A wafer cleaning and etching method integrating high-temperature phosphoric acid and sulfuric acid

Abstract

The present invention provides a wafer cleaning and etching method that integrates high-temperature phosphoric acid and sulfuric acid, including: step S1, controlling the start of a first conveyor belt to transport unprocessed wafers to a designated location and controlling the pause of the first conveyor belt, and controlling a first robot body to drive a first adsorption component at the end of a first robotic arm to adsorb the unprocessed wafer; step S2, controlling the first robot body to place the unprocessed wafer on a placement table within a cleaning device, and controlling the cleaning device to sequentially spray high-temperature phosphoric acid and high-temperature sulfuric acid for cleaning and etching to obtain a processed wafer; step S3, controlling a second robot body to drive a second adsorption component at the end of a second robotic arm to adsorb the processed wafer; step S4, controlling the second robot body to place the processed wafer on a second conveyor belt. The beneficial effect is that this method integrates high-temperature phosphoric acid and high-temperature sulfuric acid, using high-temperature phosphoric acid for cleaning and high-temperature sulfuric acid for etching, which can effectively enhance the cleaning and etching effects.

Description

Technical Field

[0001] The present invention relates to the technical field of wafer cleaning and etching, and in particular to a wafer cleaning and etching method integrating high-temperature phosphoric acid and sulfuric acid. Background Art

[0002] After chemical mechanical polishing, the wafer needs to be cleaned, dried, and other treatments. The purpose of cleaning is to prevent trace particles and metal particles from contaminating semiconductor devices and to ensure the performance and pass rate of semiconductor devices.

[0003] Currently, the methods for cleaning wafers are roughly divided into roller brush cleaning, single-wafer cleaning, etc. However, there are no corresponding protection measures for the wafer transportation process, new impurities may be introduced during the transfer of the wafer, and the cleaning liquid used is relatively single, which greatly weakens the cleaning and etching effect. Summary of the Invention

[0004] In response to the problems existing in the prior art, the present invention provides a wafer cleaning and etching method integrating high-temperature phosphoric acid and sulfuric acid, which pre-sets a cleaning device, a first conveyor belt, a first robot body, a second conveyor belt, and a second robot body. The first robot body is provided with a first robotic arm, and the second robot body is provided with a second robotic arm. The method specifically includes the following steps:

[0005] Step S1, controlling the first conveyor belt to start and transport an unprocessed wafer near the cleaning device to a designated location, controlling the first conveyor belt to pause, and controlling the first robot body to drive a first suction component at the end of the first robot arm to move to the upper surface of the unprocessed wafer to suction the unprocessed wafer;

[0006] Step S2, controlling the first robot body to drive the first robot arm to place the unprocessed wafer on a placement table in the cleaning device, and controlling the cleaning device to sequentially spray high-temperature phosphoric acid and high-temperature sulfuric acid to clean and etch the unprocessed wafer to obtain a processed wafer;

[0007] Step S3, controlling the second robot body to drive a second adsorption component at the end of the second robot arm to move to the upper surface of the processed wafer, and controlling the second adsorption component to adsorb the processed wafer;

[0008] Step S4: controlling the second robot body to drive the second robot arm to place the processed wafer onto the second conveyor belt, and controlling to start the first conveyor belt.

[0009] Preferably, the first conveyor belt is provided with a first ventilation device, and the step S1 includes:

[0010] Step S11, controlling and starting the first conveyor belt to transport the unprocessed wafer near the cleaning device to the designated position and controlling the first conveyor belt to pause;

[0011] Step S12, controlling the first ventilation device to output high-pressure airflow;

[0012] Step S13: Control the first robot body to drive the first adsorption component at the end of the first robot arm to move to the upper surface of the unprocessed wafer to adsorb the unprocessed wafer.

[0013] Preferably, the first conveyor belt is provided with a position detector, and the step S11 includes:

[0014] Step S111, controlling and starting the first conveyor belt to transport the unprocessed wafer close to the cleaning device;

[0015] Step S112, controlling and starting the position detector to detect a real-time position of the unprocessed wafer;

[0016] Step S113: Determine whether the real-time location matches the specified location:

[0017] If so, controlling the first conveyor belt to pause and going to step S12;

[0018] If not, return to step S111.

[0019] Preferably, the second conveyor belt is provided with a second ventilation device, and the step S4 includes:

[0020] The second ventilation device is controlled to output a high-pressure air flow to clean the lower surface of the processed wafer.

[0021] Preferably, the cleaning device comprises:

[0022] a first spray pipe, for spraying the high-temperature phosphoric acid onto the upper surface of the unprocessed wafer for cleaning;

[0023] A second spray pipe is used to spray the high-temperature sulfuric acid onto the upper surface of the unprocessed wafer for etching.

[0024] Preferably, the step S2 includes:

[0025] Step S21, controlling the first robot body to drive the first robot arm to place the unprocessed wafer on the placement table and controlling the rotation of the placement table;

[0026] In step S22 , the first spray pipe is controlled to spray the high-temperature phosphoric acid onto the upper surface of the untreated wafer for cleaning, and after a preset time, the second spray pipe is controlled to spray the high-temperature sulfuric acid onto the upper surface of the untreated wafer for etching.

[0027] Preferably, the cleaning device further includes a third ventilation device, and the step S22 includes:

[0028] The third ventilation device is controlled to output a high-pressure airflow to clean the lower surface of the unprocessed wafer.

[0029] Preferably, the cleaning device further includes a delivery pipe, and the step S22 includes:

[0030] The delivery pipe is controlled to be opened to deliver the high-temperature phosphoric acid and the high-temperature sulfuric acid to an external recovery device for recovery.

[0031] Preferably, the cleaning device further includes an image detection device, and the step S22 includes:

[0032] Step S221, controlling the first spray pipe to spray the high-temperature phosphoric acid onto the upper surface of the untreated wafer at a preset opening for cleaning, and controlling the second spray pipe to spray the high-temperature sulfuric acid onto the upper surface of the untreated wafer for etching;

[0033] Step S222, controlling the image detection device to collect a real-time image of the upper surface of the unprocessed wafer, dividing the real-time image into a plurality of sub-images, and performing feature extraction on each of the sub-images to obtain a regional feature, wherein the regional feature is a dry feature or a wet feature;

[0034] Step S223: Determine whether there is a dry feature in each of the regional features:

[0035] If so, control the first spray pipe to increase the preset opening and return to step S222;

[0036] If not, go to step S3.

[0037] The above technical solution has the following advantages or beneficial effects:

[0038] (1) This method realizes automation of the transportation process and the cleaning process by setting a first conveyor belt to transport unprocessed wafers and a second conveyor belt to transport processed wafers, introducing the automation technology of the first robot body and the second robot body;

[0039] (2) This method uses a first ventilation device on the first conveyor belt and a second ventilation device on the second conveyor belt to release high-pressure gas throughout the transportation process and the cleaning process to clean the lower surfaces of the unprocessed wafers and the processed wafers;

[0040] (3) This method integrates high-temperature phosphoric acid and high-temperature sulfuric acid, and uses high-temperature phosphoric acid for cleaning and high-temperature sulfuric acid for etching, which can effectively enhance the cleaning and etching effects;

[0041] (4) This method transports the high-temperature phosphoric acid and high-temperature sulfuric acid to an external recovery device through a delivery pipe for recovery so that they can be reused in the next cleaning and etching process;

[0042] (5) This method detects the real-time image of the upper surface of the unprocessed wafer through an image detection device, and determines whether it is necessary to increase the preset opening of the first spray pipe based on the real-time image to achieve full coverage of cleaning and etching on the upper surface of the unprocessed wafer. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 A flowchart of the steps of the method in a preferred embodiment of the present invention is shown below;

[0044] Figure 2 Detailed flow chart of step S1 in a preferred embodiment of the present invention;

[0045] Figure 3 Detailed flow chart of step S11 in a preferred embodiment of the present invention;

[0046] Figure 4 Detailed flow chart of step S2 in a preferred embodiment of the present invention;

[0047] Figure 5 This is a specific flow chart of step S22 in a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0048] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments. The present invention is not limited to this embodiment, and other embodiments may also fall within the scope of the present invention as long as they conform to the gist of the present invention.

[0049] In a preferred embodiment of the present invention, based on the above-mentioned problems existing in the prior art, a wafer cleaning and etching method integrating high-temperature phosphoric acid and sulfuric acid is provided, wherein a cleaning device, a first conveyor belt, a first robot body, a second conveyor belt, and a second robot body are pre-set, a first robot body is provided with a first robot arm, and a second robot body is provided with a second robot arm, and the method specifically comprises the following steps:

[0050] Step S1, controlling the start of a first conveyor belt to transport an unprocessed wafer near a cleaning device to a designated location and controlling the pause of the first conveyor belt, and controlling the first robot body to drive a first suction component at the end of a first robot arm to move to the upper surface of the unprocessed wafer to suction the unprocessed wafer;

[0051] Step S2, controlling the first robot body to drive the first robot arm to place the unprocessed wafer on a placement table in the cleaning device, and controlling the cleaning device to sequentially spray high-temperature phosphoric acid and high-temperature sulfuric acid to clean and etch the unprocessed wafer to obtain a processed wafer;

[0052] Step S3, controlling the second robot body to drive a second adsorption assembly at the end of the second robot arm to move to the upper surface of the processed wafer, and controlling the second adsorption assembly to adsorb the processed wafer;

[0053] Step S4, controlling the second robot body to drive the second robot arm to place the processed wafers onto the second conveyor belt, and controlling the start of the first conveyor belt.

[0054] Specifically, in this embodiment, a complete three-dimensional linear robot transmission mechanism is constructed by the first conveyor belt, the second conveyor belt, the first robot body and the second robot body. The first robotic arm on the first robot body and the second robotic arm on the second robot body can perform two-way transmission controlled by themselves, so that the input of unprocessed wafers and the output of processed wafers can be carried out simultaneously, with the ability of high-speed transportation, thereby improving overall efficiency.

[0055] Preferably, the first robot body and the second robot body are capable of detecting complex linear motions to ensure that each unprocessed wafer and each processed wafer are transmitted in real time without error.

[0056] In a preferred embodiment of the present invention, a first ventilation device is provided on the first conveyor belt, such as Figure 2 As shown, step S1 includes:

[0057] Step S11, controlling and starting the first conveyor belt to transport the unprocessed wafers near the cleaning device to a designated position and controlling the first conveyor belt to pause;

[0058] Step S12, controlling the first ventilation device to output high-pressure airflow;

[0059] Step S13 , controlling the first robot body to drive the first adsorption component at the end of the first robot arm to move to the upper surface of the unprocessed wafer to adsorb the unprocessed wafer.

[0060] In a preferred embodiment of the present invention, a position detector is provided on the first conveyor belt, such as Figure 3 As shown, step S11 includes:

[0061] Step S111, controlling and starting the first conveyor belt to transport unprocessed wafers close to the cleaning device;

[0062] Step S112, controlling and starting a position detector to detect a real-time position of an unprocessed wafer;

[0063] Step S113: Determine whether the real-time location matches the specified location:

[0064] If yes, control the first conveyor belt to pause and go to step S12;

[0065] If not, return to step S111.

[0066] Specifically, in this embodiment, considering that in the operating program of the first robot body, the designated position of the unprocessed wafer is a fixed coordinate, it is necessary to ensure that each unprocessed wafer reaches the designated position before controlling the first robot body to perform adsorption. Therefore, a position detector is added to the first conveyor belt. The position detector detects the real-time position of the unprocessed wafer on the first conveyor belt to determine whether the unprocessed wafer reaches the pre-set designated position. If it reaches it, the operating program of the first robot body is run. If it does not reach it, the first conveyor belt is controlled to continue running until the unprocessed wafer reaches the designated position.

[0067] Preferably, in actual operation, only the real-time position of the unprocessed wafer closest to the cleaning device on the first conveyor belt is detected. After the unprocessed wafer is adsorbed and removed, the real-time position of the next unprocessed wafer is detected, and so on.

[0068] In a preferred embodiment of the present invention, a second ventilation device is provided on the second conveyor belt, and step S4 includes:

[0069] The second ventilation device is controlled to output high-pressure airflow to clean the lower surface of the processed wafer.

[0070] Specifically, in this embodiment, during the transmission of unprocessed wafers and processed wafers, a non-contact transmission method is adopted, and high-pressure airflow is output through the first ventilation device and the second ventilation device. Air resistance is formed under the action of upstream and downstream pressures, so that the unprocessed wafers and the processed wafers can maintain a contactless clamping method on the first adsorption component and the second adsorption component, which can ensure that the unprocessed wafers and the processed wafers will not be adhered to by dust particles during the transmission process, and the dust particles can be effectively blown away with the assistance of air resistance.

[0071] In a preferred embodiment of the present invention, the cleaning device comprises:

[0072] a first spray pipe for spraying high-temperature phosphoric acid onto the upper surface of the untreated wafer for cleaning;

[0073] A second spray pipe is used to spray high-temperature sulfuric acid onto the upper surface of the untreated wafer for etching.

[0074] In a preferred embodiment of the present invention, Figure 4 As shown, step S2 includes:

[0075] Step S21, controlling the first robot body to drive the first robot arm to place the unprocessed wafer on the placement table and controlling the rotation of the placement table;

[0076] In step S22 , the first spray pipe is controlled to spray high-temperature phosphoric acid onto the upper surface of the untreated wafer for cleaning, and after a preset time, the second spray pipe is controlled to spray high-temperature sulfuric acid onto the upper surface of the untreated wafer for etching.

[0077] In a preferred embodiment of the present invention, the cleaning device further includes a third ventilation device, and step S22 includes:

[0078] The third ventilation device is controlled to output a high-pressure air flow to clean the lower surface of the unprocessed wafer.

[0079] In a preferred embodiment of the present invention, the cleaning device further includes a delivery pipe, and step S22 includes:

[0080] The transmission pipe is controlled to be opened to transmit the high-temperature phosphoric acid and high-temperature sulfuric acid to an external recovery device for recovery.

[0081] In a preferred embodiment of the present invention, the cleaning device further includes an image detection device, and step S22 includes:

[0082] Step S221, controlling the first spray pipe to spray high-temperature phosphoric acid at a preset opening onto the upper surface of the untreated wafer for cleaning, and controlling the second spray pipe to spray high-temperature sulfuric acid onto the upper surface of the untreated wafer for etching;

[0083] Step S222, controlling the image detection device to collect a real-time image of the upper surface of the unprocessed wafer, dividing the real-time image into a plurality of sub-images, and performing feature extraction on each sub-image to obtain a regional feature, where the regional feature is a dry feature or a wet feature;

[0084] Step S223: Determine whether there is a dry feature in each region feature:

[0085] If yes, control the first spray pipe to increase the preset opening and return to step S222;

[0086] If not, go to step S3.

[0087] Specifically, in this embodiment, considering the rotation relationship of the placement table, the position of the unprocessed wafer on the placement table may be slightly offset, resulting in the upper surface of the unprocessed wafer not being fully cleaned, and the position of the unprocessed wafer cannot be adjusted in real time during the cleaning process. Therefore, an image detection device is added to detect the real-time image of the upper surface of the unprocessed wafer, and multiple regional features are obtained through feature extraction. If there is a dry feature in each regional feature, it means that there is an area on the upper surface of the unprocessed wafer that has not been cleaned. At this time, the first spray pipe is controlled to increase the preset opening to increase the coverage area of ​​the high-temperature phosphoric acid, so as to achieve full coverage cleaning of the upper surface of the unprocessed wafer.

[0088] Preferably, considering that the side area of ​​the unprocessed wafer is smaller than the upper surface area, and the offset of the unprocessed wafer position has little impact on the second spray pipe, real-time image acquisition is only performed on the upper surface of the unprocessed wafer.

[0089] The above description is only a preferred embodiment of the present invention and does not limit the implementation mode and protection scope of the present invention. For those skilled in the art, it should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the content of this specification and illustrations should be included in the protection scope of the present invention.

Claims

1. A wafer cleaning and etching method integrating high-temperature phosphoric acid and sulfuric acid, characterized in that: A cleaning device, a first conveyor belt, a first robot body, a second conveyor belt, and a second robot body are pre-set, a first robot body is provided with a first robotic arm, and a second robot body is provided with a second robotic arm, specifically comprising the following steps: Step S1, controlling the first conveyor belt to start and transport an unprocessed wafer near the cleaning device to a designated location, controlling the first conveyor belt to pause, and controlling the first robot body to drive a first suction component at the end of the first robot arm to move to the upper surface of the unprocessed wafer to suction the unprocessed wafer; Step S2, controlling the first robot body to drive the first robot arm to place the unprocessed wafer on a placement table in the cleaning device, and controlling the cleaning device to sequentially spray high-temperature phosphoric acid and high-temperature sulfuric acid to clean and etch the unprocessed wafer to obtain a processed wafer; Step S3, controlling the second robot body to drive a second adsorption component at the end of the second robot arm to move to the upper surface of the processed wafer, and controlling the second adsorption component to adsorb the processed wafer; Step S4, controlling the second robot body to drive the second robot arm to place the processed wafer on the second conveyor belt, and controlling the start of the first conveyor belt; The first conveyor belt is provided with a first ventilation device, and the step S1 includes: Step S11, controlling and starting the first conveyor belt to transport the unprocessed wafer near the cleaning device to the designated position and controlling the first conveyor belt to pause; Step S12, controlling the first ventilation device to output high-pressure airflow; Step S13, controlling the first robot body to drive the first adsorption component at the end of the first robot arm to move to the upper surface of the unprocessed wafer to adsorb the unprocessed wafer; If a position detector is provided on the first conveyor belt, step S11 includes: Step S111, controlling and starting the first conveyor belt to transport the unprocessed wafer close to the cleaning device; Step S112, controlling and starting the position detector to detect a real-time position of the unprocessed wafer; Step S113: Determine whether the real-time location matches the specified location: If so, controlling the first conveyor belt to pause and going to step S12; If not, return to step S111; In step S112, the position detector only detects the real-time position of the unprocessed wafer closest to the cleaning device on the first conveyor belt, and detects the real-time position of the next unprocessed wafer after the unprocessed wafer is adsorbed and removed.

2. The wafer cleaning and etching method according to claim 1, wherein: The second conveyor belt is provided with a second ventilation device, and the step S4 includes: The second ventilation device is controlled to output a high-pressure air flow to clean the lower surface of the processed wafer.

3. The wafer cleaning and etching method according to claim 1, wherein: The cleaning device comprises: a first spray pipe, for spraying the high-temperature phosphoric acid onto the upper surface of the unprocessed wafer for cleaning; A second spray pipe is used to spray the high-temperature sulfuric acid onto the upper surface of the unprocessed wafer for etching.

4. The wafer cleaning and etching method according to claim 3, wherein: The step S2 comprises: Step S21, controlling the first robot body to drive the first robot arm to place the unprocessed wafer on the placement table and controlling the rotation of the placement table; In step S22 , the first spray pipe is controlled to spray the high-temperature phosphoric acid onto the upper surface of the untreated wafer for cleaning, and after a preset time, the second spray pipe is controlled to spray the high-temperature sulfuric acid onto the upper surface of the untreated wafer for etching.

5. The wafer cleaning and etching method according to claim 4, wherein: The cleaning device further includes a third ventilation device, and step S22 includes: The third ventilation device is controlled to output a high-pressure airflow to clean the lower surface of the unprocessed wafer.

6. The wafer cleaning and etching method according to claim 4, wherein: The cleaning device further includes a delivery pipe, and step S22 includes: The delivery pipe is controlled to be opened to deliver the high-temperature phosphoric acid and the high-temperature sulfuric acid to an external recovery device for recovery.

7. The wafer cleaning and etching method according to claim 4, wherein: The cleaning device further includes an image detection device, and step S22 includes: Step S221, controlling the first spray pipe to spray the high-temperature phosphoric acid onto the upper surface of the untreated wafer at a preset opening for cleaning, and controlling the second spray pipe to spray the high-temperature sulfuric acid onto the upper surface of the untreated wafer for etching; Step S222, controlling the image detection device to collect a real-time image of the upper surface of the unprocessed wafer, dividing the real-time image into a plurality of sub-images, and performing feature extraction on each of the sub-images to obtain a regional feature, wherein the regional feature is a dry feature or a wet feature; Step S223: Determine whether there is a dry feature in each of the regional features: If so, control the first spray pipe to increase the preset opening and return to step S222; If not, go to step S3.

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