JP2016032003A - Lithography apparatus, irradiation method, and method of manufacturing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the loss of stitching accuracy of pattern, occurring due to slow timing of measurement of a mark performed during exposure.SOLUTION: A lithography apparatus 1 for forming a pattern by irradiating a substrate 4 with a beam has a measuring instrument 9 for measuring the position of a mark 33 formed on the substrate 4, a prediction unit 20 for predicting the positional information of the mark at a predetermined timing, by using the measurement results measured by the measuring instrument 9 at different timings, and correction units 20, 21, 22, 23 for correcting the irradiation position of the beam for the substrate 4, based on the positional information predicted by the prediction unit 20.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a lithographic apparatus that irradiates a substrate with a beam, an irradiation method, and a device manufacturing method.

  In a lithography process for manufacturing a semiconductor device, an n-th layer pattern is superimposed on a (n-1) -th layer pattern, or two adjacent layers exposed at different timings among the n-th layer patterns. It is necessary to connect the pattern of the area with high accuracy. Therefore, the exposure apparatus detects a plurality of alignment marks (hereinafter referred to as alignment marks) formed on the substrate, and determines the position of the pattern of the new layer based on the position of the alignment mark. However, when the amount of heat input to the substrate is large, the thermal distortion of the substrate proceeds during the formation of a single-layer pattern, and there is a problem that the overlay accuracy and the joining accuracy are likely to be lowered.

  Therefore, Patent Document 1 discloses a technique for calculating a map in which the distortion of the substrate generated up to the timing is estimated using the drawing pattern and the energy applied to the substrate up to an arbitrary timing. Patent Document 2 discloses a technique for measuring the position of an alignment mark during drawing of a single layer pattern and correcting the irradiation position of the electron beam on the substrate based on the measurement result.

JP 2004-31030 A US Pat. No. 7,897,942

  However, the method described in Patent Document 1 determines the substrate thickness, the material of each layer on the substrate, the influence of the internal stress difference generated between the materials at each location on the substrate, and the like when determining the distortion of the substrate by a computer. Not considered. Therefore, there is a concern about the difference between the thermal strain obtained by calculation and the actual thermal strain.

  In the method described in Patent Document 2, if the measurement timing is late, thermal distortion may advance excessively until measurement is performed again. As a result, there is a possibility that the pattern between the area to be drawn next and the drawn area adjacent to the area will be poorly linked.

  Accordingly, the present invention has been made in view of the above problems, and lithography capable of reducing a decrease in pattern overlay accuracy or stitching accuracy caused by a slow timing of mark measurement performed during drawing. An object is to provide an apparatus and an irradiation method.

  The lithographic apparatus according to the present invention is a lithographic apparatus that forms a pattern by irradiating a beam toward a substrate, and a measuring instrument that measures the position of a mark formed on the substrate and a timing that differs depending on the measuring instrument. A prediction unit that predicts the position information of the mark at a predetermined timing using the measurement result measured in step (b), and a correction that corrects the irradiation position of the beam on the substrate based on the position information predicted by the prediction unit. Part.

  It is possible to reduce a decrease in pattern overlay accuracy or stitching accuracy caused by a delay in the timing of mark measurement performed during exposure.

The figure of the drawing apparatus of an embodiment. Explanatory drawing of the state during drawing and an alignment mark. The flowchart regarding the correction method of a thermal distortion. The flowchart regarding the determination process of a predicted value. The figure which shows the example of a prediction function (increase function). The figure which shows the example of a prediction function (decrease function). A relationship table between the prediction function and the correction amount.

  The lithographic apparatus of the present invention uses a beam focused on a substrate (including light beams such as KrF light and EUV light, and charged particle beams such as electron beams and ion beams) to form a desired latent image pattern (on the substrate). Pattern). In the following embodiments, a drawing apparatus that draws a pattern using an electron beam as a beam will be described as an example.

[First Embodiment]
(Device configuration)
FIG. 1 is a configuration diagram of a drawing apparatus 1 which is an example of a lithography apparatus. An electron beam emitted from the electron source 2 is irradiated onto the surface of the wafer (substrate) 4 through the optical system 3. The optical system 3 has an electron lens system 3a for imaging an electron beam and a deflector 3b for deflecting the electron beam. The control unit 21 switches ON / OFF of the electron source 2 and adjusts the focusing position and deflection amount of the electron beam by controlling the optical system 3.

  The stage 5 has a Y stage 5a, an X stage 5b mounted on the Y stage, and a Z stage (not shown). A wafer chuck (not shown) on the stage 5 holds the wafer (substrate) 4. The control unit 22 moves the stage 5 in the X-axis direction, the Y stage 5a in the Y-axis direction, and the Z stage (not shown) in the Z-axis direction. Note that the configuration of the stage 5 is not limited to the present embodiment as long as the configuration is movable in the X, Y, and Z axis directions.

  A reference plate 6 on which reference marks are formed, a movable mirror 7 for measuring the position of the stage 5 in the X-axis direction, and the wafer 4 are on the X stage 5b. The reference mark is used to measure a base line (a distance between optical axes between an alignment sensor 9 and an optical system 3 described later, or a distance between optical axes between a correction sensor 10 and an optical system 3 described later).

  The interferometer 8 divides the laser beam into measurement light and reference light, enters the measurement light into the X-axis movable mirror 7, and the reference light is provided inside the interferometer 8 (not shown). Is incident on. The light reflected from each mirror is caused to interfere, and the detection unit 23 detects the intensity of the interference light. Thus, the position of the X-axis movable mirror 7 with respect to the reference mirror, that is, the position of the stage 5 in the X-axis direction is detected. Using a Y-axis moving mirror (not shown), the position of the stage 5 in the Y-axis direction is detected in the same manner. The detection system 23 sends a measurement value to the main control unit 20, and the control unit 22 controls the position of the stage 5 based on the measurement value.

  The alignment sensor 9 irradiates a plurality of alignment marks 34 (shown in FIG. 2B) formed on the wafer 4 and the reference plate 6 with light so that the alignment marks and the reference marks on the reference plate 6 Detect position. A correction sensor (measuring instrument) 10 (hereinafter referred to as sensor 10) measures the positions of a plurality of marks 33 (shown in FIG. 2B) formed on the wafer 4. Since the sensor 10 performs measurement even during pattern drawing on the wafer 4, it is preferable that the sensor 10 be small as in the vicinity of the column 13. Further, a plurality of sensors 10 are preferably arranged in order to measure the position of the mark 33 more frequently than the alignment sensor 9. The column 13, the alignment sensor 9, and the sensor 10 are not necessarily arranged on a straight line as shown in FIG.

  The light that the alignment sensor 9 or sensor 10 makes incident on the wafer 4 is preferably in a wavelength band where the resist is not exposed. For example, light having a wavelength of 400 nm or more, more preferably light having a wavelength band of 450 nm to 800 nm. Further, in order to reduce a measurement error caused by the process of the wafer 4, light having a plurality of wavelengths is preferably used instead of light having a single wavelength.

  The alignment sensor 9 forms an image of reflected light from the alignment mark 34 and the sensor 10 forms an image of reflected light from the mark 33 on a light receiving sensor (not shown) such as a TDI (Time Delay Integration) sensor included in each sensor. By doing so, images of various marks are detected. The controller 24 obtains the position of the alignment mark 34 by processing the image signal of the alignment mark 34 imaged on the light receiving sensor of the alignment sensor 9. Similarly, the control unit 24 obtains the position of the mark 33 by processing the image signal of the mark 33 imaged on the light receiving sensor of the sensor 10.

  A focus sensor (not shown) measures the height of the wafer 4 in the Z-axis direction. The focus sensor is preferably a sensor that can be used in a vacuum, such as an optical sensor or a capacitance sensor. In the vacuum chamber 12, irradiation-related members and measurement equipment such as the electron source 2, the optical system 3, the stage 5, the interferometer 8, the alignment sensor 9, the sensor 10, and the focus sensor are arranged. A vacuum pump (not shown) evacuates the vacuum chamber 12 to a vacuum.

  The main control unit (prediction unit) 20 includes a control unit 21 that controls the electron source 2 and the optical system 3, a control unit 22 that controls driving of the stage 5, a detection unit 23 that detects the measurement result of the interferometer 8, and an alignment sensor. 9 and a control unit 24 that controls the sensor 10 and a memory 25.

  A CPU held in the main control unit 20 executes a program stored in the memory 25. When the program is executed, the control unit 21, the control unit 22, the detection unit 23, and the control unit 24 are controlled. The main control unit 20 controls the electron beam irradiation position (beam irradiation position on the substrate) on the wafer 4 based on the drawing data stored in the memory 25 to form a pattern on the wafer 4. Further, the main control unit 20 stores various measurement values in the memory 25, and executes calculations based on these measurement values.

  The irradiation position of the electron beam on the wafer 4 is controlled by the main control unit 20, the control unit 21, and the control unit 22, which are correction units in the present embodiment. The control unit 21 changes the deflection amount by the deflector 3b, the main control unit 20 rewrites the drawing pattern data, or the control unit 22 changes the position of the stage 5. As long as each function is not impaired, the control unit 20, the control unit 22, the detection unit 23, and the control unit 24 may be arranged independently as shown in FIG. You may arrange | position integrally on a board | substrate. Further, the memory 25 as a storage unit may also be arranged on the circuit board.

  The memory 25 has a processing content program shown in the flowcharts of FIGS. 3 and 4 to be described later, drawing pattern data, and allowable values for pattern joining. Further, the measurement values of the alignment mark 34 and the mark 33 are sequentially stored in the memory 25 as the program is executed.

  Although FIG. 1 shows a drawing apparatus that irradiates the wafer 4 with one electron beam, a form in which a plurality of electron beams are irradiated from one column 13 having the electron source 2 and the optical system 3 may be used. . By drawing with a plurality of electron beams, the throughput can be improved. The number of columns 13, the number of alignment sensors 9, and the number of sensors 10 can be changed as appropriate.

(Mark position measurement)
Next, a method for measuring the position of the mark 33 by the sensor 10 will be described with reference to FIG. FIG. 2A is a view of the wafer 4 viewed from the + Z direction. The drawing apparatus 1 in this description has two columns 13 and two sensors 10 per column 13.

  Each column 13 is drawn while being irradiated with an electron beam while the wafer 4 is moving in the X-axis direction (solid line portion). When the wafer 4 is moving in the X-axis direction and there is no area to be drawn with an electron beam, or when moving in the Y-axis direction, no electron beam is irradiated (broken line portion). The slit 30 which is an electron beam irradiation port is at the center position of the column 13.

  FIG. 2B is an enlarged view of a partial region of the wafer 4. On the wafer 4, a plurality of shot areas 31, which are pattern drawing areas, are arranged side by side. The shot area 31 corresponds to one or a plurality of chip areas to be formed. Each shot area 31 is delimited by a scribe line 32 having a predetermined width. The alignment mark 34 and the mark 33 are arranged on the scribe line.

  When the wafer 4 moves, the sensor detects the position of the mark 33 when the mark 33 enters the measurement area of the sensor 10. Depending on the type of the sensor 10 and the type of the mark 33, the position of the mark 33 can be measured even while the wafer 4 is moving. By having the four sensors 10, a plurality of marks 33 can be detected simultaneously. It is also possible to measure the position of the same mark 33 at different timings. You may serve as the alignment mark 34 and the mark 33. FIG. The different timing means before and after the electron beam is irradiated to any region on the wafer 4.

(Drawing position correction method)
FIG. 3 is a flowchart showing the contents of the drawing position correction process according to the present embodiment. The start timing of this program is after the end of baseline measurement. In S <b> 10, the alignment sensor 9 measures the position of the alignment mark 34. Then, the deviation of the actual alignment mark position from the expected alignment mark 34 position is obtained.

  In S20, the main control unit 20 calculates shift (movement), mag (magnification), rotation (rotation), and base formation for the arrangement of the shot areas 31 on the wafer 4, and the rule of the lattice arrangement of the shot areas 31 is calculated. Determine sex. In S30, the main control unit 20 obtains a correction coefficient from the lattice arrangement and the base line determined in S20, and aligns the electron beam and the wafer 4 based on the correction coefficient. The main control unit 20 stores the correction coefficient obtained here in the memory 25.

  In S40, the sensor 10 measures the position of the mark 33 before drawing with an electron beam. The position measurement value of the mark 33 is stored in the memory 25.

  The number of marks 33 to be measured need not be the same as that of the alignment marks 34. For example, the sensor 10 may measure a larger number of marks 33 than the number of marks 34 measured by the alignment sensor 9. Thereby, it becomes possible to correct | amend the thermal distortion of the board | substrate resulting from the drawing heat in a subsequent drawing process with high precision. Alternatively, when the sensor 10 measures a smaller number of marks 33 than the alignment sensor 9, it is possible to suppress an increase in data processing load and measurement time for position correction in the main control unit 20.

  In S <b> 50, pattern drawing is started by the control unit 21, the control unit 22, the detection unit 23, and the control unit 24 that have received an instruction from the main control unit 20. In S60, drawing is performed according to a predetermined drawing pattern. During drawing, the sensor 10 measures the position of the mark 33 at the timing when the measurement area 35 passes the mark 33. Alternatively, the irradiation of the electron beam is temporarily interrupted during the drawing, and the position of the sensor 10 mark 33 is measured after the control unit 22 moves the wafer 4. From the amount of change in the position of the mark 33 measured in S40 and the position of the mark 33 measured in S60, the main controller 20 determines the local and overall wafer 4 caused by the influence of the heat of irradiation by the electron beam. The amount of deformation can be determined. In addition, since the same mark 33 is repeatedly measured at different timings, local changes in the amount of deformation can also be seen. In order to compare with the position of the mark 33 measured in S60, it is preferable that the mark 33 to be measured in S40 is all the marks measured again in S60.

  In S70, it is determined whether or not all drawing has been completed. If the main control unit 20 determines that drawing is complete (YES), the program ends. On the other hand, if it is determined that the drawing is not finished (NO), the process proceeds to step S80.

  In S80, the main control unit 20 calculates (predicts) the position information of the mark 33 at a correctable timing (predetermined timing) using the measurement results of the position of the mark 33 measured at different timings. The position information is the predicted position of the mark 33 at the correctable timing or the predicted deviation amount from the initial position of the mark 33 at the correctable timing. Based on the predicted deviation amount of the mark 33, the deformation amount of the wafer 4 at the correctable timing can be determined.

  Here, the correctable timing is a timing at which it is easy to adjust the position of the wafer 4 and the stage 5 using the position of the stage 5 or the deflector 3b. For example, the slit 30 moves from a position where drawing for one line in the X-axis direction is finished to a position where drawing on the next line is started. As a result, it becomes easy to ensure the pattern joining accuracy between the next line to be drawn and the drawn line adjacent to the line.

  Alternatively, it may be the timing when the pattern for one line is being drawn in the X-axis direction and the slit 30 is positioned on the scribe line 32. Even when the influence of the thermal strain is locally different on the wafer 4, it becomes possible to perform correction locally, and it is possible to reduce unevenness in pattern joining accuracy.

  In S90, based on the amount of change in the position of the mark 33 measured in S40 and the amount of change in the position of the mark 33 measured in S60 (time change in the position of the mark obtained from the measurement result), the predicted deviation amount generated at the correctable timing is calculated. Ask. The difference between the predicted deviation amount and the latest measurement result is compared with the desired stitching tolerance. Steps S80 and S90 will be described in detail later.

  From the comparison result obtained in S90, in S100, the control unit 20 determines whether or not it is necessary to perform correction at the next correctable timing. If it is determined that correction is not necessary (NO), drawing is continued. If it is determined that correction is necessary (YES), the correction amount is determined using the comparison result in S90, and the relative position between the wafer 4 and the electron beam is corrected (S110). After the correction in S110, the process returns to S60 again, and the drawing and the measurement of the mark 33 are continued until the drawing is completed.

  FIG. 4 is a flowchart regarding the calculation of the predicted deviation amount in S80. First, in S801, the main control unit 20 creates a prediction function f (t) indicating the amount of deviation from the initial position from the time change of the position of the mark 33 measured a plurality of times during drawing. The prediction function f (t) is obtained by performing statistical processing such as polynomial approximation on the time history of the measurement value. Subsequently, the main control unit 20 calculates a tendency of increase or decrease of the deviation amount by differentiating the prediction function f (t) (S802). The predicted deviation amount from the initial position of the mark 33 at the next correctable timing is calculated (S803).

  The steps from S80 to S100 in FIG. 3 will be described using the specific examples of FIGS. FIG. 5A is a graph showing the relationship between the time of a certain mark 33 and the amount of positional deviation in the X-axis direction, and is a prediction function f (t) created based on actual measurement values. The amount of misalignment tends to increase with the passage of time, indicating a state where the influence of thermal distortion of the wafer 4 is increasing. FIG. 5B shows a part of the prediction function f (t), and is a diagram for explaining the correction amount calculated in S803 and the correction amount required in S90.

Each plot in FIG. 5B shows a change over time in the amount of deviation of the position of the same mark 33 measured a plurality of times. Time t ₁ to the timing the end of the most recent _measurement, and the time t ₂ correctable timing the drawing position. The main control unit 20, the position of the mark 33 at time _{t 2, the} obtained from the prediction function f (t). With respect to the position of the mark 33 measured at time t _1, the tolerance which can be joined together, the allowable range of the deviation amount at the time t ₂ (shaded portion in FIG. 5 (b)) is set. The allowable range depends on the drawing pattern and the required device performance. For example, the value of the allowable range is 10 nm or less, more preferably 4 nm or less.

The main control unit 20, the difference between the predicted deviation amount of the mark 33 at time t _2, the last measured value measured at time t ₁ and (most recent measurement results), based on whether or not exceeding the allowable value, It is determined whether correction is necessary (S100). As shown in FIG. 5 (b), when the difference between the predicted deviation amount of the mark 33 at time t _2, the the most recent measurement value measured by the time t ₁ is outside the allowable range, the main control unit correction amount To decide. The main control unit 20, the control unit 21, the control unit 22, and the control unit 24 are set so that the difference between the value obtained by applying the correction amount to the predicted deviation amount and the latest measurement result by the sensor 10 is within the allowable range. The irradiation position of the electron beam on the wafer 4 is corrected. Accordingly, the deviation amount of the position of the time t ₂ after the mark 33 is within the allowable range.

FIG. 6A shows a prediction function f (t) when the positional deviation amount of a certain mark 33 tends to decrease, the wafer 4 is gradually cooling, and the influence of thermal distortion is decreasing. Yes. FIG. 6B is a diagram for explaining a correction amount calculated in S803 and a correction amount necessary in S90, which is a part of the prediction function f (t). Even when f (t) is a decreasing function, the main control unit 20 obtains the position of the mark 33 at time t ₂ using the prediction function f (t), as described above.

If, when the timing of next measurement the position of the mark 33 was the time t ₂ later, the drawing position of the area adjacent to the regions already rendered to be applied to the present embodiment, joining tolerance There is a risk of significantly exceeding. On the other hand, by applying this embodiment, if the irradiation position is corrected with a correction amount obtained by the main control unit 20 at a timing at which correction is easy to be performed, the joining accuracy between patterns in adjacent regions is set to a predetermined value. It can be kept within the allowable range. Since the change in the position of the mark 33 used for calculating the correction amount is an actual measurement value, the correction can be performed by comprehensively considering the influence of heat on the wafer 4. As a result, a decrease in pattern overlay accuracy or stitching accuracy can be reduced.

  When trying to keep the joining accuracy within a predetermined range by another method, it is necessary to frequently measure the position of the mark 33 in order to prevent the position measurement timing of the mark 33 from becoming too late. . However, for that purpose, the throughput is reduced by increasing the number of measurements, and the structure of the drawing apparatus 1 is complicated by increasing the number of columns 13 and sensors 10 too much. According to the drawing apparatus and the drawing method according to the present embodiment, even when the timing of the position measurement of the mark 33 is late, the drawing position is corrected while reducing these adverse effects, and the pattern overlay accuracy or connection is reduced. A decrease in alignment accuracy can be reduced.

[Second Embodiment]
In the second embodiment, the main control unit 20 determines the correction amount using the result of calculating the second derivative of the prediction function f (t). Even when the first-order differential value is positive (the function tends to increase), is the degree of increase in the displacement amount of the mark 33 large (the second-order differential value is positive), or increases in the displacement amount of the mark 33 position? The correction amount is determined in consideration of whether the degree is small (second-order differential value is negative).

FIG. 7 is a table showing the relationship between the sign of the second-order differential value, the comparison result between the difference value and the allowable value, and the correction amount when the value of the first-order derivative of the prediction function f (t) is positive. The case is classified by the result of comparing the second-order differential value, the difference value and the allowable value, and a total of four cases (C1 to C4) are shown. Incidentally, the difference value, and the predicted deviation amount of the position of the mark 33 at time t _2, the most recent measurement value measured by the time t ₁ of the difference (the most recent by the measuring portion position information prediction section predicts measurement results of The absolute value of the difference.

  In any case, when the difference value is smaller than the allowable value (C2, C4), the correction need not be performed. Alternatively, correction is performed with a correction amount larger than 0 and smaller than the difference value.

  Next, the difference in correction amount between the case where the second-order differential value is positive and the case where it is negative will be described. When the value of the first order differential is positive and the second order differential value is also positive (C1), the thermal strain of the wafer 4 is in an accelerated state. In such a case, the correction amount is increased. For example, the difference value is equal to or greater than the difference value and equal to or less than the difference value plus an allowable value. On the other hand, when the value of the first order differential is positive and the second order differential value is also negative (C3), the thermal distortion of the wafer 4 is progressing little by little.

  However, there is a possibility that the thermal distortion of the wafer 4 tends to decrease in the area where the image is actually drawn after correction. Therefore, when the second-order differential value is negative, the correction amount is conservative, and the change in the position of the mark 33 can be seen. For example, the difference value is greater than or equal to the difference value and less than or equal to the difference value.

If the irradiation position of the electron beam on the wafer 4 is corrected using the result obtained by differentiating twice the function obtained from the time change of the position information of the mark 33 as in the present embodiment, the time t _{2 at} which the correction is performed is further corrected. It is possible to ensure the joining accuracy of the areas to be drawn at a later time.

[Other Embodiments]
The prediction function may not be calculated every time the predicted value is calculated. It is possible to use a function that is updated at a predetermined timing such as every time a predetermined number of times are drawn in the X-axis direction, every predetermined time, every time a predetermined energy is irradiated. Further, the calculation of the prediction function f (t) is not performed using all the history of the time history of the mark 33, but is calculated using a history for a predetermined time or a history of a predetermined number of times of measurement. Also good. It is preferable to update the prediction function f (t) at a higher frequency as the thermal strain rate of the wafer is higher. Further, it is preferable to calculate using the position of the mark 33 measured at a short time interval as compared with the case where the thermal strain rate of the wafer is slow.

  In each of the above-described embodiments, the positional deviation of the same mark in the X-axis direction has been described as an example. However, the correction amount and the direction thereof may be determined in combination with information on the positional deviation in the Y-axis direction. Alternatively, the amount of correction and the direction thereof may be determined by obtaining the total thermal distortion of the wafer 4 from the predicted deviation amounts of the positions of a plurality of marks at distant positions.

  Further, the marks measured in S40 and S60 are not necessarily the same mark. As long as the marks that can be considered to be affected by heat are equivalent to each other, the position shift amount may be obtained using offset information of positions between the marks. Note that two marks formed on a scribe line adjacent to a common shot can be cited as an example of marks that can be considered to be equally affected by heat.

  In the above-described embodiment, since the single mark 33 is measured by the sensors 10 having different arrangements, the reliability of the measurement value is lowered when there is a difference in performance between the sensors. Therefore, when there is a difference in performance between sensors, it is desirable to measure the same mark 33 in the same state in advance and store the offset value. The alignment sensor 9 is not always necessary. When the alignment sensor 9 is not provided, the measurement for determining the lattice arrangement (S10) is performed using the sensor 10, which facilitates component placement when the placement space of the sensor or the like is narrow, and reduces the cost of the drawing apparatus. Can be planned.

[Product Manufacturing Method]
The manufacturing method of the article of the present invention (semiconductor integrated circuit element, liquid crystal display element, image pickup element, magnetic head, CD-RW, optical element, photomask, etc.) uses the drawing apparatus of the above-described embodiment to form a substrate (wafer or A step of exposing the pattern onto a glass plate or the like, a step of developing the exposed substrate, and a step of performing at least one of an etching process and an ion implantation process on the developed substrate. Furthermore, other known processing steps (oxidation, film formation, vapor deposition, planarization, resist peeling, dicing, bonding, packaging, etc.) may be included.

DESCRIPTION OF SYMBOLS 1 Drawing apparatus 4 Wafer 9 Alignment sensor 11 Correction sensor 33 Mark 34 Alignment mark 20 Main control part 21 Control part (for electron source 2 and optical system 3)
22 Control unit (for stage)
24 Control unit (for sensor)

Claims (10)

A lithography apparatus that forms a pattern by irradiating a beam toward a substrate,
A measuring instrument for measuring the position of a mark formed on the substrate;
A prediction unit that predicts position information of the mark at a predetermined timing using measurement results measured at different timings by the measuring instrument;
A lithographic apparatus, comprising: a correction unit that corrects an irradiation position of the beam on the substrate based on position information predicted by the prediction unit.   The lithographic apparatus according to claim 1, wherein the prediction unit predicts the position information from a temporal change in the position of the mark obtained from the measurement result.   The lithographic apparatus according to claim 1, wherein the correction unit corrects an irradiation position of the beam on the substrate at the predetermined timing.   The correction unit corrects the irradiation position of the beam with respect to the substrate when a difference between position information predicted by the prediction unit and a latest measurement result by the measurement unit is outside an allowable range. Item 4. The lithographic apparatus according to any one of Items 1 to 3.   The correction unit applies the beam to the substrate so that a difference between a value obtained by applying a correction amount to the position information predicted by the prediction unit and a latest measurement result by the measurement unit is within the allowable range. The lithographic apparatus according to claim 1, wherein the position is corrected.   The correction unit corrects the irradiation position of the beam with respect to the substrate using a result obtained by second-order differentiation of a function obtained from a temporal change in the position of the mark. The lithographic apparatus according to Item.   When the absolute value of the difference between the position information predicted by the prediction unit and the most recent measurement result by the measurement unit is outside an allowable value and the second-order differential result is positive, the correction unit calculates the correction amount. When the beam irradiation position on the substrate is corrected to be equal to or larger than the absolute value of the difference, and the absolute value of the difference is outside an allowable value and the result of the second-order differentiation is negative, the correction unit calculates the correction amount. The lithographic apparatus according to claim 6, wherein the irradiation position of the beam with respect to the substrate is corrected with the absolute value of the difference being equal to or less than the absolute value of the difference.   The lithographic apparatus according to claim 1, comprising a plurality of the measuring instruments. Measuring the position of the mark formed on the substrate at different timings;
Predicting the position of the mark at a predetermined timing from the position of the mark measured at the different timing;
Correcting the irradiation position of the beam with respect to the substrate based on the predicted position of the mark. A lithographic apparatus according to any one of claims 1 to 8,
Irradiating the substrate with a beam;
Developing the substrate irradiated with the beam;
And a step of performing at least one of an etching process and an ion implantation process on the developed substrate.

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