Measurement equipment and substrate stage / handler systems

Abstract

To improve through put performance and / or profitability of a measurement device.SOLUTION: A measurement device comprises: a first measurement device; a second measurement device; a first substrate stage which is configured to hold the first substrate and / or second substrate; a second substrate stage which is configured to hold the first substrate and / or second substrate; a first substrate handler which is configured to perform handling of the first substrate and / or second substrate; and a second substrate handler which is configured to perform handling of the first substrate and / or second substrate. The first substrate is loaded from a first, second or third FOUP, the second substrate is loaded from the first, second or third FOUP, the first measurement device is an alignment measurement device, the second measurement device is a level sensor, a thickness measurement device or spectral reflectance measurement device.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] A first aspect of the invention relates to an alignment measurement apparatus and a method for measuring the position of an alignment mark on a substrate.

[0002] A second aspect of the invention relates to a lithographic apparatus and a substrate stage handler system.

[0003] A third aspect of the present invention relates to a measurement device. [Background technology]

[0004] A lithographic apparatus is a machine that applies a desired pattern onto a substrate, usually onto a target portion of the substrate. Lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs). In such cases, a patterning device, alternatively called a mask or reticle, can 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. comprising part of one or several dies) on the substrate (e.g. a silicon wafer). The transfer of the pattern is typically by 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 which are successively patterned. Conventional lithographic apparatus include so-called steppers, in which each target portion is irradiated by exposing the entire pattern onto the target portion in one go, and so-called scanners, in which each target portion is irradiated by scanning the pattern with a radiation beam in a given direction (the "scan" direction) while synchronously scanning the substrate parallel or anti-parallel to the given direction (the "scan" direction). It is also possible to transfer the pattern from the patterning device to the substrate by imprinting the pattern onto the substrate.

[0005] In known embodiments of the lithographic apparatus, the lithographic apparatus comprises an alignment measurement system for measuring positions of alignment marks provided on the substrate. By measuring the positions of these alignment marks, a position and / or deformation of the substrate can be determined relative to a substrate table that holds the substrate. This measured position and / or deformation of the substrate enables the lithographic apparatus to position the substrate in a desired position relative to the projection system and / or patterning device during the actual projection of the patterned radiation beam onto a target portion of the substrate.

[0006] In this way, successive projections of the patterned radiation beam onto target portions of the substrate can be aligned with respect to one another. Overlay performance, i.e. the alignment of successive projections of the patterned radiation beam onto target portions of the substrate, is a key factor in the product quality of devices manufactured using the lithographic apparatus.

[0007] There is a general need to improve the overlay performance of lithographic apparatus in order to improve product quality. The overlay performance can be improved, for example, by measuring a substantially larger number of alignment marks on a substrate. In particular, the substrate alignment grid may contain high frequency components of distortion that can be better corrected by measuring a larger number of alignment marks. However, measuring a larger number of alignment marks increases the alignment measurement time, which has a limiting impact on the production performance of the lithographic apparatus.

[0008] Furthermore, during the device measurement process, the substrate undergoes multiple processing steps such as layer deposition, etching, annealing, etc. The impact of these processing steps on the overlay performance of the lithography process is also significant, usually resulting in variations between substrates and / or between stacks of substrates and / or between layers of substrates.

[0009] Conventionally, devices equipped with a single substrate stage for measuring (or inspecting) one type of characteristic of a substrate have been proposed (see, for example, Patent Documents 1 to 4). However, when such conventional technology is adopted, in order to measure (and / or inspect) multiple characteristics of the same substrate, multiple devices for measuring (and / or inspecting) different types of characteristics are required. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] JP 2007-250578 A [Patent Document 2] JP 2012-202980 A [Patent Document 3] JP 2006-135211 A [Patent Document 4] International Publication No. 2012 / 115013 Brochure Summary of the Invention

[0011] It is an object of the present invention to provide an apparatus and / or method for measuring the positions of multiple alignment marks on a substrate that is capable of measuring a large number of alignment marks and / or that can better deal with variations between substrates and / or between stacks of substrates and / or between layers of substrates. It is also an object of the present invention to provide a unified metrology (inspection) apparatus with multiple substrate stages that can measure (inspect) multiple types of characteristics of a substrate. In other words, to improve the throughput performance and / or economy (which may be perceived in terms of, for example, cost of ownership, product price or footprint) of the overall metrology and inspection apparatus.

[0012] According to an aspect of the present invention, a first station comprising a first alignment sensor system for measuring positions of a first number of alignment marks on the substrate and a first level sensor for measuring a height map of a top surface of the substrate; a second station comprising a second alignment sensor system for measuring positions of a second number of alignment marks on the substrate and a second level sensor for measuring a height map of the top surface of the substrate; a movable substrate table constructed to hold a substrate, the substrate table arranged to move to a first station and to a second station; An alignment measurement apparatus for measuring a position of an alignment mark on a substrate is provided, comprising:

[0013] According to an aspect of the present invention, a support constructed to support a patterning device, the patterning device being capable of imparting the radiation beam with a pattern in its cross-section to form a patterned radiation beam; and a substrate table constructed to hold a substrate; a projection system configured to project the patterned beam of radiation onto a target portion of a substrate; a lithographic apparatus comprising: An alignment measurement device according to claim 1; one or more substrate handlers for transporting substrates between respective substrate tables of the alignment measurement apparatus and a substrate table of the lithographic apparatus; A lithography system is provided, comprising:

[0014] According to an aspect of the present invention, Measuring positions of a first number of alignment marks on a substrate at a first station; measuring positions of a second number of alignment marks on the substrate at a second station; the substrate is held by the same substrate table at the first station and at the second station; Using the measured positions of the first number of alignment marks measured at the first station for measuring the positions of a second number of alignment marks at the second station. A method is provided for measuring the position of an alignment mark on a substrate, comprising:

[0015] According to an aspect of the present invention, - measuring the positions of a first number of alignment marks on the substrate in a first station of the alignment measurement apparatus; and / or measuring positions of a second number of alignment marks on the substrate at a second station of the alignment measurement apparatus; the substrate table holds a substrate at the first station and / or the second station; - transferring a substrate from a substrate table of the alignment measurement apparatus to a substrate table of the lithographic apparatus using one or more substrate handlers; and projecting a patterned beam of radiation onto a substrate in a lithographic apparatus using measurements of the positions of the first and / or second number of alignment marks; There is provided a device manufacturing method comprising projecting a patterned beam of radiation onto a substrate, the method comprising:

[0016] According to an aspect of the present invention, a patterning device support for supporting a patterning device; a first substrate table, a second substrate table, and a third substrate table, each constructed to support a substrate; a first station comprising an alignment sensor system for measuring the positions of several alignment marks on the substrate and / or a level sensor for measuring a height map of a top surface of the substrate; a second station comprising an exposure unit for transferring a pattern from a patterning device to a substrate; a substrate table positioning system for moving each of the first substrate table, the second substrate table and the third substrate table within a planar range of motion at least between the first station and the second station; There is provided a lithographic apparatus comprising: a first cable connection is provided between the first substrate table and the first cable connection support, a second cable connection is provided between the second substrate table and the second cable connection support, and a third cable connection is provided between the third substrate table and the third cable connection support; A first linear guide is provided for guiding the first cable connection support and the third cable connection support on a first side of the planar movement area, and a second linear guide is provided for guiding the second cable connection support on a second side of the planar movement area opposite the first side.

[0017] According to an aspect of the present invention, A first measuring device; A second measurement device; and a first substrate stage configured to hold a first substrate and / or a second substrate; a second substrate stage configured to hold the first substrate and / or the second substrate; a first substrate handler configured to handle the first substrate and / or the second substrate; a second substrate handler configured to handle the first substrate and / or the second substrate; A first substrate is loaded from a first FOUP (Front-Opening Unified Pod), a second FOUP, or a third FOUP; a second substrate is loaded from the first FOUP, the second FOUP, or the third FOUP; the first measurement device is an alignment measurement device; The second measurement device is a level sensor, a film thickness measurement device, or a spectral reflectance measurement device. A measurement device is provided.

[0018] Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, in which: [Brief description of the drawings]

[0019] [Figure 1] 1 depicts a lithographic apparatus according to an aspect of the present invention; [Diagram 2] 1 illustrates a schematic diagram of a lithography system according to an embodiment of the present invention; [Diagram 3] 1 is a schematic diagram of an alignment measurement apparatus according to an embodiment of the present invention; [Figure 4] FIG. 1 illustrates a substrate stage handler system according to a first embodiment of an aspect of the present invention. [Diagram 5] FIG. 1 depicts a side view of a part of a lithographic apparatus; [Figure 6] FIG. 2 illustrates a substrate stage handler system according to a second embodiment of an aspect of the present invention. [Figure 7] FIG. 13 illustrates a substrate stage handler system according to a third embodiment of an aspect of the present invention. [Figure 8] FIG. 10 illustrates a substrate stage handler system according to a fourth embodiment of an aspect of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] 1 depicts a schematic diagram of a lithographic apparatus that may be part of a lithographic system according to one embodiment of the present invention. The lithographic apparatus comprises an illumination system IL, a support structure MT, a substrate table WT, and a projection system PS.

[0021] The illumination system IL is configured to condition the radiation beam B. The support structure MT (e.g. a mask table) is configured to support a patterning device MA (e.g. a mask) and is connected to a first positioner PM configured to accurately position the patterning device according to certain parameters. The substrate table WT (e.g. a wafer table) is configured to hold a substrate W (e.g. a resist-coated wafer) and is connected to a second positioner PW configured to accurately position the substrate according to certain parameters. The projection system PS is configured to project a pattern imparted to the radiation beam B by the patterning device MA onto a target portion C of the substrate W (e.g. comprising one or more dies).

[0022] The illumination system IL may include various types of optical components, such as refractive, reflective, magnetic, electromagnetic, electrostatic or other types of optical components, or any combination thereof, for directing, shaping or controlling radiation.

[0023] As used herein, the term "radiation beam" encompasses all types of electromagnetic radiation, including ultraviolet (UV) radiation (e.g., having a wavelength of 365 nm, 355 nm, 248 nm, 193 nm, 157 nm or 126 nm, or thereabouts), and extreme ultraviolet (EUV) radiation (e.g., having a wavelength in the range of 5 nm to 20 nm), as well as particle beams such as ion beams or electron beams.

[0024] The support structure MT supports, i.e. bears the weight of, the patterning device MA. It holds the patterning device in a manner that depends on the orientation of the patterning device MA, the design of the lithographic apparatus, and other conditions, for example whether or not the patterning device MA is held in a vacuum environment. The support structure MT can use mechanical, vacuum, electrostatic or other clamping techniques to hold the patterning device MA. The support structure MT may be for example a frame or a table, which may be fixed or movable as required. The support structure MT may ensure that the patterning device MA is at a desired position, for example with respect to the projection system PS.

[0025] The term "patterning device" as used herein should be interpreted broadly as referring to any device that can be used to impart a pattern to a radiation beam B in its cross-section to create a pattern in a target portion C of a substrate W. It should be noted that the pattern imparted to the radiation beam B may not exactly correspond to the desired pattern in the target portion C of the substrate W if, for example, the pattern includes phase-shifting features or so-called assist features. Generally, the pattern imparted to the radiation beam corresponds to a particular functional layer of a device being created in the target portion C, such as an integrated circuit.

[0026] The patterning device MA 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 to the radiation beam which is reflected by the mirror matrix.

[0027] The term "projection system" as used in this specification should be interpreted broadly as covering any type of projection system including, for example, refractive optical systems, reflective optical systems, catadioptric optical systems, magnetic optical systems, electromagnetic optical systems and electrostatic optical systems, or any combination thereof, as appropriate depending on, for example, the exposure radiation used, or other factors such as the use of an immersion liquid or the use of a vacuum.

[0028] As here depicted, the apparatus may be of a transmissive type (e.g. employing a transmissive mask) or it 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).

[0029] The lithographic apparatus may be of a type having two (dual stage) or more substrate tables WT (and / or two or more mask tables). In such a "multi-stage" machine, the additional tables may be used in parallel, or a preliminary step may be performed on one or more tables while one or more of the other tables are being used for exposure. In addition to the one or more substrate tables WT, the lithographic apparatus may have a measurement stage, which is arranged to be in a position under the projection system PS when the substrate table WT is away from that position. Instead of supporting the substrate W, the measurement stage may be provided with sensors for measuring properties of the lithographic apparatus. For example, the projection system may project an image onto a sensor on the measurement stage to determine the image quality.

[0030] The lithographic apparatus may be of a type in which at least a portion of the substrate W may be covered with a liquid having a relatively high refractive index, such as water, so as to fill a space between the projection system and the substrate. Immersion liquids may also be applied to other spaces in the lithographic apparatus, for example between the patterning device MA and the projection system PS. Immersion techniques are well known in the art for increasing the numerical aperture of projection systems. As used herein, the term "immersion" does not mean that a structure such as the substrate W must be submerged in liquid, but rather that a liquid is present between the projection system PS and the substrate W during exposure.

[0031] With reference to Figure 1, the illumination system IL receives a radiation beam from a radiation source SO. The radiation source SO and the lithographic apparatus may be separate entities, for example when the radiation source SO is an excimer laser. In such a case, the radiation source is not considered to form part of the lithographic apparatus and the radiation beam B is passed from the radiation source SO to the illumination system IL with the aid of a beam delivery system BD, for example comprising suitable directing mirrors and / or beam expanders. In other cases the radiation source SO may be an integral part of the lithographic apparatus, for example when the radiation source SO is a mercury lamp. The radiation source SO and the illumination system IL, together with the beam delivery system BD if required, may be referred to as a radiation system.

[0032] The illumination system IL may comprise an adjuster AD for adjusting the angular intensity distribution of the radiation beam. Generally, the outer and / or inner radial extent (commonly referred to as σ-outer and σ-inner, respectively) of the intensity distribution in a pupil plane of the illumination system may be adjusted. The illumination system IL may also comprise various other components, such as an integrator IN and a condenser CO. The illumination system IL may be used to adjust the radiation beam to have a desired uniformity and intensity distribution across its cross-section.

[0033] The radiation beam B is incident on the patterning device MA, which is held on the support structure MT, and is patterned by the 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 a second positioner PW and a position sensor IF (e.g. an interferometric device, a linear encoder or a capacitive sensor), the substrate table WT can be accurately moved, for example to position different target portions C in the path of the radiation beam B. Similarly, the first positioner PM and another position sensor (not explicitly shown in Figure 1) can be used to accurately position the patterning device MA with respect to the path of the radiation beam B, for example after mechanical retrieval from a mask library or during a scan. In general, movement of the support structure MT can be realised with the aid of a long-stroke module and a short-stroke module, which form part of the first positioner PM. The long-stroke module can provide coarse positioning of the short-stroke module over a wide range of movements. The short-stroke module may provide fine positioning of the support structure MT relative to the long-stroke module over a small range of movement. Similarly, movement of the substrate table WT may be realized using a long-stroke module and a short-stroke module forming part of the second positioner PW. In the case of a stepper (as opposed to a scanner) the support structure MT may be connected to a short-stroke actuator only, or may be fixed. The patterning device (e.g. mask) MA and substrate W may be aligned using mask alignment marks M1, M2 and substrate alignment marks P1, P2. The substrate alignment marks P1, P2 as illustrated occupy dedicated target portions, but may also be located in spaces between the target portions (known as scribe-line alignment marks). Similarly, in situations in which more than one die is provided on the patterning device MA, the mask alignment marks M1, M2 may be located between the dies.

[0034] The depicted lithographic apparatus can be used in at least one of the following modes:

[0035] In a first mode, the so-called step mode, the support structure MT and substrate table WT are kept essentially stationary, while an entire pattern imparted to the radiation beam B is projected onto a target portion C in one go (i.e. a single static exposure). The substrate table WT is then moved 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 that can be imaged in a single static exposure.

[0036] In a second mode, the so-called scan mode, the support structure MT and the substrate table WT are scanned synchronously while a pattern imparted to the radiation beam B is projected onto a target portion C (i.e. a single dynamic exposure). The velocity and direction of the substrate table WT relative to the support structure MT can 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 of the target portion (in the non-scanning direction) in a single dynamic exposure, while the length of the scanning movement determines the height of the target portion (in the scan direction).

[0037] In a third mode, the support structure MT is kept essentially stationary holding the programmable patterning device and the substrate table WT is moved or scanned while projecting a pattern imparted to the radiation beam B onto a target portion C. In this mode, a pulsed radiation source is typically used, and the programmable patterning device is updated as required with each movement of the substrate table WT, or between successive radiation pulses during a scan. This mode of operation is readily applicable to maskless lithography using a programmable patterning device such as a programmable mirror array of the type referred to above.

[0038] Combinations and / or variations of the above described modes of use may be utilized or entirely different modes of use may be utilized.

[0039] As mentioned above, the lithographic apparatus of the present invention may comprise an alignment measurement system for measuring the positions of alignment marks provided on the substrate. By measuring the positions of these alignment marks P1, P2, the position of the substrate W relative to the substrate table WT can be determined.

[0040] This measured position of the substrate W allows the lithographic apparatus to position the substrate W at a desired position relative to the projection system PS and / or patterning device M during the actual projection of the patterned radiation beam onto target portions C of the substrate. In this way, successive projections of the patterned radiation beam onto target portions C of the substrate W can be aligned with each other. The overlay performance, i.e. the alignment of successive projections of the patterned radiation beam onto target portions C of the substrate W, is a key factor in the product quality of devices manufactured using the lithographic apparatus.

[0041] In order to improve product quality, it is generally necessary to improve the overlay performance of the lithographic apparatus. The overlay performance can be improved, for example, by measuring a substantially larger number of alignment marks on the substrate W. In particular, the substrate alignment grid may contain high frequency components of distortion that can be better corrected by measuring a larger number of alignment marks. However, measuring a larger number of alignment marks increases the alignment measurement time, which has a limiting effect on the production performance of the lithographic apparatus.

[0042] Furthermore, during the device measurement process, the substrate undergoes multiple processing steps such as layer deposition, etching, annealing, etc. The impact of these processing steps on the overlay performance of the lithography process is also significant, usually resulting in variations between substrates and / or between stacks of substrates and / or between layers of substrates.

[0043] The invention is based on the insight that a significant part of the alignment measurements can be performed in a separate alignment measurement device. As a result, the production performance of the lithographic apparatus is not so limited by an increasing number of alignment measurements.

[0044] 2 shows a lithography system according to an embodiment of the present invention, comprising a lithography apparatus LA, an alignment measurement apparatus AMA, and a substrate handler SH.

[0045] The lithographic apparatus LA may be the same as or substantially the same as the lithographic apparatus shown in and described with respect to Figure 1. The alignment measurement apparatus AMA is provided as a separate device that can be used to measure multiple alignment marks without directly affecting the production performance of the lithographic apparatus LA.

[0046] A substrate handler SH is provided for transferring substrates W between the alignment measurement apparatus AMA and the lithographic apparatus LA. Further substrate handlers (not shown) may be provided for loading substrates W into the alignment measurement apparatus AMA and for removing substrates W from the lithographic apparatus LA for further processing steps of the substrate W to manufacture a device.

[0047] The substrate handler SH may be any device capable of transferring a substrate W from the alignment measurement apparatus AMA to the lithographic apparatus LA. For example, the substrate handler SH may comprise a gripper for contacting the underside of the substrate, one or more robotic arms, and / or a Bernoulli chuck for holding the substrate on its top surface. Bernoulli chucks are described in WO 2013 / 100203, which is incorporated herein by reference.

[0048] If desired, multiple alignment measurement apparatus AMA may be provided, coupled to the lithographic apparatus LA via one or more substrate handlers SH, so that the productivity of the lithographic apparatus is less dependent on the output of the alignment measurement apparatus AMA. An apparatus comprising one or more alignment measurement apparatus AMA and one or more substrate handlers SH may also be referred to as a metrology apparatus.

[0049] FIG. 3 shows an embodiment of the alignment measurement device AMA in more detail. The alignment measurement device AMA is arranged to measure a number of alignment marks provided on the substrate W. For example, the alignment measurement device AMA includes a substrate alignment system with one or more FIA ​​(Field Image Alignment) sensors. This substrate alignment system may be the same or similar to the previously described alignment measurement system (for measuring the positions of alignment marks provided on the substrate in a lithographic apparatus). Furthermore, the alignment measurement device AMA may measure the positions of alignment marks provided between exposure fields (or between dies) on the substrate as well as overlay marks provided within exposure fields (or within dies) on the substrate. Furthermore, the alignment measurement device AMA may measure the positions of alignment marks and / or overlay marks provided on the substrate as well as asymmetries of the alignment marks and / or overlay marks.

[0050] The alignment measurement apparatus AMA includes a first substrate table (substrate stage) WT1 and a second substrate table (substrate stage) WT2. The first substrate table WT1 and the second substrate table WT2 are each configured to support a substrate W during processing of the substrate W in the alignment measurement apparatus AMA. Note that the two substrates W supported by the first substrate table WT1 and the second substrate table WT2 can each be loaded from a first FOUP, a second FOUP or a third FOUP.

[0051] A first positioning system POS1 is provided for positioning the first substrate table WT1 at a desired position and a second positioning system POS2 is provided for positioning the second substrate table WT2 at a desired position. The first positioning system POS1 and the second positioning system POS2 are supported on a base frame BF. The first positioning system POS1 and the second positioning system POS2 comprise actuator systems and position measurement systems for positioning the substrate W at a desired position with six degrees of freedom.

[0052] The alignment measuring device AMA further comprises a metro frame MF, which is supported on the base frame BF by vibration-isolating supports VIS.

[0053] The alignment measurement apparatus AMA comprises a first station ST1 and a second station ST2 for processing a substrate W. The first and second substrate tables WT1 and WT2 can be moved between the first and second stations ST2, so that a substrate W supported on one of the first and second substrate tables WT1 and WT2 can be processed in the first and / or second stations ST2. It is therefore not necessary to transfer the substrate W between the first and second substrate tables WT1 and WT2 for processing in the first station ST1 and subsequently in the second station ST2.

[0054] A substrate handler (not shown in FIG. 3) may be provided for placing the substrate W onto the first substrate table WT1 and / or the second substrate table WT2 and / or for taking the substrate W from the first substrate table WT1 and / or the second substrate table WT2.

[0055] In the first station ST1, a first alignment sensor AS1 and / or a first level sensor LS1 are provided. The second station ST2 includes a second alignment sensor AS2 and / or a second level sensor LS2. The first alignment sensor AS1 may include, for example, a single Field Image Alignment (FIA) sensor. Alternatively, the first alignment sensor AS1 may include multiple FIA ​​sensors as disclosed in US Patent Application US2009 / 0233234A1, which is incorporated herein by reference. The second alignment sensor AS2 may be configured similarly to the first alignment sensor AS1. Alternatively, the second alignment sensor AS2 may include a different type of alignment sensor than the first alignment sensor AS1. A processing unit PU is provided for receiving and processing sensor signals of the first level sensor LS1, the first alignment sensor AS1, the second level sensor LS2 and / or the second alignment sensor AS2, and may also be arranged to control the first positioning system POS1 and the second positioning system POS2.

[0056] The arrangement with the first station ST1 and the second station ST2 and two or more substrates WT that can be moved between the two stations ST1, ST2 is very suitable for providing further devices or systems that can be used for measuring the position of alignment marks on the substrate W or for carrying out other measurements on the substrate W. Indeed, depending on the needs of a user of the alignment measurement apparatus AMA, this arrangement can be used as desired as a basis for configuring the alignment measurement apparatus AMA to include further devices or systems. If the alignment measurement apparatus AMA comprises several types of sensors, devices or systems, the alignment measurement apparatus AMA may also be referred to as a metrology apparatus. Also, if the alignment measurement apparatus AMA comprises one or more devices for inspecting properties of the substrate, the alignment measurement apparatus AMA may also be referred to as an inspection apparatus.

[0057] The further device or system may for example include a first level sensor LS1, a second level sensor LS2, a first exposure unit EU1, a second exposure unit EU2, a laser ablation unit LAU, and / or an overlay sensor OS in the first station and / or the second station. The further device or system may include further alignment sensors, such as a third alignment sensor AS3 and a fourth alignment sensor AS4. An apparatus in which one or more exposure units are included in the further device or system may be referred to as a lithographic apparatus. An apparatus in which no exposure unit is included in the further device or system may be referred to as a metrology apparatus or an inspection apparatus. In other words, the essential difference between a lithography apparatus and a metrology / inspection apparatus is the presence or absence of an exposure unit, and the lithography apparatus and the metrology / inspection apparatus may comprise similar alignment measurement apparatus(es), substrate tables(es), and substrate handler(s).

[0058] Each further device or system can be connected to the processing unit PU, such that the processing unit PU can receive measurement data from the further device or system and / or the processing unit PU can send instructions to the respective device or system.

[0059] FIG. 3 shows an embodiment of an alignment measurement device AMA that can be configured in this way.

[0060] The alignment measurement device AMA comprises a first level sensor LS1 in the first station ST1 and a second level sensor LS2 in the second station ST2. The level sensors LS1, LS2 are provided for measuring a height map of at least a part of the top surface of the substrate W. Such a height map can be used to more optimally position the substrate W with respect to other measurement devices, such as, for example, a second alignment sensor AS2 in the second station ST2. In addition to or instead of the level sensor, the alignment measurement device AMA may also comprise a film thickness measurement device and / or a spectroscopic reflectance measurement device. For example, the first station ST1 may comprise a film thickness measurement device and the second station ST2 may comprise a spectroscopic reflectance measurement device. Alternatively, only the first alignment sensor AS1 may be provided in the first station ST1 and only the film thickness measurement device / spectroscopic reflectance measurement device may be provided in the second station ST2. When the alignment measurement device AMA includes one or more alignment sensors AS and a film thickness measurement device / spectral reflectance measurement device, the alignment measurement device AMA may be referred to as a measurement device. The measurement device may include one or more alignment sensors AS, one or more level sensors, one or more film thickness measurement devices, and / or one or more spectral reflectance measurement devices. The film thickness measurement device may be a film thickness measurement device capable of measuring the film thickness distribution over the entire substrate surface at high speed, as disclosed in, for example, JP 2010-025575 A, which is incorporated herein by reference. Instead of the spectral reflectance measurement device, for example, a spectral reflectance prediction device may be used, as disclosed in, for example, JP 2006-084333 A, which is incorporated herein by reference. The film thickness measurement device may also include a spectral reflectance measurement device, as disclosed in, for example, JP 2005-265655 A, which is incorporated herein by reference.

[0061] Depending on the desired accuracy of the height map of the substrate W, one or more scans can be performed on the top surface of each substrate W. The top surface can be completely scanned by the first level sensor LS1 in order to obtain a complete height map of the substrate W. In other embodiments, the top surface of the substrate W is only partially scanned on a relevant portion of the substrate W. The height level can for example be determined only for a small area where the alignment marks are provided in order to optimize the vertical and / or tilted position of the substrate W relative to the second alignment sensor AS2 during the measurement of each alignment mark by the second alignment sensor AS2. Such optimization of the position of the alignment marks relative to the second alignment sensor AS2 will improve the measurement performance of the second alignment sensor AS2.

[0062] Additionally or alternatively, the alignment measurement arrangement AMA may comprise a laser ablation unit LAU in the first station ST1. This laser ablation unit LAU may be used to locally cut a part of a resist layer provided on the substrate W for the lithographic process, in particular at the location of the alignment marks. Some types of alignment sensors have a reduced alignment measurement performance when they have to perform measurements through the resist layer. Also, some types of resist layers used during device manufacturing are opaque. Opaque layers are often used, for example, during the manufacturing of 3D cell stacking devices. These opaque layers prevent the alignment sensors AS1, AS2, AS3, AS4 from measuring the position of the alignment marks through the opaque layer above the alignment marks.

[0063] By locally removing the resist layer with the laser ablation unit LAU, the alignment sensors AS1, AS2, AS3, AS4 can access the alignment marks without the measurement beam having to pass through the resist layer of the substrate W. The laser ablation unit LAU therefore makes it possible to improve the measurement quality of the position measurements of the alignment marks or to measure alignment marks which have previously been coated with an opaque layer.

[0064] Additionally or alternatively, a first exposure unit EU1 and a second exposure unit EU2 may be provided in the first station ST1 and the second station ST2, respectively. The first exposure unit EU1 and the second exposure unit EU2 can be used to project further alignment marks onto the substrate W. In some applications it is desirable to provide new alignment marks on the substrate W, for example because the alignment marks tend to deteriorate during lithographic process steps or because the alignment marks are covered by an opaque layer and it is undesirable to locally cut a layer at the location of the alignment marks, for example using a laser ablation unit LAU. The exposure units EU1, EU2 can then be used to print the new alignment marks on the substrate W.

[0065] It will be appreciated that the first exposure unit EU1 and the first alignment sensor AS1 can be used simultaneously, such that while the exposure unit EU projects a new alignment mark onto the substrate W, at least one existing alignment mark can be measured by the first alignment sensor AS1 and the exact location of the new alignment mark relative to the existing alignment marks can be determined. Similarly, the second exposure unit EU2 and the second alignment sensor AS2 can also be used simultaneously in the second station ST2.

[0066] The first exposure unit EU1 and / or the second exposure unit EU2 may also be used to project a beam onto a particular part of the resist layer in order to locally remove this part of the resist layer. In particular, the first exposure unit EU1 and / or the second exposure unit EU2 may be used to remove a part of the resist layer provided above one or more alignment marks of the substrate W, corresponding to the use of a laser ablation unit LAU as described below.

[0067] The first station ST1 also comprises a third alignment sensor AS3. The second station ST2 comprises a fourth alignment sensor AS4 and an overlay sensor OS. The third and fourth alignment sensors AS3, AS4 may be different types of alignment measurement devices from the first alignment sensor AS1 and the second alignment sensor AS2.

[0068] The provision of the third alignment sensor AS3 and the fourth alignment sensor AS4 provides even more flexibility in terms of the alignment measurements that can be performed by the alignment measurement apparatus AMA. For example, depending on the success of previous alignment measurements and / or knowledge of the particular substrate W to be measured, it may be determined which alignment sensors in the first and / or second stations ST1, ST2 are best suited for use in measuring the alignment of alignment marks on the substrate W.

[0069] Furthermore, the first alignment sensor AS1, the second alignment sensor AS2, the third alignment sensor AS3, and the fourth alignment sensor AS4 are capable of measuring different types of alignment marks on the same substrate W, which can improve the quality of the alignment measurement of the substrate W. Furthermore, these alignment sensors may measure not only the positions of alignment marks provided between exposure fields (or between dies) on the substrate, but also overlay marks provided within exposure fields (or within dies) on the substrate.

[0070] An overlay sensor OS is provided for measuring the overlay between patterns projected onto the substrate W. The overlay sensor OS can be used, for example, to measure the overlay performance of a lithography system. For example, the overlay sensor OS may measure overlay marks on the substrate. The alignment sensor and / or the overlay sensor OS may also measure the asymmetry of the alignment marks and / or the overlay marks. For measuring the asymmetry of these marks, for example, the apparatus and measurement method as disclosed in JP 2006-060214 A and WO 2014 / 026819 A, which are incorporated herein by reference, or an apparatus and measurement method similar thereto may be used.

[0071] The alignment measurement apparatus AMA provides a great deal of flexibility for alignment measurements of substrates W. It allows the user to adapt the alignment measurements to specific properties of the stack of substrates W to be processed, such as layer thicknesses, material properties, and target shapes. These stack properties generally vary depending on the semiconductor device type, but they may also vary from substrate to substrate and from substrate to substrate. As the lithographic apparatus can be used for different device types, the flexible alignment measurement apparatus AMA can be applied to efficiently deal with all these different stacks.

[0072] Moreover, the alignment measurement device AMA provides a first station ST1 and a second station ST2, and two substrates can be processed simultaneously. This allows, for example, the measurement capacity to be substantially increased, for example by a factor of two, when the first alignment sensor AS1 and the second alignment sensor AS2 are simply arranged in the respective stations and operated in the same manner. Also, when different types of measurement devices (or sensor systems) are arranged in the first station ST1 and the second station ST2, for example, when the first alignment sensor AS1 and the film thickness measurement device / spectral reflectance measurement device are arranged in the respective stations, not only can two substrates be processed simultaneously, but also the operation method of the alignment measurement device AMA can be optimized according to the difference in the required measurement time. For example, if the time required for the first alignment sensor AS1 located in the first station ST1 to complete alignment measurement of one substrate is three times the time required for the film thickness measurement device located in the second station ST2 to measure the film thickness distribution across the entire substrate surface (assuming that the time it takes the substrate handler to exchange substrates is negligible), then approximately three substrates could be processed in the second station ST2 while one substrate is being processed in the first station ST1.

[0073] In an embodiment of a method using the alignment measurement apparatus, alignment measurements relating to the position of an alignment mark on the substrate W can be performed at both the first station ST1 and the second station ST2, whereby the substrate W continues to be supported on one of the first substrate table WT1 and the second substrate table WT2.

[0074] Thereby, the result of an alignment measurement with the first alignment sensor AS1 in the first station ST1 can be used as input for an alignment measurement with the second alignment sensor AS2 in the second station.

[0075] For example, in the first station ST1 the positions of a first number of alignment marks on the substrate W may be measured by a first alignment sensor AS1. In the second station ST2 the positions of a second number of alignment marks on the substrate W may be measured by a second alignment sensor AS2, whereby the second number of alignment marks, i.e. quantity and / or location, are measured based on the outcome of the alignment measurement in the first station ST1. The selection of the second number of alignment marks may for example be a consequence of a measurement quality determined for the alignment measurement using the first alignment sensor AS1.

[0076] If, based on measurements of the first alignment sensor AS1, certain areas of the substrate W are likely to require more, or a relatively larger number of alignment measurements to improve the measurement quality of the alignment marks on the substrate W, a second number of alignment marks can be selected specifically within, or concentrated in, these areas in order to obtain position measurements of a larger number of alignment marks within these areas.

[0077] In one embodiment, the number of alignment marks measured using the first alignment sensor AS1 (the first number) is substantially less than the number of alignment marks measured using the second alignment sensor AS2 (the second number). The measurements using the first alignment sensor AS1 will typically be used to optimize the measurements using the second alignment sensor AS2.

[0078] The number of alignment marks measured with the second alignment sensor AS2 (the second number) may be 200 or more per substrate, and preferably 300 or more per substrate. Measuring this relatively large number of alignment marks substantially improves the measurement quality of the alignment marks, which has a significant positive impact on the overlay performance of the lithographic apparatus LA.

[0079] It will be appreciated that the first number of alignment marks and the second number of alignment marks may partially or completely overlap, i.e. the alignment marks measured using the first alignment sensor AS1 and the alignment marks measured using the second alignment sensor AS2 may partially or completely overlap.

[0080] Up to this point, an embodiment of the alignment measurement apparatus AMA as shown in FIG. 3 has been described. It will be clear to the skilled person that many other configurations are also possible. For example, in the first station ST1, the laser ablation unit LAU, the first exposure unit EU1 and / or the third alignment sensor AS3 may be omitted, and in the second station ST2, the second exposure unit EU2, the fourth alignment sensor AS4 and / or the overlay sensor OS may be omitted. Correspondingly, an overlay sensor OS can be added in the first station ST1 and / or a laser ablation unit LAU can be added in the second station ST2. Also, the overlay sensor OS may be omitted if the first alignment sensor AS1, the second alignment sensor AS2, the third alignment sensor AS3 and / or the fourth alignment sensor AS4 measure the position of an alignment mark on the substrate as well as an overlay mark on the substrate.

[0081] Figure 4 shows a first embodiment of a lithographic apparatus according to an aspect of the present invention. In particular, Figure 4 shows a top view of a substrate table arrangement (substrate stage and handler system) applied in a lithographic apparatus according to an embodiment of the present invention. The substrate stage and handler system according to an embodiment of the present invention may be applied in a metrology or inspection apparatus.

[0082] The substrate table arrangement (substrate stage handler system) comprises a first substrate table WT1, a second substrate table WT2 and a third substrate table WT3, each constructed to support a substrate W. The first substrate table WT1, the second substrate table WT2 and the third substrate table WT3 are movably supported by a substrate table positioning system. The substrate table positioning system comprises a first positioning module PM1 movable in a planar motion range PAM. Correspondingly, the second substrate table WT2 comprises a second positioning module PM2 movable in a planar motion range PAM and the third substrate table WT3 comprises a third positioning module PM3 also movable in a planar motion range PAM.

[0083] The planar motion region PAM may for example be defined by a plane formed by the arrays of permanent magnets. Each of the first positioning module PM1, the second positioning module PM2 and the third positioning module PM3 comprises one or more actuation coils which, when energized by a controller, are capable of moving the respective positioning module PM1, PM2, PM3 to a desired position in the planar motion region PAM relative to the arrays of permanent magnets. Each of the first positioning module PM1, the second positioning module PM2 and the third positioning module PM3 may comprise a fine positioning device for positioning the first substrate table WT1, the second substrate table WT2 and the third substrate table WT3, respectively, to a desired position with high accuracy.

[0084] A position measurement system may be provided to measure the positions of the first substrate table WT1, the second substrate table WT2 and the third substrate table WT3 with high accuracy, preferably in six degrees of freedom. In an embodiment, the position measurement system comprises one or more grid plates arranged on at least a part of the planar motion area PAM and an encoder-type sensor mounted on each of the first substrate table WT1, the second substrate table WT2 and the third substrate table WT3 to determine the position of the respective substrate table WT1, WT2, WT3 relative to the one or more grid plates. Alternatively, one or more grid plates may be provided on the top, side and / or bottom surface of each of the substrate tables WT1, WT2, WT3. In this case, multiple encoder-type sensors may be arranged on the metro frame MF, the base frame BF and / or at any position around the working area of ​​each substrate table. Additionally or alternatively, the position measurement system may comprise an interferometer system. In this case, one or more mirrors may be provided on the top, side and / or bottom surface of each of the substrate tables.

[0085] The first substrate table WT1 needs to be connected to a fixed part of the lithographic apparatus in order to supply any necessary items or signals to the first substrate table WT1. For example, there may be electrical connections for energizing, e.g. for energizing an actuation coil, a vacuum conduit to facilitate vacuum clamping, one or more cooling fluid conduits for providing a cooling fluid, and / or control connections for providing control signals to the first substrate table WT1. It may also be necessary to transfer items or signals, such as sensor signals or a cooling fluid used to cool the first substrate table WT1, from the first substrate table WT1 to the fixed part of the lithographic apparatus.

[0086] In the embodiment described above, these connections between the first substrate table WT1 and a fixed part of the lithographic apparatus, or at least parts thereof, are provided in a first cable connection CC1. The first cable CC1 is provided between the first substrate table WT1 and a first cable connection support CCS1. The different connections in the first cable connection CC1 are provided as a row of connections that are relatively stiff in the x-direction and relatively flexible in other directions, in particular the y-direction. Such cable connections are also indicated as cable shreps. It will be appreciated that the term cable connection is used herein for any mechanical connection between the respective substrate table and other parts of the lithographic apparatus for the transfer of items such as fluids, electrical energy, air and / or signals between the respective substrate table and other parts of the lithographic apparatus.

[0087] Since the first cable connection CC1 is relatively stiff in the x-direction, the first cable connection support CCS1 is movably supported on a first linear guide LG1 extending in the x-direction on a first side of the planar movement area PAM. Since the first cable connection support CCS1 moves relative to the first linear guide LG1 to follow movements of the first substrate table WT1 in the x-direction, the first cable connection CC1 does not significantly adversely affect the positioning of the first substrate table WT1. Further connections from the first cable connection support CCS1 are provided to other parts of the lithographic apparatus, for example to an energy source, a vacuum source, a coolant source and / or a controller.

[0088] The first cable connection support CCS1 may be guided on the first linear guide LG1 in any suitable manner. For example, there may be a mechanical, fluid or gas bearing between the first cable connection support CCS1 and the first linear guide LG1. For example, an air bearing may be used. Preferably, the first linear guide LG1 is formed as a linear magnetic support guide.

[0089] The second substrate table WT2 is connected to a second cable connection support CCS2 by means of a second cable connection CC2. The second cable connection support CCS2 is movably guided on a second linear guide LG2. The second linear guide LG2 is arranged on a second side of the planar movement area PAM, opposite to a first side along which the first linear guide LG1 extends along the planar movement area PAM. The first linear guide LG1 and the second linear guide LG2 both extend in the same direction, for example the x-direction in the embodiment of FIG. 4.

[0090] The third substrate table WT3 is connected to the third cable connection support CCS3 by means of a third cable connection CC3. The third cable connection support CCS3 is movably guided by the first linear guide LG1. As a result of the first cable connection support CCS1 and the third cable connection support CCS3 both being guided on the first linear guide LG1, the first substrate table WT1 and the third substrate table WT3 cannot swap positions in the x-direction. In contrast, the second substrate table WT2, which is connected to the second cable connection support CCS2 guided by the second linear guide LG2 by means of the second cable connection CC2, can swap positions in the x-direction with both the first substrate table WT1 and the third substrate table WT3. This means that the second substrate table WT2 can be positioned to the right of the third substrate table WT3 as shown in FIG. 4, but also between the first substrate table WT1 and the third substrate table WT3 and to the left of the first substrate table WT1.

[0091] To be able to load a substrate W onto both the first substrate table WT1 and the third substrate table WT3, a first substrate handler SH1 is arranged on a third side of the planar movement zone PAM for loading and / or unloading a substrate W onto the first substrate table WT1, and a second substrate handler SH2 is arranged on a fourth side of the planar movement zone PAM opposite the third side for loading and / or unloading a substrate W onto the third substrate table WT3. Both the first substrate handler SH1 and the second substrate handler SH2 can be used to load and / or unload a substrate onto the second substrate table WT2.

[0092] A first loading station LST1 is arranged adjacent to the first substrate handler SH1, and a second loading station LST2 is arranged adjacent to the second substrate handler SH2. The first substrate table WT1 and the second substrate table WT2 can be arranged in the first loading station LST1 when the first substrate handler SH1 loads or unloads a substrate W from the first substrate table WT1 or the second substrate table WT2. Correspondingly, the second substrate table WT2 and the third substrate table WT3 can be arranged in the second loading station LST2 when the second substrate handler SH2 loads or unloads a substrate W onto the second substrate table WT2 or the third substrate table WT3.

[0093] Instead of the first substrate handler SH1 and the second substrate handler SH2, a single long arm substrate handler can be provided on one side of the planar movement area PAM, which is capable of loading and / or unloading substrates W from this one side on each of the first substrate table WT1, the second substrate table WT2 and the third substrate table WT3.

[0094] The substrate table positioning system is configured such that the first substrate table WT1, the second substrate table WT2 and the third substrate table WT3 are moveable between at least the alignment level measuring station ALST and the exposure station EST.

[0095] Figure 5 shows the alignment level measuring station ALST and the exposure station EST in more detail. In the alignment level measuring station ALST an alignment sensor AS is provided for measuring the position of several alignment marks on the substrate and a level sensor LS is provided for measuring a height map of the top surface of the substrate W. In the exposure station EST an exposure unit is provided for transferring a pattern from the patterning device MA to the substrate W. The exposure unit comprises a light source SO, an illumination system IL, a patterning device support MT for supporting the patterning device and a projection system PS for projecting a patterned radiation beam onto the substrate W as described with reference to Figure 1.

[0096] It will be appreciated that the alignment and level measuring station ALST may comprise a number of alignment sensors and / or level sensors, for example alignment sensors of different types, which may be used by a user of the lithographic apparatus as desired.

[0097] The alignment level measuring station ALST as well as the exposure station EST are mutually aligned, i.e. positioned next to each other in the x-direction. The alignment direction of the alignment level measuring station ALST as well as the exposure station EST is the same as the guiding direction of the connecting cables of the first linear guide LG1 and the second linear guide LG2.

[0098] The advantage of the substrate table configuration as shown in Figure 4 is that the additional substrate table WT3 allows more time for loading and / or unloading substrates W onto the substrate tables WT1, WT2, WT3 and / or for alignment and / or level measurements in the alignment and level measuring station ALST.

[0099] By allowing a longer time for loading and unloading the substrate W, distortion and wear of the grids of the substrate tables WT1, WT2, WT3 caused by fast wafer loading can be reduced.

[0100] A longer alignment measurement time allows an increase in the number of alignment marks that can be measured in the alignment level measuring station ALST, which in turn allows a higher (inter-field and intra-field) grid density of alignment marks to be measured on the substrate W, thus improving the overlay accuracy during the actual lithographic exposure process in the exposure station EST.

[0101] FIG. 6 shows an alternative embodiment of a substrate stage handler system according to an embodiment of the present invention, which can be applied to a lithographic apparatus and a metrology apparatus. In the embodiment of FIG. 6, the lithographic apparatus further comprises a second alignment level measuring station ALST2 in addition to the embodiment of FIG. 4. In the second alignment level measuring station ALST2, an alignment sensor AS for measuring the positions of several alignment marks on the substrate and a level sensor LS for measuring a height map of the upper surface of the substrate are provided. The alignment sensor AS and the level sensor LS in the alignment level measuring station ALST and the second alignment level measuring station ALST2 may be substantially the same. The alignment level measuring station ALST, the exposure station EST and the second alignment level measuring station ALST2 are aligned in the x-direction, i.e. are arranged next to each other in the x-direction. If this substrate stage handler system is applied to a metrology apparatus, a third alignment level measuring station ALST3 may be arranged instead of the exposure station EST.

[0102] The alignment level measuring station ALST as well as the second alignment level measuring station ALST2 allow for simultaneous measurement of alignment marks and / or levels on the top surfaces of two substrates W. For example, as shown in FIG. 6, a substrate W supported on a first substrate table WT1 is placed in the alignment level measuring station ALST and a substrate W supported on a third substrate table WT3 is placed in the second alignment level measuring station ALST2. At the same time, a substrate W supported on a second substrate table WT2 is processed in an exposure station EST. Typically, the first substrate table WT1 will be used in combination with the alignment level measuring station ALST and the third substrate table WT3 will be used in combination with the second alignment level measuring station ALST2. The second substrate table WT2 can be used both in combination with the alignment level measuring station ALST and in combination with the second alignment level measuring station ALST2.

[0103] An advantage of the substrate table configuration as shown in Figure 6 is that by using the second alignment and level measuring station ALST2, the time for loading and / or unloading a substrate W onto the substrate tables WT1, WT2, WT3 and / or the time for alignment and level measurements at the alignment and level measuring station ALST can be even longer.

[0104] FIG. 7 shows another alternative embodiment of a substrate stage handler system applicable to a lithographic apparatus and a metrology apparatus according to an embodiment of the present invention. In the embodiment of FIG. 7, the lithographic apparatus further comprises an additional alignment measurement station AAST, which comprises an alignment sensor system for measuring the positions of several alignment marks on a substrate W supported by one of the first substrate table WT1, the second substrate table WT2 and the third substrate table WT3. The type of alignment sensor provided and used in the additional alignment measurement station AAST may be different from the alignment sensor AS of the alignment level measurement station ALST and the second alignment level measurement station ALST2. In an alternative embodiment, the type of alignment sensor in the additional alignment measurement station AAST may be the same as the alignment sensor AS of the alignment level measurement station ALST and the second alignment level measurement station ALST2, and a combination of the same alignment sensor and a different alignment sensor may also be provided in the additional alignment measurement station AAST.

[0105] The alignment level measuring station ALST, the second alignment level measuring station ALST2 as well as the additional alignment measuring station AAST can be used for the alignment measuring device AMA shown in Fig. 3 as described above. The alignment level measuring station ALST as well as the second alignment level measuring station ALST2 can be configured as a first station of the alignment measuring device AMA and the additional alignment measuring station AAST can be configured as a second station of the alignment measuring device AMA, with the difference that the alignment level measuring station ALST, the second alignment level measuring station ALST2 as well as the additional alignment measuring station AAST are not arranged in a separate alignment measuring device AMA but in the lithographic apparatus. Any other configuration of the alignment level measuring station ALST, the second alignment level measuring station ALST2 as well as the additional alignment measuring station AAST is also applicable.

[0106] Figure 8 shows another alternative embodiment of a substrate stage and handler system applicable in a lithographic and metrology apparatus according to aspects of the present invention. In the embodiment of Figure 8, a fourth substrate table WT4 is constructed to support a substrate W. The fourth substrate table WT4 is supported on a fourth positioning module PM4 which is movable in a planar motion range PAM.

[0107] A fourth cable connection CC4 is provided between the fourth substrate table WT4 and the fourth cable connection support CCS4. The fourth cable connection support CCS4 is supported on the second linear guide LG2. A first substrate handler SH1 is provided for loading and unloading the substrate W on the first substrate table WT1 and the second substrate table WT2. A second substrate handler SH2 is provided for loading and unloading the substrate W on the third substrate table WT3 and the fourth substrate table WT4. Since the second cable connection support CCS2 and the fourth cable connection support CCS4 are both guided by the second linear guide LG2, it is clear that the second substrate table WT2 and the fourth substrate table WT4 cannot swap positions in the x-direction. However, the second substrate table WT2 and the fourth substrate table WT4 can be positioned at any position in the x-direction with respect to the first substrate table WT1 and the third substrate table WT3.

[0108] In the planar movement area PAM of the substrates WT1, WT2, WT3, WT4, an alignment level measuring station ALST, an additional alignment measuring station AAST and an exposure station EST are arranged. The alignment level measuring station ALST, the additional alignment measuring station AAST and the exposure station EST are aligned in the x-direction, in particular parallel to the cable connection guiding direction of the first linear guide LG1 and the second linear guide LG2. The alignment level measuring station ALST can be configured as a first station of the alignment measuring device AMA, whereas the additional alignment measuring station AAST can be configured as a second station of the alignment measuring device AMA. Any other configuration of the alignment level measuring station ALST as well as the additional alignment measuring station AAST is also applicable. If this substrate stage handler system is applied in a metrology device, instead of the exposure station EST, a third alignment level measuring station ALST3 may be arranged.

[0109] The provision of four substrate tables WT1, WT2, WT3, WT4 results in much longer times for loading / unloading a substrate W and for performing alignment and level measurements.

[0110] Also, in all the embodiments of Figures 4 to 8, the substrate W remains on the same substrate table WT1, WT2, WT3, WT4 during level measurements on the substrate W, alignment measurements and exposure of the patterned radiation beam.

[0111] Between the two cable connection supports guided on a single linear guide, a further cable connection support may be provided for supporting a cable connection to a further positioning module, which may not be configured to support a substrate table, since it cannot be placed next to the substrate handlers SH1, SH2, but may be configured for example to perform metrology and / or calibration processes.

[0112] However, in an embodiment the further positioning module may also comprise a substrate table constructed to support a substrate W. In that case at least one substrate handler should be provided which is able to load and unload a substrate onto the substrate table of the further positioning module. Such a substrate loader may for example be a long arm substrate handler which is able to load a substrate over a relatively long distance from a base of the substrate handler, e.g. via the first substrate table, to the substrate table of the further positioning module.

[0113] Above, with respect to Figures 4 to 8, different combinations of three or more substrate tables and multiple process stations including exposure stations and / or alignment level measurement stations have been described. Further stations, such as alignment level measurement stations, may be provided to increase the available time for loading / unloading substrates onto the respective substrate tables and for performing alignment level measurements. Thus, by applying the above substrate stage handler system to a lithographic apparatus, the overlay performance of the lithographic process may be improved. It will be apparent that other substrate table configurations may also be provided.

[0114] An important advantage of the embodiment of Figures 4 to 8 when the above substrate stage / handler system is applied to a lithography apparatus is that the substrate W remains supported on each of the substrate tables WT1, WT2, WT3, WT4 during alignment and level measurement and subsequent exposure to the patterned radiation beam. Also, an advantage of the above substrate stage / handler system when applied to a metrology apparatus (or inspection apparatus) is that the number (or types) of measurement devices / inspection devices, the number of substrate tables, and the number of substrate handlers do not need to be the same, and multiple types of characteristics of the substrate can be efficiently measured (inspected) by optimizing the combination of these numbers. When the metrology apparatus includes different types of measurement devices (inspection devices, sensor systems), for example, an alignment sensor and a level sensor (or a film thickness measurement apparatus / spectral reflectance measurement apparatus), the number of measurement devices / inspection devices, the number of substrate tables, the number of substrate handlers, and the operation method of the metrology apparatus can be further optimized by considering the difference in the time required for each measurement device to complete the measurement of one substrate. In other words, by providing a single unified measurement (inspection) apparatus capable of measuring (inspecting) multiple types of characteristics of a substrate, and optimizing the number of measurement devices / inspection devices, the number of substrate tables, the number of substrate handlers, and the operation method of the measurement apparatus, the throughput performance and / or economy of the measurement apparatus can be improved compared to using multiple measurement and inspection apparatus.

[0115] Although particular reference is made herein to the use of lithographic apparatus in the manufacture of ICs, it should be understood that the lithographic apparatus described herein has 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, and the like. In light of these alternative applications, those skilled in the art will recognize that the use of the terms "wafer" or "die" herein may be considered synonymous with the more general terms "substrate" or "target portion", respectively. The substrates described herein may be processed, before or after exposure, for example in a track (a tool that typically applies a layer of resist to the substrate and develops the exposed resist), a metrology tool, and / or an inspection tool. Where appropriate, the disclosure herein may be applied to these and other substrate processing tools. Furthermore, the substrate may be processed multiple times, for example to produce a multi-layer IC, and thus the term substrate as used herein may also refer to a substrate that already includes multiple processed layers.

[0116] Although particular reference has been made to the use of embodiments of the invention in the field of optical lithography, it should be understood that the invention may also be used in other fields, for example imprint lithography, depending on the context, and is not limited to optical lithography. In imprint lithography, a topography in a patterning device defines the pattern created on a substrate. The topography of the patterning device is imprinted into a layer of resist supplied to the substrate and the resist is cured by applying electromagnetic radiation, heat, pressure or a combination thereof. The patterning device is then removed from the resist leaving a pattern in it when the resist is hardened.

[0117] While specific embodiments of the invention have been described above, it will be appreciated that the invention may be practiced otherwise than as described. For example, embodiments of the invention may take the form of a computer program comprising one or more sequences of machine-readable instructions that describe the methods as disclosed above, or a data storage medium having such a computer program stored therein (e.g., a semiconductor memory, a magnetic or optical disk).

[0118] The above description is illustrative and not restrictive. Thus, it will be apparent to one skilled in the art that modifications of the invention as described may be made without departing from the scope of the claims.

Claims

1. 1. A metrology apparatus for measuring a first substrate and a second substrate before the first substrate and the second substrate are sent to a lithography apparatus for exposure, comprising: a first substrate stage configured to hold the first substrate or the second substrate; a second substrate stage configured to hold the other of the first substrate or the second substrate; a first measurement apparatus comprising an alignment sensor system for measuring positions of several alignment marks on a substrate supported by the first substrate stage and / or the second substrate stage; a second measurement device having at least one of a film thickness measurement device, a spectroscopic reflectance measurement device, a level sensor configured to perform height measurements, and an alignment sensor system for measuring positions of several alignment marks on a substrate supported by the first substrate stage and / or the second substrate stage; a processing system configured to control the metrology tools to cause the first measurement tool and the second measurement tool to simultaneously measure the first substrate and the second substrate, respectively; A metrology apparatus, wherein the first substrate stage and / or the second substrate stage are movable from measurement of a substrate by the first measurement apparatus to measurement of the substrate by the second measurement apparatus, or vice versa.

2. The metrology device of claim 1 , wherein the first measurement device comprises a level sensor configured to make a height measurement.

3. The metrology device of claim 1 further comprising a laser ablation unit.

4. 1. An alignment measurement apparatus for measuring the position of an alignment mark on a substrate before the substrate is sent to a lithography apparatus for exposure, comprising: a first station comprising a first alignment sensor system for measuring positions of a first number of alignment marks on the substrate; a second station comprising a second alignment sensor system for measuring positions of a second number of alignment marks on the substrate or another substrate, a central portion of the second station being located away from a central portion of the first station; a movable substrate table constructed to hold the substrate, the movable substrate table being arranged to move to the first station and to the second station; An alignment measurement device comprising:

5. The measurement apparatus according to claim 4 , further comprising a film thickness measurement device or a spectral reflectance measurement device.

6. The measurement device of claim 4 , wherein the first station comprises a level sensor configured to make a height measurement.

7. The measurement device of claim 4 , wherein the second station comprises a level sensor configured to make a height measurement.

8. The measurement apparatus of claim 4 , wherein the first alignment sensor system is of a different type than the second alignment sensor system.

9. 5. The measurement apparatus of claim 4, wherein the structure of the first station, the second station and / or both are designed to selectively add an alignment measurement device, a level sensor, a film thickness measurement device, a spectroscopic reflectance measurement device, a laser ablation unit, and / or an overlay sensor.

10. The measurement device of claim 4 further comprising a laser ablation unit.

11. 1. An alignment measurement apparatus for measuring the position of an alignment mark on a substrate before the substrate is sent to a lithography apparatus for exposure, comprising: a first alignment sensor system for measuring the position of an alignment mark on the substrate; a second alignment sensor system for measuring a position of an alignment mark on the substrate or a further substrate, the second alignment sensor system being of a different type to the first alignment sensor system; a movable substrate table constructed to hold the substrate; and and an additional movable substrate table constructed to hold said further substrate, An alignment measurement apparatus, wherein the movable substrate table and / or the further movable substrate table are movable from measuring a substrate by the first alignment sensor system to measuring the substrate by the second alignment sensor system or vice versa.

12. The measurement device of claim 11 further comprising a level sensor configured to provide a height measurement.

13. The measurement device of claim 11 further comprising a laser ablation unit.

14. 12. The measurement apparatus of claim 11, further comprising a processing system configured to control the measurement apparatus to cause the first alignment sensor system and the second alignment sensor system to simultaneously measure the substrate and another substrate, respectively.

15. The measurement apparatus according to claim 11 , further comprising a film thickness measurement device or a spectral reflectance measurement device.

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