Two-fluid atomization spraying cleaning method and device

Abstract

The invention provides a two-fluid atomization spraying cleaning method and device, and belongs to the technical field of semiconductor cleaning, and the two-fluid atomization spraying cleaning method comprises the following steps: S10, rotating a wafer, and spraying liquid at the top of the wafer to form a layer of liquid film on the surface of the wafer; s20, an air inlet pipeline is opened, liquid and gas are sprayed out at the same time, and atomized particles are formed and sprayed into the liquid film; and S30, the two-fluid nozzle swings between the two edges in a reciprocating mode through the center of the wafer, and the swinging speed of the two-fluid nozzle is gradually increased in the direction close to the circle center of the wafer till cleaning is completed. The two-fluid atomization spraying cleaning device is used for implementing the two-fluid atomization spraying cleaning method and comprises a cleaning box, a rotating platform and a spraying arm, and the rotating platform is provided with a clamping seat used for fixing a wafer; the spraying arm comprises a rotating arm, a swing arm fixedly arranged at the top of the rotating arm and a nozzle assembly fixedly arranged at the free end of the swing arm.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductor cleaning, and in particular relates to a two-fluid atomization spray cleaning method and device. Background Art

[0002] Two-fluid atomization jet cleaning is a cleaning method that uses a two-fluid atomization nozzle, which is often used to clean wafers. The two-fluid nozzle has one compressed air and one liquid, and the interaction between liquid and gas produces an atomization effect to clean the wafer surface.

[0003] During the actual cleaning process, the wafer rotates and the two-fluid nozzle needs to swing back and forth from the outer edge of the wafer to the center to ensure the cleaning effect of the wafer. However, in this process, the linear speeds of different positions from the edge to the center of the wafer are different, while the swinging speed of the two-fluid nozzle is constant. Therefore, when the two fluids pass through different positions on the wafer, liquid splashing is more likely to occur as it is farther away from the center of the wafer. In severe cases, the liquid film on the wafer will rupture and the wafer cannot always remain wet. Summary of the invention

[0004] The embodiment of the present invention provides a two-fluid atomization spray cleaning method and device, which aims to solve the technical problem that during the existing two-fluid atomization spray cleaning process, the two-fluid nozzle swings to different positions of the wafer, and as the linear speed of the wafer at different positions changes, it is easy to cause liquid splashing or wafer liquid film rupture and the wafer cannot always be kept in a wet state.

[0005] In a first aspect, an embodiment of the present invention provides a two-fluid atomization spray cleaning method, comprising the following steps: S10: rotating the wafer and spraying liquid on the top of the wafer to form a liquid film on the surface of the wafer; S20: opening the air inlet pipeline, and the liquid and gas are sprayed out simultaneously to form atomized particles that are injected into the liquid film; S30: The two-fluid nozzle swings back and forth between the two edges through the center of the wafer, and the swinging speed of the two-fluid nozzle gradually increases in a direction approaching the center of the wafer until cleaning is completed.

[0006] In combination with the first aspect, in a possible implementation manner, the spraying liquid is a mixture of one or more of ultrapure water, hydrofluoric acid solution, ammonia water and hydrogen peroxide solution.

[0007] In combination with the first aspect, in a possible implementation manner, the air intake pipeline contains nitrogen, argon or carbon dioxide.

[0008] In combination with the first aspect, in a possible implementation, the top surface of the wafer has a first cleaning area located in the center and a second cleaning area located in an outer ring of the first cleaning area, and the two-fluid nozzle swings in the first cleaning area at a first speed and swings in the second cleaning area at a second speed, and the second speed is less than the first speed.

[0009] In combination with the first aspect, in a possible implementation manner, the ratio of the outer diameter of the second cleaning zone to the diameter of the wafer is 5:6-9:10.

[0010] In combination with the first aspect, in a possible implementation, the size of the wafer is 12 inches, the radius of the first cleaning zone is 90 mm, the first speed is 50 mm / s, the outer edge radius of the second cleaning zone is 130 mm, and the second speed is 30 mm / s.

[0011] Compared with the prior art, the solution shown in the embodiment of the present application is that during the cleaning process, high-speed gas and high-speed liquid interact with each other to generate atomized particles for cleaning that are sprayed on the wafer. Since the two-fluid nozzle needs to swing on the top of the wafer, on the cleaning surface of the wafer, the smaller the linear velocity is near the center of the wafer, and the greater the swing speed of the two-fluid nozzle is near the center of the wafer, the splashing of the high-speed liquid flow can be significantly improved, the wafer surface can be kept moist at all times, and the cleaning quality and efficiency of the wafer can be improved.

[0012] In a second aspect, an embodiment of the present invention further provides a two-fluid atomizing spray cleaning device, which is used to implement the above two-fluid atomizing spray cleaning method, comprising: A rotating platform is disposed in the cleaning box, and a clamping seat for fixing the wafer is provided on the rotating platform; A spray arm is arranged in the cleaning box, and comprises a rotating arm, a swing arm fixedly arranged on the top of the rotating arm, and a nozzle assembly fixedly arranged on the free end of the swing arm. The rotating arm is used to drive the swing arm to rotate and lift.

[0013] In combination with the second aspect, in a possible implementation, the spray arm further includes: Bracket; A lifting plate, slidably connected to the bracket in an up-and-down direction; A lifting cylinder, the piston rod of which is fixedly connected to the lifting plate; The rotating motor is fixed on the top of the lifting plate, and the output shaft of the rotating motor is arranged up and down and fixedly connected to the bottom end of the rotating arm.

[0014] In conjunction with the second aspect, in a possible implementation, the nozzle assembly includes: A main body, comprising a gas pipeline, a liquid pipeline and a nozzle, wherein a plurality of gas pipelines are evenly arranged around the axial direction of the liquid pipeline, and the nozzles are respectively connected with the plurality of gas pipelines and the liquid pipelines; A guide component is arranged in the nozzle, and is provided with a gas outlet area and a liquid outlet area alternately arranged axially around the liquid pipeline. The gas outlet area corresponds to the gas pipeline one by one and has a gas outlet hole. The liquid outlet area is a liquid outlet pipe connected to the liquid pipeline, and the liquid outlet pipe is open at one end away from the liquid pipeline.

[0015] In combination with the second aspect, in a possible implementation, the side wall of the liquid outlet pipe is provided with a plurality of liquid outlet holes spaced apart along its axial direction, and the axial angle between the liquid outlet holes and the liquid pipeline is 20° to 70°.

[0016] The scheme shown in the embodiment of the present application, compared with the prior art, fixes the wafer on the clamping seat, drives the clamping seat to rotate by the rotating platform, and then realizes the rotation of the wafer, and the rotating arm drives the swing arm to rotate until the nozzle assembly is above the center of the wafer, and adjusts the distance between the nozzle assembly and the wafer surface by lifting, opens the nozzle assembly to spray liquid until a liquid film is formed on the surface of the wafer, and then the nozzle assembly sprays gas and liquid at the same time, and swings under the drive of the rotating arm, when it swings to a position close to the center of the wafer, the swing speed is large, and when it swings to a position far from the center of the wafer, the swing speed is small. The two-fluid atomization spray cleaning device of the present invention can thoroughly clean the wafer in the cleaning box by arranging the rotating platform and the spray arm in the cleaning box, and is isolated from the outside world, and the wafer is taken out after cleaning, which can avoid the influence of external impurities in the cleaning process. Increase the cleaning time; the nozzle assembly is driven to swing by the rotating arm, and the swing speed of the nozzle assembly can be conveniently controlled, and then corresponds to the position on the wafer, keeps the wafer in a wet state, and improves the cleaning quality of the wafer. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of the swing path of the two-fluid nozzle used in an embodiment of the present invention; Figure 2 A schematic diagram of the main structure of a two-fluid atomizing spray cleaning device provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the main structure of the spray arm used in an embodiment of the present invention; Figure 4 A schematic cross-sectional structure diagram of a nozzle assembly used in an embodiment of the present invention; Figure 5 It is a schematic diagram of the three-dimensional structure of the guide component used in the embodiment of the present invention.

[0018] Description of reference numerals: 10- cleaning box; 20-rotating platform; 21-clamping seat; 30-spray arm; 31-rotating arm; 32-swinging arm; 33-nozzle assembly; 331-main body; 332-gas pipeline; 333-liquid pipeline; 334-nozzle; 335-guide component; 336-gas outlet; 337-liquid outlet pipe; 338-liquid outlet; 34-bracket; 35-lifting plate; 36-lifting cylinder; 37-rotating motor. DETAILED DESCRIPTION

[0019] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0020] In the claims, description and the above-mentioned drawings of the present invention, unless otherwise clearly defined, the use of terms such as "first", "second" or "third" etc. are for distinguishing different objects rather than for describing a specific order.

[0021] Unless otherwise expressly defined, the directional words in the claims, specification and the above-mentioned drawings of the present invention, such as the use of terms such as "upper", "lower", "top", "bottom", "front", "back", "inside", "outside", "center", "lateral", "longitudinal", "horizontal", "vertical", "left", "right", "clockwise", "counterclockwise", "high", "low", etc., indicating directions or positional relationships are based on the directions and positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific direction or be constructed and operated in a specific direction, and therefore cannot be understood as limiting the specific protection scope of the present invention.

[0022] In the claims, specification and the above drawings of the present invention, unless otherwise clearly defined, if the term "fixed connection" or "fixed connection" is used, it should be understood in a broad sense, that is, any connection method without a displacement relationship and relative rotation relationship between the two, that is to say, including non-detachable fixed connection, detachable fixed connection, integrated connection and fixed connection through other devices or elements.

[0023] In the claims, description and drawings of the present invention, if the terms "include", "have" and their variations are used, they are intended to mean "including but not limited to".

[0024] The two-fluid atomization spray cleaning method provided by the present invention is now described. The two-fluid atomization spray cleaning method comprises the following steps: S10: rotating the wafer and spraying liquid on the top of the wafer to form a liquid film on the surface of the wafer; S20: Open the air inlet pipeline, and the liquid and gas are sprayed out simultaneously to form atomized particles that are injected into the liquid film; S30: The two-fluid nozzle swings back and forth between the two edges through the center of the wafer, and the swinging speed of the two-fluid nozzle gradually increases in the direction approaching the center of the wafer until the cleaning is completed.

[0025] It should be noted that the cleaning method is applicable to silicon oxide wafers, polycrystalline silicon wafers, silicon nitride wafers, bare silicon wafers, etc., and the applicable processes include cleaning and etching process, ashing process, and chemical mechanical polishing process.

[0026] Compared with the prior art, the two-fluid atomization spray cleaning method provided in this embodiment has the following characteristics: during the cleaning process, high-speed gas and high-speed liquid interact with each other to generate atomized particles for cleaning that are sprayed on the wafer. Since the two-fluid nozzle needs to swing on the top of the wafer, on the cleaning surface of the wafer, the smaller the linear velocity is near the center of the wafer, and the greater the swing speed of the two-fluid nozzle is near the center of the wafer, the splashing of the high-speed liquid flow can be significantly improved, the wafer surface can be kept moist at all times, and the cleaning quality and efficiency of the wafer can be improved.

[0027] In some embodiments, the spraying liquid is a mixture of one or more of ultrapure water, hydrofluoric acid solution, ammonia solution, and hydrogen peroxide solution.

[0028] Specifically, the spraying liquid may be a solution of sulfuric acid, hydrochloric acid, hydrogen peroxide, ammonia water, and hydrofluoric acid; a mixture of sulfuric acid, hydrofluoric acid, and water; a mixture of ammonia water and hydrogen peroxide; or a mixture of hydrochloric acid and hydrogen peroxide.

[0029] For example, the spray liquid is a mixture of ammonia water (NH4OH): hydrogen peroxide (H2O2): water (H2O) = 1:2:50.

[0030] In some embodiments, the inlet gas line contains nitrogen, argon or carbon dioxide.

[0031] In some embodiments, the top surface of the wafer has a first cleaning area located in the center and a second cleaning area located in the outer ring of the first cleaning area. The two-fluid nozzle swings at a first speed in the first cleaning area and swings at a second speed in the second cleaning area, and the second speed is less than the first speed. The two-fluid nozzle switches the swing speed only at the junction of the first cleaning area and the second cleaning area. When in the first cleaning area, it swings at a uniform speed of the first speed, and when in the second cleaning area, it swings at a uniform speed of the second speed. The speed switching mode of the two-fluid nozzle in this way is simple and can ensure the cleaning effect of the wafer.

[0032] Specifically, the ratio of the outer diameter of the second cleaning area to the diameter of the wafer is 5:6-9:10. That is, there is a certain interval between the entire range of wafer swing and the edge of the wafer. Combined with the rotation of the wafer, the entire surface of the wafer can be cleaned, reducing costs and increasing efficiency.

[0033] For example, the size of the wafer is 12 inches, the radius of the first cleaning zone is 90 mm, the first speed is 50 mm / s, the outer edge radius of the second cleaning zone is 130 mm, and the second speed is 30 mm / s.

[0034] See also Figure 1 , the swing process of the two-fluid nozzle is divided into: Clockwise swing: 130mm→90mm process: 30mm / s; 90mm→-90mm process: 50mm / s; -90→-130mm process: 30mm / s; Counterclockwise swing: -130→-90mm process: 30mm / s; -90mm→90mm process: 50mm / s; 90mm→130mm process: 30mm / s; One counterclockwise swing and one clockwise swing form a reciprocating swing process.

[0035] Based on the same inventive concept, see Figures 2 to 5 The embodiment of the present application also provides a two-fluid atomization spray cleaning device for implementing a two-fluid atomization spray cleaning method, including a cleaning box 10, a rotating platform 20 and a spray arm 30. The rotating platform 20 is arranged in the cleaning box 10, and a clamping seat 21 for fixing the wafer is provided on the rotating platform 20; the spray arm 30 is arranged in the cleaning box 10, and the spray arm 30 includes a rotating arm 31, a swing arm 32 fixedly arranged on the top of the rotating arm 31, and a nozzle assembly 33 fixedly arranged at the free end of the swing arm 32. The rotating arm 31 is used to drive the swing arm 32 to rotate and lift.

[0036] Compared with the prior art, the two-fluid atomizing spray cleaning device provided in this embodiment fixes the wafer on the clamping seat 21, and drives the clamping seat 21 to rotate by the rotating platform 20, thereby realizing the rotation of the wafer, and the rotating arm 31 drives the swing arm 32 to rotate until the nozzle assembly 33 is above the center of the wafer, and adjusts the distance between the nozzle assembly 33 and the wafer surface by lifting and lowering, and opens the nozzle assembly 33 to spray liquid until a liquid film is formed on the surface of the wafer. Then, the nozzle assembly 33 sprays gas and liquid at the same time, and swings under the drive of the rotating arm 31. When it swings to a position close to the center of the wafer, the swing speed is large, and when it swings to a position far from the center of the wafer, the swing speed is small. The two-fluid atomizing spray cleaning device of the present invention can thoroughly clean the wafers in the cleaning box 10 by arranging the rotating platform 20 and the spray arm 30 in the cleaning box 10, and isolate them from the outside world. The wafers are taken out after cleaning, which can avoid the increase of cleaning time due to the influence of external impurities during the cleaning process; the rotating arm 31 drives the nozzle assembly 33 to swing, and the swing speed of the nozzle assembly 33 can be conveniently controlled to correspond to the position on the wafer, thereby keeping the wafer in a wet state and improving the cleaning quality of the wafer.

[0037] In some embodiments, a specific implementation of the spray arm 30 may be as follows: Figure 3 See the structure shown. Figure 3 The spray arm 30 also includes a bracket 34, a lifting plate 35, a lifting cylinder 36 and a rotating motor 37. The lifting plate 35 is slidably connected to the bracket 34 in the up-down direction; the piston rod of the lifting cylinder 36 is fixedly connected to the lifting plate 35; the rotating motor 37 is fixedly arranged on the top of the lifting plate 35, and the output shaft of the rotating motor 37 is arranged up and down and fixedly connected to the bottom end of the rotating arm 31. The lifting plate 35 can be driven to rise and fall by the lifting cylinder 36, and the lifting and falling of the lifting plate 35 drives the rotating motor 37 and the rotating arm 31 to rise and fall, so as to realize the lifting and falling of the nozzle assembly 33; after the rotating motor 37 is turned on, the output shaft rotates forward and reversely to realize the swing of the nozzle assembly 33 on the top of the wafer.

[0038] In this embodiment, the lifting plate 35 is driven to rise and fall by the lifting cylinder 36, and the lifting plate 35 and the bracket 34 are slidably matched to ensure that the lifting path of the rotating arm 31 remains vertical, so that when the nozzle assembly 33 corresponds to the center of the wafer, even if the rotating arm 31 is raised and lowered, it can be ensured that the nozzle assembly 33 passes through the center of the wafer when swinging; the swing of the nozzle assembly 33 is controlled by the rotating motor 37, which is convenient for control, and the rotation speed of the rotating motor 37 affects the swing speed of the nozzle assembly 33, which is convenient for adjustment. The rotating motor 37 can also be connected to a control system such as a PLC to realize automatic adjustment of the nozzle assembly 33.

[0039] In some embodiments, a specific implementation of the nozzle assembly 33 can be as follows: Figure 4 and Figure 5See the structure shown. Figure 4 and Figure 5 The nozzle assembly 33 includes a main body 331 and a guide component 335. The main body 331 has a gas pipeline 332, a liquid pipeline 333 and a nozzle 334. The gas pipeline 332 is evenly provided with multiple gas pipelines 332 around the axial direction of the liquid pipeline 333. The nozzle 334 is respectively connected with the multiple gas pipelines 332 and the liquid pipeline 333; the guide component 335 is arranged in the nozzle 334, and the guide component 335 is provided with a gas outlet area and a liquid outlet area alternately arranged around the axial direction of the liquid pipeline 333. The gas outlet area corresponds to the gas pipeline 332 one by one and has a gas outlet hole 336. The liquid outlet area is a liquid outlet pipe 337 connected with the liquid pipeline 333, and the liquid outlet pipe 337 is open at one end away from the liquid pipeline. The gas in each gas pipeline 332 is ejected through the gas outlet hole 336 of the corresponding gas outlet area, and the liquid on the liquid pipeline 333 is branched to each liquid outlet pipe 337 for ejection. By alternating the liquid outlet area and the gas outlet area, the liquid and gas can be fully mixed to enhance the atomization effect.

[0040] Among them, the cross-sectional shape of the main body 331 can be circular, triangular, polygonal, fan-shaped, long and narrow, etc. The guide rod component is used to guide the cleaning liquid and cleaning gas out and form atomized particles, thereby improving the mechanical decontamination capability and achieving low damage to the wafer.

[0041] It should be noted that, in the actual cleaning process, the emission direction of the nozzle 334 is perpendicular to the surface of the wafer.

[0042] Specifically, see Figure 5 The side wall of the liquid outlet pipe 337 is provided with a plurality of liquid outlet holes 338 spaced apart along its own axial direction. The axial angle between the liquid outlet holes 338 and the liquid pipeline 333 is 20° to 70°, which can have a good atomization particle formation effect.

[0043] The air outlet 336 and the liquid outlet 338 are circular or other shapes. When they are circular, the diameter is 5 to 1500 μm. When they are other shapes, the distance between the top surface and the bottom surface is 5 to 1500 μm. Alternatively, the air outlet 336 and the liquid outlet 338 are circular or in other shapes. When they are circular, the diameter is 100 to 500 μm. When they are in other shapes, the distance between the top surface and the bottom surface is 100 to 500 μm.

[0044] During operation, the flow rate of the liquid outlet 338 is 100 to 500 ml / min, and the flow rate of the gas outlet 336 is 10 to 100 L / min.

[0045] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A two-fluid atomization spray cleaning method, characterized in that: The steps include: S10: rotating the wafer and spraying liquid on the top of the wafer to form a liquid film on the surface of the wafer; S20: opening the air inlet pipeline, and the liquid and gas are sprayed out simultaneously to form atomized particles that are injected into the liquid film; S30: The two-fluid nozzle swings back and forth between the two edges through the center of the wafer, and the swinging speed of the two-fluid nozzle gradually increases in a direction approaching the center of the wafer until cleaning is completed.

2. The two-fluid atomization spray cleaning method according to claim 1, characterized in that: The spraying liquid is a mixture of one or more of ultrapure water, hydrofluoric acid solution, ammonia water and hydrogen peroxide solution.

3. The two-fluid atomization spray cleaning method according to claim 1, characterized in that: The air inlet pipeline contains nitrogen, argon or carbon dioxide.

4. The two-fluid atomization spray cleaning method according to claim 1, characterized in that: The top surface of the wafer has a first cleaning area located in the center and a second cleaning area located in the outer ring of the first cleaning area. The two-fluid nozzle swings in the first cleaning area at a first speed and swings in the second cleaning area at a second speed, and the second speed is less than the first speed.

5. The two-fluid atomization spray cleaning method according to claim 4, characterized in that: The ratio of the outer diameter of the second cleaning zone to the diameter of the wafer is 5:6-9:

10.

6. The two-fluid atomization spray cleaning method according to claim 4, characterized in that: The size of the wafer is 12 inches, the radius of the first cleaning area is 90 mm, the first speed is 50 mm / s, the outer edge radius of the second cleaning area is 130 mm, and the second speed is 30 mm / s.

7. A two-fluid atomizing spray cleaning device, characterized in that: The two-fluid atomization spray cleaning method according to any one of claims 1 to 6 comprises: Cleaning box; A rotating platform is disposed in the cleaning box, and a clamping seat for fixing the wafer is provided on the rotating platform; A spray arm is arranged in the cleaning box, and comprises a rotating arm, a swing arm fixedly arranged on the top of the rotating arm, and a nozzle assembly fixedly arranged on the free end of the swing arm. The rotating arm is used to drive the swing arm to rotate and lift.

8. The two-fluid atomizing spray cleaning device according to claim 7, characterized in that: The spray arm also includes: Bracket; A lifting plate, slidably connected to the bracket in an up-and-down direction; A lifting cylinder, the piston rod of which is fixedly connected to the lifting plate; The rotating motor is fixed on the top of the lifting plate, and the output shaft of the rotating motor is arranged up and down and fixedly connected to the bottom end of the rotating arm.

9. The two-fluid atomizing spray cleaning device according to claim 7, characterized in that: The nozzle assembly comprises: A main body, comprising a gas pipeline, a liquid pipeline and a nozzle, wherein a plurality of gas pipelines are evenly arranged around the axial direction of the liquid pipeline, and the nozzles are respectively connected with the plurality of gas pipelines and the liquid pipelines; A guide component is arranged in the nozzle, and is provided with a gas outlet area and a liquid outlet area alternately arranged axially around the liquid pipeline. The gas outlet area corresponds to the gas pipeline one by one and has a gas outlet hole. The liquid outlet area is a liquid outlet pipe connected to the liquid pipeline, and the liquid outlet pipe is open at one end away from the liquid pipeline.

10. The two-fluid atomizing spray cleaning device according to claim 9, characterized in that: The side wall of the liquid outlet pipe is provided with a plurality of liquid outlet holes spaced apart along the axial direction thereof, and the axial angle between the liquid outlet holes and the liquid pipeline is 20° to 70°.

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