Detection and localization of anomalous plasma events in fabrication chambers

Abstract

An apparatus for determining the occurrence of an abnormal plasma event at or near a processing station in a multi-station integrated circuit fabrication chamber is disclosed. In certain embodiments, light emissions generated in response to the abnormal plasma event can be detected by at least one of a plurality of photosensors. A processor can cooperate with the plurality of photosensors to determine that the abnormal plasma event has occurred at or near a particular processing station in the multi-station integrated circuit fabrication chamber.

Description

[0001] Incorporated by Reference

[0002] The PCT application form is filed concurrently with this specification as a part of this application. Each application identified in the concurrently filed PCT application form from which this application claims the benefit or priority is incorporated herein by reference in its entirety and for all purposes. Background Art

[0003] During wafer fabrication, for example, during the deposition or etching of films on substrates using multi-station integrated circuit fabrication chambers, anomalous plasma events can occur. Such events can cause damage to the wafers and / or the IC fabrication chamber itself. Therefore, methods for detecting and locating anomalous plasma events within IC fabrication chambers remain an active area of ​​research.

[0004] The background description provided here is for the purpose of generally presenting the context of the present disclosure. No admission is made, either explicitly or implicitly, that the work of the presently designated inventors is prior art to the present disclosure to the extent that it is described in this background section and in aspects of the specification that were not determined to be prior art at the time the application was filed. Summary of the Invention

[0005] Briefly, certain embodiments may be directed to a fabrication chamber comprising a plurality of stations. The fabrication chamber further comprises: a plurality of viewing ports at least partially transparent to light emissions emitted from at least one of the plurality of stations. The fabrication chamber further comprises: a plurality of photosensors, each of the plurality of photosensors disposed proximate a corresponding one of the plurality of viewing ports to detect light emissions emitted from the at least one of the plurality of stations. The fabrication chamber further comprises: a processor configured to identify at least one of the plurality of stations at which an abnormal plasma event has occurred based at least in part on output signals from at least two of the plurality of photosensors.

[0006] In certain embodiments, the viewing ports of the fabrication chamber are arranged in adjacent sidewalls of the fabrication chamber to transmit the light emissions from each of the plurality of stations. In certain embodiments, the fabrication chamber includes four stations. One or more of the plurality of viewing ports enables observation of two or more adjacent stations, but not all of the stations. In certain embodiments, the processor identifies the at least one station in the plurality of stations where the anomalous plasma event has occurred, responsive to evaluating the output signals from the plurality of photosensors. A first viewing port in the plurality of viewing ports enables observation of a first and a second station in the plurality of stations, and a second viewing port in the plurality of viewing ports enables observation of a third and a fourth station in the plurality of stations. A third viewing port in the plurality of viewing ports enables observation of the first and the third stations in the plurality of stations, and a fourth viewing port in the plurality of viewing ports enables observation of the second and the fourth stations in the plurality of stations. In certain embodiments, the viewing ports of the fabrication chamber are at least partially transparent to light emissions having a wavelength between approximately 300 nm and approximately 700 nm. In some embodiments, the processor is configured to identify the at least one station where the abnormal plasma event has occurred based at least in part on the abnormal plasma event occurring within a duration between about 1 μs and about 100 ms. In some embodiments, the abnormal plasma event comprises a transient generation of an electrical discharge between two or more localized regions within one of the plurality of stations. In some embodiments, the processor is configured to identify the at least one station where the abnormal plasma event has occurred based at least in part on the light emission reaching a threshold amplitude in less than about 100 ms. In some embodiments, the processor generates a signal indicating that a semiconductor wafer at the at least one of the plurality of stations is proximate to a location where the abnormal plasma event has occurred. In some embodiments, the fabrication chamber is configured to perform a plasma-based etching process or a plasma-based deposition process.

[0007] In certain embodiments, an apparatus for detecting and reporting an abnormal plasma event may include first and second photosensors. Each of the first and second photosensors is disposed at a respective viewing port of a multi-station integrated circuit fabrication chamber. Each of the first and second photosensors is configured to detect an optical signal having a minimum threshold amplitude within approximately 1 μs and approximately 100 ms. The apparatus further includes a processor configured to identify a station of the multi-station integrated circuit fabrication chamber that has experienced an abnormal plasma event based, at least in part, on an output signal level of each of the first and second photosensors.

[0008] In certain embodiments, a method includes receiving output signals from a plurality of photosensors, at least one of the plurality of photosensors having a field of view of two or more stations of a multi-station integrated circuit fabrication chamber. The method further includes filtering the received output signals to select output signals having amplitudes less than a threshold. The method further includes comparing logic states corresponding to the filtered received output signals to identify the station in the multi-station integrated circuit fabrication chamber where an abnormal plasma event has occurred.

[0009] In certain embodiments, the method includes using a photosensor, wherein the field of view of a first photosensor in the plurality of photosensors overlaps the field of view of at least a second photosensor in the plurality of photosensors. In certain embodiments, the method further includes filtering the output signal to filter out signals having a duration less than a threshold value. In certain embodiments, the method further includes filtering out signals having a duration less than about 1 μs. In certain embodiments, the method further includes filtering the output signal to filter out signals having a duration exceeding a threshold value. In certain embodiments, the method includes filtering, wherein the filtering includes filtering out signals having a duration greater than about 100 ms. In certain embodiments, the method further includes indicating that a measurement process is to be performed on the semiconductor wafer in response to detecting the abnormal plasma event near the semiconductor wafer.

[0010] In certain embodiments, an integrated circuit fabrication chamber includes: a plurality of integrated circuit fabrication stations. The integrated circuit fabrication chamber further includes: one or more input ports for coupling a radio frequency (RF) signal to at least one of the plurality of integrated circuit fabrication stations. The integrated circuit fabrication chamber further includes: a plurality of viewing ports that are at least partially transparent to light emissions emitted from at least one of the plurality of integrated circuit fabrication stations. The integrated circuit fabrication chamber further includes: at least first and second photosensors. Each of the at least first and second photosensors is disposed proximate a corresponding one of the plurality of viewing ports to detect light emissions emitted from the at least one of the plurality of integrated circuit fabrication stations.

[0011] In certain embodiments, the plurality of observation ports of the integrated circuit fabrication chamber are at least partially transparent to light emissions having a wavelength of about 300 nm to about 700 nm. In certain embodiments, the light emissions generated at a station of the integrated circuit fabrication chamber are generated in response to the RF signal coupled to at least one of the plurality of integrated circuit fabrication stations. In certain embodiments, the plurality of integrated circuit fabrication stations comprises four stations. In certain embodiments, the at least first and second photosensors provide an output signal having a duration of at least 1 μs in response to detecting the light emissions. In certain embodiments, the at least first and second photosensors provide an output signal to a processor to identify a station of the plurality of integrated circuit fabrication stations at which an anomalous plasma event has occurred. In certain embodiments, the processor identifies the station of the plurality of integrated circuit fabrication stations based at least in part on the output signals from the first and second photosensors of the at least first and second photosensors. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Various implementations disclosed herein are illustrated by way of example and not limitation in the figures of the accompanying drawings in which like reference numerals refer to similar elements.

[0013] Figure 1A Exemplary apparatus for depositing or etching films on or over a substrate using any number of processes according to various embodiments are shown.

[0014] Figure 1B is a schematic diagram of an exemplary multi-station integrated circuit fabrication chamber according to various embodiments.

[0015] Figure 2A is a schematic diagram of an exemplary abnormal plasma event detection and localization system implemented on a multi-station integrated circuit fabrication chamber according to an embodiment.

[0016] Figure 2B An exemplary photosensor having a field of view suitable for detecting anomalous plasma events occurring within a multi-station integrated circuit fabrication chamber is shown in accordance with an embodiment.

[0017] Figure 2C is an exemplary truth table showing logic states corresponding to output signals of a photosensor implemented in an abnormal plasma event detection and location system for a multi-station integrated circuit fabrication chamber, according to an embodiment.

[0018] Figure 2D is an example output signal trace from a photosensor indicating an abnormal plasma event in a multi-station integrated circuit fabrication chamber, according to one embodiment.

[0019] Figure 3is a schematic diagram of an example of an abnormal plasma event detection and localization system implemented on a multi-station integrated circuit fabrication chamber according to another embodiment.

[0020] Figure 4A is a schematic diagram of an example of an abnormal plasma event detection and localization system implemented on a multi-station integrated circuit fabrication chamber according to another embodiment.

[0021] Figure 4B is an example according to another embodiment, which shows the corresponding Figure 4A Logic states of output signals of photosensors implemented in an exemplary abnormal plasma event detection and localization system.

[0022] Figure 5 is a flow chart of an exemplary method for detecting and localizing abnormal plasma events performed on a multi-station integrated circuit fabrication chamber, according to various embodiments. DETAILED DESCRIPTION

[0023] In certain types of integrated circuit fabrication chambers, a radio frequency (RF) power supply may be used to provide a signal that causes a plasma to form within the chamber. The plasma may comprise ionized gaseous compounds. In multi-station integrated circuit fabrication chambers, the RF power supply may be used to provide a signal that generates a plasma at a station within the multi-station integrated circuit fabrication chamber. After ionization, the gaseous compounds within the chamber may react with each other, for example, during an integrated circuit deposition process or an integrated circuit etching process. In a multi-station integrated circuit fabrication chamber where multiple semiconductor wafers undergo deposition or etching processes simultaneously, a single RF input signal may provide RF power to each station within the multi-station chamber. In some cases, the signal amplitude from the RF power supply may be controlled. The RF signal amplitude may be controlled to provide sufficient energy to form a plasma within the chamber without causing abnormal conditions within the chamber. Abnormal conditions may include, for example, arcing or other visible events resulting from discharges between or within two or more localized areas within a processing station. Abnormal conditions may result in overheating and overcurrent. Abnormal conditions may include instabilities in the plasma due to particles present in the chamber, sudden changes in gas pressure and / or gas composition, and malfunctions in the RF power generation circuitry.

[0024] In certain circumstances, in response to an abnormal plasma event, such as the formation of an arc, in a multi-station integrated circuit fabrication chamber, localized areas of one or more integrated circuit wafers being fabricated may be exposed to elevated temperatures. The abnormal plasma event may expose the integrated circuit wafer being fabricated to an electrical current sufficient to damage the circuit wafer. In such circumstances, it may be necessary to remove the potentially damaged integrated circuit wafer from the fabrication chamber so that the wafer can undergo metrology processing. The metrology processing may include performing electrical measurements, physical inspections, and / or other processing. In certain circumstances, the formation of an arc may cause severe damage, which may result in the scrapping or discarding of one or more potentially damaged integrated circuit wafers. Furthermore, in certain circumstances, the formation of an arc may cause damage to the integrated circuit fabrication chamber itself, which may require expensive repairs and the temporary deactivation of the fabrication chamber.

[0025] For the reasons described above, and possibly other reasons, it may be advantageous to quickly detect that an abnormal plasma event has occurred within a multi-station integrated circuit fabrication chamber. An abnormal plasma event (e.g., the formation of an arc) may expose the integrated circuit wafers and / or internal portions of the multi-station integrated circuit fabrication chamber to elevated temperatures and increased currents. However, in response to timely detection of an abnormal plasma event within the fabrication chamber, a power source, such as an RF power source, may be interrupted, reduced in amplitude, or adjusted in some other manner. Interruption, reduction in amplitude, or other types of adjustments to the RF power source may minimize, or in some cases, completely avoid, damage to the integrated circuit wafers and / or the integrated circuit fabrication chamber itself. Furthermore, by detecting the location (or station) where the abnormal plasma event has occurred, a separate metrology process may be performed on a single wafer. Performing a metrology process on a single wafer may be advantageous compared to performing a metrology process on all wafers present within the multi-station fabrication chamber. Detecting and locating abnormal plasma events within an integrated circuit fabrication chamber may be advantageous for other reasons, and the claimed subject matter is not limited in this respect.

[0026] Certain embodiments and implementations can be used in conjunction with several wafer fabrication processes, such as various plasma enhanced atomic layer deposition (PEALD) processes (e.g., PEALD1, PEALD2), various plasma enhanced chemical vapor deposition (e.g., PECVD1, PECVD2, PECVD3) processes, or can be used in real time during a single deposition process. In certain embodiments, an RF power generator having multiple output ports can be used at any signal frequency, such as frequencies between 300 kHz and 60 MHz, which may include frequencies of 400 kHz, 1 MHz, 2 MHz, 13.56 MHz, and 27.12 MHz. However, in other embodiments, an RF power generator having multiple output ports can operate at any signal frequency, which may include relatively low frequencies, such as between 50 kHz and 300 kHz, as well as higher frequencies, such as frequencies between about 60 MHz and about 100 MHz, with little limitation.

[0027] It should be noted that although the specific embodiments described herein may show and / or describe a multi-station semiconductor fabrication chamber comprising four processing stations, the claimed subject matter is intended to encompass a multi-station integrated circuit fabrication chamber comprising any number of processing stations. Thus, in certain implementations, the output signal of the RF power generator may be distributed between two or three processing stations of the multi-station integrated circuit fabrication chamber. The output power signal from the RF power generator may be distributed between a larger number of processing stations (e.g., five processing stations, six processing stations, eight processing stations, ten processing stations) with little or no limitation. The output power signal from the RF power generator may be distributed between any other number of processing stations of the multi-station integrated circuit fabrication chamber. The specific embodiments described herein may show and / or describe a single relatively low frequency RF signal (e.g., a frequency between about 300 kHz and about 2 MHz) and a single relatively high frequency RF signal (e.g., a frequency between 2 MHz and 100 MHz). The claimed subject matter is intended to encompass the use of any number of radio frequencies, such as frequencies below 2 MHz, as well as any number of radio frequencies above 2 MHz.

[0028] The manufacture of semiconductor devices can involve depositing and etching one or more thin films on or above a planar or non-planar substrate in an integrated manufacturing process. In certain aspects of integrated circuit manufacturing processes, it may be useful to deposit thin films that conform to unique substrate topography. A type of reaction that is useful in many instances may involve chemical vapor deposition (CVD). In certain CVD processes, gaseous reactants introduced into a reaction chamber undergo a gas phase reaction simultaneously. The products of the gas phase reaction are deposited on the substrate surface. This type of reaction can be driven or enhanced by the presence of a plasma, in which case the process may be referred to as a plasma enhanced chemical vapor deposition (PECVD) reaction. As used herein, unless otherwise indicated, the term CVD is intended to include PECVD. CVD processes have certain disadvantages that make them less suitable in certain circumstances. For example, mass transport limitations of CVD gas phase reactions may result in a deposition effect that presents a thicker deposition at the top surface (e.g., the top surface of the gate stack) and a thinner deposition at the recessed surface (e.g., the bottom corner of the gate stack). In addition, in response to certain semiconductor dies with regions having different device densities, mass transport effects across the substrate surface may result in thickness variations within the die and within the wafer. Therefore, during subsequent etch processing, thickness variations can lead to over-etching in some areas and under-etching in other areas, which can degrade device performance and die yield. Another difficulty associated with CVD processing is that such processes are generally unable to deposit conformal films in features with high aspect ratios. This problem is likely to become increasingly severe as device dimensions continue to shrink. Figure 1A and Figure 1B These and other shortcomings of specific aspects of the wafer fabrication process are discussed.

[0029] In another example, some deposition processes involve multiple film deposition cycles, each cycle producing a discrete film thickness. For example, in atomic layer deposition (ALD), the thickness of the deposited layer may be limited by the amount of one or more film precursor reactants that can be adsorbed on the substrate surface to form an adsorption-limited layer prior to the film-forming chemical reaction itself. Therefore, the characteristic of ALD involves the formation of thin film layers (such as layers with a width of a single atom or molecule), which are used in a repetitive and sequential manner. As device and feature sizes continue to decrease in scale, and as three-dimensional devices and structures become increasingly prevalent in integrated circuit (IC) design, the ability to deposit thin conformal films (e.g., films of material having a uniform thickness relative to the shape of the underlying structure) continues to increase in importance. Therefore, given that ALD is a film-forming technology in which each deposition cycle operates to deposit a single atomic or molecular layer of material, ALD can be quite suitable for the deposition of conformal films. In some instances, a device manufacturing process involving ALD can include multiple ALD cycles, which can number in the hundreds or thousands, and can then be used to form films of virtually any desired thickness. Moreover, with each layer being thin and conformal, the film produced by such a process can conform to the shape of any underlying device structure. In certain embodiments, an ALD cycle may include the following steps:

[0030] The substrate surface is exposed to a first precursor.

[0031] Purge the reaction chamber where the substrate is located.

[0032] Activation of the reaction at the substrate surface, for example using a plasma and / or a second precursor.

[0033] Purge the reaction chamber where the substrate is located.

[0034] At least in certain embodiments, the duration of each ALD cycle can be less than about 25 seconds, or less than about 10 seconds, or less than about 5 seconds. One or more plasma exposure steps of an ALD cycle can have a short duration, such as about 1 second or less.

[0035] Turning now to the accompanying drawings, Figure 1A Exemplary apparatus for depositing or etching films on or over a substrate using any number of processes are shown according to various embodiments. Figure 1A The processing apparatus 100 depicts a single processing station 102 of a process chamber having a single substrate holder 108 (e.g., a pedestal) within an interior volume that may be maintained under vacuum by a vacuum pump 118. A showerhead 106 and a gas delivery system 130 (which may be fluidly coupled to the process chamber) may allow for delivery of, for example, film precursors, as well as carrier and / or sweep and / or process gases, secondary reactants, and the like. Figure 1A Also shown are the devices used for plasma generation within the processing chamber. Figure 1A The apparatus schematically depicted in FIG. 1 may be particularly suitable for performing plasma enhanced CVD.

[0036] exist Figure 1A In the embodiment of the present invention, the gas delivery system 130 includes a mixing vessel 104 for mixing and / or conditioning process gases for delivery to the showerhead 106. One or more mixing vessel inlet valves 120 can control the introduction of process gases into the mixing vessel 104. Certain reactants can be stored in liquid form before being vaporized and subsequently delivered to the process station 102 of the process chamber. Figure 1A Embodiments include a vaporization point 103 for vaporizing liquid reactants to be supplied to a mixing vessel 104. In some implementations, the vaporization point 103 can include a heated liquid injection module. In some other implementations, the vaporization point 103 can include a heated vaporizer. In still other implementations, the vaporization point 103 can be eliminated from the processing station. In some implementations, a liquid flow controller (LFC) upstream of the vaporization point 103 can be provided for controlling the mass flow of the liquid for vaporization and delivery to the processing station 102.

[0037] The showerhead 106 is operable to distribute process gases and / or reactants (e.g., film precursors) toward the substrate 112 at the processing station, the flow of which may be controlled by one or more valves (e.g., valves 120, 120A, 105) upstream of the showerhead. Figure 1A In the illustrated embodiment, the substrate 112 is depicted as being positioned below the showerhead 106 and is shown as being placed on a pedestal 108. The showerhead 106 can be of any suitable shape and can include any suitable number and arrangement of ports for distributing process gases to the substrate 112. In some embodiments having two or more stations, the gas delivery system 130 includes a valve or other flow control structure upstream of the showerhead that can independently control the flow of process gases and / or reactants to each station so that gas flow can flow to one station while simultaneously inhibiting gas flow to a second station. In addition, the gas delivery system 130 can be configured to independently control the process gases and / or reactants delivered to each station in a multi-station apparatus so that the gas composition provided to different stations is different; for example, the partial pressures of gas components can vary between multiple stations at the same time.

[0038] exist Figure 1A, volume 107 is depicted as being located below showerhead 106. In some implementations, pedestal 108 can be raised or lowered to expose substrate 112 to volume 107 and / or to change the size of volume 107. Optionally, pedestal 108 can be lowered and / or raised during portions of the deposition process to adjust process pressure, reactant concentrations, and / or the like within volume 107. Showerhead 106 and pedestal 108 are depicted as being electrically coupled to RF power generator 114 and matching network 116 to power the plasma generator. Thus, showerhead 106 can serve as an electrode for coupling RF power into process station 102. In some implementations, plasma energy is controlled (e.g., via a system controller having appropriate machine-readable instructions and / or control logic) by controlling one or more of process station pressure, gas concentrations, RF power generators, and / or the like. For example, the RF power generator 114 and the matching network 116 can be operated at any suitable RF power level operable to form a plasma having a desired radical species composition. In addition, the RF power generator 114 can provide RF power having more than one frequency component, such as a low frequency component (e.g., less than 2 MHz) and a high frequency component (e.g., greater than 2 MHz).

[0039] In some implementations, plasma generation and maintenance conditions are controlled by appropriate hardware and / or appropriate machine-readable instructions in a system controller. The machine-readable instructions may include a series of input / output control (IOC) instructions. In one example, instructions for generating or maintaining a plasma are provided in the form of a plasma activation recipe of a process recipe. In some cases, the process recipes may be arranged sequentially so that at least some of the process instructions can be executed simultaneously. In some implementations, instructions for setting one or more plasma parameters may be included in a recipe prior to the plasma generation process. For example, a first recipe may include instructions for setting the flow rate of an inert gas (e.g., helium) and / or a reactive gas, instructions for setting a plasma generator to a power set point, and a time delay instruction for the first recipe. A second subsequent recipe may include instructions for enabling the plasma generator and a time delay instruction for a second recipe. A third recipe may include instructions for disabling the plasma generator and a time delay instruction for the third recipe. It should be understood that within the scope of the present disclosure, these recipes may be further subdivided and / or repeated in any suitable manner. In some deposition processes, the duration of the plasma ignition may correspond to a duration of several seconds, such as from about 3 seconds to about 15 seconds, or may involve a longer duration, such as up to about 30 seconds. In certain implementations described herein, a much shorter plasma ignition may be applied during a process cycle. Such plasma ignition duration may be on the order of less than about 50 milliseconds, with about 25 milliseconds being utilized in a particular example.

[0040] For simplicity, in Figure 1A The processing apparatus 100 is depicted as a standalone station (102) for maintaining a processing chamber in a low pressure environment. However, it will be appreciated that, according to various embodiments, multiple processing stations may be included in a multi-station processing tool environment, such as Figure 1B 1, which depicts a schematic diagram of an exemplary multi-station processing tool. The processing tool 101 employs an integrated circuit fabrication chamber 165 that includes a plurality of fabrication processing stations, each of which can be used to process a wafer held by a wafer holder (e.g., Figure 1A The processing operation is performed on the substrate held by the susceptor 108). Figure 1B In the embodiment of FIG, integrated circuit fabrication chamber 165 is shown as including four processing stations 151, 152, 153, and 154. Other similar multi-station processing apparatuses may include more or fewer processing stations, depending on the implementation and, for example, the desired degree of parallel wafer processing, size / space constraints, cost constraints, etc. Figure 1B Also shown is a substrate handling robot 175, which can operate under the control of the system controller 190 and is configured to receive wafers from a wafer cassette (in Figure 1B The substrate from the wafer box can be moved from the load port 180 and enter the multi-station integrated circuit fabrication chamber 165 and arrive at one of the processing stations 151, 152, 153 and 154.

[0041] Figure 1B Also depicted is an embodiment of a system controller 190 for controlling the processing conditions and hardware states of the processing tool 101. The system controller 190 may include one or more memory devices, one or more mass storage devices, and one or more processors. The one or more processors may include a central processing unit, analog and / or digital input / output connections, a stepper motor controller board, and the like. In some implementations, the system controller 190 controls all activities of the processing tool 101. The system controller 190 executes system control software stored in a mass storage device, which may be loaded into a memory device and executed by the processor of the system controller. The software executed by the processor of the system controller 190 may include instructions for controlling timing, gas mixtures, chamber and / or station pressures, chamber and / or station temperatures, wafer temperatures, substrate pedestals, chuck and / or susceptor positions, the number of cycles performed on one or more substrates, and other parameters of the specific process performed by the processing tool 101. These programmed processes can include various types of processes, including, but not limited to, processes related to determining the amount of buildup on surfaces within the chamber, processes involving multiple cycles related to film deposition on a substrate, determining and obtaining multiple compensation cycles, and processes related to the clean chamber. The system control software, which can be executed by one or more processors of the system controller 190, can be configured in any suitable manner. For example, various process tool component subroutines or control objects can be written to control the operation of the process tool components required to perform various tool processes.

[0042] In some embodiments, the software for execution by the processor of the system controller 190 may include input / output control (IOC) sequence instructions for controlling the various parameters described above. For example, each phase of the deposition cycle of a substrate may include one or more instructions executed by the system controller 190. Instructions for setting the process conditions for an ALD conformal film deposition process phase may be included in a corresponding ALD conformal film deposition recipe phase. In some implementations, the recipe phases may be arranged sequentially so that all instructions for a process phase are executed concurrently with that process phase.

[0043] In some embodiments, other computer software and / or programs stored on a mass storage device of the system controller 190 and / or a memory device accessible to the system controller 190 may be employed. Examples of programs or program segments for this purpose include substrate positioning programs, process gas control programs, pressure control programs, heater control programs, and plasma control programs. The substrate positioning program may include program code for a process tool component that is used to load a substrate onto the pedestal 108 ( Figure 1A and controls the spacing between the substrate and other components of the processing tool 101. The positioning program may include instructions for appropriately moving the substrate into and out of the reaction chamber as needed to deposit films on the substrate and to clean the chamber.

[0044] The process gas control program may include code for controlling gas composition and flow rate and for controlling the flow of gas into one or more processing stations before deposition, thereby stabilizing the pressure in the processing station. In some embodiments, the process gas control program includes instructions for introducing gas during film formation on a substrate in a reaction chamber. This may include introducing gas for one or more substrates in a batch of substrates for different numbers of cycles. The pressure control program may include program code for controlling the pressure in the processing station by adjusting, for example, a throttle valve in an exhaust system of the processing station, a gas flow rate into the processing station, and the like. The pressure control program may include instructions for maintaining the same pressure during deposition of different numbers of cycles on one or more substrates during batch processing.

[0045] The heater control program may include program code for controlling the current flowing to the heating unit 110 for heating the substrate. Alternatively, the heater control program may control the delivery of a heat transfer gas (eg, helium) to the substrate.

[0046] In some embodiments, there may be a user interface associated with the system controller 190. The user interface may include a display screen, graphical software displays of processing tools and / or processing conditions, and user input devices such as a pointing device, keyboard, touch screen, microphone, and the like.

[0047] In some embodiments, the parameters adjusted by the system controller 190 may relate to process conditions. Non-limiting examples may include process gas composition and flow rate, temperature, pressure, plasma conditions, and the like. These parameters may be provided to the user in the form of a recipe, which may be input using a user interface. The recipe for an entire batch of substrates may include a compensation cycle count for one or more substrates within the batch to account for thickness trends during processing of the batch.

[0048] The signal for monitoring the manufacturing process can be provided by analog and / or digital input connection of the system controller 190 from various processing tool sensors. The signal for controlling the process can be transmitted by analog and / or digital input connection of the processing tool 101. Non-limiting examples of processing tool sensors that can be monitored include mass flow controllers, pressure sensors (such as manometers), thermocouples, etc. Sensors can also be included that are used to monitor and determine the thickness of the material layer on the accumulation on one or more surfaces inside the chamber and / or the substrate inside the chamber. Feedback and control algorithms through appropriate programming can be used together with the data from these sensors to maintain processing conditions.

[0049] The system controller 190 may provide program instructions for implementing the above-described deposition process. The program instructions may control various process parameters, such as DC power level, pressure, temperature, number of cycles to the substrate, amount of buildup on at least one surface within the chamber, etc. The instructions may control the parameters to operate the in-situ deposition of the film stack according to the various embodiments described herein.

[0050] For example, the system controller may include control logic for performing the techniques described herein, such as (a) determining the amount of accumulated deposition material currently on at least one interior region within a deposition chamber. Furthermore, the system controller may include control logic for applying the amount of accumulated deposition material determined in (a), or a parameter derived therefrom, to a relationship between (i) the number of ALD cycles required to achieve a target deposition thickness and (ii) a variable representing the amount of accumulated deposition material to obtain a compensated number of ALD cycles required to produce the target deposition thickness given the amount of deposition material currently accumulated on the interior region within the deposition chamber. The system controller may include control logic for performing the compensated number of ALD cycles on one or more substrates in the batch of substrates. The system may also include control logic for determining that the accumulation in the chamber has reached an accumulation limit and, in response to this determination, stopping processing of the batch of substrates, and initiating a cleaning operation within the chamber.

[0051] In addition to Figure 1BIn addition to the aforementioned functions and / or operations performed by the system controller 190, the system controller may additionally control and / or manage the operation of an RF power generator 195 that may deliver RF power to the multi-station integrated circuit fabrication chamber 165 via the RF power input port 167. As further described herein, such operations may involve: determining upper and lower thresholds for RF power to be delivered to the integrated circuit fabrication chamber 165; RF power activation / deactivation times, RF power on / off durations, duty cycles, operating frequencies, and the like. Additionally, the system controller 190 may determine a set of normal operating parameters for the RF power to be delivered to the integrated circuit fabrication chamber 165 via the RF power input port 167. These parameters may include: 11 ”) for example, upper and lower thresholds for power reflected from the RF power input port 167, and voltage standing wave ratio. These parameters may also include upper and lower thresholds for voltage applied to the RF power input port 167; upper and lower thresholds for current conducted through the RF power input port 167, and an upper threshold for the magnitude of the phase angle between the voltage and current conducted through the RF power input port 167. These thresholds may be used to define an “out-of-range” RF signal characteristic. For example, a reflected power greater than an upper threshold may indicate an out-of-range RF power parameter. Likewise, an applied voltage or conducted current having a value below a lower threshold or greater than an upper threshold may indicate an out-of-range RF signal characteristic. Similarly, a phase angle between the applied voltage and the conducted current greater than an upper threshold may indicate an out-of-range RF power parameter.

[0052] In certain implementations, the RF power generator 195 can be operated to generate two frequencies, such as a first frequency of approximately 400 kHz and a second frequency, such as a frequency of approximately 27.12 MHz. However, it should be noted that the RF power generator may be capable of generating other frequencies, such as frequencies between approximately 300 kHz and approximately 100 MHz, and the claimed subject matter is not limited in this respect. In certain embodiments, the signal generated by the RF power generator 195 can include at least one low frequency (LF) and at least one high frequency (HF), wherein the low frequency (LF) can be defined as a frequency between approximately 300 kHz and approximately 2 MHz, and the high frequency (HF) can be defined as a frequency greater than approximately 2 MHz but less than approximately 100 MHz.

[0053] In certain embodiments, the multi-station integrated circuit fabrication chamber 165 may also include input ports ( Figure 1B(additional input ports not shown in the figure). In certain embodiments, a processing station of integrated circuit fabrication chamber 165 can utilize first and second input ports, wherein the first input port can transmit a signal having a first frequency, and wherein the second input port can transmit a signal having a second frequency. The use of two or more frequencies can result in improved plasma characteristics, which can lead to a deposition rate or etch rate within certain limits and / or a deposition / etch rate that is more easily controlled. The use of two or more frequencies can result in other desirable results, and claimed subject matter is not limited in this respect.

[0054] The multi-station integrated circuit fabrication chamber 165 may also include a viewing port 160 that allows viewing of substrates or wafers currently undergoing fabrication processing within the chamber 165. In some cases, such a viewing port may allow an operator of the processing tool 101 to determine whether an abnormal plasma event is occurring within the fabrication chamber 165. In some cases, an abnormal plasma event may be indicated by a transient burst of light emission, such as a flash or transient burst of visible light having a duration between approximately 1 μs and approximately 100 ms. As previously described, an abnormal plasma event may cause damage to the wafers undergoing fabrication processing and / or may cause damage to the fabrication chamber 165. In other cases, an abnormal plasma event may result in the generation of gaseous compounds within the fabrication chamber that may adversely affect the ongoing fabrication process.

[0055] Figure 2A is a schematic diagram of an exemplary abnormal plasma event detection and location system implemented in a multi-station integrated circuit fabrication chamber according to embodiment 200. Figure 2A , photosensors 205, 210, 215, and 220 are shown as being proximate to one of viewing port 160. Furthermore, photosensors 205, 210, 215, and 220 include fields of view that overlap with the fields of view of at least one other photosensor. Thus, photosensor 205 includes a field of view that overlaps (at least partially) with the fields of view of photosensor 215 and photosensor 220. Thus, in one example, in response to an anomalous plasma event occurring at or near processing station 151, light emissions generated during the event may be detected by photosensor 205 and photosensor 215. In another example, in response to an anomalous event occurring at or near processing station 152, light emissions generated during the event may be detected by photosensor 205 and photosensor 220. Thus, in Figure 2AIn an embodiment, an anomalous plasma event occurring at any one of process stations 151, 152, 153, and 154 can be detected by two of the photosensors 205, 210, 215, and 220. Furthermore, evaluating the output signals from the photosensors 205, 210, 215, and 220 can enable unique identification of the process station of a multi-station integrated circuit fabrication chamber at which (or near which) the anomalous plasma event has occurred. With this in mind, the present disclosure is applicable to any multi-station reactor in which one or more photosensors maintain a line of sight through multiple stations, and two or more of the photosensors maintain intersecting lines of sight, where the intersection occurs at a particular station. By considering readings from multiple PSs with intersecting lines of sight, the system can uniquely identify the station at which a detectable anomalous event has occurred.

[0056] like Figure 2B As shown in (Embodiment 201), the photoelectric sensor can be shaped or configured to receive signals from a limited range of azimuth and elevation angles. Figure 2B As shown, for example, the photosensor 205 may include a field of view depicted as an angle "θ", which may extend in elevation and azimuth. As used herein, the angle "θ" refers to a field of view that includes the proximal processing station and at least a substantial portion of the distal processing station along a radial line extending in a direction perpendicular to the photosensor. Thus, returning to Figure 2A , photosensor 205 includes a field of view that includes at least a majority of processing station 151 (proximal end) and processing station 152 (distal end), both of which are arranged along radial line 170. In a specific, non-limiting example, photosensors 205, 210, 215, and 220 may correspond to silicon-based switchable gain detectors available from Thorlabs Inc. (56 Sparta Avenue, Newton, New Jersey 07860), which may provide for detection of optical signals including wavelengths between about 300 nm and about 1100 nm. However, the claimed subject matter is intended to encompass a variety of photosensors capable of generating electrical signals in response to detecting optical omissions at infrared, visible, and / or ultraviolet wavelengths.

[0057] As mentioned above Figure 2AAs mentioned in the description of FIG, for example, photosensor 205 may include a field of view specifically for detecting abnormal plasma events occurring at or near process stations 151 and 152. Thus, when an abnormal plasma event occurs at or near process station 154 and / or process station 153, light emissions generated in response to the abnormal plasma event may remain undetected by photosensor 205. In response to an abnormal plasma event occurring at or near process station 151 or 152, for example, photosensor 205 may receive a transient burst of light emission, such as in the form of visible light having a wavelength between about 300 nm and about 700 nm. However, in other embodiments, the abnormal plasma event may result in a transient burst of light emission including other wavelengths, such as ultraviolet wavelengths less than about 300 nm (e.g., 100 nm, 200 nm, 250 nm, etc.) and / or infrared wavelengths greater than about 700 nm (e.g., 750 nm, 800 nm, 900 nm, etc.).

[0058] Photosensor 210 may include a field of view similar to that of photosensor 205. Figure 2A In some embodiments, an abnormal plasma event occurring at or near process station 154 or process station 153 may result in a momentary burst of optical emissions that may be received by photosensor 210. Additionally, when an abnormal plasma event occurs at or near process station 151 or process station 152, optical emissions generated in response to the abnormal plasma event may remain undetected by photosensor 210.

[0059] Photosensor 215 may include a field of view similar to the fields of view of photosensors 205 and 210. Thus, an abnormal plasma event occurring at or near process station 154 or process station 151 may result in a momentary burst of optical emissions that may be received by photosensor 215. Furthermore, when an abnormal plasma event occurs at or near process station 152 or process station 153, optical emissions generated in response to the abnormal plasma event may remain undetected by photosensor 215.

[0060] Photosensor 220 may include a field of view similar to the fields of view of photosensors 205, 210, and 215. Thus, an anomalous plasma event occurring at or near process station 152 or process station 153 may result in a momentary burst of optical emissions that may be received by photosensor 220. Furthermore, when an anomalous event occurs at or near process station 151 or process station 153, optical emissions generated in response to the anomalous plasma event may remain undetected by photosensor 220.

[0061] Thus, it can be appreciated that the photosensors 205, 210, 215, and 220 can each include a field of view encompassing a particular processing station of the integrated circuit fabrication chamber 165 while excluding other processing stations of the fabrication chamber 165. Thus, in certain embodiments, monitoring the output signal traces from each of the photosensors 205, 210, 215, and 220 can enable identification of a processing station at which an abnormal plasma event has occurred. Figure 2C In the example discussed, output signal traces from photosensors 210 and 215 reaching a signal level corresponding to a logic "high" may be used to identify process station 154 as being at or near an anomalous plasma event.

[0062] The output signal traces from photosensors 205, 210, 215, and 220 can exhibit amplitudes that are proportional (e.g., linearly proportional) to the intensity of the light emissions received by the photosensors. Thus, in certain embodiments, for example, a relatively high-amplitude burst of light emissions received by photosensor 205 can produce a proportionally high signal at the output port of photosensor 205. Similarly, a relatively low-amplitude burst of light emissions received by photosensor 205 can produce a proportionally low signal at the output port of photosensor 205. Furthermore, for example, an increase or decrease in the amplitude of the output signal present at the output port of photosensor 205 can track or follow the exposure of photosensor 205 to the light signal.

[0063] exist Figure 2AIn certain embodiments, the data acquisition unit 225 can receive output signal traces from the photosensors 205, 210, 215, and 220. In response to receiving one or more of the output signal traces, the data acquisition unit 225 can provide a signal to the computing device 230 indicating that an abnormal plasma event has occurred. Furthermore, the data acquisition unit 225 can be operable to filter out or screen signal traces that do not meet certain predetermined criteria. For example, in certain embodiments, abnormal plasma events having a certain duration (e.g., a duration between about 1 μs and about 100 ms) may be potentially damaging to semiconductor wafers being fabricated. Abnormal plasma events having a duration between about 1 μs and 100 μs may be potentially damaging to an integrated circuit fabrication chamber. Conversely, abnormal plasma events having a duration outside the certain duration (e.g., a duration less than about 1 μs) may be less likely to cause damage to semiconductor wafers being fabricated by the integrated circuit fabrication chamber. Therefore, in response to the data acquisition unit 225 receiving a signal having a duration outside the certain duration from one or more of the photosensors 205, 210, 215, and 220, the signal may be considered insignificant. In a particular embodiment, data acquisition unit 225 may correspond to a multifunction input / output module model number 779676-01, available from National Instruments at 11500 N Mopac Expressway, Austin, Texas 78759-3504. In a specific, non-limiting example, computing device 230 may execute computer-readable instructions stored on a non-transitory medium, such as SignalExpress software for recording, analyzing, and presenting data from measurement devices, also available from National Instruments in Austin, Texas. However, the claimed subject matter is intended to encompass a variety of data acquisition units / modules capable of receiving signals from one or more photosensors, processing the received signals, and transmitting the results of such signal processing to a computing device such as computing device 230.

[0064] Thus, for example, in response to data acquisition unit 225 receiving a relatively high output signal from photosensors 205 and 215 having a duration of approximately 10 ms, data acquisition unit 225 may report to computing device 230 an indication that a signal meeting predetermined indication amplitude and duration criteria has been received. In response, computing device 230 may provide to system controller 190 an indication that an abnormal plasma event has occurred at or near process station 151. In response, system controller 190 may provide an indication that semiconductor wafers being processed at process station 151 should undergo metrology processing, which may include performing electrical measurements, physical inspections, and / or other processing. Conversely, in response to data acquisition unit 225 receiving a relatively high output signal from photosensors 205 and 215 having a duration of approximately 0.9 microseconds (or any other duration less than approximately 1 microsecond), data acquisition unit 225 may not provide a report to computing device 230. Alternatively, under such conditions, data acquisition unit 225 may report the occurrence of an abnormal plasma event, but may mark such an event as insignificant. Thus, computing device 230 may report the occurrence of an insignificant event to system controller 190 , or (alternatively) may refrain from sending any type of report to system controller 190 .

[0065] In response to detecting an abnormal plasma event occurring for a duration greater than approximately 100 ms, the system controller 190 can be operable to adjust or pause the output power level of one or more RF signals generated by the RF power generator 195. Thus, in one example, the system controller 190 can adjust the LF component (e.g., a frequency less than approximately 2 MHz) generated by the RF power generator 195 or can adjust the HF component (e.g., a frequency greater than approximately 2 MHz) generated by the RF power generator 195. Adjusting the output power of the RF power generator 195 can involve reducing the power levels of the LF and HF components generated by the RF power generator 195. In another example, in response to detecting an abnormal plasma event, the system controller 190 can be operable to modify the duty cycle of the RF power generator 195. Thus, in one example, in response to detecting an abnormal plasma event, the system controller 190 can modify the duty cycle of the RF power generator, for example, by reducing the duty cycle from approximately 100% to approximately 95%. It should be noted that the claimed subject matter is intended to encompass system controllers that perform other types of modifications to the RF power generator 195 and that the claimed subject matter is not limited in this respect.

[0066] Figure 2C is an exemplary truth table showing logic states corresponding to output signals of a photosensor implemented in an abnormal plasma event detection and location system for a multi-station integrated circuit fabrication chamber, according to embodiment 202 . Figure 2C The truth table of establishes the correspondence between the output signal of each of the plurality of photosensors (205, 210, 215 and 220) and each station of the multi-station integrated circuit fabrication chamber 165. Figure 2C In the embodiment of Figure 2A The relatively high level output signals of the photosensors 205-220 correspond to a logic "high" signal, while the relatively low level output signals from the photosensors 205-220 correspond to a logic "low" signal. This correspondence between the photosensor logic states and the photosensor output signals may involve one or more comparator circuits within the data acquisition unit 225, where signals with amplitudes greater than a certain threshold are assigned a logic "high". Similarly, signals with amplitudes less than a certain threshold are assigned a logic "low". Therefore, with reference to Figure 2A , in response to detecting an abnormal plasma event at or near the process station 151, the output signals from the photosensors 205 and 215 include a relatively high level corresponding to a logic "high". Figure 2C In one example, in response to the output signals of the photosensors 205 and 215 corresponding to a logic “high” and the output signals of the photosensors 210 and 220 corresponding to a logic “low”, the data acquisition unit 225 may correctly determine that an abnormal plasma event has occurred at or near the process station 151. In another example, in response to the output signals of the photosensors 210 and 220 corresponding to a logic “high” and the output signals of the photosensors 205 and 215 corresponding to a logic “low”, the data acquisition unit 225 may correctly determine that an abnormal plasma event has occurred at or near the process station 153.

[0067] It should be noted that Figure 2A The photoelectric sensor arrangement of (wherein the photoelectric sensors 205, 210, 215 and 220 are located on adjacent sides or edges of the multi-station integrated circuit fabrication chamber 165) corresponds to Figure 2C However, alternative arrangements of photosensors 205, 210, 215, and 220 may correspond to Figure 2C The truth table of the different truth tables, such as the reference Figure 3 The claimed subject matter is intended to cover any arrangement of photosensors located on the side or edge of an integrated circuit fabrication chamber and any truth table created to display the logic states corresponding to the desired photosensor arrangement.

[0068] Figure 2D is an example output signal trace from a photosensor indicating an abnormal plasma event in a multi-station integrated circuit fabrication chamber according to embodiment 203. Figure 2D As shown, corresponding to the Figure 2AThe output signal trace of the photosensor 210 is a signal trace A and corresponds to the signal trace from Figure 2A Signal trace B corresponding to the output signal trace from photosensor 215 is indicated as including an amplitude greater than a logic high. Conversely, signal trace C corresponding to the output signal trace from photosensor 205 and signal trace D corresponding to the output signal trace from photosensor 220 are indicated as including an amplitude less than a logic low. Thus, in response to receiving such logic signal levels, Figure 2C The truth table of indicates an abnormal plasma event at station 154.

[0069] It should be noted that the photosensors 205, 210, 215, and 220 include a field of view that includes the fields along radial lines (e.g., Figure 2A However, reflections within a multi-station integrated circuit fabrication chamber may produce a small subthreshold response in other photosensors. For example, Figure 2D As shown, an abnormal plasma event at or near the processing station 154 generates a signal corresponding to a logic "high" at the output of the photosensors 210 and 215. In addition, reflections within the manufacturing chamber or abnormal plasma events that may not be precisely aligned with the location of the processing chamber 154 may cause such a subthreshold signal. It is understood that, for example, Figure 2D The logic high and logic low thresholds shown in can be determined to some extent through experimentation, which may depend to some extent on the composition and / or concentration of the gases used in the multi-station integrated circuit fabrication chamber. The logic high and logic low thresholds may also depend on the power and frequency content of the RF signal coupled to the fabrication chamber, the reflected power from the fabrication chamber, etc., and claimed subject matter is not limited in this respect.

[0070] In addition, the same Figure 2D As shown, an abnormal plasma event can be characterized as including a particular rise time Δt. In a particular embodiment, the abnormal plasma event results in a signal rise time, wherein the signal trace progresses from an amplitude corresponding to less than a logic low to a level greater than a logic high, ranging from about 1 μs to about 100 ms. However, in certain embodiments, the abnormal plasma event can result in a signal rise time of less than about 1 μs, such as about 0.9 μs, about 0.8 μs, about 0.7 μs, about 0.6 μs, etc., and the claimed subject matter is not limited in this respect. In certain other embodiments, the abnormal plasma event can result in a signal rise time greater than about 100 ms, such as about 110 ms, about 120 ms, about 130 ms, etc., and the claimed subject matter is not limited in this respect.

[0071] Figure 3is a schematic diagram of an example of an abnormal plasma event detection and location system implemented in a multi-station integrated circuit manufacturing chamber according to another embodiment (300). Figure 3 As shown, photosensor 205 includes a field of view that enables detection of abnormal plasma events occurring at or near process stations 151 and 152. Photosensor 210 includes a field of view that enables detection of abnormal plasma events occurring at or near process stations 153 and 154. Photosensor 215 includes a field of view that enables detection of abnormal plasma events occurring at or near process stations 151 and 154. Photosensor 220 includes a field of view that enables detection of abnormal plasma events occurring near process stations 152 and 153. Thus, it can be appreciated that a truth table can be created, such as one similar to Figure 2C The truth table of Figure 3 The logical state of the output signal of the photoelectric sensor is realized.

[0072] Figure 4A is a schematic diagram of an example of an abnormal plasma event detection and location system implemented in a multi-station integrated circuit manufacturing chamber according to another embodiment (400). Figure 4A In the embodiment of FIG, processing stations 651, 652, 653 and 654 are located in a multi-station integrated circuit fabrication chamber 665. Figure 4A , but the controller, RF power generator, computing device and data acquisition unit can be connected to the Figure 2A The multi-station integrated circuit fabrication chamber 665 is connected to the fabrication chamber 665 in a manner similar to that of the fabrication chamber 165. Thus, the multi-station integrated circuit fabrication chamber 665 may be capable of performing film deposition / film etching processes similar to those of the fabrication chamber 165.

[0073] exist Figure 4AIn an embodiment of the present invention, photosensor 605 can be positioned near the viewing port so that light emissions resulting from anomalous plasma events occurring at or near process stations 652, 653, and 654 can be received by photosensor 605. However, the field of view of photosensor 605 can be sufficiently narrow to exclude the receipt of significant light emissions radiating from locations at or near process station 651. Similarly, photosensor 610 can be positioned near the viewing port so that light emissions resulting from anomalous plasma events occurring at or near process stations 651 and 653 can be received by photosensor 610. However, the field of view of photosensor 610 can be sufficiently narrow to exclude the receipt of significant light emissions radiating from locations at or near process stations 652 and 654. Similarly, photosensor 615 can be positioned near the viewing port so that light emissions resulting from anomalous plasma events occurring at or near process station 654 can be received by photosensor 615. However, the field of view of photosensor 615 may be sufficiently narrow to preclude receipt of significant light emissions radiating from locations at or near processing stations 651 , 652 , and 653 .

[0074] Therefore, the arrangement of the processing stations within the multi-station integrated circuit fabrication chamber 665 enables the use of three photoelectric sensors (605, 610, and 615) for abnormal plasma event detection and location, rather than using the associated Figure 2A and 3 The four photosensors in question (205, 210, 215 and 220). Figure 4B is an example showing another embodiment (401) corresponding to Figure 4A The logic state of the output signal of the photoelectric sensor implemented in the exemplary abnormal plasma event detection and location system. Figure 4B In the embodiment of the present invention, a relatively high level output signal from photosensor 610 and a relatively low level signal from photosensors 605 and 615 indicate the presence of an abnormal plasma event at or near processing station 651. Figure 4B In another related example, a relatively high level signal from photosensor 605 and relatively low level signals from photosensors 610 and 615 indicate the presence of an abnormal plasma event at or near process station 652. Figure 4B In another related example, relatively high level signals from photosensors 605 and 610 and relatively low level signals from photosensor 615 indicate the presence of an abnormal plasma event at or near processing station 653. Figure 4B In a related further example, relatively high level signals from photosensors 605 and 615 and a relatively low level signal from photosensor 610 may indicate the presence of an abnormal plasma event at or near processing station 654 .

[0075] Figure 5 is a flow chart of an exemplary method for detecting and locating abnormal plasma events in a multi-station integrated circuit fabrication chamber according to the embodiment (500). It should be noted that the claimed subject matter is intended to cover Figure 5 A variant comprising, in addition to Figure 5 Methods of action other than the action of Figure 5 The actions performed in sequence, including Figure 5 Fewer steps. In addition, although Figure 2A 、 3 and 4A devices may be suitable for performing Figure 5 The invention relates to a method of performing an embodiment of the present invention, but the method may be performed by other devices, systems, or arrangements, and the claimed subject matter is not limited in this respect. Figure 5 The method may begin at 510 and may include receiving output signals from a plurality of photosensors, each photosensor having a field of view of two or more stations of a multi-station integrated circuit fabrication chamber. In certain embodiments, the field of view of at least one photosensor in the plurality of photosensors overlaps with the field of view of at least one other photosensor in the plurality of photosensors.

[0076] Figure 5 The method may continue at 520 by filtering the received output signal to screen for output signals having a magnitude less than a threshold. At 520, filtering may include screening for signals having a duration less than a threshold (e.g., a threshold of approximately 1 μs). The method may continue at 530 by comparing logic states corresponding to the filtered received output signal to identify a station of the multi-station integrated circuit fabrication chamber where an abnormal plasma event has occurred.

[0077] Reference again Figure 1B , the system controller 190 may comprise a portion of the system that may form Figure 1A / 1B is part of an apparatus. Such a system may include semiconductor processing equipment, which includes one or more processing tools, one or more chambers, one or more platforms for processing, and / or specific processing components (wafer pedestals, gas flow systems, etc.). These systems can be integrated with electronic devices for controlling their operation before, during, and after the processing of semiconductor wafers or substrates. The electronic device can be referred to as a "controller", which can control various components or subcomponents of one or more systems. Depending on the processing requirements and / or system type, the controller can be programmed to control any of the processes disclosed herein, including the number of cycles performed on the substrate, the delivery of process gases, temperature settings (e.g., heating and / or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow rate settings, fluid delivery settings, position and operation settings, wafer transfer in and out tools and other transfer tools and / or load locks connected to or interfaced with a specific system.

[0078] In general, a controller can be defined as an electronic device having various integrated circuits, logic, memory, and / or software that receive instructions, issue instructions, control operations, enable cleaning operations, enable endpoint measurements, and the like. The integrated circuits can include chips in the form of firmware that stores program instructions, digital signal processors (DSPs), chips defined as application specific integrated circuits (ASICs), and / or one or more microprocessors, or microcontrollers or field programmable gate arrays (FPGAs) or FPGAs with system-on-chips (SoCs) that execute program instructions (e.g., software). The program instructions can be instructions sent to the controller in the form of various individual settings (or program files) that define operating parameters for performing a specific process on or for a semiconductor wafer or system. In some embodiments, the operating parameters can be part of a recipe defined by a process engineer to complete one or more process steps during the fabrication of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or the die of the wafer.

[0079] In some implementations, the controller can be part of or coupled to a computer that is integrated with the system, coupled to the system, otherwise networked to the system, or a combination thereof. For example, the controller can be in the "cloud" or all or part of a wafer fab host system that can allow remote access to wafer processing. The computer can enable remote access to the system to monitor the current progress of manufacturing operations, review the history of past manufacturing operations, review trends or performance metrics for multiple manufacturing operations, change parameters of the current process, set processing steps to follow the current process, or start a new process. In some examples, a remote computer (e.g., a server) can provide process recipes to the system via a network (which can include a local network or the Internet). The remote computer can include a user interface that enables the input or programming of parameters and / or settings, which are then sent from the remote computer to the system. In some examples, the controller receives instructions in the form of data that specify parameters for each processing step to be performed during one or more operations. It should be understood that the parameters can be specific to the type of process to be performed and the type of tool the controller is configured to interface with or control. Thus, as described above, the controller can be distributed, for example, by including one or more discrete controllers networked together and working toward a common purpose (e.g., processing and control as described herein). An example of a distributed controller for such a purpose is one or more integrated circuits on a chamber communicating with one or more integrated circuits remotely (e.g., at a platform level or as part of a remote computer), which combine to control processing on the chamber.

[0080] In the foregoing detailed description, numerous specific details have been set forth to provide a thorough understanding of the embodiments or implementations presented. The disclosed embodiments or implementations may be practiced without some or all of these specific details. In other cases, well-known processing operations have not been described in detail so as not to unnecessarily obscure the disclosed embodiments or implementations. Although the disclosed embodiments or implementations have been described in conjunction with specific embodiments or implementations, it should be understood that this description is not intended to limit the disclosed embodiments or implementations.

[0081] For the purpose of describing the disclosed aspects, the foregoing detailed description is directed to certain embodiments or implementations. However, the teachings herein may be applied and implemented in a variety of different ways. In the foregoing detailed description, reference is made to the accompanying drawings. Although the disclosed embodiments or implementations are described in sufficient detail to enable those skilled in the art to practice these embodiments or implementations, it should be understood that these examples are not limiting; other embodiments or implementations may be used, and changes may be made to the disclosed embodiments or implementations, without departing from the spirit and scope of the present invention. In addition, it should be understood that, unless otherwise indicated, the conjunction "or" is intended to be inclusive in this document, where appropriate; for example, the term "A, B, or C" is intended to include the following possibilities: "A," "B," "C," "A and B," "B and C," "A and C," and "A, B, and C."

[0082] In this application, the terms "semiconductor wafer," "wafer," "substrate," "wafer substrate," and "partially fabricated integrated circuit" are used interchangeably. It will be understood by those skilled in the art that the term "partially fabricated integrated circuit" can refer to a silicon wafer during any of the many stages of integrated circuit fabrication thereon. Wafers or substrates used in the semiconductor equipment industry may include diameters of 200 mm, or 300 mm, or 450 mm. The foregoing detailed description assumes that the embodiments or implementations are implemented on a wafer, or in conjunction with processes associated with forming or fabricating a wafer. However, the claimed subject matter is not limited thereto. The workpiece may have a variety of shapes, sizes, and materials. In addition to semiconductor wafers, other workpieces that may utilize the claimed subject matter may include various items, such as printed circuit boards, or the manufacture of printed circuit boards, and the like.

[0083] Unless the context of the present disclosure clearly requires otherwise, throughout the specification and claims, the words "comprises," "comprising," and the like are to be interpreted in an inclusive sense, rather than an exclusive or exhaustive sense; that is, in the sense of "including, but not limited to." Words using the singular or plural number generally also include the plural or singular number, respectively. When the word "or" is used to refer to a list of more than two items, the word encompasses all of the following interpretations of the word: any one of the items in the list, all of the items in the list, and any combination of the items in the list. The term "implementation" refers to implementations of the techniques and methods described herein, as well as physical objects embodying such structure and / or incorporating the techniques and / or methods described herein.

Claims

1. An integrated circuit fabrication chamber, comprising: multiple stations; a plurality of viewing ports at least partially transparent to light emissions from at least one of the plurality of stations; a plurality of photosensors, each sensor of the plurality of photosensors being disposed proximate a corresponding one of the plurality of viewing ports to detect light emissions from the at least one of the plurality of stations; as well as a processor configured to identify the at least one of the plurality of stations at which an abnormal plasma event has occurred based at least in part on output signals from at least two of the plurality of photosensors, wherein: a first viewing port of the plurality of viewing ports enables viewing of a first station and a second station of the plurality of stations, a second viewing port of the plurality of viewing ports enables viewing of a third station and a fourth station of the plurality of stations, and A third viewing port of the plurality of viewing ports enables viewing of the first and third stations of the plurality of stations.

2. The manufacturing chamber according to claim 1, wherein The plurality of viewing ports are arranged in adjacent side walls of the fabrication chamber to enable transmission of the light emissions from each of the plurality of stations.

3. The manufacturing chamber according to claim 2, wherein: The plurality of stations includes 4 stations.

4. The manufacturing chamber according to claim 1, wherein One or more of the plurality of viewing ports enables viewing of two or more adjacent stations, but not all stations.

5. The manufacturing chamber according to any one of claims 1 to 4, wherein: The processor identifies the at least one of the plurality of stations at which the abnormal plasma event has occurred in response to evaluating the output signals from the plurality of photosensors.

6. The fabrication chamber of any one of claims 1-4, wherein a fourth viewing port of the plurality of viewing ports enables viewing of the second and fourth stations of the plurality of stations.

7. The manufacturing chamber according to any one of claims 1 to 4, wherein: The viewing port is at least partially transparent to the light emission having a wavelength between 300 nm and 700 nm.

8. The manufacturing chamber according to any one of claims 1 to 4, wherein: The processor is configured to identify the at least one station where the abnormal plasma event has occurred based at least in part on the abnormal plasma event occurring within a duration between 1 μs and 100 ms.

9. The manufacturing chamber according to any one of claims 1 to 4, wherein: The abnormal plasma event includes a transient generation of an electrical discharge between two or more localized regions within one of the plurality of stations.

10. The fabrication chamber of claim 9, wherein the processor is configured to identify the at least one station where the abnormal plasma event has occurred based at least in part on the optical emissions reaching a threshold amplitude in less than 100 ms.

11. The manufacturing chamber of claim 10, wherein: The processor generates a signal to indicate that a semiconductor wafer at the at least one of the plurality of stations is proximate to a location where the abnormal plasma event has occurred.

12. The manufacturing chamber according to any one of claims 1 to 4, wherein: The fabrication chamber is configured to perform a plasma-based etching process or a plasma-based deposition process.

13. A device for detecting an abnormal plasma event, comprising: first, second, and third photosensors, each of the first, second, and third photosensors being disposed at a corresponding viewing port of a multi-station integrated circuit fabrication chamber, each of the first, second, and third photosensors being configured to detect an optical signal having a minimum threshold amplitude within 1 µs and 100 ms; as well as a processor configured to identify a station of a multi-station integrated circuit fabrication chamber that has experienced an abnormal plasma event based at least in part on an output signal level of each of the first and second photosensors, wherein: a first viewing port of the plurality of viewing ports having the first photosensor and enabling viewing of a first station and a second station of the plurality of stations, A second viewing port of the plurality of viewing ports has the second photosensor and enables viewing of a third station and a fourth station of the plurality of stations, and A third viewing port among the plurality of viewing ports has the third photosensor and enables viewing of the first and third stations among the plurality of stations.

14. The device according to claim 13, wherein The processor is configured to identify the station that has experienced the abnormal plasma event based on a truth table that establishes a correspondence between the output signal of each of the first and second photosensors and each station of the multi-station integrated circuit fabrication chamber.

15. The device according to claim 13 or 14, wherein The first and second photosensors are configured to be arranged on adjacent sides of the multi-station integrated circuit fabrication chamber.

16. The apparatus of claim 13 or claim 14, further comprising a fourth photosensor arranged to detect the abnormal plasma event in one of the four stations of the multi-station integrated circuit fabrication chamber.

17. The apparatus of claim 16, wherein a fourth viewing port of the plurality of viewing ports has the fourth photosensor and enables viewing of the second and fourth stations of the plurality of stations.

18. A method for detecting an abnormal plasma event, comprising: receiving output signals from a first photosensor, a second photosensor, and a third photosensor, wherein each of the first photosensor, the second photosensor, and the third photosensor is disposed at a corresponding viewing port of a multi-station integrated circuit fabrication chamber, wherein the first viewing port has the first photosensor and enables viewing of a first station and a second station of the plurality of stations, wherein the second viewing port has the second photosensor and enables viewing of a third station and a fourth station of the plurality of stations, and wherein the third viewing port has the third photosensor and enables viewing of the first station and the third station of the plurality of stations; Filtering the received output signal to select output signals having amplitudes less than a threshold; as well as Logic states corresponding to the filtered received output signals are compared to identify the station in a multi-station integrated circuit fabrication chamber where an abnormal plasma event has occurred. 19 . The method of claim 18 , wherein a field of view of the first photosensor among the plurality of photosensors overlaps a field of view of at least the third photosensor among the plurality of photosensors.

20. The method of claim 18, further comprising filtering the output signal to screen out signals having a duration less than a threshold.

21. The method according to any one of claims 18 to 20, wherein The filtering involves screening out signals with a duration less than 1µs.

22. The method of claim 18, further comprising filtering the output signal to screen out signals having a duration exceeding a threshold.

23. The method according to claim 22, wherein The filtering includes screening out signals with a duration greater than 100 ms.

24. The method of claim 18, further comprising indicating that a measurement process is to be performed on a semiconductor wafer in response to detecting the anomalous plasma event proximate to a semiconductor wafer.

25. An integrated circuit fabrication chamber comprising: multiple integrated circuit manufacturing sites; one or more input ports for coupling a radio frequency (RF) signal to at least one of the plurality of integrated circuit fabrication stations; a plurality of viewing ports at least partially transparent to light emissions emanating from at least one of the plurality of integrated circuit fabrication stations; as well as at least first, second, and third photosensors, each of the at least first, second, and third photosensors being disposed proximate a corresponding one of the plurality of viewing ports to detect light emissions emanating from the at least one of the plurality of integrated circuit fabrication stations, wherein: a first viewing port of the plurality of viewing ports having the first photosensor and enabling viewing of a first station and a second station of the plurality of stations, A second viewing port of the plurality of viewing ports has the second photosensor and enables viewing of a third station and a fourth station of the plurality of stations, and A third viewing port among the plurality of viewing ports has the third photosensor and enables viewing of the first and third stations among the plurality of stations.

26. The integrated circuit fabrication chamber of claim 25, wherein: The plurality of viewing ports are at least partially transparent to light emissions having a wavelength of 300 nm to 700 nm.

27. The integrated circuit fabrication chamber of claim 25, wherein the optical emissions are generated in response to the RF signal coupled to the at least one of the plurality of integrated circuit fabrication stations.

28. The integrated circuit fabrication chamber of claim 25, wherein the plurality of integrated circuit fabrication stations comprises four stations.

29. The integrated circuit fabrication chamber according to any one of claims 25 to 28, wherein: The at least first and second photosensors provide an output signal having a duration of at least 1 μs in response to detecting the light emission.

30. The integrated circuit fabrication chamber of claim 29, wherein the at least first and second photosensors provide output signals to a processor for identifying a station of the plurality of integrated circuit fabrication stations at which an abnormal plasma event has occurred.

31. The integrated circuit fabrication chamber of claim 30, wherein the processor is to identify the station of the plurality of integrated circuit fabrication stations based at least in part on output signals from the first and second ones of the at least first and second photosensors.

32. The integrated circuit fabrication chamber of claim 25 , further comprising a fourth photosensor disposed proximate a fourth of the plurality of viewing ports to detect the light emission from at least one of the plurality of integrated circuit fabrication stations, wherein the fourth of the plurality of viewing ports enables viewing of the second and fourth stations of the plurality of stations.

Images