Mass spectrometry is an analysis technique used for the determination of trace impurities (e.g., elemental, organic, or other impurities) in liquid or gaseous samples. Sample introduction systems may be employed to introduce fluid samples into various analysis instrumentations. A sample introduction system can transport an aliquot of liquid sample to a nebulizer that converts the sample into a polydisperse aerosol suitable for ionization in the mass spectrometry instrumentation. For elemental impurities Inductively Coupled Plasma (ICP) ionization sources are used whereas for organic impurities Electrospray, Atmospheric Pressure Chemical Ionization (APCI), or other ionization sources are used. These ionization sources are coupled to a mass spectrometer, such as a Quadrupole mass spectrometer, a Time of Flight mass spectrometer, an Iontrap mass spectrometer, or the like.
Systems and methods are described for systems and methods for integrated decomposition and scanning of a semiconducting wafer for organic and inorganic impurities. In an aspect, a method for scanning a surface of a semiconducting wafer for organic contaminants utilizing a nozzle includes, but is not limited to, positioning a nozzle above a surface of a semiconducting wafer, the semiconducting wafer supported adjacent to or within an interior of a chamber body; introducing a first scan fluid including one or more organic solvents to an inlet port of the nozzle; directing a portion of the first scan fluid onto the surface of the semiconducting wafer to permit interaction between the first scan fluid and one or more organic contaminants present on the surface of the semiconducting wafer; removing the first scan fluid containing at least a portion of the one or more organic contaminants from the surface of the semiconducting wafer via the nozzle; introducing a second scan fluid including one or more organic solvents to the inlet port of the nozzle; directing a portion of the second scan fluid onto the surface of the semiconducting wafer to permit interaction between the second scan fluid and one or more residual organic contaminants present on the surface of the semiconducting wafer following the first scan fluid removal; and removing the second scan fluid containing at least a portion of the one or more residual organic contaminants from the surface of the semiconducting wafer via the nozzle.
In an aspect, a method for scanning a surface of a semiconducting wafer for organic contaminants utilizing a nozzle includes, but is not limited to, positioning a nozzle above a surface of a semiconducting wafer, the semiconducting wafer supported adjacent to or within an interior of a chamber body; introducing a first scan fluid including one or more organic solvents to an inlet port of the nozzle; directing a portion of the first scan fluid onto the surface of the semiconducting wafer to permit interaction between the first scan fluid and one or more organic contaminants present on the surface of the semiconducting wafer; while directing the portion of the first scan fluid onto the surface of the semiconducting wafer, introducing a second portion of the first scan fluid to the nozzle to replenish a volume of the first scan fluid on the surface of the semiconducting wafer; and removing the first scan fluid containing at least a portion of the one or more organic contaminants from the surface of the semiconducting wafer via the nozzle.
In an aspect, a method for scanning a surface of a semiconducting wafer for organic contaminants utilizing a nozzle includes, but is not limited to, positioning a nozzle above a surface of a semiconducting wafer, the semiconducting wafer supported adjacent to or within an interior of a chamber body; introducing a first scan fluid including one or more organic fluids to an inlet port of the nozzle; directing a portion of the first scan fluid onto the surface of the semiconducting wafer to permit interaction between the scan fluid and one or more organic contaminants present on the surface of the semiconducting wafer; and removing the first scan fluid containing at least a portion of the one or more organic contaminants from the surface of the semiconducting wafer via the nozzle.
This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.
The Detailed Description is described with reference to the accompanying figures. The use of the same reference numbers in different instances in the description and the figures may indicate similar or identical items.
Determination of trace elemental concentrations or amounts in a sample can provide an indication of purity of the sample, or an acceptability of the sample for use as a reagent, reactive component, or the like. For instance, in certain production or manufacturing processes (e.g., mining, metallurgy, semiconductor fabrication, pharmaceutical processing, etc.), the tolerances for impurities can be very strict, for example, on the order of fractions of parts per billion. For semiconductor wafer processing, the wafer is tested for impurities, such as metallic impurities, organic impurities or residues, or the like, that can degrade the capabilities of the wafer or render the wafer inoperable. For instance, metallic impurities on the wafer can diminish carrier lifetimes, cause dielectric breakdown of wafer components, and the like, whereas organic impurities can slow silicon dioxide growth, cause unintentional doping, neutralize photo-generated acids, degrade gate-oxide constructs, alter hydrophobicity or hydrophilicity, and the like.
Vapor phase decomposition (VPD) and subsequent scanning of the wafer is a technique to analyze the composition of the wafer to determine whether metallic impurities are present. Traditional VPD and scanning techniques have limited throughput for facilitating the treatment and scanning of silicon wafers for impurity analysis. For instance, systems often utilize separate chambers for the VPD procedure and for the scanning procedure. In the VPD chamber, silicon dioxide and other metallic impurities present at the surface are contacted with a vapor (e.g., hydrofluoric acid (HF), hydrogen peroxide (H2O2), combinations thereof) and removed from the surface as vapor (e.g., as silicon tetrafluoride (SiF4)). The treated wafer is transported to a separate chamber for scanning, where a liquid droplet is introduced to the treated wafer surface to collect residue following reaction of the decomposition vapor with the wafer.
While the VPD techniques can be appropriate for detection and identification of metallic impurities, there are significant restrictions in use of traditional VPD techniques for recovery and identification of organic contaminants or residues present in or on semiconducting wafers that can adversely affect semiconductor processing. For example, decomposition fluids used in traditional VPD techniques can break down organic molecules or otherwise react with the organic molecules to prevent identification of the original contaminants and prevent determination of concentrations of the original contaminants present on the semiconducting wafer. Similarly, certain analysis systems used in VPD systems do not facilitate the recovery and identification of organic contaminants or residues. For instance, inductively-coupled plasma systems used in the identification of metallic impurities can prevent the identification of the arrangement of the elements present in the organic sample, where such arrangement would be used to determine the appropriate identity of the original organic molecule.
Additionally, attempting to use a single scan solution for recovery of organic contaminants can fail to draw all organic impurities present on a semiconducting wafer. For instance, a scan may only collect residues from 80% of all residues present on the semiconducting wafer in one scan, leaving the remainder of the residues on the semiconducting wafer. Inability to collect all resides can be due to the particular makeup of the contaminants (e.g., metallic, organic, etc.), the chemical composition of the scan solution (e.g., polar, non-polar, etc.), whether a decomposition process occurred prior to the scan, or the like. For example, organic molecules can have varying recovery efficiencies relative to other organic molecules where the type of solvent used by the scan nozzle can impact which organic residues are removed from the semiconducting wafer, how much of the organic residue is removed, and which organic residues are retained on the surface. Analysis of the scan would therefore only give partial insight into the total contaminants present, where the remainder of the unknown contaminants could drastically and negatively impact semiconductor fabrication and integration. Attempting to premix scan solutions can provide inaccurate ratios of chemicals due to interaction between the chemicals during storage, due to imprecise transfer methods to mix the chemicals, due to contamination risks during storage and transport, or the like, which in turn can lead to an inability to collect organic contaminants or portions thereof.
Accordingly, the present disclosure is directed, at least in part, to systems and methods for integrated decomposition and scanning of a semiconducting wafer for organic and inorganic impurities. In an aspect, a system can facilitate both semiconductor wafer decomposition and scanning, where a chamber facilitates decomposition and scanning of the semiconducting wafer with a single chamber footprint. Alternatively or additionally, the system can operate without an initial decomposition step, such as to avoid breaking down organic contaminants prior to scanning (e.g., to preserve subsequent identification of the organic contaminants). During scanning, a nozzle directs a stream of fluid along a surface of the semiconducting wafer between a first port of the nozzle and a second port of the nozzle guided by a nozzle hood defining an elongated channel to direct the stream along the wafer surface. Alternative or additional nozzles can be utilized, such as to support scan solutions including organic solvents to collect organic contaminants.
In aspects, the chamber defines at least two apertures through which the semiconducting wafer can pass through operation of a wafer support and associated motor system, with a ledge to provide zones within the chamber for decomposition and rinsing while controlling fluid movement within the chamber, such as for draining and preventing cross contamination. The motor system controls a vertical position of the wafer support with respect to the chamber body to move the semiconductor within the chamber body, with positioning above the chamber body supported by the motor system to load and unload wafers, provide access to the nozzle, and the like. The chamber further incorporates a nebulizer or other spray device to direct decomposition fluid that is aerosolized by the nebulizer directly onto the surface of the semiconducting wafer while the wafer support positions the semiconducting wafer within an interior region of the chamber. A chamber can incorporate a lid that can open and close with respect to the chamber to isolate the interior region of the chamber from the region exterior to the chamber, such as during the decomposition process. The nozzle can be positioned with respect to the chamber by a rotatable scan arm, where the nozzle can be positioned away from the chamber to facilitate lid closure (e.g., during the decomposition procedure) or to facilitate rinsing of the nozzle at a rinse station. Further, the rotatable scan arm can position the nozzle over the semiconducting wafer during the scanning procedure. The system can utilize a fluid handling system including switchable selector valves and pumps to control introduction of fluid to the nozzle, from the surface of the wafer, for preparation of blanks, for rinsing system components, and the like. Following or during the scanning procedure, the scanning fluid can be collected and sent to an analysis device (e.g., ICPMS device) for analytical determination of the composition of the scanning fluid.
In aspects, a scan nozzle can introduce an organic scan solution to one or more surfaces of a semiconducting wafer. The scan nozzle is moved relative to the surface of the semiconducting wafer to draw organic contaminants into the scan solution. The scan solution is recovered from the surface of the semiconducting wafer (e.g., through a pump in fluid communication with the scan nozzle) and transferred to an analysis system for identification and concentration determination. The analysis system can include a Time of Flight (TOF) mass spectrometer, a Triple Quadrupole (Triple Quad or QQQ) mass spectrometer, a gas chromatography-mass spectrometry (GC-MS) system, a gas chromatography-flame ionization detector (GC-FID), or other analysis system utilized for organic molecule analysis, or combinations thereof.
In aspects, the present disclosure is directed, at least in part, to systems and methods for collecting and combining multiple scan samples for analysis of contaminants that may be present on a semiconductor wafer. A sample collection vessel can be used to collect multiple scans from a scan nozzle or scan nozzles prior to transfer of a combined sample to an analysis device (e.g., ICP-MS, time of flight spectrometer, etc.). Multiple wafer scans are collected in the sample collection vessel and permitted to mix into a single sample for transfer to the analysis device. In implementations, the scan nozzle or scan nozzles can utilize the same or different scan solutions to target different compositions of contaminants (e.g., metallic, organic, etc.) to provide a single sample that includes a full recovery profile of wafer contaminants. For example, one or more scans can be performed utilizing polar solvents, non-polar solvents, aqueous solutions, or combinations thereof, where the scans are introduced to the sample collection vessel, mixed as a single sample, and transferred to the analysis device for identification and quantification of the contaminants.
In aspects, the present disclosure is directed, at least in part, to systems and methods for inline generation of organic scan solutions and internal standards for analysis of organic contaminants that may be present on a semiconductor wafer. A pump system is fluidically coupled with a plurality of organic solvents, internal standards, or combinations thereof to transfer two or more of the organic solvents and internal standards to an inline mixing device (e.g., a mixing port of a multiport valve, a multiport mixing manifold, etc.). A controller can control operation of the system to draw, on demand, the precise amounts of organic solvents and internal standards for mixing and the timing of delivery to the scan nozzle for dispensing onto one or more surfaces of the semiconducting wafer. The system provides for auto-calibration of organic analysis systems by allowing for varying concentrations of internal standards to be introduced to organic solvents to create calibration curves with high precision. Further, the system can generate a variety of organic scan solutions utilizing any combination of solvents and analytes that are fluidically coupled to the pump system. Inline generation of the organic scan solutions reduces the likelihood of environmental contamination to the semiconducting wafer or the chemicals used in the analysis thereof, while also permitting precise control of fluids introduced to the scan nozzle which can allow for small volumes of organic solvents to be utilized (e.g., thereby increasing analytical capability for lower contaminant detection limits).
The chamber 102 includes a chamber body 116 defining an interior region 118 to receive the wafer 108 for processing. A ledge 120 projects into the interior region 118 between a top portion 122 of the chamber body 116 and a bottom portion 124 of the chamber body 116. In implementations, the chamber body 116 defines a first aperture 126 at the top portion 122 through which the wafer 108 can be received into the interior region 118. In implementations, the ledge 120 defines a second aperture 128 at an intermediate portion of the interior region 118 between the top portion 122 and the bottom portion 124 (e.g., between the first aperture 126 and the bottom portion 124). During an example operation shown in
The system 100 can include a lid 130 to isolate the interior region 118 from an exterior region 132 to facilitate wafer decomposition while limiting exposure of the decomposition fluid to the exterior region 132. For example, the lid 130 can have a size and a shape to cover the first aperture 126 when positioned over the first aperture 126. The lid 130 can be positionable between an open position (e.g., shown in
Following introduction of the wafer 108 to the wafer support 110, the system 100 can transition to a decomposition configuration to facilitate decomposition of one or more surfaces or edges of the wafer 108. For instance, the system 100 can support decomposition of the wafer 108 prior to scanning for inorganic contaminants, although decomposition could be utilized for detecting certain organic contaminants. Alternatively or additionally, the system 100 can transition to a scanning configuration (e.g., described further herein) without a prior decomposition procedure. For the decomposition configuration, the motor system 112 can move the wafer support 110 from the first position to the second position to position the wafer 108 adjacent the second aperture 128 of the ledge 120 (e.g., as shown in
In implementations, the chamber 102 induces a pressure beneath the wafer 108 during decomposition to prevent decomposition fluid from passing between the edge of the wafer 108 and the ledge 120. For example, the chamber 102 can include a gas outlet port 148 within the interior region 118 positioned between the second aperture 128 and the bottom portion 124 of the chamber body 116 to introduce a gas or other fluid into the interior region 118 during introduction of the decomposition fluid from the nebulizer 138 into the interior region 118. The gas from the gas outlet port 148 can be introduced at a pressure greater than the pressure of aerosolized decomposition fluid supplied from the nebulizer 138 to provide an upward flow of the gas through the second aperture 128 (e.g., between the edge of the wafer 108 and the ledge 120) to prevent the passage of the decomposition fluid beneath the wafer 108. In implementations, the system 100 includes a controller coupled to a gas source to introduce gas from the gas source to the gas outlet port 148 during introduction of the decomposition fluid onto the surface 146 of the wafer 108 by the nebulizer 138 when the wafer support 110 is positioned at the second position. For example, the gas can be fed to the gas outlet port 148 via a fluid line through the conduit 140 and the antechamber 142. In implementations, the motor system 112 induces rotation of the wafer support 110 during the decomposition procedure to spin the wafer 108 when the aerosolized decomposition fluid is present in the interior region 118.
The chamber 102 can facilitate removal of the fluids from the interior region 118 through one or more channels in the chamber body 116 in fluid communication with one or more drains, where such fluids can include, for example, excess decomposition fluid, silicon tetrafluoride (SiF4), gas supplied by the gas outlet port 148, water, water vapor, rinse fluids, or other fluids. For example, the chamber body 116 can include a base portion 200, an intermediate portion 202, and a top portion 204 (e.g., shown in
Following decomposition of the wafer 108, or in implementations where no prior decomposition is desired, the system 100 can transition to a scanning configuration to permit access to the surface 146 of the wafer 108 by the scan arm assembly 104 without transferring the wafer 108 to a separate scanning system. To transition to the scanning configuration, the motor system 112 can position the wafer support 110 from the second position adjacent the second aperture 128 to the first position adjacent the first aperture 126, or otherwise closer to the top portion 122 of the chamber body 116 to permit access to the surface 146 of the wafer 108 by the scan arm assembly 104. Alternatively, the motor system 112 can maintain the wafer 108 near the top portion 122 following loading if no decomposition procedure is utilized for a particular scan.
The scan arm assembly 104 generally includes a rotatable arm support 300 coupled to a nozzle housing 302 that supports a nozzle 304 configured to introduce the scan fluid to the surface 146 of the wafer 108 and recover the scan fluid from the surface 146 of the wafer 108. The motor system 112 can control rotation of the rotatable arm support 300, vertical positioning of the rotatable arm support 300, or combinations thereof, to position nozzle housing 302 and nozzle 304 from one or more positions at the rinse station 114 (e.g., shown in
With the nozzle 304 in position adjacent or above the wafer 108 (e.g., shown in
The nozzle hood 510 extends from the nozzle body 500 adjacent each of the first nozzle port 506 and the second nozzle port 508 and defines the channel 512 between the nozzle hood 510 and the nozzle body 500 between the first nozzle port 506 and the second nozzle port 508. The nozzle hood 510 can further extend to include each of the first nozzle port 506 and the second nozzle port 508 within the channel 512 such that the nozzle hood 510 encloses the first nozzle port 506 and the second nozzle port 508 within the nozzle hood 510 (e.g., as shown in
The channel 512 of the nozzle 304 have an elongated shape with rounded ends 513A and 513B. Rounded ends can promote superior fluid handling characteristics as compared to angled ends, such as by providing more consistent delivery and uptake of fluid through the nozzle 304. In implementations, the first nozzle port 506 (where the fluid is dispensed from the nozzle 304 onto the wafer 108) is positioned tangent to the edge of the rounded end 513A of the channel 512. Such positioning can assist with a clean break of the fluid stream from the first nozzle port 506 once all fluid has been introduced to the wafer 108, while avoiding segmentation of the fluid on the surface of the wafer 108. In implementations, the rotatable arm support 300 rotates the nozzle housing 302 to cause the rounded end 513A of the nozzle 304 to extend over the edge of the wafer 108 (e.g., following the scan procedure) to promote uptake of the stream of fluid through the second nozzle port 508 via operation of the fluid handling system 106. For example, as shown in
The position of the nozzle 304 above the surface 416 of the wafer 108 can influence the amount of fluid supported within the channel 512 during the scan procedure. The system 100 can include a zeroing procedure to ensure a desired height above the surface 416 is achieved prior to introduction of scanning fluid to the nozzle to facilitate the desired amount of fluid to be guided by the nozzle hood 510 along the surface 146 of the wafer 108. An example zeroing procedure is shown with respect to
In implementations, the nozzle mount assembly 500 includes the nozzle housing 302 to couple the nozzle 304 to the rotatable arm support 300. Alternatively or additionally, one or more different scan nozzles can be coupled directly to the rotatable arm support 300, or can utilize a different nozzle housing to facilitate coupling to the rotatable arm support 300. As shown, the nozzle 304 can be coupled to the nozzle housing 302 via a coupler 524 defining an aperture 526 to interact with a protrusion 528 of the nozzle housing 302. The protrusion 528 can include a fastener, pin, or other structure having a width or diameter that is less than a width or diameter of the aperture 526, such that when the scan arm assembly 104 is in a first state (e.g., a leveling state), the top of the aperture 526 rests on the protrusion 528, which provides a lower or extended position of the nozzle 304 with respect to the nozzle housing 302 via the coupler 524 (e.g., as shown in
The nozzle housing 302 can include sensors to monitor a position of the nozzle 304 with respect to the nozzle housing 302, such as to determine whether the nozzle 304 is in the extended state, in the retracted state, or in a different position. For example, in implementations, the nozzle housing 302 includes a sensor 532 to detect the presence or absence of the coupler 524 and generate or cease generating a signal received by a controller of the system 100. The sensor 532 can include an optical switch with a light source on a first side of the coupler 524 and a detector on a second opposing side of the coupler 524. The coupler 524 can include an indexing cutout, a portion of which passes between the light source and the detector of the sensor 532. When the nozzle 304 is in the extended position (e.g., the lock structure 530 is not engaged), light from the light source passes through the indexing cutout of the coupler 524 and is detected by the detector on the other side of the coupler 524. The sensor 532 then outputs a signal or ceases outputting a signal indicating detection of the light, which indicates to the system 100 that the nozzle 304 is in the extended position. When the nozzle 304 is in the retracted position, such as after being leveled on the surface 522, the body of the coupler 524 is positioned between the light source and detector of the sensor 532, blocking the light from reaching the detector. The sensor 532 would output a signal or cease outputting a signal indicating no detection of the light source. Such a signal or lack thereof indicates to the system 100 that the nozzle 304 is in the retracted position (e.g., supported in the nozzle housing 302 by the lock structure 530). Operation of the sensor 532 can provide a system check to ensure that the nozzle 304 is still in a retracted and leveled position after a period of operation. Changes in the output from the sensor 532 can indicate that a releveling procedure may be appropriate, the lock structure 530 should be evaluated, etc. Alternatively, the indexing cutout could be repositioned such that when the nozzle 304 is in the retracted position, the detector is aligned with the indexing cutout, and when the nozzle 304 is in the extended position, the body of the coupler 524 blocks the light.
When the nozzle 304 is leveled with respect to the surface 522 and locked into position via the lock structure 530, the rotatable arm support 300 can lift the nozzle 304 from the surface 522 (e.g., as shown in
The nozzle housing 302 can include one or more sensors to facilitate introducing fluid to the nozzle 304 and removing fluid from the nozzle 304. For example, in implementations, the nozzle housing 302 includes one or more sensors (sensors 534A and 534B are shown) adjacent to or more of the inlet port 502 and the outlet port 504 of the nozzle 304 to control operation of the fluid handling system 106 to control the flow of fluid into and out of the nozzle 304. The sensors 534A and 534B can include an optical sensor, a capacitive sensor, an ultrasonic sensor, or other sensor, or combinations thereof to sense the flow of liquid or the absence thereof within the fluid lines of the system 100. For example, the system 100 can include fluid lines from the fluid handling system coupled to fluid line couplers 536A and 536B through which the sensors 534A and 534B, respectively, can detect the present or absence of fluid therein. Output signals, or the lack thereof, can control operation of one or more components of the fluid handling system 106 including, but not limited to, pumps utilized to introduce fluid to or remove fluid from the nozzle 304.
The system 100 facilitates rinsing procedures for the wafer 108 and for the nozzle 304, such as following scan procedures. Referring to
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While VPD techniques can be appropriate for detection and identification of metallic impurities, there may be significant restrictions in use of traditional VPD techniques for recovery and identification of organic contaminants or residues present in or on semiconducting wafers that can adversely affect semiconductor processing. For example, plasticizers, such as di-butyl phthalate and di-octyl phthalate, can slow silicon dioxide growth. Organophosphates may cause unintentional doping. Amines can neutralize photo-generated acids. Antioxidants, such as butylated hydroxytoluene and butylated hydroxyanisole, can degrade gate-oxide constructs on a wafer. Surfactants, such as cetrimonium bromide and sodium dodecylsulfate, can add hydrophilicity to wafers. Decomposition fluids used in traditional VPD techniques can break down organic molecules or otherwise react with the organic molecules to prevent identification of the original contaminants and prevent determination of concentrations of the original contaminants present on the semiconducting wafer. Similarly, certain analysis systems used in VPD systems do not facilitate the recovery and identification of organic contaminants or residues. For instance, inductively-coupled plasma systems used in the identification of metallic impurities can prevent the identification of the arrangement of the elements present in the organic sample, where such arrangement would be used to determine the appropriate identity of the original organic molecule.
The semiconducting wafer 1106 is shown in
Referring to
Organic solvents can have a relatively high vapor pressure in ambient environments, which causes the organic solvent to vaporize over time, resulting in less liquid solvent available to interact with organic contaminants present on the semiconducting wafer 1106. Alternatively or additionally, organic solvents have a tendency to spread onto the surface of the semiconducting wafer 1106 due to the relatively low surface tension of the fluids, causing portions of the scan solution to spread out from the area underneath the scan nozzle and onto the surface away from normal control by the nozzle 1102. In implementations, the system 1110 includes an organic scan solution replenishment system to facilitate introduction of organic scan solutions to the semiconducting wafer 1106 while maintaining suitable amounts of the organic scan solutions for manipulation by the scan nozzle 1102. For example, referring to
The organic scan solution replenishment system 1118 is shown generally including a scan solution reservoir 1122, a pump 1124, and corresponding fluid lines 1126 to fluidically couple the scan solution reservoir 1122 with the nozzle 1102. The scan solution reservoir 1122 can be any suitable container to house a portion of organic scan solution for subsequent transfer to the nozzle 1102 to replenish the amount of scan solution positioned underneath the scan nozzle 1102 for movement across the semiconducting wafer 1106. In implementations, the scan solution reservoir 1122 is a closed container to prevent evaporation of organic scan solution from the scan solution reservoir 1122. The scan solution reservoir 1122 is fluidically coupled with the nozzle 1102 via the fluid lines 1126 through which the pump 1124 can transfer the scan solution held within the scan solution reservoir 1122 to the nozzle 1102. The pump 1124 can include a peristaltic pump, a syringe pump, another pump, or combinations thereof, suitable to transfer the scan solution held within the scan solution reservoir 1122 to the nozzle 1102 to replenish organic scan solution that has evaporated or otherwise spread from surface of the semiconducting wafer 1106 that is maintained under control underneath the nozzle 1102. In implementations, the pump 1124 is controlled to transfer the scan solution held within the scan solution reservoir 1122 to the nozzle 1102 via the fluid lines 1126 at a substantially constant flow rate. For example, the pump 1124 can continuously transfer scan solution to the nozzle 1102. The rate of the transfer from the pump 1124 generally depends on the makeup of the organic scan solution, where higher flow rates can be facilitated by the pump 1124 for more volatile organic solvents. Alternatively or additionally, the system 1110 can include one or more sensors to determine a volume of scan solution manipulated by the nozzle 1102, where when the volume is determined to be at or less than a threshold volume, the system 1110 can activate the pump 1124 to transfer replenishment scan solution (e.g., for a predetermined time, until the volume is determined to be above the threshold volume, or the like).
After the organic scan solution is permitted to interact with the surface of the semiconducting wafer to draw organic contaminants or residue into the scan solution, the scan nozzle 1102 can then draw the scan solution from the semiconducting wafer 1106 with the organic contaminants 1108 and 1110 included in the scan solution (e.g., shown as 1114), as shown in
In an implementation, the analysis system 1112 of the system 1100 includes a Q-TOF-MS calibrated using a method of standard addition (MSA) calibration. The quantification methodology of the analysis system 112 can depend on whether the detected contaminant is part of the calibration standard used for the MSA calibration. For instance, if the detected contaminant is part of the calibration standard used for the MSA calibration, then the Q-TOF-MS can be operated in Full Quant analysis mode. If the detected contaminant is not part of the calibration standard used for the MSA calibration, then the Q-TOF-MS can be operated in Near Quant analysis mode. For example, operating the Q-TOF-MS in Near Quant analysis mode can include utilizing a response factor (RF) for an organic compound having similar characteristics (e.g., polarity, functional groups, molecular weight, etc.) as the detected contaminant.
In an example experiment, an analysis was performed utilizing the system 1100 to determine collection and analysis of multiple organic contaminants from a semiconducting wafer. During the analysis, a sample of isopropyl alcohol (IPA) was spiked with twenty-four contaminants, each at a concentration of 10 parts per billion (ppb). The contaminants included bromide, phosphate, ethylisopropylamine, diethanolamine, heptylamine, diethylaminoethanol, tripropylamine, tributylamine, sodiumdodeculsulfate, aminopropanol, L-proline, trimethyl glycine, L-leucine, bisethylhexylphosphate, tributylphosphate, trischloropethylphosphate, triphenylphosphate, trisethylhexylphosphate, dibutylphthalate, butylbenzylphthalate, dioctylphthalate, diisononylphthalate, diisodecylphthalate, and tris (2,4-ditert-butylphenyl) phosphate (e.g., a potential contaminant for IPA stored in a high density polyethylene (HDPE) container). A 1 mL amount of the spiked IPA was introduced to the semiconductor wafer as small drops in differing locations on the surface of the wafer. The IPA was permitted to evaporate, leaving the contaminants behind on the surface of the wafer as residue. The wafer surface was then scanned with an organic scan solution to dissolve the residue in the organic scan solution. The scan solution containing the contaminants was collected and transferred to an analysis system for identification and quantification of the recovery of the contaminants. Referring to
The nozzle 1302 is configured to introduce a scan solution to the semiconducting wafer (e.g., wafer 108, wafer 1106, etc.), perform a scan procedure through movement of the scan solution relative to one or more surfaces of the wafer, and remove the scan solution from the wafer. For instance, fluid handling by the nozzle 1302 can be facilitated through operation of one or more fluid pumps (e.g., syringe pumps, peristaltic pumps, or the like). The scan solution is transferred from the nozzle 1302 to the collection vessel 1304 to hold the scan solution within an interior volume of the collection vessel 1304 until one or more additional scan solutions are transferred from the nozzle 1302 (or a different nozzle) to the collection vessel 1304 for collection and combination with the first scan solution. For example, the nozzle 1302 can introduce a first scan solution to the wafer, perform a first scan procedure, remove the first scan solution from the wafer as a first scan sample 1308, and transfer the first scan sample 1308 to the collection vessel 1304. The system 1300 can then facilitate a second scan, where the nozzle 1302 (or a different nozzle) introduces a second scan solution to the same wafer, perform a second scan procedure, remove the second scan solution from the wafer as a second scan sample 1310, and transfer the second scan sample 1310 to the collection vessel 1304 for combination with the first scan sample 1308. The system 1300 can further facilitate additional scans for combination with the other scans (e.g., one or more additional scan samples 1312 can optionally be added to the collection vessel 1304 for mixing with the other samples present, such as the first scan sample 1308 and/or the second scan sample 1310). The collection vessel 1304 then provides a combined scanned sample 1314 within the vessel interior for transfer to the analysis system 1306.
The collection vessel 1304 can be provided according to a variety of configurations suitable to hold a plurality of scan samples. For instance, the collection vessel 1304 can include, but is not limited to, a tubular structure, a tubular structure having a conical or angled bottom, a laboratory tube or vial, a length of fluid tubing configured to mix received samples back and forth, a sample bottle, or the like, or combinations thereof. For example, the collection vessel 1304 shown in
The system 1300 can facilitate combining multiple scans into a single scan sample to increase recovery efficiency for the sample. For instance, rather than relying on a single scan to collect all contaminants of interest from the wafer (e.g., wafer 108), the system 1300 can utilize a first scan solution to recover a first portion of the contaminants or residues present on the wafer (e.g., 80% of contaminants on a single scan). The system 1300 can then utilize the same scan solution or a different scan solution for a second scan to recover a portion of the remaining contaminants on the same wafer (e.g., 80% of the remaining 20% of contaminants on a second scan). Additional scan(s) can be performed to target more of any residual contaminants. The system 1300 can utilize multiple scans to target different types of contaminants including, but not limited to, polar molecules, non-polar molecules, metal contaminants, ionic contaminants, or the like, or combinations thereof using one or more scan solutions or combinations of scan solutions including, but not limited to, polar organic solvents, non-polar organic solvents, aqueous solutions (e.g., acidic solutions, basic solutions, neutral solutions, etc.), or the like. The collection vessel 1304 facilitates combining and mixing scans with the same or different scan solutions to provide a full recovery profile of contaminants of the wafer.
Following collection of two or more scans in the collection vessel 1304, the system 1300 facilitates transfer of the combined scan sample 1314 to the analysis system 1306 for identification and/or quantification of the contaminants. For example, the system 1300 can utilize one or more pumps or vacuum sources to pull or push the combined scan sample 1314 out from the collection vessel 1304 and through the valve 1406 to the analysis system via one or more fluid lines (e.g., fluid line 1410 is shown). The analysis system 1306 can include one or more detectors used to process the combined scan sample 1314 or portions thereof. For example, the analysis system 1306 can include one or more of a Time of Flight (TOF) mass spectrometer, a Triple Quadrupole (Triple Quad or QQQ) mass spectrometer, a gas chromatography-mass spectrometry (GC-MS) system, a gas chromatography-flame ionization detector (GC-FID), or other analysis system utilized for organic molecule analysis, an ICP spectrometry instrumentation (e.g., an Inductively Coupled Plasma Mass Spectrometer (ICP/ICP-MS), an Inductively Coupled Plasma Atomic Emission Spectrometer (ICP-AES), or the like), or other analysis system utilized for metal analysis, or combinations thereof.
Referring to
The system 1500 is shown in
In implementations, the system 1500 includes a controller 1512 that controls and coordinates operation of the pump system 1504 and the valve system 1506 to draw a plurality of organic solvents or chemical standards from the organic chemical sources 1508 and introduce the plurality of organic solvents together to form an organic scan solution or introduce one or more chemical standards with one or more organic solvents or diluents to form a calibration standard. The fluids can be introduced to mix within one or more valves of the valve system 1510 (e.g., via one or more mixing ports of a multi-port valve or multiple multiport valves), can be introduced to mix within a multiport mixing manifold, can be introduced to another mixing device, or combinations thereof.
The mixed organic fluids can then be transferred to the nozzle 1502 for introduction to the semiconductor wafer 108 for the scanning procedure. For example, the controller 1512 can coordinate operation of the pump system 1504 and the valve system 1506 to transfer the mixed organic scan solution or the mixed calibration standard to the nozzle 1502 whereby one or more of the scan arm assembly 104 and the motor system 112 induce relative motion between the nozzle 1502 and the semiconductor wafer 108 to move the mixed organic scan solution across the surface of the semiconductor wafer 108. Following or during the scanning procedure, the nozzle 1502 recovers the mixed organic scan solution from the wafer 108 and directs the sample to an analysis system 1514. The analysis system 1514 can include one or more of a Time of Flight (TOF) mass spectrometer, a Triple Quadrupole (Triple Quad or QQQ) mass spectrometer, a gas chromatography-mass spectrometry (GC-MS) system, a gas chromatography-flame ionization detector (GC-FID), or other analysis system utilized for organic molecule analysis, an ICP spectrometry instrumentation (e.g., an Inductively Coupled Plasma Mass Spectrometer (ICP/ICP-MS), an Inductively Coupled Plasma Atomic Emission Spectrometer (ICP-AES), or the like), or other analysis system utilized for metal analysis, or combinations thereof. In implementations, a series of mixed calibration standards can be transferred directly to the analysis system 1514 to generate calibration curves for analysis of samples provided through inline generated organic scan solutions.
An example implementation of the system 1500 is shown in
Electromechanical devices (e.g., electrical motors, servos, actuators, or the like) may be coupled with or embedded within the components of the systems described herein (e.g., systems 100, 1100, 1300, 1500 or combinations thereof) to facilitate automated operation via control logic embedded within or externally driving the systems. The electromechanical devices can be configured to cause movement of devices and fluids according to various procedures, such as the procedures described herein. The systems may include or be controlled by a computing system having a processor or other controller configured to execute computer readable program instructions (i.e., the control logic) from a non-transitory carrier medium (e.g., storage medium such as a flash drive, hard disk drive, solid-state disk drive, SD card, optical disk, or the like). The computing system can be connected to various components of the system 100, either by direct connection, or through one or more network connections (e.g., local area networking (LAN), wireless area networking (WAN or WLAN), one or more hub connections (e.g., USB hubs), and so forth). For example, the computing system can be communicatively coupled to the chamber 102, the motor system 112, valves described herein, pumps described herein, other components described herein, components directing control thereof, or combinations thereof. The program instructions, when executed by the processor or other controller, can cause the computing system to control the systems (e.g., control pumps, selection valves, actuators, spray nozzles, positioning devices, etc.) according to one or more modes of operation, as described herein.
It should be recognized that the various functions, control operations, processing blocks, or steps described throughout the present disclosure may be carried out by any combination of hardware, software, or firmware. In some embodiments, various steps or functions are carried out by one or more of the following: electronic circuitry, 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 personal computing system, a mobile computing device, mainframe computing system, workstation, image computer, parallel processor, or any other device known in the art. In general, the term “computing system” is broadly defined to encompass any device having one or more processors or other controllers, which execute instructions from a carrier medium.
Program instructions implementing functions, control operations, processing blocks, or steps, such as those manifested by embodiments described herein, may be transmitted over or stored on 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 or optical disk, a solid-state or flash memory device, or a magnetic tape.
The systems described herein (e.g., systems 100, 1100, 1300, 1500) can include one or more features of another system of the systems described herein, unless context dictates that such features would be otherwise incompatible. For example, and without limitation, the system 100 can include one or more of the organic scan solution replenishment system 1118, the collection vessel 1304, and the inline organic scan solutions and internal standards generation system 1500 in combination with, or to the exclusion of, one or more other features of another system described herein.
Furthermore, it is to be understood that the invention is defined by the appended claims. Although embodiments of this invention have been illustrated, it is apparent that various modifications may be made by those skilled in the art without departing from the scope and spirit of the disclosure.
The present application claims the benefit of 35 U.S.C. § 119 (e) of U.S. Provisional Application Ser. No. 63/536, 194, filed Sep. 1, 2023, and titled “SYSTEMS AND METHODS FOR RECOVERY AND IDENTIFICATION OF ORGANIC CONTAMINANTS AND RESIDUE ON SEMICONDUCTOR WAFER SURFACES,” of U.S. Provisional Application Ser. No. 63/585,787, filed Sep. 27, 2023, and titled “COLLECTION AND COMBINATION OF MULTIPLE SCAN SAMPLES FOR SEMICONDUCTOR WAFER ANALYSIS,” of U.S. Provisional Application Ser. No. 63/585,805, filed Sep. 27, 2023, and titled “INLINE GENERATION OF ORGANIC SOLVENT SCAN SOLUTION FOR SEMICONDUCTOR WAFER ANALYSIS,” and of U.S. Provisional Application Ser. No. 63/585,810, filed Sep. 27, 2023, and titled “SYSTEMS AND METHODS FOR RECOVERING ORGANIC CONTAMINANTS FROM SEMICONDUCTING WAFERS.” U.S. Provisional Applications Ser. Nos. 63/536, 194, 63/585,787, 63/585,805, and 63/585,810 are herein incorporated by reference in their entireties.
Number | Date | Country | |
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63536194 | Sep 2023 | US | |
63585787 | Sep 2023 | US | |
63585805 | Sep 2023 | US | |
63585810 | Sep 2023 | US |