JP4416233B2 - Method of supporting a frame of a semiconductor exposure apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to support how the installation for platform of a semiconductor exposure device.
[0002]
[Prior art]
When the semiconductor exposure apparatus is installed on the building floor, the semiconductor exposure apparatus is usually installed on the building floor via an installation stand as shown in FIG. That is, a mounting base 102 for installing a semiconductor exposure apparatus (hereinafter, also simply referred to as an exposure apparatus) 101 is connected to a building floor 104 by a base support means 105, and the semiconductor exposure apparatus 101 is mounted on the base 102 with an apparatus support means 103. The height of the gantry 102 is designed so that the upper surface of the gantry 102 and the access floor 108 have the same height. The exposure apparatus installation stand 102 is an important element that serves as an interface between the building floor 104 and the exposure apparatus 101 as described below.
[0003]
The access floor 108 vibrates when an operator walks on the access floor 108, and the vibration based on the walking is transmitted to the building floor 104 and the gantry 102 and also vibrates the exposure apparatus 101. Further, in the factory where the exposure apparatus 101 is installed, various vibrations such as vibrations of air-conditioning fans are generated in addition to walking vibrations, and these vibrations are also transmitted to the exposure apparatus 101 via the building floor 104 and the frame 102. . In addition to the vibration around the exposure apparatus, there is vibration due to the excitation force generated by the exposure apparatus itself. The exposure apparatus 101 is equipped with a stage for moving the wafer and reticle, and the driving reaction force due to the movement of these at high speed finally vibrates the gantry 102 via the apparatus support means 103. Further, the oscillating force generated by the air conditioner installed in the apparatus also causes the gantry 102 to vibrate. In this way, the excitation source outside the apparatus and the excitation source inside the apparatus vibrate the gantry 102.
[0004]
The exposure apparatus 101 is intended to expose and transfer a fine pattern on the reticle onto the wafer surface. Therefore, if the apparatus has a large floor vibration, the exposure performance of the apparatus is deteriorated. For this reason, the exposure apparatus 101 defines an allowable value of floor vibration as an apparatus installation specification. In order to satisfy this vibration condition, sufficient attention must be paid to vibration when designing a pedestal that is a direct floor for the apparatus.
[0005]
The design procedure of the installation stand for the exposure apparatus is normally performed according to a flowchart as shown in FIG. Here, the specifications (step S1) for the pedestal include those related to the exposure apparatus and those related to the building. The requirements on the apparatus side include apparatus dimensions, apparatus load, apparatus mounting surface accuracy, apparatus floor vibration tolerance, and the like. The building side requirements include load bearing capacity, height between the building floor and the access floor. A platform that satisfies these given specifications is designed (step S2). Next, it is verified whether the designed gantry satisfies the specified specification (step S3). At the time of verification, the dimensions and surface accuracy of the gantry can be easily verified on the design drawing, but the specifications on the vibration cannot be verified on the drawing. Therefore, it is usually verified using the FEM model of the gantry and the building whether the vibration of the gantry due to the apparatus exciting force submitted from the apparatus side satisfies the floor vibration standard of the apparatus. The sum of the vibration generated by the floor vibration as a result of applying the apparatus excitation force to the FEM model and the dark vibration of the building must satisfy the floor vibration tolerance of the apparatus. As a result of verification, if the vibration characteristics or the like do not satisfy the specifications, the design is corrected and verification is performed again (steps S2 to S3).
[0006]
[Problems to be solved by the invention]
However, satisfying the vibration specifications in the process of designing the exposure apparatus mounting stand described above is time consuming and it is difficult for the FEM model to sufficiently approximate the actual object in the region of slight vibration. For this reason, the reliability of the verification result is low, which is a difficult design issue.
[0007]
Therefore, the present invention has been made in view of the above-mentioned unsolved problems of the prior art, and uses the product of the mass of the gantry and the support rigidity as an index for determining the vibration characteristics of the gantry for installing the semiconductor exposure apparatus. This makes it easy to design the gantry, and allows semiconductor exposure equipment to exhibit sufficient performance without making excessive demands on the gantry, and also provides excellent cost performance. It is an object of the present invention to provide a device support method and a support device.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, a method for supporting a gantry of a semiconductor exposure apparatus according to the present invention provides a gantry support for a semiconductor exposure apparatus in which a gantry on which a semiconductor exposure apparatus is mounted via an apparatus support means is connected to a building floor via the gantry support means. in the method, the rack stand mass M, frame rigidity of the support means K, the maximum value of the force platform receives from the exposure apparatus as F _0, V ₀ the floor vibration tolerance of the exposure apparatus, the force obtained in advance based on the maximum value F ₀ and the floor vibration tolerance, so as to satisfy the following equation, and the first determining step of determining a range of the product of the stiffness of the mass and cradle support means of the stand,
V ₀ > F ₀ / (M · K) ^1/2
A second determination step of determining each of the mass of the gantry and the rigidity of the gantry support means so as to satisfy the range of the product of the mass of the gantry and the rigidity of the gantry support means determined in the first determination step; And the supporting step of supporting the semiconductor exposure apparatus by the gantry supporting means and the gantry supporting means determined in the deciding step, and in the first deciding step, the mass of the gantry and the gantry supporting means product of stiffness, wherein the ^{3 × 10 11 [kg / s} ] greater than ^{2 6 × 10 12 [kg /} s] that you determined to a value smaller than ² range.
[0009]
In the gantry support method for a semiconductor exposure apparatus according to the present invention, the gantry support means is made of a plastically deformable material or powder, and the gantry support means is fixed to the building by plastically deforming the gantry support means when the gantry is installed. It is preferable to do.
[0010]
In the gantry support method of the semiconductor exposure apparatus according to the present invention, it is preferable that leveling means for enabling leveling of the gantry as a whole is arranged in series with the gantry support means between the gantry and the gantry support means.
[0014]
[Action]
According to cradle support how the semiconductor exposure apparatus of the present invention, as an index for appropriately designing the vibration characteristics of the installation for the gantry of the semiconductor exposure apparatus to the semiconductor exposure apparatus, the rigidity of the mass M and cradle support means of the frame By using the product of K and setting this product within a predetermined range, it is possible to have an appropriate vibration characteristic as a gantry, and because the degree of freedom in design is high, the design can be performed easily. it is possible to reduce the manufacturing operation cost.
[0015]
In addition, by using a plastically deformable material or powder as the pedestal support means, the degree of adhesion between the pedestal and the building floor is increased, and the semiconductor exposure apparatus can be installed favorably. By providing the leveling means, the level of the gantry can be adjusted, and the level required by the semiconductor exposure apparatus can always be maintained.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings.
[0017]
Example 1
FIG. 1 is a schematic block diagram showing an example of a gantry support apparatus used for carrying out a gantry support method of a semiconductor exposure apparatus according to the present invention, and FIG. 2 shows vibration related to vibration of the gantry in the gantry support apparatus of the semiconductor exposure apparatus. It is a model.
[0018]
In FIG. 1, a gantry 2 for installing a semiconductor exposure apparatus 1 is connected to a building floor 4 via a gantry support means 5, and the semiconductor exposure apparatus 1 is mounted on the gantry 2 via an apparatus support means 3. The height of the gantry 2 is designed so that the upper surface of the gantry 2 and the access floor (not shown) have the same height. As the gantry support means 5 for supporting the gantry 2 with respect to the building floor 4, a highly rigid means such as an adhesive or bolt fastening is usually selected.
[0019]
Next, the characteristics required for the frame for installing the semiconductor exposure apparatus will be described using the vibration model shown in FIG. 2, which is the simplest model related to the vibration of the frame.
[0020]
In FIG. 2, M is the mass of the gantry 2, K is the support rigidity of the gantry support means 5 between the gantry 2 and the building floor 4, and D is the viscosity coefficient of the gantry support means 5 between the gantry 2 and the building floor 4. In order for an actual vibration system to be approximated by this model, it is assumed that the rigidity of the gantry body is sufficiently higher than the rigidity of the gantry support part. Here, for the sake of clarity, only vibrations in one axial direction are considered. However, in actual design, the sum of the three orthogonal X, Y, and Z directions and the rotational three axial directions around those axes. It is necessary to design the same for the six axes.
[0021]
As a method for defining the vibration characteristics required for the gantry, for example, there is a method of specifying the resonance frequency fn. In this case, the resonance frequency fn [Hz], the mass M [kg] of the gantry, and the support rigidity K [N / m] of the gantry have the following relationship.
fn = (K / M) ^1/2 / 2π
[0022]
Therefore, when realizing a mount with a specified resonance frequency, it is easy to manufacture the mount by reducing the mass and selecting a connection with high rigidity. However, the mass of the gantry must be increased to some extent due to the necessity of securing the height to the access floor, suppressing deformation due to the weight of the device, and increasing the rigidity of the gantry body. I don't get it. When the mass of the gantry increases, the support stiffness that satisfies the specified resonance frequency increases in proportion to the mass, and thus it becomes difficult to realize such a support stiffness. Therefore, in the method of specifying the resonance frequency in this way, there is a high possibility that it becomes an excessive demand for the gantry.
[0023]
From the vibration model shown in FIG. 2, it can be seen that there is a trade-off with respect to the magnitude of vibration between the gantry mass M and the support rigidity K of the gantry support part. In other words, if the mass M of the gantry is large, a gantry with small vibration can be produced even if the support stiffness K is reduced. Conversely, if the gantry mass M is small, the vibration is small if the support stiffness K is high. Become. Here, mobility is used as an index adapted to such physical characteristics. Mobility is a transfer function up to the speed of a point generated by the force when a force is applied to the point. The vibrational mobility shown in FIG. 2 is as shown in FIG.
[0024]
In FIG. 3, fn is the resonance frequency of this vibration system. The vibration characteristic in the low frequency region below the resonance frequency is approximately represented by line 1, and the vibration characteristic in the high frequency region above the resonance frequency is approximated by line 2. It is expressed. Line 1 is determined by the rigidity K of the vibration system, and line 2 is a straight line determined by the mass M of the vibration system. Thus, the low frequency vibration is suppressed by the stiffness K, and the high frequency vibration is suppressed by the mass M. The intersection of these two lines is the resonance frequency fn, and the gain at this time is represented by 1 / (M · K) ^1/2 . Therefore, if the influence of the viscosity coefficient D is ignored, the maximum value of mobility is 1 / (M · K) ^1/2 , and the floor vibration with respect to the excitation force generated in the device is applied to this mobility. By multiplying, the floor vibration speed can be obtained.
[0025]
Therefore, if the maximum value of the exposure apparatus excitation force is Fo [N] and the floor vibration allowable value of the exposure apparatus is a constant floor vibration speed Vo [m / s] (see FIG. 4),
Vo> Fo / (M ・ K) ^1/2
That is,
M · K> (Fo / Vo) ² [kg / s] ²
When the product (M · K) of the mass M of the gantry and the support rigidity K of the gantry is determined, the floor vibration speed other than the vicinity of the resonance frequency can be suppressed to the floor vibration speed Vo or lower.
[0026]
When the design is made so that the maximum value of the apparatus excitation force is constant in the entire frequency range and the product of M and K (M · K) is constant, the vibration characteristics of the gantry are approximate characteristics A and B in FIG. , C, and can always be designed within a certain range with respect to the floor vibration allowable value Vo. Here, the maximum values of the approximate characteristics A, B, and C are VA, VB, and VC, respectively, and are equal to Vm. On the other hand, when the resonance frequency is designed to be constant (fn = f3), the approximate characteristics a, b, and c shown in FIG. 6 are obtained, and the maximum values of the respective speeds are Va, Vb, and Vc. The relationship to the vibration tolerance value Vo is not determined. In this way, if the design is such that the product of M and K (M · K) is constant, the characteristics of the pedestal can be rationally designed for the floor vibration tolerance value compared to the method of specifying the resonance frequency. can do.
[0027]
As described above, it is preferable to use the product (M · K) of the mass M of the gantry and the support rigidity K of the gantry as an index for determining the vibration characteristics of the gantry. However, in practice, the magnitude of vibration near the resonance frequency is governed by the viscosity coefficient D. Further, the excitation force has a frequency spectrum and is not constant in the entire frequency region. Therefore, based on these points, actual device and platform design examples, and actual measurement values, various M and K products (M · K) were obtained. As a result, the product of M and K (M · K) was It was found that the vibration characteristics as a frame of the exposure apparatus are appropriate when set in the range of.
3 × 10 ¹¹ <M · K <6 × 10 ¹² [kg / s] ² (1)
[0028]
When the design index is determined as described above, the product of the gantry mass M and the gantry support stiffness K is specified, but the degree of freedom in design is large. For example, when the mass of the gantry increases, the support rigidity can be designed to be low, and when the mass of the gantry becomes small, the requirement for the gantry can be satisfied by designing the support rigidity high. In this way, designing according to individual cases is possible.
[0029]
As described above, the product (M · K) of the mass M [kg] of the gantry and the support rigidity K [N / m] is used as an index for appropriately designing the vibration characteristics of the gantry for the exposure apparatus. By restricting the product to the range of the above-described formula (1), it is possible to provide an appropriate vibration characteristic as a pedestal for the exposure apparatus, and it is possible to reduce the manufacturing cost because of a high degree of design freedom.
[0030]
(Example 2)
The configuration of this embodiment is the same as that of Embodiment 1 described above, and will be described with reference to FIG. As a method of connecting the gantry 2 to the building floor 4, bolt fastening or adhesive can be used as described above, but when using bolt fastening, it is necessary to make a hole in the beam, but the clean room in operation It is difficult to perform this work in the office. This is because the vibration caused by the construction deteriorates the performance of the peripheral equipment. Further, when an adhesive is used, there is a problem that once the adhesive is fixed, it is difficult to change the layout next.
[0031]
Therefore, in this embodiment, a support member made of a plastically deformable material or powder is used as the pedestal support means 5 for connecting the pedestal 2 for installing the exposure apparatus to the building floor 4. Examples of the support member made of a plastically deformable material or powder include metals such as lead and various synthetic resins. By using such plastically deformable material or powder, the degree of adhesion between the gantry 2 and the building floor 4 is increased, and there is no backlash between the two, so that a good installation is possible.
[0032]
(Example 3)
FIG. 7 shows a schematic configuration diagram of Embodiment 3 of the present invention.
[0033]
Although the pedestal on which the exposure apparatus is mounted needs to maintain the level required by the exposure apparatus main body, it is difficult to precisely set the level when installing the pedestal. Therefore, in this embodiment, as shown in FIG. 7, leveling means 6 is provided in series with the gantry support means 5 between the gantry 2 and the gantry support means 5. The leveling means 6 and the gantry 2 are connected with sufficiently high rigidity. The pedestal support means 5 for connecting the leveling means 6 and the building floor 4 is connected by an adhesive as in the first embodiment or a member made of a plastically deformed material as in the second embodiment.
[0034]
With such a structure, it is possible to easily adjust the level of the entire gantry 2 by adjusting the leveling means 6.
[0035]
Next, an embodiment of a device manufacturing method using the above-described semiconductor exposure apparatus will be described.
[0036]
FIG. 10 shows a flow of manufacturing a microdevice (a semiconductor chip such as an IC or LSI, a liquid crystal panel, a CCD, a thin film magnetic head, a micromachine, etc.). In step S11 (circuit design), a device pattern is designed. In step S12 (mask production), a mask on which the designed pattern is formed is produced. On the other hand, in step S13 (wafer manufacture), a wafer is manufactured using a material such as silicon or glass. Step S14 (wafer process) is called a pre-process, and an actual circuit is formed on the wafer by lithography using the prepared mask and wafer. The next step S15 (assembly) is called a post-process, and is a process for forming a semiconductor chip using the wafer produced in step S14, and is a process such as an assembly process (dicing, bonding), a packaging process (chip encapsulation), or the like. including. In step S16 (inspection), the semiconductor device manufactured in step S15 undergoes inspections such as an operation confirmation test and a durability test. Through these steps, the semiconductor device is completed and shipped (step S17).
[0037]
FIG. 11 shows a detailed flow of the wafer process. In step S21 (oxidation), the wafer surface is oxidized. In step S22 (CVD), an insulating film is formed on the wafer surface. In step S23 (electrode formation), an electrode is formed on the wafer by vapor deposition. In step S24 (ion implantation), ions are implanted into the wafer. In step S25 (resist process), a resist is applied to the wafer. In step S26 (exposure), the circuit pattern of the mask is arranged in a plurality of shot areas on the wafer and printed by the semiconductor exposure apparatus described above. In step S27 (development), the exposed wafer is developed. In step S28 (etching), portions other than the developed resist image are removed. In step S29 (resist stripping), the resist that has become unnecessary after the etching is removed. By repeating these steps, multiple circuit patterns are formed on the wafer.
[0038]
By using such a device manufacturing method, it is possible to stably manufacture a highly integrated device that has been difficult to manufacture at a low cost.
[0039]
【The invention's effect】
As described above, according to the present invention, the product of the mass M of the gantry and the rigidity K of the gantry support means is used as an index for appropriately designing the vibration characteristics of the gantry for installing the semiconductor exposure apparatus with respect to the semiconductor exposure apparatus. Use, by setting this product within a predetermined range, it is possible to have an appropriate vibration characteristic as a frame for installing a semiconductor exposure apparatus, and since the degree of freedom in design is high, the design can be easily performed, It is also possible to reduce production costs.
[0040]
Further, by using a plastically deformable material or powder as the gantry support means, the degree of adhesion between the gantry for installing the semiconductor exposure apparatus and the building floor is increased, and the semiconductor exposure apparatus can be satisfactorily installed. By arranging the leveling means between the installation base and the base support means, the level of the base can be adjusted, and the level required by the exposure apparatus can always be maintained.
[Brief description of the drawings]
FIG. 1 is a schematic block diagram showing an example of a gantry support apparatus used for carrying out a gantry support method for a semiconductor exposure apparatus according to the present invention.
FIG. 2 is a vibration model related to the vibration of the gantry in the gantry support device of the semiconductor exposure apparatus.
FIG. 3 is a diagram showing mobility of the vibration model shown in FIG. 2;
4 is a diagram showing the vibration characteristics of the vibration model shown in FIG. 2;
FIG. 5 is a diagram illustrating vibration characteristics in a method of specifying mass × support rigidity.
FIG. 6 is a diagram illustrating vibration characteristics in a method for designating a resonance frequency.
FIG. 7 is a schematic block diagram showing another example of the gantry support device used for carrying out the gantry support method of the semiconductor exposure apparatus according to the present invention.
FIG. 8 is a flowchart showing a procedure for designing a frame for installing a semiconductor exposure apparatus.
FIG. 9 is a schematic block diagram showing the relationship between an installation frame and a building floor in a normal general semiconductor exposure apparatus.
FIG. 10 is a flowchart showing manufacturing steps of a semiconductor device.
FIG. 11 is a flowchart showing a wafer process.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Semiconductor exposure apparatus 2 Base 3 Apparatus support means 4 Building floor 5 Base support means 6 Leveling means

Claims (3)

In a gantry support method for a semiconductor exposure apparatus in which a gantry for mounting a semiconductor exposure apparatus via an apparatus support means is connected to a building floor via a gantry support means.
The rack stand of mass M, frame rigidity of the support means K, the exposure apparatus F ₀ the maximum value of the force platform receives _from, the V ₀ of the floor vibration tolerance of the exposure apparatus, previously obtained the force of a maximum value A first determination step for determining a range of a product of the mass of the gantry and the rigidity of the gantry support means so as to satisfy the following formula based on F ₀ and the floor vibration tolerance:
V ₀ > F ₀ / (M · K) ^1/2
A second determination step of determining each of the mass of the gantry and the rigidity of the gantry support means so as to satisfy the range of the product of the mass of the gantry and the rigidity of the gantry support means determined in the first determination step;
A support step of supporting the semiconductor exposure apparatus by the gantry having the mass and rigidity determined in the second determination step and the gantry support means;
In the first determining step, the product of the mass of the gantry and the stiffness of the gantry support means is larger than 3 × 10 ¹¹ [kg / s] ^{2 and} smaller than 6 × 10 ¹² [kg / s] ^2. A method for supporting a gantry of a semiconductor exposure apparatus, wherein the pedestal is determined so as to satisfy the following value.   2. The semiconductor according to claim 1, wherein the gantry support means is made of a plastically deformable material or powder, and the gantry support means is plastically deformed when the gantry is installed to fix the gantry to the building. A method for supporting a frame of an exposure apparatus.   3. A pedestal for a semiconductor exposure apparatus according to claim 1, wherein leveling means for enabling leveling of the whole gantry is arranged in series with the gantry support means between the gantry and the gantry support means. Support method.

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