Incident angle measurement system

Abstract

Disclosed are systems and methods capable of measuring the angle of incidence of an ion beam, particularly an ion beam comprising heavier ions. Specifically, a system for measuring the angle of incidence is disclosed. In one embodiment, X-rays are used rather than ions to determine the channeling direction. In another embodiment, a workpiece is constructed at least partially of a material having a high molecular weight, enabling measurement of heavier ion beams. Furthermore, in another embodiment, ion beam parameters are measured across the entire beam, enabling further adjustment of ion implantation system components to form a more uniform beam.

Description

Technical Field

[0001] Embodiments of the present disclosure relate to systems and methods for determining the angle of incidence of an ion beam, and more particularly, to using channeling to determine the angle of incidence. Background Art

[0002] Ion beams are used to implant dopants into a workpiece, such as a silicon substrate. These ion beams can be formed using an ion source that produces ions of the desired species. These ions are extracted and manipulated by various components that select the desired species and direct the ions toward the workpiece.

[0003] The resulting ion beam strikes the workpiece at one or more angles of incidence, depending on the geometry of the ion beam. In certain embodiments, it may be advantageous to accurately measure the angle of incidence of the ions on the workpiece. For example, in certain embodiments, there are implantation processes in which tight control of the angle of incidence is required.

[0004] One way to determine the angular distribution of an ion beam is by using Rutherford backscattering. When ions strike a workpiece, some are scattered. As the ions become aligned with the channels in the workpiece's crystalline structure, the amount of scattered ions decreases. For example, if the angle of incidence of the ions is perfectly parallel to the channels in the workpiece, backscattering will be minimized.

[0005] However, Rutherford backscattering is limited to embodiments where the molecular weight of the implanted ions is smaller than the molecular weight of the workpiece. Thus, Rutherford backscattering may not be possible with phosphorus or arsenic ion beams and silicon workpieces.

[0006] Therefore, it would be beneficial if a system and method existed to accurately measure the angle of incidence of an ion beam. Furthermore, it would be advantageous if beams containing heavier ions, such as arsenic and phosphorus, could be measured. Finally, it would be beneficial if such a system and method could also be used to improve the accuracy with which the angular distribution of an ion beam meets process requirements. Summary of the Invention

[0007] Disclosed are systems and methods capable of measuring the angle of incidence of an ion beam, particularly an ion beam comprising heavier ions. In one embodiment, X-rays are used rather than backscattered ions to determine the channeling direction. In another embodiment, a workpiece is constructed at least in part of a material having a high molecular weight, enabling measurement of heavier ion beams. Furthermore, in another embodiment, ion beam parameters are measured across the entire beam, enabling further adjustment of ion implantation system components to form a more uniform beam.

[0008] According to one embodiment, an angle of incidence measurement system is disclosed. The angle of incidence measurement system includes: an ion implantation system that generates an ion beam; a movable workpiece holder for holding a workpiece; a detector for capturing emission from the workpiece, wherein the detector includes a plurality of sensors arranged along the width of the ion beam (referred to as the X-direction); and a controller, wherein the controller rotates the movable workpiece holder to change the X-angle and receives an output from the detector at each of the plurality of X-angles, and wherein at each of a plurality of positions along the X-direction, the angle of incidence of the ion beam in the X-direction is determined to be at the X-angle at which the output received from the corresponding sensor is minimum. In one embodiment, the plurality of sensors include Faraday sensors, wherein each of the Faraday sensors captures backscattered ions from a portion of the ion beam. In some embodiments, the plurality of sensors include X-ray detectors, wherein each of the X-ray detectors captures X-rays emitted from a portion of the workpiece. In some embodiments, the controller calculates the angle of incidence spread in the X-direction based on the outputs received from the plurality of sensors. In some embodiments, the ion implantation system includes an extraction optical device disposed near the ion source, wherein the controller adjusts the positioning of the extraction optical device to correct for the incidence angle spread. In some embodiments, the ion implantation system includes a quadrupole lens disposed downstream of the ion source, wherein the controller adjusts the focusing effect of the quadrupole lens to correct for the incidence angle spread. In some embodiments, the ion implantation system includes a collimator disposed downstream of the ion source, wherein the controller adjusts the current supplied to the collimator to correct for the incidence angle spread. In some embodiments, the controller rotates the movable workpiece holder to change the Y angle and receives an output from the detector at each of a plurality of Y angles, and wherein at each of a plurality of positions along the X direction, the angle of incidence of the ion beam in the Y direction is determined to be at the Y angle at which the output received from the corresponding sensor is minimum. In some embodiments, the controller calculates the incidence angle spread in the Y direction based on the outputs received from the plurality of sensors.

[0009] According to another embodiment, an incident angle measurement system is disclosed. The incident angle measurement system includes: an ion implantation system that generates an ion beam; a movable workpiece holder for holding a workpiece; a detector, wherein the detector includes one or more X-ray detectors; and a controller, wherein the controller rotates the movable workpiece holder to change the X-angle and receives an output from the detector at each of a plurality of X-angles, and wherein the incident angle of the ion beam is determined to be the X-angle at which the output from the detector is minimum. In some embodiments, the ion beam includes ions having a higher atomic mass than the workpiece. In some embodiments, the ion beam includes phosphorus or arsenic ions, and the workpiece includes a silicon workpiece.

[0010] According to another embodiment, an incident angle measurement system is disclosed. The incident angle measurement system includes: an ion implantation system that generates an ion beam; a movable workpiece holder for holding a workpiece; a detector; a single crystal target material, different from the workpiece, disposed on the movable workpiece holder; and a controller, wherein the controller rotates the movable workpiece holder to change an X angle and receives an output from the detector at each of a plurality of X angles, and wherein the incident angle of the ion beam is determined to be the X angle at which the output from the detector is minimum. In some embodiments, the single crystal target material is disposed on the movable workpiece holder at a position beyond an edge of the workpiece, such that the single crystal target material can be implanted by the ion beam when the workpiece is disposed on the movable workpiece holder. In some embodiments, the single crystal target material includes an element having a higher atomic mass than the workpiece. In some embodiments, the single crystal target material is selected from the group consisting of tungsten, molybdenum, tantalum, germanium, gallium arsenide, gallium nitride, and indium phosphide. In some embodiments, the controller rotates the movable workpiece holder to change the Y angle, and the angle of incidence of the ion beam is determined to be at the Y angle at which the output from the detector is minimized. In some embodiments, the single crystal target material is disposed on the movable workpiece holder in place of the workpiece. In some embodiments, the single crystal target material has the shape and size of the workpiece. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] For a better understanding of the present disclosure, reference is made to the accompanying drawings which are incorporated herein by reference and wherein:

[0012] Figure 1 is an ion implantation system according to one embodiment.

[0013] Figure 2 is an incident angle measurement system according to one embodiment.

[0014] Figure 3Ais a side view of an incident angle measurement system according to another embodiment.

[0015] Figure 3B yes Figure 3A Top view of the incident angle measurement system shown.

[0016] Figure 4 Shown is a single crystal target material mounted to a movable workpiece holder. DETAILED DESCRIPTION

[0017] As described above, the present system can be used to perform channeling implants or to measure and adjust an ion beam in an ion implantation system. In some embodiments, the ion beam can be a scanned ribbon beam formed using a spot beam ion implantation system.

[0018] like Figure 1 As shown in FIG, an ion implantation system includes an ion source 100 including a plurality of chamber walls defining an ion source chamber in which a plasma is formed. In certain embodiments, the ion source 100 may be a radio frequency (RF) ion source. In such an embodiment, an RF antenna may be positioned against a dielectric window. This dielectric window may include part or all of one of the chamber walls. The RF antenna may comprise a conductive material such as copper. An RF power supply is in electrical communication with the RF antenna. The RF power supply may supply an RF voltage to the RF antenna. The power supplied by the RF power supply may be between 0.1 kW and 10 kW and may be any suitable frequency, such as between 1 MHz and 100 MHz. Furthermore, the power supplied by the RF power supply may be pulse modulated.

[0019] In another embodiment, a cathode is disposed within the ion source chamber. A filament is disposed behind the cathode and is energized to emit electrons. These electrons are attracted to the cathode, which in turn emits the electrons into the ion source chamber. Because the cathode is indirectly heated by the electrons emitted from the filament, this cathode is referred to as an indirectly heated cathode (IHC).

[0020] Other embodiments are also possible. For example, the plasma can be generated in various ways, such as using a Bernasion source, a capacitively coupled plasma (CCP) source, a microwave, or an electron-cyclotron-resonance (ECR) ion source. The method for generating the plasma is not limited by this disclosure.

[0021] One chamber wall, referred to as the extractor plate, includes an extraction orifice. The extraction orifice may be an opening through which ions 1 generated in the ion source chamber are extracted and directed through the mass analyzer 120 and toward the workpiece 10. The extraction orifice may have any suitable shape. In certain embodiments, the extraction orifice may be shaped as an oval or rectangular shape, having one dimension, referred to as the width (x dimension), which may be substantially larger than a second dimension, referred to as the height (y dimension).

[0022] Disposed outside and near the extraction orifice of the ion source 100 is an extraction optical device 110. In some embodiments, the extraction optical device 110 includes one or more electrodes. Each electrode can be a single conductive component in which an orifice is disposed. Alternatively, each electrode can include two conductive components spaced apart so as to form an orifice between the two components. The electrodes can be a metal such as tungsten, molybdenum, or titanium. One or more of the electrodes can be electrically connected to ground. In some embodiments, one or more of the electrodes can be biased using an electrode power supply. The electrode power supply can be used to bias one or more of the electrodes relative to the ion source so as to attract ions through the extraction orifice. The extraction orifice is aligned with the orifice in the extraction optical device 110 so that the ion 1 passes through both orifices.

[0023] Located downstream of the extraction optics 110 is a mass analyzer 120. The mass analyzer 120 uses a magnetic field to guide the path of the extracted ion beam 1. The magnetic field affects the flight path of the ions based on their mass and charge. A mass resolving device 130 with a resolving aperture 131 is located at the output or distal end of the mass analyzer 120. By appropriately selecting the magnetic field, only ions 1 of the selected mass and charge will be directed through the resolving aperture 131. Other ions will impact the mass resolving device 130 or the walls of the mass analyzer 120 and will not travel further in the system.

[0024] In some embodiments, ions passing through the mass resolving device 130 may form a spot beam.

[0025] The spot beam may then enter a scanner 140 disposed downstream of the mass resolving device 130. The scanner 140 fans the spot beam into a plurality of diverging beamlets. The scanner 140 may be electrostatic or magnetic.

[0026] In other embodiments, the ions passing through the mass resolving device 130 may form a ribbon ion beam, wherein a broad beam is delivered throughout the ion implantation system. For example, the ribbon beam may be extracted from the ion source 100. In this embodiment, the scanner 140 is not required.

[0027] In certain embodiments, the collimator 150 then converts these diverging beamlets into a plurality of parallel beamlets that are directed toward the workpiece 10. The collimator 150 may be a magnet. In this embodiment, current is applied to the collimator magnet to steer the beamlets passing therethrough.

[0028] In other embodiments, a system of electrostatic lenses may act as the collimator 150 and transform the diverging beam into multiple parallel beamlets.

[0029] The workpiece 10 is disposed on a movable workpiece holder 160 located downstream of the collimator 150 .

[0030] In some embodiments, one or more quadrupole lenses 190 may be positioned along the path of the ions. For example, a quadrupole lens 190 may be positioned before the mass analyzer 120, after the mass analyzer 120, after the mass resolving device 130, or in other locations.

[0031] In some embodiments, the direction of the ion beam is referred to as the Z direction, the direction perpendicular to this direction and horizontal can be referred to as the X direction, and the direction perpendicular to the Z direction and vertical can be referred to as the Y direction. In this example, it is assumed that the scanner 140 scans the spot beam in the X direction while the movable workpiece holder 160 translates in the Y direction.

[0032] A detector 170 may be positioned adjacent to the workpiece 10. Detector 170 may be used to measure certain parameters associated with the ion beam 1. In some embodiments, detector 170 may include one or more Faraday devices arranged in a linear fashion. In another embodiment, detector 170 may include multiple X-ray detectors. The operation of detector 170 is described in greater detail below.

[0033] A controller 180 is also used to control the system. The controller 180 has a processing unit 181 and an associated memory device 182. The memory device 182 contains instructions 183 that, when executed by the processing unit, enable the system to perform the functions described herein. The memory device 182 can be any non-transitory storage medium, including non-volatile memory, such as flash read-only memory (ROM), electrically erasable ROM, or other suitable devices. In other embodiments, the memory device 182 can be a volatile memory such as random access memory (RAM) or dynamic random access memory (DRAM). In some embodiments, the controller 180 can be a general-purpose computer, an embedded processor, or a specially designed microcontroller. The actual implementation of the controller 180 is not limited by this disclosure.

[0034] As described in more detail below, the controller 180 may communicate with the detector 170, the scanner 140, and the movable workpiece holder 160. The controller 180, the detector 170, and the movable workpiece holder 160 may be part of an angle of incidence measurement system.

[0035] Figure 2 A simplified diagram illustrating the operation of the angle of incidence measurement system 200 is shown. As described above, the controller 180 communicates with the movable workpiece holder 160 and the detector 170. The ion beam 1 is directed toward the workpiece 10 mounted on the movable workpiece holder 160. The detector 170 is positioned near the workpiece 10 so as to receive emissions from the workpiece 10 as the workpiece 10 is implanted by the ion beam 1. For example, the emissions may be backscattered ions or X-rays. The controller 180 rotates the movable workpiece holder 160 about the Y-axis or the X-axis. At each rotation angle, the detector 170 detects the emissions and transmits this information to the controller 180. The controller 180 may record this information as a function of the rotation angle. After this process is completed, the result may be a set of data showing a minimum value, such as shown in graph 210. It should be noted that the controller 180 does not necessarily generate the graph 210, but rather the graph 210 is shown to illustrate the expected output from the detector 170 as the movable workpiece holder 160 rotates.

[0036] If the controller 180 repeats this process by rotating about both the X and Y axes, the X angle (X') and Y angle (Y') corresponding to the orientation of the movable workpiece holder 160 that channels the beam into the workpiece 10 can be determined with high accuracy. Rotation about the X axis results in a change in the Y angle, while rotation about the Y axis results in a change in the X angle.

[0037] Furthermore, the system may also include the ability to alter the beam angle based on the results of the incident angle measurement system 200. For example, based on the results obtained, the controller 180 may manipulate the current to the collimator 150 or another component in the ion implantation system. Thus, in certain embodiments, an incident angle measurement and control system is disclosed.

[0038] For example, if the ion beam at the workpiece is found to be diverging in the X direction, this can be compensated for by increasing the current to the collimating magnets. This increase in current will have two effects: it will increase the average bending angle and increase the amount of convergence. Once the correct current is achieved to achieve perfect parallelism (neither divergence nor convergence) and the average angle is measured, the workpiece 10 can be rotated to the desired orientation of the ion beam, and since the ion beam is now parallel, the desired beam incidence angle will be exactly the same across the width of the flat workpiece.

[0039] In another example, if the beam at the workpiece is found to have an upward direction on one side and a less upward direction on the other side, the ion beam can be moved in the vertical direction by adjusting the positioning of the electrodes in the extraction optics 110 to direct the ion beam 1 closer to the mid-plane of the collimating magnets and achieve a more uniform vertical (y') angle over the sweep (x). Once a uniform angle is achieved, the workpiece can be tilted relative to this uniform angle to a desired orientation.

[0040] This system can also detect angular changes that may not be correctable by steering the beam, but may require manual maintenance intervention (eg, alignment or component replacement).

[0041] The present disclosure sets forth various embodiments that enable improved measurement and optional control of the angle of incidence of an ion beam.

[0042] In a first embodiment, Rutherford backscattering is used to determine the angle of incidence of the ion beam in a plurality of locations. Figure 3A A side view of the movable workpiece holder 160 is shown, and Figure 3B A top view of the movable workpiece holder 160 is shown. A workpiece 10 is disposed on the movable workpiece holder 160. In some embodiments, the workpiece 10 may be a silicon substrate. In this embodiment, the detector 170 includes one or more Faraday sensors 171 spaced apart in the X direction. In some embodiments, the one or more Faraday sensors 171 may also be spaced apart in the Y direction. In the case of a spot beam, when the beam is moved in the X direction (i.e., in the Figure 3BAs the ion beam 1 is scanned (in a vertical direction) across the ion beam 1, each of the Faraday sensors 171 sequentially receives emissions from the workpiece 10. In the case of a ribbon ion beam, all of the Faraday sensors 171 receive emissions simultaneously. The controller 180 is in communication with each of these Faraday sensors 171 and is able to create a graph similar to graph 210 for each of the Faraday sensors 171. After all data has been collected from the Faraday sensors 171, the controller 180 can rotate the movable workpiece holder 160 about the X-axis and / or the Y-axis. In this way, the controller 180 can determine the angle of incidence (i.e., the X angle (X') and / or the Y angle (Y')) for multiple locations along the length of the ion beam 1.

[0043] As described above, the implant system forms a wide beam as a ribbon beam or a scanned spot beam. For many beam adjustment problems, it is helpful to verify that the angles (i.e., X' and Y') are uniform across the width of the beam. If there is overall divergence or convergence (when or shows an overall upward or downward slope), this can be corrected by adjusting the current to the collimator 150.

[0044] As described above, the X angle along the ion beam 1 (i.e., X'(x)) can be determined using multiple detectors 170, each of which is specific to a limited range of x across the width of the ion beam 1. As described above, the X tilt angle can be varied, and a minimum value for each of the multiple Faraday sensors 171 can be identified. In this way, multiple points on the X'(x) curve can be obtained and any convergence or divergence in the X direction can be corrected. Similarly, the Y tilt angle can be varied, and a minimum value for each of the multiple Faraday sensors 171 can be identified. In this way, multiple points on the Y'(x) curve can be obtained and the vertical shear distortion of the probe beam can be detected.

[0045] Furthermore, if there is a fixed offset in the X or Y angle, the movable workpiece holder 160 can be tilted to ensure that the ion beam 1 strikes the workpiece 10 at a perpendicular angle. In other words, instead of adjusting the ion beam 1 to remove any constant angular offset, the movable workpiece holder 160 can be adjusted to compensate for this offset.

[0046] Furthermore, this embodiment may also be able to measure the angular spread in both the x-direction and the y-direction as a function of x: σ x′ (x) and σ y′(x). To achieve the maximum amount of channeling, it can be advantageous to minimize these angular spreads. The magnitude of the angular spread is typically set by the details of the beam optics and can be manipulated by variables such as the precise positioning of the extraction electrodes or the focusing effect of various quadrupole lenses 190 that may be included in the beamline for this purpose. At the workpiece 10, the spot beam is typically adjusted to a minimum size because this gives the most efficient dose. However, adjusting for minimum angular spread may result in a larger spot size and less efficient scanning, but will result in more efficient channeling and, therefore, superior processing results.

[0047] Thus, in one embodiment, an angle of incidence measurement and control system is disclosed that captures angle of incidence information at multiple locations along the width of an ion beam. This is accomplished using multiple detectors 170 spaced apart in the X direction. In another embodiment, a single detector 170 may be utilized. In this case, the detector 170 is moved to different locations in the X direction to collect data across the width of the ion beam.

[0048] In another embodiment, the present application allows for the use of an ion beam that includes heavier species with Rutherford backscattering. In one embodiment, a target workpiece made of a heavier crystalline material (e.g., tungsten) can be used. Specifically, as described above, the use of a silicon substrate limits the possible species of the ion beam to species with an atomic weight less than that of silicon. Therefore, a different single crystal material (e.g., tungsten) or some other higher atomic number metal or compound can be used as the target workpiece. This target workpiece can be in the shape of a silicon wafer and can be clamped to the movable workpiece holder 160 by an electrostatic clamp. In this embodiment, the measurement will be performed in the same manner as described above.

[0049] In another embodiment, the target material may be added to the movable workpiece holder. In certain embodiments, the target material may be disposed on the movable workpiece holder 160 at a location beyond the edge of the workpiece 10 . Figure 4One possible geometry is shown in FIG. This figure shows a movable workpiece holder 260 in which a strip of single crystal target material 270 is positioned beneath the silicon workpiece 10 but is mounted to the movable workpiece holder 260 in a manner such that it is articulated by a tilt mechanism that controls the tilt of the workpiece 10. The single crystal target material 270 can be attached to the movable workpiece holder 260 in a manner that provides a well-defined relationship between the channeling direction of the single crystal target material 270 and the positioning of the movable workpiece holder 260. The single crystal target material 270 can be at least as wide as the workpiece 10, enabling it to provide data across the entire width of the ion beam 1. Thus, the width of the single crystal target material 270 can be greater than the width of the workpiece 10. The height of the single crystal target can be similar to or greater than the height of the ion beam, which can vary from approximately 5 mm to 50 mm. The thickness of the single crystal target can be at least thick enough to block the ion beam 1. A typical range for high-energy ions is in the range of 1 micron to 20 microns.

[0050] Since ions with atomic masses higher than silicon will be backscattered, high atomic mass crystal targets are advantageous for Rutherford backscattering measurements. The advantage of using metal targets is that crystal damage accumulates much more slowly in the target than in covalently bonded structures. Furthermore, using aluminum targets and detecting X-rays rather than backscattered ions offers an advantage over tungsten because it avoids the risk of harmful contamination of most semiconductors.

[0051] Thus, in this embodiment, the system utilizes a target material that is a single crystal material with a higher atomic mass than silicon, such as tungsten, molybdenum, tantalum, germanium, gallium arsenide, gallium nitride, indium phosphide, or any other material that can be obtained as a single crystal or epitaxially deposited on some other single crystal substrate. This single crystal target material 270 can be used to measure the angle of incidence at a specific location, such as the middle of the ion beam. In another embodiment, the target material can be used with Figure 3A to Figure 3B The illustrated detector 170 utilizes this single crystal target material 270 together so that the angle of incidence is measured at multiple locations along the width of the ion beam.

[0052] The single crystal target material 270 may be disposed in other locations on the movable workpiece holder 260. For example, in one embodiment, the single crystal target material 270 is disposed in a location where the workpiece 10 is typically positioned. In one embodiment, the single crystal target material 270 may have the same size and shape as a typical workpiece. In another embodiment, the single crystal target material 270 may have a different shape and size, but may be sized such that it has a width at least as wide as the workpiece and a height at least as tall as the ion beam 1.

[0053] According to another embodiment, the detector 170 does not use Rutherford backscattering. Instead, the detector 170 includes one or more X-ray detectors. Using X-ray detectors instead of Faraday sensors avoids the limitation on the relative masses of ions and targets.

[0054] The process of particle-induced X-ray emission (PIXE) occurs when high-energy ions impact molecules and excite inner shell electrons. When the electrons fall back to their ground state, they emit X-rays whose wavelength is determined by the X-ray's binding energy and is therefore characteristic of the material in the target workpiece. When the high-energy ions channelize in the crystal, this interaction with the tightly bound electrons is greatly reduced. Since it is these inner shell electrons that produce the highest energy (K-line) X-rays, the X-ray yield can be very sensitive to the channeling conditions. In other words, when the ion beam 1 enters a channel in the workpiece, the amount of X-rays produced decreases.

[0055] In other words, similar to Rutherford backscattering, when ions are implanted into the trenches of the crystalline structure, the emission of X-rays is minimal. Therefore, in some embodiments, the detector 170 may include one or more X-ray detectors. Recent developments in X-ray detectors have resulted in compact units that do not require liquid nitrogen and have an energy resolution sufficient to eliminate background from other sources.

[0056] Interestingly, X-ray emission occurs regardless of the relative masses of the ions and the workpiece. In other words, an ion beam containing heavier ions (such as phosphorus or arsenic) can implant a silicon workpiece and still produce X-rays. Thus, using PIXE enables the use of silicon workpieces that take into account the species being implanted.

[0057] It should be noted that in any of the embodiments disclosed herein, an X-ray detector may be used as the detector 170. In other words, in Figure 3A and Figure 3B In the illustrated embodiment, an X-ray detector can be used. Additionally, an X-ray detector can be used for heavier targets or lighter targets if desired.

[0058] The embodiments described above in this application can have many advantages. High energy implants benefit from using intentionally channeled angles of incidence for at least two reasons. First, for a given energy, the ions penetrate deeper into the workpiece. Second, the channeled angles of incidence cause less crystal damage.

[0059] However, intentional channeling implants utilize extremely precise angle control (<0.05° or approximately 1 millirad) for both the average beam angle and the angular spread within the ion beam. Existing metrology methods based on high aspect ratio apertures and Faraday to measure ion current are unable to achieve this accuracy. Furthermore, current systems are limited by constraints on the relative masses of ions and silicon workpieces in Rutherford backscattering applications.

[0060] Through Figure 3A and Figure 3B By using multiple detectors in the X direction as shown in , the beam angle and angular spread across the entire ion beam can be determined and controlled. Specifically, the current to the collimator 150 can be adjusted to meet the constraints of the channeling implant. Alternatively or additionally, the precise positioning of the extraction optics and the focusing effect of the quadrupole lens can be adjusted to meet these constraints. Thus, the present system enables channeling implantation to be performed across the entire workpiece.

[0061] Furthermore, the use of an X-ray detector enables the use of the same measurement and control system regardless of the desired ion species. Thus, measurements can be made using heavier ions and silicon workpieces if desired.

[0062] The scope of the present disclosure is not limited by the specific embodiments described herein. In fact, through the above description and the accompanying drawings, it will be apparent to those of ordinary skill in the art that, in addition to the embodiments and modifications described herein, various other embodiments of the present disclosure and various modifications to the present disclosure will also be apparent. Therefore, these other embodiments and modifications are intended to fall within the scope of the present disclosure. In addition, although the present disclosure has been described herein in the context of specific embodiments in a specific environment for specific purposes, those of ordinary skill in the art will recognize that the utility of the present disclosure is not limited thereto and that the present disclosure may be beneficially implemented in any number of environments for any number of purposes. Therefore, the claims described above should be understood in light of the full scope and spirit of the present disclosure described herein.

Claims

1. An incident angle measurement system, comprising: ion implantation systems, which produce wide ion beams; a movable workpiece holder for holding a workpiece; a detector for capturing emission from the workpiece, wherein the detector comprises a plurality of sensors arranged along a width of the ion beam, wherein a direction along the width of the ion beam is referred to as an X direction; as well as a controller, wherein the controller rotates the movable workpiece holder to change the X angle and receives an output from the detector at each of a plurality of X angles, and wherein at each of a plurality of positions along the X direction, the angle of incidence of the ion beam in the X direction is determined to be at the X angle at which the output received from the corresponding sensor is minimum. 2 . The incident angle measurement system of claim 1 , wherein the plurality of sensors comprise Faraday sensors, wherein each of the Faraday sensors captures backscattered ions from a portion of the ion beam. 3 . The incident angle measurement system of claim 1 , wherein the plurality of sensors comprise X-ray detectors, wherein each of the X-ray detectors captures X-rays emitted from a portion of the workpiece. 4 . The incident angle measurement system according to claim 1 , wherein the controller calculates the incident angle spread in the X direction based on the outputs received from the plurality of sensors.

5. The incident angle measurement system of claim 4, wherein the ion implantation system includes extraction optics disposed proximate an ion source, wherein the controller adjusts positioning of the extraction optics to correct for the incident angle spread.

6. The incident angle measurement system of claim 4, wherein the ion implantation system includes a quadrupole lens disposed downstream of an ion source, wherein the controller adjusts a focusing effect of the quadrupole lens to correct for the incident angle spread.

7. The incident angle measurement system of claim 4, wherein the ion implantation system includes a collimator disposed downstream of an ion source, wherein the controller adjusts current supplied to the collimator to correct for the incident angle spread.

8. The incident angle measurement system of claim 1 , wherein the controller rotates the movable workpiece holder to change the Y angle and receives an output from the detector at each of a plurality of Y angles, and wherein at each of a plurality of positions along the X direction, the incident angle of the ion beam in the Y direction is determined to be at the Y angle at which the output received from the corresponding sensor is minimum. 9 . The incident angle measurement system according to claim 8 , wherein the controller calculates the incident angle spread in the Y direction based on the outputs received from the plurality of sensors.

10. An incident angle measurement system, comprising: ion implantation systems, which generate ion beams; a movable workpiece holder for holding a workpiece; a detector, wherein the detector comprises one or more X-ray detectors; as well as a controller, wherein the controller rotates the movable workpiece holder to change the X angle and receives an output from the detector at each of a plurality of X angles, and wherein the angle of incidence of the ion beam is determined to be at the X angle at which the output from the detector is minimum, The output of the detector represents the amount of X-rays emitted by the workpiece and received by the detector. 11 . The incident angle measurement system of claim 10 , wherein the ion beam includes ions having a higher atomic mass than the workpiece.

12. The incident angle measurement system of claim 11, wherein the ion beam comprises phosphorus or arsenic ions, and the workpiece comprises a silicon workpiece.

13. An incident angle measurement system, comprising: ion implantation systems, which produce wide ion beams; a movable workpiece holder for holding a workpiece; a detector for capturing the emission, where the emission is ions or X-rays; a single crystal target material, distinct from the workpiece, disposed on the movable workpiece holder; as well as a controller, wherein the controller rotates the movable workpiece holder to change the X angle and receives an output from the detector at each of a plurality of X angles, and wherein the angle of incidence of the ion beam is determined to be at the X angle at which the output from the detector is minimum.

14. The incident angle measurement system of claim 13, wherein the single crystal target material is disposed on the movable workpiece holder at a position beyond an edge of the workpiece so that the single crystal target material can be implanted by the ion beam when the workpiece is disposed on the movable workpiece holder. 15 . The incident angle measurement system of claim 13 , wherein the single crystal target material comprises an element having a higher atomic mass than the workpiece. 16 . The incident angle measurement system of claim 13 , wherein the single crystal target material is selected from the group consisting of tungsten, molybdenum, tantalum, germanium, gallium arsenide, gallium nitride, and indium phosphide.

17. The incident angle measurement system of claim 13, wherein the controller rotates the movable workpiece holder to change a Y angle, and wherein the incident angle of the ion beam is determined to be at the Y angle at which the output from the detector is minimum. 18 . The incident angle measurement system according to claim 13 , wherein the single crystal target material is provided on the movable workpiece holder instead of the workpiece.

19. The incident angle measurement system of claim 18, wherein the single crystal target material has a shape and size of the workpiece.

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