Cooling base for substrate support

Abstract

In one example, a substrate support assembly having a cooling base that promotes temperature uniformity is provided. In one embodiment, the cooling base has a top plate. The top plate has cooling channels formed therein. The cooling base has an intermediate plate. The intermediate plate has a cooling return plenum disposed on the intermediate layer. A plurality of islands are disposed within the cooling return plenum. The intermediate plate has a cooling supply plenum disposed below the intermediate layer. A plurality of cooling inlets are disposed through the islands and couple the cooling supply plenum to the cooling channels. Cooling outlets fluidly couple the cooling channels to the cooling return plenum. The cooling base has a bottom plate. The bottom plate has cooling inlets fluidly coupled to the cooling supply plenum and cooling outlets fluidly coupled to the cooling return plenum.

Description

Technology Field

[0002] The embodiments described in this specification generally relate to semiconductor manufacturing, and more specifically to substrate support assemblies suitable for high-temperature semiconductor manufacturing. Background Technology

[0004] Reliably producing nanometer and smaller features is one of the key technological challenges for next-generation Very Large Scale Integration (VLSI) and Ultra-Large Scale Integration (ULSI) semiconductor devices. However, as the limitations of circuit technology expand, the shrinking dimensions of VLSI and ULSI interconnect technologies have imposed additional demands on processing capabilities. The reliable formation of gate structures on substrates is critical to the success of VLSI and ULSI, as well as to ongoing efforts to increase circuit density and the quality of discrete substrates.

[0005] To drive down manufacturing costs, integrated chip (IC) manufacturers require higher throughput and better device yield and performance from every silicon substrate processed. Improving the temperature uniformity of electrostatic chucks has been identified as an area where device yield can be improved. Conventional electrostatic chucks are typically bonded to cooling plates within a substrate support assembly. Conventional electrostatic chucks utilize multiple heaters in conjunction with the cooling plates to maintain temperature control along the surface of the silicon substrate during processing. However, conventional cooling bases do not always possess rotational or azimuthal temperature symmetry. Currently, cooling bases flow cooling liquid through plenums, which cannot always prevent higher temperatures in specific areas due to the plasma formed within the chamber and the heat flux from the chuck heaters. Additionally, local cold spots are often associated with parts of the cooling base—where lift fins, thermocouples, power lines, and He supply lines penetrate these parts of the cooling base. Temperature non-uniformity across the substrate support distorts the processing results for substrates processed on the substrate support. Therefore, correcting substrate support temperature non-uniformity lowers throughput and reduces device yield and performance for processing chambers.

[0006] Therefore, there is a need for an improved substrate support assembly.

[0007] In one example, a cooling base that promotes temperature uniformity is provided. In one embodiment, the cooling base has a top plate. The top plate has cooling channels formed therein. The cooling base has an intermediate plate disposed below the top plate. The intermediate plate has a cooling return plenum disposed on the intermediate layer. A plurality of islands are disposed within the cooling return plenum. The intermediate plate has a cooling supply plenum disposed below the intermediate layer. A plurality of cooling inlets are disposed through the islands and couple the cooling supply plenum to the cooling channels. Cooling outlets fluidly couple the cooling channels to the cooling return plenum. The cooling base has a bottom plate disposed below the intermediate plate. The bottom plate has cooling inlets fluidly coupled to the cooling supply plenum and cooling outlets fluidly coupled to the cooling return plenum.

[0008] In another example, a substrate support assembly having a cooling base that promotes temperature uniformity is provided. The substrate support assembly has a substrate support and a cooling base coupled to the substrate support. The cooling base has a top plate. The top plate has cooling channels formed internally. The cooling base has an intermediate plate disposed below the top plate. The intermediate plate has a cooling return plenum disposed on the intermediate layer. A plurality of islands are disposed within the cooling return plenum. The intermediate plate has a cooling supply plenum disposed below the intermediate layer. A plurality of cooling inlets are disposed through the islands and couple the cooling supply plenum to the cooling channels. Cooling outlets fluidly couple the cooling channels to the cooling return plenum. The cooling base has a bottom plate disposed below the intermediate plate. The bottom plate has cooling inlets fluidly coupled to the cooling supply plenum and cooling outlets fluidly coupled to the cooling return plenum.

[0009] In another example, a method for controlling the temperature of a substrate support disposed on a cooling base is provided. The method begins by flowing a cooling fluid into a cooling fluid inlet plenum disposed within an intermediate plate of the cooling base. The cooling fluid flows from the cooling fluid inlet plenum into one of a plurality of cooling channels within the uppermost plate of the cooling base. Then, the cooling fluid from the cooling channel flows through a cooling fluid outlet into a cooling fluid return plenum disposed within the intermediate plate, the cooling fluid return plenum being perpendicularly adjacent to the cooling fluid supply plenum. Brief explanation of the drawing

[0010] In a manner that the features of the above-mentioned disclosure can be understood in detail, a more specific description of the disclosure briefly summarized above may be made with reference to embodiments, some of which are illustrated in the accompanying drawings. However, it should be noted that the accompanying drawings illustrate only ordinary embodiments of the disclosure and should not be construed as limiting the scope of the disclosure, as the disclosure may allow for other equally valid embodiments.

[0011] FIG. 1 is a schematic side cross-sectional view of a processing chamber having one embodiment of a substrate support assembly.

[0012] Figure 2 is a plan view of a conventional cooling base for a substrate support assembly.

[0013] FIGS. 3a and FIGS. 3b are isometric cross-sectional views of an improved cooling base suitable for use in the processing chamber (100) of FIG. 1.

[0014] FIG. 4 is a side plan view of a cooling base exposing all cooling channels.

[0015] FIG. 5 is a plan view of an intermediate plate in a cooling base that exposes all cooling inlet holes and outlet holes.

[0016] Figure 6 illustrates a method for cooling a substrate support using the cooling bases of Figures 3a and 3b.

[0017] For clarity, where applicable, the same reference numbers have been used to designate identical elements common to the drawings. Additionally, elements of one embodiment may be advantageously configured for use in other embodiments described herein. Specific details for implementing the invention

[0018] The embodiments described herein provide a substrate support assembly that improves temperature uniformity during operation. The substrate support assembly has a substrate support bonded to a cooling base. The cooling base has a cooling region adjacent to the substrate support. The cooling base is configured to have shortened cooling paths within the cooling region adjacent to the substrate support. Each cooling path has inlets and outlets to provide coolant flow to different zones, such as five different concentric zones, in such a manner that heat removal from each different zone can be the same or different as needed. The cooling base plate is made of multiple layers to facilitate multiple inflows of cooling fluid from the inlets to the top surface of the cooling base. The cooling base outlet provides an immediate discharge path for the cooling fluid from the top surface to shorten the time and cooling fluid path within the hot zone to improve cooling throughout the cooling region. The travel distance for the cooling fluid within the cooling region is short, which maintains the same cooling efficiency throughout the entire cooling region.

[0019] FIG. 1 is a schematic cross-sectional view of an exemplary plasma processing chamber (100) configured as an etching chamber having a substrate support assembly (172). The substrate support assembly (172) can be utilized in other types of plasma processing chambers, for example, plasma processing chambers, annealing chambers, physical vapor deposition chambers, chemical vapor deposition chambers, and ion implantation chambers, as well as in other systems where the ability to control processing uniformity across a surface such as a substrate or a workpiece is desirable.

[0020] A plasma processing chamber (100) comprises a chamber body (102), which has side walls (104), a bottom (106), and a cover (108) surrounding a processing zone (110). An injection device (112) is coupled to the side walls (104) and / or the cover (108) of the chamber body (102). A gas panel (114) is coupled to the injection device (112) to allow process gases to be supplied into the processing zone (110). The injection device (112) may be one or more nozzles or inlet ports, or alternatively, a showerhead. Processing gases, along with any processing byproducts, are removed from the processing zone (110) through an exhaust port (128) formed in the side walls (104) or the bottom (106) of the chamber body (102). The exhaust port (128) is coupled to a pumping system (132) including throttle valves and pumps used to control vacuum levels within the processing zone (110).

[0021] The processing gas can be energized to form a plasma within the processing zone (110). The processing gas can be energized by capacitively or inductively coupling RF power to the processing gases. In the embodiment depicted in FIG. 1, a plurality of coils (116) are placed over the cover (108) of the plasma processing chamber (100) and coupled to an RF power source (120) through a matching circuit (118) to inductively couple RF power to the processing gas.

[0022] A substrate support assembly (172) is positioned within the processing zone (110) and below the injection device (112). The substrate support assembly (172) may include a substrate support (174), a cooling base (126), a facility plate (145), and a base plate (176). If reduced cooling is acceptable, a conventional cooling base (130) may be used in the substrate support assembly (172) instead of the cooling base (126). The base plate (176) is supported by either the side walls (104) or the bottom (106) of the processing chamber. The substrate support assembly (172) may additionally include a heater assembly (not shown). Additionally, the substrate support assembly (172) may include an insulator plate (not shown) positioned between the conventional cooling base (130) and the base plate (176).

[0023] The substrate support (174) may be a heater, an electrostatic chuck (ESC), or other suitable structure for supporting the substrate (124) during processing within the plasma processing chamber (100). The substrate support (174) has a dielectric body (175). The dielectric body (175) has a workpiece support surface (137) and a bottom surface (133) facing the workpiece support surface (137). The substrate support (174) may also include lift pin holes for receiving lift pins (not shown) for raising the substrate (124) over the workpiece support surface (137) to facilitate robotic transfer into and out of the plasma processing chamber (100).

[0024] The workpiece support surface (137) may include gas passages (194). The gas passages (194) are coupled to a rear gas source (192). The rear gas source (192) provides inert gas through the gas passages (194) into the interstitial space defined between the substrate (124) and the workpiece support surface (137) of the substrate support (174), thereby providing heat transfer and cooling the substrate (124). The gas passages (194) may be arranged within one or more zones. For example, the gas passages (194) may be arranged within three concentric, independently controlled zones for better azimuth temperature control of the workpiece support surface (137). In another example, the substrate support (174) has gas passages (194) arranged within four concentric, independently controllable zones.

[0025] When configured as an electrostatic chuck, the substrate support (174) may include a chucking electrode (186) embedded within a dielectric body (175). The chucking electrode (186) may be configured as a unipolar or bipolar electrode, or other suitable arrangement. The chucking electrode (186) is coupled to a chucking power source (187) through an RF filter, and the chucking power source (187) provides RF or DC power to electrostatically fix the substrate (124) to the workpiece support surface (137) of the substrate support (174).

[0026] The dielectric body (175) may also include one or more resistive heaters (188) embedded therein. The resistive heaters (188) may be provided to raise the temperature of the workpiece support surface (137) to a temperature suitable for processing the substrate (124) placed on the workpiece support surface (137). The resistive heaters (188) are coupled to a heater power source (189) through a facility plate (145) to energize and control the resistive heaters (188).

[0027] The cooling base (126) is supported by a base plate (176). The cooling base (126) may include cooling features (190) formed internally. The cooling features (190) may be connected to a heat transfer fluid source (122). The heat transfer fluid source (122) provides a heat transfer fluid, such as a liquid, gas, or a combination thereof, that circulates through one or more cooling features (190) disposed within the cooling base (126). In one embodiment, the heat transfer fluid source (122) may provide a perfluorinated polyether cooling fluid of about 40 degrees Celsius at about 4 gallons per minute. The fluid flowing through neighboring cooling features (190) may be isolated to enable local control of heat transfer between different zones of the substrate support (174) and the cooling base (126), which assists in controlling the lateral temperature profile of the substrate (124). In one embodiment, a heat transfer fluid circulating through the cooling features (190) of the cooling base (126) maintains the cooling base (126) at a temperature of about 90 degrees Celsius to about 80 degrees Celsius or at a temperature lower than 90 degrees Celsius.

[0028] A substrate support (174) may be placed on a cooling base (126). The cooling base (126) may be bonded to the substrate support (174) by an adhesive layer. The adhesive layer may have a thermal conductivity of about 0.1 W / mK to about 1 W / mK, e.g., about 0.17 W / mK. A plurality of fluid passages may be formed on the upper surface of the cooling base (126) to control the temperature between the substrate support (174) and the cooling base (126). The lower surface of the cooling base (126) may be placed on a facility plate (145), a heater, or a base plate (176).

[0029] FIG. 2 is a plan view of a conventional cooling base (130) with a cap removed to expose one of the plurality of cooling channels (210) disposed inside. If reduced cooling is acceptable, the conventional cooling base (130) may be used in the processing chamber (100) instead of the cooling base (126). The conventional cooling base (130) has a top surface, a bottom surface, and an outer periphery (234). The top surface is disposed below the substrate support (174). The bottom surface is disposed on the facility plate (145) of the substrate support assembly (172). The conventional cooling base (130) has a plurality of cooling features, such as a plurality of cooling channels (210).

[0030] A plurality of cooling channels (210) may be formed within the body (230). The cooling channels (210) are configured to transport a cooling fluid through the cooling channels (210). The cooling fluid controls the temperature of the conventional cooling base (130). The cooling channels (210) have a polar array of spirals and extend between an inner ring-shaped channel (214) and an outer ring-shaped channel (212).

[0031] A conventional cooling base (130) has cooling channels (210) spaced apart at equal intervals. The cooling channels (210) may have a spiral shape to allow cooling liquid to flow through the cooling channels (210). The cooling channels (210) have rotational symmetry with respect to each other cooling channels (210) and have a constant pitch. The number of cooling channels (210) is typically made a multiple of 3 to simplify the accommodation of three lift pins between the cooling channels (210). Each cooling channel (210) is terminated by an inlet and an outlet hole and is divided into several parts.

[0032] A fluid flows through a first cooling channel (200) to control the temperature of a conventional cooling base (130). Features disclosed in relation to the discussion of the first cooling channel (200) may also be found in each of the other cooling channels (222). Thus, unless otherwise indicated, each cooling channel (210) is substantially similar to the first cooling channel (200).

[0033] The first cooling channel (200) may have an inlet (240) and an outlet (280). The inlet (240) is configured to provide cooling fluid into the first cooling channel (200). The inlet (240) may be fluidically connected to an external cooling fluid source, such as the heat transfer fluid source (122) depicted in FIG. 1. The cooling fluid flows through the first cooling channel (200) from the inlet (240) to the outlet (280). As heat is transferred from the conventional cooling base (130) to the cooling fluid, the temperature of the fluid may increase from the inlet (240) to the outlet (280). The outlet (280) receives the cooling fluid from the first cooling channel (200). The heat transfer fluid flows through the first cooling channel (200) to control the temperature of the conventional cooling base (130). The heat transfer fluid exits the first cooling channel (200) at the outlet (280).

[0034] The first cooling channel (200) has a generally spiral geometry that wraps around an inner ring-shaped channel (214) located at the center of the conventional cooling base (130), and as the first cooling channel (200) revolves around the inner ring-shaped channel (214), individual segments gradually move further away from or closer to the inner ring-shaped channel (214). In the conventional cooling base (130), the cooling fluid entering from the inlet (240) travels a long distance along each cooling channel (210) before exiting through the outlet (280), which leads to temperature uniformity problems as the cooling fluid temperature increases from the inlet (240) to the outlet (280). Compared to the conventional cooling base (130), the cooling base (126) has a shorter path along each cooling channel.

[0035] FIGS. 3a and 3b are isometric cross-sectional views of a suitable improved cooling base (126). As discussed above, the cooling base (126) has shortened cooling paths within the high-temperature region of the cooling base (126) adjacent to the substrate support (174), made possible by a plenum design for individually distributing cooling fluid. Shorter cooling paths within the high-temperature region reduce temperature variation of the cooling fluid along the cooling paths, thereby better maintaining temperature uniformity of the substrate support (174). The cooling base (126) relies on a plenum-type configuration that provides improved thermal uniformity. In this configuration, the cooling base (126) is made of multiple plates to facilitate multiple cooling fluid inflows along the top surface and an immediate discharge path of the cooling fluid from the top surface to shorten the cooling fluid time in the high-temperature zone adjacent to the substrate support (174), i.e., the top surface. The travel distance of the fluid in the high-temperature zone is minimized to maintain cooling efficiency throughout the cooling area. This ensures that heat removal in different regions of the high-temperature zone is substantially the same, and provides improved thermal uniformity to the substrate support (174) placed on the cooling base (126).

[0036] The cooling base (126) has a top plate (310) and a bottom plate (340). The top plate (310) is configured to be positioned near the substrate support (174). The cooling base (126) has one or more intermediate plates. A first intermediate plate (320) is positioned near the top plate (310) and below the top plate (310). A second intermediate plate (330) is positioned between the first intermediate plate (320) and the bottom plate (340). The bottom plate (340) and the second intermediate plate (330) are considered to be formed of one or more layers.

[0037] In the discussion below, the cooling base (126) will be discussed further in relation to FIGS. 4 and FIGS. 5. FIGS. 4 is a side view of the cooling base (126). FIGS. 5 is a top view of an intermediate plate within the cooling base, exposing all of the cooling inlet holes and outlet holes.

[0038] The top plate (310) has a top surface (301) and a bottom surface (302). The top surface (301) faces the bottom surface (302). Lift pin holes (391) are positioned through the top surface (301) and extend through the bottom surface (302). As illustrated in FIG. 4, the top plate (310) may optionally have an outer flange (311). The outer flange (311) may extend below the bottom surface (302). Alternatively, the top plate (310) does not have an outer flange (311) extending below the bottom surface (302). That is, the bottom surface (302) of the top plate (310) is the lowest surface of the top plate (310).

[0039] The top plate (310) has cooling channels (350) that are open to the bottom surface (302) of the top plate (310). The outer flange (311), if present, extends beyond the bottom surface (302) and below the bottom surface (302). The cooling channels (350) are configured to prevent cooling fluid from flowing from the center of the top plate (310) to the edge. The cooling channels (350) are configured to retain cooling fluid within the top plate for a minimum duration and length. Thus, cooling fluid flowing into the cooling channels (350) immediately exits from the same cooling channels to maintain cooling efficiency throughout the top plate (310).

[0040] Cooling channels (350) may be paired into concentric rings or zones (380). For example, a fifth cooling channel zone (385) may have a first channel (388) and a second channel (389). Coolant is supplied to the fifth cooling channel zone (385) through the first channel (388), and the coolant exits the fifth cooling channel zone (385) through the second channel (389). The first channel (388) and the second channel (389) are located immediately adjacent to each other to minimize the exposure of the coolant heat from the top plate (310). In one example, the second channel (389) is positioned immediately outside the first channel (388). In another example, the first channel (388) is positioned immediately outside the second channel (389). Alternatively, the second channel (389) and the first channel (388) may be radially adjacent. The fourth cooling channel zone (384) is fluidically isolated from the fifth cooling channel zone (385). Likewise, the first cooling channel (381), the second cooling channel zone (382), and the third cooling channel zone (383) are fluidly isolated from each other and from both the fifth cooling channel zone (385) and the fourth cooling channel zone (384). Although five cooling channel zones are described, the top plate (310) may have any number of zones, including three concentric zones. Additionally, it should be noted that the cooling channel zones may be further subdivided into multiple sub-zones. For example, the fifth cooling channel may have 10 sub-zones.

[0041] The first intermediate plate (320) has an upper surface (321) and a lower surface (322) facing the upper surface (321). The upper surface (321) is configured to contact the lowest surface (302) of the top plate (310). The first intermediate plate (320) has an outer edge (323). In one example, the outer edge (323) is adjacent to the outer flange (311) of the top plate (310). The outer flange (311) of the top plate (310) extends downward and has a lowest portion that is coplanar with the lower surface (322) of the first intermediate plate (320). In another example, the outer edge (323) of the first intermediate plate (320) extends to the outer periphery of the cooling base (126).

[0042] As additionally illustrated in FIG. 5, the upper first intermediate plate (320) has a plurality of fluid inlets (342) and fluid outlets (348). The fluid inlets (342) are configured to provide cooling fluid into the cooling channels (350) of the uppermost plate (310). The fluid outlets (348) are configured to drain the cooling fluid from the cooling channels (350). Each fluid inlet (342) is considered to have a one-to-one relationship with each individual fluid outlet (348). In this way, the flow of cooling fluid into the cooling channels (350) is not obstructed by either the fluid inlets (342) or the fluid outlets (348). In one example, among the cooling channels (350) arranged within the fifth channel zone (385), the fifth channel has three or more fluid inlets (342) and fluid outlets (348). That is, a single cooling channel among the cooling channels (350) may have more than one fluid inlet (342) and more than one equal number of fluid outlets (348). The fluid inlets (342) and fluid outlets (348) for each cooling zone are balanced to accommodate the same flow. Alternatively, the cooling zones may have subzones each comprising a single cooling channel (350) having a single fluid inlet (342) coupled to an individual fluid outlet (348). In this way, the cooling fluid flowing into and into the cooling channel (350) can better maintain a constant temperature across the top surface (301) of the top plate (310).

[0043] The second intermediate plate (330) has a top surface (331) and a bottom surface (332). The second intermediate plate (330) has an intermediate layer (337) disposed between the bottom surface (332) and the top surface (331). The second intermediate plate (330) has a plurality of islands (338) extending upward from the intermediate layer (337). The islands (338) have a top (339). The top (339) of the islands coincides with the top surface (331) of the second intermediate plate (330). Each of the plurality of islands (338) has an individual inlet port (462) disposed through the island from the top surface (331). The inlet port (462) is configured to be aligned with the fluid inlet (342) of the first intermediate plate (320). That is, the inlet port (462) is fluidically coupled to the fluid inlet (342). In this way, the cooling fluid travels only through the inlet port (462) of the second intermediate plate (330) and the fluid inlet (342) of the first intermediate plate (320) to supply cooling fluid to the top plate (310).

[0044] The islands (338) form a return plenum (460) within the second intermediate plate (330). The return plenum (460) is formed between the middle layer (337) of the second intermediate plate (330), the sides of the islands (338), and the lower surface (322) of the first intermediate plate (320). The return plenum (460) is fluidically coupled to the fluid outlets (348). The return plenum (460) collects spent cooling fluid returning from the cooling channels (350) within the top plate (310) through the fluid outlets within the first intermediate plate (320).

[0045] The supply plenum (480) is positioned below the return plenum (460) on the second intermediate plate (330). The supply plenum (480) is formed between the intermediate layer (337) and the top surface (341) of the bottom plate (340). The supply plenum (480) is fluidically coupled to inlet ports (462) positioned within a plurality of islands (338). The supply plenum (480) is configured to supply cooling fluid into the cooling channels (350) through the inlet ports (462) and fluid inlets (342) to regulate the temperature of the top plate (310). The intermediate layer (337) may be formed of a thermal insulating material to mitigate heat transfer between the supply plenum (480) and the return plenum (460). Alternatively, the supply plenum (480) and the return plenum (460) may be reversed. For example, the supply plenum can be located in item (460), and the return plenum can be located in item (480).

[0046] The supply plenum (480) enables a cooling fluid at a constant temperature to be supplied across the top plate (310). The return plenum (460) ensures that the used cooling fluid is quickly removed for increased thermal uniformity of the top plate (310). The second intermediate plate (330), coupled with the first intermediate plate (320), allows the cooling fluid to have a minimum amount of time within the top plate (310).

[0047] The bottom plate (340) has a bottom surface (343) facing the top surface (341). The top surface (341) supports the second intermediate plate (330) of the cooling base (126). The bottom surface (343) is the bottom surface (302) of the cooling base (126). A coolant supply channel (373) is provided through the bottom plate (340). The coolant supply channel (373) fluidically couples the supply plenum (480) to a coolant supply source (370), such as a heat transfer fluid source (122). In one example, as shown in FIG. 3b, the bottom plate (340) has a plurality of coolant supply channels (373) arranged radially around the center of the bottom plate (340).

[0048] A coolant return channel (393) is provided through the bottom plate (340). The coolant return channel (393) is fluidically coupled to a return plenum (460) through a return passage (392) disposed within the bottom plate (340). The coolant return channel (393) couples the return passage (392) to a coolant heat exchanger (390) outside the bottom plate (340), or conversely, to a coolant supply source (370). In one example, as shown in FIG. 3b, the bottom plate (340) has a plurality of coolant return channels (393) arranged radially around the center of the bottom plate (340). In one example, the coolant return channels (393) are disposed outside the coolant supply channels (373). In other words, the coolant return channels (393) surround the coolant supply channels (373).

[0049] The coolant structure described for the cooling base (126) improves the temperature uniformity of the substrate support assembly (172) during operation. The cooling base (126) has a cooling zone within the top plate (310) adjacent to the substrate support (174). The cooling base is configured to have cooling channels (350) having one or more fluid inlets (342) and fluid outlets (348). The fluid inlets (342) and fluid outlets (348) provide coolant flow to different zones fluidly isolated from the cooling channels (350). The cooling base (126) provides an immediate discharge path for the cooling fluid at the fluid outlets (348) to shorten the time and cooling fluid path within the high-temperature zone of the cooling base (126) adjacent to the substrate support (174). The shortened cooling fluid path provides an improved cooling capacity throughout the cooling zone of the high-temperature zone. The travel distance for the cooling fluid within the cooling channels (350) is short, which maintains the same cooling efficiency across the entire top surface (301) of the top plate (310).

[0050] FIG. 6 illustrates a method (600) for cooling a substrate support using the cooling base of FIG. 3a and FIG. 3b. The method (600) begins in operation (610), where a cooling fluid flows into a cooling fluid inlet plenum disposed within the middle plate of the cooling base. In operation (620), the cooling fluid flows from the cooling fluid inlet plenum into one of a plurality of cooling channels within the top plate of the cooling base. The cooling channel has a cooling fluid inlet and a cooling fluid outlet. In one example, the cooling fluid channel has three or more cooling fluid inlets and individual cooling fluid outlets. In operation (630), the cooling fluid from the cooling channel flows into a cooling fluid return plenum through a cooling fluid outlet. The cooling fluid return plenum is disposed within the cooling base in a manner adjacent to and perpendicular to the cooling fluid supply plenum. The cooling fluid return plenum has a plurality of islands, through which the cooling fluid is supplied to the cooling channel.

[0051] Advantageously, shortened cooling channels within the top plate, coupled to the supply plenum and return plenum below the top plate, enable improved temperature control and uniformity along the top surface of the cooling plate.

[0052] Although the foregoing relates to specific embodiments, other and additional embodiments may be devised without departing from the basic scope of the present disclosure, and the scope of the present disclosure is determined by the subsequent claims.

Claims

Claim 1 As a cooling base, an upper plate having cooling channels formed internally; an intermediate plate disposed below the upper plate ― the intermediate plate is: A cooling return plenum placed on an intermediate layer; A cooling supply plenum positioned below the above intermediate layer; A plurality of islands disposed within the cooling return plenum on the above intermediate layer; A plurality of cooling inlets disposed through the plurality of islands and coupling the cooling supply plenum to the cooling channels; and A cooling base comprising: a plurality of cooling outlets fluidically coupled to the cooling channels to the cooling return plenum; and a bottom plate disposed below the intermediate plate, wherein the bottom plate has cooling inlets fluidly coupled to the cooling supply plenum and cooling outlets fluidly coupled to the cooling return plenum. Claim 2 In claim 1, the uppermost plate further comprises a plurality of zones in which the cooling channels are arranged, each zone being fluidly isolated from all other zones and fluidly coupled to two or more of the plurality of cooling inlets, a cooling base. Claim 3 In paragraph 2, each zone is a cooling base fluidly coupled to two or more of the plurality of cooling outlets. Claim 4 In paragraph 3, the plurality of zones are concentric with each other, forming a cooling base. Claim 5 In paragraph 3, the cooling base, wherein the first number of cooling outlets in the first zone is less than the second number of cooling outlets in the second zone. Claim 6 A cooling base according to claim 1, further comprising a first insert disposed within one or more of the plurality of cooling inlets, wherein the first insert determines fluid flow through the cooling inlets. Claim 7 A cooling base according to claim 1, further comprising a second insert disposed within one or more of the plurality of cooling outlets, wherein the second insert determines fluid flow through the cooling inlet. Claim 8 In paragraph 2, the first fluid inlets disposed within the first zone among the plurality of zones have a first opening size through which fluid flows, and the first opening size is different from the second fluid inlets disposed within the second zone among the plurality of zones, a cooling base. Claim 9 In paragraph 2, the cooling base, wherein the cooling fluid flow through the first zone among the plurality of zones is different from the cooling fluid flow through the second zone among the plurality of zones. Claim 10 A substrate support assembly comprises: a substrate support; and a cooling base coupled to the substrate support, wherein the cooling base comprises: a top plate having cooling channels formed internally; and an intermediate plate disposed below the top plate ― the intermediate plate comprises: Cooling return plenum placed on an intermediate layer; A cooling supply plenum positioned below the above intermediate layer; A plurality of islands disposed within the cooling return plenum on the above intermediate layer; A plurality of cooling inlets disposed through the plurality of islands and coupling the cooling supply plenum to the cooling channels; and A substrate support assembly comprising: a plurality of cooling outlets fluidically coupled to the cooling channels to the cooling return plenum; and a bottom plate disposed below the intermediate plate, wherein the bottom plate has cooling inlets fluidly coupled to the cooling supply plenum and cooling outlets fluidly coupled to the cooling return plenum. Claim 11 In claim 10, the uppermost plate further comprises a plurality of zones in which the cooling channels are arranged, each zone being fluidly isolated from all other zones and fluidly coupled to two or more of the plurality of cooling inlets, a substrate support assembly. Claim 12 In claim 11, each zone is fluidly coupled to two or more of the plurality of cooling outlets, forming a substrate support assembly. Claim 13 In Clause 12, the plurality of zones are concentric with each other, forming a substrate support assembly. Claim 14 In paragraph 13, the substrate support assembly, wherein the first number of cooling outlets in the first zone is less than the second number of cooling outlets in the second zone. Claim 15 A substrate support assembly according to claim 10, further comprising a first insert disposed within one or more of the plurality of cooling inlets, wherein the first insert determines fluid flow through the cooling inlets. Claim 16 A substrate support assembly according to claim 10, further comprising a second insert disposed within one or more of the plurality of cooling outlets, wherein the second insert determines fluid flow through the cooling inlet. Claim 17 A substrate support assembly according to claim 11, wherein first fluid inlets disposed within the first zone among the plurality of zones have a first opening size through which fluid flows, and the first opening size is different from the second fluid inlets disposed within the second zone among the plurality of zones. Claim 18 A substrate support assembly according to claim 11, wherein the cooling fluid flow through the first zone among the plurality of zones is different from the cooling fluid flow through the second zone among the plurality of zones. Claim 19 A method for controlling the temperature of a substrate support disposed on a cooling base, comprising: flowing a cooling fluid into a cooling fluid supply plenum disposed within an intermediate plate of the cooling base; flowing the cooling fluid from the cooling fluid supply plenum into one of a plurality of cooling channels within an uppermost plate of the cooling base; and flowing the cooling fluid from the cooling channel into a cooling fluid return plenum disposed within the intermediate plate through a cooling fluid outlet, wherein the cooling fluid return plenum is vertically adjacent to the cooling fluid supply plenum. Claim 20 A method according to claim 19, wherein the cooling channels have three or more cooling fluid inlets and individual cooling fluid outlets, and the cooling fluid return plenum is disposed within the cooling base in a state adjacent to the cooling fluid supply plenum perpendicularly.

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