Wafer cleaning device and cleaning method

Abstract

The embodiment of the invention provides a wafer cleaning device and method, a wafer is provided with a first surface and a second surface which are opposite to each other, and the first surface is a surface to be cleaned; the cleaning device comprises a detection unit which is used for detecting whether foreign matters exist on the first surface of the wafer or not and determining the position of the foreign matters on the wafer; the cleaning unit is used for cleaning the first surface of the wafer with foreign matters; and the control unit is used for controlling the cleaning unit to directionally remove the foreign matters according to the position. By adopting the wafer cleaning device provided by the embodiment of the invention, the production efficiency can be improved.

Description

Technical Field

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

[0002] At present, Metal Oxide Semiconductor (MOS) field effect transistors have been widely used in the semiconductor field, especially in smart cards, Radio Frequency Identification (RFID) devices, new mobile phones and other small, lightweight and powerful electronic devices, which has put forward higher requirements for the production of semiconductor devices.

[0003] However, in the actual process of manufacturing, there is a situation where the wafer is contaminated, resulting in a decrease in production efficiency. Therefore, how to provide a technical solution to clean the wafer to improve production efficiency has become a technical problem that technicians in this field need to solve urgently. Summary of the invention

[0004] The technical problem solved by the present invention is to clean the wafer by providing a wafer cleaning device and a wafer cleaning method to improve production efficiency.

[0005] In order to solve the above problems, an embodiment of the present invention provides a wafer cleaning device, wherein the wafer has a first surface and a second surface relative to each other, and the first surface is a surface to be cleaned; the cleaning device comprises: a detection unit, used to detect whether there is foreign matter on the first surface of the wafer, and determine the position of the foreign matter on the wafer; a cleaning unit, used to clean the first surface of the wafer where foreign matter exists; and a control unit, which controls the cleaning unit to remove the foreign matter in a directional manner according to the position.

[0006] Optionally, the cleaning unit comprises:

[0007] Rotatable shower nozzle for spraying cleaning fluid;

[0008] The control unit controls the shower nozzle to spray toward the foreign matter in a cleaning state;

[0009] A cleaning brush can be moved, rotated and swung. The control unit controls the cleaning brush to move until the foreign matter is within the cleaning range of the cleaning brush, and cleans the foreign matter after the cleaning liquid is sprayed on it.

[0010] Optionally, the cleaning device further comprises:

[0011] The rotatable wafer carrier drives the cleaned wafer to rotate so as to remove the cleaning liquid and foreign matter on the first surface of the wafer.

[0012] Optionally, the cleaning device and the rotatable wafer stage include:

[0013] A retractable ejector pin is disposed on the rotatable wafer stage and is used to drive the wafer on the rotatable wafer stage to rise before spraying the cleaning liquid, and to drive the wafer on the rotatable wafer stage to descend after cleaning the foreign matter after spraying the cleaning liquid;

[0014] A vacuum adsorption component, the vacuum adsorption component comprising:

[0015] a plurality of raised portions;

[0016] The vacuum adsorption hole is arranged on the top of each protrusion, and is used for adsorbing and fixing the wafer on the rotatable wafer carrier from the first surface of the wafer before the rotatable wafer carrier drives the wafer to rotate after cleaning.

[0017] Optionally, the cleaning device further comprises: a conveying unit, used to transfer the wafer to the retractable ejector pin;

[0018] The cleaning unit further includes: a clamping claw for fixing the wafer on the retractable ejector pin from the edge of the second surface of the wafer.

[0019] Optionally, the cleaning device further includes: a cup having a containing cavity, wherein the first surface of the wafer is located in the containing cavity in a rotating state, and the second surface of the wafer is located outside the containing cavity in a rotating state.

[0020] Optionally, the bottom of the accommodating chamber has a discharge port;

[0021] The cleaning device further includes: a collecting unit coupled to the discharge port and used for collecting the cleaning liquid and foreign matter discharged from the accommodating cavity.

[0022] Optionally, the detection unit includes:

[0023] A photoelectric coupler, configured to transmit an optical signal to the first side of the wafer;

[0024] A differential interferometer is used to receive a reflection signal of the optical signal reflected by the first surface of the wafer, and to distinguish a scattered signal in the reflection signal so as to identify the foreign matter and determine the position of the foreign matter on the wafer.

[0025] Correspondingly, the present application also provides a wafer cleaning method corresponding to the wafer cleaning device, the cleaning device comprising: a detection unit, a cleaning unit, and a control unit; the cleaning method comprising: the detection unit detecting whether there is foreign matter on the first side of the wafer, and determining the position of the foreign matter and the wafer; the control unit controlling the cleaning unit to directionally clean and remove the foreign matter according to the position.

[0026] Optionally, the cleaning method further comprises:

[0027] Before the detection unit detects whether there is a foreign object on the first surface of the wafer, the cleaning unit clamps the wafer.

[0028] Optionally, the cleaning unit comprises: a rotatable shower nozzle and a movable, rotating and oscillating cleaning brush;

[0029] The cleaning device further includes: a rotatable wafer stage;

[0030] The control unit controls the cleaning unit to clean and remove the foreign matter in a directional manner according to the position, comprising:

[0031] The control unit controls the shower nozzle to direct the showering direction toward the foreign matter in a cleaning state, and sprays cleaning liquid toward the foreign matter;

[0032] The control unit controls the movable, rotating and swinging cleaning brush to move until the foreign matter is within the cleaning range of the cleaning brush, and performs directional cleaning and removal of the foreign matter after the cleaning liquid is sprayed;

[0033] Placing the cleaned wafer on the rotatable wafer stage;

[0034] The rotatable wafer stage drives the cleaned wafer to rotate so as to remove the cleaning liquid and foreign matter on the first surface of the wafer.

[0035] Optionally, the cleaning method further comprises:

[0036] After the rotatable wafer stage drives the cleaned wafer to rotate to remove the cleaning fluid and foreign matter on the first surface of the wafer, the detection unit scans the first surface of the wafer after the cleaning fluid and foreign matter are removed to confirm whether there is foreign matter on the first surface of the wafer.

[0037] Compared with the prior art, the technical solution of the embodiment of the present application has the following advantages:

[0038] The wafer cleaning device shown in the present application includes: a detection unit, a cleaning unit, and a control unit; the detection unit is used to detect whether there is foreign matter on the first side of the wafer: if there is no foreign matter on the first side of the wafer, there is no need to clean the first side of the wafer, thereby improving production efficiency; if there is foreign matter on the first side of the wafer, the detection unit determines the position of the foreign matter on the wafer, and the control unit controls the cleaning unit to remove the foreign matter in a direction according to the position, without the need to clean the entire first side of the wafer, saving cleaning time for the first side of the wafer, thereby improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0040] Figure 1 is a schematic structural diagram of a wafer cleaning device according to this embodiment;

[0041] Figure 2 is a schematic diagram of the detection principle of the detection unit in the wafer cleaning device of this embodiment;

[0042] Figure 3 It is a flow chart of a cleaning method corresponding to the wafer cleaning device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0044] As can be seen from the background technology, in the actual process of manufacturing, there is a problem of wafer contamination, which leads to reduced production efficiency. The reasons for the reduced production efficiency are analyzed below.

[0045] Taking the semiconductor photolithography process as an example for analysis, before the wafer enters the photolithography process, foreign matter and other particles are likely to remain on the back of the wafer, causing the problem of wafer contamination. The impact of foreign matter remaining on the back of the wafer in the photolithography process is generally as follows: When the wafer is coated and developed, the unevenness caused by the presence of foreign matter on the back of the wafer will lead to uneven coating and development; during the exposure process, the wafer may also be out of focus due to the presence of foreign matter on the back of the wafer, and it will be detected as a focus failure by the photolithography machine. In serious cases, foreign matter may even be left on the workbench of the photolithography machine, causing batches of wafers to be affected. The above problems caused by the photolithography process will lead to wafer rework, greatly delay the production activities of chips, and lead to reduced production efficiency.

[0046] In addition, during the chip manufacturing process, the back of each wafer needs to be scrubbed regardless of whether there are foreign objects on the back of the wafer, which greatly reduces production efficiency.

[0047] In view of the above technical problems, an embodiment of the present invention provides a wafer cleaning device, which can improve production efficiency during the wafer cleaning process.

[0048] refer to Figure 1 and Figure 2 , Figure 1 is a schematic structural diagram of a wafer cleaning device according to this embodiment, Figure 2 Schematic diagram of the detection principle of the detection unit in the wafer cleaning device of this embodiment;

[0049] The cleaning device includes: a detection unit 200, used to detect whether there is a foreign object 101 on the first surface of the wafer 100, and to determine the position of the foreign object 101 on the wafer 100; a cleaning unit, used to clean the first surface of the wafer 100 where the foreign object 101 exists; and a control unit (not shown), which controls the cleaning unit to remove the foreign object 101 in a directional manner according to the position.

[0050] The cleaning device of the wafer 100 shown in the present application includes: a detection unit 200, a cleaning unit, and a control unit; the detection unit 200 is used to detect whether there is a foreign object 101 on the first surface of the wafer 100: if there is no foreign object 101 on the first surface of the wafer 100, there is no need to clean the first surface of the wafer 100, thereby improving production efficiency; if there is a foreign object 101 on the first surface of the wafer 100, the detection unit 200 determines the position of the foreign object 101 on the wafer 100, and the control unit controls the cleaning unit to directionally remove the foreign object 101 according to the position, without cleaning the entire first surface of the wafer 100, saving cleaning time of the first surface of the wafer 100, thereby improving production efficiency.

[0051] The wafer 100 has a first surface and a second surface opposite to each other, the first surface and the second surface can both be surfaces to be cleaned, and the first surface and / or the second surface are used to form semiconductor devices. In this embodiment, the first surface is the surface to be cleaned.

[0052] The cleaning device includes a detection unit 200 for detecting whether there is a foreign object 101 on the first surface of the wafer 100 and determining the position of the foreign object 101 on the wafer 100 .

[0053] It should be noted that when the detection unit 200 detects the presence of foreign matter 101 on the first surface of the wafer 100, the cleaning unit cleans the wafer 100. If the detection unit 200 detects that no foreign matter 101 is present on the first surface of the wafer 100, the cleaning unit does not need to clean the first surface of the wafer 100, thereby improving the cleaning efficiency of the wafer 100 and thus improving production efficiency.

[0054] refer to Figure 2 The detection unit 200 includes: a photoelectric coupler 201 and a differential interferometer 202.

[0055] The photoelectric coupler 201 is used to transmit an optical signal 203 to the first surface of the wafer 100; the differential interferometer 202 is used to receive a reflected signal 204 of the optical signal 203 reflected by the first surface of the wafer 100, and to distinguish a scattered signal 205 in the reflected signal 204, so as to identify the foreign object 101 and determine the position of the foreign object 101 on the wafer 100.

[0056] The photoelectric coupler 201 includes a light emitting device, such as a light emitting diode or a laser diode, and emits an optical signal 203 to the first surface of the wafer 100 through the light emitting device.

[0057] The foreign matter 101 is identified through the differential interferometer 202, that is, the shape, size, and height of the foreign matter 101 are identified, providing a basis for the process parameters of the subsequent cleaning device when cleaning the wafer 100, such as the amount of cleaning liquid, the cleaning time, the force of the movable rotating and swinging cleaning brush 301 during cleaning, etc., thereby improving the cleaning effect and cleaning efficiency.

[0058] The position of the foreign object 101 on the wafer 100 is determined by the differential interferometer 202, that is, for example, the position of the foreign object 101 relative to the center of the wafer 100, or the position of the foreign object 101 relative to the edge of the wafer 100, or the position of the foreign object 101 relative to any selected position on the wafer 100. The following beneficial effects are achieved:

[0059] First, when the cleaning device is cleaning, it is helpful to spray the cleaning liquid accurately to the location of the foreign matter 101, thereby improving the cleaning effect and cleaning efficiency.

[0060] Second, when the cleaning device is cleaning, it is beneficial for the control unit to control the movable rotating and swinging cleaning brush 301 to move to a point where the foreign object 101 is within the cleaning range of the movable rotating and swinging cleaning brush 301, and clean the foreign object 101 after the cleaning liquid is sprayed, thereby improving the cleaning effect and cleaning efficiency.

[0061] It should be noted that in the embodiment of the present invention, it is not limited to the use of a differential interferometer. For example, an image sensor or other device may be used in combination with an appropriate image recognition algorithm to determine the position of the foreign matter on the wafer.

[0062] The detection unit may emit the optical signal 203 to the entire first surface of the wafer 100 at one time, that is, the optical signal 203 covers the entire first surface of the wafer 100; or the first surface of the wafer 100 may be scanned step by step at a certain step by step. In this embodiment, the detection unit scans the first surface of the wafer 100 step by step at a certain step by step at a scanning method to detect whether there is a foreign object 101 on the first surface of the wafer 100.

[0063] The cleaning device includes: a cleaning unit for cleaning the first surface of the wafer 100 where foreign matter 101 exists.

[0064] refer to Figure 1 The cleaning unit comprises: a rotatable shower nozzle 300 for spraying cleaning liquid.

[0065] In this embodiment, the rotatable shower nozzle 300 is rotatable, and is used to adjust the angle between the rotatable shower nozzle 300 and the wafer 100, so as to spray the cleaning liquid to any position on the wafer 100. In other embodiments, the rotatable shower nozzle 300 is fixed.

[0066] The rotatable shower nozzle 300 mainly includes:

[0067] The nozzle body (not shown) is made of plastic, metal (such as stainless steel, brass) or other durable material.

[0068] Liquid outlet (not shown): located at the tip of the nozzle, can be designed with small holes or gaps of different shapes and sizes to form a liquid flow; those skilled in the art can set the shape and size of the liquid outlet according to actual needs, so that the liquid passes through the liquid outlet in a jet, spray, rain, etc. In this embodiment, the cleaning liquid passes through the liquid outlet in a jet shape to wash away the foreign matter 101.

[0069] Filter (not shown): used to prevent impurities in the liquid from clogging the liquid outlet.

[0070] Regulating valve (not shown): used to control the force of the cleaning liquid sprayed onto the foreign object 101 .

[0071] The foreign matter 101 includes one or more of fibers, organic matter, and metal particles. The corresponding cleaning solution should be selected according to the type of organic matter. In this embodiment, the foreign matter 101 is organic matter, and the cleaning solution corresponding to the organic matter includes one or more of acetone, isopropyl alcohol, methyl pyrrolidone, and dimethyl sulfoxide.

[0072] It should be noted that, in this embodiment, the detection unit 200 can detect the type of foreign matter 101 on the first surface of the wafer 100. According to the type of foreign matter 101, the control unit controls the rotatable shower nozzle 300 to spray the corresponding cleaning liquid toward the foreign matter 101 in the shower direction in the cleaning state, thereby improving the cleaning effect of the wafer 100. For example, if the foreign matter 101 is a metal particle, the control unit controls the rotatable shower nozzle 300 to spray the cleaning liquid corresponding to the metal particle to the foreign matter 101; for another example, if the foreign matter 101 is an organic matter, the control unit controls the rotatable shower nozzle 300 to spray the cleaning liquid corresponding to the organic matter to the foreign matter 101.

[0073] Continue to refer Figure 1 The cleaning unit comprises a cleaning brush 301 which can be moved, rotated and swung.

[0074] In this embodiment, the movable, rotatable and oscillating cleaning brush 301 is configured to be movable, rotatable and oscillating.

[0075] The movable, rotatable and oscillating cleaning brush 301 is configured to be movable. In some embodiments, the movable, rotatable and oscillating cleaning brush 301 can move relative to the wafer 100 to facilitate cleaning of foreign matter 101 at any position on the first surface of the wafer 100 .

[0076] The movable, rotatable and oscillating cleaning brush 301 is configured to be rotatable and oscillating. In some embodiments, during cleaning, the movable, rotatable and oscillating cleaning brush 301 rotates and oscillates on the foreign matter 101 , which is beneficial for peeling the foreign matter 101 from the first surface of the wafer 100 .

[0077] The cleaning device includes: a control unit, which controls the cleaning unit to remove the foreign matter 101 in a directional manner according to the position.

[0078] In some embodiments, the control unit controls the shower direction of the rotatable shower nozzle 300 in the cleaning state to be toward the foreign object 101 and sprays the corresponding cleaning liquid according to the position of the foreign object 101 on the wafer 100 detected by the detection unit 200; the control unit also controls the movable rotating and swinging cleaning brush 301 to move until the foreign object 101 is within the cleaning range of the movable rotating and swinging cleaning brush 301, so that the movable rotating and swinging cleaning brush 301 rotates and swings on the foreign object 101 to clean the foreign object 101 after spraying the cleaning liquid.

[0079] The cleaning unit is controlled to remove the foreign matter 101 in a directional manner, that is, the cleaning unit only performs cleaning operations on the positions where the detection unit 200 detects the presence of foreign matter 101, while the positions on the first surface of the wafer 100 where no foreign matter 101 appears do not need to be cleaned, thereby improving the cleaning efficiency of the wafer 100 and thus improving production efficiency.

[0080] The cleaning device includes a rotatable wafer carrier 302 .

[0081] The rotatable wafer stage 302 is used to drive the cleaned wafer 100 to rotate so as to remove the cleaning liquid and foreign matter 101 on the first surface of the wafer 100 , thereby improving the cleaning effect of the wafer 100 and thus improving the production efficiency.

[0082] The material of the rotatable wafer stage 302 includes: metal material (such as stainless steel, aluminum, etc.) or anti-static plastic material (such as polycarbonate, electro-polypropylene, acrylic, etc.); the rotatable wafer stage 302 is a cylindrical structure, and the cylindrical structure includes any of the following: a cylindrical structure, an elliptical cylindrical structure, a square cylindrical structure, etc. The embodiment of the present application does not limit the material and specific cylindrical structure of the rotatable wafer stage 302, and those skilled in the art can adjust the settings according to actual conditions. In this embodiment, the material of the rotatable wafer stage 302 is metal, and the rotatable wafer stage 302 is a cylindrical structure.

[0083] The rotatable wafer stage 302 is used to rotate the cleaned wafer 100, and remove the cleaning liquid and foreign matter 101 on the first surface of the wafer 100 by the principle of centrifugal force. In other embodiments, the rotatable wafer stage 302 is also used to rotate the wafer 100 before cleaning.

[0084] It should be noted that the rotatable wafer stage 302 can rotate in a clockwise direction or in a counterclockwise direction. In this embodiment, the rotatable wafer stage 302 rotates in a clockwise direction. In other embodiments, along a direction perpendicular to the first surface of the wafer 100, the rotatable wafer stage 302 can move closer to or away from the cleaning unit.

[0085] The geometric center of the wafer 100 after cleaning is on the same axis as the geometric center of the rotatable wafer carrier 302, and the axis is perpendicular to the first surface of the wafer 100, which has the following beneficial effects: when the rotatable wafer carrier 302 drives the wafer 100 after cleaning to rotate, the probability of the wafer 100 detaching from the rotatable wafer carrier 302 can be reduced.

[0086] It should be noted that appropriately reducing the rotation speed of the rotatable wafer stage 302 is conducive to reducing the probability of the wafer 100 detaching from the rotatable wafer stage 302, and appropriately increasing the rotation speed of the rotatable wafer stage 302 is conducive to removing the cleaning liquid and foreign matter 101 on the first surface of the wafer 100, improving the cleaning effect of the wafer 100, and thus improving production efficiency. Therefore, in this embodiment, the rotation speed of the rotatable wafer stage 302 is within the range of greater than or equal to 100 rpm and less than or equal to 150 rpm.

[0087] The size of the rotatable wafer stage 302 is smaller than the size of the wafer 100, or the size of the rotatable wafer stage 302 is equal to the size of the wafer 100, or the size of the rotatable wafer stage 302 is larger than the size of the wafer 100. In this embodiment, the size of the rotatable wafer stage 302 is smaller than the size of the wafer 100, which has the following beneficial effects: when the rotatable wafer stage 302 drives the cleaned wafer 100 to rotate, the probability of the cleaned cleaning liquid and foreign matter 101 splashing onto the rotatable wafer stage 302 can be reduced, thereby reducing the risk of the cleaned cleaning liquid and foreign matter 101 causing secondary contamination to the subsequent wafer 100 to be cleaned.

[0088] The rotatable wafer stage 302 includes a retractable ejector pin 303 .

[0089] The retractable ejector pin 303 is disposed on the rotatable wafer stage 302, and is used to drive the wafer 100 on the rotatable wafer stage 302 to rise before spraying the cleaning liquid, and to drive the wafer 100 on the rotatable wafer stage 302 to descend after cleaning the foreign matter 101 after spraying the cleaning liquid.

[0090] The wafer 100 on the rotatable wafer carrier 302 is controlled to rise, that is, the wafer 100 before being sprayed with the cleaning liquid is located on the retractable ejector pin 303, the retractable ejector pin 303 rises to transfer the wafer 100 to a position where the cleaning unit can clean it, and the retractable ejector pin 303 descends to facilitate the rotatable shower nozzle 300 to spray the cleaning liquid on the first surface of the wafer 100, and the movable, rotating and swinging cleaning brush 301 cleans the foreign matter 101 after the cleaning liquid is sprayed.

[0091] The wafer 100 on the rotatable wafer stage 302 is controlled to descend, that is, after the movable, rotating and swinging cleaning brush 301 cleans the foreign matter 101 sprayed with the cleaning solution, the retractable ejector pin 303 rises to place the wafer 100 on the retractable ejector pin 303, and the retractable ejector pin 303 descends, driving the wafer 100 to descend onto the rotatable wafer stage 302.

[0092] It should be noted that the retractable ejector pin 303 can be disposed inside the stage surface of the rotatable wafer stage 302 or outside the stage surface of the rotatable wafer stage 302. In this embodiment, the retractable ejector pin 303 can be disposed inside the stage surface of the rotatable wafer stage 302.

[0093] The number of the retractable ejector pins 303 is greater than or equal to 3, and the retractable ejector pins 303 are evenly or unevenly distributed on the rotatable wafer stage 302. In this embodiment, the number of the retractable ejector pins 303 is 3, and the retractable ejector pins 303 are evenly distributed on the rotatable wafer stage 302. In other embodiments, the retractable ejector pins 303 may be eliminated, and the wafer 100 is transferred to a position where the cleaning unit can clean by moving the rotatable wafer stage 302 along a direction perpendicular to the first surface of the wafer 100 to approach the cleaning unit.

[0094] The material of the retractable ejector pin 303 includes: metal material (such as stainless steel material, aluminum material, etc.) or anti-static plastic material (such as polycarbonate, electro-polypropylene, acrylic, etc.); the retractable ejector pin 303 is a columnar structure, and the columnar structure includes any of the following: a cylindrical structure, an elliptical cylindrical structure, a square cylindrical structure, etc. The embodiment of the present application does not limit the material and specific columnar structure of the retractable ejector pin 303, and those skilled in the art can adjust the settings according to actual conditions. In this embodiment, the material of the retractable ejector pin 303 is metal, and the retractable ejector pin 303 is a cylindrical structure.

[0095] In this embodiment, the retractable ejector pin 303 adsorbs the first surface of the wafer 100 by vacuum adsorption, so that the wafer 100 rises and falls relative to the rotatable wafer stage 302. In other embodiments, the retractable ejector pin 303 may not be provided with vacuum adsorption.

[0096] In this embodiment, at the contact point between the retractable ejector pin 303 and the first surface of the wafer 100 , the retractable ejector pin 303 is provided with a rubber gasket to reduce the risk of the retractable ejector pin 303 scratching the wafer 100 .

[0097] It should be noted that the retractable ejector pin 303 can be retracted below the carrier surface of the rotatable wafer carrier 302 .

[0098] The rotatable wafer stage 302 includes a vacuum adsorption component (not shown).

[0099] The vacuum adsorption assembly is used to adsorb and fix the wafer 100 on the rotatable wafer carrier 302 when the rotatable wafer carrier 302 rotates, thereby reducing the probability of the wafer 100 detaching from the rotatable wafer carrier 302 and improving production efficiency.

[0100] The vacuum adsorption assembly includes: a plurality of protrusions (not shown); and vacuum adsorption holes (not shown), which are arranged on the top of each protrusion. The vacuum adsorption holes are used to adsorb and fix the wafer 100 on the rotatable wafer stage 302 from the first surface of the wafer 100 before the rotatable wafer stage 302 drives the wafer 100 after cleaning to rotate. When the rotatable wafer stage 302 rotates, the probability of the wafer 100 detaching from the rotatable wafer stage 302 is reduced, thereby improving production efficiency.

[0101] In this embodiment, the number of the protrusions is 3, and each protrusion is provided with a vacuum adsorption hole.

[0102] The material of the raised portion includes: metal material (such as stainless steel, aluminum, etc.) or anti-static plastic material (such as polycarbonate, electro-polypropylene, acrylic, etc.); the raised portion is a column structure, and the column structure includes any of the following: a cylindrical structure, an elliptical cylindrical structure, a square cylindrical structure, etc. The embodiment of the present application does not limit the material and specific column structure of the raised portion, and those skilled in the art can adjust the settings according to actual conditions. In this embodiment, the material of the raised portion is metal, and the raised portion is a cylindrical structure.

[0103] It should be noted that the height of the protrusion is lower than the maximum height that the retractable ejector pin 303 can rise to.

[0104] The protrusion can be mounted on the rotatable wafer stage 302, or can be integrally formed with the rotatable wafer stage 302. The protrusion can also be arranged in a retractable state relative to the rotatable wafer stage 302. In this embodiment, the protrusion is integrally formed with the rotatable wafer stage 302.

[0105] The cleaning device comprises: a conveying unit (not shown)

[0106] The conveying unit is used to transfer the wafer 100 to the retractable ejector pin 303 .

[0107] The conveying unit includes: a mechanical arm, a support frame for carrying the mechanical arm, a motor for controlling the movement of the mechanical arm, and a conveyor belt connecting the motor and the mechanical arm.

[0108] The wafer 100 may be placed on the conveying unit manually or automatically.

[0109] After the conveying unit transfers the wafer 100 to the retractable ejector pin 303, the conveying unit automatically returns to its position. When the detection unit 200 detects that the cleanliness of the first surface of the wafer 100 meets the production requirements, or when the detection unit 200 detects that there is no foreign matter 101 on the first surface of the wafer 100, the conveying unit will take the wafer 100 out of the cleaning unit.

[0110] The cleaning unit comprises: a clamping claw.

[0111] The clamp is used to fix the wafer 100 on the retractable ejector pin 303 from the edge of the second surface of the wafer 100 .

[0112] In some embodiments, the retractable ejector pin 303 drives the wafer 100 to rise to the clamping position, the clamping claw clamps the edge of the second surface of the wafer 100 and fixes the wafer 100, and the retractable ejector pin 303 descends and retracts to the rotatable wafer stage 302. During the cleaning unit cleaning the wafer 100, the clamping claw clamps and fixes the wafer, which can reduce the risk of the wafer 100 falling off the clamping claw. In other embodiments, the clamping claw clamps the side wall of the wafer 100 to reduce the film layer of the semiconductor device on the surface of the clamping claw wafer 100.

[0113] The material of the clamp includes: metal material (such as stainless steel, aluminum, etc.) or anti-static plastic material (such as polycarbonate, polypropylene, acrylic, etc.); the clamp is a column structure, and the column structure includes any of the following: cylindrical structure, elliptical cylindrical structure, square cylindrical structure, etc. The embodiment of the present application does not limit the material and specific column structure of the clamp, and those skilled in the art can adjust the settings according to actual conditions. In this embodiment, the material of the clamp is metal, and the clamp is a square cylindrical structure.

[0114] There are multiple clamping jaws. In this embodiment, there are four clamping jaws, namely a first clamping jaw 401 , a second clamping jaw 402 , a third clamping jaw 403 , and a fourth clamping jaw 404 .

[0115] The cleaning device comprises: a cup 500 having a containing cavity.

[0116] The cup 500 has a receiving cavity for receiving the rotatable wafer carrier 302 and the wafer 100 , so as to prevent the rotatable wafer carrier 302 from driving the wafer 100 to rotate and splashing the cleaning liquid and foreign matter 101 , thereby reducing the probability of secondary contamination of the wafer 100 .

[0117] It should be noted that the first surface of the wafer 100 is located in the accommodating cavity in the rotated state, and the second surface of the wafer 100 is located outside the accommodating cavity in the rotated state, thereby reducing the probability of the cleaning liquid and foreign matter 101 cleaned from the first surface of the wafer 100 splashing to the second surface of the wafer 100 and causing contamination to the second surface of the wafer 100, thereby improving production efficiency.

[0118] The material of the cup 500 includes: metal material (such as stainless steel, aluminum, etc.) or anti-static plastic material (such as polycarbonate, electro-polypropylene, acrylic, etc.); the cup 500 is an annular cylindrical structure, and the annular cylindrical structure includes any of the following: an annular cylindrical structure, an annular elliptical cylindrical structure, an annular square cylindrical structure, etc. The embodiment of the present application does not limit the material of the raised portion and the specific annular cylindrical structure, and those skilled in the art can adjust the settings according to actual conditions. In this embodiment, the material of the cup 500 is acrylic, and the raised portion is an annular cylindrical structure.

[0119] The bottom of the accommodating chamber has a discharge port; the cleaning device also includes: a storage unit (not shown), coupled to the discharge port, for collecting the cleaning liquid and foreign matter 101 discharged from the accommodating chamber, thereby reducing the probability of secondary contamination of the wafer 100.

[0120] The storage unit comprises:

[0121] The exhaust sub-unit is used to suck the cleaning liquid and foreign matter 101 cleaned out when the rotatable wafer carrier 302 drives the wafer 100 to rotate, thereby improving the cleaning efficiency of the wafer 100 and thus improving the production efficiency.

[0122] The storage box is used to store the cleaning liquid and foreign matter 101 sucked out by the exhaust sub-unit.

[0123] It should be noted that the cleaning device includes: multiple motors. In this embodiment, the control unit controls the rise and fall of the retractable ejector pin 303, the transmission unit transmits the wafer 100, the rotation of the rotatable wafer carrier 302, the rotation and movement of the rotatable shower nozzle 300, the movement, rotation and swing of the movable, rotating and swinging cleaning brush 301, and the detection unit detects foreign matter on the wafer, etc. through multiple motors. They are not listed one by one here, but they do not serve as a limitation to the present application.

[0124] In order to solve the technical problem, the present invention also provides a cleaning method for a wafer 100 corresponding to the cleaning device.

[0125] refer to Figure 1 and Figure 2 The cleaning device includes: a detection unit 200, a cleaning unit, a control unit, a rotatable wafer carrier 302, and a transmission unit.

[0126] The cleaning unit comprises: a rotatable shower nozzle 300, a movable, rotatable and swingable cleaning brush 301, and a clamping claw; the rotatable wafer carrier 302 comprises: a retractable ejector pin 303, and a protruding portion provided with a vacuum adsorption hole.

[0127] Regarding the relevant structure of the above-mentioned cleaning device, as well as the relevant structure of the cleaning device mentioned in the subsequent description of the cleaning method, reference can be made to the structural description of the cleaning device in the aforementioned embodiment, which will not be described again here.

[0128] refer to Figure 3 , is a flow chart of a cleaning method corresponding to the wafer cleaning device according to an embodiment of the present invention.

[0129] refer to Figure 3 , combined with Figure 1 and Figure 2 , the cleaning method mainly comprises the following steps:

[0130] Step S11: the cleaning unit clamps the wafer.

[0131] Before the detection unit 200 detects whether there is a foreign object 101 on the first surface of the wafer 100, the cleaning unit clamps the wafer 100, mainly including the following sub-steps:

[0132] The wafer 100 is loaded onto the conveying unit manually or by automatic equipment, and the first surface of the wafer 100 contacts the conveying unit.

[0133] The transfer unit transfers the wafer 100 to the raised retractable ejector pins 303 .

[0134] The transfer unit returns to its original position, that is, the transfer unit returns to the position where the wafer 100 is loaded on the transfer unit.

[0135] The retractable ejector pin 303 carrying the wafer 100 continues to rise to the position of the clamp, and the first clamp 401, the second clamp 402, the third clamp 403, and the fourth clamp 404 jointly clamp the second surface edge of the wafer 100, or jointly clamp the side wall of the wafer 100 to clamp and fix the wafer 100 on the first clamp 401, the second clamp 402, the third clamp 403, and the fourth clamp 404, that is, the cleaning unit clamps the wafer 100.

[0136] The retractable ejector pin 303 is returned to its original position. In some embodiments, the retractable ejector pin 303 is lowered into the rotatable wafer stage 302 .

[0137] Step S12: the detection unit detects whether there is a foreign object on the first surface of the wafer, and determines the position of the foreign object and the wafer.

[0138] The detection unit 200 includes: a photoelectric coupler 201 and a differential interferometer 202 .

[0139] The photoelectric coupler 201 transmits an optical signal 203 to the first surface of the wafer 100 , and the differential interferometer 202 receives a reflected signal 204 of the optical signal 203 reflected by the first surface of the wafer 100 , and distinguishes a scattered signal 205 in the reflected signal 204 to identify whether there is a foreign object 101 on the first surface of the wafer 100 .

[0140] If there is no foreign matter 101 on the first surface of the wafer 100 , there is no need to clean the wafer 100 , and the wafer 100 can be directly sent to the next process, thereby improving production efficiency.

[0141] If there is a foreign object 101 on the first surface of the wafer 100, the differential interferometer 202 will determine the shape, size, type, and position of the foreign object 101 relative to the wafer 100, and feed back information about the shape, size, type, and position of the foreign object 101 to the control unit.

[0142] Step S13: the control unit controls the cleaning unit to directionally clean and remove the foreign matter according to the position.

[0143] The control unit controls the cleaning unit to directionally clean and remove the foreign matter 101 according to the position, comprising:

[0144] The control unit controls the rotatable shower nozzle 300 to direct a shower direction toward the foreign object 101 in a cleaning state, and sprays a cleaning liquid toward the foreign object 101 .

[0145] In some embodiments, the control unit controls the rotatable shower nozzle 300 to spray the foreign object 101 in the cleaning state. The control unit automatically selects the type of cleaning liquid, the amount of cleaning liquid, the spraying time of the cleaning liquid, the impact force of the cleaning liquid sprayed onto the foreign object 101, etc. according to the foreign object 101 information feedback from the detection unit 200. The control unit controls the rotatable shower nozzle 300 to spray the cleaning liquid onto the foreign object 101.

[0146] The control unit controls the movable, rotating and swinging cleaning brush 301 to move to a point where the foreign matter 101 is within the cleaning range of the movable, rotating and swinging cleaning brush 301 , and performs directional cleaning and removal of the foreign matter 101 after the cleaning liquid is sprayed.

[0147] In some embodiments, the control unit controls the movable rotating and swinging cleaning brush 301 to move to the foreign object 101. The control unit automatically selects the rotation speed, swing speed, swing amplitude, cleaning force, cleaning time, etc. of the movable rotating and swinging cleaning brush 301 according to the foreign object 101 information feedback from the detection unit 200. The control unit controls the movable rotating and swinging cleaning brush 301 to carry out directional cleaning and removal of the foreign object 101 after spraying the cleaning liquid.

[0148] It should be noted that the directional cleaning and removal of the foreign matter 101 after the cleaning liquid is sprayed means that the cleaning device only cleans the foreign matter 101 detected by the detection unit. The cleaning and removal means that the foreign matter 101 physically or chemically reacts with the cleaning liquid and dissolves in the cleaning liquid, or the foreign matter 101 is mixed in the cleaning liquid.

[0149] The cleaned wafer is placed on the rotatable wafer stage.

[0150] In some embodiments, after the foreign matter 101 is directionally cleaned and removed after being sprayed with cleaning liquid, the retractable ejector pin 303 is raised to the first side of the wafer 100, the clamp releases the wafer 100, and the wafer 100 is placed on the raised retractable ejector pin 303. The retractable ejector pin 303 descends, and the cleaned wafer 100 is placed on the rotatable wafer stage 302. The vacuum adsorption holes on the raised part of the vacuum adsorption assembly on the rotatable wafer stage 302 adsorb and fix the wafer 100 on the rotatable wafer stage 302, thereby reducing the probability of the wafer 100 detaching from the rotatable wafer stage 302 when the rotatable wafer stage 302 drives the wafer 100 to rotate.

[0151] The rotatable wafer stage drives the cleaned wafer to rotate so as to remove the cleaning liquid and foreign matter on the first surface of the wafer.

[0152] In some embodiments, the rotatable wafer carrier 302 drives the cleaned wafer 100 to rotate, and through the principle of centrifugal force and the suction effect of the exhaust sub-unit, the cleaning liquid and foreign matter 101 located on the first surface of the wafer 100 are thrown out into the cup 500 with a receiving cavity, and then the cleaning liquid and foreign matter 101 are discharged into the receiving unit from the discharge port at the bottom of the receiving cavity.

[0153] It should be noted that the first surface of the wafer 100 is located in the accommodating cavity in the rotated state, and the second surface of the wafer 100 is located outside the accommodating cavity in the rotated state, thereby reducing the probability of the cleaning liquid and foreign matter 101 cleaned from the first surface of the wafer 100 splashing to the second surface of the wafer 100 and causing contamination to the second surface of the wafer 100, thereby improving production efficiency.

[0154] It should be noted that appropriately reducing the rotation speed of the rotatable wafer stage 302 is conducive to reducing the probability of the wafer 100 detaching from the rotatable wafer stage 302, and appropriately increasing the rotation speed of the rotatable wafer stage 302 is conducive to removing the cleaning liquid and foreign matter 101 on the first surface of the wafer 100, improving the cleaning effect of the wafer 100, and thus improving production efficiency. Therefore, in this embodiment, the rotation speed of the rotatable wafer stage 302 is within the range of greater than or equal to 100 rpm and less than or equal to 150 rpm.

[0155] Step S14: the detection unit scans the first surface of the wafer after the cleaning liquid and foreign matter are removed to confirm whether there is foreign matter on the first surface of the wafer.

[0156] In some embodiments, after the rotatable wafer stage 302 drives the cleaned wafer 100 to rotate to remove the cleaning fluid and foreign matter 101 on the first surface of the wafer 100, the vacuum adsorption of the raised portion on the rotatable wafer stage 302 is turned off, the retractable ejector pin 303 rises to the first surface of the wafer 100, and the wafer 100 is placed on the clamp to be clamped and fixed by the clamp. The detection unit 200 scans the first surface of the wafer 100 after the cleaning fluid and foreign matter 101 are removed to confirm whether there is foreign matter 101 on the first surface of the wafer 100. If it is confirmed that there is foreign matter 101 on the first surface of the wafer 100, steps S12 to S14 are repeated. If it is confirmed that there is no foreign matter 101 on the first surface of the wafer 100, the wafer 100 is sent to the next process.

[0157] It should be understood that the term "and / or" in this article is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article indicates that the associated objects before and after are in an "or" relationship.

[0158] The "plurality" appearing in the embodiments of the present application refers to two or more.

[0159] The first, second, etc. descriptions appearing in the embodiments of the present application are only used for illustration and distinction of the description objects. There is no order, nor do they indicate any special limitation on the number of devices in the embodiments of the present application, and cannot constitute any limitation on the embodiments of the present application.

[0160] It should be pointed out that the serial numbers of the steps in this embodiment do not limit the execution order of the steps.

[0161] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. A wafer cleaning device, characterized in that: The wafer has a first surface and a second surface opposite to each other, the first surface being a surface to be cleaned; The cleaning device comprises: a detection unit, used to detect whether there is a foreign object on the first surface of the wafer, and to determine the position of the foreign object on the wafer; A cleaning unit, used for cleaning the first side of the wafer where foreign matter exists; The control unit controls the cleaning unit to remove the foreign matter in a directional manner according to the position.

2. The cleaning device according to claim 1, characterized in that The cleaning unit comprises: Rotatable shower nozzle for spraying cleaning fluid; The control unit controls the shower nozzle to spray toward the foreign matter in a cleaning state; A cleaning brush can be moved, rotated and swung. The control unit controls the cleaning brush to move until the foreign matter is within the cleaning range of the cleaning brush, and cleans the foreign matter after the cleaning liquid is sprayed on it.

3. The cleaning device according to claim 2, characterized in that The cleaning device further comprises: The rotatable wafer stage drives the cleaned wafer to rotate so as to remove the cleaning liquid and foreign matter on the first surface of the wafer.

4. The cleaning device according to claim 3, characterized in that The rotatable wafer stage comprises: A retractable ejector pin is disposed on the rotatable wafer stage and is used to drive the wafer on the rotatable wafer stage to rise before spraying the cleaning liquid, and to drive the wafer on the rotatable wafer stage to descend after cleaning the foreign matter after spraying the cleaning liquid; A vacuum adsorption component, the vacuum adsorption component comprising: a plurality of raised portions; The vacuum adsorption hole is arranged on the top of each protrusion, and is used for adsorbing and fixing the wafer on the rotatable wafer carrier from the first surface of the wafer before the rotatable wafer carrier drives the wafer to rotate after cleaning.

5. The cleaning device according to claim 4, characterized in that Also includes: A conveying unit, used for transferring the wafer to the retractable ejector pin; The cleaning unit further includes: a clamping claw for fixing the wafer on the retractable ejector pin from the edge of the second surface of the wafer.

6. The cleaning device according to claim 3, characterized in that: Also includes: The cup has a containing cavity, wherein the first surface of the wafer is located in the containing cavity in a rotating state, and the second surface of the wafer is located outside the containing cavity in a rotating state.

7. The cleaning device according to claim 6, characterized in that The bottom of the accommodating chamber is provided with a discharge port; The cleaning device further includes: a collecting unit coupled to the discharge port and used for collecting the cleaning liquid and foreign matter discharged from the accommodating cavity.

8. The cleaning device according to claim 1, characterized in that The detection unit comprises: A photoelectric coupler, configured to transmit an optical signal to the first side of the wafer; A differential interferometer is used to receive a reflection signal of the optical signal reflected by the first surface of the wafer, and to distinguish a scattered signal in the reflection signal so as to identify the foreign matter and determine the position of the foreign matter on the wafer.

9. A wafer cleaning method, applied to a wafer cleaning device, characterized in that: The cleaning device comprises: a detection unit, a cleaning unit, and a control unit; The cleaning method comprises: The detection unit detects whether there is a foreign object on the first surface of the wafer, and determines the position of the foreign object and the wafer; The control unit controls the cleaning unit to clean and remove the foreign matter in a directional manner according to the position.

10. The cleaning method according to claim 9, characterized in that: The cleaning method further comprises: Before the detection unit detects whether there is a foreign object on the first surface of the wafer, the cleaning unit clamps the wafer.

11. The cleaning method according to claim 9, characterized in that: The cleaning unit comprises: a rotatable shower nozzle and a movable, rotating and swinging cleaning brush; The cleaning device further includes: a rotatable wafer stage; The control unit controls the cleaning unit to clean and remove the foreign matter in a directional manner according to the position, comprising: The control unit controls the shower nozzle to direct the showering direction toward the foreign matter in a cleaning state, and sprays cleaning liquid toward the foreign matter; The control unit controls the movable, rotating and swinging cleaning brush to move until the foreign matter is within the cleaning range of the cleaning brush, and performs directional cleaning and removal of the foreign matter after the cleaning liquid is sprayed; Placing the cleaned wafer on the rotatable wafer stage; The rotatable wafer stage drives the cleaned wafer to rotate so as to remove the cleaning liquid and foreign matter on the first surface of the wafer.

12. The cleaning method according to claim 11, characterized in that: The cleaning method further comprises: After the rotatable wafer stage drives the cleaned wafer to rotate to remove the cleaning fluid and foreign matter on the first surface of the wafer, the detection unit scans the first surface of the wafer after the cleaning fluid and foreign matter are removed to confirm whether there is foreign matter on the first surface of the wafer.

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