CN112405330B

CN112405330B - Polishing device

Info

Publication number: CN112405330B
Application number: CN202011419911.XA
Authority: CN
Inventors: 杨渊思; 徐枭宇; 周智鹏
Original assignee: Hangzhou Zhonggui Electronic Technology Co ltd
Current assignee: Hangzhou Zhonggui Electronic Technology Co ltd
Priority date: 2020-12-08
Filing date: 2020-12-08
Publication date: 2021-09-07
Anticipated expiration: 2040-12-08
Also published as: TWI815179B; CN112405330A; TW202224850A; WO2022121428A1

Abstract

The invention discloses a polishing device which comprises a base, wherein the base is provided with a polishing head seat, the polishing head seat is provided with two polishing heads for fixing a wafer and a linear driving mechanism which is positioned between the two polishing heads and used for driving the two polishing heads to move. In the polishing process, the base is positioned above the polishing table, the polishing head drives the wafers to rotate, and the linear driving mechanism simultaneously drives the two wafers to linearly translate and sweep. The sweeping along the straight line can make the distribution of the polishing solution more uniform, and the abrasion of the polishing pad is more uniform, so that the polishing consistency of the two wafers can be obviously improved. The polishing of the wafers in the same batch is the same, so that the quality stability of the product is ensured, and the step of detecting the quality of the product in the subsequent treatment process is simplified.

Description

Polishing device

Technical Field

The invention relates to the technical field of semiconductor processing equipment, in particular to a polishing device.

Background

In the production process of the wafer, chemical planarization and polishing treatment is required to ensure that the surface of the wafer reaches qualified flatness and smoothness. In the chemical planarization polishing process, the final flatness and finish of the wafer are affected by the polishing pad, the polishing head, the polishing liquid, the polishing pad dresser, the motion track, the acting force and the like. How to ensure the quality and yield of polished wafers simultaneously is one of the main research directions in the wafer processing field.

The existing mainstream wafer polishing device comprises a polishing table and a polishing head corresponding to the polishing table, wherein the polishing table has one degree of freedom of autorotation, the polishing head has two degrees of freedom (autorotation and sweeping and swinging on the polishing head table), and the three degrees of freedom simultaneously act to realize polishing operation. The polishing pad on the surface of the polishing head can be fully and uniformly consumed by the action of sweeping and swinging the polishing head on the polishing head; meanwhile, the sweeping and swinging action of the polishing head can transfer the wafer from the polishing head to other transfer platforms such as a slide holder and the like.

However, in the conventional wafer polishing apparatus, although one polishing head corresponds to two polishing heads, the polishing efficiency can be improved, but it is difficult to ensure the consistency of the polishing process of two or more wafers, and the apparatus can only be applied to industries with low requirements on polishing precision.

Therefore, how to improve the polishing uniformity while ensuring the polishing efficiency is a technical problem that needs to be solved by those skilled in the art.

Disclosure of Invention

The invention aims to provide a polishing device, which drives two polishing heads to symmetrically move through a linear driving assembly, so that the consistency of wafers on the two polishing heads is obviously improved.

In order to achieve the above purpose, the present invention provides a polishing apparatus, which includes a base, wherein the base is provided with two polishing head bases, each polishing head base is provided with a polishing head for fixing a wafer and a linear driving mechanism for driving the polishing head to linearly move, the polishing apparatus further includes a bottom plate, the bottom plate is provided with a curved sliding rail, and the base is provided with a slider connected with the curved sliding rail.

Preferably, the base is provided with a linear slide rail for limiting a moving path of the polishing head bases, the linear driving mechanism drives the polishing head bases to linearly move along the linear slide rail, each polishing head base is provided with one polishing head, moving tracks of the two polishing head bases are symmetrically distributed, and a symmetry axis is a perpendicular bisector of a line segment formed by midpoints of the two polishing heads.

Preferably, the linear driving mechanism includes a lead screw connected to the polishing head and a driving portion for driving the lead screw to rotate.

Preferably, the number of the linear slide rails corresponding to a single polishing head seat is two, and the two linear slide rails corresponding to the same polishing head seat are arranged in parallel.

Preferably, a curve driving mechanism for driving the base to move on a curve slide rail is further arranged between the base and the bottom plate.

Preferably, the polishing device further comprises a polishing table located below the base, a liquid supply arm used for outputting polishing liquid to a position between the polishing head and the polishing table is arranged on the polishing table, and the layout position of the liquid supply arm is symmetrical with respect to the center of the middle point of the polishing table.

Preferably, the curve driving mechanism comprises a curve magnetic track which is arranged on the bottom plate and is concentric with the curve sliding rail, and a curve direct drive motor which is arranged in the base and is matched with the curve magnetic track.

Preferably, the curved slide rail is arc-shaped or annular, at least one polishing table and a wafer carrying table for carrying finished wafers are arranged below the curved slide rail, and the polishing table and the wafer carrying table are both located in a range covered by the projection of the curved slide rail on a horizontal plane.

Preferably, the curved slide rail is arc-shaped or annular, at least two polishing tables and a wafer carrying table for carrying finished wafers are arranged below the curved slide rail, all the polishing tables are located within a range covered by the projection of the curved slide rail on the horizontal plane, and the wafer carrying table is located outside the range covered by the projection of the curved slide rail on the horizontal plane.

Preferably, at least 2 bases are connected to the curved slide rail.

The precision requirement of wafer polishing is extremely high, and the motion track of the polishing process, the flow direction of the polishing solution and other factors can influence the polishing result.

The polishing device provided by the invention comprises a base, wherein the base is provided with a polishing head seat, the polishing head seat is provided with two polishing heads for fixing a wafer and a linear driving mechanism which is positioned between the two polishing heads and used for driving the two polishing heads to move, the polishing device also comprises a bottom plate, the bottom plate is provided with a curved slide rail, and the base is provided with a slide block connected with the curved slide rail.

In the polishing process, the base is positioned above the polishing table, the polishing head drives the wafers to rotate, the linear driving mechanism simultaneously drives the two wafers to linearly translate and sweep, and the polished wafers are moved away along the curved slide rail. The sweeping along the straight line can make the distribution of the polishing solution more uniform, and the abrasion of the polishing pad is more uniform, so that the polishing consistency of the two wafers can be obviously improved. The polishing of the wafers in the same batch is the same, so that the quality stability of the product is ensured, and the step of detecting the quality of the product in the subsequent treatment process is simplified.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

FIG. 1 is a schematic view of a structure in a polishing apparatus provided by the present invention;

FIG. 2 is a side view of the polishing apparatus of FIG. 1;

FIG. 3 is a schematic view of a curved slide rail and a curved driving mechanism;

FIG. 4 is a schematic diagram of a polishing apparatus of an embodiment at a first station;

FIG. 5 is a schematic diagram of a polishing apparatus of an embodiment at a second station;

fig. 6 is a schematic structural view of a polishing apparatus according to another embodiment.

Wherein the reference numerals in fig. 1 to 6 are:

the polishing device comprises a polishing assembly 100, a base 101, a curved slide rail 102, a slide block 103, a polishing head seat 104, a linear slide rail 105, a polishing head 200, a polishing table 201, a curved track 202, a curved direct drive motor 203, a lead screw 204, a bottom plate 300, a trimmer 301, a trimming disc 302, a liquid supply arm 303 and a slide holder 304.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In order that those skilled in the art will better understand the disclosure, the invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

Referring to fig. 1 to 6, fig. 1 is a schematic structural diagram of a polishing apparatus according to the present invention; FIG. 2 is a side view of the polishing apparatus of FIG. 1; FIG. 3 is a schematic view of a curved slide rail and a curved driving mechanism; FIG. 4 is a schematic diagram of a polishing apparatus of an embodiment at a first station; FIG. 5 is a schematic diagram of a polishing apparatus of an embodiment at a second station; fig. 6 is a schematic structural view of a polishing apparatus according to another embodiment.

The polishing apparatus provided by the present invention, having the structure shown in fig. 1, includes a base 101 and a polishing assembly 100. The base 101 is located above the polishing table 201, a polishing pad is arranged on the upper end face of the polishing table 201, the lower end face of the base 101 faces the polishing table 201, the lower end face of the base 101 is provided with the polishing assembly 100, the polishing assembly 100 comprises two polishing head bases 104, a linear driving mechanism and two polishing heads 200, and the linear driving mechanism and the two polishing head bases 104 are arranged on the lower end face of the base. Both the polishing head bases 104 are movably connected to the base 101, and the linear driving mechanism is connected to both the polishing head bases 104, so that the polishing head bases 104 are driven by the linear driving mechanism to move linearly. The two polishing heads 200 each fix a wafer, and the two polishing head bases 104 are connected to the two polishing heads 200, respectively, so that the polishing heads 200 are driven to move synchronously during the linear movement of the polishing head bases 104.

During polishing, the polishing head base 104 is positioned above the polishing table 201. The polishing head 200 is capable of spinning and rotating the wafer. The wafer fixed by the polishing head 200 is attached to the polishing pad, and is driven by the polishing head 200 to rotate and rub against the polishing pad, so as to polish the wafer. The linear driving mechanism drives the two polishing heads 200 to move linearly through the polishing head base 104.

Optionally, the movement tracks of the two polishing heads 200 are distributed axisymmetrically, and the symmetry axis is a perpendicular bisector of a line segment formed by connecting midpoints of the two polishing heads 200 in the same polishing assembly 100. The wafer is driven by the polishing head 200 to rotate relative to the polishing pad and simultaneously translate, so that the polishing effect is improved. In addition, the polishing head 200 and the linear driving mechanism are both connected to a control device mechanism, and the control mechanism can control the wafers fixed by the two polishing heads 200 to be polished along symmetrical tracks, so that the two wafers have higher consistency. The polishing head 200 may be constructed in accordance with the prior art, and one or more bases 101 may be provided in the polishing apparatus. One or two sets of polishing assemblies 100 may be provided per lower end surface of the base 101. The linear driving mechanism may be a cylinder, an oil cylinder, a connecting rod slider, a lead screw, or the like, and is not limited herein. The control mechanism can refer to a controller of a polishing device in the prior art, and is not described in detail herein.

In this embodiment, the polishing apparatus drives the two polishing heads 200 to perform translational motion along a straight line through the linear driving mechanism, and the two polishing heads 200 respectively drive one wafer to rotate. The polishing tracks of the wafers in the two polishing heads 200 are symmetrical, so that the polishing effect of the two wafers is almost the same, and the consistency of the wafers is improved.

Optionally, the polishing head base 104 is provided with a linear slide rail 105, the upper end surface of the polishing head 200 is provided with a slide groove matched with the linear slide rail 105, and the slide groove slides along the linear slide rail 105 to realize the movable connection between the polishing head 200 and the base 101. The two bases 101 move along the linear slide rail 105 under the driving of the linear driving mechanism, and the moving tracks of the two bases are symmetrical about a preset vertical line of the linear slide rail. The preset perpendicular line is generally a perpendicular bisector of the linear slide rail, and of course, the user may select other perpendicular lines other than the perpendicular bisector according to the requirement, which is not limited herein.

Optionally, the driving mechanism includes a lead screw 204 and a driving portion. Wherein, both ends of the screw 204 are respectively connected to the two polishing head bases 104, both ends of the screw 204 are provided with screws, and the directions of the screws at both ends are opposite. The driving part is in transmission connection with the middle part of the screw 204 and drives the screw 204 to rotate. Specifically, the driving portion is a driving motor, and the driving motor and the lead screw 204 are driven by a gear or a synchronous belt. The screw 204 rotates and exerts an axial force on the two polishing heads 200 to drive the two polishing heads 200 to move symmetrically. When the polishing head base 104 is located above the polishing table 201, the midpoint of the lead screw 204 coincides with the projection of the midpoint of the polishing table 201 in the horizontal direction.

In addition, the lead screw 204 is parallel to the linear slide 105, and the polishing head 200 is driven by the lead screw 204 to move along the linear slide 105. Two linear slide rails 105 are provided on the polishing head base 104. The ends of the two linear slides 105 are flush and parallel to each other. In one embodiment of the present application, the driving portion is disposed between the two polishing head bases 104, and for the convenience of installing the driving portion, the middle portions of the two linear sliding rails 105 are provided with a yielding notch, and the two polishing head bases 104 are disposed at two sides of the yielding notch. Of course, the user may also set one linear slide rail 105 on the base 100 as required, or may set two linear slide rails 105 on the lower end surface of the base 100 for each polishing head base 104, which is not limited herein.

Optionally, a liquid supply arm 303 is disposed on the polishing platen 201, and the liquid supply arm 303 is configured to output polishing liquid between the wafer and the polishing pad. As shown in fig. 4, the liquid supply arm 303 is two in number and is symmetrical with respect to the center point of the polishing table 201. That is, during polishing, the two liquid supply arms 303 are symmetrical about the center of the middle point of the lead screw 204, the outlets of the two liquid supply arms 303 respectively face one polishing head 200, and the polishing liquid is directly sprayed between the wafer and the polishing pad to play the roles of heat dissipation and washing. In addition, the outlets of both feed arms 303 may be positioned on a normal line passing through the midpoint of the lead screw 204.

Optionally, two polishing conditioners 301 are further disposed on the polishing table 201, and the two polishing conditioners 301 are also symmetric about the center of the middle point of the polishing table 201. The polishing dresser 301 is in the shape of a rod, one end of which is fixedly disposed, and the other end of which is rotatably connected to the dressing disk via a spindle, so as to dress the polishing layer on the upper surface of the polishing head 200 along an arc track.

Optionally, the bottom plate 300 is provided with a curved sliding rail 102, the base 101 is provided with a slider 103 connected to the curved sliding rail 102, a curved driving mechanism is further provided between the base 101 and the bottom plate 300, and the base 101 moves along the curved sliding rail 102 under the driving of the curved driving mechanism. The curved slide rail 102 is located above the polishing table 201, the base moves the polishing head 200 above the polishing table 201, and the polishing head 200 cooperates with the polishing table 201 to perform a polishing operation. The number of the bases 101 and the polishing tables 201 may be set according to the user's needs, and for example, the polishing apparatus may be provided with 1 base 101 which performs polishing work in cooperation with 1 or more polishing tables 201. The polishing apparatus may further include more than 2 bases 101, each base 101 corresponds to 1 polishing table 201, and the wafer held on the base 101 is polished on the corresponding polishing table 201. The polishing apparatus may further include 2 or more bases 101, the polishing tables 201 are divided into a plurality of groups according to polishing accuracy, all polishing tables 201 required for polishing a wafer are grouped, the polishing apparatus may further include 1 or more groups of polishing tables 201, and the number of groups of polishing tables 201 is usually not more than the number of bases 101.

Optionally, a wafer carrier 304 may be further disposed below the curved slide rail 102, and when the wafer is polished, the curved driving mechanism drives the base 101 to move above the wafer carrier 304, and the polishing head 200 places the wafer on the wafer carrier 304. The two stages 304 are typically arranged in the same manner as the polishing heads 200, and the two polishing heads 200 are exactly aligned with the two stages 304 when the pedestal 101 moves above the stage 304, so that the stage 304 is located in the projection of the curved slide rail 102. Of course, the wafer may be moved onto the slide stage by a mechanism such as a robot without disposing the slide stage below the user curved slide 102.

Optionally, the number of the curved sliding rails 102 may be two, the two curved sliding rails 102 are two concentric arcs or two concentric circles, and two sliding blocks 103 are respectively disposed on the inner side and the outer side of the base 101 and are used for respectively matching with the two curved sliding rails 102. The two curved sliding rails 102 can make the force applied to the inner side and the outer side of the base 101 more uniform, and a user can also use one curved sliding rail 102 according to the requirement, which is not limited herein.

Optionally, the curvilinear drive mechanism comprises a curvilinear magnetic track 202 and a curvilinear direct drive motor 203. The curvilinear magnetic track 202 is arranged on the bottom plate 300 and is concentric with the curvilinear slide 102, and the curvilinear direct drive motor 203 is arranged in the base 101. The curved direct drive motor 203 is matched with the curved magnetic track 202 to generate power, so that the base 101 can move along the curved slide rail 102.

In one embodiment of the present application, as shown in fig. 4, the curved slide rail 102 is semicircular, a base 101 is disposed in the curved slide rail 102, one end of the curved slide rail 102 is located above the stage 304, and the other end is located above the polishing stage 201. During the polishing process, the base 101 first moves to above the polishing table 201 to polish the wafer, and as shown in fig. 4, the position of the base 101 above the polishing table 201 is the first station. After polishing, the base 101 moves to above the stage 304, and places the wafer on the stage 304 and takes a new wafer, and as shown in fig. 5, the position of the base 101 above the stage 304 is the second station. When the base 101 moves from the first station to the second station, the liquid supply arm 303 and the dresser 301 rotate and move out of the upper part of the polishing table 201 to avoid the curvilinear motion of the polishing device. Of course, other distribution of the base 101 and the polishing stations 201 may be adopted by the user, for example, two polishing stations 201 may be disposed below the curved slide rail 102, and the polishing precision of the two polishing stations is different. The base 101 moves between the two polishing stations 201, and the wafer after polishing is moved by the robot to the stage.

In another embodiment of the present application, the curved sliding rail 102 is ring-shaped, and at least two bases 101 are disposed in the curved sliding rail 102. In the embodiment of fig. 6, 3 polishing tables 201A, 201B, 201C and two slide carriers 304 are disposed below the curved slide rail 102, and the two slide carriers 304 are uniformly distributed with the 3 polishing tables 201A, 201B, 201C as a group along the circumferential direction, and the distribution position is substantially square. Accordingly, 1

dresser

301A, 301B, 301C and one liquid supply arm 303A, 303B, 303C are provided for each of the 3 polishing tables 201A, 201B, 201C. The curved slide rail 102 is provided with 4 bases 101, and the 4 bases 101 correspond to 3 polishing tables 201A, 201B, 201C and a group of slide carriers 304 respectively. Each base 101 is provided with a set of polishing

assemblies

100A, 100B, 100C, 100D, all the bases 101 are rotated clockwise or counterclockwise along the curved slide rail 102, and the polishing pads on the 3 polishing tables 201A, 201B, 201C are gradually improved in accuracy along the rotation direction of the base 101. Thus, the susceptor 101 is transferred to the polishing station for finer grinding, and the wafer finally polished is moved to the two stages 304. In the polishing process, the 3 bases 101 respectively polish wafers on the 3 polishing tables 201A, 201B, 201C, and the other base 101 moves the polished wafer onto the wafer stage 304 and obtains a new wafer. Of course, the user may also set the number of the polishing tables 201, the slide stages 304 and the base 101 according to the requirement, for example, the combination of a plurality of polishing tables 201 such as 2, 4, 6, etc., and the combination of a plurality of slide stages 304 such as 2, 4, 6, etc. can meet the requirements of different production volumes and process flows, which is not limited herein.

The polishing apparatus of the present embodiment is provided with a plurality of polishing tables 201 and a base 101, and divides the polishing process into a plurality of processes. Several polishing processes are performed simultaneously, so that the polishing efficiency is improved, and the wafer yield is further improved.

It is noted that, in this specification, relational terms such as first and second, and the like are used solely to distinguish one entity from another entity without necessarily requiring or implying any actual such relationship or order between such entities.

The polishing apparatus provided by the present invention is described above in detail. The principles and embodiments of the present invention are explained herein using specific examples, which are presented only to assist in understanding the method and its core concepts. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.

Claims

1. A polishing device is characterized by comprising a base (101), wherein the base (101) is provided with two polishing head bases (104), the polishing head bases (104) are provided with polishing heads (200) used for fixing wafers and linear driving mechanisms used for driving the polishing heads (200) to linearly move, the polishing device also comprises a bottom plate (300), the bottom plate (300) is provided with a curve slide rail (102), and the base (101) is provided with a slide block (103) connected with the curve slide rail (102);

the polishing head base comprises a base (101), wherein the base (101) is provided with a linear sliding rail (105) used for limiting the moving path of the polishing head base (104), the linear driving mechanism drives the polishing head base (104) to linearly move along the linear sliding rail (105), the moving directions of the polishing head base (104) are opposite, each polishing head base (104) is provided with one polishing head (200), the moving tracks of the polishing head bases (104) are symmetrically distributed, and the symmetry axis is a perpendicular bisector of a line segment formed by the middle points of the polishing heads (200).

2. The polishing apparatus as set forth in claim 1, wherein the linear driving mechanism comprises a lead screw (204) connected to the polishing head (200) and a driving portion for rotating the lead screw (204).

3. The polishing apparatus according to claim 1, wherein the linear slide rails (105) corresponding to a single polishing head seat (104) are two, and the two linear slide rails (105) corresponding to the same polishing head seat (104) are arranged in parallel.

4. A polishing apparatus according to claim 2, wherein a curved driving mechanism for driving the base (101) to move on the curved slide rail (102) is further provided between the base (101) and the bottom plate (300).

5. The polishing apparatus according to claim 4, further comprising a polishing table (201) located below the base (101), wherein a liquid supply arm (303) for supplying polishing liquid to a space between the polishing head (200) and the polishing table (201) is provided on the polishing table (201), and a layout position of the liquid supply arm (303) is symmetrical with respect to a midpoint center of the polishing table (201).

6. The polishing apparatus according to claim 4, wherein the curved driving mechanism comprises a curved track (202) provided on the base plate (300) and concentric with the curved slide rail (102), and a curved direct drive motor (203) provided in the base (101) and cooperating with the curved track (202).

7. The polishing device according to claim 5, wherein the curved slide rail (102) is circular arc-shaped or annular, at least one polishing table (201) and a wafer carrier table (304) for carrying finished wafers are arranged below the curved slide rail (102), and the polishing table (201) and the wafer carrier table (304) are both located within a range covered by a projection of the curved slide rail (102) in a horizontal plane.

8. The polishing device according to claim 5, wherein the curved slide rail (102) is arc-shaped or annular, at least two polishing tables (201) and a wafer carrier (304) for carrying finished wafers are arranged below the curved slide rail (102), all the polishing tables (201) are located within a range covered by a projection of the curved slide rail (102) on a horizontal plane, and the wafer carrier (304) is located outside the range covered by the projection of the curved slide rail (102) on the horizontal plane.

9. A polishing device according to claim 3, characterized in that at least 2 of said bases (101) are connected to said curved slide (102).