Contaminant detection tool and related methods

Abstract

This application relates to contamination detection tools and related methods. A contamination detection method includes exposing a wafer including one or more contaminants to a microdroplet of oxidizing agent to form an oxide on a surface of the wafer, exposing the oxide to an etchant to remove the oxide and leave the one or more contaminants on the surface of the wafer, and determining a composition of the one or more contaminants. Additional methods and related tools are also disclosed.

Description

[0001] Information related to divisional application

[0002] This application is a divisional application of the invention patent application filed on September 24, 2020, with application number "202011014483.2" and title "Pollutant Detection Tool and Related Method".

[0003] Priority Claim

[0004] This application claims the benefit of the filing date of U.S. Patent Application Serial No. 16 / 582,420, filed on September 25, 2019, concerning “Contaminant Detection Tools and Related Methods”. Technical Field

[0005] Embodiments of the present invention relate to the field of microelectronic device manufacturing. More specifically, the embodiments disclosed herein relate to contaminant detection tools and related methods. Background Technology

[0006] The fabrication of microelectronic devices involves forming components of the microelectronic device, such as electrodes, transistors, capacitors, memory materials, and other components, under clean conditions. For example, the fabrication of microelectronic devices includes forming and patterning dielectric materials, conductive materials, photoresist materials, and other materials. However, the formation and patterning of such materials can leave residues and various contaminants in the microelectronic device fabrication tools, which can be detrimental to the successful fabrication of the microelectronic device if exposed to such materials during other fabrication operations. As an example, metals used during the formation of various conductive components of a microelectronic device may undesirably remain in the fabrication tools used to form metallic materials. Unfortunately, during other fabrication operations, such as during the formation of one or more electrically insulating materials, metals within the wafer, on the wafer surface, and retained in the microelectronic device fabrication tools can undesirably contaminate the microelectronic device.

[0007] Furthermore, during the manufacture of a microelectronic device, the device may be moved from one manufacturing tool to another. However, moving the microelectronic device between various manufacturing tools can expose it to various contaminants. Additionally, the manufacturing tools may contain undesirable contaminants, which may include one or more materials previously formed in the manufacturing tool, for example, during the manufacture of another microelectronic device. Manufacturing components of a microelectronic device in the presence of one or more contaminants may lead to eventual failure and / or reduced functionality of the microelectronic device.

[0008] Therefore, it is generally desirable to remove contaminants from microelectronic devices and from the manufacturing tools of microelectronic devices before proceeding with subsequent processing. For example, after forming and patterning a conductive material such as titanium or titanium dioxide, it may be desirable to remove titanium from the manufacturing tools before forming other materials (such as electrically insulating materials, such as silicon dioxide), which could otherwise be contaminated by the presence of titanium in the manufacturing tools.

[0009] Because contamination of microelectronic devices can ultimately lead to their failure, successful microelectronic device manufacturing involves monitoring manufacturing tools and the wafers on which the microelectronic devices are formed during various manufacturing processes for one or more contaminants. Some methods for identifying the presence of one or more contaminants include total internal reflection x-ray fluorescence (TXRF), vapor phase decomposition total internal reflection x-ray fluorescence (VPD-TXRF), vapor phase decomposition inductively coupled plasma mass spectrometry (VPD-ICP-MS), and synchrotron radiation total internal reflection x-ray fluorescence (SR-TXRF). Each detection method may exhibit advantages and disadvantages compared to others. For example, TXRF and VPD-TXRF are generally unsuitable for detecting elements such as lithium, beryllium, and boron, and have difficulty detecting sodium, magnesium, aluminum, and other elements. Besides microelectronic device manufacturing, used wafers may be recycled for reuse in other applications. It may be necessary to detect contaminants within materials used in microelectronic device manufacturing, such as recycled wafers, films, test wafers, or other wafers. Summary of the Invention

[0010] In some embodiments, a contaminant detection method includes exposing a wafer containing one or more contaminants to droplets of an oxidant to form an oxide on the surface of the wafer, exposing the oxide to an etchant to remove the oxide and leave the one or more contaminants on the surface of the wafer, and determining the composition of the one or more contaminants.

[0011] In other embodiments, a method for detecting at least one contaminant includes: atomizing an oxidant to form an aerosol, exposing a wafer to the aerosol to form an oxide on the wafer surface, exposing the oxide to an etchant to remove the oxide, contacting the surface of the wafer with at least one droplet of a scanning solution to dissolve material in the at least one droplet, and analyzing the at least one droplet of the material.

[0012] In other embodiments, a contaminant detection tool includes: a chuck configured to receive a wafer, the chuck being configured to rotate at an angle; an arm configured to move about a surface of the chuck; and an atomizer coupled to the arm and in fluid communication with an oxidant and a carrier gas, the atomizer being configured to generate an aerosol comprising droplets of the oxidant.

[0013] In another embodiment, a method includes placing a wafer on a wafer chuck of a tool including an atomizer in fluid communication with an oxidant and a carrier gas, forming an aerosol comprising droplets of the carrier gas and the oxidant, and exposing the surface of the wafer to the aerosol to form an oxide on the surface of the wafer. Attached Figure Description

[0014] Figure 1 This is a simplified cross-sectional view of an atomizer according to an embodiment of the present invention.

[0015] Figure 2 This is a simplified flowchart of a method for detecting one or more contaminants in one or more of a microelectronic device manufacturing tool and a wafer used to manufacture a microelectronic device, according to an embodiment of the present invention; and

[0016] Figure 3 It includes embodiments of the present invention. Figure 1 A simplified schematic diagram of an atomizer and a tool configured to expose a wafer to an aerosol. Detailed Implementation

[0017] The descriptions contained herein are not intended to be actual views of any particular system, microelectronic structure, microelectronic device, or its integrated circuit, but are merely idealized representations used to describe the embodiments herein. Common elements and features between the figures may retain the same numerical designations, except for figure numbers that begin with reference numerals introduced thereon or that best describe the element as described below.

[0018] The following description provides specific details, such as material types, material thicknesses, and processing conditions, to provide a thorough description of the embodiments described herein. However, those skilled in the art will understand that the embodiments disclosed herein can be practiced without these specific details. In fact, the embodiments can be practiced in conjunction with conventional manufacturing techniques used in the semiconductor industry. Furthermore, the description provided herein does not constitute a complete description of methods for forming oxides on the surface of a wafer (e.g., a wafer used in microelectronic device manufacturing, testing, recycling, or as a film on a wafer), methods for detecting one or more contaminants in or on a wafer or within a microelectronic device manufacturing tool, or related systems for forming oxides or detecting one or more oxides. The structures described below do not constitute a complete microelectronic device or integrated circuit. Only the process actions and structures necessary for understanding the embodiments described herein are described in detail below. Additional actions for forming oxides or detecting one or more contaminants on the surface of a wafer or microelectronic device can be performed using conventional techniques.

[0019] Unless otherwise indicated below, the materials described herein can be formed using conventional techniques, including (but not limited to) spin coating, blanket coating, chemical vapor deposition (CVD), atomic layer deposition (ALD), plasma-enhanced ALD (PEALD), physical vapor deposition (PVD), plasma-enhanced chemical vapor deposition (PECVD), or low-pressure chemical vapor deposition (LPCVD). Alternatively, the material can be grown in situ. Depending on the specific material to be formed, those skilled in the art may choose the technique for depositing or growing the material. Material removal can be achieved by any suitable technique including (but not limited to) etching, abrasive planarization (e.g., chemical mechanical planarization), or other known techniques, unless the context otherwise indicates.

[0020] As used herein, the terms “longitudinal,” “vertical,” “lateral,” and “horizontal” refer to the principal plane of a substrate (e.g., substrate material, substrate structure, substrate configuration, etc.) in which one or more structures and / or features are formed, and are not necessarily defined by the Earth’s gravitational field. A “lateral” or “horizontal” direction is a direction substantially parallel to the principal plane of the substrate, while a “longitudinal” or “vertical” direction is a direction substantially perpendicular to the principal plane of the substrate. The principal plane of the substrate is defined by a surface of the substrate that has a relatively large area compared to the other surfaces of the substrate.

[0021] As used herein, the term "substantially" with respect to a given parameter, property, or condition means, to the extent that a person skilled in the art would understand, and includes that the given parameter, property, or condition is satisfied within a certain degree of variance (e.g., within acceptable tolerances). By way of example, depending on the specific parameter, property, or condition that is substantially satisfied, the parameter, property, or condition may be satisfied at least 90.0%, at least 95.0%, at least 99.0%, at least 99.9%, or even 100.0%.

[0022] As used herein, “and / or” includes any and all combinations of one or more of the associated listed items.

[0023] As used herein, “about” or “approximately” with respect to a particular parameter includes the value and a degree of deviation from the value that would be considered by a person skilled in the art to be within acceptable tolerances for the particular parameter. For example, “about” or “approximately” with respect to a value may include additional values ​​within the range of 90.0% to 110.0% of the value, such as within the range of 95.0% to 105.0%, within the range of 97.5% to 102.5%, within the range of 99.0% to 101.0%, within the range of 99.5% to 100.5%, or within the range of 99.9% to 100.1%.

[0024] As used herein, spatial relative terms, such as “below,” “under,” “bottom,” “above,” “top,” “front,” “back,” “left,” “right,” and the like, are used for ease of description to describe the relationship of one element or feature to another, as illustrated in the diagrams. Unless otherwise specified, spatial relative terms are intended to cover different orientations of material other than those depicted in the diagrams. For example, if the material in the diagrams were inverted, an element described as “below,” “under,” “below,” or “bottom” of other elements or features would be oriented “above” or “top” of those elements or features. Thus, depending on the context in which the term is used, the term “below” can encompass both above and below orientations, as will be apparent to those skilled in the art. Material may be oriented in other ways (e.g., rotated 90 degrees, inverted, flipped, etc.), and the spatial relative descriptors used herein shall be interpreted accordingly.

[0025] As used herein, the term "microdroplet" refers to and includes droplets of material with an average volume of less than about 1.0 microliter (μL). For example, a microdroplet can have an average volume from about 0.01 μL to about 1.0 μL.

[0026] As used herein, the term "wafer" means and includes structures comprising semiconductor materials, such as (for example) silicon, gallium arsenide, III-V materials (e.g., materials comprising one or more of aluminum, gallium, and indium, and one or more of nitrogen, phosphorus, arsenic, and antimony, such as gallium arsenide, indium phosphide, gallium phosphide, and gallium nitride), II-VI materials (e.g., materials comprising one or both of zinc and cadmium, and one or more of oxygen, sulfur, selenium, and tellurium, such as cadmium selenide, cadmium sulfide, cadmium telluride, zinc oxide, zinc selenide, zinc sulfide, and zinc telluride), or another material. A wafer may comprise a silicon-on-insulator (SOI) wafer, silicon-on-glass, epitaxial wafer, recycled wafer, wafer sample, film (e.g., the surface of a wafer), test wafer, or another type of wafer. In some embodiments, the wafer comprises phosphorus (e.g., black phosphorus). In some embodiments, at least a portion of the wafer (e.g., the surface of the wafer, such as an exposed surface) comprises a metal or a half-metal. For example, at least a portion of the chip may contain aluminum, titanium, vanadium, chromium, manganese, cobalt, nickel, zinc, gallium, zirconium, niobium, ruthenium, rhodium, palladium, cadmium, hafnium, tantalum, tungsten, osmium, iridium, or platinum.

[0027] According to the embodiments described herein, analysis is performed on the presence of one or more contaminants in wafers (e.g., silicon wafers used to manufacture microelectronic devices, recycled wafers, test wafers, wafer samples) or microelectronic device manufacturing tools (also referred to herein as "manufacturing tools") used during the manufacture of microelectronic devices. One or more contaminants can be introduced into the wafer or microelectronic device manufacturing tool through exposure to the surrounding environment or during one or more microelectronic device manufacturing operations (e.g., during material etching, wet etching, dry etching, ion implantation, material deposition (e.g., ALD, CVD, PECVD, PEALD, LPCVD, another deposition method), annealing, or other manufacturing operations). The presence of one or more contaminants in the manufacturing tool can be determined by placing the wafer (e.g., a dummy wafer) in the manufacturing tool and subsequently determining whether the wafer contains contaminants.

[0028] One or more contaminants can be collected for analysis via vapor phase decomposition (VPD) (e.g., via vapor phase decomposition-droplet collection). In some embodiments, at least a portion of the surface of a wafer containing one or more contaminants is oxidized. The surface of the wafer can be oxidized by exposing the surface of the wafer to one or more oxidants. The one or more oxidants may be in the form of a mist, such as an aerosol, which may contain droplets of one or more oxidants. The aerosol may be formed in an atomizer to generate droplets. In some embodiments, one or more oxidants may be fed to an atomizer and mixed with one or more carrier gases to generate an aerosol. In some embodiments, one or more oxidants include hydrogen peroxide. Exposing the surface of the wafer to the oxidant forms an oxide (e.g., silicon dioxide) on the surface of the wafer. The thickness of the oxide can be controlled by introducing the oxidant into the wafer in the form of droplets via an atomizer and by adjusting the concentration of the oxidant. After the oxide is formed on the surface of the wafer, the wafer may be exposed to an etchant formulated and configured to remove the oxide from the surface of the wafer. In some embodiments, the etchant removes the oxide from the wafer without substantially removing one or more contaminants. After oxide removal, the wafer can be exposed to a scanning solution formulated to interact with (e.g., dissolve) one or more contaminants. The scanning solution can be scanned above the wafer surface and subsequently collected from the wafer surface. The scanning solution containing one or more contaminants can be analyzed to determine the presence of one or more analytes. For example, the scanning solution can be analyzed in an inductively coupled plasma mass spectrometry (ICP-MS) instrument. Thus, the presence, concentration, and composition of one or more contaminants in the wafer or manufacturing tool can be determined.

[0029] Compared to conventional methods of oxide formation, forming oxides on wafer surfaces using aerosols generated by an atomizer can be advantageous. For example, forming oxides with an aerosol reduces the likelihood of contaminants present on the wafer surface being washed away, which is often the case when immersing the wafer surface in a liquid to form oxides. According to the embodiments described herein, since such contaminants are not washed away, they can be measured and detected. Additionally, the atomizer facilitates oxide formation with a relatively small volume of oxidant. Because the wafer is oxidized with a relatively small volume of oxidant (as opposed to conventional methods of immersion or spraying wafers), a relatively small volume of potential contaminants is introduced into the wafer via the oxidant. In other words, a smaller volume of oxidant reduces the likelihood of contaminating the wafer with contaminants present in the oxidant. Furthermore, the method of oxidation with microdroplets is relatively faster than conventional methods of oxide formation because it eliminates the need to dry the wafer surface, as is the case in conventional oxide formation by immersion or spraying wafers with a liquid oxidant. In some embodiments, oxides are formed in less than about two minutes after exposure to the microdroplets of oxidant. Using droplets of oxidant formed via an atomizer to form oxides reduces the safety hazards often encountered in alternative methods of oxide formation, which involve bubbling ozone through a liquid medium and exposing the wafer to ozone. Furthermore, the oxidant can be more stable than ozone, which typically decomposes within minutes, while the oxidant used herein remains stable for weeks or months. Additionally, ozone is formed via a catalytic reaction that can introduce metallic contaminants that would otherwise be detected during analysis of the scanning solution, leading to inaccurate detection of contaminants on the wafer. According to the embodiments described herein, forming oxides using an atomizer reduces contaminants that would otherwise be introduced onto the wafer and increases the accuracy of contaminant detection.

[0030] Figure 1 This is a simplified cross-sectional view of an atomizer 100 according to an embodiment of the present invention. The atomizer 100 includes: a liquid inlet port 102 including a capillary 104 (also referred to as a "capillary") extending therethrough; a gas inlet port 106 extending substantially perpendicular to the liquid inlet port 102; and a nozzle 108. The liquid inlet port 102 and the capillary 104 may extend substantially along the longitudinal axis 110 of the atomizer 100. The gas inlet port 106 may extend substantially perpendicular to the longitudinal axis 110.

[0031] Liquid inlet port 102 may be configured to receive liquid to be aspirated by atomizer 100. Capillary 104 may be in fluid communication with liquid 112, which may include an oxidant as described herein. Atomizer 100 may generate an aerosol comprising droplets of liquid 112. Liquid 112 may contain one or more of, for example, hydrogen peroxide, a mixture of hydrogen peroxide, water, and ammonia (which may be referred to as “SC1” or “standard cleaning” solution), nitric acid, sulfuric acid, perchloric acid (HClO4), hydrofluoric acid, or one or both of ozone and hydrogen peroxide and a mixture of one or more acids selected from the group consisting of nitric acid, sulfuric acid, perchloric acid, and hydrofluoric acid. In some embodiments, liquid 112 includes hydrogen peroxide.

[0032] In embodiments where liquid 112 comprises hydrogen peroxide, the hydrogen peroxide may be present in liquid 112 in a weight percentage ranging from about 1 wt% to about 50 wt%, for example, from about 1 wt% to about 5 wt%, from about 5 wt% to about 10 wt%, from about 10 wt% to about 15 wt%, from about 15 wt% to about 20 wt%, from about 20 wt% to about 25 wt%, from about 25 wt% to about 30 wt%, from about 30 wt% to about 35 wt%, from about 35 wt% to about 40 wt%, or from about 40 wt% to about 50 wt%. In some embodiments, liquid 112 comprises from about 25 wt% to about 35 wt% hydrogen peroxide, for example, about 30 wt% hydrogen peroxide. In some embodiments, liquid 112 comprises from about 1 wt% to about 35 wt% hydrogen peroxide.

[0033] The capillary 104 extends through the liquid inlet port 102 and along the longitudinal axis 110 to the nozzle 108. At the nozzle 108, the liquid 112 in the capillary 104 is discharged from the capillary 104 and mixed with the carrier gas 114 from the gas inlet port 106. The diameter of the capillary 104 can range from about 0.10 mm to about 5.0 mm, for example, from about 0.10 mm to about 0.15 mm, from about 0.15 mm to about 0.20 mm, from about 0.20 mm to about 0.25 mm, from about 0.25 mm to about 0.30 mm, from about 0.30 mm to about 0.40 mm, from about 0.40 mm to about 0.50 mm, from about 0.50 mm to about 0.60 mm, from about 0.60 mm to about 0.80 mm, from about 0.80 mm to about 1.0 mm, from about 1.0 mm to about 2.0 mm, from about 2.0 mm to about 3.0 mm, from about 3.0 mm to about 4.0 mm, and from about 4.0 mm to about 5.0 mm. In some embodiments, the diameter of the capillary 104 is in the range of about 0.15 mm to about 0.25 mm.

[0034] The capillary 104 may be configured to supply liquid 112 to the liquid inlet port 102 at a flow rate ranging from about 10 μL / min to about 400 μL / min, for example from about 10 μL / min to about 20 μL / min, from about 20 μL / min to about 30 μL / min, from about 30 μL / min to about 40 μL / min, from about 40 μL / min to about 50 μL / min, from about 50 μL / min to about 75 μL / min, from about 75 μL / min to about 100 μL / min, from about 100 μL / min to about 150 μL / min, from about 150 μL / min to about 200 μL / min, from about 200 μL / min to about 300 μL / min, or from about 300 μL / min to about 400 μL / min. In some embodiments, the capillary 104 provides liquid at a flow rate from about 10 μL / min to about 50 μL / min, for example from about 10 μL / min to about 30 μL / min or from about 30 μL / min to about 50 μL / min.

[0035] Gas inlet port 106 may extend substantially perpendicular to the longitudinal axis 110 of atomizer 100. Gas inlet port 106 may be in fluid communication with a carrier gas 114 used to atomize liquid 112. Carrier gas 114 may comprise any material that substantially does not introduce any contaminants into the aerosol. Carrier gas 114 is coupled to gas inlet port 106 via carrier gas line 116. Carrier gas 114 may comprise one or more of argon, nitrogen, oxygen, a mixture of nitrogen and oxygen (e.g., ambient air), carbon dioxide, nitrous oxide, ozone, helium, or vapor (which may be heated before entering through gas inlet port 106). In some embodiments, carrier gas 114 comprises argon or nitrogen. In use and operation, carrier gas 114 mixes with liquid 112 near nozzle 108 to draw liquid 112 and generate droplets (e.g., microdroplets) of liquid 112. The droplets of liquid 112 exit atomizer 100 as an aerosol through nozzle 108.

[0036] Carrier gas 114 can be supplied to gas inlet port 106 at pressures ranging from about 207 kPa (about 30 psigs per square inch) to about 689 kPa (about 100 psig), for example from about 207 kPa to about 250 kPa, from about 250 kPa to about 300 kPa, from about 300 kPa to about 400 kPa, from about 400 kPa to about 500 kPa, from about 500 kPa to about 600 kPa, or from about 600 kPa to about 689 kPa.

[0037] The average volume of the liquid droplets 112 exiting the aerosol from the atomizer 100 can range from about 0.01 μL to about 1.0 μL, for example, from about 0.01 μL to about 0.02 μL, from about 0.02 μL to about 0.04 μL, from about 0.04 μL to about 0.06 μL, from about 0.06 μL to about 0.08 μL, from about 0.08 μL to about 0.10 μL, from about 0.10 μL to about 0.20 μL, from about 0.20 μL to about 0.30 μL, from about 0.30 μL to about 0.40 μL, from about 0.40 μL to about 0.60 μL, from about 0.60 μL to about 0.80 μL, or from about 0.80 μL to about 1.0 μL. However, the invention is not limited thereto, and the average volume of the droplets may differ from those described.

[0038] Atomizer 100 may include one or more of a fluoropolymer (e.g., perfluoroalkoxyalkane (PFA), polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP), perfluoromethylalkoxy (MFA)), glass (borosilicate glass, quartz), and another inert material. In some embodiments, atomizer 100 includes a hydrophobic material that can promote the reduction or prevention of droplet breakage. In some embodiments, atomizer 100 includes PFA, such as Teflon, commercially available from DuPont of Midland, Michigan. TM .

[0039] In use and operation, liquid 112 at the desired flow rate is supplied to nozzle 108 via capillary 104. Carrier gas 114 is supplied through carrier gas inlet port 106 and proceeds through atomizer 100 to nozzle 108, where carrier gas 114 mixes with liquid 112. Carrier gas 114 flows around capillary 104, thereby forming an annular gas flow around the end of capillary 104 near nozzle 108. As liquid 112 exits capillary 104, carrier gas 114 shears liquid 112 and generates an aerosol comprising droplets having a desired droplet size distribution. At least a portion of the droplets is carried through nozzle 108, which may be configured to guide droplets onto one or more surfaces of a wafer, as will be described herein. In some embodiments, the atomizer 100 may include an exhaust port configured to remove any droplets that may condense on the inner wall of the atomizer 100, thereby substantially reducing or preventing condensed droplets from leaving through the nozzle 108 and onto the material surface where the aerosol is directed.

[0040] Figure 2This is a simplified flowchart of a method 200 for detecting one or more contaminants in one or more of a microelectronic device manufacturing tool and a wafer (e.g., a wafer for manufacturing a microelectronic device, a recycled wafer, a test wafer, a film) according to an embodiment of the present invention. Method 200 may include action 202, which includes introducing a wafer into a microelectronic device manufacturing tool; action 204, which includes exposing the wafer to one or more processing conditions; action 206, which includes exposing the wafer to an aerosol comprising an oxidant to form oxides on at least some surfaces of the wafer; action 208, which includes exposing the oxides to an etchant to remove the oxides from at least some surfaces of the wafer; action 210, which includes introducing droplets of a scanning solution onto the surface of the wafer and scanning the surface of the wafer with said droplets; and action 212, which includes analyzing the droplets of the scanning solution against one or more contaminants.

[0041] Action 202 includes introducing a wafer into a microelectronic device manufacturing tool. In some embodiments, the wafer includes a semiconductor wafer, such as a silicon wafer used during the manufacture of a microelectronic device. The wafer may include a substrate material or structure on which additional material is formed. The substrate material may be a semiconductor substrate, a substrate semiconductor layer on a support structure, a metal electrode or a metal electrode on a semiconductor substrate having one or more layers, a structure or region formed thereon. The substrate material may be a conventional silicon substrate or other bulk substrate including layers of semiconductor material. As used herein, the term “bulk substrate” means and includes not only a silicon wafer, but also silicon-on-insulator (“SOI”) substrates, such as silicon-on-sapphire (“SOS”) and silicon-on-glass (“SOG”) substrates, epitaxial layers of silicon on a substrate semiconductor basis, and other semiconductor or optoelectronic materials, such as silicon-germanium, germanium, gallium arsenide, gallium nitride, and indium phosphide. The substrate material may be doped or undoped. In some embodiments, the wafer includes a silicon wafer, such as a bare silicon wafer (e.g., a dummy silicon wafer, which may also be referred to as a test wafer). In other embodiments, the wafer includes a test wafer, a recycled wafer, a portion of a wafer (e.g., a wafer sample), or a film.

[0042] For example, microelectronic device manufacturing tools may include one or more of the following: etching tools (e.g., wet etching tools, dry etching tools (e.g., reactive ion etching (RIE) tools)), deposition tools (e.g., ALD tools, CVD tools, PVD tools, PECVD tools, PEALD tools, LPCVD, another deposition tool), ion implantation tools, chemical mechanical planarization (CMP) tools, annealing chambers, or another tool.

[0043] In some embodiments, a wafer is disposed within a manufacturing tool. The manufacturing tool may contain one or more contaminants. For example, the manufacturing tool may contain materials from previous manufacturing operations, such as one or more metals, nonmetals, or semi-metals. Such materials may undesirably contaminate the microelectronic device placed in the manufacturing tool during other manufacturing operations. In some embodiments, the manufacturing tool may contain one or more materials (e.g., aluminum) on its walls that may volatilize during various manufacturing operations. As will be described herein, the wafer can be used to determine the presence of one or more contaminants within the manufacturing tool and the composition of such contaminants.

[0044] Action 204 includes exposing the wafer to one or more processing conditions within a manufacturing tool. For example, the wafer may be exposed to conditions substantially similar to those exposed to other wafers to be placed in the manufacturing tool. In some embodiments, the wafer may be exposed to environmental conditions (e.g., ambient temperature and pressure) within the manufacturing tool. In other embodiments, the wafer is exposed to temperatures ranging from about 0°C to about 400°C, for example from about 0°C to about 20°C, from about 20°C to about 50°C, from about 50°C to about 100°C, from about 100°C to about 200°C, from about 200°C to about 300°C, or from about 300°C to about 400°C. The wafer may be exposed to pressures ranging from about 10 kPa to about 700 kPa, for example, from about 10 kPa to about 50 kPa, from about 50 kPa to about 100 kPa, from about 100 kPa to about 200 kPa, from about 200 kPa to about 300 kPa, from about 300 kPa to about 400 kPa, from about 400 kPa to about 500 kPa, from about 500 kPa to about 600 kPa, or from about 600 kPa to about 700 kPa. In some embodiments, the wafer is exposed to one or more deposition conditions, or one or more materials may be formed in a manufacturing tool (e.g., deposited on the wafer) in the presence of the wafer.

[0045] Action 206 includes exposing the wafer to an aerosol comprising an oxidant to form an oxide on at least some surfaces of the wafer. In some embodiments, the wafer is moved from a manufacturing tool to another tool, where the wafer is exposed to the oxidant. The oxidant may include one or more of the materials described above with reference to liquid source 112. In some embodiments, the oxidant includes hydrogen peroxide, such as about 30% by weight of hydrogen peroxide. For example, the oxide may include one or more of silicon dioxide, selenium oxide (e.g., selenium dioxide), tellurium oxide (e.g., tellurium dioxide), germanium oxide (germanium dioxide), metal oxides, and oxides of phosphorus. In some embodiments, the oxide formed on the wafer includes silicon dioxide. In other embodiments, the oxide includes one or more of selenium oxide, tellurium oxide, germanium oxide, and silicon dioxide. In other embodiments, the oxide includes one or more of the following metal oxides: aluminum oxide, titanium oxide, vanadium oxide, chromium oxide, manganese oxide, cobalt oxide, nickel oxide, zinc oxide, gallium oxide, zirconium oxide, niobium oxide, ruthenium oxide, rhodium oxide, palladium oxide, cadmium oxide, hafnium oxide, tantalum oxide, tungsten oxide, osmium oxide, iridium oxide, or platinum oxide. In other embodiments, the oxide may comprise an oxide of phosphorus.

[0046] According to an embodiment of the present invention, Figure 3 A simplified diagram illustrating the tool 300 configured to perform action 206. (See diagram below.) Figure 3 As shown, tools 300 include Figure 1 The atomizer 100 is configured to expose a wafer 308 to an aerosol comprising an oxidant. The tool 300 may also be referred to as a "wafer scanning tool". The tool 300 may include a chamber 302 containing a base 304, a chuck 306 (e.g., an electrostatic chuck) mounted on the base 304, and a wafer 308 on the chuck 306. The base 304, the chuck 306, or both may be configured to rotate along an axis 314 to rotate the wafer 308. The tool 300 may be configured to expose the wafer 308 to an oxidant to form an oxide on the wafer 308.

[0047] The tool 300 may further include an arm 310 configured to move along the surface of the wafer 308 during use and operation of the tool 300. The arm 310 may be configured to move in the x-direction (in... Figure 3 In the view, to the left and right), y-direction (in) Figure 3 Entering and exiting the page in the view) and the z-direction (in the view) Figure 3 (Up and down in the view). In some embodiments, arm 310 is configured to move in a radial direction (e.g., the x and y directions).

[0048] Atomizer 100 may be coupled to arm 310, which may be configured to move atomizer 100 relative to the surface of wafer 308. Therefore, atomizer 100 may be configured to move along the surface of wafer 308, for example, in the x and y directions. Additionally, atomizer 100 may be configured to move toward and away from the surface of wafer 100 by moving in the z direction to change the nozzle 108 (…). Figure 1 The distance D between the wafer 310 and the surface of the wafer 310.

[0049] Atomizer 100 can be coupled or configured to be coupled to a carrier gas, as shown in the reference above. Figure 1 Any of the carrier gases 114 described. The atomizer 100 may also be coupled to a liquid 112 ( Figure 1 The composition of liquid 112 can be selected based on the properties of wafer 308. For example, in some embodiments, forming an oxide on the surface of wafer 308 using one or more of the liquids 112 described above can convert a hydrophilic surface of wafer 308 to a hydrophobic surface in response to exposure to an aerosol including an oxidant. In some embodiments, exposing wafer 308 to an oxidant can lower the pH of the surface of wafer 308 and alter the surface of wafer 308 to exhibit hydrophobic properties. As will be described herein, a surface exhibiting hydrophobic properties can facilitate improved scanning of wafer 308.

[0050] Nozzle 108 ( Figure 1 The distance D between the wafer 308 and the surface of the wafer 308 can be in the range of about 5 mm to about 150 mm, for example, from about 5 mm to about 10 mm, from about 10 mm to about 20 mm, from about 20 mm to about 30 mm, from about 30 mm to about 40 mm, from about 40 mm to about 50 mm, from about 50 mm to about 75 mm, from about 75 mm to about 100 mm, from about 100 mm to about 125 mm, or from about 125 mm to about 150 mm. However, the invention is not limited thereto, and the distance D may differ from those described.

[0051] During use and operation, the atomizer 100 generates an aerosol comprising microdroplets of liquid 112, as shown in the reference above. Figure 1 As described. The atomizer 100 can direct aerosol to one or more portions of the wafer 308 to oxidize one or more portions of the wafer 308. The tool 300 can be configured to oxidize from one square centimeter (cm²) of atomized aerosol. 2 Approximately 0.1 μL of oxidant (μL / cm³) for wafer 308 2 Up to approximately 2.0 μL / cm 2 For example, from approximately 0.1 μL / cm 2 Up to approximately 0.2 μL / cm 2 From approximately 0.2 μL / cm 2 Up to approximately 0.3 μL / cm 2From approximately 0.3 μL / cm 2 Up to approximately 0.4 μL / cm 2 From approximately 0.4 μL / cm 2 Up to approximately 0.5 μL / cm 2 From approximately 0.5 μL / cm 2 Up to approximately 0.6 μL / cm 2 From approximately 0.6 μL / cm 2 Up to approximately 0.8 μL / cm 2 From approximately 0.8 μL / cm 2 Up to approximately 1.0 μL / cm 2 From approximately 1.0 μL / cm 2 Up to approximately 1.5 μL / cm 2 Or from approximately 1.5 μL / cm 2 Up to approximately 2.0 μL / cm 2 The wafer 308 is exposed to the liquid 112 at a rate within the range described. However, the invention is not limited thereto, and the liquid 112 may be supplied at rates different from those described.

[0052] In some embodiments, while guiding the aerosol toward the wafer 308, the wafer 308 rotates at a desired rate along axis 314. Arm 310 may move radially to distribute the aerosol onto a desired radial portion of the wafer 308 as it is rotated. In some embodiments, by moving arm 310 radially in conjunction with the rotation of the wafer 308, substantially all of the wafer 308 is exposed to the aerosol. In other embodiments, only a desired portion of the surface of the wafer 308 is contacted with the aerosol to form oxide only at the corresponding portion of the wafer 308 contacted by the aerosol. By way of non-limiting example, in some embodiments, arm 310 is moved to a desired radial distance from the center of the wafer 308 while rotating the wafer 308 to expose annular portions of the wafer 308 located at the desired radial distance from the center to the oxidant. In other embodiments, the wafer 308 may not rotate, and the desired portion of the wafer 308 may be exposed to the aerosol by moving arm 310 to form oxide only at the desired portion of the wafer 308.

[0053] Exposing wafer 308 to an oxidant 308 in the form of an aerosol can form an oxide on wafer 308. In some embodiments, the oxide comprises silicon dioxide. The thickness of the oxide can range from approximately To date For example, from the approx. To date From the agreement To date From the agreement To date From the agreement To date From the agreement To date From the agreement To date From the agreement To date Or from the agreement To date Within a certain range. In some embodiments, the thickness of the oxide is from approximately To date Within a certain range. In some embodiments, the thickness of the oxide is from approximately To date For example, from the approx. To date Within a certain range. The thickness of the oxide can depend at least in part on the composition and concentration of the oxidant in the aerosol. For example, in some embodiments, reducing the concentration of the oxidant in the aerosol can reduce the thickness of the oxide compared to embodiments in which the oxidant concentration is increased.

[0054] The temperature of the tool 300, wafer 308, and aerosol can be in the range of about 0°C to about 50°C, for example, from about 0°C to about 15°C, from about 15°C to about 20°C, from about 20°C to about 25°C, from about 25°C to about 30°C, from about 30°C to about 40°C, or from about 40°C to about 50°C. In some embodiments, the temperature of the tool 300, wafer 308, and aerosol is in the range of about 15°C to about 20°C.

[0055] Exposing wafer 308 to an aerosol using tool 300 promotes the exposure of wafer 308 to liquid 112 in a substantially uniform manner to form a substantially uniform oxide on the surface of wafer 308. Additionally, the use of atomizer 100 and aerosol reduces the likelihood of introducing contaminants to wafer 308 via the oxidant. For example, in some embodiments, the entire surface of wafer 308 may be exposed to an aerosol and oxidant containing less than about 1.0 mL of oxidant. By comparison, conventional methods for forming oxides involve, for example, immersing wafer 308 in a bath containing an oxidant. However, such methods expose wafer 308 to contaminants present in the oxidant. Furthermore, exposing wafer 308 to a relatively small volume of oxidant reduces the likelihood that the oxidant will wash away surface features of wafer 308 or remove contaminants from the surface of wafer 308 or reposition them to other locations. Moreover, forming oxides with an aerosol allows the oxide to be formed to have the same thickness as oxides formed by immersing wafer 308 in a liquid oxidant or spraying wafer 308 with a liquid oxidant.

[0056] In some embodiments, forming oxides with an aerosol can facilitate the formation of oxides only on a portion (e.g., less than all) of the surface of wafer 308. In other words, because the oxides are formed using an aerosol, rather than by immersing wafer 308 in a liquid oxidant or spraying a liquid oxidant onto wafer 308, oxides can be formed only at desired locations on wafer 308. By comparison, immersing wafer 308 in a liquid bath comprising an oxidant can oxidize the entire surface of wafer 308, and can also oxidize the front and rear surfaces of wafer 308.

[0057] Refer again Figure 2 Action 208 may include exposing oxide to an etchant to remove oxide from at least some surfaces of wafer 308. In some embodiments, action 208 includes performing vapor phase decomposition (VPD) to remove oxide. The etchant may be formulated to remove oxide without substantially removing underlying portions of wafer 308, such as silicon underlying the oxide. In some embodiments, wafer 308 may be moved from tool 300 to another tool to expose wafer 308 to the etchant. In some embodiments, contaminants present within the silicon of wafer 308 are exposed and can be collected and analyzed in response to the exposure of wafer 308 to the etchant.

[0058] For example, the etchant may include one or more of hydrogen fluoride (HF) gas (also known as hydrofluoric acid vapor), hydrochloric acid, citric acid, acetic acid, aminosulfonic acid (H3NSO3), nitric acid (HNO3), or another acid. In some embodiments, the etchant includes hydrogen fluoride vapor. Hydrogen fluoride may react with silicon dioxide to form one or more of silicon tetrafluoride (SiF4) gas, sulfur hexafluoride (SiF6) gas, or fluorosilicic acid (H2SiF6). In some embodiments, the etchant removes substantially all oxides from the surface of wafer 308, while any contaminants that were present in the oxides and / or silicon remain on the surface of wafer 308. In some embodiments, the surface of wafer 308 may become hydrophobic in response to exposure to the etchant.

[0059] Action 210 includes introducing droplets of scanning solution onto the surface of wafer 308 and scanning the surface of wafer 308 with said droplets. As used herein, “scanning” wafer 308 with droplets signifies moving the droplets across the surface of wafer 308 to bring the surface into contact with the scanning solution. The scanning solution can dissolve at least one contaminant present on the surface of wafer 308. In some embodiments, the droplets are moved along substantially all of the surface of wafer 308. In some such embodiments, arm 310 may be positioned above the droplets and the wafer 308 may be rotated as arm 310 moves in the radial direction. In some embodiments, the surface of wafer 308 may exhibit hydrophilic properties and generally repel droplets comprising hydrophilic materials. As arm 310 moves in the radial direction, the droplets may remain below arm 310 and move in the radial direction along the same path as arm 310. In some embodiments, the droplets remain below arm 310 due to the hydrophobicity of the surface of wafer 308; however, the invention is not limited thereto. In other embodiments, wafer 308 may be scanned manually. In some such embodiments, instead of rotating the wafer 308, the wafer 308 is tilted back and forth so that the main surface of the wafer 308 is positioned at an angle with respect to the Earth's gravitational field, so that the droplet moves along the surface of the wafer 308.

[0060] In some embodiments, different sectors of wafer 308 are scanned with droplets. In some such embodiments, a first liquid droplet is disposed on the surface of wafer 308 and contacts the surface of wafer 308 within a specific radial distance from the center of wafer 308. For example, arm 310 may be moved from the center of wafer 308 to a first radial distance from the center so that a portion of wafer 308 between the center and the first radial distance contacts the first liquid droplet. Thereafter, as described with reference to action 212, the first liquid droplet may be collected for analysis. A second liquid droplet may be disposed on the surface of wafer 308 between a first radial distance and a second radial distance positioned further from the center of wafer 308 than the first radial distance. When wafer 308 is rotated, arm 310 may move between the first radial distance and the second radial distance so that a surface of wafer 308 between the first radial distance and the second radial distance contacts the second liquid droplet. Thereafter, as described with reference to action 212, the second liquid droplet may be collected for analysis. The process can be repeated for different radial segments of wafer 308 so that different annular portions of wafer 308 come into contact with different droplets, which can be analyzed to obtain a contamination map of wafer 308.

[0061] The scanning solution may include hydrofluoric acid, nitric acid, hydrochloric acid, sulfuric acid, hydrogen peroxide, aqua regia (a mixture of nitric acid and hydrochloric acid), a mixture of hydrofluoric acid and hydrogen peroxide, a mixture of nitric acid and hydrogen peroxide, a mixture of sulfuric acid and hydrogen peroxide, or a mixture of ammonium hydroxide, hydrogen peroxide, and water. For example, the composition of the scanning solution may depend on the composition of one or more contaminants to be identified. For instance, if testing for the presence of boron on wafer 308, the acid may include hydrofluoric acid, such as 1% by weight. In cases where the contaminant includes gold, the acid may contain hydrated acetal (HNO3 and HCl). If the contaminant contains tungsten, aluminum, or both, the scanning solution may contain SC1.

[0062] A scan solution containing one or more contaminants can be collected into a sample vial for analysis. Action 212 includes the analysis of a droplet of the scan solution against one or more contaminants. In some embodiments, the scan solution is removed from the surface of wafer 308, for example, using a pipette. Tool 300 may include an arm coupled to a pipette configured to remove the scan solution from wafer 308. The droplet is analyzed against one or more of the presence, composition, and concentration of one or more contaminants. In some embodiments, the arm of the pipette is operatively connected to an analytical tool for determining one or more properties of the droplet.

[0063] In some embodiments, droplets of a scanning solution are introduced into an analytical tool to determine one or more properties of the droplets. For example, droplets can be analyzed in an inductively coupled plasma mass spectrometry (ICP-MS) tool. An ICP-MS tool couples an inductively coupled plasma ionization source to a mass spectrometer. In some embodiments, droplets can be passed through a nebulizer to generate an aerosol. The aerosol can be injected into a high-temperature atmospheric pressure plasma obtained by coupling radio frequency (RF) energy to a flowing plasma stream. The flowing plasma may include, for example, argon plasma. The microdroplets of the atomized droplets are atomized to a sufficiently small size and, as the aerosol flows through the argon plasma, the sample is vaporized, atomized, and ionized. The resulting plasma, containing the ionized sample components, is extracted into a vacuum, where the ions are separated from neutral species and subjected to mass analysis. As an example, ions are introduced into a mass spectrometer coupled to an inductively coupled plasma source. The mass spectrometer can separate the ions generated in the inductively coupled plasma based on their mass-to-charge ratio and direct them to a detector for measurement and quantification.

[0064] Although action 212 has been described as including analysis of the droplets using inductively coupled plasma mass spectrometry, the invention is not limited thereto. In other embodiments, action 212 includes analyzing the droplets of the scanning solution using other trace element analysis methods, such as atomic absorption spectrometry (AAS). In other embodiments, the droplets are dried on the surface of a wafer, and the residues are analyzed by one or more of total internal reflection X-ray fluorescence (TXRF), synchrotron radiation total internal reflection X-ray fluorescence, or another method.

[0065] Method 200 and tool 300 can be used to detect one or more contaminants that may be present during the manufacturing process of various microelectronic devices. For example, such contaminants may include lithium, beryllium, boron, sodium, magnesium, aluminum, phosphorus, sulfur, chlorine, potassium, calcium, scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, gallium, germanium, arsenic, selenium, bromine, strontium, yttrium, zirconium, niobium, molybdenum, ruthenium, rhodium, palladium, silver, cadmium, indium, tin, antimony, tellurium, tellurium, cesium, barium, hafnium, tantalum, tungsten, iridium, platinum, gold, thallium, lead, bismuth, lanthanum, cerium, praseodymium, samarium, and dysprosium.

[0066] Therefore, in some embodiments, a contaminant detection method includes exposing a wafer containing one or more contaminants to droplets of an oxidant to form an oxide on the surface of the wafer, exposing the oxide to an etchant to remove the oxide and leave the one or more contaminants on the surface of the wafer, and determining the composition of the one or more contaminants.

[0067] Furthermore, in some embodiments, a method for detecting contaminants includes: atomizing an oxidant to form an aerosol, exposing a wafer to the aerosol to form an oxide on the wafer surface, exposing the oxide to an etchant to remove the oxide, contacting the surface of the wafer with at least one droplet of a scanning solution to dissolve the material in the at least one droplet, and analyzing the at least one droplet of the material.

[0068] Furthermore, in some embodiments, a contaminant detection tool includes: a chuck configured to receive a wafer, the chuck being configured to rotate at an angle; an arm configured to move about a surface of the chuck; and an atomizer coupled to the arm and in fluid communication with an oxidant and a carrier gas, the atomizer being configured to generate an aerosol comprising droplets of the oxidant.

[0069] Additionally, in some embodiments, a method includes placing a wafer on a wafer chuck of a tool including an atomizer in fluid communication with an oxidant and a carrier gas, forming an aerosol comprising droplets of the oxidant and the carrier gas, and exposing the surface of the wafer to the aerosol to form an oxide on the surface of the wafer.

[0070] Additional non-limiting examples of the present invention are described below.

[0071] Example 1: A method for detecting contaminants, comprising: exposing a wafer containing one or more contaminants to droplets of an oxidant to form an oxide on the surface of the wafer; exposing the oxide to an etchant to remove the oxide and leave the one or more contaminants on the surface of the wafer; and determining the composition of the one or more contaminants.

[0072] Example 2: According to the method of Example 1, exposing a wafer containing one or more contaminants to droplets includes forming an aerosol containing the microdroplets including the oxidant and exposing the wafer to the aerosol.

[0073] Example 3: The method according to Example 1 or Example 2, wherein exposing a wafer containing one or more contaminants to droplets includes forming an aerosol containing droplets of hydrogen peroxide using an atomizer.

[0074] Example 4: According to the method of Example 3, the aerosol comprising hydrogen peroxide droplets is formed by using a carrier gas comprising one or more of argon and nitrogen.

[0075] Example 5: The method according to any one of Examples 1 to 4, wherein exposing a wafer containing one or more contaminants to droplets of an oxidant to form an oxide includes forming the oxide to give it a state of flux from approximately To date The thickness is within the range.

[0076] Example 6: The method according to any one of Examples 1 to 5, wherein exposing a wafer containing one or more contaminants to droplets of an oxidant comprises exposing the wafer to one or more materials selected from the group consisting of hydrogen peroxide, water, ammonia, nitric acid, sulfuric acid, perchloric acid and hydrofluoric acid.

[0077] Example 7: The method according to any one of Examples 1 to 6, wherein exposing a wafer containing one or more contaminants to droplets of an oxidant comprises exposing the wafer to a concentration of the oxidant ranging from about 0.1 μL to about 0.2 μL per square centimeter of the wafer.

[0078] Example 8: The method according to any one of Examples 1 to 7, wherein exposing the oxide to the etchant includes exposing the oxide to a vapor including hydrogen fluoride.

[0079] Example 9: The method according to any one of Examples 1 to 8, wherein determining the composition of the one or more contaminants includes exposing the wafer to a scanning solution prepared to dissolve the one or more contaminants.

[0080] Example 10: The method according to Example 9, wherein exposing the wafer to the scanning solution includes contacting substantially all surfaces of the wafer with the scanning solution.

[0081] Example 11: The method according to Example 9 or Example 10, wherein exposing the wafer to the scanning solution includes placing droplets of the scanning solution on the wafer and rotating the wafer.

[0082] Example 12: The method according to Example 11, wherein determining the composition of the one or more contaminants includes analyzing the droplets of the scanning solution by inductively coupled plasma mass spectrometry.

[0083] Example 13: The method according to any of Examples 1 to 12, wherein exposing a wafer comprising one or more contaminants to droplets of an oxidant to form an oxide on the surface of the wafer comprises exposing a wafer comprising silicon to the droplets of the oxidant to form silicon dioxide on the surface of the wafer.

[0084] Example 14: A method for detecting at least one contaminant, comprising: atomizing an oxidant to form an aerosol; exposing a wafer to the aerosol to form an oxide on the wafer surface; exposing the oxide to an etchant to remove the oxide; contacting the surface of the wafer with at least one droplet of a scanning solution to dissolve the material in the at least one droplet; and analyzing the at least one droplet of the material.

[0085] Example 15: The method according to Example 14, wherein the atomizing oxidant comprises atomizing a solution comprising from about 1% by weight to about 35% by weight of hydrogen peroxide.

[0086] Example 16: The method according to Example 14 or Example 15, wherein atomizing the oxidant to form an aerosol and exposing at least a portion of the wafer to the aerosol to form oxides on at least some surfaces of the wafer includes forming the aerosol with the oxidant at a rate from about 10 μL / min to about 400 μL / min.

[0087] Example 17: The method according to any of Examples 14 to 16, wherein contacting the surface of the wafer with at least one droplet of the scanning solution comprises depositing the at least one droplet of the scanning solution onto the wafer and rotating the wafer together with the at least one droplet on the wafer.

[0088] Example 18: The method according to any of Examples 14 to 17, wherein contacting the surface of the wafer with at least one droplet of the scanning solution comprises contacting the surface of the wafer with at least one droplet of one or more of hydrofluoric acid, nitric acid, hydrochloric acid, sulfuric acid, hydrogen peroxide, aqua regia and ammonium hydroxide.

[0089] Example 19: A contaminant detection tool comprising: a chuck configured to receive a wafer, the chuck being configured to rotate at an angle; an arm configured to move about a surface of the chuck; and an atomizer coupled to the arm and in fluid communication with an oxidant and a carrier gas, the atomizer being configured to generate an aerosol comprising droplets of the oxidant.

[0090] Example 20: The tool according to Example 19, wherein the oxidant comprises hydrogen peroxide.

[0091] Example 21: The tool according to Example 19 or Example 20 further includes an inductively coupled plasma mass spectrometer coupled to the tool.

[0092] Example 22: The tool according to any one of Examples 19 to 21, wherein the atomizer comprises a fluoropolymer.

[0093] Example 23: A method comprising: placing a wafer on a wafer chuck of a tool including an atomizer in fluid communication with an oxidant and a carrier gas; forming an aerosol comprising droplets of the oxidant and the carrier gas; and exposing the surface of the wafer to the aerosol to form an oxide on the surface of the wafer.

[0094] Example 24: The method according to Example 23 further includes rotating the wafer chuck while exposing the surface of the wafer to the aerosol.

[0095] Example 25: The method according to Example 23 or Example 24, wherein forming an aerosol comprising droplets of the oxidant comprises forming an aerosol comprising droplets of hydrogen peroxide.

[0096] Example 26: The method according to any one of Examples 23 to 25, wherein forming an oxide on the surface of the wafer includes forming an oxide on the surface of the wafer having a shape that is approximately... To date Oxides within a certain range of thickness.

[0097] Although certain illustrative embodiments have been described in conjunction with the drawings, those skilled in the art will recognize and understand that the embodiments covered by this invention are not limited to those explicitly shown and described herein. Rather, many additions, deletions, and modifications can be made to the embodiments described herein without departing from the scope of the embodiments covered by this invention, such as those claimed below, including legal equivalents. Furthermore, features from one disclosed embodiment may be combined with features from another disclosed embodiment while still being covered within the scope of this invention.

Claims

1. A pollutant detection tool, comprising: A chuck configured to receive a wafer, the chuck being configured to rotate at an angle; An arm configured to move about the surface of the chuck; and An atomizer, coupled to the arm and in fluid communication with an oxidant and a carrier gas, is configured to generate an aerosol comprising microdroplets of the oxidant to form an oxide on the surface of the wafer, the distance between the atomizer and the wafer being in the range of 5 mm to 150 mm.

2. The pollutant detection tool according to claim 1, wherein the oxidant comprises hydrogen peroxide.

3. The pollutant detection tool according to claim 1, further comprising an inductively coupled plasma mass spectrometer coupled to the tool.

4. The pollutant detection tool according to claim 1, wherein the atomizer comprises a fluoropolymer.

5. The contaminant detection tool according to claim 1, wherein the oxidant comprises 25% by weight to 35% by weight hydrogen peroxide.

6. The contaminant detection tool of claim 1, wherein the atomizer includes a capillary extending from a liquid inlet port to a nozzle, the capillary being configured to facilitate the flow of the oxidant from the liquid inlet port to the nozzle.

7. The contaminant detection tool of claim 6, wherein the atomizer includes a gas inlet port extending substantially perpendicular to the liquid inlet port.

8. The contaminant detection tool according to claim 6, wherein the capillary has a diameter in the range of 0.15 mm to 0.25 mm.

9. The contaminant detection tool of claim 1, wherein the atomizer is configured to provide the oxidant at a flow rate in the range of 10 μL / min to 50 μL / min.

10. The contaminant detection tool of claim 1, wherein the atomizer is configured to generate the aerosol, the aerosol comprising droplets with an average volume in the range of 0.01 μL to 1.0 μL.

11. The contaminant detection tool of claim 1, wherein the arm is configured to move in both radial and vertical directions.

12. A method for using a contaminant detection tool, the method comprising: The wafer is placed on the wafer chuck of the tool, which includes an atomizer in fluid communication with an oxidant and a carrier gas. Aerosols are formed comprising microdroplets of the carrier gas and the oxidant; The surface of the wafer is exposed to the aerosol to form an oxide on the surface of the wafer; and After the oxide is formed, the surface of the wafer is scanned with a scanning solution to determine the presence of one or more contaminants on the surface of the wafer.

13. The method of claim 12, further comprising rotating the wafer chuck while exposing the surface of the wafer to the aerosol.

14. The method of claim 12, wherein forming an aerosol comprising droplets of the oxidant comprises forming an aerosol comprising droplets of hydrogen peroxide.

15. The method of claim 12, wherein forming an oxide on the surface of the wafer comprises forming an oxide having a thickness in the range of 1 Å to 25 Å on the surface of the wafer.

16. The method of claim 12, wherein determining the presence of one or more contaminants on the surface of the wafer comprises determining the presence of one or more of boron, gold, tungsten, and aluminum on the surface of the wafer.

17. The method of claim 12, wherein exposing the surface of the wafer to the aerosol to form an oxide on the surface of the wafer comprises forming silicon dioxide on the surface of the wafer.

18. The method of claim 12, wherein exposing the surface of the wafer to the aerosol to form an oxide on the surface of the wafer comprises converting a hydrophilic surface of the wafer into a hydrophobic surface.

19. The method of claim 12, wherein exposing the surface of the wafer to the aerosol to form an oxide on the surface of the wafer comprises lowering the pH of the surface of the wafer.

20. The method of claim 12, wherein exposing the surface of the wafer to the aerosol to form an oxide on the surface of the wafer comprises exposing the surface of the wafer to an oxidant of 0.1 μL to 0.2 μL per square centimeter of the wafer.

21. The method of claim 12, further comprising exposing the oxide to one or more etchants to remove the oxide from the surface of the wafer.

22. The method of claim 12, further comprising analyzing the scanning solution of the one or more contaminants.

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