Wafer processing fluid spraying method and apparatus

Abstract

The present application provides a wafer processing liquid spraying method and device, the wafer processing liquid spraying method comprises the following steps: providing a wafer with a film on the surface, the film surface has a blind hole; driving the wafer to alternately perform forward and reverse rotation; using a first nozzle to spray cleaning liquid to the wafer; the wafer processing liquid spraying method and device can clean etching liquid in the wafer blind hole, and reduce the loss amount of material in the wafer blind hole.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a wafer processing liquid spraying method and device. Background Art

[0002] During the semiconductor device manufacturing process, wafer cleaning is often necessary, especially after the etching process. When blind vias exist in thin films deposited on the wafer surface, etching of unnecessary structures on the wafer surface can cause etchant to remain in the blind vias. If the etchant is not thoroughly cleaned, the desired material within the blind vias may be etched away, resulting in excessive material loss and ultimately impacting product performance.

[0003] Therefore, it is necessary to develop a novel treatment liquid spraying method and device to improve some of the above problems existing in the prior art. Summary of the Invention

[0004] The object of the present invention is to provide a wafer processing liquid spraying method and device, which can improve the cleaning effect of the etching liquid in the wafer blind hole and reduce the material loss in the wafer blind hole.

[0005] To achieve the above-mentioned purpose, the present invention provides a wafer processing liquid spraying method, comprising the following steps: providing a wafer with a thin film on its surface, wherein the thin film surface has blind holes; driving the wafer to alternately rotate forward and reverse; and using a first nozzle to spray cleaning liquid onto the wafer.

[0006] The beneficial effect of the wafer processing liquid spraying method provided by the present invention is that: by rotating the wafer with blind holes on the surface film forward and backward, the movement direction of the cleaning liquid on the wafer surface can be changed, and the cleaning liquid on the wafer surface has an oscillating effect, so that the cleaning liquid flows into the blind holes from multiple angles. The cleaning liquid can more fully replace the etching liquid in the blind holes, which is beneficial to improving the cleaning effect of the etching liquid in the holes, reducing the loss of required materials in the holes, and thus improving product performance.

[0007] Optionally, the method of spraying a cleaning liquid onto the wafer using a first nozzle includes: forming a first angle between the cleaning liquid flow and the wafer surface, the first angle being greater than or equal to 30° and less than 90°; and forming a second angle between the component of the cleaning liquid flow velocity on the wafer surface and the linear velocity of the cleaning liquid spraying point on the wafer surface, the second angle being greater than or equal to 0° and less than or equal to 45°. The method has the following beneficial effects: when the cleaning liquid flow forms the first angle with the wafer to rinse the wafer, when the blind hole on the wafer rotates and the linear velocity at right angles to the radius of the wafer, the cleaning liquid can more easily enter the hole than when the cleaning liquid flow is perpendicular to the wafer, thereby improving the cleaning effect of the etching liquid in the hole; when the component of the cleaning liquid flow velocity on the wafer surface and the linear velocity of the cleaning liquid spraying point on the wafer surface form the second angle, the cleaning liquid flow velocity and the linear velocity at the blind hole are nearly in the same direction, thereby reducing the speed difference between the two, making it easier for the cleaning liquid to enter the hole, thereby further improving the cleaning effect of the etching liquid in the hole.

[0008] Optionally, spraying the cleaning liquid onto the wafer using the first nozzle further includes: moving the first nozzle from one side above the wafer to the other side, and during the movement of the first nozzle, adjusting the angle of the first nozzle so that the flow rate of the cleaning liquid satisfies the first angle and the second angle. This advantageously facilitates overall cleaning of the wafer surface and improves the cleaning effect of blind vias at various locations.

[0009] Optionally, the alternating forward and reverse rotation includes: a forward rotation time of 10 to 60 seconds and a reverse rotation time of 10 to 60 seconds.

[0010] Optionally, before driving the wafer to alternately rotate forward and reverse, it also includes: using a second nozzle to spray etching liquid onto the wafer, forming a third angle between the liquid flow of the etching liquid and the surface of the wafer, and the third angle is greater than 0° and less than or equal to 60°; forming a fourth angle between the component of the liquid flow velocity of the etching liquid on the surface of the wafer and the linear velocity of the cleaning liquid spraying point on the surface of the wafer, and the fourth angle is greater than or equal to 135° and less than or equal to 180°. The effect is that: the etching liquid flow rinses the wafer in a manner of forming the third angle with the wafer. When the etching liquid contacts the wafer, a horizontal force parallel to the wafer surface can be added to the etching liquid flow, thereby reducing the amount of etching liquid entering the hole; at the same time, when the component of the etching liquid flow velocity on the wafer surface and the linear velocity of the etching liquid spraying point on the wafer surface form the second angle, the etching liquid flow velocity and the linear velocity at the blind hole are nearly opposite, thereby increasing the speed difference between the two. Part of the etching liquid flows from one side of the blind hole opening to the other side without entering the hole, which is beneficial to reducing the amount of etching liquid in the hole and facilitating the subsequent thorough cleaning of the residual etching liquid.

[0011] The wafer processing liquid spraying device provided by the present invention includes a rotating mechanism and a first nozzle; the rotating mechanism is used to carry the wafer and drive the wafer to alternately rotate forward and reverse; the first nozzle is arranged above the rotating mechanism and is used to spray cleaning liquid onto the wafer.

[0012] The beneficial effect of the wafer processing liquid spraying device provided by the present invention is that: the rotating mechanism carries and drives the forward and reverse rotation of the wafer with blind holes on the surface film. When the first nozzle is used to spray the cleaning liquid on the wafer, the forward and reverse rotation of the wafer can change the movement direction of the cleaning liquid on the wafer surface, and has an oscillating effect on the cleaning liquid on the wafer surface, so that the cleaning liquid flows into the blind hole from multiple angles. The cleaning liquid can more fully replace the etching liquid in the blind hole, which is beneficial to improving the cleaning effect of the etching liquid in the hole, reducing the loss of required materials in the hole, and thus improving product performance.

[0013] Optionally, the wafer processing liquid spraying device further includes a nozzle drive mechanism connected to the first nozzle, the nozzle drive mechanism being configured to drive the first nozzle from one side above the wafer to the other side. This advantageously facilitates overall cleaning of the wafer surface and improves the cleaning effect of blind vias at various locations.

[0014] Optionally, the wafer processing liquid spraying device further includes a nozzle adjustment mechanism connected to the first nozzle, the nozzle adjustment mechanism being configured to adjust the angle of the first nozzle to change the direction of the cleaning liquid flow. This advantageously allows the cleaning liquid to more easily enter the blind via and rinse the wafer, thereby improving the cleaning effect of the etching liquid within the blind via.

[0015] Optionally, the wafer processing liquid spraying device further includes a second nozzle disposed above the rotating mechanism for spraying etching liquid onto the wafer.

[0016] Optionally, the second nozzle is connected to the nozzle drive mechanism and the nozzle adjustment mechanism, and is used to drive the second nozzle from one side above the wafer to the other side and adjust the angle of the second nozzle to change the direction of the etching liquid flow. This has the beneficial effect of: the nozzle drive mechanism adjusts the position of the second nozzle to facilitate the overall etching of the wafer surface; at the same time, the nozzle adjustment mechanism adjusts the angle of the second nozzle to reduce the amount of etching liquid entering the blind hole, thereby facilitating the subsequent cleaning of the etching liquid in the blind hole. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the structure of a wafer processing liquid spraying device according to an embodiment of the present invention;

[0018] Figure 2 Schematic diagram of the positions of wafers and cleaning liquid flows in an embodiment of the present invention;

[0019] Figure 3 Schematic diagram of the positions of the wafer and the etching solution flow in an embodiment of the present invention;

[0020] Figure 4 for Figure 2 Schematic diagram of the positions of components of the cleaning liquid flow velocity on the wafer surface;

[0021] Figure 5 for Figure 3 Schematic diagram of the position of components of the etching solution flow velocity on the wafer surface;

[0022] Figure 6 A cross-sectional view of a blind hole in the center area of ​​a wafer before etching according to an embodiment of the present invention;

[0023] Figure 7 A cross-sectional view of a blind hole in a wafer edge region before etching according to an embodiment of the present invention;

[0024] Figure 8 A cross-sectional view of a blind hole in the center of a wafer after etching according to an embodiment of the present invention;

[0025] Figure 9 A sectional view of a blind hole position at an edge region of a wafer after etching according to an embodiment of the present application;

[0026] Figure 10 A flow chart of a wafer processing liquid spraying method according to an embodiment of the present application. DETAILED DESCRIPTION

[0027] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions of the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts should fall within the scope of the present application. Unless otherwise defined, the technical terms or scientific terms used herein should be interpreted as their common meanings understood by those of ordinary skill in the art to which the present application belongs. The terms such as “comprise” and the like used herein are intended to encompass the elements or objects appearing before the terms as well as their equivalents and other elements or objects.

[0028] To solve the problems in the prior art, with reference to Figure 10 The embodiments of the present application provide a wafer processing liquid spraying method, which comprises the following steps:

[0029] S01: providing a wafer with a film on the surface, wherein the film surface has a blind hole;

[0030] S02: driving the wafer to alternately perform forward rotation and reverse rotation;

[0031] S03: spraying cleaning liquid to the wafer by using a first nozzle.

[0032] Specifically, in the S01 step, the wafer can be first sputtered with a copper-titanium seed layer on the wafer surface by using a Sputter process, and then a redistribution layer is made by electroplating copper process, wherein the redistribution layer has a blind hole structure; when the copper-titanium seed layer needs to be etched, the copper material of the redistribution layer will be lost, in order to reduce the copper loss, the surface copper material height can be reserved, but the copper material in the hole itself is relatively small in thickness compared with the surface copper material in the process.

[0033] Specifically, in the S02 step, the wafer is driven to alternately perform forward rotation and reverse rotation around the axis thereof.

[0034] Specifically, in the S03 step, the cleaning liquid can be deionized water.

[0035] In some embodiments of the present invention, since the size of the blind hole is much smaller than the area of ​​the processing liquid spraying point, the processing liquid spraying point covers several of the blind holes; at the same time, in order to facilitate understanding by technical personnel and the general public in theory and practice, the linear velocity direction of the processing liquid spraying point on the wafer surface is equated with the linear velocity direction at the position of the blind hole.

[0036] In some embodiments of the present invention, referring to Figure 2 and Figure 4 , the step S03 of using the first nozzle to spray the cleaning liquid 6 onto the wafer also includes: forming a first angle, namely, angle α shown in the figure, between the liquid flow of the cleaning liquid 6 and the surface of the wafer, the first angle is greater than or equal to 30° and less than 90°, the liquid flow direction of the cleaning liquid 6 is direction B shown in the figure, and the linear velocity direction at the blind hole is direction A shown in the figure; forming a second angle between the component of the liquid flow velocity of the cleaning liquid 6 on the surface of the wafer and the linear velocity of the cleaning liquid spraying point on the surface of the wafer, the second angle is greater than or equal to 0° and less than or equal to 45°.

[0037] In some specific embodiments of the present invention, the first angle may be 30°, 35°, 40°, 45°, 50°, 55°, 60°, 65°, 70°, 75°, 80°, 85° or 89°.

[0038] In some specific embodiments of the present invention, the second angle may be 0°, 5°, 10°, 15°, 20°, 25°, 30°, 35°, 40° or 45°.

[0039] Specifically, refer to Figure 2 and Figure 4 The component of the flow velocity of the cleaning liquid on the surface of the wafer can be located in the range of 0° to 45° on the clockwise side of the linear velocity of the cleaning liquid spraying point, or can be located in the range of 0° to 45° on the counterclockwise side of the cleaning liquid spraying point. The component of the flow velocity of the cleaning liquid on the surface of the wafer is component B1 and component B2 at the two extreme positions on both sides of the linear velocity direction of the cleaning liquid spraying point when γ1=γ2=45°, and the angle between component B1 and component B2 is 90°.

[0040] In some specific embodiments of the present invention, referring to Figure 1 , the step S03 of using the first nozzle to spray the cleaning liquid onto the wafer also includes: moving the position of the first nozzle so that the first nozzle moves from one side above the position of the wafer to the other side, that is, from the E side in the figure to the F side in the figure, and with the rotation of the wafer, the cleaning liquid is sprayed on the entire surface of the wafer; during the movement of the first nozzle, the angle of the first nozzle is adjusted so that the flow rate of the cleaning liquid satisfies the first angle and the second angle.

[0041] In some embodiments of the present invention, the time for alternating forward and reverse rotation is 10 to 60 seconds for forward rotation and 10 to 60 seconds for reverse rotation.

[0042] Specifically, the forward rotation time is 10 seconds, 20 seconds, 30 seconds, 40 seconds, 50 seconds or 60 seconds.

[0043] Specifically, the reversal time is 10 seconds, 20 seconds, 30 seconds, 40 seconds, 50 seconds or 60 seconds.

[0044] In some embodiments of the present invention, referring to Figure 3 and Figure 5 Before driving the wafer to rotate alternately forward and reverse in step S02, the method further includes: spraying an etching liquid 7 onto the wafer using a second nozzle, wherein a third angle, namely, angle β as shown in the figure, is formed between the flow of the etching liquid 7 and the wafer surface, wherein the third angle is greater than 0° and less than or equal to 60°, the flow direction of the etching liquid 7 is direction D as shown in the figure, and the linear velocity direction at the blind hole is direction C as shown in the figure; and a fourth angle is formed between a component of the flow velocity of the etching liquid 7 on the wafer surface and the linear velocity of the etching liquid spraying point on the wafer surface, wherein the fourth angle is greater than or equal to 135° and less than or equal to 180°.

[0045] In some specific embodiments of the present invention, the third angle is 1°, 15°, 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55° or 60°.

[0046] In some specific embodiments of the present invention, the fourth angle is 135°, 140°, 145°, 150°, 155°, 160°, 165°, 170°, 175° or 180°.

[0047] Specifically, refer to Figure 3 and Figure 5 The component of the flow velocity of the etching liquid on the wafer surface can be located in the range of 135° to 180° on the clockwise side of the linear velocity of the etching liquid spraying point, or can be located in the range of 135° to 180° on the counterclockwise side of the etching liquid spraying point. The component of the flow velocity of the etching liquid on the wafer surface is the component D1 and the component D2 at the two extreme positions on both sides of the linear velocity direction of the etching liquid spraying point when θ1=θ2=135°, and the angle between the component D1 and the component D2 is 90°.

[0048] In some embodiments of the present invention, when the wafer rotates alternately forward and reverse, the first nozzle or the second nozzle changes the flow direction of the cleaning liquid or the etching liquid according to the rotation direction of the wafer during movement, so that the flow direction of the cleaning liquid or the etching liquid satisfies the first angle and the second angle or the third angle or the fourth angle.

[0049] In some embodiments of the present invention, the wafer processing liquid spraying method further includes step S04: driving the wafer to rotate and spraying the wafer with nitrogen to dry the wafer surface.

[0050] Reference Figures 6 to 9 Before etching, the film thickness outside the blind vias in the wafer center area was L1 = 8.3627μm, and the film thickness inside the bottom of the blind vias was L2 = 3.2600μm. At the wafer edge area, the film thickness outside the blind vias was L3 = 7.5123μm, and the film thickness inside the bottom of the blind vias was L4 = 3.1183μm. After etching, the film thickness outside the blind vias in the wafer center area was L5 = 6.5201μm, and the film thickness inside the bottom of the blind vias was L6 = 3.12μm. At the wafer edge area, the film thickness outside the blind vias was L7 = 5.8114μm, and the film thickness inside the bottom of the blind vias was L8 = 3.04μm.

[0051] Reference Figures 6 to 9 It can be seen that the loss of thin film material inside the blind hole before and after the etching process is less than the loss of thin film material outside the blind hole, which effectively improves the cleaning effect of the etching solution in the hole, reduces the loss of required material in the hole, and thus improves product performance.

[0052] The embodiment of the present invention provides a wafer processing liquid spraying device, referring to Figure 1 , used to implement the above-mentioned wafer processing liquid spraying method, the structure and principle of the wafer processing liquid spraying device correspond one-to-one to the steps in the above-mentioned wafer processing liquid spraying method.

[0053] In some embodiments of the present invention, referring to Figure 1 The wafer processing liquid spraying device includes a rotating mechanism 2 and a first nozzle 1; the rotating mechanism 2 is used to carry the wafer 3 and drive the wafer 3 to alternately rotate forward and reverse; the first nozzle 1 is arranged above the rotating mechanism 2 and is used to spray the cleaning liquid 6 onto the wafer 3.

[0054] In some specific embodiments of the present invention, referring to Figure 1 By placing the wafer 3 on the carrier platform of the rotating mechanism 2, the rotating mechanism 2 drives the carrier platform to rotate and thereby drives the wafer 3 to rotate forward and reverse alternately around its axis.

[0055] In some embodiments of the present invention, referring to Figure 1The wafer processing liquid spraying device also includes a nozzle driving mechanism 5 connected to the first nozzle 1, and the nozzle driving mechanism 5 is used to drive the first nozzle 1 to move from one side above the position of the wafer 3 to the other side, that is, from the E side in the figure to the F side in the figure.

[0056] Specifically, refer to Figure 1 The nozzle driving mechanism 5 is driven by a motor and can drive the first nozzle 1 to perform linear motion in a plane that is a certain distance above the supporting platform and parallel to the upper surface of the supporting platform.

[0057] In some embodiments of the present invention, referring to Figure 1 The wafer processing liquid spraying device also includes a nozzle adjustment mechanism 4 connected to the first nozzle 1, and the nozzle adjustment mechanism 4 is used to adjust the angle of the first nozzle 1 to change the direction of the flow of the cleaning liquid 6.

[0058] Specifically, the wafer processing liquid spraying device further includes an industrial camera disposed on the top of the device for acquiring the position of the spraying point of the processing liquid on the wafer 3 , wherein the processing liquid includes a cleaning liquid 6 and an etching liquid 7 .

[0059] Specifically, the linear velocity direction of the spraying point is determined by the spraying point and the center of the wafer 3 .

[0060] Specifically, the nozzle adjustment mechanism 4 has the freedom to rotate around two mutually perpendicular rotation axes to adjust the first nozzle 1 and thereby change the sizes of the first angle and the second angle.

[0061] In some embodiments of the present invention, the wafer processing liquid spraying device further includes a second nozzle disposed above the rotating mechanism 2 , and the second nozzle is used to spray the etching liquid 7 onto the wafer 3 .

[0062] In some embodiments of the present invention, the second nozzle is connected to the nozzle driving mechanism 5 and the nozzle adjustment mechanism 4, and is used to drive the second nozzle to move from one side above the position of the wafer 3 to the other side and adjust the angle of the second nozzle to change the direction of the flow of the etching liquid 7. The movement mode of the second nozzle is the same as that of the first nozzle 1.

[0063] While the embodiments of the present invention have been described in detail above, it will be apparent to those skilled in the art that various modifications and variations of these embodiments are possible. However, it should be understood that such modifications and variations are within the scope and spirit of the present invention as set forth in the claims. Furthermore, the invention described herein is susceptible to other embodiments and may be practiced or implemented in a variety of ways.

Claims

1. A wafer processing liquid spraying method, characterized in that: The steps include: Providing a wafer with a thin film on its surface, wherein the thin film surface has a blind hole; Driving the wafer to rotate forward and reverse alternately; A first nozzle is used to spray cleaning liquid onto the wafer, and a first angle is formed between the liquid flow of the cleaning liquid and the surface of the wafer, and the first angle is greater than or equal to 30° and less than 90°; a second angle is formed between the component of the liquid flow velocity of the cleaning liquid on the surface of the wafer and the linear velocity of the cleaning liquid spraying point on the surface of the wafer, and the second angle is greater than or equal to 0° and less than or equal to 45°.

2. The wafer processing liquid spraying method according to claim 1, characterized in that: The method of spraying the cleaning liquid onto the wafer using the first nozzle further includes: Move the position of the first nozzle from one side above the wafer to the other side. During the movement of the first nozzle, adjust the angle of the first nozzle so that the flow rate of the cleaning liquid satisfies the first angle and the second angle.

3. The wafer processing liquid spraying method according to claim 1, characterized in that: The alternating forward and reverse rotation includes: the forward rotation time is 10 to 60 seconds and the reverse rotation time is 10 to 60 seconds.

4. The wafer processing liquid spraying method according to claim 1, characterized in that: Before driving the wafer to alternately rotate forward and reverse, it also includes: using a second nozzle to spray etching liquid onto the wafer, forming a third angle between the liquid flow of the etching liquid and the surface of the wafer, and the third angle is greater than 0° and less than or equal to 60°; forming a fourth angle between the component of the liquid flow velocity of the etching liquid on the surface of the wafer and the linear velocity of the cleaning liquid spraying point on the surface of the wafer, and the fourth angle is greater than or equal to 135° and less than or equal to 180°.

5. A wafer processing liquid spraying device, characterized in that: The wafer processing liquid spraying method according to any one of claims 1 to 4 comprises: A rotating mechanism, used to carry the wafer and drive the wafer to rotate alternately forward and reverse; A first nozzle is disposed above the rotating mechanism and is used for spraying cleaning liquid onto the wafer.

6. The wafer processing liquid spraying device according to claim 5, characterized in that: It also includes a nozzle driving mechanism connected to the first nozzle, and the nozzle driving mechanism is used to drive the first nozzle to move from one side above the position of the wafer to the other side.

7. The wafer processing liquid spraying device according to claim 6, characterized in that: It also includes a nozzle adjustment mechanism connected to the first nozzle, and the nozzle adjustment mechanism is used to adjust the angle of the first nozzle to change the direction of the flow of the cleaning liquid.

8. The wafer processing liquid spraying device according to claim 7, characterized in that: It also includes a second nozzle arranged above the rotating mechanism, which is used to spray etching liquid onto the wafer.

9. The wafer processing liquid spraying device according to claim 8, characterized in that: The second nozzle is connected to the nozzle driving mechanism and the nozzle adjusting mechanism, and is used to drive the second nozzle to move from one side above the wafer to the other side and adjust the angle of the second nozzle to change the direction of the etching liquid flow.

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