REACTOR SYSTEM WITH SOURCE VESSEL WEIGHT MONITORING

A source vessel weight monitoring assembly for use in reactor systems to provide real-time and direct measurements of the availability of source or process materials from a source vessel. The assembly includes one or more force or load sensors, such as load cells, positioned between a bottom wall of the source vessel and a support element for the vessel (e.g., a base of a source vessel enclosure). The sensors are positioned to at least partially support the vessel, and a signal conditioning element processes the output electrical signals from the sensors, then a controller processes the output signals from the signal conditioning components with a conversion factor, for example, to determine a current weight of the source vessel and process material (e.g., solid, liquid, or gaseous precursor) stored therein. The controller uses this weight to calculate the amount of available process material or chemistry in the source vessel.

FIELD OF THE DISCLOSURE

The present disclosure relates generally to semiconductor fabrication methods and systems using precursor or other process materials stored, typically at high temperatures and wide range of pressures including vacuum, in system source vessels, and, more particularly, to methods and apparatus for monitoring levels or amounts of process materials, such as precursors, reactants, and the like, in solid, liquid, or gaseous form, in source vessels.

BACKGROUND OF THE DISCLOSURE

During a deposition process, deposition or process material, which may be delivered to a wafer for example, is stored inside a temperature- and pressure-controlled source vessel inside the reactor system or tool, and the source vessel itself may be located in an enclosure at higher temperatures and wide range of pressures (e.g., within a vacuum oven). In some cases, the source vessel is stored within a source enclosure or cabinet (which may take the form of a vacuum oven in some cases) that is fluidically connected to or in communication with a reaction or processing chamber. For example, a solid source vessel may be used to provide a precursor to a wafer on a substrate support or susceptor in a reaction chamber. During wafer processing, the precursor is consumed. When the source vessel is running out of or low on the precursor (or other processing material), the amount of vapor reaching the wafer may get affected, which can cause non-uniform deposition between wafer-to-wafer runs in the reactor system or even on a particular wafer. Such non-uniformity can lead to scrap wafers, and the batch of wafers may need to be re-run after the source vessel is refilled, which causes lower throughput.

Typical reactor systems do not provide any way to directly monitor how much chemistry is available inside a source vessel at any given time. Presently, system operators may simply wait until no or non-uniform deposition is observed to determine that a chemical source is depleted and needs refilling. In some cases, the amount of chemistry that has been used is calculated based on dose pulses after refill is performed, but errors can lead to inaccuracies in this indirect source monitoring approach. Hence, there remains a demand for a direct measurement solution for monitoring the availability of process or source materials in the source vessels of a reactor system to prevent dosage drift which may arise if precursor consumption is not monitored and falls below a certain level.

SUMMARY OF THE DISCLOSURE

Disclosed herein, according to various embodiments, is a source vessel weight monitoring assembly for use in reactor systems to provide real-time and direct measurements of the availability of source or process materials from a source vessel. The assembly includes a plurality of sensors, such as load cells, positioned between a bottom wall of the source vessel (with a vessel support plate and a heater plate being disposed between the bottom wall and the sensors in some implementations) and a support element for the vessel (e.g., a base of a source vessel enclosure, which may take the form of a vacuum oven in some example systems). The sensors are positioned to at least partially support the vessel, and a signal conditioning element conditions the electrical signals from the load cell, and a controller processes the output signals from the signal conditioning element with a conversion factor, for example, to determine a current weight of the source vessel and process material (e.g., solid, liquid, or gaseous precursor) stored therein. The controller uses this weight to calculate the amount of available process material or chemistry in the source vessel, which can be reported to a reactor system operator to indicate a need for source refill prior to any issues with scrap or deposition non-uniformity in a reactor chamber supplied by the source vessel.

In some exemplary embodiments of the description, a reactor system is described that is adapted for monitoring source availability. The system includes a reaction chamber, a source enclosure (such as a vacuum oven), and a source vessel positioned in the source enclosure. The vessel includes an interior space adapted for receiving a volume of a source material, and the interior space is fluidically coupled to the reaction chamber. The system further includes a vessel weight monitoring assembly including a sensor assembly positioned in the source enclosure operable to sense a weight of the source vessel.

In some exemplary implementations of the system, the sensor assembly includes a plurality of force sensors, positioned between a bottom wall of the source vessel and a support element of the source enclosure, supporting at least a portion of the weight of the source vessel. The one or more force sensors each outputs an electrical signal indicative of a force applied by the source vessel on the one or more force sensors. In some cases, the force sensors include three load cells arranged in a circular pattern at 120-degree offsets, whereby the force applied to each of the three load cells is substantially equal. The system may include a vessel base heater positioned between the bottom wall of the source vessel and the support element, and the force sensors include a pneumatic load cell embedded in an outer surface of the vessel base heater.

The vessel weight monitoring assembly may further include a signal conditioning device for processing the signal of each of the one or more force sensors to calculate a weight of the source material. The processing of the signal can include amplifying the electrical signals from the load cells. The vessel weight monitoring assembly may further include a controller. The controller’s purpose or functionality is applying a conversion factor to the overall measured or gross weight of the vessel that is adapted to remove a weight of the source vessel and supporting forces applied on a lid of the source vessel by lid-attached hardware. The controller can be configured (or programmed) to generate at least one of a graphical user interface (GUI) in a display that includes imagery or text indicative of the weight or an alert based on a comparison of the weight to a refill alarm threshold. The lid-attached hardware can include at least one input line and at least one output line each including at least one of a bellow, coil gas lines, or hard gas lines to reduce the supporting forces applied to the lid. In the system, an inner space of the source enclosure has or can have an operating temperature greater than 150° C.

According to other aspects of the description, a reactor system is provided that is adapted for monitoring source availability. This system includes a source enclosure and a source vessel positioned in an inner space of the source enclosure. The source vessel includes a bottom wall, a lid, and a sidewall defining an interior space for receiving a process material. The system further includes one or more force sensors positioned within the inner space of the source enclosure to at least partially support the source vessel, and the plurality of force sensors each outputs a signal indicative of a force applied on the one or more force sensors. A signal conditioning element is provided to condition electrical signals coming from sensors. A controller is provided in the system that processes the signals output by the one or more force sensors to determine a weight of the process material.

In some embodiments of this system, the force sensors include three load cells arranged in a pattern whereby the force applied to each of the three load cells is substantially equal. In other embodiments, the system includes a vessel base heater positioned between the bottom wall of the source vessel and the support element, and the one or more force sensors comprise a pneumatic load cell embedded in an outer surface of the vessel base heater.

The processing of the signal by the controller includes applying a conversion factor to the gross measured or detected weight to account for a weight of the source vessel and supporting forces applied on a lid of the source vessel by lid-attached hardware. In some cases, the controller generates at least one of a graphical user interface (GUI) in a display that includes imagery or text indicative of the weight or an alert based on a comparison of the weight to a refill alarm threshold. In these or other example systems, the lid-attached hardware includes at least one input line and at least one output line each including at least one of a bellow and a coil to reduce the supporting forces applied to the lid.

According to further aspects of the description, a method is described of monitoring availability of source material in a reactor system. The method includes receiving at least one signal, and typically a plurality of signals, from a set of force sensors positioned between a source vessel and a support element vertically supporting the source vessel in the reactor system. The method also includes converting the at least one signal to a weight measurement and calculating a weight of source material in the source vessel based on the weight measurement. In some cases, the volume of precursor is determined using the density of the precursor, with Volume = Weight/Density. This will be helpful when dealing with a liquid because liquid density changes with temperatures and liquid volume inside the vessel can be further used to find the vapor pressure.

The calculating of the weight can include applying a conversion factor to account for a weight of the source vessel and for lifting forces applied on a lid of the source vessel by lid-attached hardware. In some implementations, the set of force sensors includes at least three load cells arranged to each receive an equal or substantially equal (e.g., within 5 percent) proportion of forces applied by the source vessel upon the set of force sensors. The method may further include generating a GUI with imagery or text indicative of the weight of the source material. Additionally, the method can include comparing the weight of the source material to a refill alarm setpoint, and, based on the comparing, generating a refill alert.

All of these embodiments are intended to be within the scope of the disclosure. These and other embodiments will become readily apparent to those skilled in the art from the following detailed description of certain embodiments having reference to the attached figures, the disclosure not being limited to any particular embodiment(s) discussed.

DETAILED DESCRIPTION

Although certain embodiments and examples are disclosed below, it will be understood by those in the art that the disclosure extends beyond the specifically disclosed embodiments and/or uses of the disclosure and obvious modifications and equivalents thereof. Thus, it is intended that the scope of the disclosure should not be limited by the particular embodiments described herein.

The illustrations presented herein are not meant to be actual views of any particular material, apparatus, structure, or device, but are merely representations that are used to describe embodiments of the disclosure.

As used herein, the term “chemical vapor deposition” (CVD) may refer to any process wherein a substrate is exposed to one or more volatile precursors, which react and/or decompose on a substrate surface to produce a desired deposition.

As used herein, the term “atomic layer deposition” (ALD) may refer to a vapor deposition process in which deposition cycles, preferably a plurality of consecutive deposition cycles, are conducted in a process chamber. Typically, during each cycle the precursor is chemisorbed to a deposition surface (e.g., a substrate surface or a previously deposited underlying surface such as material from a previous ALD cycle), forming a monolayer or sub-monolayer that does not readily react with additional precursor (i.e., a self-limiting reaction). Thereafter, if necessary, a reactant (e.g., another precursor or reaction gas) may subsequently be introduced into the process chamber for use in converting the chemisorbed precursor to the desired material on the deposition surface. Typically, this reactant is capable of further reaction with the precursor. Further, purging steps may also be utilized during each cycle to remove excess precursor from the process chamber and/or remove excess reactant and/or reaction byproducts from the process chamber after conversion of the chemisorbed precursor. Further, the term atomic layer deposition, as used herein, is also meant to include processes designated by related terms such as, chemical vapor atomic layer deposition, atomic layer epitaxy (ALE), molecular beam epitaxy (MBE), gas source MBE, or organometallic MBE, and chemical beam epitaxy when performed with alternating pulses of precursor composition(s), reactive gas, and purge (e.g., inert carrier) gas.

As described in greater detail below, various details and embodiments of the disclosure may be utilized in conjunction with processes carried out in reactor systems, e.g., semiconductor fabrication systems, to monitor an amount of a process material available for a reaction or process chamber. The “processes” may include nearly any normally carried out in such reactor systems such as deposition, etching, purging, and the like that may be performed during ALD, CVD, and other processes on a substrate (e.g., a wafer). The “process material” (or “source” or “source material”) may be provided to the reaction chamber from a source vessel where it may in solid, liquid, or gaseous form and may include precursors, reactants, and the like used during the processes performed during operations of the reactor system.

Reactor systems having direct measurement-based methods may provide the ability to monitor availability of source or process materials in source vessels. Accordingly, various embodiments of the present technology disclose a reactor system comprising a vessel weight monitoring assembly. Exemplary assemblies can be configured, as described in detail below, to directly monitor the weight of a source vessel and to, in response, update the system operator or user on the quantity of chemistry or source/process material available in the source vessel. With this information, the refill sequence for the source vessel can be planned, thereby preventing wafer wastage. In various embodiments, the source vessels may be in vessel enclosures, such as vacuum ovens, where operating temperatures are high (e.g., exceeding 150 to 200° C. or even exceeding 300° C. in some cases) and where operating pressures are low (e.g., lower than atmosphere).

FIG.1is a functional block diagram of a reactor system100of the present description with a vessel weight monitoring assembly150operable to monitor source availability based on vessel weight measurements (e.g., via calculation of quantity of process or source material such as a solid precursor or the like129in a source vessel120). The system100is shown in simplified form, but it will be understood by those skilled in the art that additional components, such as other source vessels120, gas or material distribution systems, a system controller, and the like may be included as useful for performing ALD, CVD, or other semiconductor or fabrication processes.

As shown, the system100includes a vessel enclosure110that is used to contain the source vessel120. The enclosure110may be configured, such as a vacuum oven, to heat the vessel120such as to temperature in the range of 150 to 300° C. or greater and maintain the interior space112in which the vessel120is placed at desired pressures, such as below atmosphere. The source vessel120includes an inner space128adapted for receiving and containing a quantity of process or source material129, and this space128is defined by sidewall(s)122, a bottom wall124, and a vessel lid126, which all may be formed of a metal such aluminum, a steel, or the like to facilitate efficient heat transfer to the material129.

The vessel enclosure110includes a support element114for supporting (in a vertical direction) the vessel120within the interior space112, and, in some embodiments, an additional support plate (not shown inFIG.1but shown inFIG.3) may be disposed between the support element114and the lower or outer surface of the bottom wall124to retain the vessel120at a height above the support element114(e.g., spaced apart 10 to 30 mm or the like). The system100further includes a set of lid-attached hardware130including one or more outlet tubes or pipes132for fluidically coupling the space128with the reaction chamber inner space142to facilitate delivery of the process material (e.g., a precursor)129to the reaction chamber140, as shown with arrow134, during processing operations of the system100. In this regard, the reaction chamber140includes a substrate support or susceptor144for supporting substrates (e.g., wafers)146within inner space142of the chamber140to be exposed to the process material129.

In practice, the weight of vessel120is supported by the support element114of the enclosure110and also, to some degree, by the lid-attached hardware130as shown with arrow F1. In addition to outlet piping132, the lid-attached hardware130may include inlet piping, sensor lines, and the like. In some embodiments, the outlet piping132(and/or inlet piping) as well as other lid-attached hardware130may be designed to provide less vertical support of the vessel120such that a larger portion of the weight of the vessel120is supported by the support element114to facilitate direct measurement of the vessel weight. In brief, the hardware130such as line(s)132may be bellowed, coiled gas lines, or hard gas lines or the like to apply minimal lifting force upon the lid126and/or vessel120.

To provide direct measurement and monitoring of the quantity of the process material129in the vessel120, the system100includes the vessel weight monitoring assembly150. The assembly150includes a sensor assembly152that is positioned, at least partially, within the inner space112of the enclosure112. Particularly, the assembly includes one, two, three, or more force or load sensors154,156, e.g., load cells or the like, that are positioned or disposed between the bottom wall124of the vessel120(and, in some cases, a support plate attached to the bottom wall124as shown inFIG.3) and the upper surface of the support element114. The force sensors154,156are positioned so as to support the full weight of the vessel120(and, as appropriate, weights of a heater plate and a vessel plate (not shown but included in various embodiments of a vessel enclosure110) and source or process material129(as shown by arrows F2to FN) reduced by lift or vertical upward forces applied to the vessel lid126by the lid-attached hardware130. To this end, the force sensors154,156are devices designed to translate applied mechanical forces, such as compressive forces, into output signals157whose values can be used to reflect the magnitude of the forces (or weight of vessel120).

As shown, the signals157output by the force sensors154,156are transmitted (in a wired or wireless manner) first to signal conditional elements158(with one provided for each load cell or sensor154,156in most cases) to generate a conditioned signal159that is provided to a controller160of the monitoring assembly150. The signal conditioning element(s)158conditions the electrical signal from each load cell or other sensor154,156, such as by amplifying the electrical signal from the load cell. The controller160may take the form of nearly any computer device and is shown to include a processor(s)162that manages operations of input and output (I/O) devices164, which function to receive the signals157output by the sensors154,156. The processor162executes code, instructions, and/or software (which may be in memory/data storage180) to provide the functions of a weight monitoring module170. The processor162also manages memory180including storing and accessing the signals157as shown at182.

The module170acts to process the received load signals182including applying a conversion factor(s)180from memory182to calculate the current vessel and source material weights186. In brief, the conversion factors184are generated through testing and calibrating the sensors154,156to convert the signals182indicative of the sensed forces, F2to FN, into units of force or load, e.g., grams. The conversion factors184, which may include algorithms, may also be used by the module170to determine the quantity of the material129by first determining the overall or gross weight of the vessel120and material129stored in the vessel120by adding the forces, F1, applied by the lid-attached hardware130(and/or other components in the space112contacting the vessel120) to the sensed forces, F2to FN, and then subtracting the known weight of the vessel120when empty.

With the calculated source or process material weight186in hand, the module170can determine whether refilling is required. The module170may retrieve a refill alarm setpoint188(e.g., a minimum amount or weight of material129desired in the vessel120for further processing by system100such as 100 grams for some vessel designs and some particular process materials129) and compare this with the calculated weight or quantity186of the material129currently in the vessel120. When the source weight186is at or below the setpoint188, the module172may provide an alarm, or other suitable indicator, to an operator of the system100such as via an audible alarm, a visual alarm, a digital message to a client device, and/or other messaging processes.

In this regard, the weight monitoring assembly170may include a graphical user interface (GUI) generator172that is adapted to generate and display a weight monitoring GUI192in a display190(or operator’s client device). The weight monitoring GUI192may include imagery and/or text messaging indicating information useful in monitoring the source or process material129and its availability, and this displayed information may include current quantities of the material129as directly measured by the assembly150along with the refill alarm setpoint188(e.g., with a display similar to an automobile speedometer or the like). The information displayed in the GUI192may also include an indicator that the calculated source quantity186is below or at the setpoint188(or has not yet met the setpoint188) such as with a red light when refilling is indicated and a green light when refilling is not indicated (and, in some cases, a yellow light when refilling will be desirable soon).

FIG.2illustrates schematically the design and operation of a vessel weight monitoring assembly200such as may be used as assembly150in the reactor system100ofFIG.1. The assembly200includes three load sensors230positioned between a bottom wall of a vessel214and a support element212(e.g., a bottom wall of a source enclosure). The assembly200further includes bellowed, coiled gas lines, or hard gas lines or the like220(input/output lines making up part of lid-attached hardware) for inputting material during refill or outputting material during wafer/substrate processing via valves222coupled to a lid of the vessel214. The bellowed lines220are each shown to be coupled at a lower end to one of the valves222(and lid of vessel214) and at an upper end to an upper support element210(e.g., a top wall of the source enclosure). The lines220apply a lifting or upward supporting force, W1, on the vessel214, which is reduced in magnitude by the use of bellows (or coils/loops) in lines220when compared to rigid conventional lines (which are typically hard plumbed) found in many reactor systems and such reduction is desirable for increasing the accuracy of the weight measurement of the vessel214via load sensors230.

The assembly200is useful for directly monitoring changes in gross weight of a source (e.g., a precursor) vessel214using the load sensors230as the weight changes during source (e.g., precursor such as HFCl4or the like) consumption. The load sensors230may be placed under the vessel214(its bottom wall) or a support plate or frame holding the vessel214within an enclosure (e.g., a vacuum oven or the like). Electrical wire(s)240, e.g., electrical wire compatible with high temperatures within vessel enclosure110, is used to communicatively link each sensor230with a signal condition device or element246via a vacuum electrical feedthrough244(e.g., feedthrough compatible with high temperatures in enclosure110) in the enclosure110or its wall. The signal conditioning devices246condition the electrical signals from each load sensor230as discussed above (such as by applying a conversion factor) prior to the conditioned signals being provided to the tool I/O250(such as I/O164inFIG.1for controller162).

Weight is proportionally divided across supports as shown by the arrows, W1to W4, with W1representing loads carried by lines220(and/or other hardware in the enclosure) and with W2, W3, and W4representing loads carried by and sensed by load sensors230. The total load is equal to the vessel weight plus the weight of the precursor/source, Wx, in the vessel214, and changes in the sum of weights (or sensed loads) W2, W3, and W4are proportional to changes in the source or process material weight such that a conversion factor (e.g., a numerical model to correlate change in precursor weight to change in this sum of sensed forces/loads) can be determined via testing and calibration and then applied to measure values for these forces/loads to calculate the weight of the source or process material within the vessel214.

FIG.3is side perspective view of a portion of a reactor system300including one exemplary implementation of a sensor assembly of a vessel weight monitoring assembly of the present description. As shown, a source vessel310is provided within an interior space of an enclosure (e.g., a vacuum oven) that includes a support element or bottom320upon which the vessel310is vertically supported. The vessel310includes a sidewall312, a lid or top wall314and a bottom wall316, which together define an inner space configured or adapted to receive a quantity of source or process material (e.g., a precursor or the like). The system300also includes hardware318attached to the lid314, and this hardware318applies some upward forces upon the vessel310such that the entire weight of the vessel310is not borne by the support element320(and needs to be accounted for in source weight calculations as discussed above with reference toFIG.2).

The vessel310in the illustrated embodiment ofFIG.3is mounted upon a support plate or frame324in the enclosure, and the sensor assembly includes three force sensors in the form of load cells. One of these load cells330is in view inFIG.3and is shown to be positioned or disposed between the bottom wall316of the vessel310and the upper surface of the enclosure support element320. More particularly, the load cell330is affixed or mounted to a bottom surface of support plate or frame324, which is abutting the bottom wall316of the vessel310. With this arrangement, all of the weight of the vessel310is supported by the load sensors including the load cell330except for that borne by the lid-attached hardware318. In some cases, the pneumatic lines are coiled or bellowed to try to ensure the vessel is floating or nearly floating upon the load cells330. Additional design aspects may include ensuring the heater cable (which may be part of hardware318but not shown in detail inFIG.3) is flexible and that the valve plate (which may be part of hardware318in some case but is not shown in detail inFIG.3) is not supported by the vessel310.

FIG.4is a schematic bottom view of the reactor system300ofFIG.3showing positioning of three load sensors330,432,434of the sensor assembly relative to an outer surface425of the vessel bottom support plate or frame324. One, two, or four or more load cells may be used to implement the sensor assembly, with three being useful in some implementations as this number can readily be arranged in a circular pattern to equally or substantially equally balance the loads (e.g., equal portion of vessel and source weight is applied to each load sensor330,432,434). As shown, the load sensors330,432,434are arranged equidistally from the plate center427, with dsensorbeing equal for all three and being relatively close to the size of the plate radius, RBottom, so that the sensors330,432,434are near the peripheral or outer edges of the plate324. The sensors330,432,434are positioned about the outer edge of the plate324in a circular pattern so as to be radially separated by matching angles, θ, of 120 degrees.

A variety of sensors may be used for the sensors330,432,434. In some cases, the vertical spacing may limit the choice of sensor, with one exemplary implementation requiring that the overall vertical height of each sensor (which may be the sensor thickness plus a height of a sensor mounting fastener used to mount the sensor to the support element or bottom of the enclosure) be about 15 mm. The sensor may also be able to be used in higher temperature applications such as temperatures greater than 200° C., 250° C., or 300° C., and the operating range of the sensor should meet or exceed expected use temperatures. In various embodiments, the system may integrate any suitable load sensors or cells such as a 30 N load sensor with an operating range of 200° C., a100N load sensor with an operating range of 200° C., or the like. Modifications to communication lines from such sensors may be desired to suit a particular application such as an environment inside a vacuum oven.

FIG.5provides graphical results500of three calibration runs for a sensor assembly with three load sensors (as shown inFIGS.3and4) used to determine source or process material weights in a source vessel. Graph510shows results of a calibration run with no lines connected to the vessel except a heater line, graph520shows results of a calibration run with all hard lines (e.g., lid-attached hardware) connected to the vessel lid, and graph530shows results of a calibration run with modified gas lines (bellows combined with coils) connected to the vessel lid. Testing involved loading and unloading of known amounts of weight, with the vessel weight zeroed to provide a measurement of the precursor/process material. Load sensor repeatability and accuracy were shown to be acceptable, with the heater line not affecting results. Using flexible input and output lines was desirable for providing the reading closer to that of the process material.

FIG.6illustrates another portion of a reactor system including another exemplary implementation of a sensor assembly at least partially embedded in a vessel base heater. Particularly, a vessel base heater610is illustrates that has been modified to include a load cell620inside the heater surface611. The force sensor620may be chosen to be capable of withstanding high temperatures, such as 300° C. or greater.

A single load sensor620is shown that may take the form of a pneumatic or pan-style load cell. Particularly, the sensor620may include a source of pressurized air or gas that is fed through a pressure regulator to a chamber inside the load cell. A flexible diaphragm is compressed when a compressive force (e.g., the weight of the vessel containing source or process material) is applied to the top surface of the load cell. A pressure gauge measures the pneumatic pressure result from the weight/compressive force being applied, and the amount of pressure needed to balance out the weight of the object being measured can be used to measure the weight. The sensed pressure is converted to an electrical signal communicated to a controller (as discussed with reference toFIG.1) for conversion into a weight and for use in calculating the current weight of the material in the vessel supported by the base heater610.

FIG.7is a flow diagram of an exemplary source or process material availability monitoring method700that may be performed by operation of the reactor systems described inFIGS.1-6based on direct vessel weight measurements. The method700starts at705such as with installing a vessel weight monitoring assembly (such as the assembly150ofFIG.1) in a reactor system including providing a sensor assembly within a source vessel enclosure. The method700then continues at710with receiving output signals from the one or more sensors of the sensor assembly operating to sense changes in the weight of a source vessel. At step720, the electrical signals from the sensors are converted, such as by a controller or by a conversion module/device, to a weight (or force) measured for the source vessel that contains a volume of source or process material. The method700continues at730with the controller using a weight monitoring module to calculate the current weight (or quantity) of source or process material in the source vessel based on the vessel weight of step720.

At step740, a determination is made (e.g., by a monitoring assembly controller) as to whether the weight calculated in step730is at or below the refill alarm threshold (e.g., is weight of material at or below 100 grams or the like). If not, the method700may continue at step750with updating the user interface displayed to a system operator on a display device (e.g., a computer monitor, a client device display, or the like) to reflect the current material weight. The method700may then continue at710with receiving additional signals from the sensor assembly. If at740the material weight is determined to be at or below the threshold, the method700may continue at760with the controller generating a refill alert or alarm, which may involve providing a red indicator light in a user interface of the operator’s display, may involve providing an audible alarm, and/or may involve generating and transmitting an alert message to the operator (e.g., sending an e-mail, a text message, or the like to an operator client device). The method700may then end at790such as until after the vessel has been refilled.

In various embodiments of the description, the force sensors may be implemented using a compact, stainless steel, single point, strain gauge-based load cell, which may have a range of 0 to 100N. The load cell may be mounted under a precursor vessel for enabling real-time weight direct measurement of precursor and vessel. In some cases, three load sensors are mounted right under the vessel holding plate and situated equally at 120-degrees angles. Then, in operations, the total weight measured will be the sum of all three load sensors readings. The load cell weight measurement response is linear after each vessel change.

In practice, hard gas lines affect the actual weight measurement of the load cell by a constant factor. The constant factor depends on the line stiffness. The constant factor does not typically change as long as the vessel and gas lines are not physically contacted or modified. Generally, the load cell reading is not affected by the vacuum in the steady state. The load cell chosen to act as the force sensor is compatible with a high-temperature environment such as one with temperatures up to 225° C., with wire material often being a design limitation.

Operations of the weight monitoring assembly include receiving electrical signals from the load cells and using signal condition divide for each load cell to condition the electrical signals coming from each load cell. A processor performing an algorithm(s) then converts the conditioned signal to a weight value using a calibration factor generated for each load cell. Then, the weight value measured by load cells is then compared to the predefined threshold value for the vessel. Next, an alarm is generated if the weight is below the threshold; otherwise, the display and user interface is updated based on the measured weight.

Benefits, other advantages, and solutions to problems have been described herein with regard to specific embodiments. However, the benefits, advantages, solutions to problems, and any elements that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as critical, required, or essential features or elements of the disclosure.

Furthermore, the described features, advantages, and characteristics of the disclosure may be combined in any suitable manner in one or more embodiments. One skilled in the relevant art will recognize that the subject matter of the present application may be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments of the disclosure. Further, in some instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the subject matter of the present disclosure. No claim element is intended to invoke 35 U.S.C. 112(f) unless the element is expressly recited using the phrase “means for.”

The scope of the disclosure is to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more.” It is to be understood that unless specifically stated otherwise, references to “a,” “an,” and/or “the” may include one or more than one and that reference to an item in the singular may also include the item in the plural. Further, the term “plurality” can be defined as “at least two.” As used herein, the phrase “at least one of”, when used with a list of items, means different combinations of one or more of the listed items may be used and only one of the items in the list may be needed. The item may be a particular object, thing, or category. Moreover, where a phrase similar to “at least one of A, B, and C” is used in the claims, it is intended that the phrase be interpreted to mean that A alone may be present in an embodiment, B alone may be present in an embodiment, C alone may be present in an embodiment, or that any combination of the elements A, B and C may be present in a single embodiment; for example, A and B, A and C, B and C, or A, B, and C. In some cases, “at least one of item A, item B, and item C” may mean, for example, without limitation, two of item A, one of item B, and ten of item C; four of item B and seven of item C; or some other suitable combination.

Although exemplary embodiments of the present disclosure are set forth herein, it should be appreciated that the disclosure is not so limited. For example, although reactor systems are described in connection with various specific configurations, the disclosure is not necessarily limited to these examples. Various modifications, variations, and enhancements of the system and method set forth herein may be made without departing from the spirit and scope of the present disclosure.

The subject matter of the present disclosure includes all novel and nonobvious combinations and subcombinations of the various systems, components, and configurations, and other features, functions, acts, and/or properties disclosed herein, as well as any and all equivalents thereof.