Multi-plasma ion source for in-line secondary ion mass spectrometry.

Abstract

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

Description

[Technical Field]

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

[0002] Secondary ion mass spectrometry (SIMS) is a metrology technique in which primary or incident ions are used to bombard the surface of a material being tested. As the incident ions bombard the material, secondary ions are ejected from the surface and captured by a secondary ion detector. The SIMS process enables the determination of deposited film parameters in semiconductor manufacturing, such as dopant levels and film impurities. However, the inventors have determined that the SIMS process is performed outside of the manufacturing flow, and the tested wafers or substrates are discarded after testing, as testing can introduce damaging particle contamination.

[0003] Therefore, the inventors have provided a method and apparatus for performing SIMS processing inline with the manufacturing flow using multiple ion sources, thereby improving yield and minimizing SIMS tool downtime. Summary of the Invention

[0004] A method and apparatus for performing in-line SIMS processing using a multiple ion source is provided herein.

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

[0006] In some embodiments, the method includes the steps of: the premixed gas mixture contains at least oxygen gas and at least one inert gas; the at least one inert gas is argon gas, helium gas, or xenon gas; the selection of the premixed gas mixture or the selection of the single species of ions is performed automatically; automatically selecting a gas or gas ratio for the premixed gas mixture based on a recipe executed by a controller of the in-line SIMS process; automatically selecting a single species of ions based on a recipe executed by a controller of the in-line SIMS process; The method may further include dynamically switching a single species of ions from the ion species selection to a second ion species selection different from the first ion species selection; the premixed gas mixture containing two gases having a gas ratio of 50:50 or 80:20; the premixed gas mixture being mixed in a gas manifold before injecting the premixed gas mixture into the plasma chamber; the in-line SIMS process being adjusted based on the gas ratio of the premixed gas mixture, the mass of the ions, or the intensity of the sputtering ions; and / or the gas ratio of the premixed gas mixture being selected based on providing a stabilized plasma to the plasma chamber.

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

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

[0009] In some embodiments, an apparatus for performing an in-line secondary ion mass spectrometry (SIMS) process may include: a premixed gas mixture source that stores a premixed gas mixture of two or more gases, the two or more gases containing 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 generate 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 sputtering ion species from the two or more ion species by adjusting a magnetic field; and a controller 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 vary the strength of the magnetic field to select a single species of ions formed from only one of the two or more gases in the premixed gas mixture.

[0010] Other and further embodiments are disclosed below.

[0011] Embodiments of the present principles, briefly summarized above and discussed in more detail below, can be understood by reference to exemplary embodiments of the present principles as illustrated in the accompanying drawings, which illustrate only typical embodiments of the present principles and are therefore not to be considered limiting in scope, since the present principles may also admit of other equally effective embodiments. [Brief explanation of the drawings]

[0012] [Figure 1] 1 shows a cross-sectional view of an in-line SIMS apparatus according to some embodiments of the present principles; [Figure 2] 1 shows a cross-sectional view of an in-line SIMS apparatus with gas and ion selection according to some embodiments of the present principles; [Figure 3]1 is a method for performing an in-line SIMS process according to some embodiments of the present principles. DETAILED DESCRIPTION OF THE INVENTION

[0013] To facilitate understanding, the same reference numerals have been used, where possible, to indicate identical elements common to the figures. The figures are not drawn to scale and may be simplified for clarity. Elements and features of one embodiment may be beneficially incorporated in other embodiments without further elaboration.

[0014] The method and apparatus provide a non-destructive, in-line SIMS (a stand-alone tool / process that is cleanroom compatible and can be used as part of a semiconductor manufacturing process) using multiple ion sources. In some embodiments, two or more ion species are generated using a mixed-gas plasma ion source for in-line metrology applications. Various gas mixture ratios are available for source stability and spatial resolution for SIMS applications. In some embodiments, the gas mixture is O2:Ne, O2:Ar, O2:Kr, and / or O2:Xe, among others. + The ion beam may include ions and inert gas ions. By introducing an inert gas into the ion source for in-line SIMS applications, the present principle has the advantage of being able to switch between different ion beam species without having to switch gases. Eliminating the need to switch gases increases productivity, improves metrology data quality, and reduces maintenance costs. The present principle allows for in-line measurement of various ion beam species on a single wafer without long delays due to the time required to switch gases and without instrument adjustments before metrology testing with different ion species.

[0015] SIMS is a powerful metrology technique widely used in the semiconductor industry for external (laboratory) destructive testing of substrates. A typical external SIMS instrument has two types of sputtering ion sources: an oxygen gas source, which is best for positive ion detection, and a cesium (Cs) source (e.g., a liquid Cs ampoule or a solid microbeam Cs source), which is best for negative ion detection. Oxygen and cesium are the probe ions for conventional external SIMS applications. The inventors have determined that oxygen and cesium ions are the most commonly selected sputter sources because they are the best and most economical sputter sources for positive and negative detection, respectively.

[0016] As in-line SIMS tools penetrate into semiconductor manufacturing processes, how to improve negative ion detection sensitivity has become a significant challenge. Cesium sources are used for negative ion detection in external laboratory SIMS tools and cannot be used in-line with manufacturing processes due to concerns about cesium metal contamination (e.g., metal particles may be formed during metrology testing, which could damage or reduce the performance of semiconductor structures formed on the substrate). In other words, the use of cesium metal is acceptable for external testing in a laboratory environment, where the substrate being tested is discarded. However, cesium metal cannot be used as an ion source for in-line SIMS processes, where the substrate remains throughout the manufacturing flow and is not discarded. Additionally, the inventors have confirmed that although oxygen can be used to measure negative ions, oxygen suppresses the production of negative ions, resulting in very low sensitivity for negative ions such as oxygen (O), fluorine (F), and chlorine (Cl).

[0017] The present inventors sought to overcome the aforementioned significant challenges to create an improved in-line SIMS process without the above-mentioned drawbacks. They found that inert gases (IGs) such as He, Ne, Ar, Kr, and Xe, unlike oxygen, do not suppress negative ion production. Therefore, using an IG beam improves negative ion detection sensitivity compared to an O beam. Additionally, IGs such as Ar are fully compatible with semiconductor manufacturing environments (e.g., no metal particle formation). The inventors conducted experiments with an Ar source, and the results showed that using an Ar source actually improves detection sensitivity for negative ions such as O, F, and Cl. However, they also found that gas switching for a SIMS system requires at least three days due to significant mechanical work (e.g., purging gas lines, regulatory requirements, etc.) and source stabilization, making it unsuitable for mass production.

[0018] As a result of experiments with both single element gases (such as O2 or Ar or Kr) and multi-element gas mixtures (such as O2 + Ar or O2 + Kr) in the source, the inventors have found that O2 + ions and Ar + (or Kr +We discovered that both ions (O2 and IG) are present in the source chamber plasma and can be selectively extracted as an ion beam. Therefore, an O2 or IG ion beam can be selected depending on the specific application. Using a gas mixture allows automatic switching between ion sources after initial setup by changing the magnetic field in the inline SIMS. A specific gas mixture can be achieved using either premixed gases or flow controllers and manifolds for the individual gas inlets. The specific gas mixture depends on the desired ion beam and source stability. In some embodiments, initial setup involves the following steps: The first task is to set an operating range of gas mixture and pressure for the plasma source to operate with long-term stability. The second task is to determine the correlation between the selected gas species as sputter ions and the primary beam mass filter, allowing only selected ions to enter the primary beam column. Finally, the third task is to adjust the gas mixture to maximize the current for the selected species. This is followed by the usual adjustments for the selected beam, and the conditions are stored for future use.

[0019] In some embodiments, all measurements begin automatically with the invocation of a recipe after an appropriate waiting time for the instrument to stabilize. Because the process can be performed automatically, no downtime is required. A potential drawback of using a mixed gas source may be that the ion beam intensity may be slightly reduced, depending in part on the variation in ionization efficiency due to the mixed gas relative to the gas mixture ratio. Once the source has stabilized after initial setup, switching between species is performed by choosing the appropriate magnetic field settings in the in-line SIMS with some fine tuning. For example, but not limited to, heavy oxygen ions (18O2 + ), light oxygen ions (16O2 + ), and argon ions (Ar +) can be obtained using a single source. The various ions generated in the plasma ion source are then extracted and focused and travel through a primary mass filter (flight tube). The application of an appropriate magnetic field allows selected species to travel through the flight tube while excluding all other ions. These ions are then directed through a primary ion column and refocused onto the sample surface as a sputter beam. The process is seamless because all adjustments for the various species are made at the initial setup. This principle provides the first use of gas mixtures for species selection and adjustment as a sputtering ion source for SIMS analysis.

[0020] In FIG. 1 , diagram 100 shows an in-line SIMS apparatus 102. As used herein, "in-line SIMS" refers to a SIMS apparatus or method capable of performing metrology sampling from a substrate without interfering with subsequent manufacturing of the substrate. In other words, the substrate is not damaged / contaminated or otherwise rendered unusable by the testing performed by the SIMS apparatus or process. In-line SIMS metrology testing is fully compatible with the substrate manufacturing flow and does not require the substrate to be discarded after testing. As discussed above, the inventors have found that cesium is not compatible with the substrate manufacturing flow due to metal particle contamination resulting from its use for SIMS testing. The in-line SIMS apparatus 102 of the present principles uses a gas mixture source 104 that 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, which do not pose a source of metal contamination during use in the in-line SIMS device 102.

[0021] The mixed gas source 104 directly supplies the mixed gas to the plasma chamber 106. A plasma is generated in the plasma chamber 106 to generate distinct ion species based on each of the gases that make up the mixed gas. The distinct ion species are then supplied to a sputtering and detection device 108. A magnetic field is used by the sputtering and detection device 108 to select only one of the distinct ion species for use as a sputtering species in a sputtering ion beam 110 that is directed to a specific location on a surface 114 of the substrate 112. In some embodiments, the substrate 112 may be disposed on a substrate support 116, which may be movable to allow for proper positioning beneath the sputtering ion beam 110. In a SIMS process, the sputtering ion beam 110 causes sputtering of the surface 114 of the substrate 112, emitting secondary ions 118 that are then detected by the sputtering and detection device 108.

[0022] An example of an in-line SIMS apparatus 102 that may be used in some embodiments is shown in diagram 200 of FIG. 2. In some embodiments, if one or more of the gas mixtures are to be mixed with one or more other elemental gases or with another gas mixture before being introduced into the plasma chamber 106, the gas mixture source 104 may include an optional manifold 220. In this non-limiting example, a first elemental gas source 222 is connected to the manifold 220 via a first elemental gas flow valve 228. A second elemental gas source 224 is connected to the manifold 220 via a second elemental gas flow valve 230. In some embodiments, the first elemental gas source 222 and the second elemental gas source 224 may be flowed into the manifold 220 and mixed according to a desired ratio (e.g., 50:50, 80:20, etc.) before entering the plasma chamber 106. In some embodiments, the third gas mixture source 226 may be flowed directly into the plasma chamber 106 and / or into the manifold 220 via a third gas mixture flow valve 232. In some embodiments, the manifold 220 is not used with the third gas mixture source 226 because the third gas mixture source 226 already contains two or more gases.

[0023] In some embodiments, a third gas mixture source 226 may be used in conjunction with the manifold 220 to facilitate mixing of the gas mixture with the first elemental gas source 222 and / or the second elemental gas source 224 before the gas mixture is flowed into the plasma chamber 106. While the third gas mixture source 226 is shown in FIG. 2 as containing a mixture of the first elemental gas source 222 and the second elemental gas source 224, in some embodiments, the third gas mixture source 226 may contain gases other than the first elemental gas source 222 and the second elemental gas source 224. In some embodiments, the in-line SIMS device 102 may include a gas mixture source 104 having only elemental gas sources or only a gas mixture source. For simplicity, this example is shown as having only two gas species, but any number of gas species may be used as the elemental gas source and / or the gas mixture source. In some embodiments, a gas mixture source flow valve 234 may be used to adjust the flow of the gas mixture from the gas mixture source 104 to the plasma chamber 106.

[0024] The gas mixture enters the plasma chamber 106, and separate ion species are formed from each of the gases in the gas mixture from the gas mixture source 104. A first ion species 236 and a second ion species 238 are formed from the gas mixture. In some embodiments, any number of ion species may be formed from each of the multiple gases forming the gas mixture. The first ion species 236 and the second ion species 238 are emitted from the plasma chamber 106 to a primary 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 of the ion species. A selected ion species, such as the first ion species 236, is then directed toward an entrance slit 242 and a focusing device 244. The selected ion species travels from the focusing device 244 as a sputtered ion beam 110 toward a location on the surface 114 of the substrate 112. The sputtered ion beam 110 sputters secondary ions 118 toward a secondary ion detector 246.

[0025] Because the in-line SIMS tool 102 operates within the manufacturing flow of the substrate 112, a controller 248 is in communication with various aspects of the in-line SIMS tool 102 and may also communicate with other controllers associated with the manufacturing of the substrate 112. As explained above, recipes may be used to enable automatic adjustments to the in-line SIMS tool 102 based on local information and / or previous substrate processing, etc. Recipes allow the controller 248 to be programmed for a specific application. In some embodiments, the controller 248 may vary the mixture gas flow rate to the plasma chamber 106 by controlling the mixture gas source flow valve 234, vary the mixture gas ratio by controlling the first individual gas flow valve 228, the second individual gas flow valve 230, and / or the third mixture gas flow valve 232, etc., control the pressure, temperature, and power of the plasma chamber 106, vary the magnetic field strength of the primary mass filter 240 to select which ion species will be present, and / or 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 sputtering ion beam 110 at a particular location on the surface 114 of the substrate 112. Because the plasma in the plasma chamber 106 has multiple ion species to choose from that are already in a stable plasma environment, switching between desired ion species is fast and efficient without requiring equipment downtime, outgassing, and stabilization.

[0026] The controller 248 controls the operation of the in-line SIMS apparatus 102 using direct control of the in-line SIMS apparatus 102 or, alternatively, by controlling a computer (or controller) associated with the in-line SIMS apparatus 102. During operation, the controller 248 enables data collection and feedback from the respective systems / apparatuses to optimize the performance of the in-line SIMS apparatus 102 and / or the manufacturing process of the substrate 112. The controller 248 generally includes a central processing unit (CPU) 250, memory 252, and support circuits 254. The CPU 250 may be any form of general-purpose computer processor usable in an industrial environment. The support circuits 254 are conventionally coupled to the CPU 250 and may include cache, clock circuits, input / output subsystems, power supplies, etc. Software routines, such as those described herein, may be stored in the memory 252 and, when executed by the CPU 250, may transform the CPU 250 into an application-specific computer (controller 248). The software routines may be stored and / or executed by a second controller (not shown) located remotely from the in-line SIMS device 102 .

[0027] Memory 252 is a form of computer-readable storage medium that stores instructions that, when executed by CPU 250, facilitate semiconductor process and equipment operation. The instructions in 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 for controlling in-line SIMS apparatus 102. The program code may conform to any one of a number of different programming languages. In one example, the present disclosure may be implemented as a program product stored on a computer-readable storage medium for use in a computer system. The program of the program product defines the functions of aspects (including the methods described herein). Exemplary computer-readable storage media include, but are not limited to, non-writable storage media on which information is permanently stored (e.g., a read-only memory device in a computer, such as a CD-ROM disk readable by a CD-ROM drive, a flash memory, a ROM chip, or any type of solid-state nonvolatile semiconductor memory), and writable storage media on which changeable information is stored (e.g., a floppy disk in a diskette drive or hard disk drive, or any type of solid-state random-access semiconductor memory). 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.

[0028] A method 300 for performing an in-line SIMS process using a mixed gas source is shown in FIG. 3. In block 302, a premixed mixture of two or more gases is injected into a plasma used in the in-line SIMS process. The two or more gases are compatible with downstream substrate fabrication processes and generate non-metallic ion species that allow further fabrication to be performed on the substrate after the in-line SIMS process is completed. The plasma decomposes the individual gases in the mixture into distinct ion species, with each individual gas usable as a primary sputtering ion in the in-line SIMS process. In some embodiments, the premixed gas mixture may be oxygen gas and one or more inert gases, such as, but not limited to, argon, helium, neon, krypton, and / or xenon. The ratio or ratios of gases in the premixed gas mixture (e.g., 50:50, 80:20, 70:20:10, etc.) may be adjusted to obtain a particular beam intensity of primary sputtering ions used to sputter secondary ions from the substrate surface during SIMS processing and / or to increase the sensitivity of the beam to particular materials of the substrate.

[0029] In some embodiments, the ratio or ratios of gases in the premixed gas mixture may be adjusted to increase the stability of the plasma in the plasma chamber. Plasma stability allows the plasma to continue producing test ions for a longer period of time, thereby increasing substrate yield (e.g., reducing downtime waiting for the plasma to stabilize). In some embodiments, for example, a controller may be used to automatically select the gas ratio or ratios based on beam intensity, plasma stability, and / or sensitivity to specific materials needed to obtain metrology information about the substrate material. In some embodiments, the controller may automatically select gases in the gas mixture based on a stored recipe. For example, the controller may automatically flow varying amounts of each gas into a gas manifold until the desired gas ratio is achieved. The premixed gas mixture is then flowed into the plasma chamber. The plasma in the plasma chamber generates ions specific to each gas species in the premixed gas mixture flowed into the plasma chamber.

[0030] In block 304, multiple ion species are emitted from the plasma into a magnetic field to select which of the multiple ion species will be the primary ion sputtering species used to test the surface of the substrate. In block 306, the strength of the magnetic field is varied to select a single species of ion based on the ion's mass. In some embodiments, the magnetic field may be adjusted to dynamically select the desired sputtering species (e.g., "on the fly" without having to shut down the in-line SIMS process). In block 308, the selected single species is directed toward the surface of the substrate as sputtering ions that sputter secondary ions from the surface of the substrate. In block 310, the secondary ions from the surface of the substrate are detected and used to determine various metrology data, such as dopant concentration, film material, etc. Using a premixed gas mixture in the plasma as an ion source for the in-line SIMS process allows for the selection of various ion sputtering species without downtime, gas evacuation, waiting for plasma stabilization, etc. Method 300 may be performed automatically through a recipe, or even other manufacturing flow processes, and / or by prior substrate processing data via a controller, etc.

[0031] In some embodiments of the present principles, an in-line SIMS process may be dynamically adjusted during a metrology session to vary the sputtering ion beam based on sensitivity to various materials. The ability to adjust parameters such as gas ratios, gas selection, ion species filtering, ion intensity selection / control, and / or ion selection based on material sensitivity, etc., has not previously been possible without the inventors' discoveries as found herein. The ability of an in-line SIMS process to be adjustable in real time without shutting down for reconfiguration will have a significant impact on increasing substrate yield and simultaneously increasing metrology data through use of the methods and apparatus disclosed herein.

[0032] Embodiments according to the present principles may be implemented in 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-transitory computer-readable medium.

[0033] While the forgoing 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 measurement process on a substrate, Forming sputtering ions using a mixture of two or more gases, wherein the mixture of the two or more gases forms nonmetallic sputtering ion species for both positive ion detection and negative ion detection. The nonmetallic sputtering ion species are released into the magnetic field, The strength of the magnetic field is changed to select a single ion formed from one of the two or more gases in the mixed gas for use in the secondary ion mass spectrometry process on the substrate. Methods that include...

2. The method according to claim 1, wherein the mixed gas contains at least oxygen gas and at least one inert gas.

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

4. The method according to claim 1, wherein the selection of the mixed gas or the selection of a single ion is performed automatically.

5. Automatically selects the gas or gas ratio for the mixed gas based on a recipe executed by the controller of the in-line secondary ion mass spectrometry (SIMS) process. The method according to claim 1, further comprising:

6. Automatically selecting the single ion based on a recipe executed by the controller of the in-line secondary ion mass spectrometry (SIMS) process. The method according to claim 1, further comprising:

7. The method involves simply changing the magnetic field to dynamically switch the single ion species from a first ion species selection target to a second ion species selection target that is different from the first ion species selection target. The method according to claim 1, further comprising:

8. The method according to claim 1, wherein the mixed gas contains two types of gases having a gas ratio of 50:50 or 80:

20.

9. The method according to claim 1, wherein the mixed gas is premixed in a gas manifold of a process chamber.

10. The method according to claim 1, wherein the method is adjusted based on the gas ratio of the mixed gas, the mass of the ions, or the intensity of the sputtering ions.

11. The method according to claim 1, wherein the gas ratio of the mixed gas is selected based on supplying a stabilized plasma into the plasma chamber.

12. A non-temporary computer-readable medium on which instructions are stored, wherein, when executed, the instructions cause a method to perform a measurement process on a substrate, and the method is Forming sputtering ions using a mixture of two or more gases, wherein the mixture of the two or more gases forms nonmetallic sputtering ion species for both positive ion detection and negative ion detection. The nonmetallic sputtering ion species are released into the magnetic field, The strength of the magnetic field is changed to select a single ion formed from one of the two or more gases in the mixed gas for use in the secondary ion mass spectrometry process on the substrate. Non-temporary computer-readable media, including [specific examples of such media].

13. The non-temporary computer-readable medium according to claim 12, wherein the mixed gas contains at least oxygen gas and at least one inert gas.

14. The non-temporary computer-readable medium according to claim 12, wherein the selection of the mixed gas or the selection of a single ion is performed automatically.

15. Automatically selecting the gas or gas ratio for the mixed gas based on a recipe executed by the controller of the in-line secondary ion mass spectrometry (SIMS) process, or Automatically select the single ion based on a recipe executed by the controller of the inline SIMS process. A non-temporary computer-readable medium according to claim 12, further comprising:

16. The non-temporary computer-readable medium according to claim 15, wherein the inline SIMS process is adjusted based on the gas ratio of the mixed gas, the mass of the ions, or the intensity of the sputtering ions.

17. The method involves simply changing the magnetic field to dynamically switch the single ion species from a first ion species selection target to a second ion species selection target that is different from the first ion species selection target. A non-temporary computer-readable medium according to claim 12, further comprising:

18. The non-temporary computer-readable medium according to claim 12, wherein the mixed gas is mixed in a gas manifold in front of the plasma chamber.

19. The non-transient computer-readable medium according to claim 12, wherein the gas ratio of the mixed gas is selected based on supplying a stabilized plasma into the plasma chamber.

20. An apparatus for performing a measurement process on a substrate, A plasma chamber configured to be supplied with a mixture of two or more gases, wherein the two or more gases contain nonmetallic ion species, and the plasma chamber is configured to generate two or more ion species from the two or more gases. A primary mass filter is fluidly connected to the plasma chamber and configured to select a sputtering ion species from the two or more ion species by adjusting the magnetic field. It is a controller, The mixed gas is supplied to the plasma chamber. Ions formed from the two or more gases are released from the plasma chamber into the magnetic field of the primary mass filter. By changing the strength of the magnetic field, a single type of ion formed from only one of the two or more gases in the mixed gas is selected. A controller configured to perform this task automatically A device equipped with the following features.

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