Devices, systems, and techniques for ion beam mass analysis

Abstract

An apparatus may include an electrokinetic mass analysis (EDMA) assembly disposed downstream of a converging ion beam assembly. The EDMA assembly may include a first stage including: a first upper electrode disposed above the beam axis; and a first lower electrode disposed below the beam axis and opposed to the first upper electrode. The EDMA assembly may also include a second stage disposed downstream of the first stage and including: a second upper electrode disposed above the beam axis; and a second lower electrode disposed below the beam axis. The EDMA assembly may further include a deflection assembly disposed between the first stage and the second stage, the deflection assembly including: a barrier disposed along the bundle axis; an upper deflection electrode disposed on a first side of the barrier; and a lower deflection electrode disposed on the second side of the barrier.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to U.S. Patent Application Serial No. 18 / 131,271, filed April 5, 2023. The contents of the above application are incorporated herein by reference in their entirety. Technical Field

[0003] This disclosure relates to an ion beam apparatus, and more specifically, to an ion implanter capable of performing quality analysis. Background Technology

[0004] Ion implantation is a process that introduces dopants or impurities into a substrate by bombardment. An ion implantation system (“ion implanter”) may include an ion source and a substrate platform or processing chamber that houses the substrate to be implanted. The ion source may include a chamber for generating ions therein. A beam-wire ion implanter may include a series of beam-wire assemblies, such as a quality analyzer, a collimator, and various components for accelerating or decelerating the ion beam.

[0005] A useful function of an ion implanter beamline is to separate ions of different masses, so that the ion beam can be formed with the desired ions for treating the workpiece or substrate, while unwanted ions are intercepted in the beamline assembly and do not reach the substrate. In known systems, this mass analysis function is provided by an analytical magnet, which bends the beam of ions with all ions of the same energy into a curve to achieve the desired separation, the radius of which depends on the ion mass. However, such magnets are large, expensive, and bulky, and account for a significant portion of the cost and power consumption of the ion implanter.

[0006] To implant ions with relatively low energies (e.g., below approximately 50 keV), compact ion beam systems have been developed. These systems may include a plasma chamber that serves as an ion source and is positioned adjacent to a processing chamber housing the substrate to be implanted. An extraction grid or other extraction optics can be used to extract the ion beam from the plasma chamber to deliver it to the substrate in a desired beam shape (e.g., a ribbon beam). In these latter systems, mass analysis can be omitted due to size / space considerations and cost for mounting magnetic analyzers (as discussed above). Therefore, the use of such compact ion beam systems may be limited to applications where the purity of the implanted species is not critical.

[0007] Recently, a method for ion beam processing systems has been proposed, in which an electrodynamic mass analysis (EDMA) component is used to generate a mass-analyzed ion beam in an ion beam processing device that is more compact than known beamline ion implanters. This method uses a high-frequency field to filter out ions with unwanted masses. However, EDMA designs envisioned to date may not be able to produce acceptable high flux for ions with the target mass, especially when operating at high overall beam currents.

[0008] This disclosure is provided in view of these and other considerations. Summary of the Invention

[0009] In one embodiment, an apparatus is provided. The apparatus may include an electrodynamic mass analysis (EDMA) assembly disposed downstream of a converging ion beam assembly. The EDMA assembly may include a first stage, comprising: a first upper electrode disposed above the beam axis; and a first lower electrode disposed below the beam axis and opposite to the first upper electrode. The EDMA assembly may also include a second stage, disposed downstream of the first stage, comprising: a second upper electrode disposed above the beam axis; and a second lower electrode disposed below the beam axis. The EDMA assembly may further include a deflection assembly disposed between the first and second stages, the deflection assembly comprising: a blocking member disposed along the beam axis; an upper deflection electrode disposed on a first side of the blocking member; and a lower deflection electrode disposed on a second side of the blocking member.

[0010] In another embodiment, an ion beam processing system is provided, the ion beam processing system comprising: an ion source chamber for generating an ion beam as a continuous ion beam; a converging beam assembly for outputting the ion beam as a converging ion beam along a beam axis; and an electrodynamic mass analysis (EDMA) assembly. The EDMA assembly may include: a first stage for receiving the converging ion beam and applying a first RF signal between a first upper electrode and a first lower electrode; and a second stage disposed downstream of the first stage for applying a second RF signal between a second upper electrode and a second lower electrode. The EDMA assembly may also include a deflection assembly disposed between the first stage and the second stage and including a blocking member, an upper deflection electrode, and a lower deflection electrode, the blocking member being disposed along the beam axis, the upper deflection electrode being disposed on a first side of the blocking member, and the lower deflection electrode being disposed on a second side of the blocking member.

[0011] In another embodiment, a method may include guiding an ion beam as a continuous ion beam along a beam axis into a first stage of an electrically powered mass analysis (EDMA) assembly. The method may include using a first AC voltage signal applied at a first frequency to deflect the ion beam at the first stage of the EDMA assembly along a trajectory not parallel to the beam axis. The method may also include blocking a first portion of the ion beam along the beam axis at a stop downstream of the EDMA assembly, wherein a second portion of the ion beam passes through the stop as a clustered ion beam. The method may further include using a second AC voltage signal applied at the first frequency to deflect the clustered ion beam at a second stage downstream of the EDMA assembly, wherein a third portion of the beam exits the EDMA assembly. Attached Figure Description

[0012] Figure 1A This invention illustrates an ion beam processing system operating according to a first scenario, based on various embodiments of the present disclosure.

[0013] Figure 1B This disclosure shows another ion beam processing system according to other embodiments of the present disclosure.

[0014] Figure 1C Display as if passed Figure 1B Computer simulation of the ion beam representing B+ ions delivered by the ion beam processing system shown.

[0015] Figure 1D , Figure 1E , Figure 1F and Figure 1G Displayed Figure 1C Computer simulations of ion species transport for four different ions under the conditions shown.

[0016] Figure 2A A specific embodiment of a converging ion beam assembly is shown.

[0017] Figure 2B Another embodiment of the converging ion beam assembly is shown.

[0018] Figure 3A An EDMA assembly according to some embodiments of this disclosure is shown.

[0019] Figure 3B This shows a scenario of operating an EDMA assembly incorporating an electrostatic energy filter.

[0020] Figure 4 An exemplary simulated beam profile of an ion beam generated by an EDMA assembly arranged according to an embodiment of this disclosure is shown, illustrating the beam current as a function of time.

[0021] Figure 5A The energy dispersion of the boron ion beam in an EDMA assembly without the asymmetric deflection assembly is shown.

[0022] Figure 5B The energy dispersion of the boron ion beam in an EDMA assembly with an asymmetric deflection assembly according to an embodiment of this disclosure is shown.

[0023] Figures 6A-6C The operation of the EDMA assembly according to an embodiment of this disclosure is shown in one scenario.

[0024] Figure 6D-6F Show Figure 6A The diagram shows the operation of EDMA in the second scenario.

[0025] Figures 7A-7C Show Figure 6A The example shown illustrates an implementation of EDMA operation in the third scenario.

[0026] Figures 8A-8C Show Figure 6A The operation of the variant of EDMA shown is such that the length of the RF electrode in the first stage is different from the length of the RF electrode in the second stage.

[0027] Figures 9A-9C An embodiment is shown in which, apart from the length of the second level being adjusted, Figure 9A The parameters shown in the simulation are the same as those for Figure 6A The specified parameters.

[0028] Figure 10 The process flow according to the embodiments disclosed herein is presented.

[0029] Figure 11 Another process flow according to other embodiments of this disclosure is presented.

[0030] Figure 12 Another process flow is presented according to some embodiments of this disclosure.

[0031] The accompanying drawings are not necessarily drawn to scale. They are schematic diagrams only and are not intended to depict specific parameters of this disclosure. The drawings are intended to illustrate exemplary embodiments of this disclosure and should therefore not be considered as limiting the scope. In the drawings, similar numbers denote similar elements. Detailed Implementation

[0032] The apparatus, systems, and methods according to this disclosure will now be described more fully below with reference to the accompanying drawings, in which embodiments of the systems and methods are illustrated. The systems and methods may be implemented in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and that these embodiments will fully convey the scope of the systems and methods to those skilled in the art.

[0033] As used herein, elements or operations listed in the singular and preceded by the word "a (or an)" are understood to potentially include multiple elements or operations as well. Furthermore, references to "one embodiment" in this disclosure are not intended to exclude the existence of additional embodiments that also include the listed features.

[0034] This article provides a method for a mass-analytical ion implantation system using a novel EDMA device.

[0035] Figure 1A This disclosure shows an ion beam processing system 10 according to various embodiments. The ion beam processing system 10 includes: an ion source chamber 12 for generating an ion beam 14 as a continuous ion beam; an EDMA assembly 20 configured to receive the ion beam 14 and generate a mass-analyzed ion beam; and an electrostatic energy filter (shown as an electrostatic energy filter 60) arranged to generate an energy-filtered and mass-analyzed ion beam, which is guided to a substrate 70 and is shown as ion beam 14A. The structure and operation of electrostatic energy filters are well known, therefore details of the electrostatic energy filter 60 will be omitted herein. The basic operation of this energy filter employs a set of electrodes 62 disposed around the ion beam path, wherein the electrodes 62 apply a series of target direct current (DC) (static) voltages to deflect and accelerate and / or decelerate the ion beam. Thus, the electric field generated in the electrostatic energy filter 60 filters out ion species with unwanted energy (energy different from the target energy or target range) and high-energy neutral species. The general function of the EDMA assembly 20 is to filter out ions with unwanted mass (impurity ion species) and deliver target ion species with target mass to the energy filter 60.

[0036] According to various embodiments of this disclosure, the EDMA assembly 20 may include a first stage 30 for receiving an ion beam 14. The ion beam 14, when received, may have a trajectory along the beam axis (i.e., along the z-axis in the Cartesian coordinate system shown). The first stage 30 may apply a first RF signal between a first upper electrode 22 and a first lower electrode 24. In various non-limiting embodiments, a suitable frequency for the RF signal disclosed herein may be in the range of 200 kHz to 100 MHz.

[0037] As detailed in the following discussion, the first RF signal will deflect the ion beam 14 in a manner that facilitates quality filtering. The EDMA assembly 20 may also include a second stage 40 disposed downstream of the first stage 30 to apply a second RF signal between the second upper electrode 42 and the second lower electrode 44. In some embodiments, this second stage 40 may be arranged similarly to the first stage 30, while in other embodiments, the second stage 40 may differ from the first stage 30 in at least one embodiment.

[0038] In some embodiments, the electrodes of the first stage 30 and the second stage 40 extend along an electrode axis (represented by the x-axis), wherein the electrode axis extends perpendicular to the bundle axis. This configuration is particularly suitable for processing strip bundles characterized by having a long axis extending along the x-axis in cross-section. However, in other embodiments, the electrodes of the first stage 30 and the second stage 40 may be shaped to process dot bundles or pencil bundles having a more equiaxial shape in cross-section.

[0039] The EDMA assembly 20 may also include a deflection assembly 50, which is disposed between the first stage 30 and the second stage 40 and includes a stopper 56. Figure 1A As shown, according to some embodiments, the blocking member 56 may be disposed along the beam axis 57, which may represent the centerline located between the upper electrodes of the first stage 30 and the second stage 40 and the lower electrodes of the first stage 30 and the second stage 40. In some embodiments, the deflection assembly 50 may include: an upper deflection electrode 52 disposed on a first side of the blocking member 56; and a lower deflection electrode 54 disposed on a second side of the blocking member 56. Note that, for clarity of illustration, in Figure 1A Other walls that form part of the EDMA assembly 20 or similar EDMA device are omitted from the figures.

[0040] like Figure 1A As shown, in operation, the EDMA assembly 20 performs mass filtering on the ion beam 14 by deflecting the constituent ions of the ion beam 14 along different trajectories to intercept ions whose mass does not correspond to the target ion mass, while simultaneously delivering ions with the target mass to the energy filter 60. Figure 1A The image shows a computer simulation of an ion beam, representing three different ion species with different masses (in this case, B). + Ions, F + Ions and BF + (ion), wherein the target ion for implantation into the substrate 70 is B. + Ions. The incident ion beam (meaning the ion beam 14 preceding the EDMA assembly 20) may include portions of each of these ion species. Most F + Ions and BF + Ions are deflected as they pass through the EDMA assembly 20 in a manner that prevents them from being intercepted by components within the EDMA assembly 20, thus preventing them from being delivered to the energy filter 60. In the simulation shown, the input B is 3 mA, 20 kV. + The current is filtered, resulting in approximately 50% B at substrate 70. + The transmission of electric current. In other words, approximately 50% of B + ions to make B + The ions are deflected around the barrier 56 and exit the EDMA assembly 20 near the beam axis 57, without being intercepted by structures such as the exit tunnel 58. Meanwhile, as Figure 1A As shown, the ions of ion beam 14 can leave the EDMA assembly 20 in multiple bundles (rather than as a continuous ion beam) after encountering the blocking member 56.

[0041] Think back, in Figure 1AIn this embodiment, the ion beam 14 comprises individual ions traveling at a velocity determined by energy and mass, wherein the ions generally travel along the beam axis 57 during their entry into the first stage 30. During operation of the EDMA assembly 20, an AC (RF) voltage signal is applied in the first stage 30 to generate a time-dependent field that varies sinusoidally in the vertical direction (Y-axis) with a given maximum amplitude. The AC signal is applied such that, in any given case, the first upper electrode 22 is driven by a first voltage signal that is out of phase with the second voltage signal at the first lower electrode 24. According to some non-limiting embodiments, the phase shift between the first voltage signals may ideally be 180 degrees or close to 180 degrees, for example, 175 degrees, 178 degrees, or 179 degrees. This phase shift establishes a time-dependent electric field along the Y-axis. In other words, the equipotential field lines of this electric field will generally be positioned parallel to the xz plane in the Cartesian coordinate system shown. A similar scenario occurs at the second upper electrode 42 and the second lower electrode 44. As shown in various bundles of ion beams representing different arrival times corresponding to different phases of the AC signal, portions of ion beam 14 return to the original flight path and original angle oriented along beam axis 57 (independent of the phase (arrival time) of different ions), or are sufficiently close to beam axis 57 and sufficiently close to the original trajectory along the z-axis, thus exiting the EDMA assembly 20. (BF is indicated.) + Ions and F + Other portions of the ion beam 14 are deflected to positions and / or trajectories where such other portions are captured within the EDMA assembly 20.

[0042] Specifically, as the ion beam 14 passes through the first stage 30, the position and trajectory of the constituent ions of the ion beam 14 will fluctuate according to the magnitude and frequency of the applied AC (RF) signal. In the case of a sinusoidal RF signal, the ion beam 14 may exhibit a sinusoidal or wavy shape in the first stage. Different portions of the ion beam (characteristics of different species with different masses) will tend to propagate as waves with different amplitudes, some portions of which are blocked by the blocking element 56. Therefore, as shown, the ion beam 14 will tend to be arranged in a clustered form after passing through the blocking element 56. Furthermore, the EDMA assembly 20 can be configured to facilitate the propagation of the cluster associated with ion species of the target mass, as described in more detail below.

[0043] Advantageously, the first-stage power supply 32 can be arranged to apply a first RF voltage signal between the first upper electrode 22 and the first lower electrode 24, while the second-stage power supply 34 is arranged to apply a second RF voltage signal between the second upper electrode 42 and the second lower electrode 44. A controller 38 can also be provided to allow a first magnitude of the first RF voltage signal to change independently relative to a second magnitude of the second RF voltage signal. The controller 38 can also be arranged to allow a first phase of the first RF voltage signal to change relative to a second phase of the second RF voltage signal. This flexibility allows the properties of the ion beam processed by the EDMA assembly 20 to be customized according to the application, for example, to improve current yield, mass filtration, and / or energy dispersion of the delivered ions.

[0044] right Figure 1A One problem encountered when operating the system is that when a parallel ion beam with generally parallel ion trajectories is guided to the EDMA assembly 20, the space charge effect tends to reduce the EDMA assembly 20's ability to deliver ions of the target mass as the beam current increases. This is particularly problematic when the beam current is 15 mA and 20 kV at the input B to the EDMA assembly 20. + In a simulation of a current-carrying ion beam, it was observed that the resulting transported ion beam exhibited only 20% of the original beam current, and the Fo in the transported ion beam... + The ion transport rate is relatively high.

[0045] Transfer to Figure 1B , Figure 1B This illustration shows another ion beam processing system (shown as ion beam processing system 100) according to other embodiments of this disclosure. In this embodiment, in addition to including the electrostatic energy filter 60 and the EDMA assembly 20, Figure 1A In addition to the aforementioned components of the embodiments, the ion beam processing system 100 also includes a converging ion beam assembly 102. The converging ion beam assembly 102 is arranged to generate a converging ion beam received by the EDMA assembly 20. For Figure 1C The advantages of this configuration will be further explained.

[0046] In various embodiments, a deflection power supply 36 may be provided, wherein the deflection power supply 36 is arranged to apply a static bias voltage between the blocking element 56 of the deflection assembly 50 and the upper deflection electrode 52 and the lower deflection electrode 54. For example, the blocking element 56 may be set to ground potential or a negative potential, while both the upper deflection electrode 52 and the lower deflection electrode 54 may be set to a positive potential relative to ground, such as +1 kV, +1.5 kV, +2 kV, or any suitable potential depending on the mass and energy of the ion species guided through the EDMA assembly 20.

[0047] Transfer to Figure 1C , Figure 1C The display shows that the signal is delivered via ion beam processing system 100, as indicated by B. + Computer simulation of ion beams. In this simulation, a 18 mA 20 kV B... + The ion beam, as a converging ion beam 66, is guided from the converging ion beam assembly 102 into the EDMA assembly 20. Note that although the ion beam is referred to as "B..." + "Ion beam", but ion beam also includes BF + BF2 + and F + However, the simulation only shows the B of the ion beam. + Quantity.

[0048] A first RF voltage signal with a frequency of 4 MHz and a peak amplitude of 7.5 kV is applied between the first upper electrode 22 and the first lower electrode 24. Similarly, a second RF voltage signal with a frequency of 4 MHz and a peak amplitude of 7.5 kV is applied between the second upper electrode 42 and the second lower electrode 44. Note that in this embodiment, the phases of the first and second RF voltage signals are such that the potential at the first upper electrode 22 is always the same as the potential at the second upper electrode 42, and the potential at the first lower electrode 24 is always the same as the potential at the second lower electrode 44. Likewise, the phases of the first and second RF signals received at the first and second upper electrodes 22 and 42 are offset by 180 degrees relative to the phases of the first and second RF signals received at the first and second lower electrodes 24 and 44. A deflection voltage at a potential of +1.5 kV is applied to the upper deflection electrode 52 and the lower deflection electrode 54, while the blocking member 56 is grounded. The instantaneous electric field generated is shown as equipotential field lines 64.

[0049] Because the ion beam is guided as Figure 1C The converging ion beam 66 shown is thus designed to compensate for the space charge blow-up in the first stage 30 of the EDMA assembly 20, especially for higher beam currents (e.g., 18 mA in the example shown). Note that in many cases, the B generated from the ion source... + The bundle will include F + Species and BF +Heavier species, which will be present in greater quantities in the first stage 30, tend to produce the strongest space charge effect. These heavy / space charge-contributing species will tend to be largely filtered out by the deflection assembly 50 (including the blocking element 56). Furthermore, applying a bias voltage to the blocking element 56 relative to the upper deflection electrode 52 and the lower deflection electrode 54 allows for the filtering of desired space charge-driven ionic species (e.g., B in the first stage 30). + Adjustments are made to address excessive deflection. Therefore, with Figure 1A Compared to the previous embodiment, B + The percentage of beam delivery can be increased.

[0050] Transfer to Figure 1D , Figure 1E , Figure 1F and Figure 1G It is shown above Figure 1D In the case of boron ion beams and constituent species (corresponding to B respectively) + F + BF + and BF2 + Computer simulations of ion species transport. As qualitatively shown, a relatively large portion of B... + Ion current is delivered to substrate 70 (see Figure 1C (For clarity, reference numbers for individual components are omitted here.) Regarding F + Ion species, with the majority of the incident current transferred to the second stage 40 (see...) Figure 1C In ) . However, due to F + Compared to B + In terms of mass, it is heavier, and the field within EDMA makes F + The ion current is deflected in a manner that prevents it from entering the electrostatic energy filter 60. Regarding the heavier ion species (BF2) that primarily produce the space charge effect... + and most of my boyfriends + (Ions), most of which are filtered out at stage 30. For example, BF2 + The current is not actually deflected in the Y direction, so that the current is essentially completely blocked by the blocking element 56.

[0051] Regarding the converging ion beam assembly 102, in various embodiments, this assembly may be constructed according to any suitable known apparatus for generating a converging ion beam. Figure 2AA specific embodiment of a converging ion beam assembly 200 formed from a tetrode assembly is shown. The converging ion beam assembly 200 may include a first electrode 202, such as a plate of an ion source, to which a bias voltage is applied at the final beam energy. A negative bias voltage is applied to a suppression electrode 204 relative to the first electrode 202 to extract the ion beam. A positive bias voltage is applied to a defocusing electrode 206 relative to the suppression electrode 204 to slow the ion beam and increase its vertical size, and a grounding electrode 208 is provided at the beamline potential to generate a converging ion beam 260 entering the EDMA assembly 20.

[0052] Note that this configuration differs from known tetrode extraction assemblies, in which the defocusing electrode, similar to defocusing electrode 206, is kept negative relative to the beamline to keep the beamline neutralized. However, such neutralization is not necessary for the operation of the EDMA assembly 20.

[0053] In another embodiment, such as Figure 2B As shown, the converging ion beam assembly 250 can be configured as a single lens (with three sets of electrodes as shown), in which a bias voltage is applied to the intermediate electrode relative to the first and last electrodes to generate a converging ion beam 260.

[0054] Figure 3A An EDMA assembly 20A according to some embodiments of this disclosure is shown. In this example, the first stage 30 and the second stage 40 can be configured as previously described. A deflection assembly 50A is provided, wherein the center C of the blocking member 56A is disposed downstream of the upper deflection electrode 52A and the lower deflection electrode 54A. In this example, the upper deflection electrode 52A and the lower deflection electrode 54A can be configured as rods (extending in the x-direction) having an elliptical cross-section as shown. The blocking member 56A can also be configured as a rod (extending in the x-direction) having an elliptical cross-section as shown, wherein the center C of the ellipse is located downstream of the upper deflection electrode 52A and the lower deflection electrode 54A. Figure 3A The diagram also illustrates the electric field 302 present when there is a 0-volt potential difference between the first upper electrode 22 and the first lower electrode 24. The deflection of ions in this scenario can be termed asymmetric deflection because the position of the blocking element 56A relative to the upper deflection electrode 52A is asymmetrical with respect to the lower deflection electrode 54A. Specifically, an electrostatic field will exist even without an RF potential, because the heavy ion species are assumed to introduce a potential of approximately 1 kilovolt along the axis of symmetry A, referred to as the beam axis. Therefore, under a 0-volt instantaneous RF voltage applied between the first upper electrode 22 and the first lower electrode 24, a 1 kilovolt field exists in the middle between these electrodes, as shown in the figure. Compared to the case without space charge, this potential is B in the upward or downward direction. +Ions provide additional propulsion (kick).

[0055] Now turn to Figure 3B , Figure 3B This illustrates a scenario where an EDMA assembly incorporating an electrostatic energy filter 60 is operating, with an input voltage of 21 kV and a current of 18 mA. + The self-converging ion beam assembly is guided into the EDMA assembly 20. A first RF voltage signal with a maximum amplitude of 4 kV and a maximum amplitude of 4 MHz is applied between the first upper electrode 22 and the first lower electrode 24. Similarly, a first RF voltage signal with a maximum amplitude of 4 kV and a maximum amplitude of 4 MHz is applied between the second upper electrode 42 and the second lower electrode 44. A potential of +525 V is applied to the upper deflection electrode 52A and the lower deflection electrode 54A, while the blocking element 56A is kept at a potential of -525 V.

[0056] exist Figure 3B In this process, a voltage of 50A is applied to the deflection assembly to counteract the B-type charge generated by the space charge from heavy ions. + The additional "driving force" of the ions is compensated, especially in the first stage 30, such as Figure 3A This will be explained in detail below. Note that when using... Figure 1C In the configuration shown (where the blocking element 56 is located downstream of the upper deflection electrode 52 and the lower deflection electrode 54), this "symmetrical" over-deflection has been observed to compensate for the "driving force" from the space charge at the second stage 40. In contrast, in Figure 3B In the process, the asymmetric deflection of the converging ion beam 66 before it reaches the second stage 40 is mainly used to target the converging B. + The trajectory and position of the beam (ion beam 310) are corrected. Therefore, in addition to excellent quality filtration, it also provides... Figure 1C Compared to the configuration with a symmetrical deflection assembly, the EDMA assembly 20A provides a relatively high percentage of ion beam 310 delivery to the substrate 70.

[0057] Transfer to Figure 4 , Figure 4 An exemplary simulated beam profile of an ion beam generated by an EDMA assembly arranged according to an embodiment of this disclosure is shown, illustrating the beam current as a function of time. Figure 3B As shown, the beam current varies as a function of time, and its pulses reflect the deflection of a continuous ion beam deflected to different trajectories and positions. This current represents a current yield of more than 50% relative to the input beam current entering the EDMA assembly.

[0058] While EDMA configurations offer a compact and convenient way to achieve mass analysis, one problem encountered when using an EDMA assembly is that filtered ions with a given target mass undergo energy dispersion. Figure 5A The energy dispersion of the boron ion beam in an EDMA assembly without the asymmetric deflection assembly is shown, with the maximum to minimum energy dispersion being 6.5 kV.

[0059] Figure 5B The diagram illustrates the energy dispersion of the boron ion beam in an EDMA assembly with an asymmetric deflection assembly according to an embodiment of this disclosure, wherein the maximum to minimum energy dispersion is 3.4 kV. Figure 5A and Figure 5B The simulation is for an input ion beam of 21 kV (powered by an 18 mA B0). + 18mA BF + 18mA BF2 + and 8mA F + (Composition). This graph shows the energy distribution of the boron beam component after passing through the EDMA. Therefore, the disclosed embodiments are advantageous for achieving substantially small energy dispersion for the filtered ion beam.

[0060] As previously described, the following embodiments are contemplated, in which the amplitude of the first RF voltage signal applied to the first stage 30 is made to change independently relative to the second RF voltage signal applied to the second stage 40, such that the amplitude and / or phase of the first RF voltage signal is made to change relative to the amplitude and / or phase of the second RF voltage signal.

[0061] Figures 6A-6C The results of the operation of the EDMA assembly according to an embodiment of this disclosure in one scenario are shown. Figure 6D-6F Show Figure 6A The EDMA assembly 20A shown is operating in the second scenario. In this second scenario, the operation is the same as, except that the voltage at the RF electrode in the first stage 30 is set to a maximum amplitude different from the maximum amplitude of the voltage at the RF electrode in the second stage 40. Figure 6A The operation is shown below.

[0062] exist Figure 6A In the middle, the input B is 21 kiloelectron volts and 18 milliamperes. + The converging beam 602 is guided through the EDMA assembly 20A, where a 4 kV maximum amplitude RF voltage signal is provided to the first stage 30, and a similarly 4 kV maximum amplitude RF voltage signal is applied to the second stage 40. The two distinct RF voltage signals are positioned with a zero-degree phase shift between them. In this example, the length of the first stage 30 along the z-axis and the length of the second stage 40 along the z-axis are both 12.5 cm. The converging ion beam is equipped with an F... + Quantity and BF + Component B + Ion beams, such as Figure 6A As shown in the computer simulation. Figure 6B The current density as a function of ion energy is shown, revealing an energy dispersion of 3.5 kiloelectron volts. Figure 6C The current at the substrate as a function of time (the current is equivalent to 9 mA) is shown, resulting in a current yield of approximately 50%.

[0063] exist Figure 6D In the middle, 21 kiloelectron volts, the same 18 milliamperes input B + The converging beam 602 is guided through the EDMA assembly controller, where a 4 kV maximum amplitude RF voltage signal is provided to the first stage 30, and a 1 kV maximum amplitude RF voltage signal is applied to the second stage 40. A zero-degree phase shift is established between the two distinct RF voltage signals. A 600V DC deflection is provided in the deflection assembly. In this example, the lengths of the first stage 30 along the z-axis and the second stage 40 along the z-axis are both 12.5 cm. Figure 6E The current density as a function of ion energy is shown, revealing an energy dispersion of 3.0 kiloelectron volts. Figure 6F The current at the substrate as a function of time (the current is equivalent to 9 mA) is shown, resulting in a current yield of approximately 50%. Therefore, the reduction in the maximum voltage at stage 40 can produce a smaller energy dispersion in the filtered boron ion beam, at least for the specified case.

[0064] Also refer to Figures 6A-6C , Figures 7A-7C This illustration shows an embodiment in which the phase of the voltage signal applied to the RF electrode in the first stage 30 is set to a different phase than the phase of the voltage signal applied to the RF electrode in the second stage 40. Except that the phase of the RF voltage signal applied to the second stage 40 is offset by 60 degrees relative to the phase of the RF voltage signal applied to the first stage 30, Figure 7A The parameters shown in the simulation are the same as those for Figure 6A The specified parameters. Figure 7A Filtration (meaning quality selection) and Figure 6A The filter arrangement shown is not substantially different. However, the energy dispersion decreases from 3.5 keV to 2.5 keV, as... Figure 7B As shown, the throughput (throughput) Figure 7C The current increases to approximately 10 mA, which means the transmission percentage is approximately 56%.

[0065] Simultaneously refer to Figures 6A-6C . Figures 8A-8CAn embodiment is shown in which the length of the RF electrode in the first stage 30 differs from the length of the RF electrode in the second stage 40. The only difference is that the length of the second stage 40 is only 7.6 cm instead of the 12.5 cm length of the first stage 30. Figure 8A The parameters shown in the simulation are the same as those for Figure 6A The specified parameters. Figure 8A Filtration (meaning quality selection) and Figure 6A The filter arrangement shown is substantially the same. In this example, the energy dispersion increases slightly from 3.5 keV to 4 keV, as... Figure 8B As shown, the flux ( Figure 8C The current is increased to approximately 11 mA, which means a transmission percentage of approximately 62%, or an improvement of >20% relative to a configuration where the length of the first stage (30) and the length of the second stage (40) is 12.5 cm.

[0066] In summary, those skilled in the art will recognize that the EDMA configuration of the disclosed embodiments can be adjusted by combining physical changes to the electrodes at different stages with changes to the RF signals applied to different stages, in order to customize the parameters of the output ion beam.

[0067] Also refer to Figures 6A-6C . Figures 9A-9C An embodiment is shown in which, except that the length of the second stage 40 is only 7.6 cm, the maximum amplitude of the voltage applied to the second stage 40 is 1 kV, and the phase offset between the RF voltage signal at the first stage 30 and the RF voltage signal at the stage 40 is 60 degrees, Figure 9A The parameters shown in the simulation are the same as those for Figure 6A The specified parameters. In this example, the energy dispersion decreases slightly from 3.5 keV to 2.5 keV, as... Figure 9B As shown, the current ( Figure 9C Similarly, it is approximately 9 milliamperes.

[0068] Figure 10 A process flow 1000 according to an embodiment of this disclosure is presented. At block 1002, an ion beam is guided as a converging ion beam into an electrodynamic mass analysis (EDMA) assembly. At block 1004, a first RF voltage is applied to the first stage of the EDMA assembly as the ion beam is delivered through the EDMA assembly.

[0069] At block 1006, when the ion beam is delivered through the EDMA assembly, a DC voltage is applied between a set of deflection electrodes and a blocking element in the deflection assembly located downstream of the first stage.

[0070] At block 1008, when the ion beam is delivered through the EDMA assembly, a second RF voltage is applied to the second stage of the EDMA assembly located downstream of the deflection assembly.

[0071] Figure 11 An additional process flow 1100 according to other embodiments of this disclosure is presented. At block 1102, the ion beam is guided as a converging ion beam into the electrodynamic mass analysis (EDMA) assembly.

[0072] At block 1104, when the ion beam is delivered through the EDMA, a first RF voltage with a first maximum amplitude is applied to the first stage of the EDMA assembly.

[0073] At block 1106, when the ion beam is delivered through the EDMA assembly, a second RF voltage with a second maximum amplitude that is different from the first maximum amplitude is applied to the second stage of the EDMA assembly (where the second stage is downstream of the first stage).

[0074] Figure 12 Another process flow 1200 according to other embodiments of this disclosure is presented. At block 1202, an ion beam is guided as a converging ion beam into an electrodynamic mass analysis (EDMA) assembly. At block 1204, as the ion beam is delivered through the EDMA assembly, a first RF voltage having a first phase is applied to a first stage of the EDMA assembly.

[0075] At block 1206, when the ion beam is delivered through the EDMA assembly, a second RF voltage having a second phase different from the first phase is applied to the second stage of the EDMA assembly (where the second stage is downstream of the first stage).

[0076] In summary, the embodiments disclosed herein achieve at least the following advantages. The first advantage is achieved by providing a more compact mass analysis assembly for mass analysis of ion beams. The second advantage is cost savings when providing an EDMA-type system for mass analysis. The third advantage is the ability to maintain high-quality analysis in ion beams processed at relatively high beam currents (above several milliamps) within an EDMA system.

[0077] While certain embodiments of this disclosure have been described herein, this disclosure is not limited thereto, as its scope encompasses the broadest range permitted by the art and as can be indicated in this specification. Therefore, the above description should not be construed as restrictive. Those skilled in the art will contemplate other modifications within the scope and spirit of the appended claims.

Claims

1. An apparatus comprising: Electric Mass Analysis (EDMA) assembly, including: The first stage includes a first upper electrode and a first lower electrode. The first upper electrode is disposed above the beam axis, and the first lower electrode is disposed below the beam axis and opposite to the first upper electrode. The second stage, located downstream of the first stage, includes a second upper electrode and a second lower electrode, wherein the second upper electrode is positioned above the beam axis and the second lower electrode is positioned below the beam axis; and A deflection assembly is disposed between the first stage and the second stage. The deflection assembly includes a blocking member, an upper deflection electrode, and a lower deflection electrode. The blocking member is disposed along the beam axis. The upper deflection electrode is disposed on a first side of the blocking member, and the lower deflection electrode is disposed on a second side of the blocking member.

2. The apparatus of claim 1, wherein the center of the blocking member is disposed downstream of the upper deflection electrode and the lower deflection electrode.

3. The apparatus of claim 1, wherein the second upper electrode is shorter than the first upper electrode in a direction parallel to the beam axis, and wherein the second lower electrode is shorter than the first lower electrode in a direction parallel to the beam axis.

4. The apparatus of claim 1 further includes a first power supply and a second power supply, the first power supply being arranged to apply a first radio frequency voltage signal between the first upper electrode and the first lower electrode, and the second power supply being arranged to apply a second radio frequency voltage signal between the second upper electrode and the second lower electrode.

5. The apparatus of claim 1, further comprising a deflection power supply arranged to apply a static bias voltage between the blocking member and the upper deflection electrode and the lower deflection electrode.

6. The apparatus of claim 4, further comprising a controller, the controller being arranged to cause a first magnitude of the first radio frequency voltage signal to change independently relative to a second magnitude of the second radio frequency voltage signal, and being arranged to cause a first phase of the first radio frequency voltage signal to change relative to a second phase of the second radio frequency voltage signal.

7. An ion beam processing system, comprising: An ion source chamber is used to generate an ion beam as a continuous ion beam. A converging beam assembly for outputting the ion beam as a converging ion beam along the beam axis; as well as Electric Mass Analysis (EDMA) assembly, including: The first stage is used to receive the converging ion beam and apply a first radio frequency signal between the first upper electrode and the first lower electrode; The second stage, located downstream of the first stage, is used to apply a second radio frequency signal between the second upper electrode and the second lower electrode; and A deflection assembly is disposed between the first stage and the second stage and includes a blocking member, an upper deflection electrode and a lower deflection electrode. The blocking member is disposed along the beam axis, the upper deflection electrode is disposed on a first side of the blocking member, and the lower deflection electrode is disposed on a second side of the blocking member.

8. The ion beam processing system according to claim 7, wherein the center of the blocking member is disposed downstream of the upper deflection electrode and the lower deflection electrode.

9. The ion beam processing system of claim 7, wherein the second upper electrode is shorter than the first upper electrode in a direction parallel to the beam axis, and wherein the second lower electrode is shorter than the first lower electrode in a direction parallel to the beam axis.

10. The ion beam processing system of claim 7 further includes a first power supply and a second power supply, the first power supply being arranged to apply the first radio frequency signal between the first upper electrode and the first lower electrode, and the second power supply being arranged to apply the second radio frequency signal between the second upper electrode and the second lower electrode.

11. The ion beam processing system of claim 7 further includes a deflection power supply arranged to apply a static bias voltage between the blocking member and the deflection assembly.

12. The ion beam processing system of claim 10, further comprising a controller arranged to cause a first magnitude of the first radio frequency signal to change independently relative to a second magnitude of the second radio frequency signal, and further arranged to cause a first phase of the first radio frequency voltage signal to change relative to a second phase of the second radio frequency voltage signal.

13. The ion beam processing system of claim 7, wherein the converging beam assembly comprises a single lens.

14. The ion beam processing system of claim 7, wherein the converging beam assembly comprises a tetrode assembly, wherein a third lens of the tetrode assembly is positively biased.

15. The ion beam processing system of claim 7 further includes an electrostatic energy filter, the electrostatic energy filter being disposed downstream of the electric mass analysis assembly and including a plurality of electrodes to change the propagation direction of the ion beam.

16. A method comprising: The ion beam is guided as a continuous ion beam along the beam axis to the first stage of the Electro-Mechanical Mass Analysis (EDMA) assembly; The ion beam is deflected at the first stage of the electric mass analysis assembly along a trajectory not parallel to the beam axis by using a first AC voltage signal applied at a first frequency. The path of a first portion of the ion beam along the beam axis is blocked at a blocking member located downstream of the electric mass analysis assembly, wherein a second portion of the ion beam passes through the blocking member as a clustered ion beam. as well as The clustered ion beam is deflected at a second stage downstream of the electric mass analysis assembly by using a second AC voltage signal applied at the first frequency, wherein a third portion of the beam exits the electric mass analysis assembly.

17. The method of claim 16, further comprising applying a deflection voltage between the blocking member and a pair of deflection electrodes disposed on opposite sides of the beam axis.

18. The method of claim 16, wherein the first AC voltage signal includes a first voltage amplitude, and wherein the second AC voltage signal includes a second voltage amplitude smaller than the first voltage amplitude.

19. The method of claim 16, wherein the first AC voltage signal includes a first phase, and wherein the second AC voltage signal includes a second phase smaller than the first phase.

20. The method of claim 16, wherein the ion beam is provided to the first stage as a converging ion beam.

21. The method of claim 16, wherein the first AC voltage signal is applied between the first upper electrode and the first lower electrode, wherein the phase of the first AC voltage signal at the first upper electrode is offset by 180 degrees relative to the phase of the first AC voltage signal at the first lower electrode, wherein the second AC voltage signal is applied between the second upper electrode and the second lower electrode, and wherein the phase of the second AC voltage signal at the second upper electrode is offset by 180 degrees relative to the phase of the second AC voltage signal at the second lower electrode.

22. The method of claim 16, wherein a target ion species having a first mass exits the motorized mass analysis assembly, wherein an impurity ion species having a second mass different from the first mass does not exit the motorized mass analysis assembly along the beam axis, and wherein the ion beam exits the motorized mass analysis assembly as a mass-analyzed ion beam.

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