Improved vacuum seal integrity for low temperature electrostatic chuck with non-contact surface temperature measurement probe

Abstract

The invention relates to a substrate support assembly and an apparatus for measuring a temperature of a substrate disposed on the support assembly. In one embodiment, a substrate temperature measurement apparatus includes a substrate support assembly, a detector assembly, and a detector target. The substrate support assembly includes an electrostatic chuck and one or more plates. The detector assembly within the substrate support assembly extends through one or more of the one or more plates. The detector assembly includes: an optical detector sensor; an optical fiber coupled to the optical detector sensor; and an insulating sheath which surrounds the optical fiber. The detector target includes a phosphor coating, in contact with the electrostatic chuck, and spaced apart from the detector assembly.

Description

Technical Field

[0001] Embodiments of the present disclosure relate generally to apparatus for measuring operating conditions inside a semiconductor substrate processing chamber, and more particularly, to apparatus for measuring substrate temperature by detecting light emissions from modular components. Background Art

[0002] The materials and processes used to process semiconductor substrates in semiconductor processing systems are highly sensitive to temperature changes. If these materials are exposed to excessive temperatures or gradients due to poor thermal stability or transfer, the yield or performance of the final product can be affected. For example, if the process temperature is not properly controlled, processes such as etch selectivity and deposition reactions can be affected, while process uniformity can also be reduced. As a result, circuit systems formed on the semiconductor substrate can be defective in construction and / or suffer from unacceptable variations between components.

[0003] A substrate support or pedestal located in a semiconductor processing chamber is in close contact with the substrate and acts as both a heat sink and a substrate support. Most pedestals are cooled by heat conduction to a liquid-cooled substrate, where a constant coolant flow removes excess heat. It has been found that measuring the temperature of the pedestal provides a good indication of the substrate temperature. One method of determining the pedestal temperature is to measure the temperature of the coolant at the outlet of the substrate. Unfortunately, this method is limited in that the measured temperature is neither accurate nor timely in measuring the pedestal temperature. For example, the coolant temperature is measured in the substrate after the coolant has passed through several interfaces, conduits, and radiators. Using this unreliable, delayed data (i.e., as a temperature control feedback system parameter) makes it difficult to stabilize the substrate temperature.

[0004] Another technique involves diffuse reflectance spectroscopy. The wavelength of light reflected from the substrate surface is selected for monitoring. The spectrometer measures the backscattering level of the selected wavelength (which has specific energy and associated temperature characteristics) to obtain the substrate temperature. However, this method is prone to erroneous measurements due to energy received from other "hot" surfaces close to the measurement device.

[0005] Another technical attempt is to directly measure the susceptor temperature during substrate processing by placing a thermocouple detector in contact with the susceptor. However, the thermocouple detector placed in direct contact with the susceptor may be subject to radio frequency (RF) interference of the plasma used to process the substrate, resulting in inaccurate temperature measurement. In addition, the use of thermocouples will cause the undesirable result of increased susceptor complexity. The movement of the thermocouple in contact and separation with the susceptor introduces sealing requirements in both the atmosphere and the vacuum environment. In addition, leakage caused by poor sealing around the thermocouple may cause contamination and other harmful effects during substrate processing. The installation and fixing of the thermocouple detector to the susceptor are also very troublesome. For example, a small and narrow hole that is difficult to manufacture must be formed in the susceptor. In addition, since the thermocouple is usually adhered to the susceptor at the bottom of the hole with cement or other methods, the replacement of the thermocouple requires a large amount of rework and downtime.

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

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

[0008] In another embodiment, a substrate support assembly includes: an electrostatic chuck and one or more plates and a detector assembly. The detector assembly is within the electrostatic chuck and extends through the one or more plates within the electrostatic chuck. The detector assembly includes: an optical detector sensor; an optical fiber coupled to the optical detector sensor; and an insulating sheath surrounding the optical fiber. The substrate support assembly also includes a detector target having a phosphor coating, the detector target in contact with the electrostatic chuck and at a distance from the detector assembly.

[0009] In another embodiment, a substrate support assembly includes: an electrostatic chuck having one or more plates and a detector assembly. The detector assembly is within the electrostatic chuck and extends through the one or more plates within the electrostatic chuck. The detector assembly includes: an optical detector sensor; an optical fiber coupled to the optical detector sensor; an insulating sheath surrounding the optical fiber; and a housing. The housing is within the electrostatic chuck and the housing includes a cavity and a seal. The seal is disposed within a sealing recess of the housing. The optical fiber and the insulating sheath pass through the cavity and are surrounded by a sealant within the cavity. The substrate support assembly also includes: a detector target having a phosphor coating, the detector target in contact with the electrostatic chuck and at a distance from the detector assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to be able to understand the above-mentioned features of the present disclosure in detail, a more particular description of the present disclosure briefly summarized above may be made by reference to embodiments, some of which are shown in the accompanying drawings. However, it should be noted that the accompanying drawings only illustrate exemplary embodiments and are therefore not to be considered as limiting the scope of the present disclosure, as the present disclosure may admit to other equally effective embodiments.

[0011] Figure 1 A schematic cross-sectional view of a plasma processing chamber according to an embodiment of the present disclosure is shown.

[0012] Figure 2A A schematic partial cross-sectional view of a detector assembly and a cryogenic pedestal according to an embodiment of the present disclosure is shown.

[0013] Figure 2B The embodiment according to the present disclosure is shown Figure 2A Detailed schematic cross-sectional view of the detector target shown in .

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

[0015] Embodiments described herein provide a substrate support assembly that enables measurement of the temperature of a substrate during processing of the substrate at temperatures below about -20 degrees Celsius or above about 300 degrees Celsius.

[0016] Although the substrate support assembly is described below in an etch process chamber, the substrate support assembly may be used in other types of process chambers, such as physical vapor deposition chambers, chemical vapor deposition chambers, plasma enhanced chemical vapor deposition chambers, ion implantation chambers, and other systems that process substrates that require maintaining a temperature below about -20 degrees Celsius or above about 300 degrees Celsius. The substrate support assembly disclosed herein may also be used at temperatures between -20 degrees Celsius and 300 degrees Celsius.

[0017] Figure 1 A schematic cross-sectional view of an exemplary plasma processing chamber 100 is shown, shown configured as an etching chamber, having a substrate support assembly 101. The substrate support assembly 101 can be used 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, among others, and other systems capable of uniformly maintaining a surface or workpiece (e.g., substrate 124) at a temperature below about -20 degrees Celsius is desirable. Dry reactive ion etching of substrate 124 maintained at a temperature below -20 degrees Celsius or above 300 degrees Celsius enables ions to bombard the upward facing surface of the material disposed on substrate 124 while reducing spontaneous etching, thereby forming grooves with smooth, vertical sidewalls. One of the many advantages of these techniques includes improved selectivity for etching one material relative to another material at temperatures below -20 degrees Celsius. For example, the selectivity between silicon (Si) and silicon dioxide (SiO2) increases exponentially as the temperature decreases.

[0018] The plasma processing chamber 100 includes a chamber body 102 having sidewalls 104, a bottom 106, and a lid 108 that enclose a processing region 110. An injection device 112 is coupled to the sidewalls 104 and / or the lid 108 of the chamber body 102. A gas panel 114 is coupled to the injection device 112 to enable the delivery of process gases into the processing region 110. The injection device 112 may be one or more nozzles or inlet ports, or alternatively, may be a showerhead. The process gases along with any process byproducts are removed from the processing region 110 through an exhaust port 116 formed in the sidewalls 104 or the bottom 106 of the chamber body 102. The exhaust port 116 is coupled to a pumping system 140, including a throttle valve and a pump for controlling the vacuum level within the processing region 110.

[0019] The process gas is excited to form a plasma within the process region 110. In one embodiment, the process gas is excited by capacitively or inductively coupling RF power to the process gas. Figure 1In this embodiment, which is a combination of other embodiments described herein as depicted in , a plurality of coils 118 are disposed above a lid 108 of a plasma processing chamber 100 and are coupled to an RF power source 122 through a matching circuit 120 .

[0020] The substrate support assembly 101 is disposed in the processing region 110 below the injection device 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 a facility plate 107. The facility plate 107 is supported by a ground plate 111 and is 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 facility plate 107 from the ground plate 111. In some embodiments, the processing region 110 is under vacuum during processing operations. The internal connections of the substrate support assembly 101 include seals to prevent leakage through the substrate support assembly 101 into the processing region 110. In some embodiments, the processing region 110 is defined in part by the connections within the insulator plate 109.

[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 includes a molybdenum alloy or similar material and can be attached to the ESC 103 using an elastomeric material or other suitable bonding material. The ESC base assembly 105 can also be attached to the ESC 103 using a mechanical connection. The lower surface 210 ( Figure 2A ) is disposed in contact with a facility plate 107. The facility plate 107 is disposed between the ESC base assembly 105 and an insulator plate 109. The insulator plate 109 is disposed below the facility plate 107, opposite to the ESC 103.

[0022] The ESC substrate assembly 105 includes a substrate channel 115 coupled to a cryocooler 117. The cryocooler 117 is in fluid communication with the substrate channel 115 through a substrate inlet conduit 123 connected to the inlet of the substrate channel 115 and through a substrate outlet conduit 125 connected to the outlet of the substrate channel 115, so that the ESC substrate assembly 105 is maintained at a temperature below -20 degrees Celsius. The cryocooler 117 is coupled to the interface box to control the flow rate of the substrate fluid. The substrate fluid may include a material that can maintain a temperature below -50 degrees Celsius. The cryocooler 117 provides a substrate fluid that circulates through the substrate channel 115 of the ESC substrate assembly 105. The substrate fluid flowing through the substrate channel 115 enables the ESC substrate assembly 105 to be maintained at a temperature below -20 degrees Celsius, which helps to control the lateral temperature distribution of the ESC 103 so that the substrate 124 disposed on the ESC 103 is uniformly maintained at a temperature below -20 degrees Celsius. In one embodiment that may be combined with other embodiments described herein, the cryocooler 117 is a single-stage cooler operable to maintain the base fluid at a temperature below about -50 degrees Celsius. In another embodiment that may be combined with other embodiments described herein, the cryocooler 117 is a cooler that utilizes a refrigerant inside the cooler to maintain the base fluid at a temperature below -50 degrees Celsius.

[0023] The facility plate 107 includes a facility channel 234 coupled to a chiller 119. The chiller 119 is in fluid communication with the facility plate 107 via a facility inlet conduit 127 and a facility outlet conduit 129 so that the facility plate 107 is maintained at a predetermined ambient temperature. The cryocooler 119 is coupled to the interface box to control the flow rate of the facility fluid. The facility fluid may include a material that can maintain an ambient temperature between about -10 degrees Celsius and about 60 degrees Celsius. The chiller 119 provides the facility fluid, which circulates through the equipment plate 107. The facility fluid enables the facility plate 107 to be maintained at a predetermined ambient temperature, which helps maintain the insulator plate 109 at a predetermined ambient temperature.

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

[0025] The ESC 103 includes an adsorption electrode 126 disposed in the ESC 103. The adsorption electrode 126 may be configured as a monopolar or bipolar electrode, or other suitable arrangement. The adsorption electrode 126 is coupled to an adsorption power source 134 through an RF filter and a facility board 107, and the adsorption power source 134 provides DC power to electrostatically secure the substrate 124 to a support surface 130 of the ESC 103. The RF filter prevents the use of RF power to form a plasma (not shown) within the plasma processing chamber 100 from damaging electrical equipment or presenting an electrical hazard outside the chamber.

[0026] The ESC 103 includes one or more resistive heaters 128 embedded in the ESC 103. The resistive heaters 128 are used to raise the temperature of the ESC 103 to a temperature suitable for processing a substrate 124 disposed on a support surface 130, if necessary. The resistive heaters 128 are coupled to a heater power source 136 through a facility board 107 and an RF filter. The RF filter prevents the RF power used to form a plasma (not shown) within the plasma processing chamber 100 from damaging electrical equipment or presenting electrical hazards outside the chamber. The heater power source 136 may provide 500 watts or more of power to the resistive heaters 128. The heater power source 136 includes a controller (not shown) for controlling the operation of the heater power source 136, which is generally set to heat the substrate 124 when necessary so as to maintain the substrate temperature at a desired temperature, for example, below about -20 degrees Celsius. In other words, the heat from the resistive heater 128 and the cooling from the substrate fluid circulating through the ESC substrate assembly 105 are balanced to maintain the base plate 124 at a desired temperature of -20 degrees Celsius or below. In one embodiment, the ESC substrate assembly 105 includes two inner substrates (e.g., Figure 2A ). For example, the resistive heater 128 and the substrate fluid circulated through the ESC substrate assembly 105 maintain the substrate 124 at a temperature suitable for processing, which is less than about -20 degrees Celsius, such as between about -20 degrees Celsius and about -150 degrees Celsius. In another embodiment, the resistive heater 128 is used to maintain the substrate 124 at an elevated temperature, such as above about 300 degrees Celsius.

[0027] The resistive heater 128 includes a plurality of laterally separated heating zones, wherein 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 other zones. For example, the resistive heater 128 may be concentrically arranged in a plurality of separated heating zones. The separated heating zones of the resistive heater 128 help control the temperature uniformity from the lateral edge to the center of the substrate 124.

[0028] The substrate support assembly 101 may include one or more detectors disposed in the substrate support assembly 101. The ESC 103 is coupled to a detector controller 138. A detector tip 222 ( Figure 2B 105) is disposed in a base assembly 105 at or adjacent to a surface of the ESC 103 to determine the temperature of the ESC 103. Thus, a probe tip 222 in communication with a probe controller 138 may 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 a heater power source 136 such that each zone of the resistive heater 128 is independently heated such that the lateral temperature distribution of the ESC 103 is substantially uniform based on the temperature measurement such that the substrate 124 disposed on the ESC 103 is uniformly maintained at a temperature below -20 degrees Celsius.

[0029] The detector controller 138 includes a programmable central processing unit (CPU) operable in conjunction with memory (e.g., non-volatile memory) and support circuitry. The support circuitry is coupled to the CPU in a conventional manner and includes caches, clock circuits, input / output subsystems, power supplies, etc. and combinations thereof coupled to the various components of the chamber 100 to facilitate control thereof. The CPU is one of any form of general purpose computer processor used in an industrial environment, such as a programmable logic controller (PLC), for controlling the various components and subprocessors of a processing system. The memory coupled to the CPU is non-temporary and is typically one or more readily accessible memories, such as random access memory (RAM), read-only memory (ROM), a floppy disk drive, a hard disk, or any other form of local or remote digital storage.

[0030] Typically, the memory is in the form of a non-transitory computer-readable storage medium containing instructions (e.g., non-volatile memory) that, when executed by the CPU, facilitate the operation of the chamber 100. The instructions in the memory are in the form of a program product, such as a program that implements the methods of the present disclosure. The program code may conform to any of a variety 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 of the program product defines the functionality of the embodiments (including the methods described herein).

[0031] Illustrative non-transitory computer-readable storage media include, but are not limited to: (i) non-writable storage media (e.g., read-only memory devices within a computer, such as CD-ROM disks readable by a CD-ROM drive, flash memory, ROM chips, or any type of solid-state non-volatile semiconductor memory device on which information can be permanently stored, such as a solid-state hard drive (SSD); and (ii) writable storage media on which modifiable information is stored (e.g., a floppy disk within a disk drive or hard drive, or any type of solid-state random-access semiconductor memory). Such computer-readable storage media are embodiments of the present disclosure when they carry computer-readable instructions that direct the functions of the methods described herein. 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 control methods described herein are performed by a combination of software routines, ASICs, 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.

[0032] Figure 2A Shown from Figure 1 1A and 1B are schematic partial cross-sectional enlarged views of support assembly 101 of frame 2A in FIG. Support assembly 101 includes a detector assembly 200 disposed within a cavity of support assembly 101 such that components of detector assembly 200 can monitor the temperature of ESC 103. Detector assembly 200 is disposed within orifice tube 223 and lower cavity 213. Orifice tube 223 is a cavity within ESC substrate 105 and facility plate 107. Lower cavity 213 is a cavity connected to orifice tube 223. Lower cavity 213 is disposed within facility plate 107 and insulator plate 109. In some embodiments, orifice tube 223 is a cylindrical cavity that extends into lower cavity 213 within facility plate 107.

[0033] The probe assembly 200 is configured to be able to measure temperatures below about 10 degrees Celsius. For example, the probe assembly 200 can measure temperatures between about 100 degrees Celsius and about -50 degrees Celsius.

[0034] The detector assembly 200 includes a target 206 disposed at a first end 201 of the detector assembly ( Figure 2B), optical fiber 221, optical sheath 225 disposed radially outside of optical fiber 221, housing 212, and containment seal 202. Target 206 is disposed in contact with bottom surface 132 of ESC 103. Optical fiber 221 travels from first end 201 and through ESC base assembly 105 and facility board 107 to second end 203 of probe assembly 200. Second end 203 of probe assembly 200 is disposed within insulator board 109. In some embodiments, probe assembly 200 also includes an optical sensor (not shown) that is capable of reading a signal to determine at least temperature. Probe assembly 200 is connected to probe controller 138 ( Figure 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 is capable of reading the signal to determine the temperature of the ESC 103.

[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 the optical fiber 221 that extends from the housing 212 to the first end 201 of the probe assembly 200. The probe housing 212 includes portions of the optical sheath 225 and the optical fiber 221 within the lower cavity 213. The probe housing 212 also includes a recess 209 in which the seal 202 is disposed. The recess 209 is a recess on the housing face that is directed toward the ESC 103. The seal 202 is disposed in the seal recess 209 and between the probe housing 212 and the facility board 107. The seal 202 separates the processing area 110 from the insulator board 109 and other non-substrate processing areas. The processing area 110 includes portions of the facility board 107 and components in the ESC base assembly 105 located above the insulator board 109 and the housing 212. The seal 202 is a circular member surrounding the bore 205. Seal 202 is made of an elastomeric material selected to be able to seal at temperatures below about 10 degrees Celsius.

[0036] The detector housing 212 is disposed opposite the first end 201 of the detector assembly 200. The detector housing 212 represents the second end 203 of the detector assembly 200. The detector housing 212 is made of a metallic material (e.g., an alloy, etc.), and the detector housing 212 is disposed within and extends through the facility plate 107 and the insulator plate 109. The detector housing 212 includes a sealant 219 that fills the cavity 214 in the detector housing 212. In one embodiment, the sealant 219 is an epoxy material or other material suitable for filling the void 214 and does not expand or contract excessively at the temperature experienced by the support assembly 101 during operation.

[0037] Figure 2B Shows Figure 2A Detailed schematic cross-sectional view of the detector target 206 shown in box 2B of FIG. The detector target 206 is disposed at the first end 201 of the detector assembly 200. In one embodiment, the detector target 206 is recessed in the ESC base assembly 105. In another embodiment, the detector target 206 is coupled to the ESC 103.

[0038] Detector target 206 includes photoluminescent material 220, target core 211, and may include target layer 207. Target layer 207 is disposed in contact with ESC 103. The thickness of target layer 207 is sufficient to reduce the deleterious effects of thermal gradients on thermal measurements. Target layer 207 may be an adhesive that transfers thermal energy from the ESC to target 206. Target layer 207 is disposed between target core 211 and ESC 103. In some embodiments, target core 211 is made of a ceramic material, such as alumina, etc. In other words, core 211 is a ceramic core. Photoluminescent material 220 is disposed opposite target layer 207 and adhered to target core 211. Thus, target core 211 is disposed between target layer 207 and photoluminescent material 220. In some embodiments, target core 211 is a metal alloy infused with photoluminescent material 220. Although the detector target 206 is shown as being coupled to a surface of the ESC 103 , it is contemplated that the detector target 206 may be recessed within the ESC 103 .

[0039] In one embodiment, the photoluminescent material 220 is a phosphor material and has a luminescence decay rate from an excited state caused by exposure to one or more wavelengths of light related to the temperature of the photoluminescent material 220. For example, the photoluminescent material 220 can be made of a phosphor-containing material. The photoluminescent material 220 can also include a binder that is chemically compatible with the photoluminescent material 220 and transparent to wavelengths associated with the excitation and emission of the photoluminescent material 220. When the photoluminescent material 220 is a layer, the thickness of the photoluminescent material 220 is between about 0.01 mm and about 0.5 mm, such as about 0.25 mm thick. Therefore, the thickness of the photoluminescent material 220 is selected to reduce the deleterious effects of thermal gradients on thermal measurements.

[0040] The optical fiber 221 is positioned at the tip 222 of the probe assembly 200. In one embodiment, the tip 222 of the optical fiber operates as a sensor. The tip 222 of the optical fiber 221 receives light from the photoluminescent material 220, enabling optical remote temperature sensing. The optical fiber 221 is disposed and oriented relative to the probe target 206 on which the photoluminescent material 220 is disposed. Between the temperature probe tip 222 and the photoluminescent material 220 is a gap 224. In one embodiment, the distance of the gap 224 is between about 0.1 mm and about 10 mm, for example about 5 mm. The gap 224 is used to mitigate the effects of thermal cycling on the temperature probe tip 222 and to prevent thermal energy from being conducted through the orifice tube 223.

[0041] The bore tube 223 includes an optical sheath 225 and an optical fiber 221. The optical sheath 225 is disposed between the inside of the bore 205 and the outside of the optical fiber 221, and has a coating 217 between the optical fiber 221 and the optical sheath 225. The optical sheath 225 is made of a thermal and / or electrical insulating material and / or a coating material, etc. The optical fiber 221 is made of a material capable of transmitting light, such as quartz, etc. The coating 217 is a sealant capable of sealing the bore tube 223 at low temperatures to prevent vacuum leakage.

[0042] Embodiments of the present disclosure include a detector assembly that enables monitoring the temperature of an ESC in a chamber under vacuum. Coupling a target to the bottom of the ESC reduces the number of potential seals required to prevent leaks into the chamber. This is particularly advantageous in cryogenic applications, as smaller seals are more likely to fail at lower temperatures. Sealing the vacuum of the processing chamber further into the substrate support assembly allows for a larger, more robust sealing method and enhances accuracy by keeping the detector target in the vacuum. The target being in the vacuum further minimizes incorrect temperature readings caused by heat transfer between non-processing area bodies.

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

Claims

1. A substrate temperature measuring device, comprising: a substrate support assembly comprising an electrostatic chuck and one or more plates; a detector assembly disposed within the substrate support assembly and extending through one or more of the one or more plates, the detector assembly comprising: Optical detector sensor; an optical fiber coupled to the optical detector sensor; an insulating sheath surrounding the optical fiber; and A detector target is in contact with the electrostatic chuck, the detector target comprising a coating of photoluminescent material, wherein the detector target is spaced apart from the detector assembly. 2 . The substrate temperature measurement apparatus of claim 1 , wherein the probe assembly further comprises a seal disposed on a housing disposed within the one or more plates. 3 .

3. The substrate temperature measurement apparatus of claim 2, wherein the seal is disposed about the optical fiber and is configured to maintain a vacuum about the electrostatic chuck. 4 . The substrate temperature measurement apparatus of claim 2 , wherein the housing further comprises a sealant disposed within the cavity within 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 detector 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 detector sensor is directed toward the coating of the detector target.

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

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

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

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

12. The substrate support assembly of claim 9, wherein the detector 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 detector sensor is directed toward the coating of the detector target.

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

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

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

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

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

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

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

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