JP2005197445A - Detector, aligner, and exposure method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a detector which has a sufficiently small amount of contaminant emitted into an optical path space. <P>SOLUTION: The detector is equipped with a light guide 12 for transmitting illumination light for illuminating a detected object or detection light which has passed through the detected object. A space through which the prescribed light passes satisfies at least either of the following conditions: an amount of organic substance emitted from the light guide 12 is 100 ng/cm<SP>2</SP>or less, or an amount of ionic substance emitted from the light guide 12 is 50 ng/cm<SP>2</SP>or less. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a detection apparatus including a light guide that transmits illumination light or detection light, an exposure apparatus including the detection apparatus, and an exposure method using the exposure apparatus.

  Conventionally, in an exposure apparatus used in a photolithography process for manufacturing a semiconductor element or the like, a circuit pattern formed on a mask is highly superimposed on a photoresist layer on a wafer (or glass plate or the like) as a photosensitive substrate. In order to transfer with high accuracy, it is necessary to align (align) the mask and each exposure area of the wafer with high accuracy. For this reason, an alignment mark for alignment, that is, a wafer mark is formed in each exposure region of the wafer. In order to detect the position of these wafer marks, for example, an FIA detection system is mounted on the exposure apparatus.

  Here, in the FIA (Field Image Alignment) system, the alignment mark is illuminated with light having a wide wavelength bandwidth supplied from a light source such as a halogen lamp, and the image data of the imaged alignment mark is image-processed to perform alignment. Detect the mark position.

  In the exposure apparatus, it is necessary to perform the projection exposure in a state where the image plane of the projection optical system and each exposure plane of the wafer are aligned with high accuracy. Therefore, in order to detect the alignment state between the image plane of the projection optical system as the reference plane and each exposure surface of the wafer, for example, an alignment AF (autofocus) system is mounted on the exposure apparatus. In the alignment AF system, a light source such as a halogen lamp is used to irradiate the wafer surface with a light beam extending in one direction, and based on the light from the wafer surface illuminated by this light beam, the image plane of the projection optical system The alignment state with each exposure surface of the wafer is detected (see Patent Document 1).

  In addition, since microdevices such as semiconductor devices are formed by overlaying multiple layers of circuit patterns on a wafer coated with a photosensitive material, when projecting and exposing circuit patterns of the second and subsequent layers onto the wafer, It is necessary to accurately perform alignment between each shot area on which a circuit pattern has already been formed on the wafer and the pattern image of the reticle to be exposed, that is, alignment between the wafer and the reticle. For example, a so-called enhanced global alignment (EGA) is a mainstream method for aligning wafers when performing overlay exposure on a single wafer in which shot areas where circuit patterns are exposed are arranged in a matrix. It has become.

  The EGA method designates at least three areas (hereinafter referred to as EGA shots) among a plurality of shot areas formed on a wafer (object), and coordinates positions of alignment marks (marks) attached to the shot areas. Is measured by an alignment sensor. Thereafter, an error parameter (offset, scale, rotation, orthogonality) related to the array characteristics (position information) of the shot area on the wafer is determined based on the measured value and the design value by statistical calculation processing using the least square method or the like. Then, based on the determined parameter values, the design coordinate values are corrected for all shot areas on the wafer, and the wafer stage is stepped according to the corrected coordinate values to position the wafer. It is a method. As a result, the projected image of the reticle pattern and each of the plurality of shot areas on the wafer are processing points set in the shot area (reference points whose coordinate values are measured or calculated, for example, the center of the shot area ) And are overlaid and exposed accurately.

  As an alignment sensor for measuring an alignment mark on a wafer, an index mark formed on a reference member provided on a wafer stage via a reticle alignment mark formed on a reticle and a projection optical system, or formed on a wafer There is a so-called TTR (through-the-reticle) type sensor that detects the alignment mark. The TTR sensor measures, for example, the amount of positional deviation between marks by imaging a reticle alignment mark and a wafer alignment mark (or index mark) imaged via a projection optical system in the same field of view. Yes (see Patent Document 2).

  In addition, as described above, when manufacturing a semiconductor element or the like, since it is necessary to stack different circuit patterns on the substrate in layers, the reticle on which the circuit pattern is drawn and each of the substrates on the substrate It is important to accurately overlay the pattern already formed in the shot area. In order to perform such superposition with high accuracy, it is essential to adjust the optical characteristics of the projection optical system to a desired state.

  As a precondition for adjusting the optical characteristics of the projection optical system, it is necessary to accurately measure the optical characteristics. As a method for measuring the optical characteristics, a measurement mask is formed by illuminating a measurement mask with illumination light. There is also an aerial image measurement device (AIS system) that uses a method (hereinafter referred to as “aerial image measurement method”) that measures an aerial image (projected image) of a pattern for use and calculates optical characteristics based on the measurement result. (See Patent Document 3).

JP 2002-122212 A JP 2002-198292 A JP 2002-198303 A

  By the way, in recent years, the exposure light used tends to be shortened in wavelength with the demand for miniaturization of the pattern shape formed on the substrate. That is, an exposure apparatus using vacuum ultraviolet light having a short wavelength, such as a KrF excimer laser (wavelength 248 nm) or an ArF excimer laser (wavelength 193 nm), is being put into practical use instead of the mercury lamps which have been mainstream. When such vacuum ultraviolet light is used as exposure light, a substance having strong absorption characteristics for light in such a wavelength region such as oxygen molecules, water molecules, carbon dioxide molecules, etc. in the optical path space that is the space through which the exposure light passes ( If there are impurities (absorbing substances), organic component substances, ionic substances, etc. (hereinafter these impurities are called “contaminants”), the exposure light is dimmed and can reach the substrate with sufficient intensity. Therefore, accurate exposure processing cannot be performed.

  As described above, the exposure apparatus is equipped with a detection apparatus such as an FIA system, an AF system, a TTR system, or an AIS system in order to superimpose and transfer the circuit pattern formed on the mask onto the wafer. However, a light guide is used to transmit illumination light supplied to these detection devices or to transmit detection light detected by these detection devices. Here, the light guide is composed of a plurality of optical fiber strands and a light guide tube that accommodates the optical fiber strands. When manufacturing the light guide, a lubricant or an adhesive is used. Contaminants are emitted from the light guide into the optical path space, and the emitted contaminants cause a decrease in the transmittance and reflection due to the decrease in exposure light illuminance, uneven illumination, or clouding of the optical element. This has led to a decrease in exposure processing performance such as a decrease in rate.

  An object of the present invention is to provide a detection apparatus in which contaminants released into an optical path space are sufficiently reduced, an exposure apparatus provided with the detection apparatus, and an exposure method using the exposure apparatus.

The detection apparatus according to claim 1, wherein the detection apparatus includes a light guide that transmits illumination light that illuminates the test object or detection light that passes through the test object. The organic material amount generated from the light guide satisfies at least one condition of 100 ng / cm ² or less and the ionic material amount of 50 ng / cm ² or less.

  According to the detection device of the first aspect, the discharge amount of the organic substance and the ionic substance is reduced with respect to the space through which the predetermined light passes, and at least one of the organic substance and the ionic substance is reduced to the predetermined amount. Can be less than the amount. Therefore, it is possible to prevent a space through which predetermined light passes, for example, a space through which exposure light passes, from being contaminated by an organic substance or an ionic substance.

  According to a second aspect of the present invention, the light guide includes an optical fiber and a light guide tube that accommodates the optical fiber, and a light transmissive member is provided on at least one end surface of the light guide. Features.

  According to the second aspect of the present invention, since the light guide has the light transmissive member on the end face of the light guide, organic substances and ionic substances generated from the light guide are emitted from the end face of the light guide into a predetermined space. Can be prevented appropriately.

  According to a third aspect of the present invention, the light transmissive member seals an end surface of the light guide. According to the detection device of the third aspect, since the end face of the light guide is sealed by the light transmissive member, the organic substance and the ionic substance are surely prevented from being released into the predetermined space from the end face of the light guide. can do.

  According to a fourth aspect of the present invention, the light guide tube is composed of a metal member that maintains the internal space in an airtight state. According to the detection device of the fourth aspect, since the internal space of the light guide is maintained in an airtight state by the metal member, organic substances and ionic substances generated from the light guide are released into the predetermined space. This can be effectively prevented.

  According to a fifth aspect of the present invention, the detection device includes an adjustment mechanism that adjusts the position of the other end of the light guide at one end of the light guide.

  The detection device according to claim 6 is characterized in that the adjustment mechanism includes a mechanism for finely moving the one end of the light guide.

  According to a seventh aspect of the present invention, the detection device is a rigid light guide having a bent shape.

  According to the detection device of the fifth to seventh aspects, the position of the other end portion of the light guide can be adjusted by the adjusting mechanism provided at one end portion of the light guide. Therefore, by adjusting the position of the end of the light guide, stress is generated in the light guide, and in the state where the stress is generated, the light guide is fixed to the substrate stage, so that the substrate stage is distorted. It can be accurately prevented.

  An exposure apparatus according to claim 8 is an exposure apparatus for transferring a mask pattern to a photosensitive substrate using exposure light, and comprises the detection apparatus according to any one of claims 1 to 7. It is characterized by.

  According to the exposure apparatus of the eighth aspect, since the detection apparatus that prevents the contamination by the organic substance or ionic substance generated from the light guide is provided, high-precision exposure can be performed.

  The exposure apparatus according to claim 9, further comprising: a projection optical system that projects the pattern of the mask onto the photosensitive substrate; and a substrate stage on which the photosensitive substrate is placed, and at least one of the light guides The end of is disposed in the substrate stage or in the vicinity of the substrate stage, and the space through which the predetermined light passes is a space on the substrate stage side of the projection optical system.

  According to the ninth aspect of the present invention, the exposure apparatus includes a detection device that prevents contamination of the space on the substrate stage side of the projection optical system by an organic substance or an ionic substance generated from the light guide. Therefore, since the space through which the exposure light passes can be kept clean, high-precision exposure can be realized.

  The exposure apparatus according to claim 10, further comprising: a projection optical system that projects the pattern of the mask onto the photosensitive substrate; and a substrate stage on which the photosensitive substrate is placed, and at least one of the light guides The end of is arranged in the vicinity of the mask, and the space through which the predetermined light passes is a space on the mask side of the projection optical system.

  According to the exposure apparatus of the tenth aspect, the detection apparatus is provided which prevents the space on the mask side of the projection optical system from being contaminated by an organic substance or an ionic substance generated from the light guide. Therefore, since the space through which the exposure light passes can be kept clean, high-precision exposure can be realized.

  An exposure method according to claim 11 is an exposure method using the exposure apparatus according to any one of claims 8 to 10, wherein an illumination step of illuminating the mask using an illumination optical system; A transfer step of transferring the mask pattern onto the photosensitive substrate.

  According to the exposure method of the eleventh aspect, the exposure is performed by the exposure apparatus including the detection device capable of keeping the space through which the exposure light passes in a clean state. Therefore, exposure can be performed with high accuracy, and a precise semiconductor element or the like can be manufactured.

  According to the detection device of the present invention, the emission amount of the organic substance and the ionic substance is reduced with respect to the space through which the predetermined light passes, and at least one of the organic substance and the ionic substance is reduced to a predetermined amount or less. can do. Therefore, it is possible to prevent a space through which predetermined light passes, for example, a space through which exposure light passes, from being contaminated by an organic substance or an ionic substance.

  According to the detection device of the present invention, the position of the other end of the light guide can be adjusted by the adjusting mechanism provided at one end of the light guide. Therefore, by adjusting the position of the end of the light guide, stress is generated in the light guide, and in the state where the stress is generated, the light guide is fixed to the substrate stage, so that the substrate stage is distorted. It can be accurately prevented.

  In addition, according to the exposure apparatus of the present invention, since the detection apparatus that prevents contamination by the organic substance or ionic substance generated from the light guide is provided, high-precision exposure can be performed.

  Further, according to the exposure method of the present invention, since the exposure is performed by the exposure apparatus provided with the detection apparatus capable of keeping the space through which the exposure light passes in a clean state, the exposure can be performed with high accuracy. A precise semiconductor element or the like can be manufactured.

  An exposure apparatus according to a first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a view showing the schematic arrangement of an exposure apparatus according to an embodiment of the present invention. This exposure apparatus is a projection exposure apparatus used in the manufacturing process of semiconductor devices, CCD image sensors, thin film magnetic heads, liquid crystal elements, and the like, and an aerial image measurement apparatus (AIS system) as a detection apparatus and a measured aerial image It is equipped with an analysis device that calculates various aberrations. As shown in FIG. 1, XYZ axes are defined. That is, the Z axis is taken in the optical axis direction parallel to the optical axis of the projection optical system, and the X axis and the Y axis are taken in directions perpendicular to the Z axis and perpendicular to each other. The X axis is a direction parallel to the paper surface of FIG. 1, and the Y axis is a direction perpendicular to the paper surface of FIG.

The exposure apparatus includes a light source (not shown) configured by a KrF excimer laser (248 nm) for supplying exposure light. The exposure apparatus includes an illumination optical system (not shown) that uniformly illuminates the mask M with light from a light source, a projection optical system 2 that forms an image of a pattern drawn on the mask M on the wafer W, and the wafer W It comprises a wafer stage 3 that moves. The mask M is supported on the mask stage 4 in the XY plane. In this exposure apparatus, a KrF excimer laser is used as a light source, but an ArF excimer laser (193 nm) or an F ₂ laser (157 nm) having a shorter wavelength may be used as a light source.

  The projection optical system 2 is composed of a plurality of lenses, and forms an image of the pattern formed on the mask M on the wafer W placed on the wafer stage 3 at a constant magnification. The wafer stage 3 includes an XY stage that can move on the X-axis and the Y-axis on a horizontal plane, a Zθ stage that controls movement in the Z-axis direction and wafer tilt. A wafer holder 5 for sucking and holding the wafer W is provided on the wafer stage 3, and the wafer stage interferometer 6 is used to measure the position of the wafer stage 3, that is, to measure the exposure coordinates on the wafer W. Is provided. In this exposure apparatus, projection exposure is performed while two-dimensionally driving and controlling the wafer W in the XY plane, whereby the transfer pattern of the mask M can be sequentially exposed on each exposure region of the wafer W.

  When measuring the imaging performance of the projection optical system 2, a line-and-space mark aerial image is formed by the projection optical system 2 using a mask on which a line-and-space mark is drawn. An apparatus for measuring an aerial image of the line and space mark is mounted on the wafer stage 3 as shown in FIG. In the vicinity of the wafer holder 5 on the wafer stage 3, an index pattern plate (test object) 7 made of, for example, a glass substrate is provided. Note that the upper surface of the index pattern plate 7 is set to substantially the same height as the wafer W (substantially the same position in the Z direction).

  Of the light that forms the space primary image of the line and space mark, the light that has passed through the transmission part of the index pattern plate 7 is the first relay lens system front group lens 8 disposed inside the wafer stage 3, the optical path deflection. The light passes through a reflection mirror 9, a diffusion plate (diffuser) 10 for diffusing light from the spatial primary image, and a rear lens group 11 of the first relay lens system, and enters a light guide 12.

  Here, as shown in FIG. 2, the light guide 12 includes a plurality of optical fiber strands 12a and a light guide tube 12b having a cylindrical shape that accommodates the plurality of optical fiber strands 12a. . Here, the light guide tube 12b is made of a metal member made of stainless steel or aluminum that maintains the inner space of the light guide 12 in an airtight state, and both end portions of the light guide 12 are provided on both end surfaces of the light guide 12. A light-transmitting member 12c having a disk shape for sealing is disposed. The light transmissive member 12 c is held on the end surface of the light guide 12 by a holding member 12 d for holding the light transmissive member 12 c on the end surface of the light guide 12. The light transmissive member 12 c is disposed on both end surfaces of the light guide 12, but may be disposed on at least one end surface of the light guide 12.

  The light transmitted inside the light guide 12 exits from the exit end, passes through the reflection mirror 13, the second relay lens system front group lens 14, and the opening formed in the wafer stage 3, and passes through the wafer stage 3. Drawn outside. The light extracted to the outside of the wafer stage 3 passes through the second relay lens system rear group lens 15 and is received by a photomultiplier (photomultiplier tube) 16 as a light receiving sensor.

  An output signal from the photomultiplier 16 is sent to the processing device 17. Further, the output signal of the wafer stage interferometer 6 is also sent to the processing device 17. When measuring the intensity distribution of the aerial image, the wafer stage 3 is moved so that the index pattern plate 7 is positioned below the projection optical system 2. In this state, a space primary image of line and space marks is formed on the index pattern plate 7 via the projection optical system 2. In this state, the wafer stage 3 is moved in the X direction, and the photomultiplier 16 receives light from the space primary image that has passed through the index pattern plate 7 with respect to the space primary image of the line and space mark.

  According to the exposure apparatus of the first embodiment, the light guide 12 for transmitting the light that has passed through the transmission part of the index pattern plate 7 is constituted by the metal member that maintains the internal space of the light guide in an airtight state. The light guide tube 12b is provided, and both end faces of the light guide 12 have light-transmitting members that seal both ends of the light guide. Therefore, the organic substance released from the light guide 12 and the ionic substance The amount can be very small. That is, the amount of the light guide positioned in the wafer stage, the organic substance released from the end of the light guide, and the ionic substance can be extremely reduced.

Accordingly, the amount of the organic substance generated from the light guide is 100 ng / cm ² or less and the amount of the ionic substance is 50 ng / cm ^{2 with} respect to the space on the wafer stage (substrate stage) side of the projection optical system through which the exposure light passes. The following conditions can be satisfied, and the space on the wafer stage (substrate stage) side of the projection optical system can be prevented from being contaminated by an organic substance or an ionic substance.

  Next, with reference to the drawings, an exposure apparatus according to the second embodiment of the present invention will be described. The exposure apparatus shown in FIG. 3 includes an excimer laser light source section 20, a beam introducing section 21, a main body section 22 and the like. The main body section 22 is installed on a base 23 via a vibration absorbing mechanism 24.

  The excimer laser light source unit 20 includes, for example, an excimer laser light source that supplies light having a wavelength of 248 nm (KrF excimer laser) or 193 nm (ArF excimer laser) as a light source for supplying exposure light (illumination light). . A substantially parallel light beam emitted from the excimer laser light source unit 20 enters the beam introduction unit 21. Here, since the light beam incident on the beam introducing portion 21 has a strong power, the beam introducing portion 21 is filled with nitrogen gas in order to prevent the optical elements in the beam introducing portion 21 from being clouded. . The light beam incident on the beam introducing portion 21 is reflected by the mirror 25 and enters the half mirror 26. The light transmitted through the half mirror 26 enters the coherence reduction unit 27. The coherence reducing unit 27 has a function of reducing the generation of interference patterns on the reticle R (and thus on the wafer W), which is the irradiated surface.

  The light beam from the coherence reducing unit 27 forms a large number of light sources on the rear focal plane via the first fly-eye lens (first optical integrator) 28. Light from these many light sources illuminates the second fly's eye lens (second optical integrator) 30 in a superimposed manner via the relay optical system 29. Thus, a secondary light source composed of a number of light sources is formed on the rear focal plane of the second fly-eye lens 30. The light beam from the secondary light source is limited by a reticle blind 32 disposed at a position optically conjugate with the reticle R of the main body 22 via a condenser lens 31, and then a mirror 33, lenses 34 and 35, and A reticle (mask) R on which a predetermined transfer pattern is formed is superimposed and uniformly illuminated through a reticle blind imaging system constituted by a mirror 36. The light beam that has passed through the transfer pattern of the reticle R forms an image of the transfer pattern (reticle pattern) on the wafer W, which is a photosensitive substrate, via the projection optical system PL.

  The light reflected by the half mirror 26 of the beam introducing portion 21 enters one end portion of the light guide 40 via the mirror 37 and the lenses 38 and 39. The light guide 40 supplies illumination light (measurement light) having the same wavelength as the exposure light to a reticle alignment system (TTR system) 41 that is a detection device installed in the main body 22. That is, the illumination light having the same wavelength as the exposure light is supplied to the reticle alignment system 41 in a state in which vibration generated in the main body 22 is not easily transmitted to the beam introducing unit 21.

  Here, the light guide 40 has the same configuration as the light guide 12 used in the first embodiment. That is, the light guide 40 includes a plurality of optical fiber strands and a light guide tube having a cylindrical shape that accommodates the plurality of optical fiber strands. Here, the light guide tube is made of a metal member made of stainless steel or aluminum that maintains the inner space of the light guide in an airtight state, and both end portions of the light guide are sealed at both end surfaces of the light guide 40. A light transmissive member having a disk shape is disposed. The light transmissive members are disposed on both end surfaces of the light guide 40, that is, on the end surface on the reticle alignment system (TTR system) 41 side and on the end surface on the beam introduction unit 21 side. It is preferable that the guide 40 is disposed on the end surface on the beam introduction portion 21 side.

  As shown in FIG. 4, the light emitted from the other end of the light guide 40 enters the condenser lens 42. The illumination light that has passed through the condenser lens 42 is once condensed and then incident on the illumination relay lens 43. Illumination light that has become parallel light through the illumination relay lens 43 is reflected upward in the figure on the reflection surface of the mirror 44 and enters the half mirror 45. The illumination light reflected by the half mirror 45 passes through the half mirror 46 and then enters the first objective lens 47. The illumination light condensed by the first objective lens 47 is reflected downward in the figure by the reflecting surface of the epi-illumination mirror 48 and then illuminates the reticle mark (object to be tested) formed on the reticle R. The light transmitted through the transparent portion formed around the reticle mark (alignment mark) of the reticle R is a wafer mark (alignment mark) that is a test object formed on the wafer W via the projection optical system PL. ).

  Reflected light from the wafer mark and reticle mark with respect to the illumination light is incident on the half mirror 46 via the epi-illumination mirror 48 and the first objective lens 47. The light reflected upward in the drawing by the half mirror 46 enters the second objective lens 50 through the mirror 49, and the light through the second objective lens 50 enters the CCD (photoelectric detection element) 51. On the other hand, the light that has passed through the half mirror 46 passes through the half mirror 45 and enters the second objective lens 52, and the light that has passed through the second objective lens 52 enters a CCD (photoelectric detection element) 53.

  A mark image is formed on the light receiving surfaces of the CCDs 51 and 53 based on the reflected light from the wafer mark and the reticle mark with respect to the illumination light. The CCDs 51 and 53 constitute a two-dimensional photoelectric detector that detects the formed mark image by photoelectric conversion.

  The above-described reticle R is placed on a reticle stage (not shown). The reticle stage is driven by a reticle stage control unit (not shown) based on a command from a main control system (not shown). At this time, the movement of the reticle stage is measured by a reticle interferometer (not shown) and a movable mirror (not shown) provided on the reticle stage.

  On the other hand, the wafer W is vacuum chucked by a wafer holder (not shown) on a wafer stage (substrate stage) WS. Wafer stage WS is driven by a wafer stage controller (not shown) based on a command from a main control system (not shown). At this time, the movement of the wafer stage WS is measured by a wafer interferometer (not shown) and a moving mirror (not shown) provided on the wafer stage WS.

  According to the exposure apparatus of the second embodiment, the light guide 40 for supplying illumination light to the reticle alignment system (TTR system) 41 is constituted by a metal member that maintains the internal space of the light guide in an airtight state. The light guide tube is provided, and both end faces of the light guide 40 have light-transmitting members that seal both ends of the light guide, so that the amount of organic substances and ionic substances emitted from the light guide 40 Can be extremely reduced. That is, the amount of the light guide located near the reticle, the organic substance released from the end of the light guide, and the ionic substance can be extremely reduced.

Therefore, the condition that the amount of organic substance generated from the light guide 40 is 100 ng / cm ² or less and the amount of ionic substance is 50 ng / cm ² or less with respect to the reticle R side space of the projection optical system through which the exposure light passes. The space on the reticle side of the projection optical system can be prevented from being contaminated by an organic substance or an ionic substance.

  3 is an off-axis detecting device that detects the position of the wafer W and the position of the reference mark plate FM (reference position) along a plane perpendicular to the optical axis AX of the projection optical system PL. , A detection apparatus for detecting the position of the wafer W along the direction of the optical axis AX of the projection optical system PL. And an oblique incidence type two-dimensional autofocus system (hereinafter referred to as AF system).

  Here, a light guide (not shown) is used to supply illumination light to the FIA system. A light guide (not shown) is used to supply illumination light to the AF irradiation system A1 and to propagate detection light from the AF detection system A2. The light guide used in the FIA system and the AF system has the same configuration as the light guide 12 used in the first embodiment. That is, the light guide includes a plurality of optical fiber strands and a light guide tube having a cylindrical shape that accommodates the plurality of optical fiber strands. Here, the light guide tube is made of a metal member made of stainless steel or aluminum that maintains the inner space of the light guide in an airtight state, and a circle that seals both ends of the light guide is formed on both end faces of the light guide. A light transmissive member having a plate shape is disposed. The light transmissive member is disposed on both end faces of the light guide, but may be disposed on at least one end face of the light guide.

  According to the exposure apparatus of the second embodiment, the light guide used in the FIA system and the AF system includes the light guide tube configured by the metal member that maintains the inner space of the light guide in an airtight state, Since both end faces of the guide have light-transmitting members that seal both ends of the light guide, the amount of organic substances and ionic substances released from the light guide can be extremely reduced. That is, the amount of the light guide positioned near the wafer stage, the organic substance released from the end of the light guide, and the ionic substance can be extremely reduced.

Therefore, with respect to the space on the wafer stage side of the projection optical system through which the exposure light passes, the amount of organic substance generated from the light guide 40 is 100 ng / cm ² or less and the amount of ionic substance is 50 ng / cm ² or less. And the space on the wafer stage side of the projection optical system can be prevented from being contaminated by an organic substance or an ionic substance.

  Next, an exposure apparatus according to a third embodiment of the present invention will be described with reference to the drawings. FIG. 5 is a view showing the schematic arrangement of the exposure apparatus according to the embodiment of the present invention. This exposure apparatus is equipped with an aerial image measuring device as a detection device and an analysis device for obtaining various aberrations from the measured aerial image. As shown in FIG. 5, XYZ axes are defined. That is, the Z axis is taken in the optical axis direction parallel to the optical axis AX1 of the projection optical system, and the X axis and the Y axis are taken in directions orthogonal to the Z axis and perpendicular to each other. The X axis is a direction parallel to the paper surface of FIG. 5, and the Y axis is a direction perpendicular to the paper surface of FIG.

The exposure apparatus includes a light source (not shown) configured by a KrF excimer laser (248 nm) for supplying exposure light. The exposure apparatus includes an illumination optical system (not shown) that uniformly illuminates the mask M1 with light from the light source, a projection optical system PL1 that forms an image of the pattern drawn on the mask M1 on the wafer W1, and the wafer W1. The wafer stage WS1 is configured to move. In this exposure apparatus, a KrF excimer laser is used as a light source, but an ArF excimer laser (193 nm) or F ₂ laser (157 nm) having a shorter wavelength may be used as a light source.

  Projection optical system PL1 includes a plurality of lenses, and forms an image of the pattern drawn on mask M1 on wafer W1 placed on wafer stage WS1 at a constant magnification. Wafer stage WS1 includes an XY stage that can move along the X axis and Y axis on a horizontal plane, a Zθ stage that controls movement in the Z axis direction, and tilt of the wafer. A wafer holder WH1 for sucking and holding the wafer W1 is provided on the wafer stage WS1. In this exposure apparatus, projection exposure is performed while two-dimensionally driving and controlling the wafer in the XY plane, whereby the transfer pattern of the mask M1 can be sequentially exposed on each exposure region of the wafer W1.

  When measuring the imaging performance of the projection optical system PL1, a space image of the line and space mark is formed by the projection optical system PL1 using a mask on which the line and space mark is drawn. As shown in FIG. 5, the aerial image measuring apparatus for measuring the aerial image of the line and space mark is mounted on the wafer stage WS1. In the vicinity of wafer holder WH1 on wafer stage WS1, an index pattern plate (test object) 60 made of, for example, a glass substrate is provided. Note that the upper surface of the index pattern plate 60 is set at substantially the same height as the wafer W (substantially the same position in the Z direction).

  Of the light that forms the space primary image of the line and space mark, the light that has passed through the transmission part of the index pattern plate 60 is a relay lens system 61 disposed inside the wafer stage WS1 and a reflection mirror 62 for deflecting the optical path. Through the light guide 63.

  Here, the light guide 63 is a rigid light guide having a bent shape as shown in FIG. 6, but the structure of the light guide tube and the structure of the end portion of the light guide are used in the first embodiment. The light guide 12 has the same configuration. That is, the light guide 63 includes a plurality of optical fiber strands and a light guide tube having a cylindrical shape that accommodates the plurality of optical fiber strands. Here, the light guide tube is made of a metal member made of stainless steel or aluminum that maintains the inner space of the light guide 63 in an airtight state, and both end portions of the light guide are sealed at both end surfaces of the light guide 63. A light transmissive member having a disk shape is disposed.

  The light transmitted inside the light guide 63 is emitted from its exit end, and is drawn out of the wafer stage WS1 through the reflection mirror 64 and the relay lens system 65. The light extracted to the outside of the wafer stage WS1 is incident on and received by a photomultiplier (photomultiplier tube) 69 as a light receiving sensor via the reflecting mirror 66, the relay lens group 67, and the reflecting mirror 68.

  When measuring the intensity distribution of the aerial image, the wafer stage WS1 is moved so that the index pattern plate 60 is positioned below the projection optical system PL1. In this state, a space primary image of line and space marks is formed on the index pattern plate 60 via the projection optical system PL1. In this state, the wafer stage WS1 is moved in the X direction, and the photomultiplier 69 receives light from the space primary image that has passed through the index pattern plate 60 with respect to the space primary image of the line and space mark.

  In this aerial image measurement device, an adjustment mechanism 72 that finely adjusts the position of the light receiving unit side end 71 of the light guide 63 is provided at the light emitting unit side end 70 of the light guide 63. An end portion 70 on the light emitting portion side of the light guide 63 is inserted into a horizontal opening of an optical member holding portion 72 a having an L-shaped internal space that houses the reflection mirror 64 and the relay lens system 65. The optical member holding portion 72a is configured to be rotatable on the wafer stage WS1 in the direction of the arrow a shown in FIG. 6, and the vertical position of the end portion 70 on the light emitting portion side of the light guide 63 is defined by the pin 72b. The horizontal position of the end portion 70 on the light emitting portion side of the light guide 63 is defined by the pin 72c, and is fixed to the horizontal opening of the optical member holding portion 72a.

  As shown in FIG. 6, by rotating the optical member holding portion 72a in the direction of arrow a, the position of the end portion 71 on the light receiving portion side of the light guide 63 can be moved in the direction of arrow a ′. Further, the vertical position of the end portion 71 of the light guide 63 on the light receiving portion side can be moved by changing the vertical position of the end portion 70 of the light guide 63 on the light emitting portion side by the pin 72b. By changing the horizontal position of the light emitting portion side end portion 70 of the light guide 63 by the pin 72c, the position of the light receiving portion side end portion 71 of the light guide 63 can be moved in the arrow b 'direction.

  Further, the position of the light receiving portion side end portion 71 of the light guide 63 is moved in the direction of arrow c ′ by moving the light emitting portion side end portion 70 of the light guide 63 in the direction of arrow c shown in FIG. By rotating the light emitting portion side end 70 of the light guide 63 in the direction of arrow d shown in FIG. 6, the light receiving portion side end 71 of the light guide 63 can be rotated in the direction of arrow d ′. it can.

  In the aerial image measuring apparatus of the exposure apparatus according to the third embodiment, the position of the end of the light guide 63 on the light receiving unit side is finely adjusted by finely moving the end of the light guide 63 on the light emitting unit side. Since the adjusting mechanism 72 is provided, the position of the rigid light guide 63 having a bent shape on the light receiving portion side can be adjusted without deforming the ride guide. Therefore, by adjusting the position of the end portion of the ride guide, stress is generated in the light guide, and in the state where the stress is generated, the light guide is fixed to the substrate stage, so that the substrate stage is distorted. It can be accurately prevented.

In each of the above-described embodiments, a light guide including a plurality of optical fiber strands and a light guide tube that accommodates the plurality of optical fiber strands is used. Alternatively, a light guide composed of a hollow tube made of glass or metal may be used. Even in this case, the amount of the organic substance generated from the light guide with respect to the space on the reticle R side of the projection optical system through which the exposure light passes or the space on the substrate stage side of the projection optical system is 100 ng / cm ² or less, In addition, the amount of ionic substances can satisfy the condition of 50 ng / cm ² or less, and the space on the reticle side of the projection optical system or the space on the substrate stage side of the projection optical system is contaminated with organic substances or ionic substances. This can be prevented.

In each of the above-described embodiments, the amount of the organic substance generated from the light guide is 100 ng with respect to the reticle side space of the projection optical system through which the exposure light passes or the space on the substrate stage side of the projection optical system. / Cm ² or less and an ionic substance amount of 50 ng / cm ² or less, but with respect to the reticle side space of the projection optical system through which the exposure light passes or the space on the substrate stage side of the projection optical system The space on the reticle side of the projection optical system or the projection by satisfying at least one of the conditions that the amount of organic substance generated from the light guide is 100 ng / cm ² or less and the amount of ionic substance is 50 ng / cm ² or less. It is possible to prevent the space on the substrate stage side of the optical system from being contaminated with an organic substance or an ionic substance.

  Hereinafter, with reference to the flowchart of FIG. 7, a semiconductor as a micro device that forms a predetermined circuit pattern on a wafer or the like as a photosensitive substrate using the exposure apparatus according to the first to third embodiments of the present invention. A device manufacturing method will be described.

  First, in step S301 in FIG. 7, a metal film is deposited on one lot of wafers. In the next step S302, a photoresist is applied on the metal film on the wafer of one lot. Thereafter, in step S303, using the projection exposure apparatus according to the first to third embodiments of the present invention, the image of the pattern on the mask is transferred to the one lot via the projection optical system (projection optical module). Are sequentially transferred to each shot area on the wafer. In other words, the reticle and the wafer are relatively aligned by the reticle alignment system, and the reticle transfer pattern is exposed on the wafer. Thereafter, in step S304, the photoresist on the one lot of wafers is developed, and in step S305, the resist pattern is etched on the one lot of wafers to form a pattern on the mask. Corresponding circuit patterns are formed in each shot area on each wafer. Thereafter, a device pattern such as a semiconductor element is manufactured by forming a circuit pattern of an upper layer. According to the semiconductor device manufacturing method described above, since the exposure is performed by the exposure apparatus provided with the detection apparatus capable of keeping the space through which the exposure light passes in a clean state, a semiconductor device having an extremely fine circuit pattern is obtained. High throughput can be obtained.

  In the projection exposure apparatus according to the first to third embodiments of the present invention, a liquid crystal as a micro device is formed by forming a predetermined pattern (circuit pattern, electrode pattern, etc.) on a plate (glass substrate). A display element can also be obtained. Hereinafter, a method for manufacturing a liquid crystal display element will be described with reference to the flowchart of FIG. In FIG. 8, in the pattern forming step S401, the projection exposure apparatus according to the first to third embodiments of the present invention is used to transfer and expose the mask pattern onto a photosensitive substrate (such as a glass substrate coated with a resist). A so-called photolithography process is performed. That is, relative alignment between the mask and the plate is performed by the reticle alignment system, and the transfer pattern of the mask is exposed on the plate. By this photolithography process, a predetermined pattern including a large number of electrodes and the like is formed on the photosensitive substrate. Thereafter, the exposed substrate undergoes steps such as a developing step, an etching step, and a resist stripping step, whereby a predetermined pattern is formed on the substrate, and the process proceeds to the next color filter forming step S402.

  Next, in the color filter forming step S402, a large number of sets of three dots corresponding to R (Red), G (Green), and B (Blue) are arranged in a matrix, or three of R, G, and B are arranged. A color filter is formed by arranging a plurality of striped filter sets in the horizontal scanning line direction. Then, after the color filter formation step S402, a cell assembly step S403 is executed. In the cell assembly step S403, a liquid crystal panel (liquid crystal cell) is assembled using the substrate having the predetermined pattern obtained in the pattern formation step S401, the color filter obtained in the color filter formation step S402, and the like. In the cell assembly step S403, for example, liquid crystal is injected between the substrate having the predetermined pattern obtained in the pattern formation step S401 and the color filter obtained in the color filter formation step S402, and a liquid crystal panel (liquid crystal cell ).

  Thereafter, in a module assembly step S404, components such as an electric circuit and a backlight for performing a display operation of the assembled liquid crystal panel (liquid crystal cell) are attached to complete a liquid crystal display element. According to the above-described method for manufacturing a liquid crystal display element, since exposure is performed by an exposure apparatus provided with a detection apparatus that can keep a space through which exposure light passes in a clean state, a liquid crystal having an extremely fine circuit pattern. A display element can be obtained with high throughput.

1 is a schematic block diagram of an exposure apparatus according to a first embodiment of the present invention. It is a figure for demonstrating the structure of the light guide which concerns on embodiment of this invention. It is a schematic block diagram of the exposure apparatus which concerns on 2nd Embodiment of this invention. It is a figure which shows the structure of the reticle alignment system mounted in the exposure apparatus which concerns on the 2nd Embodiment of this invention. It is a schematic block diagram of the exposure apparatus which concerns on the 3rd Embodiment of this invention. It is a figure for demonstrating position adjustment of the edge part of the light guide of the aerial image measuring device mounted in the exposure apparatus which concerns on the 3rd Embodiment of this invention. It is a flowchart explaining the manufacturing method of the microdevice which concerns on embodiment of this invention. It is a flowchart explaining the manufacturing method of the microdevice which concerns on embodiment of this invention.

Explanation of symbols

2 Projection optical system 3 Wafer stage 7 Index pattern plate 12, 40, 63 Light guide 41 Reticle alignment system R Reticle (mask)
W Wafer AF Autofocus system 72 Adjustment mechanism

Claims (11)

In a detection apparatus including a light guide that transmits illumination light that illuminates a test object or detection light that passes through the test object,
The organic material amount generated from the light guide satisfies at least one condition of 100 ng / cm ² or less and the ionic material amount of 50 ng / cm ² or less with respect to a space through which predetermined light passes. Detection device. The light guide includes an optical fiber and a light guide tube that accommodates the optical fiber,
The detection device according to claim 1, further comprising a light transmissive member on at least one end surface of the light guide.   The detection device according to claim 2, wherein the light transmissive member seals an end surface of the light guide.   The detection device according to claim 2, wherein the light guide tube is configured by a metal member that maintains an internal space in an airtight state.   5. The detection device according to claim 1, further comprising: an adjustment mechanism that adjusts a position of the other end of the light guide at one end of the light guide.   The detection device according to claim 5, wherein the adjustment mechanism includes a mechanism that finely moves the one end of the light guide.   The detection device according to claim 5, wherein the light guide is a rigid light guide having a bent shape. In an exposure apparatus that transfers a mask pattern to a photosensitive substrate using exposure light,
An exposure apparatus comprising the detection device according to any one of claims 1 to 7. A projection optical system that projects the pattern of the mask onto the photosensitive substrate;
A substrate stage on which the photosensitive substrate is placed;
At least one end of the light guide is disposed in the substrate stage or in the vicinity of the substrate stage,
9. The exposure apparatus according to claim 8, wherein the space through which the predetermined light passes is a space on the substrate stage side of the projection optical system. A projection optical system that projects the pattern of the mask onto the photosensitive substrate;
A substrate stage on which the photosensitive substrate is placed;
At least one end of the light guide is disposed in the vicinity of the mask;
The exposure apparatus according to claim 8 or 9, wherein the space through which the predetermined light passes is a space on the mask side of the projection optical system. An exposure method using the exposure apparatus according to any one of claims 8 to 10,
An illumination process for illuminating the mask using an illumination optical system;
A transfer step of transferring the pattern of the mask onto the photosensitive substrate.

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