JP2006135180A - Device and method for measuring optical characteristics, exposing apparatus, exposing method, and device manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical characteristics measuring apparatus not impairing the motility of a movement stage owing to a cable in an optical apparatus. <P>SOLUTION: The optical characteristics measuring apparatus 2 includes a wavefront aberration measuring unit 35 disposed on a wafer stage WST for measuring the wavefront aberration of an optical system of the exposing apparatus, and a cable control device for controlling the operation of the cable 4 connected to the wavefront aberration measuring unit 35 while matching the operation of the wafer stage WST. Even when the wafer stage WST moves, the cable 4 does not impair its motility. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical characteristic measuring apparatus, an optical characteristic measuring method, an exposure apparatus, an exposure method, and a device manufacturing method.

  Conventionally, devices have been manufactured using an exposure apparatus. For example, in this exposure apparatus, a reticle or photomask on which a pattern is formed is placed on a stage that can move in the scanning direction, and exposure light is irradiated onto the reticle or photomask from an illumination optical system. Then, the pattern is projected onto a substrate such as a wafer or a glass plate placed on a stage movable in the XY directions by a projection optical system. At this time, devices such as a semiconductor element, a liquid crystal display element, an imaging element, and a thin film magnetic head are manufactured by scanning both the reticle stage and the wafer stage in synchronization.

  By the way, in recent years, further increase in the density of semiconductor devices and the like has progressed, and accordingly, circuit patterns manufactured by an exposure apparatus have been required to be miniaturized. As the density of such semiconductor devices increases, the exposure accuracy of the exposure apparatus has a greater effect on the accuracy of the semiconductor device. In such an exposure apparatus, for example, the optical characteristics are carefully adjusted by a measuring apparatus having a wavefront measuring function. This measuring apparatus is attached to a stage on which a reticle or wafer is placed.

On the other hand, cases of producing large-sized devices such as liquid crystal display devices and cases of producing a large number of semiconductor devices on a large wafer having a diameter of 300 mm are increasing. In this case, in order to increase productivity, It becomes necessary to move the wafer stage at a higher speed. Therefore, in order to maximize the motion characteristics of the stage during normal operation, efforts have been made to increase the stage performance by reducing the inertial mass in units of 1 gram by making it possible to detach a mechanism that is not normally used, particularly a measuring device. For example, Patent Document 1 describes a configuration in which a measurement unit, which is a sensor portion for measuring wavefront aberration for detecting wavefront aberration of a projection optical system, is detachably attached to a recess formed in a wafer stage. Yes.
International Publication No. WO99 / 60361 Pamphlet

  However, a power cable for operating the measurement unit itself, an output cable for outputting a measurement result, and the like are attached to the measurement unit. Each of these cables needs to have a length considering the maximum movable range of the wafer stage, and its mass is often in the order of kilograms. Therefore, when moving the stage equipped with the measurement unit, the mobility of the stage may be deteriorated not only by the mass of the measurement unit but also by the mass of each cable.

  Also, in recent exposure apparatuses, various auxiliary machines are attached around the stage, and a space for routing the cable cannot be secured sufficiently. In such a situation, if there is a cable having a length that takes into account the maximum movable range of the wafer stage, the cable may come into contact with surrounding accessories when the stage is moved.

  It is possible to attach a winding mechanism with a constant tension, such as a power cord for a vacuum cleaner, to the measuring device. However, a large tension is necessary for stable winding, and the stage movement is still necessary. There was a problem of worsening sex.

It is an object of the present invention to provide an optical characteristic measuring apparatus that is arranged on a moving stage and that does not impair the mobility of the moving stage with a cable.
Another object of the present invention is to provide an optical characteristic measurement method for measuring optical characteristics using the optical characteristic measurement apparatus, an exposure apparatus provided with the optical characteristic measurement apparatus, an exposure method using the exposure apparatus, and manufacture of a device. To provide a method.

  In order to achieve the above object, in the optical property measuring apparatus according to claim 1, in the optical property measuring apparatus for measuring the optical property of the optical system, a measuring unit disposed on the moving stage and measuring the optical property of the optical system; And a cable control device for controlling the operation of the cable connected to the measurement unit in accordance with the operation of the moving stage.

  In the optical characteristic measuring apparatus having this configuration, the operation of the cable connected to the measurement unit is controlled in accordance with the operation of the moving stage, so that the presence of the cable does not hinder the movement of the moving stage. Therefore, there is an effect that the moving stage can be moved to an accurate position.

    In the optical characteristic measuring apparatus according to claim 2, in the optical characteristic measuring apparatus according to claim 1, the optical system measured by the optical characteristic measuring apparatus is an optical system of an exposure apparatus, and the moving stage is an optical apparatus of the exposure apparatus. The gist is that it is a wafer stage or a reticle stage.

  In the optical characteristic measuring apparatus of this configuration, since the cable connected to the measuring unit arranged on the wafer stage or the reticle stage is controlled particularly in an exposure apparatus with severe optical conditions, accurate exposure is performed regardless of the presence of the cable. There is an effect that can be performed.

    According to a third aspect of the present invention, there is provided an optical characteristic measuring apparatus according to the first or second aspect, wherein the cable control device is fixed outside the moving stage.

  In the optical property measuring apparatus having this configuration, only a measurement unit having a relatively small mass is generally provided on the moving stage, and a cable control device having a relatively large mass is not disposed on the moving stage. Furthermore, since the cable is controlled by the cable control device, the moving stage has an effect that it can move to an accurate position without deteriorating the mobility of the stage.

    The optical property measurement apparatus according to claim 4 is the optical property measurement apparatus according to any one of claims 1 to 3, wherein the optical property measurement apparatus includes a wavefront measurement function, a polarization measurement function, and an illumination shape measurement. The gist is that at least one of a function, a lens aperture shape measurement function, and an illumination illuminance measurement function is provided.

  By placing an optical property measurement device on the stage with at least one of a wavefront measurement function, polarization measurement function, illumination shape measurement function, lens aperture shape measurement function, and illumination illuminance measurement function, the measurement accuracy of the optical system can be improved. In addition to the improvement, there is an effect that the movement of the moving stage is not hindered by the cable control device.

    The optical property measuring apparatus according to claim 5 is the optical property measuring apparatus according to any one of claims 2 to 4, wherein the optical property measuring apparatus is configured to be detachable from the exposure apparatus. Is the gist.

  Since the optical characteristic measuring apparatus having this configuration is configured to be detachable from the moving stage, it can be removed when not needed, and when necessary, the moving stage can be moved by the cable even if it is mounted on the moving stage. There is an effect that the cable is not damaged or the cable does not interfere around the moving stage.

    The optical characteristic measuring apparatus according to claim 6 is the optical characteristic measuring apparatus according to any one of claims 1 to 5, wherein the cable control device is based on an instruction value for movement control of the moving stage. The gist is to control the cable.

In the optical characteristic measuring apparatus having this configuration, since the cable is controlled based on the instruction value for movement control, there is an effect that there is no control delay and that appropriate control can be performed.
The optical property measurement apparatus according to claim 7 is the optical property measurement apparatus according to any one of claims 1 to 6, wherein the cable control device is based on a measurement value obtained by measuring the movement of the movable stage. The gist is to control the cable.

  In the optical characteristic measuring apparatus having this configuration, since the cable is controlled based on the measurement value obtained by measuring the movement of the moving stage, there is an effect that the cable can be controlled in accordance with the actual movement of the moving stage.

    The optical characteristic measuring apparatus according to claim 8 is the optical characteristic measuring apparatus according to any one of claims 1 to 7, wherein the cable control device requires the cable in accordance with the operation of the moving stage. The gist is provided with a cable length adjusting means for adjusting the length.

  In the optical characteristic measuring apparatus having this configuration, the necessary length of the cable is adjusted in accordance with the operation of the moving stage, and therefore, there is an effect that unnecessary tension is not applied to the cable and the cable is not unnecessarily loosened. .

    The optical characteristic measuring apparatus according to claim 9 is the optical characteristic measuring apparatus according to claim 8, wherein the cable length adjusting means extends or retracts the cable in accordance with the operation of the moving stage. The gist is to adjust.

  In the optical characteristic measuring apparatus having this configuration, the cable length can be adjusted so that unnecessary tension is not applied to the moving stage by actively feeding or drawing the cable in accordance with the operation of the moving stage. There is an effect.

    In the optical property measuring apparatus according to claim 10, in the optical property measuring apparatus according to claim 8, the cable control device performs automatic winding by applying tension to the cable, and adjusts to the operation of the moving stage. Cable tension adjusting means for controlling the operation of the cable by decreasing the tension when the moving stage moves away from the cable fixing point and increasing the tension when the moving stage approaches the cable fixing point. This is the gist.

  In the optical characteristic measuring apparatus of this configuration, the tension applied to the cable is adjusted according to the movement of the moving stage, so that the force applied to the cable can be made constant and the movement of the moving stage can be stabilized. is there.

    The optical property measurement apparatus according to claim 11 is the optical property measurement apparatus according to any one of claims 8 to 10, wherein the cable length adjusting means is configured to adjust the cable length according to the position of the stage. The gist is that a swing mechanism for changing the feeding or drawing direction is provided.

  Since the optical characteristic measuring apparatus having this configuration includes the swing mechanism that changes the direction of drawing or drawing the cable in accordance with the position of the stage, there is an effect that the cable can be drawn or drawn more smoothly.

    The optical property measurement apparatus according to claim 12 is the optical property measurement apparatus according to any one of claims 1 to 11, wherein the cable control device has rigidity according to the operation of the moving stage. The gist is to control the operation of the arm to guide the cable to the target position.

  In the optical characteristic measuring apparatus having this configuration, the arm having rigidity guides the cable to the target position, so that the arm can support the mass of the cable and the force applied to the moving stage can be reduced. .

    An optical property measuring apparatus according to a thirteenth aspect is the optical characteristic measuring device according to the twelfth aspect, wherein the arm includes an extendable main body, and the cable is built in the main body.

  In the optical characteristic measuring apparatus of this configuration, since the cable is built in the extendable body, the cable is not exposed to the outside, and the cable does not interfere with the surroundings even if the moving stage moves. is there.

    An optical property measuring apparatus according to a fourteenth aspect is the optical characteristic measuring device according to the twelfth aspect, wherein the arm is configured as a robot arm having a bendable joint.

  In the optical characteristic measuring apparatus having this configuration, since the arm is configured as a robot arm having an inflexible arm, the cable can be guided without being expanded or contracted.

The gist of an optical characteristic measuring method according to a fifteenth aspect is to measure the optical characteristic of the optical system using the optical characteristic measuring apparatus according to any one of the first to fourteenth aspects.
With the optical characteristic measuring apparatus having this configuration, accurate measurement can be performed on the moving stage, and the operation of the cable is also controlled by the movement of the moving stage, so that there is an effect that the measurement is not adversely affected by the cable.

    The exposure apparatus according to claim 16 is an exposure apparatus that exposes a pattern image formed on a mask on a reticle stage onto a substrate on a wafer stage via a projection optical system. The gist is that the optical characteristic measuring device according to any one of the above items is provided.

The exposure apparatus having this configuration has an effect that exposure with high accuracy can be performed based on accurate measurement.
The gist of the exposure method according to claim 17 is that the exposure apparatus according to claim 16 is used for exposure based on the optical characteristics of the optical system measured by the optical characteristic measurement apparatus.

With the exposure method having this configuration, there is an effect that exposure with high accuracy can be performed based on accurate measurement.
The device manufacturing method according to claim 18 is characterized in that, in the device manufacturing method including a lithography step, exposure is performed using the exposure apparatus according to claim 16 in the lithography step.

  In the device manufacturing method having this configuration, it is possible to perform high-accuracy exposure based on accurate measurement and to manufacture a high-quality device.

  According to the present invention, in the optical characteristic measuring apparatus for measuring optical characteristics, there is an effect that the mobility of the moving stage is not impaired by the cable.

  (First Embodiment) FIG. 1 shows an embodiment in which the present invention is embodied as an optical characteristic measuring apparatus 2 for measuring wavefront aberration in a scanning exposure type exposure apparatus 1 capable of scanning exposure for manufacturing semiconductor elements. It demonstrates based on 1-3.

FIG. 1 is a diagram illustrating a schematic configuration of the exposure apparatus 1. Hereinafter, the configuration of the exposure apparatus 1 will be described with reference to FIG.
First, the illumination optical system 17 of the exposure apparatus 1 will be described. The exposure light source 11 emits, for example, pulsed light such as KrF excimer laser light, ArF excimer laser light, and F ₂ excimer laser light as the exposure light EL. As an optical integrator, the exposure light EL enters, for example, a fly-eye lens 12 composed of a large number of lens elements, and a large number of secondary light source images corresponding to the respective lens elements are formed on the exit surface of the fly-eye lens 12. The Note that the optical integrator may be a rod lens. The exposure light EL emitted from the fly-eye lens 12 has a circuit pattern such as a semiconductor element drawn through the relay lenses 13a and 13b, the reticle blind 14, the mirror 15, and the condenser lens 16, and is placed on the reticle stage RST. It enters the reticle R as a mask.

  Here, the synthesis system of the fly-eye lens 12, the relay lenses 13a and 13b, the mirror 15, and the condenser lens 16 superimposes the secondary light source image on the reticle R, and illuminates the reticle R with uniform illuminance 17. Is configured. The reticle blind 14 is arranged such that its light shielding surface has a conjugate relationship with the pattern area of the reticle R. The reticle blind 14 includes a plurality of movable light-shielding portions (for example, two L-shaped movable light-shielding portions) that can be opened and closed by a reticle blind drive unit 14a. And the illumination area which illuminates reticle R is arbitrarily set by adjusting the magnitude | size (slit width etc.) of the opening part formed by those movable light-shielding parts.

  Next, reticle stage RST will be described. The reticle stage RST is arranged on a surface plate (not shown) of the exposure apparatus 1 and holds the reticle R in a plane perpendicular to the optical axis AX of the exposure light EL so that it can be finely moved in a two-dimensional direction. The reticle stage RST can be moved in a predetermined direction (scanning direction (Y direction)) by a reticle stage driving unit 19 constituted by a linear motor or the like. Reticle stage RST has a moving stroke that allows the entire surface of reticle R to cross at least optical axis AX of exposure light EL. In FIG. 1, the direction along the optical axis of the projection optical system PL described later is the Z direction, the direction orthogonal to the optical axis of the projection optical system PL and the paper surface is the X direction, and is orthogonal to the optical axis of the projection optical system PL. The direction along the paper surface is defined as the Y direction.

  A Y-axis interferometer 20 that measures the distance in the Y-axis direction and an X-axis interferometer (not shown) that measures the distance in the X-axis direction are arranged on the surface plate that supports the moving reticle stage RST. A Y-axis moving mirror 21 that reflects the laser beam from the Y-axis interferometer 20 and an X-axis moving mirror (not shown) that reflects the laser beam from the X-axis interferometer are fixed to the end of the reticle stage RST. ing. The Y-axis interferometer 20 always detects the position of the reticle stage RST in the scanning direction, and the X-axis interferometer always detects the position of the reticle stage RST in the direction orthogonal to the scanning direction. It is sent to the reticle stage control unit 22. The reticle stage control unit 22 controls the reticle stage driving unit 19 based on the position information of the reticle stage RST, and moves the reticle stage RST.

  Next, the projection optical system PL will be described. The exposure light EL that has passed through the reticle R is incident on, for example, a bilateral telecentric projection optical system PL. The projection optical system PL is a substrate in which a projection image obtained by reducing the circuit pattern on the reticle R to, for example, 1/5 or 1/4 is coated on the surface with a photoresist having photosensitivity to the exposure light EL. Formed on the wafer W.

  Subsequently, wafer stage WST will be described. Wafer W is sucked and held on wafer stage WST through wafer holder 25 equipped with a vacuum device. It is possible to hold a glass substrate or the like as well as the silicon wafer. The wafer holder 25 can be tilted in an arbitrary direction with respect to the optimal imaging plane of the projection optical system PL by a drive unit (not shown), and the optical axis AX direction (Z direction) and the optical axis AX (Z axis) of the projection optical system PL. The surrounding rotation can be finely moved. Wafer stage WST is perpendicular to the scanning direction so that it can be moved not only in the scanning direction (Y direction) but also in a plurality of shot areas partitioned on the wafer by wafer stage driving unit 26 such as a motor. It is configured to be movable also in the direction (X direction). That is, the wafer stage WST is given six degrees of freedom and can accurately introduce the wafer W into the image plane. A step-and-repeat operation that repeats batch exposure for each shot area on the wafer W and a step-and-scan operation that repeats scanning exposure are possible.

  On the surface plate 23 outside the moving wafer stage WST, an interferometer comprising an X-axis interferometer 27x for measuring the distance in the X direction and a Y-axis interferometer 27y (see FIG. 3) for measuring the distance in the Y-axis direction. 27 is arranged. Further, the movable mirror 28 composed of an X-axis movable mirror 28x and a Y-axis movable mirror 28y (see FIG. 3) that respectively reflect the laser beams from these interferometers is fixed to the end of the wafer stage WST on which the movable mirror 28 moves. Yes. The position of wafer stage WST in the X direction and the Y direction is always detected by interferometer 27. The position information (or speed information) of wafer stage WST is sent to wafer stage control unit 29, and wafer stage control unit 29 controls wafer stage drive unit 26 based on this position information (or speed information).

  On wafer stage WST, a measurement unit for optical characteristics is provided. As the measurement unit of the present invention, for example, an optical characteristic measurement device having a wavefront measurement function can be considered. Here, in the present embodiment, the measurement unit will be described using a wavefront aberration measuring apparatus that measures wavefront aberration as an example. The moving stage of the present invention is not limited to wafer stage WST, but also includes reticle stage RST. In the present embodiment, the moving stage will be described using the wafer stage WST as a representative.

  A wavefront aberration measuring unit 35 for detecting the wavefront aberration of the projection optical system PL is detachably attached to the mounting recess 34 as the optical characteristic measuring apparatus 2 of the present embodiment. The wavefront aberration measurement unit 35 is arranged so that the height of the light receiving surface 36 substantially coincides with the height of the surface of the wafer W. For this reason, the wavefront aberration can be accurately measured under substantially the same conditions as the surface of the wafer W during the measurement operation. When the wavefront aberration measurement unit 35 is removed when the measurement is finished and the operation is shifted to the exposure operation, the cable used for the wiring is not left on the wafer stage WST, and the inertial mass is reduced.

  As shown in FIG. 2, a collimator lens 37, a microlens array 38, and a CCD 39, which is an image sensor, are provided inside the wavefront aberration measurement unit 35. The collimator lens 37 converts a light beam incident from the light receiving surface 36 into the wavefront aberration measuring unit 35 into parallel light PB. The microlens array 38 has microlenses arranged two-dimensionally, divides the parallel light PB into a plurality of light beams, and collects the divided light beams for each lens. The CCD 39 has a sufficient area to receive all the light beams passing through the light receiving surface 36, and detects the position of the condensing point (imaging position) for each lens. Then, the CCD 39 outputs a signal relating to the position of each received condensing point to the wavefront aberration detector 40.

  This wavefront aberration detector 40 calculates the wavefront aberration of the projection optical system PL based on the input position information of each condensing point, and controls the operation of the entire exposure apparatus using the information on the calculated wavefront aberration. Output to the control system 41. As described above, the wavefront aberration measuring unit 35 and the wavefront aberration detecting unit 40 constitute a measuring means.

  The wavefront aberration measurement unit 35 and the wavefront aberration detector 40 are connected via the cable 4 and the cable control device 3. Here, the cable 4 will be described in detail. An electrical signal is sent from the CCD 39 in accordance with the intensity of light received by the CCD 39. This electric signal is once transmitted by internal cable 4a to relay unit 4c arranged on wafer stage WST. Here, the internal cable 4a is mechanically fixed to the relay portion 4c. The internal cable 4a is connected to the external cable 4b here. Depending on the type of measurement unit on the stage, an optical cable other than an electrical cable may be used, and a power supply, gas, liquid, or the like necessary for the operation of the measurement unit may be supplied.

  Here, FIG. 3 is a perspective view schematically showing the configuration of the optical property measuring apparatus 2 of the first embodiment. The optical characteristic measurement device 2 of the present embodiment is configured to include the wavefront aberration measurement unit 35 and the cable control device 3 described above. The cable control device 3 includes a take-up reel 54 that winds the cable 4b, a motor 55 that rotates the take-up reel 54, and a turntable 56 that rotates these in a horizontal plane, and is fixed outside the moving wafer stage WST. It is installed on the surface plate 23 which is a part.

  The cable take-up reel 54 is formed in a reel shape capable of taking up the cable 4b as cable length adjusting means, and the end of the cable 4b is electrically connected and mechanically fixed. The cable take-up reel 54 includes a motor 55 and is configured to be able to rotate forward and backward so as to take up or pull out the cable 4b. In addition, the structure provided with the tensioner which cannot apply the slight tension as a guide for cable alignment which is not shown in figure, and applies a slight tension as a cable tension adjustment means is preferable.

  In addition, for example, the linear encoder that reads the scale on the cable 4b and reads the scale, the rotary encoder that detects the pulled state of the cable 4b by the rotation of the roller in contact with the cable 4b, and the like, the drawing amount of the cable 4b is optical, Those that can be detected magnetically and mechanically are desirable. Further, in the case where high accuracy is not required, a configuration provided with a rotary encoder that easily detects the amount of the cable 4b drawn by the rotation of the cable take-up reel 54 or the motor 55 itself may be used.

  The turntable 56 supports the take-up reel 54 so that the take-up reel 54 can rotate about the vertical axis. As will be described later, this rotation is actively and accurately performed in the direction of the wavefront aberration measuring unit 35 by a motor (not shown) built in the direction controlled by the main control system 41 and the cable control unit 57. Orient the take-up reel 54. However, depending on the accuracy required, one end may be routed by the cable 4b connected to the wavefront aberration measurement unit 35 to passively change the direction.

  The cable 4b connected to the take-up reel 54 is further connected to the main control system 41 via the take-up reel 54, and an electric signal from the CCD 39 (see FIG. 2) of the wavefront aberration measuring unit 35 is sent to the main control system 41. Send to.

  Further, the position of wafer stage WST in the X direction and the Y direction is always detected by interferometer 27 (FIG. 2), and the position information (or speed information) of wafer stage WST is sent to main control system via wafer stage control unit 29. 41. On the other hand, the state of the cable 4 b detected by the encoder or the like is also input from the cable control device 3 to the main control system 41. Based on the position information of wafer stage WST and the detection result of the encoder, the position information of relay unit 4c with respect to cable control device 3 is obtained.

  The main control system 41 calculates the distance and direction from the cable control device 3 to the relay unit 4c based on the position information of the wavefront aberration measuring unit 35, more specifically, the relay unit 4c. Then, the cable control device 3 calculates how much the cable is to be drawn in which direction, and transmits a control signal so as to send a drive signal to the cable drive unit 58 according to the result. The cable drive unit 58 sends drive signals to the motor 55 and the motor of the turntable 56 to control the amount of drawing or winding of the cable 4.

  By controlling the cable control device 3 in this way, the cable 4 is always drawn out or wound up by a necessary amount. Thus, since the required length of the cable 4 is adjusted according to the operation of the wafer stage WST, unnecessary tension is not applied to the cable and the cable is not unnecessarily loosened.

  The main control system 41 stores sequential information regarding the movement of the wafer stage WST, so that the cable control by the cable control device 3 is also performed, such as the inertia of the take-up reel 54 when the moving direction is reversed. It is desirable to make the control considering the above. For example, when the wavefront aberration measuring unit 35 is closest and then separated again, the take-up reel 54 is expected to be reversed. In this case, control is performed such that driving of the take-up reel 54 in the take-up direction is stopped before the closest approach timing, and the stop timing due to the inertia of the take-up reel 54 is synchronized with the closest approach of the wavefront aberration measuring unit 35. There is a way.

Next, a method for measuring the wavefront aberration of the projection optical system PL will be described.
First, as shown in FIGS. 1 and 2, a test reticle Rt in which a pinhole PH having a predetermined diameter as a pinhole pattern is formed is placed on the reticle stage RST. Next, the light receiving surface 36 of the wavefront aberration measuring unit 35 is caused to correspond to the projection area of the projection optical system PL by the wafer stage driving unit 26. At this time, in accordance with the movement of the wavefront aberration measuring unit 35 that moves together with the wafer stage WST, the turntable 56 rotates to align the take-up reel 54 toward the wavefront aberration measuring unit 35, and the take-up reel 54 The length of the cable 4 is adjusted by being rotated by the motor 55 according to the distance to the wavefront aberration measuring unit 35. For this reason, the cable 4 is given a tension that allows a slight sag, and is not subjected to an excessive tension, and a force that prevents the movement of wafer stage WST is generated unless the weight of cable 4 is removed. . In addition, since an unnecessarily long margin is not generated, the cable 4 is not loosened such as a large sag, and the cable 4 does not come into contact with the surroundings.

  In this state, measurement light RL, which is exposure light for measurement, is emitted from exposure light source 11 and irradiated to pinhole PH on test reticle Rt via relay lenses 13a and 13b, mirror 33, and condenser lens 16. By passing through the pinhole PH, the measurement light RL is converted into light having a spherical wave SW. The light having the spherical wave SW is incident on the projection optical system PL, and when the aberration remains in the projection optical system PL, the wavefront WF of the spherical wave SW is distorted.

  As shown in FIG. 2, the light having the spherical wave SW emitted from the projection optical system PL reaches the light receiving surface 36 of the wavefront aberration measuring unit 35 and enters the wavefront aberration measuring unit 35. The light having the spherical wave SW incident inside the wavefront aberration measuring unit 35 is converted into parallel light PB by the collimator lens 37. Here, when there is no aberration in the projection optical system PL, the wavefront WF of the parallel light PB is a plane. On the other hand, when the projection optical system PL has an aberration, the wavefront WF of the parallel light PB is a distorted surface. The parallel light PB is divided into a plurality of light beams by the microlens array 38 and condensed on the CCD 39. Here, when there is no aberration in the projection optical system PL, since the wavefront of the parallel light PB is a plane, the parallel light PB is incident along the optical axis of each lens. Exists on the optical axis of each lens. On the other hand, when the projection optical system PL has an aberration, the wavefront of the parallel light PB becomes a distorted surface. Therefore, the parallel light PB incident on each lens has a different wavefront inclination for each lens. Have In connection with this, the condensing spot for each lens exists on the perpendicular to the inclination of the wavefront, and shifts laterally with respect to the condensing spot when there is no aberration. The position of each laterally condensed light spot is detected by the CCD 39.

  Next, in the wavefront aberration detection unit 40 shown in FIG. 1, the position of the condensing spot when there is no aberration in the projection optical system given in design, and the CCD 39 condensed through the projection optical system PL. The lateral deviation amount is obtained by comparing with the focused spot position, and the wavefront aberration in the projection optical system PL is measured. In this case, the light receiving surface 36 of the wavefront aberration measuring unit 35 held on the wafer stage WST is arranged so as to be on the same plane as the wafer W. Similar wavefront aberration can be measured.

  (Second Embodiment) Next, an optical characteristic measuring apparatus 102 which is another embodiment of the optical characteristic measuring apparatus of the present invention will be described with reference to FIG. In addition, in order to avoid duplication of description, only a different part from 1st Embodiment is demonstrated, the description of the same or equivalent structure is abbreviate | omitted, or attaches | subjects the same number and description is abbreviate | omitted.

  The wavefront aberration measuring unit 35 in the optical characteristic measuring apparatus 102 shown in FIG. 4 is basically the same as that in the first embodiment, and the cable control apparatus 103 is different in configuration from the first embodiment. The take-up reel 154 rotates about a vertical axis, and the motor 155 drives it so that it can rotate forward and backward. Although the turntable 156 may be actively rotated, in the present embodiment, since the necessity thereof is low, the cable 4 is guided by the guide 157. In the control of the take-up reel 154, the feeding distance of the cable 4 is calculated by the main control system 41 as in the first embodiment. The cable control device 103 applies a predetermined tension to the cable 4 by the motor 155. Therefore, the length of the cable 4 to the wavefront aberration measuring unit 35 is calculated, and when the wavefront aberration measuring unit 35 is separated from the cable control device 3, the urging force from the motor 155 is reduced, and the cable 4 is taken up by the winding reel 154. The cable 4 is not resisted from being drawn out, the tension of the cable 4 is prevented from increasing, and the tension is kept constant. On the other hand, when the wavefront aberration measurement unit 35 is close to the cable control device 3, the urging force from the motor 155 is increased so that the cable 4 is not resisted by the take-up reel 154 and the tension of the cable 4 is reduced. The rise is prevented and the tension is kept constant. In this way, the cable control unit 57 adjusts the wafer stage WST at one fixed point of the cable 4 in accordance with the operation of the moving wafer stage WST predicted in advance from the movement control program for the wafer stage WST of the main control system 41. When moving relatively away from a certain cable control device 3, the tension is reduced. On the other hand, when wafer stage WST is relatively close to cable control device 3, the tension is controlled to be increased.

  By performing such control, the tension applied to the cable 4 is kept constant, and the mobility of the wafer stage WST when the cable 4 is pulled out is not particularly impaired. Further, since unnecessary bending is eliminated, it is possible to effectively prevent the cable 4 from interfering with the surroundings.

  Since the movement of wafer stage WST is used for feeding out cable 4, the tension is relatively large as compared with the first embodiment, but the configuration can be simplified.

(Third embodiment)
Next, an optical characteristic measuring apparatus 202 which is another embodiment of the optical characteristic measuring apparatus of the present invention will be described with reference to FIGS. In addition, in order to avoid duplication of description, only a different part from 1st Embodiment is demonstrated, the description of the same or equivalent structure is abbreviate | omitted, or attaches | subjects the same number and description is abbreviate | omitted.

    In the optical characteristic measuring apparatus 202, the guide rod 204 having the rigidity of the cable control device 203 in accordance with the operation of the wafer stage WST is controlled by the cable control unit 57 to guide the cable 4 to the target position.

  As shown in FIG. 6, the guide rod 204 is a combination of a plurality of cylindrical members having different diameters and slides on each other, and the overall length is variable as shown in FIG. The cable 4 is inserted into the guide rod 204. The guide rod 204 has a base portion supported by a guide rod support portion 205, and the guide rod support portion 205 is fixed to the turntable 206. The turntable 206 is configured to freely rotate forward and backward about a vertical axis, and a main control system is configured so that the distal end direction of the guide rod 204 is directed toward the wavefront aberration measurement unit 35 by a built-in motor (not shown). 41, controlled by a cable control unit 57 (see FIG. 1).

  The flexible cable 4 is exposed from the tip of the guide rod 204, and the cable 4 is connected to the wavefront aberration measurement unit 35. Note that it is preferable that only the tip portion of the cable 4 is made of a particularly soft material so that the force and vibration from the guide rod 204 are not transmitted to the wafer stage WST. Further, with this configuration, even if the position control of the guide rod 204 is rough, the position error is absorbed by the tip end portion of the cable 4, so that the mobility of the wafer stage WST is not impaired.

  FIG. 7 is a cross-sectional view of the main part along the longitudinal direction showing the inside of the guide rod support part 205 and the tip part of the guide rod 204. The guide rod support portion 205 includes a take-up reel 207 inside and takes up and stores the cable 4. The take-up reel 207 can take up and feed out the cable 4 by a motor 210 (see FIG. 5). The cable 4 drawn out from the take-up reel 207 is guided by a plurality of guide rollers 208 and is fed by a motor controlled by a main control system 41 and a cable control unit 57 (see FIG. 1). Thus, the speed and amount of winding and feeding to the take-up reel 207 are accurately regulated so that the calculated feeding amount is obtained. The feed amount is read by a scale marked on the cable 4 by the optical encoder 211 and fed back to the main control system 41. The distal end portion of the guide rod 204 is fixed to the cable 4, and the guide rod 204 expands and contracts by the cable 4 whose feeding amount is adjusted, and supports the own weight of the cable 4. The cable 4 protruding from the tip of the guide rod 204 is directly connected to the wavefront aberration measuring unit 35 (or via a relay unit (not shown)), but is connected to the wavefront aberration measuring unit 35 (or the relay provided on the wafer stage WST). Part) is hardly applied with tension, and the weight of the cable 4 is not applied. Therefore, the cable 4 can be guided without impairing the mobility of the wafer stage WST. Since the guide rod 204 having rigidity is not connected to the wavefront aberration measuring unit 35 (or the relay portion), but is connected only by the cable 4 having flexibility, the guide rod 204 itself No abnormal tension is caused by vibration or position error. Further, since the cable 4 is hardly exposed to the outside of the rigid guide rod 204, even if the wafer stage WST moves, the cable 4 does not shake greatly, and the exposure apparatus around the wafer stage WST does not move. There is an effect that there is no interference with auxiliary equipment. Further, auxiliary equipment can be provided in the vicinity of wafer stage WST, and the design of the exposure apparatus itself can be made compact.

  Further, by making the guide rod 204 made of metal, the guide rod 204 itself can be used for transmitting an electric signal, and noise can be prevented by a shielding effect.

  (Fourth Embodiment) Next, an optical characteristic measuring apparatus 301 which is another embodiment of the optical characteristic measuring apparatus of the present invention will be described with reference to FIGS. In addition, in order to avoid duplication of description, only a different part from 3rd Embodiment is demonstrated, the description of the same or equivalent structure is abbreviate | omitted, or attaches | subjects the same number and description is abbreviate | omitted.

  In 4th Embodiment, the structure of the guide rod 303 of 3rd Embodiment and the cable control apparatus 302 differs. As shown in FIG. 8, the guide rod 303 of the present embodiment includes a plurality of (e.g., three) members 303 a, 303 b, and 303 c having different widths and heights that are slidable with respect to each other. The overall length is variable so that it becomes thinner from the tip to the tip. The members 303a, 303b, and 303c are guided by the guide member 304 and the guided member 305 so as to be slidable with respect to each other, and the displacement is restricted in the longitudinal direction. These are not limited to sliding, but may be rolling by balls / rollers, fluid contact by gas / liquid, or non-contact by magnetism.

  FIG. 9 is a plan view of a part of the guide rod 303. As shown in FIG. 9, the cable 4 is inserted into the groove 310 of the guide rod 303b. A linear motor 306 is disposed on one side surface of the inner guide rod 303b, and a scale 307 serving as a track of the linear motor 306 is extended in the longitudinal direction on the inner surface of the guide rod 303c that faces the inner side. In addition, a linear encoder 308 is provided adjacent to the linear motor 306 of the guide rod 303b, and is configured to read the optical reading surface marked on the scale 307 and recognize the position.

  The guide rod 303 configured in this manner is synchronized with the movement control of the wafer stage WST by the main control system 41 and the cable control unit 57 by the linear motor 306, and the tip of the guide rod 303 together with the rotary table 206 serves as the wavefront aberration measurement unit 35. On the other hand, the guide rod 303 is expanded and contracted in the direction of the arrow in FIG.

  Therefore, in addition to the same effect as that of the third embodiment, the linear motor 306 directly drives the guide rod 303 having rigidity, so that there is an effect that the cable 4 can be guided with higher speed and accuracy.

  Although not shown, the guide rods 303a, 303b, and 303c may be connected to each other by sliding contacts instead of the cable 4, and an electrical signal may be transmitted by the guide rod 303 itself.

  (Fifth Embodiment) Next, an optical characteristic measuring apparatus 402 which is another embodiment of the optical characteristic measuring apparatus of the present invention will be described with reference to FIG. In addition, in order to avoid duplication of description, only a different part from other embodiment is demonstrated, the description of the same or equivalent structure is abbreviate | omitted, or attaches | subjects the same number and description is abbreviate | omitted.

  In the optical characteristic measuring device 402, the arm 404 having the rigidity of the cable control device 403 in accordance with the operation of the wafer stage WST operates on the main control system 41 and the cable control unit 57 (FIG. 1) as in the other embodiments. Is controlled to guide the cable 4 to the wavefront aberration measuring unit 35 at the target position. The present embodiment is characterized in that the arm 404 is configured as a robot arm having a first joint 405.

The arm 404 is configured to be refractable by a first joint 405, and its base is supported by a second joint 406 having a horizontal axis, and the second joint 406 has a vertical axis. The third joint 407 is fixed to the surface plate 23. That is, the arm 404 is configured as a robot arm having three joints. The cable 4 is inserted into the arm 404. Since the arm 404 is refracted, the length of the cable 4 itself does not change. Therefore, a winding mechanism is unnecessary, and there is an effect that the electrical structure can be made relatively simple. Further, since there is no electrical contact, there is an effect that it is possible to prevent the generation of noise due to the contact. Further, since the arm 404 is a robot arm having rigidity, there is an effect that high-speed operation is possible.
(Sixth Embodiment) FIG. 11 is a schematic plan view showing a cable control device 503 of an optical characteristic measuring device 502 of a sixth embodiment. The robot arm is composed of two joints: a first joint 505 that rotates an arm 504 about a vertical axis, and a second joint 506 that also rotates about a vertical axis. Other configurations are the same as those in the fifth embodiment.

  With this configuration, the displacement in the height direction cannot be performed in principle, but the displacement of the wafer stage WST in the Z direction is slight, so that it can be absorbed by the bending of the cable 4 having flexibility. Therefore, in addition to the effect of the optical characteristic measuring apparatus 402 of the fifth embodiment, the operating range in the height direction of the arm 504 can be minimized to achieve a compact design. Further, since the number of joints is small, there is an effect that the configuration can be further simplified.

Next, an embodiment of a device manufacturing method using the exposure apparatus 1 of the above embodiment in a lithography process will be described.
FIG. 12 is a flowchart illustrating a manufacturing example of a device (a semiconductor element such as an IC or LSI, a liquid crystal display element, an imaging element (CCD or the like), a thin film magnetic head, a micromachine, or the like). As shown in FIG. 12, first, in step S101 (design step), a function / performance design (for example, circuit design of a semiconductor device) of a device (microdevice) is performed, and a pattern design for realizing the function is performed. Do. Subsequently, in step S102 (mask manufacturing step), a mask (such as a reticle Rt) on which the designed circuit pattern is formed is manufactured. On the other hand, in step S103 (substrate manufacturing step), a substrate (or a wafer W when a silicon material is used) is manufactured using a material such as silicon or a glass plate.

  Next, in step S104 (substrate processing step), using the mask and substrate prepared in steps S101 to S103, an actual circuit or the like is formed on the substrate by lithography or the like, as will be described later. Next, in step S105 (device assembly step), device assembly is performed using the substrate processed in step S104. Step S105 includes processes such as a dicing process, a bonding process, and a packaging process (chip encapsulation or the like) as necessary.

  Finally, in step S106 (inspection step), inspections such as an operation confirmation test and a durability test of the device manufactured in step S105 are performed. After these steps, the device is completed and shipped.

  FIG. 13 is a diagram showing an example of a detailed flow of step S104 of FIG. 12 in the case of a semiconductor device. In FIG. 13, in step S111 (oxidation step), the surface of the wafer W is oxidized. In step S112 (CVD step), an insulating film is formed on the surface of the wafer W. In step S113 (electrode formation step), an electrode is formed on the wafer W by vapor deposition. In step S114 (ion implantation step), ions are implanted into the wafer W. Each of the above steps S111 to S114 constitutes a pretreatment process at each stage of the wafer processing, and is selected and executed according to a necessary process at each stage.

  At each stage of the wafer process, when the above pre-process is completed, the post-process is executed as follows. In this post-processing process, first, a photosensitive agent is applied to the wafer W in step S115 (resist formation step). Subsequently, in step S116 (exposure step), the circuit pattern of the mask (reticle Rt) is transferred onto the wafer W by the lithography system (exposure apparatus 31) described above. Next, in step S117 (developing step), the exposed wafer W is developed, and in step S118 (etching step), the exposed members other than the portion where the resist remains are removed by etching. In step S119 (resist removal step), the resist that has become unnecessary after the etching is removed.

Multiple circuit patterns are formed on the wafer W by repeatedly performing these pre-processing and post-processing steps.
If the device manufacturing method of this embodiment described above is used, the exposure apparatus 1 including the optical property measuring apparatus described in each of the above embodiments is used in the exposure step (step S116). Therefore, by measuring the optical characteristics with high accuracy, it is possible to further improve the resolving power by increasing the adjustment accuracy of the illumination optical system 17 and the projection optical system PL, and to perform exposure amount control with high accuracy. be able to. Therefore, as a result, a highly integrated device having a narrow minimum line width can be produced with a high yield.

In the above embodiment, the following changes can be made.
In the embodiment, the exposure apparatus is described as an example. However, the optical characteristic measuring apparatus of the present invention may be used for measuring the optical characteristics of the optical system, for example, other optical apparatuses such as a wafer inspection apparatus. Can be suitably applied.

  The cable control apparatus has been described as being disposed on the surface plate 23 outside the wafer stage WST, which is a moving stage. However, a part or all of the cable controlling apparatus may be disposed on the moving stage. . In the present embodiment, the optical characteristic measuring apparatus has been described as an example having a wavefront measuring function, but is not limited to this measuring function. For example, the function of measuring the polarization characteristics of exposure light, the function of measuring the shape of the pupil plane of the optical system, the function of measuring the light quantity distribution on the pupil plane of the optical system, and the numerical aperture (NA) of the optical system are measured. A function and a function of measuring an illuminance distribution on the image plane of the optical system may be provided. Furthermore, an optical characteristic measuring apparatus having these functions alone may be configured, or an optical characteristic measuring apparatus having a plurality of functions among these functions may be configured.

  The cable 4 may be configured so that a part of the cable 4 remains on the moving stage in addition to the cable 4 being completely separated from the moving stage. In this case, a configuration in which a part of the cable is arranged in the stage is also included. Moreover, the structure which provides a connector in a relay part and connects the cable 4 and a measurement unit to this relay part may be sufficient. Alternatively, the relay unit may have only a function of physically fixing the cable. The relay unit may be provided on the side surface of the moving stage in addition to the moving stage.

  The cable 4 is not limited to an electrical signal from a sensor, but includes a cable that exchanges fluid and light. Therefore, in addition to the covered wire, it may be composed of a tube-like one, an optical fiber or the like. Moreover, even if it does not have flexibility as a whole, a configuration in which a hard material and a soft material are combined, for example, a configuration such as a combination of a metal pipe and a bellows may be used. Furthermore, the structure which relays a part by radio | wireless, infrared rays, an ultrasonic wave, etc. may be sufficient.

The measurement unit of the present invention is not limited to the exemplified units, and includes units having various measurement functions other than those illustrated.
A linear motor has been described as an example for expanding and contracting a guide rod as an arm. However, a configuration in which a rotary motor is expanded and contracted by a gear mechanism such as a worm gear and a rack and pinion, or may be expanded and contracted by hydraulic pressure, air pressure, or the like.

  As described above, it goes without saying that a person skilled in the art can change or improve the invention without departing from the scope of the claims.

FIG. 3 is a block diagram illustrating a schematic configuration of the exposure apparatus 1. FIG. 6 is a schematic diagram showing measurement of wavefront aberration in the wavefront aberration measurement unit 35. The perspective view which shows typically the structure of the optical characteristic measuring apparatus 2 of 1st Embodiment. The perspective view which shows typically the structure of the optical characteristic measuring apparatus 102 of 2nd Embodiment. The perspective view which shows typically the structure of the optical characteristic measuring apparatus 202 of 3rd Embodiment. The figure which looked at the guide rod 204 in the optical characteristic measuring apparatus 202 of 3rd Embodiment from the front-end | tip part. Sectional drawing of the guide rod support part 205 vicinity in the optical characteristic measuring apparatus 202 of 3rd Embodiment. The figure which looked at the guide rod 203 in the optical characteristic measuring apparatus 302 of 4th Embodiment from the front-end | tip part. The fragmentary top view which shows the connection structure of the guide rod 203 in the optical characteristic measuring apparatus 302 of 4th Embodiment. The perspective view which shows typically the structure of the optical characteristic measuring apparatus 402 of 5th Embodiment. The top view which shows typically the structure of the optical characteristic measuring apparatus 502 of 6th Embodiment. The figure which shows the flowchart of the manufacture example of devices (semiconductor elements, such as IC and LSI, a liquid crystal display element, an image pick-up element (CCD etc.), a thin film magnetic head, a micromachine, etc.). The figure which shows an example of the detailed flow of step S104 of FIG. 12 in the case of a semiconductor device.

Explanation of symbols

  PL ... projection optical system, RST ... reticle stage, WST ... wafer stage, 1 ... exposure apparatus, 2, 102, 202, 302, 402, 502 ... optical characteristic measuring apparatus, 3, 103, 203, 403, 503 ... cable control Device, 4 ... cable, 404, 504 ... arm, 405 ... joint.

Claims (18)

In an optical property measuring apparatus for measuring optical properties of an optical system,
A measuring unit disposed on a moving stage and measuring the optical characteristics of the optical system;
An optical property measurement apparatus comprising: a cable control device that controls an operation of a cable connected to the measurement unit in accordance with an operation of the moving stage. 2. The optical characteristic measuring apparatus according to claim 1, wherein the optical system measured by the optical characteristic measuring apparatus is an optical system of an exposure apparatus, and the moving stage is a wafer stage or a reticle stage of the exposure apparatus. The optical characteristic measuring device according to claim 1, wherein the cable control device is fixed outside the moving stage. 4. The optical characteristic measuring apparatus includes at least one of a wavefront measuring function, a polarization measuring function, an illumination shape measuring function, a lens aperture shape measuring function, and an illumination illuminance measuring function. The optical property measuring apparatus according to any one of the above. The optical characteristic measuring apparatus according to claim 2, wherein the optical characteristic measuring apparatus is configured to be detachable from the exposure apparatus. 6. The optical characteristic measuring apparatus according to claim 1, wherein the cable control device controls the cable based on an instruction value for movement control of the moving stage. 7. The optical characteristic measurement device according to claim 1, wherein the cable control device controls the cable based on a measurement value obtained by measuring the movement of the moving stage. 8. The cable control device according to claim 1, further comprising: a cable length adjusting unit that adjusts a necessary length of the cable in accordance with an operation of the moving stage. 9. Optical property measuring device. 9. The optical characteristic measuring apparatus according to claim 8, wherein the cable length adjusting means adjusts the length by extending or drawing the cable in accordance with the operation of the moving stage. The cable control device performs automatic winding by applying tension to the cable, and reduces the tension when the moving stage moves away from the fixed point of the cable in accordance with the operation of the moving stage. 9. The optical characteristic measuring apparatus according to claim 8, further comprising cable tension adjusting means for controlling the operation of the cable by increasing the tension when approaching a fixed point of the cable. The said cable length adjustment means is provided with the swing mechanism which changes the drawing | feeding-out or drawing-in direction of the said cable according to the position of the said stage, The Claim 1 characterized by the above-mentioned. Optical property measuring device. The cable control device guides the cable to a target position by controlling an operation of an arm having rigidity in accordance with an operation of the moving stage. The optical property measuring apparatus according to 1. The optical characteristic measuring apparatus according to claim 12, wherein the arm includes a body that can be expanded and contracted, and the cable is built in the body. The optical characteristic measuring apparatus according to claim 12, wherein the arm is configured as a robot arm having a bendable joint. An optical property measuring method, comprising: measuring an optical property of an optical system using the optical property measuring apparatus according to claim 1. In an exposure apparatus that exposes a pattern image formed on a mask on a reticle stage onto a substrate on a wafer stage via a projection optical system,
An exposure apparatus comprising the optical property measuring apparatus according to claim 1. An exposure method using the exposure apparatus according to claim 16, wherein exposure is performed based on optical characteristics of an optical system measured by the optical characteristic measurement apparatus. A device manufacturing method including a lithography process, wherein exposure is performed using the exposure apparatus according to claim 16 in the lithography process.

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