CMP polishing machine for semiconductor wafer and polishing method

Abstract

The invention discloses a CMP polishing machine for a semiconductor wafer and a polishing method, and relates to the technical field of polishing tools for the outer surface of the semiconductor wafer. The CMP polishing machine comprises a machining cabinet, a protective cover is hinged to the rear end of the top of the machining cabinet, joint mechanical arms are installed on the two sides of the bottom of a rotary table of an electric rotary table, and a polishing mechanism is installed on a deflection base; a transmission mechanism is arranged in the transmission cover; a stirring assembly is arranged at the lower part of the transmission cover; an inner supporting mechanism is arranged in the lifting groove; through the cooperation of the joint mechanical arm, the deflection seat and the polishing mechanism, cylindrical semiconductor wafers with different sizes and outer surface inclination angles can be conveniently and rapidly polished, and the purpose of enlarging or changing a polished part in the polishing process can be achieved; and the efficiency of polishing the outer surface of the semiconductor wafer is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of outer surface polishing tools for semiconductor wafers, and particularly to a CMP polishing machine and a polishing method for semiconductor wafers. Background Art

[0002] Existing CMP polishing machines for semiconductor wafers are important and indispensable equipment in the semiconductor wafer processing industry. They are mainly used to remove burrs, rough edges and uneven parts on the surface of semiconductor wafers, so that the surface reaches a smooth and flat effect, thereby improving the quality and aesthetics of semiconductor wafers; through precise mechanical design and efficient grinding technology, fine processing of the surface of semiconductor wafers is achieved; and after some waste semiconductor wafers are recycled, in order to enable the waste semiconductor wafers to be reused, the semiconductor wafers need to be polished, so a CMP polishing machine is required; When existing CMP polishing machines are in use, generally an external positioning mechanism is used to clamp and fix the outer surface of the semiconductor wafer. However, when clamping a cylindrical semiconductor wafer from the outside, there is an occluded part after clamping, and the occluded part after clamping cannot be effectively polished, and it is necessary to stop the machine for transposition clamping to perform subsequent polishing operations. Moreover, when the existing polishing device polishes the outer surface of the semiconductor wafer, it cannot change the polishing area of the semiconductor wafer during the polishing process; and the polishing head in the polishing device is prone to generate high temperature during the polishing of the semiconductor wafer. If the polishing head is not cooled in time, the high temperature generated by the friction of the polishing head will burn the surface of the semiconductor wafer; Therefore, a CMP polishing machine and a polishing method for semiconductor wafers are proposed to solve the above problems. Summary of the Invention

[0003] The purpose of the present invention is to solve the disadvantages existing in the prior art, and to propose a CMP polishing machine and a polishing method for semiconductor wafers.

[0004] In order to achieve the above purpose, the present invention adopts the following technical solutions: A CMP polishing machine for semiconductor wafers includes a processing cabinet. The rear end of the top of the processing cabinet is movably hinged by a pin shaft with a protective cover. A baffle is rotatably provided at the lower part of the front opening of the protective cover. A rotating table is rotatably provided in an installation opening in the middle of the top surface of the processing cabinet. A slag collection annular groove is provided on the outer side of the upper part of the installation opening. A plurality of arc-shaped slag dropping openings are provided on the circumferential side of the bottom surface of the slag collection annular groove. A splash-proof cover is provided on the top of the processing cabinet outside the slag collection annular groove; An installation beam is horizontally fixed on the upper part of the protective cover. An electric turntable is provided at the bottom of the installation beam. A transverse movement component for the horizontal movement of the electric turntable is provided inside the installation beam; Joint mechanical arms are installed on both sides of the bottom of the rotating table of the electric turntable, and deflection seats are installed at the bottom ends of the joint mechanical arms, and polishing mechanisms are installed on the deflection seats; a self-locking motor for deflection operation of the deflection seat is provided at the bottom of the rear end of the joint mechanical arm; A transmission cover is provided on the inner top surface of the processing cabinet, and a transmission mechanism for driving a turntable is provided inside the transmission cover; a collecting box is provided at the lower part of the processing cabinet, and a stirring assembly for preventing sedimentation inside the collecting box is provided at the lower part of the transmission cover; a lifting groove is vertically opened in the middle of the top surface of the turntable, and an internal support mechanism for supporting semiconductor wafers is vertically provided inside the lifting groove.

[0005] Preferably, the transmission mechanism includes a rotating gear ring fixed to the bottom of the rotating table, a fixed plate arranged on the inner wall of one side of the transmission cover, a servo motor arranged at the top outer end of the fixed plate, a driving gear arranged at the top of the servo motor, a rotating shaft rotatably arranged at the top inner end of the fixed plate and a driven gear arranged at the top of the rotating shaft, the driving gear is meshed with the teeth of the outer ring of the rotating gear ring for transmission, and the driven gear is meshed with the teeth of the inner ring of the rotating gear ring for transmission; a spline sleeve is rotatably provided in the middle part of the bottom surface of the rotating table, and a driven gear meshed with the driven gear is fixedly sleeved on the top outer surface of the spline sleeve.

[0006] Preferably, the stirring assembly includes a stirring shaft rotatably arranged at the bottom of the transmission cover and a stirring blade fixedly connected to the bottom end of the stirring shaft. The stirring blade is in the shape of a twisted inclined plate. The top end of the stirring shaft movably penetrates into the interior of the transmission cover and is coaxially fixed with a spline shaft, which is inserted into the interior of the spline sleeve shaft.

[0007] Preferably, a plurality of cleaning strips extending into the slag collecting ring groove are equidistantly fixed to the circumferential side of the outer ring wall at the upper part of the rotating table, and the bottom of the cleaning strips is in close contact with the inner bottom surface of the slag collecting ring groove; the front end lower part of the two side walls of the protective cover are rotatably provided with lock buckles, and the front end of the two side faces of the processing cabinet are fixed with buckles to cooperate with the lock buckles.

[0008] Preferably, the transverse movement assembly includes a transverse movement groove opened at the bottom of the mounting beam, a screw that rotates laterally inside the transverse movement groove, and a movable seat sleeved on the screw. The electric turntable is installed at the bottom of the movable seat, and a driving motor for driving the screw is provided on one side of the protective cover.

[0009] Preferably, the polishing mechanism includes a sliding groove opened on the inner side surface of the deflection seat, a movable plate slidably arranged inside the sliding groove, a polishing head fixedly connected to the outer end surface of the movable plate, a transmission groove opened in the middle of the sliding groove and a pushing assembly arranged at both ends of the transmission groove, a cooling chamber is opened inside the movable plate, and a liquid-permeable cotton plate is arranged inside the cooling chamber.

[0010] Preferably, a shunt pipe is bent upward inside the cooling chamber, the outer end of the shunt pipe passes through the transmission groove, and a conduit groove connected to the transmission groove is opened inside the deflection seat, an injection pipe is passed through the conduit groove, and the inner end of the injection pipe is fixedly connected to the outer end of the shunt pipe.

[0011] Preferably, the driving component includes a rotating rod drivingly arranged at both ends inside the transmission groove and a transmission gear fixedly sleeved on the rotating rod. Servo motors for driving the rotating rod are arranged at both the upper and lower ends of the rear end face of the deflection seat, and a rack plate meshing with the transmission gear is fixedly connected to the inner side surface of the moving plate.

[0012] Preferably, the inner support mechanism includes a lifting column vertically arranged inside the lifting groove, three storage grooves opened on the circumferential side of the outer side surface of the lifting column, an inner support plate movably hinged inside the storage groove, a screw rod vertically rotatably arranged inside the storage groove, and a micro motor installed at the bottom end of the screw rod. The bottom end of the inner support plate is hinged to the inner bottom of the storage groove through a pin shaft; an installation notch is vertically opened on the bottom end face of the lifting column, an electric push cylinder is vertically arranged inside the installation notch, and the bottom end of the electric push cylinder is fixedly connected to the inner bottom surface of the lifting groove; a threaded sleeve is sleeved on the lower part of the screw rod, an inner support rod is hinged to the threaded sleeve, a hinge seat is fixedly connected to the upper end of the inner side surface of the inner support plate, the top end of the inner support rod is movably hinged to the hinge seat, three anti-rotation bars are vertically arranged on the circumferential side of the inner wall of the lifting groove, and three anti-rotation bar grooves are opened on the outer surface of the lifting column to cooperate with the anti-rotation bars; a rubber anti-slip pad is arranged on the outer end face of the inner support plate.

[0013] A usage method of a CMP polishing machine for semiconductor wafers includes the following steps: S1: First, electrically connect the electric turntable, the articulated robotic arm, the servo motor, the electric push cylinder, the micro motor, the servo motor, and the driving motor to an external control device through wires respectively. Then, invert the semiconductor wafer to be polished on the top of the rotating table. The anti-slip convex strips on the top of the rotating table play a role of limiting and abutting against the semiconductor wafer to be polished. Connect the outer end of the liquid injection pipe to an external liquid supply device for supplying CMP polishing liquid, and the amount of CMP polishing liquid transported can be controlled to reduce the utilization amount of CMP polishing liquid per unit wafer. S2: Then, start the electric push cylinder to push the lifting column out of the lifting groove. The lifted lifting column will extend into the tank body through the bottom opening of the semiconductor wafer. Then, start the micro motor to drive the screw rod to rotate. By the rotating screw rod, the threaded sleeve can be pushed to expand the inner support rod outwards. Through the outward expansion of the inner support, the top end of the inner support plate can be pushed to expand outwards, and then the inner support plate abuts against the inner wall of the semiconductor wafer. Furthermore, the unfolded inner support plate plays a role of inner support fixation and downward pressing and locking for the semiconductor wafer to be polished. S3: After positioning the semiconductor wafer to be polished, start the driving motor to drive the lead screw to rotate at this time. Through the rotation of the lead screw, the moving seat can be adjusted horizontally at the bottom of the installation beam. The moving seat sleeved by the position movement can drive the electric turntable to move horizontally, so as to facilitate moving the electric turntable directly above the semiconductor wafer. Then, start the articulated robotic arm to drive the two deflection seats to descend initially, and then start the self-locking motor at the bottom of the articulated robotic arm to drive the deflection seat to perform an angle deflection operation, so that the deflection seat can be deflected and adjusted according to the shape of the semiconductor wafer, and the deflection seat can be adjusted to be inclined at the same inclination as the shape of the semiconductor wafer, so that the polishing head can have the same inclination as the outer surface of the semiconductor wafer. Then, start the articulated robotic arm to drive the deflection seat to move, so that the polishing head installed on the deflection seat can be in contact with the outer surface of the semiconductor wafer; S4: Then, start the servo motor to drive the driving gear. Through the meshing of the driving gear and the rotating gear ring, the rotating table can be driven to rotate. Through the rotation of the rotating table, the placed semiconductor wafer can be driven to rotate. When the semiconductor wafer rotates, the polishing head on the deflection seat can polish the outer surface of the rotating semiconductor wafer; when it is necessary to adjust the height of the polishing head during the polishing process according to the height of the semiconductor wafer, start the servo motor to drive the transmission gear to rotate. Through the rotation of the transmission gear, the moving plate installed with the rack plate can be driven to slide up and down in the transmission groove of the deflection seat, so as to change the position of the polishing head on the deflection seat, which is convenient to meet the polishing operations of semiconductor wafers with different height dimensions and improve the application range of this device; and it can also make the polishing head move along the inclined outer surface of the semiconductor wafer during the polishing process; thus, the polishing area of the semiconductor wafer can be increased; S5: When the rotating table rotates, the semiconductor wafer is in a polishing state at this time. And to prevent the polishing head from overheating and drying, the external liquid supply device, the liquid injection pipe and the shunt pipe inject liquid into the cooling cavity, and the liquid injection operation is carried out from the upper part to the lower part of the cooling cavity. And the liquid can be fully dispersed by the liquid permeable cotton board inside the cooling cavity. Then, the water is permeated to the polishing head through the liquid permeable cotton board, so that the polishing head is kept in a wet state, thus avoiding a large amount of flying dust when polishing the semiconductor wafer; moreover, the dust polished from the semiconductor wafer will fall into the slag collection ring groove. The rotating table drives the cleaning strip to clean the waste slag falling into the slag collection ring groove into the slag falling port, and the waste slag falls into the collection box through the slag falling port; S6: Drive the driven gear to rotate by rotating the teeth of the inner ring of the toothed ring; through the meshing of the driven gear and the passive gear, drive the spline sleeve shaft to rotate, drive the stirring shaft provided with a spline shaft to rotate through the rotating spline sleeve shaft, and drive the stirring blades to stir the waste residue inside the collection box through the rotating stirring shaft, so as to prevent the waste residue mixed with liquid from precipitating inside the collection box.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: Through the cooperation of the articulated robotic arm with the deflection seat and the polishing mechanism, it is convenient to quickly polish cylindrical semiconductor wafers with different sizes and outer surface inclination angles, and it can achieve the purpose of increasing or changing the polishing part during the polishing process, which is convenient to further improve the efficiency of the outer surface polishing of semiconductor wafers; and it can make the deflection seat perform angle deflection operations, so that the deflection seat can be adjusted to be inclined to the inclination of the semiconductor wafer's outer shape, and then the inclination of the polishing head can be the same as that of the outer surface of the semiconductor wafer, which is convenient for the polishing head installed on the deflection seat to be in close contact with the outer surface of the semiconductor wafer; improve the adaptability adjustment during the polishing of semiconductor wafers; at the same time, it is also convenient to meet the polishing operations of semiconductor wafers with different height dimensions, and improve the application range of the device; and it can also make the polishing head move along the inclined outer surface of the semiconductor wafer during the polishing process; thus, it can increase the polishing area of the semiconductor wafer; Through the cooperation of the inner support mechanism and the rotating table, the present invention facilitates the expanded inner support plate to abut against the inner wall of the semiconductor wafer, which is convenient for inner support fixation and downward pressing and locking of the semiconductor wafer to be polished, and can also automatically align the semiconductor wafer placed on the top of the rotating table, effectively improving the convenience of automatic positioning and automatic centering of the semiconductor wafer before polishing. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The drawings described herein are used to provide a further understanding of the present invention, form a part of this application, and the schematic embodiments of the present invention and their descriptions are used to explain the present invention, and do not constitute an improper limitation to the present invention. In the drawings: Figure 1 It is a schematic structural diagram of the whole of the present invention from the first perspective; Figure 2 It is a schematic structural diagram of the whole of the present invention from the second perspective; Figure 3 It is a schematic structural diagram of the processing cabinet and the protective cover of the present invention; Figure 4 It is a schematic structural diagram of the inside of the processing cabinet of the present invention; Figure 5 It is a schematic structural diagram of the top of the processing cabinet of the present invention; Figure 6Schematic diagram of the collection box, splash guard and upper joint robotic arm of the present invention; Figure 7 Schematic diagram of the bottom structure of the processing countertop of the present invention; Figure 8 Schematic diagram of the internal structure of the transmission cover of the present invention; Figure 9 Schematic diagram of the robotic arm joint, deflection seat and turntable of the present invention; Figure 10 Schematic diagram of the transmission mechanism of the present invention; Figure 11 Schematic diagram of the turntable and lifting column of the present invention; Figure 12 Schematic diagram of the lower part of the transmission cover of the present invention; Figure 13 Schematic diagram of the turntable, transmission mechanism and stirring shaft of the present invention; Figure 14 Schematic diagram of the drive gear, driven gear and spline sleeve shaft of the present invention; Figure 15 Schematic diagram of the transverse movement assembly and robotic arm joint of the present invention; Figure 16 Front view structural cross-section of the deflection seat of the present invention; Figure 17 First perspective schematic diagram of the deflection seat, moving plate and polishing head of the present invention; Figure 18 Second perspective schematic diagram of the deflection seat, moving plate and polishing head of the present invention; Figure 19 Schematic diagram of the moving plate, polishing head and pushing assembly of the present invention; Figure 20 Schematic diagram of the internal support mechanism of the present invention; Figure 21 Schematic diagram of the internal support rod, micro motor and internal support plate of the present invention.

[0016] Sequence numbers in the figure: 1, processing cabinet; 2, protective cover; 3, baffle; 4, splash guard; 5, rotating table; 6, electric turntable; 7, articulated robotic arm; 8, deflection seat; 9, lead screw; 10, moving seat; 11, lock; 12, drive cover; 13, collection box; 14, stirring shaft; 15, stirring blade; 16, cleaning strip; 17, rotating gear ring; 18, servo motor; 19, drive gear; 20, driven gear; 21, spline sleeve shaft; 22, passive gear; 23, spline shaft; 24, lifting column; 25, inner support plate; 26, electric push cylinder; 27, screw; 28, hinge seat; 29, inner support rod; 30, micro motor; 31, moving plate; 32, polishing head; 33, rack plate; 34, drive gear; 35, servo motor; 36, liquid injection pipe; 37, shunt pipe. Detailed implementation mode

[0017] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0018] Embodiment 1: Refer to Figure 1 - Figure 21, a CMP polishing machine for semiconductor wafers, comprising a processing cabinet 1. The rear end of the top of the processing cabinet 1 is movably hinged with a protective cover 2 through a pin shaft. The upper part of one side wall of the protective cover 2 is provided with a controller. The lower part of the front end opening of the protective cover 2 is rotatably provided with a baffle 3. The middle part of the top surface of the processing cabinet 1 is provided with an installation opening. A rotating table 5 is rotatably provided in the installation opening. The top surface of the rotating table 5 is equidistantly provided with multiple circles of anti-slip convex strips. The upper outer side of the installation opening is provided with a slag collection ring groove. The bottom circumference of the slag collection ring groove is provided with a plurality of arc-shaped slag discharge openings. A splash-proof cover 4 is provided on the top of the processing cabinet 1 outside the slag collection ring groove; a mounting beam is horizontally fixed on the upper part of the protective cover 2. An electric turntable 6 is provided at the bottom of the mounting beam. A transverse movement assembly for the horizontal movement of the electric turntable 6 is provided inside the mounting beam; both sides of the bottom of the rotating table of the electric turntable 6 are installed with articulated robotic arms 7. The bottom ends of the articulated robotic arms 7 are both installed with deflection seats 8. A polishing mechanism is installed on the deflection seats 8; a self-locking motor for the deflection operation of the deflection seat 8 is provided at the bottom of the rear end of the articulated robotic arm 7; a transmission cover 12 is provided on the inner top surface of the processing cabinet 1. A transmission mechanism for driving the rotating table 5 is provided inside the transmission cover 12; a collection box 13 is provided at the lower part of the processing cabinet 1. An agitating assembly for preventing sedimentation inside the collection box 13 is provided at the lower part of the transmission cover 12; a lifting groove is vertically opened in the middle of the top surface of the rotating table 5. An inner support mechanism for inner supporting the semiconductor wafer is vertically provided inside the lifting groove; through the cooperation of the articulated robotic arm 7 with the deflection seat 8 and the polishing mechanism, it is convenient to perform rapid polishing operations on cylindrical semiconductor wafers of different sizes and outer surface inclination angles, and it is possible to increase or change the polishing part during the polishing process, which is convenient for further improving the efficiency of outer surface polishing of semiconductor wafers; and it is possible to perform an angle deflection operation on the deflection seat 8, so that the deflection seat 8 can be adjusted to be inclined to the inclination of the semiconductor wafer shape, and then the inclination of the polishing head 32 installed on the deflection seat 8 can be the same as the outer surface of the semiconductor wafer, which is convenient for the polishing head 32 installed on the deflection seat 8 to be in close contact with the outer surface of the semiconductor wafer; improve the adaptation adjustment during the polishing of semiconductor wafers; at the same time, it is also convenient to meet the polishing operations of semiconductor wafers of different height sizes, improve the application range of the device; and it is also possible to move the polishing head 32 along the inclined outer surface of the semiconductor wafer during the polishing process; thereby increasing the polishing area of the semiconductor wafer.

[0019] Embodiment 2: Basically the same as the technical solution of Embodiment 1, the difference is that, as Figures 7 to 10 , Figure 12 , Figure 13As shown in the figure, the transmission mechanism includes a rotating gear ring 17 fixed to the bottom of the rotating table 5, a fixed plate provided on the inner wall of one side of the transmission cover 12, a servo motor 18 provided at the outer end of the top of the fixed plate, a driving gear 19 provided on the top of the servo motor 18, a rotating shaft rotatably provided at the inner end of the top of the fixed plate, and a driven gear 20 provided at the top of the rotating shaft. The driving gear 19 is in meshing transmission with the teeth on the outer ring of the rotating gear ring 17, and the driven gear 20 is in meshing transmission with the teeth on the inner ring of the rotating gear ring 17. In the middle of the bottom surface of the rotating table 5, a spline sleeve shaft 21 is rotatably provided, and a driven gear 22 meshing with the driven gear 20 is fixedly sleeved on the outer surface of the top of the spline sleeve shaft 21.

[0020] In the present invention, the stirring assembly includes a stirring shaft 14 rotatably provided at the bottom of the transmission cover 12 and a stirring blade 15 fixedly connected to the bottom end of the stirring shaft 14. The stirring blade 15 is in the shape of a twisted inclined plate. The top end of the stirring shaft 14 movably penetrates into the interior of the transmission cover 12 and is coaxially fixedly connected with a spline shaft 23. The spline shaft 23 is inserted into the interior of the spline sleeve shaft 21. A plurality of cleaning strips 16 extending into the slag collection ring groove are equidistantly fixedly connected to the peripheral side of the outer wall of the upper part of the rotating table 5. The bottom of the cleaning strip 16 is in close contact with the inner bottom surface of the slag collection ring groove. Lock catches 11 are rotatably provided at the lower parts of the front ends of both side walls of the protective cover 2, and buckles are fixedly connected to both sides of the front end of the processing cabinet 1 in cooperation with the lock catches 11. After the connection between the lock catches 11 and the buckles is released, the protective cover 2 can be flipped backward to be opened, facilitating the exposure of the semiconductor wafer on the rotating table 5. The transverse movement assembly includes a transverse movement groove opened at the bottom of the installation beam, a lead screw 9 transversely rotatably provided in the transverse movement groove, and a moving seat 10 sleeved on the lead screw 9. The electric turntable 6 is installed at the bottom of the moving seat 10, and a driving motor for driving the lead screw 9 is provided on one side of the protective cover 2.

[0021] Embodiment 3: It is basically the same as the technical solution of Embodiment 1, except that, as Figures 15 to 21As shown in the figure, the polishing mechanism includes a sliding groove opened on the inner side surface of the deflection seat 8, a moving plate 31 slidably disposed inside the sliding groove, a polishing head 32 fixedly connected to the outer end surface of the moving plate 31, a transmission groove opened in the middle of the sliding groove, and a pushing assembly disposed at both ends inside the transmission groove. A cooling cavity is opened inside the moving plate 31, and a liquid-permeating cotton board is disposed inside the cooling cavity; a diversion pipe 37 is bent upward inside the cooling cavity, the outer end of the diversion pipe 37 penetrates into the transmission groove, and a conduit groove communicating with the transmission groove is opened inside the deflection seat 8. A liquid injection pipe 36 is disposed inside the conduit groove, and the inner end of the liquid injection pipe 36 is fixedly communicated with the outer end of the diversion pipe 37; through the cooperation of the articulated robotic arm 7 with the deflection seat 8 and the polishing mechanism, it is convenient to quickly polish cylindrical semiconductor wafers with different sizes and outer surface inclination angles, and it is possible to increase or change the polished part during the polishing process, which is convenient for further improving the efficiency of the outer surface polishing of the semiconductor wafer; and it is possible to perform an angle deflection operation on the deflection seat 8, so that the deflection seat 8 can be adjusted to be inclined to the inclination of the semiconductor wafer shape, and then the inclination of the polishing head 32 can be the same as the outer surface of the semiconductor wafer, which is convenient for the polishing head 32 installed on the deflection seat 8 to be in close contact with the outer surface of the semiconductor wafer; improve the adaptation adjustment during the polishing of the semiconductor wafer; the pushing assembly includes a rotating rod drivingly disposed at both ends inside the transmission groove and a transmission gear 34 fixedly sleeved on the rotating rod. Servo motors 35 for driving the rotating rod are disposed at the upper and lower ends of the rear end surface of the deflection seat 8, and a rack plate 33 meshing with the transmission gear 34 is fixedly connected to the inner side surface of the moving plate 31; through the setting of the pushing assembly, it is convenient to move the polishing head 32 along the inclined outer surface of the semiconductor wafer during the polishing process; thus, the polishing area of the semiconductor wafer can be increased.

[0022] In the present invention, the inner support mechanism includes a lifting column 24 vertically arranged inside the lifting groove, three storage grooves formed on the circumferential side of the outer surface of the lifting column 24, inner support plates 25 movably hinged inside the storage grooves, screw rods 27 vertically rotatably arranged inside the storage grooves, and a micro motor 30 installed at the bottom end of the screw rod 27. The bottom end of the inner support plate 25 is hinged to the bottom inside of the storage groove through a pin shaft; an installation notch is vertically formed on the bottom end surface of the lifting column 24, and an electric push cylinder 26 is vertically arranged inside the installation notch. The bottom end of the electric push cylinder 26 is fixedly connected to the inner bottom surface of the lifting groove; a threaded sleeve is sleeved on the lower part of the screw rod 27, an inner support rod 29 is hinged to the threaded sleeve, a hinge seat 28 is fixedly connected to the upper end of the inner side surface of the inner support plate 25, and the top end of the inner support rod 29 is movably hinged to the hinge seat 28; three anti-rotation bars are vertically arranged on the circumferential side of the inner wall of the lifting groove, and three anti-rotation bar grooves are formed on the outer surface of the lifting column 24 in cooperation with the anti-rotation bars; a rubber anti-slip pad is arranged on the outer end surface of the inner support plate 25; through the cooperation of the inner support mechanism and the rotating table 5, it is convenient to make the unfolded inner support plates 25 abut against the inner wall of the semiconductor wafer, which is convenient for inner support fixation and downward pressing and locking of the semiconductor wafer to be polished, and can play an automatic alignment role for the semiconductor wafer placed on the top of the rotating table 5, effectively improving the convenience of automatic positioning and automatic centering of the semiconductor wafer before polishing.

[0023] Working principle: In this embodiment, the present invention also proposes a usage method of a CMP polishing machine for semiconductor wafers, including the following steps: Step 1, first electrically connect the electric turntable 6, the articulated robotic arm 7, the servo motor 18, the electric push cylinder 26, the micro motor 30, the servo motor 35, and the drive motor to an external control device through wires respectively. Then, place the semiconductor wafer to be polished upside down on the top of the rotating table 5. The anti-slip convex strips on the top of the rotating table 5 play a role of limiting and abutting against the semiconductor wafer to be polished, and connect the outer end of the liquid injection pipe 36 to an external liquid supply device; Step 2, then start the electric push cylinder 26 to push the lifting column 24 out of the lifting groove. The lifted lifting column 24 will extend into the tank body from the bottom opening of the semiconductor wafer. Then start the micro motor 30 to drive the screw rod 27 to rotate. Through the rotation of the screw rod 27, the threaded sleeve can be made to push the inner support rod 29 to expand outwards. Through the outward expansion of the inner support rod 29, the top end of the inner support plate 25 can be pushed to expand outwards, so that the inner support plate 25 abuts against the inner wall of the semiconductor wafer. Furthermore, the unfolded inner support plates 25 play a role of inner support fixation and downward pressing and locking for the semiconductor wafer to be polished, and can play an automatic alignment role for the semiconductor wafer placed on the top of the rotating table 5, effectively improving the convenience of automatic positioning and automatic centering of the semiconductor wafer before polishing; Step 3: After positioning the semiconductor wafer to be polished, start the drive motor to drive the lead screw 9 to rotate. By the rotation of the lead screw 9, the moving seat 10 can be adjusted horizontally at the bottom of the installation beam. The moving seat 10 sleeved by position movement can drive the electric turntable 6 to move horizontally, facilitating the movement of the electric turntable 6 directly above the semiconductor wafer. Then, start the articulated robotic arm 7 to drive the two deflection seats 8 to descend initially, and then start the self-locking motor at the bottom of the articulated robotic arm 7 to drive the deflection seat 8 to perform an angle deflection operation, enabling the deflection seat 8 to be deflected and adjusted according to the shape of the semiconductor wafer, so that the deflection seat 8 can be adjusted to be inclined at the same inclination as the shape of the semiconductor wafer, and thus the polishing head 32 can have the same inclination as the outer surface of the semiconductor wafer. Then, start the articulated robotic arm 7 to drive the deflection seat 8 to move, so that the polishing head 32 installed on the deflection seat 8 can be in contact with the outer surface of the semiconductor wafer; Step 4: Then, start the servo motor 18 to drive the drive gear 19. Through the meshing of the drive gear 19 and the rotating gear ring 17, the rotating table 5 can be driven to rotate. By the rotation of the rotating table 5, the placed semiconductor wafer can be driven to rotate. When the semiconductor wafer rotates, the outer surface of the rotating semiconductor wafer can be polished by the polishing head 32 on the deflection seat 8; When it is necessary to adjust the height of the polishing head 32 during the polishing process according to the height of the semiconductor wafer, start the servo motor 35 to drive the transmission gear 34 to rotate. By the rotation of the transmission gear 34, the moving plate 31 installed with the rack plate 33 can be driven to slide up and down in the transmission groove of the deflection seat 8, thereby changing the position of the polishing head 32 on the deflection seat 8, facilitating the polishing operation of semiconductor wafers with different height dimensions, and improving the application range of this device; And it can also make the polishing head 32 move along the inclined outer surface of the semiconductor wafer during the polishing process; thus, the polishing area of the semiconductor wafer can be increased; Step 5: After the rotating table 5 rotates, the semiconductor wafer is in a polishing state at this time. And to prevent the polishing head 32 from overheating and drying, the external liquid supply device, the liquid injection pipe 36, and the shunt pipe 37 perform a liquid injection operation towards the inside of the cooling cavity, and the liquid injection operation is from the upper part to the lower part of the cooling cavity. And the water body can be fully dispersed by the liquid seepage cotton board inside the cooling cavity. Then, the water is permeated to the polishing head 32 through the liquid seepage cotton board, keeping the polishing head 32 in a wet state, and thus avoiding a large amount of flying dust during the polishing of the semiconductor wafer; Moreover, the dust polished from the semiconductor wafer will fall into the slag collection ring groove. The rotating rotating table 5 drives the cleaning strip 16 to sweep the waste slag falling into the slag collection ring groove into the slag outlet, and the waste slag falls into the collection box 13 through the slag outlet; Step 6: Drive the driven gear 20 to rotate by rotating the teeth on the inner ring of the gear ring 17; due to the meshing of the driven gear 20 with the passive gear 22, the spline sleeve shaft 21 will be driven to rotate, and the stirring shaft 14 provided with a spline shaft 23 will be driven to rotate by the rotating spline sleeve shaft 21. The rotating stirring shaft 14 will drive the stirring blades 15 to stir the waste residue inside the collection box 13, preventing the waste residue mixed with the liquid from precipitating inside the collection box 13.

[0024] The above is only a preferred specific implementation of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. A CMP polishing machine for semiconductor wafers, comprising a processing cabinet, characterized in that: The rear end of the top of the processing cabinet is movably hinged with a protective cover through a pin shaft. A baffle is rotatably arranged at the lower part of the front opening of the protective cover. An installation opening is formed in the middle of the top surface of the processing cabinet. A rotating table is rotatably arranged in the installation opening. A slag collecting ring groove is formed on the outer side of the upper part of the installation opening. A plurality of arc-shaped slag dropping openings are formed on the circumferential side of the bottom surface of the slag collecting ring groove. A splash-proof cover is arranged on the top of the processing cabinet outside the slag collecting ring groove; A mounting beam is horizontally fixed on the upper part of the protective cover. An electric turntable is arranged at the bottom of the mounting beam. A transverse movement assembly for the horizontal movement of the electric turntable is arranged inside the mounting beam; Jointed robotic arms are installed on both sides of the bottom of the rotating table of the electric turntable. Deflection seats are installed at the bottom ends of the jointed robotic arms. A polishing mechanism is installed on the deflection seats; A self-locking motor for the deflection operation of the deflection seat is arranged at the bottom of the rear end of the jointed robotic arm; A transmission cover is arranged on the inner top surface of the processing cabinet. A transmission mechanism for driving the rotating table is arranged inside the transmission cover; A collection box is arranged at the lower part of the processing cabinet. An agitation assembly for preventing precipitation inside the collection box is arranged at the lower part of the transmission cover; A lifting groove is vertically formed in the middle of the top surface of the rotating table. An inner support mechanism for inner support of the semiconductor wafer is vertically arranged inside the lifting groove.

2. The CMP polishing machine for semiconductor wafers according to claim 1, wherein: The transmission mechanism includes a rotating gear ring fixed at the bottom of the rotating table, a fixing plate arranged on the inner wall of one side of the transmission cover, a servo motor arranged at the outer end of the top of the fixing plate, a driving gear arranged on the top of the servo motor, a rotating shaft rotatably arranged at the inner end of the top of the fixing plate, and a driven gear arranged at the top end of the rotating shaft. The driving gear is engaged with the teeth on the outer ring of the rotating gear ring for transmission, and the driven gear is engaged with the teeth on the inner ring of the rotating gear ring for transmission; A spline sleeve shaft is rotatably arranged in the middle of the bottom surface of the rotating table. A passive gear engaged with the driven gear is fixedly sleeved on the outer surface of the top of the spline sleeve shaft.

3. A CMP polishing machine for semiconductor wafers according to claim 2, characterized in that: The agitation assembly includes an agitation shaft rotatably arranged at the bottom of the transmission cover and an agitation blade fixedly connected to the bottom end of the agitation shaft. The agitation blade is in the shape of a twisted inclined plate. The top end of the agitation shaft movably penetrates into the transmission cover and is coaxially fixedly connected with a spline shaft. The spline shaft is inserted into the spline sleeve shaft.

4. A CMP polishing machine for semiconductor wafers according to claim 3, characterized in that: A plurality of cleaning strips extending into the slag collecting ring groove are equidistantly fixedly connected to the circumferential side of the outer wall of the upper part of the rotating table. The bottom of the cleaning strip is in close contact with the inner bottom surface of the slag collecting ring groove; Locking buckles are rotatably arranged at the lower parts of the front ends of both side walls of the protective cover, and buckles are fixedly connected to the front ends of both sides of the processing cabinet in cooperation with the locking buckles.

5. A CMP polishing machine for semiconductor wafers according to claim 4, characterized in that: The transverse movement assembly includes a transverse movement groove formed at the bottom of the mounting beam, a lead screw horizontally rotatably arranged in the transverse movement groove, and a moving seat sleeved on the lead screw. The electric turntable is installed at the bottom of the moving seat. A driving motor for driving the lead screw is arranged on one side of the protective cover.

6. A CMP polishing machine for semiconductor wafers according to claim 5, characterized in that: The polishing mechanism includes a sliding groove formed on the inner side surface of the deflection seat, a moving plate slidably arranged in the sliding groove, a polishing head fixedly connected to the outer end surface of the moving plate, a transmission groove formed in the middle of the sliding groove, and a pushing assembly arranged at both ends inside the transmission groove. A cooling cavity is formed inside the moving plate, and a liquid permeable cotton board is arranged inside the cooling cavity.

7. The CMP polishing machine for semiconductor wafers according to claim 6, characterized in that: A shunt pipe is bent upward inside the cooling cavity. The outer end of the shunt pipe penetrates into the transmission groove. A conduit groove communicated with the transmission groove is formed inside the deflection seat. A liquid injection pipe is arranged inside the conduit groove. The inner end of the liquid injection pipe is fixedly communicated with the outer end of the shunt pipe.

8. A CMP polishing machine for semiconductor wafers according to claim 7, characterized in that: The pushing assembly includes a rotating rod installed at both ends of the transmission groove and a transmission gear fixedly sleeved on the rotating rod. The upper and lower ends of the rear end surface of the deflection seat are provided with servo motors for driving the rotating rod. The inner side surface of the moving plate is fixedly connected with a rack plate meshing with the transmission gear.

9. A CMP polishing machine for semiconductor wafers according to claim 8, characterized in that: The inner support mechanism includes a lifting column vertically arranged inside the lifting slot, three storage slots arranged on the outer side of the lifting column, an inner support plate movably hinged inside the storage slot, a screw rod vertically rotatably arranged inside the storage slot and a micro motor installed at the bottom end of the screw rod, and the bottom end of the inner support plate is hinged in the bottom of the storage slot through a pin shaft; a mounting slot is vertically arranged on the bottom end surface of the lifting column, and an electric push cylinder is vertically arranged in the mounting slot, and the bottom end of the electric push cylinder is fixedly connected to the inner bottom surface of the lifting slot; a threaded sleeve is sleeved on the lower part of the screw rod, and an inner support rod is hinged on the threaded sleeve, and an articulated seat is fixedly connected to the upper end of the inner side surface of the inner support plate, and the top end of the inner support rod is movably hinged to the articulated seat, three anti-rotation strips are vertically arranged on the inner wall of the lifting slot, and three anti-rotation strip grooves are arranged on the outer surface of the lifting column to match the anti-rotation strips; a rubber anti-slip pad is provided on the outer end surface of the inner support plate.

10. A method of using a CMP polishing machine for semiconductor wafers, the CMP polishing machine for semiconductor wafers according to any one of claims 1-9, characterized in that, The following steps are involved: S1: First, the electric turntable, the joint robot arm, the servo motor, the electric push cylinder, the micro motor, the servo motor and the drive motor are electrically connected to the external control device through wires, and then the semiconductor wafer to be polished is turned upside down on the top of the turntable, and the anti-slip convex strips on the top of the turntable play a role of limiting and abutting the semiconductor wafer to be polished, and the outer end of the injection tube is connected to the external liquid supply device; S2: Then, the lifting column is pushed out of the lifting tank by starting the electric push cylinder, and the raised lifting column extends into the tank from the bottom opening of the semiconductor wafer, and then the micro motor is started to drive the screw to rotate, and the rotating screw can make the threaded sleeve push the inner support rod to expand outward, and the inner support can push the top of the inner support plate to expand outward, so that the inner support plate abuts against the inner wall of the semiconductor wafer, and then the semiconductor wafer to be polished is fixed and pressed down by the expanded inner support plate; S3: After positioning the semiconductor wafer to be polished, the drive motor is started to drive the lead screw to rotate. The rotation of the lead screw can make the movable seat adjust the position laterally at the bottom of the mounting beam. The movable seat connected by the position moving sleeve can drive the electric turntable to adjust the horizontal movement, so as to facilitate the electric turntable to move to the top of the semiconductor wafer. Then, the joint mechanical arm is started to drive the two deflection seats to perform a preliminary descent. Then, the self-locking motor at the bottom of the joint mechanical arm is started to drive the deflection seat to perform an angle deflection operation, so that the deflection seat can be deflected and adjusted according to the shape of the semiconductor wafer, so that the deflection seat can be adjusted to be tilted and adjusted to the inclination of the shape of the semiconductor wafer, so that the polishing head can have the same inclination as the outer surface of the semiconductor wafer. Then, the joint mechanical arm is started to drive the deflection seat to move, so that the polishing head installed on the deflection seat can fit and contact the outer surface of the semiconductor wafer. S4: Then, start the servo motor to drive the driving gear. Through the meshing of the driving gear and the rotating gear ring, the rotating table can be driven to rotate. Through the rotation of the rotating table, the placed semiconductor wafer can be driven to rotate. When the semiconductor wafer rotates, the polishing head on the deflection seat can polish the outer surface of the rotating semiconductor wafer; when it is necessary to adjust the height of the polishing head during the polishing process according to the height of the semiconductor wafer, start the servo motor to drive the transmission gear to rotate. Through the rotation of the transmission gear, the moving plate installed with the rack plate can be driven to slide up and down in the transmission groove of the deflection seat, so as to change the position of the polishing head on the deflection seat, which is convenient to meet the polishing operations of semiconductor wafers with different height dimensions and improve the application range of the device; and it can also make the polishing head move along the inclined outer surface of the semiconductor wafer during the polishing process; thus, the polishing area of the semiconductor wafer can be increased; S5: When the rotating table rotates, the semiconductor wafer is in a polishing state at this time. And in order to prevent the polishing head from overheating and drying, the external liquid supply device, the injection pipe and the shunt pipe inject liquid into the cooling cavity, and the liquid injection operation is carried out from the upper part to the lower part of the cooling cavity. And the water body can be fully dispersed by the liquid-permeable cotton board inside the cooling cavity. Then, the water is permeated to the polishing head through the liquid-permeable cotton board, so that the polishing head keeps a wet state, thus avoiding a large amount of flying dust when polishing the semiconductor wafer; moreover, the dust polished from the semiconductor wafer will fall into the slag collection ring groove. The cleaning strip driven by the rotating table can clean the waste residue falling into the slag collection ring groove into the slag outlet, and the waste residue falls into the collection box through the slag outlet; S6: The teeth on the inner ring of the rotating gear ring drive the driven gear to rotate; through the meshing of the driven gear and the passive gear, the spline sleeve shaft is driven to rotate. The stirring shaft provided with a spline shaft is driven to rotate by the rotating spline sleeve shaft. The stirring blades are driven to stir the waste residue in the collection box by the rotating stirring shaft, so as to prevent the waste residue mixed with water from precipitating in the collection box.

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