X-ray refraction angle confirmation in ion implanter

Abstract

An ion implanter that facilitates directing an ion beam into a crystalline structure of a workpiece is disclosed. The ion implanter comprises: an ion source for generating an ion beam; the bedplate is used for supporting a workpiece with a crystal structure; an X-ray source for generating an X-ray beam wherein at least a portion of the X-ray beam impinges on the workpiece to generate diffracted X-rays; an X-ray detector positioned to receive the diffracted X-rays; and a controller in communication with the X-ray source, the platen, and the X-ray detector. The controller includes instructions that enable the ion implanter to perform a wobble curve test after the workpiece is disposed on the platen and calculate an orientation of the platen for the ion implantation process based on results of the wobble curve test to facilitate directing the ion beam into the crystalline structure of the workpiece.

Description

[0001] This application claims priority to U.S. Patent Application Serial No. 18 / 387,987, filed on November 8, 2023, which is a partial continuation of U.S. Patent Application Serial No. 18 / 091,041, filed on December 29, 2022. The disclosures of these U.S. patent applications are hereby incorporated by reference in their entireties.

[0002] Embodiments of the present disclosure relate to an ion implanter that performs angular alignment using X-ray diffraction (XRD) prior to implantation. Background Art

[0003] For many years, silicon has been the primary material used for semiconductor workpieces. Silicon workpieces have been used to form transistors, memory elements, amplifiers, and other devices.

[0004] Recently, alternative workpieces with various crystalline structures are being used to fabricate more semiconductor devices. Some of these alternative workpieces include silicon carbide (SiC), gallium nitride (GaN), gallium arsenide (GaAs), and other materials.

[0005] In some scenarios, it is desirable to perform an ion implantation process in a manner such that ions are guided into channels of a crystalline structure, which requires accurate alignment of the ion beam with the crystal lattice. For silicon workpieces, the orientation of the workpiece is well-known. However, other workpieces can be different. For example, silicon carbide has a more complex crystalline structure than silicon. In fact, silicon carbide can form various different polytypes with different crystalline structures.

[0006] In addition, the specifications associated with SiC workpieces can be difficult to understand, which complicates the identification of the orientation of the workpiece. Due to the conditions of crystal growth, the c-axis of a 4H SiC crystal is typically deviated from the normal of the surface of the workpiece by 4° + / - 1°, and the direction of such tilt is not always obvious. The magnitude and direction of the tilt can also vary from workpiece to workpiece and from point to point on the workpiece. For this reason, the processing results can be different when the ion beam enters and exits the channeling condition.

[0007] Therefore, it would be beneficial to have an ion implanter and a method for implanting ions into a workpiece that can determine and monitor the crystalline orientation of the workpiece prior to performing an ion implantation treatment to facilitate guiding the ion beam into the workpiece. Summary of the Invention

[0008] According to one embodiment, an ion implanter is disclosed. The ion implanter includes: an ion source for generating an ion beam; a platen for supporting a workpiece having a crystalline structure; an X-ray source for generating an X-ray beam, wherein at least a portion of the X-ray beam impinges on the workpiece to generate diffracted X-rays; an X-ray detector positioned to receive the diffracted X-rays; and a controller in communication with the X-ray source, the platen, and the X-ray detector. The controller includes a memory device containing instructions that, when executed by the controller, enable the ion implanter to perform the following operations: perform a rocking curve test after the workpiece is placed on the platen; and calculate the orientation of the platen for an ion implantation process based on the results of the rocking curve test to facilitate guiding the ion beam into the crystalline structure of the workpiece. In certain embodiments, the memory device further contains instructions that, when executed by the controller, enable the ion implanter to perform the following operation: perform an ion implantation process while the workpiece is placed on the platen in the calculated orientation. In some embodiments, the rocking curve test is performed while the platen is placed in a loading position, wherein the clamping surface of the platen is horizontal in the loading position. In some embodiments, the rocking curve test is performed at multiple locations on the workpiece. In certain embodiments, the workpiece is rotated about an axis passing through the center of the platen and perpendicular to the clamping surface of the platen such that the X-ray beam impinges on a new location on the workpiece. In certain embodiments, the ion beam has a width in the X direction and a height in the Y direction, and the platen is translated in the Y direction such that the X-ray beam impinges on a new location on the workpiece. In some embodiments, the platen is adapted to tilt about the X axis and the Y axis, wherein the X axis passes through the center of the platen and is parallel to the width of the ion beam, and the Y axis passes through the center of the platen and is parallel to the height of the ion beam, and wherein the rocking curve test is performed while the platen is tilted about the X axis to determine the X tilt angle with the maximum intensity and is performed while the platen is tilted about the Y axis to determine the Y tilt angle with the maximum intensity, and wherein the controller calculates the orientation to be used for the ion implantation process based on the X tilt angle and the Y tilt angle determined during the rocking curve test. In certain embodiments, the X-ray detector is a two-dimensional sensor array such that the estimated X tilt angle and the estimated Y tilt angle are determined without tilting the workpiece, and the rocking curve test is performed by tilting about the estimated X tilt angle and the estimated Y tilt angle. In some embodiments, the ion implanter includes a collimator positioned to receive the X-ray beam from the X-ray source and collimate the X-ray beam to provide the portion of the X-ray beam to the workpiece. In some embodiments, the platen, the X-ray source, and the X-ray detector are disposed in a processing chamber configured to receive the ion beam. In certain embodiments, the X-ray source and the X-ray detector are disposed on a top portion of the processing chamber.In some embodiments, a platen is disposed in a processing chamber configured to receive an ion beam, and at least one of an X-ray source and an X-ray detector is disposed outside the processing chamber, and a window is provided in the processing chamber to enable X-rays to pass between the processing chamber and the environment outside the processing chamber. In some embodiments, the X-ray source and the X-ray detector are movable to adjust the angle at which the X-ray beam impinges on the workpiece.

[0009] According to another embodiment, an ion implanter is disclosed. The ion implanter includes: an ion source for generating an ion beam; a processing chamber into which the ion beam enters and a platen is disposed in the processing chamber; an auxiliary chamber disposed adjacent to the processing chamber, the auxiliary chamber comprising: an auxiliary platen adapted to support a workpiece having a crystalline structure; an X-ray source for generating an X-ray beam, wherein at least a portion of the X-ray beam impinges on the workpiece to generate diffracted X-rays; an X-ray detector positioned to receive the diffracted X-rays; a workpiece handling robot for transferring the workpiece from the auxiliary chamber to the processing chamber; and a controller in communication with the X-ray source, the auxiliary platen, the X-ray detector, the platen, and the workpiece handling robot, wherein the controller includes a memory device that contains instructions which, when executed by the controller, enable the ion implanter to perform the following operations: perform a rocking curve test after the workpiece is disposed on the auxiliary platen; calculate an orientation of the workpiece for an ion implantation process based on the results of the rocking curve test to facilitate guiding the ion beam into the crystalline structure of the workpiece; and transfer the workpiece to the platen in the processing chamber using the workpiece handling robot. In some embodiments, the ion implanter includes a second X-ray source and a second X-ray detector, wherein the memory device further contains instructions which, when executed by the controller, enable the ion implanter to perform the following operation: perform a second rocking curve test in the processing chamber using the second X-ray source and the second X-ray detector after the workpiece has been transferred to the processing chamber. In certain embodiments, the second X-ray source and the second X-ray detector are disposed in the processing chamber. In certain embodiments, the platen includes a heater, and the memory device further contains instructions which, when executed by the controller, enable the ion implanter to perform the following operations: heat the platen after the workpiece is transferred to the processing chamber; and perform a second rocking curve test in the processing chamber using the second X-ray source and the second X-ray detector after the workpiece has reached a desired temperature. In certain embodiments, the second X-ray source and the second X-ray detector are disposed in the processing chamber. In some embodiments, the X-ray detector includes a two-dimensional sensor array such that an estimated X tilt angle and an estimated Y tilt angle are determined during the rocking curve test, and wherein the second rocking curve test is performed in the processing chamber by tilting the platen about the estimated X tilt angle and the estimated Y tilt angle. In some embodiments, the memory device further contains instructions which, when executed by the controller, enable the ion implanter to perform the following operation: perform an ion implantation process while the workpiece is disposed on the platen in the calculated orientation.

[0010] According to another embodiment, a system is disclosed. The system includes: an ion implanter including an ion source for generating an ion beam; a processing chamber including a platen for supporting a workpiece having a crystalline structure; an equipment front end module (EFEM) in communication with the processing chamber via a load lock; an XRD station for performing a rocking curve test and determining orientation information of the workpiece based on the results of the rocking curve test to facilitate guiding the ion beam into the crystalline structure of the workpiece; a reader associated with the XRD station for detecting an identifier, wherein the identifier is used to create a unique workpiece identifier; and a central controller in communication with the reader and the XRD station to associate the orientation information from the XRD station with the unique workpiece identifier.

[0011] In some embodiments, the XRD station is located within the EFEM. In certain embodiments, the workpiece is disposed in a cassette, the cassette includes a cassette number as an identifier, and the combination of the cassette number and a slot number is used to create a unique workpiece identifier, the reader determines the cassette number based on an RFID tag on the cassette, and after receiving the cassette number from the reader, the central controller determines whether an XRD test has been performed on the workpiece in the cassette. In certain embodiments, an atmospheric robot is provided in the EFEM, and if an XRD test has been performed on the workpiece in the cassette, the central controller instructs the atmospheric robot to directly transfer the workpiece to the load lock. In certain embodiments, if an XRD test has not been performed on the workpiece, the central controller instructs the atmospheric robot to transfer the cassette to the XRD station. In certain embodiments, the reader determines the unique workpiece identifier, and after receiving the unique workpiece identifier from the reader, the central controller determines whether an XRD test has been performed on the workpiece. In certain embodiments, an atmospheric robot is provided in the EFEM, and if an XRD test has been performed on the workpiece, the central controller instructs the atmospheric robot to directly transfer the workpiece to the load lock. In certain embodiments, if an XRD test has not been performed on the workpiece, the central controller instructs the atmospheric robot to transfer the workpiece to the XRD station.

[0012] In some embodiments, the central controller controls the platen directly or indirectly based on the orientation information associated with the unique workpiece identifier.

[0013] In some embodiments, the XRD station is located outside the ion implanter, the EFEM, and the processing chamber. In certain embodiments, an additional reader is provided in the EFEM or in the processing chamber. In certain embodiments, after performing the rocking curve test, the workpiece is transferred from the XRD station to the EFEM, and the unique workpiece identifier is detected by the additional reader located in the EFEM or in the processing chamber, and the unique workpiece identifier is transmitted to the central controller. In certain embodiments, if the central controller determines that the XRD process has been performed on the workpiece, the central controller controls the platen directly or indirectly based on the orientation information associated with the unique workpiece identifier. In certain embodiments, if the central controller determines that the XRD process has not been performed on the workpiece, the central controller reports an error. In certain embodiments, the workpiece is disposed in a cassette and the reader detects the cassette number, and the cassette number is combined with the slot number to create a unique workpiece identifier, and after performing the rocking curve test on the workpiece in the cassette, the cassette is transferred from the XRD station to the EFEM, and the unique workpiece identifier is detected by the additional reader located in the EFEM or in the processing chamber, and the unique workpiece identifier is transmitted to the central controller. In certain embodiments, a second XRD station is located outside the EFEM and the processing chamber; a second reader is associated with the second XRD station to determine the unique workpiece identifier; and the central controller communicates with the second reader and the second XRD station to receive the unique workpiece identifier and associate the orientation information with the unique workpiece identifier.

[0014] According to another embodiment, a system is disclosed. The system includes: an ion implanter including an ion source for generating an ion beam; a processing chamber including a platen for supporting a workpiece having a crystalline structure; an equipment front end module (EFEM) in communication with the processing chamber via a load lock; an XRD station for performing a rocking curve test and determining orientation information of the workpiece based on the results of the rocking curve test to facilitate guiding the ion beam into the crystalline structure of the workpiece, wherein the XRD station is not located in the EFEM or the processing chamber; and a controller in communication with the XRD station to receive the orientation information from the XRD station and control the platen directly or indirectly based on the orientation information. In some embodiments, a second controller is dedicated to the ion implanter, and the controller forwards the orientation information to the second controller to control the platen. In some embodiments, a second XRD station is located outside the EFEM and the processing chamber; and the controller communicates with the second XRD station to receive the orientation information from the second XRD station.

[0015] According to another embodiment, a system is disclosed. The system includes: an ion implanter including an ion source for generating an ion beam; a processing chamber including a platen for supporting a workpiece having a crystalline structure; a reader; and a controller in communication with the reader, wherein the controller includes a table or other data structure associating unique workpiece identifiers with orientation information, and wherein the controller receives a unique workpiece identifier from the reader, associates the orientation information with the unique workpiece identifier, and controls the platen directly or indirectly based on the orientation information. In some embodiments, the system includes a second controller dedicated to the ion implanter, wherein the controller forwards the orientation information to the second controller to control the platen. In some embodiments, the system includes an equipment front end module (EFEM) in communication with the processing chamber via a load lock; and the reader is disposed in the EFEM or the processing chamber BRIEF DESCRIPTION OF THE DRAWINGS

[0016] To better understand the present disclosure, reference is made to the accompanying drawings, which are incorporated herein by reference and in which:

[0017] Figure 1 An ion implanter according to one embodiment is shown.

[0018] Figure 2A A configuration of an X-ray source and an X-ray detector in a processing chamber is shown.

[0019] Figure 2B Another configuration of an X-ray source and an X-ray detector in a processing chamber is shown.

[0020] Figure 2C A third configuration of an X-ray source and an X-ray detector in a processing chamber is shown.

[0021] Figure 2D A configuration of an X-ray source and an X-ray detector outside the processing chamber is shown.

[0022] Figure 3 Rotation and tilt of a workpiece on a platen are shown.

[0023] Figure 4 An X-ray source and a collimator according to one embodiment are shown.

[0024] Figure 5 Shows a sequence that can be used for processing a workpiece using Figure 1 the ion implanter shown.

[0025] Figure 6 Shows a sequence that can be used Figure 1 to perform a rocking curve test using the ion implanter shown.

[0026] Figure 7Shows an ion implanter according to another embodiment.

[0027] Figure 8 Shows a sequence that can be used to process a workpiece using Figure 7 the ion implanter shown.

[0028] Figure 9 Shows the configuration of an XRD station according to one embodiment.

[0029] Figure 10 Shows a system having an XRD station disposed in an EFEM.

[0030] Figure 11 Shows a sequence for identifying a workpiece and then orienting a platen using Figure 10 the configuration shown.

[0031] Figure 12 Shows a system according to one embodiment, having one or more XRD stations disposed outside an ion implanter, an EFEM, and a processing chamber.

[0032] Figure 13 Shows a sequence for identifying a workpiece and then orienting a platen using Figure 12 the configuration shown.

[0033] Figure 14 Shows a system according to another embodiment, having one or more XRD stations disposed outside an ion implanter, an EFEM, and a processing chamber. Detailed Description

[0034] As previously mentioned, in some cases, it can be beneficial to perform channeled implants. The term "channeled implant" refers to an implant that is performed such that ions are implanted along channels of the crystalline structure of a workpiece (e.g., a SiC wafer). However, it can be difficult to properly orient the workpiece such that the incoming ion beam is aligned with the channels. The accuracy of such alignment depends on several parameters, but most significantly on the energy of the ions. Effective channeling uses a maximum angular deviation that decreases with increasing energy. The critical angle for channeling is given by the following equation

[0035]

[0036] where ψ is the critical angle, U(r crit ) is the potential energy of the channel walls determined by the lattice, and E is the kinetic energy of the ions. For high-energy implants of several million electron volts, the angular acceptance of the channels can be as small as 0.05°, while at a few thousand electron volts it can be several degrees.

[0037] Figure 1 Shows a first embodiment of an ion implanter 1 capable of performing angular alignment and verification using XRD before implantation.

[0038] In some embodiments, the ion implanter 1 can be a high-energy ion implanter or a medium-current beamline ion implanter capable of generating an implantation energy of 1 million electron volts or greater than 1 million electron volts. In other embodiments, the implantation energy generated by the ion implanter 1 can be less than 1 million electron volts. The ion implanter 1 includes an ion source 200 for generating an extracted ion beam 201. In one embodiment, the ion source 200 can be a Bernas ion source or an indirectly heated cathode (IHC) ion source. Of course, other types of ion sources can also be used. A feedgas is supplied to the ion source 200, and then the ion source 200 is charged to generate ions. Then, an extraction optical device (not shown) is used to extract these ions from the ion source 200 and form the extracted ion beam 201.

[0039] The extracted ion beam 201 can be directed towards a mass analyzer 205 that only allows certain types of ions to pass through. The ions leaving the mass analyzer 205 are directed towards an accelerator assembly 210. The accelerator assembly 210 is used to accelerate the ions entering the assembly from a lower energy to a higher energy. The accelerator assembly 210 can have different configurations.

[0040] In one embodiment, the accelerator assembly 210 can be an acceleration column that includes a plurality of bias electrodes for accelerating the ion beam. As the ions pass through the column, more negative bias can be applied to the electrodes, thereby accelerating the positive ions.

[0041] In another embodiment, the accelerator assembly 210 can be a tandem accelerator. In this embodiment, negative ions can be admitted into the first accelerator column and accelerated to a first energy, and then the electrons of the negative ions are stripped to form positive ions and are accelerated to a final higher energy by the second accelerator column.

[0042] In another embodiment, the accelerator assembly 210 can be a linear accelerator (LINAC). In this embodiment, a separate buncher can admit the ion beam from the ion source 200 and generate a bunched pulse ion beam. A series of resonators or accelerators can be excited by their respective radio frequency (RF) signals to increase the speed of the incoming pulse beam to a desired high energy level.

[0043] In all such embodiments, after leaving the accelerator assembly 210, the spot ion beam 211 can enter the scanner 215. The scanner 215 spreads the spot ion beam 211 into a plurality of divergent ion sub-beams. In other words, the scanner 215 forms a divergent ion trajectory path. The scanner 215 can be electrostatic or magnetic. By using the scanner 215, the ion beam becomes wider. The direction in which the scanner 215 moves the beam can be referred to as the X direction. It should be noted that after leaving the scanner 215, the ion beam is wider compared to its height.

[0044] The angle corrector 220 is designed to deflect the ions in the scanned ion beam to generate an ion beam 230 having parallel ion trajectories, thereby focusing the scanned ion beam. Specifically, the angle corrector 220 is used to change the divergent ion trajectory path into a substantially parallel path of the ion beam 230. In some embodiments, the angle corrector 220 can include magnetic pole pieces spaced apart to define a gap and a magnet coil coupled to a power source. The scanned ion beam passes through the gap between the magnetic pole pieces and is deflected according to the magnetic field in the gap. In other embodiments, the angle corrector 220 can be an electrostatic lens, sometimes referred to as a parallelization lens.

[0045] Of course, the ion implanter can include other components, such as quadrupole lenses, additional electrodes for accelerating or decelerating the ion beam, and other elements.

[0046] The ion beam 230 enters the processing chamber 100. Figure 1 A top view of the ion implanter 1 is shown such that the height of the ion beam 230 is perpendicular to the plane of the drawing. A Cartesian Coordinate System can be defined to assist in the explanation, where the Z direction is defined by the path of the ion beam 230. As Figure 1 shown, the ion beam 230 has a height in the Y direction and a width in the X direction.

[0047] As Figure 1 shown, the ion beam 230 enters the processing chamber 100, in which the workpiece to be implanted is disposed. The workpiece 10 is disposed on the clamping surface 169 of the platen 160. The platen 160 may be capable of moving and rotating in several directions. In Figure 1 , the platen 160 is in the operating position or implantation position, where the clamping surface 169 of the platen 160 is substantially perpendicular to the ion beam 230. This is the orientation of the platen 160 during ion implantation. In this embodiment, the X-ray source 110 and the X-ray detector 130 are disposed on either side of the platen 160 in the X direction or the width direction.

[0048] In Figure 2A Figure 4 shows a perspective view of the processing chamber 100, where the X-ray source 110 and the X-ray detector 130 are positioned in the processing chamber 100 and are disposed on either side of the platen 160 in the X direction.

[0049] However, there may also be other embodiments. Figure 2B Figure 5 shows a perspective view of the processing chamber 100 according to another embodiment. In this embodiment, the X-ray source 110 and the X-ray detector 130 are positioned in the processing chamber 100 and are disposed on either side of the platen 160 in the Y direction or the height direction.

[0050] The workpiece 10 can be moved in one or more dimensions by the platen 160. For example, the platen 160 can be moved in the Y direction (corresponding to the height of the ion beam 230) such that after the platen 160 has moved through the ion beam 230, the entire workpiece 10 is exposed to the ion beam 230. The platen 160 is also capable of tilting and rotating about several axes.

[0051] Figure 3 Figure 6 shows the platen 160 and various rotational directions of the platen 160. Figure 3 Figure 7 shows a perspective view of the platen 160, which is capable of rotating and is referred to as a roplat. The platen 160 can have three axes. There can be a twist axis 161, which is perpendicular to the clamping surface 169 of the platen 160 and passes through the center of the platen 160. The rotation about this twist axis 161 is referred to as the twist angle 162. There is an X axis 163, which passes through the center of the platen, is parallel to the clamping surface 169 of the platen 160, and is perpendicular to the twist axis 161. The X axis 163 is parallel to the wide dimension of the ion beam 230. The tilt about the X axis 163 is referred to as the X tilt angle 164. There is also a Y axis 165, which also passes through the center of the platen 160, is parallel to the clamping surface 169 of the platen 160, and is perpendicular to the twist axis 161 and the X axis 163. The tilt about the Y axis 165 is referred to as the Y tilt angle 166.

[0052] The X-ray source 110 and the X-ray detector 130 are also disposed in the processing chamber 100. As Figure 4As shown, a collimator 115 can also be used to receive an X-ray beam from the X-ray source 110 to provide collimation of the X-rays and form the emitted X-ray beam 120. In some embodiments, the X-ray source 110 can be a filtered Cu target X-ray source known in the art or any other suitable X-ray source. The collimator 115 can be used to generate a tightly parallel beam that can be directed towards a specific region of the workpiece 10. In some embodiments, the collimator 115 includes one or more slits. In other embodiments, the collimator 115 includes one or more crystals, such as germanium crystals or silicon crystals. In one embodiment, as Figure 4 shown, the X-ray beam from the X-ray source 110 enters the germanium crystal 118 through one face and is reflected off two inner faces along the (220) direction before leaving the crystal as the emitted X-ray beam 120. This can be referred to as a Ge(220)-2 bounce collimator or monochromator. In another embodiment, two crystals are arranged such that when the X-rays leave the first germanium crystal, they enter the second germanium crystal and are again reflected off two inner faces along the (220) direction before leaving as the emitted X-ray beam 120. This can be referred to as a Ge(220)-4 bounce collimator or monochromator. In another embodiment, the crystals can be arranged such that the X-ray beam from the X-ray source 110 enters one face and is reflected off two inner faces along the (440) direction. Then the X-rays leave the first germanium crystal and enter the second germanium crystal, where the X-rays are again reflected off two inner faces in the (440) direction before leaving as the emitted X-ray beam 120. This can be referred to as a Ge(440)-4 bounce collimator or monochromator. Of course, other collimators can also be used. When using crystals, only X-ray beams with the desired trajectory can pass through the crystals and reach the workpiece 10. In each of these embodiments, the X-ray source 110 generates an X-ray beam, at least a portion of which ultimately strikes the workpiece 10 as the emitted X-ray beam 120.

[0053] The X-ray detector 130 measures the diffracted X-rays 125 from the workpiece and can be used to plot the measured amount (also referred to as intensity) of the diffracted X-rays 125 as a function of the X tilt angle and the Y tilt angle, as Figure 1 shown in the graph 135 of. The X-ray detector 130 is well known and will not be described further herein. In some embodiments, the X-ray source 110, the workpiece 10, and the X-ray detector 130 are arranged to achieve the Bragg scattering angle given by the Bragg equation:

[0054] λ = 2dsinθ

[0055] where λ is the wavelength of the X-rays (for Cu Kα For the ray, it is 0.1541 nanometers), and d is the spacing of the crystal plane; given In the case of 4H SiC in the (0001) direction, the selection rule enables the (0004) plane to give a spacing of c / 4 = 0.251 nanometers.

[0056] For X-ray beams of different wavelengths or workpieces of different materials, the X-ray source 110 and the X-ray detector 130 can be positioned at different angles. It should be noted that both the X-ray source 110 and the X-ray detector 130 are positioned at the same angle relative to the workpiece 10.

[0057] In another embodiment, the X-ray source and the X-ray detector are mounted on an articulated arm such that the X-ray source and the X-ray detector can be used for different diffraction angles corresponding to different lattice spacings.

[0058] In another embodiment, the X-ray detector 130 can be a one-dimensional sensor array or a two-dimensional sensor array, which can be used to enable the detection of the X-ray diffraction angle range. In these embodiments, the X-ray detector 130 includes a plurality of sensors, and each sensor is adapted to detect X-rays. Such a one-dimensional X-ray detector or two-dimensional X-ray detector can be referred to as an extended X-ray detector. In this way, such an extended X-ray detector can simultaneously provide information about multiple angles instead of only receiving information about a single angle.

[0059] The ion implanter 1 is also controlled using a controller 280. The controller 280 has a processing unit 281 and an associated memory device 282. Such a memory device 282 contains instructions 283 that, when executed by the processing unit 281, enable the system to perform the functions described herein. The controller 280 is capable of controlling the twist angle 162, the X tilt angle 164, and the Y tilt angle 166 of the platen 160. The controller 280 also communicates with components of the ion implanter 1, including the X-ray source 110 and the X-ray detector 130. Such a memory device 282 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 282 can be volatile memory such as random access memory (RAM) or dynamic random access memory (DRAM). In certain embodiments, the controller 280 can be a general-purpose computer, an embedded processor, or a specially designed microcontroller. The actual implementation of the controller 280 is not limited by this disclosure.

[0060] Having described one configuration of the ion implanter 1, the operation of the system will be described.

[0061] In Figure 5 an operation mode is shown. As Figure 5 shown in block 500 of

[0062] Then the controller 280 can store the X tilt angle and the Y tilt angle that form the peak intensity, as shown in block 520. Based on this information, the controller 280 can determine the crystal orientation of the workpiece 10 and thus determine the proper orientation of the workpiece 10 during subsequent implantation, as shown in block 530. For example, SiC can be used for a variety of different polytypes, including 2H, 4H, 6H, 15R, and 3C. Each polytype can utilize a different set of optimal tilt angles. By performing a rocking curve test, the controller 280 can identify the polytype and can also identify the exact orientation of the workpiece. Once the X tilt angle and the Y tilt angle are calculated, the calculated angles can be used during the ion implantation process, as shown in block 540.

[0063] In Figure 2A the embodiment shown, when the ion beam 230 is exactly in the Z direction and the X-ray source 110 and the X-ray detector 130 are angularly symmetric about the Z direction, the optimal guidance will be at the workpiece angle that maximizes the X-ray diffraction intensity. Several possible events can modify this simple algorithm. For example, if an accurate measurement of the ion beam 230 shows that it is slightly angled with respect to the Z axis, or if the X-ray source 110 or the X-ray detector 130 is offset from its ideal position due to mechanical tolerances, then these displacements need to be accounted for by offsetting the implantation angle with respect to the angle of maximum diffraction intensity.

[0064] By determining the X tilt angle and the Y tilt angle that maximize the intensity of the X-ray emission, the controller 280 can identify the suitable orientation of the platen 160 to be used for the implantation process to facilitate guidance. Specifically, in some embodiments, it may be desirable to perform the implantation while the workpiece is oriented on the platen 160 such that the implantation is a guided implantation. This allows the implanted ions to be implanted deeper (for a given energy) and also causes less damage to the workpiece. In some embodiments, the X tilt angle and the Y tilt angle are selected to maximize the guidance.

[0065] Figure 6Shows a sequence that can be used to perform a rocking curve test. First, as shown in block 600, the X-ray source 110 and the X-ray detector 130 are enabled. Then the controller 280 varies the X tilt angle 164 of the platen 160 while directing the emitted X-ray beam 120 at the workpiece 10, as shown in block 610. The range of X tilt angles used during the rocking curve test can vary. For example, in some embodiments, the workpiece can be tilted ±5°. In other embodiments, the angle range can be smaller, such as ±1° or ±2°. In still other embodiments, the angle range can be greater than 5°. The intensity of the diffracted X-rays 125 is recorded using the X-ray detector 130, and the controller 280 stores the recorded intensities as a function of the X tilt angle, as shown in block 620. The result of such a process can be Figure 1 the graph 135 shown in or can be a numerical table. Then the controller 280 varies the Y tilt angle 166 of the platen 160 while directing the emitted X-ray beam 120 at the workpiece 10, as shown in block 630. In some embodiments, the X tilt angle is set to the X tilt angle that exhibits the maximum intensity. Similarly, as described above, the range of Y tilt angles used during the rocking curve test can vary. The intensity of the diffracted X-rays 125 is recorded using the X-ray detector 130, and the controller 280 stores the recorded intensities as a function of the Y tilt angle, as shown in block 640. The result of such a process can be Figure 1 the second graph 135 shown in or can be one or more tables, each of which includes values of tilt angles and corresponding intensity values. Once this operation is complete, the controller 280 can disable the X-ray source 110 and the X-ray detector 130. It should be noted that in some embodiments, the rocking curve test is performed for only one tilt angle. For example, in some embodiments, blocks 610 to 620 or blocks 630 to 640 can be omitted.

[0066] In still other embodiments, if an extended X-ray detector is used, the changes in the X tilt angle and the Y tilt angle can be smaller. For example, a two-dimensional X-ray detector can enable the controller 280 to determine the X tilt angle and the Y tilt angle that exhibit the highest intensity without rotating the workpiece. In another embodiment in which an extended X-ray detector is used, the initial output from the extended X-ray detector is used to set the estimated X tilt angle and the estimated Y tilt angle, and then a rocking curve test is performed, causing the platen to tilt about those estimated angles. For example, an initial scan can indicate that the maximum intensity is detected at tilt angles X1 and Y1. Then the rocking curve test can be performed using, for example, an X tilt angle of X1 ± 1° and a Y tilt angle of Y1 ± 1°.

[0067] In some embodiments, it may be beneficial to perform rocking curve tests at multiple locations on the workpiece. This can be achieved in a variety of ways. In one embodiment, the platen 160 can be moved in the Y direction such that the emitted X-ray beam 120 can strike different locations on the workpiece. In another embodiment, the platen 160 can be rotated about the torsion axis 161 such that the emitted X-ray beam 120 can strike different locations on the workpiece. In another embodiment, the platen 160 is moved in the Y direction and rotated about the torsion axis 161. In each of these embodiments, once the workpiece 10 has been moved or rotated, the sequence shown in Figure 6 can be repeated. In some embodiments, the results from the multiple rocking curve tests can be averaged to determine the appropriate X tilt angle and Y tilt angle for the implantation process. In other embodiments, the X tilt angle and Y tilt angle can vary as a function of the position of the platen 160 in the Y direction. For example, if the X tilt angle and / or Y tilt angle vary along the Y direction, the tilt of the platen 160 can be varied as the ion beam 230 scans the workpiece 10. If the X tilt angle and / or Y tilt angle vary along the X axis, the angle corrector 220 can be adjusted to generate a converging or diverging ion beam to address the Y tilt variation, while the rotation of the scan plate can be adjusted to generate a distortion of the trajectory to address the X tilt variation.

[0068] In some embodiments, the platen 160 can also heat the workpiece 10 to an elevated temperature, such as greater than 350 °C. In some embodiments, the elevated temperature can be 500 °C or greater than 500 °C. In these embodiments, the rocking curve test can be started only after the workpiece 10 reaches the desired temperature.

[0069] In other embodiments, the rocking curve test can be performed before the workpiece is heated and then again after the workpiece is heated. In this way, any change in the rocking curve test results can potentially be the result of thermal warping or deformation of the workpiece. This can be compensated for by additional clamping forces (electrostatic clamping force or mechanical clamping force). As an alternative, the orientation of the platen 160 can be adjusted to achieve an optimal compromise of the workpiece shape at the implantation temperature.

[0070] Although Figure 1 and Figure 2A-2B show the rocking curve test being performed while the platen 160 is in the operating position, there can be other embodiments. Figure 2CA perspective view of a processing chamber 100 is shown. In this embodiment, the platen 160 is set in the loading position, where the clamping surface of the platen 160 is horizontal. In this embodiment, the X-ray source 110 and the X-ray detector 130 are disposed inside the processing chamber 100 and near the top portion of the processing chamber 100. The area near the top portion of the processing chamber 100 may have fewer contaminants compared to other areas. In this embodiment, the X tilt angle is set to 90° to place the platen 160 in the loading position. Then, the X tilt angle changes around this tilt angle. In other words, although Figure 1 and Figure 2A-2B the illustrated embodiment changes the X tilt angle by approximately 0°, however Figure 2C the illustrated embodiment changes the X tilt angle by approximately 90°.

[0071] In yet another embodiment, at least one of the X-ray source 110 or the X-ray detector 130 may be disposed outside the processing chamber 100, as Figure 2D shown. For example, a window may be provided in the wall of the processing chamber 100 such that X-rays can pass through the window. In one embodiment, both the X-ray source 110 and the X-ray detector 130 are disposed outside the processing chamber 100. In this embodiment, the X-rays leaving the X-ray source 110 pass through the first window and enter the processing chamber 100, and the X-rays strike the workpiece 10 in the processing chamber 100. Then the diffracted X-rays pass through the second window to reach the X-ray detector 130. In some embodiments, the window may be a thin polymer film, a diamond-like carbon window, or a beryllium window. The X-ray source 110 and / or the X-ray detector 130 may be positioned as Figure 2D shown or may be positioned above the top surface of the processing chamber 100.

[0072] In certain embodiments, the rocking curve test may be performed in a chamber different from the processing chamber. One such embodiment is shown in Figure 7 . The ion implanter 1 may include an ion source 200, a mass analyzer 205, an accelerator assembly 210, a scanner 215, and an angle corrector 220, but is not shown.

[0073] In this embodiment, the X-ray source 110 and the X-ray detector 130 are disposed in the auxiliary chamber 300. An auxiliary platen 310 is also disposed in the auxiliary chamber 300. This auxiliary platen 310 may be similar to the above-mentioned platen 160 in that it can rotate about one or more axes.

[0074] In this way, a rocking curve test can be performed in the auxiliary chamber 300. Since the processing chamber 100 is not used for the rocking curve test, this enables a higher throughput to be achieved. Thus, in this embodiment, the rocking curve test is performed in the auxiliary chamber 300, and the workpiece transfer robot 320 is used to move the workpiece to the processing chamber 100. The rocking curve test can be performed while the clamping surface of the auxiliary platen 310 is vertical, as shown in Figure 7 as shown. In other embodiments, similar to the embodiment shown in Figure 2C as shown, the rocking curve test can be performed while the clamping surface of the auxiliary platen 310 is horizontal. A sequence is shown in Figure 8 which shows the operations associated with this embodiment.

[0075] As shown in block 800, the workpiece is placed on the clamping surface of the auxiliary platen 310 in the auxiliary chamber 300. Identification of the workpiece is performed. In block 810, the controller 280 then performs a rocking curve test, as elaborated for Figure 6 As shown in block 820, the controller 280 stores the X tilt angle and the Y tilt angle at which the detected intensity is at a peak. As shown in block 830, these tilt angles can then be used to calculate the orientation to be used during a subsequent ion implantation process. As shown in block 840, the controller 280 then stores the identity of the workpiece and the orientation associated with the workpiece. As shown in block 850, the controller 280 then uses the workpiece transfer robot 320 to move the workpiece to the processing chamber 100 while maintaining the orientation of the workpiece. As shown in block 860, once in the processing chamber 100, the controller 280 identifies the workpiece and then performs an ion implantation process using the calculated orientation associated with the workpiece (i.e., the X tilt angle and the Y tilt angle). This method minimizes the time the workpiece stays in the processing chamber 100, thereby increasing the throughput.

[0076] In some embodiments, the controller may store the X tilt angle and the Y tilt angle from block 830 and not calculate the orientation to be used in the implantation process until later.

[0077] In yet another embodiment, the X-ray source 110 and the X-ray detector 130 can be replicated such that there are X-ray sources 110 in the auxiliary chamber 300 and the processing chamber 100. Similarly, there can be X-ray detectors 130 in the auxiliary chamber 300 and the processing chamber 100. In this embodiment, the rocking curve test can be performed in the auxiliary chamber 300. After the workpiece is moved to the processing chamber 100, the workpiece can be heated. The temperature change can affect the orientation for the ion implantation process. Therefore, after heating, the second rocking curve test can be repeated. However, since the preliminary rocking curve test has been performed in the auxiliary chamber 300, the angular range used in the second rocking curve test can be smaller, thereby enabling the test to be completed more quickly.

[0078] In one embodiment, an extended X-ray detector can be disposed in the auxiliary chamber 300, and the estimated X tilt angle and the estimated Y tilt angle can be determined without tilting the workpiece. Then these estimated X tilt angles and estimated Y tilt angles are used as the center for the rocking curve test performed in the processing chamber 100.

[0079] The components in the auxiliary chamber 300 can form part of an XRD station. In some embodiments, for example Figure 9 as shown in, the XRD station 350 includes: an X-ray source 110 for generating an emitted X-ray beam 120; an X-ray detector 130 for receiving the diffracted X-rays 125; and an auxiliary platen 310. The XRD station 350 also includes an XRD controller 330 that is configured to perform the rocking curve test and store the results. This XRD controller 330 is configured to perform the rocking curve test, such as Figure 6 the rocking curve test shown in. The XRD controller 330 communicates with the auxiliary platen 310, the X-ray source 110, and the X-ray detector 130 to perform the rocking curve test. Additionally, the XRD controller 330 can also include a network interface that enables the XRD controller 330 to communicate with other devices such as a central controller (which can be the controller 280 or a different controller).

[0080] In addition to the configurations already discussed, this XRD station 350 can be disposed in other locations within the system. Figure 10 A first configuration is shown, in which the XRD station 350 is located in or near an Equipment Front End Module (EFEM). Figure 10 An ion implanter 900 is shown, and the ion implanter 900 can include many of the components described for Figure 1 The ion implanter 900 can include Figure 1The ion source 200, mass analyzer 205, accelerator assembly 210, scanner 215, and angle corrector 220 shown in [Figure 0]. The system also includes a processing chamber 100, and a platen 160 is disposed in the processing chamber 100. An ion beam generated by an ion implanter 900 is guided to the processing chamber 100. A workpiece is loaded into the processing chamber 100 through a load station (also referred to as an EFEM 910). The EFEM 910 includes one or more transfer stations 911 that transfer the workpiece from the external environment into the EFEM 910. These transfer stations 911 can receive a cassette including a plurality of workpieces, and each of the plurality of workpieces is disposed in a corresponding slot. One or more load locks 920 separate the EFEM 910 from the processing chamber 100. The EFEM 910 also includes one or more atmospheric robots 912 that are used to transfer the workpiece to be processed from the transfer station 911 to the load lock 920 and return the processed workpiece from the load lock 920 to the transfer station 911. An XRD station 350 is located inside or adjacent to the EFEM 910 such that the atmospheric robot 912 can access the XRD station 350. Additionally, a reader 913 can be provided in the EFEM 910. This reader 913 is used to detect a unique workpiece identifier (such as a serial number or other mark) to uniquely identify each workpiece. In some embodiments, the cassette includes an RFID tag. The reader 913 (which can be an RFID reader located within the transfer station 911) is capable of reading the RFID tag to uniquely identify the cassette. In some embodiments, this cassette identifier is combined with the slot number in which the workpiece is disposed to form a unique workpiece identifier. In other embodiments, the serial number is fixed to each workpiece by etching or other means. In this embodiment, the reader 913 can be an optical character recognition (OCR) reader, and the OCR reader can be used to read the serial number from the workpiece. Of course, the unique workpiece identifier can be created in other ways.

[0081] In addition, a central controller 930 can be used to monitor the transfer of the workpiece. This central controller 930 also tracks the results of the XRD process for each workpiece. In some embodiments, this central controller 930 also controls the ion implanter 900. However, in other embodiments, the controller 280 that controls the ion implanter 900 and the central controller 930 can be different components.

[0082] The central controller 930 can create a table or other data structure that includes a unique workpiece identifier (the unique workpiece identifier can be a combination of a cassette number and a slot number or a serial number) and the desired orientation of this workpiece as determined by the XRD station 350. This table or other data structure can be set in a memory device located within the central controller 930.

[0083] Using this unique workpiece identifier and the results from the XRD station 350, the central controller 930 can control the flow and processing of workpieces in the ion implanter 900. This sequence is as Figure 11 shown. First, the workpiece is placed in the transfer station 911. The workpiece can be set in a slot of a cassette. A reader 913 is used to detect the identifier (such as the unique workpiece identifier), as shown in block 1000. In some embodiments, this can be done by combining the cassette identifier and the slot number or by reading the serial number on the workpiece. This information is then forwarded to the central controller 930. The central controller 930 checks whether the orientation of this workpiece has been performed, as shown in block 1010. This can be done by comparing the unique workpiece identifier determined by the reader 913 with the table of workpieces that have been processed by the XRD station 350. If the central controller 930 determines that the workpiece has not been processed by the XRD station 350, the central controller 930 instructs the atmospheric robot 912 to move the workpiece to the XRD station 350, as shown in block 1020. In some embodiments, the entire cassette is moved to the XRD station 350. In other embodiments, the workpieces are transferred one by one. The XRD station 350 then performs a rocking curve test, and once the XRD process is complete, the XRD controller 330 forwards the orientation information to the central controller 930, and the central controller 930 associates the unique workpiece identifier with this orientation information. The atmospheric robot 912 then transfers the workpiece from the XRD station 350 to the load lock 920, as shown in block 1030. If the central controller 930 determines that the workpiece has been processed by the XRD station 350, the central controller 930 instructs the atmospheric robot to bypass the XRD station 350 and move the workpiece directly to the load lock 920, as shown in block 1030. Once the workpiece enters the processing chamber 100, the vacuum robot 101 moves the workpiece to the platen 160. The central controller 930 then extracts the orientation information associated with this workpiece from the table or other data structure and directly controls the platen 160 or forwards this orientation information to the controller 280, and then the controller 280 controls the platen 160, as shown in block 1040. Thereafter, the ion implanter 900 is enabled so that implantation can be performed.

[0084] In another embodiment, the cassette number is sufficient to perform Figure 11The sequence shown in. This embodiment assumes that all the workpieces in the cassette are processed in the same manner. Specifically, in block 1000, the reader 913 reads the RFID tag on the cassette and treats the RFID tag as an identifier. This identifier is then forwarded to the central controller 930. Then, in block 1010, the central controller 930 determines whether the XRD process has been performed on the workpieces contained in this cassette. If not, the entire cassette is transferred to the XRD station 350, as shown in block 1020. The XRD station 350 can then perform a rocking curve test on each workpiece, and once the XRD process is completed, the XRD controller 330 forwards the orientation information to the central controller 930, which associates the unique workpiece identifier (in the form of the cassette number and the slot number) with this orientation information and stores the information in a table or other data structure. In some embodiments, the XRD station 350 forwards both the cassette number and the slot number, while in other embodiments, since the central controller 930 has received the cassette number from the reader 913, only the slot number is forwarded. Once all the workpieces have been processed by the XRD station 350, the workpieces are transferred to the load lock 920 for implantation, as shown in block 1030. However, if the central controller 930 determines that the XRD process has been performed on the workpieces in this cassette, the atmospheric robot 912 transfers the workpieces directly to the load lock 920, as shown in block 1030.

[0085] Associating specific workpieces with their optimal orientations using the central controller 930 can be applied to other configurations. Figure 12 An embodiment is shown in which one or more XRD stations 350 are disposed outside the EFEM 910. In this embodiment, the XRD station 350 is disposed in an atmospheric environment.

[0086] The XRD reader 960 can be associated with each XRD station 350. Like the XRD station 350, these XRD readers 960 can communicate with the central controller 930. In some embodiments, the XRD reader 960 is part of the XRD station 350. In these embodiments, the XRD station 350 can also include a transfer station, similar to the transfer station in the EFEM 910. Specifically, in this embodiment, the XRD station 350 is capable of receiving a cassette of workpieces, reading the RFID tag on the cassette, and identifying the slots associated with each workpiece to generate a unique workpiece identifier. In another embodiment, the XRD reader 960 can be an OCR reader to detect the serial number on the workpiece. The XRD station 350 then performs the XRD process and relays the unique workpiece identifier and the associated orientation information to the central controller 930, which can store the information in a table or other data structure as described above.

[0087] In another embodiment, the XRD station 350 can accept one workpiece at a time. In these embodiments, the XRD reader 960 is located outside the XRD station 350. In one embodiment, the XRD reader 960 can accept a cassette, read an RFID tag, extract a workpiece from a slot in the cassette, generate a unique workpiece identifier, and transfer the workpiece to the XRD station 350. In another embodiment, the XRD reader 960 can detect the serial number on the workpiece and transfer the workpiece to the XRD station 350.

[0088] In some embodiments where the XRD station 350 is disposed outside the EFEM 910, the reader 913 can be located in the EFEM 910. This may be a case where the reader 913 includes an RFID reader or an OCR reader. In certain embodiments, if the reader 913 is an RFID reader, the reader 913 can be located within the transfer station 911. In other embodiments, the reader 913 can be disposed in the processing chamber 100. This may be a case where the reader 913 is an OCR reader that can be located at an aligner (not shown). In Figure 13The order that can be used for this embodiment is shown. First, a unique workpiece identifier is detected by one of the XRD readers 960, as shown in block 1300. In some embodiments, the unique workpiece identifier can be created based on the cassette number and the slot number. In other embodiments, the unique workpiece identifier can be directly set on each individual workpiece. The XRD station 350 then performs a rocking curve test and transmits the unique workpiece identifier and the associated orientation information to the central controller 930, as shown in block 1310. At some later time, the workpiece is then transferred to the transfer station 911, as shown in block 1320. In one embodiment, all the workpieces in the cassette are processed by the XRD station 350 and then the entire cassette is moved to the transfer station 911. This can be done by an operator or by using an automated robot. Note that this can occur immediately after the workpiece has been processed by the XRD station 350 or at a later time. The workpiece is then transferred into the EFEM 910, as shown in block 1330. The unique workpiece identifier of the workpiece is read and the workpiece is identified using the reader 913 in the EFEM 910 or the processing chamber 100, as shown in block 1340. The central controller 930 then checks to ensure that the XRD process has been performed on this workpiece. If so, the central controller 930 retrieves the orientation information associated with this workpiece from a table or other data structure and directly controls the platen 160 or forwards this orientation information to the controller 280, which then controls the platen 160, as shown in block 1350. Thereafter, the ion implanter 900 is enabled so that implantation can be performed. If the central controller 930 detects that the XRD process has not been performed on the workpiece, the central controller 930 can report an error, as shown in block 1360.

[0089] In such a configuration, the XRD station 350 can be remote from the ion implanter 900. As long as the XRD station 350 and the XRD reader 960 communicate with the central controller 930, the platen 160 in the ion implanter 900 can be properly oriented.

[0090] Note that in Figure 10-13 the embodiment shown, since the workpiece is only processed once by the XRD station 350, throughput can be increased. Thereafter, as long as the workpiece is to be processed by the ion implanter 900, the central controller 930 only uses the previously obtained orientation information.

[0091] In certain embodiments, there may not be any readers. In such a configuration, it is still possible to utilize the XRD station 350 disposed outside the EFEM 910. Such a configuration is as shown in Figure 14 In this embodiment, there can be one or more XRD stations 350. Each XRD station 350 communicates with the central controller 930.

[0092] In one embodiment, each XRD station 350 may include a transfer station similar to transfer station 911. In this way, an entire cassette filled with workpieces can be supplied to the XRD station 350. The XRD station 350 is capable of identifying each slot, removing a workpiece from this specific slot and performing a rocking curve test on this workpiece. Then, the XRD station 350 supplies the slot number and orientation information associated with the workpiece at this slot to the central controller 930, and the central controller 930 saves the information in a table or other data structure. The XRD station 350 repeats this process for all the workpieces in the cassette.

[0093] This process depends on introducing the cassettes into the EFEM 910 in the order in which the cassettes have been processed by the corresponding XRD station 350. Specifically, it is expected that the cassette that has been processed by the XRD station 350 earliest enters the EFEM 910 first. If there is only one XRD station 350, this can be easily implemented. Specifically, when a new cassette enters the ion implanter, the central controller 930 finds the orientation information that has not been associated with the cassette. The central controller 930 then assumes that this orientation information has just been generated by the XRD station 350 and is thus associated with the cassette that has entered the processing chamber 100. The central controller 930 then marks this orientation information as used. The central controller 930 then directly controls the platen 160 or forwards this orientation information to the controller 280, and then the controller 280 controls the platen 160. Thereafter, the ion implanter 900 is enabled so that implantation can be performed.

[0094] However, assume that there are two XRD stations 350. The first XRD station 350 in the XRD stations processes the first cassette, and then the second XRD station in the XRD stations processes the second cassette. Each XRD station transmits the orientation information associated with all the workpieces in this cassette to the central controller 930. In some embodiments, the orientation information may be accompanied by a time stamp or an indication of the test that has been performed by the XRD station. For example, each XRD station may have a unique IP address known to the central controller 930. When a new cassette enters the ion implanter, the central controller 930 finds the earliest orientation information that has not been associated with the cassette. The central controller 930 then assumes that this earliest orientation information is associated with the workpiece that has entered the processing chamber 100. The central controller 930 then marks this orientation information as used. The central controller 930 then directly controls the platen 160 or forwards this orientation information to the controller 280, and then the controller 280 controls the platen 160. Thereafter, the ion implanter 900 is enabled so that implantation can be performed.

[0095] As described above, in some embodiments, the central controller 930 is used to communicate with the XRD station 350 and communicate with a separate controller 280 that controls the ion implanter 900. In another embodiment, the two functions can be implemented by using a single controller to simplify Figure 14 the configuration shown in. In this embodiment, the XRD station 350 communicates directly with a controller that also controls the ion implanter 900. Specifically, when a new cassette enters the ion implanter, the controller uses the orientation information that has most recently been received from the XRD station 350. The controller then uses this orientation information to directly control the platen 160. Thereafter, the ion implanter 900 is enabled so that implantation can be performed.

[0096] Although the above disclosure mentions SiC workpieces, it should be understood that the system is not limited to silicon carbide. In one embodiment, if the geometry of the workpiece is known, the X-ray source 110 and the X-ray detector 130 can be moved to appropriate angles to satisfy Bragg's equation. The movement of the components can be done manually or can be controlled by the controller 280.

[0097] In another embodiment, the system can be used for workpieces of various geometries. In this embodiment, Figure 4 the collimator 115 shown in may not be used to enable the emitted X-ray beam 120 to have a much wider angular range. In this embodiment, the X-ray source 110 can generate a wide spectrum of energy or wavelengths so that Bragg's equation can be satisfied for a wide range of lattice spacings and scattering angles. This can be achieved by using a tungsten target and a high enough electron energy to produce Bremsstrahlung rather than characteristic X-ray energy.

[0098] In this way, Bragg's equation can be satisfied over a larger angular range, and one configuration of the X-ray source 110 and the X-ray detector 130 can be used to accommodate many different crystal types.

[0099] In another embodiment, the X-ray source 110 can use a wide angular range to determine the type of crystalline structure that the workpiece has. Once the crystalline structure is determined, the X-ray source 110 and the X-ray detector 130 can be moved to angles appropriate for the crystalline structure. For example, the X-ray source 110 and the X-ray detector 130 may be capable of moving such that the X-ray source 110 and the X-ray detector 130 can be moved to facilitate setting appropriate angles. At this time, the X-ray source 110 can also introduce the collimator 115, which enables the emitted X-ray beam 120 to use a narrower angular range. In this way, the controller 280 performs a rough rocking curve test to determine the crystalline structure and then performs a fine rocking curve test to identify the guiding direction.

[0100] The above embodiments in this application can have many advantages. Using XRD in the processing chamber enables precise control of the incident angle of the ion beam 230. This maximizes the degree of channeling in the workpiece. At a given energy, channeling can enable deeper implantation. In some tests, compared to non-channeled implantation, when channeled implantation is performed, the peak concentration of ions can be deeper by 0.5 microns. In another test, when channeled implantation is performed, the concentration of ions can be more box-shaped. Additionally, channeling can reduce the amount of damage caused by implantation. In certain embodiments, the amount of damage is reduced sufficiently such that the workpiece is not heated before implantation, thereby reducing the time spent in the processing chamber. Additionally, using XRD reduces the likelihood of misorientation of the workpiece and thus a larger yield can be achieved.

[0101] In addition, Figure 10-13 the embodiments in improve throughput by performing an XRD test only once on each workpiece regardless of how many times the workpiece enters the ion implanter. By associating the orientation information collected by the XRD station 350 with a specific workpiece, the central controller no longer needs to repeatedly perform XRD tests. Instead, it simply retrieves a table that includes a list of unique workpiece identifiers and the orientation information associated with each unique workpiece identifier. This can greatly improve throughput, especially in a sequence where there are multiple implantation processes.

[0102] In addition, using the central controller to associate unique workpiece identifiers with associated orientation information enables the XRD station to be placed anywhere, even in a separate location. Therefore, the XRD station does not have to be incorporated into a processing chamber or an EFEM where space is very limited.

[0103] The scope of the present disclosure is not limited by the specific embodiments set forth herein. In fact, from the above description and the drawings, various other embodiments of the present disclosure and various modifications to the present disclosure will be apparent to those skilled in the art in addition to the embodiments and modifications set forth herein. Therefore, those other embodiments and modifications are all intended to fall within the scope of the present disclosure. Additionally, although the present disclosure has been described herein for a particular purpose in a particular environment in the context of a particular embodiment, those skilled in the art will recognize that the utility of the present disclosure is not limited thereto and that the present disclosure can be beneficially implemented for any number of purposes in any number of environments. Therefore, the scope of the following claims should be understood in light of the full scope and spirit of the present disclosure set forth herein.

Claims

1. A system, comprising: An ion implanter including an ion source for generating an ion beam; A processing chamber including a platen for supporting a workpiece having a crystalline structure; An equipment front-end module (EFEM) communicating with the processing chamber via a load lock; An X-ray diffraction station for performing a rocking curve test and determining orientation information of the workpiece based on a result of the rocking curve test to facilitate guiding the ion beam into the crystalline structure of the workpiece; A reader associated with the X-ray diffraction station for detecting an identifier, wherein the identifier is used to create a unique workpiece identifier; And A central controller communicating with the reader and the X-ray diffraction station to associate the orientation information from the X-ray diffraction station with the unique workpiece identifier.

2. The system according to claim 1, wherein the X-ray diffraction station is located within the equipment front-end module.

3. The system according to claim 2, wherein the workpiece is disposed in a cassette, wherein the cassette includes a cassette number as the identifier, and a combination of the cassette number and a slot number is used to create the unique workpiece identifier, wherein the reader determines the cassette number based on a radio frequency identification tag on the cassette, and wherein after receiving the cassette number from the reader, the central controller determines whether an X-ray diffraction test has been performed on the workpiece in the cassette.

4. The system according to claim 3, further comprising an atmospheric robot disposed in the equipment front-end module, wherein if the X-ray diffraction test has been performed on the workpiece in the cassette, the central controller instructs the atmospheric robot to directly transfer the workpiece to the load lock, and if the X-ray diffraction test has not been performed on the workpiece, the central controller instructs the atmospheric robot to transfer the cassette to the X-ray diffraction station.

5. The system according to claim 2, wherein the reader determines the unique workpiece identifier, and after receiving the unique workpiece identifier from the reader, the central controller determines whether an X-ray diffraction test has been performed on the workpiece.

6. The system according to claim 5, further comprising an atmospheric robot disposed in the equipment front-end module, wherein if the X-ray diffraction test has been performed on the workpiece, the central controller instructs the atmospheric robot to directly transfer the workpiece to the load lock, and if the X-ray diffraction test has not been performed on the workpiece, the central controller instructs the atmospheric robot to transfer the workpiece to the X-ray diffraction station.

7. The system according to claim 1, wherein the central controller controls the platen directly or indirectly based on the orientation information associated with the unique workpiece identifier.

8. The system according to claim 1, wherein the X-ray diffraction station is located outside the ion implanter, the equipment front-end module, and the processing chamber.

9. The system according to claim 8, further comprising an additional reader disposed in the equipment front-end module or in the processing chamber.

10. The system according to claim 9, wherein after performing the rocking curve test, the workpiece is transferred from the X-ray diffraction station to the front-end module of the equipment, and the unique workpiece identifier is detected by the additional reader located in the front-end module of the equipment or in the processing chamber, and the unique workpiece identifier is transmitted to the central controller.

11. The system according to claim 10, wherein if the central controller determines that the X-ray diffraction process has been performed on the workpiece, the central controller controls the platen directly or indirectly based on the orientation information associated with the unique workpiece identifier.

12. The system according to claim 10, wherein if the central controller determines that the X-ray diffraction process has not been performed on the workpiece, the central controller reports an error.

13. The system according to claim 9, wherein the workpiece is disposed in a cassette and the reader detects the cassette number, and the cassette number is combined with the slot number to create the unique workpiece identifier, and wherein, After performing the rocking curve test on all the workpieces in the cassette, the cassette is transferred from the X-ray diffraction station to the front-end module of the equipment, and the unique workpiece identifier is detected by the additional reader located in the front-end module of the equipment or in the processing chamber, and the unique workpiece identifier is transmitted to the central controller.

14. The system according to claim 8, further comprising: A second X-ray diffraction station located outside the front-end module of the equipment and the processing chamber; A second reader associated with the second X-ray diffraction station to determine a unique workpiece identifier; And wherein the central controller communicates with the second reader and the second X-ray diffraction station to receive the unique workpiece identifier and associate orientation information with the unique workpiece identifier.

15. A system comprising: An ion implanter including an ion source for generating an ion beam; A processing chamber including a platen for supporting a workpiece having a crystalline structure; A front-end module (EFEM) of the equipment communicating with the processing chamber via a load lock; An X-ray diffraction station for performing a rocking curve test and determining orientation information of the workpiece based on the result of the rocking curve test to facilitate guiding the ion beam into the crystalline structure of the workpiece, wherein the X-ray diffraction station is not located in the front-end module of the equipment or the processing chamber; And A controller communicating with the X-ray diffraction station to receive the orientation information from the X-ray diffraction station and directly or indirectly control the platen based on the orientation information.

16. The system according to claim 15, further comprising a second controller dedicated to the ion implanter, wherein the controller forwards the orientation information to the second controller to control the platen.

17. The system according to claim 16, further comprising: A second X-ray diffraction station located outside the front-end module of the equipment and the processing chamber; wherein the controller communicates with the second X-ray diffraction station to receive the orientation information from the second X-ray diffraction station.

18. A system comprising: An ion implanter including an ion source for generating an ion beam; A processing chamber, including a platen for supporting a workpiece having a crystalline structure; A reader; And A controller, communicating with the reader, wherein the controller includes a table or other data structure associating a unique workpiece identifier with orientation information, and wherein the controller receives the unique workpiece identifier from the reader, associates the orientation information with the unique workpiece identifier, and controls the platen directly or indirectly based on the orientation information.

19. The system according to claim 18, further comprising a second controller dedicated to the ion implanter, wherein the controller forwards the orientation information to the second controller to control the platen.

20. The system according to claim 18, further comprising an equipment front end module (EFEM) communicating with the processing chamber via a load lock; wherein the reader is disposed in the equipment front end module or the processing chamber.

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