Improving the vacuum seal integrity of cryogenic electrostatic chucks using a non-contact surface temperature measurement probe

Abstract

The present disclosure relates to an apparatus for measuring the temperature of a substrate support assembly and a substrate disposed on the support assembly. In one embodiment, the substrate temperature measurement apparatus includes a substrate support assembly, a probe assembly, and a probe target. The substrate support assembly includes an electrostatic chuck and one or more plates. A probe assembly in the substrate support assembly extends through one or more of the one or more plates. The probe assembly includes an optical probe sensor, an optical fiber coupled to the optical probe sensor, and an insulating sheath surrounding the optical fiber. The probe target includes a phosphor coating and is in contact with the electrostatic chuck and spaced apart from the probe assembly.

Description

[Technical Field]

[0001]

[0001] Embodiments of the present disclosure relate generally to apparatus used to measure operating conditions inside a semiconductor substrate processing chamber, and more particularly to an apparatus for measuring substrate temperature by detecting optical emissions from module components. [Background technology]

[0002]

[0002] The materials and processes used to process semiconductor substrates in semiconductor processing systems are highly sensitive to temperature changes. When these materials are exposed to excessive temperatures or gradients caused by insufficient thermal stabilization or conduction, the yield or performance of the final product is compromised. For example, if process temperatures are not properly controlled, processes such as etch selectivity and deposition reactions can be compromised, resulting in reduced process uniformity. This can result in incomplete fabrication of circuits formed on semiconductor substrates and / or unacceptable device-to-device variations.

[0003]

[0003] The substrate support, or pedestal, residing within a semiconductor processing chamber is in intimate contact with the substrate and serves as both a heat sink and a substrate support. Most pedestals are cooled by thermal conduction to a liquid-cooled base, where a constant flow of coolant removes excess heat. It has been shown that measuring the temperature of the pedestal can provide an indication of the substrate temperature. One method for determining pedestal temperature is to measure the temperature of the coolant at the base outlet. Unfortunately, this method is limited in that the measured temperature is neither an accurate nor a timely measure of the pedestal temperature. For example, the coolant temperature in the base is measured after the coolant has passed through several interfaces, conduits, and heat sinks. The use of such unreliable, delayed data (i.e., as a parameter in a temperature control feedback system) makes stabilizing the substrate temperature difficult.

[0004]

[0004] Another technique is diffuse reflectance spectroscopy. Wavelengths of light reflected from the substrate surface are selected for monitoring. A spectrometer measures the level of backscattering at the selected wavelengths (a temperature characteristic associated with a specific energy) to derive the substrate temperature. However, this method is susceptible to erroneous readings from energy received from other "hot" surfaces in close proximity to the measurement instrument.

[0005] Yet another technique attempts to directly measure the pedestal temperature during substrate processing by placing a thermocouple probe in contact with the pedestal. However, thermocouple probes placed in direct contact with the pedestal can be subject to radio frequency (RF) interference from the plasma used in substrate processing, leading to inaccurate temperature measurements. Furthermore, the increased complexity of the pedestal is an undesirable consequence of using thermocouples. Moving the thermocouple in and out of contact with the pedestal creates the need for sealing in both atmospheric and vacuum environments. Furthermore, leaks due to imperfect sealing around the thermocouple can lead to contamination and other adverse effects during substrate processing. Thermocouple probes are also cumbersome to attach and secure to the pedestal. For example, they require the creation of a small, narrow bore in the pedestal, which is difficult to manufacture. Furthermore, because the thermocouple is typically cemented or otherwise affixed to the pedestal at the bottom of the bore, replacing the thermocouple requires extensive rework and downtime.

[0006] Therefore, there is a need in the art for an apparatus that can provide accurate real-time measurements of pedestal temperature. Summary of the Invention

[0007] The present disclosure generally relates to a substrate support assembly and an apparatus for measuring the temperature of a substrate disposed on the support assembly. In one embodiment, a substrate temperature measurement apparatus includes a substrate support assembly, a probe assembly, and a probe target. The substrate support assembly includes an electrostatic chuck and one or more plates. A probe assembly in the substrate support assembly extends through one or more of the one or more plates. The probe assembly includes an optical probe sensor, an optical fiber coupled to the optical probe sensor, and an insulating sheath surrounding the optical fiber. The probe target includes a phosphor coating and is in contact with the electrostatic chuck and spaced apart from the probe assembly.

[0008] In another embodiment, a substrate support assembly includes an electrostatic chuck, one or more plates, and a probe assembly. The probe assembly is within the electrostatic chuck and extends through the one or more plates within the electrostatic chuck. The probe assembly includes an optical probe sensor, an optical fiber coupled to the optical probe sensor, and an insulating sheath surrounding the optical fiber. The substrate support assembly also includes a probe target having a phosphor coating, the probe target contacting the electrostatic chuck and spaced apart from the probe assembly.

[0009] In another embodiment, a substrate support assembly includes an electrostatic chuck having one or more plates and a probe assembly. The probe assembly is within the electrostatic chuck and extends through one or more plates within the electrostatic chuck. The probe assembly includes an optical probe sensor, an optical fiber coupled to the optical probe sensor, an insulating sheath surrounding the optical fiber, and a housing. The housing is within the electrostatic chuck, the housing including a cavity and a seal. The seal is disposed within a seal recess in the housing. The optical fiber and insulating sheath extend through the cavity and are surrounded by a sealing agent within the cavity. The substrate support assembly also includes a probe target having a phosphor coating, the probe target contacting the electrostatic chuck and spaced apart from the probe assembly.

[0010]

[0010] In order that the above-described features of the present disclosure may be understood in detail, the above-summarized disclosure will be more particularly described by reference to embodiments, some of which are illustrated in the accompanying drawings. It should be noted, however, that the accompanying drawings depict only exemplary embodiments and therefore should not be considered as limiting the scope of the present disclosure, which may also admit of other equally effective embodiments. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic cross-sectional view of a plasma processing chamber according to an embodiment of the present disclosure. [Figure 2A] 1 is a schematic partial cross-sectional view of a probe assembly and a cryogenic pedestal according to an embodiment of the present disclosure. [Figure 2B] FIG. 2B is a detailed schematic cross-sectional view of the probe target shown in FIG. 2A according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0012]

[0014] To facilitate understanding, wherever possible, the same reference numerals have been used to designate identical elements common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.

[0013]

[0015] The embodiments described herein provide a substrate support assembly that allows for temperature measurement of a substrate at temperatures below about -20°C or above about 300°C during substrate processing.

[0014]

[0016] Although the substrate support assembly is described below in an etch processing chamber, the substrate support assembly can be utilized in other types of processing chambers, such as physical vapor deposition chambers, chemical vapor deposition chambers, plasma-enhanced chemical vapor deposition chambers, ion implantation chambers, and other systems where processing requires the substrate to be maintained at temperatures below about −20° C. or above about 300° C. The substrate support assemblies disclosed herein can also be utilized at temperatures from −20° C. to 300° C.

[0015]

[0017] FIG. 1 is a schematic cross-sectional view of an exemplary plasma processing chamber 100 configured as an etch chamber having a substrate support assembly 101. The substrate support assembly 101 can be utilized in other types of processing chambers, such as plasma processing chambers, annealing chambers, physical vapor deposition chambers, chemical vapor deposition chambers, and ion implantation chambers, as well as other systems in which the ability to uniformly maintain a surface or workpiece, such as a substrate 124, at a temperature below approximately −20° C. is desirable. Dry reactive ion etching of a substrate 124 maintained at temperatures below −20° C. or above 300° C. can be performed to bombard the upward-facing surface of a material disposed on the substrate 124 with ions, resulting in the formation of trenches with smooth, vertical sidewalls while reducing spontaneous etching. One of the many advantages of these techniques includes improved etch selectivity of one material over another at temperatures below −20° C. For example, selectivity between silicon (Si) and silicon dioxide (SiO) increases exponentially as temperature decreases.

[0016]

[0018] The plasma processing chamber 100 includes a chamber body 102 having a sidewall 104, a bottom 106, and a lid 108 that surround a process region 110. An injector 112 is coupled to the sidewall 104 and / or the lid 108 of the chamber body 102. A gas panel 114 is coupled to the injector 112 and enables delivery of process gases into the process region 110. The injector 112 may be one or more nozzles or inlet ports, or a showerhead. The process gases, along with any processing by-products, are removed from the process region 110 through exhaust ports 116 formed in the sidewall 104 or bottom 106 of the chamber body 102. The exhaust ports 116 are coupled to a pumping system 140, which includes a throttle valve and a pump that are utilized to control the vacuum level within the process region 110.

[0017]

[0019] A voltage is applied to the process gas to form a plasma in the process region 110. In one embodiment, the process gas is energized by capacitively or inductively coupling RF power to the process gas. In this embodiment, which can be combined with other embodiments described herein, shown in FIG. 1 , a plurality of coils 118 are positioned above the lid 108 of the plasma processing chamber 100 and are coupled to an RF power source 122 through a matching network 120.

[0018]

[0020] The substrate support assembly 101 is positioned in a process region 110 below the implanter 112. The substrate support assembly 101 includes an electrostatic chuck (ESC) 103 and an ESC base assembly 105. The ESC base assembly 105 is coupled to the ESC 103 and an equipment plate 107. The equipment plate 107 is supported by a ground plate 111 and configured to facilitate electrical, cooling, heating, and gas connections to the substrate support assembly 101. The ground plate 111 is supported by the bottom 106 of the processing chamber. An insulator plate 109 insulates the equipment plate 107 from the ground plate 111. In some embodiments, the process region 110 is under vacuum during process operation. The internal connections of the substrate support assembly 101 include seals to prevent leakage through the substrate support assembly 101 into the process region 110. In some embodiments, the process region 110 is defined in part by the connections in the insulator plate 109.

[0019]

[0021] In one embodiment, the bottom surface 132 of the ESC 103 is coupled to the ESC base assembly 105. In one embodiment, the ESC base assembly 105 comprises a molybdenum alloy or similar material and may be attached to the ESC 103 with an elastomeric material or other suitable bonding material. A mechanical connection may also be used to attach the ESC base assembly 105 to the ESC 103. The bottom surface 210 (FIG. 2A) of the ESC base assembly 105 is positioned in contact with the equipment plate 107. The equipment plate 107 is positioned between the ESC base assembly 105 and the insulator plate 109. The insulator plate 109 is positioned below the equipment plate 107, opposite the ESC 103.

[0020]

[0022] The ESC base assembly 105 includes a base channel 115 coupled to a cryogenic chiller 117. The cryogenic chiller 117 is fluidly connected to the base channel 115 via a base inlet conduit 123 connected to the inlet of the base channel 115 and via a base outlet conduit 125 connected to the outlet of the base channel 115 so that the ESC base assembly 105 is maintained at a temperature below −20° C. The cryogenic chiller 117 is coupled to an interface box for controlling the flow rate of a base fluid. The base fluid may include a material capable of maintaining a temperature below −50° C. The cryogenic chiller 117 supplies a base fluid that is circulated through the base channel 115 of the ESC base assembly 105. The base fluid flowing through the base channel 115 enables the ESC base assembly 105 to be maintained at a temperature below −20° C., which helps control the lateral temperature profile of the ESC 103 so that a substrate 124 disposed on the ESC 103 is uniformly maintained at a temperature below −20° C. In one embodiment, which may be combined with other embodiments described herein, the cryogenic chiller 117 is a single-stage chiller operable to maintain the base fluid at a temperature below approximately −50 degrees C. In another embodiment, which may be combined with other embodiments described herein, the cryogenic chiller 117 is a chiller that utilizes a refrigerant within the chiller to maintain the base fluid at a temperature below −50 degrees C.

[0021]

[0023] The equipment plate 107 includes equipment channels 234 coupled to a cooling device 119. The cooling device 119 is fluidly connected to the equipment plate 107 via an equipment inlet conduit 127 and an equipment outlet conduit 129 so that the equipment plate 107 is maintained at a predetermined ambient temperature. The cryogenic cooling device 119 is coupled to an interface box for controlling the flow rate of equipment fluid. The equipment fluid may include a material capable of maintaining an ambient temperature of approximately -10°C to approximately 60°C. The cooling device 119 supplies equipment fluid that is circulated through the equipment plate 107. The equipment fluid enables the equipment plate 107 to be maintained at a predetermined ambient temperature and helps maintain the insulator plate 109 at a predetermined ambient temperature.

[0022]

[0024] ESC 103 has a support surface 130 and a bottom surface 132 opposite support surface 130. In one embodiment, which can be combined with other embodiments described herein, ESC 103 is made from a ceramic material such as alumina (Al2O3), aluminum nitride (AlN), or other suitable material. Alternatively, ESC 103 can be made from a polymer, such as polyimide, polyetheretherketone, polyaryletherketone, or the like.

[0023]

[0025] The ESC 103 includes a chuck electrode 126 disposed therein. The chuck electrode 126 may be configured as a monopolar electrode, a bipolar electrode, or any other suitable arrangement. The chuck electrode 126 is coupled through an RF filter and a fixture plate 107 to a chuck power supply 134, which provides DC power for electrostatically clamping the substrate 124 to a support surface 130 of the ESC 103. The RF filter prevents the RF power utilized to form a plasma (not shown) within the plasma processing chamber 100 from damaging electrical equipment or posing an electrical hazard outside the chamber.

[0024]

[0026] The ESC 103 includes one or more resistive heaters 128 embedded therein. The resistive heaters 128 are utilized to raise the temperature of the ESC 103 as needed to a temperature suitable for processing a substrate 124 disposed on the support surface 130. The resistive heaters 128 are coupled to a heater power supply 136 through a fixture plate 107 and an RF filter. The RF filter prevents the RF power utilized to form a plasma (not shown) within the plasma processing chamber 100 from damaging electrical equipment or posing an electrical hazard outside the chamber. The heater power supply 136 is capable of providing 500 watts or more of power to the resistive heater 128. The heater power supply 136 includes a controller (not shown) utilized to control the operation of the heater power supply 136 and is generally configured to heat the substrate 124 as needed to maintain the substrate temperature at a desired temperature, e.g., below approximately −20° C. Stated another way, heat from the resistive heater 128 and cooling from the base fluid circulating through the ESC base assembly 105 are balanced to maintain the substrate 124 at a desired temperature of −20° C. or below. In one embodiment, the ESC base assembly 105 includes two internal bases (shown in FIG. 2A ). For example, the resistive heater 128 and the base fluid circulating through the ESC base assembly 105 maintain the substrate 124 at a temperature suitable for processing below about −20° C., such as from about −20° C. to about −150° C. In another embodiment, the resistive heater 128 is utilized to maintain the substrate 124 at an elevated temperature, such as above about 300° C.

[0025]

[0027] The resistive heater 128 includes multiple laterally separated heating zones, and the controller enables at least one zone of the resistive heater 128 to be preferentially heated relative to resistive heaters 128 located in one or more of the other zones. For example, the resistive heater 128 may be concentrically arranged into multiple separated heating zones. The separated heating zones of the resistive heater 128 aid in controlling temperature uniformity from the lateral edge to the center of the substrate 124.

[0026]

[0028] The substrate support assembly 101 may include one or more probes disposed therein. The ESC 103 is coupled to a probe controller 138. A probe tip 222 (shown in FIG. 2B ) in communication with the probe controller 138 is disposed on or adjacent to the surface of the ESC 103 within the base assembly 105 to determine the temperature of the ESC 103. Thus, the probe tip 222 in communication with the probe controller 138 can be used to calibrate the temperature of the substrate 124 based on the temperature of the ESC base assembly 105. The probe controller 138 is communicatively coupled to the heater power supply 136 so that each zone of the resistive heater 128 is independently heated, the lateral temperature profile of the ESC 103 is substantially uniform based on the temperature measurements, and the substrate 124 disposed on the ESC 103 is uniformly maintained at a temperature below −20° C.

[0027]

[0029] The probe controller 138 includes a programmable central processing unit (CPU) operable with memory (e.g., non-volatile memory) and support circuitry. The support circuitry is conventionally coupled to the CPU and includes cache, clock circuits, input / output subsystems, power supplies, etc., and combinations thereof coupled to various components of the chamber 100 to facilitate their control. The CPU may be any form of general-purpose computer processor used in industrial environments, such as a programmable logic controller (PLC), to control various components and sub-processors of a processing system. The memory coupled to the CPU is non-transitory and is typically one or more of readily available memory, such as random access memory (RAM), read-only memory (ROM), a floppy disk drive, a hard disk, or other form of local or remote digital storage.

[0028]

[0030] Typically, the memory is in the form of a non-transitory computer-readable storage medium (e.g., non-volatile memory) containing instructions that, when executed by a CPU, facilitate operation of the chamber 100. The instructions in the memory are in the form of a program product, such as a program that performs the methods of the present disclosure. The program code may conform to any one of a number of different programming languages. In one example, the present disclosure may be implemented as a program product stored on a computer-readable storage medium for use with a computer system. The program(s) in the program product define functions of the embodiments (including the methods described herein).

[0029]

[0031] Exemplary non-transitory computer-readable storage media include, but are not limited to, (i) non-writable storage media on which information may be permanently stored (e.g., a CD-ROM disk readable by a CD-ROM drive, a flash memory, a ROM chip, or any type of solid-state non-volatile semiconductor memory device, e.g., a read-only memory device in a computer such as a solid-state drive (SSD)), and (ii) writable storage media on which changeable information may be stored (e.g., a floppy disk in a diskette drive or hard disk drive, or any type of solid-state random-access semiconductor memory). Such computer-readable storage media, when carrying computer-readable instructions that direct the functions of the methods described herein, are embodiments of the present disclosure. In some embodiments, the methods described herein, or portions thereof, are performed by one or more application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other types of hardware implementations. In some other embodiments, the substrate processing and / or handling methods described herein are performed by a combination of software routines, ASIC(s), FPGAs, and / or other types of hardware implementations. One or more system controllers 138 may be used with one or any combination of the various systems described herein.

[0030]

[0032] 2A is a schematic, partial cross-sectional, enlarged view showing support assembly 101 from box 2A of FIG. 1. Support assembly 101 includes probe assembly 200, which is disposed within a cavity in support assembly 101 and allows components of probe assembly 200 to monitor the temperature of ESC 103. Probe assembly 200 is disposed within bore tube 223 and lower cavity 213. Bore tube 223 is a cavity in ESC base assembly 105 and equipment plate 107. Lower cavity 213 is a cavity connected to bore tube 223. Lower cavity 213 is disposed within equipment plate 107 and insulator plate 109. In some embodiments, bore tube 223 is a cylindrical cavity that expands into lower cavity 213 in equipment plate 107.

[0031]

[0033] The probe assembly 200 is configured to allow measurement of temperatures below about 10° C. For example, the probe assembly 200 can measure temperatures from about 100° C. to about −50° C.

[0032]

[0034] The probe assembly 200 includes a target 206 (FIG. 2B) disposed at a first end 201 of the probe assembly, an optical fiber 221, an optical sheath 225 disposed radially outward from the optical fiber 221, a housing 212, and a housing seal 202. The target 206 is disposed in contact with the bottom surface 132 of the ESC 103. The optical fiber 221 passes from the first end 201 through the ESC base assembly 105 and the equipment plate 107 to a second end 203 of the probe assembly 200. The second end 203 of the probe assembly 200 is disposed within the insulator plate 109. In some embodiments, the probe assembly 200 also includes an optical sensor (not shown) capable of reading a signal to determine at least a temperature. The probe assembly 200 is connected to the probe controller 138 (FIG. 1). The probe controller 138 uses the signal to determine the temperature of the ESC 103. The signal includes light transmitted through the optical fiber 221. In some embodiments, an optical sensor (not shown) is in the probe controller 138 and can read the signal to determine the temperature of the ESC 103.

[0033]

[0035] The portion of the probe assembly 200 disposed within the bore tube 223 is the bore 205. The bore 205 is the portion of the optical sheath 225 and optical fiber 221 that extends from the housing 212 to the first end 201 of the probe assembly 200. The probe housing 212 includes the portion of the optical sheath 225 and optical fiber 221 within the lower cavity 213. The probe housing 212 also includes a recess 209 in which a seal 202 is disposed. The recess 209 is a recess in the face of the housing that faces toward the ESC 103. The seal 202 is disposed within the seal recess 209 between the probe housing 212 and the equipment plate 107. The seal 202 separates the process region 110 from the insulator plate 109 and other non-substrate processing regions. The process region 110 includes the portion of the equipment plate 107 and the components included in the ESC base assembly 105 above the insulator plate 109 and the housing 212. Seal 202 is a circular member that surrounds bore 205. Seal 202 is made from an elastomeric material selected to be able to seal at temperatures below about 10°C.

[0034]

[0036] Probe housing 212 is disposed opposite first end 201 of probe assembly 200. Probe housing 212 represents second end 203 of probe assembly 200. Probe housing 212 is fabricated from a metallic material, such as an alloy, and probe housing 212 is disposed within and extends through both facilities plate 107 and insulator plate 109. Probe housing 212 includes a sealant 219 that fills voids 214 within probe housing 212. In one embodiment, sealant 219 is a suitable epoxy or other material that fills voids 214 and does not expand or contract excessively at the temperatures to which support assembly 101 is exposed during processing.

[0035]

[0037] 2B is a detailed schematic cross-sectional view of the probe target 206 of box 2B of FIG. 2A. The probe target 206 is located at the first end 201 of the probe assembly 200. In one embodiment, the probe target 206 is recessed in the ESC base assembly 105. In another embodiment, the probe target 206 is coupled to the ESC 103.

[0036]

[0038] The probe target 206 includes a photoluminescent material 220, a target core 211, and may include a target layer 207. The target layer 207 is disposed in contact with the ESC 103. The target layer 207 has a thickness sufficient to reduce adverse effects of thermal gradients on thermal measurements. The target layer 207 may be an adhesive that transfers thermal energy from the ESC to the target 206. The target layer 207 is disposed between the target core 211 and the ESC 103. In some embodiments, the target core 211 is made of a ceramic material, such as alumina. In other words, the core 211 is a ceramic core. The photoluminescent material 220 is disposed on the opposite side of the target layer 207 and is bonded to the target core 211. Thus, the target core 211 is disposed between the target layer 207 and the photoluminescent material 220. In some embodiments, the target core 211 is a metal alloy infused with the photoluminescent material 220. Although the probe target 206 is shown bound to the surface of the ESC 103, it is envisioned that the probe target 206 may be in a recess within the ESC 103.

[0037]

[0039] In one embodiment, photoluminescent material 220 is a phosphor material having an emission decay rate from an excited state resulting from exposure to light of one or more wavelengths that correlates with the temperature of photoluminescent material 220. For example, photoluminescent material 220 may be made of a phosphor-containing material. Additionally, photoluminescent material 220 may contain a binder that is chemically compatible with photoluminescent material 220 and transparent to wavelengths associated with the excitation and emission of photoluminescent material 220. When photoluminescent material 220 is a layer, the thickness of photoluminescent material 220 is about 0.01 mm to about 0.5 mm, for example, about 0.25 mm. Thus, the thickness of photoluminescent material 220 is selected to reduce the adverse effects of thermal gradients on thermal measurements.

[0038]

[0040] An optical fiber 221 is positioned at a tip 222 of the probe assembly 200. In one embodiment, the optical fiber tip 222 acts as a sensor. The optical fiber tip 222 receives light from a photoluminescent material 220, which enables optical remote temperature sensing. The optical fiber 221 is positioned opposite the probe target 206 having the photoluminescent material 220 disposed thereon and is oriented to face the probe target 206. A gap 224 is present between the temperature probe tip 222 and the photoluminescent material 220. In one embodiment, the gap 224 is a distance of about 0.1 mm to about 10 mm, e.g., about 5 mm. The gap 224 is utilized to mitigate the effects of thermal cycling on the temperature probe tip 222 and to avoid conduction of thermal energy through the bore tube 223.

[0039]

[0041] Bore tube 223 includes optical sheath 225 and optical fiber 221. Optical sheath 225 is disposed between the inside of bore 205 and the outside of optical fiber 221, with coating 217 between optical fiber 221 and optical sheath 225. Optical sheath 225 is made of a thermally insulating material and / or an electrically insulating material, and / or a cladding material, etc. Optical fiber 221 is made of a material that is optically transparent, such as quartz. Coating 217 is a sealant that can seal bore tube 223 against vacuum at low temperatures.

[0040]

[0042] Embodiments of the present disclosure include a probe assembly that allows for temperature monitoring of the ESC within a chamber under vacuum. Bonding the target to the bottom of the ESC reduces the number of seals that may be required to prevent leaks into the chamber. This is particularly beneficial in cryogenic applications, where smaller seals are more likely to fail at low temperatures. Sealing the process chamber vacuum deep into the substrate support assembly allows for a larger, more robust sealing method, and maintaining the probe target under vacuum improves accuracy. The target's vacuum further minimizes erroneous temperature measurements caused by the transfer of thermal energy between non-processing areas.

[0041]

[0043] While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the present disclosure may be devised without departing from the basic scope thereof as determined by the following claims.

Claims

1. A substrate temperature measurement device, a substrate support assembly including an electrostatic chuck and one or more plates; a probe assembly disposed within the substrate support assembly and extending through one or more of the one or more plates, an optical probe sensor; an optical fiber coupled to the optical probe sensor; an insulating sheath surrounding the optical fiber; a probe assembly including: a probe target in contact with the electrostatic chuck, the probe target including a coating of a photoluminescent material and spaced apart from the probe assembly; A substrate temperature measuring device comprising:

2. The substrate temperature measurement apparatus of claim 1 , wherein the probe assembly further includes a seal disposed on a housing, the housing being disposed within the one or more plates.

3. The substrate temperature measurement apparatus of claim 2 , wherein the seal is disposed around the optical fiber and configured to maintain a vacuum around the electrostatic chuck.

4. 3. The substrate temperature measurement apparatus of claim 2, wherein the housing further comprises a sealant disposed within a void in the housing and surrounding the insulating sheath.

5. The substrate temperature measurement apparatus of claim 1 , wherein the coating is disposed on a core of the probe target.

6. The substrate temperature measurement device of claim 5 , wherein the core comprises a ceramic material.

7. The substrate temperature measurement apparatus of claim 1 , wherein the optical probe sensor is aimed at a coating on the probe target.

8. 2. The substrate temperature measurement apparatus of claim 1, wherein the probe assembly is connected to a probe controller.

9. A substrate support assembly an electrostatic chuck and one or more plates; a probe assembly disposed within the electrostatic chuck, the probe assembly extending through one or more of the one or more plates; an optical probe sensor; an optical fiber coupled to the optical probe sensor; an insulating sheath surrounding the optical fiber; a probe assembly including: a probe target in contact with the electrostatic chuck and spaced from the tip of the optical fiber, the probe target including a coating of a photoluminescent material; A substrate support assembly comprising:

10. The substrate support assembly of claim 9 , wherein the probe target is located on a bottom surface of the electrostatic chuck.

11. The substrate support assembly of claim 9 , wherein the probe target comprises a metal alloy infused with the photoluminescent material.

12. The substrate support assembly of claim 9 , wherein the probe target comprises a ceramic core and a photoluminescent material disposed between the optical fiber and the ceramic core.

13. The substrate support assembly of claim 9 , wherein the optical probe sensor is aimed at a coating on the probe target.

14. The substrate support assembly of claim 9 , wherein the probe assembly is connected to a probe controller.

15. The substrate support assembly of claim 9 , wherein the probe assembly further comprises a housing including a sealant disposed within a void within the housing and surrounding the insulating sheath.

16. The substrate support assembly of claim 15 , wherein the probe assembly further comprises a seal disposed on a housing, the housing being disposed within one or more plates.

17. The substrate support assembly of claim 16 , wherein the seal is disposed around an optical fiber and configured to maintain a vacuum around an electrostatic chuck.

18. A substrate support assembly an electrostatic chuck including one or more plates; a probe assembly disposed within the substrate support assembly and extending through one or more of the one or more plates, an optical probe sensor; an optical fiber coupled to the optical probe sensor; an insulating sheath surrounding the optical fiber; a housing disposed within the electrostatic chuck, a seal disposed in the seal recess of the housing; a cavity within the housing, the optical fiber and the insulating sheath being disposed through the cavity; a sealant disposed within the cavity surrounding the insulating sheath; a housing including a probe assembly including: a probe target in contact with the bottom surface of the electrostatic chuck and spaced apart from the tip of the optical fiber, the probe target including a coating of a photoluminescent material; A substrate support assembly comprising:

19. The substrate support assembly of claim 18 , wherein the probe target comprises a metal alloy infused with the photoluminescent material.

20. The substrate support assembly of claim 18 , wherein the probe target comprises a ceramic core and a photoluminescent material disposed between the optical fiber and the ceramic core.

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