WO2018120105A1

WO2018120105A1 - Optical element supporting device and optical system comprising same

Info

Publication number: WO2018120105A1
Application number: PCT/CN2016/113692
Authority: WO
Inventors: 彭海峰; 杨怀江; 隋永新; 倪明阳; 李显凌
Original assignee: 中国科学院长春光学精密机械与物理研究所
Priority date: 2016-12-30
Filing date: 2016-12-30
Publication date: 2018-07-05

Abstract

An optical element supporting device and an optical system. The supporting device comprises an outer frame (2), at least three supporting elastic sheets (3), and a drive element (5). Each supporting elastic sheet comprises a first end and a second end. The first end is fixed to the outer frame (2), and the second end is configured to support an optical element. The drive element (5) is disposed on each supporting elastic sheet (3). The drive element (5) is configured to provide a drive force to the supporting the elastic sheet (3), and indirectly adjust a supporting force of the supporting the elastic sheet (3) to the optical element. Surface form adjustment is taken into consideration, the force applied to the optical element in a supported state is uniform as far as possible, and the surface form of the optical element when the optical element is heated and deformed is small, and the impact of the supporting force to the surface form of the optical element can be effectively reduced.

Description

Optical element supporting device and optical system including the same

Technical field

The present invention relates to the field of optics, and further to an optical element supporting device, and an optical system including the same.

Background technique

At present, the most advanced projection lithography objective lens in the world contains more than 20 components (including aspherical components and reflective components), and the full field of view (26mm × 8mm) wave aberration is better than 1nm (RMS), which can achieve less than 25nm Exposure copy of the node. As the most sophisticated and complex optical system in the world, the 193nm (ArF) projection exposure system involves a wide range of cutting-edge disciplines, whether it is the early system design, manufacturing, or post-system integration.

In the optical system, especially the projection lithography objective lens has extremely high requirements on optical processing accuracy, and is about 1 to 2 nm. Therefore, the repeatability of the optical component detection is very high, and the optical component is required to be subjected to the process of being supported by the tool. Minimize the impact of support and at the same time require fine-tuning the position of the optics. Generally, the rigid clamping method is difficult to achieve these requirements at the same time, so it is necessary to apply a flexible support method including adjustable support force in optical component detection.

Summary of the invention

An object of the present invention is to provide an optical element supporting device and an optical system including the same to solve at least one of the above technical problems.

To achieve the above object, the present invention provides an optical component supporting device comprising: an outer frame;

At least three supporting elastic pieces, each supporting elastic piece including a first end and a second end, the first end is fixed to the outer frame, the second end is configured to support the optical component, and the driving component is disposed on each support On the elastic piece, the driving element is configured to provide a driving force to the supporting elastic piece, and indirectly adjust the supporting force of the supporting elastic piece to the optical element.

Further, each of the supporting elastic pieces is provided with two driving elements respectively located on the upper side and the lower side of the supporting elastic piece, and the two driving elements are arranged to drive the supporting elastic pieces simultaneously or non-simultaneously.

Further, the first end of the supporting elastic piece is fixed to the upper surface of the outer frame by riveting.

Further, the outer frame includes the same number of bosses as the supporting elastic piece, and the first end of the supporting elastic piece is fixed on the protruding base.

Further, the boss defines a screw hole, and the screw passes through the first end of the supporting elastic piece and is riveted into the screw hole.

Further, the supporting elastic piece is a bifurcated structure, and further includes a third end, and the third end is configured to connect the driving element.

Further, the outer frame includes the same number of bosses as the supporting elastic piece, the protruding frame is located at a side of the outer frame, the first end of the supporting elastic piece is fixed on the protruding frame, and the driving component is also disposed at On the boss.

Further, the material of the supporting elastic piece is silicon steel, manganese steel, silicon manganese steel, stainless steel, phosphor bronze or beryllium bronze, or a combination of the above materials.

Further, the driving component is an electrostatic, magnetostrictive driving or piezoelectric driving component.

According to another aspect of the invention, there is provided an optical system comprising any of the above-described devices, characterized in that the system is an optical component detection support system, or a precision optical instrument optomechanical system.

Through the technical solution described above, the support device of the present invention takes into account the precise fretting adjustment and makes the optical component as uniform as possible under the detected state, thereby effectively reducing the influence of the adjustment force on the surface shape of the optical component; avoiding mechanical clamping Trilobal aberrations and astigmatism that occur when the lens is present.

DRAWINGS

1 is a schematic view of an optical component supporting device according to an embodiment of the invention;

2 is a schematic structural diagram of an outer frame according to an embodiment of the present invention;

FIG. 3 is an assembly diagram of an embodiment of a supporting elastic piece and a driving element according to an embodiment of the present invention; Drawing

Figure 4 is a cross-sectional view of Figure 3;

5 is an assembly relationship diagram of another embodiment of a supporting elastic piece and a driving element according to an embodiment of the present invention;

Figure 6 is a cross-sectional view of Figure 5;

Figure 7 is a schematic view showing the deformation of a supporting elastic piece according to another embodiment of the present invention;

Figure 8 is a schematic illustration of an optical system in accordance with an embodiment of the present invention.

[Description of the reference signs]:

1 optical component

2 frame

201 boss

202 screw hole

3 support shrapnel

First end of 301

302 second end

303 third end

4 screws

5 drive components

501 piezoelectric driver

502 piezoelectric driver

6 screws

A interferometer

B inspection tooling and components

C five-dimensional adjustment frame

D support bottom plate

E interferometer air flotation platform

detailed description

The present invention will be further described in detail below with reference to the specific embodiments of the invention, In the description, the same or similar reference numerals indicate the same or similar parts. The description of the embodiments of the present invention with reference to the accompanying drawings is intended to illustrate the general inventive concept of the invention, and should not be construed as a limitation of the invention.

In the following detailed description, numerous specific details are set forth Obviously, however, one or more embodiments may be practiced without these specific details. In other instances, well-known structures and devices are shown in the drawings in the drawings.

According to the basic idea of the present invention, as shown in FIG. 1, an optical component supporting apparatus is provided, including:

The outer frame 2; at least three supporting elastic pieces 3, each supporting elastic piece 3 includes a first end and a second end, the first end is fixed to the outer frame 2, the second end is configured to support the optical element; and the driving element 5 Provided on each of the supporting elastic pieces 3, the driving element 5 is configured to provide a driving force to the supporting elastic piece 3, and indirectly adjust the supporting force of the supporting elastic piece 3 to the driving optical element 1.

The principle of the present invention is that when the supporting elastic piece 3 supports the optical element (for example, the lens), the supporting elastic piece 3 is deformed to give a reaction force to the optical element; when the micro-motion adjustment is required, the driving element 5 on each supporting elastic piece is deformed to drive the supporting elastic piece. Deformation occurs to change the supporting force of each supporting elastic piece 3 acting on the optical element 1, so that the optical element reaches an ideal supporting state, and the surface shape is optimal.

FIG. 2 is a schematic structural diagram of an outer frame according to an embodiment of the present invention. The outer frame 2 in the embodiment of the present invention may be in various practical forms according to the specific system to which the supporting device is applied, and is mainly used as an indirect supporting member of the optical component for fixing the supporting elastic piece 3, thereby indirectly supporting the elastic piece 3. The optical element 1 carried above. The outer frame 2 may specifically be a frame for carrying and observing optical components such as lenses. The shape of the outer frame 2 includes, but is not limited to, a circular ring, a rectangular shape, or an elliptical ring shape.

Optionally, a number of bosses 201 are also disposed on the outer frame for achieving a fixed connection with the supporting elastic piece 3, that is, connected to the first end of the supporting elastic piece 3. Connection method can be There are various fixed connection methods used in the technology (such as welding or riveting, the joint is a finishing surface, the two sides are completely bonded after welding, and the side is welded, then the weld is repaired; the screw is tightened A preferred embodiment is a riveting manner. The boss 201 is provided with a screw hole 202. The screw passes through the first end of the supporting elastic piece 3 and the screw hole, so that the first end of the supporting elastic piece is fixed to the convex portion. Taiwan 201. The number of the bosses 201 may be the same as the number of the supporting elastic pieces 3. For example, each of the bosses 201 corresponds to one supporting elastic piece 3, and the boss 201 may be evenly distributed on the outer frame 2, and the outer frame 2 may have a circular outer shape. The corresponding bosses 201 can be equiangularly distributed on the outer frame, and the supporting elastic pieces 3 can also be equiangularly distributed on the annular structure. The boss 201 may be disposed on the upper surface of the outer frame or on the side of the annular outer frame.

Referring to FIG. 1 and FIG. 3, the supporting elastic piece 3 in the embodiment of the present invention mainly plays a supporting role, and can be deformed under the driving of the driving element 5 to realize the fine adjustment of the supported optical element 1. It comprises at least a first end fixedly connected to the outer frame 2, and the connection relationship of the first end is as described above. The first end may have a curved surface to match the shape of the optical element 1 to better achieve the supporting effect. The support dome 3 may also include a second end for supporting the optical element, the second ends of the plurality of support domes 3 collectively supporting the optical element 1 to maintain the optical element horizontal.

The material supporting the elastic piece 3 first needs to have a certain rigidity to support the optical element 1, and further, it is also required to be elastic to generate elastic deformation to finely adjust the optical element 1. The material of the supporting elastic piece 3 may be silicon steel, manganese steel, silicon manganese steel, stainless steel, phosphor bronze or beryllium bronze, or a combination of the above materials. Of course, the choice of material is not limited thereto, and other materials which can satisfy the above-mentioned supporting optical element 1 and the prior art which forms elastic deformation, for example, when the optical element is light, elastic deformation can be selected. A relatively low plastic is used as a supporting shrapnel.

Depending on the manner in which the supporting elastic piece 3 and the driving element 5 are arranged, the supporting elastic piece 3 may or may not have a third end, and the specific arrangement will be explained in the following description of the driving element 5 and in the description of the specific embodiment.

The driving element 3 in the embodiment of the present invention is used to provide a precision driving force to the supporting elastic piece 3, indirectly adjust the supporting elastic piece 3 to support the driving optical element, and change the position of the optical element 1. Two driving elements 5 may be disposed on each of the supporting elastic pieces 3, respectively located on the supporting elastic piece 3 On the upper side and the lower side, the two drive elements are arranged to drive the support domes 3 simultaneously or non-simultaneously, each drive element 5 being individually controllable.

As an embodiment of the driving element 5, as shown in Figures 3 and 4, the driving element comprises an upper driving element 501 and a lower driving element 502, each driving element being combined with a corresponding side surface (for example, by means of pasting (must be pressed before pasting) The electric drive piece is subjected to the corresponding surface treatment and cleaning. It is wiped clean with the anhydrous alcohol on the adhesive surface. It must be successful once in the pasting, otherwise it will affect the pasting effect and even seriously affect the deformation efficiency of the pressure-driven component. 5 Piezoelectric driving piece can be used. For example, when the optical element needs to be adjusted downward, the supporting elastic piece 3 at the corresponding position of the driving element can be deformed downward, that is, the upper piezoelectric on the supporting elastic piece 3 can be driven. The driving piece produces a coupling deformation, and the reverse acting force of the deformation acts on the supporting elastic piece 3, so that corresponding adjustment can be achieved.

Another embodiment of the driving element 5 is shown in FIGS. 5-7. The driving element 5 can be disposed correspondingly for each supporting elastic piece 3. The supporting elastic piece 3 can in this case include a third end, the third end. In connection with the drive element 5, the boss 201 can be located on the side of the outer frame 2 in this embodiment, and the drive element 5 is also fixed to the boss 201. That is, the supporting elastic piece comprises a three-terminal integrated structure, the first end is fixedly connected with the boss 201, the second end is configured to support the optical element 1, and the third end is connected with the driving element 5.

The present invention is not limited to the above-described deformation of the piezoelectric driving piece driving support elastic piece, and it is also possible to adopt a precision driving method such as an electrostatic type or a magnetostrictive driving type and other precisions.

The following is a detailed description of the present invention. The present invention is not limited thereto, and those skilled in the art can base any of the components on the prior art. Changes, improvements or replacements of the various components of the device.

An embodiment of the present invention is described with reference to FIGS. 1-4. A support device for optical component detection in a projection objective development system includes an optical component 1 and an outer frame 2. In the present embodiment, a frame is used. The supporting elastic piece 3, the screw 4, and the driving element 5 are used in the present embodiment as a piezoelectric driving piece; the optical element 1 is placed on the supporting elastic piece 3; and the supporting elastic piece 3 is fixed to the frame by the screw 4. The material of the supporting elastic piece 3 may be stainless steel or spring steel after surface anti-rust treatment.

The piezoelectric driving piece 501 and the lower piezoelectric driving piece 502 are disposed above and below the supporting elastic piece.

And as shown in FIG. 2, the boss 201 and the screw hole 202 are arranged on the outer frame 2.

The device as a whole can be regarded as an optical element 1 supported by a plurality of supporting elastic pieces 3, and the supporting elastic piece 3 is placed on the frame frame boss 201 with good parallelism; the supporting elastic piece is kept in close contact with the lens. The supporting elastic piece 3 is bonded to the piezoelectric driving piece 5 on the upper and lower sides; when the structure supports the lens, the plurality of piezoelectric driving pieces drive the supporting elastic piece 3 according to the shape of the supported optical element 1 to be differently deformed according to the surface shape of the supported optical element 1, and each supporting The reaction force of the elastic piece 3 acts on the outermost ring surface of the optical element 1; when the micro-motion adjustment is required, the piezoelectric driving piece of each supporting elastic piece changes the force of the optical element 1 by the coupling deformation, and drives the optical element. 1 Achieve precise surface changes to achieve ultra-precise inspection of optical component profiles.

Another embodiment of the invention is illustrated in connection with Figures 1, 2 and 5-7, consisting of an optical element 1, an outer frame 2, a supporting spring 3, a screw 4, a drive element 5 and a screw 6.

In the present embodiment, the supporting elastic piece 3 is deformed by the driving element 5, for example, the piezoelectric actuator, thereby changing the surface shape of the optical element 1. The supporting elastic piece 3 is fixed to the outer frame 2' by a fixing screw 4 and a fixing screw 6, and the supporting elastic piece 3 and the piezoelectric actuator are bonded by an epoxy glue or other adhesive suitable for the spectrum of the optical system. The material supporting the shrapnel 3 can be selected from spring steel.

The piezoelectric actuator drives the third end 303 of the supporting elastic piece 3 to deform, thereby causing the first end 301 to be deformed, and the second end 302 of the supporting elastic piece is displaced, thereby changing the stress state of the optical element 1 so that the optical element 1 The corresponding deformation occurred.

Based on the same inventive concept, an embodiment of the present invention further provides an optical system including the above-described support device, which is an optical component detection support system or a precision optical instrument optomechanical system. Figure 8 is a schematic illustration of an optical system in accordance with an embodiment of the present invention. Specifically, the optical system may be an optical component detecting support system, including an interferometer A at the top, and a detecting tool B including the supporting device below the interferometer, wherein the optical component to be detected may be placed, and the inspection tool has a five-dimensional adjustment under the tooling. The frame C is used to adjust the five-dimensional position of the inspection tooling B. The lower part of the five-dimensional adjustment frame C is the interferometer air floating platform E at the bottom of the support bottom plate D. In this system, when the micro-motion adjustment optical element is required, the driving elements of each supporting elastic piece are deformed by coupling. The force of the lens is changed, and the optical component is driven to achieve precise surface change, so as to adapt to the high-precision control of the component surface type when the optical component is detected.

It should be noted that the structure described in the detection support device can also be applied to the support structure of the precision optical instrument to realize high-precision change of the surface shape of the optical component.

The invention combines the precise surface adjustment and makes the optical element as uniform as possible under the supported state and can change the surface shape when the element is thermally deformed, and can effectively reduce the influence of the supporting force on the surface shape of the optical element.

The specific embodiments of the present invention have been described in detail in the foregoing detailed description of the embodiments of the present invention. All modifications, equivalents, improvements, etc., made within the spirit and scope of the invention are intended to be included within the scope of the invention.

Claims

An optical component supporting device characterized by comprising:

Outer frame (2);

At least three supporting elastic pieces (3), each supporting elastic piece includes a first end and a second end, the first end is fixed to the outer frame (2), and the second end is configured to support the optical element;

The driving element (5) is disposed on each of the supporting elastic pieces (3), and the driving element (5) is configured to provide a driving force to the supporting elastic piece (3), and indirectly adjust the supporting force of the supporting elastic piece (3) to the optical element.
The device according to claim 1, characterized in that each of the supporting elastic pieces (3) is provided with two driving elements (5) respectively located on the upper side and the lower side of the supporting elastic piece (3), two driving The elements are arranged to drive the support domes (3) simultaneously or non-simultaneously.
The device according to claim 2, characterized in that the first end of the supporting elastic piece (3) is fixed to the upper surface of the outer frame by riveting.
The apparatus according to claim 1, wherein said outer frame comprises the same number of bosses as said supporting elastic piece, and said first end of said supporting elastic piece (3) is fixed to said boss.
The device according to claim 4, wherein the boss defines a screw hole, and the screw passes through the first end of the supporting elastic piece and is riveted into the screw hole.
The device according to claim 1, wherein the supporting elastic piece is a bifurcated structure, further comprising a third end, the third end being configured to connect the driving element.
The device according to claim 6, wherein the outer frame comprises the same number of bosses as the supporting elastic piece, the boss is located at a side of the outer frame, and the first end of the supporting elastic piece (3) is fixed at the outer side. On the boss, the drive element is also disposed on the boss.
The device according to claim 1, characterized in that the material of the supporting elastic piece (3) is silicon steel, manganese steel, silicon manganese steel, stainless steel, phosphor bronze or beryllium bronze, or a combination of the above materials.
Device according to claim 1, characterized in that the drive element (5) is an electrostatic, magnetostrictive or piezoelectric drive element.
An optical system comprising the apparatus of any of claims 1-9, wherein the system is characterized in that the system is an optical component detection support system, or a precision optical instrument optomechanical system.