Wafer cleaning apparatus and method

Abstract

The application discloses a wafer cleaning device and method, which comprises a rotating table for placing a wafer, a cleaning liquid nozzle arranged above the center position of the wafer, a movable heating device for heating the surface of the wafer, a controller connected with the movable heating device, and the rotating table drives the wafer to rotate when the wafer is cleaned, the cleaning liquid nozzle sprays cleaning liquid to the center position of the wafer, and the controller controls the movable heating device to move relative to the wafer to heat the specific area of the wafer surface. The above scheme can improve the temperature difference of the wafer surface, improve the corrosion rate difference caused by the temperature difference of different areas in the wafer, and ensure the cleaning corrosion effect of the wafer.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to a wafer cleaning apparatus and method. Background Technology

[0002] In semiconductor manufacturing, wafer cleaning and wet etching are among the most commonly used processes. A typical wafer cleaning system sprays cleaning fluid onto the center of the wafer, which then rotates at high speed on a rotary table. This allows the cleaning fluid to flow to various points on the wafer surface, performing wet etching and cleaning.

[0003] However, in the existing technology, the corrosion rate of the cleaning solution on the object to be cleaned varies at different locations on the wafer surface, resulting in poor wafer etching effect. Summary of the Invention

[0004] This application provides a wafer cleaning apparatus and method, which solves the technical problem of different corrosion rates caused by different temperatures at different locations on the wafer in the prior art, and achieves the technical effect of balancing the corrosion rate at different locations on the wafer to improve the corrosion uniformity within the wafer.

[0005] In a first aspect, embodiments of this specification provide a wafer cleaning apparatus, the apparatus comprising:

[0006] A rotating stage, used to place wafers;

[0007] The cleaning fluid nozzle is positioned above the center of the wafer;

[0008] A portable heating device is used to heat the surface of the wafer;

[0009] The controller is connected to the portable heating device;

[0010] During the cleaning of the wafer, the rotary table drives the wafer to rotate, the cleaning fluid nozzle sprays cleaning fluid towards the center of the wafer, and the controller controls the movable heating device to move relative to the wafer to heat the wafer surface.

[0011] Optionally, the device further includes:

[0012] A temperature sensor is used to detect the center temperature at the center of the wafer and the target temperature at a target location on the wafer, wherein the target location is different from the center of the wafer.

[0013] The controller is configured to move the movable heating device to the target position to heat the target position when the temperature difference between the center temperature and the target temperature is greater than a preset value.

[0014] Optionally, the movable heating device includes a heating element and an adjusting element for moving the heating element;

[0015] The controller is used to adjust the regulating component to move the heating component to the target position when the temperature difference between the center temperature and the target temperature is greater than a preset value.

[0016] Optionally, the adjusting component is a connecting rod that can swing on the wafer surface, and one end of the connecting rod is connected to the heating component;

[0017] The controller is used to adjust the swing angle of the connecting rod to move the heating component to the target position when the temperature difference between the center temperature and the target temperature is greater than a preset value.

[0018] Optionally, the adjusting component is a telescopic rod that can extend and retract along the radius of the wafer, and one end of the telescopic rod is connected to the heating component;

[0019] The controller is used to adjust the extension length of the telescopic rod to move the heating component to the target position when the temperature difference between the center temperature and the target temperature is greater than a preset value.

[0020] Optionally, the heating power of the portable heating device is adjustable;

[0021] The controller is used to determine the target heating power of the portable heating device based on the temperature difference between the center temperature and the target temperature.

[0022] The movable heating device is used to heat the target location with the target heating power.

[0023] Optionally, the target location is a position between the center of the wafer and the edge of the wafer;

[0024] The movable heating device is used to heat the annular region where the target position is located during the process of the rotating table driving the wafer to rotate.

[0025] Secondly, embodiments of this specification provide a wafer cleaning method applied to a wafer cleaning apparatus, the wafer cleaning apparatus including a rotary table, a cleaning fluid nozzle, a movable heating device, and a controller, the method comprising:

[0026] When cleaning the wafer placed on the rotating stage, the rotating stage is activated to rotate the wafer;

[0027] The cleaning solution is sprayed onto the center of the wafer through the cleaning solution nozzle;

[0028] The controller controls the movable heating device to move relative to the wafer in order to heat the surface of the wafer.

[0029] Optionally, controlling the movable heating device to move relative to the wafer via the controller to heat the wafer surface includes:

[0030] The center temperature at the center of the wafer is obtained, and the target temperature at a target location on the wafer is obtained, wherein the target location is different from the center of the wafer;

[0031] When the temperature difference between the center temperature and the target temperature is greater than a preset value, the controller controls the movable heating device to move to the target position to heat the target position.

[0032] Optionally, controlling the movable heating device to move relative to the wafer via the controller to heat the wafer surface includes:

[0033] The controller controls the movable heating device to move back and forth between the center of the wafer and the edge of the wafer to heat the area between the center of the wafer and the edge of the wafer.

[0034] One or more technical solutions provided in the embodiments of this specification have at least the following technical effects or advantages:

[0035] This specification provides a wafer cleaning apparatus. A wafer is placed on a rotating stage, which rotates the wafer. Cleaning fluid is sprayed onto the center of the wafer through a nozzle positioned above the center to clean and etch the material to be cleaned from the wafer surface. A controller controls a movable heating device to move relative to the wafer, heating the wafer surface. During the wafer cleaning process, the cleaning fluid is continuously sprayed towards the center. The rotation of the wafer causes the cleaning fluid to flow from the center to the edge. Therefore, the temperature at the center of the wafer is higher, while the temperature near the edge is lower. Since the etching rate is temperature-dependent, the different temperatures at different locations on the wafer result in varying etching rates within the wafer. Therefore, this specification addresses this issue by controlling the movement of the movable heating device relative to the wafer to heat the wafer surface, reducing the temperature difference between different locations on the wafer surface. This improves upon the technical problem of varying etching rates caused by different temperatures at different locations in the prior art, balancing the etching rates at different locations on the wafer and thus improving the uniformity of etching within the wafer. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of a wafer cleaning apparatus provided in the first aspect of the embodiments of this specification;

[0038] Figure 2 A schematic diagram of the temperature distribution on a wafer surface provided in the embodiments of this specification;

[0039] Figure 3 A schematic diagram illustrating the swinging of a connecting rod on a wafer surface, as provided in an embodiment of this specification.

[0040] Figure 4 This is a flowchart of a wafer cleaning method provided as a second aspect of the embodiments of this specification. Detailed Implementation

[0041] Embodiments of the present disclosure will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the disclosure. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concepts of the present disclosure.

[0042] The accompanying drawings illustrate various structural schematics according to embodiments of the present disclosure. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0043] In the context of this disclosure, when a layer / element is referred to as being "above" another layer / element, the layer / element may be directly above the other layer / element, or there may be an intermediate layer / element between them. Additionally, if a layer / element is "above" another layer / element in one orientation, then when the orientation is reversed, the layer / element may be "below" the other layer / element.

[0044] Example 1

[0045] This specification provides an embodiment of a wafer cleaning apparatus, such as... Figure 1The diagram shown is a schematic of a wafer cleaning apparatus provided in an embodiment of this specification. The apparatus includes: a rotating stage 11, a cleaning fluid nozzle 12, a movable heating device 13, and a controller (not shown).

[0046] A rotating stage 11 is used to place the wafer; a cleaning fluid nozzle 12 is positioned above the center of the wafer; a movable heating device 13 is used to heat the surface of the wafer; and a controller is connected to the movable heating device 13. When cleaning the wafer, the rotating stage 11 drives the wafer to rotate, the cleaning fluid nozzle 12 sprays cleaning fluid towards the center of the wafer, and the controller controls the movable heating device 13 to move relative to the wafer to heat the surface of the wafer.

[0047] In the embodiments described in this specification, the wafer cleaning apparatus can be installed inside the cleaning chamber or set up independently as a separate device; no limitation is made here. The size and shape of the rotating stage 11 can be set according to actual needs. For example, the rotating stage 11 can be a cylindrical support platform, on which the wafer can be fixed and rotated as the rotating stage 11 rotates. The rotation speed of the rotating stage can also be set according to actual needs; no limitation is made here.

[0048] The cleaning fluid nozzle 12 is positioned above the center of the wafer. As the wafer rotates with the rotary table 11, the cleaning fluid nozzle sprays cleaning fluid towards the center of the wafer. Through the wafer's rotation, the cleaning fluid flows from the center to the edge of the wafer, etching the material to be cleaned. The type of cleaning fluid can be determined based on the type of material to be cleaned; it can be a solvent, acid, etc., and is not limited here. Generally, the cleaning fluid has a certain temperature. Therefore, during the wafer cleaning process, the temperature is highest at the center of the wafer, and the temperature gradually decreases from the center to the edge along the radius of the wafer. Furthermore, since temperature affects the etching rate, the etching rate at the center of the wafer will differ from the etching rate near the edge.

[0049] In this embodiment of the specification, in order to mitigate the differences in corrosion rates generated during wafer cleaning, a movable heating device 13 is provided to heat the wafer surface. In actual implementation, the method by which the controller moves the movable heating device 13 relative to the wafer and heats the wafer can be selected according to actual needs.

[0050] In one embodiment, since the surface temperature of the wafer decreases from the center to the edge, the controller can control the movable heating device 13 to move back and forth between the wafer center and the wafer edge. To balance the temperature of the wafer surface, the heating time of the movable heating device 13 at each heating position gradually increases when moving from the wafer center to the wafer edge, and conversely, the heating time of the movable heating device 13 at each heating position gradually decreases when moving from the wafer edge to the wafer center. This allows for longer heating times at lower temperature locations and shorter heating times at higher temperature locations, ensuring temperature uniformity across the wafer surface. The heating position is located between the wafer center and the wafer edge.

[0051] In another embodiment, the controller can control the movable heating device 13 to move back and forth between the center of the wafer and the edge of the wafer, and adjust the heating power of the movable heating device 13 during the movement to adjust the heating speed or heating temperature of the movable heating device 13. The heating power can be increased at the low temperature position and decreased at the high temperature position.

[0052] Of course, the heating of the wafer surface by the movable heating device 13 can also be controlled by other means, which are not limited here. In addition, the movable heating device 13 can be located above the wafer to heat the upper surface of the wafer, or it can be located below the wafer to heat the lower surface of the wafer. In the embodiments of this specification, the heating of the upper surface of the wafer is used as an example for explanation.

[0053] Furthermore, the wafer cleaning apparatus also includes: a temperature sensor for detecting the center temperature at the center of the wafer and the target temperature at a target location on the wafer, wherein the target location is different from the center of the wafer; and a controller for controlling the movable heating device 13 to move to the target location to heat the target location when the temperature difference between the center temperature and the target temperature is greater than a preset value.

[0054] In the embodiments of this specification, temperature sensors are used to collect the temperature at various locations on the wafer. The number of temperature sensors can be one or multiple, and their locations can be selected according to actual needs. For example, temperature sensors can be placed on the upper or lower surface of the wafer, etc., without limitation. The temperature sensors can collect the center temperature at the center location and the target temperature at a target location on the wafer. The target location is any location between the center location and the edge, and the number of target locations can be one or multiple.

[0055] In the embodiments described in this specification, since the cleaning fluid is sprayed towards the center of the wafer and flows towards the edge, the temperature on the wafer surface decreases from the center to the edge. For annular regions with the same radius, the temperatures within the annular region are similar. Figure 2 The diagram shown is a schematic representation of the temperature distribution on a wafer surface provided in an embodiment of this specification. Figure 2 In the process, the wafer is divided into four regions based on its surface temperature: the first region including the center, the second annular region, the third annular region, and the fourth annular region. For each region, the temperature at each location within the region is similar, that is, the temperature difference at any location within the same region is less than a threshold (this threshold can be set according to actual needs). Furthermore, the temperature of the first region is higher than that of the second annular region, the temperature of the second annular region is higher than that of the third annular region, and the temperature of the third annular region is higher than that of the fourth annular region.

[0056] The target location can be any location in any of the aforementioned regions except for the center location. In one embodiment, there are multiple target locations, each located in one of the other annular regions excluding the region containing the center location. That is, a target location is selected sequentially in each annular region, and the target temperature of the target location in each annular region represents the temperature of that annular region. Thus, since the wafer rotates under the drive of the rotary table 11, each annular region can be heated according to the target temperature of the target location in each annular region.

[0057] Furthermore, after obtaining the target temperature of the target area, the temperature difference between the target temperature and the center temperature is determined. If the temperature difference is greater than a preset value, it is determined that the temperature difference between the target temperature and the center temperature is large, and the target location needs to be heated. The preset value can be set according to actual needs and is not limited here. When heating of the target location is required, the movable heating device 13 is controlled to move to the target location to heat it, that is, to heat the annular area where the target location is located.

[0058] In addition, the temperature of the target location still needs to be continuously monitored during the heating process. Heating should be stopped when the temperature difference between the heated target location and the center temperature is less than or equal to the preset value.

[0059] In this embodiment of the specification, the movable heating device 13 includes a heating component and an adjustment component for moving the heating component; a controller is used to adjust the adjustment component to move the heating component to the target position when the temperature difference between the center temperature and the target temperature is greater than a preset value.

[0060] In practice, the heating element can be a lamp-type heater or other types of heating elements; no limitation is made here. The adjusting element can be selected according to actual needs; here, two examples will be used for illustration.

[0061] The first type has an adjustment component that is a connecting rod that can swing on the wafer surface, with one end of the connecting rod connected to a heating component; and a controller that adjusts the swing angle of the connecting rod to move the heating component to the target position when the temperature difference between the center temperature and the target temperature is greater than a preset value.

[0062] Specifically, one end of the connecting rod is connected to the heating element, while the other end is movable, such as via a rotating shaft. The connecting rod is connected to the controller, and the movable end of the connecting rod can swing around the rotating shaft on the wafer surface. Figure 3 The diagram shows the connecting rod oscillating on the wafer surface. When heating is required at a target location, the controller adjusts the oscillation angle of the connecting rod to move the heating element to the target position.

[0063] The swing range of the connecting rod can be set according to actual needs. For example, the swing range of the connecting rod can be less than or equal to the radius of the wafer, which can ensure that the heating component can move between the center and the edge of the wafer.

[0064] The second type has an adjustment component that is a telescopic rod that can extend and retract along the radius of the wafer, with one end of the telescopic rod connected to the heating component; and a controller that adjusts the extension and retraction length of the telescopic rod to move the heating component to the target position when the temperature difference between the center temperature and the target temperature is greater than a preset value.

[0065] Specifically, one end of the telescopic rod is connected to the heating element, and the controller moves the heating element by changing the length of the telescopic rod. For example, when heating a target location is required, the adjustment length of the telescopic rod can be determined based on the target location and the total length of the telescopic rod. The controller then adjusts the telescopic rod to move the heating element to the target location.

[0066] The total length of the telescopic rod can be set according to actual needs. For example, the total length of the telescopic rod can be less than or equal to the radius of the wafer, which can ensure that the heating component can move between the center and the edge of the wafer.

[0067] In this embodiment of the specification, the heating power of the movable heating device 13 is adjustable; the controller is used to determine the target heating power of the movable heating device based on the temperature difference between the center temperature and the target temperature; the movable heating device 13 is used to heat the target position with the target heating power.

[0068] For example, if the target positions are a first position 5cm away from the center and a second position 8cm away from the center, the temperature difference between the target temperature at the first position and the center temperature and the temperature difference between the target temperature at the second position and the center temperature are determined sequentially. For example, if the target temperature at the first position is 5 degrees lower than the center temperature and the target temperature at the second position is 8 degrees lower than the center temperature, then when the controller controls the movable heating device 13 to move to the first position, it heats the first position with a first heating power. When the controller controls the movable heating device 13 to move to the second position, it heats the second position with a second heating power. The first heating power is less than the second heating power.

[0069] In summary, the solution implemented in this specification can adjust the temperature at various locations on the wafer surface, reducing temperature differences at each location. As the temperature differences are reduced, the corrosion rate differences of the cleaning solution at various locations within the wafer are also improved, greatly reducing the technical problem of different corrosion rates at different locations on the wafer due to temperature differences. This balances the corrosion rates at various locations on the wafer, thereby improving the uniformity of corrosion within the wafer.

[0070] Example 2

[0071] This specification provides a wafer cleaning method, applied in the wafer cleaning apparatus provided in Embodiment 1. The wafer cleaning apparatus includes a rotating stage, cleaning fluid nozzles, a movable heating device, and a controller. Figure 4 The diagram shows a flowchart of a wafer cleaning method provided in an embodiment of this specification. The method includes the following steps:

[0072] Step S41: When cleaning the wafer placed on the rotating stage, start the rotating stage to drive the wafer to rotate;

[0073] Step S42: Spray cleaning fluid onto the center of the wafer through the cleaning fluid nozzle;

[0074] Step S43: The movable heating device is moved relative to the wafer by the controller to heat the surface of the wafer.

[0075] In one optional implementation, controlling the movable heating device to move relative to the wafer via the controller to heat the wafer surface includes:

[0076] The center temperature at the center of the wafer is obtained, and the target temperature at a target location on the wafer is obtained, wherein the target location is different from the center of the wafer;

[0077] When the temperature difference between the center temperature and the target temperature is greater than a preset value, the controller controls the movable heating device to move to the target position to heat the target position.

[0078] In one optional implementation, controlling the movable heating device to move relative to the wafer via the controller to heat the wafer surface includes:

[0079] The controller controls the movable heating device to move back and forth between the center of the wafer and the edge of the wafer to heat the area between the center of the wafer and the edge of the wafer.

[0080] In an optional implementation, the method further includes:

[0081] The target heating power of the portable heating device is determined based on the temperature difference between the center temperature and the target temperature.

[0082] The movable heating device is controlled to heat the target location at the target heating power.

[0083] In one alternative implementation, the target location is a location between the center of the wafer and the edge of the wafer;

[0084] The step of controlling the movable heating device to move relative to the wafer via the controller to heat the wafer surface includes:

[0085] The movable heating device is controlled to move to the target location to heat the annular area where the target location is located.

[0086] Regarding the above methods, the specific implementation of each method has been described in detail in the embodiments of the wafer cleaning apparatus provided in this specification, and will not be elaborated here.

[0087] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0088] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a controller of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing device to produce a machine, such that the instructions, which execute via the controller of the computer or other programmable data processing device, generate instructions for implementing the flowchart. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0089] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0090] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0091] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0092] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A wafer cleaning apparatus, characterized in that, The device includes: A rotating stage, used to place wafers; The cleaning fluid nozzle is positioned above the center of the wafer; A portable heating device is used to heat the surface of the wafer; The controller is connected to the portable heating device; During the cleaning of the wafer, the rotary table drives the wafer to rotate, the cleaning fluid nozzle sprays cleaning fluid towards the center of the wafer, and the controller controls the movable heating device to move relative to the wafer to heat the wafer surface. The device further includes: A temperature sensor is used to detect the center temperature at the center of the wafer and the target temperature at a target location on the wafer, wherein the target location is different from the center of the wafer. The controller is configured to control the movable heating device to move to the target position to heat the target position when the temperature difference between the center temperature and the target temperature is greater than a preset value. The heating power of the portable heating device is adjustable; The controller is used to determine the target heating power of the portable heating device based on the temperature difference between the center temperature and the target temperature. The movable heating device is used to heat the target location with the target heating power.

2. The apparatus according to claim 1, characterized in that, The movable heating device includes a heating component and an adjusting component for moving the heating component. The controller is used to adjust the regulating component to move the heating component to the target position when the temperature difference between the center temperature and the target temperature is greater than a preset value.

3. The apparatus according to claim 2, characterized in that, The adjusting component is a connecting rod that can swing on the surface of the wafer, and one end of the connecting rod is connected to the heating component. The controller is used to adjust the swing angle of the connecting rod to move the heating component to the target position when the temperature difference between the center temperature and the target temperature is greater than a preset value.

4. The apparatus according to claim 2, characterized in that, The adjusting component is a telescopic rod that can extend and retract along the radius of the wafer, and one end of the telescopic rod is connected to the heating component; The controller is used to adjust the extension length of the telescopic rod to move the heating component to the target position when the temperature difference between the center temperature and the target temperature is greater than a preset value.

5. The apparatus according to claim 1, characterized in that, The target location is a position between the center of the wafer and the edge of the wafer; The movable heating device is used to heat the annular region where the target position is located during the process of the rotating table driving the wafer to rotate.

6. A wafer cleaning method, applied to a wafer cleaning apparatus, characterized in that, The wafer cleaning apparatus includes a rotating stage, a cleaning fluid nozzle, a movable heating device, and a controller; the method includes: When cleaning the wafer placed on the rotating stage, the rotating stage is activated to rotate the wafer; The cleaning solution is sprayed onto the center of the wafer through the cleaning solution nozzle; The controller controls the movable heating device to move relative to the wafer in order to heat the surface of the wafer; The step of controlling the movable heating device to move relative to the wafer via the controller to heat the wafer surface includes: The center temperature at the center of the wafer is obtained, and the target temperature at a target location on the wafer is obtained, wherein the target location is different from the center of the wafer; When the temperature difference between the center temperature and the target temperature is greater than a preset value, the controller controls the movable heating device to move to the target position to heat the target position. The target heating power of the portable heating device is determined based on the temperature difference between the center temperature and the target temperature. The movable heating device is controlled to heat the target location at the target heating power.

7. The method according to claim 6, characterized in that, The step of controlling the movable heating device to move relative to the wafer via the controller to heat the wafer surface includes: The controller controls the movable heating device to move back and forth between the center of the wafer and the edge of the wafer to heat the area between the center of the wafer and the edge of the wafer.

Images