WO2022062959A1

WO2022062959A1 - Controllable lifting device with precision measurement capability and photolithography apparatus containing same

Info

Publication number: WO2022062959A1
Application number: PCT/CN2021/118176
Authority: WO
Inventors: 成荣; 朱煜; 张鸣; 杨开明; 刘相波
Original assignee: 清华大学
Priority date: 2020-09-28
Filing date: 2021-09-14
Publication date: 2022-03-31
Also published as: CN112051715A

Abstract

Disclosed are a controllable lifting device with precision measurement capability and a photolithography apparatus containing the same. The device comprises a fixing base, a guiding base, a moving assembly and a driving assembly. The fixing base has fixed connection to the guiding base. The fixing base is provided with a guiding bushing having a vertical axis. The moving assembly comprises a lifting head, a guiding rod and a magnetic steel. A mounting hole is arranged on the upper end of the guiding rod. The guiding rod passes through the guiding bushing and forms air-bearing contact surfaces with the guiding bushing, the fixing base and the guiding base. The magnetic steel and the lifting head are mounted in sequence into the mounting hole of the guiding rod such that the lifting head protrudes from the upper end of the guiding bushing. The driving assembly comprises a motor coil and an iron core. The iron core is arranged in the annular space between the guiding rod and the guiding bushing. The motor coil is wound onto the iron core. An air hole is provided at the center of the moving assembly. The fixing base provides a positive-pressure or negative-pressure gas to the air hole by means of an air passage of the guiding rod. According to the present disclosure, air-bearing contact surfaces are used to guide the direction. The friction between parts is reduced, particles are not generated, motion precision is improved, and the requirement of motor driving force is reduced.

Description

Controllable lift device with precision measurement and lithography apparatus containing the same

technical field

The invention relates to the technical field of lithography, in particular to a controllable lifting device with precise measurement and a lithography apparatus including the same.

Background technique

The silicon wafer handover device of the lithography equipment cooperates with the transfer manipulator to realize the handover function of the silicon wafer. The device used for controllable lifting and lowering of silicon wafers in lithography equipment is usually called E-pin. The E-pin is installed on the wafer stage, and the lithography equipment needs to perform loading and unloading operations on the silicon wafer during operation. When loading the wafer, the wafer is transferred to the set position by the robot, and the pin bar of the E-pin extends to remove the wafer from the robot, and then the pin bar retracts to place the wafer on the wafer stage. When the wafer is unloaded, the pin rod extends to lift the wafer from the wafer stage to the set height, and then is taken away by the robot. Therefore, E-pin not only needs a retractable function for lifting and lowering the silicon wafer, but also needs a function of position measurement to prevent the silicon wafer and components from being damaged due to improper lifting of the silicon wafer.

The inventor found that when the silicon wafer is taken and placed on the suction cup, particle pollution will be introduced by using the current sliding and rolling transmission structure. However, particle contamination will still be introduced; with rolling guide, roller guide is used between the guide rod and the guide sleeve or the fixed seat and the guide base, which will introduce grease, cause particle contamination, and destroy the lithography environment.

To this end, a structure that can be guided without polluting the lithography environment should be adopted, and so far, there is no better solution.

SUMMARY OF THE INVENTION

In order to solve the above problems, the present invention provides a controllable lifting device with precise measurement, including a fixed base, a guide seat, a moving component, and a driving component,

Among them, the fixed base is fixedly connected with the guide seat, and a guide sleeve with a vertical axis is installed on the fixed base,

Among them, the mobile components include:

lift head,

The guide rod has a mounting hole coaxial with the guide sleeve at the upper end, the guide rod passes through the guide sleeve coaxially, and the upper part of the guide rod and the guide sleeve, the lower part of the guide rod and the fixed base and the guide seat form an air-floating contact surface ;

The magnetic steel, the magnetic steel and the lifting head are sequentially installed into the installation holes of the guide rod, so that the lifting head extends out of the upper end of the guide sleeve,

Among them, the drive components include:

The motor coil and the iron core, the iron core is coaxially arranged in the annular space between the guide rod and the guide sleeve, the motor coil is wound on the iron core,

Wherein, an air hole penetrating to the upper end of the lifting head is coaxially opened in the center of the moving assembly, an air inlet hole and an air passage connecting the air inlet hole and the air hole are arranged on the guide rod, and an air hole is opened on the fixed base. Air source hole and air outlet hole, the air source hole is communicated with the air source, the air outlet hole is communicated with the air inlet hole on the guide rod through a hose, and the air source hole provides positive or negative pressure to the air hole gas.

Preferably, the moving assembly further includes a first rubber ring, a support rod, and a fixing sleeve, and the fixing sleeve, the support rod, the first rubber ring, and the lifting head are sequentially connected and installed into the installation holes of the guide rod.

Preferably, a cooling water groove for cooling the motor coil is opened on the fixed base, a cooling water fixing sleeve surrounds the periphery of the fixed base to seal the cooling water groove, and a cooling water groove is provided on the fixed base to communicate with the cooling water groove water inlet and outlet.

Preferably, the fixed base is provided with a grating scale reading head mounting hole penetrating the fixed base to the guide rod, the grating scale reading head is installed on the fixed base through the grating scale reading head mounting hole, and the guide rod There is a grating ruler on it.

Preferably, a vertical limit groove is provided on the guide rod, a limit rod installation hole is provided on the fixing base, and the limit rod passes through the limit rod installation hole and is fixed to the guide seat by screw connection The end of the limit rod passing through the guide seat is inserted into the limit groove, and the end of the limit rod passing through the guide seat is sleeved with a second rubber ring.

Preferably, the guide rod is provided with two air inlet holes and air passages respectively communicated with the air holes by the air inlet holes, and two air source holes are opened on the fixed base, one air source hole is connected to the positive pressure The air source is communicated, and the other air source hole is communicated with the negative pressure air source. The fixed base is also provided with two air outlet holes, and the two air outlet holes are respectively communicated with the corresponding air inlet holes on the guide rod through hoses.

Preferably, the upper and lower ends of the magnetic steel are respectively provided with iron core disks, and an adjustment pad is also provided between the iron core disk at the upper end and the fixing sleeve.

Preferably, the guide rod comprises a cylinder and a block coaxially connected under the cylinder, an air-floating contact surface is formed between the upper part of the cylinder and the guide sleeve, and the two opposite sides of the block are in contact with each other. One side is formed by protruding a plurality of first vertical planes parallel to each other and the guide seat to form an air-floating contact surface, and the other side of the two opposite sides of the square body is formed by two relatively inclined extending first. An air-floating contact surface is formed between the two vertical planes and the fixed base.

Preferably, at least three positioning support rods extend from the fixed base, and coplanar positioning planes are formed at the ends of all positioning support rods, and positioning pin holes are provided on the positioning planes.

The present invention also provides a lithography apparatus, which includes a wafer-bearing stage for carrying silicon wafers, and also includes the above-mentioned controllable lifting device with precise measurement, wherein the controllable lifting device is installed on the wafer-bearing stage.

The controllable lifting device with precise measurement of the present invention and the lithography apparatus comprising the same have the following technical effects:

(1) The use of air-floating contact surface guidance only retains the vertical degree of freedom of the guide rod, which can reduce the friction between the parts, avoid the generation of particles, improve the motion accuracy, and reduce the requirements of the motor driving force;

(2) Through the cooperation of the limit groove and the limit rod, it is possible to prevent the silicon wafer from exceeding the stroke range under special circumstances and damage the silicon wafer and other lithography equipment parts, such as fork manipulators, objective lenses, etc.;

(3) The first rubber ring prevents the silicon wafer from directly contacting the pin rigidly, prevents the silicon wafer from being damaged when it contacts the structural member with high rigidity, and can realize Rx, Ry, Z direction (the vertical direction is the Z axis) of Cartesian coordinates) minor adjustments to the degrees of freedom.

(4) The rise and fall of the silicon wafer can be monitored in real time, and the position of the silicon wafer can be precisely controlled.

(5) The up and down movement of the lifting head relies on electromagnetic interaction, which not only saves space, but also meets the needs of stable and reliable transmission of silicon wafers up and down.

Description of drawings

The above-described features and technical advantages of the present invention will become more clearly and easily understood by describing its embodiments in conjunction with the following drawings.

1 is a front sectional view showing a controllable lifting device with precise measurement according to an embodiment of the present invention;

FIG. 2 is a side cross-sectional view showing a controllable lifting device with precise measurement according to an embodiment of the present invention;

3 is a schematic structural diagram showing the connection between the lifting head, the first rubber ring and the support rod according to the embodiment of the present invention;

FIG. 4 is a schematic diagram showing pores and air passages according to an embodiment of the present invention;

5 is a perspective view showing a fixed base according to an embodiment of the present invention;

FIG. 6 is a perspective view showing a moving assembly according to an embodiment of the present invention;

FIG. 7 is a bottom view showing a controllable lift device with precise measurement according to an embodiment of the present invention.

The figure includes: lifting head 1, first rubber ring 2, support rod 3, fixing sleeve 4, E-pin guide rod 5, guide sleeve 6, adjusting pad 7, iron core plate 8, magnetic steel 9, cooling water fixing sleeve 10. Cooling water sealing ring 11, coil iron core 12, motor coil 13, fixed base 14, grating scale reading head 15, grating scale 16, guide seat 17, limit rod 18, limit rod second rubber ring 19, Flexible air pipe 20, air pipe joint 21, screw 22, limit slot 23, air hole 400, air intake hole 51, air passage 52, air outlet hole 141, screw hole 142, limit rod mounting hole 143, cylinder 55, block body 56 , a first vertical plane 300 , a second vertical plane 200 , a connecting vertical plane 561 , a positioning plane 147 , a positioning strut 146 , and a positioning pin hole 148 .

detailed description

Embodiments of the controllable lift device with precision measurement according to the present invention and a lithographic apparatus including the same will be described below with reference to the accompanying drawings. As those of ordinary skill in the art would realize, the described embodiments may be modified in various different ways or combinations thereof, all without departing from the spirit and scope of the present invention. Accordingly, the drawings and description are illustrative in nature and are not intended to limit the scope of protection of the claims. Furthermore, in this specification, the drawings are not drawn to scale, and the same reference numerals refer to the same parts.

As shown in FIG. 1, the controllable lifting device with precise measurement includes a fixed base 14, a guide base 17, a moving component, and a driving component, wherein the fixed base 14 is fixedly connected with the guide base 17, and FIG. 5 shows the fixed base A three-dimensional schematic diagram, wherein a screw hole 142 is processed on the fixing base 14 , and the guide base 17 is fixedly connected to the fixing base 14 through the screw hole 142 . A guide sleeve 6 with a vertical axis is mounted on the fixed base 14 . The moving assembly includes a lifting head 1, a guide rod 5, and a magnetic steel 9. The upper end of the guide rod 5 has a mounting hole coaxial with the guide sleeve 6. The guide rod 5 passes through the guide sleeve 6 coaxially and penetrates into the fixed position. In the space enclosed by the base 14 and the guide seat 17 . An annular space is formed between the guide sleeve 6 and the guide rod 5 . Moreover, air-floating contact is formed between the guide rod 5 and the guide sleeve 6, the fixed base 14, and the guide seat 17 to limit the freedom of the guide rod 5 in five directions and retain its vertical freedom. The air-floating contact means that there is a certain gap between the two contact surfaces, and there is air between the gaps, which makes the two contact surfaces have a certain guiding effect, and has the characteristics of small friction coefficient and smooth sliding. . Of course, the gap should not be too large, otherwise it will not play a guiding role.

The magnetic steel 9 and the lifting head 1 are sequentially inserted into the mounting holes of the guide rod 5, so that the lifting head 1 protrudes from the upper end of the guide sleeve 6. Preferably, the moving assembly also includes a first rubber ring 2, a support rod 3, and a fixed sleeve 4. , as shown in Figures 3 and 4, the lifting head 1 is connected with the first rubber ring 2, the first rubber ring 2 is connected with the support rod 3, the support rod 3 is connected with the fixing sleeve 4 below, and then the fixing sleeve 4 is installed in the mounting hole of the guide rod 5. The function of the first rubber ring 2 is to ensure that the lifting head 1 can have certain flexibility in the Rx, Ry and Z directions. In addition, the upper and lower ends of the magnetic steel 9 are provided with iron core disks 8 , and the function of the iron core disk 8 is to optimize the magnetic field of the magnetic steel 9 itself, so that the magnetic field lines in the magnetic steel 9 form a closed loop. An iron core disc 8 is inserted into the mounting hole, then the magnetic steel 9 is inserted, and then the iron core disc 8 is inserted. An adjustment pad 7 can also be arranged above the iron core disc 8, and the adjustment pad 7 is used to adjust the overall height. Then, install the fixing sleeve 4, the support rod 3, the first rubber ring 2, and the lifting head 1 into the installation holes in sequence.

The drive assembly includes a motor coil 13 and a coil iron core 12, and the guide sleeve 6 has an annular inner shoulder, so that an annular space with different gaps is formed between the guide rod 5 and the guide sleeve 6, and the upper annular space has a relatively larger gap. Small, the guide rod 5 and the guide sleeve are the air-floating contact surface, the lower annular space has a large gap, the coil iron core 12 is coaxially arranged in the lower annular space, and the motor coil 13 is wound on the coil iron core 12. The guide sleeve and the fixed base are provided with threading holes through which the two ends of the motor coil 13 are connected to the power supply.

Among them, as shown in FIG. 4 , an air hole 400 is coaxially opened in the center of the moving component, that is to say, the air hole 400 penetrates the lifting head 1, the first rubber ring 2, the support rod 3, the fixing sleeve 4, the adjustment pad 7, the iron The core disc 8 and the magnetic steel 9 enter the guide rod 5, and the air hole is closed at the lower end of the guide rod 5. As shown in FIG. An air inlet hole 51 and an air passage 52 connecting the air inlet hole 51 and the air hole 400 are provided on the guide rod 5 , and an air source hole is opened on the fixed base 14 , and the air source hole communicates with the air source , the fixed base is also provided with an air outlet 141, the air outlet 141 communicates with the air inlet 51 on the guide rod 5 through the flexible air pipe 20 and the air pipe joint 21, and provides positive pressure or pressure to the air hole 400 through the air source hole. Negative pressure gas.

Preferably, the guide rod 5 is provided with two air inlet holes and air passages respectively communicated with the air holes by the air inlet holes, and two air source holes are opened on the fixed base, and one air source hole is connected with the positive air hole. The pressure air source is connected, the other air source hole is connected with the negative pressure air source, and the fixed base is also provided with two air outlet holes, and the two air outlet holes are respectively connected with the air inlet holes on the guide rod 5 through the hose. The air source holes can be processed at the bottom of the fixed base 14, respectively, to realize the functions of vacuum extraction and back blowing of the silicon wafer.

Further, the fixing base 14 is provided with a cooling water groove for cooling the motor coil, and the cooling water fixing sleeve 10 seals the cooling water groove around the periphery of the fixing base. As shown in FIG. 2 , the cooling water fixing sleeve 10 is connected to the fixing base 14 by screws 22 , and the fixing base 14 is provided with a water inlet and a water outlet communicating with the cooling water tank. The cooling water fixing sleeve 10 is connected to the fixing base 14 Cooling water sealing rings 11 are installed on the upper and lower sides of the room to seal the cooling water.

Further, a grating ruler reading head mounting hole is provided on the fixed base 14, and the grating ruler reading head 15 is installed on the fixed base 14 through the grating ruler reading head mounting hole, on the outer circumference of the guide rod 5. A vertical grating ruler is provided, and the grating ruler reading head 15 can read the reading of the grating ruler 16 during the upward and downward movement of the guide rod 5 .

Further, the guide rod 5 is provided with a vertical limit groove 23 , the fixed base 14 is provided with a limit rod installation hole 143 , and the limit rod 18 passes through the limit rod installation hole 143 and passes through The threaded connection is fixed on the guide seat 17, the end of the limit rod 18 passing through the guide seat 17 is inserted into the limit groove 23, and the end of the limit rod 18 passing through the guide seat 17 is sleeved with a limit rod The second rubber ring 19 avoids the direct rigid contact between the limit rod 18 and the limit groove 23 of the guide rod, and at the same time acts as a limiter for the guide rod.

Further, as shown in FIG. 6 , the guide rod 5 includes a cylinder 55 and a block 56 coaxially connected to the bottom of the cylinder, and an air-floating contact surface is formed between the upper part of the cylinder 55 and the guide sleeve 6, One of the opposite sides of the block body 56 is formed by protruding a plurality of mutually parallel first vertical planes 300 and the guide seat 17 to form an air-floating contact surface. In FIG. 6 , two first vertical planes are used. towards plane 300. Of course, this embodiment does not limit the number of the first vertical planes 300 , and may also be one. The other side of the two opposite sides of the block body 56 forms an air-floating contact surface between the two second vertical planes 200 extending relatively obliquely and the fixed base. The two second vertical planes 200 may also be vertical cut planes with different inclination angles. The air-floating contact surface between the cylinder 55 and the guide sleeve can be only a part of the outer diameter of the cylinder and the guide sleeve for air-floating contact, while the outer diameter of other parts can be relatively reduced to make the sliding smooth. . For example, in FIG. 6 , the outer diameter of the annular boss 100 is larger than the outer diameter of the cylinder 55 , and the annular boss 100 and the guide sleeve 6 are in air-floating contact.

The second vertical plane 200 may be two symmetrical vertical planes that are vertically cut from the horizontal ends of the side at a certain inclination angle, as shown in FIG. In the cut vertical plane, a concave connecting vertical plane 561 is formed between the two second vertical planes 200. The grating ruler 16 is installed on the connecting vertical plane 561, which can protect the grating scale from collision during the up and down movement. damage. This embodiment is not used to limit the number of the floating contact surfaces.

Further, at least three positioning struts 146 extend from the fixed base 14 , the ends of all the positioning struts 146 are formed with coplanar positioning planes 147 , and positioning pin holes 148 are provided on the positioning planes 147 . Through the positioning plane 147, the fixing base 14 is mounted on the reference plane.

The working process of the controllable lifting device with precise measurement is described below:

Before working, the assembled controllable lifting device is fixed on the reference plane through the positioning surface 147 on the fixed base 14 , and its position is fixed by the positioning pin through the positioning pin hole 148 processed on the fixed base 14 .

When working, when the silicon wafer needs to be removed from the fork manipulator, in order to prevent the silicon wafer from slipping off, the lifting head 1 provides back vacuum suction, so that the silicon wafer is adsorbed on the lifting head 1. When the silicon wafer is adsorbed on the lifting head 1 When the motor coil 13 is controlled, the motor coil 13 interacts with the magnetic force of the magnetic steel 9, so that the part of the guide rod 5 with the lifting head 1 moves down as a whole. Real-time monitoring of the falling height of the silicon wafer, when reaching the designated position, turn off the air source that provides the vacuum environment, and provide back blowing gas to the lifting head 1 to make the silicon wafer detach from the lifting head 1, and the detached silicon wafer will fall on the suction cup at this time. , and perform subsequent operations.

When the processed silicon wafer needs to be released from the suction cup, the air hole in the lift head 1 provides back vacuum suction again, and the silicon wafer is adsorbed on the lift head, and then through the interaction between the motor coil 13 and the magnetic steel 9, the lift 1 drives the silicon wafer The wafer moves upwards and reaches the designated position. When the wafer manipulator needs to remove the wafer, the back vacuum suction is stopped, and the wafer can be removed.

During the whole moving process, the device provides air-floating guide structure, cooling water cooling structure, limit structure and real-time position detection to ensure the smooth and safe process of the silicon wafer from the fork manipulator to the suction cup or from the suction cup to the fork manipulator. operation.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

A controllable lifting device with precise measurement is characterized in that it includes a fixed base, a guide seat, a moving component, and a driving component,

Among them, the fixed base is fixedly connected with the guide seat, and a guide sleeve with a vertical axis is installed on the fixed base,

Among them, the mobile components include:

lift head,

The guide rod has a mounting hole coaxial with the guide sleeve at the upper end, the guide rod passes through the guide sleeve coaxially, and the upper part of the guide rod and the guide sleeve, the lower part of the guide rod and the fixed base and the guide seat form an air-floating contact surface ;

The magnetic steel, the magnetic steel and the lifting head are sequentially installed into the installation holes of the guide rod, so that the lifting head extends out of the upper end of the guide sleeve,

Among them, the drive components include:

The motor coil and the iron core, the iron core is coaxially arranged in the annular space between the guide rod and the guide sleeve, the motor coil is wound on the iron core,

Wherein, an air hole penetrating to the upper end of the lifting head is coaxially opened in the center of the moving assembly, an air inlet hole and an air passage connecting the air inlet hole and the air hole are arranged on the guide rod, and an air hole is opened on the fixed base. Air source hole and air outlet hole, the air source hole is communicated with the air source, the air outlet hole is communicated with the air inlet hole on the guide rod through a hose, and the air source hole provides positive or negative pressure to the air hole gas.
The controllable lifting device with precise measurement according to claim 1, wherein the moving component further comprises a first rubber ring, a support rod and a fixed sleeve, the fixed sleeve, the support rod, the first rubber ring, and the lifting head Connect them into the mounting holes of the guide rod in sequence.
The controllable lifting device with precise measurement according to claim 1, wherein a cooling water tank for cooling the motor coil is opened on the fixed base, and the cooling water fixing sleeve surrounds the outer sealing area of the fixed base. In the cooling water tank, a water inlet and a water outlet communicated with the cooling water tank are arranged on the fixed base.
A controllable lifting device with precise measurement according to claim 1, wherein the fixed base is provided with a grating reading head mounting hole penetrating the fixed base to the guide rod, and the grating reading head passes through the The grating ruler reading head mounting hole is installed on the fixed base, and the grating ruler is arranged on the guide rod.
The controllable lifting device with precise measurement according to claim 1, wherein a vertical limit groove is provided on the guide rod, and a limit rod mounting hole is provided on the fixed base to limit the limit rod. The limit rod passes through the limit rod installation hole and is fixed on the guide seat by threaded connection, the end of the limit rod passing out of the guide seat is inserted into the limit slot, and the limit rod passes out of the guide seat. The end is sleeved with a second rubber ring.
A controllable lifting device with precise measurement according to claim 1, characterized in that, two air inlet holes and air passages respectively communicated with the air holes are provided on the guide rod, There are two air source holes on the fixed base, one air source hole is connected with the positive pressure air source, the other air source hole is connected with the negative pressure air source, and the fixed base is also provided with two air outlet holes, two outlet holes. The air holes are respectively communicated with the corresponding air inlet holes on the guide rod through hoses.
The controllable lifting device with precise measurement according to claim 2, wherein the upper and lower ends of the magnetic steel are respectively provided with iron core disks, and between the iron core disk at the upper end and the fixed sleeve Adjustment pads are also provided.
The controllable lifting device with precise measurement according to claim 1, wherein the guide rod comprises a cylinder and a block coaxially connected below the cylinder, the upper part of the cylinder and the guide sleeve An air-floating contact surface is formed between them, and one of the two opposite sides of the block body is formed by protruding a plurality of first vertical planes that are parallel to each other and the guide seat to form an air-floating contact surface. The other side of the two opposite sides is formed by two relatively inclined second vertical planes and the fixed base to form an air-floating contact surface.
The controllable lifting device with precise measurement according to claim 1, wherein at least three positioning struts extend from the fixed base, and the ends of all the positioning struts are formed with coplanar positioning planes, And the positioning pin holes are arranged on the positioning plane.
A lithography apparatus, comprising a wafer-bearing stage for carrying silicon wafers, characterized in that it further comprises a controllable lifting device with precise measurement according to any one of claims 1 to 9, the controllable lifting device is installed on the stage.