EPI self-heating sensor tube as in-situ growth rate sensor

Abstract

A method and apparatus for determining a growth rate on a semiconductor substrate is described herein. The device is an optical sensor, such as an optical growth rate sensor. The optical sensor is located in an exhaust of the deposition chamber. The optical sensor is self-heated using one or more internal heating elements, such as resistive heating elements. The internal heating element is configured to heat the sensor sample. A film is formed on the sensor sample by exhaust gas flowing through the exhaust device, and the film is related to film growth on the substrate within the processing volume of the deposition chamber.

Description

Technical Field

[0001] Embodiments of the present disclosure generally relate to apparatus and methods for manufacturing semiconductor devices. More specifically, the apparatus disclosed herein relates to an exhaust assembly and a growth rate sensor within an epitaxial deposition process chamber. Methods of using the same are also disclosed. Background Art

[0002] Semiconductor substrates are processed for a variety of applications, including the manufacture of integrated devices and micro-devices. One substrate processing method includes depositing a material, such as a dielectric material or a conductive metal, on an upper surface of a substrate in a processing chamber. For example, epitaxy is a deposition process that grows an ultrapure thin layer, typically silicon or germanium, on a substrate surface. The material may be deposited in a lateral flow chamber by flowing a process gas parallel to the surface of the substrate on a support and thermally decomposing the process gas to deposit material from the process gas onto the substrate surface.

[0003] Film thickness measurements of processed substrates may be used in connection with processing operations. Film thickness measurements may be performed outside of a processing chamber where the processed substrates are processed, after the processing operations are performed (e.g., off-line). Off-line measurements may involve inefficiencies and reduced throughput because substrates that do not meet specifications cannot be used, and several processing iterations may be required to obtain measurements that meet specifications.

[0004] Furthermore, it is difficult to perform film thickness measurements within a processing chamber and during processing operations because processing equipment within the processing chamber may interfere with the measurement equipment, thereby hampering measurement accuracy. For example, infrared lamp radiation and heat from the lamp may interfere with the measurement equipment.

[0005] Therefore, there is a need for improved apparatus and methods for in-situ measurement of film thickness in a processing chamber. Summary of the invention

[0006] Embodiments of the present disclosure generally relate to in-situ monitoring of film growth in a processing chamber. More particularly, embodiments disclosed herein relate to sensor assemblies for epitaxial chambers, methods of using the same, and related devices.

[0007] The present disclosure relates generally to process chambers for semiconductor processing. In one embodiment, a growth rate sensor suitable for use during semiconductor substrate manufacturing is described. The growth rate sensor includes a body, an optically transparent window disposed at one end of the body, a silicon-containing sample disposed within the body and adjacent to the optically transparent window, a resistive heating element disposed within the body and adjacent to the optically transparent window, a radiation sensor, and an optical fiber disposed between the radiation sensor and the optically transparent window.

[0008] In another embodiment, an exhaust assembly suitable for use during semiconductor substrate manufacturing is described. The exhaust assembly includes one or more exhaust channel bodies, an exhaust collector disposed at a distal end of the one or more exhaust channel bodies, and a growth rate sensor disposed within the exhaust collector. The growth rate sensor includes an optically transparent window, a silicon-containing coupon disposed on a first side of the optically transparent window, and a resistive heating element disposed on a second side of the optically transparent window.

[0009] In another embodiment, a processing chamber suitable for use during semiconductor substrate processing is described. The processing chamber includes a chamber body, a substrate support disposed within a processing volume of the chamber body, an upper window disposed above the substrate support and the processing volume, a lower window disposed below the substrate support and the processing volume, a gas injector disposed within the chamber body, an exhaust system disposed within the chamber body opposite the gas injector, and a growth rate sensor disposed within the exhaust system. The growth rate sensor includes an optically transparent window, a silicon-containing coupon disposed on a first side of the optically transparent window, and a resistive heating element disposed on a second side of the optically transparent window.

[0010] In another embodiment, a non-transitory computer readable medium is described. The non-transitory computer readable medium stores instructions that, when executed by a processor, cause a computer system to perform a number of processing operations. The processing operations include monitoring the intensity of radiation reflected by or transmitted through a growth rate sensor. The growth rate sensor further includes an optically transparent window, a silicon-containing coupon disposed on a first side of the optically transparent window, and a resistive heating element disposed on a second side of the optically transparent window. The processing operations further include heating the sensor coupon using an internal heating element during monitoring the intensity of the radiation, and determining a growth rate of a film deposited on the sensor coupon based on changes in the intensity of the radiation.

[0011] BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to facilitate a detailed understanding of the above features of the present disclosure, the present disclosure briefly summarized above may be described in more detail with reference to the embodiments, some of which are illustrated in the accompanying drawings. However, it should be noted that the drawings only illustrate exemplary embodiments and are therefore not to be considered as limiting the scope thereof, and other equivalent embodiments may be allowed.

[0013] Figure 1 is a schematic diagram of a deposition chamber according to an embodiment of the present disclosure.

[0014] Figure 2 The embodiment according to the present disclosure is shown Figure 1 A plan cross-sectional view of a deposition chamber.

[0015] Figure 3The embodiment according to the present disclosure is shown Figure 1 A side cross-sectional view of an exhaust system of a deposition chamber.

[0016] 4A to 4D The diagram shows a method for Figure 1 Growth rate monitor inside the deposition chamber.

[0017] Figure 5 FIG. 2 is a schematic diagram showing a method of processing a substrate according to an embodiment of the present disclosure.

[0018] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements in the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation. DETAILED DESCRIPTION

[0019] The present disclosure relates to exhaust assemblies and growth rate sensors within semiconductor processing chambers. The growth rate sensors monitor film growth in a processing chamber in situ. As an example, embodiments disclosed herein provide apparatus and methods for in situ monitoring of film growth and measuring film thickness in a processing chamber, such as an epitaxial deposition chamber.

[0020] Embodiments disclosed herein provide a growth rate sensor located in an exhaust of a processing chamber in such a manner as to receive epitaxial film growth thereon. The film growth on the growth rate sensor simulates epitaxial film growth occurring simultaneously on a substrate located in the processing chamber. The growth rate sensor is heated to a temperature similar to that of the substrate in the processing volume of the processing chamber.

[0021] Embodiments disclosed herein may allow a substrate and / or sample to have a temperature similar to that of a substrate being processed in a processing chamber to simulate film deposition characteristics of the substrate.

[0022] Embodiments disclosed herein provide sensor windows and substrates / specimens having compositions capable of backside spectral wavelength measurements in reflection mode, transmission mode, or both reflection mode and transmission mode.

[0023] Embodiments disclosed herein provide a sensor assembly capable of performing spectral reflectance measurements with low signal-to-noise characteristics within an epitaxial deposition chamber. Noise includes noise generated by radiation from infrared lamps in the epitaxial chamber. Embodiments of the sensor assembly described herein provide a sensor body having a radiation path therein. The sensor body is sealed from stray infrared radiation. Embodiments of the sensor assembly described herein provide a growth rate sensor comprising a resistive heating element for providing a controlled temperature of the growth rate sensor. The resistive heating element increases the temperature of the sensor window and advantageously increases the temperature of the sensor window and a substrate / specimen disposed on the sensor window toward the temperature of the substrate being processed. Embodiments of the sensor assembly described herein provide an optical path isolated from a process gas flow.

[0024] Self-heating the growth rate sensor using a resistive heating element or another heating element enables the growth rate sensor to be flexibly mounted in various locations within the processing chamber. The flexible mounting location of the growth rate sensor enables the increased sensitivity to be maintained because the self-heating of the growth rate sensor prevents the detection sensitivity from decreasing as the sensor position changes. The use of a self-heating sensor as an in-situ growth rate sensor also reduces the need for signal modulation. Heating of the growth rate sensor window and substrate / specimen also facilitates regeneration of the substrate / specimen during cleaning operations within the processing chamber.

[0025] In some embodiments, the growth rate sensor is located within the exhaust so that airflow is still provided past the growth rate sensor and radiation from lamps or other radiation sources within the processing volume is reduced. The reduced background radiation enables the growth rate sensor to utilize a greater wavelength range when determining growth rate.

[0026] A quartz body is disposed around at least a portion of the growth rate sensor and isolates the growth rate sensor from the deposition environment.

[0027] Figure 1 1 is a schematic diagram of a deposition chamber 100 according to an embodiment of the present disclosure. The deposition chamber 100 is an epitaxial deposition chamber. The deposition chamber 100 is used to grow an epitaxial film on a substrate such as a substrate 102. The deposition chamber 100 generates a lateral flow of a precursor on a top surface 150 of the substrate 102.

[0028] The deposition chamber 100 includes an upper body 156, a lower body 148 disposed below the upper body 156, and a flow module 112 disposed between the upper body 156 and the lower body 148. The upper body 156, the flow module 112, and the lower body 148 form a chamber body. Disposed within the chamber body are a substrate support 106, an upper window 108, a lower window 110, a plurality of upper lamps 141, and a plurality of lower lamps 143. As shown, a controller 120 communicates with the deposition chamber 100 and is used to control processes such as those described herein. The substrate support 106 is disposed between the upper window 108 and the lower window 110. The plurality of upper lamps 141 are disposed between the upper window 108 and the cover 154. The plurality of upper lamps 141 form a portion of an upper lamp module 155. The cover 154 may include a plurality of sensors (not shown) disposed therein for measuring the temperature within the deposition chamber 100. A plurality of lower lamps 143 are disposed between the lower window 110 and the bottom plate 152. The plurality of lower lamps 143 form a portion of a lower lamp module 145. The upper window 108 is an upper dome and is formed of an energy-transmitting material such as quartz. The lower window 110 is a lower dome and is formed of an energy-transmitting material such as quartz.

[0029] A processing volume 136 is formed between the upper window 108 and the lower window 110. The processing volume 136 has a substrate support 106 disposed therein. The substrate support 106 includes a top surface on which the substrate 102 is disposed. The substrate support 106 is attached to a shaft 118. The shaft is connected to a motion assembly 121. The motion assembly 121 includes one or more actuators and / or adjustment devices that provide movement and / or adjustment of the shaft 118 and / or the substrate support 106 within the processing volume 136.

[0030] The substrate support 106 may include lift pin holes 107 disposed therein. The lift pin holes 107 are sized to receive lift pins 132 for lifting the substrate 102 from the substrate support 106 before or after performing a deposition process. The lift pins 132 may rest on lift pin stops 134 when the substrate support 106 is lowered from the processing position to the transfer position.

[0031] The flow module 112 includes a plurality of process gas inlets 114, a plurality of purge gas inlets 164, and one or more exhaust outlets 116. The plurality of process gas inlets 114 and the plurality of purge gas inlets 164 are disposed on a side of the flow module 112 opposite to the one or more exhaust outlets 116. One or more flow guides are disposed below the plurality of process gas inlets 114 and the one or more exhaust outlets 116. The flow guide is disposed above the purge gas inlet 164. The liner 163 is disposed on an inner surface of the flow module 112 and protects the flow module 112 from the reactive gas used during the deposition process. The process gas inlet 114 and the purge gas inlet 164 are positioned so that the gas flows parallel to the top surface 150 of the substrate 102 disposed in the processing volume 136. The process gas inlet 114 is fluidly connected to the process gas source 151. The purge gas inlet 164 is fluidly connected to the purge gas source 162. The one or more exhaust outlets 116 are fluidly connected to the exhaust pump 157.

[0032] The one or more exhaust outlets 116 are further connected to or include an exhaust system 178. The exhaust system 178 fluidly connects the one or more exhaust outlets 116 and the exhaust pump 157. The exhaust system 178 described herein includes one or more growth monitors 160a, 160b. Each of the one or more growth monitors 160a, 160b is coupled to an optical module 167a, 167b. Thus, the first growth monitor 160a is coupled to the first optical module 167a, and the second growth monitor 160b is coupled to the second optical module 167b. The first fiber optic cable 165a optically couples the first growth monitor 160a and the first optical module 167a. The second fiber optic cable 165b optically couples the second growth monitor 160b and the second optical module 167b.

[0033] Figure 2 The embodiment according to the present disclosure is shown Figure 1 1. The deposition chamber 100 is a plan cross-sectional view of the deposition chamber 100. The deposition chamber 100 includes an injector 202 disposed opposite the exhaust system 178. The injector 202 includes a process gas inlet 114 and is fluidly coupled to the process gas source 151. The injector 202 can be disposed through at least a portion of the flow module 112, or can be a part of the flow module 112. The exhaust system 178 is disposed on a side of the processing volume 136 opposite the injector 202. The exhaust system 178 is formed through the flow module, attached to the flow module, or is a part of the flow module.

[0034] The exhaust system 178 also includes at least one exhaust channel body 204a, 204b. The exhaust channel bodies 204a, 204b form an exhaust path for the gas leaving the processing volume 136 before entering the exhaust collector 206. Figure 2As shown, there is a first exhaust channel body 204a and a second exhaust channel body 204b. The first exhaust channel body 204a and the second exhaust channel body 204b are mirror images and can be similar in size and configuration. In other embodiments, there may be more or fewer exhaust channel bodies 204a, 204b. In some embodiments, there is only one exhaust channel body, so that the two exhaust channel bodies 204a, 204b are merged into a single body. In other embodiments, there may be three or more exhaust channel bodies, such as three exhaust channel bodies 204a, 204b. The size and configuration of the exhaust channel bodies 204a, 204b may vary depending on the size and operation of the deposition chamber 100.

[0035] The first exhaust channel body 204a and the second exhaust channel body 204b are both coupled to an exhaust collector 206, which is located on an end of the exhaust channel bodies 204a, 204b opposite to the processing volume 136. The exhaust collector 206 is configured to collect exhaust from the first exhaust channel body 204a and the second exhaust channel body 204b. As the exhaust collector 206 extends away from the exhaust channel bodies 204a, 204b, the exhaust collector 206 narrows. Growth monitors 160a, 160b are disposed within the exhaust collector 206. The growth monitors 160a, 160b are disposed near the entrance from the exhaust channel bodies 204a, 204b to the exhaust collector 206. The growth monitors 160a, 160b can be placed at various locations within the exhaust collector 206 and / or the exhaust channel bodies 204a, 204b. There may be additional growth monitors 208a, 208b, 208c also disposed within the exhaust collector 206 and / or the exhaust passage bodies 204a, 204b. The additional growth monitors 208a, 208b, 208c may be similar to the growth monitors 160a, 160b, or may be different types of growth monitors, such as quartz crystal growth monitors.

[0036] Figure 3 Shows Figure 1 1 is a side cross-sectional view of the exhaust system 178 of the deposition chamber 100. Inside each exhaust channel body 204a, 204b is an exhaust chamber. An exhaust chamber 312a of a first exhaust channel body 204a is shown, and a similar second exhaust chamber is provided through the second exhaust channel body 204b. Figure 3 As shown, the exhaust plenum 312 a of the exhaust system 178 extends through at least a portion of the flow module 112 such that the exhaust plenum 312 a extends through a sidewall of the flow module 112 and interacts with the processing volume 136 .

[0037] The gas is exhausted from the processing volume 136 into the exhaust chamber 312a. The gas further flows from the exhaust chamber 312a into the collector chamber 316. The collector chamber 316 is a chamber disposed within the exhaust collector 206.

[0038] One or more growth monitors 160a, 160b are located within the exhaust chamber 312a or within the collector chamber 316. The first growth monitor 160a is disposed within the inner upper surface 324 of the exhaust collector 206 and the collector chamber 316. The second growth monitor 160b is disposed within the inner lower surface 327 of the exhaust collector 206 and the collector chamber 316. Alternatively or in addition to placing the growth monitors 160a, 160b within the exhaust collector, one or more similar growth monitors are positioned within the inner upper surface 326 or the inner lower surface 329 of the exhaust duct body 204a, 204b and communicate with the exhaust chamber 312a. Growth monitors 160a, 160b are disposed in either the inner upper surface 324 or the inner lower surface 327 of collector plenum 316 such that growth monitors 160a, 160b do not block the flow path of the exhaust gas, but still allow deposition on sensor coupons 362a, 362b. First growth monitor 160a includes sensor coupon 362a oriented downward and facing inner lower surface 328. Second growth monitor 160b includes second sensor coupon 362b oriented upward and facing inner upper surface 324.

[0039] The exhaust gas passes through the growth monitors 160a, 160b and enters the collector air chamber 316, and then is discharged from the exhaust collector 206 through the duct opening 306 of the exhaust duct 323. The duct opening 306 is disposed at a portion of the collector air chamber 316, which is opposite to the end of the collector air chamber 316 adjacent to the exhaust chamber 312a and the exhaust channel bodies 204a, 204b. The duct opening 306 is configured to allow the exhaust gas within the exhaust collector 206 to be discharged to the exhaust pump 157 through the exhaust duct 323. The rear side wall 321 of the exhaust chamber 312a is disposed adjacent to the duct opening 306 and can be configured to direct the gas into the duct opening 306. The duct opening 306 is disposed through the inner lower surface 327 of the collector air chamber 316 and leads to the exhaust duct 323. The exhaust duct 323 extends downward from the duct opening 306 and is fluidly connected to the exhaust pump 157.

[0040] 4A to 4D Shown for Figure 1 Different embodiments of growth monitors 160a, 160b, 160c, 160d in a deposition chamber. Each of the growth monitors 160a, 160b, 160c, 160d is configured to measure the amount of growth that occurs when a sample (e.g. Figure 4A and Figure 4C Sensor sample 362a or Figure 4B and Figure 4D The change in the transmission and / or reflection of radiation through the sample is caused by the growth of the film 476 on the sensor samples 362a, 362b. As the film 476 grows, the wavelength and intensity of the radiation passing through the sensor samples 362a, 362b or reflected from the sensor samples 362a, 362b change and are measured to determine the growth rate of the film 476. The growth rate of the film 476 can be related to the growth rate on the substrate (such as the substrate 102 in the deposition chamber 100). One or more heating elements are used to heat the growth monitors 160a, 160b, 160c, 160d. The one or more internal heating elements can be a resistive heating element, a Peltier device, an infrared (IR) heating element, or a heating fluid conduit. Other heating devices are also considered and can be used as one or more internal heating elements. The one or more heating elements are configured to be adjacent to the sensor samples 362, 362b.

[0041] Figure 4A A first embodiment of a growth monitor 160a is shown. Figure 4A The growth monitor 160a includes an outer body 402 and an optically transparent inner body 463. The growth monitor 160a is positioned so that the growth monitor 160a is disposed through the inner upper surface 324. The growth monitor 160a is also configured so that it includes a radiation source 434 disposed in the first optical module 167a. The radiation source 434 is placed in the first optical module 167a together with the radiation sensor 436 so that Figure 4A Growth monitor 160a can be a reflectance monitor and measure radiation reflected by sensor sample 362a from a radiation beam emitted from radiation source 434. First optical module 167a can also utilize background radiation that passes through sensor sample 362a from collector plenum 316 instead of radiation source 434.

[0042] The radiation sensor 436 may include a spectrometer. Other radiation sensors 436 are also contemplated and may be used. The radiation measured by the radiation sensor 436 is about 0.5 μm to about 6 μm, such as about 1 μm to about 5 μm, such as about 2 μm to about 4 μm. The radiation emitted by the radiation source 434 is about 0.5 μm to about 6 μm, such as about 1 μm to about 5 μm, such as about 2 μm to about 4 μm.

[0043] The outer body 402 and the optically transparent inner body 463 together form the body of the growth monitor 160a. The outer body 402 is disposed through the wall of the exhaust system 178 so that the outer body 402 is disposed through the inner upper surface 324 and the bottom of the growth monitor 160a is exposed to the collector plenum 316 and the exhaust passing through the exhaust system 178. The transparent inner body 463 is transparent to radiation within a predetermined range. In some embodiments, the transparent inner body 463 has a radiation transmittance of 90% or more between wavelengths of 0.2 μm to about 5.0 μm (such as about 0.5 μm to about 5.0 μm, such as about 1.0 μm to about 4.5 μm). The wavelength at which the transparent inner body 463 is transparent may be at least partially affected by the type of heating source. The transparent inner body 463 may be transparent to radiation emitted by the radiation source 434 and radiation received by the radiation sensor 436. A portion of the transparent inner body 463 is formed by an optically transparent window 462a. The optically transparent window 462a is disposed adjacent to the collector plenum 316. The optically transparent window 462a can be the same or a different material than the rest of the transparent inner body 463.

[0044] The sensor coupon 362a is disposed adjacent to the optically transparent window 462a and the transparent inner body 463. The sensor coupon 362a includes a deposition surface 428a and a backside surface 430a. The deposition surface 428a is oriented toward the inner lower surface 327. A film 476 grows on the deposition surface 428a during processing operations and is associated with film growth on a substrate within a processing volume of a semiconductor processing chamber, such as the deposition chamber 100.

[0045] In the growth monitor 160a, the cover 404 is used to fix the sensor sample 362a on the transparent inner body 463. The cover 404 is configured to partially surround the sensor sample 362a so that the cover 404 can fix the sensor sample 362a. Figure 4A As shown, the outer edge of the deposition surface 428a of the sensor coupon 362a is covered and held by the cover 404 to fix the sensor coupon 362a. The central portion of the deposition surface 428a of the sensor coupon 362a is uncovered and exposed to the collector plenum 316.

[0046] A backside sensor chamber 408 is formed above the sensor coupon 362a and between the backside surface 430a and the optically transparent window 462a. The backside sensor chamber 408 reduces the pressure on the sensor coupon 362a that would otherwise be applied by the cover 404 if the cover 404 held the backside surface 430a flush with the optically transparent window 462a. Utilizing the backside sensor chamber 408 creates a pressure differential between the backside sensor chamber 408 and the collector chamber 316 during processing. Therefore, to prevent damage to the sensor coupon 362a due to the pressure differential, one or more equalization ports (not shown) may be provided between the outer surface of the transparent inner body 463 and the backside sensor chamber 408 to allow pressure equalization between the backside sensor chamber 408 and the surrounding volume (e.g., the collector chamber 316).

[0047] The cover 404 may include a sample transfer port 406. The sample transfer port 406 may be located at an upstream or downstream position. The sample transfer port 406 is configured to be able to transfer the sensor sample 362a into and out of the cover 404. Therefore, the bottom surface of the cover 404 acts as a bracket, and the sample transfer port 406 may have a surface coplanar with the support surface of the cover 404, which supports the sensor sample 362a. The width of the sample transfer port 406 is at least the same as the width of the sensor sample 362a. Therefore, the sample transfer port 406 is a rectangular or arcuate opening through the transparent inner body 463. The sample transfer port 406 can be patched or filled before the transparent inner body 463 is positioned inside the collector air chamber 316. The patch or filler can be a plug. The patch material or filler material is the same as the material of the transparent inner body 463, and can be applied or positioned using a high temperature coating operation.

[0048] In one or more examples, the thickness of the sensor sample 362a is about 400 μm or less, such as about 200 μm to about 400 μm, such as about 250 μm to about 350 μm, such as about 300 μm. The thickness of the sensor sample 362a is configured to reduce the attenuation of radiation passing therethrough. In one or more examples, the sensor sample 362a has a crystalline structure. Advantageously, the crystalline structure sensor sample 362a increases the radiation transmittance and thermal conductivity relative to the corresponding amorphous material. Therefore, heat and radiation can be easily transferred between the optically transparent window 462a and the sensor sample 362a. Therefore, the heating of the sensor sample 362a is more predictable and uniform, and the radiation from the radiation source is easily measured through the sensor sample 362a. In one embodiment that can be combined with other embodiments, the sensor sample 362a is a silicon-containing sample. In one embodiment, the sensor sample 362a is formed of silicon carbide (e.g., SiC). Other materials can also be considered for the sensor sample 362a. Advantageously, the silicon carbide sensor sample 362a provides a spectral transmission signal for any silicon-based doped or undoped film deposited thereon, unlike a sensor sample 362a formed of only silicon, which does not provide a spectral transmission signal for a silicon-based film. In one embodiment that may be combined with other embodiments, the sensor sample 362a is crystalline silicon carbide. The crystal structure of the sensor sample 362a is 6H, 4H, 3C, or a combination thereof.

[0049] The roughness of the deposition surface 428a of the sensor coupon 362a is less than 3 nanometers, such as less than 2 nanometers, such as less than 1 nanometer. In one embodiment that can be combined with other embodiments, the transparent inner body 463 and the optically transparent window 462a are formed of silicon carbide (e.g., SiC), quartz (e.g., black quartz, black opaque quartz, or white opaque quartz), or a combination thereof. Other materials are also contemplated and can be used in the transparent inner body 463. The material and geometry of the transparent inner body 463 are configured to reduce stray radiation passing through the transparent window 462a and located within the transparent inner body 463. Stray radiation at wavelengths of about 300 nanometers to about 1000 nanometers, such as about 400 nanometers to about 800 nanometers, is reduced.

[0050] The outer body 402 is a metal material and can be configured to absorb any radiation escaping from the transparent inner body 463. The outer body 402 is a metal material, such as stainless steel. Other materials are also contemplated and can be used within the outer body 402. In some embodiments, the inner surface of the outer body 402 is gold-plated. Other materials are also contemplated and can be used as a coating or film within the outer body 402. The outer body 402 and the transparent inner body 463 both have cylindrical outer walls and cylindrical inner walls. In some embodiments, the inner and outer walls of the outer body 402 and the transparent inner body 463 are prisms, such as rectangular prisms, pentagonal prisms, or hexagonal prisms. Other prisms can also be used.

[0051] An internal heating element 411 is disposed within the outer body 402 and the transparent inner body 463. The internal heating element 411 may be a resistive heating element, a Peltier device, or a heating fluid conduit. Other heating devices are also contemplated and may be used as the internal heating element 411. In the embodiments described herein, the internal heating element 411 is a resistive heating element. The internal heating element 411 provides fast and precise control of the temperature of the sensor sample 362a. In some embodiments, the internal heating element 411 is capable of heating the sensor sample 362a and controlling the heating of the sensor sample 362a to between about 300°C and about 1200°C, such as about 400°C to about 1000°C, such as about 500°C to about 900°C. The temperature of the sensor sample 362a is controlled with an accuracy of less than about 10°C, such as less than about 7°C, such as less than about 5°C.

[0052] The internal heating element 411 includes a low resistance element 412 and a high resistance element 410. The high resistance element 410 has a higher resistivity than the low resistance element 412, such that the resistivity of the high resistance element 410 is greater than 10 times the resistivity of the low resistance element 412, such as greater than 20 times the resistivity of the low resistance element 412, such as greater than 50 times the resistivity of the low resistance element 412. The high resistance element 410 is disposed adjacent to the optically transparent window 462a and the sensor sample 362a. The high resistance element 410 has a resistivity of about 10 3 Ω·cm to about 10 6 Ω·cm, such as about 2000 Ω·cm to about 10,000 Ω·cm, such as about 10 4 Ω·cm to about 10 5 Ω·cm, such as about 10 5 Ω·cm to about 10 6Ω·cm. The low resistance element 412 has a resistivity of about 0.1 Ω·cm to about 100 Ω·cm, such as about 1 Ω·cm to about 10 Ω·cm, such as about 10 Ω·cm to about 100 Ω·cm. The low resistance element 412 is configured to transfer power from one or more power sources 426 to the high resistance element 410. The high resistance element 410 is configured to be heated when power is applied thereto.

[0053] The temperature measuring device 414 is disposed near and / or in contact with the high resistance element 410. The temperature measuring device 414 is configured to measure the temperature of one or both of the optically transparent window 462a and the sensor sample 362a. The temperature measuring device 414 of the growth monitor 160 is a thermocouple or a pyrometer. Other temperature measuring devices are also considered and can be used as the temperature measuring device 414. The temperature measuring device 414 is coupled to a temperature measurement receiver 418 via wiring 416. The temperature measurement receiver 418 is configured to apply power to the thermocouple and measure the voltage of the thermocouple and the corresponding voltage change. In some embodiments, the temperature measurement receiver 418 is integrated into the controller 120. In some embodiments, the band gap absorption of the sensor sample 362a and / or the optically transparent window 462 is measured to determine the temperature of the optically transparent window 462 and the sensor sample 362a. This can be a supplement or replacement for the temperature measuring device 414.

[0054] The growth monitor 160a further includes one or more lenses 424 and one or more reflectors 422. The lenses 424 and reflectors 422 are configured to collimate and direct radiation between the sensor coupon 362a and the radiation sensor 436. The partition 432 is located between the lower end of the growth monitor 160a and the upper end of the growth monitor 160a. The lower end includes the high resistance element 410, the low resistance element 412, the sensor coupon 362a, the optically transparent window 462a, the optically transparent inner body 463, and the temperature measurement device 414. The upper end includes one or more lenses 424 and one or more reflectors 422. The partition can reduce stray radiation that interacts with the one or more lenses 424 and the one or more reflectors 422.

[0055] One or more fiber optic cables 420, 165a are disposed along the radiation measurement path 425. The first fiber optic cable 165a is disposed between the first optical module 167a and the body of the growth monitor 160a. The second fiber optic cable 420 is disposed between the optically transparent window 462 / sensor sample 362a and the reflector 422 / lens 424. In some embodiments, the second fiber optic cable 420 is omitted.

[0056] Figure 4B A second embodiment of a growth monitor 160b is shown. Figure 4B The growth monitor 160b is similar to Figure 4A, but the growth monitor 160b is set through the inner lower surface 327 of the exhaust collector 206.

[0057] The growth monitor 160a is also configured such that it includes a radiation source 434 and a radiation sensor 436 disposed in the second optical module 167b. The radiation source 434 and the radiation sensor 436 are placed together in the second optical module 167b so that Figure 4B Growth monitor 160b becomes a reflectance monitor and measures radiation reflected by sensor sample 362b from a radiation beam emitted from radiation source 434. Second optical module 167b may also utilize background radiation that passes through sensor sample 362b from collector plenum 316 instead of radiation source 434.

[0058] In the growth monitor 160b, the sensor coupon 362b is positioned with the deposition surface 428 oriented upward so that the deposition surface 428 faces the inner upper surface 324. The sensor coupon 362b is positioned on top of the optically transparent window 462b so that the back surface 430b of the sensor coupon 362b is positioned on the optically transparent window 462b. Since gravity holds the sensor coupon 362b on the optically transparent window 462b, positioning the sensor coupon 362b on top of the optically transparent window 462b enables removal of the sensor coupon 362b. Figure 4A The cover 404 of the growth monitor 160a of FIG. 4 is provided with the sensor sample 362b in the pocket 435. The pocket 435 is a concave opening and is configured to receive the sensor sample 362b. The optically transparent window 462b is the bottom surface of the pocket 435. Since the sensor sample 362b is arranged flush with the optically transparent window 462b, there is no backside sensor plenum 408 or equalization ports 406a, 406b. This exposes the entire deposition surface 428 to the exhaust gas.

[0059] Figure 4C A third embodiment of a growth monitor 160c is shown. Figure 4C The Growth Monitor 160c is similar to Figure 4A 362a. The growth monitor 160c is similar to the growth monitor 160a of FIG. 20, but the radiation source 434 is separate from the radiation sensor 436 and is arranged to transmit radiation through the sensor sample 362a. Thus, the growth monitor 160c measures radiation transmitted through the sensor sample 362a, rather than radiation reflected from the sensor sample 362a. The radiation outlet 440 is arranged through the inner lower surface 327 of the exhaust collector 206.

[0060] Figure 4D A fourth embodiment of a growth monitor 160d is shown. Figure 4D The Growth Monitor 160d is similar to Figure 4B362b. The growth monitor 160d is similar to the growth monitor 160d of FIG. 360b, but the radiation source 434 is separate from the radiation sensor 436 and is arranged to transmit radiation through the sensor sample 362b. Thus, the growth monitor 160d measures radiation transmitted through the sensor sample 362b, rather than radiation reflected from the sensor sample 362b. The radiation outlet 440 is arranged through the inner upper surface 324 of the exhaust collector 206.

[0061] Figure 5 is a schematic diagram illustrating a method 500 for processing a substrate. In one or more examples, the method 500 can be implemented using one of the example processing chambers and / or sensor assemblies disclosed herein. In one or more examples, the method 500 can be in the form of instructions stored on a computer readable medium (e.g., a memory), which, when executed by a processor (e.g., a CPU) of the system, causes the system to implement the method 500. The computer readable medium and corresponding system are part of a controller (e.g., controller 120).

[0062] In operation 502, a film is simultaneously deposited on a substrate (such as substrate 102) and a sensor coupon (such as sensor coupon 362a or 263b) of a growth rate sensor, which is disposed in a processing chamber (such as deposition chamber 100). Depositing the film includes flowing one or more precursors or process gases from a process gas source and heating the substrate. The process gas flows as a side injection over the surface of the substrate as the substrate rotates on a substrate support or pedestal. In operation 504, the sensor coupon and an optically transparent window to which the sensor coupon is coupled are heated using an internal heating element in the growth rate sensor, such as internal heating element 411. In one embodiment that may be combined with other embodiments, heating the sensor coupon and the optically transparent window at least partially by the internal heating element includes supplying power to a resistive heating element disposed in the growth rate sensor. The internal heating element is heated to a predetermined temperature that is similar to the temperature of the substrate being processed in the processing volume. During operation 504, the difference between the substrate temperature and the coupon temperature is less than about 50°C, such as less than about 30°C, such as less than about 20°C. The temperature of the specimen and / or internal heating elements is measured separately using a temperature measuring device such as a thermocouple.

[0063] In operation 506, the intensity of radiation reflected from or transmitted through the sensor window is measured using a spectrometer as part of the radiation sensor. During operation 506, radiation may also be emitted by a radiation source. The radiation source may be a laser or an optical fiber. The radiation measured by the spectrometer and emitted by the radiation source is about 0.5 μm to about 6 μm, such as about 1 μm to about 5 μm, such as about 2 μm to about 4 μm.

[0064] In operation 508, at least one of a thickness or a growth rate of a film deposited on the crystal sensor window is determined based on the measured radiation intensity. In one embodiment that may be combined with other embodiments, the determination of the thickness and / or the growth rate includes measuring a plurality of radiation intensity values ​​of radiation (which may include transmitted radiation and / or reflected radiation) across one or more time intervals. Based on the Fresnel equations for electromagnetic wave reflection, the plurality of radiation intensity values ​​are correlated with reference data or a physical model to determine the growth rate within one or more time intervals. The growth rate and / or thickness (such as a change in thickness) may correspond to a change in radiation intensity within one or more time intervals. In one or more examples, the growth rate at a certain time interval may be used to determine the film thickness.

[0065] Each of the growth monitors 160a, 160b, 160c, 160d described herein can be used with the deposition chamber 100 described herein or other forms of semiconductor processing chambers. In some embodiments, the growth monitors 160a, 160b, 160c, 160d are placed in a semiconductor processing chamber other than the semiconductor processing chambers described herein, such as an atomic layer deposition (ALD) chamber, a physical vapor deposition (PVD) chamber, and other versions of a chemical vapor deposition (CVD) chamber. The placement of the growth monitors 160a, 160b, 160c, 160d reduces the amount of stray radiation from lamps or other heating elements compared to when the growth monitors 160a, 160b, 160c, 160d are located within the processing volume 136 of the deposition chamber 100. However, by positioning the growth monitor 160a, 160b, 160c, 160d inside the exhaust, the growth monitor 160a, 160b, 160c, 160d is not heated by the same heating element or lamp as the substrate 102. The quality of film growth and removal operations from sensor coupons such as sensor coupons 362a, 362b may be reduced if the temperature of the growth monitor 160a, 160b, 160c, 160d is not similar to the temperature of the substrate 102. Therefore, the growth monitors 160a, 160b, 160c, 160d described herein have internal heating elements 411 disposed therein.

[0066] The internal heating element 411 can maintain the growth monitor 160a, 160b, 160c, 160d at a temperature similar to the temperature of the substrate 102, while still having reduced background radiation. The use of self-heating growth monitors 160a, 160b, 160c, 160d further enables flexible placement of the growth monitors 160a, 160b, 160c, 160d throughout the deposition chamber 100. Thus, the growth monitors 160a, 160b, 160c, 160d can be placed in different parts of the exhaust system 178. The placement of the growth monitors 160a, 160b, 160c, 160d within the exhaust system 178 further reduces system complexity within the processing volume 136 compared to the placement of the growth monitors 160a, 160b, 160c, 160d within the processing volume 136.

[0067] In an embodiment of the present disclosure, a processing chamber suitable for use during semiconductor substrate processing is described. The processing chamber includes a chamber body, a substrate support disposed within a processing volume of the chamber body, an upper window disposed above the substrate support and the processing volume, a lower window disposed below the substrate support and the processing volume, a gas injector disposed within the chamber body, an exhaust system disposed within the chamber body opposite the gas injector, and a growth rate sensor disposed within the exhaust system. The growth rate sensor includes an optically transparent window, a silicon-containing coupon disposed on a first side of the optically transparent window, and a resistive heating element disposed on a second side of the optically transparent window.

[0068] In some embodiments, the growth rate sensor further comprises a body, a radiation sensor, and an optical fiber disposed between the radiation sensor and the optically transparent window, wherein the optically transparent window is disposed at one end of the body, and the resistive heating element is disposed inside the body. The body further comprises an outer body and an optically transparent inner body, wherein the optically transparent window is a part of the optically transparent inner body.

[0069] While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the present disclosure may be devised without departing from the basic scope thereof, the scope of which is to be determined by the claims which follow.

Claims

1. A growth rate sensor suitable for use during semiconductor substrate manufacturing, the growth rate sensor comprising: main body; an optically transparent window, the optically transparent window being disposed at one end of the main body; a silicon-containing coupon disposed within the body and adjacent to the optically transparent window; a resistive heating element disposed within the body and adjacent the optically transparent window; Radiation sensors; and An optical fiber is disposed between the radiation sensor and the optically transparent window.

2. The growth rate sensor of claim 1, wherein the body further comprises: external subject; and An optically transparent inner body, wherein the optically transparent window is part of the optically transparent inner body.

3. The growth rate sensor of claim 1, further comprising a radiation source configured to emit radiation that passes through or is reflected from the silicon-containing sample and is measured by the radiation sensor.

4. The growth rate sensor of claim 1, further comprising one or more mirrors or lenses disposed between the radiation sensor and the optically transparent window.

5. The growth rate sensor of claim 1, further comprising a thermocouple adjacent to the resistive heating element.

6. The growth rate sensor of claim 1, further comprising a cover partially surrounding the silicon-containing coupon and fixing the silicon-containing coupon.

7. The growth rate sensor of claim 6, wherein a gas chamber is provided between the optically transparent window and the silicon-containing sample.

8. The growth rate sensor of claim 7, wherein one or more equalization ports are disposed between the outer surface of the body and the air chamber to allow pressure equalization between the air chamber and a surrounding volume.

9. The growth rate sensor of claim 1, wherein the silicon-containing sample is a silicon carbide substrate.

10. An exhaust assembly suitable for use during semiconductor substrate manufacturing, the exhaust assembly comprising: one or more exhaust passage bodies; an exhaust collector disposed at a distal end of the one or more exhaust passage bodies; a growth rate sensor disposed within the exhaust collector and comprising: Optically clear windows; a silicon-containing sample disposed on a first side of the optically transparent window; and A resistive heating element is disposed on a second side of the optically transparent window.

11. The exhaust assembly of claim 10, wherein the growth rate sensor further comprises: main body; Radiation sensors; and An optical fiber is disposed between the radiation sensor and the optically transparent window, wherein the optically transparent window is disposed at one end of the body, and the resistive heating element is disposed inside the body.

12. The exhaust assembly of claim 10, further comprising an exhaust conduit coupled to the exhaust collector.

13. The exhaust assembly of claim 12, wherein the growth rate sensor is disposed on an inner upper surface of the exhaust collector.

14. The exhaust assembly of claim 13, wherein a radiation source is disposed through an inner lower surface of the exhaust collector and is configured to emit radiation toward the silicon-containing sample.

15. The exhaust assembly of claim 12, wherein the growth rate sensor is disposed on an inner lower surface of the exhaust collector.

16. The exhaust assembly of claim 15, wherein a radiation source is disposed through an interior upper surface of the exhaust collector and is configured to emit radiation toward the silicon-containing sample.

17. The exhaust assembly of claim 10, wherein the silicon-containing coupon is exposed to an exhaust volume within the exhaust collector.

18. A non-transitory computer readable medium storing instructions which, when executed by a processor, cause a system to: monitoring the intensity of radiation reflected by or transmitted through a growth rate sensor, the growth rate sensor comprising: Optically clear windows; a silicon-containing sample disposed on a first side of the optically transparent window; and a resistive heating element disposed on a second side of the optically transparent window; and heating the sensor sample using the resistive heating element during monitoring of the radiation intensity; and Based on the change in the radiation intensity, the growth rate of the film deposited on the sensor sample is determined.

19. The medium of claim 18, wherein the growth rate sensor is located in an exhaust volume of a processing chamber.

20. The medium of claim 19, wherein the growth rate of the film deposited on the sensor coupon is related to a growth rate on a substrate within a processing volume of the processing chamber.

Images