JP2022160395A - In-line chamber metrology - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device and a system for in-line monitoring that allows in-process inspection of a substrate undergoing vacuum processing.

SOLUTION: A processing chamber 400 includes a first viewport 402 for allowing electromagnetic radiation beams 424 and 426 from one or more lasers 420 and 422 to illuminate a substrate 406 within the processing chamber 400, a second viewport 404 for enabling a detector 430 to detect electromagnetic radiation 432 scattered from the substrate 406, one or more lasers 420 and 422, and a detector 430 operable to detect electromagnetic radiation 432 scattered from the substrate through the second viewport.

SELECTED DRAWING: Figure 4

COPYRIGHT: (C)2023,JPO&INPIT

Description

Embodiments of the present disclosure generally relate to reduced pressure processing systems and processing techniques. More particularly, embodiments of the present disclosure relate to techniques for direct in-line monitoring of substrates in reduced pressure processing systems.

Semiconductor substrates are processed for a wide variety of applications, including the fabrication of devices for integrated circuits and microdevices. One technique for processing a substrate involves exposing the substrate to gases under reduced pressure and depositing a material, such as a dielectric material or a conductive metal, on the surface of the substrate. For example, epitaxy is a deposition process that can be used to grow high-purity thin films, often composed of silicon or germanium, on the surface of a substrate (eg, a silicon wafer). The material is made by flowing a process fluid (e.g., a mixture of a precursor gas and a carrier gas) parallel to and across the surface of a substrate disposed on a support, and flowing a process fluid (e.g., a process fluid (by heating to a high temperature) and depositing material from the process fluid onto the surface of the substrate in a cross-flow chamber.

At various times during processing of the substrate, the quality of the deposited film can be inspected and/or measured. A previously known technique for inspecting and/or measuring a substrate involves removing the substrate from the processing chamber and placing the substrate in a meter for inspecting and/or measuring the substrate. Removal of the substrate from the processing chamber may result in gas entering the processing chamber, possibly evacuating the processing chamber by a vacuum pump before processing (of the substrate or other substrates) in the chamber continues. need to be in a state.

To improve processing chamber throughput and the quality of substrates produced, a means of inspecting and/or measuring substrates undergoing processing in a processing system without removing the substrate from the high vacuum environment of the processing system is provided. is necessary.

An apparatus is provided for processing a substrate. The apparatus generally includes a processing chamber body having a first viewport and a second viewport, a source connected to the processing chamber body for supplying processing fluid, and a vacuum connected to the processing chamber body. a pump, a substrate support within a processing chamber body, an electromagnetic radiation emitter operable to illuminate a substrate on the substrate support through a first viewport, and electromagnetic radiation scattered from the substrate through a second viewport. a detector operable to detect radiation.

A system is provided for processing a substrate. The system generally:
a processing chamber having a first slit valve opening configured to allow passage of a substrate and a second slit valve opening configured to allow passage of a substrate;
a first slit valve operable to open and close a first slit valve opening of the processing chamber, the first slit valve operable to form a first hermetic seal when closed;
a second slit valve operable to open and close a second slit valve opening of the processing chamber, the second slit valve operable to form a second hermetic seal when closed;
a loadlock having a transfer slit valve opening aligned with a second slit valve opening of the processing chamber, a loadlock port, and a substrate support;
a mechanical arm having an encased probe;
A mechanical arm portion is operable to access the interior of the loadlock through the loadlock port, the mechanical arm portion operable to access the substrate on the substrate support by moving the instrumentation within the contained probe. and the contained probe has an emitter operable to emit electromagnetic radiation to illuminate the substrate, and the contained probe detects electromagnetic radiation scattered from the substrate. It has a detector operable as

So that the above-listed features of aspects of the present disclosure may be understood in detail, a more particular description of the aspects briefly summarized above can be had by reference to the embodiments; are shown in the accompanying drawings. However, as the disclosure may permit other equally effective embodiments, the accompanying drawings illustrate only typical embodiments of the disclosure and are therefore to be considered limiting of its scope. Note that it is not

1 illustrates a cross-sectional view of a reduced pressure processing chamber in accordance with aspects of the present disclosure; FIG. 1 illustrates a cross-sectional view of a reduced pressure processing chamber in accordance with aspects of the present disclosure; FIG. 1 illustrates an exemplary processing system in accordance with certain aspects of the present disclosure; 1 shows a schematic isometric view of an exemplary load lock in accordance with aspects of the present disclosure; FIG. 1 shows a schematic isometric view of a processing chamber according to aspects of the present disclosure; FIG. 5 is a set of graphs 500 illustrating atomic layer deposition monitoring in accordance with aspects of the present disclosure. 1 is a schematic diagram of an exemplary sum frequency generation (SFG) spectroscopic monitoring system configured to measure a substrate during processing, in accordance with aspects of the present disclosure; FIG. 1 is a schematic illustration of an exemplary substrate handling blade in accordance with aspects of the present disclosure; FIG.

For ease of understanding, identical reference numbers have been used, where possible, to designate identical elements common to multiple figures. It is contemplated that elements disclosed in one embodiment may be beneficially utilized on other embodiments without specific recitation.

Measure layer thickness and layer uniformity of a substrate being processed in a processing system and/or inspect the substrate for defects without removing the substrate from the high vacuum environment of the processing system. , and/or methods and apparatus are provided for chemical characterization of substrate layers and interfaces between layers. The method and apparatus enable measurement and/or inspection of a substrate without breaking the vacuum of the processing chamber by measuring and/or inspecting the substrate within the processing chamber or within a loadlock chamber connected to the processing chamber. to

One embodiment disclosed herein is a load lock chamber connected to a processing system. The loadlock chamber has a mechanical arm with a contained probe having one or more instruments that can be used to inspect and/or measure the properties or presence of particles on a substrate. The substrate can be removed from the processing chamber and moved into a loadlock, where one or more instruments inspect and/or measure the substrate. The pressure within the loadlock is maintained at a level similar to that of the processing system or processing chamber, allowing substrate measurements and inspection without breaking the vacuum of the processing chamber.

In other embodiments, multiple viewports are positioned over the processing chamber. Lasers, X-ray emitters, and/or other emitters of electromagnetic radiation can illuminate the substrate through a first viewport within the processing chamber, and radiation scattered from the substrate can It can exit the processing chamber through a viewport and be detected, collected, and/or measured by instrumentation external to the processing chamber. A substrate may be inspected and/or measured while the substrate is in the processing chamber without breaking the vacuum of the processing chamber.

As used herein, radiation “scattered” from the substrate refers to radiation that is reflected from the substrate, refracted from the substrate, emitted from the substrate as a result of illumination, and/or transmitted through the substrate.

Semiconductor substrates are processed for a wide variety of applications, including the fabrication of devices for integrated circuits and microdevices. As mentioned above, one technique for processing a substrate involves exposing the substrate to gases under reduced pressure and depositing a material, such as a dielectric material or a conductive metal, on the surface of the substrate. For example, epitaxy is a deposition process that can be used to grow high-purity thin films, often composed of silicon or silicon dioxide, on the surface of a substrate (eg, a silicon wafer). The material is made by flowing a process fluid (e.g., a mixture of a precursor gas and a carrier gas) parallel to and across the surface of a substrate disposed on a support, and flowing a process fluid (e.g., a process fluid (by heating to a high temperature) and depositing material from the process fluid onto the surface of the substrate in a cross-flow chamber. Substrates processed according to the epitaxy techniques described above may be measured and/or inspected in a process chamber or loadlock, as described in more detail below.

Disclosed embodiments include atomic layer deposition (ALD), chemical vapor deposition (CVD), etching, plasma-enhanced chemical vapor deposition (PECVD), physical vapor deposition. It can be used with techniques for processing the substrate including, but not limited to, physical vapor deposition (PVD), dielectric deposition, polymer layer deposition, and selective removal process (SRP).

FIG. 1A shows a schematic cross-sectional view of an exemplary processing chamber 100 with components in position for processing, in accordance with aspects of the present disclosure. The illustrated processing chamber is an epitaxial chamber. Processing chamber 100 is used to process (eg, perform epitaxial deposition on) one or more substrates, including depositing material on the top surface of substrate 108 . The processing chamber 100 includes an array of radiant heat lamps 102 for heating and, among other components, a backside 104 of a substrate support 106 (eg, a susceptor) positioned within the processing chamber 100 . In some embodiments, an array of radiant heat lamps are positioned above the upper dome 128 in addition to the array shown below the lower dome. The substrate support 106 may be a disk-shaped substrate support 106 without a central opening, as shown, or it may be a ring-shaped substrate support.

FIG. 1B shows a schematic side view of processing chamber 100 taken along line 1B-1B of FIG. 1A. Liner assembly 163 and annular shield 167 have been omitted for clarity. The substrate support may be a disc-shaped substrate support 106 as shown in FIG. 1A or a substrate support 106 as shown in FIG. 1B to facilitate exposure of the substrate to the thermal radiation of lamps 102. may be a ring-shaped substrate support 107 that supports the substrate from the edge of the substrate.

Referring to FIGS. 1A and 1B, substrate support 106 or 107 is positioned within processing chamber 100 between upper dome 128 and lower dome 114 . An upper dome 128 , a lower dome 114 , and a base ring 136 positioned between the upper dome 128 and the lower dome 114 define an interior region of the processing chamber 100 . Generally, the central portions of upper dome 128 and lower dome 114 are formed from an optically transparent material such as quartz. The interior region of processing chamber 100 is generally divided into processing region 156 and purge region 158 .

A substrate 108 (not to scale) may be brought into processing chamber 100 through loading port 103 and placed on substrate support 106 . The loading port 103 is obscured by the substrate support 106 in FIG. 1A, but is visible in FIG. 1B.

According to one embodiment, the substrate support 106 is supported by a central shaft 132 that may directly support the substrate support 106, as shown in FIG. 1A. According to another embodiment, central shaft 132 supports disk-shaped substrate support 107 by arms 134, as shown in FIG. 1B.

According to one embodiment, the processing chamber 100 also includes a lamphead 145 that supports the array of lamps 102 and cools the lamps 102 during and/or after processing. Each lamp 102 is coupled to an electrical distribution board (not shown) that supplies electricity to each lamp 102 .

According to one embodiment, processing chamber 100 also includes one or more optical pyrometers 118 that measure the temperature within processing chamber 100 and at the surface of substrate 108 . A controller (not shown) controls the distribution of power from the switchboard to the lamps 102 . The controller also controls the flow of cooling fluid within processing chamber 100 . The controller controls the temperature within the processing chamber by varying the voltage from the switchboard to the lamps 102 and by varying the flow of cooling fluid.

A reflector 122 is positioned above upper dome 128 to reflect infrared radiation emitted from substrate 108 and upper dome 128 back into processing chamber 100 . Reflector 122 is secured to upper dome 128 using clamp ring 130 . Reflector 122 has one or more connection ports 126 connected to a cooling fluid source (not shown). Connection port 126 connects to one or more passages (not shown) within the reflector to allow cooling fluid (eg, water) to circulate within reflector 122 .

According to one embodiment, processing chamber 100 includes a processing fluid inlet 174 connected to a processing fluid supply 172 . Processing fluid inlet 174 is configured to direct a processing fluid (eg, trimethylaluminum (TMA) or silane (SiH ₄ )) generally across the surface of substrate 108 . The processing chamber also includes a processing fluid outlet 178 located on the side of the processing chamber 100 opposite the processing fluid inlet 174 . Process fluid outlet 178 is connected to vacuum pump 180 .

According to one embodiment, processing chamber 100 includes a purge gas inlet 164 formed in the sidewall of base ring 136 . A purge gas source 162 supplies purge gas to a purge gas inlet 164 . Where processing chamber 100 includes an annular shield 167 , annular shield 167 is positioned between process fluid inlet 174 and purge gas inlet 164 . For purposes of illustration, process fluid inlet 174, purge gas inlet 164, and process fluid outlet 178 are shown and their locations, sizes, fluid inlets and fluid The number of outlets, etc. can be adjusted.

A substrate support is shown in a position that allows for processing of a substrate within processing chamber 100 . Central shaft 132, substrate support 106 or 107, and arm portion 134 may be lowered by actuators (not shown). A plurality of lift pins 105 pass through the substrate support 106 or 107 . Lowering the substrate support to a loading position below the processing position allows the lift pins 105 to contact the lower dome 114 and pass through holes in the substrate support 106 to lift the substrate 108 off the substrate support 106 . Become. A robot (not shown in FIG. 1, see robot 208 in FIG. 2) then enters processing chamber 100 and engages substrate 108 through loading port 103 for removal. The robot that retrieved the substrate 108 or another robot enters the processing chamber through the loading port 103 and places an unprocessed substrate on the substrate support 106 . Substrate support 106 is then raised to a processing position by an actuator and an unprocessed substrate is placed in position for processing.

According to one embodiment, processing of substrate 108 within processing chamber 100 includes inserting the substrate through loading port 103 , placing substrate 108 on substrate support 106 or 107 , substrate support 106 Or 107 and substrate 108 are raised to a processing position, heating substrate 108 using lamps 102 , flowing processing fluid 173 over substrate 108 , and rotating substrate 108 . In some cases, the substrate may be raised or lowered during processing.

According to some aspects of the present disclosure, epitaxial processing within processing chamber 100 includes controlling the pressure within processing chamber 100 to be below atmospheric pressure. According to one embodiment, the pressure within processing chamber 100 is reduced to approximately 10 torr to 80 torr. According to another embodiment, the pressure within processing chamber 100 is reduced to approximately 80 torr to 300 torr. According to one embodiment, vacuum pump 180 is activated to reduce the pressure of processing chamber 100 before and/or during processing.

Processing fluid 173 is introduced into processing chamber 100 through one or more processing fluid inlets 174 and exits processing chamber 100 through one or more processing fluid outlets 178 . Processing fluid 173 deposits one or more materials on substrate 108, for example, by thermal decomposition or other reaction. After depositing the material on the substrate 108, effluents (ie, off-gases) 166, 175 are formed from the reaction. Effluents 166 , 175 exit processing chamber 100 through processing fluid outlet 178 .

After processing of substrate 108 is completed, processing chamber 100 is purged of processing fluid 173 and effluents 166 , 175 by introducing purge gas 165 (eg, hydrogen or nitrogen) through purge gas inlet 164 . Purge gas 165 may be introduced through process fluid inlet 174 instead of or in addition to purge gas inlet 164 . Purge gas 165 exits the processing chamber through processing fluid outlet 178 .

Exemplary Inline Chamber Metrology In embodiments of the present disclosure, a substrate may be processed, inspected and/or measured within a processing chamber without breaking the vacuum of the processing chamber. In one embodiment, the loadlock chamber is connected with the processing chamber via a valve. A loadlock has a mechanical arm with a contained probe having one or more instruments that can be used to inspect and/or measure a substrate. A substrate can be removed from the processing chamber, passed through a valve, and into a loadlock, where one or more instruments inspect and/or measure the substrate. The pressure within the loadlock is maintained at or reduced to a level similar to that of the process chamber to allow measurement and inspection of the substrate without breaking the vacuum of the process chamber. The substrate may then be returned to the processing chamber for additional processing, with additional processing parameters (eg, temperature or gas flow rates) determined based on measurements and tests performed at the loadlock.

Measurement and inspection techniques that may be utilized with loadlocks according to aspects of the present disclosure include confocal fluorescence microscopy and imaging, infrared, ultraviolet, and visible reflectance (including ellipsometry), Raman scattering, tip-enhanced Raman scattering, surface plasmon polariton enhanced Raman scattering, second harmonic, sum frequency spectroscopy, atomic force microscopy (AFM), scanning tunneling microscopy (STM), terahertz wave scanning or millimeter Wave scanning and x-ray fluorescence (XRF) are included.

In other embodiments, multiple viewports are positioned over the process chamber. Lasers, X-ray emitters, and/or other emitters of electromagnetic radiation can be projected through the first viewport onto the substrate in the processing chamber and scattered from the substrate (e.g., The radiation (reflected or refracted) exits the processing chamber through a second viewport and can be detected, collected, and/or measured by instrumentation external to the processing chamber. A substrate may be inspected and/or measured while the substrate is in the processing chamber without breaking the vacuum of the processing chamber.

Measurement and inspection techniques that may be utilized with viewports located over the processing chamber, in accordance with aspects of the present disclosure, include confocal fluorescence microscopy and imaging, infrared, ultraviolet, and visible reflectance (including ellipsometry). ), Raman scattering, second harmonic, sum frequency spectroscopy, terahertz or millimeter wave scanning, and X-ray fluorescence (XRF).

FIG. 2 is a top view of an exemplary processing system 200 according to one embodiment of the disclosure. The processing system 200 includes a load lock chamber 204, a transfer chamber 206, a handling (eg, tool and material handling or substrate handling) robot 208 within the transfer chamber 206, a first CVD processing chamber 210, a second CVD It includes a process chamber 212 , a control station 214 , an ALD process chamber 216 and a mask chamber 218 . First CVD processing chamber 210, second CVD processing chamber 212, ALD processing chamber 216, and hardware associated with each chamber are preferably made of, for example, aluminum, anodized aluminum, nickel-plated aluminum, stainless steel, quartz, , and combinations and alloys thereof. The first CVD processing chamber 210, the second CVD processing chamber 212, and the ALD processing chamber 216 may be circular, rectangular, or otherwise shaped as required by the shape of the substrate to be coated and other processing requirements. can be

The transfer chamber 206 includes slit valve openings 221, 223 in the sidewalls adjacent the load lock chamber 204, the first CVD processing chamber 210, the second CVD processing chamber 212, the ALD processing chamber 216, and the mask chamber 218; 225, 227, 229. The handling robot 208 is capable of inserting a substrate handling blade 209 and/or one or more other tools through each of the slit valve openings 221, 223, 225, 227, 229 and into adjacent chambers. Arranged and configured. That is, the handling robot transfers load lock chamber 204, first CVD processing chamber 210, through slit valve openings 221, 223, 225, 227, 229 in the walls of transfer chamber 206 adjacent each of the other chambers. , second CVD processing chamber 212 , ALD processing chamber 216 , and mask chamber 218 . A substrate handling blade, also referred to herein as a "blade," can be equipped with a substrate monitor according to aspects of the present disclosure. An example of such a blade is described below with reference to FIG. When a substrate, tool, or other article is inserted into or removed from one of the adjacent chambers, the slit valve openings 221, 223, 225, 227, 229 are positioned inside the adjacent chamber. are selectively opened and closed by slit valves 220, 222, 224, 226, 228 to allow access to.

Transfer chamber 206, load lock chamber 204, first CVD processing chamber 210, second CVD processing chamber 212, ALD processing chamber 216, and mask chamber 218 are one in fluid communication with a vacuum system (eg, vacuum pump). It contains the above apertures (not shown). The apertures provide exits for gases within the various chambers. In some embodiments, each chamber is connected to a separate and independent vacuum system. In yet another embodiment, some of the chambers share a vacuum system while other chambers have separate independent vacuum systems. The vacuum system may include vacuum pumps (not shown) and throttle valves (not shown) to regulate gas flow through the various chambers.

According to aspects of the present disclosure, first CVD processing chamber 210 may be connected to load lock 211 via valve 215 . The loadlock 211 can have a mechanical arm with a housed probe having one or more instruments that can be used to inspect and/or measure the substrate (see FIG. 3). A substrate is removed from first CVD processing chamber 210 and through valve 215 into loadlock 211 where one or more instruments can inspect and/or measure the substrate. The instrument may comprise a confocal fluorescence microscope or imaging system, one or more infrared, ultraviolet, and/or visible light lasers, one or more charge-coupled device (CCD) detectors, one or more Mercury cadmium telluride (MCT) detectors, one or more indium gallium arsenide (InGaAs) detectors, mechanical probes with tips for tip-enhanced Raman scattering, atomic force microscope probes , a scanning tunneling microscope probe, a terahertz or millimeter wave transceiver antenna, and an x-ray emitter and x-ray detector. The mechanical arms, contained probes, and instruments are described in more detail below with reference to FIG. The pressure within the loadlock 211 can be reduced to or maintained at a similar level as the pressure in the first CVD processing chamber 210, allowing the substrate to be loaded without breaking the vacuum in the first CVD processing chamber 210. can be measured and inspected.

Similarly, a second CVD processing chamber 212 can be connected to load lock 213 via valve 218 and ALD processing chamber 216 can be connected to load lock 217 via valve 219 . Each of the load locks 213 and 217 can have a mechanical arm with housed probes having one or more instruments that can be used to inspect and/or measure the substrate (see FIG. 3). . As described above, the substrate may be removed from second CVD processing chamber 212 into load lock 213 through valve 218 without breaking the vacuum of second CVD processing chamber 212 . Also as noted above, the substrate may be removed from the ALD processing chamber 216 into the loadlock 217 through the valve 219 without breaking the vacuum of the ALD processing chamber 216 . Once within load lock 213 or 217 , the probe's instrumentation may measure and/or inspect the substrate without breaking the vacuum of second CVD processing chamber 212 or ALD processing chamber 216 .

FIG. 3 depicts a schematic isometric view of an exemplary load lock 300 in accordance with aspects of the present disclosure. Loadlock 300 may be an example of loadlocks 211, 213, and 217 shown in FIG. A mechanical arm 302 with an encased probe 304 may access substrate 306 through load lock port 308 . A substrate 306 may be placed on a substrate support 310 (eg, a substrate support blade or pedestal) within a loadlock. The probe is a fiber optic or metallic cable for carrying electromagnetic radiation (e.g., infrared laser light, ultraviolet laser light, visible laser light, millimeter waves, or X-rays) from a laser source or other emitter to the substrate. can include Additionally or alternatively, the probe may include one or more laser sources, a terahertz wave or millimeter wave transceiver antenna, and an x-ray emitter. The probe also includes one or more charge-coupled device (CCD) detectors, cadmium telluride mercury (MCT) detectors, indium gallium arsenide (InGaAs) detectors, mechanical probes with tips for tip-enhanced Raman scattering, Atomic force microscope probes, scanning tunneling microscope probes, X-ray detectors, and/or other types of instruments for measuring and/or inspecting substrates may be included. The loadlock 300 may also include one or more turbo vacuum ports for evacuating gases from the loadlock 300 (eg, process fluids that may enter the loadlock from the process chamber).

Both near-field and far-field inspection techniques are well suited to be performed within the loadlock 300 because the mechanical arm 302 allows the probe 304 to approach the substrate.

According to aspects of the present disclosure, the probe 304 can be housed (encapsulated) in a material (e.g., quartz) that has limited outgassing when exposed to vacuum, and the material of the probe (e.g., Contamination of the substrate from outgassing from the optical fiber strands) is prevented. Instruments that require close proximity or contact with the substrate (e.g., mechanical probe tips for tip-enhanced Raman scattering, atomic force microscopes, or scanning tunneling microscopes), when exposed to vacuum, It does not have to be housed in materials that have limited outgassing. Alternatively, instruments that require close proximity or contact with the substrate can be constructed of materials (eg, steel) that experience limited outgassing when exposed to vacuum.

FIG. 4 shows a schematic isometric view of a processing chamber 400 (eg, an ALD chamber) having multiple viewports 402 and 404, according to aspects of the present disclosure. The viewports may be made of quartz or other material that is semi-transparent to electromagnetic radiation 424 and 426 (eg, infrared, ultraviolet, visible, x-ray, and/or millimeter wave radiation). The first viewport 402 may be positioned to allow illumination of the substrate 406 with electromagnetic radiation to occur at a large grazing angle (ie, the angle measured from normal to the top surface of the substrate). A second viewport 404 may be positioned to allow the detector 430 to receive and/or detect electromagnetic radiation 432 scattered from the substrate at angles similar to the large grazing angle. Processing chamber 400 may be representative of processing chamber 100 shown in FIGS. 1A and 1B. The processing chamber may be connected to a processing fluid supply 472 via one or more processing fluid inlets 474 and may include a processing fluid outlet 478 connected to a vacuum pump 480 . A substrate 406 may be placed on a substrate support 410 (eg, substrate support blade or pedestal) within a loadlock. The substrate support 410 can be heated as desired for performance of the processing chamber.

One or more lasers (eg, infrared lasers, ultraviolet lasers, visible light lasers, or X-ray lasers) 420, 422 or other emitters of electromagnetic radiation beams 424, 426 illuminate substrate 406 through viewport 402. sell. As shown, the lasers are femtosecond-picosecond (fs-ps) pulsed visible lasers with wavelengths of 800 nanometers (nm) and fs-ps pulses with wavelengths in the range of 1-4 micrometers (μm). Although the disclosure is not so limited, other wavelength emitters may be used. A laser or other emitter can be attached to the load lock such that the electromagnetic radiation emitted by the emitter illuminates the substrate at a consistent angle. Mounting lasers and other emitters to one or more actuators (not shown) to cause the radiation to raster scan across the surface of the substrate in a controlled and reproducible manner during measurement and inspection of the substrate. ). One or more mirrors 442A and 442B, half-wave plates 444A and 444B, polarizers 446A and 446B, and lenses (eg, focusing lenses) 448A and 448B are actuators to cause the radiation to raster scan across the surface of the substrate. (not shown). Additionally or alternatively, the electromagnetic radiation from the emitter may be directed by a fiber optic cable or other conduit, the cable and/or conduit for causing the radiation to raster scan across the surface of the substrate. , is moved by an actuator.

Electromagnetic radiation 432 scattered (eg, reflected or refracted) from the substrate as a result of illuminating the substrate may exit processing chamber 400 via viewport 404 . One or more apertures 450, collimators 452, polarizers 454, mirrors 456, filters 458, and lenses 460 direct electromagnetic radiation 432 to one or more charge-coupled device (CCD) detectors 430, cadmium mercury telluride ( MCT) detectors, indium gallium arsenide (InGaAs) detectors, spectrometers, and other types of instruments for measuring and/or inspecting substrates. CCD detectors, MCT detectors, InGaAs detectors, spectrometers, and other instruments detect and/or measure electromagnetic radiation 432 exiting viewport 404 to determine measurements and other data about the substrate. It is possible. A detector or other instrumentation can be attached to the loadlock such that the electromagnetic radiation scattered from the substrate is measured or detected at consistent angles. The mounting of the detectors and other instruments is such that the detectors and other instruments detect radiation scattered from the substrate as the emitters are raster scanned across the substrate during measurement and inspection of the substrate. It can be moved to receive by one or more actuators (not shown). Additionally or alternatively, aperture 450, collimator 452, polarizer 454, mirror 456, filter 458, and lens 460 act as actuators to direct electromagnetic radiation 432 toward detectors and/or instruments. may be moved through

The substrate support 410 may be moved within the processing chamber as part of measuring and inspecting substrates. For example, the substrate support 410 may move the substrate within the processing chamber 400 such that one or more beams 424, 426 incident through the viewport 402 are scanned (eg, raster scanned) across the surface of the substrate. can move Additionally or alternatively, a scanning galvanometer mirror can be utilized to scan the beam from the emitter across the surface of the substrate. The galvo mirror may be located within the processing chamber 400 or may be external to the processing chamber 400 .

Although the embodiment shown in FIG. 4 shows the beam scanning over the top surface of substrate 406, the disclosure is not so limited. According to aspects of the present disclosure, the substrate support 410 may have cutouts or be semi-transparent to the beam (e.g., a prism), and the viewports 402 and 404 allow the beam to pass through the substrate. It may be arranged to allow scanning of the underside.

According to aspects of the present disclosure, second harmonic generation (SHG) and sum frequency generation (SFG) spectroscopy can be applied to ALD, CVD, PECVD, PVD, dielectric deposition, polymer layer deposition , and surfaces deposited via SRP. SFG spectroscopy probes the second-order molecular hyperpolarizability of materials and indicates which modes are active in non-centrosymmetric media. SFG and SHG are second-order nonlinear optical processes in which two incident photons, when spatially and temporally overlapped at a medium surface or interface, interact with each other and with the surface to It produces one photon with a frequency that is the sum of the frequencies of the two incident photons. When both incident photons come from the same source (and are therefore of the same frequency), the resulting process is called second harmonic generation (SHG). When both incident photons are of different frequencies, the resulting optical process is called sum frequency generation (SFG). These secondary optical processes are subject to conservation of photon energy and momentum. Conservation of photon momentum makes the process highly directional, so SFG or SHG photons can be spatially separated from incident photons, or other photons from other nonlinear optical processes. SFG and SHG are surface-sensitive processes because the second-order hyperpolarizability is only active in non-centrosymmetric media, e.g., at interfaces, surfaces, or even for molecules with no center of symmetry. (see, eg, Nature 337(6207), 519-525, 1989). For example, SFG spectroscopy studies atomic layer deposition of hydrogen (H ₂ ) on platinum by measuring the intensity of specific wavenumbers associated with the platinum-hydrogen bond, as described with reference to FIG. 5 below. can be used to monitor SFG spectroscopy is also utilized to monitor atomic layer deposition of aluminum oxide/silicon oxide ( _AlOx / _{SiOx )} on silicon substrates by measuring the intensity of specific wavenumbers associated with AlOx bonds. (eg, E. Kessels et al., Journal of Vacuum Science & Technology A35, 05C313 (2017), available at https://doi.org/10.1116.4993597).

FIG. 5 is a graph 500 showing curves showing monitoring of atomic layer deposition of hydrogen on platinum in an ALD process in which the platinum is exposed to different flow rates of hydrogen and sum frequency generation measurements of the surface of the platinum are made. . Curve 510 shows a set of SFG intensities (measured in s ⁻¹ ) for a set of wavenumbers (measured in cm ⁻¹ ) after exposure of platinum to hydrogen at the highest flow rate. After exposing platinum to hydrogen at the highest flow rate, SFG spectroscopy shows a relatively high intensity (ie, greater than 1.1) at a wavenumber of 2020 cm ⁻¹ , as shown at point 512 . After exposing platinum to hydrogen at a lower flow rate, SFG spectroscopy shows a lower intensity (ie, about 0.95) at a wavenumber of 2020 cm ⁻¹ , as indicated by point 514 . After each of the third, fourth, fifth, and sixth exposures of platinum to hydrogen at subsequently lower flow rates, SFG spectroscopy shows, as shown at points 516, 518, and 520, It shows an even lower intensity (ie less than 0.90) at a wavenumber of 2020 cm ⁻¹ . After exposing platinum to hydrogen at the lowest flow rate, SFG spectroscopy shows a lowest intensity (ie, 0.38) at a wavenumber of 2020 cm ⁻¹ , as indicated by point 522 .

According to aspects of the present disclosure, the technique of SFG spectroscopy is highly surface and interface specific, and therefore analysis of data from SFG spectroscopy typically involves subtracting the background signal from the measured signal. need not be subtracted.

FIG. 6 is a schematic diagram of an exemplary SFG spectroscopy system 600 configured to monitor a substrate 670 (eg, platinum) during ALD processing, according to aspects of the present disclosure (eg, ACS Catalysis, 2014, 4(6), pp. 1964-1971). In the exemplary ALD processing chamber 680, hydrogen flows into the chamber at location 682 and over the substrate, causing the hydrogen to dissociate and form a layer on the substrate. A mass spectrometer (MS) monitors the gas exiting the chamber to collect data on the amount of hydrogen deposited on the substrate. A heating rod 684 and piston 686 control the temperature and pressure within the ALD chamber. In an exemplary SFG spectroscopy system, a tunable laser system (ie, one or more electromagnetic radiation emitters) 602 is in the infrared range (ie, 1-9 microns, such as 4-7 microns or 5-6 microns). ) and laser light having a wavelength in the visible range (i.e., 520-900 nanometers, such as 600-900 nanometers, 750-850 nanometers, or 800 nanometers). a second pulse at 606; The first pulse of laser light then passes through various filters 608 that fine-tune the frequency of the first pulse to the desired frequency. The first pulse is then aimed by lens 610 and enters a first viewport 652 into the processing chamber. The second pulse is passed through filter 616 to fine tune the frequency of the second pulse. A lens 620 directs the second pulse through a first viewport 652 into the processing chamber. The first and second pulses may be aimed through prism 612 to illuminate substrate 670 . The first and second pulses interact to produce second harmonic pulse 630 as they irradiate the substrate. The second harmonic pulse can be aimed through prism 612 to exit the processing chamber through second viewport 654 . A lens 640 and a filter 642 can direct the second harmonic pulse and filter out reflections of the first and second pulses, thereby forming a photomultiplier tube 632 (PMT). but it is possible to collect the second harmonic pulse. The PMT provides information about the second harmonic pulse to boxcar integrator 634 . Finally, the boxcar integrator provides the signal to computer 636 for interpretation.

According to aspects of the present disclosure, first viewport 652 and second viewport 654 may be formed from magnesium fluoride ( _MgF2 ) or calcium fluoride ( _CaF2 ). This is because these materials allow transmission of both a first pulse with wavelengths in the infrared range and a second pulse with wavelengths in the visible range.

FIG. 7 is a schematic diagram of an exemplary substrate handling blade 700 in accordance with aspects of the present disclosure. An exemplary substrate handling blade may include substrate support blade 702 and instrument support arm portion 704 . The instrument support arm supports a laser source 706 (eg, one or more electromagnetic radiation emitters, lasers, or other sources of laser light such as fiber optic cables carrying laser light from a remote laser) and a spectrometer 708. I can. As shown in FIG. 6, a laser source may emit two pulses of laser light 710, 712 having different wavelengths. As shown in FIG. 6, the laser source may include one or more mirrors, filters, etalons, and lenses to direct pulses of laser light onto the substrate on the substrate handling blade. The spectrometer also includes one or more apertures, filters, to block both the first and second pulse reflections 720 and 722 and to direct the second harmonic pulse 724 to a detector within the spectrometer. , lenses, and polarizers.

According to aspects of the present disclosure, instrument support arm portion 704 and substrate handling blade 702 may move together into a processing chamber (eg, processing chamber 100 shown in FIG. 1). Additionally or alternatively, the instrument support arm portion may move (eg, rotate away from) independently of the substrate handling blade as the substrate handling blade enters the processing chamber.

In aspects of the present disclosure, instruments on the instrument support arm portion 704, such as the laser source 706 and/or the spectrometer 708, operate on the substrate while the substrate handling blade is in the transfer chamber (eg, the transfer chamber 206 shown in FIG. 2). A substrate supported by a handling blade can be monitored, allowing monitoring and/or inspection of the substrate without having to break vacuum within the processing system.

According to aspects of the present disclosure, the spectrometer may be a complementary metal-oxide-semiconductor (CMOS) spectrometer or a photonic crystal fiber (PCF) based spectrometer. .

The above non-limiting examples are provided to provide a better understanding of the foregoing discussion. The examples may be directed to specific embodiments, but the examples should not be construed as limiting the disclosure in any particular respect.

While the above description 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 of the present disclosure. The scope of the disclosure is determined by the following claims.

Claims (15)

a processing chamber body having a first viewport and a second viewport;
a substrate support within the processing chamber body;
an electromagnetic radiation emitter operable to illuminate the substrate on the substrate support through the first viewport;
and a detector operable to detect electromagnetic radiation scattered from the substrate through the second viewport. 2. The apparatus of claim 1, wherein the substrate support is operable to move the substrate such that the beam from the electromagnetic radiation emitter is scanned over the surface of the substrate. 2. The apparatus of claim 1, further comprising a galvanomirror operable to direct a beam from said electromagnetic radiation emitter onto the surface of said substrate. The electromagnetic radiation emitter produces a first laser source operable to produce a first pulse of laser light having a first wavelength and a second pulse of laser light having a second wavelength. 2. The apparatus of claim 1, comprising a second laser source operable to. 5. The device of claim 4, wherein the first wavelength is between 1 micrometer and 4 micrometers and the second wavelength is between 750 nanometers and 850 nanometers. The detector is operable to measure the intensity of a sum frequency generation (SFG) pulse caused by interaction between the first pulse, the second pulse and the substrate. 5. The apparatus of claim 4. A system for processing a substrate, comprising:
a processing chamber having a first slit valve opening configured to allow passage of the substrate and a second slit valve opening configured to allow passage of the substrate;
a first slit valve operable to open and close the first slit valve opening of the processing chamber, the first slit valve operable to form a first hermetic seal when closed;
a second slit valve operable to open and close the second slit valve opening of the processing chamber, the second slit valve operable to form a second hermetic seal when closed;
a loadlock having a transfer slit valve opening aligned with the second slit valve opening of the processing chamber, a loadlock port, and a substrate support;
a mechanical arm having an encased probe;
the mechanical arm is operable to access an interior of the loadlock through the loadlock port;
the mechanical arm is operable to move a gauge within the housed probe to approach the substrate on the substrate support;
the contained probe having an emitter operable to emit electromagnetic radiation to illuminate the substrate;
A system for processing a substrate, wherein the contained probe has a detector operable to detect electromagnetic radiation scattered from the substrate. further comprising a substrate handling robot having a substrate handling blade;
the mechanical arm unit is connected to the substrate handling robot;
8. The system of claim 7, wherein the mechanical arm is operable to move the instrument within the housed probe into proximity with the substrate on the substrate handling blade. The emitter comprises a first laser source operable to produce a first pulse of laser light having a first wavelength and operable to produce a second pulse of laser light having a second wavelength. 8. The system of claim 7, comprising a possible second laser source. 10. The system of claim 9, wherein the first wavelength is between 1 micrometer and 4 micrometers and the second wavelength is between 750 nanometers and 850 nanometers. The detector measures the intensity of sum frequency generation (SFG) pulses caused by interactions between the first pulse, the second pulse, and the substrate on the substrate support. 10. The system of claim 9, operable to: An apparatus for measuring a substrate in a processing system comprising:
a mechanical arm operable to access the interior of the processing system loadlock;
a probe housed on the mechanical arm;
an emitter within the housed probe, the emitter operable to emit electromagnetic radiation to illuminate the substrate;
a detector in the housed probe operable to detect electromagnetic radiation scattered from the substrate;
An apparatus for measuring a substrate within a processing system, wherein the mechanical arm is operable to move at least one of the emitter or the detector closer to the substrate. The emitter comprises a first laser source operable to produce a first pulse of laser light having a first wavelength and operable to produce a second pulse of laser light having a second wavelength. 13. The apparatus of claim 12, comprising a possible second laser source. 14. The device of claim 13, wherein the first wavelength is between 1 micrometer and 4 micrometers and the second wavelength is between 750 nanometers and 850 nanometers. The detector is operable to measure the intensity of a sum frequency generation (SFG) pulse caused by interaction between the first pulse, the second pulse and the substrate. 14. The device according to claim 13.

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