment can be practiced without some or all of these specific details. In other cases, well-known process operations are not described in detail to avoid unnecessarily making the present embodiment difficult to understand.

[0023] Figure 1 An exemplary embodiment of a plasma processing system 100 for operations including etching and / or depositing films is shown according to one embodiment of the present disclosure. The plasma processing system 100 is configured to process a substrate or wafer 120, for example, by subjecting the substrate 120 to plasma treatment. For illustrative purposes, as shown in FIG. Figure 1 The plasma processing system 100 shown can 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 can be modified according to the design to generate plasma by various methods, such as inductively coupled plasma (ICP), etc. That is, the embodiments of the present disclosure (which include a shaped outer upper electrode with a specific curvature for adjusting plasma density to adjust wafer performance) can be implemented on various plasma processing systems (e.g., CCP, ICP, etc.) and each configuration variation thereof.

[0024] in particular, Figure 1An exemplary embodiment of a plasma processing system 100 for etching operations is shown, which is configured as a CCP processing system and includes a CCP plasma processing chamber 102. The plasma processing chamber 102 includes a substrate support or pedestal, such as an electrostatic chuck (ESC) 118 or a magnetic chuck. In an embodiment, the ESC can have several annular rings with different material types to achieve a specific capacitive coupling between the ESC and the optional edge ring 126. The lower electrode 122 can be embedded in the ESC 118. The substrate 120 can be placed on the pedestal for processing, wherein the substrate 120 is processed to manufacture one or more semiconductor chips. Facing the pedestal is an upper electrode, which can be configured as an inner upper electrode 124 and an outer upper electrode 123. As shown, the inner upper electrode 124 can be coupled to ground. In other embodiments, the inner upper electrode 124 can be coupled to an RF power source (e.g., supplying high frequency power, etc.). In some embodiments, the inner upper electrode 124 can be shaped to include an inclined bottom surface so as to adjust the plasma density across the diameter of the substrate 120. The inner upper electrode 124 can be configured to have an extension that can be shaped as a ring, such as the outer upper electrode 123. In some embodiments, the outer upper electrode 123 can be coupled to ground. There is a gap between the upper electrodes (i.e., the inner upper electrode 124 and the outer upper electrode 123) and the lower electrode 122 to form a processing volume, and a plasma 130 can be formed in the processing volume.

[0025] More specifically, the outer upper electrode 123 surrounds the inner upper electrode 124. It should be noted that the outer upper electrode 123 has an annular body, such as a circular body, an annular body, or a disk-shaped body. In an embodiment, the shape of the outer upper electrode 123 is designed to adjust the plasma density of the plasma 130 across the substrate 120 to achieve etching rate uniformity, especially toward the outer edge of the substrate 120. For example, an increased plasma density can be achieved in a region 131 of the plasma 130, where the region 131 can be a ring located below the outer upper electrode 123. Similarly, due to the protrusion in the central region of the inner upper electrode 124, an increased plasma density can be achieved in a region 132 of the plasma 130.

[0026] As shown in the figure, Figure 1 The plasma processing chamber 102 in the embodiment of the present invention may include a C-shaped shield 150 extending from the upper electrodes (e.g., the inner upper electrode 124 and the outer upper electrode 123) to the ESC 118 including the bottom electrode to provide additional plasma containment. The C-shaped shield may have a plurality of holes to allow gases and byproducts to flow out of the C-shaped shield. The C-shaped shield may be grounded. In other embodiments, the plasma processing chamber may be configured differently to include a confinement ring (not shown) for confining the plasma 130 during etching operations.

[0027] In another embodiment, the gas source 114 is connected to the plasma processing chamber 102 and is configured to inject the desired process gas into the plasma processing chamber 102. As an example of plasma formation, after providing one or more RF signals to the ESC 118 and injecting the process gas into the plasma processing chamber 102, a plasma 130 is formed between the upper electrode 124 and the ESC 118. The plasma 130 can 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 generating plasma. The RF power supply 110 is coupled to an impedance matching network 106, which is further coupled to the bottom electrode 122. The impedance matching network matches the impedance between the load (e.g., the plasma chamber 102 and any connecting cables) and the source (e.g., the source RF power supply and any connecting cables). That is, the matching network achieves 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 generally used to generate a plasma 130 using a process gas delivered from a gas source 114. For example, the RF power supply 110 can be a high frequency (HF) RF generator configured to generate a high frequency ranging from 13 megahertz (MHz) to 120 MHz (including 13 megahertz (MHz) to 120 MHz). For example, the frequency can be from 13 megahertz (MHz) to 120 MHz (including 13 megahertz (MHz) to 120 MHz). For example, the high frequency is a baseline frequency of 13.56 MHz or 27 MHz or 40 MHz or 60 MHz or 100 MHz. In embodiments, various configurations of power delivery can be implemented according to the configuration of the plasma processing system 100, including: providing RF power using one or more signals at one or more frequencies, which are delivered to the upper electrode and / or the lower electrode; providing bias power to the lower electrode, wherein the RF power and / or the bias power can be pulsed or continuous; and the like.

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

[0030] Figure 2 How the shape of the internal upper electrode and the external upper electrode affects the wafer performance during plasma processing is shown according to an embodiment of the present invention. Specifically, three figures (e.g., 200A, 200B, and 200C) show the etching rate on the corresponding substrate (not shown) for a variety of configurations of the internal upper electrode and / or the external upper electrode. For illustration purposes only, the substrate can have a diameter of 300mm (mm) and a corresponding radius of 150mm. It should be understood that the embodiments of the present disclosure can be implemented on a wafer of any size when the internal upper electrode and the external upper electrode are appropriately modified (e.g., adjusting the size of one or more of the internal upper electrode and the external upper electrode). The embodiments of the present disclosure include a shaped external upper electrode, which is configured to adjust the plasma density to adjust the wafer performance (e.g., to achieve uniformity of etching rate on the entire surface of the wafer).

[0031] For ease of comparison, the three figures (e.g., 200A, 200B, and 200C) are aligned and share a center line 250 (e.g., the center of the substrate), share an outer diameter shown by lines 255A and 255B, and share an outer radius region of the substrate having an inner diameter shown by lines 257A and 257B. In an embodiment, center line 250 may correspond to the central axis of each internal upper electrode (e.g., 124A and 124B) and / or each external upper electrode (e.g., 123A and 123B). The outer radius region is also referred to as an exclusion region of the substrate, wherein the exclusion region is typically subject to a low etching rate, but when the shaped external upper electrode of the present embodiment is implemented, a higher etching rate and a more uniform etching rate (e.g., compared to the etching rate in the central region of the substrate) are shown. More specifically, the outer radius region can be defined as a ring and is shown between lines 255A and 257A on the left side of Figure 200A, and between lines 255B and 257B on the right side of Figure 200A. For example, the outer radius region may include the outer 20 mm to 30 mm of the substrate (e.g., a 300 mm substrate with a 150 mm radius or a substrate with a different diameter). In an embodiment, the inner radius of the shaped upper outer electrode 123B may start from a smaller radius within the outer radius of the substrate, or may start from a larger radius outside the outer radius of the substrate.

[0032] For example, Figure 200A shows the etching rate of the unmodified upper electrode on the substrate. That is, the internal upper electrode 124A is not formed and includes a flat bottom surface facing the plasma. In addition, the external upper electrode 123A is not formed and also includes a flat bottom surface facing the plasma. In some implementations, the bottom surfaces of the internal upper electrode 124A and the external upper electrode 123A are coplanar. Vertical line 240A shows the relative etching rate on one or more radii of the corresponding radial direction (for example, for a 300mm substrate, a radius between 0 and 150mm), wherein horizontal line 245A shows the different radii of the corresponding radial direction of the substrate. Specifically, line 210 shows the etching rate of the unformed internal upper electrode and the unformed external upper electrode on the entire diameter of the substrate. The etching rate shown in line 210 is mirrored around the center line 250 and shows a relatively constant etching rate in the central area of ​​the substrate (for example, from the center of the substrate to a radius between about 50mm-65mm). The higher etch rate is shown by protrusions 211A and 211B (radius range between about 65 mm and 130 mm). The etch rate shown in line 210 drops significantly to zero (0) in the exclusion zone (i.e., radius range between about 130 mm and 150 mm), making the etch rate very low in the outer radius region of the substrate. It is desirable to have a uniform etch rate over the radius of the substrate, which can be achieved by forming the inner upper electrode and the outer upper electrode in the embodiment.

[0033] Figure 200B shows the etching rate on the substrate for the partially modified upper electrode. That is, the internal upper electrode 124B has been formed and includes a shaped and inclined bottom surface facing the plasma, wherein the inclined bottom surface is configured to adjust the plasma density in the central region of the substrate to achieve a uniform etching rate over the entire substrate (especially in the central region). Specifically, the inclined bottom surface may include a central protrusion, which can increase the plasma density of the plasma above the central region of the substrate. In some embodiments, the thickness of the central protrusion of the internal upper electrode 124B along line 250 is greater than the thickness of the central region of the internal upper electrode 124A along line 250. For example, the central protrusion of the internal upper electrode 124B can be designed to extend toward the substrate to increase the plasma density above the central region of the substrate to a desired level (for example, to increase the etching rate). On the other hand, the external upper electrode 123A is not formed and also includes a flat and plasma-facing bottom surface (i.e., similar to the bottom surface shown in Figure 200A). For the purpose of illustration, the central protrusion of the internal upper electrode 124B can extend below the bottom surface of the external upper electrode 123A.

[0034] Vertical line 240B shows the relative etching rate on one or more radii (e.g., between 0 and 150 mm for a 300 mm substrate) in the corresponding radial direction, where horizontal line 245B shows different radii in the corresponding radial direction of the substrate. Specifically, line 220 shows the etching rate of the formed inner upper electrode and the unformed outer upper electrode on the substrate diameter. Figure 200B compares the etching rate between line 220 and line 210. Specifically, the etching rate shown in line 220 is mirrored around center line 250 and indicates that there is a relatively constant etching rate on most substrates (e.g., between about 0 and 120 degrees of radius). That is, the bottom surface of the inner upper electrode is shaped (e.g., a central protrusion) to increase the plasma density in the central region of the substrate (e.g., from the center of the substrate to a radius between about 50 mm-65 mm), and is also shaped (beveled at the outer diameter) to reduce the plasma density in the region corresponding to protrusions 211A and 211B in Figure 200A (e.g., a radius ranging between about 65 mm and 130 mm of the substrate). 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 upper electrode (inner or outer) can affect the plasma density of the plasma formed on the substrate. For example, as the distance between the bottom surface of the upper electrode and the substrate becomes smaller, the plasma density may increase. Similarly, as the distance between the bottom surface of the upper electrode and the substrate becomes larger, the plasma density may decrease.

[0035] Thus, when comparing FIG. 200B to FIG. 200A , the shaped internal upper electrode 124B increases the etching rate of the central region of the substrate and decreases the etching rate of the substrate between a radius of about 65 to 130 mm (e.g., corresponding to the protrusions 211A and 211B of FIG. 200A ). For example, the etching rate of the majority of the region of the substrate shown by line 220 (e.g., between a radius of about 0 to 120 degrees) may be higher than the etching rate of the central region of the substrate shown by line 210 (e.g., between a radius of about 0 to 50-65 degrees). In addition, between a radius of about 0 to 50-65 degrees (e.g., previously corresponding to the protrusions 211A and 211B associated with FIG. 200A ), the etching rate shown by line 220 may be lower than the corresponding etching rate shown by line 210. Thus, a relatively constant etching rate is achieved between a radius of about 0 to 120 degrees, as shown by line 220 of FIG. 200B . In addition, due in part to the unformed outer upper electrode 123A, the etch rate shown in line 220 drops significantly to zero (0) in the exclusion zone (i.e., the radius ranges from 130 to 150 mm), making the etch rate very low in the outer radius region of the substrate. This etch rate may be similar to the etch rate shown in line 210 of FIG. 200A. It is desirable to have a uniform etch rate across the radius of the substrate, particularly toward the outer regions of the substrate, which can be achieved by the shaped inner upper electrode and outer upper electrode in the embodiment, and is shown in FIG. 200C.

[0036] Figure 200C shows the etch rate of the modified upper electrode on the substrate. Specifically, the internal upper electrode 124B has been shaped and includes a shaped and plasma-facing inclined bottom surface, wherein the inclined bottom surface is configured to adjust the plasma density in the central region of the substrate to achieve a uniform etching rate across the substrate (particularly in the central region). For example, the inclined bottom surface may include a central protrusion that can increase the plasma density of the plasma in the central region of the substrate. The internal upper electrode 124B has been fully described with respect to Figure 200B. In addition, the external upper electrode 123B has been shaped and includes a shaped and plasma-facing bottom surface, wherein the shaped bottom surface is configured to adjust the plasma density in the outer region (e.g., the exclusion zone) of the substrate (e.g., generally increase). For example, the shaped bottom surface includes one or more convex protrusions, a concave portion adjacent to the convex protrusion, and / or an extension portion adjacent to the concave portion. For illustrative purposes, in one embodiment, the lowest point of the central protrusion of the internal upper electrode 124B can be aligned with the lowest point of the convex protrusion of the external upper electrode 123B (e.g., the lowest point of the protrusion). Figure 3A-3D and Figure 4 A more detailed description of the shaped outer upper electrode 123B is provided.

[0037] Vertical line 240C shows the relative etching rate on one or more radii (e.g., for a 300mm substrate, between 0 and 150mm) in the corresponding radial direction, wherein horizontal line 245B shows the different radii in the corresponding radial direction of the substrate. Specifically, line 230 shows the etching rate on the entire diameter of the substrate for the internal upper electrode of the forming and the external upper electrode of the same forming. Figure 200C compares the etching rate between line 230 and line 210 (corresponding to the non-forming upper electrode in Figure 200A). Specifically, the etching rate shown in line 230 is mirrored around the center line 250, and shows a relatively constant etching rate on the entire substrate (e.g., between a radius of about 0 to 140-150 degrees), especially in the exclusion zone of the substrate. At the outer edge of the substrate (e.g., close to 150mm), the etching rate drops sharply. Specifically, as previously described, the bottom surface of the inner upper electrode 124B is shaped to increase the plasma density in the central region of the substrate (e.g., from the center of the substrate to a radius between about 50-65 mm), and is also shaped (sloped at the outer diameter) to reduce the plasma density in the region corresponding to the protrusions 211A and 211B in Figure 200A (e.g., a radius range between about 65 mm and 130 mm of the substrate). In addition, the shaped bottom surface of the outer upper electrode 123B is shaped to increase the plasma density in the exclusion zone and toward the outer diameter surface. 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 upper electrode (inner or outer) can be designed to adjust the plasma density of the plasma formed on the substrate.

[0038] Thus, when comparing FIG. 200C to FIG. 200A, the shaped internal upper electrode 124B increases the etching rate in the central region of the substrate and decreases the etching rate in the radius of the substrate between about 65 mm and 130 mm (e.g., corresponding to the protrusions 211A and 211B of FIG. 200A), as previously described when comparing FIG. 200B to FIG. 200A in the same region. In addition, because the external upper electrode 12B is shaped (e.g., includes a shaped bottom surface), the etching rate in the exclusion area in FIG. 200C (e.g., between about 130 mm-150 mm) is significantly higher than the etching rate in FIG. 200A. In this way, a relatively constant etching rate is achieved across the entire substrate (e.g., between radii of about 0 to 150 mm), as shown by line 230 of FIG. 200C, wherein the etching rate drops sharply only near the outer edge of the substrate (e.g., near 150 mm). Therefore, through the combination of forming the inner upper electrode and forming the outer upper electrode, a uniform etching rate across the entire radius of the substrate is achieved, especially a uniform etching rate toward the outer edge and / or diameter of the substrate, as shown in Figure 200C.

[0039] Figure 3A-3B Shows Figure 2 The exemplary shape of the outer upper electrode 123B introduced in the present invention includes a shaped bottom surface for adjusting and / or controlling the plasma density on the substrate during processing to adjust the wafer performance. Figure 3B According to one embodiment of the present disclosure, Figure 3A The cross section of the outer upper electrode 123B taken along the line Z--Z shown in FIG. 1 is shaped to have a specific curvature for adjusting plasma density to adjust wafer performance during wafer manufacturing. Figure 3A-3B The dimensions shown in are intended to be variable, with the values ​​of the dimensions being selected by design.

[0040] In particular, the outer upper electrode 123B is configured as an annular ring. The outer upper electrode has a top surface 305. The top surface 305 has a radial width defined by an optional dimension "B". In an embodiment, dimension "B" may have a value between 10 mm and 20 mm, or may have a value between 20 mm and 30 mm, or may have a value between 30 mm and 40 mm, or may have a value between 40 mm and 50 mm, or may have a value between 50 mm and 60 mm, or may have a value between 60 mm and 70 mm. The top surface 305 has a middle portion 365, which may be configured as an ellipse and / or a circle and is located between the inner diameter surface 320 and the outer diameter surface 310 of the outer upper electrode 123B. In an embodiment, the radius of the inner diameter surface 320 is optional and may be less than, equal to, or greater than the radius of the outer edge of the substrate. In an embodiment, the radius of the inner diameter surface 320 (e.g., when used to process 300 mm wafers) can have a value between 110 mm and 120 mm, or can have a value between 120 mm and 130 mm, or can have a value between 130 mm and 140 mm, or can have a value between 140 mm and 150 mm, or can have a value between 150 mm and 160 mm, or can have a value between 160 mm and 170 mm. In an embodiment, the radius of the outer diameter surface 310 is optional and can be less than, equal to, or greater than the radius of the outer edge of the substrate. In an embodiment, the radius of the outer diameter surface 310 (e.g., when used to process 300 mm wafers) can have a value between 140 mm and 160 mm, or can have a value between 150 mm and 180 mm, or can have a value between 150 mm and 200 mm, or can have a value between 150 mm and 220 mm, or can have a value between 150 mm and 240 mm, or can have a value between 150 mm and 250 mm. The middle portion 365 (e.g., elliptical) can define a center line 360 ​​(in a corresponding radial direction) that forms a cylindrical profile of the outer upper electrode. Accordingly, the radius of the center line 360 ​​is optional and can have a value less than, equal to, or greater than the radius of the outer edge of the substrate. The cylindrical profile can span the height of the outer upper electrode 123B, where the height can have the dimensions of "A" plus "G". The middle portion 365 of the top surface 305 defines the top of the cylindrical profile. More specifically, the cylindrical profile includes a plurality of center lines that intersect a plurality of radial directions extending from a central axis 319 of the formed outer upper electrode 123B. Each center line is parallel to the central axis 319, wherein the central axis 319 is Figure 3A360 as entering and leaving the page. Each of the plurality of center lines intersects the middle portion 365 of the top surface perpendicularly. The cylindrical profile defined by line 360 ​​may have an interior 325.

[0041] As shown, the shaped bottom surface 301 is shaped to have a specific curvature to achieve directional plasma density control on the substrate during processing and adjust the plasma density to adjust the wafer performance. The shaped bottom surface is configured to face the plasma generated in the plasma chamber. Specifically, the inner diameter surface 320 connects the top surface 305 and the shaped bottom surface 301. In addition, the inner diameter surface includes a transition edge 315. The height of the inner diameter surface 320 between the top surface 305 and the transition edge 315 defined by line 371 is represented by dimension "A". In addition, the outer diameter surface 310 connects the top surface 305 and the shaped bottom surface 301.

[0042] The outer upper electrode 123B includes a convex protrusion 330 that forms the 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 inclined surface 331 extending from the transition edge 315 to the lowest point 335 of the protrusion, and a convex protrusion extending from the lowest point 335 of the protrusion toward the cylindrical profile (more specifically, along the corresponding radial direction toward the centerline 360, as previously described). Figure 3B 310 and 311. The convex protrusion 330 has an upwardly inclined surface 332 extending from the substrate 300 (as shown). For example, the convex protrusion 330 has a height defined between the transition edge 315 defined by line 371 and the protrusion lowest point 335 defined by line 372, as further defined by dimension "G". In one embodiment, the protrusion lowest point 335 is located in the inner region 325 of the cylindrical profile defined by the centerline 360 ​​and by the intermediate extension 365 (e.g., taken along the corresponding radial direction). That is, the protrusion lowest point 335 is located to the left of the centerline 360, either toward the center of the substrate or toward the central axis 319, as shown. Figure 3B For example, the protrusion lowest point 335 can be located a distance from the centerline 360 ​​defined by dimension "C".

[0043] The outer upper electrode 123B includes a concave portion 340 adjacent to the convex protrusion 330. The concave portion 340 forms an upwardly inclined surface 340A on a first side, which extends from the lowest point 335 of the protrusion to a cylindrical profile, more specifically, (along the Figure 3B The concave portion 340 may extend from the cylindrical profile and / or centerline 360 ​​toward the outer diameter surface 310, as shown, to the centerline 360 ​​defined by the middle portion 365 of the top surface 305. The concave portion includes a land 341A, which may be located above the transition edge 315 (defined by line 371). The land 341A may be defined by dimension "D". As shown, the concave portion 340 is positioned from the cylindrical profile and / or centerline 360 ​​toward the outer diameter surface 310, as shown. Figure 3BThat is, at least a portion of the concave portion is located to the right of the cylindrical profile and / or centerline 360.

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

[0045] Figure 3C According to one embodiment of the present disclosure, Figure 3A Another cross-section of the external upper electrode 123B shown in FIG. 1 includes various exemplary configurations or modifications of the concave portion formed in the shaped bottom surface. The external upper electrode 123B has been described previously, wherein Figure 3A-3C Similar reference components of the outer upper electrode 123B shown in FIG. 1 have similar features and similar configurations. Specifically, dimension "AF" may be modified to achieve the desired effect.

[0046] Specifically, the configuration of the concave portion 340 can be modified to achieve a desired effect (e.g., a desired etch rate in the exclusion zone). As shown, the mesas can be modified to have different widths (e.g., defined by dimension "D") and different heights (e.g., defined by dimension "E"). For example, mesas 341A (at Figure 3B ) has a minimum height (e.g., closer to the level of the transition edge 315 than the top surface 305) and a widest length, mesa 341B has a medium height, and mesa 341C has a maximum height (e.g., closer to the top surface 305 than the transition edge 315 of the inner diameter surface 320) and a minimum length.

[0047] In addition, the configuration of the convex protrusion 330 can be modified to achieve a desired effect (e.g., a desired etching rate in the exclusion zone). For example, the height of the convex protrusion 330 can be modified, where the height is defined by dimension "G". That is, the height of the lowest point of the protrusion defined by line 372 can be modified to be further away from the transition edge 315 or closer to the transition edge 315. In addition, the width of the convex protrusion 330 can be modified. For example, the position of the lowest point of the protrusion 335 relative to the cylindrical profile or centerline 360 ​​along the corresponding radial direction (defined by dimension "C") can be changed. For example, the lowest point of the protrusion can be closer to the cylindrical profile and / or centerline 360, or further away from the cylindrical profile and / or centerline 360. The height and width of the convex protrusion can affect the width of the concave portion (the width defined by dimension "D"), and vice versa.

[0048] Figure 3DAccording to one embodiment of the present disclosure, Figure 3A , which shows an exemplary configuration or modification of the convex protrusions 330 and concave portions 340 formed in the shaped bottom surface 301. The external upper electrode 123B has been described previously, wherein Figure 3A-3D Similar reference components of the external upper electrode 123B shown in FIG. 1 have similar features and a similar configuration.

[0049] In particular, the configuration of the convex protrusion 330 can be modified to achieve a desired effect (e.g., a desired etch rate in the exclusion zone). For example, the height of the convex protrusion 330 can be modified, where the modified height is represented by the dimension "G-1". As shown, the height of the convex protrusion 330 is Figure 3B (e.g., size "G") and Figure 3D (e.g., dimension "G-1") is increased. In addition, the position of the lowest point 335 of the protrusion can be modified, wherein the modified position is represented by dimension "C-1". As shown in the figure, Figure 3B (e.g., dimension "C") and Figure 3D (eg, dimension "C-1"), the location of convex protrusion 330 has moved closer to the cylindrical profile, and more specifically, closer to centerline 360 ​​(eg, taken along a corresponding radial direction).

[0050] In addition, the configuration of the concave portion 340 can be modified to achieve a desired effect (e.g., a desired etch rate in the exclusion zone). For example, the shape and height of the concave portion 340 can be modified, where the modified height is represented by dimension "E-1". Figure 3B (e.g., dimension "E") and Figure 3D (e.g., dimension "E-1"), the height of the concave portion 340 has been reduced. In addition, the width of the concave portion 340 is between Figure 3B (e.g., dimension "D") and Figure 3D (dimension "D-1"). In addition, the shape and height of extension 350 can be modified, wherein the modified height is represented by dimension "F-1". For example, the height of extension 350 is Figure 3B (e.g., dimension "F") and Figure 3D (e.g., dimension "F-1").

[0051] Figure 4 is an embodiment according to the present disclosure, Figure 2 The internal upper electrode 124B having the inclined bottom surface 420 introduced in Figure 2 301. Specifically, the external upper electrode 123B has been described previously, wherein Figure 3A-3C and Figure 4 Similar reference components of the external upper electrode 123B shown in FIG. 1 have similar features and a similar configuration.

[0052] Specifically, the inner upper electrode 124B can be configured to have a disk-like profile and include a top surface 415 and a bottom surface 401 connected by an outer surface 430. The bottom surface 401 is configured to face the plasma and / or a processing volume in which the plasma is formed, wherein the bottom surface is shaped to achieve directional plasma density control, as previously described. For example, the bottom surface 401 includes a sloped bottom surface 420 portion located at an outer edge or region of the inner upper electrode including the outer surface 430. As shown, the sloped bottom surface extends from a lower edge 431 of the outer surface 430 to a central protrusion (not shown), wherein the central protrusion is at the front about Figure 2 More specifically, the lower edge 431 may be defined by the line 410. In addition, the inclined bottom surface 420 at the lower edge 431 has an angle defined by an angle theta (θ) with respect to the line 410.

[0053] In addition, as previously described, the outer upper electrode 123B is located adjacent to the inner upper electrode 124B. For simplicity and clarity, the outer upper electrode is configured as an annular ring and includes a shaped bottom surface 301, which is configured to face the plasma and / or a processing volume in which the plasma is formed. The outer upper electrode 123B includes a top surface 305. An inner diameter surface 320 connects the top surface 305 and the shaped bottom surface 301, wherein the inner diameter surface includes a transition edge 315. In addition, the outer diameter surface 310 connects the top surface 305 and the shaped bottom surface 301. The outer upper electrode 123B includes a convex protrusion 330 of the shaped bottom surface, which protrudes below the transition edge 315 of the inner diameter surface 320. The convex protrusion 330 includes a protrusion minimum point 335 at a level defined by line 371. As shown, the convex protrusion 330 includes a downwardly inclined surface 331 extending from the transition edge 315 of the inner diameter surface 320 to the protrusion minimum point 335.

[0054] In one embodiment, the inclined bottom surface 420 of the inner upper electrode 124B is continued by the downwardly inclined surface 331 of the shaped bottom surface 301 of the outer upper electrode 123B at the interface between the inner upper electrode and the outer upper electrode. Specifically, at the interface, the lower edge 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. More specifically, the downwardly inclined surface 331 of the convex protrusion 330 can be a continuation of the inclined bottom surface 420 of the inner upper electrode 124B at the interface (e.g., at the lower edge 431 of the inner upper electrode and the transition edge 315 of the outer upper electrode). That is, the downwardly inclined surface 331 of the shaped bottom surface 301 of the outer upper electrode 123B is a continuation of the inclined bottom surface 420 of the inner upper electrode 124B. As shown, the inclined bottom surface 420 of the inner upper electrode 124B has an angle defined by the angle theta (θ) relative to the line 410. Additionally, the downwardly inclined surface 331 of the outer upper electrode 123B has an angle defined by angle delta(Δ) relative to line 371. In one embodiment, at the interface, the angle theta(θ) closely matches the angle delta(Δ) such that the first angle of inclination theta(θ) of the inclined bottom surface 420 of the inner upper electrode 124B approximates the second angle of inclination delta(Δ) of the downwardly inclined surface 331 of the outer upper electrode 123B.

[0055] Figure 5A-5C Various offsets at the interface of an outer upper electrode 123B having a shaped bottom surface relative to an inner upper electrode 124B having a shaped bottom surface are shown according to one embodiment of the present disclosure. For simplicity and clarity, the outer upper electrode 123B is shaped and the inner upper electrode 124B is also shaped, but it should be understood that the outer upper electrode 123B can be paired with an unshaped inner upper electrode.

[0056] Specifically, the offset of the outer upper electrode 123B relative to the inner upper electrode 124B is shown relative to the interface between the lower edge 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. As shown, the lower edge 431 of the outer surface 430 of the inner upper electrode 124B is defined by the line 370. In addition, the transition edge 315 of the inner diameter surface 320 of the outer upper electrode 123B is defined by the line 371. The offset can be defined by the distance of dimension "H" between the lines 370 and 371.

[0057] Figure 5AIt is shown that at the interface between the lower edge 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, the outer upper electrode 123B has little or no offset relative to the inner upper electrode 124B. That is, Figure 5A The distance of dimension "H-1" between center lines 370 and 371 is approximately zero (0).

[0058] Figure 5B The outer upper electrode 123B is shown offset in an upward direction relative to the inner upper electrode 124B. That is, the transition edge 315 of the inner diameter surface 320 of the outer upper electrode 123B is offset relative to the lower edge 431 of the outer surface 430 of the inner upper electrode 124B by a distance of dimension "H-2" defined between lines 370 and 371. As shown, the transition edge 315 is located above the lower edge 431, as shown in FIG. Figure 5B As shown, the transition edge 315 is positioned further away from the corresponding substrate than the lower edge 431 .

[0059] also, Figure 5C The outer upper electrode 123B is shown offset in a downward direction relative to the inner upper electrode 124B. That is, the transition edge 315 of the inner diameter surface 320 of the outer upper electrode 123B is offset relative to the lower edge 431 of the outer surface 430 of the inner upper electrode 124B by a distance of dimension "H-3" defined between lines 370 and 371. Figure 5C As shown, transition edge 315 is located below lower edge 431 , such that transition edge 315 is closer to the corresponding substrate than lower edge 431 .

[0060] Exemplary systems may include, but are not limited to, plasma etching chambers or modules, deposition chambers or modules, spin rinse chambers or modules, metal plating chambers or modules, cleaning chambers or modules, chamfer edge etching 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 etching (ALE) chambers or modules, ion implantation chambers or modules, track chambers or modules, and any other semiconductor processing system that may be associated with or used in the preparation and / or manufacture of semiconductor wafers.

[0061] The description of the above embodiments is provided for the purpose of illustration and description. It is not intended to be exhaustive or to limit the present disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but are interchangeable where applicable, and may also be used in selected embodiments even if not specifically shown or described. It may also be varied in a variety of ways. Such variations should not be considered as departing from the present disclosure, and all such modifications are intended to be included within the scope of the present disclosure.

[0062] Although the above embodiments have been described in some detail for the purpose of clear understanding, it is obvious that certain changes and modifications may be implemented within the scope of the appended claims. Therefore, the embodiments of the present invention should be considered illustrative rather than restrictive, and these embodiments are not limited to the details given here, but may be modified within the scope and equivalent scheme of the claims.

Claims

1. An external upper electrode for plasma processing, comprising: forming a bottom surface; a top surface having a radial width, wherein a middle portion of the top surface has an elliptical shape; a cylindrical profile spanning the height of the outer upper electrode, wherein the middle portion of the top surface defines a top of the cylindrical profile; an inner diameter surface connecting the top surface and the shaped bottom surface, wherein the inner diameter surface includes a transition edge; an outer diameter surface connecting the top surface and the shaped bottom surface; a convex protrusion of the shaped bottom surface that projects below the transition edge of the inner diameter surface, The convex protrusion includes a protrusion lowest point located in the inner area of ​​the cylindrical contour.

2. The outer upper electrode according to claim 1, wherein the convex protrusion comprises: a downwardly sloping surface extending from the transition edge to the lowest point of the protrusion; as well as An upwardly inclined surface extends from a lowest point of the protrusion toward the cylindrical profile, wherein the cylindrical profile includes a plurality of centerlines intersecting a plurality of radials extending from a central axis of the outer upper electrode, wherein each of the plurality of centerlines intersects the middle portion of the top surface.

3. The external upper electrode according to claim 2, wherein the downwardly inclined surface is a continuation of the inclined bottom surface at the lower edge of the outer surface of the inner upper electrode, The inner upper electrode is adjacent to the outer upper electrode.

4. The external upper electrode according to claim 1, further comprising: a concave portion formed on the first side having an upwardly inclined surface extending from a lowest point of the protrusion toward the cylindrical profile, wherein the cylindrical profile includes a plurality of center lines intersecting a plurality of radial directions extending from a central axis of the outer upper electrode, wherein each of the plurality of center lines intersects the middle portion of the top surface, Wherein the concave portion is located from the cylindrical profile towards the outer diameter surface.

5. The external upper electrode according to claim 4, The land of the concave portion is closer to the top surface than the transition edge of the inner diameter surface.

6. The external upper electrode according to claim 4, further comprising: an extension protruding from the outer diameter surface, Wherein the extension is formed on the second side of the concave portion.

7. The external upper electrode according to claim 1, Wherein the outer upper electrode is an annular ring.

8. An upper electrode for plasma processing, comprising: an inner upper electrode having a disk-shaped profile including a first top surface and a bottom surface connected by an outer surface, wherein the bottom surface includes an inclined bottom surface extending from a lower edge of the outer surface to a central protrusion; an outer upper electrode adjacent to the inner upper electrode, wherein the outer upper electrode comprises: forming a bottom surface; a second top surface having a radial width, wherein a middle portion of the second top surface has an elliptical shape; a cylindrical profile spanning the height of the outer upper electrode, wherein the middle portion of the second top surface defines a top of the cylindrical profile; an inner diameter surface connecting the second top surface and the shaped bottom surface, wherein the inner diameter surface includes a transition edge; an outer diameter surface connecting the second top surface and the shaped bottom surface; a convex protrusion of the shaped bottom surface that projects below the transition edge of the inner diameter surface, The convex protrusion includes a protrusion lowest point located in the inner area of ​​the cylindrical contour.

9. The outer upper electrode according to claim 8, wherein the convex protrusion comprises: a downwardly sloping surface extending from the transition edge to the lowest point of the protrusion; as well as An upwardly inclined surface extends from a lowest point of the protrusion toward the cylindrical profile, wherein the cylindrical profile includes a plurality of centerlines intersecting a plurality of radials extending from a central axis of the outer upper electrode, wherein each of the plurality of centerlines intersects the middle portion of the top surface.

10. The external upper electrode according to claim 9, wherein the downwardly inclined surface is a continuation of the inclined bottom surface at the lower edge of the outer surface of the inner upper electrode.

11. The external upper electrode according to claim 10, wherein a first slope of the inclined bottom surface of the inner upper electrode is similar to a second slope of the downwardly inclined surface.

12. The external upper electrode according to claim 8, further comprising: a concave portion formed on the first side having an upwardly sloping surface extending from the lowest point of the protrusion toward the cylindrical profile, wherein the cylindrical profile includes a plurality of centerlines intersecting a plurality of radial directions extending from a central axis of the outer upper electrode, wherein each of the plurality of centerlines intersects the middle portion of the top surface, Wherein the concave portion is located from the cylindrical profile towards the outer diameter surface.

13. The external upper electrode according to claim 12, The land of the concave portion is closer to the second top surface than the transition edge of the inner diameter surface.

14. The external upper electrode according to claim 12, further comprising: an extension protruding from the outer diameter surface, Wherein the extension is formed on the second side of the concave portion.

15. The external upper electrode according to claim 8, Wherein the outer upper electrode is an annular ring.

16. A processing chamber comprising: a susceptor assembly for supporting a substrate; an inner upper electrode having a disk-shaped profile facing the base assembly and including a first top surface and a bottom surface connected by an outer surface, wherein the bottom surface includes an inclined bottom surface extending from a lower edge of the outer surface to a central protrusion; an outer upper electrode adjacent to the inner upper electrode, wherein the outer upper electrode comprises: forming a bottom surface; a second top surface having a radial width, wherein a middle portion of the second top surface has an elliptical shape; a cylindrical profile spanning the height of the outer upper electrode, wherein the middle portion of the second top surface defines a top of the cylindrical profile; an inner diameter surface connecting the second top surface and the shaped bottom surface, wherein the inner diameter surface includes a transition edge; an outer diameter surface connecting the second top surface and the shaped bottom surface; a convex protrusion of the shaped bottom surface that projects below the transition edge of the inner diameter surface, wherein the convex protrusion includes a protrusion lowest point located in the inner area of ​​the cylindrical profile, Wherein the outer upper electrode is an annular ring.

17. The outer upper electrode of claim 16, wherein the convex protrusion comprises: a downwardly sloping surface extending from the transition edge to the lowest point of the protrusion; as well as An upwardly inclined surface extends from the lowest point of the protrusion toward the cylindrical profile, wherein the cylindrical profile includes a plurality of center lines intersecting a plurality of radial lines extending from the central axis of the outer upper electrode, wherein each of the plurality of center lines intersects the middle portion of the second top surface.

18. The external upper electrode according to claim 17, wherein the downwardly inclined surface is a continuation of the inclined bottom surface at the lower edge of the outer surface of the inner upper electrode.

19. The external upper electrode according to claim 16, further comprising: a concave portion formed on the first side having an upwardly inclined surface extending from a lowest point of the protrusion toward the cylindrical profile, wherein the cylindrical profile includes a plurality of center lines intersecting a plurality of radial directions extending from a central axis of the outer upper electrode, wherein each of the plurality of center lines intersects the middle portion of the second top surface, Wherein the concave portion is located from the cylindrical profile towards the outer diameter surface.

20. The external upper electrode according to claim 19, further comprising: an extension protruding from the outer diameter surface, Wherein the extension is formed on the second side of the concave portion.

Images