CN101334591A - Leveling and focusing mechanism with large stroke adjustment function - Google Patents

Abstract

A leveling and focusing mechanism with a large stroke adjustment function, including a small stroke leveling and focusing mechanism and a large stroke adjusting mechanism arranged at the lower part of the small stroke leveling and focusing mechanism, the large stroke in the Z direction is controlled by an independent wedge block mechanism Realize, the micro-adjustment in Z direction is driven by the wedge block mechanism and realized by the reed guide. A leveling and focusing mechanism with a large stroke adjustment function provided by the present invention can realize Z-direction large-stroke adjustment and Z-direction micro-adjustment, improve dynamic performance and adjustment accuracy, and adapt to different application occasions and different thicknesses of silicon wafers Specification.

Description

Leveling and focusing mechanism with large stroke adjustment function

technical field

The invention relates to a leveling and focusing mechanism with a large stroke adjustment function, in particular to a silicon wafer stage leveling and focusing mechanism with a large stroke adjustment function.

Background technique

Focusing and leveling of the whole field is generally carried out by measuring the defocus amount at 3 or more different positions on the surface of the silicon wafer to calculate and correct the defocus amount and tilt of the entire silicon wafer surface. The essence is to adjust in the coordinate system θx, θy and Z-axis three degrees of freedom (where θx is the rotation around the X-axis, θy is the rotation around the Y-axis), to achieve the purpose of focusing and leveling the silicon wafer.

Patent US005204712A discloses a micro-motion table with 3 degrees of freedom. The basic principle of the table is that it is distributed on three points through three sets of cam mechanisms, and the three driving points are connected to the film support table through a flexible mechanism, and are guided by reeds to drive the film support table together to achieve leveling and adjustment. focus function. The 3 degrees of freedom adjustment of this table is not large, especially the Z-direction degree of freedom cannot realize large stroke adjustment.

Chinese patent CN2580470 discloses a three-degree-of-freedom ultra-precise positioning platform. Three groups of independent piezoelectric ceramic preloading mechanisms are fixed inside the table body in the form of an equilateral triangle. The table has a compact structure and high precision, but the adjustment range is small, and the piezoelectric ceramics are easy to generate heat, and it is not easy to carry out constant temperature control.

Contents of the invention

A leveling and focusing mechanism with a large stroke adjustment function provided by the present invention can realize Z-direction large-stroke adjustment and Z-direction micro-adjustment, improve dynamic performance and adjustment accuracy, and adapt to different application occasions and different thicknesses of silicon wafers Specification.

In order to achieve the above purpose, the present invention provides a leveling and focusing mechanism with a large stroke adjustment function, including:

A small-stroke leveling and focusing mechanism and a large-stroke adjusting mechanism arranged at the lower part of the small-stroke leveling and focusing mechanism;

The small-stroke leveling and focusing mechanism includes:

Leveling the focusing bottom plate;

A reed centrally arranged on the leveling and focusing base plate, the reed has several free ends;

upper plate;

Several small-stroke wedge-shaped mechanisms connecting the free ends of the reeds and the upper plate;

Several small-stroke drive mechanisms connected to the small-stroke wedge mechanism;

The small-stroke wedge mechanism includes:

connecting the triangular plate of the reed, the triangular plate is connected to the upper plate through a flexible connecting block;

A leveling and focusing roller arranged at the lower part of the triangular plate;

Guide rails fixed on the leveling and focusing bottom plate;

A wedge-shaped block arranged on the guide rail, the upper surface of the wedge-shaped block has a slope, and the wedge-shaped block can slide along the guide rail;

The small-stroke driving mechanism includes:

an adapter plate connected to the wedge;

A screw provided on the other side of the adapter plate, the screw drives the adapter plate to generate horizontal displacement through the nut;

a drive motor connected to the screw;

A number of anti-backlash tension springs connecting the adapter plate and the drive motor eliminate the backlash of the screw and improve positioning accuracy;

The small-stroke leveling and focusing mechanism also includes several measurement feedback modules corresponding to the small-stroke wedge mechanism; and a control drive module connecting the measurement feedback modules and the drive motor;

The small-stroke leveling and focusing mechanism also includes several springs connecting the leveling and focusing bottom plate and the reed;

The large stroke adjustment mechanism includes:

floor;

Several arc guide rails set on the bottom plate;

a wedge drive plate arranged on the arc guide rail, the drive plate has several free ends, and the free ends can slide along the arc guide rail;

Several large stroke wedge mechanisms arranged on the free end of the wedge drive plate;

a large-stroke driving mechanism connected to the wedge-shaped driving plate;

A plurality of leveling and focusing base plate guide mechanisms arranged on the base plate, which limit the leveling and focusing base plate to move only in the Z direction;

The described large-stroke wedge mechanism includes:

Rollers arranged on the lower side of the leveling and focusing bottom plate;

a large stroke wedge block arranged on the free end of the wedge drive plate;

It also includes a wedge adjustment mechanism connected to the large-stroke wedge. During assembly, the initial installation position of the large-stroke wedge can be adjusted through the wedge adjustment mechanism, thereby adjusting the assembly parallelism of the leveling and focusing platform;

The described large-stroke driving mechanism includes:

an adapter for connecting the wedge drive plate;

a screw provided on the adapter, the screw drives the adapter to generate displacement through the nut;

A large-stroke drive motor connected to the screw;

Several anti-backlash tension springs connecting the adapter plate and the large-stroke drive motor eliminate the backlash of the screw and improve positioning accuracy;

The leveling and focusing bottom plate guide mechanism includes:

The vertical guide rail arranged on the base plate is installed on the base plate through the guide rail mounting block;

A slider adapter set on the vertical guide rail, the upper end of the slider adapter is connected to the lower part of the leveling and focusing base plate, and can slide along the vertical guide rail;

A number of tension springs connecting the base plate and the leveling and focusing base plate, so that the leveling and focusing base plate is tightly combined with the large stroke wedge mechanism;

The large-stroke adjusting mechanism also includes a control module connecting the large-stroke wedge mechanism and the large-stroke driving mechanism.

The working principle of the present invention is as follows:

Large stroke adjustment in the Z direction: the control module controls the rotation of the motor to drive the screw to rotate. Through the nut and the adapter, the rotation of the screw is converted into the rotation of the wedge-shaped drive plate along the arc guide rail, so that the large-stroke wedge moves in a straight line. Driven by the wedge-shaped block with large stroke, it drives the leveling and focusing bottom plate to move linearly in the Z direction to realize silicon wafer thickness compensation;

Small stroke adjustment in the Z direction: According to the data fed back by the measurement feedback module, the drive module is controlled to drive the motor to transmit the rotation to the screw, through the nut and the adapter plate, and finally convert the rotation of the motor into the linear motion of the wedge, which is driven by the wedge Down, the leveling and focusing roller drives the triangular plate to move linearly along the Z direction, thereby driving the upper plate to realize three-degree-of-freedom motion compensation in the vertical direction.

A leveling and focusing mechanism with a large stroke adjustment function provided by the present invention realizes Z-direction large-stroke adjustment and Z-direction micro-adjustment, improves dynamic performance and adjustment accuracy, and the positioning accuracy of Z-direction large-stroke adjustment can reach micron level , the motion track is linear, the control logic is simple, and the positioning accuracy of Z-direction small stroke adjustment can reach tens of nanometers, which is suitable for different applications and different thickness specifications of silicon wafers.

Description of drawings

Fig. 1 is a structural schematic diagram of a leveling and focusing mechanism with a large stroke adjustment function provided by the present invention;

Fig. 2 is a structural schematic diagram of a small stroke leveling and focusing mechanism of a leveling and focusing mechanism with a large stroke adjustment function provided by the present invention;

Fig. 3 is a top view of the small stroke leveling and focusing mechanism in Fig. 2;

Fig. 4 is a structural schematic diagram of a small-stroke wedge mechanism and a small-stroke driving mechanism of a leveling and focusing mechanism with a large stroke adjustment function provided by the present invention;

Fig. 5 is the top view of small-stroke wedge mechanism and small-stroke driving mechanism in Fig. 4;

Fig. 6 is a structural schematic diagram of a large-stroke adjustment mechanism of a leveling and focusing mechanism with a large-stroke adjustment function provided by the present invention;

Fig. 7 is a perspective view of the large stroke adjustment mechanism in Fig. 6 .

Detailed ways

Below according to Fig. 1～Fig. 7, the preferred embodiment of the present invention is described in detail:

As shown in Figure 1, the present invention provides a leveling and focusing mechanism with a large stroke adjustment function, including:

A small-stroke leveling and focusing mechanism and a large-stroke adjusting mechanism arranged at the lower part of the small-stroke leveling and focusing mechanism;

As shown in Figures 2 and 3, the small stroke leveling and focusing mechanism includes:

Leveling and focusing bottom plate 7;

The center is arranged on the reed 2 on the leveling and focusing base plate 7, and the reed 2 has several free ends;

upper plate 1;

Several small-stroke wedge-shaped mechanisms connecting the free ends of the reed 2 and the upper plate 1;

Several small-stroke drive mechanisms connected to the small-stroke wedge mechanism;

As shown in Figure 4 and Figure 5, the described small stroke wedge mechanism includes:

The triangular plate 3 connected to the reed 2, the triangular plate 3 is connected to the upper plate 1 through a flexible connecting block 14;

The leveling and focusing roller 4 arranged at the lower part of the triangular plate 3;

The guide rail 6 fixed on the leveling and focusing base plate 7;

The wedge block 5 arranged on the guide rail 6, the upper surface of the wedge block 5 has a slope, and the wedge block can slide along the guide rail 6;

As shown in Figure 4 and Figure 5, the described small stroke drive mechanism includes:

connecting the adapter plate 10 of the wedge block 5;

The screw rod 9 arranged on the other side of the adapter plate 10, the screw rod 9 drives the adapter plate 10 to generate horizontal displacement through the nut 12;

Connect the driving motor 8 of the screw rod 9;

Several anti-backlash extension springs 11 connecting the adapter plate 10 and the drive motor 8 eliminate the backlash of the screw rod 9 and improve positioning accuracy;

The small-stroke leveling and focusing mechanism also includes several measurement feedback modules corresponding to the small-stroke wedge mechanism; and a control drive module connecting the measurement feedback modules and the drive motor;

The small-stroke leveling and focusing mechanism also includes several springs 15 connecting the leveling and focusing bottom plate 7 and the reed 2;

As shown in Figures 6 and 7, the large stroke adjustment mechanism includes:

Bottom plate 106;

Several arc guide rails 113 arranged on the bottom plate 106;

The wedge block driving plate 107 arranged on the arc guide rail 113 has several free ends, and the free ends can slide along the arc guide rail 113;

Several large stroke wedge mechanisms arranged on the free end of the wedge drive plate 107;

a large-stroke driving mechanism connected to the wedge-shaped driving plate;

A number of leveling and focusing base plate guide mechanisms arranged on the base plate 106, which limit the leveling and focusing base plate 7 to move only in the Z direction;

The described large-stroke wedge mechanism includes:

The roller 100 arranged on the lower side of the leveling and focusing bottom plate 7;

The large stroke wedge block 101 that is arranged on the free end of the wedge drive plate 107;

It also includes a wedge adjustment mechanism 102 connected to the large-stroke wedge 101. During assembly, the initial installation position of the large-stroke wedge 101 can be adjusted through the wedge adjustment mechanism 102, thereby adjusting the assembly parallelism of the leveling and focusing platform. Spend;

The described large-stroke driving mechanism includes:

connecting the adapter piece 111 of the wedge drive plate 107;

The screw 112 arranged on the adapter 111, the screw 112 drives the adapter 111 to generate displacement through the nut 110;

A large stroke drive motor 108 connected to the screw rod 112;

A plurality of anti-backlash extension springs 109 connecting the adapter 111 and the large-stroke drive motor 108 eliminate the backlash of the screw rod and improve positioning accuracy;

The leveling and focusing bottom plate guide mechanism includes:

The vertical guide rail 104 arranged on the base plate 106 is installed on the base plate 106 through the guide rail mounting block 105;

The slider adapter 103 arranged on the vertical guide rail 104, the upper end of the slider adapter 103 is connected to the lower part of the leveling and focusing bottom plate 7, and can slide along the vertical guide rail 104;

A plurality of tension springs 114 connecting the base plate 106 and the leveling and focusing base plate 7, so that the leveling and focusing base plate 7 is tightly combined with the large stroke wedge mechanism;

The large-stroke adjusting mechanism also includes a control module connecting the large-stroke wedge mechanism and the large-stroke driving mechanism.

In this embodiment, Z-direction large-stroke adjustment is performed, and three sets of large-stroke wedge-shaped mechanisms and leveling and focusing base plate guiding mechanisms are respectively provided. The large-stroke movement is measured and controlled by a rotary encoder. First, the rotation of the motor 108 is controlled to drive the screw 112 to rotate. Through the nut 110 and the adapter 111, the rotation of the screw rod 112 is converted into the rotation of the wedge-shaped drive plate 107 along the arc guide rail 113, so that the large-stroke wedge 101 moves linearly, and the roller 100 is driven by the large-stroke wedge 101. Next, it drives the leveling and focusing base plate 7 to move linearly in the Z direction to realize silicon wafer thickness compensation.

When adjusting the Z-direction small stroke, three sets of the same small-stroke wedge mechanism and small-stroke driving mechanism realize the three-degree-of-freedom control of leveling and focusing. The small-stroke wedge mechanism is respectively located at A1, A2 and A3 in Figure 3. The point determines a plane. According to the data fed back by the three displacement sensors (or eddy current sensors, etc.) located at 16a, 16b, and 16c, the drive module is controlled to drive the motor 8 to transmit the rotation to the screw 9, passing through the nut 12 and the adapter plate 10 , and finally convert the rotation of the motor into the linear motion of the wedge block 5. Under the push of the wedge block 5, the leveling and focusing roller 4 drives the triangular plate 3 to move linearly along the Z direction, thereby driving the upper plate 1 to realize the vertical movement Three degrees of freedom motion compensation.

A leveling and focusing mechanism with a large stroke adjustment function provided by the present invention realizes Z-direction large-stroke adjustment and Z-direction micro-adjustment, improves dynamic performance and adjustment accuracy, and the positioning accuracy of Z-direction large-stroke adjustment can reach micron level , the motion track is linear, the control logic is simple, and the positioning accuracy of Z-direction small stroke adjustment can reach tens of nanometers, which is suitable for different applications and different thickness specifications of silicon wafers.

Claims (8)

1. A leveling and focusing mechanism with a large stroke adjustment function, characterized in that it comprises: A small-stroke leveling and focusing mechanism and a large-stroke adjusting mechanism arranged at the lower part of the small-stroke leveling and focusing mechanism; The small-stroke leveling and focusing mechanism includes: Leveling and focusing bottom plate (7); the reed (2) centered on the leveling and focusing bottom plate (7), the reed (2) has a number of free ends; upper plate (1); connected to the reed (2) some small-stroke wedge mechanisms of the free end and the upper plate (1); some small-stroke driving mechanisms connected to the small-stroke wedge mechanisms; The large stroke adjustment mechanism includes: Bottom plate (106); Some circular arc guide rails (113) that are arranged on the bottom plate (106); The wedge block drive plate (107) that is arranged on the described circular arc guide rail (113), this drive plate (107) has some free end, the free end can slide along the arc guide rail (113); several large-stroke wedge mechanisms arranged on the free end of the wedge-shaped drive plate (107); a large-stroke drive mechanism connected to the wedge-shaped drive plate; Several leveling and focusing bottom plate guide mechanisms arranged on the bottom plate (106). 2. The leveling and focusing mechanism with a large stroke adjustment function as claimed in claim 1, wherein the small stroke wedge mechanism comprises: connecting the triangular plate (3) of the reed (2), the triangular plate (3) is connected to the upper plate (1) through a flexible connecting block (14); A leveling and focusing roller (4) arranged on the lower part of the triangular plate (3); A guide rail (6) fixed on the leveling and focusing base plate (7); The wedge block (5) arranged on the guide rail (6), the upper surface of the wedge block (5) has a slope, and the wedge block can slide along the guide rail (6). 3. The leveling and focusing mechanism with a large stroke adjustment function as claimed in claim 1, wherein the small stroke driving mechanism comprises: connecting the adapter plate (10) of the wedge block (5); The screw rod (9) arranged on the other side of the adapter plate (10), the screw rod (9) drives the adapter plate (10) to generate horizontal displacement through the nut (12); Connect the driving motor (8) of described screw rod (9); A plurality of anti-backlash extension springs (11) connecting the adapter plate (10) and the driving motor (8). 4. The leveling and focusing mechanism with a large stroke adjustment function as claimed in claim 1, wherein the small stroke leveling and focusing mechanism further comprises a plurality of measurement feedback modules corresponding to the small stroke wedge mechanism; And the control driving module connecting the measurement feedback module and the driving motor; also includes several springs (15) connecting the leveling and focusing bottom plate (7) and the reed (2). 5. The leveling and focusing mechanism with a large stroke adjustment function as claimed in claim 1, wherein the large stroke wedge mechanism comprises: A roller (100) arranged on the lower side of the leveling and focusing base plate (7); The large-stroke wedge block (101) that is arranged on the free end of the wedge-shaped drive plate (107); It also includes a wedge block adjusting mechanism (102) connected to the large stroke wedge block (101). 6. The leveling and focusing mechanism with a large-stroke adjustment function as claimed in claim 1, wherein the large-stroke driving mechanism comprises: An adapter (111) connecting the wedge-shaped drive plate (107); A screw (112) arranged on the adapter (111), the screw (112) drives the adapter (111) through the nut (110) to generate a displacement; A large stroke drive motor (108) connected to the screw rod (112); A plurality of anti-backlash tension springs (109) connecting the adapter (111) and the large-stroke driving motor (108). 7. The leveling and focusing mechanism with a large stroke adjustment function according to claim 1, wherein the leveling and focusing bottom plate guide mechanism comprises: The vertical guide rail (104) arranged on the base plate (106) is installed on the base plate (106) through the guide rail mounting block (105); The slider adapter (103) arranged on the vertical guide rail (104), the upper end of the slider adapter (103) is connected to the lower part of the leveling and focusing base plate (7), and can be moved along the vertical guide rail (104) sliding; Several tension springs (114) connecting the base plate (106) and the leveling and focusing base plate (7). 8. The leveling and focusing mechanism with a large stroke adjustment function according to claim 1, wherein the large stroke adjustment mechanism further comprises a control module connecting the large stroke wedge mechanism and the large stroke driving mechanism.

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