Semiconductor cleaning apparatus and cleaning protection method

Abstract

The application provides a semiconductor cleaning device, which comprises a cleaning tank, the cleaning tank having an acid cleaning tank and a circulating tank; the circulating tank having two switchable outlets, one of which is communicated with the acid cleaning tank inlet through a circulating pipeline to make the acid liquid in the circulating tank enter the acid cleaning tank; the other switchable outlet being communicated with a discharge pipeline; a mixer, the outlet of which being communicated with the circulating pipeline, the mixer having two inlets; a first container for containing preheated acid liquid, the first container being communicated with one of the inlets of the mixer through a switchable pipeline; and a supply main pipeline for supplying room temperature acid liquid, the supply main pipeline being communicated with the other inlet of the mixer through a switchable pipeline. The application can rapidly cool the acid liquid in the acid cleaning tank, and can ensure the wafer not to be damaged in time when a fault occurs.

Description

Technical Field

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

[0002] In semiconductor cleaning processes, acidic liquids are typically used to clean the surface films of the semiconductor. To achieve effective cleaning of the semiconductor surface films with acidic liquids, the acidic liquid is usually heated. Taking phosphoric acid for cleaning silicon nitride films as an example, phosphoric acid has high cleaning efficiency at 163 degrees Celsius, but it is difficult to clean the silicon nitride layer at 100 degrees Celsius or below. When using acidic liquids to clean semiconductor surfaces, if the equipment malfunctions and the wafer cannot be removed within the predetermined time, excessive corrosion can easily occur on the semiconductor surface, causing damage to the wafer. Summary of the Invention

[0003] The semiconductor cleaning apparatus and cleaning protection method provided by this invention can quickly cool down acidic liquids and protect wafers.

[0004] In a first aspect, the present invention provides a semiconductor cleaning apparatus, comprising:

[0005] The cleaning tank includes an acid pickling tank and a circulation tank; the circulation tank has two switchable outlets, one of which is connected to the inlet of the acid pickling tank via a circulation pipeline to allow acidic liquid in the circulation tank to enter the acid pickling tank; the other switchable outlet is connected to a discharge pipeline.

[0006] A mixer, the outlet of which is connected to the circulation pipeline, the mixer having two inlets;

[0007] A first container is used to hold a preheated acidic liquid, and the first container is connected to one of the inlets of the mixer via a switchable pipe.

[0008] A main supply line is provided for supplying acidic liquid at room temperature, and the main supply line is connected to another inlet of the mixer via a switchable conduit.

[0009] Optionally, a circulation pump, a heater, and a filter are sequentially arranged on the circulation pipeline, wherein the filter has an on / off inlet and an on / off outlet.

[0010] Optionally, it also includes:

[0011] A filter bypass pipeline, wherein the filter connects the outlet of the heater to the inlet of the pickling tank via a switchable pipeline.

[0012] Optionally, it also includes:

[0013] A nitrogen nozzle is located at the bottom of the pickling tank, and the nitrogen nozzle is used to blow nitrogen into the acidic liquid in the pickling tank.

[0014] Optionally, the number of nitrogen nozzles is multiple, the diameter of the nitrogen nozzles is 0.1 to 2 mm, and the distance between two adjacent nitrogen nozzles is 1 to 20 mm.

[0015] The semiconductor cleaning apparatus provided by this invention, when the cleaning equipment malfunctions and it is difficult to remove the wafer within a predetermined time, closes the outlet of the circulation tank and uses the existing circulation pipeline to supply subsequent acidic liquid. Simultaneously, acidic liquid from the first container and acidic liquid from the main supply line can be mixed and supplied to the pickling tank with a lower temperature acidic liquid. As the low-temperature acidic liquid is supplied, excess acidic liquid overflows into the circulation tank and is discharged through the discharge pipeline in the second area. In this invention, by simultaneously supplying acidic liquid through two supply containers, a larger liquid flow rate can be provided, thereby enabling the higher-temperature acidic liquid to overflow quickly from the pickling tank without waiting for the conduction effect between the low-temperature and high-temperature acidic liquids to cool it down.

[0016] Secondly, the present invention provides a semiconductor cleaning and protection method, comprising:

[0017] Based on predetermined triggering conditions, the outlet connecting the circulation tank and the circulation pipeline is closed;

[0018] The preheated acidic liquid in the first container is mixed with the room-temperature acidic liquid in the main supply line;

[0019] The mixed acidic liquid is supplied to the pickling tank;

[0020] The acidic liquid that overflowed into the circulation tank was discharged through the discharge pipeline.

[0021] Optionally, before supplying the mixed acidic liquid to the pickling tank, the method further includes shutting off the heater in the circulation line.

[0022] Optionally, before supplying the mixed acidic liquid to the pickling tank, the method further includes: closing the switchable inlet and switchable outlet of the filter in the circulation pipeline and opening the filter bypass pipeline.

[0023] Optionally, the method further includes supplying nitrogen gas to the acidic liquid in the pickling tank through a nitrogen nozzle at the bottom of the pickling tank, wherein the flow rate of the supplied nitrogen gas is 5 to 50 L / min.

[0024] Optionally, when supplying the mixed acidic liquid to the pickling tank, the supply flow rate of the acidic liquid is controlled to be 5 to 50 L / min.

[0025] The semiconductor cleaning and protection method provided by this invention allows for the following steps: When the cleaning equipment malfunctions and it becomes difficult to remove the wafer within a predetermined time, the outlet of the circulation tank is closed, and the existing circulation pipeline is used to supply the subsequent acidic liquid. Simultaneously, the acidic liquid in the first container and the acidic liquid in the main supply pipeline can be mixed and supplied to the pickling tank with a lower temperature acidic liquid. As the low-temperature acidic liquid is supplied, excess acidic liquid overflows into the circulation tank and is discharged through the outlet pipeline of the circulation tank. In this invention, by simultaneously supplying acidic liquid through two supply containers, a larger liquid flow rate can be provided, thereby enabling the higher-temperature acidic liquid to overflow quickly from the pickling tank without waiting for the conduction effect between the low-temperature and high-temperature acidic liquids to cool down. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of a semiconductor cleaning apparatus according to an embodiment of the present invention.

[0027] exist Figure 1 In the diagram, 1 represents the pickling tank, 2 represents the first area of ​​the circulation tank, 3 represents the second area of ​​the circulation tank, 4 represents the circulation pump, 5 represents the heater, 6 represents the filter, 7 represents the mixer, 8 represents the first container, 9 represents the pipeline supplying nitrogen to the nitrogen nozzle, and 10 represents the wafer being cleaned. Detailed Implementation

[0028] 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.

[0029] 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.

[0030] 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.

[0031] This embodiment provides a semiconductor cleaning apparatus, such as... Figure 1As shown, it includes: a cleaning tank, which has an acid pickling tank 1 and a circulation tank; wherein, the circulation tank has a first region 2 and a second region 3, the first region 2 has a switchable outlet, which is connected to the inlet of the acid pickling tank 1 through a circulation pipeline, so that the acidic liquid in the first region 2 enters the acid pickling tank 1; the outlet of the second region 3 is connected to a discharge pipeline; when the wafer 10 is cleaned with acidic liquid, the acidic liquid in the acid pickling tank 1 overflows into the circulation tank, and the acidic liquid in the circulation tank is then supplied to the acid pickling tank 1 through the circulation pipeline connected to the first region 2. When the amount of acidic liquid is large, the acidic liquid in the circulation tank is discharged through the outlet of the second region 3. As an optional implementation, a circulation pump 4, a heater 5, and a filter 6 are sequentially arranged in the circulation pipeline. The filter 6 has an inlet and an outlet that can be switched on and off. The circulation pump 4 provides power for the circulating acidic liquid, ensuring its normal flow. The heater 5 heats the circulating acidic liquid, ensuring that the acidic liquid entering the pickling tank 1 has a high temperature, thus enabling the wafer 10 to be cleaned under normal conditions. Since the acidic liquid in the circulation tank is the overflow from the pickling tank 1, which is the acidic liquid that has been used to clean the wafer 10, the filter 6 is installed in the circulation pipeline to filter it in order to remove contaminants or particulate matter from the acidic liquid. Mixer 7, with its outlet connected to a circulation pipeline, has two inlets; a first container 8 is used to hold preheated acidic liquid, and is connected to one of the inlets of mixer 7 via a switchable pipeline; the acidic liquid in the first container 8 is typically used to replenish the acidic liquid in the pickling tank 1 when it is insufficient. Since a relatively high temperature acidic liquid is required to clean wafer 10 under normal circumstances, the acidic liquid in the first container 8 is usually preheated to save cleaning time and improve cleaning efficiency, using phosphoric acid as the cleaning acid. Taking liquid cleaning of silicon nitride film as an example, phosphoric acid in the first container 8 is usually preheated to 100 degrees Celsius. The cleaning efficiency of phosphoric acid on silicon nitride at 163 degrees Celsius is 62 angstroms / minute, while the cleaning efficiency at 100 degrees Celsius is less than 4 angstroms / minute. The phosphoric acid is heated to 100 degrees Celsius, and then heated again to 163 degrees Celsius when it needs to be supplied to the pickling tank 1. As an optional method, the aforementioned heater 5 can be used to heat the phosphoric acid again. Of course, other heating methods can also be used for reheating.The main supply line is used to supply acidic liquid at room temperature. The main supply line is connected to another inlet of the mixer 7 through a switchable pipe. The main supply line supplies acidic liquid at room temperature. When the pickling tank 1 malfunctions, the robotic arm malfunctions, or other malfunctions cause the wafer 10 to be unable to be taken out of the pickling tank 1 in time, the main supply line and the first container 8 simultaneously supply acidic liquid to the mixer 7. The temperature of the acidic liquid in the two containers after mixing will inevitably be lower than 100 degrees Celsius. Since the two containers supply at the same time, a large amount of low-temperature phosphoric acid will enter the pickling tank 1, and the original high-temperature phosphoric acid in the pickling tank 1 will overflow to the second area 3 and be discharged.

[0032] In this embodiment of the semiconductor cleaning apparatus, when the cleaning equipment malfunctions and it is difficult to remove the wafer 10 within a predetermined time, the outlet of the first region 2 is closed, and the existing circulation pipeline is used to supply the subsequent acidic liquid. Simultaneously, the acidic liquid in the first container 8 and the acidic liquid in the main supply pipeline can be mixed and supplied to the pickling tank 1 with a lower temperature acidic liquid. As the low-temperature acidic liquid is supplied, excess acidic liquid overflows into the circulation tank and is discharged through the outlet pipeline of the second region 3. In this embodiment, by simultaneously supplying acidic liquid through two supply containers, a larger liquid flow rate can be provided, thereby enabling the higher-temperature acidic liquid to overflow quickly from the pickling tank 1 without waiting for the conduction effect between the low-temperature and high-temperature acidic liquids to cool it down.

[0033] As an optional implementation, the circulation loop also includes a bypass line for filter 6. Filter 6 connects the outlet of heater 5 to the inlet of pickling tank 1 via a switchable line. During use, filter 6 can obstruct the flow of acidic liquid. When a malfunction occurs during pickling, a large amount of acidic liquid needs to be supplied to pickling tank 1 promptly. At this time, the obstruction of acidic liquid by filter 6 will be particularly prominent. Therefore, a bypass line for filter 6 can be used to bypass filter 6. In the event of a malfunction, acidic liquid can be supplied directly to pickling tank 1 through the bypass line for filter 6, ensuring a timely supply of a large amount of acidic liquid to pickling tank 1.

[0034] As an optional implementation, the cleaning device described above also includes nitrogen nozzles (not shown in the figure), disposed at the bottom of the pickling tank 1. The nitrogen nozzles are used to blow nitrogen gas into the acidic liquid in the pickling tank 1. The nitrogen supply method in the nitrogen nozzles is illustrated by pipe 9 in the figure. The nitrogen nozzles are used to blow nitrogen bubbles into the acidic liquid. The nitrogen bubbles escape rapidly from the acidic liquid, carrying away the heat of the liquid and thus rapidly cooling it. As a preferred implementation, there are multiple nitrogen nozzles, with a diameter of 0.1–2 mm and a spacing of 1–20 mm between adjacent nozzles. The diameter and number of nitrogen nozzles can be selected based on conditions such as the size of the pickling tank 1, the volume of the acidic liquid, the temperature of the acidic liquid, and the required cooling rate of the acidic liquid.

[0035] In this embodiment of the semiconductor cleaning apparatus, when the cleaning equipment malfunctions and it is difficult to remove the wafer 10 within a predetermined time, the outlet of the first region 2 is closed, and the existing circulation pipeline is used to supply the subsequent acidic liquid. Simultaneously, the acidic liquid in the first container 8 and the acidic liquid in the main supply pipeline can be mixed and supplied to the pickling tank 1 with a lower temperature acidic liquid. As the low-temperature acidic liquid is supplied, excess acidic liquid overflows into the circulation tank and is discharged through the outlet pipeline of the second region 3. In this embodiment, by simultaneously supplying acidic liquid through two supply containers, a larger liquid flow rate can be provided, thereby enabling the higher-temperature acidic liquid to overflow quickly from the pickling tank 1 without waiting for the conduction effect between the low-temperature and high-temperature acidic liquids to cool it down.

[0036] This embodiment provides a semiconductor cleaning protection method, including: closing the outlet of a circulation tank according to predetermined triggering conditions; the predetermined triggering conditions include a fault in the pickling tank, a fault in the robotic arm, or other faults that make it difficult to remove the wafer from the pickling tank in a timely manner. When a fault occurs, preheated acidic liquid in a first container is mixed with room temperature acidic liquid in the supply main line; the preheated acidic liquid contained in the first container refers to the highest temperature at which the wafer cleaning rate approaches zero. Taking phosphoric acid in the previous embodiment as an example, the phosphoric acid contained in the first container is phosphoric acid at 100 degrees Celsius; the acidic liquid supplied in the supply main line is room temperature acidic liquid. Again, taking phosphoric acid as an example, the phosphoric acid supplied in the supply main line is at room temperature. Since phosphoric acid at room temperature has a high viscosity, it is difficult to supply it to the pickling tank quickly; in order to ensure the fluidity of the phosphoric acid, and at the same time to ensure that the supplied phosphoric acid is at a low temperature, the preheated acidic liquid in the first container is mixed with the room temperature acidic liquid in the supply main line. After mixing, the mixed acidic liquid is supplied to the pickling tank. The mixed acidic liquid has three characteristics: first, it ensures the fluidity of the acidic liquid; second, its temperature ensures a low cleaning efficiency for the wafers; and third, the two supply sources ensure a large flow rate of the supplied acidic liquid. The acidic liquid overflowing into the circulation tank is discharged through the drain pipe. Because a large amount of acidic liquid is supplied to the pickling tank from two sources, the original acidic liquid in the pickling tank quickly overflows into the circulation tank and is then discharged through the outlet of the second area. By discharging the high-temperature acidic liquid and supplying a low-temperature acidic liquid with a near-zero etching rate for the wafers, the wafers are protected from damage.

[0037] The semiconductor cleaning protection method provided in this embodiment, when the cleaning equipment malfunctions and it is difficult to remove the wafer within a predetermined time, closes the outlet of the circulation tank and uses the existing circulation pipeline to supply subsequent acidic liquid. Simultaneously, the acidic liquid in the first container and the acidic liquid in the main supply pipeline can be mixed and supplied to the pickling tank with a lower temperature acidic liquid. As the low-temperature acidic liquid is supplied, excess acidic liquid overflows into the circulation tank and is discharged through the discharge pipeline in the second area. In this embodiment, by simultaneously supplying acidic liquid through two supply containers, a larger liquid flow rate can be provided, thereby enabling the higher-temperature acidic liquid to overflow quickly from the pickling tank without waiting for the conduction effect between the low-temperature and high-temperature acidic liquids to cool it down.

[0038] As an optional implementation, the method further includes shutting off the heater in the circulation pipeline before supplying the mixed acidic liquid to the pickling tank. Since the existing circulation pipeline contains a heater that provides secondary heating to the acidic liquid, the heater needs to be shut off beforehand during the execution of this embodiment. Using this embodiment, the existing circulation pipeline can be used to supply the pickling tank with low-temperature acidic liquid, requiring only minor modifications to the equipment. This reduces the cost of equipment modification and improves the efficiency of the modification process.

[0039] As an optional implementation, before supplying the mixed acidic liquid to the pickling tank, the method further includes: closing the switchable inlet and outlet of the filter in the circulation pipeline and opening the filter bypass pipeline. Under normal conditions, the acidic liquid in the circulation pipeline is the acidic liquid overflowing from the pickling tank, which needs to be filtered to remove contaminants or particulate matter. However, the filter can obstruct the flow of the acidic liquid, especially when a large amount of acidic liquid is supplied in this embodiment. Considering that the acidic liquid supplied in this embodiment is pure acidic liquid from the first container and the main supply line, free of contaminants and particulate matter, and that it is necessary to reduce obstruction during the supply process, this embodiment uses a filter bypass pipeline without a filter to supply the acidic liquid.

[0040] As an optional implementation, the method further includes: supplying nitrogen gas to the acidic liquid in the pickling tank through a nitrogen nozzle at the bottom of the pickling tank, with a nitrogen flow rate of 5–50 L / min. When nitrogen gas is supplied to the acidic liquid through the nozzle at the bottom of the pickling tank, the nitrogen gas forms bubbles in the acidic liquid. These bubbles escape rapidly upon contact with the high-temperature acidic liquid, carrying away a large amount of heat and thus accelerating the cooling rate of the acidic liquid. The nitrogen flow rate can be determined based on conditions such as the size of the pickling tank, the required cooling rate, and the temperature of the acidic liquid.

[0041] In a preferred embodiment, when supplying the mixed acidic liquid to the pickling tank, the supply flow rate of the acidic liquid is controlled to be 5–50 L / min. The flow rate of the acidic liquid is usually controlled by a circulating pump, and during the supply process, the flow rate can be determined based on conditions such as the size of the pickling tank, the required cooling rate, and the temperature of the acidic liquid.

[0042] The above description does not provide detailed explanations of the technical aspects of each layer's patterning, etching, etc. However, those skilled in the art should understand that various technical means can be used to form layers and regions of the desired shape. Furthermore, to form the same structure, those skilled in the art can also design methods that are not entirely identical to those described above. Additionally, although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination.

[0043] The above are merely specific implementations of this embodiment, but the protection scope of this embodiment is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this embodiment should be included within the protection scope of this embodiment. Therefore, the protection scope of this embodiment should be determined by the protection scope of the claims.

Claims

1. A semiconductor cleaning apparatus, characterized in that, include: A cleaning tank, wherein the cleaning tank comprises an acid pickling tank and a circulation tank; The circulation tank has two switchable outlets. One of the switchable outlets is connected to the pickling tank inlet via a circulation pipeline, so that the acidic liquid in the circulation tank enters the pickling tank. The other switchable outlet is connected to a discharge pipeline. A mixer, the outlet of which is connected to the circulation pipeline, the mixer having two inlets; The first container is used to hold preheated acidic liquid, the temperature of which is lower than the temperature of the original acidic liquid in the pickling tank. The first container is connected to one of the inlets of the mixer through a switchable pipe. A main supply line is provided for supplying acidic liquid at room temperature, and the main supply line is connected to another inlet of the mixer via a switchable conduit.

2. The semiconductor cleaning apparatus as described in claim 1, characterized in that: The circulation pipeline is sequentially equipped with a circulation pump, a heater, and a filter, wherein the filter has an on / off inlet and an on / off outlet.

3. The semiconductor cleaning apparatus as described in claim 2, characterized in that: Also includes: A filter bypass pipeline, wherein the filter connects the outlet of the heater to the inlet of the pickling tank via a switchable pipeline.

4. The semiconductor cleaning apparatus as described in claim 1, characterized in that: Also includes: A nitrogen nozzle is located at the bottom of the pickling tank, and the nitrogen nozzle is used to blow nitrogen into the acidic liquid in the pickling tank.

5. The semiconductor cleaning apparatus as described in claim 4, characterized in that: The number of nitrogen nozzles is multiple, the diameter of the nitrogen nozzles is 0.1~2mm, and the distance between two adjacent nitrogen nozzles is 1~20mm.

6. A semiconductor cleaning and protection method, characterized in that, include: Based on predetermined triggering conditions, the outlet connecting the circulation tank and the circulation pipeline is closed; The preheated acidic liquid in the first container is mixed with the room temperature acidic liquid in the main supply line. The temperature of the preheated acidic liquid is lower than the temperature of the original acidic liquid in the pickling tank. The existing circulation pipeline is used to supply the mixed acidic liquid to the pickling tank; The mixed acidic liquid is supplied to the pickling tank; The acidic liquid overflowing into the circulation tank is discharged through the discharge pipeline, thereby rapidly cooling the acidic liquid in the pickling tank.

7. The semiconductor cleaning and protection method as described in claim 6, characterized in that, The process also includes shutting off the heater in the circulation line before supplying the mixed acidic liquid to the pickling tank.

8. The semiconductor cleaning and protection method as described in claim 6, characterized in that, Before supplying the mixed acidic liquid to the pickling tank, the process also includes: closing the switchable inlet and switchable outlet of the filter in the circulation pipeline and opening the filter bypass pipeline.

9. The semiconductor cleaning and protection method as described in claim 6, characterized in that, The method further includes supplying nitrogen gas to the acidic liquid in the pickling tank through a nitrogen nozzle at the bottom of the pickling tank, wherein the flow rate of the supplied nitrogen gas is 5~50L / min.

10. The semiconductor cleaning and protection method as described in claim 6, characterized in that, When supplying the mixed acidic liquid to the pickling tank, the supply flow rate of the acidic liquid should be controlled at 5~50L / min.

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