JP3958321B2 - Exposure apparatus and device manufacturing method - Google Patents

Description

  The present invention relates to an exposure apparatus used for manufacturing a semiconductor device or the like by exposing a design pattern to a resist on a substrate, and a device manufacturing method using the exposure apparatus.

  Conventionally, as such an exposure apparatus, a stepper that sequentially moves a substrate such as a wafer or the like to a plurality of exposure regions on the substrate through a projection optical system while moving the substrate stepwise, and a relative to the projection optical system. 2. Description of the Related Art A scanning exposure apparatus that scans and exposes a mask pattern onto a substrate by moving the mask and the substrate and scanning the mask and the substrate with slit-shaped exposure light is known.

  Further, in recent years, by repeating the step movement and scanning exposure so that a fine pattern can be exposed with higher accuracy, a plurality of regions on the substrate are exposed with a fine pattern with high accuracy. An AND-scan type exposure apparatus has been proposed. Since this exposure apparatus uses only a portion of the projection optical system that is relatively close to the optical axis, which is limited by the slit, exposure of a fine pattern with higher accuracy is possible. In scanning exposure, the stage position is monitored using a laser interferometer in order to move the reticle stage and wafer stage while precisely controlling the scanning direction and the like. Further, in order to position the wafer at the focus position of the projection optical system, the measurement light is projected onto the wafer by the light projecting means, the measurement light reflected by the wafer is received by the light receiving means, and the position of the wafer surface is determined. I try to detect it. Further, the measurement optical path by the laser interferometer and the optical path of the measurement light for detecting the wafer surface position are air-conditioned by the air-conditioning means so as to increase the measurement accuracy.

  However, in such a scanning type exposure apparatus, in order to effectively expose a fine pattern with higher accuracy, the measurement accuracy of the position of the reticle stage or the wafer stage or the detection of the position of the wafer surface is detected. There is a problem that the accuracy is insufficient. In addition, it is necessary to perform scanning exposure after the vibration that occurs due to acceleration / deceleration when moving the reticle stage in the scanning direction, but it takes a considerable amount of time to converge this vibration, which increases productivity. There is also a problem of decreasing.

  The object of the present invention is to improve the measurement accuracy of the position of the original stage and the substrate stage, and further the measurement accuracy of the position of the substrate surface in the exposure apparatus and the device manufacturing method that can use the exposure apparatus, in view of the problems of the prior art. There is to make it.

The exposure apparatus of the object of the present invention to achieve a master stage for moving the original, a substrate stage which moves the substrate, and a projection optical system for projecting a pattern of the original onto the substrate, the position of the original stage and original-side laser interferometer for measuring, and a substrate-side laser interferometer for measuring the position of the substrate stage, and the original stage by feeding back the measured position of said original stage and said substrate stage in scanning exposure apparatus for exposing a pattern of the original while moving the substrate stage in the scanning direction projected to on the substrate,
And the original air-conditioning means for conditioning the measurement optical path by the original-side laser interferometer, and the substrate-side air conditioning means for conditioning the measurement optical path by the substrate-side laser interferometer, a separately provided, even when the exposure stand, at least the wherein the continuously moving one of the original stage and said substrate stage.

Here, the exposure apparatus of the present invention includes a lens barrel base plate provided with the projection optical system and the original stage, and a base that has a plurality of columns and supports the lens barrel plate via a damper on each column. Preferably , the substrate-side air conditioning means includes a passage for returning air when the apparatus is placed in the chamber for air conditioning at the lower part of the base frame .

Alternatively, the exposure apparatus of the present invention includes a projection optical system that projects an original pattern onto a substrate, and a focus detection unit that positions the substrate at a focus position of the projection optical system. In an exposure apparatus comprising a light projecting means for projecting measurement light onto a substrate disposed at an exposure position, and a light receiving means for receiving measurement light projected thereby and reflected by the substrate,
An air conditioning means for air-conditioning the optical path of the measurement light is provided, and the emission surface or the incident surface of the measurement light in the light projection means or the light reception means is a cylindrical surface or a spherical surface.

In this case, for example, the light projecting means or the light receiving means has an exit glass surface that emits the measurement light or an incident glass surface on which the measurement light is incident, and the exit glass surface or the incident glass surface and the air blowing direction of the air conditioning means Are substantially parallel. Alternatively, the optical path of the measurement light and the air blowing direction of the air conditioning means are substantially orthogonal to each other. Also, as viewed in the air blowing direction of the air conditioning unit, before and after the light projecting means or light receiving means includes a member adjacent thereto, an exit surface or the incident surface of the light-emitting means or the light receiving means, said member to be connected thereto The surface shape is constituted by a curved surface.

  In this case, the exposure apparatus further includes an original stage for moving the original and a substrate stage for moving the substrate, and projects the pattern of the original onto the substrate while moving the original stage and the substrate stage in the scanning direction. And a lens barrel surface plate provided with a projection optical system and an original stage, and three column columns that support the lens column plate plate via a damper on each column column. And a base frame, wherein the air blowing direction of the air-conditioning means is a direction substantially perpendicular to a line connecting any two struts.

A plate-like member for guiding the flow of air blown from the air conditioning means to the optical path of the measurement light below the projection optical system may be provided between the air outlet of the air conditioning means and the projection optical system.

Alternatively, the device manufacturing method of the present invention, the position of the original is measured by original-side laser interferometer, the position of the substrate measured by the substrate side laser interferometer, the original plate is fed back to the measurement position of the original and the substrate wherein upon manufacturing a device by scanning exposure by projecting onto the substrate through a pattern the projection optical system of the original while moving the substrate in the scanning direction, the measuring optical path and by the original-side laser interferometer and the separately conditioning the measurement optical path by the substrate-side laser interferometer, even at the time of exposure stand, characterized in that continue to move one of the substrate stage for moving the original stage and said substrate moving at least the original.

In this case, for example, the original stage for moving the original and the projection optical system are provided on the lens barrel surface plate, and this lens barrel surface plate is supported via a plurality of support columns provided on the base frame and dampers on the respective support columns. The substrate-side air conditioning when the apparatus is placed in the chamber for air conditioning is performed through a return passage provided in the lower part of the base frame .

Alternatively, the device manufacturing method of the present invention, the light projecting means the measurement light on a substrate disposed at an exposure position and projecting light, the measurement light reflected by the substrate and received by the light receiving means, the projection optical system thereby positioning the substrate to the focus position, when manufacturing a device by exposing by projecting onto the substrate through a pattern the projection optical system of the original, as well as air-conditioning by the air conditioning unit the optical path of the measuring light, wherein the exit surface or the incident surface of the measuring light in the light projecting means or said light receiving means is a cylindrical surface or a spherical surface.

In this case, for example, the light projecting means or the light receiving means has an exit glass surface that emits measurement light or an incident glass surface on which measurement light is incident, and the exit glass surface or the incident glass surface and the air blowing direction of the air conditioning means It is characterized by being almost parallel. Furthermore, the optical path of the measurement light and the air blowing direction of the air conditioning means are substantially orthogonal to each other. Furthermore, when viewed in the air blowing direction of the air-conditioning means, a member adjacent to the light-projecting means or the light-receiving means is provided before and after the light-projecting means or the light-receiving means. To form the cylindrical surface or the spherical surface .

  In this case, preferably, the original is moved by the original stage, the substrate is moved by the substrate stage, the original pattern is projected onto the substrate while moving the original stage and the substrate stage in the scanning direction, and scanning exposure is performed. The optical system and the original stage are provided on the lens barrel base plate, and the lens barrel base plate is supported via three pillars on the base frame and a damper on each pillar, and the air blowing direction of the air-conditioning means is either The direction is almost perpendicular to the line connecting the two columns.

A plate-like member provided between the air outlet of the air conditioning unit and the projection optical system may guide the flow of air blown from the air conditioning unit to the optical path of the measurement light below the projection optical system.

According to the present invention, since so as to separate the air conditioning the measurement optical path by the measurement optical path Contact and substrate side laser interferometer according to the original-side laser interferometer, these measurement optical path are separated from each other uniformly conditioning respectively, the entire device As a result, the uniformity of temperature can be guaranteed. In addition, even during exposure standby, since the original stage or the substrate stage that moves the substrate is kept moving, the air in the moving space of each stage is constantly stirred, and the temperature difference between these spaces and the surrounding environment is kept constant. be able to. Further, the amount of heat generated by the moving means of each stage can be kept constant during exposure and during exposure standby. Therefore, it is possible to improve the temperature stability around each stage and perform exposure with high accuracy.

  Further, since air conditioning on the substrate side is performed through a return passage provided in the lower portion of the base frame, space saving and air conditioning can be made uniform.

Further, since the measuring light emitting surface or incident surface of the focus detecting means or the incident surface or the surface composed of the surface and the surface connected thereto is a cylindrical surface or a spherical surface , the focus detection accuracy is improved. Can do.

Further , the light projecting means or the light receiving means has an exit glass surface that emits the measurement light or an incident glass surface on which the measurement light is incident, and the exit glass surface or the incident glass surface is substantially parallel to the air blowing direction of the air conditioning means. In other words, since the airflow in front of the exit glass surface or the entrance glass surface is not disturbed, focus detection accuracy can be improved.

Alternatively , in the air blowing direction of the air-conditioning means, a member adjacent to the light-projecting means or the light-receiving means is provided before and after the light-projecting means or the light-receiving means. Thus, since the cylindrical surface or the spherical surface is configured, the air flow in front of the exit glass surface or the entrance glass surface is not disturbed, so that the focus detection accuracy can be improved.

  Moreover, the lens barrel surface plate is supported via three pillars on the base frame and a damper on each pillar, and the air blowing direction of the air-conditioning means is a direction substantially perpendicular to the line connecting any two pillars Thus, the arrangement of the exposure apparatus, the air conditioning unit, and the focus detection unit can be made appropriate. For example, as shown in FIG. 7, both the focus detection system and the measurement optical path of the laser interferometer in the XY directions can be air-conditioned by one air-conditioning means, and the space on the exposure apparatus can be used effectively.

  Further, a plate-like member provided between the air outlet of the air conditioning unit and the projection optical system guides the flow of air blown from the air conditioning unit onto the optical path of the measurement light of the focus detection unit below the projection optical system. Therefore, the flow velocity of air passing through the optical path can be increased, and the temperature stability on the optical path can be further improved.

  Therefore, the original pattern can be scanned and exposed on the substrate with high accuracy, and a device having a highly accurate circuit pattern or the like can be manufactured with high efficiency.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a view schematically showing an exposure apparatus according to the first embodiment of the present invention as viewed from the side, and FIG. 2 is a perspective view showing the appearance of the exposure apparatus. As shown in these drawings, this exposure apparatus projects a part of the reticle pattern onto the wafer on the fine movement stage 80 provided on the XY stage apparatus 3 via the projection optical system 2, and the projection optical system 2. In contrast, the reticle pattern is exposed to the wafer by synchronously scanning the reticle and the wafer in the Y direction, and the scanning exposure is performed while interposing a step movement for repeatedly performing a plurality of regions on the wafer. This is a step-and-scan type exposure apparatus to be performed.

  The movement of the reticle in the scanning direction (Y direction) is performed by the reticle side stage device, and this stage device moves the movable element 4b in the scanning direction by applying a thrust between the stationary element 4a and the movable element 4b. A linear motor 4 to be moved is provided, and the reticle stage 1 is coupled to the movable element 4b. The stator 4a is supported by the first support means 101 with a degree of freedom in the Y direction. Then, the second support means 105 is supported rigidly in the Y direction and softly in the other directions. The second support means 105 includes a column portion 103 extending upward from the base frame 10, and a uniaxial support that extends in the Y direction from the column portion 103 and supports the stator 4a rigidly in the Y direction and flexibly in the other directions. Means 102 are included.

  The reticle stage 1 is driven in the Y direction by the linear motor 4, the X stage 3 a of the XY stage device 3 is driven in the X direction by the linear motor 5, and the Y stage 3 b is driven in the Y direction by the linear motor 6. Yes. The synchronous scanning of the reticle and the wafer is performed by driving the reticle stage 1 and the Y stage 3b in the Y direction at a constant speed ratio (for example, 4: 1). Further, the step movement in the X direction is performed by the X stage 3a.

  The XY stage apparatus 3 is provided on a stage surface plate 7, and the stage surface plate 7 is supported on a floor or the like at three points via three dampers 8. The first support means 101 and the projection optical system 2 are provided on a lens barrel base plate 9, and the lens barrel base plate 9 is supported on a base frame 10 via three dampers 11 and support columns 12. The damper 8 is an active damper that actively dampens or dampens vibrations in the six-axis direction. However, a passive damper may be used, or the damper 8 may be supported without a damper.

  In this configuration, when the wafer is loaded onto the XY stage apparatus 3 via the transfer path between the two support columns 12 at the front of the apparatus by the transfer means (not shown), and the predetermined alignment is completed, the exposure apparatus performs scanning exposure. While repeating the step movement, the reticle pattern is exposed and transferred to a plurality of exposure areas on the wafer. In scanning exposure, the reticle stage 1 and the Y stage 3b are moved in the Y direction (scanning direction) at a predetermined speed ratio, and the pattern on the reticle is scanned with slit-shaped exposure light, and the projected image is used for the wafer. , The pattern on the reticle is exposed to a predetermined exposure area on the wafer. When the scanning exposure for one exposure region is completed, the X stage 3a is driven in the X direction to move the wafer stepwise, thereby positioning the other exposure region with respect to the scanning exposure start position and performing the scanning exposure. Note that the combination of the step movement in the X direction and the movement for scanning exposure in the Y direction allows each exposure area to be sequentially and efficiently exposed to a plurality of exposure areas on the wafer. The arrangement, the scanning direction to positive or negative of Y, the exposure order to each exposure area, and the like are set.

  FIG. 3 schematically shows a configuration for measuring these stage positions in order to control the driving of the reticle stage 1, the X stage 3 a, the Y stage 3 b, and the fine movement stage device 80.

  As shown in the figure, this configuration includes reticle-side laser interferometers 31, 32, and 33 and wafer-side laser interferometers 34, 35, and 36 for measuring the positions of the reticle stage 1 and fine movement stage 80, respectively. Is provided. Both the laser-side laser interferometers 31 and 32 and the wafer-side laser interferometer 36 use laser light from the same laser head 37. The reticle side laser interferometer 33 and the wafer side laser interferometers 34 and 35 both use laser light from the same laser head 38. The reticle-side laser interferometers 31 and 32 are used to measure the Y-axis direction (scanning direction) position of the reticle stage 1 and the θ-position around the Z-axis, and the reticle-side laser interferometer 33 is used to measure the X-axis of the reticle stage 1. Used for measuring the directional position. The wafer side laser interferometer 36 is used to measure the position of the fine movement stage 80 in the Y-axis direction, and the wafer side laser interferometers 34 and 35 measure the position of the fine movement stage 80 in the X-axis direction and the θ position around the Z axis. Used for. Although not shown, a mirror is fixed on each of the stages 1 and 80 so as to reflect light from each laser interferometer in the length measuring direction so that measurement can be performed in each laser interferometer. ing. These laser interferometers 31 to 36 are all fixed to the lens barrel surface plate 9.

  Laser light emitted from the laser head 37 in the Y direction is reflected in the X direction by the reflection mirror 39 and further separated into the X direction and the Z direction by the beam splitter 40. The separated laser beam in the X direction is reflected in the Y direction by the reflection mirror 41 and guided to the laser interferometer 36. The separated laser beam in the Z direction is reflected in the X direction by the reflection mirror 42 and further separated in the X direction and the Y direction by the beam splitter 43. The separated laser beam in the X direction is reflected in the Y direction by the reflection mirror 44 and guided to the laser interferometer 31. The separated laser beam in the Y direction enters the laser interferometer 32 as it is and is used by the laser interferometer 32. Similarly, the laser light from the laser head 38 is separated and guided by the beam splitters 45 and 46 and the reflection mirrors 47 and 48 and used by the laser interferometers 34, 35 and 33.

  At the time of scanning exposure, the measurement value of the position in the Y direction of the reticle stage 1 by the laser interferometer 31 or 32 is fed back, and the drive of the linear motor 4 is controlled to move the reticle stage 1 in the Y direction. Further, the Y stage 3b is moved in the Y direction by feeding back the measurement value of the Y direction position of the fine movement stage 80 by the laser interferometer 36 and controlling the drive of the linear motor 6. At this time, the movement of the reticle stage 1 and the Y stage 3b needs to be performed in synchronization so that a constant speed ratio (for example, 4: 1) is obtained, as described above. In this respect, since the laser interferometer 31 or 32 and the laser interferometer 36 use laser light from the same laser head 37, measurement errors due to fluctuations in the laser light cause laser errors on both the reticle side and the wafer side. The same occurs in the interferometer. Therefore, there is no synchronization shift caused by fluctuations in laser light.

  In this scanning exposure, the reticle stage 1 and fine movement stage 80 must always maintain a fixed positional relationship in the θ direction and the X direction. Regarding the θ direction, the θ of the reticle stage 1 is measured based on the measured value of the θ direction position of the reticle stage 1 by the laser interferometers 31 and 32 and the measured value of the θ direction position of the fine movement stage 80 by the laser interferometers 34 and 35. By adjusting the θ-direction position of fine movement stage 80 so as to follow the change in the direction position, a predetermined positional relationship between both stages is maintained. Further, with respect to the X direction, based on the measured value of the X direction position of the reticle stage 1 by the laser interferometer 33 and the measured value of the X direction position of the fine movement stage 80 by the laser interferometer 34 or 35, By adjusting the X direction position of the X stage 3a so as to follow the variation in the X direction position, a predetermined positional relationship between both stages is maintained. Even in these cases, since the light from the same laser head is used for reticle-side and wafer-side laser interference, the positional relationship between both stages can be accurately maintained regardless of fluctuations in the laser beam. Can do.

  4 and 5 are a front view and a perspective view showing the base frame 10, respectively. As shown in these drawings, the base frame 10 includes a coupling member 51 that couples the columns 12 at their upper portions. The connecting member 51 is not shown in FIGS. The coupling member 51 is located above the damper on each pillar 12 (damper 11 in FIG. 2) and adjacent to the damper, and when viewed from above, each coupling member 12 and the damper thereon are connected to them. A member 53 that joins between the member 52 and the upper end of each column 12 via the outside of the damper on each column 12 and a substantially triangular member 52 having a size and shape so as to substantially touch and surround them. Have Although not shown in FIGS. 4 and 5, the bottom of the lens barrel surface plate 9 is fitted on the triangular member 52 and disposed on each damper 11. In addition, the base frame 10 is supported at a distance of about 10 cm from the floor 55, and a space 54 for returning air when the apparatus is placed in the chamber for air conditioning is secured between the base frame 10 and the floor 55 below the base frame 10. is doing.

  Thus, by connecting the support columns 12 with the connecting members 51, the rigidity of the base frame 10 can be increased, and the lens barrel surface plate 9 can be prevented from greatly vibrating when the reticle stage 1 is accelerated or decelerated. Therefore, it is possible to shorten the time until the vibration of the lens barrel surface plate 9 due to acceleration of the reticle stage 1 is converged, and to perform scanning exposure promptly after acceleration. Further, since the return space 54 is provided at the lower part of the base frame 10, the space in the chamber can be used effectively, and the air conditioning in the chamber can be made uniform and highly clean. . Moreover, the measurement accuracy of a laser interferometer or the like can be improved by making the air conditioning uniform.

  FIG. 6 is a schematic view of the essential portions of a projection exposure apparatus according to the second embodiment of the present invention. In the figure, reference numeral 66 denotes an exposure illumination system that illuminates a reticle (photomask) 67. A circuit pattern 68 formed by chromium vapor deposition or the like is provided on the lower surface of the reticle 67. Reference numeral 69 denotes a reticle stage (reticle holder) that holds the reticle 67 and is movable in the XYθ directions. The reticle holder 4 sucks and holds the reticle 67 and moves two-dimensionally in a second orthogonal coordinate system xy in a plane parallel to the XY plane of the first orthogonal coordinate system. The origin of the second orthogonal coordinate system xy is the optical axis of the projection lens 70.

  The projection lens (projection optical system) 70 projects the circuit pattern 68 of the reticle 67 illuminated by the exposure illumination system 66 onto the wafer 71. A wafer holder 72 holds the wafer 71 by suction. Reference numeral 73 denotes a θZ tilt stage, which drives the wafer holder 72 slightly around the Z axis (θ drive), slightly drives it in the Z direction (Z drive), and drives it slightly around the X and Y axes (tilt drive). . Reference numeral 74 denotes an XY stage, which two-dimensionally drives the θZ tilt stage 73 in the first orthogonal coordinate system XY direction.

  An interferometer mirror 75 is fixed to the XY stage 74 and is used for monitoring the position in the X direction by an interferometer (laser interferometer) 76. The interferometer mirror 75 and the interferometer 76 are similarly arranged in the Y direction. The laser beams from the two interferometers 76 are set to coincide on the optical axis of the projection lens 70. Using the signals obtained from the interferometer mirror 75 and the interferometer 76, the XY stage control system 77 positions the wafer 71 at a predetermined position. That is, the position of the XY stage 74 with respect to the optical axis of the projection lens 70 that is the origin of the first orthogonal coordinate system XY set in advance in the apparatus while the XY stage 74 is moving or stationary is sequentially measured. The XY stage 74 is positioned at a predetermined position by the control system 77.

  An optical focus detection system 61 includes a light projecting unit 64 and a detection unit 65, and detects the surface position of the wafer 71 in the optical axis direction. The light projecting means 64 irradiates the wafer 71 from the oblique direction with a light beam 78 that does not expose the photoresist applied to the wafer 71. Since the light beam 78 is reflected by the wafer 71 and enters the detection means 65, the incident position changes according to the surface position of the wafer 71 in the optical axis direction. The detection means 65 measures the distance in the optical axis direction between the projection lens 70 and the wafer 71 without passing through the projection lens 70 by measuring the incident position of the light beam 78.

  That is, the optical focus detection system 61 detects the height of the surface of the wafer 71 with respect to the projection lens 70, and the detected value becomes a predetermined best focus value Za (a predetermined command value indicating the height of the image plane of the projection lens 70). Thus, the θZ tilt stage 73 drives the wafer 71 in the Z direction. Thereby, a projection image of the circuit pattern 68 of the reticle 67 is formed on the surface of the wafer 71. In other words, focusing is performed so that a projected image with high contrast can always be transferred. The predetermined best focus value Za is set by, for example, exposing a predetermined test pattern while focusing and developing the circuit pattern 68 prior to the exposure of the circuit pattern 68, and evaluating the resolution.

  For convenience of the following description, the light beam 78 of the optical focus detection system 61 is shown as one, but actually, it has a plurality of light beams, for example, five light beams, and the tilt of the wafer 71 is also measured. Then, the θZ tilt stage 73 tilts the wafer 71 so that the best focus is obtained at any image height of the projected image.

  FIG. 7 is a schematic plan view of the main part when viewed in the AA cross section of FIG. As shown in the figure, the light projecting means 64, the light beam 78, and the detecting means 65 are arranged in a direction rotated 45 degrees clockwise with respect to the X axis of the first orthogonal coordinate system XY. In FIG. 7, reference numeral 79 denotes a temperature control air blowing filter, which uniformly blows temperature control air 80 supplied from a temperature control unit (not shown) toward the wafer 71. The temperature control air 80 is controlled so that the temperature of the air is 80% or less over the entire opening of the temperature control air blowing filter 79.

  The feature of this embodiment is that the blowing direction of the temperature control air 80 is substantially orthogonal to the direction of the light beam 78 of the optical focus detection system 61. As a result, the temperature control air 80 flows uniformly from the upstream to the downstream between the light projecting means 64 and the detection means 65, and hardly creates a vortex that entrains the air whose temperature has changed stagnation on the downstream side.

  This will be described with reference to FIG. 8 in which the space between the light projecting means 64 and the detecting means 65 is enlarged. In this figure, reference numeral 81 denotes an exit glass surface from which the light beam 78 is emitted from the light projecting means 64, and is orthogonal to the light beam 78. Reference numeral 82 denotes an incident glass surface on which the light beam 78 enters the detection means 65, and is orthogonal to the light beam 78. For this reason, both the outgoing glass surface 81 and the incoming glass surface 82 are substantially parallel to the blowing direction of the temperature control air 80. Therefore, the temperature-controlled air 80 goes straight not only at the intermediate portion between the light projecting means 64 and the detecting means 65 but also at the boundary surfaces of the outgoing glass surface 81 and the incoming glass surface 82. Note that a vortex 83 is generated on the downstream side of each of the light projecting means 64 and the detecting means 65 and becomes a vortex that entrains the air whose temperature has changed due to the stagnation on the downstream side, but before the exit glass surface 81 and the entrance glass surface 82. It does not become a vortex. Further, the temperature control air 80 collides with the light projecting means 64 and the detection means 65 on the upstream side, and the flow disturbance 84 is generated. However, the temperature change is extremely small because it does not stagnate. Therefore, even if the air from the turbulent flow 84 is mixed with the temperature control air 80 flowing to the boundary surfaces of the exit glass surface 81 and the entrance glass surface 82, the temperature change is extremely small.

  From the above, the temperature of the air through which the light beam 78 passes is almost the same as the temperature of the air blown from the temperature-controlled air blowing filter 79 throughout the space between the light projecting means 64 and the detecting means 65. For this reason, the amount of fluctuation of the position of the light beam 78 incident on the detecting means 65 due to the so-called “fluctuation” generated by the short-term periodic fluctuation of the temperature of the air is only due to the influence of the control accuracy of the temperature control air 80. It is almost limited to a very small size.

  In the present embodiment, the blowing direction of the temperature control air 80 is substantially orthogonal to the direction of the light beam 78 of the optical focus detection system 61. However, qualitatively, it is more desirable that the direction is orthogonal as much as possible, The desired effect can be obtained even in a substantially orthogonal crossing at an angle of up to about 45 degrees.

  In this embodiment, the light focus detection system 61, that is, the light projecting means 64, the light beam 78, and the detection means 65 are arranged in a direction rotated 45 degrees clockwise with respect to the first orthogonal coordinate system XY axis. It is not necessarily limited to that direction, and the point is that any direction may be used as long as the direction and the blowing direction of the temperature control air 80 are substantially orthogonal to each other. However, when arranged in the direction of the present embodiment, the laser light from the two interferometers 76 is also temperature-controlled by the temperature-controlled air 80 to stabilize the measured value, so that the temperature-controlled air blowing filter 79 is detected by the optical focus. There is no need to provide the system 61 and the interferometer 76 individually.

From the above, the focus detection accuracy of the optical focus detection system 61 is improved.
In addition, the thing of 1st Embodiment is employable as another structure which is not mentioned here.

  FIG. 9 is a schematic diagram of a main part of a projection exposure apparatus according to the third embodiment of the present invention. This figure corresponds to the figure when FIG. 6 is viewed from the side, and only the baffle 91 is added to that of FIG. The baffle plate 91 is a plate provided so as to connect the upper part of the temperature control air blowing filter 79 and the lower part of the projection lens 70 so that the temperature control air 80 flows more smoothly to the lower part of the projection lens 70. For this reason, the flow velocity of the air passing through the light beam 78 of the optical focus detection system 61 is increased, the temperature stability of the air is further increased, and the focus detection accuracy of the optical focus detection system 78 is further improved. In FIG. 9, 92 is an air conditioner connected to the filter 79, and 93 is its return duct.

  FIG. 10 is a schematic diagram of a main part of a projection exposure apparatus according to the fourth embodiment of the present invention. The feature of this embodiment is that the light beam 78 emitted from the light projecting means 64 and the outgoing glass surface 81 are not perpendicular to each other but are oblique, and the light beam 78 entering the detection means 65 and the incident glass surface 82 are also perpendicular. The outgoing glass surface 81 and the incoming glass surface 82 are both substantially parallel to the blowing direction of the temperature-controlled air 80. For this reason, each boundary between the exit glass surface 81 and the incident glass surface 82 as well as the intermediate portion between the light projecting means 64 and the detection means 65, even though the blowing direction of the light beam 78 and the temperature control air 80 is not orthogonal. Also on the surface, the temperature control air 80 goes straight. That is, in the case where the light emission direction of the light beam 78 and the temperature control air 80 is crossed obliquely, the desired effect can be obtained by making the exit glass surface 81 and the incident glass surface 82 substantially parallel to the direction of the temperature control air 80. Becomes larger.

  FIG. 11 is an enlarged view showing a space between the light projecting means 64 and the detecting means 65 in the projection exposure apparatus according to the fifth embodiment of the present invention. The feature of this embodiment is that the exit glass surface 81 of the light projecting means 64 and the entrance glass surface 82 of the detection means 65 are not flat but cylindrical (or spherical), that is, each is a cylindrical lens (or convex lens). ) 86 and 85 convex surfaces. The light projection means 64 illuminates the mask 88 by the light source 90 and the mask illumination system 89, and the mark 94 provided on the mask 88 is imaged on the wafer 95 by the mark projection optical system 87 and the cylindrical lens (or convex lens) 86. The detection means 65 can be realized by forming the image 92 reflected by the wafer on the light receiving element 83 by the cylindrical lens (or convex lens) 85 and the mark light receiving optical system 84. As described above, when the exit glass surface 81 and the entrance glass surface 82 are cylindrical (or spherical), the exit glass surface 81 and the entrance are incident even if the light beam 78 and the temperature-controlling air 80 are blown out obliquely. The temperature control air 80 flows smoothly at each boundary surface of the glass surface 82 without separation. That is, even when the light beam 78 and the temperature-controlling air 80 are blown in an oblique direction, the desired effect is great, and the range that can be made oblique is widened.

  FIG. 12 shows an optical focus detection system in a projection exposure apparatus according to the sixth embodiment of the present invention. As shown in the figure, in this apparatus, the exit glass surface 81 and the entrance glass surface 82 are flat as in the second embodiment, but a curved surface member 96 is provided on the front and back thereof to provide the same effect as in the fifth embodiment. Like to get.

  FIG. 13 is a schematic diagram showing the air conditioning in the projection exposure apparatus according to the seventh embodiment of the present invention. As shown in the figure, air conditioning is performed by using a separate air conditioner 92 and a separate air conditioner 92 on the measurement optical paths of the laser interferometers 31, 32, 33 on the reticle side and the laser interferometers 34, 35, 36 (FIG. 3) on the wafer side. 94. The return passage 93 of the air conditioner 62 is provided under the base frame 10 as shown in FIG. Reference numerals 79 and 95 denote temperature control air outlets of the air conditioners 92 and 94, respectively. Note that the configuration of the first embodiment can be adopted as a configuration not mentioned here or a configuration not shown in FIG. 13.

  Since the measurement optical path of the reticle-side laser interferometer and the measurement optical path of the wafer-side laser interferometer are considerably separated via the lens barrel surface plate 9 as shown in FIGS. 1 and 2, one air conditioner or Although it is difficult to air-condition each measurement optical path uniformly by the blowout port, the measurement optical paths on the reticle side and the wafer side are separated by air-conditioning the measurement optical path on the reticle side and the wafer side separately as in this embodiment. Air conditioning can be performed more uniformly.

  Further, the exposure apparatus continues to move the reticle stage 69 and the XY stage 74 even during exposure standby. As a result, the air on the measurement optical paths on the reticle side and wafer side is agitated, and the temperature difference from the surroundings is kept constant. Further, the amount of heat generated by the linear motor that moves the reticle stage 69 and the XY stage 74 is kept constant. Therefore, temperature stability on each measurement optical path is improved, and highly accurate measurement is possible.

  Next, device manufacturing examples that can utilize the exposure apparatuses of the above embodiments will be described. FIG. 14 shows a flow of manufacturing a microdevice (a semiconductor chip such as an IC or LSI, a liquid crystal panel, a CCD, a thin film magnetic head, a micromachine, etc.). In step 31 (circuit design), a semiconductor device circuit is designed. In step 32 (mask production), a mask on which the designed circuit pattern is formed is produced. On the other hand, in step 33 (wafer manufacture), a wafer is manufactured using a material such as silicon. Step 34 (wafer process) is called a pre-process, and an actual circuit is formed on the wafer by lithography using the prepared mask and wafer. The next step 35 (assembly) is referred to as a post-process, and is a process of forming a semiconductor chip using the wafer produced in step 34, and is a process such as an assembly process (dicing, bonding), a packaging process (chip encapsulation), or the like. including. In step 36 (inspection), inspections such as an operation confirmation test and a durability test of the semiconductor device manufactured in step 35 are performed. Through these steps, the semiconductor device is completed and shipped (step 37).

  FIG. 15 shows a detailed flow of the wafer process. In step 41 (oxidation), the wafer surface is oxidized. In step 42 (CVD), an insulating film is formed on the wafer surface. In step 43 (electrode formation), an electrode is formed on the wafer by vapor deposition. In step 44 (ion implantation), ions are implanted into the wafer. In step 45 (resist process), a photosensitive agent is applied to the wafer. In step 46 (exposure), the circuit pattern of the mask is printed on the wafer by exposure using the exposure apparatus described above. In step 47 (development), the exposed wafer is developed. In step 48 (etching), portions other than the developed resist image are removed. In step 49 (resist stripping), the resist that has become unnecessary after etching is removed. By repeatedly performing these steps, multiple circuit patterns are formed on the wafer.

  If this manufacturing method is used, a highly integrated semiconductor device that has been difficult to manufacture can be manufactured at low cost.

It is a figure which shows typically a mode that the exposure apparatus which concerns on the 1st Embodiment of this invention was seen from the side. It is a perspective view which shows the external appearance of the exposure apparatus of FIG. It is a figure which shows typically the structure for measuring these stage positions in order to control the drive of each stage of FIG. It is a front view which shows the base frame of the apparatus of FIG. It is a perspective view which shows the base frame of the apparatus of FIG. It is a principal part schematic of the projection exposure apparatus which concerns on the 2nd Embodiment of this invention. It is a top view which shows the principal part outline when it sees in the AA cross section of FIG. It is a figure which expands and shows between the light projection means and detection means of FIG. It is a principal part schematic diagram of the projection exposure apparatus which concerns on the 3rd Embodiment of this invention. It is a principal part schematic of the projection exposure apparatus which concerns on the 4th Embodiment of this invention. It is a figure which expands and shows between the light projection means and the detection means in the projection exposure apparatus which concerns on the 5th Embodiment of this invention. It is a figure which shows the optical focus detection system in the projection exposure apparatus which concerns on the 6th Embodiment of this invention. It is a schematic diagram which shows the mode of the air conditioning in the projection exposure apparatus which concerns on the 7th Embodiment of this invention. It is a flowchart which shows the flow of manufacture of the microdevice which can be manufactured with the apparatus of FIGS. It is a flowchart which shows the detailed flow of the wafer process in FIG.

Explanation of symbols

  1: reticle stage, 2: projection optical system, 3: XY stage, 4: linear motor, 4a: stator, 4b: mover, 3a: X stage, 3b: Y stage, 6: linear motor, 7: stage fixed Panel: 8: Damper, 9: Lens barrel, 10: Base frame, 11: Damper, 12: Support, 13: Distance measuring means, 31-36: Laser interferometer, 37, 38: Laser head, 39, 41 , 42, 44, 47, 48: reflection mirror, 40, 43, 45, 46: beam splitter, 54: space for air return, 61: light focus detection system, 64: light projecting means, 65: detection means, 66: Exposure illumination system, 67: reticle, 68: circuit pattern, 69: reticle stage, 70: projection lens, 71: wafer, 72: wafer holder, 73: θZ tilt stage, 74: XY 75: Interferometer mirror, 76: Interferometer, 77: XY stage control system, 78: Light flux, 79: Blow filter, 80: Air, 80: Fine movement stage device, 81: Exit glass surface, 82: Incident Glass surface, 83: Vortex, 84: Disturbance, 85, 86: Cylindrical lens (convex lens), 87: Mark projection optical system, 88: Mask, 89: Mask illumination system, 90: Light source, 91: Baffle plate, 92: Air conditioning Machine, 93: return duct, 94: mark, 95: image, 96: curved surface member.

Claims (14)

An original stage for moving the original, and
A substrate stage for moving the substrate;
A projection optical system for projecting a pattern of the original onto the substrate,
And original-side laser interferometer for measuring the position of the original stage,
And a substrate-side laser interferometer for measuring the position of said substrate stage,
In scanning exposure apparatus for performing projection to expose a pattern of the original stage and said original while moving the substrate stage and the master stage by feeding back the measured position of the substrate stage in the scanning direction on the substrate,
And the original air-conditioning means for conditioning the measurement optical path by the original-side laser interferometer,
And the substrate-side air conditioning means for conditioning the measurement optical path by the substrate-side laser interferometer, a separately provided,
Also during exposure stand, the exposure is characterized by continuing to move at least either the original stage and said substrate stage device. 2. The exposure apparatus according to claim 1, wherein the original stage is continuously moved during the exposure standby.   The substrate side platen provided with the projection optical system and the original stage, and a base frame that has a plurality of columns and supports the column platen via a damper on each column, 2. An exposure apparatus according to claim 1, further comprising a passage for returning air when the apparatus is arranged in a chamber for air conditioning. A projection optical system for projecting an original pattern onto the substrate; and focus detection means for positioning the substrate at a focus position of the projection optical system. The focus detection means is provided on the substrate disposed at the exposure position. In an exposure apparatus comprising a light projecting means for projecting measurement light and a light receiving means for receiving the measurement light projected thereby and reflected by the substrate,
An exposure apparatus comprising an air conditioner for air-conditioning the optical path of the measurement light, wherein an emission surface or an incident surface of the measurement light in the light projecting means or the light receiving means is a cylindrical surface or a spherical surface. The light projecting means or the light receiving means has an exit glass surface that emits the measurement light or an incident glass surface on which the measurement light is incident, and the exit glass surface or the incident glass surface is substantially parallel to the air blowing direction of the air conditioning means. 5. An exposure apparatus according to claim 4, wherein: 6. An exposure apparatus according to claim 4, wherein an optical path of the measurement light and an air blowing direction of the air conditioning means are substantially orthogonal to each other. As seen in the air blowing direction of the air-conditioning means, there are members adjacent to the light-projecting means or the light-receiving means, before and after the light-projecting means or the light-receiving means, and the exit surface or the incident surface of the light projecting means or the light-receiving means The exposure apparatus according to claim 4 , wherein the cylindrical surface or the spherical surface is configured. Measure the position of the original with the original laser interferometer,
Measure the position of the board with the board side laser interferometer,
Manufacturing a device by projecting to scanning exposure on the substrate through the original and the substrate pattern projection optical system of the original while the measurement position by feeding back the moving the substrate and the original in the scanning direction of the to upon, separately conditioning the measurement optical path by the measurement optical path and the substrate-side laser interferometer according to the original-side laser interferometer,
Even when the exposure stand, a device manufacturing method characterized by continuously moving either the substrate stage for moving the original stage and said substrate moving at least the original. 9. The device manufacturing method according to claim 8, wherein the original stage is continuously moved during the exposure standby. The original stage for moving the original and the projection optical system are provided on a lens barrel surface plate, and this lens barrel surface plate is supported via a plurality of columns provided on the base frame and dampers on each column, and the apparatus is chambered. 10. The device manufacturing method according to claim 8 or 9 , wherein the air conditioning on the substrate side when the air conditioning is arranged in the inside is performed through a return passage provided in a lower portion of the base frame. The measurement light is projected onto the substrate placed at the exposure position by the light projecting means,
The measurement light reflected by the substrate is received by the light receiving means,
Thereby positioning the substrate on the focus position of the projection optical system,
Upon manufacturing the device by exposure projected onto the substrate through a pattern the projection optical system of the original, as well as air-conditioning by the air conditioning unit the optical path of the measurement light, in the light projecting means and said light receiving means The device manufacturing method according to claim 1, wherein the measuring light exit surface or incident surface is a cylindrical surface or a spherical surface. It said light projecting means or said light receiving means has an incident glass surface on which the measuring light exit glass surface or the measuring light emits is incident, substantially the blowing direction of the air of the emission glass face or entrance glass surface and the air conditioning unit The device manufacturing method according to claim 11 , wherein the device is parallel. 13. The device manufacturing method according to claim 11 or 12, wherein an optical path of the measurement light and an air blowing direction of the air conditioning means are substantially orthogonal to each other. In the air blowing direction of the air-conditioning means, a member adjacent to the light-projecting means or the light-receiving means is provided before and after the light-projecting means or the light-receiving means. The device manufacturing method according to claim 12 , wherein the cylindrical surface or the spherical surface is formed.

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