CN218211270U

CN218211270U - Placement mechanism and wafer surface roughness measuring device

Info

Publication number: CN218211270U
Application number: CN202221650922.3U
Authority: CN
Inventors: 吴瑶; 周铁军; 王金灵
Original assignee: Guangdong Vital Micro Electronics Technology Co Ltd
Current assignee: Guangdong Vital Micro Electronics Technology Co Ltd
Priority date: 2022-06-28
Filing date: 2022-06-28
Publication date: 2023-01-03
Anticipated expiration: 2032-06-28

Abstract

A placing mechanism and a wafer surface roughness measuring device are provided. The placing mechanism comprises a first platform, a second platform, a slide rail and a driver; the first platform comprises a supporting horizontal plane, a first vertical stopping surface and a second vertical stopping surface, the first vertical stopping surface is perpendicular to the supporting horizontal plane, is inclined relative to the front-back direction and the left-right direction and is set to be parallel to the reference surface of the wafer, the first vertical stopping surface is used for being attached to the reference surface of the wafer, the second vertical stopping surface is perpendicular to the supporting horizontal plane and is perpendicular to the front-back direction, the second vertical stopping surface is used for being attached to one of the generatrices of the intersection points of the diameter of the wafer, which penetrates through the circle center along the front-back direction, and the circumference of the wafer, and the first vertical stopping surface and the second vertical stopping surface are matched to position the wafer; the second platform is positioned below the first platform; the sliding rail is fixed on the second platform and is in sliding fit with the first platform; the driver is used for driving the first platform. Therefore, the accuracy of wafer placement can be improved, and the measurement error of the surface roughness of the wafer can be reduced.

Description

Placement mechanism and wafer surface roughness measuring device

Technical Field

The present disclosure relates to the field of wafers, and more particularly to a placement mechanism and a wafer surface roughness measurement device.

Background

For the WCM (wave surface Measured) value (namely the Measured value of the filter Waviness Curve) for detecting the surface roughness of the sliced gallium arsenide wafer, the standard for facilitating the shipment of the preorder procedure to the subsequent procedure usually needs a surface roughness measuring instrument to measure the WCM value (the standard is less than or equal to 30 μm) of the wafer by Filtering expansion; the filtering type is Gaussian filtering, namely the process of weighted average is carried out on the whole image, and the value of each pixel point is obtained by carrying out weighted average on the value of each pixel point and other pixel values in the neighborhood.

Currently, the applicant mainly uses the side OF the wafer OF (abbreviated as OF) as a reference side (also called a datum plane) for placing the wafer measurement angle as a standard for measurement. The measuring mode is that the wafer is placed on a measuring platform of the surface roughness measuring instrument, and the measuring direction is consistent with the cutting mode and is equivalent to being vertical to the cutting line. The surface OF the diamond wire saw cutting wafer is provided with cutting lines, and the cutting lines and the OF edge can be simultaneously used as reference datum planes when the diamond wire saw cutting wafer is placed, but visual errors exist, so that the measuring direction is not consistent with the cutting direction or is not perpendicular to the cutting line; the surface OF the mortar linear cutting wafer has no grains, and only the OF edge is used as a reference, so that a large measurement error can be brought, and the conditions OF abnormal processing in the subsequent process and the like can be caused. The measuring platform consists of a movable probe and a horizontal placing table, so that the measured wafer has no substantial placing standard and relies on manual confirmation of the placing standard, thereby bringing about great measuring errors.

SUMMERY OF THE UTILITY MODEL

In view of the problems in the background art, it is an object of the present disclosure to provide a placing mechanism and a wafer surface roughness measuring apparatus, which can improve the accuracy of placing a wafer and reduce the measurement error of the wafer surface roughness.

Thus, in some embodiments, a placement mechanism for wafer surface roughness measurement includes a first stage, a second stage, a slide rail, and a drive; the first platform comprises a supporting horizontal plane, a first vertical stopping surface and a second vertical stopping surface, the supporting horizontal plane, the first vertical stopping surface and the second vertical stopping surface form a space for accommodating the wafer in an enclosing mode, the supporting horizontal plane extends along the front-back direction and the left-right direction, the first vertical stopping surface is perpendicular to the supporting horizontal plane, inclines relative to the front-back direction and the left-right direction and is set to be parallel to the reference surface of the wafer, the first vertical stopping surface is used for being attached to the reference surface of the wafer, the second vertical stopping surface is perpendicular to the supporting horizontal plane and is perpendicular to the front-back direction, the second vertical stopping surface is connected with one end of the first vertical stopping surface, the second vertical stopping surface is used for being attached to one of generatrices of intersection points of the diameter of the wafer, the diameter of the wafer penetrates through the circle center along the front-back direction, and the wafer is located by matching of the first vertical stopping surface and the second vertical stopping surface; the second platform is positioned below the first platform, and the second platform is spaced from the first platform in the up-down direction; the sliding rail is fixed on the second platform, extends along the left-right direction, and is in sliding fit with the first platform to form a sliding pair moving in the left-right direction; the driver is used for driving the first platform so as to enable the first platform to move in the left-right direction along the slide rail, and further enable the wafer carried and positioned by the first platform to move to the measurement starting point position of the measurement mechanism in the left-right direction.

In some embodiments, the height of the first vertical stop surface and the second vertical stop surface in the up-down direction is set to be not less than the thickness of the wafer.

In some embodiments, the length of the first vertical stop surface is set to be not less than the length of the reference surface of the wafer; the length of the second vertical stop surface is set to be not less than the diameter of the wafer.

In some embodiments, the first platform further comprises a third vertical plane perpendicular to the support horizontal plane and perpendicular to the left-right direction; the third vertical surface is connected to the other end of the first vertical stop surface.

In some embodiments, the top edges of the first vertical stop surface, the second vertical stop surface, and the third vertical surface are coplanar.

In some embodiments, the reference plane of the wafer is at an angle of 135 ° to the second vertical stop plane; the included angle between the first vertical stop surface and the second vertical stop surface is 135 degrees.

In some embodiments, the first platform is provided with internal threads extending in a left-right direction; the driver comprises a supporting seat, a screw and a cap part; the supporting seat is fixed on the second platform and is provided with a threaded hole; the screw is used for screwing the threaded hole of the supporting seat and is in threaded connection with the internal thread of the first platform, the length of the screw is greater than the length of the internal thread of the first platform along the left-right direction, and the length of the screw is set to meet the requirement that the first platform moves along the sliding rail in the left-right direction so that the loaded wafer moves to the measurement starting point position of the measurement mechanism along the left-right direction; the cap part is located the outer end of screw rod and is located the outside of the left and right directions of supporting seat, and the cap part supplies operating personnel to grasp and exert torsion to make the screw rod advance through the screw hole cooperation with the supporting seat and the screw rod enters into the most inboard of the left and right directions of the internal thread of first platform, and then make first platform slide to the measurement starting point position of measuring mechanism along the slide rail.

In some embodiments, the placing mechanism comprises a positioning block, the positioning block is arranged on the second platform and is positioned on the opposite side of the first platform from the driver, and the positioning block is used for stopping the first platform sliding along the slide rail and the position of the first platform sliding along the slide rail, which is stopped by the positioning block, is a measurement starting position of the measuring mechanism; the placing mechanism further comprises a marker which is arranged on the second platform and is positioned on one side of the first platform opposite to the second vertical stopping surface along the front-back direction, and the marker is used for stopping the drive of the driver when the intersection point of the circumferences of the wafers moving along with the first platform and the marker are positioned on the diameter along the front-back direction.

In some embodiments, the placing mechanism further comprises a magnet located between the measuring mechanism and the second platform in the up-down direction to attract the second platform to the measuring mechanism.

In some embodiments, a wafer surface roughness measurement device comprises: the aforementioned placement mechanism; and a measuring mechanism for measuring the surface roughness of the wafer.

The beneficial effects of this disclosure are as follows: the first vertical stopping face and the second vertical stopping face are matched to realize the positioning of the wafer on two sides, the wafer placing standard effect is achieved, the position of the intersection point on the first platform is fixed, and compared with the manual wafer placing or only the wafer placing with a reference surface, the wafer placing position precision and the wafer placing efficiency are improved, and further the subsequent wafer surface roughness measuring precision (namely the measuring error is reduced) is ensured.

Drawings

Fig. 1 is a schematic view of a wafer surface roughness measurement device according to the present disclosure.

Fig. 2 is a schematic view of a placement mechanism of a wafer surface roughness measurement device according to the present disclosure, wherein a wafer is not placed thereon.

Wherein the reference numerals are as follows:

141a screw hole of 100 wafer surface roughness measuring device

D1 front and back direction 142 screw rod

D2 left and right 143 caps

D3 vertical 15 locating block

1 Placement mechanism 16 marker

11 first platform 17 magnet

111 support level 2 measuring mechanism

112 first vertical stop surface 21 support table

113 second vertical stop surface 22 probe

114 third vertical surface 23 first mover

115 second mover with internal threads 24

S space 200 wafer

12 second platform 200a datum plane

13 center of slide rail O

14 driver P intersection

141 support seat

Detailed Description

The accompanying drawings illustrate embodiments of the present disclosure and it is to be understood that the disclosed embodiments are merely examples of the disclosure, which can be embodied in various forms, and therefore, specific details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present disclosure.

Referring to fig. 1 and 2, the wafer surface roughness measuring apparatus 100 includes a placing mechanism 1 and a measuring mechanism 2.

The placement mechanism 1 is used for wafer surface roughness measurement. The placing mechanism 1 includes a first stage 11, a second stage 12, a slide rail 13, and a driver 14.

The first platform 11 includes a supporting horizontal surface 111, a first vertical stop surface 112 and a second vertical stop surface 113, and the supporting horizontal surface 111, the first vertical stop surface 112 and the second vertical stop surface 113 enclose a space S for accommodating the wafer 200, i.e., the space S is a recess enclosed by the supporting horizontal surface 111, the first vertical stop surface 112 and the second vertical stop surface 113. In the example shown in the drawing, the space S is open on the side away from the second vertical stop surface 113 in the front-rear direction D1, on the side away from the first vertical stop surface 112 in the left-right direction D2, and on the side away from the support horizontal surface 111 in the up-down direction D3. The outer contour of the projection of the first stage 11 in the up-down direction D3 is not limited, and may be, but is not limited to, a square. The size of the space S is determined according to the external dimensions of the wafer 200 to be measured, for example, suitable for the measurement of 1 inch, 2 inch, 3 inch and above wafers 200.

The support horizontal plane 111 extends in the front-rear direction D1 and the left-right direction D2, i.e., the support horizontal plane 111 extends on a horizontal plane, and the horizontal support plane 111 supports the surface of one side in the thickness direction of the wafer 200, thereby ensuring the accuracy of the surface roughness measurement of the surface of the other side in the thickness direction (upper side in the drawing) of the wafer 200.

The first vertical stop surface 112 is perpendicular to the support horizontal plane 111 and inclined with respect to the front-back direction D1 and the left-right direction D2 and set to be parallel to a reference surface (also referred to as a reference edge) 200a OF the wafer 200, and the first vertical stop surface 112 is for being attached to the reference surface 200a OF the wafer 200. That is, the placing mechanism 1 is applied to the wafer 200 with the reference surface 200a, and the first vertical stopper surface 112 is brought into abutment with the reference surface 200a of the wafer 200 to effect positioning of the wafer 200 in a side direction (although the side direction is not parallel to either the front-rear direction D1 or the left-right direction D2). In the example shown in the figures, the first vertical stop surface 112 is located at one corner of the first platform 11 and spans two edges at that corner.

The second vertical stop surface 113 is perpendicular to the support horizontal surface 111 and perpendicular to the front-back direction D1, the second vertical stop surface 113 is connected to one end of the first vertical stop surface 112, the second vertical stop surface 113 is configured to be attached to one of the generatrices of the wafer 200 at the intersection point P of the diameter of the wafer 200 passing through the circle center O along the front-back direction D1 and the circumference of the wafer 200, and the first vertical stop surface 112 and the second vertical stop surface 113 cooperate to position the wafer 200. The second vertical stop surface 113 realizes the positioning of the wafer 200 at the other side, the first vertical stop surface 112 and the second vertical stop surface 113 cooperate to realize the positioning of the wafer 200 at both sides, which plays a role of placing the wafer 200 in a standard manner, the position of the intersection point P on the first platform 11 is fixed, and compared with the manual placement of the wafer 200 or the placement of the wafer 200 only by using the reference surface 200a, the accuracy and the efficiency of the placement position of the wafer 200 are improved, and further the accuracy of the subsequent wafer surface roughness measurement (i.e. the measurement error is reduced) is ensured.

As shown in the drawing, the height of the first and second

vertical stop surfaces

112 and 113 in the up-down direction D3 is set to be not less than the thickness of the wafer 200. Thus, the surface to be surface roughness measured on one side of the wafer 200 in the thickness direction is not limited by the first vertical stop surface 112 and the second vertical stop surface 113, and convenience in surface roughness measurement is improved.

As shown in the figure, the length of the first vertical stop surface 112 is set to be not less than the length of the reference surface 200a of the wafer 200; the length of the second vertical stop surface 113 is set to be not less than the diameter of the wafer 200. Thereby improving the convenience of positioning and the stability of positioning of the wafer 200.

As shown, the first platform 11 further includes a third vertical surface 114, the third vertical surface 114 being perpendicular to the support horizontal surface 111 and perpendicular to the left-right direction D2; the third vertical surface 114 is connected to the other end of the first vertical stop surface 112. By the arrangement of the third vertical surface 114, the limit position on one side in the left-right direction D2 is increased, so that the wafer 200 does not protrude outward from the position where the third vertical surface 114 is located when being placed in the space S, and the function of assisting the positioning when placing the wafer 200 is performed.

As shown, the top edges of the first, second and third

vertical stop surfaces

112, 113, 114 are coplanar. Therefore, the equal thickness of the wafer 200 can be matched, the size consistency of the positions of the first vertical stop surface 112 and the second vertical stop surface 113 for positioning the wafer 200 in the vertical direction D3 is improved, and the stability of surface roughness measurement of the wafer 200 is improved.

As shown, in one example, the reference plane 200a of the wafer 200 is at an angle of 135 ° to the second vertical stop plane 113; the angle between the first vertical stop surface 112 and the second vertical stop surface 113 is 135 °. That is, the angle between the reference plane 200a of the wafer 200 and the extension line in the left-right direction D2 at the intersection point P is 135 °, and is suitable for the gallium arsenide wafer produced by the applicant.

The second stage 12 is located below the first stage 11, and the second stage 12 is spaced apart from the first stage 11 in the up-down direction D3. The size and the limitation of the second platform 12 are not limited as long as the layout of the related components (e.g., the slide rail 13, and a positioning block 15, a marker 16, etc., which will be described later) is satisfied.

The slide rail 13 is fixed on the second platform 12, the slide rail 13 extends along the left-right direction D2, and the slide rail 13 is slidably matched with the first platform 11 to form a sliding pair moving in the left-right direction D2. In one example, the slide rails 13 are plural and arranged at intervals in the front-rear direction D1. The slide rails 13 serve to stably translate the first platform 11.

The driver 14 is configured to drive the first stage 11 so as to move the first stage 11 in the left-right direction D2 along the slide rail 13, and further, to move the wafer 200 carried and positioned by the first stage 11 to the measurement start position of the measurement mechanism 2 in the left-right direction D2.

The driver 14 may take any suitable configuration.

In the example illustrated in the figures, the drive 14 comprises a support seat 141, a screw 142 and a cap 143.

The support 141 is fixed to the second stage 12, the support 141 is provided with a screw hole 141a, and accordingly, the first stage 11 is provided with an internal screw 115 extending in the left-right direction D2.

The screw 142 is used for screwing into the threaded hole 141a of the support seat 141 and screwing with the internal thread 115 of the first platform 11, the length of the screw 142 is greater than the length of the internal thread 115 of the first platform 11 along the left-right direction D2, and the length of the screw 142 is set to satisfy the requirement that the first platform 11 moves along the slide rail 13 along the left-right direction D2 to move the loaded wafer 200 to the measurement starting position of the measurement mechanism 2 along the left-right direction D2.

The cap 143 is located at the outer end of the screw 142 and located outside the support seat 141 in the left-right direction D2, and the cap 143 is grasped by an operator to apply a torque force, so that the screw 142 travels through engagement with the threaded hole 141a of the support seat 141 and the screw 142 enters the innermost side of the internal thread 115 of the first platform 11 in the left-right direction D2, thereby sliding the first platform 11 along the slide rail 13 to the measurement starting point position of the measurement mechanism 2.

Referring to fig. 1 and 2, the placing mechanism 1 includes a positioning block 15, the positioning block 15 is disposed on the second platform 12 and located on the opposite side of the first platform 11 from the driver 14, and the positioning block 15 is used for stopping the first platform 11 sliding along the slide rail 13 and the position where the first platform 11 sliding along the slide rail 13 is stopped by the positioning block 15 is a measurement starting position of the measuring mechanism 2. By the arrangement of the positioning block 15, it is possible to eliminate the manual check of whether the wafer 200 carried by the first stage 11 reaches the measurement start position of the measurement mechanism 2.

Referring to fig. 1 and 2, in order to enhance confirmation of the measurement start point position, the placing mechanism 1 further includes a flag 16, the flag 16 being disposed on the second stage 12 on the opposite side of the first stage 11 from the second vertical stop surface 113 in the front-rear direction D1, the flag 16 being for stopping the drive of the driver 14 when an intersection point P of the circumference of the wafer 200 moving with the first stage 11 and the flag 16 are on a diameter in the front-rear direction D1. When the marker 16 is used in cooperation with the positioning block 15, it serves to double-confirm that the wafer 200 carried by the first stage 11 reaches the measurement start position of the measuring mechanism 2. The marker 16 may be provided with a sharp corner, the apex of which is used to connect with the point of intersection P, as shown, in order to visually check whether the wafer 200 carried by the first stage 11 reaches the measurement start position of the measuring mechanism 2.

Referring to fig. 1 and 2, the placing mechanism 1 further includes a magnet 17, and the magnet 17 is located between the measuring mechanism 2 (specifically, the support table 21) and the second stage 12 in the up-down direction D3 to attract the second stage 12 to the detecting mechanism 2 (specifically, the support table 21 described later). By adopting the magnet 17, the independence of the placing mechanism 1 and the measuring mechanism 2 is achieved, and the operation of placing the wafer 200 on the placing mechanism 1 can be performed independently, improving the efficiency of batch measurement of the wafers 200.

The measuring mechanism 2 is used to measure the surface roughness of the wafer 200.

In the example shown in the figure, the measuring mechanism 2 includes a support table 21, a probe 22, a first mover 23, and a second mover 24.

The support table 21 is used to support the placing device 1. The probes 22 are used to measure the surface roughness of the wafer 200. The first mover 23 is connected to the probe 22 to drive the probe 22 to move in the left-right direction D2. The second mover 24 is connected to the first mover 23 to drive the first mover 23 to be raised and lowered along with the probe 22 in the up-down direction D3. The first mover 23 may be in the form of an air cylinder, a linear motor, or the like, as long as unidirectional translation is achieved. Likewise, the second mover 24 may take the form of an air cylinder, a linear motor, or the like, so long as unidirectional translation is achieved.

Note that the wafer surface roughness measurement device 100 of the present disclosure is suitable for any material of wafer with a reference surface.

The above detailed description is used to describe a number of exemplary embodiments, but is not intended to limit the combinations explicitly disclosed herein. Thus, unless otherwise specified, various features disclosed herein can be combined together to form a number of additional combinations that are not shown for the sake of brevity.

Claims

1. A placement mechanism (1) for wafer surface roughness measurement,

the placing mechanism (1) comprises a first platform (11), a second platform (12), a sliding rail (13) and a driver (14);

the first platform (11) comprises a supporting horizontal plane (111), a first vertical stop plane (112) and a second vertical stop plane (113), the supporting horizontal plane (111), the first vertical stop plane (112) and the second vertical stop plane (113) enclose a space (S) for accommodating the wafer (200), the supporting horizontal plane (111) extends along a front-back direction (D1) and a left-right direction (D2), the first vertical stop plane (112) is perpendicular to the supporting horizontal plane (111), is inclined relative to the front-back direction (D1) and the left-right direction (D2) and is set to be parallel to a reference plane (200 a) of the wafer (200), the first vertical stop plane (112) is used for being attached to a reference plane (200 a) of the wafer (200), the second vertical stop plane (113) is perpendicular to the supporting horizontal plane (111) and is attached to the front-back direction (D1), the second vertical stop plane (113) is connected with one end of the first vertical stop plane (112), the second vertical stop plane (113) is used for being attached to the wafer (200) along a diameter of a circle center point P of the wafer (200) where the wafer (200) passes through the front-back direction (D1) and the vertical stop plane (113), and the wafer (200), and the circle center point P) is located;

the second platform (12) is positioned below the first platform (11), and the second platform (12) is spaced from the first platform (11) in the up-down direction (D3);

the sliding rail (13) is fixed on the second platform (12), the sliding rail (13) extends along the left-right direction (D2), and the sliding rail (13) is in sliding fit with the first platform (11) to form a sliding pair moving in the left-right direction (D2);

the driver (14) is used for driving the first platform (11) so that the first platform (11) moves in the left-right direction (D2) along the slide rail (13), and further the wafer (200) carried and positioned by the first platform (11) moves to the measurement starting point position of the measurement mechanism (2) along the left-right direction (D2).

2. The placement mechanism (1) according to claim 1,

the heights of the first vertical stop surface (112) and the second vertical stop surface (113) in the up-down direction (D3) are set to be not less than the thickness of the wafer (200).

3. The placement mechanism (1) according to claim 1,

the length of the first vertical stop surface (112) is set to be not less than the length of the reference surface (200 a) of the wafer (200);

the length of the second vertical stop surface (113) is set to be not less than the diameter of the wafer (200).

4. The placement mechanism (1) according to claim 1,

the first platform (11) further comprises a third vertical face (114),

the third vertical surface (114) is perpendicular to the support horizontal surface (111) and perpendicular to the left-right direction (D2);

the third vertical surface (114) is connected to the other end of the first vertical stop surface (112).

5. Placement mechanism (1) according to claim 4,

the top edges of the first vertical stop surface (112), the second vertical stop surface (113) and the third vertical surface (114) are coplanar.

6. The placement mechanism (1) according to claim 1,

the included angle between the reference surface (200 a) of the wafer (200) and the second vertical stop surface (113) is 135 degrees;

the included angle between the first vertical stop surface (112) and the second vertical stop surface (113) is 135 degrees.

7. The placement mechanism (1) according to claim 1,

the first platform (11) is provided with internal threads (115) extending in the left-right direction (D2);

the driver (14) comprises a support seat (141), a screw rod (142) and a cap part (143);

the supporting seat (141) is fixed on the second platform (12), and the supporting seat (141) is provided with a threaded hole (141 a);

the screw (142) is used for screwing into the threaded hole (141 a) of the supporting seat (141) and is in threaded connection with the internal thread (115) of the first platform (11), the length of the screw (142) is greater than the length of the internal thread (115) of the first platform (11) along the left-right direction (D2), and the length of the screw (142) is set to meet the requirement that the first platform (11) moves along the slide rail (13) in the left-right direction (D2) so that the loaded wafer (200) moves to the measurement starting point position of the measurement mechanism (2) along the left-right direction (D2);

the cap part (143) is located at the outer end of the screw rod (142) and located on the outer side of the support seat (141) in the left-right direction (D2), the cap part (143) is used for being grasped by an operator to apply torsion, so that the screw rod (142) runs through being matched with the threaded hole (141 a) of the support seat (141) and the screw rod (142) enters the innermost side of the left-right direction (D2) of the internal thread (115) of the first platform (11), and the first platform (11) is further made to slide to the measurement starting point position of the measuring mechanism (2) along the slide rail (13).

8. The placement mechanism (1) according to claim 1,

the placing mechanism (1) comprises a positioning block (15), the positioning block (15) is arranged on the second platform (12) and is located on the side, opposite to the driver (14), of the first platform (11), and the positioning block (15) is used for stopping the first platform (11) which slides along the sliding rail (13) and the first platform (11) which slides along the sliding rail (13) to be measured by the measuring mechanism (2) at a starting point position;

the placing mechanism (1) further comprises a marker (16), the marker (16) is arranged on the second platform (12) and is located on the opposite side of the first platform (11) from the second vertical stop surface (113) along the front-back direction (D1), and the marker (16) is used for stopping the drive of the driver (14) when the intersection point (P) of the circumferences of the wafers (200) moving along with the first platform (11) and the marker (16) are on the diameter along the front-back direction (D1).

9. The placement mechanism (1) according to claim 1,

the placement mechanism (1) further comprises a magnet (17), and the magnet (17) is located between the measuring mechanism (2) and the second platform (12) along the up-down direction (D3) so as to adsorb the second platform (12) on the measuring mechanism (2).

10. A wafer surface roughness measurement device (100), comprising:

-a placement mechanism (1) according to any one of claims 1-9; and

a measuring mechanism (2) for measuring the surface roughness of the wafer (200).