Electrostatic chuck for use in semiconductor processing

Abstract

SOLUTION: A semiconductor substrate processing apparatus includes: 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 a 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; and a substrate pedestal module. The substrate pedestal module includes: a platen made of ceramic material having an upper surface configured to support a semiconductor substrate thereon during processing; a stem made of ceramic material; and coplanar electrodes embedded in the platen. The electrodes includes an outer RF electrode and inner electrostatic clamping electrodes. The outer RF electrode includes a ring-shaped electrode and a radially extending lead extending from the ring-shaped electrode to a central portion of the platen. Therein the ceramic material of the platen and the electrodes comprise a unitary body made in a single sintering step.SELECTED DRAWING: Figure 1

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 with 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 semiconductor substrates 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 semiconductor substrates 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 the semiconductor substrate during processing; a stem made of a ceramic material having an upper stem flange that supports the platen; and coplanar electrodes embedded in the platen, the electrodes including an outer RF electrode and an inner electrostatic clamping electrode, the outer RF electrode including a ring-shaped electrode and at least one radially extending lead wire extending from the ring-shaped electrode to a central portion of the platen, the ceramic material of the platen and the electrodes comprising a unitary structure fabricated in a single sintering step.

[0004] According to one embodiment, the platen includes first and second D-shaped electrostatic clamping electrodes inside a ring electrode, with radially extending leads extending diagonally across the platen and connected to the ring electrodes 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, where the first terminal is electrically connected to the radially extending leads of the ring electrodes, the second terminal is electrically connected to the first D-shaped electrode, and the third terminal is 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 the 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 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 can be separated from the D-shaped electrode 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 can have the same width, and the widths of the first and second walls of ceramic material are less than the width of the radially extending lead wires.

[0008] Also disclosed herein is an electrostatic chuck useful for processing semiconductor substrates in a vacuum chamber including a processing zone where the semiconductor substrates 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-shaped electrode and at least one radially extending lead wire extending from the ring-shaped electrode to a central portion of the platen, and the ceramic material of the platen and the electrode comprise a unitary structure fabricated in a single sintering step. [Brief explanation 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] [Figure 2] FIG. 2 shows a top view of a ceramic high temperature chuck with power distribution circuitry located below three coplanar electrodes.

[0011] [Figure 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] [Figure 5]FIG. 5 is a top perspective view of a ceramic high-temperature electrostatic chuck with a platen in which an outer ring electrode includes 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 INVENTION

[0018] In the following detailed description, numerous specific embodiments are set forth to provide a thorough understanding of the devices 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 method for processing semiconductor substrates in a semiconductor substrate processing system, such as a chemical vapor deposition system or a plasma-enhanced chemical vapor deposition system. The apparatus and method 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., e.g., 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 systems (ie, PECVD systems, PEALD systems, or PEPDL systems).

[0021] 1 provides a simplified block diagram illustrating various components of a semiconductor substrate plasma processing apparatus configured to implement embodiments disclosed herein. As shown, the semiconductor substrate plasma processing apparatus 100 includes a vacuum chamber 102 responsible for confining a plasma within 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 supply RF energy into the processing zone above an upper surface of a semiconductor substrate 108 within the vacuum chamber 102 to excite process gases supplied into the processing zone of the vacuum chamber 102 into a plasma, thereby performing a plasma deposition process within 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, thereby supplying RF energy to the processing zone above the semiconductor substrate 108 within the vacuum chamber 102.

[0022] The power and frequency of the RF energy supplied 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, while in an alternative embodiment, only the high-frequency RF generator 110 is used. In some processes, the high-frequency RF generator 110 may operate at a frequency between about 2 and 100 MHz, with preferred embodiments at 13.56 MHz or 27 MHz. The low-frequency RF generator 112 may operate between about 50 kHz and 2 MHz, with preferred embodiments at about 350 and 600 kHz. Process parameters may be scaled based on chamber volume, 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 upper 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, although 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 into the vacuum chamber 102 from a process gas source 118 via an inlet 120 and a showerhead module 104, where the process gases may be formed into a plasma using RF energy, thereby depositing a film on the upper 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 supplied separately to the chamber. Appropriate valves and mass flow control mechanisms are used to ensure the correct gases are delivered through the showerhead module 104 during semiconductor substrate processing. During processing, a backside heat transfer gas or purge gas is supplied to a region below the lower surface of a semiconductor substrate supported on a 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 process, or a plasma-enhanced pulsed deposition 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, including a set of instructions for controlling the timing of processing 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 top 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 on 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, and 206 embedded within a ceramic body (not shown). Electrode 202 is an outer ring electrode surrounding D-shaped electrostatic clamp electrodes 204 and 206. To supply 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, and 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 extending diagonally across the outer ring 212. The power distribution circuit 208 allows power to be supplied 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 the power distribution circuit 208 .

[0029] 4 shows the underside of the platen 200, revealing the arrangement of electrodes 202, 204, and 206, along with terminals 216, 218, and 220 located inside hollow ceramic stems 222 attached to a ceramic body 224. Terminal 216 is attached to electrostatic clamping electrode 204, terminal 220 is attached to electrostatic clamping electrode 206, and terminal 218 is attached to the intersection of arms 214 of power distribution circuit 208. Therefore, fabricating platen 200 requires multiple sintering steps to embed the conductive power distribution circuit within ceramic body 224 below electrodes 202, 204, and 206, which can result in arms 214 and ring 212 acting as inductors and creating undesirable inductance effects during wafer processing. 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 platen 200.

[0030] FIG. 5 illustrates an electrostatic chuck including 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 center of the underside 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 polarities. 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 positioned within 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. The platen 300 is a single structure fabricated in a single sintering step, providing coplanar electrostatic clamping and RF 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 implementing a single sintering step. Additionally, providing a feed strip 302a extending diagonally across the outer ring electrode 302 minimizes 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), which 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 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 (e.g., aluminum oxide-tantalum carbide, aluminum oxide-silicon carbide, aluminum nitride-tungsten, aluminum nitride-tantalum, yttrium oxide-molybdenum oxide). 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 contain conductive metal powders of nickel (Ni), tungsten (W), molybdenum (Mo), titanium (Ti), manganese (Mn), copper (Cu), silver (Ag), palladium (Pd), platinum (Pt), or 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 comprise preformed grids, plates, wire mesh, 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 a power level from about 50 to about 3000 watts), and / or at least one electrode powered by both DC and RF power sources via a suitable circuit.

[0035] The platen can be fabricated by placing coplanar electrodes within a ceramic material and performing a single sintering step to embed the electrodes within 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, an outer ring electrode with integrated radially extending leads and the ESC electrodes can be screen-printed onto an aluminum nitride green sheet, an aluminum nitride green sheet or other suitable dielectric material can be placed over the screen-printed electrodes, and the resulting compact can be hot-pressed and sintered to form the platen. Terminals within holes extending below 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 a conductive grid, 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 can be supplied with an inert gas, such as argon (Ar) or nitrogen (N), 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 can be sealed to the platen 300 by a hermetic seal. Other components are also housed inside the stem 322, such as an electrical supply rod 338 that supplies power to other electrodes, such as resistive heaters 340 a, 340 b, and an additional supply rod 336 that supplies power to the electrostatic clamping electrodes 304, 306 in the platen 300. The rod 336 can be hollow to supply gas to the underside of a wafer supported on the platen 300 through an outlet.

[0037] During processing of semiconductor substrates, such as depositing a film on a silicon wafer supported on the platen 300, the platen 300 may cycle through temperatures ranging from approximately 20°C to over 500°C. To process a 300mm wafer, the platen 300 may have a maximum thickness of approximately 1 inch and a diameter of approximately 15 inches, the stem 322 may have a diameter of approximately 3 inches, and the distance between the bottom of the stem 322 and the top surface of the platen 300 may be approximately 5 inches. The tubes 330, 336 may have a diameter of approximately 4 mm and a length of approximately 7-8 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 upper 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 within the platen 300 at locations below the electrostatic clamping electrodes 304, 306. The electrical connections between the central tube 330 and the supply strip 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 shows a bottom perspective view of the substrate pedestal module 106. As shown, the central tube 330, the feed rod 338, and the outer tube 336 extend outward 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 two feed rods 338 are electrically connected to one or more resistive heaters 340a, 340b embedded within the platen 300 at locations below the electrodes 302, 304, and 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 within 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 a 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 may be made thereto and equivalents may be employed without departing from the scope of the appended claims.

Claims

1. A semiconductor substrate processing apparatus for processing a semiconductor substrate, 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 a process gas into the vacuum chamber; a showerhead module through which process gas from the process gas source is delivered 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, and an electrostatic chuck including a stem made of a ceramic material having an upper stem flange supporting the platen; 11. A semiconductor substrate processing apparatus comprising: a platen including 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 feed strip extending from the ring electrode to a central portion of the platen, the ceramic material of the platen and the electrodes being comprised of a unitary structure fabricated in a single sintering step.

2. 2. The semiconductor substrate processing apparatus of claim 1, wherein the platen includes first and second D-shaped electrostatic clamping electrodes inside the ring electrode, the radially extending feed strip extends diagonally across the platen and is connected to the ring electrode at two locations 180° apart, the first and second D-shaped electrodes facing each other across the radially extending feed strip.

3. 3. The semiconductor substrate processing apparatus of claim 2, wherein 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 radially extending feed strip of the ring electrode, the second terminal electrically connected to the first D-shaped electrode, and the third terminal electrically connected to the other D-shaped electrode.

4. 4. The semiconductor substrate processing apparatus of claim 3, wherein the first, second and third terminals extend axially through an opening in the platen, and the second and third terminals are aligned along a diagonal line passing through the position of the first terminal.

5. 10. The semiconductor substrate processing apparatus of claim 1, wherein: (a) the platen is made of aluminum nitride and the electrodes are made of tungsten; (b) the platen includes three through holes configured to accommodate lift pins; and / or (c) the platen has a diameter of at least 300 mm.

6. 11. The semiconductor substrate processing apparatus of claim 1 further comprising coplanar resistive heaters embedded within the platen below the coplanar electrodes, each of the resistive heaters connected to a terminal extending from an underside of the platen, the coplanar electrodes connected to terminals extending from the underside of the platen, the terminals of the resistive heaters and the terminals of the electrodes connected to an axially extending feed rod located inside a hollow ceramic stem, the feed rod extending beyond a lower end of the hollow ceramic stem.

7. 2. The semiconductor substrate processing apparatus of claim 1, wherein the platen includes first, second, third, and fourth D-shaped electrostatic clamping electrodes inside the ring electrode, and wherein the at least one radially extending feed strip comprises two feed strips extending diagonally across the platen, each of the feed strips being 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.

8. 3. The semiconductor substrate processing apparatus of claim 2, wherein the ring electrode is separated from the D-shaped electrode 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 having the same width, and the width of the first and second walls of ceramic material is less than a width of the radially extending feed strip.

9. 2. The semiconductor substrate processing apparatus of claim 1 further comprising: coplanar resistive heaters embedded within said platen beneath said coplanar electrodes, each of said resistive heaters connected to a pair of terminals extending axially through openings in said platen.

10. 1. An electrostatic chuck useful for processing a semiconductor substrate in a vacuum chamber including a processing zone in which the semiconductor substrate may be processed, comprising: a platen made of a ceramic material having an upper surface configured to support a semiconductor substrate during processing; a coplanar electrode embedded within the platen; the electrodes include an outer RF electrode and an inner electrostatic clamping electrode, the outer RF electrode including a ring electrode and at least one radially extending feed strip extending from the ring electrode to a central portion of the platen, and the ceramic material of the platen and the electrodes comprise a unitary structure fabricated in a single sintering step.

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

12. 11. The electrostatic chuck of claim 10, wherein the platen includes first, second, third, and fourth D-shaped electrostatic clamping electrodes inside the ring electrode, and the at least one radially extending feed strip comprises two feed strips extending diagonally across the platen, each of the feed strips being connected to the ring electrode at two locations 180 degrees 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.

13. 12. The electrostatic chuck of claim 11, wherein 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 radially extending feed strip of the ring electrode, the second terminal electrically connected to the first D-shaped electrode, and the third terminal electrically connected to the other D-shaped electrode.

14. 11. The electrostatic chuck of claim 10, further comprising coplanar resistive heaters embedded in the platen beneath the coplanar electrodes, each of the resistive heaters connected to a terminal that extends axially through an opening in the platen.

15. 11. The electrostatic chuck of claim 10, wherein: (a) the platen is made of aluminum nitride and the electrode is made of tungsten; (b) the platen includes through holes configured to receive lift pins; and / or (c) the platen has a diameter of at least 300 mm.

16. 12. The electrostatic chuck of claim 11, wherein the ring electrode is separated from the first and second 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 having the same width.

17. 17. The electrostatic chuck of claim 16, wherein a width of the first and second walls of ceramic material is less than a width of the radially extending feed strip.

18. 11. A substrate pedestal module comprising: a platen as recited in claim 10; and a hollow ceramic stem having an upper end diffusion bonded to the underside of the platen.

19. 20. The substrate pedestal module of claim 18, further comprising coplanar resistive heaters embedded in the platen below the coplanar electrodes, each of the resistive heaters connected to a terminal extending from an underside of the platen, the coplanar electrodes connected to terminals extending from the underside of the platen, the terminals of the resistive heaters and the terminals of the electrodes connected to an axially extending feed rod located inside the hollow ceramic stem, the feed rod extending beyond a lower end of the hollow ceramic stem.

20. 20. The substrate pedestal module of claim 18, wherein the platen includes first and second D-shaped electrostatic clamping electrodes inwardly of the ring electrode, and wherein the at least one radially extending feed strip comprises a single feed strip extending diagonally across the platen and connected to the ring electrode at two locations 180 degrees apart, the first and second D-shaped electrodes opposing each other across the single feed strip.

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