Fast beam calibration procedure for beamline ion implanter

Abstract

To provide a method and an apparatus for controlling beam current in an ion implantation process, which reduce the amount of "tune" time employed for such a calibration process using a uniform current density across the wafer surface.SOLUTION: A method includes receiving a spot beam profile (SpotBP) for the spot ion beam, receiving a linear scanned beam profile (ScannedBP) for the spot ion beam, generating a calculated calibration spot profile on the basis of the spot beam profile and the linear scanned beam profile, and implementing an adjusted scanned profile for the spot ion beam on the basis of the calculated calibration spot profile.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] Related Applications This application claims priority to U.S. Provisional Patent Application No. 63 / 235,508, filed August 20, 2021, entitled "FAST BEAM CALIBRATION PROCEDURE FOR BEAMLINE ION IMPLANTER," and U.S. Non-Provisional Patent Application No. 17 / 700,048, filed March 21, 2022, entitled "FAST BEAM CALIBRATION PROCEDURE FOR BEAMLINE ION IMPLANTER," the entire contents of which are incorporated herein by reference.

[0002] The present embodiments relate to processing apparatus and methods, and more particularly to methods for controlling beam current in ion implantation processes. [Background technology]

[0003] Today, various types of processing equipment are employed to treat or process substrates with ions. To process a substrate, such as a semiconductor substrate, ions can be used to etch layers or features on the substrate. Ions can also be used to deposit layers or structures on the substrate, implant species into the substrate, or amorphize the substrate. Techniques for monitoring the processing of the substrate have also been developed to control the processing of the substrate.

[0004] To provide precise dose control for ion implantation of substrates using a scanned spot beam, a current monitor, such as a Faraday cup monitor, may be provided at or near the substrate. In some ion implanters, a Faraday cup may be provided adjacent to the substrate to intercept the spot beam, which is scanned back and forth along a first direction, to calibrate the ion implantation procedure. Typically, during implantation of a series of substrates (wafers), a beam calibration procedure is performed periodically using such a current monitor to "tune" the scan of the ion beam to ensure that the appropriate ion dose is provided across the wafers.

[0005] There is a constant effort to increase ion implanter productivity by reducing the amount of "tune" time employed for such calibration processes using uniform current densities across the wafer surface. In a given tuning operation to calibrate a scanned spot beam ion implant, a "static" spot beam profile (SpotBP) is obtained in addition to various scanned beam profiles (ScannedBP), in which the beam current is measured while the spot beam is rapidly scanned back and forth along a predetermined scan direction. Each of the various profiles requires a given duration to execute. For example, an average set of 16 SpotBPs may require a duration of 3 seconds, while a single scanned beam profile may require on the order of 12 seconds. Thus, the total calibration time for the ion beam may be at least 27 seconds, including at least one SpotBP and at least two ScannedBPs. Furthermore, the total uniformity tuning or calibration time for the ion beam in this scenario would be 27 seconds for the uniformity tuning, including the calibration time of 27 seconds, plus the ScannedBPs, which involve an additional 12 seconds. AdjustedThis can require at least 39 seconds, since it includes at least one adjusted scan after calibration, called the calibration scan. Note that a given wafer implant procedure may only require a few seconds of time, and thus implanting a batch of 25 wafers may take only a few minutes or less. Thus, when beam calibration is performed before implanting every wafer batch, beam calibration can constitute a large portion of the total implant time, thereby limiting wafer throughput.

[0006] With regard to these and other considerations, present improvements may be needed. Summary of the Invention

[0007] The present embodiments relate to methods, articles, and ion implanters for implementing improved spot beam calibration. In one embodiment, a method may include receiving a spot beam profile for a spot ion beam, receiving a linear scanned beam profile for the spot ion beam, generating a calculated calibration spot profile based on the spot beam profile and the linear scanned beam profile, and implementing an adjusted scanned profile for the spot ion beam based on the calculated calibration spot profile.

[0008] In another embodiment, an apparatus for controlling the scanning of an ion beam is provided. The apparatus may include a beam scanner for scanning a spot ion beam relative to a substrate, a detector for measuring a current of the ion beam, and a beam calibration component comprising a controller and a memory. The memory may include a calibration routine. The calibration routine may be operable on the controller to receive a spot beam profile for the spot ion beam, receive a linear scanned beam profile of the spot ion beam, generate a calculated calibration spot profile based on the spot beam profile and the linear scanned beam profile, and implement an adjusted scanned profile for the spot ion beam based on the calculated calibration spot profile.

[0009] In another embodiment, a non-transitory computer-readable storage medium is provided that includes a set of instructions that, when executed by a computer, can cause the computer to receive a spot beam profile for a spot ion beam, receive a linear scanned beam profile of the spot ion beam, generate a calculated calibration spot profile based on the spot beam profile and the linear scanned beam profile, and implement an adjusted scanned profile for the spot ion beam based on the calculated calibration spot profile. [Brief explanation of the drawings]

[0010] [Figure 1A] FIG. 1 illustrates basic components for a reference ion beam calibration that may be implemented in a spot beam ion implantation system. [Figure 1B] FIG. 1 illustrates basic components for ion beam calibration that may be implemented in a spot beam ion implantation system according to an embodiment of the present disclosure. [Figure 1C]FIG. 1 illustrates basic components for ion beam calibration that may be implemented in a spot beam ion implantation system according to another embodiment of the present disclosure. [Figure 2A] FIG. 10 illustrates a composite illustration including menu items and graphical representations of signals associated with spot beam profiles, according to the present embodiments. [Figure 2B] 1 is a composite illustration including a menu item and a graphical representation of a signal associated with a predicted calibration spot profile. [Figure 3] FIG. 10 shows a comparison of various spot beam calibration and measurement curves. [Figure 4] 10A-10C depict the operations involved in converting a spot beam profile into a predicted calibration spot profile in accordance with various embodiments of the present disclosure. [Figure 5A-5B] 10A-10C depict the operations involved in converting a spot beam profile into a predicted calibration spot profile in accordance with various embodiments of the present disclosure. [Figures 6A-6B] 10A-10C depict the operations involved in converting a spot beam profile into a predicted calibration spot profile in accordance with various embodiments of the present disclosure. [Figure 7A] 10A-10C depict the operations involved in converting a spot beam profile into a predicted calibration spot profile in accordance with various embodiments of the present disclosure. [Figure 7B] 10A-10C depict the operations involved in converting a spot beam profile into a predicted calibration spot profile in accordance with various embodiments of the present disclosure. [Figure 7C] 10A-10C depict the operations involved in converting a spot beam profile into a predicted calibration spot profile in accordance with various embodiments of the present disclosure. [Figure 7D] 10A-10C depict the operations involved in converting a spot beam profile into a predicted calibration spot profile in accordance with various embodiments of the present disclosure. [Figure 7E]10A-10C depict the operations involved in converting a spot beam profile into a predicted calibration spot profile in accordance with various embodiments of the present disclosure. [Figure 8A] 10A-10C depict the operations involved in converting a spot beam profile into a predicted calibration spot profile in accordance with various embodiments of the present disclosure. [Figure 8B] 10A-10C depict the operations involved in converting a spot beam profile into a predicted calibration spot profile in accordance with various embodiments of the present disclosure. [Figure 8C] 10A-10C depict the operations involved in converting a spot beam profile into a predicted calibration spot profile in accordance with various embodiments of the present disclosure. [Figure 9A] FIG. 1 depicts a top view in block form of a beam-line ion implanter according to various embodiments of the present disclosure. [Figure 9B] FIG. 10 illustrates an exemplary block diagram of a memory containing a spot beam calibration routine. [Figure 10] FIG. 1 depicts an exemplary process flow. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present embodiments will now be described more fully hereinafter with reference to the accompanying drawings, in which several embodiments are shown. The subject matter of this disclosure may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Instead, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the subject matter to those skilled in the art. In the drawings, like numbers refer to like elements throughout.

[0012] The embodiments described herein provide beam calibration for ion implanters and novel techniques for improving ion implantation throughput.

[0013] According to various embodiments of the present disclosure, a more rapid approach to ion beam calibration, also referred to as ion beam tuning or beam tuning, is provided. For reference, FIG. 1A illustrates basic components for ion beam calibration that may be implemented in a spot beam ion implantation system, where ion implantation is performed by exposing a substrate to a scanned spot beam. Specifically, the spot beam may be scanned or rastered back and forth across the substrate along a given beam scan axis, for example, at a rate on the order of a few kHz. Exposure of the entire substrate may be achieved by scanning the substrate stage at a much slower rate along a given axis, such as an axis orthogonal to the beam scan axis, while the spot beam is rapidly scanned along the beam scan axis. Prior to substrate exposure, a uniformity tuning routine generates a scanned ion beam in which the ion beam scan speed is adjusted across the beam scan axis so that the substrate is exposed to a uniform ion density. Due to ion beam density uniformity requirements, ion beam tuning may be performed periodically and frequently, such as before each batch of substrates (e.g., a batch of 25 wafers) is implanted. For a given implantation strategy, including a given ion species and a given set of implantation conditions, the entity ScannedBP Adjusted A predetermined calibration procedure for producing this uniform density scanned beam, sometimes referred to as a "calibration procedure," may be implemented before a given batch of wafers is implanted. In the following description, procedures, steps, routines, algorithms, etc. may also be referred to as operations or sub-operations.

[0014] In FIG. 1A, a composite illustration is shown including menu items and graphical representations of signals associated with a series of known operations that constitute a calibration procedure 150A. The y-axis may represent, for example, measured beam current or, alternatively, spot beam scan speed. The x-axis represents time. A series of reference operations are indicated in the calibration procedure 150A by numbers Op1 through Op9. A selected subset group of the reference operations of FIG. 1A, including at least operations Op1, Op3, Op5, Op6, Op7, Op8, and Op9, may be performed in accordance with an embodiment of the present disclosure. The sum of all of the operations shown in FIG. 1A, including operations Op1 through Op9, may be considered to constitute a reference calibration procedure.

[0015] In operation Op1, the SpotBP procedure is performed to obtain two metrics required for uniformity tuning: BeamCenter and HalfWidth. These parameters are used to determine how far the (electrostatically) scanned spot beam is scanned to the inner "right" side of the wafer and the outer "left" side of the wafer before folding back. Once the horizontal scan "fold back" position is determined, the standard calibration procedure outlined in calibration procedure 150A does not employ the metrics (including geometry) of the SpotBP measurement for the remainder of the calibration procedure.

[0016] In different implementations, the SpotBP measurement can be performed by relative scanning of the sensor across a stationary beam, or by relative scanning of the spot beam across a stationary sensor at a slow beam scanning rate. In operation Op1a, the spot beam profile is measured by scanning the profiler Faraday cup sensor across the undeflected stationary spot beam. This operation can take approximately 12 seconds, and the slow spot profile SpotBP SlowIn the Op1b operation, the profiler Faraday cup sensor remains stationary at the center of the wafer plane at 0 mm, and the spot beam is swept across the profiler Faraday cup sensor several times, such as 16 times, to obtain an average current response. When this beam sweep response is transformed from a time-domain current response to a position-domain current response, the result is SpotBP Slow This behavior of Op1b is closely similar to the fast spot profile SpotBP. Fast This is sometimes called CalBP and can take approximately 3 seconds. Predicted This method for creating a spot beam is called SpotBP. Slow or SpotBP Fast For simplicity, we will assume that this spot beam measurement was performed using either CalBP or Predicted When explaining how to create a SpotBP Slow or SpotBP Fast The total integrated current of SpotBP (which results in the uniform density estimate of 151) is not used in calibration procedure 150A. However, the total integrated current is used in embodiments of calibration procedures 150b and 150C described later.

[0017] In operation Op3, the horizontal and vertical angles of the scanned spot beam are measured and tuned. These angle measurements are not used in the uniformity tune routine operations consisting of operations Op4 to Op9.

[0018] In operation Op5, the uniformity tune routine calculates the linear scanned beam profile ScannedBP Linear Start by generating and measuring ScannedBP. Linearis generated by scanning the spot ion beam over a predetermined horizontal scan distance (determined in act 1) at a constant velocity. The scan velocity of the spot beam is represented by curve 154a. ScannedBP Linear A subsequent measurement of can take approximately 12 seconds to perform, as shown. The resulting measured beam current density is shown in curve 154B. As shown, while the scan speed (curve 154a) remains a constant value, during the time interval the measured spot beam current exhibits several fluctuations in beam density corresponding to different positions. This ScannedBP Linear is the dip calibration spot profile CalBP in operation Op7. Dip is used to obtain

[0019] Before describing Op6, a definition of μ-tilt (microtilt) is provided. The ion beam is electrostatically scanned horizontally at a high frequency (approximately 1 kHz) over a predetermined horizontal scan distance that ensures the beam completely clears the wafer's edge and side faradies before the electrostatic scan turns the beam around. This horizontal scan distance is determined by several factors, including the beam width, and is typically between 350 mm and 600 mm for a 300 mm wafer. To fill in and "flatten" beam density non-uniformities across the wafer location, the beam scanning system must be able to speed up and slow down the scan speed to smooth out beam density "bumps" and "dips," respectively. To track where and how much the beam scan speed is changed, the horizontal scan distance (e.g., 400 mm) is divided into a fixed number (e.g., 30) of discrete speed change steps, where each step specifies the desired speed of the beam at that location. In this example, each μ-gradient is 13.33 mm wide (400 mm scan distance / 30 speed change locations). For the remainder of this specification, μ-gradients may be referred to as micro-gradients or u-gradients, gradient pitches, or gradients. This series of 30 μ-gradient beam velocities is sent to the beam scanner electronics, which converts it into a series of electrostatic scan velocities (positive mm to negative mm) that constitute a single right-to-left scan of the ion beam across the horizontal scan distance. When the scanner reverses direction, it scans using a mirror image of this μ-gradient waveform, such that the left-to-right scan velocities overlap with the right-to-left scan velocities. There is a "matching circuit" electronic delay between when the μ-gradient rate change is sent to the scanner system (with this 30-point array) and when that μ-gradient rate change actually occurs. This delay, and how it affects embodiments, is taken into account and will be discussed later.

[0020] In operation Op6, another scanned profile (curve 156b) is taken during which the velocity of the scanned beam is increased by 2x (curve 156a) over a distance (μ slope width) of about 10-15 mm at the center of the wafer surface. In other words, over a small portion of the scan length (about 400 mm total), the spot beam scan is deliberately accelerated by a factor of 2. This operation is called the dip-calibrated scanned profile ScannedBP. Dip which may also take approximately 12 seconds to execute.

[0021] In operation Op7, the so-called dip calibration spot profile CalBP Dip ScannedBP Linear (Curve 154b) to ScannedBP Dip (curve 156b). Based on this, the uniformity tune routine captured the effect of an intentionally reduced beam density that occurs when the spot beam scan speed is increased by 2x over a specific distance (μ ramp width). This information is the central piece of information the uniformity tune routine needs to generate the required overall uniform beam density before wafer implantation begins. The uniformity tune routine now "knows" how much to change the spot beam speed as it is scanned in order to "fill in" beam density dips and "flatten" beam density bumps to create a scanned ion beam of uniform density.

[0022] In operation Op8, the first adjusted scanned profile ScannedBP Adjusted is taken (curve 158b). This behavior is the result of a first guess in the tuning routine as to how the scanned spot beam speed should be varied over the horizontal spot beam scan distance (curve 158a) to make the ion beam current density uniform across the wafer surface. AdjustedNote that the operation involves adjusting the spot beam scan speed as shown by curve 158A, rather than applying a uniform scan speed to the spot beam (curve 154a). Thus, the scan speed pattern of the spot beam is ScannedBP Linear This should provide the correct compensation to adjust for the beam current non-uniformity measured in operation Op5 using curve V158b. At the same time, the beam current density is measured as shown by curve V158b. As can be seen, there are still some "dips" and "bumps" in the beam current density that need to be further smoothed out in operation Op8. The beam tuning routine in operation Op9 fine-tunes the variations in scanned beam velocity (curve V160a) to smooth out these residual variations in beam density (curve V160b), resulting in the second Op9 ScannedBP Adjusted Each ScannedBP is measured at Adjusted involves first generating a scanned beam waveform with an adjustment to the scan rate, and then measuring the resulting beam density using a mechanical left-to-right scan of the Faraday detector to verify that the measured current density along the horizontal beam scan axis passes the uniformity "flatness" specification. When the overall uniformity falls below an acceptable uniformity sigma, the uniformity tune routine is complete and wafer implantation can begin. In FIG. 1A, operation Op8 is shown repeated in a single instance (Op9) resulting in what may be considered acceptable beam uniformity. The change in the calculated sigma value of each scanned profile measurement is shown in the update to line 161. This is the measured sigma value, and the measured sigma value is then calculated for each ScannedBP to verify that the measured sigma value falls below the limit before wafer implantation can start. Adjusted and then compared with the specification limits.

[0023] In various embodiments of the present disclosure, the beam calibration routine outlined in FIG. 1A includes, among other things, the approximately 12-second ScannedBP of calibration procedure 150A (FIG. 1A). DipThe calibration routine may be modified by performing an additional new operation (shown in calibration procedure 150b, FIG. 1B) that provides the ability to omit operation Op6. As a result, using a calibration routine referred to herein as a Predicted Calibration Spot Profile (PCSP) routine, the overall calibration time may be significantly reduced, by up to about 12 seconds using the example of calibration procedure 150B of FIG. 1B. By way of example, in the modified calibration routine of this embodiment (outlined by calibration procedure 150B), operation Op1 outlined above is still performed to measure the beam center and HalfWidth to determine the horizontal scan distance and fold position of the scanned beam. However, the CalBP Predicted and ScannedBP for PSCP routine. Dip The shape and integral current (area) of this spot profile SpotBP are also used in subsequent operations to skip the operation Op3 for measuring and adjusting the horizontal and vertical beam angles. After operation Op3, the uniformity tune portion of the PCSP routine is performed by operation Op5 (ScannedBP) described above with respect to FIG. 1B. Linear ) execution.

[0024] Unlike the example in Figure 1A, operation Op6 ScannedBP Dip is omitted in the PCSP routine of FIG. 1B, saving nearly 12 seconds of calibration time. This time savings may correspond to approximately a 13% improvement in the overall tuning routine. In the approach according to the present embodiment, in a modified version of operation Op7, the adjusted waveform is converted to a predicted calibration spot profile CalBP, which is described in more detail below. Predicted This ScannedBP is created by using Dip is skipped, the measured effect of increasing the beam velocity by 2x over the μ gradient width (approximately 10-15 mm) is unknown.

[0025] To compensate for not directly measuring the effect of increasing the beam velocity by 2X, for example, the PCSP routine uses CalBP Predicted and the profile is created and Dip According to various embodiments of the present disclosure, the PCSP routine is based on most or all of the following measurements: A listing of measurements that may form part of the PCSP routine is provided below, along with some non-limiting ranges for the parameters used in these measurements: ●Stationary SpotBP shape (HalfWidth), center and integral current (area) μ gradient width (e.g., 10 to 15 mm) and position ●HorizontalScanDistance (for example, 400mm~600mm) ●Beam scanning time (for example, 400 μsec to 2,000 μsec) ● The speed of the mechanical profiler (for example, 32 mm / s or 96 mm / s) Doze controller matching circuit delay for μ-ramp rate change (e.g., 6 μsec)

[0026] This CalBP Predicted The creation of the ScannedBP is performed in Op 2 of calibration procedure 150B (FIG. 1B) and is described below. Note that all of these measurements are collected before the Uniformity Tune routine portion of PCSP begins. Therefore, according to an embodiment of the present disclosure, PCSP uniformity calibration is performed using the ScannedBP Linear Immediately after (operation Op5) is completed, the first ScannedBP Adjusted You can start with:

[0027] CalBP Predicted and ScannedBP Linear After obtaining one or more ScannedBPs, Adjusted is taken as described in the standard uniformity tuning operations Op8 and Op9. The additional Op6 ScannedBP outlined in FIG. 1A DipOp7 CalBP created using Dip Instead of using ScannedBP, the PCSP uniformity routine Dip 1B (including Op1, Op2, Op3, Op5, Op8, and Op9 of calibration procedure 150B) to skip across the wafer and make any necessary changes to the velocity of the spot beam as it is scanned to achieve a uniform beam density across the wafer surface. Predicted Use.

[0028] It should be noted that the above-described embodiments highlight the procedure for spot beam scanning calibration when a new strategy is being implemented, such as for the first time. In these scenarios, the operations and sub-operations generally described above, including the general operations Op1 through Op9, are implemented. In particular, the first scanned profile for a brand new strategy is always the ScannedBP profile described above in FIGS. 1A and 1B. Linear According to various embodiments of the present disclosure, once the recipe is tuned up (the calibration described above is performed), the recipe saves the μ-tilt (curve 160A) beam velocity waveform in the recipe for future use. Those μ-tilts that achieved uniform beam density (reflected in operation Op9) can be saved in the recipe as an array (e.g., ranging from 30 to 100) of distinct μ-tilts. These μ-tilts tell the ion beam control system which beam scan speed changes to apply at specific locations along the wafer surface to achieve uniform beam density.

[0029] According to embodiments of the present disclosure, when an ion beam implantation recipe is re-downloaded (such as immediately after an implant procedure or in the following week), the calibration routine automatically recognizes that the ion beam implantation recipe has been previously calibrated, generally according to the procedures described above. In these embodiments, instead of newly implementing all of operations Op1, Op2, Op3, Op5, Op8, and Op9 (and sub-operations therein) (of calibration procedure 150b), the recognition that a previous calibration has been performed for the recipe triggers the calibration routine to execute an even faster set of operations (Op1, Op2, Op3, Op4, Op8, Op9) shown in calibration procedure 150C of FIG. 1C. For example, the calibration routine may ignore the μ-tilt obtained during the previous (initial) spot beam scan calibration and execute a new constant speed ScannedBP. Linear Rather than starting from scratch (operation Op5), the calibration routine instead uses ScannedBP Recipe Implement (Operation Op4).

[0030] ScannedBP Recipe To create the uniformity profile, the calibration routine retrieves the downloaded μ-tilt array (e.g., 30-100 μ-tilt) (curve 152a), initiates scanning of the spot beam accordingly, and then implements the mechanical profile of that scanned spot beam (curve 152b) using a profile detector, such as a profile Faraday detector. This operation again consumes several seconds, such as 12 seconds. If the scanned spot beam has not changed significantly since the last spot beam calibration was performed, the μ-tilt from the recipe may still produce a beam density (curve 152b) below the uniformity specification limit. If so, no further scanned beam profile creation is necessary, and wafer ion implantation using that recipe may begin or resume.

[0031] Additionally, ScannedBP (implemented as operation Op4) Recipe If results in a beam density uniformity that exceeds the specification but is not "too bad", the PCSP routine will still use ScannedBP (starting from zero).Linear ScannedBP instead of curves Recipe A reduced calibration operation using the curve may be initiated.

[0032] The determination of what results above the specification are acceptable or "not too bad" may be made according to the following considerations: Often, a uniformity beam density sigma specification may be set at 0.3% to 0.5% ("sigma" is a statistical measurement of the "flatness" of the measured beam density across the wafer surface (as measured by a mechanically scanned profile detector, such as a Faraday cup detector). Thus, in one embodiment, if sigma is less than 0.5% above the specification, the ScannedBP Recipe (Curve 152b) can be used. On the other hand, if sigma is more than 0.5% above the specification limit, ScannedBP Recipe is ignored and the spot beam calibration routine uses ScannedBP Linear Start from scratch using

[0033] In summary, according to an embodiment of the present disclosure, the spot beam calibration routine is Recipe When implementing the above, the operations in calibration procedure 150C (Op5, Op6, and Op7) may all be omitted during the performance of the reduced spot beam calibration routine. This omission of operations Op5, Op6, and Op7 saves a significant amount of calibration time, such as 24 seconds using the above example. This allows the reduced spot beam calibration routine to proceed in the following order of operations: Op1, Op2, Op3, Op4, Op8, Op9. CalBP Predicted can be created anywhere between operations Op1 and Op4, so the routine can immediately start making adjustments and measuring them (operation Op8). The calibration procedure 150C shown in FIG. 1C highlights the differences in the implementation of the calibration procedure according to embodiments of the present disclosure. A basic calibration may implement the operations Op1 through Op9 shown, and in a first implementation of the PCSP routine for a new strategy, subsequent implementations may implement the operations Op4, Op5, and Op6. RecipeHowever, operations Op5, Op6 and Op7 may be omitted.

[0034] The goal of the PCSP method of the present embodiment is to use the CalBP uniformity tuning convergence routine. Predicted The following operations convert SpotBP (Figure 2A) and CalBP Dip (Figure 2B) highlights the major differences between SpotBP and CalBP. Dip The conversion to CalBP must account for all of these differences. Predicted The overall shape of the CalBP Predicted However, since it is a convolution of the SpotBP shape when its scanned velocity is increased by 2x over a distance of about 10-15 mm, it strongly resembles the shape of SpotBP.

[0035] Referring now to Figure 2A, a composite illustration is shown including menu items and graphical representations of signals associated with SpotBP. Referring also to Figure 2B, a composite illustration is shown including menu items and graphical representations of signals associated with CalBP. Dip A composite illustration is shown containing a graphical representation of the signal associated with the SpotBP. In these graphs, the x-axis plots position along the wafer surface, and the y-axis plots beam current. In these cases, the beam current exhibits a peak shape near the wafer center at 0 mm. The first difference to take into account is the difference in size of the two shapes. SpotBP is 4e -5 While it has a peak of 7.4e -7 CalBP of A Dip The peak is much smaller because it only captures a small fraction of the total beam current. Generating the necessary scalar for this magnitude conversion will be explained later.

[0036] The second major difference is the width of the two different spot profiles. DipThe CalBP has a wider width because the profile is the result of a convolution of the SpotBP shape over a 2x speed-up distance of approximately 10-15 mm during the horizontal scan. Dip The width is comparable to the SpotBP width when the 2x speed-up distance is very small. The third major difference is the horizontal center of the spot profile. Dip The center is the scanned beam, CalBP Dip The "dip" used to create the CalBP is accelerated by 2x, shifted to the right or left of the SpotBP center depending on the location of the μ gradient. If the 2x up-location of 10-15mm was symmetric about 0mm, the CalBP Dip The center will be very close to the SpotBP center.

[0037] Figure 3 shows the standard measurement of CalBP. Dip (curve 306) (operation Op7, see also FIG. 1) and predicted CalBP Predicted Curve 302 shows a comparison with ScannedBP (at constant beam speed) (curve 308). Linear (Operation Op5, see also FIG. 1A). Curve 304 is the ScannedBP Dip (Speed ​​up by 2x over one μ gradient at 0 mm) (Operation Op6, see also Figure 1). Dip ScannedBP Linear ScannedBP Dip As can be seen, the measured CalBP Dip and predicted CalBP Predicted (Curve 306 and Curve 308) closely overlap each other, and the close correspondence indicates that the calculation method (described later) Dip Demonstrate that you can accurately predict what was

[0038] According to an embodiment of the present disclosure, the predicted CalBP in FIG. Predicted (Curve 308) is generally derived as explained in the following sequence: a) In the existing approach, as described above, after measuring SpotBP, the next sub-action in setting up a uniform scanned beam is to measure ScannedBP Linear The first step is to record the ScannedBP. Dip followed by ScannedBP Dip is obtained by increasing one μ-tilt over a defined pitch interval. μ-tilt is a small distance, about 10-15 mm (typically centered near 0 mm), over which the scanned beam velocity is increased by 2x to create an intentional beam density "dip" in the center of the wafer surface. b) The difference between these two profiles is the CalBP Dip is. c) However, this CalBP Predicted can actually be predicted from the (measured) SpotBP and the amplitude and location of the perturbed gradient. Dip Recording your CalBP Predicted Instead, CalBP is not required to determine Predicted can be obtained as a convolution of SpotBP over a μ-gradient velocity change distance of approximately 10-15 mm.

[0039] According to various embodiments of the present disclosure, FIGS. 4-8C show SpotBP, CalBP, Predicted Highlight the actions (and sub-actions) involved in the conversion from SpotBP to CalBP Predicted Sub-operations 4 through 27 (SO4 through SO27) for the conversion to are all completed in the Op2 calculation and take a total of only a fraction of a second to execute. Referring to Figure 4, a series of curves is shown, where curve 402 represents SpotBP and curve 404 represents the "ideal" calibration spot beam profile CalBP Ideal , and curve 406 represents the actual calibration spot profile CalBP DipThe profile is shown as current (y-axis, meaning vertical axis) as a function of position along the wafer surface (x-axis, meaning horizontal axis in the figure). The current scale for SpotBP (left y-axis) is Ideal About and Actual CalBP Dip Note that the current scale (right y-axis) for CalBP is almost two orders of magnitude larger than that for SpotBP. Dip The degree of shifting of the relative positions along the wafer surface of the is exaggerated for clarity of illustration, so that Figure 4 provides an overview of the results of the various sub-actions (represented by SO1) in subsequent figures.

[0040] FIG. 5A shows that SpotBP (curve 402) is normalized to CalBP when magnitude is normalized. Ideal The so-called hypertrophy spot profile SpotBP has a shape (curve 501) that more closely resembles (curve 404). Fat 4 shows a qualitative illustration (labeled SO2) of how much "fat" should be added using the sub-action. Also, SpotBP (curve 402) and SpotBP Fat The current values ​​for (curve 501) are the current values ​​and CalBP Ideal (curve 404), where the latter profile is represented by the right-hand Y-axis.

[0041] 5B, the leftmost slice shows a bird's-eye view (V3) of SpotBP (curve 402), where SpotBP has a center location of 6 mm. Note that the wafer plane direction has been shifted to the vertical axis in this view, and the location of the SpotBP center is now pointed along this vertical axis.

[0042] In particular, the operation of FIG. 5B is Fat 5 illustrates the augmentation of SpotBP using a convolution routine to create (curve 501). In sub-operation SO11, the routine takes into account known uniformity calibration procedures and calculates CalBP. DipFirst, increase the scanned beam velocity by 2x over a given distance (e.g., 9.32 mm) (μ gradient width), and then use the previously obtained (constant scan velocity) ScannedBP Linear This "dip" from ScannedBP Dip This 9.32mm / 2x speed-up of the spot beam scan is generally not performed strictly symmetrically around the wafer center position at 0mm, so the actual start and end positions (-2.23mm and 7.09mm in this example) must be taken into account as well.

[0043] Moreover, in actual spot beam scanning, the beam is scanned back and forth from left to right and right to left, meaning that scanning is performed to scan the beam along the wafer surface (y-axis in FIG. 5B; it will be understood that the terms "right to left" or "left to right" in this context are represented by bottom to top or top to bottom, as shown in FIG. 5B and subsequent FIG. 6B). In this ideal case, sub-operation SO4 assumes a 9.32 mm 2x speedup when the spot beam scans from left to right at the exact same spot as when the spot beam scans from right to left. Note: FIGS. 6A and 6B show that this assumption is not true in general, but for the time being, this ideal example is assumed.

[0044] To simulate how SpotBP (curve 402) becomes "thickened" during a 2x speed-up over 9.32 mm going from left (negative mm) to right (positive mm), in sub-operation SO6 SpotBP is shifted backward so that the non-deflected location for SpotBP at 0 mm aligns with the start of the scan speed-up, which occurs at -2.23 mm.

[0045] In a subsequent sub-operation SO7, the two-dimensional (2D) array is filled so that this high-speed profile shape is stepped in suitable increments (0.1 mm increments in the example shown) over a distance of 9.32 mm (with small rounding errors at the end).

[0046] In the subsequent sub-operation SO8, to simulate how SpotBP becomes "thickened" during the 2x speed-up over 9.32 mm going from right (positive mm) to left (negative mm), the high-speed profile is shifted forward in sub-operation SO8 so that the non-deflected location for SpotBP at 0 mm is aligned with the end of the scan speed-up at 7.09 mm.

[0047] In sub-operation SO9, the 2D array continues to fill as this SpotBP shape is stepped in 0.1 mm or other suitable increments over a distance of 9.32 mm (with small rounding errors at the end).

[0048] At this junction, the 2D array was filled with many SpotBPs going from left to right in 0.01 mm increments (932 SpotBPs in the example of FIG. 5B), as well as many SpotBPs going from right to left (932 SpotBPs in the example of FIG. 5B). In sub-operation SO10, the currents from all profiles (1864 profiles in the particular example) were collected by the SpotBPs shown in the shaded portion of the rightmost strip in FIG. 5B. Fat (curve 501) are summed in 0.01 mm increments and then divided by 1,864. This "inflated" SpotBP Fat was normalized to contain the same amount of area (spot current) as the original SpotBP (curve 402).

[0049] As shown by sub-action SO11 in FIG. 5A, this SpotBP Fat (Curve 501) is still CalBP IdealNote that the width of the curve 404 does not match the width of the curve 404. According to embodiments of the present disclosure, another "fatten up" factor may be applied to generate the curve 404, as detailed in Figures 6A and 6B.

[0050] Referring now to Figures 6A and 6B, SpotBP Fat Further sub-operations are shown that can be applied to further thicken the delayed thickened spot beam profile SpotBP after these sub-operations (collectively shown as sub-operation SO12) are completed, as summarized in FIG. FatDelay (Curve 601) is Curve 404 CalBP Ideal In particular, as shown in Figure 6A, the width of SpotBP FatDelay The current scale (left y-axis) of the profile (curve 601) is the same as the current scale for SpotBP (curve 402).

[0051] Referring now to FIG. 6B, a series of additional sub-operations are illustrated that can be employed to account for control delays that can introduce detectable lag into the scan control. In sub-operation SO13, instead of starting the 2D array with SpotBP shifted back to −2.23 mm (as specified in sub-operation SO6), SpotBP can actually be shifted to start slightly further to the right (more positive) to more accurately account for delays introduced in the controller circuitry (called the dose controller matching circuitry). Similarly, the left-right terminology relative to the wafer plane maps to the up-down direction in the view of FIG. 6B. In existing ion implanters, dose controller electronics may be used that include an inherent delay (dose controller delay) on the order of microseconds—6 μs in the illustrated example—when the dose controller switches from an old scan rate to a new scan rate during a horizontal scan. This 6 μs delay results in a horizontal (wafer plane, shown vertically in FIG. 6B) shift in the spot beam's actual response that is proportional to how fast the spot beam is scanning.

[0052] In sub-operation S14, the horizontal (wafer plane) shift in the μ-tilt (beam velocity) change based on the dose controller matching circuit is determined. This shift can be determined as: Matching Circuit Delay (mm) = [Matching Circuit Delay (6 μSec) / BeamSweepTime] / HorizontalScanDistance. The 6.4 μsec "matching circuit" delay (the time from requesting a beam scan velocity change (μ-tilt) to when the μ-tilt beam scan velocity change actually occurs) is used to determine the horizontal (wafer plane) shift in the dose controller matching circuit. FatDelay (curve 601), where SpotBP FatDelay Included in the calculation, in various embodiments, this shift can span a range of about 1 mm to about 8 mm, depending on the beam sweep time and the horizontal scan distance employed to scan the spot beam.

[0053] In sub-operation SO15, to simulate how SpotBP "grew" during a 2x speed-up over 9.32 mm going from left (negative mm) to right (positive mm), the speed profile is shifted back so that the 0 mm undeflected location lines up with the beginning of the speed-up at -2.23 mm plus the matching circuit delay, which delay is 2.5 mm in the example of Figure 6B. This matching circuit delay portion is shown diagrammatically as a smaller rectangle adjacent to the larger scan rectangle.

[0054] In a subsequent sub-operation SO16, the 2D array is filled so that the SpotBP shapes are stepped in suitable increments, such as 0.1 mm increments, over a suitable distance, such as 9.32 mm (with small rounding errors at the end).

[0055] In sub-operation SO17, to simulate how the high speed profile becomes "thickened" during a 2x speed-up over 9.32 mm going from right (positive mm) to left (negative mm), the high speed profile is shifted forward so that the 0 mm undeflected location lines up with the end of the speed-up in the matching circuit delay, such as 7.09 mm, minus 2.5 mm in the example shown.

[0056] In sub-operation SO18, the 2D array continues to fill so that this SpotBP shape is stepped in suitable increments, such as 0.1 mm increments, over a suitable distance, such as 9.32 mm (with a small rounding error at the end).

[0057] In this junction, in the example of Figure 6B, the 2D array was filled with 932 SpotBPs going from left to right and 932 SpotBPs going from right to left in 0.01 mm increments. In run SO19, the currents from all 1,864 profiles (shown in the shaded portion of the rightmost strip in Figure 6B and shown as curve 601 in Figure 6B) were FatDelay To create the profile, the values ​​are summed in 0.01 mm increments and then divided by 1,864. This "bloated" SpotBP FatDelay was normalized to contain the same amount of area (spot current) as SpotBP. FatDelay also includes the matching circuit delay, so that SpotBP FatDelay CalBP Ideal (curve 404).

[0058] At this junction, SpotBP FatDelay (Curve 601) Width is CalBP Ideal (curve 404). Referring to FIG. 7A, in operation SO20, the area scalar CalBP Ideal CalBP with the same height as (curve 404) FatDelayArea(Curve 702) is applied to create the shape. After this scalar is applied, (CalBP FatDelayArea The predicted Cal spot shape (represented by curve 702) is shown in Figure 7A, using the same vertical current axis, and the CalBP Ideal It should closely overlap (curve 404).

[0059] Figure 7B shows that this area scalar is calculated by SpotBP in the following manner: scalar = [μ gradient width] / HorizontalScanDistance / 2. FatDelay (Curve 601) depicts the sub-action SO21, which is applied by multiplying each current element in the array. This scalar can be geometrically explained by tracking how the density of the spot beam changes as it is scanned in subsequent steps, as shown in FIG. 7C.

[0060] FIG. 7C is a composite illustration depicting a top view of substrate 710 and a graph showing beam current (Y or vertical axis) as a function of position along the wafer plane (x-axis or horizontal axis) of substrate 710. Note that the scale in mm along the x-axis is the same for substrate 710 as well as the depiction of SpotBP (reference number "402" is used to indicate that SpotBP in FIG. 7C corresponds to curve 402), shown as current as a function of horizontal position along the wafer plane or x-axis. In the example shown, substrate 710 is a 300 mm wafer, where view V22 shows the original SpotBP ("402") with shading and the horizontal position of SpotBP ("402") relative to substrate 710.

[0061] Referring now to FIG. 7D, another composite illustration is shown including a top view of substrate 710. The scan direction along the wafer surface for the spot beam in this view is also right to left in the illustration. The scan distance of an exemplary scanning routine is indicated by a double-headed arrow and, as shown, may be 426 mm to process a 300 mm wafer. In FIG. 7D, in sub-operation SO23, the beam density is spread in an ideal "rectangle" as the spot beam is scanned over a HorizontalScanDistance of 426 mm. The total area of ​​the linear scanned profile (rectangle 740) is the same as the SpotBP area (area 730, see FIG. 7C) = 2.99e-3 (A x mm). The scanned BP Linear Note that the peak is equal to SpotBP area (area 730) / scanned distance (426 mm) = 7.02e-6(A).

[0062] Referring now to Figure 7E, this figure shows the CalBP Ideal Area and ScannedBP Linear 10 shows a schematic representation of the components of sub-operation 24 where the ratio to the total area is calculated. ScannedBP when the spot beam scan rate is sped up by 2x over a μ-tilt distance of 16 mm. Linear CalBP in Ideal The relative area of ​​the "dip" is shown as rectangle 750 (in this example, the 2x speed-up μ-slope width is symmetric about 0 mm and extends from -8 mm to 8 mm). When the spot beam scan rate is speeded up by 2x, the density of the beam is reduced by 1 / 2, so the height of the "dip" is 1 / 2 the height of the linear scanned profile height. The width of the "dip" rectangle is 16 mm. Using these rectangle dimensions in sub-operation SO24, the CalBP corresponding to rectangle 750 is Ideal "Dip" area and ScannedBP Linear Ratio to the entire area = CalBP Ideal (Area ratio) = [μ gradient width / HorizontalScanDistance] / 2 = [16mm / 426mm] / 2 = 0.0188.Ideal The "Dip" area is the total ScannedBP (the area is the total integrated SpotBP current) Linear This is only 1.88% of the entire area.

[0063] Referring now to FIG. 8A, a series of curves showing beam current as a function of position are shown, where the area-scaled delayed hypertrophied spot beam profile CalBP FatDelayArea (Curve 702) has been constructed, and its profile is the "ideal" CalBP. Ideal (curve 404). Up until this junction, the calibration routine Ideal (Curve 404). This CalBP Ideal The shape can be achieved when a sensor such as a Faraday cup is profiled across the scanned spot beam at a very slow speed (to obtain linear and dip scanned profiles). Ideal The coefficient that modifies the ideal shape of the calibration spot profile CalBP is called the profile velocity transient. Predicted The prediction of may take this transient response into account.

[0064] The beam control system (ScannedBP Linear , ScannedBP Dip and ScannedBP AdjustedWhen measuring the scanned spot beam current density across the wafer surface using a current detector, such as a moving profiler Faraday cup (as is done for a set of ion beams), the detected signal from the detector is filtered by a detector filter, such as a low-pass filter to remove and average out high frequency noise created by the high speed electrostatic scanning (recall that the scan rate of the scanned spot beam is often in the range of several kilohertz). In current ion beam control systems, the low-pass filter may be a 3 Hz single-pole low-pass filter. Because the filter response is a slow transient response, the low-pass filter adjusts the CalBP according to the mechanical profile speed. Ideal Filter ScannedBP Dip The "dip" in the beam spot profile is measured as the profiler progresses from left (negative) to right (positive) across the wafer surface. For illustrative purposes, if the profiler Faraday cup detector is set to move very slowly (approximately 4 mm / sec), the transient response of the 3 Hz filter in the Faraday cup detector electronics will have time to charge and discharge as the Faraday cup passes across a 2x reduction (dip) in beam density. This slow Faraday moving situation will produce an "ideal" calibration spot profile CalBP, as shown by sub-action SO26. Ideal (curve 404).

[0065] However, profiling a single scanned beam profiled at 4 mm / sec takes almost 8x longer to complete the profile (96 seconds vs. 12 seconds), a situation that causes an unacceptable increase in calibration time. To achieve the target time required to collect the profile of approximately 12 seconds, the profiler detector speed is set to 32 mm / sec. When the profiler detector speed is increased to 32 mm / sec, the profiler detector is swept more rapidly by the 2x dip in beam current, and the transient response of the 3 Hz filter may not be able to keep up with the change in beam current. Therefore, in sub-operation 27, a profile speed transient response factor based on a 32 mm / sec profile speed is added to the final CalBP. Predicted To create (curve 802), CalBP Ideal (curve 404). Because the profiler detector measures the beam current as it moves from left to right, this curve is shifted to the right, in this example, reducing the magnitude of the current and stretching it horizontally along the wafer surface. This final CalBP Predicted (Curve 802) is the original CalBP Dip It should overlap very closely with (curve 406).

[0066] Referring to Figure 8B, CalBP Predicted To finally generate (curve 802), CalBP FatDelayArea In (curve 702) is shown a schematic representation of the Faraday cup filter transient response that should be applied (as indicated by sub-action SO28). This example assumes that the profiler Faraday cup scan speed is increased from an ideal speed of 4 mm / sec to a practical speed of 32 mm / sec. Note that according to other embodiments, the profiler detector speed can be set even faster, at 96 mm / sec. In such a case, sub-action SO28 would further increase the CalBP Predicted (curve 802) and extending its width, further to the right in FIG. 8A. Predicted Shift the position of (curve 802).

[0067] Figure 8C shows the results of consecutive ScannedBPs. Linear and ScannedBP Dip The effect of increasing the profile detector speed on the profiles and their resulting calibration spot profiles CalBP Dip In particular, a series of calibration spot profiles CalBP at different profile speeds for the same boron 220 kV beam. Dip ScannedBP Linear and ScannedBP Dip The leftmost highest Cal spot profile, CalBP, was obtained based on a profiler detector speed of 8 mm / s to collect the Dip , where (CalBP Dip =ScannedBP Linear -ScannedBP Dip ) When the profiler is moved at 128 mm / s in this example, the shortest and most rightward shifted CalBP Dip is measured, scanned profile filtering is turned off. According to an embodiment of the present disclosure, this transient response is therefore modeled according to the speed of the profiler detector.

[0068] FIG. 9A depicts a top view in block form of a beamline ion implanter, designated as ion implanter 100, in accordance with various embodiments of the present disclosure. The ion implanter 100 includes an ion source 102 configured to generate an ion beam 104. The ion beam 104 may be provided as a spot beam scanned along a direction, such as the X direction. In the convention used herein, the Z direction refers to the direction of an axis parallel to the central ray trajectory of the ion beam 104. Thus, the absolute orientation of the Z direction as well as the X direction may vary at different points within the depicted ion implanter 100, where the X direction is perpendicular to the Z direction. The ion beam 104 may pass through an analyzing magnet 106, a mass resolving slit 108, and a collimator 112 before impinging on a substrate 116 disposed on a substrate stage 114. The substrate stage 114 may, in some embodiments, be configured to scan the substrate 116 at least along the Y direction. In the example shown in FIG. 1, the ion implanter 100 includes a beam scanner 110. When the ion beam 104 is provided as a spot beam, the beam scanner 110 may scan the ion beam 104 along the X direction, resulting in a scanned ion beam that is scanned at the substrate, also along the X direction. The width of the resulting scanned spot beam may correspond to the width W of the substrate 116.

[0069] In various non-limiting embodiments, the ion implanter 100 may be configured to deliver an ion beam for "low" or "medium" energy ion implantation, such as a voltage range of 1 kV to 300 kV, corresponding to an implant energy range of 1 keV to 300 keV for singly charged ions. As discussed below, the scanning of the ion beam provided to the substrate 116 may be adjusted according to calibration measurements prior to substrate ion implantation using the scanned ion beam.

[0070] The ion implanter 100 further includes a current detector 118, such as a closed-loop current detector, particularly a closed-loop Faraday current detector (CLF), for monitoring the beam current provided to the substrate 116. The current detector 118 is disposed to intercept the ion beam 104 and may be configured to record the beam current of the ion beam 104 during the various calibration operations discussed above.

[0071] The ion implanter 100 also includes a beam calibration component 120. The beam calibration component 120 may be coupled to the beam scanner 110 as well as the current detector 118. The beam calibration component 120 may be coupled to one or more components for adjusting the scanning of the ion beam 104 to provide a more uniform ion implantation into the substrate 116 as a result of the calibration procedure. The beam calibration component 120 may generate a calibrated spot profile CalBP, as described in the example above. Predicted A calibrated spot profile, CalBP, based on the application of various beam measurements to predict Predicted and for determining the application of routines based on these measurements. Predicted may generate an adjustment signal to adjust the scanning of the ion beam 104 based on the beam calibration signal. In some cases, the logic of the beam calibration component 120 may be implemented in a combination of software and hardware or firmware. In some examples, the beam calibration component 120 includes a controller 120-A, and a CalBP. Predicted The embodiment may include circuitry such as memory 120-B coupled to software for executing instructions for adjusting the scanning of the ion beam 104 based on the determination of the parameter . The embodiments are not limited in this context.

[0072] 9B, there is shown a block diagram of memory 120-B including a spot beam calibration routine 902. The spot calibration routine 902 may store instructions for implementing the operations described above, including operations Op1, Op3, Op5, Op8, and Op9 generally described above, and sub-operations SO4-SO31, among others. These operations of the spot beam calibration routine 902 may be implemented by logic either in stand-alone form or resident in electronic processing circuitry such as controller 120-A.

[0073] 10 illustrates a process flow 1000 according to an embodiment of the present disclosure. In block 1010, a spot beam profile SpotBP is received for a spot ion beam. In one embodiment, SpotBP is measured by scanning a profiler Faraday cup detector across an undeflected stationary spot beam. In another embodiment, SpotBP is obtained when the profiler Faraday cup sensor remains stationary at the center of the wafer plane at 0 mm and the spot beam is swept across the profiler Faraday cup sensor several times.

[0074] At block 1020, the calculated CalBP Predicted may be determined by implementing a so-called predicted calibration spot profile (PCSP) routine, generally described with respect to FIGS. 4-8C. Among other things, the PCSP routine, as well as any of the above-described routines, may be stored in a computer-readable medium, such as a memory or memory unit, for execution as instructions by components of a computer. These instructions may be implemented using electronic processing circuitry, which may be referred to as a controller, processor, or electronic processor. Among other things, the PCSP routine may be implemented using a controller embodied in one or more electronic processors, for example, to perform the operations detailed in FIGS. 4-8C.

[0075] In particular embodiments, the PCSP routines may include:

[0076] SpotBP shape and location,

[0077] horizontal beam scanning distance,

[0078] The size and location of μ-gradients commonly used to create beam density "dips";

[0079] Matching circuit delays in beam scanning electronics,

[0080] Profiler Faraday electronics and mechanical motion velocity filter transient response artifacts.

[0081] As previously mentioned, sub-operation 4-27 (FIGS. 4-8C) calculates CalBP. Predicted are all completed in the Op2 computation, consuming a total of just a fraction of a second.

[0082] In block 1030, a linear scanned beam profile ScannedBP is calculated. Linear is received. Linear can be generated when the current is measured while the spot ion beam of block 1010 is scanned at a constant velocity over a predetermined horizontal scan distance. The scan velocity of the spot beam is represented by curve 404. This ScannedBP Linear may take several seconds to run, such as about 12 seconds.

[0083] In block 1040, ScannedBP is used to make any necessary changes to the velocity of the spot beam as it is scanned to achieve a uniform beam density across the wafer surface. Linear and CalBP Predicted Based on the adjusted scanned profile ScannedBP Adjusted is taken for the spot beam.

[0084] This embodiment provides at least the following advantages: First, by following the operations listed above, SpotBP generates a dip calibration spot profile CalBP. Dip Accurately predict the shape, size and location of the Predicted ) can be used to obtain the dip-calibrated scanned profile (ScannedBP). Scanned By eliminating the need to perform a tune-time test, this approach provides significant tune-time improvements of up to 13% when approaching beam tune times for medium current ion implanters.

[0085] The present disclosure should not be limited in scope by the specific embodiments described herein. Indeed, various other embodiments of and modifications to the present disclosure, in addition to those described herein, will be apparent to those skilled in the art from the foregoing description and the accompanying drawings. Accordingly, such other embodiments and modifications are intended to fall within the scope of the present disclosure. Moreover, while the present disclosure has been described herein in the context of particular implementations in particular environments for particular purposes, those skilled in the art will recognize that the usefulness is not limited thereto, and that the present disclosure may be beneficially implemented in any number of environments for any number of purposes. Accordingly, the claims set forth below should be construed in light of the full breadth and spirit of the present disclosure as described herein.

Claims

1. receiving a spot beam profile for a spot ion beam; receiving a linear scanned beam profile for the spot ion beam; generating a calculated calibration spot profile based on the spot beam profile and the linear scanned beam profile; implementing an adjusted scanned profile for the spot ion beam based on the calculated calibration spot profile; A method comprising:

2. The method of claim 1 , wherein generating the calculated calibration spot profile comprises generating an enlarged spot beam profile by performing a convolution operation on the spot beam profile.

3. 3. The method of claim 2, wherein generating the calculated calibration spot profile further comprises generating a delayed enlarged spot beam profile by adjusting the enlarged spot beam profile by a dose controller delay of a controller used to control the spot ion beam.

4. 4. The method of claim 3, wherein generating the calculated calibration spot profile further comprises applying an area scalar to the delay hypertrophy spot beam profile to generate an area-scaled delay hypertrophy spot beam profile, wherein the area scalar is determined from a ratio of an area of ​​an ideal calibration spot beam profile to an area of ​​the linear scanned beam profile.

5. 5. The method of claim 4, wherein generating the calculated calibration spot profile further comprises applying a profile speed transient response factor to the area-scaled delay thickened spot beam profile based on a filter response for a detector filter used to generate the linear scanned beam profile.

6. The method of claim 1 , wherein the spot beam profile is measured by scanning a current detector across an undeflected stationary spot beam.

7. The method of claim 1 , wherein the linear scanned beam profile is generated by scanning the spot ion beam at a constant velocity over a predetermined horizontal scan distance.

8. a beam scanner for scanning the spot ion beam relative to the substrate; a detector for measuring the current of the spot ion beam; A beam calibration component comprising a controller and a memory, said memory comprising: receiving a spot beam profile for the spot ion beam; receiving a linear scanned beam profile of the spot ion beam; generating a calculated calibration spot profile based on the spot beam profile and the linear scanned beam profile; implementing an adjusted scanned profile for the spot ion beam based on the calculated calibration spot profile; a beam calibration component comprising a calibration routine operable on the controller to:

1. An apparatus for controlling the scanning of an ion beam, comprising:

9. 9. The apparatus of claim 8, wherein the calibration routine is operable on the controller to generate the calculated calibration spot profile by performing a convolution operation on the spot beam profile to generate an enlarged spot beam profile.

10. 10. The apparatus of claim 9, wherein the calibration routine is operable on the controller to generate the calculated calibration spot profile by further generating a delayed enlarged spot beam profile by adjusting the enlarged spot beam profile by a dose controller delay of a dose controller used to control the spot ion beam.

11. 11. The apparatus of claim 10, wherein the calibration routine is operable on the controller to generate the calculated calibration spot profile by further applying an area scalar to the delay enlarged spot beam profile to generate an area-scaled delay enlarged spot beam profile, wherein the area scalar is determined from a ratio of an area of ​​an ideal calibration spot beam profile to an area of ​​the linear scanned beam profile.

12. 12. The apparatus of claim 11, wherein the calibration routine is operable on the controller to generate the calculated calibration spot profile by further applying a profile speed transient response factor to the area-scaled delay thickened spot beam profile based on a filter response for a detector filter used to generate the linear scanned beam profile.

13. 10. The apparatus of claim 9, wherein the spot beam profile is measured by scanning a current detector across an undeflected stationary spot beam.

14. 10. The apparatus of claim 9, wherein the linear scanned beam profile is generated by scanning the spot ion beam at a constant velocity over a predetermined horizontal scan distance.

15. A non-transitory computer-readable storage medium comprising instructions that, when executed by a computer, cause the computer to: receiving a spot beam profile for a spot ion beam; receiving a linear scanned beam profile of the spot ion beam; generating a calculated calibration spot profile based on the spot beam profile and the linear scanned beam profile; implementing an adjusted scanned profile for the spot ion beam based on the calculated calibration spot profile; A non-transitory computer-readable storage medium that causes

16. 16. The non-transitory computer-readable storage medium of claim 15, wherein the instructions further configure the computer to generate the calculated calibration spot profile by performing a convolution operation on the spot beam profile to generate an enlarged spot beam profile.

17. 17. The non-transitory computer-readable storage medium of claim 16, wherein the instructions further configure the computer to generate the calculated calibration spot profile by further generating a delayed enlarged spot beam profile by adjusting the enlarged spot beam profile by a dose controller delay of a dose controller used to control the spot ion beam.

18. 20. The non-transitory computer-readable storage medium of claim 17, wherein the instructions further configure the computer to: generate the calculated calibration spot profile by further applying an area scalar to the delay hypertrophy spot beam profile to generate an area-scaled delay hypertrophy spot beam profile, wherein the area scalar is determined from a ratio of an area of ​​an ideal calibration spot beam profile to an area of ​​the linear scanned beam profile.

19. 20. The non-transitory computer-readable storage medium of claim 18, wherein the instructions further configure the computer to generate the calculated calibration spot profile by further applying a profile speed transient response factor to the area-scaled delay thickened spot beam profile based on a filter response for a detector filter used to generate the linear scanned beam profile.

Images