SUMMERY OF THE UTILITY MODEL
The utility model provides a silicon chip belt cleaning device, especially, be applicable to the washing one by one of jumbo size silicon chip, solved current cleaning technology and leaded to silicon chip surface cleaning unqualified in batches, the technical problem that the cleaning efficiency is low.
In order to solve the technical problem, the utility model discloses a technical scheme is:
a silicon wafer cleaning device comprises a first cleaning part and a second cleaning part, wherein,
the first cleaning part and the second cleaning part are both provided with:
the turntable is contacted with the edge of the silicon wafer and is used for controlling the rotation of the silicon wafer and suspending the silicon wafer;
the spraying groups are arranged on the surfaces of two sides of the silicon wafer and are used for spraying the surfaces of two sides of the silicon wafer;
and a brush is also arranged in the first cleaning part for brushing the silicon wafer.
Further, the turntable includes:
the fixing table is provided with a plurality of strip holes along the plane;
the rotary head is vertically arranged, an annular groove is formed along the outer wall surface of the rotary head, and the groove is directly matched with the edge of the silicon wafer;
the support column is fixed on the fixed table and vertically arranged through the strip hole, a rotating shaft is arranged in the support column, and the rotating head is arranged at the top of the rotating shaft;
and the output end of the motor is connected with the rotating shaft so as to drive the rotating head to rotate along the vertical axial direction.
Furthermore, the extension ends of all the elongated holes are intersected at the circle center of the fixed table and are divergently arranged along the periphery of the fixed table.
Furthermore, a track is arranged in the long hole along the length direction of the long hole, and the support column is connected with the track in a sliding manner;
the support column can drive the rotating head to slide along the track in a reciprocating mode.
Furthermore, the fixed table and the silicon wafer are coaxially arranged.
Furthermore, the spraying group comprises a plurality of symmetrically arranged spraying pipes, and the spray heads of all the spraying pipes are obliquely arranged towards the center of the silicon wafer.
Furthermore, each side surface of the silicon wafer is provided with the spray pipes which are symmetrically arranged relative to the diameter of the silicon wafer;
all the spray pipes on the surfaces of the two sides of the silicon wafer are vertically arranged at the same position.
Furthermore, in the second cleaning part, each side surface of the silicon wafer is also provided with a gas pipe for gas circulation;
the gas pipes on each side surface of the silicon wafer are symmetrically arranged relative to the diameter of the silicon wafer;
all the air pipes on the surfaces of the two sides of the silicon wafer are vertically arranged at the same position.
Further, the brushes are respectively arranged on the surfaces of the two sides of the silicon wafer, are arranged in a semicircle at one side of the silicon wafer and can reciprocate along the diameter direction of the semicircle of the silicon wafer.
Further, the brush is configured as a rotatable circular structure.
The silicon wafer cleaning device is particularly suitable for cleaning large-size silicon wafers one by one, the silicon wafers are cleaned in a single-wafer mode, and the silicon wafers are continuously blown and dried after being cleaned; for original traditional slot type cleaning process, the utility model discloses can reduce granule and the metallic impurity on polishing silicon chip surface, make silicon chip surface reduce anti-by the pollution.
Detailed Description
The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.
The embodiment provides a silicon wafer cleaning device 100, as shown in fig. 1-2, which includes a first cleaning part 1 and a second cleaning part 2, wherein the first cleaning part 1 and the second cleaning part 2 are both provided with a turntable 10 and a spraying group 20, and the turntable 10 is in contact with the edge of a silicon wafer 40 and is used for controlling the silicon wafer 40 to rotate and horizontally suspending the silicon wafer 40 and keeping the two side surfaces of the silicon wafer 40 exposed; the spraying groups 20 are arranged on the two side surfaces of the silicon wafer 40 and are used for spraying the two side surfaces of the silicon wafer 40; and the first cleaning part 1 is also provided with a brush 30 for brushing the silicon wafers so as to independently brush each silicon wafer and clean impurities on the surfaces of the silicon wafers.
Specifically, the turntable 10 includes a fixed table 11, a rotary head 12, a support column 13, and a motor. The fixed table 11 is a circular structure, and in order to ensure the placing consistency and stability of the silicon wafer 40, the fixed table 11 and the silicon wafer 40 are required to be configured coaxially, the structure of the fixed table is shown in fig. 3, and the fixed table 11 is provided with a plurality of strip holes 14 along the plane thereof; the rotary heads 12 are vertically arranged, at least three rotary heads 12 are arranged on each fixed table 11, the structure of the rotary heads is shown in figure 4, annular grooves are arranged along the outer wall surfaces of the rotary heads 12, and the grooves are directly matched with the edges of the silicon wafers 40; the supporting column 13 is fixed on the fixed table 11 and vertically arranged through the strip hole 14, a rotating shaft is arranged in the supporting column, and the rotating head 12 is arranged at the top of the rotating shaft; the output end of the motor is connected with the rotating shaft, the motor can drive the rotating shaft to drive the rotating heads 12 to rotate along the vertical axial direction, all the rotating heads 12 rotate synchronously, and then the silicon wafers can be driven to rotate horizontally.
As shown in fig. 3, a rail 15 is provided in each elongated hole 14; the extension ends of all the strip holes 14 are intersected at the center of the fixed platform 11 and are divergently arranged along the periphery of the fixed platform 11, and the lower end of the support column 13 is connected with the track 15 in a sliding manner. So as to form a long hole 14 which is uniformly distributed and arranged along the center of the fixed table 11; a rail 15 is arranged in the long hole 14 along the length direction of the long hole, and the support column 13 is driven to drive the rotating head 12 to slide towards one end close to the circle center of the fixed table 11 along the rail 15, so that the placing space is synchronously contracted to fix the silicon wafer 40; or the driving support column 13 drives the rotating head 12 to slide along the rail 15 towards one end far away from the circle center of the fixed table 11, so as to synchronously enlarge the placing space and loosen the silicon wafer 40.
During cleaning, the silicon wafer 40 is adsorbed and fixed by the manipulator, the polished silicon wafer 40 is moved to a position right above the fixed table 11 in the cleaning part 1, the horizontal position of the silicon wafer 40 is adjusted, the front side of the silicon wafer 40 is controlled to face upwards, the back side of the silicon wafer 40 is controlled to face downwards, meanwhile, all the support columns 13 are controlled to drive the rotating heads 12 to synchronously slide towards one end close to the circle center of the fixed table 11 along the rails 15, the placing space is contracted together, so that grooves of all the rotating heads 12 are in contact with the outer edge of the silicon wafer 40, and the silicon wafer 40 is fixed to be suspended. And then the rotating shafts on all the supporting columns 13 are controlled to synchronously rotate in the same direction, so that all the rotating heads 12 synchronously and simultaneously give a driving force for rotating the silicon wafer 40, and the silicon wafer 40 is driven to horizontally rotate. The rotating speed of the rotating shaft is controlled, and the rotating speed of the silicon chip 40 can be indirectly adjusted.
Further, the spraying group 20 includes a plurality of symmetrically arranged nozzles, and the nozzles of all the nozzles are inclined toward the center of the silicon wafer 40, and the inclination angle may be determined based on actual conditions, but the angle is not greater than 90 °. In the process of rotating the silicon wafer 40, the liquid medicine or water can be driven to disperse on the surface thereof, and the liquid medicine or water can disperse towards the central position of the silicon wafer 40 gradually under the driving of rotation. In order to ensure the uniformity of the cleaning of both sides of the silicon wafer 40, each side surface of the silicon wafer 40 is provided with a nozzle symmetrically arranged relative to the diameter of the silicon wafer 40; and all the nozzles are vertically arranged at the same position on both side surfaces of the silicon wafer 40. The spray group 20 in each cleaning part comprises a spray pipe group arranged up and down, and spray pipes symmetrically arranged at two ends of the diameter on the upper surface of the silicon wafer 40; and symmetrically arranged spray pipes are also arranged at two ends of the diameter on the lower surface of the silicon wafer 40; and all the spray pipes arranged up and down are arranged opposite to each other.
All the spray pipes can move up and down along the vertically arranged telescopic rods, and all the spray pipes are arranged far away from the rotating head 12 before the silicon wafer 40 is placed; after the silicon wafer 40 is stably fixed, all the nozzles at both sides of the silicon wafer 40 gradually approach the surfaces of both sides of the silicon wafer 40.
Furthermore, in the cleaning part 1, the liquid medicine is a mixed liquid of ammonia water, hydrogen peroxide and water, the liquid medicine is prepared in advance, and the liquid medicine is led out from the preparation tank and directly sprayed on the surface of the silicon wafer 40, so that only four spray pipes 21 are needed to spray the liquid medicine in the cleaning part 1. In the first cleaning part 1, pure water is required to be used for cleaning after the liquid medicine is cleaned, so that a layer of water film is formed on the surface of the silicon wafer 40 and is used for protecting the two sides of the silicon wafer 40 from being polluted by air, and then the four spray pipes two 22 are required to be arranged in the first cleaning part 1 for spraying the pure water. The first spray pipe 21 and the second spray pipe 22 are distributed as shown in the figure 1-2, two spray pipes 21 and two spray pipes 22 are respectively arranged on two sides of the silicon wafer 40, and on each side surface of the silicon wafer 40, the two spray pipes 21 and the two spray pipes 22 are symmetrically arranged at two ends of the diameter of the silicon wafer 40; the vertically arranged spray pipes I21 and II 22 are vertically arranged at the same position.
Further, in the cleaning part 1, brushes 30 for helping the liquid medicine to be uniformly distributed and brushing off impurities on the surface of the silicon wafer 40 are further arranged, the number of the brushes 30 is 2, the brushes 30 are respectively arranged on the surfaces of two sides of the silicon wafer 40, are symmetrically arranged up and down and are arranged in a semicircle at one side of the silicon wafer 40 so as to ensure the cleaning balance degree of the silicon wafer 40, and the brushes 30 are controlled by a connecting rod which is telescopically arranged and can reciprocate along the diameter direction of the semicircle of the silicon wafer 40; meanwhile, the brush 30 may also be self-rotating, which is configured in a rotatable circular structure. The position of the brush 30 is spaced from the nozzle to avoid interference of the brush 30 with the nozzle during brushing. When the first spray pipe 21 and the second spray pipe 22 are simultaneously close to the silicon wafer surface, the brush 30 is also close to the double-sided surface of the silicon wafer 40 until moving to its standard position.
The brush 30 only works when the first spray pipe 21 sprays the liquid medicine, and the second spray pipe 22 does not work when the first spray pipe 21 sprays the liquid medicine; when the liquid medicine is cleaned by pure water, at the moment, the second spray pipe 22 starts to work, the brush 30 stops working and is far away from the surface of the silicon wafer 40 along the vertical height, and after the second spray pipe 22 sprays the pure water for a certain time, the rotation of the rotary head 12 is stopped, so that the silicon wafer 40 stops rotating; and when the pure water is sprayed, the rotation speed of the silicon wafer 40 is faster than that of the liquid medicine when the pure water is sprayed, so that a layer of water film is formed on the surfaces of both sides of the silicon wafer 40 in a short time.
Specifically, in the second cleaning part 2, the silicon wafer 40 is transferred from the first cleaning part 1 to the turntable 10 by the robot, and the support column 13 is controlled to drive the rotary head 12 to reinforce the edge of the silicon wafer 40 and suspend the same. The liquid medicine in the second cleaning part 2 is acid pickling liquid medicine, the components of the liquid medicine are hydrofluoric acid liquid medicine and ozone water liquid medicine, and the hydrofluoric acid liquid medicine and the ozone water liquid medicine are independently sprayed and synchronously sprayed, so that the second cleaning part 2 is provided with four spray pipes three 23 for spraying the prepared hydrofluoric acid liquid medicine with a certain concentration and four spray pipes four 24 for spraying the prepared ozone water liquid medicine with a certain concentration. The distribution of the spray pipes three 23 and four spray pipes four 24 is the same as the distribution positions of the spray pipes one 21 and two spray pipes 22 in the cleaning part one 1, and the detailed description is omitted.
The acid cleaning of the silicon wafer 40 is performed to remove the residual mixture of ammonia water, hydrogen peroxide and water on both sides of the silicon wafer 40 and simultaneously oxidize both side surfaces of the silicon wafer 40 to form an oxide film to protect the surface of the silicon wafer 40. In the process, after the liquid medicine is cleaned, the surfaces of the two sides of the silicon wafer 40 need to be dried, and the silicon wafer 40 cannot be directly dried due to the suspension of the silicon wafer 40, so that the surfaces of the two sides of the silicon wafer 40 are provided with the air pipes 25 for introducing nitrogen, namely the four air pipes 25 are arranged and are respectively arranged in parallel with the three spray pipes 23 and the four spray pipes 24. When the silicon wafer 40 is cleaned by the liquid medicine, the third spray pipe 23 and the fourth spray pipe 24 on the two sides work, and the air pipe 25 does not work; after the liquid medicine is cleaned, the third spray pipe 23 and the fourth spray pipe 24 stop working, and the air pipe 25 works. Stopping the rotation of the silicon wafer 40 after the nitrogen is introduced for a certain time; in the whole cleaning process, the silicon wafer 40 is always rotated, but the rotating speed of the silicon wafer 40 is higher than that of the silicon wafer 40 during cleaning with the liquid medicine when the nitrogen is sprayed, so that the liquid medicine on the surface of the silicon wafer 40 is quickly dried under high-speed rotation, and meanwhile, the nitrogen can quickly dry the liquid medicine on the surface of the silicon wafer 40.
A silicon wafer cleaning process using the cleaning apparatus 100 as described in any one of the above, comprising the steps of:
during cleaning, the control silicon wafer 40 is horizontally placed on the turntable 10 in the first cleaning part 1 and the turntable in the second cleaning part 2 in sequence, and the silicon wafer 40 is controlled to rotate all the time during cleaning.
S1, spraying liquid on the two sides of a silicon wafer 40 in a cleaning part I1, brushing the two sides of the silicon wafer with a brush 30, and after the liquid is cleaned, cleaning the two sides of the silicon wafer 40 with pure water to form a layer of water film on the surfaces of the two sides of the silicon wafer.
Specifically, the silicon wafer 40 is sucked and fixed by the robot, the robot moves the polished silicon wafer 40 to a position right above the fixing table 11 in the cleaning unit 1, and the horizontal position of the silicon wafer 40 is adjusted to control the front surface of the silicon wafer 40 to face upward and the back surface of the silicon wafer 40 to face downward.
And controlling all the supporting columns 13 to drive the rotating heads 12 to synchronously slide towards one end close to the circle center of the fixed table 11 along the rails 15, and simultaneously contracting the placing space so as to enable the grooves of all the rotating heads 12 to be in contact with the outer edge of the silicon wafer 40 to fix the silicon wafer 40 for suspension.
When the first nozzle 21 and the second nozzle 22 are controlled to be synchronously close to the surface of the silicon wafer, the brush 30 also approaches to the surfaces of the two sides of the silicon wafer 40 until the silicon wafer is moved to the standard position.
After the silicon wafer 40 is fixed, the rotating shafts on all the supporting columns 13 are controlled to synchronously rotate in the same direction, so that all the rotating heads 12 synchronously and simultaneously give a driving force for rotating the silicon wafer 40 to drive the silicon wafer 40 to horizontally rotate. And simultaneously controlling the four first spray pipes 21 to spray mixed liquid of ammonia water, hydrogen peroxide and water to the surfaces of the two sides of the silicon wafer 40, wherein the volume ratio of the mixed liquid of the ammonia water, the hydrogen peroxide and the water is 1:2:100. and simultaneously controlling the brush 30 to start working, wherein the brush 30 reciprocates on the surface of the silicon wafer 40 along the diameter direction of the silicon wafer 40 while rotating. The chemical solution removes the residual polishing solution on the surfaces of both sides of the silicon wafer 40, and simultaneously the chemical solution is uniformly distributed on the entire surface of the silicon wafer 40 by the brush 30, and particle impurities on the surface of the silicon wafer 40 can be brushed away.
And when the pure water is cleaned on the surfaces of the two sides of the silicon wafer 40 after the liquid medicine is cleaned, the second spray pipe 22 starts to work, the brush 30 stops working and is far away from the surface of the silicon wafer 40 along the vertical height, and the rotation of the rotary head 12 is stopped after the second spray pipe 22 sprays the pure water for 10-15s, so that the silicon wafer 40 stops rotating. Spraying pure water, wherein the rotation speed of the silicon wafer 40 is 500-2000rpm, and the rotation speed of the silicon wafer 40 is higher than that of the chemical liquid when spraying the chemical liquid, preferably, the rotation speed of the silicon wafer 40 during the pure water cleaning is 150-250rpm, which is higher than that of the silicon wafer 40 during the chemical liquid cleaning by 40-60rpm; the purpose is to form a water film on both surfaces of the silicon wafer 40 in a short time.
And S2, controlling the silicon wafer 40 to move to the second cleaning part 2, cleaning the two sides of the silicon wafer with the acidic liquid medicine, and then performing air injection drying on the two sides of the silicon wafer 40.
Specifically, the manipulator takes the silicon wafer 40 from the first cleaning part 1, transfers the silicon wafer 40 to the turntable 10 on the second cleaning part 2, and drives the rotary head 12 by controlling the support column 13 to reinforce the edge of the silicon wafer 40 and suspend the silicon wafer.
And controlling the third spray pipe 23, the fourth spray pipe 24 and the air pipe 25 to synchronously approach the surface of the silicon chip until the silicon chip is moved to the standard position.
After the silicon chip 40 is fixed, the rotating shafts on all the supporting columns 13 are controlled to synchronously rotate in the same direction, so that all the rotating heads 12 synchronously and simultaneously give a driving force for rotating the silicon chip 40, and the silicon chip 40 is driven to horizontally rotate. And simultaneously controlling the four spray pipes III 23 and the four spray pipes IV 24 to spray hydrofluoric acid liquid medicine and ozone water liquid medicine on the surfaces of the two sides of the silicon wafer 40, wherein the concentration of the hydrofluoric acid liquid medicine is 0.5-2%, and the concentration of the ozone water liquid medicine is 15-25mg/L.
The acid cleaning of the silicon wafer 40 is performed to remove the residual mixture of ammonia water, hydrogen peroxide and water on both sides of the silicon wafer 40 and simultaneously oxidize both side surfaces of the silicon wafer 40 to form an oxide film to protect the surface of the silicon wafer 40.
After the liquid medicine is cleaned, the surfaces of the two sides of the silicon wafer 40 need to be dried, nitrogen is introduced into the air pipe 25, the flow rate of the nitrogen is 0.5-2L/min, and when the nitrogen is introduced for 10-15s, the rotation of the silicon wafer 40 and the nitrogen are stopped. In the whole cleaning process, the silicon wafer 40 is always rotated, but the rotating speed of the silicon wafer 40 is 150-250rpm when the nitrogen is sprayed, which is greater than the rotating speed of the silicon wafer 40-60rpm when the silicon wafer is cleaned by the liquid medicine, so that the liquid medicine on the surface of the silicon wafer 40 is quickly dried under high-speed rotation, and meanwhile, the nitrogen can quickly dry the liquid medicine on the surface of the silicon wafer 40.
After two continuous times of cleaning, the silicon wafer is clamped by the manipulator and transferred to the storage box for sealed storage.
The cleanliness of the silicon wafer 40 with the size of 12 inches after being cleaned is detected by adopting the process, the particle level @37nm is less than or equal to 30ea through a particle detector, and the surface metal level is less than or equal to 1E9atom/cm through metal detection equipment 2 And completely meets the standard requirements of the silicon chip 40.
The silicon wafer cleaning device and the cleaning process are particularly suitable for cleaning large-size silicon wafers one by one, the silicon wafers are cleaned in a single-wafer mode, and the silicon wafers are continuously blown and dried after being cleaned; for original traditional slot type cleaning process, the utility model discloses can reduce granule and the metallic impurity on polishing silicon chip surface, make silicon chip surface reduce anti-by the pollution.
The above detailed description of the embodiments of the present invention is only for the purpose of illustrating the preferred embodiments of the present invention, and should not be taken as limiting the scope of the present invention. All the equivalent changes and improvements made according to the application scope of the present invention should still fall within the patent coverage of the present invention.