WO2010037787A1 - High temperature-resistant narrow band optical filter - Google Patents

High temperature-resistant narrow band optical filter Download PDF

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Publication number
WO2010037787A1
WO2010037787A1 PCT/EP2009/062702 EP2009062702W WO2010037787A1 WO 2010037787 A1 WO2010037787 A1 WO 2010037787A1 EP 2009062702 W EP2009062702 W EP 2009062702W WO 2010037787 A1 WO2010037787 A1 WO 2010037787A1
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Prior art keywords
window
narrow band
layers
substrate
alternating layers
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PCT/EP2009/062702
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French (fr)
Inventor
Ian George Sayce
Olivier Selles
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Heraeus Quartz Uk Limited
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Publication of WO2010037787A1 publication Critical patent/WO2010037787A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
    • H01L21/67005—Apparatus not specifically provided for elsewhere
    • H01L21/67011—Apparatus for manufacture or treatment
    • H01L21/67098—Apparatus for thermal treatment
    • H01L21/67115—Apparatus for thermal treatment mainly by radiation
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J5/00—Radiation pyrometry, e.g. infrared or optical thermometry
    • G01J5/0003—Radiation pyrometry, e.g. infrared or optical thermometry for sensing the radiant heat transfer of samples, e.g. emittance meter
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J5/00—Radiation pyrometry, e.g. infrared or optical thermometry
    • G01J5/0003—Radiation pyrometry, e.g. infrared or optical thermometry for sensing the radiant heat transfer of samples, e.g. emittance meter
    • G01J5/0007—Radiation pyrometry, e.g. infrared or optical thermometry for sensing the radiant heat transfer of samples, e.g. emittance meter of wafers or semiconductor substrates, e.g. using Rapid Thermal Processing
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J5/00—Radiation pyrometry, e.g. infrared or optical thermometry
    • G01J5/02—Constructional details
    • G01J5/08—Optical arrangements
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J5/00—Radiation pyrometry, e.g. infrared or optical thermometry
    • G01J5/02—Constructional details
    • G01J5/08—Optical arrangements
    • G01J5/0801—Means for wavelength selection or discrimination
    • G01J5/0802—Optical filters
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J5/00—Radiation pyrometry, e.g. infrared or optical thermometry
    • G01J5/02—Constructional details
    • G01J5/08—Optical arrangements
    • G01J5/0875—Windows; Arrangements for fastening thereof
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/20—Filters
    • G02B5/28—Interference filters
    • G02B5/281—Interference filters designed for the infrared light
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/20—Filters
    • G02B5/28—Interference filters
    • G02B5/285—Interference filters comprising deposited thin solid films
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B7/00—Mountings, adjusting means, or light-tight connections, for optical elements
    • G02B7/008—Mountings, adjusting means, or light-tight connections, for optical elements with means for compensating for changes in temperature or for controlling the temperature; thermal stabilisation
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
    • H01L21/67005—Apparatus not specifically provided for elsewhere
    • H01L21/67242—Apparatus for monitoring, sorting or marking
    • H01L21/67248—Temperature monitoring

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  • General Physics & Mathematics (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Engineering & Computer Science (AREA)
  • Optics & Photonics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • Manufacturing & Machinery (AREA)
  • Computer Hardware Design (AREA)
  • Microelectronics & Electronic Packaging (AREA)
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Abstract

A window (108) includes a substrate, and alternating layers of first material and second material on a side of the low refractive index substrate. The refractive index of the first material is greater than the refractive index of the second material. The alternating layers of first material and second material are effective to block a narrow band of infrared radiation. The narrow band extends over a range of less than about 800 nm.

Description

HIGH TEMPERATURE-RESISTANT NARROW BAND OPTICAL FILTER
FIELD OF THE DISCLOSURE [0001] This disclosure, in general, relates to high temperature narrow band optical filters.
BACKGROUND
[0002] Single-wafer rapid thermal processing (RTP) of semiconductors provides a powerful and versatile technique for fabrication of integrated circuits. Typical RTP systems employ a heat source consisting of an array of tungsten halogen lamps. IR/visible radiation from the heat source can pass through a thin window of fused quartz to heat the semiconductor wafer. Generally, visible radiation has a wavelength of between 380 nm and 750 nm and IR radiation have a wavelength range above 750 nm. Optical pyrometers are used to measure the temperature of the semiconductor wafer, and the output of the heat source can be controlled to regulate the temperature of the semiconductor wafer. The optical pyrometers can determine the wafer temperature from the intensity of radiation emitted by the wafer at a particular wavelength, typically between about 800 nm to about lOOOnm. However, stray radiation from sources other than the wafer, such as the tungsten halogen lamps for example by transmission through the silicon wafer, can introduce errors in the measurement of the wafer temperature.
[0003] Several approaches have been proposed to avoid or reduce stray radiation from the lamps. Ramaswamy et al. (US Pub. 2006/0260545) utilizes an array of diode lasers having a wavelength of 810 nm to heat the wafer and incorporates an optical filter into the pyrometer to block the wavelength of radiation produced by the lasers. However, this approach is not effective when using an array of lamps emitting a broad range of wavelengths that overlaps the wavelength used by the detector.
[0004] Adams et al. (US Pub. 2006/0102607) utilizes a wavelength-responsive optical element to combine the path for delivering radiation from a laser source to the wafer and for delivering black-body radiation from the wafer to a pyrometer. This is accomplished by using a wavelength-selective mirror that reflects the wavelength of the radiation produced by the laser and transmits the wavelength of radiation used by the pyrometer. Additionally, a notch filter can be placed between the laser source and the wavelength responsive optical element to reduce radiation at the pyrometer wavelength that is emitted by the laser.
[0005] The use of laser heating is however limited to applications where it is intended to provide transient heating of only the upper surface layers of the wafer for a brief period, as for example in flash annealing. The majority of RTP reactors are used in applications where it is required to heat the entire body of the wafer to a substantially uniform temperature over a significant period of time. These typically employ tungsten halogen lamps, and subject the equipment to high temperatures and repeasted thermal cycling.
[0006] Peuse et al. (Peuse et al. Mat. Res. Symp. Proc. Vol. 525, 1998, pp. 71-85) describes a type of RTP reactor in which the wafer is heated from above by an array of tungsten halogen lamps, and the wafer temperature is monitored using pyrometers connected to fiber optic probes beneath the wafer and directed at the underside thereof. The pyrometers can utilize wavelengths in the range of about 800 nm to about 1000 nm to measure the temperature of the underside of the wafer. At high temperatures, such as about 6000C, the wafer becomes opaque to wavelengths below about 1000 nm and the pyrometer can receive only the black-body radiation emitted by the wafer, resulting in an accurate temperature measurement. However, at lower temperatures, such as below about 4000C, the wafer can be partially transparent to wavelengths used and radiation from the lamps can therefore pass through the wafer and interfere with the temperature measurements. Accordingly, low temperature measurements are subject to inaccuracies. This approach can utilize optical filters placed between the pyrometers and the wafer to limit the range of wavelengths received by the pyrometers, such as by blocking wavelengths above and below the range of about 800 nm to about 1000 nm. However, this technique does not eliminate errors due to transmission through the wafer of radiation in the wavelength region being used for pyrometry. [0007] Hunter et al. (US Pat. 7,112,763) describes an RTP reactor in which an array of tungsten halogen lamps heats the upper surface of the wafer, and in which a transmission pyrometer and a radiation pyrometer are used to determine the temperature of the underside of the wafer at high and low temperatures. At low temperatures, radiation in the range of 1000 nm to 1200 nm passes through the wafer and can be measured by the transmission pyrometer. The transmittance of the wafer in this range is temperature dependent and can be used to determine the wafer temperature. At high temperatures, the wafer becomes opaque in this range, and the radiation pyrometer can determine the temperature based on the black-body radiation from the wafer without interference from the lamps. The complex design can suffer from inaccuracies at the transition between using the transmission pyrometer and the radiation pyrometer. At the transition, neither the radiation transmitted by the wafer nor the black-body radiation emitted by the wafer may be sufficient for an accurate temperature measurement.
SUMMARY
[0008] In an embodiment, a window can include a substrate, and alternating layers of first material and second material on a side of the low refractive index substrate. The refractive index of the first material can be greater than the refractive index of the second material. The alternating layers of first material and second material can be effective to block a narrow band of infrared radiation. The narrow band can extend over a range of less than about 800 nm, such as less than about 500 nm. In a particular embodiment, the substrate can have a %transmission between 500 nm and 2500 nm of greater than about 85%.
[0009] In another embodiment, a method of forming a semiconductor can include providing a silicon wafer, applying infrared and visible radiation through a window made of quartz glass or alternative transmissive material to the silicon wafer to heat the silicon wafer, measuring the infrared radiation emitted by the silicon wafer, and determining the temperature of the silicon wafer. The window can include a substrate and alternating layers of a first material and a second material on a side of the optically transmissive quartz substrate. The refractive index of the first material can be greater than the refractive index of the second material. The alternating layers of the first material and the second material can be effective to block a narrow band of infrared radiation. The narrow band can extend over a range of less than about 800 nm, such as less than about 500 nm. In an example, measuring the infrared radiation can include measuring the infrared radiation at a wavelength of about 1000 nm. In a particular embodiment, the substrate can be quartz glass, fused quartz, synthetic quartz, synthetic fused quartz, vitreous silica, synthetic vitreous silica, fused silica, synthetic fused silica, or any combination thereof.
[0010] In an example, the window can have a selectivity (as defined below) of at least about 3.0, such as at least about 5.0, particularly at least about 8.0. In a further example, the window can have a reduction in transmission at a target wavelength of at least about 50%, such as at least about 55%, preferably at least about 60%. In a particular example, the reduction in transmission at the target wavelength can be at least about 65%, such as at least about 70%. In another example, the window can withstand temperatures up to at least about 4000C, such as at least about 5000C, particularly at least about 6000C. In yet another example, the narrow band of radiation can include wavelengths between about 900 nm and about 1200 nm.
[0011] In another example, the substrate can include the second material. In yet another example, the first and second materials can have a difference in refractive index of at least about 0.3, such as at least about 0.5. In a further example, the first material can include oxides of Al, Nb, Ta, Ti, V, Zr, or any combination thereof. In yet another example, the first material can include refractory carbides, oxycarbides, nitrides, oxynitrides, metals, or any combination thereof. In yet another example, the first and second material can include at least two oxides. Further, the oxides can include TiO2, ZrO2, Ta2O5, ZnO, SiO2, Al2O3, Nb2O5, BaTiO3, SnO2, In2O3, or any combination thereof. In a particular example, the second material includes SiO2, and the first material has a refractive index at 1000 nm of at least about 1.6, such as between about 1.8 and about 2.6, particularly between about 1.9 and about 2.4. In a more particular example, the first material can include Si3N4. [0012] In yet another example, the alternating layers can include at least three layers of the first material and at least three layers of the second material, such as at least seven layers of the first material and at least seven layers of the second material.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The present disclosure may be better understood, and its numerous features and advantages made apparent to those skilled in the art by referencing the accompanying drawings.
[0014] FIG. 1 is a schematic diagram illustrating an exemplary rapid thermal processing (RTP) system.
[0015] FIG. 2 shows the calculated spectral distribution of a tungsten filament at a temperature of about 2500 K.
[0016] FIG. 3 is a spectral plot showing the optical transmission of a quartz substrate having a 6-layer interference filter of SiO2 and Si3N4 on each side.
[0017] FIG. 4 is a spectral plot showing the optical transmission of a quartz substrate having a 14-layer interference filter of SiO2 and Si3N4 on each side.
[0018] FIG. 5 is a calculated spectral plot showing the IR/Visible radiation received by a wafer in a RTP system having either a 6-layer or 14-layer interference filter.
[0019] The use of the same reference symbols in different drawings indicates similar or identical items.
DETAILED DESCRIPTION
[0020] As semiconductor manufacturing technology advances, it is becoming increasingly important to monitor and control the wafer temperature throughout the operational temperature range, and the precision of temperature measurements at the low end of this range, in RTP reactors employing tungsten halogen heating lamps, would be greatly enhanced if it were possible to eliminate or substantially reduce the radiation transmitted by the wafer in the region of sensitivity of the pyrometers. One method of achieving this end would be to reduce the intensity of the incident radiation within this wavelength range which reaches the upper surface of the wafer, for example by placing a suitable narrow band filter between the heating lamps and the wafer. However, any such filter must be capable of withstanding repeated thermal cycling up to relatively high temperatures without significant change in optical characteristics, or mechanical deterioration, such as spalling or shedding of particles.
[0021] According to an embodiment, a window can include a substrate and alternating layers of a first material and a second material on a side of the substrate. The substrate can be a high purity metal oxide, such as optically transmissive quartz (SiO2) or sapphire (AI2O3). As used herein, optically transmissive quartz can include quartz glass, synthetic quartz, fused quartz, synthetic fused quartz, fused silica, synthetic fused silica, vitreous silica, synthetic vitreous silica, or any combination thereof.
[0022] The substrate can have an impurity content of less than about 1.0 wt%, preferably not greater than about 0.1 wt%, such as not greater than about 0.01 wt%. In an example, high purity silica can include at least about 99.0 wt% SiO2, such as at least about 99.9 wt% SiO2, or even 99.99 wt% SiO2. In another example, high purity aluminum oxide can include at least about 99.0 wt% Al2O3, such as at least about 99.9 wt% Al2O3, or even 99.99 wt% Al2O3. Impurities are defined as contaminates and undesirable or unintentional species contained within the substrate. For applications such as semiconductor processing, impurities that are to be restricted include metals, particularly alkali metals, such as sodium, which may migrate either to reduce the performance of the interference filter, or otherwise contaminate the wafer being processed.
[0023] In an example, the substrate can have a thickness not less than about lmm, and generally not greater than about 10 mm. The refractive index of the first material can be greater than the refractive index of the second material. In an embodiment, the substrate and the first and second materials can be capable of withstanding temperatures of at least about 4000C, such as at least about 5000C, preferably at least about 6000C. In an embodiment, the alternating layers of the first material and the second material can be effective to block a narrow band of infrared radiation extending over a range of less than about 800 nm. Blocking herein is defined by reducing the %transmission of the substrate such that the ratio (Tc/Tu) of the %transmission of the coated substrate (Tc) to the %transmission of the uncoated substrate (T11) is not greater than about 0.5.
[0024] Alternating layers of the first material and the second material can form an interference filter. The interference filter can act to reflect the narrow band while allowing other wavelengths to pass through the window. The narrow band of wavelengths reflected by the interference filter depends on the number and thickness of the layers and the refractive index of the first material and the second material.
[0025] Certain embodiments of interference filter designs offer high selectivity. Selectivity herein is defined as (Thigh+Tiow)/(2*Tcut), where Thigh is the average transmittance for wavelengths above the narrow band and below 2500 nm, Tiow is the average transmittance for wavelengths below the narrow band and above 500 nm, and Tcut is the average transmittance for wavelengths within the narrow band.
[0026] Additionally, the filter structure can have a target attenuation wavelength (WTA). The WTA can be the wavelength having the maximum reduction of radiation transmission. Reduction of radiation transmission (RT) herein is defined as 1-TC/TU, where Tc is the transmission of the coated substrate and T11 is the transmission of the uncoated substrate, at a given wavelength. The RT at the WTA can be at least about 50%, such as at least about 55%, particularly at least about 60%. In a further embodiment, the RT at the WTA can be at least about 65%, such as at least about 70%.
[0027] The effectiveness of the interference filter, as measured either by the selectivity or the RT at the WTA, depends on the difference in the refractive index between the first material and the second material and the thickness and number of layers of the interference filter. For example, increasing the difference in the refractive index or increasing the number of layers can increase the effectiveness of the interference filter. However, it has been found that the overall thickness of the total stack can affect the durability of the window on repeated thermal cycling, and accordingly the increasing thickness associated with a large number of layers has a practical upper limit such as a total thickness of less than about 200 microns, such as less than about 100 microns, particularly less than about 50 microns. In an embodiment, the total thickness can be less than about 20 microns, such as less than about 10 microns.
[0028] In an embodiment, the first material can include oxides of Al, Nb, Si, Ta, Ti, V, Zr, or any combination thereof. Additionally, the first material can include other refractory materials, such as carbides, oxycarbides, nitrides, oxynitrides, and metals. In an embodiment, multiple high refractive index layers can each include different high refractive index materials.
[0029] In another embodiment, the first and second materials can include oxides, such as TiO2, ZrO2, Ta2O5, ZnO, SiO2, Al2O3, Nb2O5, BaTiO3, SnO2, In2O3, or any combination thereof. In yet another embodiment, the first and second materials can have a difference in the refractive index of at least about 0.3, such as at least about 0.5. For example, the second material can include SiO2, and the first material can include an material having a refractive index at 1000 nm of higher than about 1.6, such as between about 1.8 and about 2.6, particularly between about 1.9 and about 2.4. In one embodiment, the first material can include Si3N4, and the second material can include SiO2.
[0030] In an embodiment where the window undergoes repeated thermal cycling such as RTP, it is important to minimize the stresses in the coating. Additionally, the optical properties of the materials need to remain substantially constant with rising temperature and the materials need to be structurally similar to avoid cracking and flaking with time and repeated thermal cycling.
[0031] The layers of refractory material can be applied to the substrate using chemical vapor deposition, evaporation, sputtering, sol-gel, or other techniques known in the art. Chemical vapor deposition can be accomplished at raised, ambient, or low pressure. Additionally, chemical vapor deposition can include plasma-enhanced chemical vapor deposition. [0032] FIG. 1 illustrates an exemplary RTP system, generally designated 100. The RTP system 100 can include radiant heat source 102 and a wafer processing chamber 104. The radiant heat source 102 can include an array of tungsten halogen lamps 106 and a quartz window 108. FIG. 2 shows the calculated spectral distribution for tungsten halogen lamps 160 at 2500 K. It is evident that the radiation emitted by such lamps has a peak in intensity in a region of potential transmission of the wafer, and which may also be of interest for optical pyrometry as used for temperature measurement. Returning to FIG. 1, the quartz window 108 can include an interference filter including alternating layers of first material and second material as previously described. The wafer processing chamber 104 can include a wafer support ring 110 on a rotating cylinder 112 and a reflector plate 114. Additionally, fiber optic probes 116 can be located through the reflector plate 114. The fiber optic probes 116 can be coupled to optical pyrometers (not shown) for measurement of the wafer temperature.
[0033] Radiant energy, including IR and visible radiation, produced by the tungsten halogen lamps 106 can pass through the quartz window 108. Because of the incorporated interference filter the quartz window 108 can substantially block a narrow range of wavelengths, such as between 800 nm and 1000 nm, so that substantially only wavelengths outside of the narrow range can pass through the quartz window 108. The radiant energy passing through the quartz window 108 can be absorbed by a wafer supported by the wafer support ring 110. Rotation of the rotating quartz cylinder 112 can cause the wafer support ring 110 and the wafer to rotate, averaging out local variations in the intensity of the radiant energy. Additionally, the rotating opaque cylinder 112 and the wafer support ring 110 serve to block stray radiation from reaching the fiber optic probes 116.
[0034] As the wafer is heated, the wafer emits black-body radiation. The reflector plate can reflect a substantial percentage of the black-body radiation back to the wafer, reducing thermal loss. Additionally, fiber optic probes 116 collect a portion of the black- body radiation emitted by the wafer, such as within the filter range (e.g. 800-1000 nm), and transport the radiation to optical pyrometers for measurement of the wafer temperature. The output of the optical pyrometers can be used for control of the lamp output to regulate the temperature of the wafer.
[0035] In another particular embodiment, a method of forming a semiconductor can include providing a silicon wafer, applying infrared and visible radiation through a quartz window to the silicon wafer to heat the silicon wafer, measuring the infrared radiation emitted by the silicon wafer, and determining the temperature of the silicon wafer. The quartz window can include a optically transmissive quartz substrate and alternating layers of first material and second material on a side of the optically transmissive quartz substrate. The alternating layers of first material and second material can be effective to block a narrow band of infrared radiation. The narrow band can extend over a range of less than about 800 nm.
[0036] In further embodiments the filter layers can be applied to the envelope of the tungsten halogen lamps themselves, or alternatively to individual smaller windows or filter disks, designed to be fitted in the lightpath between the lamps and the wafer, for example within the tubular cavity provided for each lamp, above the monolithic quartz glass window which extends over the entire lamp assembly. It is further possible to ensure that both sides of these filter disks are purged with helium as used to cool the lamp assembly, and this may prevent any oxidation of the filter layers when operated at high temperature. Such oxidation can also be prevented by ensuring that the outermost layer of the interference stack is inert to oxidation (e.g. made of silica), and is also of sufficient thickness that oxidation of the under-layers is prevented.
EXAMPLES
Example 1
[0037] Samples are prepared by applying alternating layers Of Si3N4 and SiO2 to an optically transmissive quartz substrate using a magnetron sputter coater. The design of the stack layers thicknesses is based on the equivalent layers method (Epstein, J. Opt. Soc. Am. 42, 806, 1952). The optical transmission of the samples is measured at room temperature using a Lambda 900 Spectrophotometer. The optical transmission of the samples is measured again at room temperature and at 6200C using a Thermofisher Nexus spectrophotometer. The selectivity from 900 nm to 1200 nm (S900-1200) is calculated according to the equation (T<9oo+T>i2oo)/(2*T9oo-i2oo), where T<9Oo is the average transmission over the 500-900 nm range, T>i2oo is the average transmission over the 1200-2500 nm range, and T900-1200 is the average transmission between 900 nm and 1200 nm.
[0038] For example, Sample 1 is an optically transmissive quartz substrate having a 6- layer interference filter applied to each side of the substrate. Layer thicknesses are shown in Table 1. The optical transmission of Sample 1 at room temperature and 6200C are shown in FIG. 3. The S900-1200 value for Sample 1 is 3.4. The RT at WTA for Sample 1 is 65%.
Table 1
Figure imgf000012_0001
Sample 2 is an optically transmissive quartz substrate having a 14-layer interference filter applied to each side of the substrate. Layer thicknesses are shown in Table 2. The optical transmission of Sample 2 at room temperature and 6200C are shown in FIG. 4. The S900-1200 value for Sample 2 is 8.3. The RT at WTA for Sample 2 is 95%.
Table 2
Figure imgf000013_0001
[0039] FIG. 5 is a calculated spectral plot showing the effect of utilizing either Sample 1, or Sample 2 for quartz window 108 on the IR/Visible radiation transmitted from an array of tungsten elements heated at 2500K, and thus incident on a wafer in RTP system 100.
[0040] Note that not all of the activities described above in the general description or the examples are required, that a portion of a specific activity may not be required, and that one or more further activities may be performed in addition to those described. Still further, the order in which activities are listed are not necessarily the order in which they are performed.
[0041] As used herein, the terms "comprises," "comprising," "includes," "including," "has," "having" or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus that comprises a list of features is not necessarily limited only to those features but may include other features not expressly listed or inherent to such process, method, article, or apparatus. Further, unless expressly stated to the contrary, "or" refers to an inclusive-or and not to an exclusive-or. For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present).
[0042] Also, the use of "a" or "an" are employed to describe elements and components described herein. This is done merely for convenience and to give a general sense of the scope of the invention. This description should be read to include one or a and the singular also includes the plural unless it is obvious that it is meant otherwise.
[0043] Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. However, the benefits, advantages, solutions to problems, and any feature(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential feature of any or all the claims.
[0044] After reading the specification, skilled artisans will appreciate that certain features are, for clarity, described herein in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features that are, for brevity, described in the context of a single embodiment, may also be provided separately or in any subcombination. Further, references to values stated in ranges include each and every value within that range.
[0045] While the invention has been illustrated and described in the context of specific embodiments, it is not intended to be limited to the details shown, since various modifications and substitutions can be made without departing in any way from the scope of the present invention. For example, additional or equivalent substitutes can be provided and additional or equivalent production steps can be employed. As such, further modifications and equivalents of the invention herein disclosed may occur to persons skilled in the art using no more than routine experimentation, and all such modifications and equivalents are believed to be within the scope of the invention as defined by the following claims.

Claims

1. A window for use in semiconductor processing comprising; an optically transmissive substrate having an amount of impurity of not greater than about 1.0 wt%; and alternating layers of a first material and a second material on a side of the optically transmissive substrate, the refractive index of the first material being greater than the refractive index of the second material, the alternating layers of the first material and the second material effective to block a narrow band of infrared radiation, the narrow band extending over a range of less than about 800 nm.
2. The window of claim 1, wherein the narrow band extends over a range of less than about 500 nm.
3. The window of claim 1, wherein the ratio of the %transmission of the coated substrate and the uncoated substrate for the narrow band is not greater than about 0.5.
4. The window of claim 1, wherein the alternating layers have a reduction of transmission at a target wavelength of at least about 50%.
5. The window of claim 4, wherein the reduction of transmission at the target wavelength is at least about 55%.
6. The window of claim 5, wherein the reduction of transmission at the target wavelength is at least about 60%.
7. The window of claim 6, wherein the reduction of transmission at the target wavelength is at least about 65%.
8. The window of claim 7, wherein the reduction of transmission at the target wavelength is at least about 70%.
9. The window of claim 1, wherein the window has a selectivity of at least about 3.0, where selectivity is defined as (Thigh+Tiow)/(2*Tcut), where Thigh is the average transmittance for wavelengths above the narrow band and below 2500 nm, Tiow is the average transmittance for wavelengths below the narrow band and above 500 nm, and Tcut is the average transmittance for wavelengths within the narrow band.
10. The window of claim 9, wherein the selectivity is at least about 5.0.
11. The window of claim 10, wherein the selectivity of at least about 8.0.
12. The window of claim 1, wherein the window can withstand temperatures up to at least about 4000C.
13. The window of claim 12, wherein the window can withstand temperatures up to at least about 5000C.
14. The window of claim 13, wherein the window can withstand temperatures up to at least about 6000C.
15. The window of claim 1 , wherein the narrow band of infrared radiation includes wavelengths between about 900 nm and about 1200 nm.
16. The window of claim 15, wherein the window has a selectivity value between 900 and 1200 nm (S900-1200) of at least about 3.0.
17. The window of claim 16, wherein the S900-1200 is at least about 5.0.
18. The window of claim 17, wherein the S900-1200 of at least about 8.0.
19. The window of claim 1, wherein the substrate has a low refractive index.
20. The window of claim 1, wherein the substrate comprises a metal oxide.
21. The window of claim 20, wherein the metal oxide includes SiO2.
22. The window of claim 20, wherein the metal oxide is Al2O3.
23. The window of claim 1, wherein the optically transmissive substrate includes the second material.
24. The window of claim 1, wherein the first material includes oxides of Al, Nb, Ta, Ti, V, Zr, or any combination thereof.
25. The window of claim 1, wherein the first material includes refractory carbides, oxycarbides, nitrides, oxynitrides, metals, or any combination thereof.
26. The window of claim 1, wherein the first and second materials include at least two oxides.
27. The window of claim 26, wherein the oxides include TiO2, ZrO2, Ta2Os, ZnO, SiO2, Al2O3, Nb2O5, BaTiO3, SnO2, In2O3, or any combination thereof.
28. The window of claim 1, wherein the first and second materials have a difference in refractive index of at least about 0.3.
29. The window of claim 28, wherein the first and second materials have a difference in refractive index of at least about 0.5.
30. The window of claim 1, wherein the second material includes SiO2, and the first material has a refractive index at 1000 nm of at least about 1.6.
31. The window of claim 30, wherein the first material has a refractive index at 1000 nm of between about 1.8 and about 2.6.
32. The window of claim 31 , wherein the first material has a refractive index at 1000 nm of between about 1.9 and about 2.4.
33. The window of claim 30, wherein the first material includes Si3N4.
34. The window of claim 1, wherein the alternating layers includes at least three layers of the first material and at least three layers of the second material.
35. The window of claim 34, wherein the alternating layers includes at least seven layers of the first material and at least seven layers of the second material.
36. A quartz window comprising; an optically transmissive quartz substrate; and alternating layers of first material and second material on a side of the optically transmissive quartz substrate, the refractive index of the first material being greater than the refractive index of the second material, the alternating layers of first material and second material effective to block a narrow band of infrared radiation, the narrow band extending over a range of less than about 800 nm.
37. The window of claim 36, wherein the alternating layers have a reduction of transmission at a target wavelength of at least about 50%.
38. The window of claim 36, wherein the ratio of the %transmission of the coated substrate and the uncoated substrate for the narrow band is not greater than about 0.5.
39. The window of claim 36, wherein the window has a selectivity of at least about 3.0, where selectivity is defined as (Thigh+Tiow)/(2*Tcut), where Thigh is the average transmittance for wavelengths above the narrow band and below 2500 nm, Tiow is the average transmittance for wavelengths below the narrow band and above 500 nm, and Tcut is the average transmittance for wavelengths within the narrow band.
40. The window of claim 36, wherein the window can withstand temperatures up to at least about 4000C.
41. The window of claim 36, wherein the narrow band of infrared radiation includes wavelengths between about 900 nm and about 1200 nm.
42. The window of claim 41, wherein the window has a selectivity value between 900 and 1200 nm (S900-1200) of at least about 3.0.
43. The window of claim 36, wherein the second material includes SiO2, and the first material has a refractive index at 1000 nm of at least about 1.6.
44. The window of claim 43, wherein the first material includes Si3N4.
45. The quartz window of claim 36, wherein the alternating layers includes at least three layers of first material and at least three layers of second material.
46. The quartz window of claim 45, wherein the alternating layers includes at least seven layers of first material and at least seven layers of second material.
47. The quartz window of claim 45, wherein the outermost layer of the alternating layers of the first and second materials includes an oxide.
48. A quartz window comprising; an optically transmissive quartz substrate; and alternating layers Of Si3N4 and SiO2 on a side of the optically transmissive quartz substrate, the alternating layers of Si3N4 and SiO2 effective to block a portion of the infrared radiation lying within a wavelength range of between about 900 nm to about 1200 nm.
49. The window of claim 48, wherein the alternating layers have a reduction of transmission at a target wavelength of at least about 50%.
50. The window of claim 48, wherein the ratio of the %transmission of the coated substrate and the uncoated substrate for the narrow band is not greater than about 0.5.
51. The window of claim 48, wherein the window has a selectivity value between 900 and 1200 nm (S900-1200) of at least about 3.0.
52. The quartz window of claim 48, wherein the window can withstand temperatures up to at least about 4000C.
53. The quartz window of claim 48, wherein the alternating layers includes at least three layers of SiO2 and at least three layers of Si3N4.
54. The quartz window of claim 48, wherein the alternating layers includes at least seven layers of SiO2 and at least seven layers Of Si3N4.
55. A quartz window comprising; a optically transmissive quartz substrate; and alternating layers Of Si3N4 and SiO2 on a side of the optically transmissive quartz substrate, the alternating layers of Si3N4 and SiO2 effective to block a portion of the infrared radiation lying within a wavelength range of between about 900 nm to about 1200 nm, wherein the outermost layer includes SiO2 .
56. A rapid thermal processing system comprising; a wafer processing chamber configured to receive a semiconductor wafer; a radiant heat source configured to heat the semiconductor wafer; a window located between the radiant heat source and the wafer processing chamber, the window including a substrate and alternating layers of Si3N4 and SiO2 on a side of the substrate, the alternating layers Of Si3N4 and SiO2 effective to block a narrow band of infrared radiation, the narrow band of infrared radiation extending over a range of less than about 800 nm; a temperature measurement system configured to measure the intensity of radiation emitted from the wafer at a wavelength within the narrow band of infrared radiation.
57. The rapid thermal processing system of claim 56, wherein the narrow band of infrared radiation is between about 900 nm to about 1200 nm.
58. The rapid thermal processing system of claim 56, wherein the radiant heat source is an array of tungsten lamps.
59. The rapid thermal processing system of claim 58, wherein the window is located within a tubular cavity provided for a tungsten lamp of the array of tungsten lamps.
60. A method of forming a semiconductor, comprising: providing a silicon wafer; applying infrared and visible radiation through a window to the silicon wafer to heat the silicon wafer, the quartz window including a substrate and alternating layers of first material and second material on a side of the substrate, the refractive index of the first material being greater than the refractive index of the second material, the alternating layers of first material and second material effective to block a narrow band of infrared radiation, the narrow wavelength band extending over a range of less than about 800 nm; measuring the infrared radiation emitted by the silicon wafer; and determining the temperature of the silicon wafer.
61. The method of claim 60, wherein the ratio of the %transmission of the coated substrate and the uncoated substrate for the narrow band is not greater than about 0.5.
62. The method of claim 60, wherein the alternating layers have a reduction of transmission at a target wavelength of at least about 50%.
63. The method of claim 62, wherein the reduction of transmission at the target wavelength is at least about 55%.
64. The method of claim 63, wherein the reduction of transmission at the target wavelength is at least about 60%.
65. The method of claim 64, wherein the reduction of transmission at the target wavelength is at least about 65%.
66. The method of claim 65, wherein the reduction of transmission at the target wavelength is at least about 70%.
67. The method of claim 60, wherein the quartz window has a selectivity of at least about 3.0, where selectivity is defined as (Thigh+Tiow)/(2*Tcut), where Thigh is the average transmittance for wavelengths above the narrow band and below 2500 nm, Tiow is the average transmittance for wavelengths below the narrow band and above 500 nm, and Tcut is the average transmittance for wavelengths within the narrow band.
68. The method of claim 67, wherein the selectivity is at least about 5.0.
69. The method of claim 68, wherein the selectivity of at least about 8.0.
70. The method of claim 60, wherein the window can withstand temperatures up to at least about 4000C.
71. The method of claim 70, wherein the window can withstand temperatures up to at least about 5000C.
72. The method of claim 71, wherein the window can withstand temperatures up to at least about 6000C.
73. The method of claim 60, wherein the measuring the infrared radiation includes measuring the infrared radiation at a wavelength of about 1000 nm.
74. The method of claim 60, wherein the narrow band of infrared radiation includes wavelengths between about 900 nm and about 1200nm.
75. The window of claim 74, wherein the window has a selectivity value between 900 and 1200 nm (S900-1200) of at least about 3.0.
76. The window of claim 75, wherein the window has an S900-1200 value of at least about 5.0.
77. The window of claim 76, wherein the window has an S900-1200 value of at least about 8.0.
78. The method of claim 60, wherein the substrate includes the second material.
79. The method of claim 60, wherein the first material includes oxides of Al, Nb, Ta, Ti, V, Zr, or any combination thereof.
80. The method of claim 60, wherein the first material includes refractory carbides, oxycarbides, nitrides, oxynitrides, metals, or any combination thereof.
81. The window of claim 60, wherein the first and second materials include at least two oxides.
82. The window of claim 81, wherein the oxides include TiO2, ZrO2, Ta2O5, ZnO, SiO2, Al2O3, Nb2O5, BaTiO3, SnO2, In2O3, or any combination thereof.
83. The window of claim 60, wherein the first and second materials have a difference in refractive index of at least about 0.3.
84. The window of claim 83, wherein the first and second materials have a difference in refractive index of at least about 0.5.
85. The window of claim 60, wherein the second material includes SiO2, and the first material has a refractive index at 1000 nm of at least about 1.6.
86. The window of claim 85, wherein the first material has a refractive index at 1000 nm of between about 1.8 and about 2.6.
87. The window of claim 86, wherein the first material has a refractive index at 1000 nm of between about 1.9 and about 2.4.
88. The window of claim 85, wherein the first material includes Si3N4.
89. The method of claim 60, wherein the alternating layers includes at least three layers of the first material and at least three layers of the second material.
90. The method of claim 89, wherein the alternating layers includes at least seven layers of the first material and at least seven layers of the second material.
91. A method of forming a semiconductor, comprising: providing a silicon wafer; applying infrared and visible radiation through a quartz window to the silicon wafer to heat the silicon wafer, the quartz window including a optically transmissive quartz substrate and alternating layers of Si3N4 and SiO2 on a side of the optically transmissive quartz substrate, the alternating layers of Si3N4 and SiO2 effective to block a portion of the infrared radiation having a wavelength of between about 900 nm to about 1200 nm; and measuring the temperature of the silicon wafer by measuring the infrared radiation emitted by the silicon wafer at a wavelength between about 900 nm to about 1200 nm.
92. The method of claim 91, wherein the ratio of the %transmission of the coated substrate and the uncoated substrate for the narrow band is not greater than about 0.5.
93. The method of claim 91, wherein the alternating layers have a reduction of transmission at a target wavelength of at least about 50%.
94. The window of claim 91, wherein the window has a selectivity value between 900 and 1200 nm (S900-1200) of at least about 3.0.
95. The method of claim 91, wherein the window can withstand temperatures up to at least about 4000C.
96. The method of claim 91, wherein the alternating layers includes at least about three layers Of SiO2 and at least about three layers Of Si3N4.
97. The method of claim 91, wherein the alternating layers includes at least about seven layers of SiO2 and at least about seven layers Of Si3N4.
98. A method of forming a window for use in semiconductor processing, comprising; providing an optically transmissive substrate having an amount of impurity of not greater than about 1.0 wt%; and forming alternating layers of a first material and a second material on a side of the optically transmissive substrate, the refractive index of the first material being greater than the refractive index of the second material, the alternating layers of the first material and the second material effective to block a narrow band of infrared radiation, the narrow band extending over a range of less than about 800 nm.
PCT/EP2009/062702 2008-10-03 2009-09-30 High temperature-resistant narrow band optical filter WO2010037787A1 (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2011066047A1 (en) * 2009-11-30 2011-06-03 General Electric Company Oxide multilayers for high temperature applications and lamps
TWI612259B (en) * 2016-02-26 2018-01-21 財團法人工業技術研究院 Heating apparatus and heating method

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5154512A (en) * 1990-04-10 1992-10-13 Luxtron Corporation Non-contact techniques for measuring temperature or radiation-heated objects
JP2000100391A (en) * 1998-09-21 2000-04-07 Stanley Electric Co Ltd Optical article and electric lamp fitted with infrared reflection film
EP1235061A2 (en) * 2001-02-27 2002-08-28 General Electric Company Optical spectrometer and method for combustion flame temperature determination
US20050063451A1 (en) * 2002-02-28 2005-03-24 Shin-Etsu Handotai Co., Ltd Temperature measuring system, heating device using it and production method for semiconductor wafer, heat ray insulating translucent member, visible light reflection membner, exposure system-use reflection mirror and exposure system, and semiconductor device produced by using them and vetical heat treating device

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5154512A (en) * 1990-04-10 1992-10-13 Luxtron Corporation Non-contact techniques for measuring temperature or radiation-heated objects
JP2000100391A (en) * 1998-09-21 2000-04-07 Stanley Electric Co Ltd Optical article and electric lamp fitted with infrared reflection film
EP1235061A2 (en) * 2001-02-27 2002-08-28 General Electric Company Optical spectrometer and method for combustion flame temperature determination
US20050063451A1 (en) * 2002-02-28 2005-03-24 Shin-Etsu Handotai Co., Ltd Temperature measuring system, heating device using it and production method for semiconductor wafer, heat ray insulating translucent member, visible light reflection membner, exposure system-use reflection mirror and exposure system, and semiconductor device produced by using them and vetical heat treating device

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2011066047A1 (en) * 2009-11-30 2011-06-03 General Electric Company Oxide multilayers for high temperature applications and lamps
US8179030B2 (en) 2009-11-30 2012-05-15 General Electric Company Oxide multilayers for high temperature applications and lamps
TWI612259B (en) * 2016-02-26 2018-01-21 財團法人工業技術研究院 Heating apparatus and heating method

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