Cleaning equipment and cleaning method based on MEMS chip

Abstract

The invention discloses a cleaning device and method based on an MEMS chip, the device comprises a containing groove, the containing groove contains a cleaning solution used for cleaning the chip, the cleaning solution can be water, the side face of the containing groove is provided with a first liquid inlet and a second liquid inlet, and the first liquid inlet is communicated with the second liquid inlet. The first liquid inlet and the second liquid inlet are higher than the liquid level of the cleaning liquid; liquid discharged from the first liquid inlet is a first solution, liquid discharged from the second liquid inlet is a second solution, and the liquid level tension of the first cleaning liquid and the liquid level tension of the second cleaning liquid are smaller than the liquid level tension of the cleaning liquid; liquid is discharged into the cleaning liquid through the first liquid inlet and the second liquid inlet, so that three-layer layered liquid including the cleaning liquid, the second solution layer and the first solution layer from bottom to top can be formed. The second solution layer and the first solution layer are formed on the cleaning liquid, so that the liquid level is ensured to be flat, and the chip is prevented from being damaged in the cleaning process.

Description

Technical Field

[0001] The present invention relates to the technical field related to liquid cleaning of semiconductor devices, and in particular to a cleaning device and a cleaning method based on a MEMS chip. Background Art

[0002] During the whole chip processing process, etching, cleaning and other steps are required; when the MEMS chip is put into the cleaning solution for cleaning or taken out of the cleaning solution after cleaning, the liquid surface will be uneven, thus generating tension (such as Figure 1 As shown in the figure, since the diaphragm of the chip is thin, the thickness of the diaphragm is nanometer-level, generally the thickness of the diaphragm is less than 50nm, and the size of the diaphragm is about 5*5cm, the tension will damage the chip. After searching the existing methods to reduce the damage to the chip caused by the surface tension of the cleaning liquid, the current general situation is to change the formula of the cleaning liquid, and it is necessary to purchase or configure a new cleaning liquid before cleaning. Summary of the invention

[0003] In order to solve the technical problems existing in the background technology, the present invention proposes a cleaning device and a cleaning method based on a MEMS chip.

[0004] The present invention proposes a cleaning device based on a MEMS chip, which is used for cleaning the MEMS chip. The MEMS chip includes a diaphragm with a thickness of 10-30 nm. The device includes a containing tank, in which a cleaning liquid for cleaning the chip is contained. The cleaning liquid can be water. A first liquid inlet and a second liquid inlet are provided on the side of the containing tank. The heights of the first liquid inlet and the second liquid inlet are higher than the liquid level of the cleaning liquid.

[0005] The liquid discharged from the first liquid inlet is a first solution, the liquid discharged from the second liquid inlet is a second solution, and the liquid surface tension of the first cleaning liquid and the liquid surface tension of the second cleaning liquid are smaller than the liquid surface tension of the cleaning liquid;

[0006] By discharging liquid (including the first solution and the second solution) into the cleaning liquid through the first liquid inlet and the second liquid inlet, three layers of stratified liquid can be formed from bottom to top, namely, the cleaning liquid, the second solution layer and the first solution layer. The three layers of stratified liquid can be interpreted as three layers of liquid that are not fully mixed and stratified within a certain period of time, similar to a stratified cocktail.

[0007] The present invention forms three layers of different liquids with different surface tensions. The surface tensions of the first solution and the second solution are both smaller than the surface tension of the cleaning liquid. The three layers of stratified liquid are formed to keep the liquid surface flat, thereby preventing the chip from being damaged.

[0008] As a further optimized solution of the present invention, the height of the first liquid inlet is higher than the height of the second liquid inlet.

[0009] As a further optimized solution of the present invention, the density of the first solution is less than the density of the second solution.

[0010] As a further optimized solution of the present invention, the first solution is an IPA solution.

[0011] As a further optimized solution of the present invention, the second solution is an NMP solution.

[0012] As a further optimized solution of the present invention, the first liquid inlet and the second liquid inlet are located on the same side of the containing tank.

[0013] A cleaning method based on MEMS chip includes the above-mentioned cleaning device, and forms three layers of stratified liquid from bottom to top in the receiving tank, namely, cleaning liquid, second solution layer and first solution layer by controlling the flow rate of the first liquid inlet and the second liquid inlet.

[0014] As a further optimized solution of the present invention, when the chip is placed in the cleaning solution and / or the chip is taken out of the cleaning solution, three layers of stratified liquid, namely, the cleaning solution, the second solution layer and the first solution layer, are formed in the holding tank from bottom to top.

[0015] As a further optimized solution of the present invention, during the cleaning process, the chip is located below the liquid level of the cleaning liquid. When the chip is located below the liquid level of the cleaning liquid for cleaning, the flow rate of the first liquid inlet and the second liquid inlet can be 0, thereby reducing the cost; of course, in order to ensure a better cleaning effect, during the entire cleaning process, technical personnel in this field can ensure that the liquid in the cleaning tank is a three-layered liquid of the cleaning liquid, the second solution layer and the first solution layer.

[0016] In the present invention, a cleaning device and a cleaning method based on a MEMS chip are proposed. Now a layer of a second solution is added to the surface of the cleaning liquid, and then a first solution is added to the second solution layer to form a first solution layer to form a three-layered solution. The liquid surface tension of the first solution and the second solution is less than the liquid surface tension of the cleaning liquid, so that the liquid surface remains flat and the chip is prevented from being damaged during the cleaning process.

[0017] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The uneven state of the liquid surface caused by the liquid surface tension when the chip is placed in or taken out of the cleaning liquid in the prior art;

[0019] Figure 2 This is a structural schematic diagram of Embodiment 1 of the present invention;

[0020] Figure 3 A three-layered solution formed in the present invention;

[0021] Figure 4 This is a structural diagram of Embodiment 2 of the present invention;

[0022] Figure 5 This is a structural diagram of Embodiment 3 of the present invention;

[0023] Figure 6 This is a structural diagram of Embodiment 4 of the present invention;

[0024] Figure 7 A schematic diagram of the structure of the MEMS chip cleaned by the present invention;

[0025] In the figure: 1. containing tank; 2. first liquid inlet; 3. second liquid inlet; 4. liquid outlet; 5. first solution layer; 6. second solution layer. DETAILED DESCRIPTION

[0026] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar symbols throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0027] like Figure 2 A cleaning device based on a MEMS chip is shown, which is used for cleaning Figure 7 The chip shown in the figure is cleaned, comprising a containing tank 1, the containing tank 1 contains a cleaning liquid for cleaning the chip, the cleaning liquid can be water, and the side of the containing tank 1 is provided with a first liquid inlet 2 and a second liquid inlet 3, and the height of the first liquid inlet 2 and the second liquid inlet 3 is higher than the liquid level of the cleaning liquid;

[0028] The liquid discharged from the first liquid inlet 2 is a first solution, and the liquid discharged from the second liquid inlet 3 is a second solution. The surface tension of the first cleaning liquid and the surface tension of the second cleaning liquid are smaller than the surface tension of the cleaning liquid.

[0029] By discharging liquid into the cleaning liquid through the first liquid inlet 2 and the second liquid inlet 3, three layers of stratified liquid (such as the cleaning liquid, the second solution layer 6 and the first solution layer 5) can be formed from bottom to top. Figure 3As shown), the three-layered liquid can be interpreted as three layers of liquid that are not fully mixed and are stratified within a certain period of time, similar to a layered cocktail. Specifically, the second solution can be injected into the cleaning liquid to form a second solution layer 6, and then the first solution can be injected onto the second solution layer 6. The flow rates of the first liquid inlet 2 and the second liquid inlet 3 are controlled between 1mm / min-10mm / min. In this embodiment, the flow rates of the first liquid inlet 2 and the second liquid inlet 3 are 1mm / min.

[0030] Preferably, the maximum height of the second solution layer 6 is h1, and the height of the first solution layer 5 is h2, then the height from the first liquid inlet 2 to the cleaning liquid is slightly less than h1, and the height from the first liquid inlet 2 to the cleaning liquid is slightly less than h1+h2; the first solution and the second solution are both dissolved in the cleaning liquid, and then when the liquid level of the second cleaning liquid reaches h1, the speed of injecting the second solution is almost equal to the speed at which the second solution dissolves in water. Preferably, a liquid outlet 4 is also provided at the bottom of the holding tank 1. When the height of the second solution layer 6 reaches the maximum and the height of the first solution layer 5 reaches the maximum, the liquid outlet 4 starts to discharge the cleaning liquid, and the flow rate of the cleaning liquid discharged from the liquid outlet 4 is equal to the sum of the speeds of the first liquid inlet 2 and the second liquid inlet 3 discharging the liquid, thereby ensuring that during the injection of the first solution and the second solution, the second solution in the second liquid inlet 3 will not be injected into the cleaning liquid (the cleaning liquid here includes the cleaning liquid in the original holding tank 1 and also includes the cleaning liquid mixed with the first solution and the second solution), and the first solution in the first liquid inlet 2 will not be directly injected into the second solution layer 6.

[0031] The present invention forms three layers of different liquids with different surface tensions. The surface tensions of the first solution and the second solution are both smaller than the surface tension of the cleaning liquid. The three layers of stratified liquid are formed to keep the liquid surface flat, thereby preventing the chip from being damaged.

[0032] As a further optimized solution of the present invention, the density of the first solution is less than the density of the second solution, and both the first solution and the second solution are dissolved in the cleaning liquid. In this embodiment, the first solution is an IPA solution, the second solution is an NMP solution, and the first liquid inlet 2 and the second liquid inlet 3 are located on the same side of the containing tank 1, thereby ensuring the formation of a three-layer stratified liquid.

[0033] A cleaning method based on a MEMS chip, comprising a cleaning device as above, wherein three layers of stratified liquids, namely, a cleaning liquid, a second solution and a first solution, are formed in a containing tank 1 from bottom to top by controlling the flow rates of a first liquid inlet 2 and a second liquid inlet 3;

[0034] Specifically, firstly, a cleaning liquid is put into the containing tank 1 so that the liquid level of the cleaning liquid is h0;

[0035] Then, the second solution is discharged from the second liquid inlet 3 to the upper surface of the cleaning liquid in the holding tank 1 to form a second solution layer 6. Specifically, the second solution can be pumped to the second liquid inlet 3 through a pipeline and a pump. In order to control the flow rate of the second solution in the second liquid inlet 3, preferably, a valve is provided on the second liquid inlet 3 to control the flow rate of the second solution.

[0036] When the height of the second solution layer 6 is basically up to h1, the first solution is discharged from the first liquid inlet 2, preferably the flow rate of the first solution is equal to the flow rate of the second solution, and the flow rate of the liquid outlet 4 is equal to the flow rate of the second solution, until the first solution layer 5 forms a maximum liquid level height h2 on the second solution layer 6. At this time, the flow rate of the liquid outlet 4 is equal to the sum of the flow rate of the first solution and the speed of the second solution, thereby ensuring the three-layer stratified liquid surface of the first solution layer 5, the second solution layer 6 and the cleaning solution.

[0037] When the chip is placed in the cleaning liquid and when the chip is taken out of the cleaning liquid, in order to ensure that the liquid surface is as flat as possible, three layers of stratified liquid are formed in the receiving tank 1 from bottom to top, namely, the cleaning liquid, the second solution layer 6 and the first solution layer 5. At this time, the first liquid inlet 2 and the second liquid inlet 3 both discharge liquid into the cleaning tank and the liquid outlet 4 also discharges the cleaning liquid, thereby ensuring the formation of the three-layered liquid.

[0038] During the cleaning process, the chip is located below the liquid level of the cleaning liquid. When the chip is located below the liquid level of the cleaning liquid for cleaning, the flow rate of the first liquid inlet 2 and the second liquid inlet 3 can be 0, thereby reducing costs; of course, in order to ensure a better cleaning effect, during the entire cleaning process, technical personnel in this field can ensure that the liquid in the cleaning tank is a three-layered liquid of the cleaning liquid, the second solution layer 6 and the first solution layer 5.

[0039] Embodiment 2

[0040] like Figure 4 As shown, the difference between this embodiment and the above embodiment is that: in this embodiment, there are multiple first liquid inlets 2 and second liquid inlets 3, the central axes of the multiple first liquid inlets 2 are located in the same horizontal plane, the central axes of the multiple second liquid inlets 3 are located in the same horizontal plane, and one second liquid inlet 3 is located directly below one first liquid inlet 2, so as to facilitate the formation of three-layered liquid.

[0041] Embodiment 3

[0042] like Figure 5As shown, the difference between this embodiment and the above-mentioned embodiment is that in this embodiment, the first side surface of the containing tank 1 is provided with a first liquid inlet 2 and a second liquid inlet 3, and the second side surface of the containing tank 1 is also provided with a first liquid inlet 2 and a second liquid inlet 3, the first side surface and the second side surface are parallel and opposite to each other, the first liquid inlet 2 on the first side surface is opposite to the first liquid inlet 2 on the second side surface, and the second liquid inlet 3 on the second side surface is opposite to the second liquid inlet 3 on the first side surface.

[0043] Embodiment 4

[0044] like Figure 6 As shown, the difference between this embodiment and the above embodiment is that the receiving tank 1 is cylindrical, and a plurality of first liquid inlets 2 and second liquid inlets 3 are provided, and the plurality of first liquid inlets 2 are evenly distributed circumferentially on the inner side surface of the receiving tank 1, and the central axes of the plurality of first liquid inlets 2 are in the same horizontal plane, and the plurality of second liquid inlets 3 are evenly distributed circumferentially on the inner side surface of the receiving tank 1, and the central axes of the plurality of second liquid inlets 3 are in the same horizontal plane, and one first liquid inlet 2 is located directly above one second liquid inlet 3.

[0045] It should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0046] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0047] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0048] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A cleaning device based on a MEMS chip, comprising a containing tank (1), wherein the containing tank (1) contains a cleaning liquid for cleaning the chip, characterized in that: A first liquid inlet (2) and a second liquid inlet (3) are provided on the side of the containing tank (1), and the heights of the first liquid inlet (2) and the second liquid inlet (3) are higher than the liquid level of the cleaning liquid; The liquid discharged from the first liquid inlet (2) is a first solution, the liquid discharged from the second liquid inlet (3) is a second solution, and the liquid surface tension of the first cleaning liquid and the liquid surface tension of the second cleaning liquid are smaller than the liquid surface tension of the cleaning liquid; By discharging liquid into the cleaning liquid through the first liquid inlet (2) and the second liquid inlet (3), three layers of stratified liquid can be formed from bottom to top, namely, the cleaning liquid, the second solution layer (6) and the first solution layer (5).

2. The cleaning device based on MEMS chip according to claim 1, characterized in that: The height of the first liquid inlet (2) is higher than the height of the second liquid inlet (3).

3. The cleaning device based on MEMS chip according to claim 1 or 2, characterized in that: The density of the first solution is less than the density of the second solution.

4. The cleaning device based on MEMS chip according to claim 1, characterized in that: The first solution is an IPA solution.

5. The cleaning device based on MEMS chip according to claim 1, characterized in that: The second solution is a NMP solution.

6. The cleaning device based on MEMS chip according to claim 1, characterized in that: The first liquid inlet (2) and the second liquid inlet (3) are located on the same side of the containing tank (1).

7. A cleaning method based on MEMS chip, characterized in that: The cleaning device comprises the cleaning device as described in any one of claims 1 to 6, wherein the flow rates of the first liquid inlet (2) and the second liquid inlet (3) are controlled so that three layers of stratified liquid, namely, the cleaning liquid, the second solution layer (6) and the first solution layer (5) are formed from bottom to top in the containing tank (1).

8. The cleaning device based on MEMS chip according to claim 7, characterized in that: When the chip is placed in the cleaning liquid and / or taken out of the cleaning liquid, three layers of stratified liquid, namely, the cleaning liquid, the second solution layer (6) and the first solution layer (5) are formed in the containing tank (1) from bottom to top.

9. The cleaning device based on MEMS chip according to claim 7, characterized in that: When the chip is cleaned in a cleaning solution, three layers of stratified liquid, namely, the cleaning solution, the second solution layer (6) and the first solution layer (5) are formed in the containing tank (1) from bottom to top.

10. The cleaning device based on MEMS chip according to claim 7, characterized in that: During the cleaning process the chip is below the level of the cleaning solution.

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