Electrostatic chuck for use in semiconductor processing - Patent Application 20070123633

Abstract

A semiconductor substrate processing apparatus, an electrostatic chuck, and a substrate pedestal module are provided that allow semiconductor substrates to be used at temperatures exceeding approximately 550°C. A semiconductor substrate processing apparatus includes a vacuum chamber (102), a process gas source (118) in fluid communication with the vacuum chamber for supplying process gas, a showerhead module (104) through which the process gas from the process gas source is supplied, and a substrate pedestal module (106). The substrate pedestal module includes a platen made of a ceramic material having an upper surface for supporting a semiconductor substrate (108) during processing, a ceramic stem, and coplanar electrodes embedded in the platen. The electrodes include an inner electrostatic clamping electrode and an outer RF electrode having a ring electrode and leads extending radially from the ring electrode to a central portion of the platen. The ceramic material of the platen and the electrodes comprise a unitary structure fabricated in a single sintering step.

Description

[Technical field]

[0001] The present invention relates to semiconductor substrate processing equipment for processing semiconductor substrates, and finds particular application in plasma enhanced chemical vapor deposition processing equipment operable to deposit thin films. [Background technology]

[0002] Semiconductor substrate processing equipment is used to process semiconductor substrates by techniques including etching, physical vapor deposition (PVD), chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD), atomic layer deposition (ALD), plasma enhanced atomic layer deposition (PEALD), pulsed deposited layer (PDL), plasma enhanced pulsed deposited layer (PEPDL), and resist removal. One type of semiconductor substrate processing equipment is a plasma processing equipment that includes a reaction chamber including an upper electrode and a lower electrode, where radio frequency (RF) power is applied between the electrodes to excite a process gas into a plasma for processing a semiconductor substrate in the reaction chamber. Summary of the Invention

[0003] Disclosed herein is a semiconductor substrate processing apparatus for processing semiconductor substrates, comprising: a vacuum chamber including a processing zone in which a semiconductor substrate may be processed; a process gas source in fluid communication with the vacuum chamber for supplying process gas into the vacuum chamber; a showerhead module through which process gas from the process gas source is supplied to the processing zone of the vacuum chamber; a substrate pedestal module including a platen made of a ceramic material having an upper surface configured to support a semiconductor substrate during processing; a stem made of a ceramic material having an upper stem flange supporting the platen; and coplanar electrodes embedded within the platen, the electrodes including an outer RF electrode and an inner electrostatic clamping electrode, the outer RF electrode including a ring electrode and at least one radially extending lead extending from the ring electrode to a central portion of the platen, the ceramic material of the platen and the electrodes being of a unitary structure fabricated in a single sintering step.

[0004] According to one embodiment, the platen includes first and second D-shaped electrostatic clamp electrodes inside a ring electrode, with radially extending leads extending diagonally across the platen and connected to the ring electrode at two locations 180° apart, with the first and second D-shaped electrodes facing each other across the radially extending leads. The platen can include a first terminal at the center of the platen, a second terminal radially offset from the first terminal, and a third terminal radially offset from the first terminal, with the first terminal electrically connected to the radially extending leads of the ring electrode, the second terminal electrically connected to the first D-shaped electrode, and the third terminal electrically connected to the second D-shaped electrode. The first, second, and third terminals can extend axially through openings in the platen, and the second and third terminals can be aligned along a diagonal line passing through the location of the first terminal.

[0005] In another configuration, the platen can include first, second, third, and fourth electrostatic clamping electrodes inside a ring electrode, and at least one radially extending feed strip includes two feed strips extending diagonally across the platen, each feed strip connected to the ring electrode at two locations 180° apart, and the feed strips intersect at the center of the platen with the first, second, third, and fourth electrostatic clamping electrodes located between the diagonally extending feed strips.

[0006] The platen can be made of any suitable ceramic material and the electrodes can be made of any suitable conductive material. For example, the platen can be made of aluminum nitride and the electrodes can be made of tungsten. The platen can include three through holes configured to accommodate the lift pins and the platen can have a diameter of at least 300 mm.

[0007] In embodiments in which the electrostatic clamping electrode is a D-shaped electrode, the ring electrode may be separated from the D-shaped electrodes by a first continuous wall of ceramic material extending around the first D-shaped electrode and a second continuous wall of ceramic material extending around the second D-shaped electrode. The first and second walls of ceramic material may have the same width, and the width of the first and second walls of ceramic material may be less than the width of the radially extending lead wire.

[0008] Also disclosed herein is an electrostatic chuck useful for processing semiconductor substrates in a vacuum chamber including a processing zone in which the semiconductor substrate may be processed. The electrostatic chuck includes a platen made of a ceramic material having an upper surface configured to support a semiconductor substrate during processing, and a coplanar electrode embedded in the platen. The electrode includes an outer RF electrode and an inner electrostatic clamping electrode, the outer RF electrode including a ring electrode and at least one radially extending lead extending from the ring electrode to a central portion of the platen, and the ceramic material of the platen and the electrode are comprised of a unitary structure fabricated in a single sintering step. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram illustrating an overview of a chemical deposition apparatus according to embodiments disclosed herein.

[0010] [Diagram 2] FIG. 2 shows a top view of a ceramic high temperature chuck with power distribution circuitry located below three coplanar electrodes.

[0011] [Diagram 3] FIG. 3 is an exploded view of the coplanar electrodes shown in FIG. 2 and the power distribution circuitry below the electrodes.

[0012] [Figure 4] FIG. 4 is a bottom view of the chuck shown in FIG.

[0013] [Diagram 5]FIG. 5 is a top perspective view of a ceramic high-temperature electrostatic chuck with a platen having an outer ring electrode including radially extending leads that can be electrically connected to a terminal centrally located on the underside of the platen.

[0014] [Figure 6] FIG. 6 is a bottom perspective view of the platen shown in FIG.

[0015] [Figure 7] FIG. 7 is a cutaway view showing the electrical connections of the platen shown in FIG.

[0016] [Figure 8] FIG. 8 is a perspective view of the underside of the platen shown in FIG.

[0017] [Figure 9] FIG. 9 is a cross-sectional view of the platen shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] In the following detailed description, numerous specific embodiments are described to provide a thorough understanding of the apparatus and methods disclosed herein. However, it will be apparent to one of ordinary skill in the art that the present embodiments may be practiced without these specific details or by using alternative elements or processes. In other instances, well-known processes, procedures, and / or components have not been described in detail so as not to unnecessarily obscure aspects of the embodiments disclosed herein. As used herein, the term "about" refers to ±10%.

[0019] As described below, the present embodiments provide an apparatus and associated methods for processing semiconductor substrates in a semiconductor substrate processing apparatus, such as a chemical vapor deposition apparatus or a plasma enhanced chemical vapor deposition apparatus. The apparatus and methods are particularly applicable for use in conjunction with high temperature processing of semiconductor substrates, such as high temperature deposition processes in which the semiconductor substrate being processed is heated to temperatures above about 550° C., for example, from about 550° C. to about 650° C. or higher.

[0020] The embodiments disclosed herein are preferably, but not limited to, plasma enhanced chemical deposition equipment (ie, a PECVD equipment, a PEALD equipment, or a PEPDL equipment).

[0021] FIG. 1 provides a simplified block diagram illustrating various semiconductor substrate plasma processing apparatus components configured to perform embodiments disclosed herein. As shown, the semiconductor substrate plasma processing apparatus 100 includes a vacuum chamber 102 responsible for confining a plasma in a processing zone, where the plasma is generated by a capacitor-type system including a showerhead module 104 having an upper RF electrode (not shown) in cooperation with a substrate pedestal module 106 having a lower RF electrode (not shown) therein. At least one RF generator is operable to provide RF energy in the processing zone above a top surface of a semiconductor substrate 108 in the vacuum chamber 102 to excite process gases provided in the processing zone of the vacuum chamber 102 into a plasma, so that a plasma deposition process is performed in the vacuum chamber 102. For example, a high frequency RF generator 110 and a low frequency RF generator 112 may each be connected to a matching network 114 connected to the upper RF electrode of the showerhead module 104, so that RF energy may be provided to the processing zone above the semiconductor substrate 108 in the vacuum chamber 102.

[0022] The power and frequency of the RF energy provided to the interior of the vacuum chamber 102 by the matching network 114 is sufficient to generate a plasma from the process gas. In one embodiment, both the high frequency RF generator 110 and the low frequency RF generator 112 are used, and in an alternative embodiment, only the high frequency RF generator 110 is used. In some processes, the high frequency RF generator 110 may be operated at a frequency between about 2-100 MHz, and in a preferred embodiment, at 13.56 MHz or 27 MHz. The low frequency RF generator 112 may be operated between about 50 kHz-2 MHz, and in a preferred embodiment, at about 350-600 kHz. The process parameters may be scaled based on the volume of the chamber, the substrate size, and other factors. Similarly, the flow rate of the process gas may depend on the free volume of the vacuum chamber or processing zone.

[0023] The top surface of the substrate pedestal module 106 supports the semiconductor substrate 108 during processing within the vacuum chamber 102. The substrate pedestal module 106 may include a chuck to hold the semiconductor substrate and / or lift pins to raise and lower the semiconductor substrate before, during, and / or after the deposition and / or plasma treatment process. In another embodiment, the substrate pedestal module 106 may include a carrier ring to raise and lower the semiconductor substrate before, during, and / or after the deposition and / or plasma treatment process. The chuck may be an electrostatic chuck, a mechanical chuck, or various other types of chucks available for industrial and / or research use. Details of lift pin assemblies for substrate pedestal modules including electrostatic chucks can be found in commonly assigned U.S. Pat. No. 8,840,754, which is incorporated herein by reference in its entirety. Details of carrier rings for substrate pedestal modules can be found in commonly assigned U.S. Pat. No. 6,860,965, which is incorporated herein by reference in its entirety. A backside gas supply 116 is operable to supply a heat transfer gas or a purge gas to a region below the underside of the semiconductor substrate through the substrate pedestal module 106 during processing. The substrate pedestal module 106 includes a lower RF electrode therein, which is preferably grounded during processing, and in alternative embodiments, the lower RF electrode may be supplied with RF energy during processing.

[0024] To process a semiconductor substrate in the vacuum chamber 102 of the semiconductor substrate plasma processing apparatus 100, process gases may be introduced from a process gas source 118 through an inlet 120 and a showerhead module 104 into the vacuum chamber 102 where the process gases may be formed into a plasma using RF energy to deposit a film on the top surface of the semiconductor substrate. In one embodiment, multiple source gas lines 122 may be connected to a heated manifold 124. The gases may be premixed or separately delivered to the chamber. Appropriate valves and mass flow control mechanisms are used to ensure that the correct gases are delivered through the showerhead module 104 during semiconductor substrate processing. During processing, a backside heat transfer gas or a purge gas is delivered to an area below the bottom surface of the semiconductor substrate supported on the substrate pedestal module 106. Preferably, the process is at least one of a chemical vapor deposition process, a plasma enhanced chemical vapor deposition process, an atomic layer deposition process, a plasma enhanced atomic layer deposition process, a pulsed deposition layer process, or a plasma enhanced pulsed deposition layer process.

[0025] In certain embodiments, a system controller 126 is used to control process conditions during deposition, post-deposition treatment, and / or other process operations. The controller 126 typically includes one or more memory devices and one or more processors. The processor may include a CPU or computer, analog and / or digital input / output connections, stepper motor control boards, etc.

[0026] In certain embodiments, the controller 126 controls all of the operation of the apparatus. The system controller 126 executes system control software that includes a set of instructions for controlling the timing of process operations, the operating frequencies and powers of the low frequency RF generator 112 and the high frequency RF generator 110, the flow rates and temperatures of the precursor and inert gases and their relative mixtures, the temperatures of the plasma-exposed surfaces of the semiconductor substrate 108 supported on the top surface of the substrate pedestal module 106 and the showerhead module 104, the pressure of the vacuum chamber 102, and other parameters of a particular process. In some embodiments, other computer programs stored in memory devices associated with the controller may be used.

[0027] High temperature chucks typically include a ceramic platen and a small diameter ceramic stem bonded to the underside of the platen, see, for example, commonly assigned U.S. Patent Application Publication Nos. 2016 / 0340781, 2016 / 0336213, and 2016 / 0333475, each of which is incorporated herein by reference in its entirety.

[0028] FIG. 2 shows a platen 200 having three coplanar electrodes 202, 204, 206 embedded within a ceramic body (not shown). Electrode 202 is an outer ring electrode that surrounds D-shaped electrostatic clamp electrodes 204 and 206. To provide power to the outer ring electrode 202, a power distribution circuit 208 (see FIG. 3) is embedded within the ceramic body below the electrodes 202, 204, 206, and a vertically extending conductive via 210 connects the outer ring electrode 202 to the power distribution circuit 208. The power distribution circuit 208 includes an outer ring 212 below the outer ring electrode 202 and an arm 214 that extends diagonally across the outer ring 212. The power distribution circuit 208 allows power to be provided from a power supply terminal (not shown) located near the center of the underside of the platen. The electrostatic clamping electrodes 204 , 206 are connected to a power supply terminal (not shown) located near the center of the underside of the platen in the space between the arms 214 of a power distribution circuit 208 .

[0029] 4 shows the underside of the platen 200, where the arrangement of the electrodes 202, 204, 206 can be seen with the terminals 216, 218, 220 located inside a hollow ceramic stem 222 attached to a ceramic body 224. The terminal 216 is attached to the electrostatic clamping electrode 204, the terminal 220 is attached to the electrostatic clamping electrode 206, and the terminal 218 is attached to the intersection of the arms 214 of the power distribution circuit 208. Thus, to manufacture the platen 200, multiple sintering steps must be performed to embed the conductive power distribution circuit within the ceramic body 224 below the electrodes 202, 204, 206, so that the arms 214 and ring 212 may act as inductors, creating undesirable inductance effects during wafer processing. The ceramic body 224 includes three through holes 226 sized to receive lift pins (not shown) for raising and lowering wafers over the support surface of the platen 200.

[0030] FIG. 5 shows an electrostatic chuck comprising a platen 300 having an outer ring electrode 302 surrounding electrostatic clamping electrodes 304, 306. The outer ring electrode 302 is designed to eliminate the need for power distribution circuitry. As shown, the outer ring electrode 302 includes radially extending leads (power supply strips) 302a that extend diagonally across the ring electrode 302. The leads 302a allow a terminal (not shown) at the bottom center of the platen 300 to be electrically connected to the outer ring electrode 302. The electrostatic chuck is preferably a bipolar chuck having one or more pairs of clamping electrodes with opposite polarity. For example, the electrostatic chuck may include four clamping electrodes separated by supply strips that extend diagonally across the outer ring electrode 302. In such a case, the supply strips are vertical and the clamping electrodes would be located inside the four quadrants formed by the outer ring electrode 302 and the diagonally extending supply strips.

[0031] 6 shows the underside of platen 300 with hollow ceramic stem 322 attached to ceramic body 324. Terminal 316 is attached to electrostatic clamping electrode 304, terminal 320 is attached to electrostatic clamping electrode 306, and terminal 318 is attached to lead 302a of ring-shaped outer electrode 302. Ceramic body 324 includes three through holes 326 sized to receive lift pins (not shown) for raising and lowering a wafer above and below the support surface of platen 300.

[0032] The platen 300 can be used as a high temperature electrostatic chuck in a substrate support module for serial processing of individual semiconductor wafers, with the platen 300 being a unitary structure fabricated in a single sintering step to provide coplanar electrostatic and RF clamping electrodes and one or more heaters below the coplanar electrodes. As previously mentioned, in conventional platen designs, the power distribution circuitry buried below the RF and electrostatic clamping electrodes includes power distribution electrode arms that create undesirable inductance effects during wafer processing. Eliminating the power distribution electrode arms eliminates out-of-plane inductors and simplifies the manufacturing process by performing a single sintering step. Additionally, providing a feed strip 302a that extends diagonally across the outer ring electrode 302 can minimize the adverse effects of disturbances to the RF field above the wafer being processed.

[0033] Platen 300 and stem 322 are preferably made of a ceramic material, and the bottom surface of platen 300 may be joined to a flange at the top end of stem 322, such as by brazing, friction welding, diffusion bonding, or other suitable techniques. The interior of stem 322 may contain power supply leads, one or more thermocouple leads, and one or more gas supply tubes that provide an inert gas, such as argon (Ar), or a heat transfer gas, such as helium (He), that is delivered via suitable fluid passages to the underside of a semiconductor substrate disposed on the support surface of platen 300.

[0034] The power leads may be one or more supply rods that supply radio frequency (RF), direct current (DC), and / or alternating current (AC) to the electrodes embedded in the platen 300. The platen 300 is preferably a unitary structure of sintered ceramic material such as aluminum oxide (alumina), yttria, aluminum nitride, boron nitride, silicon oxide, silicon carbide, silicon nitride, titanium oxide, zirconium oxide, or other suitable materials or combinations. Each electrode preferably has a planar configuration and is preferably made of a conductive metallic material (e.g., tungsten, molybdenum, tantalum, niobium, cobalt) or a conductive non-metallic material (aluminum oxide-tantalum carbide, aluminum oxide-silicon carbide, aluminum nitride-tungsten, aluminum nitride-tantalum, yttrium oxide-molybdenum). The electrodes may be formed from a powder material that is co-fired with the ceramic material of the platen. For example, the electrodes may be formed from a conductive paste that is co-fired with a layer of ceramic material that forms the body of the platen. For example, the paste may include conductive metal powders of nickel (Ni), tungsten (W), molybdenum (Mo), titanium (Ti), manganese (Mn), copper (Cu), silver (Ag), palladium (Pd), platinum (Pt), and rhodium (Rh). Alternatively, the electrodes may be formed from a deposited material having a desired electrode pattern, or from a deposited film that is etched to form the desired electrode pattern. Furthermore, the electrodes may include preformed grids, plates, wire meshes, or other suitable electrode materials and / or configurations. In one embodiment, the electrodes include at least one electrostatic clamping electrode powered by a DC power source to provide a DC chucking voltage (e.g., about 200 to about 2000 volts), at least one RF electrode powered by an RF power source to provide an RF bias voltage (e.g., one or more frequencies from about 400 KHz to about 60 MHz at power levels of about 50 to about 3000 watts), and / or at least one electrode powered by DC and RF power sources via a suitable circuit.

[0035] The platen can be made by placing flush electrodes in a ceramic material and performing a single sintering step to embed the electrodes in the sintered ceramic material. Examples of ceramic chuck manufacturing techniques can be found in commonly assigned U.S. Pat. Nos. 5,880,922, 6,483,690, and 8,637,194, the disclosures of which are incorporated herein by reference. For example, the outer ring electrodes with integral radially extending leads and the ESC electrodes can be screen printed on an aluminum nitride green sheet, an aluminum nitride green sheet or other suitable dielectric material can be placed on the screen printed electrodes, and the resulting compact can be hot pressed and sintered to form the platen. Terminals in holes extending under the sintered ceramic material can be bonded to each electrode, and a stem can be bonded to the underside of the platen.

[0036] 7 shows a platen 300 including conductive electrodes 304, 306, such as conductive grids, a feed strip electrode 302a electrically connected to an outer ring electrode 302 (not shown) embedded therein, and a hollow ceramic support stem 322. The platen 300 and stem 322 are preferably made of a ceramic material, such as aluminum nitride, and the bottom surface of the platen 300 is joined to the top end of the stem 322, such as by brazing, friction welding, diffusion bonding, or other suitable technique. A centrally located conductive tube 330 is disposed inside the stem 322, and the top end of the tube 330 is electrically connected to the embedded feed strip electrode 302a. The outlet of the tube 330 is in fluid communication with a gas passage 342 (see FIG. 9) on the top surface of the platen 300. The tube 330 may be supplied with an inert gas, such as argon (Ar) or nitrogen (N2), or a heat transfer gas, such as helium (He), which is delivered to the underside of a semiconductor substrate (not shown) supported on the platen 300 via gas passages 342. The exterior of the tube 330 may be sealed to the platen 300 by a hermetic seal. The interior of the stem 322 also houses other components, such as an electrical supply rod 338 that supplies power to other electrodes, such as resistive heaters 340a, 340b, and an additional supply rod 336 that supplies power to the electrostatic clamping electrodes 304, 306 in the platen 300. The rod 336 may be hollow to supply gas through an outlet to the underside of a wafer supported on the platen 300.

[0037] During processing of a semiconductor substrate, such as deposition of a film on a silicon wafer supported on the platen 300, the platen 300 may cycle between temperatures ranging from about 20° C. to over 500° C. For processing a 300 mm wafer, the platen 300 may have a maximum thickness of about 1 inch and a diameter of about 15 inches, the stem 322 may have a diameter of about 3 inches, and the distance between the bottom of the stem 322 and the top surface of the platen 300 may be about 5 inches. The tubes 330, 336 may have a diameter of about 4 mm and a length of about 7 to 8 inches. The inside of the stem 322 houses components such as electrical feeds, such as palladium / rhodium (Pd / Rh) coated stainless steel or nickel (Ni) rods.

[0038] The supply rods 338 may be solid metal rods, such as nickel (Ni) rods, positioned at circumferentially spaced positions inside the inner surface of the stem 322, and two outer conductive supply rods 336 (which may optionally be hollow rods for supplying gas to the top surface of the platen 300) are electrically connected to the electrostatic clamping electrodes 304, 306. The solid supply rods 338 may supply power to resistive heaters 340a, 340b embedded in the platen 300 at positions below the electrostatic clamping electrodes 304, 306. The electrical connections between the central tube 330 and the supply strips 302a, between the supply rods 336 and the electrodes 304, 306, and between the supply rods 338 and the heaters 340a, 340b may include solid terminals / studs / sockets as disclosed in commonly assigned U.S. Pat. No. 9,088,085, the disclosure of which is incorporated herein by reference. During manufacture of the platen 300, the tube 330 and feed rods 336, 338 may be bonded to the platen 300 and electrodes 302, 304, 306 via suitable sintering and / or brazing techniques.

[0039] 8 illustrates a bottom perspective view of the substrate pedestal module 106. As shown, a central tube 330, a feed rod 338, and an outer tube 336 extend outwardly from the lower end of the stem 322.

[0040] 9 is a cross-sectional view of the substrate pedestal module 106. As shown, the central tube 330 is electrically connected to the feed strip electrode 302a, and the two feed rods 338 are electrically connected to one or more resistive heaters 340a, 340b embedded in the platen 300 at locations below the electrodes 302, 304, 306. For example, one pair of feed rods 338 can be connected to an inner heater and another pair of feed rods 338 can be connected to an outer heater. If desired, a single heater or two or more heaters can be embedded in the platen 300 in any desired geometric arrangement. The central tube 330 delivers gas to an outlet 342 on the top surface of the platen 300.

[0041] Although the substrate pedestal module of the semiconductor substrate processing apparatus has been described in detail with reference to specific embodiments thereof, it will be apparent to those skilled in the art that various changes and modifications can be made thereto and equivalents can be employed without departing from the scope of the appended claims.

Claims

1. 1. An electrostatic chuck comprising: a platen of ceramic material having an upper surface configured to support a substrate; a first D-shaped electrostatic clamping electrode embedded in the platen; a second D-shaped electrostatic clamping electrode embedded in the platen; an outer ring RF electrode embedded in the platen, the outer ring RF electrode surrounding the first and second D-shaped electrostatic clamping electrodes and including a feed strip extending diagonally across the platen between the first and second D-shaped electrostatic clamping electrodes, the outer ring RF electrode and the first and second D-shaped electrostatic clamping electrodes being coplanar; a first terminal at a center of the platen and electrically connected to the feed strip; a second terminal radially offset from the first terminal and electrically connected to the first D-shaped electrostatic clamping electrode; a third terminal radially offset from the first terminal and electrically connected to the second D-shaped electrostatic clamping electrode; a stem of ceramic material attached to the platen, an interior of the stem housing an electrical feed rod with the first terminal, the second terminal, and the third terminal extending from the stem to an underside of the feed strip, to the first D-shaped electrostatic clamping electrode, and to the second D-shaped electrostatic clamping electrode, respectively, the electrical feed rod being hollow.

2. 2. The electrostatic chuck of claim 1, The first and second D-shaped electrostatic clamping electrodes have opposite polarities.

3. 2. The electrostatic chuck of claim 1, the first and second D-shaped electrostatic clamping electrodes are configured to be supplied with a DC chucking voltage of 200V to 2000V to electrostatically clamp the substrate, and the outer ring RF electrode is configured to be powered by an RF power source configured to provide an RF bias voltage at a power of 50W to 3000W and a frequency of 400kHz to 60MHz.

4. 10. The electrostatic chuck of claim 1, further comprising: a plurality of resistive heaters embedded in the platen at locations below the first and second D-shaped electrostatic clamping electrodes, the plurality of resistive heaters electrically connected to a fourth terminal separate from the first, second, and third terminals.

5. 2. The electrostatic chuck of claim 1, 11. An electrostatic chuck comprising: a first D-shaped electrostatic clamping electrode, a second D-shaped electrostatic clamping electrode, and an outer ring RF electrode, each of which comprises a wire mesh.

6. 2. The electrostatic chuck of claim 1, The platen includes three or more holes configured to receive lift pins.

7. 1. An electrostatic chuck comprising: a ceramic platen having an upper surface configured to support a substrate during processing; a ceramic stem attached to the ceramic platen; a plurality of electrostatic clamping electrodes embedded in the ceramic platen, the plurality of electrostatic clamping electrodes including a first electrostatic clamping electrode and a second electrostatic clamping electrode; an outer ring electrode embedded in the ceramic platen and surrounding the plurality of electrostatic clamping electrodes; a feed strip electrode connected to the outer ring electrode; a first terminal at a center of the ceramic platen and electrically connected to the feed strip of the outer ring electrode; a second terminal radially offset from the first terminal and electrically connected to the first electrostatic clamping electrode; a third terminal radially offset from the first terminal and electrically connected to the second electrostatic clamping electrode; a conductive tube located inside the ceramic stem and connected to an underside of the feed strip electrode; one or more resistive heaters embedded in the ceramic platen beneath the plurality of electrostatic clamping electrodes, the outer ring electrode, and the feed strip electrode; one or more first electrical supply rods within the ceramic stem configured to supply power to the one or more resistive heaters; and one or more second electrical supply rods within the ceramic stem configured to supply power to the one or more electrostatic clamping electrodes, wherein the one or more second electrical supply rods are hollow.

8. 8. The electrostatic chuck of claim 7, an electrostatic chuck, wherein the plurality of electrostatic clamping electrodes, the outer ring electrode, and the feed strip electrode each comprise a wire mesh;

9. 1. An electrostatic chuck comprising: a platen of ceramic material having an upper surface configured to support the substrate during processing; a coplanar electrode embedded in the platen, the coplanar electrode including an outer RF electrode and an inner electrostatic clamp electrode, the outer RF electrode including a ring electrode having at least one radially extending feed strip extending from the ring electrode to a central portion of the platen; and a plurality of hollow supply rods configured to supply power to the coplanar electrodes, wherein at least a first hollow supply rod is configured to supply power to the inner electrostatic clamping electrode from a DC power supply and at least a second hollow supply rod is configured to supply power to the outer RF electrode from an RF power supply.

10. 10. The electrostatic chuck of claim 9, the platen includes an inner electrostatic clamping electrode including first and second D-shaped electrostatic clamping electrodes inside the ring electrode, the at least one radially extending feed strip includes a single feed strip extending diagonally across the platen and connected to the ring electrode at two locations 180° apart, the first and second D-shaped electrostatic clamping electrodes being on opposite sides of the single feed strip.

11. 11. The electrostatic chuck of claim 10, the platen includes a first terminal at a center of the platen, a second terminal radially offset from the first terminal, and a third terminal radially offset from the first terminal, the first terminal electrically connected to the single feed strip, the second terminal electrically connected to the first D-shaped electrostatic clamping electrode, and the third terminal electrically connected to the second D-shaped electrostatic clamping electrode.

12. 11. The electrostatic chuck of claim 10, 11. An electrostatic chuck comprising: a ring electrode separated from the first and second D-shaped electrostatic clamping electrodes by a first continuous wall of ceramic material extending around the first D-shaped electrostatic clamping electrode and a second continuous wall of ceramic material extending around the second D-shaped electrostatic clamping electrode, the first and second continuous walls of ceramic material having a first width, and the single feed strip having a second width.

13. 13. The electrostatic chuck of claim 12, The first width is less than the second width.

14. 10. The electrostatic chuck of claim 9, an electrostatic chuck, the platen comprising first, second, third, and fourth electrostatic clamping electrodes inside the ring electrode, the at least one radially extending feed strip including two feed strips extending diagonally across the platen, the two feed strips connected to the ring electrode at two locations 180° apart, the two feed strips connected to the ring electrode at two locations 180° apart, the two feed strips intersecting at a center of the platen with the first, second, third, and fourth electrostatic clamping electrodes located between the two feed strips.

15. 10. The electrostatic chuck of claim 9, further comprising:

1. An electrostatic chuck comprising: one or more resistive heaters embedded in the platen at locations below the coplanar electrode, the one or more resistive heaters connected to one or more terminals extending axially through one or more openings in the platen.

16. 10. The electrostatic chuck of claim 9, 1. An electrostatic chuck, wherein: (a) the platen comprises aluminum nitride; or (b) the platen comprises through holes configured to accommodate lift pins; or (c) the platen has a diameter of at least 300 mm; or a combination of at least two of (a) through (c).

17. 10. The electrostatic chuck of claim 9, the ceramic material of the platen and the coplanar electrode comprise a unitary structure.

18. 10. The electrostatic chuck of claim 9, each said coplanar electrode comprising a wire mesh.

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