JP2015503222A - Lithographic apparatus and device manufacturing method - Google Patents

Abstract

For example, an apparatus is provided in which one or more measures are taken to reduce the likelihood of contaminant particles falling onto the upper surface of a substrate, for example through a gap between a projection system module and a gas shower module. An exposure apparatus includes a projection system module (310) configured to project a radiation beam onto a substrate (W), and a gas flow on an upper surface of the substrate when not covered in a plan view by the projection system module ( 322) and a seal gas outlet providing a seal gas flow (3255) directed in a direction from the projection system module toward the gas shower module or vice versa. (325). [Selection] Figure 9

Description

This application claims the benefit of US Provisional Application No. 61 / 562,835, filed Nov. 22, 2011, which is hereby incorporated by reference in its entirety.

  The present invention relates to an exposure apparatus, a lithographic apparatus, and a method for manufacturing a device.

  A lithographic apparatus is a machine that applies a desired pattern onto a substrate or part of a substrate. Lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs), flat panel displays, and other devices or structures having fine geometries. In conventional lithographic apparatus, patterning devices, also referred to as masks or reticles, may be used to generate circuit patterns that correspond to the individual layers of the IC, flat panel display, or other device. This pattern is transferred onto (parts of) the substrate, for example by imaging onto a radiation sensitive material (resist) layer provided on the substrate (such as a silicon wafer or glass plate). Similarly, an exposure apparatus is a machine that uses a radiation beam in forming a desired pattern on or in a substrate (or portion thereof).

  In some cases, the patterning device is used to generate other patterns, such as a color filter pattern or a matrix of dots, instead of a circuit pattern. Instead of a conventional mask, the patterning device may comprise a patterning array comprising an array of individually controllable elements that produce a circuit pattern or other applicable pattern. Such a “maskless” method has an advantage that a pattern can be prepared or changed quickly and at a lower cost than a conventional method using a mask.

  Thus, maskless systems include programmable patterning devices (eg, spatial light modulators, contrast devices, etc.). The programmable patterning device is programmed (eg, electronically or optically) to form a beam with a desired pattern using an array of individually controllable elements. Types of programmable patterning devices include micromirror arrays, liquid crystal display (LCD) arrays, grating light valve arrays, and self-emitting contrast devices. Programmable patterning devices can also be formed from electro-optic polarizers, for example to move the spot of radiation projected onto the substrate, or intermittently, for example, to absorb the radiation beam from the substrate. Configured to direct to the body. In such a configuration, the radiation beam can be continuous.

  In a lithography or exposure process, multiple radiation beams can be generated, patterned, and projected onto a substrate. In one example, one or more arrays of self-radiating contrast devices may be used as described above to generate the radiation beams.

  In general, the size of the substrate is larger than the size of the projection system module used to project a plurality of radiation beams onto the substrate in plan view. This can be undesirable in that the contaminant particles, such as dust particles, can reach the top surface of the substrate when the substrate is not below the projection system module. This can lead to patterning errors (eg imaging errors), which are clearly undesirable.

  To mitigate the risk of contaminant particles reaching the (part of) the substrate not under the projection system module, one or more gas shower modules filter the portion of the substrate not under the projection system module It may be positioned adjacent to the projection system module to provide a processed gas flow.

  In some embodiments, the projection system module is mechanically isolated from the gas shower module. Thus, there is no direct connection between the projection system module and the gas shower module (eg, the two modules may be separately connected to a solid foundation, or the two modules may be dampers or other May be connected via an insulating structure). A gap may exist between the two modules. Contaminant particles can fall into the gap between the projection system module and the gas shower module and / or be attracted by the gas flow to reach the substrate. This is undesirable.

  Therefore, what is desired is an apparatus in which one or more measures have been taken, for example, to reduce the likelihood of contaminant particles falling onto the top surface of the substrate, eg, through a gap between the projection system module and the gas shower module. Is to provide.

  According to an embodiment of the present invention, a projection system module configured to project a radiation beam onto a substrate and to provide a gas flow on the top surface of the substrate when not covered in plan view by the projection system module An exposure apparatus is provided comprising: a configured gas shower module; and a seal gas outlet that provides a seal gas flow directed in a direction from the projection system module toward the gas shower module or vice versa. .

  According to an embodiment of the present invention, a gas shower for using a projection system module for projecting a radiation beam onto a substrate and providing a gas flow on the upper surface of the substrate when not covered in plan view by the projection system module There is provided a device manufacturing method comprising using a module and providing a seal gas flow directed in a direction from the projection system module toward the gas shower module or vice versa.

  Several embodiments of the present invention are described below with reference to the accompanying schematic drawings, which are exemplary only. Corresponding reference characters indicate corresponding parts in the various drawings.

1 shows a portion of a lithographic apparatus or exposure apparatus according to an embodiment of the invention.

FIG. 2 shows a top view of a portion of the lithographic apparatus or exposure apparatus of FIG. 1 according to an embodiment of the invention.

1 shows a highly schematic perspective view of a portion of a lithographic apparatus or exposure apparatus according to an embodiment of the invention.

FIG. 4 shows a schematic top view of projection onto a substrate by the lithographic apparatus or exposure apparatus according to FIG. 3 according to an embodiment of the present invention.

The cross section of the part which concerns on one embodiment of this invention is shown.

1 shows a cross section of a portion of a lithographic apparatus or exposure apparatus.

1 shows a plan view of a portion of a lithographic apparatus or exposure apparatus.

FIG. 5 shows a detailed cross section of the gap between a projection system module and a gas shower module that illustrates a problem addressed by an embodiment of the present invention.

1 shows a detailed cross section of a lithographic apparatus or exposure apparatus according to an embodiment of the invention.

1 shows a detailed cross section of a lithographic apparatus or exposure apparatus according to an embodiment of the invention.

1 shows a detailed cross section of a lithographic apparatus or exposure apparatus according to an embodiment of the invention.

1 shows a detailed cross section of a lithographic apparatus or exposure apparatus according to an embodiment of the invention.

  Certain embodiments of the present invention relate to an apparatus that may include a programmable patterning device, which may comprise, for example, one or more arrays of self-radiating contrast devices. Further information regarding such devices can be found in WO 2010/032224, US Patent Application Publication No. 2011/0188016, US Patent Application No. 61/473636, and US Patent Application No. 61/524190. The entirety is hereby incorporated by reference. However, certain embodiments of the present invention may use any form of programmable patterning device, such as those already described.

  FIG. 1 is a schematic cross-sectional side view of a portion of a lithographic apparatus or exposure apparatus. In this embodiment, the device has (but need not) individually controllable elements that are substantially stationary in the XY plane, as will be described below. The apparatus 1 includes a substrate table 2 that holds a substrate, and a positioning device 3 that moves the substrate table 2 with a maximum of 6 degrees of freedom. The substrate may be a substrate coated with a resist. In some embodiments, the substrate is a wafer. In some embodiments, the substrate is a polygonal (eg, rectangular) substrate. In some embodiments, the substrate is a glass plate. In some embodiments, the substrate is a plastic substrate. In some embodiments, the substrate is a foil. In certain embodiments, the apparatus is suitable for roll-to-roll manufacturing.

The apparatus 1 comprises a plurality of individually controllable self-radiating contrast devices 4 configured to emit a plurality of beams. In some embodiments, the self-radiating contrast device 4 is a radiant light emitting diode (eg, a light emitting diode (LED), an organic LED (OLED), a polymer LED (PLED)), or a laser diode (eg, a solid state laser diode). ). In one embodiment, each individually controllable element 4 is a blue-violet laser diode (eg, Sanyo model number DL-3146-151). Such diodes are supplied by companies such as Sanyo, Nichia, OSRAM, and Nitride. In certain embodiments, the diode emits UV radiation having a wavelength of, for example, about 365 nm or about 405 nm or about 436 nm. In some embodiments, the diode can provide an output power selected from the range of 0.5 mW to 200 mW. In one embodiment, the size of the laser diode (bare die) is selected from the range of 100 μm to 800 μm. In some embodiments, the laser diode has a light emitting region selected from the range of 0.5 μm ² to 5 μm ² . In some embodiments, the laser diode has a divergence angle selected from the range of 5 degrees to 44 degrees. In some embodiments, the diodes are configured to provide a total brightness of about 6.4 × 10 ⁸ W / (m ² · sr) or greater (eg, light emitting area, divergence angle, output power, etc.). ).

  The self-radiating contrast device 4 is disposed on the frame 5 and may extend along the Y direction and / or along the X direction. Although one frame 5 is shown in FIG. 1, the present apparatus may have a plurality of frames 5. The frame 5 is further provided with a plurality of lenses 12. The frame 5, and thus the self-radiating contrast device 4 and the lens 12 are substantially stationary in the XY plane. The frame 5, the self-radiating contrast device 4 and the lens 12 may be moved in the Z direction by the actuator 7. Alternatively or in conjunction therewith, the lens 12 may be moved in the Z direction by an actuator associated with this particular lens. Optionally, each lens 12 may be provided with an actuator.

  The self-radiating contrast device 4 may be configured to emit a beam, and the projection systems 12, 14, 18 may be configured to project the beam onto a target portion of the substrate. The self-radiating contrast device 4 and the projection system form an optical column. The apparatus 1 may include an actuator (for example, a motor 11) for moving the optical column or a part thereof with respect to the substrate. A field lens 14 and an imaging lens 18 are disposed on the frame 8, and the frame 8 may be rotatable using its actuator. The combination of the field lens 14 and the imaging lens 18 forms the movable optical system 9. In use, the frame 8 rotates about its own axis 10, for example, in the direction indicated by the arrow in FIG. The frame 8 is rotated around the axis 10 using an actuator (for example, a motor) 11. Further, the frame 8 may be moved in the Z direction by the motor 7, whereby the movable optical system 9 may be displaced with respect to the substrate table 2.

  An aperture structure 13 having an aperture on the inside may be disposed above the lens 12 and between the lens 12 and the self-radiating contrast device 4. The aperture structure 13 can limit the diffractive effects of the lens 12, the associated self-radiating contrast device 4, and / or the adjacent lens 12 / self-radiating contrast device 4.

  The illustrated apparatus may be used by rotating the frame 8 and simultaneously moving the substrate on the substrate table 2 below the optical column. The self-radiating contrast device 4 can emit a beam through the lenses 12, 14, 18 when they are substantially aligned with each other. By moving the lenses 14, 18, the image of the beam on the substrate scans a portion of the substrate. At the same time, by moving the substrate on the substrate table 2 below the optical column, the portion of the substrate exposed to the image of the self-radiating contrast device 4 is also moved. Control that switches the “on” and “off” of the self-radiating contrast device 4 at high speed by a controller that controls the rotation of the optical column or a part thereof, controls the intensity of the self-radiating contrast device 4, and controls the substrate speed. (Eg, having no output when it is “off” or having an output that is below the threshold and having an output that is above the threshold when “on”), the desired pattern on the substrate An image can be formed on the resist layer.

  FIG. 2 is a schematic top view of the apparatus of FIG. 1 having a self-radiating contrast device 4. Similar to the apparatus 1 shown in FIG. 1, the apparatus 1 shown in FIG. 2 includes a substrate table 2 that holds a substrate 17, a positioning device 3 that moves the substrate table 2 with a maximum of 6 degrees of freedom, and a self-radiating contrast device 4. And an alignment / level sensor 19 for determining whether the substrate 17 is horizontal with respect to the projection of the self-radiating contrast device 4. As shown, the substrate 17 has a rectangular shape, but circular substrates may additionally or alternatively be processed.

  The self-radiating contrast device 4 is arranged on the frame 15. The self-radiating contrast device 4 may be a radiant light emitting diode, for example a laser diode, for example a violet laser diode. As shown in FIG. 2, the self-radiating contrast devices 4 may be arranged in an array 21 extending in the XY plane.

  The array 21 may be an elongated line. In some embodiments, the array 21 may be a one-dimensional array of self-radiating contrast devices 4. In some embodiments, the array 21 may be a two-dimensional array of self-radiating contrast devices 4.

  A rotating frame 8 may be provided, which may rotate in the direction illustrated by the arrows. The rotating frame may be provided with lenses 14 and 18 (see FIG. 1) for providing an image of each self-radiating contrast device 4. This apparatus may be provided with an actuator for rotating an optical column including the frame 8 and the lenses 14 and 18 with respect to the substrate.

  FIG. 3 is a perspective view schematically showing the rotating frame 8 provided with lenses 14 and 18 in the peripheral portion. A plurality of beams, 10 beams in this embodiment, enter one of the lenses and are projected onto a target portion of the substrate 17 held by the substrate table 2. In one embodiment, the plurality of beams are arranged in a straight line. The rotatable frame can be rotated around the axis 10 by an actuator (not shown). As a result of the rotation of the rotatable frame 8, the beam set is incident on a series of lenses 14, 18 (field lens 14 and imaging lens 18). Upon entering each of the series of lenses, the beam is deflected so that the beam moves along a portion of the surface of the substrate 17. Details will be described later with reference to FIG. In one embodiment, each beam is generated by a corresponding source, ie by a self-radiating contrast device, such as a laser diode (not shown in FIG. 3). In the configuration shown in FIG. 3, both beams are deflected and carried by a segment mirror 30 to reduce the distance between the beams. Thereby, as will be described later, a larger number of beams can be projected through the same lens to achieve the required resolution.

  When the rotatable frame rotates, the beam set enters a plurality of continuous lenses. At this time, each time a lens is irradiated with the beam, the place where the beam is incident on the lens surface moves. Depending on where the beam is incident on the lens, the beam is projected onto the substrate differently (eg, with different deflections), so that the beam (which reaches the substrate) will scan and move each time the lens passes. This principle will be further described with reference to FIG. FIG. 4 is a top view schematically showing a part of the rotatable frame 8 in a highly schematic manner. The first beam set is denoted as B1, the second beam set is denoted as B2, and the third beam set is denoted as B3. Each of the beam sets is projected through a corresponding lens set 14, 18 of the rotatable frame 8. When the rotatable frame 8 rotates, a plurality of beams B1 are projected onto the substrate 17, and the region A14 is scanned by scanning movement. Similarly, the plurality of beams B2 scans the region A24, and the plurality of beams B3 scans the region A34. Simultaneously with the rotation of the rotatable frame 8, the substrate 17 and the substrate table are moved in the direction D (which may be along the X axis shown in FIG. 2) by the corresponding actuators, so that the regions A 14, A 24, A 34. Is moved substantially perpendicular to the beam scanning direction. As a result of the movement by the second actuator in direction D (eg movement of the substrate table by the corresponding substrate table motor), successive multiple beam scans are substantially relative to each other as projected by the series of lenses of the rotatable frame 8. And substantially adjacent regions A11, A12, A13, A14 occur each time the beam B1 is scanned (as shown in FIG. 4, the regions A11, A12, A13 were previously scanned, Region A14 is scanned this time), and for beam B2, regions A21, A22, A23, A24 occur (as shown in FIG. 4, regions A21, A22, A23 have been scanned previously, and region A24 has been scanned this time). In the beam B3, regions A31, A32, A33, and A34 occur (as shown in FIG. 4, the regions A31, A32, 33 is scanned earlier, area A34 is scanned time). In this way, the areas A1, A2, A3 on the substrate surface may be covered by moving the substrate in direction D while rotating the rotatable frame 8. By projecting multiple beams through the same lens, the entire substrate can be processed in less time (assuming the rotatable frame 8 is at the same rotational speed). This is because a plurality of beams scan the substrate with each lens every time the lens passes, so that the amount of displacement in the direction D can be increased during a plurality of successive scans. In other words, when a large number of beams are projected onto the substrate through the same lens, the rotational speed of the rotatable frame at a given processing time may be reduced. In this way, the influence of high rotational speed such as deformation, wear, vibration, turbulence, etc. of the rotatable frame may be reduced. In one embodiment, as shown in FIG. 4, the plurality of beams are arranged at an angle with respect to the tangent of rotation of the lenses 14, 18. In some embodiments, the plurality of beams are arranged such that each beam overlaps or each beam is adjacent to the scanning path of adjacent beams.

  A further effect of the aspect of projecting multiple beams at once with the same lens can be seen in tolerance reduction. Due to lens tolerances (positioning, optical projection, etc.), the position of successive areas A11, A12, A13, A14 (and / or areas A21, A22, A23, A24 and / or A31, A32, A33, A34) Some inaccuracy may appear in the positioning of each other. Therefore, some overlap may be required between successive regions A11, A12, A13, A14. If, for example, 10% of one beam is overlapped, if there is one beam at a time on the same lens, the processing speed will be similarly reduced by a factor of 10%. On the other hand, in a situation where 5 or more beams are projected at the same time through the same lens, the same 10% overlap (for one beam as above) is every 5 or more projection lines. If so, the total overlap would be reduced to 2% (or less), which is roughly one fifth (or more). This has the effect of significantly reducing the overall processing speed. Similarly, by projecting at least 10 beams, the total overlap can be reduced to approximately one tenth. Therefore, the influence of tolerance generated in the processing time of the substrate can be reduced by the feature that a plurality of beams are simultaneously projected by the same lens. In addition or alternatively, a larger overlap (and thus a larger tolerance width) may be allowed. This is because if a large number of beams are projected at the same time by the same lens, the influence of the overlap on the processing is small.

  An interlace technique may be used instead of or in conjunction with simultaneously projecting multiple beams through the same lens. However, this may require more strict lens alignment. Accordingly, at least two beams projected onto the substrate at the same time through the same lens among these lenses have a mutual interval, and the apparatus is designed so that the subsequent beam projection is projected within the interval with respect to the optical column. The second actuator may be operated to move the substrate.

  In order to reduce the distance in the direction D between successive beams in one group (thus increasing the resolution in the direction D, for example), the beams are arranged obliquely with respect to the direction D. Also good. Such spacing may be further reduced by providing segment mirrors 30 in the optical path, each segment reflecting a corresponding one of the multiple beams. The segments are arranged so that the interval between the beams reflected by the mirrors is smaller than the interval between the beams incident on the mirrors. Such an effect can be realized by a plurality of optical fibers. In this case, each of the beams is incident on a corresponding one of the plurality of fibers, and the fibers are spaced apart from each other on the downstream side of the optical fiber rather than on the upstream side of the optical fiber along the optical path. Is arranged so as to narrow.

  Such an effect may also be realized using an integrated optical waveguide circuit having a plurality of inputs each receiving a corresponding one of the plurality of beams. The integrated optical waveguide circuit is configured such that the distance between the beams downstream of the integrated optical waveguide circuit is narrower than the distance between the beams upstream of the integrated optical waveguide circuit along the optical path. .

  A system for controlling the focus of the image projected onto the substrate may be provided. In the above-described configuration, a configuration for adjusting the focus of an image projected by a part or the whole of a certain optical column may be provided.

  In certain embodiments, the projection system may cause the material (eg, metal) by laser-induced material transfer by transferring at least one radiation beam to a substrate formed of a material layer above the substrate 17 on which the device is to be formed. Project to produce a local accumulation of droplets.

  Referring to FIG. 5, the physical mechanism of laser-induced material transfer is shown. In some embodiments, the radiation beam 200 is focused through a substantially transparent material 202 (eg, glass) with an intensity that is less than the plasma ignition of the material 202. Surface heat absorption occurs in a substrate formed from a donor material layer 204 (eg, a metal film) overlying material 202. This heat absorption causes the donor material 204 to melt. Heating also causes an induced pressure gradient in the forward direction that results in forward acceleration of the donor material drop 206 from the donor material layer 204, and thus from the donor structure (eg, plate) 208. Hence, the donor material drop 206 is released from the donor material layer 204 and moved onto the substrate (with or without gravity assistance) toward the substrate 17 on which the device is to be formed. By applying the beam 200 to the appropriate location on the donor plate 208, the donor material pattern can be deposited on the substrate 17. In some embodiments, the beam is focused on the donor material layer 204.

  In some embodiments, one or more short pulses are used to transport the donor material. In some embodiments, these pulses may be several picoseconds or several femtoseconds long to obtain quasi-one-dimensional forward heating and mass transfer of the molten material. Such short pulses cause little or no lateral heat flow in the material layer 204 so that there is little or no heat load on the donor structure 208. This short pulse allows for rapid melting and forward acceleration of the material (e.g., if the material such as metal is vaporized, the forward directionality resulting in sputter deposition will be lost). Short pulses allow material heating slightly above its melting temperature and below its vaporization temperature. For example, in the case of aluminum, a temperature of approximately 900 to 1000 degrees Celsius is desirable.

  In some embodiments, a quantity of material (eg, metal) is transferred from donor structure 208 to substrate 17 in the form of 100 nm to 1000 nm droplets by use of laser pulses. In certain embodiments, the donor material comprises or consists essentially of a metal. In some embodiments, the metal is aluminum. In some embodiments, the material layer 204 is film-like. In some embodiments, the film is attached to another body or layer. As mentioned above, the body or layer may be glass.

  FIG. 6 shows a section of the lithographic apparatus or exposure apparatus in cross section. A projection system module 310 is shown and includes all of the components supported by the frame 15 shown in FIG. In other words, the projection system module 310 includes optical components supported by the so-called metro frame 15. Another name for the projection system module 310 is the engine metro frame.

  The substrate table 2 is also shown in FIG. In one embodiment, the substrate table 2 is dynamically isolated from the projection system module 310. In a system using multiple radiation beams, such as in FIG. 1, the substrate W is usually quite large. In the plan view, the footprint of the substrate W can be significantly larger than the footprint of the projection system module 310. Therefore, a certain part of the substrate W may not be covered by the projection system module 310 as shown in FIGS.

  Difficulties are caused by the portion of the substrate W that is located on the substrate table 2 and not covered by the projection system module 310 (at least during imaging on some portions of the substrate). That is, the contaminant particles 340 can fall onto the upper surface of the substrate W when not covered by the projection system module 310. When the contaminant particles 340 fall on the substrate W, the formation of the pattern (for example, imaging of the projection beam) may be hindered, causing defects in the pattern on the substrate W. Thus, this situation is undesirable and steps are taken to reduce or minimize the possibility of contaminant particles reaching the substrate W.

  FIG. 6 shows how this can be done. One side of the projection system module 310 such that the first gas shower module 320 and the second gas shower module 330 provide gas flows 322, 332 (eg, gas showers) on the top surface of the substrate W not covered by the projection system module 310. And may be provided on the other side. The gas flow 322 to the upper surface of the substrate is provided through a series of openings 3222 in a two-dimensional array extending over the area of the substrate W existing below the first gas shower module 320. The second gas shower module 330 operates similarly. The first gas shower module 320 and the second gas shower module 330 are shown on the left and right sides of the projection system module 310 as shown in FIG. This is because the substrate W has the same width as the projection system module 310 in the Y direction (as shown in FIG. 7), but is longer than the projection system module 310 in the X direction. Accordingly, the first gas shower module 320 and the second gas shower module 330 are disposed on the front side and the rear side of the projection system module 310 in the X direction. In some embodiments, the first gas shower module 320 and the second gas shower module 330 may be a single gas shower module that extends around the projection system module 310.

  In order to help prevent the arrival and / or deposition of contaminant particles on the substrate W using the first gas shower module 320 and / or the second gas shower module 330, the gas shower (filtered gas Used) on the top surface of the substrate. The gas streams 322, 332 may be humidified gas and / or temperature-controlled gas so as to be useful for controlling the temperature of the substrate W. Gas flows 322, 332 can also be provided to the substrate table 2. Particles on or in the substrate table 2 will be prevented from reaching the substrate W.

  The first gas shower module 320 and the second gas shower module 330 may be the same or similar to those described in US Pat. No. 7,522,258, which is incorporated herein in its entirety.

  The first gas shower module 320 and the second gas shower module 330 are dynamically separated from the projection system module 310 to enter the projection system module 310 and avoid vibrations that adversely affect pattern formation (eg, imaging). Has been. As a result, a gap 305 exists on one side between the projection system module 310 and the first gas shower module 320 and on the other side between the projection system module 310 and the second gas shower module 330.

  Contaminant particles can fall through the gap 305 in the contaminant carrier gas stream 302 described in more detail with reference to FIG. Certain embodiments of the present invention address such potential sources of contaminant particles reaching the substrate.

  Contaminant carrier gas stream 302 on both sides of projection system module 310 generates a negative pressure in the subsequent flow due to the presence of gas streams 322, 332 in gas shower modules 320, 330 and / or movement of substrate table 2 And by drawing gas through gap 305). Others that could potentially generate a contaminant carrier gas stream 302 include inspection actions, opening of equipment covers or doors, exhaust particle extraction points (eg, negative pressure sources), (optional for components of projection system module 310) There is a thermally conditioned gas flow (as applied as a choice) and temperature differences between the components of the device.

  Another potentially more serious source of contaminant carrier gas stream 302 is substrate handler movement. In some embodiments, the first gas shower module 320 is also a substrate handler. The substrate handler is used to carry out and carry in the substrate from the carrying path through which the substrate W is delivered to the apparatus 1. Next, the substrate W is transferred to and placed on the substrate table 2 by the substrate handler (and then unloaded). The substrate handler moves in the Z direction to perform these tasks. During scanning of the substrate W, the substrate handler is positioned such that the outlet 3222 where the gas flow 322 exits the gas shower module 320 is at the same height as the outlet 3222 of the second gas shower module 330. Therefore, the handler being scanned is positioned as indicated by the solid line on the left side of FIG. During the transfer of the substrate W from the transport path and the substrate table 2, the handler 320 can be positioned as indicated by the broken line on the left side of FIG. Therefore, the first gas shower module 320 may move in the Z direction (direction parallel to the optical axis of the apparatus) as indicated by an arrow on the left side of FIG. Due to such vertical movement, a negative pressure is generated below the first gas shower module 320, particularly during the movement from the broken line position to the solid line position shown in FIG. 6 (ie, upward movement away from the substrate W), thereby A contaminant carrier gas stream 302 (shown in broken lines) may be drawn through the gap 305.

  FIG. 7 is a plan view showing the projection system module 310, the first gas shower module 320, the second gas shower module 330, and the substrate W (shown by cross-hatching).

  The gas shower defined by the gas flows 322, 332 generates a positive pressure above the substrate W and generates a certain outflow velocity on the side of the covered substrate W (by modules 310, 320, 330). These outflow velocities, illustrated by arrows 3221 and 3321 in FIG. 7, help prevent particles from entering the space above the substrate W. As shown in FIG. 7, the flow velocity in the gap 305 increases from the center toward the end. The resistance to the flow is small at the outside location. Since the flow velocity is large at the outer place in this way, the negative pressure is lowered at such a place, and the suction force acting on the gas above the gap 305 is increased. Thus, a larger contaminant carrier gas flow 302 is expected at the sides of the gap 305 than at the center (in plan view). If the substrate is not below the gap 305, the flow below the gap 305 tends to be more uniform along the length of the gap.

  In an embodiment, the substrate W below the projection system module 310 is not necessarily the same substrate W as the first gas shower module 320 or the second gas shower module 330.

  FIG. 8 shows in detail the gap 305 and the origin of the contaminant particles 340 on the upper surface of the substrate W supported by the substrate table 2. The illustrated gap 305 is a gap between the projection system module 310 and the first gas shower module 320, but the gap 305 on the other side of the projection system module 310 may be handled in the same manner. Contaminant carrier gas stream 302 carries contaminant particles 340 through gap 305. This can occur even when the gap 305 is narrowed by using the projection 307 installed on the projection system module 310.

  The contaminant carrier gas stream 302 may be generated by movement of the substrate table 2 that moves to some extent below the projection system module 310 and leaves a negative pressure in the downstream flow.

  When the substrate W is below the gap 305, for example, the contaminant particles 340 that are carried by the contaminant carrier gas flow 302 and find a path through the gap 305 can reach the upper surface of the substrate W. This can lead to patterning errors (eg imaging errors).

  One solution may be to provide a cover mechanism or a flexible seal mechanism between the first gas shower module 320 and the projection system module 310. However, such a cover may undesirably transmit a disturbance force between the two modules, and in itself, especially when movement (e.g. to accommodate the movement of the substrate handler) is necessary. It will be a source of particles. Another option might be a labyrinth seal, but at the cost of increasing complexity and requiring finer tolerances. Furthermore, in such systems, the substrate can be as wide as 3 meters, but it is not easy to design a seal that is sufficiently accurate and free of tolerance gaps in such long gaps.

  FIG. 9 illustrates an embodiment of the present invention that addresses one or more of the above-referenced or other difficulties. At least one gas seal outlet 325 is provided on the side wall of the gas shower module 320. The seal gas outlet 325 extends along the width of the first gas shower module 320, for example, along the Y direction. A gas flow 3255 (shown in dotted lines) is provided from the seal gas outlet 325. Seal gas flow 3255 is directed towards projection system module 310. As indicated by a single dotted line, certain components of the seal gas flow 3255 are directed away from the substrate W (eg, upward in the gap 305). In some embodiments, the seal gas stream 3255 is directed directly by the seal gas outlet 325 to have an upward component (eg, away from the substrate W). In addition or alternatively, in some embodiments, the seal gas stream 3255 is indirectly directed to have an upward component, eg, by hardware that directs the gas upward and opposite the gas exiting the seal gas outlet 325. Attached. Thereby, the seal gas stream 3255 bends the gas stream such that the contaminant carrier gas stream 3021 is directed away from the gap 305. Contaminant particles 340 are transported in the contaminant carrier gas stream 3021 away from the gap 305 and away from the substrate W. Seal gas stream 3255 provides a barrier to contaminant particles 340 in gap 305. The seal gas stream 3255 can help transport the contaminant particles 340, for example, out of the gap 305, particularly out of the top of the gap 305.

  The seal gas outlet 325 may be constructed and arranged (eg, oriented) such that the seal gas flow 3255 is directed to have a component away from the substrate W. As shown in FIG. 9, this is not essential. In some embodiments, the seal gas flow 3255 at the seal gas outlet 325 is directed so that the seal gas flow 3255 impinges perpendicularly to the surface of the protrusion 307. In addition, the seal gas flow 3255 may have a region that flows up and down with respect to the seal gas outlet 325.

  The seal gas outlet 325 may be a slit or a series of individual outlets. The length of the projection 307 effective for reducing the gap within the allowable range is at least equivalent to the amount of movement of the first gas shower module 320 in the Z direction (in the Z direction). In some embodiments, the seal gas flow 3255 impinges on the protrusion 307 regardless of the position of the first gas shower module 320.

  In some embodiments, there are no protrusions 307 and the seal gas stream 3255 strikes the surface of the projection system module 310 directly. In one embodiment, a seal gas outlet is formed in the projection system module 310 and in the first gas shower module 320 if a protrusion 307 is present.

  An exhaust opening 342 may be provided in the gap 305. In some embodiments, the exhaust opening 342 is on the top surface of the protrusion 307. In addition or alternatively, an exhaust opening may be present on the side wall of the projection system module 310 and / or the gas shower module 320. The exhaust opening 342 is attached to a negative pressure source. Thereby, the contaminant particles 340 approaching the exhaust opening 342 can be removed. For example, the velocity of the gas flow 3255 may be small at a distance close to the side wall of the projection system module 310 or gas shower module 320. As a result, the contaminant particles 340 can fall downward even if there is no downward flow 302.

  The upper surface of the protrusion 307 can serve as a particle collector. The negative pressure source to which the exhaust opening 342 is connected may be continuously on or may be activated periodically.

  The one or more exhaust openings 342 may be provided with the seal gas outlet 325 or may be provided without the seal gas outlet 325.

  Although the risk of the contaminant particles 340 falling into the gap 305 between the projection system module 310 and the second gas shower module 330 is small (since the second gas shower module 330 does not substantially move in the Z direction), see FIG. A configuration similar to that described above may be additionally or alternatively provided between the second gas shower module 330 and the projection system module 310.

  The gas provided from the seal gas outlet 325 is desirably a filtered gas, which may be humidified and / or temperature controlled therewith. The gas supplied from the seal gas outlet 325 may be the same as the gas supplied from the gas shower outlet 3222. The gas source is shown as gas source 3251 in FIG.

  The gap between the first gas shower module 320 and the projection 307 (or between the projection 307 and the projection system module 310 or between the projection 307 and the second gas shower module 330) may be as small as possible, but is about 5 to 20 mm. Typically, it may be about 10 mm.

  A controller 3252 is provided to control the flow rate of gas flowing out of the seal gas outlet 325 and / or into the exhaust opening 342. The gas flow is effective to prevent or transport the contaminant particles 340 away from the substrate W and out of the gap 305 between the projection system module 310 and the gas shower module 320.

  FIG. 10 shows an embodiment that is similar to the embodiment of FIG. 9 except the points described below. In FIG. 10, the deflector 350 is attached to the first gas shower module 320 above the protrusion 307. This creates a bent path that would be required for the contaminant particles 340 to be transported to fall onto the top surface of the substrate W. Further, the combination of the deflector 350 and the protrusion 307 is effective in narrowing or lengthening the narrow portion of the gap 305 between the projection system module 310 and the first gas shower module 320. This is effective in accelerating the seal gas stream 3255 away from the substrate W, and the contaminant carrier gas stream 3021 to transport the contaminant particles 340 to a location in the device that is not important, if any. It is effective for bending. In some embodiments, an exhaust pipe 341 connected to a negative pressure source is provided for collecting particles 340. The exhaust pipe 341 is controlled by the controller 3252. The deflector 350 may be an extension of the upper surface of the first gas shower module 320 or may protrude from the side wall of the gas shower module 320. In an embodiment, the deflector 350 is provided on the projection system module 310 or the gas shower module 320 where the projection 307 is not formed.

  FIG. 11 shows a further embodiment of the invention that is similar to the embodiment of FIG. 9 except as noted below.

  In the embodiment of FIG. 11, a turning gas outlet 312 is provided in the projection system module 310. The turning gas outlet 312 is provided below the protrusion 307 and / or below the seal gas outlet 325. A turning gas stream 3121 is provided from turning gas outlet 312. The gas exiting the outlet 312 is a filtered gas, for example under the control of the controller 3252. In some embodiments, the gas exiting the diverting gas outlet 312 is a humidified and / or temperature controlled gas.

  The diverted gas stream 3121 is provided in a direction having a component toward the gas shower module 320. Desirably, the diverted gas stream 3121 is located at a height below the bottom of the gas shower module 320. Contaminant particles 340 that have found their way through gap 305 can be deflected away from the top surface of substrate W by turning gas flow 3121. That is, the contaminant particles 340 are carried away from the projection system module 310 by the diverted gas stream 3121 and into the gas stream 322 of the gas shower module 320. The contaminant particles 340 are transported to the part of the device where the presence of the contaminant particles 340 is not critical.

  In one embodiment, the controller 3252 generates a gas flow from the turning gas outlet 312 when the substrate W is not below the gap 305 between the gas shower module 320 and the projection system module 310. That is, the turning gas flow 3121 is only present when the substrate table 2 is moving away from below the gap 305 as shown in FIG.

  A further embodiment is shown in FIG. The embodiment of FIG. 12 is based on a combination of the embodiments of FIGS. That is, the embodiment of FIG. 12 includes both a deflector 350 and a turning gas outlet 312. The operation of both components is the same as that described with reference to FIGS.

  Any of the concepts described above regarding the gap 305 between the projection system module 310 and the first gas shower module 320 are applied to the gap 305 between the projection system module 310 and the second gas shower module 330 singly or in any combination. Also good.

  As is apparent from the above, certain embodiments of the present invention provide, inter alia, a sealing gas outlet and associated gas flow between any two components of the device where passage of contaminant particles may not be desirable. May be.

  In a modification of the embodiment described above, a partition wall, for example, a stationary partition wall, may be provided in the gap 305. The sealing gas outlet (and optionally at least one of the turning gas outlet, protrusion, and deflector) is between the gas shower modules 320, 330 and the partition wall, and between the partition wall and the projection system module 310. May be provided.

  In an apparatus according to an embodiment of the invention, a plurality of radiation beams is divided into several distinct groups, each group being associated with a specific range of radiation wavelengths. Different responses of the dispersive elements for these different wavelengths are used to approximate these multiple radiation beams. However, the radiation beams associated with each group may exhibit different responses to each other as they pass through other optical elements within the projection system. Thus, in one embodiment, the projection system may include at least one color correction element, which is the response of the other optical elements other than the dispersion element of the projection system due to the wavelength difference between the radiation beam groups. Is configured to at least partially compensate for the difference in.

  For example, in the absence of color correction, there may be a focus error between the radiation beams of each radiation beam group. The color correction element may therefore be a piece of material appropriately selected to have a change in refractive index for each of the radiation wavelengths used to compensate for this error.

  Alternatively or additionally, such focus errors are caused by variations between the radiation wavelengths of the radiation beam groups, but the focus errors adjust the optical path length between the radiation source and the dispersive element of each radiation beam group. And may be minimized.

  The dispersive elements, and any color correction elements, if used, may be disposed in any number of different locations within the apparatus.

  In certain embodiments having a projection system with at least a stationary part and a moving part, a dispersive element may be mounted on the stationary part.

  In certain embodiments, the dispersive element may be arranged to be the first optical element in the projection system or one of the first several elements in the projection system. This disposition of the dispersive element can be advantageous in that the spacing between the multiple radiation beams is reduced in the construction of subsequent optical elements in the projection system.

  While embodiments of the present invention have been described above with reference to a dispersive element as part of the projection system, this is merely an exemplary configuration, and the dispersive element is provided elsewhere in the apparatus. It may be done. In some embodiments, the dispersive element includes a plurality of radiation sources configured to provide a plurality of radiation beams and one or more patterning devices configured to pattern the plurality of radiation beams. It may be provided between.

  In certain embodiments, when used, the color correction element may be the final optical element in the projection system, or one of the final elements.

  According to one device manufacturing method, a device such as a display, an integrated circuit, or any other item can be manufactured from a substrate on which a pattern is projected.

  Although this document describes the use of a lithographic apparatus or exposure apparatus in the manufacture of ICs as an example, it should be understood that the lithographic apparatus described herein can be applied to other applications. Other applications include integrated optical systems, magnetic domain memory guide and detection patterns, flat panel displays, liquid crystal displays (LCDs), thin film magnetic heads, and the like. For those other applications, those skilled in the art will consider that the terms "wafer" or "die" herein are considered synonymous with the more general terms "substrate" or "target portion", respectively. Will be able to understand. The substrates mentioned in this document are processed before or after exposure, for example by a track (typically a device that applies a resist layer to the substrate and develops the resist after exposure), a metrology tool, and / or an inspection tool. May be. Where applicable, the disclosure herein may be applied to these or other substrate processing apparatus. Also, the substrate may be processed multiple times, for example to produce a multi-layer IC, in which case the term substrate herein also means a substrate that already contains one or more processed layers. obtain.

  The term “lens” is any one of various optical components including refractive optical components, diffractive optical components, reflective optical components, magnetic optical components, electromagnetic optical components, and electrostatic optical components, as the context allows. Or a combination thereof.

  The above description is illustrative and is not intended to be limiting. Thus, it will be apparent to one skilled in the art that modifications may be made to the invention as described without departing from the scope of the claims set out below.

Claims (16)

A projection system module configured to project a radiation beam onto a substrate;
A gas shower module configured to provide a gas flow to the top surface of the substrate when not covered in plan view by the projection system module;
An exposure apparatus comprising: a seal gas outlet that provides a seal gas flow directed in a direction from the projection system module toward the gas shower module or vice versa.   The exposure apparatus according to claim 1, wherein the seal gas flow is directed upward.   The exposure apparatus according to claim 1, wherein the gas shower module includes a substrate handler configured to carry the substrate into a substrate table that supports the substrate.   The exposure apparatus according to claim 3, wherein the substrate handler is configured to move in a direction substantially parallel to an optical axis of the projection system module, and the seal gas outlet is attached to the substrate handler.   The exposure apparatus according to claim 1, wherein the projection system module or the gas shower module not provided with the seal gas outlet includes a protrusion to which the seal gas flow is directed.   The projection system module or the gas shower module provided with the seal gas outlet extends toward the projection system module or the gas shower module not provided with the seal gas outlet and is located above the gas outlet. The exposure apparatus according to claim 1, comprising a deflector attached to the exposure apparatus.   The exposure apparatus according to claim 1, further comprising a gas source that forms the gas flow on an upper surface of the substrate and forms the seal gas flow.   The exposure apparatus according to claim 7, wherein the gas source is a filtered gas source.   The exposure apparatus according to claim 7 or 8, wherein the gas source is a humidified and / or temperature-controlled gas source.   From the seal gas outlet so that the seal gas flow is effective to transport contaminant particles out of the gap between the projection system module and the gas shower module and / or away from the substrate. The exposure apparatus according to claim 1, further comprising a controller configured to control a gas flow rate.   11. The seal gas outlet according to any of claims 1 to 10, wherein the seal gas outlet comprises one or more outlets extending substantially in plan view along the lengths of opposing surfaces of the projection system module and the gas shower module. An exposure apparatus according to claim 1.   The turning gas outlet further comprising a turning gas outlet positioned at a height below the seal gas outlet in the projection system module and configured to provide a turning gas flow in a direction having a component toward the gas shower module. The exposure apparatus according to any one of 11 to 11.   The exposure according to claim 12, further comprising a controller configured to control a gas flow from the turning gas outlet to occur when there is no substrate below the gap between the gas shower module and the projection system module. apparatus.   The exposure apparatus according to claim 1, further comprising an exhaust opening connected to a negative pressure source.   The exposure apparatus according to claim 14, wherein the exhaust opening is formed in a gap between the projection system module and the gas shower module. Using a projection system module that projects a beam of radiation onto a substrate;
Using a gas shower module that provides gas flow to the top surface of the substrate when not covered in plan view by the projection system module;
Providing a sealing gas flow directed in a direction from the projection system module toward the gas shower module or vice versa.

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