Multi-plasma ion source for on-line secondary ion mass spectrometry

Abstract

Methods are disclosed that utilize a premixed gas mixture to perform a metrology process on a substrate using an in-line secondary ion mass spectrometry (SIMS) process. A premixed gas mixture of two or more gases is injected into a plasma chamber configured to generate sputter ions for the online SIMS process. The two or more gases produce non-metallic ion species compatible with downstream substrate manufacturing processes and allow further manufacturing to be performed on the substrate after the online SIMS process has been completed. The sputter ions are ejected from a plasma chamber into a magnetic field. The intensity of the magnetic field is varied to select a single ion species. The single ion species are directed toward the surface of the substrate, and secondary ions sputtered from the surface of the substrate by the selected ion species are detected and analyzed.

Description

Technical Field

[0001] Embodiments of the present principles generally relate to semiconductor processing of semiconductor substrates. Background Art

[0002] Secondary ion mass spectrometry (SIMS) is a metrology technique that uses primary or incident ions to impact the surface of a material being tested. When the incident ions impact the material, secondary ions are expelled from the surface and captured by a secondary ion detector. The SIMS process allows the determination of deposited film parameters such as dopant levels and film impurities in semiconductor manufacturing. However, the inventors have observed that because the test may result in destructive particle contamination, the SIMS process is performed outside the manufacturing process and the tested wafers or substrates are discarded after the test is performed.

[0003] Thus, the present inventors have provided methods and apparatus for performing SIMS processing inline with a manufacturing process using multiple ion sources, improving throughput and minimizing SIMS equipment downtime. Summary of the invention

[0004] Methods and apparatus are provided herein for performing on-line SIMS processing using a multiple ion source.

[0005] In some embodiments, a method for performing a metrology process on a substrate using an online secondary ion mass spectrometry (SIMS) process may include: injecting a premixed gas mixture of two or more gases into a plasma chamber, the plasma chamber being configured to produce sputtered ions compatible with a downstream substrate manufacturing process for an online SIMS process, wherein the two or more gases produce non-metallic ion species; ejecting the sputtered ions from the plasma chamber into a magnetic field; varying the strength of the magnetic field to select a single ion species formed by only one of the two or more gases in the premixed gas mixture; directing the single ion species toward a surface of the substrate, and detecting secondary ions sputtered from the surface of the substrate by the single ion species.

[0006] In some embodiments, the method may further include: wherein the premixed gas mixture contains at least oxygen and at least one inert gas, wherein the at least one inert gas is argon, helium or xenon, wherein the selection of the premixed gas mixture or the selection of the single ion species is automatically performed, the gas or gas ratio of the premixed gas mixture is automatically selected based on a recipe executed by a controller of the online SIMS process, the single ion species is automatically selected based on a recipe executed by a controller of the online SIMS process, and the single ion species is dynamically switched from a first ion species selection to a second ion species selection different from the first ion species selection by only changing the magnetic field, wherein the premixed gas mixture contains two gases with a gas ratio of 50:50 or 80:20, wherein the premixed gas mixture is mixed in a gas manifold before injecting the premixed gas mixture into the plasma chamber, wherein the online SIMS process is adjusted based on the gas ratio of the premixed gas mixture, the mass of ions or the intensity of sputtered ions, and / or wherein the gas ratio of the premixed gas mixture is selected based on providing a stabilized plasma in the plasma chamber.

[0007] In some embodiments, a non-transitory computer-readable medium having instructions stored thereon, which when executed result in a method for performing a metrology process on a substrate using an online secondary ion mass spectrometry (SIMS) process being performed, the method may include the following steps: injecting a premixed gas mixture of two or more gases into a plasma chamber, the plasma chamber being configured to produce sputtered ions compatible with a downstream substrate manufacturing process for the online SIMS process, wherein the two or more gases produce non-metallic ion species, ejecting the sputtered ions from the plasma chamber into a magnetic field, varying the strength of the magnetic field to select a single ion species formed by only one of the two or more gases in the premixed gas mixture, directing the single ion species toward a surface of the substrate, and detecting secondary ions sputtered from the surface of the substrate by the single ion species.

[0008] In some embodiments, the method of non-transitory computer readable medium may further include: wherein the premixed gas mixture contains at least oxygen and at least one inert gas, wherein the selection of the premixed gas mixture or the selection of the single ion species is automatically performed, the gas or gas ratio of the premixed gas mixture is automatically selected based on a recipe executed by a controller of the online SIMS process, or the single ion species is automatically selected based on a recipe executed by a controller of the online SIMS process, and the single ion species is dynamically switched from a first ion species selection to a second ion species selection different from the first ion species selection by only changing the magnetic field, wherein the premixed gas mixture is mixed in a gas manifold before injecting the premixed gas mixture into the plasma chamber, wherein the online SIMS process is adjusted based on the gas ratio of the premixed gas mixture, the mass of ions or the intensity of sputtered ions, and / or wherein the gas ratio of the premixed gas mixture is selected based on providing a stabilized plasma in the plasma chamber.

[0009] In some embodiments, an apparatus for performing an online secondary ion mass spectrometry (SIMS) process may include: a premixed gas mixture source, the premixed gas mixture source containing a premixed gas mixture of two or more gases, wherein the two or more gases contain non-metallic ion species compatible with a downstream substrate manufacturing process; a plasma chamber, the plasma chamber fluidly connected to the premixed gas mixture source and configured to produce two or more ion species from the two or more gases from the premixed gas mixture source; a primary mass filter, the primary mass filter fluidly connected to the plasma chamber and configured to select a sputtering ion species from the two or more ion species by adjusting a magnetic field; and a controller, the controller being configured to automatically inject the premixed gas mixture from the premixed gas mixture source into the plasma chamber, eject ions formed from the two or more gases from the plasma chamber into the magnetic field of the primary mass filter, and change the strength of the magnetic field to select a single ion species formed from only one of the two or more gases of the premixed gas mixture.

[0010] Other and further embodiments are disclosed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] By referring to the illustrative embodiments of the present principles depicted in the accompanying drawings, the embodiments of the present principles briefly summarized above and discussed in more detail below can be understood. However, the drawings illustrate only typical embodiments of the present principles and are therefore not to be considered limiting of the scope, as the present principles may admit to other equally effective embodiments.

[0012] Figure 1 Depicted is a cross-sectional view of an in-line SIMS apparatus according to some embodiments of the present principles.

[0013] Figure 2 Depicted is a cross-sectional view of an in-line SMS apparatus with gas and ion selection, according to some embodiments of the present principles.

[0014] Figure 3 A method of performing an in-line SIMS process according to some embodiments of the present principles.

[0015] To facilitate understanding, the same reference numerals are used, where possible, to denote common elements in the drawings. The drawings are not drawn to scale and may be simplified for clarity. Elements and features of one embodiment may be beneficially incorporated into other embodiments without further description. DETAILED DESCRIPTION

[0016] The method and apparatus provide non-destructive in-line SIMS using multiple ion sources (a stand-alone tool / process that is compatible with cleanrooms and can be used as part of a semiconductor manufacturing process). In some embodiments, two or more ion species are generated using a mixed gas plasma ion source for in-line metrology applications. Various gas mixing ratios can be used to achieve source stability and spatial resolution for SIMS applications. In some embodiments, the gas mixture may include O2 + ions and inert gas ions such as, but not limited to, O2:Ne, O2:Ar, O2:Kr, and / or O2:Xe. By introducing an inert gas into the ion source for online SIMS applications, the present concept has the advantage of being able to switch ion beam species types without the need to switch gases. By removing the requirement to switch gases, productivity is increased, metrology data quality is improved, and maintenance costs are reduced. The present concept allows measurements of different ion beam species to be performed online on a single wafer without long delays due to the time required to switch gases and tool adjustments before performing metrology tests with different ion species.

[0017] SIMS is a powerful metrology technique that is widely used in the semiconductor industry for ex-situ (laboratory) destructive testing of substrates. A typical ex-situ SIMS tool has two types of sputtering ion sources: an oxygen source that is best suited for positive ion detection and a cesium (Cs) source (e.g., a liquid Cs ampoule or a solid microbeam Cs source) that is best suited for negative ion detection. Oxygen and cesium are the probe ions used for traditional ex-situ SIMS applications. The inventors have observed that oxygen and cesium are commonly chosen as sputtering sources because oxygen ions and cesium ions are the best and most economical sputtering sources for positive and negative detection, respectively.

[0018] As online SIMS tools enter semiconductor manufacturing processes, one of major challenges is how to improve the sensitivity of negative ion detection. Cesium sources are used for negative ion detection in ectopic laboratory SIMS tools, and can not be used online with manufacturing processes due to cesium metal contamination problems (metal particles may be formed during metrology tests, which will damage or reduce the performance of the semiconductor structure formed on the substrate, etc.). In other words, in ectopic tests in laboratory environments, it is acceptable to use cesium metal when the substrate being tested will be discarded. However, cesium metal cannot be used as the ion source of online SIMS processes, and substrates continue to pass through manufacturing processes and will not be discarded in the process. In addition, the inventor has observed that although oxygen can be used to measure negative ions, oxygen can suppress negative ion generation, and the sensitivity for negative ions such as oxygen (O), fluorine (F) and chlorine (Cl) is very poor.

[0019] The present inventors have attempted to overcome the above-mentioned significant challenges in order to produce an enhanced online SIMS process without the above-mentioned disadvantages. The present inventors have found that inert gases (IG) such as He, Ne, Ar, Kr and Xe do not suppress the generation of negative ions like oxygen. Therefore, the use of an IG beam will improve the negative ion detection sensitivity compared to an O2 beam. In addition, IG (such as Ar) is fully compatible with the semiconductor manufacturing environment (no metal particles will be formed, etc.). The present inventors performed experiments with an Ar source, and the results showed that the use of an Ar source does improve the detection sensitivity of negative ions such as O, F and Cl. However, the present inventors also found that switching the gas used for the SIMS equipment requires at least three days due to a large amount of mechanical work (e.g., gas line purging, standard requirements, etc.) and source stabilization, and therefore cannot be used in mass production.

[0020] As a result of experiments using both single element gas (O2 or Ar or Kr, etc.) and multi-element gas mixture (O2+Ar or O2+Kr, etc.) in the source, the inventors found that O2 + and Ar + (or Kr +) ions both exist in the source chamber plasma and can be selectively extracted as an ion beam. Therefore, the O2 or IG ion beam can be selected depending on the specific application. By using a gas mixture, after the initial setup, the ion source can be automatically switched from one ion source to another by changing the magnetic field in the online SIMS. A specific gas mixture can be obtained using a premixed gas or a flow controller and a manifold for individual gas inlets. The details of the gas mixture depend on the required ion beam and source stability. In some embodiments, the initial setup involves the following procedures. The first task is to establish the operating range of the gas mixture and pressure in which the plasma source operates with long-term stability. The second task is to determine the correlation between the selected gas species as sputtered ions and the main beam mass filter, where only selected ions are allowed to enter the main beam column. Finally, the third task is to adjust the gas mixture to maximize the gas flow (current) of the selected species. Then, the selected beam is tuned regularly, and the conditions are stored for future use.

[0021] In some embodiments, all measurements are automatically started with the recipe call after an appropriate wait time for the tool to be stabilized. Since the process can be done automatically, there is no downtime. A potential drawback to using a mixed gas source may be that the ion beam intensity may be slightly reduced, depending in part on the change in ionization efficiency of the gas mixture versus the gas mixture ratio. Once the source is stabilized after the initial setup, switching from one class to another can be accomplished by selecting the appropriate magnetic field settings and making some fine tuning in the online SIMS. For example, but not by way of limitation, a single source can be used to obtain heavy oxygen ions (18O2 + ), light oxygen ions (16O2 + ) and argon ions (Ar + ). The various ions produced in the plasma ion source are then extracted and focused, traveling through the primary mass filter (flight tube). An appropriate magnetic field is applied to allow the selected species to pass through the flight tube while repelling all other ions. The ions are then guided through the primary ion column and refocused on the sample surface as a sputtering beam. The process is seamless because all tuning of the various species is performed at the initial setup. The present principle provides for the first use of gas mixing for species selection and tuning of the sputtering ion source as a SIMS analysis.

[0022] exist Figure 1In view 100 of FIG. 1 , an online SIMS device 102 is depicted. As used herein, "online SIMS" refers to a SIMS device or method that can perform metrological sampling from a substrate without interfering with the subsequent manufacture of the substrate. In other words, the substrate is not damaged / contaminated or otherwise considered unusable due to the test performed by the SIMS device or process. The online SIMS metrology test is fully compatible with the manufacturing process of the substrate and does not require the substrate to be discarded after the test. As described above, the inventors have found that cesium is incompatible with the manufacturing process of the substrate due to metal particle contamination caused by the use of cesium for SIMS testing. The online SIMS device 102 of the present principle uses a gas mixture source 104, which excludes cesium and other metal-based gases from the gas mixture. In some embodiments, compatible gases may include, but are not limited to, oxygen and inert gases (such as, but not limited to, argon, helium, krypton, neon and / or xenon and the like), which do not provide a source of metal contamination during use with the online SIMS device 102.

[0023] The gas mixture source 104 provides the gas mixture directly into the plasma chamber 106. Plasma is generated in the plasma chamber 106 to produce different ion species based on each gas forming the gas mixture. The multiple different ion species are then provided to the sputtering and detection device 108. A magnetic field is used by the sputtering and detection device 108 to select only one ion species from the multiple different ion species to be used as a sputtering species in the sputtering ion beam 110 directed to a specific location on the surface 114 of the substrate 112. In some embodiments, the substrate 112 can be positioned on a substrate support 116, which can be movable to allow for proper positioning under the sputtering ion beam 110. In the SIMS process, the sputtering ion beam 110 causes sputtering of the surface 114 of the substrate 112, which ejects secondary ions 118, which are then detected by the sputtering and detection device 108.

[0024] Figure 2An example of an in-line SIMS apparatus 102 that may be used in some embodiments is depicted in view 200 of FIG. In some embodiments, when one or more of the gases in the gas mixture are to be mixed with one or more other single gases or with another gas mixture prior to introduction into the plasma chamber 106, the gas mixture source 104 may include an optional manifold 220. In an example that is not meant to be limiting, a first single gas source 222 is connected to the manifold 220 via a first single gas flow valve 228. A second single gas source 224 is connected to the manifold 220 via a second single gas flow valve 230. In some embodiments, the first single gas source 222 and the second single gas source 224 may flow into the manifold 220 and be mixed according to a desired ratio (e.g., 50:50, 80:20, etc.) prior to entering the plasma chamber 106. In some embodiments, a third mixed gas source 226 may flow directly into the plasma chamber 106 and / or flow into the manifold 220 via a third mixed gas flow valve 232. Since the third mixed gas source 226 already contains two or more gases, in some embodiments, the manifold 220 is not used in conjunction with the third mixed gas source 226 .

[0025] In some embodiments, the third mixed gas source 226 may be used with the manifold 220 to facilitate mixing with the first single gas source 222 and / or the second single gas source 224 before the gas mixture flows into the plasma chamber 106. Figure 2 106. In some embodiments, the third mixed gas source 226 may contain a gas in addition to the gases of the first single gas source 222 and the second single gas source 224. In some embodiments, the in-line SIMS apparatus 102 may contain a gas mixture source 104 having only a single gas source or only a mixed gas source and the like. For simplicity, the example is depicted with only two gas types, but any number of gas types may be used as single gas sources and / or mixed gas sources. In some embodiments, a gas mixture source flow valve 234 may be used to adjust the flow of the mixed gas from the gas mixture source 104 into the plasma chamber 106.

[0026] The mixed gas enters the plasma chamber 106 and different ion species are formed by various gases in the gas mixture from the gas mixture source 104. The first ion species 236 and the second ion species 238 are formed by the gas mixture. In some embodiments, any number of ion species can be formed by various gases in the multiple gases that form the gas mixture. The first ion species 236 and the second ion species 238 are ejected from the plasma chamber 106 into the main mass filter 240, which uses a magnetic field to separate the first ion species 236 from the second ion species 238 based on the mass of each ion species. The selected ion species (such as, for example, the first ion species 236) is then directed toward the entrance slit 242 and the focusing device 244. The selected ion species travels from the focusing device 244 toward a position on the surface 114 of the substrate 112 as a sputtered ion beam 110. The sputtered ion beam 110 sputters secondary ions 118 to the secondary ion detector 246.

[0027] Because the in-line SIMS apparatus 102 operates within the fabrication process of the substrate 112, the controller 248 communicates with various aspects of the in-line SIMS apparatus 102 and may also communicate with other controllers associated with fabricating the substrate 112. As described above, recipes may be used to allow automatic adjustment of the in-line SIMS based on local information and / or previous substrate processes and the like. Recipes allow the controller 248 to be programmed for a specific use. In some embodiments, the controller 248 may change the mixed gas flow rate into the plasma chamber 106 by controlling the gas mixture source flow valve 234; may change the mixed gas ratio by controlling the first single gas flow valve 228, the second single gas flow valve 230, and / or the third mixed gas flow valve 232 and the like; may control the pressure, temperature, and power of the plasma chamber 106; may select which selected ion species by changing the magnetic field strength of the primary mass filter 240; and / or may determine parameters based on a selected location and / or material of the substrate 112. In some embodiments, the controller 248 may also move the substrate support 116 to facilitate focusing the sputtered ion beam 110 at a specific location on the surface 114 of the substrate 112. Because the plasma in the plasma chamber 106 has a variety of ion species to choose from already in a stable plasma environment, switching between desired ion species is fast and efficient without requiring equipment downtime, gas pumpdown, and stabilization.

[0028] The controller 248 controls the operation of the online SIMS device 102 using direct control of the online SIMS device 102 or alternatively by controlling a computer (or controller) associated with the online SIMS device 102. In operation, the controller 248 enables data collection and feedback from the corresponding system / device to optimize the performance of the online SIMS device 102 and / or the manufacturing process of the substrate 112. The controller 248 generally includes a central processing unit (CPU) 250, a memory 252, and a support circuit 254. The CPU 250 can be any form of general-purpose computer processor that can be used in an industrial environment. The support circuit 254 is generally coupled to the CPU 250 and can include a cache, a clock circuit, an input / output subsystem, a power supply, and the like. A software program such as the method described herein can be stored in the memory 252 and, when executed by the CPU 250, converts the CPU 250 into a special-purpose computer (controller 248). The software program may also be stored and / or executed by a second controller (not shown) located remotely from the online SIMS device 102 .

[0029] The memory 252 is in the form of a computer-readable storage medium containing instructions that, when executed by the CPU 250, facilitate the operation of the semiconductor process and the device. The instructions in the memory 252 are in the form of a program product, such as a program and / or recipe that implements the method of the present principles to control the online SIMS device 102. The program code can conform to any of a variety of different programming languages. In one example, the present disclosure can be implemented as a program product stored on a computer-readable storage medium for use by a computer system. The program of the program product defines the functionality of various aspects, including the methods described herein. Illustrative computer-readable storage media include, but are not limited to, non-writable storage media (e.g., read-only storage devices within a computer, such as CD-ROM disks readable by a CD-ROM drive, flash memory, ROM chips, or any type of solid-state non-volatile semiconductor memory) on which information is permanently stored, and writable storage media (e.g., floppy disks in a diskette drive or hard disk drives or any type of solid-state random access semiconductor memory) on which variable information is stored. Such computer-readable storage media, when carrying computer-readable instructions that direct the functions of the methods described herein, are aspects of the present principles.

[0030] Figure 3300 for performing an online SIMS process with a mixed gas source is depicted in FIG. In block 302, a premixed gas mixture of two or more gases is injected into a plasma for an online SIMS process. The two or more gases produce non-metallic ion species that are compatible with downstream substrate manufacturing processes and allow further manufacturing to be performed on the substrate after the online SIMS process is completed. The plasma decomposes individual gases in the gas mixture into different ion species based on each individual gas in the individual gases that can be used as primary sputtering ions in the online SIMS process. In some embodiments, the premixed gas mixture can be oxygen and one or more inert gases, such as, but not limited to, argon, helium, neon, krypton, and / or xenon, and the like. One or more ratios of the gases in the premixed gas mixture (e.g., 50:50, 80:20, 70:20:10, etc.) can be adjusted to obtain a specific beam intensity of primary sputtering ions for sputtering secondary ions from a substrate surface during SIMS processing, and / or to increase the sensitivity of the beam to certain materials of the substrate.

[0031] In some embodiments, one or more ratios of gases in the premixed gas mixture can be adjusted to increase the stability of the plasma in the plasma chamber. The stability of the plasma allows the plasma to continue to produce ions for longer periods of testing, thereby increasing substrate yield (reducing downtime waiting for plasma stabilization, etc.). In some embodiments, for example, a controller can be used to automatically select one or more gas ratios based on beam intensity, plasma stability, and / or based on sensitivity to certain materials required for obtaining metering on substrate materials. In some embodiments, the controller can automatically select gases in the gas mixture based on stored recipes. For example, the controller can automatically cause various amounts of each gas to flow into the gas manifold until the desired gas ratio is obtained. The premixed gas mixture is then flowed into the plasma chamber. The plasma in the plasma chamber produces ions specific to each gas type of the premixed gas mixture that flows into the plasma chamber.

[0032] In block 304, multiple ion species are ejected from the plasma into the magnetic field to select which of these species will be the primary ion sputtering species for testing the substrate surface. In block 306, the strength of the magnetic field is changed to select a single ion species based on the mass of the ion. In some embodiments, the magnetic field can be adjusted to dynamically ("on the fly", without shutting down the online SIMS process, etc.) select the desired sputtering species. In block 308, the selected single species is directed toward the surface of the substrate as a sputtering ion, which causes secondary ions to be sputtered from the surface of the substrate. In block 310, the secondary ions from the substrate surface are detected and used to determine various metrology data, such as dopant concentration, film material, and the like. By using a premixed gas mixture in the plasma as an ion source for an online SIMS process, different ion sputtering species can be selected without downtime, gas evacuation, and waiting for plasma stabilization, etc. Method 300 can be automatically executed via a recipe, even through other manufacturing processes and / or through previous substrate processing data via a controller and the like.

[0033] In some embodiments of the present principles, an online SIMS process can be dynamically tuned during a metrology session to change the sputtering ion beam based on sensitivity to various materials. The ability to tune parameters such as gas ratios, gas selection, ion species filtering, ion intensity selection / control, and / or ion selection based on material sensitivity and the like has not previously been possible without the inventors' discoveries as described herein. The ability to instantly customize an online SIMS process without downtime for reconfiguration will have a significant impact on increasing substrate yields and at the same time increasing metrology data via the disclosed methods and apparatus using the present principles.

[0034] Embodiments according to the present principles may be implemented using hardware, firmware, software, or any combination thereof. Embodiments may also be implemented as instructions stored using one or more computer-readable media, which may be read and executed by one or more processors. A computer-readable medium may include any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computing platform or a "virtual machine" running on one or more computing platforms). For example, a computer-readable medium may include any suitable form of volatile or non-volatile memory. In some embodiments, a computer-readable medium may include a non-temporary computer-readable medium.

[0035] While the foregoing is directed to embodiments of the present principles, other and further embodiments of the present principles may be devised without departing from the basic scope thereof.

Claims

1. A method for performing a metrology process on a substrate using an online secondary ion mass spectrometry (SIMS) process, comprising the following steps: injecting a premixed gas mixture of two or more gases into a plasma chamber configured to generate sputtered ions compatible with a downstream substrate manufacturing process for the in-line SIMS process, wherein the two or more gases generate non-metallic ion species; ejecting sputtered ions from the plasma chamber into a magnetic field; varying the strength of the magnetic field to select a single ion species formed from only one of the two or more gases of the premixed gas mixture; directing the single ion species toward a surface of the substrate, and Secondary ions sputtered from the surface of the substrate by the single ion species are detected.

2. The method of claim 1, wherein the premixed gas mixture contains at least oxygen and at least one inert gas.

3. The method of claim 2, wherein the at least one inert gas is argon, helium or xenon.

4. The method of claim 1, wherein the selection of the premixed gas mixture or the selection of the single ion species is performed automatically.

5. The method of claim 1, further comprising the steps of: The gases or gas ratios of the premixed gas mixture are automatically selected based on a recipe executed by a controller of the in-line SIMS process.

6. The method of claim 1, further comprising the steps of: The single ion species is automatically selected based on a recipe executed by a controller of the in-line SIMS process.

7. The method of claim 1, further comprising the steps of: The single ion species is dynamically switched from a first ion species selection to a second ion species selection different from the first ion species selection simply by changing the magnetic field.

8. The method of claim 1, wherein the premixed gas mixture contains two gases in a gas ratio of 50:50 or 80:

20.

9. The method of claim 1, wherein the premixed gas mixture is mixed in a gas manifold prior to injecting the premixed gas mixture into the plasma chamber.

10. The method of claim 1, wherein the in-line SIMS process is adjusted based on a gas ratio of the premixed gas mixture, a quality of ions, or an intensity of sputtered ions.

11. The method of claim 1, wherein a gas ratio of the premixed gas mixture is selected based on providing a stabilized plasma in the plasma chamber.

12. A non-transitory computer readable medium having stored thereon instructions which, when executed, result in a method for performing a metrology process on a substrate using an in-line secondary ion mass spectrometry (SIMS) process being performed, the method comprising the steps of: injecting a premixed gas mixture of two or more gases into a plasma chamber configured to generate sputtered ions compatible with a downstream substrate manufacturing process for the in-line SIMS process, wherein the two or more gases generate non-metallic ion species; ejecting sputtered ions from the plasma chamber into a magnetic field; varying the strength of the magnetic field to select a single ion species formed from only one of the two or more gases of the premixed gas mixture; directing the single ion species toward a surface of the substrate, and Secondary ions sputtered from the surface of the substrate by the single ion species are detected.

13. The non-transitory computer readable medium of claim 12, wherein the premixed gas mixture contains at least oxygen and at least one inert gas.

14. The non-transitory computer readable medium of claim 12, wherein the selection of the premixed gas mixture or the selection of the single ion species is done automatically.

15. The non-transitory computer readable medium of claim 12, further comprising: automatically selecting a gas or gas ratio of the premixed gas mixture based on a recipe executed by a controller of the in-line SIMS process; or The single ion species is automatically selected based on a recipe executed by a controller of the in-line SIMS process.

16. The non-transitory computer readable medium of claim 12, further comprising: The single ion species is dynamically switched from a first ion species selection to a second ion species selection different from the first ion species selection simply by changing the magnetic field.

17. The non-transitory computer readable medium of claim 12, wherein the premixed gas mixture is mixed in a gas manifold prior to injecting the premixed gas mixture into the plasma chamber.

18. The non-transitory computer readable medium of claim 12, wherein the in-line SIMS process is adjusted based on a gas ratio of the premixed gas mixture, a quality of ions, or an intensity of sputtered ions.

19. The non-transitory computer readable medium of claim 12, wherein a gas ratio of the premixed gas mixture is selected based on providing a stabilized plasma in the plasma chamber.

20. An apparatus for performing an online secondary ion mass spectrometry (SIMS) process, comprising: a premixed gas mixture source containing a premixed gas mixture of two or more gases, wherein the two or more gases contain non-metallic ion species compatible with a downstream substrate manufacturing process; a plasma chamber fluidly connected to the premixed gas mixture source and configured to produce two or more ion species from the two or more gases from the premixed gas mixture source; a primary mass filter fluidly connected to the plasma chamber and configured to select a sputtered ion species from the two or more ion species by adjusting a magnetic field; as well as A controller, the controller being configured to automatically: injecting the premixed gas mixture from the premixed gas mixture source into the plasma chamber; ejecting ions formed from the two or more gases from the plasma chamber into the magnetic field of the primary mass filter; as well as The strength of the magnetic field is varied to select a single ion species formed from only one of the two or more gases in the premixed gas mixture.

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