TWI448826B - Method of loading a substrate on a substrate table, device manufacturing method, computer program, data carrier and apparatus - Google Patents

Description

Method for mounting substrate on substrate table, device manufacturing method, computer program, data carrier and device

The present invention relates to a method of loading a first object onto a second object during lithography, a device manufacturing method, a computer program, and a data carrier. The invention further relates to a device constructed to hold a first article on a second article in a lithography apparatus.

A lithography apparatus is a machine that applies a desired pattern onto a substrate, typically applied to a target portion of the substrate. The lithography apparatus can be used, for example, in the manufacture of integrated circuits (ICs). In this case, a patterned device (which may alternatively be referred to as a reticle or main reticle) may be used to create a circuit pattern to be formed on individual layers of the IC. This pattern can be transferred onto a target portion (eg, including a portion of a die, a die, or a plurality of dies) on a substrate (eg, a germanium wafer). Transfer of the pattern is typically via imaging onto a layer of radiation-sensitive material (resist) provided on the substrate. In general, a single substrate will contain a network of sequentially patterned adjacent target portions. Known lithography apparatus includes a so-called stepper in which each target portion is illuminated by exposing the entire pattern to a target portion at a time; and a so-called scanner in which a direction is given in a "scan" direction Each of the target portions is illuminated by scanning the substrate simultaneously via the radiation beam while scanning the substrate in parallel or anti-parallel to this direction. It is also possible to transfer the pattern from the patterned device to the substrate by imprinting the pattern onto the substrate.

When the substrate is positioned on the substrate stage, thermal stresses and mechanical stresses can be induced in the substrate, which can negatively affect quality pattern transfer. Therefore, the goal is Reduce stress.

According to one aspect, a method of loading a first item onto a second item during lithography is provided, wherein the method comprises: a) loading the first item onto the second item, b) waiting for a predetermined time interval, c) performing a slack action for removing stress experienced by at least one of the group comprising the first item and the second item.

In accordance with an aspect of the present invention, a device fabrication method is provided that includes transferring a pattern from a patterned device onto a substrate, wherein the device fabrication method includes performing the method.

In accordance with another aspect of the present invention, a computer program is provided that is configured to perform a method when loaded on a computer configuration.

Also, a data carrier is provided that includes a computer program.

According to another aspect, a device is provided for constructing a first article on a second object in a lithography apparatus, wherein the device includes a loading member for loading the first object on the second object, And a relaxation member for performing a relaxation action for removing stress experienced by at least one component comprising the first article and the second article, wherein the device is configured to be between loading the first object and performing the slack action Wait for a predetermined time interval.

The invention will now be described by way of example only with the accompanying schematic drawings Embodiments, in the drawings, corresponding reference numerals indicate corresponding parts.

FIG. 1 schematically depicts a lithography apparatus in accordance with an embodiment of the present invention. The apparatus comprises: - a lighting system (illuminator) IL configured to adjust a radiation beam B (eg, UV radiation or EUV radiation); a support structure (eg, a reticle stage) MT configured to support patterning A device (eg, a reticle) MA and coupled to a first locator PM, the first locator PM configured to accurately position the patterned device according to certain parameters; a substrate table (eg, wafer table) WT, It is constructed to hold a substrate (eg, a resist-coated wafer) and is coupled to a second locator PW that is configured to accurately position the substrate according to certain parameters; and a projection system (eg, a refractive projection lens system) PS configured to project a pattern imparted by the patterned device MA to the radiation beam B onto a target portion C (eg, comprising one or more dies) of the substrate W.

It should be understood that other lithographic devices exist or are contemplated to include other components. For example, the stepper or maskless exposure tool may not have the first positioner PM.

The illumination system can include various types of optical components for guiding, shaping, or controlling radiation, such as refractive, reflective, magnetic, electromagnetic, electrostatic, or other types of optical components, or any combination thereof.

The support structure supports (ie, carries) the patterned device. The support structure holds the patterned device in a manner that depends on the orientation of the patterned device, the design of the lithographic device, and other conditions, such as whether the patterned device is held in a vacuum environment. The support structure can hold the patterned device using mechanical, vacuum, electrostatic or other clamping techniques. The support structure can be, for example, a frame or a table. It can be fixed or movable as needed. The support structure ensures that the patterned device, for example, is in a desired position relative to the projection system. Any use of the term "main reticle" or "reticle" herein is considered synonymous with the more general term "patterned device."

The term "patterned device" as used herein shall be interpreted broadly to refer to any device that can be used to impart a pattern to a radiation beam in a cross-section of a radiation beam to form a pattern in a target portion of the substrate. It should be noted that, for example, if the pattern imparted to the radiation beam includes a phase shifting feature or a so-called auxiliary feature, the pattern may not exactly correspond to the desired pattern in the target portion of the substrate. Typically, the pattern imparted to the radiation beam will correspond to a particular functional layer in a device (such as an integrated circuit) formed in the target portion.

The patterned device can be transmissive or reflective. Examples of patterned devices include photomasks, programmable mirror arrays, and programmable LCD panels. Photomasks are well known in lithography and include reticle types such as binary alternating phase shift and attenuated phase shift, as well as various hybrid reticle types. One example of a programmable mirror array uses a matrix configuration of small mirrors, each of which can be individually tilted to reflect the incident radiation beam in different directions. The tilted mirror imparts a pattern to the radiation beam reflected by the mirror matrix.

The term "projection system" as used herein shall be interpreted broadly to encompass any type of projection system, including refractive, reflective, catadioptric, magnetic, electromagnetic, and electrostatic optical systems, or any combination thereof, suitable for the exposure radiation used. Or suitable for other factors such as the use of immersion liquids or the use of vacuum. Any use of the term "projection lens" herein is considered synonymous with the more general term "projection system."

As depicted herein, the device is of the transmissive type (eg, using a transmissive reticle). Alternatively, the device can be of the reflective type (eg, using a programmable mirror array of the type mentioned above, or using a reflective mask).

The lithography device can be of the type having two (dual platforms) or more than two substrate stages (and/or two or more reticle stages). In such "multi-platform" machines, additional stations may be used in parallel, or preliminary steps may be performed on one or more stations while one or more other stations are used for exposure.

The lithography apparatus can also be of the type wherein at least a portion of the substrate can be covered by a liquid (eg, water) having a relatively high refractive index to fill the space between the projection system and the substrate. The immersion liquid can also be applied to other spaces in the lithography apparatus, such as between the reticle and the projection system. Immersion techniques are well known in the art for increasing the numerical aperture of a projection system. The term "immersion" as used herein does not mean that a structure such as a substrate must be immersed in a liquid, but rather only means that the liquid is located between the projection system and the substrate during exposure.

Referring to Figure 1, illuminator IL receives a radiation beam from radiation source SO. For example, when the source of radiation is a quasi-molecular laser, the source of radiation and the lithography device can be separate entities. In such cases, the radiation source is not considered to form part of the lithography apparatus, and the radiation beam is transmitted from the radiation source SO to the illuminator IL by means of a beam delivery system BD comprising, for example, a suitable guiding mirror and/or beam amplifier. In other cases, for example, when the source of radiation is a mercury lamp, the source of radiation may be an integral part of the lithography apparatus. The radiation source SO and illuminator IL together with the beam delivery system BD (when needed) may be referred to as a radiation system.

The illuminator IL may comprise an adjustment for adjusting the angular intensity distribution of the radiation beam AD. Generally, at least the outer radial extent and/or the inner radial extent (commonly referred to as σ outer and σ inner, respectively) of the intensity distribution in the pupil plane of the illuminator can be adjusted. Further, the illuminator IL may include various other components such as the concentrator IN and the concentrator CO. The illuminator can be used to adjust the radiation beam to have a desired uniformity and intensity distribution in its cross section.

The radiation beam B is incident on a patterned device (e.g., reticle MA) that is held on a support structure (e.g., reticle stage MT) and patterned by the patterned device. After traversing the reticle MA, the radiation beam B passes through the projection system PS, and the projection system PS focuses the beam onto the target portion C of the substrate W. By means of the second positioner PW and the position sensor IF (for example an interference measuring device, a linear encoder or a capacitive sensor), the substrate table WT can be moved precisely, for example, in the path of the radiation beam B Different target parts C. Similarly, the first locator PM and another position sensor (which is not explicitly depicted in Figure 1) can be used, for example, after mechanical scooping from the reticle library or during scanning relative to the radiation beam The path of B to accurately position the mask MA. In general, the movement of the reticle stage MT can be achieved by means of a long stroke module (rough positioning) and a short stroke module (fine positioning) forming part of the first positioner PM. Similarly, the movement of the substrate table WT can be accomplished using a long stroke module and a short stroke module that form part of the second positioner PW. In the case of a stepper (as opposed to a scanner), the reticle stage MT can be connected only to a short-stroke actuator or can be fixed. The mask MA and the substrate W can be aligned using the mask alignment marks M1, M2 and the substrate alignment marks P1, P2. Although the substrate alignment marks occupy a dedicated target portion as illustrated, they may be located in the space between the target portions (this is referred to as a scribe line alignment mark). similar In the case where more than one die is provided on the reticle MA, the reticle alignment mark may be located between the dies.

The depicted device can be used in at least one of the following modes:

1. In the step mode, when the entire pattern to be applied to the radiation beam is projected onto the target portion C at a time, the mask table MT and the substrate table WT are kept substantially stationary (ie, a single static exposure). . Next, the substrate stage WT is displaced in the X and/or Y direction so that different target portions C can be exposed. In step mode, the maximum size of the exposure field limits the size of the target portion C imaged in a single static exposure.

2. In the scan mode, when the pattern to be given to the radiation beam is projected onto the target portion C, the mask table MT and the substrate table WT are scanned synchronously (i.e., single-shot dynamic exposure). The speed and direction of the substrate stage WT relative to the mask table MT can be determined by the magnification (reduction ratio) and image inversion characteristics of the projection system PS. In the scan mode, the maximum size of the exposure field limits the width of the target portion in a single dynamic exposure (in the non-scanning direction), and the length of the scanning motion determines the height of the target portion (in the scanning direction).

3. In another mode, when the pattern to be imparted to the radiation beam is projected onto the target portion C, the reticle stage MT is held substantially stationary, thereby holding the programmable patterning device and moving or scanning the substrate table WT. In this mode, a pulsed radiation source is typically used and the programmable patterning device is updated as needed between each movement of the substrate table WT or between successive pulses of radiation during the scan. This mode of operation can be readily applied to matte lithography utilizing a programmable patterning device such as a programmable mirror array of the type mentioned above.

Combinations and/or variations or completely different modes of use of the modes of use described above may also be used.

2 and 3 respectively show side and top views of a substrate support in accordance with an embodiment. The substrate support is indicated generally by reference numeral 1. The substrate support 1 comprises a support structure 2 (eg, a mirrored block, also referred to as a chuck) on which the substrate table WT is placed (and possibly clamped).

The top side of the substrate support 1 includes a vacuum clamp 4 to clamp the substrate W onto the substrate support 1. The substrate support 1 further comprises three collapsible pins 5 (commonly referred to as e-pins) which can extend between the extended position of the pin 5 extending from the substrate support 1 and the contracted position of the pin 5 in the substrate support 1 Moving relative to the substrate support 1 .

It should be understood that Figure 2 shows one possible embodiment. According to another embodiment, the e-pin 5 may not be part of the substrate support 1 but may be part of the support structure and/or the structure supporting the substrate support 1. The e-pin 5 can also, for example, be part of a second positioner PW as described with reference to FIG. The collapsible pin 5 is movable in a substantially vertical direction, that is, in a direction substantially perpendicular to the principal plane of the substrate W to be supported by the pin 5. The shrinkable pin 5 can be used to transfer the substrate W between the substrate support 1 and a robot or any other type of substrate handler. The shrinkable pin 5 is provided such that the robot can be placed under the substrate W for supporting the substrate W. When the robot is configured to hold the substrate W at the side or the top, the shrinkable pin 5 can be omitted.

The robot can place the substrate W on the pin 5 in the extended position. Next, the pin 5 can be moved to the retracted position such that the substrate W is stopped on the support surface of the substrate support 1. The substrate W supported by the substrate support 1 is exposed to After the radiation beam is patterned, it can be exchanged with another substrate. In order to exchange the substrate W, the shrinkable pin 5, which is moved from the self-retracting position to the extended position, is lifted from the substrate table WT. When the pin 5 is in the extended position, the substrate W can be taken over by a robot or any other type of substrate handler.

The vacuum clamp 4 is formed by a recessed surface 6 which is surrounded by a sealing rim 7. The air suction duct 8 is provided to form a low pressure in a vacuum space bounded by the recessed surface 6, the sealing rim 7, and the substrate W placed on or to be placed on the substrate support 1. The air suction duct 8 is connected to the air suction pump PU to draw air out of the vacuum space. The lower pressure provides a vacuum force that draws the substrate W toward the substrate support 1 above the support surface.

In the recessed surface 6, a plurality of nodules (protrusions) 9 are arranged. The top end of the knob 9 provides a support surface to the substrate W to be placed on the substrate support 1. The tips of the sealing rim 7 and the knob 9 can be disposed in substantially the same plane to provide a generally planar surface for supporting the substrate W having a relatively small contact area. The sealing rim 7 acts as a seal and does not require contact with the substrate W. A very small gap may exist between the substrate W and the rim 7 to create a controlled leak.

In an embodiment of the substrate support 1, two or more vacuum clamps may be provided as clamping means. In fact, other types of clamping devices, such as electrostatic chucks, magnetic clamps or electromagnetic clamps, may also be provided to provide the attractive force applied to the substrate W.

When the substrate W is positioned on the substrate stage WT and clamped to the substrate stage WT, the temperature of the substrate W and the temperature of the substrate stage WT may be different and generally distributed differently. Also, the temperature difference may exist in the substrate W or in the substrate stage WT. Base After the plate W is positioned on the substrate table WT, the isothermal temperature will be neutralized and the temperature balance will be stabilized. Due to such temperature changes, the substrate W and the substrate table WT are deformable and will experience thermal stress. Therefore, when the substrate W is nipped onto the substrate stage WT and its initial temperature before loading is deviated from the temperature of the substrate stage WT, or when the substrate W and/or the substrate stage WT have an internal temperature difference before loading, the substrate W Can experience thermal stress. Thermal stress can cause the substrate W to slide on the substrate stage (on the nodules 9), which causes positioning errors.

The stress in the substrate W can also be induced by positioning the substrate W on the substrate stage WT. For example, when the substrate W is placed on the retractable pin 5 in the extended position, the substrate W may first touch a pin 5 before touching the other pin 5. This can result in mechanical stress (referred to as load induced stress).

It should be understood that when the substrate W is positioned (and possibly clamped) on the substrate table WT, stress can be induced in the substrate W. Substrate loading induced stress and thermal stress are large coverage facilitators.

Since the substrate W can be held in another form different from the desired form, the coverage of the projection of the lithography apparatus may be reduced, which may have a negative impact on product quality.

A possible way to reduce thermal stress is to precisely control the temperature of the substrate W and match it to the temperature of the substrate table WT before loading the substrate W to the substrate table WT. However, this is a time consuming method that requires a device to measure and control the temperature of the substrate W (and possibly the substrate table WT). Precise control of the substrate temperature is therefore relatively complicated and expensive and results in a loss of yield.

Example

Embodiments are provided to overcome thermal stresses that may occur as described above and Load induced stress. According to an embodiment provided herein, the first object is first loaded onto the second object in the lithography apparatus, and after a predetermined settling time interval in which the temperature difference can be balanced, a slack action is performed, wherein the first object and/or the first object is allowed The second object is slack or unstressed. As described above, the first article may not be able to relax due to friction between the first article and the second article when loaded on the second article and clamped to the second article. Therefore, the slack action includes reducing the friction between the first object and the second object. The first object may be a substrate, and the second object may be a substrate table WT. According to an alternative, the first object may be the substrate table WT and the second object may be the support structure 2 supporting the substrate table WT. The support structure can also be referred to as a chuck or mirror block.

The friction can be reduced by reducing the normal force applied by the second article supporting the first article. Several embodiments for performing this operation will be described below.

A method of loading a first item onto a second item in a lithography apparatus is provided, wherein the method comprises: a) loading the first item on the second item, b) waiting for a predetermined time interval, c) performing a slack action .

Further, a lithography apparatus constructed to hold a first object on a second item is provided, wherein the lithography apparatus is configured to: a) load the first item onto the second item, b) wait for a predetermined time interval , and c) perform a slack action.

The first object may be the substrate W and the second object may be the substrate table WT. according to In one embodiment, the first object may be the substrate table WT, and the second object may be the support structure 2 for supporting the substrate table WT.

Further, a device fabrication method is provided that includes transferring a pattern from a patterned device onto a substrate W, wherein the device fabrication method includes performing one of the methods described in the embodiments.

An example of this slack action is provided in the following embodiments.

In an embodiment, the waiting time for waiting between loading the first item on the second item and performing the slack action is selected to achieve a partial temperature balance between the first item and the second item. For example, in the case where the initial temperature difference between the substrate W and the substrate table WT needs to be stabilized to a difference of about 100 mK to 150 mK, a time interval of about 3 seconds may be adapted to allow temperature difference balance. Here, 150mK can be considered as the maximum acceptable temperature difference. Of course, this time interval depends on the initial temperature difference and the thermal properties of the material. In an embodiment, the time interval for waiting is predetermined, for example, based on a model of expected temperature difference or worst case temperature difference and stability for temperature difference.

A slack action is performed to reduce stresses in the first object and the second object, including thermal stress and load induced stress.

It should be understood that action b) (i.e., waiting for a predetermined time interval) does not mean that additional or other actions may not be performed during this action. For example, while waiting for a predetermined stabilization interval, the substrate table WT loaded with the substrate W can be moved from the loading position to a measurement position where measurement (measurement shape, orientation, position, etc.) can be performed on the substrate W or To the exposure position.

Example 1

According to an embodiment, the slack action comprises temporarily reducing the clamping force applied by the gripping means.

As described above, the clamping device can be provided and can be applied when the substrate W is loaded on the substrate table WT. The clamping device clamps the substrate W to the substrate table WT by providing an attractive force applied to the substrate. The clamping device can include at least one of a vacuum clamp, an electrostatic clamp, a magnetic clamp, and an electromagnetic clamp.

According to this embodiment, the slack action includes temporarily reducing the grip force.

A method as described above is provided wherein act a) comprises using a clamping device to clamp the substrate to the substrate stage by providing an attractive force applied to the substrate. The clamping device can include at least one of a vacuum clamp, an electrostatic clamp, a magnetic clamp, and an electromagnetic clamp. Action c) of the method may include temporarily reducing the clamping force.

Further, a lithography apparatus as described above is provided, wherein the lithography apparatus further comprises a clamping device for clamping the substrate W to the substrate table WT by the attraction force applied to the substrate W, and the action a) includes using The substrate W is clamped to sandwich the substrate W to the substrate stage WT. The clamping device can include at least one of a vacuum clamp, an electrostatic clamp, a magnetic clamp, and an electromagnetic clamp. Action c), as may be performed by the lithography apparatus, may include temporarily reducing the clamping force.

This embodiment is easy to construct in that it does not require additional hardware features. Embodiments use hardware that is commonly used in lithography devices, and thus is simple and cost effective to construct. In some cases, merely loosening the substrate W may not be sufficient to relax all of the stress in the substrate W. However, embodiments provide an extremely simple way to at least relax some of the stresses present in the substrate W.

Example 2

According to an embodiment, the slack action may include lifting the substrate W from the substrate table WT. This is done after temperature averaging has occurred and is carried out to give a space for relaxation stress. After the relaxation has occurred, the substrate W is placed back on the substrate stage WT.

As described above, the substrate stage WT can include a collapsible pin 5 that can be used to perform a slack action by lifting the substrate W from the substrate table WT. Figure 4a depicts the substrate W loaded on the substrate table WT with the pin in the retracted position. Figure 4b shows the substrate W in the elevated position. After the slack operation has been performed, the substrate W is placed on the substrate stage WT again.

A method as described is provided wherein the slack action can include lifting the substrate W from the substrate table WT. This can be done by moving the pin 5, which can move in a direction substantially perpendicular to the major surface of the substrate table, the pin 5 moving from the pin to the contracted position in the substrate support 1 to the pin 5 from the substrate support The extended position of 1 extends to lift the substrate W from the substrate stage WT. The major surface is the surface that contacts the substrate during clamping of the substrate.

Further, a lithography apparatus as described above is provided, wherein the lithography apparatus includes means for temporarily lifting the substrate W from the main surface of the substrate stage, and the relaxation action c) includes lifting the substrate W from the substrate stage WT. The lithography apparatus can include a pin 5 that is movable in a direction generally perpendicular to a major surface of the substrate table WT, and the slack action includes moving the pin 5 from the pin 5 to a retracted position in the substrate table WT to the pin 5 The extended position of the substrate stage WT extends to lift the substrate from the substrate stage WT. After the substrate W has been lifted from the substrate stage WT, the substrate W is again positioned on the main surface of the substrate stage WT.

It should be understood that this embodiment can be performed in conjunction with previous embodiments in which the slack action includes reducing the clamping force applied by the gripping device. The clamping force can be lowered before the substrate W is lifted from the substrate table WT, and can be applied again after the substrate W has been positioned on the substrate stage after the relaxation operation.

This embodiment is easy to construct in that it does not require additional hardware features. Embodiments use hardware that is commonly used in lithography devices, and thus is simple and cost effective to construct.

Example 3

According to another embodiment, the slack action is performed by applying a positive pressure on the substrate W and thereby reducing the friction between the substrate W and the substrate table WT. In the case of using a clamping device, the clamping force can be reduced.

The slack action can be performed by applying a tightly controlled positive pressure in a compartment between the substrate table WT and the substrate W for a predetermined (short) period of time. By performing this process, it is possible to reduce the friction between the substrate W and the substrate stage WT, and even lift the substrate from the substrate stage WT and thus enable the substrate W to reduce internal stress. The process can be repeated when a single pulse is not sufficient to remove all stresses. By using a number of relatively small pulses instead of one long pulse, floating (i.e., moving) of the substrate can be avoided, which can result in potential substrate loss. Air pulses may be generated by pressurizing the small container with air and then using a simple two-way valve to release air through the holes in the substrate table WT.

5 and 6 schematically depict a substrate holder 1 according to this embodiment. As shown in Figure 5, a plurality of nozzles 10 are provided. As shown in FIGS. 5 and 6, the nozzle 10 is provided between the tumors 9. However, it should be understood that the nozzles may also be provided in a plurality of nodules 9. In the embodiment shown in Figures 5 and 6, the nozzle 10 is uniform The ground is distributed over the surface area bounded by the sealing rim 7. The nozzle 10 is coupled to the gas supply unit via a gas supply conduit 11 and is configured to provide an injection or gas pulse in a direction generally perpendicular to the recessed surface, that is, substantially perpendicular to the substrate table WT to be disposed The main plane of the substrate W. In order to actually provide an injection or gas pulse, the gas supply unit may be a pump (not shown), or another source of pressurized gas connected to the supply conduit 11. As shown in FIG. 5, a vessel CO is provided which contains a gas having a pressure high relative to the pressure in the vicinity of the substrate table WT. In the supply pipe 11, a valve VA is provided which can be controlled to open and close the supply pipe 11. It is noted that any type of suitable gas, such as air, may be used for the provision of the jet.

A method as described above is provided wherein the relaxation action comprises supplying a gas between the substrate W and the substrate table WT. The gas can be supplied by a sequence of at least one gas pulse.

Furthermore, a lithography apparatus as described above is provided, wherein the substrate stage WT comprises at least one nozzle 10 connected or connectable to a gas supply unit and configured to supply gas between the substrate W and the substrate table WT, And the relaxation action can include supplying a gas between the substrate and the substrate stage. The lithography apparatus can be configured to supply gas in a sequence of at least one gas pulse.

It should be understood that this embodiment can be performed in conjunction with previous embodiments in which the slack action includes reducing the clamping force applied by the gripping device. The clamping force can be reduced before the supply gas can be applied again after the relaxation action.

Example 4

According to another embodiment, the slack action comprises vibrating the substrate table WT. By When appropriate vibration is applied, the friction between the substrate W and the substrate stage WT is lowered, thereby allowing the substrate to be slack. The vibration can be performed at any suitable frequency and by any suitable amplitude (e.g., at an amplitude of about 1 [mu]m and a frequency of > 500 Hz or more).

Fig. 7 schematically shows a substrate holder 1 comprising a substrate table WT on which a substrate W is loaded. Figure 7 further shows a vibrating device formed by two actuators AC that can be used to actuate the substrate holder 1 and thus vibrate the substrate table WT.

The vibrating device can be formed by the second locator PW which has been described above with reference to FIG. However, special special actuators can also be provided to perform the vibration.

Actuators may be provided in particular, but it is also possible to use an actuator that is already present, such as a short stroke motor that drives the support structure. The actuator can be a Lorentz type actuator with nm accuracy with a high frequency wide servo loop. These motors are used to position the support structure and substrate W during exposure and measurement. By merely adding a dither signal to the normal set point, the support structure can be commanded to move in the target direction while providing vibrational movement.

Vibration is applied for a time interval after the substrate W is loaded on the substrate table WT to allow the substrate W and the substrate table WT to at least partially stabilize each of the substrate W and the substrate table WT or the substrate W and the substrate table WT. The temperature difference between. The time interval is selected such that the expected difference is below the maximum acceptable temperature difference. The clamping force that may be applied can be reduced, and the substrate table WT can be vibrated at a high frequency. The vibration can have a small position amplitude and a large acceleration. This mechanical "jitter" motion can be used to overcome the friction between the substrate W and the substrate table WT. The substrate W will then reduce its internal stress.

The vibration may be applied in a direction substantially perpendicular to the surface of the substrate stage WT, that is, substantially perpendicular to the principal plane of the substrate W to be disposed on the substrate stage WT. During the downward movement, the normal force applied to the substrate W by the substrate stage WT (and thus the frictional force is temporarily lowered) is temporarily lowered, and the substrate W can be relaxed.

According to a variant, the vibration is applied in a direction substantially parallel to the surface of the substrate table WT, i.e. substantially parallel to the main plane of the substrate W to be placed on the substrate table WT. Due to this movement, the substrate W and the substrate stage WT can be relatively moved with respect to each other, thereby reducing the frictional force and allowing the substrate W to be relaxed (note that the static friction coefficient is higher than the dynamic friction coefficient).

In an alternate embodiment, vibration is applied in a direction different from the two directions described herein (e.g., in the diagonal direction) having a component that is parallel and perpendicular to the surface of the substrate table WT.

In another embodiment, the vibration is applied directly to the substrate. The vibrating action can be applied by using a vibrating tool such as a spring or a flexible element. The vibration tool can be actuated. A suitable actuator can be used. In an embodiment, a vibratory action is applied to the substrate that begins in a central portion of the substrate. The vibration action can be applied to the substrate/object by the center gripper. In another step, a subsequent vibratory action can be applied to more of the externally positioned portion of the object. In this way, the stress in the article is preferably "moved" (preferably "released") to the outer portion of the article. In an embodiment, the E pin is used as a vibrating device to vibrate the object.

The vibration action can be a very short action, for example, only one or even a half cycle. The vibration action is characterized by at least one action, preferably relative to the balance The movement of the location. It can be shifted for offset. It is believed that this vibrational action will have a stress reduction effect in the object, as the vibrating action can cause movement through the wave stress relief projections such as the material of the article. It is believed that this type of wave motion is more effective in reducing the regional stress area in the object.

In another embodiment, a striking device can be used to apply vibration to the object. By striking the object, a one-time interference, in this case excessive interference, is transferred to the object, which can be used to dissipate or release other internal stresses on the object. The striking device can also initiate wave motions such as in objects.

In one embodiment, the vibrations are applied to the substrate and substrate stage, either partially or one by one.

A method and lithography apparatus are provided in which a substrate stage and/or a substrate are vibrated at high frequencies and small amplitudes. Further, a lithography apparatus as described is provided wherein the substrate stage includes a vibrating device and the slack action comprises vibrating the substrate stage.

It should be understood that this embodiment can be performed in conjunction with previous embodiments in which the slack action includes reducing the clamping force applied by the gripping device. The clamping force can be reduced before the supply gas can be applied again after the relaxation action.

Example 5

The embodiments described above describe how to mount the substrate W on the substrate stage WT. However, the substrate table WT itself may be a separate portion that is positioned on the support structure 2. The substrate table WT can be clamped to the support structure 2 using a clamping device comprising at least one of a vacuum clamp, an electrostatic clamp, a magnetic clamp, and an electromagnetic clamp.

When stress occurs in the substrate stage, it can be compared with the procedure described above. The same relaxation procedure is applied to the substrate stage, which ultimately results in slippage between the substrate table WT and the support structure 2.

It should be understood that loading the substrate stage WT on the support structure 2 may involve the same problem as the problem of loading the substrate W on the substrate stage WT, that is, thermal stress and mechanical stress may be induced in the substrate stage WT.

Therefore, the above-mentioned embodiments can also be used to load the substrate table WT onto the support structure 2.

Accordingly, a method of loading a substrate stage onto a support structure can be provided, wherein the method includes: a) loading the substrate stage onto the support structure, b) waiting for a predetermined time interval, and c) performing a slack action.

Action a) may include using a clamping device to clamp the substrate table to the support structure by providing an attractive force applied to the substrate table. The clamping device can include at least one of a vacuum clamp, an electrostatic clamp, a magnetic clamp, and an electromagnetic clamp.

Act c) may include temporarily reducing the clamping force and/or may include supplying a gas between the substrate table and the support structure. The gas can be supplied by a sequence of at least one gas pulse.

Action c) may further comprise a vibrating support structure. The support structure can be vibrated at high frequencies and small amplitudes.

Vibration is applied at a short time interval after the substrate stage is loaded on the support structure. In an embodiment, the clamping force is reduced. Alternatively or additionally, the support structure is vibrated at high frequencies. The vibration has a small position amplitude and a large acceleration. This mechanical "jitter" motion is used to overcome the friction between the substrate table WT and the support structure force. The substrate table WT will then reduce its internal stress.

Act c) may further comprise, for example, lifting the substrate table WT from the support structure 2 by moving the pin, the pin being movable in a direction substantially perpendicular to the major surface of the support structure, the pin shrinking from the pin in the support structure The position is moved to an extended position where the pin extends from the support structure to lift the substrate table from the main surface of the self-supporting structure.

The waiting time interval may be selected to allow the substrate W and the substrate table WT to at least partially stabilize the temperature difference within each of the substrate W and the substrate table WT or between the substrate W and the substrate table WT.

Act c) can be performed to reduce the stress in the substrate table WT.

Furthermore, a lithographic apparatus comprising a support structure 2 constructed to hold a substrate table WT can be provided, wherein the lithography apparatus is configured to: a) load the substrate table WT onto the support structure 2, b) wait for a predetermined settling time interval , and c) perform a slack action.

computer

All of the embodiments described above can be put into practice using, for example, the computer CO shown in FIG. The computer CO can include a processor PR configured to communicate with the input and output device I/O and the memory ME.

The computer CO can be a personal computer, a server, or a laptop. All of these devices are different types of computers. The memory ME can include instructions that can be read and executed by the processor PR to cause the computer CO to perform the described embodiments. The computer CO can be configured to interact with other portions of the lithography apparatus via input and output device I/O to perform the described embodiments.

8 shows a schematic block diagram of an embodiment of a computer CO that includes a processor PR for performing arithmetic operations. The processor PR is connected to a memory ME that can store instructions and data, such as a tape unit, a hard disk, a read only memory (ROM), an electronic erasable programmable read only memory (EEPROM), and a random access memory. Body (RAM).

The input output device I/O is configured to communicate with other computer systems or devices included by the lithography apparatus 1 (not shown) via a communication link.

However, it should be understood that more and/or other memory MEs and processors PR may be provided. Further, one or more of them may be physically located at a remote location. The processor PR is shown as a box, however, as is known to those skilled in the art, it can include a number of processors PR that function in parallel or are controlled by a host processor that can be located away from each other.

It has been observed that although all connections are shown as physical connections, one or more of these connections can be made wireless. It is only intended to show that "connected" units are configured to communicate with one another in some manner.

A computer program is provided that is configured to perform any of the provided methods when loaded on a computer configuration. Also, a data carrier is provided that includes the computer program. The data carrier can be any type of computer readable medium.

Also pay attention

The embodiments described above refer to the choice of reducing the clamping force. It should be understood that this can be done in conjunction with all other embodiments. Again, reducing the clamping force involves reducing the clamping force to substantially zero, i.e., no clamping force is applied at all.

Gas supply and application can be applied with relatively small yield loss An example of adding vibration. Again, there is no limit to the position at which the slack motion can be performed as the substrate stage in which the existing metrology sequence is located.

This may have a negative impact on the accuracy of the pre-alignment when the substrate W (Example 2) is lifted from the substrate table WT. Further, for machine/substrate safety reasons, the lifting of the substrate (Embodiment 2) can be performed only at a very specific position where the non-productivity of the substrate table WT is optimal.

Based on the above description, it should be understood that the relaxation action is performed to temporarily reduce the friction between the substrate W and the substrate stage WT, thereby allowing the substrate W to relax and allow stress relief. A number of ways are provided to perform the slack action, such as reducing the clamping force, lifting the substrate W, providing gas between the substrate W and the substrate table WT, and vibrating the substrate table WT.

It should be understood that the slack action will be performed in such a manner as to accurately position the substrate W relative to the substrate stage WT after the relaxation operation to enable accurate processing of the substrate W. In fact, the substrate W should be within the capture range of the sensor for measuring the position and orientation of the substrate W, such as an alignment sensor for measuring the horizontal orientation of the substrate and for measuring the surface of the substrate. Profile sensor for the profile. The capture range is approximately tens of microns.

After the relaxation action, another measurement action can be performed to measure the position and orientation of the substrate W.

Also, it should be understood that all embodiments may be utilized in connection with one or more other embodiments. For example, vibration can be performed in conjunction with supplying gas and/or reducing clamping force.

Embodiments may be performed to temporarily overcome the friction between the first item and the second item to allow the first item to settle.

Although reference may be made herein specifically to the use of lithographic apparatus in IC fabrication, it should be understood that the lithographic apparatus described herein may have other applications, such as fabrication of integrated optical systems, for magnetic domain memory. Guide and detection patterns, flat panel displays, liquid crystal displays (LCDs), thin film heads, and more. Those skilled in the art will appreciate that any use of the terms "wafer" or "grain" herein is considered synonymous with the more general term "substrate" or "target portion", respectively, in the context of such alternative applications. The substrates referred to 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 a test tool. Where applicable, the disclosure herein can be applied to such and other substrate processing tools. Additionally, the substrate can be processed more than once, for example, to form a multi-layer IC, such that the term substrate as used herein may also refer to a substrate that already contains multiple processed layers.

Although the above may be specifically referenced to the use of embodiments of the invention in the context of optical lithography, it will be appreciated that the invention may be used in other applications (eg, embossing lithography) and is not limited where context permits Optical lithography. In imprint lithography, the configuration in the patterned device defines a pattern formed on the substrate. The patterning device can be configured to be pressed into a resist layer that is supplied to the substrate where the resist is cured by application of electromagnetic radiation, heat, pressure, or a combination thereof. After the resist is cured, the patterned device is removed from the resist to leave a pattern therein.

The terms "radiation" and "beam" as used herein encompass all types of electromagnetic radiation, including ultraviolet (UV) radiation (eg, having or being about 365 nm, 355 nm, 248 nm, 193 nm, 157 nm, or 126 nm). Wavelength) And far ultraviolet (EUV) radiation (eg, having a wavelength in the range of 5 nm to 20 nm); and a particle beam (such as an ion beam or an electron beam).

The term "lens", when the context permits, may refer to any or a combination of various types of optical components, including refractive, reflective, magnetic, electromagnetic, and electrostatic optical components.

Although the specific embodiments of the invention have been described hereinabove, it is understood that the invention may be practiced otherwise than as described. For example, the invention can take the form of a computer program containing one or more sequences of machine readable instructions for describing a method as disclosed above; or a data storage medium (eg, a semiconductor memory, disk or optical disk) ), which has the computer program stored therein.

The above description is intended to be illustrative, and not restrictive. It will be apparent to those skilled in the art that the present invention may be modified as described without departing from the scope of the appended claims.

1‧‧‧Substrate support

2‧‧‧Support structure

4‧‧‧vacuum fixture

5‧‧‧Compensable pin

6‧‧‧ recessed surface

7‧‧‧ Sealing rim

8‧‧‧Air suction pipe

9‧‧‧noma

10‧‧‧ nozzle

11‧‧‧ gas supply pipeline

AC‧‧‧ actuator

AD‧‧‧ adjuster

B‧‧‧radiation beam

BD‧‧‧beam transmission system

C‧‧‧Target section

CO‧‧‧Container/Computer/Condenser

I/O‧‧‧Input and output devices

IF‧‧‧ position sensor

IL‧‧‧Lighting System

IN‧‧‧ concentrator

M1‧‧‧mask alignment mark

M2‧‧‧Photomask alignment mark

MA‧‧‧patterned device

ME‧‧‧ memory

MT‧‧‧Support structure

P1‧‧‧ substrate alignment mark

P2‧‧‧ substrate alignment mark

PM‧‧‧First Positioner

PR‧‧‧ processor

PS‧‧‧Projection System

PU‧‧‧Air suction pump

PW‧‧‧Second positioner

SO‧‧‧radiation source

VA‧‧‧ valve

W‧‧‧Substrate

WT‧‧‧ substrate table

X‧‧‧ direction

Y‧‧‧ direction

1 schematically depicts a lithography apparatus in accordance with an embodiment of the present invention; FIG. 2 schematically depicts a cross-sectional view of a substrate support in accordance with an embodiment; FIG. 3 schematically depicts a substrate support in accordance with an embodiment. FIG. 4a and FIG. 4b schematically show cross-sectional views of a substrate stage according to an embodiment; FIG. 5 schematically depicts a cross-sectional view of a substrate support according to an embodiment; Figure 6 schematically depicts a top view of a substrate support in accordance with an embodiment; Figure 7 schematically depicts a substrate support in accordance with an embodiment; and Figure 8 schematically depicts a computer in accordance with an embodiment.

1‧‧‧Substrate support

2‧‧‧Support structure

5‧‧‧Compensable pin

6‧‧‧ recessed surface

7‧‧‧ Sealing rim

9‧‧‧noma

10‧‧‧ nozzle

11‧‧‧ gas supply pipeline

CO‧‧‧Container/Computer/Condenser

VA‧‧‧ valve

WT‧‧‧ substrate table

Claims (26)

A method of loading a first object onto a second object in a lithography apparatus, wherein the method comprises: loading the first object onto the second object; waiting for a predetermined time interval; and waiting for the After a predetermined time interval, wherein the predetermined time interval is selected to achieve a temperature balance between the first object and the second object, and performing a relaxation action to reduce friction between the first object and the second object , wherein the relaxing action comprises vibrating the second object. The method of claim 1, wherein the first object is a substrate and the second object is a substrate stage. The method of claim 1, wherein the first object comprises a substrate stage, and the second object comprises a support structure for supporting the substrate stage. The method of claim 1, wherein the loading comprises using a clamping device to clamp the first article to the second article by providing an attractive force applied to the first article. The method of claim 4, wherein the clamping device comprises at least one of a vacuum clamp, an electrostatic clamp, a magnetic clamp, and an electromagnetic clamp. The method of claim 4, wherein the relaxing action comprises temporarily reducing the clamping force. The method of claim 1, wherein the second object is vibrated at a high frequency and a small amplitude. The method of claim 1, wherein the slack action comprises moving the pins, the pins being in a direction substantially perpendicular to a major plane of the second object Moving, the pins are moved from a retracted position of the pins to the one of the second members to a position in which the pins extend from the second member to temporarily lift the first member from the second member. The method of claim 1, wherein the relaxing action is performed to reduce stress in the first object. The method of claim 1, wherein reducing the friction between the first object and the second object comprises adding a jitter signal to the actuator to vibrate the second object. The method of claim 1, wherein the relaxing action comprises temporarily lifting the first item from the second item. The method of claim 1, wherein the relaxing action comprises supplying a gas between the first object and the second object. The method of claim 1, wherein the gas system is supplied through a sequence of at least one gas pulse. A lithography system comprising: a lithography apparatus configured to hold a first object on a second object, wherein the lithography apparatus is configured to: load the first object on the second Waiting for a predetermined time interval; and waiting for the predetermined time interval, wherein the predetermined time interval is selected to achieve a temperature balance between the first object and the second object, by performing a slack action to reduce the a frictional force between the first object and the second object, wherein the relaxing action comprises vibrating the second object. The system of claim 14, wherein the first object is a substrate and the second The object is a substrate table. The system of claim 14, wherein the first object is a substrate table, and the second object is a support structure for supporting the substrate table. The system of claim 14, wherein the lithography apparatus further comprises a clamping device configured to clamp the first object to the second by providing an attractive force applied to the first object An article, and the loading includes clamping the first article to the second article using the clamping device. The system of claim 17, wherein the clamping device comprises at least one of a vacuum clamp, an electrostatic clamp, a magnetic clamp, and an electromagnetic clamp. The system of claim 17, wherein the relaxing action comprises temporarily reducing the clamping force. The system of claim 14, wherein the lithography apparatus is configured to vibrate at a high frequency and a small amplitude. The system of claim 14, wherein: the lithography apparatus includes a lifting device configured to temporarily lift the first object from the second object; and the relaxing action includes temporarily lifting the first object from the second object . The system of claim 21, wherein: the lithography apparatus comprises a pin, the pins being movable in a direction substantially perpendicular to a major surface of the second object; and the relaxing action comprises loading the pin The pin is contracted to a retracted position in the second article to move to an extended position of the pin from the second article to temporarily lift the first article from the second article. The system of claim 14, wherein the slack action is performed to reduce the number The stress in an object. The system of claim 16, further comprising commanding the support structure to move in a target direction while providing the vibrational movement. The system of claim 14, wherein the second object has at least one nozzle configured to be coupled to a gas supply unit and to supply a gas between the first object and the second object, and wherein the relaxing action The gas is supplied between the first object and the second object. The system of claim 25, wherein the system is configured to supply the gas in a sequence of at least one gas pulse.