WO1999008315A1 - Procede d'exposition par balayage, graveur par projection a balayage, procede de production du graveur par projection a balayage et procede d'analyse des erreurs de synchronisation - Google Patents
Procede d'exposition par balayage, graveur par projection a balayage, procede de production du graveur par projection a balayage et procede d'analyse des erreurs de synchronisation Download PDFInfo
- Publication number
- WO1999008315A1 WO1999008315A1 PCT/JP1998/003558 JP9803558W WO9908315A1 WO 1999008315 A1 WO1999008315 A1 WO 1999008315A1 JP 9803558 W JP9803558 W JP 9803558W WO 9908315 A1 WO9908315 A1 WO 9908315A1
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- Prior art keywords
- synchronization error
- mask
- average value
- exposure
- scanning
- Prior art date
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Classifications
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- 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
- G03F7/70216—Mask projection systems
- G03F7/70358—Scanning exposure, i.e. relative movement of patterned beam and workpiece during imaging
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- 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
Definitions
- a predetermined slit region on a mask is illuminated with illumination light, and a mask and a non-exposed object such as a sensitive substrate are formed on a mask while being relatively moved in a predetermined scanning direction in synchronization with each other.
- a pattern formed on a mask or a reticle (hereinafter, collectively referred to as a reticle) is formed on a substrate such as a wafer or a glass plate (hereinafter, a sensitive substrate or An exposure apparatus that exposes light onto an object is used.
- a substrate such as a wafer or a glass plate
- An exposure apparatus that exposes light onto an object is used.
- steppers step-and-repeat type reduction projection exposure apparatuses
- step-and-scan projection exposure apparatuses are relatively large. It is being used.
- the dynamic factor of the synchronization error between the reticle and the sensitive substrate during scanning exposure is caused by the displacement (or distortion) of the pattern image transferred onto the substrate and the resolution. It is urgently necessary to analyze the effect on the deterioration of the steel.
- the analysis of the synchronization accuracy between the two objects as described above is not limited to the exposure apparatus, and may be necessary for other apparatuses.
- a first object of the present invention is to provide a scanning exposure method capable of grasping the influence or factor of the synchronization accuracy on the exposure result by measuring the synchronization accuracy when the mask and the sensitive substrate are relatively scanned. And a scanning exposure apparatus.
- a second object of the present invention is to measure a synchronization accuracy when a mask and a sensitive substrate are scanned relative to each other, so that an influence or a factor of the synchronization accuracy on an exposure result can be grasped. It is to provide a manufacturing method of.
- a third object of the present invention is to provide a synchronization error analysis method capable of quantitatively analyzing synchronization accuracy between a mask and first and second objects represented by a sensitive substrate.
- a scanning exposure method for exposing a mask to a mask includes a measurement step of measuring a physical quantity related to a position of a mask and a physical quantity related to a position of a non-exposed object during a relative movement of the mask and the non-exposed object; Based on mask and non A first calculation step of calculating a synchronization error with the exposure object; and a display step of displaying the synchronization error calculated in the first calculation step.
- a predetermined slit region on a mask is illuminated with illumination light, and a mask and a non-exposure object are synchronously moved in a predetermined scanning direction relative to each other, while a pattern formed on the mask is projected on the non-exposure object
- a scanning type exposure apparatus for exposing a mask, a first measuring apparatus for measuring a physical quantity related to a position of a mask; a second measuring apparatus for measuring a physical quantity related to a position of a non-exposed object; a mask and a non-exposed object
- a monitoring device for monitoring the measured values of the first and second measuring devices during relative movement of the first and second measuring devices; and a first calculating device for calculating a synchronization error between the mask and the non-exposure object based on a monitoring result by the monitoring device.
- a display device for displaying the synchronization error calculated by the first calculation device.
- the physical quantity related to the position means not only the position information but also a physical quantity whose position can be obtained by a simple calculation such as a speed obtained by differentiating the information or an acceleration obtained by further differentiating the speed.
- the physical quantities related to the respective positions of the mask and the non-exposure object are measured, and the synchronization error between the mask and the non-exposure object is calculated based on the measurement result. Output. Based on this synchronization error, it is possible to know the degree to which the synchronization accuracy at the time of scanning between the mask and the non-exposed object affects the exposure result.
- the synchronization error between the point at which an arbitrary point on the non-exposure object enters the slit area and the point at which it exits average value this c displaying the synchronization error by calculating case of, based on the synchronization error in a single scan, which is calculated, for each of each of a plurality of arbitrary points on the unexposed object points, each Calculate the synchronization error for each factor by calculating the average value of the synchronization error from when the point enters the slit area until it exits, and at least one of the scattering levels around the average value of the synchronization error. Is preferred.
- the synchronization error By using at least one of the average value of the synchronization error (hereinafter referred to as “moving average” as appropriate) and the degree of dispersion around the average value of the synchronization error (hereinafter referred to as “moving standard deviation” as appropriate), It is possible to analyze the synchronization accuracy when scanning with an unexposed object for each factor that gives an exposure result. That is, if the above moving average is used, the synchronization error It is possible to quantitatively evaluate to some extent the displacement of the pattern transferred onto the non-exposed object, that is, the effect on the pattern image distortion.
- the average value of the synchronization error and the degree of dispersion around the average value of the synchronization error may be displayed simultaneously or separately.
- the moving average and the moving standard deviation are displayed simultaneously or separately, by looking at the display, the above-described analysis of the synchronization accuracy by factor can be easily performed.
- the calculation of the synchronization error and the calculation of the average value of the synchronization error and the degree of dispersion around the average value of the synchronization error are preferably performed separately in the scanning direction, the non-scanning direction orthogonal to the scanning direction, and the rotation direction.
- the average value of the synchronization error or the degree of dispersion around the average value of the synchronization error may be compared with a predetermined reference value, and a warning may be issued according to the comparison result. In this way, the warning can be used to assure that the operator can recognize the faulty state of the apparatus in which an exposure failure is evident.
- the above physical quantities are detected to determine the synchronization error, and data such as the moving average and the moving standard deviation calculated based on the synchronization error are used to analyze the synchronization accuracy by factor after the exposure is completed.
- the synchronization error may be calculated by measuring the physical quantity while relatively moving the mask and the non-exposed object while the irradiation of the illumination light is stopped. In the latter case, prior to exposure, the mask and the non-exposed object are moved relative to each other in exactly the same way as during exposure, while the illumination light is stopped, and during this relative movement, the physical quantities related to the positions of the mask and the non-exposed object are calculated.
- the measurement is used to determine the synchronization error, and the moving average and moving standard deviation are calculated based on the synchronization error. Therefore, it is possible to perform a factor analysis of synchronization accuracy in advance before the actual exposure starts. As a result, it is possible to avoid a useless exposure operation in which an exposure failure occurs due to a synchronization error.
- the characteristic of the synchronization error between the mask and the non-exposed object is detected based on the average value of the synchronization error or the degree of dispersion around the average value of the synchronization error, and the movement between the mask and the non-exposed object is corrected so as to correct the characteristic. You may make it control.
- the term has almost the same meaning as the type of influence that the synchronization error, such as whether the synchronization error causes distortion of the image of the mask pattern or deterioration of the resolution of the image, on the exposure result.
- the control unit uses the data such as the moving average and moving standard deviation obtained during exposure of the non-exposed object (or the shot on the substrate) to calculate the characteristics of the synchronization error between the mask and the non-exposed object. Is detected, and the movement between the mask and the non-exposed object is controlled so as to correct the characteristic.
- the relative movement control between the mask and the non-exposure object is performed at the time of a shot after the shot based on the characteristics of the synchronization error calculated based on the measurement result at the time of the predetermined shot, When exposing an unexposed object (or the next shot on the substrate), exposure defects due to synchronization errors are less likely to occur.
- the scanning type exposure apparatus also calculates the average value of the synchronization error or the degree of dispersion around the average value of the synchronization error for all shot regions on the non-exposed object.
- Each shot may be stored, and the relative movement control between the mask and the non-exposed object may be performed at the time of exposure of each shot based on the stored data of each shot.
- the synchronous error analysis method includes: a first step of synchronously moving a first object and a second object relative to each other along a predetermined moving direction; and a physical quantity related to the position of the first object during the relative movement. And a second step of detecting a physical quantity related to the position of the second object, respectively; and a third step of detecting an average value of a synchronization error between the first object and the second object based on a result of the second step. including.
- the average value of the synchronization error the average value of the synchronization error between the first object and the second object during the time when an arbitrary point of the second object passes through the predetermined section is calculated based on the above physical quantity. Can be used.
- the first object and the first object within a time when each point passes through a predetermined section are determined based on the physical quantity.
- the method includes calculating at least one of the average value of the synchronization error with the second object and the degree of dispersion around the average value of the synchronization error. According to this, on the basis of at least one of the average value of the synchronization error between the first object and the second object and the degree of dispersion around the average value of the synchronization error during the time when the second object passes through the predetermined section, This makes it possible to quantitatively analyze the synchronization accuracy between the first object and the second object.
- a method of assembling a scanning type exposure apparatus includes: placing a first measuring device for measuring a physical quantity related to a position of a mask with respect to a mask stage on which a mask is placed; measuring a physical quantity related to a position of a sensitive substrate; A second measuring device is arranged in relation to a substrate stage on which the sensitive substrate is placed; and a mask and a measuring device based on measurement results of the first and second measuring devices obtained during the relative movement of the mask and the sensitive substrate.
- An arithmetic device for calculating the synchronization error with the sensitive substrate is connected to the first and second measuring devices; a display device for displaying the synchronization error calculated by the arithmetic device is connected to the arithmetic device.
- FIG. 1 is a diagram showing a schematic configuration of the scanning exposure apparatus according to the first embodiment.
- FIG. 2A is a schematic plan view of a wafer stage constituting the apparatus of FIG.
- FIG. 2B is a schematic plan view of a reticle stage included in the apparatus of FIG.
- FIG. 3 is a block diagram showing a configuration of a stage control system of the apparatus shown in FIG.
- FIG. 4 is a flowchart showing a main control algorithm of the microprocessor of FIG. 3 for explaining a check operation of a synchronization error between a reticle and a wafer.
- FIG. 5 is a diagram schematically showing changes in the respective positions of the reticle and the wafer when exposing a certain shot area on the wafer.
- FIG. 6 is a graph showing an example of a change in the synchronization error.
- FIG. 7A is a graph showing an example of a change in the moving average.
- FIG. 7B is a graph showing an example of the moving standard deviation.
- FIG. 8 is a block diagram illustrating a configuration of a stage control system according to the second embodiment.
- FIG. 9 is a flowchart showing a main control algorithm of the microphone port processor according to the second embodiment.
- FIG. 1 shows a schematic configuration of a scanning exposure apparatus 10 according to the first embodiment.
- This scanning exposure apparatus 10 uses an energy beam, that is, an exposure light IL to form a mask (first object),
- An illumination system 12 that illuminates the reticle R, a mask stage or reticle stage 14 that scans the reticle R in the Y-axis direction (horizontal direction in FIG. 1) and minutely drives in the XY plane, and this reticle stage 14
- It has a wafer stage 16 and a main control system 18 composed of a microphone computer or minicomputer for controlling the entire apparatus.
- the illumination system 12 includes a light source unit 20, a mirror 22, a reticle blind 24, a relay lens 26, a mirror 28, and a condenser lens 30.
- the light source section 20 is configured to include a light source such as an ultra-high pressure mercury lamp or a laser light source, and an optical integration device.
- reticle blind 24 is arranged at a position conjugate with the pattern forming surface on the lower surface of reticle R.
- Exposure light IL emitted from the light source section 20 passes through the mirror 22, the reticle blind 24, the relay lens 26, the mirror 28, and the condenser lens 30 and has uniform illuminance.
- 24 Illuminate the slit-shaped illumination area (slit area) RA (see Fig. 2B) set by 4.
- the longitudinal direction of the slit-shaped illumination area RA is set in the X direction (perpendicular to the paper surface in FIG. 1), and the relative scanning direction between the reticle R and the slit-shaped illumination area RA is the Y direction. I do.
- the reticle stage 14 holds a reticle R mounted on a reticle coarse movement stage 34 that moves along a scanning direction (Y direction) on a reticle base (not shown). And a reticle fine movement stage 36 that performs fine movement (including rotation) in the XY plane.
- the movable mirror 32 is provided on the reticle coarse movement stage 34.
- a laser reticle coarse interferometer 42 that projects a laser beam onto the movable mirror 32 and receives the reflected light to detect the position of the reticle coarse movement stage 34 in the Y direction is a movable mirror. It is provided facing 32.
- the output of the reticle coarse movement laser interferometer 42 is supplied to the main control system 18.
- Main control system 18 measures the position of reticle coarse movement stage 34 in the Y direction based on the output of reticle coarse movement laser interferometer 42.
- On the reticle fine movement stage 36 a movable mirror 38 is provided on the reticle fine movement stage 36. This moving mirror
- the first measuring device that detects the position of the reticle fine movement stage 36 by projecting a laser beam on 38 and receiving the reflected light, that is, the reticle fine movement laser interferometer
- an X-axis movable mirror 38X extending in the Y direction is fixed to the end of the reticle fine movement stage 36 in the + X direction.
- the former movable mirror 38 X is irradiated with a laser beam LRX parallel to the X axis.
- the latter movable mirror 38 y 38 y 2 is irradiated with laser beams LR L and L RR in parallel with the Y axis, respectively.
- the laser beams LR X , LR L , and L RR are supplied from the reticle fine motion laser interferometer 40 shown in FIG.
- the moving mirror (corner cube) in the Y direction which is the scanning direction 3 8 3 8
- the laser beams LR L and LR r reflected by y 2 are reflected by the reflecting mirrors 39 A and 39 B, respectively, and returned.
- the Y-axis interferometer for the reticle is a double-pass interferometer, whereby the reflected laser beam becomes parallel to the incident laser beam even when the reticle fine movement stage 36 rotates.
- reference symbol RA denotes a slit-shaped illumination area on reticle R.
- the interferometer 40 is composed of a three-axis laser interferometer. In FIG. 1, these moving mirrors are represented by reference numeral 38, and the reticle fine movement laser interferometer is represented by reference numeral 40.
- the output of the three-axis reticle fine movement laser interferometer 40 is supplied to the main control system 18.
- the main control system 18 measures the X position of the reticle fine movement stage 36 based on the output (R x ) of the interferometer using the laser beam LR x as the length measuring axis.
- the main control system 18 adjusts the Y position of the reticle fine movement stage 36 based on the average value of the outputs ( RL , RR) of the two Y-axis interferometers whose measurement axes are the laser beams LR L and LR R.
- Calculate two Y-axis interferometers The rotation angle of the reticle fine movement stage 36 in the XY plane is calculated based on the difference between the outputs of the laser beams LR L and L RR.
- the projection optical system PL is supported on a surface plate (not shown) via a first column (not shown) so that its optical axis direction is the Z-axis direction orthogonal to the XY plane.
- a second column (not shown) is provided on the first column, and a reticle base is provided on the second column.
- the wafer stage 16 is an XY stage that moves in an XY two-dimensional direction on a wafer base (not shown), a leveling stage provided on the XY stage, and placed on the leveling stage. And a Z ⁇ 0 stage for holding the wafer. In FIG. 1, the wafer stage 16 is indicated by a representative symbol 16.
- a movable mirror 46 is provided on the wafer stage 16.
- a second measuring device that projects a laser beam onto the movable mirror 46 and detects the position of the wafer stage 16 by receiving the reflected light faces the movable mirror 46.
- a wafer laser interferometer 48 faces the movable mirror 46.
- an X-axis movable mirror 46X extending in the Y direction is fixed to one end of the wafer stage 16 in the X direction
- a movable mirror 46Y of the Y-axis extending in the X direction is fixed to an end in the direction.
- the movable mirror 46 X has laser beams LW X1 and LW at an interval D along the optical path parallel to the X axis and passing through the optical axis AX of the projection optical system PL and the detection center of the alignment sensor (not shown).
- X2 is irradiated.
- the movable mirror 46Y is irradiated with two laser beams LW Y1 and LW Y2 at an interval D along an optical path parallel to the Y axis.
- the laser beams LW X1 , LWx2, L WYI and LW Y2 are supplied from the wafer laser interferometer 46 in FIG. 1, respectively.
- the wafer laser interferometer 46 has four-axis laser interference. It consists of a total. In FIG. 1, these moving mirrors are represented by reference numeral 46, and the wafer laser interferometer is represented by reference numeral 48.
- the output of the 4-axis wafer laser interferometer 48 is supplied to the main control system 18.
- the main control system 18 measures the X position of the wafer stage 16 based on the output (W X1 ) of the interferometer using the laser beam LW X1 as the measurement axis, and measures the laser beams LW Y1 and LW Y2 as the measurement axes.
- the Y position of the wafer stage 16 is measured based on the average value of the outputs (W yi , Wy 2 ) of the two Y-axis interferometers.
- the main control system 1 8 the difference between the output of the X-axis interferometer that the laser beam LW X1 and measurement axis (W X1) and the output of the interferometer laser beam LW X2 and measurement axes (W X2)
- the rotation angle of the wafer stage 16 in the XY plane is calculated based on the distance D.
- the position of the X-direction when using ⁇ Lai placement sensor (not shown), as so-called Abbe error does not occur, interferometer and the interferometer laser beam and the detection point of Araimento is that Itasu over, i.e. the laser beam LW Y2 Is controlled based on the output of the interferometer (W Y2 ).
- the main control system 18 synchronously scans the reticle coarse movement stage 34 in the + Y direction at a predetermined scanning speed V R via a reticle driving device (not shown).
- the relative speed error between the reticle coarse movement stage 34 and the wafer stage 16 is absorbed, and the relative speed and position between the reticle R and the wafer W are set to 4: 1 for fine movement control (not shown).
- the operation of the reticle fine movement stage 36 is controlled via the driving device.
- the wafer W is moved relative to the exposure area SA conjugate with the illumination area. Is scanned in the one Y direction at a speed corresponding to the reduction magnification of the projection optical system PL, and the pattern formed on the pattern formation surface of the reticle R is sequentially transferred to the shot area on the wafer W.
- the main control system 18 is provided with a memory 88 and a display device 90.
- a display device 90 for example, a CRT display or a liquid crystal display device used for a personal computer is used.
- FIG. 3 is a block diagram of the stage control system 92 of the scanning exposure apparatus 10 according to the present embodiment.
- Fig. 3 shows the microcontroller that constitutes the main control system 18 in Fig. 1. It shows various functions realized by various control programs (software) together with the processor 68 in block form. Each component may be constituted by corresponding individual hardware.
- the stage control system 92 includes a scan speed generator 51 that outputs the speed command values V and v of the wafer stage 16 according to an instruction from a main computer (not shown), and a scan speed generator 51 based on the velocity command value V w from the wafer stage speed control system 5 2 for controlling the speed of the wafer stage 1 6, the velocity command value V w 1/3 times (4 times in this case) the velocity command value V R
- the reticle coarse movement stage speed control system 54 that controls the speed of the reticle coarse movement stage 34 based on the position of the reticle, and the synchronous position that calculates the reticle synchronous position using the determinant described later based on the position of the wafer stage 44
- a reticle fine movement stage control system 56 for controlling the position (and speed) of the reticle fine movement stage 36 based on the position information which is the calculation result of the synchronous position calculation section 62; Measurement of laser interferometer 4 8 And a microprocessor 6 8 to monitor evening the measurement values of the reticle micro-moving
- the wafer stage speed control system 52 includes, for example, a subtractor that calculates a speed deviation which is a difference between the speed command value Vw and the speed of the wafer stage 16, and a speed deviation from this subtractor.
- a subtractor that calculates a speed deviation which is a difference between the speed command value Vw and the speed of the wafer stage 16, and a speed deviation from this subtractor.
- the speed of the wafer stage 16 is obtained from the differential value of the measurement value of the wafer laser interferometer 48.
- a type 1 closed loop control system including a subtractor that performs the control operation (proportional + integral) using a speed deviation from the subtractor as an operation signal (neither is shown).
- the speed of reticle coarse movement stage 34 can be obtained from the differential value of the measured value of reticle coarse movement laser interferometer 42.
- the synchronous position calculator 62 includes information on the position of the wafer stage (W X 1 , W x 2, W Y 1 , WY) obtained by integrating the output of the wafer stage speed control system 52 with the first integration circuit 64. 2), a matrix operation represented by the following equation (1) is performed, and the reticle fine movement Di 3 6, i.e. the reticle micro-moving laser interferometer 4 measured values of the three axes of 0 to measure the position of the reticle R (R x, R L, R R) target value (Rx ', RL', R R ') a Calculate.
- Information of the position of the (W X 1, WX2, WY !, WY 2) is actually wafer laser interferometer
- Equation (1) the matrix of 3 rows and 4 columns of the first term on the right side is a transform coefficient matrix, and the matrix of 3 rows and 1 column of the second term on the right side is offset.
- the reticle fine movement stage control system 56 inputs the position information calculated by the synchronous position calculation section 62 as a target position, and outputs the target position and a reticle fine movement stage 36 which is an output of a second integration circuit 76 described later.
- a subtractor 74 for calculating a position deviation, which is a difference from the position information of the reticle fine movement laser interferometer 40, and a position loop for converting the position deviation of the subtracter 74 to a target speed. Includes gain setting device 58.
- the gain setting device 58 includes a PI controller which performs a control operation (proportional + integral) using the position deviation as an operation signal, and converts a control amount calculated by the PI controller into a speed and outputs the speed.
- the reticle fine movement stage control system 56 integrates the output of the reticle fine movement stage speed control system 60, which performs the control operation with the output from the gain setting device 58 as the target speed, and the output of the reticle fine movement stage speed control system 60. And a second integration circuit 76 for converting the position to the position of the reticle fine movement stage.
- Each element in the matrix of 3 rows and 1 column of the third term on the right side of Equation (2) is an actual measurement value of the reticle fine motion laser interferometer 40.
- the reticle fine movement stage speed control system 60 is a subtractor that calculates the speed deviation that is the difference between the target speed output from the gain setting unit 58 and the speed of the reticle fine movement stage, and operates the speed deviation from this subtractor.
- the signal includes a PI controller (not shown) that performs the control operation (proportional + integral).
- the positions of the wafer stage 16 and the reticle fine movement stage 36 are directly measured by the wafer laser interferometer 48 and the reticle fine movement laser interferometer 40, and as shown in FIG. Control system 52, Reticle fine movement stage speed This is not obtained by integrating the speed of the control system 60.
- the control system in Fig. 3 is equivalent to the actual control system. From the viewpoint of improving the responsiveness of the position control of the reticle fine movement stage control system 56, the speed error between the wafer stage 16 and the reticle coarse movement stage 34 is fed forward to the reticle fine movement stage speed control system 60. You can enter it.
- the operation of fine movement stage 36 is controlled.
- the exposure area SA conjugate with the illumination area RA is The wafer W is scanned in one Y direction at a speed corresponding to the reduction magnification of the projection optical system PL, and the pattern formed on the pattern forming surface of the reticle R is sequentially exposed on the shot area on the wafer W.
- the main control system 18 moves the wafer stage 16 by a predetermined distance in the non-scanning direction (in the X direction) to perform a stepping operation to the exposure start position of the next shot. After that, scanning exposure is performed, and exposure is performed in this manner by the step-and-scan method.
- the microprocessor 6 8 the measurement value of Wehare one The interferometer 4 8 (W X 1, W x2, W Y 1, W Y 2) and retinyl Kurureza interferometer 4 0 measurements (R X , R L , RR) are simultaneously captured at a predetermined sampling interval and sequentially stored in the memory 88 (step 100 in FIG. 4). In this way, the microprocessor 68 monitors the position of the reticle R and the position of the wafer W.
- the respective positions of the reticle R and the wafer W change as schematically shown in Fig. 5.
- FIG. 5 there is a point P 1 at the center of the exposure area SA at time t 1, which is the start of exposure, and thereafter, as time t 2, t 3,..., Tn,.
- Points P 2, P 3,..., P n,... move to the center of the area.
- the microprocessor 68 stores the measured value of the above-mentioned laser interferometer 48 and the measured value of the reticle laser interferometer 40 from time tl.
- the microprocessor 68 uses the data (W X1 , W X2 , W YI W Y2 , R X , R or RR) stored at the same time in the memory 88 to obtain the above equation (2).
- synchronization error AR X, ⁇ R L calculates the AR R.
- the calculation of the synchronization error is performed for each data at each sampling.
- a graph showing a change in the synchronization error as shown in FIG. 6 in each direction of, for example, X, ⁇ , ⁇ is obtained by one-shot exposure.
- the horizontal axis is the time or the ⁇ axis of the shot coordinate system, and the synchronization error is shown as the vertical axis. Note that the graph of the change in the synchronization error as described above is actually obtained for all the shots sampled.
- the microprocessor 68 uses the following equations (4) and (5) to move an arbitrary point Pn on the wafer W into the illumination area RA as a slit area, that is, into the exposure area SA conjugate to this. And the standard deviation as the degree of dispersion around the average of the synchronization error (hereinafter referred to as “moving standard deviation” as appropriate) (Step 104 of FIG. 4).
- the number of data acquisitions from when the point Pn enters the exposure area SA to when it leaves the exposure area SA that is, data is extracted with a slit width (width in the scanning direction of the exposure area SA) centered on the nth data
- the number of data is m times when n + (ml) / 2 ⁇
- (E ⁇ ) n indicates a moving average in the XY ⁇ direction.
- ⁇ (ErrX) ⁇ > ⁇ (ErrY) n ⁇ ( ⁇ r ⁇ ) ⁇ indicates the moving standard deviation in the X ⁇ direction.
- the microprocessor 68 stores the calculation results in the X, ⁇ , and ⁇ directions as shown in the graphs of FIGS. 7A and 7B in the memory 88.
- Step 106 This judgment is performed by setting a predetermined threshold value for each of the moving average and the moving standard deviation in the X, Y, and S directions, and calculating the moving average and the moving standard deviation in the X, ⁇ , and ⁇ directions. This is done by comparing with
- the abnormalities are displayed on the display screen of the display device 90 and a warning is issued (step 1 08 in FIG. 4). .
- a warning sound may be emitted together with this warning display. It is desirable that this warning be displayed so that at least the moving average or the moving standard deviation is abnormal.
- the information it is even more desirable that the information be such that it is possible to identify which of the X, ⁇ , and ⁇ directions. In this way, the operator can determine at a glance the type of the abnormality.
- the microprocessor 68 calculates the above calculation result, that is, X as shown in FIGS. 7 ⁇ and 7 7.
- a graph of the moving average and moving standard deviation in the 0, 0, and 0 directions is displayed on the display screen of the display device 90 (step 110 in FIG. 4).
- the above six types of graphs may be displayed simultaneously by dividing the display screen or by switching the screen according to the instruction of the operation and displaying one or more types sequentially You may do it.
- the operator can easily grasp the resolution (resolution) of the pattern image transferred onto the wafer W based on the moving standard deviation graph displayed on the display screen. As a result, it is possible to quantitatively determine, to some extent, the effect of the synchronization error between the reticle R and the wafer W on the degradation of the image resolution. In this sense, the above-mentioned warning display need not always be performed.
- a graph of a change in synchronization error as shown in FIG. 6 may be displayed on the display screen.
- the range in which the synchronization error is monitored is divided into a plurality of, for example, 10, and the frequency distribution of the synchronization error of the X, ⁇ , and ⁇ components calculated in each section is displayed on the display screen. Is also good.
- Such a display makes it possible to simultaneously and quantitatively discriminate between the positional deviation, that is, the distortion of the pattern image transferred onto the wafer W, and the degradation of the image resolution.
- the monitoring of the interferometer measurement value in step 100 in FIG. 4 is performed during the actual step-and-scan exposure as described above. However, before the exposure, the irradiation of the reticle R with the exposure light on the reticle R is stopped, and the movement of the reticle R and the wafer W is performed in the same manner as in the above-described exposure. Monitoring of the total measured value may be performed. In this way, it is possible to evaluate the state of the apparatus relating to stage control before an exposure failure actually occurs. As a result, the exposure can be stopped when there is a possibility that the image distortion and the resolution may be unacceptable due to the specifications of the exposure device at that time.
- the scanning exposure apparatus 10 After or before the exposure, the synchronization accuracy at the time of scanning between the reticle R and the wafer W can be analyzed for each factor giving the exposure result.
- the overall configuration of the scanning exposure apparatus according to the second embodiment is substantially the same as that of the above-described first embodiment, and the configuration of the stage control system is slightly different.
- the control algorithm of the microprocessor in the stage control system differs accordingly.
- the description will be made focusing on such differences, and the same reference numerals will be used for the same or equivalent components as those in the first embodiment described above, and the description thereof will be omitted or simplified.
- FIG. 8 shows the configuration of a stage control system 192 according to the second embodiment.
- the stage control system 192 has a correction table 94 composed of random access memory (RAM) attached to the microprocessor 68.
- the microprocessor 68 has an update function of the correction table 94 and a correction function. A function of inputting the data of the table 94 to the reticle fine movement stage control system 56 via the subtractor 96. Only this point is different from the first embodiment.
- FIG. 9 is a flowchart illustrating a main control algorithm of the microprocessor 68 in the main control system 18 according to the second embodiment. The operation during scanning exposure will be described below along this flowchart.
- the reticle stage 14 and the wafer stage 16 Prior to exposure, the reticle stage 14 and the wafer stage 16 have been moved to the first shot scanning start position.
- step 200 scanning exposure for a shot to be exposed, that is, a first shot is started. That is, as described above, the relative scan between the reticle R and the wafer W is started, and a command is given to an exposure controller (not shown) to start the irradiation of the illumination light from the exposure light source.
- step 202 the measurement values of the reticle fine movement laser interferometer 40 and the wafer laser interferometer 48 are monitored, that is, read and stored in the memory 88 as in step 100 of FIG. 4 described above. .
- step 204 similarly to step 102 in FIG. 4 described above, the data fetched into the memory 88 is used to determine the X, ⁇ , and ⁇ directions. The synchronization error is calculated, and the result is stored in the memory 88.
- step 206 a moving average is calculated in the X, ⁇ , and ⁇ directions using the calculated synchronization error data. Then, in the next step 208, it is determined whether or not the exposure of the shot has been completed.
- steps 202 to 206 are repeated.
- a command is given to an exposure controller (not shown) to stop the irradiation of the illumination light from the exposure light source. .
- the shutter in the light source unit 20 is closed.
- step 212 the contents of the correction table 94 are updated, and the updated data is input as a correction value to the reticle fine movement stage 56 via the subtractor 96 (see FIG. 8).
- the internal data of the correction table 94 is based on the moving average data in the X, ⁇ , and 0 directions during the first shot exposure (see FIG. 7 ⁇ ). This data is calculated in the above step 206 and stored in the memory 88.
- next step 214 it is determined whether or not all shots have been exposed. If this determination is denied, the flow shifts to step 216 to move the scanning start position of the next shot, the reticle stage 14 and the wafer stage 16. In the case of so-called alternate scanning, the reticle stage does not need to be moved. Thereafter, the process returns to step 200 to start scanning exposure for the next shot. After that, the processing and judgment of the above step 202 and thereafter are repeated.
- the second shot the contents of the correction table 9 4, i.e. X upon exposure of the first shot Bok, Y, 0-direction moving average of de Isseki of, Sapo error (AR x, ⁇ R L, ⁇ RR) to correct Added as a value.
- the reticle fine movement stage control system 56 controls the X and 6 of the reticle fine movement stage 36.
- the position is accurately controlled to the target position calculated by the synchronous position calculator 62. That is, it is a harm that the moving average calculated in step 208 becomes zero.
- the difference in the position of the first shot and the second shot on the wafer causes a different behavior of the wafer stage 16, that is, a different movement. Also retic When the moving directions of the stage 14 are opposite, the movement of the stage is often different, so that the moving average is not actually zero.
- the update of the correction table 94 in the step 212 at the time when the exposure of the second shot and subsequent shots is completed is calculated in the step 206 of the exposure of the shot. That is, the moving average data in the X, Y and 0 directions stored in the memory 88 is added to the data in the correction table 94. As a result, the synchronization error (residual error) is gradually corrected during the exposure after the next shot.
- step 2 14 If the second shot exposure is completed and the determination in step 2 14 is denied, the process moves to step 2 16, and then the third shot, fourth shot, fifth shot, « ⁇ Exposure is performed by the scanning method. Then, the synchronization error is sequentially corrected using the data of the correction table 94 updated for each exposure of each shot. As a result, good exposure is performed on all shot areas while suppressing the displacement of the pattern image and the deterioration of the resolution.
- the stage control system 1992 detects the characteristic of the synchronization error between the reticle R and the wafer W based on the operation result of the microprocessor 68.
- a control system is configured to control the movement between the reticle R and the wafer W so as to correct this characteristic.
- the synchronization error during the scanning exposure in the next shot can be corrected using the moving average data obtained during the scanning exposure of a certain shot.
- the wafer W it becomes possible to expose a good reticle pattern whose displacement is mainly suppressed.
- the case where the synchronization error during the scanning exposure of the next shot is corrected using the moving average data obtained during the scanning exposure of a certain shot.
- the present invention is not limited thereto, and the synchronization error during the scanning exposure of the next shot may be corrected using the data of the moving standard deviation obtained during the scanning exposure of a certain shot. In such a case, it is possible to expose a good reticle pattern in which all of the shots on the wafer are mainly prevented from deteriorating in resolution. Or moving average and The synchronization error during the scanning exposure of the next shot may be corrected using the data of the moving standard deviation.
- the case where the synchronization error during the scanning exposure of the next shot is corrected using the moving average data obtained during the scanning exposure of a certain shot.
- the data area in the correction table has a data area corresponding to each shot, after the exposure of all shots is completed, the data in the correction table obtained at that time is used to expose the next wafer.
- a synchronization error between the reticle R and the wafer W at the time of exposure of each shot area may be corrected.
- the moving average is calculated using the data of the synchronization error.
- the synchronization error and the moving average may be collectively obtained after the exposure of one shot. That is, the processing of step 204 and step 206 may be collectively executed between step 208 and step 210 of the flowchart of FIG.
- the present invention is applied to the step-and-scan type projection exposure apparatus.
- the scope of the present invention is not limited to this.
- the present invention can be widely applied to other scanning exposure apparatuses, for example, so-called aligner and liquid crystal scanning exposure apparatuses of the same size, and to exposure apparatuses for manufacturing thin-film magnetic heads.
- the magnification of the projection optical system may be not only a reduction system but also any one of an equal magnification and an enlargement system.
- the present invention is also applicable to a projection exposure apparatus using a charged particle beam or X-ray.
- the synchronization error analysis method according to the present invention is not limited to an exposure apparatus, and may be any apparatus that requires a first object and a second object to be synchronized and relatively moved along a predetermined movement direction. It can be suitably applied.
- An exposure apparatus that measures and displays a synchronization error between a mask and a wafer or an exposure apparatus that measures a synchronization error between a mask and a wafer and feeds back to a drive control circuit of a reticle moving stage is described in this embodiment. It is assembled by electrically, mechanically or chemically connecting many components. Specifically, an illumination optical system composed of multiple lenses and a projection optical system are incorporated in the exposure apparatus main body to perform optical adjustment, and a reticle stage and a wafer stage composed of many mechanical parts are exposed.
- the exposure apparatus of the present embodiment can be manufactured by attaching wires and pipes to the main body of the apparatus and performing overall adjustment (electrical adjustment, operation check, etc.). It is desirable that the exposure apparatus be manufactured in a clean room where the temperature, cleanliness, etc. are controlled.
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Exposure And Positioning Against Photoresist Photosensitive Materials (AREA)
- Exposure Of Semiconductors, Excluding Electron Or Ion Beam Exposure (AREA)
Description
Claims
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AU85622/98A AU8562298A (en) | 1997-08-11 | 1998-08-11 | Scanning exposure method, scanning aligner, method of manufacturing the scanningaligner, and synchronization error analysing method |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP9/228837 | 1997-08-11 | ||
JP9228837A JPH1167655A (ja) | 1997-08-11 | 1997-08-11 | 走査型露光装置及び同期誤差解析方法 |
Publications (1)
Publication Number | Publication Date |
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WO1999008315A1 true WO1999008315A1 (fr) | 1999-02-18 |
Family
ID=16882644
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP1998/003558 WO1999008315A1 (fr) | 1997-08-11 | 1998-08-11 | Procede d'exposition par balayage, graveur par projection a balayage, procede de production du graveur par projection a balayage et procede d'analyse des erreurs de synchronisation |
Country Status (3)
Country | Link |
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JP (1) | JPH1167655A (ja) |
AU (1) | AU8562298A (ja) |
WO (1) | WO1999008315A1 (ja) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1879217A1 (en) * | 2005-03-18 | 2008-01-16 | Nikon Corporation | Exposure method, exposure apparatus, device manufacturing method and exposure apparatus evaluating method |
US7692764B2 (en) | 2004-08-30 | 2010-04-06 | Nikon Corporation | Exposure apparatus, operation decision method, substrate processing system, maintenance management method, and device manufacturing method |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP5002704B2 (ja) * | 1999-11-30 | 2012-08-15 | キヤノン株式会社 | 投影露光装置、投影露光方法、及び半導体装置の製造方法 |
JP2001223157A (ja) * | 1999-11-30 | 2001-08-17 | Canon Inc | 投影露光装置、投影露光方法、及び半導体装置の製造方法 |
JP2001166456A (ja) | 1999-12-07 | 2001-06-22 | Mitsubishi Electric Corp | ウェハパターン誤差の要因解析方法および写真製版用マスクの製造装置 |
WO2005008752A1 (ja) * | 2003-07-23 | 2005-01-27 | Nikon Corporation | 露光装置、露光方法及びデバイス製造方法 |
NL2005719A (en) | 2009-12-18 | 2011-06-21 | Asml Netherlands Bv | Method of measuring properties of dynamic positioning errors in a lithographic apparatus, data processing apparatus, and computer program product. |
Citations (5)
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JPH0969481A (ja) * | 1995-08-31 | 1997-03-11 | Canon Inc | 同期スキャン制御装置 |
JPH0974059A (ja) * | 1995-09-04 | 1997-03-18 | Canon Inc | 精密制御装置 |
JPH09115799A (ja) * | 1995-10-16 | 1997-05-02 | Nikon Corp | 走査型露光装置 |
JPH09186075A (ja) * | 1996-01-05 | 1997-07-15 | Canon Inc | 走査型露光装置 |
JPH09199399A (ja) * | 1996-01-12 | 1997-07-31 | Canon Inc | 同期制御装置および方法 |
-
1997
- 1997-08-11 JP JP9228837A patent/JPH1167655A/ja not_active Withdrawn
-
1998
- 1998-08-11 AU AU85622/98A patent/AU8562298A/en not_active Abandoned
- 1998-08-11 WO PCT/JP1998/003558 patent/WO1999008315A1/ja active Application Filing
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
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JPH0969481A (ja) * | 1995-08-31 | 1997-03-11 | Canon Inc | 同期スキャン制御装置 |
JPH0974059A (ja) * | 1995-09-04 | 1997-03-18 | Canon Inc | 精密制御装置 |
JPH09115799A (ja) * | 1995-10-16 | 1997-05-02 | Nikon Corp | 走査型露光装置 |
JPH09186075A (ja) * | 1996-01-05 | 1997-07-15 | Canon Inc | 走査型露光装置 |
JPH09199399A (ja) * | 1996-01-12 | 1997-07-31 | Canon Inc | 同期制御装置および方法 |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7692764B2 (en) | 2004-08-30 | 2010-04-06 | Nikon Corporation | Exposure apparatus, operation decision method, substrate processing system, maintenance management method, and device manufacturing method |
EP1879217A1 (en) * | 2005-03-18 | 2008-01-16 | Nikon Corporation | Exposure method, exposure apparatus, device manufacturing method and exposure apparatus evaluating method |
EP1879217A4 (en) * | 2005-03-18 | 2010-06-09 | Nikon Corp | EXPOSURE METHOD, EXPOSURE APPARATUS, DEVICE MANUFACTURING METHOD, AND EXPOSURE APPARATUS EVALUATION METHOD |
US8638422B2 (en) | 2005-03-18 | 2014-01-28 | Nikon Corporation | Exposure method, exposure apparatus, method for producing device, and method for evaluating exposure apparatus |
Also Published As
Publication number | Publication date |
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AU8562298A (en) | 1999-03-01 |
JPH1167655A (ja) | 1999-03-09 |
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