Multifocal imaging with increased wavelength separation

Abstract

The wavelength selection device comprises a center wavelength selection optic configured to select at least one center wavelength for each pulse in the pulsed light beam as a function of an angle of incidence of the pulsed light beam on the center wavelength selection optic, a tuning mechanism arranged along a path of the pulsed light beam to the center wavelength selection optic, and a diffractive optical element that is passive and transmissive and arranged along the path of the pulsed light beam at a location where the pulsed light beam is fully amplified or at least mostly amplified. The diffractive optical element is configured to generate a plurality of pulsed light sub-beams from the pulsed light beam, each pulsed light sub-beam being associated with a different angle of incidence on the center wavelength selection optic, such that each pulsed light sub-beam is associated with a different wavelength.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to U.S. Application No. 63 / 123,833, filed December 10, 2020, entitled “MULTIFOCAL IMAGING WITH INCREASED WAVELENGTH SEPARATION”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The disclosed subject matter relates to a wavelength selection device for selecting multiple wavelengths of a single pulse beam to form multiple spatial images in a single lithographic exposure process. Background Technology

[0004] Photolithography is a process of patterning semiconductor circuits on a substrate such as a silicon wafer. A photolithography light source provides deep ultraviolet (DUV) light (DUV beam) to expose the photoresist on the wafer. The DUV beam used for photolithography is generated by an excimer light source. Typically, the light source is a laser source, and the output of the laser source is a pulsed laser beam. The DUV beam is passed through a beam transmission unit, a mask, or a photomask, and then projected onto the prepared silicon wafer. In this way, the chip design is patterned onto the photoresist, which is then developed, etched, and cleaned, and then the process is repeated.

[0005] Typically, excimer lasers use a combination of one or more rare gases and reactive gases. The rare gases may include argon, krypton, or xenon, and the reactive gases may include fluorine or chlorine. Excimer lasers can create excimers, pseudo-excimers, under appropriate conditions of electrical simulation (provided energy) and high voltage (of the gas mixture). Excimers exist only in the energized state. The excited-state excimers produce amplified light in the DUV range. Excimer light sources can use a single gas discharge chamber or multiple gas discharge chambers. DUV beams can have wavelengths in the DUV range, including, for example, wavelengths from approximately 100 nanometers (nm) to approximately 400 nm. Summary of the Invention

[0006] In some general aspects, the wavelength selection device is arranged relative to the pulsed light source that generates the pulsed beam. The wavelength selection device includes: a center wavelength selection optics configured to select at least one center wavelength for each pulse in the pulsed beam based on the incident angle of the pulsed beam at the center wavelength selection optics; a tuning mechanism arranged along the path of the pulsed beam to the center wavelength selection optics, the tuning mechanism being configured to optically interact with the pulsed beam and select the incident angle of the pulsed beam at the center wavelength selection optics; and a diffractive optical element, which is passive and transmissive and arranged along the path of the pulsed beam at a location where the pulsed beam is fully amplified or at least substantially amplified. The diffractive optical element is configured to interact with the pulsed beam and generate a plurality of pulsed photon beams from the pulsed beam, each pulsed photon beam being associated with a different incident angle at the center wavelength selection optics, such that each pulsed photon beam is associated with a different wavelength and the spectrum of the pulsed beam includes peaks at each different wavelength.

[0007] The implementation may include one or more of the following features. For example, the diffractive optical element may be a diffraction beam splitter, a diffraction grating, a phase grating, a binary phase grating, or a blazed phase grating.

[0008] The tuning mechanism may include four refractive optical elements. Each refractive optical element may be a right-angle prism. The tuning mechanism may include four right-angle prisms, and the pulse beam is at least substantially amplified in the optical path between the right-angle prism closest to the center wavelength-selective optics and the second right-angle prism closest to the center wavelength-selective optics. The tuning mechanism may include four right-angle prisms arranged along the path of the pulse beam to the diffractive optical elements, and the pulse beam is fully amplified between the four right-angle prisms and the center wavelength-selective optics.

[0009] The wavelength spacing between different wavelengths of multiple pulsed photon beams can be greater than about 10 picometers (pm), about 30 pm, or about 45 pm. The center wavelength of each pulse of the pulsed beam can be about 248 nanometers (nm) or about 193 nm. The wavelength spacing between different wavelengths of multiple pulsed photon beams can depend on the periodic shape of the diffractive optical element.

[0010] The wavelength selection device may further include an actuator configured to adjust the position of the diffractive optical element relative to the path of the pulsed beam, such that the diffractive optical element is positioned along the path of the pulsed beam at certain times and not positioned along the path of the pulsed beam at other times, and the diffractive optical element interacts with the pulsed beam only when it is positioned along the path of the pulsed beam. The actuator may also be configured to adjust the angle of the direction of the diffractive optical element relative to the path of the pulsed beam at the diffractive optical element, such that the different incident angles of each pulsed photon beam generated are adjusted at the central wavelength-selective optics.

[0011] Multiple pulsed photon beams can include three or more pulsed photon beams.

[0012] The tuning mechanism and center wavelength selection optics can be arranged in a Littrow configuration to interact with the pulsed beam. The center wavelength selection optics can be reflective optics.

[0013] Spatial images can be formed for each different wavelength of a pulsed beam.

[0014] The wavelength selection device may also include a control system and one or more actuators associated with the tuning mechanism. The control system may be configured to adjust signals to one or more actuators, thereby adjusting the angle of incidence of the pulsed beam on the center wavelength selection optics.

[0015] Diffractive optical elements can be arranged perpendicular to the propagation direction of the pulsed beam along the path. Diffractive optical elements can be configured to recombine multiple pulsed photon beams from a center wavelength-selective optics to form a pulsed beam.

[0016] In other general aspects, the optical system includes: a light source configured to generate a pulsed beam guided along a path to a photolithography exposure apparatus; the photolithography exposure apparatus configured to interact with the pulsed beam; and a wavelength selection device arranged relative to the light source. The wavelength selection device includes: a center wavelength selection optics configured to select at least one center wavelength for each pulse of the pulsed beam based on the incident angle of the pulsed beam at the center wavelength selection optics; a tuning mechanism arranged along the path from the pulsed beam to the center wavelength selection optics, the tuning mechanism being configured to optically interact with the pulsed beam and select the incident angle of the pulsed beam at the center wavelength selection optics; and a diffractive optical element, which is passive and transmissive and arranged along the path of the pulsed beam at a location where the pulsed beam is fully amplified or at least substantially amplified. The diffractive optical element is configured to interact with the pulsed beam and generate multiple spatially separated but temporally continuous pulsed photon beams from the pulsed beam. Each pulsed photon beam is associated with a different incident angle on a center wavelength-selective optics, such that each pulsed photon beam is associated with a different wavelength, and the spectrum of the pulsed beam includes peaks at each different wavelength.

[0017] The implementation may include one or more of the following features. For example, the diffractive optical element may be a diffraction beam splitter, a diffraction grating, a phase grating, a binary phase grating, or a blazed phase grating.

[0018] The tuning mechanism may include four refractive optical elements. Each refractive optical element may be a right-angle prism.

[0019] The wavelength interval between different wavelengths of multiple pulsed photon beams can be greater than about 10 picometers (pm), about 30 pm, or about 45 pm. The center wavelength of each pulse of the pulsed beam can be about 248 nanometers (nm) or 193 nm.

[0020] The wavelength selection device may include an actuator configured to adjust the position of the diffractive optical element relative to the path of the pulsed beam, such that the diffractive optical element is positioned along the path of the pulsed beam at certain times and not positioned along the path of the pulsed beam at other times, and the diffractive optical element interacts with the pulsed beam only when it is positioned along the path of the pulsed beam. The optical system may also include a control system configured to control the wavelength selection device to adjust the position of the diffractive optical element relative to the path of the pulsed beam.

[0021] A photolithography exposure apparatus may include a mask and a wafer holder, wherein the mask is positioned to interact with a pulsed beam from a light source, and the wafer holder is configured to hold the wafer. Multiple distinct spatial images can be formed on the wafer at the wafer holder, each distinct spatial image based on a different wavelength of a corresponding pulsed photon beam passing through the mask along the propagation direction.

[0022] The optical system may include a control system and one or more actuators associated with a tuning mechanism. The control system may be configured to adjust signals to one or more actuators to adjust the angle of incidence of the pulsed beam on the center wavelength-selective optics.

[0023] In other general aspects, a method for forming multiple spatial images is performed using a single pulsed beam. The method includes: generating a pulsed beam along a path toward a wafer; selecting an angle of incidence of the pulsed beam at the center wavelength-selective optics by optically interacting the pulsed beam with a tuning mechanism arranged along the path of the pulsed beam to a center wavelength-selective optics, to select at least one center wavelength for each pulse in the pulsed beam; generating multiple spatially separated and temporally non-separated pulsed photon beams from the pulsed beam, including dividing the pulsed beam into multiple pulsed photon beams by interacting the pulsed beam with a diffraction pattern arranged along the path of the pulsed beam, each pulsed photon beam being associated with a different angle of incidence at the center wavelength-selective optics, such that each pulsed photon beam is associated with a corresponding wavelength among different wavelengths spaced at least 10 picometers (pm); and forming multiple spatial images on the wafer in the single pulsed beam, wherein each spatial image is formed based on a different wavelength.

[0024] The implementation may include one or more of the following features. For example, a pulsed beam can interact with a diffraction pattern by transmitting the pulsed beam through a diffractive optical element.

[0025] Each different incident angle associated with each pulsed photon beam on the center wavelength selection optics can be determined by the periodic shape of the diffraction pattern.

[0026] The incident angle of the pulsed beam on the center wavelength selective optics can be selected by adjusting one or more angles of the refractive optical element within the tuning mechanism.

[0027] Multiple pulsed photon beams can be generated from a pulsed beam by adjusting the position of the diffraction pattern relative to the path of the pulsed beam. Adjusting the position of the diffraction pattern can be controlled by moving the diffraction optics that include the diffraction pattern.

[0028] By flattening the intensity profile of the pulsed beam at the wafer, multiple spatial images can be formed on the wafer.

[0029] The method may further include recombinating multiple pulsed photon beams departing from the central wavelength-selective optics by interacting the pulsed photon beams with a diffraction pattern arranged along the path of the pulsed photon beam, such that multiple pulsed photon beams are generated when the pulsed photon beams travel along the path to the central wavelength-selective optics and interact with the diffraction pattern, and that the multiple pulsed photon beams are recombinated to form a pulsed photon beam when the pulsed photon beams travel along the path away from the central wavelength-selective optics and interact with the diffraction pattern.

[0030] In other general aspects, the wavelength selection device is associated with a pulsed light source that generates a pulsed beam. The wavelength selection device includes: a center wavelength selection optics configured to select at least one center wavelength for each pulse of the pulsed beam based on the angle of incidence of the pulsed beam at the center wavelength selection optics; a tuning mechanism arranged along a path from the pulsed beam to the center wavelength selection optics, the tuning mechanism being configured to optically interact with the pulsed beam and select the angle of incidence of the pulsed beam at the center wavelength selection optics, the tuning mechanism including four refractive optical elements; and passive, transmissive diffractive optical elements arranged along the path of the pulsed beam at a position between the tuning mechanism and the center wavelength selection optics. The diffractive optical elements are configured to interact with the pulsed beam and generate multiple spatially separated but temporally continuous pulsed photon beams from the pulsed beam. Each pulsed photon beam is associated with a different angle of incidence at the center wavelength selection optics, such that each pulsed photon beam is associated with a different wavelength and the spectrum of the pulsed beam includes peaks at each different wavelength. Attached Figure Description

[0031] Figure 1 This is a block diagram of an optical system, which includes a light source configured to generate a pulsed beam, a photolithography exposure apparatus configured to interact with the pulsed beam, and a wavelength selection device configured to select multiple different center wavelengths in the pulsed beam.

[0032] Figure 2A It includes center wavelength selective optics, tuning mechanisms, and diffractive optical elements. Figure 1 A block diagram illustrating the implementation of the wavelength selection device.

[0033] Figure 2B yes Figure 2A The center wavelength selection optics and the phase grating Figure 2A A block diagram illustrating the implementation of diffractive optical elements.

[0034] Figure 2C yes Figure 1 An example graph of the spectrum of a pulsed beam, the spectrum including peaks at each different center wavelength in the pulsed beam.

[0035] Figure 3A yes Figure 1 A block diagram illustrating the implementation of a photolithography exposure apparatus, which includes components configured to interact with light from... Figure 1 The projection optics system interacts with the pulsed beam of the light source, the mask positioned to interact with the pulsed beam, and the wafer holder configured to hold the wafer.

[0036] Figure 3B It includes slits. Figure 3A Projection optical system Figure 3A A block diagram illustrating the implementation of the mask and the projection lens, including the lens.

[0037] Figure 3C yes Figure 3A A schematic diagram of a wafer, which includes multiple spatial images on different planes along the wafer's z-axis, each spatial image being... Figure 3B The projection optics system is formed during a single exposure.

[0038] Figure 4A yes Figure 2A A block diagram illustrating the implementation of a wavelength selection device, which includes implementations of a tuning mechanism, diffractive optical elements, and a center wavelength selection optical device. The tuning mechanism includes a set of optical components arranged to optically interact with the pulsed beam.

[0039] Figure 4B It shows through Figure 4A A block diagram of beam magnification and beam refraction angle, one of the optical components of a wavelength selection device.

[0040] Figure 5A It is along Figure 4A A block diagram of a top view of the wavelength selection device along the Z-axis, where the Z-direction is perpendicular to the path of the light beam.

[0041] Figure 5B It is along Figure 2A A block diagram of a top view of the Z-axis of another implementation of the wavelength selection device.

[0042] Figure 6A It is along Figure 4A A block diagram of a wavelength selection device, viewed from the Y-axis, comprising an actuator configured to adjust the position of a diffractive optical element relative to the path of a pulse beam, and a diffractive optical element along the path of the pulse beam.

[0043] Figure 6B It is along Figure 4A A block diagram of a wavelength selection device, viewed from the Y-axis. The wavelength selection device includes... Figure 6AThe actuator, and the diffractive optical element outside the pulse beam path.

[0044] Figure 7A It is along Figure 4A A block diagram of a side view of a wavelength selection device along the Z-axis, the wavelength selection device including an actuator and another actuator, the actuator being configured to adjust the angle of the direction of the diffractive optical element relative to the path of the pulse beam at the diffractive optical element, and the other actuator being configured to adjust the angle of one of the optical components in the tuning mechanism, thereby adjusting the incident angle of the pulse beam on the center wavelength selection optics.

[0045] Figure 7B It is along Figure 4A A block diagram of a wavelength selection device, viewed from the Z-axis. The wavelength selection device includes... Figure 7A The actuators are arranged in an adjusted position.

[0046] Figure 8 Is using Figure 1 Single pulse beam formation Figure 3C A flowchart of the process of generating multiple spatial images.

[0047] Figure 9 It includes Figure 2A Wavelength selective device Figure 1 A block diagram illustrating an example of how an optical system is implemented.

[0048] Figure 10A It is along Figure 4A A block diagram of a wavelength selection device, viewed from the top of the Z-axis, showing the implementation of a diffractive optical element as a blazed grating.

[0049] Figure 10B yes Figure 10A The diagram shows a block diagram of a diffractive optical element, which is a blazed grating.

[0050] Figure 10C yes Figure 10A and Figure 10B A side view of a diffractive optical element, with the Z-axis running up and down the page. Detailed Implementation

[0051] refer to Figure 1The optical system 100 includes: a light source 105, which is a pulsed light source configured to generate a light beam 102; a photolithography exposure apparatus 107 configured to interact with the pulsed light beam 102; and a wavelength selection device 110 arranged relative to the light source 105. The light beam 102 is guided along a path 104 to the photolithography exposure apparatus 107. The light beam 102 is a pulsed light beam comprising light pulses that are time-separated from each other. The pulses of the light beam 102 are concentrated around wavelengths in the deep ultraviolet (DUV) range, for example, where the wavelength is 248 nanometers (nm) or 193 nm. The pulsed light beam 102 is used to pattern microelectronic features on a substrate or wafer housed in the photolithography exposure apparatus 107. The size of the microelectronic features patterned on the wafer depends on the wavelength of the pulsed light beam 102, where lower wavelengths result in smaller minimum feature sizes or critical sizes. For example, when the wavelength of the pulsed light beam 102 is 248 nm or 193 nm, the minimum size of the microelectronic feature can be, for example, 50 nm or less.

[0052] A wavelength selection device 110 is positioned at a first end of the light source 105 to interact with the light beam 102 generated by the light source 105. The light beam 102 is a light beam generated at one end of a resonator within the light source 105. For example, the light beam 102 may be a seed beam generated by a master oscillator. The wavelength selection device 110 is configured to fine-tune or adjust the spectral properties of the pulsed light beam 102, including the wavelength of the pulsed light beam 102.

[0053] Specifically, also refer to Figure 2A The wavelength selection device 110 includes a tuning mechanism 112 and a center wavelength selection optics 116. A light beam 102 enters and exits the wavelength selection device 110 through an aperture 211. The center wavelength selection optics 116 is configured to select at least one center wavelength for each pulse of the pulsed light beam 102, based on the angle of incidence of the pulsed light beam 102 interacting with the center wavelength selection optics 116 along a path 104. The center wavelength selection optics 116 may be, for example, a reflective optical element such as a reflective grating. The tuning mechanism 112 is arranged along a path 104 from the pulsed light beam 102 to the center wavelength selection optics 116. The tuning mechanism 112 is configured to optically interact with the pulsed light beam 102 and select the angle of incidence of the central ray of the pulsed light beam 102 on the center wavelength selection optics 116.

[0054] The wavelength selection device 110 is designed to generate a pulsed light beam 102 that can form multiple spatial images on a wafer in the photolithography exposure apparatus 107, wherein each spatial image is located at a different position in space along the z-axis of the wafer, as discussed in more detail below. The position of the spatial image along the z-axis of the wafer depends at least in part on the wavelength of the light beam 102. Therefore, by changing or otherwise controlling the wavelength of the light beam 102, the position of one or more spatial images in the wafer can be controlled. Furthermore, by providing pulses with different primary light wavelengths during a single exposure, multiple spatial images, each located at a different position along the z-axis of the wafer, can be formed during a single exposure without having to move the components of the photolithography exposure apparatus 107 and the wafer relative to each other along the z-axis of the wafer.

[0055] The wavelength of the pulsed beam 102 can be adjusted using a tuning mechanism 112, which may include optical components, such as reflective optics comprising a reflecting prism and a right-angle prism, configured to rotate at a repetition rate to alternate or jitter the wavelength of the pulsed beam 102 using each pulse or an integer number of pulses. For example, a rotating right-angle prism within the tuning mechanism 112 can achieve a maximum wavelength interval of 15 picometers (pm). However, wavelength intervals greater than this maximum wavelength interval may be desired or required depending on the desired or required microelectronic features. Furthermore, it is desirable to generate multiple different wavelengths in the pulsed beam 102 at a given time to simultaneously generate multiple spatial images in the wafer. For this purpose, the wavelength selection device 110 also includes a diffractive optical element 114. The diffractive optical element 114 is configured to interact with the pulsed beam 102 and generate multiple pulsed photon beams 221, 223, 225 from the pulsed beam 102. Each pulsed photon beam 221, 223, 225 is associated with a corresponding different center wavelength w1, w2, w3. Figure 2C Using diffractive optical elements 114 arranged along the path of beam 102 in the wavelength selection device 110, the wavelength interval 220s between the different center wavelengths w1, w2, w3 of the multiple pulsed photon beams 221, 223, 225 can be greater than about 10 picometers (pm). For example, the wavelength interval 220s can be about 30 pm or about 45 pm. The size of the wavelength interval 220s depends on the properties of the diffractive optical elements 114.

[0056] The diffractive optical element 114 is arranged along the path 104 of the pulsed beam 102 at a location where the pulsed beam 102 is fully amplified or at least substantially amplified. Advantages of this arrangement include that the optical peak power of the pulsed beam 102 is less or lower at the location where the beam is fully amplified along path 104 (compared to other locations along path 104). In some implementations, such as... Figure 2AAs shown, the diffractive optical element 114 is arranged along path 104 between the tuning mechanism 112 and the center wavelength selection optical element 116. Figure 2A In one example, the diffractive optical element 114 is arranged perpendicular to the propagation direction of the pulsed beam 102 along the path 104. That is, the surface normal of the diffractive optical element 114 is parallel to the path 104. In other examples, the diffractive optical element 114 may be arranged such that it is not perpendicular to the propagation direction of the pulsed beam 102. Specifically, the diffractive optical element 114 may be arranged, for example, such that its surface normal is within 10 degrees of the propagation direction of the pulsed beam 102.

[0057] The diffractive optical element 114 is passive and therefore operates the beam 102 passively, meaning that no additional energy is required to operate it. The diffractive optical element 114 operates the pulsed beam 102 by splitting it into sub-beams 221, 223, and 225 oriented at different angles. The diffractive optical element 114 also transmits the pulsed beam 102, and the pulsed beam 102 interacts with it by passing through it. Figure 2A In one example, the diffractive optical element 114 generates three pulsed photon beams 221, 223, and 225, each oriented along a different direction and angle. In other examples, the diffractive optical element 114 may generate two or more pulsed photon beams. Furthermore, in... Figure 2A In the example, the diffractive optics 114 is also configured to recombine multiple pulsed photon beams 221, 223, 225 returning from the center wavelength selection optics 116 to form a pulsed beam 102 that is guided along path 104 to the lithography exposure apparatus 107.

[0058] Each pulsed photon beam 221, 223, 225 travels along corresponding paths 222, 224, 226 to the center wavelength selection optics 116. Each pulsed photon beam 221, 223, 225 is associated with different incident angles 222A, 224A, 226A (shown by double-curved arrows) on the center wavelength selection optics 116, such that each pulsed photon beam 221, 223, 225 is associated with a different center wavelength w1, w2, w3. The wavelength interval between the different center wavelengths w1, w2, w3 of the multiple pulsed photon beams 221, 223, 225 is 220s. Figure 2CThe periodic interval 114s between the periodic characteristics of the diffractive optical element 114 depends at least in part on the periodicity of the periodicity of the diffractive optical element 114. Each of the pulsed photon beams 221, 223, 225 maintains its angular offset as it travels along its path. Furthermore, if the pulsed beam 102 is angularly moved or translated, all the sub-beams are thereby uniformly angularly moved or translated without changing the angular interval between each pulsed photon beam 221, 223, 225, nor the wavelength interval between each different center wavelength. However, in this case, the center wavelengths w1, w2, w3 will be offset by an amount determined by how much the pulsed beam 102 is moved or translated.

[0059] exist Figure 2B In the example shown, the diffractive optical element 114 is a phase grating 214, such as a binary phase grating or a blazed phase grating, which has periodic intervals 214s between periodic surface undulations 214g. Light transmitted through the phase grating undergoes a position-dependent phase transition, which can also be generated by the surface undulations, or alternatively by a holographic (interference) pattern. Blazed phase gratings have the advantage of 100% efficiency for the first order (m=1). Furthermore, the blazed phase grating can be configured to have two distinct blaze angles (one blaze angle on each side) and essentially divide the beam 102 into two sub-pulses (each sub-pulse having 50% of the energy); meaning there is no energy contribution to higher-order modes. Additionally, the blazed phase grating 214 can be horizontally slid (e.g., in a blazed phase grating such as...). Figure 5A (As shown in the XY plane), to deflect more of beam 102 to the first order rather than other orders. This ability to control or deflect optical power between spatial images (and thus from one spatial image to another) is useful in optimizing or improving multifocal imaging at a wafer. Phase gratings work by changing the refractive index in a medium, i.e., by modulating the refractive index. Phase gratings are designed to operate at different wavelengths by adjusting the thickness of the medium and modulating the refractive index. An example of a binary phase grating is the binary phase grating from HOLO / OR in Israel, Nyszziona.

[0060] In other implementations, the diffractive optical element 114 may be a diffraction beam splitter or a diffraction grating with grooves to interact with the pulsed beam 102. An example of a one-dimensional diffraction beam splitter is the 1D beam splitter from Israel's HOLO / OR, ness ziona.

[0061] The spectrum 220 of pulse beam 102 Figure 2CThis includes peaks at each different center wavelength w1, w2, w3. Spectrum 220 contains information about how the light energy or power of beam 102 is distributed across different wavelengths (or frequencies). The diffractive optical elements 114 (including a diffraction beam splitter / grating and a phase grating 214) are controlled by periodic variations in physical characteristics. For example, the diffraction beam splitter and grating include grooves, while the phase grating may include periodic surface undulations (such as...). Figure 2B (as shown) or interference patterns. In both cases, the spacing 114s, 214s between these features determines the spacing between these different center wavelengths w1, w2, w3. For example, the difference Δλ(pk2pk) between any two adjacent center wavelengths is proportional to the change (ΔαL) of the incident angle of the sub-beam at the center wavelength selection optics 116 relative to the incident angle of the pulse beam 102 (in the absence of diffraction optics 114). Furthermore, the change (ΔαL) of the incident angle of the sub-beam depends on the feature spacing and the order of the sub-beam. Finally, the difference (Δλ(pk2pk)) is also proportional to dλ / dαL, which is the change of the wavelength of the pulse beam 102 (in the absence of diffraction optics 114) relative to the incident angle of the pulse beam 102 (in the absence of diffraction optics 114) at the center wavelength selection optics 116. Therefore, the design of the diffractive optical element 114 determines the range of variation in the incident angle of each sub-beam on the center wavelength selective optics 116.

[0062] Also refer to Figures 3A-3C In some implementations, the photolithography exposure apparatus 107 includes a projection optics system 327 and a wafer holder 329 configured to hold a wafer 328. The projection optics system 327 includes a mask 336b positioned to interact with a pulsed beam 102 from a light source 105. The photolithography exposure apparatus 107 can be a liquid immersion system or a dry system. The pulsed beam 102 enters the photolithography exposure apparatus 107 through an aperture 311 along a path 104 to interact with the wafer 328 and the mask 336b in the projection optics system 327. For example, microelectronic features are formed on the wafer 328 by exposing a radiation-sensitive photoresist material layer on the wafer 328 with the pulsed beam 102.

[0063] like Figure 3B As shown, the projection optical system 327 includes a slit 336a, a mask 336b, and a projection lens, the projection lens including a lens 336c. A pulsed beam 102 enters the projection optical system 327 and strikes the slit 336a, and at least some of the pulsed beam 102 passes through the slit 336a. Figures 3A-3CIn the example, slit 336a is rectangular and shapes the pulsed beam 102 into an elongated rectangular beam. A pattern is formed on mask 336b, and the pattern determines which portions of the shaped beam are transmitted through and which portions are blocked by mask 336b. The design of the pattern is determined by the specific microelectronic circuitry design to be formed on wafer 328.

[0064] The shaped light beam interacts with mask 336b. A portion of the shaped light beam transmitted through mask 336b passes through projection lens 336c (and can be focused by it) and exposes wafer 328. The portion of the shaped light beam transmitted through mask 336b forms a spatial image in the xy-plane of wafer 328. The spatial image is an intensity pattern formed by the light reaching wafer 328 after interacting with mask 336b. The spatial image is located at wafer 328 and typically extends in the xy-plane.

[0065] The optical system 100, including the wavelength selection device 110, is capable of forming multiple spatial images during a single exposure process, each spatial image located at a different position in space along the z-axis of the wafer 328. In this example, the projection optical system 327 forms three spatial images 331, 333, and 335 at different planes along the z-axis of the wafer 328 during a single exposure process. Each of the spatial images 331, 333, and 335 is formed by light with a center wavelength different from the center wavelengths of the other spatial images 331, 333, and 335. Specifically, each of the spatial images 331, 333, and 335 is formed by a corresponding pulsed photon beam from pulsed photon beams 221, 223, and 225, each pulsed photon beam having a corresponding different center wavelength w1, w2, and w3. In this way, a spatial image 331, 333, 335 is formed for each different center wavelength w1, w2, w3 of the pulse beam 102.

[0066] As described above, the positions of spatial images 331, 333, and 335 along the z-axis depend on the characteristics of the projection optics system 327 (including the projection lens 336c and the mask 336b) and the wavelength of the pulsed beam 102. Typically, light of a single center wavelength passing through the mask 336b is focused onto the focal plane by the projection lens 336c. The focal plane of the projection lens 336c is located between the projection lens 336c and the wafer holder 329, wherein the position of the focal plane along the z-axis of the wafer 328 depends on the properties of the projection optics system 327 and the center wavelength of the pulsed beam 102. Therefore, changing or otherwise controlling the center wavelength of the pulsed beam 102 allows control over the positions of the spatial images 331, 333, and 335. Spatial images 331, 333, and 335 are formed by pulsed beams 102 with different center wavelengths w1, w2, and w3. In this way, spatial images 331, 333, and 335 are located at different positions within the wafer 328. Spatial images 331 and 333 are separated from each other by a distance 330a along the z-axis of wafer 328, and spatial images 333 and 335 are separated from each other by a distance 330b along the z-axis. The distance 330a depends on the difference between the center wavelength w1 of the pulsed beam 102 forming spatial image 331 and the center wavelength w2 of the pulsed beam 102 forming spatial image 333. The distance 330b depends on the difference between the center wavelength w2 of the pulsed beam 102 forming spatial image 333 and the center wavelength w3 of the pulsed beam 102 forming spatial image 335.

[0067] The wafer holder 329 and mask 336b (or other parts of the projection optics system 327) typically move relative to each other in the x, y, and z directions during scanning for routine performance corrections and operations; for example, this movement can be used to achieve basic leveling, compensation for lens distortion, and compensation for stage positioning errors. This relative movement is referred to as incidental operational movement. However, in Figure 3A In this system, the spacing distances 330a and 330b are not formed by the relative movement of the wafer holder 329 and the projection optics system 327. Instead, the spacing distances 330a and 330b are formed by controlling the primary center wavelengths w1, w2, and w3 in the pulses of the pulsed beam 102 passing through the mask 336b during the exposure process. Therefore, unlike some existing systems, the spacing distances 330a and 330b are not created solely by moving the projection optics system 327 and the wafer 328 relative to each other along the z-direction. Furthermore, spatial images 331, 333, and 335 all appear at the wafer 328 during the same exposure process. In other words, the optical system 100 does not need to form the spatial image 331 during the first exposure process, while the spatial images 333 and 335 are formed during subsequent exposure processes.

[0068] Light in the first spatial image 331 interacts with the wafer at plane 331a, light in the second spatial image 333 interacts with the wafer at plane 333a, and light in the third spatial image 335 interacts with the wafer at plane 335a. In some embodiments, the wafer will have been patterned at one or more levels and will include features at different topographic locations on the wafer, i.e., at different planes along the z-axis, such as, but not limited to, features at planes 331a, 331b, and 331c. The aforementioned interactions can form electronic features or other physical properties on the wafer 328, such as openings or holes. Because spatial images 331, 333, and 335 are at different planes along the z-axis, spatial images 331, 333, and 335 can be used to form three-dimensional features on the wafer 328, or they can be used to form features at different topographic levels on the wafer. For example, spatial image 331 can be used to form a peripheral region, spatial image 333 can be used to form a channel with a different position along the z-axis than the peripheral region, and spatial image 335 can be used to form a recess with a different position along the z-axis than the peripheral region and the channel. Thus, multiple different spatial images 331, 333, and 335 are formed on wafer 328, each based on a different center wavelength w1, w2, and w3 of a correlated pulsed photon beam 221, 223, and 225 transmitted through mask 336b along the propagation direction of path 104. In this way, light of different wavelengths can be used to form patterns at different levels of the wafer morphology. Therefore, the techniques described herein can be used to form three-dimensional semiconductor devices, such as three-dimensional NAND flash memory devices.

[0069] refer to Figure 4A The wavelength selection device 110 is implemented in a manner 410 including a tuning mechanism 112, a diffractive optical element 114, and a center wavelength selection optical device 116. Figure 1 The tuning mechanism 412 includes a set of optical features or components 440a-440d, arranged to optically interact with the pulsed beam 102 along path 104. Each of the optical components 440a-440d can be a refractive optical element, such as a right-angle prism. Figure 4AIn one example, the tuning mechanism 412 includes four right-angle prisms 440a-440d. In other examples, the tuning mechanism 412 may include fewer or more than four optical components. Each of the right-angle prisms 440a-440d is arranged along path 104 from the pulsed beam 102 to the diffractive optical element 114. Each of the prisms 440a-440d is a transmission prism, which is used to disperse and redirect the pulsed beam 102 as it passes through the body of the prisms 440a-440d. Each of the prisms 440a-440d may be made of a material that allows wavelengths of the pulsed beam 102 to be transmitted (e.g., calcium fluoride). Figure 4A In the example, the center wavelength selective optics 416 is a reflective grating designed to disperse and reflect the pulsed beam 102; accordingly, the center wavelength selective optics 416 is made of a material suitable for interacting with the pulsed beam 102 with wavelengths in the DUV range.

[0070] like Figure 5A As shown, prisms 440a, 440b, 440c, 440d, the center wavelength selection optics 416, and the diffractive optics 414 are arranged along the XY plane, such that the path of beam 102 generally travels along the XY plane. From Figure 5A As can be seen from the view, prism 440a is positioned furthest from the center wavelength-selective optics 416, while prism 440d is positioned closest to the center wavelength-selective optics 416. The pulsed beam 102 enters the wavelength selection device 410 through aperture 411 and then travels sequentially through prisms 440a, 440b, 440c, and 440d before striking the diffraction surface 416s of the center wavelength-selective optics 416. With each passage of the pulsed beam 102 through successive prisms 440a-440d, the beam 102 is optically magnified and redirected (by refraction at a certain angle) toward the next optical element. Thus, in Figure 4A In the example, the pulsed beam 102 is fully amplified between the four right-angle prisms 440a-440d and the center wavelength selection optics 416. Furthermore, the diffractive optics 414 is positioned in this location. Because the pulsed beam 102 is fully amplified at the diffractive optics 414, the energy or power of the pulsed beam 102 is more uniformly distributed over the surface area of ​​the diffractive optics 414.

[0071] refer to Figure 5BIn one implementation 510 of the wavelength selection device 410, the position where at least most of the pulsed beam 102 is amplified can be in the optical path 104 between the right-angle prism 440d closest to the center wavelength selection optics 416 and the second right-angle prism 440c closest to the center wavelength selection optics 416. Therefore, in these implementations, the diffractive optical element 414 is positioned where at least most of the pulsed beam 102 is amplified, located between prisms 440d and 440c.

[0072] Refer again Figure 4A The diffractive optical element 414 interacts with the pulsed beam 102 to generate multiple pulsed photon beams 221, 223, 225 (e.g., ...). Figure 2A As shown), each pulsed photon beam 221, 223, 225 is guided along corresponding paths 222, 224, 226 to the center wavelength selective optics 416, and each sub-beam 221, 223, 225 is associated with a different incident angle on the center wavelength selective optics 416. Therefore, each of the pulsed photon beams 221, 223, 225 is associated with a different center wavelength w1, w2, w3, and the spectrum 220 of the pulsed beam 102 (…) Figure 2C This includes peak values ​​at each of the different center wavelengths w1, w2, w3. The diffractive optical element 414 does not change the optical magnification of each sub-beam in the generated pulsed photon beams 440a-440d.

[0073] As the pulsed beam 102 leaves the wavelength selection device 410, it is diffracted and reflected back from the central wavelength selection optics 416 before passing through the aperture 411, passing sequentially through diffractive optical elements 414, prisms 440d, 440c, 440b, and 440a. The diffractive optical elements 414 recombine the three pulsed photon beams 221, 223, and 225 traveling from the central wavelength selection optics 416 to reform the pulsed beam 102 before interacting with the tuning mechanism 412. Each time the pulsed beam 102 passes through the successive prisms 440a-440d of the tuning mechanism 412 from the central wavelength selection optics 416, the pulsed beam 102 is optically compressed as it travels toward the aperture 411.

[0074] exist Figure 4AIn the example, each of the prisms 440a-440d is wide enough in the transverse direction of the pulsed beam 102 that the beam 102 is contained within the surface through which it passes. Each prism 440a-440d optically magnifies the beam 102 along the path from the aperture 411 toward the center wavelength selection optics 416, and therefore each prism 440a-440d increases in size continuously from prism 440a to prism 440d. Thus, prism 440d is larger than prism 440c, prism 440c is larger than prism 440b, and prism 440a is the smallest prism.

[0075] refer to Figure 4B The rotation of prism P (which can be any of prisms 440a-440d) in the tuning mechanism 412 changes the incident angle of the pulsed beam 102 striking the incident surface H(P) of the rotating prism P. Furthermore, the two local optical qualities of the beam 102 passing through the rotating prism P, namely, the optical magnification OM(P) and the beam refraction angle (P), are functions of the incident angle of the beam 102 striking the incident surface H(P) of the rotating prism P. The optical magnification OM(P) of the beam 102 through prism P is the ratio of the lateral width Wo(P) of the beam 102 leaving prism P to the lateral width Wi(P) of the beam 102 entering prism P.

[0076] The change in the local optical magnification OM(P) of the pulse beam 102 at one or more prisms P within the tuning mechanism 412 causes an overall change in the optical magnification OM 438 of the pulse beam 102 as it passes through the tuning mechanism 412. The optical magnification OM 438 of the beam 102 as it passes through the tuning mechanism 412 is the ratio of the lateral width Wo of the beam 102 leaving the tuning mechanism 412 to the lateral width Wi of the beam 102 entering the tuning mechanism 412.

[0077] Additionally, the change δ(P) of the local beam refraction angle of one or more prisms P within the tuning mechanism causes a general change in the incident angle of the pulsed beam 102 at the surface 416s of the center wavelength selective optics 416. Therefore, the incident angle of each pulsed photon beam 221, 223, 225 at surface 416s also changes with the rotation of one of these prisms. In this way, the center wavelength of the pulsed beam 102 can also be adjusted by changing the incident angle of the pulsed beam 102 striking the diffraction surface 416s of the center wavelength selective optics 416.

[0078] In some implementations, the center wavelength selective optics 416 is a high blaze angle Echelle grating, and any incident angle of the pulsed beam 102 incident on the center wavelength selective optics 416 that satisfies the grating equations will be reflected (diffracted). Furthermore, if the center wavelength selective optics 416 is used such that the incident angle of the beam 102 onto the center wavelength selective optics 416 is equal to the angle at which the beam 102 exits from the center wavelength selective optics 416, then the center wavelength selective optics 416 and the tuning mechanism 412 (prisms 440a-440d) are arranged in a Littrow configuration to interact with the pulsed beam 102, and the wavelength of the beam 102 reflected from the center wavelength selective optics 416 is the Littrow wavelength. It can be assumed that the vertical divergence of the beam 102 incident on the center wavelength selective optics 416 is close to zero. To reflect the nominal wavelength, the center wavelength selection optics 416 is aligned relative to the beam 102 incident on the center wavelength selection optics 416, such that the nominal wavelength is reflected back through the tuning mechanism 412 (prisms 440a-440d) for amplification in the optical system 100 (when the tuning mechanism 412 is used in the optical system 100). The Littrow wavelength can then be tuned across the entire gain bandwidth of the resonator within the optical system 100 by changing the angle of incidence of the pulsed beam 102 on the center wavelength selection optics 416.

[0079] In some implementations, the wavelength selection device 410 communicates with the control system 450 via a data connection 452. The control system 450 includes electronic devices in any combination of firmware and software. Furthermore, one or more of the center wavelength selection optics 416, the diffractive optics 414, and the prisms 440a-440d of the tuning mechanism 412 can be coupled to a corresponding actuation system, which includes an actuator associated with the tuning mechanism 412 and connected to the control module 450. Figure 4A In one example, control module 450 is connected to actuation systems 414A and 441A, which include actuators physically coupled to diffractive optical element 414 and prism 440d, respectively. In other examples, more than one prism 440a-440d may be coupled to a corresponding actuation system connected to control module 450.

[0080] The control system 450 includes an electronic processor, electronic storage devices, and input / output (I / O) interfaces. The electronic processor is one or more processors adapted to execute computer programs, such as general-purpose or special-purpose microprocessors, and any one or more processors of any type of digital computer. Typically, the processor receives instructions and data from read-only memory or random access memory, or both. The electronic processor can be any type of electronic processor. The electronic storage device can be volatile memory, such as RAM, or non-volatile memory. In some implementations, the electronic storage device may include both non-volatile and volatile portions or components. The electronic storage device stores instructions that may serve as computer programs, which, when executed, cause the processor to communicate with other components in the control system 450 or other components of the wavelength selection device 410. The I / O interface is any type of electronic interface that allows the control system 450 to receive and / or provide data and signals to other components of the wavelength selection device 410, the operator, and / or an automated process running on another electronic device. For example, the I / O interface may include one or more of a touchscreen or a communication interface.

[0081] Each actuator in actuation systems 414A and 441A is a mechanical device for moving or controlling a corresponding optical component. The actuator receives energy from the control system 450 and converts that energy into some kind of motion imparted to the corresponding optical component. For example, the actuator could be either a force-applying device for rotating one or more prisms of a tuning mechanism or a rotary table. The actuator may include, for example, a motor such as a stepper motor, a valve, a pressure control device, a piezoelectric device, a linear motor, a hydraulic actuator, a voice coil, etc.

[0082] refer to Figure 6A and Figure 6B Actuation system 414A ( Figure 4A One or more actuators 614A can be configured to adjust the position of the diffractive optical element 414 relative to the path 104 of the pulsed beam 102. Specifically, the position of the diffractive optical element 414 is adjusted by the actuators 614A along the Z-axis, which is perpendicular to the path of the beam 102 (which is in the XY plane). The actuators 614A can move the diffractive optical element 414 such that the diffractive optical element 414 is positioned along the path 104 of the pulsed beam 102 at certain times. Figure 6A ), and at other times not positioned along the path 104 of the pulse beam 102 ( Figure 6B For example, actuator 614A may include a linear motor, such as a linear stepper motor. Control system 450 may control actuator 614A based on, for example, pre-programmed rules or user input.

[0083] The diffractive optical element 414 interacts with the pulsed beam 102 only when it is positioned along the path 104 of the pulsed beam 102. Figure 6A Therefore, when the diffractive optical element 414 is positioned along the path 104 of the pulsed beam 102, multiple pulsed photon beams 221, 223, and 225 are generated by the diffractive optical element 414, such that the pulsed beam 102 has associated center wavelengths w1, w2, and w3, to form multiple spatial images 331, 333, and 335 at the wafer. When the diffractive optical element 414 is not positioned along the path 104 of the pulsed beam 102 ( Figure 6B The diffractive optical element 414 does not interact with the beam 102, and the pulsed beam 102 contains only the primary center wavelength of the light to form a single spatial image at the wafer 328.

[0084] refer to Figure 7A and Figure 7B Actuation system 414A ( Figure 4A One or more actuators 714A can be configured to adjust the angle of the diffractive optical element 414 about the Z-axis, such that the surface normal of the diffractive optical element 414 rotates relative to the direction of the path 104 of the pulsed beam 102. When the angle of the diffractive optical element 414 relative to the direction of the path 104 is adjusted, the different incident angles of each pulsed photon beam 221, 223, 225 on the center wavelength selective optics 416 are also adjusted.

[0085] In one example, actuator 714A can be configured to correct the angle of diffractive optical element 414 relative to the direction of path 104 of pulsed beam 102 when diffractive optical element 414 becomes severely misaligned (e.g., greater than 10°). For example, vibration or other mechanical disturbances within wavelength selection device 410 may cause diffractive optical element 414 to become misaligned, and actuator 714A can correct these misalignments by adjusting the angle of diffractive optical element 414 relative to the direction of path 104 of pulsed beam 102. For example, if the angle between diffractive optical element 414 and the direction of path 104 of pulsed beam 102 is not equal to 90 degrees or is not within a threshold range of approximately 90 degrees, diffractive optical element 414 can be considered misaligned.

[0086] Furthermore, the actuation system 441A associated with the tuning mechanism 412 ( Figure 4AOne or more actuators 741A can be configured to adjust the signal to one or more actuators 741A, thereby adjusting the incident angle of the pulsed beam 102 on the center wavelength selective optics 416. Specifically, in this example, the prism 440d is physically coupled to actuators 741A that cause the prism 440d to rotate about the z-axis. When the incident angle of the pulsed beam 102 on the center wavelength selective optics 416 is adjusted, the different incident angles of each generated pulsed photon beam 221, 223, 225 on the center wavelength selective optics 416 are also adjusted. Figure 7A and Figure 7B In the example, the control system 450 can control actuators 741A and 714A based on, for example, pre-programmed rules or user input. Each of actuators 714A and 741A can be, for example, a rotary motor, such as a rotary stepper motor.

[0087] refer to Figure 8 Process 860 is performed to form multiple spatial images using a single pulse beam (such as pulse beam 102). Process 860 can be relative to optical system 100 ( Figure 1 The optical system 100 includes a wavelength selection device 110. Figures 2A-2C ), light source 105 and including chip 328 ( Figures 3A-3C The photolithography exposure apparatus 107. Process 860 can also be used relative to the wavelength selection device 410. Figure 4A and Figure 5A ) and wavelength selection device 510 ( Figure 5B The process 860 shall be performed by any of the following. In the following description, the process 860 shall be performed with respect to the optical system 100.

[0088] Process 860 includes generating a pulsed light beam 102 (861) along a path toward the wafer. For example, the pulsed light beam 102 may be generated by a light source 105 and guided along path 104 to the wafer 328 in a photolithography exposure apparatus 107. Figure 1 In the example, the pulsed beam 102 is guided from the light source 105 (after the beam 102 is generated by the light source 105) to interact with the wavelength selection device 110. The pulsed beam 102 is then guided from the wavelength selection device 110 to a photolithography exposure apparatus 107 including a wafer 328, in which a spatial image can be formed.

[0089] The incident angle of the pulsed beam on a center wavelength selection optics (such as 116) is selected, thereby selecting at least one center wavelength (863) for each pulse of the pulsed beam. To select at least one center wavelength for each pulse, the pulsed beam 102 optically interacts with a tuning mechanism arranged along the path from the pulsed beam to the center wavelength selection optics 863. For example, the incident angle of the pulsed beam 102 on the center wavelength selection optics 116 can be selected by causing the pulsed beam 102 to interact with a tuning mechanism 112 of a wavelength selection device 110 arranged along a path 104 from the pulsed beam 102 to the center wavelength selection optics 116. Figure 1 In the optical system 100 (which may be a DUV system), the center wavelength of each pulse of the pulse beam 102 can be selected to be approximately 248 nanometers (nm) or 193 nm.

[0090] In some implementations, the tuning mechanism 112 may be a tuning mechanism 412 including optical elements 440a-440d (which are refractive right-angle prisms). Figure 4A The incident angle of the pulse beam 102 on the center wavelength selective optics 416 can be selected (and changed) by altering or adjusting the arrangement of at least one of the optical elements 440a-440d of the tuning mechanism 412 relative to the path 104 of the pulse beam 102. In other words, the incident angle of the pulse beam 102 on the center wavelength selective optics 416 is selected by adjusting one or more angles of the refractive optical elements 440a-440d within the tuning mechanism 412. In this way, the center wavelength of the pulse beam 102 is adjusted by adjusting the tuning mechanism 112 (or... Figure 4A The tuning mechanism 412 is selected to interact with the pulse beam 102 and the tuning mechanism 112.

[0091] Generating multiple spatially separated but temporally continuous pulsed photon beams from a pulsed beam includes dividing the pulsed beam into multiple pulsed photon beams (865) by interacting the pulsed beam with a diffraction pattern arranged along the path of the pulsed beam. Each pulsed photon beam is associated with a different incident angle on a center wavelength-selective optics such that each pulsed photon beam has a different wavelength, i.e., each pulsed photon beam is associated with a corresponding wavelength among different wavelengths spaced at least 10 picometers (pm) apart (865). For example, multiple spatially separated but temporally continuous pulsed photon beams 221, 223, 225 can be generated by dividing the pulsed beam 102 into multiple pulsed photon beams 221, 223, 225. To divide the pulsed beam 102, the pulsed beam 102 can interact with a diffraction pattern of a diffraction optics 114 arranged along the path 104 of the pulsed beam 102. In other words, by transmitting the pulsed beam 102 through the diffractive optical element 114, the pulsed beam 102 can interact with the diffraction pattern of the diffractive optical element 114.

[0092] Furthermore, by adjusting the position of the diffraction pattern relative to the path 104 of the pulsed beam 102, multiple pulsed photon beams 221, 223, and 225 can be generated from the pulsed beam 102. For example, by controlling actuators 614A and 714A ( Figures 6A-7B The position of the diffraction optical element 114 can be adjusted by translating and / or rotating it, thereby adjusting the position of the diffraction pattern of the diffraction optical element 114 relative to the path 104 of the pulse beam 102. In other words, the position of the diffraction pattern can be adjusted by controlling the movement of the diffraction optical element 114, which includes the diffraction pattern.

[0093] Each generated pulsed photon beam 221, 223, 225 is associated with a different incident angle 222A, 224A, 226A on the center wavelength selective optics 116, such that each pulsed photon beam 221, 223, 225 is associated with a corresponding wavelength among different center wavelengths w1, w2, w3 spaced at least 10 pm apart. Specifically, the wavelength interval between the different center wavelengths w1, w2, w3 of the plurality of pulsed photon beams 221, 223, 225 can be greater than about 10 picometers (pm), or about 30 pm, or about 45 pm. Furthermore, each different incident angle 222A, 224A, 226A associated with each pulsed photon beam 221, 223, 225 on the center wavelength selective optics 116 is determined by the groove spacing 114s of the diffraction pattern (which is included within the diffraction optical element 114).

[0094] exist Figure 1In the example, multiple pulsed photon beams 221, 223, 225 departing from the central wavelength-selective optics 116 are recombined by interacting with a diffraction pattern arranged along the path of the pulsed beam 102. In this way, multiple pulsed photon beams 221, 223, 225 are generated when the pulsed beam 102 travels along path 104 to the central wavelength-selective optics 116 and interacts with the diffraction pattern, and are recombined to form the pulsed beam 102 as the pulsed photon beams 221, 223, 225 travel along path 104 away from the central wavelength-selective optics 116 and interact with the diffraction pattern. Figure 1 In the example, after the pulsed photon beams 221, 223, 225 interact with the center wavelength selective optics 116, the diffractive optics 114 recombines the multiple pulsed photon beams 221, 223, 225 to form a recombinated pulsed beam 102, which is guided along path 104 to the wafer 328. Thus, the recombinated pulsed beam 102, comprising multiple different center wavelengths w1, w2, w3, can then be guided to interact with the photolithography exposure apparatus 107 to form multiple spatial images 331, 333, 335 on the wafer 328.

[0095] Multiple spatial images are formed on the wafer in a single pulsed beam, such that each spatial image is formed based on a different center wavelength (867). For example, multiple spatial images 331, 333, 335 are formed on the wafer 328 in a single pulsed beam 102, such that spatial images 331, 333, 335 are formed at different locations on the z-axis of the wafer, and each spatial image 331, 333, 335 is based on one of a different center wavelength w1, w2, w3. Because the single pulsed beam 102 interacts with the diffraction pattern to select multiple center wavelengths w1, w2, w3 of the recombined pulsed beam 102, each of the multiple spatial images 331, 333, 335 is formed in a single exposure in a single beam 102. The intensity profile of the pulsed beam 102 is planarized at the wafer 328 in the photolithography exposure apparatus 107. Due to the increase in the number of sub-pulses, the intensity is planarized at the wafer 328, and each sub-pulse has the same optical power. The more sub-pulses there are (each with a different center wavelength), the flatter the power distribution will be when focused on the wafer 328.

[0096] Therefore, by causing the pulse beam 102 to interact with the diffraction pattern (or diffraction optical element 114), multiple spatial images 331, 333, and 335, respectively associated with different center wavelengths w1, w2, and w3, are formed on the wafer 328 in a single pulse beam 102 and during a single photolithography exposure.

[0097] refer to Figure 9 The diagram illustrates an example implementation 900 of the optical system 100. The optical system 100 is a lithography system 900, which includes a light source 905 serving as a light source 905. The light source 905 generates a pulsed beam 102 supplied to the lithography exposure apparatus 107. The light source 905 may be, for example, an excimer light source that outputs the pulsed beam 102 (which may be a laser beam). When the pulsed beam 102 enters the lithography exposure apparatus 107, as referenced above… Figures 3A-3C The image, as discussed, is guided through projection optics 327 and projected onto wafer 328. In this manner, one or more microelectronic features are patterned onto a photoresist on wafer 328, which is then developed and cleaned prior to subsequent process steps, and the process is repeated. The photolithography system 900 also includes a control system 450. Figure 4A ),exist Figure 9 In the example, the control system 450 is connected to components of the light source 905 (including the wavelength selection device 410) and the photolithography exposure equipment 107 to control various operations of the control system 900.

[0098] exist Figure 9 In the illustrated implementation, the light source 905 is a two-stage laser system comprising a master oscillator (MO) 970 that supplies a seed beam 902s to a power amplifier (PA) 972. MO 970 and PA 972 can be considered as subsystems of the light source 905 or as part of the light source 905. The power amplifier 972 receives the seed beam 902s from the master oscillator 970 and amplifies it to generate a pulsed beam 102 for use in the photolithography exposure apparatus 107. For example, the master oscillator 970 can emit pulsed seed beams, where the seed pulse energy is approximately 1 millijoules (mJ) per pulse, and these seed pulses can be amplified by the power amplifier 972 to approximately 10 to 15 mJ.

[0099] The master oscillator 970 includes a discharge chamber 971 with two elongated electrodes 974, a gain medium 976 serving as a gas mixture confined within the discharge chamber 971, and a fan for circulating the gas mixture between the electrodes 974. A wavelength selection device 410 is formed on one side of the discharge chamber 971. Figure 4ABetween the optical output coupler 978 on the second side of the discharge chamber 971 and the optical output coupler 978. The wavelength selection device 410 finely tunes or adjusts the spectral properties of the pulse beam 102, including the wavelength and bandwidth of the pulse beam 102, by tuning or adjusting the seed beam 902s.

[0100] The master oscillator 970 may also include a line center analysis module 979 and a beam coupling optics system 980. The line center analysis module 979 receives the output beam from the output coupler 978, and the beam coupling optics system 980 modifies the size or shape of the output beam as needed to form a seed beam 902s. The line center analysis module 979 is a measurement system that can be used to measure or monitor the wavelength and / or bandwidth of the seed beam 902s. The line center analysis module 979 can be placed at other locations within the light source 905, or it can be placed at the output of the light source 905.

[0101] The gas mixture used in discharge chamber 971 can be any gas suitable for generating a beam of light with the wavelength and bandwidth required for the application. For excimer sources, the gas mixture may contain rare gases (scarce gases), such as, for example, argon or krypton; halogens, such as, for example, fluorine or chlorine; and trace amounts of xenon other than helium and / or neon as a buffer gas. Specific examples of gas mixtures include argon fluoride (ArF) emitting light at a wavelength of about 193 nm, krypton fluoride (KrF) emitting light at a wavelength of about 248 nm, or xenon chloride (XeCl) emitting light at a wavelength of about 351 nm. The excimer gain medium (gas mixture) is pumped using short (e.g., nanosecond) current pulses during high-voltage discharge by applying a voltage to the elongated electrode 974.

[0102] The power amplifier 972 includes a beam coupling optics system 982 that receives a seed beam 902s from the master oscillator 970 and guides the beam 902s through the discharge chamber 973 and to a beam steering optics element 981. The beam steering optics element 981 modifies or changes the direction of the seed beam 902s so that it is sent back to the discharge chamber 973 and through the beam coupling optics system 982. The discharge chamber 973 includes an elongated pair of electrodes 975, a gain medium 977 as a gas mixture, and a fan for circulating the gas mixture between the electrodes 975.

[0103] The output pulsed beam 102 is guided through a bandwidth analysis module 983, where various parameters of the beam 102, such as bandwidth or wavelength, can be measured. The output beam 102 can also be guided through a beam preparation system 984. The beam preparation system 984 may include, for example, a pulse broadener, where each pulse of the output beam 102 is broadened temporally, for example, in an optical delay unit, to adjust the performance properties of the beam impacting the photolithography exposure apparatus 107. The beam preparation system 984 may also include other components capable of acting on the beam 102, such as, for example, reflective and / or refractive optical elements (such as lenses and mirrors), filters, and optical apertures (including automatic shutters).

[0104] The lithography system 900 also includes a control system 450. Figure 9 In the illustrated implementation, the control system 450 is connected to various components of the light source 905. For example, the control system 450 can control when the light source 905 emits light pulses or light pulse bursts comprising one or more light pulses by sending one or more signals to the light source 905. The control system 450 is also connected to the photolithography exposure apparatus 107. Therefore, the control system 450 can also receive instructions and / or data from the photolithography exposure apparatus 107. The photolithography exposure apparatus 107 may include a dedicated controller (which can communicate with the control system 450) that can control the exposure of the wafer 328 and can therefore be used to control how electronic features are printed on the wafer 328. In some implementations, the photolithography controller can control the scanning of the wafer 328 by controlling the movement of the slit 336a in the xy plane. Figure 3B The lithography exposure apparatus 107 may also include, for example, temperature control devices (such as air conditioning devices and / or heating devices) and / or power supplies for various electrical components controlled by the lithography controller. In some implementations, the lithography controller is part of a control system 450 and the control system 450 may include more than one sub-control system.

[0105] Furthermore, the control system 450 can control various components of the wavelength selection device 410. For example, the control system 450 can control the position of each prism 440a-440d, the position of the diffractive optical element 414, and the position of the center wavelength selection optical element 416.

[0106] Also refer to Figures 10A-10CThe diagram illustrates an implementation 1014 of the diffractive optical element 114. In this implementation 1014, the diffractive optical element 114 is a blazed grating placed between the prism 440d and the center wavelength selection optics 416. Periodic structures or features are arranged linearly along the Z-axis such that the periodic structures are linearly symmetrical about a centerline 1014c parallel to the Z-axis. As described above, if the blazed grating 1014 is offset along a direction Ds perpendicular to the travel direction of the beam 102 (and also in the XY plane), the amount of light entering one sub-beam relative to other sub-beams and thus striking the selection optics 416 can be adjusted. In this way, the amount of optical power in one spatial image at the wafer can be changed relative to another spatial image. Multifocal imaging at the wafer can be controlled.

[0107] The embodiments may be further described using the following terms:

[0108] 1. A wavelength selection device for a pulsed light source used to generate a pulsed beam, the wavelength selection device comprising:

[0109] A center wavelength selection optics is configured to select at least one center wavelength for each pulse of the pulse beam based on the incident angle of the pulse beam on the center wavelength selection optics.

[0110] A tuning mechanism, arranged along the path of the pulsed beam to the center wavelength selection optics, is configured to optically interact with the pulsed beam and select the angle of incidence of the pulsed beam on the center wavelength selection optics; and

[0111] A diffractive optical element, which is passive and transmissive, is arranged along the path of the pulsed beam at a location where at least most of the pulsed beam is amplified. The diffractive optical element is configured to interact with the pulsed beam and generate multiple pulsed photon beams from the pulsed beam. Each pulsed photon beam is associated with a different incident angle on the center wavelength-selective optics, such that each pulsed photon beam is associated with a different wavelength and the spectrum of the pulsed beam includes peaks at each different wavelength.

[0112] 2. The wavelength selection device according to Clause 1, wherein the diffractive optical element is a diffraction beam splitter, a diffraction grating, a phase grating, a binary phase grating, or a blazed phase grating.

[0113] 3. The wavelength selection device according to Clause 1, wherein the tuning mechanism comprises four refractive optical elements.

[0114] 4. The wavelength selection device according to Clause 3, wherein each refractive optical element is a right-angle prism.

[0115] 5. The wavelength selection device according to Clause 1, wherein the wavelength interval between the different wavelengths of the plurality of pulsed photon beams is greater than about 10 picometers (pm), about 30 pm, or about 45 pm.

[0116] 6. The wavelength selection device according to Clause 1, wherein the center wavelength for each pulse of the pulsed beam is about 248 nanometers (nm) or about 193 nm.

[0117] 7. The wavelength selection device according to Clause 1, wherein the wavelength interval between the different wavelengths of the plurality of pulsed photon beams depends on the periodic shape of the diffractive optical element.

[0118] 8. The wavelength selection device according to Clause 1, wherein the tuning mechanism comprises four right-angle prisms arranged along the path of the pulse beam to the diffractive optical element, and the pulse beam is fully amplified between the four right-angle prisms and the center wavelength selection optics.

[0119] 9. The wavelength selection device according to Clause 1 further includes an actuator configured to adjust the position of the diffractive optical element relative to the path of the pulsed beam such that the diffractive optical element is positioned along the path of the pulsed beam at certain times and not positioned along the path of the pulsed beam at other times, and the diffractive optical element interacts with the pulsed beam only when it is positioned along the path of the pulsed beam.

[0120] 10. The wavelength selection device according to Clause 9, wherein the actuator is further configured to adjust the angle of the diffractive optical element relative to the direction of the path of the pulsed beam at the diffractive optical element, such that the different incident angle of each pulsed photon beam generated is adjusted at the central wavelength selection optics.

[0121] 11. The wavelength selection device according to Clause 1, wherein the plurality of pulsed photon beams comprises three or more pulsed photon beams.

[0122] 12. The wavelength separation device according to Clause 1, wherein the tuning mechanism and the center wavelength selection optics are arranged in a Littrow configuration to interact with the pulsed beam.

[0123] 13. The wavelength separation device according to Clause 1, wherein the center wavelength selection optics is a reflective optical element.

[0124] 14. The wavelength separation device according to Clause 1, wherein the spatial image is formed for each different wavelength of the pulsed beam.

[0125] 15. The wavelength selection device according to Clause 1 further includes a control system and one or more actuators associated with the tuning mechanism, wherein the control system is configured to adjust a signal to the one or more actuators to adjust the incident angle of the pulsed beam on the center wavelength selection optics.

[0126] 16. The wavelength selection device according to Clause 1, wherein the diffractive optical element is arranged perpendicular to the propagation direction of the pulsed beam along the path.

[0127] 17. The wavelength selection device according to Clause 1, wherein the diffractive optics are further configured to recombine the plurality of pulsed photon beams from the central wavelength selection optics to form the pulsed beam.

[0128] 18. The wavelength selection device according to Clause 1, wherein the tuning mechanism comprises four right-angle prisms, and the position where the pulse beam is at least substantially amplified is in the optical path between the right-angle prism closest to the center wavelength selection optics and the second right-angle prism closest to the center wavelength selection optics.

[0129] 19. An optical system comprising:

[0130] The light source is configured to generate a pulsed beam that is guided along a path to the photolithography exposure equipment.

[0131] A photolithography exposure apparatus is configured to interact with the pulsed light beam; and

[0132] The wavelength selection device relative to the light source arrangement includes:

[0133] A center wavelength selection optics is configured to select at least one center wavelength for each pulse of the pulse beam based on the incident angle of the pulse beam on the center wavelength selection optics.

[0134] A tuning mechanism, arranged along the path of the pulsed beam to the center wavelength selection optics, is configured to optically interact with the pulsed beam and select the angle of incidence of the pulsed beam on the center wavelength selection optics; and

[0135] A diffractive optical element, which is passive and transmissive, is arranged along the path of the pulsed beam at a location where the pulsed beam is fully or at least largely amplified. The diffractive optical element is configured to interact with the pulsed beam and generate a plurality of spatially separated and temporally non-separated pulsed photon beams from the pulsed beam. Each pulsed photon beam is associated with a different incident angle on the center wavelength-selective optics, such that each pulsed photon beam is associated with a different wavelength and the spectrum of the pulsed beam includes peaks at each different wavelength.

[0136] 20. The optical system according to Clause 19, wherein the diffractive optical element is a diffraction beam splitter, a diffraction grating, a phase grating, a binary phase grating, or a blazed phase grating.

[0137] 21. The optical system according to Clause 19, wherein the tuning mechanism comprises four refractive optical elements.

[0138] 22. The optical system according to Clause 21, wherein each refractive optical element is a right-angle prism.

[0139] 23. The optical system according to Clause 19, wherein the wavelength interval between the different wavelengths of the plurality of pulsed photon beams is greater than about 10 picometers (pm), about 30 pm, or about 45 pm.

[0140] 24. The optical system according to Clause 19, wherein the center wavelength for each pulse of the pulsed beam is about 248 nanometers (nm) or 193 nm.

[0141] 25. The optical system of claim 19, wherein the wavelength selection device further comprises an actuator configured to adjust the position of the diffractive optical element relative to the path of the pulsed beam such that the diffractive optical element is positioned along the path of the pulsed beam at certain times and not positioned along the path of the pulsed beam at other times, and the diffractive optical element interacts with the pulsed beam only when it is positioned along the path of the pulsed beam.

[0142] 26. The optical system according to Clause 25 further includes a control system configured to control the wavelength selection device to adjust the position of the diffractive optical element relative to the path of the pulsed beam.

[0143] 27. The optical system of claim 19, wherein the photolithography exposure apparatus includes a mask and a wafer holder, the mask being positioned to interact with the pulsed beam from the light source, and the wafer holder being configured to hold the wafer.

[0144] 28. The optical system of claim 27, wherein a plurality of different spatial images are formed on the wafer at the wafer holder, each different spatial image being based on the different wavelength of a correlated pulsed photon beam passing through the mask along the propagation direction.

[0145] 29. The optical system according to Clause 19 further includes a control system and one or more actuators associated with the tuning mechanism, wherein the control system is configured to adjust signals to the one or more actuators to adjust the incident angle of the pulsed beam on the center wavelength selective optics.

[0146] 30. A method for forming multiple spatial images using a single pulsed light beam, the method comprising:

[0147] Generate the pulsed beam that travels along the path toward the wafer;

[0148] By optically interacting the pulsed beam with a tuning mechanism arranged along the path of the pulsed beam to the center wavelength selection optics, the angle of incidence of the pulsed beam on the center wavelength selection optics is selected so as to select at least one center wavelength for each pulse of the pulsed beam.

[0149] Generating a plurality of spatially separated and temporally inseparable pulsed photon beams from the pulsed beam includes dividing the pulsed beam into the plurality of pulsed photon beams by interacting the pulsed beam with a diffraction pattern arranged along the path of the pulsed beam, each pulsed photon beam being associated with a different incident angle on the center wavelength selective optics, such that each pulsed photon beam is associated with a corresponding wavelength among different wavelengths spaced at least 10 picometers (pm); and

[0150] The plurality of spatial images are formed in the single pulse beam on the wafer, wherein each spatial image is formed based on a different wavelength.

[0151] 31. The method according to Clause 30, wherein interacting the pulsed beam with the diffraction pattern comprises transmitting the pulsed beam through a diffraction optical element.

[0152] 32. The method according to clause 30, wherein each different incident angle associated with each pulsed photon beam to the center wavelength-selective optics is determined by the periodic shape of the diffraction pattern.

[0153] 33. The method according to clause 30, wherein selecting the incident angle of the pulse beam on the center wavelength selection optics includes adjusting one or more angles of the refractive optics within the tuning mechanism.

[0154] 34. The method according to clause 30, wherein generating the plurality of pulsed photon beams from the pulsed beam includes adjusting the position of the diffraction pattern relative to the path of the pulsed beam.

[0155] 35. The method according to clause 34, wherein adjusting the position of the diffraction pattern includes control by moving the diffraction optical element comprising the diffraction pattern.

[0156] 36. The method according to Clause 30, wherein forming the plurality of spatial images on the wafer includes flattening the intensity profile of the pulsed beam at the wafer.

[0157] 37. The method according to claim 30 further comprises recombining the plurality of pulsed photon beams departing from the center wavelength selective optics by interacting the pulsed photon beams with the diffraction pattern arranged along the path of the pulsed photon beam, such that when the pulsed photon beam travels along the path to the center wavelength selective optics and interacts with the diffraction pattern, the plurality of pulsed photon beams are generated, and when the pulsed photon beams travel along the path away from the center wavelength selective optics and interact with the diffraction pattern, the plurality of pulsed photon beams are recombinated to form the pulsed photon beam.

[0158] 38. A wavelength selection device for a pulsed light source for generating a pulsed beam, the wavelength selection device comprising:

[0159] A center wavelength selection optics is configured to select at least one center wavelength for each pulse of the pulse beam based on the incident angle of the pulse beam on the center wavelength selection optics.

[0160] A tuning mechanism, arranged along the path of the pulsed beam to the center wavelength-selective optics, is configured to optically interact with the pulsed beam and select the incident angle of the pulsed beam on the center wavelength-selective optics. The tuning mechanism includes four refractive optical elements.

[0161] A passive, transmissive diffractive optical element is arranged along the path of the pulsed beam at a position between the tuning mechanism and the center wavelength selective optics. The diffractive optical element is configured to interact with the pulsed beam and generate multiple spatially separated but temporally continuous pulsed photon beams from the pulsed beam. Each pulsed photon beam is associated with a different incident angle on the center wavelength selective optics, such that each pulsed photon beam is associated with a different wavelength, and the spectrum of the pulsed beam includes peaks at each different wavelength.

[0162] 39. The wavelength selection device according to Clause 38, wherein the diffractive optical element is a diffraction beam splitter, a diffraction grating, a phase grating, a binary phase grating, or a blazed phase grating.

[0163] 40. The wavelength selection device according to Clause 38, wherein the tuning mechanism comprises four refractive optical elements.

[0164] 41. The wavelength selection device according to Clause 38, wherein the wavelength interval between different wavelengths of the plurality of pulsed photon beams is greater than about 10 picometers (pm), about 30 pm, or about 45 pm.

[0165] Other implementations are within the scope of the claims.

Claims

1. A wavelength selection device for a pulsed light source used to generate a pulsed beam, the wavelength selection device comprising: A center wavelength selection optics is configured to select at least one center wavelength for each pulse of the pulse beam based on the incident angle of the pulse beam on the center wavelength selection optics. A tuning mechanism is arranged along the path of the pulsed beam to the center wavelength selection optics, the tuning mechanism being configured to optically interact with the pulsed beam and select the incident angle of the pulsed beam on the center wavelength selection optics; as well as A diffractive optical element, which is passive and transmissive, is arranged along the path of the pulsed beam at a location where at least most of the pulsed beam is amplified. The diffractive optical element is configured to interact with the pulsed beam and generate multiple pulsed photon beams from the pulsed beam. Each pulsed photon beam is associated with a different incident angle on the center wavelength-selective optics, such that each pulsed photon beam is associated with a different wavelength and the spectrum of the pulsed beam includes peaks at each different wavelength.

2. The wavelength selection device according to claim 1, wherein the diffractive optical element is a diffraction grating.

3. The wavelength selection device according to claim 2, wherein the diffraction grating comprises a diffraction beam splitter and a phase grating.

4. The wavelength selection device according to claim 3, wherein the phase grating comprises a binary phase grating or a blazed phase grating.

5. The wavelength selection device according to claim 1, wherein the tuning mechanism comprises four refractive optical elements.

6. The wavelength selection device according to claim 5, wherein each refractive optical element is a right-angle prism.

7. The wavelength selection device according to claim 1, wherein the wavelength interval between the different wavelengths of the plurality of pulsed photon beams is greater than 10 picometers (pm), 30 pm, or 45 pm.

8. The wavelength selection device according to claim 1, wherein the center wavelength for each pulse of the pulsed beam is 248 nm or 193 nm.

9. The wavelength selection device according to claim 1, wherein the wavelength interval between the different wavelengths of the plurality of pulsed photon beams depends on the periodic shape of the diffractive optical element.

10. The wavelength selection device of claim 1, wherein the tuning mechanism comprises four right-angle prisms arranged along the path of the pulse beam to the diffractive optical element, and the pulse beam is fully amplified between the four right-angle prisms and the center wavelength selection optics.

11. The wavelength selection device of claim 1, further comprising an actuator configured to adjust the position of the diffractive optical element relative to the path of the pulsed beam such that the diffractive optical element is positioned along the path of the pulsed beam at certain times and not positioned along the path of the pulsed beam at other times, wherein the diffractive optical element interacts with the pulsed beam only when it is positioned along the path of the pulsed beam.

12. The wavelength selection device of claim 11, wherein the actuator is further configured to adjust the angle of the direction of the diffractive optical element relative to the path of the pulsed beam at the diffractive optical element, such that the different incident angle of each pulsed photon beam generated is adjusted at the central wavelength selection optics.

13. The wavelength selection device according to claim 1, wherein the plurality of pulsed photon beams comprises three or more pulsed photon beams.

14. The wavelength selection device of claim 1, wherein the tuning mechanism and the center wavelength selection optics are arranged to interact with the pulsed beam in a Littrow configuration.

15. The wavelength selection device according to claim 1, wherein the center wavelength selection optics is a reflective optical element.

16. The wavelength selection device of claim 1, wherein the spatial image is formed for each different wavelength of the pulsed beam.

17. The wavelength selection device of claim 1, further comprising a control system and one or more actuators associated with the tuning mechanism, wherein the control system is configured to adjust a signal to the one or more actuators to adjust the incident angle of the pulsed beam on the center wavelength selection optics.

18. The wavelength selection device of claim 1, wherein the diffractive optical element is arranged perpendicular to the propagation direction of the pulsed beam along the path.

19. The wavelength selection device of claim 1, wherein the diffractive optical element is further configured to recombine the plurality of pulsed photon beams from the central wavelength selection optics to form the pulsed beam.

20. The wavelength selection device of claim 1, wherein the tuning mechanism comprises four right-angle prisms, and the position where the pulse beam is at least substantially amplified is in the optical path between the right-angle prism closest to the center wavelength selection optics and the second right-angle prism closest to the center wavelength selection optics.

21. An optical system, comprising: The light source is configured to generate a pulsed beam that is guided along a path to the photolithography exposure equipment. A photolithography exposure apparatus is configured to interact with the pulsed light beam; as well as The wavelength selection device relative to the light source arrangement includes: A center wavelength selection optics is configured to select at least one center wavelength for each pulse of the pulse beam based on the incident angle of the pulse beam on the center wavelength selection optics. A tuning mechanism, arranged along the path of the pulsed beam to the center wavelength selection optics, is configured to optically interact with the pulsed beam and select the angle of incidence of the pulsed beam on the center wavelength selection optics; and A diffractive optical element, which is passive and transmissive, is arranged along the path of the pulsed beam at a location where the pulsed beam is fully or at least largely amplified. The diffractive optical element is configured to interact with the pulsed beam and generate a plurality of spatially separated and temporally non-separated pulsed photon beams from the pulsed beam. Each pulsed photon beam is associated with a different incident angle on the center wavelength-selective optics, such that each pulsed photon beam is associated with a different wavelength and the spectrum of the pulsed beam includes peaks at each different wavelength.

22. The optical system of claim 21, wherein the diffractive optical element is a diffraction grating.

23. The optical system of claim 22, wherein the diffraction grating comprises a diffraction beam splitter and a phase grating.

24. The optical system of claim 23, wherein the phase grating comprises a binary phase grating or a blazed phase grating.

25. The optical system of claim 21, wherein the tuning mechanism comprises four refractive optical elements.

26. The optical system of claim 25, wherein each refractive optical element is a right-angle prism.

27. The optical system of claim 21, wherein the wavelength interval between the different wavelengths of the plurality of pulsed photon beams is greater than 10 picometers per minute (pm), 30 pm, or 45 pm.

28. The optical system of claim 21, wherein the center wavelength for each pulse of the pulsed beam is 248 nm or 193 nm.

29. The optical system of claim 21, wherein the wavelength selection device further comprises an actuator configured to adjust the position of the diffractive optical element relative to the path of the pulsed beam such that the diffractive optical element is positioned along the path of the pulsed beam at certain times and not positioned along the path of the pulsed beam at other times, wherein the diffractive optical element interacts with the pulsed beam only when it is positioned along the path of the pulsed beam.

30. The optical system of claim 29, further comprising a control system configured to control the wavelength selection device to adjust the position of the diffractive optical element relative to the path of the pulsed beam.

31. The optical system of claim 21, wherein the photolithography exposure apparatus includes a mask and a wafer holder, the mask being positioned to interact with the pulsed beam from the light source, and the wafer holder being configured to hold the wafer.

32. The optical system of claim 31, wherein a plurality of different spatial images are formed on the wafer at the wafer holder, each different spatial image being based on the different wavelengths of a correlated pulsed photon beam passing through the mask along the propagation direction.

33. The optical system of claim 21, further comprising a control system and one or more actuators associated with the tuning mechanism, wherein the control system is configured to adjust signals to the one or more actuators to adjust the incident angle of the pulsed beam on the center wavelength selective optics.

34. A method for forming multiple spatial images using a single pulsed light beam, the method comprising: Generate the pulsed beam that travels along the path toward the wafer; By optically interacting the pulsed beam with a tuning mechanism arranged along the path of the pulsed beam to the center wavelength selection optics, the angle of incidence of the pulsed beam on the center wavelength selection optics is selected so as to select at least one center wavelength for each pulse of the pulsed beam. The generation of a plurality of spatially separated and temporally non-separated pulsed photon beams from the pulsed beam includes dividing the pulsed beam into the plurality of pulsed photon beams by interacting the pulsed beam with a diffraction pattern arranged along the path of the pulsed beam, each pulsed photon beam being associated with a different incident angle on the center wavelength selective optics such that each pulsed photon beam is associated with a corresponding wavelength among different wavelengths spaced at least 10 picometers (pm). as well as The plurality of spatial images are formed on the wafer in the single pulse beam, wherein each spatial image is formed based on a different wavelength.

35. The method of claim 34, wherein interacting the pulsed beam with the diffraction pattern comprises transmitting the pulsed beam through a diffraction optical element.

36. The method of claim 34, wherein each different incident angle associated with each pulsed photon beam to the center wavelength-selective optics is determined by the periodic shape of the diffraction pattern.

37. The method of claim 34, wherein selecting the incident angle of the pulsed beam on the center wavelength selection optics comprises adjusting one or more angles of the refractive optics within the tuning mechanism.

38. The method of claim 34, wherein generating the plurality of pulsed photon beams from the pulsed beam includes adjusting the position of the diffraction pattern relative to the path of the pulsed beam.

39. The method of claim 38, wherein adjusting the position of the diffraction pattern comprises controlling it by moving a diffraction optical element comprising the diffraction pattern.

40. The method of claim 34, wherein forming the plurality of spatial images on the wafer includes flattening the intensity profile of the pulsed beam at the wafer.

41. The method of claim 34, further comprising recombining the plurality of pulsed photon beams departing from the center wavelength selective optics by interacting the pulsed photon beams with the diffraction pattern arranged along the path of the pulsed photon beam, such that when the pulsed photon beam travels along the path to the center wavelength selective optics and interacts with the diffraction pattern, the plurality of pulsed photon beams are generated, and when the pulsed photon beams travel along the path away from the center wavelength selective optics and interact with the diffraction pattern, the plurality of pulsed photon beams are recombinated to form the pulsed photon beam.

42. A wavelength selection device for a pulsed light source for generating a pulsed beam, the wavelength selection device comprising: A center wavelength selection optics is configured to select at least one center wavelength for each pulse of the pulse beam based on the incident angle of the pulse beam on the center wavelength selection optics. A tuning mechanism is arranged along the path of the pulsed beam to the center wavelength selection optics. The tuning mechanism is configured to optically interact with the pulsed beam and select the incident angle of the pulsed beam on the center wavelength selection optics. The tuning mechanism includes four refractive optical elements. as well as A passive, transmissive diffractive optical element is arranged along the path of the pulsed beam at a position between the tuning mechanism and the center wavelength selective optics. The diffractive optical element is configured to interact with the pulsed beam and generate multiple spatially separated but temporally continuous pulsed photon beams from the pulsed beam. Each pulsed photon beam is associated with a different incident angle on the center wavelength selective optics, such that each pulsed photon beam is associated with a different wavelength, and the spectrum of the pulsed beam includes peaks at each different wavelength.

43. The wavelength selection device according to claim 42, wherein the diffractive optical element is a diffraction grating.

44. The wavelength selection device according to claim 43, wherein the diffraction grating comprises a diffraction beam splitter and a phase grating.

45. The wavelength selection device according to claim 44, wherein the phase grating comprises a binary phase grating or a blazed phase grating.

46. ​​The wavelength selection device according to claim 42, wherein the tuning mechanism comprises four refractive optical elements.

47. The wavelength selection device according to claim 42, wherein the wavelength interval between the different wavelengths of the plurality of pulsed photon beams is greater than 10 picometers (pm), 30 pm, or 45 pm.

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