Method and assembly for creating a molecular beam

Abstract

An inlet assembly includes an inlet flange, a first inlet portion coupled to the inlet flange and defining a first inlet chamber, and a second inlet portion coupled to the first inlet portion and defining a second inlet chamber. A first flow diverting element is positioned between the inlet flange and the first inlet portion. A second flow diverting element is positioned between the first inlet portion and the second inlet portion. The sample passes through the inlet flange and into the first inlet portion. The first flow diverting element diverts a portion of the sample into the first inlet chamber and conducts a remaining portion of the sample into the second inlet portion. The second flow diverting element diverts a portion of the sample entering the second inlet portion into the second inlet chamber and conducts a remaining portion of the sample through the second inlet portion.

Description

METHOD AND ASSEMBLY FOR CREATING A MOLECULAR BEAMCROSS-REFERENCE TO RELATED APPLICATION

[0001] This application is related, and claims priority to, commonly-owned Provisional Patent Application Serial No.: 63 / 540,438, filed September 26, 2023, having the same title. The entire contents of said application is incorporated by reference as if disclosed herein in its entirety.TECHNOLOGICAL FIELD

[0002] This invention relates generally to the field of neutral radical mass spectrometry. Specifically, the following disclosure is directed to an apparatus that delivers a high fidelity sample from a volume of gas to a mass spectrometer while minimally affecting the composition of the sample. In the embodiments described, the apparatus comprises an inlet assembly.BACKGROUND

[0003] Molecular beam mass spectrometry is an analytical technique used to measure reactive species in a sample. Such measurements may be used to determine the exact molecular weights and relative concentrations of the sample components. Preserving the sample as it is transported from the sample environment, such as a process chamber, to the mass spectrometer is a challenge for samples containing chemically unstable molecules, such as neutral radicals. A current solution to this problem is to use a long capillary or orifice to create a molecular beam. However, the long capillary does not work for a sample comprising one or more neutralradicals. The neutral radicals in the sample will stick to the walls of the long capillary and recombine to diatomic species. This decreases the fidelity of the sample delivered to the ion source of the mass spectrometer. An orifice, on the other hand, destroys the properties of laminar flow and creates a turbulent environment, which also decreases the fidelity of the sample delivered to the ion source as the probability of the neutral radical molecules surviving long enough to be measured is very low.

[0004] These are just some of the problems associated with neutral radical mass spectrometry.SUMMARY

[0005] Aspects of the following disclosure are directed to embodiments of an inlet assembly for producing a laminar flow of a sample gas. In some embodiments, the inlet assembly includes an inlet flange defining a bore, a first inlet portion coupled to the inlet flange and defining an first inlet chamber, and a second inlet portion coupled to the first inlet portion and defining a second inlet chamber. In some embodiments, a first flow diverting element is positioned between the inlet flange and the first inlet portion and a second flow diverting element is positioned between the first inlet portion and the second inlet portion. In some embodiments, the sample gas passes through the bore of the inlet flange and into the first inlet portion where the first flow diverting element diverts a portion of the sample gas into the first inlet chamber. In some embodiments, the first flow diverting element conducts a remaining portion of the sample gas through the first inlet portion and into the second inlet portion. In some embodiments, the second flow diverting element diverts a portion of the sample gas entering the second inlet portion into the second inlet chamber and conducts a remaining portion of the sample gas through the second inlet portion as a molecularbeam.

[0006] In some embodiments of the inlet assembly, at least one of the first flow diverting element and the second flow diverting element includes an exterior surface that is concave. In some embodiments of the inlet assembly, the first flow diverting element and the second flow diverting element include a first end and a second end, wherein the first end includes an apex defining an apex opening into an inner space that extends to a base opening at the second end. Some embodiments of the inlet assembly further include a rim surrounding the base opening. In some embodiments of the inlet assembly, the first inlet chamber comprises an annular shape. In some embodiments of the inlet assembly, the second inlet chamber comprises an annular shape. In some embodiments of the inlet assembly, the molecular beam is directed to an ion source. In some embodiments of the inlet assembly, the first inlet chamber is connected to one or more pumping conduits that connect to a pumping device. In some embodiments of the inlet assembly, the second inlet chamber is connected to one or more pumping conduits that connect to a pumping device.

[0007] Aspects of the following disclosure are further directed to embodiments of a method of manufacturing an inlet assembly for producing a laminar flow of a sample gas. In some embodiments, the method includes structuring an inlet flange to define a bore traversing the inlet flange, structuring a first inlet portion to be coupled to the inlet flange and to define a first inlet chamber, and structuring a second inlet portion to be coupled to the first inlet portion and to define a second inlet chamber. In some embodiments, the method further includes structuring a first flow diverting element to be positioned between the inlet flange and the first inlet portion, and structuring a second flow diverting element to be positioned between the first inlet portion and the second inlet portion. In some embodiments, the method further includes structuring the bore ofthe inlet flange to enable the sample gas to pass through the inlet flange and into the first inlet portion. In some embodiments, the method further includes structuring the first flow diverting element to divert a portion of the sample gas into the first inlet chamber and to conduct a remaining portion of the sample gas through the first inlet portion and into the second inlet portion. In some embodiments, the method further includes structuring the second flow diverting element to divert a portion of the sample gas entering the second inlet portion into the second inlet chamber and to conduct a remaining portion of the sample gas through the second inlet portion as a molecular beam.

[0008] In some embodiments, the method further includes structuring at least one of the first flow diverting element and the second flow diverting element to include an exterior surface that is concave. In some embodiments, the method further includes structuring the first flow diverting element and the second flow diverting element to include a first end and a second end, and structuring the first end to include an apex defining an apex opening into an inner space that extends to a base opening at the second end. In some embodiments, the method further includes structuring the first flow diverting element and the second flow diverting element to include a rim surrounding the base opening.

[0009] In some embodiments, the method further includes structuring the first inlet chamber to comprise an annular shape. In some embodiments, the method further includes structuring the second inlet chamber to comprise an annular shape. In some embodiments, the method further includes directing the molecular beam to an ion source. In some embodiments, the method further includes structuring the first inlet chamber to connect to one or more pumping conduits that lead to a pumping device. In some embodiments, the method further includes structuring the second inlet chamber to connect to one or more pumping conduits that lead to apumping device.

[0010] Other aspects of the present disclosure are directed to embodiments of a gas analyzing system including a process chamber, a gas analyzer, and an inlet assembly positioned between the process chamber and the gas analyzer and structured to produce a laminar flow of a sample gas from the process chamber. In some embodiments, the inlet assembly includes an inlet flange defining a bore that extends into the process chamber, a first inlet portion coupled to the inlet flange and defining an first inlet chamber, and a second inlet portion coupled to the first inlet portion and defining a second inlet chamber. In some embodiments, a first flow diverting element is positioned between the inlet flange and the first inlet portion, and a second flow diverting element is positioned between the first inlet portion and the second inlet portion. In some embodiments, the sample gas passes from the process chamber into the first inlet portion via the bore of the inlet flange. In some embodiments, the first flow diverting element diverts a portion of the sample gas into the first inlet chamber and conducts a remaining portion of the sample gas through the first inlet portion and into the second inlet portion. In some embodiments, the second flow diverting element diverts a portion of the sample gas entering the second inlet portion into the second inlet chamber and conducts a remaining portion of the sample gas through the second inlet portion as a molecular beam that is conducted to the gas analyzer. In some embodiments of the gas analyzing system, the gas analyzer includes an ion source.BRIEF DESCRIPTION OF DRAWINGS

[0011] A more particular description of the invention briefly summarized above may be had by reference to the embodiments, some of which are illustrated in the accompanying drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for theinvention may admit to other equally effective embodiments. Thus, for further understanding of the nature and objects of the invention, references can be made to the following detailed description, read in connection with the drawings.

[0012] Fig. 1 illustrates an exploded perspective view of an embodiment of an inlet assembly.

[0013] Fig. 2 illustrates a partially exploded perspective view of an embodiment of an inlet assembly.

[0014] Fig. 3 illustrates a sectional view along a longitudinal axis of an embodiment of a flow diverting element.

[0015] Fig. 4 illustrates a perspective view of an embodiment of the inlet assembly in an assembled state.DETAILED DESCRIPTION

[0016] The following discussion relates to various embodiments of an inlet assembly for use with a gas analyzer or gas analyzing system. It will be understood that the herein described versions are examples that embody certain inventive concepts as detailed herein. To that end, other variations and modifications will be readily apparent to those of sufficient skill. In addition, certain terms are used throughout this discussion in order to provide a suitable frame of reference with regard to the accompanying drawings. These terms such as “upper”, “lower”, “forward”, “rearward”, “interior”, “exterior”, “front”, “back”, “top”, “bottom”, “inner”, “outer”, “first”, “second”, and the like are not intended to limit these concepts, except where so specifically indicated. The terms “about” or “approximately” as used herein may refer to a range of 80%-salient features of the inlet assembly and are not specifically provided to scale.

[0017] Figures 1-4 illustrate an embodiment of a laminar flow inlet assembly 100 for a gas analyzer or gas analyzing system. In some embodiments, the gas analyzing system comprises a mass spectrometer. In some embodiments, the inlet assembly 100 includes an inlet flange 110, a first inlet portion 130 and a second inlet portion 150. In some embodiments, a flow diverter or flow diverting element 170 is positioned between the inlet flange 110 and the first inlet portion 130, and between the first inlet portion 130 and the second inlet portion 150.

[0018] As shown in Figs. 1, 2 and 4, in some embodiments, the inlet flange 110 includes a first side 112 and an opposing second side 114. The first side 112 is structured to face and / or be positioned in a process chamber 20, (Fig. 4) of a gas analyzer, gas analyzing system or fabrication system. The first side 112 of the inlet flange 110 further includes a neck or a tubular extension 116 defining a bore 118 that traverses the inlet flange 110. The second side 114 of the inlet flange 110 defines a recess 113 such that the bore 118 extends between the tubular extension 116 and the recess 113. As shown, the recess 113 comprises a plurality of arcuate portions 115 positioned around the bore opening. In some embodiments, the inlet flange 110 may further define a plurality of openings 119 positioned around a perimeter of the inlet flange 110. In some embodiments, each of the plurality of openings 119 is structured to at least partially accept a fastener to couple the inlet flange 110 to the first inlet portion 130.

[0019] In some embodiments, the first inlet portion 130 includes a first side 132 structured to couple to the inlet flange 1 10, an opposing second side 134, and a first inlet portion bore 138 extending from the first side 132 to the second side 134. In some embodiments, the first inlet portion 130 further includes a first inlet chamber 136 defined between an outer first inlet wall 133 and an inner first inlet wall 135. As shown, the bore 138 is positioned radially inward fromthe outer first inlet wall 133 and the inner first inlet wall 135. The first inlet chamber 136 comprises a generally annular shape and may be fluidly and / or pneumatically coupled to one or more pumping devices, such as a roughing pump, via one or more pumping conduits 140. In some embodiments, the second side 134 of the first inlet portion 130 defines a recess 137 such that the first inlet portion bore 138 extends between the first side 132 and the recess 137 of the second side 134 of the first inlet portion 130. In some embodiments, the first inlet portion 130 further defines a plurality of openings 139 positioned around the perimeter of the first inlet portion 130. In some embodiments, each of the plurality of openings 139 is structured to align with the plurality of openings 119 of the inlet flange 110 and to at least partially accept a fastener. In some embodiments, the second side 134 of the first inlet portion 130 defines a recess 137 such that the bore 138 extends between the first side 132 and the recess 137 of the second side 134 of the first inlet portion 130.

[0020] In some embodiments, a flow diverter or flow diverting element 170 is positioned over an entrance to the first inlet portion bore 138 and between the first inlet portion 130 and the inlet flange 110. In some embodiments, one or more pumping conduits 140 are positioned radially outward from the flow diverting element 170. Referring specifically to the embodiment of Fig. 3, the flow diverting element 170 comprises an exterior surface that comprises a conical shape with concave sides 176. In some embodiments, the flow diverting element includes an apex 172 and an opposing base 174. The apex 172 defines an apex opening 171 into an inner space 178 that extends to a base opening 173. In some embodiments, the base 174 of the flow diverting element 170 may further include a rim 175 that surrounds and defines the base opening 173. In the assembled state, the apex 172 is structured to be positioned within the bore 118 of the inlet flange 110. In some embodiments, the flow diverting element 170 comprises a coating. Insome embodiment

[0021] In some embodiments, the second inlet portion 150 includes a first side 152 structured to couple to the second side 134 of the first inlet portion 130, a second side 154, and a bore 158 extending from the first side 152 to the second side 154. The second inlet portion 150 further includes a second inlet chamber 156 defined between an outer second inlet wall 153 and an inner second inlet wall 155. As shown, the bore 158 is positioned radially inward from the outer second inlet wall 153 and the inner second inlet wall 155. In some embodiments, the second inlet chamber 156 comprises an annular shape and may be fluidly or pneumatically coupled to one or more pumping devices, such as a turbo pump, via one or more pumping conduits 180. In some embodiment, the second inlet portion 150 further defines a plurality of openings 159 positioned around the perimeter of the second inlet portion 150. In some embodiments, each of the plurality of openings 159 is structured to align with the plurality of openings 119 of the inlet flange 110 and the plurality of openings 139 of the first inlet portion 130, and are further structured to at least partially accept a fastener. In this manner the inlet flange 110, the first inlet portion 130, and the second inlet portion 150 are coupled together. In some embodiments, the second inlet portion 150 may be positioned near an ion source 200 of the gas analyzing system 10 or the ion source 200 may be at least partially positioned within the second inlet portion 150.

[0022] In some embodiments, another flow diverter or flow diverting element170 is positioned over the entrance to the bore 158 of the second inlet portion 150 and between the second inlet portion 150 and the first inlet portion 130. This flow diverting element 170 is the same as was previously described and has an apex structured to be positioned within the bore 138 of the first inlet portion 130. In some embodiments, the flow diverting element 170 is structured and positioned such that the one or more pumping conduits 180 are positioned radially outwardfrom the flow diverting element 170.

[0023] Referring to Fig. 4, a portion of an embodiment of a gas analyzing system 10 is shown connected to an embodiment of a process chamber 20, which is further connected to a pump in order to regulate the pressure of the process chamber 20. The arrows indicate a flow of sample process gas from the process chamber 20 into and through the inlet assembly 100. The sample process gas is initially drawn from the process chamber 20 into the inlet assembly 100 through the tubular extension 116 of the inlet flange 110. In some embodiments, the process gas moves through the bore 118 of the inlet flange 110 to the first flow diverting element 170a. In some embodiments, a portion of the process gas sample is directed through the first flow diverting element 170a and into the bore 138 of the first inlet portion 130 and the remainder of the process gas sample is diverted into the first inlet chamber 136. In some embodiments, the sample process gas in the bore 138 is directed through the first inlet portion 130 and to the second inlet portion 150. In some embodiments, another portion of the process gas sample is directed though the second flow diverting element 170b of the second inlet portion 150 and into the bore 158. The remaining process gas sample is diverted into the second inlet chamber 156. The process gas sample directed into the bore 158 is ten directed to the ion source 200 as a “molecular beam” 190.

[0024] Accordingly, the disclosed inlet assembly 100 vastly improves neutral radical delivery to the ion source 200 by maintaining an environment that supports laminar flow conditions to create the molecular beam 190. This is accomplished because the process gas sample is conducted through the inlet assembly 100 at a very high flow rate, for example at about 9.9 L / s, around the first diverting element 170a and at a slower rate, about 0.1 L / s, through the first diverting element 170a. The first and second flow diverting elements 170a, 170b are structured and positioned within the inlet assembly 100 in order to minimize flow turbulence while theprocess gas sample interacts with the surface of the first and second flow diverting elements 170a, 170b. This keeps the process gas sample from being disturbed prior to entering the second inlet portion 150 of the inlet assembly 100. Accordingly, recombination of radicals, such as fluorine and hydrogen, is inhibited or at least greatly minimized. Because the inlet assembly 100 enables the sample process gas to flow through it so quickly, no volume of the sample process gas resides in the flow path for a long enough period of time in areas where recombination of neutral radicals can occur. As can be seen in the figures, the unique geometries of the inlet assembly 100 components and the pumping of the sample gas promotes laminar flow and then takes advantage of such laminar flow properties to create the molecular beam 190. The aerodynamics of the disclosed inlet assembly 100 minimizes sample process gas turbulence as compared to a traditional inlet in order to protect the constituents of the process gas sample from reacting in the gas phase and on surfaces of the inlet assembly 100.

[0025] In some embodiments, one or more of the components of the inlet assembly 100 may be comprised of a metal, which may further include one or more coatings. In an embodiment, more than one metal may be used to comprise the inlet assembly 100. In some embodiments, the inlet flange 110, the first inlet portion 130 and the second inlet portion 150 may be comprised of a first metal and the first and second flow diverting elements 170a, 170b may be comprised of a second metal. In an exemplary embodiment, the inlet flange 110, the first inlet portion 130 and the second inlet portion 150 may be comprised of 304L stainless steel and the first and second flow diverting elements 170a 170b may be comprised of nickel, such as pure nickel. In some embodiments, the first inlet portion 130, the second inlet portion 150 and the first and second flow diverting elements 170a, 170b comprise a coating. In some embodiments, the coating comprises aluminum oxide or gold. In some embodiments, the coating comprises a thickness ofabout 250 nm. In some embodiments, the coating reduces the rate of reaction with the chemistry that is not conveyed through the molecular beam.

[0026] While the present invention has been particularly shown and described with reference to certain exemplary embodiments, it will be understood by one skilled in the art that various changes in detail may be effected therein without departing from the spirit and scope of the invention that can be supported by the written description and drawings. Further, where exemplary embodiments are described with reference to a certain number of elements, it will be understood that the exemplary embodiments can be practiced utilizing either less than or more than the certain number of elements. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprise” (and any form of comprise, such as “comprises” and “comprising”), “have” (and any form of have, such as “has” and “having”), “include” (and any form of include, such as “includes” and “including”), and “contain” (and any form of contain, such as “contains” and “containing”) are open-ended linking verbs. As a result, a method or device that “comprises,” “has,” “includes,” or “contains” one or more steps or elements possesses those one or more steps or elements, but is not limited to possessing only those one or more steps or elements. Likewise, a step of a method or an element of a device that “comprises,” “has,” “includes,” or “contains” one or more features possesses those one or more features, but is not limited to possessing only those one or more features. Furthermore, a device or structure that is configured in a certain way is configured in at least that way, but may also be configured in ways that are not listed.

[0027] The corresponding structures, materials, acts, and equivalents of all meansor step plus function elements in the claims below, if any, are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description set forth herein has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the disclosure. The embodiment was chosen and described in order to best explain the principles of one or more aspects set forth herein and the practical application, and to enable others of ordinary skill in the art to understand one or more aspects as described herein for various embodiments with various modifications as are suited to the particular use contemplated and in accordance with the following appended claims. Additional embodiments include any one of the embodiments described above and described in any and all exhibits and other materials submitted herewith, where one or more of its components, functionalities or structures is interchanged with, replaced by or augmented by one or more of the components, functionalities or structures of a different embodiment described above.

Claims

CLAIMS1. An inlet assembly for producing a laminar flow of a sample gas, comprising: an inlet flange defining a bore; a first inlet portion coupled to the inlet flange and defining an first inlet chamber; a second inlet portion coupled to the first inlet portion and defining a second inlet chamber; a first flow diverting element positioned between the inlet flange and the first inlet portion; and a second flow diverting element positioned between the first inlet portion and the second inlet portion, wherein the sample gas passes through the bore of the inlet flange and into the first inlet portion, wherein the first flow diverting element diverts a portion of the sample gas into the first inlet chamber and conducts a remaining portion of the sample gas through the first inlet portion and into the second inlet portion, wherein the second flow diverting element diverts a portion of the sample gas entering the second inlet portion into the second inlet chamber and conducts a remaining portion of the sample gas through the second inlet portion as a molecular beam.

2. The inlet assembly of claim 1, wherein at least one of the first flow diverting element and the second flow diverting element includes an exterior surface that is concave.

3. The inlet assembly of claim 1, wherein the first flow diverting element and the second flow diverting element include a first end and a second end, wherein the first end includes an apex defining an apex opening into an inner space that extends to a base opening at the second end.

4. The inlet assembly of claim 1, wherein the first and second flow diverting elements and inlet portions comprise a coating configured to reduce a rate of reaction with a chemistry that is not conveyed through the molecular beam.

5. The inlet assembly of claim 1, wherein the first inlet chamber comprises an annular shape.

6. The inlet assembly of claim 5, wherein the second inlet chamber comprises an annular shape.

7. The inlet assembly of claim 1, wherein the molecular beam is directed to an ion source.

8. The inlet assembly of claim 1, wherein the first inlet chamber is connected to one or more pumping conduits that connect to a pumping device.

9. The inlet assembly of claim 8, wherein the second inlet chamber is connected to one or more pumping conduits that connect to a pumping device.

10. A method of manufacturing an inlet assembly for producing a laminar flow of a sample gas, the method comprising: structuring an inlet flange to define a bore traversing the inlet flange; structuring a first inlet portion to be coupled to the inlet flange and to define a first inlet chamber; structuring a second inlet portion to be coupled to the first inlet portion and to define a second inlet chamber; structuring a first flow diverting element to be positioned between the inlet flange and the first inlet portion; structuring a second flow diverting element to be positioned between the first inlet portion and the second inlet portion; structuring the bore of the inlet flange to enable the sample gas to pass through the inlet flange and into the first inlet portion; structuring the first flow diverting element to divert a portion of the sample gas into the first inlet chamber and to conduct a remaining portion of the sample gas through the first inlet portion and into the second inlet portion; and structuring the second flow diverting element to divert a portion of the sample gas entering the second inlet portion into the second inlet chamber and to conduct a remaining portion of the sample gas through the second inlet portion as a molecular beam.

11. The method of claim 10, further comprising structuring at least one of the first flow diverting element and the second flow diverting element to include an exterior surface that is concave.

12. The method of claim 10, further comprising: structuring the first flow diverting element and the second flow diverting element to include a first end and a second end; and structuring the first end to include an apex defining an apex opening into an inner space that extends to a base opening at the second end.

13. The method of claim 12, further comprising structuring the first flow diverting element and the second flow diverting element to include a rim surrounding the base opening.

14. The method of claim 10, further comprising structuring the first inlet chamber to comprise an annular shape.

15. The method of claim 14, further comprising structuring the second inlet chamber to comprise an annular shape.

16. The method of claim 10, further comprising directing the molecular beam to an ion source.

17. The method of claim 10, further comprising structuring the first inlet chamber to connect to one or more pumping conduits that lead to a pumping device.

18. The method of claim 17, further comprising structuring the second inlet chamber to connect to one or more pumping conduits that lead to a pumping device.

19. A gas analyzing system comprising: a process chamber; a gas analyzer; andan inlet assembly positioned between the process chamber and the gas analyzer and structured to produce a laminar flow of a sample gas from the process chamber, the inlet assembly comprising, an inlet flange defining a bore that extends into the process chamber; a first inlet portion coupled to the inlet flange and defining a first inlet chamber; a second inlet portion coupled to the first inlet portion and defining a second inlet chamber; a first flow diverting element positioned between the inlet flange and the first inlet portion; and a second flow diverting element positioned between the first inlet portion and the second inlet portion, wherein the sample gas passes from the process chamber into the first inlet portion via the bore of the inlet flange, wherein the first flow diverting element diverts a portion of the sample gas into the first inlet chamber and conducts a remaining portion of the sample gas through the first inlet portion and into the second inlet portion, wherein the second flow diverting element diverts a portion of the sample gas entering the second inlet portion into the second inlet chamber and conducts a remaining portion of the sample gas through the second inlet portion as a molecular beam that is conducted to the gas analyzer.

20. The gas analyzing system of claim 19, wherein the gas analyzer includes an ion source.

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