TW202143277A - High brightness low energy spread pulsed electron source - Google Patents

Abstract

Systems and methods for enhancing inspection throughput with a high brightness low energy spread pulsed electron source are described. A plurality of pulsed constituent electron beams are generated. The plurality of pulsed constituent electron beams are combined into a combined electron inspection beam. The combined electron inspection beam has a greater brightness than each of the individual constituent pulsed electron beams. An energy spread of an incoming electron pulse is increased by accelerating a front of the pulse and decelerating a back of the pulse; temporally stretching the pulse using a drift space; and monochromating the pulse by decelerating the front of the pulse and accelerating the back of the pulse. A spherical aberration associated with the electron inspection beam may be corrected. A substrate may be inspected with the combined electron inspection beam. The greater brightness of the combined electron inspection beam enhances the inspection throughput.

Description

High-brightness and low-energy pulsed electron source

The description in this article is generally about a high-brightness low-energy pulsed electron source.

The lithographic projection equipment can be used, for example, in the manufacture of integrated circuits (IC). Patterned devices (such as masks) can include or provide patterns corresponding to individual layers of the IC ("design layout"), and can be coated with radiation-sensitive materials (" The method of transferring the pattern to the target part (for example, containing one or more dies) on the substrate (for example, silicon wafer) of the layer of "resist"). Generally speaking, a single substrate contains a plurality of adjacent target portions, and the pattern is sequentially transferred to the plurality of adjacent target portions by the lithographic projection device, one target portion at a time. In one type of lithographic projection equipment, the pattern on the entire patterned device is transferred to a target part in one operation. This device is usually called a stepper. In an alternative device commonly referred to as a step-and-scan device, the projection beam scans across the patterned device in a given reference direction ("scanning" direction) while simultaneously moving the substrate parallel or anti-parallel to this reference direction. Different parts of the pattern on the patterned device are gradually transferred to a target part. Generally speaking, since the lithographic projection equipment will have a reduction ratio M (for example, 4), the speed F of the substrate movement will be 1/M times the speed of the projection beam scanning the patterned device. More information about lithographic devices can be found in, for example, US 6,046,792, which is incorporated herein by reference.

Before transferring the pattern from the patterned device to the substrate, the substrate may undergo various processes, such as priming, resist coating, and soft baking. After exposure, the substrate can undergo other processes ("post-exposure process"), such as post-exposure bake (PEB), development, hard bake, and measurement/inspection of the transferred pattern. This process array is used as the basis for manufacturing individual layers of devices (such as ICs). The substrate can then undergo various processes, such as etching, ion implantation (doping), metallization, oxidation, chemical mechanical polishing, etc., all of which are intended to finish individual layers of the device. If several layers are required in the device, the entire process or its variants are repeated for each layer. Eventually, the device will exist in every target part on the substrate. These devices are then separated from each other by techniques such as cutting or sawing, so that individual devices can be mounted on a carrier, connected to pins, etc.

Manufacturing devices such as semiconductor devices generally involves the use of several manufacturing processes to process substrates (eg, semiconductor wafers) to form the various features and multiple layers of the devices. Such layers and features are typically fabricated and processed using, for example, deposition, lithography, etching, chemical mechanical polishing, and ion implantation. Multiple devices can be fabricated on multiple dies on a substrate, and then these devices can be separated into individual devices. This device manufacturing process can be regarded as a patterning process. The patterning process involves a patterning step, such as optical and/or nanoimprint lithography that uses the patterning device in the lithography device to transfer the pattern on the patterned device to the substrate. The patterning process is usually but as appropriate One or more related pattern processing steps, such as resist development by a developing device, baking a substrate with a baking tool, etching with a pattern by an etching device, and the like.

Lithography is a central step in the manufacture of devices such as ICs, in which the patterns formed on the substrate define the functional elements of the device, such as microprocessors, memory chips, and so on. Similar lithography technology is also used in the formation of flat panel displays, microelectromechanical systems (MEMS) and other devices.

As the semiconductor manufacturing process continues to advance, the size of functional components has been continuously reduced. At the same time, the number of functional elements (such as transistors) per device has steadily increased, which follows a trend commonly referred to as "Moore's Law". In the current state of the art, lithographic projection equipment is used to fabricate the layers of the device. The lithographic projection equipment uses illumination from a deep ultraviolet source to project the design layout onto the substrate, resulting in a size much lower than 100 nm (that is, Individual functional elements that are smaller than half the wavelength of the radiation from the illumination source (for example, a 193 nm illumination source).

The printing size is smaller than the classic resolution limit of lithographic projection equipment. This procedure is usually called low-k1 lithography according to the resolution formula CD = k1×λ/NA, where λ is the wavelength of the radiation used (currently in large In most cases, it is 248nm or 193nm), NA is the numerical aperture of the projection optics in the lithographic projection equipment, CD is the "critical dimension" (usually the smallest feature size printed), and k1 is the empirical resolution factor. Generally speaking, the smaller the k1 is, the more difficult it is to reproduce a pattern similar to the shape and size planned by the designer in order to achieve specific electrical functionality and performance on the substrate. In order to overcome these difficulties, complex fine-tuning steps are applied to lithographic projection equipment, design layouts or patterned devices. For example, these steps include, but are not limited to, optimization of NA and optical coherence settings, customized lighting schemes, use of phase-shift patterning devices, and optical proximity correction (OPC, sometimes referred to as " Optical and procedural calibration”), or other methods generally defined as “resolution enhancement technology” (RET).

OPC and other RET use robust electronic models that describe the lithography process. Therefore, a calibration process for this type of lithography model is required, which provides an effective, stable and accurate model across the process window. Currently, a certain number of 1D and/or 2D gauge patterns with wafer measurement are used for calibration. More specifically, the one-dimensional gauge pattern includes line space patterns with varying pitch and critical dimension (CD), isolated lines, multiple lines, and the like. The 2-dimensional gauge pattern usually includes wire ends, contacts, and randomly selected static random access memory (SRAM) patterns.

Most of the context of the following invention and embodiments is in the context of a high-brightness low-energy dispersive pulsed electron source for semiconductor inspection. However, this should not be considered restrictive. There are other applications for the high-brightness, low-energy, pulsed electron source described herein, such as brain imaging (as an example). Therefore, the principles described in this article can be extended to other applications beyond semiconductor imaging. In addition, the principles described here can be extended to charged particles other than electrons only.

According to an embodiment, a high-brightness electron source system is provided. The system includes: a plurality of transmitters, which are configured to generate a corresponding plurality of pulses to form an electron beam; and a first radio frequency (RF) or microwave structure, which is configured to combine the plurality of pulses into an electron beam A combined electron beam is aligned along a single optical axis. The combined electron beam has a greater brightness than each of the individual pulse constituent electron beams.

In one embodiment, the first RF or microwave structure includes a deflection cavity.

In one embodiment, the system further includes: a combination of electro-optical elements configured to reduce the energy spread of the electron beam.

In one embodiment, the combination of the electro-optical element includes a second RF or microwave structure and a third RF or microwave structure, and the second RF or microwave structure and the third RF or microwave structure are separated by a drift space therebetween . The second RF or microwave structure is configured to increase the energy spread of an incoming electron pulse by accelerating a front part of the pulse and decelerating a back part of the pulse. The drift space is configured to stretch the pulse in time. The third RF or microwave structure is configured to monochromate the pulse by decelerating the front portion of the pulse and accelerating the back portion of the pulse. The signals used to drive the first RF or microwave structure, the second RF or microwave structure, and the third RF or microwave structure are synchronized with each other.

In one embodiment, the signals used to drive the first RF or microwave structure, the second RF or microwave structure, and/or the third RF or microwave structure include multiple high-order harmonics with the same microwave frequency The microwave signal linearizes a normal sinusoidal electromagnetic field inside a specific RF or microwave structure over time, thus approaching a sawtooth distribution.

In one embodiment, the second RF or microwave structure and the third RF or microwave structure include resonant cavities.

In one embodiment, the combination of electro-optical elements includes: a tortuous path configured to disperse the combined electron beam by energy level so that electrons with higher energy in the combined electron beam follow a Relatively short path, and electrons with lower energy in the combined electron beam follow a relatively long path; and an accelerator configured to accelerate the combined electron beam so that the combined electron beam has The electrons with the lower energy self-accelerate to obtain more energy than the electrons with the higher energy in the combined electron beam, so as to reduce the difference between the lower energy electrons and the higher energy electrons. One energy spread.

In one embodiment, the curved path is a track curve.

In one embodiment, the track curve includes a plurality of magnetic deflectors.

In one embodiment, the system further includes a multi-pole corrector configured to correct a spherical aberration associated with the combined electron beam.

In one embodiment, the multi-pole corrector includes at least one transfer lens, at least one adapter lens, at least one alignment deflector, a beam tilt coil, a beam shift coil, and at least one astigmatism compensator.

In one embodiment, the pulses of electrons in different ones of the plurality of pulses constituting the electron beams are out of phase with each other, so that the combined electron beam is formed by the combination of the out-of-phase pulses of an electron.

In one embodiment, the plurality of transmitters includes a plurality of Schottky transmitters or cold field transmitters.

According to one embodiment, a detection system configured to increase detection throughput is provided, wherein the system includes the high-brightness low-energy dispersive pulse electron source system described above.

According to another embodiment, a method for improving detection throughput is provided, the method comprising: generating a plurality of pulses to form an electron beam;

Use a deflection cavity to combine the plurality of pulse component electron beams into a combined electron detection beam, the combined electron detection beam has a greater brightness than each of the individual component pulse electron beams; the energy level is used to disperse the The combined electron detection beam enables the electrons with higher energy in the combined electron detection beam to guide the electrons with lower energy in the combined electron detection beam; and reduces the lower energy electrons and the higher An energy spread between energy electrons; wherein the combined electron inspection beam is configured for inspection of a substrate.

In one embodiment, the detection yield is a function of the brightness of the combined electron detection beam, and wherein the greater brightness of the combined electron detection beam increases the detection yield.

In one embodiment, the combined electron detection beam is aligned along a single optical axis.

In one embodiment, generating the plurality of pulses to form electron beams includes: emitting a plurality of continuous electron beams; and generating energy dispersion in individual beams of the plurality of continuous beams to generate similar energy in the individual beams The pulses of electrons form the plurality of pulses to form an electron beam.

According to an embodiment, there is provided a method for reducing the energy spread of a pulsed electron beam by increasing an incoming electron pulse by accelerating a front part of the pulse and decelerating a rear part of the pulse An energy spread; use a drift space to stretch the pulse in time; and monochromatize the pulse by decelerating the front part of the pulse and accelerating the back part of the pulse.

According to an embodiment, a method for improving detection throughput is provided. The method includes generating a plurality of pulses to form an electron beam, and combining the plurality of pulses to form an electron beam into a combined electron detection beam. The combined electron detection beam has a greater brightness than each of the individually composed pulsed electron beams. The combined electron inspection beam is configured to inspect a substrate.

In one embodiment, the detection output is a function of the brightness of the combined electron detection beam. The greater brightness of the combined electron inspection beam increases the inspection throughput.

In one embodiment, the combined electron detection beam is aligned along a single optical axis.

In one embodiment, the inspection throughput is associated with a semiconductor manufacturing process, and the substrate is associated with a semiconductor device.

In one embodiment, the pulses of electrons in different ones of the plurality of pulses constituting the electron beams are out of phase with each other, so that the combined electron detection beam is formed by a combination of the out-of-phase pulses of an electron.

In one embodiment, generating the plurality of pulses to form electron beams includes: emitting a plurality of continuous electron beams; and generating energy dispersion in individual beams of the plurality of continuous beams to generate similar energy in the individual beams The pulses of electrons form the plurality of pulses to form an electron beam.

In one embodiment, a deflection cavity is used to combine the plurality of pulses into the electron beam to form the combined electron detection beam.

In one embodiment, generating the plurality of pulses to form the electron beam includes emitting the plurality of pulses to form the electron beam by a corresponding plurality of Schottky emitters or cold field emitters. In one embodiment, the Schottky emitter is the most useful electron source for semiconductor inspection. For other applications, possible systems such as thermal emitters are better starting points, because they can deliver more current at lower brightness.

In one embodiment, the method further includes accelerating the combined electron detection beam to reduce the effect of coulomb interaction.

In one embodiment, the method further includes: dispersing the electrons in the combined electron detection beam by energy levels, so that the electrons with higher energy in the combined electron detection beam follow a relatively relatively large curve through an orbital curve. Short path, and electrons with lower energy in the combined electron detection beam follow a relatively long path through the orbital curve; and accelerate the combined electron detection beam so that the combined electron detection beam has the relatively long path The low-energy electrons self-accelerate to obtain more energy than the higher-energy electrons in the combined electron detection beam, so as to reduce the difference between the lower-energy electrons and the higher-energy electrons. Energy spread.

In one embodiment, the detection output is an inverse function of the energy dispersion, and reducing the energy dispersion further improves the detection output.

In one embodiment, dispersing the electrons in the combined electron detection beam by the energy level includes passing the combined electron detection beam through an orbital curve including a plurality of magnetic deflectors. In one embodiment, the track curve includes four magnetic deflectors.

In one embodiment, the acceleration is performed by an acceleration cavity.

In one embodiment, the energy level disperses the electrons in the combined electron detection beam and accelerates the combined electron detection beam to generate a monochromatic electron beam.

In one embodiment, the detection output is associated with bright field detection or multi-beam detection.

In one embodiment, the detection output is associated with a scanning electron microscope.

In one embodiment, the method further includes: generating the combined electron detection beam with a scanning electron microscope; and correcting a spherical aberration associated with the combined electron detection beam with a multi-pole corrector. In one embodiment, the detection yield is a function of correcting the spherical aberration, so that correcting the spherical aberration further improves the detection yield.

In one embodiment, the plurality of pulses forming the electron beam includes at least 10 pulses forming the electron beam.

According to another embodiment, a method for improving detection throughput is provided. The method includes: passing an electron detection beam through a curved path; when the electron detection beam traverses the curved path, dispersing the electron detection beam by energy level, so that the electrons with higher energy in the electron detection beam follow A relatively short path, and electrons with lower energy in the electron detection beam follow a relatively long path; and accelerating the electron detection beam, so that the electrons with the lower energy in the electron detection beam are faster than the The electrons having the higher energy in the electron detection beam obtain more energy by self-acceleration, so as to reduce an energy spread between the lower energy electrons and the higher energy electrons. The accelerated electron inspection beam is configured to inspect a substrate.

In one embodiment, the curved path includes a track curve.

According to another embodiment, a method for improving detection throughput is provided. The method includes: using a scanning electron microscope to generate an electron detection beam; and using a multi-pole corrector to correct a spherical aberration associated with the electron detection beam. The calibrated electron inspection beam is configured to inspect a substrate.

According to another embodiment, a computer program product is provided, which includes a non-transitory computer-readable medium having instructions recorded thereon. These instructions, when executed by a computer, perform any or all of the operations described above.

According to another embodiment, a detection system configured to increase detection throughput is provided. The system includes: a plurality of emitters, which are configured to generate a corresponding plurality of pulses to form an electron beam; and an electro-optical configuration, which is configured to combine the plurality of pulses to form an electron beam into a combined electron detection beam . The combined electron detection beam has a greater brightness than each of the individual pulse constituent electron beams. The combined electron inspection beam is configured to inspect a substrate.

In one embodiment, the electro-optical configuration includes a deflection cavity.

In one embodiment, the system further includes: a tortuous path configured to disperse the combined electron detection beam by energy levels so that electrons with higher energy in the combined electron detection beam follow a relative A shorter path, and electrons with lower energy in the combined electron detection beam follow a relatively long path; and an accelerator configured to accelerate the combined electron detection beam so that the combined electron detection beam The electrons having the lower energy in the combined electron detection beam obtain more energy from the acceleration than the electrons having the higher energy in the combined electron detection beam, so as to reduce the lower energy electrons and the higher energy electrons An energy spread between.

In one embodiment, the curved path is a track curve. In one embodiment, the track curve includes a plurality of magnetic deflectors.

In one embodiment, the accelerator includes an accelerating cavity.

In one embodiment, the system further includes a multi-pole corrector configured to correct a spherical aberration associated with the combined electron detection beam. In one embodiment, the multi-pole corrector includes at least one transfer lens, at least one adapter lens, at least one alignment deflector, a beam tilt coil, a beam shift coil, and at least one astigmatism compensator.

In one embodiment, the pulses of electrons in different ones of the plurality of pulses constituting the electron beams are out of phase with each other, so that the combined electron detection beam is formed by a combination of the out-of-phase pulses of an electron.

In an embodiment, the plurality of transmitters includes a plurality of Schottky transmitters or cold field transmitters.

In one embodiment, the detection system is a scanning electron microscope.

According to another embodiment, a detection system configured to increase detection throughput is provided. The system includes a curved path configured to disperse a combined electron detection beam by energy levels so that electrons with higher energy in the combined electron detection beam follow a relatively short path, and the The electrons with lower energy in the combined electron detection beam follow a relatively long path. The system includes an accelerator configured to accelerate the combined electron detection beam so that the electrons with the lower energy in the combined electron detection beam have the higher energy than those in the combined electron detection beam The energy of the electrons self-accelerate to obtain more energy, so as to reduce an energy spread between the lower energy electrons and the higher energy electrons. The combined electron inspection beam is configured to inspect a substrate.

In one embodiment, the curved path is a track curve. In one embodiment, the track curve includes a plurality of magnetic deflectors.

According to another embodiment, a scanning electron microscope inspection system configured to increase inspection throughput is provided. The system includes a multi-pole corrector configured to correct a spherical aberration associated with a combined electron detection beam. The combined electron inspection beam is configured to inspect a substrate.

In one embodiment, the multi-pole corrector includes at least one transfer lens, at least one adapter lens, at least one alignment deflector, a beam tilt coil, a beam shift coil, and at least one astigmatism compensator.

According to another embodiment, a high-brightness electron source system is provided. The system includes: a plurality of emitters, which are configured to generate a corresponding plurality of pulses to form an electron beam; and an electro-optical configuration, which is configured to combine the plurality of pulses to form an electron beam into a combined electron detection beam . The combined electron detection beam has a greater brightness than each of the individual pulse constituent electron beams.

In one embodiment, the electro-optical configuration includes a deflection cavity.

In one embodiment, the system further includes: a tortuous path configured to disperse the combined electron detection beam by energy levels so that electrons with higher energy in the combined electron detection beam follow a relative A shorter path, and electrons with lower energy in the combined electron detection beam follow a relatively long path; and an accelerator configured to accelerate the combined electron detection beam so that the combined electron detection beam The electrons having the lower energy in the combined electron detection beam obtain more energy from the acceleration than the electrons having the higher energy in the combined electron detection beam, so as to reduce the lower energy electrons and the higher energy electrons An energy spread between.

In one embodiment, the curved path is a track curve.

In one embodiment, the track curve includes a plurality of magnetic deflectors.

In one embodiment, the accelerator includes an accelerating cavity.

In one embodiment, the system further includes a multi-pole corrector configured to correct a spherical aberration associated with the combined electron detection beam.

In one embodiment, the multi-pole corrector includes at least one transfer lens, at least one adapter lens, at least one alignment deflector, a beam tilt coil, a beam shift coil, and at least one astigmatism compensator.

In one embodiment, the pulses of electrons in different ones of the plurality of pulses constituting the electron beams are out of phase with each other, so that the combined electron detection beam is formed by a combination of the out-of-phase pulses of an electron.

In an embodiment, the plurality of transmitters includes a plurality of Schottky transmitters or cold field transmitters.

Light (beam of light) is usually used for bright field defect detection as part of the semiconductor and/or integrated circuit manufacturing process. Advantageously, light-based inspection is a relatively fast process, and the output of light-based inspection generally does not limit the total manufacturing output. However, it is increasingly difficult to find ever smaller defects in manufactured semiconductors and/or other integrated circuit devices using light-based inspection techniques. This is because the size of the defects that can be detected by light-based technology is limited by the wavelength of the light used during the inspection.

Electron beam detection technology can be used as an alternative to light-based detection technology. The detection resolution of the electron beam is higher than the detection resolution of the beam. This is because there is no wavelength associated with the electron beam (the effective wavelength of the electron beam is smaller than that from the beam) and the electrons in the electron beam are compared with semiconductor devices and / Or other integrated circuits have relatively small features. Therefore, electron beam inspection technology can be used to find defects that cannot be detected by light-based technology. However, the past electron beam detection technology is slower than its light-based counterpart. Slow throughput times often hinder the use of previous electron beam inspection techniques.

In order to solve these and other shortcomings of the previous system, the present electron beam-based inspection system and method are configured to deliver (compared to the previous electron beam-based system) more beam current to the substrate while maintaining the electron beam-based The increased resolution of the detection system (compared to the light-based system). This in turn increases the detection throughput. The system and method are also configured to correct and/or otherwise reduce the energy spread in the electron detection beam, and to correct the spherical aberration in the electron detection beam. These operations also increase the throughput of inspections. Among these and other methods, the present system and method provide higher detection throughput compared to previous electron beam-based detection systems, and at the same time provide increased resolution compared to light-based detection.

When the electron beam is focused by an electromagnetic lens, the energy dispersion of the beam will cause chromatic aberration that fundamentally limits the resolution of the electron microscope. The energy filter monochromator can reduce the energy spread of the electron beam by using dispersive elements to spatially separate electrons of different energies and using small slits to select only the small monochromatic part of the beam (and therefore increase the resolution of the microscope) , But at the cost of current. Generally, the energy selective monochromator discards 90% to 99% of the current, which is unacceptable when throughput is important and at other times. In some embodiments, the system and method include two phase-locked time-dependent electromagnetic fields that are configured to reduce the energy spread of the pulsed electron beam without sacrificing current. In some embodiments, the system and method utilize track curves and accelerators, as described below. These examples are not intended to be limiting.

The present invention will now be described in detail with reference to the drawings, which are provided as illustrative examples of the present invention so that those skilled in the art can practice the present invention. It is worth noting that the following figures and examples are not intended to limit the scope of the present invention to a single embodiment, but to make other embodiments possible by virtue of the interchange of some or all of the described or illustrated elements. In addition, where known components can be used partially or completely to implement certain elements of the present invention, only those parts of such known components necessary for understanding the present invention will be described, and such known components will be omitted. Know the detailed description of other parts of the components so as not to obscure the present invention. Unless otherwise specified herein, it will be obvious to those familiar with the art that the embodiments described as being implemented in software should not be limited to this, but may include embodiments implemented in hardware or a combination of software and hardware. , And vice versa. In this specification, embodiments showing singular components should not be regarded as limiting; in fact, unless expressly stated otherwise herein, the present invention is intended to cover other embodiments including plural identical components, and vice versa. In addition, unless clearly stated as such, the applicant does not intend to attribute any term in this specification or the scope of the patent application to an uncommon or special meaning. In addition, the present invention covers current and future known equivalents of known components mentioned herein by way of explanation.

Although the manufacturing of semiconductor devices and/or other integrated circuits may be specifically referred to in this article, it should be clearly understood that the description in this article has many other possible applications. For example, it can be used to manufacture integrated optical systems, guide and detect patterns for magnetic domain memory, liquid crystal display panels, thin-film magnetic heads, etc. Those familiar with this technology should understand that in the context of such alternative applications, any use of the terms "reduced mask", "wafer" or "die" in this article should be regarded as separate and more general terms "Mask", "Substrate" and "Target Part" are interchanged.

In the present document, the terms "radiation" and "beam" are used to cover all types of electromagnetic radiation, including ultraviolet radiation (for example, having a wavelength of 365 nm, 248 nm, 193 nm, 157 nm or 126 nm) and extreme ultraviolet radiation (EUV, for example, has a wavelength in the range of about 5 nm to 100 nm).

The term "projection optics" as used herein should be broadly interpreted as covering various types of optical systems, including, for example, refractive optics, reflective optics, aperture, and catadioptric optics. The term "projection optics" may also include components that operate according to any of these design types for collectively or individually guiding, shaping, or controlling the projection radiation beam. The term "projection optics" can include any optical components in the lithographic projection equipment, no matter where the optical components are located in the optical path of the lithographic projection equipment. Projection optics may include optical components for shaping, conditioning, and/or projecting radiation from a source before it passes through a patterned device (e.g., semiconductor), and/or for shaping after the radiation passes through the patterned device. Optical components that shape, adjust and/or project the radiation. Projection optics usually do not include source and patterning devices.

The (e.g., semiconductor) patterned device may include or may form one or more design layouts. A computer-aided design (CAD) program can be used to generate the design layout. This program is commonly referred to as electronic design automation (EDA). Most CAD programs follow a set of predetermined design rules in order to produce functional design layout/patterned devices. Set these rules through processing and design constraints. For example, design rules define the space tolerance between devices (such as gates, capacitors, etc.) or interconnect lines in order to ensure that the devices or lines do not interact with each other in an undesired manner. Design rules may include and/or specify specific parameters, restrictions on parameters and/or parameter ranges, and/or other information. One or more of the design rule constraints and/or parameters can be referred to as "critical dimensions" (CD). The critical dimension of a device can be defined as the minimum width of a line or hole, or the minimum space between two lines or two holes, or other features. Therefore, CD determines the total size and density of the designed device. One of the goals in device manufacturing is to faithfully reproduce the original design intent on the substrate (via patterned devices).

The term "mask" or "patterned device" as used herein can be broadly interpreted as referring to a general-purpose semiconductor patterned device that can be used to impart a patterned cross-section to an incident radiation beam. Corresponds to the pattern to be produced in the target portion of the substrate; the term "light valve" can also be used in this context. In addition to classic masks (transmission or reflection; binary, phase shift, hybrid, etc.), other examples of such patterned devices include programmable mirror arrays and programmable LCD arrays.

An example of a programmable mirror array can be a matrix addressable surface with a viscoelastic control layer and a reflective surface. The basic principle underlying this device is (for example): the addressed area of the reflective surface reflects incident radiation as diffracted radiation, while the unaddressed area reflects incident radiation as non-diffracted radiation. Using a suitable filter, the non-diffracted radiation can be filtered out from the reflected beam, leaving only diffracted radiation; in this way, the beam becomes patterned according to the addressing pattern of the addressable surface of the matrix. Suitable electronic components can be used to carry out the required matrix addressing. Examples of programmable LCD arrays are given in US Patent No. 5,229,872, which is incorporated herein by reference.

As used herein, the term "patterning process" generally means the process of generating an etched substrate by applying a specified pattern of light as part of the lithography process. However, the "patterning process" may also include plasma etching, because many of the features described herein can provide the benefits of using plasma processing to form printed patterns.

As used herein, the term "target pattern" means an ideal pattern to be etched on the substrate.

As used herein, the term "printed pattern" means a physical pattern etched based on the target pattern on the substrate. The printed pattern may include, for example, grooves, channels, depressions, edges, or other two-dimensional and three-dimensional features produced by lithography procedures.

As used herein, the terms "predictive model" and/or "procedure model" (which can be used interchangeably) mean a model that includes one or more models that simulate a patterning process. For example, the prediction and/or process model may include (e.g., model the lens system/projection system used to deliver light in the lithography process and may include the final optical image of the light entering the photoresist). , (For example, model the physical effect of resist, such as the chemical effect attributed to light) resist model, and (for example, it can be used to manufacture target patterns and may include sub-resolution resist features (SRAF), etc.) The OPC model, and/or other models.

As used herein, the term "calibration" means to modify (e.g., improve or tune) and/or verify something, such as a program model.

As an introduction, FIG. 1 illustrates a diagram of various subsystems of an example lithographic projection apparatus 10A. The main components are: radiation source 12A, which can be a deep ultraviolet excimer laser source or other types of sources including extreme ultraviolet (EUV) sources (as discussed above, the lithographic projection device itself does not need to have a radiation source); illumination optics Devices, which, for example, define partial coherence (labeled as standard deviation) and which may include optical devices 14A, 16Aa, and 16Ab that shape the radiation from source 12A; patterned device 18A; and transmissive optical device 16Ac, which will pattern the device The image of the pattern is projected onto the substrate plane 22A. The adjustable filter or aperture 20A at the pupil plane of the projection optics can limit the range of beam angles impinging on the substrate plane 22A, where the largest possible angle defines the numerical aperture of the projection optics NA= n sin(Θ _max ), where n is the refractive index of the medium between the substrate and the last element of the projection optics, and Θ _max is the maximum angle of the light beam emitted from the projection optics that can still strike the substrate plane 22A.

In the lithographic projection equipment, the source provides illumination (that is, radiation) to the patterned device, and the projection optics guides and shapes the illumination onto the substrate via the patterned device. The projection optics may include at least some of the components 14A, 16Aa, 16Ab, and 16Ac. Aerial image (AI) is the radiation intensity distribution at the level of the substrate. The resist model can be used to calculate the resist image from the aerial image. An example of this can be found in US Patent Application Publication No. US 2009-0157630, the disclosure of which is hereby incorporated by reference in its entirety. The resist model is related to the properties of the resist layer (for example, the effects of chemical processes that occur during exposure, post-exposure bake (PEB), and development). The optical properties of lithographic projection equipment (such as the properties of lighting, patterning devices, and projection optics) dictate aerial images and can be defined in optical models. Since the patterned device used in the lithographic projection equipment can be changed, the optical properties of the patterned device need to be separated from the optical properties of the rest of the lithographic projection equipment including at least the source and projection optics. The details of the technology and model used to transform the design layout into various lithographic images (such as aerial images, resist images, etc.), use their technologies and models to apply OPC, and evaluate performance (such as based on process windows) are described in the United States Patent Application Publication Nos. US 2008-0301620, 2007-0050749, 2007-0031745, 2008-0309897, 2010-0162197, and 2010-0180251, the disclosure of each publication It is hereby incorporated by reference in its entirety.

It may be necessary to use one or more tools to produce results that can be used for patterning procedures such as design, control, monitoring, etc. It can provide one or more tools for computationally controlling and designing one or more aspects of patterning procedures, such as pattern design for patterned devices (including, for example, adding secondary resolution auxiliary features or optical proximity correction) ), used for lighting of patterned devices, etc. Therefore, in a system for computationally controlling, designing, etc., manufacturing procedures involving patterning, the manufacturing system components and/or procedures can be described by various functional modules and/or models. In some embodiments, an electronic (for example, mathematical, parametric, etc.) model describing one or more steps of the patterning process and/or one or more equipment may be provided. In some embodiments, one or more electronic models may be used to simulate the patterning process to simulate the patterning process using the design pattern provided by the patterned device to form the patterned substrate.

The manufactured device can be inspected at various points during manufacturing. FIG. 2 schematically depicts a generalized embodiment of the electron beam inspection device 50. In some embodiments, the inspection equipment may be an electron beam inspection equipment (e.g., scanning electron microscope (SEM)) that produces images of structures exposed or transferred on the substrate (e.g., some or all of the structures of devices such as integrated circuits). Same or similar). The primary electron beam 52 emitted from the electron source 54 is condensed by the condenser lens 56 and then passes through the beam deflector 58, the E×B deflector 60, and the objective lens 62 to irradiate the substrate 70 on the substrate stage ST at a focal point.

When the substrate 70 is irradiated with the electron beam 52, secondary electrons are generated from the substrate 70. The secondary electrons are deflected by the E×B deflector 60 and detected by the secondary electron detector 72. The two-dimensional electron beam image can be obtained by detecting the electrons generated from the sample synchronously with the following operations: for example, the beam deflector 58 makes the electron beam two-dimensional scanning or the beam deflector 58 makes the electron beam 52 in X Or it is repeatedly scanned in the Y direction, and the substrate 70 is continuously moved in the other of the X or Y directions by the substrate table ST. Therefore, in one embodiment, the electron beam detection device has a field of view for the electron beam defined by the angular range, and the electron beam within the angular range can be provided by the electron beam detection device (for example, the deflector 60 can provide the electron beam 52 of the corner). Therefore, the spatial extent of the field of view is the spatial extent that the angular path of the electron beam can impinge on the surface (where the surface can be stationary or move relative to the field).

As shown in FIG. 2, the signal detected by the secondary electronic detector 72 can be converted into a digital signal by an analog/digital (A/D) converter 74, and the digital signal can be sent to the image processing system 76. In one embodiment, the image processing system 76 may have a memory 78 for storing all or part of the digital image for processing by the processing unit 80. The processing unit 80 (for example, specially designed hardware or a combination of hardware and software or a computer-readable medium containing software) is configured to convert or process the digital image into a data set representing the digital image. In one embodiment, the processing unit 80 is configured or programmed to perform the operations described herein (such as SEM inspection). In addition, the image processing system 76 may have a storage medium 82 configured to store digital images and corresponding data sets in a reference database. The display device 84 can be connected to the image processing system 76, so that the operator can perform the necessary operations of the equipment by means of a graphical user interface.

Figure 3 schematically illustrates another embodiment of the detection device. The system is used to detect a sample 90 (such as a substrate) on a sample stage 89 and includes a charged particle beam generator 81, a condenser lens module 99, a probe forming objective lens module 83, and a charged particle beam deflection module 88 , Secondary charged particle detector module 85, image forming module 86 and/or other components. The charged particle beam generator 81 generates a primary charged particle beam 91. The condenser lens module 99 condenses the generated primary charged particle beam 91. The probe forming objective lens module 83 focuses the focused primary charged particle beam into a charged particle beam probe 92. The charged particle beam deflection module 88 scans the charged particle beam probe 92 formed by scanning across the surface of the region of interest on the sample 90 fastened on the sample stage 89. In some embodiments, the charged particle beam generator 81, the condenser lens module 83, and the probe forming objective lens module 83 or their equivalent designs, alternatives, or any combination thereof together form a scanning charged particle beam probe 92 The charged particle beam probe generator.

The secondary charged particle detector module 85 detects secondary charged particles 93 that are emitted from the surface of the sample after being bombarded by the charged particle beam probe 92 (may also be together with other reflected or scattered charged particles from the surface of the sample). A secondary charged particle detection signal 94 is generated. The image forming module 86 (such as a computing device) is coupled to the secondary charged particle detector module 85 to receive the secondary charged particle detection signal 94 from the secondary charged particle detector module 85 and correspondingly form at least one The scanned image. In one embodiment, the secondary charged particle detector module 85 and the image forming module 86 or their equivalent designs, alternatives, or any combination thereof together form an image forming device that is free of charged particle beam probes The detected secondary charged particles emitted by the sample 90 bombarded at 92 form a scanned image.

In one embodiment, the monitoring module 87 is coupled to the image forming module 86 of the image forming device to monitor, control, etc. the patterning process, and/or use the experience of the sample 90 received from the image forming module 86 Scan the image to derive parameters for pattern programming, control, monitoring, etc. In some embodiments, the monitoring module 87 is configured or programmed to perform the operations described herein. In some embodiments, the monitoring module 87 includes a computing device. In some embodiments, the monitoring module 87 includes a computer program configured to provide the functionality described herein. In some embodiments, the detection spot size of the electron beam in the system of FIG. 3 is significantly larger than that of, for example, CD, so that the detection spot is large enough so that the detection speed can be fast. However, the resolution may be lower due to the large detection spot.

The image from the system of, for example, FIG. 2 and/or FIG. 3 can be processed to extract the size, shape, outline, and/or other information describing the edge of the object representing the semiconductor device structure in the image. The shape, contour, and/or other information can be quantified through user-defined tangents and/or metrics in other positions (such as CD). In some embodiments, the image of the device structure is compared and the image of the device structure is quantified via metrics such as the edge-to-edge distance (CD) measured on the extracted contour or the simple pixel difference between the images. Alternatively, the metrics may include EP gauges and/or other parameters.

As described above, the present electron beam-based inspection system and method are configured so that (compared to the previous electron beam-based system) more beam current is delivered to the substrate while maintaining the electron beam-based inspection system (compared to Based on the increased resolution of the light-based system. This in turn increases output. The system and method are also configured to correct and/or otherwise reduce the energy spread in the electron detection beam, and to correct the spherical aberration in the electron detection beam. These operations also increase output. Among these and other methods, the present system and method provide higher detection throughput compared to previous electron beam-based detection systems, and at the same time provide increased resolution compared to light-based detection.

Figure 4 illustrates an example method 400 in accordance with one or more embodiments. The method 400 may be a method for improving the throughput of detection. In some embodiments, the detection output is associated with, for example, bright field detection or multi-beam detection. In some embodiments, the detection throughput is associated with a scanning electron microscope, the system of FIG. 2 and/or FIG. 3, and/or other systems. In some embodiments, one or more operations of the method 400 described below may be performed in one or more components of a scanning electron microscope or by one or more components of a scanning electron microscope. In some embodiments, the scanning electron microscope may form, for example, a detection system such as that described in FIGS. 2 and/or 3 and/or other detection systems. In some embodiments, the operations of the method 400 are performed for, for example, a semiconductor manufacturing process. In some embodiments, the inspection throughput is associated with the semiconductor manufacturing process, and one or more substrates are inspected. One or more substrates may be associated with, for example, semiconductor devices and/or other integrated circuits.

As shown in FIG. 4, the method 400 may include generating 402 pulses to form an electron beam, combining the pulses to form an electron beam 403 into a combined beam, dispersing parts of the combined beam by energy level 404, accelerating the combined beam 406, Correct 408 the spherical aberration of the combined beam, perform 410 detection with the combined beam, and/or other operations. These operations are described in more detail below.

The operations of the method 400 presented below are intended to be illustrative. In some embodiments, the method 400 may be implemented with one or more additional operations not described and/or without one or more of the operations discussed. In addition, the operations of the method 400 are illustrated in FIG. 4 and the order described below is not intended to be limiting.

In some embodiments, one or more parts of the method 400 may be implemented in one or more processing devices (for example, by simulation, modeling, electronically controlling one or more components of a scanning electron microscope, etc.). The one or more processing devices may include one or more devices that perform some or all of the operations of method 400 in response to instructions stored electronically on an electronic storage medium. The one or more processing devices may include one or more devices configured through hardware, firmware, and/or software, which are specifically designed to perform operations such as method 400 One or more.

The output associated with the electron beam detection system is limited by the current of the system electron detection beam, which is the difference between the individual beamlets in the system and the electron current in several beamlets (combined to form the electron detection beam) product. Some systems are limited in the number of thin beams they can provide, so it is not possible to increase throughput simply by adding more beams. Such systems may be limited in this way because the field size at the substrate (under inspection) is limited by field aberrations that can only be compensated to a certain extent by the aperture plate. The thin beams at the aperture plate must be separated to allow space for, for example, field aberration correction elements in the aperture plate.

。 在此方程式中，I為個別細光束中之電流，B_r 為源亮度，C_s 為球面像差係數，C_c 為與色像差相關聯之像差係數，V為光束能量，α為光束在基板處的開度角，d_spot 為細光束之直徑，且ΔV為細光束之能量散佈。如方程式所闡明，增加亮度、校正球面像差、校正色像差、減小能量散佈及/或其他操作提高(細光束及總系統電子檢測束之)電流，且繼而提高檢測產出量。變數d_spot 與應用相關聯，亦即，對於檢測大小x之缺陷，吾人需要光學解析度y，其中比x/y係恆定的。V為有限的，此係由於較高能量導致對基板之更多損壞性影響。C_c 可與C_S (如本文中所描述)極相同地校正，且此為減小ΔV的替代方案。下文所描述之方法400之操作經組態以增加電子檢測束之亮度、減小電子檢測束中之能量散佈、校正與電子檢測束相關聯之球面像差，及/或具有增加系統光束電流之其他效應(且因此提高產出量)。As an alternative to simply adding more beamlets (which is usually impossible, as described above), the properties of existing beamlets can be improved. For example, according to the following equation, the current in the thin beam is determined by the brightness of the electron source, beam aberration, Coulomb interaction and other factors:

. In this equation, I is the current in the individual beamlets, B _r is the source brightness, C _s is the spherical aberration coefficient, C _c is the aberration coefficient associated with the chromatic aberration, V is the beam energy, and α is the beam At the opening angle of the substrate, d _spot is the diameter of the thin beam, and ΔV is the energy dispersion of the thin beam. As the equation clarifies, increasing the brightness, correcting spherical aberration, correcting chromatic aberration, reducing energy spread, and/or other operations increase the current (of the thin beam and the total system electron detection beam), and then increase the detection output. The variable d _{spot is} related to the application, that is, for detecting defects of size x, we need an optical resolution y, where the ratio x/y is constant. V is limited, which is due to higher energy which causes more damaging effects on the substrate. C _c can _{be corrected exactly the same as C S} (as described herein), and this is an alternative to reducing ΔV. The operation of the method 400 described below is configured to increase the brightness of the electron detection beam, reduce the energy spread in the electron detection beam, correct the spherical aberration associated with the electron detection beam, and/or have the ability to increase the system beam current Other effects (and therefore increase output).

For example, for detection at the 2nm node, a ^{throughput of 1000 mm 2} /hour requires a total beam current of 9 μA at the substrate level. This would require 9000 thin beams in the previous system, which is not suitable for the current 100-400 thin beam maximums of this type of system. In contrast, for the same requirements, this system and/or method facilitates the use of only 121 (ie, 11×11 small beams), which is indeed suitable for the current 100-400 beamlet system design . (In this example, using this system and method, forty sources can be combined (as described below) and the associated energy spread and Cs can be reduced by 50%.)

Brightness (for example, B _r in the above equation) can be increased by adding multiple sources together to generate a new source with the same emissivity (area times the solid angle of emission), and the total current is the sum of all sources . In some embodiments, operations 402, 403, and/or other operations may help increase the source brightness.

The method 400 includes generating 402 a plurality of pulses to form an electron beam. In some embodiments, the plurality of pulses forming the electron beam includes at least 2, 5, 10, or more pulses forming the electron beam. In some embodiments, the pulses of electrons in different ones of the multiple pulses forming the electron beam are out of phase with each other.

For example, in some embodiments, generating a plurality of pulses to form an electron beam includes: emitting a plurality of continuous electron beams; The pulses of electrons form a plurality of pulses to form an electron beam. The electron beam composed of a plurality of pulses can be generated by, for example, a corresponding number of emitters. The transmitter may be included in, and/or associated with, a scanning electron microscope and/or other systems, for example. In some embodiments, generating a plurality of pulses to form an electron beam includes emitting a plurality of pulses from a corresponding plurality of Schottky emitters or cold field emitters to form an electron beam, and then (for example, using a buncher cavity and/or other components) Generate energy dispersion in individual beams in a plurality of continuous beams to generate pulses of electrons with similar energy in the individual beams to form a plurality of pulses to form an electron beam.

This is illustrated in Figures 5 and 6. FIG. 5 illustrates an example of a Schottky transmitter 500. Schottky emitters can be advantageous because they are associated with relatively high brightness and relative stability compared to other emitters. The transmitter 500 includes an electron source needle 502, a suppressor 504, an extractor 506, and a focusing anode 508. As shown in FIG. 5, energy 510 (such as a laser) is focused on the tip 512 of the electron source needle 502, which releases electrons (e ⁻ ) in response to absorbing at least some of the energy 510. The suppressor 504 is configured to concentrate the field strength on the tip of the needle. The extractor 506 is configured to pull the emitted electrons from the tip of the needle. The focusing anode 508 is configured to focus the extracted electrons. Figure 5 illustrates a pulsed Schottky transmitter. It should be noted that when a buncher cavity is used, a continuous firing Schottky transmitter can be used, for example. The present invention is intended to cover both embodiments. In addition, in some embodiments, the Schottky emitter is the most useful electron source for semiconductor inspection. For other applications, possible systems such as thermal emitters are better starting points, because they can deliver more current at lower brightness.

FIG. 6 illustrates an example of a buncher cavity 600. As shown in FIG. The buncher cavity 600 is configured to generate energy dispersion in individual electron beams (such as the electron beam shown in FIG. 5) to generate pulses of electrons with similar energy in the individual beams to form a plurality of pulses to form the electron beam. The bunching cavity 600 may include an electron source 602 (for example, it may be similar and/or the same as the emitter 500 shown in FIG. 5), an accelerator 604, a first resonant cavity 606 (with input 607) forming a buncher 608, The second resonant cavity 610 (with output 611) of the trap 612 and the trap 614 are formed. The accelerator 604 can be configured to accelerate the electrons in the electron beam, for example, to reduce the effect of Coulomb interaction. Coulomb interaction is the effect of electrons repelling each other because they are all negatively charged. The result is a blur of the light spot: it magnifies the size of the probe to be the same as the aberration pole. The effect is more serious when the electron density is higher (I) or when it travels slower (V). The collector 614 may be, for example, an anode plate and/or formed by other components. In some embodiments, the anode may have a hole in the center so that electrons can pass through its path to the substrate. In some embodiments, there may be a feedback path 620 between the cavity 610 and the cavity 606. As shown in Figure 6, the buncher 608 is configured to generate a bunch 650 of bunched (or pulsed) electrons. For example, the speed change of individual electrons can be introduced by time-varying acceleration in the buncher cavity 600. After the drift space, the electrons are grouped in bunches. Potential stray electrons can be blocked by the second cavity 610. In some embodiments, the cavity is a "box" in which a radio frequency electric field is generated. The orientation of the field is such that it alternates in the same direction as the electron flow through the "box". The electrons in the box will gain extra energy at the moment the field strength is pointing forward to the maximum, so they will travel faster than the average. The electrons in the box at the moment when the field strength is pointed backward to the maximum will gain lower energy, so they will travel more slowly than the average. The velocity changes between the electrons will produce bunching.

In some embodiments, a plurality of Schottky emitters (such as 500 shown in FIG. 5) and/or a corresponding buncher cavity (such as 600 shown in FIG. 6) are used to generate a plurality of individual pulses to form electrons bundle. In some embodiments, as described above, the plurality of pulses forming the electron beam includes at least 2, 5, 10, or more pulses forming the electron beam. This means that there may be, for example, 2 sets, 5 sets, 10 sets or more sets of Schottky emitters and/or buncher cavities. In some embodiments, the individual pulses forming the electron beam may have a frequency of, for example, about 130 MHz. Bunches with a duration of about 10 pc can be generated at intervals of about 7.7 ns at this frequency. These examples are not intended to be limiting. In some embodiments, the Schottky emitter and/or buncher cavity are configured such that the pulses of electrons in different ones of the multiple pulses that make up the electron beam are out of phase with each other. For example, the timing of the pulses of the electrons in different ones of the multiple pulses forming the electron beam does not match the timing of the other pulses of the electrons in the other beams. This is achieved by appropriately phasing the RF field in the beams buncher cavity associated with the various beams.

It should be noted that in some embodiments, the buncher cavity 600 may not be necessary. The reality is that, for example, the energy (e.g., laser) guided at the tip (e.g., 512) of the electron source needle (e.g., 502) shown in FIG. 5 can be pulsed to generate electrons in an electron beam from a given source. Pulse flow.

Returning to FIG. 4, the method 400 includes combining the pulses into electron beams and combining 403 into a combined electron detection beam. The combined electron detection beam is formed by the combination of out-of-phase pulses of electrons. The combined electron detection beam has a greater brightness than each of the individually composed pulsed electron beams. In some embodiments, the (e.g., first) radio frequency (RF) or microwave structure (such as a deflection cavity) is configured to combine a plurality of pulses into electron beams into a combined electron beam. As described above, the detection output is a function of the brightness of the combined electron detection beam. The greater brightness of the combined electron inspection beam improves inspection throughput. For example, since B _r is positive and appears on the right-hand side of the equation shown above, any increase in brightness produces a corresponding increase in current (I). As described above, increasing the current improves the detection throughput.

The combined electron inspection beam can be configured to inspect substrates and/or other objects. For example, the combined electron inspection beam can be a scanning electron microscope inspection beam. The substrate can be, for example, a semiconductor device and/or part of another substrate. In some embodiments, an electron optical configuration and/or other components are used to combine a plurality of pulses into electron beams into a combined electron detection beam. The electro-optical configuration may include, for example, deflection cavities and/or other devices.

The buncher cavity is described above. The deflection cavity differs in the sense that the electrons travel through the box perpendicular to the direction of the RF electric field. The result is that the deflection will be different as a function of time. In some embodiments, the combined electron detection beam is aligned along a single optical axis.

FIG. 7 illustrates combining the pulses into electron beams 1 to 11 and combining 403 into a combined electron detection beam 700. The combined electron detection beam 700 is oriented along a single optical axis 701, for example. As shown in FIG. 7, the combined electron detection beam 700 is formed by the combination of out-of-phase pulses 702 to 726 of electrons. In this example, once combined, the pulses of electrons 702 to 726 can have an interval 752 of about 0.77 ns (which corresponds to a frequency of 1.3 GHz). This is only an example. The combined electron detection beam 700 has a greater brightness than each of the individually composed pulsed electron beams 1-11. In some embodiments, an electron optical configuration and/or other components are used to combine a plurality of pulses into electron beams 1 to 11 into a combined electron detection beam 700. The electro-optical configuration may include, for example, a deflection cavity 750 (e.g., a first RF or microwave structure) and/or other devices.

Returning to Figure 4, according to the above equation, reducing the energy spread (such as ΔV in the above equation) in the combined electron detection beam (such as the 700 shown in Figure 7) also increases the current (I) and therefore improves the detection output quantity. For example, the detection output is the inverse function of the energy dispersion, and reducing the energy dispersion further improves the detection output. In some embodiments, operations 404, 406, and/or other operations may help reduce energy spread in the combined electron detection beam.

As described above, the method 400 is configured to reduce the energy spread of the combined electron beam. This can be done with a combination of electro-optical components and/or other components. For example, the method 400 includes the portion of the combined electron detection beam by energy level dispersion 404. The electrons in the electron detection beam combined by the energy level dispersion 404 may include passing the electrons through a tortuous path (such as an electro-optical element) and/or other dispersion operations. The curved path may be, for example, an orbital curve, and/or other devices configured to disperse electrons in the electron beam by energy levels. In some embodiments, dispersing the electrons in the combined electron detection beam by the energy level includes passing the combined electron detection beam through an orbital curve including a plurality of magnetic deflectors. In some embodiments, the track curve contains two, three, four, or more magnetic deflectors. In some embodiments, the electrons in the combined electron detection beam are dispersed by the energy level, so that the electrons with higher energy in the combined electron detection beam follow a relatively short path through orbital curves, and the combined electron detection beam The electrons with lower energy in the orbital curve follow a relatively long path. After the orbital curve, the electrons form a bunch based on their energy level.

By way of non-limiting example, FIG. 8 illustrates a portion 800 of the electron detection beam 700 combined by energy level dispersion 404. A part 800 of the combined electron detection beam 700 may be, for example, an electron beam with energy spread. The electrons in the portion 800 may pass through a tortuous path 802, for example. The curved path 802 may be, for example, an orbital curve, and/or other devices configured to disperse electrons in the electron beam by energy levels. The orbital curve may include a plurality of magnetic deflectors and/or be formed by a plurality of magnetic deflectors. In this example, the track curve can be formed by four magnetic deflectors, but this is not intended to be limiting. In some embodiments, the electrons in the portion 800 are dispersed by the energy level, so that the electrons 850 in the portion 800 with higher energy follow a relatively short path 852 through the orbital curve, and the electrons with lower energy in the portion 800 854 follows a relatively long path 856 via a track curve. (One or more other groups of electrons 858 may also follow one or more other paths 860 via a track curve). After the orbital curve, the electrons form a bunch based on their energy level. In this example, electrons 850, 854, and 858 are shown as vertical separation 870.

Returning to FIG. 4, the method 400 includes accelerating 406 a combined electron detection beam (e.g., 700 shown in FIG. 7). The combined electron detection beam can be accelerated to reduce the effect of Coulomb interaction and/or for other reasons. Accelerate the combined electron detection beam 406 is configured so that electrons with lower energy in the combined electron detection beam gain more energy than electrons with higher energy in the combined electron detection beam, so as to reduce the lower Energy spread between energy electrons and higher energy electrons. In other words, the electrons in the combined electron detection beam can be accelerated off-crest, which means that the lower-energy electrons in a given electron bunch receive more energy than the higher-energy electrons in the bunch. The result is that the energy change between the electrons in the bunch is smaller. In some embodiments, the energy level disperses the electrons in the combined electron detection beam and accelerates the combined electron detection beam to generate a monochromatic electron beam.

In some embodiments, acceleration can be performed by an acceleration cavity (such as an electro-optical device) and/or other components. In some embodiments, the speed change of individual electrons can be introduced by time-varying acceleration. In some embodiments, the acceleration is provided by a cavity or by a DC electric field provided by the same electrode as the extractor pole in the Schottky source. The acceleration cavity may comprise a box with an RF field and/or be formed by a box with an RF field through which electrons travel. Because it is bunched, the electrons in the bunch will get the same "sudden jump" from the electric field. When the frequency of the bunching matches the frequency of the RF field, the bunching will be accelerated equally.

By way of non-limiting example, FIG. 8 also illustrates the acceleration 406 of the combined electron detection beam 700. In this example, accelerating the combined electron detection beam 700 is performed by the accelerating cavity 868. The combined electron detection beam acceleration 406 is configured so that the electrons with lower energy in the combined electron detection beam 700 (e.g., 858) are self-accelerating than the electrons with higher energy in the combined electron detection beam 700 (e.g., 850) Get more energy in order to reduce the energy spread between lower-energy electrons and higher-energy electrons. In some embodiments, the energy level disperses the electrons in the combined electron detection beam and accelerates the combined electron detection beam to generate a monochromatic electron beam 870.

Returning to FIG. 4, in some embodiments, the method 400 includes correcting 408 the spherical aberration of the combined beam (for example, C _s in the above equation). In some embodiments, for example, the method 400 includes generating a combined electron detection beam using a scanning electron microscope (eg, according to the operations described above); and correcting spherical aberrations associated with the combined electron detection beam. In some embodiments, the detection output is a function of correcting the spherical aberration (for example, as shown in the above equation), so that the correction of the spherical aberration further increases the current (I) and the detection output.

Multipole correctors and/or other devices can be used to correct spherical aberrations. The multi-pole corrector can be a series of lenses, deflectors, magnetic coils, and/or other components configured to correct aberrations in the combined electron detection beam. In some embodiments, the multi-pole corrector includes at least one transfer lens, at least one adapter lens, at least one alignment deflector, beam tilt coil, beam shift coil, at least one astigmatism compensator, and/or other Components.

For example, FIG. 9 illustrates an example of the multi-pole corrector 901. In the example shown in FIG. 9, the multi-pole corrector includes a six-pole corrector, but other types of multi-pole correctors are considered. As shown in FIG. 9, the multi-pole corrector 901 includes a condenser lens 900, a beam tilt coil 902, a beam shift coil 904, an adapter lens 906, hexapole elements 908 and 910, transfer lenses 912, 914, 916 and 918, alignment deflectors 920, 922, 924, 926 and 928, astigmatism compensators 930 and 932, and other components. FIG. 9 also illustrates the sample plane 940, the beam 942, the axial line 944, and the field line 946 between the condenser lens 900 and the sample plane 940. In some embodiments, the beam 942 may be similar and/or the same as the combined electron detection beam 700 shown in the previous figures.

Returning to FIG. 4, in some embodiments, the method 400 includes performing 410 inspection with a combined electron inspection beam (e.g., 700 shown in FIG. 7). The 410 inspection with the combined electron inspection beam is configured to increase inspection throughput. As described above, in some embodiments, the detection output is associated with, for example, bright-field detection or multi-beam detection. In some embodiments, the detection throughput is associated with a scanning electron microscope and/or other systems. In some embodiments, operation 410 may be performed for, for example, semiconductor and/or other integrated circuit manufacturing processes. In some embodiments, the inspection throughput is associated with the semiconductor manufacturing process, and one or more substrates are inspected. One or more substrates may be associated with, for example, semiconductor devices and/or other integrated circuits.

For example, FIG. 10 illustrates the detection of a 410 sample 1050 using a combined electron detection beam 700. FIG. 10 illustrates an example multi-beam detection system 1052. The multi-beam detection system 1052 may include a source 1054, a source multiplier 1056, a first projection system 1058, a second projection system 1060, a detector 1062, and/or other components. The combined electron detection beam 700 and the system 1052 are used to perform 410 detection and are configured to increase the detection output of the sample 1050 detection. As described above, in some embodiments, the detection throughput is associated with bright-field detection rather than multi-beam detection as shown here. In some embodiments, the system 1052 can be used for, for example, semiconductor and/or other integrated circuit manufacturing process inspection. In some embodiments, the inspection throughput is associated with the semiconductor manufacturing process, and one or more substrates such as the sample 1050 are inspected. The sample 1050 may be associated with, for example, semiconductor devices and/or other integrated circuits. It should be noted that FIG. 10 is only an example, and represents the ability to interface the high-brightness electron source described herein with several different electron beam systems.

Returning to FIG. 4, in some embodiments, operations 404 (e.g., dispersion) and 406 (e.g., acceleration) and/or other operations may be a combination of electro-optical elements (such as additional (e.g., second and third) RF or microwave structures) It is configured to reduce the energy spread of the combined electron beam. In some embodiments, the combination of electro-optical elements includes second and third RF or microwave structures, and the second and third RF or microwave structures are separated by a drift space therebetween. In these embodiments, the second RF or microwave structure is configured to increase the energy spread of the incoming electron pulse by accelerating the front part of the pulse and decelerating the back part of the pulse; the drift space is configured to stretch in time Pulse; and the third RF or microwave structure is configured to monochromatize the pulse by decelerating the front part of the pulse and accelerating the back part of the pulse.

In some embodiments, the signals used to drive the first RF or microwave structure (such as the deflection cavity described above), the second RF or microwave structure, and the third RF or microwave structure are synchronized with each other. In some embodiments, in order to reduce the energy spread of the pulses in the combined beam, the resonant frequency of the second and third RF or microwave structures (e.g., cavities) may be higher than the first (e.g., deflected) RF or microwave structure (e.g., The resonant frequency of the cavity, for example, the number of electron sources multiplied by the resonant frequency of the first cavity. (Note that if f1-f2 = n f1, where n is an integer multiple, the two frequencies f1 and f2 can be synchronized.) The second and third RF or microwave structures may include, for example, resonant cavities and/or other structures. These can be, for example, microwave cavities and/or other structures. In some embodiments, the signal used to drive the first, second, and/or third RF or microwave structure includes microwave signals with multiple high-order harmonics of the same microwave frequency, so that the normal sine inside the individual RF or microwave structure The electromagnetic field is linearized with time, so as to approach a sawtooth distribution.

In accelerator physics, _{the sinusoidal longitudinal electric field of the microwave cavity in the TM 010} mode can be used to modulate the energy distribution of the electron beam, which generates the time modulation after the drift space. These cavities can be used to accelerate, compress and monochromatize electron pulses. Higher-order harmonics can be used to expand the linear part of the sinusoidal electromagnetic field, thereby increasing the maximum time working range of these cavities. In this system and method, the linear part of the microwave field can be expanded by so many high-order harmonics, so that the field in the cavity is close to a perfect sawtooth, thereby stretching at the microwave period of the cavity T = 1/resonant frequency.

In some embodiments, the combined beam can propagate along (for example) the positive z-axis, passing through two of these fully linearized phase-locked TM ₀₁₀ cavities (for example, the second and third RF or microwave structures), respectively It has longitudinal focal lengths f ₁ and f ₂ , separated by a drift space (see between 406 and 408 in Fig. 4) L = f ₁ + f ₂ ( f ₁ can be negatively selected). The second (stretching) cavity (RF or microwave structure) can be configured to adjust the energy distribution of the electron beam as a function of time into a sawtooth distribution periodicity with a microwave period T. The electrons passing through the same microwave period are called "pulses." Although they are directly behind the cavity, all the pulses are still adjacent to each other in time (and therefore the combined beam can be regarded as continuous).

(Note that when the microwave sawtooth causes a negative dE/dt correlation in the (E,t)-phase space, the electrons in the front of each pulse will experience a negative momentum jump, and the electrons in the back of each pulse will experience positive momentum Sudden jump. This will generate a time-modulated beam (such as a pulsed beam without sacrificial current) in the longitudinal focus (compression point) of the cavity.)

且因此與按時間相鄰之脈衝(部分地)重疊。儘管光束看起來係連續的，但字脈衝將繼續使用，此係由於脈衝仍在縱向相空間中分離。由於脈衝在時間上拉伸，故不相關能量散佈因縱向發射度之守恆而減小。The truth is that, in some embodiments, the (second RF or microwave structure) cavity is configured such that it introduces a positive (periodic) dE/dt correlation to the electrons. During the drift, the pulse will stretch the factor in time

And therefore overlap (partially) with pulses that are adjacent in time. Although the beam appears to be continuous, the word pulse will continue to be used because the pulse is still separated in the longitudinal phase space. Since the pulse is stretched in time, the uncorrelated energy spread is reduced due to the conservation of longitudinal emittance.

。為了維持均一時間分佈(穩定電流)，拉伸因子

應選擇為正整數。TM₁₁₀ 腔亦在橫向方向上具有透鏡屬性。然而，可使用聚焦電子光學器件來校正橫向效應。The light beam then propagates through a third RF or microwave structure, which may be formed by, for example, a monochromatic cavity. The phase and longitudinal focus of the cavity are configured so that the cavity field slows down the front part of each pulse and accelerates the back part of each pulse so that all electrons in the pulse have approximately the same energy. In this way, the dE/dt correlation (and related energy spread) is removed, and the phase space density collapses onto the t-axis. Since the duration of each pulse has been increased, and the longitudinal emittance (~Δ t Δ E ) of each pulse is conserved, the energy spread of each pulse (and the entire beam) will reduce the stretching factor

. In order to maintain a uniform time distribution (stable current), the stretch factor

Should be selected as a positive integer. The TM ₁₁₀ cavity also has lens properties in the lateral direction. However, focusing electron optics can be used to correct for lateral effects.

By way of non-limiting example, Figure 11 illustrates a longitudinal beam expander 1101 using microwave cavities (e.g., second and third RF or microwave structures, such as TM ₀₁₀ cavities, 1100, and 1102). The cavity 1100 is configured to stretch the beam 1104, and the cavity 1102 is configured to monochromatize the beam 1104, as described above. The cavity 1100 and the cavity 1102 are separated by a drift space 1106 (having a length L) therebetween. The light beam 1104 spreads into the cavity 1100 with a shorter pulse width and higher energy, and spreads out of the cavity 1102 with a longer pulse width and lower energy. The transition from shorter pulse width and higher energy spread to longer pulse width and lower energy spread is also shown on the energy (E) versus time (t) graphs 1108, 1110, 1112, 1114, and 1116. For example, the graph 1108 (which corresponds to the point where the beam 1104 enters the cavity 1100) illustrates a relatively short pulse width 1109 and a relatively high energy dispersion 1111. By the time the beam 1104 leaves the cavity 1102, the pulse width 1109 is relatively long and the energy spread 1111 is relatively low (as shown by the overlapping lines in the graph 1116). For ease of understanding, associating FIG. 11 with FIG. 4, the cavity 1100 (for example, the second RF or microwave structure) performs operation 404, and the cavity 1102 (for example, the third RF or microwave structure) performs operation 406.

判定，其在實踐中藉由第一腔中之最大同軸電場振幅及漂移空間之長度判定。TM₀₁₀ 腔之最小縱向焦距藉由下述者給出：

, 其中e為基本電荷，E ₀ 為腔中之同軸電場振幅，L_c 為有效腔長度，ω 為腔之角諧振頻率，m_e 為電子質量，γ 為相對論勞侖茲因子且v_z 為電子之速度。

之電場振幅可經應用，例如僅要求43W之微波功率(同樣，作為實例)以用於Ω形腔。將微波功率外推至例如1 kW，使得電場振幅為

。 與L_c = 6 mm、ω=2π×3 GHz及30 kV電子組合，此產生|f |=6 mm之最小焦距。則L = 10 cm之腔間漂移空間將使得

=17.5 ×能量散佈之減小。L = 1 m之腔間漂移空間將使得

=175 ×能量散佈之減小。 此等實例並不意欲為限制性的。With the help of practical examples, the energy spread is reduced by the stretch factor

It is determined in practice by the maximum coaxial electric field amplitude in the first cavity and the length of the drift space. The minimum longitudinal focal length of the TM _{010 cavity is given by:}

, Where e is the fundamental charge, E ₀ is the coaxial electric field amplitude in the cavity, L _c is the effective cavity length, ω is the angular resonance frequency of the cavity, m _e is the electron mass, γ is the relativistic Lorentz factor and v _z is the electron The speed.

The electric field amplitude can be applied, for example, only 43W of microwave power is required (again, as an example) for the Ω-shaped cavity. Extrapolate the microwave power to, for example, 1 kW, so that the electric field amplitude is

. Combined with L _c = 6 mm, ω=2π×3 GHz and 30 kV electrons, this produces a minimum focal length of | f | = 6 mm. Then the drift space between the cavities of L = 10 cm will make

=17.5 × the reduction of energy spread. The drift space between the cavities of L = 1 m will make

=175 × the reduction of energy spread. These examples are not intended to be limiting.

Figure 12 is a diagram of an example computer system CS that can be used for one or more of the operations described herein. The computer system CS includes a bus BS or other communication mechanism for communicating information, and a processor PRO (or multiple processors) coupled with the bus BS to process information. The computer system CS also includes a main memory MM, such as a random access memory (RAM) or other dynamic storage devices, which is coupled to the bus BS for storing information and instructions to be executed by the processor PRO. The main memory MM can also be used to store temporary variables or other intermediate information during the execution of instructions by the processor PRO. The computer system CS further includes a read-only memory (ROM) ROM or other static storage device coupled to the bus BS for storing static information and instructions for the processor PRO. A storage device SD such as a magnetic disk or an optical disk is provided, and the storage device SD is coupled to the bus BS for storing information and commands.

The computer system CS can be coupled to a display DS for displaying information to the computer user via the bus BS, such as a cathode ray tube (CRT), or a flat panel or touch panel display. The input device ID including alphanumeric characters and other keys is coupled to the bus BS for transmitting information and command selection to the processor PRO. Another type of user input device is a cursor control element CC for transmitting direction information and command selection to the processor PRO and for controlling the movement of the cursor on the display DS, such as a mouse, a trackball or a cursor direction button. The input device usually has two degrees of freedom on two axes (the first axis (for example x) and the second axis (for example y)), which allows the device to specify the position in the plane. The touch panel (screen) display can also be used as an input device.

In some embodiments, part of one or more of the methods described herein can be performed by the computer system CS in response to the processor PRO to execute one or more sequences of one or more instructions contained in the main memory MM . Such instructions can be read from another computer-readable medium (such as the storage device SD) into the main memory MM. The execution of the instruction sequence included in the main memory MM causes the processor PRO to perform the program steps (operations) described herein. One or more processors in a multi-processing configuration can also be used to execute the sequence of instructions contained in the main memory MM. In some embodiments, hard-wired circuitry can be used instead of or in combination with software commands. Therefore, the description in this article is not limited to any specific combination of hardware circuit system and software.

The term "computer-readable medium" as used herein refers to any medium that participates in providing instructions to the processor PRO for execution. This media can take many forms, including but not limited to non-volatile media, volatile media, and transmission media. Non-volatile media includes, for example, optical discs or magnetic discs, such as storage devices SD. Volatile media includes dynamic memory, such as main memory MM. Transmission media includes coaxial cables, copper wires and optical fibers, including wires including busbars BS. The transmission medium can also be in the form of sound waves or light waves, such as those generated during radio frequency (RF) and infrared (IR) data communications. Computer-readable media can be non-transitory, such as floppy disks, flexible disks, hard disks, tapes, any other magnetic media, CD-ROM, DVD, any other optical media, punch cards, paper tape, Any other physical media with hole patterns, RAM, PROM and EPROM, FLASH-EPROM, any other memory chips or cassettes. The non-transitory computer-readable medium may have instructions recorded on it. These instructions can perform any of the operations described herein when executed by a computer. Transitory computer-readable media may include, for example, carrier waves or other propagated electromagnetic signals.

Various forms of computer-readable media may involve carrying one or more sequences of one or more instructions to the processor PRO for execution. For example, the command can be initially carried on the disk of the remote computer. The remote computer can load commands into its dynamic memory, and use a modem to send commands through the telephone line. The modem at the local end of the computer system CS can receive the data on the telephone line, and use an infrared transmitter to convert the data into an infrared signal. The infrared detector coupled to the bus BS can receive the data carried in the infrared signal and place the data on the bus BS. The bus BS carries data to the main memory MM, and the processor PRO retrieves and executes commands from the main memory MM. The instructions received by the main memory MM may be stored on the storage device SD before or after being executed by the processor PRO, depending on the situation.

The computer system CS may also include a communication interface CI coupled to the bus BS. The communication interface CI provides a two-way data communication coupling with the network link NDL, which is connected to the local area network LAN. For example, the communication interface CI can be an integrated services digital network (ISDN) card or a modem to provide a data communication connection with a corresponding type of telephone line. As another example, the communication interface CI may be a local area network (LAN) card that provides a data communication connection with a compatible LAN. A wireless link can also be implemented. In any such implementation, the communication interface CI sends and receives electrical, electromagnetic, or optical signals that carry digital data streams representing various types of information.

The network link NDL usually provides data communication to other data devices via one or more networks. For example, the network link NDL can provide a connection to the host computer HC via a local area network LAN. This may include the provision of data communication services via the global packet data communication network (now commonly referred to as the "Internet" INT). The local area network LAN (Internet) can use electrical, electromagnetic or optical signals that carry digital data streams. The signals through various networks and the signals on the network data link NDL and through the communication interface CI are exemplary carrier forms for conveying information. These signals carry digital data to and from the computer system CS. The digital data.

The computer system CS can send messages and receive data (including code) via the network, network data link NDL, and communication interface CI. In the Internet example, the host computer HC can transmit the requested code for the application program via the Internet INT, the network data link NDL, the local area network LAN, and the communication interface CI. One such downloaded application can provide, for example, all or part of the methods described in this article. The received program code can be executed by the processor PRO when it is received, and/or stored in the storage device SD or other non-volatile storage for later execution. In this way, the computer system CS can obtain application code in the form of a carrier wave.

Fig. 13 is a schematic diagram of a lithography projection device according to an embodiment. The lithographic projection equipment may include an illumination system IL, a first object table MT, a second object table WT, and a projection system PS. The illumination system IL can adjust the radiation beam B. In this example, the lighting system also includes a radiation source SO. The first object stage (for example, the patterned device stage) MT can be provided with a patterned device holder for holding the patterned device MA (for example, a reduction mask), and is connected to accurately position the patterned device relative to the article PS. The first locator of the device. The second object table (for example, the substrate table) WT can be provided with a substrate holder for holding the substrate W (for example, a resist-coated silicon wafer), and is connected to the second object table for accurately positioning the substrate relative to the article PS. Locator. The projection system (e.g., it includes a lens) PS (e.g., a refractive, reflective, or catadioptric optical system) can image the irradiated portion of the patterned device MA onto the target portion C (e.g., including one or more dies) of the substrate W . For example, the patterned device alignment marks M1, M2 and the substrate alignment marks P1, P2 can be used to align the patterned device MA and the substrate W.

As depicted, the device may be of the transmissive type (ie, have a transmissive patterning device). However, in general, it can also be of, for example, a reflective type (with reflective patterned devices). The equipment can use different types of patterned devices used for classic masks; examples include programmable mirror arrays or LCD matrixes.

A source SO (such as a mercury lamp or excimer laser, a laser generating plasma (LPP) EUV source) generates a radiation beam. For example, this light beam is fed into the illumination system (illuminator) IL directly or after having traversed adjustment members such as a beam expander or beam delivery system BD (including guide mirrors, beam expanders, etc.). The illuminator IL may include an adjustment member AD for setting the outer radial range and/or the inner radial range of the intensity distribution in the light beam (usually referred to as σouter and σinner, respectively). In addition, the illuminator IL will generally include various other components, such as an accumulator IN and a condenser CO. In this way, the beam B impinging on the patterned device MA has the desired uniformity and intensity distribution in its cross section.

In some embodiments, the source SO may be inside the housing of the lithographic projection device (this is usually the case when the source SO is, for example, a mercury lamp), but it can also be far away from the lithographic projection device. For example, the radiation beam generated can be guided into the device (for example by means of a suitable guiding mirror). The latter case may be, for example, the case when the source SO is an excimer laser (e.g., based on KrF, ArF, or F2 laser action).

The light beam B can then intercept the patterned device MA held on the patterned device table MT. Having traversed the patterned device MA, the light beam B can pass through the lens PL, which focuses the light beam B onto the target portion C of the substrate W. With the help of the second positioning member (and the interferometric measurement member IF), the substrate table WT can be accurately moved, for example, to position different target parts C in the path of the beam B. Similarly, the first positioning member can be used to accurately position the patterned device MA relative to the path of the beam B, for example, after the patterned device MA is mechanically retrieved from the patterned device library or during scanning. Generally speaking, the movement of the object table MT and WT can be realized by means of a long-stroke module (coarse positioning) and a short-stroke module (fine positioning). However, in the case of a stepper (as opposed to a step-and-scan tool), the patterned device table MT may be connected to a short-stroke actuator, or may be fixed.

The drawn tool can be used in two different modes (step mode and scan mode). In the step mode, the patterned device stage MT remains substantially stationary, and the entire patterned device image is projected onto the target portion C in one operation (ie, a single "flash"). The substrate table WT can be shifted in the x and/or y direction, so that different target parts C can be irradiated by the light beam B. In scanning mode, basically the same situation applies, the difference is that the given target part C is not exposed in a single "flash". In fact, the patterned device stage MT can move in a given direction (for example, the "scan direction" or the "y" direction) at a speed v, so that the projection beam B scans across the image of the patterned device. At the same time, the substrate table WT moves simultaneously in the same or opposite direction at a speed of V = Mv, where M is the magnification of the lens (usually M = 1/4 or 1/5). In this way, a relatively large target portion C can be exposed without compromising the resolution.

Figure 14 is a schematic diagram of another lithographic projection device (LPA). The LPA may include a source collector module SO, an illumination system (illuminator) IL configured to adjust the radiation beam B (for example, EUV radiation), a support structure MT, a substrate table WT, and a projection system PS. The support structure (e.g., patterned device stage) MT can be constructed to support the patterned device (e.g., mask or reduction mask) MA and connected to a first positioner PM configured to accurately position the patterned device . The substrate table (e.g., wafer table) WT can be configured to hold a substrate (e.g., a resist coated wafer) W, and is connected to a second positioner PW configured to accurately position the substrate. The projection system (e.g., reflective projection system) PS can be configured to project the pattern imparted to the radiation beam B by the patterning device MA onto the target portion C (e.g., including one or more dies) of the substrate W.

As shown in this example, LPA can be of a reflective type (for example, using reflective patterned devices). It should be noted that since most materials are absorptive in the EUV wavelength range, the patterned device may have a multilayer reflector including multiple stacks of molybdenum and silicon, for example. In one example, the multi-stack reflector has 40 layer pairs of molybdenum and silicon, where the thickness of each layer is a quarter wavelength. X-ray lithography can be used to generate even smaller wavelengths. Since most materials are absorptive at EUV and X-ray wavelengths, a thin piece of patterned absorbing material (such as TaN absorbing material on the top of a multilayer reflector) defining features on the patterned device configuration will be printed (positive type) Resist) or not printed (negative resist).

The illuminator IL can receive the extreme ultraviolet radiation beam from the source collector module SO. Methods for generating EUV radiation include, but are not necessarily limited to, using one or more emission lines in the EUV range to convert a material with at least one element (such as xenon, lithium, or tin) into a plasma state. In one such method (commonly referred to as laser-generated plasma ("LPP")), the fuel can be irradiated with a laser beam (such as droplets, streams, or clusters of materials with line-emitting elements). Generate plasma. The source collector module SO may be part of an EUV radiation system including a laser (not shown in FIG. 10) for providing a laser beam for exciting fuel. The resulting plasma emits output radiation (such as EUV radiation), which is collected using a radiation collector arranged in a source collector module. For example, when a CO2 laser is used to provide a laser beam for fuel excitation, the laser and the source collector module can be separate entities. In this example, the laser may not be considered to form a part of the lithography device, and the radiation beam may be transferred from the laser to the source collector module by means of a beam delivery system including, for example, a suitable guiding mirror and/or beam expander. Group. In other examples, for example, when the source is a discharge-generating plasma EUV generator (commonly referred to as a DPP source), the source may be an integral part of the source collector module.

The illuminator IL may include an adjuster for adjusting the angular intensity distribution of the radiation beam. Generally, at least the outer radial extent and/or the inner radial extent (commonly referred to as σouter and σinner, respectively) of the intensity distribution in the pupil plane of the illuminator can be adjusted. In addition, the illuminator IL may include various other components, such as a faceted field mirror device and a faceted pupil mirror device. The illuminator can be used to adjust the radiation beam to have the desired uniformity and intensity distribution in its cross section.

The radiation beam B can be incident on a patterned device (such as a mask) MA held on a support structure (such as a patterned device table) MT, and be patterned by the patterned device. After being reflected from the patterned device (eg, mask) MA, the radiation beam B passes through the projection system PS, which focuses the beam onto the target portion C of the substrate W. With the aid of the second positioner PW and the position sensor PS2 (for example, an interferometric device, a linear encoder or a capacitive sensor), the substrate table WT can be accurately moved (for example, so that different target parts C are positioned between the radiation beams B). Path). Similarly, the first positioner PM and the other position sensor PS1 can be used to accurately position the patterned device (such as a mask) MA relative to the path of the radiation beam B. The patterned device alignment marks M1, M2 and the substrate alignment marks P1, P2 can be used to align the patterned device (for example, the mask) MA and the substrate W.

The depicted device LPA can be used in at least one of the following modes: step mode, scan mode, and static mode. In the stepping mode, the support structure (for example, the patterned device stage) MT and the substrate stage WT remain substantially stationary, and at the same time, the entire pattern imparted to the radiation beam is projected onto the target portion C at one time (for example, a single static exposure). Then, the substrate table WT is shifted in the X and/or Y direction, so that different target portions C can be exposed. In the scanning mode, the support structure (such as the patterned device stage) MT and the substrate stage WT are simultaneously scanned, and the pattern imparted to the radiation beam is projected onto the target portion C (ie, a single dynamic exposure). The speed and direction of the substrate table WT relative to the support structure (such as the patterned device table) MT can be determined by the magnification (reduction ratio) and image reversal characteristics of the projection system PS. In the stationary mode, the support structure (for example, the patterned device stage) MT holding the programmable patterned device remains substantially stationary, and moves or scans the substrate stage WT, and at the same time projects the pattern imparted to the radiation beam onto the target portion C . In this mode, a pulsed radiation source is usually used, and the programmable patterned device is updated as necessary after each movement of the substrate table WT or between successive radiation pulses during scanning. This mode of operation can be easily applied to unmasked lithography using programmable patterned devices, such as programmable mirror arrays of the type mentioned above.

Fig. 15 is a detailed view of the lithographic projection device shown in Fig. 14. As shown in FIG. 15, the LPA may include a source collector module SO, an illumination system IL, and a projection system PS. The source collector module SO is configured such that a vacuum environment can be maintained in the enclosure structure 220 of the source collector module SO. The EUV radiation emitting plasma 210 can be formed by generating a plasma source by discharge. The EUV radiation can be generated by gas or steam (such as Xe gas, Li steam or Sn steam), in which thermoplasma 210 is generated to emit radiation in the EUV range of the electromagnetic spectrum. The thermoplasma 210 is generated by, for example, a discharge that generates at least partially ionized plasma. Xe, Li, Sn steam or any other suitable gas or steam with a partial pressure of 10 Pa, for example, may be required for efficient generation of radiation. In some embodiments, a plasma of excited tin (Sn) is provided to generate EUV radiation.

The radiation emitted by the thermoplasma 210 passes through a gas barrier or pollutant trap 230 (also called a pollutant barrier or foil trap) located in or behind the opening in the source chamber 211 as appropriate. Transfer from the source chamber 211 to the collector chamber 212. The contaminant trap 230 may include a channel structure. The pollutant trap 230 may also include a gas barrier or a combination of a gas barrier and a channel structure. The pollutant trap or pollutant barrier 230 (described below) also includes a channel structure. The collector chamber 211 may include a radiation collector CO, which may be a grazing incidence collector. The radiation collector CO has an upstream radiation collector side 251 and a downstream radiation collector side 252. The radiation traversing the collector CO can be reflected from the grating filter 240 to be focused in the virtual source point IF along the optical axis indicated by the line "O". The virtual source point IF is generally referred to as an intermediate focus, and the source collector module is configured such that the intermediate focus IF is located at or near the opening 221 in the enclosure 220. The virtual source point IF is an image of the radiation emission plasma 210.

The radiation then traverses the illumination system IL, which may include a faceted field mirror device 22 and a faceted pupil mirror device 24 configured to provide the desired angle of the radiation beam 21 at the patterned device MA Distribution, and the desired uniformity of the radiation intensity at the patterned device MA. After the radiation beam 21 is reflected at the patterned device MA held by the support structure MT, a patterned beam 26 is formed, and the patterned beam 26 is imaged by the projection system PS through the reflective elements 28, 30 to the substrate table WT. On the substrate W. More elements than shown can generally be present in the illumination optics unit IL and the projection system PS. Depending on the type of lithography equipment, for example, a grating filter 240 may be present. In addition, there may be more mirrors than those shown in the drawings. For example, there may be 1 to 6 additional reflective elements in the projection system PS than the reflective elements shown in FIG. 14.

The collector optics CO as illustrated in FIG. 15 is depicted as a nested collector with grazing incidence reflectors 253, 254, and 255, only as an example of collectors (or collector mirrors). The grazing incidence reflectors 253, 254, and 255 are arranged to be axially symmetrical about the optical axis O, and this type of collector optics CO can be used in combination with a discharge generating plasma source commonly referred to as a DPP source.

Figure 16 is a detailed view of the source collector module SO of the lithographic projection equipment LPA (shown in the previous figure). The source collector module SO can be part of the LPA radiation system. The laser LA may be configured to deposit laser energy into a fuel such as xenon (Xe), tin (Sn), or lithium (Li), thereby generating a highly ionized plasma 210 with an electron temperature of tens of eV. The high-energy radiation generated during the de-excitation and recombination of the plasma is emitted from the plasma, collected by the near-normal incidence collector optics CO, and focused on the opening 221 in the enclosure structure 220.

The following items can be used to further describe the embodiments: 1. A method for improving the detection output, the method includes: Generate multiple pulses to form an electron beam; and Combining the plurality of pulse component electron beams into a combined electron detection beam, the combined electron detection beam having a greater brightness than each of the individual component pulse electron beams; The combined electron inspection beam is configured to inspect a substrate. 2. The method of clause 1, wherein the detection output is a function of the brightness of the combined electron detection beam, and wherein the greater brightness of the combined electron detection beam increases the detection output. 3. The method as in Clause 1 or 2, wherein the combined electron detection beam is aligned along a single optical axis. 4. The method according to any one of items 1 to 3, wherein the inspection output is associated with a semiconductor manufacturing process, and the substrate is associated with a semiconductor device. 5. The method according to any one of clauses 1 to 4, wherein the pulses of electrons in different ones of the plural pulses constituting the electron beams are out of phase with each other, so that the combined electron detection beam is out of phase by one electron The combination of pulses is formed. 6. The method of any one of items 1 to 5, wherein generating the plurality of pulses to form an electron beam includes: Emit a plurality of continuous electron beams; and Energy dispersion is generated in the individual beams of the plurality of continuous beams to generate pulses of electrons with similar energy in the individual beams to form the plurality of pulses to form an electron beam. 7. The method according to any one of items 1 to 6, wherein a deflection cavity is used to combine the plurality of pulses into electron beams into the combined electron detection beam. 8. The method according to any one of clauses 1 to 7, wherein generating the plurality of pulses to form an electron beam includes emitting the plurality of pulses to form an electron beam by a corresponding plurality of Schottky emitters or cold field emitters. 9. The method of any one of items 1 to 8, which further comprises accelerating the combined electron detection beam to reduce the effect of Coulomb interaction. 10. The method of any one of clauses 1 to 9, which further includes: The electrons in the combined electron detection beam are dispersed by the energy level so that the electrons with higher energy in the combined electron detection beam follow a relatively short path through an orbital curve, and the combined electron detection beam has Lower energy electrons follow a relatively long path through the orbital curve; and Accelerating the combined electron detection beam makes the electrons with the lower energy in the combined electron detection beam obtain more energy from self-acceleration than the electrons with the higher energy in the combined electron detection beam, so that Reduce an energy spread between the lower energy electrons and the higher energy electrons. 11. The method of clause 10, wherein the detection output is an inverse function of the energy dispersion, and wherein reducing the energy dispersion further increases the detection output. 12. The method of clause 10 or 11, wherein dispersing the electrons in the combined electron detection beam by energy level includes passing the combined electron detection beam through an orbital curve including a plurality of magnetic deflectors. 13. The method of Clause 12, wherein the orbital curve contains four magnetic deflectors. 14. The method according to any one of clauses 10 to 13, wherein the acceleration is performed by an acceleration chamber. 15. The method according to any one of clauses 10 to 14, wherein the electrons in the combined electron detection beam are dispersed by the energy level and the combined electron detection beam is accelerated to generate a monochromatic electron beam. 16. The method according to any one of clauses 1 to 15, wherein the detection output is associated with bright field detection or multi-beam detection. 17. The method according to any one of clauses 1 to 16, wherein the detection output is associated with a scanning electron microscope. 18. The method of any one of clauses 1 to 17, wherein the method further comprises: Use a scanning electron microscope to generate the combined electron inspection beam; and A multipole corrector is used to correct a spherical aberration associated with the combined electron detection beam. 19. The method of clause 18, wherein the detection yield is a function of correcting the spherical aberration, so that correcting the spherical aberration further improves the detection yield. 20. The method according to any one of clauses 1 to 19, wherein the plurality of pulses forming an electron beam includes at least 10 pulses forming an electron beam. 21. A method for increasing the throughput of testing, the method includes: Make an electron detection beam pass through a curved path; When the electron detection beam traverses the curved path, the energy level is used to disperse the electron detection beam, so that the electrons with higher energy in the electron detection beam follow a relatively short path, and the electron detection beam has a lower path. Energy electrons follow a relatively long path; and The electron detection beam is accelerated so that the electrons with the lower energy in the electron detection beam obtain more energy from the self-acceleration than the electrons with the higher energy in the electron detection beam, so as to reduce the comparison. An energy spread between low-energy electrons and the higher-energy electrons. The accelerated electron inspection beam is configured to inspect a substrate. 22. The method of clause 21, wherein the curved path includes a track curve. 23. A method for increasing the throughput of testing, the method includes: Use a scanning electron microscope to generate an electron detection beam; and Using a multi-pole corrector to correct a spherical aberration associated with the electron detection beam; The calibrated electron inspection beam is configured to inspect a substrate. 24. A computer program product comprising a non-transitory computer-readable medium with instructions recorded thereon, which, when executed by a computer, implement the method according to any one of items 1 to 23. 25. A detection system configured to increase detection output, the system includes: A plurality of emitters, which are configured to generate a corresponding plurality of pulses to form an electron beam; and An electron optical configuration configured to combine the plurality of pulse constituent electron beams into a combined electron detection beam, the combined electron detection beam having a greater brightness than each of the individual pulse constituent electron beams; The combined electron inspection beam is configured to inspect a substrate. 26. The system of clause 25, wherein the electro-optical configuration includes a deflection cavity. 27. The system of clause 25 or 26, which further comprises: a curved path configured to disperse the combined electron detection beam by energy level, so that the combined electron detection beam has a higher energy The electrons follow a relatively short path, and the electrons with lower energy in the combined electron detection beam follow a relatively long path; and An accelerator configured to accelerate the combined electron detection beam so that the electrons with the lower energy in the combined electron detection beam are higher than the electrons with the higher energy in the combined electron detection beam The electrons self-accelerate to obtain more energy, so as to reduce an energy spread between the lower-energy electrons and the higher-energy electrons. 28. Such as the system of item 27, wherein the curved path is a track curve. 29. Such as the system of Clause 28, wherein the orbital curve contains a plurality of magnetic deflectors. 30. The system of any one of clauses 27 to 29, wherein the accelerator includes an accelerating cavity. 31. The system of any one of clauses 25 to 30, which further includes a multi-pole corrector configured to correct a spherical aberration associated with the combined electron detection beam. 32. The system of clause 31, wherein the multi-pole corrector includes at least one transfer lens, at least one adapter lens, at least one alignment deflector, a beam tilt coil, a beam shift coil, and at least one image Dispersion compensator. 33. The system according to any one of clauses 25 to 32, wherein the pulses of electrons in different ones of the plurality of pulses constituting the electron beams are out of phase with each other, so that the combined electron detection beam is out of phase by one electron The combination of pulses is formed. 34. The system according to any one of clauses 25 to 33, wherein the plurality of transmitters includes a plurality of Schottky transmitters or cold field transmitters. 35. The system of any one of clauses 25 to 34, wherein the detection system is a scanning electron microscope. 36. A detection system configured to increase detection output, the system includes: A curved path configured to disperse a combined electron detection beam by energy levels, so that electrons with higher energy in the combined electron detection beam follow a relatively short path, and the combined electron detection beam The electrons with lower energy follow a relatively long path; and An accelerator configured to accelerate the combined electron detection beam so that the electrons with the lower energy in the combined electron detection beam are higher than the electrons with the higher energy in the combined electron detection beam The electrons self-accelerate to obtain more energy, so as to reduce an energy spread between the lower-energy electrons and the higher-energy electrons; The combined electron inspection beam is configured to inspect a substrate. 37. The system as in Clause 36, wherein the curved path is a track curve. 38. The system as in Clause 37, wherein the orbital curve includes a plurality of magnetic deflectors. 39. A scanning electron microscope inspection system configured to increase inspection output, the system includes: A multi-pole corrector configured to correct a spherical aberration associated with a combined electron detection beam, wherein the combined electron detection beam is configured for detection of a substrate. 40. The system of clause 39, wherein the multi-pole corrector includes at least one transfer lens, at least one adapter lens, at least one alignment deflector, a beam tilt coil, a beam shift coil, and at least one image Dispersion compensator. 41. A high-brightness electron source system, which includes: A plurality of emitters, which are configured to generate a corresponding plurality of pulses to form an electron beam; and An electron optical configuration configured to combine the plurality of pulse constituent electron beams into a combined electron detection beam, the combined electron detection beam having a greater brightness than each of the individual pulse constituent electron beams. 42. The system of clause 41, wherein the electro-optical configuration includes a deflection cavity. 43. The system of item 41 or 42, which further comprises: a curved path configured to disperse the combined electron detection beam by energy level, so that the combined electron detection beam has a higher energy The electrons follow a relatively short path, and the electrons with lower energy in the combined electron detection beam follow a relatively long path; and An accelerator configured to accelerate the combined electron detection beam so that the electrons with the lower energy in the combined electron detection beam are higher than the electrons with the higher energy in the combined electron detection beam The electrons self-accelerate to obtain more energy, so as to reduce an energy spread between the lower-energy electrons and the higher-energy electrons. 44. The system of item 43, wherein the curved path is a track curve. 45. The system of Clause 44, wherein the orbital curve contains a plurality of magnetic deflectors. 46. The system of any one of clauses 43 to 45, wherein the accelerator includes an accelerating cavity. 47. The system of any one of clauses 41 to 46, further comprising a multi-pole corrector configured to correct a spherical aberration associated with the combined electron detection beam. 48. The system of clause 47, wherein the multi-pole corrector includes at least one transfer lens, at least one adapter lens, at least one alignment deflector, a beam tilt coil, a beam shift coil, and at least one image Dispersion compensator. 49. The system according to any one of clauses 41 to 49, wherein the pulses of electrons in different ones of the plurality of pulses constituting the electron beams are out of phase with each other, so that the combined electron detection beam is out of phase by one electron The combination of pulses is formed. 50. The system according to any one of clauses 41 to 49, wherein the plurality of transmitters includes a plurality of Schottky transmitters or cold field transmitters. 51. A high-brightness electron source system, which includes: A plurality of emitters, which are configured to generate a corresponding plurality of pulses to form an electron beam; and A first radio frequency (RF) or microwave structure, which is configured to combine the plurality of pulses into electron beams into a combined electron beam aligned along a single optical axis, and the combined electron beams are smaller than the individual pulses Each of the beams has a greater brightness. 52. The system of clause 51, wherein the first RF or microwave structure includes a deflection cavity. 53. Such as the system of item 51 or 52, which further includes: A combination of electro-optical elements configured to reduce the energy spread of the electron beam. 54. The system of any one of clauses 51 to 53, wherein the combination of the electro-optical element includes a second RF or microwave structure and a third RF or microwave structure, the second RF or microwave structure and the third RF or The microwave structure is separated by the drift space in between, where: The second RF or microwave structure is configured to increase the energy spread of an incoming electron pulse by accelerating a front part of the pulse and decelerating a back part of the pulse; The drift space is configured to stretch the pulse in time; The third RF or microwave structure is configured to monochromatize the pulse by decelerating the front portion of the pulse and accelerating the back portion of the pulse; and The signals used to drive the first RF or microwave structure, the second RF or microwave structure, and the third RF or microwave structure are synchronized with each other. 55. The system of any one of clauses 51 to 54, wherein the signals used to drive the first RF or microwave structure, the second RF or microwave structure, and/or the third RF or microwave structure include The microwave signals with multiple high-order harmonics of the same microwave frequency linearize a normal sinusoidal electromagnetic field inside a specific RF or microwave structure over time, thus approaching a sawtooth distribution. 56. The system of any one of clauses 51 to 55, wherein the second RF or microwave structure and the third RF or microwave structure comprise resonant cavities. 57. The system of any one of clauses 51 to 53, wherein the combination of the electro-optical elements includes a curved path configured to disperse the combined electron beam by energy level so that the combined electron beam The electrons with higher energy in the electron beam follow a relatively shorter path, and the electrons with lower energy in the combined electron beam follow a relatively longer path; and An accelerator configured to accelerate the combined electron beam so that the electrons with the lower energy in the combined electron beam self-accelerate than the electrons with the higher energy in the combined electron beam More energy is obtained in order to reduce an energy spread between the lower energy electrons and the higher energy electrons. 58. The system of item 57, wherein the curved path is a track curve. 59. The system of item 58, wherein the orbital curve contains a plurality of magnetic deflectors. 60. The system of any one of clauses 51 to 59, further comprising a multi-pole corrector configured to correct a spherical aberration associated with the combined electron beam. 61. The system of clause 60, wherein the multi-pole corrector includes at least one transfer lens, at least one adapter lens, at least one alignment deflector, a beam tilt coil, a beam shift coil, and at least one image Dispersion compensator. 62. The system according to any one of clauses 51 to 61, wherein the pulses of electrons in different ones of the plurality of pulses constituting the electron beams are out of phase with each other, so that the combined electron beam is driven by the out-of-phase pulses of an electron The combination is formed. 63. The system according to any one of clauses 51 to 62, wherein the plurality of transmitters includes a plurality of Schottky transmitters or cold field transmitters. 64. A detection system configured to increase detection output, wherein the system includes a high-brightness, low-energy, pulsed electron source system such as any one of items 51 to 63. 65. A method for increasing the throughput of testing, the method includes: Generate multiple pulses to form an electron beam; Using a deflection cavity to combine the plurality of pulse component electron beams into a combined electron detection beam, the combined electron detection beam has a greater brightness than each of the individual component pulse electron beams; Dispersing the combined electron detection beam by the energy level, so that the electrons with higher energy in the combined electron detection beam guide the electrons with lower energy in the combined electron detection beam; and Reduce an energy spread between the lower energy electrons and the higher energy electrons; The combined electron inspection beam is configured to inspect a substrate. 66. The method of clause 65, wherein the detection yield is a function of the brightness of the combined electron detection beam, and wherein the greater brightness of the combined electron detection beam increases the detection yield. 67. The method of any one of clauses 65 to 66, wherein the combined electron detection beam is aligned along a single optical axis. 68. The method of any one of clauses 65 to 67, wherein generating the plurality of pulses to form an electron beam comprises: Emit a plurality of continuous electron beams; and Energy spread is generated in the individual beams of the plurality of continuous beams to generate pulses of electrons with similar energy in the individual beams to form the plurality of pulses to form an electron beam. 69. A method for reducing the energy spread of a pulsed electron beam by: increasing the energy spread of an incoming electron pulse by accelerating the front part of the pulse and decelerating the back part of the pulse ; Use a drift space to stretch the pulse in time; and monochromatize the pulse by decelerating the front part of the pulse and accelerating the back part of the pulse. 70. A computer program product comprising a non-transitory computer-readable medium with instructions recorded thereon, which, when executed by a computer, implement the method according to any one of items 65 to 69.

The concepts disclosed herein can simulate or mathematically model any general imaging system for imaging sub-wavelength features, and can be used especially for emerging imaging technologies capable of generating shorter and shorter wavelengths. Emerging technologies include the ability to generate 193nm wavelength by using ArF lasers and even extreme ultraviolet (EUV) and DUV lithography with a wavelength of 157nm by using fluorine lasers. In addition, EUV lithography can generate a wavelength in the range of 20nm to 50nm by using a synchrotron or by striking a material (solid or plasma) with high-energy electrons in order to generate photons in this range.

Although the concepts disclosed herein can be used for wafer manufacturing on substrates such as silicon wafers, it should be understood that the concepts disclosed can be used for any type of manufacturing system (for example, for manufacturing on substrates other than silicon wafers). The manufacturing system) is used. In addition, combinations and sub-combinations of the disclosed elements may include separate embodiments. For example, a separate embodiment of the method described herein may include one or more of a beam generating component, a beam combining component, a track curve, an acceleration component, a corrector component, and/or other components. As another example, any or all of these components can be combined in a single embodiment.

The above description is intended to be illustrative and not restrictive. Therefore, the system that will be obvious to those familiar with the technology can be modified as described without departing from the scope of the patent application explained below.

1: Pulse composition electron beam 2: Pulse composition electron beam 3: Pulse composition electron beam 4: Pulse composition electron beam 5: Pulse composition electron beam 6: Pulse composition electron beam 7: Pulse composition electron beam 8: Pulse composition electron beam 9: Pulse composition electron beam 10: pulse composition electron beam 10A: lithographic projection equipment 11: pulse composition electron beam 12A: radiation source/source 14A: optical device 16Aa: optical device 16Ab: optical device 16Ac: transmission optics 18A: patterned device 20A: Adjustable filter or aperture 21: Radiation beam 22: Faceted field mirror device 22A: Substrate plane 24: Faceted pupil mirror device 26: Patterned beam 28: Reflective element 30: Reflective element 50: Electron beam inspection equipment 52: primary electron beam/electron beam 54: electron source 56: condenser lens 58: beam deflector 60: E×B deflector/deflector 62: objective lens 70: substrate 72: secondary electron detection 74: analog/digital converter 76: image processing system 78: memory 80: processing unit 81: charged particle beam generator 82: storage medium 83: probe formation objective lens module 84: display device 85: secondary charged particles Detector module 86: Image forming module 87: Monitoring module 88: Charged particle beam deflection module 89: Sample stage 90: Sample 91: Primary charged particle beam 92: Charged particle beam probe 93: Secondary Charged particles 94: secondary charged particle detection signal 99: condenser lens module 210: EUV radiation emission plasma/thermoplasma/radiation emission plasma/highly ionized plasma 211: source chamber 212: collector chamber Chamber 220: enclosure structure 221: opening 230: pollutant trap 240: grating filter 251: upstream radiation collector side 252: downstream radiation collector side 253: grazing incidence reflector 254: grazing incidence reflector 255: grazing Incident reflector 400: Method 402: Operate/Generate 403: Operate/Merge 404: Operate/Scatter 406: Operate/Accelerate 408: Operate/Correction 410: Operate/Proceed 500: Schottky emitter/Emitter 502: Electron source Needle 504: suppressor 506: extractor 508: focusing anode 510: energy 512: tip 600: buncher cavity 602: electron source 604: accelerator 606: first cavity/cavity 607: input 608: buncher 610: Second cavity/cavity/second cavity 611: output 612: trap 614: collector 620: feedback path 650: bunched (or pulsed) electron group 700: combined electron detection beam 701: single optical axis 702 : Pulse 704: Pulse 706: Pulse 708: Pulse 710: Pulse 712: Pulse 714: Pulse 716: Pulse 718: Pulse 720: Pulse 722: Pulse 724: Pulse 726: Pulse 750: Deflection Cavity 752: Interval 800: Part 802: Curved path 850: electron 852: relatively short path 854: electron 856: Relatively long path 858: electron 860: other path 868: acceleration cavity 870: longitudinal separation/monochromatic electron beaming 900: condenser lens 901: multi-pole corrector 902: beam tilt coil 904: beam shift coil 906: Adapter lens 908: hexapole element 910: hexapole element 912: transfer lens 914: transfer lens 916: transfer lens 918: transfer lens 920: alignment deflector 922: alignment deflector 924: alignment Deflector 926: Alignment Deflector 928: Alignment Deflector 930: Astigmatism Compensator 932: Astigmatism Compensator 940: Specimen Plane 942: Beam 944: Axial Line 946: Field Line 1050: Sample 1052: Multiple Beams Detection system 1054: source 1056: source multiplier 1058: first projection system 1060: second projection system 1062: detector 1101: longitudinal beam expander 1100: cavity 1102: cavity 1104: beam 1106: drift space 1108: chart 1109 : 1110 width: 1111 chart: 1112 energy spread: chart 1114: 1116 chart: chart e ^-: electronic t: time AD: adjusting member B: light / radiation beam BD: beam delivery system BS: bus C: CC target portion : Cursor control unit CI: communication interface CO: condenser/radiation collector/collector/collector optics CS: computer system DS: display E: energy HC: main computer ID: input device IF: interferometric measurement component /Virtual Source Point/Intermediate Focus IL: Illumination System/Illumination Optics Unit IN: Integrator INT: Internet L: Length LA: Laser LAN: Local Area Network LPA: Lithography Projection Equipment M1: Patterning Device Alignment mark M2: patterned device alignment mark MA: patterned device MM: main memory MT: first object table/patterned device table/object table/support structure NDL: network link O: line/optical axis P1: substrate alignment mark P2: substrate alignment mark PL: lens PM: first locator PRO: processor PS: projection system/item PS1: position sensor PS2: position sensor PW: second locator SD : Storage device SO: Radiation source ST: Substrate table W: Substrate WT: Second object table/Object table X: Direction Y: Direction Z: Direction

The accompanying drawings incorporated in this specification and forming a part of this specification illustrate one or more embodiments and explain these embodiments together with this specification. The embodiments of the present invention will now be described with reference to the accompanying schematic drawings only by means of examples. In these drawings, corresponding component symbols indicate corresponding parts, and in these drawings:

Fig. 1 illustrates a block diagram of various subsystems of a lithographic projection apparatus according to an embodiment.

Fig. 2 schematically depicts an embodiment of an electron beam inspection device according to an embodiment.

Fig. 3 schematically illustrates another embodiment of a detection device according to an embodiment.

FIG. 4 illustrates an example method for improving the detection throughput according to an embodiment.

Figure 5 illustrates an example of a Schottky transmitter according to an embodiment. It should be noted that when a buncher cavity (described herein) is used, a continuous firing Schottky transmitter can be used, for example.

Figure 6 illustrates an example of a buncher cavity according to an embodiment.

FIG. 7 illustrates the combination of pulsed component electron beams into a combined electron detection beam according to an embodiment.

FIG. 8 illustrates a portion of an electron detection beam combined by energy level dispersion and integration according to an embodiment.

Fig. 9 illustrates an example of a multi-pole corrector according to an embodiment.

Figure 10 illustrates detection with a combined electron detection beam according to an embodiment.

Figure 11 illustrates a longitudinal beam expander using a microwave cavity according to an embodiment.

FIG. 12 is a block diagram of an example computer system according to an embodiment.

Fig. 13 is a schematic diagram of a lithography projection device according to an embodiment.

Fig. 14 is a schematic diagram of another lithography projection device according to an embodiment.

Fig. 15 is a detailed view of a lithography projection device according to an embodiment.

FIG. 16 is a detailed view of the source collector module of the lithography projection device according to an embodiment.

400: method

402: Operation/Generation

403: Operation/Merge

404: Operation/Scatter

406: Operation/Acceleration

408: Operation/Calibration

410: Operation/Proceed

Claims (15)

A high-brightness electron source system, which includes: A plurality of emitters, which are configured to generate a corresponding plurality of pulses to form an electron beam; and A first radio frequency (RF) or microwave structure, which is configured to combine the plurality of pulses into electron beams into a combined electron beam aligned along a single optical axis, and the combined electron beams are smaller than the individual pulses Each of the beams has a greater brightness. The system of claim 1, wherein the first RF or microwave structure includes a deflection cavity. Such as the system of claim 1, which further includes: A combination of electro-optical elements configured to reduce the energy spread of the electron beam. Such as the system of claim 3, wherein the combination of the electro-optical element includes a second RF or microwave structure and a third RF or microwave structure, and the second RF or microwave structure and the third RF or microwave structure are caused by a drift therebetween Space separation, where: The second RF or microwave structure is configured to increase the energy spread of an incoming electron pulse by accelerating a front part of the pulse and decelerating a back part of the pulse; The drift space is configured to stretch the pulse in time; The third RF or microwave structure is configured to monochromatize the pulse by decelerating the front portion of the pulse and accelerating the back portion of the pulse; and The signals used to drive the first RF or microwave structure, the second RF or microwave structure, and the third RF or microwave structure are synchronized with each other. Such as the system of claim 4, wherein the signals used to drive the first RF or microwave structure, the second RF or microwave structure, and/or the third RF or microwave structure include multiple high-order harmonics with the same microwave frequency The microwave signal of the wave linearizes a normal sinusoidal electromagnetic field inside a separate RF or microwave structure over time, thus approaching a sawtooth distribution. The system of claim 4, wherein the second RF or microwave structure and the third RF or microwave structure include resonant cavities. Such as the system of claim 3, wherein the combination of the electro-optical elements includes: a curved path configured to disperse the combined electron beam by the energy level, so that the combined electron beam has higher energy electrons Follow a relatively short path, and the electrons with lower energy in the combined electron beam follow a relatively long path; and An accelerator configured to accelerate the combined electron beam so that the electrons with the lower energy in the combined electron beam self-accelerate than the electrons with the higher energy in the combined electron beam More energy is obtained in order to reduce an energy spread between the lower energy electrons and the higher energy electrons. Such as the system of claim 7, wherein the curved path is a track curve. Such as the system of claim 8, wherein the track curve includes a plurality of magnetic deflectors. Such as the system of claim 1, further comprising a multi-pole corrector configured to correct a spherical aberration associated with the combined electron beam. The system of claim 10, wherein the multi-pole corrector includes at least one transfer lens, at least one adapter lens, at least one alignment deflector, a beam tilt coil, a beam shift coil, and at least one astigmatism compensation Device. Such as the system of claim 1, wherein the pulses of electrons in different ones of the plurality of pulses constituting the electron beams are out of phase with each other, so that the combined electron beam is formed by a combination of the out-of-phase pulses of an electron. Such as the system of claim 1, wherein the plurality of transmitters include a plurality of Schottky transmitters or cold field transmitters. A detection system configured to increase detection output, wherein the system includes a high-brightness electron source system as in claim 1. A method for increasing the throughput of detection, the method includes: Generate multiple pulses to form an electron beam; Using a deflection cavity to combine the plurality of pulse component electron beams into a combined electron detection beam, the combined electron detection beam has a greater brightness than each of the individual component pulse electron beams; Dispersing the combined electron detection beam by the energy level, so that the electrons with higher energy in the combined electron detection beam guide the electrons with lower energy in the combined electron detection beam; and Reduce an energy spread between the lower energy electrons and the higher energy electrons; The combined electron inspection beam is configured to inspect a substrate.

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