Photoelectrochemical mechanical polishing device and method for global irradiation wafer

Abstract

The invention discloses a photoelectrochemical mechanical polishing device and method for a global irradiation wafer, the device comprises a box body, a lower disc system, a polishing head unit, an overturning gantry unit and a liquid receiving basin, and the lower disc system comprises a polishing disc unit and a lower disc transmission mechanism. According to the invention, rapid and stable clamping of the wafer is realized by adopting the overturning gantry structure; the hollow speed reducer is used for transmission, power speed reduction and torque increasing stable transmission are guaranteed, meanwhile, integrated wiring and liquid flowing are facilitated through the hollow design, and the structural layout is optimized; positive logarithmic spiral grooves are formed in the surface of the quartz disc, polishing liquid is guided to uniformly flow and distribute, a uniform electric field is constructed in combination with central power output design, and the strength and uniformity of photoelectrochemical reaction are enhanced; a surface light source is formed by compensating the light intensity of adjacent lamp beads, so that the global high-uniformity and high-illumination-intensity irradiation of a wafer processing area is realized, and the photoelectrocatalysis consistency is guaranteed; according to the invention, the material removal rate of photoelectrochemical mechanical polishing can be improved, and the surface quality can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of polishing processing, in particular, especially relates to a photoelectrochemical mechanical polishing device and method for global irradiation wafer. BACKGROUND

[0002] Current semiconductor wafers are the core basic components supporting the development of strategic emerging industries such as new energy, 5G communication, aerospace, and high-end equipment. Among them, the third-generation wide-bandgap semiconductor wafers represented by silicon carbide and gallium nitride are widely used in key fields such as new energy vehicle power modules, 5G base station radio frequency devices, and spacecraft power systems due to their superior performance of high frequency, high efficiency, high voltage resistance, and high temperature resistance. With the continuous upgrading of performance requirements in these fields, the processing precision standards of semiconductor wafers also increase: on the one hand, the wafer surface needs to be uniformly polished to avoid local scratches and micro-defects; on the other hand, the degree of subsurface damage needs to be controlled while maintaining a high material removal rate to prevent performance failures in subsequent device manufacturing processes. In addition, the gradual popularization of large-size wafers also puts higher requirements on the specification adaptability of processing devices to ensure the consistency of different specifications during wafer processing and meet the needs of industrial mass production.

[0003] In existing semiconductor wafer polishing technology, although traditional chemical mechanical polishing (CMP) technology can achieve a certain degree of surface processing, it has the disadvantages of low material removal efficiency, poor adaptability to hard and brittle materials such as wide-bandgap semiconductors, and easy subsurface damage caused by free abrasives, making it difficult to meet the precision processing needs of third-generation semiconductor wafers. As an upgrade solution, photoelectrochemical mechanical polishing (PECMP) technology has obvious advantages in material removal rate and surface quality improvement through the synergistic effect of photoelectrochemical oxidation and mechanical removal. However, the existing PECMP technology still has many limitations: first, conventional devices mostly use a polishing disc on top and wafer on bottom structure, and the polishing disc is made of metal with a light-transmitting hole. The hole design not only reduces the mechanical strength of the polishing disc, but also causes the non-hole area to block the light, reducing light utilization. Second, the light source layout is mostly single-point or linear, making it difficult to achieve uniform irradiation of the wafer, and local light differences can easily lead to uneven thickness of the wafer surface oxide layer, causing polishing quality fluctuations. Third, existing technologies mostly use free abrasive polishing liquid, which has poor controllability of abrasive particles and high cost of subsequent waste liquid treatment. Moreover, the design of the conductive structure and the polishing liquid channel lacks coordination, the current distribution is uneven, and a stable photoelectrochemical oxidation environment cannot be formed. Fourth, existing related patents such as CN1096484631 mostly use a guide rail slider structure for the polishing head movement structure, which lacks flexibility in wafer loading and unloading adjustment, making it difficult to adapt to the stable clamping of wafers. SUMMARY

[0004] In order to solve the above problems existing in the prior art, the present application provides a photoelectrochemical mechanical polishing device and method for irradiating a wafer in the whole domain, so as to achieve the following purposes: solving the problems of easy shielding of light and insufficient utilization, realizing efficient utilization of ultraviolet light; solving the problem of uneven irradiation caused by the layout of traditional light sources, realizing high uniformity and high light intensity irradiation of the wafer in the whole domain, and guaranteeing uniform generation of photoelectric oxidation layer; solving the problems of lack of cooperation between polishing liquid flow and current transmission and uneven current distribution, enhancing the intensity and uniformity of photoelectrochemical reaction, and improving the poor controllability of free abrasive and the high cost of waste liquid treatment; solving the problem of inconvenient feeding and discharging of the wafer in the traditional guide rail slider structure, realizing rapid and stable clamping of the wafer; through the synergistic effect of various mechanisms, the problem of insufficient uniformity of the whole polishing is solved, and finally the stability and overall quality of the wafer precision machining are improved.

[0005] The technical means adopted by the present application are as follows: A photoelectrochemical mechanical polishing device for irradiating a wafer in the whole domain, comprising a box body, a lower disc system, a polishing head unit, a turnover gantry unit and a liquid receiving basin, the lower disc system is fixedly installed in the box body, the polishing head unit is fixedly connected with the turnover gantry unit, the turnover gantry unit is installed on the upper part of the box body, and the liquid receiving basin is installed on the central part of the upper end face of the box body. The lower disc system comprises a polishing disc unit and a lower disc transmission mechanism, and the polishing disc unit is installed on the lower disc transmission mechanism.

[0006] Further, the polishing disc unit comprises a center gland, an ultraviolet lamp plate and a polishing disc, the ultraviolet lamp plate is fixed on the lower disc transmission mechanism, the polishing disc is installed on the ultraviolet lamp plate, and the center gland is embedded in the center of the polishing disc.

[0007] Further, the lower disc transmission mechanism comprises a support disc, a lower support disc, a cross cylindrical roller bearing, a deep groove ball bearing, a lower disc system main shaft, a liquid blocking plate, a pull rod, a speed reducer belt pulley, a hollow speed reducer, a motor C, a motor C bottom plate, a motor C belt pulley, a speed reducer mounting seat, a bottom plate and an electric slip ring, the speed reducer mounting seat is fixed on the bottom plate, the motor C is installed on the bottom plate through the motor C bottom plate, the hollow speed reducer is fixed on the speed reducer mounting seat and connected with the lower support disc, and the lower disc system main shaft penetrates downward through the hollow speed reducer and is connected with the electric slip ring; the lower support disc is connected with the support disc through the cross cylindrical roller bearing and connected with the lower disc system main shaft through the deep groove ball bearing; the outer ring of the cross cylindrical roller bearing is installed on the lower support disc, and the inner ring is installed in cooperation with the support disc, the outer ring of the deep groove ball bearing is installed on the lower support disc, and the inner ring is installed in cooperation with the lower disc system main shaft; the support disc is installed above the lower disc system main shaft, and the liquid blocking plate is installed around the support disc.

[0008] Further, the polishing head unit includes a loading cylinder, an upper mounting plate, a loading cylinder connecting rod, a floating joint, an adapter, a force sensor, a side plate, a motor A, a pneumatic-electric slip ring, an upper adapter for the pneumatic-electric slip ring, a lower adapter for the pneumatic-electric slip ring, a spline shaft, a motor A mounting plate, a spline nut, a motor transmission mechanism, a lower support plate, a lower mounting plate, a bearing support, a spindle angular contact ball bearing, a polishing head spindle sleeve, a sealing sleeve, a universal adjustment platform, and a conductive vacuum chuck. The side plate is fixed to both sides of the upper mounting plate, forming a portal frame, and is fixed to the lower mounting plate by the lower support plate. The lower mounting plate is fixed to the slider. The loading cylinder is fixed to the upper mounting plate. The loading cylinder connecting rod passes downward through the upper mounting plate and connects to the upper end of the floating joint. The upper and lower ends of the force sensor are respectively connected to the lower end of the floating joint and the upper side of the upper adapter for the pneumatic-electric slip ring through adapters. The pneumatic-electric slip ring rotates downward... The connector is mounted on the splined shaft via bearings; the stator of the pneumatic slip ring is mounted on the adapter of the pneumatic slip ring, and the rotor is connected to the upper end of the splined shaft; the splined nut mates with the splined shaft; the motor A is mounted on the side plate via the motor A mounting plate, and transmits power to the splined shaft via the motor transmission mechanism, which is mounted on the motor A and mates with the splined shaft; the polishing head spindle sleeve is fixed to the lower side of the lower mounting plate, and the sealing sleeve is fixedly connected to the lower end of the polishing head spindle sleeve; there are two spindle angular contact ball bearings, both installed inside the polishing head spindle sleeve, one installed between the end of the splined nut and the upper surface of the sealing sleeve, and the other mates with the splined nut; the bearing support is installed between the two spindle angular contact ball bearings; a universal adjustment platform is mounted on the lower end of the splined shaft, and the lower side of the universal adjustment platform is connected to a conductive vacuum chuck, which adsorbs wafers on its lower side.

[0009] Furthermore, the tilting gantry unit includes a tilting mechanism and a lateral movement mechanism. The tilting mechanism is fixed on the housing, and the lateral movement mechanism is mounted on the tilting mechanism. The flipping mechanism has a symmetrical structure and includes a double-elbow Y-joint, cylinder connecting rod, rotating shaft, oil-free bushing, column, cylinder, cylinder mounting base, main mounting plate, upper cylinder mounting plate, side cylinder mounting plate, positioning block, and locking cylinder. The upper cylinder mounting plate is fixed above the side cylinder mounting plate. There are two side cylinder mounting plates on each side, fixed to the main mounting plate and mounted on both sides of the upper cylinder mounting plate along the front-back direction, forming a portal frame. The cylinders are mounted on the housings on the left and right sides of the main mounting plate, and the flipping angle of the main mounting plate is changed by adjusting the air pressure. The moving end of the cylinder is fixedly connected to the cylinder mounting seat and cylinder connecting rod via the cylinder mounting plate and hinged to the double elbow Y-shaped joint; the fixed end of the cylinder is hinged to the housing via the cylinder mounting seat; there are four columns, distributed at the four corners of the tilting mechanism and all fixed to the housing; the rotating shaft is installed on the rear side of the main mounting plate and rotatably connected to the oil-free bushing on the rear column; the oil-free bushing is fixed to the column; the positioning block is fixedly installed on the left and right corners of the front side of the main mounting plate; the locking cylinder is fixed on the left and right columns of the front side; the moving end of the locking cylinder cooperates with the corresponding positioning block to fix the tilting mechanism.

[0010] The lateral movement mechanism includes a spherical bearing mounting base, a crank connecting rod, a crank turntable, sliders, guide rails, and motor B. The spherical bearing mounting base is fixedly connected to the lower mounting plate in the polishing head unit. The two ends of the crank connecting rod are respectively hinged to the spherical bearing mounting base and the crank turntable, driving the polishing head unit to perform lateral reciprocating motion. The crank turntable is mounted on motor B, which is fixed to the lower surface of the main mounting plate and drives the crank turntable to rotate. The guide rails are fixed to the upper surface of the main mounting plate, and the two guide rails are parallel to each other. The sliders are mounted on the guide rails, with two sliders on each guide rail, and the four sliders are distributed at the four corners of the lower mounting plate of the polishing head unit.

[0011] Furthermore, the polishing disc unit adopts a center-powered structure, which uniformly conducts current from the center of the polishing disc to the periphery, thereby constructing a uniform electric field throughout the entire area.

[0012] Furthermore, the ultraviolet lamp panel has multiple small LEDs evenly distributed on its upper surface, and the light intensity of adjacent LEDs compensates for each other to provide a stable surface light source.

[0013] Furthermore, the polishing disc is made of transparent quartz material, and the surface of the polishing disc is provided with logarithmic spiral grooves to guide the polishing fluid to form a stable and orderly flow trajectory.

[0014] Furthermore, the crank turntable is provided with three through holes, and the crank connecting rod is installed in the through holes at different distances from the center of the crank turntable according to different requirements, so as to adjust the reciprocating stroke.

[0015] A photoelectrochemical mechanical polishing method for whole-area irradiated wafers, comprising the following steps, using the aforementioned photoelectrochemical mechanical polishing apparatus for whole-area irradiated wafers: S1. By adjusting the air pressure in the cylinder, the flipping angle of the flipping mechanism is increased, the wafer to be polished is placed on the universal adjustment platform, and the conductive vacuum chuck is used to complete the adsorption. S2. Reduce the flipping angle of the flipping mechanism to move the wafer down to near the upper surface of the polishing pad, and fix the flipping mechanism by locking cylinder and positioning block; S3. Power on the polishing head unit and polishing disk unit so that the upper surface of the wafer to be polished is connected to the positive terminal of the power supply, and the lower surface is connected to the negative terminal of the power supply through the polishing liquid. S4. Turn on the ultraviolet lamp so that the ultraviolet light can pass through the polishing pad and shine on the wafer to be polished, providing a stable surface light source for the wafer; S5. Start pouring polishing liquid into the receiving basin to ensure that the upper surface of the polishing pad is evenly wetted, and complete the polishing pretreatment. S6. Adjust the loading cylinder to make the wafer to be polished contact the upper surface of the polishing pad, and at the same time use the force sensor to detect the pressure on the contact surface between the wafer and the polishing pad until the pressure reaches the predetermined value. S7. Turn on motors C and A, and the hollow reducer to make the polishing disc and polishing head unit rotate to the specified speed. Turn on motor B to drive the polishing head unit to move laterally at the specified speed; S8. Activate the feedback adjustment program to ensure that the polishing disc speed, polishing head unit speed, polishing head unit lateral movement speed, pressure supply wire output voltage, and cylinder air pressure are within the specified requirements. This achieves the polishing of the wafer surface.

[0016] Compared with the prior art, the present invention has the following advantages: 1. The polishing disc of the present invention is made of transparent quartz material, which can avoid blocking light and improve the utilization rate of ultraviolet light.

[0017] 2. This invention uses a surface light source, combined with an adjacent LED light intensity compensation mechanism, which helps to achieve high uniformity and high light intensity irradiation across the entire wafer processing area, avoiding uneven photoelectric reaction caused by local light differences and ensuring consistent photoelectrocatalysis. 3. The polishing pad of the present invention has logarithmic spiral grooves on its surface to guide the polishing liquid to flow and distribute evenly. Combined with the center-outlet design to construct a uniform electric field, it can enhance the intensity and uniformity of photoelectrochemical reaction and reduce the surface quality difference of the wafer after polishing. 4. The present invention adopts a structure with the polishing pad at the bottom and the wafer at the top, which allows the polishing slurry to evenly cover the processing contact surface between the wafer and the polishing pad, reducing the loss of polishing slurry. At the same time, the retention and flow of polishing slurry are more controllable, and the subsequent waste liquid treatment cost and difficulty are lower.

[0018] 5. This invention uses a gantry flip structure to replace the traditional fixed structure, which can flexibly adjust the flip angle to achieve fast and stable clamping of wafers and improve the convenience of loading and unloading. 6. This invention utilizes a hollow reducer transmission to achieve stable power transmission with reduced speed and increased torque. At the same time, it integrates wiring and fluid flow through the hollow structure, optimizes the device's structural layout, and reduces the impact of transmission errors on polishing accuracy. 7. This invention converts rotational motion into transverse reciprocating linear motion through a crank and connecting rod, driving the polishing head unit to achieve large-area uniform sweeping, increasing the complexity of the relative motion trajectory between the wafer and the polishing disk, achieving uniform polishing of the entire wafer area, and the reciprocating motion stroke can be adjusted by changing the installation position of the crank and connecting rod, which has high flexibility and adaptability. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a photoelectrochemical mechanical polishing device for global irradiation of wafers.

[0020] Figure 2 This is a schematic diagram of the lower plate system structure of the present invention.

[0021] Figure 3 This is a schematic diagram of the polishing head unit structure of the present invention.

[0022] Figure 4 This is a schematic diagram of the flip-over gantry unit structure of the present invention.

[0023] Figure 5 This is a schematic diagram of the conductive circuit of the present invention.

[0024] Figure 6 This is a flowchart of the process of the present invention.

[0025] Figure 7 This is a diagram illustrating the lighting effect of the present invention.

[0026] Figure 8 This is a schematic diagram of the optical path of the present invention.

[0027] In the diagram: 1. Housing, 2. Lower platen system, 21. Polishing disc unit, 211. Center cap, 212. Polishing disc, 213. UV lamp plate, 22. Lower platen transmission mechanism, 221. Support plate, 222. Lower support plate, 223. Crossed cylindrical roller bearing, 224. Deep groove ball bearing, 225. Lower platen system spindle, 226. Baffle plate, 227. Tie rod, 228. Reducer pulley, 229. Hollow reducer, 2210. Motor C, 22 11. Motor C base plate; 2212. Motor C pulley; 2213. Reducer mounting base; 2214. Base plate; 2215. Electric slip ring; 3. Polishing head unit; 31. Loading cylinder; 32. Upper mounting plate; 33. Loading cylinder connecting rod; 34. Floating joint; 35. Adapter; 36. Force sensor; 37. Side plate; 38. Motor A; 39. Pneumatic-electric slip ring; 310. Upper adapter of pneumatic-electric slip ring; 311. Lower adapter of pneumatic-electric slip ring; 312. Flower 313. Key shaft; 314. Motor A mounting plate; 315. Spline nut; 316. Motor transmission mechanism; 317. Lower support plate; 318. Lower mounting plate; 319. Bearing support; 320. Spindle angular contact ball bearing; 321. Polishing head spindle sleeve; 322. Sealing sleeve; 323. Universal adjustment platform; 324. Conductive vacuum chuck; 4. Wafer; 4. Tilting gantry unit; 41. Tilting mechanism; 412. Double elbow Y-joint; 413. Cylinder connecting rod. 413. Rotating shaft; 414. Oil-free bushing; 415. Column; 416. Cylinder; 417. Cylinder mounting base; 418. Main mounting plate; 419. Upper cylinder mounting plate; 4110. Side cylinder mounting plate; 4111. Positioning block; 4112. Locking cylinder; 42. Lateral movement mechanism; 421. Spherical bearing fixing seat; 422. Crank connecting rod; 423. Crank turntable; 424. Slider; 425. Guide rail; 426. Motor B; 5. Liquid receiving basin. Detailed Implementation

[0028] The present invention will be further described below with reference to specific embodiments. The accompanying drawings are for illustrative purposes only, representing schematic diagrams rather than actual physical objects, and should not be construed as limiting the scope of this patent. To better illustrate the embodiments of the present invention, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0029] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0030] like Figures 1-5 As shown, a photoelectrochemical mechanical polishing device for full-area irradiation of wafers includes a housing 1, a lower plate system 2, a polishing head unit 3, a tilting gantry unit 4, and a liquid receiving basin 5. The lower plate system 2 is fixedly installed inside the housing 1. The polishing head unit 3 is fixedly connected to the tilting gantry unit 4. The tilting gantry unit 4 is installed on the upper part of the housing 1. The liquid receiving basin 5 is installed at the center of the upper end face of the housing 1. The lower plate system 2 includes a polishing plate unit 21 and a lower plate transmission mechanism 22, wherein the polishing plate unit 21 is mounted on the lower plate transmission mechanism 22.

[0031] In order to facilitate the loading and unloading of wafers and achieve conductivity, the polishing head unit 3 uses a conductive vacuum chuck 323 to adsorb the wafer 324. The conductive vacuum chuck 323 has a ceramic substrate and a porous stainless steel upper surface, which has good conductivity and oxidation resistance. During operation, it can adsorb the wafer 324, so that the bottom surface of the wafer 324 is in close contact with the polishing disk 212. The lower surface of the wafer 324 is connected to the working electrode of the electrochemical workstation through the gas-electric slip ring 39.

[0032] like Figures 1-8 As shown, the present invention also discloses a photoelectrochemical mechanical polishing method for whole-area irradiated wafers, comprising the following steps: S1. By adjusting the air pressure in the cylinder 416, the flipping angle of the flipping mechanism 41 is increased, the wafer 324 to be polished is placed on the universal adjustment platform 322, and the vacuum suction cup is used to complete the adsorption. S2. Reduce the flipping angle of the flipping mechanism 41 so that the wafer 324 moves down to the vicinity of the upper surface of the polishing disk 212. By adjusting the air pressure of the locking cylinder 4112, the moving end of the locking cylinder 4112 is inserted into the corresponding positioning block 4111 to fix the flipping mechanism 41. S3. Power on the polishing head unit 3 and the polishing disk unit 21 with a voltage of about 5V, so that the upper surface of the wafer 324 to be polished is connected to the positive terminal of the power supply, and the lower surface is connected to the negative terminal of the power supply through the polishing liquid. S4. Turn on the ultraviolet lamp with a wavelength range of 315nm~400nm, so that the ultraviolet light can pass through the polishing disk 212 and irradiate the wafer 324 to be polished, providing a stable surface light source for the wafer 324. S5. Start injecting polishing liquid into the receiving basin 5 to ensure that the upper surface of the polishing disc 212 is evenly wetted, and complete the polishing pretreatment. S6. Adjust the air pressure of the loading cylinder 31 to make the wafer 324 to be polished contact the upper surface of the polishing disk 212. At the same time, the force sensor 36 detects the pressure on the contact surface. When the real-time data fed back by the force sensor 36 shows that the predetermined value of 3.6psi has been reached, the cylinder 416 stops supplying air. S7. Turn on motors C2210 and A38 and the hollow reducer 229 to make the polishing disc 212 and polishing head unit 3 rotate to the specified speed. Turn on motor B to drive the polishing head unit 3 to move laterally at the specified speed. Observing from top to bottom, with clockwise as positive, the specified speed of the polishing disc 212 is 100 rpm, the specified speed of the wafer 324 is 90 rpm, and the specified speed of the lateral movement of the polishing head unit 3 is 50 mm / s. S8. Activate the feedback adjustment program to stabilize the rotational speed of the polishing disc 212 and the polishing head unit 3, stabilize the lateral movement speed of the polishing head unit 3, and maintain a stable output voltage value of the pressure supply wire. Based on the real-time data from the force sensor 36, use the negative feedback adjustment system to control the air pressure of the cylinder 416 to maintain stable pressure. This achieves polishing of the surface of the wafer 324.

[0033] Example like Figures 1-8 As shown, a photoelectrochemical mechanical polishing (CMP) device for full-area irradiation of wafers includes a housing 1, a lower plate system 2, a polishing head unit 3, a tilting gantry unit 4, and a liquid receiving basin 5. The lower plate system 2 includes a polishing disc unit 21 and a lower plate transmission mechanism 22. The polishing head unit 3 includes a loading cylinder 31 for applying working pressure, a pressure sensor 36 and its connected pneumatic-electric slip ring 39 transmitted through a floating joint 34, and a further transmission of the working pressure to a conductive vacuum chuck 323 via a splined shaft 312 and a splined nut 314. Machine A38 transmits rotational torque to spline shaft 312 through motor transmission mechanism 315 and drives the wafer to rotate. The flip gantry unit 4 includes a flip gantry unit installed on housing 1 and a transverse moving mechanism 42 installed on main mounting plate 418. Housing 1 serves as the overall base of the device. The lower plate system 2 is fixedly installed inside housing 1. Polishing head unit 3 is fixedly connected to flip gantry unit 4. Flip gantry unit 4 is installed on the upper part of housing 1. Liquid receiving basin 5 is installed in the center of the upper end face of housing 1.

[0034] In this embodiment, the polishing disc unit 21 has an ultraviolet lamp plate 213 with lamp beads arranged in a specific array structure, and a polishing disc 212 with logarithmic spiral grooves on its surface is mounted on the ultraviolet lamp plate 213, with a central pressure cap 211 embedded in the center of the polishing disc 212.

[0035] In this embodiment, the polishing head unit 3 applies working pressure to the wafer through the loading cylinder 31, and the force sensor 36 is connected to the loading cylinder 31 through the floating joint 34 and the adapter 35 and monitors the applied pressure of the loading cylinder 31 in real time.

[0036] In this embodiment, the flipping gantry unit 4 is equipped with a motor B426, which can drive the polishing head unit 3 to perform lateral reciprocating motion through the joint bearing fixing seat 421, crank connecting rod 422 and crank turntable 423.

[0037] Specifically, the wavelength of light emitted by the lamp beads in the ultraviolet lamp panel 213 is 365 nm, and the arrangement can be a foliated structure, a radial structure, or an array structure; the polishing disk 212 is made of transparent quartz material with high light transmittance; the combination of lamp beads and polishing disk forms an optical path, allowing ultraviolet light to directly irradiate the wafer.

[0038] Specifically, the polishing disc unit 21 is connected to the negative electrode of the electrochemical workstation via an electric slip ring 2215.

[0039] Specifically, in the lower plate system 2, the reducer pulley 228 is the driven pulley, and the motor C pulley 2212 is the driving pulley. The motor C2210 transmits power to the hollow reducer 229 through the driving and driven pulleys, thereby driving the entire lower plate system to rotate.

[0040] Specifically, in the polishing head unit 3, the conductive vacuum chuck 323 is connected to the anode of the electrochemical workstation through the gas-electric slip ring 39, and the motor A38 transmits the rotational torque to the spline shaft through the motor transmission mechanism and drives the wafer to rotate.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An apparatus for photoelectrochemical mechanical polishing of a global irradiance wafer, comprising: a chuck for holding the wafer; a light source for illuminating the wafer; a polishing pad; and a polishing head for moving the polishing pad over the wafer. The utility model relates to a polishing machine, including box (1), lower disc system (2), polishing head unit (3), overturn gantry unit (4) and liquid receiving basin (5), lower disc system (2) fixed mounting in box (1), polishing head unit (3) with overturn gantry unit (4) fixed connection, overturn gantry unit (4) install on the upper portion of box (1), liquid receiving basin (5) install in the central of the upper end surface of box (1), Lower disc system (2) includes polishing disc unit (21) and lower disc transmission mechanism (22), polishing disc unit (21) is installed on lower disc transmission mechanism (22).

2. The apparatus for photoelectrochemical mechanical polishing of a global irradiance wafer as recited in claim 1, wherein: Polishing disc unit (21) includes center gland (211), ultraviolet lamp plate (213) and polishing disc (212), ultraviolet lamp plate (213) is fixed on lower disc transmission mechanism (22), polishing disc (212) is installed on ultraviolet lamp plate (213), center gland (211) is embedded in the center of polishing disc (212).

3. The apparatus for photoelectrochemical mechanical polishing of a global irradiance wafer as recited in claim 1, wherein: Lower disc transmission mechanism (22) includes support disc (221), lower support disc (222), cross cylindrical roller bearing (223), deep groove ball bearing (224), lower disc system main shaft (225), liquid baffle (226), pull rod (227), speed reducer pulley (228), hollow speed reducer (229), motor C (2210), motor C bottom plate (2211), motor C pulley (2212), speed reducer mounting seat (2213), bottom plate (2214) and electric slip ring (2215), speed reducer mounting seat (2213) is fixed on bottom plate (2214), motor C (2210) is installed on bottom plate (2214) through motor C bottom plate (2211), hollow speed reducer (229) is fixed on speed reducer mounting seat (2213) and is connected with lower support disc (222), lower disc system main shaft (225) passes down through hollow speed reducer (229) and is connected with electric slip ring (2215); Lower support disc (222) is connected with support disc (221) through cross cylindrical roller bearing (223) and is connected with lower disc system main shaft (225) through deep groove ball bearing (224); Cross cylindrical roller bearing (223) outer ring is installed on lower support disc (222), and inner ring is installed in coordination with support disc (221), deep groove ball bearing (224) outer ring is installed on lower support disc (222), and inner ring is installed in coordination with lower disc system main shaft (225); Support disc (221) is installed on the upper portion of lower disc system main shaft (225), and liquid baffle (226) is installed around support disc (221).

4. The apparatus for photoelectrochemical mechanical polishing of a global irradiance wafer as recited in claim 1, wherein: The polishing head unit (3) comprises a loading cylinder (31), an upper mounting plate (32), a loading cylinder connecting rod (33), a floating joint (34), an adapter (35), a force sensor (36), a side plate (37), a motor A (38), an air-electric slip ring (39), an air-electric slip ring upper adapter (310), an air-electric slip ring lower adapter (311), a spline shaft (312), a motor A mounting plate (313), a spline female (314), a motor transmission mechanism (315), a lower side support plate (316), a lower mounting plate (317), a bearing support (318), a main shaft angular contact ball bearing (319), a polishing head main shaft sleeve (320), a sealing sleeve (321), a universal adjustment platform (322), and a conductive vacuum chuck (323). The side plate (37) is fixed on both sides of the upper mounting plate (32) to form a door-shaped frame, and is fixed on the lower mounting plate (317) through the lower side support plate (316). The lower mounting plate (317) is fixed on the sliding block (424). The loading cylinder (31) is fixed on the upper mounting plate (32). The loading cylinder connecting rod (33) passes through the upper mounting plate (32) downwardly and is connected with the upper end of the floating joint (34). The upper and lower ends of the force sensor (36) are connected with the lower end of the floating joint (34) and the upper side of the air-electric slip ring upper adapter (310) through the adapter (35). The air-electric slip ring lower adapter (311) is installed on the spline shaft (312) through a bearing. The stator of the air-electric slip ring (39) is installed on the air-electric slip ring upper adapter (310), and the rotor is connected with the upper end of the spline shaft (312). The spline female (314) cooperates with the spline shaft (312). The motor A (38) is installed on the side plate (37) through the motor A mounting plate (313), and transmits power to the spline shaft (312) through the motor transmission mechanism (315). The motor transmission mechanism (315) is installed on the motor A (38) and cooperates with the spline shaft (312). The polishing head main shaft sleeve (320) is fixed on the lower side of the lower mounting plate (317). The sealing sleeve (321) is fixedly connected to the lower end of the polishing head main shaft sleeve (320). The main shaft angular contact ball bearing (319) is installed in the polishing head main shaft sleeve (320). One is installed between the end of the spline female (314) and the upper surface of the sealing sleeve (321), and the other cooperates with the spline female (314). The bearing support (318) is installed between the two main shaft angular contact ball bearings (319). The lower end of the spline shaft (312) is installed with the universal adjustment platform (322). The universal adjustment platform (322) is connected with the conductive vacuum chuck (323) on the lower side. The lower side of the conductive vacuum chuck (323) adsorbs the wafer (324).

5. The apparatus for photoelectrochemical mechanical polishing of a global irradiance wafer as recited in claim 1, wherein: The overturning gantry unit (4) comprises an overturning mechanism (41) and a transverse moving mechanism (42). The overturning mechanism (41) is fixed on the box body (1). The transverse moving mechanism (42) is installed on the overturning mechanism (41). The turnover mechanism (41) is a left-right symmetrical structure, and the turnover mechanism (41) comprises a double elbow Y-shaped joint (411), a cylinder connecting rod (412), a rotating shaft (413), an oil-free bushing (414), a stand column (415), a cylinder (416), a cylinder mounting seat (417), a total mounting plate (418), a cylinder upper mounting plate (419), a cylinder side mounting plate (4110), a positioning block (4111), and a locking cylinder (4112). The cylinder upper mounting plate (419) is fixed above the cylinder side mounting plate (4110). The cylinder side mounting plate (4110) is provided with two plates on the left and right sides, is fixed on the total mounting plate (418), is installed on the left and right sides of the cylinder upper mounting plate (419) in the front-rear direction respectively, and forms a door-shaped frame. The cylinder (416) is installed on the left and right sides of the total mounting plate (418) on the box body (1) respectively, and the turnover angle of the total mounting plate (418) is changed by adjusting the air pressure. The moving end of the cylinder (416) is fixedly connected with the cylinder upper mounting plate (419) through the cylinder mounting seat (417) and the cylinder connecting rod (412), is hinged with the double elbow Y-shaped joint (411), and the fixed end of the cylinder (416) is hinged with the box body (1) through the cylinder mounting seat (417). The stand column (415) is provided with four stand columns, which are distributed at the four corners of the turnover mechanism (41) and are fixed on the box body (1). The rotating shaft (413) is installed on the rear side of the total mounting plate (418) and is rotationally connected with the oil-free bushing (414) on the rear stand column (415). The oil-free bushing (414) is fixed on the stand column (415). The positioning block (4111) is fixedly installed on the left and right corners of the front side of the total mounting plate (418). The locking cylinder (4112) is fixed on the left and right stand columns (415) on the front side. The moving end of the locking cylinder (4112) is matched with the corresponding positioning block (4111) and is used for fixing the turnover mechanism (41). The transverse moving mechanism (42) comprises a joint bearing fixing seat (421), a crank connecting rod (422), a crank rotating disc (423), a sliding block (424), a guide rail (425), and a motor B (426). The joint bearing fixing seat (421) is fixedly connected with the lower mounting plate (317) in the polishing head unit (3). The two ends of the crank connecting rod (422) are hinged with the joint bearing fixing seat (421) and the crank rotating disc (423) respectively, drive the polishing head unit (3) to perform transverse reciprocating motion. The crank rotating disc (423) is installed on the motor B (426). The motor B (426) is fixed on the lower surface of the total mounting plate (418) and drives the crank rotating disc (423) to rotate. The guide rail (425) is fixed on the upper surface of the total mounting plate (418). Two guide rails (425) are parallel to each other. The sliding block (424) is installed on the guide rail (425). There are two sliding blocks (424) on each guide rail (425). Four sliding blocks (424) are distributed at the four corners of the lower mounting plate (317) of the polishing head unit (3).

6. The apparatus for photoelectrochemical mechanical polishing of a global radiation wafer as recited in claim 1, wherein: The polishing disc unit (21) adopts a center power supply structure to uniformly conduct current from the center to the periphery of the polishing disc (212) to build a global uniform electric field.

7. The apparatus for photoelectrochemical mechanical polishing of a global irradiance wafer as recited in claim 1, wherein: The ultraviolet lamp panel (213) has a plurality of small lamp beads uniformly distributed on its upper surface, and the light intensity of adjacent lamp beads compensates each other to provide a stable surface light source.

8. The apparatus for photoelectrochemical mechanical polishing of a global irradiance wafer as recited in claim 1, wherein: The polishing disc (212) adopts transparent quartz material, and the surface of the polishing disc (212) is provided with a directly opposite number spiral groove for guiding the polishing liquid to form a stable and orderly flow track.

9. The apparatus for photoelectrochemical mechanical polishing of a global irradiance wafer as recited in claim 1, wherein: The crank rotating disc (423) is provided with three through holes, and the crank connecting rod (422) is installed in the through holes with different distances from the center of the crank rotating disc (423) according to different requirements to adjust the reciprocating stroke.

10. A photoelectrochemical mechanical polishing method for global irradiation wafer, which is polished by the photoelectrochemical mechanical polishing device for global irradiation wafer according to any one of claims 1-9, comprising the following steps: S1, by adjusting the air pressure in the air cylinder (416), the overturning angle of the overturning mechanism (41) is increased, the wafer (324) to be polished is placed on the universal adjusting platform (322), and the conductive vacuum chuck (323) is used to complete the adsorption; S2, the overturning angle of the overturning mechanism (41) is reduced, the wafer (324) is moved downward to the vicinity of the upper surface of the polishing disc (212), and the overturning mechanism (41) is fixed by the locking air cylinder (4112) and the positioning block (4111); S3, power is supplied to the polishing head unit (3) and the polishing disc unit (21), so that the upper surface of the wafer (324) to be polished is connected with the positive electrode of the power supply, and the lower surface is connected with the negative electrode of the power supply through the polishing liquid; S4, the ultraviolet lamp is turned on, and the ultraviolet light can penetrate the polishing disc (212) to irradiate on the wafer (324) to be polished, and a stable surface light source is provided for the wafer (324); S5, the polishing liquid is injected into the liquid basin (5) to ensure that the upper surface of the polishing disc (212) is uniformly wetted, and the polishing pretreatment is completed; S6, the loading air cylinder (31) is adjusted to make the wafer (324) to be polished contact with the upper surface of the polishing disc (212), and the force sensor (36) detects the pressure of the contact surface of the wafer (324) and the polishing disc (212) until the pressure reaches a predetermined value; S7, the motor C (2210), the motor A (38) and the hollow speed reducer (229) are started, so that the polishing disc (212) and the polishing head unit (3) rotate to reach a specified speed; the motor B (426) is started to drive the polishing head unit (3) to move laterally at a specified speed; S8, the feedback adjustment program is started, so that the rotation speed of the polishing disc (212), the rotation speed of the polishing head unit (3), the lateral movement speed of the polishing head unit (3), the output voltage of the voltage supply line and the air pressure of the air cylinder (416) are within the specified requirements; the polishing of the surface of the wafer (324) is realized.

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