KR20210020027A - Device for imaging objects in multiple locations - Google Patents

Abstract

A system for imaging an object at any one of a plurality of locations 400; 410 is disclosed, the system comprising: one or more beam dividers 420 that divide light from the object into an imaging beam and a continuous beam; And an optical mechanism for each beam splitter that receives an imaging beam and images the object when the object is in each position.

Description

Device for imaging objects in multiple locations

This application claims priority to U.S. Provisional Patent Application 62/684,839, filed June 14, 2018, which is hereby incorporated by reference in its entirety.

The present disclosure relates to an optical system that can be used in a semiconductor photolithography alignment system.

A lithographic apparatus applies a desired pattern onto a substrate, usually a target portion of the substrate. Lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs). In that application, a patterning device (also referred to as a mask or reticle) is used to create circuit patterns that will be formed on individual layers of the IC. This pattern can be transferred onto a target portion (including a portion of one die, or multiple dies) on a substrate (eg, a silicon wafer). The transfer of the pattern is generally through imaging onto a layer of a radiation sensitive material (resist) provided on the substrate. In general, a single substrate will contain a network of adjacent target portions that are successively patterned.

The known lithographic apparatus comprises a so-called stepper, in which the entire pattern is exposed onto the target portion at a time to irradiate each target portion, and the known lithographic apparatus also includes a so-called scanner, in which , Each target portion is irradiated by scanning the pattern through the radiation beam in a given direction ("scanning" direction) and also synchronously scanning the substrate parallel or antiparallel to that direction. It is also possible to transfer the pattern from the patterning device to the substrate by imprinting the pattern onto the substrate.

During lithography, a reticle is used to transfer the desired pattern onto a substrate such as a wafer. The reticle may be formed of material(s) that pass through the lithographic wavelength used, for example glass in the case of visible light. Additionally, the reticle may be formed of material(s) that reflect the selected lithographic wavelength for the particular system in which it is used. An illumination source (e.g., exposure optics located inside the lithographic apparatus) illuminates the reticle, which is placed on the reticle stage. By this illumination, an image is exposed on a substrate placed on a substrate stage. The image exposed on the substrate corresponds to the image printed on the reticle. In the case of lithography, an exposure optical apparatus is used, but other types of exposure apparatus may also be used depending on the specific application. For example, each of x-ray, ion, electron or photon lithography may require a different exposure apparatus, as known to those skilled in the art. Specific examples of photolithography will be discussed here for illustrative purposes only.

The reticle is usually placed between the semiconductor chip and the light source. A loading process is required for loading the reticle onto the reticle exposure stage. The reticle must be aligned very precisely in a predetermined position. Alignment errors must be within the correctable compliance range. Typically, alignment marks formed on the reticle are used to position the alignment marks to align the reticle. The alignment operation is performed by detecting the alignment marks on the reticle.

Preliminary alignment, ie reticle alignment in an offline alignment station, is desirable to shorten the reticle replacement time and thus increase the throughput of the lithographic system. Once the reticle is placed on the platen, reticle preliminary alignment marks are used to place the reticle in approximately the correct position. By moving the stage, a special alignment mark attached to the stage is placed in an accurate position to perform fine alignment of the reticle. The mark is illuminated with a HeNe laser, for example. The reticle is then moved to give the best alignment position and remains in that position until it is removed from the stepper/scanner.

Typically, the reticle pre-alignment system is capable of imaging the reticle at a single predetermined working height. However, it may be advantageous to have the flexibility to image reticles that are not only one height, but also additional heights. Therefore, there is a need for a system capable of imaging a reticle at any of a number of possible working heights.

In the following, a brief summary of one or more embodiments is given to provide a basic understanding of the embodiments. This summary is not an extensive overview of all contemplated embodiments, nor is it intended to identify key or important elements of all embodiments, nor to impose limitations on the scope of any or all embodiments. Its sole purpose is to briefly present some concepts of one or more embodiments prior to the more detailed description that is presented later.

According to one aspect of an embodiment, a system for imaging an object in a first position or a second position is disclosed, the system comprising: a beam divider that divides light from the object into a first beam and a second beam; An optical device that receives the first beam and forms an image of the object when the object is in the first position; And another optical mechanism that receives the second beam and images the object when the object is in the second position.

According to another aspect of the embodiment, an apparatus for imaging an object in one of a first position and a second position is disclosed, the device being arranged to receive light from the object and also receiving light from the first beam and the second position. A beam divider for dividing into two beams; A first optical element arranged to receive the first beam; And a second optical element arranged to receive the folding mirror and the second beam. The apparatus further includes a third optical element optically arranged between the beam splitter and the first optical element, and a fourth optical element optically arranged between the folding mirror and the second optical element. The device may further comprise a third optical element optically disposed between the object and the beam splitter.

According to another aspect of one embodiment, a device for imaging an object in one of a first position and a second position is disclosed, the device being arranged to receive light from the object and also passing the light across the first arm. A beam divider for dividing into a first beam and a second beam; And a folding mirror disposed to receive the second beam and reflect the second beam to the second arm, the first arm comprising: a first optical element disposed to receive the first beam, and from the first optical element A second optical element disposed to receive the first beam, the second arm, a third optical element disposed to receive the reflected second beam, and a fourth optic disposed to receive the second beam from the third optical element Contains elements.

According to another aspect of one embodiment, an apparatus for imaging an object in one of a first position and a second position is disclosed, the apparatus comprising: a first optical element arranged to receive light from the object; A beam splitter arranged to receive light from the first optical element and for dividing the light into a first beam and a second beam traversing the first arm, the first arm comprising a second optical element arranged to receive the first beam box); And a third optical element arranged to receive the folding mirror and the second beam.

According to another aspect of the embodiment, an apparatus for imaging an object in one of a first position and a second position is disclosed, the apparatus comprising: splitting light from the object into a first beam and a second beam. A beam divider disposed; A first optical system arranged to receive the first beam and image the object when the object is in the first position; And a second optical system arranged to receive the second beam and image the object when the object is in the second position. The first optical system includes a first optical element and a second optical element, and the second optical system includes a folding mirror, a third optical element and a fourth optical element. The apparatus further comprises a first optical element optically disposed between the object and the beam splitter, the first optical system comprising a second optical element, and the second optical system comprising a folding mirror and a third optical element. do.

According to another aspect of one embodiment, a device for imaging an object in a first position or a second position is disclosed, the device comprising: a first beam and a second beam of light from the object along a first optical path. A beam divider arranged to divide into; A first optical module arranged to receive the first beam and image the object when the object is in the first position; And a second optical module arranged to receive the second beam and image the object when the object is in the second position.

According to another aspect of the embodiment, an apparatus for imaging an object in one of a first position and a second position is disclosed, the apparatus comprising: at a first working distance WD1 from a first position and a second A first optical element arranged to receive light from the object at a second working distance WD2 from the location; And a beam splitter arranged to receive light from the first optical element and for dividing the light into a first beam and a second beam traversing the first arm, wherein the first arm is arranged to receive the first beam and is focused A first arm lens group having a length F1' is included, and the second beam includes a first lens and a second lens separated from each other by a distance d, and a second lens having a focal length F2' Crossing the arm lens group, WD1, WD2, F2' and F1' satisfy the following relationship,

Where k is a coefficient ranging from about 1 to about 4.

According to another aspect of one embodiment, an apparatus for imaging an object at any one of a plurality of locations is disclosed, the apparatus being arranged to receive light from the object and also directing the light to a first beam and a second beam. A first optical branching (bLifurcation) module including a first beam splitter for dividing, and a first imaging module for imaging an object and arranged to receive a second beam when the object is at the farthest position among the plurality of positions; And an additional beam divider arranged to receive light from the first beam, and for dividing the light into an imaging beam and a continuous beam, and arranged to receive an imaging beam when the object is in a different position among the plurality of positions, and to image the object. And at least one additional optical branching module comprising an additional imaging module for, wherein the continuous beam proceeds to one of the next additional optical branching module and the final optical module arranged to receive light from the continuous beam, and the final optical module And a folding mirror, and a final optical imaging module arranged to receive the second beam when the object is at the closest position among the plurality of positions, and for imaging the object.

Additional embodiments, features, and advantages of the subject matter of the present disclosure, and structures and operations of various embodiments will be described in detail below with reference to the accompanying drawings.

1 shows a lithographic apparatus according to an aspect of an embodiment of the present invention.
2 shows a pre-alignment system configured to pre-align a reticle, according to an aspect of an embodiment of the present invention.
3 is a diagram of an optical system for imaging a reticle in a single position.
4A is a diagram of an optical system for imaging a reticle in two positions as an example of a plurality of positions according to an aspect of an embodiment of the present invention.
4B is a diagram of an optical system for imaging a reticle in multiple locations in accordance with an aspect of an embodiment of the present invention.
5 is a diagram of an optical system for imaging a reticle in multiple locations according to an aspect of an embodiment of the present invention.
Additional features and advantages of the present invention, and the structure and operation of various embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that the present invention is not limited to the specific embodiments described herein. Such embodiments are given here for illustrative purposes only. Additional embodiments will be apparent to those skilled in the art based on the teachings contained herein.

Various embodiments will now be described with reference to the drawings, in which like reference numerals designate like elements throughout. In the following description, many specific details are given for illustrative purposes in order to facilitate a thorough understanding of one or more embodiments. However, in any or all cases, it is clear that the embodiments described below may be practiced without adopting the specific design details described below. In the following description and claims, terms such as "top", "bottom", "top", "bottom", "vertical", "horizontal" and the like may be used. Unless otherwise stated, these terms are intended to indicate relative orientation only, not orientation to gravity.

1 schematically shows a lithographic apparatus 100 according to an embodiment of the invention. The apparatus includes an illumination system (illuminator) IL configured to regulate a radiation beam B (eg, UV radiation or EUV radiation); A support structure or a support or a pattern support (e.g., a support structure configured to support the patterning device (e.g., a mask) MA, and connected to a first positioner PM, configured to accurately position the patterning device according to a specific parameter) Mask table) (MT); A substrate table (e.g., a wafer table) configured to hold a substrate (e.g., a resist coated wafer) W and connected to a second positioner PW configured to accurately position the substrate according to a specific parameter ( WT); And a projection system configured to project a pattern imparted to the radiation beam B by the patterning device MA onto a target portion C of the substrate W (e.g., including one or more dies). Refractive Projection Lens System) (PS).

The illumination system may include various types of optical elements, such as refractive, reflective, magnetic, electromagnetic, electrostatic or other types of optical elements or combinations thereof for guiding, shaping or controlling radiation.

The support structure holds the patterning device according to other conditions such as the orientation of the patterning device, the design of the lithographic device, and whether the patterning device is held in a vacuum environment, for example. The support structure can use mechanical, vacuum, electrostatic or other clamping techniques to support the patterning device. The support structure can be, for example, a frame or a table that can be fixed or movable as required. The support structure can ensure that the patterning device is in the desired position, for example for the projection system. Here, the use of the terms “reticle” or “mask” may be considered synonymous with the more general term “patterning device”.

The term "patterning device" as used herein should be broadly interpreted as referring to any device that can be used to impart a pattern to the cross section of a radiation beam so as to form a pattern on a target portion of the substrate. For example, it should be noted that if the pattern comprises a phase shift feature or a so-called auxiliary feature, the pattern imparted to the radiation beam may not exactly match the desired pattern in the target portion of the substrate. In general, the pattern imparted to the radiation beam will correspond to a particular functional layer in a device being formed in the target portion, such as an integrated circuit.

The patterning device may be transmissive or reflective. Examples of patterning devices include masks, programmable mirror arrays, and programmable LCD panels. Masks are well known in lithography and include mask types such as binary, alternating phase shift, and attenuated phase shift, and various hybrid mask types. An example of a programmable mirror array uses a matrix arrangement of small mirrors, each mirror can be individually tilted to reflect an incident radiation beam in a different direction. The tilted mirror imparts a pattern to the beam of radiation reflected by the mirror matrix.

As used herein, the term "projection system" is a refractive, reflective, catadioptric, magnetic, electronic, suitable for exposure radiation used or suitable for the use of immersion liquids or other factors such as the use of vacuum. It should be interpreted broadly to include any kind of projection system, including parametric, electrostatic optical systems, or combinations thereof. The use of the term "projection lens" here can be considered synonymous with the more general term "projection system".

The support structure and the substrate table may be referred to as an article support hereinafter. Articles include, but are not limited to, patterning devices such as reticles and substrates such as wafers.

As described herein, the lithographic apparatus is of a reflective type (eg, using a reflective mask). Alternatively, the lithographic apparatus may be transmissive (eg, using a transmissive mask).

A lithographic apparatus may be of a type having two (dual stage) or more substrate tables (and/or two or more mask tables). In such "multi-stage" machines, additional tables may be used in parallel, or while one or more other tables are being used for exposure, a preparatory step may be performed on one or more tables.

The lithographic apparatus may be of a kind in which at least a portion of the substrate can be covered with a liquid (eg, water) having a relatively high refractive index to fill the space between the projection system and the substrate. The immersion liquid may be applied to another space of the lithographic apparatus, such as between the mask and the projection system. Immersion techniques for increasing the numerical aperture of projection systems are well known in the art. The term “immersion” as used herein does not mean that a structure such as a substrate must be submerged in a liquid, but means that the liquid is placed between the projection system and the substrate during exposure.

Referring to FIG. 1, the illuminator IL receives a radiation beam from a radiation source SO. For example, when the radiation source is an excimer laser, the radiation source and the lithographic apparatus may be separate from each other. In this case, the radiation source is not considered to form part of the lithographic apparatus, and the radiation beam is transmitted from the radiation source SO to the illuminator IL with the aid of a beam delivery system, which delivery system is for example a suitable guide mirror and/or Or a beam expander. In other cases, for example, if the radiation source is a mercury lamp, the radiation source may be an integral part of the lithographic apparatus. The radiation source SO and illuminator IL can be referred to as a radiation system, together with a beam delivery system, if necessary.

The illuminator IL may include a adjuster for adjusting the angular intensity distribution of the radiation beam. In general, at least the outer and/or inner radial extent of the intensity distribution in the pupil plane of the illuminator (commonly referred to as σ-outside and σ-inside, respectively) can be adjusted. Additionally, the illuminator IL may include various other components such as an integrator and a concentrator. An illuminator can be used to adjust the radiation beam to have the required uniformity and intensity distribution in its cross-section.

The radiation beam B is incident on the patterning device (eg, mask) MA held on the support structure (eg, mask table) MT, and is patterned by the patterning device. The radiation beam B, after being reflected by the patterning device (e.g., mask) MA, passes through the projection system PS, which projects the beam onto the target portion C of the substrate W. Focus. With the aid of the second position setter PW and the position sensor IF2 (e.g., an interferometric device, a linear encoder or a capacitive sensor), the substrate table WT is for example a different target portion C as a radiation beam B ) Can be moved precisely to position it in the path. Similarly, for example, after mechanical recovery from the mask library or during a scan, the first positioner (PM) and other positions to accurately position the patterning device (e.g., mask) (MA) relative to the path of the radiation beam (B). Sensor (IF1) can be used. In general, the movement of the support structure (e.g., mask table) MT can be achieved with the help of a long-stroke module (approximate positioning) and a short-stroke module (fine positioning), and these modules are a first positioning device. It forms part of (PM). Similarly, the movement of the substrate table WT can be accomplished using a long-stroke module and a short-stroke module, which modules form part of the second positioner PW. In the case of a stepper (as opposed to a scanner), the support structure (eg, a mask table) MT may be connected or fixed only to a single stroke actuator. The patterning device (eg, mask) MA and the substrate W may be aligned using mask alignment marks M1 and M2 and substrate alignment marks P1 and P2. The illustrated substrate alignment mark occupies a dedicated target portion, but the substrate alignment mark may be located in the space between the target portions (these are known as scribe-lane alignment marks). Similarly, if more than one die is provided in the patterning device (eg, mask) MA, the mask alignment marks may be located between the dies.

2 illustrates a system 200 configured to pre-align reticle 202, according to an embodiment of the present invention. The system 200 includes an illumination source 208 and a preliminary alignment system 206, and the preliminary alignment system may include a number of optical instruments 212, optical detectors 214, and controller 216. .

The illumination source 208 is configured to illuminate the reticle 202 with light of a predetermined wavelength used for preliminary reticle alignment. In one embodiment, the light generated by illumination source 208 is in the near infrared range of 650 nm-1000 nm. In other embodiments, 880 nm wavelength light is used. As those skilled in the art will appreciate, the wavelength of light generated by the illumination source 208 for reticle alignment will be a design choice. In this embodiment, the illumination source 208 includes dual light sources 208a and 208b. In alternative embodiments, the illumination source 208 may include a single light source or more than two light sources. As those skilled in the art will understand, the number of light sources will be a design choice. The illumination source 208 generates radiation beams 209a, 209b, which are used to illuminate the alignment targets 204a, 204b of the reticle 202. Imaging beams 210a and 210b are generated by the interaction of the beams 209a and 209b and the alignment target 204, which are directed into the preliminary alignment system 206. The imaging beams 210a and 210b are directed by an optical instrument 212 onto an optical detector 214 controlled by a controller 216. The controller 216 generates a control signal 218, which is used to pre-align the reticle 202 based on the imaging beams 210a and 210b. According to one aspect of one embodiment, reticle 202 is a reflective patterning device used in extreme ultraviolet lithography (EUV). According to one aspect of an embodiment, as shown in FIG. 1, the reticle 202 is a reticle (MA) and the alignment targets 204a, 204b are alignment targets M1, M2. A similar system can be used for a transmissive patterning device in which illuminators 209a and 209b are disposed above reticle 202.

3 is a diagram of a system for imaging an object (eg, a reticle) at a single object location 300. The system of Fig. 3 is telecentric in which the main rays are collimated and parallel to the optical axis in image and/or object space. One important feature of the telecentric feature is a constant magnification independent of the image and/or object location. Light from the first optical system (lens group) 310 and the object partially focused by the optical path is folded by the folding mirror 320. The light in the folded optical path is then further focused by the second optical system (lens group) 330 and imaged at the image plane 340.

The system of Fig. 3 is useful for imaging objects that can only be positioned at a single height relative to the optical system. However, as mentioned, it is advantageous to minimize the time required for pre-alignment by shortening or eliminating steps in the pre-alignment procedure, if possible. One technique for this minimization involves increasing the height (working distance) for a conventional reticle pre-alignment system and also adding a second reticle position to the second working distance. In order to satisfy this requirement, according to one aspect of an embodiment, a multi-channel optical configuration is used. The multi-channel optical configuration includes a number of optical branches that partially share an optical path.

According to one aspect of an embodiment, in one configuration referred to herein as a stacked configuration, a passive element such as a beam divider and a folding mirror is in the object space, and there are no shared active optical elements (e.g., lens groups) in the shared object space. The stacked version of the system uses two identical branches or arms that share a common object space. In another configuration, here referred to as a branching configuration, some active optical elements are in the shared (common) part of the path and are therefore shared. This has the advantage that the design can be made more compact and also uses fewer lenses.

4A is a diagram of a stacked system for imaging an object (eg, a reticle) in multiple locations, ie at a high object location 400 or a low object location 410. The system of Fig. 4 is telecentric in which the main rays are collimated and parallel to the optical axis in image and/or object space. The light emitted from the object is split by a beam splitter 420 (eg, a 50%/50% split mirror), which splits the beam into an upper arm and a lower arm. Along the upper arm, there are a first upper arm lens group 430 and a second upper arm lens group 440, and when the object is in a high position 400, these upper arm lens groups can draw the object from the image plane 450. Together. The lower arm is folded by a folding mirror 460 that directs light to the first lower arm lens group 470 and the second lower arm lens group 480, and when the object is in the lower position 410, these lower sides The arm lens group images the object together at the image plane 490.

If necessary, in general, the number of branches can be more than two for both a stacked configuration and a branched (multi-branched) configuration. Also, different magnifications can be formed into different branches. 4B shows an object (e.g., a reticle) in a number of positions, i.e. at a high object position 400, an intermediate position 400', a low object position 410, or another position marked with a solid circle at the top of the degree. It is a diagram of a stacked system for imaging. The system of FIG. 4B is telecentric in which the principal rays are collimated and parallel to the optical axis in image and/or object space. The light emitted from the object is split by a beam splitter 420 (eg, a 50%/50% split mirror), which splits the beam into an upper arm and a lower arm. Along the upper arm, there are a first upper arm lens group 430 and a second upper arm lens group 440, and when the object is in a high position 400, these upper arm lens groups can draw the object from the image plane 450. Together. The light from the object is divided again by a beam splitter 420' (e.g., a 50%/50% split mirror), which splits the beam into a middle arm and a continuous arm. There are a first intermediate arm lens group 430 ′ and a second intermediate arm lens group 440 ′ along the intermediate arm, and when the object is in the intermediate position 400 ′, these intermediate arm lens groups refer the object to the image plane ( 450'). The lower arm is folded by a folding mirror 460 that directs light to the first lower arm lens group 470 and the second lower arm lens group 480, and when the object is in the lower position 410, The arm lens group images the object together at the image plane 490. The solid circle in the lower part of the figure indicates that an additional arm for imaging the object at an additional position may also be included.

5 is a diagram of a branching system for imaging an object (eg, a reticle) at a high object position 500 or a low object position 510. The system of FIG. 5 is telecentric in which the main rays are collimated and parallel to the optical axis in image and/or object space. The light from the object enters the front shared lens group 520 and is then split by a beam splitter 530 (e.g., a 50%/50% split mirror), which splits the light beam into an upper arm and a lower arm. do. There is an upper arm back lens group 540 along the upper arm, and when the object is in a high position 500, the upper arm back lens group forms an image of the object on the image plane 550. The lower arm is folded by a folding mirror 560 that directs light to the lower arm lens group 570, and when the object is in a low position 510, the lower arm lens group will position the object at the image plane 580. Phase out.

In this configuration, the front lens group 520 is common for different working distances WD1 and WD2. The difference between these working distances (ΔWD = WD1-WD2) can be chosen larger than the depth of field and can also be larger than WD2.

The relationship between the focal length and the working distances WD1 and WD2 of the back lens groups 540 and 570 may be defined by the following equation:

Here, F2' is the focal length of the back lens group 570 of the short pass (WD2), F1' is the focal length of the back lens group 540 of the long pass (WD1), and k is ΔWD and the back lens group 570 is a coefficient that depends on the distance d between the two parts, and is in the range of about 1 to about 4.

As an example, for ΔWD> WD2, let WD1 = 75.5 mm and WD2 = 35.5 mm. In this case, the above equation becomes:

In another example, WD1 = 66 mm and WD2 = 26 mm. In this case, the above equation becomes:

In this case, since the distance between the two parts in the back lens group 570 is changed, it is necessary to note the change of the focal length F2' and the focal length of the back lens group 570 of the short path WD2.

Embodiments may be further described using the following terms:

1. As a device for imaging an object in one of the first position and the second position,

A beam divider disposed to receive light from the object and for dividing the light into a first beam and a second beam;

A first optical element arranged to receive the first beam;

A device for imaging an object, comprising a device comprising a folding mirror and a second optical element arranged to receive the second beam.

2. The method of claim 1, further comprising a third optical element optically arranged between the beam splitter and the first optical element, and a fourth optical element optically arranged between the folding mirror and the second optical element. , A device for imaging an object.

3. The apparatus of claim 1, further comprising a third optical element optically disposed between the object and the beam splitter.

4. A device for imaging an object in one of the first position and the second position,

A beam divider disposed to receive light from the object and for dividing the light into a first beam and a second beam traversing the first arm; And a folding mirror disposed to receive the second beam and reflect the second beam to the second arm,

The first arm includes a first optical element arranged to receive a first beam, and a second optical element arranged to receive a first beam from the first optical element,

The second arm comprises a third optical element arranged to receive a reflected second beam, and a fourth optical element arranged to receive a second beam from the third optical element.

5. As a device for imaging an object in one of the first position and the second position,

A first optical element arranged to receive light from the object;

A beam splitter arranged to receive light from the first optical element and for dividing the light into a first beam and a second beam traversing the first arm, a second optical element arranged to receive the first beam Includes -; And

A device for imaging an object, comprising a device comprising a folding mirror and a third optical element arranged to receive the second beam.

6. As a device for imaging an object in one of the first position and the second position,

A beam divider arranged to divide the light from the object into a first beam and a second beam;

A first optical system arranged to receive the first beam and image the object when the object is in the first position; And

And a second optical system arranged to receive the second beam and image the object when the object is in a second position.

7. The object of claim 6, wherein the first optical system comprises a first optical element and a second optical element, and the second optical system comprises a folding mirror, a third optical element and a fourth optical element. A device for image formation.

8. The method of claim 6, further comprising a first optical element optically disposed between the object and the beam splitter, wherein the first optical system comprises a second optical element, and the second optical system is a folding mirror. And a third optical element.

9. An apparatus for imaging an object in a first position or a second position,

A beam splitter arranged to split light traveling from the object to the first optical path into a first beam and a second beam;

A first optical module disposed to receive the first beam and image the object when the object is in the first position; And

And a second optical module arranged to receive the second beam and image the object when the object is in a second position.

10. A device for imaging an object in one of the first position and the second position,

A first optical element arranged to receive light from the object at a first working distance WD1 from the first position and at a second working distance WD2 from the second position; And

A beam splitter arranged to receive light from the first optical element and for dividing the light into a first beam and a second beam traversing the first arm,

The first arm includes a first arm lens group disposed to receive the first beam and having a focal length F1', and the second beam includes a first lens and a first lens separated from each other by a distance d. Traversing a second arm lens group including 2 lenses and having a focal length (F2'), WD1, WD2, F2' and F1' satisfy the following relationship,

Wherein k is a coefficient in the range of about 1 to about 4, an apparatus for imaging an object.

11. As a device for imaging an object in one of a plurality of positions,

A first beam divider arranged to receive light from the object and for dividing the light into a first beam and a second beam, and arranged to receive the second beam when the object is at the farthest position among the plurality of positions, In addition, a first optical branching module including a first imaging module for imaging an object; And

An additional beam divider arranged to receive light from the first beam and for dividing the light into an imaging beam and a continuous beam, and an object disposed to receive the imaging beam when the object is at another position among the plurality of positions Including at least one additional optical branching module comprising an additional imaging module for imaging,

The continuous beam proceeds to one of the next additional optical branching module and a final optical module arranged to receive light from the continuous beam, and the final optical module is a folding mirror, and the object is the closest among the plurality of positions. An apparatus for imaging an object, arranged to receive the second beam when in position and further comprising a final optical imaging module for imaging the object.

It will be apparent to those skilled in the art that the above principle can also be applied to systems that image objects at more than two positions. In addition, although the above description is for an optical system for semiconductor photolithography as an example, it is apparent to those skilled in the art that the disclosed system can be used in other applications where it is required to image an object that may be in any one of a number of locations. something to do.

The present disclosure is made with the aid of functional blocks showing the execution of specified functions and their relationships. The boundaries of these functional blocks have been arbitrarily defined herein for convenience of description. Alternative boundaries can be defined as long as the specified functions and their relationships are properly performed. For example, metrology module functions may be divided among several systems or may be performed at least in part by the entire control system.

The above description includes examples of one or more embodiments. Of course, it is not possible to describe all possible combinations of components or methods for description of the above-mentioned embodiments, but those skilled in the art will appreciate that many additional embodiments and substitutions of various embodiments are possible. Accordingly, the described embodiments are intended to include all such changes, modifications and changes falling within the spirit and scope of the appended claims. In addition, as long as the term "comprises" is used in the detailed description or claims, such terms ..... Also, although elements of the described aspects and/or embodiments may be described or claimed in the singular form, Unless explicitly stated to be limited to the singular, the plural is also considered. Additionally, unless otherwise stated, all or part of any aspect and/or embodiment may be used in conjunction with all or part of other aspects and/or embodiments.

Claims (11)

An apparatus for imaging an object in one of a first position and a second position,
A beam divider disposed to receive light from the object and for dividing the light into a first beam and a second beam;
A first optical element disposed to receive the first beam;
A device for imaging an object, comprising a device comprising a folding mirror and a second optical element arranged to receive the second beam. The method of claim 1,
An apparatus for imaging an object, further comprising a third optical element optically disposed between the beam splitter and the first optical element, and a fourth optical element optically disposed between the folding mirror and the second optical element. The method of claim 1,
An apparatus for imaging an object, further comprising a third optical element optically disposed between the object and the beam splitter. An apparatus for imaging an object in one of a first position and a second position,
A beam divider disposed to receive light from the object and for dividing the light into a first beam and a second beam traversing the first arm; And
A folding mirror disposed to receive the second beam and reflect the second beam to a second arm,
The first arm includes a first optical element arranged to receive a first beam, and a second optical element arranged to receive a first beam from the first optical element,
The second arm comprises a third optical element arranged to receive a reflected second beam, and a fourth optical element arranged to receive a second beam from the third optical element. An apparatus for imaging an object in one of a first position and a second position,
A first optical element arranged to receive light from the object;
A beam splitter arranged to receive light from the first optical element and for dividing the light into a first beam and a second beam traversing the first arm, a second optical element arranged to receive the first beam Includes -; And
A device for imaging an object, comprising a device comprising a folding mirror and a third optical element arranged to receive the second beam. An apparatus for imaging an object in one of a first position and a second position,
A beam divider arranged to divide the light from the object into a first beam and a second beam;
A first optical system arranged to receive the first beam and image the object when the object is in the first position; And
And a second optical system arranged to receive the second beam and image the object when the object is in a second position. The method of claim 6,
The first optical system comprises a first optical element and a second optical element, and the second optical system comprises a folding mirror, a third optical element and a fourth optical element. The method of claim 6,
Further comprising a first optical element optically disposed between the object and the beam splitter, the first optical system comprising a second optical element, and the second optical system comprising a folding mirror and a third optical element , A device for imaging an object. An apparatus for imaging an object in a first position or a second position,
A beam splitter arranged to divide light traveling from the object to a first optical path into a first beam and a second beam;
A first optical module disposed to receive the first beam and image the object when the object is in the first position; And
And a second optical module arranged to receive the second beam and image the object when the object is in a second position. An apparatus for imaging an object in one of a first position and a second position,
A first optical element arranged to receive light from the object at a first working distance WD1 from the first position and at a second working distance WD2 from the second position; And
A beam splitter arranged to receive light from the first optical element and for dividing the light into a first beam and a second beam traversing the first arm,
The first arm includes a first arm lens group disposed to receive the first beam and having a focal length F1', and the second beam includes a first lens and a first lens separated from each other by a distance d. Traversing a second arm lens group including 2 lenses and having a focal length (F2'), WD1, WD2, F2' and F1' satisfy the following relationship,

Wherein k is a coefficient in the range of about 1 to about 4, an apparatus for imaging an object. As a device for imaging an object at any one of a plurality of positions,
A first beam divider arranged to receive light from the object and for dividing the light into a first beam and a second beam, and arranged to receive the second beam when the object is at the farthest position among the plurality of positions, In addition, a first optical bifurcation module including a first imaging module for imaging an object; And
An additional beam divider arranged to receive light from the first beam and for dividing the light into an imaging beam and a continuous beam, and an object arranged to receive the imaging beam when the object is at another position among the plurality of positions At least one additional optical branching module including an additional imaging module for imaging,
The continuous beam proceeds to one of the next additional optical branching module and a final optical module arranged to receive light from the continuous beam, and the final optical module is a folding mirror, and the object is the closest among the plurality of positions. An apparatus for imaging an object, arranged to receive the second beam when in position and further comprising a final optical imaging module for imaging the object.

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