Coolant channel designs for substrate supports to remove local nonuniformities

Abstract

A substrate support for supporting a substrate includes a baseplate and a coolant channel arranged in the baseplate. The coolant channel comprises a plurality of turns distributed between an outer diameter of the substrate support to a center of the substrate support, and an inlet for a coolant connected to an outermost turn of the plurality of turns. The inlet is tilted relative to an axis perpendicular to a plane in which the coolant channel lies in the substrate support. In one example, a feeding assembly is connected to an inner edge of an outermost turn of the plurality of turns to feed a coolant to the outermost turn of the coolant channel. In another example, a plenum is connected to an outermost turn of the plurality of turns to supply a coolant to the outermost turn of the coolant channel.

Description

COOLANT CHANNEL DESIGNS FOR SUBSTRATE SUPPORTS TO REMOVE LOCAL NONUNIFORMITIESCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 556,165, filed on February 21 , 2024. The entire disclosure of the application referenced above is incorporated herein by reference.FIELD

[0002] The present disclosure relates generally to substrate processing systems and more particularly to coolant channel designs for substrate supports to remove local nonuniformities.BACKGROUND

[0003] The background description provided here is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.

[0004] Substrate processing systems may be used to perform etching, deposition, and / or other treatment of substrates such as semiconductor wafers. Examples of the processes that may be performed on a substrate include, but are not limited to, etching, deposition, and cleaning processes. Substrate processing systems (also called tools) may comprise multiple processing chambers (also called process modules). Some processing chambers in a tool may perform the same process on different substrates. In some tools, different processes may be performed in different processing chambers. For example, different processes may be performed sequentially on the same substrate by moving the substrate from one processing chamber to another. During processing, a substrate is arranged on a substrate support such as a pedestal or an electrostatic chuck (ESC) in a processing chamber of a tool. A gas delivery system supplies a gas mixture to the processing chamber to treat the substrate. Plasma may be struck to enhance chemical reactions in the processing chamber.SUMMARY

[0005] A substrate support for supporting a substrate comprises a baseplate and a coolant channel arranged in the baseplate. The coolant channel comprises a plurality of turns distributed between an outer diameter of the substrate support to a center of the substrate support, and an inlet for a coolant connected to an outermost turn of the plurality of turns. The inlet is tilted relative to an axis perpendicular to a plane in which the coolant channel lies in the substrate support.

[0006] In additional features, the inlet is tilted towards the outermost turn at an acute angle relative to the axis perpendicular to the plane in which the coolant channel lies in the substrate support.

[0007] In additional features, the plurality of turns comprise inner turns and outer turns. The outer turns including the outermost turn are semi-circular and change turning direction proximate to the inlet. The inner turns are spiral and extend to the center of the substrate support.

[0008] In additional features, the outermost turn changes turning direction proximate to the inlet. A portion of the outermost turn where the outermost turn changes turning direction is radially wider than a remainder of the outermost turn.

[0009] In additional features, the plurality of turns comprise inner turns and outer turns. The outer turns including the outermost turn are semi-circular and change turning direction proximate to the inlet. Portions of the outer turns where the outer turns change turning direction are radially wider than a remainder of the outer turns.

[0010] In additional features, the plurality of turns comprise additional curved portions that curve around fitments in the substrate support.

[0011] In additional features, the outermost turn further comprises an inlet portion, a tapered portion, and a rounded portion. The inlet portion extends from the inlet. The inlet portion is tilted towards the outermost turn at an acute angle relative to the axis perpendicular to the plane in which the coolant channel lies in the substrate support. The tapered portion extends from the inlet portion. The tapered portion comprises a tapered top portion sloping upwards. The rounded portion extends from the tapered portion. The rounded portion comprises a rounded top portion.

[0012] In additional features, top portions of the inlet portion and the tapered portion are rounded.

[0013] In additional features, the outermost turn further comprises a transition portion that extends from the rounded portion and that transitions a shape of the outermost turn from the rounded top portion of the rounded portion to a flat top portion in a remainder of the outermost turn.

[0014] In additional features, at least some turns of the plurality of turns are spaced from each other by the same distance.

[0015] In additional features, a first set of turns of the plurality of turns are spaced from each other by a first distance, and at least one turn of the plurality of turns is spaced from one turn in the first set of the turns by a second distance.

[0016] In additional features, at least some turns of the plurality of turns are spaced from a top surface of the substrate support by the same distance.

[0017] In additional features, a first set of turns of the plurality of turns are spaced from a top surface of the substrate support by a first distance, and at least one turn of the plurality of turns is spaced from the top surface of the substrate support by a second distance.

[0018] In additional features, the substrate support further comprises a plurality of voids between the coolant channel and a top surface of the substrate support.

[0019] In additional features, the plurality of voids is distributed between a first radial distance from the center of the substrate support and a second radial distance from the center of the substrate support.

[0020] In additional features, at least some voids of the plurality of voids extend radially between a first radial distance from the center of the substrate support and a second radial distance from the center of the substrate support.

[0021] In additional features, at least some voids of the plurality of voids are discontinuous around fitments in the substrate support.

[0022] In additional features, at least some voids of the plurality of voids are spaced from each other by the same distance.

[0023] In additional features, a first set of voids of the plurality of voids are spaced from each other by a first distance, and at least one void of the plurality of voids is spaced from one void in the first set of the voids by a second distance.

[0024] In additional features, at least some voids of the plurality of voids are spaced from the top surface of the substrate support by the same distance.

[0025] In additional features, a first set of voids of the plurality of voids are spaced from the top surface of the substrate support by a first distance, and at least one void of the plurality of voids is spaced from the top surface of the substrate support by a second distance.

[0026] In additional features, the plurality of turns comprises an inner most turn having an outlet for the coolant.

[0027] In still other features, a substrate support for supporting a substrate comprises a baseplate, a coolant channel arranged in the baseplate, and a feeding assembly. The coolant channel comprises a plurality of turns distributed between an outer diameter of the substrate support to a center of the substrate support. The feeding assembly is connected to an inner edge of an outermost turn of the plurality of turns to feed a coolant to the outermost turn of the coolant channel.

[0028] In additional features, the feeding assembly comprises an inlet portion and a radial transition portion. The inlet portion is parallel to a plane in which the coolant channel lies in the substrate support. The radial transition portion slopes at an acute angle relative to the plane in which the coolant channel lies in the substrate support and is connected to the inner edge of the outermost turn.

[0029] In additional features, the feeding assembly extends radially outwards and slopes upwards from under the coolant channel towards the outermost turn and is connected laterally to the inner edge of the outermost turn.

[0030] In additional features, the plurality of turns spiral from the outer diameter of the substrate support to the center of the substrate support. The plurality of turns comprise additional curved portions that curve around fitments in the substrate support.

[0031] In additional features, the outermost turn comprises an inlet portion connected to the feeding assembly. A top of the inlet portion is rounded and sloping upwards at a first acute angle relative to a plane in which the coolant channel lies in the substrate support in a direction in which the outermost turn extends.

[0032] In additional features, the outermost turn further comprises a rounded portion and a transition portion. The rounded portion extends from the inlet portion. The rounded portion comprises a rounded top portion. The transition portion extend from the roundedportion. The transition portion transitions a shape of the outermost turn from the rounded top portion of the rounded portion to a flat top portion in a remainder of the outermost turn.

[0033] In additional features, the outermost turn further comprises a portion that extends from the transition portion up to an end of the outermost turn. The portion comprises a fin that extends downwards into the outermost turn.

[0034] In additional features, a depth of the fin in the portion changes from the transition portion up to the end of the outermost turn.

[0035] In additional features, at least some turns of the plurality of turns are spaced from each other by the same distance.

[0036] In additional features, a first set of turns of the plurality of turns are spaced from each other by a first distance, and at least one turn of the plurality of turns is spaced from one turn in the first set of the turns by a second distance.

[0037] In additional features, at least some turns of the plurality of turns are spaced from a top surface of the substrate support by the same distance.

[0038] In additional features, a first set of turns of the plurality of turns are spaced from a top surface of the substrate support by a first distance, and at least one turn of the plurality of turns is spaced from the top surface of the substrate support by a second distance.

[0039] In additional features, the substrate support further comprises a plurality of voids between the coolant channel and a top surface of the substrate support.

[0040] In additional features, the plurality of voids is distributed between a first radial distance from the center of the substrate support and a second radial distance from the center of the substrate support.

[0041] In additional features, at least some voids of the plurality of voids extend radially between a first radial distance from the center of the substrate support and a second radial distance from the center of the substrate support.

[0042] In additional features, at least some voids of the plurality of voids are discontinuous around fitments in the substrate support.

[0043] In additional features, at least some voids of the plurality of voids are spaced from each other by the same distance.

[0044] In additional features, a first set of voids of the plurality of voids are spaced from each other by a first distance, and at least one void of the plurality of voids is spaced from one void in the first set of the voids by a second distance.

[0045] In additional features, at least some voids of the plurality of voids are spaced from the top surface of the substrate support by the same distance.

[0046] In additional features, a first set of voids of the plurality of voids are spaced from the top surface of the substrate support by a first distance, and at least one void of the plurality of voids is spaced from the top surface of the substrate support by a second distance.

[0047] In additional features, the plurality of turns comprises an inner most turn having an outlet for the coolant.

[0048] In still other features, a substrate support for supporting a substrate comprises a baseplate, a coolant channel arranged in the baseplate, and a plenum. The coolant channel comprises a plurality of turns distributed between an outer diameter of the substrate support to a center of the substrate support. The plenum is connected to an outermost turn of the plurality of turns to supply a coolant to the outermost turn of the coolant channel.

[0049] In additional features, the plenum is annular and is connected to the outermost turn by a plurality of connecting tubes distributed circumferentially between the plenum and the outermost turn.

[0050] In additional features, the substrate support further comprises a feeding assembly connected to an inner edge of the plenum.

[0051] In additional features, the feeding assembly extends radially outwards from under the coolant channel towards the inner edge of the plenum and is connected laterally to the inner edge of the plenum.

[0052] In additional features, the plurality of turns spiral from the outer diameter of the substrate support to the center of the substrate support. The plurality of turns comprise additional curved portions that curve around fitments in the substrate support.

[0053] In additional features, at least some turns of the plurality of turns are spaced from each other by the same distance.

[0054] In additional features, a first set of turns of the plurality of turns are spaced from each other by a first distance, and at least one turn of the plurality of turns is spaced from one turn in the first set of the turns by a second distance.

[0055] In additional features, at least some turns of the plurality of turns are spaced from a top surface of the substrate support by the same distance.

[0056] In additional features, a first set of turns of the plurality of turns are spaced from a top surface of the substrate support by a first distance, and at least one turn of the plurality of turns is spaced from the top surface of the substrate support by a second distance.

[0057] In additional features, the substrate support further comprises a plurality of voids between the coolant channel and a top surface of the substrate support.

[0058] In additional features, the plurality of voids is distributed between a first radial distance from the center of the substrate support and a second radial distance from the center of the substrate support.

[0059] In additional features, at least some voids of the plurality of voids extend radially between a first radial distance from the center of the substrate support and a second radial distance from the center of the substrate support.

[0060] In additional features, at least some voids of the plurality of voids are discontinuous around fitments in the substrate support.

[0061] In additional features, at least some voids of the plurality of voids are spaced from each other by the same distance.

[0062] In additional features, a first set of voids of the plurality of voids are spaced from each other by a first distance, and at least one void of the plurality of voids is spaced from one void in the first set of the voids by a second distance.

[0063] In additional features, at least some voids of the plurality of voids are spaced from the top surface of the substrate support by the same distance.

[0064] In additional features, a first set of voids of the plurality of voids are spaced from the top surface of the substrate support by a first distance, and at least one void of the plurality of voids is spaced from the top surface of the substrate support by a second distance.

[0065] In additional features, the plurality of turns comprises an inner most turn having an outlet for the coolant.

[0066] Further areas of applicability of the present disclosure will become apparent from the detailed description, the claims and the drawings. The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the disclosure.BRIEF DESCRIPTION OF THE DRAWINGS

[0067] The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:

[0068] FIG. 1 shows a first example of a substrate processing system comprising a processing chamber that includes a substrate support comprising a coolant channel according to the present disclosure;

[0069] FIG. 2 shows a second example of a substrate processing system comprising a processing chamber that includes a substrate support comprising a coolant channel according to the present disclosure;

[0070] FIG. 3 schematically shows a substrate support comprising a coolant channel according to the present disclosure;

[0071] FIGS. 4 and 5 show a perspective view of a first design of a coolant channel according to the present disclosure that can be used in the substrate supports of FIGS. 1 -3;

[0072] FIG. 6 shows a partial cross-sectional view of a substrate support comprising the coolant channel of FIGS. 4 and 5;

[0073] FIG. 7 shows a perspective view of a second design of a coolant channel according to the present disclosure that can be used in the substrate supports of FIGS. 1 -3;

[0074] FIG. 8 shows a side view of the coolant channel of FIG. 7;

[0075] FIG. 9 shows additional features of the coolant channel of FIG. 7;

[0076] FIG. 10 shows a top view of the coolant channel of FIG. 7;

[0077] FIG. 11 shows an example of a feeding assembly that is embedded in the substrate support for feeding coolant into the coolant channel of FIG. 7;

[0078] FIG. 12 shows a partial cross-sectional view of a substrate support comprising the coolant channel of FIG. 7 and the feeding assembly of FIG. 11 ;

[0079] FIG. 13 shows a perspective view of a third design of a coolant channel according to the present disclosure that can be used in the substrate supports of FIGS. 1 -3;

[0080] FIG. 14 shows an expanded partial perspective view of the coolant channel of FIG. 13 showing a plenum for feeding the coolant channel of FIG. 13;

[0081] FIG. 15 shows a top view of the plenum of the coolant channel of FIGS. 13 and 14;

[0082] FIG. 16 shows a bottom view of the plenum of the coolant channel of FIGS. 13 and 14;

[0083] FIG. 17 shows a partial cross-sectional view of a substrate support comprising the coolant channel of FIGS. 13 and 14;

[0084] FIG. 18 shows a top view of a design of a substrate support, which comprises voids according to the present disclosure and any coolant channel of FIGS. 4-17, and which can be used in processing chambers of FIGS. 1 and 2;

[0085] FIGS. 19 and 20 show partial cross-sectional views of the substrate support of FIG. 18; and

[0086] FIG. 21 and 22 show additional features of the coolant channels shown in FIGS. 4-17.

[0087] In the drawings, reference numbers may be reused to identify similar and / or identical elements.DETAILED DESCRIPTION

[0088] Some processing chambers use an electrostatic chuck (ESC) to support a substrate during processing. The ESC comprises one or more clamping electrodes that electrostatically clamp the substrate to the ESC during processing. ESCs comprise one or more heaters to heat the substrate. The substrate and the ESC also receive heat from plasma when plasma is used during substrate processing. ESCs comprise one or more cooling mechanisms to draw heat from the ESC and to maintain temperature uniformity across the substrate during processing. For example, the ESC can comprise gas channels through which a gas (e.g., an inert gas such as helium) is supplied to cool the substrate. Alternatively or additionally, the ESC can comprise coolant channels throughwhich a coolant is circulated to draw heat from the ESC and the substrate during processing.

[0089] Current design of the coolant channels is optimized to fit as much coolant pathway into the ESC as possible to ensure more heat rejection. The coolant channel is also designed to accommodate fitments of various other features of the ESC. For example, the coolant channel is generally circular or spiral in shape and is routed around various local features of the ESC. For example, the local features include temperature sensors, power supply lines for the heaters, gas channels, through holes for lift pins, and so on that are routed through and within the ESC. Accordingly, the coolant channel enters into the ESC and immediately turns and then winds (spirals) around other features in the ESC to avoid the other features.

[0090] The current design of the coolant channels has various problems. For example, the coolant channels have tighter radii and abrupt turns to avoid the local features. The coolant channels have right angled turns to enter and exit the ESC. The constraints on the design of the coolant channels such as tighter radii and abrupt turns to avoid the local features, right angled turns at entry and exit points, and so on tend to cause cold spots on the substrate. Cold spots are localized or isolated areas or regions on the substrate that are colder than the rest of the substrate. That is, the temperatures in the cold spots differ from and are less than the temperature of the rest of the substrate. The difference in these temperatures can be more pronounced at some processing temperatures than others. Thus, the cold spots cause temperature nonuniformities across the substrate, which can cause process defects. The cross-section of the coolant channel is the same throughout the coolant channel, and the coolant channel is located at the same distance from the substrate. The coolant channels do not include any additional features to address the cold spots.

[0091] Specifically, the coolant channels in the ESCs have increasing complexity to account for requirements for a more uniform temperature on the substrate. Since the ESC is the sink for heat flowing into the substrate, any cooling provided by the ESC greatly impacts the temperature uniformity of the substrate. A low temperature coolant flows through the coolant channel to reject the heat that comes from the plasma and goes through the substrate and the ESC. The flow and geometry of the coolant channel can cause temperature nonuniformity due to characteristics of the coolant flow through the coolant channel geometry. For example, tight turns in the coolant channel cause a thinnerflow boundary layer immediately in the vicinity of the turn. The thinner flow boundary layer causes increased thermal conduction in the area, which causes a cold spot on the substrate since there is increased heat rejection locally near that turn in the coolant channel.

[0092] The present disclosure provides designs for the coolant channels that overcome temperature non-uniformities due to the above problems with the coolant channel design. The designs provided in the present disclosure solve these problems and overcome temperature non-uniformities by 1 ) ensuring consistent coolant flow characteristics in the coolant channel, 2) insulating areas where geometric constraints create flow nonuniformities, and 3) feeding the coolant channel in a manner that the geometry of the coolant channel can tune out local temperature non-uniformities as described below in detail. Additionally, the local features of the ESC such as temperature sensors, power supply lines for the heaters, gas channels, through holes for lift pins, and so on are spaced (relocated) to avoid additive effect of having the jogs (routing) of the coolant channel around the local features being too close together.

[0093] Since any coolant has varying properties at different temperatures (e.g., viscosity, density, thermal conductivity, etc.), a coolant can respond to a particular geometry of the coolant channel differently depending on temperature of the coolant in a particular condition in the coolant channel. The local temperature response for a given geometry of the coolant channel is therefore sensitive to temperature dependent properties of the coolant. Specifically, viscosity has a major effect on cooling of a local geometry of the coolant channel.

[0094] The present disclosure provides a coolant channel whose geometric design removes or minimizes local cooling dependencies on temperature dependent properties of a coolant, specifically viscosity. The coolant channel is shaped to minimize change in momentum of the fluid (i.e., coolant) inside the coolant channel that can otherwise cause local cooling to vary from point to point. In broad terms, radii of the coolant channel are maximized, and local widening of the coolant channel is provided to limit flow velocity of the coolant in the coolant channel and therefore limit the effect of variation in the local boundary layer. Areas of the coolant channel with higher sensitivity to flow characteristics of the coolant are insulated by positioning these portions of the coolant channel further away from the substrate so that areas of the coolant channel that do have consistent heatrejection characteristics over a wider temperature range can have a dominant effect over those that are inconsistent.

[0095] Additionally, areas of the coolant channel that are systematically cooler over a wide range of coolant temperatures are spaced out to ensure that heat rejection in those areas is uniform to the rest of the ESC area. In other words, the design of the coolant channel is optimized (tuned) to avoid cold spots and hot spots over a given temperature range while considering changes in thermal properties such as viscosity of the coolant over the temperature range. Hot spots are localized or isolated areas or regions on the substrate that are hotter than the rest of the substrate. That is, the temperatures in the hot spots differ from and are greater than the temperature of the rest of the substrate. Thus, the hot spots also --cause temperature nonuniformities across the substrate, which can cause process defects.

[0096] Another feature provided in the present disclosure is a coolant channel design where the coolant channel is fed by an annulus-shaped plenum instead of being fed through a single inlet. A coolant from the annulus-shaped plenum is fed through a plurality of feeding elements into the coolant channel. The feeding elements between the annulusshaped plenum and the coolant channel are small relative to the size of the annulus such that each feeding element has similar pressure / flow from the annulus-shaped plenum into the coolant channel. By adding, removing, and adjusting spacing between individual feeding elements, azimuthal uniformity from the annular plenum to the coolant channel can be tuned to remove hot or cold spots.

[0097] Yet another feature provided in the present disclosure is a coolant channel design in which an insert is used to locally insulate the coolant channel to reduce cooling in the area. Without the insert, a cold spot can be caused by a sudden or abrupt change of coolant momentum (e.g., where the coolant enters the ESC from below and has to change direction to flow in the plane of the ESC). To further add insulation, a series of inserts can be inserted vertically and then put in position laterally to insulate areas adjacent to the coolant inlet as well as immediately at the insert. Another feature is shallowing out any abrupt changes in momentum where the spiral coolant channel meets the radial feed to the spiral coolant channel. The shallowing out feature is the maximizing of the angle of the abrupt change (e.g., using an obtuse angle such as 125° instead of 90° as the coolant enters the ESC).

[0098] Still another feature provided in the present disclosure is a coolant channel design in which voids are created above a coolant channel (i.e., between the coolant channel and a top surface of the ESC on which the substrate is arranged) such that the voids act as thermal insulators. For example, in the ESC manufacturing process that uses a layered construction of the ESC, a void can be constructed as an opening between two successive layers of the ESC brazement. The void can be constructed by machining the face of one layer before brazing the two layers together, and then not using that opening between the brazed layers for any other function.

[0099] The coolant channel designs of the present disclosure allow for greater temperature uniformity on the substrate by ensuring an even heat rejection over a wider array of temperature conditions. The different temperature conditions equate to different coolant properties / viscosities that vary based on chiller setpoint and plasma power input into the processing chamber. These and other features of the present disclosure are described below in detail.

[0100] The present disclosure is organized as follows. Examples of substrate processing systems comprising processing chambers that include a substrate support that can utilize any coolant channel of the present disclosure are shown and described with reference to FIGS. 1 and 2. FIG. 3 schematically shows a substrate support in which any coolant channel of the present disclosure can be used. A first design of a coolant channel according to the present disclosure is shown and described with reference to FIGS. 4-6. A second design of a coolant channel according to the present disclosure is shown and described with reference to FIGS. 7-12. A third design of a coolant channel according to the present disclosure is shown and described with reference to FIGS. 13- 17. A design of a substrate support that comprises voids according to the present disclosure and that can comprise any coolant channel design of the present disclosure is shown and described with reference to FIGS. 18-20. Additional design features of the coolant channels are shown and described with reference to FIGS. 21 and 22.EXAMPLES OF SUBSTRATE PROCESSING SYSTEMS

[0101] FIG. 1 shows a first example of a substrate processing system 10 comprising a processing chamber 28, which includes a substrate support 30 that can utilize a coolant channel according to the present disclosure. In FIG. 1 , the coolant channel is only generally shown at 38. Various coolant channel designs of the present disclosure are shown and described with reference to subsequent figures. Any of these coolant channeldesigns can be used in the substrate support 30 instead of the coolant channel 38 shown in FIG. 1.

[0102] The substrate processing system 10 uses inductively coupled plasma to etch substrates. While the substrate processing system 10 comprising only one processing chamber is shown, the substrate processing system 10 may comprise additional processing chambers. The additional processing chambers may perform deposition processes on substrates. The additional processing chambers may also comprise a chamber that performs metrological measurements of the substrates processed in these processing chambers. While the example shows a processing chamber for an etch process, the coolant channel designs of the present disclosure can also be used in a processing chamber in which a deposition process is performed.

[0103] The substrate processing system 10 includes a coil driving circuit 11. The coil driving circuit 11 includes a radio frequency (RF) source 12, a pulsing circuit 14, and a tuning circuit (i.e., matching circuit) 13. The RF source 12 generates an RF signal. The pulsing circuit 14 controls a transformer coupled plasma (TCP) envelope of the RF signal and varies a duty cycle of TCP envelope (e.g., between 1 % and 99%) during operation. The pulsing circuit 14 and the RF source 12 can be combined or separate. The tuning circuit 13 may be directly connected to an inductive coil 16. While a single coil is shown for example, the substrate processing system 10 may use a plurality of coils (e.g., inner and outer coils). The tuning circuit 13 tunes an output of the RF source 12 to a desired frequency and / or a desired phase, and matches an impedance of the inductive coil 16.

[0104] A dielectric window 24 is arranged along a top end of the processing chamber 28. The processing chamber 28 comprises the substrate support (or pedestal) 30 to support a substrate 34. The substrate support 30 may include an electrostatic chuck (ESC), a substrate support that uses vacuum clamping, mechanical clamping, or other type of substrate support. The substrate support 30 comprises a baseplate 32 and a ceramic plate 33. The baseplate 32 is made of a metallic material (e.g., aluminum or an alloy). The ceramic plate 33 is arranged on a top surface of the baseplate 32. A thermal resistance layer 36 made of an electrically and thermally insulating material is disposed between the ceramic plate 33 and the baseplate 32. The substrate 34 is arranged on the ceramic plate 33 during processing.

[0105] The ceramic plate 33 comprises an electrode 31 to electrostatically clamp the substrate 34 to the substrate support 30 during processing. While not shown, one or moreheaters may also be arranged in the ceramic plate 33 to heat the substrate 34 during processing. The baseplate 32 comprises the coolant channel 38 to cool the substrate support 30. The coolant channel 38 uses a fluid supplied by a fluid delivery system 39 to cool the substrate support 30. In addition, the fluid delivery system 39 can supply the fluid to manifolds (not shown) arranged on the dielectric window 24 to cool portions of the dielectric window 24.

[0106] A gas delivery system 56 is used to supply a process gas mixture to the processing chamber 28. The gas delivery system 56 may include process and inert gas sources 57, a gas metering system 58 including valves and mass flow controllers (MFCs), and a manifold 59. A gas injector 63 may be arranged at a center of the dielectric window 24 and is used to inject gas mixtures from the gas delivery system 56 into the processing chamber 28. Additionally or alternatively, the gas mixtures may be injected from the side of the processing chamber 28.

[0107] When a process gas is supplied to the processing chamber 28, a plasma 40 is generated inside of the processing chamber 28 by supplying RF power from the coil driving circuit 11 to the inductive coil 16. The plasma 40 etches an exposed surface of the substrate 34. An RF source 50, a pulsing circuit 51 , and a bias matching circuit 52 may be used to bias the substrate support 30 during processing to control ion energy.

[0108] The substrate support 30 and the dielectric window 24 include temperature sensors 35, 25 to sense temperatures of substrate support 30 and the dielectric window 24. A temperature controller 64 communicates with the temperature sensors 35, 25. Based on the temperatures of substrate support 30 and the dielectric window 24 sensed by the temperature sensors 35, 25, the temperature controller 64 controls the fluid delivery system 39 to control fluid flow through the coolant channel 38 to cool the substrate support 30 and though the manifold arranged over the dielectric window 24 to cool the dielectric window 24. The temperature controller 64 also controls the heaters in the substrate support 30 to control the temperature of the substrate support 30 and the substrate 34.

[0109] An exhaust system 65 includes a valve 66 and pump 67 to control pressure in the processing chamber 28 and / or to remove reactants from the processing chamber 28 by purging or evacuation. A controller 70 (also called system controller) controls the etching process. The controller 70 controls the components of the substrate processing system 10 described above. For example, the controller 70 monitors system parametersand controls delivery of the gas mixture from the gas delivery system 56. The controller 70 controls striking, maintaining, and extinguishing the plasma 40; removal of reactants from the processing chamber 28; fluid supply from the fluid delivery system 39; and so on. Additionally, the controller 70 controls various aspects of the coil driving circuit 11 , the RF source 50, the pulsing circuit 51 , and the bias matching circuit 52, and so on.

[0110] FIG. 2 shows a second example of a substrate processing system 100 for processing substrates. The substrate processing system 100 comprises a processing chamber 102 for processing the substrates using processes such as plasma etching or deposition. The processing chamber 102 comprises a substrate support 104 and a showerhead 106. For example, the substrate support 104 comprises an electrostatic chuck (ESC) although other types of substrate supports can be used instead. A substrate 108 is arranged on the substrate support 104 during processing.

[0111] The substrate support 104 can utilize a coolant channel according to the present disclosure. In FIG. 2, the coolant channel is only generally shown at 152. Various coolant channel designs of the present disclosure are shown and described with reference to subsequent figures. Any of these coolant channel designs can be used in the substrate support 104 instead of the coolant channel 152 shown in FIG. 2.

[0112] The showerhead 106 comprises a base portion 109 and a stem portion 1 10. The base portion 109 is generally cylindrical and extends radially outwardly towards sidewalls of the processing chamber 102. The stem portion 110 is also cylindrical and is smaller in diameter than the base portion 109. One end of the stem portion 110 is attached to the center of the base portion 109. The other end of the stem portion 110 is attached to a top plate of the processing chamber 102.

[0113] The base portion 109 of the showerhead 106 comprises a plurality of through holes (not shown) on a substrate-facing side of the base portion 109. The showerhead 106 receives one or more gases from a gas delivery system 170 as described below. The gases are dispensed via the through holes in the base portion 109 into the processing chamber 102. A plasma 1 12 may be struck between the showerhead 106 and the substrate 108 during substrate processing as explained below.

[0114] The substrate support 104 comprises a ceramic plate 103 disposed on a metallic baseplate 105. The ceramic plate 103 comprises an electrode 118 to electrostatically clamp the substrate 108 to the substrate support 104 during substrate processing. A top edge ring (TER) 120 is arranged on the substrate support 104 along a periphery of thesubstrate support 104. The TER 120 surrounds the substrate 108 as shown. The TER 120 is also electrostatically clamped to the ceramic plate 103 of the substrate support 104 during substrate processing.

[0115] A tuning edge sheath (TES) ring 122 is arranged under and adjacent to the TER 120 in the ceramic plate 103 of the substrate support 104. The TES ring 122 comprises an electrode 124 that supplies RF power to the TER 120. The RF power is used to adjust the shape of the plasma 112 near the edge of the substrate 108. The RF power can be adjusted to control etch uniformity on the substrate 108. A plurality of additional edge rings 126, 128 is arranged at the periphery of the substrate support 104.

[0116] An actuator assembly 130 is used to actuate the TES ring 122. While only one actuator assembly 130 is shown, at least three actuator assemblies 130 are used to actuate the TES ring 122. For example, the three actuator assemblies 130 are spaced 120 degrees apart from each other around the substrate support 104 and are used to actuate the TES ring 122.

[0117] The actuator assembly 130 comprises an actuator 132 and a rod 136. The actuator 132 is mounted to the bottom of the substrate support 104 (i.e., to the bottom of the processing chamber 102). One end of the rod 136 is coupled to the actuator 132. A distal end of the rod 136 passes through the substrate support 104 and is inserted and fixed into the TES ring 122. The actuator 132 moves the rod 136 up and down to move the TES ring 122 up and down relative to the TER 120. During substrate processing, the electrode 124 in the TES ring 122 provides RF power to the TER 120 to adjust the shape of the plasma 112 near the edge of the substrate 108. The RF power can be adjusted to control etch uniformity on the substrate 108.

[0118] A temperature sensing assembly 140 is used to measure the temperature of the TES ring 122. While only one temperature sensing assembly 140 is shown, at least three temperature sensing assemblies 140 are arranged around the substrate support 104 and are used to measure the temperature of the TES ring 122. For example, the three temperature sensing assemblies 140 are spaced 120 degrees apart from each other and are radially offset from the three actuator assemblies 130.

[0119] The temperature sensing assembly 140 comprises a temperature probe 142 and a temperature sensor 143. The temperature sensor 143 is mounted on (i.e., attached to) one end of the temperature probe 142 to sense the temperature of the TES ring 122. The temperature sensing assembly 140 further comprises bellows 144 mounted to the bottomof the substrate support 104 (i.e., to the bottom of the processing chamber 102). A distal end of the temperature probe 142 passes through the substrate support 104 and the bellows 144. When the TES ring 122 is moved up and down, the temperature probe 142 also moves up and down freely through the bellows 144. Thus, the temperature of the TER 120 can be accurately sensed.

[0120] The baseplate 105 comprises the coolant channel 152. A coolant supply 160 circulates a coolant through the coolant channel 152 to control the temperature of the substrate support 104 and the substrate 108 during substrate processing. While not shown, a heater may be arranged under the electrode 118 in the ceramic plate 103 of the substrate support 104. The heater heats the substrate 108 during processing.

[0121] A temperature controller 162 receives the temperature of the substrate support 104 from temperature sensors (not shown) disposed in the substrate support 104. The temperature controller 162 also receives the temperature of the TER 120 from the temperature sensors 144 of the temperature sensing assemblies 140. Based on the temperatures of the substrate support 104 and the TER 120, the temperature controller 162 controls the heater and the supply of the coolant from the coolant supply 160 through the coolant channels 152.

[0122] The substrate processing system 100 further comprises the gas delivery system 170 to supply various gases (e.g., process gases, purge gases, cleaning gases, etc.) to the processing chamber 102. The gas delivery system 170 comprises gas sources 172, valves 174, and mass flow controllers (MFCs) 176. The gas sources 172 supply the various gases through the valves 174 to the MFCs 176. The MFCs 176 control the flow rates of the gases. The MFCs 176 supply the gases at the controlled flow rates to a mixing manifold 182.

[0123] In addition, the gas delivery system 170 comprises a vapor delivery system 178 to deliver one or more vaporized precursors used in some processes. The vapor delivery system 178 delivers the vaporized precursors through valves 180 to the mixing manifold 182. The gases (or gas mixtures) from the mixing manifold 182 are delivered to the showerhead 106 via a valve system 184 attached to the showerhead 106.

[0124] The substrate processing system 100 further comprises a RF power supply 186 that supplies RF power to the showerhead 106 to generate the plasma 112 during substrate processing. The RF power supply 186 comprises an RF generator 188 and a matching circuit 190. The RF generator 188 generates the RF power. The matchingcircuit 190 performs impedance matching and outputs the RF power to the showerhead 106. When the process gases are supplied to the showerhead 106, the RF power supply 186 supplies the RF power to the showerhead 106 to generate the plasma 112.

[0125] The substrate processing system 100 further comprises a vacuum pump 192 that is connected to the processing chamber 102 via a valve 194. The vacuum pump 192 maintains vacuum in the processing chamber 102. The vacuum pump 192 also evacuates reactants from the processing chamber 102. The substrate processing system 100 further comprises a controller 196. The controller 196 controls the operations of the components of the substrate processing system 100 described above.SUBSTRATE SUPPORT WITH COOLANT CHANNEL

[0126] FIG. 3 schematically shows a substrate support 200 in which any coolant channel design described below with reference to FIG. 4 onwards can be used. The substrate support 200 can be used in the substrate processing systems 10 and 100 described above with reference to FIGS. 1 and 2. Some elements of the substrate supports 30 and 104 shown in FIGS. 1 and 2 are omitted in the substrate support 200 shown in FIG. 3. However, the omitted elements such as temperature sensors, power supply lines for electrodes and heaters, and other hardware (e.g., elements used to lift and lower features described above with reference to FIGS. 1 and 2) are presumed present in the substrate support 200 shown in FIG. 3.

[0127] The substrate support 200 comprises a baseplate 202 and a ceramic plate 204 disposed on the baseplate 202. The baseplate 202 is made of a metallic material (e.g., aluminum or an alloy). The baseplate 202 comprises a coolant channel 206. An outer diameter (OD) of the coolant channel 206 is less than an OD of the substrate support 200. Various coolant channel designs are shown and described below with reference to FIGS. 4-22. The coolant channel 206 can include any of the coolant channel designs shown and described below with reference to FIGS. 4-22. Additionally, the substrate support 200 can comprise voids shown and described below with reference to FIGS. 18- 20. A substrate 208 is arranged on the ceramic plate 204 during processing.FIRST DESIGN OF COOLANT CHANNEL

[0128] A first design of a coolant channel 300 according to the present disclosure is shown and described with reference to FIGS. 4-6. The coolant channel 300 can be used in the substrate support 200 of FIG. 3, which can be used in the processing chambers ofFIGS. 1 and 2. FIGS. 4 and 5 show a perspective view of coolant channel 300 that can be used in the substrate supports of FIGS. 1 -3. FIG. 6 shows a partial cross-sectional view of the substrate support 200 comprising the coolant channel 300 of FIGS. 4 and 5.

[0129] FIG. 4 shows the coolant channel 300 as a separate structure only to illustrate various features of the coolant channel 300. Practically, the coolant channel 300 is formed in the baseplate 202 of the substrate support 200 as shown in FIG. 5 during the manufacture of the substrate support 200. Accordingly, FIG. 5 shows a portion of the baseplate 202 of the substrate support 200 with the coolant channel 300 formed therein. FIG. 6 shows a partial cross-sectional view of a substrate support comprising the coolant channel of FIGS. 4 and 5.

[0130] The coolant channel 300 comprises a plurality of turns. The plurality of turns comprise a first plurality of outer turns and a second plurality of inner turns. The outer and inner tunes are connected to each other and form the single and continuous coolant channel 300. An outermost turn 255 of the coolant channel 300 comprises an inlet 253. An innermost turn 258 of the coolant channel 300 comprises an outlet 256. A coolant is supplied to the coolant channel 300 through the inlet 253. The coolant flows through the plurality of turns of the coolant channel 300 distributed between the outermost turn 255 and the innermost turn 258. The coolant flows out of the coolant channel 300 through the outlet 256.

[0131] The outer turns of the coolant channel 300 comprise the outermost turn 255 and turns 254-1 , 254-2, 254-3. The remaining turns of the coolant channel 300 are the inner turns. The outer turns 255, 254-1 , 254-2, 254-3 are nearly but not fully circular nor spiral. The outer turns 255, 254-1 , 254-2, 254-3 are semi-circular. The inner turns of the coolant channel 300 spiral radially inwards from an innermost of the outer turns up to the innermost turn 258. The outermost turn 255 comprises an inlet portion 261 connected to the inlet 253 and a tapered portion 283 that extends from the inlet portion 261 . The inlet portion 261 is located between and is connected to the inlet 253 and the tapered portion 283. Accordingly, the outer turns 255, 254-1 , 254-2, 254-3 of the coolant channel 300 turn around the inlet portion 261 and turn in an opposite direction until the inner turns begin to spiral radially inwards.

[0132] The outer turns 255, 254-1 , 254-2, 254-3 of the coolant channel 300 comprise turn-around portions shown at 263, 265, and 267 that turn around in the opposite direction from near the inlet portion 261 . The turn-around portions 263, 265, and 267 areadjacent to but spaced apart from the inlet portion 261 of the coolant channel 300. The turn-around portions 263, 265, and 267 provide advantages described below. After the last turn-around portion 267, the inner turns of the coolant channel 300 are not intercepted by the inlet portion 261 and therefore spiral radially inwards up to the innermost turn 258.

[0133] To understand the improvements in the design of the coolant channel 300 and the advantages provided by the coolant channel 300, the design and drawbacks of a typical coolant channel are briefly described. As used herein, the typical coolant channel is not any of the coolant channels shown and described with reference to FIGS. 4-22. Instead, the typical coolant channel is any of the most commonly used coolant channels (e.g., existing designs of coolant channels).

[0134] In general, the turns of a typical coolant channel have of a fixed radial width and a fixed height (depth). The turn-around portions also have the same width and height as the width and height of the turns of the typical coolant channel. Accordingly, the crosssection of the typical coolant channel is the same throughout the coolant channel. The typical coolant channel is also disposed in a substrate support at the same distance (depth) from the substrate.

[0135] Further, the design of the typical coolant channel is optimized to fit as much coolant pathway into the substrate support as possible to ensure more heat rejection. The typical coolant channel is also designed to accommodate fitments of various other features of the substrate support. For example, the typical coolant channel is generally circular or spiral in shape and is routed around various features (fitments of various other features) of the substrate support. For example, the features include temperature sensors, power supply lines for the heaters, gas channels, through holes for lift pins, and so on that are routed through and within the substrate support. The turns of the typical coolant channel include portions (called jogs or hops) that are routed around the features embedded in the substrate support. The jogs are sharp turns in portions of the turns of the typical coolant channel that are designed to avoid the features embedded in the substrate support.

[0136] The above design of the typical coolant channel has various problems. For example, the typical coolant channel comprises turns having tighter radii and abrupt (sharp) turns to avoid the local features. The typical coolant channel has right angled turns at the inlet and the outlet of the coolant channel. The constraints on the design ofthe typical coolant channel such as tighter radii and abrupt turns to avoid the local features of the substrate support, right angled turns at the inlet and the outlet, and so on tend to cause cold spots on the substrate. Additionally, the turn-around portions, which are located close to the inlet portion of the typical coolant channel, also tend to cause cold spots on the substrate. As described above, the cold spots cause temperature nonuniformities across the substrate, which can cause process defects. The typical coolant channel does not include any additional features to address the cold spots.

[0137] In modern processes, the coolant channels have increasing complexity to account for requirements for a more uniform temperature on the substrate. Since the substrate support is the sink for heat flowing into the substrate, any cooling provided by the coolant channels in the substrate support greatly impacts the temperature uniformity of the substrate. A low temperature coolant flows through the coolant channels to reject the heat that comes from the plasma and goes through the substrate and the substrate support. The flow and geometry of the typical coolant channel can cause temperature nonuniformity due to characteristics of the coolant flow through the typical coolant channel geometry as described above. For example, in the existing design of the typical coolant channel, the tight turns in the typical coolant channel cause a thinner flow boundary layer immediately in the vicinity of the turn. The thinner flow boundary layer causes increased thermal conduction in the area, which causes a cold spot on the substrate since there is increased heat rejection locally near that turn in the coolant channel. The following design of the coolant channel 300 of the present disclosure solves the above problems.

[0138] The design of the coolant channel 300 differs from the design of the typical coolant channel in many aspects, which eliminate or minimize the problems of cold spots and temperature nonuniformities described above. The differences between the coolant channel 300 and the typical coolant channel are described below. The advantages provided by the features of the coolant channel 300 (e.g., how the features of the coolant channel 300 achieve temperature uniformity) are described after describing the features of the coolant channel 300.

[0139] In FIGS. 4 and 5, the turns of the coolant channel 300 comprises jogs 271 around local features 273 of the substrate support 200. The jogs 271 are smoother than the sharply angled jogs in the turns of the typical coolant channel. That is, the jogs 271 in the turns of the coolant channel 300 are not as sharp and angular in shape as the jogs in theturns of the typical coolant channel. Instead, the jogs 271 in the turns of the coolant channel 300 are smoothly curved (contoured). The local features 273 can also be relocated in the substrate support to facilitate smoother jogs and relatively even radial distribution of the turns of the coolant channel 300.

[0140] The turn-around portions 263, 265, and 267 of the outer turns of the coolant channel 300 are wider than the turn-around portions of the outer turns of the typical coolant channel. Specifically, the turn-around portions 263, 265, and 267 of the outer turns of the coolant channel 300 have a greater radial width and a greater cross-section than the radial width (i.e., the cross-section) of the turns of the typical coolant channel. The turn-around portions 263, 265, and 267 are also spaced apart from the inlet portion 261 of the coolant channel 300. The spacing and the width of the turn-around portions 263, 265, and 267 effectively insulate areas of the coolant channel 300 from the substrate support 200 where geometric constraints create flow nonuniformities, which minimizes or eliminates temperature nonuniformities in these areas of the substrate support 200.

[0141] The inlet of the typical coolant channel is vertical. That is, the inlet of the typical coolant channel is perpendicular to a plane in which the typical coolant channel lies in a substrate support. In contrast, the inlet 253 of the coolant channel 300 is tilted radially outwards at an acute angle relative to an axis perpendicular to a plane in which the coolant channel 300 lies in the substrate support 200 shown in FIG. 3. Accordingly, the inlet 253 of the coolant channel 300 is called the tilted inlet 253.

[0142] The inlet portion of the typical coolant channel is connected to the inlet of the typical coolant channel at right angle. Accordingly, the inlet portion of the typical coolant channel is parallel to the plane in which the typical coolant channel lies in the substrate support. In contrast, the inlet portion 261 of the coolant channel 300 is connected to the inlet 253 of the coolant channel 300 at an obtuse angle relative to the inlet 253. The inlet portion 261 of the coolant channel 300 is tilted radially outwards at an acute angle relative to the plane in which the coolant channel 300 lies in the substrate support 200 shown in FIG. 3. Accordingly, the inlet portion 261 of the coolant channel 300 is called the tilted inlet portion 261 or the slanted inlet portion 261 .

[0143] By feeding the coolant channel 300 through the tilted inlet 253 and the slanted inlet portion 261 , the coolant channel 300 can tune out local temperature nonuniformities. The tilted inlet 253, the slanted inlet portion 261 , and the spacing and the width of the turn-around portions 263, 265, and 267 insulate areas of the coolant channel300 from the substrate support 200 where geometric constraints create flow nonuniformities, which minimizes or eliminates temperature nonuniformities in these areas of the substrate support 200. The tilted inlet 253 and the slanted inlet portion 261 locally insulate the coolant channel 300 to reduce cooling in the adjacent area of the substrate support 200. Without the tilted inlet 253, the slanted inlet portion 261 , and the turn-around portions 263, 265, and 267, a cold spot can be caused by a sudden or abrupt change of coolant momentum (e.g., where the coolant enters the substrate support 200 from below and has to change direction to flow in the plane of the substrate support 200).

[0144] Further, in the typical coolant channel, the outermost turn comprises a tapered portion following the inlet portion. The tapered portion extends from the inlet portion at a sharp acute angle relative to the plane in which the typical coolant channel lies in the substrate support. In contrast, in the outermost turn 255 of the coolant channel 300, the tapered portion 283 extends from the inlet portion 261 of the coolant channel 300 at a smaller angle than in the typical coolant channel. Specifically, a top of the tapered portion 283 of the outermost turn 255 tapers and slopes upwards at a smaller angle to the plane in which the coolant channel 300 lies in the substrate support 200. The tapered portion 283 of the outermost turn 255 tapers and slopes upwards for a longer distance than the tapered portion of the outermost turn of the typical coolant channel.

[0145] Additionally, the coolant channel 300 comprises the following features that are absent in the typical coolant channel. The outermost turn 255 of the coolant channel 300 further comprises a rounded portion 285 that follows the tapered portion 283 and a transition portion 287 that follows the rounded portion 285. The transition portion 287 transitions the shape of the coolant channel 300 from a rounded top of the rounded portion 285 to a flat top in the remainder of the outermost turn 255 without changing the height (depth) of the outermost turn 255. The transition portion 287 is where edge radii of the outermost turn 255 transition into sharp corners at the top edges of the outermost turn 255. The tapered portion 283, the rounded portion 285, and the transition portion 287 of the outermost turn 255 of the coolant channel 300 can be called first, second, and third portions of outermost turn 255 of the coolant channel 300.

[0146] The rounded portion 285 extends from the tapered portion 283. The top of the rounded portion 285 is rounded. The top of the rounded portion 285 is not flat like the top of the rest of the turns of the typical coolant channel. Additionally, the top of the inlet portion 261 and the top of the tapered portion 283 are also rounded. Accordingly, the topof the outermost turn 255 is rounded from the inlet portion 261 up to the transition portion 287. As used herein, the top of the coolant channel 300 (i.e. , the tops of the turns of the coolant channel 300) is adjacent to and faces the top portion of the on the substrate support 200 and faces the substrate 208 placed on the substrate support 200 shown in FIG. 3.

[0147] Due to the design of the elements 261 , 283 described above, the height (depth) and the cross-section of outermost turn 255 of the coolant channel 300 increases gradually from the inlet 253 up to the rounded portion 285. The cross-section of outermost turn 255 decreases gradually from the end of the rounded portion 285 through the transition portion 287 until the end of the transition portion 287. Thereafter, the remainder of the outermost turn 255 and remaining turns of the coolant channel 300 have a uniform cross-section except for portions comprising the jogs 271 . For example, the cross-section of the turns of the coolant channel 300 is rectangular although the cross-section can include other polygonal shapes. The rounded portion 285 of the outermost turn 255 of the coolant channel 300 has greater height and cross-section than the rest of the coolant channel 300 as shown in FIG. 6.

[0148] The radial distance between some of the turns of the coolant channel 300 can be uniform, non-uniform, or a combination thereof as shown and described below in detail with reference to FIG. 21 . The height (depth) of some of the turns of the coolant channel 300 can be uniform, non-uniform, or a combination thereof as shown and described below in detail with reference to FIG. 22.

[0149] All of the above features of the coolant channel 300, including the tilted inlet 253, the slanted inlet portion 261 , the tapered portion 283, the rounded portion 285, the transition portion 287, the smooth jogs 271 , the wide turn-around portions 263, 265, and 267 and their spacing from the slanted inlet portion 261 improve temperature uniformity and eliminate or minimize cold and hot spots on the substrate 208 during processing. These features overcome the temperature non-uniformities caused by the typical coolant channel by ensuring consistent coolant flow characteristics in the coolant channel 300 and by feeding the coolant channel 300 in a manner that the geometry of the coolant channel 300 can tune out local temperature non-uniformities.

[0150] Additionally, the local features of the substrate support 200 such as temperature sensors, power supply lines for the heaters, gas channels, through holes for lift pins, and so on can also be spaced (relocated) to avoid additive effect of having the jogs (routing)of the coolant channel 300 around the local features being too close together. For example, the local features of the substrate support 200 can be relocated as shown at 273 in FIGS. 4 and 5. When the local features are too close together, the jogs in the turns of the coolant channel include sharp turns. By spacing the local features apart, the jogs in the turns of the coolant channel include smooth turns.

[0151] The geometric design of these features (e.g., elements 253, 261 , 263, 265, 267, 283, 285, 287) of the coolant channel 300 described above eliminates or minimizes local cooling dependencies on temperature dependent properties of the coolant, specifically viscosity. These features of the coolant channel 300 are shaped as described above to minimize change in momentum of the fluid (i.e., coolant) inside the coolant channel 300 that can otherwise cause local cooling to vary from point to point. In the design of the coolant channel 300, the radii of the turns of the coolant channel 300 are maximized, and local widening of the coolant channel 300 is provided to limit flow velocity of the coolant in the coolant channel 300 and therefore limit the effect of variation in the local boundary layer.

[0152] Areas of the coolant channel 300 (e.g., elements 253, 261 ) with higher sensitivity to flow characteristics of the coolant are insulated by positioning these portions of the coolant channel 300 further away from the substrate 208 so that areas of the coolant channel 300 that do have consistent heat rejection characteristics over a wider temperature range can have a dominant effect over those that are inconsistent. Additionally, areas of the coolant channel that are systematically cooler (e.g., elements 263, 265, 267) over a wide range of coolant temperatures are spaced out to ensure that heat rejection in those areas is uniform to the rest of the ESC area. In other words, the design of the coolant channel 300 is optimized (tuned) to avoid cold spots and hot spots over a given temperature range while considering changes in thermal properties such as viscosity of the coolant over the temperature range.SECOND DESIGN OF COOLANT CHANNEL

[0153] A second design of a coolant channel 400 according to the present disclosure is shown and described with reference to FIGS. 7-12. The coolant channel can be used in the substrate support 200 of FIG. 3, which can be used in the processing chambers of FIGS. 1 and 2. FIG. 7 shows a perspective view of the coolant channel 400 that can be used in the substrate supports of FIGS. 1 -3. FIGS. 8 and 9 show side views of the coolant channel 400 of FIG. 7. FIG. 10 shows a top view of the coolant channel 400 of FIG. 7.FIG. 11 shows an example of a feeding assembly that is embedded in the substrate support 200 for feeding coolant into the coolant channel 400 of FIG. 7. FIG. 12 shows a partial cross-sectional view of the substrate support 200 comprising the coolant channel 400 of FIG. 7 and the feeding assembly of FIG. 11 .

[0154] FIG. 7 shows a perspective view of the coolant channel 400. The coolant channel 400 is spiral and comprises a plurality of turns. The coolant channel 400 comprises an inlet 402 in an outermost turn 404. The coolant channel 400 comprises an outlet 406 in an innermost turn 408. A coolant is supplied to the coolant channel 400 through the inlet 402 by a feeding assembly 410, which is shown and described below in detail with reference to FIG. 11 . The feeding assembly 410 is connected to a coolant supply (e.g., the fluid delivery system 39 of FIG. 1 or the coolant supply 160 of FIG. 2) by a first conduit 412. The coolant flows through the plurality of turns of the coolant channel 400 distributed between the outermost turn 404 and the innermost turn 408. The coolant flows out of the coolant channel 400 through the outlet 406. The outlet 406 is connected to a second conduit 414. The coolant exiting from the outlet 406 is returned to the coolant supply through the second conduit 414.

[0155] The coolant channel 400 is fed with the coolant from an inner side (inner edge) of the outermost turn 404. The inlet 402 is at a radially inner edge of the outermost turn 404. A feeding assembly 410 through which the coolant is fed to the inlet 402 of the coolant channel is shown and described below in detail with reference to FIG. 11 . Since the coolant channel 400 is edge-fed through the inner side (inner edge) of the outermost turn 404, the end portion of the outermost turn 404 is closed or terminated (i.e. , does not have an opening).

[0156] The outermost turn 404 of the coolant channel 400 comprises an inlet portion 420, a rounded portion 422, and a transition portion 424. The inlet portion 420 extends from the end of the outermost turn 404. The rounded portion 422 extends from the end of the inlet portion 420. The transition portion 424 extends from the end of the rounded portion 422. The transition portion 424 of the coolant channel 400 is similar to the transition portion 287 of the coolant channel 300. The remainder of the outermost turn 404 extends from the end of the transition portion 424.

[0157] A top of the inlet portion 420 slopes upwards at an acute angle relative to a plane in which the coolant channel 400 lies in the substrate support 200. The top of the inlet portion 420 slopes upwards at the acute angle from the start of the outermost turn 404(i.e., from the end portion that is terminated). The top of the inlet portion 420 slopes upwards in the direction in which the outermost turn 404 extends. The top of the inlet portion 420 slopes upwards up to the end of the inlet portion 420 (i.e., up to the start of the rounded portion 422). The top of the inlet portion 420 is rounded.

[0158] A top of the rounded portion 422 is rounded from the start to end of the rounded portion 422. The transition portion 424 transitions the shape of the coolant channel 400 from a rounded top of the rounded portion 422 to a flat top in the remainder of the outermost turn 404 without changing the height (depth) of the outermost turn 404. The transition portion 424 is where edge radii of the outermost turn 404 transition into sharp corners at the top edges of the outermost turn 404.

[0159] The turns of the coolant channel 400 spiral radially inwards from the outermost turn 404 to the innermost turn 408. The coolant channel 400 comprises the smooth (curved) jogs 271 around the local features of the substrate support 200. The jogs 271 do not comprise sharp angled turns. The jogs 271 are already described above with reference to the coolant channel 300 and are therefore not described again for brevity.

[0160] Further, the radial distance between some of the turns of the coolant channel 400 can be uniform, non-uniform, or a combination thereof as shown and described below in detail with reference to FIG. 21 . The height (depth) of some of the turns of the coolant channel 400 can be uniform, non-uniform, or a combination thereof as shown and described below in detail with reference to FIG. 22.

[0161] FIGS. 8 and 9 show side views of the coolant channel 400 of FIG. 7. In the side views, different variations of the inlet portion 420 and the rounded portion 422 are shown. In FIG. 8, the inlet portion 420 comprises two sub-portions 420-1 and 420-2. The first sub-portion 420-1 has a first length and slopes upwards at a first angle for a first distance. For example, the first angle can be between 20-35 degrees. The second sub-portion 420- 2 is flat (does not slope), has a second length, and extends for a second distance. The rounded portion 422-1 extends from the second sub-portion 420-2. The rounded portion 422-1 has a third length and slopes upwards for a third distance. The rounded portion 422-1 slopes at a smaller angle than the first angle. The rounded portion 422-1 is longer than the first sub-portion 420-1 and the second sub-portion 420-2. Thereafter, the remainder of the outermost turn 404 spirals horizontally to the plane in which the coolant channel 400 lies in the substrate support 200. The elements 420-1 , 420-2, and 422-1 provide a gradual change in momentum of the coolant as the coolant flows from thefeeding assembly 410 through the inlet 402 into the initial portion of the outermost turn 404.

[0162] In FIG. 9, the inlet portion 420 comprises two sub-portions 420-3 and 420-4. The first sub-portion 420-3 has a fourth length and slopes upwards at a second angle for a fourth distance. The second angle at which the first sub-portion 420-3 slopes upwards is less (shallower) than the first angle at which the first sub-portion 420-1 slopes upwards. For example, the second angle is 15-20 degrees. The fourth distance for which the first sub-portion 420-3 slopes upwards (i.e., the fourth length of the first sub-portion 420-3) is greater than the first distance for which the first sub-portion 420-1 slopes upwards (i.e., the first length of the first sub-portion 420-1). The first sub-portion 420-3 flattens out towards the end. The second sub-portion 420-4 extends from the first sub-portion 420-3.

[0163] The second sub-portion 420-4 is flat (does not slope), has a fifth length, and extends for a fifth distance. The fifth distance for which the second sub-portion 420-4 (i.e., the fifth length of the second sub-portion 420-4) is less than the second distance for which the second sub-portion 420-2 extends (i.e., the second length of the second subportion 420-2).

[0164] The rounded portion 422-2 extends from the second sub-portion 420-4. The rounded portion 422-2 has a sixth length and slopes upwards for a sixth distance. The rounded portion 422-2 slopes upwards at an angle greater than the second angle at which the first sub-portion 420-3 extends. The sixth distance for which the rounded portion 422-2 slopes upwards (i.e., the sixth length of the rounded portion 422-2) is less than the third distance for which the rounded portion 422-1 slopes upwards (i.e., the third length of the rounded portion 422-1 ). Thereafter, the remainder of the outermost turn 404 spirals horizontally to the plane in which the coolant channel 400 lies in the substrate support 200. Relative to the elements 420-1 , 420-2, and 422-1 , the elements 420-3, 420- 4, and 422-2 provide a more gradual change in momentum of the coolant as the coolant flows from the feeding assembly 410 through the inlet 402 into the initial portion of the outermost turn 404.

[0165] FIG. 10 shows a top view of the coolant channel 400 of FIG. 7. In addition to elements 420, 322, and 424, the outermost turn 404 of the coolant channel 400 comprises a portion 426 with a fin 427 that extends downwards into the outermost turn 404. In the portion 426, the height (depth) of the fin 427 gradually changes (e.g., increases) in the direction of the outermost turn 404 to increase thermal conduction alongthe length of the fin 427. The thermal conduction of the fin 427 gradually increases along the length of the fin 427. The height (depth) of the fin 427 can be tuned to reduce the effect of a hot spot around the edges of the substrate support 200. The portion 426 with the fin 427 extends from the end of the transition portion 424 and extends nearly to the end of the outermost turn 404. Thereafter, the remainder of the outermost turn 404 spirals without further variation. Thus, the elements 420, 422, and 424 smooth out the flow of the coolant as the coolant flows from the feeding assembly 410 into the inlet 402 and through the outermost turn 404 into the inner turns of the coolant channel 400. These elements together with the elements 426 and 427 improve temperature uniformity in the periphery (outer region near the OD) of the substrate support 200.

[0166] FIG. 11 shows an example of the feeding assembly 410 that is embedded in the substrate support 200 for feeding coolant into the coolant channel 400 of FIG. 7. FIG. 12 shows a partial cross-sectional view of the substrate support 200 comprising the coolant channel 400 of FIG. 7 and the feeding assembly of FIG. 11 . The feeding assembly 410 and the coolant channel 400 are embedded in the baseplate 202 of the substrate support 200. The feeding assembly 410 comprises an inlet portion 430 and a radial transition portion 432. The inlet portion 430 is in fluid communication with the radial transition portion 432. The inlet portion 430 and the radial transition portion 432 comprise a thermally insulating material.

[0167] In FIG. 12, the inlet portion 430 is fastened to the substrate support 200 by a fastener 434. The inlet portion 430 comprises an inlet 436 that is connected to the coolant supply (e.g., the fluid delivery system 39 of FIG. 1 or the coolant supply 160 of FIG. 2) by the first conduit 412 shown in FIG. 7. The inlet portion 430 is parallel to the plane in which the coolant channel 400 lies in the substrate support 200. The inlet 436 is perpendicular to the inlet portion 430. The inlet 436 turns radially outwards at right angle in the inlet portion 430 and extends through the inlet portion 430 into a passage 433 in the radial transition portion 432. The passage 433 connects to the channel 402.

[0168] In FIG. 1 1 , the radial transition portion 432 extends radially outwards and slopes upwards towards the outermost turn 404 at an angle relative to the plane in which the coolant channel 400 lies in the substrate support 200. The radial transition portion 432 extends laterally from under the turns of the coolant channel 400 towards an inner edge of the outermost turn 404. The radial transition portion 432 connects laterally to the inneredge of the outermost turn 404. The radial transition portion 432 is connected to an inner edge of the inlet portion 420 of the coolant channel 400.

[0169] The radial transition portion 432 slows the momentum of the coolant before the coolant enters into the outermost turn 404. The radial transition portion 432 shallows out any abrupt changes in momentum of the coolant where the spiral coolant channel 400 meets the radial feed to the spiral coolant channel 400. The shallowing out feature is the maximizing of the angle of the abrupt change (e.g., using an obtuse angle such as 125° instead of 90° for the radial transition portion 432 as the coolant enters the substrate support 200). The momentum of the coolant is further smoothened out by the elements 420, 422, and 424 of the outermost turn 404 of the coolant channel 400 as described above.

[0170] The inlet portion 430 and the radial transition portion 432 insulate areas of the coolant channel 400 from the substrate support 200 where geometric constraints create flow nonuniformities, which minimizes or eliminates temperature nonuniformities in these areas of the substrate support 200. The inlet portion 430 and the radial transition portion 432 locally insulate the coolant channel 400 to reduce cooling in the adjacent area of the substrate support 200. Without the inlet portion 430 and the radial transition portion 432, a cold spot can be caused by a sudden or abrupt change of coolant momentum (e.g., where the coolant enters the substrate support 200 from below and has to change direction to flow in the plane of the substrate support 200).

[0171] The coolant channel 400 overcomes the problems of temperature nonuniformities present in the existing coolant channels. The coolant channel 400 overcomes the problems by ensuring consistent coolant flow characteristics in the coolant channel 400 due to all the elements of the coolant channel 400 described above. The coolant channel 400 overcomes the problems by insulating areas of the substrate support where geometric constraints create flow nonuniformities, which minimizes or eliminates temperature nonuniformities in these areas of the substrate support 200. The coolant channel 400 overcomes the problems by feeding the coolant channel 400 as described above such that the geometry of the coolant channel 400 can tune out local temperature non-uniformities. Additionally, the local features of the substrate support 200 such as temperature sensors, power supply lines for the heaters, gas channels, through holes for lift pins, and so on are spaced (relocated) to avoid additive effect of having the jogs 271 of the coolant channel 400 around the local features being too close together.

[0172] The coolant channel 400 comprises the elements described above that remove or minimize local cooling dependencies on temperature dependent properties of a coolant, specifically viscosity. The coolant channel 400 is shaped using the elements described above to minimize change in momentum of the fluid (i.e., coolant) inside the coolant channel 400 that can otherwise cause local cooling to vary from point to point. The design of the coolant channel 400 is optimized (tuned) to avoid cold spots and hot spots over a given temperature range while considering changes in thermal properties such as viscosity of the coolant over the temperature range.THIRD DESIGN OF COOLANT CHANNEL

[0173] A third design of a coolant channel 500 according to the present disclosure is shown and described with reference to FIGS. 13-17. The coolant channel 500 can be used in the substrate support 200 of FIG. 3, which can be used in the processing chambers of FIGS. 1 and 2. FIG. 13 shows a perspective view of the coolant channel 500 that can be used in the substrate supports of FIGS. 1 -3. FIG. 14 shows an expanded partial perspective view of the coolant channel 500 of FIG. 13 showing a plenum for feeding the coolant channel of FIG. 13. FIGS. 15 and 16 show top and bottom views of the plenum of the coolant channel 500 of FIGS. 13 and 14. FIG. 17 shows a partial cross- sectional view of the substrate support 200 comprising the coolant channel 500 of FIGS. 13 and 14.

[0174] FIG. 13 shows a perspective view of the coolant channel 500. The coolant channel 500 is spiral and comprises a plurality of turns. The coolant channel 500 is fed from the bottom by an annular plenum 502 instead of being fed through a single inlet. The plenum 502 has the same outer diameter as the coolant channel 500. The coolant channel 500 and the plenum 502 are embedded in the baseplate 202 of the substrate support 200 shown in FIG. 3. The plenum 502 is disposed directly below the coolant channel 500. The plenum 502 is shown and described below in detail with reference to FIGS. 14-17.

[0175] Briefly, the plenum 502 is connected to an outermost turn 504 of the coolant channel 500 by a plurality of connecting tubes 506 (see FIG. 14). The plurality of connecting tubes 506 are arranged between the top of the plenum 502 and the bottom of the outermost turn 504 of the coolant channel 500. The plenum 502 receives a coolant through an inlet 508 and a feeding assembly 510 (see FIG. 15). The plenum 502 delivers the coolant into the outermost turn 504 of the coolant channel 500 through the pluralityof connecting tubes 506. The coolant channel 500 comprises an outlet 512 in an innermost turn 514 (see FIG. 15). The coolant flows through the plurality of turns of the coolant channel 500 distributed between the outermost turn 504 and the innermost turn 514 of the coolant channel 500. The coolant flows out of the coolant channel 500 through the outlet 512.

[0176] The turns of the coolant channel 500 spiral radially inwards from the outermost turn 504 to the innermost turn 514. The coolant channel 500 comprises the smooth (curved) jogs 271 around the local features of the substrate support 200. The jogs 271 do not comprise sharp angled turns. The jogs 271 are already described above with reference to the coolant channel 300 and are therefore not described again for brevity.

[0177] Further, the radial distance between some of the turns of the coolant channel 500 can be uniform, non-uniform, or a combination thereof as shown and described below in detail with reference to FIG. 21 . The height (depth) of some of the turns of the coolant channel 500 can be uniform, non-uniform, or a combination thereof as shown and described below in detail with reference to FIG. 22.

[0178] FIG. 14 shows an expanded partial perspective view of the coolant channel 500 and the plenum 502 of FIG. 13. The plurality of connecting tubes 506 extend vertically between the top of the plenum 502 and the bottom of the outermost turn 504 of the coolant channel 500. The plurality of connecting tubes 506 between the annulus-shaped plenum 502 and the coolant channel 500 are small in diameter and cross-section relative to the size of the plenum 502 such that each connecting tube 506 has similar pressure / flow from the annulus-shaped plenum 502 into the coolant channel 500.

[0179] FIG. 15 shows a top view of the plenum 502. The plenum 502 is annular. The radial width and cross-sectional area of the plenum 502 are slightly greater than that of the outermost turn 504 of the coolant channel 500 (see FIG. 17). The feeding assembly 510 is connected to the inlet 508. The inlet 508 receives a coolant from a coolant supply (e.g., the fluid delivery system 39 shown in FIG. 1 or the coolant supply 160 shown in FIG. 2).

[0180] The feeding assembly 510 is attached to the inlet 508 and the plenum 502. The feeding assembly 510 extends radially outwards from the inlet 508 and is attached laterally to an inner edge of the plenum 502. The feeding assembly 510 extends radially outwards from under the coolant channel 500 towards the inner edge of the plenum 502 and is connected laterally to the inner edge of the plenum 502. The feeding assembly510 supplies the coolant to the plenum 502. The coolant from the plenum 502 flows through the plurality of connecting tubes 506 into the outermost turn 504 of the coolant channel 500. The coolant flows through the turns of the coolant channel 500 and exits through the outlet 512. The outlet 512 is connected to the coolant supply and returns the coolant to the coolant supply.

[0181] FIG. 16 shows a bottom view of the plenum 502 of the coolant channel 500. The plurality of connecting tubes 506 can be distributed throughout the circumference of the plenum 502. The distribution of the plurality of connecting tubes 506 as well as the spacing between the plurality of connecting tubes 506 can be uniform in some portions of the plenum and nonuniform in other portions of the plenum 502. The distribution and the spacing of the plurality of connecting tubes 506 can be set or predetermined (tuned) to improve the temperature uniformity in the peripheral (outer) region of the baseplate 202 of the substrate support 200. By adding, removing, and adjusting spacing between individual connecting tubes 506, azimuthal uniformity from the annular plenum 502 to the coolant channel 500 can be tuned to remove hot or cold spots in the substrate support 200.

[0182] FIG. 17 shows a partial cross-sectional view of the substrate support 200 comprising the coolant channel 500. The plenum 502 has the same outer diameter as the coolant channel 500. The radial width and cross-sectional area of the plenum 502 are slightly greater than that of the outermost turn 504 of the coolant channel 500.

[0183] The coolant channel 500 overcomes the problems of temperature nonuniformities present in the existing coolant channels. The coolant channel 500 overcomes the problems by ensuring consistent coolant flow characteristics in the coolant channel 500 due to all the elements of the coolant channel 500 described above. The coolant channel 500 overcomes the problems by insulating areas of the substrate support where geometric constraints create flow nonuniformities, which minimizes or eliminates temperature nonuniformities in these areas of the substrate support 200. The coolant channel 500 overcomes the problems by feeding the coolant channel 500 using the annular plenum 502 and the connecting tubes 506 as described above such that the geometry of the coolant channel 500 can tune out local temperature non-uniformities. Additionally, the local features of the substrate support 200 such as temperature sensors, power supply lines for the heaters, gas channels, through holes for lift pins, and so onare spaced (relocated) to avoid additive effect of having the jogs 271 of the coolant channel 500 around the local features being too close together.

[0184] The coolant channel 500 comprises the elements described above that remove or minimize local cooling dependencies on temperature dependent properties of a coolant, specifically viscosity. The coolant channel 500 is fed by the plenum 502 and the plurality of connecting tubes 506 as described above to minimize change in momentum of the fluid (i.e., coolant) inside the coolant channel 500 that can otherwise cause local cooling to vary from point to point. The design of the coolant channel 500 is optimized (tuned) to avoid cold spots and hot spots over a given temperature range while considering changes in thermal properties such as viscosity of the coolant over the temperature range.SUBSTRATE SUPPORT WITH VOIDS

[0185] A design of a substrate support comprising voids according to the present disclosure is shown and described with reference to FIGS. 18-20. The voids can be implemented in the substrate support 200 shown in FIG. 3. The substrate support of FIGS. 18-20 can comprise any of the coolant channels of FIGS. 4-17. The substrate support of FIGS. 21 -23 can be used in the processing chambers of FIGS. 1 and 2. FIG. 18 shows a top view of a design of a substrate support (e.g., substrate supports of FIGS. 1 -3), which comprises voids and any of the coolant channels 300, 400, 500 of FIGS. 4- 17, and which can be used in processing chambers of FIGS. 1 and 2. FIGS. 19 and 20 show partial cross-sectional views of the substrate support of FIG. 18.

[0186] FIG. 18 shows a top view of a design of a substrate support (e.g., substrate supports of FIGS. 1 -3), which comprises voids and any of the coolant channels 300, 400, 500 of FIGS. 4-17, and which can be used in processing chambers of FIGS. 1 and 2. Various examples of voids are shown at 600-1 , 600-2, 600-3, 600-3, 600-4, 600-5, and 600-6 (collectively called the voids 600). The voids 600 can be of any shape and size. The voids 600 can have uniform shape and size. The voids 600 can have nonuniform shapes and sizes. The voids 600 can be grouped and distributed in the substrate support 200 in many ways. The voids 600 of uniform and nonuniform shapes and sizes can be grouped and distributed in the substrate support 200. A group of voids 600 can comprise voids of uniform shape and size. A group of voids 600 can comprise voids of nonuniform shapes and sizes.

[0187] In the substrate support 200, the voids 600 are formed in the baseplate 202. The voids 600 lie above the coolant channel 206. The voids 600 are created between the coolant channel 206 and the top surface of the substrate support 200 on which the substrate 208 is arranged. The voids 600 act as thermal insulators. For example, in the manufacturing process of the ESC (e.g., the substrate support 200) that uses a layered construction of the ESC, a void (e.g., any of the voids 600) can be constructed as an opening between two successive layers of the brazement of the ESC. The void can be constructed by machining the face of one layer before brazing the two layers together, and then not using that opening between the brazed layers for any other function. The voids 600 can comprise air or vacuum to provide thermal insulation. The geometries of the voids 600 can be tuned as described below to compensate more for a colder spot below or less for a spot that is not as cold below the voids 600.

[0188] In general, the voids 600 are formed between a center region of the substrate support 200 and an outer peripheral region of the substrate support 200. For example, the voids 600 extend radially in the substrate support 200 from a first radial distance r1 to a second radial distance r2, where r2 is less than the OD of the substrate support 200. The voids 600 can have uniform or non-uniform height (depth). Some of the voids (e.g., 600-2, 600-4, 600-6) may also be radially discontinuous to accommodate the local features 273 of the substrate support 200.

[0189] FIGS. 19 and 20 show partial cross-sectional views of the substrate support 200 of FIG. 18. For example, FIG. 19 shows an example of a radially continuous void 602. FIG. 20 shows an example of radially discontinuous voids 604, 606. The voids 603, 604, 606 shown in FIGS. 19 and 20 can be any of the voids 600 shown in FIG. 18. The voids 604, 606 accommodate the features (fitments) 273 of the substrate support 200.

[0190] For example, the void 602 has a greater height than the voids 604, 606. For example, the void 602 is located closer to the top surface of the substrate support 200 than the voids 604, 606. While not shown, the spacing between the top surface of the substrate support 200 and the voids 604, 606 can be different. Further, while not shown, the voids 604, 606 can have different height (depth). Accordingly, two portions of a radially discontinuous void can be spaced differently from the top surface of the substrate support 200, can have different height (depth), or both. Furthermore, the voids 600 can be spaced apart from each other uniformly, non-uniformly, or both.ADDITIONAL FEATURES

[0191] FIGS. 21 and 22 show additional features of the coolant channels 300, 400, 500 of FIGS. 4-17. The substrate support of FIGS. 18-20 can comprise any of the coolant channels of FIGS. 4-17 and can further comprise the additional features of FIGS. 21 and 22. FIG. 21 shows radial (lateral) spacing between turns of the coolant channels 300, 400, 500 of FIGS. 4-17. FIG. 22 shows height of the turns of the coolant channels 300, 400, 500 of FIGS. 4-17 relative to the top surface of the substrate support 200 when any of the coolant channels 300, 400, 500 of FIGS. 4-17 is disposed in the substrate support 200.

[0192] FIG. 21 show radial (lateral) spacing between turns of the coolant channels 300, 400, 500 of FIGS. 4-17. For example, some turns of the coolant channel may be spaced uniformly from each other (e.g., turns shown separated by a distance d2 between them). For example, some turns of the coolant channel may be spaced nonuniformly from each other (e.g., turns shown separated by a distances d1 and d3, where d1 > d2 and d3 < d2, for example).

[0193] FIG. 22 shows height of the turns of the coolant channels 300, 400, 500 of FIGS. 4-17 relative to the top surface of the substrate support 200 when any of the coolant channels 300, 400, 500 of FIGS. 4-17 is disposed in the substrate support 200. For example, some turns of the coolant channel may be spaced uniformly from the top surface of the substrate support 200 (e.g., turns shown separated by a distance hi from the top surface of the substrate support 200). For example, some turns of the coolant channel may be spaced nonuniformly from each other (e.g., turns shown separated by a distances h2 and h3 from the top surface of the substrate support 200, where h2 > hi and h3 < hi , for example). While not shown, the turns of the coolant channels 300, 400, 500 can be spaced from each other and from the top surface of the substrate support 200 using any combination of the distances shown in FIGS. 21 and 22.

[0194] In all of the designs of the coolant channels described above, the base or the bottom of each of the coolant channels is flat (i.e., parallel to the plane in which the coolant channels lie in the substrate support 200). In the coolant channel 500, the bottom of the plenum 502 is also flat (i.e., parallel to the plane in which the coolant channels lie in the substrate support 200).

[0195] The substrate support 200 can comprise the voids 600 having any combination of the features described above with reference to FIGS. 18-20. Additionally, the substrate support 200 can comprise any of the coolant channels 300, 400, 500 with anycombination of the features of the coolant channels 300, 400, 500 described above with reference to FIGS. 4-17 and FIGS. 21 and 22.

[0196] The foregoing description is merely illustrative in nature and is not intended to limit the disclosure, its application, or uses. The broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent upon a study of the drawings, the specification, and the following claims.

[0197] It should be understood that one or more steps within a method may be executed in different order (or concurrently) without altering the principles of the present disclosure. Further, although each of the examples is described above as having certain features, any one or more of those features described with respect to any one of the examples of the disclosure can be implemented in and / or combined with features of any of the other examples, even if that combination is not explicitly described. In other words, the described examples are not mutually exclusive, and permutations of one or more examples with one another remain within the scope of this disclosure.

[0198] Spatial and functional relationships between elements (for example, between modules, circuit elements, semiconductor layers, etc.) are described using various terms, including “connected,” “engaged,” “coupled,” “adjacent,” “next to,” “on top of,” “above,” “below,” and “disposed.” Unless explicitly described as being “direct,” when a relationship between first and second elements is described in the above disclosure, that relationship can be a direct relationship where no other intervening elements are present between the first and second elements, but can also be an indirect relationship where one or more intervening elements are present (either spatially or functionally) between the first and second elements. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A OR B OR C), using a non-exclusive logical OR, and should not be construed to mean “at least one of A, at least one of B, and at least one of C.”

[0199] In some implementations, a controller is part of a system, which may be part of the above-described examples. Such systems can comprise semiconductor processing equipment, including a processing tool or tools, chamber or chambers, a platform or platforms for processing, and / or specific processing components (a wafer pedestal, a gas flow system, etc.). These systems may be integrated with electronics for controlling their operation before, during, and after processing of a semiconductor wafer or substrate.

[0200] The electronics may be referred to as the “controller,” which may control various components or subparts of the system or systems. The controller, depending on the processing requirements and / or the type of system, may be programmed to control any of the processes disclosed herein, including the delivery of processing gases, temperature settings (e.g., heating and / or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow rate settings, fluid delivery settings, positional and operation settings, wafer transfers into and out of a tool and other transfer tools and / or load locks connected to or interfaced with a specific system.

[0201] Broadly speaking, the controller may be defined as electronics having various integrated circuits, logic, non-transitory memory, and / or software that receive instructions, issue instructions, control operation, enable cleaning operations, enable endpoint measurements, and the like. The integrated circuits may include chips in the form of firmware that store program instructions, digital signal processors (DSPs), chips defined as application specific integrated circuits (ASICs), and / or one or more microprocessors, or microcontrollers that execute program instructions (e.g., software).

[0202] Program instructions may be instructions communicated to the controller in the form of various individual settings (or program files), defining operational parameters for carrying out a particular process on or for a semiconductor wafer or to a system. The operational parameters may, in some examples, be part of a recipe defined by process engineers to accomplish one or more processing steps during the fabrication of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or dies of a wafer.

[0203] The controller, in some implementations, may be a part of or coupled to a computer that is integrated with the system, coupled to the system, otherwise networked to the system, or a combination thereof. For example, the controller may be in the “cloud” or all or a part of a fab host computer system, which can allow for remote access of the wafer processing. The computer may enable remote access to the system to monitor current progress of fabrication operations, examine a history of past fabrication operations, examine trends or performance metrics from a plurality of fabrication operations, to change parameters of current processing, to set processing steps to follow a current processing, or to start a new process.

[0204] In some examples, a remote computer (e.g., a server) can provide process recipes to a system over a network, which may include a local network or the Internet. The remote computer may include a user interface that enables entry or programming of parameters and / or settings, which are then communicated to the system from the remote computer. In some examples, the controller receives instructions in the form of data, which specify parameters for each of the processing steps to be performed during one or more operations. It should be understood that the parameters may be specific to the type of process to be performed and the type of tool that the controller is configured to interface with or control.

[0205] Thus, as described above, the controller may be distributed, such as by comprising one or more discrete controllers that are networked together and working towards a common purpose, such as the processes and controls described herein. An example of a distributed controller for such purposes would be one or more integrated circuits on a chamber in communication with one or more integrated circuits located remotely (such as at the platform level or as part of a remote computer) that combine to control a process on the chamber.

[0206] Without limitation, example systems may include a plasma etch chamber or module, a deposition chamber or module, a spin-rinse chamber or module, a metal plating chamber or module, a clean chamber or module, a bevel edge etch chamber or module, a physical vapor deposition (PVD) chamber or module, a chemical vapor deposition (CVD) chamber or module, an atomic layer deposition (ALD) chamber or module, an atomic layer etch (ALE) chamber or module, an ion implantation chamber or module, a track chamber or module, and any other semiconductor processing systems that may be associated or used in the fabrication and / or manufacturing of semiconductor wafers.

[0207] As noted above, depending on the process step or steps to be performed by the tool, the controller might communicate with one or more of other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, neighboring tools, tools located throughout a factory, a main computer, another controller, or tools used in material transport that bring containers of wafers to and from tool locations and / or load ports in a semiconductor manufacturing factory.

Claims

CLAIMSWhat is claimed is:1 . A substrate support for supporting a substrate comprising: a baseplate; and a coolant channel arranged in the baseplate, the coolant channel comprising: a plurality of turns distributed between an outer diameter of the substrate support to a center of the substrate support; and an inlet for a coolant connected to an outermost turn of the plurality of turns, the inlet being tilted relative to an axis perpendicular to a plane in which the coolant channel lies in the substrate support.

2. The substrate support of claim 1 wherein the inlet is tilted towards the outermost turn at an acute angle relative to the axis perpendicular to the plane in which the coolant channel lies in the substrate support.

3. The substrate support of claim 1 wherein the plurality of turns comprise inner turns and outer turns, wherein the outer turns including the outermost turn are semi-circular and change turning direction proximate to the inlet, and wherein the inner turns are spiral and extend to the center of the substrate support.

4. The substrate support of claim 1 wherein the outermost turn changes turning direction proximate to the inlet, and wherein a portion of the outermost turn where the outermost turn changes turning direction is radially wider than a remainder of the outermost turn.

5. The substrate support of claim 1 wherein the plurality of turns comprise inner turns and outer turns, wherein the outer turns including the outermost turn are semi-circular and change turning direction proximate to the inlet, and wherein portions of the outer turns where the outer turns change turning direction are radially wider than a remainder of the outer turns.

6. The substrate support of claim 1 wherein the plurality of turns comprise additional curved portions that curve around fitments in the substrate support.

7. The substrate support of claim 1 wherein the outermost turn further comprises: an inlet portion extending from the inlet, the inlet portion being tilted towards the outermost turn at an acute angle relative to the axis perpendicular to the plane in which the coolant channel lies in the substrate support; a tapered portion extending from the inlet portion, the tapered portion comprising a tapered top portion sloping upwards; and a rounded portion extending from the tapered portion, the rounded portion comprising a rounded top portion.

8. The substrate support of claim 7 wherein top portions of the inlet portion and the tapered portion are rounded.

9. The substrate support of claim 7 wherein the outermost turn further comprises a transition portion that extends from the rounded portion and that transitions a shape of the outermost turn from the rounded top portion of the rounded portion to a flat top portion in a remainder of the outermost turn.

10. The substrate support of claim 1 wherein at least some turns of the plurality of turns are spaced from each other by the same distance.11 . The substrate support of claim 1 wherein a first set of turns of the plurality of turns are spaced from each other by a first distance and wherein at least one turn of the plurality of turns is spaced from one turn in the first set of the turns by a second distance.

12. The substrate support of claim 1 wherein at least some turns of the plurality of turns are spaced from a top surface of the substrate support by the same distance.

13. The substrate support of claim 1 wherein a first set of turns of the plurality of turns are spaced from a top surface of the substrate support by a first distance and wherein at least one turn of the plurality of turns is spaced from the top surface of the substrate support by a second distance.

14. The substrate support of claim 1 further comprising a plurality of voids between the coolant channel and a top surface of the substrate support.

15. The substrate support of claim 14 wherein the plurality of voids is distributed between a first radial distance from the center of the substrate support and a second radial distance from the center of the substrate support.

16. The substrate support of claim 14 wherein at least some voids of the plurality of voids extend radially between a first radial distance from the center of the substrate support and a second radial distance from the center of the substrate support.

17. The substrate support of claim 16 wherein at least some voids of the plurality of voids are discontinuous around fitments in the substrate support.

18. The substrate support of claim 14 wherein at least some voids of the plurality of voids are spaced from each other by the same distance.

19. The substrate support of claim 14 wherein a first set of voids of the plurality of voids are spaced from each other by a first distance and wherein at least one void of the plurality of voids is spaced from one void in the first set of the voids by a second distance.

20. The substrate support of claim 14 wherein at least some voids of the plurality of voids are spaced from the top surface of the substrate support by the same distance.

21. The substrate support of claim 14 wherein a first set of voids of the plurality of voids are spaced from the top surface of the substrate support by a first distance and wherein at least one void of the plurality of voids is spaced from the top surface of the substrate support by a second distance.

22. The substrate support of claim 1 wherein the plurality of turns comprises an inner most turn having an outlet for the coolant.

23. A substrate support for supporting a substrate comprising: a baseplate; and a coolant channel arranged in the baseplate, the coolant channel comprising: a plurality of turns distributed between an outer diameter of the substrate support to a center of the substrate support; anda feeding assembly connected to an inner edge of an outermost turn of the plurality of turns to feed a coolant to the outermost turn of the coolant channel.

24. The substrate support of claim 23 wherein the feeding assembly comprises: an inlet portion that is parallel to a plane in which the coolant channel lies in the substrate support; and a radial transition portion that slopes at an acute angle relative to the plane in which the coolant channel lies in the substrate support and that is connected to the inner edge of the outermost turn.

25. The substrate support of claim 23 wherein the feeding assembly extends radially outwards and slopes upwards from under the coolant channel towards the outermost turn and is connected laterally to the inner edge of the outermost turn.

26. The substrate support of claim 23 wherein: the plurality of turns spiral from the outer diameter of the substrate support to the center of the substrate support; and the plurality of turns comprise additional curved portions that curve around fitments in the substrate support.

27. The substrate support of claim 23 wherein the outermost turn comprises an inlet portion connected to the feeding assembly, a top of the inlet portion being rounded and sloping upwards at a first acute angle relative to a plane in which the coolant channel lies in the substrate support in a direction in which the outermost turn extends.

28. The substrate support of claim 27 wherein the outermost turn further comprises: a rounded portion extending from the inlet portion, the rounded portion comprising a rounded top portion; and a transition portion extending from the rounded portion, the transition portion transitioning a shape of the outermost turn from the rounded top portion of the rounded portion to a flat top portion in a remainder of the outermost turn.

29. The substrate support of claim 28 wherein the outermost turn further comprises a portion that extends from the transition portion up to an end of the outermost turn wherein the portion comprises a fin that extends downwards into the outermost turn.

30. The substrate support of claim 29 wherein a depth of the fin in the portion changes from the transition portion up to the end of the outermost turn.31 . The substrate support of claim 23 wherein at least some turns of the plurality of turns are spaced from each other by the same distance.

32. The substrate support of claim 23 wherein a first set of turns of the plurality of turns are spaced from each other by a first distance and wherein at least one turn of the plurality of turns is spaced from one turn in the first set of the turns by a second distance.

33. The substrate support of claim 23 wherein at least some turns of the plurality of turns are spaced from a top surface of the substrate support by the same distance.

34. The substrate support of claim 23 wherein a first set of turns of the plurality of turns are spaced from a top surface of the substrate support by a first distance and wherein at least one turn of the plurality of turns is spaced from the top surface of the substrate support by a second distance.

35. The substrate support of claim 23 further comprising a plurality of voids between the coolant channel and a top surface of the substrate support.

36. The substrate support of claim 35 wherein the plurality of voids is distributed between a first radial distance from the center of the substrate support and a second radial distance from the center of the substrate support.

37. The substrate support of claim 35 wherein at least some voids of the plurality of voids extend radially between a first radial distance from the center of the substrate support and a second radial distance from the center of the substrate support.

38. The substrate support of claim 37 wherein at least some voids of the plurality of voids are discontinuous around fitments in the substrate support.

39. The substrate support of claim 35 wherein at least some voids of the plurality of voids are spaced from each other by the same distance.

40. The substrate support of claim 35 wherein a first set of voids of the plurality of voids are spaced from each other by a first distance and wherein at least one void of the plurality of voids is spaced from one void in the first set of the voids by a second distance.41 . The substrate support of claim 35 wherein at least some voids of the plurality of voids are spaced from the top surface of the substrate support by the same distance.

42. The substrate support of claim 35 wherein a first set of voids of the plurality of voids are spaced from the top surface of the substrate support by a first distance and wherein at least one void of the plurality of voids is spaced from the top surface of the substrate support by a second distance.

43. The substrate support of claim 23 wherein the plurality of turns comprises an inner most turn having an outlet for the coolant.

44. A substrate support for supporting a substrate comprising: a baseplate; and a coolant channel arranged in the baseplate, the coolant channel comprising a plurality of turns distributed between an outer diameter of the substrate support to a center of the substrate support; and a plenum connected to an outermost turn of the plurality of turns to supply a coolant to the outermost turn of the coolant channel.

45. The substrate support of claim 44 wherein the plenum is annular and is connected to the outermost turn by a plurality of connecting tubes distributed circumferentially between the plenum and the outermost turn.

46. The substrate support of claim 44 further comprising a feeding assembly connected to an inner edge of the plenum.

47. The substrate support of claim 46 wherein the feeding assembly extends radially outwards from under the coolant channel towards the inner edge of the plenum and is connected laterally to the inner edge of the plenum.

48. The substrate support of claim 44 wherein:the plurality of turns spiral from the outer diameter of the substrate support to the center of the substrate support; and the plurality of turns comprise additional curved portions that curve around fitments in the substrate support.

49. The substrate support of claim 44 wherein at least some turns of the plurality of turns are spaced from each other by the same distance.

50. The substrate support of claim 44 wherein a first set of turns of the plurality of turns are spaced from each other by a first distance and wherein at least one turn of the plurality of turns is spaced from one turn in the first set of the turns by a second distance.51 . The substrate support of claim 44 wherein at least some turns of the plurality of turns are spaced from a top surface of the substrate support by the same distance.

52. The substrate support of claim 44 wherein a first set of turns of the plurality of turns are spaced from a top surface of the substrate support by a first distance and wherein at least one turn of the plurality of turns is spaced from the top surface of the substrate support by a second distance.

53. The substrate support of claim 44 further comprising a plurality of voids between the coolant channel and a top surface of the substrate support.

54. The substrate support of claim 53 wherein the plurality of voids is distributed between a first radial distance from the center of the substrate support and a second radial distance from the center of the substrate support.

55. The substrate support of claim 53 wherein at least some voids of the plurality of voids extend radially between a first radial distance from the center of the substrate support and a second radial distance from the center of the substrate support.

56. The substrate support of claim 55 wherein at least some voids of the plurality of voids are discontinuous around fitments in the substrate support.

57. The substrate support of claim 53 wherein at least some voids of the plurality of voids are spaced from each other by the same distance.

58. The substrate support of claim 53 wherein a first set of voids of the plurality of voids are spaced from each other by a first distance and wherein at least one void of the plurality of voids is spaced from one void in the first set of the voids by a second distance.

59. The substrate support of claim 53 wherein at least some voids of the plurality of voids are spaced from the top surface of the substrate support by the same distance.

60. The substrate support of claim 53 wherein a first set of voids of the plurality of voids are spaced from the top surface of the substrate support by a first distance and wherein at least one void of the plurality of voids is spaced from the top surface of the substrate support by a second distance.61 . The substrate support of claim 44 wherein the plurality of turns comprises an inner most turn having an outlet for the coolant.

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