阅读说明：本技术 一种光刻机掩模台隔振装置 (Mask table vibration isolation device of photoetching machine ) 是由 吴剑威 李昌其 张银 晏祯卓 潘健生 赵鹏越 谭久彬 于 2021-09-22 设计创作，主要内容包括：本发明涉及振动抑制领域,公开了一种光刻机掩模台隔振装置,该光刻机掩模台隔振装置包括：掩模台基座,投影物镜套筒,以及连接所述掩模台基座及所述投影物镜套筒的连接装置,其中连接装置为柔性支撑的装置,并且竖直放置的柔性片摆放成等腰三角形形状。本发明的有益效果为：通过柔性连接装置将掩模台基座与投影物镜套筒之间的连接形式从刚性连接转变为柔性连接,并且连接装置的三个支撑组件呈等腰三角形布置,支撑平稳可靠,同时利用竖直放置的柔性片使得连接装置在掩模台水平方向上具有低刚度甚至零刚度的特性,进而在掩模台水平方向上起到隔振效果。(The invention relates to the field of vibration suppression, and discloses a mask table vibration isolation device of a lithography machine, which comprises: the mask table comprises a mask table base, a projection objective sleeve and a connecting device for connecting the mask table base and the projection objective sleeve, wherein the connecting device is a device which is flexibly supported, and flexible sheets which are vertically placed are placed into an isosceles triangle shape. The invention has the beneficial effects that: the connection form between the mask table base and the projection objective sleeve is changed from rigid connection to flexible connection through the flexible connection device, three support assemblies of the connection device are arranged in an isosceles triangle shape, the support is stable and reliable, meanwhile, the connection device has the characteristic of low rigidity or even zero rigidity in the horizontal direction of the mask table by utilizing the vertically placed flexible sheets, and then the vibration isolation effect is achieved in the horizontal direction of the mask table.)

1. A vibration isolation device for a mask stage of a lithography machine, comprising: a mask stage base, a projection objective sleeve, and a connecting device connecting the mask stage base and the projection objective sleeve;

connecting device includes first supporting component, second supporting component and third supporting component, first supporting component second supporting component and third supporting component are in the coplanar, first supporting component includes: the mask table comprises a first bottom connecting part, a first top connecting part and a first flexible sheet, wherein two sides of the first flexible sheet are respectively connected with the first bottom connecting part and the first top connecting part, the first top connecting part is connected with the mask table base, and the first bottom connecting part is connected with the projection objective sleeve;

the second support assembly includes: the mask stage comprises a first bottom connecting part, a first top connecting part and a first flexible sheet, wherein two sides of the first flexible sheet are respectively connected with the first bottom connecting part and the first top connecting part;

the third support assembly includes: the mask stage comprises a mask stage base, a first bottom connecting part, a first top connecting part and a first flexible sheet, wherein the two sides of the first flexible sheet are respectively connected with the first bottom connecting part and the first top connecting part;

viewed in the top view of the connection device:

the flexible piece is characterized in that a first connecting line is formed by extending along the length direction of the first flexible piece, a second connecting line is formed by extending along the length direction of the second flexible piece, a third connecting line is formed by extending along the length direction of the third flexible piece, and an isosceles triangle passing through the first flexible piece, the second flexible piece and the third flexible piece is formed by enclosing the first connecting line, the second connecting line and the third connecting line, wherein the first connecting line forms the bottom side of the isosceles triangle, and the distance from the geometric center of the cross section of the first flexible piece to the geometric center of the cross section of the second flexible piece is equal to the distance from the geometric center of the cross section of the first flexible piece to the geometric center of the cross section of the third flexible piece.

2. The apparatus of claim 1, wherein the isosceles triangle has an apex angle of 60 ° to 120 °.

3. The apparatus of claim 2, wherein the isosceles triangle has an apex angle of 80 ° to 100 °.

4. The apparatus of claim 1, further comprising three connecting plates, wherein the three connecting plates are connected between the first top connecting portion and the mask stage base, the second top connecting portion and the mask stage base, and the third top connecting portion and the mask stage base, respectively, and wherein the areas of the three connecting plates are larger than the areas of the first top connecting portion, the second top connecting portion, and the third top connecting portion.

5. The apparatus of claim 1, wherein the first bottom connecting portion has a first positioning pin hole on a bottom surface thereof, the third bottom connecting portion has a second positioning pin hole on a bottom surface thereof, the first positioning pin hole is a circular hole, the second positioning pin hole is a kidney-shaped hole, and a positioning pin is disposed at a corresponding position on the top surface of the projection objective sleeve.

6. The apparatus of claim 1, wherein the geometric center of the mask stage base, the geometric center of the isosceles triangle, and the central axis of the projection objective sleeve are located on a straight line.

7. The apparatus of claim 1, wherein the ratio of the thicknesses of the first, second and third flexible sheets is 2: 1: 1, and the second flexible sheet and the third flexible sheet have the same structure.

8. The vibration isolation device for mask stage of photolithography machine according to claim 7, wherein the first flexible sheet has a thickness of 2 to 4mm, and the second flexible sheet and the third flexible sheet each have a thickness of 1 to 2 mm.

9. The apparatus of claim 1, wherein the connecting means is made of spring steel, stainless steel or invar steel.

10. The apparatus of claim 1, wherein the first bottom connecting portion and the first top connecting portion are arranged vertically in a horizontal direction, the second bottom connecting portion and the second top connecting portion are arranged vertically in a horizontal direction, and the third bottom connecting portion and the third top connecting portion are arranged vertically in a horizontal direction.

Technical Field

The invention relates to the field of vibration suppression, in particular to a mask table vibration isolation device of a photoetching machine.

Background

In the development of the Integrated Circuit (IC) industry, photolithography has played a vital role. The typical lithography machine integrates ultra-precise measurement, motion control technology and lithography technology, and realizes the function of exposing a chip pattern on a mask plate to a silicon wafer on a workpiece table. In a stepper, a mask table exposes and etches a mask pattern on a wafer through a light source illumination system, a projection objective and a workpiece table, wherein a mask table system base is rigidly connected directly to the top of a projection objective sleeve. In the working process of the mask table of the photoetching machine, fine vibration generated by the mask table in high-speed and high-acceleration motion easily causes deviation of the alignment position between the mask table and a projection objective connected with the mask table, and the photoetching quality of a subsequent wafer can be directly influenced even if the mask table is extremely slightly deviated due to the nanometer level precision of the photoetching machine. In order to eliminate the influence of vibration factors on the movement and positioning accuracy of the mask stage of the photoetching machine, the support device for connecting the base of the mask stage system and the top of the projection objective sleeve is required to have vibration isolation and support functions. However, in the prior art, there is no vibration isolation support device specially designed for the connection between the mask stage system base and the top of the projection objective sleeve.

Disclosure of Invention

The utility model aims at providing a lithography machine mask platform vibration isolation mounting, it not only can support the stable fixing of mask platform base on the projection objective sleeve, can realize the vibration isolation of mask platform horizontal direction moreover to improve photoetching quality and precision.

The purpose of the application is realized by the following technical scheme:

a mask stage vibration isolation device of a lithography machine, comprising: a mask stage base, a projection objective sleeve, and a connecting device connecting the mask stage base and the projection objective sleeve;

connecting device includes first supporting component, second supporting component and third supporting component, first supporting component second supporting component and third supporting component are in the coplanar, first supporting component includes: the mask table comprises a first bottom connecting part, a first top connecting part and a first flexible sheet, wherein two sides of the first flexible sheet are respectively connected with the first bottom connecting part and the first top connecting part, the first top connecting part is connected with the mask table base, and the first bottom connecting part is connected with the projection objective sleeve;

the second support assembly includes: the mask stage comprises a first bottom connecting part, a first top connecting part and a first flexible sheet, wherein two sides of the first flexible sheet are respectively connected with the first bottom connecting part and the first top connecting part;

the third support assembly includes: the mask stage comprises a mask stage base, a first bottom connecting part, a first top connecting part and a first flexible sheet, wherein the two sides of the first flexible sheet are respectively connected with the first bottom connecting part and the first top connecting part;

viewed in the top view of the connection device:

the flexible piece is characterized in that a first connecting line is formed by extending along the length direction of the first flexible piece, a second connecting line is formed by extending along the length direction of the second flexible piece, a third connecting line is formed by extending along the length direction of the third flexible piece, and an isosceles triangle passing through the first flexible piece, the second flexible piece and the third flexible piece is formed by enclosing the first connecting line, the second connecting line and the third connecting line, wherein the first connecting line forms the bottom side of the isosceles triangle, and the distance from the geometric center of the cross section of the first flexible piece to the geometric center of the cross section of the second flexible piece is equal to the distance from the geometric center of the cross section of the first flexible piece to the geometric center of the cross section of the third flexible piece.

In some embodiments of the present application, the vertex angle of the isosceles triangle is 60 ° to 120 °.

In some embodiments of the present application, the vertex angle of the isosceles triangle is 80 ° to 100 °.

In some embodiments of the present application, the mask stage further comprises three connecting plates, three of the connecting plates are respectively connected between the first top connecting portion and the mask stage base, between the second top connecting portion and the mask stage base, and between the third top connecting portion and the mask stage base, and the area of the three connecting plates is greater than the area of the first top connecting portion, the second top connecting portion and the third top connecting portion.

In some embodiments of this application, be equipped with first locating pin hole on the bottom surface of first bottom connecting portion, be equipped with second locating pin hole on the bottom surface of third bottom connecting portion, just first locating pin hole is the circular port, the second locating pin hole is waist shape hole, the relevant position of the telescopic top surface of projection objective is equipped with the locating pin.

In some embodiments of the present application, the geometric center of the mask stage base, the geometric center of the isosceles triangle and the central axis of the projection objective sleeve lie on a straight line.

In some embodiments of the present application, a thickness ratio of the first flexible sheet, the second flexible sheet, and the third flexible sheet is 2: 1: 1, and the second flexible sheet and the third flexible sheet have the same structure.

In some embodiments of the present application, the thickness of the first flexible sheet is 2 ~ 4mm, the thickness of the second flexible sheet and the third flexible sheet is 1 ~ 2 mm.

In some embodiments of the present application, the material of the connecting means is spring steel, stainless steel or invar steel.

In some embodiments of the present application, the first bottom connection portion and the first top connection portion are vertically arranged in a horizontal direction, the second bottom connection portion and the second top connection portion are vertically arranged in a horizontal direction, and the third bottom connection portion and the third top connection portion are vertically arranged in a horizontal direction.

Compared with the prior art, the mask table vibration isolation device of the photoetching machine has the beneficial effects that: the utility model provides a lithography machine mask platform vibration isolation mounting sets up connecting device between mask platform base and projection objective sleeve, change traditional rigid connection into flexonics, top connecting portion, flexible piece and bottom connecting portion that from the top down set gradually in through connecting device, and adopt the support point to be the form that isosceles triangle arranged and couple together mask platform base and projection objective sleeve, it is steady reliable to support, and the connecting device of flexible piece structure has the characteristic of low rigidity even zero rigidity in mask platform horizontal direction, and then play the vibration isolation effect in mask platform horizontal direction.

Drawings

FIG. 1 is a schematic view of the overall structure of the present solution;

FIG. 2 is a bottom view of the connector assembly of the present embodiment;

FIG. 3 is a schematic view of the arrangement of the flexible sheets in the plan view direction of the present solution;

FIG. 4 is a front view of the first support assembly of the present solution;

FIG. 5 is a left side view of the first support assembly of the present solution;

FIG. 6 is a top view of the first support assembly of the present solution;

FIG. 7 is a perspective view of a first support assembly of the present solution;

FIG. 8 is a front view of a second support assembly of the present solution;

FIG. 9 is a left side view of the second support assembly of the present solution;

FIG. 10 is a top view of the second support assembly of the present solution;

FIG. 11 is a perspective view of a second support assembly of the present solution;

FIG. 12 is a front view of a third support assembly of the present solution;

FIG. 13 is a left side view of the third support assembly of the present solution;

FIG. 14 is a top view of a third support assembly of the present solution;

fig. 15 is a perspective view of a third support assembly of the present solution.

In the figure, 1, a mask stage base; 2. a connecting device; 21. a first support assembly; 211. a first bottom connection portion; 212. a first flexible sheet; 2121. a first connecting line; 213. a first top connection portion; 22. a second support assembly; 221. a second bottom connection portion; 222. a second flexible sheet; 2221. a second connecting line; 223. a second top connection portion; 23. a third support assembly; 231. a third bottom connection portion; 232. a third flexible sheet; 2321. a third connecting line; 233. a third top connection portion; 3. a projection objective sleeve; 4. a connecting plate; 5. a first dowel hole; 6. a second dowel hole.

Detailed Description

The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

In the description of the present application, it should be understood that the terms "bottom," "top," "center," and the like, as used herein, are used to indicate an orientation or positional relationship based on that shown in the drawings, merely to facilitate the description of the invention and to simplify the description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

As shown in fig. 1 to 15, an embodiment of the present application provides a mask stage vibration isolation device for a lithography machine, including: a mask table base 1, a projection objective sleeve 3, and a connecting device 2 connecting the mask table base 1 and the projection objective sleeve 3;

the connecting device comprises a first supporting component 21, a second supporting component 22 and a third supporting component 23, the first supporting component 21, the second supporting component 22 and the third supporting component 23 are positioned on the same plane, and the first supporting component 21 comprises: the mask stage comprises a first bottom connecting part 211, a first top connecting part 213 and a first flexible sheet 212, wherein two sides of the first flexible sheet 212 are respectively connected with the first bottom connecting part 211 and the first top connecting part 213, the first top connecting part 213 is connected with the mask stage base 1, and the first bottom connecting part 211 is connected with the projection objective sleeve 3;

the second support member 22 includes: a second bottom connection part 221, a second top connection part 223 and a second flexible sheet 222, wherein two sides of the second flexible sheet 222 are respectively connected with the second bottom connection part 221 and the second top connection part 223, the second top connection part 223 is connected with the mask stage base 1, and the second bottom connection part 221 is connected with the projection objective sleeve 3;

the third support assembly 23 includes: a third bottom connection part 231, a third top connection part 233 and a third flexible sheet 232, wherein two sides of the third flexible sheet 232 are respectively connected with the third bottom connection part 231 and the third top connection part 233, the third top connection part 233 is connected with the mask stage base 1, and the third bottom connection part 231 is connected with the projection objective sleeve 3;

viewed in the top view of the connecting device 2:

a first connecting line 2121 is formed by extending along the length direction of the first flexible sheet 212, a second connecting line 2221 is formed by extending along the length direction of the second flexible sheet 222, and a third connecting line 2321 is formed by extending along the length direction of the third flexible sheet 232, and the first connecting line 2121, the second connecting line 2221 and the third connecting line 2321 are enclosed to form an isosceles triangle passing through the first flexible sheet 212, the second flexible sheet 222 and the third flexible sheet 232, wherein the first connecting line 2121 forms the base of the isosceles triangle, and the distance from the geometric center of the cross section of the first flexible sheet 212 to the geometric center of the cross section of the second flexible sheet 222 is equal to the distance from the geometric center of the cross section of the first flexible sheet 212 to the geometric center of the cross section of the third flexible sheet 232.

Based on the above technical scheme, increase connecting device 2 between mask platform base 1 and projection objective sleeve 3 to connecting device 2 includes the three flexible piece of vertical placing, thereby changes mask platform base 1 and projection objective sleeve 3 original rigid connection into flexible connection, reaches the effect of damping. Meanwhile, the length extension directions of the three flexible sheets can form an isosceles triangle structure, wherein the first flexible sheet 212 is located at the vertex position of the isosceles triangle, and the second flexible sheet 222 and the third flexible sheet 232 are respectively located at two base points of the isosceles triangle.

The principle of negative stiffness vibration isolation is explained, and according to the vibration theory, the mode of the transfer function of passive vibration isolation displacement to displacement in vibration is as follows:

where ω is the vibration frequency, ω_nIs the natural frequency of the object and is,ε is the damping ratio, k is the stiffness of the object, and m is the mass of the object.

According to the formula (1), whenAnd the vibration isolation effect is achieved, so that the natural frequency of the object only needs to be reduced, namely the rigidity k of the object only needs to be reduced if a good vibration damping effect is achieved.

For the first support assembly 21, the second support assembly 22 and the third support assembly 23, the first flexible sheet 212, the second flexible sheet 222 and the third flexible sheet 232 can be simplified into euler strut models with two fixed ends, and then the horizontal stiffness theoretical model is as follows:

k＝6EI[1-(p/p_cr)]/l³ (2)

wherein p is_cr＝4π²EI/l²The critical load of the leaf spring, E is the elastic modulus of the flexible sheet, I is the cross section inertia moment of the center of the flexible sheet, l is the axial length of the flexible sheet, and p is the axial load borne by the flexible sheet.

As can be seen from equation (2), when the flexible sheet is subjected to an axial load greater than the critical load (p)>p_cr) Shi, RouThe horizontal rigidity of the sexual sheet is negative rigidity, and at the moment, the horizontal natural frequency of the object is low, so that the vibration isolation effect is good in the horizontal direction.

According to the description, the mask table of the photoetching machine adopts the connecting device 2, and the vibration of the mask table base 1 in the horizontal direction can be reduced through the horizontal negative rigidity characteristic of the connecting device 2, the flexible deformation generated by vibration impact and the stable support of the isosceles triangle installation layout, so that the positioning and movement errors caused by the horizontal direction motion impact and the vibration of the mask table in high-speed and high-acceleration motion are reduced, and the photoetching precision of the photoetching machine is guaranteed.

In some embodiments of the present application, as shown in fig. 1 to 3, the vertex angle of the isosceles triangle is 60 ° to 120 °, that is, the two base angles of the isosceles triangle are 30 ° to 60 °, and this angular arrangement makes the position layout of the three flexible sheets more reasonable, and the geometric center of the isosceles triangle is set as the origin, the straight line passing through the origin and parallel to the first connecting line 2121 is set as the Y axis, and the direction in which the origin extends toward the third flexible sheet 232 is the positive direction of the Y axis; the perpendicular bisector of the isosceles triangle passing through the vertex is set as an X axis, and the direction in which the origin extends to the vertex of the isosceles triangle is the positive direction of the X axis. When the vertex angle of the isosceles triangle is 60 degrees, the vibration isolation effect in the Y-axis direction is obviously stronger than that in the X-axis direction; when the vertex angle of the isosceles triangle is 120 degrees, the vibration isolation effect in the X-axis direction is obviously stronger than that in the Y-axis direction. Because the photoetching machine may have a problem of large vibration in a certain direction in the working process, the vibration isolation effect of the photoetching machine in the certain direction can be changed by adjusting the angle.

Preferably, the vertex angle of isosceles triangle is 80 ~ 100, and two base angles of isosceles triangle are 40 ~ 50 promptly, and the epaxial vibration isolation effect of X axle and Y tends towards the balance this moment, and more preferably, the vertex angle of isosceles triangle is 90, and two base angles of isosceles triangle are 45, and the epaxial vibration isolation effect of X axle and Y is complete balance basically this moment, and the vibration isolation effect is better, and the arrangement position of three flexible piece is also more reasonable, supports stably.

In some embodiments of the present application, as shown in fig. 1 and 2, the mask stage further includes three connection plates 4, the three connection plates 4 are respectively disposed between the first top connection portion 213 and the mask stage base 1, between the second top connection portion 223 and the mask stage base 1, and between the third top connection portion 233 and the mask stage base 1, and the areas of the three connection plates 4 are all larger than the areas of the first top connection portion 213, the second top connection portion 223, and the third top connection portion 233. Mask platform base 1 of lithography machine generally is the granite material, and flexible supporting component is stainless steel usually, because stainless steel's hardness is far greater than the granite, the lug connection causes the granite material of junction damaged very easily, so need set up connecting plate 4 between mask platform base 1 and flexible supporting component, and the area of three connecting plate 4 will be greater than first top connecting portion 213 respectively, the area of second top connecting portion 223 and third top connecting portion 233, with increase area of contact, avoid contact stress too big damage that causes mask platform base 1, thereby protection mask platform base 1.

Preferably, the hardness of the material of the connecting plate 4 is between the hardness of the material of the mask stage base 1 and the hardness of the material of the first top connecting portion 213, the second top connecting portion 223 and the third top connecting portion 233, and the material with the hardness between the two is adopted, so that transition and buffering effects are achieved between the mask stage base 1 and the three top connecting portions, and the mask stage base 1 can be better protected.

In some embodiments of the present application, as shown in fig. 2, a first positioning pin hole 5 is disposed on the bottom surface of the first bottom connecting portion 211, a second positioning pin hole 6 is disposed on the bottom surface of the third bottom connecting portion 231, the first positioning pin hole 5 is a circular hole, the second positioning pin hole 6 is a kidney-shaped hole, a positioning pin is disposed at a corresponding position of the top surface of the projection objective sleeve 3, since the distance between the first supporting component 21, the second supporting component 22 and the third supporting component 23 is relatively large, and the layout of the three components requires a strict isosceles triangle relationship, the positioning is realized through the first positioning pin hole 5 and the second positioning pin hole 6. Firstly, mounting a positioning pin on a pin hole position at the top of a projection objective sleeve 3, then placing a mask table base 1 on which a connecting device 2 is mounted above the projection objective sleeve 3, wherein a first positioning pin hole 5 on the bottom surface of a first bottom connecting part 211 is aligned with the positioning pin, and the first positioning pin hole 5 is a circular hole, the shape of which is matched with the positioning pin, so that accurate positioning can be realized; the second positioning pin hole 6 in the bottom surface of the third bottom connecting part 231 is a waist-shaped hole, and the diameter of the semicircle on the waist-shaped hole is matched with the positioning pin, so that the positioning pin can move along the length direction of the waist-shaped hole, and the problem that the positioning pin and the second positioning pin hole 6 are staggered and cannot be installed due to processing or installation errors is solved; the second supporting component 22 is not provided with a positioning pin hole, and in the actual installation process, the second supporting component 22 can be installed after the first supporting component 21 and the third supporting component 23 are installed, so that the installation error and the machining error of the first supporting component 21 and the third supporting component 23 are compensated, and the fact that the three supporting components can be assembled into the whole system is guaranteed.

In some embodiments of the present application, as shown in fig. 1, the geometric center of the mask stage base 1, the geometric center of the isosceles triangle, and the central axis of the projection objective sleeve 3 are located on a straight line, the centers of the three are located on a straight line, so that the lithography precision can be ensured, and the three-point support of the isosceles triangle is more stable.

In some embodiments of the present application, as shown in fig. 3, the ratio of the thickness of the first flexible sheet 212, the second flexible sheet 222, and the third flexible sheet 232 is 2: 1: 1, the second flexible sheet 222 and the third flexible sheet 232 have the same structure, and the thickness ratio can ensure that the bearing areas of the three flexible sheets are symmetrically equal in the directions of the X axis and the Y axis, as shown in fig. 3, firstly, the bearing areas of the flexible sheets are symmetrically equal in a certain direction on the X axis, and the projection areas of the flexible sheets on the direction need to be compared, and since the X axis passes through the perpendicular bisector of an isosceles triangle, the projection areas of the flexible sheets on the X axis on the two sides of the X axis are necessarily symmetrically equal; then, the Y axis is provided, the left side of the Y axis is provided with the first flexible sheet 212, and the right side of the Y axis is provided with the second flexible sheet 222 and the third flexible sheet 232, and since the thickness of the first flexible sheet 212 is twice that of the second flexible sheet 222 and the third flexible sheet 232, the projection area of the first flexible sheet 212 on the Y axis is equal to the sum of the projection areas of the second flexible sheet 222 and the third flexible sheet 232 on the Y axis. Because the bearing areas in the X-axis direction and the Y-axis direction are symmetrical and equal, the whole device is stressed evenly and supported stably.

Specifically, the thickness of the first flexible sheet 212 is 2-4 mm, and the thicknesses of the second flexible sheet 222 and the third flexible sheet 232 are both 1-2 mm, and the basis for selecting the thicknesses of the flexible sheets is described herein, first, in order to realize stable and reliable support, according to the material axial tension and compression allowable stress specification in material mechanics, the strength of the bearing section of the flexible sheet during operation is required to be within the allowable stress, and if a single flexible sheet is taken to support the limit condition of the whole mask table, the cross-sectional area of the flexible sheet is as follows:

A≥F_N,max*[σ]＝G_max/[σ] (3)

wherein, A ═ d × l is the minimum cross-sectional area allowed by the flexible sheet, d is the thickness of the flexible sheet, and l is the length of the flexible sheet; f_N,maxFor maximum load force, G_maxMaximum weight of mask table, [ sigma ]]Is the allowable stress of the material.

A mask stage of a general lithography machine generally weighs between 30kg and 90kg, a mask stage with a mass of 90kg is taken as a supporting object, 304 stainless steel is selected as a flexible sheet material, allowable stress of the 304 stainless steel is [ σ ] ═ 137MPa, as shown in fig. 4 to 15, as example data, the first flexible sheet 212 has a length of 40mm, a width of 15mm, and a thickness of 3mm, the second flexible sheet 222 and the third flexible sheet 232 have a length of 56.57mm, a width of 15mm, and a thickness of 1.5mm, and when the second flexible sheet 222 or the third flexible sheet 232 with a smaller bearing area is taken as a limit of supporting by a single flexible sheet, the minimum thickness of the second flexible sheet 222 or the third flexible sheet 232 is known from equation (3):

d≥G_max/([σ]·l) (4)

from the equation (4), the minimum value of the thickness of the second flexible sheet 222 or the third flexible sheet 232 is 0.14mm, and the thickness range of 1 mm-2 mm in the present scheme is much higher than the minimum thickness requirement, and meets the design requirement.

In some embodiments of the present application, the material of the connecting device 2 is spring steel, stainless steel or invar steel, and these materials have the advantages of long service life, high fatigue strength, small thermal deformation, high stability, good corrosion resistance, and the like, and are easy to obtain, and are particularly suitable for being used as a structural material of a flexible support.

In some embodiments of the present application, as shown in fig. 4 to 15, the first bottom connecting portion 211 and the first top connecting portion 213 are vertically arranged in the horizontal direction, the second bottom connecting portion 221 and the second top connecting portion 223 are vertically arranged in the horizontal direction, and the third bottom connecting portion 231 and the third top connecting portion 233 are vertically arranged in the horizontal direction, so that the bearing stress of the support assembly in the orthogonal direction in the horizontal plane is uniform.

In addition, besides the flexible sheet structure, the scheme can also use a round-notch flexible hinge, a hyperbolic flexible hinge, a parabolic flexible hinge, a reverse parabolic flexible hinge, a secant flexible hinge or a hyperbolic cosine flexible hinge, and can also realize the vibration isolation and support functions of the scheme.

In conclusion, the vibration isolation device for the mask table of the lithography machine is provided with the connecting device 2 between the mask table base 1 and the projection objective sleeve 3, the traditional rigid connection is changed into flexible connection, the top connecting part, the flexible sheet and the bottom connecting part are sequentially arranged from top to bottom in the connecting device 2, the mask table base 1 and the projection objective sleeve 3 are connected in an isosceles triangle arrangement mode through supporting points, the supporting is stable and reliable, the connecting device 2 with the flexible sheet structure has the characteristic of low rigidity or even zero rigidity in the horizontal direction of the mask table, and the vibration isolation effect is achieved in the horizontal direction of the mask table.

The foregoing is only a preferred embodiment of the present application, and it should be noted that, for those skilled in the art, several modifications and substitutions can be made without departing from the technical principle of the present application, and these modifications and substitutions should also be regarded as the protection scope of the present application.