Light pipe for high-temperature substrate processing

Abstract

A substrate processing system according to one embodiment includes a processing chamber and an optical pyrometer assembly for measuring thermal radiation emitted from substantially a portion of a target surface. The optical pyrometer includes a light pipe comprising a core and a hollow sheath surrounding the core. The core and the sheath are concentric with each other. The sheath is formed by a chemical vapor deposition process and includes local protrusions within its hollow interior to maintain the position of the core within the sheath. Specifically, the local protrusions are formed to center at least the distal end of the core within the sheath. The temperature of the target surface is determined from the intensity of a portion of the thermal radiation emitted near at least one wavelength.

Description

Technical Field

[0001] Cross-reference to Related Applications This application is based on and claims priority to U.S. Provisional Patent Application No. 63 / 381,021, filed Oct. 26, 2022, the entire contents of which are hereby incorporated by reference as if fully set forth herein in their entirety.

[0002] This disclosure relates to semiconductor processing equipment, and more particularly, to a concentric light pipe for high-temperature substrate processing applications.

Background Art

[0003] Semiconductor processing equipment is used for the deposition, patterning, and processing of thin films and coatings. Conventional substrate processing chambers provide a pedestal or chuck for supporting the substrate for processing. In the processing of semiconductor device materials such as semiconductor wafers, one of the important process parameters is temperature. Reproducible, accurate, and process-independent measurement of wafer temperature is one of the most important requirements for semiconductor processing equipment in integrated circuit manufacturing.

[0004] In some applications, temperature can be measured using contact-type temperature sensors such as thermocouples. However, these sensors are not well-suited to many wafer processing environments. As a result, other types of temperature measurement are required in more extreme wafer processing environments. For example, non-invasive temperature measurement techniques such as optical pyrometry are used in many wafer processing applications, including but not limited to rapid thermal processing (RTP). Unlike contact-based temperature measuring devices, measuring temperature using an optical pyrometer does not require contact with the wafer. As is well known, an optical pyrometer measures temperature based on electromagnetic radiation (light) emitted from an object (wafer). Conventional optical pyrometers use optical fibers, light pipes, lenses, or other focusing devices to transmit light to a photosensing device that measures the flux density or intensity of light emitted from an object (wafer, or susceptor). From these measurements, the temperature of the object can be calculated.

[0005] A light pipe is a rod made of sapphire, quartz, or other optical material, typically about 1-2 mm in diameter, and is used to collect / transmit light across a wide spectral range (from UV to IR). Light collection / transmission is based on the same operating principle as optical fibers, but usually without a cladding layer. One advantage of light pipes is that they can be inserted through small holes, making them very suitable when larger viewports are impossible or not permitted. Light pipes are non-image sensors, and their spot size is proportional to the working distance. This is the main reason why light pipes are often used at their tip, close to the object being measured. One advantage of sapphire light pipes is that they collect and transmit more signal than typical-sized lenses, enabling lower temperature measurements. While high-temperature measurements are the primary application of light pipes, they can also be used as sensor heads in many other applications.

[0006] Using light pipes in deposition processes also requires continuous light pipe purging. The flat front and cylindrical surfaces of the light pipe are polished surfaces. The flat front is where light / IR enters the light pipe, and the cylindrical surface forms the interface of total internal reflection, trapping the light / IR within the light pipe. A dirty flat front can reduce transmittance and lead to signal attenuation. A dirty cylindrical surface may exhibit scattering, which can then result in either signal loss or stray light entering the light pipe. For longer-term use, especially in applications involving deposition processes commonly found in semiconductor manufacturing, the light pipe surface must be kept clean. The most common technique for keeping such surfaces clean is to use a sheath around the light pipe and utilize the space between the light pipe rod and the sheath for inert gas purging. The front is protected from contamination by controlling the purge flow to be laminar at the light pipe end faces.

[0007] Considering the above, existing light pipe designs use a concentric layout. However, because it is difficult to control concentricity at the free end of a long, slender light pipe, the tip of the light pipe is eccentric with respect to the sheath and has a contact point with the sheath. This contact point locally obstructs the purge flow, resulting in uneven purging. Such uneven purging further causes localized surface contamination, shortening the service life before cleaning. To control concentricity, one common design is to use a recessed quartz sheath to control concentricity. A concentric design ensures that the sheath is always concentric with respect to the light pipe. [Overview of the Initiative]

[0008] A substrate processing system according to one embodiment includes a processing chamber and an optical pyrometer assembly for measuring synchrotron radiation emanating from substantially a portion of a target surface. The optical pyrometer includes a light pipe comprising a core and a hollow sheath surrounding the core. The core and the sheath are concentric with each other. The sheath is formed by a chemical vapor deposition process and includes local protrusions within its hollow interior to maintain the position of the core within the sheath. Specifically, the local protrusions are formed to center at least the distal end of the core within the sheath. The temperature of the target surface is determined from the intensity of a portion of the thermal radiation emitted near at least one or more wavelengths. [Brief explanation of the drawing]

[0009] [Figure 1] This is a cross-sectional view of a light pipe according to the first embodiment. [Figure 2A] This is a cross-sectional view of the first mandrel. [Figure 2B] This is a cross-sectional view showing the first sheath grown on the first mandrel. [Figure 2C] This is a cross-sectional view of the first sheath formed on the first mandrel, showing the state after the mandrel has been removed. [Figure 3] This is a cross-sectional view of a light pipe according to the second embodiment. [Figure 4A] This is a cross-section of the second mandrel. [Figure 4B] This is a cross-sectional view showing the second sheath grown on the second mandrel. [Figure 4C] This is a cross-sectional view of the second sheath formed on the second mandrel, showing the state after the mandrel has been removed. [Figure 5] This is a cross-sectional view of the second sheath, showing the ridge along its entire length. [Figure 6] A second cross-sectional view of the sheath shows a further machined sheath with the ridge partially removed to create a continuous ring space for uniform purging at the distal end of the sheath. [Figure 7A] This is a diagram of the first mandrel. [Figure 7B]The sheath grown on the first mandrel is shown. [Figure 7C] The step of removing the first mandrel is shown. [Figure 7D] The first sheath that was formed is shown. [Figure 8] Figure 3 is a perspective view of the light pipe. [Figure 9] This is a schematic diagram of an exemplary semiconductor processing device. [Modes for carrying out the invention]

[0010] As discussed herein, many semiconductor processes operate at high temperatures, and therefore, sensor heads (light pipes) used to measure the temperature of a target surface must also operate at such high temperatures.

[0011] Figure 9 is a schematic diagram showing an exemplary semiconductor processing apparatus 1. Generally, the apparatus 1 includes a process chamber 2 containing an induction heating coil 6. A detector and an electronic module 3 are provided and operably coupled to one or more light pipes 4. For example, each light pipe 4 can be operably coupled to the module 3 by an optical fiber cable 5. As shown below, the light pipes 4 are designed to measure the temperature of a target surface, such as the temperature of a specific area within the process chamber 2. In Figure 9, there are multiple (4) light pipes 4 shown at different locations within the process chamber 2 to measure the temperature of different areas within the process chamber 2.

[0012] As is well known, the use of high-temperature measurement methods for non-invasive temperature measurement and control is necessary in some semiconductor processing applications, such as rapid thermal processing (RTP). A high-temperature measurement method involves measuring the emission of light from a silicon wafer using a photodetector in a specified spectral band and calculating the wafer temperature based on the measured (emitted) thermal radiation data. Electronic module 3 includes a photodetector configured to receive output from an optical assembly including a light pipe and generate at least one signal representing radiation, and a temperature circuit that converts at least one signal into a temperature value. In this way, the temperature of the target surface is obtained and displayed to the user on a display or the like.

[0013] For example, an apparatus or system for measuring the temperature of an assembly inside a process chamber 2 may comprise a light pipe, an optical assembly configured to collimate, filter, and focus radiation (e.g., infrared radiation) from one end of the light pipe, a photodetector configured to receive the output from the optical assembly and generate at least one signal representing (infrared) radiation, and a temperature circuit that converts at least one signal into a temperature value. Furthermore, a controller may be configured to receive the temperature value from the temperature circuit and adjust one or more processes in the process chamber 2 based on the temperature value.

[0014] The electronic module 3 may be a commercially available device suitable for use in this application and can be used with a light pipe capable of collecting / transmitting light over a wide spectral range (from UV to IR). For example, in one embodiment, the light pipe (hyprometer assembly) is used to collect infrared radiation from an internal assembly of the process chamber 2.

[0015] concentric design As discussed herein, a concentric design is desirable for properly positioning a light pipe within a surrounding sheath. The sheath is configured to surround the light pipe, but has an opening at the end of the light pipe, and this opening is configured to allow radiation (e.g., infrared radiation) into the light pipe. The sheath allows a purge gas flow to reduce contamination of the light pipe. As further mentioned, depressions can be used to provide concentricity of the light pipe and the surrounding sheath.

[0016] High-temperature applications Sapphire has a high melting point and is thus a preferred option for the light pipe in many applications, as the main problems regarding the use of quartz sheaths remain for high-temperature applications. Above a certain high temperature point, quartz sags under its own weight. For the same grade of quartz, the deflection is a function of temperature and time. At 1200 °C, a low-OH quartz tube with an ID of 135 mm and a wall thickness of 2 mm may collapse by more than 15 mm in less than 50 hours. Other issues regarding the use of quartz remain, including the difficulty of cooling the tip as quartz is not an excellent heat conductor. Based on these limitations, the use of quartz sheaths is not ideal in high-temperature processes such as SiC epitaxy, which typically runs at about 1600 °C.

[0017] Selection of high-temperature materials for light pipe sheaths Single-crystal sapphire tubes are currently used as light pipe sheaths in high-temperature applications. However, the manufacturing method of the quartz sheath with depressions does not function with sapphire, and a concentric design for the sapphire sheath is currently lacking. Therefore, alternative materials that can be used as sheaths suitable for high-temperature applications are needed.

[0018] One such material is pure silicon carbide (SiC), which has a high operating temperature and excellent thermal conductivity. Silicon carbide can be grown using the chemical vapor deposition (CVD) process. CVD SiC formed by chemical vapor deposition is available in a variety of resistivity values. Low resistivity grades are commonly used because they are relatively easy to process by electrical discharge machining (EDM) and can be used in non-induction heating systems. However, in reactors with induction heating, the sheath is heated by the induction heating device. High resistivity silicon carbide, however, remains unheated by the induction heating device and is therefore the only grade of CVD SiC that functions in induction heating systems.

[0019] As stated above, this disclosure relates to a substrate processing system, such as a semiconductor processing system (e.g., the system shown in Figure 9), which includes a processing chamber configured to house and process a substrate (e.g., a wafer). More specifically, this disclosure relates to an optical pyrometer assembly for measuring thermal radiation emitted substantially from a portion of a target surface within a processing chamber.

[0020] Optical high-temperature sensor / light pipe 100 Next, referring to Figures 1, 2A–2C, and 7A–7D, one exemplary optical pyrometer sensor head 100 includes a light pipe comprising a core 110 and a hollow sheath 120 surrounding the core 110. The core 110 and the sheath 120 are concentric with each other. As described herein, the sheath 120 includes local projections 130 within its hollow interior (lumen) to maintain the position of the core 110 within the sheath 120. The temperature of the target surface is determined from the intensity of a portion of the nearby emitted light at least one wavelength.

[0021] Core 110 The core 110 can be formed from any optical material suitable for high-temperature applications. For example, the core 110 may be a sapphire rod.

[0022] Sheath 120 According to this disclosure, the sheath 120 is formed from high-resistivity silicon carbide (SiC) and is formed by a chemical vapor deposition process and includes localized protrusions 130. For example, the CVD SiC may be an undoped / minimally doped form of CVD SiC. High-resistivity SiC has a temperature of about 10 at room temperature. 6 It may be a material having a resistivity of (1E6) ohms-cm or more.

[0023] The local projection 130 is designed to position and center the core 110 within the sheath 120. More specifically, the local projection 130 functions as a centering mechanism for centering at least a portion of the core 110 positioned within the sheath 120. Specifically, the sheath 120 is a hollow structure with a lumen, and the local projection 130 is formed within the lumen along the inner surface of the sheath 120. The local projection 130 extends radially inward to provide selective contact (contact points) between the core 110 and the sheath 120. As will be shown and described in more detail herein, the local projection 130 may take the form of a separate (convex) ridge formed circumferentially along the interior of the sheath 120.

[0024] The localized projection 130 also defines an annular space 135 between the core 110 and the sheath 120. The chemical vapor deposition process used to manufacture the sheath 120 is described in more detail below.

[0025] Optical Pyromometer Sensor / Light Pipe 101 Figures 3, 4A-4C, and 8 show an optical pyrometer sensor 101 very similar to the optical pyrometer 100, and the light pipe includes a core 110 and a hollow sheath 121 surrounding the core 110. The core 110 and the sheath 121 are concentric with each other. As described herein, the sheath 121 includes local projections 131 within its hollow interior (lumen) to maintain the position of the core 110 within the sheath 121.

[0026] Sheath 121 According to this disclosure, the sheath 121 is formed from silicon carbide (SiC) by a chemical vapor deposition process and includes local projections 131. Local projections 131 are similar to local projections 130 and are designed to position and center the core 110 within the sheath 121. More specifically, local projections 131 function as a centering mechanism for centering at least a portion of the core 110 positioned within the sheath 121. Local projections 131 extend radially inward to provide selective contact (contact points) between the core 110 and the sheath 121. Local projections 131 also define an annular space 135 between the core 110 and the sheath 121. The chemical vapor deposition process used to manufacture the sheath 121 is described in more detail below.

[0027] As illustrated and described in more detail herein, the local projection 131 may be in the form of a separate ridge or rail formed circumferentially and extending longitudinally within the sheath 121.

[0028] CVD process SiC is typically grown on a mandrel and then removed after growth, so the formed article does not require further heavy machining.

[0029] First manufacturing method Next, referring to Figures 1, 2A-2C, and 7A-7D, a first manufacturing method is shown, which includes the use of a first mandrel 20. The first mandrel 20 can be considered a recessed mandrel, since it includes a plurality of small recesses formed along its outer surface. Thus, the first mandrel 20 has a distal end 21 and a proximal end 23 on the opposite side. The first mandrel 20 has a conventional cylindrical shape and includes a plurality of recesses 25 formed along its outer surface.

[0030] For example, the multiple depressions 25 can be located within one region of the first mandrel 20, and more specifically, the multiple depressions 25 are located at or near the distal end 21 of the first mandrel 20. The multiple depressions 25 are formed circumferentially around the first mandrel 20. For example, there may be at least two depressions 25 (e.g., located 180 degrees apart), however, more generally, the first mandrel 20 has three or more depressions 25. Preferably, the multiple depressions 25 are arranged at equal intervals from one another. Each depression 25 is in the form of a concave crater formed on the outer surface of the first mandrel 20. Naturally, the depressions 25 represent a negative (reverse) impression of a local protrusion 130 formed as part of the final sheath 120. Thus, each depression 25 corresponds to a single local elevation or protrusion formed within the sheath 120. Therefore, the selected depth of the recess 25 is chosen considering the intended and desired size of the local projection 130 formed on the final sheath 120, since the degree of recess formed on the first mandrel 20 directly corresponds to the degree of recess, with the local projection 130 protruding (radially inward) from the inner surface of the sheath 120 as described herein. Furthermore, the size of the annular space 135 is determined by the size of the local projection 130. In particular, as the height of the local projection 130 increases, the size of the annular space 135 also increases.

[0031] It will also be understood that there may be multiple rings of spaced-out local projections 130. Each ring of local projections (ridges) 130 contacts the core 110 within the sheath 120 and functions to center the core 110. It is important that at least the distal end of the core 110 is centered within the distal end of the sheath 120.

[0032] The first mandrel 20 can be formed from any number of suitable materials. For example, the first mandrel 20 can be formed from graphite, and the multiple depressions 25 can be machined into the graphite mandrel.

[0033] Once the first mandrel 20 is manufactured to have the desired specifications (Figure 2A), the next step is to form the sheath 120 using a CVD process. As is known, the CVD process involves growing a target material, which in this case is SiC, on a substrate, in this case on the first mandrel 20. The CVD process continues until the formed object (sheath 120) has the desired specifications (e.g., thickness). Figure 2B shows the sheath 120 formed on the first mandrel 20.

[0034] Next, as shown in Figure 2C, the mandrel material is removed, but the first mandrel 20 is removed using an appropriate process that leaves the formed sheath 120 completely intact. For example, the mandrel material can be removed by burning or etching the mandrel material, and as a result, the first mandrel 20 is completely removed from the inside of the formed sheath 120.

[0035] Once the mandrel material is removed, the sheath 120 is exposed. The SiC material has a native oxide layer that protects the SiC sheath from oxidation at high temperatures; therefore, removing the first mandrel using an etching solution or the like does not adversely affect, damage, or wear down the sheath.

[0036] When the mandrel material is completely removed, the formed sheath 120 remains. As shown in Figure 2C, the formed sheath 120 has a lumen defined by the inner surface (inner surface or inner diameter) of the formed sheath 120. Local projections 130 are formed along the inner surface and extend radially inward into the lumen. In Figure 2C, there are at least three local projections 130 arranged at equal intervals (e.g., 120-degree intervals).

[0037] In Figure 2C, each local projection 130 is generally shown to have a dome-shaped form. However, this is merely an illustrative shape. In this illustrated shape, the inner surface of the local projection 130 is curved. However, it will be understood that other shapes are equally possible, including different inner surface shapes for each local projection 130. For example, the inner surface can be flat. The inner core 110 has a cylindrical (rod) shape, and therefore the inner surface of the local projection 130 represents the contact point between the core 110 and the sheath 120, and more specifically, allows at least the distal end of the core 110 to maintain a central position within the sheath 120.

[0038] The formed sheath 120 may undergo minor machining, chamfering, and tolerance control. For example, the sheath 120 and the local projection 130 must be manufactured to such a specification that the local projection 130 contacts and is centered on the inner core 110 within the sheath 120. Conventional chamfering and tolerance control techniques can be used.

[0039] Upon completion, the optical pyrometer 100 is assembled by inserting the core 110 into the hollow sheath 120. As previously mentioned, the local projection 130 functions to center the core 110 within the sheath 120.

[0040] In this way, the optical pyrometer 100 is formed and assembled and may include a sapphire rod (core 110) and a SiC outer sheath 120 formed by a CVD process.

[0041] Second manufacturing method Next, referring to Figures 3, 4A-4C, 5, 6, and 8, a second manufacturing method is shown, which involves the use of a second mandrel 10. The second mandrel 10 can be considered a grooved mandrel in that it includes a plurality of channels or grooves formed therein. Thus, the second mandrel 10 has a distal end and a proximal end on the opposite side. Conventionally, the second mandrel 10 has a cylindrical shape and includes a plurality of longitudinal grooves 14 that extend longitudinally along the length of the second mandrel 10. For example, the plurality of longitudinal grooves 14 can extend along the entire length of the first mandrel 10, or can be formed to extend to less than the entire length. The plurality of longitudinal grooves 14 are formed circumferentially around the second mandrel 10. For example, there may be at least two longitudinal grooves 14 (e.g., arranged 180 degrees apart). However, more generally, it is common for the second mandrel 10 to have three or more longitudinal grooves 14. Preferably, the multiple longitudinal grooves 14 are arranged at equal intervals from one another. Each longitudinal groove 14 is in the form of a concave groove or channel formed on the outer surface of the second mandrel 10. Naturally, the longitudinal grooves 14 represent the negative (reverse) impression of the local projection 131 formed as part of the final sheath 121. The selected depth of the longitudinal grooves 14 is therefore selected in consideration of the intended and desired size of the local projection 131 formed on the final sheath 121, as the degree to which the recess formed in the second mandrel 10 protrudes (radially inward) from the inner surface of the sheath 121, as described herein. Furthermore, the size of the annular space 135 is determined by the size of the local projection 131. In particular, as the height of the local projection 131 increases, the size of the annular space 135 also increases.

[0042] Since the longitudinal groove 14 is in the form of a channel or groove, the local projection 131 formed along the sheath 121 can be considered a rail (longitudinal rail).

[0043] The second mandrel 10 can be formed from any number of suitable materials. For example, the second mandrel 10 can be formed from graphite, and multiple longitudinal grooves 14 can be machined into the graphite mandrel.

[0044] Once the second mandrel 10 is manufactured to have the desired specifications (Figure 4A), the next step is to form the sheath 121 using a CVD process. As is known, the CVD process involves growing a target material, in this case SiC, on a substrate, in this case on the first mandrel 10. The CVD process continues until the formed object (sheath 121) has the desired specifications (e.g., thickness). Figure 4B shows the sheath 121 formed on the first mandrel 10.

[0045] Next, as shown in Figure 4C, the second mandrel 10 is removed by sliding the second mandrel 110 from the center of the formed sheath 121. This leaves the formed sheath 121 behind. As shown in Figure 4C, the formed sheath 121 has a lumen defined by the inner surface (inner surface or inner diameter) of the formed sheath 121. Local projections 131 are formed along the inner surface and extend radially inward into the lumen. In Figure 4C, there are at least three local projections (rails) 131 arranged at equal intervals (e.g., 120-degree intervals).

[0046] In Figure 4C, each local projection (rail) 131 is shown to have a substantially rectangular shape. However, this is an illustrative shape and not limiting. In this illustrated shape, the inner surface of the local projection 131 is planar (flat). However, it will be understood that other shapes are equally possible, including different inner surface shapes for each local projection 131. For example, the inner surface may have an arcuate (concave) shape, in contrast to the flat inner surface shown in the figure. The inner core 110 has a cylindrical (rod) shape, and therefore the inner surface of the local projection 131 represents the contact point between the core 110 and the sheath 121, and more specifically, allows the core 110 to maintain its central position within the sheath 121.

[0047] The formed sheath 121 may undergo minor machining, chamfering, and tolerance control. For example, the sheath 121 and the local projection 131 must be manufactured to such a specification that the local projection 131 contacts and is centered on the inner core 110 within the sheath 121. Conventional chamfering and tolerance control techniques can be used.

[0048] Upon completion, the optical pyrometer 100 is assembled by inserting the core 110 into the hollow sheath 121. As previously mentioned, the local projection 131 functions to center at least the distal end of the core 110 within the sheath 121.

[0049] In this way, the optical pyrometer 100 is formed and assembled and may include a sapphire rod (core 110) and a SiC outer sheath 121 formed by a CVD process.

[0050] Figure 5 shows an outer sheath 121 with localized projections (ridges or rails) 131 that initially form the entire length of the outer sheath 121. After manufacturing, the localized projections 131 can be modified at one end (distal end) of the outer sheath 121. More specifically, at the distal end, the length of each localized projection can be removed to form an open annular space 139 at the end of the outer sheath 121 without the localized projections 131, as shown in Figure 6. The purpose of the annular space 139 without the localized projections 131 is to allow the purge flow to become uniform before exiting the end of the light pipe assembly, ensuring that the flow rate is evenly distributed. This can be done by polishing the outer sheath 121 as formed in Figure 5 to remove each distal portion of the localized projections 131 that initially extend over the entire length of the sheath. Alternatively, the mandrel can be formed by longitudinal grooves 14 that do not extend over the entire length, and in particular, one end of the mandrel may lack the longitudinal grooves 14. When the outer sheath is formed (grows) in this way, including partial localized protrusions 131 (not extending the entire length of the sheath), additional final touch-ups can be made by polishing. This method is particularly useful when the design is for a thinner, deeper grooved sheath. Creating a ring space using only polishing becomes problematic in that case, as the amount of material removed may be greater than what is available in the wall thickness.

[0051] In one embodiment, the length of the annular space 139 can be 30 mm, measured from the distal end of the light pipe (to the local projection(s)). However, this is essentially illustrative, and this length may vary depending on the application. The size of the annular space 139 is selected considering the following: (1) a size that ensures uniform flow out of the light pipe. Therefore, a length without ridges is advantageous as it allows time for the flow to merge and stabilize. (2) On the other hand, if the distance over which the light pipe rod and sheath are not in contact is too long, the concentricity decreases, so a balance must be struck between these two considerations.

[0052] Figure 8 is a perspective view of the light pipe 101.

[0053] This disclosure describes an optical pyrometer suitable for use in high-temperature substrate processing applications, and in particular discloses a light pipe sheath formed from SiC and a method for manufacturing the same.

[0054] Similar figures in the drawings represent similar elements across several drawings, and it should be understood that not all components and / or steps described with reference to the drawings are required for all embodiments or configurations.

[0055] The terms used herein are for the sole purpose of describing specific embodiments and are not intended to limit the invention. Where used herein, the singular forms “a,” “an,” and “the” are intended to include the plural form unless otherwise clearly indicated by the context. The terms “comprise” and / or “comprising,” when used herein, specify the presence of the described features, integers, steps, actions, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, actions, elements, components, and / or groups thereof.

[0056] Furthermore, the usage and terminology used herein are for illustrative purposes only and should not be considered restrictive. The use of “including,” “comprising,” “having,” “containing,” “involving,” and variations thereof herein means to include the items listed therein and their equivalents, as well as any additional items.

[0057] The subject matter described above is provided for illustrative purposes only and should not be construed as limiting. Various modifications and changes to the subject matter described herein can be made without following the examples and embodiments and applications described herein, and without departing from the true spirit and scope of the invention as set forth in the following claims.

Claims

1. A substrate processing system, Processing chamber and An optical pyrometer assembly for measuring thermal radiation emitted from substantially a portion of a target surface, wherein the optical pyrometer is A light pipe comprising a core and a hollow sheath surrounding the core, wherein the core and the sheath are concentric with each other, the sheath is formed by a chemical vapor deposition process and includes localized projections within its hollow interior to maintain the position of the core within the sheath, The temperature of the target surface is determined from the intensity of a portion of the emitted thermal radiation near at least one wavelength, according to the substrate processing system.

2. The substrate processing system according to claim 1, wherein the core includes a sapphire rod and the sheath is formed from high-resistance silicon carbide (SiC).

3. The substrate processing system according to claim 1, wherein the localized protrusion comprises a circumferentially formed ridge inside the hollow interior of the sheath.

4. The substrate processing system according to claim 1, wherein the localized projection includes a separate ridge or rail formed circumferentially and extending longitudinally within the hollow interior of the sheath.

5. The substrate processing system according to claim 1, further comprising: a photodetector configured to receive the output from the light pipe and generate at least one signal representing the emitted thermal radiation; and a temperature circuit that converts the at least one signal into a temperature value of the target surface.

6. A method for forming an optical high-temperature sensor head (light pipe), To provide a mandrel that can have a recess or groove formed along its outer surface, Forming a hollow sheath on the outer surface of the mandrel by a chemical vapor deposition process, wherein the sheath includes localized ridges or rails formed along the hollow interior of the sheath by recesses or longitudinal grooves formed along the outer surface of the mandrel, and The method comprising inserting a core into the hollow sheath and maintaining a concentric arrangement between the core and the hollow sheath by a ridge or rail that centers the core within the hollow sheath.

7. The method according to claim 6, wherein the core includes a sapphire rod and the sheath is formed from high-resistance silicon carbide (SiC).

8. The method according to claim 6, wherein the mandrel has a cylindrical shape and includes a plurality of recesses, the plurality of recesses are formed along the outer surface of the mandrel, and the ridge is formed inside the hollow interior of the sheath.

9. The method of claim 8, further comprising the step of removing the mandrel after the localized elevation has been formed by the chemical vapor deposition process, wherein the step of removing the mandrel includes the step of burning or etching the mandrel until the mandrel is completely removed from the inside of the formed hollow sheath.

10. The method according to claim 6, wherein the mandrel has a cylindrical shape and includes a plurality of longitudinal grooves, the plurality of longitudinal grooves are formed along the outer surface of the mandrel, and the rail is formed inside the hollow of the sheath.

11. The method according to claim 10, wherein each of the plurality of longitudinal grooves includes a straight groove formed within the outer surface of the mandrel.

12. The method according to claim 11, wherein each longitudinal groove extends along the entire length of the mandrel.

13. The method according to claim 11, wherein each longitudinal groove extends to less than the total length of the mandrel.

14. The method according to claim 11, wherein the shape of the longitudinal groove is such that the mandrel can slide laterally outward from the formed sheath surrounding the mandrel.

15. The method according to claim 12, further comprising the step of removing an end section at one end of each rail in order to define a rail-free, open annular purge space between the core and the sheath.

16. The method according to claim 15, wherein the step of removing the end section includes polishing the end section of the rail.

17. The method according to claim 6, wherein the step of forming the hollow sheath on the outer surface of the mandrel by the chemical vapor deposition process includes the step of epitaxially growing SiC on the outer surface of the mandrel, wherein the SiC grows such that depressions or longitudinal grooves along the outer surface of the mandrel are completely filled and a SiC layer is formed outside the depressions or longitudinal grooves, thereby forming the outer sheath.

18. A light thermometer sensor head (light pipe) formed by the method described in claim 6.

19. A method for heat treatment of a semiconductor substrate in a processing chamber, The steps include heating the substrate and A step of sampling light emitted from a target surface within a selected wavelength range using an optical pyrometer including a light pipe comprising a core and a hollow sheath surrounding the core, wherein the core and the sheath are concentric with each other, the sheath is formed by a chemical vapor deposition process and includes local protrusions within its hollow interior to maintain the position of the core within the sheath, The method comprising the step of controlling the heating to achieve a desired processing temperature as a function of the sampled thermal radiation emitted from the target surface.

20. An optical pyrometer assembly for measuring synchrotron radiation substantially emanating from a portion of a semiconductor substrate in a processing chamber, wherein the optical pyrometer assembly is A light pipe comprising a core and a hollow sheath surrounding the core, wherein the core and the sheath are concentric with each other, the sheath is formed by a chemical vapor deposition process, and includes localized projections within its hollow interior to maintain the position of the core within the sheath, A fiber optic cable that transmits the thermal radiation sampled by the light pipe to a detector, The optical pyrometer assembly includes a detector and an electronic module that receive the thermal radiation signal, convert the thermal radiation signal into an analog signal, then digitize the thermal radiation signal, and calculate its temperature based on stored calibration data.

21. An optical pyrometer assembly for measuring synchrotron radiation substantially emanating from a portion of a semiconductor substrate in a processing chamber, wherein the optical pyrometer assembly is A light pipe comprising a core and a hollow sheath surrounding the core, wherein the core and the sheath are concentric with each other, the sheath is formed by a chemical vapor deposition process, and includes a plurality of elongated rails formed circumferentially inside its hollow interior to maintain the concentricity of the core and the sheath, the light pipe comprising the light pipe, the optical pyrometer assembly.

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