JP2009194204A - Aligner, exposure system, and method of manufacturing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aligner, an exposure system, and a manufacturing method of a device, comprising a reflective optical system which suppresses combined error due to characteristics of respective aligners even if each of the aligners has its tolerable precision range, for improved yield of a device. <P>SOLUTION: The aligner comprises a mask holding part which holds a mask having a pattern surface on which a first pattern is formed, a substrate holding part which holds a substrate where a pattern region containing a second pattern is formed, a pattern distortion measuring part which measures distortion of a pattern region of the substrate held by the substrate holding part or the second pattern, a correction value calculating part which calculates a correction value for compensating a distortion according to the pattern region measured by the pattern distortion measuring part or the distortion of the second pattern, and a control part which controls shape of the pattern surface of a mask based on the correction value calculated by the correction value calculating part. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an exposure apparatus, an exposure system, and a device manufacturing method. More specifically, the present invention relates to an exposure apparatus that performs exposure processing of a substrate using a mask or a reticle, an exposure system that includes the exposure apparatus, and a device manufacturing method that uses the exposure apparatus or the exposure system.

  There is a constant demand for improving the resolution of a lithography technique for forming a pattern on a substrate surface such as a wafer or a glass plate coated with a resist. With the development of technologies such as modified illumination, phase shift mask, optical proximity effect correction, and immersion exposure, 45 nm rule photolithography technology has already been put into practical use. Furthermore, with regard to lithography of 32 nm rule and smaller, there is an expectation for extreme ultraviolet lithography technology in which the wavelength of exposure light is 10 to 14 nm.

However, a glass material that transmits extreme ultraviolet light as exposure light with low loss is not known. Therefore, a reflection type optical system is used in an exposure apparatus that uses extreme ultraviolet light as exposure light. The mask is also of a reflective type (see, for example, Patent Document 1).
JP-A-2005-004146

  In the manufacturing process of devices such as semiconductor devices and electronic devices, a plurality of shot regions are formed on the surface of a single substrate, and the exposure process is performed many times for each shot region. In lithography of 32 nm rule and smaller, there is a demand for improving device yield by suppressing overlay errors between stacked patterns.

  In a mass production process for semiconductor devices, electronic devices, and the like, an exposure process may be performed using a plurality of exposure apparatuses for each shot region of a single substrate. Even in such a case, even if each exposure apparatus has an accuracy within an allowable range, there is a demand for improving the device yield by suppressing the overlay error due to the characteristics of each exposure apparatus.

  In order to solve the above problems, as a first embodiment of the present invention, there is provided a mask holding portion for holding a mask having a pattern surface on which a first pattern is formed, and a substrate on which a pattern region having a second pattern is formed. Information on the substrate holding unit to be held, the pattern distortion measuring unit for measuring the distortion of the pattern region or the second pattern of the substrate held by the substrate holding unit, and the distortion of the pattern region or the second pattern measured by the pattern distortion measuring unit Is provided with a control unit for controlling the shape of the pattern surface of the mask.

  Further, as a second aspect of the present invention, a mask holding unit that holds a mask having a pattern surface on which a first pattern is formed, and a substrate holding unit that holds a substrate on which a pattern region having a second pattern is formed. And an exposure apparatus comprising a control unit for controlling the shape of the pattern surface of the mask, a distortion measurement device unit for measuring distortion of the pattern region of the substrate or the second pattern, and information relating to distortion measured by the distortion measurement device Is provided with a control device for controlling the shape of the pattern surface of the mask held by the mask holding unit.

  Further, as a third aspect of the present invention, a step of preparing a mask having a pattern surface on which a first pattern is formed, a step of preparing a substrate on which a pattern region having a second pattern is formed, The step of measuring the distortion of the pattern region or the second pattern, the step of controlling the shape of the pattern surface of the mask according to the distortion of the pattern region or the second pattern, Exposing a first pattern onto a second pattern formed in a pattern region. A device manufacturing method is provided.

  The above summary of the present invention does not enumerate all necessary features of the present invention. Further, a sub-combination of these feature groups can be an invention.

  Hereinafter, the present invention will be described through embodiments of the invention. However, the following embodiments do not limit the invention according to the claims. In addition, not all the combinations of features described in the embodiments are essential for the solving means of the invention.

  FIG. 1 is a diagram schematically showing the entire structure of the exposure apparatus 100. As shown in FIG. The exposure apparatus 100 includes a light source unit 110, an illumination optical system 120, a mask stage 130, a projection optical system 140, a substrate stage 150, and a chamber 160 that accommodates them. In the following description, when a position, a direction, and the like are indicated, it may be described as “up” or “down” according to the display of the drawing. However, the layout inside the exposure apparatus 100 is not limited to that direction.

  The chamber 160 has an opening on its side surface that is hermetically sealed by the sealing window 162. Further, the chamber 160 has an exhaust hole 164 connected to an exhaust device (not shown) on the bottom surface. As a result, an environment is defined in which the interior of the chamber 160 is evacuated and exposure processing can be performed without being affected by the external atmosphere.

  The light source unit 110 includes a target nozzle 112, a concave reflecting mirror 114, a laser light source 170, and a condenser lens 172. The target nozzle 112 has a tip for discharging the target material inside the chamber 160. The concave reflecting mirror 114 surrounds the vicinity of the tip of the target nozzle 112. The laser light source 170 is disposed outside the chamber 160 and irradiates laser light toward the inside of the chamber 160 through the sealing window 162.

  In the light source unit 110, the target nozzle 112 intermittently discharges a gas or liquid target material. The laser light emitted from the laser light source 170 is converged by the condensing lens 172 and irradiated to the discharged target material at a high density. Thereby, pulsed extreme ultraviolet rays (hereinafter referred to as exposure light) are radiated from the plasma target material. The emitted exposure light is guided in a fixed direction by the concave reflecting mirror 114 and guided to the illumination optical system 120.

In the above embodiment, the light source unit 110 emits extreme ultraviolet exposure light. For example, g-line (436 nm), i-line (365 nm), KrF excimer laser (248 nm), F ₂ laser (157 nm), Kr A light source unit 110 that emits ₂ laser (146 nm), Ar ₂ laser (126 nm), or the like as exposure light may be used.

  The illumination optical system 120 includes concave reflecting mirrors 121 and 126, fly-eye reflecting mirrors 122 and 123, a convex reflecting mirror 125, and a flat reflecting mirror 127. The exposure light incident on the illumination optical system 120 from the concave reflecting mirror 114 is reflected by the concave reflecting mirror 121 disposed at the incident end of the illumination optical system 120 and collimated. The collimated exposure light is sequentially reflected by the pair of fly-eye reflecting mirrors 122 and 123 that form the optical integrator 124.

  The exposure light emitted from the fly-eye reflecting mirror 123 is sequentially reflected by the convex reflecting mirror 125 and the concave reflecting mirror 126 and then deflected by the flat reflecting mirror 127. The deflected exposure light is applied to the lower surface (pattern surface) of the mask 180 held on the mask stage 130 through the openings of the movable light shielding blade 128 and the fixed light shielding blade 129.

  In the present embodiment, the illumination region that illuminates the pattern surface of the mask 180 is formed in an arc shape elongated in the X direction by the movable light shielding blade 128 and the fixed light shielding blade 129.

  The mask 180 includes a surface to be attracted electrostatically to the mask holding unit 200 and a pattern surface 182 (see FIG. 2) having a pattern formation region 184 in which a first pattern 186 having a predetermined circuit pattern is formed. .

  The pattern surface 182 includes a plurality of reflective layers that form a reflective surface that reflects extreme ultraviolet light, and is laminated on the reflective layer, and partially on the reflective surface corresponding to a predetermined circuit pattern and alignment mark. And an absorption layer formed on the substrate. The absorbing layer absorbs the irradiated exposure light, and reflects the irradiated exposure light toward the projection optical system 140 in the region where the reflection surface is exposed. Specifically, as shown in FIG. 2, the pattern surface 182 is formed with a pattern formation region 184 formed in the center of the pattern surface 182 and having a number of first patterns 186 as a predetermined circuit pattern. . Note that a plurality of alignment marks (not shown) used for alignment are formed on the pattern surface 182 so as to surround the pattern formation region 184. It is preferable that two or more alignment marks are provided on each of the four sides of the pattern formation region 184.

  Arc-shaped illumination areas 202 and 204 extending in the X direction are formed in part of the pattern surface 182 of the mask 180 by the exposure light that has passed through the openings of the movable light shielding blade 128 and the fixed light shielding blade 129.

  The projection optical system 140 includes a plurality of concave reflecting mirrors 141 and 144 and a plurality of convex reflecting mirrors 142 and 143. The reflecting optical system is non-telecentric on the object (mask) surface side and telecentric on the image surface (wafer) surface side. The projection magnification is a reduction magnification of 1/4 (or 1/5) or the like.

  The exposure light reflected by the mask 180 is projected onto the surface of a substrate 190 such as a wafer coated with a resist via the projection optical system 140, and the surface of the substrate 190 corresponds to the pattern formation region 184 of the mask 180. A shot region 194 (also referred to as a pattern region) is formed (see FIG. 2). In the shot area 194, an image of a pattern reflecting the shape of the absorption layer of the mask 180 is formed. A plurality of alignment mark images (not shown) are formed around the shot region 194.

  The mask stage 130 includes a stage unit 132 and a mask holding unit 200 supported on the lower side of the stage unit 132. The stage part 132 includes a base part 131 supported by a support base (not shown) and a support part 135 that supports the mask holding part 200. The mask holding unit 200 electrostatically attracts the mask 180. The detailed configuration of the mask holding unit 200 will be described later.

  The stage unit 132 can be driven with respect to the support base in the directions indicated by arrows X, Y, and Z in the drawing and in the rotation direction around the Z axis. On the other hand, the plurality of actuators 133 and 137 provided between the base portion 131 and the support portion 135 are individually expanded and contracted to tilt the support portion 135 with respect to the base portion 131 as indicated by an arrow T in the drawing. Can do.

  Accordingly, the mask holding unit 200 is also tilted as the support unit 135 is tilted, so that the angle of the mask 180 held by the mask holding unit 200 with respect to the horizontal plane can be arbitrarily changed. The tilt operation of the mask holding unit 200 is controlled by a mask focus sensor (not shown) that measures the height of the mask (position in the Z direction). The mask focus sensor has a light transmission system that projects a plurality of slit images on the surface of the mask 180 and a light receiving system that receives the slit image reflected by the surface of the mask 180.

  Similarly, the substrate stage 150 is also supported by the stage portion 152 that can be driven in the directions indicated by arrows X, Y, and Z in the drawing and in the rotational direction around the Z axis, and the substrate 190 is statically supported. And a chuck portion 154 for electroadsorption. Although not shown, in the vicinity of the chuck portion 154, a light transmission system for projecting a plurality of slit images on the surface of the substrate 190 and a light receiving system for receiving the slit images reflected on the surface of the substrate 190 are provided. A substrate focus sensor is provided, and the position of the substrate 190 in the Z direction with respect to the image plane of the projection optical system 140 is measured by the substrate focus sensor. Then, the control unit 310 controls the operation of the chuck unit 154 based on the measurement result of the substrate focus sensor, and adjusts the height and inclination of the substrate 190.

  Further, in the present embodiment, an alignment optical system 330 that measures alignment marks formed on the substrate 190 is provided in the vicinity of the side surface of the projection optical system 140. The alignment optical system 330 is configured to irradiate broadband light that does not expose the resist on the substrate 190 to the alignment mark on the substrate 190, receive the reflected light, and detect the mark by an image processing method.

  In the exposure apparatus 100, when the first pattern 186 formed in the pattern formation region 184 of the mask 180 is transferred to the substrate 190, exposure light irradiation from the illumination optical system 120 is started and the pattern formation region 184 is irradiated. A part is irradiated with exposure light. The mask 180 and the substrate 190 are reduced in speed with respect to the projection optical system 140 while the exposure light reflected by the pattern formation region 184 is projected onto one shot region of the substrate 190 via the projection optical system 140. As a ratio, the operation of synchronously moving in the Y direction and the operation of stopping the exposure light irradiation and moving the substrate 190 stepwise in the X and Y directions are repeated. By such repeated operations, the image of the first pattern 186 formed in the pattern formation region 184 is transferred to a plurality of shot regions on the substrate 190.

  By the way, in the device manufacturing process, it is necessary to repeat a plurality of exposure processes for overlaying different circuit patterns on each of the shot regions 194 formed on the substrate 190.

That is, a plurality of shot regions 194 having the second pattern 196 are already formed on the substrate 190 by the first exposure process using the first mask, and the second pattern 196 is subjected to the second time. That is, the first pattern 186 formed on the second mask 180 must be overlaid on the second pattern 196 for exposure.
When the first pattern 186 is overlaid on the second pattern 196 for exposure, the second pattern 196 already formed on the substrate 190 is affected by the aberration of the projection optical system 140 or the synchronization error between the mask 180 and the substrate 190. It may be distorted due to this. In particular, this distortion cannot be ignored as the line width of the pattern becomes thinner.

  In the present embodiment, an example will be described in which each shot region 194 of the substrate 190 is distorted due to distortion as an aberration of the projection optical system 140.

  FIG. 3 is a block diagram schematically showing the control system 300 of the exposure apparatus 100. The control system 300 includes a control unit 310 that controls the illumination optical system 120, the mask stage 130, the projection optical system 140, and the substrate stage 150, and the position of the alignment mark measured by the alignment optical system 330. And a calculation unit 340 for calculating distortion. In the figure, the same reference numerals are assigned to the same constituent elements as those in FIG.

  The alignment optical system 330 measures the positions of a plurality of alignment marks formed around each shot region 194 and outputs the measurement results to the calculation unit 340. Then, the calculation unit 340 determines the position of each alignment mark measured by the alignment optical system 330 and the reference position (for example, the design position or the position of the alignment mark formed without distortion in the shot region 194). Etc.).

  The calculation unit 340 calculates distortion information of each shot region 194 of the substrate 190 based on the comparison result between the measured position of the alignment mark and the reference position. In the present embodiment, as information on the distortion of each shot area 194, a position where distortion occurs in the shot area 194 and the amount of distortion at this position are obtained. The calculation unit 340 approximates the shape of the shot region 194 based on the measured position of the alignment mark, and compares the approximate shape of the shot region 194 with the designed shape of the shot region 194. Thus, distortion information of the shot area 194 may be calculated.

  The first pattern 186 projected on the substrate 190 is projected in accordance with the distortion of the second pattern 196 already formed on the substrate 190 based on the calculated distortion information of each shot region 194. Then, a correction position for deforming the pattern formation region 184 of the mask 180 and a correction value at the position are calculated.

  The information on the distortion of each shot area calculated by the calculation unit 340 and the correction position and correction value for deforming the pattern formation area 184 are stored in a storage device (memory) (not shown).

  The control unit 310 calls the correction position and correction value stored in the storage device, and controls the operation of the mask holding unit 200.

  The correction position and the correction value may be calculated for each shot region 194 formed on the substrate 190, or may be formed on the substrate if the distortion tendency of each shot region 194 is substantially the same. The calculation may be performed with an arbitrary number (for example, one) of shot areas 194 among the plurality of shot areas 194. Alternatively, when the exposure process is performed on a plurality of substrates 190, the correction position and the correction value may be calculated in the shot region 194 of the substrate 190 on which the exposure process is first performed.

  In addition, when distortion information is calculated for each shot area 194, the distortion information may be stored as map information in association with the shot area of the substrate 190.

  FIG. 4 is a cross-sectional view showing the structure of the mask holding unit 200. The mask holding unit 200 includes a base unit 210 supported by the support unit 135, an elastic support unit 220 disposed on the lower surface of the base unit 210, and a driving unit 230 disposed on the lower surface and inside of the base unit 210. . In the following description, the position or direction may be described as “up” or “down” in accordance with the display of the drawings. However, the structure and use of the mask holding unit 200 are not limited to this direction.

  The base portion 210 is a flat plate material supported by the support portion 135, and has high rigidity that does not substantially deform itself. On the other hand, the elastic support portion 220 has a shape in which one end portion (upper end portion in the present embodiment) is supported by the base portion 210 and the other end portion (lower end portion in the present embodiment) protrudes from the base portion 210. . The mask 180 is supported by the other end portion of the elastic support portion 220.

  Here, the elastic support part 220 has a greater degree of elastic deformation than the base part 210. That is, “the degree of elastic deformation is large” means that the amount of deformation generated when a certain stress is applied is larger in the elastic support portion 220 than in the base portion 210.

  Such a structure can be realized, for example, by forming the entire elastic support portion 220 with a material having a smaller elastic modulus than the base portion 210. Moreover, you may form a part of thickness direction of the elastic support part 220 with a material with a small elastic modulus. Alternatively, even when the elastic modulus of the material forming the elastic support portion 220 is equal to or larger than the elastic modulus of the material of the base portion 210, the shape of the elastic support portion 220 is more easily deformed than the base portion 210. Can also be realized.

  The drive unit 230 includes a plurality of electrodes 232 provided on a surface of the base unit 210 that supports the elastic support unit 220, and a drive line 234 individually connected at one end to each of the electrodes 232. The other end of the drive line 234 is connected to the control unit 310.

  The control unit 310 individually applies a driving voltage to the driving line 234 based on the correction position and the correction value calculated by the calculation unit 340, and individually changes the potential of the electrode 232. The electrode 232 whose potential has changed attracts an arbitrary region in the opposing pattern surface 182 individually by an electrostatic force corresponding to the potential. Thereby, the control unit 310 can deform the pattern formation region 184 by applying different forces to different regions of the pattern surface 182 including the pattern formation region 184. Therefore, the control unit 310 can vary the drive amount of the drive unit 230 for each different region of the pattern formation region 184 according to the distortion of each shot region 194 of the substrate 190.

  FIG. 5 is a perspective view showing an appearance of the mask holding unit 200. In the figure, the same reference numerals are assigned to the same components as those in FIG.

  The elastic support part 220 has a structure that repeats in different directions. That is, in this embodiment, both the linear part repeated in the X direction and the linear part repeated in the Y direction are included, and a lattice shape is formed. In the lattice-like elastic support portion 220, electrodes 232 are respectively arranged inside the lattices.

  Due to such a shape, the elastic support portion 220 supports the attracted surface on the side opposite to the pattern forming region 184 of the mask 180 at substantially equal intervals. Further, the electrodes 232 are evenly distributed with respect to the attracted surface of the mask 180. Note that the size of the lattice formed by the elastic support portion 220 can be changed according to the pattern shape formed in the pattern formation region 184 of the mask 180 to be adjusted.

  FIG. 6 is a diagram illustrating an operation for deforming the mask 180 of the mask holding unit 200. In this embodiment, when each of the shot regions 194 of the substrate 190 is distorted due to distortion in the non-scan direction (X direction in this embodiment), the pattern formation region 184 of the mask 180 is deformed in accordance with this distortion. The operation will be described.

  In the mask holding unit 200, each of the electrodes 232 is coupled to the voltage source V through the demultiplexer 312. The demultiplexer 312 is controlled by the control unit 310 and can make any electrode 232 conductive to the voltage source V.

  The control unit 310 determines a portion to be corrected and a correction amount thereof in the pattern formation region 184 of the mask 180 according to the correction value calculated by the calculation unit 340. Based on the correction amount, the drive voltage applied to the plurality of electrodes 232 is controlled so that only the portion to be corrected in the pattern formation region 184 is deformed.

  In the illustrated example, the region 181 is deformed by applying a high driving voltage to the two electrodes 232 A and D marked with Δ. The mask holding unit 200 has a function of holding the mask 180 as well as correcting the shape of the pattern formation region 184 of the mask 180. Accordingly, a constant drive voltage is applied to the other electrodes 232 that are not involved in the deformation of the pattern formation region 184.

  The timing for deforming the pattern formation region 184 of the mask 180 using the mask holding unit 200 may be before the mask stage 130 starts scanning exposure or after the scanning exposure is started. Further, the deformation of the pattern forming region 184 may be started before the start of scanning exposure, and the amount of deformation may be gradually added as the mask stage 130 moves.

  In the present embodiment, not only the pattern formation region 184 in the non-scan direction but also the pattern formation region 184 in the scan direction can be deformed. In addition, when the pattern formation region 184 is deformed with respect to the scanning direction, the tilt operation of the mask stage 130 can be used in combination.

  FIG. 7 is a diagram schematically showing a change in the first pattern projected onto the substrate 190 by deforming the pattern formation region 184. As shown in FIG. The control unit 310 controls the mask holding unit 200 to apply different forces to different regions of the pattern formation region 184 of the mask 180 to cause different deformations for each region.

  That is, as shown in FIG. 7A, it is not necessary to deform the pattern formation region 184 of the mask 180 in the shot region 194 of the substrate 190 if the amount of distortion is within an allowable range. In this case, the controller 310 controls the driving voltage applied to the plurality of electrodes 232 so as to attract the pattern formation region 184 of the mask 180 with a uniform electrostatic force. On the other hand, as shown in FIG. 7B, when there is a region in the shot region 194 of the substrate 190 where the amount of distortion exceeds the allowable range and is smaller than the design value, the control unit 310 Controls the drive voltage applied to the plurality of electrodes 232 such that the mask 180 is deformed into a convex shape. Furthermore, as shown in FIG. 7C, when there is a region in the shot region 194 of the substrate 190 where the distortion amount exceeds the allowable range and is larger than the design value, the control unit 310 performs masking. The drive voltage applied to the plurality of electrodes 232 is controlled so that 180 is deformed into a concave shape.

  As shown in FIG. 7, the controller 310 not only deforms the mask 180 into a convex shape or a concave shape, but can also cause different deformations for each region of the mask 180. Therefore, the mask 180 can be deformed in accordance with various distortions detected in the second pattern 196 of the substrate 190.

  Since the projection optical system 140 of the present embodiment is non-telecentric on the mask 180 side as described above, the portion where the pattern formation region 184 of the mask 180 is displaced in the Z-axis direction becomes an arc-shaped irradiation region on the mask 180. The projection position in the arc-shaped exposure region on the corresponding substrate 190 is shifted (moved) in the radial direction with respect to the center of the arc-shaped region. Therefore, the control unit 310 can improve the overlay accuracy of the substrate 190 on the shot region 194 by deforming the pattern formation region 184 of the mask 180 in consideration of the shift amount.

  In the above embodiment, the alignment optical system 330 is used to measure the position of the alignment mark provided around the shot area 194 formed on the substrate 190, and the shape of the shot area 194 is calculated. Instead of the alignment optical system 330, the shape of the shot region 194 may be calculated using an imaging device that can image the entire shot region. In this case, the position of the alignment mark need not be measured.

  In the case of using an imaging device, the shape of the second pattern 196 formed in the shot region is captured instead of the shape of the shot region 194, and the shape of the second pattern 196 itself and the ideal pattern shape are captured. May be compared.

  In this embodiment, using the exposure apparatus 100, a step of preparing a mask 180 having a pattern formation region 184 on which a first pattern 186 is formed, and a substrate on which a shot region 194 having a second pattern 196 is formed. 190, a step of measuring the distortion of the shot region 194 or the second pattern 196 of the substrate 190, and a step of calculating a correction value for compensating the distortion according to the distortion of the shot region 194 or the second pattern 196. Then, based on the calculated correction value, the stage of controlling the shape of the pattern formation region 184 of the mask 180 and the second pattern 196 formed in the shot region 194 of the substrate 190 in a state where the shape of the pattern formation region 184 is controlled. And a method of manufacturing a device including the step of exposing the first pattern 186. .

  FIG. 8 is a diagram schematically showing the structure of an exposure system 500 according to another embodiment. The exposure system 500 includes a distortion measurement device 520, a distortion tendency calculation device 530, a storage device 540, an extraction device 550, a host 560, and a plurality of exposure devices 100 connected to a common bus 510. Each of the distortion measurement device 520, the distortion tendency calculation device 530, the storage device 540, the extraction device 550, the host 560, and the exposure device 100 can transmit and receive signals to and from each other via the bus 510.

  The distortion measuring device 520 measures the distortion of the plurality of shot regions 194 or the second pattern 196 of the substrate 190 exposed by the exposure apparatus 100. Note that the strain measurement apparatus 520 may be disposed inside each exposure apparatus 100. Further, it may be arranged independently from the exposure apparatus 100. Further, it may be arranged both inside and outside the exposure apparatus 100.

  The distortion tendency calculation device 530 calculates a distortion tendency specific to each exposure apparatus 100 based on the measurement result of the distortion measurement device 520. As a result, it is possible to grasp the distortion that constantly occurs in each of the exposure apparatuses 100.

  The storage device 540 stores, in the exposure apparatus 100, the distortion information of the exposure apparatus 100 calculated by the distortion tendency calculation apparatus 530 and distortion information obtained by associating the distortion generated in the plurality of shot areas 194 of the substrate 190 with the substrate. The distortion tendency information stored in association with each other is accumulated. On the other hand, the extraction apparatus 550 refers to the distortion information and distortion tendency information stored in the storage apparatus 540 and extracts the exposure apparatus 100 having a tendency similar to the distortion generated in each substrate 190. The host 560 comprehensively controls such a series of operations, and when exposing the substrate 190 on which the second pattern 196 has already been formed, the exposure apparatus has a distortion tendency similar to that of the second pattern 196. Assign 100.

  In such an exposure system 500, the inherent distortion tendency of each exposure apparatus 100 and the distortion tendency of the plurality of shot regions 194 formed on the substrate 190 are similar to each other. The deformation amount of the mask 180 can be reduced. Further, the shape of the pattern formation region 184 of the mask 180 can be optimally changed with respect to the distortion of the shot region formed on the substrate 190, and the overlay accuracy can be improved.

  FIG. 9 is a cross-sectional view showing the structure of a mask 180 according to another embodiment. In addition, the same reference number is attached | subjected to the component same as other embodiment, and the overlapping description is abbreviate | omitted. Moreover, it has the same structure and operation as the mask 180 shown so far except for the parts described below. The mask 180 has a drive unit 240 therein.

  The drive unit 240 deforms the pattern formation region 184 corresponding to different regions of the pattern formation region 184. That is, the driving unit 240 connects the plurality of driving elements 224 embedded in the mask blank forming the base of the mask 180, the driving lines 244 connected to the driving elements 224, and the driving lines 244 to the control unit 310. And a drive pad 246 to be a contact point in the case. The drive element 224 is supplied with a control signal from the control unit 310 via the drive pad 246 and the drive line 244, and deforms according to the supplied control signal.

  That is, the control unit 310 transmits a control signal to the driving unit 240 of the mask 180 and individually controls the driving unit 240 for each different region, thereby controlling the shape of the pattern formation region 184 for each different region. The control unit 310 varies the drive amount of the drive unit 240 for each different region in accordance with the distortion of the shot region 194 formed on the substrate 190.

  Thereby, each of the drive elements 224 displaces the pattern formation region 184 of the corresponding region. Note that a piezoelectric element, an electrostrictive element, or the like can be used as the driving element 224.

Here, the distance T ₁ from the driving element 224 to the pattern surface 182 is shorter than the distance T ₂ from the driving element 224 to the surface opposite to the pattern surface 182. Thereby, when the drive element 224 expands or contracts, the pattern surface 182 including the pattern formation region 184 is deformed.

  FIG. 10 is a cross-sectional view showing the structure of a mask 180 according to still another embodiment. In addition, the same reference number is attached | subjected to the component same as other embodiment, and the overlapping description is abbreviate | omitted. Moreover, it has the same structure and operation as the mask 180 shown in FIG.

  In the mask 180, the driving unit 240 includes a heating element 245 as the driving element 224. Each of the heating elements 245 is provided inside the mask blank, and the drive line 248 of the heating element 245 is exposed on the surface opposite to the pattern surface 182.

  With such a structure, it is possible to individually set the temperature of the heat generating element 245 by changing the drive current supplied to the heat generating element 245 via the drive line 248. Since the thermal expansion of the mask blank occurs around the heat generating element 245, the thickness of the mask blank changes and the pattern surface 182 can be deformed according to the supplied drive current.

Also in this embodiment, the distance T ₁ of the from the heater element 245 to the pattern surface 182 is shorter compared to the distance T ₂ of the up surface opposite to the pattern surface from the heater element 245. Thereby, the pattern surface 182 is mainly deformed when the mask blank is thermally expanded or contracted.

  In the present embodiment, a shape measuring device for measuring the shape of the pattern surface 182 of the mask 180 is provided, and it is verified whether the deformation is performed according to the correction position and the correction value calculated by the calculation unit 340. Also good. This shape measuring apparatus may also be used by the mask focus sensor described above.

  The use of the exposure apparatus 100 according to the embodiments described so far is not limited to the manufacture of micro devices such as semiconductor elements. For example, it can also be used to manufacture a display device such as a liquid crystal display element (LCD). In such a case, the exposure apparatus 100 transfers the device pattern formed on the glass substrate by the exposure apparatus 100.

  Further, as the exposure apparatus 100 of the present embodiment, the first pattern 186 of the mask 180 is transferred to the substrate 190 while the mask 180 and the substrate 190 are stationary, and the substrate 190 is sequentially moved stepwise. It may be a repeat type exposure apparatus.

  Further, in the manufacture of a thin film magnetic head or the like, it can also be used when a device pattern is transferred to the surface of a ceramic substrate. Furthermore, it can also be used for manufacturing an image sensor such as a CCD. Below, an example of the manufacturing process of the microdevice which may include the lithography process using the exposure apparatus 100 of embodiment of this invention is shown.

  FIG. 11 is a flowchart showing an example of a device manufacturing process including substrate processing. The “device” here includes a semiconductor chip such as an IC or LSI, a liquid crystal panel, a CCD, a thin film magnetic head, a micromachine, or the like.

  In step S601 (design step), specifications of a device to be manufactured are determined, and elements, circuits, and the like that can realize the specifications are designed. Also, the pattern of the mask 180 used when manufacturing the element and circuit is designed.

  Next, in step S602 (mask manufacturing step), a mask 180 (sometimes called a reticle) having a designed pattern is manufactured. On the other hand, in step S603 (substrate manufacturing step), a substrate 190 on which devices are formed is also manufactured. The substrate 190 may be a substrate formed of glass, ceramics, or the like in addition to a semiconductor substrate such as silicon.

  Subsequently, in step S604 (substrate processing step), substrate processing using the mask 180 prepared in step S602 is performed on the substrate prepared in step S603. The contents of the substrate processing will be described later with reference to FIG.

  In step S605 (device assembly step), device assembly is performed using the substrate 190 processed in step S604. This step S605 includes a dicing process, a bonding process, a packaging process (chip encapsulation), and the like for the substrate 190 as necessary.

  Finally, in step S606 (inspection step), tests such as operation confirmation and durability are performed on the device manufactured in step S605. Devices that pass the test through these series of steps are shipped.

  FIG. 12 is a flowchart showing an example of the substrate processing in step S604 shown in FIG. Each step from step S611 to step S614 is included in the pretreatment process in the substrate processing.

  First, in step S611 (oxidation step), the surface of the substrate 190 is uniformly oxidized. Next, in step S612 (CVD step), an insulating film is formed on the surface of the substrate 190 as necessary. Furthermore, in step S613 (electrode formation step), an electrode is formed on the surface of the substrate 190 by vapor deposition. Further, in step S614 (ion implantation step), ions are implanted into the substrate 190.

  In each of these steps, necessary processing is selected and executed according to the design of the target device. In some cases, the same step may be executed a plurality of times.

  When the pre-processing step is completed, the following post-processing step is executed. First, in step S615 (resist formation step), a photosensitive material is applied to the substrate to form a resist layer. Next, in step S616 (exposure step), the resist layer is exposed using the exposure apparatus 100. Further, in step S617 (development step), the exposed resist layer is developed. Thus, a mask layer to which the pattern of the mask 180 is transferred is formed on the substrate 190.

  Subsequently, in step S618 (etching step), since the opening pattern of the mask layer is exposed, the exposed member is removed by etching. Further, in step S619 (resist removal step), the resist device that is no longer needed is removed.

  By repeating the pretreatment process and the posttreatment process as described above, a multilayer structure is formed on the substrate. The formed structure forms an element or circuit.

  As described in detail above, the exposure pattern 187 formed by the mask 180 can be fitted to the second pattern 196 formed on the substrate 190 by using the mask holding unit 200 and the exposure apparatus 100 including the mask holding unit 200. Thus, a device having a multilayer structure can be manufactured with high yield. Exposure processing can be executed with high resolution utilizing the short wavelength of extreme ultraviolet rays. Therefore, it can be widely used in the field of utilizing lithography technology, such as the manufacture of semiconductor devices, as well as the manufacture of micromachines.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. In addition, it will be apparent to those skilled in the art that various modifications or improvements can be added to the above embodiment. Furthermore, it is apparent from the description of the scope of claims that the embodiments added with changes or improvements can be included in the technical scope of the present invention.

2 is a view schematically showing the structure of an optical system of the exposure apparatus 100. FIG. It is a figure which shows typically the exposure process by the mask 180. FIG. 2 is a block diagram schematically showing a control system 300. FIG. 4 is a cross-sectional view showing a structure of a mask holding unit 200. FIG. 5 is a perspective view showing the shape of a mask holding unit 200. FIG. It is a figure explaining operation of the mask 180 by the mask holding | maintenance part 200. FIG. It is a figure which shows typically the change of the projection pattern by operation of the mask 180. FIG. 1 is a diagram schematically showing the structure of an exposure system 500. FIG. It is sectional drawing which shows the structure of the mask 180 which concerns on other embodiment. It is sectional drawing which shows the structure of the mask 180 which concerns on other embodiment. It is a flowchart which shows an example of the manufacturing process of the device containing an exposure process. It is a flowchart which shows an example of the detailed process of an exposure process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Exposure apparatus, 110 Light source part, 112 Target nozzle, 114 Concave reflector, 120 Illumination optical system, 121, 126 Concave reflector, 122, 123 Fly eye reflector, 124 Optical integrator, 125 Convex reflector, 127 Plane reflector , 128 Movable light shielding blade, 129 Fixed light shielding blade, 130 Mask stage, 131 Base part, 132, 152 Stage part, 133, 137 Actuator, 154 Chuck part, 135 Support part, 140 Projection optical system, 141, 144 Concave reflector, 142 , 143 Convex reflector, 150 substrate stage, 160 chamber, 162 sealing window, 164 exhaust hole, 170 laser light source, 172 condenser lens, 180 mask, 181 region, 182 pattern surface, 184 pattern formation region, 186 First pattern, 187 exposure pattern, 190 substrate, 194 shot area, 196 second pattern, 200 mask holding part, 202, 204 illumination area, 210 base part, 220 elastic support part, 230, 240 driving part, 232 electrode, 234 244, 248 drive line, 245 heating element, 246 drive pad, 300 control system, 310 control unit, 312 demultiplexer, 330 alignment optical system, 340 calculation unit, 500 exposure system, 510 bus, 520 strain measurement device, 530 strain Trend calculation device, 540 storage device, 550 extraction device, 560 host

Claims (12)

A mask holding unit for holding a mask having a pattern surface on which a first pattern is formed;
A substrate holding unit for holding a substrate having a pattern region in which a second pattern is formed;
A pattern distortion measurement unit for measuring distortion of the pattern region or the second pattern of the substrate held by the substrate holding unit;
A control unit that controls the shape of the pattern surface of the mask based on information on the distortion of the pattern region or the second pattern measured by the pattern distortion measurement unit;
An exposure apparatus comprising: The control unit deforms the pattern surface;
The exposure apparatus according to claim 1. The mask holding unit holds the mask by electrostatically adsorbing a surface opposite to the pattern surface;
The control unit controls the suction force by which the mask holding unit electrostatically sucks the mask, and applies different forces to different areas of the pattern surface.
The exposure apparatus according to claim 2. The mask has a drive unit that deforms the pattern surface corresponding to different regions of the pattern surface,
The control unit controls the shape of the pattern surface for each different region by transmitting a control signal to the driving unit of the mask and individually controlling the driving unit for each different region.
The exposure apparatus according to claim 2. A storage device for storing information related to the distortion of the pattern region or the second pattern measured by the pattern distortion measurement unit;
The control unit controls the shape of the pattern surface based on information on the distortion stored in the storage device.
The exposure apparatus according to any one of claims 1 to 4. An alignment mark detector that detects the positions of a plurality of alignment marks formed on the substrate;
A correction value calculation unit that calculates a correction value related to the distortion based on the positions of the plurality of alignment marks measured by the alignment mark detection unit;
The storage device stores the correction value calculated by the correction value calculator.
The exposure apparatus according to claim 5. The mask is a reflective mask;
An illumination optical system for illuminating the reflective mask;
An exposure beam reflected by the pattern formed on the reflective mask is guided to the substrate, and the projection optical system is non-telecentric on the reflective mask side,
The exposure apparatus according to claim 1, wherein the first pattern on the pattern surface, the shape of which is controlled by the control unit, is projected onto the substrate via the projection optical system. A mask holding unit for holding a mask having a pattern surface on which a first pattern is formed;
A substrate holding part for holding a substrate on which a pattern region having a second pattern is formed;
An exposure apparatus comprising a control unit that controls the shape of the pattern surface of the mask;
A strain measuring device for measuring the strain of the pattern region or the second pattern of the substrate;
An exposure system comprising: a control device that controls the shape of the pattern surface of the mask held by the mask holding unit based on information on the distortion measured by the distortion measuring device. A plurality of the exposure apparatus;
The exposure system according to claim 8, wherein the distortion measurement device measures distortion of the pattern region or the second pattern formed in the plurality of exposure apparatuses. From information on the distortion measured by the distortion measuring apparatus, a distortion tendency calculating apparatus that calculates a distortion tendency for each exposure apparatus;
A storage device for storing information on the distortion for each substrate and the distortion tendency for each exposure apparatus;
An extraction device that extracts from the storage device an exposure device that matches the distortion of the pattern region or the second pattern formed on the substrate among the plurality of exposure devices;
An exposure system according to claim 9. Each of the control units of the exposure apparatus controls the shape of each of the pattern surfaces so as to correct distortion inherent in each of the exposure apparatuses.
The exposure system according to claim 10. Providing a mask having a pattern surface on which a first pattern is formed;
Providing a substrate on which a pattern region having a second pattern is formed;
Measuring distortion of the pattern area or the second pattern of the substrate;
Controlling the shape of the pattern surface of the mask in accordance with the distortion of the pattern region or the second pattern;
Exposing the first pattern on the second pattern formed in the pattern region of the substrate in a state in which the shape of the pattern surface is controlled;
A device manufacturing method comprising:

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