Infrared double-sided overlay independent automatic measured object focal length and transmission light focal length adjusting structure

Abstract

The invention provides an infrared double-sided overlay independent automatic measured object focal length and transmission light focal length adjusting structure, which comprises an objective table which is used for bearing a wafer, is of a hollow structure and is connected with the output end of an objective table focusing unit; the objective table focusing unit can move along the base in the Z direction; the imaging light path unit is arranged above the objective table; the transmission light source is arranged below the hollow area of the objective table and is connected with the output end of the transmission light focusing unit; the transmission light focusing unit can move along the bottom plate in the Z direction, and the bottom plate is connected with the base. According to the invention, the distance of a measured object and the focal length of transmission light can be independently adjusted.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of double-sided lithography, and particularly relates to an independent automatic focal length adjustment structure for a measured object and a transmission light source in infrared double-sided lithography. BACKGROUND

[0002] In the working process of a double-sided lithography machine, there is a problem of deviation of printing position (or other wafers or similar products with upper and lower alignment marks), but how to accurately inform the lithography machine (or similar upper and lower alignment process equipment) of the deviation value is difficult, which requires that the related measurement equipment has high precision and high stability, and overcomes the problem of different focal lengths of the upper and lower layers with very thick thickness. SUMMARY

[0003] The application aims to provide an independent automatic focal length adjustment structure for a measured object and a transmission light source in infrared double-sided lithography, which can independently adjust the focal length of the measured object and the transmission light. The technical scheme adopted is as follows: An independent automatic focal length adjustment structure for a measured object and a transmission light source in infrared double-sided lithography comprises: A wafer table 1 for carrying a wafer, which is a hollow structure and is connected with the output end of a wafer table focusing unit 5; The wafer table focusing unit 5 can move along the base 4 and in the Z direction; An imaging light path unit 2 is arranged above the wafer table 1; A transmission light source 3 is arranged below the hollow area of the wafer table 1 and is connected with the output end of a transmission light focusing unit 6; The transmission light focusing unit 6 can move along the bottom plate 7 and in the Z direction, and the bottom plate 7 is connected with the base 4.

[0004] Preferably, the base 4 comprises: A first plate 40 and a second plate 41 connected with the first plate 40; the second plate 41 extends upward in the Z direction from the first plate 40; The bottom plate 7 comprises a first plate 70 and a second plate 71 connected with the first plate 70; the second plate 71 extends upward in the Z direction from the first plate 70; The wafer table focusing unit 5 forms a first Z-direction sliding pair with the front surface of the second plate 41; The transmission light focusing unit 6 is located in the area surrounded by the wafer table focusing unit 5 and forms a second Z-direction sliding pair with the second plate 71.

[0005] Preferably, the first Z-direction sliding pair comprises: A guide rail and a sliding block matched with the guide rail; The guide rail is arranged on the second plate 41, and the sliding block is arranged on the wafer table focusing unit 5.

[0006] Preferably, the second Z-direction sliding pair comprises: a first sliding rail, which is arranged on the first plate 70 and has a dovetail groove formed on the outer surface thereof in the X-direction; a second sliding rail, which is arranged on the transmitted light focusing unit 6 and cooperates with the dovetail groove;

[0007] Preferably, the stage focusing unit 5 comprises: a first mounting base 50, which is arranged on the first plate 40 and located behind the second plate 71, and has a front end sequentially penetrating through the second plate 41 and the first sliding plate 55 in the front direction; a first motor 51, the housing of which is arranged on the first mounting base 50, and the output shaft of which is connected with the first ball screw; the first ball screw, which is rotatably arranged on the first mounting base 50, and has a first nut 52 connected with a first connecting frame 53; the first connecting frame 53, which has two free ends distributed in the X-direction, and the second plate 41 and the first sliding plate 55 are both provided with windows for the first connecting frame 53 to penetrate through; a first wedge unit 54, the inner surface of the lower wedge block of which is connected with one free end of the first connecting frame 53, and the rear end surface of the upper wedge block of which is connected with the front surface of the same first sliding plate 55, and the lower wedge block and the first plate 40 form a first Y-direction sliding pair; the first sliding plate 55 and the second plate 41 form the first Z-direction sliding pair; the upper wedge block and the lower wedge block of the first wedge unit 54 form an inclined sliding pair.

[0008] Preferably, the first Y-direction sliding pair and the inclined sliding pair have the same structure as the first Z-direction sliding pair.

[0009] Preferably, the transmitted light focusing unit 6 comprises: a second mounting base 60, which is arranged on the first plate 70 and located in front of the second plate 71; a second motor 61, the housing of which is arranged on the second mounting base 60, and the output shaft of which is connected with a second ball screw; the second ball screw, which is rotatably arranged on the second mounting base 60, and has a second nut 62 connected with a second connecting frame 63; a pair of second wedge units 64, the lower wedge block of each of which is connected with the same lower sliding plate 67, and the lower sliding plate 67 and the first plate 70 form a first Y-direction sliding pair, and the outer surface of the lower wedge block of one of the second wedge units 64 is connected with the second connecting frame 63; the rear end surface of the upper wedge block of each of the pair of second wedge units 64 is connected with the front surface of the same second sliding plate 65; and the upper wedge block and the lower wedge block of the second wedge unit 64 form an inclined sliding pair; The second Z-direction sliding pair is formed between the second sliding plate 65 and the second plate 71; The mounting plate 66 is connected with the upper wedge-shaped block of the pair of second wedge-shaped units 64 and is located above the lower sliding plate 67, and the transmission light source 3 is arranged on the mounting plate 66.

[0010] Preferably, the object table 1 comprises: The base 10 is connected with the output end of the object table focusing unit 5; The fixed rail 11, the lower guide rail 12 and the upper guide rail 13 are sequentially and slidably connected from bottom to top, and the fixed rail 11 is fixedly connected with the base 10; The lower guide rail 12 is connected with the output end of the Y-direction module through the Y-direction connecting piece 8; The upper guide rail 13 is connected with the output end of the X-direction module through the X-direction connecting piece 9; The Y-direction module and the X-direction module are arranged on the base 10.

[0011] Preferably, the lower guide rail 12 and the upper guide rail 13 are slidably connected through the inner sliding rail 14 and the outer sliding rail 15; The inner sliding rail 14 is arranged on the lower guide rail 12, and the outer sliding rail 15 is arranged on the upper guide rail 13 Compared with the prior art, the object table of the present application has the following advantages: The up-and-down structure of the object table can ensure that the wafer is on the imaging focal plane required by the camera, and the transmission light source can be automatically adjusted up and down without affecting the independent movement of the object table. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figures 1-2 It is an equipment diagram of an independent automatic object focal length and transmission light focal length adjusting structure provided with infrared double-face overlaying; Figures 3-4 It is a perspective view of an independent automatic object focal length and transmission light focal length adjusting structure of infrared double-face overlaying; Figure 5 It is a schematic view of relative positions of an object table, a transmission light source, an object table focusing unit and a transmission light focusing unit; Figure 6 It is a schematic view of relative positions of a base plate, an object table and a base; Figure 7 It is a connection mode display diagram of a first connecting frame and a first nut; Figure 8 It is a structural diagram of an object table focusing unit; Figure 9 It is a schematic view of relative positions between a first mounting seat in an object table focusing unit and other components; Figure 10The relative position between the No. 1 wedge unit in the objective table focusing unit and the transmission light focusing unit is shown in the figure; Figure 11 The mounting mode of the mounting plate in the transmission light focusing unit is shown in the figure; Figure 12 The relative position between the mounting plate in the transmission light focusing unit and the lower slide plate is shown in the figure; Figure 13 The structure of the transmission light focusing unit is shown in the figure; Figure 14 The structure of the No. 2 Z-direction sliding pair is shown in the figure; Figures 15-16 The perspective view of the objective table is shown in the figure; Figure 17 The exploded view of the objective table is shown in the figure.

[0013] Among them, 1-Objective table, 10-Base, 11-Fixed rail, 12-Lower guide rail, 13-Upper guide rail, 14-Internal slide rail, 15-External slide rail; 2-Optical path unit, 3-Transmission light source, 4-Base, 40-Plate 1, 42-Plate 2; 5-Objective table focusing unit, 50-No. 1 mounting seat, 51-No. 1 motor, 52-No. 1 nut, 53-No. 1 connecting frame, 54-No. 1 wedge unit, 55-No. 1 slide plate; 6-Transmission light focusing unit, 60-No. 2 mounting seat, 61-No. 2 motor, 62-No. 2 nut, 63-No. 2 connecting frame, 64-No. 2 wedge unit, 65-No. 2 slide plate, 66-Mounting plate, 67-Lower slide plate; 7-Bottom plate, 70-No. 1 plate, 71-No. 2 plate; 8-Y-direction connecting piece, 9-X-direction connecting piece. DETAILED DESCRIPTION

[0014] The independent automatic object focal length and transmission light focal length adjusting structure for infrared double-sided overlay will be described in more detail below with reference to the accompanying drawings, in which the preferred embodiments of the present application are shown, and it should be understood that those skilled in the art can modify the present application described herein while still achieving the advantageous effects of the present application. Therefore, the following description should be understood as a broad knowledge for those skilled in the art, and not as a limitation of the present application.

[0015] As Figures 1-17 An independent automatic object focal length and transmission light focal length adjusting structure for infrared double-sided overlay, comprising: An objective table 1 for carrying a wafer, which is a hollow structure connected with the output end of an objective table focusing unit 5; the wafer covers the hollow area.

[0016] A stage focusing unit 5, which is movable along the base 4 and in the Z direction; An imaging light path unit 2 (prior art), which is arranged above the stage 1, and which comprises a microscope camera, an epi-illumination light path with an epi-illumination entrance, and an imaging lens. Specifically, the imaging light path unit 2 is fixedly installed on the gantry beam.

[0017] And a transmitted light source 3, which is arranged below the hollow region of the stage 1, and which is connected to the output end of the transmitted light focusing unit 6; The transmitted light focusing unit 6, which is movable along the bottom plate 7 and in the Z direction, and the bottom plate 7 is connected to the base 4 by fasteners.

[0018] The measured object distance can be understood as: this distance has a certain distance according to the objective lens configuration, and the distance will blur the image; The transmitted light focal length can be understood as: the light path configuration has a certain distance from the light source gathering point, and if the distance is offset, it will cause the dispersion of light and poor illumination effect.

[0019] In this embodiment, the output end of the stage focusing unit 5 is a first sliding plate 55; the output end of the transmitted light focusing unit 6 is a mounting plate 66.

[0020] The "front" direction refers to the Y direction and the direction towards the second plate 71.

[0021] The "out" direction refers to the X direction and the direction away from the second plate 71.

[0022] As shown in Figures 9-10 The base 4 comprises: A first plate 40, and a second plate 41 connected to the first plate 40; the second plate 41 extends upward from the first plate 40 in the Z direction; The bottom plate 7 comprises: a first plate 70, and a second plate 71 connected to the first plate 70; the second plate 71 extends upward from the first plate 70 in the Z direction; The stage focusing unit 5 forms a first Z-direction sliding pair between the front surface of the second plate 41; The transmitted light focusing unit 6 is located in the area surrounded by the stage focusing unit 5, and forms a second Z-direction sliding pair between the second plate 71.

[0023] As shown in Figure 10 The first Z-direction sliding pair comprises: A guide rail, and a sliding block matched with the guide rail; The guide rail is installed on the second plate 41 by fasteners, and the sliding block is installed on the stage focusing unit 5 by fasteners.

[0024] As shown in Figure 11 , Figure 14 The second Z-direction sliding pair comprises: The slide rail one is arranged on the first plate 70 through fastener installation and is provided with a dovetail groove on the outer surface along the X direction; The slide rail two is matched with the dovetail groove and is arranged on the transmission light focusing unit 6 through fastener installation.

[0025] As shown in Figure 8 , Figure 10 , the object table focusing unit 5 comprises: The first mounting seat 50 is arranged on the first plate 40 through fastener installation and is located behind the second plate 71, and the front end sequentially penetrates the second plate 41 and the first slide plate 55 forward; The first motor 51 is arranged on the first mounting seat 50, and the output shaft is connected with the first ball screw through the shaft coupling; The first ball screw is rotatably arranged on the first mounting seat 50 through the bearing, and the first nut 52 is connected with the first connecting frame 53; in the embodiment, the first connecting frame 53 is embedded in the first nut 52, as shown in Figure 8 .

[0026] The first connecting frame 53 comprises two free ends distributed along the X direction, and the second plate 41 and the first slide plate 55 are both provided with windows for the first connecting frame 53 to penetrate; The first wedge unit 54 is connected with one free end of the first connecting frame 53 through the inner surface of the lower wedge block, and the rear end surface of the upper wedge block is connected with the front surface of the same first slide plate 55, and the lower wedge block and the first plate 40 form a first Y direction sliding pair; in the embodiment, the first wedge unit 54 is connected with the first slide plate 55 through fastener.

[0027] The first slide plate 55 is slidingly connected with the second plate 41; The first wedge unit 54 forms an inclined sliding pair between the upper wedge block and the lower wedge block.

[0028] As shown in Figure 10 , the first Y direction sliding pair, the inclined sliding pair and the first Z direction sliding pair have the same structure.

[0029] The first Y direction sliding pair is arranged on the first plate 40 through fastener installation, and the sliding block is arranged on the first wedge unit 54 through fastener installation, as shown in Figure 10 .

[0030] The inclined sliding pair is arranged on the upper wedge block of the first wedge unit 54 through fastener installation, and the sliding block is arranged on the lower wedge block of the first wedge unit 54 through fastener installation, as shown in Figure 13 .

[0031] As shown in Figures 12-13 , the transmission light focusing unit 6 comprises: The second mounting seat 60 is mounted on the first plate 70 by fasteners and is located in front of the second plate 71; The second motor 61 has a housing mounted on the second mounting base 60 via fasteners, and its output shaft is connected to the second ball screw; The second ball screw is rotatably mounted on the second mounting seat 60 through a bearing, and its second nut 62 is connected to the second connecting frame 63; in this embodiment, the second connecting frame 63 is embedded in the second nut 62, as shown in FIG. Figure 13 shown.

[0032] A pair of No. 2 wedge-shaped units 64, whose lower wedge blocks are connected to the same lower slide plate 67, form a No. 1 Y-direction sliding pair between the lower slide plate 67 and the No. 1 plate 70, and the outer surface of the lower wedge block of one No. 2 wedge-shaped unit 64 is connected to the No. 2 connecting frame 63; in this embodiment, the lower slide plate 67 is connected to the upper wedge block of the No. 2 wedge-shaped unit 64 by a connecting piece and a fastener, as shown in FIG. Figure 13 shown.

[0033] The rear end surfaces of the upper wedge blocks of the pair of No. 2 wedge units 64 are both connected to the front surface of the same No. 2 slide plate 65; an inclined sliding pair is formed between the upper wedge block and the lower wedge block of the No. 2 wedge unit 64; The second slide plate 65 is slidably connected to the second plate 71; And the mounting plate 66 is connected to the upper wedge blocks of a pair of No. 2 wedge units 64 and is located above the lower slide plate 67, on which the transmission light source 3 is provided.

[0034] like Figures 15-17 As shown, the stage 1 includes: The base 10 is connected to the first slide 55 by fasteners; The fixed rail 11, the lower guide rail 12 and the upper guide rail 13 are slidably connected in sequence from bottom to top, and the fixed rail 11 is fixedly connected to the base 10 by fasteners; The lower guide rail 12 is connected to the output end of the Y-direction module through the Y-direction connector 8; the upper guide rail 13 is connected to the output end of the X-direction module through the X-direction connector 9; The Y-axis module and the X-axis module are both disposed on the base 10 .

[0035] like Figure 17 As shown, the lower guide rail 12 and the upper guide rail 13 are slidably connected via the inner slide rail 14 and the outer slide rail 15; The inner slide rail 14 is disposed on the lower guide rail 12 , and the outer slide rail 15 is disposed on the upper guide rail 13 .

[0036] Similarly, the lower guide rail 12 and the fixed rail 11 are also slidably connected via the inner slide rail and the outer slide rail.

[0037] In the embodiment, the Y direction module and the X direction module have the same structure, and comprise a motor and a ball screw connected with the motor.

[0038] The locking member (red component) Figure 4 is only used for installation and use when shipping is fixed, and is not shown in the embodiment. Figure 15

[0039] The working principle of the independent automatic object focal length and transmission focal length adjusting structure of the infrared double-side overlaying system is as follows: The wafer is carried by the object table 1, and the imaging light path unit 2 (camera and objective lens switching mechanism) is used for photographing and imaging.The objective lens switching mechanism can switch different magnification objective lenses to realize different measurement accuracy requirements. The upper and lower structures of the object table 1 can ensure that the wafer is on the imaging focal plane required by the camera. The light source adopts lower transmission illumination. Because the camera needs to photograph the product pattern MARK on the upper and lower surfaces of the wafer, the product will have different thickness changes, and the focal plane of the projection light source needs to be able to meet different focal plane changes. Therefore, the transmission light is designed to be automatically adjusted up and down, and does not affect the independent movement of the object table 1.

[0040] The wafer has been patterned by a mask, and there are mask (MASK) patterned marks on the wafer. The coordinate positions of the upper and lower marks are detected to tell whether the lithography machine is engraved. The measurement system is used to detect the engraving offset distance of the upper and lower layers of the lithography machine, and is not used for engraving.

[0041] The above is only a preferred embodiment of the present application, and does not limit the present application in any way. Any person skilled in the art can make any form of equivalent replacement, modification or change to the technical solutions and technical contents disclosed in the present application without departing from the scope of the technical solutions of the present application, and such changes still belong to the protection scope of the present application.

Claims

1. An independent automatic measurement object focus and transmitted light focus adjustment structure for infrared double-sided overlay, characterized in that: include: A stage (1) for carrying a wafer, which is a hollow structure and is connected to an output end of a stage focusing unit (5); The stage focusing unit (5) is movable along the base (4) and in the Z direction; An imaging optical path unit (2), which is arranged above the stage (1); and a transmitted light source (3), which is arranged below the hollow area of ​​the stage (1) and is connected to the output end of the transmitted light focusing unit (6); The transmitted light focusing unit (6) is movable along a bottom plate (7) and in the Z direction, and the bottom plate (7) is connected to the base (4).

2. The independent automatic measurement object focal length and transmitted light focal length adjustment structure for infrared double-sided overlay according to claim 1, characterized in that: The base (4) comprises: Plate 1 (40), plate 2 (41) connected to plate 1 (40); plate 2 (41) extending upward from plate 1 (40) along the Z direction; The bottom plate (7) comprises: a first plate (70), and a second plate (71) connected to the first plate (70); the second plate (71) extends upward from the first plate (70) along the Z direction; The stage focusing unit (5) forms a first Z-direction sliding pair with the front surface of the second plate (41); The transmitted light focusing unit (6) is located in the area surrounded by the stage focusing unit (5), and forms a second Z-direction sliding pair with the second plate (71).

3. The independent automatic object focus and transmitted light focus adjustment structure for infrared double-sided overlay according to claim 2, characterized in that: The first Z-direction sliding pair comprises: Guide rails and sliders matching the guide rails; The guide rail is arranged on the second plate (41), and the slider is arranged on the stage focusing unit (5).

4. The independent automatic object focus and transmitted light focus adjustment structure for infrared double-sided overlay according to claim 2, characterized in that: The second Z-direction sliding pair comprises: Slide rail 1, which is arranged on plate 1 (70) and has a dovetail groove on its outer surface along the X direction; The second slide rail cooperates with the dovetail groove and is arranged on the transmitted light focusing unit (6).

5. The independent automatic measurement object focal length and transmitted light focal length adjustment structure for infrared double-sided overlay according to claim 2, characterized in that: The stage focusing unit (5) comprises: A No. 1 mounting seat (50), which is arranged on the plate 1 (40) and is located behind the No. 2 plate (71), and its front end passes forward through the plate 2 (41) and the No. 1 slide plate (55) in sequence; A No. 1 motor (51), whose housing is disposed on a No. 1 mounting seat (50), and whose output shaft is connected to a No. 1 ball screw; The No. 1 ball screw is rotatably mounted on the No. 1 mounting seat (50), and the No. 1 nut (52) thereof is connected to the No. 1 connecting frame (53); The No. 1 connecting frame (53) includes two free ends distributed along the X direction, and the No. 2 plate (41) and the No. 1 slide plate (55) are both provided with windows for the No. 1 connecting frame (53) to pass through; and a wedge-shaped unit (54), wherein the inner surface of the lower wedge-shaped block is connected to a free end of the No. 1 connecting frame (53), the rear end surface of the upper wedge-shaped block is connected to the front surface of the same No. 1 slide plate (55), and a No. 1 Y-direction sliding pair is formed between the lower wedge-shaped block and the plate (40); The first Z-direction sliding pair is formed between the first slide plate (55) and the second plate (41); An inclined sliding pair is formed between the upper wedge block and the lower wedge block of the first wedge unit (54).

6. The independent automatic measurement object focal length and transmitted light focal length adjustment structure for infrared double-sided overlay according to claim 5, characterized in that: The structure of the No. 1 Y-direction sliding pair and the inclined sliding pair is the same as that of the No. 1 Z-direction sliding pair.

7. The independent automatic measurement object focal length and transmitted light focal length adjustment structure for infrared double-sided overlay according to claim 2, characterized in that: The transmitted light focusing unit (6) comprises: A second mounting seat (60) is provided on the first plate (70) and is located in front of the second plate (71); A second motor (61), whose housing is disposed on a second mounting seat (60), and whose output shaft is connected to a second ball screw; The second ball screw is rotatably mounted on the second mounting seat (60), and its second nut (62) is connected to the second connecting frame (63); A pair of No. 2 wedge-shaped units (64), the lower wedge-shaped blocks of which are both connected to the same lower slide plate (67), wherein a No. 1 Y-direction sliding pair is formed between the lower slide plate (67) and the No. 1 plate (70), wherein the outer surface of the lower wedge-shaped block of one No. 2 wedge-shaped unit (64) is connected to the No. 2 connecting frame (63); A pair of upper wedge blocks of the second wedge unit (64) have rear end surfaces connected to the front surface of the same second slide plate (65); an inclined sliding pair is formed between the upper wedge block and the lower wedge block of the second wedge unit (64); The second Z-direction sliding pair is formed between the second slide plate (65) and the second plate (71); and a mounting plate (66) connected to the upper wedge blocks of a pair of No. 2 wedge units (64) and located above the lower slide plate (67), on which the transmission light source (3) is provided.

8. The independent automatic measurement object focal length and transmitted light focal length adjustment structure for infrared double-sided overlay according to claim 1, characterized in that: The loading platform (1) comprises: A base (10) is connected to an output end of the stage focusing unit (5); The fixed rail (11), the lower guide rail (12) and the upper guide rail (13) are slidably connected in sequence from bottom to top, and the fixed rail (11) is fixedly connected to the base (10); The lower guide rail (12) is connected to the output end of the Y-direction module via a Y-direction connector (8); The upper guide rail (13) is connected to the output end of the X-direction module via an X-direction connecting member (9); The Y-direction module and the X-direction module are both arranged on a base (10).

9. The independent automatic measurement object focal length and transmitted light focal length adjustment structure for infrared double-sided overlay according to claim 8, characterized in that: The lower guide rail (12) and the upper guide rail (13) are slidably connected via an inner slide rail (14) and an outer slide rail (15); The inner slide rail (14) is arranged on the lower guide rail (12), and the outer slide rail (15) is arranged on the upper guide rail (13).

Images