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
  • 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
  • G03F9/7023—Aligning or positioning in direction perpendicular to substrate surface
  • G03F9/7026—Focusing
• • 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
  • G03F9/7049—Technique, e.g. interferometric
  • G03F9/7053—Non-optical, e.g. mechanical, capacitive, using an electron beam, acoustic or thermal waves
  • G03F9/7057—Gas flow, e.g. for focusing, leveling or gap setting

Definitions

• the present invention relates to an optical exposure apparatus, and more particularly to an optical exposure apparatus suitable for optically forming a predetermined pattern on a surface to be exposed, such as a semiconductor wafer surface.
• the optical exposure apparatus includes a means for irradiating the pattern with light, a means for directing light obtained from the pattern to the surface to be exposed so as to form an image of the pattern on the surface to be exposed, and a position to be exposed on the surface to be exposed. It includes means for moving the surface to be exposed so as to change the surface.
• the apparatus for focusing includes means for detecting a deviation of the distance between the surface to be exposed and the light directing means from a predetermined reference, and means for moving the surface to be exposed so as to compensate for the deviation.
• the displacement detection means has a gas release hole from which gas is released toward the surface to be exposed, and further includes means for detecting a change in the flow rate of the gas released from the gas release hole based on the displacement.
• the gas emission hole generally has an axis coincident with the optical axis of the light directed to the surface to be exposed.
• the gap between the surface to be exposed and the light directing means deviates from a predetermined standard.
• the surface area to be exposed must be inevitably wide. This means that the periphery of the surface to be exposed needs a large dead area that cannot be used for exposure.
• An object of the present invention is to provide an optical exposure apparatus suitable for preventing occurrence of a large waste area which can be used for exposure on a peripheral portion of a surface to be exposed.
• Another object of the present invention is to provide an optical exposure apparatus suitable for obtaining a high throughput.
• the pattern is illuminated and the light obtained from the pattern is directed onto the exposed surface such that an image of the pattern is formed on the exposed surface.
• the exposed light surface is moved so that its exposed position can be changed.
• Means are provided for detecting a deviation from a predetermined standard between the surface to be exposed and the light directing unit, and for moving the surface to be exposed so as to compensate for the deviation.
• the detection means directs a plurality of gas emission holes from which gas is emitted toward different positions on the exposed surface to the exposed surface.
• FIG. 1 is a schematic perspective view of an optical exposure apparatus showing one embodiment according to the present invention
• FIG. 2 is a schematic view of a focusing means
• FIG. 1 is a schematic perspective view of an optical exposure apparatus showing one embodiment according to the present invention
• FIG. 2 is a schematic view of a focusing means
• FIG. 1 is a schematic perspective view of an optical exposure apparatus showing one embodiment according to the present invention
• FIG. 2 is a schematic view of a focusing means
• FIG. 1 is a schematic perspective view of an optical exposure apparatus showing one embodiment according to the present invention
• FIG. 2 is a schematic view of a focusing means
• FIG. 3 is a bottom view of the lens holder 1 of FIG. 2
• FIG. 4 is a view of a front showing a procedure of exposure.
• a light source 1 such as a mercury lamp
• a condenser lens 2 is focused on a condenser lens 2 and is formed on a transparent plate 3 called a reticle or mask. Is irradiated.
• the light transmitted through the transparent plate 3 is projected onto the semiconductor wafer 5 by the projection lens 5 so that a reduced or equal-sized pattern is formed on the surface of the semiconductor wafer 4 which is the surface to be exposed.
• the semiconductor wafer 4 is held by a wafer holder 6, and the holder is supported by a moving table 7.
• the carriage 7 is supported by the carriage 8 and can be moved in the X-axis direction by the driving device 9 on the carriage.
• the carriage 8 is supported by the carriage 10, and is orthogonal to the X axis by the driving device 11 on the carriage 10.
• a moving table 13 is interposed between the moving table and the moving table.
• the light can be moved in the optical axis direction of the light directed to the wafer 4.
• the semiconductor wafer 4 moves in the X-axis direction and the
• Laser—Position measuring device that uses light 16 is a semiconductor wafer
• Exposure position moved to the exposure position that is, optical axis position *
• the computer 15 controls the driving devices 9 and 11 to compensate for the difference.
• the projection lens 4 is a lens holder.
• Holder 16 is further positioned at the lower end around the optical axis.
• 17a and 17c are shown on the X-axis as
• And 17 d are respectively arranged on the Y axis.
• Gas discharge section 17a to 17d is gas introduction chamber 18a to I8d
• Gas at pressure is released through gas introduction chambers 18a to 18d.
• Exchangers 2 1 a to 21 d are used to transfer gas from the gas introduction source 20.
• the electrical signal differs from the characteristic of the differential pressure transducer 21a to 21d.
• Adjustment circuit Select one of the outputs of 23a to 23d,
• the moving table 10 is fed back to the driving device 14 so as to move in the Z-axis direction.
• the gas is released according to the shift.
• the flow rate of the gas discharged from the hole 19 changes, and this change in the flow rate is detected by the differential pressure transducer 21a as a change in the back pressure.
• An electric signal corresponding to the back pressure change is extracted from the differential pressure converter 21a, and is output to the terminal 15) by the computer 15 via the gain adjustment circuit 23a.
• the electric signal output to this terminal is supplied to a driving device 14, which moves the semiconductor wafer 4 in the Z-axis direction so as to compensate for the back pressure change, and thus the deviation.
• the coordinate position of the optical axis of the light directed to the semiconductor wafer 4 that is, the exposure position is defined as X—
• Reference numeral 15 controls the driving devices 9 and 10 so that the semiconductor wafer 4 is moved stepwise or stepwise by one step at a time in a predetermined direction. Further, the area to be exposed next to the exposure of the exposure area at the current exposure position on the semiconductor wafer 4, that is, the coordinate position of the next exposure area is (X i).
• the computer 15 is used to measure or detect how much the surface of the next exposure area at the coordinate position (xt, y1) deviates from the predetermined reference position in the optical axis direction. Decide which of 7a to l7d to use. To this end, the amount of movement of the semiconductor wafer 4 in steps D and F to be described later is reduced as much as possible! ) From the point of improving the throughput, referring to Fig. 3, when yi ⁇ 1 and yi ⁇ -1, the gas discharge part 17 b is set,,> X1 and> -X! At this time, the gas discharge part 17 c is changed to yi ⁇ X! And yi X!
• the gas discharge part 17 d it is preferable to use the gas discharge part 17 d, and when yi> X i and 7 ⁇ xi, use the gas discharge part 17 a.
• the selection of the gas discharge units 17a to 17d here is not limited to the selection of the gain control circuits 23a to 23d.
• Computer 15 determines whether X and y are zero. to decide.
• step C If either J x or y is not zero in step C, the computer 15 moves to the coordinate position ( ⁇ ., Y.) Of the gas discharge part where the next exposure position (x t , 1) is selected. ), The driving devices 9 and Z or 11 are controlled so as to operate the semiconductor device 4 until the values match.
• the computer 15 is driven to move the semiconductor wafer 4 by XQ and y0 so that the next exposure position at the (x, y.) Coordinate position coincides with the origin (0, 0). Controls devices 9 and 11.
• Step G The computer 15 controls the driving device 14 so as to move only the next exposure area moved to the origin in the Z-axis direction. This completes focusing on the next area to be exposed.
• step E (however, if step D is required, up to step C), the exposure of the exposed area originally located at the origin may be continued.
• the gas discharge hole does not have an axis coincident with the optical axis.
• the size of the gas outlet can be reduced as desired, subject to the limitations of light passing through the optical axis.
• the conductor wafer can be selected and used so as to minimize the amount of movement of the conductor wafer in the X-axis and Y-axis directions.
• the computer 15 averages the output signals of the gain control circuits 23a to 23d, and controls the driving device 14 to perform focusing using the average value. You may do it.
• These basic concepts are based on the assumption that a shift in the optical axis direction of a region to be exposed of a semiconductor wafer coincident with the optical axis in a direction of the optical axis from a predetermined position] is a gas discharge hole 19 around the optical axis. It is assumed that it is equal to the average value of the deviation in the optical axis direction from a predetermined position of the surface portion of the semiconductor wafer facing each of a to 19 d: 3 ⁇ 4.
• One or more of the 17a to 17d may protrude from the semiconductor wafer and cannot be used for focusing.] 9 Electrical signals are excluded from averaging. An extreme difference occurs in the magnitude of the obtained electric signal between the case where the gas discharge holes protrude from the semiconductor wafer and the case where the gas discharge holes do not protrude from the semiconductor wafer. Whether or not
• the computer 15 is caused to make a judgment, and the computer 15 is made to perform averaging of only electric signals of a predetermined level or higher that are obtained when the data does not protrude.
• the computer 15 makes a determination of 16 messages as shown in Table 1 below, in order to average only the electrical signals above a predetermined level.
• L is the gain control circuit 23 a

Landscapes

• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Exposure Of Semiconductors, Excluding Electron Or Ion Beam Exposure (AREA)
• Exposure And Positioning Against Photoresist Photosensitive Materials (AREA)
• Variable Magnification In Projection-Type Copying Machines (AREA)

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Citations (2)

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• 1983
  • 1983-03-16 JP JP58042254A patent/JPS59169134A/ja active Granted
• 1984
  • 1984-03-16 WO PCT/JP1984/000107 patent/WO1987002178A1/ja unknown
  • 1984-03-16 US US06/671,218 patent/US4615614A/en not_active Expired - Lifetime

Patent Citations (2)

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