In-situ, pre-infusion wafer characterization system and method

Abstract

An ion implantation system includes a wafer inspection system for inspecting a wafer prior to ion implantation. Diagnostics are facilitated by helping to distinguish between performance of the ion implantation process and performance of upstream processes that affect the ion implantation process. Inspection can be performed while the wafer is on an aligner (25), while in a load lock chamber (17A, 17B), or while the wafer is otherwise being processed by a wafer handling system (11) in a terminal station (100). The inspection can be performed without adding to wafer processing delay. Inspection can include modulated optical resonance (MOR) spectroscopy, and can be performed through an optical fiber (23). An optical path can include a wavelength coupler so that a pump laser and a probe laser of the MOR system can be focused through the same lens (21) on a precisely determined inspection point.

Description

[0001] Cross-references to related applications This application claims priority to U.S. Provisional Application No. 63 / 619,339, filed January 10, 2024, the entire contents of which are incorporated herein by reference. Background Technology

[0002] Ion implantation systems are used in the integrated circuit (IC) device manufacturing industry for damage engineering and to provide a controlled dose of impurities to semiconductor wafers. Masks are used to define the pattern to be implanted. Factors such as implantation depth and concentration distribution can be varied by selecting the operating parameters of the ion implantation system. Manufacturing IC devices involves multiple ion implantations with various patterns, different types of impurities, different concentrations, and various depths. Attached Figure Description

[0003] Figure 1 A terminal station for an ion implantation system is shown according to some aspects of this disclosure.

[0004] Figure 2 An aligner according to some embodiments is shown.

[0005] Figure 3 A wafer inspection system according to some embodiments is shown.

[0006] Figure 4 This is another illustration of a wafer inspection system according to some embodiments.

[0007] Figure 5 An ion implantation system according to some embodiments is shown.

[0008] Figure 6 A terminal station for an ion implantation system according to some embodiments is shown.

[0009] Figure 7 A terminal station for an ion implantation system according to some embodiments is shown.

[0010] Figure 8 A terminal station robot according to some embodiments is shown.

[0011] Figure 9 A terminal station for an ion implantation system according to some embodiments is shown.

[0012] Figures 10A to 10C A workpiece transporter according to some embodiments is shown.

[0013] Figure 11 Flowcharts of methods according to some aspects of this disclosure are provided. Detailed Implementation

[0014] This disclosure provides numerous different embodiments or examples for implementing various features of this disclosure. Specific components and arrangements are provided to illustrate and demonstrate this disclosure. These specific examples should not be construed as limiting the scope of the claims.

[0015] One aspect of this disclosure relates to an ion implantation system that provides a wafer inspection prior to ion implantation. The success of ion implantation depends on the state of the wafer prior to the ion implantation process. For example, ion implantation at shallower depths is typically performed after one or more ion implantations at greater depths. The correct dosage for ion implantation at shallower depths depends not only on the desired charge carrier concentration at the shallower depth but also on the type and concentration of dopant left by previous ion implantation processes. These process variations can affect the current process.

[0016] Another factor affecting current ion implantation processes is the crystal structure of the substrate. The depth of ion implantation is strongly influenced by disorder (amorphization) in the crystal structure. In some cases, the crystal structure is intentionally partially amorphized to control the implantation depth. In other cases, the crystal structure becomes partially amorphous accidentally or unintentionally. For all these reasons, the inventors have found that inspections of the wafer after ion implantation are often insufficient to determine whether the current ion implantation process is operating as intended or requires adjustment. This disclosure addresses this problem by providing an ion implantation system with a built-in wafer inspection system that allows for immediate inspection of the wafer prior to ion implantation.

[0017] An ion implantation system may include an ion source, a beamline, a terminal station, and a wafer transport system. The wafer transport system, located in the terminal station, transports the wafer from a wafer carrier at or near atmospheric pressure to a workpiece transporter under vacuum in the terminal station's processing chamber. The ion source generates an ion beam, the beamline guides the ion beam, and the workpiece transporter holds the wafer in the path of the ion beam. The workpiece transporter defines an implantation plane, which is the plane on which the ion beam impacts the wafer. In some embodiments, the workpiece transporter is configured to move the wafer across the path of the ion beam while holding it on a fixed implantation plane.

[0018] In some embodiments, the wafer transport system includes a load lock, an aligner, and one or more robots. The aligner rotates the wafer to orient it relative to alignment marks set on the wafer. The aligner is used because the depth of ion implantation can vary relative to the angle of incidence of the ion beam relative to the wafer's crystal structure orientation. The load lock system is used to transfer the wafer from a state at or near atmospheric pressure outside the processing chamber to a vacuum state inside the processing chamber. A first robot can pull the wafer from a wafer carrier and place it on the aligner. After the wafer has been aligned, a second robot can remove the wafer from the aligner and place it in the load lock chamber. After the load lock chamber is evacuated, a third robot can remove the wafer from the load lock chamber and place it on a wafer processor. A workpiece transporter can place the wafer on the implantation plane and can scan the wafer along the implantation plane. Alternatively, the aligner may be located within the processing chamber.

[0019] In some embodiments, inspection is performed while the wafer is in the load-lock chamber. The wafer remains in the load-lock chamber while it is being evacuated. This provides an opportunity to inspect the wafer without increasing process time. In some alternative embodiments, the wafer carrier is transported through the load-lock chamber instead of the individual wafer, and inspection within the load-lock chamber may be impractical.

[0020] In some embodiments, inspection is performed while the wafer is on the aligner. The wafer can remain stationary on the aligner for a short period. Scanning can be performed during this short period without increasing wafer processing time. In some embodiments, the wafer is inspected after alignment. Post-alignment inspection provides accurate determination of inspection points on the wafer. In some embodiments, the inspection is performed closer to the periphery of the wafer rather than the center. Using points closer to the periphery as inspection points facilitates holding the output coupler or other inspection head of the wafer inspection system in a fixed position close to the wafer surface while the wafer is on the aligner. When the wafer is loaded onto the aligner, positioning the inspection head closer to the periphery facilitates sliding the wafer under the inspection head. Another advantage of performing inspection on the aligner is that the aligner provides convenient attachment points for components of the wafer inspection system.

[0021] In some embodiments, the inspection is a point-by-point inspection. Point-by-point inspection has advantages over full wafer scanning, including the ability to complete the inspection quickly and with smaller equipment. In some embodiments, the wafer on the aligner is inspected at multiple inspection points, all equidistant from the center of the wafer. The ability of the aligner to rotate the wafer provides the opportunity for rapid and accurate repositioning of the wafer, allowing inspection to be performed at multiple inspection points using a fixed inspection head.

[0022] In some embodiments, inspection is performed while the wafer is held in a gripper of a robotic arm in a wafer transport system. The wafer can remain stationary on the robotic arm while awaiting its destination (e.g., an aligner, load lock chamber, or workpiece transporter) to be cleared. This pause provides an opportunity to inspect the wafer without increasing wafer handling time.

[0023] In some embodiments, the inspection is performed while the wafer is on the workpiece transporter. The inspection can also be performed when the wafer is in a first orientation. The first orientation facilitates inspection. The workpiece transporter can then reorient the wafer so that its surface is on the injection plane.

[0024] In some embodiments, the inspection is performed via optical fiber. Inspection via optical fiber provides flexibility in positioning other components of the inspection system. In some embodiments, components of the inspection system are located outside the processing chamber. In some embodiments, this component is a laser. In some embodiments, this component is a photodetector. Placing components of the inspection system outside the processing chamber can extend their lifespan. In some embodiments, components of the inspection system are mounted on an aligner. Mounting this component to the aligner provides a short path for the optical fiber extending from this component to an output coupler that remains fixed above the aligner.

[0025] In some embodiments, the inspection system is a modulated optical reflection (MOR) system. The MOR system includes a pump laser, a probe laser, and a photodetector. In some embodiments, the MOR system includes optical circuitry comprising an optical fiber and a wavelength coupler. The wavelength coupler facilitates focusing the pump laser and probe laser onto the same inspection point. The wavelength coupler allows the pump laser output, the probe laser output, and the reflection of the probe laser from the inspection point to be transmitted through a single optical fiber and a single lens in the output coupler attached to that single optical fiber.

[0026] In some embodiments, the output coupler, including a lens located at the end of the optical fiber, is held in a fixed position directly above the inspection point. Holding the output coupler in a fixed position eliminates sources of variability in the inspection data. In some embodiments, the output coupler is movable. For example, a robot can be provided to move the position of the output coupler. A movable output coupler facilitates wafer inspection without interfering with the normal movement of the wafer through the terminal station. The lens can focus the outputs of the pump laser and the probe laser onto the inspection point and can collimate the probe laser from the reflection at the inspection point into the optical fiber. In some embodiments, the pump laser is modulated at a single frequency. Using a single frequency for each inspection (as opposed to frequency scanning) allows for rapid inspection and adequately demonstrates the purpose of the wafer inspection system.

[0027] The wafer inspection system provides inspection data that can be used to diagnose and determine wafer defects. In some embodiments, the wafer is discarded based on the diagnostic determination. In some embodiments, remedial processing is performed on the wafer based on the diagnostic determination. Ion implantation may be postponed until the remedial processing is complete. In some embodiments, ion implantation performed after inspection is modified based on the diagnostic determination. In some embodiments, the operation of processing tools upstream of the ion implantation system is modified based on the diagnostic determination.

[0028] In some embodiments, making a diagnostic determination based on inspection data includes comparing the inspection data with previously acquired inspection data. In some embodiments, the previously acquired inspection data is obtained by an inspection system by inspecting one or more previously processed wafers. In some embodiments, a second inspection is performed on the wafer after ion implantation, and a diagnostic determination is made by comparing the result of the second inspection with the result of the first inspection.

[0029] Figure 1 A terminal station 100 for an ion implantation system according to some embodiments of the present disclosure is shown. The terminal station 100 includes a processing chamber 13 and a front-end module 29. The processing chamber 13 is under vacuum and is where wafer 122 is implanted. The front-end module 29 is maintained at or near atmospheric pressure. An alignment device 25, a first robot 27A, and a second robot 27B are disposed in the front-end module 29. A workpiece transporter 175, a third robot 15B, and a fourth robot 15A are disposed in the processing chamber 13.

[0030] A first robot 27A passes through one of the loading ports 31, removes a wafer 122 from the wafer carrier 35, and places it on the alignment device 25. The wafer carrier 35 is a multi-wafer transport module, such as a wafer cassette or wafer box. In some embodiments, the wafer carrier 35 is a front-opening wafer transport cassette (FOUP). Automated overhead conveyors or some other transport system can be used to move the wafer carrier 35 between ion implantation systems and other workstations in an integrated circuit (IC) manufacturing plant.

[0031] Aligner 25 rotates wafer 122 and sets its angular orientation relative to alignment marks 26 on wafer 122. Wafer inspection system 20 inspects wafer 122 while it is positioned on alignmenter 25. Wafer inspection system 20 includes optical fiber 23, output coupler 21, and assembly 19. Assembly 19 is mounted on one side of alignmenter 25. Output coupler 21 can be held in a fixed position for inspecting wafer 122 at inspection points near the wafer periphery.

[0032] The first load chamber 17B and the second load chamber 17A are located between the front-end module 29 and the processing chamber 13. The second robot 27B removes the wafer 122 from the alignment device 25 and places it in the first load chamber 17B. After the first load chamber 17B is evacuated, the third robot 15B removes the wafer 122 and places it on the workpiece transporter 175.

[0033] Ion implantation is performed while wafer 122 is held by workpiece transporter 175. Workpiece transporter 175 reorients wafer 122 to align wafer 122 on the implantation plane. In some embodiments, workpiece transporter 175 sweeps across wafer 122 in a slow scan direction across beam path 112a while holding wafer 122 on the implantation plane. In some embodiments, workpiece transporter 175 remains stationary while beam path 112a sweeps across wafer 122 in both fast and slow scan directions.

[0034] After ion implantation, the fourth robot 15A removes the wafer 122 from the workpiece transporter 175 and places it in the second load lock chamber 17A. After the wafer 122 is subjected to pressure from the front-end module 29, the fourth robot 15A extracts the wafer 122 from the second load lock chamber 17A and places it back into one of the wafer carriers 35.

[0035] The components in terminal station 100 that hold and transport wafer 122 between wafer carrier 35 and workpiece transporter 175 constitute wafer transport system 11. In wafer transport system 11, wafer 122 is brought into processing chamber 13 via first load lock chamber 17B and removed from processing chamber 13 via second load lock chamber 17A. However, both load lock chambers 17A and 17B can be used to transport wafer 122 to and from processing chamber 13. Furthermore, more or fewer load lock chambers 17A and 17B can be provided.

[0036] The wafer transport system 11 uses a fourth robot 15A to transport processed wafers 122 within the processing chamber 13, and a third robot 15B to transport unprocessed wafers 122. However, it is understood that the fourth robot 15A can also transport unprocessed wafers 122, and the third robot 15B can also transport processed wafers 122. Furthermore, the wafer transport system 11 may have more or fewer robots in the processing chamber 13.

[0037] The wafer transport system 11 uses a first robot 27A to transport processed wafers 122 to the wafer carrier 35 and unprocessed wafers 122 to the aligner 25. The wafer transport system 11 uses a second robot 27B to transport wafers from the aligner to the first load lock chamber 17B. These functions can be otherwise distributed between the first robot 27A and the second robot 27B, and can be distributed among more or fewer robots within the front-end module 29. The number of loading ports 31 through which the robots access the wafer carrier 35 can also vary without departing from the spirit and scope of this disclosure.

[0038] Figure 2 A top view of 200 is provided, which is more efficient than... Figure 1 The more detailed description provided illustrates an example of the alignment device 25. The alignment device 25 includes a base 207, a workpiece support 201, a chuck 205, and an alignment mark detection device 209. The workpiece support 201 may have an arcuate recess 203 configured to support the periphery of the wafer 122. The chuck 205 may be rotatably mounted to the base 207, enabling it to clamp and rotate the wafer 122. For example, the chuck 205 may be a vacuum chuck or an electrostatic chuck. The alignment mark detection device 209 may be an optical sensor or some other type of sensing device capable of detecting alignment marks. The wafer inspection system 20 includes a component 19 mounted on one side of the base 207 and an output coupler 21 held above the position occupied by the wafer 122 when the wafer 122 is held by the workpiece support 201.

[0039] Figure 3 A MOR system 300 providing a wafer inspection system 20 is shown. The MOR system 300 includes a pump laser 301, a wavelength coupler 305, a probe laser 309, a circulator 313, a photodetector 317, and an output coupler 21. Light 318 from the pump laser 301 is transmitted via optical fiber 303 to the wavelength coupler 305 and via optical fiber 23 from the wavelength coupler 305 to the output coupler 21. The output coupler 21 includes a lens that focuses the light 318 onto a wafer 122. The light 318 excites a response at an inspection point on the wafer 122. The light 318 can be modulated to facilitate the detection of a time-varying response in the wafer 122. In some embodiments, the modulation is amplitude modulation. Alternatively or additionally, the light 318 can be frequency modulated.

[0040] Light 316 from the probe laser 309 is transmitted via fiber 311 to circulator 313, via fiber 307 from circulator 313 to wavelength coupler 305, and via fiber 23 from wavelength coupler 305 to output coupler 21. A lens in output coupler 21 focuses light 316 onto a check point. Some of the light 316 is reflected from the check point with an intensity that varies over time, influenced by light 318 from pump laser 301 and related to the characteristics of wafer 122 at the check point. The reflected light 316 is collimated by the lens in output coupler 21, transmitted from output coupler 21 via fiber 23 to wavelength coupler 305, from wavelength coupler 305 via fiber 307 to circulator 313, and from circulator 313 via fiber 315 to photodetector 317. Optical fibers 23, 303, 307, 311, and 315, wavelength coupler 305, circulator 313, and output coupler 21 constitute the optical path.

[0041] Figure 4 An illustration of the MOR system 300 is provided, with the optical fiber removed and additional details shown for the wavelength coupler 305, circulator 313, and output coupler 21. Figure 4 As shown, the circulator 313 can be a one-way mirror that transmits light 316 approaching from the direction of the probe laser 309 and reflects light approaching from the direction of the wavelength coupler 305. The wavelength coupler 305 can be a mirror that reflects light 316 from the probe laser 309 and transmits light 318 from the pump laser 301. The output coupler 21 can be a lens at the end of the fiber 23 (see...). Figure 3 ).

[0042] Pump laser 301 has a wavelength suitable for generating electron-hole pairs in wafer 122, which is a semiconductor. This semiconductor may be silicon (Si) or some other semiconductor material. In some embodiments, the wavelength is about 1 µm or less. In some embodiments, the frequency is in the blue portion of the visible spectrum. In some embodiments, pump laser 301 is an argon laser, and light 318 has a wavelength of about 0.5 µm. In some embodiments, pump laser 301 is a laser diode. A laser diode can provide light with wavelengths of about 405 nm, about 785 nm, or some other suitable wavelength. Pump laser 301 is powered by electronics that allow its output amplitude to be modulated. In some embodiments, the amplitude is modulated at frequencies ranging from about 1 kHz to about 40 kHz. Amplitude modulation within this range can be provided with inexpensive electronics. In some embodiments, the amplitude is modulated at frequencies ranging from about 40 kHz to about 1 MHz. Amplitude modulation within this range, while requiring more expensive electronics, can provide more information in a shorter time.

[0043] The charge carrier concentration variation induced by the pump laser 301 affects the dielectric constant of wafer 122 at the check point, and consequently, the refractive index. The pump laser 301 also causes localized heating within wafer 122 at the check point, which also affects the refractive index. Both effects cycle with amplitude modulation. These cycles are out of phase, allowing information to be extracted from both types of effects.

[0044] The probe laser 309 can operate at a constant amplitude, such that amplitude modulation in the reflected light 316a at the photodetector 317 is attributable to the influence of light 318 from the pump laser 301. The probe laser 309 can produce light with a longer wavelength (lower energy) than that from the pump laser 301. In some embodiments, the light 316 from the probe laser 309 has a wavelength of about 0.6 µm or greater. In some embodiments, the probe laser 309 is a helium-neon laser. In some embodiments, the probe laser 309 is a laser diode.

[0045] Figure 5 An exemplary ion implantation system 500 is illustrated, comprising a terminal 102, a beamline 104, and a terminal station 100. The terminal 102 includes an ion source 108 powered by a high-voltage power supply 110 to generate ions, which are extracted and formed into an ion beam 112. The beamline 104 filters, shapes, and guides the ion beam 112 to provide an x-axis scan. A workpiece transporter 175 in the terminal station 100 provides a y-axis scan. Optionally, the beamline 104 guides the ion beam 112 to provide both x-axis and y-axis scans.

[0046] Ion source 108 may include an arc chamber 114 and an ion extraction assembly 118. Arc chamber 114 is supplied with a gas containing the species to be injected. Within arc chamber 114, electrons are generated by an electron source. The electron source may be a filament or cathode heated by an electric current from a high-voltage power supply 110 to induce thermionic emission of thermionic electrons. The electrons can be induced into an arc and ionize some of the gas in arc chamber 114, thereby generating plasma. A magnetic field may be provided to hold the plasma in an eddy current. Ions can be controllably extracted from the plasma and accelerated to beamline energy by ion extraction assembly 118. Ion extraction assembly 118 may include electrodes 120 for accelerating the extracted ions.

[0047] Beamline 104 may include a mass analyzer 126, a beam shaping and guiding system 140, a scanning system 128, and a parallelizer 130. The mass analyzer 126 filters ions based on charge-to-mass ratio, such that after the mass analyzer 126, the ion beam 112 is a purified ion beam containing only selected ions. In the illustrated example, the mass analyzer 126 includes a bend through which ions are deflected by a magnetic field. Ions with incorrect charge-to-mass ratios will be over- or under-deflected, ensuring that only ions with the desired charge-to-mass ratio continue downwards along beamline 104 from the mass analyzer 126.

[0048] The beam shaping and guiding system 140 includes one or more electrical or magnetic lenses 148 for compressing and guiding the ion beam 112. In some embodiments, the beam shaping and guiding system 140 includes a first quadrupole magnet (x-quad) that compresses the ion beam 112 in the x-direction and a second quadrupole magnet (y-quad) that compresses the ion beam 112 in the y-direction. The y-direction is the direction into which the ion beam 112 enters. Figure 5 Page orientation.

[0049] Scanning system 128 guides ion beam 112 such that the beam path 112a of ion beam 112 sweeps across the x-direction (fast scan direction). Scanning system 128 may include plate 146. Plate 146 may guide ion beam 112 electrically or magnetically. In some embodiments, scanning system 128 periodically scans beam path 112a at a rate of about 1 kHz or higher. The scanning rate in the y-direction (slow scan direction) is slower, for example, about 100 Hz or lower.

[0050] The scanned ion beam 112 can pass through the parallelizer 130. In the example shown, the parallelizer 130 includes two dipole magnets 154. These two dipole magnets 154 may be substantially trapezoidal and are oriented to be mirror images of each other, bending the beam path 112a into an S-shape. The parallelizer 130 has the effect of making all beam paths 112a substantially parallel.

[0051] Ion beam 112 is received by terminal station 100. Optionally, a deceleration stage 156 is disposed within terminal station 100 downstream of parallelizer 130. Deceleration stage 156 may include one or more electrodes 158 for slowing down ion beam 112 and focusing ion beam 112 into a converging stream. In some embodiments, beamline 104 is maintained at a first potential, and deceleration stage 156 is maintained at a second potential, wherein the first potential corresponds to beamline energy and the second potential corresponds to injected energy. The means for focusing ion beam 112 may be integrally formed with the means for slowing down ion beam 112. In some embodiments, deceleration stage 156 includes a single lens.

[0052] A control system 168 is provided to control, communicate, and / or adjust the ion source 108, the mass analyzer 126, the scanning system 128, the deceleration stage 156, and the workpiece transporter 175. The control system 168 can also control the wafer transport system 11 and the wafer inspection system 20 (see...). Figure 1 Alternatively, it can communicate with one or more similar control systems provided for the wafer transport system 11 and the wafer inspection system 20. The control system 168 may include a computer comprising a central processing unit and a storage system programmed with instructions for operating these and other components of the ion implantation system 500. For example, the control system 168 may determine the ion generation rate, beamline energy, fast scan rate, implantation energy, and slow scan rate in the ion source 108. The control system 168 may receive a set of operating parameters constituting a recipe by which an operator can guide the ion implantation system 500 to perform specific and repeatable ion implantation operations. The control system 168 can operate the wafer transport system 11 to maximize throughput and can analyze and (in some cases) respond to data from the wafer inspection system 20.

[0053] Figure 6 A terminal station 600 according to another embodiment is shown. Terminal station 600 is similar to... Figure 1 The terminal station 600 differs from terminal station 100 in that, in terminal station 600, wafer inspection system 20 is configured to inspect wafer 122 when it is located in first load lock chamber 17B. Optical fiber 23 can pass through a vacuum-sealed port at the top of first load lock chamber 17B, such that output coupler 21 is located inside first load lock chamber 17B, while component 19 is located outside first load lock chamber 17B. In some embodiments, component 19 is attached to one side of first load lock chamber 17B.

[0054] like Figure 6 As shown, terminal station 600 may include a second wafer inspection system 620 installed in the second load lock chamber 17A. The second wafer inspection system 620 is provided for inspecting wafer 122 after ion implantation. The output coupler 21 of the second wafer inspection system 620 may be positioned to inspect wafer 122 at the same point as the wafer inspection system 20 to facilitate comparison of data from the second wafer inspection system 620 with data from the wafer inspection system 20. This point is an angular distance 601 from alignment mark 26.

[0055] Figure 7 A terminal station 700 according to another embodiment is shown. The terminal station 700 is similar to... Figure 1The terminal station 100 differs from the terminal station 700 in that, in terminal station 700, wafer inspection system 20 is configured to inspect wafer 122 while it is held by a second robot 27B or another robot of wafer transport system 11. In some embodiments, component 19 is located inside front-end module 29. In some embodiments, component 19 is located outside front-end module 29, and optical fiber 23 passes through the wall of front-end module 29, such as... Figure 7 As shown.

[0056] Robot 27B can have any suitable structure. Figure 8 The configuration of a second robot 27B according to some embodiments is shown. Figure 8 As shown, the second robot 27B includes a base 807, three pivot joints 809, two arms 801, and an actuator 803. The actuator 803 may have an arcuate recess 805 for supporting the wafer 122 at its periphery. In some embodiments, the arms 801 may be raised or lowered relative to the base 807. These features, or similar features, allow the second robot 27B to position the wafer 122 below the output coupler 21 (see...). Figure 7 This allows the wafer 122 to be inspected while being held by the actuator 803. Instead of the mechanical actuator 803, the second robot 27B may have an electrostatic chuck, a vacuum chuck, or some other device that can hold or support the wafer 122 when it is moved by the second robot 32B. Robots 27A, 15A, and 15B may have similar configurations.

[0057] Figure 9 A terminal station 900 according to another embodiment is shown. The terminal station 900 is similar to... Figure 1 The terminal station 900 differs from the terminal station 100 in that, in the terminal station 900, the wafer inspection system 20 is configured to inspect the wafer 122 while it is held by the workpiece transporter 175. In some embodiments, component 19 is located inside the processing chamber 13. In some embodiments, component 19 is located outside the processing chamber 13, and optical fiber 23 passes through the wall of the processing chamber 13, such as... Figure 9 As shown.

[0058] Figures 10A to 10C An example of a workpiece transporter 175 according to some embodiments is shown. For example... Figure 10A Paper Figure 10CAs shown, the workpiece transporter 175 includes a base 1001, an arm 1005, an arm 1007, and a chuck 1009. The chuck 1009 can be a mechanical chuck, an electrostatic chuck, a vacuum chuck, or some other type of chuck suitable for holding the wafer 122 during ion implantation. The chuck 1009 is pivotally connected to the arm 1007 via a joint 1011. The arm 1007 is pivotally connected to the arm 1005 via a joint 1013. The arm 1005 is pivotally connected to the base 1001 via a joint 1003.

[0059] like Figure 10A As shown, when wafer 122 is powered by the third robot 15B (see...) Figure 9 When received, wafer 122 can be oriented in the y-direction. The y-direction can be vertical. Wafer 122 can be inspected while having this orientation.

[0060] like Figure 10B As shown, wafer 122 can rotate around joint 1011, so that wafer 122 is oriented in the injection plane (compare). Figure 5 The injection plane is selected based on the desired orientation of wafer 122 relative to beam path 112a. Beam path 112a is in the z-direction and... Figure 10B and Figure 5 In the example shown, the injection plane is set perpendicular to the z-direction. Alternatively, the injection plane may be at an angle relative to the z-direction. Figure 10C As shown, by coordinating rotation around joints 1003, 1011 and 1013, the wafer 122 can be scanned in the y-direction while keeping the wafer 122 oriented on the injection plane.

[0061] Figure 11 A flowchart of method 1100 is provided, which can be implemented using ion implantation system 500 in conjunction with one of terminal stations 100, 600, 700, or 900. While method 1100 is illustrated and described below as a series of actions or events, it should be understood that the illustrated order of these actions or events should not be construed as limiting. For example, some actions may occur in a different order and / or simultaneously with other actions or events besides those illustrated and / or described herein. Furthermore, not all actions shown are necessary to implement one or more aspects or embodiments described herein.

[0062] Method 1100 can begin with action 1101, which is removing the wafer from the wafer carrier. Figure 1 An example is provided of the first robot 27A in the front-end module 29 performing this action. Optionally, the wafer carrier 35 is transported into the processing chamber 13, and the action occurs in the processing chamber 13.

[0063] Action 1103 is to place the wafer on the aligner. Action 1105 is to use the aligner to set the alignment of the wafer.

[0064] Action 1107 is wafer inspection. In some embodiments, the inspection is performed via optical fiber. In some embodiments, the inspection includes a MOR check. In some embodiments, the inspection is performed while the wafer is on an aligner. Figure 1 An example of a terminal station implementing this embodiment is provided. In some embodiments, the wafer is rotated on an aligner and the inspection is repeated. In some embodiments, the inspection is performed after the wafer has been aligned. In some embodiments, the inspection is performed while the wafer is in a load-locked chamber. Figure 6 An example of a terminal station implementing this embodiment is provided. In some embodiments, the inspection is performed while the wafer is being held by a robot. Figure 7 An example of a terminal station implementing this embodiment is provided. In some embodiments, the inspection is performed while the wafer is held by a workpiece transporter. Figure 9 An example of a terminal station implementing this embodiment is provided.

[0065] Action 1109 is to move the wafer to the load lock chamber. Action 1111 is to evacuate the load lock chamber. Action 1113 is to move the wafer from the load lock chamber to the workpiece transporter. Action 1115 is to perform ion implantation on the wafer while it is held by the workpiece transporter.

[0066] Action 1117 is an optional step that performs a second inspection on the wafer after ion implantation. This second inspection can occur in the processing chamber, the load lock chamber, or the front-end module.

[0067] Action 1119 moves the wafer from the workpiece transporter to the load lock chamber. Action 1121 pressurizes the load lock chamber. Action 1123 moves the wafer from the load lock chamber to the wafer carrier. This wafer carrier can be the same wafer carrier from which the wafer was removed or a different wafer carrier.

[0068] Action 1125 makes a diagnostic determination based on data obtained using action 1107, prior to ion implantation in action 1115. In some embodiments, the diagnostic determination relates to the state of the wafer prior to ion implantation. In some embodiments, the diagnostic determination includes comparing the data with reference data previously obtained by inspecting one or more other wafers. In some embodiments, the diagnostic determination includes determining the free carrier concentration at the inspection point. For example, the parameters required to apply the Drude model to determine the free carrier concentration can be obtained from MOR data.

[0069] In some embodiments, the diagnostic determination includes an assessment of the degree of amorphization. For example, MOR data provides peak values ​​corresponding to the band gap energy. If the material has a highly ordered crystalline structure, these peak values ​​will be sharp. As the degree of amorphization increases, these peak values ​​become more diffuse.

[0070] In some embodiments, the diagnostic determination further includes using data obtained through action 1117, which is a second examination performed after ion implantation in action 1115. In this case, the diagnostic determination can assess the effectiveness of action 1117 in obtaining the desired results.

[0071] Action 1127 is an optional action performed based on diagnostic findings. In some embodiments, action 1127 modifies the parameters of ion implantation in action 1115. For example, the ion implantation dose may be increased or decreased based on the results of the inspection. In some embodiments, the modification is applied to the wafer being inspected. Alternatively or additionally, the modification may be applied to ion implantation performed on other wafers. In some embodiments, remedial actions other than modifying the ion implantation in action 1115 are performed on the wafer being inspected based on diagnostic findings. In some embodiments, ion implantation in action 1115 is skipped on the wafer being inspected based on diagnostic accuracy. For example, ion implantation may be postponed until the wafer has been cleaned or returned to an upstream process that was not properly completed. The upstream process may be another ion implantation process used for doping or damage engineering. In some embodiments, wafers are selectively discarded based on diagnostic findings.

[0072] In some embodiments, upstream processes of the ion implantation system are modified based on diagnostic findings. For example, based on diagnostic findings, the conditions of an earlier ion implantation process used for doping or damage engineering may be modified.

[0073] The foregoing outlines features of several embodiments to enable those skilled in the art to better understand various aspects of this disclosure. Those skilled in the art will understand that they can readily use this disclosure as a basis for designing or modifying other processes and structures to perform the same purposes and / or obtain the same advantages as the embodiments described herein. Those skilled in the art will also recognize that such equivalent constructions do not depart from the spirit and scope of this disclosure, and that various changes, substitutions, and alterations can be made herein without departing from the spirit and scope of this disclosure. Furthermore, while a particular feature may be disclosed with respect to only one of several embodiments, such a feature may be combined with one or more other features from other embodiments to suit the needs or advantages of a given application.

Claims

1. An ion implantation system, comprising: An ion source, configured to generate an ion beam; A beamline, configured to guide the ion beam; A terminal station, which is positioned to receive the ion beam; The workpiece transporter in the terminal station is configured to move the wafer into the path of the ion beam while holding the wafer on a chuck. A wafer transport system within the terminal station, wherein the wafer transport system is configured to move the wafer from the wafer carrier to the workpiece transporter; as well as A wafer inspection system comprising an optical fiber and a lens, wherein the wafer inspection system is configured to inspect the wafer via the optical fiber as the wafer is transported from the wafer carrier to the ion beam.

2. The ion implantation system according to claim 1, wherein, The wafer inspection system is configured to inspect the wafer while it is being processed by the wafer transport system.

3. The ion implantation system according to claim 2, wherein, The wafer inspection system is configured to inspect the wafer while it is in a load lock chamber.

4. The ion implantation system according to claim 2, wherein, The wafer inspection system is configured to inspect the wafer when it is positioned on the aligner.

5. The ion implantation system according to claim 4, wherein, The components of the wafer inspection system are mounted on the aligner.

6. The ion implantation system according to claim 1, wherein, The wafer inspection system is configured to inspect the wafer while it is being held by the workpiece transporter.

7. The ion implantation system according to claim 1, wherein, The terminal station includes a vacuum chamber, and the wafer inspection system is positioned to inspect the wafer when it is located in the vacuum chamber.

8. The ion implantation system according to claim 1, wherein, The wafer inspection system includes a modulated optical reflection system.

9. The ion implantation system according to claim 1, wherein, The wafer carrier is a front-opening wafer transport box.

10. The ion implantation system according to claim 1, wherein, The wafer inspection system further includes a first laser, a second laser, and a wavelength coupler, wherein the wavelength coupler is configured to direct light from both the first laser and the second laser into the optical fiber.

11. An ion implantation system, comprising: An ion source, configured to generate an ion beam; A beamline, configured to guide the ion beam; A terminal station, which is positioned to receive the ion beam; The workpiece transporter in the terminal station is configured to hold the wafer in the path of the ion beam. A wafer transport system including an aligner, wherein the wafer transport system is configured to set the orientation of the wafer using the aligner and transfer the wafer from the aligner to the workpiece transporter; as well as A wafer inspection system comprising an optical fiber, wherein the wafer inspection system is positioned to inspect the wafer via the optical fiber when the wafer is on the aligner.

12. The ion implantation system according to claim 11, wherein, The components of the wafer inspection system are mounted on the aligner.

13. A method of operating an ion implantation system, the method comprising: A wafer is picked up from a wafer carrier using a wafer transport system, which is part of an ion implantation system; Place the wafer on the aligner; Set the alignment of the wafer; A first inspection is performed on the wafer to obtain first inspection data; The wafer is transported from the aligner to the workpiece transporter of the ion implantation system; as well as After the first inspection is performed and while the wafer is held by the workpiece transporter, ion implantation is performed on the wafer.

14. The method according to claim 13, wherein, The first inspection is performed when the wafer is positioned on the aligner.

15. The method according to claim 14, wherein, The first check is performed after the wafer is positioned on the aligner and the wafer alignment is set.

16. The method of claim 14, wherein, The first inspection includes inspecting the wafer when it is in a first orientation, and the method further includes performing a second inspection on the wafer when it is in a second orientation.

17. The method of claim 13, further comprising: A second inspection is performed on the wafer after the ion implantation to obtain second inspection data; as well as A diagnostic determination is provided based on a comparison between the first examination data and the second examination data.

18. The method according to claim 13, wherein, Performing the first check includes modulating the optical reflection spectrum.

19. The method according to claim 18, wherein, Performing the modulated optical reflection spectrum involves using a wavelength coupler to combine the outputs of a pump laser and a probe laser into an optical fiber, and focusing the outputs of the pump laser and the probe laser onto a check point on the wafer.

20. The method according to claim 13, wherein, The ion implantation is performed under conditions set based on the first inspection data.

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