JP2002049145A - Mask protector, method for producing the same, mask and exposure system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mask protector which suppresses the deflection of a pellicle and can prevent the lowering of optical characteristics caused by the deflection of the pellicle and to provide a method for producing the mask protector. SOLUTION: Films TSF and CSF having such a stress as to correct the deflection of a pellicle PE are formed on the surface of the pellicle PE.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mask protection device for protecting a mask used for manufacturing a device such as a semiconductor device, a liquid crystal display device, an image pickup device (such as a CCD) or a magnetic head, and this mask. The present invention relates to a method of manufacturing a protection device, a mask including the mask protection device, and an exposure device.

[0002]

2. Description of the Related Art In a photographic process for manufacturing a device, an image of a circuit pattern formed on a mask (or reticle) is transferred to a resist layer on a photosensitive substrate via an optical system of an exposure apparatus. The mask is generally provided with a mask protection device for preventing foreign matter such as dust from adhering to the pattern region. The mask protection device includes a frame (pellicle frame) provided around the pattern region, And a pellicle which is stretched over the pellicle frame so as to cover the pattern area. As the pellicle, a transparent thin film-shaped member mainly containing an organic substance such as nitrocellulose and having a thickness of about several hundred nm to several μm has been used.

[0003]

Incidentally, in the exposure apparatus, the exposure wavelength tends to shift to a shorter wavelength side in recent years in order to cope with miniaturization of circuit patterns. In other words, a KrF excimer laser (248 nm), ArF
A light source having a short wavelength such as an excimer laser (193 nm) has come to be used, and an exposure apparatus using an F ₂ laser (157 nm) having a shorter wavelength is in the stage of being put into practical use.

The above-mentioned organic substances such as nitrocellulose are:
Energy absorption for a light beam in the vacuum ultraviolet region of about 120 to 200 nm is extremely large, and furthermore, deterioration tends to occur with the absorption of energy. Therefore, when a light beam in the vacuum ultraviolet region is used as the illumination light for exposure (exposure light), quartz glass having a thickness of about several tens to several hundreds of micrometers is used as a pellicle for a mask protection device instead of a conventional organic thin film. The use of inorganic materials such as these has been studied.

However, in a mask protection device provided with a pellicle (hard pellicle) made of such an inorganic material, the thickness of the pellicle is increased as compared with a conventional organic thin film. The optical characteristics are likely to be degraded, such as a change in the optical axis, due to the bending (gravitational bending) caused by the bending. Therefore, exposure accuracy may be reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has a mask protection device and a mask protection device capable of suppressing the bending of a pellicle and preventing a decrease in optical characteristics due to the bending of the pellicle. And a mask. Another object of the present invention is to provide an exposure apparatus capable of improving exposure accuracy.

[0007]

According to a first aspect of the present invention, there is provided a frame (PF) and a pellicle (PE) attached to one end of the frame (PF). In the mask protection device (10),
A film (TSF, CSF) having a stress for correcting the deflection of the pellicle (PE) is provided on the surface of the pellicle (PE). In this mask protection device, since a film having a stress for correcting the deflection of the pellicle is provided on the surface of the pellicle, the deflection of the pellicle is corrected by the stress of the film.

In this case, as in the second aspect of the present invention, the film (TSF, CSF) is configured such that the stress is applied to the first surface of the pellicle (PE) and the first surface of the pellicle (PE) opposite to the first surface. The pellicle (P
Preferably, it is formed on at least one of the first surface and the second surface of E).

Further, such a mask protection device (10)
Is the pellicle (P) as in the third aspect of the present invention.
E) The pellicle (P)
It can be manufactured by forming a film for correcting the deflection of the pellicle (PE) on the surface of E).

In this case, the film (TSF, CSF) is formed such that the reflectance for light of a predetermined wavelength is low, as in the invention according to claim 4.
It is possible to suppress a decrease in optical characteristics due to reflection on the pellicle surface.

According to a fifth aspect of the present invention, there is provided a mask (M) on which a pattern to be transferred to a photosensitive substrate (W) by an energy beam (IL) is formed. A mask protection device (10) is attached to the surface on which the pattern is formed via the other end of the frame (PF). Further, the invention according to claim 6 provides an energy beam for exposure (I
An illumination system (51) for emitting L) and a mask (M) according to claim 5, wherein a pattern to be transferred to a photosensitive substrate (W) by the energy beam (IL) is formed. I do.

[0012]

Next, a mask protection device according to the present invention will be described. FIG. 2 is a perspective view of a mask M on which the mask protection device 10 of the present invention is mounted. The mask protection device 10 includes a pellicle PE that protects a pattern area PA formed on the mask M, and a pellicle frame PF that supports the pellicle PE at one end and is attached to the mask M at the other end. It is mounted around the pattern area PA so as to form a closed space 11 covering the area PA.

The pellicle PE has a wavelength of 120 to 200 nm.
In order to satisfactorily transmit vacuum ultraviolet light of a degree, the plate is made of, for example, a plate-like quartz glass (fluorine-doped quartz or the like) having a thickness of about 100 to 300 μm. As the material of the pellicle PE, other inorganic materials such as fluorite, magnesium fluoride, and lithium fluoride may be used in addition to quartz glass. On the other hand, the pellicle frame PF is formed by forming a metal such as aluminum or quartz glass in a rectangular frame shape, and each side of the pellicle frame PF has a pattern area PA.
There is provided a ventilation hole 12 for communicating a closed space 11 that covers the space and an external space. The communication holes 12 are provided for suppressing pressure fluctuation between the closed space 11 and the external space. The size and number of the communication holes 12 can be arbitrarily determined, and the pressure difference can be well controlled by other means. In such a case, it is not necessary to provide them. Further, it is preferable that a filter for preventing passage of a foreign substance having a predetermined size is provided in the ventilation hole 12.

FIG. 1A is a longitudinal sectional view of a mask protection device 10 mounted on a mask M, and FIG. 1B is an enlarged schematic diagram showing a cross section of a pellicle PE. It is assumed that the mask M is placed on the mask stage of the apparatus, that is, the surface on which the pattern area PA is formed is oriented downward. Mask protection device 1 of the present invention
In FIG. 1, as shown in FIG. 1B, deflection correction films TSF and CSF are formed on the surface of the pellicle PE to correct the deflection (gravity deflection) of the pellicle PE due to its own weight. The deflection correction films TSF and CSF have a stress (tensile stress or compressive stress) therein, and at least one of the acting direction and the magnitude of the stress is different between the upper and lower sides of the pellicle PE. Here, the symbol TSF indicates a deflection correction film having tensile stress,
Reference character CSF indicates a deflection correction film having compressive stress. In addition, the deflection correction film TS
The main raw material of F and CSF is yttrium fluoride (Y
F ₃ ), strontium fluoride (SrF ₂ ), gadolinium fluoride (GdF ₃ ), lanthanum fluoride (La)
F ₃ ), magnesium fluoride (MgF ₂ ), lutetium fluoride (LuF ₃ ), cryolite (Na ₃ Al)
F ₆ ), aluminum fluoride (AlF ₃ ), lithium fluoride (LiF), barium fluoride (BaF ₂ ), dysprosium fluoride (DyF ₃ ), calcium fluoride (Ca
It is preferable to use a fluoride such as F ₂ ) or fluorine-doped silica. In addition, not only a single fluoride but also a mixture of two or more fluorides may be used as a main raw material. Further, the deflection correction films TSF and CSF have a wavelength of 1
The material is not limited to fluoride as long as it can transmit vacuum ultraviolet light of about 20 to 200 nm. Next, FIGS. 3A to 3E show the deflection correction films TSF and CSF.
FIG. 1 shows a conceptual diagram of a pellicle PE in which is formed.

FIGS. 3A and 3B show a mask protection device 10 in which deflection correction films TSF and CSF are formed only on one side of a pellicle PE. In the mask protection device 10 shown in FIG. 3A, the deflection correction film TS having a tensile stress is provided.
F is formed on the lower surface of the pellicle PE (the surface opposite to the surface facing the pattern area PA; corresponding to the first surface of the present invention), and is formed on the lower surface of the pellicle PE by the tensile stress of the deflection correction film TSF. When the force in the contraction direction acts on the pellicle PE, the deflection (gravitational deflection) of the pellicle PE is corrected. On the other hand, in the mask protection device 10 shown in FIG. 3B, the deflection correction film CSF having compressive stress is formed on the upper surface of the pellicle PE (the surface facing the pattern area PA; corresponding to the second surface of the present invention). Since the force in the expansion direction acts on the upper surface of the pellicle PE due to the compressive stress of the deflection correction film CSF, the deflection of the pellicle PE is corrected.

FIGS. 3C, 3D, and 3E show a mask protection device 10 in which deflection correction films TSF and CSF are formed on both upper and lower surfaces of a pellicle PE. FIG. 3 (c)
In the mask protection device 10 shown in FIG. 1, a deflection correction film TSF having tensile stress is formed on the lower surface of the pellicle PE, and a deflection correction film CSF having compressive stress is formed on the upper surface of the pellicle PE. In the mask protection device 10, the deflection correction film C
The force in the expansion direction acts on the upper surface of the pellicle PE due to the compressive stress of SF, and the force in the contraction direction acts on the lower surface of the pellicle PE due to the tensile stress of the deflection correction film TSF. Will be corrected. Further, in the mask protection device 10 shown in FIG. 3D, the deflection correction film TSF having a tensile stress is provided on the upper surface of the pellicle PE on the upper surface of the pellicle PE.
SF is formed on the lower surface of pellicle PE. In the mask protection device 10, the force in the contraction direction acts on the lower surface of the pellicle PE due to the difference in the tensile stress of the deflection correction film TSF between the upper and lower parts of the pellicle PE, and thus the pellicle PE
Is corrected. Further, in the mask protection device 10 shown in FIG. 3E, the deflection correction film CS having a compressive stress is provided.
F is formed on the lower surface of the pellicle PE, and a deflection correction film CSF having a compressive stress greater than that of the lower surface is formed on the upper surface of the pellicle PE. In the mask protection device 10, the deflection in the expansion direction acts on the upper surface of the pellicle PE due to the difference in the compressive stress of the deflection correction film CSF between the upper and lower portions of the pellicle PE, whereby the deflection of the pellicle PE is corrected.

As described above, the mask protection device 10 of the present invention
In this example, since the deflection correction films TSF and CSF having a stress for correcting the deflection of the pellicle PE are formed on the surface of the pellicle PE, even when the pellicle PE is made of an inorganic material such as quartz glass, the deflection correction film TSF is formed. , CSF, a force in the compression direction or the expansion direction acts on the surface of the pellicle PE, and the deflection of the pellicle PE is suppressed.

Next, a method of manufacturing the mask protection device 10 of the present invention will be described. Mask protection device 10 of the present invention
Is formed on the surface of the pellicle PE with the above-described deflection correction films TSF and CSF for correcting the deflection of the pellicle PE based on information on the deflection (gravitational deflection) of the pellicle PE, and joins the pellicle PE and the pellicle frame PF. Can be manufactured.

The deflection of the pellicle PE can be determined, for example, by approximation analysis by the finite element method using physical properties (specific gravity, Young's modulus, etc.) of the pellicle PE, or by actually measuring the deflection of the pellicle PE. Here, FIG.
2 shows a configuration example of the deflection measuring device 20 that measures the deflection of the pellicle PE.

The deflection measuring apparatus 20 shown in FIG. 4 includes an XY stage 21 for holding a pellicle PE (before a deflection correction film is formed) to be measured, and a detection for detecting a height position of the surface of the pellicle PE. And a control unit 23 for calculating the deflection of the pellicle PE based on the detection result of the detection device 22. The height of the surface of the pellicle PE held on the XY stage 21 is measured at a predetermined pitch. Thus, the deflection of the entire surface of the pellicle PE is calculated.

In the deflection measuring device 20, the pellicle PE is XY-joined to the pellicle frame PF.
It is held on a stage 21 via a holding member 24, and is two-dimensionally moved stepwise at a predetermined pitch by the XY stage 21. The control device 23 detects the height position of the surface of the pellicle PE (the lower surface in FIG. 4) by the detection device 22 at each stop position of the XY stage 21, and together with the coordinate position of the XY stage 21 detected by the interferometer system 25. The detection result is stored. The detection device 22 includes, for example, a light source 22a that irradiates spot light to the surface of the pellicle PE from an oblique direction, and a light receiver 22b that receives light reflected by the surface of the pellicle PE via a pinhole 22c, Based on a detection signal obtained from the reflected light from the pellicle PE surface, the height position of the pellicle PE surface with respect to the in-focus position is detected.
No. 325 is used.
The controller 23 calculates the bending shape of the pellicle PE surface from the relationship between the detected coordinate position of the XY stage 21 and the height position of the pellicle PE surface. An example of the calculation method will be described below.

FIG. 5 shows detection points 31a-3 on the surface of the pellicle PE where the height position is detected by the deflection measuring device 20.
The example of arrangement of 1z is shown. Control device 23 (see FIG. 4)
From the data of the height positions of the detection points 31a to 31e arranged in the X direction on the surface of the pellicle PE and the coordinate position of the XY stage 21, firstly, the bending shape of the line 32a in the X direction is calculated as follows: Z = a ₁ X ⁴ + A ₂ X ³ + a ₃ X ² + a ₄ X + a ₅ (1) The approximation is made by the following quartic equation. For each of the five data on Z and X at the detection points 31a to 31e, the unknown a ₁
Since ~a ₅ is five, the quartic equation uniquely determined. Similarly, detection locations 31f to 31j in the X direction are sequentially
31k-31p, 31q-31u, and 31v-31z
, The fourth order equation of the bending shape is obtained.

Further, the control unit 23, the detection portion 31a~31v aligned in the Y-direction, firstly, a shape bending in the Y direction of the line ^{_{32b, Z = b 1 Y 4}} + b 2 Y 3 + b 3 Y 2 + B ₄ Y + b ₅ (2) It is approximated by the following quartic equation. Furthermore, the detection position 31 in the Y direction
b to 31w, 31c to 31x, 31d to 31y, and 3
Fourth-order equations of the bending shape are sequentially obtained for 1e to 31z. Thereby, as shown in FIG. 6, it is possible to obtain a bent shape of the entire surface of the pellicle PE before the deflection correction film is formed. Note that the detection locations are not limited to those shown in FIG. 5, and it goes without saying that the locations and numbers are arbitrary.

In the method of manufacturing the mask protection device 10 of the present invention, the conditions for forming the deflection correction film formed on the surface of the pellicle PE are determined based on the information on the deflection of the pellicle PE obtained as described above. A deflection correction film is formed on the surface of the pellicle PE based on the determined film forming conditions.
As a method of forming the deflection correction film, a vacuum deposition method is used in which a film-forming material is heated and melted and evaporated under vacuum to form a thin film on the surface of a film-forming material, and an atom of the film-forming material is accelerated by accelerating ion particles. A typical example is a sputtering method in which a thin film is formed on the surface of an object to be filmed by repelling, but in addition to this, a film forming method using a molecular beam or an ion beam, a chemical vapor deposition method, Other film forming methods such as a coating method such as spin coating, dip coating, roll coating, and spray coating may be used.

In the film formation method by the vacuum evaporation method, after performing degrease treatment and surface treatment for improving the adhesiveness between the pellicle PE as a film-forming object and the vapor-deposited film as required, the pellicle PE is subjected to vacuum. In a room controlled at a pressure of, the film-forming material heated to a predetermined temperature and melted / evaporated is attached to one or both surfaces of the surface of the pellicle PE, and cooled to room temperature. As a result, a residual stress due to the heat treatment is generated inside the film formed on the surface of the pellicle PE. That is, a film having a stress (here, residual stress of the heat treatment) can be formed on the surface of the pellicle PE by utilizing the heat treatment at the time of film formation. As a method for heating the film formation material, various methods such as a method using heat generated by electric resistance and a method using an electron beam are applied. After the film is formed, a protective film for protecting the deposited film from chemical and physical effects may be formed on the deposited film.

Here, the stress held by the deflection correction film when the deflection correction film having a predetermined thickness is formed on the surface of the pellicle PE by the above-described vacuum deposition method will be described below. In addition, each stress is shown about several typical film-forming materials, and the case where the heating temperature at the time of film formation is 150 degreeC and the case where it is 250 degreeC is shown in order. “+” Indicates tensile stress, and “−” indicates compressive stress.

The _{YF 3 ... + 200MPa (150 ℃} ), + 400MPa (250 ℃) SrF 2 ... -400MPa, -40MPa GdF 3 ... + 100MPa, + 80MPa LaF 3 ... + 50MPa, + 300MPa MgF 2 ... + 400MPa, + 300MPa LuF 3 ... + 250MPa, + 250MPa Na ₃ AlF ₆ (Cryolite) ... + 150MPa, + 200MPa

As described above, the stress possessed by the deflection correction film changes depending on the film forming material and the heating temperature during film formation.
Further, since the stress represents a force per unit area, changing the thickness of the deflection correction film changes the magnitude of the force acting on the surface of the pellicle PE. Therefore, for example, by adjusting film forming conditions such as a film forming material, a heating temperature during film forming, and a film thickness (film forming processing time), the pellicle P
It is possible to control the force acting on the surface of E in the contraction direction and the compression direction to a desired state. For example, pellicle PE
Strontium fluoride (SrF ₂ ) is formed on the upper surface of the pellicle PE at a heating condition of 150 ° C., and magnesium fluoride (MgF ₂ ) is formed on the lower surface of the pellicle PE at a heating condition of 150 ° C. with the same thickness as the upper surface. The compressive stress of 400 MPa causes a force in the direction of expansion to act on the upper surface of the pellicle PE, and the tensile stress of 400 MPa causes a force in the direction of contraction to the lower surface of the pellicle PE.
The deflection of E can be corrected.

Therefore, the mask protection device 10 of the present invention
In the manufacturing method of (1), the film formation conditions (film formation material, heating temperature during film formation, processing time, and film thickness) of the deflection correction film to be formed on the surface of the pellicle PE are determined based on information on the deflection of the pellicle PE. Thereby, the deflection of the pellicle PE can be reliably suppressed by the stress of the deflection correction film. The conditions for forming the deflection correction film are determined so that the deflection of the pellicle PE falls within a predetermined allowable range. As a standard for defining the allowable range of the bending, for example, flatness indicating a local inclination is used. This flatness is determined so that a decrease in optical characteristics such as a change in the optical axis due to the bending of the pellicle PE falls within an allowable range.

In the method of manufacturing the mask protection device 10 according to the present invention, it is desirable to determine the conditions for forming the deflection correction film so that the reflectance for light having a predetermined wavelength is low. Since the reflectivity to light changes depending on the refractive index, thickness, etc. of the film, by adjusting the material and thickness of the film (processing time for film formation) as a film forming condition, the light with a predetermined wavelength is adjusted. The deflection correction film can be formed so that the reflectance is low. Since the film forming conditions for controlling the reflectance overlap with the film forming conditions for controlling the force acting on the surface of the pellicle PE, a function of correcting the deflection of the pellicle PE,
It is preferable that the film forming conditions of the deflection correction film be determined so that the deflection correction film has both functions of an antireflection function for lowering the reflectance for light of a predetermined wavelength. By providing both of these functions in the pellicle PE, in the mask protection device 10 of the present invention, in addition to suppressing the deterioration of the optical characteristics due to the bending of the pellicle PE, the optical characteristics due to the reflection on the surface of the pellicle PE are suppressed. It is possible to suppress the decrease. Note that, as described above, the deflection correction film may be formed on only one side or both sides of the surface of the pellicle PE. Further, the thickness of the deflection correction film may be changed above and below the pellicle PE. Further, although only a single-layer structure has been described, the deflection correction film may have a stacked structure including a plurality of layers. When the deflection correction film has a laminated structure, the main raw material (film forming material) may be changed for each layer, and the above-described function of correcting the deflection and the antireflection function are separately provided for each layer. Is also good. Further, for example, when the pellicle PE has a high-order complicated bending, the film forming conditions (such as the film thickness) may be changed for each local region on the surface of the pellicle PE. In the above-described vacuum deposition method, the residual stress of the heat treatment is generated inside the film formed on the surface of the pellicle PE, but the method of generating the stress inside the film is limited to the method involving the heat treatment. Not something.

Next, the pellicle PE and the pellicle frame P
A method of joining with F will be described. As a method for joining the pellicle PE and the pellicle frame PF, a method using an adhesive, a method using an optical contact, or the like can be used. In the bonding method using an adhesive, for example, a pellicle PE and a pellicle frame P are bonded via an adhesive.
Clamp together with F and leave for a time until the adhesive hardens. In order to suppress the release of gas from the adhesive to vacuum ultraviolet light having a wavelength of about 120 to 200 nm, a fluorine-based resin that emits a small amount of gas is used as the adhesive, or a thin metal film is used so as to hide the joint. May be coated on the adhesive.

On the other hand, in a bonding method using an optical contact, for example, after a bonded portion of a pellicle PE and a pellicle frame PF is polished to an optical plane and then brought into contact with each other and pressed, the physical contact is called a physical contact. The pellicle PE and the pellicle frame PF can be fixed without the use of an adhesive due to a specific action. Further, the pellicle PE and the pellicle frame PF can be more firmly joined by heating the joints fixed to each other by the optical contacts to a predetermined temperature and welding them.

The mask M of the present invention includes the mask protection device 10 manufactured as described above for the purpose of preventing foreign matter from adhering to the pattern area PA. The circuit pattern formed on the mask M is, for example, an apparatus such as a pattern generator or an EB exposure apparatus.
It is transferred onto a glass substrate (fluorine-doped quartz or the like), which is a base material of the mask, based on predetermined design data, and is formed as a light-transmitting portion or a light-shielding portion (a chromium-deposited film, an aluminum-deposited film, or the like). FIGS. 7A to 7C show an example of the form of the mask M on which the mask protection device 10 is mounted. By joining the pellicle frame PF to the mask M, one side of the mask M (FIG. 7 (a)) or both sides (FIGS. 7 (b) and 7 (c)), the mask protection device 10 is mounted. As a method of joining the mask M and the pellicle frame PF, the pellicle PE and the pellicle frame PF described above are used.
As in the case of bonding with the substrate, a method using an adhesive or a method using an optical contact is used. When the mask protection device 10 is mounted on the mask M, usually,
After joining the mask M and the pellicle frame PF, the pellicle PE is joined to the pellicle frame PF. However, since the deflection correction film is formed on the pellicle PE, the pellicle frame PF and the pellicle PE may be bonded first, and then the mask M and the pellicle frame PF may be bonded. The deposition of the deflection correction film may be performed at any timing. In addition, mask protection devices 10
When the is attached, the thickness of the pellicle PE is changed above and below the mask M, and the properties of the deflection correction film formed on the pellicle PE above and below the mask M (the type, size, film thickness, etc. of the stress held inside). May be changed.

The above-described mask M of the present invention can be suitably used in a reduction projection type exposure apparatus for manufacturing a semiconductor device as shown in FIG. Hereinafter, a schematic configuration of the exposure apparatus shown in FIG. 8 will be described. The exposure apparatus 50 includes a mask M
A step-and-scan method in which a circuit pattern formed on a mask M is transferred to each shot area of a wafer W via a projection optical system PL while a wafer (or a reticle) and a wafer W are synchronously moved in a one-dimensional direction. , A so-called scanning stepper.

An energy beam (exposure light) IL from an exposure light source is applied to a predetermined illumination area on the mask M via the illumination system 51 with a uniform illuminance distribution. As the exposure light IL, for example, a KrF excimer laser (248 n
m), ArF excimer laser (193 nm), F ₂ laser (157 nm), higher harmonics of metal vapor laser, YAG laser, or ultraviolet emission line of ultra-high pressure mercury lamp (g)
Line, i-line, etc.).

The mask M is disposed with the surface on which the pattern area PA is formed facing downward, and is held by the mask stage RS. The mask stage RS is a mask stage drive system 5
2 to perform one-dimensional scanning movement in the X-axis direction, and is also driven in the Y-axis direction and the rotation direction (θ
(Direction) is supported by the column 53. Here, a direction parallel to the optical axis of the projection optical system PL is defined as a Z direction, and a relative scanning direction (a direction parallel to the paper) between the mask M and the illumination area in a plane perpendicular to the optical axis is defined as an X-axis direction. The direction orthogonal to this is the Y-axis direction. The two-dimensional position of the mask stage RS is sequentially detected by the laser interference type length measuring device 54.

The wafer W is mounted on a wafer stage ST that moves two-dimensionally in the X and Y axes. The wafer stage ST is fixed in the X-axis direction and the Y-axis direction in a plane perpendicular to the optical axis of the projection optical system PL so that the pattern image of the mask M is transferred for each shot area set on the wafer W. The wafer W is moved stepwise by an amount. Also,
In the wafer stage ST, two-dimensional coordinate values are sequentially detected by a laser interference type length measuring device 55, and a wafer stage drive system 56 is controlled based on the coordinate values. In addition,
The wafer stage ST includes a Z stage (not shown) for slightly moving the wafer W in the Z direction (optical axis direction),
And a not-shown θ stage for slightly rotating the XY plane in the XY plane are provided. Reference numeral 57 denotes a control device that controls the entire apparatus as a whole.
It comprises a microcomputer (or minicomputer) including a U (central processing unit), a ROM (read only memory), a RAM (random access memory) and the like.

With such a configuration, in the exposure apparatus 50,
Under the exposure light IL from the exposure light source, an image of the circuit pattern in the illumination area of the mask M is exposed at a predetermined projection magnification β (β is, for example, 1/4, 1/5, etc.) to a photosensitive material (photoresist). )
Is projected and exposed on the wafer W on which is coated. At this time,
In the exposure apparatus 50, as described with reference to FIG. 1A, quartz glass is used as a material of the pellicle PE of the mask protection apparatus 10 for protecting the pattern area PA of the mask M. For example, an F ₂ laser (157 n
In the case where vacuum ultraviolet light in a short wavelength band such as m) is used as the exposure light IL, the energy absorption of the exposure light IL by the pellicle PE is suppressed, and the exposure light IL reaches the wafer W with sufficient illuminance. Can be. Further, as described above, the deflection correction films TSF and CSF (see FIG. 1) having the stress for correcting the deflection of the pellicle PE are formed on the surface of the pellicle PE, and the stresses held by the deflection correction films TSF and CSF are formed. As a result, the bending of the pellicle PE is suppressed to a small degree, so that the deterioration of the optical characteristics due to the bending of the pellicle PE is suppressed, and the circuit pattern of the mask M can be accurately transferred onto the wafer W.

It should be noted that the shapes, combinations, and the like of the respective constituent members shown in the above-described embodiment are merely examples, and various changes can be made based on design requirements without departing from the gist of the present invention.

For example, in the above-described embodiment, the actual deflection of the pellicle PE before the formation of the deflection correction film is measured by the deflection measuring device 20, and based on the deflection information at that time, the surface of the pellicle PE is measured. The deflection correction film is formed on the pellicle PE. After the film formation, the deflection of the pellicle PE is measured again, and the deflection correction film is repeatedly formed on the pellicle PE so as to obtain a pellicle PE with a smaller deflection. Is also good.
Furthermore, in addition to the deflection measuring device 20, by measuring the optical characteristics (such as flare) of the pellicle PE after film formation by an optical device, it is possible to reliably manufacture the mask protection device 10 with a small decrease in the optical characteristics. Becomes possible.

In the above-described embodiment, the wavelength 12
In order to satisfactorily transmit vacuum ultraviolet light of about 0 to 200 nm, an inorganic material such as quartz glass, fluorite, magnesium fluoride, or lithium fluoride is used as the material of the pellicle PE. When a light flux other than vacuum ultraviolet light, such as i-line or g-line, is used, a normal glass material may be used.

Further, in order to always keep the pellicle PE flat in response to a change in the environment in which the mask M is disposed, in addition to the deflection correction film shown in the above-described embodiment, the mask protection device 10 A device for controlling the atmospheric pressure in the closed space 11 may be provided. For example, in order to correct the deflection of the pellicle PE, the inside of the closed space 11 formed by the pellicle PE, the pellicle frame PF, and the mask M is evacuated (depressurized) through the ventilation holes 12 formed in the pellicle frame PF. do it.

The exposure apparatus 50 is a step-and-repeat type exposure apparatus (stepper) that exposes the pattern of the mask M while the mask M and the wafer W are stationary and sequentially moves the wafer W in steps. Obviously, also can be applied.

When a vacuum ultraviolet ray such as an excimer laser is used as the projection optical system PL, a material that transmits vacuum ultraviolet ray such as quartz or fluorite is used as a glass material, and F ₂ is used.
If a laser or X-ray is used, use a catadioptric or refractive optical system (use a reflective type mask as well)
When an electron beam is used, an electron optical system including an electron lens and a deflector may be used as the optical system. It goes without saying that the optical path through which the electron beam passes is in a vacuum state.

Further, the magnification of the projection optical system is not limited to the reduction magnification, but may be the same magnification or enlargement.

In the present invention, the case where ArF excimer laser light (wavelength 193 nm) is used as the exposure light,
r ₂ laser light (146 nm), Ar ₂ laser light (12
This is particularly effective when vacuum ultraviolet light having a wavelength of about 200 to 100 nm is used, such as 6 nm), a harmonic such as a YAG laser, or a high frequency of a semiconductor laser. As the exposure light, a bright line (g-line (436
nm), h-line (404.7 nm), i-line (365n)
m)) and, not KrF excimer laser, ArF excimer laser, F ₂ laser alone, or the like can be used charged particle beams such as X-ray or electron beam. For example, when an electron beam is used, thermionic emission type lanthanum hexaborite (LaB6) or tantalum (Ta) can be used as the electron gun.

The application of the exposure apparatus is not limited to an exposure apparatus for manufacturing a semiconductor. For example, an exposure apparatus for a liquid crystal for exposing a liquid crystal display element pattern to a square glass plate or a thin film magnetic head may be used. It can be widely applied to an exposure apparatus for manufacturing.

When a linear motor is used for the wafer stage or the mask stage, any of an air floating type using an air bearing and a magnetic floating type using a Lorentz force or a reactance force may be used. Further, the wafer stage and the mask holder may be of a type that moves along a guide, or may be of a guideless type without a guide.

When a plane motor is used as a driving device for the wafer stage or the mask stage, one of a magnet unit (permanent magnet) and an armature unit is connected to the stage, and the other of the magnet unit and the armature unit is connected. May be provided on the moving surface side (base) of the stage.

Further, the reaction force generated by the movement of the wafer stage is mechanically controlled by using a frame member as described in JP-A-8-166475.
You may escape to The present invention is also applicable to an exposure apparatus having such a structure.

As described above, the exposure apparatus according to the embodiment of the present invention converts various subsystems including the components described in the claims of the present application into predetermined mechanical accuracy, electrical accuracy,
It is manufactured by assembling to maintain optical accuracy. Before and after this assembly, adjustments to achieve optical accuracy for various optical systems, adjustments to achieve mechanical accuracy for various mechanical systems, and various electric systems to ensure these various accuracy Are adjusted to achieve electrical accuracy. The process of assembling the various subsystems into the exposure apparatus includes mechanical connection, wiring connection of an electric circuit, and piping connection of a pneumatic circuit between the various subsystems. It goes without saying that there is an assembling process for each subsystem before the assembling process from these various subsystems to the exposure apparatus. When the process of assembling the various subsystems into the exposure apparatus is completed, comprehensive adjustment is performed, and various precisions of the entire exposure apparatus are secured. It is desirable that the exposure apparatus be manufactured in a clean room in which the temperature, cleanliness, and the like are controlled.

The device (semiconductor element, liquid crystal display element, image pickup element (CCD, etc.), thin-film magnetic head, etc.) has a step of designing the function and performance of the device, and a mask (reticle) is manufactured based on the design step. , A step of manufacturing a wafer from a silicon material, a wafer processing step of exposing a mask pattern to the wafer by the exposure apparatus of the above-described embodiment, a device assembling step (including a dicing step, a bonding step, and a package step), and inspection. It is manufactured through steps and the like.

[0053]

As described above, according to the present invention, the following effects can be obtained. According to the mask protection device of the first and second aspects, the method of manufacturing the mask protection device of the third and fourth aspects, and the mask of the fifth aspect, the mask is formed on the surface of the pellicle. The bending of the pellicle can be suppressed by the stress of the film, and the deterioration of the optical characteristics due to the bending of the pellicle can be prevented. Claim 6
According to the exposure apparatus described in (1), since the mask having less deflection of the pellicle is provided, the exposure accuracy can be improved.

[Brief description of the drawings]

FIG. 1 shows a mask protection device according to the present invention,
(A) is a longitudinal cross-sectional view of the mask protection device, and (b) is a schematic diagram showing an enlarged cross section of the pellicle.

FIG. 2 is a perspective view showing an embodiment of a mask on which a mask protection device according to the present invention is mounted.

FIG. 3 is a conceptual diagram of a mask protection device including a pellicle on which a deflection correction film is formed.

FIG. 4 is a configuration diagram showing a deflection measurement device that measures deflection of a pellicle.

5 is a diagram showing an example of the arrangement of detection locations on the surface of a pellicle where deflection is detected by the deflection measuring device of FIG. 4;

FIG. 6 is a diagram showing a state of bending of a pellicle.

FIG. 7 is a diagram showing an example of a form of a mask M on which a mask protection device is mounted.

FIG. 8 is a configuration diagram illustrating an embodiment of an exposure apparatus including a mask according to the present invention.

FIG. 9 is a schematic diagram showing a state of an optical axis associated with bending of a pellicle.

[Explanation of symbols]

 M Mask PA Pattern area PE Pellicle PF Pellicle frame TSF, CSF Deflection correction film (film) IL Exposure light (energy beam) PL Projection optical system W Wafer (substrate) 10 Mask protection device 50 Exposure device 51 Illumination system

Claims (6)

[Claims] 1. A mask protection device comprising a frame and a pellicle attached to one end of the frame, wherein a film having a stress for correcting a deflection of the pellicle is provided on a surface of the pellicle. Mask protection device. 2. The first and second surfaces of the pellicle such that the stress is different between a first surface of the pellicle and a second surface opposite to the first surface. The mask protection device according to claim 1, wherein the mask protection device is formed on at least one of the following. 3. A method of manufacturing a mask protection device comprising a frame and a pellicle attached to one end of the frame, wherein the deflection of the pellicle is corrected on the surface of the pellicle based on information on the deflection of the pellicle. A method for manufacturing a mask protection device, comprising forming a film to be formed. 4. The method according to claim 3, wherein the film is formed so as to have a low reflectance with respect to light having a predetermined wavelength. 5. A mask on which a pattern to be transferred to a photosensitive substrate by an energy beam is formed, wherein the pattern is formed by the mask protection device according to claim 1 or 2 via the other end of the frame. A mask characterized by being attached to a surface. 6. An exposure apparatus comprising: an illumination system that emits an energy beam for exposure; and a mask according to claim 5, wherein a pattern to be transferred to a photosensitive substrate by the energy beam is formed.