In-situ growth rate sensor using epitaxial self-heating sensor tube

Abstract

This specification describes a method and apparatus for determining the growth rate on a semiconductor substrate. The apparatus is an optical sensor such as an optical growth rate sensor. The optical sensor is positioned in the exhaust of the deposition chamber. The optical sensor self-heats using one or more internal heating elements such as resistive heating elements. The internal heating element is configured to heat the sensor coupon. A film is formed on the sensor coupon by the exhaust gas flowing through the exhaust, which correlates with the film growth on the substrate within the process region of the deposition chamber.

Description

[Technical Field]

[0001]

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

[0002]

[0002] Semiconductor substrates are processed for various applications including the manufacture of integrated devices and microdevices. One method of substrate processing 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 a thin, ultra-pure layer, typically of silicon or germanium, on the surface of a substrate. Materials can be deposited in a lateral flow chamber by flowing a process gas parallel to the surface of a substrate positioned on a support, thermally decomposing the process gas, and depositing the material from the process gas onto the substrate surface.

[0003]

[0003] Film thickness measurement of a processed substrate may be used in connection with processing steps. Film thickness measurement may be performed outside the process chamber where the processed substrate is processed, after the processing step has been performed (e.g., offline). Offline measurement may lead to inefficiency and reduced throughput, because substrates that do not meet specifications may not be used, and processing may be repeated several times to obtain measurements that meet specifications.

[0004]

[0004] Furthermore, performing film thickness measurement inside a process chamber during processing is difficult because processing equipment within the process chamber may interfere with the measurement equipment, thereby impairing measurement accuracy. For example, the radiation from infrared lamps and the heat emitted by the lamps can interfere with measurement equipment.

[0005]

[0005] Therefore, improved apparatus and methods are needed for measuring film thickness in situ in a processing chamber. [Overview of the Initiative]

[0006]

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

[0007]

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

[0008]

[0008] Another embodiment describes an exhaust assembly suitable for use during the manufacturing of a semiconductor substrate. The exhaust assembly includes one or more exhaust passage bodies, an exhaust collector located at the distal end of one or more exhaust passage bodies, and a growth rate sensor located within the exhaust collector. The growth rate sensor includes an optically transparent window, a silicon-containing coupon located on a first side of the optically transparent window, and a resistance heating element located on a second side of the optically transparent window.

[0009]

[0009] Another embodiment describes a process chamber suitable for use during processing of a semiconductor substrate. The process chamber includes a chamber body, a substrate support disposed within the process area of ​​the chamber body, an upper window disposed above the substrate support and the process area, a lower window disposed below the substrate support and the process area, a gas injector disposed within the chamber body, an exhaust system disposed on the opposite side of the gas injector within the chamber body, 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 resistance heating element disposed on a second side of the optically transparent window.

[0010]

[0010] Another embodiment describes a non-transient computer-readable medium. The non-transient computer-readable medium stores instructions that, when executed by a processor, cause a computer system to perform several process steps. The process steps 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 resistance heating element disposed on a second side of the optically transparent window. The process steps further include heating the sensor coupon using the internal heating element while monitoring the intensity of radiation, and determining the growth rate of a film deposited on the sensor coupon from the change in radiation intensity.

[0011]

[0011] In order to understand the features of the present disclosure described above in detail, the present disclosure summarized above will be described more specifically with reference to embodiments illustrated in part in the accompanying drawings. However, it should be noted that the accompanying drawings are merely illustrative embodiments and should not be considered limiting in scope, and other equally valid embodiments are also permissible. [Brief explanation of the drawing]

[0012] [Figure 1]This is a schematic diagram of a deposition chamber according to an embodiment of the present disclosure. [Figure 2] This is a cross-sectional plan view showing the deposition chamber of Figure 1 according to an embodiment of the present disclosure. [Figure 3] This is a cross-sectional side view showing the exhaust system of the deposition chamber shown in Figure 1, according to an embodiment of the present disclosure. [Figure 4A] This figure shows a growth rate monitor for use in the deposition chamber shown in Figure 1, according to an embodiment of the present disclosure. [Figure 4B] This figure shows a growth rate monitor for use in the deposition chamber shown in Figure 1, according to an embodiment of the present disclosure. [Figure 4C] This figure shows a growth rate monitor for use in the deposition chamber shown in Figure 1, according to an embodiment of the present disclosure. [Figure 4D] This figure shows a growth rate monitor for use in the deposition chamber shown in Figure 1, according to an embodiment of the present disclosure. [Figure 5] This is a schematic diagram showing a substrate processing method according to an embodiment of the present disclosure. [Modes for carrying out the invention]

[0013]

[0017] For ease of understanding, the same reference numerals are used to indicate identical elements common to the drawings whenever possible. Elements and features of one embodiment are considered to be usefully incorporated into other embodiments without further detail.

[0014]

[0018] This disclosure relates to an exhaust assembly and growth rate sensor in a semiconductor process chamber. The growth rate sensor performs in-situ monitoring of film growth in the processing chamber. As an example, embodiments disclosed herein provide apparatus and methods for in-situ monitoring of film growth and measurement of film thickness in a processing chamber such as an epitaxial deposition chamber.

[0015]

[0019] Embodiments disclosed herein provide a growth rate sensor positioned in the exhaust of a processing chamber such that an epitaxial film grows thereon. Film growth on the growth rate sensor simulates epitaxial film growth occurring simultaneously on a substrate positioned within the processing chamber. The growth rate sensor is heated to have a temperature similar to that of the substrate in the process region of the processing chamber.

[0016]

[0020] Embodiments disclosed herein enable the substrate and / or coupon to have a temperature similar to that of the substrate being processed in the processing chamber in order to simulate the film deposition characteristics of the substrate.

[0017]

[0021] Embodiments disclosed herein provide a sensor window and a substrate / coupon having a composition that enables backside spectral wavelength measurement in either reflection mode, transmission mode, or both reflection mode and transmission mode.

[0018]

[0022] Embodiments disclosed herein provide a sensor assembly that enables spectroscopic reflectance measurement with low signal-to-noise ratio characteristics inside an epitaxial deposition chamber. Noise includes noise resulting from 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 including a resistance heating element for controlling the temperature of the growth rate sensor. The resistance heating element increases the temperature of the sensor window, advantageously increasing the temperature of the sensor window and the substrate / coupon 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 the flow of process gas.

[0019]

[0023] Self-heating of the growth rate sensor using a resistive heating element or other heating element allows flexible installation of the growth rate sensor at various locations in a process chamber. Since self-heating of the growth rate sensor prevents a decrease in detection sensitivity accompanying changes to the sensor's position, improved sensitivity can be maintained even when the installation location of the growth rate sensor is flexible. Additionally, the use of a self-heating sensor as an in-situ growth rate sensor also reduces the need for signal modulation. Furthermore, the window of the growth rate sensor and the heating of the substrate / coupon support regeneration of the substrate / coupon during a cleaning process in the process chamber.

[0020]

[0024] In some embodiments, the growth rate sensor is positioned within an exhaust such that gas flow is supplied across the growth rate sensor, and radiation emitted by a lamp or other radiation source in the process region is reduced. The reduction in background radiation can enable a broader wavelength range that can be used by the growth rate sensor when determining growth rate.

[0021]

[0025] 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.

[0022]

[0026] Figure 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 for growing an epitaxial film on a substrate such as the substrate 102. The deposition chamber 100 generates cross-flow of a precursor over the entire top surface 150 of the substrate 102.

[0023]

[0027] The deposition chamber 100 includes an upper body 156, a lower body 148 positioned below the upper body 156, and a flow module 112 positioned between the upper body 156 and the lower body 148. The upper body 156, the flow module 112, and the lower body 148 form the chamber body. Located 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 illustrated, 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 positioned between the upper window 108 and the lower window 110. The plurality of upper lamps 141 are positioned between the upper window 108 and the lid 154. The plurality of upper lamps 141 form part of an upper lamp module 155. The lid 154 may include a plurality of sensors (not shown) positioned inside to measure the temperature inside the deposition chamber 100. Multiple lower lamps 143 are positioned between the lower window 110 and the floor 152. The multiple lower lamps 143 form part of the lower lamp module 145. The upper window 108 is an upper dome and is made of an energy-permeable material such as quartz. The lower window 110 is a lower dome and is made of an energy-permeable material such as quartz.

[0024]

[0028] The process area 136 is formed between the upper window 108 and the lower window 110. The process area 136 has a substrate support 106 disposed inside. The substrate support 106 includes a top surface on which the substrate 102 is placed. 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 adjusters that provide movement and / or adjustment of the shaft 118 and / or the substrate support 106 within the process area 136.

[0025]

[0029] The substrate support 106 may include internally located lift pin holes 107. The lift pin holes 107 are sized to accommodate lift pins 132 for lifting the substrate 102 from the substrate support 106 either before or after the deposition process is performed. The lift pins 132 can rest on lift pin stoppers 134 when the substrate support 106 is lowered from the process position to the transfer position.

[0026]

[0030] The flow module 112 includes a plurality of process gas inlets 114, a plurality of purge gas inlets 164, and one or more exhaust gas outlets 116. The plurality of process gas inlets 114 and the plurality of purge gas inlets 164 are located on the flow module 112 opposite to the one or more exhaust gas outlets 116. One or more flow guides are located below the plurality of process gas inlets 114 and the one or more exhaust gas outlets 116. The flow guides are located above the purge gas inlets 164. A liner 163 is located on the inner surface of the flow module 112 to protect the flow module 112 from reactive gases used during the deposition process. The process gas inlets 114 and the purge gas inlets 164 are positioned to allow gas to flow parallel to the upper surface 150 of the substrate 102 located within the process area 136. The process gas inlets 114 are fluidically connected to a process gas source 151. The purge gas inlets 164 are fluidically connected to a purge gas source 162. One or more exhaust gas outlets 116 are fluidly connected to an exhaust pump 157.

[0027]

[0031] One or more exhaust gas outlets 116 are further connected to or include an exhaust system 178. The exhaust system 178 fluidly connects one or more exhaust gas outlets 116 to an 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 optical modules 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. A first optical fiber cable 165a optically couples the first growth monitor 160a to the first optical module 167a. A second optical fiber cable 165b optically couples the second growth monitor 160b to the second optical module 167b.

[0028]

[0032] Figure 2 is a cross-sectional plan view showing the deposition chamber 100 of Figure 1 according to an embodiment of the present disclosure. The deposition chamber 100 includes an injector 202 located opposite the exhaust system 178. The injector 202 includes a process gas inlet 114 and is fluidly coupled to a process gas source 151. The injector 202 may be located through or as part of at least a portion of the flow module 112. The exhaust system 178 is located on the opposite side of the process region 136 from the injector 202. The exhaust system 178 is formed through or attached to the flow module or as part of the flow module.

[0029]

[0033] The exhaust system 178 further includes at least one exhaust passage body 204a, 204b. The exhaust passage bodies 204a, 204b form exhaust passages for gases leaving the process area 136 before entering the exhaust collector 206. As shown in Figure 2, there is a first exhaust passage body 204a and a second exhaust passage body 204b. The first exhaust passage body 204a and the second exhaust passage body 204b may be mirror images and similar in size and configuration. In other embodiments, there may be more or fewer exhaust passage bodies 204a, 204b. In some embodiments, there is only one exhaust passage body, with two exhaust passage bodies 204a, 204b integrated into a single body. In yet another embodiment, there may be three or more exhaust passage bodies, for example, three exhaust passage bodies 204a, 204b. The size and configuration of the exhaust passage bodies 204a, 204b may be modified according to the size and process of the deposition chamber 100.

[0030]

[0034] Both the first exhaust passage body 204a and the second exhaust passage body 204b are coupled to an exhaust collector 206 at the ends of the exhaust passage bodies 204a and 204b opposite the process area 136. The exhaust collector 206 is configured to collect exhaust from the first exhaust passage body 204a and the second exhaust passage body 204b. The exhaust collector 206 narrows as it moves away from the exhaust passage bodies 204a and 204b. Growth monitors 160a and 160b are located within the exhaust collector 206. The growth monitors 160a and 160b are located adjacent to the inlets from the exhaust passage bodies 204a and 204b to the exhaust collector 206. The growth monitors 160a and 160b may be located at various positions within the exhaust collector 206 and / or within the exhaust passage bodies 204a and 204b. Additional growth monitors 208a, 208b, and 208c may be located within the exhaust collector 206 and / or the exhaust passage body 204a and 204b. The additional growth monitors 208a, 208b, and 208c may be similar to growth monitors 160a and 160b, or may be different types of growth monitors, such as crystal oscillator growth monitors.

[0031]

[0035] Figure 3 is a cross-sectional side view showing the exhaust system 178 of the deposition chamber 100 in Figure 1. Inside each exhaust passage body 204a, 204b is an exhaust plenum. The exhaust plenum 312a of the first exhaust passage body 204a is shown, and a similar second exhaust plenum is positioned through the second exhaust passage body 204b. As shown in Figure 3, the exhaust plenum 312a of the exhaust system 178 extends through at least a portion of the flow module 112 so that the exhaust plenum 312a extends through the side wall of the flow module 112 and interacts with the process area 136.

[0032]

[0036] The gas is exhausted from the process area 136 into the exhaust plenum 312a. From the exhaust plenum 312a, the gas flows further into the collector plenum 316. The collector plenum 316 is a plenum located within the exhaust collector 206.

[0033]

[0037] One or more growth monitors 160a, 160b are located either within the exhaust plenum 312a or within the collector plenum 316. The first growth monitor 160a is located within the inner upper surface 324 of the exhaust collector 206 and collector plenum 316. The second growth monitor 160b is located within the inner lower surface 327 of the exhaust collector 206 and collector plenum 316. In lieu of, or in addition to, the arrangement of growth monitors 160a, 160b within the exhaust collector, one or more similar growth monitors are located inside the inner upper surface 326 or inner lower surface 329 of the exhaust passage bodies 204a, 204b and connected to the exhaust plenum 312a. By positioning the growth monitors 160a and 160b on either the inner upper surface 324 or the inner lower surface 327 of the collector plenum 316, the growth monitors 160a and 160b can accumulate on the sensor coupons 362a and 362b without obstructing the exhaust gas flow path. The first growth monitor 160a includes a sensor coupon 362a oriented downward and facing the inner lower surface 328. The second growth monitor 160b includes a second sensor coupon 362b oriented upward and facing the inner upper surface 324.

[0034]

[0038] The exhaust gas passes over the growth monitors 160a and 160b and enters the collector plenum 316 before being removed from the exhaust collector 206 through the conduit opening 306 of the exhaust conduit 323. The conduit opening 306 is located on the portion of the collector plenum 316 opposite to the end of the collector plenum 316 adjacent to the exhaust plenum 312a and the exhaust passage bodies 204a and 204b. The conduit opening 306 is configured to allow the exhaust gas in the exhaust collector 206 to be discharged to the exhaust pump 157 through the exhaust conduit 323. The rear side wall 321 of the exhaust plenum 312a may be located adjacent to the conduit opening 306 and configured to guide the gas into the conduit opening 306. The conduit opening 306 is located through the inner lower surface 327 of the collector plenum 316 and opens into the exhaust conduit 323. The exhaust conduit 323 extends downward from the conduit opening 306 and is fluidly connected to the exhaust pump 157.

[0035]

[0039] Figures 4A to 4D show different embodiments of growth monitors 160a, 160b, 160c, and 160d for use in the deposition chamber of Figure 1. Each of the growth monitors 160a, 160b, 160c, and 160d is configured to measure changes in the transmission and / or reflection of radiation through a coupon such as sensor coupon 362a in Figures 4A and 4C or sensor coupon 362b in Figures 4B and 4D. Changes in the transmission and / or reflection of radiation through the coupon are caused by the growth of film 476 on sensor coupons 362a and 362b. As film 476 grows, the wavelength and intensity of radiation passing through or reflected from sensor coupons 362a and 362b change and are measured to determine the growth rate of film 476. The growth rate of film 476 can be correlated with the growth rate on a substrate such as substrate 102 in the deposition chamber 100. The growth monitors 160a, 160b, 160c, and 160d are heated using one or more heating elements. The one or more internal heating elements may be resistance heating elements, Peltier elements, infrared (IR) heating elements, or heating fluid conduits. Other heating devices are also conceivable 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 coupons 362 and 362b.

[0036]

[0040] Figure 4A shows a first embodiment of the growth monitor 160a. The growth monitor 160a in Figure 4A includes an outer body 402 and an optically transparent inner body 463. The growth monitor 160a is positioned so that it penetrates the inner upper surface 324. The growth monitor 160a is also configured to include a radiation source 434 located in the first optical module 167a. By placing the radiation source 434 together with the radiation sensor 436 within the first optical module 167a, the growth monitor 160a in Figure 4A becomes a reflective monitor, enabling the measurement of radiation reflected by the sensor coupon 362a from the radiation beam emitted by the radiation source 434. The first optical module 167a can also use background radiation passing through the sensor coupon 362a from the collector plenum 316 instead of the radiation source 434.

[0037]

[0041] The radiation sensor 436 may include an optical spectrometer. Other radiation sensors 436 are also conceivable and can be used. The radiation measured by the radiation sensor 436 is in the range of approximately 0.5 μm to approximately 6 μm, for example, approximately 1 μm to approximately 5 μm, for example, approximately 2 μm to approximately 4 μm. The radiation emitted by the radiation source 434 is in the range of approximately 0.5 μm to approximately 6 μm, for example, approximately 1 μm to approximately 5 μm, for example, approximately 2 μm to approximately 4 μm.

[0038]

[0042] 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 positioned so as to penetrate the inner upper surface 324 and the wall of the exhaust system 178, such that the bottom of the growth monitor 160a is exposed to exhaust gas passing through the collector plenum 316 and 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 transmittance of 90% or more to radiation with wavelengths from about 0.2 μm to about 5.0 μm, for example from about 0.5 μm to about 5.0 μm, or for example from about 1.0 μm to about 4.5 μm. The wavelengths to which the transparent inner body 463 is transparent may be at least partially affected by the type of heat 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 positioned adjacent to the collector plenum 316. The optically transparent window 462a may be made of the same material as the rest of the transparent inner body 463, or it may be made of a different material.

[0039]

[0043] The sensor coupon 362a is positioned adjacent to the optically transparent window 462a and the transparent inner body 463. The sensor coupon 362a includes a deposition surface 428a and a back surface 430a. The deposition surface 428a is oriented toward the inner lower surface 327. The film 476 grows on the deposition surface 428a during the processing step and correlates with film growth on the substrate within the process area of ​​a semiconductor processing chamber such as the deposition chamber 100.

[0040]

[0044] In the growth monitor 160a, the sensor coupon 362a is secured to the transparent inner body 463 using a cover 404. The cover 404 is configured to partially surround the sensor coupon 362a so that the cover 404 can secure the sensor coupon 362a. As shown in Figure 4A, the outer edge of the deposition surface 428a of the sensor coupon 362a is covered by the cover 404 and held in place to secure the sensor coupon 362a. The central portion of the deposition surface 428a of the sensor coupon 362a remains uncovered and is exposed to the collector plenum 316.

[0041]

[0045] A rear sensor plenum 408 is formed above the sensor coupon 362a, between the back surface 430a and the optically transparent window 462a. The rear sensor plenum 408 reduces the pressure that may be applied to the sensor coupon 362a by the cover 404 when the cover 404 holds the back surface 430a coplanar with the optically transparent window 462a. When the rear sensor plenum 408 is used, a pressure difference may occur between the rear sensor plenum 408 and the collector plenum 316 during processing. Therefore, to prevent damage to the sensor coupon 362a due to the pressure difference, one or more equalization ports (not shown) can be placed between the outer surface of the transparent inner body 463 and the rear sensor plenum 408 to allow for equalization of pressure between the rear sensor plenum 408 and the surrounding area such as the collector plenum 316.

[0042]

[0046] The cover 404 may include a coupon transfer opening 406. The coupon transfer opening 406 may be positioned either upstream or downstream. The coupon transfer opening 406 is configured to allow the transfer of the sensor coupon 362a in and out of the cover 404. Thus, the bottom surface of the cover 404 functions as a shelf, and the coupon transfer opening 406 may have a surface coplanar with the support surface of the cover 404 that supports the sensor coupon 362a. The coupon transfer opening 406 has a width at least the same size as the width of the sensor coupon 362a. Thus, the coupon transfer opening 406 is a rectangular or arc-shaped opening that penetrates the transparent inner body 463. The coupon transfer opening 406 can be patched or filled before positioning the transparent inner body 463 inside the collector plenum 316. The patch or filler may be a plug. The material of the patch or filler is the same material as the transparent inner body 463 and can be coated or positioned using a high-temperature coating process.

[0043]

[0047] In one or more examples, the thickness of the sensor coupon 362a is about 400 μm or less, for example, from about 200 μm to about 400 μm, for example, from about 250 μm to about 350 μm, for example, about 300 μm. The thickness of the sensor coupon 362a is configured to reduce the attenuation of radiation passing through it. In one or more examples, the sensor coupon 362a has a crystalline structure. A sensor coupon 362a with a crystalline structure favorably increases radiation transmission and thermal conductivity compared to the corresponding amorphous material. Thus, heat and radiation can be easily transferred between the optically transparent window 462a and the sensor coupon 362a. Thus, heating of the sensor coupon 362a is more predictable and uniform, and radiation from a radiation source can easily pass through the sensor coupon 362a and be measured. In one embodiment, which can be combined with other embodiments, the sensor coupon 362a is a silicon-containing coupon. In one embodiment, the sensor coupon 362a is formed from silicon carbide (e.g., SiC). Other materials are also conceivable for the sensor coupon 362a. A silicon carbide sensor coupon 362a is advantageous because, in contrast to a sensor coupon 362a made solely of silicon, it provides a spectral transmission signal to any silicon-based doped or undoped film deposited thereon. In one embodiment, which can be combined with other embodiments, the sensor coupon 362a is crystalline silicon carbide. The crystalline structure of the sensor coupon 362a is 6H, 4H, 3C, or a combination thereof.

[0044]

[0048] The deposition surface 428a of the sensor coupon 362a has a roughness of less than 3 nm, for example, less than 2 nm, for example, less than 1 nm. In one embodiment, which can be combined with other embodiments, the transparent inner body 463 and the optically transparent window 462a are formed from 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 conceivable and can be used within the transparent inner body 463. The material and shape of the transparent inner body 463 are configured to reduce stray light radiation passing through the transparent window 462a and into the transparent inner body 463. The stray light radiation is reduced at wavelengths from about 300 nm to about 1000 nm, for example, from about 400 nm to about 800 nm.

[0045]

[0049] The outer body 402 is made of a metallic material and may be configured to absorb any radiation leaking from the transparent inner body 463. The outer body 402 is made of a metallic material such as stainless steel. Other materials are also conceivable 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 conceivable and can be used as plating or a coating within the outer body 402. Both the outer body 402 and the transparent inner body 463 have a cylindrical outer wall and a cylindrical inner wall. 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.

[0046]

[0050] An internal heating element 411 is located within the outer body 402 and the transparent inner body 463. The internal heating element 411 may be a resistance heating element, a Peltier element, or a heating fluid conduit. Other heating devices are also conceivable and can be used as the internal heating element 411. In the embodiments described herein, the internal heating element 411 is a resistance heating element. The internal heating element 411 provides rapid and accurate control of the temperature of the sensor coupon 362a. In some embodiments, the internal heating element 411 heats the sensor coupon 362a and can control the heating of the sensor coupon 362a from about 300°C to about 1200°C, for example from about 400°C to about 1000°C, for example from about 500°C to about 900°C. The temperature of the sensor coupon 362a is controlled to an accuracy of less than about 10°C, for example less than about 7°C, for example less than 5°C.

[0047]

[0051] 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, and its resistivity is more than 10 times higher than that of the low-resistance element 412, for example, more than 20 times higher than that of the low-resistance element 412, for example, more than 50 times higher than that of the low-resistance element 412. The high-resistance element 410 is positioned adjacent to the optically transparent window 462a and the sensor coupon 362a. The high-resistance element 410 is approximately 10 3 From Ω·cm to approximately 10 6 Ω·cm, for example from approximately 2000Ω·cm to approximately 10000Ω·cm, for example from approximately 10 4 From Ω·cm to approximately 10 5 Ω·cm, for example, about 10 5 From Ω·cm to approximately 10 6 The low-resistance element 412 has a resistivity of Ω·cm. The low-resistance element 412 has a resistivity ranging from about 0.1 Ω·cm to about 100 Ω·cm, for example from about 1 Ω·cm to about 10 Ω·cm, for example from 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 heat up when power is applied to it.

[0048]

[0052] A temperature measuring device 414 is positioned adjacent to 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 / or the sensor coupon 362a. The temperature measuring device 414 of the growth monitor 160 is a thermocouple or a pyrometer. Other temperature measuring devices are also conceivable and can be used as the temperature measuring device 414. The temperature measuring device 414 is coupled to a temperature measuring receiver 418 by wiring 416. The temperature measuring receiver 418 is configured to apply power to a thermocouple and measure the voltage of the thermocouple and the corresponding voltage change. In some embodiments, the temperature measuring receiver 418 is integrated into the controller 120. In some embodiments, the bandgap absorption of the sensor coupon 362a and / or the optically transparent window 462 is measured to determine the temperatures of the optically transparent window 462 and the sensor coupon 362a. This may be an addition to the temperature measuring device 414, or a replacement for the temperature measuring device 414.

[0049]

[0053] The growth monitor 160a further includes one or more lenses 424 and one or more mirrors 422. The lenses 424 and mirrors 422 are configured to collimate and orient radiation between the sensor coupon 362a and the radiation sensor 436. A partition 432 is positioned between the lower end and the upper end of the growth monitor 160a. The lower end includes a high-resistance element 410, a low-resistance element 412, the sensor coupon 362a, an optically transparent window 462a, an optically transparent inner body 463, and a temperature measuring device 414. The upper end includes one or more lenses 424 and one or more mirrors 422. The partition can reduce stray light radiation interacting with one or more lenses 424 and one or more mirrors 422.

[0050]

[0054] One or more optical fiber cables 420, 165a are arranged along the radiation measurement path 425. The first optical fiber cable 165a is located between the first optical module 167a and the body of the growth monitor 160a. The second optical fiber cable 420 is located between the optically transparent window 462 / sensor coupon 362a and the mirror 422 / lens 424. In some embodiments, the second optical fiber cable 420 is omitted.

[0051]

[0055] Figure 4B shows a second embodiment of the growth monitor 160b. The growth monitor 160b in Figure 4B is similar to the growth monitor 160a in Figure 4A, but the growth monitor 160b is positioned to penetrate the inner lower surface 327 of the exhaust collector 206.

[0052]

[0056] The growth monitor 160b is also configured to include a radiation source 434 and a radiation sensor 436 located in the second optical module 167b. By placing the radiation source 434 together with the radiation sensor 436 within the second optical module 167b, the growth monitor 160b in Figure 4B becomes a reflective monitor capable of measuring radiation reflected by the sensor coupon 362b from the radiation beam emitted by the radiation source 434. The second optical module 167b can also use background radiation passing through the sensor coupon 362b from the collector plenum 316 instead of the radiation source 434.

[0053]

[0057] In the growth monitor 160b, the sensor coupon 362b is positioned with its deposition surface 428 facing upward so that the deposition surface 428 faces the inner upper surface 324. The sensor coupon 362b is positioned on the optically transparent window 462b such that the back surface 430b of the sensor coupon 362b is positioned on the optically transparent window 462b. By positioning the sensor coupon 362b on the optically transparent window 462b, gravity holds the sensor coupon 362b on the optically transparent window 462b, making it possible to eliminate the cover 404 of the growth monitor 160a in Figure 4A. The sensor coupon 362b is positioned in the pocket 435. The pocket 435 is a concave opening configured to receive the sensor coupon 362b. The optically transparent window 462b is the bottom surface of the pocket 435. Since the sensor coupon 362b is positioned on the same plane as the optically transparent window 462b, there is no rear sensor plenum 408 or equalization ports 406a, 406b. Therefore, the entire deposition surface 428 is exposed to exhaust gas.

[0054]

[0058] Figure 4C shows a third embodiment of the growth monitor 160c. The growth monitor 160c in Figure 4C is similar to the growth monitor 160a in Figure 4A, except that the radiation source 434 is separated from the radiation sensor 436 and is positioned so that the radiation passes through the sensor coupon 362a. Therefore, the growth monitor 160c measures the radiation that has passed through the sensor coupon 362a, rather than the radiation reflected from the sensor coupon 362a. The radiation outlet 440 is positioned to pass through the inner lower surface 327 of the exhaust collector 206.

[0055]

[0059] Figure 4D shows a fourth embodiment of the growth monitor 160d. The growth monitor 160d in Figure 4D is similar to the growth monitor 160b in Figure 4B, except that the radiation source 434 is separated from the radiation sensor 436 and is positioned so that the radiation passes through the sensor coupon 362b. Therefore, the growth monitor 160d measures the radiation that has passed through the sensor coupon 362b, rather than the radiation reflected from the sensor coupon 362b. The radiation outlet 440 is positioned to pass through the inner upper surface 324 of the exhaust collector 206.

[0056]

[0060] Figure 5 is a schematic diagram showing a substrate processing method 500. In one or more examples, method 500 may be performed using one of the exemplary processing chambers and / or sensor assemblies disclosed herein. In one or more examples, method 500 may be in the form of instructions stored on a computer-readable medium (e.g., memory) and executed by the system's processor (e.g., CPU) to cause the system to perform method 500. The computer-readable medium and the corresponding system are part of a controller, such as controller 120.

[0057]

[0061] In step 502, a film is simultaneously deposited on a substrate such as a substrate 102 and on a sensor coupon of a growth rate sensor such as a sensor coupon 362a or 263b, which are placed in a processing chamber such as a deposition chamber 100. Film deposition involves heating the substrate by flowing one or more precursor or process gases from a process gas source. The process gas is flowed as a side drop onto the substrate surface while the substrate is rotated on a substrate support or susceptor. In step 504, the sensor coupon and the optically transparent window to which the sensor coupon is coupled are heated using an internal heating element such as an internal heating element 411 in the growth rate sensor. In one embodiment that can be combined with other embodiments, heating the sensor coupon and the optically transparent window at least partially through the internal heating element includes applying power to a resistance heating element located in the growth rate sensor. The internal heating element is heated to a predetermined temperature similar to the temperature of the substrate being processed in the process area. The difference between the substrate temperature and the coupon temperature during step 504 is less than about 50°C, for example less than about 30°C, for example less than about 20°C. The temperature of the coupon and / or internal heating element is measured individually using a temperature measuring device such as a thermocouple.

[0058]

[0062] In step 506, the intensity of radiation reflected by or transmitted through the sensor window is measured using an optical spectrometer, which is part of the radiation sensor. During step 506, radiation may also be emitted by a radiation source. The radiation source may be a laser or an optical fiber. The radiation emitted by the radiation source, as measured by the optical spectrometer, is approximately 0.5 μm to approximately 6 μm, for example, approximately 1 μm to approximately 5 μm, for example, approximately 2 μm to approximately 4 μm.

[0059]

[0063] In step 508, the thickness or growth rate of the film deposited on the crystal sensor window is determined based on the measured radiation intensity. In one embodiment, which can be combined with other embodiments, the determination of thickness and / or growth rate includes measuring multiple radiation intensity values ​​of radiation (which may include transmitted radiation and / or reflected radiation) over one or more time intervals. The multiple radiation intensity values ​​are correlated with reference data or a physical model based on Fresnel's equation for electromagnetic reflection to determine the growth rate over one or more time intervals. The growth rate and / or thickness (e.g., change in thickness) may correspond to changes in radiation intensity over one or more time intervals. In one or more examples, the film thickness can be determined using the growth rate at a particular time interval.

[0060]

[0064] Each of the growth monitors 160a, 160b, 160c, and 160d described herein can be used with the deposition chamber 100 or additional versions of semiconductor processing chambers described herein. In some embodiments, the growth monitors 160a, 160b, 160c, and 160d are located in semiconductor processing chambers other than those described herein, such as atomic layer deposition (ALD) chambers, physical vapor deposition (PVD) chambers, and other versions of chemical vapor deposition (CVD) chambers. By arranging the growth monitors 160a, 160b, 160c, and 160d, the amount of stray light emission from the lamp or other heating element is reduced compared to when the growth monitors 160a, 160b, 160c, and 160d are located inside the process area 136 of the deposition chamber 100. However, by positioning the growth monitors 160a, 160b, 160c, and 160d inside the exhaust, the growth monitors 160a, 160b, 160c, and 160d are not heated by the same heating element or lamp as the substrate 102. If the growth monitors 160a, 160b, 160c, and 160d are not at the same temperature as the substrate 102, the quality of film growth and film removal from sensor coupons such as sensor coupons 362a, 362b will be reduced. Therefore, the growth monitors 160a, 160b, 160c, and 160d described herein have an internally located internal heating element 411.

[0061]

[0065] The internal heating element 411 makes it possible to maintain the growth monitors 160a, 160b, 160c, and 160d at a temperature similar to that of the substrate 102 while reducing background radiation. By using self-heating growth monitors 160a, 160b, 160c, and 160d, it becomes even more flexible to position the growth monitors 160a, 160b, 160c, and 160d throughout the deposition chamber 100. Therefore, the growth monitors 160a, 160b, 160c, and 160d can be placed in different parts of the exhaust system 178. By positioning the growth monitors 160a, 160b, 160c, and 160d within the exhaust system 178, the complexity of the system inside the process area 136 is further reduced compared to when the growth monitors 160a, 160b, 160c, and 160d are positioned inside the process area 136.

[0062]

[0066] Embodiments of this disclosure describe a process chamber suitable for use during semiconductor substrate processing. The process chamber includes a chamber body, a substrate support disposed within the process area of ​​the chamber body, an upper window disposed above the substrate support and the process area, a lower window disposed below the substrate support and the process area, a gas injector disposed within the chamber body, an exhaust system disposed on the opposite side of the gas injection within the chamber body, 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 resistance heating element disposed on a second side of the optically transparent window.

[0063]

[0067] In some embodiments, the growth rate sensor further includes a body, a radiation sensor, and an optical fiber positioned between the radiation sensor and an optically transparent window, the optically transparent window being located at the end of the body, and a resistance heating element being located inside the body. The body further includes an outer body and an optically transparent inner body, the optically transparent window being part of the optically transparent inner body.

[0064]

[0068] While the foregoing applies to embodiments of the present disclosure, it is possible to devise other further embodiments of the present disclosure without departing from its basic scope as defined by the following claims.

Claims

1. A growth rate sensor suitable for use during the manufacturing of semiconductor substrates, The main unit and An optically transparent window is positioned at the end of the main body, A silicone-containing coupon is placed inside the main body and adjacent to the optically transparent window, A resistance heating element is disposed within the main body and adjacent to the optically transparent window, Radiation sensor and An optical fiber is disposed between the radiation sensor and the optically transparent window. A growth rate sensor equipped with a growth rate sensor.

2. The aforementioned main body further, The outer body and An optically transparent inner body, wherein the optically transparent window is part of the optically transparent inner body, and The growth rate sensor according to claim 1, comprising:

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

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

6. The growth rate sensor according to claim 1, further comprising a cover that partially surrounds the silicon-containing coupon and secures the silicon-containing coupon.

7. The growth rate sensor according to claim 6, wherein a plenum is disposed between the optically transparent window and the silicon-containing coupon.

8. The growth rate sensor according to claim 7, wherein one or more equalization ports are disposed between the outer surface of the main body and the plenum, enabling the equalization of pressure between the plenum and the surrounding area.

9. The growth rate sensor according to claim 1, wherein the silicon-containing coupon is a silicon carbide substrate.

10. An exhaust assembly suitable for use during the manufacturing of semiconductor substrates, One or more exhaust passage bodies, An exhaust collector positioned at the distal end of the one or more exhaust passage bodies, A growth rate sensor disposed within the exhaust collector, The main unit and An optically transparent window is positioned at the end of the main body, A silicon-containing coupon is placed on the first side surface of the optically transparent window, Within the main body, a resistance heating element is provided, which is positioned on the second side of the optically transparent window. Radiation sensor and An optical fiber is disposed between the radiation sensor and the optically transparent window. Includes a growth rate sensor and An exhaust assembly equipped with the following features.

11. The exhaust assembly according to claim 10, further comprising an exhaust conduit coupled to the exhaust collector.

12. The exhaust assembly according to claim 11, wherein the growth rate sensor is located on the inner upper surface of the exhaust collector.

13. The exhaust assembly according to claim 12, wherein the radiation source is positioned to penetrate the inner lower surface of the exhaust collector and is configured to emit radiation toward the silicon-containing coupon.

14. The exhaust assembly according to claim 11, wherein the growth rate sensor is located on the inner lower surface of the exhaust collector.

15. The exhaust assembly according to claim 14, wherein the radiation source is positioned to penetrate the inner upper surface of the exhaust collector and is configured to emit radiation toward the silicon-containing coupon.

16. The exhaust assembly according to claim 10, wherein the silicon-containing coupon is exposed in the exhaust region within the exhaust collector.

17. A non-transient computer-readable medium that, when executed by a processor, allows the system to... Monitoring the intensity of radiation reflected by or transmitted through a growth rate sensor, wherein the growth rate sensor is The main unit and An optically transparent window is positioned at the end of the main body, A silicon-containing coupon is placed on the first side surface of the optically transparent window, Within the main body, a resistance heating element is provided, which is positioned on the second side of the optically transparent window. Radiation sensor and An optical fiber is disposed between the radiation sensor and the optically transparent window, This includes monitoring the intensity of radiation reflected by or transmitted through a growth rate sensor, The sensor coupon is heated using the resistance heating element while monitoring the intensity of the radiation, The growth rate of the film deposited on the sensor coupon is determined from the change in the intensity of the aforementioned radiation. A non-transient, computer-readable medium that stores commands to perform an action.

18. The medium according to claim 17, wherein the growth rate sensor is positioned in the exhaust region of the process chamber.

19. The medium according to claim 18, wherein the growth rate of the film deposited on the sensor coupon correlates with the growth rate on the substrate in the processing area of ​​the process chamber.

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