Wafer photoelectrochemical mechanical planarization device and method

Abstract

The invention provides a wafer photoelectrochemical mechanical planarization device and method.The wafer photoelectrochemical mechanical planarization device comprises a machining platform, a first polishing disc and a second polishing disc, a first polishing head and a first polishing solution spraying pipe are arranged above the first polishing disc, and a second polishing head and a second polishing solution spraying pipe are arranged above the second polishing disc; an ultraviolet lamp is further arranged above the first polishing disc, and a blue light lamp is further arranged above the second polishing disc. According to the wafer photoelectrochemical mechanical planarization device, the ultraviolet lamp is arranged above the first polishing disc, the oxidation efficiency of the wafer is improved through the ultraviolet lamp, rapid removal of the wafer is achieved, the blue light lamp is arranged above the second polishing disc, charges on the surface of the wafer in the electrochemical mechanical polishing process are balanced through the blue light lamp, and the wafer can be rapidly removed. The surface of the wafer is repaired, the surface quality is improved, the polishing efficiency of the wafer is effectively improved through combination of ultraviolet light and blue light, the damage probability of the wafer is reduced, and the surface machining quality of the wafer is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of wafer processing, and more specifically, relates to a wafer photoelectrochemical mechanical planarization device and method. Background Art

[0002] With the continuous advancement of science and technology, the application fields of semiconductor devices are constantly expanding, especially in high-end fields such as smart grids, new energy vehicles, 5G communications, aerospace, etc., the performance requirements for semiconductor materials are getting higher and higher. At present, the third-generation semiconductor materials (such as SiC and GaN) meet the needs of semiconductor materials in the above high-end fields because of their higher bandgap width and excellent physical properties. The technology is progressing rapidly and the products are widely used.

[0003] With the continuous advancement of semiconductor manufacturing technology, the quality and performance requirements of semiconductor materials are getting higher and higher, which means that higher requirements are placed on the surface quality of third-generation semiconductor materials. However, SiC and GaN crystals themselves have the characteristics of high hardness, high brittleness, and strong chemical inertness, which makes the material processing very difficult. Traditional chemical mechanical planarization (CMP) can no longer meet the processing requirements of the above wafers. Any tiny surface defects may affect the growth quality of its epitaxial layer, and then affect the performance of the device and the surface processing quality of the wafer.

[0004] In the existing technology, the electrochemical mechanical polishing (ECMP) method has emerged, which can improve the CMP performance of compound semiconductors by enhancing the chemical reaction in CMP. Electrochemical mechanical polishing (ECMP) adds electrochemical design to CMP, using electrochemical reactions in the electrolyte to remove the wafer surface. This method can effectively improve the polishing rate of CMP, but under the action of dynamic electrochemistry, the polishing efficiency is greatly affected by other factors and is not stable enough. Since the charge distribution on the wafer surface is closely related to the state of the wafer surface, this makes it impossible to guarantee the surface shape control of the wafer after ECMP. Summary of the invention

[0005] The object of the present invention is to provide a wafer photoelectrochemical mechanical planarization device and method, which can improve the polishing efficiency of the wafer and improve the surface quality of the wafer surface.

[0006] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: to provide a wafer photoelectrochemical mechanical flattening device, comprising a processing platform and a first polishing disc and a second polishing disc respectively rotatably connected to the processing platform, a first polishing head and a first polishing liquid nozzle are arranged above the first polishing disc, and a second polishing head and a second polishing liquid nozzle are arranged above the second polishing disc; Among them, an ultraviolet lamp is also provided above the first polishing plate, which is used to emit ultraviolet light to the wafer to oxidize the wafer surface; a blue light lamp is also provided above the second polishing plate, which is used to emit blue light to the wafer to balance the surface charge of the wafer and repair the surface of the wafer.

[0007] In a possible implementation, the wavelength of the UV lamp is 200-350 nm, and the energy density of the UV lamp is 100-400 μW / cm 2 The irradiation frequency of the ultraviolet lamp is 1-3kHz, the wavelength of the blue light lamp is 350-500nm, and the energy density of the blue light lamp is 100-300μW / cm 2 , the irradiation frequency of the blue light is 1-2kHz.

[0008] In some embodiments, a first carrier disposed adjacent to the first polishing disk and a second carrier disposed adjacent to the second polishing disk are provided on the processing platform. The first carrier is used to support the wafer for the first polishing head to absorb, and the second carrier is used to support the wafer unloaded by the second polishing head. An intermediate transfer platform is also provided on the processing platform between the first polishing disk and the second polishing disk. The intermediate transfer platform is used to support the wafer unloaded by the first polishing head for the second polishing head to absorb.

[0009] In some embodiments, the first carrier and the second carrier are arranged near the same side edge of the processing platform. A storage platform is also provided on the outside of the processing platform. The storage platform is provided with a storage tank for placing wafers. The storage platform is provided with a first transfer arm for transferring wafers.

[0010] In a possible implementation, two dressers are further provided on the processing platform, and the two dressers are respectively arranged corresponding to the first polishing disc and the second polishing disc. The first polishing disc and the second polishing disc are both provided with polishing pads, and the dressers are used to clean the polishing pads of the first polishing disc or the second polishing disc.

[0011] In a possible implementation, the wafer photoelectrochemical mechanical planarization device also includes a feeding platform, on which a wafer box and a second transfer arm are provided. The wafer box is used to accommodate wafers, and the second transfer arm is used to absorb and transfer the wafers in the wafer box.

[0012] Compared with the prior art, the solution shown in the embodiment of the present application is that an ultraviolet lamp is arranged above the first polishing plate, and the ultraviolet lamp is used to improve the oxidation efficiency of the wafer and realize rapid removal of the wafer. A blue light lamp is arranged above the second polishing plate, and the blue light lamp is used to balance the surface charge of the wafer during electrochemical mechanical polishing, thereby repairing the surface of the wafer and helping to improve the surface quality. The combination of ultraviolet light and blue light effectively improves the polishing efficiency of the wafer, reduces the probability of wafer damage, and improves the surface processing quality of the wafer.

[0013] The present invention also provides a wafer photoelectrochemical mechanical planarization method, comprising the following steps: S100: The first polishing head absorbs the wafer and drives the wafer to move above the first polishing plate, performs electrochemical mechanical polishing on the wafer, and simultaneously irradiates the wafer with ultraviolet light to increase the oxidation rate of the wafer; S200: The first polishing head unloads the wafer, and the second polishing head absorbs the wafer and drives the wafer to move above the second polishing plate, and performs electrochemical mechanical polishing on the wafer, and at the same time, uses blue light to irradiate the wafer to balance the surface charge of the wafer to repair the surface of the wafer; S300: The second polishing head unloads the wafer and transports the wafer to a storage tank.

[0014] In one possible implementation, in steps S100 and S200, the rotation speed of the first polishing disk and the second polishing disk are both 30-150rpm, the main polishing pressure of the first polishing disk and the second polishing disk is 0.5-5.5psi, the polishing time of the first polishing disk and the second polishing disk is both 5-30min, the flow rate of the first polishing liquid nozzle and the second polishing liquid nozzle is both 30-220mL / min, and the rotation speed of the first polishing head and the second polishing head is both 30-130rpm.

[0015] In a possible implementation, in steps S100 and S200, the voltage parameters applied between the first polishing head and the first polishing plate and between the second polishing head and the second polishing plate are 10-50V, the current parameters are 0.5-5A, and the electrolysis time is 5-30min.

[0016] In a possible implementation, before step S100, the process further includes taking out the wafer from the wafer box and transporting the wafer to the first stage for adsorption by the first polishing head.

[0017] The above-mentioned wafer photoelectrochemical mechanical planarization method uses ultraviolet lamps to improve the oxidation efficiency of the wafer, and uses blue light lamps to balance the surface charge of the wafer during the electrochemical mechanical polishing process, thereby repairing the surface of the wafer and helping to improve the surface quality. The combination of ultraviolet light and blue light effectively improves the polishing efficiency of the wafer, reduces the probability of wafer damage, and improves the surface processing quality of the wafer. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0019] Figure 1A schematic diagram of a top view of the structure of a wafer photoelectrochemical mechanical planarization device provided in an embodiment of the present invention; Figure 2 For the embodiment of the present invention Figure 1 A schematic diagram of the main structure of the first polishing disc, the first polishing head, the ultraviolet lamp, and the first polishing liquid nozzle.

[0020] Among them, the reference numerals in the figure are: 1. Processing platform; 11. Dresser; 12. Middle transfer platform; 2. First polishing disc; 21. First polishing head; 22. First polishing liquid nozzle; 23. Ultraviolet lamp; 24. First carrier; 25. Polishing pad; 3. Second polishing disc; 31. Second polishing head; 32. Second polishing liquid nozzle; 33. Blue light lamp; 34. Second carrier; 4. Storage platform; 41. Storage tank; 42. First transfer arm; 43. First transfer platform; 44. Second transfer platform; 45. Third transfer arm; 5. Feeding platform; 51. Wafer box; 52. Second transfer arm; 6. Wafer. DETAILED DESCRIPTION

[0021] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0022] It should be noted that when an element is referred to as being "disposed on" another element, it may be directly on another element or indirectly on another element. It should be understood that the orientation or positional relationship indicated by the terms "length", "width", "upper", "lower", "front", "back", "top", "bottom", "inside", "outside", etc. is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. The terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "several" is two or more, unless otherwise clearly and specifically defined.

[0023] Please also read Figure 1 to Figure 2, the wafer photoelectrochemical mechanical planarization device and method provided by the present invention are now described. The wafer photoelectrochemical mechanical planarization device comprises a processing platform 1 and a first polishing disc 2 and a second polishing disc 3 respectively rotatably connected to the processing platform 1, a first polishing head 21 and a first polishing liquid nozzle 22 are arranged above the first polishing disc 2, and a second polishing head 31 and a second polishing liquid nozzle 32 are arranged above the second polishing disc 3; Among them, an ultraviolet lamp 23 is also provided above the first polishing disk 2, and the ultraviolet lamp 23 is used to emit ultraviolet light to the wafer 6 to oxidize the surface of the wafer 6; a blue light lamp 33 is also provided above the second polishing disk 3, and the blue light lamp 33 is used to emit blue light to the wafer 6 to balance the surface charge of the wafer 6 and repair the surface of the wafer 6.

[0024] Compared with the prior art, the wafer photoelectrochemical mechanical planarization device provided in this embodiment has an ultraviolet lamp 23 arranged above the first polishing disk 2, and the ultraviolet lamp 23 is used to improve the oxidation efficiency of the wafer 6 to achieve rapid removal of the wafer 6. A blue light lamp 33 is arranged above the second polishing disk 3, and the blue light lamp 33 is used to balance the surface charge of the wafer 6 during the electrochemical mechanical polishing process, thereby repairing the surface of the wafer 6 and helping to improve the surface quality. The combination of ultraviolet light and blue light effectively improves the polishing efficiency of the wafer 6, reduces the probability of damage to the wafer 6, and improves the surface processing quality of the wafer 6.

[0025] In this embodiment, the ultraviolet lamp 23 is separately arranged on the first polishing plate 2, and the blue light lamp 33 is separately arranged on the second polishing plate 3, forming two independent modules, which do not interfere with each other and are independent of each other. The first polishing plate 2 and the second polishing plate 3 can process the same wafer 6 in sequence in different time periods, or process two different wafers 6 separately in the same time period, so that the wafer 6 can be quickly polished first and then effectively repaired, which not only improves the polishing efficiency of the wafer 6, but also ensures the surface processing quality of the wafer 6.

[0026] In one possible implementation, see Figure 1 to Figure 2 The wavelength of the ultraviolet lamp 23 is 200-350nm, and the energy density of the ultraviolet lamp 23 is 100-400μW / cm 2 The irradiation frequency of the ultraviolet lamp 23 is 1-3kHz, the wavelength of the blue light lamp 33 is 350-500nm, and the energy density of the blue light lamp 33 is 100-300μW / cm 2 , the irradiation frequency of the blue light lamp 33 is 1-2kHz.

[0027] In this embodiment, the oxidation and repair of the wafer 6 are achieved by adjusting the wavelength and intensity of the ultraviolet lamp 23 and the blue light lamp 33, and the device has high flexibility and strong adjustability. The above-mentioned ultraviolet lamp 23 and the blue light lamp 33 respectively use the above-mentioned parameter values. When the wafer 6 is polished on the first polishing plate 2, under the action of ultraviolet light, the oxidation efficiency of the wafer 6 in the electrochemical mechanical polishing process can be accelerated, and the wafer 6 can be quickly removed, which helps to improve the polishing speed of the wafer 6. Afterwards, the wafer 6 is transferred to the second polishing plate 3. Under the irradiation of blue light, the blue light with a longer wavelength balances the charge on the surface of the wafer 6 in the electrochemical process, thereby improving the surface morphology of the wafer 6 and improving the polishing quality of the wafer 6.

[0028] The selection of the above parameters meets the polishing and correction requirements of wafer 6, and avoids the loss caused by excessive parameter settings. It can effectively improve the processing efficiency of wafer 6, reduce the probability of damage to wafer 6, and improve the surface quality of wafer 6. It has a good prospect in the semiconductor polishing process.

[0029] Taking the first polishing disc 2 as an example, a cathode plate is provided on the top of the first polishing disc 2, and the cathode plate is located below the polishing pad 25, and the cathode plate is connected to the negative electrode of the power supply. The first polishing liquid nozzle 22 is located above the polishing pad 25, and can spray the polishing liquid onto the polishing pad 25. The first polishing head 21 is connected to the positive electrode of the power supply, and an electric field can be formed between the polishing head and the polishing disc to form an electrochemical effect on the wafer 6.

[0030] The polishing pad 25 is a polyurethane material component, and has a hollow structure, so that the polishing pad 25 forms holes for the polishing liquid to pass through. The polishing liquid can be cerium dioxide polishing liquid, silicon dioxide polishing liquid or titanium dioxide polishing liquid.

[0031] The first polishing liquid nozzle 22 can not only provide the polishing liquid required by the wafer 6, but also provide deionized water. When the wafer 6 needs to be polished, the first polishing liquid nozzle 22 sprays the polishing liquid; when the wafer 6 needs to be cleaned, the first polishing liquid nozzle 22 sprays deionized water to meet the needs of different states of the wafer 6. The structure of the second polishing plate 3 is the same as that of the first polishing plate 2, and will not be repeated here.

[0032] Furthermore, the rotational speed of the first polishing disc 2 and the second polishing disc 3 is 30-150rpm, the main polishing pressure of the first polishing disc 2 and the second polishing disc 3 is 0.5-5.5psi, the polishing time of the first polishing disc 2 and the second polishing disc 3 is 5-30min, the flow rate of the first polishing liquid nozzle 22 and the second polishing liquid nozzle 32 is 30-220mL / min, and the rotational speed of the first polishing head 21 and the second polishing head 31 is 30-130rpm.

[0033] In this embodiment, while using ultraviolet light and blue light, the main polishing pressure set by the first polishing disc 2 and the second polishing disc 3 is lower than the polishing pressure of the conventional chemical mechanical polishing, which can effectively reduce the damage to the wafer 6 and help improve the polishing quality of the wafer 6. The selection of the above parameter values ​​effectively ensures the smooth progress of the polishing process of the wafer 6.

[0034] In some embodiments, the processing platform 1 is provided with a first carrier 24 arranged adjacent to the first polishing disk 2 and a second carrier 34 arranged adjacent to the second polishing disk 3. The first carrier 24 is used to support the wafer 6 for the first polishing head 21 to absorb, and the second carrier 34 is used to support the wafer 6 unloaded by the second polishing head 31. The processing platform 1 is also provided with an intermediate transfer platform 12 located between the first polishing disk 2 and the second polishing disk 3. The intermediate transfer platform 12 is used to support the wafer 6 unloaded by the first polishing head 21 for the second polishing head 31 to absorb.

[0035] In this embodiment, the first stage 24, the second stage 34 and the intermediate stage 12 provided on the processing platform 1 are all used to temporarily support the wafer 6. The wafer 6 is first delivered to the first stage 24 for adsorption by the first polishing head 21 and transferred to the top of the first polishing plate 2 for electrochemical mechanical polishing under the action of the ultraviolet lamp 23.

[0036] After completing the above steps, the first polishing head 21 absorbs and transfers the wafer 6 to the intermediate transfer platform 12, and the wafer 6 is absorbed and transferred to the second polishing plate 3 by the second polishing head 31, and electrochemical mechanical polishing is performed under the action of the blue light 33. After completing the above steps, the second polishing head 31 absorbs and transfers the wafer 6 to the second carrier 34 for other components to be transferred to the next process.

[0037] The combination of the first carrier 24, the second carrier 34 and the intermediate transfer platform 12 can better complete the coordinated work between the first polishing plate 2 and the second polishing plate 3, ensure that there will be no conflict in the transfer of the wafer 6, save the transfer time, and improve the processing efficiency of the wafer 6.

[0038] Specifically, during the process of the second polishing head 31 adsorbing and transferring the wafer 6 to the second carrier 34, the first polishing head 21 will not be affected in loading the wafer from the first carrier 24 to the first polishing disk 2. The above two processes can be carried out simultaneously, thereby shortening the idle time of the first polishing disk 2 and the second polishing disk 3, which helps to improve the polishing efficiency of the wafer 6.

[0039] For some examples, see Figure 1 to Figure 2 The first carrier 24 and the second carrier 34 are arranged near the same side edge of the processing platform 1. A storage platform 4 is also provided on the outside of the processing platform 1. The storage platform 4 is provided with a storage tank 41 for placing the wafer 6. The storage platform 4 is provided with a first transfer arm 42 for transferring the wafer 6.

[0040] In one possible implementation, see Figure 1 to Figure 2 Two dressers 11 are also provided on the processing platform 1. The two dressers 11 are respectively arranged in one-to-one correspondence with the first polishing disc 2 and the second polishing disc 3. The first polishing disc 2 and the second polishing disc 3 are both provided with a polishing pad 25. The dressers 11 are used to clean the polishing pad 25 of the first polishing disc 2 or the second polishing disc 3.

[0041] In this embodiment, the first polishing disc 2 is used as an example for explanation. The dresser 11 can swing horizontally to dynamically sweep and adjust the polishing pad 25 so that the grooves on the polishing pad 25 are not filled, thereby enabling the polishing pad 25 to form a better polishing performance for the wafer 6, thereby meeting the effective polishing of the wafer 6 and helping to improve the polishing efficiency. The dresser 11 corresponding to the second polishing disc 3 has the same function and will not be described in detail here.

[0042] In one possible implementation, see Figure 1 to Figure 2 The wafer photoelectrochemical mechanical planarization device also includes a feeding platform 5, on which a wafer box 51 and a second transfer arm 52 are provided. The wafer box 51 is used to accommodate wafers 6, and the second transfer arm 52 is used to absorb and transfer the wafers 6 in the wafer box 51.

[0043] Based on the same inventive concept, the embodiment of the present application also provides a wafer photoelectrochemical mechanical planarization method, comprising the following steps: S100: The first polishing head 21 absorbs the wafer 6 and drives the wafer 6 to move above the first polishing plate 2, performs electrochemical mechanical polishing on the wafer 6, and irradiates the wafer 6 with ultraviolet light to increase the oxidation rate of the wafer 6; S200: The first polishing head 21 unloads the wafer 6, and the second polishing head 31 absorbs the wafer 6 and drives the wafer 6 to move to the top of the second polishing plate 3, and performs electrochemical mechanical polishing on the wafer 6. At the same time, the wafer 6 is irradiated with blue light to balance the surface charge of the wafer 6 to repair the surface of the wafer 6; S300: The second polishing head 31 unloads the wafer 6 and transports the wafer 6 to the storage tank 41.

[0044] In one possible implementation, see Figure 1 to Figure 2 In steps S100 and S200, the rotation speed of the first polishing disc 2 and the second polishing disc 3 is 30-150rpm, the main polishing pressure of the first polishing disc 2 and the second polishing disc 3 is 0.5-5.5psi, the polishing time of the first polishing disc 2 and the second polishing disc 3 is 5-30min, the flow rate of the first polishing liquid nozzle 22 and the second polishing liquid nozzle 32 is 30-220mL / min, and the rotation speed of the first polishing head 21 and the second polishing head 31 is 30-130rpm.

[0045] In one possible implementation, see Figure 1 to Figure 2 In steps S100 and S200, the voltage parameters applied between the first polishing head 21 and the first polishing disk 2 and between the second polishing head 31 and the second polishing disk 3 are all 10-50V, the current parameters are all 0.5-5A, and the electrolysis time is all 5-30min.

[0046] In one possible implementation, see Figure 1 to Figure 2 Before step S100 , the process further includes taking out the wafer 6 from the wafer box 51 and transporting the wafer 6 to the first stage 24 for adsorption by the first polishing head 21 .

[0047] Embodiment 1: The wafer photoelectrochemical mechanical planarization method comprises the following steps: S100: taking out the wafer 6 from the wafer box 51, conveying the wafer 6 to the first stage 24 for adsorption by the first polishing head 21, the first polishing head 21 adsorbs the wafer 6 and drives the wafer 6 to move above the first polishing plate 2, performing electrochemical mechanical polishing on the wafer 6, and irradiating the wafer 6 with ultraviolet light to increase the oxidation rate of the wafer 6; S200: The first polishing head 21 unloads the wafer 6, the second polishing head 31 absorbs the wafer 6 and drives the wafer 6 to move above the second polishing disk 3, and performs electrochemical mechanical polishing on the wafer 6. At the same time, the wafer 6 is irradiated with blue light to balance the surface charge of the wafer 6 to repair the surface of the wafer 6; the rotation speed of the first polishing disk 2 and the second polishing disk 3 are both 100rpm, the main polishing pressure of the first polishing disk 2 and the second polishing disk 3 is 3.5psi, the polishing time of the first polishing disk 2 and the second polishing disk 3 is both 20min, the flow rate of the first polishing liquid nozzle 22 and the second polishing liquid nozzle 32 are both 150mL / min, and the rotation speed of the first polishing head 21 and the second polishing head 31 are both 80rpm.

[0048] In steps S100 and S200, the voltage parameters applied between the first polishing head 21 and the first polishing plate 2 and between the second polishing head 31 and the second polishing plate 3 are all 30V, the current parameters are all 2.5A, and the electrolysis time is all 25min.

[0049] S300: The second polishing head 31 unloads the wafer 6 and transports the wafer 6 to the storage tank 41.

[0050] Specifically, the wafer box 51 is located on the side of the storage tank 41 away from the processing platform 1. The second transfer arm 52 is first used to take out the wafer 6 from the wafer box 51 and place it on the first transfer platform 43. Then, the first transfer arm 42 transfers the wafer 6 from the first transfer platform 43 to the second transfer platform 44. Then, the third transfer arm 45 transfers the wafer 6 from the second transfer platform 44 to the first carrier 24 for adsorption by the first polishing head 21, so as to carry out subsequent processing of the wafer 6.

[0051] After the wafer 6 is polished on the first polishing plate 2, it is transferred to the intermediate transfer platform 12 through the first polishing head 21, and then adsorbed to the second polishing plate 3 through the second polishing head 31. After further polishing, it is transferred to the second carrier 34 through the second polishing head 31, and then the processed wafer 6 is transferred to the storage tank 41 for storage through the first transfer arm 42, realizing dry-in and wet-out. The above design can avoid the transmission conflicts caused by polishing multiple wafers 6 as much as possible, greatly reducing the transmission time of the wafer 6 and improving the overall operation efficiency of the equipment.

[0052] In the actual arrangement process, the components may be arranged according to the above positions, or may be arranged according to other positional relationships to meet the transfer and polishing of the wafer 6 .

[0053] The above-mentioned wafer photoelectrochemical mechanical planarization method uses ultraviolet lamp 23 to improve the oxidation efficiency of wafer 6, and uses blue light lamp 33 to balance the surface charge of wafer 6 during electrochemical mechanical polishing, thereby repairing the surface of wafer 6, which helps to improve the surface quality. Through the combination of ultraviolet light and blue light, the polishing efficiency of wafer 6 is effectively improved, the probability of damage to wafer 6 is reduced, and the surface processing quality of wafer 6 is improved.

[0054] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A wafer photoelectrochemical mechanical planarization device, characterized in that: The invention comprises a processing platform (1), and a first polishing disc (2) and a second polishing disc (3) which are rotatably connected to the processing platform (1), wherein a first polishing head (21) and a first polishing liquid nozzle (22) are arranged above the first polishing disc (2), and a second polishing head (31) and a second polishing liquid nozzle (32) are arranged above the second polishing disc (3); Wherein, an ultraviolet lamp (23) is also provided above the first polishing disc (2), and the ultraviolet lamp (23) is used to emit ultraviolet light to the wafer (6) to oxidize the surface of the wafer (6); and a blue light lamp (33) is also provided above the second polishing disc (3), and the blue light lamp (33) is used to emit blue light to the wafer (6) to balance the surface charge of the wafer (6) and repair the surface of the wafer (6).

2. The wafer photoelectrochemical mechanical planarization device according to claim 1, characterized in that: The wavelength of the ultraviolet lamp (23) is 200-350nm, and the energy density of the ultraviolet lamp (23) is 100-400μW / cm 2 The irradiation frequency of the ultraviolet lamp (23) is 1-3kHz, the wavelength of the blue light lamp (33) is 350-500nm, and the energy density of the blue light lamp (33) is 100-300μW / cm 2 The irradiation frequency of the blue light lamp (33) is 1-2 kHz.

3. The wafer photoelectrochemical mechanical planarization device according to claim 1, characterized in that: The processing platform (1) is provided with a first carrier (24) arranged adjacent to the first polishing disk (2) and a second carrier (34) arranged adjacent to the second polishing disk (3); the first carrier (24) is used to support the wafer (6) for the first polishing head (21) to absorb, and the second carrier (34) is used to support the wafer (6) unloaded by the second polishing head (31); the processing platform (1) is also provided with an intermediate transfer platform (12) located between the first polishing disk (2) and the second polishing disk (3); the intermediate transfer platform (12) is used to support the wafer (6) unloaded by the first polishing head (21) for the second polishing head (31) to absorb.

4. The wafer photoelectrochemical mechanical planarization device according to claim 3, characterized in that: The first carrier (24) and the second carrier (34) are arranged near the same side edge of the processing platform (1), and a storage platform (4) is also arranged on the outer side of the processing platform (1), and a storage tank (41) for placing wafers (6) is provided on the storage platform (4), and a first transfer arm (42) for transferring wafers (6) is provided on the storage platform (4).

5. The wafer photoelectrochemical mechanical planarization device according to claim 1, characterized in that: The processing platform (1) is also provided with two dressers (11), the two dressers (11) are respectively arranged in one-to-one correspondence with the first polishing disc (2) and the second polishing disc (3), the first polishing disc (2) and the second polishing disc (3) are both provided with a polishing pad (25), and the dressers (11) are used to clean the polishing pad (25) of the first polishing disc (2) or the second polishing disc (3).

6. The wafer photoelectrochemical mechanical planarization device according to claim 1, characterized in that: The wafer photoelectrochemical mechanical planarization device also includes a feeding platform (5), on which a wafer box (51) and a second transfer arm (52) are provided, wherein the wafer box (51) is used to accommodate wafers (6), and the second transfer arm (52) is used to absorb and transfer the wafers (6) in the wafer box (51).

7. A method for performing wafer photoelectrochemical mechanical planarization using the wafer photoelectrochemical mechanical planarization device according to any one of claims 1 to 6, characterized in that: The following steps are involved: S100: the first polishing head (21) absorbs the wafer (6) and drives the wafer (6) to move above the first polishing plate (2), performs electrochemical mechanical polishing on the wafer (6), and simultaneously irradiates the wafer (6) with ultraviolet light to increase the oxidation rate of the wafer (6); S200: the first polishing head (21) unloads the wafer (6), the second polishing head (31) absorbs the wafer (6) and drives the wafer (6) to move above the second polishing plate (3), performs electrochemical mechanical polishing on the wafer (6), and simultaneously irradiates the wafer (6) with blue light to balance the surface charge of the wafer (6) so as to repair the surface of the wafer (6); S300: The second polishing head (31) unloads the wafer (6) and transports the wafer (6) to a storage tank (41).

8. The wafer photoelectrochemical mechanical planarization method according to claim 7, characterized in that: In steps S100 and S200, the rotation speeds of the first polishing disc (2) and the second polishing disc (3) are both 30-150 rpm, the main polishing pressures of the first polishing disc (2) and the second polishing disc (3) are both 0.5-5.5 psi, the polishing time of the first polishing disc (2) and the second polishing disc (3) are both 5-30 min, the flow rates of the first polishing liquid nozzle (22) and the second polishing liquid nozzle (32) are both 30-220 mL / min, and the rotation speeds of the first polishing head (21) and the second polishing head (31) are both 30-130 rpm.

9. The wafer photoelectrochemical mechanical planarization method according to claim 7, characterized in that: In steps S100 and S200, the voltage parameters applied between the first polishing head (21) and the first polishing disk (2) and between the second polishing head (31) and the second polishing disk (3) are all 10-50V, the current parameters are all 0.5-5A, and the electrolysis time is all 5-30min.

10. The wafer photoelectrochemical mechanical planarization method according to claim 7, characterized in that: Before step S100, the method further includes taking out a wafer (6) from a wafer box (51), and transporting the wafer (6) to a first carrier (24) for adsorption by the first polishing head (21).

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