JPH1097967A - Mask structure, mask holding method, and manufacture of device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately correct the scale factor, etc., of a mask pattern through a simple procedure. SOLUTION: A mask supporting body 120 is provided with a front-surface chuck 121 and rear-surface chuck 122 which respectively suck the front surface and rear surface of the supporting frame 114 of an X-ray mask structure 110 by suction. The supporting body 120 is provided with pressure adjusting mechanisms which can respectively adjust the sucking pressures of the chucks 121 and 122 so as to correct the scale factor of an X-ray mask through the deformation of the supporting frame 114.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for correcting the shape of a mask used in a semiconductor exposure apparatus using radiation such as X-rays.

[0002]

2. Description of the Related Art In recent years, circuit patterns have been miniaturized in order to improve the degree of integration and operation speed of semiconductor devices such as LSIs. In circuit pattern formation in the process of manufacturing these LSIs, attention has been paid to formation of a fine pattern by a lithography technique using high-brightness X-rays from a synchrotron ring (SR) or the like. As one of the prominent methods of the X-ray exposure, there is a method in which a mask and a wafer are arranged close to each other and irradiated with X-rays to perform the same-size exposure transfer. In this method, it is difficult to adjust the transfer magnification of the mask pattern transferred to the wafer because the mask and the wafer are transferred in close proximity to each other, so that it is difficult to adjust the transfer magnification. Japanese Patent Publication No. 66095 proposes a method of controlling the pattern magnification on the membrane by positively deforming the mask substrate by applying an in-plane stress or an out-of-plane stress to the mask substrate from the outside by a pressing mechanism. In this method, the amount of displacement required for the mask structure is determined from a signal obtained by measuring the alignment between the mask and the wafer immediately before the exposure operation, and the mask pattern is corrected for magnification by pressing with a corresponding force. is there.

[0003]

SUMMARY OF THE INVENTION The present invention has been made to further improve the technique of the above-mentioned conventional example, and is intended to correct a mask shape (magnification, etc.) with high accuracy while using a simple method. It is an object of the present invention to provide a mask structure, a mask holding method, and a device production method that enable the mask structure.

[0004]

One aspect of the mask holding method of the present invention that achieves the above object is to hold the front and back surfaces of a support frame of a mask structure by vacuum suction. is there. Here, it is further preferable that the mask pattern is corrected by individually adjusting the vacuum suction force of the front surface and the back surface.

[0005] One form of the mask structure of the present invention is a mask structure comprising a membrane on which a pattern is formed, a rectangular sub-frame for supporting the membrane, and a support frame for holding the sub-frame. And
The sub-frame is held so as to be capable of minute rotation with respect to one point of the support frame.

In order to hold the mask structure, it is more preferable to fix and support the support frame and correct the mask pattern by pressing the rectangular sub-frame from two directions.

Another form of the mask structure of the present invention is a mask structure comprising a mask substrate having a membrane on which a pattern is formed, and a support frame for supporting the mask substrate. Is characterized in that a plurality of grooves are formed in parallel outside the rectangular outer edge of the membrane. Here, for example, the four grooves are formed around the square, and an elastic hinge mechanism is formed at the intersection of each groove.

Another form of the mask structure of the present invention is a mask structure comprising a mask substrate having a membrane on which a pattern is formed, and a support frame for supporting the mask substrate. It is characterized by being provided.

In order to hold the mask structure, it is more preferable that the mask pattern is corrected by controlling the force for pressing the support frame in accordance with the output of the distortion detecting means.

The above mask structure is, for example, a mask for X-ray exposure.

One embodiment of the device production method according to the present invention is characterized in that a device is produced by using any one of the mask structures or the mask holding method described above.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An X-ray mask holding means according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a partial cross-sectional view of an X-ray mask holding means according to a first embodiment of the present invention.
1 is a mask pattern, 112 is a membrane, 113 is a support substrate, 114 is a support frame, 120 is a support, 12
1 is a front chuck, 122 is a back chuck, 123, 1
24 is a suction groove, 125 and 126 are abutting portions, 127,
128 is a suction line.

The mask pattern 111 is made of an X-ray absorber film, particularly a material having a high X-ray absorptivity such as W, Ta or its alloy, and the membrane (X-ray transmission film) 112 is made of Si.
It is made of C, SiN or the like and supports the mask pattern 111. The support substrate 113 is made of a Si wafer and supports the mask pattern 111 and the membrane 112. The support substrate 113 is bonded to the support frame 114 for reinforcing the support substrate 113 with an adhesive or the like. The support frame 114 is made of Pyrex glass having a coefficient of linear expansion close to that of Si, or SiC ceramics having high rigidity.

The mask pattern surface of the support substrate 113 having a SiN or SiC film formed on the front surface is removed by about 30 to 60 mm from the back surface by etching to provide an opening for X-rays as a light source and to provide a SiN or SiC film. Is formed. An X-ray absorber, for example, a metal such as W or Ta is patterned on the membrane 112 to form a mask pattern 111.

Surface chuck 1 provided on support 120
21 is a chuck for sucking the front surface (the wafer side) of the X-ray mask structure 110 of the present invention,
A chuck for sucking the back surface (light source side) of the line mask structure 110. The suction grooves 123 and 124 are formed in the front surface chuck 121 and the back surface chuck 122 in an annular shape, respectively. Abutting portion 12 provided on front surface chuck 121 and back surface chuck 122 with suction grooves 123 and 124 interposed therebetween.
5, 126 are processed with high precision to prevent suction leakage when the support frame 114 of the X-ray mask structure 110 is fixed. Naturally, the portion of the support frame 114 that abuts on the chuck is similarly planarized with high precision.

A magnification change mode using the X-ray mask holding means according to the first embodiment of the present invention will be described with reference to FIG. FIG. 2 is a partially enlarged cross-sectional view of the chuck portion of FIG. 1, and FIG.
(B) shows a state where the suction groove of the surface chuck is sucked.

When the air in the suction groove 124 of the back surface chuck 122 is sucked by a vacuum pump (not shown) to reduce the pressure while the X-ray mask structure is mounted on the exposure apparatus, the support frame 1
14 is concavely deformed toward the surface chuck as shown in FIG. With the deformation, the mask substrate 113 is deformed toward the outer surface side, and the mask pattern 11 on the membrane 112 is deformed.
1 is expanded. At this time, the suction force of the surface chuck 121 is 0FF. Further, air in the suction groove 123 of the surface chuck 121 or a gas of an exposure atmosphere (such as He).
When the pressure is reduced by suction using a vacuum pump (not shown), the support frame 114 is deformed in a convex shape toward the surface chuck as shown in FIG. With the deformation, the mask substrate 113 is deformed to the out-of-plane back side, and the mask pattern 111 on the membrane 112 is reduced. At this time, the back chuck 122
Has a suction force of 0FF.

The thinner the edge of the support frame 114 of the X-ray mask structure 110 is, the higher the flexibility becomes, and a large magnification correction amount can be obtained with a low suction force. In addition, the larger the area of the suction unit, the larger the magnification correction amount can be obtained with a lower suction force.

Next, a state in which this mechanism is incorporated in an exposure apparatus will be described. FIG. 3 is a schematic view showing a state in which the X-ray mask holding means according to the first embodiment of the present invention is incorporated in an exposure apparatus.
Is a support frame, 321 is a front chuck, 322 is a back chuck, 331 is a wafer, 332 is a wafer chuck, 333 is a wafer stage, 334 is an alignment optical measurement device, 336 is a magnification correction control device, 337 is a vacuum pump, 338 is vacuum It is a gauge.

As in FIG. 1, the support frame 314 of the X-ray mask structure is fixed so as to be sandwiched between the back chuck 321 and the front chuck 322. The alignment optical system measuring device 334 sets the proximity of the mask pattern 311 and the wafer 3 at the set proximity gap.
Alignment of an alignment mark (not shown) drawn on 31 is performed. The wafer 331 is fixed to a wafer stage 333 by a wafer chuck 332. The measurement result of the alignment optical measurement device 334 is input to the magnification correction control device 336.

The magnification of the mask pattern and the pattern on the wafer are measured by using an alignment optical measuring device for two or more alignment marks, and the distance (magnification) between the alignment marks is measured. The magnification change between the mask pattern and the pattern on the wafer is compared. If the mask pattern is smaller than the pattern on the wafer, the backside chuck 32 is used.
2 to increase the suction force to enlarge the mask pattern. Also,
When the mask pattern is larger than the pattern on the wafer, the suction force of the surface chuck 321 is increased to reduce the mask pattern. Vacuum gauge 33
8 (Gl, G2) and vacuum pump 337 (P
1, P2), and are managed and controlled by the magnification correction control device 336. With this control system, the magnification of the mask pattern and the pattern on the wafer are controlled by deforming the X-ray mask structure out of plane.

With the above mechanism, the mask deformation for correcting the mask magnification is performed by changing the suction force of the chuck portion, so that a complicated drive mechanism as in the prior art is not required.

Next, a second embodiment of the present invention will be described with reference to the drawings. 4A and 4B are explanatory views of an X-ray mask holding means according to a second embodiment of the present invention, wherein FIG. 4A is a schematic top view, FIG. 4B is a schematic cross-sectional view, and FIG. FIG. In the figure, reference numeral 410 denotes an X-ray mask structure,
12 is a membrane, 413 is a support substrate, 414 is a base frame, 415 is a subframe, 416 is a transmission component,
417 and 418 are pins.

The mask pattern of the X-ray mask used in the present embodiment is formed in advance in the pattern forming step so as to be slightly larger than an ideal mask pattern size. The pattern magnification offset at this time is
It is determined from the process distortion assumed in the wafer process after transfer.

Subframe 4 which is a feature of the present embodiment
Reference numeral 15 denotes a rectangular support frame having a frame shape. The material of the sub-frame 415 is preferably higher in rigidity than the material of the support substrate 413. For example, in the present embodiment, SiC or the like is used. The sub-frame 415 is bonded and fixed to the outer peripheral portion of a back-etched portion for forming the membrane 412 of the support substrate 413. At this time, as a procedure for forming the X-ray mask structure 410, if the support substrate 413 and the sub-frame 415 are bonded and fixed before the back etch step of the support substrate 413, the warp of the support substrate 413 due to the membrane stress after the back etch is obtained. Can be prevented. Further, after the support substrate 413 is cut into the same shape as the subframe 415 in advance and is fixed to the subframe 415, back etching may be performed.

With such a mask substrate shape,
This is also effective in preventing contact between the X-ray mask and the wafer substrate derived from the tilt (tilt) between the X-ray mask and the wafer substrate in close-to-uniform exposure.

The base frame 414 is a subframe 41
As in the case of No. 5, in this embodiment, SiC or the like is used as a material having high rigidity. In the present embodiment, the base frame 414 has a circular shape, and the sub-frame 415 and the base frame 414 are fastened and fixed at one point of the pin 418 so that the contact surfaces are substantially in close contact.

The transmission component 416 transmits the driving force from the magnification correcting mechanism on the support on the X-ray exposure apparatus side to the sub-frame 41.
5 to the support substrate 413. Transmission component 416
Is attached to the base frame 414 via pins 417 so as to be finely movable. At this time, the transmission component 416 transmits an external force to the sub-frame 415. For example, in the present embodiment, the transmission component 416 is movable in the external force direction by supporting between the pin 417 and the transmission component 416 with an elastic component (a leaf spring or the like). It has become. In the present embodiment, the sub-frame 415 is stopped via the pin 417 and the leaf spring.
Other methods are acceptable. The transmitting part 416 has a corresponding part for contact protruding so as to press two corners of the beam of the rectangular support frame of the sub-frame 415.

By using the above-described method of attaching the transmission component 416, the external force from one location can be evenly distributed to the sub-frame 41.
5 can be operated at two corners. Further, since the external force acting on the sub-frame 415 is composed of two orthogonal axes, the transmission components 416 are arranged on the base frame 414 in two orthogonal sets. Although the sub-frame 415 and the transmission component 416 are in contact with each other, but are not fastened, the degree of freedom in the direction perpendicular to the direction in which the force acts is ensured by the sliding between the sub-frame 415 and the transmission component 416. The orthogonal external forces acting on the sub-frame 415 can be applied to the sub-frame 41 without
5 can be transmitted.

Next, an exposure procedure when the above-mentioned X-ray mask holding means is used will be described. FIG. 5 is a schematic perspective view showing an exposure procedure of the X-ray exposure apparatus. Reference numeral 410 denotes an X-ray mask structure, 431 denotes a wafer, and 441 denotes a storage ring (S).
R) and 442 are X-ray mirrors and 443 is a shutter.

The high-brightness X-rays emitted from the storage ring (SR) 441 are reflected by an X-ray mirror 442 which is a total reflection mirror.
Is enlarged and projected on an X-ray exposure apparatus. Exposure amount control during transfer is performed by a shutter 443. The X-rays that have passed through the shutter 443 further pass through the X-ray mask on the X-ray mask structure 410 and are patterned on the resist on the wafer 431.

FIG. 6 is a schematic top view of an X-ray mask holding means according to a second embodiment used in the above-mentioned X-ray exposure apparatus. Reference numeral 410 denotes an X-ray mask structure, 420 denotes a support, 423 is an actuator, and 424 is a positioning pin.

The X-ray mask structure 410 includes a support 420.
Is transported and installed by an X-ray mask transport mechanism (not shown). In the present embodiment, the positioning of the mask on the support 420 is performed by two positioning members. In the X-ray mask structure 410 shown in FIG. 6, a notch for positioning is provided on the base frame 414 (FIG. 4).
In the present embodiment, a vacuum chuck method is used as a method for holding the X-ray mask structure 410 after positioning, but a mechanical chuck or a magnetic chuck may be used.

The actuator 423 is for correcting magnification, and the X-ray mask structure 410 held on the support 420 is provided.
And two sets thereof are orthogonally arranged on the support body 420 so as to act on the transmission component 416 of the first embodiment. As the actuator 423 used in the present embodiment, an actuator using an air cylinder as a driving source is used. Since the pressure applied to the air cylinder becomes the driving force of the actuator 423, X
The pattern magnification control of the line mask structure 410 is performed by controlling the driving pressure, but other driving control methods may be used. Also, the transmission component 41 of the actuator 423
When the X-ray mask structure 410 is mounted, the tip portion that comes into contact with 6 is retracted so as not to hinder mask transport.

The X-ray mask structure 410 mounted and held on the support 420 detects the amount of deviation from the positioning mark of the wafer 431 to be transferred before exposure and transfer by a mask alignment system (not shown). At this time, a pattern size of the X-ray mask structure 410 and a transfer magnification correction value which is a distortion of a pattern to be transferred to the wafer 431 are obtained by statistical processing of the shift amount or the like. Based on the measured value, each of the orthogonal actuators 423 is operated to control the pressure applied to each of the transmission components 416 of the X-ray mask structure 410. This pressing force presses the beam portion of the sub-frame 415, and as a result, the sub-frame 415 is isotropically compressed and deformed, and therefore, the support substrate 413 bonded and fixed to the sub-frame 415.
Is also compressed isotropically. At this time, a method of controlling the pressure of the actuator 423 while observing the alignment mark may be used. Further, if the pressing force and the pattern shrinkage applied to the X-ray mask structure 410 are measured in advance for each X-ray mask and the pressure is controlled based on the data, the operation time required for the magnification correction can be further reduced. .

The feature of the X-ray mask holding means of the present embodiment is that it utilizes a minute elastic deformation of the rectangular support frame, in other words, has a structure equivalent to the arrangement of uniform compression springs on four sides. By compressing the four corners, the compression spring is linearly deformed to realize uniform compression deformation.

As described above, in the present embodiment, the X-ray mask pattern to be transferred changes the pressing force applied to two orthogonal points on the support substrate 413 to change the transfer pattern to the exposure size on the wafer 431 side. The X-ray mask holding means can be simplified. Note that the mask pattern of the X-ray mask used in the present embodiment is subjected to isometric compression to perform pattern magnification control.
As described above, when creating a pattern, it is necessary to previously form a large pattern size.

Further, if the X-ray mask holding means of this embodiment is used in an X-ray exposure apparatus having an exposure transfer magnification correcting mechanism for applying an in-plane stress to the X-ray mask, two points orthogonal to the X-ray mask can be obtained. The magnification control mechanism that presses can easily perform variable control of the isotropic magnification, which was difficult in the past, and the magnification correction mechanism in the X-ray exposure apparatus can be configured with a simple mechanism. A device manufacturing apparatus having an exposure apparatus can efficiently produce a highly accurate semiconductor device.

Next, a third embodiment will be described with reference to the drawings. FIG. 7 shows X in the third embodiment of the present invention.
FIG. 3 is an explanatory diagram of an X-ray mask structure of a line mask holding unit,
(A) is a schematic top view, (b) is a schematic sectional view.
In the figure, reference numeral 712 denotes a membrane, 713 denotes a support substrate, 71
4 is a support frame, 716 is a first groove, 717 is a second groove, 718 is an elastic hinge, and 719 is an adhesive fixing portion.

The description of the names of the parts common to the second embodiment is omitted. In this embodiment, the support substrate 713 which is a feature of the third embodiment is the same as the second embodiment.
In this embodiment, the sub-frame 415 and the transmission component 416 described in the above embodiment are formed in a support substrate 413. The support substrate 713 is, as shown in FIG.
A first groove 716 for stress relaxation is formed by using a process such as etching so as to surround the two portions.
2 is processed so as to be supported by a part of the rectangular frame-shaped support substrate 713. Next, second grooves 717 are formed in three corners of the rectangular frame, and the rectangular frame surrounding the membrane 712 and the supporting substrate 71 are formed.
An elastic hinge 718 connecting the outer peripheral portion of the support 3 at three corners is formed by a part of the support substrate.

The elastic hinge 718 has a stiffness in a direction perpendicular to the bending direction that is much larger than the stiffness in the bending direction. The support substrate 713 and the support frame 7
14 is adhesively fixed by an adhesive fixing portion 719 on the outer peripheral portion of the support substrate 713 sandwiching a corner where the second groove 717 shown by oblique lines in FIG. 7A is not cut.

In this embodiment, the external force acting on the membrane 712 for adjusting the magnification is directly applied to the support substrate 7.
13 is transmitted from directions A and B shown in FIG.
External forces from the A and B directions act on the support substrate 713 formed in a rectangular frame shape inside the groove 716 of the support substrate 713 via the elastic hinge 718. The configuration of the elastic hinge 718 having the above-described bending rigidity shown in FIG.
External force from the first groove portion 7 without interfering with each other.
16 and consequently the membrane 712
The upper mask pattern is isotropically compressed and deformed. Therefore, in this embodiment, the sub-frame 415 (square support frame) described in the second embodiment is formed in the support substrate 413. At this time, the pressing force due to external force transmission is
If it can be applied to the peripheral portion of the support substrate 713 corresponding to the central portion of the beam formed in the shape of the rectangular support frame of the support substrate 713, the transmission of the external force can be efficiently transmitted to the beam portion.

In this embodiment, the sub-frame 415 and the transmission component 4 are provided on the support substrate 413 of the second embodiment.
By combining the functions of the sixteen functions, the manufacture and assembly of the X-ray mask can be simplified, and an inexpensive X-ray mask with a magnification correction function can be provided. Next, a fourth embodiment will be described with reference to the drawings. FIGS. 8A and 8B are explanatory views of an X-ray mask holding means provided with a strain gauge according to the fourth embodiment of the present invention, wherein FIG. 8A is a schematic top view, and FIG. 8B is a schematic sectional view. In the figure, reference numeral 810 denotes an X-ray mask structure,
12 is a membrane, 813 is a support substrate, 814 is a support frame, 816 is a strain gauge, 817 is an electrode, and 818 is a signal pattern.

The support frame 814 to which the support substrate 813 is fixed is circular in the present embodiment, and the center of the circle substantially coincides with the center of the exposure angle of view. Support frame 8
A magnetic material (not shown) is embedded in the substrate 14 and is supported by the exposure apparatus by being magnetically attracted by a magnet provided on the support side.

The strain gauge 816 is provided on the back surface of the support substrate 813 and detects a distortion of the support substrate 813. The detected signal is extracted to the outside via the signal line pattern 818 and the electrode 817. Four strain gauges 816 are arranged along four outer sides of the back-etched region for forming the membrane 812 on the back surface of the support substrate 813. 8 (a) detects distortion in the X direction, and two on the left and right detect distortion in the Y direction. The two ends of the strain gauge 816 are connected to the electrode 817 through the signal pattern 818. The signal transmitted through the electrode 817 allows an external strain gauge control unit to measure the measured value of the strain gauge 816. Electrode 817
And the signal pattern 818 is a pattern made of an electric conductor.

FIG. 9 is a configuration diagram of a magnification correcting apparatus using the X-ray mask structure of FIG. 8, and FIG. 10 is a sectional view showing a state where the X-ray mask structure of FIG. 8 is fixed to a support. is there. In the figure, reference numeral 810 denotes an X-ray mask structure, 812 denotes a membrane, 813 denotes a support substrate, 814 denotes a support frame, 8
16 is a strain gauge, 817 is an electrode, 818 is a signal pattern, 819 is a support-side electrode, 820 is a support, 823 is an actuator, 824 is a positioning pin, 825 is a support portion, 826 is an electrostrictive element, and 827 is an abutting portion. 828, an electromagnet, 831 a strain gauge control unit, 832 a central processing unit, and 833 a magnification correction control unit.

The X-ray mask structure 810 is magnetically chucked to the support 820 with the side of the support frame 814 abutting the positioning pins 824. An electromagnet 828 is embedded in the support 820, and attracts the mask support frame by magnetism. In a part of the suction surface, a support-side electrode 819 is provided in the same position as the electrode 817 of the X-ray mask structure 810 in a sucked state, and a signal of the strain gauge 816 is transmitted to an external strain gauge controller 831. Connected with.

The magnification correcting mechanism performs correction by pressing the support frame 814 in an in-plane direction with the actuator 823. The actuator 823 includes a support portion 825,
It comprises an electrostrictive element 826 and an abutting part 827. The electrostrictive element 826 extends in response to a command signal from the magnification correction control unit 833, and presses the support frame 814 by the abutting unit 827. The actuator 823 is disposed at a position facing the positioning pin 824, and is positioned in a direction in which a force is generated toward the center of the mask. By controlling these two actuators 823 with their respective forces, it is possible to separately control the distortion in the X and Y directions.

In response to a signal from a strain gauge 816 installed on the X-ray mask structure 810, the strain gauge control unit 83
1, the distortion is measured and the amount of distortion is
32. The central processing unit 832 issues a command to the magnification correction control unit 833 so that the distortion becomes a desired value, and the magnification correction control unit 833 drives the actuator 823, and X
The line mask structure 810 is distorted.

Next, the procedure of exposure using the X-ray mask structure 810 and an exposure apparatus equipped with a magnification correction mechanism will be described. The X-ray mask structure 810 supports the support 82.
Loaded at 0 and supported. Next, a wafer to be transferred is loaded, and global alignment is performed. In global alignment, alignment is performed for a part of the shots in the wafer, and rotation, displacement, magnification, and the like of the entire wafer can be obtained. The magnification in the measurement result is corrected by the above-described magnification correcting means. The magnification correction amount is based on the measurement result of the strain gauge 816 installed on the X-ray mask structure 810. While correcting the mask, the wafer is moved to the first shot position to perform exposure. After the exposure, the wafer is moved to the next exposure position, and the entire wafer is sequentially exposed.

Since the measurement of the strain gauge is independent of the driving of the wafer stage, the driving of the wafer stage and the driving of magnification correction can be performed in parallel.
Thus, exposure can be performed without lowering the throughput.

Next, a fifth embodiment will be described with reference to the drawings. FIGS. 11A and 11B are explanatory diagrams of an X-ray mask holding means provided with a strain gauge according to a fifth embodiment of the present invention, wherein FIG. 11A is a schematic top view, and FIG. 11B is a block diagram. In the figure, reference numeral 1110 denotes an X-ray mask structure, 1112
Reference numeral 1113 denotes a support substrate, 1114 denotes a support frame, 1116 denotes a strain gauge, 1124 denotes a positioning pin, 1131 denotes a strain gauge control unit, 1132 denotes a central processing unit, 1133 denotes other peripheral devices, and 1136 denotes mask transfer means.

The structure of the X-ray mask structure 1110 is shown in FIG.
Is the same as Similarly to the chucking of the fourth embodiment, the signal of the strain gauge 1116 is taken out similarly to the configuration shown in FIG. Here, since the configuration is the same as that of the fourth embodiment, the description is omitted.

This embodiment will be described with reference to FIG. The X-ray mask structure 1110 is taken out of a mask holder (not shown) by the mask transport means 1136 and transported to a mask support. Mask transfer means 1
With 136, the X-ray mask structure 1110 is abutted against the positioning pin 1124 to be positioned, and is attracted by the magnetism of the electromagnet. Thereafter, the strain of the mask is measured by the strain gauge 1116. Strain gauge control unit 11
31 calculates the amount of distortion and sends the value to the central processing unit 1132. The central processing unit 1132 determines whether or not the value of the distortion is within a range of a predetermined value. If the measured amount of distortion is within a specified value, exposure is performed. If the measured distortion is out of the range, it means that the X-ray mask structure 1110 has been distorted by chucking. Therefore, the central processing unit 1132 sends a command to the mask transport system, and performs the chucking operation again. Then, the distortion is set to be within a specified value. If the distortion does not become less than the specified value even after performing the chucking operation again, the central processing unit 1132 outputs an error to notify that an abnormality has occurred in the mask itself.

If there is distortion, the original circuit pattern will be displaced, the overlay accuracy will be reduced, and the device yield will be reduced. In the present embodiment, the strain gauge 1
Using the X-ray mask structure 1110 provided with 116,
By monitoring the distortion at the time of chucking, if a distortion equal to or more than a specified value occurs, the chucking is performed again to avoid a decrease in yield due to pattern distortion. Further, it is possible to prevent exposure from being performed while distortion is generated.

In this case, an output of a strain gauge when a circuit pattern is drawn on a mask or the like is used as a specified value serving as a reference for distortion. This is because the state in which the circuit is drawn can be maintained.

In this embodiment, the mask chucking of the exposure apparatus has been described. However, it is needless to say that the present invention can be similarly applied to a chucking mechanism such as an EB drawing apparatus and a substrate of a dimension measuring machine.

FIG. 12 shows a production flow of a semiconductor device (a semiconductor chip such as an IC or an LSI, or a liquid crystal panel or a CCD) using the mask structure. In step 1 (circuit design), the circuit of the semiconductor device is designed.
Step 2 is a process for making a mask on the basis of the circuit pattern design. In step 3 (wafer manufacture), a wafer is manufactured using a material such as silicon. Step 4 (wafer process) is called a preprocess, and an actual circuit is formed on the wafer by lithography using the prepared mask and wafer.
Step 5 (assembly) is called a post-process, and is a process of forming a semiconductor chip using the wafer produced in step 4, and includes processes such as an assembly process (dicing and bonding) and a packaging process (chip encapsulation). . In step 6 (inspection), inspections such as an operation confirmation test and a durability test of the semiconductor device manufactured in step 5 are performed. Through these steps, a semiconductor device is completed and shipped (step 7).

FIG. 13 shows a detailed flow of the wafer process. Step 11 (oxidation) oxidizes the upper surface of the wafer. Step 12 (CVD) forms an insulating film on the wafer surface. Step 13 (electrode formation) forms electrodes on the wafer by vapor deposition. Step 14
In (ion implantation), ions are implanted into a wafer. In step 15 (resist processing), a photosensitive agent is applied to the wafer. Step 16 is an exposure process for printing, by exposure, the mask circuit pattern on the wafer. Step 17 (development) develops the exposed wafer. In step 18 (etching), portions other than the developed resist image are removed. In step 19 (resist stripping), unnecessary resist after etching is removed. By repeating these steps, multiple circuit patterns are formed on the wafer.

[0060]

According to the present invention, the correction of the transfer magnification of the mask pattern and the like can be performed with high accuracy while having a simple structure. Utilizing this makes it possible to produce devices with higher precision than ever before.

[Brief description of the drawings]

FIG. 1 is a partial sectional view of an X-ray mask holding means according to a first embodiment of the present invention.

FIG. 2 is a partially enlarged cross-sectional view of a chuck unit of FIG.
(A) is a state where the suction groove of the back surface chuck is sucked.
(B) shows a state where the suction groove of the surface chuck is sucked.

FIG. 3 is a schematic diagram illustrating a state in which the X-ray mask holding unit according to the first embodiment of the present invention is incorporated in an exposure apparatus.

FIG. 4 is an explanatory diagram of an X-ray mask holding unit according to a second embodiment of the present invention. (A) is a schematic top view.
(B) is a schematic sectional view. (C) is a schematic perspective view.

FIG. 5 is a schematic perspective view showing an exposure procedure of the X-ray exposure apparatus.

FIG. 6 is a schematic top view of an X-ray mask holding unit according to a second embodiment used in the above-described X-ray exposure apparatus.

FIG. 7 is an explanatory diagram of an X-ray mask structure of an X-ray mask holding unit according to a third embodiment of the present invention. (A) is a schematic top view. (B) is a schematic sectional view.

FIG. 8 is an explanatory view of an X-ray mask holding means provided with a strain gauge according to a fourth embodiment of the present invention. (A) is a schematic top view. (B) is a schematic sectional view.

9 is a configuration diagram of a magnification correction device using the X-ray mask structure of FIG.

FIG. 10 is a cross-sectional view showing a state where the X-ray mask structure of FIG. 8 is fixed to a support.

FIG. 11 is an explanatory view of an X-ray mask holding means provided with a strain gauge according to a fifth embodiment of the present invention. (A) is a schematic top view. (B) is a block diagram.

FIG. 12 is a flowchart illustrating a production flow of a semiconductor device.

FIG. 13 is a flowchart showing a detailed flow of a wafer process.

[Explanation of symbols]

110, 410, 810, 1110 X-ray mask structure 111, 311 Mask pattern 112, 412, 712, 812, 1112 Membrane 113, 413, 713, 813, 1113 Support substrate 114, 314, 414, 714, 814, 1114
Support frame 120, 420, 820 Support body 121, 321 Surface chuck 122, 322 Backside chuck 123, 124 Suction groove 125, 126 Abutment part 127, 128 Suction line 331, 431 Wafer 332 Wafer chuck 333 Wafer stage 334 Alignment optical measurement Device 336 Magnification correction control device 337 Vacuum pump 338 Vacuum gauge 415 Subframe 416 Transmission component 417, 418 Pin 423, 823, Actuator 424, 824, 1124 Positioning pin 441 Storage ring (SR) 442 X-ray mirror 443 Shutter 716 First Groove 717 Second groove 718 Elastic hinge 719 Adhesive fixing portion 816, 1116 Strain gauge 817 Electrode 818 Signal pattern 819 Supporting-side electrode 825 Supporting portion 826 Electrostrictive element 827 Abutment section 828 Electromagnet 831, 1131 Strain gauge control section 832, 1132 Central processing unit 833 Magnification correction control section 1133 Other peripheral equipment 1136 Mask transport means

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yuji Chiba 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc.

Claims (10)

[Claims] 1. A method for holding a mask, comprising holding the front and back surfaces of a support frame of a mask structure by vacuum suction. 2. The mask holding method according to claim 1, wherein the mask pattern is corrected by individually adjusting the vacuum suction force of the front surface and the back surface. 3. A mask structure comprising a membrane on which a pattern is formed, a rectangular sub-frame for supporting the membrane, and a support frame for holding the sub-frame, wherein the sub-frame is a support frame. Characterized in that the mask structure is held so as to be able to rotate minutely with respect to one point. 4. The method for holding a mask structure according to claim 3, wherein the supporting frame is fixedly supported, and the mask pattern is corrected by pressing the rectangular sub-frame from two directions. Mask holding method. 5. A mask structure comprising: a mask substrate having a pattern-formed membrane; and a support frame for supporting the mask substrate, wherein the mask substrate has an outer periphery of a rectangular outer edge of the membrane. A plurality of grooves are formed in parallel with the mask structure. 6. The mask structure according to claim 5, wherein four said grooves are formed around said square, and an elastic hinge mechanism is formed at an intersection of each groove. 7. A mask structure comprising a mask substrate having a membrane on which a pattern is formed, and a support frame for supporting the mask substrate, wherein the mask structure is provided with a strain detecting means. Structure. 8. The method for holding a mask structure according to claim 7, wherein a mask pattern is corrected by controlling a force pressing the support frame in accordance with an output of the distortion detecting means. Mask holding method. 9. The mask structure or the mask holding method according to claim 1, wherein the mask structure is a mask for X-ray exposure. 10. A device production method using the mask structure or the mask holding method according to claim 1.