Method and apparatus for measuring edge ring temperature - Patents.com

Abstract

An apparatus for measuring the temperature of an assembly inside a processing chamber, the apparatus may include: a light pipe disposed between a lamp radiation filtering window and the assembly, the light pipe having a first end with a bevel configured to redirect infrared radiation emitted from the assembly through the light pipe and having a second end distal to the first end; an optical assembly configured to collimate, filter, and focus the infrared radiation from the second end of the light pipe; an optical detector configured to receive output from the optical assembly and generate at least one signal representative of the infrared radiation; a temperature circuit that converts the at least one signal to a temperature value; and a controller configured to receive the temperature value and make adjustments to other process parameters of the processing chamber based on the temperature value.

Description

[Technical field]

[0001] SUMMARY OF THE PREFERRED EMBODIMENTS Embodiments of the present principles relate generally to heat gain in semiconductor manufacturing processes. [Background technology]

[0002] Semiconductor processes may use heating to bring a wafer up to a process temperature for a variety of reasons. In some processes, the wafer is heated before contacting the components of the process chamber. A large temperature mismatch between the wafer and the process chamber components may result in thermal shock to the wafer when it is contacted with the components. Thermal shock may have undesirable effects on the wafer, such as warping and / or the wafer popping off the holding surface. The inventors have found that by bringing the chamber components and the wafer to similar temperatures, the undesirable effects may be prevented or reduced. However, measuring components used in chambers with heating provided by radiant lamps poses some challenges due to the lamp radiation, which not only heats the wafer but also affects the temperature readings of the chamber components.

[0003] Accordingly, the present inventors have provided an improved method and apparatus for obtaining the temperature of a component used within a semiconductor processing chamber. Summary of the Invention

[0004] Provided herein are methods and apparatus for obtaining thermal information of an internal assembly of a semiconductor processing chamber.

[0005] In some embodiments, an apparatus for measuring a temperature of an assembly inside a processing chamber may include a lamp radiation filtering window configured to be positioned between a lamp radiation source and the assembly, a light pipe configured to be positioned between the lamp radiation filtering window and the assembly, the light pipe having a first end with a bevel configured to redirect infrared radiation emitted from the assembly through the light pipe and having a second end distal to the first end, an optical assembly configured to collimate, filter, and focus infrared radiation from the second end of the light pipe, an optical detector configured to receive output from the optical assembly and generate at least one signal representative of the infrared radiation, and a temperature circuit that converts the at least one signal to a temperature value.

[0006] In some embodiments, the apparatus, wherein the lamp radiation filtering window is made of a wet quartz material that absorbs radiation having a wavelength of about 2.7 microns to about 2.8 microns, the light pipe is made of a sapphire material, the light pipe is configured to be installed parallel to a top surface of the assembly in a processing chamber, and the bevel has an angle of about 45 degrees, the apparatus further comprises a sheath configured to surround the light pipe while providing an opening at a first end of the light pipe configured to allow infrared radiation into the light pipe, the sheath having a purge channel configured to flow a purge gas around the light pipe to reduce contamination of the light pipe, and a housing comprising a liquid cooling channel configured to flow a coolant around at least a portion of the light pipe and at least a portion of the optical assembly to reduce background thermal radiation, the optical assembly includes a first aspheric condenser lens, an optical bandpass filter, and a second aspheric condenser lens, and / or the optical assembly further comprises a germanium lens with an anti-reflective coating interposed between the first aspheric condenser lens and the second aspheric condenser lens.

[0007] In some embodiments, an apparatus for measuring a temperature of an assembly inside a processing chamber may include a light pipe configured to be disposed between a lamp radiation filtering window and an assembly, the light pipe having a first end with a bevel configured to redirect infrared radiation emitted from the assembly through the light pipe and having a second end distal to the first end, an optical assembly configured to collimate, filter, and focus infrared radiation from the second end of the light pipe, an optical detector configured to receive output from the optical assembly and generate at least one signal representative of the infrared radiation, and a temperature circuit that converts the at least one signal to a temperature value.

[0008] In some embodiments, the apparatus is configured to detect radiation from a surface of the assembly having a wavelength of about 2.7 microns to about 2.8 microns, the light pipe is made of a sapphire material, the light pipe is configured to be installed parallel to a top surface of the assembly in a processing chamber, and the bevel has an angle of about 45 degrees, the apparatus further comprises a sheath configured to surround the light pipe while providing an opening at a first end of the light pipe configured to allow infrared radiation into the light pipe, the sheath having a purge channel configured to flow a purge gas around the light pipe to reduce contamination of the light pipe, and a housing surrounding the light pipe and at least a portion of the optical assembly, the housing having a liquid cooling channel for flowing a coolant to reduce background thermal noise, the optical assembly includes a first aspheric condenser lens, an optical bandpass filter, and a second aspheric condenser lens, and / or the optical assembly further comprises a germanium filter with an anti-reflective coating.

[0009] In some embodiments, an apparatus for measuring a temperature of an assembly inside a processing chamber may include a light pipe configured to be disposed between a lamp radiation filtering window and an assembly, the light pipe having a first end with a bevel configured to redirect infrared radiation emitted from the assembly through the light pipe and having a second end distal to the first end; an optical assembly configured to collimate, filter, and focus the infrared radiation from the second end of the light pipe; an optical detector configured to receive output from the optical assembly and generate at least one signal representative of the infrared radiation; a temperature circuit that converts the at least one signal to a temperature value; and a controller configured to receive the temperature value and adjust one or more processes of the processing chamber based on the temperature value.

[0010] Other and further embodiments are disclosed below.

[0011] Embodiments of the present principles, briefly summarized above and discussed in more detail below, can be understood by reference to exemplary embodiments of the principles as illustrated in the accompanying drawings, which, however, illustrate only typical embodiments of the present principles, and therefore should not be considered as limiting in scope, since the present principles are susceptible of other equally effective embodiments. [Brief description of the drawings]

[0012] [Figure 1] 1 shows a cross-sectional view of a rapid thermal processing chamber in accordance with some embodiments of the present principles. [Diagram 2] 1 shows a cross-sectional view of a wafer out of pocket, in accordance with some embodiments of the present principles; [Diagram 3] 1 shows a cross-sectional view of a rapid thermal processing chamber with a light-pipe pyrometer assembly in accordance with some embodiments of the present principles. [Figure 4] 1 shows a cross-sectional view of a light-pipe pyrometer assembly, in accordance with some embodiments of the present principles; [Diagram 5] 1 shows a side view of an optical assembly according to some embodiments of the present principles; [Figure 6] 1 shows a top view of a rapid thermal processing chamber with a light-pipe pyrometer assembly interfacing with a controller in accordance with some embodiments of the present principles. [Figure 7] 1 is a cross-sectional view of a light-pipe pyrometer assembly with a purge gas channel, in accordance with some embodiments of the present principles; [Figure 8] 1 is a cross-sectional view of a light-pipe pyrometer assembly illustrating purge gas flow, in accordance with some embodiments of the present principles. [Figure 9] FIG. 1 is an isometric view of a light pipe pyrometer assembly for a viewport, in accordance with some embodiments of the present principles. [Figure 10] FIG. 1 is an isometric view of a light-pipe pyrometer assembly with cooling channels, in accordance with some embodiments of the present principles. [Figure 11] FIG. 1 is an isometric view of a light-pipe pyrometer assembly with cooling channels, in accordance with some embodiments of the present principles. [Figure 12] 1 is a method for detecting the temperature of an assembly in a processing chamber, according to some embodiments of the present principles. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] For ease of understanding, the same reference numerals have been used, where possible, to designate identical elements that are common to several figures. The drawings are not drawn to scale and may be simplified for clarity. Elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.

[0014] The method and apparatus allows for measurements of internal process chamber assemblies, such as an edge ring, during wafer preheat. The method and apparatus advantageously minimizes temperature mismatch, such as between the wafer and the edge ring, in a rapid thermal processing (RTP) chamber. The reduced temperature mismatch during processing can be utilized to beneficially provide a solution to the Wafer Out Of Pocket (WOOP) problem in an RTP chamber. The method and apparatus also provide a cost-effective method for retrofitting existing chambers without requiring expensive and time-consuming modifications to the chamber bottom.

[0015] In some embodiments, a light pipe pyrometer assembly is used to collect infrared radiation from the internal assemblies of the processing chamber. The light pipe pyrometer assembly is completely resistant to wafer and / or process kit leakage and can utilize existing processing chamber viewports for inexpensive and simple installation, eliminating the need for expensive and time-consuming modifications to the bottom of the processing chamber. The light pipe pyrometer assembly can also be used to facilitate adjusting the set point of the feedback loop and aid in matching the temperature in the processing chamber. In some embodiments, the light pipe pyrometer assembly is used to measure the edge ring temperature in an RTP chamber, such as the Radiance® chamber manufactured by Applied Materials, Inc. of Santa Clara, Calif. The top surface of the edge ring receives strong radiation from heating lamps installed in the upper region of the processing chamber. Lamp radiation can introduce significant errors into the temperature measurements and / or saturation of pyrometer readings. The method and apparatus of the present principles provide a light pipe pyrometer assembly that is insensitive to lamp radiation and can also be used to adjust the set point for wafer preheat so that the temperature of the wafer can be controlled and matched to the temperature of the edge ring.

[0016] Although the following examples utilize an RTP chamber and edge ring, the method and apparatus of the present principles are not limited to only RTP chambers, and are not limited to only measuring edge ring temperature. The method and apparatus of the present principles may be used for other temperature measurements in other process chambers and assemblies within the process chamber. FIG. 1 shows an RTP chamber 100 with heat lamps 102 generating lamp radiation 104 toward a chamber body 106. The chamber body 106 includes an edge ring 108 and a wafer pyrometer 110. The wafer pyrometer 110 is used to determine the temperature of the wafer 112 from below the wafer 112. The wafer 112 and edge ring 108 are exposed to the lamp radiation 104 from above. The cross-sectional view 200A of FIG. 2 shows the wafer 112 in a preheated state, where the wafer 112 is lifted off the edge ring 108 by lift pins 202. In cross section 200B of Figure 2, the mismatch in temperature between the wafer 112 and the edge ring 108 causes the wafer 112 to fly off the edge ring 108 (a WOOP condition) when the wafer 112 is lowered onto the edge ring 108. The inventors have discovered that if the preheat temperature of the wafer 112 and the temperature of the edge ring 108 are similar, the bowing of the wafer 112 and the WOOP condition can be eliminated or reduced. If the temperature of the edge ring 108 is known during the preheat of the wafer 112, the temperature of the edge ring 108 can be used as a set point for the preheat temperature of the wafer 112 and the temperature mismatch is eliminated.

[0017] FIG. 3 is a cross-sectional view of a process chamber 300 including some embodiments of the present principles. A lamp radiation filtering window 302 is disposed between the heat lamps 102 and the chamber body 106. The lamp radiation filtering window 302 blocks the lamp radiation over a specific band of wavelengths to generate a filtered lamp radiation 304. In some embodiments, the lamp radiation filtering window 302 can be made of quartz with a high OH content, i.e., "wet quartz," configured to block the lamp radiation in a wavelength band of about 2.7 microns to about 2.8 microns. In some embodiments, the OH content of the quartz is about 1000 parts per million (ppm) or greater. In some embodiments, the OH content of the quartz is about 1000 ppm to about 1200 ppm. The inventors have found that the lamp radiation power loss in the filtered band has a low impact on the available heating power. The low effect is due to the lamp radiation power being concentrated in a shorter wavelength spectral range where the filtered band represents only about 15% of the spectral emission peak of the lamp radiation, and silicon wafer absorption is very low in the filtered band when the wafer is below about 500° C. A light pipe pyrometer assembly 306 sensitive to the blocked wavelength band is disposed between the lamp radiation filtering window 302 and the edge ring 108. The light pipe pyrometer assembly 306 is insensitive to the filtered lamp radiation 304 used to heat the wafer 112 and detects the edge ring radiation 308 in the filtered wavelength band. The inventors have found that by using a pyrometer that operates in the filtered spectral range, the pyrometer is not affected by the lamp radiation in the temperature measurement.

[0018] FIG. 4 illustrates a cross-sectional view 400 of a light pipe pyrometer assembly 402, according to some embodiments. The light pipe pyrometer assembly 402 includes a light pipe 404, an optical assembly 408, and a detector assembly 410. The light pipe 404 includes a first end 414 with a beveled surface 406 and a second end 416 distal to the first end 414 that interfaces with the optical assembly 408. In some implementations, the light pipe 404 can be a sapphire rod with a cut or beveled end. The beveled end is polished to internally reflect infrared radiation. In some embodiments, the beveled surface 406 is cut at an angle of about 45 degrees. In some embodiments, the light pipe 404 can have a diameter of about 2 millimeters. In some embodiments, the optical assembly 408 can include one or more aspheric condenser lenses and optical bandpass filters (see, e.g., FIG. 5). The optical assembly 408 provides wavelength selection and minimizes background radiation. The optical assembly 408 interfaces with a detector assembly 410 .

[0019] The detector assembly 410 converts the optical information into at least one signal that can be received by the temperature processing circuit 412. The inventors have found that in order to use the edge ring temperature in a feedback loop for wafer processing, the detection speed must be fast (e.g., about 100 Hz or faster). Most typical thermopile detectors are too slow to be used in feedback processing. The inventors have found that using a photovoltaic detector allows for fast temperature acquisition. If a detector is selected to function in the filtered band from about 2.7 microns to about 2.8 microns, typical photovoltaic detectors such as silicon photodiodes or indium gallium arsenide (InGaAs) diodes are not suitable for the range of the filtered band. The inventors have found that uncooled indium arsenide antimonide (InAsSb) or indium arsenide (InAs) photovoltaic detectors can be used. InAsSb detectors are typically utilized in the range from about 3 microns to about 5 microns. Uncooled detectors allow for simpler pyrometer designs (compact, no power supply required, etc.), while cooled detectors allow for lower range temperature detection. InGaAs detectors may still have a satisfactory response range in the filtered band from about 2.7 microns to about 2.8 microns. InAs detectors have a spectral response from about 1 micron to about 3.5 microns. Pyroelectric detectors may also be utilized.

[0020] The temperature processing circuit 412 converts the at least one signal into a temperature value that can be utilized by a process controller (see, e.g., FIG. 6). The temperature processing circuit 412 can be part of the light pipe pyrometer assembly 402 and / or part of the controller 606 (see FIG. 6). Infrared radiation 418 from the surface 420 of the edge ring 108 is received by the first end 414 of the light pipe 404, reflected by the beveled surface 406, and redirected down the length of the light pipe 404 to the optical assembly 408, where the infrared radiation is collimated and filtered before being focused onto the detector assembly 410.

[0021] FIG. 5 shows a side view 500 of the optical assembly 408 according to some embodiments. Infrared light 418 is directed down the light pipe 404 to the second end 416 of the light pipe 404 where it diverges onto the first aspheric condenser lens 502. An aspheric condenser lens is used because it collects more light than a normal lens, works with a wider diverging beam, and has a shorter focal length, allowing for a more compact design. The first aspheric condenser lens 502 can be made of sapphire or a molding compound. The inventors have found that for non-zero (Kelvin) ambient temperatures, which can be calculated by Planck's equation, the components inside the pyrometer always generate a small amount of thermal radiation. The calculated value is equivalent to a significant amount of background radiation around the operating wavelength, reducing the temperature accuracy. The temperature accuracy can be increased by using a lens material that is transparent over a wider spectral range than the detector's spectral range.

[0022] The light pipe 404 has a wide acceptance angle, and if directly coupled to the detector assembly 410, a significant band shift would occur in the bandpass filter due to the large cone angle 512 at the second end 416 of the light pipe 404. The first aspheric condenser lens 502 is used to collimate the widely diverging infrared radiation from the light pipe 404. The collimated infrared radiation sends the infrared radiation into the optical bandpass filter 504 at a non-varying angle of incidence, reducing the shift and increasing the filtering accuracy of the optical bandpass filter 504. The first aspheric condenser lens 502 has a higher numerical aperture (NA) and increases the infrared radiation collection power. The optical bandpass filter 504 filters the infrared 418 with minimal shift to a range of wavelengths. In some embodiments, the range of wavelengths passing through the optical bandpass filter 504 can be between about 2.7 microns and about 2.8 microns.

[0023] In some embodiments, when an InAs type detector is used, an optional silicon or germanium filter 506 with an anti-reflective coating 510 may be used to further suppress background lamp radiation. The inventors have found that bandpass filters do not have an ideal cutoff for wavelengths outside the bandpass region. Germanium has an absorption edge at about 1.6 microns to about 1.7 microns, and silicon has an absorption edge at about 1.1 microns, meaning that silicon becomes opaque below 1.1 microns and germanium becomes opaque below 1.6-1.7 microns. The optional silicon or germanium filter 506 can be used to further suppress undesired lamp radiation wavelengths, further protecting the detector assembly 410. Silicon and germanium are highly reflective and cause significant light loss. The anti-reflective coating 510 reduces reflections at the bandpass wavelengths (e.g., about 2.7 microns to about 2.8 microns). The infrared light 418 is then focused onto the detector assembly 410 by a second aspheric condenser lens 508. The second aspheric condenser lens 508 may be made of sapphire or a molded compound. The inventors have found that for longer wavelength detectors, a housing having an aluminum alloy with a polished interior may be used to reduce heat radiation from the housing and increase temperature accuracy.

[0024] FIG. 6 shows a top view 600 of an RTP chamber 602 with a light-pipe pyrometer assembly 604 that interfaces with a controller 606, according to some embodiments. The RTP chamber 602 has a slit port 608 for inserting and removing a wafer 618, a gas exhaust 610 for removing gases during wafer processing, a first viewport 612 used to view the wafer 618, and a second viewport 614 converted for use with the light-pipe pyrometer assembly 604. The light-pipe pyrometer assembly 604 can be easily retrofitted into the second viewport 614. The light-pipe pyrometer assembly 604 does not require expensive chamber bottom modifications to read the temperature of the edge ring 616. The light-pipe pyrometer assembly 604 interfaces with the controller 606 through a temperature processing circuit 620 and / or may interface directly with the controller 606 (not shown). In some embodiments, the light pipe pyrometer assembly 604 may also interface with a purge gas supply 622 that provides a purge gas to flush contaminants from around the light pipe. In some embodiments, the light pipe pyrometer assembly 604 may also interface with a liquid coolant supply 624 to help reduce thermal stray radiation from the light pipe pyrometer assembly 604 that interferes with the light pipe transmission of infrared radiation. In some embodiments, the liquid coolant may be water, or the like.

[0025] The controller 606 controls the operation of the RTP chamber 602 using direct control of the RTP chamber 602 or, alternatively, by controlling a remote computer (or controller) associated with the RTP chamber 602. During operation, the controller 606 allows for data collection and feedback from the RTP chamber 602 and / or other systems to optimize the performance of the RTP chamber 602. The controller 606 generally includes a central processing unit (CPU) 626, a memory 628, and support circuits 630. The CPU 626 may be any form of general-purpose computer processor available in an industrial setting. The support circuits 630 are conventionally coupled to the CPU 626 and may include cache, clock circuits, input / output subsystems, power supplies, etc. Software routines, such as the methods described above, are stored in the memory 628 and, when executed by the CPU 626, transform the CPU 626 into a special purpose computer (controller 606). The software routines may also be stored and / or executed by a second controller (not shown) located remotely from the RTP chamber 602.

[0026] The memory 628 is a form of computer-readable storage medium that includes instructions that, when executed by the CPU 626, facilitate the operation of semiconductor processes and equipment. The instructions in the memory 628 are in the form of a program product, such as a program that implements the methods of the present principles. 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 of the program product defines the functions of the aspects (including the methods described herein). Exemplary computer-readable storage media include, but are not limited to, non-writable storage media in which information is permanently stored (e.g., read-only memory devices in a computer such as a CD-ROM drive, a flash memory, a ROM chip, or a CD-ROM disk that can be read by any type of solid-state non-volatile semiconductor memory), and writeable storage media in which changeable information is 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 aspects of the present principles.

[0027] In order to have good accuracy in temperature measurements, the inventors have found that the light pipe needs to be kept clean. In certain applications, outgassing can occur, resulting in deposition on the light pipe surface that affects temperature measurements. The inventors have found that by using a closed-end sheath with a small opening on the bottom side of the sheath to receive infrared radiation, the light pipe can be purged with a purge gas to keep it clean during use. FIG. 7 is a cross-sectional view 700 of a light pipe pyrometer assembly 702 having a purge gas channel 704 with a purge gas port 730 in a sheath 712 that surrounds a light pipe 714, according to some embodiments. In some embodiments, the sheath 712 is formed of an aluminum alloy, such as 6061. After machining, the sheath 712 is handled carefully to avoid damaging the protective native oxide layer that forms on the surface of the sheath 712. The outer surface of the sheath 712 is then masked, while the inner surface is hard anodized. The outer surface has low emissivity, so heat absorption is low. The inner surface has a lower reflectivity, thereby reducing background stray radiation and improving temperature accuracy.

[0028] In some embodiments, the light pipe pyrometer assembly 702 is configured to be retrofitted into the viewport of the RTP chamber 706 and extend over an edge ring 708 on the chamber body assembly 710. The sheath 712 includes an opening 716 that allows infrared radiation 720 from the edge ring 708 to reach a first end 718 of the light pipe 714. The sheath 712 covers the first end 718 of the light pipe 714 to prevent light leakage forward into the light pipe 714 and increase the accuracy of the temperature measurement. A bevel 722 on the first end 718 of the light pipe 714 redirects the infrared radiation 720 to an optical assembly 724 at a second end 726 of the light pipe 714, distal from the first end 718 of the light pipe 714. The infrared radiation 720 then passes from the optical assembly 724 to a detector assembly 728. The detector assembly 728 then sends at least one signal representative of the infrared radiation 720 to a temperature processing circuit (not shown, see, e.g., FIG. 4, temperature processing circuit 412, and FIG. 6, temperature processing circuit 620). In some embodiments, the purge gas channel 704 extends from the purge gas port 730 to an opening 716 in the first end 718 of the light pipe 714. In some embodiments, the purge gas channel 704 extends completely around the entire length of the light pipe 714 from the first end 718 to the second end 726. The purge gas channel 704 allows a purge gas, for example, an inert gas such as, but not limited to, dry nitrogen, to flow over the light pipe 714 to aid in removing contaminants from around the light pipe 714 that would reduce the accuracy of the light pipe pyrometer assembly 702.

[0029] 8 is a cross-sectional view 800 of a light pipe pyrometer assembly 702 showing a purge gas flow 802 according to some embodiments. As the purge gas enters the purge gas port 730, it flows around the light pipe 714 through the purge gas channel 740 and then through the opening 716 into the RTP chamber (not shown). The purge gas flow 802 may cause a slight temperature drop on a portion 806 of the surface 804 of the edge ring 708 as it exits the opening 716 in the sheath 712. In some embodiments, because the edge ring 708 is rotating, the cooling effect on the edge ring 708 is minimal and not localized. The purge gas flow 802 is kept at a low rate, such as, for example, about 10 to about 1000 sccm (standard cubic centimeters per minute), to reduce undesirable cooling effects on the edge ring 708.

[0030] 9 is an isometric view 900 of a light-pipe pyrometer assembly 902 for a viewport 904 of an RTP chamber assembly 906, according to some embodiments. The light-pipe pyrometer assembly 902 has a sheath extension 908 that houses a light pipe, a purge gas channel, and an opening for exhausting the purge gas and receiving infrared radiation from the edge ring. A sheath body 910 further contains the light pipe and purge channel and distributes the purge gas from a purge gas port 914 in a flange 912. The sheath body 910 can also provide an internal cooling channel for cooling the light-pipe pyrometer assembly 902 with liquid cooling provided at a coolant port 916 in the flange 912. The light-pipe pyrometer assembly 902 includes connection points 918 to allow the light-pipe pyrometer assembly 902 to interface with other components to relay temperature information received from the edge ring. 10 is an isometric view 1000 of a light pipe pyrometer assembly 902 with a coolant channel 1008, according to some embodiments. In some embodiments, the coolant channel 1008 can be formed in a lower portion 1010 of a sheath body 910 along with a first purge gas channel portion 1006. An upper portion 1002 of the sheath body 910 provides a cover to the lower portion 1010 to enclose the coolant channel 1008.

[0031] 11 is an isometric view 1100 of a light-pipe pyrometer assembly 902 having a first coolant channel 1102, a second coolant channel 1104, and a third coolant channel 1106, according to some embodiments. In some embodiments, the first coolant channel 1102 and the second coolant channel 1104 may be formed by drilling longitudinally through the sheath body 910 and through the flange 912 to form a longitudinal coolant channel that connects to a coolant port 916 in the flange 912. The third coolant channel 1106 is formed by drilling the sheath body 910 orthogonally to the first coolant channel 1102 and the second coolant channel 1104, such that the third coolant channel 1106 intersects with the first coolant channel 1102 and the second coolant channel 1104 to form a single coolant pathway between the coolant ports 916A, 916B. A first plug 1108 is inserted into an end 1120 of the first coolant channel 1102 distal from the coolant port 916A. A second plug 1110 is inserted into an end 1122 of the second coolant channel 1104 distal from the coolant port 916B. A third plug 1112 is inserted into a first end 1116 of the third coolant channel 1106, and a fourth plug 1114 is inserted into a second end 1118 of the third coolant channel 1106. A first portion 1126 of the purge gas channel is formed by drilling vertically through a portion of the flange 912. A second portion 1124 of the purge gas channel is formed by drilling horizontally through the sheath body 910 until the second portion 1124 intersects with an end 1128 of the first portion 1126 distal to the purge gas port 914.

[0032] FIG. 12 is a method 1200 of detecting the temperature of an assembly in a processing chamber according to some embodiments. In block 1202, the lamp radiation is filtered to block wavelengths from about 2.7 microns to about 2.8 microns. In some embodiments, wet quartz with an OH content of about 1000 ppm to about 1200 ppm or more can be used to filter the lamp radiation. In block 1204, infrared radiation is detected from a surface of the assembly inside the processing chamber in the quartz absorption band through a light pipe. In some implementations, the light pipe is made of sapphire. In some embodiments, the infrared radiation is detected by a light pipe covered with a sheath having an open end that allows the infrared radiation to be detected by the light pipe. In some embodiments, the light pipe can have a bevel at one end that redirects the infrared radiation down the length of the light pipe. In block 1206, contaminants around the light pipe are removed by flowing a purge gas over and around the light pipe during absorption of infrared radiation from the assembly. At block 1208, the light pipe housing is cooled with a liquid coolant to facilitate reducing stray heat radiation caused by thermal radiation from the light pipe housing. At block 1210, the infrared radiation from the light pipe is collimated using a first aspheric condenser lens. In some embodiments, the first aspheric condenser lens can be made from sapphire or from a molded material. At block 1212, the infrared radiation is then filtered with an optical bandpass filter. In some embodiments, the optical bandpass filter passes wavelengths from about 2.7 microns to about 2.8 microns. At block 1214, the infrared radiation is optionally filtered by using a germanium filter with an anti-reflective coating to further filter unwanted wavelengths. At block 1216, the infrared radiation is focused onto an optical detector with a second aspheric condenser lens. In some implementations, the second aspheric condenser lens can be made from sapphire or from a molded material. At block 1218, a temperature value is generated from the infrared radiation.In some embodiments, the optical detector may convert the infrared radiation into at least one signal representative of the infrared radiation. The at least one signal may then be processed by a temperature processing circuit to convert the at least one signal into a temperature value. The temperature value may then be passed to a controller for use in controlling a process or the like in a processing chamber.

[0033] Embodiments according to the present principles may be implemented in hardware, firmware, software, or any combination thereof. Embodiments may also be implemented as instructions stored using one or more computer-readable media, which may be read and executed by one or more processors. A computer-readable medium may include any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computing platform or a "virtual machine" running on one or more computing platforms). For example, a computer-readable medium may include any suitable form of volatile or non-volatile memory. In some embodiments, a computer-readable medium may include a non-transitory computer-readable medium.

[0034] While the forgoing is directed to embodiments of the present principles, other and further embodiments of the present principles may be devised without departing from the basic scope thereof.

Claims

1. 1. An apparatus for measuring a temperature inside a processing chamber, comprising: a lamp radiation filtering window configured to be disposed between a lamp radiation source and a light pipe, the lamp radiation filtering window, the lamp radiation source, and the light pipe being inside the process chamber; the light pipe having a first end with a bevel configured to redirect infrared radiation through the light pipe and having a second end distal to the first end; an optical assembly configured to collimate, filter, and focus the infrared radiation from the second end of the light pipe; a housing enclosing the light pipe and at least a portion of the optical assembly, the housing comprising liquid cooling channels configured to flow a coolant to reduce background thermal radiation; an optical detector configured to receive output from the optical assembly and generate at least one signal representative of the infrared radiation; a temperature circuit for converting said at least one signal into a temperature value; An apparatus comprising:

2. An apparatus for measuring a temperature inside a process chamber, comprising: a lamp radiation filtering window configured to be disposed between a lamp radiation source and a light pipe, the lamp radiation filtering window, the lamp radiation source, and the light pipe being inside the process chamber; the light pipe having a first end with a bevel configured to redirect infrared radiation through the light pipe and having a second end distal to the first end; an optical assembly configured to collimate, filter, and focus the infrared radiation from the second end of the light pipe; an optical detector configured to receive output from the optical assembly and generate at least one signal representative of the infrared radiation; a temperature circuit for converting said at least one signal into a temperature value; Equipped with An apparatus, wherein the lamp radiation filtering window is made of a wet quartz material that absorbs radiation having a wavelength from about 2.7 microns to about 2.8 microns.

3. 3. The apparatus of claim 2, wherein the wet quartz has an OH content of about 1000 parts per million (ppm) to about 1200 ppm.

4. The apparatus of claim 1 , wherein the light pipe is made of a sapphire material.

5. The apparatus of claim 1 , wherein the beveled surface has an angle of approximately 45 degrees.

6. a sheath configured to surround the light pipe while providing an opening at the first end of the light pipe configured to allow infrared radiation into the light pipe, the sheath including a purge channel configured to flow a purge gas around the light pipe to reduce contamination of the light pipe; The apparatus of claim 1 further comprising:

7. The apparatus of claim 1 , wherein the optical assembly includes a first aspheric condenser lens, an optical bandpass filter, and a second aspheric condenser lens.

8. 8. The apparatus of claim 7, wherein the optical assembly further comprises a germanium lens with an anti-reflective coating interposed between the first aspheric condenser lens and the second aspheric condenser lens.

9. 1. An apparatus for measuring a temperature inside a processing chamber, comprising: a light pipe configured to be disposed within the processing chamber, a lamp radiation filtering window within the processing chamber being disposed between the light pipe and a lamp radiation source within the processing chamber, the light pipe having a first end with a bevel configured to redirect infrared radiation through the light pipe and having a second end distal to the first end; an optical assembly configured to collimate, filter, and focus the infrared radiation from the second end of the light pipe; a housing enclosing the light pipe and at least a portion of the optical assembly, the housing having liquid cooling channels for flowing a coolant to reduce background thermal noise; an optical detector configured to receive output from the optical assembly and generate at least one signal representative of the infrared radiation; a temperature circuit for converting said at least one signal into a temperature value; An apparatus comprising:

10. An apparatus for measuring temperature inside a process chamber, comprising: a light pipe configured to be disposed within the processing chamber, a lamp radiation filtering window within the processing chamber being disposed between the light pipe and a lamp radiation source within the processing chamber, the light pipe having a first end with a bevel configured to redirect infrared radiation through the light pipe and having a second end distal to the first end; an optical assembly configured to collimate, filter, and focus the infrared radiation from the second end of the light pipe; an optical detector configured to receive output from the optical assembly and generate at least one signal representative of the infrared radiation; a temperature circuit for converting said at least one signal into a temperature value; Equipped with The apparatus, wherein the light pipe is configured to detect radiation having a wavelength from about 2.7 microns to about 2.8 microns.

11. The apparatus of claim 9 , wherein the light pipe is made of a sapphire material.

12. 10. The apparatus of claim 9, wherein the light pipe has a diameter of approximately 2 millimeters.

13. The apparatus of claim 9 , wherein the beveled surface has an angle of approximately 45 degrees.

14. a sheath configured to surround the light pipe while providing an opening at the first end of the light pipe configured to allow infrared radiation into the light pipe. The apparatus of claim 9 further comprising:

15. 15. The apparatus of claim 14, wherein the sheath comprises a purge channel configured to flow a purge gas around the light pipe to reduce contamination of the light pipe.

16. 10. The apparatus of claim 9, wherein the optical assembly includes a first aspheric condenser lens, an optical bandpass filter, and a second aspheric condenser lens.

17. 17. The apparatus of claim 16, wherein the optical assembly further comprises a germanium filter with an anti-reflective coating.

18. 1. An apparatus for measuring a temperature inside a processing chamber, comprising: a light pipe configured to be disposed within the processing chamber, a lamp radiation filtering window within the processing chamber being disposed between the light pipe and a lamp radiation source within the processing chamber, the light pipe having a first end with a bevel configured to redirect infrared radiation through the light pipe and having a second end distal to the first end; an optical assembly configured to collimate, filter, and focus the infrared radiation from the second end of the light pipe; a housing enclosing the light pipe and at least a portion of the optical assembly, the housing comprising liquid cooling channels configured to flow a coolant to reduce background thermal radiation; an optical detector configured to receive output from the optical assembly and generate at least one signal representative of the infrared radiation; a temperature circuit for converting the at least one signal into a temperature value; a controller configured to receive the temperature values ​​and adjust one or more processes in the processing chamber based on the temperature values; An apparatus comprising:

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