Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/70—Microphotolithographic exposure; Apparatus therefor
  • G03F7/70483—Information management; Active and passive control; Testing; Wafer monitoring, e.g. pattern monitoring
  • G03F7/70591—Testing optical components
  • G03F7/706—Aberration measurement
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/70—Microphotolithographic exposure; Apparatus therefor
  • G03F7/70691—Handling of masks or workpieces
  • G03F7/70716—Stages
  • G03F7/70725—Stages control
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/70—Microphotolithographic exposure; Apparatus therefor
  • G03F7/70691—Handling of masks or workpieces
  • G03F7/70733—Handling masks and workpieces, e.g. exchange of workpiece or mask, transport of workpiece or mask
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F9/00—Registration or positioning of originals, masks, frames, photographic sheets or textured or patterned surfaces, e.g. automatically
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F9/00—Registration or positioning of originals, masks, frames, photographic sheets or textured or patterned surfaces, e.g. automatically
  • G03F9/70—Registration or positioning of originals, masks, frames, photographic sheets or textured or patterned surfaces, e.g. automatically for microlithography
  • G03F9/7003—Alignment type or strategy, e.g. leveling, global alignment
  • G03F9/7046—Strategy, e.g. mark, sensor or wavelength selection
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F9/00—Registration or positioning of originals, masks, frames, photographic sheets or textured or patterned surfaces, e.g. automatically
  • G03F9/70—Registration or positioning of originals, masks, frames, photographic sheets or textured or patterned surfaces, e.g. automatically for microlithography
  • G03F9/7088—Alignment mark detection, e.g. TTR, TTL, off-axis detection, array detector, video detection

Definitions

• the present invention relates to a projection exposure apparatus.
• Patent document 1 JP Patent Publication 9-50959A describes an embodiment of a projection exposure apparatus that includes a substrate mark detection optical system for detecting a substrate mark by illuminating a substrate mark with a first detection light of a broadband wavelength without passing through a projection optical system and receiving the first detection light from the substrate mark without passing through a projection optical system, a mask mark detection optical system for detecting a mask mark by illuminating a mask mark with a second detection light via the projection optical system and receiving light from the mask mark, and a correction means disposed between the mask and the substrate for correcting chromatic aberration (axial chromatic aberration, chromatic aberration of magnification (distortion), etc.) of the projection optical system for the second detection light reflected by the substrate. That is, Patent document 1 describes an embodiment in which aberration of the projection optical system is detected and corrected by comparing a mark provided on the mask with a mark provided on the projection exposure position side.
• Patent document 2 JP Patent Publication No. 10-172907 describes an embodiment of a projection exposure apparatus that includes a first alignment system that irradiates a first reference mark arranged on the image plane side of the projection optical system with a first alignment light having a different wavelength from the exposure illumination light and detects optical information generated from the first reference mark via the projection optical system, and a second alignment system that irradiates a mark on a mask and a second reference mark arranged on the image plane side of the projection optical system with a second alignment light having approximately the same wavelength as the exposure illumination light, detects the two marks via the projection optical system, and detects the amount of offset caused by chromatic aberration. That is, Patent Document 2 describes an embodiment in which aberration in the projection optical system is detected and corrected by comparing a mark on the mask with a mark on the projection exposure position side.
• Patent document 3 (US Pat. No. 7,403,264 B2) describes an embodiment of a lithographic projection apparatus having a projection system for projecting a patterned beam onto a target portion of a substrate to form an image, predicting a change in projection system aberration over time for measured aberration values, determining an application-specific effect of the predicted projection system aberration change on a parameter of at least one image for a selected pattern, generating a control signal specific to the selected pattern according to the predicted projection system aberration change and the application-specific effect on the parameter of the at least one image, and responding to the control signal to compensate for the application-specific effect of the predicted projection system aberration change on the image.
• Patent document 4 JP Patent Publication No. 11-168062 describes a projection exposure position that includes a substrate stage, a projection optical system, a first mark detection means having a detection center at a first position outside the projection field of the projection optical system and spaced a fixed distance from the optical axis of the projection optical system and capable of optically detecting a mark on a photosensitive substrate, and a second mark detection means for optically detecting a specific mark that exists at a substantially fixed second position within the field of the projection optical system among a plurality of marks on a mask, a first reference mark that is provided on a part of the substrate stage and can be detected by the first mark detection means, and a second mark detection means that detects a specific mark via the projection optical system.
• the patent document 4 describes a reference mark plate on which a second reference mark detectable by the first mark detection means is arranged in a fixed positional relationship according to the distance between the first position and the second position, a first positioning means for positioning the substrate stage so that the second reference mark is detected by the second mark detection means, a second positioning means for detecting both a specific mark on the mask and the second reference mark by the second mark detection means and positioning the mask stage so that the two marks are in a predetermined positional relationship, and a first mark detection means for detecting the amount of positional deviation between the detection center and the first reference mark and storing the amount of positional deviation as a baseline error amount. That is, Patent Document 4 describes an embodiment for detecting the amount of positional deviation between a first reference mark on a photosensitive substrate and the detection center of the first mark detection means.
• Patent document 7 JP Patent Publication 9-260273A describes an exposure apparatus that includes a first measuring means for observing an alignment mark on a photosensitive substrate through a projection optical system and measuring the deviation from its own reference mark, a stage that mounts a photosensitive substrate and drives it in parallel and perpendicular directions to the optical axis of the projection optical system, a second measuring means for measuring the parallel and perpendicular drive positions of the stage, a third measuring means for superimposing and simultaneously measuring a pattern on a mask, a pattern on the photosensitive substrate, and a calibration pattern provided on the first stage for use in calibrating the pattern on the mask and the first measuring means through a projection lens, respectively, a fourth measuring means that includes a mask reference mark and simultaneously measures the mark on the mask and the mask reference mark by superimposing them, and a mask driving means for driving the mask in the X, Y, and ⁇ directions. That is, Patent document 7 describes an aspect in which the reference pattern on the mask side and the calibration mark are aligned using an on-axis
• the most important performance of a projection exposure tool is the resolution of the pattern to be formed and the alignment accuracy.
• high productivity is also required.
• the lens that projects the mask pattern is sensitive to changes in air pressure and temperature, and its lens performance changes successively due to changes in air pressure and temperature during production operation, as well as the light energy used during exposure. Since these changes have a significant effect on exposure performance, it is necessary to measure or predict these changes during production operation and make various corrections to keep performance constant at all times. Correction control requires technology to measure changes in the performance (aberration) of the projection lens, and various methods have been developed to measure individual aberrations. However, conventional technology for measuring these aberrations with high precision requires stopping the production process to make measurements, which significantly reduces productivity.
• An object of the present invention is to measure changes in the performance of a projection lens with high accuracy without affecting the takt time.
• the first aspect is a projection exposure apparatus that projects a mask pattern onto a substrate transported to a projection exposure position via a projection optical system, the mask being formed with a mask side aberration detection mark for detecting aberration or aberration variation of the projection optical system, the alignment mark imaging unit imaging an alignment mark provided on the substrate, a substrate stage on which the substrate is mounted, a reference mask being formed with a reference mask side aberration detection mark for detecting aberration or aberration variation of the projection optical system and a positional deviation detection mark for measuring a positional deviation relative to a reference position of the alignment mark imaging unit, and the mask side aberration detection mark and the reference mask side aberration detection mark are imaged from the opposite side of the projection optical system across the reference mask.
• the projection exposure apparatus includes an aberration/positional deviation measurement stage on which an aberration detection mark imaging unit is mounted, a transport control unit that controls transport of the substrate stage and the aberration/positional deviation measurement stage so that the aberration/positional deviation measurement stage is positioned at the projection exposure position while the substrate stage is positioned at the substrate exchange position, and an imaging control unit that controls imaging of the alignment mark imaging unit and the aberration detection mark imaging unit so that the alignment mark imaging unit images the positional deviation detection mark and the aberration detection mark imaging unit images the mask side aberration detection mark and the reference mask side aberration detection mark while the transport control unit positions the aberration/positional deviation measurement stage at the projection exposure position.
• the second aspect is a projection exposure apparatus according to the first aspect, in which the imaging control unit controls imaging every time the substrate mounted on the substrate stage is replaced at the substrate replacement position.
• FIGS. 2A and 2B are diagrams showing a portion of the configuration of a projection exposure apparatus 200 according to an embodiment.
• FIGS. 2A and 2B are views of FIG. 1 taken from arrow A.
• the projection exposure apparatus 200 includes a lamp house 210, a mask blind projection optical system 220, a mask stage 230, a projection optical system 20, a substrate stage 50, an aberration and positional deviation measurement stage 80, a substrate transport unit 250, a substrate exchange unit 260, a mask library 270, a mask transport articulated robot 280, and a suspension 290.
• the mask 10 is placed and held on the mask stage 230.
• the projection optical system 20 focuses the pattern image drawn on the irradiation area AR1 of the mask 10 onto the projection exposure area AR2 of the substrate 30 transported to the projection exposure position P1.
• the substrate 30 is placed and held on the substrate stage 50.
• the aberration/positional deviation measurement stage 80 is a stage for measuring the aberration or aberration variation of the projection optical system 20 and the positional deviation of the alignment mark imaging unit 40, and the reference mask 60 is placed and held on it.
• the substrate replacement unit 260 replaces the substrate 30 on the substrate stage 50 positioned at the substrate replacement position P2.
• the mask library 270 is a storage shelf that stores multiple replacement masks 30 while preventing foreign matter from adhering to the surface of the masks 10, and stores multiple masks 10 lined up with spaces between them.
• the mask transport articulated robot 280 is a robot that handles the replacement of the mask 10 on the mask stage 230 in response to a request to change the projection exposure pattern image formed on the substrate 30.
• the mask transport articulated robot 280 transports the mask 10 from the mask stage 230 and retrieves a new mask 10 from the mask library 270 and transports it onto the mask stage 230 by controlling the drive of each axis of the robot and controlling the gripping and releasing of the hand 281 at the tip of the arm.
• the suspension 290 is provided between the stand 170 on which the projection optical system 20, substrate stage 50, and mask stage 230 are mounted, and the floor of the clean room.
• the suspension 290 maintains the positional relationship between the projection optical system 20, substrate 30, and mask 10 with high precision, and prevents or suppresses the transmission of vibrations to the projection optical system 20, substrate stage 50, and mask stage 230.
• the projection exposure apparatus 200 projects the pattern of the mask 10 onto the substrate 30 that has been transported to the projection exposure position P1 via the projection optical system 20.
• the projection exposure apparatus 200 includes a mask 10, a projection optical system 20, a substrate 30, an alignment mark imaging unit 40, a substrate stage 50, a reference mask 60, an aberration detection mark imaging unit 70, an aberration and positional deviation measurement stage 80, a transport control unit 90, an imaging control unit 100, an aberration and positional deviation measurement unit 110, and an aberration and positional deviation correction unit 120.
• the transport control unit 90, the imaging control unit 100, the aberration and positional deviation measurement unit 110, and the aberration and positional deviation correction unit 120 constitute a controller 190 of the projection exposure apparatus 200.
• FIG. 3A shows an example of the configuration of the mask 10.
• FIG. 3A is a view of the mask 10 from above.
• the mask 10 is an original plate for an exposure image, in which a projection pattern PT1 is drawn as a circuit pattern in an irradiation area AR1 on a glass substrate, for example.
• a projection pattern PT1 is drawn as a circuit pattern in an irradiation area AR1 on a glass substrate, for example.
• mask-side aberration detection marks M11, M12, M13, and M14 are formed on the mask 10.
• the mask-side aberration detection marks M11, M12, M13, and M14 are marks for detecting the aberration R or aberration variation ⁇ R of the projection optical system 20.
• the mask-side aberration detection marks M11, M12, M13, and M14 are formed in locations outside the irradiation area AR1.
• the mask-side aberration detection marks M11 and M12 are marks for detecting misalignment of the mask 10, and the parts that do not transmit the illumination light IL are drawn as, for example, a circle or ellipse filled in black.
• the mask-side aberration detection marks M13 and M14 are each marks for focus detection, and are drawn as, for example, a row of multiple black lines with a width of 5 ⁇ m (parts that do not transmit the illumination light IL) and spacing between each line (parts that transmit the illumination light IL).
• the mask-side aberration detection marks M11 and M12 may have any shape or pattern as long as they are capable of detecting the positional deviation of the mask 10.
• the mask-side aberration detection marks M11 and M12 may be cross-shaped.
• FIG. 4 shows an example of the configuration of the projection optical system 20.
• FIG. 5 is a view from above the substrate 30, showing each projection area. The following explanation will be given with reference to FIGS. 3A, 4, and 5.
• the image of the irradiation area AR1 of the mask 10 shown in FIG. 3A is projected onto the projection area AR2 on the substrate 30 shown in FIG. 5.
• the exposure position is controlled so that the projection exposure pattern PT2 is sequentially exposed onto each projection area AR2 on the substrate 30.
• the exposure position is controlled by driving the substrate stage 50 in the X and Y directions.
• FIG. 5 shows the positional relationship between the alignment mark imaging unit 40 (described later) and the alignment marks M31.
• Five alignment marks M31 are arranged along the Y-axis direction, which is the arrangement direction of the alignment mark imaging unit 40, and four alignment marks M31 are arranged along the X-axis direction.
• the alignment marks M31 are arranged, for example, at the four corners of each of the eight rectangular projection areas AR2.
• the alignment mark imaging unit 40 captures an image of the alignment mark M31 provided on the substrate 30.
• the alignment mark imaging unit 40 is composed of, for example, a microscope camera with a digital camera attached to a microscope. As shown in FIG. 5, five alignment mark imaging units 40 are arranged along the Y-axis direction so that each of the five alignment marks M31 arranged along the Y-axis direction on the substrate 30 can be imaged from above.
• the captured image signal S1 indicating the image captured by the alignment mark imaging unit 40 is transmitted to the imaging control unit 100 wirelessly or via wired connection.
• the substrate stage 50 places and holds the substrate 30 and is driven by the substrate transport unit 250 in the three-dimensional directions of X, Y, and Z, as well as in tilt directions around the X and Y axes and in a rotational direction around the Z axis.
• the substrate 30 on the substrate stage 50 is replaced at the substrate replacement position P2 by the substrate replacement unit 260.
• the substrate replacement unit 260 is configured to include a substrate transport arm 262 equipped with an adsorption pad 261.
• the substrate 30 is gripped by the adsorption pad 261, and the substrate transport arm 262 is driven and controlled to load and unload the substrate 30.
• the projection exposure pattern PT2 is sequentially exposed onto each projection area AR2 of the substrate 30 using a step-and-repeat method in which the substrate stage 50 is driven in the X and Y directions.
• the reference mask 60 is placed and mounted on the aberration and positional deviation measurement stage 80.
• FIG. 6A shows an example of the configuration of the reference mask 60.
• FIG. 6A shows the reference mask 60 as viewed from above.
• the positional deviation detection mark M63 is a mark for measuring the positional deviation ⁇ Q from the reference position Q0 of the alignment mark imaging unit 40.
• the reference mask side aberration detection marks M61, M62 are marks for detecting the relative positions of the mask side aberration detection marks M11, M12 as a positional deviation of the mask 10, and for example, the portions that do not transmit the illumination light IL are drawn in the shape of an elliptical or circular frame.
• the reference mask side aberration detection marks M61, M62 can adopt any shape or pattern as long as they detect the positional deviation of the mask 10.
• the reference mask side aberration detection marks M61, M62 may be ones in which the portions that do not transmit the illumination light IL are formed in the shape of a square frame, as shown in FIG. 6C.
• the misalignment detection mark M63 is drawn, for example, in a checkered pattern along the arrangement direction (Y-axis direction) of the alignment mark imaging section 40.
• the misalignment detection mark M63 may have any shape or pattern as long as it can measure the misalignment ⁇ Q of the alignment mark imaging section 40.
• the misalignment detection mark M63 may be drawn in the form of a scale along the arrangement direction (Y-axis direction) of the alignment mark imaging section 40 as shown in FIG. 6D.
• the aberration detection mark imaging unit 70 is mounted on the aberration/positional deviation measurement stage 80.
• the projection exposure pattern PT2 is sequentially exposed onto each projection area AR2 on the substrate 30, as shown in FIG. 5.
• the substrate stage 50 is transported to the substrate exchange position P2 by the transport control unit 90, and the aberration/position deviation measurement stage 80 is transported to the projection exposure position P1.
• the procedure proceeds to the substrate replacement process and aberration and positional deviation correction process S12. If there is a need to replace the mask 10 (determination Y in S16), the procedure returns to the mask replacement and setting process S11.
• the substrate stage 50 and the aberration/positional deviation measurement stage 80 are separate entities, but the substrate stage 50 and the aberration/positional deviation measurement stage 80 may be integrated.
• FIGS. 8A and 8B correspond to FIGS. 2A and 2B, respectively, and show an example of the configuration of a projection exposure apparatus 200 in which the substrate stage 50 and the aberration/positional deviation measurement stage 80 are configured as an integrated stage 86 via a connecting member 85.
• the transport control unit 90 controls transport by the substrate transport unit 250 of the stage 86 so that the substrate 30 is positioned at the substrate exchange position P2 and the reference mask 60 is positioned at the projection exposure position P1.
• the transport control unit 90 controls transport by the substrate transport unit 250 of the stage 86 so that the substrate 30 is positioned at the projection exposure position P1 and the reference mask 60 is positioned at the retreat position P3.
• the aberration R or aberration variation ⁇ R of the projection optical system 20 is measured, and the positional deviation ⁇ Q of the alignment mark imaging unit 40 is measured.
• This makes it possible to suppress the aberration R or aberration variation ⁇ R of the projection optical system 20 without affecting the takt time of the substrate exposure, and to suppress the deterioration of the alignment accuracy of the substrate 30, thereby maintaining high alignment accuracy. Therefore, according to the embodiment, it is possible to provide to the market a projection exposure apparatus 200 that is suitable for exposing substrates, such as high-density packaging substrates, which require a shorter substrate exposure cycle time and high resolution for the exposure pattern image.

Landscapes

• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Multimedia (AREA)
• Exposure And Positioning Against Photoresist Photosensitive Materials (AREA)
• Exposure Of Semiconductors, Excluding Electron Or Ion Beam Exposure (AREA)

Priority Applications (4)

Applications Claiming Priority (1)

Publications (1)

Family

ID=96217411

Family Applications (1)

Country Status (4)

Citations (5)

Family Cites Families (7)

• 2023
  • 2023-12-26 WO PCT/JP2023/046809 patent/WO2025141733A1/ja active Pending
  • 2023-12-26 JP JP2025532617A patent/JPWO2025141733A1/ja active Pending
  • 2023-12-26 CN CN202380097397.8A patent/CN121002451A/zh active Pending
  • 2023-12-26 KR KR1020257036719A patent/KR20250168615A/ko active Pending

Patent Citations (5)

Also Published As

Similar Documents

Legal Events