Lithography device and method for measuring a radiation beam

Abstract

The present invention provides an apparatus comprising a projection system configured to project a radiation beam having an optical axis. The apparatus comprises a measuring unit positioned to measure the radiation beam projected by the projection system, wherein the measuring unit comprises an opening through which the radiation beam passes when in use, and a sensing surface extending across the optical axis and positioned to measure the radiation beam passing through the opening. A lithography apparatus is configured to move the sensing surface in a plane across the optical axis between a plurality of measuring positions. The radiation beam defines a view in said plane, and the measuring unit is configured such that the sensing surface captures a portion of the view that is smaller than 100% of the view at each measuring position. The present invention includes a corresponding method.

Description

Technology Field

[0001] This application claims priority to EP application 19156895.5 filed on February 13, 2019, the full text of which is incorporated herein by reference.

[0002] The present invention relates to a lithography apparatus and method for measuring a radiation beam. Background Technology

[0003] A lithography device is a machine that applies a desired pattern to a substrate or a part of a substrate. Lithography devices can be used, for example, in the manufacture of flat panel displays, integrated circuits (ICs), and other devices involving microstructures. In conventional devices, a patterning device, which may be referred to as a mask or reticle, can be used to create a circuit pattern corresponding to an individual layer of a flat panel display (or other device). This pattern can be transferred onto all or part of a substrate (e.g., a glass plate) by imaging onto a layer of radiation-sensitive material (e.g., a resist) provided on the substrate.

[0004] Instead of circuit patterns, the patterning device can be used to generate other patterns, such as color filter patterns or a matrix of dots. Instead of a mask, the patterning device may be a patterning array comprising an array of individually controllable elements. Patterns can be changed more quickly and at a lower cost in these systems compared to mask-based systems. Flat panel display substrates are typically rectangular in shape. A lithography device designed to expose this type of substrate can provide an exposure zone that covers the entire width of the rectangular substrate or a portion of its width (e.g., half the width). While the substrate can be scanned beneath the exposure zone, a mask or reticle is scanned synchronously through the beam. In this way, the pattern is transferred to the substrate. If the exposure zone covers the entire width of the substrate, the exposure can be completed in a single scan. If the exposure zone covers, for example, half the width of the substrate, the substrate can be moved laterally after the first scan, and typically additional scans are performed to expose the remainder of the substrate.

[0005] Lithography involves projecting patterns onto a substrate with high accuracy. To ensure that the projection is achieved with high accuracy, various calibration measurements are performed within the device. In some cases, adjustments to the device are made in response to these measurements.

[0006] Known image sensors can be used to measure lens aberrations and intensity distributions in the pupil plane of an illuminator. These sensors may consist of a top plate that transmits light from a projection lens through a grating or pinhole, and a sensor placed in the conjugate pupil plane to record the light spot. The resolution of the light that can be measured depends on the angular resolution of the sensor. The resolution is limited by the number of pixels and the space available to the sensor.

[0007] As advancements are made in the development of lithography tools, requirements for projection optics have increased, necessitating stricter aberration control to enable superior imaging. To provide improved correction techniques, high spatial resolution wavefront measurements may be required to match the resolution needed to provide advanced high-resolution lithography tools. These high spatial resolution wavefront measurements can be particularly advantageous for measuring the illumination pupil during the setup of a lithography device.

[0008] The resolution available for these sensors may be limited for various reasons, but in particular, it may be restricted by the number of pixels and the available space. As higher resolution is desired, smaller pixels are required, or the spot size must be increased by placing the detector further away from the markers used on the sensor. However, both solutions have limitations. If the pixel size is too small, crosstalk may exist between pixels, which degrades the measurement quality from the sensor. Additionally, there are geometric constraints on the space available for these types of sensors, and it may not be possible to increase the distance between the sensor and the markers. Furthermore, the types of sensors used tend to be commercially available (i.e., off-the-shelf detectors). Therefore, there is an advantage in using already available sensor technology or even providing existing solutions in a more favorable way.

[0009] In the present invention, a lithography device is provided comprising: a projection system configured to project a radiation beam having an optical axis; and a measurement unit positioned to measure the radiation beam projected by the projection system, wherein the measurement unit comprises: an opening through which the radiation beam passes when in use; and a sensing surface extending across the optical axis and positioned to measure the radiation beam passing through the opening, wherein the lithography device is configured to move the sensing surface in a plane across the optical axis between a plurality of measurement positions, wherein the radiation beam defines a view in the plane, and the measurement unit is configured such that the sensing surface captures a portion of the view that is less than 100% of the view at each measurement position.

[0010] According to the present invention, a method for measuring a radiation beam in a lithography device is provided, the method comprising: providing a radiation beam; projecting the radiation beam through an opening of a measuring system using a projection system having an optical axis; and measuring the radiation beam that has passed through the opening at a plurality of measuring positions using a sensing surface of the measuring system, wherein the sensing surface extends across the optical axis; the step of measuring the radiation beam comprises moving the sensing surface in a plane across the optical axis between the plurality of measuring positions, wherein the radiation beam defines a view in the plane, and the sensing surface captures a portion of the view that is smaller than 100% of the view at each measuring position.

[0011] With reference to the attached drawings, the structure and operation of various embodiments of the present invention, as well as other embodiments, features, and advantages of the present invention, are described in detail below. Brief explanation of the drawing

[0012] The attached drawings, which are incorporated into and form part of the specification, illustrate one or more embodiments of the present invention and, together with the description, explain the principles of the present invention and serve to enable a person skilled in the art to perform and use the present invention. Figure 1 schematically illustrates a lithography apparatus. Figures 2a and 2b schematically illustrate a known measurement sensor. FIGS. 3A, FIGS. 3B, FIGS. 3C, and FIGS. 3D schematically illustrate an apparatus of one embodiment. FIGS. 4a and FIGS. 4b schematically illustrate an apparatus of one embodiment. FIGS. 5 and FIGS. 6 illustrate a method according to one embodiment. Now, one or more embodiments of the present invention will be described with reference to the accompanying drawings. In the drawings, the same reference numerals may indicate identical or functionally similar elements. Specific details for implementing the invention

[0013] This specification discloses one or more embodiments that embody the features of the present invention. The disclosed embodiments(s) are merely illustrative of the present invention. The scope of the present invention is not limited to the disclosed embodiments(s). The present invention is defined by the claims appended to this specification.

[0014] In this specification, embodiments and references described as “one embodiment,” “one embodiment,” “exemplary embodiment,” etc. indicate that while the described embodiment(s) may include specific features, structures, or characteristics, not all embodiments may necessarily include specific features, structures, or characteristics. Furthermore, these phrases do not necessarily refer to the same embodiment. Also, it is understood that where specific features, structures, or characteristics are described in relation to one embodiment, it is within the knowledge of those skilled in the art that such features, structures, or characteristics result in relation to other embodiments, whether or not explicitly described.

[0015] FIG. 1 schematically illustrates a lithography apparatus. The apparatus comprises an illumination system (illuminator) (IL) configured to condition a radiation beam (B) (e.g., UV radiation or any other suitable radiation); and a patterning device support or support structure (e.g., mask table) (MT) connected to a first positioning device (PM) configured to support a patterning device (e.g., mask) (MA) and to accurately position the patterning device according to predetermined parameters. Additionally, the lithography apparatus comprises a substrate table (e.g., wafer table) (WT) or "substrate support" connected to a second positioning device (PW) configured to hold a substrate (e.g., resist-coated wafer) (W) and to accurately position the substrate according to predetermined parameters. The substrate support may include a substrate table (WT) (otherwise referred to as a chuck) on which a substrate holder is supported. The substrate holder may be configured to support the substrate (W). Additionally, the device includes a projection system (e.g., a refractive projection lens system) (PS) configured to project a pattern applied to a radiation beam (B) by a patterning device (MA) onto a target portion (C) of a substrate (W) (e.g., including one or more dies).

[0016] The lighting system (IL) may include various types of optical components, such as refractive, reflective, magnetic, electromagnetic, electrostatic, or other types of optical components, or any combination thereof, to direct, shape, or control radiation.

[0017] A patterning device support holds the patterning device (MA) in a manner that depends on the orientation of the patterning device (MA), the design of the lithography device, and other conditions, such as whether the patterning device (MA) is maintained in a vacuum environment, for example. The patterning device support may utilize mechanical, vacuum, electrostatic, or other clamping techniques to hold the patterning device. The patterning device support may be, for example, a frame or table that may be fixed or movable as needed. The patterning device support may ensure that the patterning device (MA) is in a desired position, for example, relative to a projection system (PS). Any use of the terms "reticle" or "mask" in this specification may be considered synonymous with the more general term "patterning device."

[0018] The term “patterning device” as used herein should be broadly interpreted to refer to any device that can be used to apply a pattern to the cross-section of a radiation beam to create a pattern on a target portion of a substrate. It should be noted that the pattern applied to the radiation beam (B) may not exactly match the desired pattern within the target portion of the substrate (W), for example, if the pattern includes phase-shifting features or so-called assist features. Generally, the pattern applied to the radiation beam (B) will correspond to a specific functional layer within the device to be created on the target portion, such as an integrated circuit.

[0019] Patterning devices (MAs) can be transmissive or reflective. Examples of patterning devices (MAs) include masks, programmable mirror arrays, and programmable LCD panels. Masks are well known in the field of lithography and include mask types such as binary, alternating phase-shift, and attenuated phase-shift types, as well as various hybrid mask types. One example of a programmable mirror array adopts a matrix configuration of small mirrors, each of which can be individually tilted to reflect an incident radiation beam in different directions. The tilted mirrors impart patterns to the radiation beam reflected by the mirror matrix.

[0020] The term “projection system” as used herein shall be broadly interpreted to encompass any type of projection system, including refractive, reflective, catadioptric, magnetic, electromagnetic, and electrostatic optical systems, or any combination thereof, provided that it is appropriate with respect to the exposure radiation used, or other factors such as the use of immersion liquids or vacuum. Any use of the term “projection lens” in this specification may be considered synonymous with the more general term “projection system.”

[0021] As described in this specification, the device is configured as a transmissive type (e.g., adopting a transmissive mask). Alternatively, the device may be configured as a reflective type (e.g., adopting a programmable mirror array of the type previously mentioned or adopting a reflective mask).

[0022] The lithography apparatus may be configured to have two or more (dual-stage) substrate tables or "substrate supports" (and / or two or more mask tables or "mask supports"). In such a "multi-stage" machine, additional tables or supports may be used in parallel, or a preparation step may be performed on one or more other tables or supports while one or more tables or supports are being used for exposure.

[0023] Additionally, the lithography apparatus may be configured such that at least a portion of the substrate (W) can be covered with a liquid having a relatively high refractive index, such as water, to fill the space between the projection system (PS) and the substrate (W). Additionally, the immersion liquid may be applied to other spaces within the lithography apparatus, for example, between the patterning device (e.g., mask) (MA) and the projection system (PS). The immersion technique may be used to increase the numerical aperture of the projection system. The term "immersion" as used herein means merely that the liquid is placed between the projection system (PS) and the substrate (W) during exposure, rather than implying that a structure such as a substrate must be submerged in the liquid.

[0024] Referring to FIG. 1, the illuminator (IL) receives a radiation beam (B) from a radiation source (SO). For example, if the source is an excimer laser, the source and the lithography device may be separate entities. In this case, the source is not considered to form part of the lithography device, and the radiation beam (B) is passed from the source (SO) to the illuminator (IL) with the help of a beam delivery system (BD), for example, which includes a suitable directional mirror and / or a beam expander. In other cases, for example, if the source is a mercury lamp, the source may be an integral part of the lithography device. The source (SO) and the illuminator (IL), together with the beam delivery system (BD), may be referred to as a radiation system as necessary.

[0025] The illuminator (IL) may include a regulator (AD) configured to adjust, for example, the angular intensity distribution of the radiation beam. Generally, at least the outer radius and / or inner radius of the intensity distribution within the pupil plane of the illuminator (typically referred to as outer-σ and inner-σ, respectively) may be adjusted. Additionally, the illuminator (IL) may include various other components, such as an integrator (IN) and a condenser (CO). The illuminator may be used to condition the radiation beam (B) to have a desired uniformity and intensity distribution across the cross-section of the radiation beam.

[0026] A radiation beam (B) is incident on a patterning device (e.g., mask) (MA) held on a mask support structure (e.g., mask table) (MT) and is patterned by the patterning device (MA). Once it has crossed the patterning device (e.g., mask) (MA), the radiation beam (B) passes through a projection system (PS), which focuses the beam onto a target portion (C) of a substrate (W). With the help of a second positioning device (PW) and a position sensor (IF) (e.g., an interferometer device, a linear encoder, or a capacitive sensor), the substrate table (WT) can be moved precisely to position different target portions (C), for example, within the path of the radiation beam (B). Similarly, a first positioning device (PM) and another position sensor (not clearly shown in FIG. 1) can be used to accurately position a patterning device (e.g., mask) (MA) in the path of a radiation beam (B), for example, after mechanical retrieval from a mask library or during scanning. Generally, movement of a patterning device support (e.g., mask table) (MT) can be realized with the help of a long-stroke module (rough positioning) and a short-stroke module (fine positioning), which form part of the first positioning device (PM). Similarly, movement of a substrate table (WT) or "substrate support" can be realized using a long-stroke module and a short-stroke module, which form part of the second positioner (PW). (In contrast to a scanner) in the case of a stepper, the patterning device support (e.g., mask table) (MT) may be connected to or fixed only to a single-stroke actuator. The patterning device (e.g., mask) (MA) and the substrate (W) may be aligned using patterning device alignment marks (M1, M2) and substrate alignment marks (P1, P2).Although the illustrated substrate alignment marks occupy dedicated target portions, they may also be located within the spaces between the target portions [these are known as scribe-lane alignment marks]. Similarly, in situations where more than one die is provided on a patterning device (e.g., mask) (MA), patterning device alignment marks may be located between the dies.

[0027] The described device may be used in at least one of the following modes:

[0028] 1. In step mode, the patterning device support (e.g., mask table) (MT) or "mask support" and the substrate table (WT) or "substrate support" are basically kept in a stationary state, while the entire pattern applied by the radiation beam (B) is projected onto the target portion (C) at once [i.e., single static exposure]. Afterward, the substrate table (WT) or "substrate support" is shifted in the X and / or Y directions so that different target portions (C) can be exposed. In step mode, the maximum size of the exposure field limits the size of the target portion (C) being imaged during a single static exposure.

[0029] 2. In scan mode, the patterning device support (e.g., mask table) (MT) or "mask support" and the substrate table (WT) or "substrate support" are scanned synchronously while the pattern imparted by the radiation beam (B) is projected onto the target portion (C) [i.e., single dynamic exposure]. The speed and orientation of the substrate table (WT) or "substrate support" relative to the patterning device support (e.g., mask table) (MT) or "mask support" may be determined by the magnification (reduction) and image inversion characteristics of the projection system (PS). In scan mode, the maximum size of the exposure field limits the width of the target portion (in the non-scanning direction) during single dynamic exposure, while the length of the scanning motion determines the height of the target portion (in the scanning direction).

[0030] 3. In another mode, the patterning device support (e.g., mask table) (MT) or “mask support” is maintained in a basically stationary state by holding the programmable patterning device, and the substrate table (WT) or “substrate support” is moved or scanned while the pattern imparted by the radiation beam is projected onto the target portion (C). In this mode, a pulsed radiation source is generally employed, and the programmable patterning device is updated as needed after each movement of the substrate table (WT) or “substrate support,” or between continuous radiation pulses during scanning. This mode of operation can be easily applied to maskless lithography using a programmable patterning device such as a programmable mirror array of the type mentioned above.

[0031] In addition, combinations and / or variations of the aforementioned usage modes, or completely different usage modes may be adopted.

[0032] As previously described, measurements may be performed to reduce errors in the radiation beam (B) incident on the substrate (W). Known sensors may be used to perform calibration measurements of the radiation beam (B) projected by the projection system (PS). One such calibration measurement performed in a lithography device is the measurement of aberrations present in the radiation beam projected by the projection system (PS). However, there are limitations to the resolution of known sensors for performing these measurements. As previously described, the resolution may be limited by the number of pixels within the sensor and / or the space available to the sensor. For example, the number of pixels may be limited by the sensor technology and / or the cost of the sensor to be used. The available space of the sensor may be limited depending on the location of the sensor.

[0033] Therefore, it is advantageous to provide an apparatus and method for measuring a radiation beam in a lithography apparatus. Ideally, the apparatus and method of the present invention can be used to provide improved measurements in a lithography apparatus.

[0034] The present invention relates to a lithography apparatus, for example, as described above. The lithography apparatus may include some or all of the aforementioned features. The lithography apparatus may not be limited to including all of the features described above.

[0035] A lithography device includes a projection system configured to project a radiation beam having an optical axis. The projection system of the lithography device may be configured as described in the preceding examples or otherwise configured. Generally, the projection system is any system used to project a radiation beam. The radiation beam may be the same as the radiation beam (B) described above.

[0036] An optical axis can be understood as having the general meaning of a line in an optical system, that is, a projection system, where a certain degree of rotational symmetry exists. An optical axis does not necessarily pass through the central axis of the projection system. The radiation beam projected by the projection system may lie along the optical axis. Therefore, the optical axis may be the axis along which the radiation beam is projected by the projection system.

[0037] The lithography device further includes a measuring unit positioned to measure a radiation beam projected through a projection system. The measuring unit includes an opening through which the radiation beam passes during use. The measuring unit further includes a sensing surface extending across an optical axis. The sensing surface is positioned to measure the radiation beam passing through the opening. The sensing surface may be positioned relative to the optical axis such that the radiation beam passing through the opening is incident on the sensing surface. Thus, the sensing surface is located downstream of the opening so that the radiation beam is incident on the sensing surface after passing through the opening.

[0038] A sensing surface that crosses the optical axis means that the sensing surface extends across the optical axis. Therefore, the sensing surface is not parallel to the optical axis. Additionally, the sensing surface is positioned so that the optical axis passes through the sensing surface. For example, the sensing surface may be orthogonal to the optical axis. However, this is not mandatory, and the sensing surface may be tilted in some way with respect to the optical axis, that is, at an angle between the sensing surface and the optical axis that is greater than 0° and less than 90°.

[0039] The lithography device is configured to move a sensing surface in a plane that crosses the optical axis between multiple measurement positions. Thus, the plane in which the sensing surface moves is not parallel to the optical axis, that is, it is not only in a direction parallel to the optical axis. In other words, at least the movement component of the sensing surface between multiple measurements is not parallel to the optical axis, that is, there is a movement component perpendicular to the optical axis and optionally a movement component parallel to the optical axis. Additionally, the plane is positioned so that the optical axis passes through the plane. It may be desirable for the plane in which the sensing surface moves to be orthogonal to the optical axis. This can allow the measurements to be performed in a manner that is easier to process as the measurements are performed at a set distance from the aperture. However, this is not mandatory, and the plane may be tilted in some way with respect to the optical axis, that is, at an angle between the sensing surface and the optical axis that is greater than 0° and less than 90°.

[0040] As described in more detail below, the sensing surface can be moved to different measurement positions to measure the radiation beam incident on the sensing surface at those positions. The sensing surface can be moved in various ways. The sensing surface can be moved relative to the radiation beam, that is, along the optical axis as previously described.

[0041] The radiation beam defines a view in the aforementioned plane (where the sensing surface moves). This means that a cross-section through the radiation beam in the plane provides the view. The radiation beam can be measured by the sensing surface in the plane. As is understood, the intensity of the radiation beam can vary across the view.

[0042] The measurement unit is configured so that the sensing surface captures a portion of the view that is smaller than 100% of the view at each measurement location. In other words, the sensing surface is smaller than 100% of the view in the plane in which the sensing surface is moved. Therefore, if a cross-section of the radiation beam is taken in the plane in which the sensing surface is moved, the cross-sectional area of ​​the radiation beam (which is 100% of the view) will be larger than the cross-sectional area of ​​the sensing surface. This means that only a portion, rather than the whole, of the radiation beam is incident on the sensing surface at any given moment, that is, when the sensing surface is at a single measurement location. As previously described, the sensing surface is moved to different measurement locations in the plane so that multiple measurements of the radiation beam can be performed across the plane. 100% of the view may otherwise be referred to as the entire view.

[0043] Providing a measurement unit configured in this manner is advantageous because it allows for higher resolution measurements to be performed than using known sensors. More specifically, since the sensing surface is used to measure a smaller portion of the radiation beam than known sensors, this means that measurements of the radiation beam can be performed with higher resolution using the same sensing surface (i.e., the same number of pixels and sensing surface size). Alternatively, if this improvement in resolution does not provide a significant advantage to the user, the user can replace current systems with the present invention, and measurements with the same resolution can be performed using a smaller volume for the measurement unit. Alternatively, if this improvement in resolution does not provide a significant advantage to the user, the user can replace current systems with the present invention, and measurements with the same resolution can be performed using larger pixels, for example, with a less expensive sensing surface, which will provide more accurate measurements due to reduced pixel crosstalk and lower noise.

[0044] The sensing surface may be part of the sensor. The sensing surface may be substantially flat or curved. The sensing surface may be flat, but may be provided obliquely with respect to the optical axis (not parallel or orthogonal), that is, the sensing surface may be inclined. The sensing surface may be any suitable shape. Below, drawings are described in which the sensing surface is shown as being square or rectangular. However, the sensing surface is not limited to a specific shape. The sensing surface is part of the sensor capable of measuring a radiation beam, that is, the part of the sensor into which the radiation beam is incident for measuring the radiation beam. Various different types of sensing surfaces / sensors may be used. For example, the sensing surface may be part of a charge-coupled device (CCD) and / or a complementary metal-oxide semiconductor (CMOS) sensor. The sensor may otherwise be referred to as a detector or a sensing unit. Any sensor or detector configured to capture light intensity may be used. The sensing surface may be provided by multiple cells and / or individual sensing devices. For example, the sensing surface can be formed by a strip of photosensitive devices.

[0045] As previously mentioned, the lithography device is configured to move the sensing surface. Accordingly, the lithography device can be positioned to change the location of the sensing surface, specifically to move the sensing surface between multiple measurement positions. Thus, the sensing surface can obtain measurements of multiple portions of the radiation beam in the plane in which the sensing surface is moved. This is advantageous because it means that a larger portion of the radiation beam in the plane can be measured at higher resolution.

[0046] The position of the sensing surface can be moved relative to the radiation beam. If the lithography device is configured such that the sensing surface measures the radiation beam at multiple measurement positions, it can be configured to maintain the position of the radiation beam projected by the projection system at a substantially constant position. Thus, the position of the radiation beam can be maintained substantially constant, while the position of the sensing surface can be changed. The movement of the sensing surface will be described in more detail below. In this way, the sensing surface can be used to measure different portions of the radiation beam in the plane in which the sensing surface is moved. The portion of the radiation beam being measured can be determined based on the position of the sensing surface where the measurement is taken.

[0047] The lithography device may include a support table as described above. The support table may be configured to support a substrate (W), and, for example, the support table may be a substrate table (WT) as described above. A measurement unit may be provided on the support table. Thus, the measurement unit may be supported on the surface of the support table. The measurement unit may be formed as part of the support table.

[0048] A lithography device may be configured to move a sensing surface by moving a support table. A lithography device may be configured to move the sensing surface in a number of different ways. When the sensing surface (and more generally, a measuring unit) is supported by a support table, the movement of the support table may move the position of the sensing surface (and the measuring unit). For example, a lithography device may include a positioner and a sensor configured to accurately move the support table, such as a second positioner (PW) and a position sensor (IF). The positioner may optionally include a long-stroke module and a short-stroke module to accurately position the support table and the corresponding sensing surface as described above. If the sensing surface is provided on or as part of any other support, similar components may be used to accurately position the support and / or the sensing surface.

[0049] Additionally or alternatively, the position of the sensing surface can be controlled independently of the support on which the sensing surface is placed. Thus, the lithography device can be configured to move the sensing surface relative to the support. For example, as further described below, the lithography device may include an actuator configured to move the measuring unit. Additionally or alternatively, the sensing surface can be moved separately from other components of the measuring unit. For example, at least one actuator (not shown) may be provided to move the sensing surface relative to other components of the measuring unit and / or the radiation beam.

[0050] Theoretically, the position of the sensing surface can be kept constant, while the radiation beam can be moved. Accordingly, since different parts of the view of the radiation beam in a plane can be measured, this will provide the same advantage.

[0051] Preferably, at least a portion of the view captured by the sensing surface at one measurement location does not overlap with a portion of the view captured by the sensing surface at any other measurement location. In other words, the sensing surface can be used to measure at least one distinct unmeasured region of the radiation beam in the view at each measurement location. Thus, at each measurement location, the sensing surface can measure a portion of the radiation beam that is not measured when the sensing surface is at any other measurement location. This is advantageous because it means that a larger portion of the entire view can be measured by the sensing surface at different measurement locations, as each measurement location captures at least a new portion of the view that is not measured at other measurement locations. Therefore, reducing overlap increases the angular resolution. Additionally, the angular resolution may be increased by increasing the number of apertures.

[0052] Preferably, there may be some overlap between the portions of the view captured by the sensing surface at different measurement positions. More preferably, there is a selected amount of overlap of the views measured at adjacent measurement positions. Having a certain amount of overlap of the views measured when the sensing surface is at different measurement positions can be advantageous because it helps increase accuracy by allowing measurements performed at different measurement positions to be compared. Overlapping measurements can be used to correct for variations over time and to increase measurement accuracy. The amount of overlap can be controlled by controlling the movement of the sensing surface and / or by selecting the positions of the openings relative to each other (if multiple openings are provided) and / or by selecting the position of the sensing surface relative to the opening(s).

[0053] Ideally, the sensing surface is moved to different measurement positions such that, as previously described, there exists at least a portion of the view being measured that does not overlap, as well as a selected amount of overlap to ensure that accurate measurements are performed. In other words, the sensing surface is moved to different measurement positions such that at most a portion of the view being measured—for example, up to 10% or 50% of this view—overlaps with a portion or part of the view captured by the sensing surface at any other measurement positions.

[0054] A lithography device can be configured to combine portions of a view captured at multiple measurement positions. In this way, the lithography device can be used to combine measurements of various different portions of a radiation beam. Ideally, the lithography device can be configured to combine portions to provide a measurement of 100% of the view in the plane. This can be advantageous in that measurements can be taken across the entire radiation beam in the plane where the sensing surface moves. Since the sensing surface performs measurements that are not 100% of the view, this means that the measurements of the radiation beam are smaller than the view, which implies that the resolution of the measurements is higher than when using a similar sensing surface to capture the entire view at a single measurement position. This means that more accurate measurements can be provided across the entire radiation beam. In this way, improved measurements can be achieved while still using the same sensing surface that may have been used in known sensing devices.

[0055] The lithography device may include a processor configured to combine portions of a view captured at multiple measurement locations. The processor may receive data from a sensing surface representing view captures by the sensing surface. Data may be transmitted from the sensing surface to the processor via a network (i.e., wirelessly) or using wires. The processor may be any suitable computing device / electronic circuit that can be used to receive and combine data.

[0056] The distance between the opening and the sensing surface is such that 100% of the area of ​​the view in the plane is larger than the sensing surface, i.e., the entire area of ​​the sensing surface. In other words, the sensing surface may be positioned relative to the opening such that the view of the radiation beam in the plane is larger than the sensing surface. For a given size of the opening and the sensing surface, there may exist a preset minimum distance. Thus, the distance may vary depending on at least these factors.

[0057] The sensing surface, that is, the entire area of ​​the sensing surface, may be about 70% or less of the 100% area of ​​the view. Thus, at any of the measurement locations, the sensing surface may be used to measure about 70% or less of the radiation beam in the plane in which the sensing surface moves, that is, about 70% or less of the entire view. Alternatively, the area of ​​the sensing surface may be smaller. For example, the sensing surface may be about 60% or less of the 100% area of ​​the view, or about 50% or less of the 100% area of ​​the view, or about 30% or less of the 100% area of ​​the view.

[0058] The opening may be provided in various different configurations. As described later, the opening may be a hole simply passing through the plate, or a slit or a set of lines. The opening may be made of any suitable shape and size. If the opening is a slit, this means that the sensor surface moves along only one direction, which can induce a kind of continuous or discontinuous scanner operation. The opening may optionally be a 1D or 2D pattern and preferably may include a grid. The grid may be any suitable shape. For example, the grid may be a 1D pattern or a 2D pattern, such as a checkerboard pattern with a preset pitch.

[0059] The measuring unit may include a plate in which the plate forms an opening. The plate may have any appropriate number of openings. For example, the plate may include a single opening or multiple openings as further described. The plate may provide the opening by having a through hole through which radiation can pass. The plate may include some grid shape in the opening as previously mentioned. The plate may be any element having any appropriate shape and thickness to form an opening through which a radiation beam can pass to a sensing surface.

[0060] For comparison purposes only as a side step, a sensor that may have been previously used in the prior art is illustrated in FIGS. 2a and 2b. FIG. 2a shows a schematic drawing of the XY plane, which may be considered a top view. FIG. 2b shows a schematic drawing of the ZX plane, which may be considered a side view. As shown, the sensor comprises a plate (PL) forming an opening (O) and a sensing surface (S). A beam (B) passes through the opening (O) and forms a cone of radiation at the sensor. Here, a cone of radiation is generated and illustrated, but this is merely for illustrative purposes, and a beam of any shape may be measured. The sensing surface (S) is used to measure the radiation beam. The view of the radiation beam (B) in the plane of the sensing surface (S) is smaller than that of the sensing surface. Therefore, at a single measurement position as shown in FIGS. 2a and 2b, the sensing surface (S) captures the entire view (V), i.e., 100% of the view. So far, we have been side steps, and now we return to the present invention.

[0061] In one embodiment, the measuring unit includes a plurality of openings through which a radiation beam passes when in use, and one of the openings is used for each measuring position. This means that when a sensing surface is at each of the measuring positions, the radiation beam passes through one of the plurality of openings and is incident on the sensing surface. Preferably, the plurality of openings are in a fixed position relative to the sensing surface. Therefore, the sensing surface and the plurality of openings do not move relative to each other. This embodiment is illustrated in FIGS. 3a, 3b, 3c, and 3d. These figures illustrate a measuring unit (M) configured such that the sensing surface (S) captures a portion of the view that is smaller than 100% of the view at each measuring position. The full view (V) of the radiation beam (B) in the plane in which the sensing surface (S) moves appears to be larger than the area of ​​the sensing surface (S).

[0062] As previously described, the lithography device may include a projection system (PS) (as shown in FIG. 3c and 3d). A radiation beam (B) is projected by the projection system (PS) and incident on a sensing surface (S). The sensing surface (S) is configured to measure a portion of the view smaller than 100% of the view at each measurement location. FIG. 3a and 3b illustrate a measurement unit (M) and, in particular, a sensing surface (S) that are moved between a first measurement location (1), a second measurement location (2), a third measurement location (3), and a fourth measurement location (4). FIG. 3c and 3d show the first measurement location (1) and the second measurement location (2) in more detail.

[0063] As shown, the measurement system (M) may include a plurality of openings (O1, O2, O3, O4), through which a radiation beam passes when in use. One of the plurality of openings may be used for each measurement location. The measurement system (M) may include a plate (PL) as previously described, and the plate (PL) includes a plurality of openings. As shown in these drawings, four openings (O1, O2, O3, O4) are shown at a distance Z1 from the sensing surface (S). As shown, since the four openings (O1, O2, O3, O4) are in a plane parallel to the sensing surface (S), the distance (Z1) from the sensing surface (S) to each of the plurality of openings (O1, O2, O3, O4) is the same. Any number of suitable openings may exist. The number of openings may vary, and the distance from each opening to the sensing surface (S) may differ from that of other openings.

[0064] Multiple openings (O1, O2, O3, O4) may be in fixed positions relative to the sensing surface (S), and, for example, a plate (PL) containing the openings may be connected to the sensing surface (S) in some way. A measuring unit (M) may include a housing (H) that supports the sensing surface (S) and the plate (PL) containing the openings (O1, O2, O3, O4). The sensing surface (S) and the plate (PL) may be attached to the housing (H) so that these components have fixed positions relative to each other. In this embodiment, the openings (O1, O2, O3, O4) are moved relative to the radiation beam (B) in the same manner as the sensing surface (S) is moved relative to the radiation beam (B). Although the housing (H) is shown in these drawings, the sensing surface (S) and the openings (O1, O2, O3, O4) may be provided as part of a support such as a substrate table (WT) capable of holding the openings (O1, O2, O3, O4) and the sensing surface (S) in a fixed position relative to each other.

[0065] One of the multiple openings may be used for each measurement location. Thus, when a measurement is being taken at one of the measurement locations, the radiation beam (B) may pass through one of the multiple openings (O1, O2, O3, O4) and be incident on the sensing surface (S). When the sensing surface (S) and the openings (O) are moved relative to the radiation beam (B), the radiation beam (B) may pass through a different one of the openings (O) and be incident on the sensing surface (S) for measurements at different measurement locations. Thus, there may be one opening corresponding to each measurement location.

[0066] As previously described, the lithography device is configured to move the sensing surface (S) in a plane that crosses the optical axis (OA) of the projection system (PS). This is illustrated by the change in position of the measuring unit (M) at the measurement positions (1 to 4) shown in FIGS. 3a and 3b. In the drawings, for example, the sensing surface (S) is moved in an XY plane orthogonal to the optical axis (OA). As previously indicated, this is not mandatory.

[0067] The position of the sensing surface (S) [and, in this example, the entire measuring unit (M)] can be moved relative to the projected beam (B) so that different parts of the entire view (V) of the radiation beam (B) in the plane in which the sensing surface (S) is moved can be measured. In this example, as shown in FIG. 3a, there is little or no overlap between the measurements performed by the sensing surface (S) at the first measuring position (1), the second measuring position (2), the third measuring position (3), and the additional measuring position (4). As previously described, having some overlap may be advantageous.

[0068] In this embodiment, the lithography device is configured to move the sensing surface (S) in the plane with respect to a radiation beam (B) projected by a projection system (PS) to obtain measurements at a plurality of measurement locations. The lithography device may be configured to maintain the position of the radiation beam (B) projected by the projection system (PS) at a substantially constant position for measurements at a plurality of measurement locations.

[0069] In FIG. 3a and FIG. 3b, four measurement positions are shown from left to right. At the first measurement position (1) (the position on the left), the sensing surface (S) captures a portion of the view of the radiation beam passing through the first opening (O1). At the second measurement position (2), the sensing surface (S) captures a portion of the view of the radiation beam passing through the second opening (O2). At the third measurement position (3), the sensing surface (S) captures a portion of the view of the radiation beam passing through the third opening (O3). At the fourth measurement position (4), the sensing surface (S) captures a portion of the view of the radiation beam passing through the fourth opening (O4). The lithography apparatus of this embodiment may be configured to move the sensing surface (S) with respect to the radiation beam to each of the measurement positions (1 to 4) to obtain measurements of the radiation beam (B) through each of the apertures (O1, O2, O3, O4). Thus, each of the multiple apertures (O1, O2, O3, O4) may correspond to a measurement position. Additionally, in this embodiment, the multiple apertures (O1, O2, O3, O4) associated with the movement of the sensor surface between the multiple measurement positions may move with respect to the radiation beam. The multiple apertures may move simultaneously with or non-simultaneously with the sensing surface. Additionally, or alternatively, the multiple apertures may move the same distance as the sensing surface or a different distance from the distance the sensing surface moves.

[0070] Multiple openings may be positioned in fixed positions relative to each other. Alternatively, multiple openings may be positioned in movable positions relative to each other, or may be positioned to be movable in groups relative to one or more different groups of multiple openings.

[0071] Multiple openings (O1, O2, O3, O4) can be positioned such that at least one opening at each measurement location is outside the radiation beam, i.e., outside 100% of the view (V) in the plane. This means that the radiation beam must not pass through at least one opening outside the entire view (V). This can reduce noise from radiation passing through multiple openings for a specific measurement location. This is illustrated in FIG. 3a, where the third opening (O3) is outside the radiation beam [and the full view in the plane (V)] at the first measurement position (1), the fourth opening (O4) is outside the radiation beam [and the full view in the plane (V)] at the second measurement position (2), the first opening (O1) is outside the radiation beam [and the full view in the plane (V)] at the third measurement position (3), and the second opening (O2) is outside the radiation beam [and the full view in the plane (V)] at the fourth measurement position (4).

[0072] Optionally, as shown in FIGS. 3c and 3d, the lithography device may include a mask (MK) configured to mask all openings except one of the multiple openings at each measurement location. This can prevent or reduce radiation from entering the measurement device through other openings during these measurements. This may be advantageous for reducing noise by ensuring that the radiation beam incident on the sensing surface passes through only one of the openings. This reduces the possibility of error due to the multiple openings provided and reduces noise. The mask (MK) may be made of any suitable material. The mask (MK) must be made of a material capable of substantially preventing the transmission of radiation through the mask. Ideally, the mask (MK) can mask all but one of the openings, but the mask (MK) may be used to mask only one or more of the openings, for example, the opening closest to the opening used at a specific measurement location. The position of the mask (MK) can be controlled using an actuator of one type (not shown).

[0073] As previously mentioned, the openings may include a grid. In this embodiment, at least one of the multiple openings may include a grid. All openings may include a grid. The grids may be identical. This may be advantageous in that comparisons made by measurements performed by different openings can be made easier, and / or manufacturing may be easier and, consequently, cheaper for identical grids.

[0074] In any one of the preceding embodiments, the sensing surface (S) may be offset in the plan view from the opening through which the radiation beam (B) passes when in use. This means that in the plan view, for example in the XY view shown in FIG. 3a, the sensing surface (S) is not aligned with the opening through which the radiation beam passes at any of the measurement positions. In other words, when a measurement is taken, the center point of the sensing surface (S) may not be aligned with the center point of the opening. For example, at the first measurement position (1), the sensing surface (S) is offset from the first opening (O1) through which the radiation beam passes.

[0075] In another embodiment, the measuring unit may include only a single opening through which a radiation beam passes during use. In this embodiment, the lithography device may be configured to maintain the position of the single opening relative to the radiation beam projected by the projection system between measurements at each of the plurality of measuring positions. This embodiment is illustrated in FIGS. 4a and 4b. As previously described, the lithography device may be configured to move the sensing surface (S) in a plane across the optical axis between the plurality of measuring positions. Five measuring positions are illustrated in FIGS. 4a and 4b. The lithography device may be configured to maintain the position of the single opening (O5) at a substantially constant position, as indicated by a constant position, between the measuring positions (1 to 5) shown in FIGS. 4a and 4b.

[0076] In this embodiment, a plate (PL) comprising only a single opening (O5) may be provided. In this embodiment, the sensing surface (S) is moved relative to other components of the measuring unit (M). At each of the measuring positions, the sensing surface (S) is configured to measure a portion of the view of the radiation beam in a plane across the optical axis to which the sensing surface (S) is moved, and the portion of the view is less than 100% of the view (V). The positions of the radiation beam (B) and the single opening (O5) are maintained at substantially constant positions, and the sensing surface (S) is moved to different measuring positions (1 to 5). Then, the sensing surface (S) measures different portions of the radiation beam (B) at each of the measuring positions (1 to 5). There may be some overlap of the portions of the view measured at each of the measuring positions (1 to 5).

[0077] The lithography device may include an actuator (A) as illustrated in FIG. 4b. The actuator (A) may be part of a measurement system (M). The actuator (A) may be configured to move a sensing surface (S) between a plurality of measurement positions, for example, as illustrated in FIG. 4a and FIG. 4b. The actuator (A) may be provided in any suitable form. For example, the actuator (A) may include a moving part that supports the sensing surface (S) and moves along tracks within the measurement unit (M). The actuator (A) may include a roller system similar to a conveyor belt to move the sensing surface (S) back and forth in the X direction, as shown in FIG. 4b. Any suitable actuator that can be provided in a size small enough to move the sensing surface (S) may be used.

[0078] The sensing surface (S) may be used to perform measurements at any number of measurement positions in any one of the embodiments. The sensing surface (S) may be moved in a stepping mode, where the sensing mode is moved to a measurement position and the measurement is performed when the sensing surface (S) is substantially stationary. Alternatively, the sensing surface may be moved in a scanning mode, which, for example, moves the sensing surface (S) and performs measurements during the movement of the sensing surface (S). If only a single opening is provided, the sensing surface (S) is moved continuously, preferably very slowly, to provide measurements at different measurement positions, that is, so that measurements can be performed at specific timings in scanning mode.

[0079] As previously described, the lithography device may include a processor configured to combine portions of a view captured at a plurality of measurement positions. The processor (PR) is illustrated in FIGS. 3a, 3b, 3c, and 3d. The processor (PR) is not illustrated in FIG. 4a or 4b, but may be provided with this embodiment. The processor (PR) may be positioned anywhere convenient. The processor (PR) may be formed as part of a substrate table (WT).

[0080] Furthermore, the present invention provides a method for measuring a radiation beam. The method may correspond to the aforementioned apparatus as described in more detail below. Additionally, the definitions and descriptions provided in relation to the apparatus may also apply to the method, but may not be repeated below for the sake of brevity. The advantages previously described in relation to the apparatus may equally apply to certain steps of the method.

[0081] The above method is for measuring a radiation beam in a lithography device. The method may include the step of using a lithography device as in any variations and / or embodiments as described above. The method is illustrated in FIG. 5. The method includes the step of providing a radiation beam as in step S1, the step of projecting a radiation beam as in step S2, and the step of measuring a radiation beam as in step S3.

[0082] The radiation beam (B) may be provided and / or projected as previously described. For example, the radiation beam projected by the projection system may follow an optical axis. The device described previously may be used to provide and / or project the radiation beam (B), or other configurations or devices may be used. Generally, the projection system (PS) is any system used to project the radiation beam (B). The method comprises the step of projecting the radiation beam through an opening of the measurement system. The measurement system (M) may be as described in any of the preceding variations or embodiments.

[0083] The measuring step (S3) includes the step of measuring a radiation beam passing through an opening at a plurality of measurement locations using a sensing surface of a measuring system. As previously described, the sensing surface may extend across an optical axis.

[0084] The step of measuring a radiation beam includes moving a sensing surface in a plane that crosses an optical axis between multiple measurement positions. The plane in which the sensing surface is moved may be orthogonal to the optical axis. As previously described, the radiation beam defines a view in the plane, and the sensing surface captures a portion of the view smaller than 100% of the view at each measurement position.

[0085] More specifically, the measurement step may be considered to have a plurality of sub-steps as shown in FIG. 6. As shown, the method may include the step of measuring a radiation beam projected by a projection system at a first measurement location as in step S3A, the step of moving a sensing surface in a plane across an optical axis at a second measurement location as in step S3B, and the step of measuring a radiation beam projected by a projection system at the second measurement location as in step S3C. Additional movement steps may be included to move the sensing surface to other measurement locations where additional measurements can be performed.

[0086] The above method includes the step of moving a sensing surface so that measurements are performed at multiple measurement locations. Accordingly, the method includes the step of changing the position of the sensing surface, and in particular, the step of moving the sensing surface between multiple measurement locations. Thus, the sensing surface can obtain measurements of multiple portions of a radiation beam in the plane in which the sensing surface is moved. The sensing surface can be moved in the plane in various ways as previously described.

[0087] The measurement step may include a step of maintaining the position of a radiation beam projected by a projection system at a substantially constant position when measurements at multiple measurement locations are performed by a sensing surface. Thus, the position of the radiation beam can be maintained substantially constant, and the position of the sensing surface can be changed. This means that the radiation beam can be maintained at a substantially constant position relative to the moving sensing surface. In this way, the sensing surface can be used to measure different portions of the radiation beam in the plane in which the sensing surface moves. The portion of the radiation beam being measured can be determined based on the position of the sensing surface where the measurement is performed.

[0088] Preferably, at least a portion of the view captured by the sensing surface at one measurement location does not overlap with a portion of the view captured by the sensing surface at any of the other measurement locations. As described, it is advantageous to have at least a non-overlapping portion. Additionally, overlap may exist, which can advantageously improve the accuracy of the measurements as previously described.

[0089] The opening may be provided in various different configurations as previously described. The method may include the step of providing a grid to the opening as described. The method may include the step of providing any appropriate number of openings. As in the example described for the device, the method may include the use of a single opening or multiple openings (including the example described earlier which includes four openings). The measuring system may include a plate forming the openings as previously described.

[0090] The above method may further include the step of providing a support table configured to support a measuring unit. The support table may be as described above. As described, the measuring unit may be supported on the surface of the support table (WT) or formed as part of the support table (WT).

[0091] The above method may further include a step of combining portions of a view captured at multiple measurement locations. Ideally, the method includes a step of combining portions to provide a measurement of 100% of the view. As previously described, this means that improved measurements can be made while still using the same sensing surface that may have been used in known sensing devices.

[0092] Preferably, the distance between the opening and the sensing surface is such that 100% of the area of ​​the view in the plane is larger than the sensing surface, i.e., the entire area of ​​the sensing surface. In other words, the sensing surface may be positioned relative to the opening such that the view of the radiation beam in the plane is larger than the sensing surface. There may be a preset minimum distance for a given size of the opening and the sensing surface. Thus, the distance may vary depending on at least these factors.

[0093] The sensing surface, that is, the entire area of ​​the sensing surface, may be about 70% or less of the 100% area of ​​the view. Thus, at any of the measurement locations, the sensing surface may be used to measure about 70% or less of the radiation beam in the plane in which the sensing surface moves, that is, about 70% or less of the entire view. Alternatively, the area of ​​the sensing surface may be smaller. For example, the sensing surface may be about 60% or less of the 100% area of ​​the view, or about 50% or less of the 100% area of ​​the view, or about 30% or less of the 100% area of ​​the view.

[0094] In one embodiment, the measuring unit includes a plurality of openings through which a radiation beam passes when in use. One of the plurality of openings is used for each measurement location. Thus, when a measurement is being performed at a measurement location, the radiation beam may pass through one of the openings and be incident on a sensing surface. In this embodiment, the method further includes the step of moving the plurality of openings and the sensing surface with respect to the radiation beam between measurements at each of the plurality of measurement locations. When the sensing surface and the openings are moved with respect to the radiation beam, the radiation beam may pass through a different one of the openings and be incident on the sensing surface for measurements at different measurement locations. Thus, there may be one opening corresponding to each measurement location. Optionally, the position of the plurality of openings with respect to the sensing surface is maintained when moving the plurality of openings and the sensing surface with respect to the radiation beam.

[0095] In this embodiment, the radiation beam may be measured at a first measurement location as in S3A of FIG. 6. This may correspond, for example, to performing a measurement at the first measurement location in FIG. 3A, 3B, and 3C. Thus, for example, the first measurement may be performed using the first opening (O1). Then, the method may include the step of moving the sensing surface in a plane to another measurement location as in step S3B of FIG. 6. For example, this may correspond to moving the sensing surface and the openings (O1, O2, O3, and O4) (for the radiation beam) to the second measurement location in FIG. 3A and 3B. Then, the radiation beam may be measured at the second measurement location as in S3C of FIG. 6. This may correspond, for example, to performing a measurement at the second measurement location in FIG. 3A, 3B, and 3C. Therefore, for example, the second measurement can be performed using the second opening (O2).

[0096] Multiple openings can be positioned such that at each measurement location, at least one opening is outside the radiation beam, that is, outside 100% of the view in the plane. As previously mentioned, this can reduce noise from radiation passing through the multiple openings for a specific measurement location.

[0097] The above method may further include the step of masking all of the multiple openings, excluding at least one of the openings, or preferably one at each measurement location. As previously described, this may be advantageous for reducing noise. Masking may be performed using a mask (MK).

[0098] The above method may further include the step of providing a grid to at least one of the plurality of openings, or preferably the same grids for the plurality of openings.

[0099] In another embodiment, the measuring unit includes only a single opening through which a radiation beam passes during use. The method further includes the step of maintaining the position of the single opening for the radiation beam projected by the projection system between measurements at each of a plurality of measuring positions. Accordingly, in this embodiment, the sensing surface is moved relative to other components of the measuring unit between measurements of multiple portions of the radiation beam.

[0100] As shown in FIGS. 4a and 4b, the position of the radiation beam (B) and the opening (O5) is maintained at a substantially constant position, and the sensing surface (S) is moved to another measurement position relative to the radiation beam and the opening (O5). Thus, the sensing surface measures different parts of the radiation beam as the sensing surface is moved.

[0101] In this embodiment, the radiation beam may be measured at a first measurement location as in S3A of FIG. 6. This may correspond, for example, to performing a measurement at the first measurement location in FIG. 4a and FIG. 4b where the radiation beam passes through the opening (O5). Then, the method may include the step of moving the sensing surface in a plane to another measurement location as in step S3B of FIG. 6. For example, this may correspond to moving the sensing surface to a second measurement location in FIG. 4a and FIG. 4b. Then, the radiation beam may be measured at a second measurement location as in step S3C of FIG. 6. This may correspond, for example, to performing a measurement at the second measurement location in FIG. 4a and FIG. 4b where the radiation beam passes through the opening (O5).

[0102] While this specification describes specific uses of lithography devices in IC manufacturing, it should be understood that the lithography devices described herein may have other applications, such as the manufacturing of integrated optical systems, guide and detection patterns for magnetic domain memory, flat panel displays, liquid crystal displays (LCDs), thin film magnetic heads, etc. Those skilled in the art will understand that, in relation to these alternative applications, any use of the terms “wafer” or “die” in this specification may be considered synonymous with the more general terms “substrate” or “target part,” respectively. The substrates mentioned in this specification may be processed before and after exposure, for example, by a track (typically a tool that applies a resist layer to a substrate and develops the exposed resist), a metrology tool, and / or an inspection tool. Where applicable, the description in this specification may be applied to these substrate processing tools and other substrate processing tools. In addition, since a substrate may be processed one or more times to create, for example, a multilayer IC, the term "substrate" as used in this specification may refer to a substrate comprising layers that have already been processed multiple times.

[0103] The terms “radiation” and “beam” as used herein encompass all forms of electromagnetic radiation, including particle beams such as ion beams or electron beams, as well as ultraviolet (UV) radiation (e.g., having wavelengths of 365, 248, 193, 157 or 126 nm, or similar wavelengths) and extreme ultraviolet (EUV) radiation (e.g., having wavelengths within the range of 5 to 20 nm).

[0104] The term “lens” as permitted by this specification may refer to any one or a combination of various forms of optical components, including refractive, reflective, magnetic, electromagnetic, and electrostatic optical components.

[0105] The foregoing description is for illustrative purposes only and is not intended to be limiting. Accordingly, those skilled in the art will understand that variations of the present invention described below may be made without departing from the scope of the claims set forth below.

[0106] Former embodiments and / or alternative embodiments and / or complementary embodiments of the present invention may be represented as described in the following items:

[0107] 1. As a lithography device,

[0108] A projection system configured to project a radiation beam having an optical axis; and

[0109] It includes a measuring unit positioned to measure a radiation beam projected by a projection system, and the measuring unit is:

[0110] An opening through which a radiation beam passes when in use; and

[0111] It includes a sensing surface positioned to measure a radiation beam extending across an optical axis and passing through an opening, and

[0112] The lithography device is configured to move a sensing surface in a plane traversing an optical axis between multiple measurement positions, and

[0113] The radiation beam defines a view in the above plane, and

[0114] A lithography device in which a measuring unit is configured such that a sensing surface captures a portion of the view smaller than 100% of the view at each measuring position.

[0115] 2. The lithography device in claim 1, wherein the lithography device is configured to maintain the position of a radiation beam projected by a projection system at a substantially constant position when the sensing surface is configured to measure a radiation beam at a plurality of measurement positions.

[0116] 3. A lithography device in which, in claim 1 or 2, at least a portion of the view captured by a sensing surface at one measurement location does not overlap with a portion of the view captured by a sensing surface at any one of the other measurement locations.

[0117] 4. A lithography apparatus in any one of claims 1 to 3, wherein the opening comprises a grid.

[0118] 5. In any one of claims 1 to 4, the measuring unit is a lithography device provided on a support table.

[0119] 6. A lithography apparatus in any one of claims 1 to 5, wherein the radiation beam projected by the projection system follows an optical axis and the plane in which the sensing surface moves is orthogonal to the optical axis.

[0120] 7. In any one of claims 1 to 6, the lithography device is configured to combine portions of a view captured at a plurality of measurement positions to provide a measurement of 100% of the view in the plane.

[0121] 8. A lithography apparatus in any one of claims 1 to 7, wherein the distance between the opening and the sensing surface is such that the area of ​​100% of the view in the plane is larger than the sensing surface.

[0122] 9. A lithography apparatus in which, in claim 8, the sensing surface is about 70% or less of the 100% area of ​​the view in the plane, or about 60% or less of the 100% area of ​​the view in the plane, or about 50% or less of the 100% area of ​​the view in the plane, or about 30% or less of the 100% area of ​​the view in the plane.

[0123] 10. A lithography device in any one of claims 1 to 9, wherein the measuring unit comprises a plurality of openings through which a radiation beam passes when in use, one of the openings is used at each measurement position, and the lithography device is configured to move the plurality of openings across an optical axis in conjunction with the movement of the sensor surface between the plurality of measurement positions.

[0124] 11. In claim 10, a lithography device in which a plurality of openings are located at fixed positions relative to a sensing surface.

[0125] 12. A lithography device in which, in claim 10 or 11, a plurality of openings are arranged such that at least one opening is outside the radiation beam at each measurement location.

[0126] 13. In any one of claims 10 to 12, the lithography device comprises a mask configured to mask all openings except one of a plurality of openings at each measurement location.

[0127] 14. A lithography apparatus in any one of claims 10 to 13, wherein a plurality of openings comprise identical grids.

[0128] 15. A lithography device in any one of claims 1 to 9, wherein the measuring unit comprises only a single opening through which a radiation beam passes when in use, and the lithography device is configured to maintain the position of the single opening for a radiation beam projected by a projection system between measurements at each of a plurality of measuring positions.

[0129] 16. A method for measuring a radiation beam in a lithography device,

[0130] Step of providing a radiation beam;

[0131] A step of projecting a radiation beam through an opening of a measurement system using a projection system having an optical axis; and

[0132] The method includes the step of measuring a radiation beam passing through an opening at multiple measurement locations using a sensing surface of a measuring system, wherein the sensing surface extends across an optical axis, and

[0133] The step of measuring a radiation beam includes the step of moving a sensing surface in a plane across an optical axis between a plurality of measurement positions, and

[0134] The radiation beam defines a view in the above plane, and

[0135] A method in which a sensing surface captures a portion of the view smaller than 100% of the view at each measurement location.

[0136] 17. A method in which, in the case of claim 16, the measuring step includes the step of maintaining the position of a radiation beam projected by a projection system at a substantially constant position when measurements at a plurality of measurement positions are being taken by a sensing surface.

[0137] 18. A method in which, in claim 16 or 17, at least a portion of the view captured by the sensing surface at one measurement location does not overlap with a portion of the view captured by the sensing surface at any one of the other measurement locations.

[0138] 19. A method in any one of claims 16 to 18, further comprising a 1D or 2D pattern, such as a grid, in the opening.

[0139] 20. A method comprising, in any one of claims 16 to 19, further providing a support table, wherein a measuring unit is provided on the support table.

[0140] 21. A method in any one of claims 16 to 20, wherein the radiation beam projected by the projection system follows an optical axis and the plane in which the sensing surface moves is orthogonal to the optical axis.

[0141] 22. A method comprising, in any one of claims 16 to 21, further combining portions of a view captured at a plurality of measurement positions to provide a measurement of 100% of the view in the plane.

[0142] 23. A method in any one of claims 16 to 22, wherein the distance between the opening and the sensing surface is such that 100% of the area of ​​the view in the plane is larger than the sensing surface.

[0143] 24. A method in which, in claim 23, the sensing surface is about 70% or less of the 100% area of ​​the view, or about 60% or less of the 100% area of ​​the view, or about 50% or less of the 100% area of ​​the view, or about 30% or less of the 100% area of ​​the view.

[0144] 25. A method in any one of claims 16 to 24, wherein the measuring unit comprises a plurality of openings through which a radiation beam passes when in use, and one of the openings is used at each measuring position, and the method further comprises the step of moving the plurality of openings and the sensing surface with respect to the radiation beam between measurements at each of the plurality of measuring positions.

[0145] 26. In paragraph 25, the position of the multiple openings on the sensing surface is maintained when the multiple openings and the sensing surface are moved relative to the radiation beam.

[0146] 27. A method in which, in claim 25 or 26, a plurality of openings are arranged such that at least one opening at each measurement location is outside the radiation beam.

[0147] 28. A method comprising, in any one of claims 25 to 27, further a step of masking all openings except one of the plurality of openings at each measurement location.

[0148] 29. A method in any one of claims 25 to 28, wherein a plurality of openings comprise identical grids.

[0149] 30. A method in any one of claims 16 to 24, wherein the measuring unit comprises only a single opening through which a radiation beam passes when in use, and the method further comprises the step of maintaining the position of the single opening for a radiation beam projected by a projection system between measurements at each of a plurality of measuring positions.

Claims

Claim 1 A sensing device for a lithography apparatus comprising a measuring unit positioned to measure a radiation beam projected by a projection system having an optical axis, wherein the measuring unit comprises: an opening through which the radiation beam passes when in use; and a sensing surface extending across the optical axis and positioned to measure the radiation beam passing through the opening, wherein the sensing surface is movable in a plane across the optical axis between a plurality of measuring positions, and the radiation beam defines a view in the plane, and the sensing device is configured such that the sensing surface captures a portion of the view that is smaller than 100% of the view at each measuring position. Claim 2 A method for measuring a radiation beam by a sensing device for a lithography device, comprising the step of measuring a radiation beam passing through an opening in a measuring system in which the radiation beam is projected using a projection system having an optical axis at a plurality of measuring positions using a sensing surface of a measuring system, wherein the sensing surface extends across the optical axis, and the step of measuring the radiation beam comprises the step of moving the sensing surface in a plane across the optical axis between the plurality of measuring positions, wherein the radiation beam defines a view in the plane, and the sensing surface captures a portion of the view smaller than 100% of the view at each measuring position. Claim 3 In claim 1, the sensing device is configured to maintain the position of the radiation beam projected by the projection system at a substantially constant position when the sensing surface is configured to measure the radiation beam at the plurality of measurement positions. Claim 4 A sensing device according to claim 1, wherein at least a portion of the view captured by the sensing surface at one measurement location does not overlap with the portion of the view captured by the sensing surface at any one of the other measurement locations. Claim 5 A sensing device according to claim 1, wherein a 1D or 2D pattern, such as a grid, is provided in the opening. Claim 6 In claim 1, the measuring unit is a sensing device provided on a support table. Claim 7 A sensing device according to claim 1, wherein the radiation beam projected by the projection system follows the optical axis, and the plane on which the sensing surface moves is orthogonal to the optical axis. Claim 8 In claim 1, the sensing device is configured to combine portions of a view captured at a plurality of measurement positions to provide a measurement of 100% of the view in the plane. Claim 9 A sensing device according to claim 1, wherein the distance between the opening and the sensing surface is such that the area of ​​100% of the view in the plane is larger than the sensing surface. Claim 10 A sensing device according to claim 9, wherein the sensing surface is 70% or less of the 100% area of ​​the view in the plane, or 60% or less of the 100% area of ​​the view in the plane, or 50% or less of the 100% area of ​​the view in the plane, or 30% or less of the 100% area of ​​the view in the plane. Claim 11 In claim 1, the measuring unit comprises a plurality of openings through which the radiation beam passes when in use, one of the openings is used at each measurement position, and the sensing device is configured to move the plurality of openings across the optical axis in conjunction with the movement of the sensor surface between the plurality of measurement positions. Claim 12 In claim 11, the plurality of openings are a sensing device located at a fixed position relative to the sensing surface. Claim 13 In claim 11, the detection device wherein the plurality of openings are arranged such that at least one opening is outside the radiation beam at each measurement location. Claim 14 In claim 11, the sensing device comprises a mask configured to mask all openings except one of the plurality of openings at each measurement location. Claim 15 In claim 11, the plurality of openings are a sensing device comprising identical grids. Claim 16 In claim 1, the measuring unit comprises only a single opening through which the radiation beam passes when in use, and the sensing device is configured to maintain the position of the single opening relative to the radiation beam projected by the projection system between measurements at each of the plurality of measuring positions. Claim 17 A lithography device comprising a sensing device according to any one of claims 1 or 3 to 16.

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