Semiconductor manufacturing method

Abstract

A semiconductor manufacturing method includes: moving a plurality of sensors relative to an ion beam along a translation path; acquiring sensor signals generated by the sensors; converting the acquired sensor signals into a dataset representing a two-dimensional profile of the ion beam; generating a plurality of first one-dimensional profiles of the ion beam from the dataset; generating a plurality of second one-dimensional profiles of the ion beam by spatially reversing each of the first one-dimensional profiles; generating a plurality of third one-dimensional profiles of the ion beam by superimposing a first current density value of each of the first one-dimensional profiles with a second current density value of a corresponding one of the second one-dimensional profiles; and determining, based on the third one-dimensional profiles, whether to continue using the ion beam to perform an implantation process on a wafer.

Description

Technical Field

[0001] This disclosure relates to a semiconductor manufacturing method, and more particularly to a semiconductor manufacturing method that senses a one-dimensional profile of an ion beam to determine whether to perform an ion implantation process. Background Technology

[0002] The semiconductor industry has experienced rapid growth due to the ever-increasing integration density of various electronic components, such as transistors, diodes, resistors, and capacitors. In most cases, this advancement in integration density stems from the continuous shrinking of the smallest feature size, allowing more components to be integrated into a given area. With the recent increasing demand for miniaturization, higher speeds, wider bandwidths, and lower power consumption and latency, the need for smaller, more innovative semiconductor die packaging technologies is also growing.

[0003] With the development of semiconductor technology, semiconductor manufacturing processes have become more complex, thus requiring sophisticated equipment and fixtures. In semiconductor manufacturing, integrated circuits are fabricated on semiconductor wafers. Before multiple integrated circuits are separated by dicing the semiconductor wafer, it undergoes many process steps. These process steps may include lithography, etching, doping, and deposition of different materials.

[0004] Ion implantation is a process technology used to dope different atoms or molecules into a wafer. By employing ion implantation, the majority of charge carriers can be altered to create regions with different types and degrees of conductivity within the wafer. In an ion implantation machine, an ion generator produces an ion beam and directs it towards the target wafer.

[0005] Before performing the ion implantation process, various ion implantation monitoring systems can be used to characterize the ion beam. Summary of the Invention

[0006] This disclosure provides a semiconductor manufacturing method for ion implantation of a wafer, comprising: moving a sensor relative to an ion beam along a translation path; acquiring sensor signals generated by the sensor at multiple locations along the translation path; converting the acquired sensor signals into a dataset representing a two-dimensional profile of the ion beam; generating multiple first one-dimensional profiles of the ion beam from the dataset, each of the first one-dimensional profiles having a first set of current density values; generating multiple second one-dimensional profiles of the ion beam by spatially reversing each of the first one-dimensional profiles of the ion beam, each of the second one-dimensional profiles having a second set of current density values; generating multiple third one-dimensional profiles of the ion beam by superimposing the first current density value of each of the first one-dimensional profiles with the second current density value of a corresponding one of the second one-dimensional profiles; determining, based on the third one-dimensional profiles, whether to continue using the ion beam to perform the implantation process on the wafer; and, in response to the decision to continue the implantation process, performing the implantation process on the wafer using the ion beam.

[0007] This disclosure provides a semiconductor manufacturing method for ion beam uniformity control, comprising: generating an ion beam in an ion implantation system; acquiring a dataset representing a two-dimensional (2D) profile of the ion beam; generating a plurality of first one-dimensional (1D) profiles of the ion beam from the dataset; generating a plurality of second one-dimensional profiles of the ion beam from the first one-dimensional profiles of the ion beam; superimposing current density values ​​of the second one-dimensional profiles of the ion beam to generate a combined one-dimensional profile of the ion beam; calculating an average one-dimensional profile of the ion beam by dividing the current density value of the combined one-dimensional profile by the number of second one-dimensional profiles of the ion beam; and determining whether to continue the implantation process with the ion beam based on the average one-dimensional profile of the ion beam.

[0008] This disclosure provides a semiconductor manufacturing method, including: moving an ion beam profilometer along a translation path relative to an ion beam such that the ion beam profilometer covers the entire cross-sectional area of ​​the ion beam; acquiring a dataset representing a two-dimensional (2D) profile of the ion beam using a plurality of sensors on the ion beam profilometer, the plurality of sensors being linearly separated in a direction perpendicular to the translation path; generating a first one-dimensional (1D) profile of the ion beam from the dataset; and calculating the standard deviation of the first one-dimensional profile of the ion beam compared to an optimized beam profile, wherein the optimized beam profile includes the average of a plurality of second one-dimensional profiles. Attached Figure Description

[0009] The concepts of embodiments of this disclosure will be better understood by referring to the following detailed description and accompanying drawings. It should be noted that, according to industry standard practice, the various features in the drawings are not necessarily drawn to scale. In fact, the dimensions of various features may be arbitrarily enlarged or reduced for clarity. Similar features are designated with similar reference numerals throughout the specification and drawings.

[0010] Figure 1A schematic diagram of an ion implantation system according to an embodiment of the present disclosure is shown.

[0011] Figure 2A and Figure 2B A schematic diagram illustrating an apparatus for measuring the two-dimensional (2D) profile of an ion beam according to an embodiment of the present disclosure.

[0012] Figure 3A A flowchart illustrating a system for monitoring and controlling the uniformity of an ion implantation process is provided.

[0013] Figure 3B A method for standardized beam current measurement according to an embodiment of this disclosure is illustrated.

[0014] Figure 3C A scale bar for an example two-dimensional color drawing depicting the outline of an ion beam.

[0015] Figure 3D and Figure 3E A method for generating multiple one-dimensional (1D) bundle profiles according to an embodiment of the present disclosure is illustrated.

[0016] Figure 3F The optimal beam profile according to an embodiment of the present disclosure is illustrated.

[0017] The reference numerals in the attached figures are explained as follows:

[0018] 18: Ion Implantation System

[0019] 20: Power supply

[0020] 22: Ion source

[0021] 24: Extraction electrode

[0022] 26: Ion beam

[0023] 27: Ion Beam Characterizer

[0024] 28: Mass analyzer magnet

[0025] 30: Quality Analysis Well

[0026] 32: Corrector magnet

[0027] 34: Wafer

[0028] 36: Movable platform

[0029] 37: Terminal Station

[0030] 38: Ion Beam Profilometer

[0031] 39: Frame or shell

[0032] 40, 42, 44: Sensors

[0033] 46, 48, 50: Ammeter

[0034] 52: Controller

[0035] 54: Region

[0036] 56: First one-dimensional bundle profile

[0037] 58: Second one-dimensional bundle profile

[0038] 59: Third one-dimensional bundle profile

[0039] 62, 64, 66, 67, 68, 70, 72, 74, 76, 78: Flowchart frames (boxes)

[0040] 90: Optimal beam profile

[0041] 92: Sampling area

[0042] 100: Ion Implantation Process

[0043] AA: Center line

[0044] BB, CC: Direction

[0045] E: Line

[0046] D1: Distance

[0047] K: First point

[0048] S1, S2: Spacing Detailed Implementation

[0049] The following disclosure provides numerous different embodiments or examples to implement various features of the embodiments of this disclosure. Reference numerals and / or letters may be repeated in the various examples described in this disclosure. These repetitions are for the purpose of brevity and clarity and do not in themselves imply any relationship between the various embodiments and / or configurations disclosed. Furthermore, specific examples of components and configurations are described below to simplify the description of the embodiments of this disclosure. Of course, these specific examples are merely illustrative and not intended to limit the embodiments of this disclosure. For example, in the following description, reference to a first feature being formed on or above a second feature indicates that it may include embodiments where the first and second features are in direct contact, or embodiments where an additional feature is formed between the first and second features, so that the first and second features may not be in direct contact. Furthermore, reference numerals and / or letters may be repeated in the various examples of this disclosure. Such repetitions are for the purpose of brevity and clarity and do not in themselves limit the relationship between the various embodiments and / or configurations described.

[0050] In addition, spatially related terms may be used herein. For example, “below,” “under,” “lower,” “above,” “higher,” and similar terms are used to describe the relationship between one element or feature depicted in the diagram and another element(s). Besides the orientation shown in the diagram, these spatially related terms are intended to include different orientations of the device in use or operation. The device may be turned to different orientations (rotated 90 degrees or other orientations), and the spatially related terms used herein may be interpreted in the same way.

[0051] Various embodiments provide a method for monitoring and controlling the uniformity of a first ion implantation process. This method is applicable to various ion implantation processes and devices, such as high-energy ion implanters, high-current ion implanters, medium-current implanters, etc., and can be used to characterize the ion beam before the first ion implantation process is completed. Embodiments include using an ion beam profilometer to measure the ion beam profile. The ion beam profilometer is configured to generate a sensor signal in response to the incident ions of the ion beam along a translation path. The acquired sensor signal represents the two-dimensional (2D) profile of the ion beam. The 2D profile of the ion beam is then processed and compared with a baseline, an "optimized," or a "golden" beam profile to determine whether the first ion implantation process can be performed or whether the beam profile of the ion beam should be adjusted. Advantageous features of the embodiments disclosed herein include better ion beam uniformity control and improved ion implantation uniformity on the first wafer and during the first ion implantation process. Furthermore, the disclosed method can be easily integrated into existing processes without any hardware changes, thereby reducing manufacturing costs.

[0052] Figure 1 An embodiment of an ion implantation system 18 is illustrated, which is housed in a high-vacuum environment. The ion implantation system 18 may include an ion source 22 for generating ions and providing an ion beam 26. A gas is supplied to the ion source 22, where it is ionized and ions are extracted to form the ion beam 26. The ion source 22 is powered by a power source 20. The ion implantation system 18 includes one or more extraction electrodes 24 for extracting ions from the ion source 22 and guiding the ion beam 26 to a mass analyzer magnet 28. The mass analyzer magnet 28 is used to deflect the ions in the ion beam 26 so that only the desired ion species can pass through a mass analysis aperture 30. The ion beam 26 passing through the mass analysis aperture 30 passes through a corrector magnet 32 ​​for converting the ion beam 26 from a divergent ion beam into an ion beam with generally parallel ion trajectories (e.g., a ribbon ion beam). The corrector magnet 32 ​​also guides the ion beam 26 to a wafer 34, which is supported on a movable stage 36 of a terminal station 37.

[0053] Wafer 34 can be made of silicon or other semiconductor materials such as silicon germanium. Before forming a complete die, wafer 34 can undergo numerous process steps, such as lithography, etching, and doping. During the doping process, wafer 34 can be placed on a movable stage 36 for ion implantation. The quality of the resulting die can largely depend on the uniformity of ions embedded in wafer 34. For example, non-uniform distribution of ions in wafer 34 can lead to poor drive current uniformity (IDU) or threshold voltage uniformity (VTU) in the transistors of wafer 34.

[0054] Further reference Figure 1 Terminal 37 includes a movable stage 36, a wafer 34, or another single workpiece (e.g., a display panel or other substrate) supported on the movable stage along the beam path of the ion beam 26 for ion implantation. In one embodiment, the ion implantation system 18 provides a generally stationary ion beam 26 with a rectangular cross-section (e.g., also referred to as a "ribbon beam"), wherein the movable stage 36 (and the wafer 34 supported on the movable stage 36) is translatable (e.g., moved) relative to the stationary ion beam 26 along two generally orthogonal axes. In other embodiments, the ion implantation system 18 provides a generally stationary ion beam 26 with a circular cross-section (e.g., also referred to as a "dot beam" or "pen beam").

[0055] Terminal station 37 may also include an ion beam profilometer 38. The ion beam profilometer 38 is configured to acquire a profile of the cross-section of the ion beam 26, typically in a plane orthogonal to the ion beam propagation direction. In one embodiment, the ion beam 26 may have a rectangular cross-section, wherein the main dimensions of the ion beam 26 cross-section are larger than the dimensions of the ion beam profilometer 38. In one embodiment, the ion beam profilometer 38 is configured to acquire a profile of the cross-section of the ion beam 26 in or near a plane of the wafer 34. However, the ion beam profilometer 38 can acquire the ion beam profile in any desired plane. This is used during ion implantation processes on the wafer 34 (e.g., Figure 3A Prior to the implantation process 100 shown, the beam profile of the ion beam 26 can be obtained by characterizing the ion beam 26 using an ion beam profilometer 38. The beam profile of the ion beam 26 is then compared with an "optimized" or "golden" beam profile (e.g., from...). Figures 2A to 3FThe beam profile of the ion beam 26 is compared with the optimal beam profile 90 obtained by the multiple ion implantation processes 100 described herein. If the beam profile of the ion beam 26 has a standard deviation less than a preset threshold (e.g., 0.07) compared to the optimal beam profile 90, the ion implantation process 100 can be performed on the wafer 34. If the standard deviation of the beam profile compared to the optimal beam profile 90 is equal to or greater than the preset threshold, the ion implantation process 100 is not performed on the wafer 34, but an ion beam modulation process is performed to make the standard deviation of the beam profile compared to the optimal beam profile 90 less than the preset threshold. In one embodiment, when the wafer 34 is located in the terminal station 37 and supported on the movable stage 36, the beam profile of the ion beam 26 can be acquired and compared with the optimal beam profile 90. In one embodiment, the beam profile of the ion beam 26 can be acquired and compared with the optimal beam profile 90 even when the wafer 34 is not introduced into the terminal station 37.

[0056] Figures 2A to 3F The diagram illustrates the measurement of the two-dimensional profile of the ion beam 26 using an ion beam profilometer 38 before performing the implantation process 100 on the wafer 34. The two-dimensional profile of the ion beam 26 is then processed and compared with the optimized beam profile 90 to determine whether the implantation process 100 can proceed or whether the beam profile of the ion beam 26 needs to be adjusted. Figure 2A A schematic diagram of an ion implantation system 18 according to an embodiment of the present disclosure is shown. Figure 2B Draw Figure 2A A side view of the ion beam profilometer 38, showing orientation in two directions (e.g., direction BB and direction CC). Figure 3A A flowchart is drawn to illustrate the feedback control system used to monitor and control the uniformity of the ion implantation process 100. This is applied to wafer 34 (e.g., Figure 1 (as shown) to perform ion implantation processes (e.g. Figure 3A Prior to the implantation process 100 shown, the controller 52 can use an ion beam profilometer 38 to characterize the ion beam 26 to obtain its beam profile. The beam profile can be used to determine whether the ion implantation process 100 can continue or whether the beam profile of the ion beam 26 needs adjustment. The ion implantation system 18 includes an ion source 22 and an ion beam characterizer 27. The ion beam characterizer 27 includes an ion beam profilometer 38, multiple sensors 40, 42, and 44, multiple galvanometers 46, 48, and 50, and a controller 52. Figure 2A As shown, ion source 22 generates ion beam 26 and guides ion beam 26 to ion beam profiler 38.

[0057] The ion beam profilometer 38 includes a plurality of sensors 40 / 42 / 44 mounted to a frame or housing 39. Sensing signals from the plurality of sensors 40 / 42 / 44 are sent to a plurality of galvanometers (e.g., galvanometers 46 / 48 / 50). Each of the galvanometers 46 / 48 / 50 may be coupled to a corresponding one of the plurality of sensors 40 / 42 / 44. According to one embodiment, a Faraday cup sensor, for example, may be configured to detect ion particles from the ion beam 26 and convert the number of sensed ion particles into a current value. For example, each of the plurality of sensors 40 / 42 / 44 and its corresponding galvanometer 46 / 48 / 50 may be replaced by a Faraday cup.

[0058] like Figure 2B As shown, the ion beam profilometer 38 includes a plurality of sensors 40 / 42 / 44, wherein sensor 42 is disposed above sensor 44, and sensor 40 is disposed above sensor 42. Other configurations of sensors 40 / 42 / 44 are also possible in other embodiments. Sensor 40 (which may include a Faraday cup) is configured to measure the one-dimensional (1D) profile of the ion beam 26. A plurality of sensors 42 (each of which may include a Faraday cup) are configured to jointly measure the two-dimensional (2D) profile of the ion beam 26. In one embodiment, the ion beam profilometer 38 may include eleven or more sensors 42 linearly spaced in the BB direction. In one embodiment, the spacing S1 between adjacent sensors among the plurality of sensors 42 is the same. A plurality of sensors 44 (each of which may include a Faraday cup) are configured to measure the angular distribution of the cross-section of the ion beam 26, wherein the plane of ion beam transmission is not orthogonal to the plane of the main surface of the ion beam. The plurality of sensors 44 may be linearly spaced in the BB direction. In one embodiment, the spacing S2 between adjacent sensors in the plurality of sensors 44 is the same. In one embodiment, other constructions and configurations of the plurality of sensors 40 / 42 / 44 may be used within the scope of this disclosure.

[0059] Figure 3A Explain the ion beam profiling process. From Figure 3A Beginning at box 62, beam current density measurements are performed to generate a two-dimensional (2D) profile of the ion beam 26. In box 62, the ion beam profilometer 38 (and a plurality of sensors 40 / 42 / 44) is translated (e.g., moved) along a translation path in the CC direction by a translation mechanism controlled by controller 52 to cover the entire cross-sectional area of ​​the ion beam 26. Beam current density measurements are acquired from each of the plurality of sensors 42 as they translate along the translation path. Beam current density measurements can be acquired either while the ion beam profilometer 38 is moving or while the ion beam profilometer 38 is translating using discrete motion (e.g., each time the ion beam profilometer 38 stops along the translation path).

[0060] In one embodiment, thirty-two or more individual beam current density measurements are performed as the ion beam profilometer 38 (and a plurality of sensors 42) translates along a translation path in the CC direction. The ion beam profilometer 38 may include eleven or more sensors 42, which are linearly separated in the BB direction (as previously described). Figure 2B (As shown in the diagram). The ion beam 26 may have a specific width, and eleven or more sensors 42, linearly spaced in the BB direction, measure the width of the ion beam 26 at discrete intervals. In this way, the set of beam current densities measured by the multiple sensors 42 as the ion beam profilometer 38 translates through the ion beam 26 represents a two-dimensional (2D) map of the ion beam current density (or two-dimensional beam profile) of the ion beam 26 in the BB and CC directions. In an alternative embodiment, the ion beam profilometer 38 may include fewer or more than eleven sensors 42, linearly spaced in the BB direction. In one embodiment, the ion beam profilometer 38 translates a distance D1 along the translation path in the CC direction, which may be in the range of approximately -200 mm to approximately +200 mm.

[0061] Multiple sensors 42 measure the beam current in incremental regions across the cross-sectional area of ​​the ion beam 26 to collectively obtain a two-dimensional (2D) plot of the beam current density. The 2D plot is a spatially accurate map of the beam current density and can be configured such that each incremental region of the beam cross-section contains the measured beam current density. As the ion beam profilometer 38 translates (e.g., moves along a translation path) and the ion beam 26 strikes a corresponding sensor among the multiple sensors 42, a current signal can be generated by the galvanometer 48 or each of the multiple sensors 42 (e.g., when each of the multiple sensors 42 includes a Faraday cup). This current signal from the galvanometer 48 or each of the multiple sensors 42 (e.g., when each of the multiple sensors 42 includes a Faraday cup) is sent to the controller 52. The controller 52 correlates the temporal correlation of the signals from each of the multiple sensors 42 with the scanning position of the ion beam 26 and calculates a spatially accurate two-dimensional plot of the beam current density.

[0062] Next, controller 52 uses the set of current density measurements (or two-dimensional raw data) collected in flowchart block 62 (also known as the dataset) to generate Figure 3A A two-dimensional color display or diagram of the ion beam profile in flowchart frame 64. (e.g.) Figure 3BAs shown, the acquired beam current measurements are normalized to a range from a minimum of 0 (e.g., the lowest beam current measured) to a maximum of 1 (e.g., the highest beam current measured). The acquired beam current density measurements can also optionally be normalized to a percentage value from a minimum of 0% to a maximum of 100%. These different sub-ranges of normalized beam current density values ​​from 0 to 1 (or from 0% to 100%) are assigned different colors, and the normalized beam current density measurements are output or displayed as a two-dimensional color map configured with square dots, where each dot contains a color to represent the measured beam current density in an incremental region of the ion beam cross-section 26. Figure 3C A scale bar for an example two-dimensional color plot illustrating the ion beam profile, where different positions on the scale represent different colors. Each color for each subrange of normalized beam current values ​​may have a different hue to represent a region within the subrange with a larger or smaller beam current density. In one embodiment, the measured beam current density values ​​may be normalized such that blue is assigned to normalized beam current density values ​​in the range from 0 to less than 0.44, green is assigned to normalized beam current density values ​​in the range from 0.44 to less than 0.56, yellow is assigned to normalized beam current density values ​​in the range from 0.56 to less than 0.66, orange is assigned to normalized beam current density values ​​in the range from 0.66 to less than 0.84, and red is assigned to normalized beam current density values ​​in the range from 0.84 to 1.

[0063] The two-dimensional beam current density of the collected ion beam 26 was measured (e.g.) Figure 3A Normalization (as shown in flowchart 62) to a range from a minimum value of 0 (e.g., the lowest measured beam current) to a maximum value of 1 (e.g., the highest measured beam current) before generating a two-dimensional color display or ion beam profile map has advantages. A wide range of colors can be used in the two-dimensional color map, making it easier to observe differences in the beam profile of the ion beam 26. Furthermore, assigning different colors to the normalized beam current density measurements, as described above, allows for the observation of normalized beam current densities higher than 0.44 across a larger number of colors and hues, thereby making it easier to distinguish differences in the beam current density of the sub-beam 26.

[0064] exist Figure 3A In the steps shown in flowchart block 66, the collection of beam current density measurements (or two-dimensional raw data) collected during the steps shown in flowchart block 62 (also referred to as the dataset) is subsequently used to generate multiple first one-dimensional (1D) profiles of the ion beam 26. Figure 3DAs shown, the controller 52 can generate multiple first one-dimensional beam profiles from two-dimensional beam current density measurements obtained from multiple sensors 42 of the ion beam profilometer 38. Each first one-dimensional beam profile generates a spatially accurate one-dimensional view of the ion beam 26 by plotting the beam current density values ​​measured along a single axis by each of the multiple sensors 42 (from the two-dimensional raw data in flowchart block 62 above). Therefore, each first one-dimensional beam profile contains information about a specific cross-sectional portion of the ion beam 26. The number of first one-dimensional beam profiles generated can be the same as the number of sensors 42 present in the ion beam profilometer 38 (e.g., assuming the ion beam profilometer 38 has eleven sensors 42, eleven first one-dimensional beam profiles will be generated). In one embodiment, only the region 54 of the ion beam profilometer 38 (e.g., Figure 2B The beam current density measurements (or two-dimensional raw data) collected in region 54 are used to generate multiple first one-dimensional beam profiles. In one embodiment, the width W1 of region 54 may be in the range of about 100 mm to about 150 mm. For example, beam current measurements (two-dimensional raw data) may be collected within region 54 to generate multiple first one-dimensional beam profiles, wherein region 54 is located at its centerline AA (as shown). Figure 2B The centerline AA extends from -50 mm to +50 mm on either side of the region 54 (as shown), and is also the centerline of the ion beam profilometer 38. In one embodiment, the number of first one-dimensional beam profiles generated within region 54 is the same as the number of sensors 42 present (e.g., assuming region 54 has eleven sensors 42, then eleven first one-dimensional beam profiles are generated).

[0065] In the steps shown in flowchart block 67, then... Figure 3A During the steps shown in flowchart block 66, multiple first one-dimensional bundle contours are generated to produce multiple spatially inverted second one-dimensional bundle contours. Each of the multiple second one-dimensional bundle contours is generated for a corresponding one of the multiple first one-dimensional bundle contours. Each second one-dimensional bundle contour (e.g., ...) Figure 3E The second one-dimensional beam profile 58 is obtained by spatial reversal along the translation path (e.g., in the CC direction of the ion beam profilometer 38 translation). In some embodiments, each second one-dimensional beam profile (e.g.) Figure 3E The second one-dimensional bundle profile 58) is the first one-dimensional bundle profile (e.g. Figure 3D and Figure 3E The corresponding one in the first one-dimensional bundle profile 56) passes through the first point (e.g.) along the translation path (e.g., the CC direction). Figure 3E The line (e.g., point K) in the middle Figure 3E The mirror image of line E in the middle.

[0066] Subsequently, in flowchart block 68, controller 52 calculates multiple third one-dimensional bundle contours based on the second one-dimensional bundle contour and its corresponding first one-dimensional bundle contour. To calculate each of the multiple third one-dimensional bundle contours (e.g., third one-dimensional bundle contour 59), each spatially inverted second one-dimensional bundle contour (e.g., ...) is used. Figure 3E The beam current density value of the second one-dimensional beam profile (58) is increased (or superimposed) along the translation path (e.g., the CC direction) relative to the first point K or the measurement position of the corresponding first one-dimensional beam profile (e.g., ...). Figure 3E The beam current density value of the first one-dimensional beam profile 56 in the image, for example, each second one-dimensional beam profile and its corresponding first one-dimensional beam profile relative to the vertical line passing through the first point K (e.g., Figure 3E Line E in the diagram is a mirror image of each other.

[0067] In an alternative embodiment, in order to compute each of the plurality of third one-dimensional bundle profiles, each spatially inverted second one-dimensional bundle profile (e.g.) Figure 3E The beam current density values ​​of the second one-dimensional beam profile (58) and their corresponding first one-dimensional beam profile (e.g., ... Figure 3E The beam current density value of the first one-dimensional beam profile (56) is multiplied by a constant (e.g., two). This constant value may correspond to the number of times the wafer will subsequently be rotated during the implantation process. Next, along the translation path (e.g., the CC direction) relative to the first point K or measurement position, the multiplied beam current density value of each spatially reversed second one-dimensional beam profile is added to (or superimposed on) the multiplied beam current density value of its corresponding first one-dimensional beam profile, such that each second one-dimensional beam profile and its corresponding first one-dimensional beam profile are relative to a vertical line passing through the first point K (e.g., ...). Figure 3E Lines E in the diagram are mirror images of each other. In one embodiment, the number of the plurality of first one-dimensional bundle profiles is the same as the number of the plurality of second one-dimensional bundle profiles. In another embodiment, the number of the plurality of first one-dimensional bundle profiles is the same as the number of the plurality of third one-dimensional bundle profiles.

[0068] In the steps shown in flowchart block 70, Figure 3A During the steps shown in flowchart block 68, all calculated beam current density values ​​of the multiple third one-dimensional beam profiles generated are added together (or superimposed) to obtain a combined one-dimensional beam profile. Subsequently, as shown in flowchart block 72, an average one-dimensional beam profile is calculated by dividing the beam current density value of the combined one-dimensional beam profile by the number of third one-dimensional beam profiles among the multiple third one-dimensional beam profiles.

[0069] In the steps shown in flowchart block 74, the next step will be... Figure 3A The average one-dimensional beam profile generated in flowchart 72 is compared with the optimized or gold beam profile 90 stored in the memory or controller 52 of the ion implantation system 18 (e.g., Figure 3FThe optimized or gold beam profile 90 is compared to that shown. It is obtained from a previous ion implantation process 100 performed on a wafer (e.g., similar to wafer 34). After the ion implantation process 100 on the wafer, thermographic measurements are performed on each wafer to measure the wafer's reflectivity, thereby generating a corresponding thermographic uniformity distribution. The thermographic measurements (and thermographic uniformity distribution) on each wafer show a high correlation with the ion implantation uniformity on the implanted wafer. The thermographic measurements may involve scanning the wafer with an ion beam. Multiple thermographic uniformity distributions exhibiting good or optimal uniformity are selected, and their corresponding average one-dimensional beam profiles (generated in a manner similar to that shown in flowchart blocks 62 to 72 above) are added together (e.g., superimposed). The optimized beam profile 90 is then calculated by obtaining the average of these superimposed average one-dimensional beam profiles (e.g., by dividing the beam current density value of the superimposed average one-dimensional beam profile by the number of selected multiple thermographic uniformity distributions). The optimal beam profile 90 can then be compared with the average one-dimensional beam profile of the ion beam 26 generated in flowchart block 72 to confirm that the ion beam 26 profile is within specifications. The optimal beam profile 90 can be updated using other selected average one-dimensional beam profiles of thermal wave uniformity distributions that exhibit good or optimal uniformity when obtained.

[0070] Advantages can be achieved by measuring the profile of the ion beam 26 using an ion beam profilometer 38 prior to the ion implantation process 100 on wafer 34. The ion beam profilometer 38 is configured to acquire a two-dimensional beam profile of the ion beam 26, which is then used to generate multiple first one-dimensional (1D) profiles of the ion beam 26, multiple spatially inverted second one-dimensional beam profiles for each first one-dimensional beam profile, and multiple third one-dimensional beam profiles calculated by adding (or superimposing) the beam current density value of each spatially inverted second one-dimensional beam profile to the beam current density value of its corresponding first one-dimensional beam profile. An average one-dimensional beam profile is calculated from the multiple third one-dimensional beam profiles and then compared to an optimized beam profile 90 to determine whether the ion implantation process 100 can be performed on wafer 34 or whether the beam profile of the ion beam 26 should be adjusted. Advantages may include better ion beam uniformity adjustment and improved ion implantation uniformity on wafer 34 during the ion implantation process 100. Furthermore, the disclosed method can be easily integrated into existing processes without any hardware changes, thus reducing manufacturing costs.

[0071] Further referring to flowchart frame 74, the average one-dimensional bundle profile generated in flowchart frame 72 is standardized to the optimal bundle profile 90 within the selected sampling region 92 (e.g., ...). Figure 3F The average value (as shown). The selected sampling region 92 can be located on either side of the vertical line passing through the center point of the average one-dimensional bundle profile (e.g., at 0 mm) and within the range of +30 mm to +120 mm and -30 mm to -120 mm, as shown. Figure 3FAs shown. Subsequently, controller 52 calculates the standard deviation of the average one-dimensional beam profile compared to the optimized beam profile 90.

[0072] like Figure 3A As shown in flowchart 76, if the average one-dimensional beam profile in sampling region 92 has a standard deviation less than a preset threshold (e.g., 0.07) compared to the optimized beam profile 90, then the profile of ion beam 26 is considered to be within specifications and on wafer 34 (e.g., ...). Figure 1 Ion implantation process 100 is performed on the ion beam 26 (as shown). If the standard deviation of the average one-dimensional beam profile is equal to or greater than a preset threshold (e.g., 0.07) compared to the optimized beam profile 90, the ion beam 26 profile is considered to be outside the required specifications and ion implantation process 100 is not performed. Instead, the controller 52 may employ a feedback algorithm, which can send signals to adjust the beam profile by controlling various parameters of the ion beam 26 (as shown in flowchart block 78), such as beam intensity, beam height, beam incident angle (also known as beam angle), beam divergence angle (also known as beam divergence angle), and beam width, so that the standard deviation of the average one-dimensional beam profile compared to the optimized profile is less than the preset threshold (e.g., 0.07). After the ion beam 26 is adjusted, an updated average one-dimensional beam profile can be obtained to confirm the adjustment and check whether the adjusted ion beam 26 falls within the required specifications.

[0073] Controller 52 can be used to perform Figure 3A The process flow includes numerous steps to generate an average one-dimensional bundle profile and, based on the generated average one-dimensional bundle profile, to determine whether to continue implantation. The controller 52 can be implemented in hardware or software. In some embodiments, the controller 52 includes circuitry such as an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), etc. In some embodiments, the controller 52 is a computer including a processor operable to execute a program. For illustrative purposes, the controller 52 is illustrated as a single element. In some embodiments, the controller 52 includes multiple elements. The controller 52 may include components configured to store information for implementing... Figure 3A The parameters of the process block are stored in memory (e.g., volatile or non-volatile memory). The parameters can be hard-written or input to the controller 52 via an input device.

[0074] The embodiments of this disclosure have several advantageous features. One embodiment includes measuring the profile of an ion beam using an ion beam profilometer prior to a first ion implantation process on a first wafer. The ion beam profilometer is configured to generate a sensor signal in response to incident ions along a translational path relative to the ion beam. The acquired sensor signal represents a two-dimensional (2D) profile of the ion beam. The 2D profile of the ion beam is then processed and compared to a baseline, “optimized,” or “golden” beam profile to determine whether the first ion implantation process can proceed or whether the beam profile of the ion beam implantation tool should be adjusted. One or more embodiments of this disclosure can allow for better ion beam uniformity control and improved ion implantation uniformity on the first wafer and during the first ion implantation process. Furthermore, the disclosed method can be readily integrated into existing processes without any hardware changes, thereby reducing manufacturing costs.

[0075] According to one embodiment, a method for ion implantation of a wafer includes moving a plurality of sensors relative to an ion beam along a translation path; acquiring sensor signals generated by the plurality of sensors at a plurality of locations along the translation path; converting the acquired sensor signals into a dataset representing a two-dimensional (2D) profile of the ion beam; generating a plurality of first one-dimensional (1D) profiles of the ion beam from the dataset, each of the plurality of first one-dimensional profiles having a first set of current density values; generating a plurality of second one-dimensional profiles of the ion beam by spatially reversing each of the plurality of first one-dimensional profiles of the ion beam, each of the plurality of second one-dimensional profiles having a second set of current density values; generating a plurality of third one-dimensional profiles of the ion beam by superimposing the first current density value of each of the plurality of first one-dimensional profiles with a second current density value of a corresponding one of the plurality of second one-dimensional profiles; determining, based on the plurality of third one-dimensional profiles, whether to continue the implantation process using the ion beam; and, in response to the decision to continue the implantation process, performing the implantation process using the ion beam on the wafer.

[0076] In one embodiment, the plurality of sensors includes at least eleven sensors linearly separated in a direction perpendicular to the translation path.

[0077] In one embodiment, the plurality of third one-dimensional profiles for generating the ion beam include superimposing a first current density value of each of the plurality of first one-dimensional profiles with a second current density value of a corresponding one of the plurality of second one-dimensional profiles relative to a first point along the translation path, such that each of the plurality of first one-dimensional profiles and the corresponding one of the plurality of second one-dimensional profiles are mirror images of each other with respect to a vertical line passing through the first point.

[0078] In one embodiment, the method further includes superimposing a third current density value of each of a plurality of third one-dimensional profiles of the ion beam to generate a superimposed current density value of the plurality of third one-dimensional profiles of the ion beam, and calculating an average one-dimensional profile of the ion beam based on the superimposed current density value of the plurality of third one-dimensional profiles of the ion beam.

[0079] In one embodiment, the method further includes calculating the standard deviation of the average one-dimensional profile of the ion beam compared to the optimized profile, which is stored on the controller.

[0080] In one embodiment, the method further includes adjusting the parameters of the ion beam when the standard deviation is equal to or greater than a preset threshold.

[0081] In one embodiment, determining whether to continue the implantation process on the wafer using an ion beam based on multiple third-dimensional profiles includes deciding to continue the implantation process when the standard deviation is less than a preset threshold.

[0082] In one embodiment, the parameters of the ion beam include beam intensity, beam height, beam width, or a combination thereof.

[0083] According to one embodiment, a method for ion beam uniformity control includes generating an ion beam in an ion implantation system; acquiring a dataset representing a two-dimensional (2D) profile of the ion beam; generating a plurality of first one-dimensional (1D) profiles of the ion beam from the dataset; generating a plurality of second one-dimensional profiles of the ion beam from the plurality of first one-dimensional profiles of the ion beam; superimposing the current density values ​​of the plurality of second one-dimensional profiles of the ion beam to generate a combined one-dimensional profile of the ion beam; calculating an average one-dimensional profile of the ion beam by dividing the current density value of the combined one-dimensional profile by the number of the plurality of second one-dimensional profiles of the ion beam; and determining whether to continue the implantation process with the ion beam based on the average one-dimensional profile of the ion beam.

[0084] In one embodiment, acquiring a dataset representing a two-dimensional (2D) profile of the ion beam further includes moving an ion beam profilometer along a translational path covering a cross-sectional region of the ion beam.

[0085] In one embodiment, generating multiple second one-dimensional contours of the ion beam from multiple first one-dimensional contours of the ion beam includes generating multiple third one-dimensional contours of the ion beam by spatially reversing each of the multiple first one-dimensional contours. Each of the multiple first one-dimensional contours has a first set of current density values, and each of the multiple third one-dimensional contours has a second set of current density values; and the first set of current density values ​​of each of the multiple first one-dimensional contours is superimposed with the second set of current density values ​​of a corresponding one of the multiple third one-dimensional contours relative to a first point along the translation path, such that each of the multiple first one-dimensional contours and the corresponding one of the multiple third one-dimensional contours are mirror images of each other with respect to a vertical line passing through the first point.

[0086] In one embodiment, the ion beam profilometer includes a plurality of sensors linearly spaced in a direction perpendicular to the translation path.

[0087] In one embodiment, the method further includes calculating the standard deviation of the average one-dimensional profile of the ion beam compared to the optimized profile, wherein the optimized profile includes the average of a plurality of one-dimensional thermal wave uniformity distributions.

[0088] In one embodiment, the method further includes adjusting the beam intensity, beam height, beam width, or a combination thereof of the ion beam when the standard deviation is equal to or greater than a preset threshold.

[0089] According to one embodiment, a method includes moving an ion beam profilometer along a translation path relative to an ion beam such that the ion beam profilometer covers the entire cross-sectional region of the ion beam; acquiring a dataset representing a two-dimensional (2D) profile of the ion beam using multiple sensors on the ion beam profilometer, the multiple sensors being linearly separated in a direction perpendicular to the translation path; generating a first one-dimensional (1D) profile of the ion beam from the dataset; and calculating the standard deviation of the first one-dimensional profile of the ion beam compared to an optimized ion beam profile, wherein the optimized ion beam profile includes the average of multiple second one-dimensional profiles.

[0090] In one embodiment, the ion beam profilometer is moved a first distance of up to 200 mm.

[0091] In one embodiment, each of the plurality of sensors includes a Faraday cup.

[0092] In one embodiment, each of the plurality of second one-dimensional contours corresponds to a previously performed corresponding optimized ion implantation process.

[0093] In one embodiment, the first one-dimensional profile of the ion beam is normalized to the average value of the optimal ion beam profile within the first sampling region.

[0094] In one embodiment, generating a first one-dimensional profile of the ion beam includes generating a plurality of third one-dimensional profiles of the ion beam from a dataset representing two-dimensional profiles of the ion beam, wherein the dataset is obtained from an ion beam profilometer extending from -50 mm to +50 mm on either side of the vertical centerline of the ion beam profilometer, each of the plurality of third one-dimensional profiles having a first set of current density values; generating a plurality of fourth one-dimensional profiles of the ion beam from the plurality of third one-dimensional profiles, each of the plurality of fourth one-dimensional profiles having a second set of current density values; superimposing the first current density value of each of the plurality of third one-dimensional profiles with the second current density value of a corresponding one of the plurality of fourth one-dimensional profiles to generate a plurality of fifth one-dimensional profiles of the ion beam; superimposing the current density values ​​of the plurality of fifth one-dimensional profiles of the ion beam to generate a combined one-dimensional profile of the ion beam; and calculating an average one-dimensional profile of the ion beam by dividing the current density value of the combined one-dimensional profile by the number of the plurality of fifth one-dimensional profiles of the ion beam.

[0095] The foregoing has outlined the features of numerous embodiments to enable those skilled in the art to better understand the various embodiments of this disclosure. Those skilled in the art will understand that other processes and structures can be easily designed or modified based on the embodiments of this disclosure to achieve the same objectives and / or advantages as the embodiments described herein. Those skilled in the art will also understand that these equivalent structures do not depart from the spirit and scope of this disclosure. Various changes, substitutions, and modifications can be made to the embodiments of this disclosure without departing from the spirit and scope of the appended claims.

Claims

1. A semiconductor manufacturing method for ion implantation into a wafer, comprising: Multiple sensors are moved relative to an ion beam along a translational path; Acquire multiple sensor signals generated by the sensor at multiple locations along the translation path; The acquired sensor signal is converted into a dataset representing a one- or two-dimensional profile of the ion beam. Multiple first one-dimensional profiles of the ion beam are generated from the dataset, each of the first one-dimensional profiles having a first set of current density values. Multiple second one-dimensional profiles of the ion beam are generated by spatially reversing each of the first one-dimensional profiles of the ion beam, each of the second one-dimensional profiles having a second set of current density values. Multiple third one-dimensional profiles of the ion beam are generated by superimposing the first current density value of each of the first one-dimensional profiles with the second current density value of the corresponding one of the second one-dimensional profiles. Based on the third one-dimensional profile, it is determined whether to continue using the ion beam to perform an implantation process on the wafer; as well as In response to the decision to continue the implantation process, the wafer was implanted using the ion beam.

2. The semiconductor manufacturing method of claim 1, wherein the sensor comprises at least eleven sensors linearly separated in a direction perpendicular to the translation path.

3. The semiconductor manufacturing method of claim 1, wherein the third one-dimensional profile for generating the ion beam comprises superimposing the first current density value of each of the first one-dimensional profiles with the second current density value of a corresponding one of the second one-dimensional profiles relative to a first point along the translation path, such that each of the first one-dimensional profiles and the corresponding one of the second one-dimensional profiles are mirror images of each other with respect to a vertical line passing through the first point.

4. The semiconductor manufacturing method as described in claim 1, further comprising: Multiple third current density values ​​of each of the third one-dimensional profiles of the ion beam are superimposed to generate multiple superimposed current density values ​​of the third one-dimensional profile of the ion beam; and An average one-dimensional profile of the ion beam is calculated based on the superimposed current density value of the third one-dimensional profile of the ion beam.

5. The semiconductor manufacturing method of claim 4, further comprising comparing the average one-dimensional profile of the ion beam with an optimized profile, the optimized profile being stored on a controller.

6. The semiconductor manufacturing method of claim 5 further includes adjusting a plurality of parameters of the ion beam based on a comparison result of the average one-dimensional profile of the ion beam and the optimized profile.

7. The semiconductor manufacturing method of claim 6, wherein the ion beam has a rectangular or circular cross-section.

8. The semiconductor manufacturing method of claim 7, wherein the parameters of the ion beam include beam intensity, beam height, beam width, or a combination thereof.

9. A semiconductor manufacturing method for controlling ion beam uniformity, comprising: An ion beam is generated in an ion implantation system; Obtain a dataset representing a one- or two-dimensional profile of the ion beam; Multiple first-dimensional profiles of the ion beam are generated from this dataset; Multiple second one-dimensional profiles of the ion beam are generated from the first one-dimensional profile of the ion beam; Multiple current density values ​​of the second one-dimensional profile of the ion beam are superimposed to generate a combined one-dimensional profile of the ion beam. An average one-dimensional profile of the ion beam is calculated by dividing multiple current density values ​​of the combined one-dimensional profile by the number of second one-dimensional profiles of the ion beam. as well as The decision to continue using the ion beam for an implantation process is based on the average one-dimensional profile of the ion beam.

10. The semiconductor manufacturing method of claim 9, wherein acquiring the dataset representing the two-dimensional profile of the ion beam further comprises moving an ion beam profilometer along a translational path covering a cross-sectional region of the ion beam.

11. The semiconductor manufacturing method of claim 10, wherein generating the second one-dimensional profile of the ion beam from the first one-dimensional profile of the ion beam comprises: Multiple third one-dimensional profiles of the ion beam are generated by spatially reversing each of the first one-dimensional profiles, each of the first one-dimensional profiles having a first set of current density values, and each of the third one-dimensional profiles having a second set of current density values. as well as The first set of current density values ​​of each of the first one-dimensional contours is superimposed with the second set of current density values ​​of the corresponding one of the third one-dimensional contours relative to a first point along the translation path, such that each of the first one-dimensional contours and the corresponding one of the third one-dimensional contours are mirror images of each other with respect to a vertical line passing through the first point.

12. The semiconductor manufacturing method of claim 10, wherein the ion beam profilometer includes a plurality of sensors linearly spaced in a direction perpendicular to the translation path.

13. The semiconductor manufacturing method of claim 9, further comprising comparing the average one-dimensional profile of the ion beam with an optimized profile, wherein the optimized profile includes an average value of a plurality of one-dimensional thermal wave uniformity distributions.

14. The semiconductor manufacturing method of claim 13, further comprising adjusting the beam intensity, beam height, beam width, or a combination thereof of the ion beam based on a comparison result of the average one-dimensional profile of the ion beam and the optimized profile.

15. A semiconductor manufacturing method, comprising: An ion beam profiler is moved along a translational path relative to an ion beam such that the ion beam profiler covers an entire cross-sectional area of ​​the ion beam. A dataset representing a one- or two-dimensional profile of the ion beam is acquired using multiple sensors on an ion beam profilometer, the sensors being linearly separated in a direction perpendicular to the translation path; A first one-dimensional profile of the ion beam is generated from the dataset, wherein generating the first one-dimensional profile of the ion beam includes: Multiple second one-dimensional profiles of the ion beam are generated from the dataset representing the two-dimensional profile of the ion beam, wherein the dataset is obtained from a region extending from -50 mm to +50 mm on either side of a vertical centerline of the ion beam profilometer, and each of the second one-dimensional profiles has a first set of current density values. Multiple third one-dimensional profiles of the ion beam are generated from the second one-dimensional profile, each of the third one-dimensional profiles having a second set of current density values. as well as The first set of current density values ​​for each of the second one-dimensional profiles is superimposed with the second set of current density values ​​for the corresponding one of the third one-dimensional profiles to generate a plurality of fourth one-dimensional profiles of the ion beam; and The first one-dimensional profile of the ion beam is compared with an optimal beam profile, wherein the optimal beam profile includes an average of a plurality of fifth one-dimensional profiles.

16. The semiconductor manufacturing method of claim 15, wherein the ion beam profilometer is moved a first distance of up to 200 mm.

17. The semiconductor manufacturing method of claim 15, wherein each of the sensors comprises a Faraday cup.

18. The semiconductor manufacturing method of claim 15, wherein each of the fifth one-dimensional profiles corresponds to a previously performed optimized ion implantation process.

19. The semiconductor manufacturing method of claim 18, wherein the first one-dimensional profile of the ion beam is normalized to an average value of the optimized beam profile within a first sampling region.

20. The semiconductor manufacturing method of claim 15, wherein the first one-dimensional profile for generating the ion beam further comprises: Multiple current density values ​​of the fourth one-dimensional profile of the ion beam are superimposed to generate a combined one-dimensional profile of the ion beam. as well as An average one-dimensional profile of the ion beam is calculated by dividing multiple current density values ​​of the combined one-dimensional profile by the number of the fourth one-dimensional profiles of the ion beam.

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