Wafer cleaning device

Abstract

The utility model provides a wafer cleaning device. The wafer cleaning device comprises a box body, an ultrasonic generating device, a wafer supporting structure and a spoiler, the box body comprises a cavity with an opening; the ultrasonic generating device is mounted on the box body; the wafer supporting structure and the spoiler are both mounted in the cavity; the wafer supporting structure is used for supporting a wafer, the spoiler is arranged below the wafer supporting structure, the spoiler can move in a reciprocating mode relative to the wafer supporting structure in the first direction, and a plurality of first through holes are formed in the spoiler. The ultrasonic generating device emits ultrasonic waves, high-frequency mechanical vibration generated by the ultrasonic waves can enable a solution in the box body to vibrate and generate a plurality of microbubbles, and the microbubbles can keep vibrating under the action of the high-frequency mechanical vibration; when the spoiler reciprocates in the first direction, the spoiler can disturb the solution and the bubbles, the contact angle and impact force of the bubbles on the silicon crystal slag are increased, and therefore the cleaning effect is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of semiconductor manufacturing, especially relates to a wafer cleaning device. BACKGROUND

[0002] As shown in Figure 1 and Figure 2 In the semiconductor manufacturing process, the wafer 101 needs to be sequentially subjected to trimming processing, the trimmed wafer 101 is cleaned using ultrapure water, the wafer 101 is subjected to chemical mechanical polishing (CMP), and the wafer 101 surface is viewed using a transmission electron microscope (TEM).

[0003] As shown in Figure 2 and Figure 3 The trimming processing can remove the incomplete grains at the edge of the wafer 101; when the wafer 101 is subjected to trimming processing, a cutter is used to trim the edge of the wafer 101, and the cutter will generate steps and silicon slag 102 on the surface of the wafer 101 when trimming the wafer 101, Figure 3 The white particles indicated by the arrow in the middle are images of the silicon slag 102 at the step position of the wafer 101 under the transmission electron microscope. The effect of cleaning the trimmed wafer 101 using ultrapure water is not good, because the silicon slag 102 accumulated at the step position is not easy to be cleaned away due to the obstruction of the step. As shown in Figure 4 If there is residual silicon slag 102 on the wafer 101, the wafer 101 will grind the silicon slag 102 to other positions of the wafer 101 after chemical mechanical polishing and will scratch the surface of the wafer 101, Figure 4 The small particles on the wafer 101 are images of the silicon slag 102 under the transmission electron microscope. Utility model content

[0004] The utility model provides a kind of wafer cleaning device to solve the technical problem that silicon slag accumulated at step position is not easy to be cleaned away.

[0005] To solve the above technical problems, the utility model provides a kind of wafer cleaning device, including box, ultrasonic generating device, wafer support structure and spoiler;

[0006] The box comprises a chamber with an opening; the ultrasonic generating device is installed on the box; the spoiler is installed in the chamber; the wafer support structure is used for supporting a wafer, the spoiler is arranged below the wafer support structure, and the spoiler is reciprocally movable relative to the wafer support structure along a first direction, and a plurality of first through holes are arranged on the spoiler.

[0007] Preferably, the wafer cleaning device further comprises an air-permeable plate arranged in the box, the air-permeable plate is installed below the spoiler, a plurality of second through holes are arranged on the air-permeable plate, and gaps are formed between the plurality of second through holes and the inner bottom surface of the box.

[0008] Preferably, a plurality of second through holes are arranged below each first through hole.

[0009] Preferably, the spoiler is installed on the air-permeable plate through an elastic connecting member.

[0010] Preferably, the opening shape of the first through hole is rectangular, two long edges of at least one first through hole are respectively provided with two parallel sliding rails, a spoiler is arranged on the first through hole by sliding through the two sliding rails, the spoiler is reciprocally movable on the sliding rails relative to the wafer support structure along a second direction, the first direction is perpendicular to the second direction, and a third through hole is arranged on the spoiler.

[0011] Preferably, the wafer cleaning device further comprises a first driving unit and a second driving unit, the first driving unit is connected with the spoiler, and the second driving unit is connected with the spoiler; the first driving unit drives the spoiler to reciprocally move along the first direction, and the second driving unit drives the spoiler to reciprocally move along the second direction.

[0012] Preferably, the wafer cleaning device further comprises an adsorption electrode, and the adsorption electrode is installed in the chamber of the box.

[0013] Preferably, the wafer support structure comprises two or more support shafts, and the two or more support shafts are distributed on the same circumference.

[0014] Preferably, the wafer cleaning device further comprises a third driving unit, the third driving unit is connected with at least one support shaft, and the third driving unit is used for driving the support shaft to rotate along the axis direction of the support shaft.

[0015] Preferably, the ultrasonic generating device comprises an ultrasonic generator and a transducer, the ultrasonic generator is connected with the transducer, and the transducer is connected with the box.

[0016] The utility model provides a kind of wafer cleaning device, including box, ultrasonic generating device, wafer support structure and spoiler.When wafer needs to be cleaned, the solution for cleaning wafer is poured into box, and wafer is placed on wafer support structure, solution needs to immerse the position of wafer needing to be cleaned, for example, solution immerses wafer edge 2.4 millimeter height;Ultrasonic generating device emits ultrasonic wave, and high frequency mechanical vibration generated by ultrasonic wave can make solution in box vibrate and generate several microbubbles, and microbubble can keep vibrating under the action of high frequency mechanical vibration;When spoiler reciprocates along first direction, it can disturb flow to solution and bubble, increase the contact angle and impact force of bubble to silicon slag, so as to improve cleaning effect.The unexpected effect of the device is that wafer can be effectively cleaned, even if silicon slag is gathered in step position, silicon slag is also completely cleaned under the multiple actions of solution vibration, bubble impact and solution soaking.The wafer cleaning device provided in the scheme can effectively clean silicon slag gathered in step position after edge trimming, to prevent silicon slag from scratching wafer in subsequent chemical mechanical polishing process. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 It is the process flow diagram of wafer in prior art from edge trimming to use transmission electron microscope to view wafer surface.

[0018] Figure 2 It is the structure diagram of wafer after being edge trimmed in prior art.

[0019] Figure 3 It is Figure 2 The image of wafer step position and silicon slag under transmission electron microscope in

[0020] Figure 4 It is the image of four wafers after chemical mechanical polishing under transmission electron microscope in prior art.

[0021] Figure 5 It is the structure diagram of wafer cleaning device and wafer provided by an embodiment of the utility model.

[0022] Figure 6 It is the structure diagram of spoiler provided by an embodiment of the utility model.

[0023] Figure 7 It is the structure diagram of air-permeable plate provided by an embodiment of the utility model.

[0024] Figure 8 It is the structure diagram of adsorption electrode and wafer provided by an embodiment of the utility model.

[0025] [The following is explained as follows]:

[0026] Wafer-101, silicon slag-102;

[0027] Box-1, ultrasonic generating device-2, wafer support structure-3, spoiler-4, air permeable plate-5, adsorption electrode-6;

[0028] Support shaft-31; first through hole-41, slide rail-42, spoiler-43; second through hole-51. DETAILED DESCRIPTION

[0029] In order to make the purpose, advantages and characteristics of the utility model more clear, the following will make further detailed description to the wafer cleaning device provided by the utility model in combination with the drawings. It should be noted that the drawings are all very simplified and all use non-precise proportion, and are only used to facilitate and clearly assist the purpose of explaining the embodiments of the utility model.

[0030] In the description of the utility model, the terms "first", "second" and the like qualifiers are added for the convenience of description and reference, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features with "first", "second" and the like qualifiers can explicitly or implicitly include one or more of the features.

[0031] As shown in Figure 5 and Figure 6 , the embodiment provides a wafer cleaning device, which comprises a box 1, an ultrasonic generating device 2, a wafer support structure 3 and a spoiler 4; the box 1 comprises a chamber with an opening; the ultrasonic generating device 2 is installed on the box 1; the spoiler 4 is installed in the chamber; the wafer support structure 3 is used for supporting a wafer 101, the spoiler 4 is arranged below the wafer support structure 3, and the spoiler 4 is reciprocally movable along a first direction relative to the wafer support structure 3, and a plurality of first through holes 41 are arranged on the spoiler 4. Wherein, the first direction is preferably a direction parallel to the bottom surface of the box 1, for example, the first direction is parallel to the long edge direction of the bottom surface of the box 1, so as to improve the spoiler effect of the spoiler 4; the axis direction of the first through hole 41 and the opening of the box 1 are preferably perpendicular to each other, so that the bubbles passing through the first through hole 41 can contact the wafer 101.

[0032] As shown in Figure 5 , Figure 6 and Figure 8As shown, the wafer cleaning device provided by the embodiment includes a box body 1, an ultrasonic generating device 2, a wafer support structure 3 and a spoiler 4. When the wafer 101 needs to be cleaned, the solution used for cleaning the wafer 101 is poured into the box body 1, and the wafer 101 is placed on the wafer support structure 3. The solution needs to immerse the position of the wafer 101 that needs to be cleaned, for example, the solution immerses the edge of the wafer 101 by 2.4 millimeters in height. The ultrasonic generating device 2 emits ultrasonic waves, and the high-frequency mechanical vibration generated by the ultrasonic waves can make the solution in the box body 1 vibrate and generate a plurality of micro-bubbles. The micro-bubbles can keep vibrating under the action of the high-frequency mechanical vibration. When the spoiler 4 reciprocates along the first direction, it can disturb the solution and the bubbles, increase the contact angle and impact force of the bubbles on the silicon slag 102, and thus improve the cleaning effect. The device has the unexpected effect that the wafer 101 can be effectively cleaned. Even if the silicon slag 102 is accumulated at the step position, the silicon slag 102 will also be completely cleaned under the multiple actions of solution vibration, bubble impact and solution immersion. The wafer cleaning device provided by the scheme can effectively clean the silicon slag 102 accumulated at the step position after edge trimming, and prevent the silicon slag 102 from scratching the wafer 101 in the subsequent chemical mechanical polishing process.

[0033] Preferably, as shown in Figures 5-7 As shown, the wafer cleaning device further includes an air-permeable plate 5 arranged in the box body 1, the air-permeable plate 5 is installed below the spoiler 4, a plurality of second through holes 51 are arranged on the air-permeable plate 5, and there is a gap between the plurality of second through holes 51 and the inner bottom surface of the box body 1. The second through holes 51 have the functions of gathering and guiding the bubbles in the solution. The bubbles dispersed below the air-permeable plate 5 move towards the spoiler 4 after passing through the second through holes 51, and then impact the wafer 101 after passing through the first through holes 41 on the spoiler 4. The more bubbles disturbed by the spoiler 4, the better the cleaning effect of the wafer 101.

[0034] Preferably, as shown in Figures 5-7 As shown, a plurality of second through holes 51 are arranged below each first through hole 41. This arrangement can make more bubbles pass through each first through hole 41, and prevent the first through hole 41 from having no bubbles passing through or having too few bubbles passing through. In specific use, at least one row of second through holes 51 can be arranged below each first through hole 41, and each row of second through holes 51 includes a plurality of second through holes 51, so as to increase the number of bubbles passing through the first through hole 41 and thus improve the cleaning effect.

[0035] Preferably, as shown in Figure 5As shown, the spoiler 4 is mounted on the air-permeable plate 5 through elastic connecting members. The elastic connecting members can be springs or plastic columns with elasticity. The spoiler 4 can reciprocate relative to the air-permeable plate 5 through the elastic connecting members, so as to disturb the solution and the bubbles. In other embodiments, the spoiler 4 can be mounted in the box 1 through sliding rails or swingable connecting arms, so as to make the spoiler 4 reciprocate relative to the wafer support structure 3 along the first direction.

[0036] Preferably, as shown in Figure 5 and Figure 6 shown, the first through hole 41 has a rectangular opening shape, and two long edges of the first through hole 41 are respectively provided with two parallel sliding rails 42. A spoiler 43 is arranged on the first through hole 41 through the two sliding rails 42. The spoiler 43 can reciprocate on the sliding rails 42 relative to the wafer support structure 3 along a second direction. The first direction is perpendicular to the second direction. The spoiler 43 is provided with a third through hole. The spoiler 4 can exert a force along the first direction on the solution and the bubbles during reciprocation, and the spoiler 43 can exert a force along the second direction on the solution and the bubbles during reciprocation. Since the first direction is perpendicular to the second direction, the solution and the bubbles can be disturbed better, and the cleaning effect on the wafer 101 can be improved. The axis directions of the first through hole 41, the second through hole 51 and the third through hole can be perpendicular to the opening and the bottom surface of the box 1. If the bottom surface of the box 1 is rectangular, the first direction can be parallel to the long edge direction of the bottom surface of the box 1, and the second direction can be parallel to the short edge direction of the bottom surface of the box 1. Preferably, two sliding rails 42 and one spoiler 43 are arranged on each first through hole 41, so as to improve the disturbing effect. The sliding rails 42 and the spoiler 43 can be arranged on the upper surface or the lower surface of the first through hole 41. Preferably, the sliding rails 42 and the spoiler 43 are arranged on the upper surface of the first through hole 41, so as to prevent the spoiler 43 from falling off the sliding rails 42.

[0037] Preferably, as shown in Figure 5 shown, the wafer cleaning device further comprises a first driving unit and a second driving unit. The first driving unit is connected with the spoiler 4, and the second driving unit is connected with the spoiler 43. The first driving unit drives the spoiler 4 to reciprocate along the first direction, and the second driving unit drives the spoiler 43 to reciprocate along the second direction. The first driving unit and the second driving unit can be motors or air cylinders. Through the driving of the first driving unit and the second driving unit, the spoiler 4 and the spoiler 43 can be moved simultaneously, so as to improve the disturbing effect.

[0038] Preferably, as shown in Figure 5 and Figure 8As shown, the wafer cleaning device further comprises an adsorption electrode 6, which is installed in the cavity of the box 1. The solution used to clean the silicon slag 102 is usually an alkaline solution. After the silicon slag 102 is soaked in the alkaline solution, the silicon atoms Si react with the hydroxyl ions OH - to generate negative ions containing silicon atoms Si, which can be adsorbed by the positively charged adsorption electrode 6, thereby further reducing the silicon slag 102 on the wafer 101. The adsorption electrode 6 can be driven by a driving unit to rotate around its own axis direction, so as to improve the adsorption of the negative ions by the adsorption electrode 6.

[0039] Preferably, as shown in Figure 5 The wafer support structure 3 comprises two or more support shafts 31, which are distributed on the same circumference. The two or more support shafts 31 can effectively support the wafer 101 and prevent the wafer 101 from falling to the bottom of the box 1. The middle position of the support shaft 31 can be provided with a groove for accommodating the edge of the wafer 101, which can further prevent the wafer 101 from falling to the bottom of the box 1.

[0040] Preferably, as shown in Figure 5 The wafer cleaning device further comprises a third driving unit, which is connected with at least one of the support shafts 31, and is used to drive the support shaft 31 to rotate along the axis direction of the support shaft 31. The third driving unit can drive the support shaft 31 to rotate along the axis direction of the support shaft 31, i.e. along its own axis direction. When the support shaft 31 rotates, it drives the wafer 101 to rotate through static friction, so that different positions of the edge of the wafer 101 can be effectively cleaned.

[0041] Preferably, as shown in Figure 5 The ultrasonic generating device 2 comprises an ultrasonic generator and a transducer, the ultrasonic generator is connected with the transducer, and the transducer is connected with the box 1. The ultrasonic generator and the transducer usually need to be used together. The ultrasonic generator can emit a high-frequency oscillation signal, and the transducer can convert the high-frequency oscillation signal into ultrasonic waves. The high-frequency mechanical vibration generated by the ultrasonic waves can make the solution in the box 1 vibrate and produce a number of micro-bubbles.

[0042] Preferably, as shown in Figure 5As shown, the wafer cleaning device further comprises a clamping plate for limiting the wafer 101; the box 1 comprises a left side plate, a rear side plate, a right side plate and a front side plate connected in sequence; one side of the clamping plate is vertically connected with the inner wall of the left side plate or the right side plate, and the other side extends in the direction of the supporting shaft 31; the front side plate, the clamping plate and the rear side plate are parallel; the inner walls of the clamping plate and the rear side plate form a clamping groove for limiting the wafer 101. A part of the side edge of the wafer 101 can be inserted into the clamping groove, and the wafer 101 can be vertically placed in the box 1 under the double action of the clamping groove and the wafer supporting structure 3 without falling to the bottom of the box 1.

[0043] In summary, the wafer cleaning device provided by the utility model has the unexpected effect that the wafer 101 can be effectively cleaned, even if the silicon slag 102 is gathered at the step position, the silicon slag 102 can also be completely cleaned under the multiple actions of solution vibration, bubble impact and solution soaking. The wafer cleaning device provided by the scheme can effectively clean the silicon slag 102 gathered at the step position after edge trimming, and prevent the silicon slag 102 from scratching the wafer 101 in the subsequent chemical mechanical grinding process.

[0044] The above description is only a description of the preferred embodiments of the utility model, and does not limit the scope of the utility model, and any change or modification made by the ordinary skilled in the art according to the above disclosure is within the protection scope of the utility model.

Claims

1. A wafer cleaning apparatus, characterized in that, Includes housing, ultrasonic generator, wafer support structure, and baffle plate; The housing includes a chamber with an opening; the ultrasonic generator is mounted on the housing; the baffle is mounted inside the chamber; the wafer support structure is used to support the wafer; the baffle is disposed below the wafer support structure and is reciprocating relative to the wafer support structure in a first direction; the baffle is provided with a plurality of first through holes.

2. The wafer cleaning apparatus as described in claim 1, characterized in that, The wafer cleaning device also includes a vent plate disposed inside the housing. The vent plate is installed below the baffle plate and has a plurality of second through holes. There is a gap between the plurality of second through holes and the inner bottom surface of the housing.

3. The wafer cleaning apparatus as described in claim 2, characterized in that, Multiple second through holes are provided below each of the first through holes.

4. The wafer cleaning apparatus as described in claim 2, characterized in that, The spoiler is mounted on the breathable plate via an elastic connector.

5. The wafer cleaning apparatus as described in claim 1, characterized in that, The first through hole has a rectangular opening shape. At least one of the two long sides of the first through hole is provided with two parallel slide rails. A flow disruptor is slidably disposed on the first through hole via the two slide rails. The flow disruptor can reciprocate relative to the wafer support structure along a second direction on the slide rails. The first direction is perpendicular to the second direction. A third through hole is provided on the flow disruptor.

6. The wafer cleaning apparatus as described in claim 5, characterized in that, The wafer cleaning apparatus further includes a first driving unit and a second driving unit. The first driving unit is connected to the baffle plate, and the second driving unit is connected to the baffle element. The first driving unit drives the baffle plate to reciprocate along a first direction, and the second driving unit drives the baffle element to reciprocate along a second direction.

7. The wafer cleaning apparatus as described in claim 1, characterized in that, The wafer cleaning apparatus also includes an adsorption electrode, which is installed in the cavity of the housing.

8. The wafer cleaning apparatus as described in claim 1, characterized in that, The wafer support structure includes two or more support shafts, which are spaced apart and distributed on the same circumference.

9. A wafer cleaning apparatus as described in claim 8, characterized in that, The wafer cleaning apparatus further includes a third driving unit, which is connected to at least one of the support shafts and is used to drive the support shafts to rotate along the axial direction of the support shafts.

10. A wafer cleaning apparatus as described in claim 1, characterized in that, The ultrasonic generating device includes an ultrasonic generator and a transducer, wherein the ultrasonic generator is connected to the transducer, and the transducer is connected to the housing.

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