Electrostatic chuck with spatially engineered radiofrequency power delivery electrode

Abstract

An electrostatic chuck includes a ceramic structure that has a top surface, a bottom surface, and a side surface extending between the top surface and the bottom surface. The top surface is configured to support a semiconductor wafer during a plasma-based fabrication process. The electrostatic chuck also includes a radiofrequency power delivery electrode embedded within the ceramic structure. The radiofrequency power delivery electrode includes a first portion positioned a first distance away from the top surface of the ceramic structure and a second portion positioned a second distance away from the top surface of the ceramic structure, where the second distance is different than the first distance.

Description

Electrostatic Chuck with Spatially Engineered Radiofrequency Power Delivery Electrode by inventorAnurag Kumar Mishra, Theodores Panagopoulos, Alexander Matyushkin, Ryan Bise, John Holland Background of the Invention

[0001] 1. Field of the Disclosure

[0002] The present disclosure relates to semiconductor device fabrication.

[0003] 2. Description of the Related Art

[0004] In the fabrication of semiconductor devices such as integrated circuits, memory cells, and the like, a series of manufacturing operations are performed to define features on a semiconductor wafer ("wafers" hereafter). The wafer includes integrated circuit devices in the form of multi-level structures defined on a silicon substrate. At a substrate level, transistor devices with diffusion regions are formed. In subsequent levels, interconnect metallization lines are patterned and electrically connected to the transistor devices to define a desired integrated circuit device. Also, patterned conductive layers are insulated from other conductive layers by dielectric materials.

[0005] Many modem semiconductor chip fabrication processes include generation of a plasma from which ions and / or radical constituents are derived for use in either directly or indirectly effecting a change on a surface of a substrate exposed to the plasma. For example, various plasma-based processes can be used to etch material from a substrate surface, deposit material onto a substrate surface, or modify a material already present on a substrate surface. The plasma is often generated by applying radiofrequency (RF) power to a process gas in a controlled environment, such that the process gas becomes energized and transforms into the desired plasma. The characteristics of the plasma are affected by many process parameters including, but not limited to, material composition of the process gas, flow rate of the process gas, geometric features of the plasma generation region and surrounding structures, temperatures of the process gas and surrounding materials, frequency of the RF power applied, magnitude of the RF power applied, and temporal manner in which the RF power is applied, among others. Therefore, it is of interest to understand, monitor, and / or control some of the process parameters that may affect the characteristics of the generated plasma, particularly with regard to generation and delivery of the RF power to the plasma generation region. Also, controlling and / or improving the uniformity of the plasma distribution across the surface of the wafer becomes more critical for improving the yield and reducing the cost of manufacturing / fabrication ofadvanced semiconductor chips, particularly as the critical feature size within the advanced semiconductor chips becomes smaller (single digit nanometer to sub-nanometer scale) and the performance of the advanced semiconductor chips becomes even more sensitive to process parameters. It is within this context that the present disclosure arises.Summary of the Invention

[0006] In an example embodiment, an electrostatic chuck is disclosed. The electrostatic chuck includes a ceramic structure that has a top surface, a bottom surface, and a side surface extending between the top surface and the bottom surface. The top surface is configured to support a semiconductor wafer during a plasma-based fabrication process. The electrostatic chuck also includes a radiofrequency power delivery electrode embedded within the ceramic structure. The radiofrequency power delivery electrode includes a first portion positioned a first distance away from the top surface of the ceramic structure and a second portion positioned a second distance away from the top surface of the ceramic structure, where the second distance is different than the first distance.

[0007] In an example embodiment, an electrostatic chuck is disclosed. The electrostatic chuck includes a ceramic structure that has a top surface, a bottom surface, and a side surface extending between the top surface and the bottom surface. The top surface is configured to support a semiconductor wafer during a plasma-based fabrication process. The electrostatic chuck also includes a plurality of radiofrequency power delivery electrodes embedded within the ceramic structure. The plurality of radiofrequency power delivery electrodes include a first electrode positioned a first distance away from the top surface of the ceramic structure and a second electrode positioned a second distance away from the top surface of the ceramic structure. The plurality of radiofrequency power delivery electrodes are physically separated from each other.

[0008] In an example embodiment, a method is disclosed for plasma processing of a semiconductor wafer. The method includes positioning a semiconductor wafer on a wafer support area of an electrostatic chuck. The electrostatic chuck includes a ceramic structure that has a top surface, a bottom surface, and a side surface extending between the top surface and the bottom surface. The top surface is configured to have the wafer support area. The electrostatic chuck includes a radiofrequency power delivery electrode embedded within the ceramic structure. The radiofrequency power delivery electrode includes a first portion positioned a first distance away from the top surface of the ceramic structure and a second portion positioned a second distance away from the top surface of the ceramic structure, where the second distance is different than the first distance. The method also includes supplying a process gas to a region overlying the semiconductor wafer. The method also includes supplying a radiofrequency powerto the radiofrequency power delivery electrode. The radiofrequency power transforms the process gas into a plasma within the region overlying the semiconductor wafer. The first distance between the first portion of the radiofrequency power delivery electrode and the top surface of the ceramic structure is sized to control one or more of a first voltage on a first portion of the semiconductor wafer overlying the first portion of the radiofrequency power delivery electrode, a first density of the plasma overlying the first portion of the semiconductor wafer, and a first ion flux incident upon the first portion of the semiconductor wafer, so as to minimize a difference between a first etch rate across the first portion of the semiconductor wafer and an average etch rate across an entirety of the semiconductor wafer. Also, the second distance between the second portion of the radiofrequency power delivery electrode and the top surface of the ceramic structure is sized to control one or more of a second voltage on a second portion of the semiconductor wafer overlying the second portion of the radiofrequency power delivery electrode, a second density of the plasma overlying the second portion of the semiconductor wafer, and a second ion flux incident upon the second portion of the semiconductor wafer, so as to minimize a difference between a second etch rate across the second portion of the semiconductor wafer and the average etch rate across the entirety of the semiconductor wafer.

[0009] In an example embodiment, a method is disclosed for plasma processing of a semiconductor wafer. The method includes positioning a semiconductor wafer on a wafer support area of an electrostatic chuck. The electrostatic chuck includes a ceramic structure that has a top surface, a bottom surface, and a side surface extending between the top surface and the bottom surface. The wafer support area is on the top surface. The electrostatic chuck includes a plurality of radiofrequency power delivery electrodes embedded within the ceramic structure. The plurality of radiofrequency power delivery electrodes are physically separated from each other. The plurality of radiofrequency power delivery electrodes include a first radiofrequency power delivery electrode positioned a first distance away from the top surface of the ceramic structure and a second radiofrequency power delivery electrode positioned a second distance away from the top surface of the ceramic structure, where the second distance is different than the first distance. The method also includes supplying a process gas to a region overlying the semiconductor wafer. The method also includes supplying a first radiofrequency power to the first radiofrequency power delivery electrode. The method also includes supplying a second radiofrequency power to the second radiofrequency power delivery electrode. The first radiofrequency power and the second radiofrequency power transform the process gas into a plasma within the region overlying the semiconductor wafer. The first distance between the first radiofrequency power delivery electrode and the top surface of the ceramic structure is sized tocontrol one or more of a first voltage on a first portion of the semiconductor wafer overlying the first radiofrequency power delivery electrode, a first density of the plasma overlying the first portion of the semiconductor wafer, and a first ion flux incident upon the first portion of the semiconductor wafer, so as to minimize a difference between a first etch rate across the first portion of the semiconductor wafer and an average etch rate across an entirety of the semiconductor wafer. Also, the second distance between the second radiofrequency power delivery electrode and the top surface of the ceramic structure is sized to control one or more of a second voltage on a second portion of the semiconductor wafer overlying the second radiofrequency power delivery electrode, a second density of the plasma overlying the second portion of the semiconductor wafer, and a second ion flux incident upon the second portion of the semiconductor wafer, so as to minimize a difference between a second etch rate across the second portion of the semiconductor wafer and the average etch rate across the entirety of the semiconductor wafer.

[0010] Other aspects and advantages of the embodiments disclosed herein will become more apparent from the following detailed description and the accompanying drawings.Brief Description of the Drawings

[0011] Figure 1A shows a vertical cross-section diagram of an example CCP processing system, in accordance with some embodiments of the present disclosure.

[0012] Figure IB shows a diagram of a control module that is configured and connected to control the CCP processing system, in accordance with some example embodiments.

[0013] Figure 1C shows several plots that illustrate the spatial correlation between radial etch rate uniformity across the semiconductor wafer and the radial RF power and voltage distributions across the semiconductor wafer, in accordance with some embodiments.

[0014] Figure 2A shows a vertical cross-section view of the electrostatic chuck with a downwardly curved RF power delivery electrode embedded within the electrostatic chuck, in accordance with some embodiments.

[0015] Figure 2B shows a top view of the RF power delivery electrode of Figure 2A, in accordance with some embodiments.

[0016] Figure 3A shows a vertical cross-section view of the electrostatic chuck with an upwardly curved RF power delivery electrode embedded within the electrostatic chuck, in accordance with some embodiments.

[0017] Figure 3B shows a top view of the RF power delivery electrode of Figure 3A, in accordance with some embodiments.

[0018] Figure 4A shows a vertical cross-section view of the electrostatic chuck with a multi-curved RF power delivery electrode embedded within the electrostatic chuck, in accordance with some embodiments.

[0019] Figure 4B shows a top view of the RF power delivery electrode of Figure 4A, in accordance with some embodiments.

[0020] Figure 5A shows a vertical cross-section view of the electrostatic chuck with a downwardly stepped RF power delivery electrode embedded within the electrostatic chuck, in accordance with some embodiments.

[0021] Figure 5B shows a top view of the RF power delivery electrode of Figure 5A, in accordance with some embodiments.

[0022] Figure 6A shows a vertical cross-section view of the electrostatic chuck with an upwardly stepped RF power delivery electrode embedded within the electrostatic chuck, in accordance with some embodiments.

[0023] Figure 6B shows a top view of the RF power delivery electrode of Figure 6A, in accordance with some embodiments.

[0024] Figure 7A shows a vertical cross-section view of the electrostatic chuck with a plurality of RF power delivery electrodes embedded within the electrostatic chuck, in accordance with some embodiments.

[0025] Figure 7B shows a top view of the plurality of RF power delivery electrodes of Figure 7 A, in accordance with some embodiments.

[0026] Figure 8A shows a vertical cross-section view of the electrostatic chuck with a plurality of RF power delivery electrodes embedded within the electrostatic chuck, in accordance with some embodiments.

[0027] Figure 8B shows a top view of the plurality of RF power delivery electrodes of Figure 8 A, in accordance with some embodiments.

[0028] Figure 9A shows a vertical cross-section view of the electrostatic chuck with a plurality of RF power delivery electrodes embedded within the electrostatic chuck, in accordance with some embodiments.

[0029] Figure 9B shows a top view of the plurality of RF power delivery electrodes of Figure 9 A, in accordance with some embodiments.

[0030] Figure 10A shows a vertical cross-section view of the electrostatic chuck with a plurality of RF power delivery electrodes embedded within the electrostatic chuck and respectively electrically connected to receive separately controlled RF powers, in accordance with some embodiments.

[0031] Figure 10B shows a top view of the plurality of RF power delivery electrodes of Figure10A, in accordance with some embodiments.

[0032] Figure 11 shows a flowchart of a method for plasma processing of the semiconductor wafer, in accordance with some embodiments.

[0033] Figure 12 shows a flowchart of a method for plasma processing of the semiconductor wafer, in accordance with some embodiments.Detailed Description of the Invention

[0034] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. It will be apparent, however, to one skilled in the art that embodiments of the present disclosure may be practiced without some or all of these specific details. In other instances, well known process operations have not been described in detail in order not to unnecessarily obscure the present disclosure.

[0035] In the semiconductor industry, semiconductor wafers / substrates ("semiconductor wafer" hereafter) can undergo plasma-based fabrication operations in a capacitively coupled plasma (CCP) processing chamber. Radiofrequency (RF) power is supplied to an electrode of the CCP processing chamber to energize a process gas within the CCP processing chamber so as to transform the process gas into a plasma within a plasma processing region within the CCP processing chamber to which the semiconductor wafer is exposed. Reactive species and / or charged species within the plasma interact with the semiconductor wafer to modify a condition of the semiconductor wafer, such as by modifying a material present on the semiconductor wafer, or by depositing material on the semiconductor wafer, or by removing / etching material from the semiconductor wafer, by way of example. In various embodiments, the CCP processing chamber is equipped with one or more RF power delivery electrodes that receive RF power for generating the plasma within the plasma processing region within the CCP processing chamber. Also, in various embodiments, the CCP processing chamber is equipped with one or more bias electrodes that receive RF power and / or direct current (DC) power to generate a bias voltage at the semiconductor wafer location for attracting charged species from the plasma toward the semiconductor wafer. In some embodiments, the RF power delivery electrode(s) and the bias electrode(s) are implemented within an electrostatic chuck on which the semiconductor wafer is supported within the CCP processing chamber. Also, in some embodiments, the electrostatic chuck includes one or more clamping electrodes to which DC and / or AC power is supplied to generate an electrostatic field that holds the semiconductor wafer within a wafer support area on the top surface of the electrostatic chuck.

[0036] Figure 1A shows a vertical cross-section diagram of an example CCP processing system 100, in accordance with some embodiments of the present disclosure. The CCP processingsystem 100 includes a chamber 101 within which a plasma processing region 102 exists. Within the plasma processing region 102, a plasma 123 (represented by the region within the dashed line) is generated in exposure to a semiconductor wafer 105 to effect a change to the semiconductor wafer 105 in a controlled manner. In various fabrication processes, the change to the semiconductor wafer 105 can be a change in material or surface condition on the semiconductor wafer 105. For example, in various fabrication processes, the change to the semiconductor wafer 105 can include one or more of etching of a material from the semiconductor wafer 105, deposition of a material on the semiconductor wafer 105, or modification of material present on the semiconductor wafer 105. In various embodiments, the semiconductor wafer 105 can be essentially any type of substrate that is subjected to a plasmabased fabrication process. For example, in some embodiments, the semiconductor wafer 105 as referred to herein can be a substrate formed of silicon, sapphire, GaN, GaAs or SiC, or other substrate materials, and can include glass panels / substrates, metal foils, metal sheets, polymer materials, or the like. Also, in various embodiments, the semiconductor wafer 105 as referred to herein may vary in form, shape, and / or size. For example, in some embodiments, the semiconductor wafer 105 referred to herein may correspond to a 200 mm (millimeters) diameter semiconductor wafer, a 300 mm diameter semiconductor wafer, or a 450 mm diameter semiconductor wafer, among other semiconductor wafer sizes. Also, in some embodiments, the semiconductor wafer 105 referred to herein may correspond to a non-circular substrate, such as a rectangular substrate for a flat panel display, or the like, among other shapes.

[0037] The plasma processing region 102 within the CCP processing chamber 101 is connected to a process gas supply system 104, such that one or more process gas(es) can be supplied in a controlled manner to the plasma processing region 102, as represented by line 106. It should be understood that the process gas supply system 104 includes one or more process gas sources and an arrangement of valves and mass flow controllers to enable provision of the one or more process gas(es) to the plasma processing region 102 with a controlled flow rate and with a controlled flow time. Also, in various embodiments, the one or more process gas(es) are delivered to the plasma processing region 102 in both a temporally controlled manner and a spatially controlled manner relative to the semiconductor wafer 105. In various embodiments, the CCP processing system 100 operates by having the process gas supply system 104 deliver one or more process gases into the plasma processing region 102, and by applying RF power to the one or more process gases to transform the one or more process gases into the plasma 123 in exposure to the semiconductor wafer 105, in order to cause a change in material or surface condition on the semiconductor wafer 105.

[0038] The CCP processing chamber 101 includes an electrostatic chuck 103 upon which the semiconductor wafer 105 is positioned and supported during processing operations. In some embodiments, an RF power delivery electrode 107 is disposed within the electrostatic chuck 103 to provide for transmission of RF power from the RF power delivery electrode 107 through the plasma processing region 102 to generate the plasma 123 and / or control ion energy. The RF power delivery electrode 107 is connected to receive RF power through an RF feed structure 109, which is connected to one or more RF power generator(s) 111 by way of one or more impedance matching system(s) 113. The RF feed structure 109 is an electrically conductive member. In some embodiments, the RF feed structure 109 includes an electrically conductive rod and / or an electrically conductive plate. The impedance matching system(s) 113 include an arrangement of capacitors and inductors configured to ensure that an impedance seen by the RF power generator(s) 111 at the input of the impedance matching system(s) 113 is sufficiently close to an output impedance for which the RF power generator(s) 111 is designed to operate (usually 50 Ohm), so that RF power generated and transmitted by the RF power generator(s) 111 will be transmitted into the plasma processing region 102 in an efficient manner, e.g., without adverse reflection.

[0039] Also, in some embodiments, the CCP processing chamber 101 includes an upper electrode 115. In various embodiments, the upper electrode 115 can provide either an electrical ground electrode or can be used to transmit additional RF power into the plasma processing region 102. For example, in some embodiments, the upper electrode 115 is connected to a reference ground potential 108, such that the upper electrode 115 provides a return path for RF signals transmitted into the plasma processing region 102 from the RF power delivery electrode 107. Alternatively, in some embodiments, the upper electrode 115 is connected to receive RF power through an RF feed structure 117, which is connected to one or more RF power generator(s) 121 by way of one or more impedance matching system(s) 119. The impedance matching system(s) 119 include an arrangement of capacitors and inductors configured to ensure that an impedance seen by the RF power generator(s) 121 at the input of the impedance matching system(s) 119 is sufficiently close to an output impedance for which the RF powers generator(s) 121 is designed to operate (usually 50 Ohm), so that RF power generated and transmitted by the RF power generator(s) 121 will be transmitted into the plasma processing region 102 in an efficient manner, e.g., without adverse reflection.

[0040] In some embodiments, one or more clamping electrode(s) 125 are disposed within the electrostatic chuck 103 to generate an electrostatic field for holding the semiconductor wafer 105 on the electrostatic chuck 103. The clamping electrode(s) 125 are electrically connected toreceive electrical power through an electrical connection 127, where the electrical power is supplied from a power supply 131 through an electrical connection 137 to an RF filter 129, and through the RF filter 129 to the electrical connection 127. In some embodiments, the power supply 131 is an alternating current (AC) power supply. In some embodiments, the power supply 131 is a direct current (DC) power supply. In some embodiments, the clamping electrode(s) 125 include multiple interleaved electrodes positioned just under the top surface of the electrostatic chuck 103. The RF filter 129 is configured to prevent RF power from entering the power supply 131, while allowing transmission of electrical current between the power supply 131 and the electrical connection 127.

[0041] Also, in some embodiments, a bias voltage control system 165 is connected through an electrical connection 139 to one or more bias voltage electrode(s) 141 disposed within the electrostatic chuck 103 to control a bias voltage present on the top surface of the semiconductor wafer 105. The bias voltage can be controlled to attract charged constituents of the plasma 123, e.g., ions, toward the semiconductor wafer 105 and thereby control energy and directionality of the charged constituents of the plasma 123. For example, the bias voltage control system 165 can be operated to accelerate ions in the plasma 123 toward the semiconductor wafer 105 to perform an anisotropic etch on the semiconductor wafer 105.

[0042] Figure IB shows a diagram of a control module 163 that is configured and connected to control the CCP processing system 100, in accordance with some example embodiments. The control module 163 includes a processor 181, a storage hardware unit (HU) 183 (e.g., memory), an input HU 171, an output HU 175, an input / output (RO) interface 173, an RO interface 177, a network interface controller (NIC) 179, and a data communication bus 185. The processor 181, the storage HU 183, the input HU 171, the output HU 175, the RO interface 173, the RO interface 177, and the NIC 179 are in data communication with each other by way of the data communication bus 185. Examples of the input HU 171 include a mouse, a keyboard, a stylus, a data acquisition system, a data acquisition card, etc. Examples of the output HU 175 include a display, a speaker, a device controller, etc. Examples of the NIC 179 include a network interface card, a network adapter, etc. In various embodiments, the NIC 179 is configured to operate in accordance with one or more communication protocols and associate physical layers, such as Ethernet and / or EtherCAT, among others. Each of the RO interfaces 173 and 177 is defined to provide compatibility between different hardware units coupled to the RO interface. For example, the RO interface 173 can be defined to convert a signal received from the input HU 171 into a form, amplitude, and / or speed compatible with the data communication bus 185. Also, the RO interface 177 can be defined to convert a signal received from the data communicationbus 185 into a form, amplitude, and / or speed compatible with the output HU 175. Although various operations described herein are performed by the processor 181 of the control module 163, it should be understood that in some embodiments various operations can be performed by multiple processors of the control module 163 and / or by multiple processors of multiple computing systems connected to the control module 163.

[0043] Achieving radial etch rate uniformity across the semiconductor wafer 105 in plasmabased dielectric etching processes continues to challenge the semiconductor fabrication industry. Experimental tests and theoretical investigations have demonstrated that the radial etch rate distribution profile is strongly correlated to radial radiofrequency power deposition within the plasma 123. The radial RF power deposition within the plasma 123 determines the ion energy distribution and discharge density profile within the plasma 123. A probable root cause for not having adequate radial etch rate uniformity across the semiconductor wafer 105 is a lack of sufficiently precise control of radial voltage distribution (and corresponding ionic delivery to discharge) across the semiconductor wafer 105. Therefore, it is of interest to provide for control of the radial voltage distribution across the semiconductor wafer 105.

[0044] Figure 1C shows several plots that illustrate the spatial correlation between radial etch rate uniformity across the semiconductor wafer 105 and the radial RF power and voltage distributions across the semiconductor wafer 105, in accordance with some embodiments. A flat curve 191 represents a desired radial etch rate distribution across the semiconductor wafer 105. Specifically, the objective is to have a substantially equal etch rate at each portion of the semiconductor wafer 105 where semiconductor dies are fabricated. A curve 193 represents a typical RF power / voltage distribution across the semiconductor wafer 105 that is obtained using a substantially flat RF power delivery electrode 107. A curve 195 represents a typical etch rate distribution (profile) across the semiconductor wafer 105. The curve 195 shows that the etch rate distribution across the semiconductor wafer 105 is strongly correlated to the RF power / voltage distribution across the semiconductor wafer 105. A curve 197 represents a modified RF power / voltage distribution across the semiconductor wafer 105 that would serve to move the etch rate distribution across the semiconductor wafer 105 from what is depicted by the curve 195 to what is depicted by the curve 191. Figure 1C indicates that spatial control of the RF power / voltage distribution across the semiconductor wafer 105, i.e., across a top surface 103T of the electrostatic chuck 103, can be effective in obtaining a more desirable (flatter) etch rate distribution across the semiconductor wafer 105.

[0045] Various embodiments are disclosed here for reconfiguring and controlling the RF power delivery electrode 107 to in turn spatially control the RF power / voltage distribution across thesemiconductor wafer 105, i.e., across a top surface 103T of the electrostatic chuck 103, to obtain a more desirable (flatter) etch rate distribution across the semiconductor wafer 105. In some embodiments, the shape of the RF power delivery electrode 107 that is embedded within the electrostatic chuck 103 is defined to improve the plasma density and obtain a more uniform etch rate across the semiconductor wafer 105. More specifically, in some embodiments, the shape of the RF power delivery electrode 107 is configured in a non-flat manner so that different portions of the RF power delivery electrode 107 are closer to or farther away from the top surface 103T of the electrostatic chuck 103 relative to other portions of the RF power delivery electrode 107, so as to affect (either increase or decrease) the amount of RF power delivered to local portions of the plasma 123 and correspondingly affect (either increase or decrease) the local voltages on the semiconductor wafer 105, which in turn affects (either increases or decreases) the local etch rates on the semiconductor wafer 105.

[0046] Generally speaking, the density of the plasma 123 (ion flux) can be modulated with a change in the shape of the RF power delivery electrode 107 from what is conventionally a flat shape. The etch rate at a given location on the semiconductor wafer 105 is proportional to the ion flux at the given location on the semiconductor wafer 105. Therefore, the etch rate at a given location on the semiconductor wafer 105 can be modulated by the shape of the RF power delivery electrode 107 at the given location on the semiconductor wafer 105. More specifically, a smaller distance between a portion of the RF power delivery electrode 107 and the top surface 103T of the electrostatic chuck 103 provides for a locally higher density of the plasma 123 overlying the portion of the RF power delivery electrode 107, a correspondingly higher voltage on the semiconductor wafer 105 overlying the portion of the RF power delivery electrode 107, and a correspondingly higher etch rate on the semiconductor wafer 105 overlying the portion of the RF power delivery electrode 107. Therefore, by forming the RF power delivery electrode 107 into a particular shape it is possible to spatially and locally modulate the density of the plasma 123 at the sheath boundary between the plasma 123 and the top surface of the semiconductor wafer 105 so as to mitigate etch rate non-uniformity across the top surface of the semiconductor wafer 105, or perhaps even achieve a substantially uniform etch rate across an entirety of the top surface of the semiconductor wafer 105. Also, the shaped, i.e., non-flat, RF power delivery electrode 107 has very little to no effect on the plasma 123 sheath thickness between the bulk plasma 123 and the top surface of the semiconductor wafer 105, as compared with the plasma 123 sheath thickness that is present when using the flat RF power delivery electrode 107. Because the ions entering the plasma 123 sheath with Bohm velocity will have the same direction, there will be essentially no impact on the etched feature profile due to localmodulation of the plasma 123 density by way of the shaped, i.e., non-flat, RF power delivery electrode 107. Therefore, the etched feature profile is effectively decoupled from the plasma 123 density modulation that is done by way of the non-flat shape of the RF power delivery electrode 107.

[0047] Additionally, in some embodiments, the RF power delivery electrode 107 that is embedded within the electrostatic chuck 103 is segmented into a plurality of physically separate portions that are independently positioned with respect to the top surface 103T of the electrostatic chuck 103. As mentioned above, the proximity of each portion of the RF power delivery electrode 107 to the top surface 103T of the electrostatic chuck 103 controls a spatially corresponding local density of the plasma 123, which in turn controls a spatially corresponding voltage on the semiconductor wafer 105, which in turn controls a spatially corresponding etch rate on the semiconductor wafer 105. In some embodiments, a substantially equal amount of RF power is delivered to each of the plurality of physically separate portions of the segmented RF power delivery electrode 107. In these embodiments, the spatial relationships between the plurality of physically separate portions of the segmented RF power delivery electrode 107 and the top surface 103T of the electrostatic chuck 103 serve to control the radial distributions of the plasma 123 density, the voltage, and the etch rate over the semiconductor wafer 105. However, in some embodiments, separately controlled amounts of RF power are respectively delivered to the plurality of physically separate portions of the segmented RF power delivery electrode 107. In these embodiments, control of the radial distributions of the plasma 123 density, the voltage, and the etch rate over the semiconductor wafer 105 is provided by both the spatial relationships between the plurality of physically separate portions of the segmented RF power delivery electrode 107 and the top surface 103T of the electrostatic chuck 103, and the separately controlled amounts of RF power that are respectively delivered to the plurality of physically separate portions of the segmented RF power delivery electrode 107.

[0048] Figure 2A shows a vertical cross-section view of the electrostatic chuck 103 with a downwardly curved RF power delivery electrode 107A embedded within the electrostatic chuck 103, in accordance with some embodiments. Figure 2B shows a top view of the RF power delivery electrode 107A, in accordance with some embodiments. The electrostatic chuck 103 includes a ceramic structure 103C that has a top surface 103T, a bottom surface 103B, and a side surface 103S extending between the top surface 103T and the bottom surface 103B. In some embodiments, the side surface 103S extends in a substantially linear manner between the top surface 103T and the bottom surface 103B. In some embodiments, the side surface 103S extends in a stepped configuration or non-linear configuration between the top surface 103T and thebottom surface 103B. In some embodiments, the ceramic structure 103C is formed as a combination of ceramic sub-structures, such that the overall ceramic structure 103C is a unitary structure. The top surface 103T is configured to support the semiconductor wafer 105 during performance of a plasma-based fabrication process within the plasma processing region 102 within the chamber 101. It should be understood that the electrostatic chuck 103 includes other components that are not explicitly shown in the example of Figure 2A in order to avoid obscuring description of the embodiments herein.

[0049] The RF power delivery electrode 107 A is embedded within the ceramic structure 103C. More specifically, the ceramic structure 103C includes an upper portion 250 present between the RF power delivery electrode 107 A and the top surface 103T of the ceramic structure 103C. The ceramic structure 103C also includes a lower portion 251 present between the RF power delivery electrode 107 A and the bottom surface 103B of the ceramic structure 103C. In various embodiments, one or both of the upper portion 250 and the lower portion 251 of the ceramic structure 103C may include one or more components and / or devices applicable to operation of the electrostatic chuck 103, such as the one or more clamping electrode(s) 125, the one or more bias voltage electrode(s) 141, one or more cooling gas supply channels, one or more RF conveyance structures, and / or other components / devices.

[0050] The RF power delivery electrode 107A includes a first portion 221 that is positioned a first distance 203 away from the top surface 103T of the ceramic structure 103C and a second portion 223 that is positioned a second distance away 205 from the top surface 103T of the ceramic structure 103C. The second distance 205 is different than the first distance 203. In some embodiments, the first portion 221 of the RF power delivery electrode 107A is positioned at a radial center location 202 of the ceramic structure 103C, and the second portion 223 of the RF power delivery electrode 107A is positioned at a radial peripheral location 204 of the ceramic structure 103C. The RF power delivery electrode 107 A has a uniform configuration in an azimuthal direction 241 about a reference line 201 extending perpendicularly through a radial center location of the top surface 103T of the ceramic structure 103C. In the example embodiment of Figure 2 A, the second distance 205 is greater than the first distance 203. The RF power delivery electrode 107A is configured to curve away from the top surface 103T of the ceramic structure 103C in a radial direction 242 extending from the first portion 221 of the RF power delivery electrode 107 A to the second portion 223 of the RF power delivery electrode 107A. In this manner, the RF power delivery electrode 107A has a circular dome shape with the center of the circular dome shaped closer to the top surface 103T of the ceramic structure 103C than the outer radial perimeter of the circular dome shape.

[0051] The electrostatic chuck 103 includes a baseplate 207 positioned within the ceramic structure 103C at a location between the RF power delivery electrode 107A and the bottom surface 103B of the ceramic structure 103C. The electrostatic chuck 103 includes a number of electrically conductive structures 209-1 through 209-xl (where xl is an integer value greater than zero) extending between the baseplate 207 and the RF power delivery electrode 107 A at a number of locations within a peripheral region of the ceramic structure 103C. The example embodiment of Figures 2A-2B shows eight electrically conductive structures 209-1 through 209- 8. However, it should be understood that in various embodiments, the number xl of electrically conductive structures 209-1 through 209-xl can be either less than or greater than eight. The locations of the electrically conductive structures 209-1 through 209-xl are azimuthally spaced apart in the azimuthal direction 241 about a reference line 201 extending perpendicularly through the center location 202 of the top surface 103T of the ceramic structure 103C. In some embodiments, the electrically conductive structures 209-1 through 209-xl are substantially equally spaced apart in the azimuthal direction 241. However, in some embodiments, the spacings between neighboring ones of the electrically conductive structures 209-1 through 209- xl can vary in the azimuthal direction 241. In some embodiments, the electrically conductive structures 209-1 through 209-xl are positioned near the periphery of the ceramic structure 103C so that the RF power is conveyed around an internal volume of the electrostatic chuck 103 between the baseplate 207 and the RF power delivery electrode 107A, so as to avoid adverse coupling of RF power into various other components present within the internal volume of the electrostatic chuck 103. Also, in some embodiments, symmetrical uniformity in radial and azimuthal positioning of the electrically conductive structures 209-1 through 209-xl about the center location 202 of the ceramic structure 103C is implemented to provide for symmetrical conveyance of RF power from the RF power delivery electrode 107 A through the top surface 103T of the ceramic structure 103C.

[0052] The RF power supply structure 109 extends from the baseplate 207 to a location outside of the ceramic structure 103C. The RF power supply structure 109 is connected to the RF power generator(s) 111 by way of the impedance matching system(s) 113. In this manner, RF power is supplied to the RF power delivery electrode 107 A through the baseplate 207 and the electrically conductive structures 209-1 through 209-xl. In some alternative embodiments, the baseplate 207 is not present in the ceramic structure 103C, and the electrically conductive structures 209-1 through 209-xl are configured / extended to be exposed for electrical connection at the outer surface, e.g., bottom, of the ceramic structure 103C. In these alternative embodiments, each of the electrically conductive structures 209-1 through 209-xl is electrically connected to the RFpower supply structure 109 outside of the ceramic structure 103C, such that each of the electrically conductive structures 209-1 through 209-xl is electrically connected to the RF power generator(s) 111 by way of the impedance matching system(s) 113. In these alternative embodiments, RF power is supplied to the RF power delivery electrode 107A through the electrically conductive structures 209-1 through 209-xl without being transmitted through the baseplate 207.

[0053] The sizes of the first distance 203 and the second distance 205, and the corresponding shape of the RF power delivery electrode 107 A and proximity of the RF power delivery electrode 107A to the top surface 103T of the ceramic structure 103C, are set to achieve a particular plasma 123 response, e.g., ion energy distribution and / or discharge density profile, when RF power is supplied to the RF power delivery electrode 107A during a plasma-based etching process, where the particular plasma 123 response provides for improved etch rate uniformity across the semiconductor wafer 105. More specifically, the sheath voltage on the semiconductor wafer 105 overlying portions of the RF power delivery electrode 107A that are closer to the top surface 103T of the ceramic structure 103C will be greater than the sheath voltage on the semiconductor wafer 105 overlying portions of the RF power delivery electrode 107 A that are farther from the top surface 103T of the electrostatic chuck. The energy of the ions that are incident upon a given portion of the semiconductor wafer 105 is directly proportional to the sheath voltage on the given portion of the semiconductor wafer 105. Therefore, a higher sheath voltage corresponds to higher energy ions, and vice-versa. The etch rate on a given portion of the semiconductor wafer 105 is directly proportional to both the energy of the ions incident upon the given portion of the semiconductor wafer 105 and the plasma 123 density above the given portion of the semiconductor wafer 105. Therefore, higher energy ions correspond to higher etch rates, and vice-versa. Thus, a higher sheath voltage corresponds to a higher etch rate, and vice-versa. Thus, a closer position of the RF power delivery electrode 107A to the top surface 103T of the ceramic structure 103C corresponds to a higher etch rate, and vice-versa.

[0054] Figure 3A shows a vertical cross-section view of the electrostatic chuck 103 with an upwardly curved RF power delivery electrode 107B embedded within the electrostatic chuck 103, in accordance with some embodiments. Figure 3B shows a top view of the RF power delivery electrode 107B, in accordance with some embodiments. The electrostatic chuck 103 includes the ceramic structure 103C that has the top surface 103T, the bottom surface 103B, and the side surface 103S extending between the top surface 103T and the bottom surface 103B, as described above with regard to Figure 2A. It should be understood that the electrostatic chuck 103 includes other components that are not explicitly shown in the example of Figure 3 A inorder to avoid obscuring description of the embodiments herein.

[0055] The RF power delivery electrode 107B is embedded within the ceramic structure 103C. More specifically, the ceramic structure 103C includes an upper portion 350 present between the RF power delivery electrode 107B and the top surface 103T of the ceramic structure 103C. The ceramic structure 103C also includes a lower portion 351 present between the RF power delivery electrode 107B and the bottom surface 103B of the ceramic structure 103C. In various embodiments, the upper portion 350 of the ceramic structure 103C includes one or more components and / or devices applicable to operation of the electrostatic chuck 103, such as the one or more clamping electrode(s) 125, the one or more bias voltage electrode(s) 141, cooling gas supply channels, and / or other components / devices. Similarly, in various embodiments, the lower portion 351 of the ceramic structure 103C includes one or more components and / or devices applicable to operation of the electrostatic chuck 103, such as one or more RF conveyance structures, one or more cooling gas supply channels, and / or other components / devices .

[0056] The RF power delivery electrode 107B includes a first portion 321 that is positioned a first distance 301 away from the top surface 103T of the ceramic structure 103C and a second portion 323 that is positioned a second distance away 303 from the top surface 103T of the ceramic structure 103C. The second distance 303 is different than the first distance 301. In some embodiments, the first portion 321 of the RF power delivery electrode 107B is positioned at the radial peripheral location 204 of the ceramic structure 103C, and the second portion 323 of the RF power delivery electrode 107B is positioned at the radial center location 202 of the ceramic structure 103C. The RF power delivery electrode 107B has a uniform configuration in the azimuthal direction 241 about the reference line 201 extending perpendicularly through the radial center location of the top surface 103T of the ceramic structure 103C. In the example embodiment of Figure 3 A, the second distance 303 is greater than the first distance 301. The RF power delivery electrode 107B is configured to curve toward the top surface 103T of the ceramic structure 103C in the radial direction 242 extending from the second portion 323 of the RF power delivery electrode 107B to the first portion 321 of the RF power delivery electrode 107A. In this manner, the RF power delivery electrode 107B has a circular dish shape with the center of the circular dish shape farther from to the top surface 103T of the ceramic structure 103C than the outer radial perimeter of the circular dish shape.

[0057] The electrostatic chuck 103 of Figure 3 A includes the baseplate 207 positioned within the ceramic structure 103C at a location between the RF power delivery electrode 107B and the bottom surface 103B of the ceramic structure 103C. The electrostatic chuck 103 includes anumber of electrically conductive structures 305-1 through 305-x2 (where x2 is an integer value greater than zero) extending between the baseplate 207 and the RF power delivery electrode 107B at a number of locations within a peripheral region of the ceramic structure 103C. The example embodiment of Figures 3A-3B shows eight electrically conductive structures 305-1 through 305-8. However, it should be understood that in various embodiments, the number x2 of electrically conductive structures 305-1 through 305-x2 can be either less than or greater than eight. The locations of the electrically conductive structures 305-1 through 305-x2 are azimuthally spaced apart in the azimuthal direction 241 about the reference line 201 extending perpendicularly through the center location 202 of the top surface 103T of the ceramic structure 103C. In some embodiments, the electrically conductive structures 305-1 through 305-x2 are substantially equally spaced apart in the azimuthal direction 241.

[0058] The RF power supply structure 109 extends from the baseplate 207 to a location outside of the ceramic structure 103C, with the RF power supply structure 109 connected to the RF power generator(s) 111 by way of the impedance matching system(s) 113. In this manner, RF power is supplied to the RF power delivery electrode 107B through the baseplate 207 and the electrically conductive structures 305-1 through 305-x2. In some alternative embodiments, the baseplate 207 is not present in the ceramic structure 103C, and the electrically conductive structures 305-1 through 305-x2 are configured / extended to be exposed for electrical connection at the outer surface, e.g., bottom, of the ceramic structure 103C. In these alternative embodiments, each of the electrically conductive structures 305-1 through 305-x2 is electrically connected to the RF power supply structure 109 outside of the ceramic structure 103C, such that each of the electrically conductive structures 305-1 through 305-x2 is electrically connected to the RF power generator(s) 111 by way of the impedance matching system(s) 113. In these alternative embodiments, RF power is supplied to the RF power delivery electrode 107B through the electrically conductive structures 305-1 through 305-x2 without being transmitted through the baseplate 207.

[0059] The sizes of the first distance 301 and the second distance 303, and the corresponding shape of the RF power delivery electrode 107B and proximity of the RF power delivery electrode 107B to the top surface 103T of the ceramic structure 103C, are set to achieve a particular plasma 123 response, e.g., ion energy distribution and / or discharge density profile, when RF power is supplied to the RF power delivery electrode 107B during a plasma-based etching process, where the particular plasma 123 response provides for improved etch rate uniformity across the semiconductor wafer 105. More specifically, the sheath voltage on the semiconductor wafer 105 overlying portions of the RF power delivery electrode 107B that are closer to the top surface103T of the ceramic structure 103C will be greater than the sheath voltage on the semiconductor wafer 105 overlying portions of the RF power delivery electrode 107B that are farther from the top surface 103T of the electrostatic chuck. Therefore, a closer position of the RF power delivery electrode 107B to the top surface 103T of the ceramic structure 103C corresponds to a higher etch rate, and vice-versa.

[0060] Figure 4A shows a vertical cross-section view of the electrostatic chuck 103 with a multicurved RF power delivery electrode 107C embedded within the electrostatic chuck 103, in accordance with some embodiments. Figure 4B shows a top view of the RF power delivery electrode 107C, in accordance with some embodiments. The electrostatic chuck 103 includes the ceramic structure 103C that has the top surface 103T, the bottom surface 103B, and the side surface 103S extending between the top surface 103T and the bottom surface 103B, as described above with regard to Figure 2A. It should be understood that the electrostatic chuck 103 includes other components that are not explicitly shown in the example of Figure 4A in order to avoid obscuring description of the embodiments herein.

[0061] The RF power delivery electrode 107C is embedded within the ceramic structure 103C. The ceramic structure 103C includes an upper portion 450 present between the RF power delivery electrode 107C and the top surface 103T of the ceramic structure 103C. The ceramic structure 103C also includes a lower portion 451 present between the RF power delivery electrode 107C and the bottom surface 103B of the ceramic structure 103C. In various embodiments, the upper portion 450 of the ceramic structure 103C includes one or more components and / or devices applicable to operation of the electrostatic chuck 103, such as the one or more clamping electrode(s) 125, the one or more bias voltage electrode(s) 141, cooling gas supply channels, and / or other components / devices. Similarly, in various embodiments, the lower portion 451 of the ceramic structure 103C includes one or more components and / or devices applicable to operation of the electrostatic chuck 103, such as one or more RF conveyance structures, one or more cooling gas supply channels, and / or other components / devices .

[0062] The RF power delivery electrode 107C includes multiple portions respectively positioned at different distances 401-1 through 401-x3 (where x3 is an integer greater than one) away from the top surface 103T of the ceramic structure 103C. More specifically, the RF power delivery electrode 107C is configured to have multiple variations in distance 401-1 through 401- x3 from the top surface 103T of the ceramic structure 103C as a function of radial distance from the center reference line 201. Also, the distance of the RF power delivery electrode 107C from the top surface 103T of the ceramic structure 103C varies smoothly as a function of radialdistance from the center reference line 201, such that the RF power delivery electrode 107C is configured to curve away from the top surface 103T of the ceramic structure 103C and back toward the top surface 103T of the ceramic structure 103C along the radial direction 242 extending radially outward from the radial center location 202 of the ceramic structure 103C. Also, the RF power delivery electrode 107C has a uniform configuration in the azimuthal direction 241 about the center reference line 201. In this manner, the RF power delivery electrode 107C has a concentric wave shape in the radial direction 242 extending radially outward from the center reference line 201. The vertical cross-section profile of the RF power delivery electrode 107C includes three local peaks corresponding to distances 401-1, 401-3, and 401-5, and two local troughs corresponding to distances 401-2 and 401-5, by way of example. It should be understood that in various embodiments the RF power delivery electrode 107C can be configured to have any number greater than or equal to two of local peaks with intervening local troughs.

[0063] The electrostatic chuck 103 of Figure 4A includes the baseplate 207 positioned within the ceramic structure 103C at a location between the RF power delivery electrode 107C and the bottom surface 103B of the ceramic structure 103C. The electrostatic chuck 103 includes a number of electrically conductive structures 403-1 through 403-x4 (where x4 is an integer value greater than zero) extending between the baseplate 207 and the RF power delivery electrode 107C at a number of locations within a peripheral region of the ceramic structure 103C. The example embodiment of Figures 4A-4B shows eight electrically conductive structures 403-1 through 403-8. However, it should be understood that in various embodiments, the number x4 of electrically conductive structures 403-1 through 403-x4 can be either less than or greater than eight. The locations of the electrically conductive structures 403-1 through 403-x4 are azimuthally spaced apart in the azimuthal direction 241 about the reference line 201 that extends perpendicularly through the center location 202 of the top surface 103T of the ceramic structure 103C. In some embodiments, the electrically conductive structures 403-1 through 403-x4 are substantially equally spaced apart in the azimuthal direction 241.

[0064] The RF power supply structure 109 extends from the baseplate 207 to a location outside of the ceramic structure 103C, with the RF power supply structure 109 connected to the RF power generator(s) 111 by way of the matching system(s) 113. In this manner, RF power is supplied to the RF power delivery electrode 107C through the baseplate 207 and the electrically conductive structures 403-1 through 403-x4. In some alternative embodiments, the baseplate 207 is not present in the ceramic structure 103C, and the electrically conductive structures 403-1 through 403-x4 are configured / extended to be exposed for electrical connection at the outersurface, e.g., bottom, of the ceramic structure 103C. In these alternative embodiments, each of the electrically conductive structures 403-1 through 403-x4 is electrically connected to the RF power supply structure 109 outside of the ceramic structure 103C, such that each of the electrically conductive structures 403-1 through 403-x4 is electrically connected to the RF power generator(s) 111 by way of the impedance matching system(s) 113. In these alternative embodiments, RF power is supplied to the RF power delivery electrode 107C through the electrically conductive structures 403-1 through 403-x4 without being transmitted through the baseplate 207.

[0065] The sizes of the distances 401-1 through 401-x3, and the corresponding shape of the RF power delivery electrode 107C and proximity of the RF power delivery electrode 107C to the top surface 103T of the ceramic structure 103C, are set to achieve a particular plasma 123 response, e.g., ion energy distribution and / or discharge density profile, when RF power is supplied to the RF power delivery electrode 107C during a plasma-based etching process, where the particular plasma 123 response provides for improved etch rate uniformity across the semiconductor wafer 105. More specifically, the sheath voltage on the semiconductor wafer 105 overlying portions of the RF power delivery electrode 107C that are closer to the top surface 103T of the ceramic structure 103C will be greater than the sheath voltage on the semiconductor wafer 105 overlying portions of the RF power delivery electrode 107C that are farther from the top surface 103T of the electrostatic chuck. Therefore, a closer position of the RF power delivery electrode 107C to the top surface 103T of the ceramic structure 103C corresponds to a higher etch rate, and vice-versa.

[0066] Figure 5A shows a vertical cross-section view of the electrostatic chuck 103 with a downwardly stepped RF power delivery electrode 107D embedded within the electrostatic chuck 103, in accordance with some embodiments. Figure 5B shows a top view of the RF power delivery electrode 107D, in accordance with some embodiments. The electrostatic chuck 103 includes the ceramic structure 103C that has the top surface 103T, the bottom surface 103B, and the side surface 103S extending between the top surface 103T and the bottom surface 103B, as described above with regard to Figure 2A. It should be understood that the electrostatic chuck 103 includes other components that are not explicitly shown in the example of Figure 5A in order to avoid obscuring description of the embodiments herein.

[0067] The RF power delivery electrode 107D is embedded within the ceramic structure 103C. More specifically, the ceramic structure 103C includes an upper portion 550 present between the RF power delivery electrode 107D and the top surface 103T of the ceramic structure 103C. The ceramic structure 103C also includes a lower portion 551 present between the RF power deliveryelectrode 107D and the bottom surface 103B of the ceramic structure 103C. In various embodiments, the upper portion 550 of the ceramic structure 103C includes one or more components and / or devices applicable to operation of the electrostatic chuck 103, such as the one or more clamping electrode(s) 125, the one or more bias voltage electrode(s) 141, cooling gas supply channels, and / or other components / devices. Similarly, in various embodiments, the lower portion 551 of the ceramic structure 103C includes one or more components and / or devices applicable to operation of the electrostatic chuck 103, such as one or more RF conveyance structures, one or more cooling gas supply channels, and / or other components / devices .

[0068] The RF power delivery electrode 107D includes a plurality of portions 107D-1 through 107D-x5 (where x5 is an integer greater than one) positioned at respective and different vertical distances away from the top surface 103T of the ceramic structure 103C. The example RF power delivery electrode 107D includes three portions 107D-1 through 107D-3. The first portion 107D- 1 is positioned a first distance 501 away from the top surface 103T of the ceramic structure 103C. The second portion 107D-2 is positioned a second distance 503 away from the top surface 103T of the ceramic structure 103C. The third portion 107D-3 is positioned a third distance 505 away from the top surface 103T of the ceramic structure 103C. The second distance 503 is different than the first distance 501. The third distance 505 is different than each of the first distance 501 and the second distance 503. The RF power delivery electrode 107D is configured to step away from the top surface 103T of the ceramic structure 103C in the radial direction 242, such that the second portion 107D-2 is farther from the top surface 103T than the first portion 107D-1, and such that the third portion 107D-3 is farther from the top surface 103T than the second portion 107D-2. Also, the RF power delivery electrode 107D has a uniform configuration in the azimuthal direction 241 about the reference line 201 extending perpendicularly through the center location 202 of the top surface 103T of the ceramic structure 103C.

[0069] It should be understood that the three portions of the 107D-1 through 107D-3 are shown by way of example. In some embodiments, the RF power delivery electrode 107D includes just two steps 107D-1 and 107D-2. In these embodiments, the first portion 107D-1 of the RF power delivery electrode 107D is positioned at the radial center location 202 of the ceramic structure 103C, and that the second portion 107D-2 of the RF power delivery electrode 107D is configured and positioned to circumscribe the first portion 107D-1.

[0070] The electrostatic chuck 103 of Figure 5 A includes the baseplate 207 positioned within the ceramic structure 103C at a location between the RF power delivery electrode 107D and the bottom surface 103B of the ceramic structure 103C. The electrostatic chuck 103 includes anumber of electrically conductive structures 507-1 through 507-x6 (where x6 is an integer value greater than zero) extending between the baseplate 207 and the RF power delivery electrode 107D at a number of locations within a peripheral region of the ceramic structure 103C. The example embodiment of Figures 5A-5B shows eight electrically conductive structures 507-1 through 507-8. However, it should be understood that in various embodiments, the number x6 of electrically conductive structures 507-1 through 507-x6 can be either less than or greater than eight. The locations of the electrically conductive structures 507-1 through 507-x6 are azimuthally spaced apart in the azimuthal direction 241 about the reference line 201 extending perpendicularly through the center location 202 of the top surface 103T of the ceramic structure 103C. In some embodiments, the electrically conductive structures 507-1 through 507-x6 are substantially equally spaced apart in the azimuthal direction 241.

[0071] The RF power supply structure 109 extends from the baseplate 207 to a location outside of the ceramic structure 103C, with the RF power supply structure 109 connected to the RF power generator(s) 111 by way of the impedance matching system(s) 113. In this manner, RF power is supplied to the RF power delivery electrode 107D through the baseplate 207 and the electrically conductive structures 507-1 through 507-x6. In some alternative embodiments, the baseplate 207 is not present in the ceramic structure 103C, and the electrically conductive structures 507-1 through 507-x6 are configured / extended to be exposed for electrical connection at the outer surface, e.g., bottom, of the ceramic structure 103C. In these alternative embodiments, each of the electrically conductive structures 507-1 through 507-x6 is electrically connected to the RF power supply structure 109 outside of the ceramic structure 103C, such that each of the electrically conductive structures 507-1 through 507-x6 is electrically connected to the RF power generator(s) 111 by way of the impedance matching system(s) 113. In these alternative embodiments, RF power is supplied to the RF power delivery electrode 107D through the electrically conductive structures 507-1 through 507-x6 without being transmitted through the baseplate 207.

[0072] The sizes of the first distance 501, the second distance 503, and the third distance 505, and the corresponding shape of the RF power delivery electrode 107D and proximity of the RF power delivery electrode 107D to the top surface 103T of the ceramic structure 103C, are set to achieve a particular plasma 123 response, e.g., ion energy distribution and / or discharge density profile, when RF power is supplied to the RF power delivery electrode 107D during a plasmabased etching process, where the particular plasma 123 response provides for improved etch rate uniformity across the semiconductor wafer 105. More specifically, the sheath voltage on the semiconductor wafer 105 overlying portions of the RF power delivery electrode 107D that arecloser to the top surface 103T of the ceramic structure 103C will be greater than the sheath voltage on the semiconductor wafer 105 overlying portions of the RF power delivery electrode 107D that are farther from the top surface 103T of the electrostatic chuck. Therefore, a closer position of the RF power delivery electrode 107D to the top surface 103T of the ceramic structure 103C corresponds to a higher etch rate, and vice-versa.

[0073] Figure 6A shows a vertical cross-section view of the electrostatic chuck 103 with an upwardly stepped RF power delivery electrode 107E embedded within the electrostatic chuck 103, in accordance with some embodiments. Figure 6B shows a top view of the RF power delivery electrode 107E, in accordance with some embodiments. The electrostatic chuck 103 includes the ceramic structure 103C that has the top surface 103T, the bottom surface 103B, and the side surface 103S extending between the top surface 103T and the bottom surface 103B, as described above with regard to Figure 2A. It should be understood that the electrostatic chuck 103 includes other components that are not explicitly shown in the example of Figure 6 A in order to avoid obscuring description of the embodiments herein.

[0074] The RF power delivery electrode 107E is embedded within the ceramic structure 103C. More specifically, the ceramic structure 103C includes an upper portion 650 present between the RF power delivery electrode 107E and the top surface 103T of the ceramic structure 103C. The ceramic structure 103C also includes a lower portion 651 present between the RF power delivery electrode 107E and the bottom surface 103B of the ceramic structure 103C. In various embodiments, the upper portion 650 of the ceramic structure 103C includes one or more components and / or devices applicable to operation of the electrostatic chuck 103, such as the one or more clamping electrode(s) 125, the one or more bias voltage electrode(s) 141, cooling gas supply channels, and / or other components / devices. Similarly, in various embodiments, the lower portion 651 of the ceramic structure 103C includes one or more components and / or devices applicable to operation of the electrostatic chuck 103, such as one or more RF conveyance structures, one or more cooling gas supply channels, and / or other components / devices .

[0075] The RF power delivery electrode 107E includes a plurality of portions 107E-1 through 107E-x7 (where x7 is an integer greater than one) positioned at respective and different vertical distances away from the top surface 103T of the ceramic structure 103C. The example RF power delivery electrode 107ED includes three portions 107E-1 through 107E-3. The first portion 107E-1 is positioned a first distance 601 away from the top surface 103T of the ceramic structure 103C. The second portion 107E-2 is positioned a second distance 603 away from the top surface 103T of the ceramic structure 103C. The third portion 107E-3 is positioned a third distance 605away from the top surface 103T of the ceramic structure 103C. The second distance 603 is different than the first distance 601. The third distance 605 is different than each of the first distance 601 and the second distance 603. The RF power delivery electrode 107E is configured to step toward the top surface 103T of the ceramic structure 103C in the radial direction 242, such that the second portion 107E-2 is closer to the top surface 103T than the first portion 107E- 1, and such that the third portion 107E-3 is closer to the top surface 103T than the second portion 107E-2. Also, the RF power delivery electrode 107E has a uniform configuration in the azimuthal direction 241 about the reference line 201 extending perpendicularly through the center location 202 of the top surface 103T of the ceramic structure 103C.

[0076] It should be understood that the three portions of the 107E-1 through 107E-3 are shown by way of example. In some embodiments, the RF power delivery electrode 107E includes just two steps 107E-1 and 107E-2. In these embodiments, the first portion 107E-1 of the RF power delivery electrode 107E is positioned at the radial center location 202 of the ceramic structure 103C, and that the second portion 107E-2 of the RF power delivery electrode 107D is configured and positioned to circumscribe the first portion 107E-1.

[0077] The electrostatic chuck 103 of Figure 6A includes the baseplate 207 positioned within the ceramic structure 103C at a location between the RF power delivery electrode 107E and the bottom surface 103B of the ceramic structure 103C. The electrostatic chuck 103 includes a number of electrically conductive structures 607-1 through 607-x8 (where x8 is an integer value greater than zero) extending between the baseplate 207 and the RF power delivery electrode 107E at a number of locations within a peripheral region of the ceramic structure 103C. The example embodiment of Figures 6A-6B shows eight electrically conductive structures 607-1 through 607-8. However, it should be understood that in various embodiments, the number x8 of electrically conductive structures 607-1 through 607-x8 can be either less than or greater than eight. The locations of the electrically conductive structures 607-1 through 607-x8 are azimuthally spaced apart in the azimuthal direction 241 about the reference line 201 extending perpendicularly through the center location 202 of the top surface 103T of the ceramic structure 103C. In some embodiments, the electrically conductive structures 607-1 through 607-x8 are substantially equally spaced apart in the azimuthal direction 241.

[0078] The RF power supply structure 109 extends from the baseplate 207 to a location outside of the ceramic structure 103C, with the RF power supply structure 109 connected to the RF power generator(s) 111 by way of the impedance matching system(s) 113. In this manner, RF power is supplied to the RF power delivery electrode 107E through the baseplate 207 and the electrically conductive structures 607-1 through 607-x8. In some alternative embodiments, thebaseplate 207 is not present in the ceramic structure 103C, and the electrically conductive structures 607-1 through 607-x8 are configured / extended to be exposed for electrical connection at the outer surface, e.g., bottom, of the ceramic structure 103C. In these alternative embodiments, each of the electrically conductive structures 607-1 through 607-x8 is electrically connected to the RF power supply structure 109 outside of the ceramic structure 103C, such that each of the electrically conductive structures 607-1 through 607-x8 is electrically connected to the RF power generator(s) 111 by way of the impedance matching system(s) 113. In these alternative embodiments, RF power is supplied to the RF power delivery electrode 107E through the electrically conductive structures 607-1 through 607-x8 without being transmitted through the baseplate 207.

[0079] The sizes of the first distance 601, the second distance 603, and the third distance 605, and the corresponding shape of the RF power delivery electrode 107E and proximity of the RF power delivery electrode 107E to the top surface 103T of the ceramic structure 103C, are set to achieve a particular plasma 123 response, e.g., ion energy distribution and / or discharge density profile, when RF power is supplied to the RF power delivery electrode 107E during a plasmabased etching process, where the particular plasma 123 response provides for improved etch rate uniformity across the semiconductor wafer 105. More specifically, the sheath voltage on the semiconductor wafer 105 overlying portions of the RF power delivery electrode 107E that are closer to the top surface 103T of the ceramic structure 103C will be greater than the sheath voltage on the semiconductor wafer 105 overlying portions of the RF power delivery electrode 107E that are farther from the top surface 103T of the electrostatic chuck. Therefore, a closer position of the RF power delivery electrode 107E to the top surface 103T of the ceramic structure 103C corresponds to a higher etch rate, and vice-versa.

[0080] Figure 7A shows a vertical cross-section view of the electrostatic chuck 103 with a plurality of RF power delivery electrodes 107F-1, 107F-2, 107F-3 embedded within the electrostatic chuck 103, in accordance with some embodiments. Figure 7B shows a top view of the plurality of RF power delivery electrodes 107F-1, 107F-2, 107F-3, in accordance with some embodiments. The electrostatic chuck 103 includes the ceramic structure 103C that has the top surface 103T, the bottom surface 103B, and the side surface 103S extending between the top surface 103T and the bottom surface 103B, as described above with regard to Figure 2A. It should be understood that the electrostatic chuck 103 includes other components that are not explicitly shown in the example of Figure 7A in order to avoid obscuring description of the embodiments herein.

[0081] The plurality of RF power delivery electrodes 107F-1, 107F-2, 107F-3 are embeddedwithin the ceramic structure 103C. More specifically, the ceramic structure 103C includes an upper portion 750 present between the plurality of RF power delivery electrodes 107F-1, 107F- 2, 107F-3 and the top surface 103T of the ceramic structure 103C. The ceramic structure 103C also includes a lower portion 751 present between the plurality of RF power delivery electrodes 107F-1, 107F-2, 107F-3 and the bottom surface 103B of the ceramic structure 103C. In various embodiments, the upper portion 750 of the ceramic structure 103C includes one or more components and / or devices applicable to operation of the electrostatic chuck 103, such as the one or more clamping electrode(s) 125, the one or more bias voltage electrode(s) 141, cooling gas supply channels, and / or other components / devices. Similarly, in various embodiments, the lower portion 751 of the ceramic structure 103C includes one or more components and / or devices applicable to operation of the electrostatic chuck 103, such as one or more RF conveyance structures, one or more cooling gas supply channels, and / or other components / devices .

[0082] While the example embodiment of Figures 7A-7B includes the three RF power delivery electrodes 107F-1, 107F-2, 107F-3, it should be understood that various other embodiments can include two or more RF power delivery electrodes 107F-1 through 107F-y, where y is an integer greater than one, with the centermost one of the plurality of RF power delivery electrodes 107F- 1 through 107F-y positioned closest to the top surface 103T of the ceramic structure 103C, and with the others of the plurality of RF power delivery electrodes 107F-1 through 107F-y stepping away from the top surface 103T of the ceramic structure 103C as a function of radial distance away from the center reference line 201 of the ceramic structure 103C. The plurality of RF power delivery electrodes 107F-1 through 107F-y are physically separated from each other within the ceramic structure 103C. Also, each of the plurality of RF power delivery electrodes 107F-1 through 107F-y has a uniform configuration in the azimuthal direction 241 about the reference line 201 that extends perpendicularly through the center location 202 of the top surface 103T of the ceramic structure 103C.

[0083] The first RF power delivery electrode 107F-1 is positioned a first distance 701 away from the top surface 103T of the ceramic structure 103C. The second RF power delivery electrode 107F-2 is positioned a second distance 703 away from the top surface 103T of the ceramic structure 103C. The third RF power delivery electrode 107F-3 is positioned a third distance 705 away from the top surface 103T of the ceramic structure 103C. The second distance 703 is different than the first distance 701. The third distance 705 is different than each of the first distance 701 and the second distance 705. In the embodiment of Figure 7 A, the second distance 703 is greater than the first distance 701, and the third distance 705 is greater than the1 second distance 703. In this manner, the RF power delivery electrodes 107F-1, 107F-2, 107F-3 are configured to step away from the top surface 103T of the ceramic structure 103C in the radial direction 242 extending from the radial center location 202 of the ceramic structure 103C toward a radial peripheral location of the ceramic structure 103C.

[0084] The electrostatic chuck 103 of Figure 7A includes the baseplate 207 positioned within the ceramic structure 103C at a location between the plurality of RF power delivery electrodes 107F-1 through 107F-y and the bottom surface 103B of the ceramic structure 103C. At least one electrically conductive structure 707 extends between the baseplate 207 and the center- positioned RF power delivery electrode 107F-1. The electrostatic chuck 103 includes a number of electrically conductive structures 709-1 through 709-x9 (where x9 is an integer value greater than zero) extending between the baseplate 207 and the RF power delivery electrode 107F-2. The example embodiment of Figures 7A-7B shows four electrically conductive structures 709- 1 through 709-4, i.e., x9=4. The electrically conductive structures 709-1 through 709-x9 are azimuthally spaced apart in the azimuthal direction 241 about the reference line 201 that extends perpendicularly through the center location 202 of the top surface 103T of the ceramic structure 103C. The electrostatic chuck 103 includes a number of electrically conductive structures 711- 1 through 711-xlO (where xlO is an integer value greater than zero) extending between the baseplate 207 and the RF power delivery electrode 107F-3. The example embodiment of Figures 7A-7B shows eight electrically conductive structures 711-1 through 711-8, i.e., xl0=8. The electrically conductive structures 711-1 through 711-xlO are azimuthally spaced apart in the azimuthal direction 241 about the reference line 201. It should be understood that in various embodiments each of the plurality of RF power delivery electrodes 107F-1 through 107F-y is electrically connected to the baseplate 207 by one or more electrically conductive structures.

[0085] The RF power supply structure 109 extends from the baseplate 207 to a location outside of the ceramic structure 103C, with the RF power supply structure 109 connected to the RF power generator(s) 111 by way of the impedance matching system(s) 113. In this manner, RF power is supplied to each of the RF power delivery electrodes 107F-1 through 107F-y through the baseplate 207 and the corresponding electrically conductive structures, e.g., 707, 709-1 through 709-x9, 711-1 through 711-xlO. In some alternative embodiments, the baseplate 207 is not present in the ceramic structure 103C, and the electrically conductive structures 707, 709-1 through 709-x9, and 711-1 through 711-xlO are configured / extended to be exposed for electrical connection at the outer surface, e.g., bottom, of the ceramic structure 103C. In these alternative embodiments, each of the electrically conductive structures 707, 709-1 through 709-x9, and 711- 1 through 711-xlO is electrically connected to the RF power supply structure 109 outside of theceramic structure 103C, such that each of the electrically conductive structures 707, 709-1 through 709-x9, and 711-1 through 711-xlO is electrically connected to the RF power generator(s) 111 by way of the impedance matching system(s) 113. In these alternative embodiments, RF power is supplied to the RF power delivery electrodes 107F-1 through 107F- y through the corresponding electrically conductive structures 707, 709-1 through 709-x9, and 711-1 through 711-xlO without being transmitted through the baseplate 207.

[0086] The sizes of the various distances, e.g., 701, 703, 705, between the RF power delivery electrodes 107F-1 through 107F-y and the top surface 103T of the ceramic structure 103C, and the corresponding shapes (radial sizes) of the RF power delivery electrodes 107F-1 through 107F-y, are set to achieve a particular plasma 123 response, e.g., ion energy distribution and / or discharge density profile, when RF power is supplied to the RF power delivery electrodes 107F- 1 through 107F-y during a plasma-based etching process, where the particular plasma 123 response provides for improved etch rate uniformity across the semiconductor wafer 105. More specifically, the sheath voltage on the semiconductor wafer 105 overlying ones of the plurality of RF power delivery electrodes 107F-1 through 107F-y that are closer to the top surface 103T of the ceramic structure 103C will be greater than the sheath voltage on the semiconductor wafer 105 overlying ones of the plurality of RF power delivery electrodes 107F-1 through 107F-y that are farther from the top surface 103T of the electrostatic chuck. Therefore, a closer position of a given one of the plurality of RF power delivery electrodes 107F-1 through 107F-y to the top surface 103T of the ceramic structure 103C corresponds to a higher etch rate, and vice-versa.

[0087] Figure 8A shows a vertical cross-section view of the electrostatic chuck 103 with a plurality of RF power delivery electrodes 107G-1, 107G-2, 107G-3 embedded within the electrostatic chuck 103, in accordance with some embodiments. Figure 8B shows a top view of the plurality of RF power delivery electrodes 107G-1, 107G-2, 107G-3, in accordance with some embodiments. The electrostatic chuck 103 includes the ceramic structure 103C that has the top surface 103T, the bottom surface 103B, and the side surface 103S extending between the top surface 103T and the bottom surface 103B, as described above with regard to Figure 2A. It should be understood that the electrostatic chuck 103 includes other components that are not explicitly shown in the example of Figure 8A in order to avoid obscuring description of the embodiments herein.

[0088] The plurality of RF power delivery electrodes 107G-1, 107G-2, 107G-3 are embedded within the ceramic structure 103C. More specifically, the ceramic structure 103C includes an upper portion 850 present between the plurality of RF power delivery electrodes 107G-1, 107G- 2, 107G-3 and the top surface 103T of the ceramic structure 103C. The ceramic structure 103Calso includes a lower portion 851 present between the plurality of RF power delivery electrodes 107G-1, 107G-2, 107G-3 and the bottom surface 103B of the ceramic structure 103C. In various embodiments, the upper portion 850 of the ceramic structure 103C includes one or more components and / or devices applicable to operation of the electrostatic chuck 103, such as the one or more clamping electrode(s) 125, the one or more bias voltage electrode(s) 141, cooling gas supply channels, and / or other components / devices. Similarly, in various embodiments, the lower portion 851 of the ceramic structure 103C includes one or more components and / or devices applicable to operation of the electrostatic chuck 103, such as one or more RF conveyance structures, one or more cooling gas supply channels, and / or other components / devices .

[0089] While the example embodiment of Figures 8A-8B includes the three RF power delivery electrodes 107G-1, 107G-2, 107G-3, it should be understood that various other embodiments can include two or more RF power delivery electrodes 107G-1 through 107G-Z, where z is an integer greater than one, with the centermost one of the plurality of RF power delivery electrodes 107G-1 through 107G-Z positioned farthest from the top surface 103T of the ceramic structure 103C, and with the others of the plurality of RF power delivery electrodes 107G-1 through 107G- z stepping toward the top surface 103T of the ceramic structure 103C as a function of radial distance away from the center reference line 201 of the ceramic structure 103C. The plurality of RF power delivery electrodes 107G-1 through 107G-Z are physically separated from each other within the ceramic structure 103C. Also, each of the plurality of RF power delivery electrodes 107G-1 through 107G-Z has a uniform configuration in the azimuthal direction 241 about the reference line 201 that extends perpendicularly through the center location 202 of the top surface 103T of the ceramic structure 103C.

[0090] The first RF power delivery electrode 107G-1 is positioned a first distance 801 away from the top surface 103T of the ceramic structure 103C. The second RF power delivery electrode 107G-2 is positioned a second distance 803 away from the top surface 103T of the ceramic structure 103C. The third RF power delivery electrode 107G-3 is positioned a third distance 805 away from the top surface 103T of the ceramic structure 103C. The second distance 803 is different than the first distance 801. The third distance 805 is different than each of the first distance 801 and the second distance 805. In the embodiment of Figure 8 A, the second distance 803 is less than the first distance 801, and the third distance 805 is less than the second distance 803. In this manner, the RF power delivery electrodes 107G-1, 107G-2, 107G-3 are configured to step away from the top surface 103T of the ceramic structure 103C in the radial direction 242 extending from the radial center location 202 of the ceramic structure 103C towarda radial peripheral location of the ceramic structure 103C.

[0091] The electrostatic chuck 103 of Figure 8 A includes the baseplate 207 positioned within the ceramic structure 103C at a location between the plurality of RF power delivery electrodes 107G-1 through 107G-Z and the bottom surface 103B of the ceramic structure 103C. At least one electrically conductive structure 807 extends between the baseplate 207 and the center- positioned RF power delivery electrode 107G-1. The electrostatic chuck 103 includes a number of electrically conductive structures 809-1 through 809-xl l (where xl l is an integer value greater than zero) extending between the baseplate 207 and the RF power delivery electrode 107G-2. The example embodiment of Figures 8A-8B shows four electrically conductive structures 809-1 through 809-4, i.e., xl l=4. The electrically conductive structures 809-1 through 809-xl l are azimuthally spaced apart in the azimuthal direction 241 about the reference line 201 that extends perpendicularly through the center location 202 of the top surface 103T of the ceramic structure 103C. The electrostatic chuck 103 includes a number of electrically conductive structures 811-1 through 811-xl2 (where xl2 is an integer value greater than zero) extending between the baseplate 207 and the RF power delivery electrode 107G-3. The example embodiment of Figures 8A-8B shows eight electrically conductive structures 811-1 through 811- 8, i.e., xl2=8. The electrically conductive structures 811-1 through 811-xl2 are azimuthally spaced apart in the azimuthal direction 241 about the reference line 201. It should be understood that in various embodiments each of the plurality of RF power delivery electrodes 107G-1 through 107G-Z is electrically connected to the baseplate 207 by one or more electrically conductive structures.

[0092] The RF power supply structure 109 extends from the baseplate 207 to a location outside of the ceramic structure 103C, with the RF power supply structure 109 connected to the RF power generator(s) 111 by way of the impedance matching system(s) 113. In this manner, RF power is supplied to each of the RF power delivery electrodes 107G-1 through 107G-Z through the baseplate 207 and the corresponding electrically conductive structures, e.g., 807, 809-1 through 809-xl l, 811-1 through 811-xl2. In some alternative embodiments, the baseplate 207 is not present in the ceramic structure 103C, and the electrically conductive structures 807, 809- 1 through 809-xl l, and 811-1 through 811-xl2 are configured / extended to be exposed for electrical connection at the outer surface, e.g., bottom, of the ceramic structure 103C. In these alternative embodiments, each of the electrically conductive structures 807, 809-1 through 809- xl l, and 811-1 through 811-xl2 is electrically connected to the RF power supply structure 109 outside of the ceramic structure 103C, such that each of the electrically conductive structures 807, 809-1 through 809-xl l, and 811-1 through 811-xl2 is electrically connected to the RFpower generator(s) 111 by way of the impedance matching system(s) 113. In these alternative embodiments, RF power is supplied to the RF power delivery electrodes 107G-1 through 107G- z through the corresponding electrically conductive structures 807, 809-1 through 809-xl l, and 811-1 through 81 l-xl2 without being transmitted through the baseplate 207.

[0093] The sizes of the various distances, e.g., 801, 803, 805, between the RF power delivery electrodes 107G-1 through 107G-Z and the top surface 103T of the ceramic structure 103C, and the corresponding shapes (radial sizes) of the RF power delivery electrodes 107G-1 through 107G-Z, are set to achieve a particular plasma 123 response, e.g., ion energy distribution and / or discharge density profile, when RF power is supplied to the RF power delivery electrodes 107G- 1 through 107G-Z during a plasma-based etching process, where the particular plasma 123 response provides for improved etch rate uniformity across the semiconductor wafer 105. More specifically, the sheath voltage on the semiconductor wafer 105 overlying ones of the plurality of RF power delivery electrodes 107G-1 through 107G-Z that are closer to the top surface 103T of the ceramic structure 103C will be greater than the sheath voltage on the semiconductor wafer 105 overlying ones of the plurality of RF power delivery electrodes 107G-1 through 107G-Z that are farther from the top surface 103T of the electrostatic chuck. Therefore, a closer position of a given one of the plurality of RF power delivery electrodes 107G-1 through 107G-Z to the top surface 103T of the ceramic structure 103C corresponds to a higher etch rate, and vice-versa.

[0094] Figure 9A shows a vertical cross-section view of the electrostatic chuck 103 with a plurality of RF power delivery electrodes 107H-1, 107H-2, 107H-3 embedded within the electrostatic chuck 103, in accordance with some embodiments. Figure 9B shows a top view of the plurality of RF power delivery electrodes 107H-1, 107H-2, 107H-3, in accordance with some embodiments. The electrostatic chuck 103 includes the ceramic structure 103C that has the top surface 103T, the bottom surface 103B, and the side surface 103S extending between the top surface 103T and the bottom surface 103B, as described above with regard to Figure 2A. It should be understood that the electrostatic chuck 103 includes other components that are not explicitly shown in the example of Figure 9A in order to avoid obscuring description of the embodiments herein.

[0095] The plurality of RF power delivery electrodes 107H-1, 107H-2, 107H-3 are embedded within the ceramic structure 103C. More specifically, the ceramic structure 103C includes an upper portion 950 present between the plurality of RF power delivery electrodes 107H-1, 107H- 2, 107H-3 and the top surface 103T of the ceramic structure 103C. The ceramic structure 103C also includes a lower portion 951 present between the plurality of RF power delivery electrodes 107H-1, 107H-2, 107H-3 and the bottom surface 103B of the ceramic structure 103C. In variousembodiments, the upper portion 950 of the ceramic structure 103C includes one or more components and / or devices applicable to operation of the electrostatic chuck 103, such as the one or more clamping electrode(s) 125, the one or more bias voltage electrode(s) 141, cooling gas supply channels, and / or other components / devices. Similarly, in various embodiments, the lower portion 951 of the ceramic structure 103C includes one or more components and / or devices applicable to operation of the electrostatic chuck 103, such as one or more RF conveyance structures, one or more cooling gas supply channels, and / or other components / devices .

[0096] While the example embodiment of Figures 9A-9B includes the three RF power delivery electrodes 107H-1, 107H-2, 107H-3, it should be understood that various other embodiments can include two or more RF power delivery electrodes 107H-1 through 107H-W, where w is an integer greater than one. The plurality of RF power delivery electrodes 107H-1 through 107H- w are physically separated from each other within the ceramic structure 103C. Also, each of the plurality of RF power delivery electrodes 107H-1 through 107H-W has a uniform configuration in the azimuthal direction 241 about the reference line 201 that extends perpendicularly through the center location 202 of the top surface 103T of the ceramic structure 103C.

[0097] The first RF power delivery electrode 107H-1 is positioned a first distance 901 away from the top surface 103T of the ceramic structure 103C. The second RF power delivery electrode 107H-2 is positioned a second distance 903 away from the top surface 103T of the ceramic structure 103C. The third RF power delivery electrode 107H-3 is positioned a third distance 905 away from the top surface 103T of the ceramic structure 103C. The first distance 901, the second distance 903, and the third distance 905 are substantially equal to each other. In this manner, the plurality of RF power delivery electrodes 107H-1, 107H-2, 107H-3 are configured and oriented in a substantially coplanar manner with respect to each other within the ceramic structure 103C.

[0098] The electrostatic chuck 103 of Figure 9A includes the baseplate 207 positioned within the ceramic structure 103C at a location between the plurality of RF power delivery electrodes 107H-1 through 107H-W and the bottom surface 103B of the ceramic structure 103C. At least one electrically conductive structure 907 extends between the baseplate 207 and the center- positioned RF power delivery electrode 107H-1. The electrostatic chuck 103 includes a number of electrically conductive structures 909-1 through 909-xl3 (where xl3 is an integer value greater than zero) extending between the baseplate 207 and the RF power delivery electrode 107H-2. The example embodiment of Figures 9A-9B shows four electrically conductive structures 909-1 through 909-4, i.e., xl3=4. The electrically conductive structures 909-1 through909-xl3 are azimuthally spaced apart in the azimuthal direction 241 about the reference line 201 that extends perpendicularly through the center location 202 of the top surface 103T of the ceramic structure 103C. The electrostatic chuck 103 includes a number of electrically conductive structures 911-1 through 911-xl4 (where xl4 is an integer value greater than zero) extending between the baseplate 207 and the RF power delivery electrode 107H-3. The example embodiment of Figures 9A-9B shows eight electrically conductive structures 911-1 through 911- 8, i.e., xl4=8. The electrically conductive structures 911-1 through 911-xl4 are azimuthally spaced apart in the azimuthal direction 241 about the reference line 201. It should be understood that in various embodiments each of the plurality of RF power delivery electrodes 107H-1 through 107H-W is electrically connected to the baseplate 207 by one or more electrically conductive structures.

[0099] The RF power supply structure 109 extends from the baseplate 207 to a location outside of the ceramic structure 103C, with the RF power supply structure 109 connected to the RF power generator(s) 111 by way of the impedance matching system(s) 113. In this manner, RF power is supplied to each of the RF power delivery electrodes 107H-1 through 107H-W through the baseplate 207 and the corresponding electrically conductive structures, e.g., 907, 909-1 through 909-xl3, 911-1 through 911-xl4. In some alternative embodiments, the baseplate 207 is not present in the ceramic structure 103C, and the electrically conductive structures 907, 909- 1 through 909-xl3, and 911-1 through 911-xl4 are configured / extended to be exposed for electrical connection at the outer surface, e.g., bottom, of the ceramic structure 103C. In these alternative embodiments, each of the electrically conductive structures 907, 909-1 through 909- xl3, and 911-1 through 911-xl4 is electrically connected to the RF power supply structure 109 outside of the ceramic structure 103C, such that each of the electrically conductive structures 907, 909-1 through 909-xl3, and 911-1 through 911-xl4 is electrically connected to the RF power generator(s) 111 by way of the impedance matching system(s) 113. In these alternative embodiments, RF power is supplied to the RF power delivery electrodes 107H-1 through 107H- w through the corresponding electrically conductive structures 907, 909-1 through 909-xl3, and 911-1 through 91 l-xl4 without being transmitted through the baseplate 207.

[0100] The substantially equal size of the various distances, e.g., 901, 903, 905, between the RF power delivery electrodes 107H-1 through 107H-W and the top surface 103T of the ceramic structure 103C, and the corresponding shapes (radial sizes) of the RF power delivery electrodes 107H-1 through 107H-W, are set to achieve a particular plasma 123 response, e.g., ion energy distribution and / or discharge density profile, when RF power is supplied to the RF power delivery electrodes 107H-1 through 107H-W during a plasma-based etching process, where theparticular plasma 123 response provides for improved etch rate uniformity across the semiconductor wafer 105. More specifically, the sheath voltage on the semiconductor wafer 105 overlying ones of the plurality of RF power delivery electrodes 107H-1 through 107H-W that are closer to the top surface 103T of the ceramic structure 103C will be greater than the sheath voltage on the semiconductor wafer 105 overlying ones of the plurality of RF power delivery electrodes 107H-1 through 107H-W that are farther from the top surface 103T of the electrostatic chuck. Therefore, a closer position of a given one of the plurality of RF power delivery electrodes 107H-1 through 107H-W to the top surface 103T of the ceramic structure 103C corresponds to a higher etch rate, and vice-versa.

[0101] Figure 10A shows a vertical cross-section view of the electrostatic chuck 103 with a plurality of RF power delivery electrodes 1071-1, 1071-2, 1071-3 embedded within the electrostatic chuck 103 and respectively electrically connected to receive separately controlled RF powers, in accordance with some embodiments. Figure 10B shows a top view of the plurality of RF power delivery electrodes 1071-1, 1071-2, 1071-3, in accordance with some embodiments. The electrostatic chuck 103 includes the ceramic structure 103C that has the top surface 103T, the bottom surface 103B, and the side surface 103S extending between the top surface 103T and the bottom surface 103B, as described above with regard to Figure 2A. It should be understood that the electrostatic chuck 103 includes other components that are not explicitly shown in the example of Figure 10A in order to avoid obscuring description of the embodiments herein.

[0102] The plurality of RF power delivery electrodes 1071-1, 1071-2, 1071-3 are embedded within the ceramic structure 103C. More specifically, the ceramic structure 103C includes an upper portion 1050 present between the plurality of RF power delivery electrodes 1071-1, 1071- 2, 1071-3 and the top surface 103T of the ceramic structure 103C. The ceramic structure 103C also includes a lower portion 1051 present between the plurality of RF power delivery electrodes 1071-1, 1071-2, 1071-3 and the bottom surface 103B of the ceramic structure 103C. In various embodiments, the upper portion 1050 of the ceramic structure 103C includes one or more components and / or devices applicable to operation of the electrostatic chuck 103, such as the one or more clamping electrode(s) 125, the one or more bias voltage electrode(s) 141, cooling gas supply channels, and / or other components / devices. Similarly, in various embodiments, the lower portion 1051 of the ceramic structure 103C includes one or more components and / or devices applicable to operation of the electrostatic chuck 103, such as one or more RF conveyance structures, one or more cooling gas supply channels, and / or other components / devices .

[0103] While the example embodiment of Figures 10A-10B includes the three RF powerdelivery electrodes 1071-1, 1071-2, 1071-3, it should be understood that various other embodiments can include two or more RF power delivery electrodes 1071-1 through 1071-u, where u is an integer greater than one, with the centermost one of the plurality of RF power delivery electrodes 1071-1 through 1071-u positioned closest to the top surface 103T of the ceramic structure 103C, and with the others of the plurality of RF power delivery electrodes 1071-1 through 1071-u stepping away from the top surface 103T of the ceramic structure 103C as a function of radial distance away from the center reference line 201 of the ceramic structure 103C. The plurality of RF power delivery electrodes 1071-1 through 1071-u are physically separated from each other within the ceramic structure 103C. Also, each of the plurality of RF power delivery electrodes 1071-1 through 1071-u has a uniform configuration in the azimuthal direction 241 about the reference line 201 that extends perpendicularly through the center location 202 of the top surface 103T of the ceramic structure 103C.

[0104] The first RF power delivery electrode 1071-1 is positioned a first distance 1001 away from the top surface 103T of the ceramic structure 103C. The second RF power delivery electrode 1071-2 is positioned a second distance 1003 away from the top surface 103T of the ceramic structure 103C. The third RF power delivery electrode 1071-3 is positioned a third distance 1005 away from the top surface 103T of the ceramic structure 103C. The second distance 1003 is different than the first distance 1001. The third distance 1005 is different than each of the first distance 1001 and the second distance 1005. In the embodiment of Figure 10 A, the second distance 1003 is greater than the first distance 1001, and the third distance 1005 is greater than the second distance 1003. In this manner, the RF power delivery electrodes 1071-1, 1071-2, 1071-3 are configured to step away from the top surface 103T of the ceramic structure 103C in the radial direction 242 extending from the radial center location 202 of the ceramic structure 103C toward a radial peripheral location of the ceramic structure 103C.

[0105] At least one electrically conductive structure 1007 extends from the first RF power delivery electrode 1071-1 to a location outside of the electrostatic chuck 103. A number of electrically conductive structures 1009-1 through 1009-xl5 (where xl5 is an integer value greater than zero) extends from the second RF power delivery electrode 1071-2 to respective locations outside of the electrostatic chuck 103. The example embodiment of Figures 10A-10B shows four electrically conductive structures 1009-1 through 1009-4, i.e., xl5=4. The electrically conductive structures 1009-1 through 1009-xl5 are azimuthally spaced apart in the azimuthal direction 241 about the reference line 201 that extends perpendicularly through the center location 202 of the top surface 103T of the ceramic structure 103C. A number of electrically conductive structures 1011-1 through 1011-xl6 (where xl6 is an integer valuegreater than zero) extends from the third RF power delivery electrode 1071-3 to respective locations outside of the electrostatic chuck 103. The example embodiment of Figures 10A-10B shows eight electrically conductive structures 1011-1 through 1011-8, i.e., xl6=8. The electrically conductive structures 1011-1 through 1011-xl6 are azimuthally spaced apart in the azimuthal direction 241 about the reference line 201.

[0106] An RF power conveyance device 109A electrically connects the first RF power delivery electrode 1071-1 to the RF power generator(s) 111 by way of the matching system(s) 113 and the at least one electrically conductive structures 1007. An RF power conveyance device 109B electrically connects the second RF power delivery electrode 1071-2 to the RF power generator(s) 111 by way of the matching system(s) 113 and the electrically conductive structures 1009-1 through 1009-xl5. In some embodiments, the RF power conveyance device 109B is configured to include a plurality of conductors 109B-1 through 109B-xl5, respectively connected to the electrically conductive structures 1009-1 through 1009-xl5. The plurality of conductors 109B-1 through 109B-xl5 are electrically connected to an electrically conductive distribution ring 1021, which is electrically connected to the RF power generator(s) 111 by way of the matching system(s) 113. Also, an RF power conveyance device 109C electrically connects the third RF power delivery electrode 1071-3 to the RF power generator(s) 111 by way of the matching system(s) 113 and the electrically conductive structures 1011-1 through 1011-xl6. In some embodiments, the RF power conveyance device 109C is configured to include a plurality of conductors 109C-1 through 109C-xl6, respectively connected to the electrically conductive structures 1011-1 through 1011-xl6. The plurality of conductors 109C-1 through 109C-xl6 are electrically connected to an electrically conductive distribution ring 1023, which is electrically connected to the RF power generator(s) 111 by way of the matching system(s) 113.

[0107] Each of the plurality of RF power conveyance devices 109A, 109B, 109C is configured to separately and independently convey RF power to a corresponding one of the plurality of RF power delivery electrodes 1071-1, 1071-2, 1071-3. Each of the RF power conveyance devices 109 A, 109B, 109C includes at least one electrically conductive structure electrically connected to a corresponding one of the plurality of RF power delivery electrodes 1071-1, 1071-2, 1071-3. In some embodiments, an RF power splitter 1013 is implemented to distribute the RF power output by the RF generator(s) 111 to the RF power delivery electrodes 1071-1, 1071-2, 1071-3 through the RF power conveyance devices 109A, 109B, 109C, respectively.

[0108] In some embodiments, RF signals and / or electrical signals present on the RF power supply structure 109 and / or the RF power conveyance devices 109 A, 109B, 109C provide an indication of how much RF power is actually being transmitted to the plasma 123 load withinthe chamber 101. In some embodiments, a voltage-current sensor 2001 is implemented to measure electrical voltage and electrical current on the RF power supply structure 109. The product of the electrical voltage and electrical current measured on the RF power supply structure 109 indicates an amount of RF power transmitted through the RF power supply structure 109. In some embodiments, voltage-current (VI) sensors 2001 A, 200 IB, and 2001C are implemented to measure electrical voltage and electrical current on the RF power supply structures 109A, 109B, and 109C, respectively. The product of the electrical voltage and electrical current measured on the RF power supply structure 109A indicates an amount of RF power transmitted through the RF power supply structure 109A. The product of the electrical voltage and electrical current measured on the RF power supply structure 109B indicates an amount of RF power transmitted through the RF power supply structure 109B. The product of the electrical voltage and electrical current measured on the RF power supply structure 109C indicates an amount of RF power transmitted through the RF power supply structure 109C. In some embodiments, the electrical current linner transmitted through the RF power conveyance device 109A is measured by the VI sensor 2001A. Also, the electrical current Imiddie transmitted through the RF power conveyance device 109B is measured by the VI sensor 2001B. Also, the electrical current Iouter transmitted through the RF power conveyance device 109C is measured by the VI sensor 2001C. In some embodiments, the RF power splitter 1013 is configured to control a ratio of Imiddie / Iinner, so as to control a ratio of RF power delivered to the RF power delivery electrode 1071-2 relative to the RF power delivered to the RF power delivery electrode 1071-1. Also, the RF power splitter 1013 is configured to control a ratio of louter / Iinner, so as to control a ratio of RF power delivered to the RF power delivery electrode 1071-3 relative to the RF power delivered to the RF power delivery electrode 1071-1. In these embodiments, the electrical current linner is the reference electrical current for RF power delivery control, i.e., the denominator of the controlled ratios of electrical current. In some embodiments, one of the plurality of RF power delivery electrodes 1071-1 through 1071-u that spatially corresponds to the more stable overlying plasma 123 is used as the reference electrical current for RF power delivery control. In this manner, the embedded RF power delivery electrodes 1071-1, 1071-2, and 1071-3 provide a capability to control the ratio of RF power delivered to different radial zones of the electrostatic chuck 103.

[0109] In this manner, RF power is supplied to each of the RF power delivery electrodes 1071- 1, 1071-2, and 1071-3 through the corresponding RF power conveyance device 109A, 109B, 109C, respectively. The various distances 1001, 1003, and 1005, in combination with the corresponding shapes (radial sizes) of the RF power delivery electrodes 1071-1, 1071-2, and1071-3, in combination with the separately controlled RF power transmission through the different RF power conveyance devices 109 A, 109B, and 109C are collectively set to achieve a particular plasma 123 response, e.g., ion energy distribution and / or discharge density profile, when RF power is supplied to the RF power delivery electrodes 1071-1, 1071-2, and 1071-3 during a plasma-based etching process, where the particular plasma 123 response provides for improved etch rate uniformity across the semiconductor wafer 105.

[0110] Figure 11 shows a flowchart of a method for plasma processing of the semiconductor wafer 105, in accordance with some embodiments. The method includes an operation 1101 for positioning the semiconductor wafer 105 on a wafer support area of the electrostatic chuck 103. The electrostatic chuck 103 includes a ceramic structure 103C that has a top surface 103T, a bottom surface 103B, and a side surface 103S extending between the top surface 103T and the bottom surface 103B. The top surface 103T is configured to have the wafer support area. The electrostatic chuck 103 includes an RF power delivery electrode 107A, 107B, 107C, 107D, 107E (generally referred to as 107mono, hereafter) embedded within the ceramic structure 103C. The RF power delivery electrode 107mono is monolithic structure. The RF power delivery electrode 107mono includes a first portion positioned a first distance away from the top surface 103T of the ceramic structure 103C and a second portion positioned a second distance away from the top surface 103T of the ceramic structure 103C, where the second distance is different than the first distance. The method also includes an operation 1103 for supplying a process gas to the region 102 overlying the semiconductor wafer 105. The method also includes an operation 1105 for supplying an RF power to the RF power delivery electrode 107 mono. The RF power transforms the process gas into the plasma 123 within the region 102 overlying the semiconductor wafer 105. The first distance between the first portion of the RF power delivery electrode 107 mono and the top surface 103T of the ceramic structure 103C is sized to control one or more of a first voltage on a first portion of the semiconductor wafer 105 overlying the first portion of the RF power delivery electrode 107mono, a first density of the plasma 123 overlying the first portion of the semiconductor wafer 105, and a first ion flux incident upon the first portion of the semiconductor wafer 105, so as to minimize a difference between a first etch rate across the first portion of the semiconductor wafer 105 and an average etch rate across an entirety of the semiconductor wafer 105. Also, the second distance between the second portion of the RF power delivery electrode 107 mono and the top surface 103T of the ceramic structure 103C is sized to control one or more of a second voltage on a second portion of the semiconductor wafer 105 overlying the second portion of the RF power delivery electrode 107mono, a second density of the plasma 123 overlying the second portion of the semiconductor wafer 105, and a second ionflux incident upon the second portion of the semiconductor wafer 105, so as to minimize a difference between a second etch rate across the second portion of the semiconductor wafer 105 and the average etch rate across the entirety of the semiconductor wafer 105.

[0111] Figure 12 shows a flowchart of a method for plasma processing of the semiconductor wafer 105, in accordance with some embodiments. The method includes an operation 1201 for positioning the semiconductor wafer 105 on the wafer support area of the electrostatic chuck 103. The electrostatic chuck 103 includes the ceramic structure 103C that has the top surface 103T, the bottom surface 103B, and the side surface 103S extending between the top surface 103T and the bottom surface 103B. The wafer support area is on the top surface 103T of the electrostatic chuck 103. The electrostatic chuck 103 includes a plurality of RF power delivery electrodes 107F-1 through 107F-y, 107G-1 through 107G-Z, 107H-1 through 107H-W, 1071-1 through 1071-u (generally referred to as 107seg, hereafter) embedded within the ceramic structure 103C. The plurality of RF power delivery electrodes 107seg are physically separated (spaced apart) from each other within the ceramic structure 103C. The plurality of RF power delivery electrodes 107seg includes a first RF power delivery electrode 107segl positioned a first distance away from the top surface 103T of the ceramic structure 103C and a second RF power delivery electrode 107seg2 positioned a second distance away from the top surface 103T of the ceramic structure 103C, where the second distance is different than the first distance. The method also includes an operation 1203 for supplying a process gas to the region 102 overlying the semiconductor wafer 105. The method also includes an operation 1205 for supplying a first RF power to the first RF power delivery electrode 107segl. The method also includes an operation 1207 for supplying a second RF power to the second RF power delivery electrode 107seg2. The first RF power and the second RF power transform the process gas into the plasma 123 within the region 102 overlying the semiconductor wafer 105. The first distance between the first RF power delivery electrode 107segl and the top surface 103T of the ceramic structure 103C is sized to control one or more of a first voltage on a first portion of the semiconductor wafer 105 overlying the first RF power delivery electrode 107segl, a first density of the plasma 123 overlying the first portion of the semiconductor wafer 105, and a first ion flux incident upon the first portion of the semiconductor wafer 105, so as to minimize a difference between a first etch rate across the first portion of the semiconductor wafer 105 and an average etch rate across an entirety of the semiconductor wafer 105. The second distance between the second RF power delivery electrode 107seg2 and the top surface 103T of the ceramic structure 103C is sized to control one or more of a second voltage on a second portion of the semiconductor wafer 105 overlying the second RF power delivery electrode 107seg2, a second density of the plasma 123overlying the second portion of the semiconductor wafer 105, and a second ion flux incident upon the second portion of the semiconductor wafer 105, so as to minimize a difference between a second etch rate across the second portion of the semiconductor wafer 105 and the average etch rate across the entirety of the semiconductor wafer 105.

[0112] Various embodiments are disclosed herein for shaped RF power delivery electrodes 107mono, 107seg embedded within the electrostatic chuck 103 to provide for minimization of the radial non-uniformity in both plasma 123 discharge and plasma 123 ion energy distribution (IED). Also, in various embodiments, the RF power delivered to the different segments of the segmented RF power delivery electrodes 107 seg are separately controlled so as to control the radial plasma 123 discharge uniformity across the semiconductor wafer 105, which in turn controls the radial etch rate uniformity across the semiconductor wafer 105. Generally speaking, the objective is to have a substantially uniform plasma density over the entirety of the top surface of the semiconductor wafer 105. In line with this objective, the shaped RF power delivery electrodes 107mono, 107seg embedded within the electrostatic chuck 103 are configured to decrease the plasma 123 density in locations where the plasma 123 density is known to be higher than the average plasma 123 density, and / or increase the plasma 123 density in locations where the plasma 123 density is known to be lower than the average plasma 123 density.

[0113] Although the method operations were described in a specific order, it should be understood that other housekeeping operations may be performed in between operations, or operations may be adjusted so that they occur at slightly different times or may be distributed in a system which allows the occurrence of the processing operations at various intervals associated with the processing.

[0114] 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 can be practiced within the scope of the appended claims. Accordingly, the present embodiments are to be considered as illustrative and not restrictive, and the embodiments are not to be limited to the details given herein, but may be modified within the scope and equivalents of the appended claims.

[0115] It should be understood that the various embodiments defined herein may be combined or assembled into specific implementations using the various features disclosed herein. Thus, the examples provided are just some possible examples, without limitation to the various implementations that are possible by combining the various elements to define many more implementations. In some examples, some implementations may include fewer elements, without departing from the spirit of the disclosed or equivalent implementations.

[0116] What is claimed is:

Claims

Claims1. An electrostatic chuck, comprising: a ceramic structure having a top surface, a bottom surface, and a side surface extending between the top surface and the bottom surface, the top surface configured to support a semiconductor wafer during a plasma-based fabrication process; and a radiofrequency power delivery electrode embedded within the ceramic structure, the radiofrequency power delivery electrode including a first portion positioned a first distance away from the top surface of the ceramic structure and a second portion positioned a second distance away from the top surface of the ceramic structure, the second distance being different than the first distance.

2. The electrostatic chuck as recited in claim 1, wherein the ceramic structure includes an upper portion present between the radiofrequency power delivery electrode and the top surface of the ceramic structure, and wherein the ceramic structure includes a lower portion present between the radiofrequency power delivery electrode and the bottom surface of the ceramic structure.

3. The electrostatic chuck as recited in claim 1, wherein the radiofrequency power delivery electrode has a uniform configuration in an azimuthal direction about a reference line extending perpendicularly through a center location of the top surface of the ceramic structure.

4. The electrostatic chuck as recited in claim 3, wherein the radiofrequency power delivery electrode is configured to curve away from the top surface of the ceramic structure in a radial direction extending from the first portion of the radiofrequency power delivery electrode to the second portion of the radiofrequency power delivery electrode.

5. The electrostatic chuck as recited in claim 4, wherein the first portion of the radiofrequency power delivery electrode is positioned at a radial center location of the ceramic structure, and wherein the second portion of the radiofrequency power delivery electrode is positioned at a radial peripheral location of the ceramic structure.

6. The electrostatic chuck as recited in claim 4, wherein the first portion of the radiofrequency power delivery electrode is positioned at a radial peripheral location of the ceramic structure, and wherein the second portion of the radiofrequency power delivery electrode is positioned at a radial center location of the ceramic structure.

7. The electrostatic chuck as recited in claim 3, wherein the radiofrequency power delivery electrode is configured to have multiple variations in distance from the top surface of the ceramic structure as a function of radial distance from the first portion of the radiofrequency power delivery electrode to the second portion of the radiofrequency power delivery electrode,wherein the first portion of the radiofrequency power delivery electrode is positioned at a radial center location of the ceramic structure, and wherein the second portion of the radiofrequency power delivery electrode is positioned at a radial peripheral location of the ceramic structure.

8. The electrostatic chuck as recited in claim 3, wherein the radiofrequency power delivery electrode is configured to step away from the top surface of the ceramic structure in a radial direction extending from the first portion of the radiofrequency power delivery electrode to the second portion of the radiofrequency power delivery electrode.

9. The electrostatic chuck as recited in claim 8, wherein the first portion of the radiofrequency power delivery electrode is positioned at a radial center location of the ceramic structure, and wherein the second portion of the radiofrequency power delivery electrode is positioned at a radial peripheral location of the ceramic structure.

10. The electrostatic chuck as recited in claim 8, wherein the first portion of the radiofrequency power delivery electrode is positioned at a radial peripheral location of the ceramic structure, and wherein the second portion of the radiofrequency power delivery electrode is positioned at a radial center location of the ceramic structure.

11. The electrostatic chuck as recited in claim 3, further comprising: a baseplate positioned within the ceramic structure at a location between the radiofrequency power delivery electrode and the bottom surface of the ceramic structure; a number of electrically conductive structures extending between the baseplate and the radiofrequency power delivery electrode at a number of locations within a peripheral region of the ceramic structure, the number of locations azimuthally spaced apart about a reference line extending perpendicularly through a center location of the top surface of the ceramic structure; and a radiofrequency power supply structure extending from the baseplate to a location outside of the ceramic structure, the radiofrequency power supply structure configured for connection to a radiofrequency power generator.

12. An electrostatic chuck, comprising: a ceramic structure having a top surface, a bottom surface, and a side surface extending between the top surface and the bottom surface, the top surface configured to support a semiconductor wafer during a plasma-based fabrication process; and a plurality of radiofrequency power delivery electrodes embedded within the ceramic structure, the plurality of radiofrequency power delivery electrodes including a first electrode positioned a first distance away from the top surface of the ceramic structure and a second electrode positioned a second distance away from the top surface of the ceramic structure,wherein the plurality of radiofrequency power delivery electrodes are physically separated from each other.

13. The electrostatic chuck as recited in claim 12, wherein each of the plurality of radiofrequency power delivery electrodes has a uniform configuration in an azimuthal direction about a reference line extending perpendicularly through a center location of the top surface of the ceramic structure.

14. The electrostatic chuck as recited in claim 13, wherein the second distance is different than the first distance, and wherein the plurality of radiofrequency power delivery electrodes are configured to step away from the top surface of the ceramic structure in a radial direction extending from a radial center location of the ceramic structure toward a radial peripheral location of the ceramic structure.

15. The electrostatic chuck as recited in claim 13, wherein the second distance is different than the first distance, and wherein the plurality of radiofrequency power delivery electrodes are configured to step toward the top surface of the ceramic structure in a radial direction extending from a radial center location of the ceramic structure toward a radial peripheral location of the ceramic structure.

16. The electrostatic chuck as recited in claim 13, wherein the second distance is substantially equal to the first distance, and wherein the plurality of radiofrequency power delivery electrodes are configured and oriented in a substantially coplanar manner with respect to each other within the ceramic structure.

17. The electrostatic chuck as recited in claim 13, further comprising: a baseplate positioned within the ceramic structure at a location between the plurality of radiofrequency power delivery electrodes and the bottom surface of the ceramic structure; and a number of electrically conductive structures extending between the baseplate and each of the plurality of radiofrequency power delivery electrodes.

18. The electrostatic chuck as recited in claim 17, wherein the number of electrically conductive structures extending between the baseplate and a given one of the plurality of radiofrequency power delivery electrodes are azimuthally spaced apart about a reference line extending perpendicularly through a center location of the top surface of the ceramic structure.

19. The electrostatic chuck as recited in claim 13, further comprising: a plurality of radiofrequency power conveyance devices respectively electrically connected to the plurality of radiofrequency power delivery electrodes, each of the plurality of radiofrequency power conveyance devices connected to a radiofrequency power generator, the plurality of radiofrequency power conveyance devices configured to separately andindependently convey radiofrequency power to a corresponding one of the plurality of radiofrequency power delivery electrodes.

20. The electrostatic chuck as recited in claim 19, wherein each of the radiofrequency power conveyance devices includes at least one electrically conductive structure electrically connected to a corresponding one of the plurality of radiofrequency power delivery electrodes.

21. A method for plasma processing of a semiconductor wafer, comprising: positioning a semiconductor wafer on a wafer support area of an electrostatic chuck, the electrostatic chuck including a ceramic structure having a top surface, a bottom surface, and a side surface extending between the top surface and the bottom surface, the top surface configured to have the wafer support area, the electrostatic chuck including a radiofrequency power delivery electrode embedded within the ceramic structure, the radiofrequency power delivery electrode including a first portion positioned a first distance away from the top surface of the ceramic structure and a second portion positioned a second distance away from the top surface of the ceramic structure, the second distance being different than the first distance; supplying a process gas to a region overlying the semiconductor wafer; supplying a radiofrequency power to the radiofrequency power delivery electrode, the radiofrequency power transforming the process gas into a plasma within the region overlying the semiconductor wafer, wherein the first distance between the first portion of the radiofrequency power delivery electrode and the top surface of the ceramic structure is sized to control one or more of a first voltage on a first portion of the semiconductor wafer overlying the first portion of the radiofrequency power delivery electrode, a first density of the plasma overlying the first portion of the semiconductor wafer, and a first ion flux incident upon the first portion of the semiconductor wafer, so as to minimize a difference between a first etch rate across the first portion of the semiconductor wafer and an average etch rate across an entirety of the semiconductor wafer, and wherein the second distance between the second portion of the radiofrequency power delivery electrode and the top surface of the ceramic structure is sized to control one or more of a second voltage on a second portion of the semiconductor wafer overlying the second portion of the radiofrequency power delivery electrode, a second density of the plasma overlying the second portion of the semiconductor wafer, and a second ion flux incident upon the second portion of the semiconductor wafer, so as to minimize a difference between a second etch rate across the second portion of the semiconductor wafer and the average etch rate across the entirety of the semiconductor wafer.

22. A method for plasma processing of a semiconductor wafer, comprising: positioning a semiconductor wafer on a wafer support area of an electrostatic chuck, the electrostatic chuck including a ceramic structure having a top surface, a bottom surface, and a side surface extending between the top surface and the bottom surface, the wafer support area being on the top surface, the electrostatic chuck including a plurality of radiofrequency power delivery electrodes embedded within the ceramic structure, wherein the plurality of radiofrequency power delivery electrodes are physically separated from each other, the plurality of radiofrequency power delivery electrodes including a first radiofrequency power delivery electrode positioned a first distance away from the top surface of the ceramic structure and a second radiofrequency power delivery electrode positioned a second distance away from the top surface of the ceramic structure, the second distance being different than the first distance; supplying a process gas to a region overlying the semiconductor wafer; supplying a first radiofrequency power to the first radiofrequency power delivery electrode; and supplying a second radiofrequency power to the second radiofrequency power delivery electrode, wherein the first radiofrequency power and the second radiofrequency power transform the process gas into a plasma within the region overlying the semiconductor wafer, wherein the first distance between the first radiofrequency power delivery electrode and the top surface of the ceramic structure is sized to control one or more of a first voltage on a first portion of the semiconductor wafer overlying the first radiofrequency power delivery electrode, a first density of the plasma overlying the first portion of the semiconductor wafer, and a first ion flux incident upon the first portion of the semiconductor wafer, so as to minimize a difference between a first etch rate across the first portion of the semiconductor wafer and an average etch rate across an entirety of the semiconductor wafer, and wherein the second distance between the second radiofrequency power delivery electrode and the top surface of the ceramic structure is sized to control one or more of a second voltage on a second portion of the semiconductor wafer overlying the second radiofrequency power delivery electrode, a second density of the plasma overlying the second portion of the semiconductor wafer, and a second ion flux incident upon the second portion of the semiconductor wafer, so as to minimize a difference between a second etch rate across the second portion of the semiconductor wafer and the average etch rate across the entirety of the semiconductor wafer.

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