Mixing devices, systems, and techniques for mass analysis of ion beams

Abstract

An apparatus includes an electrokinetic mass analysis (EDMA) assembly. The EDMA assembly may include: a first upper electrode disposed above the beam axis; and a first lower electrode disposed below the beam axis opposite the first upper electrode, the EDMA assembly being arranged to receive a first RF voltage signal at a first frequency. The apparatus may include a deflection assembly disposed downstream of the EDMA assembly, the deflection assembly including a barrier disposed along the bundle axis. The apparatus may include an energy dispersion reducer (ESR) disposed downstream of the deflection assembly, the energy dispersion reducer being arranged to receive a second RF voltage signal at a second frequency, the second frequency being twice the first frequency. The ESR may include: an upper ESR electrode disposed above a beam axis; and a lower ESR electrode disposed below the beam axis.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to U.S. Patent Application Serial No. 18 / 131,287, filed April 5, 2023. The contents of the above application are incorporated herein by reference in their entirety. Technical Field

[0003] This disclosure generally relates to ion beam apparatuses, and more specifically, to ion implanters capable of performing quality analysis. Background Technology

[0004] Ion implantation is a process in which dopants or impurities are introduced 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 in which ions are generated. 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] The 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 an ion beam processing system has been proposed in which an electrodynamic mass analysis (EDMA) assembly is used to produce a mass analyzed ion beam in a more compact ion beam processing apparatus. Such a method applies a high frequency field to filter out ions having unwanted masses. However, the EDMA designs conceived to date can not be able to produce an acceptable high flux of ions having a target mass, especially when operating at high overall beam currents. In addition, such EDMA designs can produce an unacceptably wide range of ion energies for the mass analyzed ion beam.

[0008] The present disclosure has been provided in view of these and other considerations. SUMMARY

[0009] In one embodiment, an apparatus is provided that includes an electrodynamic mass analysis (EDMA) assembly. The EDMA assembly can include a first upper electrode disposed above a beam axis and a first lower electrode disposed below the beam axis and opposite the first upper electrode, the EDMA assembly arranged to receive a first RF voltage signal at a first frequency. The apparatus can include a deflection assembly disposed downstream of the EDMA assembly, the deflection assembly including a stop disposed along the beam axis. The apparatus can include an energy spread reducer (ESR) disposed downstream of the deflection assembly, the ESR arranged to receive a second RF voltage signal at a second frequency, the second frequency being twice the first frequency. The ESR can include an upper ESR electrode disposed above the beam axis and a lower ESR electrode disposed below the beam axis.

[0010] In another embodiment, an ion beam processing system can include an ion source for producing an ion beam as a continuous ion beam and an electrodynamic mass analysis (EDMA) assembly disposed downstream of the ion source. The EDMA assembly can include a first upper electrode disposed above a beam axis and a first lower electrode disposed below the beam axis and opposite the first upper electrode, wherein the EDMA assembly is arranged to receive a first RF voltage signal at a first frequency. The ion beam processing system can include a deflection assembly disposed downstream of the EDMA assembly, the deflection assembly including a stop disposed along the beam axis and an energy spread reducer (ESR) disposed downstream of the deflection assembly. The ESR can be arranged to receive a second RF voltage signal at a second frequency, the second frequency being twice the first frequency, wherein the energy spread reducer includes an upper ESR electrode disposed above the beam axis and a lower ESR electrode disposed below the beam axis.

[0011] In another embodiment, a method may include guiding an ion beam as a continuous ion beam into an EDMA assembly, the EDMA assembly including a first upper electrode and a first lower electrode. The method may include applying a first RF voltage signal at a first frequency to the ion beam within the EDMA assembly as the ion beam is delivered through the EDMA assembly. The method may further include using a blocking member at a location downstream of the EDMA assembly to block a portion of the ion beam along its beam axis, thereby generating a mass-analyzed clustered ion beam. The method may also include applying an accelerating RF voltage signal to the mass-analyzed clustered ion beam as the clustered ion beam passes through an energy dispersion reducer, wherein the accelerating RF voltage signal is applied at a second frequency, the second frequency being twice the first frequency. Attached Figure Description

[0012] Figure 1A An exemplary system according to an embodiment of this disclosure is shown.

[0013] Figure 1B This illustrates another exemplary system according to an embodiment of the present disclosure.

[0014] Figure 1C This illustrates yet another exemplary system according to an embodiment of the present disclosure.

[0015] Figure 1D Additional exemplary systems are shown according to embodiments of this disclosure.

[0016] Figure 2A Showing other embodiments of the present disclosure according to the method for... Figure 1D The device shown is used to transport target ion species in one scenario.

[0017] Figure 2B Shown in Figure 2A An exemplary energy profile of the ion beam being processed in the apparatus shown.

[0018] Figure 2C Display devices without ESR and in Figure 2C An exemplary energy profile of the ion beam being processed in the apparatus shown.

[0019] Figures 3A-3C The operation of the apparatus according to an embodiment of the present disclosure is shown in one scenario.

[0020] Figure 4 An embodiment of the operation of another apparatus according to other embodiments of the present disclosure in another scenario is shown.

[0021] Figures 5A-5D The energy profile shown is used to tune the ion beam by voltage control of the RF voltage in the ESR in an apparatus arranged according to an embodiment of the present disclosure.

[0022] Figures 6A-6D An energy profile showing tuning of an ion beam using phase control of the RF voltage in an ESR is shown in an apparatus arranged according to embodiments of the disclosure.

[0023] Figure 7A One particular embodiment of a converging ion beam assembly is shown.

[0024] Figure 7B Another embodiment of a converging ion beam assembly is shown.

[0025] Figure 8 An exemplary process flow according to some embodiments of the disclosure is shown.

[0026] The drawings are not necessarily to scale. The drawings are merely schematic representations, not intended to portray specific parameters of the disclosure. The drawings are intended to depict only typical embodiments of the disclosure and therefore should not be considered to be limiting thereof. In the drawings: DETAILED DESCRIPTION

[0027] Reference will now be made to embodiments of the apparatus, systems and methods according to the present disclosure, which will be described in the following detailed description in reference to the drawings, in which embodiments of the systems and methods are shown. The systems and methods can be implemented in numerous 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 fully convey the scope of the systems and methods to those skilled in the art.

[0028] As used herein, an element or operation recited in the singular and preceded by the word "a" or "an" should be understood as potentially including plural elements or operations, unless otherwise indicated. Furthermore, references to "one embodiment" of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features.

[0029] Methods for mass analyzed ion implantation systems using a novel mass analysis device are provided herein. In various embodiments, the mass analysis device can be implemented in a beamline ion implanter or in a compact ion beam system.

[0030] Figure 1AAn ion beam processing system 100 according to various embodiments of the present disclosure is shown. The ion beam processing system 100 includes an ion source 12 for generating an ion beam 14 as a continuous ion beam, an EDMA assembly 20 arranged to receive the ion beam 14 and generate a mass analyzed ion beam, and an electrostatic energy filter (shown as energy filter 60) arranged to generate an energy filtered and mass analyzed ion beam (shown as ion beam 14AM) that is directed to a substrate 70. The structure and operation of electrostatic energy filters are well known, and thus details of the electrostatic energy filter 60 will be omitted herein. The basic operation of such an energy filter employs a set of electrodes 62 disposed about the ion beam path that apply a series of target direct current (DC) (static) voltages to deflect the ion beam and to accelerate and / or decelerate the ion beam. By this operation, the electric field generated in the electrostatic energy filter 60 will filter out ion species and high energy neutral species having an unwanted energy (that is different from a target energy or a target range of energies). The general function of the EDMA assembly 20 is to filter out ions having an unwanted mass and to transmit ions having a target mass into the energy filter 60.

[0031] According to various embodiments of the present disclosure, the EDMA assembly 20 can receive the ion beam 14 as a continuous ion beam. In some embodiments, the ion beam processing system 100 will also include a converging ion beam assembly 102, the operation of which is detailed below. The ion beam 14, when received, can have a trajectory along a beam axis (i.e., along the z-axis in the illustrated Cartesian coordinate system). In some embodiments, the beam axis can be located between the first upper electrode 22 and the first lower electrode 24, and in some embodiments can be located midway through the EDMA assembly, such as halfway between the first upper electrode 22 and the first lower electrode 24, as indicated by the dashed line. The EDMA assembly 20 can include an EDMA power supply 32 to apply a first radio frequency (RF) signal between the first upper electrode 22 and the first lower electrode 24. In particular, the RF signal between the first upper electrode 22 and the first lower electrode 24 can be delivered such that the phase of the RF signal at the upper electrode is 180 degrees out of phase with respect to the phase of the RF signal at the first lower electrode 24. Figure 1A

[0032] In various non-limiting embodiments, suitable frequencies for the RF signals of the present disclosure can range from 200 kilohertz to 100 megahertz. As detailed in the discussion below, the first RF signal will deflect the ion beam 14 in a manner that facilitates mass filtering.

[0033] ​The EDMA assembly 20 may further include a deflection assembly 50 disposed downstream of the EDMA assembly 20, wherein the deflection assembly 50 includes a stop member 56 disposed along the beam axis. In some embodiments, the deflection assembly 50 may include an upper deflection electrode 52 disposed on a first side of the stop member 56 and a lower deflection electrode 54 disposed on a second side of the stop member 56, and includes a deflection power supply 34 arranged to apply a static bias voltage between the stop member 56 on one side and the upper deflection electrode 52 and the lower deflection electrode 54 on the other side. Note that, for clarity, in Figure 1A Other walls that form part of the EDMA assembly 20 or similar EDMA device are omitted from the figures.

[0034] like Figure 1A As further shown, the ion beam processing system 100 may also include an energy spread reducer (ESR) 40 disposed downstream of the deflection assembly 50. The energy spread reducer (ESR) 40 may include an ESR power supply 36 arranged to deliver a second RF voltage signal at a second frequency to the electrodes of the ESR 40, the second frequency being twice the first frequency of the EDMA assembly 20. Figure 1A In one embodiment, the ESR 40 includes an upper ESR electrode 42A disposed above the beam axis and a lower ESR electrode 42B disposed below the beam axis. The upper ESR electrode 42A and the lower ESR electrode 42B will simultaneously receive a second RF signal with the same amplitude and phase.

[0035] In some embodiments, the electrodes of the EDMA assembly 20 and ESR 40 extend along an electrode axis (represented by the x-axis), wherein the electrode axis extends perpendicular to the bundle axis. This configuration may be particularly suitable for processing strip bundles, wherein the strip bundles are characterized by a long axis in a cross-section extending along the x-axis. However, in other embodiments, the electrodes of the EDMA assembly 20 and ESR 40 may be shaped to process dot bundles or pencil bundles with a more equiaxial cross-section.

[0036] 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 delivering ions with the target mass to the energy filter 60. The ions of the ion beam portion 14A then pass through the electrostatic energy filter 60 before impacting the substrate 70. As an example, the ion beam 14 can represent ions with a majority of B... + A boron ion beam, wherein the ion beam 14 may include other constituent ions (generally considered as impurity ions, such as F). + BF+ and BF 2+ ).

[0037] Specifically, when an RF field is generated between the first upper electrode 22 and the first lower electrode 24, the frequency of the RF voltage signal that generates the RF field can be selected based on the ion energy of the ion beam 14 and the mass of the constituent ions. By selecting an appropriate frequency and the maximum amplitude of the RF voltage, the ions to be filtered out can be deflected onto a trajectory intercepted by the surfaces of the various components within the EDMA assembly 20. For clarity, in Figure 1A The diagram only shows B. + The ion beam portion 14A and the representation of F + The ion beam portion 14B. However, depending on the type of ion source and the species supplied to ion source 12, other ion species may be present in the boron ion beam when entering the EDMA assembly 20. As shown, these portions can propagate through the EDMA assembly and due to B + With F + The different qualities result in different spatial distributions. By selecting the appropriate frequency and amplitude of the RF signal applied to the EDMA assembly 20, the ion beam portion 14A can be deflected in a manner that tends to guide a relatively large portion of the ion beam portion 14A through the EDMA assembly 20 and to the substrate 70, compared to the ion beam portion 14B.

[0038] Specifically, when ions pass through the area between the barrier 56 and the upper deflection electrode 52 or the lower deflection electrode 54, a DC voltage can be applied between the barrier 56 (this component may be grounded) and the upper and lower deflection electrodes 52 and 54. This DC voltage can be set to filter out ions with unwanted mass and provide the necessary deflection for desired ion species to reduce or eliminate the average vertical velocity of the ion bundle (e.g., bundle 14A-1) as it leaves the EDMA assembly.

[0039] like Figure 1A As further shown, in addition to mass filtering, by using a blocking member 56 to block the path of the ion beam 14 near or along the beam axis at a position downstream of the EDMA electrode, the ions in the ion beam 14 are bundled, so that the ion beam 14 leaves the EDMA assembly 20 as a mass-analyzed bundled ion beam. As an example, bundle 14A-1 may represent a B with a target mass for ion implantation. + Ions. Bundle 14B-1 can represent F + Ions. For example... Figure 1A As shown, although the F represented by ion beam section 14B + Ions entering the EDMA assembly may constitute a relatively large portion of the ions in ion beam 14, but compared with those representing B...+ The bunch 14B-1 constitutes a relatively small fraction of the ions that exit the EDMA compared to the bunch 14A-1.

[0040] In operation, as the ion beam 14 passes through the EDMA assembly 20, a certain amount of energy spread or energy dispersion will be imparted to the ion beam 14. Such energy spread can occur along the direction of beam propagation, e.g., generally along the z-axis, and energy spread can occur along the y-axis. For example, according to some non-limiting embodiments, a B + The ion beam can exhibit an energy spread of 3-6 keV after exiting the EDMA assembly 20.

[0041] According to embodiments of the present disclosure, the ESR 40 will reduce the energy spread of the ions in the ion beam 14 by applying an RF field at the electrodes of the ESR 40 to selectively accelerate or decelerate the ions in a given ion bunch, such as the bunch 14A-1. In particular, as the ions of the bunch 14A-1 enter the ESR 40, an RF voltage signal can be applied at twice the frequency of the RF voltage signal used in the EDMA 20. As noted above, the ions of the bunch 14A-1 can have a range of ion energies, e.g., between 17 and 23 keV for a nominal ion energy of 20 keV. The ion distribution within the bunch 14A-1 can be correlated to the ion energies of the ions such that slower ions tend to be located on the upstream side (left side in the figure), while faster (higher energy) ions are located on the downstream side (right side). As the RF voltage signal is applied between the upper ESR electrode 42A and the lower ESR electrode 42B, an oscillating electric field (not shown) at the RF frequency will be generated in the space through which the bunch 14A-1 passes. This electric field will tend to accelerate or decelerate the bunch 14A-1 during its transit through the ESR 40. Since slower ions will enter the ESR 40 at a different time than faster ions, the magnitude of the electric field acceleration / deceleration experienced by the leading ions (faster ions) in the ESR 40 will generally be different than the magnitude of the electric field acceleration / deceleration experienced by the trailing ions (slower ions). With appropriate timing, taking into account the energies of the ions of the entering bunch, such as the bunch 14A-1, and the phase of the RF signal applied to the EDMA assembly 20, the RF voltage signal can be delivered to the ESR 40 in a manner that tends to slow down the leading ions (faster ions) and speed up the trailing ions (slower ions). Thus, the ESR 40 can reduce the energy spread in the bunches of the ion beam 14.

[0042] Although the ion beam processing system 100 provides a compact method for generating a mass-analyzed ion beam with an acceptable energy distribution, the yield of ions with the target quality output to the substrate 70 may be relatively low for a given application. To properly operate the ESR 40, B in the ion beam 14... + The length of the cluster (e.g., cluster 14A-1) should ideally be equal to the quantity: (B + One RF cycle of the EDMA assembly (1 / 4 of the ion velocity) × 20. This requirement may reduce the "ideal" B + The transmission rate is limited to ~50%, which means that the amplitude of the current in the beam output from ESR 40 will be equal to 50% of the amplitude of the current input to EDMA assembly 20.

[0043] Returning to the converging ion beam assembly 102, this component helps control the space charge effect that tends to cause beam explosion, especially when the current density of the ion beam 14 is relatively high. The inventors have discovered that, for ion beams including BF... + and BF2 - The relatively high current B of the species + Computer simulations of ion beams, due to the presence of heavier species (e.g., BF), + and BF2 + The space charge effect of ions (including B) can generate a relatively significant beam potential at the center of the EDMA assembly 20. This potential tends to drive ions (including B) + Ions enter the uncompensated trajectory, causing B to... + Instead of bypassing the barrier 56 and leaving the EDMA assembly 20, the ions can be driven into the walls or other surfaces inside the EDMA assembly 20. By guiding the ion beam 14 as a converging ion beam, the space charge effect that tends to cause the ion beam 14 to explode can be compensated for, so that a larger proportion of the ions with the target mass (e.g., B) + The propagation process passes through the EDMA assembly 20, resulting in a higher yield.

[0044] Figure 7A A specific embodiment of a converging ion beam assembly 300 formed by a tetrode assembly is shown. The tetrode assembly may include a first electrode 302, such as a plate of an ion source, which is biased with the final beam energy. A negative bias is applied to a suppression electrode 304 relative to the first electrode 302 to extract the ion beam. A positive bias is applied to a defocusing electrode 306 relative to the suppression electrode 304 to slow down the ion beam and increase its vertical size, and a grounding electrode 308 is set with a beamline potential to generate a converging ion beam 310 entering the EDMA assembly 20.

[0045] It should be noted that this configuration differs from known quadrupole extraction assemblies in which a defocusing electrode similar to defocusing electrode 306 is held negative with respect to the beam line to maintain the beam line neutralized. However, such neutralization is not necessary for operation of the EDMA assembly 20.

[0046] In another embodiment, as shown in FIG. 3B, the converging ion beam assembly 350 can be configured as a single lens, as shown having three sets of electrodes, with the intermediate electrode biased with respect to the first and last electrodes to produce a converging ion beam 360. Figure 7B

[0047] Figure 1B An ion beam processing system 100B is shown arranged according to additional embodiments of the present disclosure. Ion beam processing system 100B can be considered a variation of ion beam processing system 100, with like elements labeled the same. Ion beam processing system 100B differs from ion beam processing system 100 in the configuration of the ESR. In this embodiment, the ESR 40B includes a set of DC electrodes coupled to be set at the beam line potential. As shown, these DC electrodes can include a first set: electrode 44A, electrode 44B disposed upstream of the upper ESR electrode 42A and lower ESR electrode 42B. As shown, these DC electrodes can also include a second set: electrode 46A, electrode 46B disposed downstream of the upper ESR electrode 42A and lower ESR electrode 42B. The advantage of the ESR 40B is to provide DC electrodes that tend to produce an electric field in the ESR 40B that extends more closely parallel to the z-axis in the direction of beam propagation and provide a more uniform field distribution in a direction perpendicular to the direction that the ion bunch travels along the z-axis. Such a more uniform z-axis field in the y-direction will tend to more properly reduce the energy spread of the ion bunch passing through the ESR 40B (see below Figure 2A ).

[0048] Figure 1C ​An ion beam processing system 100C arranged in accordance with an additional embodiment of the present disclosure is shown. Ion beam processing system 100C can be considered a variation of ion beam processing system 100, where like elements are labeled the same. Ion beam processing system 100C differs from ion beam processing system 100 in the configuration of the ESR. In this embodiment, ESR 40C includes an intermediate ESR electrode 42C disposed between upper ESR electrode 42A and lower ESR electrode 42B, where upper ESR electrode 42A, intermediate ESR electrode 42C, and lower ESR electrode 42B form a dual pass ESR. An advantage of ESR 40C is that the provision of intermediate ESR electrode 42C tends to produce an electric field that extends more closely parallel to the z-axis and provides a more uniform field in a direction perpendicular to the direction that the ion beam travels along the z-axis. Such a more uniform z-axis field in the y-direction will tend to more properly reduce the energy spread of the ion beam passing through ESR 40C (see below Figure 2A ).

[0049] Figure 1D An ion beam processing system 100D arranged in accordance with an additional embodiment of the present disclosure is shown. Ion beam processing system 100D can be considered a variation of ion beam processing system 100, where like elements are labeled the same. Ion beam processing system 100D differs from ion beam processing system 100 in the configuration of the ESR. In this embodiment, ESR 40D includes an intermediate ESR electrode 42C disposed between upper ESR electrode 42A and lower ESR electrode 42B, where upper ESR electrode 42A, intermediate ESR electrode 42C, and lower ESR electrode 42B form a dual pass ESR. ESR 40D can also include optional DC electrodes coupled to be set at beamline potentials. As shown, these DC electrodes can include a first set disposed upstream of upper ESR electrode 42A and lower ESR electrode 42B: electrode 44A, electrode 44B, and electrode 44C. As shown, these DC electrodes can also include a second set disposed downstream of upper ESR electrode 42A and lower ESR electrode 42B: electrode 46A, electrode 46B, and electrode 46C. An advantage of ESR 40D is that the provision of intermediate ESR electrode 42C tends to produce an electric field that extends more closely parallel to the z-axis and thus provides a more uniform field in a direction perpendicular to the direction that the ion beam travels along the z-axis. Such a more uniform z-axis field in the y-direction will tend to more properly reduce the energy spread of the ion beam passing through ESR 40D. In addition, the provision of DC electrodes (44A-44C and 46A-44C) further provides regions that tend to produce electric fields along the y-axis (see below Figure 2A ).

[0050] Turning to Figure 2AThis illustrates a computer simulation of the electric field and ion beam position in an ion beam processing system 100D under one operational scenario. In this example, an 18 mA boron beam is input with an energy of 21 kEV, and a 3 kV maximum amplitude RF voltage signal is applied at a first frequency to the first upper electrode 22 and the first lower electrode 24 of the EDMA assembly 20. See also... Figure 1B A 1500-volt DC deflection voltage is applied between the blocking member 56 on one side and the upper deflection electrode 52 and lower deflection electrode 54 on the other side. A dual-frequency RF voltage signal with a maximum amplitude of 500 volts is applied to the ESR 40A at twice the frequency of the first RF signal applied to the first upper electrode 22 and the first lower electrode 24. In addition, the dual-frequency RF voltage signal at the ESR 40A is offset by 300 degrees relative to the phase of the first RF voltage signal at the EDMA assembly 20.

[0051] like Figure 2A As shown, an electric field 120 is formed between the first upper electrode 22 and the first lower electrode 24, represented by a horizontal potential line. The electric field 120 oscillates at the RF frequency of the applied voltage signal, while generally applying a velocity component to the ion beam 110 in the y-direction, causing the ion beam 110 to exhibit a wavy characteristic. When the ion beam 110 interacts with the blocking element 56 of the deflection assembly 50, for any given period (360 degrees) of the RF electric field 120, the blocking element 56 will effectively generate two separate ion beams passing through the deflection assembly 50 and the ESR 40D.

[0052] The DC electric field 124 generated by the deflection assembly 50 is slightly more complex in shape and tends to deflect the positive ion beam (e.g., ion beam 110) inward toward the beam axis 112. The ESR 40D generates an energy spread reducing (ESR) electric field 130 at twice the frequency of the RF electric field 120. The field lines of the ESR 130 are generally shaped as a vertical field, i.e., along the y-axis, as shown. Since the two separate ion beams will pass through the ESR 40D in a single cycle of the RF electric field 120, the ESR 130 will oscillate through a cycle having half the duration of the RF electric field 120, similarly treating the two ion beams as they sequentially pass through the ESR 40D.

[0053] Therefore, after the ion beam 110 is deflected, focused, and accelerated by the ion beam processing system 100A, approximately 35% (6 mA) of B is achieved at the substrate. + Current yield, energy distribution, etc. Figure 2B As shown. Except for a small portion of F + Apart from that, all other species (e.g., BF) +BF2 + All of them were blocked and could not reach the substrate 70.

[0054] Transfer to Figure 2B This shows the connection to the above text. Figure 2A The illustrated scenario outlines the ion energy distribution function corresponding to the given conditions. The ion current distribution is characterized by the following peaks: these peaks have a full width at half maximum (FWHM) of 50 eV and a total energy dispersion of 400 eV.

[0055] It should be noted that the second "stage" of the EDMA assembly can be expected to be placed downstream of the deflection assembly 50 in place of the ESR device. This configuration in Figure 2C As shown in the figure, Figure 2C An ion beam processing system 200 is shown, with similar components labeled as identical to those in the preceding embodiments. In this embodiment, the ESR 40 is removed and replaced by a second set of RF electrodes (shown as a second upper electrode 242 and a second lower electrode 244). This embodiment serves as a two-stage EDMA assembly, where the first stage 230 can function similarly to EDMA assembly 20. The second stage 240 will apply an RF field similar to that of the first stage 230, resulting in the achievement of desired quality (e.g., F) reduction. + BF + and BF2 + Effective quality filtration, and in B + In this case, a current yield of up to 50% can be achieved. The problem with the ion beam processing system 200 is that, due to the lack of ESR 40 or ESR 40A, the energy dispersion of the analyzed ion beam may be too wide. This problem exists in... Figure 2C The curve shown is highlighted in the graph. Figure 2C The beam energy profile of a beam nominally 20 keV produced by the ion beam processing system 200 is shown, where the total energy is distributed at 2.5 keV.

[0056] Transfer to Figure 3A This illustrates another scenario of operation for the ion beam processing system 100A. In this example, an 18 mA boron beam is input with an energy of 21 kEV, and a 3.5 kV maximum amplitude RF voltage signal is applied at a first frequency to the first upper electrode 22 and the first lower electrode 24 of the EDMA assembly 20. See also... Figure 1B, a positive voltage of +400 volts is applied to the upper and lower deflection electrodes 52, 54, while a bias of -400 volts is applied to the blocker 56. A double frequency RF voltage signal with a maximum amplitude of 400 volts is applied to the ESR 40A at twice the frequency of the first RF signal applied to the first upper and lower electrodes 22, 24. Additionally, the double frequency RF voltage signal at the ESR 40A is offset by 300 degrees with respect to the phase of the first RF voltage signal at the EDMA assembly 20. In these cases, the output B + The current is 9 milliamps, which corresponds to a yield or transmission of about 50%. In Figure 3C In the case of FIG. 2, the current at the substrate is shown as a function of time, Figure 3C A series of regular peaks corresponding to the ion bunches separated in time according to the frequency of the RF voltage applied in the ion beam processing system 100A is presented. As shown in Figure 3B As shown in FIG. 3, the ion current distribution is characterized by the following peaks: the peaks have a full width at half maximum value of 40 electron volts and a total energy spread of 600 electron volts. Thus, modifying the voltage amplitude in the RF electrodes of the EDMA assembly 20 and the DC voltage at the deflection assembly 50 can improve the transmission of ions of the target species. As shown in Figure 3A In the case of FIG. 4, a portion of the F + The ions are not filtered and can hit the substrate 70.

[0057] Turning to Figure 4 , another scenario for operation of another ion beam processing system according to yet other embodiments of the disclosure is shown. As shown, the ion beam processing system 100B can include the same components as discussed earlier for the ion beam processing system 100A. Additionally, the ion beam processing system 100B includes a blocking aperture (shown as aperture assembly 48) disposed downstream of the ESR 40A. In this example, a beam of boron of 18 milliamps is input at an energy of 21 kiloelectron volts, a RF maximum amplitude voltage signal of 3.5 kilovolts is applied to the first upper and lower electrodes 22, 24 of the EDMA assembly 20 at a first frequency. Also referring to Figure 1B , a positive voltage of +400 volts is applied to the upper and lower deflection electrodes 52, 54, while a bias of -400 volts is applied to the blocker 56. A double frequency RF voltage signal with a maximum amplitude of 400 volts is applied to the ESR 40A at twice the frequency of the first RF signal applied to the first upper and lower electrodes 22, 24. Additionally, the double frequency RF voltage signal at the ESR 40A is offset by 300 degrees with respect to the phase of the first RF voltage signal at the EDMA assembly 20. Then the beam is decelerated to an energy of about 700 electron volts using the EPM 60. In these cases, the output B +The current is about 7 milliamps, which corresponds to a yield or transmission of about 40%. Thus, modifying the voltage amplitude in the RF electrodes of the EDMA assembly 20 and the DC voltage at the deflection assembly 50 can improve the transmission of ions of the target species and filter out undesired species. In such a configuration, all F + , BF + , BF2 + ions are filtered out.

[0058] As discussed previously with respect to Figure 2B , according to the present embodiments, an ESR such as ESR 40 or ESR 40A can be employed to reduce the energy spread of the ion beam output by the EDMA. According to yet other embodiments of the present disclosure, the operating parameters of the ion beam processing system including the EDMA and the ESR can be adjusted to tailor the ion beam energy profile depending on the target application. Figures 5A-5D A series of ion beam energy profiles are shown for boron ion beams produced by a variation of the ion beam processing apparatus in which the maximum amplitude of the RF voltage applied to the ESR is varied. For each ion beam energy profile, the phase difference between the RF voltage applied to the EDMA assembly and the accelerating RF voltage applied to the ESR is 330 degrees. Figure 5A corresponding to 400 volts, Figure 5B corresponding to 500 volts, Figure 5C corresponding to 600 volts, and Figure 5D corresponding to 700 volts. In all of these examples, the nominal energy of the boron ion beam entering the ESR is 21 keV. As Figure 5A shown in FIG. 6, at a setting of 400 volts, the ESR RF voltage effectively produces a very narrow energy distribution, as discussed previously. At 500 volts, the energy spread is wider, with a bimodal distribution showing two separate peaks that are 150 eV apart. At 600 volts, a clear bimodal energy distribution is shown, with two symmetric peaks that are approximately 300 eV apart. At 700 volts, the bimodal distribution is still present, with a peak separation of about 500 eV.

[0059] In summary, the RF voltage amplitude can be adjusted to tailor the energy distribution, thereby providing a range of ion implant profiles for the implanted ions. In other approaches, the tailoring of the beam energy profile can be used to simulate ion distributions for etch processes.

[0060] According to yet other embodiments of the present disclosure, Figures 6A-6DThe operating parameters of the ion beam processing apparatus exhibit a series of ion beam energy profiles for a boron ion beam resulting from variations of the ion beam processing apparatus, where the maximum amplitude of the RF voltage applied to the ESR is varied. For each profile, the RF voltage applied to the ESR is 700 volts, while the phase difference varies between 300 and 340 degrees. In each of the examples, there is a bimodal distribution of ion energies, with the peaks separated by approximately 500 electron volts. The difference is that as the phase offset increases, the beam current distribution systematically shifts from low energy to high energy as a function of ion energy.

[0061] Figure 8 A process flow 800 according to embodiments of the disclosure is shown. At step 802, an ion beam is directed as a converging ion beam into an electrodynamic mass analysis (EDMA) assembly.

[0062] At step 804, a first RF signal is applied to RF electrodes of the EDMA assembly at a first RF voltage and a first frequency. The RF electrodes of the EDMA assembly can include a first upper electrode and a first lower electrode configured to receive the RF signal, where the phase of the RF signal at the first upper electrode is offset 180 degrees relative to the phase of the RF signal at the first lower electrode. At step 806, a DC voltage is applied between a deflection electrode and a blocker of a deflection assembly located downstream of the RF electrodes. The DC voltage is applied while the ion beam is being transported through the EDMA assembly to deflect and intercept different ion species of the ion beam, where a mass analyzed cluster beam is produced. In particular, the blocker can intercept the ion beam in a manner that tends to produce a cluster ion beam, while the DC voltage in combination with the RF voltage applied at the RF electrodes will deflect ions having different masses differently, such that ions of a desired species and ions having a target mass are preferentially passed through the EDMA assembly.

[0063] At step 808, the clustered and mass analyzed ion beam is received in a dual channel ESR, where the dual channel ESR includes an upper ESR electrode and a lower ESR electrode and an intermediate ESR electrode.

[0064] At step 810, an acceleration RF voltage is applied to the dual channel ESR at a second frequency, which is twice the first frequency, where the energy spread of the mass analyzed cluster beam is reduced.

[0065] At step 812, the mass analyzed cluster beam is passed through an electrostatic energy filter before impinging on a substrate.

[0066] Compared to known beamline ion implanters, the present embodiments provide a first advantage of a reduced footprint for generating a mass analyzed ion beam using the EDMA assembly and the deflection assembly. A further advantage provided by the present embodiments is that the energy spread of the mass analyzed ion beam generated in the compact ion beam system can be reduced by means of the ESR assembly.

[0067] While certain embodiments of the present disclosure have been set forth in the foregoing, the disclosure is not limited thereto, as the scope of the disclosure is commensurate with the breadth of claims that can be presented. Therefore, the foregoing description should not be interpreted as limiting, but merely as exemplifications of the present disclosure. Those skilled in the art will envision other modifications apparent within the scope and spirit of the appended claims.

Claims

1. An apparatus comprising: Electric Mass Analysis (EDMA) assembly, including: 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, and the electric mass analysis assembly is arranged to receive a first radio frequency voltage signal at a first frequency. A deflection assembly, disposed downstream of the electric mass analyzer assembly, the deflection assembly including a blocking member disposed along the beam axis; and An energy dispersion reducer (ESR), disposed downstream of the deflection assembly, is arranged to receive a second radio frequency voltage signal at a second frequency, the second frequency being twice the first frequency, and the energy dispersion reducer includes: The upper energy dispersion reducer electrode is disposed above the beam axis; and The lower energy dispersion reducer electrode is located below the beam axis.

2. The apparatus according to claim 1, wherein the energy dispersion reducer further comprises an intermediate energy dispersion reducer electrode disposed between the upper energy dispersion reducer electrode and the lower energy dispersion reducer electrode, wherein the upper energy dispersion reducer electrode, the intermediate energy dispersion reducer electrode and the lower energy dispersion reducer electrode form a dual-channel energy dispersion reducer.

3. The device according to claim 1, wherein the deflection assembly further comprises 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.

4. The apparatus according to claim 1 further includes a converging ion beam assembly disposed upstream of the electric mass analysis assembly.

5. The apparatus of claim 4, wherein the converging ion beam assembly comprises a single lens.

6. The apparatus of claim 4, wherein the converging ion beam assembly comprises a tetrode assembly, wherein a third lens of the tetrode assembly is positively biased.

7. The apparatus of claim 1 further includes a blocking opening disposed downstream of the energy dispersion reducer.

8. An ion beam processing system, comprising: An ion source is used to generate an ion beam as a continuous ion beam. An electrodynamic mass analysis (EDMA) assembly, disposed downstream of the ion source, includes: 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, and the electric mass analysis assembly is arranged to receive a first radio frequency voltage signal at a first frequency. A deflection assembly, disposed downstream of the electric mass analyzer assembly, the deflection assembly including a blocking member disposed along the beam axis; and An energy dispersion reducer (ESR), disposed downstream of the deflection assembly, is arranged to receive a second radio frequency voltage signal at a second frequency, the second frequency being twice the first frequency, and the energy dispersion reducer includes: The upper energy dispersion reducer electrode is disposed above the beam axis; and The lower energy dispersion reducer electrode is located below the beam axis.

9. The ion beam processing system according to claim 8, further comprising: An electric mass analysis power supply is arranged to apply the first radio frequency voltage signal between the first upper electrode and the first lower electrode; A deflection power supply is arranged to apply a static bias voltage between the blocking member and the deflection assembly; as well as The power supply for the energy dissipation reducer is configured to apply the second radio frequency voltage signal.

10. The ion beam processing system according to claim 8, wherein the energy dispersion reducer further includes an intermediate energy dispersion reducer electrode disposed between the upper energy dispersion reducer electrode and the lower energy dispersion reducer electrode, wherein the upper energy dispersion reducer electrode, the intermediate energy dispersion reducer electrode and the lower energy dispersion reducer electrode form a dual-channel energy dispersion reducer.

11. The ion beam processing system of claim 8, further comprising a converging ion beam assembly disposed upstream of the electric mass analysis assembly.

12. The ion beam processing system of claim 11, wherein the converging ion beam assembly comprises a single lens.

13. The ion beam processing system of claim 11, wherein the converging ion beam assembly comprises a tetrode assembly, wherein a third lens of the tetrode assembly is positively biased.

14. The ion beam processing system of claim 8 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.

15. A method comprising: An ion beam is guided as a continuous ion beam into an electric mass analysis assembly, which includes a first upper electrode and a first lower electrode. When the ion beam is delivered through the electric mass analysis assembly, a first radio frequency voltage signal is applied to the ion beam at a first frequency in the electric mass analysis assembly. A blocking element is used at a location downstream of the electric mass analysis assembly to block the path of a portion of the ion beam along the beam axis, thereby generating a mass analysis bundled ion beam. as well as When the mass-analyzed clustered ion beam passes through the energy dispersion reducer, an accelerating radio frequency voltage signal is applied to the clustered ion beam, wherein the accelerating radio frequency voltage signal is applied at a second frequency, which is twice the first frequency.

16. The method of claim 15, further comprising: As the ion beam passes between the electric mass analysis assembly and the energy dispersion reducer, a DC deflection voltage is applied between the blocking element and a pair of deflection electrodes.

17. The method of claim 15, wherein the ion beam is provided to the electro-mass analyzer as a converging ion beam.

18. The method of claim 15, wherein the energy dispersion reducer comprises: The upper energy dispersion reducer electrode is positioned above the beam axis; as well as The lower energy dispersion reducer electrode is located below the beam axis.

19. The method of claim 18, wherein the energy dispersion reducer further comprises an intermediate energy dispersion reducer electrode disposed between the upper energy dispersion reducer electrode and the lower energy dispersion reducer electrode.

20. The method of claim 16, wherein the blocking element is at least partially disposed downstream of the pair of deflection electrodes.

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