Reticle conditioning nozzle

Abstract

A reticle conditioning nozzle configured to supply conditioning fluid to a sub-volume of a reticle handling module includes an inlet end, configured to receive conditioning fluid from a conditioning fluid source, an outlet end, configured to distribute the conditioning fluid into the sub-volume of the reticle handling module, wherein the outlet end is configured to deliver two separated fluid flows, a first fluid flow across a top surface of a reticle in the reticle handling module, and a second fluid flow across a bottom surface of the reticle, and a transitional section, comprising vanes disposed between the inlet end and the outlet end, the transitional section being configured to vary a flow of the conditioning fluid across a width of the outlet end such that a temperature gradient across a surface of the reticle is reduced.

Description

CONDITIONING NOZZLECROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority of US application 63 / 537,134 which was filed on 7 September 2023 and which is incorporated herein in its entirety by reference.FIELD

[0002] The present description relates to systems and methods for providing a conditioning flow of fluid to a substrate, and more particularly to such systems and devices for use in conditioning systems in a reticle handling subsystem of a photolithography system.BACKGROUND

[0003] A lithographic apparatus is a machine that applies a desired pattern onto a substrate, usually onto a target portion of the substrate. A lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs). In that instance, a patterning device, which is alternatively referred to as a mask or a reticle, may be used to generate a circuit pattern to be formed on an individual layer of the IC. This pattern can be transferred onto a target portion (e.g., including part of, one, or several dies) on a substrate (e.g., a silicon wafer). Transfer of the pattern is typically via imaging onto a layer of 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. Known lithographic apparatus include so-called steppers, in which each target portion is irradiated by exposing an entire pattern onto the target portion at one time, and so-called scanners, in which each target portion is irradiated by scanning the pattern through a radiation beam in a given direction (the “scanning”- direction) while synchronously scanning the substrate parallel or anti parallel to this direction. It is also possible to transfer the pattern from the patterning device to the substrate by imprinting the pattern onto the substrate.SUMMARY

[0004] A reticle conditioning nozzle configured to supply conditioning fluid to a sub-volume of a reticle handling module includes an inlet end, configured to receive conditioning fluid from a conditioning fluid source, an outlet end, configured to distribute the conditioning fluid into the subvolume of the reticle handling module, wherein the outlet end is configured to deliver two separated fluid flows, a first fluid flow across a top surface of a reticle in the reticle handling module, and a second fluid flow across a bottom surface of the reticle, and a transitional section, comprising vanes disposed between the inlet end and the outlet end, the transitional section being configured to vary a flow of theconditioning fluid across a width of the outlet end such that a temperature gradient across a surface of the reticle is reduced.

[0005] In an aspect, there is provided a method of manufacturing devices wherein a device pattern is applied to a series of substrates using a lithographic process, the method including conditioning a reticle using a device as described herein.

[0006] In aspect, there is provided a non-transitory computer program product comprising machine -readable instructions configured to cause a processor to cause performance of a method described herein.BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Embodiments will now be described, by way of example only, with reference to the accompanying drawings in which:

[0008] Figure 1 schematically depicts an embodiment of a lithographic apparatus;

[0009] Figure 2 schematically depicts an embodiment of a lithographic cell or cluster;

[0010] Figures 3A and 3B schematically illustrate a reticle handling chamber and turret chamber;

[0011] Figures 4A and 4B schematically illustrate a reticle handling chamber and turret chamber in accordance with an embodiment;

[0012] Figure 5 schematically illustrates a turret chamber in accordance with an embodiment;

[0013] Figures 6A, 6B, and 6C illustrate a nozzle in accordance with an embodiment;

[0014] Figures 7A and 7B schematically illustrate an air volume inside a nozzle in accordance with an embodiment; and

[0015] Figures 8A and 8B illustrate flows within a turret chamber in accordance with an embodiment.DETAILED DESCRIPTION

[0016] Before describing embodiments in detail, it is instructive to present an example environment in which embodiments may be implemented.

[0017] Figure 1 schematically depicts a lithographic apparatus LA. The apparatus comprises: an illumination system (illuminator) IL configured to condition a radiation beam B (e.g. DUV radiation or EUV radiation); a support structure (e.g. a mask table) MT constructed to support a patterning device (e.g. a mask) MA and connected to a first positioner PM configured to accurately position the patterning device in accordance with certain parameters; a substrate table (e.g. a wafer table) WTa constructed to hold a substrate (e.g. a resist-coated wafer) W and connected to a second positioner PW configured to accurately position the substrate in accordance with certain parameters; anda projection system (e.g. a refractive projection lens system) PS configured to project a pattern imparted to the radiation beam B by patterning device MA onto a target portion C (e.g. comprising one or more dies) of the substrate W.

[0018] The illumination system may include various types of optical components, such as refractive, reflective, magnetic, electromagnetic, electrostatic or other types of optical components, or any combination thereof, for directing, shaping, or controlling radiation.

[0019] The patterning device support structure holds the patterning device in a manner that depends on the orientation of the patterning device, the design of the lithographic apparatus, and other conditions, such as for example whether or not the patterning device is held in a vacuum environment. The patterning device support structure can use mechanical, vacuum, electrostatic or other clamping techniques to hold the patterning device. The patterning device support structure may be a frame or a table, for example, which may be fixed or movable as required. The patterning device support structure may ensure that the patterning device is at a desired position, for example with respect to the projection system. Any use of the terms “reticle” or “mask” herein may be considered synonymous with the more general term “patterning device.”

[0020] The term “patterning device” used herein should be broadly interpreted as referring to any device that can be used to impart a radiation beam with a pattern in its cross-section such as to create a pattern in a target portion of the substrate. It should be noted that the pattern imparted to the radiation beam may not exactly correspond to the desired pattern in the target portion of the substrate, for example if the pattern includes phase-shifting features or so called assist features. Generally, the pattern imparted to the radiation beam will correspond to a particular functional layer in a device being created in the target portion, such as an integrated circuit.

[0021] 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, as well as various hybrid mask types. An example of a programmable mirror array employs a matrix arrangement of small mirrors, each of which can be individually tilted so as to reflect an incoming radiation beam in different directions. The tilted mirrors impart a pattern in a radiation beam, which is reflected by the mirror matrix.

[0022] The term “projection system” used herein should be broadly interpreted as encompassing any type of projection system, including refractive, reflective, catadioptric, magnetic, electromagnetic and electrostatic optical systems, or any combination thereof, as appropriate for the exposure radiation being used, or for other factors such as the use of an immersion liquid or the use of a vacuum. Any use of the term “projection lens” herein may be considered as synonymous with the more general term “projection system”.

[0023] As here depicted, the apparatus is of a transmissive type (e.g., employing a transmissivemask). Alternatively, the apparatus may be of a reflective type (e.g., employing a programmable mirror array of a type as referred to above, or employing a reflective mask).

[0024] The lithographic apparatus may be of a type having two (dual stage) or more tables (e.g., two or more substrate table, two or more patterning device support structures, or a substrate table and metrology table). In such “multiple stage” machines the additional tables may be used in parallel, or preparatory steps may be carried out on one or more tables while one or more other tables are being used for exposure.

[0025] The lithographic apparatus may also be of a type wherein at least a portion of the substrate may be covered by a liquid having a relatively high refractive index, e.g., water, so as to fill a space between the projection system and the substrate. An immersion liquid may also be applied to other spaces in the lithographic apparatus, for example, between the mask and the projection system. Immersion techniques are well known in the art for increasing the numerical aperture of projection systems. The term “immersion” as used herein does not mean that a structure, such as a substrate, must be submerged in liquid, but rather only means that liquid is located between the projection system and the substrate during exposure.

[0026] Referring to Figure 1 , the illuminator IL receives a radiation beam from a radiation source SO. The source and the lithographic apparatus may be separate entities, for example when the source is an excimer laser. In such cases, the source is not considered to form part of the lithographic apparatus and the radiation beam is passed from the source SO to the illuminator IL with the aid of a beam delivery system BD including, for example, suitable directing mirrors and / or a beam expander. In other cases the source may be an integral part of the lithographic apparatus, for example when the source is a mercury lamp. The source SO and the illuminator IL, together with the beam delivery system BD if required, may be referred to as a radiation system.

[0027] The illuminator IL may include an adjuster AD for adjusting the angular intensity distribution of the radiation beam. Generally, at least the outer and / or inner radial extent (commonly referred to as o-outer and o-inner, respectively) of the intensity distribution in a pupil plane of the illuminator can be adjusted. In addition, 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, to have a desired uniformity and intensity distribution in its cross section.

[0028] The radiation beam B is incident on the patterning device (e.g., mask) MA, which is held on the patterning device support (e.g., mask table MT), and is patterned by the patterning device. Having traversed the patterning device (e.g., mask) MA, the radiation beam B passes through the projection system PS, which focuses the beam onto a target portion C of the substrate W. With the aid of the second positioner PW and position sensor IF (e.g., an interferometric device, linear encoder, 2-D encoder or capacitive sensor), the substrate table WTa can be moved accurately, e.g., so as to position different target portions C in the path of the radiation beam B. Similarly, the first positioner PM andanother position sensor (which is not explicitly depicted in Figure 1) can be used to accurately position the patterning device (e.g., mask) MA with respect to the path of the radiation beam B, e.g., after mechanical retrieval from a mask library, or during a scan. In general, movement of the patterning device support (e.g., mask table) MT may be realized with the aid of a long-stroke module (coarse positioning) and a short-stroke module (fine positioning), which form part of the first positioner PM. Similarly, movement of the substrate table WTa may be realized using a long-stroke module and a short-stroke module, which form part of the second positioner PW. In the case of a stepper (as opposed to a scanner) the patterning device support (e.g., mask table) MT may be connected to a short-stroke actuator only, or may be fixed.

[0029] Patterning device (e.g., mask) MA and substrate W may be aligned using mask alignment marks Ml, M2 and substrate alignment marks Pl, P2. Although the substrate alignment marks as illustrated occupy dedicated target portions, they may be located in spaces between target portions (these are known as scribe-lane alignment marks). Similarly, in situations in which more than one die is provided on the patterning device (e.g., mask) MA, the mask alignment marks may be located between the dies. Small alignment markers may also be included within dies, in amongst the device features, in which case it is desirable that the markers be as small as possible and not require any different imaging or process conditions than adjacent features. The alignment system, which detects the alignment markers is described further below.

[0030] The depicted apparatus could be used in at least one of the following modes:In step mode, the patterning device support (e.g., mask table) MT and the substrate table WTa are kept essentially stationary, while an entire pattern imparted to the radiation beam is projected onto a target portion C at one time (i.e., a single static exposure). The substrate table WTa is then shifted in the X and / or Y direction so that a different target portion C can be exposed. In step mode, the maximum size of the exposure field limits the size of the target portion C imaged in a single static exposure.In scan mode, the patterning device support (e.g., mask table) MT and the substrate table WTa are scanned synchronously while a pattern imparted to the radiation beam is projected onto a target portion C (i.e., a single dynamic exposure). The velocity and direction of the substrate table WTa relative to the patterning device support (e.g., mask table) MT may be determined by the (de-)magnification and image reversal characteristics of the projection system PS. In scan mode, the maximum size of the exposure field limits the width (in the non-scanning direction) of the target portion in a single dynamic exposure, whereas the length of the scanning motion determines the height (in the scanning direction) of the target portion.In another mode, the patterning device support (e.g., mask table) MT is kept essentially stationary holding a programmable patterning device, and the substrate table WTa is moved or scanned while a pattern imparted to the radiation beam is projected onto a target portion C. In this mode, generally a pulsed radiation source is employed and the programmable patterning device is updated asrequired after each movement of the substrate table WTa or in between successive radiation pulses during a scan. This mode of operation can be readily applied to maskless lithography that utilizes programmable patterning device, such as a programmable mirror array of a type as referred to above.

[0031] Combinations and / or variations on the above described modes of use or entirely different modes of use may also be employed.

[0032] Lithographic apparatus LA may be of a so-called dual stage type which has two tables WTa, WTb (e.g., two substrate tables) and two stations - an exposure station and a measurement station - between which the tables can be exchanged. For example, while a substrate on one table is being exposed at the exposure station, another substrate can be loaded onto the other substrate table at the measurement station and various preparatory steps carried out. The preparatory steps may include mapping the surface control of the substrate using a level sensor LS and measuring the position of alignment markers on the substrate using an alignment sensor AS, both sensors being supported by a reference frame RF. If the position sensor IF is not capable of measuring the position of a table while it is at the measurement station as well as at the exposure station, a second position sensor may be provided to enable the positions of the table to be tracked at both stations. As another example, while a substrate on one table is being exposed at the exposure station, another table without a substrate waits at the measurement station (where optionally measurement activity may occur). This other table has one or more measurement devices and may optionally have other tools (e.g., cleaning apparatus). When the substrate has completed exposure, the table without a substrate moves to the exposure station to perform, e.g., measurements and the table with the substrate moves to a location (e.g., the measurement station) where the substrate is unloaded and another substrate is load. These multi-table arrangements enable a substantial increase in the throughput of the apparatus.

[0033] As shown in Figure 2, the lithographic apparatus LA may form part of a lithographic cell LC, also sometimes referred to as a lithocell or lithocluster, which also includes apparatus to perform one or more pre- and post-exposure processes on a substrate. Conventionally these include one or more spin coaters SC to deposit a resist layer, one or more developers DE to develop exposed resist, one or more chill plates CH and one or more bake plates BK. A substrate handler, or robot, RO picks up a substrate from input / output ports I / Ol , I / O2, moves it between the different process devices and delivers it to the loading bay LB of the lithographic apparatus. These devices, which are often collectively referred to as the track, are under the control of a track control unit TCU which is itself controlled by the supervisory control system SCS, which also controls the lithographic apparatus via lithographic control unit LACU. Thus, the different apparatus may be operated to maximize throughput and processing efficiency.

[0034] In order that the substrate that is exposed by the lithographic apparatus is exposed correctly and consistently, it is desirable to inspect an exposed substrate to measure one or more properties such as overlay error between subsequent layers, line thickness, critical dimension (CD), etc. If an error isdetected, an adjustment may be made to an exposure of one or more subsequent substrates. This may particularly useful, for example, if the inspection can be done soon and fast enough that another substrate of the same batch is still to be exposed. Also, an already exposed substrate may be stripped and reworked (to improve yield) or discarded, thereby avoiding performing an exposure on a substrate that is known to be faulty. In a case where only some target portions of a substrate are faulty, a further exposure may be performed only on those target portions which are good. Another possibility is to adapt a setting of a subsequent process step to compensate for the error, e.g. the time of a trim etch step can be adjusted to compensate for substrate-to-substrate CD variation resulting from the lithographic process step.

[0035] An inspection apparatus is used to determine one or more properties of a substrate, and in particular, how one or more properties of different substrates or different layers of the same substrate vary from layer to layer and / or across a substrate. The inspection apparatus may be integrated into the lithographic apparatus LA or the lithocell LC or may be a stand-alone device. To enable most rapid measurements, it is desirable that the inspection apparatus measure one or more properties in the exposed resist layer immediately after the exposure. However, the latent image in the resist has a very low contrast - there is only a very small difference in refractive index between the part of the resist which has been exposed to radiation and that which has not - and not all inspection apparatus have sufficient sensitivity to make useful measurements of the latent image. Therefore measurements may be taken after the post-exposure bake step (PEB) which is customarily the first step carried out on an exposed substrate and increases the contrast between exposed and unexposed parts of the resist. At this stage, the image in the resist may be referred to as semi-latent. It is also possible to make measurements of the developed resist image - at which point either the exposed or unexposed parts of the resist have been removed - or after a pattern transfer step such as etching. The latter possibility limits the possibility for rework of a faulty substrate but may still provide useful information, e.g. for the purpose of process control.

[0036] It is useful to have available multiple patterning devices available for imaging. One application of multiple patterning devices is, for example, in double exposure imaging. In general, double patterning is an exposure method that involves splitting (i.e., dividing or separating) a dense circuit pattern into two separate, less-dense patterns. The simplified patterns are then printed separately on a target wafer using two separate masks (where one of the masks is utilized to image one of the less-dense patterns, and the other mask is utilized to image the other less-dense patterns). The second pattern may be printed in between the lines of the first pattern such that the imaged wafer has, for example, a feature pitch which is half that found on either of the two masks. This technique effectively lowers the complexity of the lithography process, improving the achievable resolution and enabling the printing of far smaller features than would otherwise be possible.

[0037] Patterning device exchange may be performed using a patterning device handling systemincluding a patterning device handling robot and a turret in order to keep the exchange time small. The turret can hold multiple patterning devices in various different holding positions, and can be rotated around its vertical axis so that one of the holding positions can be turned to a position wherein the turret can exchange a patterning device with the patterning device support. In another position, a patterning device in the other of the two holding positions can be exchanged with the patterning device support.

[0038] The robot cooperates with a loading station and the turret to exchange patterning devices between storage positions and the patterning device support. An exchange system of this type is described in U.S. Pat. No. 7136147, incorporated herein by reference in its entirety.

[0039] Figures 3A and 3B schematically illustrate a side and top plan view respectively of a reticle handling system 300. A reticle handling chamber 302 is interconnected with a turret chamber 304. Inside the turret chamber 304 is the turret 306, of which only the gripper element is illustrated in the figures. The turret 306 holds a reticle 308. Airflow through the combined system is represented by the arrows 310 and 312. Within the turret chamber 304 generally there are additional structures such as electrical components 314 (LEDs, amplifiers, for example) and mechanical components 316 (gripper connection boxes, for example). These structures can both affect airflow through turret chamber 304, and can produce heat, both of which affect the temperature within the chamber.

[0040] As may be seen in Figure 3B, the opening on the mechanical component 316 side (reticle stage side) can cause airflow to divert the flow 318 away before reaching the reticle surface. In the system as illustrated, in addition to airflow from the handling chamber 302, there is provided a clean air nozzle 320 mounted on the side of the turret, which may blow clean air, for example, at a rate of about 300 NL / min at a pressure of about 400 Pa and a controlled temperature of about 22C. Alternately, the clean air nozzle may provide clean air at a rate of 400 NL / min at a pressure of about 200 Pa. As will be appreciated, the specific flow rate and pressure may be selected for the particular geometry of the system.

[0041] Because of the presence of the electrical components 314 and the mechanical components 316 and 218 (and more generally, any such components present in the chamber) a uniform airflow from the clean air nozzle 320 will not result in the elimination of non-uniformity of the temperatures in the turret chamber 304 and more importantly on the surface of the reticle 308. That is, where hot spots exist near the heat generating electrical components 314, and consequently on the surface of the reticle 308 near the heat sources. The cooling air from the clean air nozzle 320 will cool both the hot spots on the surface of the reticle 308 and the other portions of the turret chamber 304 such that the hot spots remain warmer than the other portions.

[0042] Figures 4A and 4B schematically illustrate a side and top view respectively of turret system 400 of a novel reticle handling system in accordance with an embodiment. Similarly to the arrangement of Figures 3 A and 3B, a reticle handling chamber 402 is interconnected with a turret chamber 404.Inside the turret chamber 404 is the turret 406, of which only the gripper element is illustrated in the figures. The turret 406 holds a reticle 408. Airflow through the combined system is represented by the arrows 410. Within the turret chamber 404 generally there are additional structures such as electrical components 414 (LEDs, amplifiers, for example) and mechanical components 416 (gripper connection boxes, for example). These structures can both affect airflow through turret chamber 404, and can produce heat, both of which affect the temperature within the chamber. A clean air nozzle 422 may be optionally mounted on the side of the turret, which may blow clean air, for example, at a rate of about 300 NL / min at a pressure of about 400 Pa and a controlled temperature of about 22C. Optionally, one or more of the electrical components 414 may be relocated to an edge of the turret chamber, or even outside of the turret chamber to reduce or eliminate heating effects associated with it.

[0043] In addition, a nozzle 422 is located in the turret chamber 404. This nozzle 422 is configured to provide temperature controlling fluid flow, for example, clean dry air or extra clean dry air (XDCA) to the turret chamber 404. Extra clean dry air may be useful in that compared with clean air, there are fewer contaminants, including fewer sulfur compounds, and lower humidity. This can help to reduce issues like hazing on surfaces of the reticle, its pellicle, where present, and other components in the chamber. In particular, SO2 in the presence of H2O and light radiation can develop sulfuric acid, which in turn can react with nitrogen compounds (e.g., NH3) to produce ammonium sulfate particles (NtL SCL, which can diffuse into various parts of the photolithography tool, and produce hazing on surfaces of optical components of the tool, including on the surfaces of the reticle itself. The nozzle 422 may be configured to provide the fluid flow at a rate that allows for laminar flow or substantially laminar flow within the turret chamber 404.

[0044] Because of the non-uniformity of the space within the turret chamber 404, the inventors have determined that a non-uniform flow of temperature controlling fluid is useful. In view of this, the nozzle 422 may be configured to provide a non-uniform fluid flow, for example more volume of XDCA may be directed near the heat producing electrical components 414, or similarly, where mechanical components 416 are present to deflect fluid flow, the nozzle may provide a larger volume of XDCA near a central portion of the deflecting body, and a smaller volume near its edges.

[0045] Figure 5 shows an isometric view of the turret chamber 404 including the relative positions of the nozzle 422, and some of the electrical components 414 and mechanical components 416. As may be seen, an inlet end 423 of the nozzle 422 is located at a side of the chamber and is configured to receive conditioning fluid from a conditioning fluid source (not shown). An outlet end 424 of the nozzle 422 is positioned within the chamber, upstream of the turret 406 and is configured to distribute the conditioning fluid into a sub-volume of the turret chamber 404 of the reticle handling module. In a particular embodiment, the inlet end may be a round 11mm diameter inlet and the outlet end may be a 160mm x 17.5mm rectangular outlet. The outlet end may further be configured such that it acts as a closed profile air blade.

[0046] Figures 6A, 6B, and 6C illustrate an embodiment in accordance with an aspect of the invention. In particular, Figure 6A shows a sectional view of the nozzle 422, and shows that the outlet end 424 may be split into two vertically separated components, 424a and 424b and three horizontal sections 426a, 426b, 426c. This vertical separation can allow for separated air flows around the reticle 408 such that there is a first fluid flow across a top surface of the reticle and a second fluid flow across a bottom surface of the reticle as best seen in Figure 8A, described below. Additionally, a width of the outlet end 424 of the nozzle 422 can be selected to ensure that side streams flow along side edges of the reticle, as seen best in Figure 8B, described below. The inlet end 423 may also include threading to allow connection to a supply line via a connector 428.

[0047] Figure 7 A and Figure 7B show an embodiment of an air volume inside a nozzle 722 in which the structure of the nozzle has been designed to optimize the non-uniformity of the fluid flow from its outlet end in order to reduce temperature gradients present in the turret chamber 404 and in particular the surface of the reticle 308. While in principle it would be preferred to ensure that all temperature gradients are eliminated entirely, as a practical matter, elimination is not achievable, such that a reduction is a desirable and useful outcome. To the extent possible, temperature differences of less than about 0.2C on the surface of the reticle 308 are tolerable, and reduction to that amount may be considered to be elimination or reduction of the temperature gradients. By way of example, where the clean air shower shown in Figures 3A and 3B might produce a temperature range of about 22.25C to 22.42C within a chamber having a target temperature around 22C, the inventive nozzle may result in a range of about 22.17C to 22.29C on the surface of the reticle 308 in a similar chamber while being considered to be an effective reduction in temperature gradient.

[0048] In order to achieve this non-uniformity of fluid flow, there is a transitional section 726 between the inlet end 723 and the outlet end 724 of the nozzle 722 that is configured to vary a flow of the conditioning fluid across the width of the outlet end. As in the embodiment shown above in Figure 6A, the outlet end may also include a vertical non-uniformity in addition to the width wise variation of fluid flow.

[0049] Figure 8A is a side view of a turret chamber 804 in accordance with an embodiment. In this embodiment, the turret chamber 804 includes the turret 806, a reticle 808, and the nozzle 822. The nozzle 822 is split vertically into upper outlet 823a and lower outlet 823b. These vertically separated outlets produce upper fluid flow 824a and lower fluid flow 824b, respectively. The upper fluid flow 824a flows across a top surface of the reticle and the lower fluid flow 824b flows across a bottom surface of the reticle. The grey scale of Figure 8A illustrates static temperature.

[0050] Figure 8B is a top plan view of the turret chamber 804, illustrating the variation in flow rates across a width of the outlet 822. As schematically illustrated, the fluid flow 824 is higher at a right side than at a left side of the outlet 823. Furthermore, flows 824c and 824d flow along edges of the reticle 808 in the form of side streams. These side streams may provide, in addition to thetemperature control function, the function of reducing diffusion of air into the pellicle / reticle system.

[0051] The transitional section 726 may include, for example, partitions or vanes 728 that cause changes in airflow rates within the transitional section. In the embodiment shown in Figures 7A and 7B, two vanes 728 divide the transitional section into three separate passages 730a, 730b, 730c.

[0052] Embodiments of the nozzle 422, 722, 822 may vary. For example, they may include blade outlets as generally illustrated herein, or an array of needle nozzles in place of the blade outlets. The nozzle may be disposed at an angle of attack (AOA) relative to a surface of the reticle, and the inventors have determined that an AOA between about 10° and about 20° produces useful results. The vanes or openings in the transitional area may be selected to reduce or eliminate internal regions where vortexes form, as such eddying can cause undesirable pressure drop and / or flow vibrations. There may be two vanes as illustrated in Figures 7A and 7B, or more or fewer vanes, though the inventors have found good performance using three. Additional side extensions may be included, which are configured to supply the fluid along sides of the reticle. More particularly, where the reticle and pellicle are arranged with a pressure relief opening on a sidewall thereof, the side extensions may be arranged to produce a flow that impinges on the pressure relief opening(s) to reduce flow of material other than the XCDA into that opening.

[0053] While this disclosure has been primarily concerned with a conditioning system for a reticle handling device, the principles may be applied to other temperature controlled subsystems within a lithographic apparatus, an inspection apparatus, or similar systems.

[0054] Eikewise, while the context of the systems and methods described herein has been photolithography, other high precision, high speed tools may make use of similar approaches, including, but not limited to inspection tools, e-beam stages, and other types of tools altogether outside the realm of integrated circuit manufacturing.

[0055] Various embodiments of the present apparatuses, systems and methods are disclosed in the subsequent list of numbered clauses:1. A reticle conditioning nozzle configured to supply conditioning fluid to a sub-volume of a reticle handling module, comprising: an inlet end, configured to receive conditioning fluid from a conditioning fluid source; an outlet end, configured to distribute the conditioning fluid into the sub-volume of the reticle handling module, wherein the outlet end is configured to deliver two separated fluid flows, a first fluid flow across a top surface of a reticle in the reticle handling module, and a second fluid flow across a bottom surface of the reticle; and a transitional section, comprising vanes disposed between the inlet end and the outlet end, the transitional section being configured to vary a flow of the conditioning fluid across a width of the outlet end such that a temperature gradient across a surface of the reticle is reduced.2. A reticle conditioning nozzle as in clause 1, wherein the outlet end is further configured todeliver side streams to respective side edges of the reticle.3. A reticle conditioning nozzle as in clause 1, wherein the transitional section comprises a partition disposed horizontally to divide the conditioning fluid across the perimeter of the rectangular outlet of the nozzle.4. A reticle conditioning nozzle as in clause 1, wherein the transitional section comprises two vanes splitting the transitional section into three separate passages arrayed along a width of the transitional section.5. A reticle conditioning nozzle as in clause 4, wherein the vanes are configured such that the three separate passages rejoin each other at the outlet end.6. A reticle conditioning nozzle as in clause 4, wherein the vanes each have a concave-convex structure to optimize the flow in different zones.7. A reticle conditioning nozzle as in clause 6, wherein a concave face of the first vane differs in shape from a concave face of the second vane, such that the flow across the width of the outlet end is varied.8. A reticle conditioning nozzle as in clause 6 or 7, wherein a convex face of the first vane differs in shape from a convex face of the second vane, such that the flow across the width of the outlet end is varied.9. A reticle conditioning nozzle as in clause 8, wherein each convex face is configured to reduce an amount of internal vortices and induced flow vibrations.10. A reticle conditioning nozzle as in any of clauses 1-9 wherein the conditioning fluid is extreme clean dry air, having an SO2 content of O.Olppt or less and a water content of less than 300ppt.11. A reticle conditioning nozzle as in any of clauses 1-10, wherein the conditioning fluid is supplied at a rate of about 100 Nl / minute.12. A reticle conditioning nozzle as in any of clauses 1-11, wherein the nozzle is configured such that, in use, different flow rates at different positions along the outlet end produce a uniform temperature profile across the surfaces of the reticle.13. A reticle conditioning nozzle as in any of clauses 1-12 wherein the conditioning fluid is delivered to the surfaces of the reticle as a laminar flow.

[0056] The terms “optimize”, “optimizing” and “optimization” as used herein mean adjusting a lithographic process parameter such that results and / or processes of lithography have a more desirable characteristic, such as higher accuracy of projection of a design layout on a substrate, a larger process window, etc.

[0057] An embodiment of the invention may take the form of a computer program containing one or more sequences of machine-readable instructions describing a method as disclosed herein, or a data storage medium (e.g. semiconductor memory, magnetic or optical disk) having such a computer program stored therein. Further, the machine readable instruction may be embodied in two or more computer programs. The two or more computer programs may be stored on one or more differentmemories and / or data storage media.

[0058] This computer program may be included, for example, with or within the imaging apparatus of Figure 1 and / or with or within the control unit LACU of Figure 2. Where an existing apparatus, for example of the type shown in Figures 1 and 2, is already in production and / or in use, an embodiment can be implemented by the provision of updated computer program products for causing a processor of the apparatus to perform a method as described herein.

[0059] Any controllers described herein may each or in combination be operable when the one or more computer programs are read by one or more computer processors located within at least one component of the lithographic apparatus. The controllers may each or in combination have any suitable configuration for receiving, processing, and sending signals. One or more processors are configured to communicate with the at least one of the controllers. For example, each controller may include one or more processors for executing the computer programs that include machine-readable instructions for the methods described above. The controllers may include data storage medium for storing such computer programs, and / or hardware to receive such medium. So the controller(s) may operate according the machine readable instructions of one or more computer programs.

[0060] Although specific reference may have been made above to the use of embodiments in the context of lithography using radiation, it will be appreciated that an embodiment of the invention may be used in other applications, for example imprint lithography, and where the context allows, is not limited to lithography using radiation. In imprint lithography, a topography in a patterning device defines the pattern created on a substrate. The topography of the patterning device may be pressed into a layer of resist supplied to the substrate whereupon the resist is cured by applying electromagnetic radiation, heat, pressure or a combination thereof. The patterning device is moved out of the resist leaving a pattern in it after the resist is cured.

[0061] Further, although specific reference may be made in this text to the use of lithographic apparatus in the manufacture of ICs, it should be understood that the lithographic apparatus described herein may have other applications, such as the manufacture of integrated optical systems, guidance and detection patterns for magnetic domain memories, flat-panel displays, liquid-crystal displays (LCDs), thin film magnetic heads, etc. The skilled artisan will appreciate that, in the context of such alternative applications, any use of the terms “wafer” or “die” herein may be considered as synonymous with the more general terms “substrate” or “target portion", respectively. The substrate referred to herein may be processed, before or after exposure, in for example a track (a tool that typically applies a layer of resist to a substrate and develops the exposed resist), a metrology tool and / or an inspection tool. Where applicable, the disclosure herein may be applied to such and other substrate processing tools. Further, the substrate may be processed more than once, for example in order to create a multi-layer IC, so that the term substrate used herein may also refer to a substrate that already contains multiple processed layers.

[0062] The patterning device described herein may be referred to as a lithographic patterning device. Thus, the term “lithographic patterning device” may be interpreted as meaning a patterning device which is suitable for use in a lithographic apparatus.

[0063] The terms “radiation” and “beam” used herein encompass all types of electromagnetic radiation, including ultraviolet (UV) radiation (e.g. having a wavelength of or about 365, 355, 248, 193, 157 or 126 nm) and extreme ultra-violet (EUV) radiation (e.g. having a wavelength in the range of 5- 20 nm), as well as particle beams, such as ion beams or electron beams.

[0064] The term “lens”, where the context allows, may refer to any one or combination of various types of optical components, including refractive, reflective, magnetic, electromagnetic and electrostatic optical components.

[0065] The embodiment(s) described, and references in the specification to an “embodiment”, “example,” etc., indicate that the embodiment(s) described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is understood that it is within the knowledge of one skilled in the art to effect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

[0066] The descriptions above are intended to be illustrative, not limiting. Thus, it will be apparent to one skilled in the art that modifications may be made to the invention as described without departing from the scope of the claims set out below. For example, one or more aspects of one or more embodiments may be combined with or substituted for one or more aspects of one or more other embodiments as appropriate. Therefore, such adaptations and modifications are intended to be within the meaning and range of equivalents of the disclosed embodiments, based on the teaching and guidance presented herein. It is to be understood that the phraseology or terminology herein is for the purpose of description by example, and not of limitation, such that the terminology or phraseology of the present specification is to be interpreted by the skilled artisan in light of the teachings and guidance. The breadth and scope of the invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.

Claims

CLAIMS1. A reticle conditioning nozzle configured to supply conditioning fluid to a sub-volume of a reticle handling module, comprising: an inlet end, configured to receive conditioning fluid from a conditioning fluid source; an outlet end, configured to distribute the conditioning fluid into the sub-volume of the reticle handling module, wherein the outlet end is configured to deliver two separated fluid flows, a first fluid flow across a top surface of a reticle in the reticle handling module, and a second fluid flow across a bottom surface of the reticle; and a transitional section, comprising vanes disposed between the inlet end and the outlet end, the transitional section being configured to vary a flow of the conditioning fluid across a width of the outlet end such that a temperature gradient across a surface of the reticle is reduced.

2. A reticle conditioning nozzle as in claim 1, wherein the outlet end is further configured to deliver side streams to respective side edges of the reticle.

3. A reticle conditioning nozzle as in claim 1 , wherein the transitional section comprises a partition disposed horizontally to divide the conditioning fluid across the perimeter of the rectangular outlet of the nozzle.

4. A reticle conditioning nozzle as in claim 1 , wherein the transitional section comprises two vanes splitting the transitional section into three separate passages arrayed along a width of the transitional section.

5. A reticle conditioning nozzle as in claim 4, wherein the vanes are configured such that the three separate passages rejoin each other at the outlet end.

6. A reticle conditioning nozzle as in claim 4, wherein the vanes each have a concave-convex structure to optimize the flow in different zones.

7. A reticle conditioning nozzle as in claim 6, wherein a concave face of the first vane differs in shape from a concave face of the second vane, such that the flow across the width of the outlet end is varied.

8. A reticle conditioning nozzle as in claim 6 or 7, wherein a convex face of the first vane differs in shape from a convex face of the second vane, such that the flow across the width of the outlet end is varied.

9. A reticle conditioning nozzle as in claim 8, wherein each convex face is configured to reduce an amount of internal vortices and induced flow vibrations.

10. A reticle conditioning nozzle as in any of claims 1-9 wherein the conditioning fluid is extreme clean dry air, having an SO2 content of O.Olppt or less and a water content of less than 300ppt.

11. A reticle conditioning nozzle as in any of claims 1-10, wherein the conditioning fluid is supplied at a rate of about 100 Nl / minute.

12. A reticle conditioning nozzle as in any of claims 1-11, wherein the nozzle is configured such that, in use, different flow rates at different positions along the outlet end produce a uniform temperature profile across the surfaces of the reticle.

13. A reticle conditioning nozzle as in any of claims 1-12 wherein the conditioning fluid is delivered to the surfaces of the reticle as a laminar flow.

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