Wafer cleaning device and method thereof

Abstract

The present invention discloses a wafer cleaning device and method thereof, wherein the device comprises a computer; a liquid storage tank; a micro pump; a high-voltage electrostatic generator; an ammeter; a camera; a nozzle; an electrode ring; an insulating voltage-stabilizing component; a fixed stand base; a light source; a clean buckle; a swing component; a universal support plate; a waste liquid tank; a bracket; and a clean chamber. The wafer cleaning method and device proposed in the present invention cleans the wafer surface by electrostatic spraying, and monitors and regulates the electrostatic micro-spray cleaning situation in real time. The structure is simple, the cost is low, the wafer cleaning efficiency and yield are higher than those of the traditional wafer cleaning method, the wafer cleaning efficiency and cleaning quality are improved, the cleaning process cost is reduced, the cleaning process safety is improved, and a new approach is provided for IC manufacturing process.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductor manufacturing, and in particular relates to a wafer cleaning device and a method thereof. Background Art

[0002] The chip industry belongs to the high-tech field in social development and national economy, and plays an important role in the country's economic development. As the predecessor of chips, wafers are the basic raw materials for making silicon semiconductor circuits. They occupy an important position in the high-end manufacturing industry, and their quality significantly affects the quality of semiconductor integrated circuits. The original material of the wafer is silicon. After dissolving the crystalline silicon and adding the seed crystal, it is stretched into a single crystal silicon rod. After slicing, grinding, chamfering, polishing and other steps, the silicon crystal rod forms a silicon wafer, that is, a wafer. During the processing, the wafer inevitably comes into contact with various organic matter, particles and metals, resulting in the generation of pollutants on the surface. At present, physical, chemical or mechanical cleaning methods are usually used to desorb the pollutants adsorbed on the surface of the wafer, thereby cleaning the wafer surface. With the rapid development of integrated circuit process technology and the continuous reduction of critical dimensions, the quality of wafer cleaning in the integrated circuit manufacturing process has become a key factor affecting the performance, reliability and stability of advanced electronic devices.

[0003] Wet cleaning is a more commonly used wafer cleaning method, which uses chemical solvents and deionized water to oxidize, etch and dissolve pollutants, organic matter and metal ions on the surface of the wafer, thereby cleaning the wafer surface. The specific steps are to first rinse off larger residues with a detergent, then use a large amount of deionized water to remove the detergent, and finally dry the wafer surface. However, the wet cleaning method has many problems during the cleaning process, such as difficulty in removing fine residues, strong impact will cause defects on the wafer surface and uneven cleaning range. Therefore, there is an urgent need for a new type of efficient and controllable wafer cleaning method to meet the needs of integrated circuit manufacturing processes. Summary of the invention

[0004] In response to the above technical problems, one of the purposes of one embodiment of the present invention is to provide a wafer cleaning device, which charges the cleaning liquid to generate charged droplets from the electrostatic microspray. The charged droplets can use electrostatic force to effectively adsorb smaller-sized contamination particles adhered to the wafer surface that are difficult to handle with traditional cleaning methods, thereby further improving the cleanliness of the wafer surface.

[0005] One of the purposes of one embodiment of the present invention is to form micro-scale droplets of cleaning liquid through electrostatic micro-spraying, which greatly reduces the droplet particle size and avoids the impact damage of large-sized droplets on the wafer surface, which is beneficial to protecting the wafer surface and improving the wafer cleaning quality.

[0006] One of the purposes of one embodiment of the present invention is to utilize an electric field to generate electrostatic micro-spray to form a large number of small droplets of the cleaning liquid, thereby increasing the number of cleaning liquid droplets on the wafer surface with the same amount of cleaning liquid, avoiding waste of cleaning liquid, improving the efficiency of cleaning liquid use, and being able to significantly reduce the amount of cleaning liquid used, thereby saving wafer cleaning costs.

[0007] One of the purposes of one embodiment of the present invention is to use electrostatic micro-spraying to form a cleaning spray with a larger spray cone angle, which can increase the cleaning coverage of the droplet group on the wafer surface, further improving the wafer cleaning efficiency and the efficiency of cleaning liquid use.

[0008] One of the purposes of one embodiment of the present invention is to use electrostatic micro-spraying to form a spray droplet group with a relatively uniform particle size distribution, thereby improving the uniformity of cleaning the wafer surface with the cleaning liquid.

[0009] One of the purposes of one embodiment of the present invention is to use a camera in combination with a background light source to achieve real-time monitoring of the spraying of the cleaning liquid. The quality of the electrostatic spray is dynamically displayed by a computer, which facilitates timely adjustment of the cleaning parameters of the electrostatic spray system.

[0010] One of the purposes of one embodiment of the present invention is to utilize a high-voltage electrostatic generator and a pump to realize the regulation of the spray effect of the cleaning liquid. By adjusting the voltage and flow parameters of the electrostatic spray system, the best wafer cleaning effect can be achieved, which is beneficial to improving the wafer cleaning efficiency and quality.

[0011] One of the purposes of one embodiment of the present invention is to utilize a rotatable component to change the tilt angle of the wafer during the cleaning process, so as to remove residual cleaning liquid on the surface of the wafer and simultaneously clean the front and back sides of the wafer, thereby further improving the wafer cleaning efficiency.

[0012] One of the purposes of one embodiment of the present invention is to dynamically monitor the current of the electrostatic spray system through an ammeter, which helps to control the electrostatic spray parameters and improve the safety of wafer cleaning.

[0013] One of the purposes of one embodiment of the present invention is to provide a cleaning method for a wafer cleaning device, in which a cleaning liquid is passed through a nozzle to generate an electrostatic spray with controllable charge, spray cone angle, droplet particle size, etc., so as to achieve the purpose of efficiently removing contaminants from the wafer surface. The device has a simple structure, low cost, and simple operation, and the wafer cleaning efficiency and yield are higher than those of traditional wafer cleaning methods.

[0014] One of the purposes of one embodiment of the present invention is to place wafer cleaning inside a cavity, thereby avoiding contamination of the wafer surface by the external environment, which is beneficial to improving the wafer cleaning quality.

[0015] Note that the description of these objectives does not prevent the existence of other objectives. One embodiment of the present invention does not need to achieve all of the above objectives. Objectives other than the above objectives can be extracted from the description of the specification, drawings, and claims.

[0016] The technical solution of the present invention is: a wafer cleaning device, comprising a liquid storage tank, a pump, a high-voltage electrostatic generator, a nozzle, an electrode ring, an insulating voltage-stabilizing component, a stand base, a bracket and a cavity;

[0017] The brackets are installed on both sides of the upper part of the cavity;

[0018] The two ends of the insulating voltage stabilizing component are respectively connected to the bracket, the liquid inlet of the pump is connected to the liquid storage tank, the liquid outlet is connected to the insulating voltage stabilizing component, the insulating voltage stabilizing component is connected to the liquid inlet of the nozzle, and the nozzle is connected to the high-voltage electrostatic generator;

[0019] The electrode ring is arranged below the liquid outlet of the nozzle;

[0020] The platform base includes a first fixed platform base and a second fixed platform base, the first fixed platform base and the second fixed platform base are arranged below the electrode ring, and the first fixed platform base and the second fixed platform base are used to place wafer workpieces to be cleaned.

[0021] The above scheme also includes a computer, a camera and a light source;

[0022] The computer is connected to the camera and the light source respectively. The camera and the light source are installed in the cavity, and the camera and the light source are located on both sides of the nozzle respectively.

[0023] Furthermore, a slide rail is provided on the bracket, and sliders connected to the slide rail are provided at both ends of the insulating voltage stabilizing component. The insulating voltage stabilizing component is connected to a first driving mechanism, and the first driving mechanism is connected to a computer. The first driving mechanism is used to drive the insulating voltage stabilizing component to move along the bracket.

[0024] The above scheme also includes a buckle, a universal support plate and a swing assembly;

[0025] The universal support plate is located between the first fixed platform base and the second fixed platform base;

[0026] The first fixed platform base and the second fixed platform base are respectively provided with buckles, one end of the buckle is used to fix the wafer, and the other end is connected to the second driving mechanism, and the second driving mechanism is used to drive the buckle to drive the wafer to swing back and forth along its axis.

[0027] The above scheme also includes an ammeter, which is connected to the nozzle and the computer respectively.

[0028] The above scheme also includes a waste liquid pool; the waste liquid pool is located at the bottom of the cavity.

[0029] A cleaning method for a wafer cleaning device comprises the following steps:

[0030] The wafer to be cleaned is placed in the chamber and mounted on the stage base and the universal support plate by snap fasteners;

[0031] The cleaning liquid is stored in a liquid storage tank, and after the pump is started, the cleaning liquid is transported into the nozzle through an insulated pipe;

[0032] Start the high-voltage electrostatic generator, connect the nozzle to the high-voltage electrostatic generator and become charged. When the cleaning liquid passes through the nozzle pipe, it will be contact charged. When the cleaning liquid flows out from the nozzle outlet, an electrostatic micro-spray will be formed between the nozzle and the electrode ring to clean the wafer.

[0033] The above scheme also includes the following steps:

[0034] Start the swing assembly to allow the wafer to swing back and forth on the universal support plate and the stage base to change the tilt angle of the wafer.

[0035] The above scheme also includes the following steps:

[0036] During the wafer cleaning process, the camera, light source, and computer are turned on synchronously to dynamically monitor the cleaning status of the electrostatic spray and wafer;

[0037] The ammeter is started to monitor the current generated by the nozzle in real time.

[0038] The above scheme also includes the following steps:

[0039] According to the cleaning state, the first driving mechanism is controlled by a computer to drive the insulating voltage stabilizing component to move along the bracket to adjust the cleaning position;

[0040] According to the cleaning status, the high voltage electrostatic generator and pump are dynamically adjusted by the computer to change the charging voltage and spray flow rate.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] According to one embodiment of the present invention, the cleaning liquid is charged to generate charged droplets from the electrostatic microspray. The charged droplets can utilize electrostatic force to effectively adsorb smaller contamination particles adhering to the wafer surface that are difficult to handle with traditional cleaning methods, thereby further improving the cleanliness of the wafer surface.

[0043] According to one embodiment of the present invention, the cleaning liquid is formed into micro-scale droplets by electrostatic micro-spraying, which greatly reduces the droplet particle size and avoids the impact damage of large-sized droplets on the wafer surface, which is beneficial to protecting the wafer surface and improving the wafer cleaning quality.

[0044] According to one embodiment of the present invention, an electric field is used to generate electrostatic micro-spray to form a large number of small droplets of the cleaning liquid. This increases the number of cleaning liquid droplets on the wafer surface with the same amount of cleaning liquid, avoids waste of cleaning liquid, improves the efficiency of cleaning liquid use, can significantly reduce the amount of cleaning liquid used, and saves wafer cleaning costs.

[0045] According to one embodiment of the present invention, electrostatic micro-spraying is used to form a cleaning spray with a larger spray cone angle, which can increase the cleaning coverage of the wafer surface by the droplet group, further improving the wafer cleaning efficiency and the efficiency of cleaning liquid use.

[0046] According to one embodiment of the present invention, electrostatic micro-spraying is used to form a spray droplet group with a relatively uniform particle size distribution, thereby improving the uniformity of cleaning the wafer surface with the cleaning liquid.

[0047] According to one embodiment of the present invention, a camera combined with a background light source can be used to monitor the spraying of the cleaning liquid in real time, and the quality of the electrostatic spray can be dynamically displayed by a computer, so as to facilitate timely adjustment of the cleaning parameters of the electrostatic spray system.

[0048] According to one embodiment of the present invention, a high-voltage electrostatic generator and a pump are used to control the spray effect of the cleaning liquid. By adjusting the voltage and flow parameters of the electrostatic spray system, the best wafer cleaning effect can be achieved, which is beneficial to improving the wafer cleaning efficiency and quality.

[0049] According to one embodiment of the present invention, a rotatable component is used to change the tilt angle of the wafer during the cleaning process, which can not only remove residual cleaning liquid on the surface of the wafer but also clean the front and back sides of the wafer, further improving the wafer cleaning efficiency.

[0050] According to one embodiment of the present invention, the current of the electrostatic spray system is dynamically monitored by an ammeter, which helps to control the electrostatic spray parameters and improve the safety of wafer cleaning.

[0051] According to one embodiment of the present invention, wafer cleaning is placed inside the cavity, thereby avoiding contamination of the wafer surface by the external environment, which is beneficial to improving the wafer cleaning quality.

[0052] According to one embodiment of the present invention, through the cleaning method of the wafer cleaning device, the cleaning liquid is passed through the nozzle to generate an electrostatic spray with controllable charge, spray cone angle, droplet particle size, etc., so as to achieve the purpose of efficiently removing pollutants from the wafer surface. The device has a simple structure, low cost, simple method operation, and higher wafer cleaning efficiency and yield than traditional wafer cleaning methods.

[0053] Note that the description of these effects does not prevent the existence of other effects. One embodiment of the present invention does not necessarily have all of the above effects. Effects other than the above can be clearly seen and extracted from the description of the specification, drawings, claims, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 It is a schematic diagram of a front view of the structure of a wafer cleaning device according to one embodiment of the present invention.

[0055] Figure 2 It is a schematic diagram of a side view of the structure of a wafer cleaning device according to one embodiment of the present invention.

[0056] Figure 3 Schematic diagram of a droplet in an uncharged state.

[0057] Figure 4 It is a schematic diagram of charged droplets adsorbing small-sized particles according to one embodiment of the present invention.

[0058] Figure 5 It is a schematic diagram of charged spray cleaning according to one embodiment of the present invention.

[0059] Figure 6 This is a diagram of a charged spray at a nozzle outlet according to one embodiment of the present invention.

[0060] Figure 7 Schematic diagram comparing charged spray and conventional mechanical spray according to one embodiment of the present invention, wherein Figure 7 (a) is charged spray, Figure 7 (b) is conventional mechanical spray.

[0061] In the figure: 1. Computer; 2. Liquid storage tank; 3. Pump; 4. High-voltage electrostatic generator; 5. Ammeter; 6. Camera; 7. Nozzle; 8. Electrode ring; 9. Insulation voltage stabilizing component; 10. Wafer; 111. First fixed stand base; 112. Second fixed stand base; 12. Light source; 13. Buckle; 14. Swing assembly; 15. Universal support plate; 16. Waste liquid tank; 17. Bracket; 18. Cavity. DETAILED DESCRIPTION

[0062] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0063] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "front", "back", "left", "right", "up", "down", "axial", "radial", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are 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 limiting the present invention. In addition, 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. Therefore, 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 "multiple" is two or more, unless otherwise clearly and specifically defined.

[0064] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0065] Figure 1 The figure shows a preferred embodiment of the wafer cleaning device, which includes a liquid storage tank 2, a pump 3, a high-voltage electrostatic generator 4, a nozzle 7, an electrode ring 8, an insulating voltage stabilizing component 9, a stand base, a bracket 17 and a chamber 18;

[0066] The bracket 17 is installed on both sides of the upper part of the cavity 18;

[0067] The two ends of the insulating voltage stabilizing component 9 are respectively connected to the bracket 17, the liquid inlet of the pump 3 is connected to the liquid storage tank 2, the liquid outlet is connected to the insulating voltage stabilizing component 9, the insulating voltage stabilizing component 9 is connected to the liquid inlet of the nozzle 7, and the nozzle 7 is connected to the high-voltage electrostatic generator 4;

[0068] The electrode ring 8 is arranged below the liquid outlet of the nozzle 7. Preferably, the diameter of the electrode ring 8 is larger than the outer diameter of the nozzle 7.

[0069] The gantry base includes a first fixed gantry base 111 and a second fixed gantry base 112. The first fixed gantry base 111 and the second fixed gantry base 112 are arranged below the electrode ring 8. The first fixed gantry base 111 and the second fixed gantry base 112 are used to place wafer workpieces to be cleaned. A schematic diagram of the installation of a wafer 10 is given in the figure, and the wafer 10 can be installed in an array.

[0070] When the wafer cleaning device is cleaning the wafer 10, the cleaning agent in the liquid storage tank 2 is extracted by the pump 3, and then enters the voltage stabilizing component 9 through the pipeline to provide the cleaning agent with a certain pressure to the nozzle 7. The cleaning agent is charged by the high-voltage electrostatic generator 4 in the nozzle 7, and forms a liquid after passing through the nozzle 7 and the annular electrode 8. Figure 6 The electrostatic microspray shown in the figure produces Figure 4 The micro-scale charged droplets shown in FIG. 1 impact the surface of the wafer 10 to clean the wafer 10. The charged spray cleaning process is as follows: Figure 5 As shown in Figure 1, the charged droplets can absorb extremely small particles through electrostatic force, effectively improving the cleaning quality of the wafer surface. Figure 4 As shown, the uncharged droplet is Figure 3 As shown, extremely small particles cannot be adsorbed.

[0071] Preferably, it also includes a computer 1, a camera 6 and a light source 12; the computer 1 is connected to the camera 6 and the light source 12 respectively, the camera 6 and the light source 12 are installed in the cavity 18, and the camera 6 and the light source 12 are respectively located on both sides of the nozzle 7, and the light source 12 is installed opposite the camera 6 to illuminate the entire spray cleaning process, and the electrostatic atomization cleaning process photographed by the camera 6 is dynamically displayed on the computer 1 through the transmission line, so as to achieve the real-time monitoring effect of the electrostatic spray cleaning process;

[0072] like Figure 2 As shown, the bracket 17 is provided with a slide rail, and both ends of the insulating voltage stabilizing component 9 are provided with sliders connected to the slide rail. The insulating voltage stabilizing component 9 is connected to a first driving mechanism, and the first driving mechanism is connected to the computer 1. The first driving mechanism is used to drive the insulating voltage stabilizing component 9 to move along the bracket 17.

[0073] Preferably, it also includes a buckle 13, a universal support plate 15 and a swing assembly 14;

[0074] The universal support plate 15 is located between the first fixed platform base 111 and the second fixed platform base 112. The universal support plate 15 is in contact with the wafer 10 and is grounded to maintain the electrical neutrality of the wafer to avoid the influence of electrostatic adhesion. The center of the wafer 10 is supported by the universal support plate 15 to maintain uniform force and a flat surface of the wafer 10 during the swinging process.

[0075] The first fixed platform base 111 and the second fixed platform base 112 are respectively provided with a buckle 13; one end of the buckle 13 is used to fix the wafer 10, and the other end is connected to the second driving mechanism, and the second driving mechanism is used to drive the buckle 13 to drive the wafer 10 to swing back and forth along its axis.

[0076] Preferably, a waste liquid pool 16 is further included; the waste liquid pool 16 is located at the bottom of the cavity 18 .

[0077] During the front cleaning process of the wafer 10, the wafer 10 is first slowly rotated, swung and tilted clockwise by the rotating component 14 to clean the back side of the wafer 10, and the cleaning waste liquid can also be discharged into the waste liquid pool 16. After the wafer 10 is rotated, swung and tilted clockwise to a certain angle, the wafer 10 is slowly rotated counterclockwise and tilted to a certain angle by the rotating component 14 to clean the front side of the wafer 10, and the cleaning waste liquid is also discharged into the waste liquid pool 16 simultaneously. The front and back sides of the wafer 10 are cleaned. Preferably, an ammeter 5 is also included, and the ammeter 5 is respectively connected to the nozzle 7 and the computer 1 to obtain the current generated during the electrostatic spray cleaning process in real time to maintain the stable operation of the entire electrostatic spray cleaning system;

[0078] According to the real-time situation of electrostatic spraying, the high-voltage electrostatic generator 4 and the micropump 3 are used to adjust the charging voltage and the spray pressure, and the atomization cone angle of the electrostatic spray is controlled. The size of the atomization cone angle affects the uniformity of wafer cleaning. The size of the spray droplets is adjusted to control the impact of the droplets on the wall of the wafer 10 to obtain the ideal electrostatic micro-spray quality.

[0079] Preferably, the pump 3 is a micro pump.

[0080] Preferably, the nozzle 7 and the electrode ring 8 are arranged vertically, and the distance between them is generally set between 0-60 mm. The wafer 10 is placed 30-200 mm below the electrode ring 8. Within this distance range, the cleaning spray cone angle, droplet particle size and charge can be adjusted to achieve the best cleaning effect.

[0081] The wafer 10 and the universal support plate 15 need to be grounded. The ammeter 5 is connected to the nozzle 7 and the ground electrode respectively. The electrode ring 8 is grounded through a wire, and the grounding ends of the high-voltage electrostatic generator 4 and the ammeter 5 are grounded through a wire.

[0082] A cleaning method according to the wafer cleaning device comprises the following steps:

[0083] The wafer 10 to be cleaned is placed in the cavity 18 and mounted on the stage base and the universal support plate 15 through the buckle 13;

[0084] The cleaning liquid is stored in the liquid storage tank 2, and after the pump 3 is started, the cleaning liquid is transported into the nozzle 7 through the insulating pipe;

[0085] The high-voltage electrostatic generator 4 is started, and the nozzle 7 is connected to the high-voltage electrostatic generator 4 and charged. When the cleaning liquid passes through the nozzle 7 pipeline, it will be contact charged. When the cleaning liquid flows out from the nozzle 7 outlet, an electrostatic micro-spray will be formed between the nozzle 7 and the electrode ring 8 to clean the wafer 10.

[0086] Preferably, the method further comprises the following steps:

[0087] The swing assembly 14 is started to allow the wafer 10 to swing back and forth on the universal support plate 15 and the stage base, thereby changing the tilt angle of the wafer 10 .

[0088] Preferably, the method further comprises the following steps:

[0089] During the cleaning process of the wafer 10, the camera 6, the light source 12, and the computer 1 are turned on synchronously, and the electrostatic micro-spray generated by the nozzle 7 is illuminated by the background light provided by the light source 12 and recorded by the camera 6, and displayed in real time on the computer 1, so as to dynamically monitor the cleaning status of the electrostatic spray and the wafer 10;

[0090] The ammeter 5 is started to monitor the current generated by the nozzle 7 in real time to prevent abnormal conditions such as breakdown or overload of the high-voltage electrostatic generator 4 and maintain safe and efficient operation of the entire electrostatic spray wafer cleaning system.

[0091] Preferably, the method further comprises the following steps:

[0092] According to the cleaning state, the computer 1 controls the first driving mechanism to drive the insulating voltage stabilizing component 9 to move along the bracket 17 to adjust the cleaning position;

[0093] According to the cleaning status, the high voltage electrostatic generator 4 and the pump 3 are dynamically adjusted by the computer 1 to change the charging voltage and the spray flow rate to achieve the ideal cleaning effect.

[0094] Specific working principle:

[0095] The wafer 10 to be cleaned is placed in the cavity 18 in advance and fixed on the fixed stand base and the universal support plate 15 through the buckle 13. The cleaning liquid is stored in the liquid storage tank 2. After the pump 3 is started, the cleaning liquid is transported into the nozzle 7 through the insulating pipe. An insulating voltage stabilizing component 9 is installed at the inlet section of the atomizing nozzle 7 to ensure that the nozzle 7 has a stable atomizing pressure, thereby ensuring that the atomized spray has a stable flow rate, such as Figure 6 After the high-voltage electrostatic generator 4 is started, the nozzle 7 is connected to the high-voltage electrostatic generator 4 and charged. When the cleaning liquid passes through the nozzle 7 pipe, it will be contact charged. When the cleaning liquid flows out from the nozzle 7 outlet, an electrostatic micro-spray will be formed between the nozzle 7 and the electrode ring 8. The electrostatic spray forms a conical spray droplet group and produces a large amount of Figure 4The micro-scale charged droplets shown can cover the entire surface of the wafer 10. After the charged droplets come into contact with the surface of the wafer 10, the wafer 10 is cleaned. Figure 5 As shown, the charged droplets can adsorb smaller pollutants through electrostatic forces, such as Figure 4 As shown, the cleaning effect of the wafer 10 is improved. The rotating assembly 14 is started so that the wafer 10 can swing back and forth along its horizontal axis on the universal support plate 15 and the stand base, and the front and back sides of the wafer 10 are cleaned, further improving the wafer cleaning efficiency. During the cleaning process of the wafer 10, the camera 6, the light source 12 and the ammeter 5 are turned on synchronously to dynamically monitor the high-voltage electrostatic generator and its cleaning state of the wafer 10 to achieve dynamic adjustment of the electrostatic spray cleaning process. The electrostatic spray cleaning process is transmitted to the computer 1 in real time through the camera 6 to obtain the electrostatic spray cleaning state, and according to the electrostatic spray cleaning situation, the high-voltage electrostatic generator 4 and the pump 3 are dynamically adjusted to change the charging voltage and the spray flow rate to achieve the ideal cleaning effect. At the same time, the microcurrent generated by the high-voltage electrostatic generator 4 is displayed in real time by the ammeter 5 to prevent abnormal conditions such as breakdown or overload when the high-voltage electrostatic generator 4 is adjusted, and to maintain the safe and efficient operation of the entire electrostatic spray wafer cleaning system.

[0096] According to the different cleaning states of the wafer 10, the nozzle 7 can use different types of nozzles or stainless steel pipes, and the delivery and supply method of the cleaning liquid is not limited to the pump 3, and other forms can also be adopted. However, no matter what kind of supply method of the cleaning liquid and the atomizing nozzle 7, the cleaning liquid will generate a group of charged droplets under the action of the electric field, and the charged micro-droplets will contact the wafer 10 to clean the wafer 10. During the cleaning process of the wafer 10, the electrostatic spray can not only clean the surface of the wafer 10 through the spray droplet group, but the additional electric field force / Coulomb force generated by the charged droplets and the external electric field can effectively adsorb the tiny-sized surface pollutants of the wafer 10, which is conducive to improving the cleaning ability of the wafer cleaning droplets on the wafer surface and improving its cleaning efficiency.

[0097] The device can clean the contaminants on the surface of the wafer 10, and can also use the same principle to perform electrostatic spray cleaning on other objects with high surface cleanliness requirements. Following the same steps, large particle contaminants and small-sized impurities on the surface can also be removed to achieve the purpose of cleaning the wall surface. Figure 7 As shown, according to Figure 7 (a) Figure 7 (b) By comparison, it can be seen that the charged spray has a wider range and better uniformity than conventional mechanical spray.

[0098] The efficient and safe wafer cleaning method and device proposed in the present invention adopt electrostatic spraying to clean the wafer surface, and monitor and regulate the electrostatic micro-spray cleaning situation in real time, thereby improving the wafer cleaning efficiency and cleaning quality, reducing the cleaning process cost, and improving the safety of the cleaning process, providing a new approach for IC cleaning technology.

[0099] It should be understood that although this specification is described according to various embodiments, not every embodiment contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0100] The series of detailed descriptions listed above are only specific descriptions of feasible embodiments of the present invention. They are not intended to limit the scope of protection of the present invention. All equivalent embodiments or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. A wafer cleaning device, characterized in that: It comprises a liquid storage tank (2), a pump (3), a high-voltage electrostatic generator (4), a nozzle (7), an electrode ring (8), an insulating voltage-stabilizing component (9), a bench base, a bracket (17) and a cavity (18); The bracket (17) is installed on both sides of the upper part of the cavity (18); The two ends of the insulating voltage-stabilizing component (9) are respectively connected to the bracket (17), the liquid inlet of the pump (3) is connected to the liquid storage tank (2), the liquid outlet is connected to the insulating voltage-stabilizing component (9), the insulating voltage-stabilizing component (9) is connected to the liquid inlet of the nozzle (7), and the nozzle (7) is connected to the high-voltage electrostatic generator (4); The electrode ring (8) is arranged below the liquid outlet of the nozzle (7); The platform base comprises a first fixed platform base (111) and a second fixed platform base (112), the first fixed platform base (111) and the second fixed platform base (112) being arranged below the electrode ring (8), and the first fixed platform base (111) and the second fixed platform base (112) being used to place wafers (10) to be cleaned; It also includes a universal support plate (15), the universal support plate (15) being located between the first fixed platform base (111) and the second fixed platform base (112); the universal support plate (15) is in contact with the wafer (10), and the wafer (10) and the universal support plate (15) are grounded; the electrode ring (8) is grounded via a wire; Also includes a computer (1), a camera (6) and a light source (12); The computer (1) is connected to a camera (6) and a light source (12) respectively; the camera (6) and the light source (12) are installed in a cavity (18); and the camera (6) and the light source (12) are located on both sides of the nozzle (7) respectively; The support (17) is provided with a slide rail, and both ends of the insulating voltage stabilizing component (9) are provided with sliders connected to the slide rail. The insulating voltage stabilizing component (9) is connected to a first driving mechanism, and the first driving mechanism is connected to a computer (1). The first driving mechanism is used to drive the insulating voltage stabilizing component (9) to move along the support (17); It also includes a buckle (13) and a swing assembly (14); A buckle (13) is respectively mounted on the first fixed platform base (111) and the second fixed platform base (112); one end of the buckle (13) is used to fix the wafer (10), and the other end is connected to a second driving mechanism; the second driving mechanism is used to drive the buckle (13) to drive the wafer (10) to swing back and forth along its axis; It also includes an ammeter (5), which is connected to the nozzle (7) and the computer (1) respectively.

2. The wafer cleaning device according to claim 1, characterized in that: It also includes a waste liquid pool (16); the waste liquid pool (16) is located at the bottom of the cavity (18).

3. A cleaning method for a wafer cleaning device according to claim 1 or 2, characterized in that: The steps include: Place the wafer (10) to be cleaned into the cavity (18) and mount it on the stage base and the universal support plate (15) through the buckle (13); The cleaning liquid is stored in a liquid storage tank (2), and after the pump (3) is started, the cleaning liquid is transported into the nozzle (7) through the insulating pipe; The high-voltage electrostatic generator (4) is started, and the nozzle (7) is connected to the high-voltage electrostatic generator (4) and charged. When the cleaning liquid passes through the nozzle (7) pipe, it will be contact charged. When the cleaning liquid flows out from the nozzle (7) outlet, an electrostatic micro-spray will be formed between the nozzle (7) and the electrode ring (8), thereby cleaning the wafer (10).

4. The cleaning method of the wafer cleaning device according to claim 3, characterized in that: The following steps are also included: The swing assembly (14) is started to enable the wafer to swing back and forth on the universal support plate (15) and the stage base, thereby changing the tilt angle of the wafer (10).

5. The cleaning method of the wafer cleaning device according to claim 3, characterized in that: The following steps are also included: During the cleaning process of the wafer (10), the camera (6), the light source (12), and the computer (1) are synchronously turned on to dynamically monitor the cleaning status of the electrostatic spray and the wafer (10); The ammeter (5) is started to monitor the current generated by the nozzle (7) in real time.

6. The cleaning method of the wafer cleaning device according to claim 3, characterized in that: The following steps are also included: According to the cleaning state, the computer (1) controls the first driving mechanism to drive the insulating voltage stabilizing component (9) to move along the bracket (17) to adjust the cleaning position; According to the cleaning state, the high voltage electrostatic generator (4) and the pump (3) are dynamically adjusted by the computer (1) to change the charging voltage and the spray flow rate.

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