CN104216237B - Lens eccentricity setting device in the photoetching projection objective lens of a kind of decoupling zero - Google Patents

Abstract

In the photoetching projection objective lens of decoupling zero, lens eccentricity setting device belongs to a lithographic projection manufacturing technology field, and object is to solve the problem of coupling nonlinear error, cost height and adjustment difficulty that prior art exists. The present invention comprises picture frame, sensor and driving mechanism; Picture frame comprises outer picture frame, interior picture frame, support seat, guiding hole, connecting thread hole, flexible guiding mechanism and flexible linking device; Picture frame entirety is circular ring structure, scope frame bottom is fixed with support seat, interior picture frame and outer picture frame running fit, interior picture frame and outer picture frame are connected by the n group flexible linking device of circumference uniform distribution, on circumferential direction, being provided with one group of flexible guiding mechanism between adjacent two flexible linking devices, outer picture frame and flexible guiding mechanism relative answer position to be provided with radial guiding hole, and two guiding holes about center of circle symmetry are respectively arranged with a driving mechanism and a sensor. The flexible leaf spring unit integral structure of the present invention, cost is low, reduces the coupling nonlinear error of orthogonal directions.

Description

A decoupled lens eccentricity adjustment device in lithography projection objective lens

technical field

The invention belongs to the technical field of lithography projection manufacturing, and in particular relates to a lens eccentricity adjusting device in a decoupled lithography projection objective lens.

Background technique

The precision requirements of deep ultraviolet lithography projection objective lenses used in the manufacture of large-scale integrated circuits are very high. However, during the assembly process, the performance of the lithography system will be degraded due to assembly stress, external vibration of the system, temperature changes, etc. In order to compensate part of the rotational asymmetry error caused by the above reasons, it can be compensated by adjusting the position of the lens in the projection objective lens, so it is necessary to design a special eccentric adjustment mechanism.

The Chinese patent with the publication number CN102162894 discloses a technical solution of an invention titled a centering device for optical elements in a projection objective lens. The device is divided into a macro-alignment module and a micro-alignment module. Large stroke alignment is realized by three screw micrometers. During micro-adjustment, two piezoelectric drivers acting on the flexible body of the frame drive the inner ring of the frame to move, thereby driving the optical elements to achieve precise micro-adjustment. According to the working principle of the mechanism, this method approximates the linear motion with the rotary motion of a small stroke. With the increase of the adjustment stroke, the coupling error in the orthogonal direction increases non-linearly, and the compensation difficulty increases.

The Chinese patent with the publication number CN102707404 discloses an invention titled a technical solution of an optical element XY-θ _Z three-degree-of-freedom micro-adjustment device. The set is based on a 3-RRR planar mechanism, including a mirror frame, three drivers and two sensors. The frame is an integrated structure, which is composed of an inner ring, an outer ring, and three motion branch chains, and the three motion branch chains are evenly distributed along the circumferential direction at 120°. The two sensors used in this device can only detect the translational motion in the XY two directions, and the θ _Z motion cannot be detected. Therefore, one driver in this scheme is designed redundantly, which increases the manufacturing cost on the one hand, and brings difficulties to the closed-loop decoupling control algorithm during displacement adjustment on the other hand.

Contents of the invention

The object of the present invention is to propose a decoupled lens eccentricity adjustment device in a lithographic projection objective lens, which solves the problems of coupling nonlinear error, high cost and difficult adjustment in the prior art.

In order to achieve the above object, the lens eccentricity adjustment device in a decoupled lithographic projection objective lens of the present invention includes a mirror frame, a sensor and a driver; Guiding mechanism and flexible connection mechanism;

The picture frame as a whole is a ring structure, the bottom of the inner picture frame is fixed with a support base, the inner picture frame and the outer picture frame are in clearance fit, and the inner picture frame and the outer picture frame are connected by n groups of flexible connection mechanisms uniformly distributed around the circumference, In the circumferential direction, a group of flexible guide mechanisms is arranged between two adjacent flexible connection mechanisms, and radial guide holes are provided on the corresponding positions of the outer mirror frame and the flexible guide mechanisms, and two guide holes that are symmetrical about the center of the circle are respectively provided with One driver and one sensor.

The n groups of flexible connection mechanisms specifically refer to 4 groups.

The flexible guide mechanism includes four parallelogram mechanisms with radial flexibility along the outer mirror frame and two compound quadrilateral mechanisms with tangential flexibility along the outer mirror frame; each parallelogram mechanism is connected by two flexible leaf springs. Composed of rigid links; each compound quadrilateral mechanism is composed of 6 flexible leaf springs connected to 5 movable rigid links.

The flexible connection mechanism is two Z-shaped flexible leaf springs.

A plurality of connection threaded holes are evenly distributed on the flange end surface of the outer mirror frame.

The number of the connecting threaded holes is 12.

The working principle of the present invention is as follows: the lens in the lens eccentricity adjustment device of a decoupled lithographic projection objective lens of the present invention is fixed on the support base by cementing, and the driver acts on the flexible guide mechanism to push the inner mirror frame to move, and then Drive the lens to produce eccentric movement. The flexible connection mechanism connects the inner mirror frame and the outer mirror frame and prevents the inner mirror frame from rotating during adjustment. The sensor detects the adjustment displacement of the inner mirror frame, and feeds back to the driver to form a closed-loop adjustment.

The beneficial effects of the present invention are: the lens eccentricity adjustment device in a decoupled lithography projection objective lens of the present invention adopts a structural design scheme of an integrated flexible leaf spring unit. On the one hand, the overall structure of the mirror frame is simple, compact, and low in cost. Improving the overall modality of the objective lens system plays an important role. On the other hand, the coupling motion error is eliminated from the design principle, and a high-precision eccentric adjustment device with motion decoupling is obtained. When adjusting in one direction in the horizontal plane, the ratio of the coupling displacement introduced in the orthogonal direction to the main motion displacement is less than 0.29%, and the ratio of the coupling displacement to the main motion displacement along the optical axis is less than 0.012%, which achieves the compensation effect of the optical system and further The performance of the optical system is improved, and the coupling error in the orthogonal direction is reduced.

Description of drawings

Fig. 1 is a schematic diagram of the overall structure of a lens eccentricity adjustment device in a decoupled lithography projection objective lens of the present invention;

FIG. 2 is a schematic diagram of the overall structure of the mirror frame in the lens eccentricity adjustment device in a decoupled lithographic projection objective lens of the present invention.

3 is a schematic diagram of a flexible guide mechanism in a lens eccentricity adjustment device in a decoupled lithography projection objective lens of the present invention;

4 is a schematic diagram of a parallelogram mechanism in a flexible guide mechanism in a lens eccentricity adjustment device in a decoupled lithographic projection objective lens of the present invention;

5 is a schematic diagram of a compound quadrilateral mechanism in a flexible guide mechanism in a lens eccentricity adjustment device in a decoupled lithographic projection objective lens of the present invention;

Fig. 6 is a structural schematic diagram of the flexible leaf spring unit in the flexible guide mechanism in the lens eccentricity adjusting device in a decoupled lithography projection objective lens of the present invention;

7 is a schematic diagram of a flexible connection mechanism in a lens eccentricity adjustment device in a decoupled lithography projection objective lens of the present invention;

8 is a schematic structural diagram of the Z-shaped flexible leaf spring in the flexible connection mechanism of the lens eccentricity adjustment device in a decoupled lithography projection objective lens of the present invention;

Among them: 1. lens, 2. outer mirror frame, 3. inner mirror frame, 4. support seat, 5. guide hole, 6. connecting threaded hole, 7. flexible guide mechanism, 701, rigid connecting rod a, 702, flexible leaf spring a, 703, flexible leaf spring b, 704, rigid connecting rod b, 705, rigid connecting rod c, 706, rigid connecting rod d, 707, flexible leaf spring c, 708, flexible leaf spring d, 709, flexible leaf spring e , 710, rigid connecting rod e, 711, rigid connecting rod f, 712, rigid connecting rod g, 713, flexible leaf spring f, 714, flexible leaf spring g, 715, flexible leaf spring h, 8, flexible connection mechanism, 801 , Z-shaped flexible leaf spring, 9, sensor, 10, driver.

detailed description

Embodiments of the present invention will be further described below in conjunction with the accompanying drawings.

Referring to accompanying drawing 1 and accompanying drawing 2, the lens eccentricity adjusting device in a kind of decoupling photolithography projection objective lens of the present invention comprises mirror frame, sensor 9 and driver 10; Described mirror frame comprises outer mirror frame 2, inner mirror frame 3, support seat 4 , guide hole 5, connecting threaded hole 6, flexible guiding mechanism 7 and flexible connecting mechanism 8;

The picture frame as a whole is a ring structure, the bottom of the inner picture frame 3 is fixed with a support seat 4, the support seat 4 and the lens 1 are cemented and fixed, the inner picture frame 3 and the outer picture frame 2 are in clearance fit, and the inner picture frame 3 and the outer mirror frame 2 are connected by n sets of flexible connecting mechanisms 8 uniformly distributed on the circumference. In the circumferential direction, a group of flexible guiding mechanisms 7 are arranged between two adjacent flexible connecting mechanisms 8. The outer mirror frame 2 and the flexible guiding mechanisms 7 Radial guide holes 5 are provided at corresponding positions, and two guide holes 5 symmetrical to the center of the circle are provided with a driver 10 and a sensor 9 respectively.

The n groups of flexible connection mechanisms 8 specifically refer to 4 groups.

Referring to accompanying drawing 3, accompanying drawing 4, accompanying drawing 5 and accompanying drawing 6, described flexible guiding mechanism 7 comprises four parallelogram mechanisms with radial flexibility along outer mirror frame 2 and two have along outer mirror frame 2 cuts It is a flexible compound quadrilateral mechanism; each parallelogram mechanism is composed of two flexible leaf springs connected to two rigid links, specifically: each flexible unit includes flexible leaf spring a702, flexible leaf spring b703, rigid link a701 and rigid The connecting rod b704, the flexible leaf spring a702 and the flexible leaf spring b703 are arranged in parallel, and the two ends are fixedly connected to the rigid connecting rod a701 and the rigid connecting rod b704 respectively;

Each compound quadrilateral mechanism is composed of 6 flexible leaf springs connected with 5 movable rigid links, specifically: each compound quadrilateral mechanism includes flexible leaf spring c707, flexible leaf spring d708, flexible leaf spring e709, flexible leaf spring f713 , flexible leaf spring g714, flexible leaf spring h715, rigid connecting rod c705, rigid connecting rod d706, rigid connecting rod e710, rigid connecting rod f711 and rigid connecting rod g712, the flexible leaf spring c707, flexible leaf spring d708, flexible plate Spring e709, flexible leaf spring f713, flexible leaf spring g714 and flexible leaf spring h715 are arranged in parallel, rigid link c705, rigid link d706, rigid link e710, rigid link f711 and rigid link g712 are arranged in parallel, and the flexible Both ends of leaf spring c707 and flexible leaf spring f713 are fixedly connected with rigid link d706 and rigid link f711 respectively, both ends of flexible leaf spring d708 are fixedly connected with rigid link c705 and rigid link e710 respectively, and both ends of flexible leaf spring g714 The two ends of the flexible leaf spring e709 are fixedly connected with the rigid link a701 and the rigid link e710 respectively, and the two ends of the flexible leaf spring h715 are respectively connected with the rigid link g712 and the rigid link a701 is fixed.

Referring to accompanying drawings 7 and 8, the flexible connection mechanism 8 is two Z-shaped flexible leaf springs 801 .

A plurality of connecting threaded holes 6 are evenly distributed on the flange end surface of the outer mirror frame 2 .

The number of the connecting threaded holes 6 is 12.

Claims (5)

1. a lens eccentricity setting device in the photoetching projection objective lens of decoupling zero, comprises picture frame, sensor (9) and driving mechanism (10); It is characterized in that, described picture frame comprises outer picture frame (2), interior picture frame (3), support seat (4), guiding hole (5), connecting thread hole (6), flexible guiding mechanism (7) and flexible linking device (8);

Described picture frame entirety is circular ring structure, described interior picture frame (3) bottom is fixed with and supports seat (4), described interior picture frame (3) and described outer picture frame (2) running fit, described interior picture frame (3) and outer picture frame (2) are connected by n group flexible linking device (8) of circumference uniform distribution, on circumferential direction, it is provided with one group of flexible guiding mechanism (7) between adjacent two flexible linking devices (8), described outer picture frame (2) and flexible guiding mechanism (7) opposite position are provided with radial guiding hole (5), two guiding hole (5) about center of circle symmetry are respectively arranged with a driving mechanism (10) and a sensor (9),

Described flexible guiding mechanism (7) comprises four to be had and has along the tangential flexible compound quadrangular mechanism of outer picture frame (2) along the parallel-crank mechanism of outer picture frame (2) radial compliance and two; Each parallel-crank mechanism connects two rigid link by two flexible leaf springs and forms; Each compound quadrangular mechanism connects 5 movable rigid link by 6 flexible leaf springs and forms.

2. lens eccentricity setting device in the photoetching projection objective lens of a kind of decoupling zero according to claim 1, it is characterised in that, described n group flexible linking device (8) specifically refers to 4 groups.

3. lens eccentricity setting device in the photoetching projection objective lens of a kind of decoupling zero according to claim 1, it is characterised in that, described flexible linking device (8) is two Z-shaped flexible leaf springs (801).

4. lens eccentricity setting device in the photoetching projection objective lens of a kind of decoupling zero according to claim 1, it is characterised in that, the uniform multiple connecting thread hole (6) of described outer picture frame (2) end face of flange.

5. lens eccentricity setting device in the photoetching projection objective lens of a kind of decoupling zero according to claim 4, it is characterised in that, the number of described connecting thread hole (6) is 12.