CN111482894B

CN111482894B - Wafer loading cup

Info

Publication number: CN111482894B
Application number: CN202010398119.4A
Authority: CN
Inventors: 赵德文; 孟松林; 温世乾; 刘远航
Original assignee: Huahaiqingke Co Ltd
Current assignee: Huahaiqingke Co Ltd
Priority date: 2020-05-12
Filing date: 2020-05-12
Publication date: 2021-02-09
Anticipated expiration: 2040-05-12
Also published as: CN111482894A

Abstract

The invention discloses a wafer loading cup, which comprises: the cup body is used for supporting the bearing head and comprises a circular side wall and a disc-shaped bottom, and the bottom is provided with a through positioning hole; a tray disposed in a sidewall of the cup to receive a wafer; a connector composed of a disk-shaped disk portion and a shaft portion, the disk portion being coaxially connected to the bottom of the tray and having a through mounting hole vertically aligned with the positioning hole; a driving device connected with the shaft portion of the connecting member to drive the tray to vertically move; and a guide rod including a tip portion mounted on the top surface of the link and a body portion passing through the mounting hole of the disk portion of the link and slidably extending through the positioning hole of the bottom of the cup; the guide rod is connected with the mounting hole of the disk part of the connecting piece in a sliding mode, and the guide rod is parallel to the shaft part of the connecting piece.

Description

Wafer loading cup

Technical Field

The invention belongs to the technical field of chemical mechanical polishing, and particularly relates to a wafer loading cup.

Background

Chemical Mechanical Polishing (CMP) is a global, ultra-precise surface processing technique. Chemical mechanical polishing equipment generally comprises an equipment front end, a polishing part and a cleaning part, wherein a wafer to be processed is conveyed to the polishing part and the cleaning part from the equipment front end, and the wafer realizes the removal of materials in a dry-in and dry-out mode.

The polishing part generally includes a plurality of polishing units, and in order to achieve smooth transfer of the wafer, a wafer loading cup (Load cup), also called a wafer exchange device, a wafer transfer device, and a wafer transfer device, which is a transfer module for transferring the wafer between the polishing unit and the transfer robot, are disposed in the vicinity of the polishing units.

Patent CN109909870A provides a loading cup comprising: a cup having an interior space; a susceptor disposed in the inner space, capable of ascending or descending, and loading or unloading a wafer onto or from a polishing head. CN207358839U discloses a chemical mechanical polishing apparatus including a wafer loading and unloading device, wherein a loading cup is used for loading or unloading a wafer to a polishing head.

The stable operation of the wafer loading cup is a prerequisite for efficient wafer transfer, which is closely related to the WPH (wafer per hour) of the chemical mechanical polishing equipment. Stable operation of the wafer loading cup is a technical problem that those skilled in the art are continuously improving.

Disclosure of Invention

The present invention aims to solve at least to some extent one of the technical problems existing in the prior art. To this end, the present invention discloses a wafer loading cup, comprising: the cup body is used for supporting the bearing head and comprises a circular side wall and a disc-shaped bottom, and the bottom is provided with a through positioning hole; a tray disposed in a sidewall of the cup to receive a wafer; a connector composed of a disk-shaped disk portion and a shaft portion, the disk portion being coaxially connected to the bottom of the tray and having a through mounting hole vertically aligned with the positioning hole; a driving device connected with the shaft portion of the connecting member to drive the tray to vertically move; and a guide rod including a tip portion mounted on the top surface of the link and a body portion passing through the mounting hole of the disk portion of the link and slidably extending through the positioning hole of the bottom of the cup; the guide rod is connected with the mounting hole of the disk part of the connecting piece in a sliding mode, and the guide rod is parallel to the shaft part of the connecting piece.

As a preferred embodiment, there is a gap between the top end portion of the guide bar and the bottom of the tray above it, so that the guide bar can move in the vertical direction within the distance of the gap.

As a preferred embodiment, the guide bar is made of a metal material that does not contain aluminum and copper.

As a preferred embodiment, the connecting piece is made of plastic.

As a preferred embodiment, the guide bar is made of stainless steel.

As a preferred embodiment, the connection piece is made of PEEK, PET, PTFE and/or ABS.

As a preferred embodiment, the clearance between the top end part of the guide rod and the bottom of the tray above the guide rod is not more than 0.01 mm.

In a preferred embodiment, a linear bearing is arranged in the positioning hole of the cup body, and the guide rod is connected with the linear bearing in a sliding manner; the distance between the main body part of the guide rod and the mounting hole of the disc part of the connecting piece is not greater than the distance between the guide rod and the linear bearing.

As a preferred embodiment, the depth of the mounting hole of the disk part of the connecting piece is 1/8-1/5 of the length of the guide rod.

In a preferred embodiment, the distance between the main body of the guide rod and the mounting hole of the disk portion of the link is 0.005mm to 0.5 mm.

Compared with the prior art, the embodiment of the invention has the following beneficial effects: the guide rod is arranged in the wafer loading cup and matched with the precise shaft hole of the mounting hole of the connecting piece, so that the parallelism of the guide rod and the main body part of the connecting piece is effectively guaranteed. When the tray removed along vertical direction, guide bar sliding connection had effectively guaranteed the stability that the tray removed along vertical direction in the locating hole of cup.

Drawings

The advantages of the invention will become clearer and more readily appreciated from the detailed description given with reference to the following drawings, which are given by way of illustration only, and which do not limit the scope of protection of the invention, wherein:

FIG. 1 is a schematic view of a wafer loading cup according to the present invention;

FIG. 2 is an enlarged view of a portion of FIG. 1 at A;

FIG. 3 is a schematic diagram of a wafer loading cup according to the prior art;

fig. 4 is a partially enlarged view at B in fig. 3.

Detailed Description

The technical solution of the present invention will be described in detail with reference to the following embodiments and accompanying drawings. The embodiments described herein are specific embodiments of the present invention for the purpose of illustrating the concepts of the invention; the description is intended to be illustrative and exemplary and should not be taken to limit the scope of the invention. In addition to the embodiments described herein, those skilled in the art will be able to employ other technical solutions which are obvious based on the disclosure of the claims and the specification thereof, and these technical solutions include technical solutions which make any obvious replacement or modification of the embodiments described herein.

The drawings in the present specification are schematic views to assist in explaining the concept of the present invention, and schematically show the shapes of respective portions and their mutual relationships. It should be understood that the drawings are not necessarily to scale, the same reference numerals being used to identify the same elements in the drawings in order to clearly show the structure of the elements of the embodiments of the invention. In the present invention, "Chemical Mechanical Polishing" is also referred to as "Chemical Mechanical Planarization", and a substrate (substrate) is also referred to as a wafer (wafer), which means equivalent to the actual function.

Fig. 1 shows a schematic structural view of a wafer loading cup 1 according to the present invention. The wafer loading cup 1 includes a cup body 10, a tray 20, a connecting member 30, and a driving device 40. The cup body 10 includes a circular side wall 11 and a disk-shaped bottom 12, and the bottom 12 is provided with a through positioning hole 13. The top of the side wall 11 is provided with a step for supporting and positioning the carrier head 2. The tray 20 is disposed in the sidewall 11 of the cup 10 to receive the wafer W sucked by the carrier head 2.

The link 30 is composed of a disk portion 31 having a disk shape and a shaft portion 32. The disc portion 31 is coaxially attached to the bottom of the tray 20, and the disc portion 31 is provided with a mounting hole 311 shown in fig. 2, the mounting hole 311 being disposed in alignment with and penetrating the positioning hole 13. The driving means 40 is connected to the shaft portion 32 of the link 30 to drive the tray 20 to move vertically. Since the carrier head 2 is not generally provided with the degree of freedom in the vertical direction, the amount of movement of the carrier head 2 in the vertical direction is small even if the degree of freedom in the vertical direction is provided. Therefore, at the time of wafer transfer, the tray 20 in the wafer loading cup 1 needs to be moved upward to receive the wafer W sucked by the carrier head 2.

When the wafer is unloaded, the carrier head 2 with the wafer W sucked thereon is concentrically positioned with the step portion of the top surface of the side wall 11 of the cup body 10, thereby ensuring that the wafer W is aligned with the tray 20. In order to prevent the wafer W from falling off the tray 20 from a long distance, the driving device 40 is required to drive the tray 20 to move vertically upward so as to reduce the distance between the wafer W at the bottom of the carrier head 2 and the top surface of the tray 20. The wafer W can be smoothly unloaded onto the top surface of the tray 20 moved to the high position by the driving device 40.

In the embodiment shown in fig. 1, the driving means 40 is a pneumatic cylinder, and the shaft portion 32 of the connecting member 30 is connected to a piston rod of the pneumatic cylinder. Since the shaft portion 32 of the connecting member 30 and the driving shaft of the driving device 40 are cylindrical components, the driving shaft of the driving device 40 may rotate slightly in the circumferential direction with the shaft portion 32 of the connecting member 30 during the process of pushing the tray 20 to move by the driving device 40. Since the driving means 40 is connected to the cup 10 and the connecting member 30 is connected to the tray 20, the slight rotation in the circumferential direction causes a slight rotation between the tray 20 and the cup 10. If the wafer W on the top surface of the tray 20 is rotated in the circumferential direction under pressure, the wafer W on the top surface of the tray 20 may be damaged.

In order to control or prevent the tray 20 disposed in the cup 10 from rotating in the circumferential direction during the vertical movement, in the prior art, the wafer loading cup 1 'further includes a guide rod 50', as shown in fig. 3, an axis of the guide rod 50 'is disposed parallel to an axis of the shaft portion 32' of the link 30 ', and an upper end of the guide rod 50' is provided with a threaded portion, which is disposed on the disk portion 31 'of the link 30' by means of a thread. The guide bar 50 ' is slidably coupled to the positioning hole 13 ' at the bottom of the cup body 10 ', and the tray 20 ' and the guide bar 50 ' move in a vertical direction. The guide bar 50 'further limits the rotation of the tray 20', i.e. prevents the rotation of the tray 20 'relative to the cup 10'.

Fig. 4 is a partially enlarged view at B in fig. 3. Since the guide bar 50 'is screw-coupled to the disk portion 31', the parallelism between the guide bar 50 'mounted to the disk portion 31' and the shaft portion 32 'of the link 30' cannot be secured. Since the parallelism of the guide bar 50 'to the shaft portion 32' of the connector 30 'cannot be secured, the guide bar 50' may be slightly inclined with respect to the shaft portion 32 'of the connector 30'. The inclined guide rods 50 ' increase a certain resistance to the lifting of the tray 20 ', thereby preventing the tray 20 ' from moving smoothly in a vertical direction. The tray 20 'may not reach a designated position within a predetermined time, and the wafer at the lower portion of the carrier head may directly fall to the top surface of the tray 20'. The direct dropping of the wafer from a certain height may cause the wafer to be broken.

In order to solve the problem of the tray being not smoothly lifted, in fig. 1, the wafer loading cup 1 further includes a guide rod 50 including a top end portion 51 and a body portion 52, wherein the top end portion 51 is mounted on the top surface of the link 30, and the body portion 52 passes through the mounting hole of the disk portion 31 of the link 30 and slidably extends through the positioning hole 13 of the bottom portion 12 of the cup 10.

The guide bar 50 is slidably coupled to the mounting hole 311 shown in fig. 2 of the disc portion 31 of the link 30. The guide rod 50 is arranged in the mounting hole 311 through a precise shaft hole, so that the parallelism between the guide rod 50 and the shaft part 32 of the connecting piece 30 is effectively ensured. The tray 20 and the guide rod 50 can move smoothly along the positioning hole 13 of the cup body 10, thereby effectively controlling the time of wafer exchange and ensuring the smoothness of wafer transmission.

Fig. 2 is a partially enlarged view of a portion a in fig. 1. The tip end 51 of the guide rod 50 is mounted on the top surface of the link 30, and the body 52 is fitted into the mounting hole 311 with a precise clearance. The outer peripheral wall of the body portion 52 is disposed at a distance from the inner side wall of the mounting hole 311. In order to ensure parallelism of the axis of the guide bar 50 and the axis of the shaft portion 32, the distance should not be greater than 0.5mm and should not be less than 0.005 mm. That is, the guide bar 50 is fitted to the mounting hole 311 of the disk unit 31 through a precise shaft hole. In the embodiment shown in fig. 1, the distance between the outer peripheral wall of the body portion 50 and the inner side wall of the mounting hole 311 is 0.01 mm. The parallelism between the axis of the guide rod 50 and the axis of the shaft portion 32 of the link 30 is controlled to be within 0.08 mm. Further, in order to ensure the parallelism of the guide bar 50 and the shaft portion 32 of the link 30, the straightness of the main body portion 52 of the guide bar 50 is controlled to be within 0.05 mm.

In order to ensure the reliability of the connection between the guide rod 50 and the disk 31, the depth of the mounting hole 311 of the disk 31 should not be too small. The depth of the mounting hole 311 of the disc portion 31 of the link 30 should be 1/8-1/5 of the length of the guide bar 50. In some embodiments, the depth of the mounting hole 311 of the disk portion 31 should be no less than 10 mm. In order to ensure the rapidity of lifting the tray 20, the tray portion 31 provided between the tray 20 and the driving device 40 should not be too thick. The depth of the mounting hole 311 of the disc portion 31 should be not more than 30 mm.

As one embodiment of the present invention, as shown in fig. 2, there is a gap 21 between a tip end portion 51 of the guide bar 50 and a bottom portion of the tray 20 above it, so that the guide bar 50 can move in the vertical direction within the distance of the gap 21. In the present embodiment, the gap 21 is not more than 0.01 mm. The provision of the gap 21 can increase the degree of freedom of the guide bar 50 in the vertical direction. That is, the guide bar 50 can be moved in the vertical direction by a proper amount to promote smooth sliding of the guide bar 50 with respect to the positioning hole 13, thereby ensuring smooth lifting of the tray 20. Furthermore, the gap 21 is provided to help ensure the parallelism of the top surface of the tray 20. Specifically, since the contact surface between the tray 20 and the connecting member 30 is a finish-machined surface, the precision connection between the tray 20 and the connecting member 30 can effectively ensure the parallelism of the top surface of the tray 20. If the gap 21 is not provided between the tip 51 of the guide bar 50 and the vertical direction of the tray 20, the guide bar 50 abuts against the bottom surface of the tray 20, which affects the precise connection between the tray 20 and the link 30, and deteriorates the parallelism of the top surface of the tray 20. In the embodiment shown in fig. 1, the gap between the tip portion 51 of the guide bar 50 and the tray 20 is 0.02 mm.

In fig. 1, the main body 52 of the guide rod 50 is a cylindrical body having an outer diameter of 5 mm. The outer diameter of the body portion 52 may be other sizes, and the outer diameter of the body portion 52 should not be larger than 20mm and not smaller than 3 mm.

As an embodiment of the present invention, the distance between the axis of the guide bar 50 and the axis of the shaft portion 32 of the link 30 should be not more than 50mm and should be not less than 20 mm. The guide rod 50 is disposed at a position related to the driving assembly 40 and a protective structure disposed outside the driving assembly 40, the guide rod 50 should be disposed inside the protective structure, meanwhile, the outer sidewall of the guide rod 50 does not interfere with the outer sidewall of the shaft portion 32, and the protective structure is disposed to prevent waste liquid generated in the polishing or cleaning process from entering a gap between the main body portion 52 and the mounting hole 311 to affect the parallelism of the guide rod 50 and the shaft portion 32 of the connecting member 30.

In order to prevent the adhesion between the guide bar 50 and the link 30, it is necessary to select different kinds of processing materials for the guide bar 50 and the link 30. In the embodiment shown in fig. 1, the connecting member 30 is preferably made of a non-metallic material, and the guide bar 50 is preferably made of a metallic material that does not contain aluminum or copper. Since aluminum and copper may form metal ion contamination, it is desirable to avoid using metal materials containing aluminum and copper to reduce the impact of the wafer loading cup on the chemical mechanical polishing. Specifically, the guide bar 50 may be made of stainless steel, which is surface-quenched to increase the surface hardness of the guide bar, the quenched thickness being 0.1mm to 0.5 mm; the coupling member 30, which is fitted precisely in the axial hole of the guide bar 50, is made of PPS. Different materials are respectively selected for the connecting piece 30 and the guide rod 50, so that the guide rod 50 and the connecting piece 30 can be effectively prevented from being adhered, and the running reliability of the guide rod 50 is ensured. It will be readily appreciated that other sufficiently strong metallic materials may be selected for the guide bar 50, such as austenitic stainless steel, 45 gauge steel, and the like. Other non-metallic materials that are chemically inert, such as PEEK, PET, PTFE, and/or ABS, may also be selected for the connector 30.

As a variation of the present invention, the guide bar 50 may also be a hollow pipe structure to increase the rigidity of the guide bar 50. The straightness of the main body 52 is controlled within 0.03mm to control the parallelism between the axis of the guide rod 50 and the axis of the shaft 32 after the guide rod 50 is precisely assembled to the disk 31, thereby ensuring smooth movement of the tray 20.

In the embodiment shown in fig. 1, a linear bearing 60 is disposed in the positioning hole 13 of the cup body 10, and the guide rod 50 is slidably connected to the linear bearing 60; the distance between the body portion 52 of the guide bar 50 and the mounting hole 311 of the disk portion 31 of the link 30 is not greater than the distance between the guide bar 50 and the linear bearing 60 to ensure the parallelism between the guide bar 50 and the shaft portion 32 of the link 30. The tray 20 moves smoothly along the vertical direction, so that the tray 20 can reach a designated position within a preset time, and the wafer on the bearing head is prevented from directly dropping to the top surface of the tray 20 in a long distance and being broken.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples" or the like mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. The above embodiments and implementation manners are only used for illustrating the technical solutions of the present invention, and are not limited or restricted thereto; although the present invention has been described with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be replaced with similar or equivalent ones; such modifications and substitutions should not be considered as included within the scope of the present invention, unless they depart from the spirit or essential characteristics or points of the present invention.

While embodiments of the invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A wafer loading cup, comprising:

the cup body is used for supporting the bearing head and comprises a circular side wall and a disc-shaped bottom, and the bottom is provided with a through positioning hole;

a tray disposed in a sidewall of the cup to receive a wafer;

a connector composed of a disk-shaped disk portion and a shaft portion, the disk portion being coaxially connected to the bottom of the tray and having a through mounting hole vertically aligned with the positioning hole;

a driving device connected with the shaft portion of the connecting member to drive the tray to vertically move;

and a guide rod including a tip portion mounted on the top surface of the link and a body portion passing through the mounting hole of the disk portion of the link and slidably extending through the positioning hole of the bottom of the cup;

the guide rod is connected with the mounting hole of the disk part of the connecting piece in a sliding mode, and the guide rod is parallel to the shaft part of the connecting piece.

2. The wafer loading cup of claim 1, wherein a gap exists between a top end portion of the guide bar and a bottom portion of the tray above the guide bar such that the guide bar is vertically movable within a distance of the gap.

3. The wafer loading cup of claim 1, wherein the guide bar is made of a metallic material that does not contain aluminum and copper.

4. The wafer loading cup of claim 1, wherein said connector is made of plastic.

5. The wafer loading cup of claim 3 wherein said guide bar is made of stainless steel.

6. The wafer loading cup of claim 4, wherein the connector is made of PEEK, PET, PTFE, and/or ABS.

7. The wafer loading cup as claimed in claim 2, wherein a gap between a top end portion of the guide bar and a bottom of the tray above the guide bar is not more than 0.01 mm.

8. The wafer loading cup of claim 1, wherein a linear bearing is disposed within the positioning hole of the cup body, and the guide rod is slidably coupled to the linear bearing; the distance between the main body part of the guide rod and the mounting hole of the disc part of the connecting piece is not greater than the distance between the guide rod and the linear bearing.

9. The wafer loading cup of claim 1, wherein the mounting hole of the disk portion of the link has a depth of 1/8-1/5 of the length of the guide bar.

10. The wafer loading cup of claim 1, wherein a distance between the body portion of the guide bar and the mounting hole of the disk portion of the link is 0.005mm to 0.5 mm.