A cleaning apparatus and method for a cmp polishing chamber

Abstract

The present application relates to CMP polishing chamber cleaning technical field, propose a kind of for CMP polishing chamber's cleaning device and cleaning method, polishing chamber contains polishing unit, and polishing unit includes wafer loading cup and polishing head.Nozzle is located in polishing chamber, nozzle includes wafer loading cup cleaning nozzle and polishing head cleaning nozzle, respectively for spraying fluid to clean wafer loading cup and polishing head, nozzle sprays fluid is liquid and / or gas and / or gas-liquid mixture.Through the above technical scheme, the problem that CMP polishing chamber cleaning device in prior art is consumed much and cleaning effect is not obvious to clean cleaning liquid is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of cleaning CMP polishing chambers, in particular, to a cleaning device and method for CMP polishing chambers. BACKGROUND

[0002] CMP (Chemical Mechanical Polishing) can be used to manufacture planarization components in the process of manufacturing semiconductor devices. It uses a large amount of polishing liquid while mechanically polishing, and is a combination of mechanical grinding and chemical corrosion. It forms a smooth plane on the surface of the medium being ground by means of ultra-micro ion grinding and chemical corrosion of the polishing liquid.

[0003] A large amount of polishing liquid is used in CMP, which is a chemical solution, also known as slurry. During the polishing process, the polishing liquid will be splashed onto various modules in the chamber, such as the wafer loading cup, the polishing head, the trimmer, etc. If the splashed polishing liquid is not treated for a long time, it will accumulate, dry and form crystals on the surface of the components, and then move to the polishing pad with the components, and the crystals will fall off onto the polishing pad, causing the risk of scratching the wafer.

[0004] In some processes, a polishing liquid with high viscosity is used. If the polishing liquid splashed onto the surface of the wafer loading cup is not cleaned in time, it will remain on the surface of the carrier. After the wafer is polished and placed on the carrier, it will form defects of polishing liquid residues. The process of transferring the wafer from the polishing unit to the subsequent cleaning unit also takes time, during which the surface of the wafer is exposed and some reactions may occur, causing the viscosity of the polishing liquid residues to increase further, which cannot be completely removed in the subsequent cleaning process.

[0005] Therefore, the existing CMP station is provided with an automatic cleaning device. However, the existing cleaning device has many defects, for example: 1. The cleaning is generally regular cleaning at intervals, which relatively easily causes the residual polishing liquid to form crystals. After the polishing liquid forms crystals, the cleaning is difficult, and a more powerful contact cleaning is required. The cleaning is not necessarily clean, and scratches are easily caused on the surface of the parts in the polishing chamber; 2. The cleaning area is not accurate, and blind cleaning of a large area will waste a lot of cleaning liquid (generally water, deionized water, acid solution, alkali solution or a combination thereof). The cleaning is generally in a mechanical contact mode and a cleaning liquid flushing mode, a lot of cleaning liquid is consumed, and the cleaning effect is not improved; 3. Many derived problems such as water entering the main shaft (a polishing disc rotating shaft or a connecting shaft of a pneumatic assembly and a polishing head) are caused; 4. Liquid drops are easily formed on the surface of each part in the polishing chamber after cleaning. The liquid drops drop on the wafer loading cup or the polishing disc, dirt is easily formed, and the wafer is easily contacted and left on the wafer surface, thereby increasing the difficulty of cleaning the wafer.

[0006] Therefore, there is an urgent need for a CMP polishing chamber cleaning device which is capable of saving cleaning liquid, reducing the generation of cleaning sewage, having good cleaning effect and no liquid drop residue. SUMMARY

[0007] In order to solve the above problems, embodiments of the present application provide a cleaning device and a cleaning method for a CMP polishing chamber, which solve the problems of the CMP polishing chamber cleaning device in the prior art that consumes a lot of cleaning liquid and has no obvious cleaning effect.

[0008] According to an aspect of the present application, a cleaning device for a CMP polishing chamber is provided, the polishing chamber containing a polishing unit, the polishing unit including a wafer loading cup and a polishing head.

[0009] The cleaning device includes:

[0010] A nozzle is located in the polishing chamber, the nozzle including a wafer loading cup cleaning nozzle and a polishing head cleaning nozzle, which are respectively used to spray fluid to clean the wafer loading cup and the polishing head. The fluid sprayed by the nozzle is a liquid and / or a gas and / or a gas-liquid mixture.

[0011] In some embodiments, the polishing head has an upper surface and a side surface; the polishing head cleaning nozzle includes a first nozzle and a second nozzle, the first nozzle and the second nozzle are both located on one side of the polishing head, the first nozzle is used to clean the upper surface, and the second nozzle is used to clean the side surface.

[0012] In some embodiments, the first nozzle is used to spray fan-shaped fluid; and the second nozzle is used to spray cone-shaped fluid.

[0013] In some embodiments, the wafer boat cleaning nozzle comprises a fourth nozzle disposed on one side of the wafer boat, the fourth nozzle configured to clean the top surface of the wafer boat.

[0014] In some embodiments, the nozzle is configured to sequentially spray a gas-liquid mixture, a liquid, and a gas.

[0015] In some embodiments, the ratio of the gas and the liquid in the gas-liquid mixture sprayed by the nozzle is adjustable.

[0016] In some embodiments, the cleaning device for a CMP polishing chamber further comprises a main body disposed in the polishing chamber, the main body having a fluid channel with a fluid outlet and a fluid inlet, the nozzle being disposed on the main body, the inlet of the nozzle being in communication with the fluid outlet.

[0017] In some embodiments, the fluid inlet comprises a liquid inlet and a gas inlet, the liquid inlet being configured to be in communication with a liquid source, and the gas inlet being configured to be in communication with a gas source, a flow valve being disposed between the liquid inlet and the liquid source, and between the gas inlet and the gas source.

[0018] According to another aspect of the present application, a cleaning method for a CMP polishing chamber is also provided, using the cleaning device, the cleaning method comprising the following steps:

[0019] S1: controlling the nozzle to spray a fluid to clean the surface of the polishing unit;

[0020] S2: transferring a wafer to a wafer boat in the polishing chamber;

[0021] S3: a polishing head picks up the wafer and moves the wafer to a polishing pad to perform chemical mechanical polishing, during the process of the polishing head picking up the wafer and moving the wafer to the polishing pad and / or during the process of chemical mechanical polishing of the wafer, the wafer boat cleaning nozzle sprays a fluid to clean the surface of the wafer boat;

[0022] S4: the wafer boat cleaning nozzle stops cleaning the wafer boat, the chemical mechanical polishing of the wafer is completed, the polishing head carrying the wafer moves to the wafer boat, and at the same time, the polishing head cleaning nozzle sprays a fluid to clean the surface of the polishing head;

[0023] S5: transferring the wafer out of the polishing chamber, and the polishing head cleaning nozzle sprays a fluid to clean the surface of the polishing head;

[0024] S6: repeating S2-S5.

[0025] In some embodiments, the nozzle first sprays a gas-liquid mixture, then sprays liquid, and finally sprays gas.

[0026] In some embodiments, a plurality of the main bodies are arranged around the polishing head, and the polishing head is cleaned according to any one of the following steps:

[0027] A1: simultaneously opening the polishing head cleaning nozzles on the plurality of main bodies around the polishing head to clean the polishing head;

[0028] A2: sequentially opening the polishing head cleaning nozzles on the main bodies along the circumference of the polishing head to clean the polishing head until the polishing head cleaning nozzles on all the main bodies are opened;

[0029] A3: opening the polishing head cleaning nozzle on one of the main bodies to clean the polishing head, closing the polishing head cleaning nozzle after cleaning for a time a, opening the polishing head cleaning nozzle on another main body adjacent in the rotation direction or the opposite direction of the polishing head to clean the polishing head, closing the polishing head cleaning nozzle after cleaning for a time b, and sequentially repeating and cycling.

[0030] Any sequential combination of A1, A2, and A3.

[0031] In some embodiments, in step A3, a = b.

[0032] In some embodiments, in step A3, the polishing head cleaning nozzles on the plurality of main bodies are sequentially opened to clean the same area of the polishing head when the polishing head rotates.

[0033] In some embodiments, if the rotation speed of the polishing head is constant, then a = b; if the rotation speed of the polishing head increases, then a < b; and if the rotation speed of the polishing head decreases, then a > b.

[0034] According to the above technical solution, the present application has the following advantages:

[0035] (1) The wafer loading cup and the polishing head surface are finely cleaned, the cleanliness near the wafer is improved, the risk of scratching or staining the wafer surface is reduced, the cost performance of the cleaning liquid is improved, and the problems such as spindle water ingress caused by blind cleaning can be avoided.

[0036] The wafer loading cup and the polishing head are key components in direct contact with the wafer. The nozzle can be used to clean the surface of the wafer loading cup and the surface of the polishing head in a short period of time. The short period of time can be once after contacting the wafer, or twice after contacting the wafer, etc. This greatly shortens the period of time. Even if there is polishing liquid residue, it will not appear crystallization and other difficult-to-clean substances. After the flushing of the nozzle, it is very easy to clean, which improves the cleanliness near the wafer in the polishing chamber, and does not consume more cleaning liquid, because it is more targeted, which can greatly avoid the problem of spindle water ingress and other derivative problems.

[0037] (2) The specific sequence of the nozzle spraying fluid is gas-liquid mixture, then liquid, and finally gas, which improves the cleaning effect and efficiency and reduces the consumption of cleaning liquid and the amount of cleaning sewage.

[0038] The gas-liquid mixture can use the impact and stirring of the gas and the dissolving and penetrating ability of the liquid to preliminarily decompose and strip various dirt on the surface, creating favorable conditions for the subsequent cleaning steps. After the action of the gas-liquid mixture, although part of the dirt on the surface has been removed, some small particles, impurities dissolved in the liquid, and stains left by gas bubbles may still remain. At this time, the sprayed liquid can completely flush away these residual dirt and stains by virtue of its large flow rate and good fluidity, ensuring that the cleanliness of the surface reaches a higher level. The last gas sprayed can quickly blow off the liquid droplets on the surface to prevent water stains from forming. This sequence setting forms a logically rigorous and interlocking system for the cleaning process, which can comprehensively and efficiently clean various common contaminants on the surface of the CMP chamber, significantly improving the cleanliness. Because the gas-liquid mixture increases the amount of gas, it can also reduce the consumption of cleaning liquid and the amount of sewage after cleaning. BRIEF DESCRIPTION OF DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the description of the embodiments of the present application. Obviously, the drawings in the following description are only some example embodiments of the present application. For those skilled in the art, other drawings can be obtained according to the contents of the example embodiments of the present application and these drawings without paying any creative labor.

[0040] Figure 1 is a top view schematic diagram of the CMP polishing chamber in the present application;

[0041] Figure 2 is another top view schematic diagram of the CMP polishing chamber in the present application, which shows the cleaning device;

[0042] Figure 3 is a schematic diagram of the structure of the polishing head in the present application;

[0043] Figure 4 The schematic diagram of the wafer loading cup part structure in the application;

[0044] Figure 5 The schematic diagram of the main body part structure of the cleaning device in the application;

[0045] Figure 6 The schematic diagram of the fluid delivery principle structure of the cleaning device in the application;

[0046] Figure 7 The schematic diagram of the double-branch channel cross-section structure of the main body in the application;

[0047] Figure 8 The schematic diagram of the branch channel one cross-section structure of the main body in the application;

[0048] Figure 9 The schematic diagram of the branch channel two cross-section structure of the main body in the application;

[0049] Figure 10 The schematic diagram of the adjusting valve structure when the fluid channel is opened in the application;

[0050] Figure 11 The schematic diagram of the adjusting valve structure when the fluid channel is closed in the application;

[0051] Figure 12 The schematic diagram of the adjusting valve limit surface structure in the application;

[0052] Figure 13 The schematic diagram of the cleaning process in the application.

[0053] In the figure: 1-polishing chamber, 2-polishing unit, 21-wafer loading cup, 22-polishing head, 221-upper surface, 222-side surface, 23-pneumatic assembly, 231-lower surface, 24-polishing disc, 25-trimming device, 26-liquid supply arm, 3-surface, 41-nozzle, 411-first nozzle, 412-second nozzle, 413-third nozzle, 414-fourth nozzle, 42-main body, 43-fluid channel, 431-fluid outlet, 432-fluid inlet, 433-liquid inlet, 434-gas inlet, 435-flow valve, 436-branch channel one, 437-branch channel two, 438-adjusting valve, 439-limit surface, 440-mounting hole, 441-reserved hole. DETAILED DESCRIPTION

[0054] The application will be further described below in conjunction with the drawings and examples. It can be understood that the specific examples described herein are only used to explain the application, and not to limit the application.

[0055] For the purpose of clarity, only the parts of the apparatus that are pertinent to the invention are shown in the drawings, and they do not necessarily represent the actual configuration of the product. In addition, in some of the drawings, only one of the components with the same structure or function is shown schematically, or only one of them is labeled, in order to make the drawings simple and easy to understand. In this document, "one" means not only "only one", but also "more than one", and "several" includes "two" and "more than two".

[0056] In this document, unless otherwise explicitly specified and limited, the terms "mount", "connect", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be direct connection, or indirect connection through intermediate medium; it can be internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present invention can be understood according to the specific circumstances.

[0057] In the present invention, unless otherwise explicitly specified and limited, "on" or "under" of the first feature to the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, "on", "above" and "over" of the first feature to the second feature includes that the first feature is directly above and obliquely above the second feature, or only means that the horizontal height of the first feature is higher than that of the second feature. "Under", "below" and "under" of the first feature to the second feature includes that the first feature is directly below and obliquely below the second feature, or only means that the horizontal height of the first feature is less than that of the second feature.

[0058] In the description of the present embodiment, the terms "up", "down", "left", "right" and other orientation or position relationships are based on the orientation or position relationships shown in the drawings, and are only for the convenience of description and simplification of operation, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present invention.

[0059] In addition, in the description of the present application, the terms "first", "second" and the like are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0060] Reference Figure 1Fig. 1 shows a CMP polishing chamber 1 in which only one polishing unit 2 is shown. It is understood that there can be multiple polishing units 2 in the CMP polishing chamber 1, and multiple wafers are polished simultaneously. Here, polishing generally refers to chemical mechanical polishing. Each polishing unit 2 has a polishing disk 24, a trimmer 25, a polishing head 22, and a wafer loading cup 21. The polishing head 22 takes a wafer from the wafer loading cup 21 by suction or mechanical clamping, and presses the wafer against a polishing pad on the polishing disk 24 under pressure, while a polishing liquid is supplied, and the rotating polishing disk 24 performs a mechanical chemical polishing process on the wafer. Optionally, the polishing chamber 1 is a relatively closed area for limiting the influence of external contaminants on the CMP process, and preventing the chemical polishing liquid in the CMP process from splashing outside. The wafer on the wafer loading cup 21 is moved to subsequent process equipment by a robot or a manipulator.

[0061] According to an embodiment of the present application, in order to clean the polishing liquid in time, an embodiment of the present application provides a cleaning device for a CMP polishing chamber. Referring to Fig. 1, Figure 2 , Figure 2 Fig. 2 is another top view of the CMP polishing chamber in the present application, in which the cleaning device is shown. The polishing chamber 1 is provided with a surface 3, a nozzle 41, and a polishing unit 2. The polishing unit 2 includes a wafer loading cup 21, a polishing disk 24, a polishing pad, and a polishing head 22. The surface 3 includes the inner surface of the polishing chamber 1 and / or the surface of the wafer loading cup 21 and / or the surface of the polishing disk 24 and / or the surface of the polishing head 22 and / or the surface of the polishing pad. The nozzle 41 is located in the polishing chamber 1, and the nozzle 41 is used to spray fluid to clean the surface 3. The fluid sprayed by the nozzle 41 is a liquid and / or a gas and / or a gas-liquid mixture.

[0062] In this embodiment, the polishing disk 24 is located on one side of the wafer loading cup 21, and the polishing head 22 is movably arranged between the polishing disk and the wafer loading cup 21, and is used to transfer the wafer between the wafer loading cup 21 and the polishing disk 24 by suction. Alternatively, the polishing head 22 clamps the wafer between the wafer loading cup 21 and the polishing disk by mechanical clamping. The polishing pad is located on the polishing disk 24, and the polishing of the wafer is completed by the polishing pad. The nozzle 41 can spray fluid to flush the surface 3, prevent the polishing liquid from remaining on the surface 3, and accumulate to form crystals, thereby providing a clean environment for wafer processing and preventing the wafer from being scratched.

[0063] According to an embodiment of the present application, the nozzle 41 includes a wafer loading cup cleaning nozzle for cleaning the surface of the wafer loading cup 21, and a polishing head cleaning nozzle for cleaning the surface of the polishing head 22.

[0064] In this embodiment, it is extremely important to use the nozzle 41 to clean the surfaces of the wafer loading cup 21 and the polishing head 22. The wafer loading cup 21 bears the heavy responsibility of carrying and transferring wafers throughout the CMP process, and any slight contamination on its surface can be transferred to the wafer during wafer placement and transfer, causing problems such as scratches and impurity adsorption on the wafer surface, thereby seriously affecting the flatness, smoothness of the wafer, and subsequent chip manufacturing processes. The polishing head 22 is a component that directly contacts and applies pressure to the wafer to achieve polishing action, and the cleanliness of its surface plays a decisive role in pressure uniformity and polishing effect. If there is dirt or uneven distribution of residual polishing liquid on the surface of the polishing head 22, the wafer will receive inconsistent pressure during polishing, causing local overpolishing or underpolishing, ultimately reducing the yield of the wafer. Therefore, targeted cleaning of these two key surfaces can accurately eliminate contamination sources that may affect the precision of the CMP process and the quality of the wafer, greatly improving the stability and reliability of the process.

[0065] In addition, because the wafer loading cup 21 and the polishing head 22 are key components that directly contact the wafer, the nozzle 41 will specifically clean the surface of the wafer loading cup 21 and the surface of the polishing head 22 within a short period, which can be after contacting the wafer once, or after contacting the wafer twice, etc. This greatly shortens the period, and even if there is residual polishing liquid, it will not form difficult-to-clean substances such as crystals, and it can be easily cleaned by the nozzle 41. Because the surface to be cleaned is smaller and more targeted relative to the entire interior of the polishing chamber 1, even if the cleaning period is short, it will not consume too much cleaning liquid, and it is difficult to cause problems such as spindle water ingress. After a long period (determined according to the actual polishing liquid residual formation time inside the polishing chamber 1), the entire polishing chamber 1 can be thoroughly cleaned, which can reduce the risk of scratching the wafer and the probability of contaminating the wafer surface with dirt while consuming almost the same amount of cleaning liquid.

[0066] Further, the wafer boat cleaning nozzle and the polishing head cleaning nozzle are controlled to be flushed asynchronously or synchronously. Usually, a typical wafer polishing process is as follows: the polishing head picks up a wafer from the wafer boat 21, the polishing head carries the wafer to polish, after polishing, the polishing head puts the wafer back to the wafer boat, the robot takes the wafer from the wafer boat and transfers it to the subsequent process equipment. In this polishing process, the time required is long. Especially when the polishing head carries the wafer to polish, the wafer boat is in an idle waiting state. If there is slurry remaining on the wafer boat, it will solidify, dry and form crystals, and then move to the polishing pad, the crystals will fall off onto the polishing pad, causing the risk of scratching the wafer. Therefore, it is desirable to independently clean the wafer boat 21 while the polishing head carries the wafer to polish, instead of waiting until the end of the entire polishing process. Similarly, it is desirable to immediately independently clean the polishing head after the polishing head puts the wafer back to the wafer boat.

[0067] Therefore, the nozzle 41 includes a wafer boat cleaning nozzle for cleaning the surface of the wafer boat 21 and a polishing head cleaning nozzle for cleaning the surface of the polishing head 22, so that the wafer boat and the polishing head can be cleaned asynchronously, the cleaning period is greatly shortened, even if there is slurry remaining, there will be no difficult-to-clean substances such as crystals, and it is easy to clean after flushing by the nozzle 41.

[0068] The polishing head 22 has an upper surface 221 and a side surface 222. Optionally, the polishing head cleaning nozzle includes a first nozzle 411 and a second nozzle 412, both of which are located on one side of the polishing head 22, the first nozzle 411 is used to clean the upper surface 221, and the second nozzle 412 is used to clean the side surface 222.

[0069] In this embodiment, the surface of the polishing head 22 is further subdivided into the upper surface 221 and the side surface 222, and the first nozzle 411 and the second nozzle 412 are configured to correspond to cleaning, respectively. This design embodies the concept of fine cleaning. The upper surface 221 of the polishing head 22 is an area where sputtering slurry is easy to remain, and it is easy to form slurry crystals. The first nozzle 411 is specially used to clean the upper surface 221 area, which can greatly reduce the risk of slurry remaining to form crystals and falling onto the polishing pad 24 or the wafer boat 21 to scratch the wafer. The first nozzle 411 sprays a fan-shaped fluid, which can uniformly spread the cleaning medium on the upper surface with a large coverage area, ensuring that every part of the upper surface can be fully cleaned, effectively removing possible small particles, residual chemicals, etc.

[0070] The side surface of the polishing head 22 is not only easy to retain the sputtered polishing liquid, but also easy to form a high concentration of polishing liquid droplets after the polishing liquid gathers on the side surface, and then the polishing liquid droplets drop onto the wafer loading cup 21 or the polishing disc 24. Especially after dropping onto the wafer loading cup 21, the wafer is placed on the wafer loading cup 21, and the high concentration of polishing liquid droplets is easy to contaminate the wafer surface, increasing the difficulty of the wafer in the subsequent cleaning. The second nozzle 412 is lower than the first nozzle 411, and is used to clean the side surface of the polishing head 22. The fluid sprayed by the second nozzle 412 is in a conical shape.

[0071] In this embodiment, as shown in Figure 2 and Figure 3 The design of the fan-shaped fluid sprayed by the first nozzle 411 is ingenious and adapts to the cleaning needs of the upper surface of the polishing head. The fan-shaped fluid can form a wide coverage area in the horizontal direction when sprayed, similar to the shape of a fan unfolded, so that the cleaning fluid can cover a large area of the upper surface at one time. Such large-area coverage not only improves the cleaning efficiency and reduces the cleaning time, but also ensures the uniformity of the cleaning process. During the cleaning process, the fan-shaped fluid uniformly impacts the upper surface, so that the cleaning liquid can fully contact and carry away the dirt on the surface, avoiding the problem of residue caused by incomplete local cleaning.

[0072] For the conical fluid sprayed by the second nozzle 412 to clean the side surface 222, the diameter of the conical fluid at the outlet of the second nozzle 412 is small, and the conical shape of the fluid can make the fluid gradually disperse during movement, and the diameter gradually expands. The relative flow rate will gradually decrease, so the washing intensity will be relatively soft, and it can cover a part of the upper and lower side surfaces 222.

[0073] Optionally, the polishing head cleaning nozzle further comprises a third nozzle 413, and the third nozzle 413 is located on one side of the polishing head 22. The third nozzle 413 is used to clean the lower surface 231 of the pneumatic assembly 23 above the polishing head 22. The fluid sprayed by the third nozzle 413 is in a fan shape.

[0074] In this embodiment, the addition of the third nozzle 413 for cleaning the lower surface 231 of the pneumatic assembly 23 above the polishing head 22 is an important supplement to the overall cleaning system integrity. The pneumatic assembly 23 plays a critical control role in the operation of the polishing head 22, such as providing precise pressure regulation for the polishing head 22, controlling its movement trajectory, etc. The lower surface 231 of the pneumatic assembly 23 is prone to adsorbing dust, oil stains, and other contaminants such as polishing liquid residues that may splash from the polishing head or other components during long-term operation. If these contaminants are not cleaned in time, they will gradually accumulate and may enter the internal precision structure of the pneumatic assembly, causing wear, blockage, or performance degradation of the pneumatic components. For example, dust particles may hinder the normal opening and closing of pneumatic valves, affecting the precise control of gas flow, and ultimately causing instability in the pressure of the polishing head, which can have a serious negative impact on the polishing quality of the wafer. By spraying fan-shaped fluid from the third nozzle 413 to clean the lower surface 231, these potential sources of contamination can be effectively removed, maintaining the good operating state of the pneumatic assembly 23.

[0075] In addition, because the pneumatic assembly 23 is located above the polishing head 22, any residual polishing liquid on the pneumatic assembly 23, whether in the form of droplets or polishing liquid crystals, has the potential to cause scratches on the wafer, which is not conducive to maintaining the cleanliness and smoothness of the wafer surface.

[0076] In this embodiment, referring to Figure 4 , the wafer loading cup cleaning nozzle includes a fourth nozzle 414, which is arranged on one side of the wafer loading cup 21. The fourth nozzle 414 is used to clean the upper surface of the wafer loading cup 21.

[0077] In this embodiment, the fourth nozzle 414 is used to clean the upper surface of the wafer loading cup 21, embodying the concept of refined cleaning. The upper surface of the wafer loading cup 21 is the area where the wafer is directly placed, and its flatness and cleanliness are crucial for the initial positioning and fixation of the wafer. The fourth nozzle 414 sprays fan-shaped fluid, which can uniformly spread the cleaning medium over a large coverage area on the upper surface, ensuring that every part of the upper surface is adequately cleaned, effectively removing any potential small particles, residual chemicals, etc., and providing a clean and stable foundation for the wafer.

[0078] In a further alternative embodiment, the fluid sprayed by the nozzles 41 is at least one of a liquid (i.e. cleaning liquid), a gas and a gas-liquid mixture, giving the device versatile cleaning capabilities. The liquid can take away soluble dirt, residual polishing liquid and small particle impurities by virtue of its fluidity and solubility; the gas can generate impact force when sprayed at high speed, blowing off some loosely adhered contaminants, and can also be used to dry the surface after cleaning, avoiding the problem of incomplete cleaning caused by water stains remaining; the gas-liquid mixture combines the advantages of both, the disturbance of the gas can make the liquid penetrate better into some hard-to-reach gaps and corners, enhancing the cleaning effect, and the gas-liquid mixture, with the addition of gas, improves the cleaning effect while reducing the proportion of cleaning liquid used. Through such overall design, the device can maintain the cleanliness of the surfaces of all components in the polishing chamber 1 in all directions, providing a strong guarantee for high-quality wafer processing.

[0079] Optionally, the nozzles 41 are used to spray the gas-liquid mixture, the liquid and the gas in sequence.

[0080] In this embodiment, the cleaning sequence in which the nozzles 41 spray the gas-liquid mixture, the liquid and the gas in sequence is a carefully designed scientific process.

[0081] The gas-liquid mixture plays an important role in the initial stage of cleaning, and the presence of the gas gives it certain expansibility and disturbance, which can produce a small explosion effect and strong stirring action when it contacts the surface to be cleaned. This effect can loosen and break the dirt layer on the surface, and disperse the particles of impurities that were originally tightly adhered to the surface, while the liquid component can quickly penetrate into the dirt and wrap it up using its solubility and fluidity. For example, for some hard dirt shells formed after the polishing liquid dries, the gas-liquid mixture can effectively break them down into smaller fragments, laying a good foundation for subsequent cleaning steps.

[0082] The liquid sprayed next mainly undertakes the task of overall rinsing, and it can flush away the dirt particles, broken impurities and contaminants dissolved in the liquid that remain after the gas-liquid mixture treatment, ensuring that there is no visible dirt left on the surface, and the sprayed liquid can also clean the gas bubble stains that may be produced by the gas-liquid mixture.

[0083] The gas sprayed out at the end of the cleaning process can blow off the liquid droplets of the cleaning liquid or dry the surface. The high-speed flowing gas can blow off the liquid droplets and avoid the water stains from staying on the surface. In the CMP process environment, the water stains can react with the residual chemicals, causing surface corrosion or water stain marks, affecting the quality of the wafer and the hygiene of the polishing chamber. The sequence setting forms a complete and efficient system for the cleaning process from decontamination, rinsing to blowing off the liquid droplets, which can meet the strict requirements of the CMP chamber for surface cleanliness and provide ideal surface conditions for subsequent polishing process or wafer processing.

[0084] And the gas-liquid mixture can reduce the consumption of cleaning liquid to some extent and improve the cleaning effect because the liquid and gas in the gas-liquid mixture have a certain proportion.

[0085] Optionally, the proportion of the gas and the liquid in the gas-liquid mixture sprayed out by the nozzle 41 is adjustable.

[0086] In this embodiment, the adjustable proportion of the gas and the liquid in the gas-liquid mixture sprayed out by the nozzle 41 brings high flexibility and adaptability to the cleaning process. When facing different pollution conditions, the gas-liquid proportion can be accurately adjusted according to actual needs. For example, when there are a large number of loose particle dirt on the surface of the polishing chamber, such as abrasive dust generated during the polishing process, the proportion of the gas can be appropriately increased. A higher proportion of the gas can generate a stronger airflow impact force when the mixture is sprayed out, like a "strong wind" that can quickly blow these loose particles away from the surface, and the disturbance of the gas also helps the liquid to penetrate into the gaps of the particle accumulation and thoroughly remove it. When the surface is mainly some sticky residual polishing liquid or chemical dirt, the proportion of the liquid needs to be increased. More liquid can dissolve and emulsify the sticky dirt by its dissolving and emulsifying capacity, so that the dirt is separated from the surface and flows away with the liquid. In addition, the gas-liquid proportion can also be adjusted in different cleaning stages. In the pre-cleaning stage at the beginning of the cleaning process, the proportion of the gas can be appropriately increased to quickly loosen the dirt; in the deep cleaning stage, the proportion of the liquid is increased to ensure that the dirt is thoroughly removed. The adjustable proportion feature enables the device to be optimally configured for various complex pollution conditions and cleaning requirements, which not only improves the cleaning effect, but also saves cleaning resources, reduces cleaning costs, and improves the economy and environmental protection of the entire CMP process.

[0087] In one embodiment of the present application, referring to Figure 3 and Figures 5-6 The cleaning device further comprises a plurality of bodies 42, the bodies 42 are arranged in the polishing chamber 1, the bodies 42 have fluid channels 43, the fluid channels 43 have fluid outlets 431 and fluid inlets 432. The nozzles 41 are arranged on the bodies 42, and the inlets of the nozzles 41 are in communication with the fluid outlets 431.

[0088] In this embodiment, the main body 42 and the fluid channel 43 provide stable and efficient guarantee for the fluid supply of the entire cleaning device. The main body 42 serves as the core framework of the device, and the fluid channel 43 inside the main body 42 smoothly delivers the fluid required for cleaning from the source end to each nozzle.

[0089] Optionally, the main body 42 has several, for example, three, four, or six. The several main bodies 42 are located at different positions in the polishing chamber 1 that need to be cleaned, which can meet the cleaning needs of different positions and allow the cleaning fluid to cover a more comprehensive area, thereby improving the cleaning efficiency and cleanliness.

[0090] The plurality of main bodies 42 are evenly arranged around the polishing head 22. When cleaning the polishing head 22, the following steps are performed:

[0091] A1: simultaneously opening the polishing head cleaning nozzles on the plurality of main bodies 42 around the polishing head 22 to clean the polishing head 22; or

[0092] A2: sequentially opening the polishing head cleaning nozzles on each main body 42 along the circumference of the polishing head 22 to clean the polishing head 22 until all the polishing head cleaning nozzles on each main body 42 are opened; or

[0093] A3: first opening the polishing head cleaning nozzle on one of the main bodies 42 to clean the polishing head, closing the polishing head cleaning nozzle after cleaning for a time a, opening the polishing head cleaning nozzle on another main body 42 adjacent in the rotation direction or the opposite direction of the polishing head to clean the polishing head, closing the polishing head cleaning nozzle after cleaning for a time b, and sequentially repeating and cycling. Wherein a and b can be equal, or the values of a and b can be selected according to the cleanliness of different areas of the polishing head obtained by the vision sensor. For example, when the polishing head is still rotating at a speed r, the area with poor cleanliness faces different main bodies 42, and the polishing head cleaning nozzle on the corresponding main body 42 is opened to clean the area. If the rotation speed of the polishing head is constant, then a = b; if the rotation speed of the polishing head increases, then a < b; if the rotation speed of the polishing head decreases, then a > b.

[0094] Steps A1, A2, and A3 can also be used in combination, for example, first using step A1 and then using step A3; or first using step A1 and then using step A2.

[0095] A1This way can be in an instant to the polishing head 22 of the entire surface of all-round cleaning. Multiple nozzles work at the same time, so that the cleaning fluid can be a large area of impact on the polishing head 22 surface, quickly take away the surface of the dirt, residual polishing liquid and wear particles and other pollutants. For example, after the polishing process, a large number of polishing liquid and wafer debris may be attached to the polishing head surface, while opening all the nozzles can be in the shortest time to flush these contaminants from all directions, improve the efficiency of cleaning, reduce the cleaning time, help to improve the production rhythm of the entire CMP process.

[0096] Because it is four around the same time cleaning, the polishing head in all directions by the cleaning force is relatively uniform. It is very important to maintain the shape accuracy and mechanical properties of the polishing head. If the cleaning force is uneven, it may cause local deformation or uneven wear of the polishing head during long-term use. For example, in some high-precision CMP applications, the flatness of the polishing head directly affects the polishing quality of the wafer, and uniform cleaning force can avoid the slight changes in the polishing head surface caused by the cleaning process, thereby ensuring the uniformity and stability of the wafer polishing, and improving the yield of wafer products.

[0097] A2way by opening the nozzle in turn, can be cleaned one by one area of the polishing head 22 and observe the cleaning effect. In the time period of each nozzle opening, the corresponding area of the pollutant removal can be more carefully checked, so as to find the possible cleaning dead angle or difficult to remove dirt accumulation point in time. For example, if the pollutants in a certain area cannot be effectively removed when a particular nozzle is opened, the cleaning parameters of the nozzle can be adjusted, such as fluid pressure, flow or cleaning liquid composition, so as to realize the accurate optimization of the cleaning effect of the entire polishing head. This step-by-step cleaning method is very suitable for some high-quality cleaning requirements, complex polishing head structure or special pollutant properties, which can ensure that every part of the polishing head can be thoroughly cleaned, and improve the cleaning quality and reliability.

[0098] Compared with opening all the nozzles at the same time, opening the nozzles in turn can avoid the instantaneous high flow and high pressure impact caused by a large number of nozzles working at the same time. This relatively mild cleaning method has less pressure on the mechanical structure of the polishing head 22 and the cleaning system and the pipeline system, reducing the risk of equipment damage caused by instantaneous impact. At the same time, since not all nozzles are running at the same time, the energy consumption during cleaning is relatively low, which helps to reduce the operating cost of the CMP process and improve the service life and stability of the equipment.

[0099] A3 This way forms a dynamic, locally circulating cleaning flow field on the polishing head surface. When a nozzle is on, the cleaning fluid forms a specific flow pattern in its action area, which flushes and carries away the contaminants in that area. When switching to the adjacent nozzle after a period of time, the new cleaning flow field interacts with the previous one, so that the contaminants are constantly disturbed, transferred and removed from the polishing head surface. For example, in the case of some sticky polishing liquid residues or fine particles with strong adsorption to the surface, this locally circulating flow field can gradually weaken the adhesion of the contaminants to the polishing head surface through multiple flow field switching and superposition, stripping them from the surface and carrying them away, improving the cleaning ability of stubborn dirt. In addition, for a rotating polishing head, a specific area can be cleaned in a targeted manner; the time periods of a and b can also be adjusted to form a circumferential cleaning in turn.

[0100] Since the nozzles are opened in turn, the working time of each nozzle is relatively short and evenly distributed in the entire cleaning period. This makes the cleaning time and the cleaning effect of each area of the polishing head surface relatively balanced, avoiding uneven wear caused by excessive cleaning of a certain area and insufficient cleaning of other areas. At the same time, if a nozzle fails or is blocked during cleaning, it can be located and handled more easily, because only one nozzle is working at a time, and the failure of multiple nozzles at the same time will not cause chaos in the entire cleaning system. This improves the maintainability and reliability of the cleaning system, reduces the downtime of the CMP process caused by cleaning system failure, and ensures the continuity of production.

[0101] First, the A1 step can use the simultaneous action of all nozzles at the beginning of cleaning to quickly remove most of the loose contaminants on the polishing head surface, quickly start the cleaning process, and improve the initial efficiency of cleaning. Then switch to the A3 step to deeply clean the stubborn dirt that may remain after the A1 method. For example, in the CMP process, there may be large particle impurities that can be easily washed away and dirt that is chemically reacted with the surface and adheres tightly to the surface on the polishing head surface. The A1 step can quickly remove large particles, and the A3 step can gradually remove stubborn chemical contaminants using its locally circulating flow field characteristics. This combination ensures both the speed and thoroughness of cleaning, allowing the polishing head to achieve higher cleanliness standards and meet the quality requirements of high-precision CMP processes for the polishing head surface.

[0102] The instant high-flow cleaning of step A1 is highly efficient but can cause some impact on the equipment. The subsequent step A3 is a relatively mild and cyclic cleaning method that can buffer and protect the equipment. After quickly removing a large amount of contaminants, step A3 can deep clean while gradually adapting the equipment to the cleaning process, reducing the risk of wear and damage to the equipment caused by long-term high-pressure cleaning. This efficient-to-mild deep cleaning strategy, under the premise of ensuring the cleaning effect of the polishing head, prolongs the service life of the cleaning equipment and the polishing head, and improves the operation stability and economy of the entire CMP system.

[0103] The comprehensive simultaneous cleaning of step A1 as a rough cleaning stage can remove visible contaminants on the surface of the polishing head in a large area, covering the entire surface of the polishing head 22, and quickly reducing the overall content of contaminants. Then step A2 is used for fine cleaning, which checks and cleans each area in detail by opening the nozzles one by one. For example, after rough cleaning, there may still be some local dirt residues or areas where the cleaning effect is not ideal, and step A2 can accurately locate and handle these problems to ensure that each area can achieve the best cleaning effect. This combination fully utilizes the efficiency of step A1 and the accuracy of step A2, improves the overall quality and reliability of cleaning, and enables the polishing head to meet the high surface cleanliness requirements of the CMP process, thereby improving the quality and yield of wafer polishing.

[0104] First, step A1 is used for comprehensive cleaning, which can preliminarily judge the amount of resources required for the entire cleaning process, such as the amount of cleaning liquid, cleaning time, etc. based on the cleaning effect. Then, during the fine cleaning of step A2, the cleaning parameters of each area can be adjusted according to the results of the rough cleaning, avoiding waste of resources. For example, if it is found that there are fewer contaminants in a certain area after rough cleaning, the cleaning time of the nozzles in that area or the flow of the cleaning liquid can be appropriately reduced during fine cleaning, thereby improving the utilization efficiency of cleaning resources. At the same time, this comprehensive-to-accurate cleaning process also makes the entire cleaning process more orderly and controllable, facilitating the monitoring and management of the operator, and improving the automation and intelligence level of the cleaning link in the CMP process.

[0105] Optionally, the fluid inlet 432 is divided into a liquid inlet 433 and a gas inlet 434, the liquid inlet 433 is used to communicate with a liquid source, and the gas inlet 434 is used to communicate with a gas source (the gas in the polishing chamber 1 can be used as the gas source, which is recycled and does not increase additional gas consumption, and there is no need to worry about chemical reaction corrosion between the gas and the internal components of the polishing chamber). Flow valves 435 are arranged between the liquid inlet 433 and the liquid source and between the gas inlet 434 and the gas source.

[0106] In this embodiment, as shown in FIG. 4, the polishing chamber 1 is provided with a fluid inlet 432, and the fluid inlet 432 is connected to a fluid source (not shown in the figure) through a fluid inlet pipe 431. Figure 6As shown, the fluid inlet 432 is divided into a liquid inlet 433 and a gas inlet 434, and a flow valve 435 (which can be an electromagnetic valve, a hydraulic valve, or a pneumatic valve, etc.) is arranged. This design brings high precision and intelligent level to the cleaning control of the device. Through the flow valve 435 between the liquid inlet 433 and the liquid source, the liquid flow into the fluid channel 43 can be accurately adjusted. For example, when it is necessary to accurately control the liquid proportion in the gas-liquid mixture, the flow valve 435 can accurately adjust the flow rate and flow of the liquid according to the preset proportion parameters, to ensure that the liquid content in the mixture meets the requirements. Similarly, the flow valve 435 between the gas inlet 434 and the gas source also plays a key role in the control of the gas flow. In some cleaning scenarios that require specific gas pressure or flow, such as using high-pressure gas to impact some difficult-to-remove dirt, the flow valve 435 can accurately adjust the gas flow to the required level. The arrangement of the flow valve 435 enables the device to flexibly adjust the flow of liquid and gas according to different cleaning process requirements, contamination levels, and surface materials, etc. The operator can remotely or locally adjust the opening of the flow valve 435 through a preset program or according to the real-time monitoring of the cleaning effect feedback, to realize accurate control of the entire cleaning process. This not only improves the controllability and repeatability of the cleaning process, ensures the consistency of the cleaning effect each time, but also helps to improve the stability of the CMP process and the stability of the product quality, and reduces wafer processing defects and process fluctuations caused by human operation errors or unstable cleaning processes.

[0107] As shown in Figure 7 , the fluid channel 43 is configured as branch channel one 436 and branch channel two 437. The branch channel one 436 communicates with the first nozzle 411 and the second nozzle 412. The branch channel two 437 communicates with the fourth nozzle 414. As shown in Figure 8 , the branch channel one 436 is provided with a reserved hole 441, which is plugged with a plug. When the reserved hole 441 needs to be used, the plug in the reserved hole 441 can be removed (after the reserved hole 441 is used, a nozzle or other pipeline can be installed, etc.), which improves the adaptability of the branch channel one 436. The operator can choose whether to remove the plug according to the actual cleaning needs. As shown in Figure 8 , the branch channel one 436 is also provided with a mounting hole 440 for mounting the regulating valve 438. As shown in Figure 9 , the branch channel two 437 is also provided with a mounting hole 440 for mounting the regulating valve 438. As shown in Figure 10 , the regulating valve 438 is provided with a through opening. When the regulating valve 438 is rotated to the position as shown in Figure 10 , the regulating valve 438 is opened, and the through opening allows the fluid to pass through the branch channel one 436. When the regulating valve 438 is rotated to the position as shown in Figure 11In the indicated position, regulating valve 438 is closed, and the through opening does not allow fluid to pass through branch passage 436. For example... Figure 12 As shown, a limiting surface 439 is provided on the main body surface. Correspondingly, a mating clamp is provided on the outer surface of the regulating valve 438, which can lock into the corresponding limiting surface 439 after the regulating valve 438 is rotated, realizing a limiting function and preventing inaccurate positioning when rotating the regulating valve 438, thus preventing the desired on or off state from being not achieved. Similarly, branch channel two 437 is provided with the same structure as branch channel one 436. By controlling the opening and closing degree of the regulating valve 438, the nozzles located on branch channel one 436 or branch channel two 437 can be specifically adjusted to whether the nozzles spray cleaning fluid and the flow rate of the sprayed cleaning fluid. At the same time, when the regulating valve 438 is in the closed state, the corresponding nozzles can be replaced or maintained.

[0108] According to another embodiment of the present invention, a cleaning method for a CMP polishing chamber is also provided, using the cleaning apparatus described above. See also Figure 13 The cleaning method includes the following steps:

[0109] S1: Nozzle 41 ejects fluid to clean the surface 3 of the polishing unit.

[0110] Optionally, in step S1, nozzle 41 first sprays out a gas-liquid mixture, then sprays out a liquid, and finally sprays out a gas.

[0111] In this embodiment, the specific order in which the fluid is ejected from the nozzle 41 is first the gas-liquid mixture, then the liquid, and finally the gas. This specific order is carefully determined based on the characteristics of contaminants on the surface of the CMP chamber and to reduce cleaning fluid consumption while improving the cleaning effect.

[0112] In the initial stage, the gas-liquid mixture utilizes the impact and agitation of the gas, along with the dissolving and penetrating capabilities of the liquid, to preliminarily decompose and peel off various surface contaminants, creating favorable conditions for subsequent cleaning steps. After the gas-liquid mixture has acted, although some contaminants have been removed, some fine particles, impurities dissolved in the liquid, and residual stains from air bubbles may still remain. At this point, the sprayed liquid, with its large flow rate and good fluidity, thoroughly washes away these residual contaminants, ensuring a higher level of surface cleanliness. Finally, the sprayed gas quickly blows off surface droplets, preventing water stains from forming. This sequential setup creates a logically rigorous and interconnected system for the cleaning process. It not only comprehensively and efficiently cleans various contaminants commonly found on CMP chamber surfaces, significantly improving cleanliness, but also reduces the consumption of cleaning fluid (the gas can be sourced from within polishing chamber 1, forming a circulation loop without increasing gas production costs), lowering costs and reducing wastewater generation.

[0113] Optionally, in step S1, the time for the nozzle 41 to spray the gas-liquid mixture is greater than the time for the nozzle 41 to spray the liquid; the time for the nozzle 41 to spray the gas-liquid mixture is greater than the time for the nozzle 41 to spray the gas.

[0114] In this embodiment, the spraying time of different fluids is controlled so that the cleaning time of the gas-liquid mixture is relatively long, which is an optimized design considering the unique role and importance of the gas-liquid mixture in the entire cleaning process. The gas-liquid mixture has an irreplaceable advantage in treating the complex dirt structure on the surface of the CMP chamber, which can simultaneously exert the physical impact of the gas and the chemical dissolution of the liquid. For some stubborn dirt layers, such as long-term accumulated polishing liquid residues and dirt formed by chemical reaction with the surface, a longer time is needed for their complete decomposition and removal. For example, for some hard dirt shells formed by the reaction of metal ions on the surface of the polishing pad, the gas-liquid mixture may need to act continuously to effectively break and dissolve them. The cleaning time of the liquid and the gas is relatively short because after the gas-liquid mixture completes the main decontamination work, the liquid mainly performs the final rinsing to ensure that there are no residual dirt particles, dissolved impurities, or bubble stains, and the time required is relatively short. The drying effect of the gas is even faster, and the liquid droplets on the surface can be removed quickly. Such time control can not only ensure the thoroughness of the cleaning effect, but also improve the cleaning efficiency and reduce the entire cleaning cycle, thereby improving the utilization rate of the CMP equipment and increasing the processing yield of the wafer, while ensuring product quality and improving production efficiency.

[0115] Optionally, in step S1, the volume ratio of the gas to the liquid in the gas-liquid mixture sprayed by the nozzle 41 is less than one-third.

[0116] In this embodiment, in the gas-liquid mixture, the liquid component plays a core role in dissolving and flushing dirt. The contaminants on the surface of the CMP chamber are mostly solid particles, residual chemicals, and dirt mixtures formed by their combination, which need the dissolving ability and strong flushing force of the liquid to be effectively removed from the surface. If the gas proportion is too high, the gas-liquid mixture will become too "thin", and the dissolving and flushing effect of the liquid will be greatly reduced, which cannot effectively carry away the contaminants from the surface. Controlling the volume ratio of the gas to the liquid to be less than one-third can ensure that the liquid dominates in the mixture, so that it has strong dissolving and flushing ability to deal with a large amount of solid particles, residual chemicals, and other contaminants that may exist on the surface of the CMP chamber, ensuring that the gas-liquid mixture can effectively remove and carry away the contaminants from the surface, thereby improving the cleaning effect and cleaning quality.

[0117] Optionally, in step S1, during the process of the nozzle 41 spraying the gas-liquid mixture, the volume ratio of the gas to the liquid gradually decreases.

[0118] In this embodiment, the volume ratio of gas to liquid in the gas-liquid mixture gradually decreases during the spraying process. This dynamic ratio change is designed to better adapt to the changing conditions during the cleaning process, where the dirt gradually decreases and the surface gradually cleans. In the early stage of cleaning, the surface dirt is more serious and complex in structure, and the relatively high gas ratio can play a strong role in disturbance and impact. For example, a higher proportion of gas can cause the gas-liquid mixture to produce a more intense "explosion" effect when it contacts the surface, rapidly loosening and breaking up large areas of dirt layer, creating good conditions for liquid penetration and dissolution. As the cleaning progresses, the dirt is gradually removed and the cleanliness of the surface gradually improves, at which time more liquid is needed for fine scrubbing and dissolving of residual small dirt particles. Gradually reducing the gas ratio and increasing the liquid ratio can gradually change the cleaning ability of the mixture to dissolution and fine scrubbing. For example, in the later stage of cleaning, when most of the dirt has been removed, leaving only some small particles and slight chemical residues, a higher proportion of liquid can more accurately dissolve and scrub these residues to ensure that the surface reaches an extremely high level of cleanliness. This dynamic ratio control can further optimize the cleaning effect, improve the thoroughness and uniformity of cleaning, and make the cleaning process more intelligent and fine, meeting the strict requirements of the CMP process for chamber surface cleanliness and providing ideal surface conditions for high-quality wafer polishing.

[0119] The cleaning method further includes the following steps:

[0120] S2: Transport the wafer to the wafer loading cup 21 in the polishing chamber 1;

[0121] S3: The polishing head 22 picks up the wafer and moves it to the polishing pad to perform chemical mechanical polishing. During the process of the polishing head 22 picking up the wafer and moving it to the polishing pad and / or during the chemical mechanical polishing of the wafer, the wafer loading cup cleaning nozzle sprays fluid to clean the surface of the wafer loading cup 21;

[0122] S4: The wafer loading cup cleaning nozzle stops cleaning the wafer loading cup 21, the chemical mechanical polishing of the wafer is completed, the polishing head 22 carries the wafer to the wafer loading cup 21, and at the same time, the polishing head cleaning nozzle sprays fluid to clean the surface of the polishing head 22;

[0123] S5: Transport the wafer out of the polishing chamber 1, and the polishing head cleaning nozzle sprays fluid to clean the surface of the polishing head 22;

[0124] S6: Repeat S2-S5.

[0125] In this embodiment, the cleaning method is coordinated with the wafer transfer, polishing and other steps in the CMP process to achieve seamless connection between cleaning and CMP process, and a highly efficient, stable and highly automated wafer processing system is constructed.

[0126] In S2, the wafer is placed on the wafer loading cup 21 to establish an accurate starting point for subsequent operations.

[0127] In S3, the wafer loading cup cleaning nozzle cleans the surface of the loading cup 21 while the polishing head 22 picks up and moves the wafer to the polishing pad and / or performs the chemical mechanical polishing process. This operation can timely remove the tiny particles, residual polishing liquid or environmental impurities that may be contaminated from the wafer on the wafer loading cup 21, prevent them from contaminating new wafers in subsequent cycles, and maintain the overall cleanliness of the polishing chamber, reduce wafer surface defects caused by contamination, and improve the yield and quality stability of wafer processing.

[0128] In S4, after the polishing is completed, the polishing head 22 carries the wafer back to the wafer loading cup 21 while the polishing head cleaning nozzle cleans the surface of the polishing head 22. At this time, the surface of the polishing head 22 is covered with residual substances generated during the polishing process, such as polishing liquid, wafer grinding dust and chemical reaction products. Timely cleaning can prevent these residues from solidifying on the surface of the polishing head, reduce the difficulty of subsequent cleaning, maintain the good working condition of the polishing head, and thus ensure the uniformity and accuracy of the pressure applied to the wafer during the next polishing operation, and stabilize the polishing effect of the wafer.

[0129] In S5, after the wafer is transferred out of the polishing chamber 1, the surface of the polishing head 22 is cleaned again, which can have more time to completely remove the previous residual dirt, further ensuring the reliability and stability of the performance of the polishing head 22. This helps to prolong the service life of the polishing head 22, reduce wear and corrosion caused by pollution, and at the same time provides consistent polishing conditions for the processing of the next batch of wafers, avoids process fluctuations caused by different levels of pollution of the polishing head 22, and ensures the consistency and repeatability of the quality of different batches of wafer products.

[0130] The S2-S5 is repeatedly constructed to build an efficient and stable CMP process cycle. This timely cleaning takes advantage of the short time and low firmness of the polishing liquid and other stains on the surface of the wafer loading cup 21 or the surface of the polishing head 22 to achieve good cleaning effect with lower cleaning fluid consumption, and can effectively reduce the damage caused by strong cleaning to the wafer loading cup 21 and the polishing head 22.

[0131] Optionally, in step S4, the polishing head cleaning nozzle sprays fluid to briefly clean the surface of the polishing head 22, and the cleaning time is 2s.

[0132] In this embodiment, after the polishing of the wafer is completed, the polishing head 22 carrying the wafer is moved to the wafer loading cup 21. In this process, the polishing head cleaning nozzle sprays fluid to briefly clean the surface of the polishing head 22, and the cleaning time is 2s. After the polishing is completed, the surface of the polishing head 22 is most likely to have a large amount of residues attached, including polishing liquid, material particles abraded from the surface of the wafer during polishing, and products generated by possible chemical reactions. If these residues are not treated in time, they will gradually dry and solidify on the surface of the polishing head, increasing the difficulty of subsequent cleaning, and even possibly causing permanent damage to the surface of the polishing head, affecting the service life and performance of the polishing head. While the wafer is being placed back into the wafer loading cup, this 2s of brief cleaning is performed, which, although short in time, can quickly remove a portion of the contaminants that have just formed and have not yet completely solidified, creating very favorable conditions for subsequent more thorough and more comprehensive cleaning of the polishing head after the wafer is transferred out of the polishing chamber. This helps to maintain the initial clean state of the polishing head 22 after each use, thereby ensuring that the pressure applied by the polishing head 22 to the wafer can be accurately controlled when the wafer is picked up for polishing next time, so that the pressure is uniformly distributed on the surface of the wafer, thereby stabilizing the polishing quality of the wafer and reducing problems such as unevenness of the wafer surface, local overpolishing or underpolishing of the wafer surface caused by contamination of the surface of the polishing head 22.

[0133] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and not to limit the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present application, and all should be covered in the scope of the claims of the present application.

Claims

1. A cleaning apparatus for a CMP polishing chamber, the polishing chamber having a polishing unit housed therein, the polishing unit comprising a wafer loading cup and a polishing head; characterized by, The cleaning device comprises: a plurality of nozzles arranged in the polishing chamber, wherein the nozzles comprise wafer boat cleaning nozzles and polishing head cleaning nozzles, and the nozzles are used to spray fluid to clean the wafer boat and the polishing head respectively, and the fluid sprayed by the nozzles is liquid and / or gas and / or gas-liquid mixture; a plurality of bodies arranged in the polishing chamber, wherein the bodies are arranged around the polishing head; the polishing head has an upper surface and a side surface; the polishing head cleaning nozzles comprise first nozzles and second nozzles, and the first nozzles and the second nozzles are arranged on one side of the polishing head, wherein the first nozzles are used to clean the upper surface, and the second nozzles are used to clean the side surface; when the polishing head is cleaned, the following steps are performed: A1: the polishing head cleaning nozzles on the plurality of bodies around the polishing head are opened simultaneously to clean the polishing head; A2: the polishing head cleaning nozzles on the plurality of bodies are opened in sequence along the circumference of the polishing head to clean the polishing head until all the polishing head cleaning nozzles on the plurality of bodies are opened; A3: the polishing head cleaning nozzle on one of the bodies is opened to clean the polishing head, the polishing head cleaning nozzle is closed after cleaning for a time a, the polishing head cleaning nozzle on another body adjacent to the body in the rotation direction of the polishing head or in the opposite direction is opened to clean the polishing head, the polishing head cleaning nozzle is closed after cleaning for a time b, and the above steps are repeated in sequence and cyclically; any sequence combination of A1, A2 and A3; if the rotation speed of the polishing head is constant, a = b; if the rotation speed of the polishing head increases, a < b; and if the rotation speed of the polishing head decreases, a > b.

2. The cleaning apparatus for a CMP polishing chamber of claim 1, wherein, the first nozzles are used to spray fan-shaped fluid; and the second nozzles are used to spray cone-shaped fluid.

3. The cleaning apparatus for a CMP polishing chamber of claim 1, wherein, the wafer boat cleaning nozzles comprise fourth nozzles, and the fourth nozzles are arranged on one side of the wafer boat, wherein the fourth nozzles are used to clean the upper surface of the wafer boat.

4. The cleaning apparatus for a CMP polishing chamber of claim 1, wherein, the nozzles are used to spray gas-liquid mixture, liquid and gas in sequence.

5. The cleaning apparatus for a CMP polishing chamber of claim 4, wherein, the ratio of gas to liquid in the gas-liquid mixture sprayed by the nozzles is adjustable.

6. The cleaning apparatus for a CMP polishing chamber of claim 1, wherein, the bodies have fluid channels, the fluid channels have fluid outlets and fluid inlets, the nozzles are arranged on the bodies, and the inlets of the nozzles are in communication with the fluid outlets.

7. The cleaning apparatus for a CMP polishing chamber of claim 6, wherein, the fluid inlets comprise liquid inlets and gas inlets, the liquid inlets are used to communicate with a liquid source, the gas inlets are used to communicate with a gas source, and flow valves are arranged between the liquid inlets and the liquid source and between the gas inlets and the gas source.

8. A cleaning method for a CMP polishing chamber using the cleaning apparatus of any one of claims 1-7, characterized in that, the cleaning method comprises the following steps: S1: controlling the nozzles to spray fluid to clean the surface of the polishing unit; S2: transporting a wafer to a wafer boat in the polishing chamber; S3: picking up the wafer by the polishing head and moving the wafer to a polishing pad to perform chemical mechanical polishing, wherein the wafer boat cleaning nozzles spray fluid to clean the surface of the wafer boat during the process of picking up the wafer by the polishing head and moving the wafer to the polishing pad and / or during the process of performing chemical mechanical polishing on the wafer; S4: stopping the wafer boat cleaning nozzles from cleaning the wafer boat, ending the chemical mechanical polishing of the wafer, moving the polishing head carrying the wafer to the wafer boat, and spraying fluid by the polishing head cleaning nozzles to clean the surface of the polishing head while the polishing head carrying the wafer is moving to the wafer boat. S5: the wafer is transported out of the polishing chamber, and the polishing head cleaning nozzles spray fluid to clean the surface of the polishing head; S6: repeating S2-S5.

9. The cleaning method for a CMP polishing chamber of claim 8, wherein, The nozzles first spray a gas-liquid mixture, then spray liquid, and finally spray gas.

10. The cleaning method for a CMP polishing chamber of claim 8, wherein, In step A3, the polishing head cleaning nozzles on the plurality of bodies are opened in sequence to clean the same area of the polishing head while the polishing head is rotating.

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