Track interface and substrate processing apparatus

Abstract

A track interface for exchanging substrates between a track and a processing unit of a substrate handling apparatus is disclosed, comprising: first and second transfer units configured to transfer a substrate along respective first and second loading transfer paths from the track via one or more substrate track receiving stations to the processing unit and to transfer a substrate along respective first and second unloading transfer paths from the processing unit via one or more substrate track discharge stations to the track, wherein each of the one or more substrate track receiving stations is arranged to receive a substrate from the track and wherein each of the one or more substrate track discharge stations is arranged to discharge a substrate to the track, and wherein the first loading and unloading transfer paths are separated from the second loading and unloading transfer paths.

Description

TRACK INTERFACE AND SUBSTRATE PROCESSING APPARATUSCROSS-REFERENCE TO RELATED APPLICATION

[0001] The application claims priority of EP application 23185288.0 which was filed on 13 July, 2023 and which is incorporated herein in its entirety by reference.FIELD

[0002] The present invention relates to a track interface and a substrate processing apparatus.BACKGROUND

[0003] A lithographic apparatus is a machine constructed to apply a desired pattern onto a substrate. A lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs). A lithographic apparatus may, for example, project a pattern (also often referred to as “design layout” or “design”) of a patterning device (e.g., a mask) onto a layer of radiation-sensitive material (resist) provided on a substrate (e.g., a wafer).

[0004] As semiconductor manufacturing processes continue to advance, the dimensions of circuit elements have continually been reduced while the amount of functional elements, such as transistors, per device has been steadily increasing over decades, following a trend commonly referred to as ‘Moore’s law’. To keep up with Moore’s law the semiconductor industry is chasing technologies that enable to create increasingly smaller features. To project a pattern on a substrate a lithographic apparatus may use electromagnetic radiation. The wavelength of this radiation determines the minimum size of features which are patterned on the substrate. Typical wavelengths currently in use are 365 nm (i-line), 248 nm, 193 nm and 13.5 nm. A lithographic apparatus, which uses extreme ultraviolet (EUV) radiation, having a wavelength within a range of 4 nm to 20 nm, for example 6.7 nm or 13.5 nm, may be used to form smaller features on a substrate than a lithographic apparatus which uses, for example, radiation with a wavelength of 193 nm.

[0005] The substrate being processed in the lithographic apparatus may be supported by a movable substrate support. Generally, it desirable to process subsequently multiple substrates in a lithographic apparatus. To transport multiple substrates between the lithographic apparatus and other substrate handling devices and / or storage devices a track may be provided. The track may supply substrates to be processed to the lithographic apparatus and transport substrates that have been processed in the lithographic apparatus away from the lithographic apparatus.

[0006] In an embodiment, a track interface may be provided between the track and the movable substrate support to transfer the substrate from the track to the substrate support and from the substrate support to the track.

[0007] US 7,345,736 B2 discloses, in the embodiment shown in Figure 7, a track interface to transfer substrates between a track and a processing unit, e.g. a substrate support, for exposure in alithography machine. The track interface comprises a load robot and an unload robot for loading and unloading wafers between the wafer handler track interface and substrate support.

[0008] A substrate may be loaded from the track into a substrate track receiving station. The unload robot transfers the substrate form the substrate track receiving station to a conditioning station where the temperature of the substrate is conditioned. After conditioning, the load robot may load the substrate on the substrate support for processing of the substrate. When processing of the substrate is finished the unloading robot may unload the substrate from the substrate support to a substrate track discharge station which is arranged below the substrate track receiving station. This track interface provides a relatively efficient way of loading substrates on and unloading of substrates from the substrate support of a lithographic apparatus.

[0009] With increasing demand on throughput of substrates in a lithographic apparatus, there is a need to increase capacity of a track interface for a lithographic apparatus. Due to its configuration, the possibility to increase capacity to handle substrate substrates of the known track interface is limited.

[0010] At the same time, there is no or little extra space available for providing the track interface in the known configuration of a lithographic apparatus.SUMMARY

[0011] It is an object of the invention to provide a track interface for exchanging substrates between a track and a processing unit of a substrate handling apparatus that facilitates increased capacity of the track interface to transfer substrates between a track and a processing unit. It is a further object of the invention to provide a track interface with increased capacity within the same dimensions as prior art track interfaces.

[0012] According to an aspect of the invention, there is provided a track interface for exchanging substrates between a track and a processing unit of a substrate handling apparatus, for example a lithographic apparatus, the track interface comprising: a first transfer unit configured to transfer a substrate along a first loading transfer path from one or more substrate track receiving stations to the processing unit and to transfer a substrate along a first unloading transfer path from the processing unit to one or more substrate track discharge stations, and a second transfer unit configured to transfer a substrate along a second loading transfer path from the one or more substrate track receiving stations to the processing unit and to transfer a substrate along a second unloading transfer path from the processing unit to the one or more substrate track discharge stations, wherein each of the one or more substrate track receiving stations is arranged to receive a substrate from the track and wherein each of the one or more substrate track discharge stations is arranged to discharge a substrate to the track,wherein the first loading and unloading transfer paths are separated from the second loading and unloading transfer paths.

[0013] According to an aspect of the invention, there is provided a substrate processing apparatus, comprising: a processing unit configured to perform a process involving substrates, the processing unit comprising at least one movable substrate support configured to hold a substrate; and the track interface of any of the claims 1-13 to load the substrate from the track on the at least one substrate support and / or to unload the substrate from the at least one substrate support to the track..BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings, in which:Figure 1 depicts a schematic overview of a lithographic apparatus;Figure 2 depicts a detailed view of a part of the lithographic apparatus of Figure 1 ;Figure 3 schematically depicts a position control system;Figure 4 schematically depicts an embodiment of a track interface according to the invention;Figure 5 schematically depicts a side view of the substrate track receiving stations and substrate track discharge stations of the track interface of Figure 4; andFigure 6 schematically depicts the track interface of Figure 4 in a second configuration;Figure 7 schematically depicts the track interface of Figure 4 in a third configuration; and Figure 8 schematically depicts an alternative embodiment of a track interface according to the invention.DETAILED DESCRIPTION

[0015] In the present document, the terms “radiation” and “beam” are used to encompass all types of electromagnetic radiation, including ultraviolet radiation (e.g. with a wavelength of 365, 248, 193, 157 or 126 nm) and EUV (extreme ultra-violet radiation, e.g. having a wavelength in the range of about 5-100 nm).

[0016] The term “reticle”, “mask” or “patterning device” as employed in this text may be broadly interpreted as referring to a generic patterning device that can be used to endow an incoming radiation beam with a patterned cross-section, corresponding to a pattern that is to be created in a target portion of the substrate. The term “light valve” can also be used in this context. Besides the classic mask (transmissive or reflective, binary, phase-shifting, hybrid, etc.), examples of other such patterning devices include a programmable mirror array and a programmable LCD array.

[0017] Figure 1 schematically depicts a lithographic apparatus LA. The lithographic apparatus LA includes an illumination system (also referred to as illuminator) IL configured to condition aradiation beam B (e.g., UV radiation, DUV radiation or EUV radiation), a mask support (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 MA in accordance with certain parameters, a substrate support (e.g., a wafer table) WT 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 support in accordance with certain parameters, and a 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] In operation, the illumination system IL receives a radiation beam from a radiation source SO, e.g. via a beam delivery system BD. The illumination system IL may include various types of optical components, such as refractive, reflective, magnetic, electromagnetic, electrostatic, and / or other types of optical components, or any combination thereof, for directing, shaping, and / or controlling radiation. The illuminator IL may be used to condition the radiation beam B to have a desired spatial and angular intensity distribution in its cross section at a plane of the patterning device MA.

[0019] The term “projection system” PS used herein should be broadly interpreted as encompassing various types of projection system, including refractive, reflective, catadioptric, anamorphic, magnetic, electromagnetic and / or electrostatic optical systems, or any combination thereof, as appropriate for the exposure radiation being used, and / 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” PS.

[0020] The lithographic apparatus LA may 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 PS and the substrate W - which is also referred to as immersion lithography. More information on immersion techniques is given in US6952253, which is incorporated herein by reference.

[0021] The lithographic apparatus LA may also be of a type having two or more substrate supports WT (also named “dual stage”). In such “multiple stage” machine, the substrate supports WT may be used in parallel, and / or steps in preparation of a subsequent exposure of the substrate W may be carried out on the substrate W located on one of the substrate support WT while another substrate W on the other substrate support WT is being used for exposing a pattern on the other substrate W.

[0022] In addition to the substrate support WT, the lithographic apparatus LA may comprise a measurement stage. The measurement stage is arranged to hold a sensor and / or a cleaning device. The sensor may be arranged to measure a property of the projection system PS or a property of the radiation beam B. The measurement stage may hold multiple sensors. The cleaning device may be arranged to clean part of the lithographic apparatus, for example a part of the projection system PS ora part of a system that provides the immersion liquid. The measurement stage may move beneath the projection system PS when the substrate support WT is away from the projection system PS.

[0023] In operation, the radiation beam B is incident on the patterning device, e.g. mask, MA which is held on the mask support MT, and is patterned by the pattern (design layout) present on patterning device MA. Having traversed the patterning device 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 a position measurement system PMS, the substrate support WT can be moved accurately, e.g., so as to position different target portions C in the path of the radiation beam B at a focused and aligned position. Similarly, the first positioner PM and possibly another position sensor (which is not explicitly depicted in Figure 1) may be used to accurately position the patterning device MA with respect to the path of the radiation beam B. Patterning device MA and substrate W may be aligned using mask alignment marks Ml, M2 and substrate alignment marks Pl, P2. Although the substrate alignment marks Pl, P2 as illustrated occupy dedicated target portions, they may be located in spaces between target portions. Substrate alignment marks Pl, P2 are known as scribe-lane alignment marks when these are located between the target portions C.

[0024] To clarify the invention, a Cartesian coordinate system is used. The Cartesian coordinate system has three axes, i.e., an x-axis, a y-axis and a z-axis. Each of the three axes is orthogonal to the other two axes. A rotation around the x-axis is referred to as an Rx-rotation. A rotation around the y- axis is referred to as an Ry-rotation. A rotation around about the z-axis is referred to as an Rz -rotation. The x-axis and the y-axis define a horizontal plane, whereas the z-axis is in a vertical direction. The Cartesian coordinate system is not limiting the invention and is used for clarification only. Instead, another coordinate system, such as a cylindrical coordinate system, may be used to clarify the invention. The orientation of the Cartesian coordinate system may be different, for example, such that the z-axis has a component along the horizontal plane.

[0025] Figure 2 shows a more detailed view of a part of the lithographic apparatus LA of Figure 1. The lithographic apparatus LA may be provided with a base frame BF, a balance mass BM, a metrology frame MF and a vibration isolation system IS. The metrology frame MF supports the projection system PS. Additionally, the metrology frame MF may support a part of the position measurement system PMS. The metrology frame MF is supported by the base frame BF via the vibration isolation system IS. The vibration isolation system IS is arranged to prevent or reduce vibrations from propagating from the base frame BF to the metrology frame MF.

[0026] The second positioner PW is arranged to accelerate the substrate support WT by providing a driving force between the substrate support WT and the balance mass BM. The driving force accelerates the substrate support WT in a desired direction. Due to the conservation of momentum, the driving force is also applied to the balance mass BM with equal magnitude, but at a direction opposite to the desired direction. Typically, the mass of the balance mass BM is significantly larger than the masses of the moving part of the second positioner PW and the substrate support WT.

[0027] In an embodiment, the second positioner PW is supported by the balance mass BM. For example, wherein the second positioner PW comprises a planar motor to levitate the substrate support WT above the balance mass BM. In another embodiment, the second positioner PW is supported by the base frame BF. For example, wherein the second positioner PW comprises a linear motor and wherein the second positioner PW comprises a bearing, like a gas bearing, to levitate the substrate support WT above the base frame BF.

[0028] The position measurement system PMS may comprise any type of sensor that is suitable to determine a position of the substrate support WT. The position measurement system PMS may comprise any type of sensor that is suitable to determine a position of the mask support MT. The sensor may be an optical sensor such as an interferometer or an encoder. The position measurement system PMS may comprise a combined system of an interferometer and an encoder. The sensor may be another type of sensor, such as a magnetic sensor, a capacitive sensor or an inductive sensor. The position measurement system PMS may determine the position relative to a reference, for example the metrology frame MF or the projection system PS. The position measurement system PMS may determine the position of the substrate table WT and / or the mask support MT by measuring the position or by measuring a time derivative of the position, such as velocity or acceleration.

[0029] The position measurement system PMS may comprise an interferometer system. An interferometer system is known from, for example, United States patent US6,020,964, filed on July 13, 1998, hereby incorporated by reference. The interferometer system may comprise a beam splitter, a mirror, a reference mirror and a sensor. A beam of radiation is split by the beam splitter into a reference beam and a measurement beam. The measurement beam propagates to the mirror and is reflected by the mirror back to the beam splitter. The reference beam propagates to the reference mirror and is reflected by the reference mirror back to the beam splitter. At the beam splitter, the measurement beam and the reference beam are combined into a combined radiation beam. The combined radiation beam is incident on the sensor. The sensor determines a phase or a frequency of the combined radiation beam. The sensor generates a signal based on the phase or the frequency. The signal is representative of a displacement of the mirror. In an embodiment, the mirror is connected to the substrate support WT. The reference mirror may be connected to the metrology frame MF. In an embodiment, the measurement beam and the reference beam are combined into a combined radiation beam by an additional optical component instead of the beam splitter.

[0030] The first positioner PM may comprise a long-stroke module and a short-stroke module. The short-stroke module is arranged to move the mask support MT relative to the long-stroke module with a high accuracy over a small range of movement. The long-stroke module is arranged to move the short-stroke module relative to the projection system PS with a relatively low accuracy over a large range of movement. With the combination of the long-stroke module and the short-stroke module, the first positioner PM is able to move the mask support MT relative to the projection system PS with a high accuracy over a large range of movement. Similarly, the second positioner PW maycomprise a long-stroke module and a short-stroke module. The short-stroke module is arranged to move the substrate support WT relative to the long-stroke module with a high accuracy over a small range of movement. The long-stroke module is arranged to move the short-stroke module relative to the projection system PS with a relatively low accuracy over a large range of movement. With the combination of the long-stroke module and the short-stroke module, the second positioner PW is able to move the substrate support WT relative to the projection system PS with a high accuracy over a large range of movement.

[0031] The first positioner PM and the second positioner PW each are provided with an actuator to move respectively the mask support MT and the substrate support WT. The actuator may be a linear actuator to provide a driving force along a single axis, for example the y-axis. Multiple linear actuators may be applied to provide driving forces along multiple axis. The actuator may be a planar actuator to provide a driving force along multiple axis. For example, the planar actuator may be arranged to move the substrate support WT in 6 degrees of freedom. The actuator may be an electromagnetic actuator comprising at least one coil and at least one magnet. The actuator is arranged to move the at least one coil relative to the at least one magnet by applying an electrical current to the at least one coil. The actuator may be a moving-magnet type actuator, which has the at least one magnet coupled to the substrate support WT respectively to the mask support MT. The actuator may be a moving-coil type actuator which has the at least one coil coupled to the substrate support WT respectively to the mask support MT. The actuator may be a voice-coil actuator, a reluctance actuator, a Lorentz-actuator or a piezo-actuator, or any other suitable actuator.

[0032] The lithographic apparatus LA comprises a position control system PCS as schematically depicted in Figure 3. The position control system PCS comprises a setpoint generator SP, a feedforward controller FF and a feedback controller FB. The position control system PCS provides a drive signal to the actuator ACT. The actuator ACT may be the actuator of the first positioner PM or the second positioner PW. The actuator ACT drives the plant P, which may comprise the substrate support WT or the mask support MT. An output of the plant P is a position quantity such as position or velocity or acceleration. The position quantity is measured with the position measurement system PMS. The position measurement system PMS generates a signal, which is a position signal representative of the position quantity of the plant P. The setpoint generator SP generates a signal, which is a reference signal representative of a desired position quantity of the plant P. For example, the reference signal represents a desired trajectory of the substrate support WT. A difference between the reference signal and the position signal forms an input for the feedback controller FB. Based on the input, the feedback controller FB provides at least part of the drive signal for the actuator ACT. The reference signal may form an input for the feedforward controller FF. Based on the input, the feedforward controller FF provides at least part of the drive signal for the actuator ACT. The feedforward FF may make use of information about dynamical characteristics of the plant P, such as mass, stiffness, resonance modes and eigenfrequencies.

[0033] Figure 4 shows an embodiment of a track interface 1 according to the invention. The track interface 1 is configured to to exchange substrates between a track 100 and a processing unit 200 of a substrate handling apparatus, for example a lithographic apparatus.

[0034] The processing unit 200 comprises a movable substrate support 201 configured to support a substrate 50 during a process in the processing unit 200, for example when a patterned beam of radiation is projected on the substrate 50. Figure 4 shows only one substrate support 201. In practice, the processing unit 200 may comprise multiple movable substrate supports 201, for example two, three, four or more movable substrate supports 201.

[0035] The track interface 1 comprises a first transfer unit 10 and a second transfer unit 20.

[0036] The first transfer unit 10 is configured to transfer a substrate 50 along a first loading transfer path 11 from the track 100 via a first substrate track receiving station 12 to at least one substrate support 201 of the processing unit 200 and to transfer a substrate 50 along a first unloading transfer path 13 from the at least one substrate support 201 of the processing unit 200 via a first substrate track discharge station 14 to the track 100.

[0037] The second transfer unit 20 is configured to transfer a substrate 50 along a second loading transfer path 21 from the track 100 via a second substrate track receiving station 22 to the at least one substrate support 201 of the processing unit 100 and to transfer a substrate 50 along a second unloading transfer path 23 from the at least one substrate support 201 of the processing unit 100 via a second substrate track discharge station 24 to the track 100.

[0038] In case the processing unit 200 comprises multiple substrate supports 201, each of the first transfer unit 10 and the second transfer unit 20 can be arranged to load and / or unload substrates on / from each of the plurality of substrate supports 201. For example, the first transfer unit 10 may load a substrate 50 on a first substrate support 201 and the second transfer unit 20 may unload this substrate 50 from the first substrate support 201, and vice versa.

[0039] The first transfer unit 10 comprises a first robot 15 to displace the substrate 50 between the first substrate track receiving station 12 and the at least one substrate support 201 and between the at least one substrate support 201 and the first substrate track discharge station 14. The second transfer unit 20 comprises a second robot 25 to displace the substrate between the second substrate track receiving station 22 and the at least one substrate support 201 and between the at least one substrate support 201 and the second substrate track discharge station 24.

[0040] The first robot 15 comprises a first object handler 15a to hold a substrate 50 and the second robot 25 comprises a second object handler 25a to hold a substrate 50. The first object handler 15a and the second object handler 25a may comprise a clamping device, such as a vacuum clamping device or an electrostatic clamping device to hold the substrate 50.

[0041] The first object handler 15a and the second object handler 25a are mounted on a robot arm. In alternative embodiments other positioners may be used to movably support the first object handler 15a or the second object handler 25a.

[0042] Each of the first and second transfer units 10, 20 comprises a single robot, e.g. first robot 15 and second robot 25, wherein each robot comprises a single object handler, e.g. first object handler 15a and second object handler 25a, each object handler being configure to hold a single substrate 50.

[0043] Figure 5 shows a side view of the first substrate track receiving station 12, the first substrate track discharge station 14, the second substrate track receiving station 22 and the second substrate track discharge station 24.

[0044] The first substrate track receiving station 12 and the first substrate track discharge station 14 are mutually vertically stacked, wherein the first substrate track receiving station 12 is arranged above the first substrate track discharge station 14. Correspondingly, the second substrate track receiving station 22 and the second substrate track discharge station 24 are mutually vertically stacked, wherein the second substrate track receiving station 22 is arranged above the second substrate track discharge station 24.

[0045] By arranging the first and second substrate track receiving stations 12, 22 above the first and second substrate track discharge stations 14, 24, respectively, an efficient use of space is obtained. The first and second substrate track receiving stations 12, 22 may further be provided with a buffer station for buffering substrates between the processing unit 200 and the track 100.

[0046] Substrates 50 are located in the first substrate track receiving station 12, the second substrate track receiving station 22 and in the second substrate track discharge station 24. The position in which the first substrate track discharge station 14 may hold a substrate is indicated in dashed lines.

[0047] The first substrate track receiving station 12 comprises a first temperature conditioning device 16 and the second substrate track receiving station 22 comprises a second temperature conditioning device 26. The first temperature conditioning device 16 and the second temperature conditioning device 26 are configured to condition the temperature of the substrate 50 in the first substrate track receiving station 12 and the second substrate track receiving station 22, respectively.This allows temperature conditioning of the substrate 50 before it is loaded on one of the plurality of moveable substrate support the movable substrate support 201.

[0048] The first temperature conditioning device 16 and the second temperature conditioning device 26 may be embodied as a chill plate, as shown in Figure 5, and / or as an air shower or other device capable of conditioning the temperature of the substrate 50 positioned on the first substrate track receiving station 12 and second substrate track receiving station 22, respectively.

[0049] Further, the first substrate track receiving station 12 comprises a first alignment measurement device 17. The first alignment measurement device 17 is configured to measure alignment of a substrate 50 in the first substrate track receiving station 12. By measuring alignment of the substrate 50 with respect to the first substrate track receiving station 12, the position of the substrate 50 may be determined before it is loaded by the first robot 15 on the substrate support 201. This measured position can be used to more accurately place the substrate 50 on the substrate support201. After being placed on the substrate support 201 further alignment measurements may be carried out to determine specific positions of the substrate 50 with respect to the substrate support 201.

[0050] Correspondingly, the second substrate track receiving station 22 comprises a second alignment measurement device 27 configured to measure alignment of a substrate 50 in the second substrate track receiving station 22. By measuring alignment of the substrate 50 with respect to the second substrate track receiving station 22, the position of the substrate 50 may be determined before it is loaded by the second robot 25 on the substrate support 201.

[0051] The first alignment measurement device 17 and the second alignment measurement device 27 may be used to determine a coarse position of the substrate 50 with respect to the respective substrate track receiving station 12, 24, for example by using a sensor that measures the edge of the substrate 50 and a rotation device that rotates the substrate to enable the sensor to measure the edge of the substrate 50 along the circumference of the substrate 50.

[0052] In addition or as an alternative embodiment, alignment measurement devices may be mounted on the first robot 15 and the second robot 25.

[0053] In the embodiment shown in Figures 4 and 5, the first substrate track receiving station 12 and the first substrate track discharge station 14 are separate stations that are mutually vertically stacked. In an alternative embodiment, the first substrate track receiving station 12 and the first substrate track discharge station 14 may also be arranged next to each other, or the first substrate track receiving station 12 may be arranged below the first substrate track discharge station 14. In yet an alternative embodiment, the first substrate track receiving station 12 and the second substrate track discharge station 14 are provided as a single substrate track loading and receiving station. Such single substrate track loading and receiving station may be capable of holding a single substrate or more than one substrates.

[0054] Similarly, the second substrate track receiving station 22 and the second substrate track discharge station 24 may be arranged next to each other or the second substrate track receiving station 22 may be arranged below the second substrate track discharge station 24. In an alternative embodiment, the second substrate track receiving station 22 and the second substrate track discharge station 24 may be provided as a single substrate track loading and receiving station capable of holding a single substrate or, as an alternative, multiple substrates.

[0055] Now again referring to Figure 4, the first loading transfer path 11 and the first unloading transfer path 13 are schematically shown with dashed arrows. In practice, these first loading and unloading transfer paths 11, 13 may partially or completely overlap. Correspondingly, the second loading transfer path 21 and the second unloading transfer path 23 are schematically shown in Figure 4 with dashed arrows. In practice, these second transfer paths 21, 23 may also partially or completely overlap.

[0056] However, in accordance with the invention, the first loading and unloading transfer paths 11, 13 are separated from the second loading and unloading transfer paths 21, 23. Separated meansthat a transfer of a substrate 50 between the track 100 and the substrate support 201 along the first loading and unloading transfer paths 11, 13 will within the track interface 1 not hinder or block a transfer of a substrate 50 along the second loading and unloading transfer paths 21, 23.

[0057] As a result, the first transfer unit 10 and the second transfer unit 20 may act independently from each other with respect to transfers of substrates within the track interface 1. The track interface 1 may therefore be arranged to load substrates from the track 100 on the substrate support 201 using alternatingly the first transfer unit 10 and the second transfer unit 20. Similarly, the track interface 1 may be arranged to unload substrates 50 from the substrate support 201 to the track 100 using alternatingly the first transfer unit 10 and the second transfer unit 20.

[0058] As shown in Figure 5, the first substrate track receiving station 12 may hold a new substrate 50 which is placed by the track 100 in this position. In the first substrate track receiving station 12, the temperature of the new substrate 50 may be conditioned by the first temperature conditioning device 16 to a desired temperature. At the same time the alignment measurement device 17 may be used to measure a coarse position of the substrate 50 on the first substrate track receiving station 12. Correspondingly, the second substrate track receiving station 22 may hold a further new substrate 50 which is placed by the track 100 in this position. In the second substrate track receiving station 22, the further new substrate 50 may also be temperature conditioned and aligned.

[0059] Further, in the processing unit 200 a substrate 50 may be supported by a substrate support 201. As soon as the processing unit 200 has finished processing of the substrate 50, the substate support 201 may be positioned in a position in which the interface track 1 may take the substrate 50 from the substrate support 201. Once the processed substrate 50 has been taken from the substrate support 201, the new substrate 50 may be placed on the substrate support 201 for processing of the substrate 50. As the processing of the substrate 50 is part of the critical time path of the lithographic apparatus LA, the unloading of the processed substrate 50 and loading of the new substrate 50 should be carried out efficiently.

[0060] Figure 6 shows that the second robot 25 takes a processed substrate 50 from the substrate support 201. The first robot 15 holds the new substrate 50 which was displaced from the first substrate track receiving station 12 to a position relatively close to the substrate support 201. As soon as the new substrate 50 has been taken out of the first substrate track receiving station 12 another further new substrate 50 can be placed in this first substrate track receiving station 12 for temperature conditioning and alignment measurements.

[0061] As soon as the second robot 25 has moved the processed substrate 50 away from the substrate support 201, the first robot 15 may place the new substrate 50 on the substrate support 201 for processing of the new substrate 50 in the processing unit 200.

[0062] The processed substrate 50 held by the second robot 25 will be displaced by the second robot 25 to the second substrate track discharge station 24.

[0063] Figure 7 shows the second robot 25 placing the processed substrate 50 into the second substrate track discharge station 24. The second substrate track receiving station 22 holds the further new substrate 50 and the first substrate track receiving station 12 holds the another further new substrate 50. Since the second substrate track receiving station 22 and the second substrate track discharge station 24 are separate stations, the presence of the further new substrate 50 in the second substrate track receiving station 22 does not hinder the placement of the processed substrate 50 in the second substrate track discharge station 24.

[0064] The track 100 may take the processed substrate 50 from the track interface 1, in particular the second substrate track discharge station 24, and move the processed substrate 50 further away from the processing unit 50, for example to a storage device or a unit for further processing of the substrate.

[0065] The first robot 15 may remain in a position or close to a position in which the first robot 15 can take a new processed substrate 50 from the substrate support 201. This may be the same substrate support 201 as the one on which the first robot 15 has previously placed the new substrate 50, or it may be another substrate support 201 in case the processing unit 200 comprises multiple substrate supports 201, such as a twin-scan, tri-scan or quad-scan lithographic apparatus.

[0066] The second robot 25 may be positioned to take the further new substrate 50 from the second substrate track receiving station 22 before the first robot 15 takes the new processed substrate 50 from the substrate support 201, such that the further new substrate 50 can be placed on the substrate support 201 directly after the new processed substrate 50 has been taken from this substrate support 201.

[0067] In this way, the first transfer unit 10 and the second transfer unit 20 can be alternately used to load and unload substrates 50 on and from one or more substrate supports 201 of the processing unit 200.

[0068] The presence of a substrate 50 in the first substrate track receiving station 12 or the second substrate track receiving station 22, does not hinder the unloading of a substrate 50 from the processing unit 200 to the track 100. As a result, the configuration of the interface track 1 discussed above is very efficient in transferring substrates 50 between the track 100 and the processing unit 200, while allowing relatively large time for temperature conditioning and alignment measurements in the first and second substrate track receiving stations 12, 22.

[0069] The track interface 1 may therefore be suitable to transfer at least 500 substrates per hour from the track 100 to the processing unit 200 and from the processing unit 200 back to the track 100.

[0070] Moreover, the track interface 1 may be designed within the same overall dimensions as the track interface shown in Figure 7 of US 7,345,736 B2. Therefore, within the same space a track interface 1 may be provided having a substantial larger throughput capacity than the track interface of US 7,345,736 B2.

[0071] Figure 8 shows an alternative embodiment of a track interface 1 comprises a first transfer unit 10 and a second transfer unit 20.

[0072] The first transfer unit 10 comprises a first robot 15 to transfer a substrate 50 along a first loading transfer path 11 from a substrate track receiving station 32 to at least one substrate support 201 of the processing unit 200 and to transfer a substrate 50 along a first unloading transfer path 13 from the at least one substrate support 201 of the processing unit 200 to a substrate track discharge station 34.

[0073] The second transfer unit 20 comprises a second robot 25 to transfer a substrate 50 along a second loading transfer path 21 from the track 100 from the substrate track receiving station 32 to the at least one substrate support 201 of the processing unit 100 and to transfer a substrate 50 along a second unloading transfer path 23 from the at least one substrate support 201 of the processing unit 100 to the substrate track discharge station 34.

[0074] Thus, in this embodiment the first transfer unit 10 and the second transfer unit 20 together use a single substrate track receiving station 32 and a single substrate track discharge station 34.

[0075] The substrate track receiving station 32 is arranged above the substrate track discharge station 34. The first robot 15 comprises a first object handler 15a to hold a single substrate 50 and the second robot 25 comprises a second object handler 25a to hold a single substrate 50.

[0076] Hereinabove, a track interface 1 has been described to move substrates between a track 100 and a processing unit 200, in particular a lithographic apparatus. The track interface may also be used in any other substrate processing apparatus comprising a track and a processing unit to load a substrate from the track to the substrate support of the processing unit and / or to unload a substrate from the substrate support to the track.

[0077] Hereinabove, a track interface 1 has been described to move substrates between a track 100 and a processing unit 200. The track is typically a device used to transport substrates, for example between different substrate processing and / or storage devices. The track may be any device configured to transport substrates towards and away from a processing unit of a substrate handling apparatus.

[0078] Although specific reference may be made in this text to the use of a lithographic apparatus in the manufacture of ICs, it should be understood that the lithographic apparatus described herein may have other applications. Possible other applications include 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.

[0079] Although specific reference may be made in this text to embodiments of the invention in the context of a lithographic apparatus, embodiments of the invention may be used in other apparatus. Embodiments of the invention may form part of a mask inspection apparatus, a metrology apparatus, or any apparatus that measures or processes an object such as a wafer (or other substrate) or mask (orother patterning device). These apparatus may be generally referred to as lithographic tools. Such a lithographic tool may use vacuum conditions or ambient (non- vacuum) conditions.

[0080] Although specific reference may have been made above to the use of embodiments of the invention in the context of optical lithography, it will be appreciated that the invention, where the context allows, is not limited to optical lithography and may be used in other applications, for example imprint lithography.

[0081] Where the context allows, embodiments of the invention may be implemented in hardware, firmware, software, or any combination thereof. Embodiments of the invention may also be implemented as instructions stored on a machine -readable medium, which may be read and executed by one or more processors. A machine -readable medium may include any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computing device). For example, a machine -readable medium may include read only memory (ROM); random access memory (RAM); magnetic storage media; optical storage media; flash memory devices; electrical, optical, acoustical or other forms of propagated signals (e.g. carrier waves, infrared signals, digital signals, etc.), and others. Further, firmware, software, routines, instructions may be described herein as performing certain actions. However, it should be appreciated that such descriptions are merely for convenience and that such actions in fact result from computing devices, processors, controllers, or other devices executing the firmware, software, routines, instructions, etc. and in doing that may cause actuators or other devices to interact with the physical world.

[0082] While specific embodiments of the invention have been described above, it will be appreciated that the invention may be practiced otherwise than as described. 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. Other aspects of the invention are set out as in the following numbered clauses: 1. A track interface for exchanging substrates between a track and a processing unit of a substrate handling apparatus, for example a lithographic apparatus, the track interface comprising: a first transfer unit configured to transfer a substrate along a first loading transfer path from one or more substrate track receiving stations to the processing unit and to transfer a substrate along a first unloading transfer path from the processing unit to one or more substrate track discharge stations, and a second transfer unit configured to transfer a substrate along a second loading transfer path from the one or more substrate track receiving stations to the processing unit and to transfer a substrate along a second unloading transfer path from the processing unit to the one or more substrate track discharge stations, wherein each of the one or more substrate track receiving stations is arranged to receive a substrate from the track and wherein each of the one or more substrate track discharge stations is arranged to discharge a substrate to the track,wherein the first loading and unloading transfer paths are separated from the second loading and unloading transfer paths.2. The track interface of clause 1 , wherein each of the one or more substrate track receiving stations comprises an alignment measurement device to measure alignment of a substrate with respect to a respective one of the one or more substrate track receiving stations.3. The track interface of clause 1 or 2, wherein each of the one or more substrate track receiving stations comprises a temperature conditioning device.4. The track interface of any of the clauses 1-3, wherein each of the one or more substrate track receiving stations is vertically stacked with an associated one of the one or more substrate track receiving stations.5. The track interface of clause 4, wherein a respective one of the one or more substrate track receiving stations is arranged above the associated one of the one or more substrate track discharge stations.6. The track interface of any of the preceding clauses, wherein the first transfer unit is configured to transfer a substrate along the first loading transfer path from a first substrate track receiving station of the one or more substrate track receiving stations to the processing unit and to transfer a substrate along a first unloading transfer path from the processing unit to a first substrate track discharge station of the one or more substrate track discharge stations, and wherein the second transfer unit is configured to transfer a substrate along the second loading transfer path from a second substrate track receiving station of the one or more substrate track receiving stations to the processing unit and to transfer a substrate along the second unloading transfer path from the processing unit to a second substrate track discharge station of the one or more substrate track discharge stations.7. The track interface of clause 6, wherein the first transfer unit comprises a first robot to displace a substrate between the first substrate track receiving station and the processing unit and between the processing unit and the first substrate track discharge station, and wherein the second transfer unit comprises a second robot to displace a substrate between the second substrate track receiving station and the processing unit and between the processing unit and the second substrate track discharge station.8. The track interface of any of the clauses 1-5, wherein the track interface comprises one substrate track receiving station and one substrate track discharge station, wherein the first transfer unit is configured to transfer a substrate along the first loading transfer path from the substrate track receiving station to the processing unit and to transfer a substrate along a first unloading transfer path from the processing unit to the substrate track discharge station, andwherein the second transfer unit is configured to transfer a substrate along the second loading transfer path from the substrate track receiving station to the processing unit and to transfer a substrate along the second unloading transfer path from the processing unit to the substrate track discharge station.9. The track interface of clause 8, wherein the first transfer unit comprises a first robot to displace a substrate between the substrate track receiving station and the processing unit and between the processing unit and the substrate track discharge station, and wherein the second transfer unit comprises a second robot to displace a substrate between the substrate track receiving station and the processing unit and between the processing unit and the substrate track discharge station.10. The track interface of clause 7 or 9, wherein the first robot and the second robot are each configured to hold a single substrate.11. The track interface of any of the preceding clauses, wherein the track interface is arranged to load substrates from the track into the processing unit using alternatingly the first transfer unit and the second transfer unit.12. The track interface of any of the preceding clauses, wherein the track interface is arranged to unload substrates from the processing unit to the track using alternatingly the first transfer unit and the second transfer unit.13. The track interface of any of the preceding clauses, wherein the track interface is configured to transfer at least 500 substrates per hour from the track to the processing unit and from the processing unit back to the track.14. A substrate processing apparatus, comprising: a processing unit configured to perform a process involving substrates, the processing unit comprising at least one movable substrate support configured to hold a substrate; and the track interface of any of the preceding clauses to load the substrate from the track on the at least one substrate support and / or to unload the substrate from the at least one substrate support to the track.15. The substrate processing apparatus of clause 14, wherein the substrate processing apparatus is a lithographic apparatus.16. The substrate processing apparatus of clause 14 or 15, wherein the processing unit is configured to perform a lithographic process involving substrates, the processing unit comprising: an illumination system for conditioning a beam of radiation; a support structure configured to support a patterning device that imparts a pattern to the beam of radiation to create a patterned beam; and a projection system configured to project the patterned beam onto a target portion of the substrate.17. The substrate processing apparatus of any of the clauses 14-16, wherein the substrate handling apparatus comprises a track to transport substrates towards and away from the processing unit.18. The substrate processing apparatus of clause 17, wherein the track is arranged to place a substrate at the one or more substrate track receiving stations and wherein the track is arranged to remove a substrate from the one or more substrate track discharge stations.19. The substrate processing apparatus of any of the clauses 14-18, wherein the processing apparatus comprises multiple movable substrate supports, wherein each of the first transfer unit and the second transfer unit of the track interface is configured to load substrates from the track on each of the multiple substrate supports and / or to unload substrates from each of the multiple substrate supports to the track.

Claims

CLAIMS1. A track interface for exchanging substrates between a track and a processing unit of a substrate handling apparatus, for example a lithographic apparatus, the track interface comprising: a first transfer unit configured to transfer a substrate along a first loading transfer path from one or more substrate track receiving stations to the processing unit and to transfer a substrate along a first unloading transfer path from the processing unit to one or more substrate track discharge stations, and a second transfer unit configured to transfer a substrate along a second loading transfer path from the one or more substrate track receiving stations to the processing unit and to transfer a substrate along a second unloading transfer path from the processing unit to the one or more substrate track discharge stations, wherein each of the one or more substrate track receiving stations is arranged to receive a substrate from the track and wherein each of the one or more substrate track discharge stations is arranged to discharge a substrate to the track, wherein the first loading and unloading transfer paths are separated from the second loading and unloading transfer paths.

2. The track interface of claim 1 , wherein each of the one or more substrate track receiving stations comprises an alignment measurement device to measure alignment of a substrate with respect to a respective one of the one or more substrate track receiving stations.

3. The track interface of claim 1 or 2, wherein each of the one or more substrate track receiving stations comprises a temperature conditioning device.

4. The track interface of any of the claims 1-3, wherein each of the one or more substrate track receiving stations is vertically stacked with an associated one of the one or more substrate track receiving stations.

5. The track interface of claim 4, wherein a respective one of the one or more substrate track receiving stations is arranged above the associated one of the one or more substrate track discharge stations.

6. The track interface of any of the preceding claims, wherein the first transfer unit is configured to transfer a substrate along the first loading transfer path from a first substrate track receiving station of the one or more substrate track receiving stations to the processing unit and to transfer a substrate along a first unloading transfer path from theprocessing unit to a first substrate track discharge station of the one or more substrate track discharge stations, and wherein the second transfer unit is configured to transfer a substrate along the second loading transfer path from a second substrate track receiving station of the one or more substrate track receiving stations to the processing unit and to transfer a substrate along the second unloading transfer path from the processing unit to a second substrate track discharge station of the one or more substrate track discharge stations.

7. The track interface of claim 6, wherein the first transfer unit comprises a first robot to displace a substrate between the first substrate track receiving station and the processing unit and between the processing unit and the first substrate track discharge station, and wherein the second transfer unit comprises a second robot to displace a substrate between the second substrate track receiving station and the processing unit and between the processing unit and the second substrate track discharge station.

8. The track interface of any of the claims 1-5, wherein the track interface comprises one substrate track receiving station and one substrate track discharge station, wherein the first transfer unit is configured to transfer a substrate along the first loading transfer path from the substrate track receiving station to the processing unit and to transfer a substrate along a first unloading transfer path from the processing unit to the substrate track discharge station, and wherein the second transfer unit is configured to transfer a substrate along the second loading transfer path from the substrate track receiving station to the processing unit and to transfer a substrate along the second unloading transfer path from the processing unit to the substrate track discharge station.

9. The track interface of claim 8, wherein the first transfer unit comprises a first robot to displace a substrate between the substrate track receiving station and the processing unit and between the processing unit and the substrate track discharge station, and wherein the second transfer unit comprises a second robot to displace a substrate between the substrate track receiving station and the processing unit and between the processing unit and the substrate track discharge station.

10. The track interface of claim 7 or 9, wherein the first robot and the second robot are each configured to hold a single substrate.

11. The track interface of any of the preceding claims, wherein the track interface is arranged to load substrates from the track into the processing unit using alternatingly the first transfer unit and the second transfer unit.

12. The track interface of any of the preceding claims, wherein the track interface is arranged to unload substrates from the processing unit to the track using alternatingly the first transfer unit and the second transfer unit.

13. The track interface of any of the preceding claims, wherein the track interface is configured to transfer at least 500 substrates per hour from the track to the processing unit and from the processing unit back to the track.

14. A substrate processing apparatus, comprising: a processing unit configured to perform a process involving substrates, the processing unit comprising at least one movable substrate support configured to hold a substrate; and the track interface of any of the preceding claims to load the substrate from the track on the at least one substrate support and / or to unload the substrate from the at least one substrate support to the track.

15. The substrate processing apparatus of claim 14, wherein the substrate handling apparatus comprises a track to transport substrates towards and away from the processing unit.

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