Systems and methods for determining flow characteristics of a fluid segment for analytic determinations

Abstract

This invention describes a system and method for determining whether liquid remains on a wafer surface after a scanning operation. One system embodiment includes, but is not limited to: a first system configured to be positioned adjacent to a delivery line coupled to a scanning nozzle for dispensing fluid onto and recovering fluid from a wafer surface, the first system being configured to detect a gas / liquid transition of the fluid and determine a volume of the dispensed liquid sample; a second system configured to be positioned adjacent to a second line downstream of the scanning nozzle, the second system being configured to detect a gas / liquid transition of fluid flowing through the second line and determine a volume of the liquid sample recovered from the wafer surface; and a controller configured to generate an alarm if the volume of the recovered liquid sample is not within a critical limit compared to the volume of the dispensed liquid sample.

Description

[Previous Technology]

[0001] Inductively coupled plasma (ICP) spectroscopy is an analytical technique commonly used to determine the concentration and isotope ratio of trace elements in liquid samples. ICP spectroscopy utilizes electromagnetically generated partially ionized argon plasma, reaching a temperature of approximately 7,000 K. When a sample is introduced into the plasma, the high temperature causes the sample atoms to ionize or emit light. Because each chemical element produces a characteristic mass or emission spectrum, measuring the emission mass or the spectrum of light allows for the determination of the elemental composition of the original sample.

[0002] A sample introduction system can be used to introduce liquid samples into an ICP spectrometer (e.g., an inductively coupled plasma mass spectrometer (ICP / ICP-MS), an inductively coupled plasma atomic emission spectrometer (ICP-AES), or the like) for analysis. For example, a sample introduction system can transport an aliquot of a sample to a nebulizer, which converts the aliquot into a polydisperse aerosol suitable for ionization in plasma by an ICP spectrometer. The aerosol generated by the nebulizer is then sorted in a spray chamber to remove larger aerosol particles. After exiting the spray chamber, the aerosol is introduced into the plasma for analysis by a plasma torch assembly of an ICP-MS or ICP-AES instrument. [Summary of the Invention]

[0003] This invention describes a system and method for determining the flow characteristics of a fluid segment flowing through a fluid delivery line. One system embodiment includes, but is not limited to: a first liquid volume determination system configured to be located adjacent to a first fluid delivery line, the first fluid delivery line being in fluid communication with a scanning nozzle configured to apply a fluid to a wafer surface and recover the fluid from the wafer surface for delivery to an analysis system; the first liquid volume determination system being configured to detect a gas / liquid transition of the fluid flowing through the first fluid delivery line and determine a volume of a liquid sample applied to the wafer surface; and a second liquid volume determination system configured to be located adjacent to a first fluid delivery line. A two-fluid delivery line is located downstream of the scanning nozzle and the first liquid volume determination system. The second liquid volume determination system is configured to detect a gas / liquid transition of the fluid flowing through the second fluid delivery line and determine a volume of liquid sample recovered from the wafer surface. A controller is configured to compare the volume of the liquid sample recovered from the wafer surface with the volume of the liquid sample applied to the wafer surface, and to generate an alarm if the volume of the liquid sample recovered from the wafer surface is not within a critical limit compared to the volume of the liquid sample applied to the wafer surface.

[0004] One method embodiment includes, but is not limited to: conveying a fluid sample from a fluid source to a scanning nozzle of a wafer processing system via a fluid delivery line; applying the fluid sample to a wafer surface using the scanning nozzle; determining a volume of the liquid sample applied to the wafer surface via a first liquid volume determination system located downstream of the fluid source and upstream of the scanning nozzle; recovering the fluid sample from the wafer surface using the scanning nozzle; determining a volume of the liquid sample recovered from the wafer surface via a second liquid volume determination system located downstream of the scanning nozzle; comparing the volume of the liquid sample recovered from the wafer surface with the volume of the liquid sample applied to the wafer surface via a controller communicatively coupled to the first liquid volume determination system and the second liquid volume determination system; and generating an alarm if the volume of the liquid sample recovered from the wafer surface is significantly smaller than the volume of the liquid sample applied to the wafer surface.

[0005] This [Summary] is provided to introduce, in a simplified form, a concept selection further described below in the [Description] section. This [Summary] is not intended to identify key or essential features of the claimed object, nor is it intended to serve as an aid in determining the scope of the claimed object.

Implementation Method

[0018] Overview

[0019] Determining the concentration or amount of trace elements in a sample can provide an indication of the sample's purity, or its acceptability as a reagent, reactive component, or the like. For example, in certain production or manufacturing processes (e.g., mining, metallurgy, semiconductor manufacturing, pharmaceutical processing, etc.), the tolerance for impurities may be very strict, for example, about parts per billion. In semiconductor wafer processing, testing wafers for impurities (such as metallic impurities) that may be attributed to reduced carrier lifetime, dielectric breakdown of wafer components, and the like, can degrade wafer capabilities or render the wafer inoperable.

[0020] Vapor phase decomposition (VPD) and subsequent scanning of wafers are techniques used to analyze the composition of wafers to determine the presence of metallic impurities. Conventional VPD and scanning techniques have limited processing capabilities for facilitating the processing and scanning of silicon wafers for impurity analysis. For example, systems typically utilize separate chambers for VPD and scanning procedures. In the VPD chamber, silicon dioxide and other metallic impurities present on the surface are contacted with a vapor (e.g., hydrofluoric acid (HF), hydrogen peroxide (H₂O₂), or combinations thereof) and removed from the surface as vapor (e.g., as silicon tetrafluoride (SiF₄)). The processed wafer is transported to a separate chamber for scanning, in which a droplet is introduced onto the surface of the processed wafer to collect residues after the decomposition vapor reacts with the wafer. The scanning procedure may involve holding a droplet on the surface of the wafer with a scanning head and rotating the wafer while moving the scanning head or keeping the scanning head stationary to allow the droplet to move above the surface. After multiple rotations of the wafer, droplets interact with the desired surface area of ​​the wafer to absorb any residue from the contact surface after decomposition. However, conventional wafer handling technologies require significant time and equipment to process a single wafer, such as by moving the wafer from a decomposition chamber to a scanning chamber and then to a rinsing chamber during processing, using scanning nozzles that have limited droplet interaction with the wafer surface during scanning (i.e., requiring multiple rotations of the wafer for the droplets to interact with the entire surface area or a portion thereof), and similar methods. Furthermore, this wafer handling may potentially expose technicians or other individuals to toxic hydrofluoric acid, or may increase the risk of environmental contamination of the wafer during transfer between processing chambers, requiring a large physical floor footprint to facilitate equipment and transfer mechanisms between equipment.

[0021] Scanning systems used for analyzing wafers and other structures typically rely on the amount of fluid introduced onto the surface of a material, which is analyzed to calculate the composition of the contents of a sample removed from the surface. If the assumed amount of fluid introduced onto the surface differs from the actual amount introduced, errors can be introduced into the calculation of the material removed from the surface (e.g., via concentration analysis). Furthermore, if the amount of fluid removed from the surface after a scan differs from the amount introduced to the surface to perform the scan, the surface may contain residual fluid that was not removed. This may require additional cleaning and handling operations, potentially causing errors during the determination of the contents of the material removed from the surface via fluid, or similar issues. A system using a single liquid detector can estimate the volume of a liquid segment flowing through a fluid line by measuring the time the liquid detector detects fluid. For the estimation to be accurate, the estimation relies on a known and constant flow rate. However, in real-life fluid transport scenarios, the flow rate is rarely constant and can vary greatly between samples for various reasons, including but not limited to different liquid viscosities, impurities in the transport pipeline, pump inaccuracies, ambient temperature, and the like.

[0022] Therefore, the present invention relates at least in part to a system and method for determining the flow characteristics of a fluid segment of a fluid delivery line to measure or otherwise calculate the volumetric flow rate and volume of a liquid present in the fluid segment. A system may include a fluid delivery line having at least two fluid sensors configured to measure the fluid flow through the fluid delivery line by detecting gas / liquid interfaces in the fluid delivery line and monitoring the time intervals between different gas / liquid interfaces. For example, the fluid sensors may measure the presence or absence of liquid or gas to distinguish between liquid and gas in the fluid delivery line. Exemplary fluid sensors include, but are not limited to, optical sensors, pressure sensors, ultrasonic transducers, conductivity sensors, or combinations thereof.

[0023] Fluid sensors are positioned such that there is a gap between the fluid sensors having a known volume, distance, or a combination thereof. As a segment of fluid travels between the two fluid sensors, the flow rate of the fluid within that segment is determined by measuring the time period during which the liquid travels from the first fluid sensor to the second fluid sensor, and by dividing the volume of the gap between the two fluid sensors by that time period. The system can determine multiple flow rates for a given fluid segment to provide, for example, an average flow rate for the fluid segment. For example, an initial flow rate of the fluid segment can be determined based on measuring the front end of a liquid portion of the sample as it travels from the first fluid sensor until it is detected by the second fluid sensor, and an end flow rate of the fluid segment can be determined based on measuring the rear end of the liquid portion of the sample as it travels from the first fluid sensor until it is detected by the second fluid sensor. The volume of the liquid portion can be determined by dividing the total time the fluid sensors sense the sample segment by the flow rate (e.g., average flow rate) measured by the system. In this implementation, the system determines the volume of the air gap in the delivery pipeline by monitoring the absence of a liquid portion in the fluid section and calculating the air gap volume in the same manner as calculating the volume of the liquid portion. The volume of the air gap can be subtracted from the volume of the fluid sample to provide a liquid volume determination or enhance its accuracy. (Exemplary implementation)

[0024] Figures 1 to 8 illustrate various embodiments of a system ("System 100") for determining the volume of a liquid sample flowing through a fluid delivery line according to various embodiments of the present invention. System 100 generally includes a fluid sensor system 102, a timer 104, and a controller 106 configured to monitor the fluid flow through a fluid delivery line 108 of a sample analysis system for volume determination. For example, System 100 can determine the volume of a liquid sample delivered to or through an analysis system, including but not limited to vapor deposition and wafer scanning systems (e.g., an example described with reference to Figures 3 to 5), analytical sample preparation systems configured to introduce one or more fluids into a sample fluid (e.g., diluent, standard, reactant, or other fluid) for content analysis, sample delivery systems configured to deliver liquid samples from a remote sampling station to the analysis system (e.g., having staggered gas sections), and the like.

[0025] The fluid sensor system 102 includes a plurality of sensors configured to detect the presence and absence of liquid in a fluid flowing through the fluid delivery line 108, and generate one or more sensing signals accordingly. Alternatively or additionally, the plurality of sensors of the fluid sensor system 102 may detect the presence and absence of gas in the fluid flowing through the fluid delivery line 108, such as gas segments before or after a liquid sample segment in the fluid delivery line 108 or air bubbles present in the fluid delivery line 108, and generate one or more sensing signals accordingly. The output from the fluid sensor system 102 (e.g., sensing signals in response to the presence or absence of liquid or gas) may be transmitted or otherwise made available to the controller 106 for processing (e.g., via one or more memory devices). System 100 can monitor the timing of the activity of fluid sensor system 102 via timer 104, wherein the output from timer 104 can be transmitted or otherwise made available to controller 106 for processing. For example, controller 106 can access the outputs from fluid sensor system 102 and timer 104 to perform calculations relating to the volumetric flow rate and volume of the fluid flowing through fluid delivery line 108. Controller 106 may be a dedicated controller for system 100, may be integrated or associated with one or more components of system 100, may be associated with a device remotely connected to the system, or may be associated with or integrated with a combination of system and / or devices.

[0026] Referring to FIG1, the fluid sensor system 102 shown includes a first liquid sensor 110 and a second liquid sensor 112 for detecting the presence and absence of liquid in a fluid flowing through a fluid delivery line 108. The exemplary operation of the first liquid sensor 110 and the second liquid sensor 112 is further described herein with reference to FIGS. 2A to 2D. Although FIG1 shows two liquid sensors (first liquid sensor 110, second liquid sensor 112), the fluid sensor system 102 is not limited to two sensors or two liquid sensors, and may include two or more sensors, two or more liquid sensors, two gas sensors, two or more gas sensors, at least one gas sensor and at least one liquid sensor, or similar combinations thereof. In the implementation scheme, one or more of the first liquid sensor 110 and the second liquid sensor 112 include an optical sensor, a pressure sensor, an ultrasonic transducer, a conductivity sensor or similar combinations thereof, to detect the presence or absence of liquid in the fluid flowing through the fluid delivery line 108.

[0027] Referring to Figures 2A to 2D, an exemplary operation of the first liquid sensor 110 and the second liquid sensor 112 is described to provide data for determining the volumetric flow rate and volume of a liquid sample segment 200 present in a fluid flowing through a fluid delivery line 108. At a first time (t0), as shown in Figure 2A, the liquid sample segment 200 is delivered through the fluid delivery line 108 until the first liquid sensor 110 detects a tip 202 of the liquid sample segment 200. The tip 202 represents the transition from gas (e.g., a gaseous void or bubble in the fluid delivery line 108) to liquid at the beginning of the flow of the liquid sample segment 200. Subsequently, the first liquid sensor 110 provides an output indicating detection (e.g., a sensing signal), which can be used by the controller 106 (e.g., via storage, transmission, or the like). Timer 104 provides the time at which the first liquid sensor 110 detects the front end 202, and makes that time available to controller 106 (e.g., via storage, transmission, or the like). Detection of the front end 202 of the liquid sample segment 200 provides an indication that a liquid segment is now flowing past the first liquid sensor 110 and is approaching the second liquid sensor 112, located downstream of the first liquid sensor 110, via fluid delivery line 108.

[0028] At a second time (t1), as shown in FIG2B, the liquid sample segment 200 is conveyed through the fluid delivery line 108 until the second liquid sensor 112 detects the front end 202 of the liquid sample segment 200. The front end 202 of the liquid sample segment 200 travels a distance of a gap 204 between the first liquid sensor 110 and the second liquid sensor 112 during the duration from the first time to the second time. The gap 204 may be a known distance, or it may have a known volume within the fluid delivery line 108 within the distance of the gap 204 to provide a first measurement of the flow rate of the liquid sample segment 200. For example, using a known distance, the varying dimensions of the fluid delivery line 108 can simultaneously provide an accurate volume of the fluid delivery line 108 relative to the gap 204, while using a configured fluid delivery line 108, the volume of the fluid delivery line 108 relative to the gap 204 can remain constant. Next, the second liquid sensor 112 provides an output indicating detection (e.g., a sensing signal), which is available to the controller 106 (e.g., via storage, transmission, or the like). The timer 104 provides the time at which the second liquid sensor 112 detects the front end 202, and makes that time available to the controller 106 (e.g., via storage, transmission, or the like). Then, the controller 106 or another part of the system 100 can determine a first volumetric flow rate of the liquid sample segment 200 via equation (1): (1) First volumetric flow rate = where the fixed volume is the volume of the fluid delivery line 108 of the gap 204, t1 is the time provided by the timer 104 when the second liquid sensor 112 detects the front end 202 of the liquid sample segment 200, and t0 is the time provided by the timer 104 when the first liquid sensor 110 detects the front end 202 of the liquid sample segment 200.

[0029] At a third time (t2), as shown in FIG2C, a liquid sample segment 200 is conveyed through a fluid delivery line 108 until a first liquid sensor 110 detects a rear end 206 of the liquid sample segment 200. The rear end 206 represents a transition from liquid in the liquid sample segment 200 back to gas (e.g., a gaseous void or bubble in the fluid delivery line 108), indicating the end of the liquid sample segment 200 within the fluid delivery line 108 or a bubble that divides the liquid sample segment 200 into multiple fluid sample portions. The first liquid sensor 110 then provides an output indicating detection (e.g., a sensing signal), which is available to the controller 106 (e.g., via storage, transmission, or the like). A timer 104 provides the time at which the first liquid sensor 110 detects the rear end 206 and makes that time available to the controller 106 (e.g., via storage, transmission, or the like). The detection of the downstream end 206 of the liquid sample segment 200 provides an indication that the end of the liquid sample segment 200 is now flowing through the first liquid sensor 110 and is approaching the second liquid sensor 112.

[0030] At a fourth time (t3), as shown in FIG2D, the liquid sample segment 200 is conveyed through the fluid delivery line 108 until the downstream end 206 of the liquid sample segment 200 is detected by the second liquid sensor 112 after passing through the gap 204. The second liquid sensor 112 then provides an output indicating detection (e.g., a sensing signal), which is available to the controller 106 (e.g., via storage, transmission, or the like). A timer 104 provides the time at which the downstream end 206 is detected by the second liquid sensor 112 and makes that time available to the controller 106 (e.g., via storage, transmission, or the like). Next, the controller 106 or another part of the system 100 can determine the second volume flow rate of one of the liquid sample segments 200 via equation (2): (2) Second volume flow rate = where the fixed volume is the volume of the fluid delivery line 108 of the gap 204, t3 is the time provided by the timer 104 when the second liquid sensor 112 detects the rear end 206 of the liquid sample segment 200, and t2 is the time provided by the timer 104 when the first liquid sensor 110 detects the rear end 206 of the liquid sample segment 200.

[0031] The average volumetric flow rate of one of the liquid sample segments 200 can be calculated via equation (3): (3) Average volumetric flow rate = Average volumetric flow rate. This takes into account the actual fluid flow conditions of the liquid sample segment 200 through the fluid delivery line 108 and can detect the difference in volumetric flow rate between different samples delivered through the system. In an implementation, an additional liquid sensor may be included to measure additional parameters of the liquid sample segment 200 traveling through the fluid delivery line 108 to provide additional measurement of volumetric flow rate.

[0032] The volume of liquid sample segment 200 can be calculated using equation (4): (4) Volume =

[0033] As described herein, system 100 can be used in conjunction with a semiconductor wafer processing system to determine the volume of liquid introduced onto the surface of a wafer via a scanning nozzle, to determine the volume of liquid removed from the surface of the wafer via the scanning nozzle, and to compare the introduced liquid volume with the removed liquid volume to determine whether residual fluid remains on the wafer, whether substantial evaporation of fluid occurs on the wafer, or a combination thereof. An exemplary wafer processing system 300 is shown in Figures 3 to 5, comprising a chamber 302 and a scanning arm assembly 304 supporting a fluid handling system, and a motor system that facilitates at least a decomposition and scanning process of wafer 308 (sometimes referred to herein as "wafer") by introducing decomposition fluid into the wafer and by introducing scanning fluid into and removing scanning fluid from one or more surfaces of a semiconductor wafer 308. Chamber 302 provides an environment for wafer decomposition and wafer scanning within a single chamber area, and includes a wafer support 310 for holding a wafer 308, and a motor system for controlling the vertical position of the wafer support 310 relative to chamber 302 (e.g., within chamber 302, above chamber 302, etc.) to position the wafer 308 for decomposition and scanning procedures or during other procedures of system 100 (e.g., rinsing, etc.). The motor system additionally provides rotational control of the wafer support 310 to rotate the wafer 308 during various procedures of system 300, and provides rotational and vertical control of the scan arm assembly 304 to bring a nozzle 404 of the scan arm assembly 304 into a position above the wafer 308 (e.g., as shown in FIG. 5) and into a position in a rinsing station 314 for nozzle cleaning during scanning procedures. In one embodiment, the wafer support 310 includes a vacuum stage to hold the wafer 308 in place, such as during movement of the wafer support 310 relative to the wafer support 310.

[0034] Chamber 302 includes a chamber body 316 that defines an internal region 318 for receiving a wafer 308 for processing. During an exemplary operation shown in FIG3, system 300 may receive a semiconductor wafer 308 or another material onto wafer support 310, such as by an automated arm 50 selecting a wafer 308 from a front-end wafer pod (FOUP) or other location and introducing the selected wafer 308 onto wafer support 310 (e.g., centered on wafer support 310). A motor system may position wafer support 310 at, above, or near the top of chamber body 316 to allow automated arm 50 to pick up wafer support 310 and place wafer 308 onto wafer support 310. For example, during loading of wafer 308, wafer support 310 may be positioned adjacent to an opening 326 at the top of chamber 302.

[0035] System 300 may include a cover 330 to isolate an inner region 318 from an outer region 332 to facilitate wafer decomposition while limiting exposure of decomposition fluid to the outer region 332. For example, cover 330 may have a size and shape that covers opening 326 when positioned over opening 326. Cover 330 may be positioned between an open position (e.g., shown in FIG. 3) and a closed position (e.g., shown in FIG. 4). The open position may be used to provide access to the automated arm 50 during wafer loading, during scanning procedures, during wafer unloading procedures, and the like. In an embodiment, cover 330 is in the open position when wafer support 310 is in a first position adjacent to opening 326 to provide access to wafer 308 by nozzles of scanning arm assembly 304. The closed position may be used during wafer decomposition procedures to prevent decomposition fluid from leaving chamber 302 through opening 326. In one embodiment, at least a portion of the cover 330 contacts the chamber body 316 to isolate the inner region 318 from the outer region 332. The wafer 308 moves to a second position within the inner region 318 via control of the vertical position of the wafer support 310 by a motor system and via rotational control of the motor system.

[0036] After the wafer 308 is introduced into the wafer support 310, the system 300 can be configured to facilitate the decomposition of one or more surfaces or edges of the wafer 308. In an embodiment, the chamber 302 includes an atomizer or other outlet positioned in the chamber body 316 to spray a decomposition fluid onto the surface of the wafer 308 when the wafer support 310 is in a second position (e.g., shown in FIG. 4). The decomposition fluid can be sprayed directly into the chamber 302 by the atomizer.

[0037] After the wafer 308 is disassembled, the system 300 can be switched to a scanning configuration to allow the scan arm assembly 304 to engage one or more surfaces of the wafer 308 without transferring the wafer 308 to a separate scanning system. To switch to the scanning configuration, the motor system may position the wafer support 310 adjacent to the opening 326 or otherwise closer to the top of one of the chamber bodies 316 to allow the scan arm assembly 304 to engage the surfaces of the wafer 308. The scan arm assembly 304 generally includes a rotatable arm support 400 coupled to a nozzle housing 402, the rotatable arm support 400 supporting a nozzle 404 configured to introduce and recover scanning fluid from the surfaces of the wafer 308. For example, the scanning fluid may contain, but is not limited to, one or more acids (e.g., hydrofluoric acid, phosphoric acid, nitric acid, etc.) that, after being configured to dissolve or otherwise transport and decompose, impurities present on the surface of wafer 308.

[0038] The motor system can control the rotation of the rotatable arm support 400, the vertical positioning of the rotatable arm support 400, or combinations thereof, to position the nozzle housing 402 and the nozzle 404 from one or more locations at the rinsing station 314 to one or more locations adjacent to or above the wafer 308 (e.g., shown in FIG. 5). In an embodiment, the rotatable arm support 400 causes the nozzle 404 to rotate or otherwise move to position the nozzle 404 adjacent to the wafer 308 when the wafer support 310 is positioned at the top of the chamber 302, and to position the nozzle 404 outside one of the paths of the cover 330 from the open position to the closed position when the wafer support 310 is positioned inside one of the chambers 302 (e.g., during decomposition). When the nozzle 404 is located adjacent to or above the wafer 308 (e.g., shown in FIG5), the fluid handling system can control the introduction of scanning fluid into and from the nozzle 404 to facilitate the scanning procedure on the surface of the wafer 308.

[0039] In one embodiment (an example is shown in FIG. 6), system 100 is included between nozzle 404 and a fluid source 600 for supplying fluid (e.g., decomposition fluid, rinsing fluid, etc.) to wafer 308 via nozzle 404 to determine a volume of fluid introduced into wafer 308 via nozzle 404. Alternatively or additionally, system 100 may be included between nozzle 404 and a sample analysis system 602 (e.g., an ICP analysis system, etc.) to determine a volume of fluid removed from wafer 308 via nozzle 404. In one embodiment, system 100 compares the volume of fluid introduced into wafer 308 via nozzle 404 with the volume of fluid removed from wafer 308 via nozzle 404 to determine an amount of residual liquid retained on wafer 308, an amount of liquid evaporated between application to wafer 308 and recovery from wafer 308, or a combination thereof.

[0040] Figure 7 illustrates an exemplary operation 700 of system 100 for determining, during a decomposition or rinsing process, whether or how much fluid remains on wafer 308 after fluid recovery. Operation 700 includes, in block 702, delivering fluid from a fluid source to a nozzle of a wafer processing system. For example, fluid from fluid source 600 may be delivered from fluid source 600 to nozzle 404 via a pump, vacuum source, or the like. The fluid may include, for example, a scanning fluid configured to dissolve or otherwise transport impurities present on the surface of wafer 308 after decomposition (e.g., vapor phase decomposition) on the wafer surface. Operation 700 also includes, in block 704, determining a volume of fluid delivered to the nozzle. For example, a first liquid volume determination system 100 may use a first fluid sensor 110 and a second fluid sensor 112 located in the fluid delivery line between the fluid source 600 and the nozzle 404 to detect the fluid flow between the fluid source 600 and the nozzle 404 (e.g., as shown in FIG. 6) and calculate the volume as described herein.

[0041] Operation 700 is also included in block 706, which involves dispensing fluid received from a fluid source onto the wafer. For example, system 100 may introduce fluid received from fluid source 600 onto wafer 308 via nozzle 404 through the action of a pump, vacuum source, or the like. In one embodiment, fluid is introduced onto wafer 308 via nozzle 404 during the rotation of wafer 308 to scan the surface of wafer 308, wherein nozzle 404 maintains the fluid in controlled contact with the surface to dissolve or otherwise transport impurities present on the surface of wafer 308 during the scanning operation. In one embodiment, all or substantially all volume of fluid received from fluid source 600 is introduced into wafer 308 via nozzle 404 such that the volume of fluid detected by first liquid volume determination system 100 is the volume of fluid introduced into wafer 308. Operation 700 is also included in block 708, which involves recovering fluid from the wafer. For example, fluid on the surface of wafer 308 can be drawn back into nozzle 404 by the action of a pump, vacuum source, or similar means. In an embodiment, nozzle 404 controls the movement of fluid from the surface to prevent fluid flow breakage and thus prevent a large amount of fluid from remaining on the surface of wafer 308. However, conditions on wafer 308 (e.g., inconsistent hydrophobicity, temperature gradients, surface defects, etc.) may cause some fluid to remain on the surface, evaporate from the surface, overflow from the surface, or otherwise not be drawn from the surface by nozzle 404. In these examples, determining whether nozzle 404 has recovered a sufficient amount of fluid provides an indication of whether a large amount of fluid is remaining on the surface or otherwise lost.

[0042] Operation 700 is also included in block 710, determining a volume of fluid recovered from the nozzle. For example, a second liquid volume determination system 100 may use a first fluid sensor 110 and a second fluid sensor 112 located on a fluid delivery line adjacent to the nozzle 404 and a sample analysis system 602 to detect the fluid flow between the nozzle 404 and the sample analysis system 602 (e.g., as shown in FIG. 6), and may calculate the volume as described herein.

[0043] Operation 700 is further included in block 712, determining whether the fluid recovered from the wafer via the nozzle is within a critical limit. For example, the controller 106 and / or other parts of system 100 may compare the volume of fluid recovered from wafer 308 via nozzle 404 (e.g., as measured by a second liquid volume determination system 100) with the volume of fluid introduced into wafer 308 via nozzle 404 (e.g., as measured by a first liquid volume determination system 100). If the recovered volume is significantly different from the introduced volume, system 100 may determine that an erroneous sampling operation has occurred. For example, excess fluid may remain on wafer 308, excess fluid may have evaporated from wafer 308, fluid may have overflowed from the wafer surface, or similar. In an embodiment, if the recovered volume is less than about 70% of the introduced volume, the volume difference may be considered a significant difference. For example, a volume difference may be considered significant if the recovered volume is less than about 80% of the introduced volume, a volume difference may be considered significant if the recovered volume is less than about 85% of the introduced volume, a volume difference may be considered significant if the recovered volume is less than about 90% of the introduced volume, a volume difference may be considered significant if the recovered volume is less than about 95% of the introduced volume, a volume difference may be considered significant if the recovered volume is less than about 99% of the introduced volume, or similar. Although the threshold amount has been described by comparing the volume of the administered volume with the volume of the recovered volume, system 100 is not limited to these threshold values. For example, in embodiments, system 100 may include alternative or additional threshold values ​​based on a specific volume or a minimum volume. For example, system 100 may determine whether the recovered volume is within a specific range of a specific volume (e.g., within ±5% of 500 μL) or meets or exceeds a minimum volume (e.g., at least 500 μL). Different threshold values, values, or both may be used without departing from the scope of the invention.

[0044] If, in block 712, the fluid recovered from the wafer via the nozzle is within a critical limit, operation 700 proceeds to block 714, whereby the fluid is delivered to an analytical system. For example, if at least 70%, 80%, 85%, 90%, 95%, 99%, or similar volumes of the fluid initially introduced into wafer 308 from the flow system recovered from wafer 308 via nozzle 404 are present, system 100 may deliver the fluid to sample analysis system 602 for quantitative determination of one or more chemical species present in the fluid, such as by analyzing the fluid using an ICP spectrometer. In an embodiment, the fluid recovered from wafer 308 is held in a delivery line, holding loop, or similar until system 100 determines that the recovered amount is within a critical limit. Subsequently, after determining that a sufficient amount of fluid is present, system 100 may automatically engage a pump system, automatically switch a valve, or a combination thereof, to direct the fluid to sample analysis system 602. In an implementation, if the fluid recovered from the wafer via the nozzle is within a certain limit, the system 100 can provide an indication that the nozzle 404 has successfully removed a sample from the wafer 308, such as by generating an output signal associated with a successful scan operation.

[0045] If, in block 712, the fluid recovered from the wafer via the nozzle is not within the critical limit, operation 700 proceeds to block 716, where the system generates an alarm. For example, if the fluid recovered from the wafer 308 via nozzle 404 is not at least 70%, 80%, 85%, 90%, 95%, 99%, or similar of the volume of fluid initially introduced into the wafer 308, the system 100 determines that the amount of fluid recovered from the surface of the wafer 308 is insufficient and generates a signal, communication, or both indicating that sufficient fluid volume has not been recovered. In an embodiment, the system 100 may receive user input via a user interface to continue delivering the insufficient amount of fluid to the sample analysis system 602 or to send the fluid to waste. Alternatively, the system 100 may process the sample using the sample analysis system 602 and provide an indication that the analysis results are associated with insufficient fluid volume, a failed fluid recovery, or the like. In one implementation, the fluid recovered from wafer 308 is held in a delivery line, holding loop, or similar until system 100 determines that the recovered amount is outside a critical limit. System 100 may then automatically engage a pump system, automatically switch a valve, or a combination thereof to direct the fluid to waste or otherwise utilize an alarm-guided sample analysis system 602 associated with insufficient fluid volume.

[0046] In one embodiment, the fluid sensor system 102 can be used to track the advance of an air gap in a liquid sample segment 200 present in the fluid delivery line 108 by monitoring the time between the end of a first liquid portion in the fluid delivery line at gap 204 and the beginning of a next liquid portion. The system 102 can then determine the volume of the air gap based on the volumetric flow rate of the air gap and subtract the volume of the air gap from the volume of the liquid sample segment 200. For example, referring to FIG8, a fluid delivery line 108 is shown, wherein the liquid sample segment 200 breaks into individual fluid segments 800, 802, 804, 806, 808, and 810 having intermediate air gaps 812, 814, 816, 818, and 820. The system 100 uses a first fluid sensor 110 and a second fluid sensor 112 to detect the presence or absence of the individual fluid segments and intermediate air gaps, wherein the volumes of the individual fluid segments and intermediate air gaps can be calculated as described herein. System 100 can store (e.g., in computer memory, remote server, etc.) data associated with individual fluid segments and intermediate air gaps, including but not limited to the timing of presence / absence detection, volume, flow rate, and combinations thereof.

[0047] Next, the system 100 can determine the volume of the liquid sample segment 200 by adding the volumes of the individual fluid segments 800, 802, 804, 806, 808, and 810. Data associated with the volumes of the intermediate air gaps 812, 814, 816, 818, and 820 can be excluded because including these volumes would lead to incorrect concentration calculations from the sample analysis system 602. For example, if the air gaps are included, the concentration calculation would assume that the sample volume is larger than the actual volume. In an embodiment, the system can determine the volume of the liquid sample segment 200 by calculating the volume based on the leading or trailing surface of the fluid segment 800 and the trailing or trailing surface of the fluid segment 810, and by subtracting the calculated volumes of the intermediate air gaps 812, 814, 816, 818, and 820.

[0048] Electromechanical devices (e.g., electric motors, servo devices, actuators, or the like) may be coupled to or embedded within components of a system (e.g., system 100 and / or system 300) to facilitate automated operation via control logic embedded within or externally driving the system. The electromechanical devices may be configured to cause movement of devices and fluids according to various programs (such as those described herein). The system may include or be controlled by a computing system having a processor or other controller configured to execute computer-readable program instructions (i.e., control logic) from a non-transitory carrier medium (e.g., storage media, such as a flash drive, hard drive, solid-state drive, SD card, optical disc, or the like). The computing system may be connected to various components of the system via direct connection or through one or more network connections (e.g., local area network (LAN), wireless local area network (WAN or WLAN), one or more hub connections (e.g., USB hubs), etc.). For example, the computing system may be communicatively coupled to fluid sensors, timers, chambers, motor systems, valves described herein, pumps described herein, other components described herein, control components that guide them, or combinations thereof. When executed by a processor or other controller, program instructions may cause the computing system to control a system (e.g., control a pump, selector valve, actuator, spray nozzle, positioning device, etc.) according to one or more operating modes as described herein.

[0049] It should be understood that the various functions, control operations, processing blocks, or steps described throughout this invention may be implemented by any combination of hardware, software, or firmware. In some embodiments, the various steps or functions are implemented by one or more of the following: electronic circuits, logic gates, multiplexers, a programmable logic device, an application-specific integrated circuit (ASIC), a controller / microcontroller, or a computing system. A computing system may include, but is not limited to, a human computing system, a mobile computing device, a host computing system, a workstation, a video computer, a parallel processor, or any other device known in the art. Generally, the term "computing system" is broadly defined to encompass any device having one or more processors or other controllers that execute instructions from a carrier medium.

[0050] Program instructions for implementing functions, controlling operations, processing blocks, or steps (such as those shown in the embodiments described herein) may be transmitted via or stored on a carrier medium. The carrier medium may be a transmission medium, such as, but not limited to, a wire, cable, or wireless transmission link. The carrier medium may also include a non-transitory signal-bearing medium or storage medium, such as, but not limited to, a read-only memory, a random access memory, a magnetic disk or optical disk, a solid-state or flash memory device, or a magnetic tape.

[0051] Furthermore, it should be understood that the present invention is defined by the scope of the appended invention application. Although embodiments of the invention have been illustrated, it should be understood that those skilled in the art can make various modifications without departing from the scope and spirit of the invention. [Simplified Explanation of the Diagram]

[0006] Refer to the accompanying drawings for description [Implementation]. The use of the same element symbols in different examples in the description and drawings may indicate similar or identical items.

[0007] Figure 1 is a schematic illustration of a system for determining the volume of a liquid sample flowing through a fluid delivery pipeline according to an embodiment of the present invention.

[0008] Figure 2A is a schematic illustration of a liquid volume determination system according to an embodiment of the present invention, wherein a first liquid sensor detects the presence of a liquid segment flowing through a fluid delivery pipeline at a first time.

[0009] Figure 2B is a schematic illustration of one of the liquid volume determination systems in Figure 2A, wherein a second liquid sensor detects the presence of a liquid segment flowing through the fluid delivery pipeline at a second time.

[0010] Figure 2C is a schematic illustration of one of the liquid volume determination systems in Figure 2A, wherein a first liquid sensor detects the presence of liquid flowing through the downstream end of a fluid delivery pipeline at a third time.

[0011] Figure 2D is a schematic illustration of one of the liquid volume determination systems in Figure 2A, wherein a second liquid sensor detects the presence of liquid flowing through the downstream end of a fluid delivery pipeline at a fourth time.

[0012] FIG3 is an isometric view of a system for integration decomposition and scanning of a semiconductor wafer according to an embodiment of the present invention.

[0013] Figure 4 is an isometric view of the system in Figure 3, wherein a semiconductor wafer is positioned in a cavity.

[0014] Figure 5 is an isometric view of the system in Figure 3, wherein a scanning arm positions a nozzle above a surface of a semiconductor wafer.

[0015] Figure 6 is a schematic illustration of a system for determining the volume of a liquid sample in a wafer scanning and analysis system according to an embodiment of the present invention.

[0016] Figure 7 is a flowchart of one of the operations for determining whether fluid remains on a wafer surface after being recovered by a scanning nozzle, according to an embodiment of the present invention.

[0017] Figure 8 is a schematic illustration of a liquid volume determination system according to an embodiment of the present invention, wherein the volumes of liquid and gas segments are determined individually.

Claims

1. A system for determining whether liquid remains on a wafer surface after a scanning operation, comprising: A first liquid volume determination system is configured to be positioned adjacent to a first fluid delivery line, the first fluid delivery line being in fluid communication with a scanning nozzle, the scanning nozzle being configured to dispense a fluid onto a wafer surface and recover the fluid from the wafer surface for delivery to an analysis system, the first liquid volume determination system being configured to detect a gas / liquid transition of the fluid flowing through the first fluid delivery line and to determine a volume of the liquid sample dispensed onto the wafer surface; A second liquid volume determination system configured to be positioned adjacent to a second fluid delivery line downstream of the scanning nozzle and the first liquid volume determination system, the second liquid volume determination system being configured to detect a gas / liquid transition of the fluid flowing through the second fluid delivery line and determine a volume of a liquid sample recovered from the wafer surface; and a controller configured to compare the volume of the liquid sample recovered from the wafer surface with the volume of the liquid sample applied to the wafer surface, and to generate an alarm if the volume of the liquid sample recovered from the wafer surface is not within a critical limit compared to the volume of the liquid sample applied to the wafer surface.

2. The system of claim 1, wherein the first liquid volume determination system includes a first sensor configured for positioning adjacent to the first fluid delivery line, and a second sensor configured for positioning adjacent to the first fluid delivery line downstream of the first sensor at a gap.

3. The system of claim 2, wherein at least one of the first sensor and the second sensor comprises at least one of an optical sensor, a pressure sensor, an ultrasonic transducer, and a conductivity sensor.

4. The system of claim 2, further comprising a timer configured to measure a first time when the gas / liquid transition of the fluid flows through the first fluid delivery line and passes the first sensor, and a second time when the gas / liquid transition of the fluid flows through the first fluid delivery line and passes the second sensor.

5. The system of claim 4, wherein the controller is configured to determine a first volume flow rate based on at least one of the first time, the second time, and a distance or volume associated with the gap.

6. The system of claim 5, wherein the timer is configured to measure a third time when a second gas / liquid transition of fluid flows through the first fluid delivery line and passes the first sensor, and a fourth time when the second gas / liquid transition of fluid flows through the first fluid delivery line and passes the second sensor.

7. The system of claim 6, wherein the controller is configured to determine a second volume flow rate based on at least one of the third time, the fourth time, and a distance or volume associated with the gap.

8. The system of claim 7, wherein the controller is configured to determine the volume of the liquid sample applied to the wafer surface based on an average of the second volume flow rate, the first volume flow rate, and a duration between the first time and the third time.

9. The system of claim 5, wherein the second liquid volume determination system includes a third sensor configured for positioning adjacent to the second fluid delivery line, and a fourth sensor configured for positioning adjacent to the second fluid delivery line downstream of the third sensor at a second gap.

10. The system of claim 9, wherein at least one of the timer or a second timer is configured to measure a third time when a third gas / liquid transition of fluid flows through the second fluid delivery line and passes through the third sensor, and a fourth time when a fourth gas / liquid transition of fluid flows through the second fluid delivery line and passes through the fourth sensor.

11. The system of claim 10, wherein at least one of the controller or a second controller is configured to determine a second volume flow rate based on at least one of the third time, the fourth time, and a distance or volume associated with the second gap.

12. The system of claim 1, wherein the limit quantity is at least about 70 units of volume.

13. A method for determining whether liquid remains on a wafer surface after a scanning operation, comprising: A fluid sample is delivered from a fluid source to a scanning nozzle of a wafer processing system via a fluid delivery line; the fluid sample is applied to a wafer surface using the scanning nozzle; a first liquid volume determination system located downstream of the fluid source and upstream of the scanning nozzle determines the volume of the liquid sample applied to the wafer surface; the fluid sample is recovered from the wafer surface using the scanning nozzle; a second liquid volume determination system located downstream of the scanning nozzle determines the volume of the liquid sample recovered from the wafer surface; a controller communicatively coupled to the first and second liquid volume determination systems compares the volume of the liquid sample recovered from the wafer surface with the volume of the liquid sample applied to the wafer surface; and if the volume of the liquid sample recovered from the wafer surface is significantly smaller than the volume of the liquid sample applied to the wafer surface, an alarm is generated.

14. The method of claim 13, wherein if the volume of the liquid sample recovered from the wafer surface is less than about 70% of the volume of the liquid sample applied to the wafer surface, then the volume of the liquid sample recovered from the wafer surface is significantly less than the volume of the liquid sample applied to the wafer surface.

15. The method of claim 13, wherein if the volume of the liquid sample recovered from the wafer surface is less than about 90% of the volume of the liquid sample applied to the wafer surface, then the volume of the liquid sample recovered from the wafer surface is significantly less than the volume of the liquid sample applied to the wafer surface.

16. The method of claim 13, wherein if the volume of the liquid sample recovered from the wafer surface is less than about 95% of the volume of the liquid sample applied to the wafer surface, then the volume of the liquid sample recovered from the wafer surface is significantly less than the volume of the liquid sample applied to the wafer surface.

17. The method of claim 13, further comprising conveying the fluid sample recovered from the wafer surface by the nozzle to an analytical system configured to determine a quantitative quantity of one or more chemical species in the fluid sample.

18. The method of claim 13, further comprising, when it is determined that the volume of the liquid sample recovered from the wafer surface is not significantly smaller than the volume of the liquid sample applied to the wafer surface, automatically delivering the fluid sample recovered from the wafer surface by the nozzle to an analysis system configured to determine the quantitative quantity of one or more chemical species in the fluid sample.

19. The method of claim 13, wherein the first liquid volume determination system comprises: a first sensor configured to be located adjacent to the fluid delivery line to detect a time during which a gas / liquid transition passes through the first sensor; and a second sensor configured to be located adjacent to the fluid delivery line downstream of the first sensor at a gap to detect a time during which a gas / liquid transition passes through the second sensor.

20. The method of claim 19, further comprising determining a volumetric flow rate of the fluid sample based on at least one of the time a gas / liquid transition passes through the first sensor, the time a gas / liquid transition passes through the second sensor, and a distance or volume associated with the gap.

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