Ion implanter

Abstract

This disclosure provides an ion implanter and a beam modulation device. The ion implanter may include: an ion source arranged to generate a continuous ion beam; a DC acceleration system for accelerating the continuous ion beam; and an AC linear accelerator for receiving the continuous ion beam and outputting a focused ion beam. The ion implanter may also include an energy dispersive electrode assembly that receives the focused ion beam and applies an RF voltage between a plurality of electrodes of the energy dispersive electrode assembly along the local propagation direction of the focused ion beam.

Description

Technical Field

[0001] The present disclosure relates generally to ion implantation apparatus, and more particularly to high energy beamline ion implanters. Prior Art

[0002] Currently, certain devices, such as insulated gate bipolar transistors (IGBTs), CMOS image sensors, and other semiconductor devices, are fabricated using multiple ion implantations. The use of multiple ion implantations facilitates the production of a smooth dopant profile with a target shape as a function of depth within the semiconductor substrate, a method particularly useful for relatively deep ion implantation profiles. In current practice, this target shape can be achieved by implanting ions at a relatively small dose at many different ion energies. For example, the current state of the art for CMOS image sensor (CIS) devices utilizes 20 discrete energies, ranging from 500 kiloelectronvolts (keV) to greater than 10 megaelectronvolts (MeV), with doses ranging from 1E10 / cm² to 1E12 / cm². For shorter wavelength sensing required for automotive and other applications, the number of implantation steps can be doubled or even increased.

[0003] Instead of using multiple implants to spread the ion energy within a given ion implantation run, it has been proposed to use sawtooth absorption filters. However, this approach carries risks of contamination, particles, and filter lifetime that may limit its use in a production environment.

[0004] It is with respect to these and other considerations that the present disclosure is provided. Summary of the Invention

[0005] In one embodiment, an ion implanter may include: an ion source configured to generate a continuous ion beam; a DC acceleration system configured to accelerate the continuous ion beam; and an AC linear accelerator configured to receive the continuous ion beam and output a focused ion beam. The ion implanter may also include an energy-dispersive electrode assembly configured to receive the focused ion beam and apply an RF voltage between a plurality of electrodes of the energy-dispersive electrode assembly along a local propagation direction of the focused ion beam.

[0006] In another embodiment, an ion implanter is provided, comprising: an ion source that generates an ion beam as a continuous ion beam; and a linear accelerator that focuses the continuous ion beam and outputs the ion beam as a clustered ion beam. The ion implanter may include a scanner configured to receive the clustered ion beam propagating along a first direction and scan the clustered ion beam along a second direction perpendicular to the first direction. The ion implanter may further include a collimator positioned downstream of the scanner that receives the clustered ion beam and outputs the clustered ion beam as a ribbon beam. The ion implanter may also include an energy-dispersive electrode assembly positioned downstream of the linear accelerator and configured to apply an AC voltage between a plurality of electrodes of the energy-dispersive electrode assembly along a local propagation direction of the ribbon beam.

[0007] In additional embodiments, the beam conditioning device may include a scanner arranged to receive a focused ion beam propagating along a first direction and scan the ion beam along a second direction perpendicular to the first direction. The beam conditioning device may also include a collimator positioned downstream of the scanner, receiving the focused ion beam, and outputting the focused ion beam as a ribbon beam. The beam conditioning device may further include an energy dispersive electrode assembly positioned downstream of the linear accelerator and arranged to apply an AC voltage between a plurality of electrodes of the energy dispersive electrode assembly along a local propagation direction of the ribbon beam. The beam conditioning device may additionally include a controller arranged to control the scanner and the energy dispersive electrode assembly to produce a uniform energy dispersion of the ribbon beam across the width of the ribbon beam in a direction perpendicular to the local propagation direction of the ribbon beam. Simple diagram description

[0008] FIG. 1 depicts an ion implanter according to an embodiment of the present disclosure. FIG. 2 illustrates another exemplary ion implanter according to an embodiment of the present disclosure. FIG3 depicts an ion implanter arranged in accordance with other embodiments of the present disclosure. FIG4 depicts an ion implanter arranged in accordance with other embodiments of the present disclosure. The drawings are not necessarily to scale. The drawings are merely representations and are not intended to depict specific parameters of the present disclosure. The drawings are intended to depict exemplary embodiments of the present disclosure and, therefore, should not be considered limiting in scope. In the drawings, like numbers represent like elements. Implementation Method

[0009] The devices, systems, and methods according to the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings, which illustrate embodiments of the systems and methods. The systems and methods may be embodied 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 will fully convey the scope of the systems and methods to those skilled in the art.

[0010] Terms such as "top," "bottom," "upper," "lower," "vertical," "horizontal," "lateral," and "longitudinal" may be used herein to describe the relative placement and orientation of components and their components, relative to the geometry and orientation of the components of a semiconductor manufacturing device as presented in the drawings. The terminology may include the words specifically mentioned, derivatives thereof, and words of similar import.

[0011] As used herein, elements or operations listed in the singular and performed with the word "a" or "an" are understood to potentially include plural elements or operations. In addition, reference to "one embodiment" of the present disclosure is not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features.

[0012] Methods are provided herein for improved ion implantation systems and components based on beamline architectures, and in particular for high-energy ion implanters, such as linear accelerator-based ion implanters. For brevity, ion implantation systems may also be referred to herein as "ion implanters." Various embodiments require novel methods for generating a focused ribbon ion beam for processing in a linear accelerator or LINAC.

[0013] In various embodiments, an electrode assembly is provided downstream of the LINAC to modify the energy of the focused ion beam using an AC signal transmitted to the electrode assembly at a high frequency. In various embodiments in which the substrate and / or the ion beam is scanned to process the substrate, the frequency of the energy variation can be set much faster than the substrate scan, so that the energy variation produced by the electrode assembly appears as a controlled, repeatable energy spread at every point on the substrate.

[0014] FIG1 depicts an ion implanter 100 according to an embodiment of the present disclosure. The ion implanter 100 includes an ion source 102 arranged to generate a continuous ion beam, depicted as ion beam 120. The ion implanter 100 may include an AC linear accelerator, depicted as linear accelerator 104, positioned downstream of the ion source 102 and receiving the ion beam 120. The linear accelerator 104 may include a buncher (not separately depicted), as is known in the art, to modify the ion beam 120 so as to generate a clustered ion beam 122. At various stages of the linear accelerator 104, the energy of the clustered ion beam 122 may be increased to a target ion energy, such as 1 MeV, 2 MeV, 5 MeV, or other suitable ion energy, according to various non-limiting embodiments.

[0015] According to some non-limiting embodiments of the present disclosure, the ion implanter 100 may include additional components positioned downstream of the linear accelerator 104 to shape, collimate, filter, or scan the focused ion beam 122, or to perform any combination of these operations. These additional components are illustrated by downstream components 106, which are positioned intermediate between the linear accelerator 104 and the energy-dispersive electrode assembly 108. The energy-dispersive electrode assembly 108 is arranged to receive the focused ion beam 122 and adjust the energy of the focused ion beam 122 to output an energy-dispersive ion beam 124 to the substrate 110.

[0016] In various embodiments, the energy of the focused ion beam 122 can be adjusted by applying a high-frequency voltage to the energy-dispersive electrode assembly 108. This voltage generates a corresponding high-frequency electric field along the propagation direction of the focused ion beam 122, represented as the Z-axis in the illustrated Cartesian coordinate system. Specifically, in this and other embodiments, the energy-dispersive electrode assembly 108 can be configured as a hollow electrode that conducts the focused ion beam 122 while applying the high-frequency field along the propagation direction. In this manner, variable energy can be imparted to the focused ion beam 122 during its passage through the energy-dispersive electrode assembly. For example, the RF power supply 130 can be used to generate an AC voltage signal at a suitable frequency (e.g., greater than 1 MHz) between different electrodes within the energy-dispersive electrode assembly 108 (as used herein, the terms "AC voltage" or "AC voltage signal" can encompass any suitable frequency range, including 1 kHz, 1 MHz, etc.). Examples of suitable acceleration frequencies for driving the acceleration stage of the linear accelerator and energy dispersive electrode assembly 108 include frequencies between 13.56 megahertz and 40 megahertz in various non-limiting embodiments.

[0017] According to various embodiments of the present disclosure, the AC voltage delivered to the energy-dispersive electrode assembly 108 can have a suitable amplitude to produce a target energy dispersion within the energy-dispersive ion beam 124 delivered to the substrate 110. For example, according to some non-limiting embodiments, the energy-dispersive ion beam 124 can have an energy distribution with a full width at half maximum (FWHM) corresponding to 1% of the nominal ion beam energy, 2% of the nominal energy, 5% of the nominal energy, 10% of the nominal energy, or 20% of the nominal energy. Thus, in various embodiments, the nominal ion beam energy can be greater than 500 keV, greater than 1 MeV, greater than 2 MeV, or greater than 5 MeV. In this manner, for a given nominal ion beam energy, the energy-dispersive ion beam 124 can be implanted into the substrate 110 in a manner that delivers a wider implant profile than would be produced by a monoenergetic ion beam having the same nominal ion beam energy.

[0018] FIG2 depicts an ion implanter 200 according to an additional embodiment of the present disclosure. As with the ion implanter 100 , the ion implanter 200 includes an ion source 102 and a linear accelerator 104 disposed downstream of the ion source 102 .

[0019] The ion implanter 200 may include a beam conditioning device 220 disposed downstream of the linear accelerator 104 and including a scanner 202 , a collimator 204 , and an energy dispersive electrode assembly 208 .

[0020] The linear accelerator 104 may include a buncher (not shown) to generate a clustered ion beam 122 from the ion beam 120, which may enter the linear accelerator 104 as a continuous ion beam. The scanner 202 is arranged to receive the clustered ion beam 122 (schematically shown as an ion beam represented by a dark oval) and to transmit a scan signal defined during a scan to scan the clustered ion beam 122 between a first beamline side and a second beamline side. In this example, the clustered ion beam 122 may be a pencil or point ion beam, wherein the clustered ion beam 122 is scanned in the XZ plane as shown. For example, according to some non-limiting embodiments, the scan generator 230 may transmit a scan signal, such as an oscillating voltage, at a scan frequency in the kilohertz range, such as 1 kHz, 2 kHz, or 5 kHz, to a pair of electrode plates that generate an oscillating electric field. Thus, when averaged over a time scale longer than the period of the scan generator 230 for a given scan frequency, the scanned focused ion beam can fan out to form an elongated cross-section along the X-axis. In this embodiment, the energy dispersive electrode assembly 208 comprises a series of AC electrodes coupled to a phase control system that uses information about the scan position of the focused ion beam 122 to select the appropriate phase to achieve the desired energy spread of the focused ion beam 122.

[0021] A collimator 204 is positioned downstream of the scanner 202 to receive the focused ion beam 122, in this case in the form of a fan beam. The collimator 204 can be arranged to shape and output the focused ion beam 122 into a ribbon beam 222 elongated along the X-axis. As further illustrated in FIG2 , an energy dispersive electrode assembly 208 is positioned downstream of the collimator 204 to receive the ribbon beam 222. As described in detail below, the energy dispersive electrode assembly 208 is arranged to apply an RF voltage between a plurality of electrodes along the propagation direction of the ribbon beam to produce energy dispersion therein.

[0022] In the example of FIG2 , the energy-dispersive electrode assembly 208 includes a first ground electrode 212 and a second ground electrode 216, and a powered electrode 214 disposed between the two ground electrodes. An RF power source 234 can supply an RF power signal at a suitable frequency to the powered electrode 214. For example, the RF power source 234 can direct the RF signal to a resonator (not separately shown) that transmits an RF voltage signal to the powered electrode 214. Consequently, an RF voltage is generated between the powered electrode 214 and the first and second ground electrodes 212 and 216. The RF voltage generates an oscillating electric field having a frequency corresponding to the frequency of the RF voltage signal along the Z-axis in the direction of propagation of the ribbon beam 222.

[0023] According to various embodiments of the present disclosure, the energy-dispersive electrode assembly 208 can be arranged as a series of hollow, conductive cylinders designed to encompass the elongated cross-section (along the X-axis) of the ribbon beam 222. In this manner, the energy-dispersive electrode assembly 208 can exhibit some features of known drift tube assemblies used to focus or accelerate ion beams in linear accelerators. When the ribbon beam 222 passes through a given hollow electrode of the energy-dispersive electrode assembly, it experiences a drift region within the hollow electrode where no electric field exists. An oscillating electric field is generated between the first grounded electrode 212 and the powered electrode 214, while an oscillating electric field is also generated between the powered electrode 214 and the second grounded electrode 216. In this manner, the energy-dispersive electrode assembly 208 can define a so-called dual-gap configuration characterized by two accelerating gaps. According to various embodiments of the present disclosure, to achieve the desired effect of dispersing ion energy, the frequency and phase of the oscillating voltage applied to the energy-dispersive electrode assembly 208 are selected taking into account several factors. These factors include the velocity of the ions, the phase dispersion in the ion beam, and the length between the two gaps of the dual-gap configuration.

[0024] When ribbon beam 222 enters the acceleration gap in energy-dispersive electrode assembly 208, the entry time of a given ion beam of ribbon beam 222 will affect how the ions are accelerated or decelerated within the gap. For example, a sinusoidal RF voltage signal can be applied to powered electrode 214, generating a sinusoidal electric field within the acceleration gap. Depending on the instantaneous amplitude and sign of the electric field as the ions pass through the acceleration gap, the ions can be accelerated or decelerated to a lesser or greater degree. Thus, within a given ion beam passing through the acceleration gap, ions at the leading edge of the beam will be accelerated or decelerated to a different degree than ions at the trailing edge of the beam, resulting in a dispersion of the ion energy of ribbon beam 222 during its passage through energy-dispersive electrode assembly 208.

[0025] According to embodiments of the present disclosure, the energy-dispersive electrode assembly 208 can expand or disperse the energy of the ribbon beam 222 by a targeted amount in order to deliver an energy-dispersive ion beam 224 (depicted as a darker, more elongated oval to indicate energy dispersion) to the substrate 110 having a desired range of ion energies. For example, in one scenario, the linear accelerator 104 can impart an ion energy of 1 MeV to the ribbon beam 222 while simultaneously delivering an RF voltage signal having an amplitude of 80 keV to the powered electrode 214. Assuming an initial monoenergetic energy for the ribbon beam 222, the 80 keV signal can cause the energy-dispersive ion beam 224 to impact the substrate 110 with an average energy of 1 MeV and a FWHM of up to 160 keV.

[0026] According to various non-limiting embodiments of the present disclosure, the energy-dispersive electrode assembly can process the ion beam to disperse the ion energy (FWHM) by 1% to 30% for initial ion energies ranging from 1 MeV to 10 MeV. It should be noted that, as discussed above, ribbon beam 222 enters the energy-dispersive electrode assembly as a bunched ion beam, meaning a series of discrete ion packets or bunches separated in time and space. This bunching is achieved by a drift tube arrangement that can operate in a manner similar to the operation of energy-dispersive electrode assembly 108, wherein an RF signal is applied to at least one powered electrode in a series of drift tube electrodes. These drift tube components of the buncher produce two or more accelerating gaps that tend to differentially accelerate / decelerate different ions in the ion beam depending on the time at which different ions pass through the accelerating gap as the RF field oscillates within the accelerating gap. Furthermore, according to various embodiments of the present disclosure, the bunched ion beam (ribbon beam 222) can be focused at a bunching frequency equal to the dispersion frequency output by RF power supply 234. In this manner, the arrival time of the ion beam of ribbon beam 222 may be synchronized with the electric field generated across energy dispersive electrode assembly 208 .

[0027] In a specific embodiment, where the dispersive frequency of the energy-dispersive electrode assembly 208 (e.g., approximately MHz or tens of MHz) is significantly faster than the scanning frequency of the scanner 202 (e.g., approximately 1 kHz), energy dispersion can be imparted to different ion beams of the energy-dispersive ion beam 224 in a uniform and repeatable manner. For example, if the ribbon beam 222 is elongated along a transverse direction (X-axis) perpendicular to the propagation direction (Z-axis), the energy-dispersive electrode assembly 208 can impart uniform energy dispersion to different ion beams of the focused ribbon beam (ribbon beam 222) across the width of the focused ribbon beam along the X-axis. This uniform energy dispersion can be achieved by maintaining a constant phase relationship between the RF signal output by the RF power supply 234 to the energy-dispersive electrode assembly 208 and the arrival times of the beams in the ribbon beam.

[0028] In one embodiment, the ion implanter 200 may include a detector 210 and a phase measurement assembly 232 that measures the phase of the ion beam of the ribbon beam 222 at the entrance of the energy-dispersive electrode assembly 208. The ion implanter 200 may further include a controller 236 that synchronizes this phase information with the RF power supply 234, as shown in FIG2 . Alternatively, the controller 236 may extract or receive a signal from the scan generator 230 to determine the instantaneous scan position (along the X-axis) of the ion beam of the ribbon beam 222. Knowing the instantaneous scan position of the ion beam allows synchronization of the RF signal generated by the RF power supply 234 to ensure that a given ion beam passes through the energy-dispersive electrode assembly 208 at appropriate intervals to produce a target energy dispersion.

[0029] FIG3 depicts an ion implanter 300 arranged in accordance with another embodiment of the present disclosure. As with ion implanters 100 and 200, ion implanter 300 includes an ion source 102 and a linear accelerator 104 positioned downstream of ion source 102. In this embodiment (and in variations of the embodiments of FIG1 , FIG2 , and FIG4 ), the ion implanter may further include a DC acceleration system 103 that accelerates ion beam 120 to a suitable energy, such as 250 keV to 500 keV, according to some non-limiting embodiments, before further acceleration of the ion beam occurs in linear accelerator 104.

[0030] In this embodiment, the energy dispersive device may include a power supply coupled to an energy dispersive electrode assembly 310, which in this case is embodied as a diode assembly including an upstream electrode 312 and a downstream electrode 314. According to some embodiments, an AC voltage may be applied between the upstream electrode 312 and the downstream electrode 314. As shown in FIG3 , the upstream portion 322 of the beamline is electrically isolated from the downstream portion 324 of the beamline. According to various embodiments, either the upstream portion 322 or the downstream portion 324 of the beamline may be electrically floating, including an end station (not shown) that houses the substrate 110. An advantage of this approach is that, in this example, the energy dispersive electrode assembly 310 does not need to receive an RF voltage signal set to the same frequency as the RF voltage applied to the linear accelerator 104. Because there is only one gap in the energy dispersive electrode assembly 310 and the frequency of the energy oscillation can be freely selected within a relatively wide range without causing any other problems, the embodiment of FIG3 is in some respects simpler than the embodiment of FIG2 . However, the embodiment of FIG. 3 shows a more complex mechanical design, requiring a large assembly to be separated from the ground potential and to mount the components on an insulator.

[0031] In embodiments where an AC voltage is applied between upstream electrode 312 and downstream electrode 314, the AC voltage frequency should be carefully selected to avoid aliasing with the sweep frequency and / or bunching frequency of the RF voltage applied to linear accelerator 104 (including the buncher). According to some embodiments, since the bunching frequency applied to the stages of linear accelerator 104 is assumed to be several megahertz or higher, and the sweep frequency of scanner 202 can be in the range of approximately 1 kilohertz, an AC voltage frequency in the range of approximately 100 kilohertz (e.g., 50 kilohertz to 500 kilohertz) can be used for energy-dispersive electrode assembly 310. As shown in the embodiment of FIG3 , a first power supply 332 is coupled to upstream portion 322, or alternatively, a power supply 334 can be coupled to downstream portion 324, each of which can be coupled to controller 330. Since this latter frequency can be significantly lower (approximately 10X or greater) than the bunching frequency of linear accelerator 104, each beam of ions passing through energy-dispersive electrode assembly 310 will experience substantial DC acceleration or deceleration. In other words, for an ion beam focused at a frequency of, say, 13.56 MHz, the beam length, and therefore the propagation time of the ion beam through the energy-dispersive electrode assembly 310, is short enough that the effective field experienced by that beam will appear quasi-constant because the energy-dispersive field frequency is much lower (approximately 100 kHz).

[0032] FIG4 depicts an ion implanter 400 arranged in accordance with another embodiment of the present disclosure. As with ion implanters 100, 200, and 300, ion implanter 400 includes an ion source 102 and a linear accelerator 104 positioned downstream of ion source 102. Unlike the embodiments of FIG2 and FIG3, in this embodiment, ion implanter 400 generates a pencil beam (or spot beam) and directs it toward substrate 110.

[0033] As in the previous embodiment, according to various non-limiting embodiments, multiple stages of the linear accelerator 104 can generate a focused ion beam 122 and accelerate it to a target ion energy, such as 1 MeV, 2 MeV, 5 MeV, or other suitable ion energies. Unlike the previous embodiment, a component, such as an energy selector magnet 404, can be provided to process the focused ion beam 122 into a spot beam having ion energies at target values ​​before impacting the substrate 110. The energy selector magnet 404 (sometimes referred to as a "final energy magnet") is used to provide an independent measurement of the energy of the ions at that point in the beamline. The ion implanter 400 further provides an energy dispersive device, embodied as a high-frequency power supply 412, and an energy dispersive electrode assembly 406. For simplicity, the energy dispersive electrode assembly 406 is illustrated as two electrodes. However, according to various embodiments, energy-dispersive electrode assembly 406 may be embodied as a double-gap drift tube assembly similar to energy-dispersive electrode assembly 208, or alternatively, as a triple-gap electrode assembly providing two powered electrodes between two ground electrodes. Thus, high-frequency power supply 412 can generate RF voltage at the same frequency that power supply assembly 410 provides to the various stages of the buncher and linear accelerator 104. The advantage of the architecture of FIG4 is that, because the path length of ions in the bunched ion beam 122 from the linear accelerator to energy-dispersive electrode assembly 406 is constant, the phase relationship between the two is also constant. To achieve the desired and repeatable acceleration or deceleration of a series of ion beams, the phase of the accelerating or decelerating AC field must be matched to the arrival time of the ion beams acting on the AC field. In other words, each successive ion beam arriving at energy-dispersive electrode assembly 406 should experience the same amplitude and phase of the applied AC field. Thus, by establishing the same frequency for the focusing signal generated by power supply assembly 410 and the dispersion signal sent by high-frequency power supply 412, and by properly synchronizing the focusing and dispersion signals, each successive ion beam along a given ion path will be processed identically by the applied AC field from the energy-dispersive electrode assembly. In the configuration of FIG2 , this phase relationship varies as the path lengths of the different ion paths vary depending on the scan angle at that moment, whereas in the configuration of FIG4 , there is no high-speed scanning to change the path length. Consequently, controller 414 can more easily synchronize the acceleration of the focused ion beam 122 by the linear accelerator 104 and the energy dispersion performed by the energy-dispersive electrode assembly 406.

[0034] 4 , the ion implanter 400 may include a substrate stage 408 configured to rotate the substrate 110 about the Z-axis and to translate the substrate along a vertical axis, such as the X-axis. In this manner, while the focused ion beam 122 may expose only a portion of the substrate 110 in a given situation, the entire substrate 110 or any target portion thereof may be exposed to the energy-dispersive ion beam 420 by appropriately rotating and / or translating the substrate 110.

[0035] In view of the foregoing, at least the following advantages are achieved by the embodiments disclosed herein. A first advantage achieved by the ion implanter of the present embodiment is the ability to achieve a wider implant profile in a given implant process than is possible using known single-energy, high-energy implanters. Another advantage is the ability to easily adjust the width of the implant profile simply by adjusting the voltage applied to the energy dispersive assembly.

[0036] Although certain embodiments of the present disclosure have been described herein, the present disclosure is not limited thereto, as the present disclosure is as broad in scope as the art will allow, and the specification should be construed accordingly. Therefore, the above description should not be construed as limiting. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.

[0037] 100, 200, 300, 400: ion implanters 102: ion source 103:DC Acceleration System 104: Linear Accelerator 106: Downstream components 108: Energy dispersive electrode assembly 110: Base 120: Ion Beam 122: Clustered ion beam 124, 224, 420: Energy-dispersed ion beam 130: Power Source 202: Scanner 204: Collimator 208, 310, 406: Energy dispersive electrode assembly 210: Detector 212: first ground electrode 214: Power supply electrode 216: Second ground electrode 220: Beam adjustment device 222: Ribbon 230: Scan Generator 232:Phase measurement component 234:RF Power Supply 236, 330, 414: Controller 312: Upstream electrode 314: Downstream electrode 322: Upstream 324: Downstream part 332: First Power Source 334: Power Supply 404: Energy Selective Magnet 408: Base platform 410: Power supply components 412: High-frequency power supply

Claims

1. An ion implantation device, comprising: An ion source, arranged to generate an ion beam; A scanner is positioned downstream of the ion source along the direction of travel of the ion beam; An energy dispersion electrode assembly, disposed downstream of the scanner, is provided for receiving the ion beam and applying a time-varying voltage bias signal between a plurality of electrodes of the energy dispersion electrode assembly to generate energy dispersion of the ion beam.

2. The ion implantation device as claimed in claim 1, wherein the energy dispersion depends on the time-varying voltage bias signal.

3. The ion implanter as claimed in claim 1, wherein the energy dispersion, for nominal ion energy, provides a first implantation profile in the substrate that is wider than a second implantation profile generated in the substrate when a monoenergetic ion beam of the same nominal energy is directed to the substrate.

4. The ion implantation device as claimed in claim 1, wherein the energy distribution of the energy dispersion is equal to 1% to 30% of the initial energy of the ion beam.

5. The ion implantation device as claimed in claim 1, wherein the time-varying voltage bias signal is an RF voltage.

6. The ion implantation device as claimed in claim 1, wherein the time-varying voltage bias signal is an AC voltage.

7. The ion implantation device as claimed in claim 1, wherein the scanner is operated at a first frequency to scan the ion beam, and wherein a time-varying voltage bias signal is applied at a second frequency at least ten times greater than the first frequency.

8. The ion implantation device as claimed in claim 7, wherein the ion beam extends in a transverse direction perpendicular to the local propagation direction, and wherein the energy dispersing electrode assembly is arranged to uniformly disperse energy onto the ion beam across the width of the ion beam along the transverse direction.

9. The ion implantation device as claimed in claim 1 further includes a linear accelerator disposed between the ion source and the energy dispersing electrode assembly and arranged to increase the energy of the ion beam.

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