JP2014099562A - Exposure device, exposure method and manufacturing method of device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exposure device which is advantageous for reducing defocus while suppressing reduction of throughput.SOLUTION: On the basis of first measurements which are acquired beforehand, of heights of a plurality of shot regions of an n-th substrate, the n-th substrate is exposed while focusing each of the plurality of shot regions of the n-th substrate on a stage. Second measurements are acquired by measuring heights of the plurality of shot regions by means of a measuring section. When exposing (n+1)th and subsequent substrates among a plurality of substrates, a third measurement is acquired by measuring a height of one shot region among a plurality of shot regions of the (n+1)th and subsequent substrates by means of the measuring section. On the basis of a differential between a measurement which is included in the first measurements, of a height of a shot region corresponding to the one shot region and the third measurement, the first measurements and the second measurements, the (n+1)th and subsequent substrates are exposed while focusing the plurality of shot regions of the (n+1)th and subsequent substrates on the stage.

Description

  The present invention relates to an exposure apparatus, an exposure method, and a device manufacturing method.

  When manufacturing a semiconductor device or the like using photolithography technology, a step-and-scan type exposure apparatus (scanner) that transfers a reticle pattern while scanning the reticle and the substrate is used. The scanner corrects an offset necessary for aligning the shot area (exposure area) on the substrate with the best focus surface using information acquired from the position measurement sensor during the exposure process of the substrate (see Patent Document 1). ). However, as in Patent Document 1, when the best focus surface is obtained during the exposure process and the shot area is sent to the best focus surface (that is, using real-time autofocus), the processing speed (throughput) of the exposure apparatus is reduced. Will be invited. This is because the exposure process must be performed after the substrate stage is moved by an amount corresponding to the pre-measurement (prefetching) of the shot area on the substrate by the position measurement sensor.

  Therefore, a technique for suppressing a reduction in throughput of the exposure apparatus in a process with a deep focal depth has been proposed (see Patent Document 2). In Patent Document 2, among a plurality of substrates (lots) processed in the same process, the height of all shot regions is measured for the first substrate, and the first shot region is used for the second and subsequent substrates. Measure only the height. For the second and subsequent shot areas of the second and subsequent substrates, the difference (correction value) between the height of the first shot area of the first substrate and the height of the first shot area of the second substrate is calculated. It is used to correct the focus. In Patent Document 2, it is a necessary condition that the surface shapes of the substrates are substantially the same in lots processed in the same process.

JP 2003-203838 A JP-A-6-20923

  However, even in a lot processed in the same process, since the surface shape actually varies among a plurality of substrates, defocusing occurs if the variation is larger than the focus allowable amount.

  In addition, the substrate is held on the substrate stage, and the surface shape of the substrate follows the shape (surface shape) of the substrate holding surface of the substrate stage, but the substrate holding surface is known to change over time due to its own weight and the like. Yes. For example, the measurement value of the height of the first shot region of the second and subsequent substrates is the same as the measurement value of the height of the first shot region of the first substrate, but the substrate due to the change over time of the substrate holding surface In some cases, the deformation of the surface shape is larger than the focus tolerance. In the prior art, such a deformation of the surface shape of the substrate cannot be detected, and an appropriate correction value cannot be reflected to other shot areas. Therefore, exposure processing is performed without considering the tilt component of the actual substrate (shot region), which causes defocusing.

  These problems can be avoided by measuring the height of all shot areas on all substrates and using that result to correct the focus during the exposure process, but the throughput of the exposure apparatus decreases. End up.

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide an exposure apparatus that is advantageous in reducing defocus while suppressing a decrease in throughput.

  In order to achieve the above object, an exposure apparatus according to one aspect of the present invention is an exposure apparatus that continuously exposes a plurality of substrates, a stage that holds and moves the substrate, and a shot area of the substrate A measurement unit that measures the height of the plurality of substrates, and a control unit that controls exposure of each of the plurality of substrates, wherein the control unit is the nth (n is a natural number) from the top of the plurality of substrates. In the case of exposing up to the substrate, each of the plurality of shot regions of the n-th substrate based on the first measurement value of the height of each of the plurality of shot regions of the n-th substrate obtained in advance. In the exposure, the height of each of the plurality of shot areas is measured by the measurement unit to obtain a second measurement value, and n + 1 of the plurality of substrates is obtained. After the first When exposing the substrate, the measurement unit measures the height of one shot region among a plurality of shot regions of the (n + 1) th and subsequent substrates to obtain a third measurement value, and the first measurement value The n + 1st and subsequent sheets based on the difference between the measurement value of the shot area corresponding to the one shot area included in the image and the third measurement value, the first measurement value, and the second measurement value Each of the plurality of shot areas of the substrate is exposed while adjusting the focus on the stage.

  Further objects and other aspects of the present invention will become apparent from the preferred embodiments described below with reference to the accompanying drawings.

  According to the present invention, for example, it is possible to provide an exposure apparatus that is advantageous in reducing defocus while suppressing a decrease in throughput.

It is the schematic which shows the structure of the exposure apparatus as 1 side surface of this invention. 2 is a flowchart for explaining an exposure process for continuously exposing a plurality of substrates in the exposure apparatus shown in FIG. 1. 2 is a flowchart for explaining an exposure process for continuously exposing a plurality of substrates in the exposure apparatus shown in FIG. 1. It is a figure which shows an example of the arrangement | sequence of the shot area | region of a board | substrate.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the accompanying drawings. In addition, in each figure, the same reference number is attached | subjected about the same member and the overlapping description is abbreviate | omitted.

  FIG. 1 is a schematic view showing a configuration of an exposure apparatus 1 as one aspect of the present invention. However, FIG. 1 shows only a part of members constituting the exposure apparatus 1, that is, only members related to the present invention. The exposure apparatus 1 is a lithography apparatus that transfers a reticle pattern onto a substrate by a step-and-scan method. In this embodiment, the exposure apparatus 1 continuously exposes a plurality of substrates (lots) processed in the same process.

  The exposure apparatus 1 includes an illumination optical system (not shown) that illuminates a reticle, a projection optical system (not shown) that projects a reticle pattern onto a substrate, a substrate stage 10 that moves while holding the substrate SB, and a measurement unit 20 and a control unit 30.

  The substrate stage 10 has a chuck (substrate holding surface) 12 for holding the substrate SB. The substrate stage 10 has a drive system including four actuators 14a, 14b, 14c, and 14d, and is configured to be movable in each of the X-axis direction, the Y-axis direction, the Z-axis direction, and the Z-axis rotation direction. The

  The measurement unit 20 is disposed between the projection optical system and the substrate stage 10 and measures the height (position in the Z-axis direction) of the shot area of the substrate SB. The measurement unit 20 includes, for example, four Z measurement sensors 21, 22, 23, and 24, and measures the height at a plurality of measurement points in the shot region of the substrate SB.

  The control unit 30 includes a CPU 32 and a memory (storage unit) 34 and controls the whole (operation) of the exposure apparatus 1. For example, the control unit 30 controls the exposure of each of the plurality of substrates SB processed in the same process (that is, controls the exposure process for continuously exposing the plurality of substrates SB). At this time, the control unit 30 focuses on the basis of the measurement result of the measurement unit 20 so that each of the plurality of shot regions of the substrate SB is positioned at the best focus position via the substrate stage 10 holding the substrate SB. Make adjustments.

  With reference to FIG. 2, an exposure process for continuously exposing a plurality of substrates SB in the exposure apparatus 1 will be described. As described above, the exposure process is performed by the control unit 30 controlling the respective units of the exposure apparatus 1 in an integrated manner. Here, it is assumed that the exposure process is started from the state where the substrate SB is held on the substrate stage 10. The measurement unit 20 measures the difference between the shot area and the reference position (best focus position) that serves as a reference for focus adjustment as the height of the shot area that is the height of the substrate SB. FIG. 2A shows an exposure process for the first substrate SB among the plurality of substrates SB, and FIG. 2B shows an exposure process for the second substrate SB among the plurality of substrates SB. Yes.

  First, an exposure process for the first substrate SB will be described. In S202, the substrate stage 10 is moved so that the first shot area (first shot area) of the first substrate SB is positioned at the measurement position of the measurement unit 20. In S204, the height of the first shot area of the first substrate SB is measured by the measurement unit 20 to obtain a measurement value. In S206, the measurement value acquired in S204 (the measurement value of the height of the first shot area of the first substrate SB) is stored in the memory 34.

  In S208, it is determined whether or not the heights of all the shot areas of the first substrate SB have been measured. When the heights of all the shot areas of the first substrate SB are measured, the process proceeds to S216. If the heights of all the shot areas of the first substrate SB have not been measured, the process proceeds to S210.

In S210, the substrate stage 10 is placed so that the next shot area of the first substrate SB (that is, the shot area where the height is not measured (measurement target shot area)) is positioned at the measurement position of the measurement unit 20. Moving. In S212, the measurement unit 20 measures the height of the measurement target shot area of the first substrate SB and acquires the measurement value. In S214, the measurement value acquired in S212 (the measurement value of the height of the measurement target shot area of the first substrate SB) is stored in the memory 34. Through the processes of S202 to S214, the measurement values of the heights of all the shot areas of the first substrate SB are acquired. Such measurement values, that is, measurement values of the heights of the plurality of shot regions of the first substrate SB acquired in advance before the exposure of the first substrate SB are hereinafter referred to as measurement values S _1. .

In S216, the measurement values _{S 1} was previously obtained as a correction value _{X 1} of the focus adjustment _(i.e., X 1 _{= S 1),} the substrate so that each of the plurality of shot regions of the substrate SB is positioned to the best focus position stage 10 Each shot area is exposed while moving. Further, in the exposure, by measuring the height of each of the plurality of shot regions of the first sheet of the substrate SB in the measuring unit 20 obtains the measured value is stored in the memory 34 as a measurement value P _1.

Here, the measurement value S ₁ , the measurement value P _1, and the correction amount X ₁ are arranged. Measured values S _1, the height of each shot area of the substrate SB obtained from the measurement by the measuring unit 20 and the (Z-axis direction position) which is the difference between the best focus position. Measurement P ₁ is the difference between the height and the best focus position of each shot area of the substrate SB obtained from the measurement by the measuring unit 20 during the exposure of the first substrate SB. Correction amount X _1, the correction amount in the focus adjustment, specifically, the position of the Z-axis direction of the substrate stage 10 during the exposure of the first substrate SB.

  Next, an exposure process for the second substrate SB will be described. In S252, the substrate stage 10 is moved so that the first shot area (first shot area) of the second substrate SB is positioned at the measurement position of the measurement unit 20. In S254, the measurement value is obtained by measuring the height of the first shot area of the second substrate SB with the measuring unit 20.

In S256, the high of the first said shot area second substrate SB acquired in the measurement value of the height of the first shot area of the first substrate SB included in the measured values S ₁ stored and S254 in S206 The difference from the measured value is calculated.

In S258, to calculate the sum value by adding the measured values S ₁ stored the calculated difference in S206 _(i.e., measured values of the height of each shot area of the first sheet of substrate SB) in S256, the addition value S ₂ is stored in the memory 34.

In S260, in consideration of the measured values P ₁ of the height of the respective shot areas measured by the measuring unit 20 during the exposure of the first substrate SB, to expose the second substrate SB. Specifically, a value obtained by adding the addition value _{S 2} stored in the measured value _{P 1} stored in the S258 and the correction value _{X 2} of the focus adjustment S216 _{(i.e., X 2 = P 1 + S} 2). Then, using the correction value X _2, exposing the respective shot areas while moving the substrate stage 10 so that each of the plurality of shot regions of the substrate SB is positioned in the best focus position. Further, in the exposure, the respective heights of the plurality of shot areas second substrate SB is measured by the measuring unit 20 obtains the measured value is stored in the memory 34 as a measurement value P _2.

Here, the exposure process for the pth substrate (p is a natural number of 3 or more) is also described. An addition value obtained by adding the difference between the measured value of the first shot area of the first substrate SB and the measured value of the height of the first shot area of the p-th substrate to the measured value S ₁ is represented by _Sp. And When the height of the measured values of each shot area measured by the measuring unit 20 during exposure of the q th substrate SB and P _q, the correction value X _p of the focus adjustment when exposing the substrate SB p th is Is given by the following equation (1).

In Expression (1), m represents the number of samples. Therefore, the expression (1) is obtained by using the measurement value of the height of each shot area measured by the measurement unit 20 during the exposure of the substrate from the pmth to the p−1th substrates. it represents that calculates the correction value X _p of the focus adjustment when exposing the.

P _q should ideally always be zero. However, as described above, since the chuck (substrate holding surface) 12 of the substrate stage 10 changes with time due to its own weight or the like, P _q does not actually become 0 (P _q ≠ 0). Therefore, in the present embodiment, when the p-th substrate SB is exposed, the measurement value of the height of each shot region measured by the measurement unit 20 at the time of exposure of the p-1th substrate SB is taken into consideration. Yes. The correction value X _p of the focus adjustment when exposing the substrate SB p th is not intended to be limited to the following equation (1). For example, the correction value _{X p may} be given by _{X p = P p-1 +} S p.

  In the exposure apparatus 1 of the present embodiment, when exposing the first to n-th (n is a natural number) of the plurality of substrates, the height of each of the plurality of shot areas is set in the exposure of the substrate. A measurement value (second measurement value) is acquired by measurement by the measurement unit 20. For the exposure of the substrate, the substrate stage 10 adjusts the focus for each of the plurality of shot regions based on the height measurement values (first measurement values) of the plurality of shot regions acquired in advance. Exposure.

  Further, when the n + 1 and subsequent substrates are exposed, the height of one shot area of the plurality of shot areas of the substrate is measured by the measurement unit 20 before the exposure, and a measured value (third measured value) is measured. ) To get. Then, a plurality of shots are obtained based on the difference between the measurement value of the shot area corresponding to one shot area included in the first measurement value and the third measurement value, the first measurement value, and the second measurement value. Each region is exposed while the focus is adjusted by the substrate stage 10. Further, in the exposure of the (n + 1) th and subsequent substrates, the measurement unit 20 measures the heights of the plurality of shot areas to obtain measurement values (fourth measurement values).

  When the i-th (i> n + 1) substrate is exposed, the height of one shot area of the plurality of shot areas of the substrate is measured by the measurement unit 20 and the measurement value (fifth measurement value) is measured. ) To get. Next, a difference between the measurement value of the height of the shot area corresponding to one shot area included in the first measurement value and the fifth measurement value is obtained. Then, the substrate stage 10 for each of the plurality of shot regions based on the difference, the first measurement value, and the average value of the fourth measurement value and the second measurement value acquired for the n + 1st substrate. Use to adjust the focus. Further, exposure is performed while adjusting the focus on the substrate stage 10 for each of a plurality of shot regions based on the difference, the first measurement value, and the fourth measurement value acquired for the (i−1) th substrate. Also good.

  As described above, in the exposure apparatus 1 of the present embodiment, the exposure is performed in consideration of the measurement values obtained by measuring the heights of the plurality of shot areas of the substrate exposed so far with respect to the substrate to be exposed. Focus adjustment is performed on each of a plurality of shot areas of the target substrate. Therefore, even when the surface shape varies among a plurality of substrates, or even when the surface shape of the substrate is deformed due to aging of the chuck (substrate holding surface) 12 of the substrate stage 10, the exposure apparatus 1 performs the exposure process. The defocus in can be reduced. Further, the exposure apparatus 1 measures the height of all shot areas for the first to n-th (for example, the first) of the plurality of substrates before exposure, and 1 for the other substrates. Only the height of one shot area is measured. Therefore, the exposure apparatus 1 can suppress a decrease in throughput as compared with a case where the heights of all shot areas are measured for all of the plurality of substrates.

  Further, in the exposure apparatus 1, before the exposure, the height of a part of the shot areas of the substrate is measured by the measuring unit 20 to obtain a measured value (sixth measured value), and the first measurement is performed. If the difference between the value and the sixth measurement value exceeds the allowable range, exposure of the substrate can be stopped. With reference to FIG. 3, the exposure process will be described. Further, as shown in FIG. 4, each of the plurality of substrates SB has six shot areas (first to sixth shot areas) in which three shot areas are arranged in the row direction and two shot areas are arranged in the column direction. ). FIG. 4 shows the position of the Z measurement sensors 21 to 24 of the measuring unit 20 at the exposure preparation position EP6 for exposing the sixth shot area and the moving direction of the substrate stage 10 when exposing the sixth shot area. MD6 is shown. Similarly, FIG. 4 shows the position of the Z measurement sensors 21 to 24 of the measurement unit 20 at the exposure preparation position EP5 for exposing the fifth shot area and the movement of the substrate stage 10 when exposing the fifth shot area. Direction MD5 is shown. Similarly, FIG. 4 shows the position of the Z measurement sensors 21 to 24 of the measuring unit 20 at the exposure preparation position EP4 for exposing the fourth shot area and the movement of the substrate stage 10 when exposing the fourth shot area. Direction MD4 is shown.

  With reference to FIG. 3A, an exposure process for the first substrate SB will be described. Since S302 to S314 are the same as S202 to S214 shown in FIG. 2, detailed description thereof is omitted here. In S316, the substrate stage 10 is moved to an exposure preparation position for exposing the exposure target shot area of the substrate SB.

  In S318, whether or not the measurement unit 20 (Z measurement sensors 21 to 24) is located inside the substrate SB at the exposure preparation position for exposing the exposure target shot area (that is, whether or not it is located in the shot area). ). If the measurement unit 20 is not located inside the substrate SB, the process proceeds to S324. If the measurement unit 20 is located inside the substrate SB, the process proceeds to S320.

  In S320, the measurement unit 20 measures the height of the shot area of the substrate SB where the measurement unit 20 is located at the exposure preparation position, and acquires a measurement value. In S322, the measurement value acquired in S320 (the measurement value of the height of the shot area of the substrate SB where the measurement unit 20 is located at the exposure preparation position) is stored in the memory 34 as a reference value.

  For example, referring to FIG. 4, at the exposure preparation position EP5, since the measurement unit 20 is located outside the substrate SB, the height of the shot area of the substrate SB cannot be measured. On the other hand, at the exposure preparation position EP6, since the measurement unit 20 is located inside the substrate SB, specifically, in the first shot region of the substrate SB, the height of the first shot region can be measured. Further, at the exposure preparation position EP4, since the measuring unit 20 is located in the third shot area of the substrate SB, the height of the third shot area can be measured.

In S324 moving, the measured values _{S 1} was previously obtained as a correction value _{X 1} of the focus adjustment _(i.e., X 1 _{= S} 1), the substrate stage 10 so that the exposure target shot region of the substrate SB is positioned in the best focus position The exposure target shot area is exposed while performing Further, in the exposure, the height of the exposure target shot region of the substrate SB is measured by the measurement unit 20 obtains the measured value is stored in the memory 34 as a measurement value P _1.

  In S326, it is determined whether or not all shot areas of the substrate SB have been exposed. When all the shot areas of the substrate SB are exposed, the exposure processing for the first substrate SB is finished. If all the shot areas of the substrate SB are not exposed, the process proceeds to S316, and the substrate stage 10 is moved to the exposure preparation position for exposing the next exposure target shot area of the substrate SB.

  With reference to FIG. 3B, an exposure process for the second and subsequent substrates SB will be described. Since S352 to S358 are the same as S252 to S258 shown in FIG. 2, a detailed description thereof is omitted here. In S360, the substrate stage 10 is moved to the exposure preparation position for exposing the exposure target shot area of the substrate SB.

  In S362, whether or not the measurement unit 20 (Z measurement sensors 21 to 24) is located inside the substrate SB at the exposure preparation position for exposing the exposure target shot area (that is, whether or not it is located in the shot area). ). If the measurement unit 20 is not located inside the substrate SB, the process proceeds to S372. If the measurement unit 20 is located inside the substrate SB, the process proceeds to S364.

  In S364, the measurement unit 20 measures the height of the shot area of the substrate SB where the measurement unit 20 is located at the exposure preparation position, and acquires a measurement value.

  In S366, the measurement value of the shot area height of the first substrate SB stored in S322, that is, the reference value and the measurement value of the shot area height of the second and subsequent substrates SB acquired in S364 are obtained. A comparison is made to determine whether the difference exceeds the allowable range. If the difference exceeds the allowable range, the process proceeds to S368, and the exposure of the substrate SB is stopped. When the difference does not exceed the allowable range, the process proceeds to S370. In S370, the measurement value acquired in S364 (measurement value of the height of the shot area of the substrate SB where the measurement unit 20 is located at the exposure preparation position) is stored in the memory 34 as a reference value (that is, the reference value is updated). To do).

In S372, in consideration of the measured values P ₁ of the height of the respective shot areas measured by the measuring unit 20 during the exposure of the first substrate SB, to expose the second substrate SB. Specifically, a value obtained by adding the addition value _{S 2} stored in the measured value _{P 1} stored in the S358 and the correction value _{X 2} of the focus adjustment S324 _{(i.e., X 2 = P 1 + S} 2). Then, using the correction value X _2, to expose the exposure target shot region while moving the substrate stage 10 so that the exposure target shot region of the substrate SB is positioned in the best focus position. Further, in the exposure, the height of the exposure target shot region of the second and subsequent substrate SB is measured by the measurement unit 20 obtains the measured value is stored in the memory 34 as a measurement value P _2.

  In S374, it is determined whether or not all shot areas of the substrate SB have been exposed. When all the shot areas of the substrate SB are exposed, the exposure processing for the second and subsequent substrates SB is finished. If all the shot areas of the substrate SB are not exposed, the process proceeds to S360, and the substrate stage 10 is moved to the exposure preparation position for exposing the next exposure target shot area of the substrate SB.

  As described above, when the difference between the height of the shot area of the substrate to be exposed and the height of the shot area of the substrate exposed before the exposure target exceeds an allowable range, that is, the surface shape between the substrates is deformed. If larger, the exposure of the substrate to be exposed is stopped. Thereby, it can suppress that the board | substrate of exposure object exposes with defocusing.

  As described above, the exposure apparatus 1 can provide a high-quality device (liquid crystal device, semiconductor element, imaging element (CCD, etc.), thin film magnetic head, etc.) with high throughput and good economic efficiency. Such a device includes a step of exposing a substrate (glass plate, wafer, etc.) coated with a photoresist (photosensitive agent) using the exposure apparatus 1, a step of developing the exposed substrate, and other known steps. , Manufactured by going through.

  As mentioned above, although preferable embodiment of this invention was described, it cannot be overemphasized that this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

Claims (10)

An exposure apparatus that continuously exposes a plurality of substrates,
A stage for holding and moving the substrate;
A measurement unit for measuring the height of the shot area of the substrate;
A control unit for controlling the exposure of each of the plurality of substrates,
The controller is
When exposing the first to n-th (n is a natural number) of the plurality of substrates, the first measurement values of the respective heights of the plurality of shot areas of the n-th substrate acquired in advance are used. Based on the above, each of the plurality of shot areas of the nth substrate is exposed while adjusting the focus on the stage, and the height of each of the plurality of shot areas is measured by the measurement unit in the exposure. To get the second measurement value,
In the case of exposing the (n + 1) th and subsequent substrates among the plurality of substrates, the height of one shot region among the plurality of shot regions of the (n + 1) th and subsequent substrates is measured by the measurement unit, and the third A measurement value is acquired, and the difference between the measurement value of the height of the shot area corresponding to the one shot area included in the first measurement value and the third measurement value, the first measurement value, and the first An exposure apparatus that performs exposure while adjusting focus on each of a plurality of shot areas of the (n + 1) th and subsequent substrates based on two measurement values.   The exposure apparatus according to claim 1, wherein the measurement unit measures a difference between the shot area and a reference position serving as a reference for the focus adjustment as a height of the shot area of the substrate.   The controller, when exposing the n + 1st and subsequent substrates, exposes each of a plurality of shot areas of the n + 1st and subsequent substrates while adjusting the focus on the stage, and The exposure apparatus according to claim 1, wherein a height of each shot area is measured by the measurement unit to obtain a fourth measurement value.   When the i-th (i> n + 1) substrate is exposed, the control unit measures the height of one shot area among the plurality of shot areas of the i-th substrate with the measurement unit. Obtaining a fifth measurement value, a difference between the measurement value of the height of the shot area corresponding to the one shot area included in the first measurement value and the fifth measurement value, the first measurement value, and Focus adjustment is performed on the stage for each of a plurality of shot areas of the i-th substrate based on an average value of the fourth measurement value and the second measurement value acquired for the n + 1st substrate. The exposure apparatus according to claim 3, wherein the exposure is performed while performing exposure.   When the i-th (i> n + 1) substrate is exposed, the control unit measures the height of one shot area among the plurality of shot areas of the i-th substrate with the measurement unit. Obtaining a fifth measurement value, a difference between the measurement value of the height of the shot area corresponding to the one shot area included in the first measurement value and the fifth measurement value, the first measurement value, and The exposure is performed while adjusting the focus on the stage with respect to each of a plurality of shot regions of the i-th substrate based on the fourth measurement value acquired for the i-th substrate. The exposure apparatus according to claim 3.   The controller measures the height of a part of the shot areas of the plurality of shot areas on the substrate by the measuring unit before the exposure to obtain a sixth measured value, and the first measured value and the sixth 2. The exposure apparatus according to claim 1, wherein the exposure of the substrate is stopped if the difference from the measured value exceeds an allowable range.   The exposure apparatus according to claim 6, wherein the measurement by the measurement unit for obtaining the sixth measurement value is performed at an exposure preparation position for exposing a shot area to be exposed.   2. The exposure apparatus according to claim 1, wherein the first measurement value is acquired by measuring a height of each of a plurality of shot regions of the n-th substrate with the measurement unit. An exposure method for continuously exposing a plurality of substrates,
When exposing the first to n-th (n is a natural number) of the plurality of substrates, the first measurement values of the respective heights of the plurality of shot areas of the n-th substrate acquired in advance are used. And performing exposure while adjusting the focus on each of the plurality of shot areas of the n-th substrate, and measuring the height of each of the plurality of shot areas in the exposure to obtain a second measurement value And
When exposing the n + 1st and subsequent substrates of the plurality of substrates, the third measurement value is obtained by measuring the height of one shot region among the plurality of shot regions of the n + 1st and subsequent substrates. The difference between the measured value of the shot area corresponding to the one shot area included in the first measured value and the third measured value, the first measured value, and the second measured value An exposure method characterized in that exposure is performed while adjusting the focus for each of a plurality of shot areas of the (n + 1) th and subsequent substrates. Exposing the substrate using the exposure apparatus according to any one of claims 1 to 8,
Developing the exposed substrate;
A device manufacturing method characterized by comprising:

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