High-temperature detachable ultra-high frequency (VHF) electrostatic chuck (ESC) for PVD chambers

Abstract

Embodiments of a substrate support for use in a substrate processing chamber are provided herein. In some embodiments, the substrate support includes an upper assembly having a base plate assembly coupled to a lower surface of a cooling plate, the base plate assembly including a plurality of electrical feedthroughs, the cooling plate including a plurality of openings aligned with the plurality of electrical feedthroughs, an electrostatic chuck disposed on the upper assembly and removably coupled to the cooling plate, the electrostatic chuck having a chucking electrode disposed within the electrostatic chuck and electrically coupled to a first pair of electrical feedthroughs of the plurality of electrical feedthroughs, and an inner tube coupled to the cooling plate and configured to provide an RF supply path to the electrostatic chuck.

Description

[Technical Field]

[0001]

[0001] Embodiments of the present disclosure generally relate to substrate processing apparatus. [Background Art]

[0002]

[0002] A substrate support is used for supporting a substrate within a substrate processing system such as a plasma processing chamber. Types of substrate supports include an electrostatic chuck (ESC) coupled to a lower assembly. An ESC generally includes one or more electrodes embedded within a ceramic chuck body for holding a substrate. The ESC may be removable from the lower assembly to reduce preventive maintenance time and lower replacement costs. However, conventional ESCs are not efficient at combinations of RF frequencies around 60 MHz and high temperatures (400 degrees Celsius or higher). At the aforementioned frequencies and temperatures, the ESC has high impedance, which prevents efficient RF supply passing through the ESC and leads to reduction in throughput.

[0003]

[0003] Accordingly, the present inventors provide an improved substrate support for use at high RF frequencies. [Summary of the Invention]

[0004]

[0004] Embodiments of substrate supports for use in a substrate processing chamber are provided herein. In some embodiments, a substrate support for use in a substrate processing chamber includes an upper assembly having a base plate assembly connected to the lower surface of a cooling plate, the base plate assembly including a plurality of electrical feedthroughs, and the cooling plate including a plurality of openings aligned to the plurality of electrical feedthroughs; an electrostatic chuck disposed on the upper assembly and removably connected to the cooling plate, the electrostatic chuck having chucking electrodes disposed within the electrostatic chuck and electrically coupled to a first pair of electrical feedthroughs of the plurality of electrical feedthroughs; and an inner tube connected to the cooling plate and configured to provide an RF supply path to the electrostatic chuck via at least one of the gap between the electrostatic chuck and the cooling plate, or the back metallization of the electrostatic chuck.

[0005]

[0005] In some embodiments, a substrate support for use in a substrate processing chamber includes an upper assembly having a base plate assembly connected to a cooling plate, the base plate assembly including a plurality of electrical feedthroughs arranged around a back gas opening, and the cooling plate including a plurality of openings aligned to the plurality of electrical feedthroughs; an electrostatic chuck disposed on the upper assembly and removably connected to the cooling plate, the electrostatic chuck having electrodes disposed within the electrostatic chuck and electrically coupled to a first pair of electrical feedthroughs of the plurality of electrical feedthroughs; an inner tube connected to the cooling plate and configured to provide an RF supply path to the electrostatic chuck via at least one of the gap between the electrostatic chuck and the cooling plate, or the back metallization of the electrostatic chuck; and a first resistive heater embedded in the electrostatic chuck and electrically coupled to a second pair of electrical feedthroughs.

[0006]

[0006] In some embodiments, the process chamber includes a chamber body having a substrate support disposed within an internal region of the chamber body, the substrate support comprising: an upper assembly having a base plate assembly connected to a cooling plate, the base plate assembly including a plurality of electrical feedthroughs disposed around a back gas opening, and the cooling plate including a plurality of openings aligned to the plurality of electrical feedthroughs; an electrostatic chuck disposed on the upper assembly and removably connected to the cooling plate, the electrostatic chuck having electrodes disposed within the electrostatic chuck and electrically coupled to a first pair of electrical feedthroughs of the plurality of electrical feedthroughs; and a support assembly having an inner tube connected to the cooling plate and configured to provide an RF supply path to the electrostatic chuck via at least one of the gap between the electrostatic chuck and the cooling plate, or the back metallization of the electrostatic chuck.

[0007]

[0007] Further embodiments of the present disclosure are described below.

[0008]

[0008] By referring to exemplary embodiments of the present disclosure shown in the accompanying drawings, embodiments of the present disclosure summarized above and described in more detail below can be understood. However, the accompanying drawings only illustrate typical embodiments of the present disclosure and should not be considered limiting, as the present disclosure may also permit other equally valid embodiments. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic side view showing a process chamber having a substrate support according to at least some embodiments of the present disclosure. [Figure 2] This is a schematic side view showing a substrate support according to at least some embodiments of the present disclosure. [Figure 3] This is an isometric top view showing a cooling plate according to at least some embodiments of the present disclosure. [Figure 4] This is an isometric bottom view showing a cooling plate according to at least some embodiments of the present disclosure. [Figure 5] This is a cross-sectional side view showing an enlarged view of the upper part of a substrate support according to at least some embodiments of the present disclosure. [Figure 6] This figure shows an interface between an electrostatic chuck and a cooling plate according to at least some embodiments of the present disclosure. [Figure 7] A is a diagram showing a backside metallization pattern on the back side of an electrostatic chuck according to at least some embodiments of the present disclosure, and B is a schematic side view showing an electrostatic chuck having a backside metallization pattern according to at least some embodiments of the present disclosure. [Figure 8] This is an isometric top view showing a base plate according to at least some embodiments of the present disclosure. [Modes for carrying out the invention]

[0010]

[0018] For ease of understanding, the same reference numerals are used to indicate identical elements common to all drawings whenever possible. The drawings are not drawn to scale and may be simplified for clarity. Elements and features of one embodiment may be usefully incorporated into other embodiments without further detail.

[0011]

[0019] Embodiments of a removable electrostatic chuck (ESC) for a physical vapor deposition (PVD) chamber operating at very high RF frequencies are provided herein. These very high RF frequencies may be, for example, about 40 MHz or higher, or about 60 MHz or higher. The inventors have found that PVD chambers operating at very high frequencies can advantageously reduce the resistivity of the films deposited therein. Furthermore, the ESC can also operate at high temperatures (about 400°C or higher).

[0012]

[0020] Figure 1 is a schematic side view showing a process chamber 100 having a substrate support according to at least some embodiments of the present disclosure. In some embodiments, the process chamber 100 is a PVD chamber. However, other types of process chambers configured for different processes can also be used with the electrostatic chuck embodiments described herein, or can be modified for use with the electrostatic chuck embodiments described herein.

[0013]

[0021] The process chamber 100 is a vacuum chamber suitably adapted to maintain a pressure below atmospheric pressure within the internal region 120 of the process chamber 100 during substrate processing. The process chamber 100 includes a chamber body 106 covered by a lid 104 that surrounds a processing region 119 located in the upper half of the internal region 120. The process chamber 100 also includes a process shield 105 that surrounds various chamber components to prevent undesirable reactions between these components and the ionized process material. The chamber body 106 and the lid 104 may be made of a metal such as aluminum. The chamber body 106 may be grounded via a connection to ground 115.

[0014]

[0022] The substrate support 124 is positioned within the internal region 120 to support and hold a substrate 122, such as a semiconductor wafer, or other such substrates that can be held electrostatically. The substrate support 124 may generally include an electrostatic chuck 150 positioned on a pedestal 136. The electrostatic chuck 150 may be made of a ceramic material. The pedestal 136 is connected to a support assembly 103 for supporting the pedestal 136 and the electrostatic chuck 150.

[0015]

[0023] The support assembly 103 generally includes a hollow inner tube 112 and a bellows assembly 110 positioned around the inner tube 112. The inner tube 112 is configured to provide an RF supply path from the RF bias power supply 117 to the electrostatic chuck 150. The inner tube 112 also provides conduits for supplying, for example, backside gas, process gas, fluid, coolant, power, automatic capacitance tuner (ACT), etc., to the electrostatic chuck 150. The bellows assembly 110 may include an outer tube 114 positioned around the inner tube 112. In some embodiments, the outer tube 114 is configured to provide an RF return path from the pedestal 136. In some embodiments, the lower end of the inner tube 112 may protrude beyond the lower end of the outer tube 114 to facilitate electrical connection between the inner tube 112 and the outer tube 114.

[0016]

[0024] The electrostatic chuck 150 includes one or more chucking electrodes 154 disposed therein. The temperature of the substrate 122 can be controlled by adjusting the temperature of the electrostatic chuck 150. For example, the electrostatic chuck 150 can be heated using one or more embedded heating elements (see, for example, Figure 5), such as a resistance heater. In some embodiments, the thickness of the electrostatic chuck 150 may be about 6.0 mm or less.

[0017]

[0025] In some embodiments, the inner tube 112 is connected to a lift mechanism 113, such as an actuator or motor, which provides vertical movement of the electrostatic chuck 150 between an upper processing position (shown in Figure 1) and a lower transfer position (not shown).

[0018]

[0026] The bellows assembly 110 is coupled between the electrostatic chuck 150 and the bottom surface 126 of the process chamber 100, and provides a flexible seal that enables vertical movement of the electrostatic chuck 150 while preventing vacuum leakage from within the process chamber 100. The bellows assembly 110 may also include a lower bellows flange 164 that contacts an O-ring 165 or other suitable sealing element contacting the bottom surface 126 to help prevent chamber vacuum leakage. The bellows assembly 110 may facilitate or partially define an RF return path from the lower assembly 220.

[0019]

[0027] The inner tube 112 provides a conduit for connecting the backside gas supply 141, the chucking power supply 140, and the heater power supply 160 to the electrostatic chuck 150. The backside gas supply 141 is disposed outside the chamber body 106, and supplies gas to the electrostatic chuck 150 via a gas conduit 146 to control the temperature or pressure, and / or temperature profile or pressure profile on the support surface of the electrostatic chuck 150 during use. In some embodiments, the RF power supply 174 and the RF bias power supply 117 are coupled to the electrostatic chuck 150 via respective RF matching networks (only RF matching network 116 is shown). In some embodiments, the substrate support 124 may alternatively include an AC, DC, or RF bias power supply.

[0020]

[0028] The RF supply path and the RF return path are arranged coaxially along the support assembly 103. For example, the RF supply path extends along the inner tube 112 functioning as an RF electrode. The inner tube 112 may be maintained at a constant temperature. The RF return path extends along the outer tube 114 disposed around the inner tube 112. The arrangement of the inner tube 112 and the outer tube 114 forms a neutral region or electric field-free region inside the inner tube 112, reducing RF loss caused by RF coupling to electrostatic chuck wires, heater wires, thermocouple wires, and the like.

[0021]

[0029] The substrate lift 130 may include lift pins 109 attached to a platform 108 connected to a shaft 111 coupled to a second lift mechanism 132 for raising and lowering the substrate lift 130, so that the substrate 122 may be placed on or removed from the electrostatic chuck 150. The electrostatic chuck 150 may include through holes for receiving the lift pins 109. A bellows assembly 131 is coupled between the substrate lift 130 and a bottom surface 126, and provides a flexible seal that maintains the vacuum of the process chamber during vertical movement of the substrate lift 130.

[0022]

[0030] The process chamber 100 is coupled to and in fluid communication with a vacuum system 184 that includes a throttle valve (not shown) and a vacuum pump (not shown) used to evacuate the process chamber 100. The pressure within the process chamber 100 may be adjusted by regulating the throttle valve and / or the vacuum pump. The process chamber 100 is also coupled to and in fluid communication with a process gas supply 118 that may supply one or more process gases into the process chamber 100 for processing a substrate 122 disposed therein.

[0023]

[0031] A target 138 is disposed in a processing region 119 opposite the substrate support 124, and at least partially defines a process region therebetween. The target 138 includes a cathode surface defined by a surface of the target 138 facing toward the processing region. The substrate support 124 has a support surface having a surface substantially parallel to the sputtering surface of the target 138. The target 138 is connected to one or both of a DC power supply 190 and / or an RF power supply 174. The DC power supply 190 may apply a bias voltage to the target 138 relative to a process shield 105.

[0024]

[0032] The target 138 includes a sputtering plate 142 attached to a backing plate 144. The sputtering plate 142 contains the material to be sputtered onto the substrate 122. The backing plate 144 is made of a metal such as stainless steel, aluminum, copper-chromium, or copper-zinc. The backing plate 144 may be made of a material with a thermal conductivity high enough to dissipate the heat generated in the target 138, which is formed from eddy currents generated in the sputtering plate 142 and the backing plate 144, and from the collision of high-energy ions from the generated plasma onto the sputtering plate 142.

[0025]

[0033] In some embodiments, the process chamber 100 includes a magnetic field generator 156 that forms a magnetic field around the target 138 to improve sputtering of the target 138. The capacitively generated plasma may be enhanced by the magnetic field generator 156, which can provide the process chamber 100 with a rotating magnetic field having an axis of rotation perpendicular to the plane of the substrate 122, for example, of a plurality of magnets 151 (e.g., permanent magnets or electromagnetic coils). The magnetic field generator 156 may include a motor assembly that rotates the plurality of magnets 151. The magnetic field generator 156 can generate a magnetic field near the target 138 to increase the ion density of the processing area 119 and improve sputtering of the target material. The plurality of magnets 151 may be arranged in the cavity 153 of the lid 104. To cool the target 138, a coolant such as water may be placed in the cavity 153 or circulated within the cavity 153.

[0026]

[0034] The process chamber 100 includes a process kit 102 that surrounds various chamber components to prevent undesirable reactions between the components and the ionized process material. The process kit 102 includes a process shield 105 that surrounds a substrate support 124 and a target 138 and at least partially defines the processing area 119. For example, the process shield 105 may define the outer boundary of the processing area 119. In some embodiments, the process shield 105 is made of a metal such as aluminum.

[0027]

[0035] In some embodiments, the process kit 102 includes a deposition ring 170 resting on the outer edge of the electrostatic chuck 150. In some embodiments, the process kit 102 includes a covering ring 180 positioned on a process shield 105, forming a winding gas channel between them. In some embodiments, at the processing position, the radially inner portion of the covering ring 180 rests on the deposition ring 170 to reduce or prevent plasma leakage between them.

[0028]

[0036] In some embodiments, multiple ground loops 172 are positioned between the process shield 105 and the pedestal 136. The ground loops 172 are generally loops of conductive material configured to ground the process shield 105 to the pedestal 136 when the substrate support 124 is in the processing position, or alternatively, they may include conductive straps, spring members, etc. In some embodiments, the multiple ground loops 172 are connected to the outer lip of the pedestal 136 such that, in the processing position, the ground loops 172 contact the process shield 105 and ground the process shield 105. In some embodiments, in the transport position, the ground loops 172 are positioned at a distance from the process shield 105.

[0029]

[0037] The process chamber 100 is fluidly connected to a vacuum system 19, which includes a throttle valve (not shown) and a vacuum pump (not shown) used to evacuate the process chamber 100. The pressure inside the process chamber 100 can be adjusted by adjusting the throttle valve and / or the vacuum pump. The process chamber 100 is also fluidly connected to a process gas supply unit 118, which can supply one or more process gases to the process chamber 100 to process the substrate 122 placed inside it. A slit valve 148 can be connected to the chamber body 106 and aligned with an opening in the side wall of the chamber body 106 to facilitate the transfer of the substrate 122 into and out of the chamber body 106.

[0030]

[0038] During operation, while the DC power supply 190 supplies power to the target 138 and other chamber components connected to the DC power supply 190, the RF power supply 174 applies a voltage to the sputtering gas (e.g., from the process gas supply unit 118) to form a sputtering gas plasma. The formed plasma strikes and impacts the sputtering surface of the target 138, sputtering material from the target 138 onto the substrate 122. In some embodiments, the frequency of the RF energy supplied by the RF power supply 174 may be in the range of about 2 MHz to about 60 MHz or higher. In some embodiments, multiple (i.e., two or more) RF power supplies may be provided to supply RF energy at multiple of the above frequencies. An additional RF power supply (e.g., an RF bias power supply 117) may also be used to supply a bias voltage to the substrate support 124 and attract ions from the plasma toward the substrate 122. The RF bias power supply 117 can supply RF power in a very high frequency range, for example, about 13 MHz or higher, or about 40 MHz or about 60 MHz or higher.

[0031]

[0039] Figure 2 is a schematic side view showing a substrate support 124 according to at least some embodiments of the present disclosure. The pedestal 136 may include an upper assembly 210 and a lower assembly 220. The upper assembly 210 generally includes a base plate assembly 208 connected to a cooling plate 212. In some embodiments, the base plate assembly 208 includes a plurality of electrical feedthroughs 214 connected to a base plate 216 and extending through openings in the base plate 216.

[0032]

[0040] The cooling plate 212 includes a plurality of openings 218 aligned with a plurality of electrical feedthroughs 214. In some embodiments, the plurality of openings 218 are located in a central region of the cooling plate 212. In some embodiments, the central region includes a central projection 230 extending from the lower surface of the cooling plate 212. In some embodiments, the plurality of electrical feedthroughs 214 are located in the central projection 230 of the cooling plate 212. In some embodiments, the central projection 230 is disc-shaped, and the outer diameter of the central projection 230 is substantially the same as the outer diameter of the base plate 216.

[0033]

[0041] An electrostatic chuck 150 is positioned above the upper assembly 210 and is removably connected to a cooling plate 212. In some embodiments, terminals 222 are aligned with each of the electrical feedthroughs 214, facing each of the electrical feedthroughs 214 from the underside of the electrostatic chuck 150, and electrically coupling each of the electrical feedthroughs 214 to an electronic component (e.g., chucking electrode 154, heater element 508, etc.) located in the electrostatic chuck 150. In some embodiments, a flexible connector 228 is positioned in each of the multiple openings 218 and configured to connect each terminal 222 to each of the multiple electrical feedthroughs 214. The flexible connector 228 is configured to maintain the electrical connection between the terminals 222 and the multiple electrical feedthroughs 214 during thermal expansion and / or thermal contraction between the upper assembly 210 and the electrostatic chuck 150. The flexible connector 228 may include a first end 830 (see Figure 8) having a first opening facing the electrostatic chuck 150 to receive one of the terminals 222, and a second end 832 having a second opening facing the base plate 216 to receive a conductive core of one of the plurality of electrical feedthroughs 214.

[0034]

[0042] In some embodiments, the electrostatic chuck 150 includes five terminals 222, and the base plate assembly 208 includes five of a plurality of electrical feedthroughs 214, two or a first pair for electrically coupling one or more chucking electrodes 154, two or a second pair for a single-zone heater, and one for a center tap configured to measure the stray voltage of the substrate 122 when a voltage is applied, for example, a bias voltage or a voltage from an RF power supply and when a voltage is applied to ACT. In some embodiments, the electrostatic chuck 150 includes seven terminals 222: two for one or more chuck electrodes 154, four for a two-zone heater, and one for a center tap. The electrostatic chuck 150 and upper assembly 210 may be configured to accommodate more or fewer than five to seven terminals 222. In some embodiments, the central region 232 of the electrostatic chuck 150 includes an interface ring 236 extending from its lower surface. The terminals 222 may be positioned radially outward around the interface ring 236. In some embodiments, the terminals 222 extend into one of each of the multiple openings 218 in the cooling plate 212.

[0035]

[0043] Figure 5 is an enlarged cross-sectional side view showing the upper part 500 of the substrate support 124 according to at least some embodiments of the present disclosure. One or more heater elements 508 that heat the electrostatic chuck 150 along one or more heating zones may be arranged on the electrostatic chuck 150. One or more heater elements 508 are connected to a heater power supply 160. In some embodiments, a gap 510 is provided between the electrostatic chuck 150 and the cooling plate 212 to advantageously minimize heat transfer between the electrostatic chuck 150 and the cooling plate 212.

[0036]

[0044] During use, the gap 510 is pumped down, for example, via a vacuum system 184, to form a true air gap. The size of the gap 510 is large enough to minimize contact heat transfer and small enough to allow RF coupling from the cooling plate 212 to the electrostatic chuck 150 through the gap 510. In some embodiments, the gap 510 is about 0.002 to about 0.006 inches. In some embodiments, the cooling plate 212 includes a plurality of minimum contact area (MCA) pads 506 for supporting the electrostatic chuck 150. In some embodiments, the plurality of MCA pads 506 includes about 5 to about 15 MCA pads. In some embodiments, the MCA pads 506 are arranged along two or more concentric circles. For example, in some embodiments, the MCA pads 506 include three pads along an inner concentric circle and six pads along an outer concentric circle. In some embodiments, the MCA pads 506 are arranged along a constant interval. In some embodiments, at least some of the MCA pads 506 are aligned along a common radius of the cooling plate 212.

[0037]

[0045] Figure 6 shows an interface between an electrostatic chuck 150 and a cooling plate 212 according to at least some embodiments of the present disclosure. The electrostatic chuck 150 is removably connected to the cooling plate 212 for ease of replacement and cleaning. In some embodiments, the electrostatic chuck 150 is connected to the cooling plate 212 in a central region 232 of the electrostatic chuck 150 such that the lower surface 512 of the electrostatic chuck 150 is spaced apart from the upper surface 518 of the cooling plate 212. In some embodiments, the electrostatic chuck 150 is connected to the cooling plate 212 via a fastener 602 that extends into the cooling plate 212 through a central through-hole 632 in the central region 232 of the electrostatic chuck 150. In some embodiments, the central through-hole 632 includes a ledge 634 for supporting the head of the fastener 602.

[0038]

[0046] In some embodiments, a fastener 602 secures the electrostatic chuck 150 to the cooling plate 212. In some embodiments, the cooling plate 212 includes a cavity 608 formed in the bottom surface of a central recess 314. In some embodiments, a nut plate 606 is positioned in the cavity 608. In some embodiments, the fastener 602 extends through the nut plate 606, and the external threads of the fastener 602 engage with a threaded opening 610 in the cooling plate 212 to connect the electrostatic chuck 150 to the cooling plate 212.

[0039]

[0047] The fastener 602 can be removed to detach the electrostatic chuck 150 from the cooling plate 212. In some embodiments, to disengage the electrical contacts between the electrostatic chuck 150 and the base plate assembly 208, the nut plate 606 includes an internal thread 612 that engages with an external thread of a tool (not shown) for lifting the nut plate 606. When the nut plate 606 is lifted, it is pressed against the electrostatic chuck 150, disengaging all electrical contacts. In some embodiments, if the cooling plate 212 includes an MCA pad 506, the interface ring 236 of the electrostatic chuck 150 may be spaced apart from the wall of the central recess 314 and the nut plate 606. In some embodiments, if the cooling plate 212 does not include an MCA pad 506, the nut plate 606 provides the only contact area between the electrostatic chuck 150 and the cooling plate 212, which can advantageously minimize thermal coupling. In some embodiments, the nut plate 606 may contact the interface ring 236 to support the central region 232 of the electrostatic chuck 150, and the MCA pad 506 may support the peripheral region of the electrostatic chuck 150.

[0040]

[0048] In some embodiments, the central through-hole 632 is connected to a gas conduit 146 for supplying backside gas from the backside gas supply unit 141 to the upper surface of the electrostatic chuck 150. In some embodiments, the fastener 602 includes a gas passage 638 positioned through it to provide a flow path for backside gas to the upper surface of the electrostatic chuck 150. A gas plug (not shown) can be positioned in the central through-hole 632 above the fastener 602.

[0041]

[0049] Figure 7A shows a backside metallization pattern on the backside of an electrostatic chuck 150 according to at least some embodiments of the present disclosure. Figure 7B is a schematic side view showing an electrostatic chuck 150 having a backside metallization pattern according to at least some embodiments of the present disclosure. In some embodiments, RF is coupled from the cooling plate 212 to the electrostatic chuck 150 via the backside metallization 702 of the electrostatic chuck 150, which is in physical contact with the cooling plate 212 and provides RF coupling. The backside metallization 702 can eliminate gaps 510 and improve RF supply. The backside metallization 702 may contain any metal suitable for RF coupling.

[0042]

[0050] In some embodiments, by arranging one or more RF contacts 720 between the back metallization 702 and the cooling plate 212, the RF supply path extends from one or more RF contacts 720 to the back metallization 702, and the back metallization 702 does not come into complete contact with the cooling plate 212, thereby reducing thermal coupling. In some embodiments, one or more RF contacts are arranged along a ring 710. The back metallization 702 may include any suitable pattern arranged on the lower surface 512 of the electrostatic chuck 150. For example, the back metallization 702 may include a plurality of branches 718 extending from a central region 232 to the outer region 730 or outer surface 732 of the electrostatic chuck 150. In some embodiments, the plurality of branches 718 extend non-linearly. In some embodiments, a second plurality of branches 728 are arranged between the plurality of branches 718 in the outer region 730. In some embodiments, one or more RF contacts 720 are present for each of the multiple branches 718 and each of the second multiple branches 728.

[0043]

[0051] Returning to Figure 2, the support assembly 103 is connected to the cooling plate 212 and includes an inner tube 112 configured to provide an RF supply path to the electrostatic chuck 150 via at least one of the gap 510 between the electrostatic chuck 150 and the cooling plate 212 or the back metallization 702 of the electrostatic chuck 150. A gas conduit 146 extends through the inner tube 112. In some embodiments, the back gas supply section 141 is fluidly coupled to the lower surface 512 of the electrostatic chuck 150 via the gas conduit 146 of the base plate assembly 208, a gas opening 268 penetrating the cooling plate 212, and a central through-hole 632 of the electrostatic chuck 150. In some embodiments, a temperature measuring device 266 extends through the inner tube 112. In some embodiments, the temperature measuring device 266 penetrates the base plate 216 and extends through the cooling plate 212 into the electrostatic chuck 150. In some embodiments, the temperature measuring device 266 extends into the interface ring 236 of the electrostatic chuck 150. In some embodiments, the temperature measuring device 266 extends through the central projection 230 of the cooling plate 212. The temperature measuring device 266 may be a thermocouple, an optical temperature measuring device, or the like.

[0044]

[0052] In some embodiments, the lower assembly 220 of the pedestal 136 includes a ceramic block 224 positioned on a housing 226 of the lower assembly 220. In some embodiments, the housing 226 includes an outer lip 246 surrounding the ceramic block 224. In some embodiments, the housing 226 includes an outer ledge 248 extending radially outward from the outer lip 246. The outer ledge 248 may provide a bonding surface for a plurality of ground loops 172. The housing 226 is connected to an outer tube 114. In some embodiments, the housing 226 is positioned on a bellows weld 258 connected to a bellows assembly 110.

[0045]

[0053] In some embodiments, the cooling plate 212 includes a coolant channel 240 for circulating a coolant within it to control the temperature of the electrostatic chuck 150. A coolant supply line 242 may extend from the coolant supply unit 280 to the coolant channel 240. In some embodiments, the coolant supply line 242 extends through the inner tube 112. The cooling plate 212 will be described in more detail below with reference to Figures 3 and 4.

[0046]

[0054] In some embodiments, the lower assembly 220 of the pedestal 136 includes an RF supply tray 250 connected at its lower end to an inner tube 112 and at its upper end to a cooling plate 212. In some embodiments, the RF supply tray 250 has a bowl-like shape and extends from the inner tube 112 to near the ceramic block 224. In some embodiments, the central projection 230 of the base plate 216 and the cooling plate 212 may be located within the RF supply tray 250. In some embodiments, the RF supply tray 250 includes an outer lip 252 extending radially outward from the top of the RF supply tray 250. In some embodiments, the outer lip 252 is located between the cooling plate 212 and the ceramic block 224. In some embodiments, the lower assembly 220 includes a cover plate 254 connected to the base plate 216 within the RF supply tray 250 and configured to cover a plurality of electrical feedthroughs 214. In some embodiments, the cover plate 254 is made of a polymer material.

[0047]

[0055] In some embodiments, the RF supply path extends from the inner tube 112 to the RF supply tray 250, the outer surface of the cooling plate 212, the upper surface 518 of the cooling plate 212, and the electrostatic chuck 150. In some embodiments, the RF return path extends from the processing area 119 to the upper surface of the housing 226, and the outer tube 114. The ceramic block 224 is configured to electrically isolate the RF supply path and the RF return path. In some embodiments, the housing 226 is made of a metal such as aluminum. In some embodiments, the inner tube 112 is made of a metal such as aluminum.

[0048]

[0056] Figure 3 is an isometric top view showing a cooling plate 212 according to at least some embodiments of the present disclosure. In some embodiments, the cooling plate 212 is made of stainless steel or aluminum. In some embodiments, the top surface 518 of the cooling plate 212 has an emissivity that can be modified as desired to control heat loss. For example, the top surface 518 has a higher emissivity in the central portion 310 than in the peripheral portion 320, which further helps to control temperature uniformity throughout the electrostatic chuck 150. Higher emissivity can be achieved through any suitable process, such as machining, melting, or anodizing.

[0049]

[0057] The cooling plate 212 may include a plurality of radial channels 304 on its upper surface 518, which help to exhaust air between the cooling plate 212 and the electrostatic chuck 150, creating a vacuum between them. In some embodiments, the upper surface 518 includes a central recess 314 for accommodating the interface ring 236 of the electrostatic chuck 150. In some embodiments, one of the radial channels 304A may extend into the central recess 314 to help exhaust air between the interface ring 236 and the cooling plate 212. In some embodiments, the plurality of radial channels 304 include six channels. In some embodiments, the plurality of radial channels 304 extend through openings 218 for a plurality of electrical feedthroughs 214. The cooling plate 212 may include an opening 306 for accommodating the lift pin 109.

[0050]

[0058] Figure 4 is an isometric bottom view showing a cooling plate 212 according to at least some embodiments of the present disclosure. In some embodiments, the bottom surface 402 of the cooling plate 212 includes a central projection 230 and a coolant channel 240 positioned around the central projection 230. The coolant channel 240 may extend along any suitable path for cooling the cooling plate 212. In some embodiments, the coolant channel 240 extends in a wavy or non-circular shape. In some embodiments, the coolant channel 240 includes an inlet 420 and an outlet 422. In some embodiments, the cooling plate 212 includes one or more alignment features 412 for aligning the cooling plate 212 with the base plate 216. In some embodiments, the central projection 230 includes an opening 406 for a temperature measuring device 266. In some embodiments, a gas opening 268 penetrating the cooling plate 212 may include one or more curved sections that appropriately separate the gas opening 268 from the temperature measuring device 266. To seal the gas opening 268, an O-ring groove 430 can be placed around the gas opening 268.

[0051]

[0059] Figure 8 is an isometric top view showing a base plate assembly 208 according to at least some embodiments of the present disclosure. In some embodiments, the base plate 216 of the base plate assembly 208 includes a plurality of fastener openings 810 for connecting the base plate 216 to a cooling plate 212. The base plate 216 includes a gas opening 812 connected to a gas conduit 146. The gas opening 812 is aligned with a gas opening 268 in the cooling plate 212. In some embodiments, a plurality of electrical feedthroughs 214 may be located close to the outer surface of the base plate 216. O-ring grooves 818 may be located around each of the plurality of electrical feedthroughs 214 to seal the plurality of openings 218 in the cooling plate 212. O-ring grooves 806 may be located around a temperature measuring device 266. Figure 8 shows one of the flexible connectors 228. In some embodiments, the flexible connector 228 includes a plurality of slits 834 to allow the first end 830 to move relative to the second end 832.

[0052]

[0060] While the foregoing applies to embodiments of the present disclosure, it is possible to devise other further embodiments of the present disclosure without departing from its basic scope.

Claims

1. A substrate support for use in a substrate processing chamber, An upper assembly having a base plate assembly connected to the lower surface of a cooling plate, wherein the base plate assembly includes a plurality of electrical feedthroughs, and the cooling plate includes a plurality of openings aligned with the plurality of electrical feedthroughs, An electrostatic chuck disposed on the upper assembly and removably connected to the cooling plate, the electrostatic chuck having chucking electrodes disposed within the electrostatic chuck and electrically coupled to a first pair of electrical feedthroughs of the plurality of electrical feedthroughs, Connected to the aforementioned cooling plate, The gap between the electrostatic chuck and the cooling plate, or Metallization of the back side of the electrostatic chuck An inner tube configured to provide an RF supply path to the electrostatic chuck via at least one of the following: An outer tube arranged around the inner tube, A lower assembly having a ceramic block positioned on the housing A substrate support comprising the outer tube connected to the housing to provide an RF return path, and the ceramic block positioned between the housing and the cooling plate to separate the RF supply path from the RF return path.

2. The substrate support according to claim 1, wherein the electrostatic chuck is connected to the cooling plate in the central region of the electrostatic chuck such that the lower surface of the electrostatic chuck is spaced apart from the upper surface of the cooling plate.

3. The substrate support according to claim 1, wherein the electrostatic chuck has an interface ring extending from the lower surface of the electrostatic chuck, the interface ring includes a central through-hole, the central through-hole is fluidly coupled to an opening in the cooling plate, and the back side gas is configured to flow through the central through-hole.

4. The substrate support according to claim 1, wherein the cooling plate is made of stainless steel or aluminum.

5. A substrate support according to any one of claims 1 to 4, wherein a thermocouple is positioned to penetrate the central protrusion of the cooling plate and extends into the electrostatic chuck.

6. The substrate support according to any one of claims 1 to 4, further comprising a flexible connector including a first end opening for receiving a terminal extending from the lower surface of the electrostatic chuck and a second end opening for receiving a conductive core of one of the plurality of electrical feedthroughs.

7. A substrate support for use in a substrate processing chamber, An upper assembly having a base plate assembly connected to the lower surface of a cooling plate, wherein the base plate assembly includes a plurality of electrical feedthroughs, and the cooling plate includes a plurality of openings aligned with the plurality of electrical feedthroughs, An electrostatic chuck disposed on the upper assembly and removably connected to the cooling plate, the electrostatic chuck having chucking electrodes disposed within the electrostatic chuck and electrically coupled to a first pair of electrical feedthroughs of the plurality of electrical feedthroughs, Connected to the aforementioned cooling plate, The gap between the electrostatic chuck and the cooling plate, or Metallization of the back side of the electrostatic chuck An inner tube configured to provide an RF supply path to the electrostatic chuck via at least one of the following: Equipped with, The lower surface of the cooling plate is a substrate support including a central protrusion and cooling channels arranged around the central protrusion.

8. The substrate support according to claim 7, wherein the outer diameter of the central protrusion is substantially the same as the outer diameter of the base plate assembly.

9. The substrate support according to any one of claims 1 to 4, wherein a first resistive heater is embedded in the electrostatic chuck and electrically coupled to a second pair of electrical feedthroughs.

10. A substrate support for use in a substrate processing chamber, An upper assembly having a base plate assembly connected to the lower surface of a cooling plate, wherein the base plate assembly includes a plurality of electrical feedthroughs, and the cooling plate includes a plurality of openings aligned with the plurality of electrical feedthroughs, An electrostatic chuck disposed on the upper assembly and removably connected to the cooling plate, the electrostatic chuck having chucking electrodes disposed within the electrostatic chuck and electrically coupled to a first pair of electrical feedthroughs of the plurality of electrical feedthroughs, Connected to the aforementioned cooling plate, The gap between the electrostatic chuck and the cooling plate, or Metallization of the back side of the electrostatic chuck An inner tube configured to provide an RF supply path to the electrostatic chuck via at least one of the following: Equipped with, The upper surface of the cooling plate is a substrate support having a higher emissivity in the central part than in the peripheral part.

11. The substrate support according to any one of claims 1 to 4, wherein the lower surface of the electrostatic chuck includes a metallization pattern for providing an RF contact with the cooling plate.

12. The substrate support according to any one of claims 1 to 4, wherein the lower surface of the electrostatic chuck includes five terminals arranged around the interface ring and aligned with the plurality of electrical feedthroughs.

13. A substrate support for use in a substrate processing chamber, An upper assembly having a base plate assembly connected to the lower surface of a cooling plate, wherein the base plate assembly includes a plurality of electrical feedthroughs, and the cooling plate includes a plurality of openings aligned with the plurality of electrical feedthroughs, An electrostatic chuck disposed on the upper assembly and removably connected to the cooling plate, the electrostatic chuck having chucking electrodes disposed within the electrostatic chuck and electrically coupled to a first pair of electrical feedthroughs of the plurality of electrical feedthroughs, Connected to the aforementioned cooling plate, The gap between the electrostatic chuck and the cooling plate, or Metallization of the back side of the electrostatic chuck An inner tube configured to provide an RF supply path to the electrostatic chuck via at least one of the following: Equipped with, A substrate support comprising an electrostatic chuck connected to a cooling plate via a fastener extending through the central region of the electrostatic chuck, the fastener extending through a nut plate, and the external thread of the fastener engaging with a threaded opening in the cooling plate to connect the electrostatic chuck to the cooling plate.

14. It is a process chamber, A chamber body having a substrate support according to any one of claims 1 to 4 disposed within the internal region of the chamber body, wherein a plurality of electrical feedthroughs are arranged around the rear gas opening. A process chamber equipped with a process chamber.

15. It is a process chamber, The chamber body comprises a substrate support, and the substrate support is An upper assembly having a base plate assembly connected to the lower surface of a cooling plate, wherein the base plate assembly includes a plurality of electrical feedthroughs, and the cooling plate includes a plurality of openings aligned with the plurality of electrical feedthroughs, An electrostatic chuck disposed on the upper assembly and removably connected to the cooling plate, the electrostatic chuck having chucking electrodes disposed within the electrostatic chuck and electrically coupled to a first pair of electrical feedthroughs of the plurality of electrical feedthroughs, Connected to the aforementioned cooling plate, The gap between the electrostatic chuck and the cooling plate, or Metallization of the back side of the electrostatic chuck An inner tube configured to provide an RF supply path to the electrostatic chuck via at least one of the following: Equipped with, The substrate support is located within the internal region of the chamber body, and the plurality of electrical feedthroughs are arranged around the rear gas opening. The process chamber further comprises a lower assembly including a ceramic block disposed on a housing, the housing including an outer lip surrounding the ceramic block.

16. The process chamber according to claim 15, further comprising a process shield disposed around the substrate support, wherein a plurality of ground loops are connected to the housing and configured to contact the process shield when the substrate support is in the upper processing position.

17. The process chamber according to claim 14, wherein the plurality of electrical feedthroughs are arranged on the central projection of the cooling plate.

18. The process chamber according to claim 14, further comprising a rear gas supply unit fluidly coupled to the lower surface of the electrostatic chuck via a central through-hole of the electrostatic chuck and a gas conduit of the base plate assembly.

19. The process chamber according to claim 14, wherein a flexible connector is positioned between the electrostatic chuck and each electrical feedthrough to allow thermal expansion of the electrostatic chuck while maintaining electrical coupling.

Images